Cobalt-sulfur coordination chemistry drives B\u3csub\u3e12\u3c/sub\u3e loading onto methionine synthase

Cobalt-sulfur (Co-S) coordination is labile to both oxidation and reduction chemistry and is rarely seen in Nature. Cobalamin (or vitamin B12) is an essential cobalt-containing organometallic cofactor in mammals, and is escorted via an intricate network of chaperones to a single cytoplasmic target, methionine synthase. In this study, we report that the human cobalamin trafficking protein, MMADHC, exploits the chemical lability of Co-S coordination, for cofactor off-loading onto methionine synthase. Cys-261 on MMADHC serves as the -axial ligand to cobalamin. Complex formation between MMADHC and methionine synthase is signaled by loss of the lower axial nitrogen ligand, leading to five-coordinate thiolato-cobalamin. Nucleophilic displacement by the vicinal thiolate, Cys-262, completes cofactor transfer to methionine synthase and release of a cysteine disulfide-containing MMADHC. The physiological relevance of this mechanism is supported by clinical variants of MMADHC, which impair cofactor binding and off-loading, explaining the molecular basis of the associated homocystinuria

Air pollution monitoring using near room temperature resistive gas sensors : a review

The growth of industries and other human activities have led to ever increasing amounts of pollutants in both outdoor and indoor spaces. These pollutants have hazardous effects on humans and the wider ecology. Hence, air quality monitoring (AQM) is essential and involves the robust monitoring of various toxic gases and volatile organic compounds (VOCs)-in case the concentration of any pollutant exceeds the safe limit in a given location. This paper describes the different sources of indoor and outdoor pollutants, reviews the current status of gas sensors, and discusses the role of new two-dimensional (2D) materials in detecting these hazardous gases at low power, i.e. close to ambient temperature. Here we review different synthesis techniques of 2D materials and discuss the sensing performances of pristine and functionalized nanomaterials for some of the important pollutants like NOx, NH3, SOx, CO, formaldehyde and toluene. The review concludes with some proposed methods to help reduce air pollution today

Circulating Long Non-Coding RNAs Could Be the Potential Prognostic Biomarker for Liquid Biopsy for the Clinical Management of Oral Squamous Cell Carcinoma

Long non-coding RNA (lncRNA) have little or no coding potential. These transcripts are longer than 200 nucleotides. Since lncRNAs are master regulators of almost all biological processes, recent evidence proves that aberrantly expressed lncRNAs are pathogenic for oral squamous cell carcinoma (OSCC) and other diseases. LncRNAs influence chromatin modifications, transcriptional modifications, post-transcriptional modifications, genomic imprinting, cell proliferation, invasion, metastasis, and apoptosis. Consequently, they have an impact on the disease transformation, progression, and morbidity in OSCC. Therefore, circulating lncRNAs could be the potential cancer biomarker for the better clinical management (diagnosis, prognosis, and monitoring) of OSCC to provide advanced treatment strategies and clinical decisions. In this review, we report and discuss the recent understandings and perceptions of dysregulated lncRNAs with a focus on their clinical significance in OSCC-disease monitoring and treatment. Evidence clearly indicates that a specific lncRNA expression signature could act as an indicator for the early prediction of diagnosis and prognosis for the initiation, progression, recurrence, metastasis and other clinical prognostic-factors (overall survival, disease-free survival, etc.) in OSCC. The present review demonstrates the current knowledge that all potential lncRNA expression signatures are molecular biomarkers for the early prediction of prognosis in OSCC. Finally, the review provides information about the clinical significance, challenges and limitations of the clinical usage of circulating lncRNAs in a liquid biopsy method in early, pre-symptomatic, sub-clinical, accurate OSCC prognostication. More studies on lncRNA are required to unveil the biology of the inherent mechanisms involved in the process of the development of differential prognostic outcomes in OSCC

