RTS,S malaria vaccine efficacy and immunogenicity during Plasmodium falciparum challenge is associated with HLA genotype.

Although RTS,S remains the most advanced malaria vaccine, the factors influencing differences in vaccine immunogenicity or efficacy between individuals or populations are still poorly characterised. The analyses of genetic determinants of immunogenicity have previously been restricted by relatively small sample sizes from individual trials. Here we combine data from six Phase II RTS,S trials and evaluate the relationship between HLA allele groups and RTS,S-mediated protection in controlled human malaria infections (CHMI), using multivariate logistic or linear regression. We observed significant associations between three allele groups (HLA-A∗01, HLA-B∗08, and HLA-DRB1∗15/∗16) and protection, while another three allele groups (HLA-A∗03, HLA-B∗53, and HLA-DRB1∗07) were significantly associated with lack of protection. It is noteworthy that these 'protective' allele groups are thought to be at a lower prevalence in sub-Saharan African populations than in the UK or USA where these Phase II trials occurred. Taken together, the analyses presented here give an indication that HLA genotype may influence RTS,S-mediated protective efficacy against malaria infection.

Structural and functional cardiac adaptations to a 10-week school-based football intervention for 9-10-year-old children.

The present study investigated the cardiac effects of a 10-week football training intervention for school children aged 9-10 years using comprehensive transthoracic echocardiography as a part of a larger ongoing study. A total of 97 pupils from four school classes were cluster-randomized into a control group that maintained their usual activities (CON; two classes, n = 51, 21 boys and 30 girls) and a football training group that performed an additional 3 × 40 min of small-sided football training per week (FT; two classes, n = 46, 23 boys and 23 girls). No baseline differences were observed in age, body composition, or echocardiographic variables between FT and CON. After the 10-week intervention, left ventricular posterior wall diameter was increased in FT compared with CON [0.4 ± 0.7 vs -0.1 ± 0.6 (± SD) mm; P < 0.01] as was the interventricular septum thickness (0.2 ± 0.7 vs -0.2 ± 0.8 mm; P < 0.001). Global isovolumetric relaxation time increased more in FT than in CON (3.8 ± 10.4 vs -0.9 ± 6.6 ms, P < 0.05) while the change in ventricular systolic ejection fraction tended to be higher (1.4 ± 8.0 vs -1.1 ± 5.5%; P = 0.08). No changes were observed in resting heart rate or blood pressure. In conclusion, a short-term, school-based intervention comprising small-sided football sessions resulted in significant structural and functional cardiac adaptations in pre-adolescent children.

[Survival of patients with zidovudine resistant HIV]. / Patientoverlevelse ved zidovudinresistent HIV.

The survival of 35 patients with AIDS or advanced HIV infection on zidovudine treatment was related to the viral sensitivity to the drug and to the CD4+ cell count. Fourteen patients died, the survivors were followed up for an average of 804 days. In a univariate Cox model, survival was strongly related to log IC90 (p = 0.0003) and to the CD4+ count (p = 0.0002). In a bivariate model, log IC90 and the CD4+ count contributed to the prediction of survival (p = 0.12 and 0.06, respectively). Large studies of combination or alternation therapy with several anti-HIV-drugs should be given high priority.

[Pneumococcal bacteremia in Hvidovre Hospital 1986-1990]. / Pneumokokbakteriaemi på Hvidovre Hospital 1986-1990.

The study describes 156 consecutive cases of pneumococcal bacteraemia among patients admitted to Hvidovre Hospital during the five-year period 1986-1990. Pneumococcal bacteraemia was most common in the age groups 0-4 and 50-99 years. The most common focus of infection was the lungs (84%). 81% had preexisting diseases and the most common were: Immunosuppression due to drugs, alcoholism, cardiovascular disease, chronic obstructive lung disease, diabetes and myelomatosis. Patients over 65 years of age had a higher case fatality (35%) than younger (12%). The overall case fatality rate was 24%. Twenty-three percent of cases were hospital-acquired, and associated with a case fatality of 37%. Pneumococcal bacteraemia was most common during the winter season and unrelated to influenza. Eighty-four percent of the examined isolates represented capsular types included in the 23-valent pneumococcal vaccine. Three percent of the tested strains were relatively resistant to penicillin (MIC > 0.1 microgram/ml). Despite antibiotic treatment, the mortality from pneumococcal bacteraemia, particularly in elderly, remains high. With this in mind, one may consider offering pneumococcal vaccination to persons over 65 years of age with chronic predisposing diseases.

