Department of Anatomy
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Item Transcriptional responses of cancer cells to heat shock-inducing stimuli involve amplification of robust HSF1 binding(Nature Communications, 2023) Dastidar, S.G.; Parrello, D.; Koney, N.K.K.; et al.Responses of cells to stimuli are increasingly discovered to involve the binding of sequence-specific transcription factors outside of known target genes. We wanted to determine to what extent the genome-wide binding and function of A transcription factor is shaped by the cell type versus the stimulus. To do so, we induced the Heat Shock Response pathway in two different cancer cell lines with two different stimuli and related the binding of its master regulator, HSF1 to nascent RNA and chromatin accessibility. Here, we show that HSF1 binding patterns retain their identity between basal conditions and under different magnitudes of activation, so that common HSF1 binding is globally associated with distinct transcription outcomes. HSF1-induced increase in DNA accessibility was modest in scale but occurred predominantly at remote genomic sites. Apart from regulating transcription at existing elements, including promoters and enhancers, HSF1 binding amplified during responses to stimuli may engage inactive chromatin.Item Digital-palmar dermatoglyphics characteristics of patients living with schizophrenia in Ghana(Taylor and Francis Ltd., 2023) Majeed, N.S.; Arko-Boham, B.; Fiagbe, D.K.; et al.ABSTRACT The World Health Organization has acknowledged the gap in schizophrenia diagnoses and recommended further research to identify tools and biomarkers for the disease’s early detection. Because the skin and brain have a common ectodermal origin, dermatoglyphics are hypothesized to serve as a potential mirror for the identification of risks and characteristics of neuropsychiatric diseases. This study aimed to determine the digito-palmar dermatoglyphic patterns of schizophrenia patients in Ghana. Digito-palmar dermatoglyphics were obtained using a digital scanner, and the details studied. Individuals living with schizophrenia in Ghana were significantly characterized by low odds of vestige pattern in the hypothenar region, low odds of palmar creases 300, and high and low odds of radial loop (RL) and plain arch (PA) respectively at the finger patterns relative to the control group [OR (95% CI): vestige, 0.2 (0.06–0.69), P = 0.01; palmar creases 300, 0.1 (0.01–0.99), P = 0.049; PA, 0.4 (0.3–0.7), P < 0.001; RL, 1.9 (1.0–3.7), P = 0.044]. Individuals with schizophrenia were also characterized by low mean left-hand a-b ridge count and mean right hand atd angle compared to controls. These differences could be explored as a potential biomarker in diagnosing and early detection of schizophrenia in Ghanaians.Item Preliminary Findings on Self-Reported Voice Disorders in Urban Ghana: A Qualitative Description Study(Communication Disorders Quarterly, 2020-04-24) Amponsah, C.; Tettevi, G.; Gomado, L.; Heitzman, A.; Ziegler, A.This preliminary qualitative description study explored knowledge from urban Ghanaians about the nature and impact of their self-reported voice problem. Ten Ghanaians were screened for a self-reported voice disorder using the Voice Handicap Index–10 (VHI-10), and they also completed a structured interview with a speech-language therapist. Content analysis was completed from interview responses using quantification of data. Four out of 10 adult Ghanaians demonstrated high VHI-10 scores that indicated a self-reported voice disorder. Themes that emerged included a recurring problem with voice, multiple vocal impairments, limitations with participating in vocal activities, and other health problems. Lack of financial resources and little knowledge about voice disorders were barriers to accessing care. In summary, four adult Ghanaians with a self-reported voice disorder described multiple problems with their voice, limiting their participation in vocal activities. Implications of these preliminary findings include early identification and improving voice care access to avoid handicapping voice problems.Item Natural cocoa improves birth weight and viability of rabbit pups born to hypercholesterolemic mothers(Scientific African, 2020-02-21) Blay, R.M.; Arko-Boham, B.; Addai, F.K.Background: Maternal nutrition affects f etal growth and development in humans and ani- mals. Low birth weight can be caused by maternal hypercholesterolemia and is associated with increased risk of cardiovascular and other metabolic diseases later in adult life. Cocoa powder is rich in flavonoids and reduces plasma cholesterol levels. The study investigated the effect of hypercholesterolemia and natural cocoa intake during pregnancy on the birth weight and viability of rabbit pups. Methods: Hypercholesterolemic female New Zealand White rabbits were crossed with nor- mocholesterolemic males and randomly grouped into 2 ( n = 4 each). One group (HCC) received natural cocoa powder in their water in addition to high cholesterol diet during pregnancy, whereas the other (HC) received only water and high cholesterol diet. Litter size, birth weight and viability of pups were assessed and