Effect of 1,5-benzodiazepine derivatives on sleep.
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Biomedical subjects
Publications and source records attributed to E Campos.
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This study determines whether a genetically engineered mutant of Brucella abortus, strain M-1, possesses differences in protective properties compared to the parental strain, vaccine S19. M-1 is a mutant unable to express BP26, a periplasmic protein with potential use in diagnosis. Mice vaccinated with S19 developed antibodies against BP26, while those vaccinated with M-1 did not. However, mice vaccinated with S19 or M-1 were similarly protected against challenge with pathogenic strain 2308, suggesting that the lack of BP26 does not affect the induction of the protective immune response exerted by S19. These and previous results showing that bacterial invasion and growth or replication in mouse spleens were indistinguishable between strains M-1 and S19 could indicate that the mutant is an attenuated strain which maintains the same protective properties as S19.
The human placental microvillar membrane contains several ectoenzymes, including 5'-nucleotidase, alkaline phosphatase and ATP-diphosphohydrolase (ATP-DPH), which might be involved in the extracellular metabolism of nucleotides. The type of anchorage to the plasma membrane of the two first enzymes has been shown to be via a glycosyl-phosphatidylinositol. In the present study, using an enzymatic approach, we show that the ATP-DPH should be attached to the plasma membrane through a different type of anchorage. We were also interested in the search of compounds which could interact differentially with this enzyme to be used as a tool for studying the other two hydrolytic enzymes in the presence of ATP-DPH. Here we report several inhibitors of ecto-ATPases which seem to be a useful tool for studying these three enzymes.
Lipoprotein(a) is one of the best examples of heterogeneity of lipoproteins. It presents pre-beta electrophoretic mobility in agarose gel, similar to Very Low Density Lipoproteins, it is found in High Density Lipoproteins due to its hydrated density greater than 1,063 and resembles Low Density Lipoproteins in its size and lipid composition. However, Lp(a) is unique in that it contains an additional distinct antigen, the apo(a), attached to apoB100 by one disulphide bridge. The apo(a)-glycoprotein has recently been shown to have a striking amino acid sequence homology with plasminogen; Lp(a) seems to be a potential bridge between atherosclerosis and thrombosis fields and interest in Lp(a) has greatly increased since then. The new knowledge on the structure of Lp(a) being more and more rapidly acquired should facilitate our understanding of the mechanisms of its atherogenicity and its physiopathological role. Metabolic studies have made it clear that Lp(a) is not a product derived from other apoB-containing lipoproteins, but is secreted by the liver as a distinct mature lipoprotein. Concerning the immunological techniques available to assay Lp(a) they need to be standardized and it is still necessary to define what is meant by the pathological threshold for Lp(a), which will certainly depend on the choice of the standard antiserum and immunological method used.
Recurrent ocular herpes is an insoluble problem for the clinician. As cellular immunity plays an important role in controlling herpes relapses, and other studies have shown the efficacy of HSV-specific transfer factor (TF) for the treatment of herpes patients, an open clinical trial was undertaken in 134 patients (71 keratitis, 29 kerato-uveitis, 34 uveitis) suffering from recurrent ocular herpetic infections. The mean duration of the treatment was 358 days, and the entire follow-up period 189,121 before, and 64,062 days after TF treatment. The cell-mediated immune response to the viral antigens, evaluated by the lymphocyte stimulation test (LST) and the leucocyte migration test (LMT) (P < 0.001), was significantly increased by the TF treatment. The total number of relapses was decreased significantly during/after TF treatment, dropping from 832 before, to 89 after treatment, whereas the cumulative relapse index (RI) dropped, during the same period, from 13.2 to 4.17 (P < 0.0001). No side effects were observed. It is concluded that patients with relapsing ocular herpes can benefit from treatment with HSV-specific TF.
Clinical and epidemiological characteristics of diarrhea associated with Vibrio mimicus were identified in 33 hospitalized patients referred to the Costa Rican National Diagnostic Laboratory Network between 1991 and 1994. The relevant symptoms presented by patients included abundant watery diarrhea, vomiting, and severe dehydration that required intravenous Dhaka solution in 83% of patients but not fever. Seroconversion against V. mimicus was demonstrated in four patients, from whom acute- and convalescent-phase sera were obtained. Those sera did not show cross-reaction when tested against Vibrio cholerae O1 strain VC-12. All the V. mimicus isolates from these cases produced cholera toxin (CT) and were susceptible to commonly used antibiotics. Attempts to isolate this bacterium from stool samples of 127 healthy persons were not successful. Consumption of raw turtle eggs was recalled by 11 of the 19 (58%) individuals interviewed. All but two V. mimicus diarrheal cases were sporadic. These two had a history of a common source of turtle (Lepidochelys olivacea) eggs for consumption, and V. mimicus was isolated from eggs from the same source (a local market). Among the strains, variations in the antimicrobial susceptibility pattern were observed. None of the strains recovered from market turtle eggs nor the four isolates from river water showed CT production. Further efforts to demonstrate the presence of CT-producing V. mimicus strains in turtle eggs were made. Successful results were obtained when nest eggs were tested. In this case, it was possible to isolate CT- and non-CT-producing strains, even from the same egg. For CT detection we used PCR, enzyme-linked immunosorbent assay (ELISA), and Y-1 cell assay, obtaining a 100% correlation between ELISA and PCR results. Primers Col-1 and Col-2, originally described as specific for the V. cholerae O1 ctxA gene, also amplified a 302-bp segment with an identical restriction map from V. mimicus. These results have important implications for epidemiological surveillance in tropical countries where turtle eggs are used for human consumption, serving as potential sources of cholera-like diarrhea.
