Biomedical subjects

M C Romano

Publications and source records attributed to M C Romano.

At least 19 recordsLinked to original sources

PubMed2006

Metabolism of steroid hormones by Taenia solium and Taenia crassiceps cysticerci.

Previous in vitro experiments showed that both, Taenia crassiceps and Taenia solium cysticerci have the ability to metabolize exogenous androstenedione to testosterone. Here we evaluate on the capacity of both cysticerci to synthesize several sex steroid hormones, using different hormonal precursors. Experiments using thin layer chromatography (TLC) showed that both cysticerci were able to produce (3)H-hydroxyprogesterone, (3)H-androstenedione and (3)H-testosterone when (3)H-progesterone was used as the precursor. They also synthesized (3)H-androstenediol and (3)H-testosterone when (3)H-dehydroepiandrosterone was the precursor. In addition, both cysticerci interconverted (3)H-estradiol and (3)H-estrone. These results, strongly suggest the presence and activity of the Delta4 and Delta5 steroid pathway enzymes, 3beta-hydroxysteroid dehydrogenase/Delta(5-4) isomerase-like enzyme (3beta-HSD), that converts androstenediol into testosterone; and the 17beta-hydroxysteroid dehydrogenase that interconverts estradiol and estrone, in both types of cysticerci.

Androgens↗

PubMed2006

Taenia solium cysticerci synthesize androgens and estrogens in vitro.

Cysticerci from Taenia solium develop in the pig muscle and cause severe diseases in humans. Here we report on the capacity of T. solium cysticerci to synthesize sex steroid hormones. T. solium cysticerci were dissected from infected pork meat. Parasites were incubated for different periods in culture media plus antibiotics and tritiated steroid precursors. Blanks and parasite culture media were extracted and analyzed by thin-layer chromatography (TLC) in two different solvent systems. In some experiments, the scoleces were incubated separately. Results showed that T. solium cysticerci transform [(3)H]androstenedione to [(3)H]testosterone in a time-dependent manner. The production was confirmed in two different solvent systems. The incubation with [(3)H]testosterone yielded only small amounts of [(3)H]androstenedione. The recrystallization procedure further demonstrated that the metabolite identified by TLC was testosterone. The isolated scoleces incubated in the presence of [(3)H]androstenedione yielded [(3)H]testosterone and small quantities of [(3)H]17beta-estradiol. The results reported here demonstrate that T. solium cysticerci have the capacity to synthesize steroid hormones.

Androgens↗

PubMed2006

Insulin stimulates proliferation but not 17beta-estradiol production in cultured chick embryo ovarian cells.

The development of the chick embryo gonads is influenced by gonadotropins [follicle-stimulating hormone (FSH), luteinizing hormone, human chorionic gonadotropin (hCG)]. We have previously shown that insulin enhanced the production of androgens in the testis of the newly hatched chicken and increased the proliferation of chick embryo testis cells. In the present paper, we have studied the effect of insulin on embryonic chick embryo ovarian cells and compared them with those of human FSH and hCG. The ovaries of 18-d-old chick embryos were dissociated and cultured for different periods in Dulbecco's modified Eagle's medium in the presence and absence of insulin, human FSH, hCG, and combinations of them. 3H-thymidine incorporation was used as an indicator of cell proliferation; steroids were measured by radioimmunoassay. Results showed that insulin enhanced the proliferation of ovarian cells in a dose- and time-dependent manner. Gonadotropins did not affect significantly the ovarian cell proliferation. Insulin did not change 17beta-estradiol production. The combination of insulin and FSH or insulin and hCG decreased the stimulation of estrogen secretion caused by the addition of the gonadotropins. In some experiments, ovarian cells were cultured with or without insulin, and subpopulations were identified. The results showed that insulin but not human FSH or hCG increased the proliferation of germinal cells after 60 h in culture. Insulin and human FSH did stimulate the other 2 subpopulations. In summary, present results suggest that insulin is an important hormone in the development of the chick embryo ovary.

Animals↗

PubMed2005

Differentiation of normal and cancer cells induced by sulfhydryl reduction: biochemical and molecular mechanisms.

