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Biomedical subjects

D Taylor-Robinson

Publications and source records attributed to D Taylor-Robinson.

At least 181 records · Page 10Linked to original sources
PubMed1990

Neisseria gonorrhoeae colonises the genital tract of oestradiol-treated germ-free female mice.

Germ-free BALB/c mice treated with oestradiol and inoculated intravaginally with a serum-resistant strain or a freshly isolated, piliated strain of Neisseria gonorrhoeae were colonised vaginally. The organisms were recovered intermittently for a month or longer and there was evidence that they could reach the upper genital tract. Mice given progesterone and those not treated with either hormone did not become colonised. This is the first evidence of sustained mucosal colonisation in animals other than chimpanzees.

Animals↗
PubMed1990

The evolutionary watershed of susceptibility to gonococcal infection.

Gonococci do not cause genital infection in any convenient experimental animal, but all too easily cause genital infection in humans. To determine the 'evolutionary watershed' of gonococcal infections (the point on the evolutionary tree at which susceptibility to gonococcal infection begins) we extended previous studies of the interaction of gonococci with animal oviduct mucosa to include chimpanzees and baboons. Gonococci attached to, damaged, and invaded the oviduct (fallopian tube) mucosa of chimpanzees (which are apes) but not the oviduct mucosa of baboons (which are monkeys). Thus, the pattern of gonococcal infection in chimpanzees was identical to that in humans, whereas the pattern in baboons was like that in other animals. These studies indicate that the point in evolution at which susceptibility to gonococcal infection commences is between baboons and chimpanzees (or between monkeys and apes). Susceptibility to gonococcal disease appears to require the presence on genital epithelial cells of receptors for gonococcal ligands such as pili, receptors for gonococcal lipopolysaccharide, or both. The physiological role of these receptors may be to interact with more useful, as yet unidentified molecules.

Animals↗
PubMed1990

Elimination of mycoplasmas from the murine genital tract by hormone treatment.

Twenty progesterone-treated TO mice were infected intravaginally with Mycoplasma pulmonis. One month later, ten of the mice were given oestradiol which changed the reproductive cycle to the oestrous phase and within a week resulted in eradication of the organisms from six of them; vaginal persistence in the other mice may have been due, at least in part, to reinoculation of organisms from the oropharynx, a site heavily infected in all the mice. The majority of the mice not treated with oestradiol continued to shed the organisms from the vagina for at least 91 days. In another experiment, 19 oestradiol-treated BALB/c mice were infected intravaginally with M. hominis. One month later, nine of the mice were given progesterone which changed the reproductive cycle to the dioestrous phase and eradicated the organisms from seven within 2 weeks and from all of them within about a month. This was in contrast to the mice not given progesterone, the majority of which continued to shed the organisms for at least 167 days.

Animals↗
PubMed1990

Comparison of ofloxacin with doxycycline in the treatment of non-gonococcal urethritis and cervical chlamydial infection.

The efficacy of ofloxacin was compared with that of doxycycline in the treatment of non-gonococcal urethritis (NGU) and cervical chlamydial infection in an open randomized study. In total, 182 men and 100 women were enrolled: 92 men and 50 women received ofloxacin at a dose of 400 mg once daily for seven days, and 90 men and 50 women received doxycycline at a dose of 100 mg twice daily for seven days. All women and 42 men, that is 29 men in the ofloxacin group (32%) and 13 in the doxycycline group (14%) were chlamydia-positive on entry into the study. Patients were reviewed on completion of the treatment course (day 8) and two weeks later (day 22). Clinical cure rates for NGU in assessable patients in each treatment group were similar; 73% in the ofloxacin group and 63% in the doxycycline group at day 8, and 70% and 90% in the respective treatment groups on study completion. Repeat tests for chlamydiae were negative for all male and female patients at both day 8 and day 22. Both ofloxacin and doxycycline were well tolerated. We conclude that ofloxacin given at a dose of 400 mg once daily for seven days is a safe and effective alternative treatment for NGU and cervical chlamydial infection.

Adolescent↗
PubMed1990

Long-term viability of stored mycoplasmas and ureaplasmas.

