Anti-retroviral Therapy Based HIV Prevention Among a Sample of Men Who Have Sex with Men in Cape Town, South Africa: Use of Post-exposure Prophylaxis and Knowledge on Pre-exposure Prophylaxis.

Men who have Sex with Men (MSM) have been affected disproportionately by the global HIV pandemic. Rates of consistent condom-use are low and there is a need for further biomedical prevention interventions to prevent new HIV infections. Post exposure prophylaxis (PEP) can reduce the risk of HIV, but uptake among MSM is low. Pre-exposure prophylaxis (PrEP), an innovative anti-retroviral-based HIV prevention tool might be an appropriate intervention for MSM who have recently accessed PEP that involves HIV negative individuals taking daily tenofovir+emtricitabine for HIV prevention. 44 MSM, attending a primary health-care level MSM-focused sexual health clinic in Cape Town, South Africa, who had initiated PEP were enrolled in this study. Participants were followed up after 2, 4 and 12 weeks. Self-administered electronic surveys were completed at the initial, 4 and 12 week visit. Barriers and facilitators to accessing PEP and remaining adherent were examined, as was knowledge about PrEP. Thirty-two participants (80 %) were <40 years of age (range 20-65 years). 35 % of the participants reported their reason for requiring PEP as condomless receptive anal intercourse. A further 20 % required PEP following condomless penetrative anal intercourse; 27.5 % required PEP due to a broken condom during receptive anal sex and 2 participants during insertive anal sex. Three participants did not complete 28 days of PEP or were lost to follow up. Over half (58.5 %) of the participants reported being completely adherent to their regime; under a third (31.7 %) reported missing one PEP dose; and 9.8 % reported missing more than one dose. 36/40 (90 %) had heard of PrEP and 30/40 (75 %) indicated that they would use PrEP if it were accessible to them. That we enrolled 44 MSM who accessed PEP from a Department of Health affiliated clinic over 12 months, speaks to the low uptake by MSM of PEP services in South Africa. Adherence was high and demonstrates that adherence support is feasible from a state health clinic. Reported risk behaviors in some high-risk participants did not change over time, demonstrating the need for additional longer-term HIV preventions such as PrEP. PEP users could conceivably be transitioned from PEP to PrEP.

Knowledge, Attitudes and Beliefs regarding Post Exposure Prophylaxis among South African Men who have Sex with Men.

The Soweto Men's Study (2008), demonstrated an overall HIV prevalence rate of 13.2 %, with 10.1 % among straight-identified Men-who-have-sex-with-men (MSM), 6.4 % among bisexual-identified MSM and 33.9 % among gay-identified MSM. Behavioral interventions are imperative, but insufficient to prevent new HIV infections. Biomedical prevention of HIV offers a variety of combination prevention tools, including Post-exposure prophylaxis (PEP). PEP studies amongst MSM have been conducted in Amsterdam, Brazil and San Francisco, but never before in Africa. A cross-sectional, Internet-based survey was initiated to measure knowledge, attitudes and beliefs regarding PEP among South African MSM. Recruitment commenced in June 2014 and ran until October 2015. Participants were recruited through banner advertisements on Facebook.com and mambaonline.com, advertisements in the local gay media and at Health4Men (H4M) MSM-targeted clinics. Outreach workers distributed flyers advertising the study in their local communities. The survey was also made available on a computer at the H4M clinics in Cape Town and Johannesburg to reach MSM who may not have Internet access. A total of 408 men completed the survey. The majority of these men were under the age of 40, identified as gay/homosexual and were employed; 51 % (208/408) self-identified as black or of mixed race. In multivariate analysis participants who identified as gay had greater odds of having previously heard of PEP (AOR 1.91, 95 % CI 1.04, 3.51; p = 0.036), as did those who reported their HIV status as positive (AOR 2.59, 95 % CI 1.47, 4.45; p = 0.001). Participants with medical insurance had greater odds of having used PEP previously (AOR 2.67, 95 % CI 1.11, 6.43; p = 0.029). Bivariate analysis showed that condomless sex in the past 6 months was not significantly associated with PEP knowledge (p = 0.75) or uptake (p = 0.56) of PEP. Our findings suggest a lack of PEP knowledge and uptake among non-gay identified, HIV negative and un-insured MSM. Focusing PEP programs on these men may potentially increase uptake. Increased knowledge needs to be provided to MSM who engage in risky sexual behaviors.

