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Biomedical subjects

A Torres

Publications and source records attributed to A Torres.

At least 631 records · Page 35Linked to original sources
PubMed1986

Anaphylatoxin C5a generation and dialysis-induced leukopenia with different hemodialyzer membranes.

Leukocyte counts and plasma C5a anaphylatoxin levels were studied during hemodialysis in patients using Cuprophan, polycarbonate and polyacrylonitrile membrane dialyzers. Cuprophan induced a marked leukopenia with significant plasma C5a generation. Polycarbonate promoted the same trend of changes in both parameters but significantly less pronounced, while polyacrylonitrile did not affect leukocyte counts nor plasma C5a levels. These data suggest that complement-derived C5a generation may be an important factor in the mechanism of hemodialysis-induced leukopenia.

Acrylic Resins↗
PubMed1986

Comparison of histomorphometry and computerized tomography of the spine in quantitating trabecular bone in renal osteodystrophy.

Computerized tomography (CT) has the advantage of allowing the isolation of trabecular bone of the axial skeleton, which is the more sensitive to metabolic changes. By means of single-energy X-ray CT we have devised a method for assessing trabecular bone mass (TBM) at L-4 vertebral body, which has an acceptable reproducibility (CV = 2.76%). Normal values where obtained after studying 29 normal individuals from both sexes and different ages. In order to know if the method is accurate, TBM was assessed in 17 patients (6 with creatinine clearance less than 6 ml/min and 11 on chronic hemodialysis), and in all of them the results were compared with the histomorphometry of the iliac crest bone biopsy. TBM assessed by CT correlated with trabecular bone volume (TBV; mineralized bone + osteoid) (r = 0.82; p less than 0.001) and this correlation was not improved after adding the volume of marrow fibrosis to TBV. TBM assessed by CT also correlated with mineralized bone volume but at a lower level of significance (r = 0.72; p = 0.001), and no correlation was found with relative osteoid volume alone. These findings suggest that final CT value is an integral of mineralized bone and osteoid but with a higher influence of mineralized bone. Osteomalacia and osteitis fibrosa were seen in situations of normal, decreased, or increased TBM assessed by CT, although the 2 patients with severe osteosclerosis suffered osteomalacia. We conclude that the assessment of TBM by CT at the axial skeleton of uremic patients has an acceptable reproducibility and accuracy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Idiopathic peritesticular fibrosis associated with retroperitoneal fibrosis.

A 32-year-old male who presented with idiopathic retroperitoneal fibrosis developed peritesticular fibrosis 4 years later. The lesion appeared as a diffuse, uniform thickening without a tendency to form nodules. Histologic examination revealed a densely collagenized tissue with scattered cells, consisting mainly of fibroblasts and plasma cells. Small blood and lymphatic vessels of the tumor showed luminal dilation and perivascular edema with inflammatory infiltrates. No other associated pathology was found in the patient. We suggest that peritesticular fibrosis in this patient may be due to lymphatic drainage obstruction caused by retroperitoneal fibrosis.

Adult↗
PubMed1986

Sputum examination for the diagnosis of Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome.

The diagnostic utility of sputum examination in patients with Pneumocystis carinii pneumonia secondary to the acquired immunodeficiency syndrome (AIDS) has so far not been determined. Sputum was induced in 43 patients with AIDS or suspected AIDS just prior to fiberoptic bronchoscopy, scheduled because of an unexplained pulmonary infiltrate on a chest radiograph. Pneumocystis carinii pneumonia was diagnosed by sputum examination and/or by a bronchoscopic procedure in 20 patients. Of these, sputum samples were positive for Pneumocystis organisms in 11 (55%) of 20 patients tested, bronchial washings were positive in 11 (79%) of 14 patients tested, brush biopsies were positive in 9 (53%) of 17 patients tested, and transbronchial lung biopsies were positive in 18 (90%) of 20 patients tested. The presence of P. carinii cysts in sputum did not correlate with the presence of alveolar macrophages in sputum nor with the volume of sputum. Sputum examination for P. carinii organisms, employed as a first diagnostic step in patients with AIDS with pulmonary infiltrates, may frequently obviate the need for bronchoscopy.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Identification of a bovine enteric syncytial virus as a nongroup A rotavirus.

