Editorial: Lessons from a case of tubal twin pregnancy

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Editorial

Gallstone disease: a call to awareness in Subsaharan Afric

Aortic arch origin of the vertebral artery may have clinical implications

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Differential effects of chronic iron deficiency anaemia on junctional and labyrinthine zones of placenta in Sprague dawely rat

Iron deficiency anaemia causes adverse pregnancy outcome. Studies reveal its generalized effects on histomorphometry of the placenta, without details on specific zones nor effect of gestational age. These data are important for planning  intervention. This study was, therefore, designed to describe the histomorphometric changes associated with iron deficiency anaemia on placenta of albino rat. Fourty nine (49) Sprague – Dawely albino rats were randomly separated into experimental and control groups. The  experimental group was rendered anaemic by removing 1.5 ml of blood per bleed on five alternate days. Placentas were collected on gestational days 17, 19 and 21. Five cubic milimetre segments were fixed in 10 % buffered formaldehyde solution; dehydrated in ethanol and embedded in paraffin wax. Five micron thick sections were cut, deparaffinized and stained with Hematoxylin and Eosin. Micrographs were taken using Leica ICC 50 digital photomicrographic camera attached to a computer at magnification x40 and the thickness of the labyrinth and junctional zones measured. Student t- test was used to compare values for the   experimental and control groups. The labyrinth in the chronic anaemia group was thinner than in the control group at gestational days 17, 19 and 21. The junctional zone, on the other hand, was consistently thicker in anaemic than in the control animals. The difference in thickness of junctional zone varied with  gestational age. At gestational day 17, the zone was significantly thicker in the anaemic group (628.9 μ) than in the control (381 μ). On day 19 and 21, however, the difference was not statistically  significant. In conclusion, the effects of chronic iron deficiency anaemia on the labyrinth differ from those on the junctional zone of the placenta. This differential effect appears to depend on the function and gestational age. The decrease in thickness of the  labyrinth may be designed to maintain placental diffusion capacity while increased thickness of the junctional zone constitutes a compensatory physical and nutritional adaptation to hypoxia.Key words: placenta, labyrinthine, junctional zones, thickness, anaemia

Sex differences in diameter of the coronary sinus ostium: Correlation with weight of the heart

Diameter of the coronary sinus ostium is important in the designing of cannulation devices used in cardiac resynchronization  therapy and percutaneous mitral valve annuloplasty. Population variation of the diameter may account for the failure rate of these procedures. Studies of the coronary sinus ostium from African populations are scarce and altogether absent for Kenya. Therefore, this study aimed at determining sex differences in the diameter of coronary sinus ostium and its correlation with the weight of the heart. Seventy-four hearts of adult black Kenyans [43 male, 31 females; age range 20 – 70 years] obtained during autopsy at the Department of Human Anatomy, University of Nairobi, Kenya were weighed. The coronary sinus ostium was identified and its   transverse and supero-inferior diameters measured in millimeters. The measurements were analyzed using SPSS version 17. Sex  comparison was established using student’s t test. Association between diameter and heart weight was established using  Pearson’s correlation test and considered significant at a p-value of ≤0.05. Data were presented using scatter plots. Transverse and supero-inferior diameters of the ostium were 11.04±1.88mm and 9.50±1.80mm respectively. The mean diameter was 10.27 mm. These correlated positively with weight of the heart. When corrected for weight of the hearts, the transverse and supero-inferior diameters were larger in females (0.042 and 0.036 respectively) than in males (0.034 and 0.03 respectively). The diameter of coronary sinus ostium is larger in females and shows positive correlation with weight of the heart. These data should be considered during design and use of cardiac devices introduced through the coronary sinus.Key words: Coronary sinus, ostium, diameter, sex difference

Regional differences in the mural structure of the human coronary sinus

Regional differences in the mural structure of the coronary sinus are important in understanding its physico-mechanical properties and the basis for extent of atrial  fibrillation and ablation. These features are only scarcely reported. This study  therefore aimed at describing regional differences in the mural structure of coronary sinus among black Kenyans. This was a descriptive cross-sectional study on coronary sinuses from fifteen hearts obtained during autopsy on adult black  Kenyans at the Department of Human Anatomy, University of Nairobi.  Five-millimeter-long specimens were taken from the proximal, middle and terminal segments of the coronary sinus and processed routinely for paraffin embedding and sectioning. Seven-micron thick sections were stained with Masson’s Trichrome to demonstrate connective tissue and smooth muscle while Weigert’s Resorcin  Fuschin stain was used to demonstrate elastic fibres. The slides were examined  with a light microscope and photomicrographs taken with a high resolution digital camera. The results are presented in micrographs. The wall comprised three layers namely internal, middle and external. Regional differences were observed in the middle layer. In the proximal segment, there were concentrically oriented smooth muscles scattered within connective tissue. The middle and terminal segments on the other hand comprised cardiac muscle oriented both concentrically and  longitudinally. The muscle was separated by connective tissue rich in elastic fibres and abundant vasa vasora. The external layer comprised connective tissue. In conclusion the middle layer of the wall of the coronary sinus displays regional  differences. The smooth muscle at the proximal segment may confer contractility to enhance blood flow while the cardiac muscle in the other segments enables it to function in synchrony with the right atrium during atrial systole. The complex  arrangement of circular and longitudinal muscle facilitates blood flow and may also constitute a sphincter mechanism.Keywords: Coronary sinus, regional differences, smooth and cardiac muscl