IRX-2, a novel immunotherapeutic, enhances and protects NK-cell functions in cancer patients.

BACKGROUND: IRX-2 is a primary biologic which has been used for the therapy of head and neck squamous cell cancer (HNSCC) with promising clinical results. Since NK-cell function is compromised in HNSCC patients, we tested the effects of IRX-2 on the restoration of human NK-cell functions in vitro. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated from 23 HNSCC patients and 10 normal controls (NC). The NK-cell phenotype and functions were compared before and after culture ± IRX-2 or ± 50 IU/ml rhIL-2. Flow cytometry was used to study the NK-cell phenotype, cytotoxic activity and cytokine expression. RESULTS: Impaired NK-cell cytotoxicity in HNSCC patients was related to lower expression of NKG2D, NKp30 and NKp46 receptors (P < 0.05) and not to a decreased frequency of NK cells. Incubation of patients' NK cells with IRX-2 up-regulated the percentage of receptor-positive NK cells (P < 0.05). It also up-regulated cytotoxicity of patients' NK cells (P < 0.01) more effectively than rhIL-2 (P < 0.01). IRX-2, but not rhIL-2, protected NK cells from suppression mediated by TGF-ß, and it restored (P < 0.05) expression of activating NK-cell receptors and NK-cell cytotoxicity suppressed by TGF-ß. Expression of pSMAD was decreased in NK cells treated with IRX-2 but not in those treated with rhIL-2. CONCLUSIONS: IRX-2 was more effective than IL-2 in enhancing NK-cell cytotoxicity and protecting NK-cell function of HNSCC patients in vitro, emphasizing the potential advantage of IRX-2 as a component of future therapies for HNSCC.

Administration of hepatitis A vaccine to a military population by needle and jet injector and with hepatitis B vaccine.

Military personnel are an important target population for hepatitis A immunization. Soldiers are often given vaccines by jet injector and may be required to receive multiple vaccines at one time. Formalin-inactivated hepatitis A vaccine containing 360 ELISA units of antigen was evaluated at Fort Campbell. Volunteers received vaccine at 0, 1, and 6 months as follows: group 1, hepatitis A vaccine by needle; group 2, hepatitis A vaccine by jet injector; group 3, hepatitis B vaccine by needle; and group 4, both hepatitis vaccines by needle in separate arms. Immune response and reactogenicity were evaluated. After two doses, recipients of vaccine administered by jet injector had a higher prevalence of antibody than those who received vaccine by needle (93% vs. 79%). By the 8th month, the vaccine was 100% immunogenic by either route or with hepatitis B vaccine. No interaction between hepatitis A and B vaccines was detected.

Comparative intestinal and testes toxicity of four aminothiols in irradiated and nonirradiated mice.

Intestinal and testicular toxicity in groups of nonirradiated and irradiated mice were investigated after intraperitoneal injection of aminothiol compounds or saline. Four aminothiols were studied. Three were prodrugs: WR-2721, WR-3689, and WR-151327 and one was the active form of WR-2721: WR-1065. Thirty minutes after injection, the mice were sham-irradiated or bilaterally exposed (whole body) to 60Co gamma-irradiation at a dose rate of 1 Gy per min to a total dose of 15 Gy. Four days after injection, mice were euthanised, and the intestines and testes were removed and histologically examined. The intestinal crypt cell number was increased in all the irradiated mice given WR-compounds compared to controls (P < 0.05). Interestingly, the crypt cell number in nonirradiated mice given WR-1065 was also greater than control or WR-2721 (P < 0.05) treated mice. Germinal cell numbers from testes of mice administered aminothiols prior to radiation decreased or did not change. Some swelling of the seminiferous tubules was also observed. The germinal cell numbers in sham-irradiated mice were also less than the controls. Thus, aminothiol addition can provide limited protection to intestinal crypt cells but not to germinal cells of the testes in response to gamma-irradiation. There is also evidence that aminothiols are toxic to the germinal cell layer of the seminiferous tubules when given to sham-irradiated mice.

