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Biomedical subjects

D D Nicholas

Publications and source records attributed to D D Nicholas.

18 recordsLinked to original sources
PubMed2000

Naturally durable heartwood: evidence for a proposed dual defensive function of the extractives.

We previously proposed that extractives in highly durable heartwood may protect wood against fungal colonization and subsequent degradation by dual mechanisms: the extractives have some fungicidal activity and are also free radical scavengers (antioxidants). In short-term laboratory decay tests using two different wood species and decay fungi, the antioxidant 2,6-dimethyl-di-tert-butyl-4-methylphenol (BHT) alone had little or no preservative effect. In contrast, the combination of BHT with different organic commercial biocides always showed an increase in efficacy compared to the organic biocide alone. Consequently, we conclude that the combination of a commercial antioxidant and biocide is synergistic. This implies that extractives may protect wood by more than simply being fungicidal.

Antioxidants↗
PubMed1999

Comparative validity of three methods for assessment of the quality of primary health care.

OBJECTIVE: This study compared the sensitivity and specificity of three assessment methods to detect the performance of key clinical tasks by health workers in a primary care setting. DESIGN: Health worker performance during patient encounters for acute respiratory infections, acute diarrhea and family planning counseling was assessed through checklist-based observation of the consultation, interview with the mother following the consultation, and review of the patient's clinical record. The results of each method regarding the performance of key tasks by health workers were compared to a 'gold standard', defined as the application of the observation checklist by observers with extensive quality assessment experience. Patient encounters were studied in three Ministry of Health facilities in the Department of Totonicapán, Guatemala, involving care by physicians, nurses and auxiliary staff RESULTS: The three methods showed reasonably high levels of sensitivity (generally about 70%) for the detection of failures in the performance of most health worker tasks. The greatest problem experienced by each method related to specificity, i.e. capacity to recognize quality successes and only detect real failures. CONCLUSION: Direct observation demonstrated the best overall balance of sensitivity and specificity. Exit interview of the mother demonstrated good sensitivity and better specificity than record review.

Acute Disease↗
PubMed1991

The Quality Assurance Project: introducing quality improvement to primary health care in less developed countries.

Persistently excessive morbidity and mortality rates in less developed countries (LDCs) served by primary health care systems suggest that the quality of services is inadequate. The PRICOR project, sponsored by the United States Agency for International Development, has designed and implemented methods for quality assessment and problem solving in LDC health systems. After developing comprehensive lists of essential activities and tasks, similar to practice parameters, for seven child survival interventions, PRICOR supported comprehensive quality assessment studies in twelve LDC countries. The studies, yielding over 6000 observations of health worker-client encounters, indicated highly prevalent, serious program deficiencies in areas including diagnosis, treatment, patient education and supervision. To facilitate corrective action, PRICOR assisted managers in conducting operations research to resolve priority problems revealed by the assessments. The recently initiated Quality Assurance Project is building on PRICOR techniques in designing and implementing sustainable continuous quality improvement programs for LDC health systems.

Acute Disease↗
PubMed1979

Comparison of methods for estimating the frequency of paralytic poliomyelitis in developing countries.

Standard reporting systems have proved to be unreliable in estimating the frequency of paralytic poliomyelitis in many developing countries. The effectiveness of three survey methods for estimating the prevalence of lameness attributable to poliomyelitis were compared in the Danfa Health Project district of rural Ghana. Lameness was studied because it is easily identified by inexpensive survey techniques. A postal survey of school headteachers was the least costly and most accurate method, giving a prevalence of lameness attributable to poliomyelitis of 7.2 per 1000 schoolchildren. This method is recommended for countries with an extensive network of primary schools. Medical examinations in a village health survey yielded a prevalence of 4.6 per 1000 children aged 6-15 years. This method was relatively expensive but could be justified if the survey was multipurpose. A question added to the annual district census showed a prevalence of 2.2 per 1000 children, a rate still many times higher than estimates from national statistics. The inclusion of such a question in a census or other national survey entails little additional cost and with more careful questioning results should improve. Repeated surveys can be used to assess the success of poliomyelitis vaccination programmes.

