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Biomedical subjects

P P Thomas

Publications and source records attributed to P P Thomas.

At least 19 recordsLinked to original sources
PubMed2003

Testing switchability of a new microemulsion formulation of cyclosporine.

We assessed the bioavailability of cyclosporine (CyA) in the test formulation (Cap Arpimune ME) relative to the reference formulation (Cap Sandimmune Neoral) to ascertain the switchability between the two formulations in patients. The study population included 30 patients on maintenance hemodialysis awaiting renal transplantation. The study adopted a randomized open-label, two-way, two-period, two-sequence crossover design. The dose administered was 8 mg/kg/d in two divided doses for 5 days in each study period with a washout period of 1 week between the two periods. A five-point blood sampling (at 0, 1, 2, 3, and 4 hours postdose) was done on the last day of each study period for CyA level monitoring. The study measures included C(max) (maximum blood concentration), AUC (area under the blood CyA concentration versus time curve, 0 to 4 hours) and actual time concentrations at individual sampling times. The differences in mean values for all parameters and the least significant differences were less than 20% of reference mean. Assessment of bioequivalence using log-transformed data showed that the point estimate (ratio test: reference) for C(max) was 0.9717 with a 90% confidence interval (CI) of 0.88 to 1.06 and that for AUC was 1.0053 with a 90% CI of 0.90 to 1.12. The bioequivalence obtained suggests that the test formulation can replace the reference formulation in patients who require CyA therapy.

Area Under Curve↗
PubMed2003

Pre- and postrenal transplantation pharmacokinetics of cyclosporine microemulsion.

UNLABELLED: The availability of a microemulsion formulation (ME) of cyclosporin (CyA) displays improved bioavailability and reduced inter and intra-patient variability, resulting in improved long-term outcomes. Recent developments in therapeutic drug monitoring stress the need to optimize peak drug levels during the early posttransplant period to obtain long-term benefit. METHODS: We studied early CyA-ME pharmacokinetics, comparing pre- versus immediate posttransplant values, to assess predictability of pre-transplant profiles in 22 patients including 3 diabetics. An 8 mg/kg per day amount in two divided doses was administered, for 5 days pretransplant and 10-14 days posttransplant before performing the pharmacokinetic studies. Drugs interacting with CyA metabolism/absorption were withdrawn and patients with liver disease were excluded the CyA level monitoring used a 5-point blood sampling (at 0 hours, 1 hours, 2 hours, 3 hours, and 4 hours post-dose). The study compared actual concentrations at each individual time and the limited 0-4 hour AUC. RESULTS: The paired values at each point pre- and posttransplant were: C0 = 171 +/- 63 and 215 +/- 112, C1 = 723.86 +/- 345 and 1239.95 +/- 415, C2 = 972 +/- 185 and 1249.95 +/- 336, C3 = 822 +/- 242 and 942.7 +/- 286, and C4 = 601.54 +/- 190 and 670.5 +/- 208 ng/mL respectively. The C1 and C2 values were significantly higher posttransplant (P =.008 and 0.0045 respectively), suggesting a steeper absorption phase, a conclusion consistent with the higher 0-4 hour AUC posttransplant (P =.0089). However, linear regression analysis of pre- versus posttransplant values showed poor correlations. CONCLUSIONS: CyA absorption is significantly lower among patients on maintenance hemodialysis and showed no predictive correlation with posttransplant levels. The possible role of uremia in retarding absorption which may have clinical significance for primary graft dysfunction, needs further evaluation.

Biological Availability↗
PubMed2002

Problems of classification of Henoch Schonlein purpura: an Indian perspective.

