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Biomedical subjects

M Tonkin

Publications and source records attributed to M Tonkin.

16 recordsLinked to original sources
PubMed2005

Transpiration-assisted perfusion fixation provides in situ preservation of developing ray parenchyma cells in Eucalyptus nitens.

The technique of animal vascular perfusion fixation was adapted for in situ fixation of the fragile and difficult to access cells of the ray parenchyma system in stems of 10-year-old Eucalyptus nitens trees. In situ fixation enabled tissue to be safely dissected for histological processing without risk of damage to microstructure or initiation of wound response. Fixative was perfused through the active vascular system under hydrostatic and transpiration pressure directly to vessel-associated ray cells. Diffusion from vessels allowed fixative to access nonvessel-associated ray cells. Acrolein was included to aid diffusion fixation and safranin dye was included to define fixed regions within the xylem. Sections prepared for light and electron microscopy from samples cut from regions showing intense safranin staining showed good microstructural preservation and were free of artefacts caused by mechanical injury or wound response.

Eucalyptus↗
PubMed2001

Redefining leadership responsibilities following organizational redesign.

A redefinition of leadership roles was necessitated by the adoption of program management, which accompanied the merger of two large academic hospitals, each of which consisted of two sites. Directors of professional departments were removed when staff were deployed to programs. Program directors were selected to manage the new programs, and profession leaders were identified to monitor standards of practice. The roles and accountabilities of the new program and profession leaders needed to be clarified for incumbents and other hospital staff. This article describes the process undertaken to clarify those responsibilities. The resulting Guide outlines 14 specific and collaborative responsibilities of program and profession leaders. Plans for review and future development of the Guide are discussed.

Guidelines as Topic↗
PubMed1992

Cholera vaccination: a decision analysis.

OBJECTIVE: To examine the clinical impact and financial cost of a vaccination program for the prevention of cholera in North Americans travelling to endemic and epidemic regions by means of the principles of decision analysis and a decision tree as well as to illustrate the effect of case attack rates on the cost per case prevented by vaccination. DESIGN: Review of the scientific literature to establish the probabilities of each significant outcome as well as a decision analysis and partial economic evaluation. OUTCOME MEASURES: Clinical impact (attack rates for cholera among vaccinated and nonvaccinated travellers), rates of death associated with cholera and vaccine-associated adverse events (VAAEs), and the number of VAAEs and the vaccine cost per case prevented. MAIN RESULTS: On the basis of our assumptions (including a rate of one case of cholera per 500,000 journeys to endemic regions), to prevent one case of cholera a vaccination program would cost $28.67 million and be associated with 105 VAAEs. CONCLUSION: Routine vaccination of travellers to endemic areas cannot be recommended; however, for people travelling to regions with a high transmission rate vaccination should be considered.

Cholera↗
PubMed1992

Surgery for cerebral palsy: Part 1. Classification and operative procedures for pronation deformity.

32 patients with cerebral palsy underwent operations for pronation deformity. The deformity is classified into four groups. Patients in group 1 are capable of supination beyond neutral. No surgery is necessary. Those in group 2 are able to supinate to the neutral position. A pronator quadratus release is advised and may be combined with a flexor aponeurotic release. In group 3, patients have no active supination. However a full range of passive supination is readily achieved. A pronator teres transfer is advised. Patients in group 4 have no active supination. Full passive supination may be present, but is tight. A flexor aponeurotic release and a pronator quadratus release may unmask active supinator activity. An active transfer for supination is possible as a secondary procedure.

Adolescent↗
PubMed1990

Results of primary tendon repair with closure of the tendon sheath.

This study reports the results of primary flexor tendon repair combined with closure of the tendon sheath in 31 Zone 2 injuries. In 3 digits, the profundus tendon alone was divided. In a further 7 digits, one tendon was completely divided and the other was incompletely divided. The remaining 21 digits involved complete division of both tendons. Assessment of the results according to the total active motion (TAM) system found 86% of the repairs in the excellent, good and fair categories. Two ruptures occurred (6%). A second assessment employed the criteria of Strickland, excluding the motion of the metacarpophalangeal joint. The results obtained following suture of both tendons were: excellent (39%); good (36%); fair (14%); poor (4%); and rupture (7%). These results lend support to the belief that closure of the tendon sheath decreases external adhesion formation and improves motion without increasing the risks of rupture.

Adult↗
PubMed1988

Post-operative management of flexor tendon grafting.

This paper reviews the post-operative management of 145 tendon grafts in 127 patients. 80 grafts were managed post-operatively by a period (three to four weeks) of immobilisation followed by gentle active mobilisation. 65 grafts were managed by immediate controlled mobilisation (Kleinert technique) for three to four weeks. The final motion obtained was independent of the post-operative management. However, the rates of graft rupture (nine against four) and of tenolysis (sixteen against eight) were higher in the immobilised group.

Female↗
PubMed1986

Flexor tendon surgery--today and looking ahead.

The biology, management, and results of primary repair and secondary reconstruction are reviewed. Repair of the tendon sheath and controlled mobilization appear to improve the results of both groups.

Finger Injuries↗
PubMed1986

Vascularized fibular epiphyseal transfer. A clinical study.

In a review of the experimental and clinical literature on nonvascularized and vascularized epiphyseal transfer, experience with eight patients with free vascularized fibular epiphyseal transfer suggests that transfer of bone with an open epiphysis offers some potential for growth in either congenital abnormalities or epiphyseal arrest secondary to trauma and infection. In four cases, premature epiphyseal closure prevented appreciable growth. In the other four, the epiphyses remain open and the transferred bones continue to grow. Although the procedure is experimental, the results of combined epiphyseal and metaphyseal vessel transfer with a skin island as a monitor of viability, warrant further investigation.

Arm↗
PubMed1981

Short- and long-term therapy of mild essential hypertension with timolol.

The short and long-term antihypertensive action of timolol, a beta blocker, was assessed in 36 mild hypertensives in a 32-wk, double-blind, placebo-controlled study followed by an additional 96 wk of timolol in 17 responders. Diastolic blood pressure (DBP) and heart rate (HR) declined during the first phase from 103 to 93 mm Hg and from 73 to 61 bpm (P less than 0.01) but there was long-term timolol subjects (DBP 89 mm Hg at 32 wk and 88 mm Hg at 96 wk [NS] and HR 62 and 65 bpm [NS]). Although stimulated plasma renin activity in the entire group decreased from 1.08 to 0.28 ng/ml/hr (P less than 0.001), blood pressure reduction did not correlate with this decline (r = 0.29) or with serum timolol level (r = 0.29). In 20 patients who underwent treadmill was not altered. Thus, timolol is effective in reducing mild high blood pressure during short-term therapy and in maintaining this effect over the long term in responsive subjects. It is therefore potentially useful in chronic essential hypertension.

Adult↗