Adolescent↗
PubMed1978

An evaluation of male contraceptive acceptance in rural Ghana.

To evaluate the effect of male contraceptive acceptance on fertility, the Danfa Family Planning Project in rural Ghana studied a sample of its male family planning acceptors. The findings show that half of the survey respondents accepted foam for use by their partners and half accepted the condom. The continuation rate (69 percent at 12 months) and use-effectiveness rate (80 percent at 12 months) reported by men were higher than those reported by women program acceptors. It is felt that men can play a significant role in affecting fertility through their influence on a couple's choosing to use contraception and as a result of their motivation to obtain contraception and see that it is used. It is urged that increasing emphasis be placed on providing family planning services for men in African programs.

Adolescent↗
PubMed1977

Outside Europe. Is poliomyelitis a serious problem in developing countries?--the Danfa experience.

Children were examined for lameness in the Danfa Project district of rural Ghana to assess the impact of endemic poliomyelitis and to test a widely held hypothesis that paralytic poliomyelitis is relatively rare in such districts (less than 1 per 1000 children affected). The observed prevalence of lameness attributable to poliomyelitis was 7 per 1000 school-aged children, and the annual incidence is estimated to be at least 28 per 100 000 population. Although no evidence for an epidemic was found, these rates are comparable with those in the USA and Europe during the years of severe epidemics and indicate that a high price is being paid in the Danfa district for the natural acquisition of immunity. As a result, immunisation against poliomyelitis has been given high priority. A teacher questionnaire was also tested for use in postal surveys as a rapid means of estimating the prevalence of lamenes attributable to poliomyelitis in countries with a reasonable network of primary schools.

Adolescent↗
PubMed1977

Is poliomyelitis a serious problem in developing countries?--lameness in Ghanaian schools.

A postal survey of lameness in schools throughout Ghana showed an estimated prevalence of lameness attributable to poliomyetitis of 5-8 per 1000 school-aged children and an estimated mean annual incidence of paralytic poliomyelitis of 23 per 100 000 population. Official reported incidence rates range from 0-1 to 2-1 per 100 000 population, indicating that at least 90% of cases are not reported. No evidence of epidemics was found to account for these high rates. These suggest that mean annual incidence rates in tropical endemic countries have always been as great, if not greater, than those experienced by temperate countries during epidemic periods in the twentieth century and that the total number of cases of paralytic poliomyelitis occurring in the world each year has been reduced by only 25% since the advent of polio vaccine. Immunisation against poliomyelitis must have a high priority in Ghana and other tropical countries where the disease is endemic.

Adolescent↗
PubMed1977

Haematological values in a rural Ghanaian population.

Early in 1973 residents of 20 randomly selected rural villages in southern Ghana were studied to determine the prevalence of anaemia. Laboratory tests were conducted to learn what haemoglobin phenotypes were present and the distribution of white blood cell counts. Moderate anaemia (below 10 g%) was fairly common, particularly in children and 15--29 year old women, but severe anaemia (below 7 g%) was rare. Malaria infection and diets with low iron content were major factors affecting haemoglobin level, while hookworm infestation and high parity had little effect. Neutropenia (about two-thirds of Caucasian values) and the distribution of haemoglobin types (AS 16.3%; AC 11.1%) were similar to findings in earlier studies. To improve haemoglobin levels in children and young women, low-cost intervention programmes based on volunteer village workers are recommended.

Adolescent↗
PubMed1977

The training of traditional birth attendants in Ghana: experience of the Danfa Rural Health Project.

Three quarters of deliveries in Ghana are still attended by untrained personnel, including traditional birth attendants (TBA's), and maternal mortality remains high. The Ministry of Health is exploring ways of improving this situation. Recently, training traditional birth attendants to improve maternal and child health practices and promote family planning has been considered. Most TBA's in rural Ghana are elderly illiterate farmers. The Danfa Project has identified and trained 57 of these TBA's with the objective of developing a programme that might be replicated elsewhere in the country. This paper describes the design of the programme and problems encountered and makes recommendations to others who may be considering similar programmes in other countries.

Female↗