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Biomedical subjects

S Shenoy

Publications and source records attributed to S Shenoy.

At least 37 records · Page 2Linked to original sources

Synthesis of some new biologically active bis-(thiadiazolotriazines) and bis-(thiadiazolotriazinyl) alkanes.

4-Amino-3-mercapto-1,2,4-triazin-5(4H)-ones (1) were condensed with dicarboxylic acids 2 to yield bis-(4-oxo-4H-1,3,4-thiadiazolo[2,3-c]-1,2,4-triazin-7-yl)alkanes (3b-d,f-h,j-l,n-p) and bis-thiadiazolotriazines (3a,e,i,m). All the newly synthesised compounds were characterised by analytical, IR, NMR and mass spectral studies. Some of the newly synthesised compounds were screened for their antibacterial and antifungal properties. Among the tested compounds, compound 7,7'-(1,4-butanediyl)-his-(3-t-butyl-4-oxo-4H-1,3,4-thia-diazolo[2,3-c]-1,2,4-triazine (3p) exhibited highest degree of antifungal activity.

Alkanes↗

The Barnes-Jewish Hospital/Washington University Renal Transplant Program: comparison of two eras 1991-1994 and 1995-2000.

The first cadaveric transplant at Barnes-Jewish Hospital/Washington University was performed in 1963, the first living related transplant in 1965, and the first living unrelated transplant in 1983. Changes in the renal transplant program initiated in 1993 and 1994 resulted in many improvements over the past decade. Our comparison of 2 modern eras of transplant, 1991-1994 and 1995-2000, showed the following: 1. No significant differences in patient and donor characteristics. 2. Trends toward greater use of living donors (p = 0.07), older cadaveric donors (p = 0.084) and particularly cadaveric donors > 55 years of age (p = 0.09). 3. Decreasing mean CIT: 19.2 hours vs. 14.2 hours (p < 0.001). 4. Decreasing use of donors with CIT > 24 hours: 22% to 3%, (p < 0.001). 5. Decreased rate of DGF: 13% vs. 8% (p = 0.044). 6. Decreased rate of symptomatic CMV: 35% vs. 14% (p < 0.001). 7. Decreased rate of PTLD: 3.5% vs. 0.5% (p = 0.004). 8. Decreased one-year rate of acute rejection: 41% vs. 15% (p < 0.001). 9. Current one-year rate of acute rejection < 8%. 10. Decreased length of initial hospital stay: 12.7 days to 8.0 days (p < 0.001). 11. Decreased length of hospital in the first year after transplant: 10.6 days vs. 6.4 days (p < 0.001). 12. There were no improvements in patient and graft survival at one and 3 years. a. one-year patient survival rates: 95% vs. 96%. b. 3-year patient survival rates: 90% vs. 90%. c. one-year death-censored graft survival rates: 91% vs. 94%. d. 3-year death-censored graft survival rates: 87% vs. 88%.

Academic Medical Centers↗

Effect of leukocyte compatibility on neutrophil increment after transfusion of granulocyte colony-stimulating factor-mobilized prophylactic granulocyte transfusions and on clinical outcomes after stem cell transplantation.

