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Biomedical subjects

P Horner

Publications and source records attributed to P Horner.

At least 19 recordsLinked to original sources
PubMed2006

The potential role of serology in diagnosing chronic lymphogranuloma venereum (LGV): a case of LGV mimicking Crohn's disease.

We present the case of a 26 year old HIV positive homosexual man who was managed for suspected Crohn's disease for over 1 year before lymphogranuloma venereum (LGV) was clinically diagnosed. He had presented with constipation, secondary to acute haemorrhagic proctitis, and subsequently had two chlamydia negative rectal smears, using direct fluorescent antibody (DFA) Chlamydia trachomatis staining. Positive chlamydial serology guided retrospective testing of an early rectal biopsy, which was found to have C trachomatis by polymerase chain reaction (Roche Cobas) and identified as LGV serovar L2 by the Sexually Transmitted Bacteria Reference Laboratory (STBRL), Health Protection Agency (HPA), Colindale, London. Chlamydial serology may have a role in identifying late stage LGV infection. Although no standardised test currently exists, consideration should be given to evaluating the role of chlamydial serology in establishing a diagnosis of LGV.

Adult↗
PubMed2006

Testing specimens for Chlamydia trachomatis.

The introduction of NAATs has revolutionised chlamydial diagnostics and these tests are now the standard of care. However, as with all new technologies, they have also presented new challenges. This review attempts to answer some of the questions that have been raised, particularly by groups about to embark on implementing a screening programme. Laboratory tests are continually changing but it is hoped that the paper provides a useful update of the current situation.

Chlamydia Infections↗
PubMed2006

The case for further treatment studies of uncomplicated genital Chlamydia trachomatis infection.

Azithromycin 1 g immediately and doxycycline 100 mg twice daily have good antimicrobial activity against Chlamydia trachomatis and treatment studies have demonstrated a >95% microbiological cure at 2-5 weeks, with antimicrobial resistance being rarely reported. Recently an 8% (95%, CI 5% to 11%) failure rate was observed in 289 women, but not in men, who had been sexually inactive after treatment. At high multiplicities of infection (load) in vitro persistence can often be demonstrated to antimicrobials-heterotypic resistance. The subsequently recovered isolates do not possess antimicrobial resistance at low loads. It is known that genital chlamydia load varies in vivo and is probably greater in women than men. In mass treatment trials of trachoma, treatment failure is associated with high chlamydia loads. It is therefore possible that women with high chlamydia loads may be at increased risk of treatment failure. Given the imminent role out of the National Chlamydia Screening Programme and the consequences of persistent chlamydial infection in women this hypothesis urgently merits further investigation.

Anti-Bacterial Agents↗
PubMed2001

Role of Mycoplasma genitalium and Ureaplasma urealyticum in acute and chronic nongonococcal urethritis.

One hundred fourteen heterosexual men with acute nongonococcal urethritis (NGU) and 64 patients without NGU were studied. We determined that Chlamydia trachomatis and Mycoplasma genitalium were strongly associated with acute NGU after controlling, by means of multivariate analysis, for age, race, sexual lifestyle, and coinfection (odds ratio [OR], 13.0, 95% confidence interval [CI], 2.6-64.5; and OR, 17.9, 95% CI, 2.0-160, respectively). Eighty-six men with acute NGU reattended at least once 10-92 days after treatment; 59 (69%) of these 86 men had urethritis. Seven men had M. genitalium detected during 10-92 days of follow-up, and all had urethritis. Ureaplasmas were not associated with acute NGU in multivariate analysis, but their detection was associated with the presence of urethritis during follow-up (P=.014). Ureaplasmas or M. genitalium were associated with both chronic NGU, which was defined as urethritis that occurred 30-92 days after the commencement of treatment (P=.028), and chronic NGU with symptoms or signs (P=.005).

Acute Disease↗
PubMed2001

Light-induced autofluorescence spectroscopy for the endoscopic detection of esophageal cancer.

