Safety of the antibody screening test as the sole method of pretransfusion testing.
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Blood Transfusion↗
Biomedical subjects
F López
Publications and source records attributed to F López.
Effect of arterial proteoglycans and glycosaminoglycans on low density lipoprotein oxidation and its uptake by human macrophages and arterial smooth muscle cells.
The reversible interaction of low density lipoprotein (LDL) with arterial chondroitin sulfate proteoglycans (CSPGs) or glycosaminoglycans (GAGs) selects LDL particles with a high affinity for sulfated GAGs and also induces modifications in apolipoprotein B (apo B) and the lipid organization of the lipoprotein. In the present work we studied the effect that the reversible interaction with sulfated polysaccharides has on the susceptibility of LDL to in vitro oxidation. For this purpose soluble, nonaggregated CSPG- or GAG-treated LDL was subjected to oxidation in the presence of 5 microM CuSO4 for as long as 48 hours. The rate of formation of thiobarbituric acid-reactive substances, the decrease in isoelectric point, the increase in relative electrophoretic mobility of LDL, the higher degradation rate by human macrophages, and the lower degradation rate by human arterial smooth muscle cells showed that LDLs exposed to CSPGs and GAGs were significantly more susceptible to oxidation than native LDL. Results from competition experiments indicate that C6S-treated LDL after 4 hours of oxidation is taken up via the acetylated LDL receptor in human macrophages. Coincubation of lipoproteins with human macrophages or human arterial smooth muscle cells for 24 hours also indicated that C6S-treated LDL was more susceptible to cell-induced modifications than native LDL. The occurrence in vivo of similar processes may contribute to focal retention, increased rate oxidation of LDL in the arterial intima, and foam cell formation during atherogenesis.
Arteries↗
Renal effects of prolonged synthesis inhibition of endothelium-derived nitric oxide.
The aim of the present study was to investigate in conscious dogs the long-term effects of nitric oxide synthesis inhibition on glomerular filtration rate, sodium and water excretion, and plasma levels of renin and aldosterone. After a control period of 3 days, an inhibitor of endothelium-derived nitric oxide synthesis, NG-nitro-L-arginine-methyl ester, was infused for 3 consecutive days at a dose (50 ng/kg/min) that did not induce significant changes in arterial pressure (n = 6). The inhibition of nitric oxide synthesis led to a large and sustained decrease (p less than 0.05) in glomerular filtration rate of approximately 35%. This change was accompanied by a decrease (p less than 0.05) in urinary sodium excretion from 78.9 +/- 4.6 meq/day to 49.8 +/- 6.8, 60.1 +/- 4.2, and 53.5 +/- 9.0 meq/day by days 1, 2, and 3 of nitric oxide synthesis inhibition, respectively. Changes in fractional sodium excretion failed to achieve statistical significance. Nitric oxide synthesis inhibition also induced a significant and sustained decrease in urine flow rate. The decrease in glomerular filtration rate, natriuresis, and diuresis was accompanied by a 45% increase in plasma renin activity (p less than 0.05) and no change in plasma aldosterone concentration. By day 3 of the recovery period, glomerular filtration rate, natriuresis, diuresis, and plasma renin activity returned to values similar to those found during the control period. The administration of L-arginine during 3 consecutive days (5 micrograms/kg.min i.v.) did not modify any of the parameters measured but effectively prevented all the renal changes induced by the 3 days of nitric oxide synthesis inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)
Aldosterone↗
[The cytogenetics of premature ovarian failure].
Premature ovarian failure is defined as the occurrence of menopause before the age of 40 years. Etiology has been related to genetic, autoimmune or infectious factors, resistance to gonadotropins and others. Forty-seven patients with this diagnosis were referred for cytogenetic analysis. Sixty-eight percent of the cases had a normal karyotype. In 10.7% there was one 45,X cell and they were catalogued as normal. In 15% of the patients there was a mosaicism with normal cell lines and additional 45,X, 47,XXXX and 48,XXXX ones. Two women had a chromosomal constitution 47,XXX. In one 22-year old patient there was a reciprocal balanced translocation 46,X t(X; 18) (q21.2;q22). The presence of different cell lines, including 45,X cells, could explain an accelerated loss of gametes in the ovary. In women with 47,XXX karyotype, fertility problems and premature menopause have been described. The study of the balanced X-autosome translocation with DNA technics could allow to find the molecular basis of the ovarian failure, permitting the direct search of the gene involved at the site of disruption.
Adolescent↗
Long-term acyclovir prophylaxis for prevention of varicella zoster virus infection after autologous blood stem cell transplantation in patients with acute leukemia.
