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Biomedical subjects

R Campos

Publications and source records attributed to R Campos.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Severe digestive hemorrhage of an unusual etiology. Visible isolated and bleeding esophageal vessels].

We describe two patients with massive upper gastrointestinal bleeding. The upper gastrointestinal endoscopy revealed jet haemorrhage in the distal portion of the esophagus, from a visible vessel, without esophageal mucosal damage. In both cases arteriography was performed, and did not show vascular malformations or fistulous points. The patients were successfully treated, one with endoscopic sclerosis and balloon tamponade, and the other with endoscopic sclerosis and transcatheter embolization through left gastric artery. For the time being we do not know the true importance of these findings, but we hope that other reports help us to understand the clinical and pathologic features of this vascular lesion, and the best therapeutic approach.

Adolescent↗
PubMed1991

Nutritional quality of lupine (Lupinus albus cv. Multolupa) as affected by lactic acid fermentation.

The effects of selected NRRL strains of Lactobacillus acidophilus, L. buchneri, L. cellobiosus and L. fermentum upon oligosaccharide, phytate and alkaloid contents, as well as on the nutritive value of lupine, were investigated. Lupine was processed to a 12% total solids suspension, inoculated with 1% (v/v) cultures and fermented until a final desired pH of 4.5. L. acidophilus B-2092 and L. buchneri B-1837 growth was related to a significant sucrose breakdown and decreases of phytates, whereas L. acidophilus B-1910 and L. fermentum B-585 reduced the content of flatulence oligosaccharides. The activity of L. acidophilus B-1910 was particularly associated with lowering of alkaloids and increase of riboflavin. Lactic acid fermentation produced slight changes in lysine and methionine contents. No significant differences in net protein ratio values and protein digestibility were found between fermented and unfermented lupine (P less than 0.05). A 1:1 ratio mixture of B-1910 and B-2092 strains of L. acidophilus lead to a final fermented lupine with nutritional advantages to those given by the individual cultures.

Alkaloids↗
PubMed1991

A field evaluation of anthelmintics for control of cyathostomes of horses in Brazil.

The anthelmintic efficacy of ivermectin (IVM), piperazine citrate (PPZ) and fenbendazole (FBZ) alone, and combinations of FBZ with varying dosages of PPZ, was evaluated for the control of strongyles of Mangalarga equids. In all cases of positive strongly egg counts per gram of faeces (EPG) before and after treatment, pure populations of cyathostome larvae with eight gut cells were consistently observed in faecal cultures. The faecal egg count reductions (FECR) were evaluated between Day 7 and Day 56 post-treatment. Significant differences (P less than or equal to 0.05) were found between Day 7 and Day 49 when comparing the mean EPG values of IVM with those of the other anthelmintics. PPZ alone and the combination of FBZ (7.5 mg kg-1) and PPZ (55 mg base kg-1) did not show significant differences during the trial; both groups exhibiting an FECR of greater than 90% between Day 7 and Day 30. Horses treated with the combinations of FBZ (7.5 mg kg-1) and PPZ at either 40 or 25 mg base kg-1, and with FBZ alone at either 7.5 or 15 mg kg-1, showed an FECR of less than 90% 2 weeks after treatment. The emergence of a degree of resistance of strongyles to FBZ and PPZ in a segment of the cyathostomes in this population is suggested.

Animals↗
PubMed1991

Acetaminophen does not induce oxidative stress in isolated rat hepatocytes: its probable antioxidant effect is potentiated by the flavonoid silybin.

Acetaminophen hepatotoxicity is characterized by glutathione depletion and the formation of the reactive electrophilic metabolite N-acetyl-p-benzoquinone imine. The induction of oxidative stress, expressed as lipid peroxidation, is controversial in acute acetaminophen intoxication. Isolated rat hepatocytes develop spontaneously or when incubated with buthionine sulfoximide, a progressive lipid peroxidation which may be inhibited by the antioxidant flavonoid silybin. When cells are incubated with acetaminophen, lipid peroxidation is not observed, this antilipoperoxidative effect being potentiated by silybin. It is proposed that when hepatocytes are incubated with a high concentration of acetaminophen, the drug may accumulate in the cells due to saturation and/or inhibition of detoxification pathways (as in the case of silybin). Under these conditions the development of hepatocyte oxidative stress may be inhibited due to the antioxidant behaviour of acetaminophen.

Acetaminophen↗
PubMed1991

The rat glucagon gene is regulated by a protein kinase A-dependent pathway in pancreatic islet cells.