A 2-year prospective study was carried out in which 71 patients with primary cutaneous vasculitis were classified using the American College of Rheumatology (ACR) classification and the Chapel Hill Consensus Conference (CHCC) recommendations for Henoch Schonlein purpura (HSP). The sensitivity of the ACR criteria was 64.8% and that of the CHCC definition 31%. When the ACR criteria were combined with results of direct immunofluorescence (DIF) the sensitivity was 78.9%. The concordance between the two systems was low as only 12 patients fulfilled criteria for both classifications. Although the ACR criteria were found to be more useful in the classification of HSP our data suggest that they need to be modified to include adults with disease. The age at onset of disease was higher than that in the west. Seventy per cent of patients identified by either classification were > 20 years of age. The prevalence of gut involvement, microhaematuria and proteinuria was < 25% in both groups. The sensitivity of histopathology on the other hand was 80.4% and was not influenced by the duration of the lesion. The DIF test was a useful adjunct to histopathology if it was done within 48 h as the yield of a positive test was significantly higher in this group as compared to the patients who had the test done later.

Adolescent↗
PubMed2001

Risk factors for post-transplant tuberculosis.

BACKGROUND: Post-transplant tuberculosis (post-TxTB) occurs in 12 to 20% of patients in India and results in the death of 20 to 25% of those patients. Prospective studies on post-TxTB are few. METHODS: Renal allograft recipients were studied prospectively for 3.1 (0 to 13.9) median (range) years for incidence, manifestations, risk factors, and prognosis for post-TxTB. Kaplan-Meier analysis was used to study the survival rates. The extended Cox proportional model for time-dependent covariates was used to measure the risk factors when the hazard was nonuniform. RESULTS: Of the 1414 patients considered for inclusion, multiple-transplant subjects (N = 37) and patients who developed pre-transplant TB (pre-TxTB; N = 126) were excluded from the study. The prevalence of post-TxTB was 13.3% (N = 166). The risk of post-TxTB when on cyclosporine (CsA) therapy was 2.5 (P = 0.0311) and 1.9 (P = 0.0430) times at < or =6 and < or =12 months, respectively, compared with patients on prednisolone plus azathioprine (PRED + AZA). The risk of post-TxTB in the presence of diabetes mellitus, chronic liver disease, and other co-existing infections [including deep mycoses, cytomegalovirus (CMV), Pneumocystis carinii pneumonia (PCP), nocardia] was 2.2 (P = 0.0011), 1.7 (P = 0.0010) and 2.4 (P < 0.0001) times, respectively. Of the 166 patients with post-TxTB, 53 patients died, and of those deaths, 17 (32%) were due to post-TxTB; 11 (65%) of the 17 had co-existing infections. The factors associated with death were HLA mismatches, PRED + AZA immunosuppression, pre- and post-TxTB, diabetes mellitus, post-transplant diabetes (PTDM), and other co-existing infections. The extended Cox model for death as the outcome variable showed the following to be significant risk factors: post-TxTB> 2 years (P = 0.0036), chronic liver disease> 6 years (P = 0.0457), PTDM> 5 years (P = 0.0729), diabetes mellitus (P = 0.0091), human lymphocyte antigen match < or =1 antigen (P = 0.0134), two to three antigens (P = 0.0448), and the presence of other co-existing infections (P < 0.0001). CONCLUSIONS: Cyclosporine therapy is associated with early post-TxTB. Diabetes mellitus and chronic liver disease are risk factors for post-TxTB. The occurrence of both pre-TxTB and post-TxTB (>2 years) along with hyperglycemia, liver disease, and other co-existing infections are important risk factors for death.

Adult↗
PubMed2001

Characterization of antibody response to human cytomegalovirus in Indian renal transplant patients.