Synthesis and anti-HIV activity of 5-alkoxymethyl-3'-azido-2',3- dideoxyuridines.

Methyl 3-azido-5-O-tert-butyldiphenylsilyl-2,3-dideoxy-D-erythro-furanosi de (3) was coupled with silylated 5-hydroxymethyluracil (1a) and its C1-C6 alkyl ethers 1b-g to give the corresponding protected nucleosides 4a-g which were deprotected with Bu4NF to afford 3-azido nucleosides 5a-g and 6a-g. The alpha-anomers 6f,g show moderate activity against HIV. No significant activity against HSV-1 was found for the compounds 5 and 6.

Hepatitis C virus antibodies in homosexual men and intravenous drug users in Denmark.

In order to evaluate the role of sexual transmission and parenteral transmission of hepatitis C virus (HCV) in homosexual men and intravenous drug users (IVDU) serum samples from 147 homosexual men and 126 IVDU were tested for anti-HCV. Anti-HCV was found in two (1.4%) of the homosexual men and in 123 (98%) of IVDU. The presence of anti-HCV could not be correlated to the presence of HBV markers or HIV-antibodies. HCV is widespread among Danish IVDU. Risk of sexual transmission seems low even though sexual contact is a much more prevalent risk factor than needle sharing.

Development of resistance to zidovudine in HIV strains isolated from CD4+ lymphocytes and plasma during therapy.

An assay based on production of HIV antigen in cultures of CD4+ lymphocytes infected 'in vitro' with cell-free virus was established. Using this assay it was possible to isolate, propagate and reliably determine the zidovudine susceptibility of HIV isolates from all patients despite differences in cellular tropism and syncytium inducing capacity. Using this assay, differences in zidovudine susceptibility of 52 serial isolates obtained from 16 patients before and after initiation of therapy were examined. HIV with a 10- to 100-fold reduced susceptibility to zidovudine were isolated from 13 patients as early as 4 months after initiation of therapy. Number of months of zidovudine treatment was strongly associated with development of viral resistance, and high CD4 cell counts tended to be associated with lower rates of development of resistance. That patients can harbor mixtures of virus strains with different susceptibility to zidovudine was confirmed by the differences in susceptibility between isolates obtained simultaneously from CD4+ lymphocyte and plasma, and by the differences in susceptibility between virus strains isolated from clones of CD4+ lymphocytes.

Trend towards decreased survival in patients infected with HIV resistant to zidovudine.

The survival of 35 patients with AIDS or advanced HIV infection on treatment with zidovudine was related to the viral sensitivity to the drug and to the CD4+ cell count. 14 patients died, the survivors were followed up for an average of 804 days. In a univariate Cox model, survival was strongly related to log IC90 (p = 0.0003) and to the CD4+ count (p = 0.0002). In a bivariate model, log IC90 and the CD4+ count contributed to the prediction of survival (p = 0.12 and 0.06, respectively). Large studies of combination or alternation therapy with several anti-HIV drugs should be given high priority.

HIV-2 infection in Denmark.

