Depressive Symptoms Among HIV Positive Men: Life Stress,Coping, and Social Support1

The significance of life stress, coping, and social support was examined in relation to depressive symptomatology in a sample of 160 asymptomatic and mildly symptomatic HIV-antibody-positive (HIV+) men. The participants (mean age = 32 years) were interviewed about the life stress that they had experienced in the previous 6     

Telomerase activity in prognostic histopathologic features of melanoma.

BACKGROUND: Telomerase activity (TA) is believed to play a role in the regulation of senescence and to limit the number of cell divisions. The deregulation of telomerase appears to contribute to oncogenesis and the formation of immortal cell lines. As a result, it is believed that it could be used as a prognostic marker in melanoma. METHODS: TA was assayed by the polymerase chain reaction PCR-ELISA-based telomeric repeat amplification protocol (TRAP assay). One hundred and eight samples were distributed in four histological groups: 30 samples from primary cutaneous melanomas, 24 from peritumoural skin sites, 28 from benign melanocytic lesions, and 26 from normal skin sites as a control. RESULTS: TA was different among the four tested groups (Kruskall-Wallis test p<0.001), and increasing values of TA were observed progressing from normal skin to benign and then to malignant lesions. Among melanoma samples, there was a significant association between TA and ulceration (p=0.025), TA and vascular invasion (p=0.018) and TA and mitotic rate (p=0.029) (Mann-Whitney test). A linear regression analysis showed significant associations between the increase of TA with Breslow thickness (p=0.004) and the presence of satellites (p=0.002). CONCLUSIONS: We observed that TA had increased from control skin to peritumoural skin, and then to benign melanocytic lesions and finally to melanoma, suggesting tumour progression. TA showed higher values in the presence of some important histopathologic parameters related to poor prognosis in cutaneous melanoma such as ulceration, vascular invasion, satellites, high rates of mitosis, and in thicker tumours.     

Aneuploidy of chromosome 20 in invasive breast cancer correlates with poor outcome

Breast carcinoma is a genetically and phenotypically heterogeneous disease and is frequently associated with nonrandom chromosomal alterations. The aim of this study was to investigate the numerical aberrations of chromosome 20 in breast cancer. The observed chromosome-specific numerical abnormalities were evaluated along with the established clinicopathological parameters, the immunohistochemical expression of ER, PR, p53, c-erbB-2, Ki-67 and patients' survival. Nonisotopic in situ hybridization was applied to interphase cell nuclei on paraffin embedded tissue sections. Polysomy of chromosome 20 was the prevalent alteration in 45 of 50 (90%), monosomy in 2 of 50 (4%) and disomy in 3 of 50 (6%) cases. Invasive ductal carcinomas displayed a higher percentage of polysomy than lobular ones. A statistical significant association was demonstrated between Ki-67 immunohistochemical expression and polysomy of chromosome 20. Disomy was inversely correlated with Ki-67, while monosomy was suggestively associated with PR positive expression. Among the patients, those with the highest levels of polysomy showed the worst survival. In conclusion, the gain of chromosome 20 is the prevalent aberration in patients with breast carcinomas and may be useful prognostic marker in breast cancer.     

Borna disease (BD), a slow virus infection biological properties of the virus

Borna disease, a typical slow virus infection, was investigated in different animal species. Infectious virus in the brain and complement-fixing and precipitating antibodies in the circulation could be detected simultaneously several months p.i. The infectious agent was propagated in rabbit brain tissue cultures, which were cocultivated with green monkey kidney cells. Infectious virus and virus-specific antigens were demonstrable in the cell cultures during several subpassages. The infectivity was assayed by inoculation of rabbits; specific antigens in the cell cultures were tested with complement fixation, immunodiffusion and immunofluo-rescence. The increase of antigens with the prolongation of the incubation period proves that virus replication has taken place in the cultured cells.     

Solution behaviour of a liquid-crystalline side-group polymer

Dilute and semidilute solutions of fractions of a liquid-crystalline side-group polymer were investigated by means of size-exclusion chromatography (SEC), static light scattering (LS), density and viscosity measurements. The mass-average molar mass ranged from M?_w = 1 · 10⁵ g · mol^?1 to 1,5 · 10⁶ g · mol^?1. Large discrepancies were found between the molar mass determined through SEC and through LS. Strong interactions between the mesogenic groups can be assumed by the results of density and LS measurements. Due to the determined characteristic ratio of C_∞ = 19,5 a similar chain stiffness as a poly(alkyl methacrylate) of equal length of the side chain is observed. In semidilute solutions an excess low-angle scattering (ExLAS) occurs which increases at higher concentrations. The dependence of the reduced osmotic modulus [M?_w/(RT)](?π/?c)_T on the parameter x = A₂ · M?_W · c was studied.     

Étude cinétique de la polymérisation anionique du styrène en présence d'un contre-ion baryum

The anionic polymerization of styrene in tetrahydrofuran initiated by a bifunctional organo-barium derivative shows a remarkable property: for a given temperature the propagation rate does not depend on carbanion concentration in the range from 3.10^?5 to 5.10^?3 mol/l. This corresponds to a linear relationship between the rate constant of propagation k_p and the reciprocal of active sites concentration. The activation energy of propagation is equal to 4,1 kcal/mol (17,1±1,3 kJ/mol). Our experimental results were interpreted assuming that “living” polymer molecules form rings, their two anionic ends being associated through a divalent cation, and that they constitute aggregates with a “rosace” type structure. The validity of this assumption is supported by spectral and viscosimetric studies of living polymer solutions.     

Tissue microarray immunohistochemical expression analysis of mismatch repair (hMLH1 and hMSH2 genes) in endometrial carcinoma and atypical endometrial hyperplasia: relationship with microsatellite instability.

Alterations in the mismatch repair genes (hMLH1 and hMSH2) play an important role in the development of microsatellite instability in sporadic endometrial cancer. Tissue microarray technology allows molecular profiling of tumor samples at the DNA, RNA, and protein levels. We analyzed hMLH1 and hMSH2 expression by immunohistochemistry in a group of atypical endometrial hyperplasias (n = 10), endometrioid endometrial carcinomas (n = 58), and nonendometrioid endometrial carcinomas (n = 27) on tissue microarray. The results were correlated with microsatellite instability status as evaluated by BAT-25 and BAT-26. Overall, 29.4% of lesions showed microsatellite instability. Loss of nuclear hMLH1 and hMSH2 protein expression was seen in 22.3% and 6.5% of cases, respectively. Immunohistochemistry for hMLH1 and hMSH2 showed lack of protein expression in 64% and 16.6% of microsatellite instability-positive endometrial lesions, respectively. Taken together, hMLH1 or hMSH2 protein expression was absent in 18 of 24 microsatellite instability-positive cases (75% sensitivity). A high level of concordance was found between immunohistochemistry for hMLH1 and hMSH2 and microsatellite instability status evaluated by BAT-25 and BAT-26 (kappa value of 0.7). Of the 57 cases found to be microsatellite instability negative, 53 showed normal expression of both proteins (93% specificity). The observed predictive value of absence of expression of hMLH1 for predicting microsatellite instability-positive status was 82%. The predictive value of normal expression of both proteins for predicting microsatellite instability-negative status was 90%. These results are consistent with those previously reported in whole tissue sections. Therefore, immunohistochemical analysis of hMLH1 and hMSH2 expression on tissue microarray provides an accurate technique for screening for tumors with microsatellite instability. Tissue microarrays represent an ideal approach for comparing different diagnostic or predictive markers with one another in consecutive tissue microarray sections.