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Biomedical subjects

R Kashyap

Publications and source records attributed to R Kashyap.

At least 73 records · Page 4Linked to original sources
PubMed2000

Acquired haemophilia - a study of ten cases.

Clinico-haematological features in 10 patients with acquired Haemophilia are presented. Three patients had FVIII inhibitors following pregnancy while in six the cause for development of inhibitors could not be determined. One patient had acquired von Willebrand's disease. Lupus anticoagulant coexisted with Factor VIII inhibitors in three patients. All patients presented with sudden onset of bleeding without any past or family history of a bleeding disorder. Factor VIII inhibitor levels ranged from 8 to 512 Bethesda units in the nine patients. Immunosuppressive therapy was given to 8 patients, consisting of CVP regimen or corticosteroids with endoxan or cyclosporin. Seven patients had clinical and laboratory responses and one patient did not respond. One patient had severe postpartum bleeding with acute shock which was controlled with FEIBA. Diagnosis and management of idiopathic acquired Haemophilia, thus, continues to be a major challenge, and among acquired Haemophilia, postpartum Haemophilia has good prognosis.

Adrenal Cortex Hormones↗
PubMed2000

Long-term survival after liver transplantation in 4,000 consecutive patients at a single center.

OBJECTIVE: To evaluate the long-term survival outcomes of a large cohort of liver transplant recipients and to identify static and changing factors that influenced these outcomes over time. SUMMARY BACKGROUND DATA: Liver transplantation has been accepted as a therapeutic option for patients with end-stage liver disease since 1983, with continual improvements in patient survival as a result of advances in immunosuppression and medical management, technical achievements, and improvements in procurement and preservation. Although many reports, including registry data, have delineated short-term factors that influence survival, few reports have examined factors that affect long-term survival after liver transplantation. METHODS: Four thousand consecutive patients who underwent liver transplantation between February 1981 and April 1998 were included in this analysis and were followed up to March 2000. The effect of donor and recipient age at the time of transplantation, recipient gender, diagnosis, and year of transplantation were compared. Rates of retransplantation, causes of retransplantation, and cause of death were also examined. RESULTS: The overall patient survival for the entire cohort was 59%; the actuarial 18-year survival was 48%. Patient survival was significantly better in children, in female recipients, and in patients who received transplants after 1990. The rates of retransplantation for acute or chronic rejection were significantly lower with tacrolimus-based immunosuppression. The risk of graft failure and death was relatively stable after the first year, with recurrence of disease, malignancies, and age-related complications being the major factors for loss. CONCLUSION: Significantly improved patient and graft survival has been observed over time, and graft loss from acute or chronic rejection has emerged as a rarity. Age-related and disease-related causes of graft loss represent the greatest threat to long-term survival.

Adolescent↗
PubMed2000

Hemophilia.

Explore the source record for details and available documents.

Child↗
PubMed1999

Adjusting the distance of electrochemical microsensors from secreting cell monolayers on the micrometer scale using impedance.

There are emerging applications of electrochemical microsensors where the distance of the sensor from an insulating plane needs to be adjusted and/or accurately known. The plane may be merely an obstruction or the source of a species whose release rate needs to be measured. An example is in cell secretion studies where a monolayer of cells is stimulated to secrete ions and/or other biochemical species which then diffuse away from the cells while being measured by a microsensor. Sensor response will thus depend on both the rate of release and the distance of the sensor from the cells. To obtain accurate release rates, the precision of the scheme to control electrode distance from the monolayer needs to be on the micrometer scale for species with ionic diffusivities. Optical (stereomicroscope and microruler) and mechanical (precalibrated micrometer screw) methods to precisely position the electrode are difficult to use under realistic circumstances (due to opaqueness of the chamber, and/or the medium, or irreproducible chamber depth). In this work we propose to correlate electrochemical cell impedance with sensor distance. This scheme has been used to adjust the distance of a chloride (tip diameter approximately 250 microns) and a potassium (tip diameter approximately 1000 microns) ion-selective microelectrode in the 0-250- and 0-2500-micron range, respectively, from a planar obstruction as well as from a monolayer of cells with a best precision of +/- 5 microns (n = 6) for the chloride and about +/- 20 microns for the potassium sensor. Larger electrodes have a broader range of distances over which they are sensitive, albeit with a poorer spatial resolution. This was verified by using Ag disk electrodes of 250 and 500 microns in diameters in AgNO3 solution.

