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Biomedical subjects

J Clarke

Publications and source records attributed to J Clarke.

At least 55 records · Page 3Linked to original sources
PubMed2001

Hepatitis C disease among injection drug users: knowledge, perceived risk and willingness to receive treatment.

We surveyed 306 former injection drug users receiving methadone maintenance treatment in 1997-1998 in Providence, RI regarding, (1) knowledge of hepatitis C transmission; (2) the concordance of self-knowledge of hepatitis C virus (HCV) status versus actual status; (3) perceived risk of cirrhosis; and (4) willingness to receive therapy for hepatitis C. The seroprevalence of HCV was 87%. While 77% of participants knew that HCV could be sexually transmitted, 30% did not know that condoms are protective against transmission. Thirty of 45 persons who reported they were HCV seronegative were actually seropositive; 51 of 62 persons (82%) who reported they had never been HCV tested or did not know their HCV status were serologically HCV-positive. Over half of respondents (53%) would "definitely" or "probably" use interferon therapy for viral hepatitis when informed of the risks and benefits of treatment. We found significant gaps in knowledge about HCV among IDUs. Serologic confirmation of HCV status is important among drug users, as self-report of HCV infection is often unreliable. This population, with its high prevalence of HCV, may be interested in treatments that include interferon.

Antiviral Agents↗
PubMed2001

Regulation of systemic acquired resistance by NPR1 and its partners.

The NPR1 protein of Arabidopsis thaliana has been shown to be an important regulatory component of systemic acquired resistance (SAR). Mutations in the NPR1 gene block the induction of SAR by the signal molecule salicylic acid (SA). NPR1 contains an ankyrin repeats and a BTB domain which are involved in interaction with other protein(s). To further study the function of NPR1 and the regulatory mechanism of SAR, we used both molecular and genetic approaches to identify additional SAR regulatory components. Through a yeast two-hybrid screen we found that NPR1 interacts specifically with bZIP transcription factors. The involvement of bZIP transcription factors in controlling the SA-induced genes had been suggested by a number of promoter studies performed on these genes. It was found that as1 element, which is a binding site for bZIP transcription factors, is essential for SA-induced gene expression. In a genetic screen for suppressors of npr1, we found a mutant, sni1, that restored the responsiveness to SAR induction in npr1. The genetic characteristics of the sni1 mutant and the sequence of SNI1 suggest that the wild-type SNI1 protein is a negative regulator of SAR. We believe that SAR is controlled by both positive regulators and negative regulators.

Arabidopsis↗
PubMed2001

Timing and localization of movement-related spectral changes in the human peri-Rolandic cortex: intracranial recordings.

Event-related spectral power (ERSP) was measured from intracranial EEG and used to characterize the time-course and localization of the Rolandic mu rhythms in 12 patients during the delayed recognition of words or faces (DR) and the discrimination of simple lateralized visual targets (LVD). On each trial, the subject decided whether to make manual response (Go) or not (NoGo). ERSP increased on both Go and NoGo trials in peri-Rolandic regions of all subjects with a peak latency of approximately 330-ms poststimulus and duration of 260 ms during the DR task. The peak of this ERSP increase preceded movement by approximately 300 ms. All subjects produced a subsequent movement specific ERSP decrease of peri-Rolandic mu rhythms (starting approximately 90 ms before the average reaction time) with an peak latency of approximately 800 ms and duration of approximately 520 ms. The LVD task produced bilateral movement-selective readiness potentials and reproduced the movement-specific late ERSP decreases seen in the DR task (strongest from 7-24 Hz). Furthermore, the LVD task demonstrated that the late movement-related ERSP decrease is larger for the contralateral hand. However, the LVD task did not consistently reproduce the early ERSP increase seen in the DR task. Movement-related ERSP decreases were widespread, occurring in pre- and post-Rolandic as well as primary-motor, supplemental motor, and cingulate cortical regions. Other cortical areas including frontal, temporal, and occipital regions did not show movement-related ERSP changes. Peri-Rolandic ERSP decreases in mu rhythms correlate with the generation of a motor command. The early increases in mu may reflect a transient state of motor inhibition just prior to motor execution.

