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Biomedical subjects

E Carvalho

Publications and source records attributed to E Carvalho.

At least 55 records · Page 3Linked to original sources

[Effect of intravenous administration of SO4Mg in the acute phase of myocardial infarct].

Fifty four patients (p) with acute myocardial infarction (40M; 14F) were entered into a prospective study where they received either intravenous magnesium sulphate (group A-27 p) or placebo (group B-27 p). The incidence of arrhythmias necessitating treatment was greater in group B (37%) than in group A (15%). Mortality was 18.5% in group B and 3.7% in group A. These results suggest that magnesium sulphate administration reduces the incidence of arrhythmias and death after acute myocardial infarction.

Aged↗

[Therapeutic effectiveness of intravenous magnesium sulfate in tachyarrhythmia. Apropos of 4 clinical cases].

This is a report about four patients with tachyarrhythmias successfully treated with intravenous magnesium sulfate. In two cases (supraventricular tachycardia and torsade de pointes) because they were resistant to other antiarrhythmic drugs, and in the remaining two cases (paroxistic atrial fibrillation) because they presented characteristic features of magnesium depletion. The efficacy, the rapid onset of action and the absence of adverse reactions must be emphasized and the authors suggest that larger and randomized trials should be carried out, in order to establish the real place of magnesium sulfate in the antiarrhythmic armamentarium.

Adult↗

Experimental allergic encephalomyelitis (EAE): role of B cell and T cell epitopes in the development of EAE in Lewis rats.

Studies from our laboratory have shown that classical clinical and histological signs of experimental allergic encephalomyelitis (EAE) may be induced in Lewis rats by synthetic peptides S49 or S55. Peptides S49S and S55S are defined by residues 69-84 and 72-84 of the guinea pig myelin basic protein (MBP), respectively. Peptide S53 (residues 75-84 of the guinea pig MBP), six residues shorter than S49S at the N-terminal end, induced mild clinical signs of disease unaccompanied by hind leg paralysis, incontinence, or central nervous system pathology. In contrast, peptide S67 (residues 69-81 of the guinea pig MBP), three residues shorter than S49S at the C-terminal end, did not induce either clinical or histological signs of EAE despite the fact that the S67-sequence houses an epitope known to induce cell-mediated immunity. Peptides S49S, S55S, and S53 are antigenic and gave rise to antibodies that recognized either of the three peptide sequences. In this report we explore the interrelationship between cellular immunity induced by the S67 sequence and humoral immunity, induced by the S53 sequence and the development of classical clinical and histological signs of EAE. The results show that the nonencephalitogenic sequence of S67 may be rendered encephalitogenic in the presence of antibody directed against the S53 sequence. Lewis rats immunized with S53 developed pathological signs of EAE only after they were challenged with S67. The fact that a simultaneous challenge with S67 and S53 was as effective in inducing EAE pathology as a delayed one (up to 40 days) suggests that the cellular response to S67 is dependent upon the humoral response to S53.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

Alveolar septal changes in pulmonary edema: a subcellular study of lung clearance in the dog.

Left lobe lung biopsies were obtained in dogs allowed to breathe in atmospheres of coal or barium sulphate dust before ligature of the left pulmonary veins and at 15 min, 1, 5, 7, 15, and 30 days after ligature. All samples were prepared for transmission electron microscopy (TEM) and scanning electron microscopy (SEM); in addition, samples from the barium sulphate group were examined by electron diffraction analysis (EDA). Two main phagocytic cell types were identified. In addition lymphatic capillary-like structures were observed in the alveolar septum after ligature of the pulmonary veins.

Animals↗

Biological activity of region 65-102 of the myelin basic protein.

