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Biomedical subjects

P Abraham

Publications and source records attributed to P Abraham.

At least 55 records · Page 3Linked to original sources
PubMed2001

Generation of anti-(+)methamphetamine antibodies is not impeded by (+)methamphetamine administration during active immunization of rats.

The goal of these studies was to determine if chronic (+)methamphetamine ((+)METH) administration affects the production of anti-(+)METH antibodies during active immunization of rats. Active immunization for the treatment of chronic drug abuse has been proposed for drugs such as cocaine and nicotine. However, studies have not adequately addressed whether continual drug use during treatment would affect the development of an immune response. For the current studies, male Sprague-Dawley rats were immunized with either keyhole limpet hemocyanin (KLH; control group) or a (+)METH hapten ((+)METH with a six carbon spacer group at the para position of the ring structure)-KLH conjugate. The (+)METH-KLH animals were further divided into two groups. One group was immunized with no subsequent administration of (+)METH, while the other group was immunized and repeatedly challenged (twice a week throughout the study) with an i.p. dose of 3 mg/kg (+)METH. The results showed that the two groups of (+)METH-KLH immunized rats developed and maintained anti-(+)METH antibody titers. The anti-(+)METH immune responses of the two groups were not statistically different (P < 0.05) as measured by serum titers and the relative antibody affinities. These data suggest that repeated administration of (+)METH does not affect the generation of an anti-(+)METH antibody response in actively immunized rats.

Animals↗
PubMed2001

Hereditary thrombophilia as a cause of Budd-Chiari syndrome: a study from Western India.

The inherited deficiencies of protein C, protein S, antithrombin III, factor V Leiden mutation, prothrombin gene polymorphism, and antiphospholipids were studied in 53 Budd-Chiari syndrome (BCS) and 33 portal vein thrombosis (PVT) cases and compared with 223 age- and sex-matched controls. Protein C deficiency was detected in 7 (13.2%), protein S in 3 (5.7%), and antithrombin III in 2 (3.8%) of the BCS cases. Factor V Leiden was the most common risk factor, i.e., 14 of 53 (26.4%) in BCS cases followed by protein C, as compared with PVT cases, i.e., 2 of 33 (6.06%) and controls, i.e., 5 of 223 (2.3%). In PVT cases, protein C deficiency was present in 3 (9.09%), protein S deficiency in 1 (3.03%), and factor V Leiden mutation in 2 (6.06%) of the cases. The prothrombin gene polymorphism was not found in either the controls or the patients. The antiphospholipids were seen in 11 (20.75%) of the BCS cases and 6 (18.18%) of the PVT cases. Other acquired risk factors like pregnancy, surgery, and oral contraceptives were present in 8 (15.09%) of BCS and 3 (9.09%) of PVT cases. Thus overall, 59% of the BCS and 30% of the PVT cases could be explained by at least one of the etiologic factors studied.

Adolescent↗
PubMed2001

Pressure measurements at rest and after heavy exercise to detect moderate arterial lesions in athletes.

PURPOSE: This study defined how ankle arterial blood pressure measurements should be analyzed for the detection of moderate arterial disease (asymptomatic while walking). We used external iliac artery endofibrosis as a unique model of an isolated moderate arterial lesion, the role of which in exercise-related pain can be surgically proven. METHODS: Patients who were ambulatory in our institutional referral center were studied. Brachial pressures, ankle pressures, and heart rate were measured simultaneously on all four limbs at rest and after maximal exercise in 108 healthy athletes and 78 patients (among 89 athletes referred for suspicion of endofibrosis) with confirmed or excluded external iliac endofibrosis. For these 78 patients, we calculated systolic ankle pressure change, ankle/brachial index, and deviation from the ankle/brachial index to heart rate regression line (DAHR) that was defined in the 108 healthy athletes. RESULTS: In patients with endofibrosis, ankle/brachial index and ankle pressure were normal at rest. One minute after exercise, areas (mean +/- SE of area) under the receiver operating characteristics curve for the diagnosis of endofibrosis were 0.91 +/- 0.02, 0.91 +/- 0.03, 0.95 +/- 0.02, and 0.96 +/- 0.02 for ankle pressure, pressure change, ankle/brachial index, and DAHR, respectively. For all criteria, area decreased with time in the recovery period. CONCLUSION: After heavy-load exercise, the ankle/brachial index at minute 1 should be used rather than the systolic ankle pressure value or ankle pressure change as a means of improving the efficacy of the detection of endofibrosis in athletes. A 0.66 value of the index at minute 1 after maximal exercise seems an optimal cutoff point for clinical use, providing a 90% sensitivity rate and 87% specificity rate in the diagnosis of moderate arterial lesions. At rest and after 1 minute of recovery, the ankle/brachial index to heart rate relationship should be considered to be an efficient tool for analyzing the results of pressures measurements and improving detection efficiency.

