Mutation analysis in 600 French cystic fibrosis patients.

The cystic fibrosis transmembrane conductance regulator (CFTR) gene of 600 unrelated cystic fibrosis (CF) patients living in France (excluding Brittany) was screened for 105 different mutations. This analysis resulted in the identification of 86% of the CF alleles and complete genotyping of 76% of the patients. The most frequent mutations in this population after delta F508 (69% of the CF chromosomes) are G542X (3.3%), N1303K (1.8%), W1282X (1.5%), 1717-1G-->A (1.3%), 2184delA + 2183 A-->G (0.9%), and R553X (0.8%).     

Glycated hemoglobin in pregnancies at increased risk for gestational diabetes mellitus

Objective

The glycated hemoglobin (HbA_1c) value is increasingly used for the detection of (pre)diabetes, but HbA_1c decreases during pregnancy. We sought to identify clinical and metabolic correlates of HbA_1c in pregnancies at increased risk for gestational diabetes mellitus (GDM).

Study design

We prospectively studied 335 gravidas who received a 3-h 100 g oral glucose tolerance test (OGTT) at 24–32 weeks, in most cases after an abnormal glucose challenge test. Several indices of insulin sensitivity and secretion were computed from fasting measurements and the OGTT.

Results

HbA_1c concentrations gradually increased in diet-treated and insulin-treated GDM gravidas compared with non-GDM gravidas. HbA_1c was higher if the insulin peak was delayed until 180 min compared with 60 or 120 min. Stepwise regression identified the homeostasis modeling assessment of insulin resistance (HOMA-IR) as the first-rank correlate. Other correlates were ethnicity, a low insulin-to-glucose response at 60 min, and gestational age. The HbA_1c value corresponding to a fasting glucose of 5.1 mmol/l (diagnostic of GDM) was 2 mmol/mol (∼0.2%) higher if sampling occurred at 29–32 vs. 24–28 weeks or if ancestry was non-European vs. European.

Conclusion

HbA_1c is strongly associated with insulin resistance; in addition, HbA_1c captures the first-phase insulin response. However, HbA_1c varies with gestational age and ethnicity.     

Malleostapedotomy for otosclerosis,our experience of nitinol piston on twelve patients

ObjectiveMalleostapedotomy allows to completely by-pass the incus in otosclerosis surgery. Recently its use has been rivaled by hydroxyapatite cement for cases of mild and moderate necrosis of the incus. However, it remains gold standard for cases of extensive necrosis, incus dislocation, or epitympanic fixation. Modern heat-crimping pistons make surgery easier and safer. This study focuses on our experience with this technique.MethodsRetrospective analysis of patient’s files and pre- and post-operative audiograms, for cases of surgically treated otosclerosis with malleostapedotomy.ResultsTwelve patients underwent malleostapedotomy for otosclerosis between 2011 and 2019. Amongst them there were 10 revision surgeries and 2 primary cases. 75% had incus long-process necrosis, 17% had epitympanic fixation and one had a history of incus transposition. Nine patients (75%) had closure of air-bone gap (ABG) of <10 dB (p < 0.001) and 11 (92%) had a threshold of 20 dB (p < 0.001). Mean pre-operative ABG was 31 dB (15 dB–55 dB), and mean post-operative ABG was 7 dB (0 dB–21 dB; p < 0.001). There was no sensorineural hearing loss nor any other post-operative complication.ConclusionsMalleostapedotomy is a safe and reliable technique, allowing an ABG closure comparable to conventional incus to vestibule prosthesis. It remains the preferred technique whenever the incus cannot be used.     

