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Biomedical subjects

T Rhodes

Publications and source records attributed to T Rhodes.

At least 19 recordsLinked to original sources
PubMed2005

Prevalence of, and risk factors for, hepatitis C virus infection among recent initiates to injecting in London and Glasgow: cross sectional analysis.

Our aim was to compare the prevalence of antibody to hepatitis C virus (anti-HCV) among recently initiated injecting drug users (IDUs) in London and Glasgow, and to identify risk factors which could explain differences in prevalence between the cities. Complementary studies of community recruited IDUs who had initiated injection drug use since 1996 were conducted during 2001-2002. Data on HCV risk behaviours were gathered using structured questionnaires with identical core questions and respondents were asked to provide an oral fluid specimen which was tested anonymously for anti-HCV but was linked to the questionnaire. Sensitivities of the anti-HCV assays for oral fluid were 92-96%. Prevalence of anti-HCV was 35% (122/354) in London and 57% (207/366) in Glasgow (P < 0.001). Multifactorially, factors significantly associated with raised odds of anti-HCV positivity were increasing length of injecting career, daily injection, polydrug use, having had a needlestick injury, and having served a prison sentence. In addition lower odds of anti-HCV positivity were associated with non-injection use of crack cocaine and recruitment from drug agencies. After adjustment for these factors, the increased odds of anti-HCV associated with being a Glasgow IDU were diminished but remained significant. HCV continues to be transmitted among the IDU population of both cities at high rates despite the availability of syringe exchange and methadone maintenance. Effectiveness of harm reduction interventions may be compromised by inadequate coverage and failure to reduce sufficiently the frequency of sharing different types of injecting equipment, as well as the high background prevalence of HCV, and its high infectivity. Comprehensive action is urgently required to reduce the incidence of HCV among injectors.

Adult↗
PubMed2003

Distribution of the Brief Male Sexual Inventory in community men.

The objectives of the study were to characterize male sexual functioning as related to age in community-dwelling older men. In 1989, a random sample of men aged 40-79 y (n=2115) without prior prostate surgery, prostate cancer, or other conditions known to affect voiding function (except benign prostatic hyperplasia) was invited (55% agreed) to participate in the Olmsted County Study of Urinary Symptoms and Health Status Among Men. In 1996, a previously validated male sexual function questionnaire was administered to the cohort. The questionnaire has 11 questions measuring sexual drive (two questions); erectile function (three) and ejaculatory function (two), as well as assessing problems with sex drive, erections, or ejaculation (three); and overall satisfaction with sex life (one). Each question is scored on a scale of 0-4, with higher scores indicating better functioning. Cross-sectional age-specific means (+/-s.d.) for drive, erections, ejaculation, problems, and overall satisfaction declined from 5.2 (+/-1.5), 9.8 (+/-2.5), 7.4 (+/-1.4), 10.7 (+/-2.2), and 2.6 (+/-1.0), respectively, for men in their 40s to 2.4 (+/-1.6), 3.3 (+/-3.4), 3.6 (+/-3.2), 7.7 (+/-3.8), and 2.1 (+/-1.2) for men 70 y and older (all P<0.001). The cross-sectional decline in function with age was not constant, with age-related patterns differing by domain. The percentage of men reporting erections firm enough to have intercourse in the past 30 days declined from 97% (454/468) among those in their 40s to 51% (180/354) among those in their 80s (P&<0.001). In age-adjusted analyses, men reporting regular sexual partners had statistically significantly higher levels of sex drive, erectile function, ejaculatory function, and overall satisfaction than those who did not report regular sexual partners. Sexual drive, erectile functioning, ejaculatory functioning, and overall sexual satisfaction in men show somewhat differing cross-sectional patterns of decline with advancing age. Active sexual functioning is maintained well into the 80s in a substantial minority of community-dwelling men.

