Publications by authors named "Gabriel Castillo"

34 Publications

Use, Yield, and Risk of Device-assisted Enteroscopy in the United States: Results From a Large Retrospective Multicenter Cohort.

J Clin Gastroenterol 2020 Sep 17. Epub 2020 Sep 17.

Division of Gastroenterology, Duke University Medical Center.

Introduction: Since 2001, device-assisted enteroscopy (DAE) has revolutionized the diagnostic and therapeutic capabilities for managing small bowel pathology. Though commonly performed, there have been no recent large studies to assess the use, yield, and risks of DAE and none that include all 3 DAE modalities. We hypothesized that DAE is safe with high diagnostic and therapeutic yields achieved within reasonable procedure duration and here we present a large retrospective multicenter US study evaluating the use, yield, and complications of DAE.

Methods: After obtaining institutional review board approval, electronic records were used to identify all DAE's performed for luminal small bowel evaluation in adult patients at 4 US referral centers (Duke University Medical Center, New York University Langone Medical Center, Louisiana State University Health Sciences Center, and University of Massachusetts Medical Center) from January 1, 2014 to January 1, 2019. Electronic medical records were reviewed to collect and analyze a variety of procedure-related outcomes. Using the data pooled across centers, descriptive statistics were generated for the patient and procedure-related characteristics and outcomes; relationships between characteristics and outcomes were explored.

Results: A total of 1787 DAE's were performed over this 5-year period (392 at Duke University Medical Center, 887 at Louisiana State University Health Sciences Center, 312 at New York University Langone Medical Center, and 195 at University of Massachusetts Medical Center). Of these, there were 1017 (57%) double-balloon, 391 (29%) single-balloon, and 378 (21%) spiral enteroscopies. The mean age of patients undergoing DAE was 66 years and 53% of examinations were performed on women; 18% of patients in the cohort underwent >1 DAE over this time span. A total of 53% of examinations were performed for suspected small bowel bleeding, 31% were directly guided by video capsule endoscopy findings and 8% were performed for abnormal imaging. A total of 85% of examinations used an antegrade approach and DAE took a mean of 45 minutes to complete; 76% of examinations revealed abnormal findings, with vascular, inflammatory, and neoplastic findings seen in 49%, 17%, and 15% of the cohort, respectively. Older age was significantly associated with any abnormal finding, including arteriovenous malformations (P<0.0001); 50% of examinations included a therapeutic maneuver, most commonly argon plasma coagulation/cautery (43%). There were complications in 16 examinations (0.9%) including 2 perforations (0.1%), 6 cases with bleeding (0.3%) and 1 episode of pancreatitis (0.1%).

Conclusions: DAE is most commonly performed to evaluate suspected small bowel bleeding and is commonly directed by video capsule findings. DAE is safe, has a high diagnostic yield, with 76% of examinations showing abnormal findings, and frequently features therapeutic maneuvers. Advancing age is associated with abnormal findings on DAE.
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http://dx.doi.org/10.1097/MCG.0000000000001426DOI Listing
September 2020

Prevalence, Predictors, and Disease Activity of Sacroiliitis Among Patients with Crohn's Disease.

Inflamm Bowel Dis 2021 May;27(6):809-815

NYU Langone Health, Department of Medicine, Division of Gastroenterology, New York, NY, USA.

Background: Sacroiliitis is an inflammatory arthritis of the sacroiliac joints and is associated with inflammatory bowel disease (IBD). Yet, sacroiliitis often goes undiagnosed in IBD, and the clinical association between IBD disease activity and sacroiliitis is not well established. Patients with Crohn's disease (CD) often receive magnetic resonance enterography (MRE) to assess disease activity, affording clinicians the opportunity to evaluate for the presence of sacroiliitis. We aimed to identify the prevalence and disease characteristics associated with sacroiliitis in CD patients undergoing MRE.

Methods: All CD patients undergoing MRE for any indication between 2014 and 2018 at an IBD referral center were identified. The MREs were reviewed for the presence of sacroiliitis based on bone marrow edema (BME) and structural lesions. We analyzed demographics, IBD characteristics, clinical and endoscopic disease activity, and management between CD patients with and without sacroiliitis.

Results: Two hundred fifty-eight patients with CD underwent MRE during the study period. Overall, 17% of patients had MR evidence of sacroiliitis, of whom 73% demonstrated bone marrow edema. Female gender, back pain, and later age of CD diagnosis were associated with sacroiliitis (P = 0.05, P < 0.001, P = 0.04, respectively). Disease location and CD therapy were not associated with sacroiliitis on MRE. Clinical, endoscopic, and radiographic disease activity were not associated with sacroiliitis on MRE.

Conclusion: Sacroiliitis is a common comorbid condition in CD. With limited clinical clues and disease characteristics to suggest sacroiliitis, physicians may utilize MRE to identify sacroiliitis, especially in CD patients with back pain.
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http://dx.doi.org/10.1093/ibd/izaa198DOI Listing
May 2021

Gastrointestinal Bleeding in a Patient With Gastric Lymphoma, Tuberculosis Enteritis, and Cytomegalovirus Enteritis.

ACG Case Rep J 2020 Feb 20;7(2):e00317. Epub 2020 Feb 20.

Division of Gastroenterology and Hepatology, Department of Medicine, NYU Langone Medical Center, New York, NY.

Bleeding from the small bowel can be challenging to identify by endoscopic or radiographic evaluation. We present the case of a patient with incompletely treated latent tuberculosis and medical history of T-cell lymphoma who developed gastrointestinal bleeding because of concurrent Burkitt lymphoma, tuberculosis enteritis, and cytomegalovirus enteritis. The interplay of these 3 diagnoses is discussed.
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http://dx.doi.org/10.14309/crj.0000000000000317DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7145173PMC
February 2020

[Parsonage-Turner syndrome. Report of one case].

