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Biomedical subjects

A Ronald

Publications and source records attributed to A Ronald.

At least 19 recordsLinked to original sources
PubMed2006

Rapid tests for sexually transmitted infections (STIs): the way forward.

In the developing world, laboratory services for sexually transmitted infections (STIs) are either not available, or where limited services are available, patients may not be able to pay for or physically access those services. Despite the existence of national policy for antenatal screening to prevent congenital syphilis and substantial evidence that antenatal screening is cost-effective, implementation of syphilis screening programmes remains unacceptably low because of lack of screening tools that can be used in primary health care settings. The World Health Organization Sexually Transmitted Diseases Diagnostics Initiative (SDI) has developed the ASSURED criteria as a benchmark to decide if tests address disease control needs: Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment-free and Deliverable to end-users. Rapid syphilis tests that can be used with whole blood approach the ASSURED criteria and can now be deployed in areas where no previous screening has been possible. Although rapid tests for chlamydia and gonorrhoea lack sensitivity, more tests are in development. The way forward for STI diagnostics requires a continuing quest for ASSURED tests, the development of a road map for test introduction, sustainable programmes for quality assurance, and the creation of a robust infrastructure linked to HIV prevention that ensures sustainability of STI control efforts that includes viral STIs.

Chlamydia Infections↗
PubMed2006

Excellence in sexually transmitted infection (STI) diagnostics: recognition of past successes and strategies for the future.

Diagnostic advances do not generally receive the recognition given to prevention and treatment contributions, for the control and management of infectious diseases including sexually transmitted infections (STIs). In order to identify seminal diagnostic contributions over a half century (1950-2000), the Editorial Board of the WHO Sexually Transmitted Diseases Diagnostics Initiative (SDI) Publication Review or "electronic journal club" were asked to nominate their choices of peer-reviewed publications for special recognition. From 43 nominations, 13 were voted by a panel of 25 "experts" as having made the most significant contributions. The 1964 article by Thayer and Martin, which identified a selective media for gonococcal culture, was chosen unanimously by all panel members and is identified as the classic STI diagnostic article for this era.

Forecasting↗
PubMed2006

Antiretroviral therapy improves cognitive impairment in HIV+ individuals in sub-Saharan Africa.

BACKGROUND: Highly active antiretroviral therapy (HAART) can improve cognitive performance in some patients with HIV-associated cognitive impairment in the United States. The effect of HAART on HIV dementia in sub-Saharan Africa is largely unknown. OBJECTIVE: To evaluate neuropsychological test and functional performance in HIV+ individuals after 3 and 6 months of HAART in Uganda. METHODS: Twenty-three HIV+ individuals receiving HAART also received a detailed clinical history, neuropsychological testing, and a functional assessment. Follow-up evaluations were performed at 3 and 6 months after baseline. Longitudinal changes in the HIV dementia stage, the mean Z score for each neuropsychological test, and the Karnofsky Functional Performance Scale were evaluated at 3 and 6 months. RESULTS: The mean (SD) CD4 cell count improved from 71 (15) at baseline to 161 (30) at 3 months (p = 0.005) and 222 (46) at 6 months (p < 0.001). Improvements were found in the Memorial Sloan Kettering HIV dementia stage and in tests of verbal memory, psychomotor speed, and executive functioning after 3 and 6 months of HAART (p < 0.001 at 6 months for each neuropsychological test). There was also improvement in the Karnofsky Functional Performance Scale at both 3 and 6 months after the initiation of HAART (p < 0.001). CONCLUSION: Highly active antiretroviral therapy (HAART) can be associated with improvement in neurocognitive and functional performance in HIV+ individuals in sub-Saharan Africa. These results suggest that HAART, if available in areas with limited resources in sub-Saharan Africa, should be provided for patients with HIV-associated cognitive impairment.

Adult↗
PubMed2006

Development of immunosensor based on OWLS technique for determining Aflatoxin B1 and Ochratoxin A.

