Dysfunctional cortical connectivity during the auditory oddball task in patients with schizophrenia

Background:

We studied the imaginary coherence (IC) of gamma frequency oscillations between brain regions of male schizophrenia patients during an auditory oddball task using magnetoencephalography (MEG) and electroencephalography (EEG).

Methods:

Subjects were 10 right-handed male schizophrenia patients, evaluated by the positive and negative symptom scale (PANSS), and 10 healthy controls. Functional connectivity during the auditory oddball task was reconstructed in low (30-50 Hz) and high (50-100 Hz) gamma bands, and represented by imaginary coherence (IC) based on significant oscillatory power changes. We calculated correlations between PANSS scores and IC.

Results:

In the high gamma band, IC between left occipital and right prefrontal lobe areas during the time window 750-1000 ms from stimulus onset showed negative correlations with total negative scores, total positive scores, the sum of positive and negative scores in PANSS, conceptual disorganization, and social avoidance scores. In the low gamma band, IC between the same areas from 250-500 ms also showed a negative correlation with the conceptual disorganization score. In the same time window, IC between left occipital and right frontoparietal lobe areas in the low gamma band showed a positive correlation with hallucinatory behavior; IC between right temporal pole and left prefrontal lobe areas showed a positive correlation with delusion scores, although these ICs were decreased relative to controls.

Conclusions:

Functional disconnection of high and low gamma bands in auditory oddball task may play an important role in the auditory processing in schizophrenia patients.

An upstream estrogen response element linked to exogenous p53 tumor suppressor gene expression differentiates effects of the codon 72 polymorphism

The objective of this study was to assess the effects of an upstream estrogen response element (ERE) on exogenous p53 tumor suppressor gene with a codon 72 polymorphism about which there have been controversial reports in relation to cancer risk. The p53 gene (bases 166-1143 from start codon) with the codon 72 polymorphism, inserted into the pIRES-hrGFP II plasmid with or without upstream ERE, were transfected into HHUA endometrial cancer cells expressing the estrogen receptor. The ERE-linked p53 gene with the proline variant at codon 72 showed lower transfection rates than the gene without ERE or with the arginine variant at codon 72. p21 expression was significantly higher in HHUA cells transfected with the proline variant gene than in those transfected with the arginine variant gene. We consider that the presence of an upstream ERE promotes the transcriptional effects of the exogenous p53 gene with the proline variant, which strengthens the expression of p21, and results in lower transfection rates through cell cycle inhibition.

In vitro effect of dehydroepiandrosterone sulfate on steroid receptors, aromatase, cyclooxygenase-2 expression, and steroid hormone production in preovulatory human granulosa cells

OBJECTIVE

To examine the effect of a low concentration of DHEAS on the expression of the androgen receptor, estrogen receptor alpha and beta, progesterone receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2 in human preovulatory granulosa cells, and to measure their production of steroid hormones (estrone, estradiol, progesterone, androstenedione, and testosterone).

DESIGN

Analysis of cultured primary human preovulatory granulosa cells by real-time reverse-transcriptase polymerase chain reaction and assays of hormone production.

SETTING

Osaka City University Postgraduate School of Medicine.

INTERVENTION(S)

Preovulatory granulosa cells were collected from follicular fluid obtained from patients undergoing transvaginal oocyte retrieval with ultrasound guidance. The cells were cultured in the absence or presence of a low concentration of DHEAS. Real-time reverse-transcriptase polymerase chain reaction was performed to quantify the RNA expression of the investigated genes, and steroid hormone (estrone, estradiol, progesterone, androstenedione, and testosterone) levels were measured in the culture medium.

MAIN OUTCOME MEASURE(S)

Changes in [1] the levels of mRNAs encoding androgen receptor, estrogen receptor alpha, estrogen receptor beta, progesterone receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2; and [2] the levels of steroid hormones (estrone, estradiol, progesterone, androstenedione, and testosterone) in the culture medium.

RESULT(S)

Treatment of granulosa cells with 20 ng/mL DHEAS increased the expression of androgen receptor, aromatase, 3-beta-hydroxysteroid dehydrogenase, and cyclooxygenase-2, reduced the expression of estrogen receptor beta, and increased estrone and estradiol levels, but had no effect on progesterone, androstenedione, or testosterone levels.

CONCLUSION(S)

DHEAS may be an essential trigger of ovulation.

