Geographic contiguity and genetic affinity among five ethnic populations of Manipur,India: further molecular studies based on VNTR and STR loci

BACKGROUND: Apart from traditional markers studied among a few numerically small, geographically defined surveys among Mongoloid populations in northeastern parts of India, very little is known about their genomic diversity at the molecular level. PRIMARY OBJECTIVE: This study seeks to investigate how best the variable number tandem repeat (VNTR) and short tandem repeat (STR) loci together can detect the patterns of the genetic affinity among five geographically contiguous, linguistically and socio-culturally diverse Mongoloid-affiliated populations of Manipur in northeastern regions of India. SUBJECT AND METHODS: Blood samples were collected from unrelated and randomly selected volunteers of five ethnic populations (Meitei, Kuki, Naga, Hmar and Manipuri Muslim) from different parts of the state. Allelic variation in four minisatellite loci (D1S7, D4S139, D5S110 and D17S79) and three STR loci (vWA, FESFPS and F13AO1) was studied. RESULTS: Average heterozygosity values among the five groups for the minisatellite range from 68% to 94%, while the hypervariable three STR loci were between 60% and 88%. In the populations, all the studied loci were highly polymorphic, with almost no departure from Hardy-Weinberg equilibrium. The gene differentiation for the VNTR loci was lower and moderate (G(st) = 0.030) in comparison with microsatellites (G(st) = 0.043). The neighbour-joining method of clustering based on both type of molecular markers reveals a close cluster for the tribal groups of Kuki, Naga and Hmar, while Manipur Muslim stand distinct in both the trees. The clustering pattern obtained from the combined DNA marker loci matches more closely the pattern from STR loci than that obtained from VNTR loci. CONCLUSIONS: The results reinforce that using both VNTR and STR loci in detecting regional genetic affinity among the populations is more effective than using VNTR or STR independently, and also confirm the results obtained from the serological and electrophoretic data. However, the clustering pattern obtained from combined DNA markers is more in conformity with the pattern obtained by STR loci rather than with VNTR loci. Despite linguistic, geographical and cultural barriers, the populations show genetic affinity among the four populations except in the case of the migrant Manipur Muslim group.     

Antiquity, geographic contiguity and genetic affinity among Tibeto-Burman populations of India: a microsatellite study

BACKGROUND: The Tibeto-Burman (TB) populations are one of the four major linguistic population groups of India. They are considered belonging to different stocks and show wide variation in culture and language; however, their genetic relationship, antiquity and migration history among the regional populations has been little investigated. Molecular genetic studies are expected to clearly show the antiquity and genetic diversity of these populations. AIM: This paper seeks to understand the extent and magnitude of genetic affinities and diversities among 14 TB populations (12 Indian and two global groups), investigate the findings based on classical genetic markers and verify the historical accounts of their migration and genetic history based on 12 microsatellite markers. SUBJECTS AND METHODS: The allele frequency data for 12 STR loci of 13 Asian (Tibeto-Burman) populations were obtained from the literature and the Adi Pasi data was obtained by microsatellite typing of their blood samples. The 12 loci studied are D5S818, FGA, D8S1179, D21S11, D7S820, CSF1PO, D3S1358, THO1, D13S317, vWa, TPOX, D18S51. Three different distance measures, two phylogenetic trees and PCA plot have been employed to understand the genetic relationship of the studied populations. RESULTS: Average heterozygosity values range from 68 to 79% and the average G(ST) value is 4.7%. The dendrogram, based on the D(A) distance, shows the clustering of populations based on their diversities and geographical contiguity; the Mizoram and Arunachal Pradesh populations especially cluster together, populations from Sikkim form a separate subcluster and Manipur populations along with the Garo of West Bengal separate out from the other clusters. The Harpending and Ward regression model shows isolated populations positioned below the regression line and others, who experience external gene flow, placed above the line. The results support folklore migration accounts of their possible antiquity with the Tibetan and southern Chinese populations. CONCLUSIONS: Overall, geographic contiguity, punctuated by isolating barriers, is a major influencing factor of genetic affinity among the TB population; contiguous populations within a region show greater genetic relationship than with distant TB populations over a wide geographical area. The results of the microsatellite study also support the history of diverse routes of migration of these populations.     

What Have We Learned about Trial Design From NIMH-Funded Pragmatic Trials?

At the 2008 annual meeting of the American College of Neuropsychopharmacology (ACNP), a symposium was devoted to the following question: ‘what have we learned about the design of pragmatic clinical trials (PCTs) from the recent costly long-term, large-scale trials of psychiatric treatments?'' in order to inform the design of future trials. In all, 10 recommendations were generated placing emphasis on (1) appropriate conduct of pragmatic trials; (2) clinical, rather than, merely statistical significance; (3) sampling from the population clinicians are called upon to treat; (4) clinical outcomes of patients, rather than, on outcome measures; (5) use of stratification, controlling, or adjusting when necessary and not otherwise; (6) appropriate consideration of site differences in multisite studies; (7) encouragement of ‘post hoc'' exploration to generate (not test) hypotheses; (8) precise articulation of the treatment strategy to be tested and use of the corresponding appropriate design; (9) expanded opportunity for training of researchers and reviewers in RCT principles; and (10) greater emphasis on data sharing.     

