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Biomedical subjects

A Srivastava

Publications and source records attributed to A Srivastava.

At least 109 records · Page 6Linked to original sources
PubMed2001

Perceptual development in relation to nutritional status.

The present study was conducted on 180 children in the age group 5-10 years. These children were divided accordingly their ages into 3 sub-groups i.e. 5-6, 7-8 and 9-10 years respectively. In each group 60 children were studied. For the assessment of perceptual skills each child was tested with the help of Picture Ambiguity Test. Responses to the ambiguous cards were scored with respect to time taken to react in each card and ability of the child to perceive figure and ground relationship i.e. centration and decentration. The observations showed that with increase in age, centration effect reduces and majority of the children start decentring their perception by middle childhood. Further, children in higher age group took lesser time to respond on different ambiguous cards. When the responses of well-nourished and undernourished children were compared for perceptual flexibility in terms of part-whole perception i.e. centration and decentration; no difference was observed between the two groups. There was a significant difference in the performance of well-nourished and undernourished children when time to respond on ambiguous card was compared. Well-nourished children took lesser time to respond on different ambiguous cards. These observations in general suggest that poor nutrition may result in impaired perceptual abilities in children.

Analysis of Variance↗
PubMed2001

Polymyositis--an unusual manifestation of chronic graft-versus-host disease.

Polymyositis is a rare autoimmune manifestation of chronic graft-versus-host disease (GVHD) characterized by muscle pain, weakness, and an increase in muscle-related enzymes that responds well to treatment with immunosuppressive agents such as steroids and cyclosporine. We describe a case in which polymyositis was the main manifestation of chronic GVHD that occurred 12 months after allogeneic bone marrow transplantation in a patient with acute lymphocytic leukemia (ALL). The polymyositis responded well to treatment with steroids and cyclosporine, with no relapse of symptoms on tapering of the medication.

Adolescent↗
PubMed2001

Multiple effects of chromate on the photosynthetic apparatus of Spirodela polyrhiza as probed by OJIP chlorophyll a fluorescence measurements.

Chromate (Cr) decreases the growth of Spirodela polyrhiza. The fronds lost their pigments. The O2 evolution was also decreased. The Cr effect was found to be dose dependent. The toxic effects of Cr have further been studied on the photosynthetic activity of Spirodela polyrhiza by means of the chlorophyll a (Chl a) fluorescence transient O-J-I-P. The Chl a fluorescence transients were recorded in vivo with high time resolution and analyzed according to the JIP-test which can quantify the photosystem II behavior. Cr treated plants show a decrease in yield for primary photochemistry, phi Po. The performance index of PSII, PIABS, which is the combination of the indexes of three independent parameters, (1) the total number of active reaction centers per absorption (RC/ABS), (2) yield of primary photochemistry (phi Po) and (3) efficiency with which a trapped exciton can move an electron into the electron transport chain (psi 0), decreased due to Cr treatment. Chromate sensitivity varies within plant populations. In summary Cr affects several targets of PSII. More specifically, the main targets of Cr, according to the JIP-test, can be listed as a decrease in the number of active reaction centers and damage to the oxygen-evolving complex.

Araceae↗
PubMed2001

Modified iridoid glycosides as anti-implantation agents: inhibition of cell adhesion as an approach for developing pregnancy interceptive agents.

Structural modifications in iridoid glycosides and evaluation of their efficacy on adhering capability (in vitro) of immature hamster uterine epithelial cells to the substratum have been studied. Out of 31, eight compounds in vitro, five compounds in utero and two in vivo showed adhesion/implantation preventing activity, respectively. The results provide an indication for further exploration in the line of development of anti-adhesive agents.

Animals↗
PubMed2001

Correlation between p53 gene mutations and circulating antibodies in betel- and tobacco-consuming North Indian population.