Mycotoxins are toxic secondary metabolites produced by a number of different fungi, and can be present in a wide range of food and feed commodities including cereal grains, oil seeds, dried fruits, apple juice, wine and meat products from animals fed contaminated meal. Many mycotoxins are highly resistant, and survive food processing, and therefore enter the food chain and provide a threat to human health. The optical waveguide lightmode spectroscopy (OWLS) technique has been applied to the detection of Aflatoxin and Ochratoxin in both competitive and in direct immunoassays. After immobilizing the antibody or antigen conjugate for the direct or indirect measurement, respectively, the sensor chip was used in flow-injection analyser (FIA) system. When using non-competitive method, sensor responses were obtained first only at analyte concentrations of 5-10 ng ml(-1). In both cases, the responses were very unstable. For competitive sensor investigation with the sensitized chip first the optimal dilution rate of monoclonal antibodies was determined, for the measurement of Ochratoxin A and Aflatoxin B1 the monoclonal antibody stock solution was diluted to 1 microg ml(-1) and to a 1:400 dilution, respectively. During the competitive measurement standard solutions were mixed with monoclonal antibodies at the appropriate concentration, the mixture was incubated for 1 min and injected into the OWLS system. The sensitive detection range of the competitive detection method was between 0.5 and 10 ng ml(-1) in both cases. After the establishment of the indirect method, barley and wheat flour samples were measured, and the results were in good correlation by those measured by enzyme linked immuno-sorbent assay (ELISA). Regression coefficient between the two methods for Ochratoxin and Aflatoxin was determined as 0.96 and 0.89, respectively.

Aflatoxin B1↗
PubMed2005

Human immunodeficiency virus neurological complications: an overview of the Ugandan experience.

Sub-Saharan Africa, which has about 12% of the global population, is home to almost 70% of individuals infected with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). A recent survey by the Ugandan Ministry of Health has found the HIV prevalence rate to be approximately 7% in sexually active adults. The predominant HIV subtypes present in Uganda are A and D. Health care resources are well planned but often lack human and fiscal resources. Uganda has adopted the World Health Organization (WHO) "3 by 5" global strategy for the introduction of antiretroviral therapy and has surpassed the target. Neurological complications of the HIV virus are common and often have devastating consequences. A recent study in Kampala found the rate of HIV dementia and peripheral neuropathy at 31% and 47%, respectively. Further studies are urgently required to determine the natural history and treatment outcomes of both these common HIV complications.

AIDS-Related Opportunistic Infections↗
PubMed2005

Methylthioninium chloride: pharmacology and clinical applications with special emphasis on nitric oxide mediated vasodilatory shock during cardiopulmonary bypass.

Vasodilatory shock after cardiopulmonary bypass is a common complication requiring treatment with high doses of inotropes and prolonged stays in the intensive care unit. The vasodilatory shock is initiated by an inflammatory response to the extracorporeal circuit. The inflammatory response results in endothelial synthesis and release of nitric oxide resembling the clinical features observed in vasodilatory shock caused by septicaemia. During vasodilatory shock, the inhibition of nitric oxide synthase and the nitric oxide/cyclic guanylyl monophosphate pathway is an attractive adjunct to therapy with traditional inotropes. Methylthioninium chloride inhibits nitric oxide/cyclic guanylyl monophosphate mediated vasodilation and can successfully be used as a supplement in the treatment of vasodilatory shock associated with cardiopulmonary bypass. The application of methylthioninium chloride in septicaemia has not produced comparable positive clinical results.

Adult↗
PubMed2001

Urinary tract infections in adults with diabetes.

Urinary tract (UTI) is a major disease burden for many patients with diabetes. Asymptomatic bacteriuria is several-fold more common among women and acute plyelonephritis is five to ten times more common in both sexes. The complications of pyelonephritis are also more common in patients with diabetes. These complications include acute papillary necrosis, emphysematous pyelonephritis, and bacteremia with metastatic localization to other sites. The management of urinary infection in patients with diabetes is essentially the same as patients without diabetes. Most infections should be managed as uncomplicated except when they occur in a milieu with obstruction or other factors that merit a diagnosis of complicated UTI. Strategies to prevent these infections and reduce morbidity should be a priority for research.

Adult↗
PubMed2001

Infectious diseases on the 21st century doorstep.

Accelerating change can be expected to occur in the fields of Clinical Microbiology and Infectious Diseases. New pathogens, new diseases, new technologies, new vaccines and new treatment modalities will descend on us with increasing frequency in the decade ahead. In order to cope with and even appreciate change, we need to increase our commitment to training, recruiting and retaining health professionals in these disciplines, enhance our research programs, and remain enthusiastic about the benefits offered by skilled, knowledgeable practitioners to our patients. Infectious disease deaths have been increasing during the '90's in most societies. We must reverse this!

Communicable Diseases↗
PubMed2001

Infectious diseases: career preparation.

The human resources for the discipline of Infectious Diseases are inadequate in many countries. There is no global definition of "Infectious Diseases" physicians and cover competency. Preparation for a career in this speciality varies greatly. In large populations in Asia and Africa, few individuals exist who have been trained to be Infectious Disease Clinicians. There is a great need by national and international societies to embrace this speciality and address the global deficiencies in this discipline by directing funding agencies as well as training institutions to redirect resources to strengthen the capacity of health professionals to deal with infectious diseases adequately throughout the world.

Africa↗
PubMed1999

The quinolones and renal infection.

