Distribution of variations in anatomy of the circle of Willis: results of a cadaveric study of the Malawian population and review of literature.

INTRODUCTION: the circle of Willis is an anatomical structure of clinical importance particularly in the evaluation of neurovascular diseases. Individuals show considerable variations in the anatomical configuration of the circle of Willis. A cross-sectional study was conducted to determine the distribution of morphological variations of the circle of Willis in Malawians and compare with other ethnic groups. METHODS: brains were collected from twenty-four recently deceased black Malawians during autopsy at Queen Elizabeth Central Hospital, a referral teaching hospital in Blantyre, Malawi and fixed in 10% buffered formalin. Digital images of the interpeduncular region (exposing the circle of Willis) were taken with an 18.4 megapixels camera from the base of the brain. Whole-circle and segmental parameters of the circle of Willis were assessed using the Osiris computer programme and classified based on a 22-type classification scheme. RESULTS: the following morphological variations were observed: hypoplasia, aplasia, asymmetry and accessory vessels. Typical circle of Willis was seen in 26% of the cases. Only six of the original twenty-two types were observed. Consistent with most previous studies, types 1, 3, 4, 6, 8 and 9 were common while types 10-22 were rare. Three variants not previously described in the original scheme (unilateral PcoA aplasia, AcoA duplication, and PcoA aplasia with contralateral PcoA hypoplasia) were observed in this study. CONCLUSION: anatomical variations of the circle of Willis in Malawians seem to be distributed in similar frequencies and patterns as in other more-diverse populations. Circle of Willis variants with potential predilection for atherogenesis and aneurysm formation exist in the Malawian population. These should be considered in clinical practice.

A preliminary investigation of the effects of labour inducing plant, Cissampelos mucronata, on the outcomes of pregnancy using rat models.

Background: The use of traditional remedies in pregnancy has been associated with bad obstetric outcomes including uterine rupture and foetal distress. These outcomes may ultimately lead to maternal and child mortality or morbidity. Few studies have been done to measure the effects of various herbs in pregnant women or a developing fetus. This study investigated the effects of the commonly used labour inducing plant, Cissampelos mucronata, on pregnancy outcomes using a rat model. Methods: Pregnant female rats were divided into 3 groups of 10 each. The first group was the control. The second group was treated with the aqueous extract of Cissampelos mucronata at mid-pregnancy. The third group was treated with Cissampelos mucronata close to full term. All the groups were left to give birth and outcomes were recorded. Results: Rats treated at mid-term had significantly low number of pups when compared to the control group as well as the close to term treated group (4.1 ± 0.54 vs. 6.4 ± 0.60; 6.2± 0.56). The mid-term treated rats had pups with significantly lower body weight when compared to the control and the close to term treated groups (3.73 ± 0.36g vs. 5.37 ± 0.16g; 4.27 ± 0.1g). The average gestation period was significantly short in the mid-term treated group when compared to the control and the close to term treated groups (18.16 ± 0.50 days vs. 20.40 ± 0.44 days; 20.12 ± 0.37 days). There were no uterus ruptures observed in all study groups 3 days after delivery. Conclusion: Administration of Cissampelos mucronata during pregnancy leads to early induction of labour.

The dynamics of adult neurogenesis in human hippocampus.

The phenomenon of adult neurogenesis is now an accepted occurrence in mammals and also in humans. At least two discrete places house stem cells for generation of neurons in adult brain. These are olfactory system and the hippocampus. In animals, newly generated neurons have been directly or indirectly demonstrated to generate a significant amount of new neurons to have a functional role. However, the data in humans on the extent of this process is still scanty and such as difficult to comprehend its functional role in humans. This paper explores the available data on as extent of adult hippocampal neurogenesis in humans and makes comparison to animal data.