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Biomedical subjects

E A Friedman

Publications and source records attributed to E A Friedman.

At least 145 records · Page 8Linked to original sources
PubMed1990

Effects of FUdR on primary-cultured colon carcinomas metastatic to the liver.

Hepatic arterial infusion of fluorodeoxyuridine (FUdR) has demonstrated efficacy in the treatment of metastatic colorectal carcinoma of the liver. In this study, the direct cytotoxic effect of FUdR was measured on ten metastatic and two primary-site colorectal carcinomas in a primary culture assay system. Overall, clinically achievable concentrations of FUdR (0.4 to 4 microM) induced partial cell kill in 75% of tumors, including a greater than 50% reduction in viable tumor cell number in only two tumors and less than 50% in the remaining seven. Total cell kill was not observed in any tumor. Three tumors were resistant to these FUdR concentrations. Tumor sensitivity correlated with the size of the tumor growth fraction. Increasing the exposure time to FUdR from 3 to 7 days approximately doubled the magnitude of the response. 5-Flurouracil and cisplatin, at clinically achievable concentrations, were more toxic to metastatic tumor cells than FUdR. Because of the limited chemosensitivity of metastatic colorectal tumor cells to FUdR in vitro, we postulate that other mechanisms besides direct cytotoxicity contribute to the clinical efficacy of FUdR in vivo.

Cell Line↗
PubMed1990

Geriatric diabetic nephropathy: an analysis of renal referral in patients age 60 or older.

We report a series of 33 consecutive hospitalized geriatric diabetic patients who were referred for evaluation of diabetic nephropathy, defined as proteinuria greater than or equal to 1 g/d (1,000 mg/24 h) or a serum creatinine concentration greater than or equal to 177 mumol/d (greater than or equal to 2 mg/dL). The study population was 60 years old or older (mean age, 68 +/- 6 years), was comprised mainly of women (24 of 33, 72.7%), and was predominantly black (25 of 33, 75.8%). All patients had type II diabetes. A family history of diabetes in parent or sibling was elicited in 24 (72.7%) patients. There were eight patients undergoing maintenance hemodialysis and 25 with less severe nephropathy (mean proteinuria, 2.7 g/d [2,700 mg/24 h]; mean creatinine clearance, 0.57 mL-s [34 mL/min]). Cardiac disorders were noted in the majority of patients: congestive failure in 20 (60.6%), myocardial infarction in eight (24.2%), and active angina in five (15.2%). Other comorbid diseases were present in both hemodialysis patients and the subset of nondialyzed azotemic-proteinuric patients, and consisted of peripheral neuropathy in 31 (93.9%), gastroparesis in 16 (48.5%), retinopathy in 28 (84.8%), and legal blindness in 11 (33%). We conclude that geriatric diabetic nephropathy in type II diabetes is similar in presentation and severity of comorbid extrarenal complications to the syndrome described in younger adults. This inference must be tempered by both the small size and the limitation imposed by the demographics of the study population, which is predominantly composed of black patients receiving treatment at inner city hospitals.

Aged↗
PubMed1990

Clinical and blood rheologic stability in erythropoietin-treated predialysis patients.

We assessed human recombinant erythropoietin (rHuEPO) as treatment for anemia in azotemic patients who did not require dialytic therapy. The study group consisted of 5 azotemic men and 5 women (mean serum creatinine concentration 5.2 +/- 3.2 mg/dl) whose mean hematocrit was 27.4 + 3.0%. Of these, 5 subjects had diabetic nephropathy. The study was a 12-month rHuEPO maintenance (open label) trial in which a previously established median i.v. dose of 50 U/kg was given three times each week. The rHuEPO was temporarily discontinued when the target hematocrit of 37% was achieved, and after the hematocrit decreased below 35%, it was restarted at half the initial dose. Of the 10 subjects who started the trial, 2 (both nondiabetic) deteriorated early in the study, and before a hematocrit rise was attained commenced maintenance hemodialysis. All subjects completed the year of study and achieved the target hematocrit. Mean hematocrit rose 42% (p less than 0.001) in a mean period of 3.3 +/- 1.3 months. When treatment was interrupted at a hematocrit of 37%, mean absolute reticulocyte count fell from 1.21 +/- 0.59% to 0.38 +/- 0.14% within one week. After rHuEPO was withdrawn, the increase in hematocrit persisted for a mean of 13.0 +/- 6.0 days and patients were able to sustain hematocrits above 35% for a mean of 1.44 +/- 0.6 months. Coincidentally with the rise in hematocrit during rHuEPO treatment, whole-blood viscosity increased significantly (p less than 0.001) but remained within the range for individuals with normal renal function at an equivalent hematocrit (p greater than or equal to 0.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Uninephrectomy does not potentiate contrast media nephrotoxicity in the streptozotocin-induced diabetic rat.