BACKGROUND & OBJECTIVES: Cytomegalovirus (CMV) disease in seroendemic transplant populations is due to reactivation of the virus, or reinfection. In this context, the antibody response is likely to influence presentation, clinical severity and outcome of the disease, and may provide a diagnostic and prognostic marker. This study was carried out in Indian renal transplant patients and healthy adults to characterize the antibody response to cytomegalovirus. METHODS: Thirty three transplant recipients with CMV illness (symptomatology with IgM and/or nPCR positive status), 20 recipients who were asymptomatic in the 6 months of follow up after transplantation and 62 healthy controls were investigated for markers of CMV infection. These individuals were tested for IgG avidity and neutralizing antibody by ELISA techniques. RESULTS: All 53 transplant recipients were found to have an IgG avidity index of > 50 per cent. Antibody to a CMV envelope glycoprotein gB/AD-1 (putative neutralizing antibody) was expressed as S/N ratio and was > or = 5 in asymptomatic (65%) and symptomatic (27%) immunosuppressed renal transplant recipients. However, none of the 53 CMV IgG positive healthy controls were positive for neutralizing antibodies S/N ratio > or = 5 (S/N ratio = sample mean OD/mean OD of 3 negative controls in each run). We observed the simultaneous presence of CMV PCR signal in leukocytes and neutralizing antibody (S/N ratio > or = 5) in the plasma in 22 (41.5%) of the 53 renal transplant recipients. INTERPRETATION & CONCLUSIONS: In this study among the immunosuppressed transplant patients we observed an association between symptomatic disease and the relative absence of neutralizing antibodies. The neutralizing antibodies are less frequently demonstrable among controls; while appearance in a higher proportion of asymptomatic recipients especially in association with high IgG avidity (> 90%) is suggestive of its role in control of CMV disease despite reactivation as evidenced by DNAemia while on immunosuppressive therapy.

Adult↗
PubMed2000

Management and outcome of brain abscess in renal transplant recipients.

Although infection is the commonest central nervous system complication following renal transplantation, brain abscess is uncommon. Over the last 11 years, five renal transplant recipients who had brain abscesses were treated by computed tomography (CT)-guided stereotactic aspiration. Three patients had a fungal abscess, one a tuberculous abscess and the other had a methicillin-resistant Staphylococcus aureus abscess. One patient required a craniotomy for the excision of a fungal abscess which was persistent after two CT-guided stereotactic aspirations. The survivors in this group are the patient with a tuberculous abscess who is alive and well 5 years after diagnosis, and another with a dematiaceous fungal abscess (phaeohyphomycosis). CT-guided stereotactic surgery is minimally invasive, and can safely be performed in these patients. It often leads to an aetiological diagnosis in renal transplant recipients with brain abscesses. Specific antibiotic management directed towards the causative organism rather than empirical treatment can be instituted following the procedure. Although the ultimate prognosis in these patients is bleak even with specific antibiotic therapy, an occasional patient might have a good outcome with prompt and appropriate therapy.

Adult↗
PubMed2000

Cytomegalovirus infection in a seroendemic renal transplant population: a longitudinal study of virological markers.

BACKGROUND/AIMS: The detection of viremia by polymerase chain reaction (PCR) in cytomegalovirus (CMV) infection in renal allograft recipients has been shown to have a predictive value for disease. However, its diagnostic utility in a population with high background seropositivity has not been defined. This prospective study was undertaken to assess the relationship of CMV DNAemia, and/or IgM seropositivity to CMV disease in a seroendemic transplant population. METHODS: Consecutive patients undergoing renal transplantation between August 1997 and February 1998 were enrolled. Blood was sampled before transplantation from the donors and recipients for CMV serology and nested PCR for CMV DNA, and after transplantation from the recipients only at monthly intervals until 6 months. Patients were observed for the development of any CMV-like illness during follow-up. CMV DNA was quantitated using limiting dilution PCR on samples obtained from symptomatic patients at the time of illness and from asymptomatic patients at the end of their 6-month follow-up. RESULTS: A total of 57 recipient-donor pairs were recruited. Immunosuppression was cyclosporine-based in 55 of 57 (95. 6%). The CMV serologic status was D+R+ in 55 of 57 and D+R- in 2 of 57 pairs. PCR positivity indicating viremia increased from 5% before transplantation to 95% at 6 months after transplantation. Similarly IgM positivity reached 80% at 3 months and thereafter; positivity for any marker was 100% by 6 months. Viremia was sustained in over half the patients. The incidence of CMV-attributable disease peaked at 3 months, and was predominantly mild and self-limiting. Tissue-invasive disease appeared later in 4 patients (7%). Asymptomatic viremia was seen in 60-70% of patients at each sampling point. The positive predictive value (PPV) of PCR positivity for disease was 35-40%, and the negative predictive value (NPV), 90-100%. However, the high NPV was of use only in the early post-transplant period, negativity for markers declining rapidly with time. Quantitative assay showed significantly higher levels of CMV DNA in symptomatic patients (p = 0.01). A cutoff of 0.001 microg had a specificity of 95% and a PPV of 92.3% for symptomatic CMV disease. CONCLUSION: Qualitative tests to detect CMV DNAemia and IgM, although useful markers of viremia and active infection, have limited utility for the diagnosis of disease in a seroendemic transplant population. Quantitation of CMV DNAemia may play an important role in diagnosis in such a setting.

