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Biomedical subjects

A J Mehta

Publications and source records attributed to A J Mehta.

At least 19 recordsLinked to original sources
PubMed2005

Airflow limitation and changes in pulmonary function among bleachery workers.

This study investigated whether chronic airflow limitation and rapid decline in pulmonary function were associated with peak exposures to ozone and other irritant gases in pulp mills. Bleachery workers potentially exposed to irritant gassings (n = 178) from three Swedish pulp mills, and a comparison group of workers not exposed to irritant gassings (n = 54) from two paper mills, were studied. Baseline surveys occurred in 1995-1996, with follow-up surveys in 1998-1999. Participants performed spirometry and answered questions regarding ozone, chlorine dioxide (ClO2), and sulphur dioxide (SO2) gassings. From regression models controlling for potential confounders, declines in both the forced expiratory volume in one second (FEV1) (-24 mL x yr(-1)) and the forced vital capacity (FVC) (-19 mL x yr(-1)) were associated with ClO2/SO2 gassings. At follow-up, the prevalence of chronic airflow limitation (i.e. FEV1/FVC less than the lower limit of normal) was elevated for participants with only pre-baseline ozone gassings and with both pre-baseline and interval ozone gassings, after controlling for potential confounders. These findings suggest that obstructive effects among bleachery workers are associated with ozone gassings, and that adverse effects on spirometry might also accompany chlorine dioxide/sulphur dioxide gassings. Peak exposures to irritant gases in pulp mills should be prevented.

Adult↗
PubMed2001

Mitotic Golgi is in a dynamic equilibrium between clustered and free vesicles independent of the ER.

Golgi inheritance during cell division involves Golgi disassembly but it remains unclear whether the breakdown product is dispersed vesicles, clusters of vesicles or a fused ER/Golgi network. Evidence against the fused ER/Golgi hypothesis was previously obtained from subcellular fractionation studies, but left concerns about the means used to obtain and disrupt mitotic cells. Here, we performed velocity gradient analysis on otherwise untreated cells shaken from plates 9 h after release from an S-phase block. In addition, we used digitonin and freeze/thaw permeabilization as alternatives to mechanical homogenization. Under each of these conditions, approximately 75% of the Golgi was recovered in a population of small vesicles that lacked detectable ER. We also used multilabel fluorescent microscopy with optical sectioning by deconvolution to compare the 3D metaphase staining pattern of endogenous Golgi and ER markers. Although both ER and Golgi staining were primarily diffuse, only the ER was excluded from the mitotic spindle region. Surprisingly, only 2% of the Golgi fluorescence was present as resolvable structures previously characterized as vesicle clusters. These were not present in the ER pattern. Significantly, a portion of the diffuse Golgi fluorescence, presumably representing dispersed 60-nm vesicles, underwent an apparent rapid aggregation with the larger Golgi structures upon treatments that impaired microtubule integrity. Therefore, mitotic Golgi appears to be in a dynamic equilibrium between clustered and free vesicles, and accurate partitioning may be facilitated by microtubule-based motors acting on the clusters to insure random and uniform distribution of the vesicles.

Cell Fractionation↗
PubMed1996

Gastro-oesophageal reflux in patients with coronary artery disease: how common is it and does it matter?

OBJECTIVE: To investigate the influence of spontaneous gastro-oesophageal reflux (GOR) on symptoms and cardiac ischaemia in patients with coronary artery disease. DESIGN: Simultaneous 24-h ambulatory oesophageal pH, 7-lead electrocardiographic (ECG) monitoring and symptom diary in patients taking their usual anti-anginal medication. SETTING: Regional cardiothoracic unit and gastroenterology unit of a teaching hospital. SUBJECTS: Twenty-four patients (20 males, 4 females, mean age 59 years) with post-myocardial infarction angina and angiographically proven coronary artery disease. MAIN OUTCOME MEASURES: Quantitation of acid gastro-oesophageal reflux (% total time pH < 4, number of reflux episodes, duration of reflux episodes), identification of ST segment elevation or depression of 1 mm or more on 24-h ECG recording and occurrence of chest pain ("heartburn' or "angina') within 5 min of GOR or ischaemic ST segment shift. RESULTS: There were 568 episodes of GOR, 28 of which were symptomatic. Abnormal GOR (% total time pH < 4 greater than 7%) occurred in 9 (38%) of the patients; all reflux parameters were increased in nitrate users compared to non-users (P < 0.05). Ischaemic ST-segment shift was seen on 113 occasions. Of a total of 41 chest pain episodes, 20 were related to GOR ("angina' with 8, "heartburn' with 12), while 8 coincided with both GOR and ST depression together ("angina' in 5, "heartburn' in 3). In addition to these eight episodes, coincidence of ST depression with GOR occurred on another nine occasions (all asymptomatic). CONCLUSION: GOR is common in patients with coronary artery disease and may be increased by drug therapy; GOR may occasionally be associated with myocardial ischaemia, but this is uncommonly symptomatic; GOR-induced pain is sometimes mistaken for angina. These effects were uncommon overall, but frequent in a few individuals and should be considered in the evaluation of patients with persistent chest pain despite seemingly adequate antianginal treatment.