We studied the effect of radiographic contrast media on renal function in both streptozotocin-induced diabetic rats and normoglycemic rats with reduced renal functional mass. Male Sprague-Dawley induced-diabetic rats and weight-matched controls were divided into unilaterally nephrectomized and intact groups prior to an intravenous challenge with sodium diatrizoate (Urografin) at two dose levels, 1,300 and 2,600 mg iodine/kg. Serum creatinine concentration did not change on the 1st and 3rd day after a dose of 1,300 mg/kg of iodine in normal or induced-diabetic rats. Consequent to a dose of 2,600 mg/kg of iodine, induced-diabetic rats had a significant increase in serum creatinine levels to 0.9 +/- 0.45 mg/dl (control 0.68 +/- 0.11 mg/dl). The observed increase in serum creatinine concentration after treatment with sodium diatrizoate was significantly correlated with the degree of hyperglycemia, but not with prior unilateral nephrectomy. Unilateral nephrectomy, prior to administration of sodium diatrizoate did not potentiate the risk of radiocontrast agent injury in induced-diabetic rats. From these findings, we infer that: (1) streptozotocin-induced diabetes in the rat confers a risk for the development of radiocontrast-induced acute renal failure and (2) as judged by the rise in serum creatinine concentration after exposure, there is an increased risk of acute renal failure associated with a higher dose of radiocontrast material.

Acute Kidney Injury↗
PubMed1990

Care of the diabetic patient with end-stage renal disease.

Diabetic nephropathy is now the leading cause of renal failure in patients referred for uremia therapy. The diabetic patient is a complicated treatment problem from the first detection of microalbuminmuria, at which time decisions regarding choice of antihypertensive and strictness of metabolic control assume increasing importance. At present, our policy is to advocate strict control of blood pressure, aiming for a systolic blood pressure of less than 140 mm Hg and a diastolic blood pressure of less than 80 mm Hg. We attempt to maintain hemoglobin Alc levels at less than 8%, if the patient does not develop frequent episodes of hypoglycemia. We extend these recommendations to the patient with frank proteinuria, nephrotic syndrome and early uremia, understanding that strict metabolic control may be impossible as patients lose GFR. In addition, we recommend avoidance of a high protein diet in the early nephropathic diabetic, with diet of approximately 1 gm/kg/d. As renal failure progresses, we embark on an analysis of the patient's abilities, lifestyle, and social support. At a GFR of approximately 10 mL/min, we initiate preparations for uremia therapy. If a willing and appropriate living related kidney donor is available, the patient is referred for cardiovascular evaluation and kidney transplantation performed subsequently. If no donor is immediately available, we refer the patient for vascular access placement and/or insertion of a Tenckhoff peritoneal catheter, if preferred. Most of these predialysis patients also undergo screening for placement on the cadaveric kidney transplant list, including cardiac work-up as is done for the patients who receive living-related renal transplants. Because of the long waiting list in Brooklyn, and the universal shortage of organ donors, many of these patients eventually end up on dialysis for some period of time. Other extrarenal problems (urologic, ophthalmologic) are addressed at initial referral and followed up, in hopes of maintaining the patient in optimal physical shape as uremia progresses. The care of the diabetic patient with ESRD ideally involves a consortium of caregivers. We include a nurse-educator familiar with options for uremia therapy, a podiatrist, a cardiologist, and often a urologist, an endocrinologist, and a gastroenterologist. In addition, a social worker is helpful to assess psychologic difficulties in adjustment to uremia, socioeconomic considerations, and rehabilitation status. Finally, the nephrologist, as coordinator of this team works with the vascular or transplant surgeon, to facilitate the transition to ESRD and its therapy.

Diabetic Nephropathies↗
PubMed1989

Recombinant human erythropoietin in anemic patients with end-stage renal disease. Results of a phase III multicenter clinical trial.

