Intraluminal laser light source and external solder: in vivo evaluation of a new technique for microvascular anastomosis

BACKGROUND AND OBJECTIVES: Current laser-assisted end-to-end anastomoses are performed by irradiating the vessel wall from outside after additional fixation with three to six sutures. These sutures are needed to provide adequate approximation of the vessel stumps. We present a new laser soldering technique that is based on an intraluminal laser light source centered in a balloon catheter, and external application of a solder. This technique was applied in vivo in order to test its feasibility under clinical conditions. STUDY DESIGN/MATERIALS AND METHODS: Seven white pigs were treated with a total of fourteen end-to-end laser-anastomoses of their saphenous arteries having outer diameters of 2 mm. The vessels were stented over an intraluminal balloon catheter, which was maximally dilated and which allowed for a precise approximation of the vascular stumps. An 808 nm diode laser was coupled into a specially designed optical fiber producing a 360 degrees radiation ring inside the balloon catheter. An indocyanine green (ICG) doped liquid albumin solder was applied on the external surface of the vascular stumps. Laser soldering was achieved by irradiating with a 808 nm laser diode for 75 seconds. Tightness of the anastomoses was evaluated by clamping the artery distal to the anastomosis for 1 hour, and patency was tested over an observation period of 3 hours, during which the animals were heparinized. Thereafter, the anastomoses were harvested for histomorphological examination. RESULTS: All anastomoses remained patent over the entire observation period. Some leakage was observed in three anastomoses, which was explained by a deviation of the illumination fiber from the center of the balloon leading to an inhomogeneous irradiation of the vessel wall. Histology revealed perfect adaptation of the vascular stumps. A segment of denaturated vascular collagen was observed, that corresponded to the irradiated, solder-covered zone. CONCLUSION: Patent, maximally dilated and well adapted microvascular anastomoses could be obtained without the need of stay sutures. A well centered laser light source is indispensable for avoiding inhomogenous welding, thus causing leakage.     

Predictors of inotrope use during separation from cardiopulmonary bypass

OBJECTIVE: To identify the demographic, clinical, and echocardiographic features that predict the use of inotropic support at separation from cardiopulmonary bypass (CPB). Design: Retrospective study of consecutive patients undergoing coronary artery bypass graft (CABG) surgery. SETTING: Referral center for cardiothoracic surgery at a university hospital. PARTICIPANTS: One thousand nine patients undergoing either CABG or combined CABG and valve surgery with CPB in whom an intraoperative transesophageal echocardiography (TEE) examination was performed. INTERVENTIONS: Inotropic support was defined as the use of dopamine >/=5 microg/kg/min; any dose of epinephrine, norepinephrine, dobutamine, and milrinone; or the insertion of an IABP during separation from CPB. Support was implemented by the anesthesia care team as clinically indicated. Comprehensive TEE examinations were conducted before CPB in all patients according to published guidelines and subsequently reviewed by a single, independent operator. MEASUREMENTS and MAIN RESULTS: Inotropic support was used in a total of 394 patients (39%) at separation from CPB. The study identified 6 significant, independent predictors of inotrope use: (1) Wall Motion Score Index, (2) combined CABG and mitral valve repair or replacement surgery, (3) left ventricular ejection fraction <35%, (4) reoperation, (5) moderate-to-severe mitral regurgitation, and (6) aortic cross-clamp time. CONCLUSIONS: Incorporating data from a comprehensive intraoperative TEE examination, the authors identified 6 reproducible factors that independently predict the use of inotropic support at separation from CPB.     

Determination of cobalt in pharmaceutical products

The aim of this paper is to determine the content of cobalt in pharmaceutical products (B(12) vitamin powder, B(12) ampoules, Centrum, Spectrum ABC and Optima Forte) by spectrometric (FAAS, GFAAS and ICP-AES) and electrometric (AdSV) analytical techniques. The samples (approximately 0.5g) were treated with a mixture of 6mL HNO(3) and 1mL H(2)O(2) in the microwave oven. Due to the matrix effects the method of standard addition is preferred. The validity of the methods was tested by recovery studies of standard addition and results were found to be satisfactory.     

Risk factors for night vision complaints after LASIK for myopia

PURPOSE: To study the preoperative risk factors for night vision complaints (NVCs) after LASIK in a clinical setting. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Seven hundred ninety-five patients (1488 eyes) who underwent LASIK for myopia up to -9.75 diopters (D) (from January 1 to December 31, 1999). SETTING: Private clinic. METHODS: A complete preoperative examination was performed. Patients had bilateral LASIK surgery using the Nidek EC-5000 non-wavefront guided slit-scanning excimer laser and the Moria LSK One microkeratome. Patients were observed postoperatively for 12 months. MAIN OUTCOME MEASURES: The reported NVCs for each eye were rated on a subjective scale based on functional visual comfort. Clinically important NVC odds ratios (ORs) were calculated. RESULTS: Reports of NVCs decreased considerably from 25.6% at 1 month to 4.7% at 12 months postoperatively, at which time all patients reported similar NVCs in both eyes. Stratification of risk factors at 12 months postoperatively showed a 2.8-times increase in NVCs for initial myopia of >5 D, a 2.5-times increase for an optical zone of 相似文献   

