Urbanisation and adolescent risk behaviour.

OBJECTIVE: To investigate whether there is an association between the length of time lived in an urban area and selected adolescent risk behaviours. DESIGN: Cross-sectional survey in which students completed an anonymous, confidential questionnaire. SETTING: Four high schools in black communities in the Cape Peninsula, South Africa. PARTICIPANTS: A sample of 1,296 students obtained by multistage cluster sampling. MAIN OUTCOME MEASURES: Selected risk behaviours. RESULTS: There is a relationship between urbanisation and certain risk behaviours. The following risk behaviours were associated with urbanisation: use in the previous month of alcohol, cannabis, and cannabis mixed with Mandrax; being a victim of violence; perpetration of an act of violence; and suicidality. Conversely, participation in sexual intercourse and solvent sniffing in the previous month were not associated with urbanisation. CONCLUSION: Urbanisation is associated with an increase in the prevalence rates of some risk behaviours. Mental health promotion efforts may be informed by further research aimed at the identification of: (i) the characteristics of risk behaviour that determine whether it is associated with urbanisation; and (ii) where applicable, the specific aspects of the urbanisation process that contribute to an increase in risk.

Adolescent contraceptive non-use and covariation among risk behaviors.

PURPOSE: To investigate whether adolescent contraceptive non-use is associated with other risk behaviors. METHODS: A multistage sampling procedure produced a sample of 913 sexually active high school students. They completed a self-administered questionnaire that required mainly "yes" or "no" answers to questions involving participation in a range of risk behaviors. A series of multivariate logistic regression models investigated the relationships between contraceptive non-use and selected hypothesised correlates, controlling for key demographic variables. RESULTS: Contraceptive non-use was not significantly associated with use of cigarettes, alcohol, or inhalants; perpetration or being a victim of violence; exposure to risk of physical injury; and suicidality. For males only, there was a significant inverse association between contraceptive non-use and use of cannabis in the previous month. This was not the case for lifetime cannabis use for either gender. There was a significant inverse relationship between contraceptive non-use and knowing the most recent partner for more than 7 days, but no association for the number of partners nor duration since the last intercourse. For females only, there was a significant inverse association between contraceptive non-use and both age and age of first intercourse. CONCLUSIONS: This study does not support the hypothesis that contraceptive non-use is a component of the "risk behavior syndrome." Decisions to participate in intercourse and to use contraception have different psychosocial foundations. Prevention efforts should prioritize relationships with new partners and younger girls who commence intercourse early.

Performance of the Diagnostic Interview Schedule for Children Version 2.3 (DISC-2.3) in an informal settlement area in South Africa.

OBJECTIVE: To investigate the performance of the Xhosa Diagnostic Interview Schedule for Children Version 2.3 (DISC-2.3) in a community study of African children and adolescents in Khayelitsha, a largely informal settlement area in Cape Town, South Africa. METHOD: A cross-sectional community study of 500 youths aged 6 to 16 years was undertaken using a systematic sampling strategy based on random starting points in the community. Three trained Xhosa-speaking lay interviewers administered the DISC-2.3 to youths and their parents in their homes. Additional questions included degree of impairment, selected risk factors, and service use. RESULTS: The administration of the Xhosa DISC-2.3 in an informal settlement area was both feasible and acceptable to respondents. Psychiatric disorder with impairment was recorded for 76 (15.2%) of the children and adolescents. Consultation had been sought in only 20 cases, mostly from medical doctors, except for 3 who had attended indigenous healers. Rates of disorder were significantly higher among respondents who were living in unserviced areas or who came from homes where food was needed. CONCLUSIONS: The DISC is a potentially useful instrument even in the presence of major constraints on conducting epidemiological research.

Nuclear distribution of human DNA topoisomerase IIbeta: a nuclear targeting signal resides in the 116-residue C-terminal tail.

