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H C Walvoort

Publications and source records attributed to H C Walvoort.

At least 19 recordsLinked to original sources
PubMed2000

[Terminologia anatomica: a new reference work for anatomy].

The Nomina anatomica (6th edition in 1989) was the standard anatomical nomenclature until recently. It has been succeeded by the Terminologia anatomica (TA) by resolution of the International Federation of Associations of Anatomists in 1999. By now the TA has been published as a book and on cd-rom. The objective of the TA is to further uniformize the anatomical terminology, also internationally, and especially to democratize it, i.e. to ensure that it accommodates the needs of clinicians and medical scientists. The number of anatomical terms listed has grown to more than 7500. The increase is caused mainly by the insertion of clinical anatomical and neuro-anatomical names. A number of incorrect or misleading terms have been replaced. Each Latin term has a unique code number and is supplied with an English equivalent (International anatomical terminology; IAT) the spelling of which in either UK English or American English is considered equally correct. Based on the TA every language can formulate its own anatomical nomenclature. The nomenclature is presented per system or organ tract. An alphabetic index follows TA as well as the English IAT list. The use of eponyms is discouraged, but a list of well-known ones is appended to facilitate accessibility of older literature. Relevant suggestions about amendments are eagerly awaited and a broad basis of endorsement among the medical scientific world is hoped for. This journal will adopt the TA/IAT from now on as the work of reference regarding anatomical terms.

Anatomy↗
PubMed1999

[Duplicate publication of articles in the Dutch Journal of Medicine in 1996].

OBJECTIVE: To determine the number of undisclosed/disclosed duplicate publications of original articles (OA) in the Nederlands Tijdschrift voor Geneeskunde (NTvG). DESIGN: Retrospective bibliometric study. METHOD: All biomedical articles published in January 1994-June 1998 and written by the first or second author of the 148 OA published in 1996, were compared with the articles in the NTvG at the editorial office of the NTvG. Resemblances in the objective, study design, study population between the different articles were observed. The researchers assessed whether the same article had been published twice or more and whether this was acceptable or redundant (according to the criteria of the International Committee of Medical Journal Editors). RESULTS: In 1996 the NTvG published 30 (20%) OA which were also published elsewhere. In 23 cases (77%) the article was first published in another scientific journal and in 7 cases (23%) the article was published once again after its appearance in the NTvG. In 20 duplicate articles in the NTvG a footnote with a reference to the first publication was present. In 10 duplicate articles no such footnote could be found. In comparison with a similar study of the years 1990-1992 the number of duplicate publications was the same but the fraction of correctly disclosed duplicate publications had risen from 5/23 (22%) to 16/22 (73%) (p < 0.001).

Bibliometrics↗
PubMed1999

[Effects of articles published in the Dutch Journal of Medicine].

OBJECTIVE: To inventory the effects of publishing in the NTvG. DESIGN: Retrospective, descriptive. METHODS: The first authors of the articles of the sections Clinical lessons, Capita selecta, For practice, Original articles, Case reports and Side effects of drugs, from the issues 27-53 of Volume 138 (1994) of the NTvG were approached for a written enquiry about the effects of their articles. Reactions in the form of letters to the editor were assessed by screening the relevant section. RESULTS: The results of the enquiry concerned 165 articles. The authors of 160 articles (97%) reported that they had been approached in person with reference to the publication, on average 15.7 times orally and 2.0 times in writing. The authors of 66 articles (40%) were invited to deliver a lecture, data from 62 articles (38%) were used by others and 54 articles (33%) resulted in (continuation) research. An approach by the media followed after 23 articles (14%). A positive effect on the number of relevant patient referrals was mentioned of 4 (44%) articles from section For practice and 7 (30%) articles from section Clinical lessons. Various other effects were reported of 48 articles (29%). Forty (20%) of the total of 197 articles involved in the study were followed by one or two letters to the editor, prompted mostly by Clinical lessons (33%). CONCLUSION: Virtually all articles produced an effect. Many articles were followed by personal reactions and many articles elicited a response indicating influence on medical teaching, science or clinical activity.

Bibliometrics↗
PubMed1999

[Influence of specific clinical lessons in the Dutch Journal of Medicine on clinical management].