Enamel and dental anomalies in latent‐transforming growth factor beta‐binding protein 3 mutant mice

Latent‐transforming growth factor beta‐binding protein 3 (LTBP‐3) is important for craniofacial morphogenesis and hard tissue mineralization, as it is essential for activation of transforming growth factor‐β (TGF‐β). To investigate the role of LTBP‐3 in tooth formation we performed micro‐computed tomography (micro‐CT), histology, and scanning electron microscopy analyses of adult Ltbp3‐/‐ mice. The Ltbp3‐/‐ mutants presented with unique craniofacial malformations and reductions in enamel formation that began at the matrix formation stage. Organization of maturation‐stage ameloblasts was severely disrupted. The lateral side of the incisor was affected most. Reduced enamel mineralization, modification of the enamel prism pattern, and enamel nodules were observed throughout the incisors, as revealed by scanning electron microscopy. Molar roots had internal irregular bulbous‐like formations. The cementum thickness was reduced, and microscopic dentinal tubules showed minor nanostructural changes. Thus, LTBP‐3 is required for ameloblast differentiation and for the formation of decussating enamel prisms, to prevent enamel nodule formation, and for proper root morphogenesis. Also, and consistent with the role of TGF‐β signaling during mineralization, almost all craniofacial bone components were affected in Ltbp3‐/‐ mice, especially those involving the upper jaw and snout. This mouse model demonstrates phenotypic overlap with Verloes Bourguignon syndrome, also caused by mutation of LTBP3, which is hallmarked by craniofacial anomalies and amelogenesis imperfecta phenotypes.     

High mortality due to congenital malformations in children aged &lt; 1 year in French Guiana

Background

In French Guiana, pregnant women may be exposed to infectious, environmental, and social risks leading to congenital malformation. The objective of the study was to study mortality rates from congenital malformations among infants <?1?year and to compare them with those in mainland France.

Methods

We used the CEPI DC (INSERM) database, which compiles annual data from death certificates in all French territories using the International Classification of Diseases. Annual deaths for French Guiana and mainland France between 2005 and 2015 were compiled. The age category studied was children less than 1?year and deaths from congenital malformations, deformations and chromosomal abnormalities were compiled. Crude risk ratios and 95% confidence intervals were calculated to quantify the excess risk of disease in French Guiana.

Results

In French Guiana between 2005 and 2015 there were 666 deaths of children aged <?1?year, among which, 132 (19.8%) were due to congenital malformations and chromosomal anomalies. Overall the risk ratio of death from congenital malformations and chromosomal anomalies between French Guiana and mainland France was 2.7 (1.5–4.7), P?<?0.001 for neurological congenital malformations it was 4.8 (1.2–19.7), P?=?0.01 and for congenital malformations of the circulatory system it was 3.3 (1.5–6.9), P?=?0.001.

Conclusions

The incidence of death from congenital malformations or chromosomal anomalies in French Guiana was significantly higher than in mainland France. Explanations for this may be infections, genetic causes, nutritional causes, and toxic causes that are prevalent. There is a need to identify factors that predispose children born in French Guiana to having a higher risk of congenital malformations and chromosomal anomalies.

     

Gastrointestinal colonization and systemic dissemination by Candida albicans and Candida tropicalis in intact and immunocompromised mice.

Gastrointestinal colonization and systemic dissemination by Candida albicans and Candida tropicalis were compared in intact and immunocompromised mice. Five-day-old CFW mice were inoculated by the oral-intragastric route with 1.0 x 10(7) CFU of two C. albicans and two C. tropicalis strains isolated from the blood of patients with acute leukemia and with C. albicans 4918 and its cerulenin-resistant mutant 4918-10. C. albicans and C. tropicalis spread to the lungs, liver, and kidneys within 30 min postinoculation, and organ CFU of the two species were comparable over the following 10 days. Close association of blastoconidia with the villous surface of the small intestine resulted in lysis of microvilli and then progressive invasion of villi. Blastoconidia within villi were surrounded by a conspicuous zone of clearing. Persistent colonization of the small and large intestines by C. albicans blood isolates and strains 4918 and 4918-10 was similar for 31 days after inoculation, but consistently exceeded that of C. tropicalis. In mice colonized with C. albicans, immunosuppression with cortisone acetate and cyclophosphamide on days 30 and 33 after inoculation increased stomach CFU 40- to 370-fold and intestinal CFU 30- to 80-fold. In contrast, persistent colonization by C. tropicalis was undetectable before immunosuppression and only became apparent after treatment. C. albicans disseminated more frequently and with higher organ CFU than C. tropicalis. Despite this fact, 20% of mice infected with C. tropicalis died, compared with 4% infected with C. albicans blood isolates. Indirect immunofluorescence revealed penetrative growth by Candida hyphae exclusively in the mucosa and submucosa of the stomach from immunosuppressed, persistently colonized mice. Taken together, the data indicate that C. tropicalis appears to be more virulent than C. albicans and that factors responsible for gastrointestinal colonization, systemic dissemination, and mortality in immunocompromised mice may not be identical.     

