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Biomedical subjects

E S Lopes

Publications and source records attributed to E S Lopes.

At least 19 recordsLinked to original sources
PubMed1999

The rat prostatic epithelial cell line NRP-152 can differentiate in vivo in response to its stromal environment.

BACKGROUND: The clonally derived rat prostatic epithelial cell line NRP-152 was examined to determine its ability to differentiate in a tissue recombination model. METHODS: NRP-152 cells alone, or combined with urogenital mesenchyme (UGM) or 10T1/2 fibroblasts, were grafted beneath the renal capsule of athymic rodent hosts. After 1 and 3 months, grafts were examined grossly and immunohistochemically. RESULTS: NRP-152 cells grafted alone formed small (10-25 mg) grafts without recognizable architecture. NRP-152 cells recombined with UGM formed larger grafts (50-100 mg after 28 days) containing glandular epithelium. Columnar luminal cells expressed cytokeratins 8 and 18 and rat prostatic secretory markers (DP-1 and DP-2). The epithelial ducts were surrounded by well-differentiated smooth muscle. The glandular epithelial cells were shown to be of rat origin. NRP-152 + 10T1/2 tissue recombinants formed small grafts (10-40 mg wet weight) after 1 month. The epithelial component of these grafts formed solid unbranched cords expressing cytokeratins 5 and 14; no glandular epithelial structures were observed. The stromal matrix was densely packed with a few cells expressing alpha-actin. CONCLUSIONS: A clonally derived prostatic epithelial cell line can form structurally and functionally normal prostatic tissue. This suggests that prostatic basal and luminal epithelial cells can be derived from a common progenitor.

Animals↗
PubMed1997

Distribution of tonin- and kallikrein-like activities in rat brain.

Tonin- and kallikrein-like activities were investigated in different regions of the rat brain. The highest values of specific tonin activity, expressed as picomoles of angiotensin II liberated per minute per milligram of protein, were found in the neurohypophysis (359 +/- 190) and in the archicerebellum (200 +/- 68). The highest level of total tonin activity (picomoles of angiotensin II liberated per minute) was observed in the archicerebellum (902 +/- 308) which retained 97% of total tonin activity of whole cerebellum. Tonin activity was not detected in the cortex of cerebellum and in the choroid plexus. Low to intermediate values of specific (1.09 +/- 0.33 to 5.32 +/- 2.37) and total (1.38 +/- 0.55 to 93.00 +/- 49.30) tonin activity were observed in adenohypophysis, cerebellar nuclei, hypothalamus, thalamus, midbrain, pons, medulla and neurohypophysis. The lowest values of specific (0.11 +/- 0.05) and total (0.69 +/- 0.31) activities were observed in the hippocampus. Kallikrein-like activity was expressed as picomoles of p-nitroaniline liberated per minute per milligram of protein. No activity was detected in the neurohypophysis. For other regions, the values of the specific activity ranged between 72 +/- 18 and 282 +/- 14 except for the choroid plexus which was 5 +/- 2. The total kallikrein activity was also homogeneous ranging from 330 +/- 100 to 1870 +/- 112. For the choroid plexus and adenohypophysis the total kallikrein activity was 2.0 +/- 0.8 and 27 +/- 11, respectively.

Angiotensin II↗
PubMed1996

Initiation of secretory activity of rat prostatic epithelium in organ culture.

Functional differentiation of prostatic epithelium is manifested by the production of tissue specific secretory proteins. In vivo production of these proteins is dependent on the presence of serum androgens. A serum-free organ culture system was used to examine the initiation of prostatic epithelial cytodifferentiation in vitro using two rat prostate specific secretory proteins (DP-1 and probasin) as markers of epithelial cytodifferentiation. The dorsal-lateral and anterior prostatic (AP) lobes from 12-day-old rats were cultured for 6 days in serum-free medium in the presence or absence of androgens. At the start of culture, secretory proteins DP-1 and probasin were undetectable using Western blot analysis. DP-1 and probasin were produced by explants cultured in the presence of androgens but were not detected in the absence of androgens. Dose-response studies were carried out for testosterone (T), 5 alpha-dihydrotestosterone (DHT), 5 alpha-Androstan-3 alpha, 17 beta-diol (3 alpha-Adiol), and two synthetic androgens: 17 alpha-methyl-19-nortestosterone (MENT) and methyltrienolone (R1881). All androgens used were capable of inducing expression of DP-1 and probasin in vitro. T, R1881, and Ment were effective at doses of 10(-7) M to 10(-9) M, whereas both DHT and 3 alpha-Adiol were able to induce DP-1 and probasin at concentrations as low as 10(-10) M. Estrogen (17 beta-Estradiol), hydrocortisone (11 beta, 17 alpha, 21-trihydroxypregn-4-ene-3, 20-dione), and progesterone (4-pregnen-3, 20-Dione) were ineffective in inducing prostatic secretory activity. Hydroxyflutamide (alpha-alpha-alpha-trifluro-2-methyl-4'-nitro-m-lactoluidide ) blocked the induction of secretory activity elicited by T. From histological sections, it was observed that explants cultured with T exhibited tall columnar epithelial morphology with organized stromal components. Tissue sections of explants cultured without T exhibited a cuboidal to low columnar morphology with less organized stromal components when compared with glands cultured with T. A DNA synthetic index was established to measure proliferation in the explants at the end of the culture period. Explants cultured in the presence of T exhibited greater DNA synthetic activity than explants cultured in the absence of T (P < 0.05). Using this serum-free model, we can explore the mechanism for the initiation of secretory cytodifferentiation.

