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Biomedical subjects

F Gil

Publications and source records attributed to F Gil.

105 records · Page 6Linked to original sources
PubMed1972

Kinetic and morphological observations on the yeast phase of Histoplasma capsulatum during protoplast formation.

Protoplast formation by Histoplasma capsulatum yeasts using high concentrations of MgSO(4) occurs either by lysis of the bud or lysis of the entire cell wall. Both mechanisms may also occur simultaneously. Neither the protoplast emerging through a hole in the cell wall nor the freshly released protoplast has a recognizable cell wall or the remnant of such. The protoplast contains all the organelles of the normal cell except for mesosomes. During protoplast formation the nucleus increases in size and produces several nuclear masses by the invaginations of the internal layer of the nuclear membrane. All these nuclear masses are surrounded by the external layer of the nuclear membrane. Several nuclei with a normal nuclear membrane are formed later.

Cell Division↗
PubMed1970

Chemical morphology of glucan and chitin in the cell wall of the yeast phase of Paracoccidioides brasiliensis.

Short and thick fibers were observed on the outer surface of the yeast phase of Paracoccidioides brasiliensis, and long and thin fibers were seen on the inner surface. The long fibers disappear with chitinase treatment and are composed of chitin. The short fibers disappear under alkali treatment and are composed of alpha-glucan. Comparisons with alpha-(1 --> 3)-glucan isolated from Aspergillus niger and Polyporus betulinus and with chitin from fungal origin support our point of view.

Aspergillus↗
PubMedDate not supplied

Biomarkers as biological indicators of xenobiotic exposure.

The presence of a xenobiotic in the environment always represents a risk for living organisms. However, to talk about impregnation there is a need to detect toxicity in the organism, and the concept of intoxication is related to specific organ alterations and clinical symptoms. Moreover, the relationship between the toxic levels within the organism and the toxic response is rather complex and has a difficult forecast because it depends on several factors, namely toxicokinetic and genetic factors. One of the methods to quantify the interaction with xenobiotics and its potential impact on living organisms, including the human being, is monitoring by the use of the so-called biomarkers. They can provide measures of the exposure, toxic effect and individual susceptibility to environmental chemical compounds and may be very useful to assess and control the risk of long-term outcomes associated with exposure to xenobiotic (i.e. heavy metals, halogenated hydrocarbons, pesticides).

Animals↗
PubMedDate not supplied

Prevalence of measles antibody among children under 15 years of age in Santa Cruz, Bolivia: implications for vaccination strategies.

We conducted a community-based survey in Santa Cruz city, Bolivia, to determine the age-specific prevalence of measles antibodies, determine factors associated with absence of detectable measles antibodies, and to compare results of salivary and serum measles immunoglobulin G (IgG) antibody assays. Serum samples from 1654 children were assayed for measles IgG antibody using the haemagglutination inhibition (HI) assay, and salivary samples were also obtained from 187 children and tested for measles IgG antibody using an antibody capture radioimmunoassay. Reported measles vaccine coverage in children aged 12-35 months was 77% (95% confidence interval [CI], 72-81%). Eighty-seven percent (95% CI 85-89%) had detectable HI antibody, but a high proportion had antibody levels below 200 miu (30-40% of 2-14 years old children). Measles seronegativity was associated with not being vaccinated against measles, a negative history of measles disease, living in the inner city, being a lifetime resident of Santa Cruz, and young age. Of 212 children without detectable measles antibody, 58% had a positive history of vaccination or measles disease, so that historical information was not sufficiently reliable to identify susceptibles. The salivary measles antibody assay was not sufficiently sensitive to be used for population screening; only 54% of 171 salivary samples from children who had detectable serum HI antibody were positive. A mass measles vaccination campaign of all children under 15 years of age is planned in Bolivia in 1994. Although only 7% of school-age children in Santa Cruz were seronegative, the effectiveness of a mass campaign in this age group depends in part on the response to revaccination of children with low, but detectable, antibody levels.

Adolescent↗
PubMedDate not supplied

Magnetic resonance imaging and cross sectional anatomy of the normal equine sinuses and nasal passages.

The purpose of this investigation was to define the magnetic resonance imaging anatomy of the rostral part of the equine head. 10 mm-thick, T1-weighted images of two isolated equine cadaver heads were obtained using a 1.5 Tesla magnet and a body coil. MR images were compared to corresponding frozen cross-sections of the cadaver head. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the oral and nasal cavities, paranasal sinuses and associated structures. Annotated MR images from this study are intended as a reference for clinical MR imaging studies of the equine head.

