Search PubMed⌕ Search

Biomedical subjects

C Ferreira

Publications and source records attributed to C Ferreira.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Organophosphate poisoning and myocardial necrosis].

A man (46 years-old) was admitted to the intensive care unit (ICU) with a history that eight hours before he had voluntarily drank 100 ml of malathion. He complained of a burning pain on the anterior thorax and was confused. His cardiovascular evaluation was normal and his breathing was heavy with some rales on the pulmonary auscultation. He was treated with atropine and contrathion and rapidly evolved into coma. Electrocardiogram showed subendocardial lesion in the inferior wall with diffuse ly altered ventricular repolarization and increase QT interval. During the ICU period his cardiac enzyme levels also raised. The patient died in the 8th day after admission. The pathological evaluation of the heart revealed foci of myocardial necrosis. This is the 1st case of medical literature with histological confirmation of myocardial necrosis from organophosphate intoxication.

Humans↗
PubMed1996

Contribution of plasma membrane and endoplasmic reticulum Ca(2+)-ATPases to the synaptosomal [Ca2+]i increase during oxidative stress.

In the present study we analyzed the effect of ascorbate (0.8 mM)/Fe2+ (2.5 microM)-induced membrane lipid peroxidation on the levels of intracellular free calcium,[Ca2+]i and on the possible mechanisms involved in the perturbation of intracellular calcium homeostasis during oxidative stress. For this purpose, the influence of the ascorbate/iron oxidant system on the plasma membrane and endoplasmic reticulum Ca(2+)-dependent ATPases of brain cortical synaptosomes was studied. In addition, the influence of the peroxidative process on the uptake of calcium (45Ca2+) and on the Na+/Ca2+ exchange activity at the plasma membrane was evaluated. After ascorbate/Fe(2+)-induced membrane lipid peroxidation of the order of 18.05 +/- 4.20 nmol TBARS/mg protein, an increase in [Ca2+]i occurred, under basal or depolarizing conditions (30 mM KCl), which was dependent on the extracellular calcium concentration. Thus, for 1 and 3 mM extracellular calcium concentration, an increase of the resting [Ca2+]i values of 19.8% and 33.7% was observed, while after the K(+)-depolarization the enhancement of the [Ca2+]i was 18.4% and 29.5%, respectively. The Na+/Ca2+ exchange activity and the time-dependent influx of 45Ca2+ observed in basal conditions and after the 30 mM K(+)-depolarization, were not affected under the peroxidative conditions. The Ca(2+)-dependent ATPase activity of the synaptosomal plasma membrane was significantly depressed following peroxidation of membrane lipids, decreasing the V(max) by 48.1%, without significant changes in the affinity of the enzyme for calcium (K(m) for Ca2+ was 0.54 +/- 0.04 microM in control conditions and 0.56 +/- 0.034 microM in peroxidized conditions). The Ca(2+)-ATPase activity of the endoplasmic reticulum was also affected during ascorbate/iron-induced oxidative stress; thus, an inhibition of 45.2% was observed 5 min after adding ATP. These data suggest that the increase in synaptosomal [Ca2+]i due to oxidative stress may result from the inhibition of the plasma membrane and the endoplasmic reticulum membrane Ca(2+)-ATPase activities, probably as a result of the alteration of the lipid environment required for the maximal activity of these membrane enzymes. The consequent increase in [Ca2+]i may be responsible for the injury of the nervous tissue observed during several pathological conditions in which free radical generation seems to be involved.

Adenosine Triphosphatases↗
PubMed1996

Expression of ubiquitin, actin, and actin-like genes in African swine fever virus infected cells.

Northern blot hybridisation was used to study the accumulation of specific cellular mRNAs (ubiquitin and actin) in Vero cells infected with African swine fever virus (ASFV). ASFV modulates the cytoplasmic levels of ubiquitin and actin mRNAs throughout infection. Before viral DNA replication, degradation of ubiquitin mRNAs is dependent on de novo protein synthesis, since treatment with cycloheximide (CH) allowed the accumulation of ubiquitin mRNAs, while treatment with cytosine arabinoside (araC) induced a reduction in ubiquitin transcripts. Nevertheless, viral DNA replication is essential to the final increase observed in ubiquitin mRNA degradation. Furthermore, ubiquitin transcription seems to be tightly related to viral gene transcription, since before viral DNA replication ubiquitin and viral transcripts accumulate at opposite rates. Concerning actin transcription, the first step in actin mRNA degradation does not depend on de novo protein synthesis, since treatment with CH induced a reduction in actin mRNA. The second step in actin mRNA degradation, similarly to ubiquitin, depends on viral DNA replication. Finally, in the present study it has also been shown that ASFV codifies for actin-like genes. This is the first report of a virus encoding an actin-like gene.

Actins↗
PubMed1996

An immunocytochemical investigation of trypsin secretion in the midgut of the stablefly, Stomoxys calcitrans.

