Retarding Effect of Hemp Hurd Lixiviates on the Hydration of Hydraulic and CSA Cements

Wood wool panels are widely used in the construction industry as sustainable cementitious composites, but there is a growing need to replace traditional Portland cement with a binder that has a lower embodied carbon footprint. In addition, the sustainability of these panels may face serious impediments if the required amount of wood for their production needs a harvest rate higher than the rate at which the tree sources reach maturity. One solution is to use the wooden part of fast-growing plants such as hemp. However, the compounds extracted from the mixture of plants and water are the main cause of the delay observed during the hydration process of hydraulic binders in these cementitious composites. The objective of this study is to evaluate the effect of bio-aggregate lixiviates (hemp hurd) on the hydration kinetics of calcium sulfoaluminate (CSA) cement as a low-embodied-carbon alternative to ordinary Portland cement (OPC). The isothermal calorimeter showed that the hemp hurd lixiviate caused a greater delay in GU's hydration process than CSA's. At a 5% concentration, the main hydration peak for GU cement emerged after 91 h, whereas for CSA cement, it appeared much earlier, at 2.5 h. XRD and TGA analysis showed that after 12 h of hydration, hydration products such as calcium silicate hydrates (C-S-H) and portlandite (CH) were not able to form on GU cement, indicating low hydration of silicate products. Moreover, at 5% concentration, the carbonation of ettringite was observed in CSA cement. The compressive strength values obtained from the mixes containing hemp hurd lixiviate consistently showed lower values compared to the reference samples prepared with distilled water. Furthermore, the CSA samples demonstrated superior compressive strength when compared to the GU samples. After 28 days of hydration, the compressive strength values for CSA cement were 36.7%, 63.5% and 71% higher than GU cement at a concentration of 0.5%, 2% and 5% hemp hurd lixiviate, respectively.

Efficacy of trabectedin in malignant solitary fibrous tumors: a retrospective analysis from the French Sarcoma Group

Background

Advanced malignant solitary fibrous tumors (SFTs) are rare soft-tissue sarcomas with a poor prognosis. Several treatment options have been reported, but with uncertain rates of efficacy. Our aim is to describe the activity of trabectedin in a retrospective, multi-center French series of patients with SFTs.

Methods

Patients were mainly identified through the French RetrospectYon database and were treated between January 2008 and May 2013. Trabectedin was administered at an initial dose of 1.5 mg/m², q3 weeks. The best tumor response was assessed according to the Response Evaluation Criteria In Solid Tumors 1.1. The Kaplan–Meier method was used to estimate median progression-free survival (PFS) and overall survival (OS). The growth-modulation index (GMI) was defined as the ratio between the time to progression with trabectedin (TTP_n) and the TTP with the immediately prior line of treatment (TTP_n-1).

Results

Eleven patients treated with trabectedin for advanced SFT were identified. Trabectedin had been used as second-line treatment in 8 patients (72.7 %) and as at least third-line therapy in a further 3 (27.3 %). The best RECIST response was a partial response (PR) in one patient (9.1 %) and stable disease (SD) in eight patients (72.7 %). Disease-control rate (DCR = PR + SD) was 81.8 %. After a median follow-up of 29.2 months, the median PFS was 11.6 months (95 % CI = 2.0; 15.2 months) and the median OS was 22.3 months (95 % CI = 9.1 months; not reached). The median GMI was 1.49 (range: 0.11–4.12).

Conclusion

Trabectedin is a very promising treatment for advanced SFTs. Further investigations are needed.

In situ synthesis and characterization of silver/polymer nanocomposites by thermal cationic polymerization processes at room temperature: initiating systems based on organosilanes and starch nanocrystals

New methods for the preparation of silver nanoparticles/polymer nanocomposite materials by thermal cationic polymerization of ε-caprolactone (ε-CL) or α-pinene oxide (α-PO) at room temperature (RT) and under air were developed. The new initiating systems were based on silanes (Si), starch nanocrystals (StN) and metal salts. Excellent polymerization profiles were revealed. It was shown that silver nanoparticles (Ag(0) NPs) were in situ formed and that the addition of StN improves the polymerization efficiency. The as-synthesized nanocomposite materials contained spherical nanoparticles homogeneously dispersed in the polymer matrices. Polymers and nanoparticles were characterized by gel permeation chromatography (GPC), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-vis spectroscopy. A coherent picture of the involved chemical mechanisms is presented.

A portable heat flux sensor

Nowadays monitoring physiological signals in real situations is essential to get the best diagnosis on patients. In this study we focus on the heat flux generated by the human body. We are developing a portable heat flux sensor using specific thermal materials.

