Publications by authors named "Vinayak Joshi"

23 Publications

  • Page 1 of 1

Variation in the Occurrence of Genotypes of in Periodontal Health and Disease.

Int J Environ Res Public Health 2020 03 11;17(6). Epub 2020 Mar 11.

Central Research Laboratory, Maratha Mandal's NGH Institute of Dental Sciences & Research Centre, Bauxite Road, Belagavi, Karnataka 590010, India.

is regarded as a "keystone pathogen" in periodontitis. The fimbria assists in the initial attachment, biofilm organization, and bacterial adhesion leading to the invasion and colonization of host epithelial cells. The present study aimed to investigate the occurrence of genotypes in patients with chronic periodontitis and healthy individuals in the Indian population, and to study their association with the number of cells obtained in subgingival plaque samples of these subjects. The study comprised 95 samples from the chronic periodontitis (CP) group and 35 samples from the healthy (H) group, which were detected positive for in our previous study. Fimbrial genotyping was done by PCR and PCR-restriction fragment length polymorphism (RFLP). The type II was more prevalent in the CP group (55.89%), followed by type IV (30.52%), whereas in the H group, type I was the most prevalent fimbria (51.42%). The quantity of cells increased with the presence of types II and III. Our results suggest a strong relationship between types II and IV and periodontitis, and between type I and the healthy condition. The colonization of organisms was increased with the occurrence of type II in deep periodontal sites, which could play an important role in the progression of the disease.
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http://dx.doi.org/10.3390/ijerph17061826DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7142462PMC
March 2020

Automated Detection of Malarial Retinopathy in Retinal Fundus Images obtained in Clinical Settings.

Annu Int Conf IEEE Eng Med Biol Soc 2018 Jul;2018:5950-5953

Cerebral malaria (CM) is a life-threatening clinical syndrome associated with 5-10% of malarial infection cases, most prevalent in Africa. About 23% of cerebral malaria cases are misdiagnosed as false positives, leading to inappropriate treatment and loss of lives. Malarial retinopathy (MR) is a retinal manifestation of CM that presents with a highly specific set of lesions. The detection of MR can reduce the false positive diagnosis of CM and alert physicians to investigate for other possible causes of the clinical symptoms and apply a more appropriate clinical intervention of underlying diseases. In order to facilitate easily accessible and affordable means of MR detection, we have developed an automated software system that detects the retinal lesions specific to MR, whitening and hemorrhages, using retinal color fundus images. The individual lesion detection algorithms were combined into an MR detection model using partial least square classifier. The classifier model was trained and tested on retinal image dataset obtained from 64 patients presenting with clinical signs of CM (44 with MR, 20 without MR). The MR detection model yielded specificity of 92% and sensitivity of 68%, with an AUC of 0.82. The proposed MR detection system demonstrates potential for broad screening of MR and can be integrated with a low-cost and portable retinal camera, to provide a bed-side tool for confirming CM diagnosis.
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http://dx.doi.org/10.1109/EMBC.2018.8513603DOI Listing
July 2018

Detection of antibodies against Aggregatibacter actinomycetemcomitans in serum and saliva through ELISA in periodontally healthy individuals and individuals with chronic periodontitis.

Microb Pathog 2018 Dec 9;125:438-442. Epub 2018 Oct 9.

Department of Molecular Biology & Immunology, Maratha Mandal's NGH Institute of Dental Sciences and Research Centre, Belgaum, 590010, Karnataka, India.

Background: Periodontitis is a persistent polymicrobial infection, which leads to chronic inflammation in the tooth supporting tissues. Aggregatibacter actinomycetemcomitans are normal commensals of oral cavity but are low in number in periodontally healthy subjects. They are one of the major pathogens aetiologically linked to periodontal disease. Plasma and salivary antibody measurement may be useful to support diagnosis, disease activity, classification and prognosis of periodontitis. The aim of the present study was to investigate the association between the serum and salivary antibody levels to A. actinomycetemcomitans and therefore, to find whether this association was varying in different grades of periodontitis.

Method: Total of 50 periodontally healthy and 50 chronic periodontitis subjects (35-65 years) of both sexes were included for the study. 2 ml of un-stimulated saliva and 5 ml of venous blood was collected under sterile conditions. The detection of antibodies against A. actinomycetemcomitans in periodontally healthy individuals and individuals with chronic periodontitis was performed using indirect ELISA.