Musca domestica trypsin antibody cross-reacts with polypeptide bands of M(r) 25,000 and 30,000 showing proteolytic activity from Stomoxys calcitrans midgut extracts. Secretory granules from the main enzyme-secreting region, the opaque zone, stained heavily with the trypsin antibody in both unfed and blood-fed flies. Heterogeneous staining of granules suggests the unequal distribution of trypsin in secretory granules. This is also consistent with the occurrence of non-parallel secretion, which is also suggested by the possible preferential release of smaller, heavily stained secretory granules in fed flies. The predigestive, anterior midgut region responsible for rapid dehydration of the blood meal, the reservoir zone, contains a different population of secretory granules which stain heavily with trypsin antibody. This zone contains 20% of the midgut trypsin activity in unfed flies; trypsins are held here as proenzymes which are probably only activated postsecretion. In the midgut lumen of both unfed and blood-fed flies, trypsin is mainly immunolocalized in the ectoperitrophic space. Enzyme assays suggest that 5-15% of the lumenal trypsin is associated with the peritrophic matrix. The finding of intact secretory granules plus cell debris in the ectoperitrophic space of opaque and lipoid zones of blood-fed flies supports the contention that some trypsin is released by apocrine secretion in this insect.

Animals↗
PubMed1996

[PSA levels and its relationship with digital examination, age, and score of prostatic symptoms].

Between November 1992 and March 1993 our Service conducted a campaign for early detection of prostate disease among the male population of Vigo. The study focused in the relationship of PSA with the age, rectal examination and prostate symptomatology score. In view of the results obtained it has been concluded that PSA levels increase gradually as a function of age, volume and prostate symptomatology score.

Age Distribution↗
PubMed1996

[Cushing syndrome caused by macronodular hyperplasia ACTH-independent].

Case report of a 49-year old male patient who presented with signs and symptoms in agreement with Cushing's Syndrome, the etiology of which was shown to be an ACTH-independent macronodular hyperplasia. In such cases, the therapeutical choice is bilateral adrenalectomy which was adopted by us using a posterior approach. The relevance of the clinical diagnosis and therapeutical aspects of this condition are reviewed.

Adrenal Glands↗
PubMed1996

[Effect of verapamil on left ventricular hypertrophy induced by isoproterenol].

PURPOSE: We evaluated whether verapamil (VERA) has a protective effect on left ventricular hypertrophy (LVH) induced by Isoproterenol (ISO) in rat. METHODS: Seventy two male adult rats were divided in four groups and treated accordingly during eight days: Control (CON), VERA (10 mg/kg), ISO (0.3 mg/kg) and VERA + ISO. It was measured in 10 animals from each group heart rate, blood pressure, left ventricle dry weight and ratio between left ventricular weight (LVW) and rat weight. Samples were taken from the left ventricle to be examined by light microscopy. RESULTS: LVW of the CON group was 0.145 g, of VERA was 0.144 g, of ISO with 0.201 g, and of VERA + ISO was 0.148 g. The difference between ISO group and others was statistically significant (P < 0.05). The LVW/W ratio also showed similar result. The myocardial pattern induced by ISO was left hypertrophy and collagen content increase. In VERA + ISO group it was found a protective effect to hypertrophy (ISO group 97% vs VERA + ISO 87%; p < 0.001) and increased collagen content. CONCLUSION: VERA prevents the deleterious effects of ISO in the myocardium. Probably this action is due to prevention the myocardial hypertrophy and proliferation of collagen tissue.

Animals↗
PubMed1996

[Effect of enalaprilat on cardiotoxicity induced by doxorubicin].

PURPOSE: To evaluate whether the enalaprilat, an angiotensin converting enzyme inhibitor, was able to prevent the myocardial damage induced by doxorubicin (DOX). METHODS: Four groups composed of 10 Wistar rats each were followed for seven weeks: control (CONT); treated with enalaprilat (ENA, 1mg/kg/d/sc) treated with doxorubicin (DOX, 25 mg/kg/d/sc), and treated with doxorubicin plus enalaprilat (DOX+ENA). In eight animals of each group, the left ventricle (LV) was prepared for morphometric study and stained with HE and picro-sírius for identifying muscle fibers and collagen. In each group three fragments of the LV were examined with electronic microscopy (EM). For statistical analysis: the one-way analysis of variance was performed and was followed by multiple comparisons test when the difference between groups were detected p values < or = 0.05 were considered significant. RESULTS: Light microscopy-it was not found any significant difference among the groups for muscle fibers patterns and proportion of collagen fibers of left ventricle. Electronic microscopy-the cristolysis index (proportion between normal and damage mitochondria) demonstrated significant difference between DOX and DOX+ENA groups (30.1 vs 11.6, p < or = 0.01). CONCLUSION: ENA prevented cardiotoxic alterations induced by DOX minimizing the aggression to the mitochondria and these findings, if confirmed in anima nobilis, may open a new clinical use for this type of drug.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

[Enzyme-induced masculinization].