Humoral immune responses in volunteers immunized with irradiated Plasmodium falciparum sporozoites.

Volunteers immunized with gamma-irradiated Plasmodium falciparum sporozoites serve as the gold standard for protective immunity against mosquito-borne malaria transmission and provide a relevant model for studying protective immune effector mechanisms. During a 7-12 month period, we immunized four volunteers via the bites of irradiated, infected mosquitoes. Following these exposures to attenuated sporozoites, all four volunteers developed antibodies to sporozoites as measured by an immunofluorescence assay and by an enzyme-linked immunosorbent assay using the circumsporozoite (CS) protein repeat-based molecule R32LR as capture antigen. Three volunteers also developed antibodies against the nonrepeating (flanking) regions of the CS protein; the level of these antibodies paralleled the serum activity to inhibit sporozoite invasion of hepatoma cells in vitro. These three volunteers were protected against malaria transmitted by the bites of five infected mosquitoes. Two of these protected volunteers received additional immunizing doses of irradiated sporozoites and were subsequently protected against challenge with a heterologous P. falciparum clone. No detectable fluctuations were observed in circulating levels of tumor necrosis factor, interferon-gamma, or interleukin-6 during the course of this study. Analysis of the humoral and cellular immune responses of these protected volunteers is expected to yield important clues to additional targets of immunity against the pre-erythrocytic stages of malaria parasites.

Pathological evaluation of WR-151327 administered orally in irradiated and non-irradiated male mice.

Studies were made on the radioprotective and toxic effects of orally administered WR-151327 in male CD2F1 mice. The lowest dose of orally administered drug permitting probit analysis of data was 450 mg per kg. The calculated radioprotective dose reduction factors (DRF) at 450 mg per kg and 900 mg per kg of body weight (BW) WR-151327 were 1.2 and 1.3, respectfully. Pathological examination at 8, 30 or 90 days post administration of 100, 450, or 900 mg per kg of the drug demonstrated that the major target organ for orally dosed mice was the testes. There was a decrease in the number of cells in the germinal cell layers of testes from animals administered 450 mg per kg WR-151327 or 10 Gy whole body irradiation after eight days. Moreover, there was a dramatic reduction in the germinal cells in mice seminiferous tubules treated with a combination of 450 mg per kg WR-151327 plus 10 Gy radiation after eight days.

Hepatitis A in the US Army: epidemiology and vaccine development.

Control of hepatitis A has been an important concern for US military forces in war and peace. Immune serum globulin, although effective, is exceedingly cumbersome to use. The prevalence of antibody against hepatitis A is decreasing in young American soldiers, putting them at risk of hepatitis A during deployment. The US Army has been an active participant in development of hepatitis A vaccine. The first successful cell-culture-derived, formalin-inactivated hepatitis A vaccine was developed at the Walter Reed Army Institute of Research. This prototype vaccine was shown, in 1986, to be safe and immunogenic for humans. Since then we have evaluated the following issues related to the use of inactivated hepatitis A vaccines in military populations. Immunogenicity of vaccine derived from the CLF and HM175 strains; immunogenicity of hepatitis A vaccine given by jet injector; immunogenicity of hepatitis A vaccine when given with hepatitis B vaccine; immunogenicity when given in shortened schedules; safety and immunogenicity in Thai children; and efficacy under field conditions in the tropics. The hepatitis A vaccines which we tested are safe and highly immunogenic. Immunization by jet gun confers immunity equivalent to immunization by needle. Hepatitis A vaccine is equally potent when given with hepatitis B vaccine. Data on rapid immunization schedules and efficacy are under evaluation. We conclude that hepatitis A vaccine is a major improvement in our ability to prevent hepatitis A in soldiers.

Liposomal malaria vaccine in humans: a safe and potent adjuvant strategy.