We have analyzed the subcellular distribution of the beta isoform of human topoisomerase II using both isoform-specific antisera and an epitope-tagging approach. Previous immunocytochemical studies have yielded differing results with one reporting this isoform to be predominantly nucleolar. Later studies seem to refute this finding, as do our results with isoform-specific antisera reported here. Epitope tagging minimizes potential complications arising from the use of anti-topoisomerase II antisera that may recognize epitopes that are modified or masked in vivo and could lead to misleading results in immunocytochemical studies. A second strength of this approach is that it allowed a comparison with similarly tagged control proteins (derived from the nucleolar transcription factor UBF) that were known to localize unambiguously to the cytoplasmic, nucleoplasmic, or nucleolar compartments. We report that the C-terminal domain of topoisomerase IIbeta fused to a beta-galactosidase tag localizes to the nucleus (but not the nucleolar compartment) and that this is indistinguishable from the localization of native topoisomerase IIbeta detected by isoform-specific antisera. Further analysis revealed that the nuclear localization determinant lies within the 116-residue C-terminal tail of human topoisomerase IIbeta.

Atherosclerosis: aortic lipid changes induced by diets suggest diffuse disease with focal severity in primates that model human atheromas.

Atherosclerosis in Vervet or African Green monkeys (Cercopithecus aethiops) models the morphology and cytology of the disease of humans, and it is well established that the rate of atherogenesis in Vervets is influenced by diet. Aortic intimal concentrations of lipids and phospholipids known to be major components of atheromas were determined in female Vervets fed for 4 years on either an atherogenic (AD) or a prudent Western diet (PD). Lipid concentrations detectable microscopically as cholesterol crystals and foam cells were confirmed biochemically. In addition, the AD was associated with diffuse, invisible accumulation of lipids throughout aortic tissue to the extent that tissue with no fatty streaks or plaque (AD) contained the same or more lipids than visible fatty streaks (PD). Correlations between lipid concentrations and atherosclerosis were highly positive, which supports known correlations between aortic, plasma, and dietary lipids during atherogenesis, and validates the aortic lipid analysis. These aortic lipid concentration results imply that atherosclerosis is not confined to focal pathologic anatomy, but in terms of lipid components of the disease, it develops throughout the arterial system of Old World omnivorous primates. If the results are applicable to people, they provide new insight and emphasize the need to minimize dietary sources of atherogenic lipids.

Granulocyte proteins in serum in childhood asthma: relation to spirometry and therapy.

BACKGROUND: Measurement of markers of eosinophil activation in asthmatics provides information indicative of ongoing inflammatory processes in the airways. OBJECTIVES: This study was conducted to determine the correlations between serum markers of allergic inflammation with spirometry parameters in asthmatic children in different treatment groups. METHODS: Blood eosinophils, serum levels of eosinophil cationic protein (ECP), eosinophil protein X (EPX), myeloperoxidase (MPO) and tryptase were measured simultaneously with serial measurements of FEV1/FVC, FEF25-75 and FEF in 60 children with acute asthma on admission and after 2, 14, 30 and 60 days. Group A received bronchodilators only (n = 20), group B received sodium cromoglycate (SCG) (n = 20) and group C received oral and/or inhaled corticosteroids (n = 20). RESULTS: Oral steroid treatment (2 mg/kg/day), given at the onset of the asthma attack, resulted in significant reduction in the ECP and EPX levels in all the children. However, these reduced ECP and EPX levels were not sustained in the children, even in those who continued on maintenance steroid treatment. Significant, but inconsistent, correlations between ECP, EPX with total eosinophil count, Percentage eosinophils and spirometry parameters were observed at the different time-points. Tryptase levels were normal in all subjects. There were no significant correlations between myeloperoxidase levels and the spirometry parameters or eosinophil parameters. Serial monitoring of ECP and EPX levels was found to be of some use in predicting clinical outcome in certain steroid-dependent asthmatics (group C) but of no value in the mild asthmatics (group A). CONCLUSION: While elevation of ECP, EPX and MPO in the serum of childhood asthmatics suggests ongoing inflammation and may inversely correlate with spirometry parameters in some patients, the relationship between these markers and airway function is not a simple one.

Risk-taking behaviour of Cape Peninsula high-school students. Part IX. Evidence for a syndrome of adolescent risk behaviour.

