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Biomedical subjects

M Mehta

Publications and source records attributed to M Mehta.

At least 37 records · Page 2Linked to original sources
PubMed1999

Evaluation of CSF-adenosine deaminase activity in tubercular meningitis.

Sixty patients of inflammatory brain disease were diagnosed and classified according to clinico-investigational criteria by Ahuja et al into tuberculous meningitis group (36 patients) and non-tuberculous meningitis group (24 patients). Tuberculous meningitis (TBM) patients were classified as probable (9 patients) and possible (27 patients) TBM. Non-TBM group comprised of pyogenic meningitis (8.3%), viral encephalitis (23.3%), cerebral malaria (5%) and enteric encephalopathy (3.3%). Cerebrospinal fluid-adenosine deaminase (CSF-ADA) activities were measured in both TBM and non-TBM groups. Mean CSF-ADA levels in TBM patients was 9.61 +/- 4.10 IU/L and was significantly elevated as compared to viral encephalitis and enteric encephalopathy cases; but difference was insignificant in comparison to pyogenic meningitis (7.92 +/- 0.95 IU/L) and cerebral malaria. Using 8 IU/L as cut off value for diagnosis of TBM a sensitivity of 44% and specificity of 75% was observed.

Adenosine Deaminase↗
PubMed1998

MR imaging of symptomatic osteochondromas with pathological correlation.

OBJECTIVE: To demonstrate the value of MR imaging in the diagnosis and differentiation of the various symptomatic complications of osteochondromas, providing pathological correlation with emphasis on the usefulness of MR imaging as a single imaging modality in these patients. DESIGN: We retrospectively reviewed all MR examinations of clinically symptomatic osteochondromas (30 patients) performed at our institution between March 1990 and October 1997. PATIENTS: Thirty patients had clinically symptomatic osteochondromas during the study period. Twenty patients were male and 10 were female. There were five cases of multiple osteochondromatosis. Pathological correlation was available in 24 patients. RESULTS AND CONCLUSION: Symptomatic complications included fracture (7%), osseous deformity limiting range of motion (23%), vascular injury (7%), neurological compromise (10%), bursa formation (27%) and malignant transformation (27%). MR imaging was able to diagnose or suggest the etiology for the clinical symptomatology in all cases, demonstrating that it is an ideal imaging modality in the diagnostic evaluation of symptomatic complications of osteochondromas and often avoids the need for further imaging.

Adolescent↗
PubMed1997

A cost-effectiveness and cost-utility analysis of radiosurgery vs. resection for single-brain metastases.

PURPOSE: The median survival of well-selected patients with single-brain metastases treated with whole-brain irradiation and resection or radiosurgery is comparable, although a randomized trial of these two modalities has not been performed. In this era of cost containment, it is imperative that health-care professionals make fiscally prudent decisions. The present environment necessitates a critical appraisal of apparently equi-efficacious therapeutic modalities, and it is within this context that we present a comparison of the actual costs of resection and radiosurgery for brain metastases. METHODS AND MATERIALS: Survival and quality of life outcome data for radiation alone or with surgery were obtained from two randomized trials, and radiosurgical results were obtained from a multiinstitutional analysis that specifically evaluated patients meeting surgical criteria. Only linear accelerator radiosurgery data were considered. Cost analysis was performed from a societal view point, and the following parameters were evaluated: actual cost, cost ratios, cost effectiveness, incremental cost effectiveness, cost utility, incremental cost utility, and national cost burden. The computerized billing records for all patients undergoing resection or radiosurgery for single-brain metastases from January 1989 to July 1994 were reviewed. A total of 46 resections and 135 radiosurgery procedures were performed. During the same time period, 454 patients underwent whole-brain radiation alone. An analysis of the entire bill was performed for each procedure, and each itemized cost was assigned a proportionate figure. The relative cost ratios of resection and radiosurgery were compared using the Wilcoxon rank sum test. Cost effectiveness of each modality, defined as the cost per year of median survival, was evaluated. Incremental cost effectiveness, defined as the additional cost per year of incremental gain in median survival, compared to the next least expensive modality, was also determined. To calculate the societal or national impact of these practices, the proportion of patients potentially eligible for aggressive management was estimated and the financial impact was determined using various utilization ratios for radiosurgery and surgery. RESULTS: Both resection and radiosurgery yielded superior survival and functional independence, compared to whole brain radiotherapy alone, with minor differences in outcome between the two modalities; resection resulted in a 1.8-fold increase in cost, compared to radiosurgery. The latter modality yielded superior cost outcomes on all measures, even when a sensitivity analysis of up to 50% was performed. A reversal estimate indicated that in order for surgery to yield equal cost effectiveness, its cost would have to decrease by 48% or median survival would have to improve by 108%. The average cost per week of survival was $310 for radiotherapy, $524 for resection plus radiation, and $270 for radiosurgery plus radiation. CONCLUSIONS: For selected patients, aggressive strategies such as resection or radiosurgery are warranted, as they result in improved median survival and functional independence. Radiosurgery appears to be the more cost-effective procedure.

