Implementation of an image-guided radiation therapy program: Lessons learnt and future challenges

The aim of this paper is to detail the experience obtained in implementing an image-guided radiation therapy program at the Northern Sydney Cancer Centre. This required retrofitting a Varian Clinac 21EX with an on-board imager. The commissioning and quality assurance procedures, organisation of a multidisciplinary image guided radiation therapy group, and the development of clinical protocols for orthogonal kV and cone beam computed tomography implementation are described. Reassessment of the image-guided radiation therapy program has continued as new equipment and software versions were made available in the department.     

水体中克雷伯菌属的分布及其在水源性急性肠道感染中的价值

俄罗斯不同气候地区不同功能水体中克雷伯菌属广泛分布。克雷伯菌属可见于遭受生物、化学污染的集中供水的地表水源,无防护的地下蓄水层,缺乏有效清洁、消毒系统的饮用水。研究表明,水体中的克雷伯菌属具有致病性和毒性,对现代药物和消毒剂(氯、紫外线)具有抗性,很容易穿透进入地下蓄水层。克雷伯菌属细菌有很强的致病性(粘附力、侵袭力、磷酸酯酶、卵磷脂酶、脱氧核糖核酸酶、溶血活性),含有致病性遗传标记cnf-1。克雷伯菌属(100 CFU/dm³)可引起急性肠道感染。在不检测总大肠菌群的情况下,检测水体尤其是饮用水中的克雷伯菌属,可以评估所用水的流行病学危险。     

Proteoglycans in human long-term bone marrow cultures: biochemical and ultrastructural analyses

Proteoglycans within the extracellular matrix of human bone marrow have been implicated in the process of hematopoiesis, but little is known about the structure and composition of these macromolecules in this tissue. Hematopoietically active human long-term bone marrow cultures were incubated with medium containing 35S-sulfate and 3H-glucosamine as labeling precursors. Proteoglycans present in the medium and cell layer were extracted with 4 mol/L guanidine HCI and purified by diethylaminoethyl (DEAE)-Sephacel ion exchange and molecular sieve chromatography. Both culture compartments contain a large chondroitin sulfate proteoglycan (MI, CI) that eluted in the void volume of a Sepharose CL-4B column and contained glycosaminoglycan chains of molecular weight (mol wt) approximately 38,000. A second population of sulfate-labeled material was identified as a broad heterogenous peak (MII, CII) that was included on Sepharose CL-4B at Kav = 0.31. This material when chromatographed on Sepharose CL-6B could be further separated into a void peak (MIIa, CIIa) and an included peak eluting at Kav = 0.39 (MIIb, CIIb). The void peaks (MIIa, CIIa) were susceptible to chondroitinase ABC digestion (99%) but slightly less susceptible to chondroitinase AC digestion (90%). Papain digestion of these peaks revealed them to be proteoglycans with glycosaminoglycan chains of mol wt approximately 38,000. The included peaks on Sepharose CL-6B (MIIb, CIIb) from both medium and cell layer compartments resisted digestion with papain, indicating the presence of glycosaminoglycan chains of mol wt approximately 38,000 either free or attached to a small peptide. Although this material was susceptible to chondroitinase ABC (98%), it was considerably less susceptible to chondrotinase AC (approximately 60%), indicating that it contained dermatan sulfate. A small amount of heparan sulfate proteoglycan was also identified but constituted only approximately 10% of the total sulfated proteoglycan extracted from these cultures. Additionally, approximately 40% of the incorporated 3H- activity radioactivity was present as hyaluronic acid. Electron microscopy revealed a layer of adherent cells covered by a mat containing ruthenium red-positive granules that were connected by thin filaments. The extracellular matrix layer above the adherent cells contained a mixture of hematopoietic cells. Chondroitinase ABC treatment of the cultures completely removed the ruthenium red-positive granules overlying the cells and resulted in a loss of approximately 70% of the 35S-sulfate-labeled material from the cell layer.(ABSTRACT TRUNCATED AT 400 WORDS)     