The primary limitations of granulocyte transfusions include low component cell dose and leukocyte incompatibility. Component cell dose improved with granulocyte colony-stimulating factor (G-CSF) mobilization, and the transfusion of G-CSF-mobilized, human leukocyte antigen (HLA)-matched granulocyte components resulted in significant, sustained absolute neutrophil count (ANC) increments. However, the effect of leukocyte compatibility on outcomes with G-CSF-mobilized granulocyte transfusions is unclear. The objectives were to determine the effect of leukocyte compatibility on ANC increments and selected clinical outcomes after transfusion of prophylactic, G-CSF-mobilized granulocyte components into neutropenic recipients of autologous peripheral blood stem cell (PBSC) transplants. Beginning on transplant day 2, 23 evaluable recipients were scheduled to receive 4 alternate-day transfusions of granulocyte components apheresed from a single donor given G-CSF. G-CSF was also given to recipients after transplantation. Recipient ANC was determined before and sequentially after each granulocyte transfusion to determine the peak ANC increment. Leukocyte compatibility was determined at study entry only by a lymphocytotoxicity screening assay (s-LCA) against a panel of HLA-defined cells. Eight recipients had positive s-LCA. On days 2 and 4, the mean peak ANC increments after granulocyte transfusion were comparable between the cohorts with positive and negative s-LCA. However, the mean peak ANC increments on day 6 (246/microL vs 724/microL; P =.05) and day 8 (283/microL vs 1079/microL; P =.06) were lower in the cohort with positive s-LCA, in spite of the transfusion of comparable component cell doses. Adverse reactions occurred with only 5 of 87 (5.7%) granulocyte transfusions and were not associated with leukocyte compatibility test results. Platelet increments, determined 1 hour after granulocyte transfusion, were comparable between the cohorts. Although the 2 cohorts received PBSC components with similar CD34(+) cell doses, the cohort with a positive s-LCA had delayed neutrophil engraftment and a greater number of febrile days and required more days of intravenous antibiotics and platelet transfusions. Leukocyte incompatibility adversely affected ANC increments after the transfusion of G-CSF-mobilized granulocyte components and clinical outcomes after PBSC transplantation.

ABO Blood-Group System↗

Value of superficial cultures in diagnosing neonatal sepsis.

This study was conducted to determine the value of superficial cultures in the diagnosis of neonatal sepsis in our hospital. Sixty three babies, younger than 2 weeks who were admitted with suspected sepsis were investigated. A total of 369 cultures were obtained from these babies--252 (68.29%) superficial and 171 (31.70%) deep cultures. External ear canal swab, umbilical cord swab and throat swab culture accounted for the superficial cultures. Blood culture, cerebrospinal fluid culture and i.v. catheter culture accounted for deep cultures. Of the 369 cultures, 225 (60.97%) were positive for pathogens, which included Staphylococcus aureus, Klebsiella sp, Escherichia coli, Group B streptococcus and Enterococcus fecalis. The yield of pathogenic organisms was higher for superficial cultures (53.84%). All superficial cultures obtained during the study on each patient were simultaneously compared with the deep cultures by antimicrobial sensitivity method. The overall comparison showed that the practice of superficial cultures could be useful to predict the pathogenic organisms causing invasive disease.

Bacteria↗

Synthesis and antibacterial studies of a new series of 1,2-bis(1,3, 4-oxadiazol-2-yl)ethanes and 1,2-bis(4-amino-1,2, 4-triazol-3-yl)ethanes.

The acylhydrazones 3, obtained by the treatment of succinic acid dihydrazide 2 with furfural, nitrofurfuraldehydediacetate and substituted arylfurfurals, on oxidative cyclization with bromine in acetic acid yielded 1,2-bis(1,3,4-oxadiazol-2-yl)ethanes 4 which are further converted into 1,2-bis(4-amino-1,2,4-triazol-3-yl)ethanes 5 with hydrazine hydrate. The newly synthesised compounds are characterised by analytical, IR, NMR and mass spectral data. Most of the newly synthesised compounds have been found to be active against both Gram positive and Gram negative bacteria at less than 6 microg/mL concentration.

Anti-Bacterial Agents↗

Allogeneic peripheral blood stem cell transplantation following CD34+ enrichment by density gradient separation.

GVHD is a significant cause of morbidity and mortality following allogeneic peripheral blood stem cell transplantation (AlloPBSC). CD34+ cell selection could reduce GVHD by negative selection of T cells. In an attempt to reduce the T cell content of alloPBSC we carried out a trial in which 11 patients with hematologic malignancies received alloPBSC from HLA-matched siblings following density gradient separation using an isotonic colloidal silica solution (BDS 60; Dendreon Corporation). Cyclosporine and methylprednisone were used for GVHD prophylaxis. The mean yield of CD34+ cells was 69 +/- 15.6% with a purity of 2.9 +/- 1.7%. The mean number of CD3+ cells infused was 1.0 +/- 1.2 x 107/kg, representing a 1.3 log depletion. A high risk of acute GVHD was observed: grade II-IV in 7/11 (64%) and grade III-IV GVHD in 5/11 (45%) patients. Nine of the 11 (82%) patients died with a median survival of 68 days. Cytokine expression in PBSC was compared pre and post processing. Interferon-gamma was detected only following density gradient separation while IL-8 expression increased 3- to 6-fold post processing. Therefore, processing with this device may augment production of pro-inflammatory cytokines. Bone Marrow Transplantation (2000) 25, 1223-1228.

