Publications by authors named "Charles Marks"

32 Publications

The impact of recent homelessness on the provision of injection drug use initiation assistance among persons who inject drugs in Tijuana, Mexico and Vancouver, Canada.

Drug Alcohol Depend 2021 Aug 24;225:108829. Epub 2021 Jun 24.

Centre on Drug Policy Evaluation, St. Michael's Hospital, Unity Health Toronto, Toronto, Canada; Division of Infectious Diseases & Global Public Health, University of California, San Diego, United States; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada. Electronic address:

Objective: To assess the relationship between experiencing homelessness and assisting injection drug use (IDU) initiation among people who inject drugs (PWID) in Tijuana, Mexico and Vancouver, Canada.

Methods: We used self-reported questionnaire data collected semi-annually on PWID from Tijuana (n = 703) and Vancouver (n = 1551) between 2014 and 2017. Within each setting, the effect of recent (i.e., past six months) homelessness on recent provision of injection initiation assistance (i.e., helping anybody inject for the first time in the past six months) was estimated using inverse-probability-of-treatment (IPT)-weighted estimation of a marginal structural model.

Results: Across follow-up, the prevalence of recent homelessness at a given visit ranged from 11.6%-16.5% among Tijuana-based participants and 9.4%-18.9% among Vancouver-based participants; the prevalence of recent provision of injection initiation at a given follow-up visit was lower, ranging from 3.3%-5.4% in Tijuana and 2.5%-4.1% in Vancouver. Based on the IPT-weighted estimates, recent homelessness was associated with 66% greater odds among Tijuana-based PWID (Adjusted Odds Ratio [AOR] = 1.66; 95% CI: 1.01-2.73) and 47% greater odds among Vancouver-based PWID (AOR = 1.47, 95% CI: 1.02-2.13) of providing injection initiation assistance over the same six-month period.

Conclusion: We found that recently experiencing homelessness was associated with an increased likelihood of PWID reporting IDU initiation assistance over time in both Tijuana and Vancouver. Addressing homelessness may decrease the initiation of IDU via multiple pathways.
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http://dx.doi.org/10.1016/j.drugalcdep.2021.108829DOI Listing
August 2021

Identifying counties at risk of high overdose mortality burden during the emerging fentanyl epidemic in the USA: a predictive statistical modelling study.

Lancet Public Health 2021 Jun 9. Epub 2021 Jun 9.

Department of Medicine, University of California, San Diego, CA, USA.

Background: The emergence of fentanyl around 2013 represented a new, deadly stage of the opioid epidemic in the USA. We aimed to develop a statistical regression approach to identify counties at the highest risk of high overdose mortality in the subsequent years by predicting annual county-level overdose death rates across the contiguous USA and to validate our approach against observed overdose mortality data collected between 2013 and 2018.

Methods: We fit mixed-effects negative binomial regression models to predict overdose death rates in the subsequent year for 2013-18 for all contiguous state counties in the USA (ie, excluding Alaska and Hawaii). We used publicly available county-level data related to health-care access, drug markets, socio-demographics, and the geographical spread of opioid overdose as model predictors. The crude number of county-level overdose deaths was extracted from restricted US Centers for Disease Control and Prevention mortality records. To predict county-level overdose rates for the year 201X: (1) a model was trained on county-level predictor data for the years 2010-201(X-2) paired with county-level overdose deaths for the year 2011-201(X-1); (2) county-level predictor data for the year 201(X-1) was fed into the model to predict the 201X county-level crude number of overdose deaths; and (3) the latter were converted to a population-adjusted rate. For comparison, we generated a benchmark set of predictions by applying the observed slope of change in overdose death rates in the previous year to 201(X-1) rates. To assess the predictive performance of the model, we compared predicted values (of both the model and benchmark) to observed values by (1) calculating the mean average error, root mean squared error, and Spearman's correlation coefficient and (2) assessing the proportion of counties in the top decile (10%) of overdose death rates that were correctly predicted as such. Finally, in a post-hoc analysis, we sought to identify variables with greatest predictive utility.

Findings: Between 2013 and 2018, among the 3106 US counties included, our modelling approach outperformed the benchmark strategy across all metrics. The observed average county-level overdose death rate rose from 11·8 per 100 000 people in 2013 to 15·4 in 2017 before falling to 14·6 in 2018. Our negative binomal modelling approach similarly identified an increasing trend, predicting an average 11·8 deaths per 100 000 in 2013, up to 15·1 in 2017, and increasing further to 16·4 in 2018. The benchmark model over-predicted average death rates each year, ranging from 13·0 per 100 000 in 2013 to 18·3 in 2018. Our modelling approach successfully ranked counties by overdose death rate identifying between 42% and 57% of counties in the top decile of overdose mortality (compared with 29% and 43% using the benchmark) each year and identified 194 of the 808 counties with emergent overdose outbreaks (ie, newly entered the top decile) across the study period, versus 31 using the benchmark. In the post-hoc analysis, we identified geospatial proximity of overdose in nearby counties, opioid prescription rate, presence of an urgent care facility, and several economic indicators as the variables with the greatest predictive utility.

Interpretation: Our model shows that a regression approach can effectively predict county-level overdose death rates and serve as a risk assessment tool to identify future high mortality counties throughout an emerging drug use epidemic.

Funding: National Institute on Drug Abuse.
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http://dx.doi.org/10.1016/S2468-2667(21)00080-3DOI Listing
June 2021

Articulating the Trauma-Informed Theory of Individual Health Behavior.

Stress Health 2021 May 19. Epub 2021 May 19.

Joint Doctoral Program in Interdisciplinary Research on Substance Use, San Diego State University and University of California, San Diego, California, USA.

