个体成长模型在纵向研究中的应用--以大学新生交往主动性为例

目的介绍个体成长模型方法对大学新生适应能力中交往主动性的3次测查数据采用普通回归模型和个体成长模型进行分析。结果个体成长模型的拟合度比普通回归模型的拟合度要好,个体成长模型可在个体水平上分析个体随时间产生的变化。结论个体成长模型具有许多优点,熟悉这种重要的分析方法对纵向数据研究者是非常有益处的。     

谷氨酰胺和生长激素对短肠综合征患者肠道代偿作用

目的探讨谷氨酰胺和生长激素对短肠综合征(SBS)患者的肠道代偿作用。方法26例短肠综合征患者残余小肠长度为0～100(中位数42.5)cm,手术后接受肠外营养(PN)支持3-52个月,联合应用生长激素(GH)(0.10±0.06)mg·kg-1·d-1和谷氨酰胺(GLN)(0.30±0.17)g·kg-1·d-1进行肠道促代偿治疗。结果26例接受GH加GLN治疗的SBS患者,其中9例(34.6%)治疗后近期内完全摆脱PN;8例(30.8%)经治疗后明显减少了PN用量,从每周需要PN(6.0±1.0)d下降至(4.2±1.0)d,每周PN需要量从(13.6±5.2)L降至(8.2±3.3)L;9例(34.6%)在治疗后仍依赖PN维持。结论经过合适的营养支持和肠道促代偿治疗,大多数短肠综合征患者残留肠道能充分代偿,完全摆脱PN或减少PN用量,长期健康生存。     

口腔鳞状细胞癌颈淋巴转移范围和临床病理因素间的相关性研究

目的探讨口腔鳞状细胞癌颈淋巴转移范围和临床病理因素间的关系。方法对26例已存在颈淋巴转移的原发口腔癌患者，进行颈淋巴转移范围和患者的临床病理资料的统计分析，寻找影响转移范围的主要因素。结果单因素分析发现，肿瘤生长方式和分化程度与转移范围相关。多因素分析显示，肿瘤生长方式(浸润型)和肿瘤转移范围相关。结论对颈淋巴已有转移的口腔癌患者，若原发灶为浸润性生长，肿瘤倾向于更大范围的转移。对已有颈淋巴转移的口腔癌患者，颈淋巴清扫术范围的制定，主要考虑肿瘤生长方式，适当考虑肿瘤发病部位、厚度、大小和细胞的分化程度，可以不考虑患者年龄和性别。     

Pharmacodynamic Modeling for Change of Locomotor Activity by Methylphenidate in Rats

Purpose. The locomotive activity changes after intravenous (i.v.) administration of methylphenidate (MPD) in rats were pharmacodynamically analyzed. Methods. MPD concentration in plasma, MPD concentration and dopamine (DA) level in striatal dialysate collected by microdialysis method, and the locomotor activity after i.v. administration of MPD (2, 5 and 10 mg/kg doses) were used for the analysis. Results. The transport of MPD from plasma to the interstitial fluid in the brain could be expressed by the linear two-compartment model. The clockwise hysteresis between the MPD concentration and the DA level in the dialysate could be explained by the pharmacodynamic model considering Michaelis-Menten type reuptake process of the extracellular DA into the terminal of the dopaminergic nerve and its competitive inhibition by the extracellular MPD. The inhibition constant (K_i) of MPD for DA reuptake was estimated to be 41.3 ± 73.8 nM (mean ± SE), which was closely consistent with the in vitro value after correction with dialysis recovery. The relationship between DA level in dialysate and locomotor activity was expressed by the Emax model considering two contrary effects, hyperkinesia and stereotypy. The bi-phasic locomotor activity-time profiles after high dose of MPD could be represented by this model. Conclusions. The developed model made it possible to explain the tolerance in DA increase and the complicated locomotive change induced by MPD, and may be useful for other DA reuptake inhibitors, such as amphetamine and methamphetamine.     

碱性成纤维细胞生长因子（bFGF）加速猪背部创伤修复的实验研究

实验采用猪背部创伤模型，观察重组的碱性成纤维细胞生长因子（ｂＦＧＦ）对创伤修复的作用。在无菌条件下用特制打孔器在猪背部切割皮肤，形成２．５ｃｍ２的园型创面。将１５０个创面分成５组，分别以ｂＦＧＦ（６０ｕ／ｃｍ２创面），ｂＦＧＦ（（６０ｕ／ｃｍ２创面）加ＳＤ－Ａｇ、ＳＤ－Ａｇ、生理盐水以及不治疗等方法处理，每间隔一天换药一次。实验结果表明，ｂＦＧＦ具有显著促进肉芽组织生长、加速创面再上皮化率以及增加创面愈合组织抗张力强度等作用。ＦＧＦ显著促修复效应的确切机制尚不完全清楚，可能包括直接与间接效应两方面。     