Sarcoma: concordance between initial diagnosis and centralized expert review in a population-based study within three European regions

BACKGROUND

Sarcomas represent a heterogeneous group of tumors. Accurate determination of histological diagnosis and prognostic factors is critical for the delineation of treatment strategies. The contribution of second opinion (SO) to improve diagnostic accuracy has been suggested for sarcoma but has never been established in population-based studies.

METHODS

Histological data of patients diagnosed with sarcoma in Rhone-Alpes (France), Veneto (Italy) and Aquitaine (France) over a 2-year period were collected. Initial diagnoses were systematically compared with SO from regional and national experts.

RESULTS

Of 2016 selected patients, 1463 (73%) matched the inclusion criteria and were analyzed. Full concordance between primary diagnosis and SO (the first pathologist and the expert reached identical conclusions) was observed in 824 (56%) cases, partial concordance (identical diagnosis of connective tumor but different grade or histological subtype) in 518 (35%) cases and complete discordance (benign versus malignant, different histological type or invalidation of the diagnosis of sarcoma) in 121 (8%) cases. The major discrepancies were related to histological grade (n = 274, 43%), histological type (n = 144, 24%), subtype (n = 18, 3%) and grade plus subtype or grade plus histological type (n = 178, 29%).

CONCLUSION

More than 40% of first histological diagnoses were modified at second reading, possibly resulting in different treatment decisions.

Nanopore detection of single molecule RNAP-DNA transcription complex

In the past decade, a number of single-molecule methods have been developed with the aim of investigating single protein and nucleic acid interactions. For the first time we use solid-state nanopore sensing to detect a single E. coli RNAP-DNA transcription complex and single E. coli RNAP enzyme. On the basis of their specific conductance translocation signature, we can discriminate and identify between those two types of molecular translocations and translocations of bare DNA. This opens up a new perspectives for investigating transcription processes at the single-molecule level.

A recombinant rubella virus E1 glycoprotein as a rubella vaccine candidate

A recombinant rubella virus E1 (rE1) glycoprotein was produced and some of its chemical and immunological features were characterized. Two animal models were then used to establish that the rE1 glycoprotein and rubella virus particles shared antigenic and immunogenic properties. In the first one, sera from rE1 glycoprotein-immunized BALB/c mice neutralized in vitro rubella virus infection. In the second model, severe combined immune deficient (SCID) mice implanted with tonsil fragments from rubella immune donors and immunized with rE1 glycoprotein produced human anti-rubella virus antibodies. Altogether, these results showed that immunization with rE1 glycoprotein elicited neutralizing anti-rubella virus antibodies. This study thus indicated that the rE1 glycoprotein could constitute a non-replicating rubella vaccine.

Influence of SHBG gene pentanucleotide TAAAA repeat and D327N polymorphism on serum sex hormone-binding globulin concentration in hirsute women

SHBG is the specific plasma transport protein for sex steroid hormones in humans. Plasma SHBG concentration follows a gender dimorphism but varies with nutritional and hormonal status in both sexes. In addition, a genetic influence on SHBG in humans has recently been suggested by family studies. We investigated the relationship between a point mutation (D327N) in SHBG gene exon 8 that delays human SHBG half-life and a pentanucleotide repeat polymorphism [PNRP (TAAAA)(n)] in the SHBG gene 5' untranslated region that influences transcription in vitro, on the one hand, and SHBG levels on the other, in a population of 303 women referred for hirsutism. Of these patients, 154 (51%) met the criteria for polycystic ovary syndrome (PCOS) and 124 (41%) were overweight [body mass index (BMI) > or = 25 kg/m(2)]. The two SHBG gene alleles for D327N substitution, wild-type (W) and variant (v), were identified by restriction fragment length polymorphism in the whole population, and the GeneScan method was used to identify PNRP alleles in 245 subjects. Six alleles of the pentanucleotide motif with six to 11 repeats were present in our population. Plasma SHBG concentration was related to PCOS status, non-SHBG-bound testosterone, BMI, fasting blood glucose level, fasting insulinemia, and D327N allele v. The v allele was associated with higher SHBG levels [36.9 +/- 15.9 nmol/liter for W/v (n = 52) and 43.5 +/- 3.5 nmol/liter for v/v (n = 2)] than was the wild-type W allele [31.1 +/- 16.1 nmol/liter (n = 249); P = 0.039]. Multivariate analysis showed that BMI, PCOS status, and D327N polymorphism influenced plasma SHBG concentrations, each of these parameters contributing independently of the others. Investigating the role of each allele of the TAAAA repeat polymorphism on SHBG levels was more complex because of the number of different genotypes (as many as 18 in our population) and the low frequency of some of them. Moreover, a strong disequilibrium linkage was found between D327N allele v and the eight-TAAAA repeat allele (P < 0.0001). This could mask the effect of the TAAAA repeat polymorphism on SHBG concentration in vivo. Nevertheless, SHBG levels in patients who were homozygous for six repeats (34.9 +/- 16.2 nmol/liter; n = 21) were significantly (P = 0.043) higher than in nine-repeat homozygous patients (21.5 +/- 13.0 nmol/liter; n = 8), and lay between the two for eight-repeat homozygous patients (28.5 +/- 15.8 nmol/liter; n = 44). Delineating the precise role of this PNRP polymorphism will need further investigation in a large healthy population. In summary, although BMI and PCOS status have a major influence on circulating SHBG levels in hirsute women, the present results support the notion that polymorphism(s) within the coding sequence and, potentially, in the regulatory sequence of the SHBG gene are associated with circulating SHBG levels and may represent part of the genetic background of sex steroid hormone activity in humans.