Region 65-102 of the myelin basic protein (MBP) houses a number of antigenic determinants known to induce delayed-type hypersensitivity, experimental allergic encephalomyelitis (EAE), suppressor cell function, and antibodies. In this report we describe the biological activity of synthetic peptides S53, S55, and S49 with sequence homology to region 69-84 of the rat, guinea pig, and bovine MBP. Peptide S53-A, defined by residues 75-84 of the guinea pig (SQRSQDEN) and of the rat (SQRTQDEN) MBP induced clinical signs of disease in Lewis rats. These included weight loss, flaccid tail, "muscle wasting," and hind-leg weakness. Histological examination of brain, spinal cord, and sciatic nerve sections of diseased rats revealed the complete absence of focal and perivascular lymphocytic infiltrates characteristics of demyelinating EAE lesions. Elongation of peptide S53 by three or six residues to residue sequences naturally found at its N-terminal end gave rise to peptides S55S (PQKSQRSQDEN) and S49S (GSLPQKSQRSDQDEN), respectively. Lewis rats challenged with either S55S or S49S developed classical clinical and histological signs of EAE. Severe hind-leg paralysis was accompanied by incontinence and sometimes death. Injected in the form of carrier-free peptide, S53 was a meager B cell immunogen. S53 conjugated with methylated-bovine serum albumin was also a potent immunogen and produced clinical signs of disease without CNS pathology. By comparison, carrier-free S55S and S49S were potent immunogens giving rise to antibodies that cross reacted completely and competitively with S55S but considerably less so with S53. The results show that the sequence of S53 defines an epitope responsible for the formation of anti-S53 antibodies. Elongation of the S53 sequence at its N-terminal end generated an additional epitope which induced cell-mediated immunity responsible for the concomitant development of pathological signs of EAE. It may be concluded that the induction of classical signs of EAE requires specific and defined sequences capable of expressing both B cell and T cell functions.

Amino Acid Sequence↗

The lymphatic vessels of the lung: morphological study.

The authors studied the anatomical structures of the pulmonary lymphatic vessels in the dog and in man using injection techniques and macro- and microangiographic and histological methods. The results show that injection in the basal lobes is easier than in the apical lobes. The dog, an animal with a thin pleura, has a very dense superficial lymphatic network, like man. The superficial and the deep lymphatic vessels are connected through the pleural septa.

Animals↗

The development of experimental allergic encephalomyelitis with immunizing doses of myelin basic protein.

Rabbits immunized with low (11.25 mg) and high (57.50 mg) doses of myelin basic protein from several species develop antibasic protein antibodies, delayed type hypersensitivity, and clinical and pathological signs of experimental allergic encephalomyelitis. More than 55% of rabbits immunized with relatively high doses of basic protein develop disease. The absence of circulating antibasic protein antibodies in immunorespondent animals is associated with the appearance of clinical or histological signs of experimental allergic encephalomyelitis; however, the presence of humoral antibodies did not prevent completely the development of disease. Delayed-type hypersensitivity, specific for the basic protein, appears as early as 5 days after immunization and is maintained in nondiseased and surviving animals. Neither excess encephalitogen nor encephalitogen-induced antibody is sufficient to suppress completely the eventual development of clinical or histological manifestations of disease.

Animals↗

Establishment of primary cultures of rat and human parotid epithelial cells for transfection experiments.

The molecular mechanisms that regulate the synthesis of salivary proteins are unknown. The paucity of homogeneous cell populations of parotid acinar cells has become a limiting factor for such a study. Therefore, the establishment of immortalized clones of acinar cells is essential. This study has established primary cultures of rat and human parotid epithelial cells that are suitable for transfection with plasmid vectors, pSV2, pSV3, and pSV5 to generate immortalized cells in vitro. Among various techniques used, the rat and human parotid tissue or cellular clumps when restrained in chicken plasma clot allowed the outgrowth of epithelial cells that maintained epithelial cell morphology for over 4 wk. However, the initial growth requirements for rat and human parotid cells were different. The presence of 10% heat inactivated fetal bovine serum in supplemented MCDB-LB medium was essential for the outgrowth of rat parotid epithelial cells, but this was not needed for the outgrowth of human parotid epithelial cells. The growth of both human and rat parotid epithelial cells can be maintained in serum-free supplemented MCDB-LB. These primary cultures contained amylase-producing cells as demonstrated by immunofluorescent technique, and they were transfected with pSV2, pSV3, and pSV5 using primarily the calcium phosphate-DNA co-precipitation technique. After initial extensive cell death, many cells with epithelial cell morphology survived.

