Phosphorylation of serum response factor by casein kinase II: evidence against a role in growth factor regulation of fos expression

With the sequencing of the first complete eukaryotic chromosome, III of yeast (YCIII) of length 315 kb, several types of questions concerning chromosomal organization and the heterogeneity of eukaryotic DNA sequences can be approached. We have undertaken extensive analysis of YCIII with the goals of: (1) discerning patterns and anomalies in the occurrences of short oligonucleotides; (2) characterizing the nature and locations of significant direct and inverted repeats; (3) delimiting regions unusually rich in particular base types (e.g., G+C, purines); and (4) analyzing the distributions of markers of interest, e.g., delta (delta) elements, ARS (autonomous replicating sequences), special oligonucleotides, close repeats and close dyad pairings, and gene sequences. YCIII reveals several distinctive sequence features, including: (i) a relative abundance of significant local and global repeats highlighting five genes containing substantial close or tandem DNA repeats; (ii) an anomalous distribution of delta elements involving two clusters and a long gap; (iii) a significantly even distribution of ARS; (iv) a relative increase in the frequency of T runs and AT iterations downstream of genes and A runs upstream of genes; and (v) two regions of complex repetitive sequences and anomalous DNA composition, 29000-31000 and 291000-295000, the latter centered at the HMRa locus. Interpretations of these findings for chromosomal organization and implications for regulation of gene expression are discussed.     

Evidence for a stimulatory role of follicle-stimulating hormone on the spermatogonial population in adult males

Inactivation of the integrin beta6 subunit gene in mice resulted in an unexpected phenotype-functionally significant inflammation of the skin and lungs. These findings suggested a role for ligation of the alphav beta6 integrin on epithelial cells in downregulating epithelial inflammation. However, the results of gene inactivation could have been due to inactivation of adjacent genes and provided no information about the role of this integrin in specific populations of epithelial cells. In the current study, we used transgenic mice constitutively expressing the human beta6 subunit in alveolar type II cells and bronchiolar epithelial cells to examine directly the significance of alphav beta6 in these cells. Expression of this transgene largely inhibited the increases in airspace lymphocytes and macrophages and the lymphocyte and macrophage activation caused by inactivation of the beta6 subunit gene, and reduced the peribronchial and perivascular accumulations of lymphocytes. In the genetically mixed mice used for this study, we identified airway eosinophilia as an additional effect of beta6 inactivation. This effect was also partially inhibited by limited expression of the human transgene. These results definitively identify a role for distal lung epithelial alphav beta6 in downregulating pulmonary inflammation and suggest that interventions augmenting beta6 expression or function in these cells could influence the course of inflammatory lung diseases.     

An auxiliary peptide required for the function of two activation domains in upstream stimulatory factor 2 (USF2) transcription factor

OBJECTIVE: In adolescents, conduct disorder (CD), attention deficit hyperactivity disorder (ADHD), and depression are frequently comorbid with substance dependence (SD). We hypothesized that the prevalence and severity of CD, major depressive disorder (MDD), and ADHD would differ by gender, and that these conditions would associate differentially with severity of SD in males and females. METHODS: We examined these issues, using standardized diagnostic interviews, in 285 male and 82 female adolescents referred for comorbid CD and SD. RESULTS: Males and females did not differ significantly in severity of substance involvement, MDD, or ADHD, but males had more severe CD. MDD severity was the only variable significantly associated with SD severity for females, while for males, severity of CD combined with MDD and ADHD was significantly associated with SD severity. CONCLUSIONS: Among referred adolescents, CD, MDD, and ADHD may all be important concomitants of SD in males, while in females, depression may be the primary variable related to SD.     

Hepatocyte growth factor expression in the developing myocardium: evidence for a role in the regulation of the mesenchymal cell phenotype and urokinase expression

BACKGROUND: No previous studies have examined the extent to which correctional facilities in the United States screen for and treat hepatitis C (HCV) infection. METHODS: Medical directors of state correctional facilities responded to a survey assessing the degree to which prisons screen for and treat hepatitis C. To estimate numbers of inmates eligible for interferon treatment and to examine costs associated with HCV management, we constructed a feasibility model that incorporated screening criteria used in California and Rhode Island. RESULTS: Thirty-six states and Washington, DC, responded, resulting in a survey response rate of 73%, representing 77% of all inmates in state facilities nationwide. Colorado alone reported routine screening. Only California reported conducting a systematic seroprevalence study, which found that 39.4% of male inmates were hepatitis C antibody positive in 1994. Seventy-three percent of the respondents sometimes consider treating with interferon. Four states follow a standard protocol. The feasibility model suggests that treating suitably screened inmates is a reasonable expenditure for correctional systems. CONCLUSION: Prison may be an appropriate setting for treatment of hepatitis C. If accompanying substance abuse issues are addressed, instituting HCV treatment for certain eligible incarcerated individuals may be a worthy target for public health dollars.     

