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Biomedical subjects

A Lopez

Publications and source records attributed to A Lopez.

At least 253 records · Page 14Linked to original sources
PubMed1987

Biochemical and cytologic alterations in the respiratory tract of rats exposed for 4 hours to hydrogen sulfide.

Fischer-344 rats were killed by exsanguination 1, 20, and 44 hr after a single 4-hr exposure to an atmosphere of 0, 10, 200, and 400 ppm of hydrogen sulfide (H2S). Alterations in the activities of lactate dehydrogenase and alkaline phosphatase, and cytomorphology of epithelial cells in fluids obtained by nasal and bronchoalveolar lavage were used as indicators of cell injury. Changes in the number of leukocytes were used as indicators of inflammatory response, and changes in the concentration of protein were used as indicators of altered vascular permeability. Inhalation of H2S resulted in 139, 483, and 817% increased cellularity in the nasal cavity of rats exposed to 10, 200, and 400 ppm, respectively. This was due to marked exfoliation of degenerated epithelial cells and exudation of neutrophils. The high dose of H2S resulted in a moderate increase in lactate dehydrogenase and protein in nasal passages; values returned to baseline levels 20 hr later. Bronchoalveolar cell counts were decreased in rats exposed to 400 ppm and unchanged in those exposed to 10 and 200 ppm. Enzymatic activities in lung lavage fluid were moderately elevated (up to 90%), yet protein concentrations were increased by more than 3000% and remained significantly elevated up to 44 hr after exposure to 400 ppm. It was concluded that inhalation of H2S has a severe cytotoxic effect on the nasal epithelium and a severe edematogenic effect on lung parenchyma. These results are in agreement with autopsy findings of individuals killed by accidental exposure to H2S-containing sour gas.

Alkaline Phosphatase↗
PubMed1987

[Sonographic diagnosis of holoacardius].

In the 28th week of gestation a normal foetus and a holoacardius were diagnosed via sonography in a biamnotic monochoriatic twin pregnancy. The growth of the foetuses was observed under continuous sonographic control up to the 40th week of pregnancy. The patient delivered a healthy twin by Caesarean section and the acardius was subjected to a postmortem. Macroscopic and histological findings in the foetus, the placenta and the umbilical cords are demonstrated. The pathogenesis of the holoacardius is discussed as being due to chromosomal aberrations and foeto-foetal transfusion syndrome.

Abnormalities, Multiple↗
PubMed1987

Phacomatosis pigmentovascularis: a new syndrome? Report of four cases.

We examined four patients who had a combination of extensive nevus flammeus, significant oculocutaneous pigmentation, and severe neurologic alterations. All cases were sporadic. The vascular and neurologic alterations were clinically similar to those observed in the Sturge-Weber syndrome. The capillary vessels are ultrastructurally different in phacomatosis pigmentovascularis from those of a nevus flammeus in the Sturge-Weber syndrome; however, melanocytes of normal aspect were present in the middle and deep dermis. The characteristic oculocutaneous pigmentation probably represented a noncoincidental association. The term phacomatosis pigmentovascularis seems appropriate for this apparently new neurocutaneous syndrome.

Brain Diseases↗
PubMed1987

Effect of vehicular volume on the early pulmonary injury and inflammatory response in rats inoculated intratracheally with silica.

The effect of vehicular saline solution volume on early lesions induced in rats by intratracheal administration of silica was evaluated. Seventy-two male Long-Evans rats were randomly assigned 6 each to 12 factorial groups (3 X 2 X 2): 3 doses of silica (0, 2.5, and 5 mg), 2 volumes of vehicle (saline solution; 0.1 and 0.5 ml), and 2 postinoculation times (1 and 3 days). Lactate dehydrogenase and alkaline phosphatase activities in the bronchoalveolar lavage fluid supernatant and cell viability of bronchoalveolar cells were used as indicators of cell injury. The number of pulmonary alveolar macrophages and polymorphonuclear leukocytes were used as indicators of inflammatory response. Dose of silica and postinoculation time had a significant (P less than 0.05) effect on the biochemical and cellular composition of lavage fluid. The volume of vehicle in which silica was suspended significantly (P less than 0.05) enhanced the pulmonary injury and inflammatory response. However, dose-volume interaction was only significant (P less than 0.05) in 1 of 6 parameters, indicating that the effect was additive, but not synergistic, in nature. Seemingly, vehicle volume had an enhanced effect on the injury and the inflammatory response induced by intratracheal inoculation of silica.

Animals↗
PubMed1987

Effect of intratracheal inoculation of Pasteurella haemolytica cytotoxin on the integrity of rat lung.

