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Biomedical subjects

M G Glover

Publications and source records attributed to M G Glover.

8 recordsLinked to original sources

Genetic architecture of fast- and slow-twitch skeletal muscle weight in 200-day-old mice of the C57BL/6J and DBA/2J lineage.

The aim of the study was to explore the genetic architecture influencing weight of fast- and slow-twitch skeletal muscles. The weights of the slow-twitch soleus, the mixed gastrocnemius, the fast-twitch tibialis anterior (TA), and extensor digitorum longus (EDL) muscles were 11-34% greater (P < 0.001) in 200-day-old C57BL/6J (B6) than in DBA/2J (D2) mice. Male muscles were 13-28% larger than female (P < 1 x 10(-5), no strain by sex interaction). The sex-related difference in muscle weight, however, varied significantly among the 23 derivative BXD recombinant inbred (RI) strains (strain by sex interaction for soleus, P < 0.01; TA, P < 1 x 10(-4); EDL, not significant; and gastrocnemius, P < 0.001). Quantitative trait loci (QTL) affecting muscle weight were mapped in an F2 intercross of B6 and D2 mice (B6D2F2) and BXD RIs. A total of 10 autosomal, muscle-specific, but not muscle-type-specific, QTL, explaining a total of 5.4, 7.7, 22.9, and 8.6% of phenotypic variance for soleus, TA, EDL, and gastrocnemius muscles, respectively, were found across chromosomes 1 (Chr 1), 2, 3 (female-specific), 5 (two), 6, 7, 8, and 9 in B6D2F2 mice. The QTL on Chr 8 for EDL and the female-specific QTL on Chr 3 for gastrocnemius muscles were statistically significant, but the remaining QTL were at the suggestive level of statistical significance. Ten QTL on Chr 1, 2, 4, 5, 7, 8, 14, 17 (two), and 19 were identified in BXD RIs. Half of the QTL in BXD RIs had pleiotropic effects and were at the suggestive level of significance (except for the significant QTL for gastrocnemius muscle on Chr 17). The B6D2F2 nominated QTL on Chr 8 for EDL weight was validated in BXD RIs (P < 0.03). Support intervals for the QTL on Chr 1 and 5 overlapped between B6D2F2 and BXD RIs. An epistatic interaction between markers on Chr 1 and 17 affected gastrocnemius weight in BXD RIs. The interaction was not, however, validated in the B6D2F2 population. Our results indicate that the differences in muscle weight in the B6 and D2 segregating populations were the outcome of a polygenic system, with each factor contributing a small amount to the phenotypic variance and the genetic architecture affecting muscle weight was muscle specific, but not muscle-type specific, and in some instances sex specific.

Aging↗

A new technique for the in vitro measurement of nucleus pulposus swelling pressure.

Swelling of the intervertebral disc nucleus pulposus may be a contributing factor in lower back pain syndromes. We have designed and tested a new osmometer for in vitro determination of nucleus pulposus swelling pressure. The functional principle of the osmometer involves compressing a sample of nucleus pulposus with nitrogen gas until saline pressure gradients across a 0.45-micron Millipore filter are eliminated. Swelling pressures of both pooled dog and pooled pig lumbar disc nucleus pulposus were measured on the new osmometer and were compared with swelling pressure determined using the equilibrium dialysis technique. The osmometer measured swelling pressures comparable to those obtained by the dialysis technique. This osmometer provides a rapid, direct, and accurate measurement of swelling pressure of the nucleus pulposus.

Animals↗

Plantar warts.

Plantar warts are an extremely common problem which can be very painful and debilitating. As is often the case with common problems, the knowledge of the disease and its treatments is inversely proportional to the frequency of the disease. Often the lay person knows as much and has as strong an opinion on treatment as the treating physician. In addition, most communities have someone who has the reputation of being able to bewitch warts off. This review will attempt to make some order of myriad facts and suppositions regarding this infection. Hopefully, this will aid the physician in the diagnosis and treatment of the patient with plantar warts.

Foot Diseases↗

Periodontitis in sheep: a model for human periodontal disease.

The use of sheep as a suitable animal model of destructive forms of human periodontal disease has been assessed from comparative radiological, histological, and serological investigations of sheep with and without periodontal disease. The results showed that, in sheep with periodontitis, bone resorption, collagen breakdown, degradation of blood capillary vessel walls, cellular infiltration of plasma cells, lymphocytes, and epithelial infiltration were significantly greater than in sheep without periodontitis, and the features are similar to those in rapidly destructive forms of periodontal disease in man. The levels of serum IgG antibody reactive against B. gingivalis antigens (measured by ELISA) were significantly higher in sheep with periodontitis than those without, similar to the association reported in some types of human periodontal diseases. These findings suggest that periodontitis in sheep could represent a suitable animal experimental model for certain types of rapidly destructive human periodontal diseases.

Alveolar Process↗

Intimal tears and their relationship to long-term patency in the rat femoral artery.

The prognostic importance of arterial intimal tears is not certain in the long term. We have developed a model to evaluate pure intimal damage in the absence of other soft tissue injury or arterial anastomoses to study the effect of isolated traumatic arterial intimal tears. Groups of ten rats each were examined at 1, 2, 4, 8, and 48 weeks and were shown to have no incidence of thrombosis of the femoral artery following traumatic intimal tears. Histologically, there was persistence of medial disorganization and smooth muscle hypertrophy up to 48 weeks. We feel that intimal lesions alone do not predispose a rat femoral artery to thrombosis but might do so in the presence of significant soft tissue injury or an arterial anastomosis.

Animals↗

Arterial intimal damage in avulsion and crush injuries in rat limbs.

A stereotypical pattern of arterial intimal damage has been demonstrated in rat avulsed and crushed injuries. These intimal tears can be found up to 6 cm proximal to the site of injury in avulsion injuries and are found at a delayed time with crush injuries. In both types of injury, circumferential intimal and subintimal tears spaced approximately 1 mm apart were demonstrated. These findings suggest a structural arrangement of the muscular artery wall that predisposes it to a reproducible pattern of damage. Veins undergoing the same avulsion and crushing procedure did not manifest any change. The presence of musculature rings or a weakened medial layer in artery walls after avulsion and crush injuries may influence short term patency and also long-term clinical replantation results.

Amputation, Traumatic↗