Tuberculosis in immigrants and visitors

Immigrants and visitors are a significant factor in the epidemiology of tuberculosis (TB) in New Zealand, accounting for an increasing proportion of notifications in recent years. At present screening of immigrants from countries with a high incidence of TB is inadequate. There are deficiencies in procedures, inadequate screening coverage, ineffectual coordination between the Ministry of Health and New Zealand Immigration Service, incomplete follow-up on those at risk of TB, confusion over financial responsibility, inadequate data to describe the problems and monitor interventions, and a lack of commitment to assistance with TB control in neighbouring countries from which some of our TB arises. We make recommendations in all of these areas. Timely screening of high-risk immigrants should be seen as health protection for ethnic minorities.

Preparation of Iron Particles Coated with Silica

A method is described for coating fine iron particles ( approximately 1 µm) with a uniform silica layer, produced by the hydrolysis of tetraethyl orthosilicate. The presence of a small amount of gelatin on the surface of the iron particles facilitates this process. X-ray photoelectron measurements indicate that the gelatin interacts with the surface of the iron particles through both nitrogen (in -NH(2) groups) and oxygen (in -COOH groups) and then binds to the silica. The silica coating increases the resistance of the iron particles to oxidation on heating in air, raising the temperature at which a detectable oxidization occurs from 330 to 400 degrees C. Copyright 1999 Academic Press.

Absence of prolactin gene expression in colorectal cancer

AIMS

Previous studies documenting hyperprolactinaemia in patients with colorectal cancer have suggested that the tumour is the source of hormone production. The aim of this study was to determine the frequency of hyperprolactinaemia in patients with colorectal cancer before, during, and after surgery, and also to determine whether prolactin is produced by these tumours.

METHODS

Serum prolactin concentrations were measured in 20 patients with colorectal cancer before, during, and after surgical resection of their tumours. Samples taken during surgery included peripheral venous blood and blood taken from the main veins draining the tumour. To determine whether the tumour was responsible for the production of prolactin in these patients, paraffin wax embedded sections of tumour specimens were subjected to immunohistochemistry and western blotting using a monoclonal antibody to prolactin.

RESULTS

Five patients (three women, two men) had preoperative prolactin concentrations above the normal reference range, although this increase was of clinical importance in only two. After surgical resection of their tumours, prolactin concentrations remained high in both patients. All 20 patients had greatly raised prolactin values at the time of surgery, irrespective of whether this was measured in peripheral blood or in blood taken from veins draining the tumour. All 20 colorectal cancer tissue samples, including those with raised preoperative and/or postoperative prolactin concentrations, were negative for prolactin staining. Frozen tissue was also available in four cases. The absence of prolactin gene expression in these four tumours was confirmed both by repeat immunohistochemistry and by western blotting. A further 50 colorectal cancer cases examined by immunohistochemistry alone were also unreactive for prolactin.

CONCLUSIONS

The results of this study suggest that serum prolactin concentrations may occasionally be raised in colorectal cancer patients, but that the tumour is not the source of hormone production.

Inadequate treatment for sexually transmitted diseases in the South African private health sector

Correct management of sexually transmitted diseases (STDs) is important for their control, and to reduce HIV transmission. Guidelines on syndromic management of STDs were introduced by the provincial Department of Health in KwaZulu/Natal (KZN) in South Africa in 1995. The drug treatment provided for STDs by the 11 private general practitioners in one rural district was assessed and compared with provincial guidelines. Information was gathered through semistructured interviews which asked the 11 doctors, who all dispense prescribed drugs as part of the consultation fee, how they would treat 3 hypothetical cases of STD syndromes. In all 33 prescriptions, the treatment did not correspond exactly with provincial recommendations and only 3 (9%) were adequate. All other prescriptions were inadequate because dose or duration was incorrect in 6 (18%), or because incorrect drugs were prescribed in 24 (73%) of cases. Eight of the 11 doctors did not provide adequate treatment for any of their cases. A continuing medical education programme for the doctors and their staff was devised to improve the STD treatment in the private sector in this South African district.