Animals↗

Erectile dysfunction and HTLV-I infection: a silent problem.

The human T-lymphotropic virus type I (HTLV-I) is a retrovirus associated with a chronic myelopathy known as HTLV-I-Associated Myelopathy or Tropical Spastic Paraparesis (HAM/TSP). The main objective was to assess the frequency of erectile dysfunction (ED) in HTLV-I-infected individuals from Salvador and other cities from Bahia, Brazil, as well as to verify if sexual dysfunction correlates with urinary symptoms and overall neurological impairment. From January 2001 to April 2004, 218 HTLV-I carriers (111 male and 107 female subjects) had complete clinical, neurological, and urological evaluation. They were assessed using standardized questionnaires to determine urinary complaints (Urinary Distress Inventory) and ED (Brief Male Sexual Function Inventory). Neurological impairment was established by Expanded Disability Status Scale (EDSS) from 0 to 10. HAM/TSP was considered as EDSS> or =2. A total of 17 males had clinically defined HAM/TSP (group 1). From the 94 HTLV-I-infected males, 62 were selected (group 2) and paired by age with patients in group 1. A total of 79 individuals were selected for this study. The age ranged from 35 to 81 y (mean=47.9+/-9.65). The percentage of ED in the studied population was 40.5%. In the HAM/TSP group, ED frequency was 88.2%. The associations among sexual dissatisfaction, erectile dysfunction, urinary symptoms (frequency, nocturia, and urgency) and EDSS> or =2 were statistically significant. In HAM/TSP, there is a slow and progressive degeneration of the lateral funiculus of the spinal cord. HTLV-I-infected individuals present a high frequency of ED and it is closely associated to urinary symptoms and the overall neurological picture. The HTLV-I carriers already had prominent compromise of the sexual activity.

Adult↗

Relationship between adenosine 3',5'-cyclic monophosphate level, cell proliferation, and alpha-amylase in rat parotid.

Treatment of rats with isoproterenol (IPR, beta 1- and beta 2-agonist), dobutamine (beta 1-agonist), and terbutaline (beta 2-agonist) increased the cAMP level and cell proliferation, but it decreased alpha-amylase activity in parotid glands. Terbutaline was relatively less effective. Alpha-Amylase activity as determined by substrate hydrolysis was maximally depressed (85% of control) after 15 min of IPR treatment; however, alpha-amylase level as determined by Western immunoblotting with the primary antibody to alpha-amylase decreased maximally after 2 h of treatment. The level of alpha-amylase significantly decreased after 15 min of treatment, but the levels of alpha-amylase mRNAs of 702 and 1176 base pairs (bp) slightly increased at this time. This suggests that an increased rate of transcription or a decreased rate of degradation of alpha-amylase mRNAs without a proportional increase in the rate of translation of alpha-amylase occurs in parotid glands after treatment with IPR. The levels of alpha-amylase mRNAs decreased after 2 h of treatment; however, the level of alpha-mRNA of 702 bp continued to decline, but the level of alpha-mRNA of 1176 bp increased at 3 days after IPR treatment. The level of actin mRNA of 2200 bp increased at 15 min and remained elevated during the entire observation period. Results showed that IPR-induced elevation of cAMP increases cell proliferation, and alters the level and activity of alpha-amylase and the expression of alpha-amylase genes at different rates.

Actins↗

Environmental contamination by Toxocara sp eggs in public areas of Salvador, Bahia State, Brazil.

A survey of parasite eggs and cysts in soil and dog feces collected in public places of 23 boroughs of Salvador, a city in the Northeast of Brazil, was performed. High degree of contamination by Toxocara sp eggs was observed in all boroughs studied; other parasites found included: Ascaris lumbricoides, hookworms, whipworms and protozoan cysts. Parks and public gardens were more contaminated than streets and beaches for all parasites, including Toxocara sp.

Animals↗

[Effectiveness of aminosidine sulphate in severe visceral leishmaniasis, resistant to the treatment with pentavalent antimony].

