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A mechanical computerized three-dimensional scanner with a resolution of 1 micron was used to assess loss of enamel caused by orthodontic bonding and debonding. A total of 2646 measurements was performed on six human premolars. The results showed an average loss of enamel of 7.4 microns. The range was between 1 and 52 microns, which may account for discrepancies with earlier studies that measured only a few points per tooth surface.  相似文献   

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Haemodialysis access graft infection is easily recognizable when local symptoms (warmth, swelling, pain, or drainage) predominate, and endocarditis is a well established complication of infected grafts. We report a case of bacterial endocarditis complicating silent infection in clotted haemodialysis access graft. It is suggested that, clotted non-functioning grafts may be the harbingers of silent infection, and should be suspected as the source of infection in every haemodialysis patient that presents with fever, even in the absence of clinical signs of graft site infection.  相似文献   

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The activation energy (Ea) of beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52) was determined with 3,3'-dichlorophenylsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide as substrate, with a much higher value being found for the Hex B isoenzyme (Ea = 75.1 kJ/mol) than for the Hex A isoenzyme (Ea = 41.8 kJ/mol). This fact allowed for the development of a fast and reliable thermodynamic method to determine the isoenzyme composition of Hex in different biological specimens (serum/plasma, saliva, cerebrospinal fluid, seminal plasma, urine, and leukocyte lysates). The results in serum given by the proposed method may be superimposed upon those obtained by the heat inactivation assay of O'Brien et al. (N Engl J Med 1970;273:15-20), and the catalytic activity calculated for Hex A offers a good correlation with that obtained by using the specific substrate 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide-6 sulfate (n = 25, r = 0.953).  相似文献   

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This is case report concerning secondary caustic sclerosing cholangitis following scolecide with concentrated sodium chloride solution (30%) during operation on a liver echinococcus cyst with involvement of the extrahepatic biliary apparatus only. Hepatojejunostomy is performed. Histological study of the liver demonstrates evidence of severe cholangitis, purulent cholangiolitis and suspected secondary biliary cirrhosis. In conclusion, it is stressed that dynamic postoperative follow-up of patients is mandatory to make early diagnosis of the complication and undertake operative treatment anticipating the development of a cirrhotic process. The search for new, effective scolicides, not damaging the biliary apparatus and hepatic parenchyma, is strongly recommended.  相似文献   

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Widespread recognition is given to the idea that an individual's health is influenced by the ways an individual works, rests and plays as well as genetic endowments. More recently, some researchers have suggested that the relationships between individual 'characteristics' and health are influenced by the context or community of the individual. Although the notion of the community as a determinant of health is not new, the incorporation of the community in empirical research on the determinants of health has been based on simple statistical models that fail to reflect the complex nature of the individual-community interface. In this paper we use the methods developed in educational research to show how separate statistical models for variations in health between communities and between individuals can be combined to provide a multi-level model for the determinants of health of populations.  相似文献   

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Continuing investigations of vascular graft materials suggest that unacceptable graft complications continue and that the ideal graft material has not yet been found. We have developed and tested a biologic vascular graft material, small intestine submucosa (SIS), in normal dogs. This material, when used as an autograft, allograft, or xenograft has demonstrated biocompatibility and high patency rates in aorta, carotid and femoral arteries, and superior vena cava locations. The grafts are completely endothelialized at 28 days post-implantation. At 90 days, the grafts are histologically similar to normal arteries and veins and contain a smooth muscle media and a dense fibrous connective tissue adventitia. Follow-up periods of up to 5 years found no evidence of infection, intimal hyperplasia, or aneurysmal dilation. One infection-challenge study suggested that SIS may be infection resistant, possibly because of early capillary penetration of the SIS (2 to 4 days after implantation) and delivery of body defenses to the local site. We conclude that SIS is a suitable blood interface material and is worthy of continued investigation. It may serve as a structural framework for the application of tissue engineering technologies in the development of the elusive ideal vascular graft material.  相似文献   

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Unexpected intraoperative vascular complications in the graft of the recipient during organ transplantation can be most vexing and require immediate attention and careful management so as not to impair the integrity and fate of the graft. We were confronted with a diabetic recipient with total fibrosis of the left iliac vein, patent inferior vena cava, totally and circumferentially calcified aorta and left iliac artery with the exception of a small area in the distal external iliac artery. The problem was solved by anastomosing the artery low onto the external iliac, and by interposing a venous polytetrafluoroethylene vascular graft between the renal vein and the inferior vena cava. The kidney function was excellent for 2 years but the patient succumbed to unrelated liver complications. A second patient with a renal vein PTFE graft has had normal graft function for 10 years. Probably because of the high blood flow through the kidney, venous synthetic grafts can be successfully used to correct venous problems during kidney transplantation.  相似文献   

