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H de Vries

Publications and source records attributed to H de Vries.

At least 19 recordsLinked to original sources
PubMed1997

Differential and cell development-dependent localization of myelin mRNAs in oligodendrocytes.

In oligodendrocytes (OLG), the mRNAs for the various myelin proteins localize to different intracellular sites. Whereas the confinement of myelin basic protein (MBP) mRNA to the processes of the cell has been well established, we demonstrate that most other myelin mRNA species are mainly present in the perinuclear region. Using in situ hybridization of cultured rat OLG we found that mRNAs are localized to at least three different locations: 1) to the perinuclear region [myelin-associated glycoprotein (MAG) mRNA]; 2) mainly to the processes (the mRNA for the 14-kDa isoform of MBP); and 3) to both the perinuclear region and the primary processes [2',3'-cyclic nucleotide phosphodiesterase (CNPase) and proteolipid protein (PLP) mRNAs]. Thus, depending on their primary structure, the mRNA species in OLG either remain near the nucleus or localize to primary or secondary processes before their translation. The myelin mRNA localization correlates well with that of the proteins encoded in them, as demonstrated by immunocytochemistry. Since different isoforms of MBP have different locations in transfected HeLa cells (Staugaitis et al.: J Cell Biol 110:1719-1727, 1990), we also have investigated the localization of the various mRNAs in OLG, using exon 2-minus and exon 2-specific probes in situ hybridization. The exon 2-minus MBP mRNAs are transported far into the processes, whereas exon 2-specific mRNA was only detected in the cell body. This suggests that sorting and trafficking of MBP mRNA are regulated by the presence or absence of the exon 2 sequence. Furthermore, during maturation of OLG, exon 2-plus mRNAs disappear, whereas exon 2-minus mRNAs increase. The developmentally regulated expression of exon 2-plus transcripts suggest a role of their protein products in differentiation rather than in myelination.

Animals↗
PubMed1997

Carotid artery stenosis is related to blood glucose level in an elderly Caucasian population: the Hoorn Study.

Cross-sectional associations between carotid artery stenosis (CAS) on the one hand, and parameters of glycaemia and specific insulin levels on the other, were investigated in an age, sex, and glucose tolerance stratified random sample from a 50-74-year-old Caucasian population. Subjects treated with insulin or oral hypoglycaemic agents were classified as having known diabetes mellitus (KDM) (n = 66). Using two oral glucose tolerance tests, and based on the World Health Organisation criteria, all other participants were classified as having a normal (NGT) (n = 287), an impaired (IGT) (n = 169) or a diabetic (NDM) (n = 106) glucose tolerance. CAS was defined haemodynamically using duplex scanning. The crude prevalences of only moderate (16-49%) CAS were 6.6%, 7.1%, 5.7% and 12.1% in NGT, IGT, NDM and KDM subjects, respectively. For any severe (> or = 50%) CAS, crude prevalences were 2.8%, 4.7%, 9.4% and 7.6%. The prevalence of any severe CAS was higher in NDM (p < 0.01) and KDM subjects (p = 0.07) than in NGT subjects. The prevalence of a history of stroke or transient ischaemic attack was 1.7%, 1.8%, 2.8% and 1.5% in NGT, IGT, NDM and KDM, respectively. In univariate logistic regression analysis, HbA1c, serum fructosamine, fasting and 2-h post-load glucose were significantly associated with any severe CAS. In multivariate analyses controlling for other risk factors, only HbA1c and 2-h post-load plasma glucose remained significantly associated (odds ratios: 1.29 per % and 1.09 per mmol/l, respectively) in separate models. No association could be shown between either fasting or 2-h post-load specific insulin and any severe CAS in either univariate or multivariate analyses. In conclusion, HbA1c and 2-h post-load plasma glucose are independently associated with any severe CAS, whereas specific insulin is not.

Aged↗
PubMed1996

Intra-individual variation of glucose, specific insulin and proinsulin concentrations measured by two oral glucose tolerance tests in a general Caucasian population: the Hoorn Study.