This study describes the safety and immunogenicity of a liposome-based vaccine injected into human subjects. Thirty healthy adult male volunteers were immunized with a liposome-encapsulated recombinant protein (R32NS181) containing epitopes from the repeat region of the circumsporozoite protein of Plasmodium falciparum. This antigen had previously been found to be poorly immunogenic in humans when it was adsorbed with Al(OH)3. In the present study, R32NS181 was encapsulated in liposomes containing monophosphoryl lipid A that were subsequently adsorbed to Al(OH)3. Increasing doses of liposomes containing antigen and monophosphoryl lipid A were used, but the liposomes were always adsorbed to the same dose of Al(OH)3. R32-specific serum IgG antibody responses to liposome-encapsulated R32NS181 were much higher than levels attained previously in humans with R32NS181 adsorbed to Al(OH)3. Geometric mean specific IgG levels after three doses ranged from 14 to 33 micrograms/ml. Sera from volunteers receiving the two highest doses inhibited P. falciparum sporozoite invasion of cultured hepatoma cells by an average of 92%, a result that was again superior to previously reported vaccines. Moderate but acceptable transient local reactogenicity was noted at high doses of the vaccine formulation, but little or no systemic toxicity was seen despite liposomal monophosphoryl lipid A doses up to 2200 micrograms. We conclude that encapsulation of poorly immunogenic circumsporozoite protein repeat peptides in monophosphoryl lipid A-containing liposomes is a successful adjuvant strategy in humans for inducing high levels of specific antibody production.

Use of adjuvant containing mycobacterial cell-wall skeleton, monophosphoryl lipid A, and squalane in malaria circumsporozoite protein vaccine.

Human immune responses to modern synthetic and recombinant peptide vaccines administered with the standard adjuvant, aluminum hydroxide, tend to be poor, hence the search for better adjuvants. Antibody responses to a Plasmodium falciparum circumsporozoite (CS) protein vaccine, R32NS1(81), administered with an adjuvant containing cell-wall skeleton of mycobacteria and monophosphoryl lipid A in squalane (MPL/CWS) have been compared to responses to the same immunogen administered with aluminum hydroxide. 2 weeks after the third dose the following indices were greater in the 5 patients who received MPL/CWS than in controls (p less than 0.05): the geometric mean concentration (2.0 vs 25.4 microgram/ml) and avidity index of antibodies to the P falciparum CS protein by ELISA, the geometric mean titre to P falciparum sporozoites by IFAT (1/115 vs 1/1600), and the geometric mean inhibition of sporozoite invasion of hepatoma cells in vitro (37.6 vs 90.3%). For R32NS1(81) MPL/CWS is superior to aluminum hydroxide as an adjuvant, and the data support the evaluation of this complex as an adjuvant for other vaccines.

Human cytotoxic T lymphocytes against the Plasmodium falciparum circumsporozoite protein.

Cytotoxic T lymphocytes (CTL) against the circumsporozoite (CS) protein of malaria sporozoites protect against malaria in rodents. Although there is interest in developing human vaccines that induce CTL against the Plasmodium falciparum CS protein, humans have never been shown to produce CTL against any Plasmodium species protein or other parasite protein. We report that when peripheral blood mononuclear cells (PBMC) from three of four volunteers immunized with irradiated P. falciparum sporozoites were stimulated in vitro with a recombinant vaccinia virus expressing the P. falciparum CS protein or a peptide including only amino acids 368-390 of the P. falciparum CS protein [CS-(368-390)], the PBMC lysed autologous Epstein-Barr virus-transformed B cells transfected with the P. falciparum CS protein gene or incubated with CS-(368-390) tricosapeptide. Activity was antigen specific, genetically restricted, and dependent on CD8+ T cells. In one volunteer, seven peptides reflecting amino acids 311-400 were tested, and, as in B10.BR mice, CTL activity was only associated with the CS-(368-390) peptide. Development of an assay for studying human CTL against the CS and other malaria proteins and a method for constructing target cells by direct gene transfection provide a foundation for studying the role of CTL in protection against malaria.

Dicroceliasis (lancet fluke disease) in an HIV seropositive man.