Buffers↗
PubMed1999

The clinical significance of cytomegaloviral inclusions in the allograft kidney.

BACKGROUND: Renal allografts are a frequent site of subclinical cytomegalovirus (CMV) infection diagnosed by culture, but histologic inclusions occur in less than 1% of biopsies. The natural history of this subgroup of patients has been reported only occasionally, mostly before the availability of ganciclovir therapy. METHODS: We analyzed the clinical parameters and pathologic findings in 10 patients with CMV inclusions at allograft biopsy. RESULTS: The patients were 29-72 years old, and 9 of 10 (90%) had previous episodes of acute rejection, 3 of whom needed OKT3 administration. Histopathologic examination of the allografts showed interstitial inflammation with tubulitis in 7 of 10 (70%) patients; in 3 of 10 (30%) patients, viral inclusions were present in the glomerular capillary endothelia without any associated inflammatory response. Morphologic criteria for acute transplant glomerulopathy or proliferative glomerulonephritis were not satisfied. Extrarenal viral inclusions were documented in the gastrointestinal tracts of 2 of 10 (20%) patients. The patients were treated with reduced immunosuppression and ganciclovir. Five patients lost their grafts 56.6+/-86.6 days (range, 4-210 days; median, 21 days) after initial diagnosis. The serum creatinine in the remaining five patients was 3.3+/-2.0 mg/dl (range, 1.2-6.5 mg/dl; median, 2.5 mg/dl) 77+/-16 days (range, 56-101 days; median, 77 days) after transplantation. Histopathologic examination showed no residual viral inclusions in 5 of 7 (71.4%) follow-up specimens available for examination. CONCLUSIONS: CMV inclusions in renal allograft biopsies typically occur after treatment for rejection. Ganciclovir eradicates replicative virus, but graft outcome is determined by coexisting acute rejection and chronic allograft nephropathy. Graft loss primarily attributable to CMV was not observed.

Adult↗
PubMed1999

Danazol therapy in cyclic acquired amegakaryocytic thrombocytopenic purpura: a case report.

Cyclic acquired amegakaryocytic thrombocytopenic purpura (AATP) is a rare disorder characterized by periodic fluctuations in the platelet counts due to a defect in the platelet production. We describe a 42-year-old female with cyclic AATP, in whom the cyclic fluctuations in the platelet counts ceased with danazol therapy. The pathogenesis of the disease and the possible mechanisms of danazol action have been reviewed.

Adult↗
PubMed1999

Primary adult liver transplantation under tacrolimus: more than 90 months actual follow-up survival and adverse events.

The introduction of tacrolimus has shown decreased rates of acute and steroid-resistant rejection after liver transplantation (LTx). The aim of the present study is to examine the long-term efficacy and safety of tacrolimus in primary liver transplant recipients. The first 121 consecutive adults (aged >16 years) who underwent primary LTx at a single center from August 1989 to February 1990 were followed up until August 1997. The mean follow-up was 93.2 +/- 1.2 months (range, 90.5 to 96.5 months). Patient survival, graft survival, rate of rejection, and adverse events were examined. The actual 7-year patient survival rate was 67.8%, and the graft survival rate was 63.6%. Infections, recurrence of disease, de novo malignancies, and cardiovascular events constituted the main causes of graft loss and death in the long term. Graft loss related to acute or chronic rejection was rare. The rate of acute rejection beyond 2 years was approximately 3% per year, and most rejections were steroid responsive. Approximately 70% of the patients received only tacrolimus after 1 year. Four patients developed end-stage renal disease, and 2 patients underwent kidney transplantation. Hyperkalemia and hypertension were observed in one third of the patients. New-onset insulin-dependent diabetes mellitus was observed in 9% and 13% of the patients at the 1-year and 7-year follow-up, respectively. Seven patients developed de novo malignancies, including two skin malignancies. Six patients developed posttransplantation lymphoproliferative disorder during the entire follow-up period. Actual patient and graft survival at 7 years was excellent, and few adverse events developed after the first year. Graft loss from acute or chronic rejection was rare under tacrolimus, and approximately 70% of the patients were steroid free on tacrolimus monotherapy after the first year after LTx.

