Impact of varying maternal dietary folate intake on cerebellar cortex histomorphology and cell density in offspring rats.

The cerebellum has a long, protracted developmental period that spans from the embryonic to postnatal periods; as a result, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is crucial for foetal and early postnatal brain development; however, its effects on cerebellar growth and development are unknown. The aim of this study was to examine the effects of maternal folate intake on the histomorphology and cell density of the developing cerebellum. Twelve adult female rats (rattus norvegicus) were randomly assigned to one of four premixed diet groups: standard (2 mg/kg), folate-deficient (0 mg/kg), folate-supplemented (8 mg/kg) or folate supra-supplemented (40 mg/kg). The rats started their diets 14 days before mating and consumed them throughout pregnancy and lactation. On postnatal days 1, 7, 21 and 35, five pups from each group were sacrificed, and their brains were processed for light microscopic analysis. Histomorphology and cell density of the external granule, molecular, Purkinje and internal granule layers were obtained. The folate-deficient diet group had smaller, dysmorphic cells and significantly lower densities of external granule, molecular, Purkinje and internal granule cells. Although the folate-enriched groups had greater cell densities than the controls, the folate-supplemented group had considerably higher cell densities than the supra-supplemented group. The folate supra-supplemented group had ectopic Purkinje cells in the internal granule cell layer. These findings imply that a folate-deficient diet impairs cellular growth and reduces cell density in the cerebellar cortex. On the other hand, folate supplementation increases cell densities, but there appears to be an optimal dose of supplementation since excessive folate levels may be detrimental.

Maternal usage of varying levels of dietary folate affects the postnatal development of cerebellar folia and cortical layer volumes.

OBJECTIVE: The cerebellum has a long, protracted developmental period; therefore, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is an essential nutrient in fetal and postnatal brain development, and its supplementation during pregnancy is widely recommended. This study aimed to describe the effects of maternal folate intake on postnatal cerebellum development. METHODS: Twelve adult female Rattus norwegicus (6-8 weeks old) rats were randomly assigned to one of four groups and given one of four premixed diets: a standard diet (2 mg/kg), a folate-deficient (folate 0 mg/kg), folate-supplemented (8 mg/kg), or folate supra-supplemented (40 mg/kg). The rats began consuming their specific diets 14 days before mating and were maintained on them throughout pregnancy and lactation. Five pups from each group were sacrificed, and their brains processed for light microscopic examination on postnatal days 1, 7, 21, and 35. The data gathered included the morphology of the cerebellar folia and an estimate of the volume of the cerebellar cortical layer using the Cavalieri method. RESULTS: Folia of the folate-supplemented and supra-supplemented groups were thicker and showed extensive branching with sub-lobule formation. The folate-deficient diet group's folia were smaller, had more inter-folial spaces, or fused. When compared to the folate-deficient group, the volumes of the cerebellum and individual cerebellar cortical layers were significantly larger in the folate-supplemented and supra-supplemented groups (p<0.05). CONCLUSION: Folate supplementation during pregnancy and lactation improves the degree and complexity of the cerebellar folia and the volumes of individual cerebellar cortical layers.

Do Mesenchymal Stem Cells Influence Keloid Recurrence?

Introduction: Mesenchymal stem cells (MSCs) have been postulated by a number of authors to be the precursor cells of fibroblasts and myofibroblasts in keloids. They have been seen as a regenerative pool that ensures a steady supply of cells. The objective of our study was to determine MSCs in keloids and normal skin as a determinant of keloid recurrence. Methods: This was a longitudinal prospective study in which patients with keloid excisions of their specimens analyzed for MSC. A control group of patients matched for age, sex, and body-mass index (BMI) with no history of keloids admitted for elective surgical procedures had their skin samples taken and also analyzed for MSCs. Data collected were analyzed and compared using Student's t, x 2, and Fisher's exact t tests. Results: A total of 61 patients with keloids and a control group of 32 patients were recruited. The male:female ratio was 1:2 and mean age 29.5 and 29.7 years for keloids and controls, respectively. Patients with recurrent keloids had a mean density of 841.4 MSCs/g compared to 578 MSCs/g of tissue for those with no recurrence and 580 MSCs/g for patients with normal skin. Recurrent keloids had a significantly higher percentage of MSCs than those without. Conclusion: Keloids compared to normal skin had a higher percentage of MSCs, with recurrent keloids demonstrating an even higher count, a possible indicator that MSCs might correlate with severity of keloid disease and recurrence.