OBJECTIVES: To ascertain whether the notion of a syndrome of adolescent risk behaviour (which includes problem drinking, marijuana use, having experienced sexual intercourse, 'general deviance' and cigarette smoking) is valid for this setting; and to investigate whether suicidal behaviour and behaviour that exposes the adolescent to injury should be included in this syndrome. DESIGN: Cross-sectional survey utilising a self-completed questionnaire; for both sexes, relationships between behaviours were documented as odds ratios. SETTING: High schools in the Cape Peninsula, South Africa. SUBJECTS: 7,340 students from 16 schools in the three major education departments. OUTCOME MEASURES: Participation in the following behaviours: alcohol bingeing, cannabis smoking, sexual intercourse, knife-carrying at school, cigarette smoking, attempting suicide, failure to use a seat belt, and walking home at night from beyond the neighbourhood. RESULTS: All the odds ratios were greater than 1. There were statistically significant odds ratios between all the pairs of risk behaviours included in the 'original' syndrome of risk behaviour except for cigarette smoking and having had sexual intercourse in the case of girls. There were statistically significant relationships between all these risk behaviours, suicidal behaviour, and behaviours that exposed the adolescent to risk of physical injury, except for failure to use a seat belt and: (i) suicidal behaviour for both sexes; and (ii) walking home alone at night and having had sexual intercourse in the case of girls. CONCLUSION: The notion of a syndrome of adolescent risk behaviour is valid for this population, and both suicidal behaviour and behaviour that exposes the adolescent to injury should be included in this syndrome.

Risk-taking behaviour of Cape Peninsula high-school students. Part X. Multivariate relationships among behaviours.

OBJECTIVE: To investigate the relationship between adolescent risk behaviours, taking into account their influence upon one another. DESIGN: Cross-sectional survey utilising a self-completed questionnaire; stepwise logistic regression analyses were carried out, stratified for gender. SETTING: High schools in the Cape Peninsula, South Africa SUBJECTS: 7,340 students from 16 schools in the three major education departments. OUTCOME MEASURES: The outcome variables for each regression model were: cigarette smoking, cannabis smoking, alcohol bingeing, sexual intercourse, knife-carrying at school, walking home at night from beyond the neighbourhood, attempting suicide, and failure to use a seat belt. For each model, 26 risk behaviours served as independent variables. RESULTS: For each model, between 3 and 9 variables qualified for inclusion for each gender. There was a substantial association between many forms of substance abuse. In the previous 12 months, suicidal thoughts or statements of suicidal intent were predictors of a suicide attempt. Several variables involving injury were predictors of exposure to danger in getting home at night, and this was a predictor of substance abuse. Cannabis smoking, alcohol bingeing and exposure to danger in getting home at night were predictors of and were predicted by having had sexual intercourse. CONCLUSION: There are significant relationships between many adolescent risk behaviours, even when the influence of other risk behaviours is taken into account. The probability of adverse sequelae of risk behaviours, such as exposure to danger in getting home at night and sexual intercourse, is increased by the presence of selected other risk behaviours.

Apolipoprotein B levels and related factors in a rural white South African community--the CORIS study. Coronary Risk Factor Study.

OBJECTIVE: In a survey of the Coronary Risk Factor Study (CORIS), apolipoprotein B (apoB) levels were determined to ascertain their impact on coronary heart disease (CHD) risk. Other CHD risk factors associated with apoB were also identified. DESIGN: Cross-sectional analytical study, which included CHD risk factor and dietary questionnaires, electrocardiography, anthropometric and blood pressure measurements, and a blood sample for a lipid profile. SETTING AND PARTICIPANTS: The three districts of Riversdale, Robertson and Swellendam in the south-western Cape; a 25% random sample of 1,528 white respondents aged 15-68 years. RESULTS: Men tended to have higher mean apoB levels than women. Classification of CHD risk by apoB levels and total cholesterol (TC) levels did not correspond, as only 61% of men and 58.5% of women were classified in the same risk categories. Respondents in the highest apoB risk category reported a medical history of hypercholesterolaemia and hypertension more frequently than those in lower categories. There was a significant increase from the low to the high apoB risk category of TC, low-density lipoprotein (LDL) cholesterol, triglyceride levels, body mass index and percentage body fat. Using stepwise multiple regression, 84.9% of the variation in apoB of men and 85.8% in apoB of women were accounted for by significantly associated variables. CONCLUSION: Although apoB may be a better predictor of CHD than TC or LDL cholesterol concentrations, its easy approximation with the formula (TC-HDLC)/2 + 20, high cost, measurement variability and an approach in management similar to that for raised TC discourage its routine use in the screening of patients for CHD.

