A new insight into the molecular basis of 3beta-hydroxysteroid dehydrogenase deficiency

Classical 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3beta-HSD) deficiency is a rare form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene, causing varying degrees of salt-loss in both sexes and incomplete masculinization of the external genitalia in genetic males. To date a total of 34 mutations (including 5 frameshift, 4 nonsense, 1 in-frame deletion, 1 splicing and 23 missense mutations) have been identified in the HSD3B2 gene. Results from functional charaterization studies of the mutant proteins agrees with the prediction that no functional type II 3beta-HSD isoenzyme is expressed in the adrenals and gonads of the patients with the severe salt-losing form, whereas the nonsalt-losing form causes an incomplete loss in enzymatic activity, thereby leaving sufficient enzymatic activity to prevent salt loss. Recent studies have highlighted the fact that various mutations appear to have a drastic effect upon the stability of the protein, therefore providing molecular evidence of a new mechanism involved in classical 3beta-HSD deficiency. Finally, the functional characterization of the missense mutations known to be involved in this autosomal recessive disorder provides valuable information concerning the structure-function relationships of the 3beta-HSD enzyme superfamily.

Bilateral laparoscopic adrenalectomy for congenital adrenal hyperplasia with severe hypertension, resulting from two novel mutations in splice donor sites of CYP11B1

We present an in vivo and in vitro study of congenital adrenal hyperplasia in a patient with 11beta-hydroxylase deficiency. Sequencing of the CYP11B1 gene showed two new base substitutions, a conservative 954 G-->C transversion at the last base of exon 5 (T318T), and a IVS8 + 4A-->G transition in intron 8. In addition, two polymorphisms were found in exons 1 and 2. The genetically female patient was raised as a male because of severe pseudohermaphroditism. Glucocorticoid-suppressive treatment encountered difficulties in equilibration and compliance, resulting in uncontrolled hypertension with pronounced hypertrophic cardiomyopathy. At 42 yr of age the occurrence of central retinal vein occlusion with permanent loss of left eye vision led to the decision to perform bilateral laparoscopic adrenalectomy. Surgery was followed by normalization of blood pressure and good compliance with glucocorticoid and androgen substitutive therapies. In vitro, adrenal cells in culture and isolated mitochondria showed extremely low 11beta-hydroxylase activity. Analysis of adrenal CYP11B1 messenger ribonucleic acid (mRNA) by RT-PCR and sequencing showed the expression of a shorter mRNA that lacked exon 8 and did not contain either the exon 5 mutation or the exon 1 and 2 polymorphisms. This suggested that one CYP11B1 allele carried the intron 8 mutation, responsible for skipping exon 8. The other allele carried the exon 5 mutation, and its mRNA was not detectable. Western blot analysis showed weak expression of a shorter CYP11B immunoreactive band of 43 kDa, consistent with truncation of exon 8. Thus, bilateral adrenalectomy in this patient allowed effective treatment of severe hypertension and helped in understanding the mechanisms and physiopathological consequences of two novel mutations of CYP11B1.

Clinical report of three patients with hereditary hemochromatosis and movement disorders

Neurologic manifestations are rarely described in hereditary hemochromatosis (HH). We describe three patients with HH and movement disorders. Patient 1, a 69-year-old man, had a 13-year history of disabling cerebellar syndrome, action tremor and myoclonus, and secondary dementia. Patient 2 was a 40-year-old man with a 9-year history of cerebellar syndrome, head and arm tremor, and cervical dystonia. Patient 3, a 75-year-old woman, had a 5-year history of rapidly disabling parkinsonian syndrome unresponsive to levodopa. The diagnosis of HH was established in the three patients by iron tests, evidence of a C282Y mutation, and, in two patients, by liver biopsy. High-field T2-weighted magnetic resonance imaging showed hyperintense signals in hemispheric white matter in patient 1, cerebellar atrophy in patient 2, and cerebellar and cerebral atrophy in patient 3 and no significant hypointense signals in the three patients. Phlebotomies and symptomatic treatments did not change the course of the disease. Our cases are compared with the five previously reported observations of HH with movement disorders. This rare association is one cause of the chronic acquired non-Wilsonian hepatocerebral degeneration syndromes and represents a separate entity from aceruloplasminemia. The pathophysiologic mechanism of movement disorders in HH is unresolved. No hepatic insufficiency and portosystemic encephalopathy is evidenced in our cases, whereas the putative role of abnormal iron load remains to be ascertained. HH should be investigated more systematically in patients with movement disorders.

