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M García

Publications and source records attributed to M García.

At least 235 records · Page 13Linked to original sources
PubMed1995

[Sensitivity of yeast isolates to amphotericin B and other antifungal inhibitors of beta-glucan synthesis].

BACKGROUND: Analysis of the in vitro sensitivity of clinical isolates of different yeast species to amphotericine B and two inhibitors of cell wall beta-glucane synthesis: the lipopeptide cilofungin and the liposaccharide papulacandin B, as well as the possible interactions among these antifungal types. METHODS: The in vitro sensibility of C. albicans strains and other yeast species of clinical origin was studied, using the macrodilution method in RPMI broth as recommended by NCCLS. In six C. albicans and two T. glabrata strains the interaction between amphotericine B and one of the beta-glucan inhibitors was also assessed, by combining one antifungal agent in a two-fold dilution series with subinhibitory concentrations (1/4MIC) of the second antifungal. RESULTS AND CONCLUSIONS: Of all three antifungals, amphothericine B proved to be the more active one, with a MIC90 of 1.25 micrograms/ml for C. albicans. MIC90 of cilofungin and papulacandine B is 5 micrograms/ml for both antifungals. The spectrum of action for the different yeast species is broader for papulacandin B than for cilofungin. On the other hand, no synergism has been observed between the two glucane inhibitors and amphotericine B.

Aminoglycosides↗
PubMed1995

[Evaluation of specificity of pneumococcal antigen detection in clinical samples by using the polymerase chain reaction as reference method].

BACKGROUND: Sensitivity and specificity of latex agglutination test on samples obtained by transthoracic needle aspiration was evaluated for diagnosis of pneumococcal pneumonia by using the polymerase chain reaction as reference method. METHODS: Samples from 29 patients with community acquired pneumonia were processed for culture, antigen detection and polymerase chain reaction. The latex agglutination test was performed with a reagents kit (Slidex méningite kit, BioMérieux, France) using the procedure recommended by the manufacturer. The polymerase chain reaction was carried out by using two primers: Pn2x up and Pn2x down that amplify the PBP2x gene of Streptococcus pneumoniae. RESULTS: Culture was positive in 5 patients, antigen detection in 15 and polymerase chain reaction in 14 patients. The specificity of latex agglutination test was 93% compared with polymerase chain reaction as reference method. CONCLUSION: The pneumococcal antigen detection by latex agglutination test is as sensitive as the polymerase chain reaction, it seems to be highly specific, and it is rapid and easy to perform.

Antigens, Bacterial↗
PubMed1995

[Annual frequency of Cryptosporidium parvum infections in children and adult outpatients, and adults infected by HIV].

We report the analysis of 4892 parasitological stool samples coming from outpatients and patients of a nutritional recuperation center of north Santiago. Cryptosporidium parvum was detected in 21 samples (0.4%). The protozoan was detected in 6 of 1203 samples from children of less than 2 years old, 3 of 1.727 samples from children between 6 and 15 years, none of 776 samples from healthy adults and 2 of 13 samples from HIV infected patients. Nine of 97 children of less than 2 years old, hospitalized in the nutritional recuperation center, were infected with Cryptosporidium; this frequency was significantly higher than that of outpatients of the same age. Most infections were detected from May to August, a rainy and mildly cold period. It is concluded that Cryptosporidium infections are infrequent in healthy outpatients and that its prevalence increased in hospitalized children and HIV infected adults.

Acquired Immunodeficiency Syndrome↗
PubMed1994

The disulfide bridges of toxin 2 from the scorpion Centruroides noxius Hoffmann and its three-dimensional structure calculated using the coordinates of variant 3 from Centruroides sculpturatus.

