Biomedical subjects

M Senekal

Publications and source records attributed to M Senekal.

10 recordsLinked to original sources

PubMed2006

The effect of prebiotics on production of antimicrobial compounds, resistance to growth at low pH and in the presence of bile, and adhesion of probiotic cells to intestinal mucus.

AIMS: Screening of five bile salt-resistant and low pH-tolerant lactic acid bacteria for inhibitory activity against lactic acid bacteria and bacterial strains isolated from the faeces of children with HIV/AIDS. Determining the effect of prebiotics and soy milk-base on cell viability and adhesion of cells to intestinal mucus. METHODS AND RESULTS: Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF 38 and Pediococcus pentosaceus 34 produced the highest level of antimicrobial activity (12,800 AU ml(-1)) when grown in MRS broth supplemented with 2% (m/v) dextrose. Growth in the presence of Raftilose Synergy1, Raftilose L95 and Raftiline GR did not lead to increased levels of antimicrobial activity. Cells grown in the presence of Raftilose Synergy1 took longer to adhere to intestinal mucus, whilst cells grown in the absence of prebiotics showed a linear rate of binding. CONCLUSIONS: A broad range of gram-positive and gram-negative bacteria were inhibited. Dextrose stimulated the production of antimicrobial compounds. Adhesion to intestinal mucus did not increase with the addition of prebiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: The strains may be incorporated in food supplements for HIV/AIDS patients suffering from gastro-intestinal disorders.

Anti-Bacterial Agents↗

PubMed2005

Development of a reliable and valid nutritional knowledge questionnaire for urban South African adolescents.

OBJECTIVES: We wanted to develop a valid and reliable nutritional knowledge test for urban South African adolescents who were participating in the Birth-to-Twenty cohort study. The questionnaire was intended for use every second year, from ages 13 to 14 y until age 20 y. METHODS: The initial steps involved the development of a conceptual framework and identification of nutritional concepts in collaboration with nutritional experts, and this defined the construct of the questionnaire. The South African national teaching curriculum objectives for nutritional education and other relevant issues were selected as the desired concepts, and most items were phrased in accordance with the recently developed South African Food-Based Dietary Guidelines. Thereafter, 140 items (questions) were developed and in turn assessed by an expert panel, and the result was that only 88 items remained. This was done to ensure content and face validity of the items. The 88 items were constructed into a questionnaire and piloted for appropriateness and understanding by adolescents, ages 13 to 14 y, as a means of assessing face validity by non-experts. The edited preliminary questionnaire (still with 88 items) was administered to a nutrition expert group (n = 71) versus a non-expert group (n = 82), referred to as sample 1, for the purposes of performing item analysis and assessing construct validity of the questionnaire. The result of the analysis, a 63-item questionnaire, was administered to adolescents at three school grade levels, 8 (n = 128), 10 (n = 143), and 12 (n = 98), referred to as sample 2, which was representative of the grades in which the Birth-to-Twenty group will be in when the questionnaire is administered. The questionnaire was administered to the sample to assess its content validity and internal consistency reliability. The final questionnaire had 60 items, and its construct, content, and internal consistency reliability were reassessed. RESULTS: The final 60-item questionnaire displayed a significant difference (P < 0.0001) in the mean scores of the expert and non-expert groups tested. It had internal consistencies (Cronbach's alpha) of 0.71, 0.79, and 0.82 for grades 8, 10, and 12 respectively, and an overall value of 0.77 for all groups combined. However, it was less than 0.7 for most grade 8 pupils and for all grades at a historically disadvantaged school. CONCLUSION: A nutritional knowledge questionnaire with construct, face, and content validities and internal consistency was developed for use in South African adolescents to evaluate their nutritional knowledge. Internal consistency was low in children at a disadvantaged school and those in grade 8 compared with multiracial groups at a multiracial school. It is recommended that pupils at disadvantaged schools be assisted by trained interviewers when taking the test.