The Unusual High Origin Radial Artery in a Black Kenyan Population: A Cadaveric Study.

Background: The anatomy of the radial artery draws great interests among anatomists for its frequent involvement in variations. Equally, these variations have gained significant attention from clinicians because of the preference to use the radial artery for catheterization. The commonest of radial artery variations involve its site of origin. In published literature, data on this variations exist, but the prevalence of such variations in a Kenyan population has hitherto been unknown. Methods: Sixty-two upper limbs from 50 formalin-fixed cadavers were studied during dissection in the Department of Human Anatomy, University of Nairobi. Results: Fifty-four (87.1%) radial arteries arose within the cubital fossa, while eight (12.9%) had a high origin. Out of the eight high arteries, two (3.2%) branched off from the axillary artery, another two (3.2%) were branches of the proximal third of the brachial artery and four (6.5%) arose from the middle third of the brachial artery. The high origin radial arteries were more common on the right upper limbs (5 out of the 8 cases). Both axillary and brachial origins were seen bilaterally. Conclusion: The present study details important variations in the anatomy of the radial artery in a Kenyan population. With the radial artery being utilized during clinical, surgical and radiological interventions so frequently, an increased understanding and anticipation of such topographic variances is paramount.

Age related effects of selective and non-selective COX-2 inhibitors on bone healing.

INTRODUCTION: Fractures are increasing worldwide and with an aging population, are frequent in the elderly. The healing of fractures progresses through various phases including the inflammatory stage. Aging is associated with slower healing and the use of non steroidal anti-inflammatory drugs (NSAIDs) may interrupt bone healing processes. We designed a study to compare the effect of diclofenac and celecoxib on fracture callus histomorphometry in a rat model of different age groups. METHODS: Using 5 and 15 month old rats, fractures were induced on the left tibia and the animals allocated to receive one of the drugs. Animals were sacrificed at day 21 and 42 and the fracture callus harvested for processing and histological evaluation. Tissue proportions and histological grades were determined and compared across the groups. RESULTS: Across all groups, the histological grade increased with time and animals in the young diclofenac group had the highest grade at day 42 (p = 0.004). The proportion of bone increased in all groups and was highest in the young diclofenac group at day 21 and day 42 (p = 0.003). Post hoc analysis showed that the young celecoxib and old celecoxib groups had the least proportion of bone (p = 0.032 and p = 0.003). The proportion of cartilage reduced in all groups at both time points. CONCLUSION: Celecoxib was associated with lower histological grade and lower proportion of bone in older animals. We urge for caution regarding the use of celecoxib in older people for the management of pain associated with fractures. Diclofenac may be a better option in this group.

Standardized statement for the ethical use of human cadaveric tissues in anatomy research papers: Recommendations from Anatomical Journal Editors-in-Chief.

Human cadaveric donors are essential for research in the anatomical sciences. However, many research papers in the anatomical sciences often omit a statement regarding the ethical use of the donor cadavers or, as no current standardized versions exist, use language that is extremely varied. To rectify this issue, 22 editors-in-chief of anatomical journals, representing 17 different countries, developed standardized and simplified language that can be used by authors of studies that use human cadaveric tissues. The goal of these editor recommendations is to standardize the writing approach by which the ethical use of cadaveric donors is acknowledged in anatomical studies that use donor human cadavers. Such sections in anatomical papers will help elevate our discipline and promote standardized language use in others non anatomy journals and also other media outlets that use cadaveric tissues.

Anatomical Variations in the Origin of the Lumbar Artery: A Cadaveric Study Augmented by CT Findings.

