Evaluation of emergency tourniquets for prehospital use in China

Objective: Massive hemorrhage is lifethreatening during armed conflicts. Tourniquets are important medical devices used to reduce severe bleeding in trauma. The aim of this study was to empirically evaluate the current tourniquets used in China and provide information to emergency nurses in selecting the appropriate tourniquet.Methods: Five tourniquets were self-applied by 20healthy participants. The blood flow distal to the tourniquet site was assessed using vascular Doppler ultrasound.Application time, pain, numbness, and other parameters were evaluated.Results: The bladder tourniquet and windlass tourniquet effectively occluded arterial blood flow with success rates higher than 75% in both the upper and lower extremities. The Cargo-strap was the fastest to apply, taking (7.22±2.30) s for the upper extremity and (6.48±2.40) s for the lower extremity. The rubber tube was the most painful, and the improvised tourniquet was the least efficient. The success rates were higher in the lower extremity than in the upper extremity (P＜0.05, X2=5.714).Conclusions: The bladder tourniquet and the windlass tourniquet are efficient tourniquets, although the windlass is superior with respect to portability and pain. The Cargo-strap and rubber tourniquets have several disadvantages that reduce their suitability for field use. The improvised tourniquet is not recommended because of low efficiency and severe pain during implementation.     

Vineberg's procedure modified technique: flow analysis, immediate postoperative results and angiographic evaluation

BACKGROUND: The purpose of this study was to evaluate angiographic results of patients subjected to a technique variation of Vineberg's procedure, as well as their morbidity and mortality in immediate postoperative period, and to analyze the flow of grafted left internal thoracic artery (LITA) at rest and under stress. METHODS: Between September 1999 and April 2002 eight patients were operated upon, with implant of the internal thoracic artery (ITA) in the intimal layer of the left ventricle (LV) muscle. After 6 months, they underwent angiographic and Doppler evaluation. According to Doppler study of LITA, the sample was divided in two groups: "Vineberg group," formed by eight patients; and "control group" consisting of 20 patients whose LITA directly revascularize the anterior interventricular artery (AIV). Angiography showed patency of all grafts in both groups. Blood flow and flow velocity in grafts were measured by Doppler echocardiography. T-test for paired and unpaired samples were used for statistical analysis. RESULTS: There were no deaths or complications in immediate postoperative period. Angiography showed 100% patency. The total flow (TF) of Vineberg group was 55% of the flow in the control group. In both groups, the TF increased with the stress. CONCLUSIONS: This Vineberg's technique modification can be successfully used in patients who cannot undergo traditional direct revascularization due to its low rates of morbidity and mortality and a high rate of patency, providing a significant blood flow both at rest and under stress.     

Practical aspects of the use of target controlled infusion with remifentanil in neurosurgical patients: predicted cerebral concentrations at intubation, incision and extubation

Remifentanil has important side effects and it is not easy to know what remifentanil concentrations should be used during different endpoints of anaesthesia. We analyzed the remifentanil predicted effect-site concentrations (RemiCe) at different events during neurosurgical procedures and assessed if the concentrations used were clinically adequate. BIS and haemodynamic parameters were collected every 5 seconds. Predicted cerebral concentration of propofol (PropCe) and RemiCe were analyzed immediately prior to respective stimulus, and 30, 60 and 90 seconds after. RemiCe were 2.2 +/- 0.3, 6 +/- 2.6 and 2.2 +/- 0.9 ng ml(-1) at intubation, incision and extubation, respectively. PropCe observed in the same periods were 5 +/- 1, 2.6 +/- 0.9 and 1 +/- 0.3 microg ml(-1), also respectively. The remifentanil concentrations used in our patients were lower than reported concentrations, while being clinically adequate to minimize the haemodynamic response to stimulation.     

A Bacteroides fragilis surface glycoprotein mediates the interaction between the bacterium and the extracellular matrix component laminin-1

The adherence of Bacteroides fragilis strains to immobilized laminin-1 (LMN-1) was investigated using this protein adsorbed onto glass. Among the 27 strains isolated from infectious processes and assayed, 13 presented strong adherence to LMN-1. Among them, two strains, MC2 and 1081, showed the strongest association, and for that reason they were selected for further studies in which adherence to this protein was confronted with both physical-chemical and enzymatic treatments, along with concurrence assays with the LMN-1 molecule itself and the LMN-1-residing amino acid sequences (RGD, IKVAV, YIGSR, AG73, A13 and C16). The chemical and enzymatic treatments resulted in sharp decreases in binding rates of those strains, and competition experiments with LMN-1- residing amino acids revealed that, except for RGD and A13, all the others were effective at reducing bacterial binding of the bacteria. The outer membrane proteins (OMPs) of B. fragilis were extracted and assayed onto dot-blotted LMN-1, and when the extracts were chemically treated, especially with metasodium periodate, a drastic reduction in bacterial binding occurred. Results of the latter assays clearly indicate that bacterial molecules involved in both recognition and binding of B. fragilis to LMN-1 are present in OMP extracts. Taken together, our results strongly indicate that a B. fragilis surface glycoprotein may play a key role in bacterial association with LMN-1.     

Accessibility to residues in transmembrane segment four of the glycine receptor

Glycine receptors (GlyRs) are members of the ligand-gated ion channel superfamily. Each subunit has four transmembrane segments (TM1-TM4). Several studies suggest that amino acids in all four TMs face into a water-filled, alcohol and anesthetic binding cavity in the extracellular portion of the transmembrane domain. TM4 should contribute a "wall" to this cavity, but the residues involved are unknown. Here, we determined the ability of an alcohol analog, propyl methanethiosulfonate (propyl MTS), to covalently react with twelve GlyR TM4 positions (I401-I412) after mutating the original amino acids to cysteines. Reactivity of a cysteine with propyl MTS implies that the cysteine is exposed to water. W407C, I409C, Y410C, and K411C showed altered receptor function following reaction with propyl MTS in the presence or absence of glycine. The cysteine mutations alone eliminated the effects of ethanol for I409C, Y410C, and K411C, and reduced the effects of octanol for I409C and isoflurane for K411C. The ability of propyl MTS to reduce isoflurane and chloroform potentiation was examined in the reactive mutants. Potentiation by isoflurane was significantly reduced for I409C after reaction. These data demonstrate water-accessibility of specific TM4 positions in the GlyR and suggest involvement of these residues with alcohol and anesthetic action.     

Onset of abnormal blood and lymphatic vessel function and interstitial hypertension in early stages of carcinogenesis

Recent improvements in diagnostic methods have opened avenues for detection and treatment of (pre)malignant lesions at early stages. However, due to the lack of spontaneous tumor models that both mimic human carcinogenesis and allow direct optical imaging of the vasculature, little is known about the function of blood and lymphatic vessels during the early stages of cancer development. Here, we used a spontaneous carcinogenesis model in the skin of DNA polymerase eta-deficient mice and found that interstitial fluid pressure was already elevated in the hyperplastic/dysplastic stage. This was accompanied by angiogenic blood vasculature that exhibited altered permeability, vessel compression, and decreased alpha-smooth muscle actin-positive perivascular cell coverage. In addition, the lymphatic vessels in hyperplastic/dysplastic lesions were partly compressed and nonfunctional. These novel insights may aid early detection and treatment strategies for cancer.