OBJECTIVE: To establish whether publication of an article propagating a laboratory test leads to measurable increase of the number of requests for that test. DESIGN: Retrospective. METHOD: From volume 138 (1994) of the Dutch Journal of Medicine (NTvG), three clinical lessons were selected that contained an unequivocal clinical message and a recommendation to request a specific laboratory test for particular patients. All laboratories performing the test in question were asked to report the number of requests per month in the months before, after and during publication of the article in question and during the same months of 1993. The difference between the number of requests in the period after publication of the article in 1994 and in the same period in 1993 was determined and tested postulating a Poisson distribution. RESULTS: Regarding two clinical lessons (one about determination of Coxsackie virus in neonates and one about examining arthritis patients for parvovirus B19) no significant difference in the numbers of requests before and after the publication was found, particularly also because the laboratories could not supply itemized data so that relevant information was lost in a flood of other data. The third clinical lesson (about determination of antibodies against Onchocerca in patients complaining of itching after a trip to the tropics) was followed by a significant increase of the number of requests (from 50 to 90; p < 0.001) in the 3 months following publication. CONCLUSION: Publication of a clinical lesson about a recommended laboratory test for onchocerciasis in the NTvG resulted in a significant rise of the number of requests for that test.

Family Practice↗
PubMed1998

What are the factors determining authorship and the order of the authors' names? A study among authors of the Nederlands Tijdschrift voor Geneeskunde (Dutch Journal of Medicine).

CONTEXT: Although criteria justifying authorship of scientific medical articles have been formulated, it is not well known how authorship is established in practice. OBJECTIVES: To assess the criteria for authorship used by authors of original articles in Nederlands Tijdschrift voor Geneeskunde (NTVG, the Dutch Journal of Medicine), and to determine whether the criteria for authorship of the International Committee of Medical Journal Editors (ICMJE) are known and applied. DESIGN: Survey questionnaire. SETTING: Editorial office of the NTVG. PARTICIPANTS: All 450 authors of 115 original articles published in 1995. MAIN OUTCOME MEASURES: Author's contribution to study design, material, collection of data, statistics, and writing. RESULTS: Of 362 forms returned, 352 could be analyzed (78.2% response rate). The 5 questions most frequently answered affirmatively were ICMJE criteria: critical reading (86.1 % of the authors), approval of the final version (84.7%), study design (74.7%), study conception (64.2%), and revision (63.4%). Authors rated their contribution 2 points higher than did their coauthors. Interestingly, 64% of the respondents met the ICMJE criteria, although 60% of the respondents did not know them. CONCLUSION: Authorship was mostly in accordance with ICMJE criteria although many authors were not familiar with them.

Authorship↗
PubMed1997

[Nobel Prize of Medicine 1997 awarded for prion theory].

The Nobel Prize 1997 for Medicine and Physiology was awarded to S.B. Prusiner, who proposed the prion hypothesis. Prions are small 'proteinaceous infectious particles' that lack nucleic acids and hence genetic information. Prions are normal host encoded proteins but with an abnormal tertiary structure, which makes them extremely resistant to chemical and physical inactivation that would modify nucleic acids. They 'replicate' by forcing their conformation upon the normal prion proteins. Recently it was demonstrated that the prion disease, bovine spongiform encephalopathy (BSE) can be transmitted to man in whom it causes a new variant of Creutzfeldt-Jakob disease.

Animals↗
PubMed1997

[Editing of articles accepted for publication by the Nederlands Tijdschrift voor Geneeskunde].

The Nederlands Tijdschrift voor Geneeskunde has been publishing medical science in Dutch for 140 years. To bridge the gap between the specialist science and the general medical reader several sections in the accepted papers have to be clarified, simplified and shortened by post acceptance editing. The style and language of the authors is treated with respect. Changes are made if the article does not comply with internationally accepted rules on scientific reporting, if the article can not be understood using currently authoritative general and medical books of reference, and if its language does not comply with generally accepted Dutch rules for grammar and spelling.

Netherlands↗
PubMed1997

[Medical science in the Dutch language].

Medical researchers consider a publication in English to be of a higher standard than one in a local language such as Dutch. An international publication in English is appropriate when the readers addressed belong to an international scientific community, but the mere fact that a publication is in English is no indication of its importance. Research of a national scope and of national consequences should be published in the national native language. In addition the use of the mother tongue allows deeper and more balanced thought in comparison to the use of a second language. The application of study results in clinical practice in the Netherlands is enhanced by their publication in Dutch, as is the national recognition of the research group. Finally, articles in Dutch provide all of the Dutch clinicians with the opportunity to read original scientific work and not via a (popular) translation. This contributes to science-based clinical medicine in the Netherlands.

