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Biomedical subjects

B Bennett

Publications and source records attributed to B Bennett.

At least 181 records · Page 10Linked to original sources

The effect of captopril on urinary protein excretion in puromycin aminonucleoside nephrosis in rats.

We investigated the effect of captopril, an orally active angiotensin converting enzyme inhibitor, on urinary protein excretion in puromycin aminonucleoside nephrotic rats. The administration of captopril (10 mg/100 g body weight) decreased proteinuria on days 10-14 following the administration of puromycin aminonucleoside (73.0 versus 125.0 mg, p less than 0.01), without affecting glomerular filtration rate. The beneficial effect of captopril was not abolished by the continuous intravenous infusion of angiotensin II (10 micrograms/kg/h for 9 days) or subcutaneous injections of aprotinin (50,000 KIU/day for 3 days). Indomethacin, in moderate (5 mg/kg/day for 3 days) or high (10 mg/kg/day) doses, abolished the captopril attenuation in urinary protein excretion. The salutory effect of captopril was characterized by a reduction in the fractional excretion of protein without compromising the glomerular filtration rate. No difference in renal ultrastructure was noted in captopril-treated versus control animals. Captopril was ineffective in reducing urinary protein excretion in rats with adriamycin-induced glomerulopathy. We conclude that captopril acts to reduce proteinuria in renal disease states arising from depletion of the glomerular basement membrane polyanion. The mechanism of action is postulated to be an alteration in renal hemodynamics, namely increased blood flow and a decrease in the ultrafiltration coefficient, that are the consequence of increased intrarenal prostaglandin production.

Angiotensins↗

Isolated hematuria in children: indications for a renal biopsy.

Previous reviews of hematuria in children and adolescents have included patients with proteinuria and other renal functional abnormalities such as hypertension and reduced GFR. We report the clinico-pathological correlations in 76 pediatric patients, aged 3 to 19 years, who underwent a renal biopsy because of isolated hematuria during the 10-year period, 1972 to 1981. All specimens were examined by light and electron microscopy and immunofluorescence techniques. The overall prevalence of abnormal renal histology was 56%. The vast majority (41 of 43) of the abnormal biopsy specimens could be classified into four distinct histological categories: (1) Alport syndrome (N = 9); (2) IgA nephropathy (N = 8); (3) thinning of the glomerular basement membrane (N = 17); (4) vascular C3 staining (N = 7). The children were divided into three clinical subgroups (1) isolated microscopic hematuria ( IMH ), N = 42; (2) IMH plus a family history of hematuria in a first degree relative, N = 15; and (3) IMH plus at least one episode of gross hematuria, N = 19. A significant graded increase in the likelihood of obtaining an abnormal renal biopsy was demonstrated (X2 = 10, P less than 0.007) from groups one to three. Sex, age at onset, or duration of hematuria were not associated with an increased proportion of histopathologic abnormalities. These findings indicate that the yield of a renal biopsy in children with isolated hematuria can be predicted accurately from specific clinical characteristics.

Adolescent↗

Transferrin in disease. I: A potential prognostic indicator in patients undergoing bone marrow transplantation.

Transferrin levels were measured immunochemically and the levels of several other plasma proteins were estimated by high resolution agarose gel electrophoresis in serial serum samples from nine patients undergoing bone marrow transplantation for aplastic anemia or leukemia. Three of five patients with low pretreatment transferrin levels died during initial hospitalization, and the other two suffered severe complications prior to recovery. All four patients with pretreatment transferrin levels within the normal range were discharged, three of them with minimal complications. Serial studies demonstrated that transferrin levels fell with the onset of infections or graft-versus-host disease and rose with recovery. Similar changes were not seen with any of the other plasma proteins measured. These results suggest that measurement of serum transferrin may reveal important prognostic information about patients undergoing bone marrow transplantation.

Adolescent↗

Transferrin in disease II: defects in the regulation of transferrin saturation with iron contribute to susceptibility to infection.

Patients with leukemia were found to have a high percentage of saturation of their serum transferrin with iron to an extent only rarely observed with other malignancies. This was associated with a reduced ability of their serum to inhibit the growth of a test strain of Pseudomonas aeruginosa. Serum iron, transferrin, and related parameters were measured serially in patients undergoing bone marrow transplantation for leukemia or aplastic anemia. It was found that a high proportion of these patients also have a high saturation of their transferrin with iron. This was related to three distinct physiologic deficits: a low level of serum transferrin; a high level of iron; and an inability to reduce the level of serum iron during infection. Three of six patients who were unable to reduce their serum during fever and infection subsequently died of sepsis. These data support the hypothesis that derangements in nonspecific serologic defense mechanisms involving iron contribute to susceptibility to infection in patients with leukemia undergoing bone marrow transplantation.

