Frederik A de Wolff | Universiteit Leiden (original) (raw)
Papers by Frederik A de Wolff
Organohalogen compounds, 2002
Side effects of drugs annual, 1994
Side Effects of Drugs Annual, 2002
Occupational and Environmental Medicine, 1991
Pharmaceutisch Weekblad Scientific Edition, 1985
Archives of Toxicology, 1961
ZusammenfassungErstmalige Beobachtung einer tödlichen Vergiftung durch Trinken von handelsübliche... more ZusammenfassungErstmalige Beobachtung einer tödlichen Vergiftung durch Trinken von handelsüblicher konzentrierter C4-Lösung bei einem 2jährigen Klein kind. Exitus nach 10–15 min unter den klinischen Zeichen einer Erstickung infolge curareähnlicher Wirkung. Pathologisch-anatomischer Befund unspezifisch.
British Journal of Clinical Pharmacology, Apr 1, 1982
1 Several 8-methoxypsoralen (8-MOP) preparations are now available for photochemotherapy of psori... more 1 Several 8-methoxypsoralen (8-MOP) preparations are now available for photochemotherapy of psoriasis. To assess differences in clinical response two preparations marketed in The Netherlands, Oxsoralen capsules (Elder) and Meladinine tablets (Basotherm), were given to eight psoriatic patients. Serum concentrations and the minimal phototoxic dose (MPD) as a measure for clinical response were determined. 2 Bioavailability and serum peak concentrations were significantly higher for Maladinine in all patients and the MPD value favoured Maladinine in 5 of the 8 patients. The mean time of the serum peak concentrations was 1 h earlier for Maladinine than for Oxsoralen. 3 These findings are relevant not only for the choice of drug in individual patients but also for comparison of the results of multicentre trials performed in different parts of the world.
Geburtshilfe Und Frauenheilkunde, Sep 1, 2008
Side effects of drugs annual, 2000
Occupational and Environmental Medicine, 2000
Pharmaceutisch Weekblad Scientific Edition, 1984
Abstracts of Papers. In: Histoire Épistémologie Langage, tome 6, fascicule 1, 1984. Logique et gr... more Abstracts of Papers. In: Histoire Épistémologie Langage, tome 6, fascicule 1, 1984. Logique et grammaire, sous la direction de Suzanne Bachelard . pp. 127-129
Side effects of drugs annual, 2007
CRC Press eBooks, Jul 26, 2023
Chapter 27 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 27 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp. 439-454
CRC Press eBooks, Jul 26, 2023
Chapter 28 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 28 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp. 455-460
Clinical Neuropharmacology, Aug 1, 1988
Side effects of drugs annual, 2001
Side Effects of Drugs Annual, 1999
Pharmaceutisch Weekblad Scientific Edition, 1983
Pharmaceutisch Weekblad, 1987
s of papers NEGLIGIBLE S~B~INGUAL ABSORPTION OF NIF~IPINE IN MAN. _ . . . . . . . z J.van Harten ... more s of papers NEGLIGIBLE S~B~INGUAL ABSORPTION OF NIF~IPINE IN MAN. _ . . . . . . . z J.van Harten 'i' J.Burggraaf , M.Danhof , P.van Bl~m~nelen ~ _ ~ _ ~ ............................................ Subllngual administration of nifedipine has become common medical practice . in the treatment of cardiovascular emergencies. However, since pharmacokinetic evidence was poor, the rate and extent of subllngual absorption were studied and compared to a control situation in which a capsule was bitten and swallowed. ii Young, healthy subjects participated in the study. They kept the contents of a capsule of nifedipine (lOmg) in the mouth for 20 mini and subsequently they emptied and rinsed the mouth. 86 + IIZ of the dose could be recollected unabsorbed. Maximal plasma levels of nlfediplne were only" I0 ~ 4 ng/ml, and were reached after 50 ~ 25 mln. It could be calculated that approx, i0 Z of nifedipine appeared in the systemic circulation after sublingual dosing. After biting the capsule and swallowing its contents, high maximal plasma levels (82 ~ 31 ng/ml) were obtained very rapidly (after 28 ~ 12 min). Relative systemic availability of subllngual nifediplne as compared to swallowed nifediplne was 18 ~ 6%. We conclude that, contrary to prevailing belief, sublingual absorption of nifedlpine is negligible. In cardiovascular emergencies the patient should be instructed to bite a