Language↗
PubMed1996

Readers' evaluation of effect of peer review and editing on quality of articles in the Nederlands Tijdschrift voor Geneeskunde.

BACKGROUND: Academic biomedical journals use peer review and editing to help to select and improve the quality of articles. We have investigated whether articles accepted by the Nederlands Tijdschrift voor Geneeskunde, the Dutch Journal of Medicine, were improved after peer review and editing (post-acceptance scientific and copy editing). METHODS: 400 readers of the journal (100 each of medical students, recent medical graduates, general practitioners, and specialists) were invited to participate in a questionnaire survey. The first 25 from each group who agreed to participate were included. We posted a pack containing a set of identically appearing typescripts (ie, blinding) of the submitted, accepted, and published versions of 50 articles that had been published in Ned Tijdschr Geneeskd. Each evaluator received two of the sets of versions, and each set was evaluated by one person from each group. The package also included two questionnaires: the first was used to compare the submitted with the accepted version (25 questions), the second compared the accepted with the published version (17 questions). The questions were answered on five-point scales, and were about the quality of the articles or were general/overall scores. We analysed the data as scores of 3-5 (ie, improvement) versus 1-2. FINDINGS: After peer review, the quality in 14 of 23 questions (61%) was significantly improved (p = 0.03 or smaller). In particular, the overall score and general medical value were significantly improved (p = 0.00001 for each). Editing led to significant improvement in 11 of 16 questions (69%, p = 0.017 or smaller), and especially in style and readability (p = 0.001 and p = 0.004). Generally, we found no differences between the scores of the four categories of evaluators. 72% of the evaluators correctly identified which version was which. INTERPRETATION: Evaluations by readers of the Ned Tijdschr Geneeskd indicated significant improvement of published articles after both peer review and editing. We think that peer review and editing are worthwhile tasks. We also think that possible biases would have had a negligible effect on our results (including the fact that we selected the first 25 evaluators who responded, that some evaluators may have read the published version, and that one questionnaire may have looked more scientific than the other, more editorial one).

Attitude of Health Personnel↗
PubMed1994

Colonization and antibody response in mice and rats experimentally infected with Pasteurellaceae from different rodent species.

Mice and rats were experimentally infected with Pasteurellaceae isolated from mice, rats, hamsters and gerbils. Mice and rats were most heavily colonized by strains originally isolated from mice and rats respectively, and to a lesser extent by Pasteurellaceae from hamsters and gerbils. Colonization was generally accompanied by seroconversion. Gross pathology of the lungs was not observed. We conclude that Pasteurellaceae-free SPF mice and rats can be colonized by members of this bacterial family present in other rodent species.

Animals↗
PubMed1993

[Neospora caninum as a cause of lameness symptoms in young dogs].

At the age of three weeks, two Labrador retriever puppies, out of a litter of nine, suffered from diarrhoea and muscular weakness. One puppy died within two days. The other was killed after a tetraparalysis had developed. Two weeks later a third puppy was killed because of a paretic hind leg. At the age of five months another dog had to be euthanized because of progressive hind limb ataxia. Pathological examination revealed polyradiculoneuritis, multifocal encephalomyelitis and polymyositis. In the lesions, particularly in the nerve roots, free and clustered protozoal tachyzoites were found. In the central nervous system tissue cysts were seen. By use of immunohistochemistry the protozoal organisms were identified as Neospora caninum, a newly recognized protozoan in the dog. Fresh bovine heart, that had been fed to the puppies, is regarded as the possible source of infection.

Animals↗
PubMed1992

Construction and analysis of Bordetella pertussis mutants defective in the production of fimbriae.