The disulfide bridges of toxin 2 from the venom of the scorpion Centruroides noxius Hoffmann were found by amino acid sequence determination of fragments of native toxin, produced by enzymatic cleavage and separated by high-performance liquid chromatography (HPLC). They are: Cys12-Cys65, Cys16-Cys41, Cys25-Cys46 and Cys29-Cys48. The coordinates of the X-ray diffraction structure of toxin variant 3 of C. sculpturatus [(1980) Proc. Natl. Acad. Sci. USA 77, 6496-6500] were used to construct a three-dimensional model of toxin 2. All the amino acid replacements were easily accommodated, and the modeled structure reveals a clustered pattern of sequence variation, which may help to identify residues responsible for functional differences among toxins of mammals and insects.

Amino Acid Sequence↗
PubMed1994

Prospective study of infection, colonization and carriage of methicillin-resistant Staphylococcus aureus in an outbreak affecting 990 patients.

In the three years between November 1989 and October 1992, an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) affected 990 patients at a university hospital. The distribution of patients with carriage, colonization or infection was investigated prospectively. Nosocomial acquisition was confirmed in at least 928 patients, 525 of whom were identified from clinical specimens as being infected (n = 418) or colonized (n = 107) by MRSA. An additional 403 patients were identified from screening specimens, of whom 58 subsequently became infected and 18 colonized. Screening of the nose, throat and perineum detected 98% of all carriers. Of the 580 infections in 476 patients, surgical wound, urinary tract and skin infections accounted for 58% of the infections. Of the 476 infected patients, death was attributable to MRSA infection in 13%. Colonization with MRSA was found in 127 patients and 42% of 165 colonized sites were the skin. Auto-infection from nasal carriage or cross-infection, probably via staff hands, seemed to be the most common mode of acquisition of MRSA infections.

Adolescent↗
PubMed1994

Analysis of the variability in expression of Mycoplasma gallisepticum surface antigens.

The in vitro expression of surface epitopes for different strains of Mycoplasma gallisepticum (MG) was studied with a panel of monoclonal antibodies (mAbs) using indirect colony immunostaining and Western blot (WB) analyses. Immunostaining of colonies with mAbs showed that five epitopes had different degrees of variable expression, while one epitope was permanently expressed in vitro. Colonies that failed to express the studied epitopes had the potential of phenotypically switching the expression of these epitopes in vitro. Variable and permanently expressed epitopes were associated with more than one protein and not all mAb-defined proteins were responsible for the immunostaining of intact MG colonies. The ability of MG to variably express their surface epitopes maybe the mechanism utilized by the microorganism to avoid the host immune response.

Animals↗
PubMed1994

Toxicity of policosanol in beagle dogs: one-year study.

Policosanol is a new chemical entity composed of 8 higher aliphatic alcohols obtained from sugar cane (Saccharum officinarum), L. wax, whose cholesterol-lowering effects have been demonstrated in experimental models, healthy volunteers and patients with type II hypercholesterolemia. This study investigated the oral toxicity of policosanol administered for 52 weeks to beagle dogs. Twenty-four beagle dogs (12 males and 12 females) were distributed randomly in 3 experimental groups (4 animals/group): a control and 2 treated groups receiving policosanol at 30 and 180 mg/kg daily (7 days/week) by gavage. No mortality was observed in any group. Overall, policosanol was well tolerated throughout the study and no toxic symptoms were observed. All groups showed similar weight gain and food consumption. Lipid profile determinations showed that policosanol decreased total cholesterol by 20% approximately from 8 to 52 weeks. Cholesterol-lowering effects did not wear off during the study, thus demonstrating the persistence of the effectiveness. Triglycerides and high density lipoprotein-cholesterol (HDL-C) were not changed significantly. No blood biochemistry or histopathological disturbances attributable to treatment were observed. This study has shown that no drug-related toxicity was induced by policosanol administered up to 180 mg/kg/day for 52 weeks to beagle dogs. Since this dose is approximately 620 times higher than the maximal recommended therapeutic dose (20 mg/day) it indicates a good safety margin of this product.

Administration, Oral↗
PubMed1994

Cells surrounding haemodialysis-associated amyloid deposits are mainly macrophages.