Animals↗
PubMedDate not supplied

Magnetic resonance imaging of the normal equine brain.

The purpose of this investigation was to define the magnetic resonance (MR) imaging appearance of the brain and associated structures of the equine head. MR images were acquired in oblique dorsal (T2-weighted), sagittal (T1-weighted), and transverse planes (T2-weighted), using a magnet of 1.5 Tesla and a human body coil. Relevant anatomic structures were identified and labeled at each level. The resulting images provided excellent anatomic detail of the cranioencephalic structures. Annotated MR images from this study are intended as a reference for clinical imaging studies of the equine head, specially in the diagnosis of brain diseases in the horse.

Animals↗
PubMedDate not supplied

Tegumental Ca-stimulated adenosine triphosphatase activity in adult Schistosoma mansoni worms.

A Ca-stimulated ATPase activity (pH 9.5) associated with the tegumental membrane enriched (TME) fraction of Schistosoma mansoni adults was partially inhibited by NAP-taurine or by increasing concentrations of chlorpromazine; endogenous calmodulin was found associated with the TME fraction. A similar activity (pH 8.6) was histochemically visualized within the tegument of fixed worms on the cytoplasmic leaflet of both the double surface membrane and the basement membrane; this reaction was inhibited by 1 microM chlorpromazine and it was also observed on the inner side of double membrane vesicles present in the TME fraction. No ATPase activity could be seen at alkaline pH with added Mg or Na/K ions. Without ATP, the addition of external Ca to the fixed worms induced the appearance of lead precipitates on the tegumental discoid bodies; this reaction was inhibited by molybdate and not by chlorpromazine. The intrategumentary regulation of calcium by the systems described and the possible use of phenothiazines against schistosomes are discussed.

Animals↗
PubMedDate not supplied

Diverticular disease and treatment with gastric acid inhibitors do not predispose to peritonitis of enteric origin in peritoneal dialysis patients.

OBJECTIVE: Enteric peritonitis (EP) is an infrequent complication of peritoneal dialysis (PD), with severe consequences for peritoneal membrane viability and patient outcome. Factors such as diverticular disease and gastric acid inhibitors have been implicated in its appearance. We investigated several risk factors, including those mentioned below, that can influence the development of EP. DESIGN: Retrospective cross-sectional study. SETTING: Tertiary-care public university hospital. PATIENTS: Fifty-seven PD patients treated in our PD unit during August 1998. MAIN OUTCOME MEASURES: A barium enema was performed on 50 of the 57 patients (the remaining 7 patients refused it) in order to exclude the presence of diverticulosis. All episodes of peritonitis occurring in those patients, including EP, were registered. Enteric peritonitis was defined as that caused by gram-positive, gram-negative, or fungus micro-organisms that colonized the intestinal tract, excluding episodes secondary to genitourinary tract or peritoneal catheter exit-site infections. RESULTS: Twenty-four patients showed diverticular disease in the barium enema, but only 5 of them (21%) had any EP episode. Five of the 26 patients with no diverticula (19%) had EP. Fifty-five episodes of peritonitis were reported in 21 patients; 15 episodes of EP (27.3% of all) developed in 11 patients. Seven of the 11 patients (64%) required peritoneal catheter removal and 3 of them (27%) finally were transferred to hemodialysis due to consequences of the EP episode. Logistic regression analysis did not find any of the independent variables analyzed (age, sex, time on PD, type of PD, peritoneal transport parameters, presence of polycystic kidney disease, constipation or diverticulosis, or treatment with gastric acid inhibitors, or phosphate-binding agents) to be risk factors for developing EP. CONCLUSIONS: Neither diverticulosis nor treatment with gastric acid inhibitors seem to be risk factors for developing peritonitis of enteric origin in PD patients. This type of peritonitis has to be promptly identified and treated in order to diminish the high frequency of peritoneal catheter removal and PD dropout due to such episodes.

Adolescent↗
PubMedDate not supplied

[Idiopathic membranous nephropathy in an elderly patient with type 2 diabetes mellitus].

We report an 85 years-old patient with type 2 diabetes mellitus and both clinical and biochemical nephrotic syndrome. The renal biopsy showed membranous nephropathy at stage I-II. There was no evidence of malignancy. The patient was treated with steroids, and two months later the proteinuria had not improved. The objects under discussion are the factors that should lead to suspect the existence of glomerulonephritis, other than diabetic glomerulosclerosis, suggesting the need for kidney biopsy. We also focus on the prognostic and therapeutic relevance, as well as on the common pathogenic aspects.

Adrenal Cortex Hormones↗