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Biomedical subjects

A Bhattacharya

Publications and source records attributed to A Bhattacharya.

At least 127 records · Page 7Linked to original sources
PubMed1996

Postural stability assessment in sewer workers.

In this study, postural stability was measured with a microcomputer-based force platform as an indirect assessment of central nervous system effect in 28 sewer workers (age range 23.4 to 64.5 years, standard deviation of 8.7 years). All workers performed four 30-second postural sway tests. The organic-solvent exposure was measured by a photo-ionization detector. The photo-ionization detector was calibrated to measure volatile organic solvents in total benzene equivalence, and concentrations were measured in various parts of the plant. The mean exposure was .32 parts per million (ppm) benzene equivalent (range of .02 to .95 ppm, standard deviation .19 ppm). Based on a covariate adjusted linear multiple-regression model, a statistically significant (p < .05) positive correlation was demonstrated between postural sway and organic-solvent exposure. These workers also had increased postural sway compared with a nonexposed population. The statistically significant correlation between postural sway determinations and organic-solvent exposure was surprising given the very low exposures measured. It is possible that the organic-solvent exposure might not be the causative agent, but rather that the solvents themselves correlate with some other causative exposure, ie, total volatile organics as implicated in the cause of sick-building syndrome.

Adult↗
PubMed1996

Replication initiates at multiple dispersed sites in the ribosomal DNA plasmid of the protozoan parasite Entamoeba histolytica.

In the protozoan parasite Entamoeba histolytica (which causes amoebiasis in humans), the rRNA genes (rDNA) in the nucleus are carried on an extrachromosomal circular plasmid. For strain HM-1:IMSS, the size of the rDNA plasmid is 24.5 kb, and 200 copies per genome are present. Each circle contains two rRNA transcription units as inverted repeats separated by upstream and downstream spacers. We have studied the replication of this molecule by neutral/neutral two-dimensional gel electrophoresis and by electron microscopy. All restriction fragments analyzed by two-dimensional gel electrophoresis gave signals corresponding to simple Y's and bubbles. This showed that replication initiated in this plasmid at multiple, dispersed locations spread throughout the plasmid. On the basis of the intensity of the bubble arcs, initiations from the rRNA transcription units seemed to occur more frequently than those from intergenic spacers. Multiple, dispersed initiation sites were also seen in the rDNA plasmid of strain HK-9 when it was analyzed by two-dimensional gel electrophoresis. Electron microscopic visualization of replicating plasmid molecules in strain HM-1:IMISS showed multiple replication bubbles in the same molecule. The location of bubbles on the rDNA circle was mapped by digesting with PvuI or BsaHI, which linearize the molecule, and with SacII, which cuts the circle twice. The distance of the bubbles from one end of the molecule was measured by electron microscopy. The data corroborated those from two-dimensional gels and showed that replication bubbles were distributed throughout the molecule and that they appeared more frequently in rRNA transcription units. The same interpretation was drawn from electron microscopic analysis of the HK-9 plasmid. Direct demonstration of more than one bubble in the same molecule is clear evidence that replication of this plasmid initiates at multiple sites. Potential replication origins are distributed throughout the plasmid. Such a mechanism is not known to operate in any naturally occurring prokaryotic or eukaryotic plasmid.

Amebiasis↗
PubMed1996

Analgesia for acute musculoskeletal trauma: low-dose subcutaneous infusion of ketamine.

Low-dose ketamine by subcutaneous infusion (0.1 mg/kg/h) was compared in double-blind fashion with intermittent morphine (0.1 mg/kg intravenously, four-hourly) as analgesic regimen in 40 ASA-I adults after acute musculoskeletal trauma. Pain was assessed using visual analogue scales and sedation was graded on a four point rank drowsiness score. Objective cardiovascular and respiratory parameters and patient acceptability in terms of supplementary analgesia and early mobilization were also recorded. Pain relief was better with the ketamine infusion than with intermittent morphine (P < 0.001). Patients were more awake and alert with ketamine infusion as evidenced by the drowsiness score (P < 0.001). Peak expiratory flow rate improved significantly with the ketamine infusion (P < 0.05). None of the patients in ketamine group required supplementary analgesia (P < 0.001) and the patients could be easily mobilized for traction/splintage as compared with patients in the control group (P < 0.001). The incidence of nausea and vomiting in the morphine group was high (P < 0.01). The study shows that subcutaneous infusion of ketamine provides safe and effective analgesia in acute musculoskeletal trauma.