Aged↗
PubMed1995

Sensitization to painful distention and abnormal sensory perception in the esophagus.

BACKGROUND/AIMS: The mechanism of abnormal esophageal sensory perception in patients with unexplained chest pain is unknown. The aim of this study was to test the following two hypotheses: (1) similar to cutaneous nociceptors, esophageal stretch receptors can be sensitized by a noxious chemical stimulus, and (2) patients with esophageal chest pain have sensitized receptors. METHODS: Twenty-five patients with noncardiac chest pain underwent esophageal manometry, provocation tests, and 24-hour pH monitoring. Eleven patients had positive and 14 had negative results of esophageal provocation tests. Esophageal perception and pain thresholds for balloon stretch (in milliliters) and electrical stimulation (in milliamperes) were determined in patients and 7 healthy controls performed before and after randomized, double-blind esophageal perfusion with normal saline or 0.1N HCl. RESULTS: The basal balloon pain threshold was lower in patients with positive results of esophageal tests than in either those patients with negative results of esophageal tests or controls (P < 0.05). After acid perfusion, balloon perception and pain thresholds decreased in patients with negative results of esophageal tests (P < 0.05) and in controls (P < 0.05) but not in patients with positive results of esophageal tests. No change occurred after saline perfusion nor in electrical pain thresholds in any group after the perfusion of either fluid. CONCLUSIONS: In patients with negative results of esophageal tests and in controls, the pain threshold to balloon distention is lowered by acid. The lack of such effect in patients with positive results of esophageal tests implies that pain receptors may already be sensitized.

Acids↗
PubMed1993

Rehabilitation of fractures in the elderly.

Rehabilitation is the most important aspect of care after a fracture in an older person. Epidemiology, contributing factors, general principles of management are discussed in this article. Proper management requires knowledge of various mechanisms of injury, different forms of orthopedic treatments, interpretation of radiographs, and familiarity with available therapeutic modalities.

Activities of Daily Living↗
PubMed1990

Shoulder pain in hemiplegia. The role of exercise.

One of the causes for shoulder pain associated with hemiplegia is thought to be vigorous range of motion to the involved upper extremity. The objective of this study was to analyze the occurrence of pain in patients treated with one of the three exercise programs commonly used in the rehabilitation of hemiplegia: 1) range of motion by the therapist, 2) skate board and 3) overhead pulley. Of the 48 hemiplegic patients evaluated, 28 were assigned to one of the three exercise groups. Comparing the number of patients who developed pain in each group, there was a significant difference, with 8% of the patients in the range of motion by the therapist group, 12% of the patients in the skate board group and 62% of the patients in the overhead pulley group developing pain (chi 2 = 8.44) (P = 0.014). The three groups did not differ in the side of involvement (P = 0.57), extent of hemiplegia (P = 0.25) or presence of subluxation (P = 0.84). Use of overhead pulley has the highest risk of developing shoulder pain and should be avoided during rehabilitation of stroke patients.

Adult↗
PubMed1986

Peripheral nerve conduction studies and bulbocavernosus reflex in the investigation of impotence.

Patients with erectile dysfunction underwent sensory and motor conduction and bulbocavernosus reflex tests to determine the incidence of peripheral nerve involvement. Of a total of 111 patients, abnormal sensory conduction was found in 87 (78%), abnormal motor conduction in 56 (50%), and abnormal bulbocavernosus reflex in 40 (36%). Most of these patients had other medical problems. Objective evidence of peripheral nerve involvement helped in the management of these patients.

Adult↗
PubMed1985

Evaluation of impotence in older men.

Careful evaluation was carried out in 93 men older than 50 with erectile dysfunction. Their mean age was 61 years and the disorder had been present for a mean of 4.5 years. While 14 men (15%) had psychosocial factors that may have been pertinent, only 2 scored poorly on an Affect Balance Scale and 3 were receiving psychoactive medications. Results of nocturnal penile tumescence were abnormal in 91%. In 39% penile-brachial pressure indices were suggestive of pelvic vascular disease and in 9% were consistent with a pelvic "steal syndrome." Pelvic or peripheral nerve conduction disorders were also commonly seen in 54%. Endocrinopathy may have contributed to the dysfunction in 35%. Twenty-one men had diabetes mellitus, two new cases of hypothyroidism were discovered and hypogonadism was diagnosed definitely in four and considered likely in five others. Coexisting medical conditions were found in more than 90% of the men, especially hypertension, use of antihypertensive medications and atherosclerotic disease. Previous prostatectomies (19%) and vasectomies (30%) were common in the surgical histories. Given the wide range of disorders uncovered in older men complaining of impotence, diagnostic study of potential causes may lead to a more rational approach for the evaluation and management of these men.

Aged↗
PubMed1976

Orbicularis oculi reflex in brain death.

The early and late components of the orbicularis oculi reflex were absent bilaterally in three patients who fulfilled the clinical and electroencephalographic criteria of brain death. A response to peripheral facial nerve stimulation was obtained in all. These preliminary observations suggest that the study of the orbicularis oculi reflex is a simple, objective, bedside neurophysiological test of brain stem function, complementing the electroencephalogram in the diagnosis of brain death.

Adolescent↗