Brain Neoplasms↗
PubMed1997

Central neurocytoma: a clinical study of response to chemotherapy.

We report a case of central neurocytoma treated, after an initial partial resection, by chemotherapy, comprising etoposide, ifosfamide and carboplatin. A response was obtained and further treatment was given with surgery and radiotherapy. There have been no previous reports of response to chemotherapy in this relatively rare tumour.

Adolescent↗
PubMed1997

The effect of anti-prolactin antibody on in vitro synthesis of a pregnancy-associated rat uterine glycoprotein.

Experiments were conducted to study the hormonal (estrogen [E2], progesterone [P4] and prolactin [PRL]), regulation of synthesis of a pregnancy-associated glycoprotein (named Uterine Agglutinin or UA) in the Day 4 post coital (p.c.) rat uterus with antibody administration and immunohistochemistry. Of the antibodies used, it was shown that anti-PRL antibody was the most effective in reducing in vitro UA synthesis. The results suggested that in vitro UA synthesis could be correlated to serum PRL levels as analyzed by radio-immunoassay. Binding studies revealed that PRL bound specifically to the stromal cells of the rat uterus where UA is produced and localized.

Agglutinins↗
PubMed1997

Spinal cord motoneuron excitability during isoflurane and nitrous oxide anesthesia.

BACKGROUND: Recent evidence suggests that the spinal cord is an important site of anesthesia that is necessary for surgical immobility, but the specific effect of anesthetics within the spinal cord is unclear. This study assessed the effect of isoflurane and nitrous oxide on spinal motoneuron excitability by monitoring the H-reflex and the F wave. METHODS: Eight adult patients, categorized as American Society of Anesthesiologists physical status 1 or 2, who were undergoing elective orthopaedic surgery were anesthetized with 0.6, 0.8, 1.0, and 1.2 times the estimated minimum alveolar concentration (MAC) of isoflurane. Nitrous oxide was added in graded concentrations of 30%, 50%, and 70%, whereas the isoflurane concentration was decreased to maintain a total MAC of 1. The H-reflex of the soleus muscle and the F wave of the abductor hallucis muscle were measured before anesthesia and 15 min after each change of anesthetic concentration. Four or more trials of the H-reflex and 18 trials of the F wave were recorded at each concentration of anesthesia. The effect of the anesthetics on the H-reflex and F wave was analyzed using. Dunnett's test. RESULTS: H-reflex amplitude was decreased to 48.4 +/- 18.6% of preanesthesia level at 0.6 MAC isoflurane and to 33.8 +/- 19.1% when isoflurane concentration increased from 0.6 MAC to 1.2 MAC. F wave amplitude and persistence decreased to 52.2 +/- 33.6% and 44.4 +/- 26% of baseline at 0.6 MAC isoflurane, and to 33.8 +/- 26% and 21.7 +/- 22.8% at 1.2 MAC isoflurane. Isoflurane plus nitrous oxide (total 1 MAC) decreased H-reflex amplitude to 30.4-33.3% and decreased F wave persistence to 42.8-56.3% of baseline. CONCLUSIONS: Both isoflurane alone and isoflurane plus nitrous oxide decrease H-reflex and F-wave amplitude and F-wave persistence. These effects suggest that isoflurane and nitrous oxide decrease motoneuronal excitability in the human spinal cord. This may play an important role in producing surgical immobility.

Adult↗
PubMed1996

Behavior of the H-reflex in humans following mechanical perturbation or injury to rostral spinal cord.

