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Biomedical subjects

R Ballard

Publications and source records attributed to R Ballard.

At least 19 recordsLinked to original sources
PubMed2006

Prospective, multi-centre clinic-based evaluation of four rapid diagnostic tests for syphilis.

OBJECTIVES: To evaluate prospectively four rapid, point-of-care serological tests for syphilis in prenatal or high risk populations in four countries. METHODS: Tests were performed on consecutive clinic attenders, using whole blood in the clinic, and whole blood and serum in the laboratory. The sensitivity and specificity of each test was evaluated, using a standard treponemal test (Treponema pallidum haemagglutination assay (TPHA) or fluorescent treponemal antibody, absorbed (FTA-ABS) as gold standard. Non-treponemal tests (rapid plasma reagin (RPR) or venereal diseases research laboratory (VDRL) tests) were also performed on all subjects at three sites. RESULTS: The specificity of each rapid test was >95% at each site. Sensitivities varied from 64-100% and, in most cases, were lower when whole blood was used rather than serum. CONCLUSIONS: Rapid serological tests for syphilis are an acceptable alternative to conventional laboratory tests. Since they do not require equipment or electricity, they could increase coverage of syphilis screening, and enable treatment to be given at the first clinic visit.

Adolescent↗
PubMed2001

HIV infection among youth in a South African mining town is associated with herpes simplex virus-2 seropositivity and sexual behaviour.

OBJECTIVES: To determine the seroprevalence of HIV and herpes simplex virus-2 (HSV-2) by age and gender among young people aged 14--24 years in a South African town and to identify risk factors for HIV infection. DESIGN: A community-based, cross-sectional study was conducted on a random sample of men (n = 723) and women (n = 784) living in a township in the Carletonville district of South Africa. METHODS: Potential demographic and behavioural risk factors associated with HIV were recorded by questionnaire and biological tests were performed on serum and urine. Data analysis was performed using multivariate logistic regression. RESULTS: Among men and women the prevalence of HIV infection was 9.4 and 34.4%, respectively, and of positive HSV-2 serology was 17.0 and 53.3%, respectively. Among 24-year-old women the prevalence of HIV was 66.7% [95% confidence interval (CI), 54.6--77.3%]. HSV-2 seropositivity was a strong independent risk factor for HIV infection with odds ratios of 5.3 (95% CI, 2.7--10.3) for men and 8.4 (95% CI, 4.9--14.2) for women. There was no independent effect of age at first sex or serological markers of other sexually transmitted infections on HIV infection. CONCLUSIONS: HIV infection among young women increases rapidly after the onset of sexual activity and reaches extremely high levels by 24 years of age. These findings suggest that rates of HIV transmission from men to women are high and that HSV-2 plays a major role in the spread of HIV in this population.

Adolescent↗
PubMed2001

No mission<-->no margin: it's that simple.

The authors describe their experience in developing a strategy-focused organization using the balanced scorecard methodology. They achieved this at Duke Children's Hospital by aligning the clinicians and administrators around a single integrated platform that linked improving business processes with achieving quality clinical outcomes. By organizing in this manner, they reduced cost by dollars 30 million and increased net margin by dollars 15 million while improving outcomes and staff satisfaction. This article describes a methodology to achieve strategic control of the organization, increase the knowledge of key stakeholders, and transform the organization to optimize the organization's performance.

Benchmarking↗
PubMed2000

Evidence of declining STD prevalence in a South African mining community following a core-group intervention.