BACKGROUND: Anatomical variations of lumbar arteries predispose them to iatrogenic injury during endovascular intervention or surgery. Due to limited morphological data on lumbar arteries in our setting, we aimed to determine their variant anatomy among Kenyans. METHODS: We performed the study on 90 cadaveric specimens and 120 computed tomography (CT) scans. Cadavers were dissected to expose the aorta and the lumbar arteries emerging from them. The number, origins, location relative to the vertebral bodies, and relations to aortic bifurcation were determined in cadavers and CT scans. Data were analyzed using SPSS (version 21.0). RESULTS: On average, 3 (3/90 [3.3%]), 4 (63/90 [70%]) or 5 (24/90 [26.7%]) pairs of lumbar arteries were observed among the cadaveric specimens, whereas 4 (100/120 [83.3%]) or 5 (20/120 [16.7%]) pairs were observed in CTs. Differences in the number of pairs observed in the cadaveric versus CT study were not statistically significant (P = .542). There were no sex differences in the number of lumbar artery pairs observed in CT scans (P = .178). The first 3 lumbar artery pairs had a single-origin, whereas the fourth lumbar artery had a common-stem origin. The first, second, and third lumbar arteries mostly originated at the upper third of their respective vertebral bodies. The fourth lumbar artery predominantly originated at the lower third. CONCLUSION: Our study's findings show unique variation in the lumbar arteries' relation to the vertebral bodies and the distances between artery pairs. LEVEL OF EVIDENCE: IV (cross-sectional study). CLINICAL RELEVANCE: Variations in the anatomy of the lumbar arteries should be taken into consideration, especially in surgical or interventional procedures to avoid inadvertent injury of the vessels.

Laparoscopic surgery during the COVID-19 pandemic: detection of SARS-COV-2 in abdominal tissues, fluids, and surgical smoke.

BACKGROUND: There are still concerns over the safety of laparoscopic surgery in coronavirus disease 2019 (COVID-19) patients due to the potential risk of viral transmission through surgical smoke/laparoscopic pneumoperitoneum. METHODS: We performed a systematic review of currently available literature to determine the presence of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) in abdominal tissues or fluids and in surgical smoke. RESULTS: A total of 19 studies (15 case reports and 4 case series) comprising 29 COVID-19 patients were included. The viral RNA was positively identified in 11 patients (37.9%). The samples that tested positive include the peritoneal fluid, bile, ascitic fluid, peritoneal dialysate, duodenal wall, and appendix. Similar samples, together with the omentum and abdominal subcutaneous fat, tested negative in the other patients. Only one study investigated SARS-COV-2 RNA in surgical smoke generated during laparoscopy, reporting negative findings. CONCLUSIONS: There are conflicting results regarding the presence of SARS-COV-2 in abdominal tissues and fluids. No currently available evidence supports the hypothesis that SARS-COV-2 can be aerosolized and transmitted through surgical smoke. Larger studies are urgently needed to corroborate these findings.

Does Keloid Histology Influence Recurrence?

ABSTRACT: Keloids are fibroproliferative disorders characterized by high recurrence rates, with few factors known to influence the same. We conducted a study to determine whether keloid histology influences recurrence. This was a prospective longitudinal study to determine whether histopathological parameters of keloid influence recurrence. Patients with keloids managed by surgical excision were followed up at Kenyatta National Hospital between August 2018 and July 2020. The excised keloids were processed for histology using hematoxylin,/eosin, Masson, and trichrome stains. The slides were analyzed for inflammatory cells, fibroblasts, and capillary density using the hot spot technique and correlated to keloid recurrence. Postoperative follow-up was for a minimum of 1 year. A total of 90 patients with 104 keloids were recruited in the study. Overall keloid recurrence rate was 28.6%. There was a correlation between the absolute count of more than 50 per High power field of lymphocytes, fibroblasts, and macrophages with recurrence of the disease. The sensitivity and specificity for the above parameters were lymphocytes 48% and 81%, macrophages 57% and 83%, mast cells 32% and 33%, and fibroblasts 41% and 91%, respectively. There was no correlation between mast cells and vascularity status with recurrence. Routine histology should, therefore, be performed to determine these parameters. Close monitoring and second-line therapy should be considered for patients with elevated macrophages and/or lymphocytes so as to reduce the risk of recurrence.

Conceptual framework for establishing the African Stroke Organization.