Insulin-Lowering Agents Inhibit Synthesis of Testosterone in Ovaries of DHEA-Induced PCOS Rats

BACKGROUND

Insulin-lowering agents are reported to be useful in treating polycystic ovary syndrome (PCOS) anovulation. It has been suggested that lower insulin levels secondarily affect ovarian tissue, although the direct mechanism of action has not yet been verified. Here we investigated if these agents directly affect the ovary.

METHODS

Thirty female Wister rats were studied. Six control rats were injected subcutaneously with 0.2 ml sesame oil, while 24 rats used as PCOS models were injected subcutaneously with dehydroepiandrosterone (DHEA) and divided into four groups. Six rats were injected with only DHEA, while the remaining 18 rats received metformin, pioglitazone or troglitazone. The ovaries were immunohistochemically stained with anti- testosterone and anti-17beta-HSD antibodies, and then evaluated for morphological changes.

RESULTS

In the DHEA administration group, the number of atretic follicles significantly increased compared to that of control rats. The insulin-lowering agents did not improve the multicystic appearance. Serum testosterone concentrations significantly increased with DHEA administration, but the increase was inhibited by oral administration of insulin-lowering agents. Testosterone deposits in ovarian tissue were also reduced by feeding rats insulin-lowering agents.

CONCLUSION

Insulin-lowering agents affected ovarian tissue by inhibiting testosterone biosynthesis in vivo.

Association of HPV infection with prognosis after neoadjuvant chemotherapy in advanced uterine cervical cancer

Whether the human papillomavirus (HPV) status of the tumor affects the sensitivity to neoadjuvant chemotherapy, and the prognosis in advanced uterine cervical cancer (FIGO stage III or higher) remains unknown. We examined the HPV status of 43 patients who had received CDDP therapy by balloon-occluded arterial infusion (BOAI), as neoadjuvant chemotherapy for advanced uterine cervical cancer (squamous cell carcinoma) stage III or higher. DNA was extracted from formalin-fixed, paraffin-embedded tumor samples obtained by punch biopsy before the neoadjuvant chemotherapy. The detection of HPV and its typing were analyzed by a polymerase chain reaction (PCR)-based assay using consensus primers for the L1 consensus regions. HPV DNA was detected in all 43 patients (100%): 29 cases with HPV 16 (67.4%), 5 cases with HPV 33 (11.6%), 4 cases with HPV 31 (9.3%), 3 cases with HPV 35 (7.0%), 1 case with HPV 18 (2.3%) and 1 case with HPV 58 (2.3%). The HPV types were divided into 3 groups, HPV 16, HPV 33 and other HPV types (HPV 18, 31, 35, 58), and comparisons and examinations were performed among the 3 groups. Although the rates of tumor reduction and operation accomplishment after 3 courses of BOAI showed no significant differences among the 3 groups, there were significant differences in the survival rates. The survival rate of advanced uterine cervical cancer patients with HPV 33 infection was the highest, followed by that of patients with HPV 16 infection. The survival rates of patients with the other types of HPV infection were the worst among the 3 groups and significantly lower than those of patients with HPV 16 or HPV 33 infection. The differences in the curative effect after BOAI may depend on the different characters of the HPV types.

High levels of intracellular ATP prevent nitric oxide-induced apoptosis in rat gastric mucosal cells

Nitric oxide (NO) plays an important role in gastric mucosal injury in the human stomach. Exposure to excessive NO leads to apoptosis; however, the mechanism remains largely unknown in gastric epithelial cells. The apoptotic process is modulated by energy states in cells. This study investigated molecular mechanisms of NO-induced apoptosis in gastric epithelial cells and influence of high glucose on those mechanisms. Normal rat gastric mucosal epithelial (RGM-1) cells were cultured in media containing either 1000 (low) or 4500 mg/l (high) of D-glucose. When the cells were incubated with a chemical NO donor NOC18, apoptosis was induced in a dose-dependent manner. Intracellular adenosine triphosphate (ATP) levels significantly increased in the cells cultured with high glucose in comparison with the low-glucose condition. The cells with high ATP levels were more resistant to NO-induced apoptosis than the cells with low ATP levels. NO-induced apoptosis was followed by mitochondrial depolarization, upregulation of Bax protein, cytochrome C release from mitochondria to the cytosol and subsequent caspases activation. These results suggest that NO inhibition of mitochondrial respiratory system and acute ATP depletion initiate apoptotic signalling in gastric epithelial cells. High glucose may prevent NO-induced apoptosis by leading to high levels of intracellular ATP or other metabolic changes in this cell line.