Results: Results showed serum IgG, IgA mean levels against A. actinomycetemcomitans were higher in chronic periodontitis subjects compared to mean levels in periodontally healthy subjects. Similarly, salivary IgG, IgA levels were also raised in chronic periodontitis patients as compared in healthy subjects. Also the mean levels of serum IgG and salivary IgA were increased as the severity of disease increased.

Conclusion: Antibody titer using saliva and serum could be useful tool for screening of patients with chronic periodontitis. Further, monitoring the various phases of treatment outcome using saliva could be a useful, non-invasive, prognostic indicator.
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http://dx.doi.org/10.1016/j.micpath.2018.10.007DOI Listing
December 2018

Comparative evaluation of the efficacy of a herbal mouthwash and chlorhexidine mouthwash on select periodontal pathogens: An and study.

J Indian Soc Periodontol 2017 Jul-Aug;21(4):270-275

Maratha Mandal's NGH Institute of Dental Sciences and Research Centre, Central Research Laboratory, Belgaum, Karnataka, India.

Background: Several herbal mouthwash and herbal extracts have been tested and in search of a suitable adjunct to mechanical therapy for long-term use. In this study, we aimed to look at the antimicrobial effect of the herbal mouthwash and chlorhexidine (CHX) mouthwash on select organisms in test and an model.

Materials And Methods: The antimicrobial effects were determined against standard strains of bacteria that are involved in different stages of periodontal diseases. The tests included determination of minimum inhibitory concentration (MIC) using broth dilution and agar diffusion. In the part of the study supragingival dental plaque were obtained from 20 periodontally healthy adult volunteers. Descriptive analysis was done for the entire quantitative and qualitative variable recorded.

Results: The MIC by broth dilution method found no statistically significant difference between the mouthwashes. The agar dilution method showed CHX was more effective as compared to the herbal mouthwash against standard strains of , , and . However, no difference was observed between the mouthwashes for , , and . The results conclude that none of the selected mouthwashes were statistically significantly different from each other.

Conclusion: In the present study, CHX showed higher levels of antimicrobial action than the herbal mouthwash against bacterial species. The results reinforce the earlier findings that the testing is sensitive to methods and due diligence is needed when extrapolating the data for further use. However, long-term use and effectiveness against the periopathogens need to be tested in well-planned clinical trials.
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http://dx.doi.org/10.4103/jisp.jisp_382_16DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5813340PMC
February 2018

Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans: Relationship of serotypes to herpesvirus and periodontal status in Indian subjects.

Microb Pathog 2017 Sep 28;110:189-195. Epub 2017 Jun 28.

Department of Public Health Dentistry, Maratha Mandal's Nathajirao G. Halgekar Institute of Dental Sciences & Research Centre, Belagavi, Karnataka, India.

Background: The virulence of Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) in any individual depends on the type of strain of this bacterium. To our knowledge, there have been no studies reported in Indian subjects about A. actinomycetemcomitans serotype occurrence, co-existence with herpes virus and the possible influence of such co-existence on periodontal pathology.

Methods: Subjects for this study were a subset of a larger study to identify the prevalence of A. actinomycetemcomitans in chronic periodontitis. A total of 63 subjects (12 periodontally healthy and 51 with chronic periodontitis) who were positive for A. actinomycetemcomitans were serotyped for strain-level identification. The presence of Human Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) was tested in subgingival plaque samples by polymerase chain reaction.

Results: All five serotypes a to e were detected. Of the samples analyzed 38.09% harbored a single serotype, 36.5% had two serotypes, 6.3% demonstrated three and 4.7% demonstrated four serotypes. None of the samples showed presence of JP2 strain. Serotypes b, c, and e were most frequently identified in these individuals (46.03%, 36.5% and 38.09% respectively). Presence of serotypes b and c and absence of serotype d was associated with increased PD and CAL. Among 63 samples analyzed, 11 samples had CMV, four samples had EBV and nine samples had both these viruses. The PD and CAL were significantly higher (p = 0.04) when a combination of CMV and one of the serotypes was present indicating a pathological role of the coexistence.

Conclusion: Multiple serotypes are associated with chronic periodontitis in Indians, however, JP2 strains are not detectable in this cohort. Presence of multiple serotypes and a combination of any serotype with herpesvirus is associated with greater severity of the disease.
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http://dx.doi.org/10.1016/j.micpath.2017.06.041DOI Listing
September 2017

A tale of two risks: smoking, diabetes and the subgingival microbiome.

ISME J 2017 09 23;11(9):2075-2089. Epub 2017 May 23.