This study was conducted to investigate the in vivo effect of a single intratracheal inoculation of Pasteurella haemolytica cytotoxin on the rat lung. Changes in the biochemical and cytological composition of bronchoalveolar lavage fluid were used to estimate the magnitude of pulmonary cell injury, inflammatory response, vascular permeability and functional status of pulmonary alveolar macrophages. Effect of treatment was compared with rats intratracheally inoculated with supernatants of Pasteurella multocida or with sterile physiological saline solution (vehicle). Results indicated that Pasteurella haemolytica supernatants were not significantly toxic for the lungs of rats.

Animals↗
PubMed1987

Profiles of type-II pneumocytes in rats inoculated intratracheally with bacterial lipopolysaccharide.

Ultrastructural and morphometric profiles of type-II pneumocytes (P-II) were investigated in rats killed 18 or 24 hours after a single intratracheal inoculation of bacterial (Escherichia coli) lipopolysaccharide (LPS). Inoculation with LPS induced pulmonary injury and inflammation, as measured by increased lactate dehydrogenase and alkaline phosphatase activities and increased numbers of polymorphonuclear neutrophils in fluid collected by bronchoalveolar lavage. Marked ultrastructural changes and desquamation of a few P-II developed at the time of high activity of lactate dehydrogenase and alkaline phosphatase in bronchoalveolar lavage fluid. Ultrastructural changes included swollen mitochondria and localized cisternal dilatation of the endoplasmic reticulum in which was contained membrane-bound homogenous material of medium electron density. Twenty-four hours after LPS inoculation, point-count stereologic analysis and digitizing morphometry revealed greater than 50% increase in P-II size. Changes in cell size corresponded with ultrastructural finding of swollen cells. Results obtained by point-count stereologic analysis and digitizing morphometry were highly correlated (r = 0.95). Lamellar bodies (LB) comprised 12 to 15% of P-II volume. Volume density and number of LB remained unaltered in LPS-injured P-II, and evidence of accelerated release of LB was not detected after LPS inoculation. Exudated polymorphonuclear neutrophils and pulmonary alveolar macrophages were involved actively in the phagocytosis of LB originating from necrotic and desquamated P-II. On the basis of measurement of enzyme activity (enzymes released into the bronchoalveolar space), considerable ultrastructural alterations developed in P-II when maximal LPS-induced pulmonary cell injury took place.

Animals↗
PubMed1986

Survival after intestinal mucormycosis in acute myelogenous leukemia.

A young woman with acute myelocytic leukemia developed acute lower gastrointestinal bleeding immediately after a first remission induction of her leukemia. After the site of bleeding was located in the descending colon, a necrotic bleeding ulcer was resected. Histologic examination of the ulcer established the diagnosis of gastrointestinal mucormycosis. Treatment with amphotericin B was administered because of the high risk of dissemination. The patient has been followed for 9 months with no evidence of relapse of infection. Survival after gastrointestinal mucormycosis in acute leukemia has not previously been reported in the English language literature. Success in managing mucormycosis depends on the adherence to the recommended principles of early aggressive diagnostic measures, excisional surgery, amphotericin B therapy, and control of the underlying predisposing condition.

Adult↗
PubMed1986

Response of liver and kidney adenylate kinase to fasting and refeeding in three strains of mice.

The effects of fasting and refeeding on the AK isozymes in liver and kidney were studied in three strains of mice. Our studies showed that changes in total AK activity and AK isozyme patterns were associated with fasting and refeeding. The AK isozyme changes were strain-dependent, differing in kind and degree among the three strains. It was concluded that species, strain and individual isozyme identities should be included in studies defining changes of enzyme activity owing to changes in physiological conditions.

Adenylate Kinase↗
PubMed1986

Oestradiol and testosterone binding sites in mice tibiae and their relationship with bone growth.

High affinity oestradiol and testosterone binding sites were found in tibiae cytosol from entire male and female of different ages. Scatchard assay allowed to estimate a Kd of 2.7 X 10(-9) M for oestradiol binding sites indicating that the 3H-oestradiol binding was of high affinity. Oestradiol and testosterone binding sites abundance in mice tibiae are subject to change with age. It is not easy to establish a direct correlation between these changes and the values reported here on bone growth in weight and length, however seems possible to point a negative relationship between bone lengthening and oestradiol binding site levels in female, as well a positive relationship with testosterone in both sexes. The presence of oestradiol and testosterone binding sites in epiphyses and not in the diaphyses reinforces the hypothesis that both are playing some role in bone growth.

Age Factors↗
PubMed1986

Evidence for the importance of 5'-deoxy-5-fluorouridine catabolism in humans from 19F nuclear magnetic resonance spectrometry.