A cAMP response element (CRE) has been identified in the proximal 5'-flanking region of the rat glucagon gene, and activation of the cAMP-dependent pathway in fetal rat intestinal cells leads to an increase in the levels of glucagon mRNA transcripts. In contrast, the human glucagon gene does not contain a similar CRE, and the results of studies using immortalized rat and hamster islet cell lines have suggested that glucagon gene expression may not be regulated by cAMP. To reconcile these observations, we have studied the control of glucagon gene expression. Incubation of primary rat islet cell cultures with forskolin in the presence of low (0.5 g/liter) or high (2.0 g/L) glucose resulted in a 2- to 3-fold increase in the levels of glucagon mRNA transcripts. Forskolin also stimulated the secretion and synthesis of immunoreactive glucagon. The importance of the protein kinase-A-dependent pathway in the regulation of glucagon gene expression was also examined in hamster islet InR1-G9 cells. Cotransfection of a glucagon-chloramphenicol acetyltransferase (CAT) fusion gene containing the glucagon CRE and a cDNA encoding the catalytic subunit of protein kinase-A resulted in stimulation of glucagon-CAT activity in hamster islet cells. Catalytic subunit cotransfection also activated somatostatin-CAT, but no activation of RSVCAT was detected. The results of these experiments suggest that the rat glucagon gene is regulated by a protein kinase-A-dependent pathway in the endocrine pancreas.

Animals↗
PubMed1991

Atherosclerosis in diabetes and hypertension. A comparative morphometric study of their progression using an atherometric system.

The three major epicardial coronary arteries of a set of 472 autopsy cases divided into four groups: a) non-diabetics and non-hypertensive, 322 subjects; b) hypertensive, 75 subjects; c) diabetics, 57 subjects and d) hypertensive and diabetic, 17 subjects, were studied. Classical pathomorphological procedures and an atherometric system (AS), suitable to characterize the atherosclerotic lesions, was used searching for differences between the level of atherosclerosis into these four groups and its eventual progression according to the time of evolution of these diseases. Raw data processing was full automated and some univariate and multivariate statistical procedures (means, standard deviations, ANOVA, MANOVA and principal components analysis) were performed using two commercial statistical packages: "NCSS" and "SYSTAT". The most remarkable findings were the following: Diabetes and hypertension have both strong impact upon the rate at which the atherosclerotic process takes place in subjects affected by these diseases. The time of evolution of both diseases correlates positively and independently of age with the velocity of the atherosclerotic process at the three coronary arteries. The impact of diabetes seems to be stronger and is particularly expressed by the severe plaques (Z) while the effect of hypertension is specially observable at the fibrous plaques (Y). There seems to be no significant interaction (synergism) between the two risk factors upon the measurement of the atherosclerotic lesions, that is, they have an additive effect. Two simple underlying factors can be used to account for interindividual differences. These two factors are "dominated", respectively, by fibrous (Y) and severe plaques (Z).

Analysis of Variance↗
PubMed1991

Atherosclerotic lesion of the circle of Willis: its study applying an atherometric system using multivariate statistical techniques.

In 2043 autopsies divided into the high (HAG) and low (LAG) atherosclerosis group a set of variables of a new atherometric system (AS) was used to characterize the atherosclerotic lesion (AL) in the circle of Willis arteries: fatty streaks (X), fibrous plaques (Y), severe plaques (Z), index of stenosis (P) and index of benignity (B). Principal component analysis identified a first component of severity (Y, P and Z) and a second component of benignity (X and B). Fibrous plaques play the main role in the severity of AL in the circle of Willis. The new AS proved its usefulness in characterizing the state of AL, whereas discriminant analysis and AS distinguished between the HAG and the LAG. The classification was correct in 74.5% and 76.5% when using three (X, Y, Z) and five (X, Y, Z, P, B) variables, respectively.

Arteriosclerosis↗
PubMed1991

[Ludwig's angina, its evolution and treatment].

An anaerobic neck infection located in the submandibular layer is described in this paper. We report a case of satisfactory evolution and make a bibliographic review of this problem. All the AA. agree that the key to successful management of such infections is early diagnosis, prompt surgery and associated antibiotic therapy.

Adult↗
PubMed1990

Increased resistance against oxidative stress is observed during a short period of renal reperfusion after a temporal ischaemia.

Reperfusion of rat kidney submitted to temporal ischaemia induces a decrease in glutathione content. Lipid peroxidation is not detected in kidney homogenates but microsomes obtained after periods of reperfusion longer than 60 minutes show increased malondialdehyde values correlated with high oxygen consumption and superoxide free radical generation. Microsomes obtained from kidneys submitted to 15 or 60 minutes of reperfusion are resistant to NADPH-induced lipid peroxidation but after 120 minutes of reperfusion an increased lipid peroxidative response is observed. Although the mechanism of the protection found in microsomes against the induction of oxidative stress in the first 60 minutes of reperfusion is unknown, it is postulated that this subcellular fraction plays an important role in the oxidative stress observed after longer periods of reperfusion.

Animals↗
PubMed1990

Histopathological sinus node classification and its relation to coronary atherosclerosis using an atherometric system.

Studies were conducted into 100 consecutive subjects (autopsy material), 53 men and 43 women between 31 and 70 years old, who had died a natural death. The HUDSON-procedure was used for histopathological analysis of the cardiac conducting system (CCS). About 48 microscopic slides of each subject, including sinus node (SN) tissue, were inspected by 4 pathologists in a blind study. The findings were classified by 3 different groups according to histopathological data of the SN, viz. changes and distribution of P and T cells, stroma, artery, and innervation of SN. The 3 major epicardial branches of coronary arteries were prepared for morphometric studies by WHO standards. A digitizer coupled to a microcomputer LTEL (Cuba, IBM-compatible) was used for quantitative evaluation of atherosclerotic lesions (AL), and all data were subsequently processed on the same computer, using a statistical commercial package (Number Cruncher Statistical System) for results. An atherometric system was used and proved to be a properly standardized methodology, suitable to characterize AL in any vascular sector or group of patients. The most remarkable results were as follows: Three-group classification was useful in estimating the association between pathomorphological data of SN and coronary atherosclerosis. The atherometric system proved to be a powerful tool to study and characterize atherosclerotic lesions in coronary arteries.

