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Biomedical subjects

J Radhakrishnan

Publications and source records attributed to J Radhakrishnan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Significance of fractional excretion of sodium and endothelin levels in the early diagnosis of renal failure in septic neonatal piglets.

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.

Acute Kidney Injury↗
PubMed1996

Air rifles--lethal weapons.

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.

Adolescent↗
PubMed1996

Biocompatible dialysis membranes and acute renal failure: a study in post-operative acute tubular necrosis in cadaveric renal transplant recipients.

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.

Adult↗
PubMed1995

Progressive renal insufficiency following cardiac transplantation: cyclosporine, lipids, and hypertension.

The increasing success of cardiac transplantation has been attributed to the availability of potent immunosuppressive agents, including cyclosporine. With improved graft and patient survival, the incidence of chronic renal insufficiency has increased. We reviewed the medical records of patients who had undergone orthotopic cardiac transplantation and had been followed for at least 3 years posttransplantation to determine the risk factors at initial evaluation and in the early posttransplantation period for subsequent renal insufficiency. We followed 80 adult patients over a mean period of 4.7 years: 39 patients had a serum creatinine > or = 2.4 mg/dL at last follow-up (renal insufficiency or RI group); 41 patients had a serum creatinine < or = 1.7 mg/dL at last follow-up (controls). RI patients tended to be older and had a lower mean glomerular filtration rate (GFR) at initial evaluation. There were no differences in race, gender, or previous history of hypertension between the two groups. Although both groups experienced an improvement in GFR at transplantation and a subsequent decline in GFR by 6 months posttransplantation, the RI group achieved a lower peak GFR at transplantation and a far lower mean GFR at the 6-month analysis. Only the RI group showed a continued decline in GFR. The RI group had more severe hypertension and required a significantly greater number of antihypertensive medications. The RI group had a higher mean total cholesterol at 6 months, but this difference was not sustained. They also had higher triglyceride levels and lower high-density lipoprotein (HDL) levels; there was no difference in low-density lipoprotein (LDL) levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Thoracic BB injuries in pediatric patients.

Penetrating thoracic injury from BB shot remains an innocuous event in most patients, but factors including location, proximity, gun type, and patient weight may identify groups at risk. The following cases demonstrate morbidity and mortality in two patients, and this experience may suggest the need for reassessment of this injury.

Adolescent↗
PubMed1994

Renal transplantation in anticardiolipin antibody-positive lupus erythematosus patients.

Up to 44% of patients with systemic lupus erythematosus have antiphospholipid antibodies, which in some patients have been associated with thrombocytopenia, in vitro coagulation abnormalities, and a thrombotic tendency. Patients with lupus nephritis who reach end-stage renal disease may continue to have anticardiolipin antibodies (ACL-Ab) at the time of renal transplantation despite a lack of clinical or serologic activity of systemic lupus. The risk of thrombotic and other complications has not been previously reported in these patients. To evaluate the effect of ACL-Ab on the course of renal transplantation, the clinical course of eight ACL-Ab-positive lupus patients transplanted in the period from January 1990 to June 1992 were compared with five ACL-Ab-negative lupus patients transplanted during the same period. All patients had lupus nephritis as the cause of renal failure. There were four thrombotic episodes in the patients who were ACL-Ab-positive but none in the control group. Neither of the two groups differed in the number of rejection episodes, the rate of graft loss, or renal function at last follow-up. Patients with systemic lupus erythematosus who are ACL-Ab-positive can be successfully transplanted. However, these patients require attention to possible thrombotic events with a potential role for prophylactic anticoagulation.

Adult↗
PubMed1994

Intravenous pulse cyclophosphamide treatment of severe lupus nephritis: a prospective five-year study.

Despite its widespread use, there are only a few published studies of the use of intravenous high dose pulse cyclophosphamide in systemic lupus nephritis. There are few data about the long-term efficacy and safety of this form of therapy. This study evaluates the clinical efficacy, toxicity, and effects on renal morphology of this regimen in patients with severe lupus nephritis followed prospectively over a five-year period. Twenty consecutive patients with severe active lupus nephritis were enrolled in a treatment regimen of six monthly intravenous pulses of cyclophosphamide (0.5 to 1 g/m2) together with high dose corticosteroid therapy which was rapidly tapered. Efficacy was assessed by improvement or stabilization of clinical, serologic and renal functional parameters. Repeat renal biopsies were performed in 15 patients. Potential toxicity related to therapy was documented. Over the first six months of treatment, this regimen resulted in improvement of clinical activity, lupus serology, stabilization of renal function and decreased proteinuria in 19/20 patients. Nephrotic syndrome remitted in 8/10 patients by one year. Over five years of follow-up, there were five treatment failures defined as a doubling of serum creatinine over baseline. At five years, 3 patients required renal replacement therapy. Elevated plasma creatinine at time of first biopsy, degree of proteinuria, histologic activity and chronicity were not statistically correlated with treatment failure. Patients who failed to respond to this treatment were, however, more likely to have diffuse proliferative lupus nephritis (WHO Class IV) lesions on initial biopsy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Cyclosporine treatment of lupus membranous nephropathy.