Division of Periodontology, College of Dentistry, The Ohio State University, Coloumbus, OH, USA.

Although smoking and diabetes have been established as the only two risk factors for periodontitis, their individual and synergistic impacts on the periodontal microbiome are not well studied. The present investigation analyzed 2.7 million 16S sequences from 175 non-smoking normoglycemic individuals (controls), smokers, diabetics and diabetic smokers with periodontitis as well as periodontally healthy controls, smokers and diabetics to assess subgingival bacterial biodiversity and co-occurrence patterns. The microbial signatures of periodontally healthy smokers, but not diabetics, were highly aligned with the disease-associated microbiomes of their respective cohorts. Diabetics were dominated by species belonging to Fusobacterium, Parvimonas, Peptostreptococcus, Gemella, Streptococcus, Leptotrichia, Filifactor, Veillonella, TM7 and Terrahemophilus. These microbiomes exhibited significant clustering based on HbA1c levels (pre-diabetic (<6.5%), diabetic (6.5-9.9%), diabetics >10%). Smokers with periodontitis evidenced a robust core microbiome (species identified in at least 80% of individuals) dominated by anaerobes, with inter-individual differences attributable largely to the 'rare biosphere'. Diabetics and diabetic smokers, on the other hand, were microbially heterogeneous and enriched for facultative species. In smokers, microbial co-occurrence networks were sparse and predominantly congeneric, while robust inter-generic networks were observed in diabetics and diabetic smokers. Smoking and hyperglycemia impact the subgingival microbiome in distinct ways, and when these perturbations intersect, their synergistic effect is greater than what would be expected from the sum of each effect separately. Thus, this study underscores the importance of early intervention strategies in maintaining health-compatible microbiomes in high-risk individuals, as well as the need to personalize these interventions based on the environmental perturbation.
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http://dx.doi.org/10.1038/ismej.2017.73DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5563960PMC
September 2017

Automated Detection of Malarial Retinopathy in Digital Fundus Images for Improved Diagnosis in Malawian Children with Clinically Defined Cerebral Malaria.

Sci Rep 2017 02 15;7:42703. Epub 2017 Feb 15.

Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.

Cerebral malaria (CM), a complication of malaria infection, is the cause of the majority of malaria-associated deaths in African children. The standard clinical case definition for CM misclassifies ~25% of patients, but when malarial retinopathy (MR) is added to the clinical case definition, the specificity improves from 61% to 95%. Ocular fundoscopy requires expensive equipment and technical expertise not often available in malaria endemic settings, so we developed an automated software system to analyze retinal color images for MR lesions: retinal whitening, vessel discoloration, and white-centered hemorrhages. The individual lesion detection algorithms were combined using a partial least square classifier to determine the presence or absence of MR. We used a retrospective retinal image dataset of 86 pediatric patients with clinically defined CM (70 with MR and 16 without) to evaluate the algorithm performance. Our goal was to reduce the false positive rate of CM diagnosis, and so the algorithms were tuned at high specificity. This yielded sensitivity/specificity of 95%/100% for the detection of MR overall, and 65%/94% for retinal whitening, 62%/100% for vessel discoloration, and 73%/96% for hemorrhages. This automated system for detecting MR using retinal color images has the potential to improve the accuracy of CM diagnosis.
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http://dx.doi.org/10.1038/srep42703DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5309896PMC
February 2017

Indirect immunofluorescence technique to study expression of toll-like receptor 4 in chronic periodontitis.

Indian J Dent Res 2016 May-Jun;27(3):283-7

Department of Periodontics, Maratha Mandal's N.G.H. Institute of Dental Sciences and Research Centre, Belgaum, Karnataka, India.

Aim: The aim of this study was to analyze the expression level and localization of Toll-like receptor (TLR) 4 in gingival samples of healthy and chronic periodontitis subjects by indirect immunofluorescence technique (IFT).

Materials And Methods: In this study, gingival tissue samples were obtained from 25 healthy and 25 periodontitis individuals. The tissues were processed and the initial characterization was done by hematoxylin and eosin staining. The expression and localization of the TLR4 receptor were determined in the epithelial and connective layer cells of the gingival tissue using the indirect IFT. Immunofluorescence images were acquired and quantitative expression of TLRs was analyzed by calculating the percentage of cells showing positive results.

Results: We found that the healthy control group exhibited significantly lower values of TLR4 expression in comparison with the periodontitis patients. We also found that in patients with periodontitis the concentration of TLR4 was higher in the epithelium as compared to their expression in connective tissue cells.