Dialysis-related amyloidosis is a type of amyloidosis which had beta 2-microglobulin as the major protein constituent and occurs predominantly in haemodialysis patients. Its prevalence is very high with increasing time on dialysis treatment and its pathogenesis is not completely understood. While remarkable progress has been made in the identification of the components of the deposits, there are no reports characterizing the cells surrounding the amyloid fibrils. To characterize the cellular composition of the amyloid material, specimens from seven patients treated by maintenance haemodialysis were studied with immunoperoxidase labelling using monoclonal antibodies to leukocytes (CD3, CD14, CD68, CD4, CD8, CD45). The results were very reproducible for the seven deposits assessed: Of the 182 +/- 26 leukocytes/0.2 mm2 of amyloid tissue expressing the 71.5-CD45 marker (common leukocyte), 91 +/- 6% were CD68 (KP1) positive (monocyte macrophage). No CD3-positive cells (T-cell marker) were found in six of the seven patients, with only 1.6% in the remaining one. The present study shows that although amyloidosis has classically been considered as an acellular pathology, clearly there are cells surrounding amyloid fibrils. Strikingly, these cells are almost exclusively macrophages; there are no lymphocytes or granulocytes. The putative role of macrophages in the pathogenesis of beta 2-microglobulin amyloidosis remains to be established. However, the identification and quantitation of the cells surrounding the amyloid deposits may be important for subsequent studies to elucidate amyloid pathogenesis and particularly protein-cell interactions.

Adult↗
PubMed1994

Autoradiographic study of hyphal growth during aerial mycelium development in Streptomyces antibioticus.

The pattern of growth of aerial mycelium in Streptomyces species was investigated by autoradiography. Colonies of Streptomyces antibiotics were labeled with N-acetyl-D-[1-3H] glucosamine to localize the sites of hyphal growth during the development of aerial mycelium. Autoradiographs obtained with sections of the colonies revealed that hyphal growth occurs not only at the top of the colony but also in the inner zones of the aerial mycelium.

Acetylglucosamine↗
PubMed1994

Transthoracic needle aspiration in the study of pulmonary infections in patients with HIV.

STUDY OBJECTIVE: To evaluate the safety and efficacy of transthoracic aspiration with an ultrathin needle in the microbiologic diagnosis of pulmonary infections in HIV-infected patients. DESIGN: Retrospective review of cases. SETTING: A 500-bed teaching hospital in Lleida, Spain. PATIENTS: Forty-five HIV-infected patients admitted between March 1989 and March 1993 with clinical and roentgenographic evidence of pulmonary infection and without contraindications for transthoracic needle aspiration (TNA). INTERVENTIONS: Forty-seven TNAs were performed in the emergency room (20) or during hospitalization (27). The TNA procedures were done without premedication and without fluoroscopic guidance. Specimens were processed using routine microbiologic and cytologic techniques; in addition, polymerase chain reaction (PCR) for Pneumocystis carinii was carried out since March 1992. Development of adverse effects was carefully evaluated. RESULTS: The TNA was effective in 29 (62 percent) out of 47 procedures. The diagnosis was obtained for 14 of 15 patients with P carinii pneumonia, 8 out of 14 patients with bacterial pneumonia, and 4 out of 12 patients with tuberculosis. Other pathogens recovered were Nocardia asteroides, Cryptococcus neoformans, Rhodococcus equi, and Mycobacterium avium. No false-positive results were obtained. Pneumothorax developed in eight (17 percent) procedures, but only one procedure resulted in a pleural drainage; the incidence of other adverse effects was low and clinically irrelevant. CONCLUSION: Our study suggests that TNA can be a useful technique in establishing the etiologic diagnosis of pulmonary infections in HIV-infected patients, with a good sensitivity, high specificity, and relatively low incidence of serious complications, with TNA appearing as a reliable alternative to more uncomfortable methods.

AIDS-Related Opportunistic Infections↗
PubMed1994

[Isolation of several species of the genus Aspergillus from soil of intrahospital ornamental plants].

