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Biomedical subjects

A C Alves

Publications and source records attributed to A C Alves.

At least 37 records · Page 2Linked to original sources
PubMed1994

Partial purification of an endoglucanase from Biomphalaria glabrata.

Previous studies have shown that Biomphalaria glabrata contains a complete cellulolytic system which includes an endoglucanase, an exoglucanase and a beta-glucosidase. In the present report, a scheme for the purification of the endoglucanase from this invertebrate is proposed. Two major problems were encountered during the study: 1) the presence of a green-brownish pigment, which could not be eliminated by thermal shock or ammonium sulfate precipitation and 2) relative instability of enzymatic activity. Various alternatives were tested and the best sequence of steps was: 1) a sample of the crude extract, obtained by homogenization of the digestive glands in 50 mM Tris-HCl buffer, pH 8.4, and ultracentrifugation, was applied to a Q-Sepharose FPLC column (50 mM Tris-HCl buffer, pH 8.4; 10 mm x 22.2 cm column; flow rate 1.5 ml/min; 0.1 to 0.5 M NaCl gradient); 2) the eluate peak containing activity was dialyzed, lyophilized and eluted from a Superdex-75 gel filtration FPLC column (50 mM ammonium acetate buffer, pH 4.8; 16 mm x 60 cm column; flow rate 1.0 ml/min). A low degree of purification (about 36-fold) and recovery (about 12%) were observed, probably due to enzyme instability. SDS-electrophoresis of the active fraction showed a major peak of 30 kDa. In order to improve the purification scheme, further studies are required to stabilize this enzyme during purification and storage.

Animals↗
PubMed1993

Association of malignancy and Langerhans' cell histiocytosis: report of three cases.

Among 44 children with Langerhans' cell histiocytosis (LCH) seen at the Pediatric Department of the A.C. Camargo Hospital, São Paulo, Brazil, three developed malignancy, two before and one after the diagnosis of LCH. Malignancy could be attributed to treatment in one of the three children. Whether the cancer in the other two children represents a chance association of the two processes or is treatment-related, is unknown.

Child↗
PubMed1992

Pharmacological modulation of the late eosinophilia induced by antigen in actively sensitized rats.

The intrathoracic injection of ovalbumin (12 micrograms/cavity) into actively sensitized rats led to a long-lasting eosinophil recruitment, which appeared 24 h after stimulation. In this study, pharmacological antagonists were used in order to evaluate the potential involvement of arachidonic acid metabolites and PAF-acether in the pleural eosinophil accumulation by antigen. Administration of the cyclooxygenase inhibitor indomethacin (2 mg/kg, i.p.), 1 h before the antigen challenge, failed to modify the 24-hour eosinophilia. In contrast, the dual cyclooxygenase and lipoxygenase inhibitor BW 755C and the more selective inhibitor BW A4C (5 and 10 micrograms/cavity, i.t.), injected 1 h before the antigen, were effective. Similarly, the PAF-acether antagonists BN 52021 and WEB 2086 (20 mg/kg, i.p.) abrogated the eosinophil accumulation, which was also sensitive to the topical treatment with the glucocorticoid dexamethasone (5 and 10 micrograms/cavity). Our findings suggest that the antigen-induced eosinophil mobilization is dependent on lipoxygenase derivatives and PAF-acether, but not on prostaglandins.

Animals↗
PubMed1990

Carcinoma of the vulva. Clinicopathologic factors involved in inguinal and pelvic lymph node metastasis.

Eighty-five women with vulvar squamous cell carcinoma were subjected to radical vulvectomy with bilateral inguinal and femoral node dissection or to radical vulvectomy with bilateral inguinofemoral and deep pelvic node dissection. The association between lymph node status (metastatic or not) and several parameters was analyzed: tumor location, size and clinical stage; tumor thickness, histologic grade and mitotic index; blood vessel, lymphatic and perineural infiltration; and lymphocytic and plasma cell infiltrates. There were no metastases to the pelvic lymph nodes without previous inguinal lymph node involvement. Unilateral vulvar carcinomas did not have contralateral metastatic nodes when there was no ipsilateral nodal involvement. Lymphatic vessel infiltration showed a statistically significant correlation with inguinal node metastases (P less than .05). No correlation was found between lymph node metastasis and tumor size, clitoral invasion, tumor thickness, histologic grade, blood vessel and perineural infiltration, lymphocytic and plasma cell infiltrates, and mitotic index.

Adult↗
PubMedDate not supplied

Immunocytochemical study of malignant lymphoma in serous effusions.