In humans H-reflexes are suppressed during early spinal shock. In animals rostral cord injury results in loss of segmental reflexes within seconds. If H-reflexes persist under general anesthesia, can they be used to monitor the integrity of the rostral cord? In part I of this study, we recorded H-reflexes intraoperatively in 25 patients to elucidate general anesthesia effect. In 23 subjects, H-reflexes were consistently elicited, and within +/- 13% of the normalized group mean amplitude. In part II, we recorded H-reflexes in 31 patients during spinal cord surgery to elucidate H-reflex behavior immediately following rostral spinal cord injury. In 6, abrupt suppression of the H-reflex coincided with cord injury. In 4 of 6, suppression was transient and less than 50% of baseline; none of these patients developed neurological deficits. In 2, suppression exceeded 90% and persisted throughout surgery; both patients developed profound deficits. We conclude that (1) the H-reflex can be consistently elicited under general anesthesia in most patients, (2) rostral cord injury rapidly suppresses the H-reflex, and (3) the degree and duration of H-reflex suppression reflects the severity of the injury.

Adolescent↗
PubMed1996

FosB in the suprachiasmatic nucleus of the Syrian and Siberian hamster.

The suprachiasmatic nucleus (SCN) generates circadian rhythms of behavior and hormone secretion in mammals, and integrates responses to light and nonphotic stimuli to synchronize such rhythms with the external environment. Previous studies have demonstrated a close association between the induction of the immediate early gene (IEG) c-fos in the SCN by light and phase shifts of circadian rhythms induced by light, but nonphotic stimuli (e.g., arousal), which also cause phase shifts, do not increase c-fos expression in the SCN. Because c-fos is now known to be a member of a large family of IEGs which can regulate transcription and thus cellular function, the aim of the current study was to determine whether induction of another member of this immediate early gene family, fosB, is associated with photic and nonphotic phase shifts. An antiserum that recognizes a unique peptide sequence derived from FosB was produced so that the expression of fosB could be investigated in cells within the SCN by immunocytochemical detection of its protein product. The regional distribution of FosB-immunoreactive (ir) cells in the SCN of Syrian and Siberian hamsters was broadly similar to that for c-Fos-ir cells. However, whereas c-fos expression in the SCN was constitutively low, but could be massively induced by light at particular circadian phases, FosB-ir cells were present at all circadian phases studied, irrespective of photic stimulation, and light only produced marginal increases in the number of FosB-ir cells compared with nonstimulated controls. Moreover, blockade of glutamatergic neurotransmission by pretreatment of hamsters with the NMDA receptor antagonist MK801 significantly reduced photic induction of c-Fos-ir cells, but did not influence the number of FosB-ir cells in the SCN. Finally, an arousing nonphotic stimulus known to cause phase advances in wheel-running behavior in Syrian hamsters did not alter significantly the number of FosB-ir cells in the SCN. These observations indicate that light and nonphotic stimuli are not potent regulators of fosB expression in the SCN. However, because fosB and c-fos can be present in the SCN at the same time after a light pulse, these studies indicate the potential for interactions with each other and with members of the Jun family in the regulation of the circadian timing system.

Animals↗
PubMed1996

Neuroticism in a family practice population in India.

This study was conducted to assess the prevalence of neuroticism and its correlation with the various sociodemographic factors and presenting complaints among patients attending a family practice outpatient clinic. One hundred and forty two consecutive patients attending the outpatient clinic were administered PGI Health Questionnaire N2. Higher incidence of neuroticism was observed in middle age group population, in females (especially housewives), unskilled workers, patients with lower educational status and those belonging to small and nuclear families. A significant number of such patients had presented with vague symptoms, were visiting the clinics frequently and had associated chronic diseases. The results suggest that patients visiting the family practice clinics frequently with multiple somatic complaints with no suggested organic basis should undergo an in-depth psychiatric evaluation.

Adult↗
PubMed1996

Computed tomography appearance of idiopathic aneurysm of the azygos vein.

True idiopathic aneurysm of the azygos vein is a rarely described abnormality. The authors present a case of this anomaly in a 70-year-old woman with a history of rectal carcinoma. The aneurysm was found incidentally on computed tomography, performed to characterize the appearance of a lung nodule. The aneurysm decompressed when the patient was upright. The effects of respiratory and postural manoeuvres on the lesion are discussed and the computed tomography appearance is described.

Adenocarcinoma↗