Glucose-to-insulin ratio rather than sex hormone-binding globulin and adiponectin levels is the best predictor of insulin resistance in nonobese women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), the main androgen disorder in women, has been suggested to be associated with a high risk of developing cardiovascular disease and type 2 diabetes. In many PCOS patients, overweight or central obesity is generally associated with increases in fasting insulin levels, insulin resistance, and glucose intolerance, and has been identified as a target for new therapeutic strategy, including early change in lifestyle. Early biochemical marker(s) for identifying at-risk patients will be useful for prevention studies. The main goal of the present study was to search for such tool(s). We investigated 16 nonobese PCOS women by performing euglycemic hyperinsulinemic clamp and measuring insulin levels during fasting and oral glucose tolerance test, as well as the serum concentrations of SHBG, leptin, and adiponectin, the newly identified adipose factors. Eight of the 16 patients had a steady-state glucose disposal rate less than 8.5 mg/kg.min, the lowest normal value for nonobese control women. These insulin-resistant patients had significant higher body mass index (BMI) and waist-to-hip ratio (WHR), and lower high-density lipoprotein cholesterol and SHBG levels. As expected, glucose disposal correlated negatively with BMI (P = 0.01), WHR (P = 0.01), and fasting insulin level (P = 0.003). On stepwise regression analysis, however, the glucose-to-insulin ratio (GIR) emerged as the strongest independent parameter to appraise insulin resistance (R(2) = 0.61). SHBG level correlated positively with GIR (P < 0.001) and negatively with BMI (P = 0.003) but did not correlate with either insulin response during the glucose tolerance test or plasma leptin and/or adiponectin levels. In contrast, BMI was the only independent predictive parameter of SHBG (P = 0.003, R(2) = 0.73). Interestingly, plasma adiponectin levels were positively associated with glucose disposal rate (P = 0.043) and negatively with WHR (P = 0.024), waist circumference being the best predictor of adiponectin level (P < 0.01). Leptin level correlated only with BMI (r = 0.62, P = 0.01). This study confirmed that insulin resistance, despite the lack of obesity as such, is clearly present in many PCOS women, and demonstrated that GIR is the best predictor for insulin resistance. It was also shown that adiponectin level is a good indicator of abdominal fat mass and is associated to insulin resistance. Finally, low SHBG levels in PCOS are intimately associated with BMI, suggesting that some signal(s) from the adipose tissue, independent of adiponectin and leptin, may regulate liver production of SHBG.

Antibiotic-associated diarrhoea and Clostridium difficile in the community

BACKGROUND

Clostridium difficile is the main cause of nosocomial infectious diarrhoea and the causative agent of antibiotic-associated colitis. The involvement of C. difficile infection in antibiotic-associated diarrhoea in the community is poorly documented.

METHODS

We studied prospectively 266 adult out-patients in the Paris (France) area who were prescribed a 5-10-day course of antimicrobial chemotherapy. Stools were screened for C. difficile before and 14 days after the start of treatment by standard culture, toxigenic culture and testing for the cytopathic effect of toxin B. Patients were requested to note daily stool frequency and consistency. Diarrhoea was defined as the passage of at least three loose stools per day.

RESULTS

Forty-six (17.5%) of the 262 assessable patients had diarrhoea during the study period. Diarrhoea was mild and self-limited in all patients, and lasted for only 1 day in 65.6% of cases. C. difficile was isolated before and after treatment from one patient, who did not develop diarrhoea. C. difficile was detected only on day 14 in 10 patients (3.8%). The isolate was toxin producing in seven patients. Four of these seven patients had mild self-limited diarrhoea. Toxin-producing C. difficile was isolated significantly more frequently from patients who had diarrhoea than from those who were diarrhoea free (8.7% vs. 1.4%, P = 0.02).

CONCLUSION

The acquisition of toxin-producing C. difficile appears to be frequent during antimicrobial chemotherapy in the community [estimated rate of 2700 (1150-5400) cases per 100 000 exposures to antibiotics]. However, C. difficile is not the main agent of mild antibiotic-associated diarrhoea in out-patients.

