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Biomedical subjects

M C Almeida

Publications and source records attributed to M C Almeida.

At least 19 recordsLinked to original sources
PubMed2006

Guava extract (Psidium guajava) alters the labelling of blood constituents with technetium-99m.

Psidium guajava (guava) leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents (BC) are labelled with technetium-99m ((99m)Tc) and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with (99m)Tc. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with (99m)Tc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with (99m)Tc after the percentage of incorporated radioactivity (%ATI) in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with (99m)Tc. The data showed significant (P<0.05) alteration of ATI in BC from blood incubated with guava extract.

Animals↗
PubMed2001

Role of nitric oxide in insulin-induced hypothermia in rats.

Hypothermia is a well-known phenomenon which accompanies hypoglycemia in mammals. The present study was designed to test the hypothesis that nitric oxide (NO) plays a role in insulin-induced hypothermia. The body temperature (Tb) of awake, unrestrained rats was measured before and after systemic infusion of insulin (2U x kg(-1) x h(-1)), and intracerebroventricular administration of NG-nitro-(L)-arginine methyl ester (L-NAME, a nonselective NO synthase inhibitor, 200 microg/1 microl). We observed a significant reduction in body temperature after insulin infusion. L-NAME alone caused no significant change in body temperature. When the two treatments were combined, no change in Tb was observed. The data indicate that NO plays a key role in insulin-induced hypothermia.

Animals↗
PubMed2001

Impact of an integrated adolescent reproductive health program in Brazil.

An impact evaluation of an integrated school- and health-clinic-based adolescent reproductive health initiative was undertaken by the State Secretariats of Health and Education in Bahia, Brazil during 1997-99. The project was initiated in response to continued high pregnancy rates among adolescents and growing numbers of new HIV infections among young adults. It sought to promote responsible sexual and health-seeking behaviors among public secondary-school students, including the use of public health clinics. The study design included a matched control group used to measure project impact. The findings indicate that the project was successful in increasing the flow of sexual and reproductive health information to secondary-school students and that it had an impact on adolescents' intentions to use public health clinics in the future. No effects on sexual or contraceptive-use behaviors or on use of public clinics were observed, however. Client exit-interview data from a subset of project clinics indicate that adolescents who use clinic-based services are overwhelmingly female and considerably older on average and much more likely ever to have been pregnant than are adolescents in the target population for the project.

Adolescent↗
PubMed2001

Hypertension in a female nursing staff--Pattern of occurrence, diagnosis, and treatment.

OBJECTIVE: To report the pattern of occurrence, diagnosis, and treatment of hypertension in a female nursing staff of an emergency hospital. METHODS: We carried out a cross-sectional study that included interviews and blood pressure measurements of 494 nursing professionals at an emergency hospital in the city of Salvador, in the state of Bahia, Brazil. We considered hypertensive all individual with blood pressure > or = 140/90 mmHg or normal pressure if on regular treatment. RESULTS: We found a prevalence of hypertension of 36.4%. Only 18.3% of the individuals ignored their hypertensive condition, and 64.2% admitted not being having regular treatment. Of those individuals who were having treatment, 69.4% had elevated blood pressure on examination. The major reasons for not being on treatment was the occasional elevation of blood pressure (22.2%) and medical counseling (20.0%). CONCLUSION: The results point to the need to introduce hypertension control measures in this occupational group, because of the magnitude of the disease and the potential impact on diffusion of knowledge and measures to control hypertension.

Adult↗
PubMed2000

Inhibition of the central heme oxygenase-carbon monoxide pathway increases 2-deoxy-D-glucose-induced hypothermia in rats.

The present study was designed to test the hypothesis that carbon monoxide (CO) plays a role in 2-deoxy-D-glucose (2-DG)-induced hypothermia. The body temperature (T(b)) of awake, unrestrained rats was measured before and after systemic administration of 2-DG (50 mg/kg) and intracerebroventricular administration of zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG, a heme-oxygenase inhibitor, 200 nmol/4 microl). We observed a significant reduction in body temperature after 2-DG injection. ZnDPBG alone caused no significant change in body temperature. When the two treatments were combined, 2-DG-induced hypothermia was significantly increased. The data indicate that heme oxygenase-carbon monoxide pathway plays a key role in 2-DG-induced hypothermia, inhibiting 2-DG-induced hypothermia.

