[Show abstract][Hide abstract] ABSTRACT: In 1987, a cohort study was initiated in the Amsterdam/Zaandam region of The Netherlands to study possible effects of dioxins on development and growth in a population of breastfed children selected after an optimal pregnancy and delivery and birth weight above 2500 grams. Effects on thyroid hormone metabolism, liver, haematology and immunology, and retinol binding protein were found in neonates. Follow-up was performed at the age of 2½ years, 8–12 years and 13–18 years. Neonatally an increase in free thyroxine and thyroid stimulating hormone was found, indicating a change in set point. An enhanced psychomotor maturation was seen at the age of 2½ years. Negative effects on lung function and on brain development (studied with neurophysiological tests of visuo-motoric and cognitive performance) were demonstrated in the age of 8–12 years. In adolescence preliminary results show a delay of almost 1 year in breast development in girls in association with higher (above 40 ng International Toxic Equivalents dioxin) prenatal dioxin exposure and again a negative effect on innate immunity. The abnormalities found indicate an increased vulnerability for more stressful circumstances. New chemicals comparable to dioxins or contaminated with dioxins should not be allowed on the market, or if already there, must be banned.
International Journal of Environment and Health 01/2008; 2(3):429-438. DOI:10.1504/IJENVH.2008.020934
[Show abstract][Hide abstract] ABSTRACT: Increased central opioidergic neurotransmission, mediated by endogenous opioid peptide agonists, contributes to the pruritus of cholestasis. There are interrelationships between the opioid and serotonin neurotransmitter systems. The serotonin 5-HT3 receptor subtype antagonist, ondansetron, has been reported to ameliorate centrally-mediated pruritus induced by exogenously administered opiates. This study was designed to determine whether long-term oral administration of ondansetron is efficacious in ameliorating pruritus complicating chronic liver disease.
Seventeen patients with severe pruritus complicating established chronic liver disease were randomized to receive, double-blind, ondansetron (8 mg) or a placebo orally; each was administered thrice daily for a 4-week period. Endpoints were subjective scores of pruritus and objective 24-hour measurements of scratching activity. Analysable data were generated in 13 of the patients.
Ondansetron therapy was associated with ameliorations of pruritus that appeared to be clinically significant in 5 patients (38%); in these 5 patients the mean decrease in a subjective score of pruritus was 27% of the scale of the score. However, these apparent ameliorations were not associated with robust decreases in scratching activity. For the whole group of 13 patients mean scratching activity during ondansetron therapy was not significantly less than that during treatment with placebo (p = 0.19). The total time that patients were not scratching was similar during treatment with ondansetron and placebo (p = 0.57).
The findings suggest that serotoninergic neurotransmission, in neurons bearing receptors of the 5-HT3 subtype, plays no more than a minor role in the mediation of pruritus complicating chronic liver disease. The lack of an association between the results of applying subjective scores of pruritus and scratching activity emphasizes the need to include an objective quantitative efficacy endpoint in the design of trials of new therapies for pruritus.
[Show abstract][Hide abstract] ABSTRACT: Despite severe abnormalities of the corneal endothelium in the iridocorneal endothelial (ICE) syndrome, the cornea can remain clear and maintain its normal thickness for years before corneal decompensation occurs. The aim of this study is to analyze this discrepancy by studying corneal hydration control in the ICE syndrome.
In four subjects with unilateral ICE syndrome, without signs of corneal decompensation, a "corneal stress test" was performed in both the affected and the unaffected eye. The stress test measures the recovery of corneal thickness after swelling induced by wearing a soft contact lens with the eyes closed. Corneal thickness was measured by noncontact pachymetry.
Mean baseline corneal thickness of affected eyes (535+/-56 microm) was not different from unaffected eyes (526+/-39 microm). On the other hand, the corneal stress test showed a smaller induced swelling in affected eyes (33+/-15 microm) compared with unaffected eyes (67+/-11 microm) and a slower recovery of corneal thickness in affected eyes. In one of four subjects, the cornea of the affected eye was calculated not yet to have recovered its original thickness before midnight. After this finding, although the cornea of this subject did not show any signs of clinical decompensation, the study was discontinued.
