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Biomedical subjects

A Snyder

Publications and source records attributed to A Snyder.

8 recordsLinked to original sources
PubMed1992

The effects of exercise mode, swimming vs. running, upon bone growth in the rapidly growing female rat.

The purpose of this study was to compare the effects of two programs of endurance training, of equal duration and intensity, on bone development in female rats. Thirty-eight female Wistar rats were randomly assigned to one of three groups: run-trained (RUN), swim-trained (SWIM) or control (CON). The RUN group ran at a speed of 27 m/min up an 8 degrees incline. Swim trained animals swam with 2% of body weight attached to their tails. Training sessions were 2 h/day, 5 days/week and were conducted over a 10-week period. Hindlimb and forelimb muscles were removed upon sacrifice and analyzed for citrate synthase (CS) activity, liver (LG) and muscle (MG) glycogen. The parametrial fat pads were removed, digested with collagenase, and 2-deoxy-D-[3H]glucose uptake measured in isolated cells. Bone weight, length, diameter, ponderal index and bone mineral content (BMC) were measured in the femur and humerus of each animal. The LG, MG, fat cell volume, glucose uptake of the adipocyte and adrenal weight data indicate that the training response was identical. The CS activity of the muscles indicated that mechanical and recruitment patterns of the upper and lower body differ and could be responsible for bone development patterns found in this study. Exercise had a minimal effect on bone growth in the run-trained animals but did stimulate development in the swim-trained animals. The humerus of the SWIM was significantly (P < 0.05) heavier, wider and had a greater BMC when compared with those of the RUN and CON rats. The results of this study indicate that the muscular forces applied by the swim training protocol produced greater bone adaptations than the forces applied by a running protocol of equal duration and intensity.

Animals↗
PubMed1991

Antioxidant enzymes in human tears.

Minimally stimulated tear samples collected from human subjects were assayed for the major antioxidant enzymes: superoxide dismutase, catalase and glutathione peroxidase. No catalase or glutathione peroxidase activity was detected. However, human tear film does contain the CuZn superoxide dismutase (103 +/- 32 ng/mg soluble protein), which is inactivated by hydrogen peroxide (0.2 mM). These data indicate that the tear film has the enzyme generally required for control of inflammatory conditions but is lacking the usual physiological defense systems against the toxicity of hydrogen peroxide. Concern has been raised as to the safety of contact lens disinfectant solutions containing hydrogen peroxide. These results indicate that the tear film is lacking the enzyme systems to provide significant protection to the cornea, to the tear film itself, or to the SOD of the tear film from the oxidant action of hydrogen peroxide.

Adult↗
PubMed1989

Unmet needs and barriers to service delivery for the blind and visually impaired elderly.

Reported is a state-wide survey of aging and blindness agencies. Shown by the findings was that a large percentage of aging agencies are not addressing the needs of the aging blind population. In addition, the lack of interaction between the two systems is a major service delivery barrier. Suggested by the data was the need for improvement in understanding the needs, resources, and areas of expertise of each system, with additional training and better communications between the systems being especially important.

Aged↗
PubMed1979

Deficits in the visual evoked potentials of cats as a result of visual deprivation.

Visual evoked potentials in response to contrast reversal of grating patterns were used as a measure of visual function in normal and visually deprived cats. In cats which had been dark reared from birth (BD cats) there was a characteristic change in VEP waveform from normal, for both eyes and for all spatial frequencies of testing stimulus. In cats which had one eye sutured from the age of one week (MD cats), the VEP from the deprived eye was smaller for contrast reversal of coarse patterns. Kittens given only restricted periods of monocular exposure gave VEPs which resembled the pathological responses of the BD cats. However, the amplitudes of response were larger for the more experienced eye at higher spatial frequency. This work reinforces the idea that two factors govern cortical development: competition and experience. Lack of sufficient visual experience leads to severe intracortical pathology.

Aging↗
PubMed1975

Secondary orgasmic dysfunction. II. Case study.

The treatment of a case of secondary orgasmic dysfunction is described. In this case, a direct behavioral retraining program was employed to increase the couple's repertoire of effective sexual behaviors. An extinction and successive approximation procedure was used to transfer ortasmic responsiveness from solitary masturbation to heterosexual coitus. Since other data have indicated that nonsexual marriage problems contribute to the maintenance of secondary orgasmic dysfunction, a direct, confrontive intervention into the marital relationship was made concurrent with the sexual retraining program. Outcome data are presented to illustrate the effectiveness of the reatment procedures.

Adult↗
PubMedDate not supplied

CT findings after uncomplicated percutaneous laparoscopic cholecystectomy.

To investigate the postoperative pulmonary and abdominal findings following uncomplicated percutaneous laparoscopic cholecystectomy, 27 patients were studied by upper abdominal CT within 24 h of the surgical procedure. Both pneumoperitoneum (70%) and subcutaneous emphysema (56%) were commonly observed. Postoperative atelectasis and pleural effusions were observed in 44 and 33% of the patients, respectively. Forty-eight percent of the patients had a postoperative ileus demonstrated by CT. Approximately 22% of the patients had fluid in the abdomen as either edema in the gallbladder fossa or small amounts of ascites. In our patients the amount of ascitic fluid was small and no clinical significance could be attributed to the intraabdominal fluid collections.

Adult↗
PubMedDate not supplied

A completely implantable total artificial heart system.

The authors developed, built, and tested in vivo a completely implanted total artificial heart (TAH) system. The system used a reduced size version of a roller screw energy converter and mating sac blood pumps. The motor drive, pumps, and a compliance chamber were implanted intrathoracically. A canister containing controlling electronics and an emergency battery was implanted in the abdomen. The secondary coil of an inductive energy transmission and telemetry system was placed over the ribs. The system was implanted in three calves, that survived 0.5-13 days with the system. The system maintained safe left atrial pressures and adequate cardiac outputs during each animal's entire course.

Animals↗