BACKGROUND: Any innovative optical system that facilitates the early endoscopic detection of neoplastic change in the GI mucosa has the potential to greatly improve survival and quality of life for patients prone to have GI malignancies develop. The present article describes light-induced autofluorescence spectroscopy with violet-blue excitation light for in vivo diagnosis of cancerous tissue of the esophagus during routine endoscopy. METHODS: One hundred twenty-nine endogenous fluorescence spectra were obtained from normal mucosa and malignant lesions in 9 patients with squamous cell cancer and 4 with adenocarcinoma of the esophagus. Following spectrographic measurements, biopsy specimens were obtained for definitive classification of the spectra. A special light source capable of delivering either white or violet-blue light for excitation of tissue autofluorescence by means of an endoscope was used. Endogenous fluorescence spectra emitted by tissues were detected with a fiberoptic probe and analyzed with a spectrograph. RESULTS: Squamous cell cancer and adenocarcinoma of the esophagus exhibit specific changes in the emitted fluorescence spectra as compared with normal mucosa. Based on the results obtained in earlier studies, malignant and benign spectra were differentiated with the aid of a mathematical algorithm. By using this algorithm, a sensitivity of 97% and specificity of 95% were obtained for the diagnosis of esophageal carcinoma. CONCLUSIONS: Light-induced fluorescence spectroscopy is useful for the endoscopic detection of squamous cell cancer and adenocarcinoma of the esophagus. This spectroscopic study provides a basis for the design of a simplified autofluorescence imaging system for detection of esophageal neoplasms.

Adenocarcinoma↗
PubMed2001

Antibiotic prophylaxis to prevent post-abortal upper genital tract infection in women with bacterial vaginosis: randomised controlled trial.

OBJECTIVE: To determine the prevalence of bacterial vaginosis in women undergoing first trimester suction termination of pregnancy and to evaluate the efficacy of metronidazole in reducing the risk of post abortal pelvic infection in women with bacterial vaginosis. DESIGN: Randomised double-blind placebo-controlled trial. SETTING: Two teaching hospitals and one district general hospital. SAMPLE: Two hundred and seventy-three women with bacterial vaginosis undergoing termination of pregnancy. METHODS: Women with bacterial vaginosis, diagnosed using modified Spiegel's criteria, were individually randomised to receive either a 2 g metronidazole suppository or identical placebo per-operatively. Participants, doctors and investigators were blinded to treatment allocation. Participants were asked to complete a questionnaire about post-operative symptoms, visits to the general practitioner, antibiotic treatment, readmission to hospital, contraception and emotional response after one month. RESULTS: The prevalence of bacterial vaginosis was 29.3% (326/1,111). Intention-to-treat analysis showed that post-operative upper genital tract infection developed in 12/142 (8.5%) women allocated to metronidazole and 21/131 (16.0%) women randomised to placebo, a difference of 7.6% (95% confidence intervals -15.4 to +0.2%; relative risk 0.53. 0.27 to 1.03, P = 0.055). The effect of prophylaxis was similar when the analysis was restricted to women receiving the allocated treatment and with complete follow up. There was no difference in the risk of readmission to hospital and the frequencies of self reported symptoms in the two groups were similar. CONCLUSION: This randomised placebo-controlled trial among women with bacterial vaginosis provides weak evidence that metronidazole decreases the risk of upper genital tract infection after first trimester suction termination of pregnancy but a chance finding could not confidently be excluded. Large well-conducted randomised trials with long term outcome measures are now needed to determine the most effective antibiotic combinations and strategy for prevention of post-abortal pelvic infection.

Abortion, Induced↗
PubMed2001

Endoscopic fluorescence spectroscopy in the upper GI tract for the detection of GI cancer: initial experience.