Alterations in p53 tumour suppressor gene and its expression may be implicated in the pathogenesis of betel- and tobacco-related oral cancer. There is wide regional variation in betel- and tobacco-consuming habits in different parts of the Indian subcontinent. The purpose of this study was to determine the correlations between p53 gene mutations, protein accumulation and serum antibodies in oral precancer and cancer. We analysed 30 potentially malignant oral lesions (leukoplakia) and 30 oral squamous cell carcinomas (SCCs) from northern India because the betel quid-consuming habits are different from those prevalent in other regions of India. p53 mutations were analysed by polymerase chain reaction amplification of genomic DNA and direct sequencing, p53 protein accumulation by immunohistochemical analysis and circulating p53 antibodies by ELISA. p53 gene mutations, analysed within exons 5-9, were observed in five out of 30 (17%) potentially malignant oral lesions and seven out of 30 (23%) oral SCCs. All the mutations were base substitution mutations. Three missense and two nonsense mutations were observed in potentially malignant oral lesions, while six missense and one nonsense mutations were identified in oral SCCs. The probable hot spots for the mutations were identified at codons 126, 136 and 174, which have not been observed thus far. A good correlation was observed between p53 missense mutation, p53 antibodies and p53 protein accumulation in matched potentially malignant and malignant oral lesions. All the potentially malignant and cancerous lesions harbouring missense mutations showed accumulation of p53 protein and the majority of these patients showed circulating p53 antibodies suggesting that serological detection of p53 antibodies may serve as a surrogate marker for p53 alterations in oral lesions.

Adolescent↗
PubMed2001

Sequential anastomosis of accessory renal artery to inferior epigastric artery in the management of multiple arteries in live related renal transplantation: a critical appraisal.

In live related renal transplant program, management of multiple renal arteries (MRA) is technically demanding and used to be considered a relative contraindication because of increased risk of vascular and urologic complications. We present a retrospective analysis of the outcome of grafts with MRA and suggest certain guidelines. Of the 680 live related kidney transplantations done, 53 allografts had MRA. Cases were grouped according to the reconstruction technique: group A, MRA reconstructed ex vivo into a single renal artery (n=27); group B, MRA with multiple anastomoses in vivo (n =13); group C, MRA with sequential revascularization using inferior epigastric artery (n=11). We compared serum creatinine, acute tubular necrosis, rejection rates and the rewarm ischemia time between the three groups. Overall patient survival and graft survival were excellent (100 and 96%). Mean serum creatinine at 1 yr did not differ significantly between the three groups. Rewarm ischemia time was significantly less in group C (p<0.01). Incidence of acute tubular necrosis and rejection episodes was also less in group C although the difference was statistically significant only between group C and group B. We conclude that allografts with MRA can be used successfully in a live related renal transplantation program. Bench reconstruction should be done whenever possible. For reconstruction of an accessory vessel, inferior epigastric artery with sequential revascularization is recommended.

Adolescent↗
PubMed2001

Cyclosporin A withdrawal in live related renal transplantation: long-term results.

Cyclosporin A (CsA) withdrawal after 1 yr of stable graft function has been shown to be beneficial in cadaveric renal transplantation. This strategy could be even more suitable for 'immunologically advantaged' grafts as in live related renal transplantation. We report the long-term outcome of patients in a live related transplantation programme undergoing early (between 1989 and 1992) and late (1993 onwards) CsA withdrawal as compared with those on long-term low dose CsA (1993 onwards). Two-hundred and fifty-two patients were divided into three groups based on the following immunosuppressive protocol: group ECyW (n=99), early CsA withdrawal (9 months after transplantation); group LCyW (n=44), late CsA withdrawal (median 16 months, range 13--22 months after transplantation); and group LDCy (n=109), long-term low dose CsA. The median period of follow-up was 66 months after transplantation (range 43--84 months). There was no difference in the actuarial 6-yr patient or graft survival among the three groups. Acute rejection episodes were more frequent in ECyW (54.4%) than in LDCy (31.8%) and LCyW (23.8%) (p=0.001). The risk of developing late (> or =9 months) acute rejection was highest in ECyW 32/99 (32.3%) as compared with LCyW 8/44 (18.4%; p=0.08) and LDCy 8/109 (7.3%; p=0.0001). Of the 32 ECyW patients who developed acute rejection episodes after CsA withdrawal, 13 (40.6%) lost their grafts either due to uncontrolled acute rejection or to chronic rejection. Chronic rejection was higher in ECyW (24%) than in LCyW (11%; p=0.04) and LDCy (17%; p=0.17). Antihypertensive requirement was highest in patients maintained on low dose CsA. Graft function, as measured by serum creatinine levels, was significantly better in LCyW (1.24+/-0.4 mg%) as compared with ECyW (1.49+/-0.5 mg%) and LDCy (1.48+/-0.6 mg%). Early CsA withdrawal after live related renal transplantation is associated with a significant risk of acute rejection and subsequent chronic rejection. Slow withdrawal after 1 yr is safe and more economical than the long-term administration of low dose CsA.