Adolescent↗

PubMed2005

Market and product assessment of probiotic/prebiotic-containing functional foods and supplements manufactured in South Africa.

OBJECTIVES: Probiotic and prebiotic products manufactured in South Africa were identified and health and content claims stated on the labels were evaluated according to available scientific evidence, the proposed South African regulations in the Foodstuffs, Cosmetics and Disinfectants Act (Act No. 54 of 1972, www.doh.gov.za), and microbial assessment. RESULTS: The range of products identified included probiotic- and/or prebiotic-containing supplements (capsules), food items fortified with probiotics and/or prebiotics, and fermented food containing probiotics, e.g. dairy products. Most of the health-related claims on the labels of the identified products do not comply with proposed South African regulations. However, results also indicate that the proposed South African regulations should be reconsidered to include an additional 5 claims, for which scientifically sound evidence is available. The claims regarding probiotic strains, viable cell numbers, prebiotic type and concentration stated on the labels of the products are mostly in line with the proposed South African regulations. The actual viable cell content of 3 out of 5 probiotic supplements readily available on the South African market did not comply with the content claim stated on the label. However, this problem did not seem to affect the inhibitory activity of the probiotic strains against indicator strains isolated from faeces of patients diagnosed with AIDS. To validate this finding in vivo assessments should be implemented before considering the need to include a wider range of prescribed viable cell numbers in the proposed South African regulations. CONCLUSIONS: The proposed South African regulations regarding probiotic- and prebiotic-containing products should be revised based on the results of this research, and the manufacturers of these products should be held responsible for providing the consumer with scientifically sound and legally correct information.

Consumer Product Safety↗

PubMed2004

Appropriate use of the carbapenems.

The carbapenems are a group of broad-spectrum beta-lactam antibiotic agents of which there are three parenteral preparations currently available in South Africa, namely imimpenem/cilastatin, meropenem and ertapenem. Owing to the fact that imipenem/cilastatin and meropenem have a broad spectrum of activity that includes Pseudomonas and Acinetobacter species, they are ideal antibiotics for treatment of severe nosocomial infections. In contrast, ertapenem has limited in vitro activity against the latter non-fermentative gram-negative bacteria and is therefore more suitable for the treatment of certain severe community-acquired infections. This statement arises out of concerns about the general abuse of antibiotics such as the carbapenems, with the primary intention of highlighting the appropriate use of these agents.

Anti-Bacterial Agents↗

PubMed2002

Determinants of growth failure in 12-24-month-old children in a high-density urban slum community in East London, South Africa.

OBJECTIVE: The study's main objectives were the identification of determinants of growth failure in 12-24-month-old children from an urban slum community attending a day hospital as well as the identification of focus areas for intervention. DESIGN: The research was executed as a case-control study with a one-to-two design. A hypothetical causal model was developed for the undernutrition situation in Duncan Village. A questionnaire to assess the direct and underlying causes of growth failure in the study population was developed from this model. SUBJECTS: One-hundred and fifty children were selected for the study, with 100 children in the control group and 50 children in the growth-failure group. Each child in the growth-failure group was matched with two children in the control group based on age and sex. The children were chosen according to anthropometric indices and p-albumin levels. SETTING: The research was conducted at a primary health care centre in Duncan Village, an overpopulated urban slum area in East London, a small city on the east coast of South Africa. RESULTS: No significant differences were found between the two groups for the occurrence of disease and infection. Dietary intake seemed to be generally poor in all the children. No significant differences were found between the two groups for the indicators of household food security, health service utilization and environmental conditions. The most important underlying determinants of growth failure that were identified in the study population seem to be related to the caring capacity, and the resultant caring behaviours of mothers. The risk for growth failure is increased when a child has a mother who is not the head of the household (relative risk) (RR=4.3), who is not involved with the discipline of her children (RR=2.2), who is not the guardian of the child (RR=8), who was not born in Duncan Village or in a city (RR=2.16), who is not able to write (RR=2.7) or read Xhosa (RR=2.53), who has a school education of <or=grade 9 (RR=2.9), who did not receive nutrition education (RR=2.2), who smokes (RR=10) and drinks beer regularly (RR=10), who has a BMI <25 (RR=2.7), who was subjectively judged to show little interest in her child (RR=4) as well as an inadequate caring attitude towards her child (RR=3.61), and whose clothing was dirty (RR=2.7) and not tidy (RR=2.9). Further determinants included the following: a child who weighed <2500 g at birth (RR=4.96), who had not received supplemental milk while still breast-fed (RR=2.00), who did not receive baby cereal as first food (RR=2.6), whose clothes (RR=2.7) were dirty and whose hands were infrequently washed (RR=10). CONCLUSIONS: The results of this research suggest that initiatives to address the problem of growth failure in 12-24-month-old children attending the Duncan Village Day Hospital should focus mainly on improving the caring capacity of mothers in the study area.