OBJECTIVES: To reduce the prevalence of curable sexually transmitted diseases (STDs) in a South African mining community through provision of STD treatment services, including periodic presumptive treatment and prevention education to a core group of high-risk women living in areas around the mines. METHODS: Women at high risk for STDs attended a mobile clinic monthly for examination and counseling, and were treated presumptively for bacterial STDs with a directly observed 1-g dose of azithromycin. Gonococcal and chlamydial infection rates were measured by urine ligase chain reaction, and genital ulcers were assessed by clinical examination. Changes in STD prevalence among local miners were assessed through comparison of prevalence in two cross-sectional samples of miners taken 9 months apart, and through routine disease surveillance at mine health facilities. RESULTS: During the first 9 months of the intervention, 407 women used the services. Baseline prevalence of Neisseria gonorrhoeae and/or Chlamydia trachomatis in women was 24.9%; 9.7% of these women had clinical evidence of genital ulcer disease (GUD). The proportion of women with incident gonococcal or chlamydial infections at the first monthly return visit (69% follow-up rate) was 12.3%, and genital ulcers were found in 4.4% of these women. In the miner population, the prevalence of N gonorrhoeae and/or C trachomatis was 10.9% at baseline and 6.2% at the 9-month follow-up examination (P<0.001). The prevalence of GUD by clinical examination was 5.8% at baseline and 1.3% at follow-up examination (P< 0.001). Rates of symptomatic STDs seen at mine health facilities decreased among miners in the intervention area compared with miners living farther from the site and with less exposure to the project. DISCUSSION: Provision of STD treatment services to a core group of high-risk women may significantly reduce their burden of disease, and may contribute to a reduction in community STD prevalence. In the absence of sensitive and affordable screening tests for STDs in women, periodic presumptive treatment coupled with prevention education is a feasible approach to providing STD services in this population.

Adult↗
PubMed2000

Homeopathy. An overview.

BACKGROUND: Homeopathy was founded 200 years ago by Dr Samuel Hahnemann. Although it has been seen by some as quackery, it has found a level of acceptance in the community in general. OBJECTIVE: This article reviews the principles underlying the practice of homeopathy and reviews some of the studies which attempt to understand its validity. DISCUSSION: The theoretical principles of homeopathy derive from clinical observation. There is some research demonstrating efficacy; however, the underlying basis of the discipline has yet to be explained. Much research still needs to be done in order to elucidate its mechanisms of action and to determine its specific place in clinical practice.

Europe↗
PubMed1998

A multidisciplinary approach to hemodialysis access: prospective evaluation.

Dialysis access procedures and complications represent a major cause of morbidity, hospitalization and cost for chronic dialysis patients. To improve outcomes and reduce the cost of hemodialysis access procedures we developed a multidisciplinary approach, involving nephrologists, access surgeons, and radiologists. A full-time dialysis access coordinator scheduled all access procedures with the surgeons and radiologists, and tracked outcomes. A computerized database was developed for prospective documentation of procedures and complications. Confidential, detailed analyses and recommendations for improvements were provided periodically to the surgeons and radiologists. The major changes arising from the multidisciplinary approach were as follows: (1) The approach to clotted grafts evolved from an inpatient surgical procedure to an outpatient radiologic procedure. The immediate technical success rate of graft declots increased from 48% to 69%. (2) Elective placement of arteriovenous (A-V) grafts evolved from a three-day inpatient hospitalization to a largely outpatient procedure. The proportion of A-V grafts placed as same day surgery or outpatient surgery increased from 16% to 81%. (3) Surgical complications of new A-V graft surgery decreased from 25% to 11%. (4) Aggressive detection and correction of graft stenosis decreased the incidence of graft thrombosis by 60%, from 0.70 to 0.28 events per patient-year. (5) The proportion of native A-V fistula construction in new dialysis patients increased from 33% to 69%. In conclusion, an integrated multidisciplinary approach markedly reduced surgical complications of access surgery and decreased access failures. These improvements occurred despite a marked decrease in hospitalization for access procedures, with a substantial cost saving.

Aged↗
PubMed1998

The rrs (16S)-rrl (23S) ribosomal intergenic spacer region as a target for the detection of Haemophilus ducreyi by a heminested-PCR assay.