Effect of chilli (Capsicum frutescens) extract on proliferation of oral mucosal fibroblasts.

Various concentrations of chilli extract were tested in 2 stages on the growth of a human buccal mucosa fibroblast cell line. Firstly, concentrations of 25, 75, 150 and 300 micrograms/ml were tested on the cell line for 6 days followed by a repeat which included concentrations of 400 and 500 micrograms/ml. In the latter, cell growth was monitored for 18 days. From day 3 (72 hr) suppression of cell growth was evident with concentrations 300-500 micrograms/ml. Total cell death occurred at 16 days with 300 micrograms/ml and at 6 days with 400-500 micrograms/ml. With the lower concentrations, 25-150 micrograms/ml, the daily counts were lower than the control but the difference was not statistically significant. Growth continued unabated. It is therefore concluded that cytopathic effect of chilli extract to fibroblasts is concentration dependent.

Disordered water homeostasis in schizophrenia and cerebral ventricular size.

BACKGROUND: A possible association between disordered water homeostasis and cerebral ventricular size in patients with schizophrenia was investigated. METHOD: In a cross-sectional study of hospitalised patients, cerebral ventricular size was measured in 16 schizophrenic patients with disordered water homeostasis and 16 matched schizophrenic controls by magnetic resonance imaging. RESULTS: Ventricle to brain ratio, third ventricular index, bicaudate index and bifrontal index tended to be greater in those with schizophrenia with disordered water homeostasis, although differences were significant only for the bifrontal index (P < 0.05). Strong negative correlations were found between ventricular size and performance on neuropsychological testing in the disordered water homeostasis group. CONCLUSION: These results provide evidence for an association between structural brain abnormality and disordered water homeostasis in a subset of schizophrenic patients.

Responsiveness of Keitel functional index compared with laboratory measures of disease activity in rheumatoid arthritis.

This study compares functional changes to change in measures of disease activity following the introduction of slow-acting anti-rheumatic drugs (SAARD) in patients with active rheumatoid arthritis (RA). Clinical and laboratory variables were simultaneously monitored at 6-monthly intervals, over approximately 18 months. Function was measured by a performance testing, the Keitel function index (KFI), which was divided into sections representing small and large joints [hand (HFI); wrist (WFI) and limb function index (LFI)]. One-hundred-and-fifteen patients were studied, of whom 21 were male. The mean age of the subjects was 49 yr (S.D. +/- 12) and mean duration of disease 7 yr (S.D. +/- 7). The mean KFI at entry was 38 (S.D. +/- 18) while at the end of the study it was 31 (S.D. +/- 17) (P < 0.0001). The change in KFI following therapy correlated with the change in Ritchie articular index (RAI) (r = 0.4; P < 0.0001), early morning stiffness (EMS) (r = 0.3; P = 0.004), swollen joint count (JC) (r = 0.4; P = 0.0005), C-reactive protein (CRP) (r = 0.2; P < 0.05) and Lansbury systemic index (LSI) (r = 0.35; P = 0.002), but not with change in Westergren erythrocyte sedimentation rate (ESR) or change in time to onset of fatigue. Multiple regression analysis showed that 32% of the variation in KFI at the end of the study could be predicted by a combination of ESR, sulphasalazine therapy, RAI, disease duration and chloroquine treatment at onset (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Lidocaine extraction by the in vivo and isolated perfused pig liver.

