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Biomedical subjects

M Chakravarty

Publications and source records attributed to M Chakravarty.

12 recordsLinked to original sources

Hepatitis B infection in Eastern Indian families: need for screening of adult siblings and mothers of adult index cases.

OBJECTIVES: India, with its 43 million hepatitis B virus (HBV) carriers and absence of any national immunization programme, adds a substantial number of HBV infections to the HBV carrier pool yearly. The aim of this study was to assess the spread of HBV infection in families with an infected member and to identify the family members with the highest risk of infection in our community. METHODS: A total of 937 serum samples from 215 HBV-infected cases and 722 members of their households were screened prospectively for markers of HBV by commercial enzyme-linked immunosorbent assay. RESULTS: Among family members, 140 (19.4%) were HBsAg positive and 272 (37.6%) were negative for HBsAg but positive for either anti HBc or anti HBs. There were 145 HBsAg-positive adults among the index cases whose 133 adult siblings, 59 spouses and 59 mothers participated in the study. Interestingly, 28.81% mothers and 28.57% adult siblings of these adult index cases were positive for HBsAg compared with only 8.75% of their spouses (P < 0.001). Only 15.2% of the HBsAg-positive women in the childbearing age group were found to be HBeAg positive. CONCLUSIONS: Our results suggest that intrafamilial childhood horizontal transmission is important for HBV transmission in our community, and highlight the need for screening of adult siblings and mothers of adult HBsAg carriers in addition to their spouses and children.

Adolescent↗

Integrating applied anatomy in surgical clerkship in a problem-based learning curriculum.

Little attention has been given to structured teaching of applied anatomy to senior medical students in problem-based learning (PBL) medical schools. A course named "Anatomical Principles in Surgical Practice" was introduced at the Arabian Gulf University (AGU) in 2001 for fifth- and sixth-year medical students during their surgical clerkship rotation. The course aims to emphasize, update and integrate applied anatomical concepts that are essential for surgical practice. The course consists of 15 interactive sessions held weekly to ensure topics coincide with the surgical problem-solving sessions. A questionnaire was administered to students completing their surgical rotations (n = 131) seeking their perceptions about the new course during the academic years 2001, 2002 and 2003. To measure learning outcome, 70 students were also given pre- and post-tests. Positive responses were given by 85.2% of the students for course arrangement, by 92.0% for course content, by 88.3% for clinical correlation, by 95.2% for level of teaching and by 87.2% for overall judgment. The students' mean scores in the post-test (71.7%+/-11.7) was significantly higher than their mean scores in the pre-test (42.3%+/-12.6, p < 0.001). Students liked the course and reported feeling more confident in correlating anatomy with surgery during their rotations. By extending anatomical teaching into the clerkship phase, a link between basic medical and clinical sciences has been established that further enhances vertical integration within a PBL curriculum in a spiral fashion.

Anatomy↗

A study to determine the pharmacokinetics of gatifloxacin following a single oral dose.

Gatifloxacin is a broad spectrum fluoroquinolone that offers enhanced Gram-positive activity and anaerobic coverage to other fluoroquinolones. The pharmacokinetic parameters (Cmax, AUCo-t, tmax) of this drug have been evaluated to compare the single dose (400mg) bioavailability of gatifloxacin with the reference formulation. High performance liquid chromatography (HPLC) coupled with U-V detector set at 290 nm has been used to determine plasma concentration of 12 human volunteers as per DCGI (Drug Controller General of India) guidelines. The method has been validated over a linear range of 0.25 to 8 microg/ml from plasma. The minimum quantifiable concentration has been set at 0.25 microg/ml (% CV < 10%). The pharmacokinetic parameters are: Cmax = 4.366 +/- 0.44 microg/ml at tmax = 1.83 +/- 0.44 hour, AUCO0-t = 25.26 +/- 2.91 microg hour/ml, AUCo-inf = 33.68 +/- 4.31 microg hour/ml, Kel = 0.094 +/- 0.024/hour and t1/2 = 8.0 +/- 1.92 hour.

Administration, Oral↗

99Tcm-cystine, a renal function and imaging agent: a comparative study in dog with 131I-hippurate and 99Tcm-glucoheptonate to evaluate its functional and imaging characteristics.

