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Biomedical subjects

A Castillo

Publications and source records attributed to A Castillo.

At least 91 records · Page 5Linked to original sources
PubMed1993

Clinical and metabolic factors associated with the blood retinal barrier permeability in insulin dependent diabetes mellitus without retinopathy.

The authors assessed a study pointing out the relationship between the permeability of Blood Retinal Barrier (BRB), using vitreous fluorophotometry, and several risk clinical and laboratory data in Insulin Dependent Diabetes Mellitus (IDDM). Eighty eyes of 40 IDDM patients were evaluated. Their mean age was 14.8 +/- 3.2 years. Twenty healthy volunteers served as control group (mean age 15.3 +/- 3.2 years). Preexisting diabetic retinopathy was dismissed after funduscopy and fluorescein angiography. The studied risk factors were: age, duration of diabetes, HLA antigens, blood pressure, cholesterol and triglycerides levels, glycosylated hemoglobin, insulin dose/kg body weight and fructosamine. Vitreous and lens fluorophotometry was performed in both groups (VPRt). The mean VPRt in IDDM patients was 3.56 +/- 1.47 x 10(-6) min-1. In healthy subjects it was 2.53 +/- 0.55 x 10(-6) min-1, establishing a significant difference (p < 0.01). We found a statistically significant correlation between VPRt and duration of diabetes, insulin dose/kg body weight and HbAlc. No correlation was found between VPRt and the rest of parameters. We conclude that vitreous fluorophotometry is a valid method to measure BRB; and the three factors mentioned above are related to the BRB permeability.

Adolescent↗
PubMed1993

An 18-month vitreous fluorophotometric follow-up study in juvenile diabetics.

The authors assessed a fluorophotometry follow-up study of 18 months in 24 juvenile insulin-dependent diabetic patients with no retinopathy. The initial duration of diabetes was 5.96 +/- 3.44 years and the glycosylated hemoglobin (HbA1c) was 10.12 +/- 2.27%. The baseline Vitreous Penetration Ratio transmittance value (VPRt) was 4.13 +/- 1.31 x 10-6 min-1 and after 18 months was 5.36 +/- 1.85 x 10-6 min-1, yielding a statistically significant difference (p < 0.01). The average HbA1c during the follow-up term was 9.80 +/- 1.72%. VPRt values were significantly correlated with the duration of diabetes and HbA1c. During the follow-up 3 patients developed foveal background diabetic retinopathy with respect to a high initial VPRt value (6.22 +/- 0.27 x 10-6 min-1), nevertheless, the other 7 patients with high baseline VPRt did not do so. We suggest that vitreous fluorophotometry could be a beneficial procedure in the management of insulin-dependent diabetic patients; however, there is not a cut-off value for VPRt values to help distinguish patients prone to develop retinopathy.

Adolescent↗
PubMed1993

[The use of ELISA and indirect immunofluorescence technics for the rapid detection of eastern equine encephalomyelitis].

We present the results attained in the identification of Eastern equine encephalomyelitis virus isolations in Vero and XL-2 cell systems, using a double-antibody ELISA technique and the indirect immunofluorescence method. The results attained through these two techniques coincided by 100% with identification through neutralization. With the former, the virus was detected within 6-8 hours after inoculation. Better results were attained with XL-2 cells.

Animals↗
PubMed1993

[Rapidly progressive glomerulonephritis without immune deposits: detection of neutrophil anticytoplasmic antibodies].

Antineutrophil cytoplasmic autoantibodies (ANCA), are serologic markers of disease in rapidly progressive glomerulonephritis without immune deposits (pauci-immune) and vasculitis, and could play a pathogenic role in these diseases. We communicate 5 patients with pauci-immune rapidly progressive glomerulonephritis; four of them in the evolution of necrotizing systemic vasculitis (Wegener's granulomatosis and microscopic polyarteritis) and one case with lesions limited to the kidney. All of them were associated with the presence of ANCA. The immunofluorescence pattern (cytoplasmic and perinuclear) and the antigenic specificity of ELISA assay, [antiproteinase-3 (PR-3) and antimyeloperoxidase (MOP)], are useful laboratory tools for the diagnosis and clinical management of these patients.

Aged↗
PubMed1993

Phenotypic characterization of oral streptococci by classical methods.

The phenotypic characteristics of 215 strains of oral streptococci were compared on the basis of the results of sorbitol, raffinose and trehalose fermentation, ammonium from arginine production, aesculin hydrolysis, H2O2 production, susceptibility to 2 U bacitracin, and growth in 4% NaCl solution. Eleven different species were identified. Among the most noteworthy findings were the low number of H2O2-producing strains of Streptococcus sobrinus, the effective discrimination between Streptococcus sanguis and Streptococcus mitis on the basis of raffinose fermentation, and the phenotypic similarity between Streptococcus oralis and the former mutans group. To avoid the creation of new species, the term biotype is proposed to designate phenotypically distinct organisms which do not qualify as different species.