The 3'' untranslated region of the carcinoembryonic antigen gene plays a minimal role in the regulation of gene expression

Hospital workers are occupationally exposed to various agents known or suspected to induce chromosome damage, the most studied being ionizing radiation. To determine the extent of chromosome damage in peripheral blood lymphocytes in this population, taking into account temporal changes and job titles, a re-analysis of cytogenetic studies performed in four Italian laboratories in the period 1965-1993 was carried out. A total of 871 hospital workers and 617 controls, mainly coming from ad hoc studies or surveillance programs in occupational groups potentially exposed to ionizing radiation, were examined. The exposed to controls frequency ratio of chromosome aberrations was evaluated as the measure of effect within each dataset by job title, using multivariate Poisson regression analysis, which allowed an efficient control of confounding. Increased frequency of chromosome-type aberrations among exposed subjects was found in all datasets, especially in those dealing with older data. Significantly higher frequencies are reported for various job titles, particularly for orthopedists, radiologists, anesthesists, and nurses among paramedical occupations. Decrease in exposure to ionizing radiation in hospital workers was documented through a targeted study in the critical group of radiologists. A similar time-related reduction in the frequency of chromosome-type aberrations also has been reported by the surveillance studies carried out over the most recent decades. These data substantiate the use of chromosome-type aberrations as biomarkers of exposure in this occupational setting in the period evaluated. However, the increases observed also in workers with doubtful exposure to ionizing radiation indicate that other chromosome-damaging agents may be involved and, in turn, suggest the extension of surveillance to a larger number of occupations.     

Evidence against a direct role for the induction of c-jun expression in the mediation of drug-induced apoptosis in human acute leukemia cells

Previous reports have demonstrated that a variety of anticancer drugs, e.g., 1-beta-D-arabinofuranosylcytosine (ara-C), mitoxantrone, etoposide, camptothecin, and cisplatin, induce the expression of c-jun oncogene in leukemic cells prior to producing internucleosomal DNA fragmentation and the morphological features of apoptosis. This has led to the impression that the induction of c-jun expression may be directly involved in the molecular signaling of the final common pathway of programmed cell death or apoptosis. In the present study, we examined the role of c-jun expression in three different settings of anticancer drug-induced apoptosis in human leukemic cells. First, exposure of human myeloid leukemia HL-60 cells to high-dose ara-C for 4 h produced internucleosomal DNA fragmentation preceded by c-jun induction. However, pretreatment of HL-60 cells with staurosporine, a protein kinase C inhibitor, repressed c-jun yet enhanced DNA fragmentation and apoptosis due to ara-C. Second, in human pre-B leukemia 697/BCL-2 cells which are transfected with the cDNA of the bcl-2 oncogene and overexpress p26BCL-2, although ara-C or mitoxantrone treatment caused greater c-jun induction than in the 697/neo cells, significantly reduced endonucleolytic DNA fragmentation and apoptosis was observed in 697/BCL-2 cells. Finally, taxol-induced internucleosomal DNA fragmentation and morphological features of apoptosis in HL-60 cells were not associated with the induction of c-jun expression. These lines of evidence indicate that the induction of c-jun expression may not have a direct role in the molecular signaling of anticancer drug-induced apoptosis, and that the anticancer drug-induced apoptosis can occur by a mechanism that does not involve the induction of c-jun expression.     

Evidence for a tropic role of brain-derived neurotrophic factor in transplanted embryonic retinae

Developing retinal axons must follow a stereotypic course directing them to the subcortical visual centres which on arrival they must recognise. Transplantation studies suggest that local substrate cues close to the surface of the brainstem and diffusible factors emanating from the target region are important. To test a role for diffusible factors, we transplanted retinae to the cerebral cortex and have shown that outgrowth can be promoted by BDNF secreting fibroblasts.