We studied the intra-individual variation in plasma glucose, specific serum insulin and serum proinsulin concentrations, measured by two 75-g oral glucose tolerance tests in an age, sex, and glucose tolerance stratified random sample from a 50-74-year-old Caucasian population without a history of diabetes mellitus. The intra-individual variation was assessed by the standard deviation of the test-retest differences (SDdif). For subjects with normal (n = 246), impaired glucose tolerance (n = 198), and newly detected diabetes (n = 80) classified at the first test, the following (SDdif/median level of individual average scores) were found: fasting glucose: 0.4/5.4, 0.5/5.9 and 0.7/7.2 mmol/l; 2-h glucose: 1.3/5.6, 1.8/8.5 and 2.3/12.8 mmol/l; fasting insulin: 23/76, 32/89 and 30/116 pmol/l; 2-h insulin: 190/303, 278/553 and 304/626 pmol/l; fasting proinsulin: 4/8, 6/13 and 9/18 pmol/l; 2-h proinsulin: 19/49, 23/84 and 33/90 pmol/l, respectively. In both glucose, proinsulin and insulin concentrations the total intra-individual variation was predominantly determined by biological variation, whereas analytical variation made only a minor contribution. The SDdif can easily be interpreted, as 95% of the random test-retest differences will be less than 2.SDdif, or in terms of percentage, less than (2.SDdif/median level of individual average score) 100. Therefore, for subjects with normal glucose tolerance, 95% of the random test-retest differences will be less than 15% (fasting glucose), 46% (2-h glucose), 61% (fasting insulin), 125% (2-h insulin), 100% (fasting proinsulin) and 78% (2-h proinsulin) of the median value of the individual average scores. No substantial independent association of either age, gender or obesity with the intra-individual variation in glucose, proinsulin, or insulin concentrations was found.

Anthropometry↗
PubMed1996

Pros and cons of quitting, self-efficacy, and the stages of change in smoking cessation.

In The Netherlands, 34% of the population smoke, and 70% of these smokers are not planning to quit. The lower percentages in the U.S. population seem to reflect a difference in smoking culture. This study analyzes the pros and cons of quitting and self-efficacy expectation in the 5 stages of change in the Dutch population. The results are compared with the pattern of the pros and cons of smoking and self-efficacy expectations found in U.S. samples. The data show the hypothesized pattern: In the first 2 stages, the expected positive outcomes of quitting discriminated better between the stages than self-efficacy, whereas for later stages, self-efficacy was the better discriminator. This study shows that the stage typology is applicable to the Dutch population and that the pattern of the pros, cons, and self-efficacy is very similar to the pattern found in the U.S. populations.

Adult↗
PubMed1996

Annoyance from environmental tobacco smoke and support for no-smoking policies at eight large Dutch workplaces.

OBJECTIVE: To collect descriptive data on annoyance from environmental tobacco smoke (ETS), attitudes toward smoking at the workplace, and support for a no-smoking policy. DESIGN: Survey of eight large companies in four sectors of Dutch industry. SUBJECTS: A representative sample of smoking and non-smoking employees (n = 1480). RESULTS: Thirty-five per cent of non-smoking employees felt it was "annoying" to "very annoying" when their colleagues smoked during worktime, and 78% thought a smoky work environment was harmful to their health. About two-thirds of non-smokers "sometimes" to "often" experienced annoyance from ETS at their workplace. The individual solution approach (no explicit policy) is not only rejected by most nonsmokers but also by many smokers. In three sectors of industry, there was much support among employees for a smoking ban except for work areas designated for smoking. CONCLUSIONS: These results could encourage more companies to implement smoking restrictions and they may be used as reference data by companies wanting to develop effective no-smoking policies.

Adult↗
PubMed1995

[Treatment of septic arthritis of the hand using temporary intermittent immobilization with an external fixator].

OBJECTIVE: To evaluate the treatment of a bacterial infection of a finger joint with incision, drainage and intermittent immobilization using external fixation apparatus. DESIGN: Retrospective, descriptive. SETTING: Department of Surgery, St Elisabeth Hospital, Tilburg. METHOD: In eight males and two females (median age 37 years) with acute bacterial arthritis of a finger joint, this joint was opened surgically, washed out and then immobilized using mini-external fixation equipment, for about 3 weeks. The fixator was unscrewed daily so that the patient could move the finger in water, with the purpose of mechanical cleansing of the joint; the intermittent pressure that occurs in the cartilage during movement is supposed to promote the removal of debris. Subsequently, the finger was fixed in alternating positions to prevent adhesions. Mean duration of follow-up was 48 months (11-78). RESULTS: Arthrodesis had to be carried out in one patient because of persistent arthritis and tissue necrosis, while in one other, part of the finger was amputated. The other eight patients showed good final results, without symptoms. CONCLUSION: In bacterial arthritis of a finger joint, temporary intermittent immobilization using external fixation equipment is certainly worth consideration.

Adult↗
PubMed1995

Evaluation of a Dutch community-based smoking cessation intervention.

