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Biomedical subjects

A Chakravarty

Publications and source records attributed to A Chakravarty.

At least 37 records · Page 2Linked to original sources
PubMed2002

Is squatting a triggering factor for stroke in Indians?

BACKGROUND: Undocumented observations of ours suggested increased occurrence of strokes in the early hours of the morning and in the toilets where most Indians still squat. The present study has been designed to assess the validity of this observation and to identify the likely triggering factor in stroke onset in such situations. MATERIAL AND METHODS: Part A of the study looked into stroke onset data of 100 consecutive CT-confirmed stroke patients specially in relation to time of day, place, posture and activity of the individual. Part B of the study included 67 healthy volunteers (age 24-49 years) whose supine and squatting blood pressure (BP) were measured and the differences noted. Part C of the study consisted of repeating the same procedure in 104 known hypertensives on treatment (age 28-60 years). RESULTS: Part A of the study revealed that most strokes (52%) occurred in the morning and at home (86%) and over a third (36%) while in toilets. Thirty-six per cent of the strokes occurred while the subjects squatted, mostly during the act of defecation. More than half of the haemorrhagic strokes occurred while the subjects were in squatting position. In normal healthy volunteers squatting produced a small (8.09 +/- 7.04 mmHg) but significant rise in systolic blood pressure (SBP) but not in diastolic blood pressure (DBP) (0.9 +/- 7.38 mmHg). In contrast, in treated hypertensives squatting produced a significantly higher rise in both SBP (14.49 +/- 11.63 mmHg) and DBP(9.10 +/- 9.19 mmHg). CONCLUSION: The relationship of the clinical observations regarding stroke onset with the BP changes noted on squatting in healthy as well as hypertensive subjects appears to be more than fortuitous. Squatting induced rise in BP appears to be an important triggering factor for stroke onset in subjects at risk in India.

Adult↗
PubMed2002

Growth failure in a child showing characteristics of Seckel syndrome: possible effects of IGF-I and endogenous IGFBP-3.

Seckel syndrome is an autosomal-recessive disorder with a frequency of less than 1/10 000 births in which there are multiple malformations including severe short stature. We report on a patient with Seckel syndrome with a current body height of -7.5 SDS. Laboratory investigations at the age of 19 months revealed high levels of IGF-I, IGF-II and IGFBP-3. These data suggested the existence of IGF-I resistance possibly caused by impairment of the IGF-I receptor (IGF-IR) or altered IGFBPs. The purpose of this investigation was to examine whether the growth retardation in a Seckel syndrome patient is related to an alteration in the IGF system. Analysis of IGF-IR mRNA of patient's and control fibroblasts by solution hybridization/RNase protection assay did not show differences of IGF-IR transcript expression or size. Affinity crosslinking studies using [125I]-IGF-I showed normal-sized IGF-IR-ligand complexes. Mutation analysis of the complete coding regions of the IGF-I and IGF-IR genes showed no evidence of genetic alterations. Ligand blot analysis of IGFBPs secreted by the patient's fibroblasts showed stronger signals than control cells. Quantitative measurement of IGFBP-3 in cell-conditioned media was performed by radioimmunoassay (RIA) and revealed a sixfold increase when compared to control fibroblasts. We conclude that in this patient with Seckel syndrome and severe growth impairment IGF-I resistance is possibly related to altered production of IGFBP-3.

Abnormalities, Multiple↗
PubMed2002

Squatting, blood pressure and stroke.

Most Indians still adopt squatting posture in toilets. In a group of 67 healthy volunteers, squatting produced a small (8.09 +/- 7.04 mm Hg) but significant rise in systolic blood pressure (SBP) but not in diastolic (DBP). However, in a group of randomly selected treated hypertensives (N=104) squatting produced a much greater and significant rise in both SBP (14.46 +/- 11.63 mm Hg) and DBP (9.10 +/- 9.19 mm Hg). The possible clinical significance of this rise of BP in squatting has been evaluated in 100 consecutive CT proved patients with stroke by analysing their stroke onset data in relation to time, place, posture and activity. Most strokes (52%) occurred in the morning hours (5 am-9 am) and at home (86%) and over a third (36%) while in toilets. Thirty six percent of strokes occurred when the subjects squatted, mostly during defecation. More than half of hemorrhagic strokes occurred in the squatting position. The relationship of these clinical observations with the BP changes noted above on squatting appears to be more than fortuitous. We would suggest that hypertensive subjects and those at risk of stroke should avoid squatting and urge physicians to check squatting BP while monitoring anti-hypertensive therapy.

Adult↗
PubMed2002

The neurology of eclampsia : some observations.

Nineteen patients admitted with diagnosis of eclampsia in a large general hospital between 1996 - 1999, were analyzed. Eight patients were referred to neurologists for assessment and management. All these patients had recurrent generalized seizures. Five patients developed visual disturbance. Neuroimaging (CT and/or MRI) revealed symmetrical occipital lesions in all. One patient had a large pontine lesion. Seizure control was achieved in all with intravenous phenytoin. All patients recovered fully without any residual neurological deficit and their radiological brain lesions resolved completely, in all except one case. The neurological manifestations and neuroimaging features in cases of eclampsia have been reviewed. A brief note on the pathogenesis of the cerebral lesions is included and the controversial aspect of seizure control in eclampsia highlighted.

