Predictors of negative symptoms in the chronic phase of schizophrenia: A cross-sectional study.

This study was designed to investigate the relationship between negative symptoms and key indicators for long-term hospital stays among inpatients with schizophrenia. A further aim was to elucidate the clinical determinants of negative symptoms. The following were used as index factors: age, duration of illness, duration of hospitalization, age at onset, years of education, smoking status, body mass index, concentrations of serum triglycerides, total cholesterol, uric acid, QTc interval duration from electrocardiography, dose equivalents of antipsychotic and anticholinergic agents, neurocognitive function, drug-induced extrapyramidal symptoms, involuntary movements, and psychiatric symptoms. Spearman's rank correlation coefficients were calculated and regression analyses were performed to examine associations between these factors and negative symptoms. Positive symptoms correlated positively with negative symptoms as rated on the Brief Psychiatric Rating Scale. Age at onset correlated negatively with negative symptoms. Multiple regression analysis showed that dose equivalents of atypical antipsychotics and positive symptoms predicted negative symptoms. Increasing our understanding of these predictors as key indicators of the severity of negative symptoms may aid in the reconsideration of therapeutic programs for chronic schizophrenia.

Additional effect of epidermal growth factor during in vitro maturation for individual bovine oocytes using a chemically defined medium.

This study was performed to establish an individual bovine oocyte-IVP system using a chemically defined simple medium (mSOFaa containing 1 mg/ml polyvinyl alcohol: PVA) and to investigate the effects of epidermal growth factor (EGF) during oocyte maturation on in vitro maturation, fertilization and embryonic development. Cumulus-oocyte complexes were collected from bovine ovaries and were matured in mSOFaa containing PVA (control medium) supplemented with 0, 1, 10 or 50 ng/ml of EGF. Two further groups (TCM199 and mSOFaa, supplemented with 10% fetal calf serum were also included. In this study, mSOFaa containing PVA were used as a basic medium for fertilization and embryo development in vitro. Experiments were conducted in both group- and individual-IVP systems. In the group-IVP system, the proportion of matured oocytes (MII) in the control medium (62.7% +/- 5.0%) was significantly (p < 0.05) lower than in all other treatments, and in the individual-IVP system, the addition of 1 ng/ml EGF significantly (p < 0.05) increased the maturation rate (1 ng/ml EGF vs control: 76.2% +/- 5.4% vs 57.1% +/- 14.4%). The addition of EGF did not affect the proportions of penetrated and normally fertilized oocytes in either individual- or group-culture systems. In the group-IVP system, no significant difference among treatments was found in the rate of blastocyst formation, whereas in the individual-IVP system the control medium supplemented with 10 ng/ml EGF resulted in a significantly (p < 0.05) higher the rate of blastocyst formation (20.0 +/- 5.2%) than that in the control medium (6.2% +/- 3.5%). These results indicate that bovine oocytes can successfully develop to blastocysts in an individual-IVP system using a single chemically defined medium, and that the group-IVP system also resulted in a similar level of blastocyst formation to that in a standard multiple-media system in our laboratory. The effect of EGF during oocyte maturation medium differed depending on whether embryos were cultured individually or in groups.

Oxygen tension and medium supplements for in vitro maturation of bovine oocytes cultured individually in a chemically defined medium.

The effects of adding cysteamine, EGF, and glucose as an energy substrate under low oxygen tension during in vitro maturation (IVM) were examined to find ways of improving the individual in vitro production (IVP) system in individually cultured bovine oocytes. The basic medium was mSOFaa containing 1 mg/ml polyvinyl alcohol. Immature oocytes were individually cultured in an IVM medium with 10 ng/ml EGF, 100 microM cysteamine, or EGF plus cysteamine under 20% or 5% O(2). Cleavage and blastocyst rates were significantly higher (P<0.05) in IVM culture was under 20% O(2) than in culture under 5% O(2). Under 5% O(2), neither EGF nor cysteamine improved embryonic development. The proportion of matured oocytes was significantly higher (P<0.05) in the presence of 1.5 mM glucose under 20% O(2) (68.6%), and 5.5 mM (66.7%) and 10 mM (65.5%) glucose under 5% O(2). The presence of 5.5 mM glucose significantly (P<0.05) increased the maturation rate compared with the absence of glucose, irrespective of addition of EGF and cysteamine. The addition of cysteamine alone in the maturation medium significantly (P<0.05) increased the intracellular GSH concentration in the oocytes. Also, under 5% O(2) cysteamine and/or EGF significantly (P<0.05) improved the proportions of penetrated oocytes, cleavage and blastocyst formation, which were similar levels to those of oocytes matured under 20% O(2). After vitrification, the re-expanding and hatching rates of blastocysts derived from the individual IVP system containing cysteamine under 5% O(2) were significantly (P<0.05) higher than those of blastocysts derived from the individual IVP system without cysteamine under 5% O(2) and the group IVP system under 20% O(2). The present study showed that a high glucose level (5.5 or 10 mM) was optimal in IVM culture under low (5%) oxygen tension. The addition of EGF and/or cysteamine to the maturation medium had no positive effect on nuclear maturation, but improved fertilizability, developmental competence and cryoresistance following vitrification, probably due to increased GSH synthesis during the IVM process.