Comparative regional morphometric changes in human uterine artery before and during pregnancy

Introduction Uterine artery undergoes structural modifications at different physiologic states. It is expected that due to its unique course, hemodynamic stresses in the vessel would vary resulting in differences in arterial dimensions. The objective of this study was to investigate regional morphometric changes in the human uterine artery. Methods Twenty four uterine arteries (12 each from non-gravid uteri and gravid uteri) were obtained during autopsy after ethical approval from women aged between 21 to 47 years. Sections from proximal, middle and distal segments of the artery taken within 72 hours were processed for paraffin embedding, sectioned and stained with Mason’s Trichrome. Micrographs of the slides were analyzed using Scion Image Multiscan software. Data were entered into and analyzed with Statistical Programme for Social Sciences. Results The pregnancy related increase in diameter and wall thickness are most pronounced in the proximal segment. In the distal segment, however, wall thickness reduces significantly (p<0.05). Intimal thickness was lesser in pregnancy compared to non-gravid state in all the segments. Conclusion Regional morphometric changes in the uterine artery during pregnancy may be designed to regulate blood flow to the uterus and placenta during pregnancy.Pan African Medical Journal 2012; 13:3

Non muscle cells in the tunica media of the aorta

Knowledge of cellular composition of aortic tunica media is important to improve understanding of aortic pathology. The aorta of 6 healthy male goats was studied by electron microscopy to elucidate cell types within the tunica media. Glutaraldehyde fixed specimens were processed for durcupan embedding and sectioning, stained with uranyl acetate, counterstained with lead citrate and ultrathin sections examined at high magnification. Two non muscle cells were observed, one resembling fibroblasts and the other with features of macrophages. It is concluded that these cells are normal constituents of the aortic media, involved in synthesis of extracellular matrix and immunosurveillance respectively. Their involvement in repair and disease process needs further investigation.Keywords: tunica media, aorta, fibroblast, macrophage

Cardiovascular causes of death in an east African country: An autopsy study

Background: The spectrum of cardiovascular diseases varies between countries. Data from east Africa is scarce, but important in formulating disease management strategies. The aim of this study was to describe the spectrum of cardiovascular causes of death in Kenya. Methods: One hundred and thirty four autopsy cases of cardiovascular related deaths examined at the Department of Human Anatomy, University of Nairobi, from December 2005 to November 2009 were analyzed for disease type, age and gender distribution. Only cases in which cardiovascular disease was the most likely cause of death were included. Data was analyzed using SPSS version 15.0 for Windows and presented using tables and bar graphs. Results: Cardiovascular causes comprised 13.2% of all autopsy cases. Common conditions included myocardial infarction (18.7%), cardiomyopathy (17.2%), subarachnoid hemorrhage (15.7%), pulmonary thromboembolism (14.2%), ruptured aortic aneurysm (11.2%) and hypertensive heart disease (9.0%). Infective pericarditis and rheumatic heart disease comprised 7.5% and 6.7%, respectively. Mean age was 50.4 years, peaking at 40-60 years, with 56.7% aged 50 years and younger. Male: female ratio was 2.7:1. Conclusions: Cardiovascular disease contributes more than 13% of overall mortality in Kenya. Myocardial infarction is the commonest, while rheumatic heart disease is the rarest. It is predominantly male and mainly affects those aged under 50 years. This suggests that non-communicable diseases, while predominant, overlap with infectious conditions as causes of cardiovascular mortality. A search for, and the prevention of, risk factors, combined with prudent management of infection, are recommended. (Cardiol J 2011; 18, 1: 67-72

Effect of parity on endometrial glands in gravid rabbits

The uterus undergoes intense remodeling in pregnancy and subsequent involution in the postpartum period. One of the anatomical changes that occur in the gravid endometrium is increased glandular density. Parity has been shown to be protective against certain endometrial pathologies probably as a result of retained changes that take place during pregnancy. The findings of the current study may help provide the anatomical basis for different traits noted as the parity rises. Nine rabbits, California white breed (oryctolagus cuniculus), were obtained from a private farmer. The subjects were grouped as follows; primiparous rabbits in group 1, Para 1 and Para 2-3 in group 2, and Para >4 in group 3. Once successfully mated, they were housed in pens, fed, and given adequate supply of water. On day 18 of pregnancy, the rabbits were sacrificed and uterus harvested en bloc. Five-millimeter specimens were obtained from the uterus and processed for light microscopy. Quantification of endometrial glands and their size was done using the computer program Image J. Endometrial gland density was noted to decrease with a rise in parity such that the percentage proportion in the primigravid rabbit was 45% compared to that of 34% and 37.5% in the biparous and multiparous groups respectively. The endometrial gland duct circumference also increased as the parity increased. The present study reveals that a high parity is characterized by fewer, wider endometrial glands.Key words: Endometrial glands, Parity, Gravidit