Corneal hydration control is altered in the ICE syndrome. The ICE cornea can maintain its normal thickness despite severe morphologic abnormalities of the endothelium. Because we found that recovery of corneal thickness can be extremely slow, it cannot be guaranteed that such corneal "stress tests" are completely safe for subjects with the ICE syndrome, and we therefore feel that they should no longer be performed in these subjects.
[Show abstract][Hide abstract] ABSTRACT: Low gas-permeable contact lens wear of polymethyl methacrylate or hydroxyethyl methacrylate material is known to cause morphologic abnormalities in the corneal endothelial cell layer. These lenses were widely prescribed and successfully worn until their use was actively discouraged in the late 1980s and early 1990s. This study was designed to investigate whether discontinuation of low gas-permeable contact lens wear leads to an improvement of corneal endothelial cell morphology.
At the time of discontinuation and at least 5 years after discontinuation of low gas-permeable contact lens wear, noncontact specular photographs of the central corneal endothelium were made in 66 patients (14 male and 52 female, mean age 37.7 +/- 8.4, range 24.6-69.0). By computer analysis of endothelial photographs, parameters for polymegethism and pleomorphism were calculated, as well as cell density.
Mean follow-up time between photographs was 6.8 years (SD 1.1). Sixty-one patients were refitted with rigid high gas-permeable contact lenses or high-water-content soft lenses, and 5 patients switched to spectacle wear. A small but significant recovery of the corneal endothelial cell morphology was found for the mean coefficient of variation of cell area, from 37.5 to 35.7 (P = 0.022), and for the coefficient of variation of the number of sides, from 13.1 to 12.4 (P = 0.004). The mean percentage of hexagonal cells increased from 54.2 to 56.2 (P = 0.013). Although the corneal endothelial cell morphology improved significantly on cessation of LGP contact lens wear, the values did not return to levels observed in normal, non-contact lens wearing individuals. During follow-up, the mean endothelial cell density decreased significantly (P = 0.001) from 2994 to 2890 (a 3.5% cell loss in 6.8 years), which is similar to the known normal age-related cell loss of 0.6% per year in non-contact lens wearing healthy individuals.
Endothelial polymegethism and pleomorphism caused by PMMA or HEMA contact lens wear is partly reversible.
[Show abstract][Hide abstract] ABSTRACT: Video game seizures have been reported in photosensitive and non-photosensitive patients with epilepsy. The game Super Mario World, has led to many cases of first seizures. We examined whether this game was indeed more provocative than other programs and whether playing the game added to this effect.
We prospectively investigated 352 patients in four European cities, using a standard protocol including testing of a variety of visual stimuli. We correlated historical data on provocative factors in daily life with electroencephalographic laboratory findings.
The video game, Super Mario World proved more epileptogenic than standard TV programs and as provocative as programs with flashing lights and patterns. Most striking was the fact that video game-viewing and-playing on the 50 and 100 Hz TV was significantly more provocative than viewing the standard program (P < 0.001, P < 0.05 respectively). Playing the video game Mario World on a 50 Hz TV, appeared to be significantly more provocative than playing this game on the 100 Hz TV (P < 0.001). Of 163 patients with a history of TV-, VG- or CG-seizures, 85% of them showed epileptiform discharges in response to photic stimulation, 44% to patterns, 59% to 50 Hz TV and 29% to 100 Hz TV.
Children and adolescents with a history of video game seizures are, in the vast majority, photosensitive and should be investigated with standardised photic stimulation. Games and programs with bright background or flashing images are specifically provocative. Playing a video game on a 100 Hz TV is less provocative [published with videosequences].
