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Biomedical subjects

J C Tanner

Publications and source records attributed to J C Tanner.

At least 19 recordsLinked to original sources
PubMed1997

Implementation of parameters in the expansion ratio of mesh skin grafts.

Expansion of a mesh skin graft depends on factors pertaining to the graft itself as well as on parameters of the meshing device. With regard to the graft, we examine the efficiency of graft handling and thickness of the skin graft. With regard to the parameters of the meshing apparatus, which determine the expansion ratio: (1) d equals the distance between the cutting blades, which will become the width of the mesh ribbons and is an underestimated parameter for expansion; and (2) L equals the length of cut, which determines proportionally the expansion ratio. This length defines the maximal distance of the raw square of the expanded mesh and therefore the healing time by epithelialization. The authors present a mathematical formula of expansion ratio that allows for an objective comparison of skin meshing apparatuses. It is concluded that optimal mesh skin grafting is based on mathematical principles rather than on inventive instrumentation. Furthermore, an analysis of the mechanical parameters as given by the manufacturers is important in anticipating healing time per expansion ratio.

Humans↗
PubMed1995

Reducing age at first calving in N'Dama heifers using groundnut cake as a supplement to grazed natural pasture in The Gambia.

N'Dama heifers, initially weighing 129 kg at approximately 30 months of age, were supplemented with 250, 500 or 1000 g/head/day groundnut cake for 3 or 6 months during the dry or dry and wet seasons. Highly significant improvements in rates of liveweight gain and reproductive performance were obtained. Supplementation during the dry season only, approximately trebled the proportion of animals calving within 2 years of the beginning of the trial (6 vs 20%, P < 0.05), while this increase was around eight-fold in the animals that continued to receive supplement during the wet season (6 vs 50%, P < 0.05). Conceptions occurred at an overall mean liveweight of 185 kg, and a "target" liveweight of 200 kg for the first conception of N'Dama heifers is proposed as the basis for husbandry recommendations concerning these animals. It is concluded that such intervention can reduce the usually observed age at first calving of village based N'Dama heifers by 12 months, in a fashion that is both practicable and financially advantageous.

Aging↗
PubMed1995

A review of skin meshers.

Before the widespread clinical acceptance of mesh skin grafting, expansion of full thickness skin had already been reported. The senior authors, who performed the first mesh skingrafts, have tried several variations of instruments starting with a flat block, later using a roller device with staggered cuts (Mesh Dermatome type I), and further a roller with continuous cuts and a grooved carrier (Mesh Dermatome II). Now interchangeable rollers for different expansions (Zimmer Skin Mesher) and several other genuine meshers are available. Other innovations from the literature are mentioned. This article gives a classification and details of the different models. The basic principles are reviewed. A general formula is presented, allowing objective comparison of skin meshers.

Animals↗
PubMed1990

Photoelectric plethysmography in monitoring skin circulation.

Photoelectric plethysmography is not new, but is a simple noninvasive technique to determine erythrocyte volume and oxygen saturation. The data are immediately available, accurate, repeatable, and recordable. Methods currently used for estimating microcirculation and oxygen saturation include clinical tests such as observation of skin color, temperature changes, capillary refill, and bleeding; chemical tests such as fluorscein injection; radioactive isotopes (24Na, 131I, 99mTc, and 133Xe); and instrumental methods (both invasive and noninvasive) such as temperature and infrared thermometry, thermocouples, oxygen probes, and/or the plethysmometer. None of these methods is entirely satisfactory.

Amplifiers, Electronic↗
PubMed1978

Hair transplantation using local hypothermia.

The frequency of hair transplantation for treatment of male alopecia is increasing, and much time is consumed in free scalp plug removal and implantation. The amount of time depends upon the number of grafts required. Plugs ranging in diameter from 2 to 4 mm are recommended since larger sizes have increased fibrosis and decreased hair growth. Composite grafts show greater survival when cooled; therefore, a method of local hypothermia and 5.5 mm scalp plugs were used in this study. The lowered temperature of the recipient site during the early postoperative days permitted the use of the larger grafts without fibrosis, hematoma, or infection and with improved hair growth. This technic allows better quality of hair growth, requires fewer hair plugs, and decreases operating time.

Alopecia↗
PubMed1976

Correction of extensive neck contractures with local flaps and split- and full-thickness grafts.

A technic of combined split-thickness and full-thickness skin grafts and local flap closure for extensive deep cicatricial neck contractures is presented. The head and neck are mobilized by excision of limiting tissues. The lateral neck skin is mobilized to be rotated anteriorly as flaps, and a full-thickness skin graft is applied to the central neck. Split-thickness skin grafts are placed below the full-thickness graft and flaps, and also above the full-thickness graft over the horizontal part of the neck. The success of this technic relies upon the limited contracture of full-thickness skin grafts, mobilization of lateral neck tissue, and consideration of regional units of the neck. This relatively simple operation results in a dramatic and lasting improvement of the neckline, good range of motion of the head and neck, elimination of multiple operative procedures, and early rehabilitation of the patient.

Cicatrix↗