51
|
Radhakrishnan J, Kaito A. Structure formation during the isothermal crystallization of oriented amorphous poly(ethylene terephthalate) films. POLYMER 2001. [DOI: 10.1016/s0032-3861(00)00754-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
52
|
Abstract
The antiphospholipid syndrome is a disorder of hypercoagulability in association with circulating antiphospholipid antibodies directed against epitopes on oxidized phospholipids complexed with a glycoprotein, beta 2-glycoprotein I, or against the glycoprotein itself. Disorders associated with antiphospholipid antibodies but not the antiphospholipid syndrome, such as HIV and hepatitis C infection, appear to lack antibodies to beta 2-glycoprotein I. Patients with systemic lupus erythematosus have a high incidence of antiphospholipid antibodies with a high risk of thrombosis, often associated with anticardiolipin antibodies, beta 2-glyocoprotein I antibodies, and the presence of the lupus anticoagulant. Antiphospholipid antibodies are a significant cause of morbidity and mortality in renal patients with and without systemic lupus erythematosus. Renal manifestations include thrombotic microangiopathy and large vessel thrombosis. In patients with end-stage renal disease, antiphospholipid antibodies are prevalent and may increase in frequency with time on dialysis, possibly as a result of oxidative stress incurred during dialysis. The presence of anticardiolipin antibodies have been associated with a high incidence of hemodialysis access clotting. In renal transplant recipients, the incidence of antiphospholipid antibodies is also elevated and may be associated with a higher incidence of primary graft non-function. Although patients with systemic lupus erythematosus have similar renal allograft survival rates to the general population, survival is worse for those patients who are also antiphospholipid antibody positive. Additionally, in hepatitis C positive renal transplant recipients, the presence of anticardiolipin antibodies confers an increased risk of thrombotic complications and the development of thrombotic microangiopathy. Treatment of antiphospholipid antibody syndrome remains centered around anticoagulation with warfarin. The use of immunosuppressive agents has had no dramatic effect on antiphospholipid antibody titers and little clinical effect on thrombotic events.
Collapse
|
53
|
Wallen MD, Radhakrishnan J, Appel G, Hodgson ME, Pablos-Mendez A. An analysis of cardiac mortality in patients with new-onset end-stage renal disease in New York State. Clin Nephrol 2001; 55:101-8. [PMID: 11269672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
End-stage renal disease (ESRD) is associated with an overall one-year mortality of 23.5% in the US, of which cardiac causes constitute 50% of all deaths. Data on incident ESRD patients were obtained from the Health Care Financing Administration's 2728 and 2746 forms by special request from the ESRD Network of New York. 4,948 ESRD patients, who started dialysis in New York State from April 1, 1995, through April 1, 1996, were assessed to identify risk factors present at the initiation of dialysis that predict cardiac death. 899 deaths were registered during the 19-month-follow-up period, 50% of which were from cardiac causes. Using the Cox-proportional hazards model, the increasing age category, white race, the presence of one or more vascular co-morbid conditions, and the presence of diabetes and one or more cardiac co-morbid conditions significantly predicted cardiac death (p < 0.05). Diabetes increased the risk for cardiac death by 48% for those patients without any cardiac co-morbidities (RR = 1.48, p < 0.0082). In contrast with results observed in the general population, gender, serum albumin and body mass index were not significant predictors of cardiac death. In identifying risk factors present at the initiation ofdialysis that predict cardiac death, this study highlights factors that may be modified prior to dialysis initiation in order to improve life expectancy and mortality rates and decrease health care costs for the ESRD population.