Twenty-one adult patients with acute leukemia who underwent autologous blood stem cell transplantation (ABSCT) and who received acyclovir during the first 6 months after transplant to prevent varicella zoster virus (VZV) infection were studied retrospectively to determine the incidence and outcome of VZV infection after ABSCT. The cumulative risk of VZV infection was 32% by 1 year after transplant. No patient developed VZV while on prophylactic acyclovir but five (24%) had localized herpes zoster within 1 month of acyclovir withdrawal. There were no deaths related to VZV infection and only one patient had disseminated disease and post-herpetic neuralgia. These preliminary results suggest that the incidence and outcome of VZV infection after ABSCT largely parallel those reported in marrow transplant patients and that long-term acyclovir prophylaxis delays but does not prevent VZV infection. Prophylaxis of VZV infection after ABSCT requires new therapeutic approaches.
Acyclovir↗
[Infections in the diabetic. Comparative study of infections in the foot and other locations].
Given the high morbi-mortality of foot infections among the diabetics and the poor knowledge of their predictive, clinical and evolutive factors, we have retrospectively studied a group of patients with these characteristics, comparing them with infections among diabetics affecting other locations. We studied 66 infections among diabetics: 34 patients with diabetic's foot and 32 with infections at other locations: 20 pyelonephritis and 12 pneumonias. Medical records were obtained in all cases and all patients underwent a complete physical exploration in order to assess their risk factors. We observed as a significant predictive factor of diabetic's foot, diabetes type I, with an evolution longer than 10 years, neuropathy, vasculopathy or retinopathy. From the clinical point of view and compared with the other infections, these patients showed longer hospitalization, greater initial clinical severity, glucemias higher than 200 mgr/l., anemia and high GSR. Ethiologically, the infection of diabetic's foot was polymicrobian in 42.3% of all cases, being S. aureus the microorganism more frequently isolated. On the contrary, in infections at other locations, monomicrobian flora was more frequent, being E. coli the most frequent in pyelonephritis and S. pneumoniae in pneumonias. The evolution was satisfactory in all cases, with a close medical and surgical combined treatment and the appropriate use of antibiotic combinations, mainly clindamicine + tobramicine in the diabetic's foot and cefuroxime in the other locations.
Bacterial Infections↗
Modifications of low-density lipoprotein induced by arterial proteoglycans and chondroitin-6-sulfate.
Association of low-density lipoproteins (LDL) with arterial chondroitin sulfate proteoglycans (CSPG) appears to contribute to their deposition in the extracellular intimal compartment and to its internalization by macrophages. CSPG and LDL interact by ionic bridges with formation of soluble and insoluble complexes. We studied the alterations on LDL structure induced by its association with arterial CSPG and other glycosaminoglycans (GAG). In soluble complexes, at low and at physiological ionic strength, arterial CSPG and sulfated GAG modify the kinetics of apoB-100 proteolysis by trypsin. However, less marked alterations in the peptide patterns were observed with proteinase V8 and almost none with thermolysin. This is indirect evidence that the presence of CSPG and GAG modified the exposure of polar regions of apoB-100 in LDL. Competitive binding experiments with agarose-bound heparin and soluble GAG also suggest that after formation of insoluble complexes with arterial CSPG and resolubilization the exposure of Lys, Arg-rich segments of apoB-100 is increased. Results from differential scanning calorimetry and differential thermal spectrophotometry showed that the CSPG and GAG-induced modifications reduced the thermal stability of the surface and core in LDL. If present in vivo, the structural alterations of polar segments of the LDL protein moiety may influence the outcome of its interaction with the arterial mesenchyma.
Apolipoprotein B-100↗
Arachnoid cyst as a complication of ventricular shunting.
Overdrainage of cerebrospinal fluid (CSF) is a well-known complication of shunting procedures. Several clinical manifestations of excessive drainage of CSF have been documented, such as subdural hematoma, subdural effusions, slit ventricles, isolated IV ventricle, etc. To the authors' knowledge, this is the first report of an arachnoid cyst due to the excessive function of a VP shunt.
Arachnoid Cysts↗
Morphometric data on the arterial duct in the human fetal heart.
