Localization of a novel X-linked congenital stationary night blindness locus: close linkage to the RP3 type retinitis pigmentosa gene region

X-linked congenital stationary night blindness (CSNBX) is anon-progressive retinal disorder characterized by decreasedvisual acuity and loss of night vision. CSNBX Is clinicallyheterogeneous with respect to the involvement of retinal rodsand/or cones in the disease. in this study, we localize a newlocus for CSNBX to Xp21.1, thus providing evidence that CSNBXis also genetically heterogeneous. A clear correlation betweendifferent genotypes and phenotypes cannot be found yet. Thenew CSNBX gene described here is closely linked to the X-linkedretinitis pigmentosa type 3 gene region, which supports thehypothesis that there may be a functional relationship betweencongenital stationary night blindness and retinitis pigmentosa.     

Cloning and functional characterization of a novel connexin expressed in somites of Xenopus laevis.

Connexin-containing gap junctions play an essential role in vertebrate development. More than 20 connexin isoforms have been identified in mammals. However, the number identified in Xenopus trails with only six isoforms described. Here, identification of a new connexin isoform from Xenopus laevis is described. Connexin40.4 was found by screening expressed sequence tag databases and carrying out polymerase chain reaction on genomic DNA. This new connexin has limited amino acid identity with mammalian (<50%) connexins, but conservation is higher (approximately 62%) with fish. During Xenopus laevis development, connexin40.4 was first expressed after the mid-blastula transition. There was prominent expression in the presomitic paraxial mesoderm and later in the developing somites. In adult frogs, expression was detected in kidney and stomach as well as in brain, heart, and skeletal muscle. Ectopic expression of connexin40.4 in HEK293 cells, resulted in formation of gap junction like structures at the cell interfaces. Similar ectopic expression in neural N2A cells resulted in functional electrical coupling, displaying mild, asymmetric voltage dependence. We thus cloned a novel connexin from Xenopus laevis, strongly expressed in developing somites, with no apparent orthologue in mammals.     

The Chinese hamster V79 cell mutant V-H4 is phenotypically like Fanconi anemia cells

It has been shown by genetic complementation analysis that a mitomycin C-sensitive mutant (V-H4) of Chinese hamster V79 cells is the first rodent equivalent of Fanconi anemia (FA) group A. The V-H4 mutant shows many typical characteristics of cells derived from FA patients. V-H4 cells exhibit increased sensitivity towards cross-linking agents as MMC (30-fold), cis-DDP (10-fold), DEB (10-fold), and PUVA (1.6-fold), but an only slightly increased sensitivity to monofunctional alkylating agents (EMS and MMS) and actinomycin D. V-H4 cells are also moderately sensitive to adriamycin (1.6-fold), and not sensitive to H₂O₂. The levels of chromosomal aberrations induced by MMC and cis-DDP treatment are higher (4- to 6-fold) in V-H4 cells than in the wild-type V79 cells. Genetic complementation analysis with other Chinese hamster mutants hypersensitive to MMC (irs1, irs1SF, UV20 and UV41) indicates clearly that V-H4 belongs to a different, new complementation group. This unique mutant is very stable and can serve as a vehicle to isolate the complementing FA-A gene from normal human DNA.     

Genetic diversity of mitomycin C-hypersensitive Chinese hamster cell mutants: A new complementation group with chromosomal instability

A Chinese hamster cell mutant (V-C8) isolated previously, which is 100 fold more sensitive to mitomycin C (MMC) than its parental wild-type V79 cells (judged by D₁₀ values), was further characterized. V-C8 cells exhibit an increased sensitivity towards other cross-linking agents, such ascis-DDP (40-fold), DEB (30-fold), and also to adriamycin (5-fold), and the monofunctional alkylating agents: MMS (5-fold) and EMS (6-fold). V-C8 cells show a higher level induction of chromosomal aberrations by cross-linking agents (MMC,cis-DDP, and DEB) and an increased level of spontaneous chromosomal aberrations in comparison to the wild-type V79 cells. To determine whether the V-C8 mutant represents a new complementation group among Chinese hamster cell mutants that also display the extreme sensitivity to MMC, V-C8 cells were fused withirs1, irs1SF, UV20, UV41, and V-H4 cells. In all cases, the derived hybrids regained the MMC sensitivity similar to wild-type cells, indicating that the V-C8 mutant belongs to a new sixth complementation group.     

