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Biomedical subjects

F Paris

Publications and source records attributed to F Paris.

At least 19 recordsLinked to original sources
PubMed2006

The role of androgens or growth factors in the bone resorption process in recent spinal cord injured patients: a cross-sectional study.

STUDY DESIGN: This cross-sectional study compared the androgen and growth factor profiles and the bone turnover of patients with spinal cord injury (SCI) versus able-bodied controls (AB). OBJECTIVE: Determine whether androgens, GH, or either IGF-I or IGFBP-3, are implicated in bone turnover alteration in patients with recent SCI. SETTING: Propara Center, Montpellier, France. METHODS: In all, 16 men (31.3 years) with complete SCI, seven paraplegics and nine tetraplegics, who had sustained injury an average of 3 months earlier, and 12 AB who served as controls (27.5 years) participated. Androgens, growth hormone and its mediators were investigated. The bone resorption process was evaluated by urinary and plasma type I collagen C-telopeptide (CTXu, CTXp), while bone formation was evaluated by osteocalcin (OC) and bone alkaline phosphatase. RESULTS: Total testosterone (TT) and the free androgen index (FAI) were significantly lower in the SCI patients, whereas FSH was significantly higher (P<0.05). These hormonal variations were not related to the level of neurological lesion. There was no significant difference in GH, IGF-I, or IGFBP-3 levels. CTXu and CTXp indicated high bone resorption activity in the SCI patients (P<0.05). Regarding bone formation markers, only OC was affected by neurological lesion (P<0.05). Basal hormone levels did not correlate with markers of bone turnover. CONCLUSION: The high bone resorption process observed in SCI patients did not seem directly related to testicular endocrine abnormalities or an altered growth factor profile. Nevertheless, the reduced TT and FAI levels could be aggravating factors in the development of acute bone loss.

Adult↗
PubMed2006

Enteric glia inhibit intestinal epithelial cell proliferation partly through a TGF-beta1-dependent pathway.

Although recent studies have shown that enteric neurons control intestinal barrier function, the role of enteric glial cells (EGCs) in this control remains unknown. Therefore, our goal was to characterize the role of EGCs in the control of intestinal epithelial cell proliferation using an in vivo transgenic and an in vitro coculture model. Assessment of intestinal epithelial cell proliferation after ablation of EGCs in transgenic mice demonstrated a significant increase in crypt cell hyperplasia. Furthermore, mucosal glial network (assessed by immunohistochemical detection of S-100beta) is altered in colon adenocarcinoma compared with control tissue. In an in vitro coculture model of subconfluent Caco-2 cells seeded onto Transwell filters with EGCs, Caco-2 cell density and [3H]thymidine incorporation were significantly lower than in control (Caco-2 cultured alone). Flow cytometry analysis showed that EGCs had no effect on Caco-2 cell viability. EGCs induced a significant increase in Caco-2 cell surface area without any sign of cellular hypertrophy. These effects by EGCs were also seen in various transformed or nontransformed intestinal epithelial cell lines. Furthermore, TGF-beta1 mRNA was expressed, and TGF-beta1 was secreted by EGCs. Exogenously added TGF-beta1 reproduced partly the EGC-mediated effects on cell density and surface area. In addition, EGC effects on Caco-2 cell density were significantly reduced by a neutralizing TGF-beta antibody. In conclusion, EGCs have profound antiproliferative effects on intestinal epithelial cells. Functional alterations in EGCs may therefore modify intestinal barrier functions and be involved in pathologies such as cancer or inflammatory bowel diseases.

Adenocarcinoma↗
PubMed2005

[Clinical expression of precocious pubertal development in girls].

The paediatric endocrinologist is frequently asked whether pubertal development in a girl is normal, early or too early (precocious). This review will cover all clinical expression of premature development of puberty: central precocious puberty (neurogenic, secondary, and idiopathic) where treatment with GnRHa is considered, early puberty, partial puberty or pubertal variants and peripheral or pseudo precocious puberty related to an antonomous hypersecretion of estrogens by the ovaries. A special attention should be paid also to the role of environmental disruptors in the development of peripheral precocious puberty. GnRHa treatment should be considered only when evidence of central activation of the gonadotropic axis is proved by the LHRH-test.