We examined the morphological, biochemical and molecular outcome of a nonspecific sulfhydryl reduction in cells, obtained by supplementation of N-acetyl-L-cysteine (NAC) in a 0.1-10 mM concentration range. In human normal primary keratinocytes and in colon and ovary carcinoma cells we obtained evidences for: (i) a dose-dependent inhibition of proliferation without toxicity or apoptosis; (ii) a transition from a proliferative mesenchymal morphology to cell-specific differentiated structures; (iii) a noticeable increase in cell-cell and cell-substratum junctions; (iv) a relocation of the oncogenic beta-catenin at the cell-cell junctions; (v) inhibition of microtubules aggregation; (vi) upregulation of differentiation-related genes including p53, heat shock protein 27 gene, N-myc downstream-regulated gene 1, E-cadherin, and downregulation of cyclooxygenase-2; (vii) inhibition of c-Src tyrosine kinase. In conclusion, a thiol reduction devoid of toxicity as that operated by NAC apparently leads to terminal differentiation of normal and cancer cells through a pleiade of converging mechanisms, many of which are targets of the recently developed differentiation therapy.

Acetylcysteine↗

PubMed2004

Estimation of dynamical invariants without embedding by recurrence plots.

In this paper we show that two dynamical invariants, the second order Renyi entropy and the correlation dimension, can be estimated from recurrence plots (RPs) with arbitrary embedding dimension and delay. This fact is interesting as these quantities are even invariant if no embedding is used. This is an important advantage of RPs compared to other techniques of nonlinear data analysis. These estimates for the correlation dimension and entropy are robust and, moreover, can be obtained at a low numerical cost. We exemplify our results for the Rossler system, the funnel attractor and the Mackey-Glass system. In the last part of the paper we estimate dynamical invariants for data from some fluid dynamical experiments and confirm previous evidence for low dimensional chaos in this experimental system.

Journal Article↗

PubMed2004

Proliferative and steroidogenic effects of follicle-stimulating hormone on cultured chick embryo testis cells.

The present study evaluated the follicle-stimulating hormone (FSH) effect on cell proliferation and steroid production by chick embryo testis. Dissociated cells from 18-d-old embryos were cultured on polycarbonate membranes in defined media. In some experiments, cells were further separated by a metrizamide gradient, and 5 cellular subpopulations were recovered and cultured. [3H]thymidine was added to the culture media. When necessary, 17beta-estradiol, human FSH (hFSH), recombinant human FSH (rhFSH), or human chorionic gonadotropin (hCG) was added to the medium at the beginning of the culture. The total number of cells and the incorporation of [3H]thymidine increased when hFSH or rhFSH was added. No changes were produced by the addition of hCG or 17beta-estradiol. The dose-response curve to hFSH resulted in an ED50 of 0.25 IU/mL. The stimulatory effect of hFSH on total number of cells and on [3H]thymidine incorporation was significant at 36 h of culture and was maintained up to 60 h. Testosterone production increased with the addition of FSH or rhFSH, meanwhile estradiol production was below the limit of detection of RIA. The hFSH proliferative effect measured as [3H]thymidine incorporation was observed only in the F3, F4, and F5 fractions of the density gradient. Present results show that hFSH and rhFSH, but not hCG or estradiol, stimulate testis cell proliferation in a time- and dose-dependent manner. The combination of [3H]thymidine incorporation and testosterone production in fractions obtained from the metrizamide density gradients suggests that the cell fractions of the chick embryo testis show a differential response to FSH.

Animals↗

PubMed2003

[The individual reception project (IRP) for anaphylactic emergencies. The situation in France and French overseas territories in 2002].

INTRODUCTION: The management in schools of children with life-threatening or chronic diseases has led to the development of Individual Reception Projects (IRP) since 1993, notified in the state education ministry's circular letter. The aim of this study was to assess the status of such IRPs in France and the French Overseas Territories in the management of food allergy risks. METHOD: The regional departments of educational promotion were contacted and the survey was run between May and June, 2002. The items of the questionnaire were: the number of IRPs for anaphylactic emergencies, details on the allergies themselves, an overview of the eventual existence of dialogue structures among school physicians, heads of schools, allergists, treatment prescribers and emergency protocols. RESULTS: The total survey revealed 7482 IRP for anaphylactic reactions to food (14% of the total IRPs). The frequency of IRPs varied greatly depending on the regions. The Paris area represented 36.3% of the total. The Lorraine area: 5.6%, the Haute-Garonne: 5%, and the Bouches-du-Rhône: 3.3%. The IRPs represented 0.002 (Ardèche) to 0.33% (Alpes-de-Haute-Provence) of the school attending population. The mean level was of 0.065%; 71.6% of the IRPs concerned the 1st grade (1 IRP for 1091 children). In decreasing frequency, the allergens concerned were: peanuts, eggs, dried nuts, fish, dried peas and milk. Dialogue structures were established in 38 regions. DISCUSSION: The IRPs have increased 4-fold since the circular letter in 1999. The enhanced prevalence of numerous (new) allergies to dried nuts and leguminous plants has been emphasized, and peanut allergies have been confirmed. The complexity of managing the IRPs and need for information and training of state education and municipal staff requires the further development of dialogue structures, which are still clearly insufficient.