Human sex hormone-binding globulin variants associated with hyperandrogenism and ovarian dysfunction

The access of testosterone and estradiol to target tissues is regulated by sex hormone-binding globulin (SHBG) in human blood. Serum SHBG levels are low in patients with hyperandrogenism, especially in association with polycystic ovarian syndrome (PCOS) and in individuals at risk for diabetes and heart disease. Here, we identify SHBG coding region variations from a compound heterozygous patient who presented with severe hyperandrogenism during pregnancy. Serum SHBG levels in this patient measured 2 years after her pregnancy were exceptionally low, and her non-protein-bound testosterone concentrations greatly exceeded the normal reference range. A single-nucleotide polymorphism within the proband's maternally derived SHBG allele encodes a missense mutation, P156L, which allows for normal steroid ligand binding but causes abnormal glycosylation and inefficient secretion of SHBG. This polymorphism was identified in four other patients with either PCOS, ioiopathic hirsutism, or ovarian failure. The proband's paternal SHBG allele carries a single-nucleotide deletion within exon 8, producing a reading-frame shift within the codon for E326 and a premature termination codon. CHO cells transfected with a SHBG cDNA carrying this mutation fail to secrete the predicted truncated form of SHBG. To our knowledge, these are the first examples of human SHBG variants linked to hyperandrogenism and ovarian dysfunction.

MYOC mutation frequency in primary open-angle glaucoma patients from Western Switzerland

PURPOSE

To determine MYOC gene mutation frequency in patients with primary open-angle glaucoma (POAG) from Western Switzerland.

METHODS

A total of 117 unselected index patients with primary open-angle glaucoma were submitted to a full eye examination. DNA was extracted from blood and PCR amplicons of MYOC exon 3 were screened for mutations by single-strand conformation polymorphism (SSCP) analysis. Abnormal conformers were analyzed both by direct bidirectional sequencing and by enzymatic mutation detection (EMD) assay.

RESULTS

Ten occurrences of four different sequence changes were detected, including: 1) five times the same disease-causing mutation (Q368X) in five unrelated POAG patients and 2) three distinct polymorphisms in five patients. The patients carrying an MYOC mutant allele were characterized by a broad clinical variability in terms of age of onset (34-77 years) and highest intraocular pressure (IOP) values (23-47 mmHg).

CONCLUSIONS

A pathogenic MYOC mutation (Q368X) was identified in 4.27% (5/117) of the studied population from Western Switzerland, which corresponds to the highest frequency yet reported for this mutation.

Missense mutations in COL8A2, the gene encoding the alpha2 chain of type VIII collagen, cause two forms of corneal endothelial dystrophy

Corneal clarity is maintained by its endothelium, which functions abnormally in the endothelial dystrophies, leading to corneal opacification. This group of conditions includes Fuchs' endothelial dystrophy of the cornea (FECD), one of the commonest indications for corneal transplantation performed in developed countries, posterior polymorphous dystrophy (PPCD) and the congenital hereditary endothelial dystrophies (CHED). A genome-wide search of a three-generation family with early-onset FECD demonstrated significant linkage with D1S2830 (Z(max) = 3.72, theta = 0.0). Refinement of the critical region defined a 6-7 cM interval of chromosome 1p34.3-p32 within which lies the COL8A2 gene. This encodes the 703 amino acid alpha2 chain of type VIII collagen, a short-chain collagen which is a component of endothelial basement membranes and which represented a strong candidate gene. Analysis of its coding sequence defined a missense mutation (gln455lys) within the triple helical domain of the protein in this family. Mutation analysis in patients with FECD and PPCD demonstrated further missense substitutions in familial and sporadic cases of FECD as well as in a single family with PPCD. This is the first description of the molecular basis of any of the corneal endothelial dystrophies or of mutations in type VIII collagen in association with human disease. This suggests that the underlying pathogenesis of FECD and PPCD may be related to disturbance of the role of type VIII collagen in influencing the terminal differentiation of the neural crest derived corneal endothelial cell.

A novel highly informative polyA microsatellite on the telomeric side of the INK4a/ARF locus

The INK4a/ARF locus encodes two cell cycle-regulatory proteins, p16(INK4a)and p14(ARF). Inactivation of the p16(INK4a)(MTS1) tumor suppressor gene by mutations, promoter methylation or gene deletions is a common event in the development of many different human tumors. The present report describes a novel polyA mononucleotide repeat situated 7.2 kb on the telomeric side of the INK4a/ARF locus. This highly polymorphic microsatellite marker (heterozygote frequency: 0.78) proved to be efficient for p16 allele loss and microsatellite instability analyses in human colon cancer.