Acute Disease↗
PubMed2001

Allogeneic bone marrow transplantation in the developing world: experience from a center in India.

We describe our experience of setting up an allogeneic BMT program at the Christian Medical College Hospital, Vellore over a period of 13 years, from October 1986 to December 1999. Two hundred and twenty-one transplants were performed during this period in 214 patients, with seven patients undergoing second transplants. Indication for BMT were thalassemia major - 106 (48%), CML - 30, AML - 35, ALL - 10, SAA - 22, MDS - six and six for other miscellaneous disorders. The mean age of this patient cohort was 15.6 years (range 2-52). Graft-versus-host disease of grades III and IV was seen in 36 patients (17%) and this was the primary cause of death in 20 patients (9.2%). All patients and donors were CMV IgG positive. Sepsis was the primary cause of death in 16 patients (7.4%), 10 bacterial, four fungal and two viral. One hundred and ten of this series of patients are alive and disease free (50%) with a median follow-up of 24 months (range 2-116). These results are comparable to those achieved for patients with similar disease status in transplant units in the Western world and cost a mean of US$15 000.

Adolescent↗
PubMed2001

Tuberculosis among allogeneic bone marrow transplant recipients in India.

Allogeneic bone marrow transplant recipients have severe impairment of cell-mediated immunity and hence a higher incidence of mycobacterial infections might be expected in regions where tuberculosis is common. We reviewed the case records of 217 patients who underwent allogeneic bone marrow transplantation during the period 1986-1999 at our center in India. Mycobacterial infections were diagnosed in three patients (1.38%). All patients presented with extrapulmonary disease. Two patients had disseminated tuberculosis with one of these being diagnosed on autopsy studies. The third patient had tuberculosis involving the cervical lymph node and dorsal spine. Two patients treated with antituberculous therapy are well. Infection with Mycobacterium tuberculosis is not a common problem in allogeneic bone marrow recipients even in an endemic area, but when it occurs, it is usually disseminated with predominantly extrapulmonary involvement.

Adult↗
PubMed2001

Evaluation of existing limited sampling models for busulfan kinetics in children with beta thalassaemia major undergoing bone marrow transplantation.

Busulfan pharmacokinetic parameters are useful in predicting the outcome of allogeneic bone marrow transplantation (BMT). Standard pharmacokinetic measurements require multiple blood samples. Various limited sampling models (LSM) have been proposed for reducing the sample number required for these measurements, essentially for patients with malignant disorders undergoing BMT. This study was undertaken to evaluate the existing LSM for busulfan pharmacokinetics to find out the most suitable method for patients with thalassaemia major undergoing BMT. Busulfan levels in plasma samples were analysed by HPLC. The AUC calculated by non-compartmental analysis using the program 'TOPFIT' was compared with previously published LSMs. Our seven sample pharmacokinetic data for AUC calculation was compared with the published LSMs. The three sample models suggested by Chattergoon et al and Schuler et al showed significant agreement with AUC TOPFIT (R(2) = 0.98 and 0.94, respectively) in our clinical context. Other models resulted in significant over or under representation of observed values (Vassal's model R(2) = 0.61; Chattergoon's two sample model R(2) = 0.84; four sample model R(2) = 0.83; Schuler's two sample model R(2) = 0.79). By these data the three sample LSM proposed by Chattergoon et al and Schuler et al are suitable for calculation of the AUC in patients with thalassaemia major undergoing BMT conditioned with oral busulfan.

Adolescent↗
PubMed2001

Choice of factor concentrates for haemophilia: a developing world perspective.