Adolescent↗
PubMed2000

Role of molecular techniques in the detection of HBV DNA & HCV RNA among renal transplant recipients in India.

In this study we have investigated the occurrence of hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV) infections among 68 renal transplant recipients. Replicative HBV and replicative HCV infections were seen in 12 (17.6%) and 38 (55.9%) patients respectively, the difference was statistically significant (P < 0.001). Among the 38 HCV RNA+ individuals, anti-HCV was present only in 23. Anti-HCV in the absence of HCV RNA was detected in one patient. Anti-HDV antibody was seen in 2 (15.4%) of the 13 HBV infected individuals. Nine (13.2%) of the 68 individuals had replicative dual infection with HBV and HCV. Triple infection (HBV DNA+, HCV RNA+, anti-HDV+) was seen in 2 transplant recipients. There was significantly higher demonstration of replicative HCV (P < 0.001) in transplant recipients having elevated liver enzymes (n = 34) as compared to transplant recipients having normal liver enzyme levels (n = 34). Though not significant, a higher detection rate was also seen with replicative HBV infection and replicative dual infection among transplant recipients with elevated liver enzymes. The higher detection of HCV in renal transplant recipients by molecular techniques, emphasizes the need for HCV RNA testing. Further deliberate attempts to change practices to reduce this problem may also improve graft and patient survival in recipients.

Adolescent↗
PubMed2000

A randomised controlled trial of intradermal hepatitis B vaccination and augmentation of response with erythropoietin.

AIM: Intradermal administration of Hepatitis B vaccine (HBV) achieves better seroconversion in patients on dialysis compared to intramuscular administration. The aim of the study was to determine whether twice weekly intradermal injections of the vaccine can further augment the vaccine response as compared to once weekly injections. Patients with end stage renal failure on haemodialysis were randomly allocated over a period of 22 months to receive 20 mu gms of recombinant HBV by intradermal injections once a week (group 1) or twice a week (group 2) for 6 weeks. The patients recruited during the first 12 months of the study did not receive recombinant human erythropoietin (Epo) as it was not available (phase 1). During the last 10 months of study all patients received Epo (phase 2) in addition to HBV. RESULTS: A total of 85 patients were enrolled of whom 77 completed the study. There were 41 patients in group 1 and 36 patients in group 2. Seroprotection (anti HBs > 10 mIU/ml in the absence of HBs Ag and anti HBc) was achieved in 56.1% patients of group I compared to 77.8% of group 2 (p < 0.05). The seroprotection rate was 78.1% among patients receiving Epo (phase 2) compared to 60% among 45 who did not receive Epo (phase 1). Anti HBs titre in responders was 308.5 +/- 148.7 mIU/ml in patients of phase 2 compared to 198 +/- 112.8 mIU/ml in patients of phase 1 (p < 0.05). The subgroup receiving both Epo and twice weekly vaccine (group 2 of phase 2) had the highest seroprotection rate of 86.7%. CONCLUSION: Twice weekly intradermal vaccination is more effective than once weekly regime in achieving rapid seroconversion. The vaccine response may be augmented by use of Epo probably due to reduction in transfusion requirement and concomitant immunosuppression.