Fatal outcome in a female monozygotic twin with X-linked hypohydrotic ectodermal dysplasia (XLHED) due to a de novo t(X;9) translocation with probable disruption of the EDA gene

Ectodermal dysplasias are a group of congenital disorders with defective development of the epidermis and its appendages. X-linked hypohydrotic ectodermal dysplasia (XLHED; OMIM 305100) is the most common form of ectodermal dysplasia. We report on two monozygotic twin girls with XLHED due to a t(X;9) translocation causing a disruption of the EDA gene and non random inactivation of the normal X chromosome. One of the girls died unexpectedly at 2.5 years of age. Autopsy revealed that lack of normal tracheobronchial secretions leading to complete tracheal obstruction by mucous debris was the probable cause of death.

CONCLUSION

Morbidity and mortality of ectodermal dysplasias in infancy and early childhood can be significant. Early diagnosis by paediatricians is important and complications should be anticipated.

Molecular characterization of the deletion in retinoblastoma patients with 13q14 cytogenetic anomalies

We investigated the molecular deletions of twelve patients presenting with retinoblastoma and a cytogenetic abnormality including band 13q14. Dinucleotide markers spanning the complete chromosome 13 as well as two intragenic markers were analyzed in patients and their two parents. The deletion was considered confirmed when one heterozygous allele was missing, potential when a homozygous allele was observed in continuity with a clearly deleted allele, and noninformative when a homozygous allele was observed adjacent to a nondeleted region. The patients could be classified into three groups based on their cytogenetic abnormalities. In group 1, the cytogenetic deletion was restricted to band13q14 with confirmed or potential molecular deletions extending from D13S328 to D13S153. Although a possible common centromeric deletion breakpoint could exist for three of the patients and a common telomeric deletion breakpoint for two, the cytogenetic deletion was different for most of them. Group 2 included patients with a cytogenetic deletion extending up to 13q22. At the molecular level, the telomeric breakpoints were between the RB1 gene and D13S156. Here again, it is quite unlikely that a common telomeric breakpoint was responsible for the deletion. Group 3 consisted of special cases with either a paracentric inversion or a complex translocation. The cytogenetic abnormalities around 13q14 correlate with the molecular deletions that were observed in this study. Associated malformations cannot be easily predicted from the size of the deletions.

Postmenopause hormone treatment in women with NIDDM or impaired glucose tolerance: the MEDIA randomized clinical trial

OBJECTIVE

To assess the biological safety of four hormone replacement treatment (HRT) combinations in women with non insulin dependent diabetes mellitus (NIDDM) or impaired glucose tolerance (IGT).

SUBJECTS AND METHODS

Randomized, double-blind, placebo-controlled trial to analyze the variation of fibrinogen, factor VII, PAI1, and TG blood levels in women (n=99), with NIDDM or IGT, receiving a 3-month course of either oral oestradiol (1 or 2 mg) combined with Chlormadinone Acetate 5 mg, or transdermal oestradiol 50 microg/24 h in association with Norethisterone Acetate (11.2 or 22.4 mg), or placebo. Follow-up lasted 3 months.

RESULTS

Ninety nine patients, mean age 56 years (SD 5), mean diabetes duration 7 years (S.D. 7), mean glycated hemoglobin (7.3%) were enrolled. There was no significant difference between the groups for any of the primary hemostasis criteria (n=77). Triglycerides (TG) variation significantly differed between groups, P=0.01, from -21% in the large patch group, to +22% in the placebo group (n=82). Treatment administration routes did not significantly differ for any of the criteria. There was a significant difference in the total cholesterol variation between groups, from +8.7% in the placebo group to -10.8% in the oral 1 mg group (P=0.001).

CONCLUSION

The treatments had no highly deleterious effect in these patients with NIDDM or with IGT. Long-term trials can be performed with such patients, and an hormone treatment can be prescribed to relieve symptoms. Since these patients had a well-controlled NIDDM, results might be different in less well-controlled diabetes. The data do not support the hypothesis of an impaired oestrogen effect in patients with NIDDM.

Novel human corticosteroid-binding globulin variant with low cortisol-binding affinity