Exposure to trauma increases the risk of engaging in detrimental health behaviours such as tobacco and substance use. In response, the United States Substance Abuse and Mental Health Services Administration developed Trauma-Informed Care (TIC), an organisational framework for improving the provision of behavioural health care to account for the role exposure to trauma plays in patients' lives. We adapt TIC to introduce a novel theory of behaviour change, the Trauma-Informed Theory of Individual Health Behavior (TTB). TTB posits that individual capacity to undertake intentional health-promoting behaviour change is dependent on three factors: (1) the forms and severity of trauma they have been and are exposed to, (2) how this trauma physiologically manifests (i.e., the trauma response) and (3) resilience to undertake behaviour change despite this trauma response. We define each of these factors and their relationships to one another. We anticipate that the introduction of TTB will provide a foundation for developing theory-driven research, interventions, and policies that improve behavioural health outcomes in trauma-affected populations.
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http://dx.doi.org/10.1002/smi.3068DOI Listing
May 2021

Effects of High-Intensity Interval Training Protocols on Liver Enzymes and Wellness in Women.

J Sports Med (Hindawi Publ Corp) 2021 30;2021:5554597. Epub 2021 Apr 30.

Department of Public and Environmental Wellness, Oakland University, 433 Meadowbrook Road, Rochester 48309, MI, USA.

Background: Single-modality, high-intensity interval training (HIIT) using traditional cardiorespiratory exercise selection has been found to provide similar and sometimes superior cardiometabolic effects compared with moderate-intensity continuous training. However, little is known regarding the cardiometabolic and psychosocial effects of HIIT using resistance training modalities. Therefore, this study aims to compare the effects of HIIT using rowing (R-HIIT) and multimodal HIIT (MM-HIIT) using resistance training on liver enzymes, cardiometabolic risk factors, and psychosocial outcomes.

Method: Recreationally active females with a body mass index <30 kg/m ( = 16, 23.0 ± 5.9 years) were randomized into a MM-HIIT or R-HIIT group and completed a 12-week HIIT intervention (ClinicalTrials.gov registration number: https://clinicaltrials.gov/ct2/show/NCT03093441) using principles of social cognitive theory (SCT). Participants completed pre- and postintervention measurements on anthropometrics, resting heart rate, blood pressure, blood measures (lipids, liver enzymes, and glucose), exercise self-efficacy, and perceived wellness. Analysis of covariance was used to examine differences in postintervention measures between groups after controlling for baseline values, waist circumference, and waist-to-height ratio.

Results: R-HIIT group had significantly decreased alanine aminotransferase (mean difference = 13.16, =0.013, effect size (ES) = 0.44, confidence interval (CI) = 3.40 to 22.92) and aspartate aminotransferase (mean difference = 10.79, =0.024, ES = 0.38, CI = 1.67 to 19.90) levels compared with the M-HIIT group, and the whole group had improved wellness scores (14.72 ± 2.6 to 16.89 ± 2.76, =0.002).

Conclusion: R-HIIT may be an effective preventative method for improving liver health in females without obesity. When using principles of SCT, HIIT may enhance overall well-being.
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http://dx.doi.org/10.1155/2021/5554597DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8110421PMC
April 2021

Methodological approaches for the prediction of opioid use-related epidemics in the United States: a narrative review and cross-disciplinary call to action.

Transl Res 2021 08 31;234:88-113. Epub 2021 Mar 31.

Division of Infectious Diseases and Global Public Health, University of California, San Diego. Electronic address:

The opioid crisis in the United States has been defined by waves of drug- and locality-specific Opioid use-Related Epidemics (OREs) of overdose and bloodborne infections, among a range of health harms. The ability to identify localities at risk of such OREs, and better yet, to predict which ones will experience them, holds the potential to mitigate further morbidity and mortality. This narrative review was conducted to identify and describe quantitative approaches aimed at the "risk assessment," "detection" or "prediction" of OREs in the United States. We implemented a PubMed search composed of the: (1) objective (eg, prediction), (2) epidemiologic outcome (eg, outbreak), (3) underlying cause (ie, opioid use), (4) health outcome (eg, overdose, HIV), (5) location (ie, US). In total, 46 studies were included, and the following information extracted: discipline, objective, health outcome, drug/substance type, geographic region/unit of analysis, and data sources. Studies identified relied on clinical, epidemiological, behavioral and drug markets surveillance and applied a range of methods including statistical regression, geospatial analyses, dynamic modeling, phylogenetic analyses and machine learning. Studies for the prediction of overdose mortality at national/state/county and zip code level are rapidly emerging. Geospatial methods are increasingly used to identify hotspots of opioid use and overdose. In the context of infectious disease OREs, routine genetic sequencing of patient samples to identify growing transmission clusters via phylogenetic methods could increase early detection capacity. A coordinated implementation of multiple, complementary approaches would increase our ability to successfully anticipate outbreak risk and respond preemptively. We present a multi-disciplinary framework for the prediction of OREs in the US and reflect on challenges research teams will face in implementing such strategies along with good practices.
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http://dx.doi.org/10.1016/j.trsl.2021.03.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8217194PMC
August 2021

Prevalence and Correlates of Providing and Receiving Assistance With the Transition to Injection Drug Use.

Epidemiol Rev 2020 01;42(1):4-18

Preventing the transition to injection drug use is an important public health goal, as people who inject drugs (PWID) are at high risk for overdose and acquisition of infectious disease. Initiation into drug injection is primarily a social process, often involving PWID assistance. A better understanding of the epidemiology of this phenomenon would inform interventions to prevent injection initiation and to enhance safety when assistance is provided. We conducted a systematic review of the literature to 1) characterize the prevalence of receiving (among injection-naive persons) and providing (among PWID) help or guidance with the first drug injection and 2) identify correlates associated with these behaviors. Correlates were organized as substance use behaviors, health outcomes (e.g., human immunodeficiency virus infection), or factors describing an individual's social, economic, policy, or physical environment, defined by means of Rhodes' risk environments framework. After screening of 1,164 abstracts, 57 studies were included. The prevalence of receiving assistance with injection initiation (help or guidance at the first injection) ranged 74% to 100% (n = 13 estimates). The prevalence of ever providing assistance with injection initiation varied widely (range, 13%-69%; n = 13 estimates). Injecting norms, sex/gender, and other correlates classified within Rhodes' social risk environment were commonly associated with providing and receiving assistance. Nearly all PWID receive guidance about injecting for the first time, whereas fewer PWID report providing assistance. Substantial clinical and statistical heterogeneity between studies precluded meta-analysis, and thus local-level estimates may be necessary to guide the implementation of future psychosocial and sociostructural interventions. Further, estimates of providing assistance may be downwardly biased because of social desirability factors.
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http://dx.doi.org/10.1093/epirev/mxaa008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947591PMC
January 2020

Farewell to Bright-Line: A Guide to Reporting Quantitative Results Without the S-Word.