Few studies describe the treatment of membranous nephropathy associated with systemic lupus erythematosus. Although cyclosporine-A has been used to treat patients with the nephrotic syndrome and also with systemic lupus, only a few of these patients have had lupus membranous nephropathy. In this pilot study, we assessed the safety and efficacy of cyclosporine in ten nephrotic patients with either pure membranous lupus nephropathy (seven patients) or membranous lupus nephropathy with superimposed mild proliferative lesions (three patients). Cyclosporine (4-6 mg/kg/day) alone (2 patients), or in conjunction with low dose corticosteroids (8 patients) was given for a period of up to 43 months. Six patients achieved a nadir proteinuria of less than 1 gram daily, two patients decreased urinary protein excretion to 1-2 grams daily, and the remaining two patients continued to excrete over 2 grams of protein daily. All patients experienced symptomatic improvement of their nephrotic syndrome and serum creatinine was not significantly increased at the end of the study period. Three patients with superimposed mild proliferative lesions experienced renal and systemic lupus flares while on treatment requiring additional immunosuppressive therapy. Side-effects were minor except for transient rises in serum creatinine in one patient and a case of drug-related hepatitis possibly caused by cyclosporine. Repeat renal biopsies in five patients revealed a decrease in the lupus activity index and a rise in the chronicity index. There was an increase in the stage of the membranous nephropathy on these repeat biopsies, but a reduction in the number of fresh deposits.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

The effect of prostaglandin E1 analog misoprostol on chronic cyclosporin nephrotoxicity.

Cyclosporin A has markedly improved graft survival in transplant patients but its side effects, such as renal toxicity and hypertension, pose management problems in transplant recipients. This toxicity has been attributed to prostaglandin inhibition. Concurrent administration of misoprostol (a prostaglandin E1 analog) prevents chronic cyclosporin A-induced nephrotoxicity but not hypertension in rats.

Aldosterone↗
PubMed1993

The nephrotic syndrome, lipids, and risk factors for cardiovascular disease.

The hyperlipidemia associated with the nephrotic syndrome is well characterized. There is, however, a paucity of data in humans on the risk factors for atherosclerotic heart disease and the role of hyperlipidemia on the risk of progression of renal disease in this population. In our study, we retrospectively evaluated a large uniform population of patients (mean creatinine, 1.78 mg/dL; mean 24-hour proteinuria, 7.1 g) with idiopathic nephrotic syndrome for the presence of risk factors for coronary artery disease. One hundred patients with either focal segmental glomerulosclerosis (n = 56) or membranous nephropathy (n = 44) were assessed for the following cardiovascular risk factors: male sex or postmenopausal female, hyperlipidemia, hypertension, smoking history, and left ventricular hypertrophy. Sixty-six percent of the patients were either male or postmenopausal females; 35% were smokers. Hypertension and left ventricular hypertrophy were present in 53% and 13% of patients, respectively. Eighty-seven percent, 53%, and 25% of patients had a total cholesterol of more than 200 mg/dL, more than 300 mg/dL, and more than 400 mg/dL, respectively. Low-density lipoprotein cholesterol was greater than 130 mg/dL and greater than 160 mg/dL in 77.2% and 64.9% of patients, respectively. Virtually all patients (99%) had at least one risk factor for cardiovascular disease; over two thirds (68%) had two risk factors and over one quarter (26%) had three risk factors. In comparing the group that progressed to renal failure with the groups that did not, the initial mean serum cholesterol was lower in the group that progressed (292 mg/dL v 388 mg/dL, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

The epidemiology of peritonitis in acute peritoneal dialysis: a comparison between open- and closed-drainage systems.

