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Biomedical subjects

V Sharma

Publications and source records attributed to V Sharma.

At least 37 records · Page 2Linked to original sources

Three-dimensional photonic devices fabricated in glass by use of a femtosecond laser oscillator.

Three-dimensional photonic waveguide devices are fabricated in glass by use of femtosecond pulses from an extended-cavity laser oscillator. Three-dimensional devices, including a symmetric three-waveguide directional coupler and a three-dimensional microring resonator, are fabricated and tested. Waveguides can be fabricated at depths of approximately 1 mm inside a glass substrate, thus demonstrating the capability of achieving dramatic increases in device density. These results demonstrate the potential to fabricate new classes of devices that are not possible in two dimensions.

Journal Article↗

Injectable midazolam as oral premedicant in pediatric neurosurgery.

In a randomized, double blind, placebo controlled study; the acceptability, efficacy and safety of injectable midazolam as oral premedicant in children was evaluated. One hundred children (ASA 1,2) aged 6 months to 6 years, undergoing elective neurosurgical operations, like meningomyelocele, meningo-encephalocele, ventriculo peritoneal and other shunts and craniotomies for tumour decompression etc., were included in the study. The patients were randomly assigned to one of four groups (A, B, C, D) receiving respectively saline or 0.50, 0.75 and 1.0 mg/kg midazolam in honey, 45 min before separation from parents. All received identical general anesthesia (GA). Age, sex, weight, heart rate, blood pressure, respiratory rate, saturation (SaO2), reaction to parent's separation, sedation score and duration of anesthesia, recovery conditions and side effects were noted. We found no difference in age, sex, weight, patient acceptability vomiting after ingestion and duration of anesthesia between groups. Even though many children resisted the placement of premedicant in the mouth, only three children spat it out and none vomited after swallowing. The reaction to separation from parents was better after midazolam premedication. However, on reaching the operating room, 24% children (placebo-60%) were found anxious after 0.50 mg/kg, but 12% were deeply sedated after a dose of 1.0 mg/kg. Recovery was similar in groups A, B and C except that more (48%) patients were anxious in group A. Recovery, however was delayed in 16% patients of group D. Though, fewer complications were reported during recovery after midazolam than placebo premedication, they were minimal in the 0.75 mg/kg group. We concluded that giving injectable midazolam orally as premedication in pediatric age group scheduled for neurosurgical operations is acceptable, effective and safe in 0.75 mg/kg dose. While 0.50 mg/kg is less effective, 1.0 mg/kg does not offer any additional benefit over 0.75 mg/kg but does delay recovery and may compromise safety.

Age Factors↗

Invasive aspergillosis involving multiple paranasal sinuses--a case report.

A case of invasive multiple paranasal sinus aspergillosis with bony involvement is reported. A young immunocompetent lady presented with bilateral nasal obstruction due to polyps. Radiologically and histopathologically a fungal cause was kept a possibility, and the diagnosis of Aspegillus fumigatus was established by demonstration of acute angle branching septate hyphae on direct wet mount and repeated isolation in culture. Patient responded favourably to surgical excision of polyps and oral itraconazole post operatively.

Adult↗

Self-administered hand symptom diagram for carpal tunnel syndrome diagnosis.

In a prospective case series in Singapore we studied whether a hand symptom diagram can be used to predict carpal tunnel syndrome as defined by standardized clinical and neurophysiological protocol. Forty patients (mean age, 48 years, range 18-76) with carpal tunnel syndrome found it difficult to complete the hand diagram, and only four patients were able to mark it helpfully. There was no relation between drawings, clinical and neurophysiological parameters. A self-administered hand symptoms diagram is not useful for supporting a diagnosis of carpal tunnel syndrome amongst Singaporeans. Cultural factors may significantly influence subjective assessment scales such as the self-administered hand symptom diagram, which has been found effective in North American populations.

Adolescent↗

Identification of serine protease as a major allergen of Curvularia lunata.