Adult↗
PubMed1996

Fine needle aspiration cytology of ophthalmic lesions.

Forty cases of ophthalmic lesions were subjected to fine needle aspiration cytology for pre-operative diagnosis which included retinoblastomas (5 cases), inflammatory and neoplastic lesions of the eyelid and lacrimal glands (29 cases) and extra-ocular orbital lesions (6 cases) inclusive of 3 cases of rhabdomyosarcomas. The lesions were distributed in both the eyes almost in equal proportions. Histological confirmation was obtained in 85% of cases; false positive in only one case with malignant neoplasm of the eyelid and false negative also in only one case with inflammatory pseudotumour which were, histologically, proved to be adenoma of tarsal gland and lymphocytic lymphoma respectively.

Biopsy, Needle↗
PubMed1996

Electroacupuncture, morphine and clonidine: a comparative study of analgesic effects.

This is a comparative study of the analgesic effects of the modified traditional method of analgesia, electroacupuncture (EA), a standard analgesic drug, morphine, a potential analgesic drug, clonidine and the combination of EA + morphine and EA + clonidine. In each case, the index of analgesia (IA) was determined by recording the tail flick latency (TFL) in 60 rats divided into 6 groups of 10 rats each. Group I rats served as control group while Group II-VI were subjected to EA for 20 min (at Zusanli and Kunlun points), morphine (5 mg/kg bw i.p.), clonidine (150 micrograms/kg bw i.p.), EA + morphine and EA + clonidine respectively. TFLs were recorded after the procedure and at 10 min intervals for 150 min or til the TFL returned to¿ the baseline. The IA, analyzed using the Kruskal-Wallis test and its significance determined by multiple comparison test (at 5% level), was found to be significantly different, at various time intervals, in the 6 groups studied.

Analgesics↗
PubMed1995

Structure and function of the HOX A1 human homeobox gene cDNA.

Homeobox genes code for transcription factors and are arranged in clusters, named A, B, C and D, found on four separate chromosomes in vertebrates. They contain a homeobox DNA sequence which codes for the homeodomain, a region of amino acids responsible for the DNA binding exhibited by these proteins. During embryonic development, the homeobox genes are both spatially and temporally regulated. In teratocarcinoma cell cultures, homeobox genes are regulated by retinoic acid (RA). The cDNAs from the first gene in the human HOX A cluster, HOX A1 (1.6), were cloned and the nucleotide sequence of a full-length cDNA was determined. It is highly homologous to its murine counterpart. Another HOX A1 cDNA was cloned, corresponding to an alternatively spliced form. In vitro translation of the full-length cDNA clone gave rise to a protein of 36 kDa. In PA-1 human teratocarcinoma cells HOX A1 is the earliest HOX A gene to be expressed after treatment with RA. To test whether HOX A1 could function as a early regulator of other HOX A cluster genes, we cotransfected into PA-1 human teratocarcinoma cells sense and antisense HOX A1 cDNAs expressed from an SV40 promoter with a 5.4-kb RA-sensitive HOX A4 (1.4) promoter-cat reporter. We found no effect of HOX A1 on the HOX A4 promoter. However, cotransfection of HOX A5 (1.3) was able to inhibit the HOX A4 promoter activity.

Alternative Splicing↗
PubMed1995

Double burst stimulation for monitoring neuromuscular blockade for tracheal intubation.

Responses to double burst stimulation were palpated every 15 s after intravenous administration of vecuronium 0.2 mg.kg-1 in 60 adult patients under anaesthesia. Intubating conditions and neuromuscular responses to tracheal intubation were assessed at disappearance of one or both palpable responses to double burst stimulation in groups of 30 patients randomly divided, although in group A patients, tracheal intubation could be performed at disappearance of one palpable response to double burst stimulation; 27 out of 30 patients (90%) had mild to moderate bucking on intubation. In this group, only five patients (16.66%) had good intubating conditions. In group B, where tracheal intubation was attempted at disappearance of both palpable responses, intubating conditions were good in 28 out of 30 patients (93.33%) and there was no response to tracheal intubation in 26 out of 30 patients (86.66%). Palpation of evoked response to double burst stimulation can be used to predict intubating conditions and neuromuscular response to tracheal intubation with nondepolarising muscle relaxants such as vecuronium.