Antigens, CD34↗

Sumatriptan for headache caused by head and neck cancer.

The use of sumatriptan for the treatment of migraine and cluster headache is well established. Sumatriptan has also been reported to be effective for the treatment of postdural puncture headache, postictal headache, and headache related to intravenous immunoglobulin infusion. We report two patients with headache caused by locally invasive head and neck cancer relieved by oral sumatriptan.

Adult↗

Response to steroid therapy in autism secondary to autoimmune lymphoproliferative syndrome.

We report a child who developed autoimmune lymphoproliferative syndrome (ALPS) secondary to a heterozygous dominant negative mutation in the death domain of the Fas receptor. Previously developmentally normal, he had symptoms of autism with rapid regression in developmental milestones coincident with the onset of lymphoproliferation and autoimmune hemolytic anemia. Low-dose steroid therapy induced early and complete remission in the ALPS phenotype. There was subjective improvement, followed by objective improvement in speech and developmental milestones. We propose that autism may be part of the autoimmune disease spectrum of ALPS in this child, and this case represents a novel manifestation and target organ involvement in this disease.

Apoptosis↗

A randomized, double-blinded comparison of Thymoglobulin versus Atgam for induction immunosuppressive therapy in adult renal transplant recipients.

BACKGROUND: The aim of this study was to compare the efficacy and safety of Thymoglobulin (a rabbit-derived polyclonal antibody) to Atgam (a horse-derived polyclonal antibody) for induction in adult renal transplant recipients. METHODS: Transplant recipients (n=72) were randomized 2:1 in a double-blinded fashion to receive Thymoglobulin (n=48) at 1.5 mg/kg intravenously or Atgam (n=24) at 15 mg/kg intravenously, intraoperatively, then daily for at least 6 days. Recipients were observed for at least 1 year of follow-up. RESULTS: By 1 year after transplantation, 4% of Thymoglobulin-treated patients experienced acute rejection compared with 25% of Atgam-treated patients (P=0.014). The rate of acute rejection was lower with Thymoglobulin than Atgam (relative risk=0.09; P=0.009). Rejection was less severe with Thymoglobulin than Atgam (P=0.02). No recurrent rejection occurred with Thymoglobulin compared with 33% with Atgam (P=NS). Patient survival was not different, but the composite end point of freedom from death, graft loss, or rejection, the "event-free survival," was superior with Thymoglobulin (94%) compared with Atgam (63%; P=0.0005). Fewer adverse events occurred with Thymoglobulin (P=0.013). Leukopenia was more common with Thymoglobulin than Atgam (56% vs. 4%; P<0.0001) during induction. The mean absolute lymphocyte count remained below baseline with Thymoglobulin throughout the study (P<0.007), but with Atgam, significant lymphocyte reductions occurred only at day 7. The incidence of cytomegalovirus disease was less with Thymoglobulin than Atgam at 6 months (10% vs. 33%; P=0.025). CONCLUSIONS: Brief (7-day) induction with Thymoglobulin resulted in less frequent and less severe rejection, a better event-free survival, less cytomegalovirus disease, fewer serious adverse events, but more frequent early leukopenia than induction with Atgam. These results may in fact be explained by a more profound and durable beneficial lymphopenia.

Adolescent↗

Unusual presentations of nonmycotic hepatic artery pseudoaneurysms after liver transplantation.

