Seasonal Abundance and Species Diversity of Adult Tabanidae (Diptera) at Lake Lansing Park-North, Michigan

A two year study was undertaken to determine the seasonal abundance and diversity of adult deer flies and horse flies, to compare two methods of sampling (Malaise trap and sweep net), and to estimate attack rates by tabanids on people at Lake Lansing Park-North, Ingham County, Michigan, in 1990 and 1991. Tabanids were sampled using dry ice-baited Malaise traps, and by making over- head sweeps with a standard insect net while hiking a trail. Hybomitra spp. (299 individuals of 9 species) peaked in abundance in mid-May to early June in both years. Chrysops spp. (11,675 individuals of 14 species) and Tabanus spp. (324 individuals of 8 species) peaked in early-to late-July in both study years. Peak abundance for Chrysops and Tabanus spp. occurred earlier in 1991 than 1990, probably because the spring of 1991 was warmer. There were six new species records for County. More individual Hybomitra and Tabanus were taken by M traps (77.3% for Hybomitra; 76.2% for Tabanus) than by netting (22.7% for Hybomitra; 23.8% for Tabanus). In contrast, sweep netting yielded more individual Chrysops (98.3%) than Malaise traps (1.7%). Tabanid attack rates on people hiking the trail exceeded 1,000 per hour on one occasion each year, at mid-season

The relation of plasmacytoid dendritic cells (pDCs) and regulatory t-cells (Tregs) with HPV persistence in HIV-Infected and HIV-Uninfected women

Other than CD4+ count, the immunologic factors that underlie the relationship of HIV/AIDS with persistent oncogenic HPV (oncHPV) and cervical cancer are not well understood. Plasmacytoid dendritic cells (pDCs) and regulatory T-cells (Tregs) are of particular interest. pDCs have both effector and antigen presenting activity and, in HIV-positive patients, low pDC levels are associated with opportunistic infections. Tregs downregulate immune responses, and are present at high levels in HIV-positives. The current pilot study shows for the first time that low pDC and high Treg levels may be significantly associated with oncHPV persistence in both HIV-positive and HIV-negative women. Larger studies are now warranted

Insulin-Like Growth Factor Axis and Risk of Type 2 Diabetes in Women

IGF-I shares structural homology and in vitro metabolic activity with insulin. Laboratory models suggest that IGF-I and its binding proteins IGFBP-1 and IGFBP-2 have potentially beneficial effects on diabetes risk, whereas IGFBP-3 may have adverse effects. We therefore conducted a prospective nested case-control investigation of incident diabetes (n = 742 case subjects matched 1:1 to control subjects) and its associations with IGF-axis protein levels in the Nurses’ Health Study, a cohort of middle-aged women. The median time to diabetes was 9 years. Statistical analyses were adjusted for multiple risk factors, including insulin and C-reactive protein. Diabetes risk was fivefold lower among women with baseline IGFBP-2 levels in the top versus bottom quintile (odds ratio [OR]q5–q1 = 0.17 [95% CI 0.08–0.35]; P trend < 0.0001) and was also negatively associated with IGFBP-1 levels (ORq5–q1 = 0.37 [0.18–0.73]; P trend = 0.0009). IGFBP-3 was positively associated with diabetes (ORq5–q1 = 2.05 [1.20–3.51]; P trend = 0.002). Diabetes was not associated with total IGF-I levels, but free IGF-I and diabetes had a significant association that varied (P interaction = 0.003) by insulin levels above the median (ORq5–q1 = 0.48 [0.26–0.90]; P trend = 0.0001) versus below the median (ORq5–q1 = 2.52 [1.05–6.06]; P trend < 0.05). Thus, this prospective study found strong associations of incident diabetes with baseline levels of three IGFBPs and free IGF-I, consistent with hypotheses that the IGF axis might influence diabetes risk

Association of Chronic Hepatitis C Infection With T-Cell Phenotypes in HIV-Negative and HIV-Positive Women

Background: Hepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4 + count). Methods: We used fresh blood from HIV-positive and at-risk HIVnegative women, with and without chronic HCV, to measure percentages of activated CD4 + and CD8 + T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic. Results: In multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4 + (P = 0.03), 33% more EM CD4 + (P = 0.0002), and 37% fewer central memory CD8 + (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4 + among HCV viremic women. Furthermore, the association with EM CD4 + among HIV positives was limited to individuals with diminished immune status (total CD4 + count #500 cells/mL), as were associations of HCV viremia with higher percentages of activated CD4 + and Tregs. Among HIV positives with high CD4 + count, no significant associations were observed. Conclusions: These data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4 + count

Association of Chronic Hepatitis C Infection With T-Cell Phenotypes in HIV-Negative and HIV-Positive Women

BackgroundHepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4⁺ count).MethodsWe used fresh blood from HIV-positive and at-risk HIV-negative women, with and without chronic HCV, to measure percentages of activated CD4⁺ and CD8⁺ T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic.ResultsIn multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4⁺ (P = 0.03), 33% more EM CD4⁺ (P = 0.0002), and 37% fewer central memory CD8⁺ (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4⁺ among HCV viremic women. Furthermore, the association with EM CD4⁺ among HIV positives was limited to individuals with diminished immune status (total CD4⁺ count ≤500 cells/μL), as were associations of HCV viremia with higher percentages of activated CD4⁺ and Tregs. Among HIV positives with high CD4⁺ count, no significant associations were observed.ConclusionsThese data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4v count

Relationship of prediagnostic body mass index with survival after colorectal cancer: Stage‐specific associations

Higher body mass index (BMI) is a well-established risk factor for colorectal cancer (CRC), but is inconsistently associated with CRC survival. In 6 prospective studies participating in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), 2,249 non-Hispanic white CRC cases were followed for a median 4.5 years after diagnosis, during which 777 died, 554 from CRC-related causes. Associations between prediagnosis BMI and survival (overall and CRC-specific) were evaluated using Cox regression models adjusted for age at diagnosis, sex, study and smoking status (current/former/never). The association between BMI category and CRC survival varied by cancer stage at diagnosis (I-IV) for both all-cause (p-interaction = 0.03) and CRC-specific mortality (p-interaction = 0.04). Compared to normal BMI (18.5-24.9 kg/m(2) ), overweight (BMI 25.0-29.9) was associated with increased mortality among those with Stage I disease, and decreased mortality among those with Stages II-IV disease. Similarly, obesity (BMI ≥30) was associated with increased mortality among those with Stages I-II disease, and decreased mortality among those with Stages III-IV disease. These results suggest the relationship between BMI and survival after CRC diagnosis differs by stage at diagnosis, and may emphasize the importance of adequate metabolic reserves for colorectal cancer survival in patients with late-stage disease