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Biomedical subjects

R C Smith

Publications and source records attributed to R C Smith.

At least 235 records · Page 13Linked to original sources
PubMed1986

Injectable silicone for facial soft-tissue augmentation.

Medical-grade injectable silicone has been safely and efficiently used for facial soft-tissue augmentation in 235 patients. Our 20-year experience with the microdroplet technique included 2,811 treatments performed for camouflaging furrows and grooves, augmentation of facial eminences, and elevation of certain depressed scars. The indications and techniques of injection are discussed. The augmenting effect is greater than that produced by the small volumes of silicone injected. Our study supports other work indicating induction of collagen deposition in the patients around the microdroplets of silicone, thus providing augmentation from volumes of collagen and silicone as well.

Adult↗
PubMed1986

Organisation of Xenopus egg cytoplasm: response to simulated microgravity.

The cytoplasm of Xenopus fertilised eggs appears to be organised into three major compartments based primarily on the uneven distribution of yolk platelets. There is a shift of these yolk compartments during the first cell cycle that is thought to be involved in the dorsal/ventral morphogenesis of the embryo. The involvement of gravity in Xenopus cytoplasmic organisation and in compartment shifts was addressed by examining, cytologically, the yolk compartments in embryos that developed under the simulated microgravity conditions of the horizontal clinostat. The cytoplasmic organisation into yolk compartments was found to be maintained, and the asymmetric movements of compartments still occurred in eggs that developed on the clinostat. It is suggested that the organisation of Xenopus egg cytoplasm into discrete compartments relies on forces other than those involving gravity (i.e., not density differences), and that the compartment shifts that take place during the first cell cycle are active movements. The variation in compartment size and composition observed from batch to batch of eggs, and to a lesser extent from egg to egg, during this study was addressed.

Animals↗
PubMed1986

Studying the meaning of dreams: accurate definition of the independent variable.

Studying the meaning of dreams is difficult and subject to many methodological pitfalls. One of these is vagueness and inconsistancy in defining dream content variables that are used as independent measures. This study evaluated the effect, upon accurate definition of the independent variable, of repeating the dream report and of using associative content as dream material. The importance of controlling these two sources of dream material was demonstrated: when the patient was allowed to repeat the dream and to report associative content, the number of initial references to death and separation variables nearly doubled in comparison to the standard single report of manifest content. Furthermore, there was minimal or no correlation of the number of these variables between manifest content and associative content, providing additional evidence for the unique contribution of associative content. This article also describes a new interview technique, the Staged Interview Technique, which provides a means to control, as well as measure, these potential distortions of the independent variable.

Adult↗
PubMed1986

Amphibian egg cytoplasm response to altered g-forces and gravity orientation.

Elucidation of dorsal/ventral polarity and primary embryonic axis development in amphibian embryos requires an understanding of cytoplasmic rearrangements in fertile eggs at the biophysical, physiological, and biochemical levels. Evidence is presented that amphibian egg cytoplasmic components are compartmentalized. The effects of altered orientation to the gravitational vector (i.e., egg inversion) and alterations in gravity force ranging from hypergravity (centrifugation) to simulated microgravity (i.e., horizontal clinostat rotation) on cytoplasmic compartment rearrangements are reviewed. The behavior of yolk compartments as well as a newly defined (with monoclonal antibody) non-yolk cytoplasmic compartment, in inverted eggs and in eggs rotated on horizontal clinostats at their buoyant density, is discussed.

Animals↗
PubMed1986

Prevention by antioxidants of the hemolysis of erythrocytes of cattle, pigs and humans treated with t-butyl hydroperoxide.

Urate, 3-ribosylurate, ascorbate, glutathione and plasma protected bovine, porcine and human erythrocytes from hemolysis caused by t-butyl hydroperoxide (t-BHP). Urate partially protected porcine erythrocytes from hemolysis by t-BHP when it was added 15 min after the addition of the t-BHP, but it did not protect when added 30 min after the t-BHP. Glutathione and ascorbate protected oxyhemoglobin from oxidation to methemoglobin by t-BHP; 3-ribosylurate gave only slight protection. Urate stimulated the formation of methemoglobin from oxyhemoglobin during treatment with t-BHP.

Animals↗
PubMed1986

Cigarette smoking and face lift: conservative versus wide undermining.

The effects of cigarette smoking on the skin flaps of the face lift procedure are discussed. Reported elsewhere is a significant incidence of skin slough in smokers with use of wide undermining techniques. This complication is thought to be due to the vasoconstrictive effects of nicotine on the peripheral circulation. Our group has employed a conservative bilateral undermining technique in 407 face lifts. Of these, 32.4 percent were smokers and 67.6 percent were nonsmokers. No cases of skin slough were encountered. Our conservative undermining technique is briefly discussed. Among its advantages are shorter operative time, use of less local and/or general anesthesia, less intraoperative bleeding, adequate exposure for SMAS and platysmal surgery, and snugger skin closure without the risk of flap necrosis. As shown by our statistics, it is a safer procedure in smokers than the usually performed more radical procedure.