Reciprocal expression of the TNF family receptor herpes virus entry mediator and its ligand LIGHT on activated T cells: LIGHT down-regulates its own receptor

The TNF receptor (TNFR) family plays a central role in the development of the immune response. Here we describe the reciprocal regulation of the recently identified TNFR superfamily member herpes virus entry mediator (HVEM) (TR2) and its ligand LIGHT (TL4) on T cells following activation and the mechanism of this process. T cell activation resulted in down-regulation of HVEM and up-regulation of LIGHT, which were both more pronounced in CD8(+) than CD4(+) T lymphocytes. The analysis of HVEM and LIGHT mRNA showed an increase in the steady state level of both mRNAs following stimulation. LIGHT, which was present in cytoplasm of resting T cells, was induced both in cytoplasm and at the cell surface. For HVEM, activation resulted in cellular redistribution, with its disappearance from cell surface. HVEM down-regulation did not rely on de novo protein synthesis, in contrast to the partial dependence of LIGHT induction. Matrix metalloproteinase inhibitors did not modify HVEM expression, but did enhance LIGHT accumulation at the cell surface. However, HVEM down-regulation was partially blocked by a neutralizing mAb to LIGHT or an HVEM-Fc fusion protein during activation. As a model, we propose that following stimulation, membrane or secreted LIGHT binds to HVEM and induces receptor down-regulation. Degradation or release of LIGHT by matrix metalloproteinases then contributes to the return to baseline levels for both LIGHT and HVEM. These results reveal a self-regulating ligand/receptor system that contributes to T cell activation through the interaction of T cells with each other and probably with other cells of the immune system.

A repressive cross-regulation between catalytic and promoter activities of the CYP1A1 and CYP2E1 genes: role of H(2)O(2)

Cytochrome P450 enzymes catalyze the first step of the metabolism and subsequent elimination of hydrophobic xenobiotics. However, the activity of some isoforms, among them CYP1A1 and CYP2E1, may result in cellular insults such as oxidative stress and activation of procarcinogen compounds into reactive metabolites. The regulation of the expression of these enzymes is therefore important. We have previously shown that the CYP1A1 gene promoter was repressed by oxidative stress. We show here that the CYP2E1 gene promoter is down-regulated by exogenous H(2)O(2) addition and glutathione depletion. It is also repressed by the transfection of a CYP2E1 expression vector, which elicits an intracellular H(2)O(2) generation. This autoregulation is limited by catalase (which catalyzes the catabolism of H(2)O(2)), thus implying H(2)O(2) as a mediator of the negative feedback mechanism. Furthermore, we observed that the activity of CYP1A1 resulting either from the stimulation of the endogenous gene by benzo[a]pyrene treatment or from the transfection of an expression vector, repressed the activity of the CYP2E1 gene promoter. Conversely, CYP2E1 overexpression repressed the activity of the CYP1A1 gene promoter. In both cases, catalase and a specific inhibitor of one enzyme prevented the repression of the other. This suggests that the generation of H(2)O(2) during the catalytic cycle of these enzymes is a mediator of the cross-regulatory mechanisms. These novel repressive mechanisms of autoregulation and cross-regulation using H(2)O(2) as a common mediator may limit the potential toxicity resulting from high cytochrome P450 activity within the cell.

The repression of nuclear factor I/CCAAT transcription factor (NFI/CTF) transactivating domain by oxidative stress is mediated by a critical cysteine (Cys-427)

The activity of the nuclear factor I/CCAAT transcription factor (NFI/CTF) is negatively regulated by oxidative stress. The addition of relatively high (millimolar) H(2)O(2) concentrations inactivates cellular NFI DNA-binding activity whereas lower concentrations can repress NFI/CTF transactivating function. We have investigated the mechanism of this regulation using Gal4 fusion proteins and transfection assays. We show that micromolar H(2)O(2) concentrations repress the transactivating domain of NFI/CTF in a dose-dependent manner and are less or not active on other transcription factors' transactivating domains. Studies using deletions and point mutations pointed to the critical role of Cys-427. Indeed, when this cysteine is mutated into a serine, the repression by H(2)O(2) is totally blunted. Mutation of other cysteine, serine and tyrosine residues within the transactivating domain had no clear effect on the repression by H(2)O(2). Finally, treatment of cells with the thiol-alkylating reagent N-ethylmaleimide leads to a decrease in the transactivating function, which is dependent on Cys-427. This study shows that transactivating domains of transcription factors can constitute very sensitive targets of oxidative stress and highlights the critical role of these domains.