Age Distribution↗
PubMed2001

Prostate volume and prostate-specific antigen in the absence of prostate cancer: a review of the relationship and prediction of long-term outcomes.

BACKGROUND: The risk for long-term outcomes associated with benign prostatic hyperplasia (BPH) has not been well characterized. Untreated, BPH can lead to complications and negative outcomes, such as deterioration of bladder function, urinary tract infection, acute urinary retention (AUR), and surgery. METHODS: A literature review was conducted to summarize the results of studies investigating the relationship of prostate volume and PSA with prediction of long-term outcomes in the absence of prostate cancer. RESULTS: In the studies reviewed, men with moderate to severe symptoms, depressed uroflow, prostatic enlargement and elevated PSA were at greater risk for developing subsequent AUR or surgery. Men with prostatic enlargement had a 3-fold higher risk for acute urinary retention and were 4 times more likely to have had any treatment for BPH. CONCLUSIONS: The results of these studies may assist physicians in discussing treatment options as well as long-term complications with patients.

Clinical Trials as Topic↗
PubMed2001

Interexaminer reliability and validity of a three-dimensional model to assess prostate volume by digital rectal examination.

OBJECTIVES: To evaluate the interexaminer reliability and accuracy compared with transrectal ultrasound (TRUS) of a three-dimensional (3D) model and other scales to improve the estimation of prostate volume by digital rectal examination (DRE). METHODS: Volunteers from a urology clinic (n = 121) were examined independently by three examiners with different levels of experience in randomized order. During DRE, the examiners estimated the prostate size in increments of 5 g, using various rating scales and a 3D sizing model, without access to the findings of the other investigators. TRUS was then performed by each examiner. RESULTS: The 121 volunteers were 39 to 82 years old, with a mean +/- SD total TRUS prostate size of 35.9 +/- 27.2 g. The DRE size estimates ranged from 15 to 100 g across all examiners and patients. The interexaminer reliability across examiners for the best DRE prostate size estimates (in grams) was 0.78 (95% confidence interval 0.70 to 0.84), and the correlation coefficients (r(s)) with the TRUS volume ranged from 0.61 to 0.72 for the three examiners. A 3D model showed good reliability (intraclass correlation coefficient 0.86, 95% confidence interval 0.75 to 0.93), and correlated well with the TRUS volume (r(s) = 0.67 to 0.75). Other scales showed fair reliability (0.58 to 0.68) and correlated with the TRUS measurements (0.57 to 0.67). The area under the receiver operating characteristic curve to identify prostate volumes greater than 40 g ranged from 0.78 to 0.90 for DRE estimates (in grams) and 0.69 to 0.89 for the 3D model. CONCLUSIONS: DRE size estimates and TRUS volume were moderately to highly correlated in men without prostate cancer. A 3D sizing model showed comparable reliability and correlation with TRUS. Although the DRE estimates generally tend to underestimate the TRUS-measured prostate volume, these tools may be useful in identifying men with enlarged prostate glands.

Adult↗
PubMed2001

Lower urinary tract symptoms, prostate volume and uroflow in norwegian community men.

OBJECTIVE: To describe lower urinary tract symptoms, prostate volume and peak urinary flow rate, and investigate the relationships among urological variables in a community sample of Norwegian men. MATERIALS AND METHODS: A cross-sectional study of 611 men, aged 55-70 years, who underwent a clinical urological examination including uroflowmetry, residual urine measurement, and transrectal ultrasonography of the prostate. All the men completed a questionnaire which included the International Prostate Symptom Score (IPSS). RESULTS: Severe symptoms were reported by 5%, while 23.6% reported moderate symptoms, and the overall median IPSS was 4 (q1 = 25th percentile, 1; q3 = 75th percentile, 9). The median peak flow rate was 15 ml/s (q1 = 11; q2 = 22) while median prostate volume was 30 cm(3) (q1 = 23; q3 = 38), with little variation evident across the narrow age range of 55-70 years. A positive modest correlation (r = 0.176) was found between IPSS and prostate volume, and a negative correlation between IPSS and peak flow rate (r = -0.278). There was a modest correlation between body mass index (BMI) and prostate size, but no significant correlation between BMI and IPSS. CONCLUSION: In this population-based study, moderate lower urinary tract symptoms were reported by 24% and severe symptoms by 5% of community men. The distribution of lower urinary tract symptoms, prostate volume and peak urinary flow rate in Norwegian men is comparable to that described in similar studies conducted in Spain, Holland and USA.