A collection of 3019 selected serum samples (ss), comprising 329 ss from intravenous drug abusers, 558 ss from homosexual men, 682 samples from persons attending a STD clinic, 100 ss from individuals of African origin, 300 ss from sexual contacts to Africans, 650 ss from Danish blood donors who resided in Africa greater than 2 years prior to donating the ss, and 400 ss with equivocal antibody reactions in an HIV-1 Western blot was tested for antibodies against HIV-2 by in-house HIV-2 ELISA and Western blot. Four ss were positive for antibodies against HIV-2. Three of the ss originated from West African men, the fourth belonged to the spouse of one of these men. Three of the samples presented with an uncharacteristic reaction in a HIV-1 Western blot. The study indicates that HIV-2 infection is not yet widespread in Denmark and that it remains closely related to West Africa.

PIP: Clinicians drew blood samples from 3019 people living in Denmark to determine whether HIV-2 had reached that country. The groups tested included drug users from Copenhagen, healthy HIV-1 positive and negative homosexual men from Copenhagen, patients at a clinic for sexually transmitted diseases (STDs), healthy Africans, Danes who had sexual intercourse with an African, Danish blood donors who went to Africa more than 2 years before they gave a blood sample, and people who had inconclusive HIV-1 Western Blot (WB) patterns. Laboratory personnel used an in-house HIV-1 ELISA and an in-house HIV-2 ELISA to test all samples and an in-house HIV-2 test. 4 (.13%) samples tested positive for HIV-2. 3 of the serum samples were from men from the Ivory Coast, Guinea Bissau and Senegal. The 4th sample belonged to the wife of one of these men. She was positive only for HIV-2 while the 3 men also tested positive for HIV-1. The serum of 2 of the 3 people who tested ELISA HIV-1 reactive had inconclusive HIV-1 WB patterns who tested ELISA HIV-1 reactive had inconclusive HIV-1 WB patterns which made the researchers suspect HIV-2 infection. The woman's serum reacted to the core and env proteins in both the HIV-1 Wb and HIV-2 WB, the HIV-1 ELISA was negative. RIPA and immunofluorescence tests confirmed HIV-2 infection. Her case demonstrates the need to do both HIV-1 and HIV-2 ELISA tests. None of the 650 blood donors who had been in Africa within the last 10 years tested positive for HIV-2. These findings indicated that HIV-2 was not prevalent in Denmark and was limited to West Africa. Health workers whose patients have ties with West Africa and have an inconclusive HIV-1 WB pattern should request testing for HIV-2. The researchers suggested that serological surveillance for HIV-2 should be done at regular intervals.

Synthesis of 5-alkoxymethyl derivatives of 3'-amino-2',3'-dideoxyuridine and evaluation of their activity against HIV and cancer.

5-Alkoxymethyluracils 2a-c have been prepared by acid-catalyzed etherification of 5-hydroxymethyluracil (1). Compounds 1, 2a-c, 5-methoxymethyl- and 5-benzyloxymethyl-uracil were silylated and coupled with 1,5-di-O-acetyl-3-phthalimido-2,3-dideoxy-beta- D-erythro-pentofuranose (3), in the presence of trimethylsilyl triflate as a catalyst, to give the corresponding 3'-phthalimido-2',3'-dideoxynucleosides 5a-f and 6 which on treatment with 33% methylamine-ethanol afforded the corresponding 3'-amino-2',3'-dideoxynucleosides 7a-f and 8 in high yields. Compound 7d showed colony inhibition when tested against human epidermoid cervical cancer cells. Nucleosides 5a-e, 7a-f and 8 did not show any significant activity against HIV-1.

Neutralizing antibodies against two HIV-1 strains in consecutively collected serum samples: cross neutralization and association to HIV-1 related disease.

97 sera collected during a 10-year period from 10 HIV-1 infected individuals were tested for neutralizing capacity against a virus isolate FICPH-22 obtained from a Danish AIDS patient, and the laboratory strain HTLV-IIIB. Three patterns of serum neutralizing activity were demonstrated: (a) patients developing high neutralizing activity against both HIV strains; (b) patients developing high neutralizing activity against the Danish virus isolate; and (c) patients developing only low titers of neutralizing antibodies (NA) against both HIV strains. The HTLV-IIIB strain was less sensitive to serum neutralization than the FICPH-22 isolate and the appearance of NA against HTLV-IIIB was typically lacking several years behind that against FICPH-22 indicating a broadening of the NA response over time. No difference in clinical outcome was observed comparing patients reaching high titers of NA and patients with low titers. Development of AIDS among patients reaching high titers of NA was preceded by a decline in NA titers, indicating an association of high titers of NA with the healthy carrier state and of declining or low titers of NA with disease progression. The majority of the neutralizing activity was mediated by IgG, but some neutralizing activity was demonstrated in the IgG depleted serum, indicating the presence of additional neutralizing substances in serum.