Conclusions: These data suggested a definite involvement of TLR4 in initiating and progression of an inflammatory response in periodontitis.
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http://dx.doi.org/10.4103/0970-9290.186230DOI Listing
October 2017

Occurrence of Aggregatibacter actinomycetemcomitans in Indian chronic periodontitis patients and periodontally healthy adults.

J Indian Soc Periodontol 2016 Mar-Apr;20(2):141-4

Department of Molecular Biology and Immunology, Maratha Mandal's NGH Institute of Dental Sciences and Research Centre, Belgaum, Karnataka, India.

Background: Aggregatibacter actinomycetemcomitans (Aa), an important primary periodontal pathogen, is known for its strong virulence characteristics that cause periodontal disease. We investigated Aa occurrence in Indian individuals using culture and 16 s rDNA polymerase chain reaction (PCR).

Materials And Methods: A cross-sectional study with 100 participants each in the healthy and chronic periodontitis (CP) groups was conducted. The subgingival plaque was collected and immediately plated on selective media for Aa. The remaining plaque samples were used for DNA extraction. PCR was performed using specific primers for Aa.

Statistical Analysis Used: The detection of bacteria and the clinical parameters between the groups were compared using the Mann-Whitney U-test. For assessing the agreement between the results of anaerobic culture and PCR, Kappa analyses were performed.

Results: Aa levels using culture and PCR was 51% and 69% in the CP group and 12% and 30% in the healthy group, respectively. The two groups showed significant differences (P < 0.00001). The detection accuracy of culture and PCR was assessed, and the coefficient of accuracy (k) was highly significant in the healthy (0.3103; P < 0.0001) and CP groups (0.1536; P < 0.0497).

Conclusions: Aa was predominantly found in the CP group compared with the healthy group, which is consistent with previous findings. Our results showed that both techniques can be used for detecting Aa. An ideal technique for detecting subgingival microorganisms should be carefully selected depending on the scope of the intended future work.
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http://dx.doi.org/10.4103/0972-124X.175171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847458PMC
May 2016

Comparison of the effectiveness of three retinal camera technologies for malarial retinopathy detection in Malawi.

Proc SPIE Int Soc Opt Eng 2016 Feb 4;9693. Epub 2016 Mar 4.

VisionQuest i-Rx Corporation, Albuquerque, NM, 87106-4358, USA.

The purpose of this study was to test the suitability of three available camera technologies (desktop, portable, and i-phone based) for imaging comatose children who presented with clinical symptoms of malaria. Ultimately, the results of the project would form the basis for a design of a future camera to screen for malaria retinopathy (MR) in a resource challenged environment. The desktop, portable, and i-phone based cameras were represented by the Topcon, Pictor Plus, and Peek cameras, respectively. These cameras were tested on N=23 children presenting with symptoms of cerebral malaria (CM) at a malaria clinic, Queen Elizabeth Teaching Hospital in Malawi, Africa. Each patient was dilated for binocular indirect ophthalmoscopy (BIO) exam by an ophthalmologist followed by imaging with all three cameras. Each of the cases was graded according to an internationally established protocol and compared to the BIO as the clinical ground truth. The reader used three principal retinal lesions as markers for MR: hemorrhages, retinal whitening, and vessel discoloration. The study found that the mid-priced Pictor Plus hand-held camera performed considerably better than the lower price mobile phone-based camera, and slightly the higher priced table top camera. When comparing the readings of digital images against the clinical reference standard (BIO), the Pictor Plus camera had sensitivity and specificity for MR of 100% and 87%, respectively. This compares to a sensitivity and specificity of 87% and 75% for the i-phone based camera and 100% and 75% for the desktop camera. The drawback of all the cameras were their limited field of view which did not allow complete view of the periphery where vessel discoloration occurs most frequently. The consequence was that vessel discoloration was not addressed in this study. None of the cameras offered real-time image quality assessment to ensure high quality images to afford the best possible opportunity for reading by a remotely located specialist.
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http://dx.doi.org/10.1117/12.2213282DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6819002PMC
February 2016

Prevalence of Herpesvirus and Correlation with Clinical Parameters in Indian Subjects with Chronic Periodontitis.

J Contemp Dent Pract 2015 11 1;16(11):915-20. Epub 2015 Nov 1.

Department of Molecular Biology and Immunology, Maratha Mandal's NGH Institute of Dental Sciences and Research Centre, Belgaum, Karnataka, India.

