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Biomedical subjects

E Frost

Publications and source records attributed to E Frost.

At least 19 recordsLinked to original sources

Mycoplasma genitalium: an organism commonly associated with cervicitis among west African sex workers.

OBJECTIVES: To identify the contribution of Mycoplasma genitalium to the aetiology of cervicitis in sub-Saharan Africa and its relative importance in the overall burden of sexually transmitted infections among female sex workers (FSW). METHODS: The study population consisted of FSW recruited in Ghana and Benin during the initial visit of a randomised controlled trial. A questionnaire was administered, a pelvic examination carried out, and cervical samples obtained for detection of M genitalium, Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis. Clinical signs potentially indicating cervicitis were cervical discharge, pus on the cervical swab, bleeding after sampling, and inflammatory cervix. RESULTS: Among 826 FSW, 26.3% were infected with M genitalium. N gonorrhoeae was strongly and independently associated with each of the four signs of cervicitis (adjusted odds ratios (AOR): 4.1 to 6.0). The AOR for C trachomatis were intermediate (1.3-4.1) and the AOR for M genitalium were lower (between 1.6 and 1.8) but statistically significant (p< or =0.05) for each sign. CONCLUSIONS: M genitalium is weakly associated with signs of cervicitis in west African FSW but is highly prevalent.

Adolescent↗

A novel candidate region for ALS on chromosome 14q11.2.

Sequence variations with biologic effect in ALS have been identified in the gene for vascular endothelial growth factor (VEGF). The gene for a related protein, angiogenin, lies on chromosome 14q11.2. Analysis of the angiogenin (ANG) gene in the authors' population has demonstrated a significant allelic association with the rs11701 single nucleotide polymorphism (SNP) and identified a novel mutation in two individuals with sporadic ALS that potentially inhibits angiogenin function. These observations propose a candidate region for ALS on chromosome 14q11.2 and suggest that other genes with similar function to VEGF may be important in the pathogenesis of ALS.

Aged↗

Low prevalence of cervical infections in women with vaginal discharge in west Africa: implications for syndromic management.

OBJECTIVES: To measure prevalence and risk factors for cervical infections among a large sample of women consulting for vaginal discharge in west Africa and to evaluate its syndromic management through a two visit algorithm. METHODS: In 11 health centres in Bénin, Burkina Faso, Ghana, Guinée, and Mali 726 women who presented with a vaginal discharge without abdominal pain and who denied being a sex worker (SW) were enrolled. Cervical samples were tested for the detection of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) with polymerase chain reaction (PCR) assays. All participants were treated with single dose (2 g) metronidazole and clotrimazole cream for 3 days. They were randomised to be told either to come back on day 7 only if there was no improvement in the discharge (group A), or to come back on day 7 regardless of response to treatment (group B). RESULTS: Overall, the prevalence of NG and CT was only 1.9% (14/726) and 3.2% (23/726) respectively. Risk factors previously recommended by the WHO were not associated with the presence of cervical infection, with the exception of the number of sex partners in the past 3 months. When taken together, these risk factors had a positive predictive value of only 6.4% to identify cervical infections. Prevalence of cervical infection was not higher in women who came back on day 7, regardless of the strategy used. Prevalence of NG/CT was lower in Ghana and Bénin (5/280, 1.8%), where comprehensive interventions for SW have been ongoing for years, than in the three other countries (27/446, 6.1%, p = 0.01). CONCLUSIONS: NG and CT infections are uncommon in west African women who consult for vaginal discharge and who are not SW. Syndromic management of vaginal discharge should focus on the proper management of vaginitis. The control of gonococcal and chlamydial infection should be redesigned around interventions focusing on sex workers.

Adolescent↗

Effect of a multidisciplinary amyotrophic lateral sclerosis (ALS) clinic on ALS survival: a population based study, 1996-2000.