BACKGROUND: Several proteins from Curvularia lunata have been identified as important fungal allergens. It will be worthwhile to study the functional aspects of these allergens. The present study aimed at purifying a major allergen and determining its biological function. METHODS: Concanavalin A and Superdex 75 were used to purify Cur l 1 major allergen from C. lunata. Cur l 1 activity was determined qualitatively and quantitatively. Serine protease inhibitors and specific substrate was used to determine the biological function of the protein. RESULTS: Concanavalin A-bound fraction showed five allergenic proteins, which on Superdex G-75 purification gave a homogenous Cur l 1 protein. Cur l 1 showed IgE reactivity with 80% of the C. lunata hypersensitive patient's sera indicating it to be a major allergen. It showed protease activity on different substrates. Cur l 1's amino terminal sequence, GLTQKSAPWGLGADTIVAVELDSY, showed homology with the alkaline serine protease precursor. Phenylmethylsulfonylfluoride, pefabloc, aprotinin and leupeptin inhibited 70-80% enzymatic activity of Cur l 1 and no inhibition was observed with ethylenediaminetetraacetic acid (EDTA). A dose-dependent hydrolysis of Nalpha-benzoyl-l-arginine ethyl ester-hydrochloride, a specific serine protease substrate was obtained with Cur l 1. CONCLUSION: A major glycoprotein allergen Cur l 1 was purified to homogeneity from C. lunata. Amino terminal sequence and biochemical assays identified it as a serine protease.

Allergens↗

Constitutive expression of interleukin-18 and interleukin-18 receptor mRNA in tumour derived human B-cell lines.

Interleukin-18 (IL-18) is a pro-inflammatory cytokine involved in the Th1 immune response and expressed by a variety of cell types. IL-18 is a member of the IL-1 family and plays an important role in autoimmune diseases and inflammation. Using reverse transcriptase-polymerase chain reaction (RT-PCR) mRNA expression of IL-18, IL-18 receptor alpha (IL-18R alpha), and beta (IL-18R beta) were studied in tumour derived human B-cell lines. Furthermore, we investigated IL-18 protein secretion by using enzyme linked immunosorbent assay (ELISA). The results, as presented in this report, suggest that IL-18, IL-18R alpha, and IL-18R beta mRNA are constitutively and ubiquitously expressed in human B-cell lines, but secretion of the functional protein does not occur. We therefore speculate that IL-18 possibly affects B-cells through paracrine actions.

B-Lymphocytes↗

Double extradural hematoma: an analysis of 46 cases.

AIMS: The authors analyze epidemiology, location, clinical profile and outcome of double extradural hematoma (EDH) or EDH at more than one site. DESIGN: A retrospective clinical study. MATERIALS AND METHODS: 46 cases of double EDH were studied. All the cases were evaluated for their mode of injury, clinical presentation, level of sensorium at the time of injury, CT scan finding and outcome after surgery, and were compared with single EDH cases. RESULTS: Out of 1025 cases 46 cases had 'double' EDH. There was bilateral EDH in 39 cases; multiple EDH in 3 cases and ipsilateral double EDH was present in 4 cases. The most common site was frontal (70%). The majority of the patients (80.3%) were in altered sensorium from the time of injury, similar situation was seen in 52.2% of cases with single EDH. The number of patients having a low GCS score was higher when first examined in the double EDH group and the mortality rate was 34.8% as compared to 9% in the single EDH group. CONCLUSION: Majority of the double EDH cases presented with a low GCS and there was a relatively quick neurological deterioration in these cases.

Adolescent↗

Role of sleep loss in the causation of puerperal psychosis.

Puerperal psychosis is a rare but serious psychiatric disorder following delivery. Although controversy continues to surround its nosological status, puerperal psychosis is generally considered a mood episode with psychotic features occurring in the context of bipolar disorder or schizoaffective disorder. Due to the close temporal association with childbirth, the etiological role of gonadal steroids, particularly estrogen, has been considered. Familial factors have also been implicated in the triggering of episodes of puerperal psychosis. Sleep deprivation arising from an array of diverse factors is a common occurrence surrounding parturition. The author suggests that sleep loss plays a pivotal role in the causation of puerperal psychosis. Clinical implications of this hypothesis are discussed. Studies on the aetiology and pathogenesis of puerperal psychosis are urgently needed not only for prevention and better treatment strategies of puerperal psychosis but also for understanding the biological underpinnings of bipolar disorder.

Female↗

Use of irradiated amnion as a biological dressing in the treatment of radiation induced ulcers.

