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H L Hoeksema

Publications and source records attributed to H L Hoeksema.

12 recordsLinked to original sources
PubMed2004

[A national prospective trial register for randomised controlled trials: ethical and practical necessity].

The decision to treat a patient is often based on the results of randomised controlled trials (RCTs). These important investigations inform physicians and patients with regard to the chance of favourable results of treatment and the risks of adverse reactions. However, research has shown that especially the smaller RCTs in which no or even an adverse effect of new interventions is found run a relatively high risk of remaining unpublished, which leads to publication bias and an overestimate of the efficacy of an intervention. This is undesirable. The best way to identify possible publication bias and reduce its negative effects is to register RCTs from their starting date onwards in a prospective and publicly accessible register. Other motives for such a register are the prevention of duplication of research work and its financial support, and informing patients. Currently, a prospective Dutch national trial register is being developed by the Dutch Cochrane Centre. This is not only of importance to researchers and patients, but also to grant-providing bodies and the editors of medical scientific journals.

Humans↗
PubMed2003

[A case of fraud in a neurological pharmaceutical clinical trial].

This paper describes the laborious and lengthy path to clarification and disclosure in a case of fraud in a neurological pharmaceutical clinical trial in the Netherlands. A Dutch neurologist was suspected of irregularities within the context of the 'European stroke prevention study 2' (ESPS-2), a multicentre study into medicinal prophylaxis in patients who had suffered a stroke. The Netherlands Society of Neurology (NVN) established an independent inquiry committee for further investigation of the case. The identity of 425 of the 438 patients (97%) included in the trial by the neurologist could be retrieved. The majority of these patients were known to the neurologist with cerebral infarct. For a sample of 115 patients, the general practitioners (GPs) were contacted by means of a questionnaire. Ninety percent of the responding GPs were unaware of their patients' participation in the pharmaceutical clinical trial. A total of forty patients were asked by their GP about participation: 36 (90%; 95%-CI: 76-97) indicated that they had not participated in the trial, and 4 could not remember. The committee concluded that the neurologist had committed fraud, in the sense that he had used the names of existing patients without these patients actually being enrolled in the study. The report of the independent committee was not made public; the committee and the NVN board differed in opinion on the interpretation and implications of the agreements regarding this subject. Following prolonged legal action, the regional Disciplinary Board suspended the neurologist from practice for one year and the court of law sentenced him to 180 days imprisonment or a fee of 130,000 Euro. Based on the experience gained from this case, recommendations in case of suspicion of fraud are discussed, such as the timely appointment of an independent inquiry committee and the establishment of unambiguous agreements regarding the disclosure of the results of the investigation. Possible legal implications should be considered in advance by the organisations involved; statutes should provide regulations for procedural rules. In the Netherlands there now exists a National Body for Scientific Integrity and a committee for the Scientific Integrity of Healthcare Research to prevent scientific misconduct and to stimulate reporting and appropriate handling of this problem.

Clinical Trials as Topic↗
PubMed2001

[Research proposals submitted to the Dutch Investigative Medicine Fund; evaluation of the scientific quality by the Council for Scientific Research (NWO)].

The Council for Medical and Health Research (MW-NWO) assessed the scientific quality of research proposals submitted to the Dutch Investigative Medicine Fund, and analysed if there had been changes over time in the proportion of proposals which the MW-NWO advised to reject, the role of reports of external reviewers and the most important methodological flaws. In the period 1995-1999 'reject' had been advised for an average of 50% of the proposals, with a tendency to a smaller proportion in recent years. In nearly half of the proposals the judgements of external reviewers were not in agreement with each other. There was only a weak correlation between the judgements of the reviewers and the final advice of NWO. Among the most important flaws mentioned in the NWO advice were: efficacy not proven (a prerequisite for the Fund), proposed study not needed to solve the policy problem and methodological flaws, e.g. design and power calculation not adequate, deficiencies of inclusion and exclusion criteria.

Foundations↗
PubMed1994

Prevalence of depressive symptoms and depressive disorder in primary care patients over 65 years of age.

The aim of this study was to estimate the prevalence of depressive symptoms and depressive disorder (ICHPPC-2-defined) in patients over 65 years of age. A cross-sectional, partly two-phased, study was performed in general practices in The Netherlands. A total of 384 consecutive patients aged 65 and above, 116 men and 268 women were included, both during practice visits and home visits. Depressive symptoms were recorded with the Zung Self-rating Depression Scale, the Geriatric Depression Scale, and with physician ratings. Assessments of depressive disorder were based on an adaptation of interview ratings with the Montgomery Asberg Depression Rating Scale. The proportion of patients considered to have depressive symptoms ranged from 11 to 29% of patients, depending on the self-report instrument and the cut-off point. According to interviews a depressive disorder was estimated to be present in 17%. The high prevalence of depressive symptoms and depressive disorder suggest a higher index of suspicion of depression in elderly general practice patients.