Rev Med Chil 2019 Oct;147(10):1335-1339

Servicio de Cardiología y Cardiocirugía, Clínica Indisa, Santiago, Chile.

We report a 59-year-old male who, three weeks after a coronary revascularization surgery, reported a sudden intense burning pain in his left upper limb. Two weeks later, he reports a paresis with difficulty to extend his left wrist and fingers. The electromyography showed a severe axonal damage of the radial nerve with distal denervation signs. This clinical picture probably corresponds to a neuralgic amyotrophy, an inflammatory disorder of the brachial plexus known by a number of terms, including Parsonage-Turner syndrome.
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http://dx.doi.org/10.4067/s0034-98872019001001335DOI Listing
October 2019

Initial Experience in Chile with Stent Implantation in the Right Ventricle Outflow Tract in High-Risk Patients with Tetralogy of Fallot.

Pediatr Cardiol 2020 Apr 27;41(4):837-842. Epub 2020 Feb 27.

Cardiovascular Center Dr. Luis Calvo Mackenna Hospital, Chilean Public Health Network, Av. Antonio Varas Nº 360, 7500539, Santiago, Chile.

Tetralogy of Fallot (ToF) treatment is difficult in patients with surgical risk factors or unfavorable anatomy. Stent implantation in the right ventricular outflow tract (RVOT) is an option for these patients. We report our initial experience in Chile with RVOT stenting in patients with ToF. Retrospective and descriptive study conducted in three pediatric cardiovascular centers in Chile between 2012 and 2015, including all ToF patients with stent in the RVOT as first procedure. Clinical records, echocardiographic, interventional, and surgical reports were reviewed for demographics and information of RVOT and pulmonary arteries. 12 newborns with ToF were included (75% female). Median age was 20 days (1-70) and mean weight was 2178 g (1400-3414). Saturations increased after the procedure from 74.3% (55-88) to 88.5% (80-98%), (p < 0.01). No complications or mortality were related to interventions. Follow-up was 11 months (7-36). Median right and left pulmonary arteries Z-score increased from - 4.0 (- 5.2 to - 0.3) and - 1.5 (- 4.8 to - 0.26) to + 0.53 (0.0 to 2.2) and + 1.1 (0.5 to 2.9), (p < 0.05), respectively. Nakata index increased from 63 mm/mm (35 to 143) to 162 mm/mm (107 to 197), (p < 0.05). Surgical repair was performed at a median of 4 months (2-7). Transannular patch repair was necessary in all patients and there was no surgical mortality. RVOT stenting is a safe and useful option for patients with ToF and surgical risk factors or unfavorable anatomy. It increases the pulmonary blood flow, improving saturation and pulmonary artery growth as a bridge for surgical repair.
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http://dx.doi.org/10.1007/s00246-020-02321-2DOI Listing
April 2020

Checklist of nematode parasites of reptiles from Argentina.

Ann Parasitol 2020 ;66(4):425-432

Instituto de Invertebrados. Fundación Miguel Lillo, San Miguel de Tucumán, Argentina.

A summary of the parasitic nematodes of reptiles from Argentina is presented. It is a compilation of 29 parasitological papers published between 1992 and May 2020. This review includes information about 40 species of reptiles (4 snakes, 3 turtles, 1 anfisbaenian and 32 lizards). Twenty-six nematodes species have been reported from reptiles. The present review provides data on hosts, geographical distribution and site of infection. A host/parasite list is also provided.
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March 2021

[Plantar actinomycetoma in a patient without risk factors].

Rev Chilena Infectol 2019 Aug;36(4):531-535

Pontificia Universidad Católica de Chile, Santiago, Chile.

A case of plantar actinomycetoma without risk factors is presented, which was diagnosed by hystopatological analysis of a foot biopsy because of the suspicion of neoplasia. Since the patient did not fully respond to the first-line therapy antibiotics, a 24-weeks doxycycline regime was started, achieving a satisfactory response. Finally, a brief discussion on plantar mycetomas is presented.
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http://dx.doi.org/10.4067/S0716-10182019000400531DOI Listing
August 2019

Microstructure of starch-based meals with either palm or soybean oils alter in vitro starch digestibility with no major effects on glycaemic responses.

Int J Food Sci Nutr 2020 Aug 20;71(5):604-613. Epub 2019 Nov 20.

Faculty of Agricultural Sciences, Institute of Food Science and Technology, Universidad Austral de Chile, Valdivia, Chile.

Glycaemic response (GR) to starch-based meals depends on their food composition and microstructure. We studied the effect of palm and soybean oils on the microstructure of a solid starch-oil-gluten matrix, on the starch gelatinisation and digestibility. Additionally, a pilot cross-over study was carried out to assess GR after eating gelatinised starch/gluten-based foods with the addition of either palm or soybean oil in 8 young non-diabetic female volunteers (ISRCTN39636850). Both types of foods generated similar starch gelatinisation temperature. Starch/gluten-based food with soybean oil had rougher microstructure compared to food with palm oil, showing a higher initial and lower final digestion. Administration of starch/gluten-based meals with either palm or soybean oils to volunteers show very similar postprandial glucose or insulin responses. In conclusion, differences in fatty acid composition changes food microstructure and starch digestibility, with no major effects on glycaemic responses in female volunteers.
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http://dx.doi.org/10.1080/09637486.2019.1693521DOI Listing
August 2020

Abnormal distraction and load-specific connectivity during working memory in cognitively normal Parkinson's disease.

