X-inactivation of HSD17B10 revealed by cDNA analysis in two female patients with 17β-hydroxysteroid dehydrogenase 10 deficiency

17β-Hydroxysteroid dehydrogenase 10 (HSD10) is a mitochondrial enzyme involved in the degradation pathway of isoleucine and branched-chain fatty acids. The gene encoding HSD10, HSD17B10, has been reported as one of the few genes that escapes X-inactivation. We previously studied two female patients with HSD10 deficiency, one of them was severely affected and the other presented a mild phenotype. To elucidate as to why these two carriers were so differently affected, cDNA analyses were performed. The HSD17B10 cDNA of eight control cell lines, two hemizygous patients and two carriers was obtained from cultured fibroblasts, amplified by PCR and sequenced by standard methods. All HSD17B10 cDNAs were quantified by real-time PCR. In the fibroblasts of the female patient who presented with the severe phenotype, only the mutant allele was identified in the cDNA sequence, which was further confirmed by relative quantification (RQ) of HSD17B10 cDNA. This is in agreement with an unfavourable X-inactivation. The other female patient, with slight clinical affectation, showed the presence of both mutant and wild-type alleles in the cDNA sequence, which was confirmed by RQ of HSD17B10 cDNA in fibroblasts. This is in line with normal X-inactivation and the expression of both alleles in different cells (functional mosaicism). RQ results of HSD17B10 cDNA did not differ significantly between male and female controls, which indicate that the genetic doses of mRNA of HSD17B10 was the same in both sexes. In conclusion, these results suggest that the HSD17B10 gene does not escape X-inactivation as has been reported previously.     

Subtypes of memory dysfunction associated with ECT: characteristics and neurobiological bases.

Electroconvulsive therapy (ECT) is an effective treatment for a variety of psychiatric syndromes. However, one of its adverse secondary effects is neurocognitive dysfunction. The aim of this paper is to review different subtypes of memory dysfunction associated with ECT from a neuropsychological perspective. Declarative memory is clearly impaired after ECT. Immediate memory, however, is broadly preserved. Few studies have addressed procedural and incidental memory. Selective memory is impaired, probably due to the disruption of specific brain regions. Some of the possible neurobiological bases of ECT memory dysfunction are discussed in this paper. Synaptic plasticity, the cerebral neurotransmission system, and cerebral metabolism are examined in relation to the dysfunction and subsequent recovery of each memory subtype.     

Metformin therapy during puberty delays menarche, prolongs pubertal growth, and augments adult height: a randomized study in low-birth-weight girls with early-normal onset of puberty

CONTEXT AND OBJECTIVE: Low-birth-weight (LBW) girls who enter puberty earlier (around 8-9 yr) tend to have earlier menarche, earlier growth arrest, and a shorter adult stature. At present, there is no therapy for most of these girls. In LBW girls with early puberty, hyperinsulinemic insulin resistance could underpin their rapid transit through puberty and their loss of adult stature. We explored the effects of insulin sensitization with metformin during puberty. SETTING, DESIGN, AND PATIENTS: In an open-labeled, prospective study, 22 LBW girls (birth weight < -1.5 sd score for gestational age) with early-normal puberty (stage 2 breast development at age 8-9 yr) were randomized to remain untreated (n = 12) or to receive metformin (850 mg/d; n = 10) for 36 months (mean age at start, 9.0 yr). All girls remained untreated between 36 and 42 months. MAIN OUTCOME MEASURES: Pubertal growth, body composition by absorptiometry, uterine-ovarian size by ultrasound, fasting insulin, glucose, lipids, leptin, IGF-I, and IGF-binding protein-1 were assessed. RESULTS: Metformin treatment resulted in a longer duration from stage 2 breast development to menarche (P < 0.01; median difference, +1.0 yr), taller near-adult height (P < 0.01), and leaner body composition (P < 0.001). Metformin was also associated with lower insulin resistance and leptin and IGF-I levels and higher SHBG and IGF-binding protein-1 levels and with a more favorable lipid profile. Bone mineral density and uterine-ovarian growth were unaffected. CONCLUSION: Metformin treatment for 36 months in LBW girls with early-normal puberty normalized their pubertal progression to menarche and increased height gains up to adult stature. These data support the concept that insulin is a major codeterminant of the pubertal tempo and pubertal height gain in girls.     

Adenosine A2A receptors are expressed in human atrial myocytes and modulate spontaneous sarcoplasmic reticulum calcium release

BACKGROUND: Alterations in the cyclic AMP-dependent regulation of the cardiac ryanodine receptor (RyR2) have been proposed to account for increased spontaneous calcium release from the sarcoplasmic reticulum (SR) in patients with heart failure, ventricular tachyarrhythmias and atrial fibrillation. While the adenosine A(2A) receptor (A(2A)R) is known to regulate cyclic AMP levels, expression and function of this receptor in human cardiac myocytes has not been investigated. METHODS: PCR, western blotting and immunofluorescence were used to identify the A(2A)R, and functional effects of A(2A)R stimulation were measured with confocal calcium imaging and patch-clamp technique. RESULTS: The A(2A)R is expressed in the human right atrium and distributed in a banded pattern along the Z-lines, overlapping with the ryanodine receptor. A(2A)R stimulation caused a protein kinase A dependent increase in spontaneous SR calcium release in isolated human atrial myocytes. The A(2A)R agonist CGS21680 increased the frequency of calcium sparks from 0.12+/-0.03 to 0.31+/-0.08 sparks.mum min(-1) (p<0.05) and calcium waves from 0.65+/-0.31 to 5.11+/-1.84 waves.min(-1) (p<0.03). Moreover, spontaneous Na-Ca exchange currents (I(NCX)) increased from 1.19+/-0.17 to 2.50+/-0.42 min(-1) (p<0.001). In contrast, CGS21680 did not alter caffeine inducible calcium release (6.98+/-0.52 vs. 6.82+/-0.57 amol pF(-1), p=0.6) or the spontaneous I(NCX) amplitude (0.32+/-0.05 vs. 0.29+/-0.04 pA pF(-1), p=0.2). Current-voltage relationship and amplitude of the L-type calcium current (1.62+/-0.18 vs. 1.80+/-0.18 pA pF(-1)) were not altered, but calcium release dependent inactivation was faster with CGS21680 (13.4+/-0.7 vs. 15.8+/-1.0 ms, p<0.001). CONCLUSIONS: Adenosine A(2A) receptors are expressed in the human atrial myocardium and modulate the frequency of spontaneous calcium release from the SR.     