Aged↗
PubMed2001

Interexaminer reliability of transrectal ultrasound for estimating prostate volume.

PURPOSE: We investigated the interexaminer reliability of transrectal ultrasound measurement of total prostate and transition zone volume among 3 examiners with various levels of experience. MATERIALS AND METHODS: A total of 121 patients 39 to 82 years old (average plus or minus standard deviation 60.7 +/- 10.3) from a single urology clinic volunteered to participate. Patients with prostate cancer, previous prostate surgery or recent invasive prostatic examination were excluded from study. Each individual was examined independently by each of 3 examiners with various levels of experience, including an attending urologist, a PGY-2 resident in the second year of general surgery before urology training and a PGY-4 resident in the second year of urology training. Transrectal ultrasound was performed in each case by each examiner in pre-specified random order. RESULTS: Mean total prostate and transition zone volume was 35.9 +/- 27.2 and 15.6 +/- 18.8 ml., respectively. Interexaminer agreement or reliability of the ultrasound measurements was high for total prostate and transition zone volume (intraclass correlation 0.96, 95% confidence interval [CI] 0.95 to 0.97 and 0.93, 95% CI 0.90 to 0.95, respectively). For individual prostatic dimensions reliability estimates were 0.78 to 0.86, while for transition zone dimensions reliability was 0.85 to 0.90. Total prostate volume reliability was higher for prostate volume greater than 40 ml. versus smaller prostates (intraclass correlation 0.95, 95% CI 0.90 to 0.97 versus 0.77, 95% CI 0.67 to 0.84). Mean differences in transrectal ultrasound measurements by different examiners were highest for the resident with least experience. CONCLUSIONS: The reliability of transrectal ultrasound measured total prostate and transition zone volume is high for examiners with different levels of experience at this institution. Reliability in patients without prostate cancer appears to be better for larger volume prostates and for examiners with more experience.

Adult↗
PubMed2000

Origins of an epidemic: the methodological and political emergence of rapid assessment.

The recent emergence of rapid assessment as a public health tool in the drug and alcohol field has been a relatively ahistorical process. The lack of such an explicit historical biography is understandable - the findings and impact of rapid assessment have rarely made their way into mainstream journals. However, its continued absence presents the manifest danger of an inward-looking field. This paper describes the development of rapid assessment during the past two decades, with a detailed focus on the emergence of rapid assessment in the drug and alcohol field. This focuses on the central role played by international agencies during the 1980s and 1990s, and the development of rapid methodologies by the World Health Organization to prevent epidemics of HIV among injecting drug users, and the use of rapid methodologies by the United Nations International Drug Control Programme to instruct drug policy reform. The paper also describes key events in other fields including: the emergence of the first formal rapid methodologies in the late 1970s, and the production of the first formal guidelines on conducting rapid assessment during the mid-1980s. The paper concludes by highlighting common challenges that rapid methodologies have faced throughout their history.

Journal Article↗
PubMed2000

Immunohistochemical detection of steroid receptors in breast cancer: a working protocol. UK Receptor Group, UK NEQAS, The Scottish Breast Cancer Pathology Group, and The Receptor and Biomarker Study Group of the EORTC.