OBJECTIVE: To cytologically evaluate a large series of serous effusions associated with malignant lymphoma (ML), identify the immunoreaction patterns of the cells from selected positive cases and to investigate the correlation of cytomorphology with tissue section diagnosis. STUDY DESIGN: From 1966 to 1990, a review of the files of the Department of Anatomic Pathology, A. C. Camargo Hospital, disclosed 4,297 cases of serous effusions, 256 of which were associated with ML. Cytopathologically positive cases were selected for immunocytochemical study. All paraffin sections stained with hematoxylin and eosin were reviewed to confirm the malignancy of the cases. Immunostaining was performed on both cytocentrifuge slides previously stained with Papanicolaou stain and new sections of the biopsy samples using the immunoperoxidase method and avidin-biotin complex with monoclonal mouse antihuman B-cell marker L-26 and monoclonal (mouse) antihuman T-cell marker UCHL-1. RESULTS: Immunocytochemical reactions were performed in 54 cases: 22 were pan-B positive and 10 pan-T positive; 24 cases showed no reactivity for either monoclonal antibody. Immunohistochemical reactions were performed in 24 available cases: 15 were pan-B positive and pan-T positive; 3 cases showed no reactivity for either monoclonal antibody. Cytohistoimmunoreactions were similar in 11 pan-B positive cases and 2 pan-T positive cases. Three cases were negative for both markers, 4 cases were pan-T positive in tissue samples and negative in cytocentrifuge smears, 3 cases were pan-B positive in tissue and negative on cytology and 3 cases were negative for both markers in both tissue and cytologic specimens. CONCLUSION: Cytology is an effective method of evaluating serous effusions associated with malignant lymphoma: no false positive diagnosis was observed in this series. Immunophenotyping of lymphoid cells is useful to classify and confirm the cytologic diagnosis.

Animals↗
PubMedDate not supplied

Chordoma: retrospective analysis of 24 cases.

INTRODUCTION: Chordoma is a rare and slow-growing tumor, with local aggressiveness and preferential localization in the vertebral column. OBJECTIVE: The main objective of this study is to evaluate natural history and results of treatment of chordomas. METHODOLOGY: This is a retrospective study from 1953 to 1993. MATERIAL AND METHODS: The age ranged from 2 to 86 years (mean = 34.5). Twelve patients were male and 12 female. The localization of the tumor was: 20 in the sacral region, 3 in head and neck and one out of the spine. RESULTS: The treatment, alone or combined, was surgery, radiation therapy and chemotherapy. The survival rate for patients with lesions in the sacrum ranged from 4 to 119 months, since the date of the symptoms. The 5-year overall survival was 4.2%. CONCLUSION: Chordoma is a rare and slow growing tumor, with a very difficult approach by surgery due to its preferential location in the sacrum and poor therapeutic results with radiation therapy or chemotherapy, mainly in patients with advanced disease.

Adolescent↗
PubMedDate not supplied

[Prevalence of normal occlusion traits in deciduous dentition].

The aim of this research was to study the normal occlusal patterns of deciduous dentition in Brazilian preschool children. The sample consisted of 356 preschool children, of both genders, aged 3-5 1/2 years from the urban zone of Salvador, Bahia. The occlusion exam was carried out by two examiners, in the classroom, utilizing a wooden spatula. The data were analyzed by the statistical program EPI-INFO 6.02 using the Chi-squared test. The frequency of the type I arch was 43.3% for the upper and 46.3% for the lower arch. The frequency of the type II arch was 56.7% for the upper and 53.75 for the lower arch, however, no difference between genders was noticed. The distribution of primate spaces was: 89.9% for the upper and 67.1% for the lower arch. This prevalence decreased significantly as age increased (p < 0.01). Normal canine relationship was found in almost 60% of the children for the right and left sides. Out of 712 evaluated terminal planes, 55.9% presented mesial terminal step for the primary second molars, 37.9% straight terminal plane and 6.2% distal step. The results permitted to conclude that the presence of generalized spacing between incisors, commonly described by other authors, was not the most prevailing condition for both arches in this sample. On the other hand, primate spaces were the most common ones. The most frequent normal occlusal patterns for canine and molar relationships were found to be the Class I patterns.

Child, Preschool↗
PubMedDate not supplied

[Contribution to the study of dental caries in 0-30-month-old infants].

