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J Sall

Publications and source records attributed to J Sall.

7 recordsLinked to original sources
PubMed1999

Biochemical aspects of flight and flightlessness in Gryllus: flight fuels, enzyme activities and electrophoretic profiles of flight muscles from flight-capable and flightless morphs.

Female Gryllus assimilis subjected to 4.5-7.7h continuous tethered flight had significantly lower amounts of total lipid, triglyceride and total soluble carbohydrate compared with unflown controls. A much greater amount of total lipid (6.3mg) was used during flight compared with carbohydrate (0.14mg). Flown individuals also had substantially reduced amounts of injected, radiolabeled [(14)C]-oleic acid. Activities of lipid, carbohydrate and amino acid catabolizing enzymes in flight muscles of G. assimilis and its wing-polymorphic congener, G. firmus, were very similar to activities in insects which primarily utilize lipid to power flight. By contrast, enzyme activities were very different from those in insects which primarily or exclusively use carbohydrate or proline as a flight fuel. These results strongly implicate lipid as the major flight fuel in Gryllus. Previous studies have shown that lipid levels are higher in flight-capable (long-winged) G. firmus that have small ovaries compared with flightless (short-winged) females that have large ovaries. Results of the present and previous studies collectively indicate that elevated lipid in long-winged G. firmus represents an energetic cost of flight capability which reduces (trade-offs with) reproduction in Gryllus. In G. firmus, mass-specific activities of nearly all enzymes were considerably reduced in underdeveloped, and to a lesser degree in histolyzed muscle, compared with fully-developed flight muscle. An important exception was alanine aminotransferase, whose activity was the highest in histolyzed muscle, and which may be involved in the catabolism of amino acids derived from muscle degradation. Despite the dramatic differences in enzyme activity, electrophoretic profiles of soluble flight-muscle proteins differed only subtly between fully-developed and underdeveloped or histolyzed flight muscles.

Journal Article↗
PubMed1994

Histopathologic consequences of moderate concussion in an animal model: correlations with duration of unconsciousness.

Although duration of unconsciousness is commonly used as a prognostic index following traumatic brain injury (TBI), few controlled studies have statistically evaluated the relationship between unconsciousness and histologic pathology, particularly after moderate head injury. Using a pendulum-striker concussive device, a reproducible model of TBI in rats was developed. This model is uncomplicated by skull fractures, contusions, or experimenter-induced craniotomies. In the present study, the severity of the histopathology observed in this model of moderate closed-head injury at 48 h posttrauma is linearly related to the duration of unconsciousness (p < 0.0001). The pathology, assessed with a silver stain for neurodegeneration, is particularly striking if unconsciousness persists for 4 minutes or more. These data suggest that the initial period of unconsciousness may be a useful predictor of clinical brain histopathology associated with moderate closed-head injury, predicting either the degree of pathology and/or the rate it progresses if left untreated.

Animals↗
PubMedDate not supplied

Flight-muscle polymorphism in the cricket Gryllus firmus: muscle characteristics and their influence on the evolution of flightlessness.

Flight muscles of the cricket Gryllus firmus are polymorphic, existing as pink or white phenotypes. White muscles are smaller in size, have reduced number and size of muscle fibers, and have reduced in vitro enzyme activities and respiration rates relative to pink muscles of newly molted, fully winged adults. G. firmus is also polymorphic for wing length. All newly molted long-winged adults exhibited the pink-muscle phenotype, while most newly molted short-winged adults exhibited the white-muscle phenotype, which resulted from arrested muscle growth. As long-winged adults aged, fully grown pink muscle was transformed into white muscle via histolysis. The substantially higher respiration rate of pink muscle likely contributes to the elevated whole-organism respiration rate of long-winged females, which has been documented previously and which is thought to divert nutrients from egg production. Histolyzed white flight muscle from long-winged crickets also exhibited significantly elevated respiration rate and enzyme activities compared with underdeveloped white muscle from short-winged adults, although these differences were not as great as those between pink and white muscles. Fecundity was much more elevated in females with white verus pink flight muscles than it was in females with short versus long wings. The fitness gain resulting from flightlessness has typically been estimated in previous studies by comparing enhanced egg production of short-winged and long-winged females, without considering the influence of flight-muscle variation. Our results suggest that the magnitude of this fitness gain has been substantially underestimated.

Aging↗
PubMedDate not supplied

Cytologic effects of Thiotepa and Adriamycin on normal canine urothelium.

An experimental investigation was carried out to produce and observe controlled, sequential changes in normal bladder urothelium of female dogs caused by Thiotepa (triethylene thiophosphoramide) and Adriamycin (doxorubicin hydrochloride). Thiotepa (30 mg in 30 ml saline) was instilled for two hours into the bladders of five dogs at weekly intervals, and Adriamycin (1 ml/kg body weight) was given intravenously to five dogs at weekly intervals for a period of ten weeks. Control animals underwent only bladder irrigation with saline. Periodic catheterized urine and saline bladder irrigations and bladder biopsy specimens were obtained. After the tenth week all dogs were killed and autopsies conducted. Major observations in the experimental animals included cellular enlargement, bizarre cell shapes, cytoplasmic vacuolization, nuclear and nucleolar enlargement, multinucleation, pyknosis, karyorrhexis and infiltration by neutrophilic leukocytes. In some animals, reversion to a normal cytologic pattern occurred in the ten-week period. The application of these observations to human urinary cytopathology is discussed.

Animals↗