The biochemical assay for the oestrogen receptor has shown the clinical value of knowing the concentration of the receptor within tissue. The immunohistochemical assay is rapidly taking over from the biochemical assay. Therefore, it is vital to have an equivalent scoring system that will have the same predictive value. This paper reports both a practical protocol and a scoring system that should achieve this aim. This approach should be applicable to many more biomarkers detected by immunohistochemistry.

Biomarkers, Tumor↗
PubMed2000

Male-pattern hair loss in Norwegian men: a community-based study.

BACKGROUND: A Norwegian community study was conducted as an add-on to a large general health survey in Trondlag County, Norway, to characterize the cross-sectional relationship of patient perceptions with the degree of hair loss. METHODS: All members of the community were invited to participate in the general health survey and male participants, aged 20-50 years (n = 7,250), regardless of their degree of hair loss, were asked to complete a mail-based questionnaire. The questionnaire measured satisfaction with hair appearance, self-reported degree of hair loss, self-assessment of Norwood/Hamilton hair pattern, bother due to hair loss as well as concern about getting older due to hair loss, and included the SF-12 general health status questionnaire. RESULTS: Respondents (n = 4, 101) rated their hair loss on a 7-point, textual scale that ranged from 'a full head of hair' to 'I am bald'. The majority (63%) of participants reported at least a little hair loss and 27% reported moderate to severe loss. Using the Norwood/Hamilton hair patterns, participants rated themselves as class II (25.5%), III (8.6%), IV (8. 8%) or V or worse (19.5%). Relative to men without hair loss, a greater proportion of men with hair loss reported being bothered (20. 5 vs. 2.3%), concerned about growing older (43.4 vs. 10.6%) and dissatisfied with overall hair appearance (22.6 vs. 94%, all p< or =0.001). Men with hair loss also reported greater levels of perceived noticeability of hair thinning to others. CONCLUSIONS: A high proportion of Norwegian men aged 26-50 years self-reported having at least some hair loss. Results suggest that men who perceive themselves as having greater hair loss are more bothered by their hair loss, more dissatisfied with the appearance of their hair and have greater concern about getting older and losing more hair.

Adult↗
PubMed2000

Longitudinal changes in peak urinary flow rates in a community based cohort.

PURPOSE: We describe longitudinal changes in peak urinary flow rates in community dwelling men in Olmsted County, Minnesota. MATERIALS AND METHODS: A cohort of 2,115 men 40 years old or older was randomly selected from the Olmsted County, Minnesota population. Peak urinary flow rates and the American Urological Association symptom index were assessed in all men at baseline and biennially, and in a 25% random subsample prostate volume was determined by transrectal ultrasonography. The annualized percentage change in peak urinary flow rate (slope) was assessed for 492 men in the subsample during 6 years of followup. RESULTS: Median peak urinary flow rate slope was -2.1% per year (25th percentile -4.0, 75th percentile -0.6). Peak urinary flow rate declined more rapidly with decreasing baseline rate, and increasing baseline age, prostate volume and symptom severity (all p = 0.001). When the variables were simultaneously adjusted for each other, a rapid decline (negative slope 4.5% or greater per year) was more likely in men 70 years old or older (odds ratio 46.4, 95% confidence intervals 16.8, 127.7) and those with a rate less than 10 ml. per second (42.0, 14.1, 125.3) at baseline compared to those 40 to 49 years old and those with a rate of 15 ml. or greater, respectively. Prostate volume and symptom severity were not statistically significant predictors of a rapid decline in peak urinary flow rate when variables were considered simultaneously. CONCLUSIONS: Despite variability in measurement of peak urinary flow rate, a consistent decline was observed when measured longitudinally in a community based cohort. Furthermore, this decline was associated with impairments in other physiological and anatomical measures of lower urinary tract function in an unselected cohort of men.

Adult↗
PubMed2000

The effects of hair loss in European men: a survey in four countries.

