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Biomedical subjects

W J Peters

Publications and source records attributed to W J Peters.

At least 37 records · Page 2Linked to original sources
PubMed1990

An early surgical approach to burns in the elderly.

This study evaluates our experience with an early surgical approach in 52 consecutive patients over the age of 65 years. Eighteen patients were taken to the operating room for early excision (less than 7 days postburn) and 34 patients were excised after 7 days (late excision). The early and late excision groups were matched for age, sex, and size of burn. In survivors, the early excision group had a 32% reduction in mean hospital stay (p less than 0.05). In addition, early surgical excision resulted in fewer episodes of sepsis and pneumonia (p less than 0.05). However, there was no significant improvement in age- and burn size-specific survival in the early excision group (p greater than 0.05). We conclude that elderly patients represent a high-risk population, and that early surgical excision results in fewer episodes of infection and a reduction in hospital stay but does not significantly improve survival.

Aged↗
PubMed1989

Increase of serum interleukin 2 receptor level in thermally injured patients.

Serum concentrations of receptor for the T cell growth factor interleukin 2 (IL-2R) were compared to the capacity of activated T cells to express surface IL-2R in patients with major burns. In immunosuppressed patients the numbers of cells expressing IL-2R were transiently (survivors) or permanently (nonsurvivors) reduced (up to 50 and 90%, respectively). In contrast, the levels of soluble IL-2R in patients' sera were significantly (P less than 0.001-0.05) elevated throughout the postburn period. Within 24 hr postinjury, over 90% of patients demonstrated 400-3500 U/ml of serum IL-2R compared with 120-340 U/ml in normal controls. Soluble IL-2R, when patients became immunosuppressed, further increased to 4445 +/- 962 U/ml in nonsurvivors and to 2031 +/- 578 U/ml in survivors, and demonstrated a significant capacity to inhibit the activity of exogenous IL-2. In survivors the levels of serum IL-2R declined at discharge, to 1009 +/- 104 U/ml. Thus, in thermally injured patients, soluble IL-2 receptor concentrations are elevated, and could interfere with IL-2-mediated immune interactions.

Adolescent↗
PubMed1989

Regulation of IgM production in thermally injured patients.

This report examines the capacity of autologous and exogenous interleukin-2 (IL2) to regulate and/or induce immunoglobulin M (IgM) production in these patients. Pokeweed mitogen (PWM)-induced lymphocyte proliferation and PWM- and IL2-induced IgM secretion were monitored in vitro during the postburn period (10 to over 60 days) in 40 patients aged 16-72 years, with burns 20-90 per cent TBSA. PWM-induced IgM secretion fluctuated considerably during this period. Twelve of 40 patients demonstrated no IgM production and a significant (P less than 0.001-0.05) proportion of them had profoundly suppressed levels. Of the survivors, restoration of IgM secretion to normal levels was achieved in only 60 per cent at time of discharge. Even more consistently suppressed was exogenous IL2-driven production of IgM. In contrast, PWM-induced lymphoproliferation was normal in over 70 per cent of the patients. Thus, the T-cell-dependent antibody response was suppressed for long periods of time, possibly from some deficiency in IL2-regulated secretion or reception of helper T-cell-derived factors necessary for B cell differentiation into Ig-secreting cells.

Adolescent↗
PubMed1989

Advances in burn scar reconstruction: the use of tissue expansion.

The use of tissue expansion to facilitate burn scar reconstruction is described. Twelve patients underwent burn scar reconstruction using a total of 42 expanders. Expansion was carried out at two- to three-day intervals, usually commencing as early as two to three days following insertion of the expander. In 5 of the 12 patients, previously scarred skin was expanded to facilitate excision of areas of more dense scarring and scar contractures, more conventional methods having previously failed. Two of the expanders failed to achieve adequate expansion because of exposure of the device. One of the patients in whom the expander failed refused to have it reinserted. Complications included implant exposure (9 of 42), injection port exposure (1 of 42), infection (4 of 42), and a transient facial nerve palsy in 1 patient who was having her cheeks expanded. Except for one case, implant exposure did not preclude continued expansion and ultimate reconstruction.

Adult↗
PubMed1988

Interleukin-2 secretion and transmembrane signalling in burned patients.

IL2 secretion in response to the T-cell mitogen Staphylococcal protein A (SPA) is significantly decreased in patients with major burns (n = 10, greater than 20% total body surface area) up to 50 days postburn in comparison with normal control (greater than 2 to 10 U/ml and 16 to 36 U/ml, respectively). Activation of protein kinase C (PK-C) and changes in [Ca++]i are both normally implicated in the production of IL2. Bypassing the requirements for mitogen-induced increases in [Ca++]i, using the cation ionophore A23187, or activating PK-C with the phorbol ester 12-o-tetradecanoyl-phorbol-13-acetate (TPA), failed to significantly restore SPA-induced IL2 production in cell cultures from burned patients. The combination of A23187 and TPA significantly (p less than 0.005-0.001) enhanced IL2 secretion in patients' cell cultures (range, 20 to greater than 64 U/ml). However, the levels of IL2 from the burned patients' cultures remained significantly lower (p less than 0.05) than those in control cultures exposed to TPA and A23187 (range, 256 to greater than 600 U/ml). Therefore, the burn-related defect in mitogen-induced IL2 secretion is only partially bypassed with cation ionophores and phorbol esters. This suggests that the abnormality in IL2 production may not be solely related to changes in PK-C activation and in [Ca++]i but may reside in other than transmembrane signalling mechanisms required for IL2 production.