Dicroceliasis is an unusual zoonotic trematode infection caused by the lancet liver fluke, Dicrocoelium dendriticum. Grazing herbivores (usually sheep or cattle) are the definitive hosts. The life cycle proceeds through two intermediate hosts: the land snail and the field ant. Human infection is acquired by consuming the field ant. This case report describes a human immunodeficiency virus-seropositive patient who presumably acquired this parasite from bottled water contaminated with ants. A brief discussion of the parasitology, pathology, clinical findings and treatment is presented.

Tuberculosis presenting as puerperal fever.

Two cases of unusual postpartum fever in foreign nationals are presented. Prolonged work-up led to the diagnosis of pulmonary tuberculosis as a cause of postpartum fever that responded well to antituberculous drugs. The signs and symptoms illustrated by these cases should alert physicians to consider tuberculosis in their differential diagnosis when caring for pregnant immigrants. The changing patterns and diagnostic and therapeutic problems are discussed.

Plasmodium berghei: cloning of the circumsporozoite protein gene.

A DNA fragment encoding the carboxy terminal 80% of the Plasmodium berghei circumsporozoite protein was selected from a genomic DNA expression library. Sequencing revealed that the P. berghei circumsporozoite protein was similar in overall structure to circumsporozoite proteins from other malaria species, although the central repeat region was unique in comprising two different blocks of tandem peptide repeats: 11 eight amino acid repeats with predominant sequence DPAPPNAN were followed by 16 two amino repeats, predominantly PQ. The P. berghei circumsporozoite protein exhibited limited, but about equal amino acid homology to circumsporozoite proteins from P. knowlesi, P. vivax, and P. falciparum, indicating that P. berghei is not closely related to any of these other malaria species. Cloning of the P. berghei circumsporozoite protein gene will allow direct testing of sporozoite vaccines in mice.

Efficacy of murine malaria sporozoite vaccines: implications for human vaccine development.

As part of a study of potential vaccines against malaria, the protective efficacy of sporozoite subunit vaccines was determined by using the Plasmodium berghei murine malaria model. Mice were immunized with recombinant DNA-produced or synthetic peptide-carrier subunit vaccines derived from the repetitive epitopes of the Plasmodium berghei circumsporozoite gene, or with radiation-attenuated sporozoites. Immunization with subunit vaccines elicited humoral responses that were equivalent to or greater than those elicited by irradiated sporozoites, yet the protection against sporozoite challenge induced by either of the subunit vaccines was far less than that achieved by immunization with attenuated sporozoites. Passive and adoptive transfer studies demonstrated that subunit vaccines elicited predominantly antibody-mediated protection that was easily overcome whereas irradiated sporozoites induced potent cell-mediated immunity that protected against high challenge doses of sporozoites. These studies indicate that new strategies designed to induce cellular immunity will be required for efficacious sporozoite vaccines.

Urinary excretion of cyclic nucleotides, creatinine prostaglandin E2 and thromboxane B2 from mice exposed to whole-body irradiation from an enhanced neutron field.

Urine volume and excretion of cyclic AMP, cyclic GMP, prostaglandin E2 (PGE2), thromboxane B2 (TxB2) and creatinine were evaluated as potential indicators of radiation damage in mice given 2-5 Gy to the whole body from an enhanced neutron field. In general, urinary cyclic AMP, cyclic GMP, creatinine and urine volumes were positively correlated across time postexposure, for each radiation dose. TxB2 levels positively correlated with urine volume and cyclic AMP excretion only in animals given 2.0 Gy. None of these parameters suggests their use as a prognostic indicator of the extent of radiation damage. Urinary excretion of PGE2 was negatively correlated with other urinary parameters. Biphasic increases in urinary PGE2 were also observed. The initial transient elevation 2-3 days postexposure was not correlated with the dose (2-5 Gy). The second elevation of PGE2 excretion occurred at 6-10 days. The magnitude of the latter increase suggests that urinary PGE2 excretion may be a useful indicator of whole-body or kidney exposure to neutron fields.