Collapse
|
54
|
Miller G, Zimmerman R, Radhakrishnan J, Appel G. Use of mycophenolate mofetil in resistant membranous nephropathy. Am J Kidney Dis 2000; 36:250-6. [PMID: 10922302 DOI: 10.1053/ajkd.2000.8968] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Membranous nephropathy (MN) is a common cause of nephrotic syndrome. Optimal therapy for this disease is still debated. We report our experience using mycophenolate mofetil (MMF), an immunosuppressive agent widely used in transplant recipients, to treat 16 nephrotic patients with MN. All patients had biopsy-documented MN; secondary forms were ruled out. Fifteen patients had steroid-resistant disease; cytotoxic agents had failed in 6 patients and cyclosporine therapy had failed in 5 patients. Patients were treated with MMF (dose range, 500 to 2,000 mg) for a mean of 8 months. Six patients experienced a halving of proteinuria, which occurred after a mean duration of 6 months of therapy. Partial remissions occurred in 2 patients. There were no significant changes in mean values for serum creatinine, serum albumin, or proteinuria. Mean cholesterol levels were significantly less. Side effects of MMF were infrequent and generally mild. In summary, MMF appears to reduce proteinuria in some patients with idiopathic MN previously resistant to steroids, cytotoxic agents, or cyclosporine. Further trials with this agent are warranted.
Collapse
|
55
|
Chin AC, Radhakrishnan J, Slatton D, Geissler G. Congenital cysts of the third and fourth pharyngeal pouches or pyriform sinus cysts. J Pediatr Surg 2000; 35:1252-5. [PMID: 10945706 DOI: 10.1053/jpsu.2000.8766] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cysts arising from the III and IV pharyngeal pouches, although uncommon, are typical in their presentation. They occur in neonates, invariably in the left anterior neck and cause respiratory distress. Excision of the cyst with ligation of the tract at the level of the pyriform sinus is curative.
Collapse
|
56
|
Abstract
Cyclosporin is a potent immunosuppressive agent that has become the first line therapy in organ transplantation. Its efficacy has led to its use in a variety of immune-mediated glomerular diseases. A selection of controlled and uncontrolled trials has studied the effects of cyclosporin in patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), IgA nephropathy, membranoproliferative glomerulonephritis (MPGN) and lupus nephritis. We review the recent literature and suggest recommendations for using cyclosporin in these diseases, based on this evidence and our experience.
Collapse
|
57
|
Radhakrishnan J, Dikshit AK, Kaito A. Structure formation during isothermal crystallization of oriented isotactic polystyrene. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1099-0488(20001115)38:22<2912::aid-polb60>3.0.co;2-v] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
58
|
Radhakrishnan J, Kaito A, Tanigaki N, Tanabe Y. Conformational changes during the crystallization of poly(di-n-hexylsilane). POLYMER 1999. [DOI: 10.1016/s0032-3861(99)00193-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
59
|
|
60
|
Radhakrishnan J, Manickam K, Holterman M, Holterman AX. Antenatal urologic intervention: current status. Indian J Pediatr 1999; 66:751-7. [PMID: 10798137 DOI: 10.1007/bf02726267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The devastation caused by fetal obstructive uropathy is now well known. At the most severe end of the spectrum of obstructive uropathy not only is the developing kidney damaged but the resultant oligohydra-mnios prevents pulmonary development and causes skeletal defects. The most significant changes are noted in patients with posterior urethral values (PUV). The obvious solution to the problem is to either correct or by pass the obstruction prior to the development of permanent changes. Unfortunately, this simple concept is not easy to apply since it raises numerous ethical, legal, economic and technical problems.
Collapse
|
61
|
Nguyen LB, Lievano G, Radhakrishnan J, Fornell LC, Jacobson G, John EG. Renal effects of low to moderate doses of dopamine in newborn piglets. J Pediatr Surg 1999; 34:996-9. [PMID: 10392921 DOI: 10.1016/s0022-3468(99)90776-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE Administration of dopamine to adult animal and human subjects results in increased renal blood flow, and it may also enhance the glomerular filtration rate. However, renal hemodynamic effects of exogenous dopamine in the neonate are unclear. In this study, we examined the renal actions of low to moderate doses of exogenous dopamine in newborn piglets. METHODS The animals were anesthetized, catheterized for vascular access and urine collection, and assigned randomly to a control group or treatment groups receiving dopamine infusion at 2, 5, or 10 microg/kg/min. Data were collected at baseline, during dopamine infusion, and 1 hour after cessation of infusion. Mean arterial blood pressure (MAP) and heart rate (HR) were monitored. Glomerular filtration rate (GFR), cardiac index (CI), and renal blood flow (RBF) were determined. Fractional excretion of sodium (FENa) was calculated. RESULTS Dopamine did not alter renal blood flow nor did it significantly alter CI in spite of a modest increase in heart rate and mean arterial blood pressure. There was a statistically significant increase in GFR at 10 microg/kg/min and in FENa at all doses. CONCLUSIONS Low doses of dopamine produce significant natriuresis probably by direct action on renal tubules and at moderate doses via, both, increase in GFR and a direct tubular effect. Low and moderate doses of dopamine do not increase RBF as seen in adult animals, possibly because of immaturity of dopaminergic receptors in newborn piglets.
