Publications

BACKGROUND

The incidence and prevalence of sexually transmitted infections (STI) and other reproductive tract infections (RTI) is high in much of the developing and parts of the developed worlds. STIs and RTIs are associated with the vaginal transmission of HIV. Additional strategies to improve STI control are needed, and vaginal microbicides are a possible strategy. One potential vaginal microbicide is the widely used spermicide, nonoxynol-9 (N-9).

OBJECTIVES

To determine the safety and effectiveness of N-9 in preventing vaginal acquisition of sexual transmitted infections (exclusive of HIV) by women from men.

SEARCH STRATEGY

Systematic search of electronic databases, conference abstracts, reference lists of relevant studies and contact with experts and funders.

SELECTION CRITERIA

Randomised controlled trials meeting pre-determined quality criteria with STI as the outcome.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked by another.

MAIN RESULTS

Ten of 12 identified randomised controlled trials were included and findings among them were broadly consistent. In meta-analysis, the risks of gonorrhoea (relative risk [RR] 0.91, 95%CI 0.67-1.24), cervical infection (RR 1.01, 0.84-1.22), trichomoniasis (RR 0.84, 0.69-1.02), bacterial vaginosis (0.88, 0.74-1.04), chlamydia (RR 0.88, 0.77-1.01) and candidiasis (RR 0.97, 0.84-1.12) were not statistically significantly different in women receiving N-9 compared with placebo. Genital lesions were more common in the N-9 users (RR 1.17, 95%CI 1.02-1.35).

REVIEWER'S CONCLUSIONS

There is good evidence that nonoxynol-9 does not protect against sexually transmitted infections, and there is some evidence that it may be harmful by increasing the rate of genital ulceration. As such, this product cannot be recommended for STI prevention.

BACKGROUND

There is a need for female-controlled methods of HIV prevention. Vaginal microbicides, substances inserted into the vagina to prevent women acquiring HIV and sexually transmitted infections (STIs) from men, could be useful in this regard. One potential vaginal microbicide is the widely used spermicide, nonoxynol-9 (N-9).

OBJECTIVES

To determine the safety and effectiveness of N-9 in preventing vaginal acquisition of HIV infection by women from men.

SEARCH STRATEGY

Extensive searches of electronic databases, conference abstracts, reference lists of relevant studies and contact with experts and funders.

SELECTION CRITERIA

Randomised controlled trials meeting pre-determined quality criteria with HIV infection as the outcome.

DATA COLLECTION AND ANALYSIS

Data were extracted by one reviewer and checked by the another. Any discrepancies were adjudicated by a third reviewer.

MAIN RESULTS

Five trials were included in the review and four contributed to a meta-analysis. Overall, the risk of HIV infection was not statistically significantly different among women receiving N-9 (relative risk [RR] 1.12, 95% CI 0.88-1.42; p=0.4). The risk of genital lesions was statistically significantly greater among women receiving N-9 (RR 1.18, 95%CI 1.02-1.36; p=0.02).

REVIEWER'S CONCLUSIONS

There is no evidence that nonoxynol-9 protects against vaginal acquisition of HIV infection by women from men. There is evidence that it may do harm by increasing the frequency of genital lesions.

Coronary artery disease is the leading cause of death in the United States, thus the intense interest in a screening test that would allow early identification of coronary artery disease in its asymptomatic stage, allowing early aggressive targeted risk factor reduction. While office-based risk factor assessment is currently the reference standard for prediction of cardiac risk, several imaging tests are currently being investigated. Electron beam computed tomography (EBCT) can accurately identify calcium in the coronary tree noninvasively. Coronary calcium is clearly linked with coronary atherosclerosis. In population studies, populations with higher calcium scores have more calcium events. The predictive value of a calcium score for an individual is currently under investigation, as well as the incremental value of a calcium score over office-based risk assessment in cardiac risk prediction. This review looks at the current role of EBCT in the prevention of cardiovascular disease. It summarizes the current data for calcium as a screening tool, which is strongest in establishing that asymptomatic people undergo increased rates of revascularization after an EBCT test. Widespread clinical use of EBCT is not recommended, pending data to establish its efficacy in the role of risk factor reduction and prevention of cardiovascular disease.

Steatosis or fatty liver in individuals with human immunodeficiency virus (HIV) may result from HIV itself, the use of nucleoside analogues, concurrent infection with hepatitis B or C, alcohol use, diabetes mellitus, obesity, or combinations of these factors. Nucleoside analogues have been the focus of increasing concern, because several fatal cases of severe macrosteatosis, lactic acidosis, and hepatomegaly have been linked to the use of nucleoside analogues. Other classes of antiretroviral drugs, as well as opportunistic infections, can also cause hepatic injury without steatosis. The additive effect of these different risk factors, especially in the presence of underlying hepatic steatosis, likely contributes to the increased prevalence of hepatic abnormalities among HIV-infected individuals. The conditions under which some patients rapidly progress to hepatic failure and/or cirrhosis need to be defined. This is a US government work. There are no restrictions on its use.