The intergenic spacer region between the rrs and rrl ribosomal RNA genes of Haemophilus ducreyi was analysed and the DNA sequence was used for the selection of specific PCR primers. A highly sensitive and specific heminested-PCR assay for the identification of H. ducreyi was developed. The assay showed a sensitivity of 96% on genital ulcer specimens from patients with clinically diagnosed chancroid, compared with a sensitivity of 56% for culture methods. These results indicate that this PCR assay has the potential to become an accurate and easy reference method for the detection of H. ducreyi.

Base Sequence↗
PubMed1998

Potential Alu function: regulation of the activity of double-stranded RNA-activated kinase PKR.

Cell stress, viral infection, and translational inhibition increase the abundance of human Alu RNA, suggesting that the level of these transcripts is sensitive to the translational state of the cell. To determine whether Alu RNA functions in translational homeostasis, we investigated its role in the regulation of double-stranded RNA-activated kinase PKR. We found that overexpression of Alu RNA by cotransient transfection increased the expression of a reporter construct, which is consistent with an inhibitory effect on PKR. Alu RNA formed stable, discrete complexes with PKR in vitro, bound PKR in vivo, and antagonized PKR activation both in vitro and in vivo. Alu RNAs produced by either overexpression or exposure of cells to heat shock bound PKR, whereas transiently overexpressed Alu RNA antagonized virus-induced activation of PKR in vivo. Cycloheximide treatment of cells decreased PKR activity, coincident with an increase in Alu RNA. These observations suggest that the increased levels of Alu RNAs caused by cellular exposure to different stresses regulate protein synthesis by antagonizing PKR activation. This provides a functional role for mammalian short interspersed elements, prototypical junk DNA.

Cell Line↗
PubMed1997

On-site HIV testing in resource-poor settings: is one rapid test enough?

OBJECTIVE: To determine the feasibility, accuracy and cost-effectiveness of a rapid, on-site, HIV testing strategy in a rural hospital, and to assess its impact on test turnaround time and the proportion of patients post-test counselled. DESIGN: Prospective comparison of two testing strategies [double rapid test on-site versus central enzyme-linked immunosorbent assay (ELISA)-based testing], and an economic evaluation. SETTING: Hlabisa Hospital, a rural South African district hospital. PATIENTS: A total of 454 consecutive adult inpatients requiring and consenting to HIV testing as part of their clinical management. MAIN OUTCOME MEASURES: Concordance between rapid tests, and between the rapid and ELISA strategies, test turnaround time, proportion of patients post-test counselled, and cost-effectiveness. RESULTS: HIV seroprevalence was 49.6%. Both rapid tests were concordant in all patients [one-sided 95% confidence interval (CI) of probability, 99.3-100]. The rapid strategy was 100% sensitive (95% CI, 97.9-100) and 99.6% specific (95% CI, 97.2-100) compared with the ELISA strategy. The mean interval between ordering a test and post-test counselling fell from 21 days prior to the introduction of the rapid test strategy to 4.6 days after its introduction (P < 0.00001). The proportion of patients post-test counselled increased to 96% from 17% after the introduction of the rapid test strategy (P < 0.00001). By using a double rapid test strategy the cost per patient post-test counselled was almost halved to US$ 11. Accuracy of the rapid strategy was not substantially increased by performing two tests. CONCLUSION: In high prevalence, resource-poor settings, rapid, on-site HIV testing is feasible, accurate and highly cost-effective, substantially increasing the number of patients post-test counselled. A single rapid test may be sufficient.

AIDS Serodiagnosis↗
PubMed1996

A three year outcome evaluation of a theory based drink driving education program.