Africa is the world's most genetically diverse, second largest, and second most populous continent, with over one billion people distributed across 54 countries. With a 23% lifetime risk of stroke, Africa has some of the highest rates of stroke worldwide and many occur in the prime of life with huge economic losses and grave implications for the individual, family, and the society in terms of mental capital, productivity, and socioeconomic progress. Tackling the escalating burden of stroke in Africa requires prioritized, multipronged, and inter-sectoral strategies tailored to the unique African epidemiological, cultural, socioeconomic, and lifestyle landscape. The African Stroke Organization (ASO) is a new pan-African coalition that brings together stroke researchers, clinicians, and other health-care professionals with participation of national and regional stroke societies and stroke support organizations. With a vision to reduce the rapidly increasing burden of stroke in Africa, the ASO has a four-pronged focus on (1) research, (2) capacity building, (3) development of stroke services, and (4) collaboration with all stakeholders. This will be delivered through advocacy, awareness, and empowerment initiatives to bring about people-focused changes in policy, clinical practice, and public education. In the spirit of the African philosophy of Ubuntu "I am because we are," the ASO will harness the power of diversity, inclusiveness, togetherness, and team work to build a strong, enduring, and impactful platform for tackling stroke in Africa.

Arterial Thrombosis in Coronavirus Disease 2019 Patients: A Rapid Systematic Review.

BACKGROUND: Emerging evidence suggests that severe form of coronavirus disease 2019 (COVID-19) is mediated, in part, by a hypercoagulable state characterized by micro- and macro-vascular thrombotic angiopathy. Although venous thrombotic events in COVID-19 patients have been well described, data on arterial thrombosis (AT) in these patients is still limited. We, therefore, conducted a rapid systematic review of current scientific literature to identify and consolidate evidence of AT in COVID-19 patients. METHODS: A systematic search of literature was conducted between November 1, 2019, and June 9, 2020, on PubMed and China National Knowledge Infrastructure to identify potentially eligible studies. RESULTS: A total of 27 studies (5 cohort, 5 case series, and 17 case reports) describing arterial thrombotic events in 90 COVID-19 patients were included. The pooled incidence of AT in severe/critically ill intensive care unit-admitted COVID-19 patients across the 5 cohort studies was 4.4% (95% confidence interval 2.8-6.4). Most of the patients were male, elderly, and had comorbidities. AT was symptomatic in >95% of these patients and involved multiple arteries in approximately 18% of patients. The anatomical distribution of arterial thrombotic events was wide, occurring in limb arteries (39%), cerebral arteries (24%), great vessels (aorta, common iliac, common carotid, and brachiocephalic trunk; 19%), coronary arteries (9%), and superior mesenteric artery (8%). The mortality rate in these patients is approximately 20%. CONCLUSIONS: AT occurs in approximately 4% of critically ill COVID-19 patients. It often presents symptomatically and can affect multiple arteries. Further investigation of the underlying mechanism of AT in COVID-19 would be needed to clarify possible therapeutic targets.

Intracranial hemorrhage in coronavirus disease 2019 (COVID-19) patients.

BACKGROUND: Emerging evidence suggests that a subset of coronavirus disease 2019 (COVID-19) patients may present with or develop cerebrovascular disease during the course of hospitalization. Whereas ischemic stroke in COVID-19 patients has been well described, data on intracranial hemorrhage (ICH) in these patients is still limited. We, therefore, conducted a rapid systematic review of current scientific literature to identify and consolidate evidence of ICH in COVID-19 patients. METHODS: A systematic search of literature was conducted between November 1, 2019, and August 14, 2020, on PubMed and China National Knowledge Infrastructure (CNKI) to identify eligible studies. RESULTS: A total of 23 studies describing ICH in 148 COVID-19 patients were included. The pooled incidence of ICH in COVID-19 patients was 0.7% (95% CI 0.5-0.9), with low levels of inter-study heterogeneity observed (I2 = 33.6%, Cochran's Q = 12.05, p = 0.149). Most of the patients were elderly male patients (65.8%) with comorbidities, the most common being systemic hypertension (54%). Hemorrhage involving multiple cranial compartments was reported in 9.5% of cases. Single compartments were involved in the rest, with intraparenchymal hemorrhage (IPH) being the most common variety (62.6%) and intraventricular hemorrhage (IVH) the least common (1.4%). Half of these patients were on some form of anticoagulation. Overall, the mortality rate in the COVID-19 patients with ICH was about 48.6%. CONCLUSION: Although relatively uncommon among COVID-19 patients, ICH is associated with a high mortality rate. Early identification of patients at risk of developing ICH, particularly with comorbid conditions and on anticoagulant therapy, may be important to improve outcomes.

