Polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and related environmental compounds: biological markers of exposure and effects

Lung cancer caused by polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs and related environmental agents is a major problem in industrialized nations. The high case-fatality rate of the disease, even with the best supportive treatment, underscores the importance of primary lung cancer prevention. Development of biomarkers of exposure and effects to PAHs and related compounds is now underway and includes measurement of urinary metabolites of specific PAHs as well as detection of protein and DNA adducts as indicators of effective dose. Validation of these markers in terms of total environmental dose requires that concurrent measures of air levels and potential dermal exposure be made. In addition, the interrelationships between PAH biomarkers must be determined, particularly when levels of the marker in surrogate molecules (e.g., protein) or markers from surrogate tissues (e.g., lymphocyte DNA) are used to assess the risk to the target organ, the lung. Two approaches to biomarker studies will be reviewed in this article: the progress made using blood lymphocytes as surrogates for lung tissues and the progress made developing noninvasive markers of carcinogen-DNA adduct levels in lung-derived cells available in bronchial-alveolar lavage and in sputum. Data are presented from studies in which exfoliated urothelial cells were used as a surrogate tissue to assess exposure to human urinary bladder carcinogens in occupational groups.

A study on disabled children in a rural community in southern Thailand

This study reports the findings of a survey undertaken in 1990/1991 in a poor and predominantly Malay-Muslim community in southern Thailand. The aims were to estimate the prevalence and type of childhood disability and to examine some of the ways in which this disability can be prevented and treated. The result showed that the overall prevalence rate of child disability was 1.2%. Most disabled children were suffering from limb impairment, followed by muteness, deafness, and mental retardation. Nearly half of the children had never been treated or assessed by a modern rehabilitation service, two-thirds would be expected to gain significant improvement from assessment and appropriate referral, and one-third of the disabilities could have been prevented using the application of modern technologies. Cost, inaccessibility and strong cultural beliefs explained the failure of the children's families to bring them to the service. The study indicates several ways in which disability could be better prevented, detected or treated in rural Thailand.

Epidermal cytokinetics, DNA adducts, and dermal inflammation in the mouse skin in response to repeated benzo[a]pyrene exposures

Few studies have investigated the chronic cytokinetic effects of carcinogen exposure in the mouse skin. We report two experiments involving the repeated application of benzo[a]pyrene (BaP) to the dorsal skin of female Ha/ICR mice. In the first experiment, the cytokinetic, inflammatory, and DNA adduct responses were studied daily over a 9-day period encompassing the fourth and fifth weekly applications of BaP at doses of 16, 32, and 64 micrograms. The second experiment involved the same cytokinetic measurements at 1, 3, 5, and 8 months, and the weekly BaP doses were 4, 8, and 16 micrograms. The first study showed that after each application of 32 or 64 micrograms BaP, there was a wave of slow DNA synthesis in the epidermis which peaked at 24 hr, in coincidence with a wave of BaP-DNA adducts, followed by the appearance of dead and damaged keratinocytes. For the first few days after BaP application there was a depression in the mitotic rate which recovered several days before the next BaP application. There was a predominantly monocytic dermal inflammation throughout the observation period. In the second experiment, at the lower BaP doses, there was proliferative depression at 1 month, without dermal inflammation. With continued exposure, the proliferative depression changed to a dose-dependent increase in the rate of proliferation and dermal inflammation. The level of BaP-DNA adducts was followed in the 4 micrograms/week dose group, which showed a threefold increase after 4 months with the appearance of inflammation and heightened cell proliferation. These results suggest that the delayed inflammatory reaction, possibly based on a cell-mediated immune reaction to BaP, might have been responsible for the late cytokinetic responses and the associated increase in the level of BaP-DNA adducts.

Efficacy, safety, and immunogenicity of a meningococcal group B (15:P1.3) outer membrane protein vaccine in Iquique, Chile. Chilean National Committee for Meningococcal Disease

A meningococcal group B (15:P1.3) outer membrane protein vaccine was tested for efficacy in a randomized, double-blind controlled study in Iquique, Chile. A total of 40 811 volunteers, ages 1-21 years, enrolled in the study. Volunteers received two doses of vaccine six weeks apart by jet injector. Both the experimental vaccine and the control vaccine (Menomune, A, C, Y and W135 meningococcal polysaccharide vaccine) were well tolerated with minor side-effects. Active surveillance for suspected cases of meningococcal disease was conducted for 20 months in Iquique. Eighteen cases of group B meningococcal disease were confirmed during the 20 months. Efficacy was estimated to be 51% (p = 0.11) for all ages combined. In children aged 1-4 no protection was evident, but in volunteers aged 5-21 vaccine efficacy was 70% (p = 0.045). The IgG antibody response by ELISA was characterized by a large booster effect after the second dose, followed by a substantial drop in antibody levels by 6 months. The youngest children had the highest responses. The bactericidal antibody response, on the other hand, was characterized by the lack of a significant booster response, higher responses in the older children, and an increase in the geometric mean titer in the later months of the study in the older children.