All of five lyophilised cultures of Mycoplasma orale kept for 23 years at room temperature were still viable, as were all but one of 12 lyophilised cultures of six Mycoplasma spp. that had been stored for 18-22 years at 4 degrees C. Similarly, 11 of 13 lyophilised ureaplasma cultures were viable after 8-22 years at 4 degrees C; the titre of organisms in the viable cultures had diminished no more than 100-fold. Seven broth cultures of five different Mycoplasma spp. all proved viable 5-13 years after being frozen and stored at -70 degrees C, although there was up to 10(4)-fold reduction in the titre of organisms in some cultures. Furthermore, 18 (82%) of 22 different Mycoplasma spp., originally lyophilised and then reconstituted and stored at -70 degrees C, were viable after 16 years. Viable organisms were found, with little or no reduction in titre, in all of seven broth cultures of Ureaplasma urealyticum, comprising six serotypes, after storage for 6-10 years at -70 degrees C, but five of 18 broth cultures of other human and animal ureaplasmas stored likewise were not viable after 13-14 years and in a further seven of them the titre of viable organisms had diminished greater than or equal to 10(4)-fold.

Animals↗
PubMed1990

A comparison of four major antigens in five human and several animal strains of ureaplasmas.

A comparison of the antigens of single representatives of five serotypes of Ureaplasma urealyticum, of three strains of U. diversum and of single ureaplasmal strains from four other animal hosts was performed by immunoblotting with monoclonal antibodies and a urease 'enzyme-catch test'. The U. urealyticum serotype 8-specific, surface-expressed, 96-Kda antigen was not found in any of the strains of non-human origin. Differences in the distribution of 16- and 17-Kda antigens were also seen, not only between seroclusters A and B of U. urealyticum, but also with respect to animal strains. Five distinct epitopes were expressed on the urease from U. urealyticum and from chimpanzee ureaplasmal strains, but between one and three of these epitopes were either poorly expressed or not detected on the urease from the other animal strains. Apart from lacking the 96-Kda antigen of U. urealyticum serotype 8, chimpanzee strains gave results similar to those obtained with serocluster A of U. urealyticum. The results with the marmoset strain differed from those of all other non-human strains.

Animals↗
PubMed1990

A prospective study of human papillomavirus infection of the cervix.

In a prospective study 42 women, diagnosed as having low grade cervical intraepithelial neoplasia (CIN), made a total of 281 clinic visits over a 45 month period. At each visit, they were subjected to cytological and colposcopical examination and samples were taken for human papillomavirus (HPV) DNA hybridization studies and for the detection of non-HPV infections. HPV types 16 and/or 18 were found in 25% of all the samples tested and these virus types were detected in five of six (83%) women whose lesions progressed compared to seven of 14 (50%) of those whose lesions regressed. The presence of HPV DNA was not a good prognostic indicator of progression since half of those whose disease regressed also harboured these viruses at some time. The recording of non-HPV infections almost 10 times more often in the women whose disease regressed than in those whose disease progressed could probably be accounted for by the former having a larger number of follow-up visits. Nevertheless, the significance of non-HPV infections also remains unclear.

Bacterial Infections↗
PubMed1990

Comparison of quantitative and qualitative methods of detecting hydrogen peroxide produced by human vaginal strains of lactobacilli.

A quantitative method was developed for the measurement of micromolar quantities of H2O2 produced in Rogosa broth and peptonized milk broth by vaginal strains of lactobacilli isolated from women. The production of substantial amounts reproducibly was dependent on the growth of the organisms in acid media (pH less than or equal to 6.0) under anaerobic or micro-aerophilic conditions with continuous agitation. The addition to the media of the enzyme inhibitor, 3-amino-1,2,4-triazole, with or without catalase sometimes induced the production of H2O2 especially in non-agitated cultures. However, other agents such as concanavalin and o-dianisidine had no enhancing effect, and catalase or peroxidase alone completely inhibited H2O2 production. The H2O2 produced in the acid media was stable for more than a month at 5 degrees C but not in media at pH greater than or equal to 7.0. Of five strains of lactobacilli tested by the quantitative method and by a chromogenic qualitative method (Rogosa-catalase or -per-oxidase agar), three consistently produced H2O2 measurable by the former method, but none did so after growth of the organisms on Rogosa-catalase/peroxidase agar which suggested that the qualitative method was unreliable. The fact that H2O2 was produced in substantial quantities by some strains and not at all by others enabled H2O2-producers and non-producers to be distinguished easily.

Culture Media↗
PubMed1990

Intraprostatic antibody deposition in chronic abacterial prostatitis.