VEGF mRNA in adipocytes increase with rebound weight-gain after diet-restriction

The mechanism of rebound body weight-gain after a restricted-diet state is unclear. We investigated the expression of angiogenic factors in human adipocytes with a changing nutritional state in culture medium, and attempted to ascertain the mechanisms involved in rebound weight-gain. Adipocytes were divided into three groups; the first group (control group) was cultured in medium with 10% fetal calf serum (FCS), the second (DR3% group) was cultured in medium with 3% FCS, and the third (DR6% group) was cultured in medium with 6% FCS. After being cultured for 48 h, each was next cultured with 12% FCS for a further 48 h. When made to change from a low nutrition state to a higher one, adipocytes changed from hypotrophic to hypertrophic. Simultaneously, vascular endothelial growth factor (VEGF) in the culture medium increased significantly. When investigated immunohistochemically, the expression of VEGF was similarly shown in the cytoplasm of adipocytes. The same tendency with the same quantity of mRNA was shown by RT-PCR. These results show that VEGF produced and secreted from adipocytes increases, when the cultivation state of adipocytes is changed from a low nutritional state to a higher one. VEGF produced and secreted from adipocytes may be related to rebound weight-gain.

Expression and distribution of cyclooxygenase-2 in human ovary during follicular development

Prostaglandins play important roles for oocyte maturation and follicular rupture. Cyclooxygenase-2 (COX-2), an inducible isoform of a prostaglandin metabolic enzyme, is essential for the timed production of prostaglandins in the ovary. The aim of the present study is to examine expression and distribution of COX-2 in human ovarian follicles at each of the maturation stages. Immunohistochemical staining shows that COX-2 is expressed in the granulosa cell layer of secondary and developing follicles, but is not detected in primary and Graafian follicles. Western blotting analysis revealed the existence of COX-2 in periovulatory follicular fluid at a mean concentration of 5.6 +/- 0.6 ng/ml. COX-2 might begin to be produced at the secondary follicle stage, and once a follicle reaches the Graafian follicle stage, the production of this enzyme is stopped. After exposure to luteinizing hormone (LH) surge, follicles might resume production of COX-2, and this is secreted into the follicular fluid.

Metachromasia of the endocervical epithelium in women treated with gonadotropin releasing hormone agonist

Endocervical epithelium from women treated with gonadotropin releasing hormone agonist (GnRH agonist) were compared with those from untreated women, using metachromatic stain with toluidine blue and immunohistochemistry, for estrogen and progesterone receptors. Smaller endocervical epithelium with lower intraepithelial mucus and more prominent nuclear distribution of estrogen receptors were seen in a woman who was treated for twelve months with GnRH agonists, as compared with those from an untreated premenopausal woman.

Conservative management of placental polyp with oral administration of methotrexate

Surgical treatment is usually selected for placental polyp accompanied by massive bleeding but patients wishing to conserve their fecundity require conservative management. A 35-year old nullipara was diagnosed as having placental polyp on the basis of typical episodes, and detection of placental polypeptide hormones and blood flow by Doppler ultrasonography and dynamic magnetic resonance imaging. Oral administration of methotrexate (2.5 mg, three times a day for 5 days) was repeated for three cycles because surgical treatment was rejected. Serum human placental lactogen, blood flow and the polyp disappeared sequentially following chemotherapy. This report thus advocates considering conservative management for placental polyp.

Mouse erythroblast formation is inhibited by anemia-inducing substance from the plasma of a patient with a malignant neoplasm

An anemia-inducing substance (AIS) was found as a protein, with a molecular weight of 50,000 on SDS electrophoresis gel, that decreased the osmotic resistance of erythrocytes. In this study, the plasma fraction containing AIS is shown to inhibit mouse erythroblast formation in vitro. The addition of the plasma fraction from a patient with an advanced malignant neoplasm to a liquid culture of mouse bone marrow cells with erythropoietin results in low numbers of erythroblast formation and low cellular yields of alpha- and beta-globin mRNAs. These inhibitions were not observed after immunoadsorption of the plasma fraction with an antiserum against AIS.