The reinforcement of dentures

The material most commonly used for the fabrication of complete dentures is poly (methyl methacrylate) (PMMA). This material is not ideal in every respect and it is the combination of virtues rather than one single desirable property that accounts for its popularity and usage. Despite its popularity in satisfying aesthetic demands it is still far from ideal in fulfilling the mechanical requirements of a prosthesis. The fracture of dentures may be due to the mechanical properties of the acrylic resin or may be due to a multiplicity of factors leading to failure of the denture base material. Generally, there are three routes which have been investigated to improve the impact properties of PMMA: the search for, or development of, an alternative material to PMMA; the chemical modification of PMMA such as by the addition of a rubber graft copolymer; and the reinforcement of PMMA with other materials such as carbon fibres, glass fibres and ultra-high modulus polyethylene. The following review of attempts to improve the mechanical properties of denture base material takes account of papers published during the last 30 years.

STD syndrome packets: improving syndromic management of sexually transmitted diseases in developing countries

OBJECTIVE

To design, introduce, and evaluate "STD syndrome packets" containing recommended drugs for each syndrome, four condoms, a partner treatment card, and a patient information leaflet, with the goal of improving sexually transmitted disease (STD) case management.

METHODS

Packet design evolved around available packaging technology, informed by pilot testing with nurses working in primary care clinics, doctors in private medical practices, and patients with an STD, in Hlabisa, South Africa. Evaluation 1 year later included analysis of distribution records and interviews with 16 nurses and 64 patients.

RESULTS

A cheap packet (2 U. S. cents each, excluding contents) compatible with current legislation was designed and introduced to six public sector clinics and as a short pilot to five private medical practices. Four thousand eighty-five packets were distributed to the clinics, equivalent to approximately 115% of the STDs reported over that period. All 16 nurses reported using the packets, but only 63% did so all the time because of occasional supply problems. All believed the packets improved treatment by saving time (75%), improving supply of condoms and partner cards (44%), and making treatment easier (56%). Patients also responded positively, and most said they would buy a packet (up to $5) at a pharmacy (84%) or store (63%) if available.

CONCLUSIONS

The STD syndrome packets have the potential to improve STD syndromic management by standardizing therapy and improving the supply of condoms, partner cards, and information leaflets. Packets are popular with practitioners and patients, but consistent supply is essential for maximal impact. There may be scope for social marketing of the packets, which could further increase use.

Unrecognized sexually transmitted infections in rural South African women: a hidden epidemic

Sexually transmitted infections (STIs) are of major public health concern in developing countries, not least because they facilitate transmission of human immunodeficiency virus (HIV). The present article presents estimates of the prevalence, on any given day, of STIs among women in rural South Africa and the proportion who are asymptomatic, symptomatic but not seeking care, and symptomatic and seeking care. The following data sources from Hlabisa district were used: clinical surveillance for STI syndromes treated in health facilities, microbiological studies among women attending antenatal and family planning clinics, and a community survey. Population census provided denominator data. Adequacy of drug treatment was determined through quality of care surveys. Of 55,974 women aged 15-49 years, a total of 13,943 (24.9%) were infected on any given day with at least one of Trichomonas vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, or Treponema pallidum. Of the women investigated, 6697 (48%) were asymptomatic, 6994 (50%) were symptomatic but not seeking care, 238 (1.7%) were symptomatic and would seek care, and 14 (0.3%) were seeking care on that day. Only 9 of the 14 women (65%) were adequately treated. STIs remained untreated because either women were asymptomatic or the symptoms were not recognized and acted upon. Improved case management alone is therefore unlikely to have a major public health impact. Improving partner treatment and women's awareness of symptoms is essential, while the potential of mass STI treatment needs to be explored.

Methods used to select artificial anterior teeth for the edentulous patient: a historical overview

PURPOSE

Selecting artificial teeth for a denture is complex when there are no remaining natural teeth and no pre-extraction records. The aim of this paper is to review the methods used to select artificial anterior teeth for the endentulous individual.

MATERIALS AND METHODS

The review takes account of the majority of papers published during the last 100 years and is organized according to the methods used for determining artificial tooth form.

RESULTS

Several factors have been proposed as aids for artificial tooth selection, and numerous methods have been devised for the evaluation of reliable esthetic factors in determining artificial tooth form.

CONCLUSION

To date, no universally reliable method of determining tooth form has been found. The Williams classification (1914) is the most universally accepted method of determining anterior tooth form.

Improving quality of sexually transmitted disease case management in rural South Africa

OBJECTIVE

To measure quality of sexually transmitted disease (STD) syndromic case management and aspects of health-seeking behaviour at baseline in an intervention trial.