Activators of peroxisome proliferator activated receptor-alpha, a nuclear hormone receptor that heterodimerizes with retinoid X receptor, stimulate epidermal differentiation and inhibit proliferation. Here we determined the anti-inflammatory effects of peroxisome proliferator activated receptor-alpha agonists in models of irritant and allergic contact dermatitis produced in mouse ears by topical treatment with 12-O-tetradecanoylphorbol-13-acetate and oxazalone, respectively. As expected, 12-O-tetradecanoylphorbol-13-acetate treatment resulted in a marked increase in the thickness and weight of the ears and provoked an inflammatory cell infiltrate in the dermis. Topical treatment with three different peroxisome proliferator activated receptor-alpha agonists, clofibrate, WY 14643, or linoleic acid, 45 min and 4 h after 12-O-tetradecanoylphorbol-13-acetate application, resulted in a marked decrease in ear thickness and weight and a reduction in the number of inflammatory cells in the dermis. The reduction in inflammation by these peroxisome proliferator activated receptor-alpha agonists was of similar magnitude to that seen with a potent topical glucocorticoid, clobetasol. In contrast, stearic acid, a free fatty acid that does not activate peroxisome proliferator activated receptor-alpha, had no effect on the 12-O-tetradecanoylphorbol-13-acetate-induced inflammation. Moreover, clofibrate did not significantly alter ear thickness following 12-O-tetradecanoylphorbol-13-acetate treatment in peroxisome proliferator activated receptor-alpha-/- mice, indicating that the anti-inflammatory effect is mediated by peroxisome proliferator activated receptor-alpha. As tumor necrosis factor-alpha and interleukin-1alpha are major mediators of cutaneous inflammation we next used immunohistochemistry to determine whether the peroxisome proliferator activated receptor-alpha agonists reduce the levels of these cytokines in 12-O-tetradecanoylphorbol-13-acetate-treated skin. 12-O-tetradecanoylphorbol-13-acetate treatment resulted in an increase in tumor necrosis factor and interleukin-1alpha staining in the epidermis that was reduced by clofibrate treatment. Finally, clofibrate treatment also reduced ear thickness and weight in oxazalone-induced allergic dermatitis, a change that was accompanied by a reduction in inflammatory cells in the dermis and a decrease in tumor necrosis factor-alpha and interleukin-1alpha levels in the oxazalone-treated epidermis. These studies demonstrate that topically applied peroxisome proliferator activated receptor-alpha agonists possess receptor mediated, anti-inflammatory activity in both irritant and allergic contact dermatitis animal models. The anti-inflammatory properties of peroxisome proliferator activated receptor-alpha agonists, coupled with their anti-proliferative and pro-differentiating effects, suggest that they could be beneficial for the treatment of a variety of cutaneous diseases.

Liver X receptor-alpha and -beta are members of the nuclear hormone receptor superfamily that heterodimerize with retinoid X receptor and are activated by oxysterols. In recent studies we found that treatment of cultured human keratinocytes with oxysterolstimulated differentiation, as demonstrated by increased expression of involucrin and transglutaminase, and inhibited proliferation. The aims of this study were to determine: (i) whether oxysterols applied topically to the skin of mice induce differentiation in normal epidermis; (ii) whether this effect is mediated via liver X receptor-alpha and/or liver X receptor-beta; and (iii) whether oxysterols normalize epidermal morphology in an animal model of epidermal hyperplasia. Topical treatment of normal hairless mice with 22(R)-hydroxycholesterol or 24(S),25-epoxycholesterol resulted in a decrease in epidermal thickness and a decrease in keratinocyte proliferation assayed by proliferating cell nuclear antigen staining. Moreover, oxysterol treatment increased the levels of involucrin, loricrin, and profilaggrin protein and mRNA in the epidermis, indicating that oxysterols stimulate epidermal differentiation. Additionally, topical oxysterol pretreatment improved permeability barrier homeostasis. Whereas liver X receptor-alpha-/- mice revealed no alterations in epidermal differentiation, the epidermis was thinner in liver X receptor-beta-/- mice than in wild-type mice, with a reduced number of proliferating cell nuclear antigen positive cells and a modest reduction in the expression of differentiation markers. Topical oxysterol treatment induced differentiation in liver X receptor-alpha-/- mice whereas in liver X receptor-beta-/- mice there was no increase in the expression of differentiation markers. Whereas both liver X receptor-alpha and liver X receptor-beta are expressed in cultured human keratinocytes and in fetal rat skin, only liver X receptor-beta was observed on northern blotting in adult mouse epidermis. Finally, treatment of hyperproliferative epidermis with oxysterols restored epidermal homeostasis. These studies demonstrate that epidermal differentiation is regulated by liver X receptor-beta and that oxysterols, acting via liver X receptor-beta, can induce differentiation and inhibit proliferation in vivo. The ability of oxysterols to reverse epidermal hyperplasia suggests that these agents could be beneficial for the treatment of skin disorders associated with hyperproliferation and/or altered differentiation.