Adolescent↗

PubMed2003

Steroid hormone production by parasites: the case of Taenia crassiceps and Taenia solium cysticerci.

Many examples of reciprocal endocrine interactions between parasites and hosts have been found in insects, arthropods and mammals. Cysticercosis produced by Taenia solium metacestodes is a widely distributed parasite infection that affects the human and the pig. Taenia crassiceps experimental murine cysticercosis has been used to explore the role of biological factors involved in host-parasite interactions. We had shown that T. crassiceps cysticercosis affects the serum concentration of steroid hormones and the reproduction behavior of the male mice host. In an effort to understand the biology of the parasite, we had investigated the parasite capacity to produce sex steroids. For this purpose, T. crassiceps cysticerci were incubated in the presence of different steroid precursors. TLC and recrystallization procedures showed that testosterone is produced from 3H-androstenedione in cysticerci. The conversion of 3H-testosterone to androstenedione, although present is much less significant. In addition, we had studied the production of testosterone by T. solium cysticerci. For this purpose, cysticerci were dissected from pork meat and incubated as above described. The results showed that T. solium cysticerci also produce testosterone. We have speculated about the importance of androgens in the growth of T. crassiceps cysticerci and found that the addition of the antiandrogen flutamide to the culture media of the parasites significantly decreased 3H-thymidine incorporation. We therefore hypothesized, that the ability of cysticerci to produce testosterone from steroid precursors might be important for the parasite growth and development.

Androgens↗

PubMed2003

Healthy worker effect and changes in respiratory symptoms and lung function in hairdressing apprentices.

AIMS: To compare the prevalence and incidence of respiratory symptoms and lung function values between hairdressing apprentices and office apprentices. METHODS: A total of 322 hairdressing apprentices and 277 office apprentices (controls) were studied. Two cross sectional surveys were conducted in 1994 and 1996/97 with longitudinal follow up for a subgroup of apprentices (191 hairdressing apprentices and 189 office apprentices). RESULTS: In the initial phase, the prevalence of respiratory symptoms was significantly lower among hairdressing apprentices than among office apprentices. Lung function test results showed significantly higher values for hairdressing apprentices. Non-specific bronchial reactivity was similar in the two groups. In the final phase, results for respiratory symptoms were similar. The incidence of respiratory symptoms was not significantly different between hairdressing apprentices and office apprentices. Subjects who dropped out had lower values for FVC and FEV1 in the initial phase than those who completed the final phase. There was a significant deterioration of FEV1 and FEF25-75% in hairdressing apprentices compared to office apprentices. There was a link between atopy and the incidence of most of the respiratory symptoms (day/night cough, wheezing, dyspnoea, mucosal hyperresponsiveness) and between smoking and the incidence of bronchial hyperreactivity. There was no significant correlation between change in lung function tests and specific hairdressing activities reported at the end of the apprenticeship or with environmental working conditions in hairdressing salons. CONCLUSIONS: Although a healthy worker effect can be suspected, results showed a significant deterioration of baseline values of lung function tests in the hairdressing apprentice group. However, no clear link was shown between change in lung function tests and specific parameters of occupational activities.

Adolescent↗

PubMed2003

[The Individualized Welcome Project and its adaptation to the food allergy field].

Allergy to food in childhood becomes today a real public health problem. Setting up some "Projets d'accueil Individualisés" (i.e. a management project at school for each allergic patient) has allowed to protect the high risk pupils in the best way since 1999. Allergy adapted meals are proposed and emergency treatments they need are organized. In this field, net working seems to be essential more than everywhere else.

Adolescent↗

PubMed2002

Inhibition of p-450 aromatase prevents feminisation and induces protection during cysticercosis.

Cysticercotic male mice undergo an impressive feminisation process, characterised by 200 times increased serum 17beta-estradiol levels while testosterone and dihydrotestosterone are 90% reduced, which results in elevated parasite burden. Administration of Fadrozole (an aromatase inhibitor) in male and female mice suppressed the production of 17beta-estradiol, accompanied with a 70% reduction in parasite burden. This protective effect was associated in male mice with a recovery of the specific cellular immune response. Interleukin-6 (IL-6) serum levels, and its production by splenocytes, was augmented by 80%, together with a 10-fold increase in its expression in testes of infected male mice. Fadrozole treatment returned these levels to baseline values. Aromatase expression in the testes of infected male mice was not affected by Fadrozole. These results suggest that aromatase and IL-6 are key molecules in the production of the feminisation undergone by infected male mice and to Fadrozole treatment as a possible new therapeutic approach to cysticercosis.