Brain Mapping↗
PubMed2001

Investigation of varicella-zoster virus variation by heteroduplex mobility assay.

Heteroduplex mobility assays of 37 regions were performed on ten UK isolates of varicella zoster virus, four from cases of zoster, and six from cases of chickenpox. The variation between isolates was found to be 0.061%, which is at least five times lower than any other member of the human herpesvirus family. Fifteen of the 37 regions tested had 29 single nucleotide polymorphisms, and over half the polymorphisms were located in four gene fragments. Of the 29 SNPs, eleven were non-synonymous and these were clustered in six genes. Isolates from a child and her mother to whom she had transmitted the virus, were identical at every locus tested. All other viruses could be distinguished by a combination of SNPs and length polymorphisms of the repeat regions R1, R2 and R5.

Chickenpox↗
PubMed2001

The chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects.

RATIONALE: Extracts of Bacopa monniera have been reported to exert cognitive enhancing effects in animals. However, the effects on human cognition are inconclusive. OBJECTIVE: The current study examined the chronic effects of an extract of B. monniera (Keenmind) on cognitive function in healthy human subjects. METHODS: The study was a double-blind placebo-controlled independent-group design in which subjects were randomly allocated to one of two treatment conditions, B. monniera (300 mg) or placebo. Neuropsychological testing was conducted pre-(baseline) and at 5 and 12 weeks post drug administration. RESULTS: B. monniera significantly improved speed of visual information processing measured by the IT task, learning rate and memory consolidation measured by the AVLT (P<0.05), and state anxiety (P<0.001) compared to placebo, with maximal effects evident after 12 weeks. CONCLUSIONS: These findings suggest that B. monniera may improve higher order cognitive processes that are critically dependent on the input of information from our environment such as learning and memory.

Adolescent↗
PubMed2001

Cardiovascular responses during arm exercise and orthostatic challenge in individuals with paraplegia.

In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5-T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (VO2), heart rate (fc), stroke volume (SV) and cardiac output (Qc) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE + LBNP), and, in PARA only, (3) ACE + LBNP with ES (ACE + LBNP+ ES). In both PARA and AB, ACE + LBNP decreased SV (by 13-18% and 20-23%, respectively) and increased fc (by 13-15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group x trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change VO2 or Qc. The smaller reduction in SV from ACE to ACE + LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE + LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.

Adult↗
PubMed2001

Can non-mechanical proteins withstand force? Stretching barnase by atomic force microscopy and molecular dynamics simulation.

Atomic force microscopy (AFM) experiments have provided intriguing insights into the mechanical unfolding of proteins such as titin I27 from muscle, but will the same be possible for proteins that are not physiologically required to resist force? We report the results of AFM experiments on the forced unfolding of barnase in a chimeric construct with I27. Both modules are independently folded and stable in this construct and have the same thermodynamic and kinetic properties as the isolated proteins. I27 can be identified in the AFM traces based on its previous characterization, and distinct, irregular low-force peaks are observed for barnase. Molecular dynamics simulations of barnase unfolding also show that it unfolds at lower forces than proteins with mechanical function. The unfolding pathway involves the unraveling of the protein from the termini, with much more native-like secondary and tertiary structure being retained in the transition state than is observed in simulations of thermal unfolding or experimentally, using chemical denaturant. Our results suggest that proteins that are not selected for tensile strength may not resist force in the same way as those that are, and that proteins with similar unfolding rates in solution need not have comparable unfolding properties under force.

Animals↗
PubMed2001

Neuropsychological changes after 30-day Ginkgo biloba administration in healthy participants.