Differential Diagnosis of Lateral Neck Masses

Introduction: The neck and parapharyngeal space are one of the most vital regions in the body, encompassing multiple major blood vessels, nerves, spine and the airway itself. Lateral neck masses that present to an ENT practitioner may not only include a wide variety of differentials, but may present as emergencies in case of an airway compromise. In such situations, decision making and arriving at the diagnosis becomes important not only from a curative perspective but also from a lifesaving one. Here we discuss a few cases of lateral neck masses that had presented to us with unusual presentation or had a rare diagnosis, along with the line of management that was followed. Cases: We present a case of a giant pleomorphic adenoma presenting with stridor, an adult onset cystic hygroma, a schwannoma presenting with dyspnea, an isolated infiltrating lipoma and 2 other cases of schwannoma. Conclusion: Tumours of the neck and parapharyngeal region have a wide variety as this region contains almost every kind of tissue. Diagnosis of any lesion should be done with caution, using the appropriate history, examination and investigative tools available. Not only the common presentation, but also outliers and uncommon presentations of common tumours should be kept in mind

Comparison of the effectiveness and safety of Clarithromycin and Co-Amoxyclav in acute exacerbation of chronic otitis media : a randomized, open-labeled, phase iv clinical trial

Objective:To compare the effectiveness and safety of Clarithromycin and co-amoxyclav for the treatment of mild to moderate cases of acute exacerbation of chronic otitis media (AECOM).Materials and methods:Adult patients diagnosed with AECOM were screened and patients fulfilling the inclusion criteria were randomized to receive either Clarithromycin (500 mg) twice daily or co-amoxyclav (625 mg) thrice daily orally for 7 days. The primary outcome of this randomized, open-labeled, phase IV clinical trial was clinical success rate at day 14 visit and the secondary outcome was incidence of adverse events (AES). Fifty patients were enrolled : 25 in the Clarithromycin group and 25 in the co-amoxyclav group.Results :  The clinical success rates were 92.7 % in the Clarithromycin group versus 90.2% in the co-amoxyclav group. These rates are comparable, but no statistically significant difference was observed between the groups.Conclusion:The results of this randomized, open-labeled phase IV clinical trial showed that a 7-day course of Clarithromycin is therapeutically comparable to co-amoxyclav in terms of both clinical effectiveness and safety for the treatment of patients with AECOM

Clinico-demographic study of otitis media with effusion in different age groups

Background: Otitis Media with Effusion is mainly a disease of childhood. But it can also occur in adults. It can present with various symptoms like difficulty in hearing, blocked sensation in the ear, earache, tinnitus etc. Young children are often diagnosed late due to their inability to express hearing difficulty, and are often diagnosed accidentally. Appearance of the tympanic membrane can also be varying among patients. There may be retraction, dull appearance and change in colour, or reduced mobility. Fluid level or air bubble can also be present in the middle ear behind the tympanic membrane.Aim: To study the demographic profile of the patients diagnosed with OME and to determine the variations in the signs and symptoms of OME in different age groups.Method: This is an observational study. It was conducted on all the patients attending the OPD at a tertiary hospital, and diagnosed with OME over the course of one year. The diagnosis was made after proper history taking and clinical examination and with the aid of audiometry and tympanometry. An effort was made to map out the demographic profile of all the patients diagnosed with OME, and to study the variations in the signs and symptoms of OME across different age groups.Result:In the analysis of parameters it was found that statistically significant higher number of cases were children (< 10 years of age). Number of male was more than female in children but it was equal in adult. Significantly more number of children in the study had bilateral involvement, but in adolescent and adult there was no statistical difference between the incidence of bilateral and unilateral involvement. Difficulty in hearing and heaviness in ears were the two most common presenting symptoms with addition of tinnitus in adult group. Most common appearance of the tympanic membrane was dull in all the ages.Conclusion:In the present study it is evident that the Otitis media with media (OME) is much more common in pediatric population and has a little male preponderance, which corroborates the consensus of the word literature. The present study also corroborates the existing knowledge on some aspect the disease like presenting symptoms (difficulty in hearing and block sensation being the commonest) appearance of tympanic membrane or degree of hearing loss.An effort was made in the present study to compare some aspect of the disease among the patients of different age group.While corroborating most of the issues regarding OME with the existing literature, present study indicates some differences in presentation and diagnostic features in different age groups