Epileptic disorders: international epilepsy journal with videotape 06/2002; 4(2):121-8. · 0.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Perinatal exposure to Dutch background dioxin levels is rather high. Studies of calamities have shown that dioxins negatively influence the respiratory system. It was hypothesized that perinatal exposure to background dioxin levels leads to lung suboptimality, probably through developmental interference. This study aimed to assess lung function in relation to perinatal dioxin exposure. Spirometry was performed in 41 healthy children (aged 7-12 y, mean 8.2 y) with known perinatal dioxin exposure. The ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC ratio) was determined. A complete medical history was taken. The prenatal exposure ranged from 8.74 to 88.8 (mean 34.6) ng TEQ dioxin kg fat−1, measured in breast milk. The postnatal exposure ranged from 4.34 to 384.51 (mean 75.4) ng TEQ dioxin. Twelve children had to be excluded. A significant decrease in lung function in relation to both prenatal (p= 0.045) and postnatal (p= 0.0002) dioxin exposure was seen in the 29 non-excluded children. A clinical association between chest congestion and perinatal dioxin exposure was seen.
Conclusion: Perinatal background dioxin exposure may be inversely associated with the FEV1/FVC ratio.
[Show abstract][Hide abstract] ABSTRACT: To investigate the healing of intra-abdominal and extra-abdominal jejunal anastomoses that were surrounded by a hyaluronic acid/carboxymethylcellulose membrane (Seprafilm) in rats.
University hospital, The Netherlands.
56 male Wistar rats.
28 rats had jejunojejunostomies placed subcutaneously and 28 had them placed intra-abdominally. Half of each group of anastomoses were surrounded by Seprafilm.
After 3 or 7 days, the anastomoses were tested for bursting pressure, tensile strength, and hydroxyproline concentrations.
There were numerous strong adhesions around the anastomoses in the subcutaneous position and Seprafilm had no influence on their extent. Bursting pressure and hydroxyproline concentrations were not affected by position or Seprafilm treatment. Tensile strength was significantly higher in the subcutaneous position (p < 0.01), but was unaffected by Seprafilm.
Anastomotic healing was not impaired in the subcutaneous or intraperitoneal position in this model. Seprafilm had no effect on the anastomosis.
The European Journal of Surgery 09/2000; 166(8):654-8. DOI:10.1080/110241500750008349
[Show abstract][Hide abstract] ABSTRACT: To use laboratory data and liver biopsies, prospectively obtained from hepatitis B surface antigen (HBsAg) and anti hepatitis B e antigen (anti-HBe) positive patients, for the assessment of: (1) the relation between biopsy length/number of portal tracts and sampling error; (2) the relation between the severity of piecemeal necrosis and the new grading terminology (minimal, mild, moderate, and severe chronic hepatitis); and (3) liver pathology, which has not been studied in patients with this specific serological profile.
The study group (n = 174) included 104 patients with normal aminotransferase concentrations and no cases with clinically apparent cirrhosis. The specimen length and number of portal tracts were measured at light microscopy examination. Sampling error analysis was related to the discrepancies between aminotransferase concentrations versus histological grade. Detailed histological scorings were undertaken by the reference pathologist and compared with laboratory and hepatitis B virus (HBV) DNA precore sequence data.
Sampling error seemed to be a constant feature, even for biopsies > or = 20 mm, but increased dramatically in biopsies < 5 mm long and/or containing less than four portal tracts. Between 25% and 30% of biopsies, graded as "mild" or "moderate" activity showed features of moderate and severe piecemeal necrosis, respectively. Ten per cent of the patients with normal aminotransferase values had stage III-IV hepatic fibrosis, and 20% had piecemeal necrosis. Only cytoplasmic, not nuclear, core antigen expression was a strong predictor of high hepatitis B viraemia. There was no association between precore stop codon mutations, grade/stage of liver disease, and hepatitis B core antigen (HBcAg) expression.
The specimen available for light microscopical examination should be > 5 mm long and should contain more than four portal tracts. In addition, the new grading terminology might give the clinician an inappropriately mild impression of the severity of piecemeal necrosis. Furthermore, even in the presence of normal aminotransferase concentrations, considerable liver pathology can be found in 10-20% of HBsAg and anti-HBe positive individuals; such pathology is not associated with the occurrence of precore stop codon mutations.