Ginkgo biloba extract (EGb) from the world's oldest living tree has been reputed to ameliorate cognitive decline in the elderly and slow cognitive deterioration in patients with dementia of the Alzheimer's type. EGb remains as one of the most popular plant extracts to alleviate symptoms associated with a range of cognitive disorders such as Alzheimer's disease, vascular dementia and age-related amnesic conditions. EGb is known to contain a range of chemically active components that have antagonistic effects on platelet-activating factor, free-radical scavenging activity and direct effects on the cholinergic neurotransmitter system. Recently there has been much speculation, that EGb may act as a 'smart drug' or nootropic agent in the healthy young to improve intelligence. We conducted a 30-d randomized, double-blind, placebo-controlled clinical trial in which 61 participants were administered a battery of validated neuropsychological tests before and after treatment. Statistical analysis indicated significant improvements in speed of information processing working memory and executive processing attributable to the EGb.

Adult↗
PubMed2001

Analysis of a clinical sign in traditional Chinese medicine using Doppler ultrasound.

Using Doppler ultrasound, a study was done on the characteristics of the radial pulse at the wrist in pregnant and non-pregnant women in order to test the hypothesis that the traditional Chinese medicine 'smooth pulse' of pregnancy has a physiological basis. Comparison of pulse characteristics in a small series of subjects strongly supports this hypothesis.

Adult↗
PubMed2001

Chiropractors and return-to-work: the experiences of three Canadian focus groups.

OBJECTIVES: To explore the views of chiropractors about timely return-to-work in treating patients with musculoskeletal injuries, to identify the approaches used by chiropractors when treating injured workers with musculoskeletal disorders, and to learn about chiropractors' perspectives on the barriers and facilitators of successful return-to-work. DESIGN: Qualitative study of 3 focus groups of chiropractors. METHODS: Focus groups of 8 to 11 chiropractors were conducted in 3 large Canadian cities. The selected participants were experienced in treating patients with occupational musculoskeletal injuries. Standard questions were used to collect data. The data from each focus group were coded and analyzed separately and then considered in relation to each other. RESULTS: The participants indicated that timely return-to-work depends on patients' characteristics, severity of injury, clinical progress, the availability of work accommodation, and clinical judgment. The chiropractors commented that their treatment of injured workers rests on their strength in diagnosis and treatment and on providing patient-centered care. Positive human relations within workplaces and the ability to accommodate the work of an injured worker were described as important in return-to-work programs. The participants believed that a bias against chiropractic is present within the medical profession and workers' compensation boards. They viewed this bias as an important barrier when assisting their patients to successfully return to work. CONCLUSION: The broad approaches described by the participating chiropractors to return injured workers to work are consistent with those proposed in evidence-based practice guidelines. Better communication among chiropractors, medical doctors, and workers' compensation boards would likely decrease interprofessional tensions and improve the recovery of workers with musculoskeletal injuries.

Adult↗
PubMed2001

Evolution of depressive symptoms in human immunodeficiency virus-infected patients entering primary care.

Our purpose was to examine among HIV-infected patients a) characteristics associated with depressive symptoms at initial primary care presentation and b) factors associated with improvement in depressive symptoms. We interviewed HIV-infected patients at initial presentation and reassessed them 6 months later. At baseline and follow-up, we collected data on depressive symptoms (CES-D) and other characteristics. Using multiple linear regression, we examined associations between CES-D score and baseline variables. We used multiple logistic regression to examine factors associated with improvement in depressive symptoms. Seventy-one percent of the baseline sample (N = 203) scored above the threshold considered indicative of depression. At 6 months, 36% of the subjects who were followed improved in depressive symptoms. Higher baseline CES-D scores, improvements in HIV-related symptoms, and joining a support group were associated with improvement. Depressive symptoms in this urban HIV-infected population were highly prevalent. It is essential to screen, identify, and treat depression among patients entering care for HIV disease. Encouragement in joining support groups is a reasonable component of a strategy for addressing this common condition.

Adult↗
PubMed2001

Organizing the approach to musculoskeletal misuse syndrome.

Musculoskeletal misuse syndromes are secondary to misuse of specific tendons, ligaments, or other soft tissues. Despite patient education interventions to prevent acute musculoskeletal injury, these injuries still occur. A well-organized approach to musculoskeletal complaints can reduce the risk of missed diagnoses and ensure appropriate care. This article reviews history and physical examination findings indicative of a misuse etiology and provides clinicians with a discussion of available diagnostic tests and therapies.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2001

An analysis of how The Irish Times portrayed Irish nursing during the 1999 strike.