BACKGROUND: Until 1990, smoking cessation interventions in the Netherlands were limited. The utility and effectiveness of community-based smoking cessation programs have not been examined. METHODS: In a treatment city (Den Bosch) a multicomponent community-based smoking cessation intervention was implemented in which local mass media and general practitioners draw smokers' attention to a local quit line. Telephone counselors advised applicants on their choice between self-help and group treatment and optional telephone counseling. Another Dutch city (Apeldoorn) served as a control. Population samples of smokers (n = 547 and n = 546) were interviewed three times at approximately 7-month intervals. Self-help manual requesters (n = 84) and group participants (n = 83) were interviewed before and 6 months after treatment. RESULTS: Treatment modalities were successful; 13% of self-help manual requesters and 22% of group participants were abstinent after 6 months. On a population level the intervention resulted in significantly higher recall of self-help manual and group program in the treatment city. A modest intervention effect on prevalence of abstinence was found at the community level. CONCLUSIONS: Treatment modalities were effective within their participants, but the intervention effectiveness on a community level was limited. No significant difference was found between quit rates after 14 months (7% in treatment city and 9% in control city). Several system failures could be identified. However, probably the intervention effect was seriously confounded by two national governmental publicity campaigns introducing and reinforcing a mandatory smoking ban and a series of national campaigns initiated by the united Dutch tobacco producers opposing the ban.

Adult↗
PubMed1995

Peripheral arterial disease in relation to glycaemic level in an elderly Caucasian population: the Hoorn study.

We investigated the cross-sectional association between peripheral arterial disease and glycaemic level in an age, sex, and glucose tolerance stratified random sample from a 50-74-year-old Caucasian population. Subjects treated with oral hypoglycaemic agents or insulin were classified as having known diabetes mellitus (KDM) (n = 67). Using two oral glucose tolerance tests, and based on World Health Organisation criteria, all other participants were categorized as having a normal (NGT) (n = 288), an impaired (IGT) (n = 170), or a diabetic (NDM) (n = 106) glucose tolerance. Prevalence rates of ankle-brachial pressure index less than 0.90 were 7.0%, 9.5%, 15.1% and 20.9% in NGT, IGT, NDM and KDM subjects, respectively (chi-square test for linear trend: p < 0.01). Prevalence rates of any peripheral arterial disease (ankle-brachial pressure index < 0.90, at least one monophasic or absent Doppler flow curve or vascular surgery) were 18.1%, 22.4%, 29.2% and 41.8% in these categories (chi-square test for linear trend: p < 0.0001). The prevalence of any peripheral arterial disease was higher in KDM and NDM than in NGT (p < 0.03, p < 0.0001, respectively), whereas no statistically significant difference was demonstrated between IGT and NGT. The same applied when using the ankle-brachial pressure index criterion. Logistic regression analyses showed that any arterial disease was significantly associated with HbA1c, fasting and 2-h post-load plasma glucose after correction for cardiovascular risk factors (odds ratios and 95% confidence intervals 1.35; 1.10-1.65 per %, 1.20; 1.06-1.36 and 1.06; 1.01-1.12 per mmol/l, respectively), whereas it was not associated with fasting and 2-h post-load specific insulin. Ankle-brachial pressure indices were not associated with either plasma glucose parameters or insulin in univariate or multivariate analyses. In conclusion, parameters of glucose tolerance are independently associated with any peripheral arterial disease, whereas insulin is not.

Aged↗
PubMed1995

Socio-economic differences in smoking: Dutch adolescents' beliefs and behaviour.

Smoking behaviour is more frequent among those who have a low than those who have a high socio-economic status. The present study confirms that this is also true for Dutch adolescents. The purpose of this study was to investigate whether adolescents with a low socio-economic status (LSES) have different motives for smoking or non-smoking than those with a high socio-economic status (HSES), the aim being to formulate more specific recommendations for prevention strategies for the various groups. HSES adolescents perceived a stronger association between smoking and a number of health-related, personal and social disadvantages, while linking smoking more clearly with the discovery of the taste and with relief from boredom than LSES adolescents. LSES adolescents viewed smoking as a way of meeting people. HSES adolescents experienced less positive norms and less social pressure towards smoking than did LSES adolescents. Smoking among LSES adolescents seems to be embedded in the social culture, and has a stronger social function. Smoking prevention programmes for this group will have to be integrated into a broader, community-based approach, which should also pay attention to the smoking behaviour of the social environment in general and that of the parents in particular. Finally, improved legislation with regard to smoking prevention will be required, in order to facilitate the adoption and implementation of smoking prevention programmes.

Adolescent↗
PubMed1995

Hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the skin and its UV protecting activity (an in vivo study with the rat).

