The in vitro fertilisation programme at Tygerberg Hospital and the University of Stellenbosch. Five years' experience, April 1983-January 1988

The results of the in vitro fertilisation programme at Tygerberg Hospital for the period April 1983 to January 1988 are presented. Of the 1117 laparoscopies performed, 825 patients reached the transfer stage. A live-birth rate of 9.3% was achieved. The pregnancy rate after transfer of 4 embryos was 25.9% compared with 15.4% after 2 embryos and 10.8% after 3 embryos (P = less than 0.0001). The multiple pregnancy rate was 2.8% in the group receiving 2 embryos and 11.7% and 10.4% in those receiving 3 and 4 embryos, respectively. Of the 77 successful pregnancies (90 babies), 1 baby died at 34 weeks' gestation as the result of abruptio placentae due to preeclampsia and 1 cot death occurred. The only congenital abnormality encountered was a cleft palate.     

Whole body MR imaging in ankylosing spondylitis: a descriptive pilot study in patients with suspected early and active confirmed ankylosing spondylitis

Background  

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis.     

The effect of prostaglandin E1 on acute pulmonary artery hypertension during oleic acid-induced respiratory dysfunction

This study examined the general effect of intravenous PGE1 on RV Ees and effective PA elastance (EA) during acute pulmonary hypertension associated with oleic acid infusion. In eight pigs, RV end-systolic elastance was quantified with the Ees and Ea was defined with reference to the Windkessel model. Oleic acid infusion increased mean PAP and Ea. Prostaglandin E1 reduced PAP and decreased Ea. Ees did not change throughout the study. Mean arterial pressure was reduced and the pulmonary shunt was increased after PGE1 infusion. The PaO2 was reduced. Data from this study suggest that although PGE1 is effective in reducing PAP, it is not as effective in reducing RV afterload. Furthermore, PGE1 does have significant side effects such as reduction of systemic arterial pressure and an increase in pulmonary shunt.     

The effect of inhibition of mitochondrial energy metabolism on the transient inward current of isolated guinea-pig ventricular myocytes

Delayed afterdepolarizations (DADs) might underlie ischemic or reperfusion arrhythmias (Ferrier et al., 1985; Coetzee and Opie, 1987). These DADs are the result of a transient inward current iti, which is caused by instability of the intracellular level of free Ca2+ (Cai) due to an oscillatory release of Ca from the sarcoplasmic reticulum (Kass et al., 1978). DADs are known to be abolished by hypoxia and by metabolic inhibition (Di Gennaro et al., 1987; Coetzee and Opie, 1987), which could be caused by a number of different mechanisms: (1) The large increase of potassium conductance associated with metabolic inhibition (Vleugels et al., 1980; Isenberg et al., 1983) could prevent iti from causing a marked depolarization, and would thus "mask" the DADS. (2) Although metabolic inhibition will eventually result in an increase of Cai, a temporary decrease could initially take place, thereby minimizing the Ca instability. Two mechanisms are known which might produce such an effect: Firstly, the shortening of the action potential which occurs during metabolic inhibition will markedly reduce the time during which Ca channels remain open, thereby causing a diminished total Ca influx during the action potential (Isenberg et al., 1983; Noma and Shibasaki, 1985; Kakei et al., 1985). Secondly, a direct reduction of iCa by a decrease in ATP concentration, described by Irisawa and Kokubun (1983), could also contribute to a decreased Ca load. (3) Metabolic inhibitors could possibly interfere with the cycling of Ca between different compartments within the cell, thereby altering the temporal variation in Cai, and thus influencing iti.(ABSTRACT TRUNCATED AT 250 WORDS)