颅脑损伤患者脑疝前驱期特征性临床征象的研究

目的分析总结外伤性脑疝前驱期特征性临床征象及意义。方法回顾分析我科近5年238例脑疝发生前2h内的临床表现和辅助检查特点，并与同期198例未发生脑疝的重型颅脑损伤患者进行对比分析。结果脑疝组前驱期征象如昏迷加深、烦躁加重、尿失禁、侧脑室和外侧裂受压变窄伴脑基底池受压变窄、生命体征改变具有特征性，其发生率明显高于非脑疝组，两组差异有显著性意义（P〈0．01）。结论颅脑损伤患者出现脑疝前驱期特征性临床征象应作为超早期开颅的重要依据，是特殊的、迫切的手术指征。     

应用动力髁螺钉联合骨肽注射液治疗股骨髁上骨不连疗效观察

目的观察应用动力髁螺钉联合骨肽注射液治疗股骨髁上骨不连的疗效。方法53例股骨髁上骨不连患者随机分为两组：对照组（26例）和治疗组（27例）,两组均应用动力髁螺钉治疗,治疗组加用骨肽注射液治疗。随访,进行疗效评价,记录骨愈合时间和测定疼痛指数。结果治疗组疗效优于对照组。结论应用动力髁螺钉联合骨肽注射液治疗股骨髁上骨不连可提高疗效。     

骨髓基质细胞移植促进大鼠局灶性脑损伤血管生成的实验研究

目的研究骨髓基质细胞（BMSCs）移植对大鼠局灶性脑损伤血管生成的影响，探讨BMSCs移植修复大鼠脑损伤的机制。方法制备大鼠局灶性脑损伤动物模型，进行BMSCs移植，通过免疫组织化学、电镜等观察移植局部内皮细胞及微循环的变化。结果BMSCs移植后，局部凝血因子FⅧ染色阳性细胞数增加，染色加深，出现血管样结构；局部微血管内膜较光滑，内皮细胞间可见紧密连接，细胞核形态较规则，基底膜较完整，微血管管腔受压缓解。结论BMSCs移植促进损伤区周围内皮细胞增殖和新生血管形成。损伤区局部微循环得以改善进而修复脑损伤。     

Growth fraction in human brain tumors defined by the monoclonal antibody Ki-67

Summary The monoclonal antibody Ki-67, which reacts with cells in the active part of the cell cycle, was used to evaluate immunocytochemically the growth fraction in 22 primary brain neoplasms. The percentage of labelled cells reflected the histological grade of malignancy of each neoplasms. High percentage of Ki-67-positive cells were observed in one choroid plexus carcinoma (60%), one primary melanoma of meninges (40%), three medulloblastomas (40%–50%), one anaplastic astrocytoma and six glioblastomas (10%–40%). One ependymoma had 7% positive cells. Rare positive cells (1%) were present in one pilocytic astrocytoma and one ganglioglioma. Except one negative case, the meningiomas (five cases) had values of positivity ranging from 1% to 6%. Two acoustic schwannomas were negative. These results suggest that immunocytochemical staining with the Ki-67 may be a useful method for measuring the growth fraction in brain neoplasms.Supported in part by Associazione Italiana Ricerca sul Cancro and Ministero Italiano della Pubblica Istruzione     

人脑外伤后皮层核因子-κB的表达

目的 探讨核因子-κB（nuclear factor—κB，NF—κB）在人创伤性脑损伤（traumatic brain injury，TBI）后挫伤皮层中的表达情况，包括表达位置、表达强度和表达时相。方法 挫伤区皮层的标本来自24例TBI患者，取样时间为伤后5h-5d，利用凝胶电泳迁移分析法（electrophoretic mobility shift assay，EMSA）和免疫组化技术测定NF—κB的活性和表达强度。结果 在人TBI后的挫伤区皮层中，NF—κB表达明显上调，表达高峰为伤后48—72h，NF—κBP65主要在血管内皮细胞和神经胶质细胞中表达，NF—κBP50主要在神经胶质细胞和少量神经元中表达，NF—κBP65的表达强度高于NF—κBP50。结论 NF—κB在人TBI后的挫伤区皮层中表达上调，提示其可能在TBI后的病理生理过程中起着重要作用。     