Free-radical synthesis of 3-(2-cyanoethyl)- and 3-(2-methoxycarbonylethyl)-2,3-dideoxy-alpha-D-erythro-pentofu ranoside and their application in the synthesis of potential antiviral nucleosides.

Free-radical reaction of different carbohydrate educts 2, 5, and 7 with acrylonitrile in the presence of tributyltin hydride and a radical initiator (AIBN) gave the methyl 3-(2-cyanoethyl)-2,3-dideoxypentofuranosides 3a and 6. Similar reaction of 2 with methyl acrylate gave 3-(2-methoxycarbonylethyl)-2,3-dideoxypentofuranose 3b. Nucleoside coupling of 3a with silylated uracil gave an anomeric mixture of beta- and alpha-nucleoside 8 and 9 which were deprotected to give 10 and 11, respectively. Similar reaction of 3b with silylated N4-isobutyrylcytosine gave 12 and 13 which were deprotected to give the final nucleosides 16 and 17, respectively. None of the compounds 10a, 11, 14-17 showed significant activity against HIV.

Isolation of HIV from cultures of purified CD4+ lymphocytes.

Isolation of HIV from cultures of CD4+ lymphocytes purified from peripheral blood by indirect panning was optimized and evaluated. Infectious HIV was isolated by single isolation attempts in 98% of 102 HIV-antibody-positive patients (55 had AIDS or ARC and 47 were clinically healthy). The average culture time required for positive cultures was largely independent of the CD4 count of the patients and 87% of the positive isolation cultures from both groups of patients became positive within 14 days of culture. An evaluation of the possible influence of media additives on propagation of HIV showed that: amphotericin-B had a suppressive effect on HIV replication at concentrations recommended for anti-fungal activity; recombinant and human interleukin-2 were equally suitable for both isolation cultures and for propagation of HIV, and polybrene, at a concentration of 2 micrograms/ml in the culture medium had a beneficial effect.

New synthesis of 2',3'-didehydro-2',3'-dideoxynucleosides.

The 3'-iodonucleoside 4 and the 3'-O-methylsulfonylthymidine 9 have been synthesized by condensation of silylated uracils 2 with methyl 5-O-tert-butyldiphensilyl-2,3-dideoxy-3-iodo-D-threo-pentofuran oside (3) and methyl 5-O-tert-butyldiphenylsilyl-2-deoxy-3-methylsulfonyl-D-erythro- pentofuranoside (8), respectively. The nucleoside 4 and 9 produced the corresponding 2',3'-didehydro-2',3'-dideoxynucleosides 5 in an elimination reaction on treatment with sodium methoxide. The compounds 5b showed no antiviral activity against HIV-1.

Synthesis and evaluation of antiviral activity of L-acosamine and L-ristosamine nucleosides of furanose configuration.

Mercuric-catalyzed hydrolysis of acetylated L-rhamnal 1 gives an alpha,beta-unsaturated aldehyde 2. 1,4-Addition of DBU-phthalimide salt with concomitant acetyl shift resulted in L-ribo and L-arabino isomers of 5-O-acetyl-2,3,6-trideoxy-3-phthalimido-hexofuranose 3 and 4. After acetylation at the anomeric center, coupling with silylated thymine resulted in three new nucleosides, with L-acosamine and L-ristosamine of furanose configuration as the carbohydrate moiety. The target compounds have been evaluated for their antiviral activity against HIV and HSV-1.