The vertebrate heart responds to hemodynamic load with the enlargement of postmitotic, terminally differentiated cardiac myocytes. Such hypertrophic changes are characterized by alterations in sarcomeric organization and gene expression. Previously, we established a role for a nonreceptor tyrosine kinase, focal adhesion kinase, in signaling the changes in cytoskeletal organization associated with hypertrophy. Here, we report on data supporting a key role for p130Cas in this process. In neonatal cardiac myocytes FAK, Cas and paxillin are located in sarcomeric Z-lines, suggesting that the Z-line is an important signaling locus in these cells. The expression of different Cas mutants results in a nearly complete loss of sarcomeric organization in these myocytes. Moreover, expression of the C-terminal focal adhesion-targeting domain of FAK both disrupted sarcomeric organization and interfered with the localization of endogenous Cas to Z-lines. These findings suggest that the association of FAK and Cas and the preservation of multiple protein-interaction motifs of Cas are required for the correct assembly of sarcomeres in cardiac myocytes.

Inhibition of alphavbeta3 or alphavbeta5 integrin function has been reported to suppress neovascularization and tumor growth, suggesting that these integrins are critical modulators of angiogenesis. Here we report that mice lacking beta3 integrins or both beta3 and beta5 integrins not only support tumorigenesis, but have enhanced tumor growth as well. Moreover, the tumors in these integrin-deficient mice display enhanced angiogenesis, strongly suggesting that neither beta3 nor beta5 integrins are essential for neovascularization. We also observed that angiogenic responses to hypoxia and vascular endothelial growth factor (VEGF) are augmented significantly in the absence of beta3 integrins. We found no evidence that the expression or functions of other integrins were altered as a consequence of the beta3 deficiency, but we did observe elevated levels of VEGF receptor-2 (also called Flk-1) in beta3-null endothelial cells. These data indicate that alphavbeta3 and alphavbeta5 integrins are not essential for vascular development or pathological angiogenesis and highlight the need for further evaluation of the mechanisms of action of alphav-integrin antagonists in anti-angiogenic therapeutics.

OBJECTIVE

There has been a recent proliferation of medical reference texts intended to guide practitioners whose patients use herbal therapies. We systematically assessed six herbal reference texts to evaluate the information they contain on herbal toxicity.

METHODS

We selected six major herbal references published from 1996 to 2000 to evaluate the adequacy of their toxicological information in light of published adverse events. To identify herbs most relevant to toxicology, we reviewed herbal-related calls to our regional California Poison Control System, San Francisco division (CPCS-SF) in 1998 and identified the 12 herbs (defined as botanical dietary supplements) most frequently involved in these CPCS-SF referrals. We searched Medline (1966 to 2000) to identify published reports of adverse effects potentially related to these same 12 herbs. We scored each herbal reference text on the basis of information inclusiveness for the target 12 herbs, with a maximal overall score of 3.

RESULTS

The herbs, identified on the basis of CPCS-SF call frequency were: St John's wort, ma huang, echinacea, guarana, ginkgo, ginseng, valerian, tea tree oil, goldenseal, arnica, yohimbe and kava kava. The overall herbal reference scores ranged from 2.2 to 0.4 (median 1.1). The Natural Medicines Comprehensive Database received the highest overall score and was the most complete and useful reference source. All of the references, however, lacked sufficient information on management of herbal medicine overdose, and several had incorrect overdose management guidelines that could negatively impact patient care.

CONCLUSION

Current herbal reference texts do not contain sufficient information for the assessment and management of adverse health effects of botanical therapies.

The ability of HIV-1 to evade the host immune response leads to the establishment of chronic infection. HIV-1 has been reported to up-regulate MHC I molecules on the surface of thymocytes from HIV-1-infected thymus. We demonstrate in this study that HIV-1 up-regulates MHC I on both HIV-1-infected and uninfected thymocytes in a manner that is independent of Nef, proportional to viral replication, and entirely mediated by IFN-alpha. IL-3Ralpha+ type 2 predendritic cells (preDC2) resident in the thymic medulla secrete IFN-alpha, which acts on IFN-alphabetaR-expressing immature thymocytes to induce MHC I expression. Furthermore, thymic preDC2 are permissive for HIV-1 infection and positive for intracellular p24. These data demonstrate the ability of IFN-alpha secreted by preDC2 to induce MHC I up-regulation in the HIV-1-infected human thymus.