A new der(1;7)(q10;p10) leading to a singular 1p loss in a case of glioblastoma with oligodendroglioma component

The combined 1p‐/19q‐ deletions in oligodendrogliomas originate from translocation between both chromosomes. In the few cases of oligoastrocytomas and glioblastomas with an oligodendroglioma component (GBMO) where only 1p deletion was described, the origin remains unknown. We report the first case of GBMO, in which a single 1p deletion was detected and was linked to a translocation between chromosomes 1 and 7. Fresh surgical specimens were collected during surgery and the samples were used for cell culture, touch preparation smear slides (TP slides) and DNA extraction. Peripheral venous blood was also collected from the patient. G‐banding using Trypsin and stained with Giemsa (GTG) banding and karyotyping were performed and 1p‐/19q‐, TP53, PTEN and c‐MYC were analyzed by fluorescent in situ hybridization (FISH). Multicolor FISH (mFISH) and microsatellites analyses were also performed to complete the investigation. Three‐dimensional quantitative FISH (3D‐QFISH) of telomeres was performed on nuclei from TP slides and analyzed using TeloView^TM to determine whether the 3D telomere profile as an assessment of telomere dysfunction and a characterization of genomic instability could predict the disease aggressiveness. An unbalanced chromosomal translocation was found in all metaphases and confirmed by mFISH. The karyotype of the case is: 50～99,XXX, +der(1;7)(q10;p10),inc[47] The derivative chromosome was found in all 47 analyzed cells, but the number of derivatives varied from one to four. There was neither imbalance in copy number for genes TP53 and PTEN, nor amplification of c‐MYC gene. We did not find loss of heterozygosity with analysis of microsatellite markers for chromosomes 1p and 19q in tumor cells. The 3D‐telomere profile predicted a very poor prognostic and short‐term survival of the patient and highlights the potential clinical power of telomere signatures as a solid biomarker of GBMO. Furthermore, this translocation between chromosomes 1 and 7 led to a singular 1p deletion in this GBMO and may generate the 1p and 7q deletions.     

Early prenatal exposure to MPTP does not affect nigrostrial neurons in macaque monkey

The discovery of 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP), a toxin that induces parkinsonism in both human and primate, has prompted the search for environmental toxins potentially responsible for idiopathic Parkinson's disease (PD). The present study reports the ultimate effects of MPTP intoxication of a female macaque monkey, which unraveled to be pregnant after parkinsonism had developed, upon its fetus. Detailed examination of the offpsring nigrostriatal pathway showed that tyrosine hydroxylase immunoreactivity in caudate‐putamen nuclei and substantia nigra compacta (SNc) was not different from an age‐matched control. Biochemical analysis of the tissue content of dopaminergic markers further suggested modification of metabolism in the MPTP‐exposed monkey. These data suggest that early prenatal intoxication does not destroy nigrostriatal neurons, most likely because dopamine neurons had not developed yet when exposed to MPTP. Synapse 70:52–56, 2016. © 2015 Wiley Periodicals, Inc.