Journal of Clinical Pathology 08/2000; 53(7):541-8. · 2.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The relationship between MR patterns of brain damage and type or timing of perinatal hypoxia-ischemia was studied. MR images of 104 children with evidence of bilateral posthypoxic-ischemic brain damage and neonatal records were reviewed. Three different MR patterns were found. Periventricular leukomalacia occurred in 73 children, in 82% after a history of subacute or chronic hypoxia-ischemia, in 71% after preterm birth. Predominant lesions of basal ganglia and thalamus occurred in 21 children, in 95% preceded by acute profound asphyxia, in 85% after term birth. Multicystic encephalopathy occurred in 10 infants, in 70% preceded by mild signs of hypoxia-ischemia, followed by an unexpectedly severe encephalopathy, in 60% after term birth. Statistical analysis showed that the patterns of injury were primarily related to the type of hypoxia-ischemia. We conclude that the type of hypoxia-ischemia, rather than the postconceptional age at occurrence determines the pattern of brain injury.
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to assess incidence, risk factors, clinical symptomatology and short-term outcome of unilateral thalamic lesions in preterm infants, as detected by ultrasound. Sixteen preterm infants, born after a gestational age of less than 35 weeks, with a unilateral thalamic lesion, but without additional significant cerebral lesions, were included. Their follow-up data were compared to those of a selected control group consisting of healthy premature infants. In addition, the neonatal clinical data of the patients with a thalamic lesion were compared to data of the healthy control group and of a general control group, consisting of a non-selected year-cohort of preterm infants. During the study period, the incidence of unilateral thalamic lesions was 5.3% among preterm infants. Ultrasound was not able to distinguish between hemorrhagic and ischemic lesions. The infants with a unilateral thalamic lesion had a more complicated respiratory course and were ventilated significantly longer than infants without such a lesion. The infants with a thalamic lesion had disturbances in tone, persisting throughout infancy, while the healthy control group showed only transient disturbances in tone.
[Show abstract][Hide abstract] ABSTRACT: A follow-up study was performed in 42 premature infants in whom serial neonatal ultrasound and a single neonatal MRI of the brain was normal, or showed mild periventricular white matter changes. The aim of the study was to evaluate the clinical significance of periventricular signal intensity changes on MRI and to compare the predictive value of neonatal MRI with that of ultrasound. The infants underwent repeated standardised motor assessments and developmental tests. MRI was repeated at the corrected age of 12 months. Pronounced periventricular signal intensity changes on neonatal MRI and periventricular echodensities (flaring) on ultrasound were associated with a high incidence of transient motor problems during infancy. The degree of echogenicity carried the highest predictive value, as compared to duration of flaring on ultrasound and degree of periventricular signal intensity change on MRI. It is concluded that signal intensity changes on neonatal MRI represent the same ischaemic change of the periventricular white matter as flaring on ultrasound and that routine neonatal MRI screening is not warranted in premature infants without clinical evidence of neurological problems and with normal or mildly abnormal ultrasound scans. Recording of the degree of echogenicity should become a routine procedure in neonatal cerebral ultrasonography.
[Show abstract][Hide abstract] ABSTRACT: Due to the aging of the population on one hand and both medical and dental innovations on the other, the number of medical complications which occur during dental treatment is expected to rise. In order to prevent such complications, dental practitioners have used a medical risk-related history which includes risk determination and preventive measures (together the MRRH system). In this study, the medical complications which occurred in their practice have been compared with those recorded by a control group.
First, a tested registration form was used. In addition, the group using the MRRH system had previously attended a 1-day introductory course de voted to the MRRH system. Furthermore, a power analysis was used to determine the group sizes. The registration period was set at 1 year, during which the dentists sent in monthly reports. Only patients over the age of 18 were included, after having given their oral consent. An independent diagnosis was given of all registered medical complications by two different internists.
