Biomedical subjects

D M Mulhern

Publications and source records attributed to D M Mulhern.

3 recordsLinked to original sources

PubMed2001

Differences in osteon banding between human and nonhuman bone.

The objective of this paper is to compare patterns of osteon organization in human and nonhuman bone. A linear organization of Haversian systems in nonhuman bone, where osteons line up in rows, has been reported but has not been quantified. The present research provides a quantitative examination of this observation through a comparative analysis of the femoral midshaft from human and nonhuman bone. Femoral midshaft thin sections from 60 humans were compared to femoral midshaft sections from nine sheep and six miniature swine. The presence or absence of osteon banding was recorded and, if present, described. Results indicate that 2 out of 60 human sections and 5 out of 15 nonhuman sections exhibit osteon banding (chi2 = 9.46; p < 0.01). Further, the type of banding present in the human and nonhuman samples is easily distinguished, indicating that human and nonhuman bone can be distinguished where handing is present in this study.

Adolescent↗

PubMed2000

Rib remodeling dynamics in a skeletal population from Kulubnarti, Nubia.

Bone remodeling variables in the rib were analyzed for a skeletal population of medieval antiquity (ca. A.D. 550-1450) from Kulubnarti, in Sudanese Nubia. The skeletal remains are naturally mummified and in an excellent state of preservation. The study sample consists of thin sections from the ribs of 80 individuals, ranging in age from 15-50+ years. Ribs were examined using a standard microscope and image analysis software. Numbers of intact osteons, fragmentary osteons, forming osteons, and resorption spaces were counted, osteon and Haversian canal areas were measured, and several variables were calculated to assess morphometric and remodeling status in the rib. Variables calculated included mean annual activation frequency, mean bone formation rate, and net osteonal remodeling. Results indicate that age changes are consistent with those observed for other archaeological and modern samples. High numbers of resorption spaces in young males may reflect slower skeletal development in boys compared to girls. Comparisons of rib data with results of a previous study on patterns of femoral bone remodeling in the same population indicate that ribs have more osteons and higher bone formation rates compared to the femur. Also, sexual differences in osteon size observed in the femur were not observed in the rib. Activation frequency and bone formation rate are low in the Kulubnarti population compared to previously published data for a modern sample, a finding consistent with reported results from other archaeological samples. Genetic factors influencing the minimum effective strain setpoint and duration of skeletal maturation, in addition to repetitive high strains at Kulubnarti, may contribute to observed differences.

Age Determination by Skeleton↗

PubMed1997

Patterns of femoral bone remodeling dynamics in a Medieval Nubian population.

The relationship between age, sex and histomorphometry in femoral cortical bone was examined in a skeletal population of late Medieval antiquity (AD 1250-1450) from Kulubnarti, in Sudanese Nubia. These skeletal remains are naturally mummified and in an excellent state of preservation. The study sample consisted of femoral cross sections from 24 females and 19 males ranging in age from 20 to 50+ years. Femoral cross sections were examined using an image analysis system. Numbers of secondary osteons and osteon fragments were counted, osteon area and Haversian canal area were measured, and several variables were calculated to assess differences between sexes and among age groups in bone remodeling variables. The results indicate significant differences between the sexes in osteon number and size. Males had significantly more intact osteons than females, whereas females had significantly larger osteons than males. Haversian canal dimensions were not statistically significant between the sexes. Sex differences in activity patterns in which males were involved in more physically strenuous tasks may have contributed to differences in remodeling variables. Interpopulational comparisons suggest that mechanical strain affects the microstructural features examined in this study. In particular, small Haversian canals in some archaeological skeletal populations are associated with higher bone volume, which may result from high levels of mechanical strain.

Adult↗