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71.
B lymphoblastoid cell lines with normal and defective O-glycosylation established from an individual with blood group Tn 总被引:2,自引:0,他引:2
Individuals with the Tn blood group contain terminal serine/threonine- linked N-acetylgalactosamine residues in their blood cells. This is due to lack of UDP-D-galactose: D-N-acetyl galactosamine beta-D-galactosyl transferase from part of their red cells and probably from their leukocytes. We have established B lymphoblastoid cell lines from such an individual by in vitro infection of his lymphocytes with Epstein- Barr virus. The original line contained a mixture of cells reactive and nonreactive with Helix pomatia lectin (Hp). These cells were subcloned after staining with fluorescent Hp by a fluorescence-activated cell sorter (FACS) into homogeneous, phenotypically stable lines of Hp- positive (Hp+) and Hp-negative (Hp-) cells. The molecular differences between the membrane glycoproteins were characterized by carbohydrate- specific surface labeling techniques, Hp affinity chromatography, polyacrylamide slab gel electrophoresis and glycopeptide/oligosaccharide analysis. The major O-glycosidic membrane glycoprotein (GP105) was retained on Hp-Sepharose columns only from Hp+ cells, whereas the common leukocyte antigen (GP160-200) was partially retained on Hp columns from both lines. These proteins were isolated by immune precipitation with monoclonal antibodies and characterized. The results show that the GP105 glycoprotein from Hp+ cells contains terminal N-acetylgalactosamine residues but also more complex oligosaccharides. The common leukocyte antigen showed different electrophoretic mobilities in Hp+ and Hp- cells. UDP-galactose D-N- acetyl galactosamine beta-galactosyl transferase was almost absent in the Hp+ cells. These cell lines are useful for studies on the functional role and regulation of the biosynthesis of O-glycosidic carbohydrates. 相似文献
72.
73.
Zi Zhang James Lovato Harsha Battapady Christos Davatzikos Hertzel C. Gerstein Faramarz Ismail-Beigi Lenore J. Launer Anne Murray Zubin Punthakee Amilcar A. Tirado Jeff Williamson R. Nick Bryan Michael E. Miller 《Diabetes care》2014,37(12):3279-3285
OBJECTIVEThe effect of hypoglycemia related to treatment of type 2 diabetes mellitus (T2DM) on brain structure remains unclear. We aimed to assess whether symptomatic severe hypoglycemia is associated with brain atrophy and/or white matter abnormalities.RESULTSOf the 503 T2DM participants (mean age, 62 years) with successful baseline and 40-month brain MRI, 28 had at least one HA episode during the 40-month follow-up. Compared with participants without HA, those with HA had marginally significant less atrophy (less decrease in TBV) from baseline to 40 months (−9.55 [95% CI −15.21, −3.90] vs. −15.38 [95% CI −16.64, −14.12], P = 0.051), and no significant increase of AWM volume (2.06 [95% CI 1.71, 2.49] vs. 1.84 [95% CI 1.76, 1.91], P = 0.247). In addition, no unexpected local signal changes or volume loss were seen on hypoglycemic participants’ brain MRI scans.CONCLUSIONSOur study suggests that hypoglycemia related to T2DM treatment may not accentuate brain pathology, specifically brain atrophy or white matter abnormalities. 相似文献
74.
Christina E. Hugenschmidt James F. Lovato Walter T. Ambrosius R. Nick Bryan Hertzel C. Gerstein Karen R. Horowitz Lenore J. Launer Ronald M. Lazar Anne M. Murray Emily Y. Chew Ronald P. Danis Jeff D. Williamson Michael E. Miller Jingzhong Ding 《Diabetes care》2014,37(12):3244-3252
OBJECTIVELongitudinal evidence linking diabetic retinopathy with changes in brain structure and cognition is sparse. We used data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial to determine whether diabetic retinopathy at baseline predicted changes in brain structure or cognition 40 months later.RESULTSBaseline retinopathy was associated with lower gray matter volume (adjusted means of 470, 466, and 461 cm3 for none, mild, and moderate/severe retinopathy, respectively; P = 0.03). Baseline retinopathy also predicted a greater change in MMSE and DSST scores at 40 months in each retinopathy category (MMSE: −0.20, −0.57, and −0.42, respectively [P = 0.04]; DSST: −1.30, −1.84, and −2.89, respectively[P = 0.01]).CONCLUSIONSDiabetic retinopathy is associated with future cognitive decline in people with type 2 diabetes. Although diabetic retinopathy is not a perfect proxy for diabetes-related brain and cognitive decline, patients with type 2 diabetes and retinopathy represent a subgroup at higher risk for future cognitive decline. 相似文献
75.