Outpatient initiation of the ketogenic diet in children with pharmacoresistant epilepsy: An effectiveness,safety and economic perspective

BackgroundChildren with pharmacoresistant epilepsy usually receive ketogenic diet (KD) as an inpatient, which makes it an expensive treatment.ObjectiveTo compare the effectiveness, safety, and costs of outpatient versus inpatient initiated KD.DesignRetrospective observational non-inferiority study.Patients/settingPatients (1–18 years of age) who started KD either inpatient or outpatient.Main outcome measuresEffectiveness was defined as ≥50% seizure reduction. Safety was measured by the numbers of emergency visits and complications. Economic impact was analyzed by calculating total costs of treatment.Statistical analysesNon-inferiority of outpatient initiation was tested using 95% confidence intervals of the differences in effectiveness and safety endpoints between groups with non-inferiority margins of 10%. Nonparametric bootstrap techniques were used to derive a 95% confidence interval for the mean difference in total costs between the groups.ResultsHundred and five patients started KD in the period 2001 to 2017: 43 inpatient and 62 outpatient. At three months, the KD was effective in 61% of outpatients versus 63% of inpatients. The KD was considered safe in 36% of the outpatients, as compared to 29% in the inpatients. Outpatient initiation was shown to be non-inferior to inpatient initiation in terms of safety. Total health care costs of outpatient initiation were € 2901, as compared to € 8195 of inpatient initiation per patient (mean difference € 5294, 95% CI; -€ 7653 to -€ 2935).ConclusionsOur study suggests that outpatient KD initiation is no worse than inpatient initiation in terms of effectiveness and safety, while carrying lower health care costs.     

Exposure to secondhand smoke and depression and anxiety: A report from two studies in the Netherlands

Objective

Previous population-based studies suggest that exposure to secondhand smoke (SHS) is related to increased depressive symptoms and poor mental health among non-smokers. We examined whether these associations could be replicated in two independent Dutch samples.

Methods

Non-smoking adults were selected from two studies: 1) the Netherlands Study of Depression and Anxiety (NESDA), comprising individuals with current and remitted depressive and/or anxiety disorders, and healthy controls and 2) the Netherlands Twin Register (NTR), comprising twin-family studies on health-related behaviors. In both studies, SHS exposure was assessed with plasma cotinine levels (1–14 ng/ml vs. < 1 ng/ml). In NESDA, outcomes were current depressive and/or anxiety disorders, and depression and anxiety symptom severity scores. In NTR, the Adult Self Report derived DSM-subscales for depressive and anxiety problems, and anxious depressive scores were analyzed.

Results

In NESDA non-smokers (n = 1757), increased plasma cotinine level (≥ 1 ng/ml) was not related to current depressive and/or anxiety disorders [odds ratio (OR) 0.96, P = .77], nor to depression or anxiety severity indicators. Similarly, in NTR non-smokers (n = 1088) cotinine levels ≥ 1 ng/ml were not associated with the DSM-subscale for depressive problems [unstandardized regression coefficient (B) 0.04, P = .88], nor to other depression and anxiety measures.

Conclusions

In non-smoking adults from patient and population samples, we found no evidence that plasma cotinine levels were related to either depressive and/or anxiety disorders, or to depressive and anxiety symptoms. This suggests that SHS exposure is not related to depression and anxiety in non-smoking adults.     

Zur Kenntnis der Glykogenkrankheit

Ohne Zusammenfassung     

First-line temozolomide chemotherapy in progressive low-grade astrocytomas after radiotherapy: molecular characteristics in relation to response

Only a few studies examined the effect of temozolomide (TMZ) in recurrent low-grade astrocytoma (LGA) after surgery, none of which included a homogeneous and sufficiently sized group of patients with progression after radiotherapy (RT). We evaluated a cohort of 58 patients treated with TMZ for progression after RT of a previous LGA and investigated the relation between outcome and mutations in the IDH1, IDH2, and TP53 genes, O⁶-methylguanine-methyltransferase (MGMT) promoter methylation, trisomy of chromosome 7, and loss of chromosomes 1p and 19q. All patients received first-line TMZ 200 mg/m²/day on days 1–5 every 4 weeks for a progressive LGA with a contrast-enhancing lesion on MRI after RT. Six months progression-free survival (PFS) was 67%, and the median overall survival was 14 months. An objective response was obtained in 54%. TP53 mutations and loss of chromosome 19q showed a borderline association with PFS, but none of the other molecular characteristics were correlated with the outcome to TMZ. Both a methylated MGMT promoter gene and IDH1 mutations were found in 86% of the tumor samples. A correlation was found between IDH1 mutations and MGMT promoter methylation (P < .001). Neither MGMT promoter methylation nor IDH1 mutations correlated with PFS, but the interval between the very first symptom of the LGA and the start of the TMZ was significantly longer in the patients with IDH1 mutations (P = .01) and a methylated MGMT promoter (P = .02). We conclude that MGMT promoter methylation and IDH1 mutations seem to predict survival from the time of diagnosis, but not PFS to TMZ.