Study of Prevalence of Obstructive Sleep Apnoea Syndrome in Patients With Primary Open-Angle Glaucoma in A Tertiary Care Hospital of West Bengal

This study was conducted to investigate the prevalence of obstructive sleep apnea (OSA) in diagnosed patients of POAG. We also investigated whether there is an association between severity of OSA and the incidence of glaucoma. Method: Forty-two consecutive primary open-angle glaucoma patients (24 females and 18 males) who attended the out-patient clinic of the Department of Ophthalmology between July 2016 and February 2018 were included in this study. All patients underwent polysomnographic examination. Results:The prevalence of obstructive sleep apnoea syndrome was 33.3% in patients with primary open-angle glaucoma; the severity of the condition was mild in 14.3% and moderate in 19.0% of the subjects. The age (P=0.047) and neck circumference (P=0.024) in patients with obstructive sleep apnoea syndrome were significantly greater than those without the syndrome. Triceps skinfold thickness in glaucomatous obstructive sleep apnoea syndrome patients reached near significance versus those without the syndrome (P=0.078). Snoring was observed in all glaucoma cases with obstructive sleep apnoea syndrome. The intra-ocular pressure of patients with primary open-angle glaucoma with obstructive sleep apnoea syndrome was significantly lower than those without obstructive sleep apnoea syndrome (P=0.006 and P=0.035 for the right and left eyes, respectively). Significant difference in the cup/disc ratio and visual acuity was observed, except visual field defect, between primary open-angle glaucoma patients with and without obstructive sleep apnoea syndrome.Conclusion: Our study showed that there is a significant prevalence of obstructive sleep apnoea syndrome in patients with primary open-angle glaucoma. Keywords: Obstructive Sleep Apnea (OSA); Primary Open Angle Glaucoma (POAG); Polysomnography (sleep study); Neck Circumference; Triceps Skinfold Thickness; Snoring; Intra-Ocular Pressure; Cup/Disc Ratio; Visual Acuity

Ophthalmoplegia associated with head and neck malignancies: a case series

Ophthalmoplegia is the paralysis or weakness of the eye muscles. It can affect one or more of the six muscles that hold the eye in place and control its movement. Total ophthalmoplegia refers to the paralysis of all the muscles in the eye. People affected by ophthalmoplegia with orbital apex involvement may have double or blurred vision. They may also experience an inability to position the eyes in sync. Some may also have a hard time moving both eyes in every direction, and many will have drooping of their eyelids. Causes of ophthalmoplegia along with orbital apex involvement can be multiple sclerosis, trauma infarction, brain injury, stroke, thyroid disease, infection, associated with sinonasal malignancy, nasopharyngeal carcinoma, invasive fungal infections needing surgical removal and brain tumours

A Complicated Case of Foreign Body Oesophagus in an Infant

Ingestion of foreign bodies is common primarily in children, psychiatric patients, alcoholics and elderly people who use dentures. Selivanov et al. reported that, in most cases of foreign body ingestion, the most common foreign bodies ingested were coins, bones, food debris, safety pins and razor blades. Rarity, technical difficulty in removing the foreign body, complications associated with the delay in diagnosis and treatment, migration of the foreign body extraluminally, site, shape and position of the sharp end of a safety pin makes this case  interesting and worth reporting. We are reporting a case of a one year child presenting to us with accidental ingestion of a safety pin. The case was difficult because the protected end of the safety pin was broken which made both the ends of the foreign body sharp. Also, the ends of safety pin were wide apart and pointing upwards