A total of 208 medical complications were reported: 45 complications were reported by the 62 dentists who used the MRRH system (reference group) and 163 by the 215 dentists of the control group. First, it should be noted that some reports did not register vital signs; this is reflected in categories such as "no diagnosis," "collapse eci," and "others." Second, the study has revealed that the reference group has registered the heart rate and the frequency of breathing of patients more frequently than the control group. Also, a relatively lower percentage of complications was recorded within the reference group due to the intravenous injection of local anesthetics.
The number of medical complications recorded in the two groups shows little variation. There is a considerable difference, however, in the nature of these complications.
Preventive Medicine 06/1999; 28(5):481-7. DOI:10.1006/pmed.1998.0448 · 3.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To introduce a new model describing human in vivo corneal deswelling after hypoxic contact lens wear, based on a damped harmonic oscillator, which can describe an overshoot in corneal deswelling, to compare this new model with the currently used exponential model, and also to test whether a diurnal variation in baseline corneal thickness exists that would have to be taken into consideration when calculating corneal deswelling curves.
In nine healthy young adults, corneal thickness was measured every 30 minutes for 11.5 hours on average using modified optical pachometry (natural test). On another day, corneal deswelling was monitored for 11.1 hours on average after 2 hours of hypoxic contact lens wear (stress test). The damped harmonic oscillator model and the exponential model were used to calculate best-fitting deswelling curves. Natural test data were analyzed for the presence of a trend. Goodness of fit of the curves to the experimental data was analyzed using the F test.
In 82% of the deswelling curves the new damped harmonic oscillator model provided a better fit to the data than the exponential model (P < 0.05). An average overshoot in corneal thickness recovery of 5 microm (range, 0-11 microm) was found. In 50% of the natural tests significant trends were found, without any consistent similarities. The overshoot could not be explained by these trends.
The new damped harmonic oscillator model describes corneal deswelling after hypoxic contact lens wear more accurately than the exponential model. No consistent diurnal variation could be demonstrated.
[Show abstract][Hide abstract] ABSTRACT: Healing of a cervical esophagogastrostomy is frequently impaired, resulting in a higher incidence of leakage and stricture formation, as compared to an intrathoracic anastomosis. Lack of mesothelial factors is hypothesized to contribute to this impaired anastomotic healing. The aim of this prospective study was to determine whether a free peritoneal patch around a cervical esophagogastrostomy can improve anastomotic healing.
In 23 consecutive patients a free peritoneal patch was fixed around a cervical esophagogastrostomy. Results were compared to those of a historical control group of 41 patients. Clinical and/or radiographic leakage and stenosis requiring endoscopic dilatation were used as endpoints.
Three patients died in the early postoperative period (in-hospital mortality 3/64 = 5%). Leakage rate was 13% (3/23) in the group with a patch and 15% (6/41) in the control group (p = 0.90). At 6-month follow-up, the incidence of stenosis was significantly higher (65%) in the group with a patch, compared to 31% in the control group (p = 0.02).
A peritoneal patch does not affect the leakage rate but increases the incidence of postoperative stenosis of a cervical esophagogastrostomy. Therefore, its clinical application is contraindicated.