Child↗
PubMed2005

Recent advances in the treatment of GERD in the elderly: focus on proton pump inhibitors.

The prevalence of gastroesophageal reflux disease (GERD) increases with age, and older people are more likely to develop severe disease. Studies of elderly patients with GERD indicate differences in presentation and diagnosis, compared with GERD in younger adults. Indeed, an older patient with GERD may present with atypical symptoms such as dysphagia, vomiting, weight loss, anaemia and anorexia, and less frequently with typical symptoms such as heartburn or acid regurgitation. These findings are attributed to pathophysiological changes in esophageal function that occur with age. Therefore, GERD in elderly patients is more likely to be poorly diagnosed or undiagnosed. Although few studies have concentrated specifically on elderly patients, the proton pump inhibitors (PPIs) have been shown to be more effective than histamine receptor antagonists for healing reflux esophagitis and for preventing its recurrence when they are given as maintenance therapy. In addition, the PPIs seem to be safe both in short- and in long-term therapy of elderly patients with GERD.

Acute Disease↗
PubMed2005

A nationwide study of granulosa cell tumors in pre- and postpubertal girls: missed diagnosis of endocrine manifestations worsens prognosis.

BACKGROUND: There are very few data on the natural history of ovarian granulosa cell tumors (OGCT) in children. The aim of this study was to determine whether early recognition and diagnosis of the initial endocrine signs could improve the outcome of these tumors. METHODS: In a nationwide study from 1990 to 2004, we analyzed the clinical, biological and pathologic data from 40 pre- and postpubertal girls presenting an OGCT. RESULTS: 1. Among the prepubertal girls (n = 29), 17 OGCTs were diagnosed on the basis of precocious pseudopuberty. None of the 17 girls had a peritoneal spread of the tumor (100% FIGO stage Ia). Diagnosis based on a tumoral or acute abdomen (12 cases) was associated with frequent intraperitoneal ruptures of the tumor (50%) and a risk of relapse (2 cases). Of the eight girls who had had a misdiagnosed precocious pseudopuberty, five had a pre- or perioperative tumoral rupture. 2. Among the postpubertal girls (n = 11), endocrine manifestations such as secondary amenorrhea or virilization had been underevaluated in three of them and the diagnosis was established from a tumoral abdomen. This clinical presentation was associated with frequent ruptures of the mass in the peritoneum (80%) and a higher risk of recurrence (30%). 3. A delayed diagnosis of OGCT despite previous endocrine signs (11 cases; 8 pre- and 3 postpubertal) was associated with a high risk of pre- or peri-operative peritoneal tumor spreading (70% FIGO stage Ic or IIc, p <0.05). The mean delay for diagnosis ranged from 3 to 11 months. CONCLUSION: This study highlights the critical role of early diagnosis of OGCT in pre- and postpubertal girls, particularly at the first seemingly banal signs of endocrine disorder. Peritoneal spread of the tumor may thereby be prevented, which improves the prognosis.

Abdominal Pain↗
PubMed2005

Influence of cognitive impairment and comorbidity on disability in hospitalized elderly patients.