Adult↗
PubMed1995

Somatosensory evoked potential changes following electro-acupuncture therapy in chronic pain patients.

Somatosensory evoked potentials were recorded in 20 healthy volunteers and 20 patients with chronic pain undergoing electro-acupuncture therapy. The values of absolute peak latency and amplitudes of N19 and P22 in the control group were compared with the corresponding baseline values in the study group and after electro-acupuncture therapy at three stages during a 10-treatment cycle. On these occasions the intensity of pain was recorded using a 100 mm visual analogue scale score. Each patient in the study group had 10 treatments given on alternate days. The absolute peak latency of N19 was significantly delayed (p < 0.05) in chronic pain patients when compared to the control group. This increase in latency of N19 persisted after the first electro-acupuncture treatment (p < 0.05), tended to revert to normal after the fifth treatment (p > 0.05) and reverted completely to control values after the 10th treatment (p > 0.05). Visual analogue scores also decreased significantly (p < 0.05) after the fifth and 10th electro-acupuncture sessions. These observations suggest that there is an interaction of the neural mechanisms of electro-acupuncture with the thalamic generator of somatosensory evoked potentials i.e. N19.

Acupuncture Analgesia↗
PubMed1995

Effect of early lead exposure on children's postural balance.

This study investigated the effect of chronic exposure to lead on children's ability to maintain upright postural balance as a biological marker of lead-induced modifications of the neuromotor system. For this study, 162 six-year-old children, with a five-year geometric mean lead concentration in blood of 11.9 micrograms/dL (range 4.0-28.0 micrograms/dL), were tested for postural balance with a microprocessor-based force platform system. An increase in blood lead was significantly associated with an increase in the variable postural sway--implying poorer postural balance. This association was not influenced by socio-economic, racial or environmental factors. This simple, objective and quick technique may be useful for assessing gross motor functions in children who are at or below the United States Centers for Disease Control's class III category and/or for monitoring the effectiveness of medical interventions aimed at reversing lead-associated impairment of upright postural balance.

Child↗
PubMed1995

Isolation, cultivation and partial characterization of a kinetoplastid flagellate from the hindgut of the water bug, Lethocerus indicus.

A new species of kinetoplastid flagellates was isolated from the hindgut of the giant water bug, Lethocerus indicus, and successfully cultured in modified glycerol beef extract medium. Light and electron microscopic studies as well as growth in various culture media are described. The flagellates were in three different shapes and sizes in the hindgut of the host as well as in the culture medium. Each form of the parasite contained a kinetoplast which was located near the basal body of the flagellate. The ultrastructural features of this species exhibit great similarity to other species of Bodo. The flagellate ingested bacteria, grew in culture, and was identical with that observed in the hindgut of the bugs. The name Bodo indica has been proposed for this kinetoplastid flagellate.

Animals↗
PubMed1995

Technetium-99m-HMPAO SPECT cerebral blood flow study in children with craniosynostosis.

UNLABELLED: Premature closure of cranial sutures (primary craniosynostosis) in children leads to characteristic skull deformities and prevents the constricted brain from growing normally. Although the cause remains unknown, several etiological factors have been cited. Recently, hypovascularity has been reported as a possible cause of craniosynostosis. METHODS: In a prospective study regional cerebral blood flow studies were carried out with 99mTc-HMPAO SPECT in seven children with craniosynostoses. Five preoperative and six postoperative studies were conducted and the results correlated with radiological and surgical findings. RESULTS: Preoperative studies revealed regional hypovascularity in the underlying cerebral hemisphere, corresponding to the fused sutures. Postoperative studies revealed disappearance of these perfusion defects in most cases, indicating normalization of perfusion following surgical decompression. CONCLUSION: This study establishes the presence of cerebral hypovascularity in craniosynostoses and suggests that early surgery and release of craniostenosis is essential to achieve optimum perfusion and brain development.

Brain↗