Vitamin E acetate is often used rather than vitamin E as an ingredient of skin care products and dermatological preparations, because it lacks the free phenolic OH group. However, because of this the acetate as such is biologically inactive. In spite of this intrinsic inactivity, the skin is protected against the harmful effects of sunlight after topical application of vitamin E acetate. Therefore it is supposed that hydrolysis takes place in the skin and that the reaction product, the radical scavenger vitamin E, is responsible for the protection observed. In this in vivo study with the rat, we have investigated the hydrolysis of RRR-alpha-tocopheryl acetate (vitamin E acetate) in the epidermis in relation to UV radiation protection. (As a measure of protection, we used the UV-induced binding of 8-methoxypsoralen to epidermal biomacromolecules.) After a period of 5 h from a single application of vitamin E acetate, hydrolysis into free vitamin E was not observed. No protection was found at this time point, corresponding with the absence of vitamin E. After treatment for 5 days, consisting of one topical application daily, the percentage of acetate present in the stratum corneum which was hydrolysed into free vitamin E was less than 1%, whereas the corresponding value for the viable layer of the epidermis was about 5%. The hydrolysis of vitamin E acetate in the epidermis proceeded very slowly. As a result, the absolute amount of free vitamin E, found in the total epidermis after treatment for 5 days with the acetate, was only a few times higher than the normal level. Yet, this very small amount of free vitamin E proved to be sufficient for maximal protection in this animal model. The results show that vitamin E acetate acts as a prodrug, which very slowly releases minute amounts of active vitamin E.

Animals↗
PubMed1995

Prevalence and determinants of glucose intolerance in a Dutch caucasian population. The Hoorn Study.

OBJECTIVE: To study the prevalence and determinants of glucose intolerance in a general Caucasian population. RESEARCH DESIGN AND METHODS: A random sample of 50- to 74-year old Caucasians (n = 2,484) underwent oral glucose tolerance tests. Multiple regression analyses were performed to study the association of 2-h postload plasma glucose values with potential determinants. RESULTS: Prevalence of known and newly detected diabetes and impaired glucose tolerance was 3.6, 4.8, and 10.3%, respectively. In women, but not in men, the association of body mass index with 2-h glucose was fully accounted for by the waist-to-hip ratio. Maternal history of diabetes was twice as prevalent as paternal history, but paternal history only was associated with 2-h glucose. In addition, paternal history was a stronger determinant in men than in women. An independent positive association with 2-h plasma glucose was found for alcohol use of > 30 g/day in women and for intake of total protein, animal protein, and polyunsaturated fatty acids in men. An independent inverse association with 2-h plasma glucose was demonstrated for height (both sexes), alcohol use of < or = 30 g/day (both sexes), energy intake (in men), and, unexpectedly, current smoking (in men). CONCLUSIONS: The prevalence of diabetes in elderly Caucasians was 8.3%. In men, dietary habits may unfavorably influence glucose tolerance independent of obesity.

Age Factors↗
PubMed1994

Self-efficacy as an important determinant of quitting among pregnant women who smoke: the phi-pattern.

BACKGROUND: The transtheoretical model and a revised model of planned behavior were used to study the motives of pregnant women to quit or to continue smoking. The goal was to explore possibilities for tailored advice based on the motivational stage of pregnant women. METHODS: A cross-sectional study included 103 pregnant women who smoked and 40 women who had quit during the last year. Five groups were formed: precontemplators, contemplators, actors, maintainers, and relapsers. Attitudes, social influences, self-efficacy, intention, and behavior were measured. RESULTS: Precontemplators had a more negative attitude toward quitting than the other groups. Actors encountered more positive social influences for quitting. Actors and maintainers had greater self-efficacy than precontemplators and contemplators. Maintainers had greater self-efficacy than actors. CONCLUSION: Health education for pregnant women who smoke can be tailored toward their motivational stage. Precontemplators need information on the consequences of smoking and quitting for themselves and their baby to create a positive attitude. Contemplators and relapsers need information on coping with barriers that prevent them from quitting, in order to create greater self-efficacy. Post-delivery relapse prevention strategies are needed.

Adaptation, Psychological↗
PubMed1994

Results of the Dutch community project "Healthy Bergeyk".