In a total of 496 fetuses and newborns ranging in body weight from 60 to 5000 g, we performed a morphometric study of the ascending aorta, the descending aorta, the aortic isthmus, the right pulmonary artery, the left pulmonary artery and the arterial duct. In all, nine different parameters were measured in each specimen. The variations in the correlations between two measurable characteristics, namely body weight and each of the morphometric parameters, were analyzed. The minimum, normal and maximum patterns of normality for each parameter were obtained with regression equations. We compared statistically the diameter of the arterial duct with the diameter of the ascending and descending aorta, the aortic isthmus, the right pulmonary artery and the left pulmonary artery with one way analysis of variance, using Bonferroni's test in the pairwise comparisons. The diameter of the arterial duct was smaller than the diameter of the ascending and descending aortas, the aortic isthmus, the right pulmonary artery and the left pulmonary artery, and the diameter of the ascending aorta was larger than that of the descending aorta. These morphological data have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.
Aorta↗
The effect of dihydropyridine calcium channel agents on 5-HT metabolism in the CNS of the rat.
The effects of dihydropyridines on the levels of 5-hydroxytryptamine (5-HT) and 5-hydroxy-3-indole acetic acid (5-HIAA) in the spinal cord and various brain regions of the rat have been studied. Nimodipine, nitrendipine and nifedipine (10 mg kg-1), nisoldipine (5 mg kg-1), and BAY K8644 (0.2 and 2 mg kg-1) were administered i.p. 1 h before killing. The administration of nifedipine and nitrendipine increased 5-HT turnover in all of the areas studied except for the spinal cord. Nisoldipine increased 5-HT turnover in midbrain, hippocampus and cortex, while the effect of nimodipine was restricted to midbrain. BAY K8644 at 2 mg kg-1 produced the same effects as nifedipine and nitrendipine; however, at low doses (0.2 mg kg-1), this compound increased 5-HT turnover only in midbrain and medulla oblongata. These results indicate that both dihydropyridine calcium channel agonist and antagonists are able to activate the 5-HT-ergic system in the central nervous system of the rat in-vivo. Therefore, it seems likely that such effects could be due to indirect actions or to interactions of the compounds with receptors other than the voltage-sensitive calcium channels.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
[Harvesting of mononuclear cells from peripheral blood in malignant hemopathies].
After demonstrating through animal models that progenitor cells with haemopoietic regenerative capability are present in peripheral blood, such precursor cells were also found in the mononucleated cell (MNC) fraction of human peripheral blood. It was shown that such cells increase in the recuperative period following chemotherapy. A number of studies have demonstrated that autologous infusion of such MNC achieved by cytapheresis may lead to a quick restoration of haemopoiesis. The initial results of peripheral blood MNC achievement in 18 patients with different malignancies of the blood are presented in this paper. Ninety-one cytapheresis sessions were carried out, 88 with a Fenwall CS-3000 continuous-flow machine, and the remaining three with a Haemonetics V-50 discontinuous-flow cell separator. The number of sessions per patient ranged from three to six and the harvested MNC count was 19.3 x 10(9)/L, the percentage of recovery being 56.4%. Some studies are currently in course aimed to analyse the MNC subpopulations in order to measure the progenitor-cell fraction and to establish the viability of such cells for further transplants. Since only five patients have recently been transplanted, all successfully, no definite conclusions can be drawn presently in this connection.
Adolescent↗
[Chronic lymphatic leukemia. I. Clinico-biological features and survival analysis. Study of 187 patients].
A review was carried out of 187 previously untreated cases of chronic lymphocytic leukaemia diagnosed between 1969 and 1988. The median age of the patients was 65 years (range, 36-87). There were 118 males (M/F ratio, 1.7). In accordance with Rai's staging system the patients were distributed as follows: 0.29%; I, 20%; II, 25%; III, 13%; IV, 13%, and according to Binet's staging the distribution was: A, 55%; B, 21%; C, 24%. The most frequently found physical findings were lymph node enlargement (55%), splenomegaly (32%) and hepatomegaly (28%). Anaemia was present in 20% of the cases and thrombocytopenia in 13%. The mean lymphocyte count was 62 x 10(9)/L (range, 6-475 x 10(9)/L). Bone marrow infiltration of over 80% was seen in 46% of the patients. Bone marrow biopsy was performed on 97 patients, the diffuse pattern of involvement being most commonly found (44%). Increased BUN (55%), alkaline phosphatase (42%) and LDH (38%) were the most frequent biochemical alterations. Hypogammaglobulinaemia was present in 55% of the patients, IgM being the most commonly affected immunoglobulin (66%). Monoclonal gammopathy was seen in 4% of the cases. LDT, measured in 75 patients, was less than a year in 32%. No antileukaemic drugs were needed in 34% of the patients. When concluding this study, 100 patients had died. The median survival was 57 months and death was related to chronic lymphocytic leukaemia in 53% of such patients.