Common variants in NLRP2 and NLRP3 genes are strong prognostic factors for the outcome of HLA-identical sibling allogeneic stem cell transplantation

The inflammasomes are macromolecular cytosolic complexes involved in the production of interleukin-1beta (IL-1beta) and IL-18 in response to several pathogen-derived stimuli. Such interleukins have been implicated in the origin of severe allogeneic stem cell transplant (allo-SCT) complications. We analyzed the relationship between the interindividual variability in inflammasome protein-encoding genes in donors and patients and clinical outcome after allo-SCT. Fourteen common genetic variants in 5 genes of the inflammasome, namely, NLRP1, NLRP2, NLRP3, CARD8, and CASP5, were genotyped in 133 human leukocyte antigen-identical sibling pairs undergoing allo-SCT. In the multivariate analysis, donor variants in NLRP2 and NLRP3 were the most important prognostic factors for the clinical outcome after allo-SCT. Thus, donor TT genotype at rs10925027 in NLRP3 was associated with disease relapse (odds ratio (OR) = 6.3, P = 1 x 10(-7)), and donor GG genotype at rs1043684 in NLRP2 was associated with nonrelapse mortality (OR = 4.4, P = 6 x 10(-4)) and overall survival (OR = 3.1, P = .001). In addition, patient AA genotype at rs5862 in NLRP1 was associated with nonrelapse mortality (OR = 2.8, P = .005) and overall survival (OR = 2.0, P = .009). These results suggest that inflammasome genetic variants are important prognostic factors for the outcome of allo-SCT. If validated in larger studies, including unrelated allo-SCT, NLRPs genotype would become an important factor in donor selection.     

Islet abnormalities in the pathogenesis of autoimmune diabetes.

Type 1 diabetes mellitus is a T-cell-mediated autoimmune disease that results in the destruction of the insulin-producing beta cells in the pancreatic islets of Langerhans. In spite of extensive genetic and immunological studies, mainly performed in the non-obese diabetic (NOD) spontaneous mouse model, the etiology of the autoimmune attack remains unknown. Several autoantigens have been identified and numerous studies have suggested a role for defective regulation of immune function. However, this account does not explain why the autoimmune process specifically affects the insulin-producing beta cells. Thus, abnormal immune regulation might explain the predisposition to autoimmunity in general, but additional factors should then determine the target of the autoimmune attack. Here, we review the evidence that abnormalities in islet cell differentiation and function exist that might trigger the immune system towards beta-cell autoimmunity in humans and NOD mice.     

Hypersecretion of FSH in infant boys and girls born small for gestational age

Prenatal growth restraint, as reflected in a low birthweight for gestational age, is a risk factor for postpubertal FSH hypersecretion and for reduced gonadal size. The ontogeny of the low-birthweight effect on the FSH-inhibin B feedback loop is unknown. Infancy is an episode of choice to study the possibility of an early low-birthweight effect on the FSH-inhibin B loop because this phase is characterized by high activity within the gonadal axis. We assessed serum concentrations of FSH and inhibin B in 46 infants [26 girls and 20 boys; mean age, 4 months; range, 3-6 months; 17 appropriate for gestational age (AGA), 29 small for gestational age (SGA); mean birthweight, 3.2 kg for AGA vs. 2.3 kg for SGA], together with circulating levels of LH, E2, and free androgen index. In SGA girls and boys, serum FSH levels were 2- and 4-fold higher (P < 0.001), respectively, than in AGA controls of the same gender (7.3 +/- 0.9 vs. 3.8 +/- 0.4 IU/ml and 2.9 +/- 0.5 vs. 0.7 +/- 0.2 IU/ml). Serum LH, inhibin B, and free androgen index/E2 concentrations were similar in AGA and SGA infants. In conclusion, prenatal growth restraint was found to be followed by elevated serum FSH concentrations in infant girls and boys. SGA infants seem to need an augmented FSH drive to fulfill inhibin B requirements on the afferent side of the feedback loop. The late-endocrine correlates of early growth restraint are herewith extended to include the main axis of reproduction in both genders. It remains to be studied whether FSH hypersecretion in infancy is a marker of subsequent subfertility.     

Inflammatory bowel disease in travelers: choosing the right vaccines and check-ups

The majority of patients with inflammatory bowel disease (IBD) achieve good control of the inflammatory activity using available therapies. When remission is achieved and quality of life recovered, a considerable proportion of IBD patients express their desire to travel abroad, be it for business, academic or leisure purposes. Their physicians should help and encourage them whenever possible. However, preventive measures are warranted to minimize the risk, since IBD patients are exposed to the same infectio...