SETTING

Ten rural primary care clinics, Hlabisa district, South Africa.

DESIGN

Simulated patients (fieldworkers trained to present with STD syndromes) made a total of 44 clinic visits; 49 STD patients were interviewed when exiting clinics; facilities were assessed for availability of necessary equipment and drugs; 10 focus group discussions were held with staff; and STD syndrome surveillance was performed in all 10 clinics.

RESULTS

A total of 9% of simulated patients were correctly managed (given correct drugs, plus condoms and partner notification cards), recommended drug treatment was given in only 41% of visits, and appropriate counselling was given in 48% of visits. Among patients leaving the clinic, although 39% waited over an hour to be seen and only 37% were consulted in private, all reported staff attitudes as satisfactory or good. Only six clinics had syndromic management protocols available, three reported intermittent drug shortages, and seven lacked partner notification cards. Focus group discussions revealed good staff knowledge about STD, but showed lack of training in syndromic management and low morale. Surveillance data showed that while 75% of those presenting for care did so within 1 week of symptom onset, 27% had been treated for an STD in the preceding 3 months, and only 6% of those treated were contacts.

CONCLUSIONS

Quality of STD case management was poor despite good staff knowledge and availability of most essential resources. An intervention comprising staff training and STD syndrome packets has been designed to improve quality of case management.

Computer-generated study of the correlation between tooth, face, arch forms, and palatal contour

STATEMENT OF PROBLEM

Several factors have been suggested as aids for artificial tooth selection. Numerous methods have been devised for the evaluation of reliable esthetic factors in determining artificial tooth form. There is no universally accepted single esthetic factor that can be used reliably to aid artificial tooth selection.

PURPOSE

This article describes a new method incorporating a computer program to analyze four esthetic factors: form of the face, arch form, palatal contour, tooth shape, and to determine whether there was correlation between tooth, face, and arch forms and palatal contour.

MATERIAL AND METHOD

Impressions were made of the maxillary dentition of 50 dentate undergraduate dental students with irreversible hydrocolloid impression material and casts formed. A standardized photographic procedure was used to record portrait slides of each subject's face and of maxillary dental arches and central incisors made from dental casts. A comprehensive computer program was developed to correlate esthetic factors by superimposition.

RESULTS

Superimposing outline form between face, tooth, and arch showed that for tooth to face form nearly half the comparisons were dissimilar and only 22% corresponded. This is the lowest level of correspondence in this group. Highest correspondence (28%) occurred between arch to face form, followed by arch to tooth form (24%). Arch to tooth showed the lowest level of dissimilarity (32%). For correlation among the four factors across the sample group based on a comparison of classifications in each subject, men tended to dominate tapering classes, whereas women dominated square and ovoid classes.

CONCLUSION

Correspondence of outline forms through superimposition revealed an insignificant correlation between face, tooth, and arch forms. Although this method applies high technology, it does not improve the accuracy of determining shape and size of teeth in an edentulous patient. The cost and complexity of the method of measurement may also make it impractical for common application.

Strains and tensile stress distribution in loaded disc-shaped ceramic specimens. An FEA study

Disc-shaped specimens are frequently tested in order to establish an understanding of the properties of ceramic material. In this study three-dimensional finite element stress analysis has been used to investigate the loading characteristics of this shape of specimen and the effect of incorporating scratches and voids into its structure. The results indicated that stress increased as loading was carried out nearer to the centre of the specimen. The presence of cracks did not affect these stresses whereas the presence of a void resulted in a very high stress concentration.

Neural systems underlying arousal and attention. Implications for drug abuse

The monoaminergic and cholinergic systems are implicated in different forms of behavioral arousal that can be dissected in terms of their forebrain targets and the nature of the behavioral processes they modulate in distinct regions. Thus, evidence in rats with selective neurochemical manipulations tested behaviorally using an analog of an attentional task developed for human subjects indicates that the coeruleo-cortical noradrenergic system is implicated in divided and selective attention, the basal forebrain cholinergic system in stimulus detection, the mesostriatal and mesolimbic dopaminergic systems in response speed and vigor, and the mesencephalic serotoninergic or 5-HT systems in response inhibition. Our recent studies have focused on fractionating, in the same task, the differential contributions of the dorsal and median raphé 5-HT systems as well as elucidating the functions of the mesocortical dopaminergic system, each of which may be relevant to understanding the behavioral and cognitive sequelae of cocaine administration in human subjects as well as in experimental animals.