Adult↗
PubMed1999

What have we learned about primary liver transplantation under tacrolimus immunosuppression? Long-term follow-up of the first 1000 patients.

OBJECTIVE: To summarize the long-term efficacy and safety of tacrolimus in orthotopic liver transplant (OLT) recipients, as well as to examine the factors that influence long-term morbidity and mortality rates. BACKGROUND: Tacrolimus (FK506, Prograf) was introduced as primary immunosuppression for primary liver transplantation in 1989; many subsequent trials have verified the association of tacrolimus with decreased rates of acute rejection and steroid-resistant rejection after OLT. Cumulative experience with tacrolimus has also defined its short- and intermediate-term toxicity. METHODS: One thousand consecutive patients undergoing primary OLT at a single center from August 1989 to December 1992, under tacrolimus immunosuppression, were followed until January 1999. Patients were categorized by age. Mean follow-up was 93.4+/-11 months after OLT. Patient survival, graft survival (with corresponding causes of death and retransplantation), and rejection rates (and corresponding doses of immunosuppression) were examined as efficacy parameters. Hypertension, renal function, incidence of malignancies, incidence of diabetes, and other toxicities were examined as safety parameters. RESULTS: Actual 6-year overall patient survival rate was 68.1% and graft survival rate was 62.5%, with significant differences in the patterns of survival among the different age groups. After the first post-OLT year, infection, recurrence of disease, de novo malignancies, and cardiovascular events were the main causes of graft loss and death during the long-term follow-up. Graft loss related to either acute or chronic rejection was rare. The rate of acute rejection beyond 2 years was approximately 3% per year, and most were steroid-responsive. Approximately 70% of the patients were receiving tacrolimus monotherapy beyond year 1; at the latest follow-up, 74.2% were maintained on tacrolimus alone. In 6.1% of the survivors, end-stage renal disease developed during the follow-up period, requiring either dialysis or kidney transplantation. Hyperkalemia and hypertension was observed in approximately one third of the patients. Insulin-dependent diabetes mellitus (including patients who had diabetes before the transplant) was observed in 14% in year 1, dropping to 11% in year 7. In 82 patients, de novo malignancies developed; in 41 patients, lymphoproliferative disorders developed during the entire follow-up period. CONCLUSIONS: Long-term patient and graft survival rates are excellent under tacrolimus immunosuppression. Pediatric patients have a better long-term outcome than adults, in part because of the limited recurrence of the original disease, which was the most common cause of late graft loss (other than patient death, most commonly the result of late de novo malignancies and cardiovascular events). Graft loss from late rejection was rare.

Adolescent↗
PubMed1999

Clinico-haematological profile of isolated PF3 availability defect: therapeutic potential of soya bean--a pilot study.