Double-blind,proof-of-concept (POC) trial of Low-Field Magnetic Stimulation (LFMS) augmentation of antidepressant therapy in treatment-resistant depression (TRD)

Background

Low-Field Magnetic Stimulation (LFMS) is a novel, non-invasive, sub-threshold neuromodulation technique, shown in preliminary studies to have immediate mood elevating effects in both unipolar and bipolar depressed patients.

Discovery of Small Molecule Kappa Opioid Receptor Agonist and Antagonist Chemotypes through a HTS and Hit Refinement Strategy

Herein we present the outcome of a high throughput screening (HTS) campaign-based strategy for the rapid identification and optimization of selective and general chemotypes for both kappa (κ) opioid receptor (KOR) activation and inhibition. In this program, we have developed potent antagonists (IC(50) < 120 nM) or agonists of high binding affinity (K(i) < 3 nM). In contrast to many important KOR ligands, the compounds presented here are highly modular, readily synthesized and, in most cases, achiral. The four new chemotypes hold promise for further development into chemical tools for studying the KOR or as potential therapeutic lead candidates.     

A quantitative measure of handgrip myotonia in non‐dystrophic myotonia

Introduction: Non‐dystrophic myotonia (NDM) is characterized by myotonia without muscle wasting. A standardized quantitative myotonia assessment (QMA) is important for clinical trials. Methods: Myotonia was assessed in 91 individuals enrolled in a natural history study using a commercially available computerized handgrip myometer and automated software. Average peak force and 90% to 5% relaxation times were compared with historical normal controls studied with identical methods. Results: Thirty subjects had chloride channel mutations, 31 had sodium channel mutations, 6 had DM2 mutations, and 24 had no identified mutation. Chloride channel mutations were associated with prolonged first handgrip relaxation times and warm‐up on subsequent handgrips. Sodium channel mutations were associated with prolonged first handgrip relaxation times and paradoxical myotonia or warm‐up, depending on underlying mutations. DM2 subjects had normal relaxation times but decreased peak force. Sample size estimates are provided for clinical trial planning. Conclusion: QMA is an automated, non‐invasive technique for evaluating myotonia in NDM. Muscle Nerve 46: 482–489, 2012     

An interactive voice response diary for patients with non-dystrophic myotonia

Introduction: Non‐dystrophic myotonia (NDM) is caused by mutations in muscle chloride and sodium channels. Currently, there is no standardized instrument for documenting symptom frequency and severity in NDM. Methods: Subjects used an automated, interactive, telephone‐based voice response diary (IVR) to record frequency and severity of stiffness, weakness, pain, and tiredness once a week for 8 weeks, after their baseline visits. Results: We describe the IVR and report data on 76 subjects for a total of 385 person‐weeks. Overall there were 5.1 calls per subject. Forty‐eight subjects called in 5 or more times, and 14 called in 8 times. Stiffness was both the most frequent and severe symptom. Warm‐up and handgrip myotonia were associated with higher severity scores for stiffness. Conclusions: IVR is a convenient technology to allow patient reporting of repeated and real‐time symptom frequency and severity, and it is presently being used in a trial of mexiletine in NDM. Muscle Nerve 44: 30–35, 2011     

Subthalamic deep brain stimulation affects heading perception in Parkinson’s disease

Journal of Neurology - Parkinson’s disease (PD) presents with visuospatial impairment and falls. It is critical to understand how subthalamic deep brain stimulation (STN DBS) modulates...     

Early adversity in chronic depression: clinical correlates and response to pharmacotherapy

Background: There is growing evidence suggesting that early adversity may be a marker for a distinct pathway to major depressive disorder (MDD). We examined associations between childhood adversity and a broad variety of clinical characteristics and response to pharmacotherapy in a large sample of patients with chronic forms of MDD. Methods: Subjects included 808 patients with chronic forms of MDD (chronic MDD, double depression, or recurrent MDD with incomplete recovery between episodes and a total continuous duration of >2 years) who were enrolled in a 12‐week open‐label trial of algorithm‐guided pharmacotherapy. Baseline assessments included a semi‐structured diagnostic interview, and clinician‐ and self‐rated measures of depressive symptoms, social functioning, depressotypic cognitions, and personality traits, and childhood adversity. Patients were re‐evaluated every 2 weeks. Results: A longer duration of illness; earlier onset; greater number of episodes, symptom severity, self‐rated functional impairment, suicidality, and comorbid anxiety disorder; and higher levels of dysfunctional attitudes and self‐criticism were each associated with multiple forms of childhood adversity. A history of maternal overcontrol, paternal abuse, paternal indifference, sexual abuse, and an index of clinically significant abuse each predicted a lower probability of remission. Among patients completing the 12‐week trial, 32% with a history of clinically significant abuse, compared to 44% without such a history, achieved remission. Conclusions: These findings indicate that a history of childhood adversity is associated with an especially chronic form of MDD that is less responsive to antidepressant pharmacotherapy. Depression and Anxiety, 2009. Published 2009 Wiley‐Liss, Inc.