产科诊断剂量超声波对培养细胞影响的实验研究

采用模拟在人体中使用的实测超声剂量，对体外培养的Ｌ－９２９株细胞进行辐照，通过细胞回复能力试验，观察回复前后的细胞增殖与抑制。对体外培养的人胚肺纤维细胞经１次及５次辐照，观察了ＤＮＡ及细胞核面积的影响。并通过电镜观察了细胞超微结构的变化。上述实验结果，均提示经辐照后细胞有增殖趋向     

A binding study of phospholipase A2 with lecithin,lysolecithin and their tetrahedral intermediates using molecular modeling

We used molecular modeling to examine the binding of 1, 2-dioctanoyl-sn-glycero-3-phosphocholine (a lecithin), 1-octanoyl-sn-glycero-3-phosphocholine (a lysolecithin) and their tetrahedral intermediates in the catalytic site of phospholipase A₂ (PLA₂). We performed energy minimization on each complex, computed the binding energy, determined the relative binding energy among the complexes and calculated the difference in inter- and intramolecular energies of the components in the complexes. We found that the calculated orientation of the sn-1 ester bond of lysolecithin in the active site is similar to that of the sn-2 ester bond in lecithin, thus permitting PLA₂ to hydrolyze lysolecithin using the same mechanism as it uses to hydrolyze lecithin. On the other hand, the binding of lecithin is energetically more favorable by 4.5 kcal/mol than the binding of lysolecithin to the enzyme, and the binding of the lecithin tetrahedral intermediate is also energetically more favorable by 19.7 kcal/mol than the binding of the lysolecithin tetrahedral intermediate to the enzyme, which explains why lecithin is a better substrate than lysolecithin in the catalytic site. These results indicate that the activation energy for the hydrolysis of lysolecithin is higher than that for lecithin, consistent with the observed slower rate for the hydrolysis of lysolecithin.     

Regeneration of kidney tubular epithelial cells

Conclusion The mechanisms that regulate regeneration of kidney epithelial cells after acute tubular necrosis are poorly understood. Repair of the nephron can take place in the adverse systemic metabolic setting caused by failure of renal function. This clinical observation suggests that factors released at the site of the tubular insult can mediate repair. Studies carried out in this and other laboratories show that kidney epithelial cells can release and respond to polypeptide growth factors which may thereby contribute to renal regeneration by autocrine and paracrine mechanisms. Specific growth factors secreted by cells and deposited in the tubular basement membrane prior to injury may subsequently participate in nephron repair. In addition, adenine nucleotides released from injured or dying cells at the injury site or provided exogenously could stimulate surviving renal epithelial cells at the edges of the wound to migrate along the basement membrane to rapidly reepithelialize the nephron and subsequently initiate mitogenesis to replace cells lost by necrosis.The nephrotoxic effect of many agents used in cancer chemotherapy and the older age of patients undergoing complicated surgical procedures has increased the incidence of ARF, whereas the mortality rate has not changed since the early 1950s [22]. Thus there is considerable need for innovative therapeutic strategies. An important goal of future research efforts is to identify new growth factors that facilitate migration, differentiation, and proliferation of renal epithelial cells at sites of tubular necrosis. Isolation and use of these agents in combination with dialysis and nutritional support could speed renal regeneration and thereby improve the outcome in patients with this condition.Abbreviations ARF acute renal failure - ECM extracellular matrix - EGF epidermal growth factor - FGF fibroblast growth factor - IGF insulin-like growth factor - MGSA melanocyte growth-stimulating activity - PDGF platelet-derived growth factor - IGF transforming growth factor     

Flumazenil exerts intrinsic activity on sleep EEG and nocturnal hormone secretion in normal controls

The physiological function of benzodiazepine (BDZ) receptors includes regulation of sleep and neuroendocrine activity. Most of the pharmacological effects of BDZ are blocked by flumazenil. However, recent neurological and behavioral studies suggest that flumazenil has its own central intrinsic activity. This issue was addressed in a study of the sleep EEG and the nocturnal secretion of growth hormone and cortisol in ten normal male controls, who were given flumazenil either alone or in combination with the BDZ agonist midazolam, placebo and midazolam alone. Flumazenil prompted an increase in sleep onset latency, a decrease in slow wave sleep and an increase in wakefulness. Plasma cortisol concentrations after flumazenil administration were lower than after midazolam. Both flumazenil and midazolam decreased nocturnal growth hormone secretion. After simultaneous application of both BDZ receptor ligands the growth hormone blunting was amplified. Our study demonstrates that at the level of the sleep EEG and neuroendocrine activity flumazenil is capable of exerting both agonistic and inverse agonistic or antagonistic effects.Parts of this study were presented at the 69th Meeting of the Deutsche Physiologische Gesellschaft, Freiburg, 6–8 March, 1991