capsule and to swallow its contents with water. Icenter for Bio-Pharmaceutical Sciences, Div.of ~ harmacology Dept.of Nephrology, University Hospital, University of Leiden, Leiden, The Netherlands. THE INFLUENCE OF CAFFEINE ON THE POSTPRANDIAL BLOOD PRESSURE FALL IN ELDERLY SUBJECTS J.W.M. Lenders, g. Morre and Th. Thien A postprandial blood pressure fall has been reported in both normotensive and hypertensive elderly subjects. Aim of the study: In a double blind placebo controlled study we investigated the effects of caffeine pretreatment on blood pressure (BP) and heart rate (HR) before and after a standardized breakfast (405 kcal) in 15 healthy volunteers aged over 65 years (mean 75.4• years). Methods: All studies were done in the fasting state after abstaining from methylxanthine containing products for at least 24 hours, and in sitting position. After 30 min. of rest, basal values of BP and HR were obtained. Then, a capsule containing either placebo (PL) or caffeine (C) (250 mg) was ingested 60 mln. before breakfast and BP and HR were recorded at regular intervals during 50 min. before breakfast and during 45 min. after breakfast. Results: Before breakfast, MAP (mean arterial pressure) did not change after pl~cebo but increased after caffeine pretreatment by 12.5%. After breakfast, MAP decreased by 6.1% below its~asal value after placebo but after caffeine the MAP did not decrease below its basal value. Conclusion: Administration of caffeine before breakfast in the elderly does not prevent or attenuate the fall of the postprandial blood pressure but because of the preprandial pressor effect of caffeine, blood pressure does not decline below its basal value. Dept. of Medicine, Die. of General Internal Medicine, St. Radboud University Hospital, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Vol . 9 I987 Pharmaceutisch Weekblad Scientific Edition 335 IMPORTANCE OF ALPHA-ADRENOCEPTORS IN THE HUMAN KIDNEY : STUDIES WITH ANTAGONISTS P.W.de Leeuw, P.N.van KS, R.de Bos and W.E.BirkenhaRer To determine the role of slpha-adrenoceptors in the regulation of renin release, we infused either the alpha-I antagonist doxazoslne (n=12) or the alpha-2 antagonist yohimbine (n=15) into the renal artery of hypertensive patients just prior to angiography. For comparison, a control group received only saline (n=12). In a first series of.experiments doses had been determined that did not affect systemic blood pressure. Before and at the end of the infusions, which lasted 15 minutes, blood was sampled simultaneously from the ipsilateral renal artery and vein for assay of active renin, while renal flow was measured with xenon-133. Renin secretion rates were calculated as the gradient of renln across the kidney times flow. In the control group renln secretion did not change and also doxazoslne (I pg/kg.min) had no effect. On the other hand, yohlmblne ( 3 ~g/kg.mln) increased renin release from 555_+85 to 1820+--220 U/mln (p~0.00l). This was in part due to an increase in flow, but also to a rise in the ven~ arterial concentration gradient for renin. Even when flow did net change, renin secretion rose. In the doxazosine group only minor changes in flow occurred. In none of the experiments did blood pressure change. In six patients the concurrent infusion of the alpha-2 agonist B-HT 933 blunted the rise in secretion evoked by yohimbine alone. It is concluded that alpha-2 adrenoceptors in the kidney play an important role In the regulation of renin release (end also in the regulation of renal flow). Alpha-I adrenoceptors seem to be less significant. HIGH DOSE…
Organohalogen compounds, 2002
Side effects of drugs annual, 1994
Side Effects of Drugs Annual, 2002
Occupational and Environmental Medicine, 1991
Pharmaceutisch Weekblad Scientific Edition, 1985
Archives of Toxicology, 1961
ZusammenfassungErstmalige Beobachtung einer tödlichen Vergiftung durch Trinken von handelsübliche... more ZusammenfassungErstmalige Beobachtung einer tödlichen Vergiftung durch Trinken von handelsüblicher konzentrierter C4-Lösung bei einem 2jährigen Klein kind. Exitus nach 10–15 min unter den klinischen Zeichen einer Erstickung infolge curareähnlicher Wirkung. Pathologisch-anatomischer Befund unspezifisch.