Provision of factor concentrates continues to be the single greatest challenge in providing effective haemophilia care in the developing world. While concerns for ultimate safety and very high purity dominate the selection of factor concentrates in developed countries, availability and cost are the pressing issues in developing countries. There certainly is concern for reasonable safety but purity is often considered an unaffordable luxury. Cost-effective protocols need to be designed for factor replacement in these countries where liberal on-demand therapy and prophylaxis are not possible. It is also essential to establish a good transfusion service for collecting adequate quantities of safe plasma. Support from government and health insurance is required to allow access to at least modest quantities of virus-inactivated factor concentrates. Depending on the situation in each country, factor concentrates may be imported, contract-fractionated or locally produced. Paradigms of effective management of this problem exist within the developing world. Until such time as these examples are widely emulated, less safe products will continue to be used in situations where a distinction frequent needs to be made between what is ideal and what is practical.

Blood Coagulation Factors↗
PubMed2001

Efficient uptake of Yersinia pseudotuberculosis via integrin receptors involves a Rac1-Arp 2/3 pathway that bypasses N-WASP function.

Efficient uptake of Yersinia pseudotuberculosis into cultured mammalian cells is the result of high-affinity binding of invasin to beta1 chain integrins. We demonstrate here that uptake requires Rac1 and Arp 2/3 function. Bacterial uptake was stimulated by GTPgammaS, but was inhibited in mammalian cells transfected with the interfering Rac1-N17 derivative. Rac1 was found to be activated in response to integrin engagement by invasin, whereas Rac1 and Arp 2/3 were found to be intensely localized around phagosomes bearing bacteria, indicating a specific role for Rac1 signalling from the nascent phagosome to downstream effectors. To determine whether the Arp 2/3 complex was a component of this proposed pathway, cells overproducing various derivatives of Scar1/WAVE1, an Arp 2/3-binding protein, were analysed. Sequestration of Arp 2/3 away from the phagocytic cup as a result of Scar1/WAVE1 overproduction dramatically inhibited uptake. To determine whether signalling from Rac1 to Arp 2/3 occurred via N-WASP, uptake was analysed in a cell line lacking expression of WASP and N-WASP. Uptake was unaffected by the absence of these proteins, indicating that beta1 integrin signalling from Rac1 to Arp 2/3 can occur in the absence of N-WASP function.

3T3 Cells↗
PubMed2001

Autoimmune liver disease in children.

BACKGROUND AND AIM: Autoimmune liver disease (AILD) in children progresses to cirrhosis and liver failure if not diagnosed and managed in time. We prospectively analyzed our patients with liver disease for autoimmune etiology and their outcome with treatment. METHODS: All patients with liver disease were evaluated with liver function tests, abdominal ultrasonography, endoscopy, liver biopsy, viral markers and investigations for Wilson's disease. Immunoglobin (Ig)M hepatitis A virus, hepatitis E virus (HEV) and IgM hepatitis B core antibody were tested if acute viral hepatitis was suspected. Antinuclear antibody (ANA), antismooth muscle antibody (SMA), and liver kidney microsomal antibody (anti-LKM-1) were done in all cases. Autoimmune liver disease was diagnosed when one or more autoantibodies tested positive (> 1:40), and no other etiology of liver disease was identified. We also applied criteria proposed by the International Autoimmune Hepatitis Group. Cases diagnosed to have AILD were treated with immunosuppressive drugs. RESULTS: Autoimmune liver disease constituted 3.9% (6/153; median age and duration of illness 8.5 years and 3 months, respectively) of chronic liver disease cases. Four patients had acute hepatitis-like presentation. Of the six cases, two each were ANA and SMA +; one was anti-LKM-1 +, and the other was positive for both SMA and anti-LKM-1. Three of the patients achieved remission with combination therapy of oral prednisolone (OP) and azathioprine (AZT), and one with only OP. The other two patients were not treated. Two of the patients in remission have been weaned off from immunosuppressive therapy, and one is in a withdrawal phase. Another patient, while in biochemical remission developed superimposed anicteric acute HEV infection. CONCLUSION: Although AILD is uncommon in children, its search is rewarding, as remission is achieved with immunosuppressive therapy. Superimposed acute viral hepatitis can occur in endemic areas.