Contribution of two cases of congenital adrenal hyperplasia by blockade in the 21-hydroxylase enzyme synthesis. Diagnosis was reached from the clinical signs and symptoms (virilization syndrome), and was confirmed by radiological and laboratory tests. Hormone treatment was done with hydrocortisone and fludrocortisone, but surgical correction of external genitalia was required to improve cosmetic appearance.

Adolescent↗
PubMed1994

[Conn's syndrome].

Adrenal hypertension is an uncommon phenomenon. When seen in association with hypokalemia the existence of primary aldosteronism, the most frequent cause of which is an adenoma of the adrenal gland cortex, should be suspected. This paper contributes one case of primary aldosteronism treated by unilateral resection of the adrenal adenoma, with no surgical complications and good medium-term results.

Humans↗
PubMed1993

Prolonged pH monitoring is of limited usefulness for gastroesophageal reflux.

OBJECTIVE: To assess the diagnostic value of pH monitoring. DESIGN: A prospective study. SETTING: Pediatric university hospital serving as a secondary and tertiary referral center. PARTICIPANTS: Thirty-eight infants, aged 1 to 12 months, and 26 children, aged 13 months to 18 years, admitted during a 2-year period because of clinically significant gastroesophageal reflux (GER). INTERVENTIONS: Prolonged (20-hour) pH monitoring as well as endoscopy and biopsy of the esophagus were carried out in all patients who, on the basis of clinical data, were classified as having mild, moderate, or severe GER disease. RESULTS: In the infant group, results of prolonged pH monitoring were abnormal in 34 (89.5%). In the older group, results were abnormal in less than half (11 [42.3%]) of the cases. In both groups, pH monitoring data did not correlate with the severity of GER disease or of esophagitis. Severity of GER disease was not predictive of esophagitis. CONCLUSIONS: (1) Endoscopy and biopsy of the esophagus should be the first procedures whenever there are clinical findings of moderate to severe GER disease. (2) Monitoring of pH should be restricted to those patients without a clear-cut history of GER disease.

Adolescent↗
PubMed1992

[Enalapril and myocardial protection from stress by cold].

PURPOSE: To evaluate the myocardial protective effect of enalaprilat in rats submitted to stress by cold. METHODS: Fifteen adults, male rats were studied. They were allocated into four groups: group A received unrestricted diet + intraperitoneal (IP) diluent; group B: unrestricted diet + IP enalaprilat 1.0 mg/kg; group C: high salt diet (HD) for seven days + IP indomethacin 1.0 mg/kg and group D received high salt diet for seven days + IP indomethacin 1.0 mg/kg + IP enalaprilat 1.0 mg/kg. Three animals were the control group. The animals of the groups A, B, C and D were then submitted to stress by cold. Fragments of the left ventricle were obtained for electron microscopy and the occurrence of mitochondrial lysis or preservation of the mitochondrial ultrastructure were considered as parameter for myocardial protective effect evaluation. RESULTS: Crystolysis (partial or total) was observed in 16.2% group A; 19.5% of group C; 3.2% of group B and in 8.8% of group D. CONCLUSION: Enalaprilat protects the cardiomyocyte from the stress by cold.

Animals↗
PubMed1992

[A cardiac lesion secondary to paraquat].

PURPOSE: To evaluate cardiac alterations secondary to exogenous intoxication by paraquat. METHODS: We performed analysis of clinical and laboratory data of 25 patients with acute paraquat poisoning admitted in our ICU from November 1983 to January 1991. RESULTS: There were purposeful overdoses in 24 cases (96%). The mortality rate was 56%. The lung involvement was 96%, renal was 92%, gastrointestinal tract was 72%, hepatic was 56%, and cardiac involvement was 40%. CONCLUSION: Cardiac involvement due to paraquat is frequent (40%). The clinical picture of this involvement has a wide spectrum, ranging from minimal changes in the ECG to acute and extensive myocardial necrosis.

Adolescent↗
PubMed1992

[Electrocardiographic changes in accidental hypothermia].

PURPOSE: Electrocardiographic alterations were evaluated in a group of accidental hypothermia patients, and correlated with values of core temperature, pH and plasmatic concentrations of Na+, K+ and Cl-. METHODS: Conventional 12-lead surface electrocardiograms were obtained in a group of 32 patients with accidental hypothermia after involuntary cold exposure. Cardiac arrhythmias, QRS configuration, ST-T segment and T wave alterations were analyzed. pH, Na+, K+ and Cl- serum concentrations were simultaneously measured. Electrocardiogram and electrolyte abnormalities were then correlated with the core temperature. RESULTS: Twenty-eight patients had abnormal electrocardiogram (90.6%). Sinus bradycardia and idioventricular rhythm were observed in 11 and 3 patients respectively. QT interval enlargement was found in 24 patients and Osborn wave in 28 cases. Altered T waves expressing an abnormal repolarization were observed in 23 cases. A significant negative correlation was obtained when J wave amplitude was correlated with core temperature levels. CONCLUSION: Hypothermia produces electrocardiographic abnormalities characterized by Osborn waves. Other minor findings include sinus bradycardia, idioventricular rhythm and long QT intervals.

Arrhythmias, Cardiac↗