Conditional calcineurin knockout mice exhibit multiple abnormal behaviors related to schizophrenia

Calcineurin (CN), a calcium- and calmodulin-dependent protein phosphatase, plays a significant role in the central nervous system. Previously, we reported that forebrain-specific CN knockout mice (CN mutant mice) have impaired working memory. To further analyze the behavioral effects of CN deficiency, we subjected CN mutant mice to a comprehensive behavioral test battery. Mutant mice showed increased locomotor activity, decreased social interaction, and impairments in prepulse inhibition and latent inhibition. In addition, CN mutant mice displayed an increased response to the locomotor stimulating effects of MK-801. Collectively, the abnormalities of CN mutant mice are strikingly similar to those described for schizophrenia. We propose that alterations affecting CN signaling could comprise a contributing factor in schizophrenia pathogenesis.     

Molecular-cytogenetic analysis of HER-2/neu gene in BRCA1-associated breast cancers

The BRCA1 tumor suppressor gene and the HER-2/neu oncogene are located in close proximity on the long arm of chromosome 17 (17q11-21). Absence of BRCA1 or functional overexpression of the HER-2/neu gene presumably contributes to the somatic phenotype of breast cancer in premenopausal women, characterized by unfavorable prognostic features such as high tumor grade, hormone receptor negativity, and high proliferation rate. To examine whether amplification of HER-2/neu contributes to the aggressive biology of BRCA1-associated tumors, we have performed fluorescence in situ hybridization on formalin-fixed paraffin-embedded breast tumor tissue sections from 53 BRCA1 mutation carriers and 41 randomly selected, age-matched sporadic breast cancer cases. Although BRCA1-associated and sporadic tumors were equally likely (19% versus 22%) to exhibit HER-2/neu amplification [defined as a ratio of HER-2/neu copies to chromosome 17 centromere (CEP17) copies > or = 2], 6 (15%) of the sporadic tumors were highly amplified (defined as a ratio greater-than-or-equal 5) versus none of the BRCA1-associated tumors (P = 0.048). HER-2 protein overexpression as measured by immunohistochemical analysis was not observed among the BRCA1-associated cases (P = 0.042). Four of 21 (19%) sporadic tumors exhibited strong membranous staining of HER-2 (intensity level of 3+) as compared with 0 of 39 BRCA1-associated tumors. Our data suggest that a germ-line mutation in the BRCA1 tumor suppressor gene is associated with a significantly lower level of HER-2/neu amplification. Thus, it is possible that BRCA1-associated and HER-2/neu-highly amplified tumors progress through distinct molecular pathways, and the aggressive pathological features of BRCA1-associated tumors appear unrelated to amplification of the adjacent HER-2/neu oncogene.     

Immunohistochemically detectable bcl-2 expression in metastatic melanoma: association with survival and treatment response

OBJECTIVE: The antiapoptotic protein Bcl-2 is supposed to influence the treatment responsiveness of different malignancies. In the present study the prognostic and predictive significance of Bcl-2 expression for survival and response to an administered therapy was explored in patients with metastatic melanoma. Also, the correlation between Bcl-2 expression and proliferation activity of tumor cells was defined to examine the regulatory role of Bcl-2 in proliferation. MATERIALS AND METHODS: Sixty metastatic melanomas obtained from patients treated with chemoimmunotherapy were examined by immunohistochemistry with anti-Bcl-2 and anti-Ki-67 (MIB-1) antibodies. Proliferation activity was expressed in percentages as MIB-1 index. RESULTS: The presence of Bcl-2 immunoreactivity was associated with a significantly lower MIB-1 index (p = 0.016), and a longer disease-free survival (p = 0.004). The lack of Bcl-2 expression was related to a higher response rate to therapy in comparison to a diffuse and focal pattern of Bcl-2 expression (p = 0.017). Although the presence of Bcl-2 immunoreactivity as such did not correlate with survival after the initiation of chemoimmunotherapy, the focal Bcl-2 expression pattern was strongly associated with a worse prognosis compared to a diffuse expression or a lack of Bcl-2 staining (p < 0.0001). CONCLUSIONS: Our results support the role of Bcl-2 in the regulation of cell proliferation and suggest that an increase of metastatic potential and progression of malignant melanoma is associated with a loss of Bcl-2 expression. The lack of Bcl-2 expression could be a predictor of the response to chemoimmunotherapy, whereas the Bcl-2 expression pattern, possibly indicating the heterogeneity of the tumors, might be a potential prognostic factor for survival after the initiation of therapy.     

Cytostatic therapy and blood antioxidants/prooxidants balance in acute myeloblastic leukemia patients

To analyze the effects of conventional polychemotherapy of acute myeloblastic leukemia (AML) patients on the prooxidants/antioxidants balance in plasma total antioxidant status (TAS) and a single plasma antioxidant — uric acid (UA) were measured. Lipid peroxidation was assessed by malonedialdehyde (MDA) content. Total serum iron was monitored as a potential source of nontransferrin-bound iron with a role in initiation of oxidative burst. A group of patients in the acute phase of AML (group A) and a group of patients in complete remission of AML (group B) were studied. A strong correlation between UA values and TAS (r = 0.8 for group A, r = 0.9 for group B) was revealed in the course of the treatment. Strong negative correlation (r = −0.9) between TAS and MDA was shown for both groups. Total iron significantly increased in the course of chemotherapy. We have established that polychemotherapy leads to the consumption of antioxidants and increased lipid peroxidation in AML patients. An appropriate supplementation with antioxidants at the end of the polychemotherapy treatment could be considered.     