Actuarial Analysis↗
[Chronic lymphatic leukemia. II. Analysis of prognostic factors and development of survival predicting models. Study of 187 patients].
The univariate analysis of prognostic factors showed the value of clinical variables (age, symptoms, lymph node enlargement, splenomegaly, hepatomegaly, clinical stage), haematological variables (haemoglobin, platelet count, leucocyte count, lymphocyte count, bone marrow involvement and biopsy pattern, cleaved lymphocytes, prolymphocytes, LDT) and biochemical variables (BUN, creatinine, calcium, phosphorus, uric acid and albumin). The multivariate analysis chose the combination of Rai's stage, age, cervical lymph node involvement, phosphorus and BUN. Two predictive models capable of separating appropriately low, intermediate and high risk groups were developed and validated. The results were compared with others in the literature. The interest of predictive models arising from multivariate analysis is stressed.
Adult↗
[Subacute sclerosing panencephalitis of long course].
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Child↗
Modification of copper-catalyzed oxidation of low density lipoprotein by proteoglycans and glycosaminoglycans.
Chondroitin sulfate proteoglycans (CSPG) appear to contribute to retention of low density lipoproteins (LDL) in atherosclerotic lesions. In vitro, CSPG and glycosaminoglycans (GAG) modify LDL structure and increase its uptake by macrophages. This latter effect appears related to increased exposure of arginine- and lysine-rich segments of apoB-100. We explored whether alterations of LDL induced by human arterial CSPG and purified GAG alter the lipoprotein susceptibility to transition metals-catalyzed oxidation. Human LDL was complexed with human arterial CSPG and dissociated by raising the ionic strength. The nonaggregated, CSPG- and GAG-treated LDL was subjected to oxidation by micromolar amounts of Cu+, Cu2+, Fe2+, and Fe3+. This treatment increased LDL susceptibility to Cu2+ oxidation 3- to 5-times, as indicated by the degradation rate of phospholipids and cholesteryl esters and formation rates of dienes and thiobarbituric acid-reacting substances (TBARS). Also, human macrophages degraded the CSPG-treated, Cu2+-oxidized LDL 3- to 6-times faster than native LDL similarly treated. No enhancement of oxidation was observed with Fe2+, Fe3+, and Cu+. Quenching of the LDL intrinsic fluorescence by Cu2+ showed that heparin, CSPG, and chondroitin-6-SO4 pretreatment increased the access of Cu2+ to hydrophobic chromophores, probably tryptophan, 6- to 7-, 3- to 4-, and 2- to 3-fold, respectively. Also, the affinity constant (Ka) of LDL for Cu2+ was increased from 0.12 microM to 0.20 microM by the treatment with CSPG and GAG. These results and evaluation of the fraction of surface-accessible LDL chromophores to acrylamide quenching suggest that the increased susceptibility to oxidation may be associated with an increase in the access of Cu2+ to hydrophobic regions in LDL caused by treatment with CSPG and GAG. This effect was not detected with Cu+, Fe2+, or Fe3+. The phenomenon may contribute to acceleration of the oxidative modifications of LDL in cell culture models and in vivo.
Aorta↗
[Duodenal villous adenoma. Report of 2 cases].
The case history, diagnosis and management of 2 pts with villous adenoma of the duodenum are reported. Both were operated on with good results, with no relapse at 12 and 18 months of observation. This tumor which is more frequently located in the vicinity of the Vater Ampullae, has a low incidence. One third of them have malignant elements raising an issue on therapeutic options. Literature is reviewed with special emphasis on the type of surgical resection to be used.
Adenoma↗
[Ileorectal anastomosis: results of surgical treatment and evaluation of the intestinal function].
Ileo-rectal anastomosis was performed in 30 patients. Indication for surgery was ulcerative colitis in 12, cancer of colon in 10 and megacolon in 6. Mean age of patients was 47.8 years with an even sex distribution. Ileo-rectal anastomosis was performed simultaneously with total colectomy in elective patients (n = 18) and at a second stage, following transient terminal ileostomy in emergency cases (n = 12). An overall morbidity of 26% was observed: wound infection developed in 13%, prolonged ileus in 7%, intraabdominal abscess in 3% and fistula of the anastomosis in 3%. There was no mortality. After a mean follow up of 36 months there was no instance of incontinence, average number of daily intestinal evacuations was 2.4 (somewhat higher for patients with ulcerative colitis: 2.6 vs 2.1). We conclude that ileo-rectal anastomosis is a safe procedure with adequate functional results.
Adolescent↗