Despite the high prevalence and the accepted psychological aspects of male pattern hair loss, few have characterized the effects of hair loss in representative samples of men in different countries. A representative sample of households in 4 European countries (France, Germany, Italy and the United Kingdom) was contacted by an interviewer and resident males 18-40 years of age (n = 1,717) completed a questionnaire designed specifically to evaluate attitudes to hair loss. The questionnaire was comprised of 78 questions translated and pilot-tested using standard methodology into each local language. Questionnaires queried about self-rated hair loss, satisfaction with hair appearance, noticeability of hair loss to others, and bother, concerns and perceptions about hair loss, as well as general physical health (the SF-12 questionnaire) plus three additional questions about mental health. The self-reported degree of hair loss in men was statistically significantly associated (p < 0.001) with all hair-loss specific effects measured, except "limiting job opportunities". The impact of hair loss was generally consistent in the four countries surveyed, although less pronounced in the United Kingdom. Age was significantly correlated with hair loss (rs = 0.34, p < 0.001). Men with greater hair loss were more bothered, more concerned about looking older due to their hair loss, and less satisfied with their hair appearance. Male pattern hair loss has significant negative effects on hair-loss specific measures in men 18 to 40 years of age in France, Italy, Germany and the UK. The degree that hair loss is perceived as noticeable to others appears to be a significant contributor to these negative effects.

Adolescent↗
PubMed1999

Transient kinetic analysis of N-phenylmaleimide-reacted myosin subfragment-1.

Alkylation of myosin's Cys-707 (SH1) and Cys-697 (SH2) has profound consequences for myosin's ability to interact with actin and hydrolyze MgATP. Pre-steady-state measurements of myosin-S1 alkylated at SH1 and SH2 by N-phenylmaleimide (NPM) in the presence of ATP were taken to identify the steps of the reaction that are altered. It was found that the rate constant most affected by this modification is the apparent rate of the ATP hydrolysis step. This rate constant is reduced 20000-fold, an effect comparable in magnitude to the effect of the same modification on the binding of MgATP to S1 or acto-S1 [Xie, L., and Schoenberg, M. (1998) Biochemistry 37, 8048]. In contrast, the rate constants of phosphate release and dissociation of acto-S1 by ATP were reduced <20-fold. For unmodified S1, the enhancement of fluorescence seen after addition of ATP had the same rate constant as the ATP hydrolysis step (S1.ATP if S1.ADP.Pi) measured by single-turnover experiments in a quench-flow experiment. This is consistent with results previously observed [Johnson, K. A., and Taylor, E. W. (1978) Biochemistry 17, 3432]. However, NPM-modified S1 exhibited virtually no fluorescence enhancement upon ATP binding. This provides further evidence that M.ATP is the predominant intermediate of NPM-S1-catalyzed ATP hydrolysis.

Actins↗
PubMed1999

The M.ADP.Pi state is required for helical order in the thick filaments of skeletal muscle.

The thick filaments of mammalian and avian skeletal muscle fibers are disordered at low temperature, but become increasingly ordered into an helical structure as the temperature is raised. Wray and colleagues (Schlichting, I., and J. Wray. 1986. J. Muscle Res. Cell Motil. 7:79; Wray, J., R. S. Goody, and K. Holmes. 1986. Adv. Exp. Med. Biol. 226:49-59) interpreted the transition as reflecting a coupling between nucleotide state and global conformation with M.ATP (disordered) being favored at 0 degrees C and M.ADP.P(i) (ordered) at 20 degrees C. However, hitherto this has been limited to a qualitative correlation and the biochemical state of the myosin heads required to obtain the helical array has not been unequivocally identified. In the present study we have critically tested whether the helical arrangement of the myosin heads requires the M.ADP.P(i) state. X-ray diffraction patterns were recorded from skinned rabbit psoas muscle fiber bundles stretched to non-overlap to avoid complications due to interaction with actin. The effect of temperature on the intensities of the myosin-based layer lines and on the phosphate burst of myosin hydrolyzing ATP in solution were examined under closely matched conditions. The results showed that the fraction of myosin mass in the helix closely followed that of the fraction of myosin in the M.ADP.P(i) state. Similar results were found by using a series of nucleoside triphosphates, including CTP and GTP. In addition, fibers treated by N-phenylmaleimide (Barnett, V. A., A. Ehrlich, and M. Schoenberg. 1992. Biophys. J. 61:358-367) so that the myosin was exclusively in the M.ATP state revealed no helical order. Diffraction patterns from muscle fibers in nucleotide-free and in ADP-containing solutions did not show helical structure. All these confirmed that in the presence of nucleotides, the M.NDP.P(i) state is required for helical order. We also found that the spacing of the third meridional reflection of the thick filament is linked to the helical order. The spacing in the ordered M.NDP.P(i) state is 143.4 A, but in the disordered state, it is 144. 2 A. This may be explained by the different interference functions for the myosin heads and the thick filament backbone.