New insight into the molecular basis of 3beta-hydroxysteroid dehydrogenase deficiency: identification of eight mutations in the HSD3B2 gene eleven patients from seven new families and comparison of the functional properties of twenty-five mutant enzymes

Classical 3beta-hydroxysteroid dehydrogenase/delta5-delta4 isomerase (3betaHSD) deficiency is a form of congenital adrenal hyperplasia that impairs steroidogenesis in both the adrenals and gonads resulting from mutations in the HSD3B2 gene and causing various degrees of salt-wasting in both sexes and incomplete masculinization of the external genitalia in genetic males. To identify the molecular lesion(s) in the HSD3B2 gene in the 11 patients from the seven new families suffering from classical 3betaHSD deficiency, the complete nucleotide sequence of the whole coding region and exon-intron splicing boundaries of this gene was determined by direct sequencing. Five of these families were referred to Morel's molecular diagnostics laboratory in France, whereas the two other families were investigated by Peter's group in Germany. Functional characterization studies were performed by Simard's group in Canada. Following transient expression in 293 cells of each of the mutant recombinant proteins generated by site-directed mutagenesis, the effect of the 25 mutations on enzyme activity was assessed by incubating intact cells in culture with 10 nM [14C]-DHEA as substrate. The stability of the mutant proteins has been investigated using a combination of Northern and Western blot analyses, as well as an in vitro transcription/translation assay using rabbit reticulocyte lysates. The present report describes the identification of 8 mutations, in seven new families with individuals suffering from classical 3betaHSD deficiency, thus increasing the number of known HSD3B2 mutations involved in this autosomal recessive disorder to 31 (1 splicing, 1 in-frame deletion, 3 nonsense, 4 frameshift and 22 missense mutations). In addition to the mutations reported here in these new families, we have also investigated for the first time the functional significance of previously reported missense mutations and or sequence variants namely, A82T, A167V, L173R, L205P, S213G and K216E, P222H, T259M, and T259R, which have not previously been functionally characterized. Furthermore, their effects have been compared with those of the 10 previously reported mutant enzymes to provide a more consistent and comprehensive study. The present results are in accordance with the prediction that no functional 3betaHSD type 2 isoenzyme is expressed in the adrenals and gonads of the patients suffering from a severe salt-wasting form of CAH due to classical 3betaHSD deficiency. Whereas the nonsalt-losing form also results from missense mutation(s) in the HSD3B2 gene, which cause an incomplete loss in enzyme activity, thus leaving sufficient enzymatic activity to prevent salt wasting. The functional data described in the present study concerning the sequence variants A167V, S213G, K216E and L236S, which were detected with premature pubarche or hyperandrogenic adolescent girls suspected to be affected from nonclassical 3betaHSD deficiency, coupled with the previous studies reporting that no mutations were found in both HSD3B1 and/or HSD3B2 genes in such patients strongly support the conclusion that this disorder does not result from a mutant 3betaHSD isoenzyme. The present study provides biochemical evidence supporting the involvement of a new molecular mechanism in classical 3betaHSD deficiency involving protein instability and further illustrates the complexity of the genotype-phenotype relationships of this disease, in addition to providing further valuable information concerning the structure-function relationships of the 3betaHSD superfamily.

