Analysis with NMR localized spectroscopy of rat brainin vivo andex vivo

The volume-selected MRS of rat brain was performed on a 200 MHz broad horizontal-bore nuclear magnetic resonance imaging spectromete;. The localized proton spectroscopy of rat brain was acquired using the double spin-echo pulse sequence (PRESS) to select the position and size of the volume. Water signal was suppressed by CHESS sequence which was composed of chemical shift selective rf pulses and dephasing gradients. The parameterTE was taken as 40 ms and 135 ms in the experiment. The localized MRS of the rat brain with the status of live and death was obtained in variousTE values. Results showed that volume-selected proton MRS of the rat brainin vivo with longerTE consisted mainly of signals produced by N-acetylaspartate (NAA), creatine (Cre), choline (Cho) and the lactate spectral peak occurred in the MRS of the rat brainex vivo. On the other hand, the MRS of the rat brain with shorterTE contained glutamine/glutamate and lipid signals besides those signals mentioned previously. Although the information abstracted from the MRS of the rat brain with shorterTE may be more than that with longerTE, the spectral resolution of the MRS with shorterTE was slightly worse. In addition, it might indicate that the absolute concentration of NAA was decreased in dead rat brain because the SNR of NAA peak in the MRSex vivo got lower.     

不同免疫程序制备17β－雌二醇抗体的效果比较

比较了皮内多点注射和肌肉注射配合静脉注射两种免疫程序制备１７β－雌二醇抗体的效果。证明采用皮内多点注射的免疫程序，比用肌肉注射配合静脉注射的程序更易产生高滴度的抗体。     

不同年龄大鼠双核肝细胞变化的研究

胶原酶灌注法、固定液灌注法及针头法用于肝细胞的分离效果良好。本文根据大鼠的不同年龄和实验需要,分别采用以上三种方法,对出生后4天到两年以上的12个年龄组的大鼠进行了双核肝细胞数统计,并与切片法做了对照。双核肝细胞随大鼠的年龄变化很大。出生后不久,只有一个很低的值,20天后开始迅速增加,40天左右达到最大值(45％),成年期降至25％,其后,直到老年基本趋于稳定状态。切片法获得的双核百分率只有灌注法的1/3到1/2,说明用切片法统计双核数是不准确的。双核百分率与生态学上的其他指标结合起来可以推测大鼠的年龄。     

Peptide YY enhances NaCl and water absorption in the rat colon in vivo

Peptide YY (PYY) is thought to possess paracrine and endocrine functions. The highest concentrations of this peptide are in the colonic mucosa. The effect of PYY on electrolyte and water transport in the rat colon was studied in vivo. Under urethane anesthesia, rat colonic loops were perfused at a constant rate with physiological buffer solution containing phenol red as a nonabsorbable volume marker, and net movements of water, sodium, chloride and potassium in the perfused colon were determined every 10 min. Intravenous administration of PYY produced a dose-dependent increase in the net absorption of sodium chloride and water, as well as a decrease in the net secretion of potassium. PYY inhibited the reduction in net absorption of sodium chloride and water evoked by vasoactive intestinal peptide (VIP), but did not affect the VIP-evoked increase in net potassium secretion.These findings suggest that PYY acts as an enhancer of sodium chloride and water absorption and as an antagonist to VIP-induced secretion in the colon.     

不同环境的培养对小白鼠学习记忆能力的影响

本文对不同环境下培养的小白鼠进行了学习、记忆能力的比较研究。结果表明:丰富环境下成长的个体,其学习记忆能力好于单调环境下成长的个体。     

复方灵芝对延缓大鼠胸腺衰退的影响

本研究用生后７—６０ｄ不同发育期的Ｗｉｓｔａｒ大鼠，观察复方灵芝对其延缓胸腺衰退，提高机体免疫能力的影响．运用统计学和组织学方法，观察了其发育和衰退的情况．与对照组相比较，实验组胸腺的重量增加明显，胸腺重和体重的比例也相应增加，生后６０ｄ时皮质与髓质的界限清晰．结果表明复方灵芝具有延缓胸腺衰退的作用．     

六年中裸小鼠繁殖群动物自发性肿瘤发病情况研究

对饲养于ＳＰＦ条件下的４６６只ＮＣ系自育选留的繁殖群小鼠自发性中瘤发病情况进行了６年观察，研究其中包括纯合子雄鼠（ｎｕ／ｎｕ）１６４只，杂合了雄鼠（ｎｕ／＋）３０２只。每只动物的平均观察时间均达７个月以上，淘汰时均详细解剖学检查，检出病变者进行病理组织学及透射电镜观察确诊。多数肿瘤病例结合裸鼠间可移植性鉴定。共检出自发性肿瘤７例，发生于纯合子裸鼠（♂，ｎｕ／ｎｕ）５例，杂合子裸鼠（♂，ｎｕ／＋）２例。本结果表明，在相同饲养环境条件下，裸鼠（♂，ｎｕ、／ｎｕ）的自发性肿瘤发病率（３．０４％）比其同系的有胸腺杂合子裸鼠（♀，ｎｕ／＋）（０．６６％）明显增高，两者发病比较有显著性差异（Ｐ＜０．０５），且前者的平均发瘤鼠龄比后者为短。结果支持了免疫功能缺陷的裸鼠比其同系免疫功能正常鼠有更高的自发性肿瘤发生的观点。且表明了ＮＣ系裸鼠的自发性肿瘤以恶性上皮性肿瘤为主。此外作者针对前人的观察结果，提出了对一裸群体的自发性肿瘤的正确评价，必须是在相同的生存环境条件下，相同的观察时间内与相同品系或相同基因背景的有胸腺小鼠进行比较，并经详细的病理学检查，才能得出较客观可靠的结论这一见解。