Hum Brain Mapp 2020 04 18;41(5):1195-1211. Epub 2019 Nov 18.

Department of Neurosciences, University of California, San Diego, California.

Visuospatial working memory impairments are common in Parkinson's disease (PD), yet the underlying neural mechanisms are poorly understood. The present study investigated abnormalities in context-dependent functional connectivity of working memory hubs in PD. Cognitively normal PD and control participants underwent fMRI while performing a visuospatial working memory task. To identify sources of dysfunction, distraction, and load-modulated connectivity were disentangled for encoding and retrieval phases of the task. Despite normal working memory performance in PD, two features of abnormal connectivity were observed, one due to a loss in normal context-related connectivity and another related to upregulated connectivity of hubs for which the controls did not exhibit context-dependent connectivity. During encoding, striatal-prefrontal coupling was lost in PD, both during distraction and high memory loads. However, long-range connectivity of prefrontal, medial temporal and occipital hubs was upregulated in a context-specific manner. Memory retrieval was characterized by different aberrant connectivity patterns, wherein precuneus connectivity was upregulated during distraction, whereas prefrontal couplings were lost as memory load approached capacity limits. Features of abnormal functional connectivity in PD had pathological and compensatory influences as they correlated with poorer working memory or better visuospatial skills. The results offer new insights into working memory-related signatures of aberrant cortico-cortical and corticostriatal functional connections, which may portend future declines in different facets of working memory.
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http://dx.doi.org/10.1002/hbm.24868DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7058508PMC
April 2020

A 2x folic acid treatment affects epigenetics and dendritic spine densities in SHSY5Y cells.

Biochem Biophys Rep 2019 Dec 17;20:100681. Epub 2019 Aug 17.

University of South Carolina Upstate Division of Natural Sciences and Engineering, 800 University Way, Spartanburg, SC, 29303, USA.

Many diseases are now associated with aberrant epigenetics and gene expression changes. Epigenetics can be modified by factors like diet. One dietary factor, folic acid, is consumed in various forms including supplements, energy drinks, and fortified grains. It was hypothesized high levels of folic acid would affect gene expression and enzyme activity of chromatin modifying enzymes as well as dendritic spine densities in a commonly utilized neuron model, the SHSY5Y cell. Decreased MBD2 and MECP2 were discovered upon treatment of SHSY5Y cells with a 2x folic acid dose. Corresponding decreases in dendritic spines were apparent in the 2x folic acid treated cells as well. Activity of DNMTs and H3K4 HMTs was altered. Further, H3K4me1, H3K4me3, H3K9Ac, and global DNA methylation were decreased in the 2x folic acid treated cells. Further studies are warranted to determine if the effects of excess folic acid are detrimental to organismal physiology.
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http://dx.doi.org/10.1016/j.bbrep.2019.100681DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6711848PMC
December 2019

New association between Amblyomma parvitarsum (Acari: Ixodidae) and the endemic lizard Liolaemus eleodori (Iguania: Liolaemidae) in Argentina

Ann Parasitol 2019 ;65(1):27-33

Laboratorio de Parasitología e Inmunología Instituto Nacional de Tecnología Agropecuaria Estación Experimental Agropecuaria, Rafaela, Santa Fe, Argentina

Records of lizard parasitizing ticks in Argentina are scarce and incomplete. We recorded a new population of Liolaemus eleodori, a lizard endemic to Argentina, parasitized by the hard tick Amblyomma parvitarsum. Hence, the objective of this study is to report this new association and enhance knowledge about its parasitism on reptiles of Argentina. To do this, we researched ectoparasitic loads. We determined different ecological predictors: intensity, mean intensity and prevalence. Our results provide the first data on the parasitism of nymphal stages on this lizard. We found a tick prevalence of 91.6% and a mean intensity of 2.45. Considering sexes, mean intensity was higher in females than in males. The gular region and lower ventral abdomen were the highest parasitized anatomical regions. This new record of the host-parasite association suggests that this relationship is not accidental, with this lizard species being central to the tick’s life cycle. Probably, the microhabitat of this lizard species is essential for the tick to reach high prevalence. Our study represents an important contribution and provides additional information on parasitism in lizards of Argentina.
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June 2019

Description of Ornithodoros montensis n. sp. (Acari, Ixodida: Argasidae), a parasite of the toad Rhinella arenarum (Amphibia, Anura: Bufonidae) in the Monte Desert of Argentina.

Exp Appl Acarol 2019 May 15;78(1):133-147. Epub 2019 May 15.

Instituto Nacional de Tecnología Agropecuaria, Estación Experimental Agropecuaria Rafaela and Consejo Nacional de Investigaciones Científicas y Técnicas, CC 22, CP 2300, Rafaela, Santa Fe, Argentina.

A new tick species of the genus Ornithodoros (Acari: Argasidae) was described from larvae collected on the toad Rhinella arenarum in a locality from Argentina belonging to the Monte Biogeographic Province. Ornithodoros montensis n. sp. was described based on morphological traits and sequences of the mitochondrial 16S rRNA gene. The diagnostic characters for this species are a combination of idiosoma oval, dorsal plate pyriform with posterior margin slightly concave, dorsal surface with 17 pairs of setae (7 anterolateral, 4 to 5 central and 5 to 6 posterolateral), ventral surface with 6 pairs of setae and 1 pair on anal valves, three pairs of sternal setae, postcoxal setae absent, and hypostome pointed apically with dental formula 3/3 in the anterior half and 2/2 posteriorly almost to base. Phylogenetic analysis of 16S rDNA sequences and a principal component analysis based on morphometric characters provided additional support to the description of O. montensis as an independent lineage within the genus Ornithodoros. Larvae of O. montensis are phylogenetically closely related to O. puertoricensis, O. rioplatensis, O. talaje s.s., O. guaporensis, O. hasei and O. atacamensis, all of them belonging to the "O. talaje group".
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http://dx.doi.org/10.1007/s10493-019-00372-6DOI Listing
May 2019

Altered Functional Interactions of Inhibition Regions in Cognitively Normal Parkinson's Disease.