Animals↗
PubMed1999

Tolerance to lipopolysaccharide is related to the nitric oxide pathway.

Repeated administration of lipopolysaccharide (LPS) induces a refractory state to its usual pyrogenic effects which is called endotoxin tolerance. We tested the hypothesis that nitric oxide (NO) participates in the endotoxin tolerance. Single injection of LPS resulted in an elevation in body temperature (Tb), whereas a significant reduction of the thermoregulatory response to LPS was observed to repeated administration of LPS (administered at 48 h intervals). Intracerebroventricular (i.c.v.) injection of L-NAME (a non-selective NO inhibitor of nitric oxide synthesis) markedly enhanced the febrile response to LPS in tolerant rats. The data suggest that NO pathway in the central nervous system plays a role in endotoxin tolerance.

Animals↗
PubMed1999

Role of nitric oxide in 2-deoxy-D-glucose-induced hypothermia in rats.

The present study was designed to test the hypothesis that nitric oxide (NO) plays a role in 2-deoxy-D-glucose (2-DG)-induced hypothermia. The body temperature of awake, unrestrained rats was measured before and after the administration of 2-DG, or N(G)-nitro-L-arginine methyl ester (L-NAME; a non-selective NOS inhibitor) or both treatments together. We observed a significant reduction in body temperature after 2-DG injection. L-NAME alone caused no significant change in body temperature. When the two treatments were combined, a reduction in the magnitude of 2-DG-induced hypothermia was observed. The neuronal NOS inhibitor 7-nitroindazole also inhibited 2-DG-induced hypothermia. The data indicate that NO, probably produced by neuronal NOS, plays a role in 2-DG-induced hypothermia.

Animals↗
PubMed1999

Role of nitric oxide in hypoxia inhibition of fever.

Hypoxia causes a regulated decrease in body temperature (T(b)), and nitric oxide (NO) is now known to participate in hypoxia-induced hypothermia. Hypoxia also inhibits lipopolysaccharide (LPS)-induced fever. We tested the hypothesis that NO may participate in the hypoxia inhibition of fever. The rectal temperature of awake, unrestrained rats was measured before and after injection of LPS, with or without concomitant exposure to hypoxia, in an experimental group treated with N(omega)-nitro-L-arginine (L-NNA) for 4 consecutive days before the experiment and in a saline-treated group (control). L-NNA is a nonspecific NO synthase inhibitor that blocks NO production. LPS caused a dose-dependent typical biphasic rise in T(b) that was completely prevented by hypoxia (7% inspired oxygen). L-NNA caused a significant drop in T(b) during days 2-4 of treatment. When LPS was injected into L-NNA-treated rats, inhibition of fever was observed. Moreover, the effect of hypoxia during fever was significantly reduced. The data indicate that the NO pathway plays a role in hypoxia inhibition of fever.

Animals↗
PubMed1998

Cutinase purification on poly(ethylene glycol)-hydroxypropyl starch aqueous two-phase systems.

The partition behaviour of cutinase on poly(ethylene glycol) (PEG)-hydroxypropyl starch aqueous two-phase systems was characterized. The effect of molecular mass of PEG, the pH of the system and tie-line length on cutinase partition coefficient and cutinase yield to the top phase was investigated for systems prepared with a purified hydroxypropyl starch (Reppal PES 100) and a crude one (HPS). The effect of the presence of different salts, such as sodium chloride, sodium sulphate and ammonium sulphate, on cutinase partition was also studied. The results lead to the conclusion that aqueous two-phase systems composed of PEG and hydroxypropyl starch are not efficient in the purification of cutinase. In the majority of cases, the partition coefficients were very close to 1, with pH being the factor which affects most cutinase partition. Partition coefficients were significantly improved when salts were added to the systems. For PEG 4000-Reppal PES 100 [at pH 4.0; 0.5 M (NH4)2SO4], the partition coefficient for cutinase was 3.7, while a value of 12 was obtained for PEG 4000-HPS (at pH 4.0; 1 M NaCl). An isoelectric point (pI) of 7.8 was confirmed for cutinase by constructing a cross partition graphic from the results obtained in the experiments with different salts.