76.
Rokey R; Verani MS; Bolli R; Kuo LC; Ford JJ; Wendt RE; Schneiders NJ; Bryan RN; Roberts R 《Radiology》1986,158(3):771-774
The feasibility of using magnetic resonance (MR) imaging to estimate myocardial infarct size was explored in an in vitro model using only the inherent differences in contrast between infarcted and noninfarcted myocardium. Eight dogs underwent coronary occlusion; their hearts were removed 6 hours later. Estimates of T2 for normal and infarcted myocardium were derived from MR images. Infarct size was quantified anatomically using triphenyltetrazolium-chloride (TTC) staining and compared with MR estimates. The T2 values derived from the images clearly discriminated between infarcted (126 +/- 22 msec) and normal myocardium (88 +/- 10 msec, P less than .05), providing images with good contrast between normal and infarcted myocardium. Comparable differences in T2 values were also noted from spectrometric determinations. Estimates of infarct size by MR imaging compared well with TTC estimates (r = 0.98) over a wide range of infarct sizes from 3% to 29% of the left ventricular mass. These results suggest the potential for in vivo quantification of infarct size based on the inherent contrast difference between infarcted and normal myocardium. 相似文献
77.
Glomerular size has been the subject of many studies and, in a number of settings, has a direct association with the development of glomerular sclerosis. However, the normal distribution of glomerular size has not been thoroughly evaluated in the general population in the United States. To address this issue, we analyzed the baseline biopsy specimens of 103 human donor kidneys to determine the maximal planar area (MPA) of the glomerular tuft in a heterogeneous human population. The MPA of each glomerulus was determined by measurement of sections through the vascular pole and/or origin of the proximal tubule, and was determined on each section by two methods: point counting and computer planimetry. There was very high agreement between these two methods. Multivariate analysis was used to identify significant correlates with MPA. Overall, younger donors had smaller glomeruli (P < 0.0001). Black donors had a larger MPA (23.4+/-8.6 mm2 x 10(-3)) than white donors (17.9+/-6.7 mm2 x 10(-3); P < 0.001), independent of donor age. MPA was not significantly different between genders. This heterogeneity in glomerular size may confound clinical studies if not recognized and may help explain differences in glomerular structure and function in response to injurious processes. 相似文献
78.
79.
LC Edozien MRCOG FN Mayers FRCOG MR Gowland FRCR 《International journal of clinical practice》1997,51(5):305-307
Both the incidence of twin pregnancy and the demand for prenatal diagnosis are increasing. Unfortunately, biochemical screening and ultrasound scanning are less reliable for prenatal diagnosis in twin pregnancies than in singletons. Amniocentesis and chorionic villous biopsy are usually diagnostic in singleton pregnancies but may be marred by sampling errors in twin gestations. Where a congenital anomaly has been diagnosed in a twin pregnancy, difficult decisions may have to be made, especially if one twin is unaffected. In these cases, special skills are required to ensure that adequate information, psychological support and optimal medical care are provided. 相似文献
80.
We studied the accuracy of B-scan ultrasonography to diagnose radiation-induced optic neuropathy in 15 patients with uveal melanoma. Optic neuropathy was diagnosed by an observer masked as to clinical and photographic data. We analyzed planimetry area measurements of the retrobulbar nerve before and after irradiation. The retrobulbar area of the optic nerve shadow on B-scan was quantitated with a sonic digitizer. Increased optic nerve shadow area was confirmed in 13 of 15 patients who had radiation optic neuropathy (P less than .004). The correct diagnosis was confirmed when the results of ultrasound were compared to fundus photography and fluorescein angiography. In 13 patients there was acute radiation optic neuropathy. Two patients did not show an enlarged retrobulbar optic nerve, and the clinical appearance suggested early progression to optic atrophy. Ultrasonography documents the enlargement of the optic nerve caused by acute radiation changes. 相似文献