Front Aging Neurosci 2018 23;10:331. Epub 2018 Oct 23.

Department of Radiology, University of California, San Diego, La Jolla, CA, United States.

Deficient inhibitory control in Parkinson's disease (PD) is often observed in situations requiring inhibition of impulsive or prepotent behaviors. Although activation of the right-hemisphere frontal-basal ganglia response inhibition network is partly altered in PD, disturbances in interactions of these regions are poorly understood, especially in patients without cognitive impairment. The present study investigated context-dependent connectivity of response inhibition regions in PD patients with normal cognition and control participants who underwent fMRI while performing a stop signal task. PD participants were tested off antiparkinsonian medication. To determine if functional disturbances depended on underlying brain structure, aberrant connectivity was correlated with brain volume and white-matter tissue diffusivity. We found no group differences in response inhibition proficiency. Yet the PD group showed functional reorganization in the long-range connectivity of inhibition regions, despite preserved within network connectivity. Successful inhibition in PD differed from the controls by strengthened connectivity of cortical regions, namely the right dorsolateral prefrontal cortex, pre-supplementary motor area and right caudal inferior frontal gyrus, largely with ventral and dorsal attention regions, but also the substantia nigra and default mode network regions. Successful inhibition in controls was distinguished by strengthened connectivity of the right rostral inferior frontal gyrus and subcortical inhibition nodes (right caudate, substantia nigra, and subthalamic nucleus). In both groups, the strength of context-dependent connectivity correlated with various indices of response inhibition performance. Mechanisms that may underlie aberrantly stronger context-specific connectivity include reduced coherence within reorganized systems, compensatory mechanisms, and/or the reorganization of intrinsic networks. In PD, but not controls, abnormally strengthened connectivity was linked to individual differences in underlying brain volumes and tissue diffusivity, despite no group differences in structural variables. The pattern of structural-functional associations suggested that subtle decreases in tissue diffusivity of underlying tracts and posterior cortical volumes may undermine the enhancement of normal cortical-striatal connectivity or cause strengthening in cortical-cortical connectivity. These novel findings demonstrate that functionally reorganized interactions of inhibition regions predates the development of inhibition deficits and clinically significant cognitive impairment in PD. We speculate that altered interactions of inhibition regions with attention-related networks and the dopaminergic system may presage future decline in inhibitory control.
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http://dx.doi.org/10.3389/fnagi.2018.00331DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6206214PMC
October 2018

Pattern of infection with Parapharyngodon riojensis Ramallo, Bursey, Goldberg 2002 (Nematoda: Pharyngodonidae) in the lizard Phymaturus extrilidus from Puna region, Argentina

Ann Parasitol 2018;64(2):83-88

Departamento de Biología, Facultad de Ciencias Exactas, Físicas y Naturales; Universidad Nacional de San Juan, Av. Ignacio de la Roza 590, 5402 San Juan, Argentina

The pattern of infection with the nematode Parapharyngodon riojensis in the lizard Phymaturus extrilidus in a Puna area, central-west Argentina was studied. No significant prevalence differences were found between sexes or seasons sampled. However, there were differences in mean intensity between the summer (dry period) and autumn (wet period) seasons. Mean intensity was higher in the moistest season, associated with low body condition in P. extrilidus. The genus Parapharyngodon has a direct life cycle, and environmental moisture could favor higher intensity in the rainy period. The present study provides the first data on the parasitic ecology of P. extrilidus from Argentina.
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http://dx.doi.org/10.17420/ap6402.137DOI Listing
October 2018

Codon usage revisited: Lack of correlation between codon usage and the number of tRNA genes in enterobacteria.

Biochem Biophys Res Commun 2018 08 5;502(4):450-455. Epub 2018 Jun 5.

Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, 8380453, Chile. Electronic address:

It is widely believed that if a high number of genes are found for any tRNA in a rapidly replicating bacteria, then the cytoplasmic levels of that tRNA will be high and an open reading frame containing a higher frequency of the complementary codon will be translated faster. This idea is based on correlations between the number of tRNA genes, tRNA concentration and the frequency of codon usage observed in a limited number of strains as well as from the fact that artificially changing the number of tRNA genes alters translation efficiency and consequently the amount of properly folded protein synthesized. tRNA gene number may greatly vary in a genome due to duplications, deletions and lateral transfer which in turn would alter the levels and functionality of many proteins. Such changes are potentially deleterious for fitness and as a result it is expected that changes in tRNA gene numbers should be accompanied by a modification of the frequency of codon usage. In contrast to this model, when comparing the number of tRNA genes and the frequency of codon usage of several Salmonella enterica and Escherichia coli strains we found that changes in the number of tRNA genes are not correlated to changes in codon usage. Furthermore, these changes are not correlated with a change in the efficiency of codon translation. These results suggest that once a genome gains or loses tRNA genes, it responds by modulating the concentrations of tRNAs rather than modifying its frequency of codon usage.
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http://dx.doi.org/10.1016/j.bbrc.2018.05.168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6024254PMC
August 2018

Aberrant Intrinsic Activity and Connectivity in Cognitively Normal Parkinson's Disease.

Front Aging Neurosci 2017 19;9:197. Epub 2017 Jun 19.