Sixty patients with chronic abacterial prostatitis and 21 men without prostatitis were studied. Transperineal prostatic biopsies taken under transrectal ultrasound control were examined for antibody, complement (C3) and fibrinogen deposition using a direct immunofluorescence (IF) technique; 34 patients (57%) had prostatic tissue that displayed IF staining compared with only 1 (5%) in the non-prostatitis group. IF staining for IgM was found in 85%, for C3 in 44%, for IgA in 35% and for fibrinogen in 24%, but the IgG subclass was not detected. Antibody deposition was mainly periglandular and glandular and in the wall of vessels. Five symptoms, particularly poor urinary flow, irritative voiding and urgency, were significantly correlated with IgM and C3 deposition and, to a lesser extent, fibrinogen deposition. The aetiology of chronic abacterial prostatitis remains obscure but several possible mechanisms are discussed. The link between symptomatology and immunology could rest with functional outflow obstruction causing intraprostatic reflux of urine, this in turn inciting an immunological response, the inducing antigens being organism remnants or products, urinary constituents or autoantibodies.

Adult↗
PubMed1990

Scrotal ulceration in HIV-positive patients.

Four patients with scrotal ulceration were seen during a period of 9 months. All of them were HIV-positive homosexual men with coexisting skin conditions. Herpes simplex virus was not isolated from any of the ulcers, but a variety of bacteria was recovered. It is suggested that multiple factors peculiar to HIV-positive individuals may account for the development of such ulcers.

Adult↗
PubMed1990

Detection of treponemal DNA in the CSF of patients with syphilis and HIV infection using the polymerase chain reaction.

The polymerase chain reaction (PCR) was used to detect Treponema pallidum DNA in the cerebrospinal fluid (CSF) of patients with and without syphilis. The CSF from 10 of 19 patients with positive serological tests for syphilis who were being investigated for late syphilis were treponemal DNA-positive. In contrast, the CSF from only one of 30 patients with no known history of syphilis was DNA-positive. CSF from 28 HIV-positive patients was also tested. Fourteen of these patients had central nervous system (CNS) disease and seven were DNA-positive, whereas none of the 14 without CNS disease were DNA-positive. Five of the seven DNA-positive patients had a history of syphilis. Such a history in an HIV-positive patient who had CNS disease was predictive of finding treponemal DNA in the CSF. The PCR had a sensitivity of 47% and a specificity of 93% for detecting a known history of syphilis and is a potentially useful tool in treponemal diagnosis.

Acquired Immunodeficiency Syndrome↗
PubMed1990

A 2-year quantitative assessment of Chlamydia trachomatis in a sexually transmitted diseases clinic population by the MicroTrak direct smear immunofluorescence test.

The MicroTrak direct smear immunofluorescence test was used to determine the prevalence of Chlamydia trachomatis elementary bodies (EBs) in groups of patients in various clinical categories, most of whom were seen in a clinic for sexually transmitted diseases (STD). Overall, 8138 adequate specimens were tested, of which 14.3% were found to contain chlamydial EBs. Of the samples from patients seen in the STD clinic, over 70% were from women and 14.9% of these were positive, as were 15.7% of those from men. EBs were detected in 27% of samples from infants and in 7.0% of those from adults with conjunctivitis. EBs were detected most often in men with nongonococcal urethritis (40.2%), infants with conjunctivitis (30%) and contacts of chlamydiae-positive patients (24.5%) and least often in 'prostatitis' (2.9%) and patients tested to determine the success of treatment (2.7%). Over 40% of samples from both the male urethra and the cervix contained 10 or fewer EBs, highlighting the importance of recognizing small numbers and the sensitivity required of other detection procedures.

Adult↗
PubMed1990

Inhibition of urethane leukaemia virus, a murine retrovirus, in mice by zidovudine.