Front Psychol 2020 13;11:815. Epub 2020 May 13.

Division of Infectious Disease and Global Public Health, SDSU-UCSD Joint Doctoral Program in Interdisciplinary Research on Substance Use, San Diego, CA, United States.

Recent calls to end the practice of categorizing findings based on statistical significance have focused on what not to do. Practitioners who subscribe to the conceptual basis behind these calls may be unaccustomed to presenting results in the nuanced and integrative manner that has been recommended as an alternative. This alternative is often presented as a vague proposal. Here, we provide practical guidance and examples for adopting a research evaluation posture and communication style that operates without bright-line significance testing. Characteristics of the structure of results communications that are based on conventional significance testing are presented. Guidelines for writing results without the use of bright-line significance testing are then provided. Examples of conventional styles for communicating results are presented. These examples are then modified to conform to recent recommendations. These examples demonstrate that basic modifications to written scientific communications can increase the information content of scientific reports without a loss of rigor. The adoption of alternative approaches to results presentations can help researchers comply with multiple recommendations and standards for the communication and reporting of statistics in the psychological sciences.
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http://dx.doi.org/10.3389/fpsyg.2020.00815DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7237744PMC
May 2020

Opioid agonist treatment scale-up and the initiation of injection drug use: A dynamic modeling analysis.

PLoS Med 2019 11 26;16(11):e1002973. Epub 2019 Nov 26.

Division of Infectious Diseases and Global Public Health, University of California San Diego, La Jolla, California, United States of America.

Background: Injection drug use (IDU) is associated with multiple health harms. The vast majority of IDU initiation events (in which injection-naïve persons first adopt IDU) are assisted by a person who injects drugs (PWID), and as such, IDU could be considered as a dynamic behavioral transmission process. Data suggest that opioid agonist treatment (OAT) enrollment is associated with a reduced likelihood of assisting with IDU initiation. We assessed the association between recent OAT enrollment and assisting IDU initiation across several North American settings and used dynamic modeling to project the potential population-level impact of OAT scale-up within the PWID population on IDU initiation.

Methods And Findings: We employed data from a prospective multicohort study of PWID in 3 settings (Vancouver, Canada [n = 1,737]; San Diego, United States [n = 346]; and Tijuana, Mexico [n = 532]) from 2014 to 2017. Site-specific modified Poisson regression models were constructed to assess the association between recent (past 6 month) OAT enrollment and history of ever having assisted an IDU initiation with recently assisting IDU initiation. Findings were then pooled using linear mixed-effects techniques. A dynamic transmission model of IDU among the general population was developed, stratified by known factors associated with assisting IDU initiation and relevant drug use behaviors. The model was parameterized to a generic North American setting (approximately 1% PWID) and used to estimate the impact of increasing OAT coverage among PWID from baseline (approximately 21%) to 40%, 50%, and 60% on annual IDU initiation incidence and corresponding PWID population size across a decade. From Vancouver, San Diego, and Tijuana, respectively, 4.5%, 5.2%, and 4.3% of participants reported recently assisting an IDU initiation, and 49.4%, 19.7%, and 2.1% reported recent enrollment in OAT. Recent OAT enrollment was significantly associated with a 45% lower likelihood of providing recent IDU initiation assistance among PWID (relative risk [RR] 0.55 [95% CI 0.36-0.84], p = 0.006) compared to those not recently on OAT. Our dynamic model predicts a baseline mean of 1,067 (2.5%-97.5% interval [95% I 490-2,082]) annual IDU initiations per 1,000,000 individuals, of which 886 (95% I 406-1,750) are assisted by PWID. Based on our observed statistical associations, our dynamic model predicts that increasing OAT coverage from approximately 21% to 40%, 50%, or 60% among PWID could reduce annual IDU initiations by 11.5% (95% I 2.4-21.7), 17.3% (95% I 5.6-29.4), and 22.8% (95% I 8.1-36.8) and reduce the PWID population size by 5.4% (95% I 0.1-12.0), 8.2% (95% I 2.2-16.9), and 10.9% (95% I 3.2-21.8) relative to baseline, respectively, in a decade. Less impact occurs when the protective effect of OAT is diminished, when a greater proportion of IDU initiations are unassisted by PWID, and when average IDU career length is longer. The study's main limitations are uncertainty in the causal pathway between OAT enrollment and assisting with IDU initiation and the use of a simplified model of IDU initiation.

Conclusions: In addition to its known benefits on preventing HIV, hepatitis C virus (HCV), and overdose among PWID, our modeling suggests that OAT scale-up may also reduce the number of IDU initiations and PWID population size.
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http://dx.doi.org/10.1371/journal.pmed.1002973DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6879119PMC
November 2019

Machine Learning-Based Predictive Modeling of Surgical Intervention in Glaucoma Using Systemic Data From Electronic Health Records.

Am J Ophthalmol 2019 12 16;208:30-40. Epub 2019 Jul 16.

Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center and Shiley Eye Institute, University of California, San Diego, La Jolla, California, USA. Electronic address:

Purpose: To predict the need for surgical intervention in patients with primary open-angle glaucoma (POAG) using systemic data in electronic health records (EHRs).

Design: Development and evaluation of machine learning models.