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The mosquitos collected in Smolensk and Kaluga provinces in 1985 by the expedition team of the D. I. Ivanovski? Institute of Virology were identified by V. N. Danilov in 1986. Among the females of mosquitos collected in Smolensk Province four genera and 16 species were recorded; two genera (Culiseta, Mansonia) and 9 species were new ones for this region. Taking in account the reference data (excluding Anopheles hircanus and Aedes behningi, the presence of which here is doubtful) there 22 species of mosquitos of five genera (Anopheles--3, Aedes--16, Mansonia, Culiseta, Culex--one of each) are recently known in Smolensk Province. Among the females of mosquitos collected in Kaluga Province, two genera and 8 species were found including one genus (Mansonia) and three species being a new ones for this region. Together with the reference data, there 17 species of mosquitos of four genera (Anopheles--2, Aedes--13, Mansonia, Culex--one of each) are known now for Kaluga Province.  相似文献   

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Development of a small diameter (4 mm inner diameter [ID]) prosthetic vascular graft with functional groups accessible for covalent binding of recombinant hirudin (a potent anticoagulant) should create a more hemocompatible surface. The purpose of this study was to develop a technique for generating carboxylic acid groups on the surface of precast 4 mm ID poly-(carbonate urea)-urethane vascular grafts and to evaluate the accessibility of these groups. A polycarbonate based urethane with the chain extender 2,2-bis(hydroxymethyl)propionic acid was synthesized. A precast 4 mm ID poly(carbonate urea)-urethane vascular graft (Chronoflex [CF]; CardioTech International, Woburn, MA) was then placed into a 4% carboxylated polyurethane (cPU) solution (in 1% dimethyl acetamide) and incubated for 30 minutes (cPU graft). To determine the accessibility of the carboxylic acid groups, a standard textile technique using methylene blue dye was used. Macroscopic cross-sections, which were cut and evaluated for dye penetration, showed greatest concentration of carboxylic acid groups at the luminal and capsule surfaces, with minimal penetration into the mid-portion of the graft. Analysis of dye baths for absorbance reduction resulted in the cPU grafts having 3.7-fold and 5.4-fold more accessible carboxylic acid groups compared with untreated and dimethyl acetamide dipped CF grafts. Thus, a novel small diameter vascular graft has been developed that contains reactive carboxylic acid groups accessible for protein binding.  相似文献   

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Cosmetic facial surgery can improve appearance but it cannot make everyone beautiful (or handsome) or solve all problems. The patient must be well motivated and must comprehend the limitations of the procedures. Procedures useful in providing a more youthful appearance include blepharoplasty, browlift and face-lift. Sometimes all three are indicated. Chemical face peeling is used for correction of fine skin lines.  相似文献   

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Debate continues over which procedure is the best treatment for prosthetic graft infections. We retrospectively reviewed the medical records at our institution for all vascular graft infections that occurred from 1985 to 1995 to evaluate their occurrence, treatment, and outcome. Twenty-four patients had prosthetic graft infections. The average patient age was 62 years, and 67 per cent of the patients studied were men. The initial operation was for treatment of occlusive disease in 92 per cent of the patients, and aortofemoral bypasses were the most common procedures performed (15 of 24 patients, 63%). The average interval from graft implantation to presentation of infection was 29 months. In lower-extremity bypasses, the site of infection was most commonly in the groin (87%). Gram-positive organisms, including coagulase-negative Staphylococcus (32%) and Staphylococcus aureus (28%), were the most frequently isolated bacteria. Thirty procedures were performed for management of the graft infections. Extra-anatomic bypass was associated with no recurrent graft infections. Graft preservation was successful in two cases of early S. aureus infection (less than 1 year after original procedure), and in situ graft replacement was successful in all four cases of late-appearing coagulase-negative Staphylococcus infection (more than 1 year after original procedure). Both treatments failed in all five cases of Gram-negative infection (P = 0.008 by Fisher's exact test). The overall mortality and amputation rates were 17 per cent and 21 per cent, respectively, without significant differences between the treatment modalities. Extra-anatomic bypass remains the best treatment for prosthetic graft infection. In situ replacement and graft preservation treatments should be selective and based on presentation of the infection and the type of pathogenic organism.  相似文献   

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Discusses issues that arise in therapy when a patient has a miscarriage and the associated reactions and normal stages of mourning. The use of transference and the interpretation of the patient's psychodynamics are described and illustrated with clinical vignettes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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