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A preliminary investigation has been performed (a) to determine the kinetics of bone ingrowth into porous materials and to determine if this ingrowth could be catalyzed by the presence of a foreign substrate; and (b) to measure the bonding capability of bone with a porous-surfaced metallic implant. Tests on porous-surfaced implants corroborate the work of other investigators in showing that bony tissue will grow into a porous substance that has pores large enough to support tissue nourishment. The shear strength of the bone-implant interface appears to increase with pore size and time of healing. Furthermore, it may be possible to catalyze this tissue ingrowth by the introduction into the fracture site of a foreign substance; in this experiment, glass beads 200-290mu in diameter were used.  相似文献   
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Fluorescein penetration into the posterior vitreous depends on plasma-free fluorescein concentration and blood-retinal barrier (BRB) permeability. The reproducibility of two methods of deriving BRB permeability was studied in 19 normal eyes of 14 subjects using vitreous fluorophotometry on two separate occasions. Plasma-free fluorescence was measured at intervals over 1 hr and posterior vitreous fluorescence was measured before (background scan), within 6 min (bolus) and at 60 min (measurement) after intravenous fluorescein (14 mg X kg-1). A computer algorithm subtracted background fluorescence from the measurement scan which was then corrected for signal spread by using a "spread" function derived from the bolus scan. BRB permeability coefficient and vitreous diffusion coefficients were derived by fitting a mathematical model to the plasma and corrected vitreous fluorescence data. A permeability index was also calculated by dividing the area under the vitreous fluorescence by the area under the plasma fluorescence curve. There were no significant differences in the results between right and left eyes. Mean +/- SD values on first and second occasions for all eyes were permeability coefficient: (1.91 +/- 0.94) and (2.08 +/- 0.95) X 10(-7) cm X s-1; diffusion coefficient: (1.33 +/- 0.68) and (1.19 +/- 0.54) X 10(-5) cm2 X s-1; and permeability index: (2.05 +/- 1.03) and (2.11 +/- 1.02) X 10(-7) cm X s-1.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Objective

Granulomatosis with polyangiitis (Wegener's) (GPA) is a systemic necrotizing vasculitis in which pulmonary nodules are a common manifestation. Our study examined whether pulmonary nodules, and nodule type (solid versus cavitary), are associated with different disease manifestations and outcomes.

Methods

Demographic, clinical, biologic, and radiologic data at diagnosis and during followup and treatments of GPA patients followed at the Mount Sinai Hospital (Canada) Vasculitis Clinic were analyzed. Patients were separated by the absence of lung nodules, presence of solid nodules only, and presence of cavitary nodules (+/? solid nodules). The study outcomes included followup lung imaging, relapses, and deaths.

Results

Of 225 patients with GPA, 46 had solid nodules only and 44 had cavitary nodules at diagnosis. Demographic and clinical manifestations were similar in the patient subgroups at diagnosis. Cyclophosphamide (CYC) was used for induction after diagnosis in 76.7% of patients with cavitary nodules, compared with 64.7% of patients without nodules and 51.1% of patients with solid nodules (P = 0.04). The mean ± SD followup after diagnosis was 106.6 ± 92.6 months, and 6 of the patients died. In multivariable analysis, diagnosis before 2000 or pulmonary nodule cavitation at diagnosis were associated with relapse, with a hazard ratio of 0.38 (95% confidence interval [95% CI] 0.22–0.65; P < 0.001) and 1.53 (95% CI 1.00–2.33; P = 0.05), respectively, after adjustment for CYC use.

Conclusion

The presence of cavitary nodules led to increased use of CYC but had no impact on survival. Relapse occurred more often, however, in patients with cavitary nodules than in those with solid nodules or no nodules, and should be studied in other cohorts.
  相似文献   
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Background

It is difficult to obtain adequate tissue sample for diagnosing autoimmune pancreatitis (AIP) with the help of traditional EUS-guided FNA. As per ICDC guidelines, EUS-guided FNA is not recommended for diagnosing AIP(1). We herein present a report of 2 cases of using a new flexible 22 gauge (G) core biopsy needle (SharkCore, Medtronic, Sunnydale, Calif) for diagnosing AIP.

Methods

This is a report of 2 cases reviewed retrospectively which had used 22G core biopsy needle for obtaining histo-pathological samples for diagnosing AIP. The cases were reviewed with both endoscopist and a pathologist to determine if the diagnostic criteria were met.

Results

Both the cases had adequate tissue sample obtained to make a clear diagnosis of AIP. Pathology showed changes of chronic pancreatitis with atrophy and storiform pattern of fibrosis with a dense lymphoplasmacytic infiltrate in both cases along with identification of IgG4 cells.

Conclusion

EUS-guided fine needle biopsy (FNB) using the SharkCore needle can be used reliably for diagnosing AIP. More studies need to be performed to validate this further.  相似文献   
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OBJECTIVERoux-en-Y gastric bypass (RYGB) characteristically enhances postprandial levels of glucagon-like peptide 1 (GLP-1), a mechanism that contributes to its profound glucose-lowering effects. This enhancement is thought to be triggered by bypass of food to the distal small intestine with higher densities of neuroendocrine L-cells. We hypothesized that if this is the predominant mechanism behind the enhanced secretion of GLP-1, a longer intestinal bypass would potentiate the postprandial peak in GLP-1, translating into higher insulin secretion and, thus, additional improvements in glucose tolerance. To investigate this, we conducted a mechanistic study comparing two variants of RYGB that differ in the length of intestinal bypass.RESEARCH DESIGN AND METHODSA total of 53 patients with type 2 diabetes (T2D) and obesity were randomized to either standard limb RYGB (50-cm biliopancreatic limb) or long limb RYGB (150-cm biliopancreatic limb). They underwent measurements of GLP-1 and insulin secretion following a mixed meal and insulin sensitivity using euglycemic hyperinsulinemic clamps at baseline and 2 weeks and at 20% weight loss after surgery.RESULTSBoth groups exhibited enhancement in postprandial GLP-1 secretion and improvements in glycemia compared with baseline. There were no significant differences in postprandial peak concentrations of GLP-1, time to peak, insulin secretion, and insulin sensitivity.CONCLUSIONSThe findings of this study demonstrate that lengthening of the intestinal bypass in RYGB does not affect GLP-1 secretion. Thus, the characteristic enhancement of GLP-1 response after RYGB might not depend on delivery of nutrients to more distal intestinal segments.  相似文献   
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