Adolescent↗
PubMed2001

Acute urinary retention: defining the need and timing for pressure-flow studies.

OBJECTIVE: To investigate the utility of "late" pressure-flow studies in predicting the outcome of prostatectomy for acute urinary retention. PATIENTS AND METHODS: Fifty-eight patients with acute urinary retention were prospectively assessed using the International Prostate Symptom Score and pressure-flow studies at a median (range) of 24 (13-60) days after the episode of retention, and before transurethral resection of the prostate. Bladder outlet obstruction and bladder contractility were graded using a modified adaptation of Schäfer's passive urethral linear resistance relation. RESULTS: Fifty-six (97%) patients generated a voluntary detrusor contraction, with a mean (range) detrusor pressure at maximum flow of 72.7 (5-144) cmH2O, and 43 (75%) patients were deemed to be obstructed. Eight (16%) patients failed to void after prostatectomy and required clean intermittent catheterization. There were statistically significant differences between successful and unsuccessful patients in mean (SD) age, at 66.30 (6.9) vs 78.8 (2.6) years (P = 0.001), detrusor instability (49% vs 0%, P = 0.01), inability to void during pressure study (8% vs 75%, P = 0.001), and maximal detrusor pressure in the voiding phase, at 80 (36.0) vs 19 (11.2) cmH2O (P = 0.001). CONCLUSIONS: In patients with acute urinary retention, pressure-flow studies undertaken after a period of adequate bladder rest (> 3 weeks) are useful in predicting the surgical outcome. Old age, absence of bladder instability, inability to void during the pressure-flow study and a maximal detrusor pressure of < 20 cmH2O are associated with a poor outcome after prostatectomy.

Acute Disease↗
PubMed2001

Immunohistochemical expression of transforming growth factor alpha and epidermal growth factor receptor in pancreatic endocrine tumors.

Coexpression of transforming growth factor alpha (TGF-alpha) and its receptor epidermal growth factor receptor (EGFR) is known to be associated with aggressive biologic behavior and adverse clinical outcome in a variety of tumors, including pancreatic adenocarcinomas. However, very little information is currently available as to whether this is true of pancreatic endocrine tumors (PETs) as well. Thirty-five PETs were retrospectively studied for immunohistochemical expression of TGF-alpha, the intracellular and extracellular domains of EGFR, and various hormonal secretory products. Proliferative activity was additionally studied (in 20 cases only) using the MIB-1 antibody. Thirty-one (89%) of 35 tumors were reactive for 1 or more of the peptide hormones tested; 22 (63%) tumors were positive for TGF-alpha; and 23 (65%) were positive for the intracellular and/or extracellular domain of EGFR. Based on their TGF-alpha and EGFR expression, these tumors could be classified into 4 groups. Of the 10 tumors in group I (positive for TGF-alpha and the complete EGFR molecule), 3 were malignant, 6 were >2 cm in diameter, 5 were functional, and 1 had a proliferative index of >40%. The 12 tumors in group II (positive for TGF-alpha but negative for the intracellular and/or extracellular domain of EGFR) included 4 malignant tumors, 4 PETs >2 cm in diameter, 8 functional, and 1 with a proliferative index of >40%. The 7 PETs in group III (positive for the intracellular/extracellular domain of EGFR alone) included 3 malignant tumors, 3 PETs >2 cm in diameter, and 3 functional tumors. The 6 tumors in group IV (completely negative for both TGF-alpha and EGFR) included 4 malignant tumors, 3 PETs >2 cm in diameter, and 4 functional lesions. Therefore, immunohistochemical expression of TGF-alpha and EGFR, either alone or in concert, shows no correlation with size, functional status, secretory profile, or biologic behavior and hence cannot be used as a marker of malignancy in this group of tumors.

Adenoma, Islet Cell↗
PubMed2001

New naphthoquinones from Arnebia hispidissima roots.

Besides shikonin and arnebifuranone, two new shikonin esters isolated from the roots of Arnebia hispidissima have been characterized as butylshikonin and 2'-methyl-hexa-1',3'-dienoylshikonin by physicochemical methods. Arnebifuranone is the first report from this species.

Food Coloring Agents↗