Task-specific oromandibular dystonia secondary to chewing Khat (Catha edulis)- A series of 35 cases.

BACKGROUND: The leaves of "Khat" (Catha edulis), an indigenous shrub of Yemen and Arabian Peninsula are habitually chewed by the inhabitants for psychostimulant properties. OBJECTIVE: To describe a unique task specific Oro-mandibular dystonia (OMD) in Yemenese men, with a temporal association with chewing "Khat". METHODS: Multicentric, retrospective analysis (2009-2020) of patients with OMD associated with "Khat" chewing, evaluating clinical features and response to Onabotulinum toxin A. RESULTS: 35 Yemenese men with a negative family history, normal neuroimaging mean age of 44.31(±3.21) years and prolonged (20.31 ± 3.27 years) history of chewing Khat, around 5.16(±0.80) hours/day presented with OMD-20 jaw opening, 13 jaw closing and 2 mixed affecting chewing (n = 6), speech (n = 3), or both (n = 26). Additional lingual dystonia was seen in five. CONCLUSIONS: Chewing of khat is a repetitive task involving the jaw musculature and may be one of the causative factors of this task specific OMD. Recognition can prevent disability in these regions.

CARASIL - A Review of Patients from India.

Cerebral small vessel disease (CSVD) is a well-known cause of vascular dementia. Though a majority of these cases are sporadic, familial monogenic causes are being frequently identified as well. Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is a rare autosomal recessive CSVD, caused by mutation in HTRA 1 gene on chromosome 10q (10q25.3-q26.2) in homozygous or compound heterozygous form. Indian literature has been quite scant with very few case reports of CARASIL, and only three familial cases were confirmed with mutational analysis. Testing facilities of HTRA 1 genetic mutation are now more widely available in India than before, and should be encouraged for appropriate patients. This would help in diagnosing, prognosticating and avoiding unnecessary further investigations and medications for these patients. We herein review the Indian scenario and our previously reported experiences of this disorder, while adding a case from north India with a befitting clinical history, family history, neuroimaging and documented HTRA1 genetic mutation.

Extraction and analysis of signatures from the Gene Expression Omnibus by the crowd.

Gene expression data are accumulating exponentially in public repositories. Reanalysis and integration of themed collections from these studies may provide new insights, but requires further human curation. Here we report a crowdsourcing project to annotate and reanalyse a large number of gene expression profiles from Gene Expression Omnibus (GEO). Through a massive open online course on Coursera, over 70 participants from over 25 countries identify and annotate 2,460 single-gene perturbation signatures, 839 disease versus normal signatures, and 906 drug perturbation signatures. All these signatures are unique and are manually validated for quality. Global analysis of these signatures confirms known associations and identifies novel associations between genes, diseases and drugs. The manually curated signatures are used as a training set to develop classifiers for extracting similar signatures from the entire GEO repository. We develop a web portal to serve these signatures for query, download and visualization.

Direct measurement of the oscillation frequency in an optical-tweezers trap by parametric excitation.

We demonstrate a novel technique for direct measurement of the oscillation frequency in an optical-tweezers trap. The technique uses the phenomenon of parametric resonance in an oscillator when the stiffness of the trapping potential is modulated. The trapped particle is a strongly damped oscillator; hence, the signature of parametric resonance is not an increase in the amplitude but an increase in the size of Brownian fluctuations. The trap frequency is measured with an accuracy of 0.1%, which is better than previous techniques and thus opens up new possibilities in experiments with optical tweezers.