Cognitive Neuroimaging Laboratory, Research Service, VA San Diego Healthcare System, San DiegoCA, United States.

Disturbances in intrinsic activity during resting-state functional MRI (rsfMRI) are common in Parkinson's disease (PD), but have largely been studied in defined subnetworks. The cognitive significance of abnormal intrinsic activity is also poorly understood, as are abnormalities that precede the onset of mild cognitive impairment. To address these limitations, we leveraged three different analytic approaches to identify disturbances in rsfMRI metrics in 31 cognitively normal PD patients (PD-CN) and 30 healthy adults. Subjects were screened for mild cognitive impairment using the Movement Disorders Society Task Force Level II criteria. Whole-brain data-driven analytic approaches first analyzed the amplitude of low-frequency intrinsic fluctuations (ALFF) and regional homogeneity (ReHo), a measure of local connectivity amongst functionally similar regions. We then examined if regional disturbances in these metrics altered functional connectivity with other brain regions. We also investigated if abnormal rsfMRI metrics in PD-CN were related to brain atrophy and executive, visual organization, and episodic memory functioning. The results revealed abnormally increased and decreased ALFF and ReHo in PD-CN patients within the default mode network (posterior cingulate, inferior parietal cortex, parahippocampus, entorhinal cortex), sensorimotor cortex (primary motor, pre/post-central gyrus), basal ganglia (putamen, caudate), and posterior cerebellar lobule VII, which mediates cognition. For default mode network regions, we also observed a compound profile of altered ALFF and ReHo. Most regional disturbances in ALFF and ReHo were associated with strengthened long-range interactions in PD-CN, notably with regions in different networks. Stronger long-range functional connectivity in PD-CN was also partly expanded to connections that were outside the networks of the control group. Abnormally increased activity and functional connectivity appeared to have a pathological, rather than compensatory influence on cognitive abilities tested in this study. Receiver operating curve analyses demonstrated excellent sensitivity (≥90%) of rsfMRI variables in distinguishing patients from controls, but poor accuracy for brain volume and cognitive variables. Altogether these results provide new insights into the topology, cognitive relevance, and sensitivity of aberrant intrinsic activity and connectivity that precedes clinically significant cognitive impairment. Longitudinal studies are needed to determine if these neurocognitive associations presage the development of future mild cognitive impairment or dementia.
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http://dx.doi.org/10.3389/fnagi.2017.00197DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5474556PMC
June 2017

Thubunaea eleodori sp. nov. (Nematoda: Physalopteridae) from Liolaemus eleodori (Sauria: Liolaemidae) from Argentina.

Parasitol Res 2017 Jan 28;116(1):293-297. Epub 2016 Oct 28.

Diversidad y Biología de Vertebrados del Árido (DIBIOVA), Departamento de Biología, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de San Juan, Av. José I. de la Roza 590 Oeste, J5402DCS, San Juan, Argentina.

Thubunaea eleodori sp. nov. is described from the stomach of Liolaemus eleodori (Sauria: Liolaemidae) from San Guillermo National Park, Province of San Juan, Argentina. T. eleodori is most similar to those species lacking spicules, T. cnemidophorus, T. fitsimonsi, T. parkeri, T. schukurovi, and T. smogorzhewskii. T. eleodori is separated from these species based on the papilla pattern. T. eleodori has 12 pedunculate papillae and 14 sessile papillae, T. smogorzhewskii lacks pedunculate papillae, T. fitsimonsi and T. parkeri lack sessile papillae, and T. cnemidophorus has14-16 pedunculate papillae and 12 sessile papillae. T. eleodori represents the first member of the genus to be reported from Argentina.
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http://dx.doi.org/10.1007/s00436-016-5290-0DOI Listing
January 2017

Multilocus, DNA-based phylogenetic analyses reveal three new species lineages in the Phellinus gabonensis-P. caribaeo-quercicola species complex, including P. amazonicus sp. nov.

Mycologia 2016 09 29;108(5):939-953. Epub 2016 Jul 29.

Mycothèque de l'Université catholique de Louvain (MUCL, BCCM™), Earth and Life Institute-Université catholique de Louvain, Croix du Sud 2 bte L7.05.06, B-1348 Louvain-la-Neuve, Belgium

Species complexes in the poroid Hymenochaetaceae are well documented in the temperate areas. Potential species complexes are less known in tropical areas, however. In the last ten years, four phylogenetically and morphologically closely related species of Phellinus (Hymenochaetaceae) were described from various tropical/subtropical areas viz. P. caribaeo-quercicola, P. gabonensis, P. ellipsoideus, and P. castanopsidis They are characterized by cushion-shaped basidiomata, ventricose, commonly hamate hymenial setae, and broadly ellipsoid, thick-walled, pale yellowish basidiospores. Pursuing the studies of this complex, a phylogenetic approach based on DNA sequence data from the nuc rDNA regions ITS1-5.8S-ITS2 (ITS) and partial 28S (including the domains D1, D2, D3) and on part of the translation elongation factor 1-α (tef1, region between exons 4 and 8) revealed three new lineages or phylogenetic species. Two of these phylogenetic species are composed of exclusively on Neotropical specimens. One of them, described below as Phellinus amazonicus sp. nov., is represented by multiple collections originating from Neotropical, lowland, dense, moist forest at the western edge of the Amazon Basin in Ecuador, the Guiana Shield in French Guiana and (more likely) Trinidad. The second Neotropical phylogenetic species is represented in our phylogenetic analyses by a single collection from northeastern Argentina. It is also potentially known from two herbarium specimens originating from southern Brazil, for which no sequence data is available. It is left for now as Phellinus sp. 1, waiting to gather more specimens and DNA sequences data. The third new phylogenetic species is known by a single collection (pure culture) of uncertain origin. It is thought to represent Phellinus setulosus, a Southeast Asian taxa. From an evolutionary perspective, tree species occurring in the Neotropics (P. amazonicus, P. caribaeo-quercicola, and Phellinus sp. 1) have a closely related genetic background and form a well supported Neotropical lineage.
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http://dx.doi.org/10.3852/15-173DOI Listing
September 2016

New species of Parapharyngodon (Nematoda: Pharyngodonidae) in Phymaturus spp. (Iguania: Liolaemidae) from Argentina.