An intervention program to reduce the number of hospitalizations of elderly patients in a primary care clinic

Background  

The elderly population consumes a large share of medical resources in the western world. A significant portion of the expense is related to hospitalizations.     

Neurospecific S-100 protein content in brains of different mouse strains

Total whole brain concentrations of S-100 protein and of its water-soluble fraction were determined in 11 inbred mouse straine: DBA/2J, AKR/J, CBA/Lac, C57BL/6J, C57BL/6J-Ay, C3H/He, C3H/f, DD, A/He, BALB/cLac, CC57BR/Mv, and in cerebral cortex, cerebellum and hippocampus in DBA/2J, AKR/J and CBA/Lac strains. Highly significant differences in the concentrations of the water-soluble S-100 protein were found between some strains. Slight differences were found in total S-100 protein content in whole brains between the strains (0.01 less that P less than 0.05). The DBA/2J mice had the highest brain S-100 protein content, and were characterized by a higher learning rate in shuttle-box as compared to CBA/Lac and AKR/J mice, who had a low content of this neurospecific protein.     

Radiation-enhanced endostatin gene expression and effects of combination treatment

Targeting cells that support tumor growth by administering potent angiogenesis inhibitors is currently an area of intense interest. In the present study, a unique plasmid vector for the mouse endostatin gene, pXLG-mEndo, was constructed and evaluated with and without radiation using the Lewis lung carcinoma (LLC) cell line. The physical properties of the expressed endostatin protein were validated by PCR, gel electrophoresis, and Western blot. Enzyme-linked immunosorbent and immunocytochemical analyses for the therapeutic gene demonstrated that transfected LLC cells secreted the protein into the medium. Exposure of the cells to 2 gray (Gy) gamma-rays reduced the time to reach the maximum expression level of the endostatin gene and also increased the amount of secreted endostatin protein (P<0.001). Biological activity of the endostatin was demonstrated by the inhibition of tube formation by human umbilical vein endothelial cells (HUVEC). Based on (3)H-thymidine incorporation, endostatin expression significantly depressed DNA synthesis in HUVEC and LLC cells compared to controls transfected with parental vector or no vector (P<0.005). In addition, radiation increased the efficiency of endostatin-mediated inhibition of both cell types over a 3-day period post-exposure (P<0.05 or less). Intratumoral injection of 100 small mu g pXLG-mEndo combined with 10 Gy radiation significantly delayed LLC tumor growth, especially when each modality was delivered twice (P<0.05 or less compared to all other groups). No toxicity was observed. These findings are very promising and suggest that endostatin therapy with a plasmid vector, such as pXLG-mEndo, may enhance the efficacy of radiotherapy for lung cancer.     

Vaccinia virus mediated p53 gene therapy for bladder cancer in an orthotopic murine model

PURPOSE: We determined if vaccinia virus (VV) mediated delivery of human tumor suppressor p53 is safe and effective for bladder tumor therapy in an orthotopic murine model. MATERIALS AND METHODS: We used recombinant VV (rVV) vectors to express transgenes in murine bladder cancer MB-49 cells in culture and those growing orthotopically in syngeneic mice. Cultured MB-49 cells were infected with rVV expressing reporter genes (rVV-L15) or p53 (rVV-TK-53) to measure virus infection and apoptosis induction. Orthotopic MB-49 tumors in C57/Bl6 mice were treated with intravesical instillation of rVV, and the tumor incidence, survival and transgene expression were determined. RESULTS: Productive virus infection in vitro was observed in MB-49 cells, although at somewhat lower efficiency than in African Green Monkey kidney CV-1 cells (American Type Culture Collection, Manassas, Virginia). Expression of transgenes in vitro correlated with the virus dose. Cells infected with rVV underwent apoptosis with rVV-TK-53 inducing far greater cell death than rVV-L15. The rVV-L15 virus had no effect on tumor incidence but it increased mean survival compared with control. Instillation of rVV-TK-53 decreased the tumor incidence and 33% of mice survived treatment. At necropsy all nonsurviving mice had bladder tumor, whereas 2 survivors in the rVV-TK-53 treated group were tumor-free. Immunohistochemistry of tumors detected expression of the human p53 gene product in tumor cells. CONCLUSIONS: To our knowledge we report for the first time that recombinant vaccinia virus expressing human p53 can induce the death of MB-49 tumor cells in vivo, not only through the lytic effect of the virus, but also through expression of the death inducing p53 transgene. Further studies are needed to shed light on the mechanisms of rVV-TK-53 mediated tumor apoptosis and the antitumor immune response.