An autoregulatory loop controlling CYP1A1 gene expression: role of H(2)O(2) and NFI

Cytochrome P450 1A1 (CYP1A1), like many monooxygenases, can produce reactive oxygen species during its catalytic cycle. Apart from the well-characterized xenobiotic-elicited induction, the regulatory mechanisms involved in the control of the steady-state activity of CYP1A1 have not been elucidated. We show here that reactive oxygen species generated from the activity of CYP1A1 limit the levels of induced CYP1A1 mRNAs. The mechanism involves the repression of the CYP1A1 gene promoter activity in a negative-feedback autoregulatory loop. Indeed, increasing the CYP1A1 activity by transfecting CYP1A1 expression vectors into hepatoma cells elicited an oxidative stress and led to the repression of a reporter gene driven by the CYP1A1 gene promoter. This negative autoregulation is abolished by ellipticine (an inhibitor of CYP1A1) and by catalase (which catalyzes H(2)O(2) catabolism), thus implying that H(2)O(2) is an intermediate. Down-regulation is also abolished by the mutation of the proximal nuclear factor I (NFI) site in the promoter. The transactivating domain of NFI/CTF was found to act in synergy with the arylhydrocarbon receptor pathway during the induction of CYP1A1 by 2,3,7,8-tetrachloro-p-dibenzodioxin. Using an NFI/CTF-Gal4 fusion, we show that NFI/CTF transactivating function is decreased by a high activity of CYP1A1. This regulation is also abolished by catalase or ellipticine. Consistently, the transactivating function of NFI/CTF is repressed in cells treated with H(2)O(2), a novel finding indicating that the transactivating domain of a transcription factor can be targeted by oxidative stress. In conclusion, an autoregulatory loop leads to the fine tuning of the CYP1A1 gene expression through the down-regulation of NFI activity by CYP1A1-based H(2)O(2) production. This mechanism allows a limitation of the potentially toxic CYP1A1 activity within the cell.

Repression of gene expression by oxidative stress

Gene expression is modulated by both physiological signals (hormones, cytokines, etc.) and environmental stimuli (physical parameters, xenobiotics, etc.). Oxidative stress appears to be a key pleiotropic modulator which may be involved in either pathway. Indeed, reactive oxygen species (ROS) have been described as second messengers for several growth factors and cytokines, but have also been shown to rise following cellular insults such as xenobiotic metabolism or enzymic deficiency. Extensive studies on the induction of stress-response genes by oxidative stress have been reported. In contrast, owing to the historical focus on gene induction, less attention has been paid to gene repression by ROS. However, a growing number of studies have shown that moderate (i.e. non-cytotoxic) oxidative stress specifically down-regulates the expression of various genes. In this review, we describe the alteration of several physiological functions resulting from oxidative-stress-mediated inhibition of gene transcription. We will then focus on the repressive oxidative modulation of various transcription factors elicited by ROS.

Metformin treatment leads to an increase in basal, but not insulin-stimulated, glucose disposal in obese patients with impaired glucose tolerance

AIMS

This study was initiated to test the hypothesis that metformin treatment leads to enhanced glucose disposal at ambient insulin concentrations.

METHODS

Nineteen obese patients with impaired glucose tolerance (IGT) were treated with either metformin or placebo in a randomized, double-blind, placebo-controlled, cross-over study. Insulin secretion and insulin resistance were quantified using the homeostasis model assessment (HOMA) and insulin-stimulated glucose disposal were measured by determining the steady-state plasma glucose (SSPG).

RESULTS

The average benefit of metformin was 0.6 mmol/l for glucose (95% confidence interval (CI) 0.2-0.9 P = 0.002), 2.8 pmol/l for insulin (95% CI 0.2-5.4, P = 0.019). Insulin resistance, as quantified by HOMA, was improved by 1.1 (95% CI 0.2-2.0, P = 0.004), without any change in insulin secretion. Basal and insulin-stimulated glucose oxidation were comparable in the placebo and metformin-treated groups at the end of each treatment period, as was the SSPG concentration. However, both systolic and diastolic blood pressures fell significantly following metformin administration as compared to treatment with placebo.

CONCLUSIONS

These results indicate that metformin administration to patients with IGT is associated with enhanced glucose disposal at baseline insulin concentrations and a fall in blood pressure. In contrast, neither glucose oxidation nor glucose disposal were increased in association with metformin treatment under conditions of physiological hyperinsulinaemia.