BACKGROUND: In recent years, there has been a paradigm shift in the method of healthcare delivery to amyotrophic lateral sclerosis (ALS) patients with the emergence of multidisciplinary ALS clinics that cater exclusively for patients with this condition. The impact of multidisciplinary management has not been previously evaluated. METHODS: Using data from the Irish ALS Register, we conducted a prospective, population based study of all ALS cases diagnosed in Ireland over a five year period to evaluate the effectiveness of a multidisciplinary clinic on ALS survival. RESULTS: Eighty two (24%) patients attended the multidisciplinary ALS clinic, with the remaining 262 (76%) cases followed in a general neurology clinic. The ALS clinic cohort was an average of five years younger (60.1 v 65.6 years) and were more likely to receive riluzole than the general neurology cohort (99% v 61%). The median survival of the ALS clinic cohort was 7.5 months longer than for patients in the general neurology cohort (logrank = 15.4, p < 0.0001). Overall, one year mortality was decreased by 29.7%. Prognosis of bulbar onset patients was extended by 9.6 months if they attended the ALS clinic. Using multivariate analysis, attendance at the ALS clinic was an independent covariate of survival (HR = 1.47, p = 0.02). CONCLUSIONS: ALS patients who received their care at a multidisciplinary clinic had a better prognosis than patients attending a general neurology clinic. The data suggest that active and aggressive management enhances survival, particularly among ALS patients with bulbar dysfunction. The effect of clinic type must be considered in future clinical trials design.

Adult↗

Sexually transmitted infections in male clients of female sex workers in Benin: risk factors and reassessment of the leucocyte esterase dipstick for screening of urethral infections.

OBJECTIVES: (1) To assess risk factors for urethral infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among male clients of female sex workers (FSWs) in Benin; (2) to study the validity of LED testing of male urine samples compared to a highly sensitive gold standard (PCR) for the diagnosis of urethral infections with the organisms cited above. METHODS: Male clients of FSWs (n=404) were recruited on site at prostitution venues in Cotonou, Benin, between 28 May and 18 August 1998. A urine sample was obtained from each participant just before he visited the FSW, and tested immediately using a leucocyte esterase dipstick (LED) test. It was then tested for HIV using the Calypte EIA with western blot confirmation, and for C. trachomatis, N. gonorrhoeae, and T. vaginalis by PCR. After leaving the FSW's room, participants were interviewed about demographics, sexual behaviour, STI history and current symptoms and signs, and were examined for urethral discharge, genital ulcers, and inguinal lymphadenopathies. RESULTS: STI prevalences were: C. trachomatis, 2.7%; N. gonorrhoeae, 5.4%; either chlamydia or gonorrhoea 7.7%; T. vaginalis 2.7%; HIV, 8.4%. Lack of condom use with FSWs and a history of STI were independently associated with C. trachomatis and/or N. gonorrhoeae infection. Over 80% of these infections were in asymptomatic subjects. The overall sensitivity, specificity, positive and negative predictive values of the LED test for detection of either C. trachomatis or N. gonorrhoeae were 48.4%, 94.9%, 44.1%, and 95.7%, respectively. In symptomatic participants (n=22), all these parameters were 100% while they were 47.4%, 94.7%, 37.5%, and 96.4% in asymptomatic men (n=304). CONCLUSIONS: Since most STIs are asymptomatic in this population, case finding programmes for gonorrhoea and chlamydia could be useful. The performance characteristics of the LED test in this study suggest that it could be useful to detect asymptomatic infection by either C. trachomatis or N. gonorrhoeae in high risk men.

Adolescent↗

Mycoplasma genitalium is not associated with adverse outcomes of pregnancy in Guinea-Bissau.

OBJECTIVE: To evaluate the impact of Mycoplasma genitalium on the outcome of pregnancy. METHODS: Cervical samples from women who had previously participated in a case-control study (designed to assess the impact of syphilis and HIV-2 on the outcome of pregnancy in Guinea-Bissau) were processed using a PCR assay to detect the presence of M genitalium. Controls were women who had delivered a term neonate with a birth weight over 2500 g. Cases were classified into four groups of mothers according to the outcome of pregnancy: stillbirths, spontaneous abortions, premature deliveries, and small for gestational age (SGA) babies. RESULTS: Among the 1014 women included in this study, 6.2% were infected with M genitalium. M genitalium infection was not significantly associated with any of the adverse outcomes of pregnancy studied. Odds ratios (OR) for premature or SGA delivery in the presence of M genitalium infection were 1.37 (95% CI 0.69 to 2.60) and 0.44 (95% CI 0.01 to 2.75), respectively. For abortions and stillbirths, OR were respectively 0.61 (95% CI 0.07 to 2.51) and 1.07 (95% CI 0.42 to 2.42). CONCLUSION: M genitalium appears not to have a deleterious impact on the outcome of pregnancy.