Adenosine Diphosphate↗
PubMed1999

Decline of sexual function with age in Japanese men compared with American men--results of two community-based studies.

OBJECTIVES: To investigate the self-reported sexual function of Japanese men aged 40 to 79 years in a community-based study and compare the results to a similarly conducted study in Olmsted County, Minnesota. METHODS: Two hundred eighty-nine Japanese and 2115 American men from the community were queried about ability to have erections when stimulated, sexual drive, and satisfaction with sexual activity using a self-administered questionnaire. RESULTS: Both Japanese and American men showed an age-related decline in erectile function, sexual libido, and sexual satisfaction. In particular, 71% of Japanese men aged 70 to 79 years reported having erections only a little of the time or less when sexually stimulated, and 80% perceived sexual drive once per month or less during the past month. Although more Japanese than American men reported erectile dysfunction and decreased libido, there were no striking differences in self-reported sexual satisfaction between the studies. However, cultural and perceptual differences could play a role in these results, despite attempts to ensure linguistic equivalency in the questionnaires. CONCLUSIONS: Although erectile dysfunction and decreased libido were noted by a greater proportion of Japanese than American men, the self-reported degree of satisfaction was comparable between the studies. Perceptions of elderly male sexual function and its impact on health-related quality of life may differ among races, sites, and countries.

Adult↗
PubMed1999

HIV infection associated with drug injecting in the newly independent states, eastern Europe: the social and economic context of epidemics.

AIMS: We review recent trends in HIV associated with injecting drug use (IDU) in the Newly Independent States (NIS) in eastern Europe, including Belarus, Moldova, Russia, Ukraine, and Kazakhstan in central Asia. We aim to draw attention to the social and economic "risk environments" in which rapid HIV spread among IDUs has occurred. METHODS: Findings draw on centrally registered HIV surveillance data, published research studies and assessment reports funded by international development agencies. FINDINGS: Since 1995, there is evidence of rapid HIV spread in Belarus, Kazakhstan, Moldova, Russia and Ukraine, with estimates suggesting between 50% and 90% of new HIV infections among IDUs. At the same time, there have been rapid increases in the incidence of syphilis and declines in health and welfare status, including outbreaks of diphtheria, tuberculosis and cholera. Findings emphasize the potential influence of the social and economic context in creating the "risk environments" conducive to HIV and epidemic spread. Key factors include: rapid diffusions in IDU; population migration and mixing; economic transition and decline; increasing unemployment and impoverishment; the growth of informal economies; modes of drug production, distribution and consumption; declines in public health revenue and infrastructure; and political, ideological and cultural transition. CONCLUSIONS: An understanding of the social and economic contexts mediating HIV spread is a prerequiste to identifying the environmental "pre-conditions" of epidemic outbreaks, and thus also, for predicting and preventing HIV transmission. The "risk environment" may influence the efficacy of individual and community-level HIV prevention and highlights the concomitant urgency for interventions targeting social and environmental change.

Europe, Eastern↗