Adult↗
PubMed1989

Modification of foot-and-mouth disease virus after serial passages in the presence of antiviral polyclonal sera.

Foot-and-mouth disease virus (FMDV) shows a remarkable antigenic variability. Like other RNA viruses, this virus has a high rate of mutation. It has been proposed that selection exerted by the host's antibodies could play a major role in the rapid evolution of FMDV. The present work reports the selection of FMDV antibody-resistant populations (Nr), after serial passages of cloned FMDV A24 Cruzeiro strain on secondary monolayers of bovine fetal kidney cells in the presence of subneutralizing antiviral polyclonal sera (APS). After a limited number of passages under selective pressure, the virus population showed the following characteristics: (1) increased resistance to neutralization by APS; (2) altered electrophoretic mobility of structural viral proteins (VP1); (3) remarkable plaque size reduction, (4) a pronounced thermosensitivity (ts); and (5) decreased pathogenicity for mice, in both uncloned and cloned small plaque size populations. This indicates that FMDV populations under antibody pressure in vitro, have acquired, in addition to expected characteristics of natural FMDV variants (resistance to neutralization and altered viral structural proteins), phenotypic markers which correspond to attenuated, less virulent variants.

Antibodies, Viral↗
PubMed1989

Silybin dihemisuccinate protects against glutathione depletion and lipid peroxidation induced by acetaminophen on rat liver.

Acetaminophen hepatotoxicity is characterized by glutathione depletion, cellular necrosis, and, in some instances, by the induction of lipid peroxidation. Silybin dihemisuccinate, a soluble form of the flavonoid silymarin, protects rats against liver glutathione depletion and lipid peroxidation induced by acute acetaminophen intoxication. Other biochemical parameters such as serum transaminases did not show the drastic increase observed under acetaminophen intoxication when animals were treated with the flavonoid. Preliminary results suggest that silybin dihemisuccinate may be another antidote against acetaminophen hepatotoxicity.

Acetaminophen↗
PubMed1989

Coronary atherosclerosis in sudden death: a comparative study applying an atherometric system.

Coronary arteries affected by atherosclerosis and its myocardial related damage in cardiac and non-cardiac sudden death subjects (152 and 98, respectively) including a low atherosclerosis group (250 subjects) were studied in autopsy material applying a new well standardized atherometric system. A high statistical significance of all variables of this system was found between the groups studied.

Adult↗
PubMed1988

Increased histidine decarboxylase (HDC) activity in human colorectal cancer: results of a study on ten patients.

Following numerous reports of high histidine decarboxylase (HDC) activity in tumour-bearing animals, the present work was designed to determine the activity of this enzyme in normal and tumour tissues in a series of ten surgical patients with colorectal carcinoma. Significantly increased HDC activity, almost double that of normal tissues, was found in specimens from extirpated human tumours. These results, obtained under reliable sampling and measurement conditions indicated that changes in the enzymic activity of HDC may have a significant role in the development of colorectal tumour cells. Inhibition of the enzyme activity in human cancer subjects may retard or impede tumour growth and perhaps limit the spread of metastases.

Adult↗
PubMed1988

Coronary atherosclerotic lesion: its characterization applying an atherometric system, using discriminant analysis.

A given set of autopsies (total 2043) divided into high and low atherosclerosis groups (HAG, LAG) according to the primary cause of death 1171 and 872 cases, respectively, was studied by an atherometric system. The variables of this system characterize the pathomorphological changes, i.e. fatty streaks (X), fibrous plaques (Y) and severe (complicated and calcified) plaques (Z) of atherosclerosis. In the present study were also included two indices, stenosis (P) and benignity (B), applicable for estimation of the severity of the process. In order to verify the discrimination between the HAG and LAG groups the utility of the classification should be demonstrated. The three main branches of the coronary arteries, right (RC), left anterior descending (LAD) and left circumflex (LC), were examined. Qualitative and quantitative analyses of the different vascular changes were made by means of a digitizer coupled to a personal computer NEC 9801 (Japan). The data were processed in a computer EC-1040 (GDR). The multivariate statistical techniques, including discriminant analysis were used applying the "SPSS" commercial statistical package programme. The atherometric system proved to be useful to distinguish between HAG and LAG. Correct classification was in all cases greater than 70% except for LC (68%). The three variables X, Y and Z were capable to separate the groups. The stenosis and benignity indices proved to be the most effective for discrimination. The sign of benignity index discriminating function is always the same of the LAG. This variable is indeed one to indicate benignity. The coherence and consistency of the atherometric system developed was proved by discriminant analysis.

Coronary Artery Disease↗