Isolated platelet factor 3 (PF3) availability defect has been observed to be a common platelet functional disorder (PFD) in the Department of Haematology, All India Institute of Medical Sciences, New Delhi, India. One hundred and thirty-two patients were diagnosed to have this defect based on the presence of reduced PF3 availability, normal platelet aggregation with ADP, collagen, adrenaline, ristocetin, and arachidonic acid and normal PF3 content. PF3 availability was evaluated by measurement of Russel viper venom time (RVVT) on the patient's platelet-rich plasma (PRP) after incubation with ADP for 20 min. An RVVT value >19.0 s was considered diagnostic of reduced PF3 availability in patients with normal prothrombin and activated partial thromboplastin times. Isolated PF3 availability defect occurred in patients with ages between 2 and 65 yr and had a female preponderance (M:F=1:2). One fifth of the patients had a positive family history of similar mild bleeding diathesis, indicating an autosomal dominant pattern of inheritance. All patients presented with mild bleeding manifestations, the commonest symptom being appearance of recurrent ecchymotic spots. In females, menorrhagia was the commonest symptom. A pilot study was conducted on 45 patients to evaluate the therapeutic role of oral soya bean (50 g/d). The clinical response was evaluated after 3 months. Soya therapy resulted in disappearance of bleeding problems in 5 patients and reduction in frequency and severity of bleeding in 26 patients. A repeat PF3 availability test after 3 months of therapy showed complete correction in 4 and partial correction in 12 patients. It is evident from McNemer's test that both the clinical and the laboratory parameters (PF3 availability) showed a similar response to soya therapy (p>0.05). Pre-soya therapy mean PF3 availability values differ significantly from those after soya therapy (p<0.01). Thus, soya bean appears to have a therapeutic potential in isolated PF3 availability defect.

Adenosine Diphosphate↗
PubMed1999

Visceral leishmaniasis: an opportunistic infection in haematological malignancy.

Visceral leishmaniasis is a rare but potentially life threatening opportunistic protozoan infection in immunocompromised patients. The clinical manifestations in these patients are unusual and the diagnosis is difficult. They need prolonged treatment and are liable to have relapses. Here we report three patients with haematological malignancy (one with acute lymphoblastic leukaemia, one with chronic myeloid leukaemia, and one with myelodysplastic syndrome) complicated with visceral leishmaniasis. The clinical presentation, diagnosis, and outcome are discussed.

Adult↗
PubMed1998

Electrochemistry in microscopic domains. 1. The electrochemical cell and its voltammetric and amperometric response.

Microscopic aqueous sample droplets of nano- and picoliter volumes were formed on the bottom of a polystyrene dish under water-saturated heptane. The electrochemical cell consisted of a beveled carbon fiber microdisk working electrode and a reference electrode with a miniature junction, both inserted into the studied droplet. Both electrodes had a nominal tip diameter of 7.5 microns. Cyclic voltammetry and chronoamperometry in droplets of 3.3 mM ruthenium hexaammine trichloride in 0.1 M KCl solution were performed with this system. The experiments revealed for the first time major deviations in both voltammetric and amperometric microelectrode behavior in picoliter domains as compared to nanoliter volume and bulk solution. The concept and criteria of electrochemical microscopicity of volume is discussed. This work also provides a simple and robust experimental model system to verify electrochemical experiments in restricted domains such as in or near single biological cells or in microscopic tissue cavities. The methodology developed has, however, more general analytical and physicochemical applications as well.

Electrochemistry↗
PubMed1998

Differentiation of malignant and degenerative benign bone disease using Tc-99m MDP and Tc-99m citrate scintigraphy.

The authors present a prospective analysis of Tc-99m MDP and Tc-99m citrate scintigraphy in 108 patients with known malignant or degenerative benign bone disease. Of 108 patients, 59 (group A) had malignant bone disease. The other 49 patients (group B) had degenerative benign bone disease for which the results of Tc-99m MDP scans were positive. In both groups the Tc-99m citrate scan was performed 1 week after the Tc-99m MDP scan. The Tc-99m citrate/Tc-99m MDP lesion-to-background radioisotope uptake ratio (RUR) was calculated for each lesion 3 hours after radionuclide administration. The mean RUR for the malignant lesions was 1.0 +/- 0.484; for the benign lesions, the RUR was 0.29 +/- 0.250. Static imaging was also done for 10 lesions each from the malignant and benign groups at 1, 3, and 24 hours to study the kinetics of Tc-99m citrate. Time-activity curves for malignant lesions showed that the RUR remained high for 24 hours, whereas benign lesions showed a drastic decrease at 3 and 24 hours compared with the 1-hour images. The ratio of Tc-99m citrate to Tc-99m MDP is a promising parameter to differentiate malignant from benign degenerative lesions seen as areas of increased activity on Tc-99m MDP bone scans. The sensitivity and specificity of this technique were 97.8% and 95%, respectively.

Adult↗