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Biomedical subjects

A Bosman

Publications and source records attributed to A Bosman.

At least 19 recordsLinked to original sources

Breast cancer and post-menopausal hormone therapy.

From the introduction of post-menopausal hormone replacement therapy (HRT) there has been great concern that HRT could possibly increase the risk of breast cancer. Prolonged exposure to endogenous oestrogens undeniably increases the risk of breast cancer. Questions that are important and until now only partly answered, are the following. Are oestrogens tumour promoters, as they induce mitosis, lead to proliferation and, therefore, accelerated growth of clinically occult pre-existing tumours? In addition to this, are they genotoxic mutagenic carcinogens, or could they initiate tumours by way of accumulation of incessant DNA-replication damage mechanism? Opinions vary as to the effect of the addition of a progestogen. There is a multitude of different progestogens which could bind with differing affinity to progesterone receptor PR-A or PR-B, and which have different physiological functions via differential gene regulation. The action of a progestogen on the oestrogen-induced cellular mitotic activity could be synergistic or antagonistic (by different pathways: oestrogen receptor downregulation, activating of metabolic pathways within the breast or stimulation of apoptosis)? Over 60 observational studies and two randomized trials provide evidence that the small but significant increase in risk appears with long-term current post-menopausal hormone use. The addition of a progestogen does not decrease the risk as seen with oestrogens alone and might increase the risk further. It is not clear whether there is a difference in risk with sequentially combined versus continuously combined HRT. Many questions nevertheless still remain. Is the risk increase limited to lean women only? What about risk-modifying factors such as alcohol use and a positive family history for breast cancer? Are tumours detected under HRT less aggressive, is there a better prognosis and is the mortality not increased while morbidity is? And is HRT contraindicated for women with a positive family history for breast cancer or in those women who have been treated for breast cancer? And finally, are there alternative options for these women?

Breast Neoplasms↗

Investigation of an unexplained skin disorder in a prison clinic in the Netherlands in 2002.

An unexplained outbreak of skin disorder with itching papules or pustules occurred among drugs body packers in a detention clinic in the Netherlands in October-November 2002. The descriptive cohort study suggests this outbreak could be associated with an expired batch of disposable linens, with an overall attack rate of 30% in the study population (n=118). No additionnal cases have been noted since this expired batch was replaced.

Abdomen↗

Surveillance of HCV infection in the Netherlands.

Two surveillance systems exist in the Netherlands to monitor hepatitis C (HCV) infections. Aggregated weekly laboratory data have been available since 1990. In 1999, HCV infection became a notifiable disease. Data showed the number of reported cases has remained stable. Male cases predominated (66%), mainly between age 15 to 54. Injecting drug use was the main route of transmission (64%). Despite its added value, the notifiable system should include more clinical data to better scrutinize future changes in transmission patterns.

Adolescent↗

Evaluation of two PCR-based procedures for typing Clostridium perfringens.

Two polymerase chain reaction (PCR)-based procedures for typing Clostridium, perfringens, which affects most domestic animals, were compared and evaluated for efficiency as substitute to the guinea-pig intradermal test routinely used in our laboratory, namely a multiplex PCR and a protocol based on the individual amplification of gene sequences specific for each toxin. Reference isolates of C. perfringens types A, B, C and D as well as cultures from clinical specimens were tested. The sensitivity and specificity of the PCR was confirmed on reference isolates. There was similarity in results on 43 of the 46 samples typed by all 3 methods. Clear results were obtained by PCR on 5 clinical samples that showed either equivocal or weak skin reactions in guinea-pigs. The multiplex PCR protocol, in combination with the evaluation of bacterial growth, is a better alternative to in vivo toxin typing, since C. perfringens can only be incriminated as cause of a disease when it is present in large numbers in the intestine.

Animals↗

The community-based malaria control programme in Tigray, northern Ethiopia. A review of programme set-up, activities, outcomes and impact.

Tigray, the northernmost state of Ethiopia, has a population of 3.5 million, 86% rural, and 56% living in malarious areas. In 1992 a Community-Based Malaria Control Programme was established to provide region-wide and sustained access to early diagnosis and treatment of malaria at the village level. 735 volunteer community health workers (CHWs) serve 2,327 villages with a population of 1.74 million, treating an average of 489,378 patients yearly from 1994 to 1997. Recognition of clinical malaria is similar for CHWs and health staff at clinics where there is no access to microscopy. In 1996 a pilot community-financing scheme of insecticide-treated bednets was well accepted, but re-impregnation rates fell in 1998 because of war-related social upheaval. Indicators from health institutions show a progressive increase in malaria morbidity from 1994 to 1998. Repeated mortality surveys show a 40% reduction in death rates in under-5 children from 1994 to 1996 and a 10% increase from 1996 to 1998. These trends may be related to increased malaria transmission with water resources development, increased seasonal labour migration to malarious lowlands, prolongation of the transmission season with climate changes, and increasing chloroquine resistance throughout Ethiopia. Progressive extension of CHW services to ensure better coverage of women, children, migrant workers and communities near water development projects, change to first-line treatment with sulfadoxine-pyrimethamine, extension of the impregnated bednet initiative, and development of a regional warning system for epidemics should result in a greater impact on morbidity and mortality.