Although the role of fimbriae in bacterial disease has been well established, little is known about the function of Bordetella pertussis fimbriae. To study this function, well-defined fimbrial mutants were constructed. B. pertussis harbours three fimbrial genes, fim2, fim3 and fimX, and strains were constructed in which one or more fimbrial genes were inactivated by means of gene replacement. Analysis of these strains by means of immunoblotting suggested the presence of a fourth fimbrial gene, tentatively designated fimY. A fimbrial mutant was analysed in a mouse respiratory infection model, together with a strain harbouring a deletion in the gene for the filamentous haemagglutinin. Both mutants were affected in their ability to persist in the trachea. Persistence in the nasopharynx was only affected by the mutation in the filamentous haemagglutinin gene. Neither the filamentous haemagglutinin nor the fimbrial mutants were affected in their ability to persist in the lung. Our results suggest that the filamentous haemagglutinin plays a more crucial role than fimbriae in the colonization of the upper respiratory tract of the mouse.

Animals↗
PubMed1992

Histological changes in the orbital region of rats after orbital puncture.

To contribute to the assessment of the degree of discomfort in rats after orbital puncture, we have examined the histological changes in the intraorbital tissues caused by this technique of blood sampling. Orbits were studied from rats euthanized either within 1 min, 4 days, 28 days or 56 days after puncture while under diethyl-ether anaesthesia. The techniques of 2 animal technicians were compared, one using a broken haematocrit capillary and the other using an intact Pasteur's pipette. Non-punctured orbits served as controls. Microscopic slides containing the eye in situ at 2 horizontal levels in the orbital region were examined for 37 parameters; the slides were scored blind and in random order. Orbital puncture caused haemorrhages in the puncture track and, depending on the technique used, also in the periosteum. Four days after puncture, inflammatory reactions were present in the puncture track. Depending on the technique of puncture, these reactions were also seen in the eye muscles and periosteum or in the Harderian gland. Within 4 weeks after puncture, the lesions had healed without detectable scars. The different histological effects of the 2 techniques of orbital puncture are discussed in the light of the characteristics of these techniques.

Animals↗
PubMed1990

Acellular and whole cell pertussis vaccines protect against the lethal effects of intracerebral challenge by two different T-cell dependent humoral routes.

Athymic (nu/nu) and euthymic (+/nu) BALB/c mice were immunized with a whole cell pertussis vaccine or with an acellular vaccine which contained detoxified pertussis toxin (PT) and filamentous hemagglutinin (FHA). Only the euthymic mice were protected against intracerebral challenge with virulent Bordetella pertussis which implies involvement of T-cells. As a cell transfer from mice immunized with whole cell or acellular vaccine prior to the challenge did not protect naive euthymic recipients, cellular immunity seems to be non-protective as an effector mechanism. Mice could be protected passively against a challenge by administration of immune sera. Therefore, T-cell dependent humoral immune responses to B. pertussis appear to be crucial for protection. The humoral response was further studied with athymic and euthymic mice. In euthymic mice the whole cell vaccine induced antibodies to FHA, pililipopolysaccharides (LPS) and an outer membrane protein (OMP) preparation, whereas the acellular vaccine induced antibodies to PT, FHA and OMP. Both IgM and IgG could be detected. From the nude mice only those immunized with the whole cell vaccine showed an antibody response which consisted of low titres of IgM directed to LPS. Sera from both +/nu and nu/nu mice immunized with the whole cell vaccine were bactericidal in vitro. These data demonstrate that in the mouse model protection to intracerebral challenge with B. pertussis is T-cell dependent as is the humoral response to PT, FHA, OMP and pili. The T-independent B-cell activation by the whole cell preparation is due to the presence of LPS.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Seroreactivity of patients with Crohn's disease with lymph nodes of primed nude mice is independent of the tissue used for priming.

Athymic nude mice, injected with a cell-free filtrate of intestinal tissue from patients with Crohn's disease, have been shown to express antigens in their lymph nodes to which sera from patients with Crohn's disease contain antibodies. In the present study, immune reactivity was assessed with a histochemical indirect immunoperoxidase assay on paraplast-embedded tissue sections. The reactive lymph node cells were identified as sinus macrophages. We confirmed earlier findings of immunofluorescence studies that the reaction showed some antibody specificity, the proportion of patients with Crohn's disease who were positive (84%) being higher than of patients with ulcerative colitis (29%). However, reactivity of Crohn's disease sera was found to be antigen nonspecific, as it was equally observed with lymph nodes of mice primed with saline or with homogenates from patients with ulcerative colitis, diverticulitis, or volvulus. Hence, this nude mouse model does not seem appropriate to identify a transmissible etiology of Crohn's disease.

Animals↗