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B van der Wildt

Publications and source records attributed to B van der Wildt.

7 recordsLinked to original sources
PubMed1999

Glutathione S-transferase Alpha 1-1 and aminotransferases in umbilical cord blood.

Recent data suggest that levels of glutathione S-transferase Alpha 1-1 in umbilical cord plasma may be a good indicator of neonatal hepatocellular integrity. In order to fully understand the significance of this new marker we compared the values of glutathione S-transferase Alpha 1-1 (GSTA1-1) with that of the well known liver function markers alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in arterial and corresponding venous umbilical cord blood of 93 patients. In addition, in 49 of these patients maternal venous blood was also studied. Both arterial and venous umbilical cord GSTA1-1 and AST levels were significantly higher than corresponding maternal venous levels, whereas ALT levels were not. Arterial umbilical cord GSTA1-1 correlated significantly with the corresponding AST and ALT levels (R = 0.46, P < 0.0001 and R = 0.41, P < 0.0001, respectively). Arterial umbilical cord AST correlated significantly with corresponding ALT levels (R = 0.58, P < 0.0001). Arterial umbilical cord plasma GSTA1-1 levels were significantly lower in the cesarean delivery group as compared to the vaginal birth group, whereas no difference was noted for AST or ALT. Arterial umbilical cord AST and GSTA1-1 levels correlated significantly with base deficit (R = 0.29, P = 0.005; R = 0.29, P = 0.005, respectively), whereas ALT did not (R = 0.06, P = 0.54). Arterial umbilical cord AST, ALT, and GSTA1-1 levels correlated significantly with birthweight. In conclusion, GSTA1-1 levels as assessed in neonatal umbilical cord blood, being unrelated to maternal levels, seem to be a more sensitive marker for early neonatal hepatocellular integrity as compared to ALT or AST and even might detect impaired hepatocellular integrity due to the vaginal birth process. Umbilical cord GSTA1-1 may provide a valuable indicator of neonatal condition immediately after birth, the clinical relevance of which needs to be further established.

Adult↗
PubMed1999

Feasibility of minimally invasive intrauterine fetal access in a monkey model.

PURPOSE: We evaluated new intervention techniques and surgical instruments in a fetal monkey model to determine improvements that would be useful for early intrauterine intervention. Our findings may be helpful in the future for treating select cases of severe prenatal obstructive uropathology. MATERIALS AND METHODS: In a series of experiments on 18 pregnant rhesus monkeys (Macaca mulatta) at mid trimester we assessed various endoscopic intra-amniotic access techniques as well as morbidity, mortality and possibilities for fetoscopy. RESULTS: In all 18 fetuses adequate fetoscopy was possible with no maternal mortality. Of the 18 pregnancies 14 went to term with no early or late postoperative complications. Technical improvements changed the intrauterine access technique from open placement of trocars to the use of the Seldinger technique, gun introduction of needles with small caliber sheets and small caliber introduction trocars, resulting in minimal amniotic membrane separation. Various rigid and flexible endoscopes were evaluated for fetoscopy and up to 3 cannulas were placed. No change in the fetal growth pattern was observed on postoperative ultrasound. Subsequent pregnancies occurred during this study period, and there were no acceptance problems of the newborns by the mothers. CONCLUSIONS: New techniques have led to improved intrauterine fetal access. Morbidity mainly depends on the disruption of amniotic membranes, which has an important preterm role. Adapted endoscopes and other instruments offer new possibilities for fetal diagnosis and therapy in the future. Our primate model seems to be suitable for evaluating these new techniques before they are used in a clinical setting.

Animals↗
PubMed1997

Access techniques in endoscopic fetal surgery.

Endoscopic surgery may in the future become an attractive alternative to open fetal surgery. Herein, we present our evolving experience with minimal access techniques in sheep and nonhuman primate models. Fifty-two pregnant sheep (term = 145 d) were used. All underwent laparotomy. Cannulas were 5 mm diameter with balloon fixation device. In group I (95-105 d, n = 22, and 70-74 d, n = 19), a total of 119 cannulas were placed by open hysterotomy and pursestring suture through myometrium and membranes. In group II (n = 11), access was obtained by Seldinger guidewire technique. Eight cannulas were introduced over a dilator and 7 were radially expanding endoscopic cannulas. Fifteen cannulas were also placed in 5 pregnant Rhesus monkeys using Seldinger and radially expanding techniques. Cannula removal was followed by insertion of a collagen sponge plug and oversewing of the myometrium. Mini-hysterotomies with purse-stringing provided excellent access to the amniotic cavity, without dissection of the membranes. Classic Seldinger technique with forward dilatation was equally effective, but caused stretching of membranes. In sheep and in primates, Seldinger technique with radial dilatation allowed safe access without membrane separation. Leak-proof removal of the cannulas was achieved in all primates. Open hysterotomy with purse-string and balloon-tipped cannula provides efficient and safe access to the gravid sheep uterus. Seldinger technique allows equally secure access, and alleviates the need for hysterotomies. Radial dilatation of the porthole eliminates forward dissection of the membranes, both in sheep and primate models. This method, and collagen plug insertion upon completion of the endoscopic procedure, may provide a truly minimally invasive approach to in-utero surgery.

Animals↗
PubMed1980

Diabetes insipidus in pregnancy as a first sign of a craniopharyngioma.

A patient is described who developed diabetes insipidus during pregnancy. During a revised Carter test performed at 36 wk gestation using DDAVP (1-desamino-8-D-arginine-vasopressin), uterine activity was recorded with a maximum activity of 120 Montevideo Units. The induction of uterine activity by DDAVP in our patient might be related to the high endogenous oxytocin levels or to the far advanced state of amenorrhea. Post partum, the patient reported decreased vision, and the visual fields were found to be abnormal. A neurosurgical procedure followed, and the diagnosis of craniopharyngioma was made.

Adult↗
PubMed1979

Mechanisms of late decelerations in the fetal heart rate. A study with autonomic blocking agents in fetal lambs.

Fetal heart rate decelerations resembling the late deceleration FHR pattern were produced in fetal sheep by periodic occlusion of the maternal common hypogastric artery for 30-60 sec. Transient fetal hypertension also occurred during the occlusions. Alpha-adrenergic blockade with phentolamine eliminated or markedly reduced the hypertensive response. FHR decelerations still occurred intermittently with some occlusions; however, their character was greatly altered. After parasympathetic blockade with atropine, the decelerations were replaced by periodic FHR accelerations during the occlusions. These accelerations were, in turn, eliminated by the beta-adrenergic blocking agent, propranolol. In the presence of combined parasympathetic, alpha- and beta-adrenergic blockade, the FHR remained essentially constant during the hypogastric artery occlusions in non-acidemic fetuses. FHR decelerations persisted after parasympathetic or total autonomic blockade when the fetuses were significantly hypoxic, as judged by depressed arterial blood pH and base excess values. Beat-to-beat variability of the baseline FHR persisted in the face of severe hypoxia and acidosis. These observations demonstrate that reflex mechanisms are involved importantly in the genesis of late deceleration FHR patterns in the acutely hypoxemic fetus, but that direct depression of myocardial rhythmicity becomes a factor as hypoxic acidosis develops.

Acetylcholine↗