The gene mutated in bare patches and striated mice encodes a novel 3beta-hydroxysteroid dehydrogenase.

X-linked dominant disorders that are exclusively lethal prenatally in hemizygous males have been described in human and mouse. None of the genes responsible has been isolated in either species. The bare patches (Bpa) and striated (Str) mouse mutations were originally identified in female offspring of X-irradiated males. Subsequently, additional independent alleles were described. We have previously mapped these X-linked dominant, male-lethal mutations to an overlapping region of 600 kb that is homologous to human Xq28 (ref. 4) and identified several candidate genes in this interval. Here we report mutations in one of these genes, Nsdhl, encoding an NAD(P)H steroid dehydrogenase-like protein, in two independent Bpa and three independent Str alleles. Quantitative analysis of sterols from tissues of affected Bpa mice support a role for Nsdhl in cholesterol biosynthesis. Our results demonstrate that Bpa and Str are allelic mutations and identify the first mammalian locus associated with an X-linked dominant, male-lethal phenotype. They also expand the spectrum of phenotypes associated with abnormalities of cholesterol metabolism.

Human papillomavirus DNA in the urogenital tracts of men with genital dermatoses: evidence for multifocal infection.

In an attempt to assess the multifocal nature of anogenital HPV infection in men, skin biopsies, urethral swabs and urine specimens were obtained from 100 men with genital dermatoses. The specimens were examined for the presence of human papillomavirus (HPV) types 6, 11, 16, 18, 31 and 33 using the polymerase chain reaction and Southern blotting techniques. HPV DNA was detected in one or more specimens from 39 patients, that is 29 of 100 biopsy specimens, 21 (25%) of 85 urethral swab specimens and 6 (10%) of 59 urine specimens. HPV DNA was more common in men with at least 20 lifetime sexual partners and in those who gave a history of anogenital warts. Twelve (18%) of 66 biopsy specimens with no histological evidence of warty change or neoplasia had detectable HPV DNA. HPV DNA was detected no more frequently in the urethral and urine specimens from men with histological evidence of warts or neoplasia than from men without such changes. HPV types 6 and 11 were most common in biopsy specimens with histological changes of typical HPV infection. HPV type 16 was commonest in biopsy specimens with neoplasia and type 18 with other changes. Furthermore, 'high-risk' HPV types were found proportionately more often in urethral swab and urine specimens than in biopsy specimens. There was generally a poor correlation between the detection of HPV DNA at the different sites. A greater understanding of the role of HPV in the production of genital abnormalities is required in order to develop a rational approach to the management of these patients.

Changes in HPV infection in patients with anogenital warts and their partners.

OBJECTIVES--To investigate the relationship between clinical findings and the detection of human papillomavirus (HPV) DNA in a range of anatomical sites in patients with and without anogenital warts. SUBJECTS--Men and women with a clinical diagnosis of anogenital warts, or a current partner with anogenital warts. SETTING--A department of genitourinary medicine in central London. METHODS--The anogenital areas of the patients were thoroughly examined using a colposcope before and after application of acetic acid. Different types of specimens were taken from a variety of anatomical sites. Superficial skin sampling was performed by the application of slides covered with "Superglue" (SG) to clinically normal and abnormal areas of anogenital skin. The presence of human cells in the SG samples was confirmed by detection of the beta-globin gene using the polymerase chain reaction (PCR). HPV DNA was extracted from the specimens and amplified by using consensus primers with the PCR. HPV types 6, 11, 16, 18, 31 and 33 were identified by Southern blotting followed by hybridisation. RESULTS--In women, HPV DNA was detected in 83% of wart biopsies, 29% of cervical biopsies, 36% of cervical scrapes, 25% of urethral loop specimens, 37% of vaginal washes and 33% of rectal swab specimens. In men, HPV DNA was detected in 67% of wart biopsies, 37% of urethral loop specimens and 12% of rectal swab specimens. Of the SG samples containing the beta-globin gene, 49% from women and 50% from men contained HPV DNA. HPV DNA was not detected in buccal scrapes and serum samples from women or men. Of all specimens with detectable HPV DNA, there was evidence of a single HPV type in 41%, multiple types in 48% and undetermined types in 11%. Samples taken from different sites of a patient tended to have HPV types in common. Sexual partners, however, did not consistently have HPV types in common. CONCLUSIONS--HPV DNA was distributed widely in the anogenital area, in warts, acetowhite areas and clinically normal skin. The SG technique was well tolerated by patients and produced results consistent with other findings. Sampling from a single site of the genitalia on one occasion may significantly underestimate the infection rate with HPV. Multifocal infection of the anogenital area with HPV should be taken into consideration when interpreting epidemiological studies and management strategies.