This study reports on the impact of a "drink driving education program" taught to grade ten high school students. The program which involves twelve lessons uses strategies based on the Ajzen and Madden theory of planned behavior. Students were trained to use alternatives to drink driving and passenger behaviors. One thousand seven hundred and seventy-four students who had been taught the program in randomly assigned control and intervention schools were followed up three years later. There had been a major reduction in drink driving behaviors in both intervention and control students. In addition to this cohort change there was a trend toward reduced drink driving in the intervention group and a significant reduction in passenger behavior in this group. Readiness to use alternatives suggested that the major impact of the program was on students who were experimenting with the behavior at the time the program was taught. The program seems to have optimized concurrent social attitude and behavior change.

Adolescent↗
PubMed1995

Intramuscular pressure and torque during isometric, concentric and eccentric muscular activity.

Intramuscular pressures, electromyography (EMG) and torque generation during isometric, concentric and eccentric maximal isokinetic muscle activity were recorded in 10 healthy volunteers. Pressure and EMG activity were continuously and simultaneously measured side by side in the tibialis anterior and soleus muscles. Ankle joint torque and position were monitored continuously by an isokinetic dynamometer during plantar flexion and dorsiflexion of the foot. The increased force generation during eccentric muscular activity, compared with other muscular activity, was not accompanied by higher intramuscular pressure. Thus, this study demonstrated that eccentric muscular activity generated higher torque values for each increment of intramuscular pressure. Intramuscular pressures during antagonistic co-activation were significantly higher in the tibilis anterior muscle (42-46% of maximal agonistic activity) compared with the soleus muscle (12-29% of maximal agonistic activity) and was largely due to active recruitment of muscle fibers. In summary, eccentric muscular activity creates higher torque values with no additional increase of the intramuscular pressure compared with concentric and isometric muscular activity.

Adult↗
PubMed1994

The Chédiak-Higashi syndrome: CT and MR findings.

Chédiak-Higashi syndrome (CHS) is a rare autosomal recessive disorder postulated to result from lack of regulation of fusion of the primary lysosomes. In this report we present the MR and CT features of the brain in a patient with known CHS. These findings include diffuse atrophy of the brain with diffuse periventricular decreased density identified with CT, as well as increased signal on the T2-weighted images and lack of enhancement on the T1-weighted images in the periventricular and corona radiata regions.

Atrophy↗
PubMed1993

Antimicrobial susceptibilities and serotyping of Neisseria gonorrhoeae in southern Africa: influence of geographical source of infection.

One hundred and ninety-two strains of Neisseria gonorrhoeae isolated from migrant mine-workers were tested for their susceptibility to antibiotics, auxotyped and serotyped. Of the total, 93 (48%) were acquired locally and 64 (33%) from different geographical locations. Plasmid-mediated resistance to penicillin was found in 28 (14.6%) strains and was associated predominantly with the presence of 5.0 kb penicillinase encoding plasmid (18/28, 64%). Chromosomal resistance to penicillin (MIC > or = 1 mg/l) was detected in 14 (7.3%) strains. Resistance to tetracycline was chromosomally and not plasmid-mediated. Antibiotic resistance was encountered most commonly among strains acquired in Natal. The overall gonococcal population was sensitive to ceftriaxone, ciprofloxacin, spectinomycin and azithromycin. Nine auxotype/serovar (A/S) classes were encountered among penicillinase-producing N. gonorrhoeae (PPNG) compared to 24 A/S classes among non-PPNG strains. The most common A/S class was NR/IA-6 which accounted for 38% of PPNG and 15% of non-PPNG.

Africa, Southern↗
PubMed1993

Progressive massive fibrosis associated with idiopathic pulmonary hemosiderosis.

Progressive massive fibrosis is a recognized complication of pneumoconiosis secondary to pulmonary fibrosis, with retraction forming conglomerate masses symmetrically in the upper lobes. Idiopathic pulmonary hemosiderosis is known to cause pulmonary fibrosis secondary to recurrent alveolar hemorrhage with deposition of hemosiderin in the interstitium. We present a case in which progressive massive fibrosis developed in a patient with long-standing idiopathic pulmonary hemosiderosis.

Female↗