Face↗
PubMed1986

Prediction of postoperative complications by clinical and nutritional assessment.

This study evaluated a battery of nutritional measures and pre-operative clinical assessment as predictors of postoperative morbidity. Fifty-seven consecutive patients about to undergo major elective abdominal or thoracic surgery were surveyed. Thirty-two per cent of patients had three or more abnormal measurements of nutritional indices. Thirty patients had a total of 52 complications and in 12 patients these were major. The Prognostic Nutritional Index (PNI), formulated by Mullen, was found to be the best predictor of postoperative outcome. It identified 10 of 12 (83%) patients who subsequently developed major complications with a specificity of 73%. Clinical assessment selected six of the 12 patients who developed major complications.

Abdomen↗
PubMed1986

In situ carcinoma of the pancreas.

Two cases of pre-invasive in situ carcinoma of the pancreas treated by surgery are reported. In each case the resection was carried out because of the probable diagnosis of invasive carcinoma of the pancreas. In situ carcinoma of the pancreas is not included in standard clinical classifications of pancreatic cancer. This is an important omission because of the prognostic implications of this diagnosis, and because of the difficulties in interpreting fine needle aspiration cytology or histology on needle biopsy in such cases.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1986

Supraorbital and supratrochlear notches and foramina: anatomical variations and surgical relevance.

The anatomy of the supraorbital and supratrochlear notches and foramina has been studied in 111 human skulls. Of 108 skulls, 49.07% had bilateral supraorbital notches, 25.93% had bilateral supraorbital foramina, and 25% had a notch on one side and a foramen on the other side. Of 101 skulls, 97.03% had bilateral supratrochlear notches, 0.99% had bilateral foramina, and 1.98% had a notch on one side and a foramen on the other side. The methods of study and clinical relevance are discussed, along with the varying nomenclature used in the literature for defining the supraorbital and supratrochlear structures. Knowledge of the anatomy of the region is important for those doing forehead and brow lift surgery in order to avoid injuring the neurovascular bundles passing through these notches and foramina.

Cephalometry↗
PubMed1986

Protein synthesis and messenger RNA levels along the animal-vegetal axis during early Xenopus development.

The patterns of proteins synthesized in animal and vegetal regions of Xenopus oocytes, eggs and embryos were examined by 2D gel electrophoresis. In oocytes and eggs, the only proteins synthesized asymmetrically along the animal-vegetal axis were a small number of proteins synthesized predominantly in the vegetal hemisphere. At the cleavage stage there were a total of four proteins synthesized unevenly in animal and vegetal regions: three synthesized predominantly in the vegetal hemisphere and one synthesized predominantly in the animal hemisphere. By the gastrula stage, when maternal messages have largely been replaced by embryonic transcripts, the number of differences in proteins synthesized in the animal-derived ectoderm and mesoderm, and the vegetal-derived endoderm started to increase rapidly with time of development with many more animal-characteristic proteins than vegetal-characteristic proteins appearing. Comparison of protein synthesis patterns with those obtained when extracted RNA was translated in vitro and run on 2D gels, showed that the asymmetry in protein synthesis along the animal-vegetal axis in the oocyte and early embryo reflected directly the distribution of their mRNAs along the axis. There was no evidence for localized 'masked' abundant messages along the animal-vegetal axis of oocytes and cleavage embryos.

Animals↗
PubMed1985

Skin wound approximation with new absorbable suture material.

A new rapid strength loss catgut suture material can be used for skin closures in wounds of the face and body. Seventy-six comparisons were made under controlled conditions between the new material and one formerly recommended. The new material was used in 588 other wounds as well. It is concluded that the new material is superior to the other in several important ways.

Catgut↗
PubMed1985

Use of the fluorochrome propidium iodide for the identification of Xenopus germ plasm during immunofluorescence studies.

Addition of 0.5 microgram/ml of the red fluorescent dye propidium iodide to the penultimate wash of Xenopus early embryo serial sections during immunofluorescence studies causes germ plasm to fluoresce brightly. Germ plasm can be accurately and speedily identified in the serial sections. The use of this dye is a marked improvement over previous methods of germ plasm identification in unstained sections. Studies involving screening for germ-plasm-specific antibodies are greatly facilitated by staining germ plasm red with propidium iodide and searching for green colabelling by fluoresceinated antibodies.

Animals↗