The purpose of the study was to characterize in vivo an immunodepressive murine retroviral 'model' for the possible testing of drugs against HIV infection. Urethane leukaemia virus (ULV) injected into adult BALB/c mice (10(5) focus-forming units/mouse) caused a small, significant splenomegaly from 2 to at least 9 weeks after virus inoculation. Virus was also present in up to 60% nucleated splenocytes (XC 'infectious centre assay'). Effects on splenomegaly and virus in splenocytes were assayed following various regimens of zidovudine given as 0.5 mg/ml or 0.25 mg/ml in drinking water. Regimens included continuous treatment both before and after ULV, only before, and only after ULV inoculation. Zidovudine was also given for a limited period immediately after virus, or initiated after virus infection was established. Zidovudine given continuously at and following ULV infection completely prevented splenomegaly and virus expression in splenocytes. No other regimen was as effective; however, limited zidovudine treatment immediately after virus inoculation greatly reduced the effects of virus, while the same dose initiated after virus infection was established had only a small ameliorating effect. We conclude that ULV may prove to be a useful addition to other available murine systems, and this is discussed.

Analysis of Variance↗
PubMed1990

Medical and social aspects of sexual assault of males: a survey of 100 victims.

Sexual assault of males is an infrequently reported and a poorly understood phenomenon. Details of 100 victims who sought assistance from a nationwide agency set up specifically to provide help for such individuals are reported here. Twenty eight victims were aged 16 years or over at the time of assault. The assailants were known by 72 of the victims and were perceived by the victim to have a heterosexual orientation in 72% of these cases. Attacks were often multiple and in 33 cases involved disruption of skin or mucous membranes. Twenty victims received threats about the possibility of transmission of the human immunodeficiency virus and 17 victims sought medical advice following the assault, most commonly from their general practitioner. It is suggested that greater opportunities for medical and psychological support should be given to male victims of sexual assault.

Adolescent↗
PubMed1990

Characterization of skin lesions in mice following intradermal inoculation of Haemophilus ducreyi.

Twelve strains of H. ducreyi, which included two reference strains, were each inoculated intradermally into the flanks of CBA mice. All strains produced self-limited lesions which were macroscopically and microscopically typical of those seen in chancroid. Pustular nodules, about 5mm in diameter, developed at all inoculation sites by the second day when 10(7) organisms were inoculated. Approximately half of these lesions ulcerated and all had regressed by 2 weeks. Smaller nodules developed at about half the sites from the second to the fifth day when 10(6) or 10(5) organisms were given, but these did not ulcerate. No lesions were seen when 10(3) organisms were inoculated. Organisms were recovered from the lesions up to 11 days after inoculation. Specific H. ducreyi antigen, sought by a monoclonal antibody test, was detected in lesions up to 15 days following inoculation. Heat-killed organisms of H. ducreyi also produced nodules and ulcers although these were slightly smaller than those which developed after inoculation of viable bacteria. Similar lesions to those caused by H. ducreyi were produced after intradermal inoculation of about 10(8) viable or killed Neisseria gonorrhoeae organisms. Treatment of mice with ceftriaxone had little or no effect on the subsequent development of H. ducreyi-induced lesions. These findings indicated that the lesions were not produced specifically by viable H. ducreyi organisms. Ulcers were also produced following intradermal inoculation of purified lipopolysaccharide (LPS) from H. ducreyi or N. gonorrhoeae, but not by cell-free filtrates prepared from H. ducreyi cultures indicating a possible role for LPS in the pathogenesis of ulcerative skin lesions.

Animals↗
PubMed1990

Severity of salpingitis in mice after primary and repeated inoculation with a human strain of Chlamydia trachomatis.

Groups of inbred female mice of strains CBA or C3H were infected genitally with a pathogenic human strain of Chlamydia trachomatis (N.I.1, serovar F) known to produce salpingitis and infertility in mice. Mice were inoculated under the ovarian bursa or directly into the uterine cavity with chlamydiae (test groups) or with sucrose-phosphate transport medium (control groups) before being challenged with chlamydiae by the same route 12-17 weeks later. Twenty-five pairs of test and control animals were killed from 7 to 77 days after challenge and oviductal inflammatory changes, recovery of organisms, and antibody responses were compared in the two groups. Salpingitis in the mice infected previously (tests groups) was more severe than in the controls in 56% of comparisons, the same in 24% and less severe in 20%. However, despite the increase in the severity of disease, shedding of C. trachomatis from the lower genital tract was less prolonged after rechallenge or did not occur. Salpingitis occurred in spite of the almost certain presence of pre-existing serum antibody, and accelerated and accentuated antibody response in the rechallenged mice. Furthermore, the continued existence of high titres of antibody was not associated with less severe disease. Thus, the results reveal that previous exposure to chlamydiae does not prevent salpingitis and suggest that its severity is influenced by cell-mediated immune mechanisms.

Animals↗