STUDY OBJECTIVE: To determine the effectiveness and safety of recombinant human erythropoietin (rHuEpo). PATIENTS: Hemodialysis patients (333) with uncomplicated anemia (hematocrit less than 0.30). All received rHuEpo intravenously, three times per week at 300 or 150 U/kg body weight, which was then reduced to 75 U/kg and adjusted to maintain the hematocrit at 0.35 +/- 0.03 (SD). RESULTS: The baseline hematocrit (0.223 +/- 0.002) increased to 0.35, more than 0.06 over baseline within 12 weeks in 97.4% of patients. Erythrocyte transfusions (1030 within the 6 months before rHuEpo therapy) were eliminated in all patients within 2 months of therapy. Sixty-eight patients with iron overload had a 39% reduction in serum ferritin levels after 6 months of therapy. The median maintenance dose of rHuEpo was 75 U/kg, three times per week (range, 12.5 to 525 U/kg). Nonresponders had complicating causes for anemia, myelofibrosis, osteitis fibrosa, osteomyelitis, and acute or chronic blood loss. Adverse effects included myalgias, 5%; iron deficiency, 43%; increased blood pressure, 35%; and seizures, 5.4%. The creatinine, potassium, and phosphate levels increased slightly but significantly. The platelet count increased slightly but there was no increase in clotting of vascular accesses. CONCLUSIONS: The anemia of hemodialysis patients is corrected by rHuEpo resulting in the elimination of transfusions, reduction in iron overload, and improved quality of life. Iron stores and blood pressure must be monitored and treated to maintain the effectiveness of rHuEpo and to minimize the threat of hypertensive encephalopathy.

Adolescent↗
PubMed1989

Toward a hybrid artificial pancreas.

Management of insulinopenic diabetic individuals centers on administration of insulin by means of multiple injections, a wearable or implantable insulin-infusion pump, or a whole-organ or segmental-pancreas transplant. Preliminary trials indicate that surgical implantation of a hybrid device containing living insulin-secreting tissue may function as a combined glucose sensor and insulin-infusion pump. By means of a chamber composed of a semipermeable membrane shaped into hollow fibers or a box surrounding endocrine tissue, pilot studies have shown that isolated islets of Langerhans, fragments of insulinoma, or a fetal pancreas retains function for days to weeks, as judged by the ability to sustain euglycemic conditions in chemically induced diabetic rats. Lacking clear proof that normalizing blood glucose levels will prevent vascular complications of diabetes in humans, the case for further development of a hybrid (tissue plus fabricated components) device rests mainly on optimistic extrapolation of results attained in the chemically induced diabetic rat and dog. For the minority of diabetic patients who have insulin-dependent diabetes, the benefit afforded by a bionic device establishing internal insulin release regulated by silently sensed blood glucose level is more than enough payoff for the discomfort and surgery involved in its implantation. Further trials of a hybrid artificial pancreas in the dog appear warranted as a logical extension of preliminary studies with this species.

Animals↗
PubMed1989

Hyperlipidemia after organ transplantation.

Hyperlipidemia, long recognized as a difficult and common problem following organ transplantation, may be the underlying cause of the accelerated atherosclerosis observed in heart transplant recipients and children with renal transplants. In addition, hyperlipidemia may play a role in late renal graft loss. The cause of post-transplant hyperlipidemia is unclear. In patients treated with azathioprine and prednisone, hypertriglyceridemia is the commonest finding and probably results from an increased consumption of calories from carbohydrate and fat following resolution of uremia, in conjunction with glucose intolerance secondary to steroid administration. In patients treated with cyclosporine, hypercholesterolemia is the most common form of hyperlipidemia. Cyclosporine is a lipophilic drug that is transported in the plasma, largely in association with lipoproteins, and may require the low-density lipoprotein (LDL) receptor for internalization into cells. Hypercholesterolemia may result from interference with the basic cholesterol feedback mechanism via the LDL receptor. In addition, cyclosporine affects bile acid synthesis and worsens glucose tolerance, both factors that may promote hyperlipidemia. The first therapeutic approach to hyperlipidemia in the transplant recipient is dietary calorie-fat restriction and supplementation with soluble fiber. Ongoing clinical trials of the available pharmacologic lipid-lowering agents are addressing the safety and efficacy of these agents in the setting of immunosuppression; until that time, they should be used cautiously and in low doses.

Azathioprine↗