The management of moist skin desquamation (ulceration) following radiation therapy has been a concern since the inception of this therapy. The treatment of skin reactions focuses on promoting healing, improving patient comfort preventing infection and decreasing trauma to the area. Various dressings like topical preparations, hydrocolloid and gentian violet 1 % dressing have been used for its treatment. We present our experience with the use of amnion as a biological dressing in patients with radiation induced ulceration following pelvic radiation using megavoltage beam. The preliminary experience with treatment in 14 patients proved to be cost effective due to a shorter duration of ulcer healing (median of 7 days), fewer dressing changes (median of 4 dressings) and diminished use of analgesics.

Journal Article↗

Current perspectives on cytokines for anti-retroviral therapy in AIDS related B-cell lymphomas.

The development of high-grade B-cell lymphoma in Acquired Immunodeficiency Syndrome (AIDS) patients is a relatively late manifestation induced by Human Immunodeficiency Virus-1 (HIV) infection and is considered to be an AIDS-defining condition. Multiple, ongoing molecular and cytogenetic aberrations appear necessary for the development of AIDS-related lymphoma. Studying a panel of human B-cell lines derived from patients with Burkitt's lymphoma (BL) and AIDS-associated Burkitt's lymphoma (AIDS-BL) we had described constitutive expression and secretion of large amounts of Interleukin-16 (IL-16), Macrophage Inflammatory Protein-1alpha (MIP-1alpha), Macrophage Inflammatory Protein-1beta (MIP-1beta), Interleukin-12 (IL-12), Interleukin-10 (IL-10), and Interleukin-7 (IL-7). Some of these cytokines like IL-16, MIP-1beta, MIP-1alpha and Regulated upon activation normal T expressed and secreted (RANTES) are shown to have inhibitory effect on HIV replication. Interestingly, we identified a novel transcription factor family, Macrophage Inflammatory Protein-1alpha Nuclear Protein (MNP), which is suggested as a potential target for anti-retroviral therapy based on the implication of its role and involvement as a key regulator of MIP-1alpha. It is apparent, that HIV induces the production of a cascade of cytokines and cytokine receptors. Some of these molecules serve to increase the infection and replication of HIV per se, and some others serve to induce a state of B-cell growth, activation, and differentiation. This review attempts to delineate the complex mechanisms of viral, B-cell, oncogene, cytokine/cytokine receptor and transcription factor interactions that are involved in AIDS associated lymphomagenesis. Unfolding the relationship between cytokines and the underlying mechanisms of the disease will not only help in understanding the pathophysiology but also will facilitate focusing on the development of new diagnostic and therapeutic strategies.

Acquired Immunodeficiency Syndrome↗

Prodrugs and mutual prodrugs: synthesis of some new pyrazolone and oxadiazole analogues of a few non-steroidal anti-inflammatory drugs.

Naproxen, probenecid, diclofenac, ibuprofen and indomethacin were converted to hydrazide derivatives via their methyl ester by reacting with hydrazine hydrate, which were further condensed with beta-keto esters to get the pyrazolone derivatives. The hydrazide derivatives of probenecid and diclofenac were also reacted with biphenyl acetic acid while naproxen hydrazide was reacted with p-chloro benzoic acid besides biphenyl acetic acid to synthesize their oxadiazole analogues. Some selected members of the compounds prepared were screened for their anti-inflammatory and analgesic activity.

Analgesics↗

Disability in children from different ethnic populations.

We report on the prevalence of severe neurodisability in children in the Southern Derbyshire Health Authority from different ethnic groups. Information was obtained from the health records of children at the Child Development Centre (CDC), and analysed according to ethnic group. There were 53 in the Pakistani group, 20 in the Indian group and 764 in a mixed group, of which 95% were of European origin. It was estimated that all children with severe disability in the area of the Health Authority had notes at the CDC, except for 10% of the mixed group living on the periphery. The numbers of children with different disabling conditions were recorded, together with a measure of the level of individual disability; the 'Disability Scores'. We also noted if the condition was genetic or chromosomal in origin. Pakistani children showed a higher prevalence than the other groups of severe learning disorder, severe and profound hearing loss and severe visual problems. They also had a slightly increased prevalence of autism and cerebral palsy. Conversely, they showed a lower prevalence of language disorder. Disability scores for Pakistani children attending the CDC were higher than for other groups. Genetic disease causing disability was 10 times more common in the Pakistani children than other ethnic groups. Disability is more common in Pakistani children probably as a result of the cultural practice of consanguineous marriages. This community needs special help for disabled children, and their families, for general support and appropriate genetic counselling.