The clinical presentation and causes of hepatic artery pseudoaneurysm vary widely in the postoperative liver transplant recipient, although infection is the most common cause. Although uncommon, hepatic artery complications continue to be an important source of morbidity in liver transplant recipients. Thrombosis, stenosis, and pseudoaneurysm formation are the most common posttransplantation arterial complications. Pseudoaneurysms are most commonly mycotic in origin. Prompt recognition of hepatic artery pseudoaneurysms with aggressive intervention (both surgical and angiographic) may decrease the morbidity associated with this rare clinical entity. The records of 263 consecutive patients who underwent orthotopic liver transplantation between 1991 and 1996 were reviewed retrospectively and assessed for hepatic artery complications. Two patients (0.7%) developed hepatic artery pseudoaneurysm, neither associated with infection. Both patients required operative repair and are doing well without vascular complications at a mean follow-up of 22.5 months. The clinical presentation and causes of hepatic artery pseudoaneurysm vary widely in the postoperative liver transplant recipient. Prompt recognition of hepatic artery pseudoaneurysms with aggressive intervention (both surgical and angiographic) may decrease the morbidity associated with this rare clinical entity.

Adult↗

Immune reconstitution following allogeneic peripheral blood stem cell transplants.

Growth factor-mobilized peripheral blood stem cells (PBSCs) engraft rapidly in myeloablated recipients compared to conventional BM, but this procedure also mobilizes mature lymphocytes and monocytes which can impact immune reconstitution and GVHD. Hence, we serially evaluated immune reconstitution and cytokine expression in PBSCT recipients in the first year. Engraftment of neutrophils and monocytes stabilized early but NK cells, B cells and CD4+ T cell numbers were significantly (P < 0.05) low with persistently reversed CD4:CD8 ratios. NK function remained low throughout the first year. The quantitative decrease in CD4+ T cells resulted in significantly decreased proliferation in response to mitogens and alloHLA antigens. Yet, a qualitative analysis of T cell function measured by Ca++ influx after T cell activation with antiCD3 as well as T-dependent polyclonal Ig secretion by mitogen-stimulated B cells was preserved even early post transplant. TNF alpha mRNA was detected in almost all recipients in the first year. IL-10 mRNA was detected in 77%, IL-2 in 22% and IFN gamma in 44% of recipients in the first 6 months. Only 30% expressed IL-10 in the second 6 months post transplant while expression of IL-2 and IFN gamma was detected in 38% and 46% respectively. Thirty-seven percent of PBSCT recipients developed grades II-IV acute GVHD but 72% went on to develop chronic extensive GVHD at a median of 120 days. Sixty-two percent developed CMV viremia and 5.4% developed overt CMV disease in the first year post PBSCT. Lymphocyte engraftment is quantitatively delayed but CD4 functions are preserved while NK numbers and function are compromised post PBSCT. IL-10 expression decreases after the first 6 months post transplant while TNF alpha is continually expressed. The balance between quantitative lymphocyte reconstitution and qualitative lymphocyte functions as well as changes in lymphokine patterns may influence infection and GVHD and thus the clinical outcome post PBSCT.

Adolescent↗

Diagnosis of pulmonary embolism by use of urinary TNF alpha and its soluble TNF receptor I.

The purpose of this clinical study was to determine the concentration of soluble tumor necrosis factor in urine of patients with pulmonary embolism (PE), verses voluntary control individuals. Sixteen patients (ages 24 to 74 years) with diagnosis of PE, documented by ventilation perfusion scan or pulmonary angiogram, were the subjects of this study. Ten cc of urine was obtained from each patient and subjected to a solid-phase enzyme-linked immunosorbent assay thus determining the soluble tumor necrosis factor (TNF) receptor I (R I) and TNF alpha levels in these samples. In this pilot study of PE cases, a statistically significant elevation in urinary levels of TNF alpha and soluble TNF R I was demonstrated in PE patients. The average urinary soluble TNF R I in normal subjects was 1,029 pg/mL and in PE patients the average TNF R I was 3,734.4 pg/mL. The clinical diagnosis of PE is a challenging problem for the physician. Late diagnosis and delayed management of this condition could be associated with massive PE. Although pulmonary angiography is the gold standard for diagnosis of PE, it requires expensive equipment, trained radiologists, and the patient could be at risk of sensitivity to contrast agents.