Acta Parasitol 2016 Sep;61(3):461-5

Parapharyngodon sanjuanensis sp. nov. (Nematoda: Pharyngodonidae) from the large intestines of Phymaturus punae and Phymaturus williamsi (Squamata: Liolaemidae) from province of San Juan, Argentina, is described and illustrated. Parapharyngodon sanjuanensis sp. nov. is the 54th species assigned to the genus and the 8th from the Neotropical region. It differs from other species in the genus in that males possess 8 caudal papillae, 6 of which are large and pedunculate, 2 are small, almost inconspicuous; anterior lip echinate, posterior lip bilobate; females possess prominent vulva and short stiff tail spike.
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http://dx.doi.org/10.1515/ap-2016-0062DOI Listing
September 2016

[Quantification of stress: incomplete information plus excessive triumphalism].

Authors:
Gabriel Castillo

Rev Neurol 2016 Apr;62(7):335

Universidad Manuela Beltran, Bogota DC, Colombia.

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April 2016

Reduced dorsal premotor cortex and primary motor cortex connectivity in older adults.

Neurobiol Aging 2015 Jan 15;36(1):301-3. Epub 2014 Aug 15.

Division of Neurology, Krembil Neuroscience Centre, Toronto Western Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada. Electronic address:

Motor functions decline with increasing age. The underlying mechanisms are still unclear and are likely to be multifactorial. There is evidence for disruption of white matter integrity with age, which affects cortico-cortical connectivity. Studies with transcranial magnetic stimulation found both inhibitory and facilitatory connections from dorsal premotor cortex (PMd) to the ipsilateral primary motor cortex (M1) in young adults. We investigated whether aging affects this connectivity in 15 older and 15 young healthy adults. Transcranial magnetic stimulation in a paired-pulse paradigm was used to test the connectivity between left PMd and M1. Motor evoked potential in the right first dorsal interosseous muscle was recorded. We found that both the inhibitory effect with low intensity PMd stimulation and the facilitatory effect with high intensity PMd stimulation observed in young adults were decreased in older adults. We conclude that the connectivity between PMd and ipsilateral M1 is reduced in older adults.
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http://dx.doi.org/10.1016/j.neurobiolaging.2014.08.017DOI Listing
January 2015

Monolithic crystalline cladding microstructures for efficient light guiding and beam manipulation in passive and active regimes.

Sci Rep 2014 Aug 7;4:5988. Epub 2014 Aug 7.

School of Physics, State Key Laboratory of Crystal Materials, and Key Laboratory of Particle Physics and Particle Irradiation (Ministry of Education), Shandong University, 250100 Jinan, Shandong, China.

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump of miniaturized waveguiding active structures offers a low-cost but intriguing solution for compact light-emitting devices. In this work, we demonstrate a novel family of three dimensional (3D) photonic microstructures monolithically integrated in a Nd:YAG laser crystal wafer. They are produced by the femtosecond laser writing, capable of simultaneous light waveguiding and beam manipulation. In these guiding systems, tailoring of laser modes by both passive/active beam splitting and ring-shaped transformation are achieved by an appropriate design of refractive index patterns. Integration of graphene thin-layer as saturable absorber in the 3D laser structures allows for efficient passive Q-switching of tailored laser radiations which may enable miniature waveguiding lasers for broader applications. Our results pave a way to construct complex integrated passive and active laser circuits in dielectric crystals by using femtosecond laser written monolithic photonic chips.
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http://dx.doi.org/10.1038/srep05988DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4124484PMC
August 2014

Dissociation of Neural Mechanisms for Intersensory Timing Deficits in Parkinson's Disease.

Timing Time Percept 2014 May;2(2):145-168

Department of Radiology, University of California San Diego, La Jolla, CA, USA.

This study investigated the ability of individuals with Parkinson's disease (PD) to synthesize temporal information across the senses, namely audition and vision. Auditory signals (A) are perceived as lasting longer than visual signals (V) when they are compared together, since attentsion is captured and sustained more easily than for visual information. We used the audiovisual illusion to probe for disturbances in brain networks that govern the resolution of time in two intersensory conditions that putatively differ in their attention demands. PD patients and controls judged the relative duration of successively presented pairs of unimodal (AA, VV) and crossmodal (VA, AV) signals whilst undergoing fMRI. There were four main findings. First, underestimation of time was exaggerated in PD when timing depended on controlled attention (AV), whereas subtle deficits were found when audition dominated and attention was more easily sustained (VA). Second, group differences in regional activation were observed only for the AV-unimodal comparison, where the PD group failed to modulate basal ganglia, anterior insula, and inferior cerebellum activity in accord with the timing condition. Third, the intersensory timing conditions were dissociated by patterns of abnormal functional connectivity. When intersensory timing emphasized controlled attention, patients showed weakened connectivity of the cortico-thalamus-basal ganglia (CTBG) circuit and the anterior insula with widespread cortical regions, yet enhanced cerebellar connectivity. When audition dominated intersensory timing, patients showed enhanced connectivity of CTBG elements, the anterior insula, and the cerebellum with the caudate tail and frontal cortex. Fourth, abnormal connectivity measures showed excellent sensitivity and specificity in accurately classifying subjects. The results demonstrate that intersensory timing deficits in PD were well characterized by context-dependent patterns of functional connectivity within a presumed core timing system (CTBG) and a ventral attention hub (anterior insula), and enhanced cerebellar connectivity irrespective of the hypothesized attention demands of timing.
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http://dx.doi.org/10.1163/22134468-00002025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7236402PMC
May 2014

Neural underpinnings of distortions in the experience of time across senses.