Digestive Surgery 02/1999; 16(5):379-84. DOI:10.1159/000018751 · 2.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE. TO introduce a new model describing human in vivo corneal deswelling after hypoxic contact lens wear, based on a damped harmonic oscillator, which can describe an overshoot in corneal deswelling, to compare this new model with the currently used exponential model, and also to test whether a diurnal variation in baseline corneal thickness exists that would have to be taken into consideration when calculating corneal deswelling curves. METHODS. In nine healthy young adults, corneal thickness was measured ever)' 30 minutes for 11.5 hours on average using modified optical pachometry (natural test). On another day, corneal deswelling was monitored for 11.1 hours on average after 2 hours of hypoxic contact lens wear (stress test). The damped harmonic oscillator model and the exponential model were used to calculate best-fitting deswelling curves. Natural test data were analyzed for the presence of a trend. Goodness of fit of the curves to the experimental data was analyzed using the F test. RESULTS. In 82% of the deswelling curves the new damped harmonic oscillator model provided a better fit to the data than the exponential model (P < 0.05). An average overshoot in corneal thickness recovery of 5 /xm (range, 0-11 /nm) was found. In 50% of the natural tests significant trends were found, without any consistent similarities. The overshoot could not be explained by these trends. CONCLUSIONS. The new damped harmonic oscillator model describes corneal deswelling after hypoxic contact lens wear more accurately than the exponential model. No consistent diurnal variation could be demonstrated. (Invest Ophthalmol Vis Sci. 1999;40:312-319)
[Show abstract][Hide abstract] ABSTRACT: Stress is often noted by patients to be a precipitating factor in causing seizures. No precise data are, however, available. In 1995 for 250,000 inhabitants in The Netherlands, a serious life event occurred within a period of seven days. An extreme high water level in the province of Gelderland, with the possibility of a flood, made the government decide to evacuate people and their livestock. This retrospective study investigated the influence of this forced evacuation on the seizure frequency of patients with epilepsy, compared with patients of the same age and type of epilepsy living outside the evacuation area at the time of the threatening flood.
Information regarding epilepsy syndrome, seizure type, and frequency was derived from seizure diaries and medical histories of 30 evacuated patients and 30 matched control patients.
Of the 30 evacuees, eight showed an increase and one a decrease in seizure frequency during or shortly after the evacuation period, compared with one and zero control patients, respectively. These results proved to be statistically significant (p < 0.05).
Our data support the hypothesis that there is a relation, albeit small, between a stressful life event and seizure frequency.
[Show abstract][Hide abstract] ABSTRACT: To determine the effect of brief early exposure to cows' milk on atopy in the first 2 years of life.
Double blind, placebo controlled, randomised feeding intervention trial (Bokaal study).
Dutch midwifery practices.
1533 breast fed neonates.
Exposure to cows' milk protein (n = 758) or a protein free placebo (n = 775) during the first 3 days of life.
Clinical atopic disease and any positive radioallergosorbent (RAST) tests at 1 year of age.
Atopic disease in the first year was found in 10.0% (cows' milk) v 9.3% (placebo) of the children, with a relative risk of 1.07; in the second year, atopic disease was found in 9.6% v 10.2%, respectively, with a relative risk of 0.94. Per protocol analysis showed similar results. Any RAST positive test was found in 9.4% (cows' milk) v 7.9% (placebo) of children, with a relative risk of 1.19. Stratified analysis for high family risk of allergy showed a doubled incidence of atopic disease but no effect from the intervention.
Early and brief exposure to cows' milk in breast fed children does not increase the risk of atopic disease in the first 2 years.
Archives of Disease in Childhood 09/1998; 79(2):126-30. DOI:10.1136/adc.79.2.126 · 2.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: To investigate and compare the incidence and type of complications related to central venous catheters in AIDS patients and in two control groups of non-AIDS patients.Methods: Three groups of patients requiring permanent venous access were investigated retrospectively between January 1988 and January 1994. The indication for Port-A-Cath system implantation in AIDS patients was administration of virustatics and/or total parenteral nutrition (TPN) (group A, n=71), in non-AIDS immunocompromised patients it was chemotherapy (group B, n=65) and in immunocompetent patients it was home TPN (group C, n=14). Complications were categorized into infectious complications and non-infectious complications, and related to patient characteristics, degree of immunosuppression, type of therapeutic medium, insertion technique and catheter survival time.Results: Type of complications could not be related to type of insertion procedure or length of operation. Catheter-related mortality was low in all groups (0–1%). Type of complications could be related to catheter survival time in all groups. Infectious complications could not be related to degree of immunosuppression (CD4+ lymphocyte counts or white blood cell count). Unexpectedly, the incidence of both infectious and non-infectious complications was significantly higher for group C than for groups A and B, probably because of type of medium and/or differences in handling of the catheter.Conclusion: In this retrospective study, central venous catheters appear to be safe and are well tolerated by AIDS patients, as compared to non-AIDS immunocompromised patients receiving chemotherapy and immunocompetent home-TPN patients.