Adolescent↗

HIV infection among sex workers in Accra: need to target new recruits entering the trade.

OBJECTIVE: Description of the epidemiology of HIV infection among sex workers (SW) in Accra, Ghana. METHODS: In all, 1013 SW working out of their homes ( seaters ) or finding customers in bars, hotels, brothels or on the street ( roamers ) were interviewed and tested for HIV. RESULTS: Overall, prevalence of HIV infection was nearly 50% (506 of 1013), varying from 26% (133 of 507) among the roamers to 74% (368 of 496) among the seaters. Profound differences were noted between these two categories of SW with regard to age, number of clients per day, price per instance of intercourse, condom use, and other characteristics. Respectively, 27% and 58% of roamers and seaters were infected with HIV within their first 6 months of sex work, despite a limited number of unprotected sex acts with seropositive clients. Independent risk factors for HIV infection varied between types of SW: age among the roamers; region of origin and duration of sex work among the seaters; number of clients per day, and presence of current or past genital ulcer and gonococcal cervicitis in both groups. CONCLUSION: In Accra, considerable heterogeneity exists in the population of SWs. In both categories of SW, new recruits become rapidly infected with HIV after entering the trade. The 25-fold higher prevalence of HIV among SWs than in the general adult population suggests that in Accra, as in many cities of West Africa, a high fraction of new cases of HIV infection continue to be acquired from SWs. Intervention programs targeting SW should be an essential component of national AIDS control strategies. Special efforts should be made to identify and offer preventive services to new sex workers.

Adolescent↗

Engineering of complex polyketide biosynthesis--insights from sequencing of the monensin biosynthetic gene cluster.

The biosynthesis of complex reduced polyketides is catalysed in actinomycetes by large multifunctional enzymes, the modular Type I polyketide synthases (PKSs). Most of our current knowledge of such systems stems from the study of a restricted number of macrolide-synthesising enzymes. The sequencing of the genes for the biosynthesis of monensin A, a typical polyether ionophore polyketide, provided the first genetic evidence for the mechanism of oxidative cyclisation through which polyethers such as monensin are formed from the uncyclised products of the PKS. Two intriguing genes associated with the monensin PKS cluster code for proteins, which show strong homology with enzymes that trigger double bond migrations in steroid biosynthesis by generation of an extended enolate of an unsaturated ketone residue. A similar mechanism operating at the stage of an enoyl ester intermediate during chain extension on a PKS could allow isomerisation of an E double bond to the Z isomer. This process, together with epoxidations and cyclisations, form the basis of a revised proposal for monensin formation. The monensin PKS has also provided fresh insight into general features of catalysis by modular PKSs, in particular into the mechanism of chain initiation.

Biotechnology↗

Aetiology of urethral discharge in Bangui, Central African Republic.

OBJECTIVES: To determine the aetiology of urethritis in Bangui, Central African Republic. METHODS: 410 men presenting with urethral discharge and 100 asymptomatic controls were enrolled. Urethral swabs were obtained and processed by gonococcal culture and polymerase chain reaction for the detection of Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Trichomonas vaginalis, and Ureaplasma urealyticum. RESULTS: In multivariate analyses, M genitalium and C trachomatis were significantly associated with urethral discharge when comparing cases of non-gonococcal urethritis (NGU) with controls. T vaginalis was also more common in cases than in controls, but this reached statistical significance only among cases in whom N gonorrhoeae was also detected. U urealyticum was not associated with urethritis. The gonococcus was found in 69% of cases of urethral discharge. M genitalium was the predominant pathogen in patients with NGU, being found in 42% (53/127) of such patients while C trachomatis was found in only 17% (22/127). T vaginalis was found in 18% (23/127) of patients with NGU, but also in 15% (43/283) of patients with gonococcal urethritis, and two thirds of patients with T vaginalis also had the gonococcus. Multiple infections were common. M genitalium caused a syndrome similar to chlamydial urethritis, with a less severe inflammation than in gonococcal infection. No behavioural or clinical characteristic could discriminate between the various aetiological agents. CONCLUSIONS: M genitalium is more prevalent than C trachomatis and is the most common cause of NGU in BANGUI: It causes a syndrome similar to chlamydial urethritis. T vaginalis is weakly associated with urethritis, and is often found along with other pathogens.

