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Biomedical subjects

V Marshall

Publications and source records attributed to V Marshall.

At least 37 records · Page 2Linked to original sources
PubMed1988

The thigh flap: an osteomyocutaneous free-flap model in the rat.

A new experimental model for free-flap transfer has been developed in the rat. This "thigh flap" is an osteomyocutaneous free flap of bone (femur), muscle (thigh), and skin (groin) based on the femoral vessels. The flap is harvested from the left groin and thigh of an inbred female rat and is transferred to a subcutaneous pocket in the left groin of a male rat of the same inbred strain. The femoral vessels supplying the flap are anastomosed end-to-end with the femoral vessels of the recipient. Thirty flaps have been transferred, with 5 technical failures. Three of the remaining 25 flaps developed necrosis within 24 hours. The other 22 flaps remained viable until the rat was sacrificed at 7 days. The survival rate of the thigh flap was thus 88 percent. The model is suitable for use in metabolic, vascular, and immunologic studies of composite free flaps.

Animals↗
PubMed1987

Prevalence of depression and distress in a large sample of Canadian residents, interns, and fellows.

Using data from 1,805 interns, residents, and fellows in Ontario, Canada, the authors report the prevalence of symptoms measured by the Center for Epidemiologic Studies Depression Scale (CES-D). They found that the proportion of subjects scoring as depressed was somewhat higher than that found in community studies. Women had higher depression scores than men. The proportion of unmarried house staff with moderate or severe depression scores was higher than that of married house staff. Considerable differences were found by specialty, and depression was most prevalent in the first year of postgraduate training. These findings have implications for those who direct postgraduate medical training or who seek to alleviate unnecessary stress in the postgraduate education experience.

Adult↗
PubMed1987

Glomerular epithelial cell lesions in rat renal isografts.

Visceral glomerular epithelial cell lesions--microvillus formation, loss of foot processes, osmiophilic inclusion droplets, balloon-like malformation of cell processes, degeneration, necrosis, and loss of cell processes from capillary basement membranes--are found in rat renal isografts 1 mth after transplantation. The lesions, which are most readily recognized in perfusion-fixed material, are essentially focal, affecting neither all glomeruli, nor all cells in any glomerulus, bear no relation to the degree of interstitial nephritis in the graft, and are associated with albuminuria and with focal capillary sclerosis in some glomeruli. They are not restricted to renal isografts but are found in aging rats, in different experimental models of glomerular disease and in clinical glomerular disorders, again in association with proteinuria and glomerulosclerosis. It is therefore proposed that glomerular epithelial cell damage increases capillary permeability and impairs maintenance of the integrity of the capillary wall, leading to proteinuria and focal glomerulosclerosis.

Animals↗
PubMed1987

Hepatitis B and renal transplantation.

Renal transplantation in HBsAg+ chronic carriers has a relative low risk of progressive liver disease, with mortality associated with liver disease at 7%. In contrast, HBsAg+ recipients who acquired their disease in the early posttransplant period had a mortality of 60%. HBeAg-positive patients who remain persistently positive are a subgroup with a poor prognosis and should not be offered a renal transplant.

Adult↗
PubMed1986

Glomerular damage after kidney preservation.

Severe proteinuria occurs during isolated organ perfusion of kidneys removed from SD and DA rats and subjected to 24-hr cold preservation. In both strains increased glomerular permeability was associated with changes in glomerular visceral epithelial cells, particularly cytoplasmic edema and detachment of cells from capillary basement membranes. Foot processes were intact and staining for sialoglycoprotein was retained. The changes were compatible with survival of the isograft kidney after transplantation, but moderate proteinuria was found in some rats after one month. Protein loss in the urine during isolated organ perfusion is very much less in kidneys subjected to 4-hr cold preservation, and the glomerular epithelial cells are normal or show only minimal cytoplasmic edema on electron microscopy. The experiment shows that significant damage to glomeruli may occur during preservation prior to transplantation, and the model itself can be usefully exploited to determine the relation between increased glomerular permeability to albumin and the associated changes in the glomerular capillary wall.

Animals↗
PubMed1985

The influence of the contralateral kidney upon recovery from unilateral warm renal ischemia.

Unilateral warm renal ischemia of 90 min duration was induced in rats and the contralateral normal kidney was removed either immediately or after 1, 2, 4 or 14 d. Contralateral nephrectomy at 2, 4, 14 d increased survival and modified the functional and morphological events of the recovery period. Optimal recovery was obtained by 4 d delay. When contralateral nephrectomy was delayed by 14 d, scarring of the ischemic kidney was more severe suggesting that regeneration of damaged nephrons was impaired when renal homeostasis was sustained by the contralateral kidney. Such biphasic and inverse effects of normal kidney tissue are likely to be important determinants of the natural history of severe unilateral renal damage.

Animals↗
PubMed1984

Monitoring response to chemotherapy of intact human tumours by 31P nuclear magnetic resonance.