HIV antigen-induced release of histamine from basophils from HIV infected patients. Mechanism and relation to disease progression and immunodeficiency.

Basophil leukocytes from 39 HIV-infected patients with various degrees of immunodeficiency and disease progression were stimulated with an HIV antigen preparation. Cells from 19 of 22 patients with AIDS and all of six patients with milder degrees of HIV-related disease showed significant histamine release. In contrast, cells from 11 asymptomatic HIV-infected patients and 11 healthy control persons released no histamine. The histamine release induced by HIV antigen was found to be inversely correlated to the number of CD4 positive T lymphocytes. These results indicate that the histamine release was related to both the clinical stage of disease and the degree of immunodeficiency. Passive sensitization experiments showed that IgE, but not IgG, was responsible for the induction of histamine release, indicating the reaction to be type 1 allergic. The histamine release caused by HIV might be involved in the development of disease because of the immunomodulating properties of this mediator.

Detection of human immunodeficiency virus DNA in cultured human glial cells by means of the polymerase chain reaction.

This report describes the use of the polymerase chain reaction (PCR) for the detection of viral genomic sequences in latently infected cells. Infection with human immunodeficiency virus in cultures of human glial cells was demonstrated, using nucleic acid amplification followed by dot blot hybridization. It was not possible to detect any viral antigen production in the cultures, and attempts to recover virus by highly sensitive coculture techniques were unsuccessful, indicating that the infection was latent. The PCR technique provides a simple approach to the study of viral infection in cases where viral replication is absent, or where genomic copies are present at such low numbers that they are otherwise undetectable.

Synthesis of 3'-amino-2',3'-dideoxy-hexofuranose nucleosides with potential anti-viral activity.

Michael type addition of DBU (1,8-diazabicyclo[5,4,0]undec-7-ene) phthalimide salt to 4,6-di-O-acetyl-2,3-dideoxy-aldehydo-D-erythro-trans-hex-2-enos e 2 and concomitant acetyl shift give an anomeric mixture of arabino and ribo isomers of 5,6-di-O-acetyl-2,3-dideoxy-3-phthalimido-D-hexofuranose 3 which after acetylation at the anomeric hydroxy group is separated to give 4 and 5. Subsequent reaction with 5'-substituted silylated uracil in the presence of TMS-triflate results in three different 5',6'-di-O-acetyl-2',3'-dideoxy-3'-phthalimido-D-hexofuranose nucleosides 7, 9, and 10 which were deprotected to give the corresponding 3'-amino nucleosides 8, 11, and 12. The compounds 7-12 were investigated for their activity against HSV-1 and HIV-1.

Prevalence of HIV infection in seronegative high-risk individuals examined by virus isolation and PCR.

HIV seronegative individuals with high-risk behavior were tested for HIV infection by sensitive virus isolation techniques using T4 lymphocytes and monocyte/macrophages, and by detection of proviral DNA using PCR with three different sets of nested primers. No evidence of HIV infection was found among the 31 seronegative high-risk subjects, either by virus isolation of by PCR (97.5% confidence limits, 0-11). Our results indicate that ongoing HIV infection in seronegative persons at high risk of infection is a rare event.

Synthesis of 3'-(4-nitroimidazol-1-yl)-2',3'-dideoxynucleosides of pyrimidine analogues and their biological evaluation against HIV.

Reaction of 1,5-di-O-acetyl-2,3-dideoxy-3-phthalimido-beta-D-erythro-pento-fur anose (1) with silylated pyrimidinediones 2a-c using the Lewis acid trimethylsilyl triflate as catalyst afforded nucleosides 3a-c and 4a,c which were deprotected with 33% methylamine/ethanol to give the corresponding 3-aminonucleosides 5a-c and 6. These were reacted with 1,4-dinitroimidazoles 7a,b to give the 3-imidazolyldideoxynucleosides 8a,b and 9a-f. At sub-toxic concentrations these compounds were ineffective against HIV-1.