Dental Plaque↗
PubMed1992

In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride.

We investigated the influence of sodium fluoride on polymorphonuclear leukocyte (PMN) adhesiveness in a healthy subject with low serum levels of fluoride. The PMN were separated from venous blood, and the percentages of adhered and unadhered cells were determined in vitro in plastic culture plates. The cells were cultured with five different fluoride concentrations ranging from 6.25 10(-2) microM to 4.0 microM in the presence and absence of autologous serum. PMN adhesiveness in both the presence and in the absence of autologous serum was 98.5%; the addition of fluoride had no effect on the results in the absence of serum. However, in the presence of autologous serum, PMN adhesiveness decreased significantly with the addition of fluoride (P < 0.05) from 0.5 microM. The decrease was smaller (1.1%) at a concentration of 0.125 microM, and larger at 12 times this concentration of fluoride (52.7%). We conclude that sodium fluoride reduces PMN adhesiveness in a dose-dependent manner. The effect is not direct, but should be modulated by a seric factor.

Adult↗
PubMed1992

[Acute epiglottitis in adults].

The author presents the clinical history of 14 patients, from 21 to 48 years of age, 10 men and 4 women, with a final diagnosis of acute epiglottitis who were hospitalized at Gorgas Army Hospital or at the San Fernando Clinic. All the patients had pharyngitis and dysphagia, a few with nasal voice, stridor and difficulty breathing, as the chief complaint. All the patients were initially intubated orally for diagnostic purposes and immediately after nasotracheal intubation was done until the patient improved in 2 or 3 days (one patient remained intubated for 5 days). All patients were kept in the Intensive Care Unit and were treated with Ampicillin and Chloramphenicol IV and lately with a second generation cephalosporin (Cefamandole). The patients allergic to Penicillin were treated with Clindamycin and Chloramphenicol. Corticosteroids were not used in any of the patients. There were no sequelae and none of the patients expired.

Acute Disease↗
PubMed1991

Post-hatching development of the thymic epithelial cells in the rainbow trout Salmo gairdneri: an ultrastructural study.

This study reports the ultrastructure of subpopulations of epithelial cells of the thymic parenchyma during the post-hatching development of the rainbow trout, Salmo gairdner, kept at 14 degrees C. At hatching, the thymus contained a small number of medium and large thymocytes interspersed among three different types of epithelial cells: (1) epithelial cells adjacent to the connective tissue capsule; (2) ramified dark epithelial cells with electron-dense cytoplasm; and (3) pale electron-lucent epithelial cells displaying secretory-like features. All these cells types were anchored to one another by desmosomes and had apparently differentiated from the pharyngeal epithelium. At 4 days after hatching, the thymus enlarged, and numerous gaps occurred between the cell processes of contiguous epithelial cells adjacent to the capsular connective tissue. In 21-day-old trout, thymic trabeculae developed carrying blood vessels, and a subcapsular zone became evident containing lymphoblasts and large subcapsular epithelial cells. In 30-day-old trout, an outer thymic zone developed consisting of spindle-shaped epithelial cells which formed a dense network. At this stage, scattered cystic cells, which apparently differentiated from the pale epithelial cells, were present.

Animals↗
PubMed1991

Antimicrobial susceptibility of 1042 strains of Streptococcus mutans and Streptococcus sobrinus: comparison from 1985 to 1989.

A total of 1042 strains of Streptococcus mutans and Streptococcus sobrinus isolated between 1985 and 1989 were tested to study the evolution of their sensitivity to penicillin, amoxycillin, amoxycillin/clavulanic acid, cefuroxime, tetracycline, erythromycin, spiramycin, acetyl spiramycin, lincomycin and clindamycin. The strains were taken from stock cultures and isolated from human saliva and dental plaque. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Except for spiramycin and acetyl spiramycin, all the antibiotics inhibited 100% of the strains with concentrations less than or equal to 2 micrograms/ml. Microorganisms from both species underwent a slow progressive loss of sensitivity to all the antibiotics over a 5-year period of study, showing statistically significant results in most cases.

Dental Plaque↗
PubMed1991

Oral ecology and its pathogenic relation with the origin of primary periodontitis associated with plaque.