Animals↗

PubMed2002

Lymphocytes and T lymphocyte subsets are regionally distributed in the female goat reproductive tract: influence of the stage of the oestrous cycle.

The reproductive tract of the female is a part of the mucosal system which protects from pathogens invasion. We have analysed the presence and distribution of total lymphocytes, plasma cells (antibody secreting B cells) and T lymphocytes subsets in the reproductive tract of the female goat. The influence of the oestrous cycle on the densities of lymphocytes and plasma cells of the cervix and uterus horn was evaluated in sections prepared for conventional histology. Immunocytochemistry was used for the study of lymphocyte subsets by confocal microscopy and immunoperoxidase techniques. Present results show that the reproductive tract of the goat is a site rich in lymphocytes. These cells were found mingled with the epithelial cells of the endometrium and distributed throughout the stroma. Lymphocyte aggregates were observed in the stroma. Lymphocyte but not plasma cell number changed depending on the reproductive stage of the goats. The impact of the hormonal environment was different for the cervix and uterine horn. Immunocytochemistry studies evidenced the presence of cells displaying immunoreactivity for both CD 4+ and CD 8+ antibodies in the epithelial layer and stroma of the cervix and uterine horn. These cells were more numerous in the cervix and were also found infiltrating the luminal epithelia of endometrial glands. Overall, our results indicate that lymphocyte distribution is different in the cervix and the horn, and is influenced by the stage of the reproductive cycle. In summary, CD 4+ and CD 8+ T lymphocytes subsets could be found in the endometrium of both the cervix and uterine horn of the goat reproductive tract.

Animals↗

PubMed2001

Insulin modifies the proliferation and function of chicken testis cells.

We investigated whether insulin plays a role in the proliferation and androgen production of chick testis cells. Testes from 18-d-old chick embryos or newly hatched chickens were dissociated and precultured in the presence of fetal bovine serum (FBS) for 24 h. After this period, testis cells from 18-d-old chick embryos were cultured in serum-free medium for 1 h with 0, 10, 50, or 100 microg/mL of insulin and were then exposed to human chorionic gonadotropin (hCG) for 3 h. In addition, some cells were incubated for 18 h with only insulin or insulin plus hCG. Androgens were measured by radioimmunoassay in the spent media. To study the influence of insulin on testis cell proliferation, cells were exposed to insulin for 18 h. A pulse of 3H-thymidine was added thereafter. We found that 18-d-old embryonic testis cells responded to hCG, increasing androgen production. Incubation with insulin for 1 h did not affect basal androgen production but modified the subsequent response to hCG. The addition of insulin plus hCG for 18 h resulted in important downregulation of the hCG effect. In addition, insulin significantly increased the proliferation of embryonic testis cells. The cells from testes of newly hatched chickens were precultured as described for embryonic cells and then exposed to insulin for 1 h in a serum-free medium. This treatment significantly increased the basal androgen production. Insulin also significantly enhanced the response to hCG of the testis cells from newly hatched chickens. These results strongly suggest that insulin has a role in the activity and in the proliferation of cultured testis cells throughout the perinatal period.

Androgens↗

PubMed2000

Sex steroids and parasitism: Taenia crassiceps cisticercus metabolizes exogenous androstenedione to testosterone in vitro.

Sex hormones are known to modulate immune responses and may be implicated in sex associated susceptibilities to infections. Taenia crassiceps cysticerci grow to larger numbers in female mice than in males. Gonadectomy alters the course of this infection and hormone replacement with 17beta-estradiol increases the parasite numbers. However, in chronic Taenia crassiceps cysticercosis the sex-hormone profile of males becomes more like that of the females' and progressively loose their sexual behavior. To have further insight in these outstanding endocrinological effects induced by the parasite upon the host, we investigated the parasite's capacity to produce sex steroids. In vitro experiments showed that Taenia crassiceps cysticerci transform 3H-Androstenedione to 3(H)-Testosterone, but not 3H-Pregnenolone. The production of 3H-Testosterone increased when the parasite numbers doubled. A recrystallisation procedure demonstrated that the metabolite identified by TLC was in fact testosterone. Thus, the cysticercus has the ability to use 3H-Androstenedione to make Testosterone possibly by a 17beta-Hydroxysteroid deshidrogenase-like activity in the parasite. In vivo, the parasite could use steroid precursors from the host to produce sex hormones, either accidentally or as needed for its own development, and thus alters the host's normal environment with sexual and immunological repercussions.