Collapse
|
62
|
Lievano G, Nguyen L, Radhakrishnan J, Fornell L, John E. New animal model to evaluate testicular blood flow during testicular torsion. J Pediatr Surg 1999; 34:1004-6. [PMID: 10392923 DOI: 10.1016/s0022-3468(99)90778-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND/PURPOSE Unilateral testicular torsion is known to cause infertility because of damage to the contralateral testis. Testicular damage has been attributed to many different mechanisms, one of which is altered contralateral blood flow. In our experiment, in an effort to identify the reason for contralateral testicular injury, the authors developed an accurate method of measuring blood flow in both testes before, during, and after unilateral torsion. METHODS Four- to 6-week-old piglets weighing 4 to 6 kg were studied. The animals were anesthetized, intubated, ventilated, and catheterized for vascular access. Piglets were assigned randomly to a sham group or a group undergoing 360 degrees or 720 degrees torsion of the left testis (n = 5 per group) for 8 hours, after which it was untwisted. Data were collected at baseline (T = 0), 8 hours of torsion (T = 8), and 1 hour after detorsion (T = 9). Mean arterial blood pressure and heart rate were monitored continuously. Testicular blood flow was determined using radiolabeled microspheres. Blood flow data were evaluated by analysis of variance. RESULTS In the 360 degrees torsion group, blood flow changes were insignificant during torsion and after detorsion. In the 720 degrees torsion group, blood flow to the twisted testis was reduced significantly, whereas the contralateral testis was unaffected. One hour after detorsion, blood flow to both testes was increased significantly. CONCLUSIONS The authors describe a new animal model to evaluate testicular blood flow during and after testicular torsion. Increased blood flow after detorsion may be the cause of testicular damage in patients with unilateral testicular torsion.
Collapse
|
63
|
Nguyen L, Lievano G, Ghosh L, Radhakrishnan J, Fornell L, John E. Effect of unilateral testicular torsion on blood flow and histology of contralateral testes. J Pediatr Surg 1999; 34:680-3. [PMID: 10359163 DOI: 10.1016/s0022-3468(99)90355-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND/PURPOSE Infertility occurs in 25% of patients after unilateral testicular torsion; hence, the authors examined hemodynamic and histological changes in both testes after acute testicular torsion in neonatal piglets. METHODS The animals were anesthetized, intubated, ventilated, catheterized, and assigned randomly to a sham group or one of three experimental groups undergoing 720 degrees torsion of the left testis for 8 hours after which it was untwisted in group I and removed in group II. In group III, both testes were removed. Data were collected at baseline (T = 0), 4 hours (T = 4), and 8 hours of torsion (T = 8) and at the ninth hour of the experiment (T = 9). Testicular blood flow was determined by using radiolabeled microspheres. The testes also were examined blindly with routine and electron microscopy. RESULTS In group I, testicular blood flow decreased in the affected testis during torsion and increased significantly after detorsion, whereas blood flow to the contralateral testis increased significantly after detorsion. Sham-operated animals showed no histological abnormality in either testis. In all torsion groups, the affected testis showed extensive changes caused by hemorrhagic necrosis. The contralateral testis only showed changes in group I. CONCLUSION Unilateral testicular torsion resulted in ipsilateral damage caused by a decrease and subsequent increase in blood flow while in the contralateral testis; damage was the result of a significant increase in blood flow after detorsion.
