Marilyn L. Zimny

Effects of Hibernation on Interradicular Alveolar Bone

The interradicular alveolar bones of the nonhibernating and hibernating ground squirrels were compared using laght and transmission electron microscopy. During hibernation changes occurring in the bone suggest osteocytic osteolysis. Minerals may be mobilized from bone for utilization elsewhere in the body to maintain a minimal metabolic level for surtival.

Experimental temporomandibular joint disc perforation in the rabbit: A gross morphologic, biochemical, and ultrastructural analysis*****

This study evaluates the progression of osteoarthritis (OA) in the adult New Zealand white rabbit temporomandibular joint following unilateral disc perforation. Thirty-seven animals were divided into five groups: control (n = 8), 6-week sham (n = 5), and experimental 6-, 12-, and 24-weeks (n = 8 each). Quantitative data was examined with two-way analysis of variance, and followed by Scheffe pair-wise comparisons. Transmission electron microscopy, acid phosphatase [AcP] activity, uronic acid content, and gross morphologic analysis indicated that disc perforation induced remodeling activity and degenerative changes in the condylar cartilage and bone as early as 6 weeks postoperatively. AcP activity of homogenized cartilage samples was significantly increased in experimental joints versus the side that did not undergo surgery at 6 and 12 weeks (P < .05). Uronic acid content was significantly greater in experimental joints versus the side that did not undergo surgery at 6 weeks (P < .05). Heightened cellular activity was present in the deep zone of osteoarthritic fibrocartilage of the 6- and 12-week experimental groups. Degenerating chondrocytes appeared to contain greater proportions of intracytoplasmic filaments and lysosome-like bodies. Disc perforation provided the impetus for degenerative or remodeling changes in the condylar cartilage of experimental joints, and is consistent with secondary OA. These dynamic events were most significant in the deep zone of articular fibrocartilage.

High-Energy Phosphates during Long-Term Hibernation

Adenosine triphosphate (ATP) and phosphocreatine (PC) show contrasting levels in muscle and liver after short and long periods of hibernation. In prolonged hibernation cardiac and skeletal muscle PC continues to maintain ATP, but at lower levels. In the liver, control levels for these compounds are regained.

Mechano-Receptors in the Flexor Tendons of the Hand

Flexor tendons of the hand obtained fresh at autopsy were studied histologically for free nerves and mechano-receptors. In addition to free nerves, Ruffini endings, Pacinian corpuscles and Golgi tendon organs were found throughout the tendons. Golgi tendon organs and Pacinian corpuscles were subjectively in greater numbers than Ruffini endings. The predominance of these two mechano-receptors indicates that position sense and kinetic activities of the fingers are well-served, as evidenced in hand movements.

Ultrastructure of the proximal convoluted tubule of a hibernator correlated with renal enzymology

Abstract 1. 1. The proximal convoluted tubule cell of a hibernating ground squirrel shows vacuolization, increase in width of basal plasmalemma compartments and intramitochondrial granules. 2. 2. The cell of an awakening animal contains pycnotic nuclei and no distinct basal compartments. 3. 3. During hibernation renal SDH, ATPase and Achase increase in activity and during awakening SDH decreases. 4. 4. During awakening urinary sodium, potassium and glucose decrease.

Anatomical demonstration of the nerve-supply to the flexor tendon

A dissection of four unembalmed human fingers demonstrated a branch from the digital nerve which enters the flexor tendon sheath at the same place as the transverse branch of the digital artery. We conclude that this branch supplies the nerve fibres found within the vinculum.

ATPase and succinate dehydrogenase in hearts of hypothermic ground squirrels and rats

Abstract The reaction rates of Mg-ATPase and succinate dehydrogenase (SDH) in particulate suspensions of myocardium from three groups of ground squirrels 38 °C, 15 °C and 5 °C; and two groups of rats, 38 °C and 15 °C were determined at incubation temperatures of 38 °, 15 ° and 5 °C. The ATPase reaction rate decreased with decreasing incubation temperature in both control groups. In hypothermic rats (15 °C) the ATPase reaction rate also decreased with decreasing incubation temperature while in hypothermic ground squirrels (15 °C and 5 °C) no significant changes were seen. The SDH reaction rate decreased significantly with decreasing temperature in samples from both control and hypothermic rats. The SDH reaction rate in all groups of ground squirrels was lower at 15 °C than at 5 °C incubation. At low body temperatures in the ground squirrel maintenance of (1) ATPase activity regulates oxidative phosphorylation and (2) SDH minimizes or prevents anoxia by facilitating utilization of oxygen or increasing rate of carbon dioxide release.

Ultrastructure of solitary enchondromas.

Solitary enchondromas obtained from the small bones of the hand were studied with transmission electron microscopy. Three cell types were seen as follows: (1) young looking, active cells with extensive dilated rough endoplasmic reticulum and well defined Golgi and mitochondria; (2) older looking, degenerating cells with dilated rough endoplasmic reticulum, well defined Golgi, glycogen masses, vacuoles containing tropocollagen, lipid and myelin figures; and (3) dying cells showing loss of cell membrane and lysosomal-like bodies. A young chondroblastic cell may try to mature, become a normal chondrocyte that produces normal matrix but it does not succeed and dies. Enchondromal cells are not capable of forming tropocollagen or synthesizing proteoglycans for the matrix.

Effects of hibernation on dental tissues: A sem analytical study

Abstract 1. 1. The mean acellular cementai width in the hibernating ground squirrel is 25.6 μm mesial while that of the non-hibernating animal is 68 μm. 2. 2. Analyses using X-ray spectrometry with a scanning electron-microscope showed that, in the hibernating animal, Ca and P increased and S decreased in the cementum; Ca, P and S increased in the periodontal ligament; and Ca and P increased in both the dentin and alveolar bone. 3. 3. We believe that these changes represent the mobilization of mineral elements for metabolic use by vital tissues and accompanying ground substance changes.