Polyamine oxidase in human retroplacental serum inhibits the growth of Plasmodium falciparum.

Human retroplacental serum (RPS) containing polyamine oxidase inhibited the growth of the Camp strain of Plasmodium falciparum in vitro as assayed by the parasite's decreased incorporation of 3H-hypoxanthine. Inhibition was dose-dependent on the concentrations of serum polyamine oxidase and added polyamines. Almost complete inhibition was seen in 96-hr asynchronous cultures containing 10% RPS and in those containing 1.2% RPS plus 50 microM polyamine. Subtle morphologic changes in mature stages and decreased numbers of new rings were associated with inhibition seen in 19-hr synchronous cultures initiated at the trophozoite stage. These incubation times were longer than in previous reports showing inhibition of malaria parasites by bovine polyamine oxidase but not by human polyamine oxidase. Macrophages contain polyamine oxidase, the reaction products of which are known to be similar to those of RPS polyamine oxidase but different from those of bovine polyamine oxidase. It remains to be determined whether human polyamine oxidase, acting upon ubiquitous polyamines, contributes to host defenses against malaria.

Isolation of cold-sensitive mutants of measles virus from persistently infected murine neuroblastoma cells.

Clone NS20Y of the mouse neuroblastoma C1300 was infected with wild-type Edmonston measles virus, and, after a transition to a carrier culture, became persistently infected. Persistently infected clones were derived and characterized morphologically by the appearance of multinucleate giant cells and nucleocapsid matrices in cytoplasm and nucleus, but very few budding virus particles. Antimeasles antibodies markedly suppressed the expression of viral antigens and giant cells, and the effect was totally reversible. When the cells were cultured at 33 degrees C, the number of giant cells began to diminish and ultimately disappeared; in contrast, when cultured at 39 degrees C, the cultures invariably lysed. Yields at 33 degrees C were ca. 2 logs lower than those at 39 degrees C. Cells cultured at 33 degrees C produced relatively high levels of interferon, whereas those at 39 degrees C produced little or no interferon. When the persistently infected cultures were exposed to anti-interferon alpha/beta serum at a nonpermissive temperature, there was a marked increase in multinucleate cells, suggesting that maintenance of the persistence state and its regulation by temperature may be related to the production of interferon. Viral isolates from cells cultured at 39 degrees C were obtained, and 90% of viral clones were found to be cold sensitive. Complementation studies with different viral clones indicated that the cold-sensitive defect was probably associated with the same genetic function. Western blot analysis of the persistently infected cells indicated a significant diminution and expression of all measles-specific proteins at a nonpermissive temperature. Infection of NS20Y neuroblastoma cells with the cold-sensitive virus isolates resulted in the development of an immediate persistent infection, whereas infection of Vero or HeLa cells resulted in a characteristic lytic infection, suggesting that the cold-sensitive mutants may be selected or adapted for persistent infection in cells of neural origin.

Hageman factor activation and tight junction disruption in mice challenged with attenuated endotoxin.

Endotoxin treated with chromium chloride is less toxic to mice than the parent molecule, but can disrupt intestinal permeability barriers and has an enhanced ability to activate Hageman factor.

Possible association of granulocyte mobilization to the peritoneal cavity with ZnCl2-induced protection against endotoxin.

We have attempted to determine which components of the inflammatory response are responsible for ZnCl2-induced retention of endotoxin in the peritoneal cavity and enhancement of survival following challange with the toxin. ZnCl2 injected intraperitoneally into mice caused accumulation of granulocytes in the peritoneal cavity, but these cells were apparently not responsible for the trapping process. This contention in supported by our observation that reduction of hepatosplenic uptake of 51CR-labeled endotonxin was similar in unirradiated mice and in mice made by irradiation (1000 rad 60 Co) 1 rad = 10 (-2) J/kg). Hepatosplenic uptake was also depressed when untreated mice were injected with endotoxin suspended in cell-free plasma. Furthermore, zinc did not protect irradiated mice challanged with endotoxin, although it enhanced survival in urirradiated animals. Lack of protection in irradiated mice may be due to a deficiency in the cellular response in the peritoneal cavity.