Adolescent↗

Folliculogenesis in buffalo (Bubalus bubalis): a review.

The urgent need for improving the reproductive performance of buffalo necessitates a better understanding of the mechanisms controlling ovarian follicular growth and development. Attention needs to be focused on improving superovulation responses and conception rates, and reducing the variability in ovulation rate and embryo loss. Application of ultrasonic imaging has revealed that follicular turnover during an unstimulated oestrous cycle occurs in waves, with each wave involving synchronous development of a group of follicles, one dominant and several subordinate follicles. There is a predominance of two waves with the first wave beginning around Day 0 (day of ovulation) and the second wave around Day 9 or 10. Primary reasons for a lower superovulation response in buffalo compared with that in cattle is a lower number of primordial and antral follicles, a slower shift from small to large follicles during superovulation, a higher incidence of deep atresia and inability of several large follicles to ovulate, especially when superovulation is induced by equine chorionic gonadotrophin treatment. There is near complete lack of information in Bubalus bubalis on the factors controlling the selection of the dominant follicle, the period of functional dominance and the effects of environmental factors, such as climate and nutrition, on follicular dynamics.

Animals↗

Embryo quality and IVF treatment outcomes may correlate with different sperm comet assay parameters.

BACKGROUND: Standard semen parameters have proven poor at predicting the outcomes of IVF treatment cycles. As recent studies suggest that the male genome may play an important role in early embryogenesis, this study attempts to correlate the level of sperm DNA damage in fresh semen and prepared sperm with the outcomes of conventional IVF treatment cycles. METHODS: Forty patients embarking on IVF treatment were recruited into this prospective observational study. Both fresh semen and PureSperm-prepared sperm were processed using a modified comet assay 3-6 months prior to the patients' IVF treatment cycles. Comet head DNA (mean and integrated head density) and tail DNA parameters (length and moment) were measured separately. RESULTS: Significant correlations between total sperm concentration and between comet length, moment, mean head density with embryo quality were detected in fresh semen and prepared sperm. Surprisingly, no significant correlations between head and tail parameters were detected. CONCLUSIONS: Comet head and tail DNA parameters appear to be potentially useful as predictors of embryo quality and IVF outcomes, especially in couples with unexplained subfertility. The lack of correlation between head and tail parameters may be due to a different mechanism of DNA damage within these two compartments.

Adult↗

Preliminary assessment of intrahemispheric QEEG measures in bipolar mood disorders.

OBJECTIVE: This study assessed the quantitative electroenchephalographic (QEEG) absolute power and coherence differences between a group of patients with bipolar I mood disorder (BMD I) and a group of patients with schizophrenia. We also examined the correlation between QEEG measures and family history of BMD. METHOD: Using the National Institutes of Mental Health (NIMH) Global Rating Scale, we rated 18 adult inpatients with a DSM-III-R diagnosis of BMD I for the severity of the current episode. We also collected data on the family history of the illness. This group was then matched for age, sex, and handedness with an equal number of inpatients with a DSM-III-R diagnosis of schizophrenia. QEEG absolute power and coherence was calculated for the alpha bandwidth (8.0 to 12.0 Hz), assessed at 18 pairs of electrodes in both hemispheres during resting, eyes-closed condition in all the patients. RESULTS: The patients with schizophrenia showed significantly higher coherence (P = 0.047) at 6 pairs of electrodes on the right side. The group with BMD showed significantly higher power (P = 0.042) at 2 pairs of electrodes on the right side. Correlational analysis showed that QEEG measures were significantly correlated (P = 0.01) with positive family history of BMD. CONCLUSION: These findings suggest that the patients with BMD are more disorganized in the right anterior hemisphere and that there is a significant positive correlation between the QEEG measures and the presence of family history of BMD. Further studies in a larger sample are required to confirm these preliminary findings.

Adult↗