BACKGROUND: The effects of cognitive impairment and comorbidity on the prevalence of disability in elderly patients who are hospitalized in acute wards are not well defined. OBJECTIVES: To evaluate the role of comorbidity and cognitive impairment on the prevalence of disability in a cohort of hospitalized older patients. PATIENTS AND METHODS: This study included 179 patients aged 65 years and over admitted to the Geriatric Unit of the Casa Sollievo della Sofferenza Hospital, in Italy. Cognitive status was evaluated by means of the Mini Mental State Examination (MMSE) and Clinical Dementia Rating Scale (CDR); the functional status was evaluated according to the Activity of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) indices. Comorbidity was identified using the Cumulative Illness Rating Scale (CIRS index). RESULTS: Of the 179 patients enrolled 73 patients were diagnosed with dementia [Alzheimers' Disease (AD) = 49 patients, Vascular Dementia (VD) = 24 patients], 35 patients with Mild Cognitive Impairment (MCI) and 71 patients had no cognitive impairment. The severity of disability was significantly higher in patients with dementia (ADL = 3.1 +/- 2.1, IADL = 1.5 +/- 2.0) than patients with MCI (ADL = 5.1 +/- 1.4, IADL = 5.2 +/- 2.2) (p < 0.0001) and patients without cognitive impairment (ADL = 5.5 +/- 0.9, IADL = 6.4 +/- 1.9) (p < 0.0001). No significant differences in CIRS index were observed between patients with dementia and MCI and no cognitive impairment patients (Dementia = 2.4 +/- 1.4 vs MCI = 2.9 +/- 1.4 vs No cognitive impairment = 2.7 +/- 1.2; p = 0.1). Moreover, a significant correlation between cognitive impairment and functional status (MMSE/ADL: r = 0.45, p = 0.0001, MMSE/IADL: r = 0.54, p = 0.0001) but not between comorbidity and functional status (CIRS/ADL: r = 0.0007, CIRS/IADL: r = 0.040) was observed. Separating patients with dementia by diagnosis of AD or VD, no significant differences in MMSE (AD = 12.2 +/- 6.7 vs VD = 13.2 +/- 6.5, p = 0.6), CDR (AD = 2.2 +/- 0.8 vs VD = 2.1 +/- 0.7, p = 0.6), ADL (AD = 3.1 +/- 2.1 vs VD = 3.0 +/- 2.1, p = 0.8), IADL (AD = 1.3 +/- 1.9 vs VD = 2.0 +/- 2.2, p = 0.1) or CIRS (AD = 2.2 +/- 1.5 vs VD = 2.8 +/- 1.3, p = 0.06) scores were observed. CONCLUSIONS: Cognitive impairment and not comorbidity, was significantly associated with disability in hospitalized older patients.

Activities of Daily Living↗
PubMed2004

Proton-pump inhibitors reduce the risk of uncomplicated peptic ulcer in elderly either acute or chronic users of aspirin/non-steroidal anti-inflammatory drugs.

BACKGROUND: Although administration of gastroprotective drugs may reduce the risk of peptic ulcers associated with the chronic use of non-steroidal anti-inflammatory drugs or aspirin, no consensus exists as to whether this co-therapy is effective for short-term prevention, particularly in old age. AIM: To evaluate the risk of peptic ulcer associated with acute and chronic non-steroidal anti-inflammatory drugs or aspirin therapy in elderly subjects, and the influence of antisecretory treatment on this risk. METHODS: The study included 676 elderly non-steroidal anti-inflammatory drugs or aspirin users and 2435 non-users who consecutively underwent upper gastrointestinal endoscopy. The use of non-steroidal anti-inflammatory drugs and/or aspirin as well as antisecretory drugs (H2-blockers and proton-pump inhibitors) was evaluated by a structured interview. Diagnosis of gastric and duodenal ulcer as well as Helicobacter pylori infection were carried out by endoscopy and histological examination of the gastric mucosa. RESULTS: About 47.3% of patients were acute and 52.7% chronic users of non-steroidal anti-inflammatory drugs or aspirin. The risk of peptic ulcer, adjusted for age, gender, H. pylori infection and antisecretory drug use was higher in acute (gastric ulcer: odds ratio, OR = 4.47, 95% CI: 3.19-6.26 and duodenal ulcer: OR = 2.39, 95% CI: 1.73-3.31) than chronic users (gastric ulcer: OR = 2.80, 95% CI: 1.97-3.99 and duodenal ulcer: OR = 1.68, 95% CI: 1.22-2.33). Proton-pump inhibitor treatment was associated with a reduced risk of peptic ulcer in both acute (OR = 0.70, 95% CI: 0.24-2.04) and chronic (OR = 0.32, 95% CI: 0.15-0.67) non-steroidal anti-inflammatory drugs/aspirin users. Conversely, concomitant treatment with H2-blockers was associated with a significantly higher risk of peptic ulcer both in acute (OR = 10.9, 95% CI: 3.87-30.9) and chronic (OR = 6.26, 95% CI: 2.56-15.3) non-steroidal anti-inflammatory drugs/aspirin users than non-users. Proton-pump inhibitor treatment resulted in an absolute risk reduction of peptic ulcer by 36.6% in acute and 34.6% in chronic non-steroidal anti-inflammatory drugs/aspirin users; indeed, the number needed to treat to avoid one peptic ulcer in elderly non-steroidal anti-inflammatory drugs/aspirin users was three both in acute and chronic users. CONCLUSIONS: These findings suggest that proton-pump inhibitor co-treatment is advisable in symptomatic elderly patients who need to be treated with non-steroidal anti-inflammatory drugs and/or aspirin for a short period of time.