Age Factors↗

[Syphilis in addicted pregnant women: better care through more awareness and contract between organizations involved].

Three women, aged 21, 20 and 30 years, were cocaine users and pregnant. There had been no prenatal monitoring until they reported with uterine contractions. Blood of the first two women was then tested; serology revealed active syphilis infections: their children had died in utero. The blood of the third woman had been tested as part of a street project; it revealed an active syphilitic infection but she could not be found for treatment. After delivery, the child showed withdrawal symptoms. The first and third women and the child of the third woman were treated with benzylpenicillin. The system for screening and treating drug-addicted pregnant women should be intensified.

Adult↗

[Increase of early syphilis in Rotterdam (1995-1997): more (addicted) prostitutes and their clients].

OBJECTIVE: To detect risk groups in an increase of early (infectious) syphilis. DESIGN: Retrospective study of patient records. METHOD: Data from visitors with an early syphilis were collected from their respective medical records in the outpatient clinic for sexually transmitted diseases (STD) of the Academic Hospital Rotterdam-Dijkzigt, the Netherlands, over the years 1993-1997. In particular, data on risk behaviour and risk groups were collected. To obtain an indication of the (possible) causes of the increase in the number of visitors with early syphilis, (shifts in) characteristics of this population over the years were compared. RESULTS: 195 patients with early syphilis had visited the outpatient clinic, 130 males and 65 females, mean ages ranging from 30.9 (1993) to 38.1 years (1997). Most infected persons (68%) came to the outpatient clinic because of symptoms. The number of women who came to the outpatient clinic through partner notification increased considerably, from an average of 5% in 1993-1995 to 36% in 1996. Over the years a relative increase of (drug addicted) prostitutes and their clients was observed (1993-1995: 39%; 1996: 56%). CONCLUSION: The cause of the increase, or failure to decrease, of the number of syphilis-infected visitors in the STD outpatient clinic of the Academic Hospital Rotterdam-Dijkzigt should probably be sought among (drug addicted) prostitutes and their visitors.

Adult↗

[Increase of early syphilis in a red light district in Rotterdam (1995-1997) and preventive treatment].

The number of cases of syphilis in Rotterdam has increased dramatically since 1995. The prevalence of early syphilis in 1997 was highest among street prostitutes (16%). Some prostitutes could not be reached for further evaluation and treatment, probably due to their addiction to hard drugs. Prophylactic treatment for syphilis was given to most street prostitutes in a cruising zone during a screening programme for sexually transmitted diseases (STD) in January 1997. Since then, STD checkups were performed regularly in the cruising zone. The prevalence of early syphilis in the cruising zone dropped to 1.3% in 1998. The total number of reported cases of syphilis in Rotterdam also decreased sharply in 1998.

Adult↗

[Two patients with acute hepatitis B from the same piercing salon].

Hepatitis B was diagnosed in two homosexual men aged 41 and 31 years. Both had undergone piercing on the same day in the same saloon. The word piercing means application of decorations in the skin which is pierced for the purpose. The breeching of the skin combined with the conditions under which this is performed leads to a risk of transmission of especially viral infections. An assumed connection between the patients was supported by the results of molecular-biological examination of the hepatitis B virus isolates. The piercings were applied with the same pair of pincers, which was not sterilized in between. In view of these findings hygienic measures were taken in the piercing saloon in question to prevent future transmission of infections. Piercing entails health risks that are not always recognized either by those who do it or by those who have it done.

Acute Disease↗

[Screening policy for travellers from Rotterdam for hepatitis A antibodies prior to eventual immunization: favourable cost-benefit ratio].

OBJECTIVE: To evaluate costs and benefits of the screening and immunisation policy for hepatitis A virus (HAV) infection among travellers from Rotterdam. DESIGN: Descriptive and cost-benefit analysis. METHOD: From the data of the Municipal Health Service Rotterdam (GGD), the Netherlands, the details were collected on individuals travelling frequently to HAV endemic countries, who were born before 1950, or had lived for more than 10 years in an HAV endemic country or had ever suffered jaundice. Persons to whom these criteria applied were screened for HAV antibodies at the GGD before immunisation for HAV in the period January 1st 1996-June 30th 1998. Screening and vaccination policies were compared with a cost analysis. RESULTS: Antibodies against HAV were found in 79% of 1466 screened people. The lowest prevalence of antibodies was found among Dutch nationals (67%). A significantly higher prevalence was found amongst individuals from Turkey/Morocco (96%) and from the Cape-Verde Islands (97%). In the cost analysis the break even point, the prevalence level of HAV antibodies in the population at which screening cost as much as blind prophylaxis, lay for passive immunisation between 69% and 93%. For active immunisation this point lay around 17%. CONCLUSION: The selection criteria for prevaccination screening are effective in identifying individuals with a high probability of being immune against HAV infections. The current screening policy for antibodies against HAV is cost effective.

Cost-Benefit Analysis↗

Outbreak of hepatitis A in Rotterdam associated with visits to 'darkrooms' in gay bars.