[Genetic anomalies of the gonadotropic axis]

Some forms of isolated hypogonadotropic hypogonadism are caused by mutations of the GnRH receptor gene. These mutations lead to inactivation of the receptor and are recessive. A unique disease that associates hypogonadotropic hypogonadism and congenital hyperplasia is caused by mutations in the DAX-1 gene, situated on chromosome X. The pathogenesis to these endocrine defects remains now elusive. Kallmann syndrome represents the association of hypogonadotropic hypogonadism due to GnRH deficiency, and anosmia. Additional developmental anomalies can be present. Three modes of inheritance have been described: X-linked, autosomal recessive and autosomal dominant. The X-linked KAL-1 gene has been cloned. It encodes an extracellular matrix protein, anosmin-1, the study of which should lead to a better understanding of this developmental disease.

[Agenesis of the vas deferens in male infertility. A tentative classification based on 39 cases]

OBJECTIVES

We attempted to establish a classification of vas deferens agenesia observed in male infertility to better ascertain the pathophysiology involved and help guide genetic counselling.

PATIENTS AND METHODS

Among 387 men consulting for infertility, agenesia of the vas deferens was confirmed by transrectal ultrasonography in 39. A search for 13 different cystic fibrosis mutations was performed in subjects without associated renal agenesia.

RESULTS

Among the 39 cases, we identified 4 ultrasonographic categories: unique bilateral agenesia (25 cases), bilateral agenesia associated with renal agenesia (1 case), unique unilateral agenesia (6 cases) and unilateral agenesia with renal agenesia (7 cases). Presence or absence of a seminal vesicle was variable. A cystic fibrosis mutation was observed in 64% of the bilateral cases and in none of the unilateral cases. The delta F 508 mutation accounted for 62% of the mutations. Phenotypically, there was not distinction between patients with and without a mutation. In cases of unilateral agenesia of the vas deferens, azoospermia was more frequent in unique forms than in forms with associated renal agenesia.

CONCLUSION

Presence or absence of a mutation does not affect the pathophysiology of vas deferens agenesia in cases without associated renal agenesia. Genetic counselling should however take into account the presence of an associated mutation. Vas deferens agenesia associated with renal agenesia is not associated with cystic fibrosis mutations and results from a different pathogenic mechanism.

Isolated aldosterone synthase deficiency caused by simultaneous E198D and V386A mutations in the CYP11B2 gene

Isolated deficiencies in aldosterone biosynthesis are caused by mutations in the CYP11B2 (aldosterone synthase) gene. Patients with this deficiency have impaired aldosterone synthesis, exhibit increased plasma renin activity, secrete increased amounts of the steroid precursors DOC, corticosterone, and 18OHDOC, and are subject to salt wasting and poor growth. Two forms are generally distinguished. The first, corticosterone methyloxidase type I (CMO I or type 1 deficiency), is characterized by no detectable aldosterone secretion, a low or normal secretion of the steroid 18OHB, and are always found to have mutations that completely inactivate the encoded CYP11B2 enzyme. The second form (CMO II or type 2 deficiency) may have low to normal levels of aldosterone, but at the expense of greatly increased secretion of its immediate precursor 18OHB. These patients usually have a CYP11B2 enzyme with some residual enzymatic activity, especially 11beta-hydroxylase activity. We have studied two twins with an isolated aldosterone synthase activity who have a clinical profile typical of the type 1 deficiency. Their CYP11B2 genes are homozygous for three sequence changes, R173K, E198D, and V386A. In transfection assays these substitutions individually have modest effects on the encoded enzyme, but when found together they result in an enzyme with a decreased 11beta-hydroxylase activity, a large decrease of 18-hydroxylase activity, and no detectable 18-oxidase activity. This residual activity is more typical of that observed in patients classified as having CMO II deficiency, rather than CMO I deficiency, where no activity is detectable. This disparity between the CYP11B2 enzyme with residual activity and a clinical phenotypic typical of the type 1 deficiency, suggests that phenotype genotype relationships are not yet fully understood.

