Levels of specificity of Xylaria species associated with fungus-growing termites: a phylogenetic approach.

Fungus-growing termites live in obligate mutualistic symbiosis with species of the basidiomycete genus Termitomyces, which are cultivated on a substrate of dead plant material. When the termite colony dies, or when nest material is incubated without termites in the laboratory, fruiting bodies of the ascomycete genus Xylaria appear and rapidly cover the fungus garden. This raises the question whether certain Xylaria species are specialised in occupying termite nests or whether they are just occasional visitors. We tested Xylaria specificity at four levels: (1) fungus-growing termites, (2) termite genera, (3) termite species, and (4) colonies. In South Africa, 108 colonies of eight termite species from three termite genera were sampled for Xylaria. Xylaria was isolated from 69% of the sampled nests and from 57% of the incubated fungus comb samples, confirming high prevalence. Phylogenetic analysis of the ITS region revealed 16 operational taxonomic units of Xylaria, indicating high levels of Xylaria species richness. Not much of this variation was explained by termite genus, species, or colony; thus, at level 2-4 the specificity is low. Analysis of the large subunit rDNA region, showed that all termite-associated Xylaria belong to a single clade, together with only three of the 26 non-termite-associated strains. Termite-associated Xylaria thus show specificity for fungus-growing termites (level 1). We did not find evidence for geographic or temporal structuring in these Xylaria phylogenies. Based on our results, we conclude that termite-associated Xylaria are specific for fungus-growing termites, without having specificity for lower taxonomic levels.

The pharmacokinetics of a single intravenous dose of metronidazole in pregnant patients.

The pharmacokinetics of a single 500 mg intravenous dose of metronidazole administered prophylactically to 16 women undergoing caesarean sections was studied. Seven cases satisfied the criteria for a one-compartment pharmacokinetic model, eight for a two-compartment model and one for a three compartment model. The mean elimination half-life of 6.9 (+/- 2.7)h and the plasma clearance rate of 1.19 (+/- 0.33)ml/min/kg was in close agreement with previous work on non-pregnant patients. Rapid transfer across the placental barrier was found, with effective concentrations in the arterial cord plasma.

[The Kleihauer-Bekte test in cases of suspected ectopic pregnancy]. / Die Kleihauer-Betke-toets in gevalle van verdagte ektopiese swangerskap.

Ectopic pregnancy is often difficult to diagnose, particularly in population groups that are prone to pelvic infections. In this study the use of the Kleihauer-Betke test for fetomaternal bleeding was examined in an attempt to improve diagnostic accuracy. The test was performed in 23 patients with ectopic pregnancies and in 19 control patients with normal intra-uterine pregnancies. Both groups were of more or less the same gestational age and parity. Whereas the test was positive in 31% of the control patients, indicating fetomaternal bleeding, it was positive in only 3 patients (13%) in the experimental group. The volume of fetomaternal blood in these 3 cases was 0,05 ml, 0,6 ml and 0.8 ml. These results indicate that the Kleihauer-Betke test is not a useful aid to diagnose cases of possible ectopic pregnancy, but confirm the fact that steps should be taken to prevent iso-immunization in susceptible cases.

Suppression of uterine activity with salbutamol before caesarean section.

In 32 patients undergoing emergency intrapartum caesarean section labour was suppressed with 250 micrograms salbutamol. The biochemical status of the neonates was compared with that of 15 controls. The initial results did not demonstrate a major difference between the two groups, but when only proven cases of fetal distress (H less than 7,25) in the two groups were compared, a significant improvement in the PO, pH and base deficit values in the umbilical vein as well as in the PO2 and pH values in the umbilical artery was noted in the group which had been given salbutamol. No major maternal side-effects were noted and this, together with the simplicity of the regimen, makes it a valuable temporizing measure in such cases.

The effectiveness of salbutamol as a suppressant of established labour.

The effectiveness of beta 2-adrenergic stimulants as suppressants of active labour is well known. This study examines the effects of salbutamol upon established labour in 32 patients undergoing emergency caesarean section. Twenty-five (78,1%) of the patients studied showed a sustained and effective suppression of labour after a bolus intravenous injection of 250 micrograms salbutamol. In 6 of the 7 remaining patients the parameters of uterine activity were also dramatically decreased, but because uterine activity recurred, it had to be further suppressed with an intravenous infusion. There was only 1 refractory case. No serious maternal or fetal side-effects were noted, and patient acceptance was good.

Advanced extra-uterine pregnancy: A case report.

In most cases of advanced extra-uterine pregnancy the fetus is surrounded by fetal membranes and varying quantities of amniotic fluid. It is, however, possible that the fetus may survive outside the amniotic sac intra-abdominally for varying periods of time. A case of extra-uterine pregnancy is presented where a normal infant was delivered 65 hours after rupture of the membranes.

Thrombocytopenic purpura in pregnancy. A case report.

A case of immune thrombocytopenic purpura in pregnancy is reported. An interesting facet of the treatment was the suppression of spontaneous labour while platelet concentrate was being prepared. This case clearly demonstrated that the maternal antibody titre in no way reflects the fetal status. The choice of delivery can therefor not be based upon scientific data. The possible use of the uranyl-labelled antibody method of determining antiplatelet antibodies may in future help to determine the best method of delivering these babies. A review of the literature clearly indicates that while maternal mortality has decreased, fetal loss in this condition is still significant, and that a multicentre study is needed to examine the best approach to this problem.

Pseudo-iniencephaly. A case report.

A case of congenital webbing with other congenital abnormalities is presented. Initial examination of the features of the case made a diagnosis of iniencephaly seem likely. However, further examination of the radiographs and the physical abnormalities demonstrated too few of the typical features, and the term pseudo-iniencephaly has been used to describe the case. The various aetiological possibilities are discussed, but it is clear that further research into webbing and its concomitant abnormalities would be necessary to provide the answers to the questions posed by this case.

Embryonal rhabdomyosarcoma. A case report.

A patient with embryonal rhabdomyosarcoma, who presented with septic criminal abortion, is discussed. The fact that the correct diagnosis was obscured by the unusual sequence of events is commented upon, and the need for critical evaluation of apparently clear-cut cases is demonstrated.