We performed a prospective study to examine the epidemiology and microbiology of peritonitis complicating acute intermittent peritoneal dialysis (IPD) performed in an in-hospital setting for the management of acute and chronic renal failure and to see the effect of a closed-drainage system on altering the frequency and cause of peritonitis. Over a 15-month period, 79 patients were treated with acute IPD for a total of 136 treatments each ranging in length from 2 to 40 days (median, 4 days). The majority of cases had acute renal failure (ARF; 65%) and were treated in intensive care units (ICUs; 74%) with serious comorbid conditions (60%). About half were treated with a two-bag, ventable (open)-drainage system with unprotected spikes, and the other half were treated with a single-bag, spike-protected, closed-drainage system. There were 27 cases of peritonitis for a rate of 4.5 cases/100 patient-days at risk. About half were gram-positive infections; the remainder were gram-negative or mixed (25%) or Candida sp (25%). The use of a closed-drainage system reduced the incidence of system-related peritonitis from 3.6 to 1.5 cases/100 patient-days. There was a high rate of peritonitis in the first 48 hours of treatment, which fell to a low stable rate thereafter and remained so for up to 15 days of continuous IPD. The use of a closed-drainage system eliminated the early (< 48 hours) high rate of peritonitis and maintained a low constant rate of peritonitis throughout treatment. There was an association of ARF and severe comorbid disease with more virulent organisms (gram-negative, mixed, and Candida sp), which, in turn, were both associated with antecedent broad-spectrum antibiotic therapy. Random positive surveillance cultures showed a frequency distribution similar to that of peritonitis cases over the duration of treatment, but with less virulent organisms. Peritonitis in acute IPD occurs when large or repeated inocula of organisms from the prevailing flora overwhelm the peritoneal immune clearance mechanisms. Prolonged courses of broad-spectrum antibiotic therapy provide no protection, but shift the resulting infecting flora toward more virulent pathogens. A closed-drainage system provides one method to reduce the frequency of peritoneal contamination.

Adolescent↗
PubMed1992

Evaluation of a computer program for teaching laboratory diagnosis of acid-base disorders.

A computer program was evaluated as a tool for increasing the diagnostic acumen of medical housestaff and students in identifying acid-base disorders. The participants were randomized into two groups; group A (N = 20) was encouraged to use the software, and group B (N = 19) was denied access. Pre- and post-tests were administered to delineate the groups' ability to identify correctly an acid-base disorder from laboratory data (electrolytes and arterial blood gas). During 6 weeks, group A used the computer for a mean of 2.83 h (range 1 to 6). The mean +/- SE number of correct answers out of 20 questions, prior to use of the computer program, were 5.7 +/- 0.8 (95% confidence interval 3.9 to 7.5) for group A and 5.2 +/- 0.6 (95% confidence interval 3.9 to 6.5) for group B. These results were not statistically different. Correct responses increased significantly in group A to 10.3 +/- 0.9 (P < 0.0001, 95% confidence interval 8.4 to 12.2) but did not increase significantly in group B. The data suggest that this software program was effective in increasing the diagnostic capabilities of medical housestaff and students for identifying acid-base disorders.

Acid-Base Imbalance↗
PubMed1992

Postoperative apnea in infants.

This is a review of 127 neonates evaluated for postoperative apnea and bradycardia (A&B) after inguinal surgery. The patients could be divided into three groups based on postconceptional age (PCA) at operation. Ten of 29 patients operated on at PCA of 33 to 39 weeks developed episodes of A&B. Preoperative assessment was not reliable in their identification. In the second group of 54 patients at PCA 40 to 44 weeks, 8 developed A&B, whereas in the third group of 44 patients at PCA of 45 to 60 weeks 1 patient developed A&B. In the latter two groups preoperative assessment identified all patients at high risk. We conclude that after PCA of 40 weeks patients at risk for A&B can be identified preoperatively. Patients operated on up to 39 weeks PCA should all be observed in the hospital.

Age Factors↗
PubMed1991

Colonic strictures following successful medical management of necrotizing enterocolitis: a prospective study evaluating early gastrointestinal contrast studies.

This is a prospective study of 50 patients with neonatal necrotizing enterocolitis (NEC) treated successfully by medical means. They were all screened with an upper gastrointestinal (GI) contrast study after 14 days of healing and prior to establishment of feeding. Thirty-six patients (72%) with normal upper GI examinations responded well to a graduated increase in feeding. Another 5 (10%) with questionable areas on their upper GI examination had a normal follow-up contrast enema. Feeding was successfully established in this group of infants also. The remaining 9 patients (18%) had demonstrable strictures in both contrast studies. After elective resection of strictures with restoration of intestinal continuity, they were also fed successfully. No delayed strictures were seen in any of the patients. We propose that this method of evaluation is safe, efficient and reliable in the diagnosis of strictures that develop in patients recovering from NEC.

Colonic Diseases↗