Adult↗

Etiology of urethral discharge in West Africa: the role of Mycoplasma genitalium and Trichomonas vaginalis.

OBJECTIVE: To determine the etiological role of pathogens other than Neisseria gonorrhoeae and Chlamydia trachomatis in urethral discharge in West African men. METHODS: Urethral swabs were obtained from 659 male patients presenting with urethral discharge in 72 primary health care facilities in seven West African countries, and in 339 controls presenting for complaints unrelated to the genitourinary tract. Polymerase chain reaction analysis was used to detect the presence of N. gonorrhoeae, C. trachomatis, Trichomonas vaginalis, Mycoplasma genitalium, and Ureaplasma urealyticum. FINDINGS: N. gonorrhoeae, T. vaginalis, C. trachomatis, and M. genitalium--but not U. urealyticum--were found more frequently in men with urethral discharge than in asymptomatic controls, being present in 61.9%, 13.8%, 13.4% and 10.0%, respectively, of cases of urethral discharge. Multiple infections were common. Among patients with gonococcal infection, T. vaginalis was as frequent a coinfection as C. trachomatis. M. genitalium, T. vaginalis, and C. trachomatis caused a similar clinical syndrome to that associated with gonococcal infection, but with a less severe urethral discharge. CONCLUSIONS: M. genitalium and T. vaginalis are important etiological agents of urethral discharge in West Africa. The frequent occurrence of multiple infections with any combination of four pathogens strongly supports the syndromic approach. The optimal use of metronidazole in flowcharts for the syndromic management of urethral discharge needs to be explored in therapeutic trials.

Adult↗

Postoperative nausea and vomiting--a review.

Post operative nausea and vomiting (PONV) remains an unpleasant and persistent problem for patients undergoing surgery. In fact PONV are among the most important factors contributing to delay in discharge of patients and an increase in unanticipated admissions after ambulatory surgery. Anesthesia providers are most often blamed for PONV, sometimes rightfully so, many times wrongly so. PONV is a multifactorial issue involving many physiological and biological mechanisms. As the trend towards ambulatory surgery increases, PONV continues to pose serious challenges for anesthesia providers because the potential cost savings of performing surgeries on an ambulatory basis may be negated by unanticipated hospital admission. Although PONV may be unavoidable in some patients for reasons we do not fully understand, there are risk factors that can be identified. As anesthesiologists it is essential for us to understand the mechanisms involved in nausea and vomiting and the available perioperative treatment options. We must do whatever we can to prevent and treat PONV and improve patient outcome for both medical and economic reasons.

Anesthetics↗

Management of sexually transmitted diseases and HIV prevention in men at high risk: targeting clients and non-paying sexual partners of female sex workers in Benin.

OBJECTIVES: Male clients of female sex workers have rarely been specific targets for HIV/sexually transmitted diseases (STD) interventions in sub-Saharan Africa. We assessed the effectiveness of outreach methodology for contacting sexual partners of female sex workers for purposes of HIV/STD prevention in Cotonou, Benin. DESIGN AND METHODS: In collaboration with owners/managers, outreach personnel and female sex workers, 404 clients were recruited on-site at prostitution venues, and provided urine samples for leukocyte esterase dipstick (LED), STD and HIV testing before having sex with female sex workers. After having sex they underwent an interview and physical examination. No payment was made for study participation. Prostitution site personnel (n = 41) and boyfriends of female sex workers (n = 56) were also recruited. RESULTS: In all 68% of the clients approached agreed to participate. On-site LED testing and free STD treatment were important factors in participation. HIV-1 prevalence was several-fold higher than in the general population in Cotonou, at 8.4, 12.2 and 16.1% in clients, personnel and boyfriends respectively, and was associated with increasing age and lack of condom use with female sex workers. Condom use rates by clients with female sex workers were non-negligible but sub-optimal, and low with regular partners. Approximately one-third of clients with regular partners also had other non-female sex worker sex partners. Boyfriends of female sex workers are of particular concern due to high numbers of partners, very low condom use rates and high HIV prevalence. CONCLUSIONS: Study findings indicate that male sex partners of female sex workers form a 'bridging population' for HIV/STD transmission both to female sex workers, as well as from female sex workers to the general population of women, particularly regular female partners.