Case-Control Studies↗

PubMed2001

The accuracy of self-reported weight by overweight and obese women in an outpatient setting.

OBJECTIVE: To investigate the accuracy of self-reported weight of overweight and obese women and characterisation of under-, correct- and over-reporters based on a number of related variables. DESIGN: Weight was self-reported before entering the study. At baseline, actual weight was recorded, and demographic, health, nutritional, psychological and physical activity questionnaires were completed. SETTING: A hospital outpatient department. SUBJECTS: Participants were 131 women aged 18-64 years with a body mass index attending a Comprehensive Weight Management Programme. OUTCOME MEASURES: The accuracy of self-reported weight was investigated for the total group, and the subjects were then categorised into three groups according to accuracy of self-reported weight (under-, correct- and over-reporters). The relationship between these accuracy groups and demographic, health, nutritional, and psychological variables and physical activity was examined, to characterise the under-, correct- and over-reporters. RESULTS: Although not statistically significantly different, the total group of women tended to underestimate their weight by 0.8 (+/-3.6) kg. Categorisation according to the accuracy groups revealed that 29% underestimated their weight by 2 kg or more, 19% overestimated their weight by 2 kg or more, and only 52% correctly estimated their weight within 2 kg. Some trends and statistically significant differences between the accuracy groups concerning certain variables, e.g. height, age, income, education, contraceptive pill usage, smoking and food choices were evident. CONCLUSIONS: Self-reported weight of a group of overweight/obese individuals may be a valid and reliable indicator of actual weight, but self-reported weight of an overweight/obese individual can not be interpreted similarly. Further research is necessary to ensure reliable characterisation of under-, over- and correct reporters.

Adolescent↗

PubMed2000

Weight and health status of black female students.

OBJECTIVE: To examine black female students for the occurrence of risk factors associated with chronic diseases of lifestyle, namely obesity, hypertension, nicotine usage, dyslipidaemia and compromised mental health (depression). DESIGN: A cross-sectional analytical study design was used. All participants were examined within a period of 3 months during 1994. Weight, height, and hip and waist measurements were taken. Body mass index (BMI), waist-hip ratio (WHR) and waist circumference (WC) were calculated for each subject. Two systolic and diastolic blood pressure readings were taken for each participant. Questionnaires were used to determine specific risk factors related to lifestyle. The Beck Depression Inventory (BDI) was used to measure psychological well-being. Fasting blood samples were collected and analysed for serum lipids and iron status. SETTING: The University of the North in the Northern Province of South Africa. SUBJECTS: A complete data set of sociodemographic information, anthropometric measurements and blood pressure readings, as well as a psychological health test and a medical questionnaire, were obtained from 231 of the 431 first-year female students who attended the university orientation programme. Only students with a complete data set were included in the sample. RESULTS: Eighteen per cent of students were overweight (BMI 25-29.9), 6.5% were obese (BMI > or = 30), and 26.8% were underweight. Mean blood pressure, BMI, WHR and WC increased significantly with age and were highest among the > or = 24-year-olds. Only 1.6% of students had elevated blood pressure, 1.0% smoked and 4.4% took snuff. BMI, WC and WHR were positively correlated with blood pressure and age. Few students had dyslipidaemia (3.8% cholesterol > 5.2 mmol/l). However 14.5% were anaemic (Hb < 11.5 g/dl) and 24.6% had microcytosis (< 80 fl). Nearly one-fifth of students (17.7%) were classified as being moderately to severely depressed. CONCLUSIONS: Black female students younger than 24 years exhibited few risk factors associated with chronic diseases of lifestyle. However in older women (> or = 24 years) there were significant increases in BMI, WHR, WC and blood pressure. A large number of students of all ages exhibited moderate to severe depression and anaemia was prevalent.