Coronavirus Disease 2019 (COVID-19) set to increase burden of atherosclerotic cardiovascular disease in Kenya.

The coronavirus disease 2019 (COVID-19), first reported in Kenya on March 13, 2020, is spreading rapidly. As of 30th June 2020, over 6,190 cases had been reported with a case fatality of 3.2%. Previous Coronavirus outbreaks have been associated with a significant burden of Cardiovascular disease. For COVID-19, however, there has been no direct reference to potential long-term cardiovascular effects, especially in Africa where atherosclerotic diseases are an emerging challenge. This article, therefore, aims at describing possible long-term effects on the burden of atherosclerotic disease among Kenyans. Available data indicate that COVID-19 and cardiovascular disease share pathomechanisms and risk factors which include ACE2 receptor invasion and renin-angiotensin system signaling, oxidative stress, systemic inflammation, and endothelial dysfunction. Further, SAR-COV-2 infection causes dyslipidemia, dysglycemia, kidney, and liver disease. These mechanisms and diseases constitute risk factors for the initiation, progression, and complications of atherosclerosis. In Kenya, the common risk factors for atherosclerotic cardiovascular disease, and COVID-19 comprising Hypertension, Diabetes Mellitus, Obesity, Cigarette Smoking, Respiratory Tract Infections, Pulmonary Thromboembolism, Chronic Obstructive Pulmonary Disease, and Renal disease are not uncommon and continue to increase. In essence, the prevalence of the common risk factors/comorbidities, between COVID-19 and CVD occurrence of ACE2 receptors on the endothelium, and hence pathomechanisms of SARS-COV-2 infection imply that COVID-19 may increase the burden of atherosclerotic disease in Kenya. All due care should be taken, to prevent and effectively manage the disease, to avert an imminent epidemic of atherosclerotic disease.

Valve distribution of the popliteal vein: A structural basis for deep venous thrombosis?

OBJECTIVE: To describe the relationship between number and distribution of valves. METHODS: Sixty-six popliteal vein specimens were used for the study after routine dissection at the Department of Human Anatomy, University of Nairobi. The extents of the popliteal vein were identified at the adductor hiatus and soleal arch, cut at these points and then longitudinally sliced open. The number and distribution of valves were then recorded. Data were presented using photomacrographs and tables. RESULTS: The median number of valves was 1 (mean 0.8; range 0-2), with the lower part of the popliteal vein as the most consistent valve position. Most striking was the valve absence noted in 27 (41%) of the veins. CONCLUSION: These findings suggest that a significant proportion of popliteal veins do not have valves thus providing a credible structural link that may predispose the popliteal vein to deep venous thrombosis in the study population.

Morphometric Dimensions of the Calcaneus.

Calcaneal morphometric dimensions influence surgical treatment plans after injury. These dimensions display population heterogeneity, and there is a paucity of data in the setting of our hospital in Kenya. Further, estimation of calcaneal dimensions during reconstruction in comminuted fractures can be difficult. This cross-sectional study therefore aims to determine equations for estimation of these dimensions as well as provide local data. Sixty-four bilateral calcanei of adult indigenous Kenyans were obtained from the National Museum of Kenya and measured for maximum anteroposterior length, maximum height, cuboidal facet height, body height, and load arm length. The data were coded into SPSS software, and means were calculated. Paired t tests, independent t tests, and Pearson correlation tests were done, and linear regression model equations were developed. Data are presented using tables. In millimeters, the mean right and left values, respectively, were as follows: maximum anteroposterior length, 36.1063 and 35.3047; maximum height, 68.958 and 68.266; cuboidal facet height, 27.815 and 27.841; body height, 47.94 and 48.98; and load arm length, 18.83 and 17.93. Paired and independent t tests did not reveal statistically significant difference between the variables based on side or sex. Pearson correlational tests between the maximum length on each side and other variables revealed strong positive correlations, apart from the maximum width and load arm length on both sides. All correlational R2 values were statistically significant, apart from that of the maximum width bilaterally. The calcaneus in our setting also showed markedly reduced values compared with other populations. These findings, and the proposed equations we developed, may be considered in local calcaneal reconstruction.

