Biomedical subjects

R Shenker

Publications and source records attributed to R Shenker.

4 recordsLinked to original sources

PubMed1996

The effect of fibrin sealant on spinal fusions using allograft in dogs.

STUDY DESIGN: This study investigated the use of Tisseel (immuno [Canada], Toronto, Ontario) as an adjunct to allograft spinal fusion. Thirteen mongrel, dogs were fused bilaterally with morcellized graft from a separate dog. OBJECTIVES: To evaluate whether fibrin sealant had an effect on bone volume of fusion mass in allograft fusions of the spine. SUMMARY OF BACKGROUND DATA: Fibrin sealant has been promoted for use in many orthopedic applications. There is controversy about its effectiveness in augmenting bone graft healing. However, some surgeons make routine use of the sealant in augmentation of bone grafting procedures. METHODS: To test the usefulness of this material in augmenting allograft fusions, the authors carried out bilateral posterolateral fusions in 13 mongrel dogs. At surgery, 15 cm3 of allograft was placed into a posterolateral position at the L5-L6 region on both sides of the spine. Fibrin sealant (Tisseel) was allocated randomly to one side only. Fusion mass was tested 6 months after the initial operation by computed tomographic scan imaging and mechanical testing. RESULTS: A significantly smaller bone volume mass, as illustrated by computed tomographic measurement, was seen on the Tisseel side (P = 0.03). Biomechanical testing indicated that there was a trend for the Tisseel side to be stiffer than the untreated side, particularly at lower weights, but statistical significance was not achieved. Computed tomographic volumetric analysis showed that Tisseel-treated allograft led to a significantly smaller fusion volume. CONCLUSIONS: This study refutes the belief that Tisseel is a good material for accomplishing or augmenting intervertebral arthrodesis. Fibrin sealant significantly retards allograft fusion mass formation in dogs.

Animals↗

PubMed1996

Purim syncope.

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Adolescent↗

PubMed1988

Hyperactive boys almost grown up. II. Status of subjects without a mental disorder.

In a previous article we reported the rate of DSM-III diagnoses among 101 male adolescents (aged 16 to 23 years) in whom hyperactivity had been diagnosed between ages 6 and 12 years compared with 100 controls. This report examines the rates of dysfunction among the 52 probands and 80 control adolescents who did not receive a DSM-III diagnosis at follow-up. Contrary to expectations, there were few areas (primarily involving school adjustment) in which the formerly hyperactive children were found to be at a disadvantage and numerous areas (occupational adjustment, temperament, alcohol abuse, antisocial activities, etc) in which the groups were indistinguishable. The results are explained in accordance with a bimodal distribution of dysfunction in hyperactive children grown up. Indirectly, this model supports the construct validity of the DSM-III diagnoses attention deficit disorder with hyperactivity, substance use disorder, and antisocial personality disorder. Post hoc analyses suggest that behavior problems resulting from drug use in early adolescence have graver consequences for previously hyperactive children than normal subjects.

Achievement↗

PubMed1985

Hyperactive boys almost grown up. I. Psychiatric status.

We report a prospective longitudinal study of 101 male adolescents (ages 16 to 23 years) who had been diagnosed hyperactive in childhood (ages 6 to 12 years), compared with 100 normal controls. The DSM-III diagnoses were made blind to group membership. Information was obtained for 98% of the original cohort. The full attention deficit disorder with hyperactivity (ADDH) syndrome persisted in 31% of the probands vs in 3% of the controls. The only other two conditions that distinguished the groups significantly were conduct and substance use disorders. These disorders aggregated significantly among the probands with continued ADDH. The results indicate that the greatest risk factor for the development of antisocial behavior and drug abuse is the maintenance of ADDH symptoms. Substance use disorders followed the onset of conduct disorder in the overwhelming majority of the cases.

Adolescent↗