Adult↗

Amyotrophic lateral sclerosis mimic syndromes: a population-based study.

BACKGROUND: The Irish ALS Register is a population-based register of the epidemiological characteristics of amyotrophic lateral sclerosis (ALS) in the republic of Ireland. OBJECTIVE: To describe the clinical and demographic details of those patients included in the Irish ALS Register who were incorrectly diagnosed as having ALS (patients who were ultimately rediagnosed as having an "ALS mimic syndrome"). METHODS: The medical records of each patient referred to the register are routinely reviewed and, where possible, patients are examined by our group during their illness. RESULTS: Between January 1, 1993, and December 31, 1997, 32 patients (representing 7.3% of 437 referrals) were rediagnosed as having a condition other than ALS. The median age at onset for these 32 patients was 56.0 years (range, 19.5-85.8 years) for men and 53.5 years (range, 39.5-70.4 years) for women. Twenty-nine patients (91%) presented with symptoms referable to the limbs, and the remainder presented with symptoms involving the bulbar musculature. Multifocal motor neuropathy was the most common condition mistaken for ALS, accounting for 7 cases (22%), followed closely by Kennedy disease (4 cases [13%]). Factors leading to diagnostic revision included evolution of atypical symptoms, results of specific investigations, and failure of symptoms to progress. Twenty-seven (84%) of the patients with an ALS mimic syndrome fulfilled the El Escorial criteria for either "suspected" or "possible" ALS, 4 (13%) met the criteria for probable ALS, and 1 (3%) had definite ALS. CONCLUSIONS: The application of the El Escorial diagnostic criteria may facilitate early recognition of non-ALS cases. Misdiagnosis of ALS remains a common clinical problem despite the increased availability of investigations and a greater awareness among neurologists of potential diagnostic pitfalls.

Adult↗

Clinical features of amyotrophic lateral sclerosis according to the El Escorial and Airlie House diagnostic criteria: A population-based study.

BACKGROUND: The El Escorial and the revised Airlie House diagnostic criteria for amyotrophic lateral sclerosis (ALS) classify patients into categories reflecting different levels of diagnostic certainty. We conducted a prospective, population-based study of the natural course of ALS in the Republic of Ireland during a 6-year period to examine the utility of these ALS diagnostic criteria. METHODS: Using data from the Irish ALS Register, we studied the clinical features of all patients diagnosed as having ALS in Ireland throughout their illness. RESULTS: Between 1993 and 1998, 388 patients were diagnosed as having ALS. Forty percent of patients reported bulbar-onset symptoms. Disease progression occurred over time: at last follow-up, 75% of all patients had bulbar signs, compared with 59% at diagnosis. When the El Escorial criteria were applied, more than half of patients (218 [56%]) had definite or probable ALS at diagnosis. Of the 165 possible and suspected ALS cases at diagnosis (trial ineligible), 110 (67%) were trial eligible at last follow-up. Of the 254 patients who had died, 229 (90%) had definite or probable ALS, whereas 25 patients (10%) remained trial ineligible at death. El Escorial category at diagnosis was not a significant prognostic indicator. Use of the Airlie House criteria had no effect on the median time from symptom onset to trial eligibility (12.9 vs 12.8 months). CONCLUSIONS: The El Escorial and Airlie House diagnostic criteria are excessively restrictive. Furthermore, levels of diagnostic certainty cannot be used as prognostic indicators. Arch Neurol. 2000;57:1171-1176

Adult↗

Incidence and prevalence of ALS in Ireland, 1995-1997: a population-based study.

