The Raf-1 serine͞threonine kinase is a key protein involved in the transmission of many growth and developmental signals. In this report, we show that autoinhibition mediated by the noncatalytic, N-terminal regulatory region of Raf-1 is an important mechanism regulating Raf-1 function. The inhibition of the regulatory region occurs, at least in part, through binding interactions involving the cysteine-rich domain. Events that disrupt this autoinhibition, such as mutation of the cysteine-rich domain or a mutation mimicking an activating phosphorylation event (Y340D), alleviate the repression of the regulatory region and increase Raf-1 activity. Based on the striking similarites between the autoregulation of the serine͞threonine kinases protein kinase C, Byr2, and Raf-1, we propose that relief of autorepression and activation at the plasma membrane is an evolutionarily conserved mechanism of kinase regulation.

Background Recent studies indicate that short subclinical episodes of herpes simplex virus type 2 (HSV-2) are the predominant form of skin and mucosal viral shedding. We evaluated whether standard or high-dose antiviral therapy reduced the frequency of such shedding. Methods To determine whether short episodes of genital HSV shedding are suppressed on standard dose (SD) and high-dose (HD) antiviral therapy, HSV-2 seropositive, HIV seronegative persons in Seattle, WA were enrolled into three separate but complementary randomized, open-label, cross-over studies comparing 1) no medication to aciclovir 400 mg twice daily (SD-ACV), 2) valaciclovir 500 mg daily (SD-VAL) to aciclovir 800 mg three times daily (TID) (HD-ACV), and 3) SD-VAL to HD-VAL (1 gm TID). Study arms lasted 4–7 weeks, separated by one week wash-out. Participants obtained genital swabs four times daily for quantitative HSV DNA PCR. The primary endpoint was within-person comparison of shedding rate on each study arm. Results Of 113 participants randomized, 90 were eligible for analysis of the primary endpoint. Participants collected 23,605 swabs; of these 1272 (5·4%) had HSV detected. HSV shedding was significantly higher during the no medication arm (18·1% of swabs) compared with SD-ACV (1.2% of swabs, IRR=0·05, 95% CI=0·03–0·08). Breakthrough reactivations occurred on all doses (SD-ACV 1·2%, SD-VAL 5·2%, HD-ACV 4·2%, and HD-VAL 3·3% of swabs). HD-VAL was associated with less shedding compared with SD-VAL (IRR=0·54, 95% CI=0·44–0·66), likely due to more rapid clearance of mucosal HSV (4·7 logs/6 hours on HD-VAL vs. 4·4 logs/6 hours on SD-VAL, (p=0·02)). However, the annualized breakthrough episodes was similar on SD-VAL (22·6) and HD-ACV (20·2, p=0·54) and SD-VAL (14.9) and HD-VAL (16·5, p=0·34). Regardless of dose, breakthrough episodes were short (median 7–10 hours) and 80% were subclinical. Studies were not designed to make inter-trial comparisons between antiviral doses. Except for increased incidence of headaches on HD-VAL, all regimens were well-tolerated. Conclusions Short bursts of subclinical genital HSV reactivation are frequent, even during high-dose antiherpes therapy, and likely account for continued transmission of HSV-2 during suppressive antiviral therapy. More potent antiviral therapy is needed to abolish HSV-2 transmission

Background. Bacterial vaginosis (BV) represents shifts in microbiota from Lactobacillus spp. to diverse anaerobes. Although antibiotics relieve symptoms and temporarily eradicate BV-associated bacteria (BVAB), BV usually recurs. We investigated the role of extravaginal BVAB reservoirs in recurrence.Methods. Risks for BV acquisition over the course of 1 year were defined. DNA in vaginal, anal, and oral swab samples from enrollment was subjected to quantitative polymerase chain reaction assays targeting 16S ribosomal RNA genes of Gardnerella vaginalis, Lactobacillus crispatus, BVAB1, BVAB2, BVAB3, Megasphaera spp., Lactobacillus jensenii, and Leptotrichia/Sneathia spp. A case-control approach analyzed BVAB detection at enrollment for case patients (BV acquisition) versus controls (none).Results. Of 239 women enrolled without BV, 199 were seen in follow-up, and 40 experienced BV; 15 had all samples for analysis. Detection of G. vaginalis in oral cavity or anal samples and Leptotrichia/Sneathia spp. in anal samples was more common at enrollment among case patients, who also had higher concentrations of these bacteria and Megasphaera relative to 30 controls at each site. In contrast, L. crispatus was detected more frequently in anal samples among controls.Conclusions. Women who acquire BV are more likely have previous colonization of extravaginal reservoirs with some BVAB, and less likely to have L. crispatus, suggesting that BVAB may be acquired vaginally from extravaginal reservoirs.