10 kidneys bearing adenocarcinoma (hypernephroma), 1 ureteric tumour, 2 Wilms' tumour from patients undergoing nephrectomy, and normal human and animal kidneys were preserved and later tested to see whether normothermic blood perfusion restored glomerular filtration, oxygen consumption, and energy metabolism, as monitored by 31P nuclear magnetic resonance (NMR). NMR spectra of normal human kidney and of renal tumours were characteristic of kidney in other species (rat, rabbit, and dog), with six principal resonances assigned to adenosine monophosphate, inorganic phosphate (Pi), glycerophosphoryl choline, gamma, alpha, and beta adenosine triphosphate and an intrarenal pH 7.0-7.2. 7 out of 9 hypernephromas and 1 of the 2 Wilms' tumours produced an additional resonance at +4.2 ppm. This peak was absent from all normal kidney spectra and may represent Pi in a specific and highly acidic environment (pH 6.1-6.5) found in actively metabolising human tumours. Furthermore, in 1 tumour (out of 5 tested) the +4.2 ppm peak rose rapidly after the addition of chemotherapeutic agents to the perfusing blood. This observation may indicate drug sensitivity of this one tumour. The results suggest that 31P NMR imaging may be used to monitor therapeutic response during regional perfusion of malignant tumours in man.

Animals↗
PubMed1984

Diaphanography as a means of detecting breast cancer.

Diaphanography (lightscanning) is a noninvasive method of examining the breast by transillumination using visible or infrared light. It was compared to xeromammography in 1,000 patients, 91 of whom had biopsy. There were 34 malignant tumors, of which 29 were detected by xeromammography and 26 by lightscanning; 27 patients with positive lightscans were not biopsied. All patients with true-positive lightscans also had positive mammograms. Major criteria of malignancy on diaphanography included an area of light absorption and abnormal or hypervascularity. These criteria could be demonstrated on retrospect on 6 scans previously considered negative; one xeromammogram previously interpreted as negative was diagnosed as positive on retrospect. Diaphanography may be sensitive enough to warrant further investigation.

Adolescent↗
PubMed1982

Organ and tissue transplantation: past, present and future.

Organ and tissue transplantation are now clinical treatment options for irreversible failure of many organs and systems. Living related donors or cadaver donors are used in kidney transplantation and it is a well-established procedure with defined results. Cardiac graft results match those obtained for recipients of unrelated kidney grafts from cadavers. Combined heart and lung grafts have been successfully used to treat cor pulmonale. Liver transplantation is technically demanding, and suffers from the absence of effective liver-support systems, but can achieve lifesaving short-term and long-term survival in selected patients. Pancreatic transplantation offers great potential, but long-term results both of isolated islet-cell transplantation and of organ grafts have been disappointing. Lung transplantation as an isolated procedure has had very little success. Bone-marrow transplantation is now the method of choice of treatment of aplastic anaemia, and is occasionally successful in management of malignancies. Transplantation of skin, bone, cartilage, endocrine, and vascular tissues has a variety of important clinical applications. Corneal transplantation has the longest successful history of all allografts.

Bone Marrow Transplantation↗
PubMed1981

Renal transplantation--15 years' experience.

In Australia, it has been logistically possible, with integrated programmes of dialysis and transplantation, to use finite resources optimally for the treatment of patients presenting with terminal renal failure (30 per million population per year). Transplantation is offered as definitive treatment in most instances. Transplantation rates (20 per million per year) will need to increase to meet the continuing demand, if the results of transplantation remain unchanged. Patient survival after transplantation is approximately 80 per cent at year, 50 per cent at 5 years and 20 per cent at 15 years. Most grafts are from cadavers. Graft survival of 60 per cent at 1 year thereafter declines steadily with a 3 per cent graft loss per year. Patient and graft survival are adversely affected by increasing age, and the use of cadaver rather than living donors. Graft survival is superior with a 4 antigen match on HLA A and B matching, and is significantly lower in patients receiving no blood transfusions prior to transplantation. Long term morbidity is significant in two-thirds of patients receiving grafts. Problems include chronic rejection and toxic effects of immunosuppression. The increased tumour risk after transplantation (which in Australia has been mostly skin tumours) is of major concern; 30 per cent of patients by 10 years have developed cancer.

Adult↗
PubMed1981

Prospects for training of Australian surgeons in Britain.

Britain has remained the country most favoured by Australian and New Zealand surgeons for overseas training. Post-fellowship training in Britain is advantageous in both service and research posts. Increase in personal operative experience, and the development of a special interest within general surgery are facilitated. Exchanges of surgical trainees between Australasian and British programmes can also be mutually advantageous, particularly during advanced training. College regulations and accreditation of surgical programmes in each country should remain sufficiently flexible to facilitate such exchanges.

Australia↗
PubMed1980

Evaluation of citrate flushing solution using the isolated perfused rat kidney.

The isolated rat kidney perfused at 37 C with dialyzed bovine serum albumin (6.5 g/100 ml) in Krebs-Henseleit buffer was used to examine why a hypertonic citrate flush permits rapid recovery of renal function after storage. The composition of the original hyperosmolar citrate solution was varied so that the roles of osmolality, magnesium, and citrate could be evaluated. All kidneys were flushed with the test solutions and stored for 24 hr in the test solutions at 0 C. The citrate flushing solution requires both the citrate anion and magnesium for efficacy. Hyperosmolality does not enhance its action, an isosmolar solution is more effective. Citrate can be replaced by a nonmetabolizable analogue, tricarballylate, if the solution is suitably buffered. The mechanism of action of citrate is still uncertain, it does not seem primarily to act as a metabolic fuel or inhibitor.

Animals↗
PubMed1979

Retained gallstones: the choice of the method of management.

The management of 26 patients with retained stones in the biliary tree after surgery is described. Various methods have been used, but intermittent rapid flushing with one litre of isotonic saline solution, together with a slow infusion of heparin solution via the T tube, was the most successful. It required no specialized equipment, and is recommended as the first choice in treatment.

Adult↗