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Biomedical subjects

F Diaz

Publications and source records attributed to F Diaz.

108 records · Page 6Linked to original sources
PubMed1982

New formulas for the calculation of effective renal plasma flow.

Estimation of effective renal plasma flow (ERPF) can be made easily, inexpensively, and accurately by means of a single plasma concentration determination, sampled 44 min after injection of 131I-orthoiodohippurate (OIH). We originally established predictive regression equations based on a series of patients with a wide variety of diseases and a few normal potential kidney donors. The equation best fitting that data was parabolic in form and assumed a negative slope when high ERPF rates were encountered. This problem has been corrected by deriving new equations (parabolic and exponential) based on an expanded series which includes a large number of subjects with high ERPF. Errors of estimation are lower than those of the more classic para-aminohippuric acid (PAH) clearances and well within the exigencies of clinical practice.

Adolescent↗
PubMed1978

Mucoceles with intracranial and extracranial extensions. Report of two cases.

Two cases of unusual childhood mucocele are presented. These serve to illustrate the great potential these lesions have for slow, insidious development and insinuation of themselves into regions of the head and face where they are difficult to remove surgically. A description of the staged surgical excision is presented to emphasize the importance of radical removal of these benign lesions.

Adolescent↗
PubMed1976

Upper gastrointestinal bleeding in cirrhosis: clinical and endoscopic correlations.

The clinical data of 180 episodes of upper gastrointestinal bleeding in 168 patients with cirrhosis of the liver are examined. The source of bleeding had been determined by early endoscopy in all cases. In men under the age of 50 years, and without symptoms of liver failure, bleeding was due to ruptured gastro-oesophageal varices in 84% of cases. Severe liver failure was associated with acute lesions of gastric mucosa in many cases. No presumptive diagnosis of the source of haemorrhage could be based on the examination of other clinical data (presence of ascites, mode of presentation and pattern of bleeding, history of ulcer disease, alcoholism, and previous medication.

Adult↗
PubMedDate not supplied

Germ cell DNA quantification shortly after IR laser radiation.

The immediate effect of IR laser radiation on rat germ cells was studied by cytophotometric quantification of the nuclear DNA content in testicular sections. Two different levels of radiation were studied: one according to clinical application (28.05 J/cm2) and another known to increase the germ cell number (46.80 J/cm2). The laser beam induced changes in the germ cell DNA content depending on the cell type, the cell cycle phase and the doses of radiation energy applied. Following irradiation at both doses the percentage of spermatogonia showing a 4c DNA content was increased, while the percentage of these with a 2c DNA content was decreased. Likewise, the percentages of primary spermatocytes with a DNA content equal to 4c (at 28.05 J/cm2), between 2c and 4c (at 46.80 J/cm2) and higher than 4c (at both doses) were increased. No change in the mean spermatid DNA content was observed. Nevertheless, at 46.80 J/cm2 the percentages of elongated spermatids with a c or 2c DNA content differed from the controls. Data show that, even at laser radiation doses used in therapy, the germ cell DNA content is increased shortly after IR laser radiation.

Animals↗
PubMedDate not supplied

Acquired epileptic aphasia (the Landau-Kleffner syndrome) due to neurocysticercosis.

A healthy 7-year-old boy developed a language disorder associated with clinical seizures and a paroxysmal EEG. Computed tomography and magnetic resonance imaging revealed a small cysticercus deep in the left Sylvian fissure. We postulate a cause and effect relationship between the parasitic cyst and the clinical manifestations supported by the strategic location of the cyst and the critical age at which this lesion developed. This case provides evidence that the syndrome of acquired epileptic aphasia may be explained in terms of an unilateral structural brain lesion.

Aphasia↗
PubMedDate not supplied

Usefulness of PSA density and PSA excess in the differential diagnosis between prostate cancer and benign prostatic hypertrophy.

The usefulness of PSA density (PSAD) was evaluated in relation to the volume of the transitional zone (PSAT) and PSA excess. With this purpose we conducted a study including 27 patients diagnosed as having prostatic cancer (PC) and 46 patients with benign prostatic hypertrophy (BPH). In all of them, the PSA concentration in the serum was determined as well as the total prostatic volume and the transitional zone volume; digital rectal examination (DRE) was also performed. The major diagnostic efficacy was obtained with the excess of PSA (73%, cutoff = -13 ng/ml), followed by DRE (68%), PSAT (64%, cutoff = 0.5), PSAD (64%, cutoff = 0.2), and lastly PSA and ultrasonography (60%). Multivariate analysis (logistic regression) demonstrated PSA excess and DRE to be the best predictors. The model obtained by regression shows the best positive predictive value, and PSA excess the best negative predictive value. Consequently, PSA excess could be relevant in prostate cancer diagnosis.

Confidence Intervals↗
PubMedDate not supplied

The role of breast milk in protecting urban Peruvian children against cryptosporidiosis.

To test the hypothesis that breast milk of nursing mothers may afford children protection against cryptosporidiosis, a prospective cohort study was carried out in the young peoples' community of San Juan de Miraflores near Lima, Peru. Mothers and newborn children were sorted into cohort groups based on the mothers' breast milk antibody response to Cryptosporidium sporozoites using an antibody-capture enzyme-linked immunosorbent assay to detect parasite-specific immunoglobulin A. Children were monitored for Cryptosporidium infection using an indirect immunofluorescence assay. Of 211 mothers enrolled in the study, 39 (18.5%) had high breast milk antibody titers, 107 (50.7%) had medium titers, and 65 (30.8%) had low titers. Sixty-one episodes of Cryptosporidium infection were detected in 50 children of these mothers. Eleven (22%) had mothers in the high antibody titer group, 20 (40%) had mothers in the medium titer group, and 19 (38%) had mothers in the low titer group. The prevalence of infection within children of each group was 0.17, 0.19 and 0.38 respectively. There was no significant difference in the prevalence or duration of infection among children of the different groups. The data does not support the notion that there is protection from Cryptosporidium infection afforded children whose mothers have demonstrable breast milk antibodies against the parasite.

Adult↗
PubMedDate not supplied

Normalization of the altered liver function tests after islet transplantation in diabetic rats.

The purpose of our study was to determine if streptozotocin induced diabetes (SID) in rats produces alterations in hepatic function, as described in poorly controlled diabetic patients, and if islet transplantation (islet-Tx) would subsequently ameliorate this status. Hepatocellular dysfunction was evaluated by the aspartate aminotransferase (SGOT) and the alanine aminotransferase (SGPT) activities in plasma. For the evaluation of cholestasis the plasma alkaline phosphatase (APase) activity was used. These determinations were performed in normal, SID, SID with Islet-Tx, and SID Wistar rats with sham-Tx. Also, glucose was measured in plasma samples, as well as histological studies of the liver were performed. More than 1,000 isogeneic islets (islet-Tx group) or non viable insular tissue (sham-Tx group) were transplanted via mesenteric ileal vein three weeks after SID. The results showed that SID in rats produces alterations in the hepatic function as well as in the structure of the hepatocytes, and the normalization of carbohydrate metabolism by islet transplantation restores normal hepatic function and morphology.

Alanine Transaminase↗