The use of a new methodology, 19F nuclear magnetic resonance, has allowed detection of all the fluorinated metabolites in the biofluids of patients treated with 5'-deoxy-5-fluorouridine (5'-dFUrd) injected i.v. at a dose of 10 g/m2 over 6 h. This technique, which requires no labeled drug, allows a direct study of the biological sample with no need for extraction or derivatization and a simultaneous identification and quantitation of all the different fluorinated metabolites. As well as the already known metabolites, unmetabolized 5'-dFUrd, 5-fluorouracil, and 5,6-dihydro-5-fluorouracil, the presence of alpha-fluoro-beta-ureidopropionic acid, alpha-fluoro-beta-alanine (FBAL), N-carboxy-alpha-fluoro-beta-alanine, and the fluoride anion F- is reported. The catabolic pathway proposed for 5'-dFUrd is analogous to that of 5-fluorouracil, completed with FBAL----F- step, and the plasmatic equilibrium of FBAL with N-carboxy-alpha-fluoro-beta-alanine, its N-carboxy derivative. The quantitative analysis of the different metabolites found in plasma and urine emphasizes the significance of the catabolic pathway. High concentrations of alpha-fluoro-beta ureidopropionic acid and FBAL are recovered in plasma from 3 h after the beginning of the perfusion to 1 h after its end. The global urinary excretion results show that there is a high excretion of 5'-dFUrd and metabolites. Unchanged 5'-dFUrd and FBAL are by far the major excretory products and are at nearly equal rates. The protocol followed in this study produces relatively low but persistent plasmatic concentrations of 5-fluorouracil throughout the perfusion.

Aged↗
PubMed1986

Magnetic resonance imaging of the opto-chiasmatic region. Report on 276 cases.

A total of 276 lesions in the sellar and parasellar region were studied with magnetic resonance imaging using two different magnets of 0.15 and 0.5 T, respectively. Examination in the sagittal plane is recommended. T1 weighted images will give anatomic details, T2 weighted images the tissue characteristics. No marked differences with regard to diagnostic results were noted with the two different magnets, although the signals appeared to be more intense when using a 0.5 T magnet.

Adult↗
PubMed1986

Cellular inflammatory response in the lungs of calves exposed to bovine viral diarrhea virus, Mycoplasma bovis, and Pasteurella haemolytica.

Three, 5, or 7 days after inoculation with bovine viral diarrhea (BVD) virus (n = 12) or Mycoplasma bovis (n = 12), groups of calves were exposed to aerosols of Pasteurella haemolytica and were euthanatized 4 hours later. Histologic lesions in the lungs and the ratios of neutrophils to alveolar macrophages, collected by bronchoalveolar lavage, were compared with those of clinically healthy calves (n = 8) and calves inoculated with BVD virus only (n = 4), M bovis only (n = 4), or P haemolytica only (n = 2). Inoculation with BVD virus or M bovis did not have a significant (P greater than 0.05) effect on the neutrophil/macrophage ratio in the bronchoalveolar lavage. Aerosol exposure to P haemolytica induced a marked and significant (P less than 0.01) change in the neutrophil/macrophage ratio (from less than 1:9 to greater than 9:1). The reversed neutrophil/macrophage ratio in calves exposed to P haemolytica correlated well with the histologic changes in which small bronchi and bronchioles were plugged with purulent exudate. Inoculation with BVD virus did not induce gross or microscopic lesions in the lungs. Inoculation with M bovis resulted in a severe peribronchial lymphoid hyperplasia with mild exudation of neutrophils and macrophages into the cranioventral parts of the lungs.

Animals↗
PubMed1986

Injury versus inflammatory response in the lungs of rats intratracheally inoculated with bacterial lipopolysaccharide.

The relationship between acute pulmonary cell injury and inflammatory response was investigated in rats killed 1, 3, and 7 days after intratracheal inoculation with bacterial lipopolysaccharide (LPS). Activities of lactate dehydrogenase (LDH) and alkaline phosphatase (AP) in bronchoalveolar lavage (BAL) fluid and bronchoalveolar cell (BAC) lysate supernatants were used as indicators of cell injury in the lung. Concentrations of protein in BAL fluid and the number and types of BAC were used as indicators of pulmonary inflammatory response. The magnitude of inflammation and cell injury was calculated as the percentage difference of cellular and biochemical values, compared with values of nontreated controls. Inoculation with LPS induced a significant and dramatic (greater than 18,000%) influx of polymorphonuclear leukocytes (PMN) and a mild (approx 250%) increase in pulmonary alveolar macrophages. A moderate, significant and time-dependent increase in LDH (up to approx 260%) and AP (up to approx 220%) was detected in BAL fluid and BAC lysate supernatants after LPS inoculations. Inoculation with saline solution alone resulted in increased PMN (approx 975%), but did not alter LDH and AP values. In all rats evaluated, protein concentrations did not change. Numbers of PMN significantly and positively correlated with activities of LDH and AP. Protein concentrations and PMN counts had a negative nonsignificant association. Evidence of further cell injury was not detected after massive influx of PMN into the bronchoalveolar space. Therefore, the cellular influx of PMN induced by LPS probably was disproportionate to the magnitude of pulmonary cell injury.

Alkaline Phosphatase↗