Automated fluorescence microscopic measurement of apoptosis frequency following ionizing radiation exposure in cultured mammalian cells

PURPOSE

To develop and assess an automated image cytometric method of apoptotic cell classification for use under conditions in which apoptosis is a rare event (e.g. fibroblastoid cell lines or low-dose irradiation).

METHOD

Image acquisition software was adapted to gather double-stained cell images from slides prepared using cell fixation and staining methods that emphasized apoptotic morphology. Chinese hamster ovary cells (CHO) were classified individually by discriminant analysis of morphological and nuclear texture features calculated for each image. Discriminant functions were constructed from a manually classified set of over 60000 cell images categorized as 'normal', 'apoptotic', 'cell doublets' or 'debris' and all subsequent cell images collected were classified using these functions.

RESULTS

Application of this technique resulted in a 99.8% accuracy in classification of the normal cell population, and 81.7% classification accuracy for apoptotic cells. This method was then applied to study the time course of the apoptotic response of CHO cells following X-irradiation. Following irradiation with 5 Gy no increase above control levels of apoptosis was noted until 18 h post-irradiation, which corresponded with the release of the G2 block as determined by DNA-content analysis. Apoptotic frequency increased to a peak level of 12.1 +/- 4.6% at 42 h post-irradiation.

CONCLUSIONS

Automated image cytometry provides an efficient and consistent method of apoptosis measurement. This study represents the first detailed characterization of the time course and the role of cell division in CHO cell apoptosis.

Neural Systems Underlying Arousal and Attention: Implications for Drug Abusea

The monoaminergic and cholinergic systems are implicated in different forms of behavioral arousal that can be dissected in terms of their forebrain targets and the nature of the behavioral processes they modulate in distinct regions. Thus, evidence in rats with selective neurochemical manipulations tested behaviorally using an analog of an attentional task developed for human subjects indicates that the coeruleo-cortical noradrenergic system is implicated in divided and selective attention, the basal forebrain cholinergic system in stimulus detection, the mesostriatal and mesolimbic dopaminergic systems in response speed and vigor, and the mesencephalic serotoninergic or 5-HT systems in response inhibition. Our recent studies have focused on fractionating, in the same task, the differential contributions of the dorsal and median raphé 5-HT systems as well as elucidating the functions of the mesocortical dopaminergic system, each of which may be relevant to understanding the behavioral and cognitive sequelae of cocaine administration in human subjects as well as in experimental animals.

Waiting lists. The wrong target

The numbers now waiting for treatment in the NHS are more than double what they were in 1948 despite huge increases in activity. Increased activity has not reduced the time patients wait. Mean waiting times in the 1990s were 13-14 weeks, the same as in the 1960s and 1970s. An increase in activity to reduce the numbers waiting for treatment may, in fact, increase the number being put on the waiting list. Government targets should concentrate on how long individual patients have to wait, rather than reducing the numbers on the waiting list.

The correlation between selected factors which influence dental aesthetics

This study evaluated the inter-relationship between five aesthetic factors: the form of the face, tooth and arch, maxillary anterior tooth arrangement and palatal contour. An assessment was made to determine if correlation was sufficient to recommend their use as reliable aesthetic factors for the selection of suitable tooth moulds for edentulous and partially edentulous patients. This would enable the clinician to select a tooth mould at the chairside, based on an evaluation of the individual's aesthetic factors where, for example, the maxillary incisors should have the same outline shape as the individual's face. A computer program was developed incorporating images of the factors taken from 50 Caucasian adults aged 20-31 years and assessment of correlation made by outline superimposition and classification. The objectives were to design a computer program to analyse, classify and evaluate correlation between the five factors in each case by superimposition and classification. Correlation by superimposition recorded some concurrence between forms. The findings of this study suggest that there was insufficient correlation to support Nelson's 'Aesthetic Triangle', or Williams' face form/tooth theory. The incidence of correlation by classification between anterior tooth arrangement and arch form was sufficiently high to suggest their value as an aesthetic aid.

