The role of autophagy in morphogenesis and stem cell maintenance.

During embryonic development, cells need to undergo a number of morphological changes that are decisive for the shaping of the embryo's body, initiating organogenesis and differentiation into functional tissues. These remodeling processes are accompanied by profound changes in the cell membrane, the cytoskeleton, organelles, and extracellular matrix composition. While considerably detailed insight into the role of autophagy in stem cells biology has been gained in the recent years, information regarding the participation of autophagy in morphogenetic processes is only sparse. This review, therefore, focuses on the role of autophagy in cell morphogenesis through its regulatory activity in TGFß signaling, expression of adhesion molecules and cell cycle modification. It also discusses the role of autophagy in stem cell maintenance which is very fundamental for cell renewal and replacement during development, pathogenesis of certain diseases and development of therapies. We are thus addressing here perspectives for further potentially rewarding research topics.

Atonal homolog 8/Math6 regulates differentiation and maintenance of skeletal muscle.

Atonal Homolog 8 (Atoh8) belongs to a large superfamily of transcriptional regulators called basic helix-loop-helix (bHLH) transcription factors. Atoh8 (murine homolog "Math6") has been shown to be involved in organogenesis during murine embryonic development. We have previously identified the expression of Atoh8 during skeletal myogenesis in chicken where we described its involvement in hypaxial myotome formation suggesting a regulatory role of Atoh8 in skeletal muscle development. Within the current study, we analyzed the effect of the loss of function of Atoh8 in murine primary myoblasts and during differentiation of pluripotent stem cells into myotubes, and the effect of its gain of function in C2C12 cells. Based on the observed results, we conclude that Atoh8 regulates myoblast proliferation via modulating myostatin signaling. Further, our data revealed a reduced muscle mass, strength and fiber size with significant changes to the muscle fiber type suggesting atrophy in skeletal muscle of Atoh8 mutants. We further report that Atoh8 knockout mice suffer from a condition similar to ambient hypoxia which may be the primary cause of the phenotype. Altogether, this study shows the significance of Atoh8 not only in myogenesis but also in the maintenance of skeletal muscle.

Reconstruction of femoral length from fragmentary femora.

The reconstruction of femoral length (FL) from fragmentary femora is an essential step in estimating stature from fragmentary skeletal remains in forensic investigations. While regression formulae for doing this have been suggested for several populations, such formulae have not been established for Ghanaian skeletal remains. This study, therefore, seeks to derive regression formulae for reconstruction of FL from fragmentary femora of skeletal samples obtained from Ghana. Six measurements (vertical head diameter, transverse head diameter, bicondylar breadth, epicondylar breadth, sub-trochanteric anterior-posterior diameter, and sub-trochanteric transverse diameter) were acquired from different anatomical portions of the femur and the relationship between each acquired measurement and FL was analyzed using linear regression. The results indicated significantly moderate-to-high correlations (r=0.580-0.818) between FL and each acquired measurement. The error estimates of the regression formulae were relatively low (i.e., standard error of estimate, 13.66-19.28 mm), suggesting that the discrepancies between actual and estimated stature were relatively low. Compared with other measurements, sub-trochanteric transverse diameter was the best estimate of FL. In the absence of a complete femur, the regression formulae based on the assessed measurements may be used to infer FL, from which stature can be estimated in forensic investigations.

Musculoskeletal disorders among first-year Ghanaian students in a nursing college.

OBJECTIVE: To estimate the prevalence and extent of MSDs among a sample of freshmen in a nursing college in Ghana. METHODS: A semi-structured self-reported questionnaire including the Nordic Musculoskeletal Questionnaire (NMQ) was used to collect information on age, gender and musculoskeletal complaints among a random sample of 200 students at a nursing and midwifery college in the Eastern region of Ghana. RESULTS: Out of the 200 questionnaires administered, 160 were retrieved of which 3 were found to be incomplete and void, yielding a total of 157 evaluable questionnaires, a response rate of 78.5%. One hundred and ten (70.1%) students reported having MSDs in the previous 12 months, of which a total 88 (56.1%) suffered disabling effects, while 70(44.6%) students reported having MSDs in the past 7 days. The prevalence of MSDs in the different body regions was generally low with clustered distribution in the neck, upper back, wrists/hands and lower back. CONCLUSION: Nursing students are at reasonably high risk of MSDs. Strategies to prevent this important public health problem amongst future generation of nursing students must be given utmost priority. This study provides the baseline data for more elaborative studies in the Ghanaian population.

Determination of Sex from Footprint Dimensions in a Ghanaian Population.

The present study sought to verify the utility and reliability of footprint dimensions in sex determination in a Ghanaian population. Bilateral footprints were obtained from 126 Ghanaian students (66 males and 60 females) aged 18-30 years at Koforidua Polytechnic using an ink pad and white papers. Seven dimensions-length of each toe (designated T1-T5) from the most anterior point of the toe to the mid-rear heel point, breadth at ball (BAB) and breadth at heel (BAH)--and the heel-ball (HB) index were obtained from each footprint. Some footprint dimensions (i.e. T2, T3, T4 and T5) showed statistically significant bilateral asymmetry in males only. All the footprint dimensions, except HB index, were significantly greater in males than females (p<0.001). Applied singly in discriminant function analysis, the footprint dimensions allowed 69.8%-80.3% of cases to be correctly classified into their sex groups; the accuracy of sex classification was higher using left footprints than right footprints. With all dimensions subjected to stepwise discriminant function analysis 80.3% and 77% of cases could be correctly classified, combining both T5 and BAH for left footprints and T1, BAB and BAH for left footprints respectively. The present study has demonstrated, for the first time among Ghanaian subjects, the utility and reliability of sex determination standards developed from footprint dimensions. The results thus provide the baseline for elaborated studies in the future.