Adolescent↗

Plasmin-alpha 2-antiplasmin complexes in bleeding disorders characterized by primary or secondary fibrinolysis.

A two-dimensional immunoelectrophoresis (2DIEP) method detects plasmin complexed to its major inhibitor, alpha 2-antiplasmin, in plasma in the blood of patients during (a) thrombolytic therapy with urokinase, (b) episodes of disseminated intravascular coagulation (DIC) with active fibrinolysis, and (c) episodes of fibrinolytic haemorrhage without evidence of DIC. Clearance of the complexes from the blood is rapid and their detection thus implies active plasmin generation at the time of blood sampling or within the preceding 24 h. Abolition of the complexes using tranexamic acid therapy allowed surgery without bleeding in two previously grossly haemorrhagic patients in group (c). Antithrombin III complexed with activated procoagulants was detected using a similar 2DIEP method in only two of four patients with DIC. Abnormalities of alpha 2-macroglobulin were detected on 2DIEP of plasma in the patients studied with proteolytic disorders; these did not appear to reflect complex formation.

Abruptio Placentae↗

Prophylactic antithrombotic therapy with stanozolol in patients with familial antithrombin III deficiency.

Three patients with familial antithrombin III deficiency underwent a trial of prophylactic antithrombotic therapy with stanozolol. An increase in plasma fibrinolytic activity and antithrombin III was seen. Acute venous thrombosis occurred in two patients; in the first patient thrombosis was precipitated by venography but in the second no precipitating factor was found. Our experience suggests that stanozolol is not a suitable prophylactic agent in patients with familial antithrombin III deficiency.

Antithrombin III↗

Measurement of platelet life-span in normal subjects and patients with myeloproliferative disease with indium oxine labelled platelets.

The use of 111Indium oxine as a platelet label for the performance of platelet life-span studies has been examined. Platelet life-span in normal subjects varied between 8 X 10 and 10 X 36 d. Patients with primary thrombocythaemia had clearly reduced platelet life-span whether or not they presented with vascular occlusion and this abnormality persisted after reduction of the platelet count to normal by busulphan therapy. Patients with similarly elevate platelet counts due to chronic granulocytic leukaemia or after splenectomy had platelet life-span values in the normal range. Plasma beta-TG levels could not be used to predict platelet life-span in these groups of patients. Measurement of platelet life-span using 111Indium labelled platelets is a useful technique in the examination of platelet function in occlusive vascular disease.

Adult↗

Haemorrhage associated with large abdominal aortic aneurysms.

Two patients are described who each had a major haemorrhage after minor surgery and who additionally had large abdominal aortic aneurysms. Neither had depletion of platelets or coagulation factors sufficient to account for bleeding. Both had grossly enhanced fibrinolytic activity with evidence of plasmin generation in the circulation. In one patient insertion of an aortic graft was rapidly followed by resolution of the fibrinolytic abnormalities. Overactive fibrinolysis, rather than coagulation factor consumption may account for some of the bleeding syndromes complicating abdominal aortic aneurysms.

Aged↗

Plasminogen activators in alcoholic cirrhosis: demonstration of increased tissue type and urokinase type activator.

Plasma samples from patients with alcoholic cirrhosis were analysed for plasminogen activators and for inhibitors of the fibrinolytic system. Plasminogen activator activity was considerably increased in patients' plasma compared with normal. Immunochemical characterisation of these plasminogen activators showed that they included both tissue type and urokinase type plasminogen activator. The major inhibitor of plasmin, alpha 2-antiplasmin, was decreased in the patients, but no evidence for the generation of plasmin was found.

Electrophoresis, Polyacrylamide Gel↗

Standardized automated assay for functional alpha 1-antitrypsin.

We describe an enzymic assay for the functional activity of alpha 1-antitrypsin, in which tosyl-Gly-Pro-Lys-p-nitroanilide acetate (Chromozym PL) is the trypsin substrate. For the indicating reaction, the concentration of substrate is about double the Km of its reaction with trypsin. This assay is an improvement over reactions involving N-alpha-benzoyl-DL-arginine p-nitroanilide as substrate, the solubility of which in water is less than the Km of its reaction with trypsin. The assay is standardized in terms of active sites of trypsin inhibited per liter of serum, with p-nitrophenyl-p'-guanidinobenzoate as the active site titrant. The results agreed well with those by an immunonephelometric assay for alpha 1-antitrypsin (r = 0.953). The within-run and run-to-run precision was approximately 3%. The results of the assay varied linearly with alpha 1-antitrypsin concentration from 0 to 60 mumol/L of serum. The minimum sample size was 50 microL, and analysis of 24 samples took less than 20 min.