Carboxylic Ester Hydrolases↗
PubMed1996

Dissemination of Leishmania (Viannia) braziliensis.

Destructive human mucocutaneous leishmaniasis may appear many years after the primary cutaneous infection with Leishmania (Viannia) braziliensis. Hamsters (Mesocricetus auratus) were infected with metacyclic L. braziliensis promastigotes. It was found that secondary metastatic visceral lesions could arise from a primary cutaneous lesion, or secondary cutaneous lesions from a primary visceral lesion. Parasites in the viscera were shown to be viable, multiplying and capable of metastasis to either secondary visceral or cutaneous sites. The finding of an early metastasis in the wall of a small cutaneous vessel indicates that dissemination can occur by the haematogenous route. Slow growing organisms in viscera may thus be a source for late metastasis to mucocutaneous sites or for systemic relapse after immunosuppression.

Animals↗
PubMed1992

Traumatic injury to the spinal cord. Prevalence in Brazilian hospitals.

Traumatic spinal cord lesions have a worldwide high morbidity and mortality, and in many developed countries the problem has received special attention, based on epidemiological studies. In Brazil these studies have been restricted to institutional data. In 1988 a survey conducted by the Integrated System of Traumatology and Orthopaedics, covering 36 public hospitals from 7 Brazilian capitals, revealed a point prevalence of 8.6% (108 patients) with spinal cord injury, aged from 6-56 years; 81% were men. The most frequent causes were traffic accidents (42%), firearms (27%) and falling from heights (15%). The main complications were pressure ulcers (54%) and urinary infections (32%).

Adolescent↗
PubMed1992

A scale to measure restrictiveness of living environments for troubled children and youths.

Despite concerns about the restrictiveness of care and treatment procedures and settings for special populations, the concept of restrictiveness has seldom been defined or measured. This study describes the development of the Restrictiveness of Living Environments Scale (ROLES) for measuring the restrictiveness of residential settings for children and youths, including their own homes. Based on a literature review, the authors defined restrictiveness in terms of limits placed on freedom of movement or choice by the physical facility, by rules or requirements, and by conditions of entry and departure. The definition, along with a list of 27 residential settings for children, was sent to 389 child care professionals, who were asked to rate the restrictiveness of the settings on a 10-point scale, using a rating method designed to yield an interval scale. Ratings from 159 respondents, rounded to the nearest .5, were used to determine the relative position of the settings on the scale.

Activities of Daily Living↗
PubMed1992

Promoting reciprocal interactions via peer incidental teaching.

This study evaluated peer incidental teaching as a strategy for increasing reciprocal peer interactions by children with autism. Three typical preschoolers were trained as peer tutors for 3 young children with autism. During a classroom free-play session, peer tutors used incidental teaching to obtain verbal labels of preferred toys by children with autism. A multiple baseline across the 3 target children showed replicated positive effects of the intervention. Adult supervision and assistance were then faded systematically, with resulting maintenance of increased reciprocal interactions. Multiple measures of the extent and limits of generalization suggested that 1 child increased interactions in free-play periods throughout the day, but none of the children showed increases at lunch. Teacher and peer ratings supported the social validity of positive findings.

Autistic Disorder↗
PubMed1991

Proposal of an experimental model for the study of polycystic ovaries.

In view of the correlation of the circadian system with the estrous cycle in the rat, some investigators have proposed the induction of polycystic ovaries by exposing rats to continuous light. However, there is divergence with respect to time of exposure and light intensity. In the present paper we propose a simple and efficient experimental model for the study of polycystic ovarian physiopathology in rats. Twenty female Wistar rats weighing 200-220 g were initially submitted to a 14-h light/10-h dark cycle. Of the animals with regular estrous cycles, 9 were exposed to continuous light (600 lux) for 74 days (group 1) and 6 remained under the initial lighting conditions. A daily vaginal smear was used as indirect evidence for the changes in the estrous cycle. Plasma gonadotropin measurement and histological ovarian analysis showed that 90% of the animals in group 1 developed cystic follicles with the absence of the corpus luteum, despite the lack of reduction in ovarian weight commonly observed under 24-h lighting. This observation may be explained by the reduced time of stress to which the animals were submitted, since polycystic ovarian development occurred within less than 75 days of continuous exposure to 600-lux light, a time relatively shorter than commonly reported in the literature.

