Emergency thoracic surgery for penetrating, non-mediastinal trauma.

BACKGROUND: Penetrating thoracic injury is commonly found in South Africa. A review of our recent experience was undertaken to assess the effectiveness of our protocols for this type of injury. METHODS: A retrospective study of 61 consecutive patients with penetrating, non-mediastinal trauma to the chest was conducted over 32 months at a single trauma unit. Patient details, mechanism of injury, operative procedure and in-hospital mortality and morbidity rates were recorded. RESULTS: Two thousand and nineteen patients presented with penetrating chest injury of which 61 patients (3%) underwent thoracic surgery for non-mediastinal injury. Twenty-six patients had stab wounds and 35 had gunshot wounds. Overall mortality was 17/61 (28%). Gunshot wounds were more likely to result in death than stab wounds (relative risk = 11.9; 95% confidence interval 1.7-84.0) and thoracoabdominal injury resulted in death more commonly than chest injury (relative risk = 4.8; 95% confidence interval 2.2-10.3) resulted in death. CONCLUSION: Penetrating chest injury is common and most patients can be managed without formal thoracic surgical intervention. However, the patients who do merit surgical intervention have a relatively high mortality and a rapid and practised operative approach is required to achieve acceptable results.

Improved Muscle Mitochondrial Capacity Following Gastric Bypass Surgery in Obese Subjects.

BACKGROUND: Weight loss resulting from low-calorie diets is often less than expected. We hypothesized that energy restriction would influence proton leakage and improve mitochondrial efficiency, leading to reduced energy expenditure, partly explaining the difficulties in weight loss maintenance. METHODS: Eleven women with a median BMI of 38.5 kg/m(2) (q-range 37-40), and referred to gastric bypass surgery participated. Before surgery, and at 6 months of follow-up, muscle biopsies were collected from the vastus lateralis muscle. Mitochondria were isolated and analyzed for coupled (state 3) and uncoupled (state 4) respiration and mitochondrial capacity (P/O ratio). RESULTS: At follow-up, the participants had a median BMI of 29.6 kg/m(2) (28.3-32.0). State 3 increased from 20.6 (17.9-28.9) to 34.9 nmol O2/min/U citrate synthase (CS) (27.0-49.0), p = 0.01, while state 4 increased from 2.8 (1.8-4.2) to 4.2 nmol O2/min/U CS (3.1-6.1), although not statistically significant. The P/O ratio increased from 2.7 (2.5-2.8) to 3.2 (3.0-3.4), p = 0.02, indicating improved mitochondrial efficiency. CONCLUSIONS: Six months after gastric bypass surgery, the mitochondrial capacity for coupled, i.e., ATP-generating, respiration increased, and the P/O ratio improved. Uncoupled respiration was not enhanced to the same extent. This could partly explain the decreased basal metabolism and the reduced inclination for weight loss during energy restriction.

Cyclooxygenase-2 and Bcl-2 expression in the stomach mucosa of Wistar rats exposed to Helicobacter pylori, N'-methyl- N'-nitro- N-nitrosoguanidine and bile.

Cyclooxygenase-2 (COX-2) and Bcl-2 have been implicated in upper gastrointestinal tract carcinomas, but the underlying mechanisms are not known. In the present study we assessed the correlation of COX-2 and Bcl-2 to known cell kinetics in the glandular stomach mucosa of 104 Wistar rats given combinations of Helicobacter pylori, MNNG ( N'-methyl- N'-nitro- N-nitrosoguanidine) and bile. COX-2 expression, Bcl-2 and cell proliferation (Ki-67) in antral and corpus mucosa were determined immunohistochemically. Apoptotic cells were detected using terminal uridine deoxynucleotidyl nick end labelling technique. Expression of COX-2 was found in the lower portion of glandular corpus epithelium, and Bcl-2 positivity was mainly seen in the proliferative zone of both antrum and corpus mucosa. COX-2 expression in histologically normal-appearing corpus mucosa was associated with cell proliferation, atrophy and intestinal metaplasia in antrum and with Bcl-2 expression in corpus mucosa. No correlation was found between apoptosis and Bcl-2 expression. MNNG but not H. pylori significantly increased COX-2 in corpus mucosa. H. pylori, however, promoted the COX-2 expression in corpus when bile was added and Bcl-2 expression in antrum. Abnormal expression of both COX-2 and Bcl-2 seem to be involved in H. pylori-induced gastric carcinogenesis by altering the gastric cell kinetics.

Reduced respiratory capacity in muscle mitochondria of obese subjects.

BACKGROUND/AIMS: The extent of weight gain varies among individuals despite equal calorie overconsumption. Furthermore, weight gain is often less than expected from energy excess. This suggests differences in metabolic efficiency and basal metabolism. Since mitochondrial uncoupling accounts for a substantial portion of the basal metabolic rate, we compared skeletal muscle mitochondrial respiration in obese subjects to normal-weight reference groups with various degrees of physical activity. METHODS: Muscle biopsies were taken from the vastus lateralis muscle of 9 healthy obese subjects (BMI 40 ± 3). Mitochondria were isolated and analyzed for coupled (state 3) and uncoupled (state 4) respirations as well as mitochondrial efficiency (P/O ratio) using pyruvate as a substrate. Respiratory data were compared to reference groups A, normal-weight untrained (BMI 24 ± 0.7), and B, normal-weight trained (BMI 24 ± 0.6). RESULTS: Obese subjects had a decreased respiratory capacity per mitochondrial volume compared to the reference groups: this was evident in state 4 (65% and 35% of reference group A and B, respectively) and state 3 (53% and 29% of A and B, respectively) (p < 0.05). CONCLUSION: Obese subjects had a low capacity for fuel oxidation, which may play a role in the predisposition of obesity. However, whether lower mitochondrial capacity is a cause or a consequence of obesity requires further research.

Penetrating cardiac injuries: recent experience in South Africa.

BACKGROUND: Penetrating cardiac injury is a dramatic and lethal form of trauma. The majority of patients will die before reaching medical care, but for those who arrive at hospital alive, the diagnostic acumen and rapid surgical intervention of physicians and surgeons can lead to successful outcomes. MATERIALS AND METHODS: A structured diagnostic and management approach is used in our trauma unit to deal with penetrating cardiac injury. A retrospective study of 117 patients with penetrating trauma to the heart was conducted over 32 months; the purpose of this study was to describe our protocol and review overall outcome with this type of injury. Demographic details, mechanism of injury, and mode of presentation were recorded. Mortality and morbidity data were collated and echocardiographic follow-up was performed. RESULTS: There were 109 male patients, mean age 29 years (range: 15-54 years) and 8 female patients, mean age 35 years (range: 23-56 years). Most patients (96/117) had sustained stab wounds, and the associated mortality was 15.6%. Twenty-one patients had sustained gunshot wounds (GSW), with a mortality of 81%. Gunshot wounds were significantly more likely to result in death (P