Methods: Structured EHR data of 385 POAG patients from a single academic institution were incorporated into models using multivariable logistic regression, random forests, and artificial neural networks. Leave-one-out cross-validation was performed. Mean area under the receiver operating characteristic curve (AUC), sensitivity, specificity, accuracy, and Youden index were calculated for each model to evaluate performance. Systemic variables driving predictions were identified and interpreted.

Results: Multivariable logistic regression was most effective at discriminating patients with progressive disease requiring surgery, with an AUC of 0.67. Higher mean systolic blood pressure was associated with significantly increased odds of needing glaucoma surgery (odds ratio [OR] = 1.09, P < .001). Ophthalmic medications (OR = 0.28, P < .001), non-opioid analgesic medications (OR = 0.21, P = .002), anti-hyperlipidemic medications (OR = 0.39, P = .004), macrolide antibiotics (OR = 0.40, P = .03), and calcium blockers (OR = 0.43, P = .03) were associated with decreased odds of needing glaucoma surgery.

Conclusions: Existing systemic data in the EHR has some predictive value in identifying POAG patients at risk of progression to surgical intervention, even in the absence of eye-specific data. Blood pressure-related metrics and certain medication classes emerged as predictors of glaucoma progression. This approach provides an opportunity for future development of automated risk prediction within the EHR based on systemic data to assist with clinical decision-making.
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http://dx.doi.org/10.1016/j.ajo.2019.07.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6888922PMC
December 2019

CAM Practices and Treatment Adherence Among Key Subpopulations of HIV+ Latinos Receiving Care in the San Diego-Tijuana Border Region: A Latent Class Analysis.

Front Public Health 2019 28;7:179. Epub 2019 Jun 28.

School of Social Work, San Diego State University, San Diego, CA, United States.

Latinos living in the United States-Mexico border region bear a disproportionate HIV/AIDS burden compared to individuals living in the interior of both nations and face a constellation of barriers that determine their ability to access and adhere to HIV care. Use of complementary and alternative medicine (CAM) may be associated with suboptimal treatment adherence. Sociodemographic factors, health practices, and social determinants of health unique to the border region may further contribute to health disparities that undermine care engagement and continuity. Improved understanding of HIV-positive Latino subgroups and their risk profiles can lead to more effective, targeted clinical and public health interventions. We undertook this study to identify and characterize distinct classes of HIV-positive Latinos in the San Diego-Tijuana border region, differentiated by HIV and border-related factors, utilizing latent class analysis. We investigated relationships between class membership and CAM utilization and self-reported antiretroviral therapy (ART) adherence. Five distinct classes were identified with unique demographic, HIV risk, and border mobility profiles. CAM was recently used by nearly half of each class, though there were significant differences in the proportion of CAM use by class ranging from 44.4 to 90.9%. As well, all classes were currently receiving ART at similarly high rates and ART adherence outcomes were not significantly different based on class. Findings highlight the significant use of CAM by all HIV-positive Latinos in the border region and imply the need for a research framework which appropriately acknowledges the heterogeneous nature of this population, such as intersectionality. Further research is recommended into understanding how patients integrate CAM into HIV treatment and the risks and benefits of incorporating CAM into HIV treatment.
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http://dx.doi.org/10.3389/fpubh.2019.00179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6610997PMC
June 2019

Normative data for the Balance Tracking System modified Clinical Test of Sensory Integration and Balance protocol.

Med Devices (Auckl) 2019 8;12:183-191. Epub 2019 May 8.

School of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA, USA.

Force plate balance testing technology has traditionally been underutilized in clinical and research settings due to the high cost and lack of portability. A relatively new force plate called the Balance Tracking System (BTrackS) has been developed to overcome these barriers. BTrackS recently implemented the modified Clinical Test of Sensory Integration and Balance (mCTSIB) as a means of evaluating various sources of sensory information for postural sway control. The present study aimed to provide much needed normative data for the BTrackS mCTSIB protocol. Data from 604 healthy adults (308 women; 296 men) between the ages of 18 and 29 years were collected according to the BTrackS mCTSIB protocol. The protocol consisted of four, 20-second static standing trials that manipulated relative contributions of the vision, proprioception and vestibular sensory systems through various eyes open/closed and foam/no foam conditions. Comparisons of men versus women and the impact of body size (ie body mass index) were determined so that relevant percentile rankings could be calculated. Analysis of variance showed an interaction between sex and task condition on the BTrackS mCTSIB (<0.001). This interaction indicated that women outperformed men on all conditions, but especially in the fourth trial where eyes were closed and standing was done on a compliant foam surface. Percentile rankings were calculated based on sex and BTrackS mCTSIB condition. No relationship was found between BTrackS mCTSIB results and body size. Normative data provided in this study are vital for establishing potential sensory feedback-based balance dysfunctions that may exist clinically or in laboratory settings. In addition, this data can aid in the tracking of changes over a rehabilitation period and/or the effectiveness of balance interventions.
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http://dx.doi.org/10.2147/MDER.S206530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519013PMC
May 2019

The Impact of Different High-Intensity Interval Training Protocols on Body Composition and Physical Fitness in Healthy Young Adult Females.

Biores Open Access 2018 28;7(1):177-185. Epub 2018 Dec 28.

School of Health Sciences, Oakland University, Rochester, Michigan.

