Ultrastructural changes in hepatocytes of precision-cut rat liver slices after incubation for 24 and 48 hours

Hepatocytes of precision-cut rat liver slices were studied by means of transmission electron microscopy after long-term incubation (24–48 h) in comparison with freshly prepared slices, indicating reversible and irreversible intracellular alterations of the cells. After 24 h incubation the morphological image in transversal sections of slices is characterised by a central zone of damaged and necrotic cells flanked by two to several superficial layers of viable cells. This is typical of a diffusion gradient of oxygen tension and nutrient content from the surface to the centre of the slices. In adapted cells on the surface of the slices we observed an organelle-free layer of fine granular material in the apical cytoplasm followed by parallel oriented stacks of rough endoplasmic reticulum near by. Mitochondria of essentially normal appearance in adapted cells did not contain flocculent densities, which were observed in damaged cells only. The cytoplasm of parenchymal cells consisted of defined areas of clear cytoplasmic material containing numerous branching tubular profiles of smooth endoplasmic reticulum, presumably in the regions with depleted glycogen aggregates. Subcellular signs of necrosis are destroyed mitochondria, dilated endoplasmic reticulum free of ribosomes and clumping of chromatin in the nucleus of hepatocytes. No appreciable differences of the cell organelles were observed between 24 and 48 h of incubation, but the incidence and intensity of signs of necrosis increased with the duration of incubation and the thickness of the slices. The process of these changes may reflect the phenomenon of cellular adaptation and of hypoxic cellular injury in the periphery and the centre of the slices, respectively.     

5,10-Methylenetetrahydrofolate reductase genotype determines the plasma homocysteine-lowering effect of supplementation with 5-methyltetrahydrofolate or folic acid in healthy young women

BACKGROUND: Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease and neural tube defects. The polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase (FADH(2)) (MTHFR) influences the tHcy concentration and the response to tHcy-lowering therapy. Supplementation with folic acid (FA) decreases plasma tHcy, but limited data are available on the effect of 5-methyltetrahydrofolate (MTHF). OBJECTIVE: We evaluated the tHcy-lowering potential of low-dose FA and of MTHF with respect to the MTHFR genotype. DESIGN: In this randomized, placebo-controlled, double-blind study, 160 women received 400 microg FA, the equimolar amount of MTHF (480 microg, racemic mixture), or a placebo daily during an 8-wk treatment period. Blood samples were collected at baseline and at 4 and 8 wk. RESULTS: Changes in plasma tHcy concentration depended on the supplemented folate derivative and the MTHFR genotype. Supplementation with FA significantly decreased tHcy concentrations by > or = 13% in women of all 3 genotypes after both 4 and 8 wk. The greatest decrease was 20% (P < 0.05) in the women with the TT genotype after 4 wk. MTHF supplementation also decreased tHcy, but only the women with the CT genotype had a significant decrease after 4 wk (7%; P < 0.05). The largest nonsignificant reduction (15%) occurred in the women with the TT genotype after 4 wk of MTHF supplementation. CONCLUSIONS: The response to tHcy-lowering therapy is influenced by MTHFR genotype. Women with the TT genotype seem to benefit the most from supplementation with either FA or MTHF. In women with the CT or CC genotype, FA is more effective than MTHF in lowering plasma tHcy.     

Early event-related potential changes during working memory activation predict rapid decline in mild cognitive impairment

BACKGROUND: The conversion of mild cognitive impairment (MCI) to Alzheimer's disease is associated with substantial compromise of neocortical circuits subserving rapid cognitive functions such as working memory. Event-related potential (ERP) analysis is a powerful tool to identify early impairment of these circuits, yet research for an electrophysiological marker of cognitive deterioration in MCI is scarce. Using a "2-back" activation paradigm, we recently described an electrophysiological correlate of working memory activation (positive-negative working memory [PN(wm)] component) over parietal electrodes. METHODS: Ours was a longitudinal study of 24 MCI patients with ERP analysis at inclusion and neuropsychological follow-up after 1 year. We used ERP waveform subtraction analysis between the n-back and control tasks. Analysis of variance (ANOVA) was used to compare electroencephalograph latencies between progressive MCI (PMCI) and stable MCI (SMCI), and univariate regression was used to assess the relationship between neuropsychological measures at baseline and clinical outcome. RESULTS: Thirteen (54%) MCI patients showed PMCI, and 11 (46%) remained stable (SMCI). In SMCI, a PN(wm) component with significantly larger density compared to baseline was identified when subtracting the detection task for both the 1- and 2-back tasks. In contrast, in PMCI, the PN(wm) component was absent in both 1-back and 2-back conditions. Neuropsychological variables and n-back test performance at inclusion did not predict cognitive deterioration 1 year later. CONCLUSIONS: In conjunction with recent functional imaging data, the present results support the notion of an early dysfunction of neural generators within the parietal cortex in MCI. They also reveal that the absence of the PN(wm) component may provide an easily applicable qualitative predictive marker of rapid cognitive deterioration in MCI.     