Down-regulation of cytochrome P450 1A1 gene promoter by oxidative stress. Critical contribution of nuclear factor 1

Oxidative stress interferes with several cellular functions, in particular transcriptional regulation. We show here that the human cytochrome P450 1A1 (CYP1A1) is down-regulated at the transcriptional level by oxidative stress. Basal as well as 2,3,7, 8-tetrachloro-p-dioxin-induced promoter activities are strongly impaired by H2O2 treatment or glutathione depletion with L-buthionine-(S,R)-sulfoximine. Tumor necrosis factor alpha inhibits CYP1A1 expression, and this inhibition is prevented by the antioxidant pyrrolidine dithiocarbamate. We show that these regulations depend on the integrity of the nuclear factor 1 (NFI) site located in the proximal promoter. We therefore examined the redox regulation of this transcription factor. Treatment of human HepG2 or rat H4 hepatoma cells with H2O2 or L-buthionine-(S, R)-sulfoximine inactivates the binding of the NFI transcription factor to its DNA consensus sequence. Furthermore, H2O2 treatment leads to a dose-dependent decrease of reporter gene expressions driven by promoters containing NFI binding sites. Glutathione depletion and catalase inhibition also repress a NFI-driven promoter. Under the same conditions, the CP-1 transcription factor activity is not affected by oxidative stress. Thus, NFI seems particularly sensitive to oxidative stress. This accounts, at least partially, for the regulation of cyp1A1 gene expression.

Contrast sensitivity in obese dyslipidemic patients with insulin resistance

OBJECTIVE

To evaluate contrast sensitivity in insulin-resistant obese patients and in aretinopathic diabetic patients.

METHODS

Contrast sensitivity was measured at 3 letter sizes (44 x 44, 9 x 9, and 5 x 5 mm) in mesopic (5 candela [cd]/m2) and low photopic (85 cd/m2) vision in 20 dyslipidemic obese patients with insulin resistance, 20 age-matched patients with type 2 diabetes mellitus, and 20 aged-matched healthy control subjects.

RESULTS

Significant loss of contrast sensitivity at all 3 letter sizes was observed in low photopic vision (at 44 x 44-mm letter size, control vs obese, P<.002, and control vs diabetic, P<.005; at 9 x 9-mm letter size, control vs obese, P<.02, and control vs diabetic, P<.001; and at 5 x 5-mm letter size, control vs obese, P<.05, and control vs diabetic, P<.005) and mesopic vision (at 44 x 44-mm letter size, control vs diabetic, P<.005; at 9 x 9-mm letter size, control vs obese, P<.005, and control vs diabetic, P<.01; and at 5 x 5-mm letter size, control vs obese, P<.005, and control vs diabetic, P<.001) in insulin-resistant obese and diabetic patients.

CONCLUSION

The results suggest that an early neurosensory dysfunction may occur without visible vascular involvement and without overt hyperglycemia.

Prenatal treatment of congenital adrenal hyperplasia

Prenatal diagnosis of congenital adrenal hyperplasia (CAH) is accurate and prenatal therapy is effective in significantly reducing or even eliminating virilization of females affected by CAH, sparing these children the consequences of genital surgery, sex missassignment and gender confusion. However, both the physical and psychological development of these children and the possibility of long-range adverse effects in the mothers need to be evaluated further. Prospective multicentre studies covering several decades are being designed.

The added value of therapy in diabetes: the education of patients for self-management of their disease

The long-term success of diabetes therapy is strongly dependent on education of the patient. Considerable emphasis and effort has been directed at this dimension of treatment by healthcare providers (HCPs) in the field of diabetology. Education of patients is not aimed at making them more knowledgable about their disease, but to help them better manage their treatment and adapt the diabetes control to the constant changes in daily life. Patient education is a complex process, and many factors may interfere with the patient's understanding. There is growing awareness among HCPs that more knowledge and skill have to be acquired in the field of therapeutic education of patients.

Personalities and alimentary behaviors in obese patients

The actual tendency in the care of obese patients is the association of dietetic information with an eating behavior therapy. Studies attempting to attribute the origin of obesity to psychiatric pathologies are contradictory. We studied whether certain eating disorders are more specific to a personality type. We studied eating disorders with the Eating Disorder Inventory (EDI) test in 281 obese women compared to 252 age-matched non-obese women. Both obese patients and non-obese volunteers were divided into four groups depending upon their personality (PERSONA test). This test defines four types of personality, based on the level of emotion (expansive or reserved) and the degree of power (dominant or consenting). According to our study, eating disorders vary between the four personality groups and were significantly higher in the facilitating group (consenting and expansive) compared to the three other obese groups. Neither promoting (expansive and dominant) nor controlling obese patients (dominant and reserved) present eating disorders. The analyzing obese patients (reserved and consenting) are reticent when it comes to consulting (18%) since they distrust others. Analyzing obese patients present an interpersonal distrust and an interoceptive awareness. The group which presents most eating disorders is that of facilitating obese patients (consenting and expansive). These present eating disorders of the compulsive types favored by interoceptive awareness, body dissatisfaction, ineffectiveness, and maturity fears. The diversity, even the absence, of eating disorders brought to evidence by our tests based upon different personality types should allow better understanding of the psychological and behavioral causes of weight gain and the means for improving compliance in the following of an obese patient.