BACKGROUND: We conducted a prospective, population-based study of ALS in the Republic of Ireland for the 3-year period 1995 to 1997. METHODS: To ensure complete case ascertainment, multiple sources of information were used, including consultant neurologists, neurophysiologists, primary care physicians, and the Irish Motor Neuron Disease Association. The El Escorial diagnostic criteria for ALS were applied to all cases enrolled on the register and each patient was regularly followed up during his or her illness. RESULTS: Between January 1, 1995, and December 31, 1997, 231 patients were diagnosed with possible, probable, or definite ALS, including 133 men (57.6%) and 98 women (42.4%). The average annual incidence rate was 2.1 per 100,000 person-years (95% CI, 1.8 to 2.4), and 2.8 per 100,000 person-years for the population older than 15 years (95% CI, 2.4 to 3.1). The incidence rate was higher for men, being 2.5 per 100,000 person-years (95% CI, 2.0 to 2.9), than for women, at 1.8 per 100,000 person-years (95% CI, 1.5 to 2.2), and increased with age for both sexes. The median age at onset was 64.2 years for men and 67.8 years for women. On December 31, 1996, the crude prevalence was 4.7 per 100,000 of the total population (95% CI, 4.0 to 5.5), and 6.2 per 100,000 for the population older than 15 years (95% CI, 5.3 to 7.1). Adjusting to the 1996 Irish population as standard, the incidence of ALS in Ireland during the 3-year study period is the third highest reported to date. CONCLUSIONS: There was a trend toward a higher incidence of ALS in the northwestern region of Ireland, although the numbers of cases involved were small and further study is required.

Age Distribution↗

Service provision for patients with ALS/MND: a cost-effective multidisciplinary approach.

Optimal management of patients with ALS/MND requires a team approach, with early referral to paramedical services for clinical assessment and prompt intervention. As the condition progresses, a flexible approach to management must be adopted by the medical team, with an ability to intervene at very short notice. We have developed an efficient multi-disciplinary clinic that services the ALS/MND population of Ireland by combining the existing infrastructure of community services with a hospital-based specialist clinic. The clinic operates on a weekly basis, and is staffed by a core team including a neurologist, a liaison nurse, and the director of the ALS/MND Association. On-site and same-day physiotherapy, occupational therapy and speech therapy is available, as is pulmonary evaluation. All patients utilising the clinical services are automatically included on the Irish Register of Motor Neurone Disease, and are tracked by the liaison nurse. The core members of the clinic interact regularly with paramedical staff within the community, ensuring that necessary community services are made available within 1-2 weeks of the clinic visit. Equipment necessary for the patient's well being is made available free of charge by the Irish Motor Neurone Disease Association, following an appropriate request from the regional para-medical staff. We have thus demonstrated that an effective multi- disciplinary care service for ALS/MND can be developed at modest cost by close personal liaison between the existing health care structures and core members of a multidisciplinary team.

Amyotrophic Lateral Sclerosis↗

Expression of alpha vbeta3 and alpha vbeta8 integrins during oligodendrocyte precursor differentiation in the presence and absence of axons.

We have shown previously that switching of the alpha v-associated beta1 and beta5 integrin subunits during differentiation of myelin-forming oligodendrocytes may regulate important aspects of cell behaviour such as migration (Milner et al., 1996: J Neurosci 16:7240-7252). In this study we have examined the developmental regulation of other alpha v-associated beta subunits in oligodendroglial cell cultures and also the control of their expression by neurons, using xenocultures to distinguish glial and neuronal integrins. We have found that oligodendroglia express alpha vbeta8 in addition to the previously-described alpha vbeta1, alpha vbeta3, and alpha vbeta5. Beta8 and beta3 together comprise the 80kD band seen in alpha v immunoprecipitations that represents the most abundant alpha v-associated beta subunit and show reciprocal patterns of expression during development. Alpha vbeta8 is expressed at high levels on oligodendrocyte precursors and differentiated oligodendrocytes but diminishes during the intermediate stages of differentiation. Alpha vbeta3, in contrast, shows an opposite pattern of expression, with the highest levels seen at the intermediate stages of differentiation and little expression on either oligodendrocyte precursors and differentiated oligodendrocytes. The expression of alpha vbeta3 is not altered by coculture with neurons, unlike that of alpha vbeta8, in which the decrease seen at the intermediate stages of differentiation is less marked in the presence of neurones. Our results confirm that switching of alpha v-associated beta subunits is an important feature of oligodendrocyte differentiation and suggest that alpha vbeta8 and alpha vbeta3 have distinct functions during myelination.

Animals↗