Development and characterization of a 293 cell line with regulatable expression of the hepatitis B virus large envelope protein

During the life cycle of hepatitis B virus (HBV) the large L envelope protein plays a pivotal role that is related to its peculiar dual transmembrane topology. To study the complex structure and diverse functions of L under regulated conditions of production, a human 293 cell line stably expressing L under the control of the ecdysone-inducible promoter was generated. Cells demonstrated stringent dose- and time-dependent kinetics of induction with undetectable background expression in the absence of the inducer. Temporal control of L expression allowed to trace (i) its posttranslational reorientation resulting in the mixed topology; (ii) its spatial redistribution from the endoplasmic reticulum to Golgi-like structures; and (iii) its intracellular retention in a membrane-associated configuration. On regulated overproduction, L blocked the secretion of HBV small envelope polypeptides without impairing the cell secretory apparatus. Despite the continuous high-level storage of L within the 293 cell line, no cytopathic effects could be detected. This is in contrast to ground-glass hepatocytes of chronic HBV carriers and HBV transgenic mice and may imply that the intracellular storage of L is particularly damaging to the liver cell.     

Potential determinants of obesity among children and adolescents in Germany: results from the cross-sectional KiGGS study

Background  

Obesity among children and adolescents is a growing public health problem. The aim of the present paper is to identify potential determinants of obesity and risk groups among 3- to 17-year old children and adolescents to provide a basis for effective prevention strategies.     

Autoantibody reactivity in serum of patients with major depression, schizophrenia and healthy controls

The present study assessed 25 patients with unipolar major depression and 34 patients with schizophrenia along with 50 healthy, non-psychiatric controls for the presence of serum antinuclear (ANA), smooth muscle (SMA), anti-endothelial (AEA), anti-sarcolemma (ASA), thyroid gland (TGA) and parietal cell (PCA) antibodies. In the group of patients with major depression, the frequency of elevated ANA, TGA and PCA was significantly higher than in the control group. In addition, the group of patients with schizophrenia significantly more often showed increased levels of ANA and SMA than the control group of healthy volunteers. When the two psychiatric groups were compared, PCA serum titers in major depression and SMA values in schizophrenia were significantly more frequently elevated, whereas values of AEA and ASA showed no difference. These results point towards the existence of an unspecific (auto) immune disposition or reaction in at least a subgroup of patients with major depression and schizophrenia.     

Proteases and their inhibitors as prognostic factors for high-grade serous ovarian cancer

Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.     

A randomized trial of short psychotherapy versus sustained‐release bupropion for smoking cessation

Aims To compare the efficacy and safety of a novel psychological intervention for smoking cessation called psychodynamic model (PDM) training to an active control condition of sustained‐release bupropion. Design Randomized controlled clinical trial with allocation concealment. Setting Private psychiatric practice. Participants Seven hundred and seventy‐nine adult smokers recruited by advertising. Interventions PDM training (n = 366 participants) consisted of a very brief (1.5 days) psychoeducation and a supervised training in autosuggestion techniques (guided imageries) aimed at enhancing self‐management, decidedness, assertiveness, security and competence in relationships, natural functions of organs and awareness of bodily functions. Bupropion SR (n = 413) was increased to 150 mg twice daily over 1 week and given over a 8‐week period. Measurements Twelve‐month continuous abstinence confirmed by exhaled carbon monoxide (CO) of 9 parts per million (p.p.m.) or less at all interviews conducted at 3, 6 and 12 months. Findings Intention‐to‐treat analysis revealed Russell standard 12‐month continuous abstinence rates of 39.1% in the psychotherapy group versus 12.3% in the bupropion SR group (P < 0.001) with a relative benefit (RB) of 3.16 (2.38–4.26). Completer analysis revealed 12‐month continuous abstinence rates of 39.9% in the psychotherapy group versus 22.5% in the bupropion group [P < 0.001; RB 1.78 (1.35–2.34)]. Of note, bupropion abstinence rates were comparable to previous medications/placebo‐only comparisons in geographically different samples. Conclusions The 1.5‐day psychotherapy exceeded bupropion's efficacy, presenting an alternative to pharmacological smoking cessation aids, especially for smokers who reject drugs to treat their substance dependence, at a similar cost (€350) as the bupropion treatment (€355).     

Role of the Dorso—Caudal Neostriatum in Filial Imprinting of the Domestic Chick: a Pharmacological and Autoradiographical Approach Focused on the Involvement of NMDA-Receptors

Newly hatched domestic chicks were either acoustically imprinted on 400 Hz tone pulses or visually imprinted on a rotating red light. Compared to naive control animals, both groups of imprinted chicks expressed significantly enhanced stimulus evoked 2-fluoro-2-deoxyglucose (2-FDG) uptake in circumscribed areas of the dorso-caudal neostriatum (Ndc). This enhanced excitability after imprinting seems not to be related to changes of NMDA-receptor densities as measured by quantitative receptor autoradiography. However, pharmacological blockade of NMDA-receptors in the dorso-caudal neostriatum leads to a marked suppression of stimulus-evoked 2-FDG uptake in the dorso-caudal neostriatum and also in the interconnected imprinting relevant forebrain area, medio-rostral neostriatum/hyperstriatum ventrale (MNH). Furthermore, chicks which received bilateral Ndc injections of the competitive NMDA antagonist DL-2-amino-5-phosphono valeric acid (APV) during the imprinting experiments showed a dose-dependent decrease of imprinting success compared to vehicle-injected controls. These results indicate that the dorso-caudal neostriatum may represent a polysensory associative brain region in which visual and acoustic features of imprinting objects may be integrated. The activation in this area evoked by the imprinting stimulus during and after imprinting is critically dependent on NMDA-receptor activation, which appears to be required for this learning process.