Objective: The identification of new uncultured species and viruses supports the possibility of combination of the herpes-virus-bacterial periodontal infection for periodontitis. The paucity of data and studies with larger sample size in Indian subjects provides an unclear picture of the presence of the herpesvirus in this population.

Materials And Methods: This was a cross-sectional study consisting of 100 each in the healthy group and chronic periodontitis (CP) group. The subgingival plaque was collected and polymerase chain reaction was performed post deoxyribonucleic acid (DNA) extraction by using specific primers for human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The data were analyzed using Fisher's exact test, Mann-Whitney U test and Spearman's coefficient correlation.

Results: Human cytomegalovirus and EBV viruses were significantly higher in the CP group as compare to the healthy group. A higher percentage of those with CMV positive had EBV also positive (28.3%) compared to only 9.1% of CMV negative being EBV positive in the CP group. When both the healthy and CP group in total was compared, there was a significant correlation with all clinical parameters.

Conclusion: Both the viruses dominated in disease as compared to health were similar to the earlier findings. The CP group had higher pocket depth and clinical attachment loss in the virus positive subjects. These findings could suggest that virus serves as a prelude to the disease and the combination of the two viruses could play a role in the pathogenesis.
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http://dx.doi.org/10.5005/jp-journals-10024-1781DOI Listing
November 2015

Comprehensive automatic assessment of retinal vascular abnormalities for computer-assisted retinopathy grading.

Annu Int Conf IEEE Eng Med Biol Soc 2014 ;2014:6320-3

One of the most important signs of systemic disease that presents on the retina is vascular abnormalities such as in hypertensive retinopathy. Manual analysis of fundus images by human readers is qualitative and lacks in accuracy, consistency and repeatability. Present semi-automatic methods for vascular evaluation are reported to increase accuracy and reduce reader variability, but require extensive reader interaction; thus limiting the software-aided efficiency. Automation thus holds a twofold promise. First, decrease variability while increasing accuracy, and second, increasing the efficiency. In this paper we propose fully automated software as a second reader system for comprehensive assessment of retinal vasculature; which aids the readers in the quantitative characterization of vessel abnormalities in fundus images. This system provides the reader with objective measures of vascular morphology such as tortuosity, branching angles, as well as highlights of areas with abnormalities such as artery-venous nicking, copper and silver wiring, and retinal emboli; in order for the reader to make a final screening decision. To test the efficacy of our system, we evaluated the change in performance of a newly certified retinal reader when grading a set of 40 color fundus images with and without the assistance of the software. The results demonstrated an improvement in reader's performance with the software assistance, in terms of accuracy of detection of vessel abnormalities, determination of retinopathy, and reading time. This system enables the reader in making computer-assisted vasculature assessment with high accuracy and consistency, at a reduced reading time.
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http://dx.doi.org/10.1109/EMBC.2014.6945074DOI Listing
October 2015

Detection of hypertensive retinopathy using vessel measurements and textural features.

Annu Int Conf IEEE Eng Med Biol Soc 2014 ;2014:5406-9

Features that indicate hypertensive retinopathy have been well described in the medical literature. This paper presents a new system to automatically classify subjects with hypertensive retinopathy (HR) using digital color fundus images. Our method consists of the following steps: 1) normalization and enhancement of the image; 2) determination of regions of interest based on automatic location of the optic disc; 3) segmentation of the retinal vasculature and measurement of vessel width and tortuosity; 4) extraction of color features; 5) classification of vessel segments as arteries or veins; 6) calculation of artery-vein ratios using the six widest (major) vessels for each category; 7) calculation of mean red intensity and saturation values for all arteries; 8) calculation of amplitude-modulation frequency-modulation (AM-FM) features for entire image; and 9) classification of features into HR and non-HR using linear regression. This approach was tested on 74 digital color fundus photographs taken with TOPCON and CANON retinal cameras using leave-one out cross validation. An area under the ROC curve (AUC) of 0.84 was achieved with sensitivity and specificity of 90% and 67%, respectively.
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http://dx.doi.org/10.1109/EMBC.2014.6944848DOI Listing
October 2015

Smoking decreases structural and functional resilience in the subgingival ecosystem.

J Clin Periodontol 2014 Nov 29;41(11):1037-47. Epub 2014 Sep 29.

Division of Periodontology, College of Dentistry, The Ohio State University, Columbus, OH, USA.

Aims: Dysbiotic microbial communities underlie the aetiology of several oral diseases, especially in smokers. The ability of an ecosystem to rebound from the dysbiotic state and re-establish a health-compatible community, a characteristic known as resilience, plays an important role in susceptibility to future disease. The present investigation was undertaken to examine the effects of smoking on colonization dynamics and resilience in marginal and subgingival biofilms.