Although traditional high-intensity interval training (HIIT) has been effective in improving body composition and physical fitness, it is unclear how multimodal HIIT affects these variables. This study compared the differences between these two training programs on body composition and physical fitness in apparently healthy, nonobese young adult females. A total of 16 participants (mean age = 23 ± 5.08 years) completed a 12-week HIIT intervention with two treatment groups: rowing and multimodal. Immediately before and after the intervention, the following measures were assessed: body mass index (BMI), total body mass, waist circumference, waist-to-height ratio, total body fat %, visceral adipose tissue, lean mass, bone mineral outcomes, cardiovascular fitness, and muscular fitness. A general linear model with repeated measures was used to assess changes over time for the group as a whole, as well as between-group differences. For the group as a whole, there were significant decrease in total body fat % ( = 0.04) and significant increases in BMI ( = 0.015), total body mass ( = 0.003), lean mass ( < 0.001), bone mineral content (BMC) ( < 0.001), VOmax ( = 0.01), broad jump ( = 0.001), squat endurance ( = 0.006), press ( < 0.001), back squat ( < 0.001), and deadlift ( < 0.001) one repetition maximum (1RM). The multimodal group ( < 0.001) increased deadlift 1RM significantly more than the rowing group ( = 0.002). HIIT can be an effective means for improving cardiovascular and muscular fitness, increasing lean mass and BMC, and thereby improving cardiometabolic as well as musculoskeletal health in nonobese females. Using a multimodal approach may give the added benefit of superior muscular strength increases.
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http://dx.doi.org/10.1089/biores.2018.0032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323591PMC
December 2018

"Unusual brain stone": heavily calcified primary neoplasm with some features suggestive of angiocentric glioma.

J Neurosurg 2015 Nov 29;123(5):1256-60. Epub 2015 May 29.

Neuropathology, Cork University Hospital, Cork, Ireland.

This 40-year-old man presented with a 5-month history of progressive right-sided headache associated with visual blurring. He also had a history of epilepsy but had been seizure free with medication for the past 10 years. An initial CT scan of his brain performed 16 years previously had revealed a small area of calcification in the right parietal region. In the current presentation, he had a left-sided homonymous hemianopia but no other neurological deficits. A CT scan of his brain showed a much larger calcified, partly cystic lesion in the right parietal region. Because he was symptomatic, the lesion was excised and the cyst was drained. Histological examination of the excised tissue showed an unusual primary tumor that was difficult to classify but had some features of angiocentric glioma. The heavy calcification, mixed-density cell population, and regions with features of angiocentric glioma were most unusual. The patient remained asymptomatic 5 years after surgery, and follow-up scans did not show recurrence.
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http://dx.doi.org/10.3171/2014.11.JNS131158DOI Listing
November 2015

Headache during haemodialysis in a patient with shunt: a cause for concern?

BMJ Case Rep 2015 Mar 27;2015. Epub 2015 Mar 27.

Department of Neurosurgery, Cork University Hospital, Cork, Ireland.

A 20-year-old woman with a functioning ventriculoperitoneal (VP) shunt consistently reported unbearable vertex headaches and nausea during the last hour of her haemodialysis (HD) sessions. After one particularly severe episode, which was associated with vomiting, restlessness and blurred vision, her team suspected that she was developing dialysis disequilibrium syndrome. She improved fully on cessation of HD, requiring simple analgaesia only, and continued dialysis three times per week. Several more distressing episodes of nausea and headaches compelled us to give intravenous mannitol during HD, resulting in temporary improvement. Subsequently, shorter and more frequent dialysis sessions along with intravenous mannitol resulted in satisfactory clinical response.
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http://dx.doi.org/10.1136/bcr-2014-208887DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4386474PMC
March 2015

What lies beneath.

BMJ Case Rep 2013 Jun 10;2013. Epub 2013 Jun 10.

Department of Neurosurgery, Cork University Hospital-HSE South, Cork, Ireland.

Haemangiopericytomas are a group of aggressive soft tissue sarcomas that originate from the pericytes in the walls of capillaries. Local invasion of the surrounding structures is not uncommon. Symptoms depend on the location, size and grade of tumour. Coexistence with a benign tumour in the same location is very rare. We report an interesting case of occipital scalp lipoma with an underlying torcular haemangiopericytoma and skull defect.
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http://dx.doi.org/10.1136/bcr-2013-009606DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3702867PMC
June 2013

Extradural haematoma--to evacuate or not? Revisiting treatment guidelines.

Clin Neurol Neurosurg 2013 Aug 4;115(8):1201-5. Epub 2013 Jun 4.

Department of Neurosurgery, Cork University Hospital, Wilton, Cork, Ireland.

Background: We describe three cases of extradural haematomas (EDHs) and their management, focusing on operative and non-operative treatment. We also review the available literature from the past three decades as well as the guidelines for the management of EDH. An algorithm is formulated based on different factors, including the clinical course of the patients and their CT findings.

Methods: The first patient presented to us after sustaining a fall with a GCS of 15/15 and a large parieto-occipital EDH with a volume of 90 cm3. He was treated non-operatively. Follow-up CT showed good resolution of the haematoma. The second patient presented with a GCS of 7/15, a posterior fossa EDH with a volume of 30 cm3, and obstructive hydrocephalus. Emergency ventriculostomy was performed, which was converted to a VP shunt. The third case was a patient presenting with a large hemispheric EDH, which was 130 cm3 in volume. The GCS at presentation was 14/15 but dropped to 6/15, following which he underwent craniotomy and evacuation of the EDH.

Results: The Glasgow Outcome Scale (GOS) at three months was five for the first two cases and three for the third case with a dense right hemiplegia.

Conclusion: EDH, both supratentorial and in the posterior fossa, can be managed non-operatively. A large volume EDH (>30 cm3) can be managed non-operatively provided the GCS at presentation and follow up remains the same with symptomatic improvement. Prompt treatment of a large volume EDH may still result in a poor outcome.
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http://dx.doi.org/10.1016/j.clineuro.2013.05.012DOI Listing
August 2013

Craniotomy unplugged.

Emerg Med J 2014 Jan 24;31(1):83. Epub 2013 Jan 24.

Emergency Department, University Hospital Limerick, , Dooradoyle, Limerick, Ireland.

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http://dx.doi.org/10.1136/emermed-2012-202117DOI Listing
January 2014

Development of intracranial hypertension after surgical management of intracranial arachnoid cyst: report of three cases and review of the literature.

World Neurosurg 2013 Jul-Aug;80(1-2):222.e1-4. Epub 2012 Nov 7.

Department of Neurosurgery, Cork University Hospital, Wilton, Cork, Republic of Ireland. Electronic address:

Objective: To describe three cases of delayed development of intracranial hypertension (IH) after surgical treatment of intracranial arachnoid cyst, including the pathogenesis of IH and a review of the literature.