Front Integr Neurosci 2011 28;5:32. Epub 2011 Jul 28.

Research Service, Veterans Affairs San Diego Healthcare System San Diego, CA, USA.

Auditory signals (A) are perceived as lasting longer than visual signals (V) of the same physical duration when they are compared together. Despite considerable debate about how this illusion arises psychologically, the neural underpinnings have not been studied. We used functional magnetic resonance imaging (fMRI) to investigate the neural bases of audiovisual temporal distortions and more generally, intersensory timing. Adults underwent fMRI while judging the relative duration of successively presented standard interval-comparison interval (CI) pairs, which were unimodal (A-A, V-V) or crossmodal (V-A, A-V). Mechanisms of time dilation and compression were identified by comparing the two crossmodal pairs. Mechanisms of intersensory timing were identified by comparing the unimodal and crossmodal conditions. The behavioral results showed that auditory CIs were perceived as lasting longer than visual CIs. There were three novel fMRI results. First, time dilation and compression were distinguished by differential activation of higher-sensory areas (superior temporal, posterior insula, middle occipital), which typically showed stronger effective connectivity when time was dilated (V-A). Second, when time was compressed (A-V) activation was greater in frontal cognitive-control centers, which guide decision making. These areas did not exhibit effective connectivity. Third, intrasensory timing was distinguished from intersensory timing partly by decreased striatal and increased superior parietal activation. These regions showed stronger connectivity with visual, memory, and cognitive-control centers during intersensory timing. Altogether, the results indicate that time dilation and compression arise from the connectivity strength of higher-sensory systems with other areas. Conversely, more extensive network interactions are needed with core timing (striatum) and attention (superior parietal) centers to integrate time codes for intersensory signals.
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http://dx.doi.org/10.3389/fnint.2011.00032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3147157PMC
November 2011

Neurobehavioral mechanisms of temporal processing deficits in Parkinson's disease.

PLoS One 2011 Feb 25;6(2):e17461. Epub 2011 Feb 25.

Research, Neurology, and Radiology Services, Veterans Affairs San Diego Healthcare System, San Diego, California, United States of America.

Background: Parkinson's disease (PD) disrupts temporal processing, but the neuronal sources of deficits and their response to dopamine (DA) therapy are not understood. Though the striatum and DA transmission are thought to be essential for timekeeping, potential working memory (WM) and executive problems could also disrupt timing.

Methodology/findings: The present study addressed these issues by testing controls and PD volunteers 'on' and 'off' DA therapy as they underwent fMRI while performing a time-perception task. To distinguish systems associated with abnormalities in temporal and non-temporal processes, we separated brain activity during encoding and decision-making phases of a trial. Whereas both phases involved timekeeping, the encoding and decision phases emphasized WM and executive processes, respectively. The methods enabled exploration of both the amplitude and temporal dynamics of neural activity. First, we found that time-perception deficits were associated with striatal, cortical, and cerebellar dysfunction. Unlike studies of timed movement, our results could not be attributed to traditional roles of the striatum and cerebellum in movement. Second, for the first time we identified temporal and non-temporal sources of impaired time perception. Striatal dysfunction was found during both phases consistent with its role in timekeeping. Activation was also abnormal in a WM network (middle-frontal and parietal cortex, lateral cerebellum) during encoding and a network that modulates executive and memory functions (parahippocampus, posterior cingulate) during decision making. Third, hypoactivation typified neuronal dysfunction in PD, but was sometimes characterized by abnormal temporal dynamics (e.g., lagged, prolonged) that were not due to longer response times. Finally, DA therapy did not alleviate timing deficits.

Conclusions/significance: Our findings indicate that impaired timing in PD arises from nigrostriatal and mesocortical dysfunction in systems that mediate temporal and non-temporal control-processes. However, time perception impairments were not improved by DA treatment, likely due to inadequate restoration of neuronal activity and perhaps corticostriatal effective-connectivity.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0017461PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3045463PMC
February 2011

Recessive mutations in the INS gene result in neonatal diabetes through reduced insulin biosynthesis.

Proc Natl Acad Sci U S A 2010 Feb 28;107(7):3105-10. Epub 2010 Jan 28.

Endocrinology and Diabetes Research Group, Hospital de Cruces, Barakaldo, 48903 Spain.

Heterozygous coding mutations in the INS gene that encodes preproinsulin were recently shown to be an important cause of permanent neonatal diabetes. These dominantly acting mutations prevent normal folding of proinsulin, which leads to beta-cell death through endoplasmic reticulum stress and apoptosis. We now report 10 different recessive INS mutations in 15 probands with neonatal diabetes. Functional studies showed that recessive mutations resulted in diabetes because of decreased insulin biosynthesis through distinct mechanisms, including gene deletion, lack of the translation initiation signal, and altered mRNA stability because of the disruption of a polyadenylation signal. A subset of recessive mutations caused abnormal INS transcription, including the deletion of the C1 and E1 cis regulatory elements, or three different single base-pair substitutions in a CC dinucleotide sequence located between E1 and A1 elements. In keeping with an earlier and more severe beta-cell defect, patients with recessive INS mutations had a lower birth weight (-3.2 SD score vs. -2.0 SD score) and were diagnosed earlier (median 1 week vs. 10 weeks) compared to those with dominant INS mutations. Mutations in the insulin gene can therefore result in neonatal diabetes as a result of two contrasting pathogenic mechanisms. Moreover, the recessively inherited mutations provide a genetic demonstration of the essential role of multiple sequence elements that regulate the biosynthesis of insulin in man.
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http://dx.doi.org/10.1073/pnas.0910533107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2840338PMC
February 2010

The nature and time course of cortical activation following subthalamic stimulation in Parkinson's disease.