Adult↗
PubMed2001

[Dual chamber rate responsive pacing and chronotropic insufficiency. Comparison of double and respiratory sensors].

Late responsive DDD pacemakers are the most technically advanced devices presently available. These pacemakers are particularly useful in patients with chronotropic insufficiency when the sinus node is incapable of accelerating during exercise. The latest pacemakers have two sensors to reproduce optimal physiological sinus acceleration. The aim of this study was to analyse the performances of a new rate responsive pacemaker with a double activity and respiratory sensor, the interaction of which is automatically controlled by a sophisticated algorithm, in 12 patients (8 men and 4 women) with a mean age of 75 +/- 7 years. Analysis was based on the performance of the sensors used singly or in association: during three exercise stress tests with measurement of the VO2 max; during everyday activities using the data archived by the pacemaker and the answers to a simplified questionnaire on quality of life. The results showed that during exercise stress testing with measurement of VO2 max, the best performances were obtained with the double sensor or the respiratory sensor compared with the activity sensor alone, suggesting that these two sensors are more effective in intense exercise. This tendency was also observed in the analysis of the memory bank of the pacemaker which showed that the total duration of the faster heart rates was greater with the two sensors. On the other hand, the quality of life was not significantly different, whichever sensor was studied. Longer scale trials are necessary to appreciate the real value of these new double sensor pacing devices and to identify the best indications for their usage.

Aged↗
PubMed2001

Malignancy of the larynx in a child.

Squamous cell carcinoma of the larynx in children is rare. The management of laryngeal malignancy is more difficult in children than adults for several reasons: the aggressive nature of a tumor that is often diagnosed late in children; the delicacy of pediatric anatomic structures; intraoperative blood loss; long-term post-treatment complications; and psychological factors particular to children. A tracheostomized 13-year-old boy came to us with a 4-month history of hoarseness, breathing difficulty, and swelling in the neck. A detailed examination revealed that a transglottic tumor had infiltrated the thyroid and cricoid cartilage, the upper two tracheal rings, and the thyroid gland. Such an infiltration has not been previously reported. The lesion proved to be a well-differentiated squamous cell carcinoma. We performed a wide-field total laryngectomy, which was followed by radiotherapy. Unfortunately, the child survived only 3 years postoperatively.

Adolescent↗
PubMed2001

Supraventricular tachycardia with hydrops in a 27-week premature baby.

A 27-week baby with antenatally diagnosed supraventricular tachycardia (SVT) and hydrops fetalis was delivered by emergency caesarean section because of severe fetal bradycardia. The mother was on flecanide to control the fetal SVT. The baby was hydropic at birth and required prolonged ventilatory support. On day 6, he developed acute renal failure for which peritoneal dialysis was done. On day 23, he developed several episodes of supraventricular tachycardia (SVT) which did not respond to intravenous adenosine and amiodarone and ultimately required intravenous flecanide. This case report highlights the management of a critically ill premature hydropic baby with resistant SVT, and the successful outcome.

Anti-Arrhythmia Agents↗
PubMed2001

A pilot study on the role of cytomegalovirus & human herpesvirus-6 infections in Indian bone marrow transplant recipients.

BACKGROUND & OBJECTIVES: Studies from Western transplant centers have shown the importance of cytomegalovirus (CMV) in infections among immunosuppressed post-transplant patients (both solid and bone marrow transplant recipients). Human herpesvirus-6 (HHV-6) infection is also important. Since such data are lacking from India, we carried out a pilot study to investigate the role of these two viruses in infections among Indian allogeneic bone marrow transplant (BMT) recipients. METHODS: A total of 21 BMT patients who developed acute graft versus host disease (GVHD), two patients who developed chronic GVHD, and eight recipients who did not develop GVHD but had skin rash/elevated liver enzymes, persistent cytopaenia or interstitial pneumonitis with a high clinical suspicion of possible CMV association were studied for markers of CMV and HHV-6 infections. RESULTS: CMV DNAemia was documented in 9 (42.8%) and CMV IgM in 4(19%) of the 21 patients with acute GVHD. HHV-6 DNAemia was not seen in any patient with acute GVHD but 2 (9.5%) had HHV-6 IgM. Of the 2 patients with chronic GVHD, 1 was positive for CMV DNA and IgM, and both were negative for HHV-6 markers. The lower incidence of CMV DNAemia in our recipients may be attributable to the presence of neutralizing antibody (anti gB/AD-1) among the 17 CMV and HHV-6 DNAemia negative recipients, 4(23.5%) had neutralizing antibodies (S/N ratio > or = 5). Of the 13 CMV DNAemia positive recipients, only one (7.7%) was positive for neutralizing antibodies. Among the 5 neutralizing antibody (S/N ratio > or = 5) positive recipients, 4 (80%) were negative for CMV DNAemia. The one nPCR positive was revealed only at high DNA (> 0.1 microgram) input indicating low CMV signal strength. INTERPRETATION & CONCLUSION: The present study shows the use of DNAemia in detecting CMV infections among BMT recipients. All recipients had high avidity CMV IgG (AI > 50%) confirming CMV reactivation or reinfection in these patients. There was evidence from this study suggesting that neutralizing antibodies may play a role in controlling CMV reactivation. We found no significant HHV-6 association with GVHD in Indian allogeneic BMT recipients.