Methods: A retrospective and prospective analysis of three male patients (two 18 years old and one 45 years old) was performed. All patients underwent surgical intervention for symptomatic intracranial arachnoid cyst in the form of fenestration of the cyst and a cystoperitoneal shunt.

Results: All three patients presented at a later stage with new-onset headaches after the initial management of arachnoid cyst. Magnetic resonance imaging and magnetic resonance venography ruled out any intracranial vascular pathology. Lumbar puncture and intracranial pressure monitoring showed increased intracranial pressure suggestive of idiopathic IH. To manage IH, intracranial pressure monitoring, cystoperitoneal shunt, ventriculoperitoneal shunt, and lumboperitoneal shunt were performed.

Conclusions: The pathogenesis of delayed development of IH in this clinical setting is not clearly elucidated. When intracranial arachnoid cysts are treated, the possibility of future development of IH should be borne in mind. Delayed presentation with headaches in patients after treatment of intracranial arachnoid cysts should raise the possibility of IH.
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http://dx.doi.org/10.1016/j.wneu.2012.11.002DOI Listing
November 2013

In praise of the literary eponym--Henry V sign.

QJM 2013 Jan 29;106(1):93-4. Epub 2012 Oct 29.

Department of Medicine, Cork University Hospital, University College Cork, National University of Ireland, Ireland.

The use of eponyms in medicine is often discouraged. However, the literary eponym should be an exception as it is not linked with many of the difficulties associated with conventional eponyms and offers descriptive brevity and accuracy. Here, we illustrate the point with Henry V sign, which will be familiar to many who have cared for patients in the terminal stage of illness.
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http://dx.doi.org/10.1093/qjmed/hcs210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3527745PMC
January 2013

Does surgical technique affect the incidence of spondylodiscitis post-lumbar microdiscectomy? A retrospective analysis of 3063 patients.

Spine (Phila Pa 1976) 2013 Feb;38(4):364-7

Department of Neurosurgery, Cork University Hospital, Cork, Republic of Ireland.

Study Design: Retrospective audit in a single center during a period of 7 years operated by 3 groups of surgeons after 3 different surgical techniques.

Objective: Our study aimed to determine whether surgical technique had any influence on the incidence of spondylodiscitis in patients undergoing lumbar microdiscectomy and to compare this with published rate of incidence of spondylodiscitis.

Summary Of Background Data: The incidence of spondylodiscitis post-lumbar microdiscectomy ranges from 0.2% to 15%. There is limited evidence to compare different techniques and the incidence of spondylodiscitis.

Methods: A total of 3063 patients were analyzed from 2005 to 2011 for discitis postoperatively. The first group followed a standard microdiscectomy technique, the second group used antiseptic (Savlon; Novartis Consumer Health UK Limited, Surrey, UK) irrigation at the end of the procedure to irrigate the disc space, and the third group followed standard microdiscectomy along with usage of a separate disc instruments when discectomy was performed. The number of patients operated in the individual groups was 559, 1122, and 1382.

Results: The total number of patients who had postoperative discitis was 3 (0.10%), with a range of 0.07% to 0.18%. There was 1 case of discitis in each group. The incidence of spondylodiscitis in groups A, B, and C were 0.18%, 0.09%, and 0.07%, respectively.

Conclusion: This study concluded that different techniques used for lumbar microdiscectomy revealed that standard microsurgical technique with usage of antiseptic irrigation for the disc space and usage of separate disc instruments had lesser incidence of spondylodiscitis in comparison with standard microdiscectomy. The overall incidence of postoperative discitis remains less in our series. So far, to our knowledge, this report involves the largest number of patients studied to determine the incidence of discitis in patients undergoing lumbar microdiscectomy.

Level Of Evidence: 3.
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http://dx.doi.org/10.1097/BRS.0b013e318278ec06DOI Listing
February 2013

A prospective randomised study to compare the utility and outcomes of subdural and subperiosteal drains for the treatment of chronic subdural haematoma.

Acta Neurochir (Wien) 2012 Nov 30;154(11):2083-8; discussion 2088-9. Epub 2012 Aug 30.

Department of Neurosurgery, Cork University Hospital, Cork, Republic of Ireland.

Background: The usage of a drain following evacuation of a chronic subdural haematoma (CSDH) is known to reduce recurrence. In this study we aim to compare the clinical outcomes and recurrence rate of utilising two different types of drains (subperiosteal and subdural drain) following drainage of a CSDH.

Methods: Prospective randomised single-centre study analysing 50 patients who underwent CSDH treatment. Two types of drains, subperiosteal (SPD) and subdural (SDD), were utilised on consecutive alternate patients following burr-hole craniostomy, with a total of 25 patients in each group. The drains were left in for 48-h duration and then removed. The modified Rankin Scale (mRS) was used for outcome measurement at 3 and 6 months.

Results: Data analysis was performed by unpaired t test with Welch's correction. It was observed that none of the patients in either group had haematoma recurrence during a 6-month follow-up, and a significant difference in outcome was noted at 6 months (p = 0.0118) more than at 3 months (p = 0.0493) according to the statistical analysis. Postoperative seizure and inadvertent placement of the subdural drain into the brain parenchyma were the two complications noted in this study. Anticoagulant use prior to the surgery did not affect the outcome in either group.

Conclusions: We conclude there was no recurrence of CSDH utilising the SDD and SPD following burr-hole craniostomy. The mRS measurement at the 6-month follow-up was found to be statistically significant, with better outcomes with utilisation of the SPD. The SPD may thus prove to be more beneficial than the SDD in the treatment of CSDH. A multi-centre study with a larger group of patients is recommended to reinforce the results from our study.
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http://dx.doi.org/10.1007/s00701-012-1483-1DOI Listing
November 2012

Pseudotumor cerebri following traumatic brain injury in a 29-year-old man.

J Nat Sci Biol Med 2012 Jan;3(1):105-7

Department of Neurological Surgery, Cork University Hospital, Wilton, Republic of Ireland.