Collapse
|
64
|
Abstract
Cyclosporine-A is primary therapy for organ transplantation. Its immunosuppressive effect might suggest a therapeutic role in autoimmune diseases, including several idiopathic and secondary glomerular conditions. Various forms of idiopathic nephrotic syndrome, including focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), and membranous nephropathy (MN), may respond well to cyclosporine in selected patients. However, frequent relapse limits its use to those who have failed to respond to, or were intolerant of, steroids or cytotoxics. Cyclosporine's efficacy in other glomerulopathies, such as IgA nephropathy (IgAN) and membranoproliferative glomerulonephritis (MPGN) remains poorly studied and, given the risk of nephrotoxicity, cannot be recommended for treatment of these entities until further data are available. Cyclosporine demonstrates some efficacy in treating proliferative lupus nephritis and, based on pilot study data, membranous lupus as well. Again, given relapse rates and potential nephrotoxicity, it should be used only in combination with azathioprine and steroids, assuming cytotoxic therapy has failed. Finally, cyclosporine toxicity is briefly reviewed.
Collapse
|
65
|
Radhakrishnan J, Tanigaki N, Kaito A. Electronic energy transfer in compatible blends of poly(di-n-hexylsilane) and poly(methyl-n-propylsilane). POLYMER 1999. [DOI: 10.1016/s0032-3861(98)00368-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
66
|
Valeri A, Joseph R, Radhakrishnan J. A large prospective survey of anti-cardiolipin antibodies in chronic hemodialysis patients. Clin Nephrol 1999; 51:116-21. [PMID: 10069647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
We prospectively measured anti-cardiolipin antibody (ACLA) levels in 230 chronic hemodialysis (HD) patients over a 2-year period. Twenty-nine percent of HD-patients were found to have elevated IgG-ACLA titers. Males were more likely to have elevated IgG-ACLA titers. Elevated IgG-ACLA titers correlated with shortened AVG survival in HD-patients (mean of 156 vs. 238 days, p<0.05). There was no statistically significant correlation with access survival in AVF-patients. There seemed to be a higher mean IgG-ACLA titer in diabetics but they did not have statistically significant shorter angioaccess survival times. By logistic regression analysis, only IgG-ACLA positivity was predictive of premature angioaccess failure (p<0.05). In a selected subset of 16 patients with frequent angioaccess (AVG) failure and elevated IgG-ACLA levels, coumadin, titrated to an INR of 2 - 3, was found to produce a small (though statistically significant) prolongation of AVG survival.
Collapse
|
67
|
Lievano G, Nguyen L, Radhakrishnan J, Fornell L, Joshi A, John EG. Significance of fractional excretion of sodium and endothelin levels in the early diagnosis of renal failure in septic neonatal piglets. J Pediatr Surg 1998; 33:1480-2. [PMID: 9802795 DOI: 10.1016/s0022-3468(98)90479-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE This experiment was designed to help understand the cascade of events that end in renal impairment in septic animals. METHODS Twenty 3- to 8-day-old piglets were anesthetized and the femoral artery, jugular and femoral veins, and bladder were catheterized. After stabilization under anesthesia with ventilatory support, they were divided into a control group and three groups that received endotoxin (ETX) in doses of 0.01 mg/kg, 0.025 mg/kg, and 0.05 mg/kg. Blood pressure and blood gases were monitored continuously. Blood and urine samples were obtained before (B), 1 hour (E1), and 3 hours (E3) after the bolus of ETX to determine glomerular filtration rate (GFR), fractional excretion of sodium (FENa), tumor necrosis factor (TNF), and endothelin-1 (ET-1) levels. RESULTS Incremental doses of ETX induce greater release of ET-1 with an early proportionate increase in FENa (P< .05) and late decrease in GFR (P< .05). TNF release is dose and time dependent after ETX injection (P < .05). CONCLUSION ET-1 and FENa are the best tests to evaluate renal failure during early sepsis in neonatal piglets.
Collapse
|
68
|
Abstract
Description of a new technique for combining colovaginoplasty with rectal pull-through.
