PubMed Health⌕ Search

Biomedical subjects

W J Peters

Publications and source records attributed to W J Peters.

At least 55 records · Page 3Linked to original sources
PubMed1983

A comparison between cyclosporin A and methylprednisolone plus azathioprine on bronchial healing following canine lung autotransplantation.

The effects of two low-dose immunosuppressive therapies upon the healing of the bronchial anastomosis and skin wounds following lung autotransplantation were evaluated. Autotransplantation was performed in three groups of dogs: Group 1 (nine dogs) received no immunosuppression, Group 2 (seven dogs) received postoperative immunosuppression with methylprednisolone (2 mg/kg) and azathioprine (1.5 mg/kg), and Group 3 (four dogs) received postoperative immunosuppression with cyclosporin A (20 mg/kg/day). Skin incisions 7 cm in length were made in the dorsal region of each dog. Dogs were put to death 23 days postoperatively, and the breaking strength of the bronchial anastomoses and skin wounds was evaluated with the Instron Universal Testing Machine, with a cross-head speed of 0.5 cm/min. Bronchial breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Skin breaking strengths were similar in Groups 1 and 3 and significantly higher than in Group 2 (p less than 0.001). Scanning electron microscopic (SEM) studies of both skin and bronchial wounds showed normal formation of collagen bundles in Groups 1 and 3 but a disorganized pattern in Group 2. Our results suggest that low-dose immunosuppression with methylprednisolone and azathioprine significantly affects wound healing and breaking strength of both bronchial anastomoses and healed skin incisions following canine lung autotransplantation. Immunosuppression with cyclosporin A had no adverse effect on either bronchial or skin healing.

Animals↗
PubMed1981

Inhalation injury caused by the products of combustion.

Inhalation injury results from a type of chemical burn (tracheobronchitis) of the respiratory tract. When this injury occurs in patients with serious cutaneous burns the mortality is exceedingly high- 48% to 86%. The injury can be divided into three types according to the level at which the damage occurs; upper airway, major airway and terminal airway. The early signs and symptoms may be complicated by carbon monoxide poisoning. The patient's condition usually follows a staged progression that is proportional to the extent and severity of the tracheobronchitis. Indirect laryngoscopy, bronchoscopy, scintiscanning of the lung with xenon 133 and serial analysis of arterial blood gases are useful diagnostic techniques. Treatment must be expeditious, and it depends on the severity of the injury. The prophylactic use of antibiotics and steroids is contraindicated.

Animals↗
PubMed1981

The mechanical properties of breast prostheses.

The mechanical properties of inflatable and gel-filled breast prostheses were evaluated using the Instron Universal Testing Machine. Prosthesis strength characteristics were evaluated in terms of compression strength (rather than tensile strength) because of the relationship to closed capsulotomy. The compression breaking strength of prostheses ranged from 0.62 to 10.8 pounds per square inch. There was considerable variation among prostheses. Pressures exceeding these values have been recorded during closed compression capsulotomy. The clinical relevance of these results is discussed.

Breast↗
PubMed1981

Effects of methylprednisolone and azathioprine on bronchial healing following lung autotransplantation.

The effect of low-dose immunosuppressive therapy upon the healing of the bronchial anastomosis and skin wound following lung autotransplantation was evaluated. Autotransplantation was performed in two groups of dogs: Group 1 (15 dogs) received no immunosuppression and Group 2 (13 dogs) received postoperative immunosuppression with methylprednisolone (2 mg/kg) and azathioprine (1.5 mg/kg). Two to four skin incisions 7 cm in length were made in the dorsal region of each dog. Dogs were put to death at 4, 9, 16, and 23 days postoperatively and the bronchial anastomoses and skin wounds were evaluated by breaking strength measurements. Bronchus and skin breaking strength increased with time in both groups. Bronchus breaking strength was similar in the two groups at day 4 and day 9. However, by day 23 bronchus breaking strength was significantly higher in Group 1 (p less than 0.001). Skin breaking strength was significantly higher in Group 1 on days 9 and 16 (p less than 0.005) and on day 23 (p less than 0.001). Our results suggest that low-dose methylprednisolone and azathioprine significantly affect the breaking strength of both bronchial anastomoses and healing skin incisions following canine lung autotransplantation.

Animals↗
PubMed1981

Ivalon breast prostheses: evaluation 19 years after implantation.

Ivalon sponge prostheses, which had been removed from a patient after 19 years, were studied mechanically by light microscopy, by scanning electron microscopy, and by dot map x-ray microanalysis. This study revealed the following. The firmness of these implants was due entirely to their external fibrous capsule, which was 4 to 5 mm in thickness. Once this capsule was incised through, the mechanical compression properties of the implants were identical to fresh unused Ivalon sponge. Contrary to previous observations that Ivalon sponge becomes extensively infiltrated with fibrous tissue, the present implants demonstrated fibrous tissue ingrowth only 2 to 3 mm into the sponge. The open porous nature of the sponge had been preserved after the 19-year implantation period. Whereas extensive calcium and phosphate deposition had previously been demonstrated when Ivalon was implanted into animals, no significant deposition of these ions was observed in the present study.

Breast↗
PubMed1981

Electrical burns; pathophysiology and complications.

The authors review the pathophysiology and complications of electrical injuries. Such injuries can be categorized into direct electrical injuries, arc burns and flame burns. Each has a distinct appearance and prognosis. Nine patients with electrical injuries were admitted to the Toronto General Hospital over the 5-year period 1973 to 1978. All were men and the average age was 33 years. Five patients required amputation. In one patient a convulsive disorder developed 3 weeks after injury. One patient demonstrated peripheral nerve injury with complete axonal lesions of the right median and ulnar nerves; there was progressive full return of nerve function over 12 months. Direct electrical injury to nerves is usually transient and return of function can be expected unless there has been a concomitant thermal or mechanical injury.

Acute Kidney Injury↗
PubMed1980

Biological dressings in burns--a review.

A history of the development of the various biological dressings is presented. Substances currently in use--homografts, heterografts (including amniotic membranes), collagen-based dressings, and synthetic films--are reviewed in terms of their indications for use, method of application, future, and advantages and disadvantages.

Amnion↗
PubMed1979

Cherubism: a study of twenty cases from one family.

A study involving twenty cherubs, members of one family, is presented. The autosomal dominance pattern of inheritance is confirmed, while the penetrance is shown to be 80 percent. Clinical presentation and characteristics are discussed, together with histologic findings which reveal the giant-cell nature of the lesions. Conservative management is advocated, with emphasis placed on avoidance of radiotherapy.

Adolescent↗
PubMed1974

Studies of the stability and toxicity of zinc polyacrylate (polycarboxylate) cements (PAZ).

Zinc polycarboxylate cement (PAZ) was shown to actively bond to 45Ca in vitro, with maximum uptake occurring at a Ca+2 concentration of 0.2 mg/ml. When the resultant PAZ-45Ca complex was subsequently incubated in the presence of high levels of unlabeled Ca+2, there was an exchange between the 45Ca bond to the cement and the Ca+2 in solution. When PAZ prepared using 65Zn was incubated with high levels of Ca+2, there was no exchange between the Ca and the 65Zn. 14C-PA failed to be taken up by L-cells in tissue culture, during 16 division cycles. Using radioactive PAZ prepared from 14C-PA, the PA moiety of the cement was shown to be extremely insoluble and stable in vivo.

Acrylates↗