Materials And Methods: Marginal and subgingival plaque and gingival crevicular fluid samples were collected from 25 current and 25 never smokers with pre-existing gingivitis at baseline, following resolution, after 1, 2 4, 7, 14 and 21 days of undisturbed plaque formation and following resolution. 16S cloning and sequencing was used for bacterial identification and multiplexed bead-based flow cytometry was used to quantify the levels of 27 immune mediators.

Results: Smokers demonstrated an early pathogenic colonization that led to sustained pathogen enrichment with periodontal and respiratory pathogens, eliciting a florid immune response. Smokers also demonstrated greater abundance of pathogenic species, poor compositional correlation between marginal and subgingival ecosystems, and significantly greater pro-inflammatory responses following resolution of the second episode of disease.

Conclusions: The ability of the subgingival microbiome to "reset" itself following episodes of disease is decreased in smokers, thereby lowering the resilience of the ecosystem and decreasing its resistance to future disease.
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http://dx.doi.org/10.1111/jcpe.12300DOI Listing
November 2014

Automated method for identification and artery-venous classification of vessel trees in retinal vessel networks.

PLoS One 2014 12;9(2):e88061. Epub 2014 Feb 12.

Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States of America ; Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa, United States of America ; Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States of America ; The Iowa City Veteran's Medical Center, Iowa City, Iowa, United States of America.

The separation of the retinal vessel network into distinct arterial and venous vessel trees is of high interest. We propose an automated method for identification and separation of retinal vessel trees in a retinal color image by converting a vessel segmentation image into a vessel segment map and identifying the individual vessel trees by graph search. Orientation, width, and intensity of each vessel segment are utilized to find the optimal graph of vessel segments. The separated vessel trees are labeled as primary vessel or branches. We utilize the separated vessel trees for arterial-venous (AV) classification, based on the color properties of the vessels in each tree graph. We applied our approach to a dataset of 50 fundus images from 50 subjects. The proposed method resulted in an accuracy of 91.44% correctly classified vessel pixels as either artery or vein. The accuracy of correctly classified major vessel segments was 96.42%.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0088061PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3922768PMC
January 2015

Deep sequencing identifies ethnicity-specific bacterial signatures in the oral microbiome.

PLoS One 2013 23;8(10):e77287. Epub 2013 Oct 23.

Division of Oral Biology, College of Dentistry, The Ohio State University, Columbus, Ohio, United States of America.

Oral infections have a strong ethnic predilection; suggesting that ethnicity is a critical determinant of oral microbial colonization. Dental plaque and saliva samples from 192 subjects belonging to four major ethnicities in the United States were analyzed using terminal restriction fragment length polymorphism (t-RFLP) and 16S pyrosequencing. Ethnicity-specific clustering of microbial communities was apparent in saliva and subgingival biofilms, and a machine-learning classifier was capable of identifying an individual's ethnicity from subgingival microbial signatures. The classifier identified African Americans with a 100% sensitivity and 74% specificity and Caucasians with a 50% sensitivity and 91% specificity. The data demonstrates a significant association between ethnic affiliation and the composition of the oral microbiome; to the extent that these microbial signatures appear to be capable of discriminating between ethnicities.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0077287PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3806732PMC
February 2015

Automated detection of malarial retinopathy-associated retinal hemorrhages.

Invest Ophthalmol Vis Sci 2012 Sep 25;53(10):6582-8. Epub 2012 Sep 25.

Department of Biomedical Engineering, University of Iowa, Iowa City, IA, USA.

Purpose: To develop an automated method for the detection of retinal hemorrhages on color fundus images to characterize malarial retinopathy, which may help in the assessment of patients with cerebral malaria.

Methods: A fundus image dataset from 14 patients (200 fundus images, with an average of 14 images per patient) previously diagnosed with malarial retinopathy was examined. We developed a pattern recognition-based algorithm, which extracted features from image watershed regions called splats (tobogganing). A reference standard was obtained by manual segmentation of hemorrhages, which assigned a label to each splat. The splat features with the associated splat label were used to train a linear k-nearest neighbor classifier that learnt the color properties of hemorrhages and identified the splats belonging to hemorrhages in a test dataset. In a crossover design experiment, data from 12 patients were used for training and data from two patients were used for testing, with 14 different permutations; and the derived sensitivity and specificity values were averaged.