The aim of this article is to explore the images of nursing that were presented in the media during the recent industrial action by nurses and midwives in the Republic of Ireland. Although both nurses and midwives took industrial strike action, the strike was referred to as 'the nurses' strike' and both nurses and midwives were generally referred to by the generic term 'nurses'. Data were gathered from the printed news media of The Irish Times over a period of one month--4 October to 4 November 1999--which included the nine days of the strike. Although we limited the source of our data to just one newspaper, the findings do provide an image of how nurses and nursing care are viewed by both health professionals and the public. This image appeared to give a higher value to masculine cultural codes and the performance of technical skills, whereas acts associated with feminine cultural codes of caring were considered of lower value.

Empathy↗
PubMed2001

An association of disseminated Mycoplasma fermentans in HIV-1 positive patients with non-Hodgkin's lymphoma.

We examined the relationship between the haematogenous dissemination of Mycoplasma fermentans and non-Hodgkin's lymphoma (NHL) in 265 HIV-1 positive patients. A polymerase chain reaction (PCR) assay was used to detect M. fermentans in peripheral blood mononuclear cells (PBMCs) from 50 patients enrolled consecutively from an HIV outpatient clinic in 1991 (cohort 1), 56 patients with lower respiratory tract infection who underwent bronchoscopy in 1992 (cohort 2), and 159 patients who were enrolled into a natural history cohort study in 1994 (cohort 3). The incidence of NHL among the patients was determined in 1998. The PBMCs of 29 patients (10.9%) were positive for M. fermentans (8 in cohort 1, 13 in cohort 2 and 8 in cohort 3) and 11 patients (4.2%) developed NHL which was confirmed histologically (3 in cohort 1, 4 in cohort 2 and 4 in cohort 3). We found a statistically significant association between the presence of M. fermentans and the development of NHL in the combined cohort (risk ratio [RR]=6.78 [95% confidence interval (CI) 2.21--20.84], P=0.003 Fisher's exact test [FET]). This association remained significant even after adjustment in a multivariate analysis for CD4 cell count and HIV disease status at the time of M. fermentans testing (RR=7.97 [95% CI=2.16--29.47], P=0.002).

AIDS-Related Opportunistic Infections↗
PubMed2001

Over-the-counter advice for genital problems: the role of the community pharmacist.

This year, in the UK, levonorgestrel was approved for sale in pharmacies for emergency contraception. This study assessed, using a postal questionnaire, the ability of community pharmacists to provide advice relating to sexual health, their comfort and training in this area, and their knowledge of local genitourinary medicine (GUM) services. Fifty-four per cent of pharmacists responded. Most (79%) did not know where their nearest GUM department was; only 21% had ever advised a patient to attend a GUM clinic. Twenty-nine per cent said they were not able to broach the possibility of a sexually transmitted infection (STI) with a patient of both sexes. Forty-four per cent had received training related to post-coital contraception. Greater liaison between GUM departments and community pharmacists is suggested as a way of increasing the proportion of patients presenting to a pharmacist who are referred appropriately to a GUM clinic.

Attitude of Health Personnel↗
PubMed2001

A multi-district audit against national guidelines for the management of uncomplicated genital Chlamydia trachomatis infection.

A regional audit group in genitourinary medicine (GUM) developed a method to assess their practice using peripatetic audit workers. An audit using 2 audit proformas recorded information relating to an agreed selection of standards contained within the national guidelines for the management of uncomplicated genital chlamydial infection. An audit worker (ADP) reviewed patient records of a sample of cases. Nine GUM clinics throughout the Yorkshire region participated in the audit; 489 cases out of a total annual workload of 2358 cases positively diagnosed as uncomplicated chlamydial infection were reviewed. Variations in compliance with the standards for confirmation of test results and the time from diagnosis to treatment were seen. Recording of discussions, advice and contact tracing activity were limited or separated from the main patient record, making assessment of practice difficult. Post-audit meetings of the group led to action on these areas and commitment to re-audit with the same standards and methods.

Ambulatory Care Facilities↗