Adolescent↗
PubMed1999

Prognostic factors in diffuse proliferative lupus nephritis.

BACKGROUND: Patients with diffuse proliferative lupus nephritis (DPLN) can have variable clinical course. Identification of the predictors of outcome would help to improve the management. We have studied the prognostic significance of clinical, laboratory and histological parameters in patients with DPLN. METHODS: Twenty nine patients diagnosed to be having DPLN seen between 1987 and 1991 were followed up for over 57 months. Parameters assessed for prognostic significance included serum creatinine, urine protein at the time of biopsy, blood pressure, type of immunosuppression, composite scores and individual components of activity index (AI) and chronicity index (CI). Kaplan-Meier survival curves were plotted and the results were compared using log rank test. Fishers' exact test was used to study the risk factors. RESULTS: End stage renal failure developed in 7/29 (24.1%) patients; 7/19 (36.8%) who had hypertension and 7/16 (43.8%) who had nephrotic proteinuria developed renal failure, while none who had normal blood pressure or nonnephrotic proteinuria, developed renal failure (p < 0.01). Three patients had high activity index (> 12) and all three developed renal failure. Other parameters such as age, gender, serum creatinine, type of immunosuppression, CI and individual components of AI failed to predict the outcome (p > 0.05). CONCLUSION: Hypertension, nephrotic proteinuria and high AI were predictive of progression to end stage renal failure in patients with diffuse proliferative lupus nephritis.

Adolescent↗
PubMed1998

Vaccine-induced necrobiotic granuloma.

We report two cases of necrobiotic palisaded granulomas which developed at the site of intradermal hepatitis B vaccination. To the best of our knowledge, this kind of reaction has not been reported previously.

Adolescent↗
PubMed1998

Leprosy and renal transplantation.

Nine cases of leprosy in patients treated at a large renal transplant centre in South Asia are described. Three had leprosy diagnosed before transplantation and had either completed or were continuing chemotherapy at the time of transplantation. One showed exacerbation of undisclosed leprosy after transplantation. Five patients developed the disease for the first time 22 months to 12 years after transplantation. Immunosuppression did not adversely affect the treatment of leprosy in any of the patients though concurrent liver disease required cessation of rifampicin in one patient.

Adult↗
PubMed1997

Association between endometriosis, dysplastic naevi and history of melanoma in women of reproductive age.

Women with melanoma and its precursor lesions, dysplastic naevi, have a higher prevalence of reproductive disorders than women without melanotic lesions. This association appears strongest among young women with dysplastic naevi and endometriosis. The purpose of this study was to evaluate patients with laparoscopy-confirmed endometriosis for the presence of dysplastic naevi. A total of 66 endometriosis patients and 35 controls completed a detailed questionnaire and underwent an extensive dermatological examination for the presence of dysplastic naevi. In all, 41% of patients aged < or = 32 years had dysplastic naevi, compared with 8% of controls (P = 0.038). In addition, 29% of patients with endometriosis reported a family history of melanoma compared with 10% of controls (P = 0.039). This study demonstrated an association between endometriosis and dysplastic naevi in younger women of reproductive age and found an associated family history of melanoma among endometriosis patients. These observations may be useful in the evaluation and care of young women by both gynaecologists and dermatologists.

Adult↗
PubMed1996

Use of a second-generation CA125 assay in gynecologic patients.