We describe a case of pseudotumor cerebri in a young man developing 4 years post-traumatic brain injury (TBI). A 29-year-old man was admitted after sustaining a fall with headache, and no clinical deficits were noted on examination. CT brain demonstrated an extradural hematoma. This was successfully evacuated after his symptomatic worsening. Following this, he developed bone flap infection and had the infected bone flap removed. He developed chronic mild-to-moderate headache following these procedures, which failed to respond to medical treatment. Pseudotumor cerebri was diagnosed. A lumboperitoneal (LP) shunt, ventriculo-peritoneal (VP) shunt, and bitemporal craniectomy were performed as a part of management at different stages. Post-TBI patients may present with chronic headache and in such circumstances, a possibility of pseudotumor cerebri must be considered. Investigations should include neuroimaging in the form of MRI/MRV and fundoscopy to look for papilledema. Management in the form of CSF flow diversion techniques (VP and LP shunt) with medical management results in good clinical outcomes.
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http://dx.doi.org/10.4103/0976-9668.95987DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3361769PMC
January 2012

Stability Ball Sitting Elevates Peak Arm Ergometry Oxygen Consumption and Heart Rate.

Int J Exerc Sci 2012;5(4):360-366. Epub 2012 Oct 15.

Exercise Science Program, School of Health Sciences, Oakland University, Rochester, MI, USA.

This study compared sitting on a stability ball (B) to sitting on a chair (C) during arm ergometry to determine the impact on peak VO, peak heart rate (HR), and exercise intensity prescription. Open-circuit spirometer, blood pressure, and HR were monitored during rest and continuous graded exercise test to exhaustion using an arm ergometer. Twenty-seven apparently healthy adults exercised twice, once at B and the other trial C (order randomized), with 60 minutes of rest between trials. ANOVA for repeated measures (α < 0.05) and paired testing using Holm's-sequential Bonferroni were used to analyze results for 30 W, 45 W, Penultimate, and Peak stages of exercise. VO was significantly higher (8% to 12%, < 0.001) for all stages of exercise for B compared to C. HR was significantly higher ( < 0.001) only at the Penultimate and Peak levels (3% and 2%, respectively) for B compared to C; all other sub-maximal HRs were not significantly different. There were no significant main effects or interactions (P≥ 0.138) when VO and HR were expressed as percentage of maximum. Compared to chair sitting, the stability ball has a greater absolute metabolic response with little impact on HR. Prescribing exercise with absolute MET levels should consider this; however, intensity as a percentage of maximum may not be affected by the stability ball.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4738882PMC
October 2012

Stability Ball Sitting versus Chair Sitting During Sub-maximal Arm Ergometry.

Int J Exerc Sci 2012;5(1):16-25. Epub 2012 Jan 15.

Exercise Science Program, School of Health Sciences, Oakland University, Rochester, MI, USA.

It was predicted that sitting on a stability ball during arm ergometry would elevate cardiovascular parameters when compared to sitting on a chair and that this would be associated with greater recruitment of trunk and leg skeletal muscles.

Methods: Open-circuit spirometry, videotaping, blood pressure, heart rate, and EMG were conducted during rest and four minute stages of 15 W, 30 W, and 45 W using a Monark arm ergometer. Twenty-six apparently healthy adults exercised twice, once sitting on a stability ball and the other sitting on a chair (order randomized), with 45 to 60 minutes of rest between. ANOVA for repeated measures and paired-t testing were used for analysis.

Results: Oxygen consumption was significantly 10 to 16% higher during exercise while sitting on the stability ball. There were no significant differences between sitting modes for heart rate, SBP, and DBP. Also, resting and exercise rectus femoris and 45 W external oblique EMGs were significantly higher on the stability ball. Finally, the knee was significantly more extended with the feet farther apart and more forward on the stability ball.

Conclusion: The stability ball significantly elevates oxygen consumption during sub-maximal arm cranking without significantly increasing heart rate or blood pressure and this is associated with increased thigh muscle activation and lower leg repositioning.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4738981PMC
January 2012

Acid generation upon thermal concentration of natural water: the critical water content and the effects of ionic composition.

J Contam Hydrol 2009 Oct 20;109(1-4):62-81. Epub 2009 Aug 20.

Department of Chemistry, The Catholic University of America, Washington, DC 20064, United States.

Thermal evaporation of a variety of simulated pore waters from the region of Yucca Mountain, Nevada, produced acidic liquids and gases during the final stages of evaporation. Several simulated pore waters were prepared and then thermally distilled in order to collect and analyze fractions of the evolved vapor. In some cases, distillates collected towards the end of the distillation were highly acidic; in other cases the pH of the distillate remained comparatively unchanged during the course of the distillation. The results suggest that the pH values of the later fractions are determined by the initial composition of the water. Acid production stems from the hydrolysis of magnesium ions, especially at near dryness. Near the end of the distillation, magnesium nitrate and magnesium chloride begin to lose water of hydration, greatly accelerating their thermal decomposition to form acid. Acid formation is promoted further when precipitated calcium carbonate is removed. Specifically, calcium chloride-rich pore waters containing moderate (10-20 ppm) levels of magnesium and nitrate and low levels of bicarbonate produced mixtures of nitric and hydrochloric acid, resulting in a precipitous drop in pH to values of 1 or lower after about 95% of the original volume was distilled. Waters with either low or moderate magnesium content coupled with high levels of bicarbonate produced slightly basic fractions (pH 7-9). If calcium was present in excess of bicarbonate, waters containing moderate levels of magnesium produced acid even in the presence of bicarbonate, due to the precipitation of calcium carbonate. Other salts such as halite and anhydrite promote the segregation of acidic vapors from residual basic solids. The concomitant release of wet acid gas has implications for the integrity of the alloys under consideration for containers at the Yucca Mountain nuclear waste repository. Condensed acid gases at very low pH, especially mixtures of nitric and hydrochloric acid, are capable of corroding even alloys, such as nickel-based Alloy 22, which are considered to be corrosion-resistant under milder conditions.
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http://dx.doi.org/10.1016/j.jconhyd.2009.08.003DOI Listing
October 2009

Effect of a blueberry nutritional supplement on macronutrients, food group intake, and plasma vitamin E and vitamin C in US athletes.