99Tcm-cystine, which has been proposed as a renal radiopharmaceutical for evaluating renal morphology and function in a single experiment, is compared with 131I-orthoiodohippurate (OIH) with respect to its renal clearance and extraction parameters and with 99Tcm-glucoheptonate (GHA) regarding its imaging characteristics. In spite of its comparable renal accumulation with 131I-OIH, its clearance (10.1 +/- 1.0 ml min-1 kg-1) was lower than that of 131I-OIH (21.5 +/- 0.9 ml min-1 kg-1) but was higher than that of 125I-iothalamate (5.4 +/- 0.6 ml min-1 kg-1). Extraction efficiencies of 99Tcm-cystine, 131I-OIH and 125I-iothalamate were 39 +/- 5, 64 +/- 4 and 27 +/- 3, respectively. The glomerular filtration components of 99Tcm-cystine and 131I-OIH were 26 and 16% of their respective clearances. In probenecid-treated animals the clearance of both agents was affected to a similar extent and fell to half of their respective control values, whereas tubular secretory components were found to be 19 and 31% of the controls. The kidney images obtained with 99Tcm-cystine were superior to those obtained with 99Tcm-GHA at different time points. Therefore, considering both renal function and imaging properties of 99Tcm-cystine it appears that this radiopharmaceutical offers some definite advantages over the currently available renal agents and commands further study.

Animals↗

Technetium-99m amino acid chelates: correlation of their physico-chemical and physiological parameters. Part I.

Ten alpha-aminocarboxylic acids were chelated with 99mTc and purified by sephadex gel chromatography. Their hepatobiliary and renal excretion patterns were determined in rats. It was observed that lipophilicity of these chelates is the only determinant in governing their hepatobiliary excretion, whereas their renal excretion is dependent on some other factors in addition to lipophilicity. Depression of renal excretion in presence of probenecid indicated an interaction of renal tubular transport enzymes with these chelates, which was explained from their hexacoordinated dioxotechnetium (V) chelate structure (II).

Amino Acids↗

Effect of piracetam, a nootropic agent, on experimental gastric ulcers in rat.

Piracetam, used clinically for cognitive disorders, was found to have significant anti-ulcerogenic activity against immobilization stress- and aspirin-induced gastric ulcers in rats. The anti-ulcer effect of piracetam was exerted by augmentation of mucosal resistance. This was indicated by the significant attenuation of the decrease in total carbohydrate: protein ratio induced by aspirin. It also reversed the marked increase in gastric juice protein and DNA induced by aspirin, indicating that piracetam attenuated the augmented mucosal cell exfoliation induced by the ulcerogen. The drug also increased gastric mucosal serotonin concentrations. Piracetam, thus appears to have a profile of activity associated with cytoprotective agents.

Animals↗

Vascular complications related to drug abuse.

Vascular complications resulting from drug abuse constitute a widespread and common clinical problem. A 3-year experience with 32 vascular complications (13 arterial, 19 venous) related to intravenous drug abuse is reported. Fourteen (48%) of the 29 patients in this series presented with septic vascular complications. These infections were a major cause of morbidity and mortality, resulting in two hospital deaths and a disrupted arterial repair. In addition, intra-arterial drug injection caused digital gangrene in two patients. Early recognition, diagnostic arteriography and venography, and planned therapeutic interventions are possible if a high level of suspicion is maintained.

Adult↗

Utilization of angiography in trauma.

In conclusion, I have tried to present a rational approach to the work-up of the traumatized patient. One must consider the mechanism of injury, the region where the most damage has been inflicted, and, most important of all, the clinical condition in which the patient arrives. With injuries in most of the body parts, there will not be time to perform any angiographic procedure in category 1 patients. They may or may not have intraoperative or postoperative angiograms. Category 2 patients benefit most from angiography; therapy will often be dictated based on the results. Category 3 patients are studied as necessary; the decision is made with strong consideration given to the type of trauma and the proximity of major vessels. For all groups of patients, angiography should be performed as soon as possible to avoid the sequelae of delay in treatment, as pointed out previously, particularly delayed rupture of arteries. This is becoming increasingly important as angiography has started to play a bigger role in the early therapeutic intervention of the traumatized patient. It is expected that appropriate and increasing use of arteriography will improve organ, limb, and patient salvage by early surgical or transcatheter techniques.

Abdominal Injuries↗