Blood cell dynamics in P-selectin-deficient mice

P-selectin is expressed on the surfaces of activated platelets and endothelium where it mediates binding to leukocytes. P-selectin- deficient mice were shown to exhibit peripheral neutrophilia (Mayadas et al: Cell 74:541, 1993). We now show that this is not caused by changes in bone marrow precursors nor by a lack of neutrophil margination. Both P-selectin-positive and -negative animals displayed similar increases in peripheral blood neutrophil numbers after injection of epinephrine. However, clearance of 51Chromium-labeled neutrophils is delayed in mice deficient for P-selectin, indicating that the neutrophilia is at least in part the result of delayed removal. We detected no obvious alterations in lymphocyte differentiation, distribution, or adhesion to high endothelial venules in peripheral lymph nodes. Through intravital microscopy, we examined the impact of P-selectin deficiency on leukocyte/endothelial interaction beyond the initial stages of inflammation. Four hours after the administration of an inflammatory irritant, leukocyte rolling was observed even in the absence of P-selectin. There were significantly fewer rolling cells relative to wild-type mice, and their velocity was reduced. Moreover, in the peritonitis model, the number of peritoneal macrophages in wild-type mice increased threefold at 48 hours, whereas the macrophages in the mutant mice remained near baseline levels. Thus, whereas P-selectin is known to be involved in early stages of an inflammatory response, our results indicate that it is additionally responsible for leukocyte rolling and macrophage recruitment in more prolonged tissue injury.     

Cannula site insertion technique prevents incisional hernia in laparoscopic fundoplication

INTRODUCTION: Incisional hernia is a common surgical problem encountered after laparotomies. The so-called trocar-site or port-site hernia is a type of incisional one that occurs after laparoscopic procedures. It has an incidence range between 0.1% and 3%. OBJECTIVE: To evaluate our patients who underwent laparoscopic Nissen fundoplication for presence of trocar-site hernia. PATIENTS AND METHODS: This study included 405 patients who underwent laparoscopic Nissen fundoplication in Ankara University, Faculty of Medicine, Department of General Surgery, Turkey. The patients were evaluated by physical examination and anterior abdominal wall ultrasound (US). RESULTS: Trocar-site hernia was not detected in any of our cases either by physical examination or by US. CONCLUSIONS: Trocar-site hernia is a rare complication of laparoscopy. It occurs at the trocar insertion site with a diameter of 10 mm or more in adult patients. Trocar insertion away from the midline can decline the incidence.     

Risk factors for treatment failure in patients with ventilator-associated pneumonia receiving appropriate antibiotic therapy

PURPOSE: The aim of this study was to investigate modifiable risk factors and predictors for treatment failure (TF) in patients with ventilator-associated pneumonia (VAP) receiving appropriate antibiotic therapy. MATERIALS AND METHODS: An observational cohort study performed in an intensive care unit (ICU) of a University hospital. Eighty-nine patients with VAP were enrolled in the study consecutively. Treatment failure was defined as lack of clinical and microbiological response to therapy within 2 weeks. Potential risk factors for TF, related with patients, microorganisms, and ICU therapies, were evaluated. RESULTS: Mean age was 72 +/- 13 years. Fifty-three of the patients had TF. Patients with TF were older, had more comorbidities, higher admission and Acute Physiology and Chronic Health Evaluation Score (APACHE II)-VAP scores, lower daily carbohydrate intake, and lymphocyte number below 1000/mm(3) than the treatment success group. Transfusions, bacteremia, infection with multidrug-resistant microorganisms, initial bacterial load (CFU/mL), and steroid therapy were similar across the groups. Comorbidity (odds ratio [OR], 4.4; 95% CI, 1.2-16.8; P = .030), VAP-APACHE II scores above 16 (OR, 6.4; 95% CI, 2.1-18.6; P = .001), daily carbohydrate intake below 190 g/d (OR, 3; 95% CI,1.1-8.6; P = .038), lymphocyte number below 1000/mm3 (OR, 4.1; 95% CI, 1.3-12.9; P = .014) were independent predictors for TF. CONCLUSIONS: Patients with comorbidities, who are severely ill and lymphocytopenic at the time of VAP diagnosis, are at high risk for TF.