The earth of ornamental plants is one of the main reservoirs of Aspergillus type of fungi in hospital areas. We studied 174 ornamental interior plants from a hospital at Santiago. Samples were obtained from the soil surface and sowed in Sabouraud-glucose agar, adding streptomycin and G-penicillin. After 72 h of culture, at least one strain of Aspergillus was isolated from 140 samples (80.5%). The most frequently isolated strain was A fumigatus (129 samples), followed by A niger (75 samples). A fumigatus and A niger were the only isolated strains in 65 and 11 samples respectively. These findings confirm that ornamental plants can be important reservoirs of Aspergillus strains, a potential infectious agent for immunocompromised patients, in hospital areas.

Aspergillus↗
PubMed1994

[Hemobilia caused by ruptured hepatic artery aneurysm].

We report two patients with hemobilia caused by hepatic artery aneurism that ruptured to the biliary tract. In the first patient, the diagnosis was made during an exploratory laparotomy. In the second patient, the aneurism was diagnosed with a selective hepatic artery arteriography and embolized during the procedure. The evolution of both patients was satisfactory.

Adolescent↗
PubMed1994

Frequency of sister chromatid exchanges in humans at 14-16 week foetal stage and at birth.

In order to identify transplacental induced mutagenicity in humans the baseline frequency of sister chromatid exchanges (SCEs) in amniotic fluid cells (8.56 +/- 0.28 per cell) from 14 to 16-week-old foetuses as well as in peripheral blood lymphocytes (7.96 +/- 0.26 per cell) from newborns was determined. A group of twelve patients who were analysed both at 14-16 weeks gestation and at birth showed no SCE variations. These results suggest that foetal amniocytes and T lymphocytes from newborns present a similar sensitivity to the mutagenic activity of the thymidine analogue 5-bromodeoxyuridine employed in the sister chromatid differentiation.

Adult↗
PubMed1993

Dendrites of rod dominant ON-bipolar cells are coupled by gap junctions in carp retina.

Gap junctions are supposed to be the anatomical substrate for electrical coupling between neurons. In fish retina, bipolar cells are electrically coupled and their receptive field diameters are always larger than dendritic field size, however, gap junctions have not been described between dendrites of bipolar cells. In this paper, using immunostaining for protein kinase C, we show that every rod dominant ON-bipolar cell is connected with its neighboring dendrites by gap junctions forming a plexus in the outer plexiform layer. These dendritic processes provide the site of electrical coupling. We suggest that dendrites of bipolar cells could be involved in lateral pathways in retina.

Animals↗
PubMed1993

Decrease in thyrocalcitonin-containing cells and analysis of other congenital anomalies in 11 patients with DiGeorge anomaly.

Experimental studies have demonstrated that the DiGeorge anomaly is due to cranial neural crest abnormalities. In the present study, the quantitation of thyrocalcitonin immunoreactive cells (C-cells) has been used to evaluate whether cells derived from the cranial neural crest are or are not present in normal proportions in patients with this anomaly. Thyroid sections from 11 such patients and 11 control patients were studied immunohistochemically at autopsy in order to determine the number and distribution of thyrocalcitonin-containing cells. Patients with DiGeorge anomaly showed thymic and parathyroid aplasia/hypoplasia and cardiovascular defects, such as type B interrupted aortic arch, truncus arteriosus and tetralogy of Fallot. Other associated defects were alobar holoprosencephaly and meningocele (previously unreported defects in this anomaly), arhinencephaly, renal cystic dysplasia, ureterohydronephrosis, esophageal atresia with tracheoesophageal fistula, and cleft lip and palate. The volume density of C-cells (1.187%) and the mean number of C-cells per follicle (1.42) was significantly lower in patients with DiGeorge anomaly than in control patients (3.475% and 2.367, respectively). These results indicate a decrease in cells derived from the neural crest in patients with DiGeorge anomaly, and support the hypothesis of a neural crest disturbance as the pathogenetic factor responsible for this anomaly.

Calcitonin↗