This study evaluated the oral health conditions of 340 children, aged 0-30 months (21.3 +/- 5.6)--54.4% of girls and 45.6% of boys--from 20 public day nurseries of Salvador (Brazil), as to the presence of incipient carious lesions. The exam was carried out by a single examiner, who utilized a mirror, a probe and a penlight. The teeth were wiped with gauzes in order to remove the dental plaque. A questionnaire was answered by the children's parents or caretakers in order to assess information regarding knowledge on caries, caries risk factors, socioeconomic status of the family and utilization of fluoride. Two hundred and twenty-nine answered questionnaires (67.35%) were obtained. The observed lesions were classified in five stages, according to their severity (C0-C4; active/inactive). The data were analyzed using the Epi-info 6.02. The prevalence of caries was 55.3% when all stages were registered: 25% for subjects aged 0-12 months, 51.18% for subjects aged 13-24 months and 71.03% for those aged 25-30 months (chi 2 = 25.31, p < 0.01). When only active white spots were considered, 49.7% of the children were affected; 17.6% of the children presented with cavitated lesions. Among the affected children, 90.96% had lesions only on anterior teeth: 80% of the lesions were white spots and 20%, cavities. No significant difference was observed between genders. The increased amount of biofilm was positively associated with dental decay in toddlers (chi 2 = 67.61, p < 0.01), and the number of affected children increased when the sleep-time nursing habit was present (chi 2 = 0.24, p = 0.62). The prevalence of lesions increased with age and with the number of erupted teeth (chi 2 = 25.31, p < 0.01; chi 2 = 122.95, p < 0.01). Early oral health attention, diagnosis of incipient lesions, as well as educative and preventive programs to change oral hygiene and dietary habits are suggested.

Dental Caries↗
PubMedDate not supplied

[Relationship between obesity and educational level in Portuguese young males in 1990].

OBJECTIVE: To evaluate the relationship between the educational level, weight and obesity of young Portuguese males, aged 20 years. DESIGN: Cross-sectional study, based on the national military census files of 1990, provided by the military selection centres of Portugal (north, centre, south--including Azores and Madeira islands). SUBJECTS AND METHODS: In Portugal, all males aged 20 must present themselves to the military authorities to be submitted to a health exam in order to be screened for the armed forces. The data of 70,858 young Portuguese males aged 20 were gathered. Height and weight were measured by skilled teams. The educational level was confirmed by the presentation of educational attainment certificates. The population was divided into deciles of body mass index (BMI). The whole group was classified as obese or non-obese, according to a cut-off point of 27.8 Kg/sqm. The educational level was classified in four groups: group A--less than 5 years of schooling; group B--5 to 6 years; group C--7 to 9 years; group D--> or = 10 years. The level of education in each decile of BMI was determined and the percentage of obese subjects was calculated for each level of schooling. The odds of obesity associated with each group of schooling was determined as well as their 95% confidence intervals. Statistical significance was considered to exist when p < 0.05. RESULTS: The average BMI in the study population was 22.5 Kg/sqm. A slight increase in schooling was noticed from the lowest to the highest decile of BMI. The same result was obtained when we analysed the upper extreme of the BMI distribution in greater detail. According to our criteria for obesity, the percentages of obesity in each level of schooling were as follows: group A--4.2%; group B--5%; group C--5.1%; and group D--5.4%. The odds ratio (OR) of obesity according to each education level was higher in those with a higher level of education. In fact, those with 10 or more years of schooling presented an OR = 1.05(0.94;1.17) which was not statistically significant (ns) when compared to those with 7-9 years; while an OR = 1.08(0.97;1.21), was also ns when compared to those with 5-6 years, and, finally, an OR = 1.29(1.14;1.47) was statistically significant (p < 0.001) in comparison to those with only 0-4 years of schooling. CONCLUSIONS: As major conclusions one can say that the prevalence of obesity is low among young Portuguese males (4.9%), only 2.1% with a BMI > 30 Kg/sqm. Furthermore, our results show that, in Portugal, contrary to the results found mostly in western European countries, males aged 20 years with higher levels of education are slightly more prone to be obese than others with lower levels of schooling.

Adult↗
PubMedDate not supplied

Histological study of the endometrium in menopausal women with breast carcinoma.

The first reference concerning the multiple primary malignant neoplasms was made by Bilroth, 1880 and since then a large number of studies have been published. Furthermore, an increasing incidence of simultaneous cancers are currently observed (16,18). At the same time, several retrospective populational studies evidenced the association between breast and endometrium carcinoma. It is well known that both uterus and breast are hormone-dependent organs and are likely to be influenced by the same oncogenic stimulus, either of endocrine nature or dietary origin (2, 3, 14). The risk of developing endometrial carcinoma is higher in patients already affected by breast neoplasm and is much more evident in older women within the first five years following the diagnosis of breast tumor. Conversely, patients with endometrial carcinoma may present a second mammary neoplasm and the relative risk is around 2.0 (1, 17). Although the existence of a correlation between these two primary malignant neoplasms is clearly observed, the absence of systematic studies directed to the screening of endometrial cancer in women with breast carcinoma is surprising. This study deals with histological analysis of the endometrium of postmenopausal patients with breast cancer and aims to determine the possible changes that might have occurred in the onset of the disease.

Brazil↗