[Male infertility caused by bilateral agenesis of the vas deferens: a new clinical form of cystic fibrosis?]

Congenital bilateral absence of vas deferens causes male excretory infertility and represents 1 to 2% of male infertility. Because of a genotypic similarity with cystic fibrosis, the possible in vitro fertilization with epididymal sperm requires careful genetic counselling. We studied genotype, sweat chloride concentration, respiratory function tests, sinus abnormalities, pancreatic and hepatic functions in 22 subjects with congenital bilateral absence of vas deferens. Among them, four were compound heterozygotus, all of them with the R117H mutation. Ten had a positive sweat test, one of them also being compound heterozygotus. Congenital bilateral absence of vas deferens and double mutation or positive sweat test led to high probable cystic fibrosis diagnosis in 13 subjects. Six subjects were heterozygotus for one cystic fibrosis mutation, criterium which is not sufficient for cystic fibrosis diagnosis; five of them had sinus abnormalities, present in 11 of the 22 subjects. Only three patients had no mutation nor sweat chloride abnormalities. This work confirms the high frequency of cystic fibrosis mutations in males with congenital bilateral absence of vas deferens, with a higher frequency of positive sweat test than in other publications, and a high frequency of sinus abnormalities. This monosymptomatic phenotype of cystic fibrosis suggests new hypotheses for a relationship between genotype and phenotype.

Aerosol administration of a recombinant adenovirus expressing CFTR to cystic fibrosis patients: a phase I clinical trial

Ad CFTR, a replication-deficient adenovirus expressing the human cystic fibrosis transmembrane conductance regulator (CFTR), was administered by aerosolization in a single escalating dose to three pairs (cohorts) of cystic fibrosis (CF) patients. Buffer only was administered to the nose and lungs 9-14 days before nasal instillation of virus followed the day after by aerosolization of Ad CFTR to the lung. Nasal doses (defined in terms of viral plaque forming units, pfu) were 10(5), 10(7), and 4 x 10(8), whereas aerosolized doses were 10(7), 10(8), 5.4 x 10(8) for each cohort, respectively. No acute toxic effects were observed in the first 4 weeks after virus treatment. Shedding of infectious Ad CFTR was never detected, whereas detection of vector DNA sequences and CFTR expression demonstrated DNA transfer to the nose and airways of patients. No significant deviations in immunological and inflammatory parameters were observed in serum and in bronchoalveolar lavage (BAL). Importantly, for all patients, the serum anti-adenovirus antibody levels did not change significantly from baseline and no antibodies against adenovirus were found in BAL.

Structure-function relationships of 3 beta-hydroxysteroid dehydrogenase: contribution made by the molecular genetics of 3 beta-hydroxysteroid dehydrogenase deficiency