Int J Food Sci Nutr 2008 Jun;59(4):327-38

Department of Plant Foods Science and Technology, Instituto del Frío, Consejo Superior de Investigaciones Científicas, Ciudad Universitaria, Madrid, Spain.

Antioxidants from a blueberry beverage may impact plasma vitamins. We examined vitamins/food selection in 12 college athletes during 30 days compared with placebo. Blood was collected before and after exercise at the beginning of the study (day 1) and then after a 30-day period of taking a daily supplemental beverage (day 30). The six trials involved blood that was drawn pre-beverage ingestion/pre-exercise (trials 1 and 4), post-beverage ingestion/pre-exercise (trials 2 and 5), and post-beverage ingestion/1 h post-exercise (trials 3 and 6), on day 1 (trials 1, 2, and 3) and day 30 (trials 4, 5, and 6). Analysis of variance revealed non-significant differences for macronutrient or gamma-tocopherol and vitamin C intakes by food frequency questionnaire or plasma vitamins by liquid chromatography. There was a trend (P = 0.083) in the group x time interaction for alpha-tocopherol intake by repeated-measures analysis of variance. Blueberry alpha-tocopherol (23.91 +/- 9.31 mg) was significantly (P < 0.05) higher than placebo alpha-tocopherol intake (7.59 +/- 0.95 mg) on day 1, but not on day 30 (blueberry, alpha-tocopherol = 9.04 +/- 2.35 mg, placebo, alpha-tocopherol = 11.46 +/- 3.65 mg) by pairwise comparisons. Blueberry supplementation did not affect plasma vitamin concentrations or gamma-tocopherol and vitamin C intakes, and may reduce alpha-tocopherol intake in those starting with a higher alpha-tocopherol intake, yet not altering athletes' eating habits.
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http://dx.doi.org/10.1080/09637480701550176DOI Listing
June 2008

Epithelioid hemangioendothelioma of the spine. Report of two cases.

J Neurosurg Spine 2005 Nov;3(5):393-9

Department of Neurosurgery, Cork University Hospital, Wilton, Cork, Republic of Ireland.

Epithelioid hemangioendothelioma (EH) is a rare tumor of vascular origin. The authors describe two cases of spinal EH, one involving the T-10 vertebra and the second involving the upper cervical spine. In the first case the patient underwent resection of the tumor; this case represents the longest reported follow-up period for spinal EH. In the second case, extensive involvement of C-2, C-3, and C-4 as well as encasement of both vertebral arteries precluded safe tumor resection, and posterior occipitocervical stabilization was performed. The patient subsequently died of metastatic disease. The findings in these two cases underscore the difficulty in predicting the clinical behavior of spinal EH based solely on histological and clinical features as well as the uncertainty of the roles of surgery, chemotherapy, and radiotherapy in the oncological management of a spinal tumor for which clinical data are very limited.
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http://dx.doi.org/10.3171/spi.2005.3.5.0393DOI Listing
November 2005

Radiology quiz case 4: sphenoidal sinus mucocele.

Arch Otolaryngol Head Neck Surg 2005 Sep;131(9):824, 827-8

Royal College of Surgeons in Ireland.

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http://dx.doi.org/10.1001/archotol.131.9.824DOI Listing
September 2005

Schistosomiasis of the spinal cord presenting as progressive myelopathy. Case report.

J Neurosurg Spine 2005 Jul;3(1):61-3

Department of Neurosurgery, Cork University Hospital, Cork, Ireland.

The authors report on a case of schistosomiasis of the spinal cord in an individual returning to Ireland after a 25-year residence in Africa, where the infection affects approximately 200 million people.
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http://dx.doi.org/10.3171/spi.2005.3.1.0061DOI Listing
July 2005

Characterization of melanophore morphology by fractal dimension analysis.

Pigment Cell Res 2004 Apr;17(2):165-72

Biology Department, College of Engineering and Science, University of Detroit Mercy, Detroit, MI, USA.

Fractal or focal dimension (FD) analysis is a valuable tool to identify physiologic stimuli at the cellular and tissue levels that allows for quantification of cell perimeter complexity. The FD analysis was determined on fluorescence images of caffeine- or epinephrine-treated (or untreated control) killifish Fundulus heteroclitus (Linneaus) melanophores in culture. Cell perimeters were indicated by rhodamine-phalloidin labeling of cortical microfilaments using box-counting FD analysis. Caffeine-treated melanophores displayed dispersed melanosomes in cells with less serrated edges and reduced FD and complexity. Complexity in epinephrine-treated cells was significantly higher than the caffeine-treated cells or in the control. Cytoarchitectural variability of the cell perimeter is expected because cells change shape when cued with agents. Epinephrine-treated melanophores demonstrated aggregated melanosomes in cells with more serrated edges, significantly higher FD and thus complexity. Melanophores not treated with caffeine or epinephrine produced variable distributions of melanosomes and resulted in cells with variably serrated edges and intermediate FD with a larger SE of the regression and greater range of complexity. Dispersion of melanosomes occurs with rearrangements of the cytoskeleton to accommodate centrifugal distribution of melanosomes throughout the cell and to the periphery. The loading of melanosomes onto cortical microfilaments may provide a less complex cell contour, with the even distribution of the cytoskeleton and melanosomes. Aggregation of melanosomes occurs with rearrangements of the cytoskeleton to accommodate centripetal distribution of melanosomes. The aggregation of melanosomes may contribute to centripetal retraction of the cytoskeleton and plasma membrane. The FD analysis is, therefore, a convenient method to measure contrasting morphologic changes within stimulated cells.
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http://dx.doi.org/10.1046/j.1600-0749.2003.00125.xDOI Listing
April 2004
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