Detection of human papillomavirus DNA in the urogenital tracts of men with anogenital warts.

Increasing evidence suggests that human papillomavirus (HPV) infection of the female anogenital tract is multifocal. Less is known of the distribution of HPVs in men. To investigate this, a prospective study was conducted of 116 men consecutively attending a clinic for ablative treatment of anogenital warts. Wart tissue, urethral swabs, and urine were obtained from each patient. HPV DNA was extracted from the specimens and amplified using the polymerase chain reaction (PCR). HPV types 6, 11, 16, 18, 31, and 33 were identified using Southern blotting of the PCR product, followed by hybridization. HPV DNA was detected in 112 (96.6%) of 116 wart specimens and there was urethral infection with HPV in 26 (22.4%) of the men. Eleven (61.1%) of 18 urethral specimens taken with a loop and 22 (20.0%) of 116 urethral specimens taken using a cotton-tipped swab contained HPV DNA. One (6.3%) of 16 urine samples tested contained HPV DNA. HPV types 6 and 11 were found in the urethra most commonly when warts were seen near the urinary meatus, although HPV occurred in the urethras of men without clinically apparent meatal warts. The proportion of urethral samples with HPV DNA, including HPV types 16, 18, 31, and 33, was independent of the location of visible warts at the time of sampling.

Human papillomavirus DNA in the urogenital tracts of men with gonorrhoea, penile warts or genital dermatoses.

OBJECTIVE: To assess the presence of human papillomavirus (HPV) DNA in urethral and urine specimens from men with and without sexually transmitted diseases. DESIGN: Prospective study. SETTING: Two London departments of genitourinary medicine PATIENTS: 100 men with urethral gonorrhoea, 31 men with penile warts and 37 men with genital dermatoses. METHODS: Urethral and urine specimens were taken, HPV DNA extracted and then amplified using the polymerase chain reaction. HPV types 6, 11, 16, 18, 31 and 33 were identified using Southern blotting followed by hybridisation. RESULTS: HPV DNA was detected in 18-31% of urethral swab specimens and in 0-14% of urine specimens. Men with penile warts had HPV detected in urethral swabs more often than did men in the other two clinical groups. "High risk" HPV types were found in 71-83% of swab specimens and in 73-80% of urine specimens containing HPV DNA. CONCLUSIONS: HPV is present in the urogenital tracts of men with gonorrhoea, penile warts and with genital dermatoses. In men with urethral gonorrhoea, detection of HPV in urethral specimens is not related to the number of sexual partners, condom usage, racial origin or past history of genital warts. HPV DNA in the urethral swab and urine specimens may represent different aspects of the epidemiology of HPV in the male genital tract. The preponderance of HPV types 16 and 18 in all three groups of men may be relevant to the concept of the "high risk male".

Effects of murine leukemia viruses on the function of dendritic cells.

In asymptomatic human immunodeficiency virus-1 infection T cells respond normally to allogeneic dendritic cells (DC), but DC show reduced stimulatory capacity. By contrast in HTLV-1 infection no significant changes in allogeneic stimulation were seen but DC-stimulated activity of autologous T cells. In seeking animal models relevant to these diseases the effects of two murine leukemia retroviruses, Rauscher leukemia virus (RLV) and Moloney leukemia virus (MLV) on the function of dendritic cells and T cells in a primary mixed leucocyte reaction have been tested. Treatment by RLV in vitro suppressed the ability of DC to stimulate allogeneic T cells from healthy animals. MLV at the same concentration did not significantly affect the ability of DC to stimulate allogeneic T cells, but provoked considerable enhancement of the low level stimulation by DC in the syngeneic system. Similar results were obtained following in vivo exposure to viruses. Two pieces of evidence suggested that these effects were due to impairment of DC function and were not operating through infection of T cells. Firstly, exposure of T cells directly to virus in vitro and in vivo before stimulation with untreated allogeneic DC caused no significant alteration in T cell activity. Secondly, the impact of murine leukemia virus on DC function was not abrogated when infected DC were added to normal T cells and cultured in the presence of zidovudine. Treatment of DC by RLV caused a decrease of cluster formation with allogeneic T cells. No statistically significant influence of MLV was observed on cluster formation after 3-h of incubation in the allogeneic system. However, after 18-h incubation MLV-treated DC formed fewer clusters with T cells than untreated DC. At the same time a stimulatory effect of MLV on DC cluster formation with syngeneic T cells was found. Considerable decrease was found in major histocompatibility complex class II antigen and LFA-1 receptor expression on the DC surface in mice infected by RLV. MLV induced no significant changes. These mouse retroviruses can therefore cause changes in DC function similar to those already reported using human retroviruses and may provide models for studying their effects.

