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Biomedical subjects

A Dupont

Publications and source records attributed to A Dupont.

At least 73 records · Page 4Linked to original sources
PubMed1989

Steroid and gonadotropin hormone levels in young African women with filarial infection.

Serum levels of dehydroepiandrosterone sulfate (DHEAS), testosterone (T), progesterone (P), estradiol (E2), prolactin (PRL), cortisol (F) and gonadotropins (FSH, LH) were analysed by radioimmunoassay for 125 schoolgirls aged 14-16, in a zone of endemic filariasis 3 days after menses. Two groups were identified: the infected group in which 38 subjects had circulating Loa loa and or Mansonella perstans microfilariae as determined by the Knott's concentration technique, and the non-infected group (87 subjects without microfilaremia). All results are expressed as the mean +/- SD. No significant difference was found between the two groups for age (14.47 +/- 1.37 yr vs 14.50 +/- 1.37 yr) or for body wt (46.10 +/- 8.45 kg vs 47.06 +/- 8.26 kg). There was a tendency to lower levels of DHEAS in the infected group by comparison with controls (54.92 +/- 37.34 micrograms/dl vs 66.80 +/- 47.18 micrograms/dl) while in the same infected group more subjects had higher levels of prolactin by comparison with the control group (10.85 +/- 14.16 ng/ml vs 9.80 +/- 5.56 ng/ml). Testosterone, progesterone, estradiol levels and the LH/FSH ratio were lower in the infected group than in the non-infected group (P: 0.25 +/- 0.12 ng/ml vs 0.33 +/- 0.20 ng/ml, P less than 0.025; T: 0.55 +/- 0.17 ng/ml vs 0.62 +/- 0.19 ng/ml, P less than 0.05; E2: 32.95 +/- 19.63 pg/ml vs 66.98 +/- 54.83 pg/ml, P less than 0.001; LH/FSH: 0.91 +/- 0.44 vs 1.30 +/- 0.84, P less than 0.005) respectively. No significant difference was found between the two groups for F; however FSH levels correlated negatively with F levels only in the microfilaremia group (r = -0.38, n = 38, P less than 0.05). Our results suggest that the presence of microfilaremia in our subjects may have contributed to reduced steroid levels, perhaps by involvement of the cyclic AMP kinase system. These observations may explain the delayed menarche and androgen secretion found during puberty in a similar population living in the same zone of endemic filariasis. Microfilaremia should therefore be considered an environmental factor which mediates endocrine disorders in subjects living in tropical filariasis areas.

Adolescent↗
PubMed1989

Influence of diet on plasma steroids and sex hormone-binding globulin levels in adult men.

Several experimental studies have suggested that diet can alter the production and metabolism of steroids in men. The purpose of this study was to determine the levels of unconjugated steroids and steroid glucuronides as well as sex hormone-binding globulin (SHBG) among normal adult men who were either omnivorous or vegetarians. The participants were white volunteers ranging from 25-35 years of age and the blood samples were taken between 0900 h and 1000 h and between 1600 h and 1700 h for two consecutive days. No significant statistical change was found in plasma dehydroepiandrosterone, dehydroepiandrosterone sulfate, testosterone, dihydrotestosterone and estradiol levels. Vegetarian group showed a higher levels of sex hormone-binding globulin (SHBG) while the free androgen index (FAI; calculated by the ratio testosterone/SHBG) was lower in this group. Although the concentrations of androsterone glucuronide were higher in vegetarian group, the vegetarians had a 25-50% lower level of androstane-3 alpha, 17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide. Our data further indicate that both, androstane-3 alpha,17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide concentrations are significantly correlated with SHBG levels and with the FAI values. The increases in androstane-3 alpha,17 beta-diol glucuronide and androstane-3 beta,17 beta-diol glucuronide levels in the omnivorous group are probably a consequence of the elevation of the FAI. Our data suggest that in a vegetarian group, less testosterone is available for androgenic action.

Adult↗
PubMed1989

Combination therapy with castration and flutamide: today's treatment of choice for prostate cancer.

In order to achieve a more complete blockade of androgens of both testicular and adrenal origins, 223 patients with advanced prostate cancer (stage D2 with bone metastases) received the combination therapy with the antiandrogen Flutamide and the LH-RH agonist [D-Trp6,des-Gly-HN10(2)] LH-RH ethylamide as first treatment. As assessed by the objective criteria of the US NPCP, a positive response was obtained in 94% of patients, thus leaving only 6% of patients with no response at the start of treatment while, following standard therapy, 20-40% of patients do not respond to treatment. The duration of response was increased while longer survival (an advantage of approximately 14 months compared to standard therapy, 38.5 vs approximately 24 months) was achieved with no or minimal side effects. Highly positive results were also obtained using the combination therapy in stage C prostate cancer patients while temporary treatment with the combination therapy in stages A and B prostate cancer facilitated radical prostatectomy. The present data supported by the results of independent studies indicate that combination therapy should be the treatment for all patients with advanced disease and possibly also at earlier stages of prostate cancer in combination with surgery.