We have isolated two fractions of very low density lipoprotein particles in human plasma that lack apolipoprotein (apo) E by combined anti-apoE and heparin affinity chromatography of whole plasma followed by ultracentrifugation. The two fractions are distinguished by their ability to bind to heparin. Each of these fractions, designated "B" particles to distinguish them from very low density lipoproteins that contain apoE ("B,E" particles), comprises an appreciable fraction of total particles in very low density lipoproteins of normolipidemic and hypertriglyceridemic subjects. The heparin-unbound B particles, which have been reported previously by others, are larger and have negligible affinity for low density lipoprotein receptors. The heparin-bound B particles are smaller and do bind to low density lipoprotein receptors, albeit with much lower affinity than B,E particles. No differences in accessibility to limited protease digestion were found between apoB-100 in the two types of B particles. Our data indicate that a substantial fraction of human very low density lipoproteins lacks apoE, the principal ligand for lipoprotein receptors that mediate the terminal catabolism of these lipoproteins. Whereas the B particles that fail to bind to heparin are likely to represent a form of nascent lipoprotein, the origin of those B particles that bind to heparin remains to be determined.
Micronuclei (MN) induction by carboplatin, cis-diammine-1,1-cyclobutane decarboxylate platinum (II) (CBDCA), in B and T lymphocytes was studied by the MAC (morphology/antibody/chromosome) method which allows the immunologic identification of different cell lineages. An increased frequency of MN in B and T lymphocytes in CBDCA-treated cultures compared with controls was observed (p < 0.001). CBD cells were found to be more sensitive to CBDCA damage. CBDCA-treated cultures showed a decrease, albeit statistically non-significant, in the proportion of CBD interphasic and mitotic cells. Furthermore, higher MN frequencies in isolated lymphocytes than in whole blood in both control and CBDCA-treated cultures were observed.
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A routine electrophoretic method detecting plasma lipoprotein(a) (Lp(a)) is described. Plasma lipoproteins were electrophoresed using an agarose gel film containing cations which retard migration of beta-, prebeta- and alpha-bands. When present, the Lp(a)-band was detected between prebeta- and alpha-bands. This extra-band lipoprotein has been demonstrated to be Lp(a), by an immunofixation technique using anti-Lp(a) antibodies. This original procedure allows a distinct separation of Lp(a) from prebeta even after samples have been stored at 4 degrees C for several days, or in cases of hyperlipemic samples with increased prebeta lipoproteins. The reliability of this detection test has been tested in comparison with an Lp(a) electroimmunoassay. Both these techniques have been performed on 719 randomly selected subjects. With electrophoresis, the Lp(a)-positive subjects accounted for 34.2% of the subjects and although this method does not distinguish between different levels of positivity (depending on the sample), the presence of Lp(a)-band was always perceptible at concentrations that belong to the upper 15th percentile of values as determined by electroimmunodiffusion; inversely, all Lp(a)-positive plasma was measurable. In consequence, since it is reliable and relatively inexpensive, this detection test on modified agarose gel appears very useful for revealing the presence of abnormally high values of Lp(a) in populations.
We have developed a simple, rapid assay method for apo E-rich lipoproteins (d < 1.006 g/ml), using an immunoaffinity gel mixture of anti apo B-100 and apo A-I antibodies coupled to Sepharose 4B. The immunoaffinity mixed gels adsorb normal lipoproteins containing apo A-I quantitatively as well as most lipoproteins containing apo B-100. Unbound lipoproteins are quantified by assay of cholesterol. Characterization of the unbound lipoproteins of d < 1.006 g/ml (J Lipid Res 1992; 33: 369-380) has shown that they represent chylomicron and VLDL remnant-like particles (RLP). RLP-Cholesterol(C) levels in plasma have been determined in 363 male and female normolipidemic subjects (mean +/- S.D.: 72 +/- 16 mg/l) and have been found to be higher in patients with coronary heart disease and familial dysbetalipoproteinemia. Triglyceride-rich lipoproteins may well contain both atherogenic and non-atherogenic particles that can be separated by this simple immunoadsorption assay.