The Relation of the Extracranial Spinal Accessory Nerve to the Sternocleidomastoid Muscle and the Internal Jugular Vein.

The spinal accessory nerve (SAN) exhibits variant anatomy in its relation to the internal jugular vein (IJV) as well as the sternocleidomastoid muscle (SCM). These variations are important in locating the nerve during surgical neck procedures to avoid its inadvertent injury. These variations, however, are not conserved among different populations and data from the Kenyan setting are partly elucidated. This study, therefore, aims to determine the variant anatomical relationship of the SAN to the SCM and IJV in a select Kenyan population. Forty cadaveric necks were studied bilaterally during routine dissection and the data collected were analyzed using SPSS version 21. Means and modes were calculated for the point of entry of the SAN into the posterior triangle of the neck as well as for its relation to the SCM. Side variations for both of these were analyzed using Student's t -test. Data relating the SAN to the IJV were represented in percentages and side variations were analyzed using the chi-square test. The SAN point of entry into the posterior triangle of the neck was 5.38 cm (3.501-8.008 cm) on the left side and 5.637 cm (3.504-9.173 cm) on the right side ( p = 0.785) from the mastoid process. The nerve perforated the SCM in four cases (10%) on the left side and in eight cases (20%) on the right ( p = 0.253). The SAN lay predominantly medial to the IJV on both sides of the neck, 87.5% on the left side of the neck versus 82.5% on the right ( p = 0.831). In conclusion, the variant relation of the SAN to the IJV and SCM as observed in this setting is an important consideration during radical neck procedures and node biopsies.

Pattern of stroke in a rural Kenyan hospital.

Background: The pattern of stroke in rural population differs from that in urban ones. Although there are many studies on this condition in sub-Saharan Africa, few studies about stroke pattern in a Kenyan rural area exist.. This study therefore aims at describing the characteristics of stroke in a rural Kenyan hospital. Patients and Methods: The study was conducted on 227 consecutive patients admitted with a World Health Organization (WHO) diagnosis of stroke in Kangundo Hospital, a level IV facility in Machakos, Eastern Kenya, between April 2015 and September 2016. The sub-type and anatomical distribution of stroke as well as the age, gender of the patients were recorded prospectively. Diagnosis was made through physical neurological examination and confirmed by Computerized Tomography (CT) scan imaging. Only those with complete bio-data, past medical and social history, clinical and physical findings of the patients and imaging results were included. The data were entered into a pre-formatted questionnaire, analysed for means, standard deviations and frequencies, and are presented in tables and bar charts. Results: Out of 3200 medical admissions, 227 (7.09%) had a confirmed diagnosis of stroke. Ischaemic stroke was more common (67.4%) than haemorrhagic stroke (32.6%). It affected mainly the anterior circulation, especially the middle cerebral artery (39%). The mean age of patients was 68.8 years, (Range 32-96). It was more common in females (62%) than in males (38%). Hypertension was the most common (74%) risk factor followed by alcohol abuse (63%), tobacco smoking (48%) and diabetes mellitus (42%). Conclusion: Ischaemic stroke was the more common major cause of morbidity in the rural hospital studied in Kenya. It occurred most commonly among elderly females, with the most frequent comorbidities being hypertension. In addition, modifiable lifestyle factors like alcohol abuse and cigarette smoking contributed to the prevalence; hence we recommend the control of blood pressure and glucose as well as lifestyle modification to reduce the scourge in our studied population.

Stroke, cerebrovascular diseases and vascular cognitive impairment in Africa.