Stability of attendance in general practice

Data on the attendances of all patients at three general practices in Western Australia for two 6-month periods 11 months apart were collected as part of a previous study. The present study examined the stability of the attendance patterns of the patients over the two study periods in terms of number of patients, number of visits and diagnoses. The patients who attended in both study periods were classified into four attendance groups: low to low; low to high; high to low; and high to high. The age, sex and diagnoses for each were compared. The results showed that whilst the patient populations remained constant over the two periods, these populations were not comprised of the same patients. Only 45% of those who attended in the first 6 months also attended in the second. Similarly, whilst 8% of patients in each study period were classified as high attenders, only 22% of the high attenders in the first period were also high attenders in the second. The long-term high attenders were older and suffered from chronic diagnoses. The short-term high attenders were found to suffer from more self-limiting diseases and conditions such as depression and pregnancy.

Situation of hypertension in some Bangkok slums

A cross-sectional epidemiologic survey was undertaken in slums in the catchment areas of two health centers in Bangkok. Two hundred and sixty representative households were randomly selected. All adults (993) aged 20 years and over who lived in the households were asked to participate. The results were, however, based on 809 subjects (89%) who responded and whose data were completed. It was found that prevalence of hypertension (blood pressure > or = 160/95 mmHg) was 14 per cent with a 95 per cent confidence interval of 11.8 and 16.4 per cent. Nearly half of the hypertensives were found to be mild cases (diastolic blood pressure = 95-105 mmHg). Less than half of the hypertensives were aware of their condition. Even a lower proportion was under treatment and had their blood pressure controlled. The results confirmed earlier studies that slum inhabitants seem to be at high risk of hypertension. Furthermore, the status of hypertensives in terms of awareness, treatment and control was unacceptably poor. This prompts a need to develop community programmes to cope with the problems.

An investigation of hypertension in a slum of Nakhon Ratchasima

There is evidence that Thai people living in slums may be at high risk of developing hypertension. The present study was undertaken on a random sample of 1,000 subjects aged 20 and over living in a slum in Muang district of Nakhon Ratchasima during 1 February to 31 may 1988. This study consisted of measurements of blood pressure and body build, with administration of an interview on demographic characteristics, sociocultural factors and food frequency patterns. The results were based on 804 respondents. It was found that the prevalence of hypertension was 16.9%, nearly half of the hypertensives being mild cases. Only a low proportion of the proven cases was both aware of their condition and receiving treatment. About one fifth of the treated cases had blood pressure under 160 mm Hg systolic and 95 mm Hg diastolic. Based on these findings, it is concluded that these slum inhabitants are at high risk of developing hypertension. Community interventions are needed in order to prevent complications related to hypertension. Health education aimed at increasing community awareness of hypertension should be a major component of the community intervention.

The effect of Orem's self-care model on nursing care in a nursing home setting

The need of the functionally disabled for nursing care is a primary rationale for institutionalization in long-term care settings. However, maintenance of the self-care abilities that nursing home residents retain is an important component of their quality of life. Nurses are in an important position to encourage and sustain residents' abilities to participate in their care. Nevertheless, without specifying the role of the resident in care, nursing interventions may inadvertently reinforce dependency and apathy at the expense of autonomy, control and well-being. Data from nursing home care records and interviews suggest that nursing staff using Orem's Self-Care Deficit Nursing Theory differ in their nursing assessments and goals of care from staff on a control unit. Further study is recommended of the influence of the model on staff perspectives of care and on interventions which support nursing home residents' self-care ability and well-being.