Adult↗

Long-term follow-up of high-risk allogeneic peripheral-blood stem-cell transplant recipients: graft-versus-host disease and transplant-related mortality.

PURPOSE: To determine the risks of graft-versus-host disease (GVHD) and transplant-related mortality after allogeneic peripheral-blood stem-cell (PBSC) transplantation. PATIENTS AND METHODS: Between December 1994 and July 1996, 50 consecutive patients with high-risk hematologic malignancies in first remission or relapse received high-dose therapy followed by transplantation of granulocyte colony-stimulating factor-mobilized, allogeneic PBSCs collected from HLA-identical siblings. GVHD prophylaxis included cyclosporine and corticosteroids. RESULTS: As of April 1, 1998, 18 patients (36%+/-13%) survived with a median follow-up period of 767 days (range, 602 to 1,127 days). The actuarial probability of grades 2-4 acute GVHD was 0.37+/-0.14 (95% confidence interval). Of 36 assessable patients, 26 (72%+/-15%) developed chronic GVHD. The actuarial probability of chronic GVHD 2 years after transplantation was 0.87+/-0.15. Of 14 progression-free survivors, 11 (79%+/-22%) have active, chronic GVHD. All 11 patients require ongoing immunosuppression, and nearly two thirds have extensive disease. Thirteen patients died as a result of transplant-related mortality (26%+/-12%), six (12%) before and seven (14%) after day +100. CONCLUSION: We observed a high risk of chronic GVHD after allogeneic PBSC transplantation, which compromised the performance status of most long-term survivors and resulted in a relatively high risk of late transplant-related mortality. Approximately 75% of transplant-related deaths were associated with GVHD; thus, reduction in transplant-related mortality after allogeneic PBSC transplantation will require more effective strategies for the prophylaxis and/or treatment of GVHD.

Adolescent↗

CSF rhinorrhoea from unusual site : report of two cases.

CSF rhinorrhoea is associated with high morbidity and mortality. Bone and dural defects may result from trauma or enlarging 'pitholes' or breach in lateral recess of sphenoid sinus. Unless surgically corrected, they tend to cause meningitis and rhinorrhoea. Unusually delayed rhinorrhoea is a diagnostic problem.

Cerebrospinal Fluid Rhinorrhea↗

Development of heparin antagonists with focused biological activity.

Heparin, a complex glycosaminoglycan, has long been used to temporarily render the blood incoagulable during extracorporeal circulation, cardiovascular surgery, and other arterial interventions. But bleeding complications are especially common when the arterial tree is violated, occurring in as many as 10-15% of cases. For cardiovascular surgery and many related interventions, protamine has long been the standard antagonist when acute and complete neutralization of heparin s anticoagulant effect is necessary. Protamine s efficacy is related in part to its total net cationic charge, but unfortunately so is its toxicity. For these reasons, there is renewed interest in developing heparin antagonists which will replace the use of protamine. At Commonwealth Biotechnologies, Inc., we have used a rationale design approach for the preparation of a family of low molecular weight helix peptides which bind heparin with high affinity. For each of the new compounds, we have assessed their ability to bind heparin using isothermal titration calorimetry and circular dichroism spectrometry and have examined potential complexes formed with the anticoagulant pentasaccharide unit of heparin using molecular modeling techniques. The biological potencies of these compounds were assessed in ex vivo experiments where their ability to compete with antithrombin for binding heparin was determined. The best of the compounds, designated HepArrestTM, is highly effective in reversing heparin-mediated and HepArrest is a safer drug than protamine because of reduced adverse hemodynamic side effects compared with those associated with protamine. HepArrest binds low molecular weight heparins and causes reversal of anticoagulation by low molecular weight heparins, as determined by activated partial thromboplastin time, thrombin time, or factor Xa neutralization assays. These highly promising preclinical results indicate that HepArrest is a novel heparin neutralizing agent that may well fill a substantial unmet need for vascular surgeons and cardiac anesthesiologists who perform coronary artery bypass grafts and several other major vascular surgeries, as well as for cardiologists and interventional radiologists.

Animals↗