A grave kala-azar infection in a 14 years old boy is described. The leishmanial infection failed to respond to ten interrupted courses of glucantime of variable duration (14-56 days) at a dose of 20mg Sb5/kg/day. However a favorable response occurred to intramuscular aminosidine sulphate (20mg/kg/day) for 20 days. This same regimen was repeated 20 days later. After the first treatment splenic puncture parasite density fell from 50 amastigotes per oil immersion field to 3 amastigotes in 10 fields. A further splenic puncture 7 months after treatment was negative. The marked hepatoesplenomegaly gradually resolved over 26 months follow up and he gained 13 kilograms in weight. After aminosidine sulphate therapy his Montenegro reaction become positive and his lymphocytes responded to leishmania antigens.

Adolescent↗

[Dysembryoplastic neuroepithelial tumors].

INTRODUCTION: The dysembryoplastic neuroepithelial tumors tend to occur in young patients, with partial complex partial seizures which is refractory to medical treatment. These are stable lesions, with defined histological features, specially with clinical data corroboration. CLINICAL CASES: The clinical, imagiological, operative, and histopathological data of six patients with proved dysembryoplastic neuroepithelial tumors were reviewed. All patients had seizures with age at onset ranged from 7 to 27 years. Five lesions were located in the temporal lobe and one in the parietal lobe. Common features included cortical to subcortical location, low density in CT-scan, very low signal intensity on T1-weighted images and high signal on T2-weighted images. Calcification occurred in two lesions, and three showed contrast enhancement. Complete resection of the tumor was performed in three cases, and subtotal resection in other three cases. Pathological features included oligodendroglial-like cells, glioneural component, and few cases showed dysplastic cortical disorganization. The postoperative period of follow-up ranged from 2 to 18 months. Four patients were seizure free, two of which had subtotal resection of the lesion. The remaining two patients maintained seizures. CONCLUSIONS: The clinical, imagiological and histopathological data of the six cases presented are generally compatible with those of the reports reviewed by the authors. The imagiological features are nonspecific. Surgical treatment permits histological diagnosis and epilepsy control.

Adolescent↗

Fine silver staining analysis of the nucleolar organizer regions during oogenesis in Penaeus kerathurus (Crustacea, Decapoda).

In previtellogenic oocytes, nucleoli showed segregated components, with the dense fibrillar component (DFC) appearing highly developed and presenting several fibrillar centers (FC). The granular component (GC) was less developed and formed a wide-spaced reticulum. Only the DFC appeared stained by silver, with higher intensities being found at its periphery. During early vitellogenesis, the nucleolar components were kept segregated but both the DFC and the GC enlarged, without evident changes being noticed in the silver staining pattern. In mid and late vitellogenesis, the nucleoli showed integrated components, with the DFC being intermeshed with the GC. Both nucleolar components were highly developed, no evident FC were noticed, and silver stained the DFC in a heterogeneous pattern. During cortical vesicle formation, the nuclear chromatin condensed and nucleoli appeared disintegrated, showing high levels of accelerated exportation of silver stained materials. Results suggest that the size of the DFC is kept high and the size of the GC kept low (low rDNA transcription levels and RNP exportation accelerated), in the segregated nucleoli of the previtellogenic oocyte, as the cell stores nuages but shows absence of rough endoplasmic reticulum and thus low protein svnthesis; that the size of the DFC and of the GC is increased in the segregated nucleoli of early vitellogenic oocytes (intermediate levels of rDNA transcription and of protein synthesis), which is in accordance with the appearance of the rough endoplasmic reticulum and of yolk vesicles formed with endogenous and exogenous sources; that during mid and late vitellogenesis the DFC and the GC appear highly developed and integrated (high levels of rDNA transcription and of protein synthesis) as the rough endoplasmic reticulum expands and the large yolk vesicles grow by endogenous synthesis; and that chromatin condense and nucleoli disintegrate (very low levels of rDNA transcription with accelerated RNP exportation) when cortical vesicles are formed.

Animals↗