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Biomedical subjects

K S Schwartz

Publications and source records attributed to K S Schwartz.

At least 19 recordsLinked to original sources
PubMed1991

Clinical correlates of response to botulinum toxin injections.

We studied 242 patients with cervical dystonia who had adequate follow-up after botulinum toxin injections to determine which clinical variables had a predictive value in the treatment outcome. Twenty-one patients (16%) categorized as nonresponders were compared with 113 patients (47%) considered to be definite responders. On average, the nonresponders had symptoms for 14 years longer than responders. Seventy-eight of 100 patients with complications were female compared with 54% of 190 patients without complications. In addition, patients with complications weighed less than those without complications. Both findings suggest that the occurrence of complications is related to smaller mean neck muscle mass. Botulinum toxin antibodies were detected in 35.7% of the nonresponders tested and in none of the responders. This comprehensive analysis of outcome variables leads us to conclude that patients with a long duration of dystonia before their first botulinum toxin injection respond less well than those with a short duration of symptoms, that some patients lose their responsiveness because of the development of blocking antibodies, and that women are more likely to develop complications, such as dysphagia and neck weakness, than are men.

Adolescent↗
PubMed1990

Injection-corrosion-lavage. Techniques for study and description of vascular anatomy in the hand.

The venous anatomy of the human hand has not been accurately described. Two main reasons for this deficiency in our knowledge are apparent: technical difficulties involved with dissection and imaging of the vessels, and the seemingly limitless number of topographic patterns in this field. This paper introduces firstly, a method for injection and corrosion of hand specimens, and secondly, a routine for describing the venous anatomy, primarily based on their function, and only secondarily on their position or topography.

Hand↗
PubMed1985

Digital venous anatomy.

The veins of the digits and their valves were studied in nine cadaveric hands by sequential angiography, microdissection, routine histology, cross-sectional microradiography, and corrosion casting. The findings revealed a pattern of dorsal venous arches situated over each digit. Connections between those arches were at the level of the metacarpal heads, the point at which most of the palmar venous blood joins the dorsal system by intercapitular veins. A system of valves, which were arranged so as to direct flow from distal to proximal, from palmar to dorsal, and from radial to ulnar in the hand, was present in all veins as far distal as the pulp.

Fingers↗
PubMed1980

Electromagnetic flowmetry--an experimental method for continuous blood flow measurement using a new island flap model.

We describe a reliable experimental method for direct, continuous measurement of the rate of blood flow in an island skin flap, using an electromagnetic flowmeter applied to the artery of the flap. The canine saphenous island flap model, developed as part of this study, is a large (11 x 14 cm) island flap, based solely on the saphenous artery (2 mm in diameter). We describe the anatomy of the flap and the method of raising it. Electromagnetic flowmetry is the only method of blood flow determination that provides immediate, continuous, and quantitative measurement of flow. We describe the principles and pitfalls of the electromagnetic flowmeter and the numerous rules of practice that must be observed to obtain consistent results. A validation study was carried out, in which we simultaneously measured arterial inflow with the flowmeter and venous outflow from the flap using direct collection. This study was based on the assumption that at any point in time the arterial and venous rate of flow were equal. We present the results of the study, which show an extremely close linear relationship between the measured and actual rates of flow. We intend to use this experimental method to study the factors that affect the rate of blood flow in free skin flap transfer.

Animals↗