Corticosteroid-binding globulin (CBG) is the plasma transport protein that regulates the access of glucocorticoid hormones to target cells. Genetic deficiencies of CBG are rare, and only a single human CBG variant (Trancortin Leuven) has been related so far to decreased cortisol-binding affinity. We report here on a 43-yr-old woman, referred for chronic asthenia and hypotension, with repeatedly low morning serum cortisol levels (22-61 nmol/L; normal range, 204-546 nmol/L), normal plasma ACTH levels (38-49 pg/mL; normal, <50 pg/mL), and normal urinary cortisol (10-76 nmol/24 h; normal range, 10-105 nmol/24 h). An increased percent-free (dialysable fraction) serum cortisol (8.7-9.7%, normal range, 2.9-3.9%) suggested abnormal CBG binding activity. Indeed, she had a low serum CBG concentration (24 mg/L vs. 44+/-6 mg/L in normal women), and the affinity of her CBG for cortisol was decreased (association constant, Ka = 0.12 L/nmol vs. 0.82+/-0.29 L/nmol). In her immediate family members, the serum CBG concentration and cortisol-binding activity were normal in her husband, but the four living children had slightly lower serum CBG concentrations than the reference ranges for their pre- and postpubertal status. Measurements of cortisol distribution in undiluted serum indicated that an increase in the percentage of nonprotein-bound cortisol offsets the low cortisol levels to give approximately normal concentrations of free cortisol in serum. Direct sequencing of PCR-amplified exons encoding CBG revealed that the proband was homozygous for a polymorphism (GAC-AAC) in the codon for residue 367, which results in a Asp367-->Asn substitution. Her children were heterozygous for this polymorphism. When this nucleotide change was introduced into a normal human CBG complementary DNA, for expression in Chinese hamster ovary cells, Scatchard analysis demonstrated that the Asn367 substitution reduced the affinity of human CBG for cortisol by approximately 4-fold (Ka = 0.15 L/nmol), as compared to normal recombinant CBG (Ka = 0.66 L/nmol). These results suggest that Asp367 is an important determinant of CBG steroid-binding activity and that normal negative regulation of the hypothalamic-pituitary-adrenal axis is maintained by relatively normal serum-free cortisol concentrations, despite a marked reduction in the steroid-binding affinity of this novel human CBG variant, which we have designated as CBG-Lyon.

Sex hormone-binding globulin during puberty in normal and hyperandrogenic girls

Human sex hormone-binding globulin (SHBG) regulates the cellular bioavailability of SHBG-bound steroid hormones. Subtle decreases in plasma SHBG levels during puberty have a perceptible effect on the androgen-estrogen balance. This SHBG decrease is more pronounced in girls with premature pubarche who are at risk to develop functional ovarian hyperandrogenism as well as insulin resistance syndrome. Insulin is a potent inhibitor of SHBG production in the liver, and there is now evidence that SHBG is a marker of hyperinsulinemia and insulin resistance that can be associated in both obese and non-obese patients with polycystic ovary syndrome. Therefore, low SHBG could be a useful tool for identifying presymptomatic individuals with diabetes mellitus type 2 including those with androgen disorders.

Physical map of 17p13 and the genes adjacent to p53

Genetic lesions in the p53 tumor suppressor gene are the most frequently observed alterations in human cancers. Typically in tumors, one allele of the p53 gene is initially mutated, followed by deletion of the remaining wildtype allele. In human colon cancer, for example, approximately 70% of late stage tumors are hemizygous mutant p53. Since the precise gene environment surrounding the p53 gene is not known, the neighboring genes concomitantly lost with wildtype p53 deletion remain undetermined. A restriction enzyme map and clone array of 1.1 Mb surrounding the p53 gene were constructed using a combination of YAC, BAC, NotI linking, and NotI jumping clones. The resulting physical map and clone array include approximately 400 kb telomeric and 700 kb centromeric to the p53 gene. Sequence determination and analysis adjacent to NotI and AscI sites, indicative of CpG islands, allowed the rapid identification of numerous genes within the cloned region. Twenty-seven transcription units were identified, including 18 characterized genes. Limited analysis of primary human colon tumors, hemizygous for the p53 gene, indicates loss of the entire 1.1-Mb region upon deletion of wildtype p53.

[Fuchs' uveitic syndrome in a patient with ocular toxoplasmosis]

We report a case of Fuchs' uveitic syndrome associated with toxoplasmic chorioretinis scars, and a positive Desmonts' coefficient. This allows us to emphasize ocular toxoplasmosis as a main association to be searched for clinically. In the cases in which this association is found, it would be warranted, if a high level of specific antitoxoplasmic antibodies is demonstrated in aqueous humor, to consider toxoplasmosis as one of the potential etiopathogenic factors of the Fuchs' uveitic syndrome.