CD40/CD40 ligand interactions in the host defense against disseminated Candida albicans infection: the role of macrophage-derived nitric oxide

CD40L interaction with CD40 is required for normal cellular immune responses such as T cell-mediated activation of monocytes/macrophages, proinflammatory cytokine production, and leukocyte extravasation. We investigated the role of CD40/CD40 ligand (L) interactions during disseminated candidiasis in CD40L knockout (CD40L-/-) mice. While early during infection there were no differences in the Candida albicans outgrowth in the organs of wild-type and knockout mice, the CD40L-/- mice had a significantly increased yeast load in the kidneys compared to CD40L+/+ mice late during infection. Similar effects were observed in CD40L+/+ mice in which CD40 ligation was blocked by a neutralizing anti-CD40 antibody. The peak TNF-alpha plasma concentrations were significantly lower in the CD40L-/- mice than in CD40L+/+ mice. C. albicans-stimulated production of nitric oxide (NO) by peritoneal macrophages from CD40L-/- in vitro was significantly lower than that of control mice, and this was responsible for a reduced candidacidal activity of CD40L-/- macrophages. The role of endogenous NO synthesis induced by CD40 ligation for the defense against disseminated candidiasis was further demonstrated by the absence of these effects in knockout mice deficient in inducible NO-synthase. In conclusion, absence of CD40/CD40L interactions results in increased susceptibility to disseminated infection with C. albicans through decreased NO-dependent killing of Candida by macrophages.     

Pulmonary alveolar proteinosis

It is a disease of obscure cause that is characterized by the accumulation of a granular material that contains abundant lipid within the alveoli of lung. Pulmonary alveolar proteinosis (PAP) has been divided into a congenital and an adult form. The acquired form has been subdivided into a idiopathic form and a secondary form associated with a know disorder or exposure as silica, aluminium, titanium. Dyspnea and cough are the most common presenting symptoms. Chest pain, hemoptysis, fever and weight loss are variably reported. Pathogenesis remains unknown, but evidence points to a dysfunction of alveolar macrophages. Mice genetically deficient in granulocyte macrophagecolony stimulating factor (GM-CSF) show an alveolar proteinosis. A neutralizing antibody against GM-CSF was found in bronchoalveolar lavage fluid and serum of patients with idiopathic PAP. Currently, no specific therapy exists for pulmonary alveolar proteinosis, and sequential whole lung lavage is standard treatment.     

Posttraumatic aniridia--clinical reports

The paper illustrates the case of a posttraumatic aniridia, following a domestic accident. The total desinsertion of the iris occurred after a contusive trauma associated with the rupture of the eye ball. The iris left the eye ball through the scleral rupture. The pigmentary impregnation of the conjunctiva in front of the scleral rupture suggests the possible intervention of a mechanism of autophlagia of the iris. The lens kept its normal position, but has became completely opaque. The traumatic aniridia has been associated with the devastating loss of vision, because of the associated vitreo/retinal lesions. The immediate and late postoperative aspects are illustrated.     

Novel anticoagulant activity of polyamino acid offsets bacterial endotoxin-induced extrinsic hypercoagulation: downregulation of monocytic tissue factor-dependent FVII activation

The extrinsic hypercoagulation often resulting from sepsis could contribute to disseminated intravascular coagulation and cardiovascular complications. The effective prevention and intervention remained largely complex and unclear. In a cell model of human leukemia THP-1 monocytes following bacterial endotoxin (LPS) exposure, we show the novel anticoagulant ability of polyamino acid (polyAA) to suppress the extrinsic hypercoagulation. LPS-induced monocytic tissue factor (mTF) procoagulation was readily offset by poly-L-lysine (PLK), poly-L-arginine (PLR), or poly-L-ornithine (POR) included in single-stage clotting assays. IC50 was estimated at 0.35, 0.30, or 0.58 microM for PLR, POR, or PLK, respectively, whereas, poly-L-asparatic acid (PLD) remained ineffective. In a separate approach, inclusion of cationic polyAA in human plasma significantly prolonged prothrombin time, confirming the depressed extrinsic coagulation. In chromogenic assays dissecting the extrinsic pathway, we further determined the inhibitory site(s). PLK, PLR, or POR significantly inhibited LPS-induced FVII activation, which was consistent with the diminished FVIIa formation shown on Western blotting analysis. In contrast, polyAA did not show any additional effect on either FVIIa/FXa amidolytic activities or mTF/FVIIa-catalyzed FX activation. Nor did polyAA show any effect on FVII activation directly catalyzed by FXa. Taken together, PLK, PLR, or POR preferentially inhibited mTF-dependent FVII activation, accounting for their novel anticoagulant activities. PolyAA might present the specific antagonists to arrest the extrinsic hypercoagulation following inflammation.