WATER DISTRIB:PHYSICAL PROPERT:PIZZA & LMPS MOZZARELLA CHEESES:EARLY STAGE MATUR

水分配：物理特性：披萨

• 批准号: 6120942
• 负责人: SUNDARAM GUNASEKARAN
• 金额: $ 0.43万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6120942
• 关键词: Mammalia; bioimaging /biomedical imaging; biomedical resource; carbohydrates; gas; human tissue; injury; magnetic resonance imaging; nervous system; statistics /biometry

These studies were conducted using the isolated canine brain perfused with blood having a normal pH, PaO2, PaCO2, glucose, and temperature and employing a high field (9.4 Tesla), wide bore (89 mm) magnet (Bruker Instruments AM-400 WB) for the NMR studies. The region of the 31P spectrum associated with Pi was subjected to nonlinear curve fitting (Peak-Fitr, Jandel Scientific) to deconvolute the peaks. We have demonstrated that the broad inorganic phosphate (Pi) peak with a chemical shift of 4.00 to 5.25 ppm can be consistently resolved into five to seven separate peaks. A Pi buffer adjusted to pH 7.40 was infused over a 15 minute period to raise the blood Pi concentration from 2 to 4 mM. This caused peaks associated with compartments at pH 7.35 (plasma) and pH 7.18 (interstitial fluid) to increase in size. We also infused 40 mg of 2-deoxyglucose (2-DG) over a 30 minute period, and continued to collect data for an additional 30 minutes following infusion. Phosphorylation of 2-DG in the brain cells resulted in 2-DG-6-P accumulation in the phosphate monoester (PME) portion of the spectrum. The 2-DG-6-P peaks were at pHs which corresponded to the three peaks in the Pi spectrum which increased dramatically in size due to high energy phosphate hydrolysis during ischemia (pH 7.05, 6.95, and 6.82). Based on partial evidence from this and other studies, we believe these peaks represent the astrocyte, neuron, and possibly the oligodendrocyte. These studies suggested that there may normally be only three cytoplasmic and two extracellular compartments in the brain tissue Pi spectrum that are defined by pH. The Pi peak falls during 2-DG infusion. By subtracting the Pi spectrum during the 2-DG infusion from the control spectrum and fitting the difference, we find that Pi disappears from the same pH compartments in which 2-DG-6-P appears. Hyperglycemia during ischemia causes pHi to fall significantly further than during normoglycemic ischemia. Surprisingly, the hyperglycemic brains maintain some high energy phosphate after 10 minutes of complete ischemia.

这些研究是使用分离的犬脑进行的。 具有正常的pH、PaO2、PaCO2、葡萄糖和 温度和使用高场(9.4特斯拉)，宽口径(89毫米) 磁铁(布鲁克仪器AM-400WB)用于核磁共振研究。该地区 与PI相关的~(31)P谱具有非线性 曲线拟合(Peak-Fitr，Jandel Science)去卷曲峰值。 我们已经证明了宽广的无机磷(PI)峰与 4.00到5.25ppm的化学位移可以一致地分解为 五到七个不同的山峰。将PI缓冲液调节到pH 7.40， 在15分钟内输注以提高血液中的PI浓度 从2毫米到4毫米。这导致了在PH值时与隔室相关的峰值 7.35(血浆)和7.18(间质液)以增大体积。 我们还在30分钟内注入40毫克2-脱氧葡萄糖(2-DG) 期间，并继续收集数据额外的30分钟 在输液后。脑细胞中2-DG的磷酸化 导致2-DG-6-P在磷酸单酯(PME)中积累 光谱的一部分。2-DG-6-P峰在PHS处， 与PI谱中增加的三个峰相对应 由于高能磷酸盐在 缺血(pH 7.05、6.95和6.82)。基于来自 这项研究和其他研究，我们认为这些峰值代表了 星形胶质细胞、神经元，可能还有少突胶质细胞。这些研究 表明正常情况下可能只有三个细胞质和两个 脑组织PI谱中的细胞外间隔是 由pH定义。PI峰值在2-DG输注过程中下降。通过 从对照组中减去2-DG输注期间的PI谱 谱和拟合差，我们发现PI从 出现2-DG-6-P的相同pH区间。高血糖症 在缺血期间导致phi比在 正常血糖缺血症。令人惊讶的是，高血糖的大脑 在完成10分钟后保持一些高能磷酸盐 缺血症。