Influence of glycosylation on the clearance of recombinant human sex hormone-binding globulin from rabbit blood

Human sex hormone-binding globulin (hSHBG) is a plasma glycoprotein that binds sex steroids with high affinity. Variations in hSHBG glycosylation contribute to its electrophoretic microheterogeneity, but the functional significance of different SHBG glycoforms is unknown. Carbohydrates may influence the biological activities and half-lives of glycoproteins and we have examined how oligosaccharides at specific sites influence the plasma clearance of hSHBG in vivo. To accomplish this, fully-glycosylated hSHBG, or hSHBG mutants lacking specific oligosaccharides chains, were expressed in Chinese hamster ovary (CHO) cells and purified by immunoaffinity chromatography. The purified recombinant proteins were then biotinylated to study their plasma half-lives after intravenous injection into rabbits. When compared to hSHBG isolated from serum, recombinant hSHBG migrates with a slightly larger average molecular size during denaturing polyacrylamide gel electrophoresis. This is due to a greater proportion (33-39% vs. 3%) of more highly branched N-linked oligosaccharides on the recombinant proteins. When injected into rabbits, the disappearance of recombinant hSHBG showed two exponential components, as previously shown for natural hSHBG in the same animal model. The mean +/- S.E.M. plasma half-lives of recombinant hSHBG (t 1/2alpha 0.11+/-0.03 h and t 1/2beta 18.94+/-1.65 h) are shorter than previously measured for natural hSHBG (t 1/2alpha 3.43+/-0.72 h and t 1/2beta 38.18+/-7.22 h) and this is likely due to differences in the composition of their N-linked oligosaccharides. An O-linked chain at Thr7 does not influence the plasma clearance of hSHBG in the presence or absence of N-linked carbohydrates at Asn351 and Asn367. However, a 1.5-1.6 fold (p<0.03) increase in plasma half-life of variants lacking both N-glycosylation sites was observed and this is probably due to the fact these variants are not recognized by the asialoglycoprotein receptor-mediated clearance system. Removal of either N-glycosylation consensus site also increased (p<0.0001) the plasma half-life of hSHBG by 2.3 2.4 fold. Thus, the metabolic clearance of hSHBG appears to be determined by the number of N-linked oligosaccharides rather than their location.

A single EFEMP1 mutation associated with both Malattia Leventinese and Doyne honeycomb retinal dystrophy

Malattia Leventinese (ML) and Doyne honeycomb retinal dystrophy (DHRD) refer to two autosomal dominant diseases characterized by yellow-white deposits known as drusen that accumulate beneath the retinal pigment epithelium (RPE). Both loci were mapped to chromosome 2p16-21 (refs 5,6) and this genetic interval has been subsequently narrowed. The importance of these diseases is due in large part to their close phenotypic similarity to age-related macular degeneration (AMD), a disorder with a strong genetic component that accounts for approximately 50% of registered blindness in the Western world. Just as in ML and DHRD, the early hallmark of AMD is the presence of drusen. Here we use a combination of positional and candidate gene methods to identify a single non-conservative mutation (Arg345Trp) in the gene EFEMP1 (for EGF-containing fibrillin-like extracellular matrix protein 1) in all families studied. This change was not present in 477 control individuals or in 494 patients with age-related macular degeneration. Identification of this mutation may aid in the development of an animal model for drusen, as well as in the identification of other genes involved in human macular degeneration.

[Bilateral anterior acute ischemic optic neuropathy complicating optic nerve head drusen. Apropos of a case]

A case of bilateral Anterior Ischemic Optic Neuropathy (AION) which is related to buried optic nerve head drusen is presented. Such an etiology has rarely been described and is poorly-documented in the literature. This etiologic diagnosis is brought by the imaging techniques: fluorescein angiography, B-scan ultrasonography and computed tomography. The pathogenesis may be related to the compressive effects encountered in a small scleral canal. The other complications of optic nerve head drusen are described and their similar mechanisms discussed.

Human variant sex hormone-binding globulin (SHBG) with an additional carbohydrate chain has a reduced clearance rate in rabbit

Sex hormone-binding globulin (SHBG) is the specific plasma transport protein for sex steroid hormones in humans. Considerable variation in SHBG plasma concentration exists between individuals, irrespective of gender, body weight, or thyroid status. In the present work, the influence of carbohydrate chains on the half-life of human SHBG (hSHBG) was investigated using a rabbit model. A variant hSHBG, with a point mutation in exon 8 (GAC --> AAC) encoding an amino acid substitution (Asp327Asn), which introduces an additional consensus site for N-glycosylation, has recently been identified. This mutation suppresses a recognition site for the restriction enzyme Bbs-I, allowing the development of a simple restriction-fragments length polymorphism (RFLP) screening procedure. In a population of patients (272 female and 49 male) consulting in our Endocrinology Clinic, 48 patients (41 female and 7 male) were heterozygous for the variant hSHBG allele and 3 (2 female and 1 male) were homozygous. In this population, the total variant allele frequency was 0.083. The hSHBG genotype, as determined by RFLP, corresponded in all cases to the phenotype as determined by the migration profile of hSHBG by Western blot analysis. The influence of such an additional glycosylation site on the biological half-life of variant hSHBG was investigated. SHBG from serum of patients carrying one of the three hSHBG genotypes was purified and labeled with biotin, then injected into rabbits, as we have recently described for rabbit SHBG. Biotinylated hSHBG was captured from rabbit serum samples on tubes coated with an anti-hSHBG antibody and detected by luminometry with the streptavidine-alkaline phosphatase-dioxetane (AMPPD) system. The results showed that the half-life value was significantly higher (P < 0.05) for SHBG purified from homozygous variant serum (t1/2 beta = 51.43 +/- 1.15 and 63.63 +/- 3.92 h, for male and a female subjects SHBG respectively) than for SHBG purified from heterozygous variant serum (t1/2 beta = 40.19 +/- 0.12 h) or wild-type (t1/2 beta = 38.18 +/- 7.22 h). This study demonstrated that an additional carbohydrate chain on hSHBG decreases the clearance rate of this protein. The low frequency of this variant allele means that further study will be required to determine whether it is associated with higher serum SHBG concentration.