An unexpectedly large number of hepatitis A virus (HAV) infections were notified among homosexual men in Rotterdam in the first five months of 1998. A case control study was conducted to investigate the hypothesis that this outbreak was associated with sexual practices and to collect information with which to focus preventive activities. Notified cases and controls selected from male members of a gay sports club completed anonymous questionnaires about known risk factors for HAV infection and sexual behaviour. Single variable analysis showed that HAV infection was associated with sexual contact with anonymous sex partners (odds ratio (OR) 4.6; 95% confidence interval (CI) 1.0-23.2) and with visits to 'darkrooms' in gay bars (OR 6.2; 95% CI 1.5-26.8). A negative association with travel abroad to western countries was observed (OR 0.4; 95% CI 0.1-1.3). The associations with visits to darkrooms (OR = 9.2; 95% CI 1.6-52.4) and travel abroad to western countries (OR 0.1; 95% CI 0.02-0.9) remained significant in a multivariable logistic regression analysis. This risk group was targeted for health education and vaccination and darkroom owners were advised to provide hygiene facilities.

Adult↗

Opportunities, problems and perspectives for malaria control in sub-Saharan Africa.

Environments conducive to high malaria transmission and widespread poverty are at the roots of the 'malaria giant', which affects 46 countries in Africa. The recent interest in and momentum of work on malaria, in endemic countries and the international community, is unprecedented and opens new perspectives for controlling the disease. Significant steps included: (i) the allocation of US$20 million by WHO for accelerated implementation of malaria control in 34 African countries in 1997-98; (ii) the Declaration on Malaria by the Heads of States of the Organization of African Unity and the establishment of the African Initiative for Malaria Control in 1997; (iii) the concomitant mobilisation of the research community in the Multilateral Initiative on Malaria; (iv) the G8 Summit in 1998 in Birmingham asking for higher commitment to malaria control, particularly in Africa; and (v) the Roll Back Malaria initiative set as a WHO priority project in 1998. However, experiences have proved the alarming 'resilience' of the malaria system in Africa, showing devastating consequences when malaria returns to the original levels after intensive control is interrupted. Effective malaria control in Africa requires long-term action, firmly rooted in the social development of the country.

Africa South of the Sahara↗

Community-based malaria control in Tigray, northern Ethiopia.

Community-based control activities have been a major component of the Tigray regional malaria control programme since 1992. A team of 735 volunteer community health workers treat on average 60,000 clinical malaria cases monthly during the high malaria transmission season. Ensuring access for the rural population to early diagnosis and treatment has contributed to a significant decrease in death rate in under-five children at the village level from 1994 to 1996. Mapping and geographic information system (GIS) technologies have been introduced to support planning for control by assessment of community-based coverage. With further development, GIS will be used in stratification, and to assess the impact of water resources development on malaria transmission and intensity.

Adult↗

Implementation of malaria control.

Global trends of infant and child mortality have decreased over the last 30 years, while the proportion of malaria deaths has progressively increased due to the deteriorating situation in sub-Saharan Africa. The Global Malaria Control Strategy promoted by WHO has encountered several obstacles to its implementation. Early diagnosis and prompt treatment can reduce malaria mortality, but there is still low investment on safe and effective modalities of care delivery at the periphery, where most of the malaria burden exists. Selective vector control (indoor residual spraying and insecticide-treated nets) plays a significant role outside Africa, but its wider use is limited by cost/affordability problems and operational issues (supply, delivery and logistics). Alternative methods such as environmental management and biological control are cost-effective only under very specific epidemiological situations. In most countries forecasting, early detection and containment of malaria epidemics is deficient, and there is separation between the research and control communities, particularly in Africa. Involvement of the internal agencies, strategic investments in capacity building and institutional networking are needed to strengthen capacity for malaria and research in the countries. The major responsibility is to guide the expenditure made by the communities (which far out-weigh the limited share of national health budgets) towards the most cost-effective approaches to reduce malaria mortality and morbidity.

Child, Preschool↗

Thrombospondin related adhesive protein (TRAP), a potential malaria vaccine candidate.

We have investigated whether naturally induced immunity to Plasmodium falciparum thrombospondin related adhesive protein contributes to protection against malaria in humans. We have carried out a case control study in children living in an endemic region of West Africa to reveal associations between PfTRAP seroprevalence and the risk of cerebral malaria. Sera collected from the case and control groups were analysed by ELISA to compare their serum reactivity against PfTRAP, the circumsporozoite protein and the merozoite surface protein 1. Children with uncomplicated malaria had a significantly higher PfTRAP seroprevalence when compared to children with cerebral malaria. The risk of developing cerebral malaria appeared to depend on the reciprocal relationship between sporozoite inoculation rates and humoral immunity against PfTRAP. Our results suggest that naturally induced humoral immunity against PfTRAP contributes to the development of protection against severe malaria. Experimentally induced immunity against TRAP in different rodent models has consistently proven to elicit a high degree of protection against malaria. This together with the functional properties of TRAP and data describing CD4 and CD8 epitopes for PfTRAP indicate that this molecule could increase the protective efficiency of available sporozoite malaria vaccines.

Africa, Western↗