Results: The experiment resulted in hemorrhage detection sensitivities in terms of splats as 80.83%, and in terms of lesions as 84.84%. The splat-based specificity was 96.67%, whereas for the lesion-based analysis, an average of three false positives was obtained per image. The area under the receiver operating characteristic curve was reported as 0.9148 for splat-based, and as 0.9030 for lesion-based analysis.

Conclusions: The method provides an automated means of detecting retinal hemorrhages associated with malarial retinopathy. The results matched well with the reference standard. With further development, this technique may provide automated assistance for screening and quantification of malarial retinopathy.
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http://dx.doi.org/10.1167/iovs.12-10191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3460387PMC
September 2012

Host-bacterial interactions during induction and resolution of experimental gingivitis in current smokers.

J Periodontol 2013 Jan 16;84(1):32-40. Epub 2012 Mar 16.

Division of Periodontology, College of Dentistry, The Ohio State University, Columbus, OH, USA.

Background: Changes in clinical profiles, microbial succession, and immune mediator fluctuations have all been separately examined during onset and resolution of experimental gingivitis in smokers. However, because both the bacterial challenge and the host response contribute to periodontal disease, the purpose of this investigation is to simultaneously examine clinical, bacterial, and immune changes that occur during the onset and resolution of disease in smokers.

Methods: Experimental gingivitis was induced in 15 smokers for 21 days, followed by treatment with a sonic toothbrush for 21 days. Marginal and subgingival plaque and gingival crevicular fluid samples were collected at baseline; after 7, 14, and 21 days of undisturbed plaque formation; and 21 days after reinstitution of brushing. 16S cloning and sequencing was used for bacterial quantification, and multiplexed bead-based flow cytometry was used to quantify the levels of 27 immune mediators.

Results: Onset of clinical gingivitis was preceded by significant changes in the marginal and subgingival biofilms, with a decrease in the abundance of early colonizers, namely, Streptococcus, Veillonella, and Pseudomonas, and an increase in levels of periodontopathogens, such as Treponema, Selenomonas, Parvimonas, Dialister, and Campylobacter. This was accompanied by a decrease in anti-inflammatory, chemokine, and T-helper 2 (Th2) responses and altered Th1/Th2 ratios. Although the bacterial communities continued to shift in the same direction after onset of clinical gingivitis and returned to baseline levels after resolution of disease, the anti-inflammatory, chemokine, and Th2 profiles demonstrated an increase from day 14 that continued even after clinical health was evident.

Conclusion: Both marginal and subgingival biofilms in smokers are characterized by early acquisition of pathogenic organisms, which elicit a sustained host response that persists even after removal of the bacterial challenge.
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http://dx.doi.org/10.1902/jop.2012.110662DOI Listing
January 2013

Tobacco smoking affects bacterial acquisition and colonization in oral biofilms.

Infect Immun 2011 Nov 22;79(11):4730-8. Epub 2011 Aug 22.

Division of Periodontology, College of Dentistry, The Ohio State University, Columbus, Ohio, USA.

Recent evidence suggests that smoking affects the composition of the disease-associated subgingival biofilm, yet little is known about its effects during the formation of this biofilm. The present investigation was undertaken to examine the contributions of smoking to the composition and proinflammatory characteristics of the biofilm during de novo plaque formation. Marginal and subgingival plaque and gingival crevicular fluid samples were collected from 15 current smokers and from 15 individuals who had never smoked (nonsmokers) following 1, 2, 4, and 7 days of undisturbed plaque formation. 16S rRNA gene cloning and sequencing were used for bacterial identification, and multiplex bead-based flow cytometry was used to quantify the levels of 27 immune mediators. Smokers demonstrated a highly diverse, relatively unstable initial colonization of both marginal and subgingival biofilms, with lower niche saturation than that seen in nonsmokers. Periodontal pathogens belonging to the genera Fusobacterium, Cardiobacterium, Synergistes, and Selenomonas, as well as respiratory pathogens belonging to the genera Haemophilus and Pseudomonas, colonized the early biofilms of smokers and continued to persist over the observation period, suggesting that smoking favors early acquisition and colonization of pathogens in oral biofilms. Smokers also demonstrated an early proinflammatory response to this colonization, which persisted over 7 days. Further, a positive correlation between proinflammatory cytokine levels and commensal bacteria was observed in smokers but not in nonsmokers. Taken together, the data suggest that smoking influences both the composition of the nascent biofilm and the host response to this colonization.
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http://dx.doi.org/10.1128/IAI.05371-11DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257914PMC
November 2011

Retinal arterial but not venous tortuosity correlates with facioscapulohumeral muscular dystrophy severity.

