A human papillomavirus E2 transcriptional activator. The interactions with cellular splicing factors and potential function in pre-mRNA processing

The human papillomavirus (HPV) E2 protein plays an important role in transcriptional regulation of viral genes as well as in viral DNA replication. Unlike most types of HPV, the E2 protein of epidermodysplasia verruciformis (EV)-associated HPVs harbors a relatively long hinged region between the terminal, conserved transactivation and DNA binding/dimerization domains. The sequence of EV-HPV E2 hinge contains multiple arginine/serine (RS) dipeptide repeats which are characteristic of a family of pre-messenger RNA splicing factors, called SR proteins. Here we show that the HPV-5 (an EV-HPV) E2 protein can specifically interact with cellular splicing factors including a set of prototypical SR proteins and two snRNP-associated proteins. Transiently expressed HPV-5 E2 protein colocalizes with a nuclear matrix associated-splicing coactivator in nuclear speckled domains. The RS-rich hinge is essential for E2 transactivator interaction with splicing factors and for its subnuclear localization. Moreover, we present functional evidence for the HPV-5 E2 transactivator, which shows that the RS-rich hinge domain of the E2 protein can facilitate the splicing of precursor messenger RNA made via transactivation by E2 itself. Our results, therefore, suggest that a DNA binding transactivator containing an RS-rich sequence can play a dual role in gene expression.

Novel patterns of p53 abnormality in breast cancer from Taiwan: experience from a low-incidence area

Among 114 breast cancers in Taiwan, the prevalence of p53 mutation (22.8%) and p53 accumulation (38.3%) was similar to that in high-incidence areas. However, novel patterns of p53 abnormalities, including unique sites or types of mutation (i.e. an excessive proportion of G:C to A:T transition at CpG site), and accumulation of wild-type p53 either within nuclear or cytoplasmic compartments were noted. These may have relevance to breast cancer in Taiwan, a low-incidence area.

The reallocation of body fat toward the abdomen persists to very old age, while body mass index declines after middle age in Chinese

OBJECTIVES

Age-specific distributions of several anthropometric measurements were examined to elucidate age-associated changes.

DESIGN

Community-based cross-sectional analysis, which was performed on anthropometric data collected from members of 2769 families from November 1991 to September 1993.

SUBJECTS

2776 Chinese men and 3176 non-pregnant Chinese women.

MEASUREMENTS

Age-specific values of several obesity indices, including a general obesity index (body mass index) and obesity indices at various parts of the body, including waist-to-hip ratio, waist circumference, hip circumference, arm circumference, triceps skinfold thickness and subscapular skinfold thickness.

RESULTS

The age-specific percentile values of weight, body mass index, arm circumference, triceps skinfold thickness, subscapular skinfold thickness and hip circumference showed a gradual increase with age up to middle age, but a decline subsequently. This 'up and then down' phenomenon occurred later in women than in men. On the other hand, age-specific percentile values of waist circumference and waist-to-hip ratio showed a steady increase with age from early life.

CONCLUSIONS

These data indicate that, in very old age, a greater amount of fat tends to accumulate in the abdominal region compared to the deposition in the younger age groups. This occurs despite a decrease in body weight and body mass index after middle age.

Seroprevalence and associated risk factors of Helicobacter pylori infection in Taiwan

In order to estimate the seroprevalence and explore multiple risk factors associated with Helicobacter pylori infection among residents in Taiwan, a total of 823 subjects randomly selected from one metropolitan precinct and three townships were studied. Serum samples were tested for IgG antibodies against H. pylori by enzyme-linked immunosorbent assay using commercial kits. The overall seropositive rate was 54.4% with no gender difference (53.7% for males and 55.2% for females). There was a significant geographical variation with the highest seropositive rate (63.4%) in rural area where aborigines live, and where the age-adjusted stomach cancer mortality is highest and the lowest (40.5%) in urban area where Hakkas live, and where the stomach cancer mortality is lowest. There was also an increasing seropositive rate with age from 27.1% for children younger than 10 years old to 72.3% for adults aged more than 40 years old. Age-specific seroprevalence in Taiwan is higher than that in United States, France, Finland and Australia, and lower than that in Algeria, Ivory Coast and India. No association with H. pylori seropositivity was observed for drinking water source, toilet type, family income and educational level after adjusting for age and area. A dose-response relation between H. pylori seropositivity and sibship size was found. Upon further analysis of seroprevalence for children aged 16 or younger, a positive association was observed for birth order and current number of children in family; there was also an inverse association for current number of adults in family. The early childhood transmission among siblings seems an important determinant of H. pylori seropositivity in Taiwan.