CD71 antibody enhances iron uptake by mouse bone marrow cells and the survival potential of erythroid progenitor cells

Transferrin has been shown to have cytoprotective functions. The aim of this study was to evaluate the effect of antibody against CD71 (transferrin receptor) on survival potential of erythroid progenitor cells. After anti-CD71 IgG or control IgG was reacted with cells for 20 min on ice, the uptake of transferrin-bound 59Fe by the MEL cells or the mouse bone marrow cells during 2-day incubation without erythropoietin was measured. Erythropoiesis was evaluated by addition of erythropoietin after 4-5 weeks' culture without erythropoietin or beta-mercaptoethanol, and production of cells containing hemoglobin was compared by immunocytological methods. MEL cells reacted with anti-CD71 IgG incorporated more transferrin-bound 59Fe than MEL cells reacted with control IgG. Uptake of transferrin-bound 59Fe by mouse bone marrow cells reacted with anti-CD71 IgG was also greater than by cells reacted with control IgG. Erythrocytes developed from cells reacted with anti-CD71 IgG and cultured for 4-5 weeks, but few erythrocytes developed from cells reacted with control IgG. Bone marrow cells depleted of TER119+ cells, CD34+ cells, or CD45+ cells and reacted with CD71 antibody did not differentiate into erythrocytes. Survival potential of erythroid progenitor cells were enhanced by reaction with anti-CD71 antibody.

Expression of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing rabbits

We reported finding that apoptosis occurred in skeletal muscle in the early stage after implantation. In the present study, we investigated expression of the apoptosis-related proteins Bax and Bcl-2 to determine the mechanism of the apoptosis. In the early stage of tumor bearing, 20 days after implantation, lean body mass (LBM) was reduced by 5.06 +/- 1.10% in the tumor-bearing group, compared with an increase of 4.96 +/- 1.26% in the control group. The apoptotic index (AI) of the skeletal muscle in the tumor-bearing group increased to 40.5 +/- 3.20% but was 0% in the control group, and Bax expression was strongly positive in 5 of the 10 rabbits in the tumor-bearing group, and significantly stronger than in the control group (P = 0.0002). In the late stage of tumor bearing, 40 days after implantation, the AI had declined to 0.93 +/- 0.96% in the tumor-bearing group, but was still 0% in the control group. Bax expression was rarely detected in either the tumor-bearing group or the control group, and there was no significant difference between the two groups (P = 0.706). No significant changes in Bcl-2 were observed in either group. The above results showed that apoptosis via Bax played a role in muscle wasting associated with progression of the malignant tumor. However, the apoptosis and expression of Bax were seen only in the early stage, within 20 days after implantation, not in the late stage. This suggested that the muscle wasting in the early stage might be caused by a different mechanism from that in the late stage.

Apoptosis of muscle cells causes weight loss prior to impairment of DNA synthesis in tumor-bearing rabbits

The mechanism of weight loss induced by the growth of malignant tumors is still unknown. We investigated it by focusing on apoptosis of skeletal muscle. VX2-tumor was implanted into rabbits and the apoptotic index (AI) of skeletal muscle was measured by in situ end-labeling assay. Plasma of the tumor-bearing rabbits was perfused repeatedly through non-coated charcoal resin. The AI reached 54.6% early after tumor implantation, when weight loss amounted to an 18% decrease in lean body mass (LBM) without change in muscle DNA synthesis or urinary 3-methylhistidine / creatinine ratio (3-MH / Cr). When the decrease of LBM reached 30%, DNA synthesis was decreased by 48% and 3-MH / Cr was increased by 104%, whereas AI was only 4.7%. The plasma perfusion did not prevent apoptosis in muscle, but improved LBM, DNA synthesis, and 3-MH / Cr. There may be two mechanisms of muscle depletion during the tumor growth: apoptosis in the early stage and metabolic abnormalities in muscle in the late stage.

Transmission of symptomatic parvovirus B19 infection by fibrin sealant used during surgery

Human parvovirus B19 infection has been shown to be transmissible by blood and blood products and to result in transient aplastic crisis in patients with rapid red cell turnover. We report three cases of iatrogenic parvovirus B19 infection resulting from the use of the same batch of fibrin sealant under operation. Fibrin sealant, which is a typical haemostatic agent produced from blood, has been used during surgery. Human parvovirus is resistant to existing virus-inactivating techniques, suggesting that infection may occur from blood products contaminated with it. Use of recombinant products for these proteins may thus be necessary.