Reversal of startle gating deficits in transgenic mice overexpressing corticotropin-releasing factor by antipsychotic drugs.

Chronically elevated levels of corticotropin-releasing factor (CRF) in transgenic mice overexpressing CRF in the brain (CRF-OE) appear to be associated with alterations commonly associated with major depressive disorder, as well as with sensorimotor gating deficits commonly associated with schizophrenia. In the present study, we tested the hypothesis that antipsychotics may be effective in normalizing prepulse inhibition (PPI) of acoustic startle in CRF-OE mice, which display impaired sensorimotor gating compared to wild-type (WT) mice. The typical antipsychotic haloperidol and atypical antipsychotic risperidone improved PPI in the CRF-OE mice, but were ineffective in WT mice. The atypical antipsychotic clozapine did not influence PPI in CRF-OE mice, but reduced gating in WT mice. This effect of clozapine in the CRF-OE mice may thus be regarded as a relative improvement, consistent with the observed effect of haloperidol and risperidone. As expected, the anxiolytic, nonantipsychotic chlordiazepoxide was devoid of any effect. All four compounds dose-dependently reduced the acoustic startle response irrespective of genotype. These results indicate that antipsychotic drugs are effective in improving startle gating deficits in the CRF-OE mice. Hence, the CRF-OE mouse model may represent an animal model for certain aspects of psychotic depression, and could be a valuable tool for research addressing the impact of chronically elevated levels of CRF on information processing.     

Reductive activation and radical formation in a series of substituted benzoquinones: Thermodynamic and quantum chemical studies

The reduction of the quinone moiety, which is found in many anti-cancer agents, is still a poorly understood process. It is commonly assumed that the reduction of a quinone by the uptake of two electrons and two protons leads to the active hydroquinone form. For a better understanding of these reactions electrochemical data, obtained for a series of substituted benzoquinones, were analyzed. In addition quantum chemical calculations on the STO-3G level were performed to obtain data for the one- and two-electron reduction.From the electrochemical experiments, thermodynamic data can be obtained which show that the unfavourable free energy of electron uptake is overcome by the favourable binding of protons. Both reactions are influenced by the electronic properties of the substituents, as demonstrated by Hammett-type relationships between the free energy of these reactions and the sigma-para character of these substituents. In these relationships the reaction constant of the electron uptake process has an absolute value which is five times higher than that of the proton uptake.Quantum chemical calculations yielded energy values for the one-electron uptake, as expressed by U(LUMO), and for the total reduction process. Most of the results from these calculations are in accord with the thermodynamic study. The calculations also revealed a conformational change to take place upon reduction of NH₂ and N(CH₂)₂ substituted benzoquinones, which might be important for chemical and biological activity.     

Different Effect of Rho Kinase Inhibition on Calcium Signaling in Rat Isolated Large and Small Arteries

In addition to its role in the regulation of artery contraction, Rho kinase (ROCK) was reported to be involved in the cytosolic calcium response to vasoconstrictor agonists in rat aorta and superior mesenteric artery (SMA). However, it remains to be determined whether ROCK also contributes to calcium signaling in resistance arteries, which play a major role in blood pressure regulation. The investigation of the effect of ROCK inhibition on the calcium and contractile responses of rat resistance mesenteric artery (RMA), in comparison with aorta and SMA, indicated that the calcium response to noradrenaline was inhibited by the ROCK inhibitor Y-27632 in aorta and SMA but not in RMA. The effect of Y-27632 on the calcium signal was unaffected by cytochalasin-D. ROCK activation in noradrenaline-stimulated arteries was confirmed by the inhibition of myosin light chain phosphorylation by Y-27632. Moreover, noradrenaline-induced calcium signaling was similarly inhibited by nimodipine in aorta, SMA and RMA, but nimodipine sensitivity of the contraction increased from the aorta to the RMA, suggesting that the contraction was controlled by different sources of calcium. In pressurized RMA, Y-27632 and H-1152 depressed pressure-induced calcium responses and abolished myogenic contraction. These results stress the important differences in calcium signaling between conductance and resistance arteries.     

Interlaboratory Comparison of Sample Preparation Methods,Database Expansions,and Cutoff Values for Identification of Yeasts by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Using a Yeast Test Panel

An interlaboratory study using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) to determine the identification of clinically important yeasts (n = 35) was performed at 11 clinical centers, one company, and one reference center using the Bruker Daltonics MALDI Biotyper system. The optimal cutoff for the MALDI-TOF MS score was investigated using receiver operating characteristic (ROC) curve analyses. The percentages of correct identifications were compared for different sample preparation methods and different databases. Logistic regression analysis was performed to analyze the association between the number of spectra in the database and the percentage of strains that were correctly identified. A total of 5,460 MALDI-TOF MS results were obtained. Using all results, the area under the ROC curve was 0.95 (95% confidence interval [CI], 0.94 to 0.96). With a sensitivity of 0.84 and a specificity of 0.97, a cutoff value of 1.7 was considered optimal. The overall percentage of correct identifications (formic acid-ethanol extraction method, score ≥ 1.7) was 61.5% when the commercial Bruker Daltonics database (BDAL) was used, and it increased to 86.8% by using an extended BDAL supplemented with a Centraalbureau voor Schimmelcultures (CBS)-KNAW Fungal Biodiversity Centre in-house database (BDAL+CBS in-house). A greater number of main spectra (MSP) in the database was associated with a higher percentage of correct identifications (odds ratio [OR], 1.10; 95% CI, 1.05 to 1.15; P < 0.01). The results from the direct transfer method ranged from 0% to 82.9% correct identifications, with the results of the top four centers ranging from 71.4% to 82.9% correct identifications. This study supports the use of a cutoff value of 1.7 for the identification of yeasts using MALDI-TOF MS. The inclusion of enough isolates of the same species in the database can enhance the proportion of correctly identified strains. Further optimization of the preparation methods, especially of the direct transfer method, may contribute to improved diagnosis of yeast-related infections.     