With increased numbers of older people a higher burden of neurological disorders worldwide is predicted. Stroke and other cerebrovascular diseases do not necessarily present with different phenotypes in Africa but their incidence is rising in tandem with the demographic change in the population. Age remains the strongest irreversible risk factor for stroke and cognitive impairment. Modifiable factors relating to vascular disease risk, diet, lifestyle, physical activity and psychosocial status play a key role in shaping the current spate of stroke related diseases in Africa. Hypertension is the strongest modifiable risk factor for stroke but is also likely associated with co-inheritance of genetic traits among Africans. Somewhat different from high-income countries, strokes attributed to cerebral small vessel disease (SVD) are higher >30% among sub-Saharan Africans. Raised blood pressure may explain most of the incidence of SVD-related strokes but there are likely other contributing factors including dyslipidaemia and diabetes in some sectors of Africa. However, atherosclerotic and cardioembolic diseases combined also appear to be common subtypes as causes of strokes. Significant proportions of cerebrovascular diseases are ascribed to various forms of infectious disease including complications of human immunodeficiency virus. Cerebral SVD leads to several clinical manifestations including gait disturbance, autonomic dysfunction and depression. Pathological processes are characterized by arteriolosclerosis, lacunar infarcts, perivascular spaces, microinfarcts and diffuse white matter changes, which can now all be detected on neuroimaging. Except for isolated cases of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy or CADASIL, hereditary arteriopathies have so far not been reported in Africa. Prevalence estimates of vascular dementia (2-3%), delayed dementia after stroke (10-20%) and vascular cognitive impairment (30-40%) do not appear to be vastly different from those in other parts of the world. However, given the current demographic transition in both urban and rural settings these figures will likely rise. Wider application of neuroimaging modalities and implementation of stroke care in Africa will enable better estimates of SVD and other subtypes of stroke. Stroke survivors with SVD type pathology are likely to have low mortality and therefore portend increased incidence of dementia.

Placental Structure in Preterm Birth Among HIV-Positive Versus HIV-Negative Women in Kenya.

BACKGROUND: Preterm birth (PTB) is a major cause of infant morbidity and mortality in developing countries. Recent data suggest that in addition to Human Immunodeficiency Virus (HIV) infection, use of antiretroviral therapy (ART) increases the risk of PTB. As the mechanisms remain unexplored, we conducted this study to determine whether HIV and ART were associated with placental changes that could contribute to PTB. SETTING: We collected and evaluated placentas from 38 HIV-positive women on ART and 43 HIV-negative women who had preterm deliveries in Nairobi, Kenya. METHODS: Anatomical features of the placentas were examined at gross and microscopic levels. Cases were matched for gestational age and compared by the investigators who were blinded to maternal HIV serostatus. RESULTS: Among preterm placentas, HIV infection was significantly associated with thrombosis (P = 0.001), infarction (P = 0.032), anomalies in cord insertion (P = 0.02), gross evidence of membrane infection (P = 0.043), and reduced placental thickness (P = 0.010). Overall, preterm placentas in both groups were associated with immature villi, syncytial knotting, villitis, and deciduitis. Features of HIV-positive versus HIV-negative placentas included significant fibrinoid deposition with villus degeneration, syncytiotrophoblast delamination, red blood cell adhesion, hypervascularity, and reduction in both surface area and perimeter of the terminal villi. CONCLUSIONS: These results imply that HIV infection and/or ART are associated with morphological changes in preterm placentas that contribute to delivery before 37 weeks. Hypervascularity suggests that the observed pathologies may be attributable, in part, to hypoxia. Further research to explore potential mechanisms will help elucidate the pathways that are involved perhaps pointing to interventions for decreasing the risk of prematurity among HIV-positive women.