Morbidity coding in general practice

If research is to be of any use the phenomena being studied must be clearly defined. Almost 30 years ago the difficulty of classifying primary care problems using the International Classification of Diseases (ICD-8) was demonstrated. This led to the development of the International Classification of Health Problems in Primary Care-2-Defined which is based on ICD-9. Despite the work that has gone into the development of ICHPPC-2-Defined, relatively little work has been undertaken to assess the validity and reliability of its use. This paper describes the results of such a study conducted as a preliminary to the use of ICHPPC-2-Defined in a study of consulting patterns in general practice. The participating general practitioners were trained in the use of ICHPPC-2-Defined and then coded problems which they identified in a set of clinical vignettes. Following the coding exercise, a review session was held in which difficulties and errors in the use of ICHPPC-2-Defined were discussed. Subsequently, the general practitioners were required to code two more sets of vignettes, which included some problems repeated from the preceding sets. Comparisons were then made of changes in the validity and reliability of coding from one round to the next. The results of the study suggest that the reliability and validity of morbidity data collected using ICHPPC-2-Defined can be increased by training sessions for the coders which focus on the main sources of error in the use of ICHPPC-2-Defined.(ABSTRACT TRUNCATED AT 250 WORDS)

A clinical trial of a self-care approach to the management of chronic headache in general practice

This paper reports a trial which assessed the clinical effectiveness of adding a behavioural self-management programme to the existing management of chronic headache by general practitioners (GPs). Eighty-seven chronic headache sufferers, referred to the study by 35 GPs, were randomly allocated to either a self-care group or a GP-control group. Headaches, drug usage, visits to health-care providers and time off work were self-monitored daily by all subjects for 4 weeks prior to intervention, for 4 weeks during intervention, and for 4 weeks immediately after intervention. Additionally, self-monitoring was carried out for two further 4-week periods, one at 6 months and one at 12 months post intervention. Headache records showed that the self-care program significantly enhanced GP management. This effect was well maintained. However, drug usage, visits to health-care providers and time off work did not differ significantly between the treatment and control groups. 'No-show' rates, defined as those referred by a GP but who did not attend, were high--largely due to time requirements of the self-care program. However, drop-out rates, defined as those who left the self-care groups were low. It was concluded that this behavioural self-management program was a clinically effective adjunct to general practice management of headache but its use is likely to be limited due to problems of patient enrollment.

Sensitivity and specificity of endocervical curettage and the endocervical brush for the evaluation of the endocervical canal

A series of 87 consecutive conization specimens was studied to evaluate the accuracy of endocervical curettage for the detection of dysplasia in the endocervical canal and to investigate the role of the endocervical brush for the outpatient management of patients with atypical Papanicolaou smears. For patients having cervical intraepithelial neoplasia within the endocervical canal in conization specimens, the false-negative rate observed for endocervical curettage was 45% and the false-positive rate for the detection of endocervical involvement was 25%. The false-negative rate for the endocervical brush was only 8.4%, but the false-positive rate for endocervical involvement was 62.5%. The false-negative rate of endocervical curettage could be reduced to 16.7% if an abundant volume of endocervical material (as determined by point counting) was required. The utility of endocervical curettage to detect cervical intraepithelial neoplasia in the endocervical canal appears to be dependent on the adequacy of the specimen. The determination of adequacy is a critical factor for the proper interpretation of specimens obtained by endocervical curettage.

Cultural change, growth and feeding of children in an isolated rural region of Yemen

This paper reports a study on the growth and feeding patterns of children from an isolated region of North Yemen. Marasmus was extremely common and was associated with poor infant feeding practices--particularly the widespread use of bottled milk--and frequent infections. Despite the appearance of a homogeneous traditional society, there were significant differences in the growth of children from adjacent areas. Children from a small township serving as the administrative centre of the region grew more poorly and had a higher mortality than those from the immediate rural hinterland. While poorer living conditions and more frequent infections may explain much of the worse growth and higher mortality of the township children, it is likely less adequate patterns of feeding, particularly greater use of artificial milk, also contribute significantly to the observed difference in growth. Despite the remote rural setting of the study, feeding patterns and growth may be influenced by a number of social factors associated with 'urbanisation'.

High levels of childhood rickets in rural North Yemen

Despite a warm sunny climate, rickets is extremely common in children living in an isolated mountainous area of North Yemen. In a small township the overall prevalence amongst children under five years attending for vaccination was 27%. The condition was most common at the end of the first year and had disappeared by the fifth year. Marasmus was commonly associated with rickets. Children from the rural villages outside the township had significantly lower rates of rickets. Several factors may contribute to the very high rates of rickets in rural Yemen. However, lack of exposure to sunlight as a consequence of particular cultural practices is likely to be the most important. The major social and behavioural factors which restrict the young child access to sunlight are outlined, and possible remedies discussed.