Interrelations between sex hormone-binding globulin (SHBG), plasma lipoproteins and cardiovascular risk

The incidence of coronary artery disease is significantly higher in men than in women, at least until menopause. This gender difference could be explained by the action of sex steroids on the lipoprotein profile. In prepubertal children, high-density lipoprotein (HDL) cholesterol and triglyceride levels are similar between sexes, while adult men have generally lower HDL cholesterol and higher triglyceride levels than premenopausal adult women. Most cross-sectional studies have reported that sex hormone binding globulin (SHBG) and testosterone levels correlate positively with HDL cholesterol levels between sexes. Thus SHBG by modulating the balance in the biodisposal of testosterone and estradiol, might have a profound effect on the risk of cardiovascular disease. However, adjustment for body weight and body fat distribution weakens the association between SHBG, testosterone and HDL cholesterol. The negative correlation of fasting insulin with SHBG and HDL cholesterol levels in both sexes, and some evidence that insulin is an inhibitor of SHBG production in vitro, has suggested that hyperinsulinism might negatively regulate SHBG and HDL levels. It remains to be determined whether the inverse relationship between SHBG and insulin levels is coincidental or has a causal effect on the increase of atherosclerosis. Decreased SHBG has been shown to be predictive of the incidence of non-insulin-dependent diabetes mellitus in women but not in men, and of subsequent development of cardiovascular disease and overall mortality in postmenopausal women. SHBG is an index of androgenism in women and of insulin-resistance in both sexes, and might be useful in epidemiological studies of cardiovascular risk. However, in men, SHBG is not predictive of the occurrence of cardiovascular disease. Whether SHBG might have an intrinsic protective effect on the arterial wall through SHBG-receptors is still highly speculative.

Transient inhibition of angiotensinogen production in transgenic mice bearing an antisense angiotensinogen gene

Angiotensinogen is the precursor of the biologically active hormone angiotensin II. Enzyme kinetic parameters suggest that concentrations of plasma angiotensinogen are rate limiting in the renin reaction. It is therefore assumed that a decrease in angiotensinogen synthesis in vivo would result in a decrease in angiotensin II plasma levels and then of blood pressure. To test this hypothesis, we generated a transgenic mouse line that carries an inducible antisense angiotensinogen gene. Transient inhibition of angiotensinogen synthesis could be demonstrated in these transgenic animals. However, the amounts of liver angiotensinogen message and plasma angiotensinogen concentrations were rapidly back to levels observed in control animals.

[Acquired corticotropin insufficiency in adults. 2 new cases]

We report two new cases of isolated corticotropin deficiency, associated with TSH deficiency in one of the two patient. The diagnostic was made difficult because the symptoms were mainly psychiatric. Low plasmatic cortisol and ACTH level were found, with low T3, T4 and TSH in the second patient. The TSH did not respond to the stimulation by TRH. The cerebral tomodensitometry and magnetic resonance imaging focused on the sella turcica were normal, eliminated a tumor and showed an empty sella turcica. The patients have to be followed-up because an isolated deficiency may further complete to panhypopituitarism.

Calcifying pancreatitis of a congenital short pancreas: a case report with successful endoscopic papillotomy

We report a case of partial pancreatic agenesis in a 25-yr-old man with insulin-dependent diabetes who exhibited abdominal pains in relation to a calcifying chronic pancreatitis. An endoscopic retrograde pancreatography through the accessory papilla revealed an abnormal duct configuration thought to be consistent with an obstruction of the main duct. Ultrasonography and computerized tomography scanning could not identify any pancreatic tissue in the region of the body or tail. Another endoscopic investigation revealed the main papilla in the third part of the duodenum. The ducts of Santorini and Wirsung were identified. Santorini's duct was dilated and contained calculi. Wirsung's duct was nearly normal. The junction between the two ducts was slightly narrowed. After papillotomy of the accessory papilla, the patient's abdominal pains disappeared. This new case of congenital short pancreas is discussed in relation to four other cases reported in the English and French literature.