Androgen-Binding Protein↗
PubMed1996

[Prevalence of dental caries in children from 0 to 6 years old attending nursery: the influence of socioeconomic factors].

Oral health condition in samples of children from zero to six years old, examined in day nurseries for children from Bauru and S. Paulo County (Brazil) by the caries indicator in primary dentition-dmfs, is assessed. The first group did not receive oral health care where any as the second group received the standard oral care provided by the institution. Variables related to way of life and their relationship to the presence of caries were evaluated. Multiple regression analysis showed a statistically significant association of age and frequency of dental visits with the prevalence of dental caries (p < 0.05). The data also showed that 23.3% of the children from Bauru, and 9.3% of those from S. Paulo were free of caries, numbers that are very far from the 50% proposed by WHO for the year 2000. The overall prevalence of dental caries was greater for the Bauru group than for the S. Paulo group; however, statistical significance was only found in the 3-4 age-group (p < 0.05). Sex differences in the occurrence of dental caries were not statistically significant.

Brazil↗
PubMed1992

A nontoxic derivative of Bothrops jararaca venom suitable to generate antibodies against the native venom.

Bothrops jararaca venom was toxoided by stepwise iodination with cold iodine, and doses up to 30 LD50 were non-lethal by i.p. route (BICALHO et al., 1990). Groups of mice injected chronically with the native, or the iodinated venom, have been subjected to histological examination. In the native group, in the spleen, around the white pulp, an acellular, amorphous eosinophilic substance, metachromatic to Methyl Violet, PAS positive, and dichroic to Congo Red under polarized light, was present. Strong congestion in the liver, kidneys and lungs was found. The salivary glands were replenished with an amorphous substance in the serosal acini. The groups injected with the iodinated venom only show discrete alterations, more akin to the control group. The anavenin was immunogenic. Antibody generation in mice and rabbits was detected by ELISA. In mice, active protection against challenge with native venom was presented. The iodinated venom generated a rabbit antiserum with strong lines in gel immunoprecipitation against the lethal venom. A minimum neutralization titer of 2.3 mg ml-1 against the native venom was attained in the first cycle (28 days) of immunization. After 3 cycles (100 days), the protection rose to 5.1 mg ml-1.

Animals↗
PubMed1990

Clinical evaluation of Dycal under amalgam restorations.

Sixty-eight clinical amalgam restorations were removed to examine the consistency of the calcium hydroxide bases. The variation of the base consistency was influenced by the age and/or clinical profile of teeth and the status of the restorations. The clinical conditions affected the calcium hydroxide base consistency.

Calcium Hydroxide↗
PubMed1985

Comparison of dental prophylaxis and toothbrushing prior to topical APF applications.

This study was conducted to evaluate the effect of dental prophylaxis prior to the topical application of acidulated phosphate fluoride solution applied twice a year in schoolchildren. Experimental groups were: Group I--control group, had no treatment. Group II--twice yearly topical application of acidulated phosphate fluoride solution with prior professional prophylaxis with rubber cup and non fluoride paste. Group III--twice yearly topical application of acidulated phosphate fluoride solution with prior toothbrushing with a non-fluoridated prophy paste. After 18 months analysis of 160 children in each study group led to the following conclusions: 1. Acidulated phosphate fluoride topical applications are effective in the prevention of dental caries. 2. The omission of a professional prophylaxis prior to topical fluoride application does not affect significantly the caries preventive effect.

Acidulated Phosphate Fluoride↗
PubMed1979

The accuracy of soldering investment.

Testing soldering investments of different thermal expansions established that an acceptable dimensional change in a three-unit fixed partial denture occurs with an investment which expands at 0.70% to 0.72%.

Dental Alloys↗
PubMed1978

Influence of axiopulpal line angle and proximal retention on fracture strength of amalgam restorations.

Proximal retentive grooves significantly increase the strength of amalgam restorations in Class II cavities. There were no remarkable differences that could have clinical significance between sharp or rounded axiopulpal line angles and rounded or rounded and sloped pulpal walls. Chromium-cobalt dies are effective for tests of fracture strength of amalgam restorations.

Chromium Alloys↗