Animals↗
PubMed1990

[Antigenic expression in human choroid plexus carcinoma: report of 2 cases].

Primary neoplasms of choroid plexus are rare. Six morphological variants have been described: papillary, cystic, acinar, mucus-secreting, oncocytic, and anaplastic. The anaplastic variant, the so-called choroid plexus carcinoma, is the rarest of all and can metastasize. The differential diagnosis of the anaplastic variant of choroid plexus neoplasms with adenocarcinomas, melanomas and undifferentiated neoplasms can be troublesome chiefly in adults. The now large use of immunocytochemical techniques in tissue section has become a powerful tool in the analysis of cell lineages, tumoral and non-tumoral. Nevertheless, the choroid plexus neoplasms have shown a complex and a somewhat confusing pattern of antigenic expression. In two choroid plexus carcinomas (one localized in the right lateral ventricle from a boy of 1 year and 9 months old, and the other localized in the left lateral ventricle from a girl of 3 years old) the following antigens were searched (using the avidin-biotin-peroxidase complex): glial fibrillary acidic protein (GFAP) with monoclonal and polyclonal antibodies; cytokeratins of 40-50kDa, cytokeratins of 60-70kDA (callus cytokeratin), neuronal specific enolase (NSE) and S-100 protein with monoclonal antibodies. The two neoplasms showed immunoreactivity against NSE, S-100 protein and cytokeratin of 40-50kDA. The neoplasm of the boy exhibited glial differentiation having immunoreactivity against GFAP with monoclonal and polyclonal antibodies.

Antigens, Neoplasm↗
PubMedDate not supplied

Metacyclogenesis of Leishmania (Viannia) braziliensis in vitro: evidence that lentil lectin is a marker of complement resistance and enhanced infectivity.

Axenic culture in modified Grace's medium was used to induce metacyclogenesis of Leishmania (Viannia) braziliensis in vitro. Morphological characteristics, lectin agglutination profiles, susceptibility to complement lysis, and infectivity in vivo were compared between metacyclic promastigotes and promastigotes in mid-log phase growth. Short, arrow-like promastigotes and round, oval promastigotes were defined as putative metacyclic forms on the basis of being highly motile and free swimming, with a small cell body and long flagellum. These forms increased during metacyclogenesis to > 80% whereas long-bodied, slender promastigotes and intermediate slender promastigotes declined progressively. Lentil lectin selectively agglutinated L. braziliensis after the induction of metacyclogenesis, whereas concanavalin A, wheat germ agglutinin and peanut agglutinin similarly agglutinated metacyclic promastigotes and mid-log phase promastigotes. Metacyclic promastigotes survived in 7.5%-20% human serum whereas mid-log phase promastigotes did not. Five hundred metacyclic promastigotes were highly infective to hamsters whereas 500 mid-log phase promastigotes rarely caused any lesion. Specific agglutination by lentil lectin should allow purification of metacyclic organisms for standardization of immunoprotection and challenge experiments.

Agglutination↗
PubMedDate not supplied

Supercritical fluids are superior media for catalysis by cross-linked enzyme microcrystals of subtilisin Carlsberg.

We report on the performance of cross-linked enzyme microcrystals (CLECs) of subtilisin Carlsberg in supercritical fluids (SC-fluids). The catalytic activity of CLECs in SC-ethane was found to be 2- to 10-fold greater than in hexane under the same conditions, using CLECs dried by propanol washing. Air-dried CLECs and lyophilized powders showed much lower activities, reflecting the same hydration hysteresis effects as in organic solvents. Reaction rates were much lower in SC-CO(2), especially at higher water activity, probably as a result of acid-base effects of carbonic acid on the enzyme.

Catalysis↗