The transformation of delta 5-3 beta-hydroxysteroids into the corresponding delta 4-3-keto-steroids is an essential step for the biosynthesis of all classes of active steroids: progesterone, mineralocorticoids, glucocorticoids, androgens, and estrogens. These steroid hormones play a crucial role in the differentiation, development, growth, and physiological function of most human tissues. The structures of several cDNAs encoding 3 beta-HSD isoenzymes have been characterized in human and several other vertebrate species: human types I and II; macaque; bovine; rat types I, II, III, and IV; mouse types I, II, III, IV, V and VI; hamster types I, II, and III; and rainbow trout. Their transient expression reveals that 3 beta-HSD and delta 5-delta 4-isomerase activities reside within a single protein. Distinct approaches have been used for a better understanding of the structure-function relationships of these 3 beta-HSD enzymes: i) affinity radiolabeling studies of the human type I 3 beta-HSD; ii) identification and the functional consequences of the human type-II 3 beta-HSD mutations detected in patients with 3 beta-HSD deficiency. Taken together, all of these data were examined to determine whether the relationship between the genotype and the phenotype of these patients were consistent with in vitro mutagenesis studies. 3 beta-HSD deficiency, transmitted in an autosomic recessive disorder, is characterized by varying degrees of salt wasting; in genetic males, fetal testicular 3 beta-HSD deficiency causes an undervirilized male genitalia (male pseudohermaphroditism); females exhibit either normal sexual differentiation or mild virilization. All mutations were detected in the type II 3 beta-HSD gene, which is expressed almost exclusively in the adrenals and gonads. No mutation was detected in the type I 3 beta-HSD gene, which is expressed in peripheral tissues. The finding of a normal type I 3 beta-HSD gene explains the elevated delta 5-steroids and mild virilization of affected girls at birth. To date, 24 mutations have been identified in 25 distinct families with 3 beta-HSD deficiencies. All nonsense and frameshift mutations introducing a premature termination codon were associated with the classical salt-losing form. The locations of these nonsense mutations suggest that at least the first 318 amino acids out of 371 are required for 3 beta-HSD activity. The consequences of the missense mutations on some domains of the 3 beta-enzyme, such as membrane-spanning domains, cofactor-binding site, and steroid-binding site, were reviewed. The future crystallization of the overexpressed normal and mutant-type II-3 beta-HSD enzymes should contribute to a better understanding of the structure-function relationships of this enzyme, especially for missense mutations located outside the putative functional regions.

[Dietary approach to obesity]

Dietetic treatment of overweight has its limits in cases with morbid obesity (BMI > 40 kg/m2) or with disturbed eating habits (compulsive eating). In these cases surgery and cognitive treatment may play a role. Dietetic treatment is often sufficient in patients with moderate to severe overweight (BMI > 27 to 39 kg/m3). This includes in the first place identification of bad habits by evaluation of nutritional behaviour over 3 or 7 days. The most frequent mistakes are the jumping of a meal (mostly breakfast) and nibbling of snacks rich in fat between meals and omission of hypocaloric and voluminous food like fruit and vegetables. The lacking sensation of saturation which is fostered by rapid and automatic food intake, may also contribute to the maintenance of overweight. The first dietetic rules to be observed consist in a regular schedule for meals and-if necessary-snacks in between and the selection of a lipid-poor diet with particular attention to hidden fat. The meal should be turned into an enjoyable experience whenever possible without other concurrent activities.

[Diet treatment of obesity--weight-loss stage and weight-maintenance stage]

Dietetic treatment of obesity occurs in two phases one of weight reduction and one of stabilisation of the reduced weight. Results of the first phase are marked mainly by reduction of calories (quantitative aspect) and not by the carbohydrate or fat content of the diet (qualitative aspect). This improves assessment of individual nutritional preferences and sustains the patients motivation longer. Current recommendations propose less restrictive diets, i.e. 500 Kcal less than the daily allowance. In the second phase of stabilisation a diet rich in complete carbohydrates (> 50 of daily calories) and poor in lipids (< 30%) regulates metabolism, appetite sencurion of saturation and thermogenesis favorably. Such a diet seems to permit a prolonged stabilisation of weight, an important criterion for successful treatment of obesity. A diet rich in carbohydrates and poor in lipids symbolized by a nutritional pyramid is at the same time the basis for actual recommendations for the entire population.

[Association of mixed gonadal dysgenesis and non-classic 21-hydroxylase deficiency]

BACKGROUND

The rare association of mixed gonadal dysgenesis and non classical congenital hyperplasia by 21-hydroxylase deficiency poses the problem of their respective responsibility in the development of sexual ambiguity.

CASE REPORT

In a newborn with ambiguous genitalia, blood 17-OH progesterone was moderately elevated (3.9 to 14.1 ng/mL) leading to the diagnosis of non-classical 21 hydroxylase deficiency, Molecular studies later confirmed this diagnosis. However, the presence of a palpable gonad and the karyotype (45 X/46 XY mosaicism) indicated a mixed gonadal dysgenesis as the cause of sexual ambiguity. Histological examination revealed the presence of a testis and a streak gonad.

CONCLUSION

This observation emphasizes the need for a complete clinical and biological analysis in all newborns with sexual ambiguity.