BACKGROUND: This article reports on the results of a community health project that was implemented in the Dutch municipality of Bergeyk. The major goal was to reduce four cancer-related risk behaviors: smoking, high fat consumption, excessive alcohol use, and exposure to artificial sunlight. A control community received no new intervention. Intervention methods included mass media messages, self-help materials, small group activities, lectures, and structural activities. Community organization principles such as a social network approach, community participation, and intersectoral cooperation were applied in the project. METHODS: Data were collected from both communities among cohort research samples on three occasions using telephone interviews. RESULTS: The results indicate a significant reduction in fat intake in the experimental community. No other significant behavioral effects were found. Further analysis among respondents in the experimental condition showed that those personally exposed to the project as indicated by familiarity with and discussion about the project, had a greater decrease in fat consumption between baseline survey and second post-test than those who were not. Also, the percentage of smokers who quit between baseline survey and second post-test was greater among those who knew about the project than among those who did not. Finally, discriminant analysis was used to further examine the determinants of project exposure. Community involvement, marital status, education, and sex were related to project exposure. CONCLUSIONS: It is concluded that with the time limitations of the project in mind, the findings are encouraging.

Adult↗
PubMed1994

An ethological study on behavioural differences between hyperactive, aggressive, combined hyperactive/aggressive and control children.

Frequencies and sequential patterns of behaviour elements in pure hyperactive (N = 12), pure aggressive (N = 13), combined hyperactive/aggressive (N = 15) and control children (N = 10) were recorded in a semistructured playroom session and subsequently compared. The samples were age- and IQ-matched. In an overall MANOVA a significant main effect for hyperactivity but not for aggression was found. The hyperactive children were characterized particularly by differences in squirming and changes in sitting. The sequential patterning of their behaviour revealed weaker temporal contingencies between their behaviour and the conversational speech of the experimenter than in the case of the nonhyperactive (aggressive and control) children. This may be explained by deficits in social attention in the hyperactive groups.

Aggression↗
PubMed1994

Photoreactivity of chloramphenicol in vitro and in vivo.

The negative side effects of chloramphenicol (CAP) mostly involve blood dyscrasias (e.g. irreversible non-dose-dependent aplastic anemia), allergic skin reactions and eye damage. To learn the cause of these side effects, most research focuses on metabolically formed nitroso- and hydroxylamino derivatives in the predisposed patient. In previous investigations it was demonstrated that photochemical decomposition of CAP in vitro by UV-A leads to formation of p-nitrobenzaldehyde (pNB), p-nitrobenzoic acid (pNBA) and p-nitrosobenzoic acid (pNOBA); the latter comprises up to 45 mol% of the starting amount of CAP. Incubation of these photoproducts in rat blood showed that pNB and pNOBA rapidly react and that PNBA is stable under these conditions. Reaction products from pNB (half-life 1.7 min) proved to be pNBA and p-nitrobenzyl alcohol (pNBOH) while pNOBA (half-life 3.7 min) was converted into p-aminobenzoic acid (pABA). Exposure of CAP in rat blood to UV-A yielded the same end products: pNBA, pABA and pNBOH. To estimate the amount of oxidative stress generated in vivo by these compounds, the ability to form methemoglobin (MetHb) in erythrocytes was tested; only pNOBA and p-hydroxylaminobenzoic acid (pHABA), a possible intermediate in the decomposition of pNOBA, proved to be reactive. Ultraviolet-A exposure of rats, after intraperitoneal injection of CAP, led to 3.6 times the basic level of MetHb. In addition, covalent binding of 3H-labeled CAP photoproducts to the skin of the back and to the ears was found, which was 9.1 and 3.2 times higher, respectively, than the dark values.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Outstations of the Golgi complex are present in the processes of cultured rat oligodendrocytes.

Primary cultures of rat oligodendrocytes were incubated with a fluorescent sphingolipid precursor, 6-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]hexanoylceramide+ ++ (C6-NBD-ceramide). This compound is known to stain the Golgi complex specifically. Within 30 min of incubation at 37 degrees C most of the C6-NBD-ceramide was incorporated into the perinuclear Golgi system, as revealed by conventional and confocal laser fluorescence microscopy. Interestingly, C6-NBD-ceramide was found to accumulate also in smaller, oval-shaped structures in many of the processes, at distances up to 30 microns from the nucleus. This implies the possibility that these structures are Golgi (-derived) complexes. Indeed, after incubation of oligodendrocytes with C6-NBD-ceramide and rhodamine-labeled transferrin both fluorescent labels colocalized in the Golgi system of the cell body as well as in the structures in the processes. Additional support for the Golgi character of these structures was obtained by transmission electron microscopy. Particularly in oligodendrocytes cocultured with neurons, many Golgi structures were present all over the processes. The results lead us to conclude that, in the oligodendrocyte, the Golgi complex does not only reside in the perikaryon, but also in the processes. One can speculate that a polarized biosynthetic activity, involving the presence of the Golgi near the site of myelin synthesis, may be advantageous to the oligodendrocyte for assembly and/or repair of the myelin membrane at the distal end of the processes.

4-Chloro-7-nitrobenzofurazan↗