Microbial factors involved in the genesis of periodontitis are related with supragingival (coronal) and subgingival plaque. The microorganisms in the supragingival plaque reach the gingival sulcus, and are influenced by ecological determinants in this zone which condition the establishment of adherent plaque. This plaque may subsequently form the substrate for particularly periodon to pathogenic bacteria, which may then form plaques adhered to the epithelium, or develop as floating (nonadhered) populations. After microbial colonization of the gingival sulcus, bacteria or substances they produce may reach the junctional epithelium and alveolar bone, leading to direct tissular destruction to an extent determined by the host's immune response. Damage may be local or generalized, depending on additional factors.

Dental Plaque↗
PubMed1991

[Bacteremic meningoencephalitis due to Listeria monocytogenes in an immunocompetent adult].

A 34 year old non pregnant, immunocompetent female developed severe meningoencephalitis. Bacteriologic studies established listeria monocytogenes as the causative organisms. This agent, previously limited to affect immunocompromised hosts, has recently been shown to be transmitted by the oral route to immunocompetent persons. This is the first report of such case in Chile.

Adult↗
PubMed1991

[Pulmonary endometriosis. Clinical case].

Pulmonary endometriosis is a rare entity and there is little information regarding its treatment. We report a young female who developed hemoptysis in coincidence with menstruation. Pelvic endometriosis was confirmed histologically and pulmonary endometriosis was inferred. Treatment with Danazol led to suppression of both menstruation and hemoptysis, thus confirming the clinical diagnosis.

Adult↗
PubMed1990

Mutagenicity of N-nitrosomorpholine biosynthesized from morpholine in the presence of nitrate and its inhibition by ascorbic acid.

N-nitrosomorpholine biosynthesis and inhibition in mice treated with nitrate, morpholine and ascorbic acid, was studied by means of the mutagenic activity in urine samples. The preincubation method was used and Salmonella typhimurium TA 1535 was the test strain. The results suggest that N-nitrosomorpholine biosynthesis was carried out when the animals were fed high doses of nitrate, however ascorbic acid was an inhibitor of this process.

Animals↗
PubMed1990

Effect of the ingestion of an extract from Bauhinia monandra seeds on rats.

Bauhinia monandra is a leguminous plant that would be used in human nutrition, however it shows a high hemagglutinating activity against trypsin-treated erythrocytes of rabbit, 2 ml of a NaCl-solution extract of the seeds was given to a group of rats for 10 days. Intestinal disaccharidase activity was determined. Histopathological and histochemical examinations were also performed. Lectins from Bauhinia monandra seeds did not cause any visible intestinal damage even when they seem to be able to bind to the enterocyte brush border. The low disaccharidase activity in the membrane and enterocyte fractions, which represent the enzyme synthesis level, indicates that lectins could reduce the synthesis of these enzymes rather than inhibit the active sites of the enzymes. This effect could be in turn related with the binding action of lectins, because no effect of the autoclaved extract on the disaccharidase activity was observed.

Animals↗
PubMed1990

Enzyme- and immuno-histochemical study of the thymic stroma in the rainbow trout, Salmo gairdneri, Richardson.

Owing to the lack of data about thymic non-lymphoid cells in fish we decided to perform a histochemical characterization of these cells in order to ascertain their relationships to other thymic components. In the present study we analyze the enzyme-histochemical patterns for acid phosphatase, alkaline phosphatase, non-specific sigma-naphthyl acetate esterase and 5' nucleotidase activities, as well as the presence of keratin demonstrated by immunoperoxidase staining, in the non-lymphoid cell populations of the thymus of the rainbow trout, Salmo gairdneri. According to their location in the organ, morphology and histochemical reactivities, we were able to define seven different subpopulations of keratin-positive epithelial cells: 1) Epithelial cells limiting with the capsular and septal connective tissues; 2) Subcapsular epithelial cells; 3) Stellate epithelial cells of the inner thymic zone; 4) Large, ovoid epithelial cells of the inner thymic zone; 5) Acidophilic epithelial cells of the outer thymic zone; 6) Cystic cells; and 7) Goblet cells. The significance of the heterogeneity of the epithelial cell (EC) population, its specific distribution in the organ, which apparently conforms distinct cell microenvironments, as well as the possible phylogenetical relationships between these microenvironments and the classical cortex and medulla of the mammalian thymus, are discussed.

5'-Nucleotidase↗
PubMed1990

[Polymyalgia rheumatica as a form of presentation of systemic lupus erythematosus].

Three cases of systemic lupus erythematosus (SLE) with clinical presentation similar to a rheumatic polymyalgia (RP) are described. There was no evidence of underlying myopathy in any of the cases thus suggesting that the synovitis is the pathogenic mechanism. The late onset and the poor serologic expression are the relevant clinical signs which could delay or hinder the diagnosis.

Aged↗