compared to a control group (NC) fed normal rabbit chow ( n = 2). Results: Average litter sizes of hypercholesterolemic rabbits (HC and HCC groups) were 3, whereas that of control group, NC was 5. Mean birth weight of pups was significantly lower in offspring of HC (42.73 g, SD 8.47) and HCC (50.0 g, SD 3.54) as compared to NC (73.0 g, SD 5.37). Mortality of offspring was highest in HC group (58.3%) as compared to 50% in HCC. Conclusions: Maternal hypercholesterolemia during pregnancy reduces litter size, birth weight and viability of offspring in rabbits and these deleterious effects may be minimized by regular intake of natural cocoa. Although further studies in humans need to be con- ducted, the results of this study suggest the need to monitor maternal cholesterol levels during pregnancy and the effects on pregnancy outcomes and health of offspring later in life.Item Laboratory Investigation of Suspected Cases of Chromosomal Abnormalities at the Korle-Bu Teaching Hospital.(Ghana Medical Journal, 1989-09) Tagoe, C.N.B.; Sowah, E.T.; Ayettey, A.S.; Engmann, N.N.L.Results of cytogenetic analysis carried out on 434 patients referred with clinical history suggestive of chromosomal abnormality showed a frequency of 27.4% (119/434) Of this number (119), 66.4% (79/119) had trisomy 21, made up of 71 regular Mongols [47,XX(Y), + 21] and 8 mosaics [46/47,XX(Y, +211. There was a male/female ratio of 3:2. Of the remaining 40, five were trisomy 13 and five trisomy 1& 26 of these had sex chromosome abnormality, out of which twenty were of the Turner's syndrome, three of intersex, two 0/ Klinefelter's syndrome, and one 47XYY. Among the 20 Turner syndrome patients fourteen were mosaic (46,XX/45,XO) and five homogeneous (45,XO) .. one patient had the 46,XY/45,XO pattern. Four structural chromosomal abnormalities were found. They consisted one each of 46,XX,D-,t(DqGq) +, 46,XXI46,XX,20q-(Philadelphia chromosome), 46,xx,q- and 46,XX/46,XX, typesItem Comparative study of atrial granule concentration at the nuclear pole of atrial cells of the insect - eating bat P@istrellus Pipistrellus and the Wistar rat.(Ghana Medical Journal, 1990-06) Ocansey, P.; Ayettey, A.S.; Tagoe, C.N.B.Atrail myocardial cells of the rat and the rat have been compared in regard to number and cementation of atrial granules at the nuclear pole. Morphologically the granules appear' the same, being dense spherical and membrane bound. By morphometric measure, natriuretic material is higer in concentration in the rat than in the bat, the percentage volumes being 6.5 in the rat and 3.5 in the bat. This difference is statistically significant at P<0.003. Actual counts of granules at the nuclear pole showed that, on the average, cellls of the two species have equal numbers of granules. The finding of lower volume concentration of granule material in the bat which weighs much less (6gm) than the rat (I70gm) shows that there.is Not always an inverse relationship between granule concentration and animal size or weight as had been thought aggregation of nuclear material was observed at the nuclear pole in a number of atrial cells of the bat the significance of this unusual finding is not clearItem Some Clinical Aspects(Ghana Medical Journal, 1965-09) Quartey, J.K.M.Item Preliminary report on clinical studies in young Ghanaians with Schistosorna haematobium infection with special reference to pyelographic and cystoscopic abnormalities(Ghana Medical Journal, 1963) Quartey, J.K.M.; Wolfe, M.S.Item A case of contracted bladder associated with chronic tuberculous peritonitis and treated by ileocystoplasty(Ghana Medical Journal, 1963) Quartey, J.K.M.Item Vasculogenesis drives pulmonary vascular growth in the developing chick embryo(Developmental Dynamics, 2005-05) Anderson-Berry, A.; O'Brien, E.A.; Bleyl, S.B.; Lawson, A.; Gundersen, N.; Ryssman, D.; Sweeley, J.; Dahl, M.J.; Drake, C.J.; Schoenwolf, G.C.; Albertine, K.H.Formation of the pulmonary vasculature has been described as occurring by outgrowth of existing vessels (angiogenesis), de novo formation of new vessels (vasculogenesis), or a combination of both processes. Uncertainty about the contribution of angiogenesis and vasculogenesis to pulmonary vascular formation is partly due to methodologic approaches. Evidence in favor of angiogenesis stems from studies that used vascular-filling methods. Such methods identify only directly continuous lumina. Evidence for vasculogenesis has been provided by the use of molecular markers of blood vessel endothelium. Use of both methods has not been combined in the same species, however. We hypothesized, based on published evidence from quail and mouse, that chick pulmonary vascular formation occurs by vasculogenesis. To test that hypothesis, we used vascular filling, serial section, and immunohistochemical methods to analyze the developing lungs of chick embryos from Hamburger and Hamilton stages 20 to 43. Vascular filling suggested that the lumen of the pulmonary arteries sprouted from the sixth pharyngeal arch arteries. However, serial sections and immunohistochemical localization of fetal liver kinase-1 protein, the receptor for vascular endothelial growth factor, showed that the