Cereb Cortex 2010 Aug 17;20(8):1926-36. Epub 2009 Dec 17.

Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada M5T 2S8.

We studied the time course and nature of interactions between the subthalamic nucleus (STN) and the motor cortex in 8 Parkinson disease (PD) patients with chronically implanted STN deep-brain stimulation (DBS) electrodes. We first identified the cortical evoked potentials following STN stimulation. The most consistent potential was positive wave with peak latency of 22.2 +/- 1.2 ms from stimulation of clinically effective contacts. We then stimulated the motor cortex with transcranial magnetic stimulation (TMS) at 2-15 ms and at the latency of the evoked potential ( approximately 23 ms) following STN DBS. TMS induced currents in 3 directions: lateral-medial (LM) direction activated corticospinal axons directly, posterior-anterior (PA), and anterior-posterior (AP) directions activated corticospinal neurons transynaptically. Motor-evoked potentials (MEP) elicited by AP and PA TMS were facilitated at short (2-4 ms) and medium latencies (21-24 ms). However, MEPs elicited by LM TMS were not modified by STN DBS. Short-latency antidromic stimulation of the corticosubthalamic projections and medium latency transmission likely through the basal ganglia-thalamocortical circuit led to cortical evoked potentials and increased motor cortex excitability at specific intervals following STN stimulation at clinically effective contacts. Cortical activation may be related to the clinical effects of STN DBS in PD.
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http://dx.doi.org/10.1093/cercor/bhp269DOI Listing
August 2010

Perenniporiella chaquenia sp. nov. and further notes on Perenniporiella and its relationships with Perenniporia (poriales, basidiomycota).

Mycologia 2009 Sep-Oct;101(5):657-73

IMBIV-CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina.

Perenniporiella chaquenia sp. nov. is described from Argentina. New records of P. pendula and P. micropora are discussed. A key to Perenniporiella species is presented. Preliminary phylogenetic relationships of Perenniporiella are inferred from parsimony and Bayesian analysis of a combined set of DNA sequence data (nuclear ribosomal partial LSU and ITS). It demonstrated that Perenniporiella forms a well resolved monophyletic clade distantly related to Perenniporia s.s. It also clearly showed that within Perenniporia as usually conceived other morphologically homogeneous group of taxa, such as the P. ochroleuca or P. vicina alliances, form well resolved clades, which could be recognized as distinct genera. The differentiation of the hyphal system and the basidiospores morphology are outlined as critical features for the definition of genera in the Perenniporia complex.
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http://dx.doi.org/10.3852/08-040DOI Listing
October 2009

Two phases of interhemispheric inhibition between motor related cortical areas and the primary motor cortex in human.

Cereb Cortex 2009 Jul 17;19(7):1654-65. Epub 2008 Nov 17.

Division of Neurology, Krembil Neuroscience Centre and Toronto Western Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada.

Interhemispheric inhibition (IHI) refers to the neurophysiological mechanism in which one hemisphere of the brain inhibits the opposite hemisphere. IHI can be studied by transcranial magnetic stimulation using a conditioning-test paradigm. We investigated IHI from 5 motor related cortical areas in the right hemisphere to the left primary motor cortex (M1). These areas are hand and face representations of M1, dorsal premotor cortex, somatosensory cortex, and dorsolateral prefrontal cortex. Test stimulus was delivered to the left M1 and conditioning stimulus (CS) was delivered to one of 5 motor related cortical areas in the right hemisphere. The time course of IHI, effects of different CS intensities and current directions on IHI were tested. Maximum IHI was found at interstimulus intervals of approximately 10 ms (short latency IHI, SIHI) and approximately 50 ms (long latency IHI, LIHI) for the motor related areas tested. LIHI could be elicited over a wide range of CS intensities, whereas SIHI required higher CS intensities. We conclude that there are 2 distinct phases of IHI from motor related cortical areas to the opposite M1 through the corpus callosum, and they are mediated by different neuronal populations.
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http://dx.doi.org/10.1093/cercor/bhn201DOI Listing
July 2009

Fomitiporia punctata (Basidiomycota, Hymenochaetales) and its presumed taxonomic synonyms in America: taxonomy and phylogeny of some species from tropical/subtropical areas.

Mycologia 2007 Sep-Oct;99(5):733-52

Mycothèque de l'Université catholique de Louvain, Université catholique de Louvain, Croix du Sud 3, B-1348 Louvain-la-Neuve, Belgium.

The status of the F. punctata complex in tropical/subtropical America, and more specifically in Cuba and the surrounding area, was partially assessed. Fomitiporia langloisii, Fomitiporia dryophila and Fomitiporia maxonii, three names long considered taxonomic synonyms of F. punctata, are recognized as representing three distinct species that are distinguished from the latter on the basis of morphological, molecular and ecological (biogeographical) data. The three species are described again and their preliminary phylogenetic relationships within Fomitiporia are discussed. Fomitiporia tabaquilio comb. nov. is proposed. The status of Fomitiporia in America and its present circumscription are discussed.
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http://dx.doi.org/10.3852/mycologia.99.5.733DOI Listing
April 2008