Acute Disease↗
PubMed2004

[Polycystic ovary syndrome in pubertal period: clinical, biological, metabolic and genetic polymorphism].

Polycystic ovary syndrome (PCOS) is a common cause of hyperandrogenism in adolescent girls. In its complete post menarchal expression, the syndrome is characterized by the association of typical clinical, biological, and ultrasonographic findings. Many factors have contributed to our knowledge of different clinical forms of PCOS in adolescent girls. They are helpful for clarifying misleading situations in a period of life when diagnosis of PCOS implies a treatment for many years and may interfere with gynecological outcome. During the last 3 years, we had the opportunity to manage in our unit 45 adolescent girls with ovarian hyperandrogenism: 32 of them had PCOS and the other 13 functional ovarian hyperandrogenism defined by clinical and biological hyperandrogenism without ultrasonographic abnormality. In this review, we report, from our personal experience as well as from recent literature data, the different clinical expressions of PCOS in the pubertal period: the classical post menarchal form, the exceptional pre menarchal form, the post precocious pubarche and the post precocious puberty forms, the familial expression as well as the dominant metabolic expression.

Adolescent↗
PubMed2004

Mitochondrial DNA sequence diversity in a sedentary population from Egypt.

The mitochondrial DNA (mtDNA) diversity of 58 individuals from Upper Egypt, more than half (34 individuals) from Gurna, whose population has an ancient cultural history, were studied by sequencing the control-region and screening diagnostic RFLP markers. This sedentary population presented similarities to the Ethiopian population by the L1 and L2 macrohaplogroup frequency (20.6%), by the West Eurasian component (defined by haplogroups H to K and T to X) and particularly by a high frequency (17.6%) of haplogroup M1. We statistically and phylogenetically analysed and compared the Gurna population with other Egyptian, Near East and sub-Saharan Africa populations; AMOVA and Minimum Spanning Network analysis showed that the Gurna population was not isolated from neighbouring populations. Our results suggest that the Gurna population has conserved the trace of an ancestral genetic structure from an ancestral East African population, characterized by a high M1 haplogroup frequency. The current structure of the Egyptian population may be the result of further influence of neighbouring populations on this ancestral population.

DNA, Mitochondrial↗
PubMed2003

Possible applications of aquatic bioregenerative life support modules for food production in a Martian base.

Water is the essential precondition of life in general and also for the establishment of a Martian base suitable for long duration stays of humans. It is not yet proven if there is indeed a "frozen ocean" under the surface of Mars but if this could be verified it would open innovative aspects for the construction of bioregenerative life support systems (BLSS). In a general concept higher plants will play the predominant role in a Martian BLSS. It is not clear, however, how these will grow and bring seed in reduced gravity and there may be differences in the productivity in comparison to Earth conditions. Therefore, organisms which are already adapted to low gravity conditions, namely non-gravitropic aquatic plants and also aquatic animals may be used to enhance the functionality of the Martian BLSS as a whole. It has been shown already with the so-called C.E.B.A.S. MINIMODULE in the STS-89 and STS-90 spaceshuttle missions that the water plant Ceratophyllum demersum has an undisturbed and high biomass production under space conditions. Moreover, the teleost fish species Xiphophorus helleri adapted easily to the micro-g environment and maintained its normal reproductive functions. Based on this findings a possible scenario is presented in which aquatic plant production modules and combined animal-plant production systems may be used for human food production and water and air regeneration in a Martian base.