Hepatic lidocaine elimination is increasingly being used to assess hepatic function. Although the isolated liver is extensively used as a model of in vivo function, it is necessary to determine whether this is a suitable model for in vivo lidocaine elimination. Fourteen male pigs (22-25 kg) were divided into two groups. Seven were anesthetized, and catheters and perivascular flow probes placed for transhepatic sampling and hepatic arterial and portal venous flow measurement. Sampling was performed at hourly intervals to determine hepatic function and plasma composition. Hepatic lidocaine elimination was determined during the second hour of a lidocaine infusion (1.41 mg.kg-1.min-1 for 10 min, then 0.165 m.kg-1.min-1), during which time the mean hepatic blood flow rates, plasma acid base status and body temperature were measured so that these could be emulated in the isolated perfused liver experiments. Seven male pigs were then anesthetized and the liver resected and cannulated for isolated liver perfusion. Hepatic arterial and portal venous blood flow and perfusate temperature were set to the mean in vivo values, and hepatic function and perfusate composition assessed at corresponding times. Hepatic lidocaine elimination was determined at a similar hepatic inflow whole blood concentration (+/- 5 micrograms.ml-1) to that in vivo over the second hour of lidocaine administration (40 mg bolus, then 2.8 mg.min-1). Lidocaine extraction ratio in vivo (0.61 +/- 0.04) [mean +/- SEM] and ex vivo (0.63 +/- 0.02) was similar, as was hepatic blood clearance (381 +/- 70 vs 363 +/- 16 ml.min-1) and hepatic blood intrinsic clearance (1132 +/- 280 vs 1069 +/- 109 ml.min-1).(ABSTRACT TRUNCATED AT 250 WORDS)

The intervention effects of a community-based hypertension control programme in two rural South African towns: the CORIS Study.

The objective of the hypertension programme of the Coronary Risk Factor Study (CORIS) was to evaluate the effectiveness of the first 4 years of community-based intervention. The hypertension intervention model comprised a blood pressure station where the whole population was screened for hypertension, non-drug management was provided and hypertensives were monitored after referral to general practitioners for drug therapy. Two levels of intervention were maintained: in the high-intensity intervention town (N = 2,278) hypertensives were actively followed up, and in the low-intensity intervention town (N = 2,620) no active follow-up procedure existed. A third town acted as control (N = 2,290). In the cohort which was hypertensive at baseline, the net decreases in systolic blood pressure (mean +/- SE) after correction for changes in the control town were 0.5 +/- 2.2 mmHg (men) and 4.5 +/- 2.2 mmHg (women) in the low-intensity intervention town, and 5.6 +/- 2.3 mmHg (men) and 7.5 +/- 2.2 mmHg (women) in the high-intensity intervention town. The net decrease in diastolic blood pressure was 3.4 +/- 1.2 mmHg (men) and 4.4 +/- 1.1 mmHg (women) in the low-intensity intervention town, and 6.1 +/- 1.2 mmHg (men) and 5.9 +/- 1.1 mmHg (women) in the high-intensity intervention town. These reductions were statistically significant with one exception. The changes in the total population in the 3 communities after 4 years of intervention were similar to those found in the hypertensive cohort.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of lidocaine on in vivo hepatic function.

Lidocaine is administered to assess donor or recipient liver function during hepatic transplantation. This study was performed to determine whether lidocaine administered at a constant concentration affected hepatic function or had demonstrable effects on hepatocellular ultrastructure. Fourteen pigs were randomly allocated to receive either a two-stage infusion of lidocaine hydrochloride or of saline. Transhepatic blood samples were taken and ultrasonic portal venous and hepatic arterial blood flow readings made on animals anesthetized with isoflurane in nitrous oxide. Liver biopsies were taken for histological analysis and determination of adenine nucleotide status prior to and after 2 hr of the two-stage infusion. A mean systemic constant plasma lidocaine concentration of 5.9 micrograms/ml was achieved during the second hour of infusion. There were no differences between the two groups in a large number of indices of hepatic function and plasma composition prior to and during the second hour of the respective infusions. Hepatic blood flow was also similar at these times. On histological examination there were no electron microscopic changes that could be specifically attributed to the administration of lidocaine. However, there were progressive changes with time. This study suggests that in anesthetized pigs a constant lidocaine concentration of about 6 micrograms/ml has no detrimental effect on hepatic function. Progressive hepatic ultrastructural changes occurred that could not be attributed to the administration of lidocaine. These may be the result of anesthetic administered or the surgery performed.

Disordered water homeostasis and cognitive impairment in schizophrenia.