Geometric features of vertebrobasilar arterial system in adult black Kenyans / Características geométricas del sistema arterial vertebrobasilar en kenianos negros adultos

Geometric features of vertebrobasilar system influence occurrence of posterior circulation atherosclerosis, aneurysms, stroke and neuroradiological procedures. These features show ethnic variation, but data from black Africans in Sub Saharan Africa are scarce. This study aimed to describe geometric features of vertebrobasilar system in a black Kenyan population. It was a descriptive cadaveric study at Department of Human Anatomy, University of Nairobi. One hundred and seventy three formalin-fixed adult brains of individuals (99 male; 74 female; Age range 20 - 79) who had died of non cerebrovascular causes were studied. Level and angle of confluence of vertebral artery; diameter, length and bifurcation angles of basilar artery were measured. Data were analysed by SPSS version 21 for windows. The student t - test was used to determine the sex differences at 95 % confidence interval. Data are presented in macrographs, tables and bar charts. Confluence of vertebral arteries occurred at the sulcus bulbopontinus in 79.8 %; rostral to it in 11.5 % and caudal to it in 8.7 % of cases. Mean angle of vertebral artery confluence was 46.7º and 68.9º in males and females respectively (p£0.042). Mean length of the basilar artery was 26.8 mm; 26.3 mm in males and 27.1 mm in females (p=0.465). Mean diameter was 3.52 mm; 3.32 mm in males and 3.72 mm in females (p=0.002). The mean angle of basilar artery bifurcation was 120.3º ± 15.2; 99.3º ± 32.9 in males and 140.3º ± 16.1 in females (p=0.024). It was wider than 90º in 82.9 % of males and 95.9 % females (p=0.032). In 85 (49.1 %) it was wider than 120º. The vertebrobasilar system in the Kenyan population has geometric features that constitute risk factors for atherosclerosis. These features display sex dimorphism which may explain differences in prevalence of atherosclerosis and aneurysms. Neurosurgeons and neurologists should be aware of these differences. Individuals with risk prone geometric features should be followed up for atherosclerosis.

Las características geométricas del sistema vertebrobasilar influyen en la aparición de aterosclerosis en la circulación posterior, aneurismas, apoplejía, detectados durante procedimientos neurorradiológicos. Estas características muestran variación étnica, pero los datos de los africanos negros en el África Subsahariana son escasos. Este estudio tuvo como objetivo describir las características geométricas del sistema vertebrobasilar en una población negra de Kenia. Fue un estudio descriptivo cadavérico en el Departamento de Anatomía Humana de la Universidad de Nairobi. Se estudiaron 173 cerebros adultos (99 varones, 74 mujeres, rango de edad 20-79), fijados en formalina, de individuos que habían fallecido por causas no cerebrovasculares. Se midieron el nivel y ángulo de confluencia de la arteria vertebral, diámetro, longitud y bifurcación de la arteria basilar. Los datos fueron analizados por SPSS versión 21 para Windows. La prueba t de Student se utilizó para determinar las diferencias de sexo con un intervalo de confianza del 95 %. Los datos se presentan en macrografías, tablas y gráficos de barras. La confluencia de las arterias vertebrales se produjo en el surco bulbopontino en el 79,8 %; rostral al surco en 11,5 % y caudal al surco en 8,7 % de los casos. El ángulo medio de la confluencia de la arteria vertebral fue 46,70 y 68,90 en hombres y mujeres, respectivamente (p£0,042). La longitud media de la arteria basilar fue de 26,8 mm; 26,3 mm en hombres y 27,1 mm en mujeres (p=0,465). El diámetro promedio fue de 3,52 mm; 3,32 mm en hombres y 3,72 mm en mujeres (p=0,002). El ángulo medio de la bifurcación de la arteria basilar fue de 120,30 ± 15,2; 99.30 ± 32,9 en hombres y 140,30 ± 16,1en mujeres (p=0,024). Era más amplio que 90º. En un 82,9 % de los hombres y 95,9 % de las mujeres (p=0,032) se observó un ángulo más amplio que 90°. En 85 (49,1 %) fue más amplio que 120°. El sistema vertebrobasilar en la población de Kenia tiene características geométricas que constituyen factores de riesgo para la aterosclerosis. Estas características muestran dimorfismo sexual que puede explicar las diferencias en la prevalencia de aterosclerosis y aneurismas. Los neurocirujanos y los neurólogos deben tener en cuenta estas diferencias. Las personas con características geométricas propensas al riesgo deben ser seguidas por aterosclerosis.