Aged↗
PubMed1993

The value of laboratory tests for the screening and recognition of alcohol abuse in primary care patients.

BACKGROUND: Although alcohol abuse is prevalent in family practice, the diagnosis is not easily established. Laboratory tests are usually heavily relied on in the diagnostic process. METHODS: The value of laboratory tests for the screening and recognition of problem drinking in family practice is summarized, based on a review of the literature. A distinction is made between studies in selected populations of drinkers and studies in nonselected populations, ie, family practice. RESULTS: The most sensitive laboratory tests associated with excessive alcohol intake include gamma-glutamyl transferase (GGT), mean corpuscular volume, and the ratio of alanine aminotransferase to aspartate aminotransferase. No single laboratory test or combination of tests is shown to be appropriate for screening. The positive predictive value for GGT is only about 25% in a population that has a 10% prevalence of problem drinking and increases to about 55% in a population that has a 30% prevalence of problem drinking. CONCLUSIONS: Guidelines for the recognition of problem drinking in family practice should include elevated laboratory test values as one of the "alerting factors" for problem drinking, and not as a confirmation of a suspicion of problem drinking. In monitoring treatment response, GGT may be a powerful patient-motivating factor.

Alanine Transaminase↗
PubMed1979

Assignment of structural beta-galactosidase loci to human chromosomes 3 and 22.

Hybrid cell lines isolated after fusions between Chinese hamster E36 cells and normal human white blood cells were analyzed for human beta-galactosidase isoenzymes and for human chromosomes, especially 3, 12, and 22, the candidates for bearing a beta-galactosidase locus. Results of neuraminidase treatment of the cell lysates and immunological studies showed that in man two structural beta-galactosidase loci are present and can be assigned to chromosomes 3 and 22. No correlation was found between the expression of human beta-galactosidase and the presence of human chromosome 12.

Animals↗
PubMed1977

Characterization of residual hexosaminidase activity in Sandhoff's disease using man-Chinese hamster cell hybrids.

To obtain information about the nature of the residual hexosaminidase activity in Sandhoff's disease, hybrid cell lines between fibroblasts from a patient with Sandhoff's disease and Chinese hamster cells were isolated. In these hybrid cell lines, a heteropolymeric isoenzyme was detected that is composed of human alpha- and Chinese hamster hexosaminidase subunits. Due to the electrophoretic and immunological behavior of the heteropolymeric molecules in interspecies hybrids with normal fibroblasts and with cells from a patient with Sandhoff's disease, we conclude that Sandhoff cells contain an alpha-subunit of hexosaminidase with normal characteristics.

Animals↗
PubMed1977

Regional localization of a beta-galactosidase locus on human chromosome 22.

Human white blood cells with an X/22 translocation [46, XX, t(X;22)(q23;q13)] were fused with Chinese hamster cells. The isolated hybrids were analyzed for human chromosomes and 21 enzyme markers. An electrophoretic technique for studying the beta-galactosidase isoenzymes in man-Chinese hamster hybrid cells was developed. Immunological studies showed that the beta-galactosidase marker studied in these hybrids did contain immunological determinants of human origin. Furthermore the results provided evidence that a locus for beta-galactosidase is situated on chromosome 22 distal to the breakpoint in q13.

Antigen-Antibody Reactions↗
PubMed1977

Characterization of beta-D-N-acetylhexosaminidase isoenzymes in man-Chinese hamster somatic cell hybrids.

A series of man-Chinese hamster hybrids were investigated with the use of an anti-Chinese hamster hexosaminidase serum, a specific anti-human hex A serum and an anti-human hex B serum. The expression of human hex A was found to be dependent on the presence of hex B. A heteropolymeric molecule is formed independently of hex B, which consists of Chinese hamster and specific hex A moieties. It has an electrophoretic mobility nearly identical to hex A. A relationship between the absence and presence of the heteropolymeric molecule, mannosephosphate isomerase (MPI), and pyruvate kinase (PK-3), assigned to chromosome 15, was established. With respect to the two locus subunit model, the gene coding for the alpha subunit, specific for hex A, has been localized on chromosome 15.

Acetylglucosaminidase↗