Androstenedione↗

PubMed1999

Developmental changes in LH secretion by male pituitaries in vitro: from the infantile to adult period.

The secretion of LH from the anterior pituitary of male rats was studied at different periods of postnatal development. According to an established classification we used rats 14 (infantile), 23 (juvenile), 45 (pubertal) and 90 (adult) days old. By using an in vitro incubation system, both basal and stimulated LH secretion were studied in the same gland. Age-related differences were observed in basal LH secretion, with juvenile and pubertal pituitaries showing higher secretion compared with infantile and adult pituitaries. However, the GnRH-induced secretory response was significantly higher in the infantile rats than in other ages. LH secretion was also studied in primary cultures from infantile or adult pituitaries. In 24 and 48 h cultures, infantile cells showed a significantly larger response to GnRH than that of adult cells. In the infantile pituitary LH-immunopositive cells showed differences in size at different locations in the gland. At the periphery of the lobes the predominant cells were smaller and angular shaped, whereas in the center of the gland the majority of the cells were ovoid shaped. In the adult pituitary, the predominant LH-positive cells were ovoid in shape and larger in size. Furthermore, 10% more LH-positive cells were observed in infantile pituitaries. On the basis of these data we propose that at the infantile period the male rat pituitary has two populations of LH-secreting cells, one with adult secretory function and shape and a second with increased sensitivity to GnRH and with a morphology atypical of the adult cell. The results presented support the hypothesis that the infantile period is a transitional stage in the rat pituitary development.

Analysis of Variance↗

PubMed1998

Effect of human and murine interferon-alpha on steroid production by rat ovarian cells.

The effect of interferon on the rat ovarian cell function was investigated. Cells from the ovary of juvenile rats were used as a model to investigate the effect of IFN-alpha on the secretion of estradiol and testosterone. In addition the effect of human IFN-alpha (hIFN-alpha) on the secretion of testosterone by the rat adult testis was studied. Present results show that leukocyte hIFN-alpha decreased the human chorionic gonadotropin (hCG) stimulated secretion of estradiol and testosterone by ovarian cells, and the production of testosterone by testis cells. Basal secretion of steroids was affected later and in less proportion than the hCG-dependent production. The IFN-alpha obtained from murine leukocytes, also inhibited the response of ovarian cells to the hCG stimulus.The nature of this effect in the secretion of the steroids is dose and time-dependent. The incubation of hIFN-alpha with an specific antibody completely blocked the effect of the cytokine on ovarian cells.

Animals↗

PubMed1997

Indeterminate cell histiocytosis: a rare histiocytic disorder.

A 64-year-old woman, otherwise healthy, presented with multiple reddish-brown, slightly yellowish papules on the face and neck, which had developed 3 years earlier. The lesions were painless and nonpruritic and varied in diameter from 1 to 5 mm. Histological and immunohistochemical examination of cutaneous biopsies revealed a diffuse dermal infiltrate composed mainly of histiocytes which expressed both Langerhans cell as well as monocytic/macrophages cell marker characteristics. Electron microscopic studies revealed no Birbeck granules within the cytoplasm of the neoplastic cells, leading to a diagnosis of indeterminate cell histiocytosis. Indeterminate cell histiocytosis is a very rare disease characterized by the proliferation of indeterminate histiocytes which morphologically and immunophenotypically resemble Langerhans cells but lack Birbeck granules.

Female↗

PubMed1996

Inhibition of sexual behavior in male mice infected with Taenia crassiceps cysticerci.

Prominent estrogenization and deandrogenization ensue in male mice as a consequence of experimental intraperitoneal infection with Taenia crassiceps cysticerci. The impact of these endocrine changes upon sexual behavior was explored in a group of infected Balb/c male mice at weekly intervals for 15 wk and compared with the behavior of otherwise paired, nonparasitized male mice. Mounting, intromission, and ejaculation responses markedly declined as infection progressed. Six weeks after infection, none of the infected mice displayed ejaculation, the number of mounts and intromissions gradually decreased, and their latencies increased, until, by the 13th wk, none of the parasitized mice showed any sexual response toward female mice. Fifteen weeks after infection, the number of metacestodes per host increased to a couple of thousand, the mean serum estradiol level was approximately 50 times higher than the normal value, and testosterone fell to 5% of its normal level. To fully assess that the inhibition of sexual behavior resulted from the decrease in testosterone levels, a group of 8-wk-infected mice received testosterone, and complete restoration of their sexual behavior was observed. Inhibition of masculine sexual behavior during the infection period is the result of hormonal changes, estradiol being ineffective in maintaining copulation.

Animals↗