Acetate-1-14C incorporation into polyunsaturated fatty acids of phospholipids of developing chick brain

The incorporation of acetate-1-(14)C into the polyunsaturated fatty acids of glycerophosphatides of chick embryonic brain has been studied. After the injection of acetate-1-(14)C into the yolk sac, differences were found in the degree of labeling of the major fatty acids of the omega3 and omega6 series. Arachidonic acid (20:4omega6) showed a high degree of radioactivity while docosahexaenoic acid (22:6omega3) was poorly labeled, at a period of brain development when both fatty acids were being actively deposited. Evidence is presented to indicate that the low activity in docosahexaenoic acid is not explicable on the basis of either a low or high rate of turnover of this polyenoic acid. Similar results were obtained whether the rapid early or slower late stage of brain development was examined. It is suggested that the elongation of omega3 and omega6 series acids may be under the control of different regulatory mechanisms.

Comparative studies between pathogenesis of street and fixed rabies infection

Comparative neuropathology of Ammon's horn caused by both the street and fixed rabies infection was studied by combined light and electron microscopy. Neurons containing Negri bodies appeared comparatively little damaged. In striking contrast, in the case of fixed virus infection, neurons showed the following variety of degeneration. Lightly damaged neurons showed an increase in the number of small vesicles throughout the cytoplasm. A considerable number of lysosomes were also encountered within these nerve cells. Severe necrotic alteration involving the nucleus as well as the cytoplasm was found in the nerve cell band. The characteristic homogeneous foci (matrices) were discernible within these neurons. It appears that the matrix is morphologically identical with the ground substance of the Negri body, though its size is smaller than that of the Negri body. This evidence suggests a possibility that fixed virus injures neurons so extensively that they cannot bring about the full development of the characteristic matrix of the Negri body recognizable by the light microscope. Selective vulnerability was demonstrated among different groups of neurons in respect of cytopathogenesis of both street and fixed virus infection.

Fatty acids of glycerophosphatides in developing chick embryonic brain and liver

Fatty acid compositions of glycerophosphatides of developing chick embryonic brain and liver were compared. In brain, ethanolamine and serine glycerophosphatides contained 30-40% polyunsaturated fatty acids, lecithin almost none (except for arachidonic). In the liver, these acids were equally distributed in the phospholipid fractions. The principal polyunsaturated fatty acids of the ethanolamine and serine glycerophosphatides in brain, liver, and yolk were 22:6, 20:4, and 18:2, respectively. During embryonic development of brain from the 8th day of incubation to hatching, the fatty acid composition of individual glycerophosphatide fractions remained constant. Because of the relative increase of ethanolamine glycerophosphatides and decrease of lecithin, total glycerophosphatides showed a decrease in 16:0 and an increase in 18:0. Substantial amounts of palmitaldehyde and stearaldehyde were present on the 8th day of incubation in the brain ethanolamine glycerophosphatide fraction. During the 3rd week of incubation, the liver showed a two-fold increase in the relative amount of 18:2 in all glycerophosphatide fractions. A decrease of 16:0 in the lecithin fraction and consequently in total glycerophosphatides was also observed during this period. No significant changes in glycerophosphatide fatty acids were observed in the yolk throughout incubation.

Changes in masseter muscle activity during orthodontic treatment evaluated by a 24-hour EMG system

This study was conducted to investigate changes in masseter muscle activity during orthodontic treatment. Data was collected using a 24-hour electromyogram (EMG) system. Bursts of masseter muscle activity were counted over 24-hour periods approximately weekly before, during, and after an 18-month period of active orthodontic treatment. The patient, a 25-year-old male, was treated with a multibracket appliance. The number of bursts decreased substantially during the initial leveling period when the archwires were adjusted and then recovered to near the original preactivation level. No remarkable changes in masseter muscle activity were recorded during the latter half of treatment, although masseter muscle activity fell again when the appliance was removed. Six months after the end of treatment, relatively stable masseter muscle activity-similar to that recorded before treatment-was maintained. These changes in masseter muscle activity during orthodontic treatment were probably due to discomfort or pain or to changes in the occlusal relationship between the maxillary and mandibular dentitions produced by tooth movement or by the orthodontic appliance itself.

Subjective complaints in orthopedists and general surgeons

The aim of this study was to investigate the prevalence of subjective complaints among two groups of health care personnel. Using a mail questionnaire, 63 male orthopedists and 78 male general surgeons were asked to respond to questions on their subjective musculoskeletal complaints as well as their age, occupational career, and daily working time. In the final analysis, 54 orthopedists and 63 general surgeons who were aged < or = 59 years and had worked for at least 5 years in clinical practice were considered. The mean age was 43.3 (SD 7.6) years for the orthopedists and 41.8 (SD 9.5) years for the general surgeons. Their mean employment time was 18.1 (SD 8.9) years and 16.6 (SD 9.5) years, respectively. The average working time per day was 9.5 h. In general, the orthopedists had a higher prevalence of subjective complaints than the general surgeons. Problems in the shoulders and lower back were the most frequently reported complaints, followed by neck problems. There were significant differences (P < 0.05) between the two groups regarding stiffness in the shoulders, stiffness in the lower back, pain in the neck, and numbness in the fingers. When subjective complaints were compared between the junior (employment time: < 20 years) and senior (employment time: > or = 20 years) staff, the junior orthopedists had significantly higher prevalence rates for stiffness in the shoulders, pain in the neck, and stiffness in the lower back.(ABSTRACT TRUNCATED AT 250 WORDS)