British Journal of Clinical Pharmacology, Apr 1, 1982
1 Several 8-methoxypsoralen (8-MOP) preparations are now available for photochemotherapy of psori... more 1 Several 8-methoxypsoralen (8-MOP) preparations are now available for photochemotherapy of psoriasis. To assess differences in clinical response two preparations marketed in The Netherlands, Oxsoralen capsules (Elder) and Meladinine tablets (Basotherm), were given to eight psoriatic patients. Serum concentrations and the minimal phototoxic dose (MPD) as a measure for clinical response were determined. 2 Bioavailability and serum peak concentrations were significantly higher for Maladinine in all patients and the MPD value favoured Maladinine in 5 of the 8 patients. The mean time of the serum peak concentrations was 1 h earlier for Maladinine than for Oxsoralen. 3 These findings are relevant not only for the choice of drug in individual patients but also for comparison of the results of multicentre trials performed in different parts of the world.
Geburtshilfe Und Frauenheilkunde, Sep 1, 2008
Side effects of drugs annual, 2000
Occupational and Environmental Medicine, 2000
Pharmaceutisch Weekblad Scientific Edition, 1984
Abstracts of Papers. In: Histoire Épistémologie Langage, tome 6, fascicule 1, 1984. Logique et gr... more Abstracts of Papers. In: Histoire Épistémologie Langage, tome 6, fascicule 1, 1984. Logique et grammaire, sous la direction de Suzanne Bachelard . pp. 127-129
Side effects of drugs annual, 2007
CRC Press eBooks, Jul 26, 2023
Chapter 27 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 27 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp. 439-454
CRC Press eBooks, Jul 26, 2023
Chapter 28 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 28 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp. 455-460
Clinical Neuropharmacology, Aug 1, 1988
Side effects of drugs annual, 2001
Side Effects of Drugs Annual, 1999
Pharmaceutisch Weekblad Scientific Edition, 1983
Pharmaceutisch Weekblad, 1987
s of papers NEGLIGIBLE S~B~INGUAL ABSORPTION OF NIF~IPINE IN MAN. _ . . . . . . . z J.van Harten ... more s of papers NEGLIGIBLE S~B~INGUAL ABSORPTION OF NIF~IPINE IN MAN. _ . . . . . . . z J.van Harten 'i' J.Burggraaf , M.Danhof , P.van Bl~m~nelen ~ _ ~ _ ~ ............................................ Subllngual administration of nifedipine has become common medical practice . in the treatment of cardiovascular emergencies. However, since pharmacokinetic evidence was poor, the rate and extent of subllngual absorption were studied and compared to a control situation in which a capsule was bitten and swallowed. ii Young, healthy subjects participated in the study. They kept the contents of a capsule of nifedipine (lOmg) in the mouth for 20 mini and subsequently they emptied and rinsed the mouth. 86 + IIZ of the dose could be recollected unabsorbed. Maximal plasma levels of nlfediplne were only" I0 ~ 4 ng/ml, and were reached after 50 ~ 25 mln. It could be calculated that approx, i0 Z of nifedipine appeared in the systemic circulation after sublingual dosing. After biting the capsule and swallowing its contents, high maximal plasma levels (82 ~ 31 ng/ml) were obtained very rapidly (after 28 ~ 12 min). Relative systemic availability of subllngual nifediplne as compared to swallowed nifediplne was 18 ~ 6%. We conclude that, contrary to prevailing belief, sublingual absorption of nifedlpine is negligible. In cardiovascular emergencies the patient should be instructed to bite a capsule and to swallow its contents with water. Icenter for Bio-Pharmaceutical Sciences, Div.of ~ harmacology Dept.of Nephrology, University Hospital, University of Leiden, Leiden, The Netherlands. THE INFLUENCE OF CAFFEINE ON THE