Anilides↗
PubMed1989

Comparison of residual C-19 steroids in plasma and prostatic tissue of human, rat and guinea pig after castration: unique importance of extratesticular androgens in men.

The concentrations of dehydroepiandrosterone (DHEA), its sulfate (DHEAS), androstenedione (A-dione), testosterone (T) and dihydrotestosterone (DHT) have been measured before and after castration in men and two animal models, namely the rat and the guinea pig. In adult men, the pre-castration levels of plasma DHEAS and DHEA were measured at 1839 +/- 320 and 2.4 +/- 0.5 ng/ml, respectively, while in both animal models, the concentrations of these two steroids were below 0.3 ng/ml. Orchiectomy in men reduced plasma T and DHT levels from 2.9 +/- 0.1 and 0.60 +/- 0.10 to 0.42 +/- 0.21 and 0.05 +/- 0.01 ng/ml (P less than 0.01), respectively, while there was no significant effect observed on DHEAS, DHEA and A-dione levels. By contrast, castration in the rat reduced the low levels of circulating DHEA and A-dione below the detection of the radioimmunoassay (RIA) used. In castrated guinea pig, a small quantity of plasma A-dione (0.07 +/- 0.02 ng/ml) was measured while DHEA was undetectable. Moreover, in the rat and guinea pig, plasma T and DHT levels became undetectable. Following administration of the antiandrogen Flutamide for two weeks in the castrated rat and guinea pig, prostate weight was not further reduced, thus indicating that there is no significant androgenic activity left following castration of these two species. In fact, castration in the rat and guinea pig caused a decrease in prostatic levels of DHT from 4.24 +/- 0.351 and 9.42 +/- 1.43 ng/g, respectively, to undetectable levels. In men, on the other hand, the prostatic DHT levels were only inhibited from 5.24 +/- 0.59 to 2.70 +/- 1.50 ng/g, respectively. As expected, when Flutamide was administered to the rat and the guinea pig, the levels of prostatic steroids remained undetectable while, in men, the DHT content in the prostate was further reduced to undetectable values. In summary, the plasma levels of DHEAS, DHEA, delta 4-dione are markedly different between men and both animal models used and furthermore, measurements of prostatic levels of androgens suggest that the high plasma levels of these steroids are likely responsible for the presence of important amounts of DHT in human prostate after castration.

Aged↗
PubMed1989

Interpretation of antibodies reacting solely with human retroviral core proteins in western equatorial Africa.

Out of 4176 sera from asymptomatic adults originating from Chad, equatorial Guinea and Gabon tested for HIV-1 antibodies, 146 (3.5%) were positive by an enzyme immunoassay (EIA). By Western blot (WB), 20 (0.5%) were positive, i.e. with antibodies to the core and the envelope proteins, 96 (2.3%) were indeterminate, i.e. with antibodies to the viral core proteins only and 30 (0.7%) were negative. On testing for HIV-2 by WB, two of the 96 indeterminate sera had antibodies to the HIV-2 envelope glycoproteins. Two complementary tests were used: a radioimmunoprecipitation assay (RIPA) and a HIV EIA recombinant assay (ENVACOR) to check 53 of these indeterminate sera. Forty-one were positive for the p25 protein in RIPA, of which 34 were negative in ENVACOR; six were positive for core proteins only and one was positive for envelope and core proteins using this assay. Twelve of the 53 indeterminate sera were negative in RIPA, of which 11 were negative and one positive for core proteins in ENVACOR. Thus, 42 of these sera remained indeterminate even after the two additional tests which did not allow a distinction between retroviral infection or non-specific reactions. We were able to isolate an unusual HIV-1 virus from lymphocyte cultures of two subjects presenting antibodies directed only against the core proteins.

Africa, Western↗
PubMed1989

Anti-hormone treatment for prostate cancer relapsing after treatment with flutamide and castration. Addition of aminoglutethimide and low dose hydrocortisone to combination therapy.

The effect of further adrenal androgen blockade with aminoglutethimide (AG) plus low dose hydrocortisone (HC) was studied in 119 patients with clinical stage D2 prostate cancer who previously progressed after standard hormone therapy and were under progression while receiving the combination therapy with Flutamide and castration. Using the objective criteria of the US NPCP, 1 complete, 2 partial and 14 stable responses were obtained for a total response rate of 14.3%, while 102 patients continued to progress. The 50% probability of survival was 21.0 months for the responders and 9.2 months for the non-responders. The present data indicate that further androgen blockade with AG + low dose HC is well tolerated and can be of benefit to a significant proportion of patients in progression at a very late stage of the disease.