Identification of the t complex-encoded cytoplasmic dynein light chain tctex1 in inner arm I1 supports the involvement of flagellar dyneins in meiotic drive

The cytoplasmic dynein light chain Tctex1 is a candidate for one of the distorter products involved in the non-Mendelian transmission of mouse t haplotypes. It has been unclear, however, how the t-specific mutations in this protein, which is found associated with cytoplasmic dynein in many tissues, could result in a male germ cell-specific phenotype. Here, we demonstrate that Tctex1 is not only a cytoplasmic dynein component, but is also present both in mouse sperm and Chlamydomonas flagella. Genetic and biochemical dissection of the Chlamydomonas flagellum reveal that Tctex1 is a previously undescribed component of inner dynein arm I1. Combined with the recent identification of another putative t complex distorter, Tctex2, within the outer dynein arm, these results support the hypothesis that transmission ratio distortion (meiotic drive) of mouse t haplotypes involves dysfunction of both flagellar inner and outer dynein arms but does not require the cytoplasmic isozyme.

Sexually transmitted disease syndromes in rural South Africa. Results from health facility surveillance

BACKGROUND AND OBJECTIVE

Surveillance for sexually transmitted diseases (STD) is important for priority setting, service development, and evaluating interventions.

GOAL

To conduct health facility-based surveillance for STDs to inform design of a control program and to provide baseline measures for evaluation of interventions.

STUDY DESIGN

Surveillance system for patients with STD syndromes in public and private sector health facilities in Hlabisa, South Africa.

RESULTS

Over a 5-month period, 4,781 patients with an STD were reported, 3,126 (65%) by clinics and 1,655 (35%) by general practitioners; 2,582 (54%) were in men. Most were diagnosed with a single syndrome. Discharge was most common (49% of both male and female patients), followed by ulcer (36% of men and 14% of women). Mean symptom duration was 18 days for women and 10 days for men (p < 0.0001). A quarter reported having another STD in the previous 3 months. The highest age-specific incidence was estimated at 16.4% among women 20 to 24 years of age.

CONCLUSIONS

The burden of STDs is high in rural South Africa. There is considerable scope for improved disease control, and the private sector has an important role to play.

Family planning services in developing countries: an opportunity to treat asymptomatic and unrecognised genital tract infections?

OBJECTIVE

To determine the prevalence of asymptomatic and unrecognised genital tract infections among women attending a family planning clinic in rural South Africa.

METHODS

189 consecutive women had genital samples taken to diagnose infection with Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Candida albicans, Treponema pallidum, and HIV, and to diagnose bacterial vaginosis.

RESULTS

Mean age was 25 years; 155 (82%) were unmarried, 156 (83%) were currently using contraception, and 41 (22%) reported having an STD treated in the preceding 12 months. Although none volunteered abnormal urogenital symptoms, 74 (39%) had at least one elicited by direct questioning. 119 women (63%) had at least one genital infection: N gonorrhoeae (eight; 4%), C trachomatis (14; 8%), T vaginalis (26; 14%), C albicans (56; 30%), active syphilis (15; 8%), HIV (44; 24%), and bacterial vaginosis (29; 15%). 49 women (26%) had multiple infections. Most infections (71; 60%) were asymptomatic. Symptomatic women failed to recognise and report their symptoms, and routine services failed to detect the infections.

CONCLUSION

Prevalence of genital tract infection is high among these women, most infections are asymptomatic, and symptomatic infections are frequently not recognised. Women attending family planning clinics in such settings should be screened for syphilis and offered testing for HIV infection. Strategies to detect and treat other genital infections need to be developed.

An evaluation of self-cured and visible light-cured denture base materials when used as a denture base repair material

The aim of this study was to compare some of the physical properties of a heat-cured, a self-cured and a visible light-cured acrylic resin, and to evaluate the suitability of visible light-cured resin as a repair material for dentures made of heat-cured acrylic resin. Transverse strength, surface hardness and impact strength were determined for the three materials and the efficiencies of light-cured and self-cured resins, when used as a repair material, were evaluated by testing the transverse strength of repaired heat-cured specimens 1 hour, 1 week and 1 month after repair. The results showed that the rigidity of specimens repaired with light-cured resin improved with longer water storage. However, their transverse strength reached a maximum after one day and was reduced after 1 month. The rigidity and transverse strength of specimens repaired with self-cured resin were not influenced significantly by water storage and the transverse strength was significantly higher than the light-cured repaired specimens.