POSTPRANDIAL BLOOD PRESSURE FALL IN ELDERLY SUBJECTS J.W.M. Lenders, g. Morre and Th. Thien A postprandial blood pressure fall has been reported in both normotensive and hypertensive elderly subjects. Aim of the study: In a double blind placebo controlled study we investigated the effects of caffeine pretreatment on blood pressure (BP) and heart rate (HR) before and after a standardized breakfast (405 kcal) in 15 healthy volunteers aged over 65 years (mean 75.4• years). Methods: All studies were done in the fasting state after abstaining from methylxanthine containing products for at least 24 hours, and in sitting position. After 30 min. of rest, basal values of BP and HR were obtained. Then, a capsule containing either placebo (PL) or caffeine (C) (250 mg) was ingested 60 mln. before breakfast and BP and HR were recorded at regular intervals during 50 min. before breakfast and during 45 min. after breakfast. Results: Before breakfast, MAP (mean arterial pressure) did not change after pl~cebo but increased after caffeine pretreatment by 12.5%. After breakfast, MAP decreased by 6.1% below its~asal value after placebo but after caffeine the MAP did not decrease below its basal value. Conclusion: Administration of caffeine before breakfast in the elderly does not prevent or attenuate the fall of the postprandial blood pressure but because of the preprandial pressor effect of caffeine, blood pressure does not decline below its basal value. Dept. of Medicine, Die. of General Internal Medicine, St. Radboud University Hospital, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Vol . 9 I987 Pharmaceutisch Weekblad Scientific Edition 335 IMPORTANCE OF ALPHA-ADRENOCEPTORS IN THE HUMAN KIDNEY : STUDIES WITH ANTAGONISTS P.W.de Leeuw, P.N.van KS, R.de Bos and W.E.BirkenhaRer To determine the role of slpha-adrenoceptors in the regulation of renin release, we infused either the alpha-I antagonist doxazoslne (n=12) or the alpha-2 antagonist yohimbine (n=15) into the renal artery of hypertensive patients just prior to angiography. For comparison, a control group received only saline (n=12). In a first series of.experiments doses had been determined that did not affect systemic blood pressure. Before and at the end of the infusions, which lasted 15 minutes, blood was sampled simultaneously from the ipsilateral renal artery and vein for assay of active renin, while renal flow was measured with xenon-133. Renin secretion rates were calculated as the gradient of renln across the kidney times flow. In the control group renln secretion did not change and also doxazoslne (I pg/kg.min) had no effect. On the other hand, yohlmblne ( 3 ~g/kg.mln) increased renin release from 555_+85 to 1820+--220 U/mln (p~0.00l). This was in part due to an increase in flow, but also to a rise in the ven~ arterial concentration gradient for renin. Even when flow did net change, renin secretion rose. In the doxazosine group only minor changes in flow occurred. In none of the experiments did blood pressure change. In six patients the concurrent infusion of the alpha-2 agonist B-HT 933 blunted the rise in secretion evoked by yohimbine alone. It is concluded that alpha-2 adrenoceptors in the kidney play an important role In the regulation of renin release (end also in the regulation of renal flow). Alpha-I adrenoceptors seem to be less significant. HIGH DOSE…
Chapter 27 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 27 in:
Toxicology of Metals
Eds L W Chang, L Magos, T Suzuki
CRC Lewis Publishers 1996
pp. 439-454
Chapter 28 in: Toxicology of Metals Eds L W Chang, L Magos, T Suzuki CRC Lewis Publishers 1996 pp... more Chapter 28 in:
Toxicology of Metals
Eds L W Chang, L Magos, T Suzuki
CRC Lewis Publishers 1996
pp. 455-460