Aniline Compounds↗

The value of autologous indium (111In)-labelled platelets in the diagnosis of renal transplant rejection.

Serial pelvic imaging after injection of autologous platelets labelled with 111In was used to study 22 consecutive patients following cadaver renal transplantation. Increases in isotope uptake by the allografts were observed during episodes of acute rejection (12/22) but not during acute tubular necrosis (4/22). The technique was not influenced by oliguria or hemodialysis therapy. Extra-renal accumulations of labelled platelets were noted in perinephric hematomata and deep vein thromboses.

Acute Kidney Injury↗

The adjuvant activity of nonionic block polymer surfactants. II. Antibody formation and inflammation related to the structure of triblock and octablock copolymers.

We tested the ability of 17 surface-active agents to enhance antibody formation and inflammation. The surfactants were all block copolymers of hydrophilic polyoxyethylene (POE) and hydrophobic polyoxypropylene (POP), which differed in m.w. and mode of linkage of POP to POE. Mice were injected in each rear footpad with 1.25 mg of each surfactant with 25 micrograms of bovine serum albumin in an oil-in-water emulsion. Each agent produced a distinct pattern of immune response and inflammation. Preparations that are large and insoluble with the POE chains flanking the POP chains were very effective adjuvants for increasing antibody formation. They also activated complement and induced the release of chemotactic factors from serum. Increasing the percent of POE decreased adjuvant activity and inflammation. Decreasing the m.w. of the molecules while maintaining the proportions of POP and POE decreased the adjuvant activity and increased inflammation. Preparations synthesized in the reverse order, with the POP flanking POE, tended to induce granulomas instead of antibody. These data demonstrate that block copolymer surfactants have a spectrum of biologic activities that depend on the size and arrangement of their constituent parts. We suggest that much of the activity of these agents derives from their ability to form adsorptive surfaces similar to those of a mycobacterial glycolipid, quartz, and monosodium urate.

Adjuvants, Immunologic↗

Endotracheal intubation in the prehospital phase of emergency medical care.

One hundred seventy-eight endotracheal intubations by paramedics were reviewed prospectively during a nine-month period; 149 patients (83.7%) had medical conditions, and 29 (16.2%) had trauma. The endotracheal tube was successfully placed in 172 (96.6%); in four patients (2.2%), attempts were unsuccessful, and in two patients (1.1%), the attempt was aborted. There were no incidences of reported complications. We conclude that endotracheal intubation can be accomplished successfully outside the hospital by paramedical personnel. Comprehensive training and continuous medical control of paramedics' activities seem to be essential requirements for its success.

Adolescent↗

Cis-platin based combination chemotherapy for advanced ovarian cancer. High overall response rate with curative potential only in women with small tumor burdens.

Thirty-eight women with advanced ovarian cancer were given monthly cycles of intravenous cyclophosphamide, Adriamycin (doxorubicin) and cis-platin, and oral hexamethylmelamine. Of 26 with tumor which would be evaluated for response, 42% had complete remission and 50% partial remission. Median time to disease progression from entry for all 38 patients was 13 months, and median survival 23.5 months. The bulk of tumor at the time chemotherapy was begun was the only significant prognostic factor for time to disease progression and survival. Of the seven women surviving free of disease a median of three years later, five had no mass greater than 2 centimeters in diameter at entry. Toxicity was predominantly myelosuppression and vomiting, with mild peripheral neuropathy in 27% and no significant renal or cardiac toxicity. The response rate of 92% is much higher than that previously reported with melphalan, and the survival considerably longer. The toxicity is acceptable, given the substantial improvement in results.

Adult↗

Splenectomy and infection in Hodgkin's disease.

The incidence of infection in 56 patients with Hodgkin's disease who had undergone staging laparotomy with splenectomy was compared with that of 28 non-splenectomized patients with Hodgkin's disease treated concurrently. The results suggest that splenectomy does not result in a major change in the incidence of infection experienced by such patients with stage II or stage III disease. Aggressive therapy may be of greater importance in increasing the susceptibility to infection in Hodgkin's disease.

Adolescent↗