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41.
Thirteen methods of prepararing leukocyte-poor red blood cells were compared for their effectiveness in removing leukocytes. When the starting material was six to ten days old, the residual leukocyte count was three to four times lower than when fresh material was used and no granulocytes could be found. The most effective manual procedure was a single upright sedimentation of six- to ten-day-old saline-diluted red cells. Inverted sedimentation was no more effective in leukocyte depletion than upright sedimentation. Automated cell processors were no more effective than several of the better manual methods. Freezing and deglycerolizing resulted in a ten-fold improvement in leukocyte removal with less red blood cell loss but at higher cost than the nonfreezing methods. The study indicates that unless the minimal leukocyte count of frozen red blood cells is essential, a single upright sedimentation of saline-diluted, six- to ten-day-old red blood cells is currently the most effective procedure for preparing leukocyte-poor red blood cells. 相似文献
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Maarten HT Zwartbol Ina Rissanen Rashid Ghaznawi Jeroen de Bresser Hugo J Kuijf Kim Blom Theo D Witkamp Huiberdina L Koek Geert Jan Biessels Jeroen Hendrikse Mirjam I Geerlings 《Journal of cerebral blood flow and metabolism》2021,41(11):3127
We determined the occurrence and association of cortical cerebral microinfarcts (CMIs) at 7 T MRI with risk factors, neuroimaging markers of small and large vessel disease, and cognitive functioning. Within the Medea-7T study, a diverse cohort of older persons with normal cognition, patients with vascular disease, and memory clinic patients, we included 386 participants (68 ± 9 years) with available 7 T and 1.5 T/3T brain MRI, and risk factor and neuropsychological data. CMIs were found in 10% of participants and were associated with older age (RR = 1.79 per +10 years, 95%CI 1.28–2.50), history of stroke or TIA (RR = 4.03, 95%CI 2.18–7.43), cortical infarcts (RR = 5.28, 95%CI 2.91–9.55), lacunes (RR = 5.66, 95%CI 2.85–11.27), cerebellar infarcts (RR = 2.73, 95%CI 1.27–5.84) and decreased cerebral blood flow (RR = 1.35 per −100 ml/min, 95%CI 1.00–1.83), after adjustment for age and sex. Furthermore, participants with >2 CMIs had 0.5 SD (95%CI 0.05–0.91) lower global cognitive performance, compared to participants without CMIs. Our results indicate that CMIs on 7 T MRI are observed in vascular and memory clinic patients with similar frequency, and are associated with older age, history of stroke or TIA, other brain infarcts, and poorer global cognitive functioning. 相似文献
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吸收度线性组合分光光度法的初步探讨 总被引:11,自引:0,他引:11
本文在联立方程法(包括双波长法、系数倍率法)、三波长法、正交函数法的基础上提出一种新的计算分光光度测定法——吸收度线性组合法。文中对上述诸法进行了比较,并从理论和实验上证明了新法只要合理组合,随着测试点数的增加,测定精度可望改善。 相似文献
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Duc T Quach Toru Hiyama Fumio Shimamoto Quang D Le Linh X Ho Nhu HT Vu Masaharu Yoshihara Naomi Uemura 《World journal of gastroenterology : WJG》2014,20(17):5087-5091
AIM:To assess the value of a new test for the diagnosis of Helicobacter pylori(H.pylori) infection,Rapirun H.pylori Antibody Stick(Rapirun Stick),in a Vietnamese population.METHODS:Eligible patients without previous history of H.pylori eradication were recruited.Rapid urease test(RUT) and histologic examination were used to diagnose the H.pylori infection.Patients were considered H.pylori positive when the RUT results were positive and/or the bacteria were detected histologically.Rapirun Stick tests were performed using urine samples,and the results were compared with the other 2 methods.RESULTS:We enrolled 200 patients with a mean age of 36(range,18-76) years.There were 116 females and 84 males.Of the 200 patients,111(55.5%) were diagnosed as being H.pylori positive.The sensitivity,specificity,and accuracy of the Stick test were 84.7%,89.9%,and 87.0%,respectively.There were 17(8.5%) falsenegative patients and 9(4.5%) false-positive patients.CONCLUSION:The Rapirun Stick test has high sensitivity,specificity,and accuracy for the diagnosis of H.pylori infection in the Vietnamese population.The test can be clinically applied in Vietnamese populations. 相似文献
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Increased trinucleotide repeat instability with advanced maternal age 总被引:15,自引:14,他引:1
Nucleotide repeat instability is associated with an increasing number of
cancers and neurological disorders. The mechanisms that govern repeat
instability in these biological disorders are not well understood. To
examine genetic aspects of repeat instability we have introduced an
expanded CAG trinucleotide repeat into transgenic mice. We have detected
intergenerational CAG repeat instability in transgenic mice only when the
transgene was maternally transmitted. These intergenerational instabilities
increased in frequency and magnitude as the transgenic mother aged.
Furthermore, triplet repeat variations were detected in unfertilized
oocytes and were comparable with those in the offspring. These data show
that maternal repeat instability in the transgenic mice occurs after
meiotic DNA replication and prior to oocyte fertilization. Thus, these
findings demonstrate that advanced maternal age is an important factor for
instability of nucleotide repeats in mammalian DNA.
相似文献
50.
Recombinant human granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem/progenitor cells (PBPC) have replaced bone marrow (BM) harvests for autologous transplantation after myeloablative therapy in cancer patients. G-CSF-mobilized PBPC from healthy donors contain one log excess of T lymphocytes representing a potential risk for graft-versus-host disease (GVHD). However, recent pilot clinical studies of G-CSF-mobilized allogeneic PBPC transplantation have shown rapid haematological recovery and no severe acute GVHD except in a very few cases. Therefore, the risk of inducing severe acute GVHD is not as high as was expected during the pioneering period of allogeneic PBPC transplantation.The present study was performed to address the possible reasons for the rapid haematological recovery and the absence of severe acute GVHD observed after allogeneic PBPC transplantation by comparing the contents and subsets of CD3+ and CD34+ G-CSF-mobilized PBPC (n = 31) with those of BM (n = 26) allografts from healthy adult donors. The present results revealed that the phenotypic profiles of CD3+ and CD34+ cells differ between PBPC and BM allografts. The single PBPC leukapheresis product contained 10 times more mononuclear cells, 1.5 times more CD34+ cells, 5.5 times more CD3+ T lymphocytes, 3 times more CD19+ B lymphocytes and 3.8 times more CD14+ monocytes than the single BM harvest. Both CD34+CD33+ myeloid progenitor cells and CD34+HLA-DR- long-term reconstituting haemopoietic stem cells were significantly increased in the CD34+ G-CSF-mobilized PBPC compared with the CD34+ BM cells; median 73.1% and 30.4% vs 60.6% and 5.0%, respectively, P < 0.01.The percentage of CD3+ cells coexpressing CD4 (T helper/inducer) was similar in both PBPC and BM allografts, 47.2% and 45.6%, respectively, whereas the percentage of CD3+ cells coexpressing CD8 (T suppressor/cytotoxic) was significantly decreased in PBPC compared with BM; 37.0% vs 55.9%, p < 0.01. 相似文献