Animals↗
PubMed2003

Testosterone is significantly reduced in endurance athletes without impact on bone mineral density.

AIMS: To compare the basal plasma reproductive hormonal profile in three groups of athletes involved in different training programs, and to define the relationship between androgen level and bone mineral density (BMD) in male athletes. METHODS: Basal serum total testosterone (TT), free androgen index (FAI), sex hormone-binding globulin (SHBG), cortisol, cortisol to TT ratio, luteinizing hormone (LH), estrogen and BMD were evaluated in cyclists (CY; n = 11), triathletes (TR; n = 14) and swimmers (SW; n = 13) and compared with less active controls (n = 10). RESULTS: TT and FAI levels were lower (p < 0.05) in CY and TR, whereas the ratio of cortisol to TT was increased in CY only (p < 0.05). No alteration in serum LH, SHBG, estrogen or cortisol concentration was observed. BMD was higher in the proximal femur in TR (p < 0.05). No BMD or hormonal differences were found in SW. CONCLUSION: Only the endurance training of CY and TR induced androgen deficiency without apparent alteration of BMD.

Adult↗
PubMed2002

[The androgen receptor: molecular pathology].

Androgens play a crucial role in the development, maintenance and regulation of male phenotype and reproductive physiology through the androgen receptor, a transcription factor. Testosterone or dihydrotestosterone binding induces a trans-conformation of the androgen receptor and allows its translocation into the nucleus, where it recognizes specific DNA sequences. Recent developments in molecular genetics, as well as structural analysis of the androgen receptor, allow a better understanding of the structure/function relationship of this nuclear receptor. Molecular analyses of androgen insensitivity syndrome, as well as hormone-resistant prostate cancer, Kennedy's disease and isolated male infertility, have been proved useful as privileged models for this purpose. In the absence of identified AR receptor mutations in androgen insensitivity syndromes, abnormalities of transcriptional cofactor should be considered. Finally, identification of androgen-dependent genes will be helpful for evaluating the degree of the molecular defect of androgen action within target cells.

Active Transport, Cell Nucleus↗
PubMed2001

Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice.

Gastrointestinal (GI) tract damage by chemotherapy or radiation limits their efficacy in cancer treatment. Radiation has been postulated to target epithelial stem cells within the crypts of Lieberkühn to initiate the lethal GI syndrome. Here, we show in mouse models that microvascular endothelial apoptosis is the primary lesion leading to stem cell dysfunction. Radiation-induced crypt damage, organ failure, and death from the GI syndrome were prevented when endothelial apoptosis was inhibited pharmacologically by intravenous basic fibroblast growth factor (bFGF) or genetically by deletion of the acid sphingomyelinase gene. Endothelial, but not crypt, cells express FGF receptor transcripts, suggesting that the endothelial lesion occurs before crypt stem cell damage in the evolution of the GI syndrome. This study provides a basis for new approaches to prevent radiation damage to the bowel.

Animals↗
PubMed2001

Environmental xenoestrogens, antiandrogens and disorders of male sexual differentiation.