Adult↗
PubMed1988

Factors influencing energy expenditure in patients with burns.

Twenty-three consecutive patients with a mean burn size of 39% of total body surface area (%TBSA) were studied prospectively. Expected basal energy expenditure (EBEE) calculated by the Harris-Benedict formula, initial and twice weekly measurements of energy expenditure (MEE) by indirect calorimetry, and simultaneous estimation of nutrient intake were obtained. In the whole cohort the EBEE was 1,715 +/- 24 kcal/day and the MEE was 2,218 +/- 59 kcal/day. The degree of hypermetabolism was 29.0 +/- 2.8%. A subgroup of 16 patients had metabolic rates measured in both the fed and unfed states. The degree of hypermetabolism was only 6.5 +/- 4.5% in the unfed, but increased to 34.1 +/- 3.2% when the same patients were fed (p less than 0.001). The factors affecting MEE were then evaluated by stepwise multiple regression analysis which showed that MEE = -4343 + (10.5 X %TBSA) + (0.23 X Caloric intake [CI]) + (0.84 X EBEE) + (114 X Temp [C]) - (4.5 X Postburn days), r = 0.82, p less than .001. We conclude that 25% of the CI is used to increase the MEE, which suggests that these measurements done in the fasting state cannot be used to predict requirements.

Adult↗
PubMed1987

Severe peripheral burn polyneuropathy: a case report.

This report describes a 30-year-old man with a 45 per cent mixed deep partial and full thickness flame burn, who--following sepsis and multisystem failure--developed a severe polyneuropathy affecting the left median and both ulnar nerves, and both peroneal and posterior tibial nerves. The neurological alterations were significantly reversible, early reinnervation in all limbs was demonstrated by electromyography at 8 months, with subsequent progressive reinnervation at 1 year. The most likely cause of this polyneuropathy was the acute development of uraemia, at day 33 post-burn.

Adult↗
PubMed1987

Acalculous cholecystitis in association with major burns.

Three cases of acute acalculous cholecystitis are presented, from a retrospective study of approximately 380 consecutive patients admitted to a regional adult burn centre. Two patients were male, one female. The mean body surface area (BSA) burn was 41 per cent, with a mean full thickness injury of 36.7 per cent. All patients survived but had markedly prolonged hospital stays. All patients demonstrated predisposing factors associated with acalculous cholecystitis; extensive burn area, multiple transfusions, bacteraemia, total parenteral nutrition (TPN), narcotic analgesics, and positive pressure ventilation. One patient required only conservative treatment. The other patients required surgical cholecystectomy. Cholecystostomy may have a role in critically ill patients.

Adult↗
PubMed1987

Impaired expression of interleukin-2 receptor (IL2R) in the immunosuppressed burned patient: reversal by exogenous IL2.

The capability of exogenous recombinant Interleukin 2 (rIL2) to increase expression of the IL2 receptor (IL2R), and to augment the in vitro proliferative response of lymphocytes from immunosuppressed burned patients (5-80% full-thickness burns) was examined. Throughout the postburn period the percentage of IL2R-bearing cells in Concanavalin A-activated cultures of patients' peripheral blood mononuclear cells (PBMC) was measured by direct immunofluorescence with monoclonal anti-IL2R antibodies. Mitogen-induced IL2R expression was decreased by 40-90% in cultures of patients' PBMC, parallel to their reduced alloreactivity. During this period of immunosuppression supplementation of the mitogen-activated cultures with recombinant IL2 (20 U/ml) significantly increased the number of IL2R-expressing cells in all patients studied. However, IL2-induced enhancement of blastogenesis in the MLR was observed only with the patients who, in mitogen-activated cultures, sustained numbers of IL2R-endowed cells at least 50% of their baseline (the level within the first 24 hours postburn). Also, unstimulated PBMC of the same responding patients demonstrated a restoration of proliferation in the presence of rIL2. These patients were survivors. Thus the proliferative response correlated well with the number of Con A- but not rIL2-induced IL2R-expressing cells. These results suggest that in burned patients, IL2 up-regulates its receptors, but they may represent low-affinity nonfunctional receptors. Thus thermal injury appears to affect expression of functional (high-affinity) receptors.

Adolescent↗
PubMed1986

Polyclonal immunoglobulin production in burned patients--kinetics and correlations with T-cell activity.