J AAPOS 2010 Jun;14(3):240-3

Department of Ophthalmology, University of Iowa Hospitals and Clinics, Iowa City, Iowa, USA.

Background: Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal-dominant disease beginning with facial and shoulder girdle weakness with variable progression. Exudative retinal detachment, retinal vessel irregularities on fluorescein angiography, and retinal vessel tortuosity have been found in association with FSHD.

Methods: In this retrospective study, muscle affectedness severity was rated as mild, moderate, or severe by a neurologist masked to the retinal images. Three ophthalmologists masked to disease severity graded the degree of arterial and venous tortuosity on a scale of 1 to 4. An automated method estimated an index of tortuosity for arteries and veins from color fundus photographs. Spearman rank correlation coefficients were used to describe the relationship between retinal vessel tortuosity and disease severity.

Results: Seven patients with an average age of 13 years (range, 7-36 years) were selected. Correlation between the subjective tortuosity for arteries, and the severity of FSHD was 0.78 (p = 0.039). The correlation coefficient for venous tortuosity was -0.06 and was not significant (p = 0.882). The correlation coefficient between the average algorithmic computer-generated tortuosity indices for arteries and FSHD severity was high (0.85, p = 0.016), but for veins it was low and not significant (0.19, p = 0.662).

Conclusions: The authors of previous reports have shown retinal vascular abnormalities did not correlate to FSHD disease severity. Our results suggest a correlation between the tortuosity of arteries and the severity of disease in FSHD patients. These results suggest the tortuosity of arteries can serve as a biomarker of severity of disease in these FSHD patients, either as determined by human experts or by an automated method.
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http://dx.doi.org/10.1016/j.jaapos.2010.03.006DOI Listing
June 2010

The detection of eight putative periodontal pathogens in adult and rapidly progressive periodontitis patients: an institutional study.

Indian J Dent Res 2007 Jan-Mar;18(1):6-10

Dept. of Oral Biology, School of Dental Medicine, SUNY at Stony Brook, NY 11794-8700, USA.

Purpose: Periodontal disease is a commonly prevalent problem faced alike by both the developed and third world countries but showing wide variations in prevalence and severity across different geographical areas. The purpose was to identify Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Ekinella corrodens (Ec), Campylobacter rectus (Cr), Bacteroides forsythus (Bf), Treponema denticola (Td) and Fusobacterium nucleatum (Fn) in Indian adult periodontitis and rapidly progressive periodontitis patients.

Materials And Methods: Paper points were used to collect the sample from 28 sites in both adult periodontitis and rapidly progressive periodontitis (8 healthy/20 diseased sites) patients and DNA analysis done. The categorical data was analysed by Fishers exact test and difference in the clinical parameters was tested by Mann-Whitney test.

Results: In healthy sites of adult and rapidly progressive periodontitis patients, Aa, Ec, Bf and Aa, Pg, Pi, Td, Fn were detected respectively. However, when diseased and healthy sites were compared in both adult periodontitis and rapidly progressive periodontitis patients respectively, only Pg( P =0.004), Cr( P =0.04), Fn( P =0.014) and Pg( P =0.002), Cr( P =0.02), Fn( P =0.008) were statistically significant.

Conclusion: The prevalence of the microorganisms correlate with the clinical parameters like probing depth and bleeding on probing as seen in the Japanese and Western periodontitis patients' population.
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http://dx.doi.org/10.4103/0970-9290.30914DOI Listing
June 2007

DNA probe analysis in smoker and non smoker rapidly progressive periodontitis patients--a pilot study.

Indian J Dent Res 2003 Oct-Dec;14(4):279-83

Dept. of Periodontics, College of Dental Sciences, Davangere-57004, Karanataka, India.

Smoking is one of the most significant risk factors in the development and further advancement of inflammatory periodontal disease. The bacteria A. actinomycetemcomitans, P. gingivalis and P. intermedius as indicated as the potential pathogens associated with periodontal disease. Since the bacteria mentioned as well as smoking are factors associated with periodontitis it is of importance to elucidate the interrelationship between these factors. The purpose of this study was to investigate the prevalence of A. actinomycetemcomitans, P. gingivalis and P. intermedius in subgingival plaque samples obtained form healthy and diseased sites of patients with rapidly progressive periodontitis who were smokers and non smokers along with other clinical parameters.
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September 2004