OBJECTIVE: The aim of this study was to investigate autofluorescence spectroscopy using violet-blue excitation light for the in vivo diagnosis of GI cancer during routine endoscopy. METHODS: Fluorescence spectra were obtained from normal mucosa and cancerous lesions of the esophagus and stomach. The spectroscopic system used comprised a special light source capable of delivering either white or violet-blue light to induce autofluorescence of tissue via the endoscope. Endogenous fluorescence spectra emitted by the tissue were recorded with a fiberoptic probe and analyzed with a spectrographic detector system consisting of a polychromator with a photodiode array and an optical multichannel analyzer. The data of each spectrum were sampled within the range of 450-700 nm and stored in a personal computer. RESULTS: Esophageal squamous cell cancer, adenocarcinoma of the esophagus, and adenocarcinoma of the stomach show specific differences in the emitted fluorescence spectra compared with normal mucosa. CONCLUSIONS: Light-induced fluorescence spectroscopy might be a useful tool for the endoscopic in vivo detection of dysplasia and early carcinoma in the upper GI tract. Further trials are needed to test the validity of this new optical detection system.

Adenocarcinoma↗
PubMed2000

Light-induced autofluorescence spectroscopy for tissue diagnosis of GI lesions.

BACKGROUND: The present article describes light-induced autofluorescence spectroscopy using violet-blue excitation light for endoscopic in vivo measurements in the upper GI tract. The spectra of normal mucosa, cancer, and dysplastic lesions of the esophagus and stomach are presented and compared. METHODS: Over 120 spectra were obtained in 11 patients of normal mucosa and malignant lesions in the esophagus and stomach during routine endoscopy. A special light source capable of delivering either white or violet-blue light was used for the excitation of tissue auto-fluorescence via the endoscope. Endogenous fluorescence spectra emitted by the tissue were collected with a fiberoptic probe and analyzed with a spectrograph. After spectrographic measurements biopsies were taken for definitive classification of histopathologic status. RESULTS: As compared with normal mucosa, (pre) cancerous lesions were associated with special changes in the emitted fluorescence spectra. The spectrographic records were influenced by the intensity of the illumination and on the position of the probe (distance and angle). CONCLUSION: Fluorescence spectroscopy with a slightly modified conventional light source might be useful for the endoscopic detection of dysplasia and early-stage carcinoma in the upper GI tract. Prospective trials need to determine the sensitivity and specificity of this new method.

Adenoma↗
PubMed1999

Postal urine specimens: are they a feasible method for genital chlamydial infection screening?

BACKGROUND: A United Kingdom (UK) screening programme for Chlamydia trachomatis has recently been announced. Pilot projects involving the opportunistic testing of women attending health facilities are due to commence in several sites. There is a danger that this approach will fail to obtain adequate population coverage. The alternative--true systematic population screening--is generally assumed to be unfeasible. Studies in Denmark using postal urine specimens have challenged this assumption. No such studies have been reported from the UK. AIM: To assess the potential of urine specimens sent by post as the basis for a UK population screening strategy for genital chlamydial infection. METHOD: Two hundred patients (100 men, 100 women) aged 18 to 45 years were randomly sampled from the list of one urban group practice. Subjects were mailed an explanatory letter, a urine sample container, a sexual lifestyle questionnaire, and a prepaid return envelope. Non-responders were contacted by telephone; persistent non-responders were visited at home. Samples were tested for Chlamydia by DNA amplification and enzyme immunoassay. RESULTS: Sixty-four (32%) subjects were no longer living at their GP registered address. Of the remaining 136, 126 (93%) responded to the survey and 113 (83%) accepted the request for a urine sample and completed a questionnaire. Acceptance rates were similar for men and women and across age groups. Four samples (3%) were Chlamydia positive. CONCLUSION: Home mailed urine specimen collection in conjunction with a self-completed postal questionnaire is feasible. This could provide a viable basis both for determining population Chlamydia prevalence and for a UK Chlamydia population screening strategy. Overall cost effectiveness of such a strategy will depend on the cost of the test used. Comparative performance characteristics of the different currently available tests in this setting have yet to be fully determined.

