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Biomedical subjects

S Katzman

Publications and source records attributed to S Katzman.

12 recordsLinked to original sources
PubMed2001

Juvenile coho salmon locomotion and mosaic muscle are modified by 3',3',5'-tri-iodo-L-thyronine (T3).

Studies of maximum aerobic swimming performance in smolting juvenile salmonids indicate that these animals may be aerobically compromised during downstream migration. To test our hypothesis that hyperthyroid status contributes to decreased swimming performance through modification of muscle contractility in juvenile (112 mm mean total length) coho salmon (Oncorhynchus kisutch), we measured swimming performance and isolated muscle bundle contractility of fish implanted with 3',3',5'-tri-iodo-l-thyronine (T3) pellets, of fish implanted with sham pellets and of fish with no pellet implantation (control group). After 3 weeks (N=12-13), critical swimming speeds (maximum aerobic swimming speed or U(crit)) were measured. Muscle bundles (N=15-16) were dissected from the hypaxial musculature and stimulated to measure the force and velocity of an isometric twitch and tetani. T3-treated fish demonstrated visible morphological changes associated with smoltification. Mean values of U(crit) were significantly decreased and the prolonged contraction (tetani) and twitch rates of contraction, relaxation and maximum force were significantly increased by T3 treatment compared with both the sham and control fish. Hematocrit, body mass and body length were not significantly affected by T3 treatment. In conclusion, we suggest that the reported decrease in U(crit) during salmonid smoltification may be mediated by endogenous T3-induced contractile modification of mosaic muscle fibers.

Analysis of Variance↗
PubMed2000

Screening for STDs.

Explore the source record for details and available documents.

Gene Amplification↗
PubMed1996

The causes of failure of lumbar transpedicular spinal instrumentation and fusion: a prospective study.

A prospective study was made of 101 patients who underwent transpedicular spinal instrumentation and fusion of the lumbar spine. All were reviewed by an independent observer. The objectives were to determine the causes of clinical failure and to recommend preventive measures. Forty-two primary and 59 revision operations were performed. The average age was 46 years and follow up 4 years. The variable screw placement and Cotrel-Dubousset systems were used. Posterior lumbar interbody fusion was carried out in 24 patients. The outcome was satisfactory after primary operations in 67% and after revisions in 46%. Nerve root injuries due to screw placement occurred in 4% (2% permanent and 2% transient). Instrumentation-induced foraminal stenosis developed in 2%. Proper surgical technique can avoid these complications. Predictive factors for failure are: abnormal psychology, symptomatic epidural fibrosis, inadequate decompression of lateral stenosis, surgical complications and the use of allografts.

Adolescent↗
PubMed1995

The importance of the blood supply in the healing of tibial fractures.

A clinical study of the effects of nonischemic arterial injuries to the leg on tibial fracture healing is presented. In addition, the literature published during the past 100 years describing the vascular supply to the tibia is reviewed, and the San Francisco General Hospital treatment protocol for difficult open tibial fractures is outlined. Based on the finding that the delayed and nonunion rate is three times higher when one of the three arteries of the leg is disrupted, a modification of the Gustilo fracture classification is proposed.

Arteries↗
PubMed1994

Delayed unions and nonunions of open tibial fractures. Correlation with arteriography results.

To investigate the importance of arterial integrity in tibial fracture healing, the authors retrospectively assessed prognosis as a function of arterial injury in a large series of tibial fracture patients. The records of 114 patients who were treated for an open fracture of the tibia at a San Francisco hospital between 1981 and 1991 were selected for review; in each case, the injury had been caused by a blunt trauma, and arteriography had been performed to evaluate a suspected arterial injury in the ipsilateral extremity. Sixty-two patients had had a normal arteriogram and 52 had demonstrated occlusion of one or two of the three arteries that supply the foot. The group of patients who had demonstrated arterial occlusion had a significantly greater incidence of delayed union or nonunion (24 of 52 compared with ten of 62) and notably more cases of osteomyelitis (nine of 52 compared with four of 62); when the patients with osteomyelitis are excluded, the difference between the groups is still significant. This study is the first that indicates that patients with open fractures of the tibia who demonstrate arterial occlusion in their ipsilateral extremity may be more prone to delayed union or nonunion. More vigilant follow-up evaluation may therefore be warranted in such patients to better anticipate the need for exchange rodding or bone grafting.

Adolescent↗