Adolescent↗

PubMed1999

A multidimensional weight-management program for women.

Real and imagined overweight and obesity, and resulting weight-reduction efforts, are associated with the development of a variety of health problems and eating disorders. For many years, research and practice in the field of weight management have been based largely on a unidimensional, simplistic, weight-loss paradigm. The long-term success rate for persons using this paradigm has been low. This article presents a multidimensional paradigm that focuses on all aspects of the prevention, treatment, and management of weight-related problems. The goal is to stimulate a shift from the unidimensional to a more multidimensional approach in weight-management interventions. The paradigm presents weight management as a continuum on which 5 prominent points are identified: formulation of reasonable weight goals, prevention of unnecessary weight; gain or loss, weight loss when necessary, prevention of relapse, and acceptance of an overweight/obese physique when necessary. The intrapersonal characteristics and skills associated with this continuum, namely, self-esteem, body image, self-efficacy, locus of control, motivation, stress management, problem solving and decision making, and assertiveness, as well as the role of stage of change and environmental influences on weight management, are examined. Issues concerning the different dimensions of the paradigm are discussed as are challenges and applications for researchers and practitioners in the field of weight management.

Behavior Therapy↗

PubMed1996

Community-acquired Pseudomonas aeruginosa infection in an infant.

A 7-month-old infant presented at a tertiary centre with a 6-day history of a skin rash, fever and diarrhoea. Clinical features included pyrexia, kwashiorkor, extensive ulcerating skin lesions suggestive of ecthyma gangrenosum, hepatomegaly, meningismus, neutropenia and iron deficiency anaemia. Blood and skin aspirate cultures yielded a positive growth of Pseudomonas aeruginosa. Apart from severe protein energy malnutrition, no other causes of immunodeficiency were found. He responded well to parenteral antibiotic therapy with gentamicin and piperacillin.

Anti-Bacterial Agents↗

PubMed1995

Penetrating stab wounds of the chest--when should chest physiotherapy commence? A comparative study.

In an effort to optimise the physiotherapy management of patients with penetrating stab wounds to the chest, 26 male patients, aged between 18 and 30 years, were randomised to one of two groups on admission to Hillbrow Hospital. The patients in group I received chest physiotherapy immediately after insertion of the intercostal drain, while patients in group II received chest physiotherapy 9-12 hours after insertion of the drain as is currently the normal hospital procedure. Mean duration of intercostal drainage in group I was 40 hours and that in group II 65.92 hours. Patients in group I had significantly shorter intercostal drainage times than patients in group II (P = 0.0001). Patients in group I had a mean hospital stay of 43.96 hours while patients in group II had a mean hospital stay of 77.53 hours (P = 0.0001). There was a significant difference in the duration of hospitalisation between the two groups, this being shorter in group I than in group II. The prevalence of spiking temperatures was also significantly lower in group I than in group II, since only 2 patients in group I but 8 patients in group II developed a spiking temperature (P = 0.0207). This study suggests that an aggressive approach of immediate chest physiotherapy in these patients has definite beneficial results.

Adolescent↗