Adolescent↗
PubMed1997

Hormonal factors and the laboratory detection of Chlamydia trachomatis in women: implications for screening?

One thousand and fifty-six new and re-registered consecutive women attending a genitourinary medicine clinic requiring speculum examination were screened for Chlamydia trachomatis by enzyme immunoassay (IDEIA, Dako Diagnostics Ltd). Of 1022 women who had results available for both cervix and urethra C. trachomatis was detected in 8.8% (89/1022) in any site, 2.3% (23/1022) in both sites, 4.9% (51/1022) at the cervix alone and 1.5% (15/1022) at the urethra alone. Thus sampling at the urethra increased detection by 17% (15/89). Analysis of 808 women with a regular menstrual cycle showed a significant association of combined oral contraceptive use, age and ectropion with the detection of C. trachomatis. The detection of C. trachomatis showed a significant variation with the menstrual cycle (P = 0.023) (relative risk (rr) 1.7 (95% confidence intervals (CI) 1.0-2.8)). It was detected significantly more often in the latter part. Stepwise logistic regression analysis revealed that ectropion and age were the stronger determinants of C. trachomatis detection and not oral contraceptive use or menstrual cycle. The variation in detection of C. trachomatis with the menstrual cycle was independently associated with combined oral contraceptive use and the lack of a cervical ectropion. The increased detection at the cervix was present after the second week in combined oral contraceptive users (P = 0.008) (rr = 2.3 (1.2-4.5)) but only after the 3rd week in women without an ectropion (P = 0.004) (rr = 2.7 (1.3-5.5)). Combined oral contraceptives, ectropion and youth, are markers for the carriage of C. trachomatis in the lower genital tract of women. It is also detected significantly more often in the latter part of the menstrual cycle in women who are oral contraceptive users.

Adolescent↗
PubMed1992

Increased gut parasympathetic activity and chronic diarrhoea in a patient with the acquired immunodeficiency syndrome.

A 25-year-old homosexual man with a 2-year history of watery diarrhoea and a 20 kg weight loss is described. He had been diagnosed HIV-1 antibody positive 6 years previously. Investigations excluded opportunist pathogens and other known causes of diarrhoea. A range of anti-diarrhoeal medication had been unsuccessful. Plasma levels of gastrointestinal and pancreatic peptides were normal and treatment with the somatostatin analogue, octreotide, which inhibits release of pancreatic/gut peptides, did not provide any benefit. Cardiovascular autonomic function tests revealed blunted pressor responses but no other abnormalities. Gastric emptying studies with a technetium labelled meal indicated rapid gastric emptying time. This was slowed by the anticholinergic drug, atropine. This suggested increased parasympathetic activity to the gut. He was, therefore, treated with the anti-cholinergic agent, propantheline bromide, which reduced the frequency and volume of stools. He put on weight and has remained well since. This case highlights the diagnostic challenge in HIV-associated chronic diarrhoea, the case for investigations of autonomic function, and the need for a therapeutic trial of anticholinergic drugs, when other measures have failed.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Nocardia infection in AIDS: a clinical and microbiological challenge.

A case of Nocardia asteroides pneumonia was diagnosed after death in a patient with AIDS. Six sputum cultures and one bronchoalveolar lavage fluid contained no pathogens, and no growth was obtained from one pleural fluid aspirate. None of these specimens was incubated for more than two days. Extended incubation for mycobacteria also failed to help in the diagnosis. N asteroides was isolated from pus taken from the lung cavity during the post mortem examination. It is suggested that if nocardiosis enters the differential diagnosis all specimens should be cultured for at least two weeks and the use of selective media be considered. This case highlights the need for clinicians to maintain a high index of suspicion for this pathogen.

Acquired Immunodeficiency Syndrome↗