pulmonary arterial tree formed from endothelial cell precursors and coalescence of isolated blood vessels in the mediastinal splanchnic mesenchyme centrally to the developing lung tissue distally. Pulmonary veins grew from the left atrium to the developing lungs. Pulmonary blood vessel formation occurred continuously throughout the embryonic period studied. Our results show that vasculogenesis is the main process by which the pulmonary vasculature forms in the developing chick embryo. © 2005 Wiley-Liss, Inc.Item Ubiquitous GFP expression in transgenic chickens using a lentiviral vector(Development, 2005-04) Chapman, S.C.; Lawson, A.; MacArthur, W.C.; Wiese, R.J.; Loechel, R.H.; Burgos-Trinidad, M.; Wakefield, J.K.; Ramabhadran, R.; Mauch, T.J.; Schoenwolf, G.C.We report the first ubiquitous green fluorescent protein expression in chicks using a lentiviral vector approach, with eGFP under the control of the phosphoglycerol kinase promoter. Several demonstrations of germline transmission in chicks have been reported previously, using markers that produce tissue-specific, but not ubiquitous, expression. Using embryos sired by a heterozygous male, we demonstrate germline transmission in the embryonic tissue that expresses eGFP uniformly, and that can be used in tissue transplants and processed by in situ hybridization and immunocytochemistry. Transgenic tissue is identifiable by both fluorescence microscopy and immunolabeling, resulting in a permanent marker identifying transgenic cells following processing of the tissue. Stable integration of the transgene has allowed breeding of homozygous males and females that will be used to produce transgenic embryos in 100% of eggs laid upon reaching sexual maturity. These results demonstrate that a transgenic approach in the chick model system is viable and useful even though a relatively long generation time is required. The transgenic chick model will benefit studies on embryonic development, as well as providing the pharmaceutical industry with an economical bioreactor.Item Rapid triple-labeling method combining in situ hybridization and double immunocytochemistry(Developmental Dynamics, 2004-06) Lopez-Sanchez, C.; Garcia-Martinez, V.; Lawson, A.; Chapman, S.C.; Schoenwolf, G.C.A new, rapid method is described for combining in situ hybridization and immunocytochemistry to define cell populations and to map three-dimensional movements of groups of labeled cells within developing chick embryos. The method allows fluorescently labeled cells to be followed in living embryos and subsequently detected as a permanent reaction product for detailed three-dimensional analysis by immunocytochemistry in histological serial sections. Cell identity can be ascertained using a specific riboprobe and in situ hybridization. With this approach, the movements of two groups of cells can be mapped simultaneously (using two different fluorescent trackers and, subsequently, two different chromogens for immunocytochemistry) to analyze relative movements within an embryo, and when combined with in situ hybridization with a specific riboprobe for cell identity, allows fate mapping studies to be conducted using molecular criteria, rather than solely at morphological/positional criteria. The improved method enables the investigator to extract substantially more information from individual embryos, maximizing the results obtained from labor-intensive fate mapping studies. © 2004 Wiley-Liss, Inc.Item New insights into critical events of avian gastrulation: Avian Gastrulation(Anatomical Record, 2001-04) Lawson, A.; Schoenwolf, G.C.The formation and progression of the primitive streak are key events of avian gastrulation. We examine these processes in detail, using various morphological approaches. We show that formation of the primitive streak occurs locally at the caudal midline of the area pellucida, as cells in the caudal midline undergo an epithelial-to-mesenchymal transformation, and that extensive migration of delaminated cells arising from more rostral or peripheral areas of the blastoderm is not involved in streak formation. Instead, such delamination occurs earlier and is restricted to the process of hypoblast formation. Moreover, we provide evidence that progression of the primitive streak involves two processes: convergent-extension movements within the streak per se, and progressive delamination of midline epiblast cells in a caudal-to-rostral sequence. We have identified a subpopulation of primitive-streak cells located at its dorsal midline surface that undergoes extensive rostral displacement concomitant with streak progression. The fact that these cells are located only dorsally and do not elongate ventrally as do adjacent ingressing cells, suggests that these cells retain their residency within the primitive streak, at least until regression of the primitive streak occurs. Finally, by following labeled cells over time we establish the timing of movement of epiblast cells toward and into the primitive streak, providing direct evidence that cell-cell intercalation occurs within the primitive streak during its progression. Collectively, our results provide new insight into complex and central events