Aminoglutethimide↗
PubMed1989

Transmission of syphilis between sexual partners in Gabon.

The prevalence and transmission of syphilis was studied in a semirural community in south eastern Gabon. The overall prevalence was 8% (99/1251) and there was no difference in age adjusted prevalence between men and women. The transmission of syphilis between sexual partners occurred in 18.1% (8/44).

Adolescent↗
PubMed1989

Differential recognition of Loa loa antigens by sera of human subjects from a loiasis endemic zone.

Somatic antigens of Loa loa adult worms with molecular weights of 15-180 kDa were identified by Western blot analysis using sera from 3 categories of parasitologically and clinically defined subjects from a loiasis endemic zone. Sera of occult, amicrofilaremic (OL), and 'resistant' individuals with no clinical signs of infection (R) reacted with an antigen of 160 kDa; sera of highly microfilaremic individuals (ML) did not. ML sera strongly reacted with an antigen of 18 kDa which was recognized only weakly or not at all by OL and R sera. At higher dilutions, OL sera only reacted with antigens at 23 and 160 kDa and ML sera reacted with antigens at 18 and 23 kDa, whereas R sera reacted with antigens at 23, 42, 54, 70, 100, and 160 kDa. These data suggested that R sera contained a higher concentration of antibodies which reacted with denatured, nitrocellulose-bound antigens. The IgG4 isotype predominated for all groups of sera, while IgG3 antibody responses were observed only with R sera. IgG1 antibodies were seen in all groups but reacted with fewer antigens than IgG4 antibodies, and no IgG2 antibody responses were detected. Sera against Brugia malayi, Wuchereria bancrofti, Onchocerca volvulus, and Dirofilaria immitis cross-reacted with somatic antigens greater than 70 kDa, whereas none reacted with Loa loa antigens less than 23 kDa.

Animals↗
PubMed1989

[Intravascular malignant lymphoma (malignant angioendotheliomatosis). Apropos of a case with histologic, immunohistochemical and ultrastructural studies].

We report a new case of intravascular malignant lymphoma that arose in an 81-year-old woman. The most prominent symptoms were impressive dermatologic anomalies including painful, diffuse edema over which arborescent telengiectasic lesions could be seen. This clinical picture was associated with the presence, in deep skin biopsy specimens, of mononucleate tumor cells located within the lumen of dermal vessels. Complementary immunohistochemical and ultrastructural studies confirmed that the intravascular tumor growth was lymphomatous in nature. Clinical manifestations of this disease are recalled, and histopathologic features as well as the characteristic location of this malignant lymphoma are analyzed and discussed. Thus, we agree with Félix [3] and Witschi [6] that the cords of cells that will give rise to the follicular cells surrounding the ovocytes originate only from the coelomic epithelium; the primary mesenchyma forms the cortical stroma, and this embryonic type tissue, characterized by enourmous physiologic plasticity, differentiates into endocrine tissue to form the inner theca. the mesonephros plays no part whatsoever in the formation of the ovary.

Aged↗
PubMed1989

Seroepidemiological survey of HTLV-I infection among randomized populations of western central African countries.

Between 1987 and 1988, a survey to determine the distribution of HTLV-I infection was conducted in a representative population of adults, living in southern Chad, Cameroon, and Equatorial Guinea. Populations studied were selected by the cluster sampling technique. Sera were tested for IgG antibodies to HTLV-I by ELISA. ELISA-positive sera were retested by Western blot. The study comprised 2,301 adults, all apparently healthy. Crude prevalence rates range from 0.5 to 11.8%. We found three clearly different areas of HTLV-I seroprevalence rates. An area of low seropositivity in southern Chad and northern Cameroon (0.5-2.0%), an area of moderate seropositivity in the savannah region of Ngaoundere, Cameroon (4.2%) and in Bata, Equatorial Guinea (6.5%), and lastly an area of high seropositivity (8.6-11.8%) in the equatorial forest area of Equatorial Guinea and southern Cameroon. HTLV-I seroprevalence rates increased with age up to 12.6% after 40 years old in the areas of high seropositivity. There was no difference between male and female age-adjusted prevalence rates in all of the areas studied.

Adolescent↗
PubMed1989

Hepatitis B and delta infection in Gabon: a seriological survey in a representative sample of the province of Haut-Ogooue.

Hepatitis B virus markers and antibodies to delta agent were studied in adult people (15-54 years) in the province of Haut-Ogooue (Gabon), randomly selected by cluster sampling technique. Of the 384 people, 37 (9.6%) were positive for HBsAg, of which 23 (62.2%) were positive for HBeAg; 246 (65.3%) had anti-HBs and 53 (13.8%) had anti-HBc as the only marker. Chronic carriage of HBV defined as presence of HBsAg or exclusive anti-HBc was observed in 90 people (32%). At least one of the HBV markers was found in 89% of the people. Women were more frequently positive than men. No difference in relation to age was observed. Anti-delta was found in 12 (3.5%) of the 341 people with HBV markers and 7/12 of these could be considered as chronic HBV carriers.

