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D Pretorius

Publications and source records attributed to D Pretorius.

7 recordsLinked to original sources
PubMed1991

Morbidity associated with prenatal disruption of the dividing membrane in twin gestations.

We report eight cases of intrauterine rupture of the dividing membranes in diamniotic twin gestations and the resulting perinatal morbidity and mortality. The poor outcomes associated with these intrauterine amniotic ruptures included fetal and neonatal death secondary to cord entanglement, preterm rupture of the membranes, preterm labor and delivery, and amniotic band syndrome. The overall perinatal mortality rate was 44% (seven of 16), and the mean gestational age at delivery was 29 weeks (range 22-34). Possible etiologies for this intrauterine diamniotic rupture include fetal trauma to the dividing membranes, amniocentesis, infection, and developmental disturbances. A new theory is examined to explain the surviving twin's morbidity associated with intrauterine death of the co-twin. This study suggests that intrauterine rupture of diamniotic twin membranes carries a perinatal mortality consistent with that of true monoamniotic gestations and that, in fact, this entity may be more common than previously thought. Finally, a suspected monoamniotic gestation cannot be ruled out by the historic presence of a dividing membrane on previous ultrasound examination.

Adolescent↗
PubMed1989

Gallbladder function is altered in sickle hemoglobinopathy.

Despite comparable rates of hemolysis, only 50% of patients with sickle hemoglobinopathy (SH) develop pigment gallstones by age 20 yr. Thus, pathogenetic factors, other than hemolysis, may contribute to gallstone formation. In the present study we determined whether gallbladder function, measured by real-time ultrasonography or bile acid metabolism, determined by isotope dilution-mass spectrometry, were altered in adolescents and young adults with SH. Compared with healthy controls, SH subjects had larger fasting (27 +/- 16 vs. 15 +/- 5 ml, p less than 0.02), and residual (8 +/- 6 vs. 4 +/- 2 ml, p less than 0.03) volumes of the gallbladder, but similar rates of emptying (0.029 +/- 0.016 vs. 0.034 +/- 0.029 min-1) and percentage of fasting volume emptied (71% +/- 13% vs. 72% +/- 14%). In SH subjects, the volume and emptying of the gallbladder were similar between those with and without gallstones. Some SH subjects had stasis of bile within the gallbladder, as demonstrated by isotopic disequilibrium between the circulating bile acid pool and bile stored in the gallbladder. Subjects with SH with gallstones tended to have smaller bile acid pools than SH subjects without gallstones (81 +/- 11 vs 163 +/- 91 mumol/kg, p = 0.051). We conclude that adolescents and young adults with SH have enlarged gallbladders that retain an increased postprandial volume of bile. Bile retention within the gallbladder may lead to stasis and contribute to the pathogenesis of pigment gallstones.

Adolescent↗
PubMedDate not supplied

The role of nuclear scanning in head and neck surgery.

A number of procedures in nuclear medicine are available to assist the surgeon in evaluating pathologic conditions of the head and neck. Gallium-67 citrate scanning is occasionally useful in determining the extent of head and neck tumors but rarely can it detect an occult tumor and it cannot distinguish between an infection and a tumor. Technetium-99m pertechnetate can be used to evaluate diseases of the salivary glands including 123 and technetium-99m pertechnetate are commonly used to obtain images of the thyroid, but some malignant thyroid nodules will accumulate technetium-99m pertechnetate and the suspicious character of the nodule may be only appreciated by iodine scanning. The use of iodine 131 is generally limited to the detection of a substernal thyroid, therapeutic thyroid ablation, and the treatment of hyperthyroidism and thyroid cancer. Bone scanning has been used experimentally to evaluate the healing of mandibular bone grafts and to detect local extension of primary head and neck tumors to skull and facial bones.

Abscess↗