Adult↗
PubMed2002

Crossed cerebral - cerebellar diaschisis: MRI evaluation.

MRI, done later in life, in two patients with infantile hemiplegia syndrome showed significant volume loss in the cerebellar hemisphere contralateral to the side of the affected cerebrum. The cerebellar volume loss seemed to correlate with the degree of volume loss in the contralateral cerebral hemisphere. These observations provide morphological evidence of the phenomenon of crossed cerebral-cerebellar diaschisis (CCD). Functional neuroimaging studies in support of the concept of CCD has been critically reviewed.

Adolescent↗
PubMed2002

A patient with optic pathway glioma, scoliosis, Chiari type I malformation and syringomyelia: is it Neurofibromatosis type 1?

A 22 years old girl had features of optic pathway glioma, scoliosis, Chiari type 1 malformation and cervical syringomyelia. She had no cutaneous lesions. We considered this combination to be more than coincidental and argue in favour of considering the case as a variant form of Neurofibromatosis type 1. The relevent literature in favour of our contention has been reviewed.

Adult↗
PubMed1997

A fast and robust dual-label nonradioactive oligonucleotide ligation assay for detection of factor V Leiden.

Activated protein C resistance is in almost all cases caused by the factor V Leiden mutation (FV:R506Q). Due to the high prevalence and clinical significance of the mutation reliable methods suited for processing large sets of samples are in demand. We here present the oligonucleotide ligation assay (OLA) with lanthanide labeled oligonucleotides for the detection of FV Leiden. The assay is based on time resolved fluorescence measurement of lanthanide labeled oligonucleotides (DELFIA: Delayed Enhanced Lanthanide Fluorescence Immuno Assay) and on the specificity of T-4 DNA Ligase to join two adjacent oligonucleotides only when the two are complementary to the PCR template at the ligation junction. The Europium/Samarium fluorescence pattern is specific for each of the three genotypes (G/G, G/A, A/A) and clearly separates the three genotypes. By using a wildtype probe (Samarium labeled) and a mutant-specific probe (Europium labeled) simultaneously an internal control of the assay is included in each reaction. The assay is simple to perform, can be partly automated and is ideal for processing large sets of samples.

DNA Ligases↗
PubMed1996

A prospective study of delta infection in fulminant hepatic failure.

Thirty one patients of HBV related Fulminant Hepatic Failure (FHF) were studied for the presence of delta infection and subsequently the clinical features, course and outcome of the delta infected cases was compared with those of delta uninfected cases. Out of 31 patients studied, 11 patients (35.8%) were reactive for anti-delta antibodies. There was no significant difference in age in delta reactive and non-reactive group. Hepatic encephalopathy was seen in all of the patients. The mean SGOT and SGPT were 378 +/- 88.74 U and 454 +/- 70.44 U respectively in anti-delta reactive group as compared to 239 +/- 74.94 U and 274.1 +/- 100.34 U respectively in anti-delta non reactive group (p < 0.05). During follow up, 10/11 patients (91%) died in anti-delta reactive group as compared to 13/20 patients (65%) in anti-delta non reactive group. So this study suggests that delta virus infection is quite common in India and it lead to excerbation of illness and carries a relatively poor prognosis for FHF.

Adult↗
PubMed1995

Insecticides: their effect on microorganisms and persistence in rice soil.

A field experiment was conducted to investigate the effect of four insecticides, HCH, phorate, carbofuran and fenvalerate, at recommended doses on the preponderance of bacteria, actinomycetes and fungi. We also measured the persistence of the insecticides in the rhizosphere soil of rice. HCH and fenvalerate stimulated the proliferation of all of the microorganisms significantly. Phorate increased the population of bacteria and actinomycetes. Carbofuran accentuated the preponderance of actinomycetes in soil. Insecticides, in general, did not have marked influence on the proliferation of Bacillus, Streptomyces, Aspergillus and Fusarium in soil. However, we observed a stimulation of growth of Staphylococcus, Proteus and Sarcina with HCH, Pseudomonas, Corynebacterium, Erysipelothrix and Rhizopus with phorate, Serratia, Corynebacterium, Klebsiella, Escherichia, Rhizopus and Humicola with carbofuran, and Staphylococcus, Sarcina, Klebsiella and Nocardia with fenvalerate. On the other hand, there was an inhibition in growth of Pseudomonas, Micrococcus, Nocardia and Penicillium with HCH, of Pseudomonas, Micrococcus and Penicillium with carbofuran, and of Pseudomonas, Micrococcus and Micromonospora with fenvalerate. Different types of insecticides exhibited differential patterns of dissipation in soil. HCH had the highest persistence followed by phorate, carbofuran and fenvalerate, respectively.

Actinomycetales↗