Overexpression of corticotropin-releasing hormone in transgenic mice and chronic stress-like autonomic and physiological alterations

To gain a greater insight into the relationship between hyperactivity of the corticotropin-releasing hormone (CRH) system and autonomic and physiological changes associated with chronic stress, we developed a transgenic mouse model of central CRH overproduction. The extent of central and peripheral CRH overexpression, and the amount of bioactive CRH in the hypothalamus were determined in two lines of CRH-overexpressing (CRH-OE) mice. Furthermore, 24 h patterns of body temperature, heart rate, and activity were assessed using radiotelemetry, as well as cumulative water and food consumption and body weight gain over a 7-day period. CRH-OE mice showed increased amounts of CRH peptide and mRNA only in the central nervous system. Despite the presence of the same CRH transgene in their genome, only in one of the two established lines of CRH-OE mice (line 2122, but not 2123) was overexpression of CRH associated with increased levels of bioactive CRH in the hypothalamus, increased body temperature and heart rate (predominantly during the light (inactive) phase of the diurnal cycle), decreased heart rate variability during the dark (active) phase, and increased food and water consumption, when compared with littermate wildtype mice. Because line 2122 of the CRH transgenic mice showed chronic stress-like neuroendocrine and autonomic changes, these mice appear to represent a valid animal model for chronic stress and might be valuable in the research on the consequences of CRH excess in situations of chronic stress.     

Clinical outcome after cyclosporine dose reduction based on C2 levels in long-term liver transplant patients

BACKGROUND: Recent studies suggest that cyclosporine dose adjustment based on C2 levels results in improvement of renal function. This study investigates the effect on renal function after dose reduction based on the C2 levels in long-term liver transplant patients. METHODS: In 60 patients (>1 yr after transplantation), C2 levels were assessed (target 600 ng/mL +/- 20%). Dose reduction was performed when C2 >720 ng/mL. Serum creatinine concentrations were measured and creatinine clearance was calculated. RESULTS: Twenty-three patients (38%) had C2 values >720 ng/mL. After dose reduction, mean cyclosporine dose decreased by 25% (p < 0.01). Mean C2 value decreased by 42% (p < 0.01). Serum creatinine concentrations remained stable. After dose reduction two patients experienced recurrence of PBC, in one patient AIH recurred and rejection was diagnosed in one patient. CONCLUSION: Cyclosporine C2 concentrations above 720 ng/mL are common in long-term liver transplant patients. Dose reduction of 25% did not improve kidney function and was accompanied by immune activation.     

Prevalence of the Wish to be of the Opposite Gender in Adolescents and Adults with Autism Spectrum Disorder

Several studies have suggested an overrepresentation of (symptoms of) autism spectrum disorder (ASD) among individuals with gender dysphoria. Three studies have taken the inverse approach in children with ASD and showed increased parent report of the wish to be of the opposite gender in this group. This study compared the self-reported wish to be of the opposite gender (one item of the Youth Self-Report [YSR] and the Adult Self-Report [ASR]) of 573 adolescents (469 assigned boys and 104 assigned girls) and 807 adults (616 assigned males and 191 assigned females) with ASD to 1016 adolescents and 846 adults from the general population. Emotional and behavioral problems were measured by the DSM-oriented scales of the YSR and ASR. In addition, the Children’s Social Behavior Questionnaire and the Adult Social Behavior Questionnaire were used to measure specific subdomains of the ASD spectrum to test whether specific subdomains of ASD were particularly involved. Significantly more adolescents (6.5%) and adults (11.4%) with ASD endorsed this item as compared to the general population (3–5%). In adolescents, assigned girls endorsed this item more than assigned boys. No significant gender differences were found in the adults with ASD. In addition, on all DSM-oriented scales of both the YSR and ASR, adolescents and adults with ASD who endorsed the gender item had significantly higher scores compared to those without. There were no significant associations between endorsement of the gender item and any specific subdomain of ASD, providing no evidence for a sole role of one of the ASD subdomains and endorsement of the wish to be the opposite gender.     

Handwriting development in grade 2 and grade 3 primary school children with normal, at risk, or dysgraphic characteristics

The wide variation in prevalence of dysgraphic handwriting (5-33%) is of clinical importance, because poor handwriting has been identified as one of the most common reasons for referring school-age children to occupational therapy or physiotherapy, and is included as an criterion for the diagnosis of Developmental Coordination Disorder. This study aimed to map the development and improvement in handwriting during the early grades to differentiate between temporary and consistent dysgraphic handwriting. In this longitudinal and cross-sectional study, children in grade 2 (age 7-8 years, n = 169) and grade 3 (8-9 years, n = 70) took handwriting (Concise Assessment Method for Children's Handwriting; acronym BHK) and visuomotor integration (BeeryVMI) screening tests twice within one school year. Dysgraphia decreased strongly from 37% to 17% in grade 2 and diminished further to a low and stable rate of 6% in grade 3. Stability in handwriting quality only occurred in the children whose scores were within the normal range. The at risk and dysgraphic children continued to show significant and substantial improvement during grades 2 and 3. BeeryVMI was inappropriate as a screening instrument for handwriting problems. It was concluded that handwriting must be consistently dysgraphic before making any decisions about a diagnosis of dysgraphia or referral for therapy.