of avian gastrulation. © 2001 Wiley-Liss, Inc.Item Cell populations and morphogenetic movements underlying formation of the avian primitive streak and organizer(Genesis, 2001-04) Lawson, A.; Schoenwolf, G.C.Summary: The cell populations and morphogenetic movements that contribute to the formation of the avian primitive streak and organizer - Hensen's node - are poorly understood. We labeled selected groups of cells with fluorescent dyes and then followed them over time during formation and progression of the primitive streak and formation of Hensen's node. We show that (1) the primitive streak arises from a localized population of epiblast cells spanning the caudal midline of Koller's sickle, with the mid-dorsal cells of the primitive streak arising from the midline of the epiblast overlying Koller's sickle and the deeper and more lateral primitive streak cells arising more laterally within the epiblast overlying the sickle, from an arch subtending about 30°; (2) convergent extension movements of cells in the epiblast overlying Koller's sickle contribute to formation of the initial primitive streak; and (3) Hensen's node is derived from a mixture of cells originating both from the epiblast just rostral to the incipient (stage 2) primitive streak and later from the epiblast just rostral to the elongating (stage 3a/b) primitive streak, as well as from the rostral tip of the progressing streak itself. Collectively, these results provide new information on the formation of the avian primitive streak and organizer, increasing our understanding of these important events of early development of amniotes. © 2001 Wiley-Liss, Inc.Item Ectodermal markers delineate the neural fold interface during avian neurulation(Anatomical Record, 2000-09) Lawson, A.; Colas, J.-F.; Schoenwolf, G.C.The formation and morphogenesis of the neural folds are important processes underlying neurulation. We showed previously that these processes comprise four key events in avian embryos: epithelial ridging, kinking, delamination, and apposition. Collectively, these events establish the paired, bilaminar neural folds, which fuse in the dorsal midline during late neurulation to close the neural groove and to establish the neural tube. Here, we use an antisense riboprobe for a new gene called Plato, as well as an antibody for a previously cloned transcription factor, AP-2, as markers to identify critical subpopulations of ectodermal cells during the formation and morphogenesis of the avian neural folds. Plato antisense riboprobe marks the cranial neural ectoderm and premigratory cranial neural crest cells, whereas AP-2 antibody marks the epidermal ectoderm and the early migratory neural crest. We show that subpopulations of ectodermal cells at the forebrain and midbrain levels undergo considerable rearrangement within the neural fold transition zone, which redistributes incipient neural crest cells from the neural ectodermal side of the forming neural fold interface to the epidermal ectodermal side. Additionally, we show that Plato and AP-2 provide useful markers for delineating the incipient neural fold interface. (C) 2000 Wiley-Liss, Inc.Item Creating a charter of collaboration for international university partnerships: The elmina declaration for human resources for health(Academic Medicine, 2014-06) Anderson, F.; Donkor, P.; De Vries, R.; Appiah-Denkyira, E.; Dakpallah, G.F.; Rominski, S.; Hassinger, J.; Lou, A.; Kwansah, J.; Moyer, C.; Rana, G.K.; Lawson, A.; Ayettey, S.The potential of international academic partnerships to build global capacity is critical in efforts to improve health in poorer countries. Academic collaborations, however, are challenged by distance, communication issues, cultural differences, and historical context. The Collaborative Health Alliance for Reshaping Training, Education, and Research project (funded by the Bill and Melinda Gates Foundation and implemented through academic medicine and public health and governmental institutions in Michigan and Ghana) took a prospective approach to address these issues. The project had four objectives: to create a "charter for collaboration" (CFC), to improve data-driven policy making, to enhance health care provider education, and to increase research capacity. The goal of the CFC was to establish principles to guide the course of the technical work. All participants participated at an initial conference in Elmina, Ghana. Nine months later, the CFC had been revised and adopted. A qualitative investigation of the CFC's effects identified three themes: the CFC's unique value, the influence of the process of creating the CFC on patterns of communication, and the creation of a context for research and collaboration. Creating the CFC established a context in which implementing technical interventions became an opportunity for dialogue and developing a mutually beneficial partnership. To increase the likelihood that research results would be translated into policy reforms, the CFC made explicit the opportunities, potential problems, and institutional barriers to be overcome. The process of creating a CFC and the resulting document define a new standard in academic and governmental partnerships.