To investigate a possible association between disordered water homeostasis and cognitive impairment in schizophrenia, neuropsychological tests were applied to 16 schizophrenic patients with severely deranged water homeostasis and to 16 matched schizophrenic controls. The patients with disordered water homeostasis tended to obtain poorer scores than the controls throughout, the differences being statistically significant for two of the tests (Wechsler Memory Scale Visual Reproduction and Trial Marking Test part A). These results were not ascribable to differences in the duration of the illness, premorbid IQ, medication, or electroconvulsive therapy received, or prominence of any particular symptoms. The results suggest the co-existence of disordered water homeostasis and cognitive impairment in a subset of schizophrenic patients.

Risk-taking behaviour of Cape Peninsula high-school students. Part I. Introduction and methods.

In this study, risk-taking behaviour of Cape Peninsula high-school students was investigated. Suicidal behaviour, cigarette smoking, alcohol consumption, drug use, road-related behaviour, violent behaviour and sexual behaviour were included. This article, the first in a series, describes the rationale and methodology of the project. Sixteen schools were selected so as to yield a representative sample of schools in the three major education departments in the Cape Peninsula (administered by the Department of Education and Training and the Houses of Assembly and Representatives). The final sample size was 7,340 school students. A self-administered questionnaire was completed in a normal school period. Estimates for each education department were weighted to produce an overall estimate. The results are presented by standard and home language(s), and gender. Limitations of the study include its cross-sectional nature; the possibility of under- and over-reporting; the exclusion of important groups of adolescents such as absentees and dropouts, and those attending specialised and private schools; and not being able to present the results separately for each education department.

Risk-taking behaviour of Cape Peninsula high-school students. Part II. Suicidal behaviour.

The prevalence of a wide range of risk-taking behaviour among high-school students in the Cape Peninsula, South Africa, was investigated. In this article, the results for suicidal behaviour are presented. Cluster sampling techniques produced a sample of 7,340 students from 16 schools in the three major education departments. A self-administered questionnaire was completed in a normal school period. Estimates for each education department were weighted to produce an overall estimate. During the previous 12 months, 19% of students had seriously thought about harming themselves in a way that might result in their death, 12.4% had told someone that they intended to put an end to their life, and 7.8% had actually tried to put an end to their life. There were different trends according to gender, standard and language(s) spoken at home. Of those who had made a suicide attempt during the previous 12 months, 85.7% indicated that they had seriously thought about doing so, while 57.7% had told someone that they intended putting an end to their life. There is in many cases no continuity from suicidal ideation to communicating suicidal intent to an actual attempt.

Risk-taking behaviour of Cape Peninsula high-school students. Part III. Cigarette smoking.

The prevalence of a wide range of risk-taking behaviour among high-school students in the Cape Peninsula, South Africa, was investigated. In this article, the results for cigarette smoking are presented. Cluster sampling techniques produced a sample of 7,340 students from 16 schools in the three major education departments. A self-administered questionnaire was completed in a normal school period. Estimates for each education department were weighted to produce an overall estimate. Of the students 18.1% indicated that they smoked at least 1 cigarette per day. Of these, 66.9% had tried to stop. Of those who did not smoke at least 1 cigarette per day, 41.2% had smoked previously and 3.6% intended to start smoking. There were different trends according to gender, standard, and language(s) spoken at home. Of note was the small percentage of Xhosa-speaking females who smoked. There is an urgent need for smoking prevention programmes in schools.

Risk-taking behaviour of Cape Peninsula high-school students. Part V. Drug use.

The prevalence of a wide range of risk-taking behaviour among high-school students in the Cape Peninsula, South Africa, was investigated. In this article, the results for drug use are presented. Cluster sampling techniques produced a sample of 7,340 students from 16 schools in the three major education departments. A self-administered questionnaire was completed in a normal school period. Estimates for each education department were weighted to produce an overall estimate. Cannabis was the illicit drug most widely used; 7.5% had smoked cannabis, and 2.4% had done so in the previous 7 days. A small subgroup (1.6%) of students had smoked cannabis and methaqualone (Mandrax) together. Reported lifetime use of injectable drugs was 0.5%, and 10.9% had sniffed solvents, 2.6% having done so in the previous 7 days. There were different trends according to gender, standard, and language(s) spoken at home. Of particular note was the small proportion of Xhosa-speaking females who were involved with drug use. The results suggest that the majority of drug use among school students is experimental. A small number of adolescents abuse drugs and are at risk for its associated problems; intervention is indicated for this group.