Adolescent↗
PubMed1989

Seroprevalence of treponemal infection in rural and semi-rural communities in south-eastern Gabon.

A sero-epidemiological study on the prevalence of treponemal infection was performed in a representative sample of adult women in rural and semi-rural communities in south-eastern Gabon. The overall prevalence of treponemal infection was 10.1% and 9.2% in the group of pregnant women. Age-adjusted prevalence rates were significantly lower in the rural than in semi-rural area, 7.7% and 12.2% respectively (p less than 0.05). This was due to the significantly lower syphilis prevalence in the age group 15-29 years in the rural area. There was no statistically difference in age-adjusted prevalence rates in women with different fertility status or pregnancy outcome.

Adolescent↗
PubMed1988

Epidemiology of HTLV-I in Gabon (Western Equatorial Africa).

In 1986 a survey to determine the distribution of HTLV-I infection was conducted in Gabon in a representative sample of adults and children. Five samples were taken in adults and 2 samples in children living in urban and rural areas. Samples were taken by the cluster sampling technique, i.e., clusters of randomly selected households. Sera were tested for IgG antibodies to HTLV-I by ELISA. ELISA-positive sera were retested by Western blot. The study comprised 1,874 adults and 684 children, all apparently healthy. In the adults the crude prevalence rates of anti-HTLV-I antibodies ranged from 5.0% in urban areas to 10.5% in the southern province. In rural areas, the age-adjusted prevalence rate (9.1%) was significantly higher than in urban areas (5.0%) (p less than 0.01). In children there was no significant difference between urban (2.4%) and rural (2.0%) prevalence rates. Prevalence increased with age but was not related to sex. This survey shows that HTLV-I infection is common in Gabon but varies considerably by region.

Adolescent↗
PubMed1988

Identification of a surface antigen on Loa loa microfilariae the recognition of which correlates with the amicrofilaremic state in man.

Filarial infections induce a spectrum of disease in their natural hosts, and by correlating immunity found in individuals with their disease pattern, one may delineate non-pathogenic, protective mechanisms. Loa loa is causal of mild to moderate pathology, and it is unique among the human filaria in that adult worms are occasionally visible during subconjunctival migration. To study immune mechanisms controlling microfilaremia, sera from 15 subjects with amicrofilaremic occult loiasis (OL) were compared with sera from 10 subjects with microfilaremic loiasis (ML) microfilaremia, (greater than 4000/ml) for their reactions with living microfilariae (mf). An IFA was first used to detect antibodies able to bind to the surface of living L. loa mf. ML subjects either did not react (7/10) or reacted only very weakly (3/10). Highly reactive sera were found only in OL subjects; 7/15 gave very bright fluorescence, 5/15 gave moderate reactions, and 3/15 were negative. Most of these antibodies were of the IgG class. Sera from all subjects were also reacted with living mf in an antibody-dependent cellular adherence test using normal leukocytes. Sera that were strongly positive in IFA showed strong adherence and IFA-negative sera were non-reactive. To identify the Ag involved, mf were surface iodinated, detergent-extracted Ag were immunoprecipitated, and Mr was determined on SDS-PAGE. Several OL sera, all highly reactive in the above tests, precipitated a 23-kDa molecule with which all ML sea failed to react. Sera from a mandrill experimentally infected with L. loa also precipitated the 23-kDa Ag when taken post-patency. In conclusion, it appears that certain people who control L. loa microfilaremia have high levels of IgG antibodies that bind to a surface Ag of 23 kDa and are able to mediate cellular adherence.

Adhesiveness↗
PubMed1988

Plasma levels of hydroxy-flutamide in patients with prostatic cancer receiving the combined hormonal therapy: an LHRH agonist and flutamide.

The present study describes a method for the measurement of the plasma levels of hydroxy-flutamide (Flu-OH), the biologically active and main circulating metabolite of flutamide. We have observed that two to four hours after oral administration of 250 mg of flutamide to healthy young men, as well as to patients with prostate cancer, the plasma concentration of Flu-OH reaches a peak at approximately 1.7 microM. The plasma concentration of Flu-OH measured at months 6, 12, and 18 of treatment shows a minimal basal level of 3.4 microM with a maximal increase at 6.8 to 8.5 microM at 2 to 4 hours. Since the serum levels of testosterone in these patients are approximately 1 nM, the levels of the active antiandrogen are at a 5000- to 10000-fold excess. However, due to the low affinity of the antiandrogen for the androgen receptor, it is extremely important to maintain this concentration of the antiandrogen in plasma constant.

Adult↗