IntroductionKaposi sarcoma (KS) is the leading cause of cancer in Uganda and occurs in people with and without HIV. Human herpesvirus-8 (HHV-8) replication is important both in transmission of HHV-8 and progression to KS. We characterized the sites and frequency of HHV-8 detection in Ugandans with and without HIV and KS.MethodsParticipants were enrolled into one of four groups on the basis of HIV and KS status (HIV negative/KS negative, HIV positive/KS negative, HIV negative/KS positive, and HIV positive/KS positive). Participants collected oral swabs daily and clinicians collected oral swabs, anogenital swabs, and plasma samples weekly over 4 weeks. HHV-8 DNA at each site was quantified by polymerase chain reaction (PCR).Results78 participants collected a total of 2063 orals swabs and 358 plasma samples. Of these, 428 (21%) oral swabs and 96 (27%) plasma samples had detectable HHV-8 DNA. HHV-8 was detected more frequently in both the oropharynx of persons with KS (24 (57%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p = 0.002) and the peripheral blood (30 (71%) of 42 persons with KS vs. 8 (22%) of 36 persons without, p<0.001). In a multivariate model, HHV-8 viremia was more frequent among men (IRR = 3.3, 95% CI = 1.7–6.2, p<0.001), persons with KS (IRR = 3.9, 95% CI = 1.7–9.0, p = 0.001) and persons with HIV infection (IRR = 1.7, 95% CI = 1.0–2.7, p = 0.03). Importantly, oral HHV-8 detection predicted the subsequent HHV-8 viremia. HHV-8 viremia was significantly more common when HHV-8 DNA was detected from the oropharynx during the week prior than when oral HHV-8 was not detected (RR = 3.3, 95% CI = 1.8–5.9 p<0.001). Genital HHV-8 detection was rare (9 (3%) of 272 swabs).ConclusionsHHV-8 detection is frequent in the oropharynx and peripheral blood of Ugandans with endemic and epidemic KS. Replication at these sites is highly correlated, and viremia is increased in men and those with HIV. The high incidence of HHV-8 replication at multiple anatomic sites may be an important factor leading to and sustaining the high prevalence of KS in Uganda.

Background Patients with newly acquired genital HSV-2 infection have virus frequently detected at the genital mucosa. Rates of genital shedding initially decrease over time after infection, but data on long-term viral shedding are lacking. Methods 377 healthy adults with history of symptomatic genital HSV-2 infection collected anogenital swabs for HSV-2 DNA PCR for at least 30 consecutive days. Results Time since first genital herpes episode was significantly associated with reduced genital shedding. Total HSV shedding occurred on 33.6% of days in participants <1 year, 20.6% in those 1–9 years, and 16.7% in those ≥10 years from first episode. Subclinical HSV shedding occurred on 26.2% of days among participants <1 year, 13.1% in those 1–9 years, and 9.3% in those ≥10 years from first episode. On days with HSV detected, mean quantity was 4.9 log10 copies/mL for those <1 year, 4.7 log10 copies/mL among those 1–9 years, and 4.6 log10 copies/mL among those ≥10 years since first episode. Conclusions Rates of total and subclinical HSV-2 shedding decrease after the first year following the initial clinical episode. However, viral shedding persists at high rates and copy numbers years after infection, and therefore may pose continued risk of HSV-2 transmission to sexual partners.

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IntroductionThe incidence of Kaposi sarcoma (KS) has increased dramatically among women in sub-Saharan Africa since the onset of the HIV pandemic, but data on KS disease in women are limited. To identify gender-related differences in KS presentation and outcomes, we evaluated the clinical manifestations and response in men and women with AIDS-associated KS in Uganda.Methods and FindingsHIV-infected adults with KS attending the Infectious Diseases Institute (IDI) and Uganda Cancer Institute (UCI) in Kampala, Uganda between 2004 and 2006 were included in a retrospective cohort. Evaluation of KS presentation was based on the clinical features described at the initial KS visit. Response was evaluated as the time to “improvement”, as defined by any decrease in lesion size, lesion number, or edema. The cohort consisted of 197 adults with HIV and KS: 55% (108/197) were women. At presentation, the median CD4 T-cell count was significantly lower in women (58 cells/mm3; IQR 11–156 cells/mm3) than men (124 cells/mm3; IQR 22–254 cells/mm3) (p = 0.02). Women were more likely than men to present with lesions of the face (OR 2.8, 95% CI, 1.4, 5.7; p = 0.005) and hard palate (OR 2.0, 95% CI, 1.1, 3.7; p = 0.02), and were less likely than men to have lower extremity lesions (OR 0.54, 95% CI, 0.3, 0.99; p = 0.05). Women were less likely than men to demonstrate clinical improvement (HR = 0.52, CI 0.31, 0.88; p = 0.01) in multivariate analysis.ConclusionsThe clinical presentation and response of KS differs between men and women in Uganda. These data suggest that gender affects the pathophysiology of KS, which may have implications for the prevention, diagnosis, and treatment of KS in both men and women. Prospective studies are needed to identify predictors of response and evaluate efficacy of treatment in women with KS, particularly in Africa where the disease burden is greatest.

UDP-glucuronosyltransferase (UGT) 1A1 glucuronidates bilirubin, estrogens, and xenobiotic compounds. The UGT1A1*28 polymorphism results in lower promoter activity due to 7 thymine-adenine (TA) repeats, rather than the more common 6 TA repeats. Previously, we showed that serum bilirubin, a marker of UGT1A1 activity, was lower among individuals homozygous for the UGT1A1*28 polymorphism (7/7) when randomized to a high fruit and vegetable (F&V) diet, whereas no effect was seen in individuals with the wild-type (6/6) and heterozygous (6/7) genotypes. Our objective here was to determine if we could detect genotype-diet interactions on bilirubin concentrations in an observational study. Healthy non-smoking men (n=146) and women (n=147), recruited from the Seattle area, provided blood samples for genotyping and bilirubin measurements. We used multiple linear regression to assess the relationships between UGT1A1 genotype, bilirubin concentrations and consumption of specific F&V [cruciferous vegetables, citrus fruits, and soy foods (n=268)] based on FFQ, and F&V from 6 botanical families [Cruciferae, Rosaceae, Rutaceae, Umbelliferae, Solanaceae and Leguminosae (n=261)] based on 3 d food records. We observed a significant interaction of UGT1A1 genotype and citrus consumption among women. Women with the 7/7 genotype who consumed 0.5 or more daily servings of citrus fruit or foods from the Rutaceae botanical family had ~30% lower serum bilirubin than those with the same genotype who consumed less, while 6/6 and 6/7 genotypes did not differ by consumption (P for interaction = 0.006 and 0.03 respectively). These results suggest that citrus consumption may increase UGT1A1 activity among women with the 7/7 genotype.