OBJECTIVE: To determine the correlation between the widely used CA125 assay and a second-generation assay, CA125 II, in a large population of women to determine the utility of measuring CA125 levels in the diagnosis of benign gynecologic disease. METHODS: A total of 822 patients who presented to a gynecology clinic completed a medical questionnaire and underwent a physical examination. Blood samples were obtained to determine serum CA125 levels. Hospital charts were reviewed, and diagnoses were correlated with serum CA125 levels as measured by the CA125 and CA125 II assays. RESULTS: CA125 and CA125 II assay values were highly correlated within four subject categories: age, ethnicity, smoking history, and menstrual category. Mean values decreased with increasing age but were unchanged across ethnic groups and cigarette-smoking status. When means were compared for results of the second-generation and current assays, little difference was found in the age, ethnicity, and smoking categories. Mean serum CA125 values on the CA125 II assay exceeded those on the CA125 assay when obtained during the menstrual and follicular/luteal phases of the menstrual cycle, but they did not differ in anovulatory, pregnant, and menopausal women or in those patients taking hormonal medications. CA125 levels were elevated on both assays in women with fibroids and were higher on the CA125 II assay than on the CA125 assay in women with benign ovarian cysts. CONCLUSIONS: Serum CA125 levels obtained using the CA125 II assay are closely correlated with those obtained using the more familiar CA125 assay. In the diagnosis of benign gynecologic disease, the usefulness of a single serum level measured with the newer CA125 II assay was the same as that of a single CA125 assay level.

Biomarkers↗
PubMed1996

Dexamethasone during ovulation induction for in-vitro fertilization: a pilot study.

The purpose of the present study was to determine whether adrenal androgen suppression with dexamethasone (DEX) during ovulation induction improves the outcome of in-vitro fertilization (IVF) cycles. A total of 25 patients with serum dehydroepiandrosterone sulphate (DHEAS) concentrations > 2.5 micrograms/ml were randomized to receive either 0.5 mg DEX daily or placebo during ovulation induction with leuprolide acetate down-regulation plus human menopausal gonadotrophins (HMG). Nine patients undergoing a subsequent IVF cycle were crossed over to the other treatment group. Ovarian responsiveness and IVF outcome variables analysed included number of follicles > 12 mm in diameter, serum oestradiol concentrations on the day of human chorionic gonadotrophin (HCG) administration, number of ampoules of HMG administered, number of oocytes retrieved, percentage of oocytes fertilized, number of embryos transferred, implantation rate and numbers of clinical pregnancies and live birth pregnancies. The 31 randomized IVF cycles revealed a trend towards a higher implantation rate for the placebo-treated group compared to the DEX-treated group (24 versus 10%; P = 0.07). The remainder of the IVF cycle variables revealed no statistically significant differences. In conclusion, the suppression of adrenal androgens with DEX in women with DHEAS concentrations > 2.5 micrograms/ml appears to have no beneficial effects on ovarian responsiveness or clinical or live birth pregnancy rates.

Adult↗
PubMed1995

Does low-dose combination oral contraceptive use affect uterine size or menstrual flow in premenopausal women with leiomyomas?

OBJECTIVE: To assess whether low-dose oral contraceptive (OC) use affects uterine size or menstrual flow in women with leiomyomas. METHODS: Eighty-seven premenopausal women with leiomyomas were enrolled in a 1-year study. Fifty-five women took low-dose monophasic OCs, and 32 took no OCs or other hormonally active medications. Uterine size was assessed by bimanual and sonographic examinations before and after the study. Duration of menstrual flow and hematocrit were also assessed. RESULTS: Fifty (91%) of 55 women completed 1 year of OC use. There was no significant difference in mean uterine size determined by bimanual examination or in uterine volume measured by sonography after 12 months of OC use. Likewise, there were no significant changes in these indices among the 32 women who did not take OCs. The mean duration of menstrual flow decreased significantly, from 5.8 to 4.4 days (P < .01), in the group of women taking OCs. The mean hematocrit increased significantly, from 35.8 to 37.8% (P = .014), in this group. In contrast, the women who did not take OCs had no significant changes in these indices. CONCLUSION: In most women with leiomyomas, low-dose OC use provides the noncontraceptive benefit of a reduction in the duration of menstrual flow, with resultant improvement in hematocrit, without increasing uterine size.

Adult↗