An atypical or nongroup A rotavirus was identified in feces obtained from gnotobiotic calves in which fecal preparations originally derived during an epizootic of neonatal calf diarrhea had been serially passaged. The epizootic was previously reported to be caused by a noncharacterized viral agent that induced the formation of epithelial syncytia on small intestinal villi of experimentally infected calves. This bovine, nongroup A rotavirus was found to be antigenically related to a described atypical rotavirus of rats by immunofluorescence and by enzyme immunoassay. Complementary DNA derived from the atypical rat rotavirus cross hybridized with RNA obtained from the bovine virus, but not with RNA extracted from group A rotaviruses. Complementary DNA derived from SA-11 group A rotavirus cross hybridized with other group A rotavirus RNA, but not with RNA obtained from either the rat or bovine nongroup A isolates. Additionally, another similar, if not identical, bovine atypical rotavirus was identified in a second epizootic of neonatal calf diarrhea that occurred several hundred kilometers and 8 months apart from the original epizootic.

Animals↗
PubMed1986

[Determination of the distribution of ventilation-perfusion ratios: technic of elimination of multiple inert gases].

The multiple inert gas elimination technique (MIGT) facilitates the estimation of the distributions of ventilation-perfusion (VA/Q) ratios in the experimental and clinical setting. The most relevant technical aspects and equipment and operational requirements needed to measure a mixture of inert gases in both the gas phase and the blood phase using gas chromatography are overviewed with detail. Results obtained in 3 dogs and 4 syringe-homogeneous lung models were entirely consistent with data formerly reported in the literature. Particular attention is paid to the linearity of the gas chromatograph detectors, reproducibility of inert gases sampling, and analysis of brands of heparin to detect acetone content. The errors of measurement (coefficients of variation) in blood were: 1.4 for sulfur hexafluoride; 1.8% for ethane; 2% for cyclopropane and halothane, each; 2.4% for diethyl ether; and, 3.6% for acetone. Important practical points are also emphasized in order to draw attention to potential problems and issues that should be concentrated upon to minimize the error in the measurements. It is concluded that the setting up of the MIGT is well established and validated.

Animals↗
PubMed1985

Effect of prazosin and yohimbine on systolic blood pressure and on renal norepinephrine content in DOCA-salt rats.

We studied the effect of alpha-1 and alpha-2 blockers (prazosin and yohimbine) on systolic blood pressure (SBP) and on renal norepinephrine (NE) content in Sprague-Dawley normotensive and DOCA-salt rats. The administration of desoxycorticosterone acetate (DOCA) to these rats for 6 weeks increased their SBP from 137 to 183 mmHg (p less than .001). This increase was prevented by simultaneous administration of prazosin (p less than .001), yohimbine (p less than .01), or prazosin + yohimbine (p less than .001). DOCA rats on saline and on yohimbine had lower renal NE content (p less than .05 and p less than .001, respectively) than normotensive rats. Renal NE content of DOCA rats on yohimbine decreased with respect to those treated with prazosin (p less than .001) or prazosin + yohimbine (p less than .05). Besides, renal NE content of DOCA rats on prazosin increased when compared to control DOCA rats (p less than .05). However, these drugs showed no effect on SBP and on renal NE content in normotensive rats. These findings further confirm that the alpha adrenoceptor blockade can prevent the hypertension of DOCA-salt rats in such a way that their blood pressure stabilizes at similar levels to those observed in normotensive treated animals.

Animals↗
PubMed1985

[Advances in possibilities for protein evaluation].

With protein evaluation the changing abilities of food proteins are characterized with regard to their covering the requirements of the organism for protein or amino acids, respectively. The biological value of proteins is influenced by several factors. Measuring the reaction of the whole organism (of man or animal) to the food protein the sum of all influencing factors is covered. Hence, these direct evaluation methods have priority. The general dose-reaction curve demonstrates the direct evaluation methods: The evaluation criteria protein efficiency or minimum protein requirement are presented and the different possibilities of interpretion are compared. Most direct evaluation methods are performed with suboptimal protein supply, therefore values for an optimum protein supply can be derived only with reservation. Improved values for protein evaluation can be obtained from investigations of the protein metabolism. With that the substrat-related evaluation can be more orientated to a organism-related one. Indirect biochemical evaluation methods are less important. That does not concern in-vitro evaluation by amino-acid analysis and/or in-vitro digestibility tests. Possibilities and limits of these methods are discussed.

Amino Acids↗
PubMed1985

No influence of number of donor CFU-GM on granulocyte recovery in bone marrow transplantation for acute leukemia.

The possible interrelation between infused bone marrow CFU-GM and peripheral granulocyte recovery was studied in 16 patients transplanted for acute leukemia. The influence of several clinical events that could modify the graft fate were also analysed. Our results show that: 1) There was no correlation between the number of infused nucleated cells and granulocyte recovery. 2) There was no correlation between the number of infused CFU-GM and granulocyte regeneration. 3) There were significant differences between the day of engraftment in patients with clinically documented HSV infection compared to patients without infection.

Acute Disease↗