The fluoroquinolones are excellent drugs for the treatment of most patients with renal infection. Ciprofloxacin has proved its value in good clinical trials for uncomplicated acute pyelonephritis and has been used widely for complicated urinary tract infections with presumed renal infection.

4-Quinolones↗
PubMed1998

The evolution of immunoassay technology.

Since they were first utilized, immunoassays have witnessed phenomenal growth in the range and scope of their applications. A vast array of different labels and assay strategies has been developed to meet the requirements of sensitivity, accuracy and convenience. The development of increasingly sensitive labels and detection equipment has seen a drastic improvement in the sensitivity of immunoassay systems, allowing an ever-increasing range of analytes to be measured accurately. At the same time, simple to use, inexpensive assay systems have been developed with the necessary reliability, accuracy and sensitivity to bring immunoassay technology to much more diverse areas such as home testing, near-patient monitoring, and large screening programmes in developing countries. Recent developments in molecular biology techniques have made possible the production of fusion antibody conjugates, which can lead to further improvements in sensitivity and cost of reagents, as well as possibly revolutionizing the production of monoclonal antibodies. However, dissatisfaction with various aspects of existing immunoassay technology will necessarily lead to the continued development of this already widely diverse subject.

Humans↗
PubMed1997

The association of herpes simplex virus type 2 (HSV-2), Haemophilus ducreyi, and syphilis with HIV infection in young men in northern Thailand.

To evaluate the association between sexually transmitted diseases that commonly may cause genital ulceration and prevalent and incident HIV infections, we conducted three case control studies in a cohort of 21-year-old male military conscripts in northern Thailand. The men were evaluated at baseline in 1991 and semiannually until their discharge 2 years later. Serologic evidence of infection with herpes simplex virus type 2 (HSV-2), Haemophilus ducreyi, and HIV were more frequent at baseline in 83 men with a history of genital ulcer than in 97 men without such a history. Seropositivity to H. ducreyi (odds ratio [OR] = 3.46), HSV-2 (OR = 3.83), and syphilis (OR = 1.53) were more common in HIV-positive than HIV-negative men. Men (N = 45) who seroconverted to HIV while in the military were more often seropositive for H. ducreyi and HSV-2 before HIV seroconversion and also were more likely to seroconvert to HSV-2 and H. ducreyi during the same interval as their HIV seroconversion compared with men who remained HIV-negative. These data suggest that HSV-2 and H. ducreyi may be both markers for high-risk sexual behavior and risk factors for HIV infection among young men in Thailand.

AIDS-Related Opportunistic Infections↗
PubMed1997

Risk factors for genital ulcerations in Kenyan sex workers. The role of human immunodeficiency virus type 1 infection.

BACKGROUND AND OBJECTIVES: Genital ulcer disease (GUD) is a major risk factor for human immunodeficiency virus (HIV) transmission. Cross-sectional studies have suggested that HIV infection may itself predispose to genital ulceration (GU). GOAL: To prospectively study the effects of HIV type 1 (HIV-1) infection and behavioral variables on GU incidence. METHODS: A cohort of 302 Kenyan female sex-workers was established in April 1991. Women were scheduled for assessment every 2 weeks, and bloods were collected every 6 months for HIV serology, rapid plasma reagin (RPR) and CD4 counts. Logistic regression was used to study risk factors for incident genital ulcers. RESULTS: 189 women (62.5%) had at least one incident ulcer over 24.3 +/- 15.3 months. GU incidence was higher in seropositive than initially seronegative women (82% vs. 48%; odds ratio [OR]) = 4.33; P < 0.01). Only HIV-1 seropositivity (OR = 3.42), a CD4 count < 200/ml (OR = 1.94), and oral contraceptive use (OR = 1.35) were associated (P < 0.05) with GU incidence in regression analysis. For those ulcers where an etiology was actively sought, Hemophilus ducreyi was confirmed in 54 (19%) of cases, and syphilis in 30 (29%). CONCLUSION: GU incidence in Kenyan sex workers is independently affected by HIV-1 serostatus, degree of immunosuppression, and oral contraceptive use.

Acquired Immunodeficiency Syndrome↗
PubMed1997

The role of international agencies in emerging infections.

Emergent and resurgent infections have no respect for national borders. Surveillance programmes, policies and practices, educational activities and control initiatives all require international leadership, multinational funding, and the ability to transcend national barriers if we are to prevent and control these infections. Society seems to expect us to organise ourselves to do this job well without building "impossible to maintain" barriers to the flow of people or goods. As a result, we must determine how international organisations, including United Nations agencies, international societies, and academic groups in universities, can work together with national organisations to achieve effective surveillance, ongoing education, important research and control initiatives to prevent infections from becoming an ever-increasing global threat to our security.

Drug Resistance, Microbial↗