Spontaneous and pokeweed mitogen (PWM)-induced polyclonal immunoglobulin production in vitro were estimated in patients with severe burns (28-83% TBSA) immediately following their injury and at intervals of 8 to 14 days thereafter. In parallel, functional activity of patients' T lymphocytes was assessed in the mixed lymphocyte reaction (MLR). PWM-induced immunoglobulin secretion, of both IgG and IgM, was elevated in the first 2 to 3 weeks after burn, followed by a period of relatively suppressed antibody response at 3 to 4 weeks. Immunoglobulin production was then apparently restored to baseline or higher levels in surviving patients. However, in patients whose antibody response continued to be suppressed fatal septicemia developed. The background (spontaneous) immunoglobulin synthesis increased significantly over the normal range in 10/78 tests performed. These alterations in mitogen-induced immunoglobulin production were well correlated with changes in the T-cell alloreactivity in the MLR. Thus thermal injury-associated changes in the patients' humoral responses may be a consequence of changes within the T-cell compartment, especially the T-helper cell subset.

Adolescent↗
PubMed1986

Impairment of T cell activation in burn patients: a possible mechanism of thermal injury-induced immunosuppression.

In the burn patient, the mechanisms leading to impaired T lymphocyte activity are unclear. The capacity for T cell proliferation and the expression of Tac antigen (IL-2 receptor) was assessed during the post-burn period in patients with injuries ranging from 5-68% total body surface area. T cell-dependent (polyclonal) immunoglobulin synthesis, mixed lymphocyte reaction and Interleukin-2 production were also determined in these patients and correlated with survival. Surviving patients demonstrated a transient reduction while terminal patients exhibited a permanent reduction in the number of Tac (+) lymphocytes, unrelated to the absolute number of T cells, during the post-burn period. The reduced percentage of IL-2 receptor-expressing T cells coincided with the suppressed antibody response and reduced alloreactivity. Although the concentration of IL-2 was decreased in all patients throughout the hospitalization period, surviving patients showed a gradual increase in its production while terminal patients gradually decreased to undetectable levels. Exogenous recombinant IL-2 induced a significant enhancement of in-vitro polyclonal immunoglobulin production and blastogenesis in the mixed lymphocyte reaction in immunosuppressed patients who demonstrated up to 50% reduction in the percentage of IL-2 receptor positive cells. Thus, the reduced capacity for production of and response to IL-2 after thermal injury may lead to the immunosuppression due to a lack of T lymphocyte clonal expansion. The permanent nature of this defect in patients who died from fatal sepsis may suggest a causative relationship.

Adult↗
PubMed1985

Massive heterotopic ossification in breast implant capsules.

A patient is presented with massive heterotopic ossification of breast implant capsules, 17 years after surgical implantation of Silastic prostheses. The patient has been receiving oral calcium supplements for the past 3 years. This condition developed diffusely throughout the breast capsules. The capsules were 1.2 to 2.2 cm thick and demonstrated a layered structure. The calcified material was demonstrated radiologically and histologically to be true ossification.

Breast↗
PubMed1985

Massive soft-tissue chondroma of the hand.

A patient had a massive (8.5 X 6.0 X 3.0 cm) soft-tissue chondroma of the hand which developed over a 9-month period, producing pain, tenderness, and median nerve compression. This tumor was adherent to profundus tendons in the palm and to soft tissue in the carpal tunnel. The clinical presentation, microscopic findings, and behavior of chondromas are discussed.

Chondroma↗
PubMed1985

Fournier's gangrene.

Fournier's disease--gangrene of the penis and scrotum--is an uncommon condition. During the past 6 years, five patients, whose cases are described, were admitted to Toronto General Hospital with this diagnosis. Four had preceding trauma (ischiorectal abscess, puncture wound, surgery) and four had pre-existing debilitating problems (diabetes, rectal carcinoma, acute lymphocytic leukemia, alcoholic cirrhosis). Appropriate treatment must include urgent radical surgery to remove all necrotic tissue, and combination antibiotic therapy directed against the likely organisms, which are aerobic gram-negative rods, gram-positive cocci and anaerobes. Clindamycin in combination with tobramycin or gentamicin proved to be effective in this series.

Adult↗
PubMed1984

Alkali burns from wet cement.

When water is added to the dry materials of Portland cement calcium hydroxide is formed; the wet cement is caustic (with a pH as high as 12.9) and can produce third-degree alkali burns after 2 hours of contact. Unlike professional cement workers, amateurs are usually not aware of any danger and may stand or kneel in the cement for long periods. As illustrated in a case report, general physicians may recognize neither the seriousness of the injury in its early stages nor the significance of a history of prolonged contact with wet cement. All people working with cement should be warned about its dangers and advised to immediately wash and dry the skin if contact does occur.

Burns, Chemical↗
PubMed1984

A biphasic serum glucose response in mice to inoculation with pertussis vaccine.

The effect of B. pertussis vaccine on the serum glucose level of mice was investigated. The results show that at least two components in the vaccine interfere with glucose metabolism. A heat-stable component which is assumed to be LPS induced hypoglycemia 3-5.5 h after inoculation, especially in LPS-sensitized mice. A heat-labile component which is possibly equivalent with the LPF/HSF/IAP complex, is responsible for persistence of the hypoglycaemia for at least 6 days. If hypoglycaemia contributes to the neurological side effects after pertussis vaccination both components have to be considered as being responsible for these effects.

Animals↗