Over the past 20 years, the documented increase in the disorders of male sexual differentiation, such as hypospadias, cryptorchidism, and micropenis, has led to the suspicion that environmental chemicals are detrimental to normal male genital development in utero. Male sexual differentiation is critically dependent on the normal action of androgens, and unbalanced androgen/estrogen ratios can disturb it. Environmental xenoestrogens (such as herbicides, pesticides, PCBs, plasticizers, and polystyrenes) that mimic estrogens or environmental antiandrogens (such as polyaromatic hydrocarbons, linuron, vinclozolin, and pp'DDE) that disturb endocrine balance, cause demasculinizing effects in the male foetus. These environmental chemicals are often referred to as endocrine disruptors: they are thought to mimic endogenous estrogens by entering the cell, binding to the receptor and activating transcription, they may also antagonize normal androgen action. We have established numerous cell lines to assess the estrogenicity and antiandrogenicity of compounds found in the environment and to identify new products present in wastewater effluents that are able to disrupt endocrine functions. Several cell lines responding to estrogens have been obtained in our group, including cells with different enzymatic equipment and cells expressing chimeric receptor or natural estrogen receptors alpha and beta. These cell lines have proved to be useful for assessing the biological activity of pesticides, fungicides, and chemicals found in plastic or discarded in the environment. In order to generate a powerful tool for the investigation of androgen action and the rapid screening of potential antagonists, we developed a new stable prostatic cell line. The PALM cell line is an original cellular model to characterize the response of hAR, and it provides an easy and rapid bioluminescent test to identify new antagonists. We also developed a model based on a fusion protein between the androgen receptor (AR) and the green fluorescent protein (GFP) to study the intracellular dynamics of AR. The GFP-AR model was applied to define the ability of several xenoestrogens and antiandrogens to inhibit the nuclear transfer of AR. The ubiquitous presence of endocrine disruptors in the environment and the increased incidence of neonatal genital malformation support the hypothesis that disturbed male sexual differentiation may in some cases be caused by increased exposure to environmental xenoestrogens and/or antiandrogens.

Androgen Antagonists↗
PubMed2001

Ceramide enables fas to cap and kill.

Recent studies suggest that trimerization of Fas is insufficient for apoptosis induction and indicate that super-aggregation of trimerized Fas might be prerequisite. For many cell surface receptors, cross-linking by multivalent ligands or antibodies induces their lateral segregation within the plasma membrane and co-localization into "caps" on one pole of the cell. In this study, we show that capping of Fas is essential for optimal function and that capping is ceramide-dependent. In Jurkat T lymphocytes and in primary cultures of hepatocytes, ceramide elevation was detected as early as 15-30 s and peaked at 1 min after CH-11 and Jo2 anti-Fas antibody treatment, respectively. Capping was detected 30 s after Fas ligation, peaked at 2 min, and was maintained at a lower level for as long as 30 min in both cell types. Ceramide generation appeared essential for capping. Acid sphingomyelinase -/- hepatocytes were defective in Jo2-induced ceramide generation, capping, and apoptosis, and nanomolar concentrations of C(16)-ceramide restored these events. To further explore the role of ceramide in capping of Fas, we employed FLAG-tagged soluble Fas ligand (sFasL), which binds trimerized Fas but is unable to induce capping or apoptosis in Jurkat cells. Cross-linking of sFasL with M2 anti-FLAG antibody induced both events. Pretreatment of cells with natural C(16)-ceramide bypassed the necessity for forced antibody cross-linking and enabled sFasL to cap and kill. The presence of intact sphingolipid-enriched membrane domains may be essential for Fas capping since their disruption with cholesterol-depleting agents abrogated capping and prevented apoptosis. These data suggest that capping is a ceramide-dependent event required for optimal Fas signaling in some cells.

Animals↗
PubMed2001

Aquatic food production modules in bioregenerative life support systems based on higher plants.

Most bioregenerative life support systems (BLSS) are based on gravitropic higher plants which exhibit growth and seed generation disturbances in microgravity. Even when used for a lunar or martian base the reduced gravity may induce a decreased productivity in comparison to Earth. Therefore, the implementation of aquatic biomass production modules in higher plant and/or hybrid BLSS may compensate for this and offer, in addition, the possibility to produce animal protein for human nutrition. It was shown on the SLS-89 and SLS-90 space shuttle missions with the C.E.B.A.S.-MINI MODULE that the edible non gravitropic rootless higher aquatic plant Ceratophyllum demeresum exhibits an undisturbed high biomass production rate in space and that the teleost fish species, Xiphophorus helleri, adapts rapidly to space conditions without loss of its normal reproductive functions. Based on these findings a series of ground-based aquatic food production systems were developed which are disposed for utilization in space. These are plant production bioreactors for the species mentioned above and another suitable candidate, the lemnacean (duckweed) species, Wolffia arrhiza. Moreover, combined intensive aquaculture systems with a closed food loop between herbivorous fishes and aquatic and land plants are being developed which may be suitable for integration into a BLSS of higher complexity. Grant numbers: WS50WB9319-3, IVA1216-00588.

Animals↗