Information about Mycoplasma pneumoniae infections in tropical countries is scarce. This study reports the prevalence of anti-M. pneumoniae antibodies among schoolchildren from the tropical community of Palmares, Costa Rica. The serum samples were collected in July 1983 from 2021 children who represented 99% of the county's schoolchildren. Immunofluorescence (IFA) and in some cases ELISA serological methods were applied. IFA seropositivity was high (53%) and ranged from 22% to 79% depending on the district. Marked differences in the prevalence of antibodies in children attending schools of neighboring communities, suggest that the school may be epidemiologically important as a focus to spread mycoplasma infections among children. The presence of a low percentage of antibodies (IgG, IgM and IgA) against the 168 kd- M. pneumoniae antigen suggested that there were few cases of active or recent infections.
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The aim of this study was to evaluate the ATB 32 C (API system) automatic medium for identifying yeasts in clinical samples. A total of 101 yeasts strains were studied, representing 8 genera and 18 different species, identified by conventional means. All 32 microdomes of the track, including dehydrated substrates, were inoculated in a semi-solid media (C medium). After their incubation at 30 degrees C for 48 hours, the reading device ATB 1520 and the computer of ATB system the reading and automatic interpretation of the results. Using the ATB method, 85 strains were identified (84%) at species level, 9 at genus level and a non-conclusive or unacceptable profile was recorded in 7 strains. From all clinically important yeasts species, a total of 96% were identified by ATB method according to conventional methods. From all non clinically relevant species, ATB 32 C identified correctly 23 strains (78%). ATB 32 C method is a good alternative approach to conventional techniques for identifying yeasts in clinical samples.
A monoclonal antibody to apolipoprotein (apo) B-100 (JI-H) with unique binding properties has been used to separate a population of triglyceride-rich lipoproteins from blood plasma of normotriglyceridemic individuals and patients with various forms of hypertriglyceridemia. This antibody fails to recognize an apoE-rich population of very low density lipoproteins (VLDL) containing apoB-100 as well as all triglyceride-rich lipoproteins containing apoB-48, but it binds other VLDL that contain apoE and almost all lipoproteins that contain apoB-100, but no apoE. The unbound triglyceride-rich lipoproteins separated by ultracentrifugation after separation from plasma by immunoaffinity chromatography contained 10-13% of the apoB of triglyceride-rich lipoproteins from three normotriglyceridemic individuals, 10-29% of that from five patients with endogenous hypertriglyceridemia, 40-48% of that from three patients with familial dysbetablipoproteinemia, and 65% of that from a patient with lipoprotein lipase deficiency. In all cases, the unbound triglyceride-rich lipoproteins contained more molecules of apoE and cholesteryl esters per particle than those that were bound to monoclonal antibody JI-H, and they were generally depleted of C apolipoproteins. These properties resemble those described for partially catabolized remnants of chylomicrons and VLDL. The affinity of the unbound lipoproteins for the low density lipoprotein (LDL) receptor varied widely, and closely resembled that of the total triglyceride-rich lipoproteins from individual subjects. Our results demonstrate that remnant-like chylomicrons and a population of remnant-like VLDL can be isolated and quantified in blood plasma obtained in the postabsorptive state from normotriglyceridemic and hypertriglyceridemic individuals alike.
We assayed clinically and experimentally a rapid method for detection of Candida in vagina by slide latex agglutination test (SLA). A total of 50 vaginal swabs from women with clinical evidence of candidiasis were examined for yeast by microscopical examination, mycological culture and compared with the Candida antigen test. We also studied experimentally the sensibility of the SLA test. We found better results with SLA than microscopy for rapid diagnosis. Of the women with certain vaginal candidiasis, 60% were diagnosed by microscopy and 100% by SLA. SLA provided similar information than culture, but is faster and the clinician can use its information choosing the appropriate antifungal treatment.
A new treatment of frontal sinus hypertrophy is described. The anterior wall is removed, inverted, and attached again. The resulting depression is filled with bone dust. Details are discussed, and a case is presented.
A total of 94 clinical isolates of the Bacteroides fragilis group was tested for susceptibility to metronidazole, chloramphenicol, clindamycin, cefoxitin, cefotetan, cefmetazole, moxalactam, mezlocillin, amoxicillin-clavulanic acid, and imipenem. All the strains tested were susceptible to imipenem, metronidazole, amoxicillin-clavulanic acid, and chloramphenicol. The rate of resistance to clindamycin was 21%. The results of this study demonstrate a difference in resistance rates from one species of the B. fragilis group to another.