Collapse
|
69
|
Radhakrishnan J, Ichikawa K, Yamada K, Toda A, Hikosaka M. Nearly pure α2 form crystals obtained by melt crystallization of high tacticity isotactic polypropylene. POLYMER 1998. [DOI: 10.1016/s0032-3861(97)00617-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
|
70
|
|
71
|
Radhakrishnan J, Lievano G. Postnatal management of hydronephrosis diagnosed in utero. Indian J Pediatr 1997; 64:303-12. [PMID: 10771852 DOI: 10.1007/bf02845199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In this review we identify the causes of antenatal hydronephrosis and detail management options. A large majority of these patients can be treated safely and effectively after birth.
Collapse
|
72
|
Kikutani T, Radhakrishnan J, Arikawa S, Takaku A, Okui N, Jin X, Niwa F, Kudo Y. High-speed melt spinning of bicomponent fibers: Mechanism of fiber structure development in poly(ethylene terephthalate)/polypropylene system. J Appl Polym Sci 1996. [DOI: 10.1002/(sici)1097-4628(19961212)62:11<1913::aid-app16>3.0.co;2-z] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
73
|
Valeri A, Radhakrishnan J, Ryan R, Powell D. Biocompatible dialysis membranes and acute renal failure: a study in post-operative acute tubular necrosis in cadaveric renal transplant recipients. Clin Nephrol 1996; 46:402-9. [PMID: 8982557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Previous experimental and human data suggests a detrimental effect on the course of acute renal failure related to exposure of blood to artificial dialysis membranes of poor biocompatibility. We performed a 2.5-year prospective randomized trial to compare the clinical course of acute renal failure (post-operative ischemic acute tubular necrosis, ATN) in patients receiving a cadaveric renal transplant requiring supportive hemodialysis in the immediate post-transplant setting. Patients were randomized to either a cuprophane or polymethylmethacrylate (PMMA) conventional hollow fiber dialyzer. All patients received a standard immunosuppressive regimen which included induction therapy with either horse anti-thymocyte gamma globulin (ATGAM) or the murine anti-CD3 monoclonal antibody (OKT3). Of 53 patients randomized, 17 were excluded (2 for intervening biopsy-proven rejection prior to recovery from ATN, 10 for primary graft nonfunction and 5 for other reasons), leaving 36 evaluable cases of uncomplicated ATN, 18 in each group. There was no difference by age, race, gender, cause of ESRD, immunosuppressive regimen, cold or warm ischemia time, use of pre-transplant dialysis, percent oliguria or the incidence of intra-dialytic hypotension between the 2 groups. There was no difference in the mean time to recovery from ATN posttransplant (8.9 days in the cuprophane group vs 9.5 days in the PMMA group, p = NS) or in the average number of hemodialysis treatments required (3.6 in both groups, p = NS). There was also no difference in long term allograft outcome in terms of the nadir serum creatinine, the number of episodes of subsequent acute rejection or in the development of chronic rejection. An intent-to-treat analysis of all 53 originally randomized patients similarly yielded no significant differences. A subsequent, non-randomized study using a membrane of intermediate biocompatibility (Hemophan) also showed no difference in recovery time from ATN. Bioincompatible membranes do not seem to have a significant clinical impact on the course of recovery of this form of acute renal failure. The striking benefits of biocompatibility in the course of ARF seen in other human trials may relate more to the non-renal systemic toxic effects of bioincompatibility.
Collapse
|
74
|
Abstract
Modern air rifles are very powerful and potentially dangerous, yet they are sold without a license because they are considered toys. We report on 16 patients who were shot with air rifles. Nine of these patients were treated in the last 3 years. Seven patients sustained injuries to the chest and upper back. The BB (ball bearing) penetrated the aorta of two patients, one of whom died. One of two patients shot in the abdomen had injuries to the iliac artery and the colon. Three patients were shot in the head and neck, three in the extremities, and one through the penis. Particularly alarming to us is the fact that nine patients had been shot intentionally after minor arguments with other children. The assailants were neighborhood children in seven cases, a friend in five, and a sibling in two.
Collapse
|
75
|
Prasad ML, Radhakrishnan J, Wolf S. Inverted U-pouch ileal reservoir: a technique for conversion of straight ileoanal pull-through. J Pediatr Surg 1995; 30:1361-2. [PMID: 8523246 DOI: 10.1016/0022-3468(95)90506-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
|