Is HIV infection associated with an increase in the prevalence of cervical neoplasia?

OBJECTIVE: To test the hypotheses: (1) that HIV infection predisposes to cervical intraepithelial neoplasia (CIN); (2) that this CIN is a result of HIV related immunosuppression; and (3) that this CIN is a result of immunosuppression causing increased expression of the potentially oncogenic viruses, human papilloma virus (HPV), Epstein Barr virus (EBV) and herpes simplex virus (HSV). DESIGN: A matched cross sectional study. SETTING: The Department of Gynaecological Oncology, The Samaritan Hospital, London; the Department of Genitourinary Medicine, St Mary's Hospital, London; and the Family Planning Clinic, Claremont Terrace, Glasgow. SUBJECTS: Fifty HIV seropositive women enrolled from the Genitourinary Medicine Department and the Drug Dependency Unit at St Mary's Hospital, London, and the Unit of Infectious Diseases at Ruchill Hospital, Glasgow. Forty-three HIV seronegative controls enrolled from the Department of Genitourinary Medicine at St Mary's Hospital, matched against 43 of the seropositive women for age, age at first intercourse, lifetime number of sexual partners, and smoking habit. MAIN OUTCOME MEASURES: Associations between CIN, as detected by cytology and histology, and HIV infection. Association was also sought between CIN and immunosuppression, as measured clinically by T4 cell number, beta-2-microglobulin and p24 antigen. Associations of these with: (1) HPV, as detected by Southern blot testing and the polymerase chain reaction; (2) EBV, as detected by Southern blot testing; and (3) HSV, as detected by tissue culture of endocervical swabs, was also studied. RESULTS: There was no significant difference in the prevalence of CIN or oncogenic viruses between HIV seropositive and seronegative women in the absence of immunosuppression. If the HIV infected women showed signs of immunosuppression, the prevalence of CIN was increased. No association was shown between detection of HPV, EBV and HSV and immunosuppression or CIN. CONCLUSION: HIV infection may only be associated with an increased risk of CIN when immunosuppression is present.

Modulation of mRNA levels in the presence of thymocytes and genome mapping for a set of genes expressed in mouse thymic epithelial cells.

Modulation of gene expression in mouse thymic epithelium upon culture in the presence of thymocytes (coculture) was studied by comparison of hybridization signatures on a set of nearly 5000 mouse thymus cDNA clones. Forty-nine differentially expressed clones (usually down-regulated in coculture) were characterized by tag sequencing. Many of them corresponded to entities that had not been described previously in the mouse, and were further characterized by genome mapping. This set of genes appears to be involved in growth regulation and differentiation within the thymus.

Comparative genome sequence analysis of the Bpa/Str region in mouse and Man.

The progress of human and mouse genome sequencing programs presages the possibility of systematic cross-species comparison of the two genomes as a powerful tool for gene and regulatory element identification. As the opportunities to perform comparative sequence analysis emerge, it is important to develop parameters for such analyses and to examine the outcomes of cross-species comparison. Our analysis used gene prediction and a database search of 430 kb of genomic sequence covering the Bpa/Str region of the mouse X chromosome, and 745 kb of genomic sequence from the homologous human X chromosome region. We identified 11 genes in mouse and 13 genes and two pseudogenes in human. In addition, we compared the mouse and human sequences using pairwise alignment and searches for evolutionary conserved regions (ECRs) exceeding a defined threshold of sequence identity. This approach aided the identification of at least four further putative conserved genes in the region. Comparative sequencing revealed that this region is a mosaic in evolutionary terms, with considerably more rearrangement between the two species than realized previously from comparative mapping studies. Surprisingly, this region showed an extremely high LINE and low SINE content, low G+C content, and yet a relatively high gene density, in contrast to the low gene density usually associated with such regions.