Adolescent↗
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↗
PubMed2001

Evaluation of an indigenously manufactured rapid immunochromatographic test for detection of HBsAg.

A 'rapid' one step immunochromatographic, visually read, antigen capture assay--the "HEPACARD" (J Mitra & Co. Ltd., New Delhi, India) used for rapid screening of HBsAg was evaluated. Thousand consecutive sera sent to our laboratory for the purpose of HBsAg screening were tested by this device and by a third generation enzyme immunoassay (EIA) (Auszyme Monoclonal, Abbott Laboratories, Chicago, Illinois) or an automated Axsym microparticle enzyme immunoassay (MEIA) (Axsym HBsAg V2, Abbott Laboratories, Abbott Park, Chicago, Illinois, ISA). Hepacard showed a sensitivity of 79% (CU: 57.3-92%) and specificity of 98.9% (CI: 97.9-99.4%) when compared to the findings by the third generation EIA assays. This study suggested that this particular rapid HBsAg test results have to be confirmed by either an EIA or MEIA where the facility exists. The test may be used only in a small hospital setting where the facilities for enzyme immuno assays do not exist.

Antibodies, Monoclonal↗
PubMed2000

3alpha-(4-Substituted phenyl)nortropane-2beta-carboxylic acid methyl esters show selective binding at the norepinephrine transporter.

A series of 3alpha-(4-substituted)nortropane-2beta-carboxylic acid methyl esters was synthesized and evaluated for the ability to inhibit radioligand binding at the dopamine, serotonin, and norepinephrine transporters. 3alpha-(4-Methylphenyl)nortropane-2beta-carboxylic acid methyl ester (4c) was found to be selective and highly potent for the norepinephrine transporter (NET) relative to the dopamine and serotonin transporters.

Carboxylic Acids↗
PubMed2000

Glucagon-like peptide 2: a new treatment for chemotherapy-induced enteritis.

BACKGROUND: Glucagon-like peptide 2 (GLP-2) is a recently identified intestinal epithelium-specific growth factor that has been shown to reduce the severity of inflammatory disorders of the intestine in rodent models. We hypothesized that GLP-2 administration would be beneficial in chemotherapy-induced enteritis either by preventing injury or by promoting recovery. MATERIAL AND METHODS: Rats received no drug (control), chemotherapy alone [5-fluorouracil (5-FU), 190 mg/kg, ip] (Chemo), 5-FU followed by 3 days of GLP-2 analog (ALX-0600, 0.1 microg, sc twice daily) (CH-G), or GLP-2 analog for 6 days prior to 5-FU and for 3 days afterward (G-CH-G). Animals were pair fed. Rats received 5-bromo-2-deoxyuridine (Br-dU, 50 mg/kg, 2.5 h prior to sacrifice on Day 3 postchemotherapy) for immunohistochemical assessment of cellular proliferation. RESULTS: Chemotherapy induced significant reductions in body weight, villus height, and crypt depth compared with controls. Intestinal wet weight, villus height, and crypt depth were significantly higher for the CH-G group compared with the Chemo group. The CH-G group also showed a significant improvement in villus height compared with the G-CH-G group. Crypt depth, but not jejunal wet weight or villus height, was significantly improved in the G-CH-G group compared with the Chemo group. The percentage of Br-dU-labeled cells in the intestinal crypts did not differ among the groups. CONCLUSIONS: These results suggest, for the first time, that GLP-2 treatment initiated after chemotherapy administration enhances intestinal recovery. In contrast, GLP-2 treatment initiated prior to chemotherapy administration to prevent injury has less beneficial effect. GLP-2 administration may be beneficial to patients suffering from chemotherapy-induced enteritis.

Animals↗
PubMed2000

Comparison of time-frequency estimators for peripheral embolus detection.

Recently, a time-frequency processing of peripheral arterial Doppler signals, based on the spectrogram, was proposed to detect automatically high-intensity transient signal. Three time-frequency representations, the smooth-pseudo-Wigner-Ville, the Choï-Williams and the cone-kernel distributions were compared with the spectrogram, following the detection scheme previously reported. The results showed that the spectrogram provided the best compromises between false-detection and no-detection compared with the other time-frequency representations.

Embolism↗