Use of Fmoc-N-(2-hydroxy-4-methoxybenzyl) amino acids in peptide synthesis

The use of N, O-bisFmoc-N-(2-hydroxy-4-methoxybenzyl) amino acid derivatives in the synthesis of peptides with difficult sequences has already been described. With these amino acid derivatives the reversible protecting group 2-hydroxy-4-methoxybenzyl (Hmb) for the backbone amide bonds of peptide chains is introduced, and thus the aggregation due to hydrogen-bond interchain association is inhibited. This paper describes the synthesis and use of Fmoc-N-(2-hydroxy-4-methoxybenzyl)amino acid derivatives as an alternative means of introducing Hmb backbone protection. These new monoFmoc derivatives were obtained in higher yield than the bisFmoc derivatives. Coupling yields to the amino peptide resin were the same as those obtained with bisFmoc derivatives, under the TBTU/HOBt/DIEA conditions. We also compared different syntheses of a difficult peptide with the Fmoc approach [triple coupling, capping, use of chaotropic agents, backbone protection using monoFmoc (Hmb)Ala] and with optimized Boc chemistry. Both the backbone protection and optimized Boc chemistry approaches gave the desired product in excellent yield and purity. © Munksgaard 1997.     

BIOCHEMICAL CORRECTION IN THE SYNDROME OF HYPERTENSION AND HYPERKALAEMIA BY SEVERE DIETARY SALT RESTRICTION SUGGESTS RENIN-ALDOSTERONE SUPPRESSION CRITICAL IN PATHOPHYSIOLOGY

1. Plasma potassium and chloride concentrations were raised and plasma renin activity, aldosterone, bicarbonate and arterial pH were reduced in two brothers with the syndrome of hypertension and hyperkalaemia with normal glomerular filtration rate (Gordon's syndrome), on unrestricted or moderately restricted sodium diets. 2. These abnormalities were corrected in both patients within 10 days of severe sodium restriction. 3. Pressor sensitivity to cold and angiotensin II decreased on low sodium diet, associated with a fall in blood pressure. 4. Increasing distal tubular sodium delivery by infusion of normal saline increased fractional excretion of potassium when aldosterone had been stimulated by severely restricted sodium diet, but not when aldosterone levels were low on unrestricted sodium diet. 5. These findings are consistent with excessive sodium reabsorption as the primary renal lesion in Gordon's syndrome, leading to volume expansion and suppression of renin and aldosterone. Severe dietary sodium restriction leading to volume contraction, by stimulating renin and aldosterone and promoting kaliuresis, corrects the abnormalities.     

Chemical shift differences between free and Fab-bound peptide correlate with a two-stage selection of peptide sequences from a random phage display library to delineate critical and non-critical residues for antibody recognition

Epitope libraries provide a method to identify peptide ligands for antibodies, receptors or other binding proteins. As such, they provide a powerful tool to rapidly identify lead ligands in the drug discovery process. In an attempt to correlate structural information with the results from peptide screening, we have used NMR spectroscopy of peptide/antibody complexes to demonstrate that core residues identified through a two-stage selection process undergo a larger structural change upon binding antibody than do positions in the peptide amenable to a variety of side chains. The model system used was the M2 monoclonal antibody/Flag? octapeptide epitope system. We have analyzed two peptides: Ac-Asp-Tyr-Lys-Leu-Gly-Asp-Asp-Leu-NH₂ (peptide l), which contains several non-core positions randomized, and Ac-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Leu-NH₂ (peptide 2), which closely corresponds to the original Flag? sequence. Enrichment of the peptides with ¹⁵N facilitated the investigation by permitting spectral editing of the peptide resonances in the presence of antibody. For peptide 1 the absolute shifts for the free vs. Fab-bound peptide were found to be largest for the amide groups of Asp-1 and Asp-6, in agreement with classification of these residues as critical by the phage display library selection process. For peptide 2 the largest absolute shifts were observed for Asp-1 and Asp-4, with the other aspartic acid residues also showing significant but smaller changes. © Munksgaard 1995.     

Pharmacological properties of Ca2+-activated K+ currents of ramified murine brain macrophages

Using the whole-cell configuration of the patch clamp technique, calcium-activated potassium currents (I_K,Ca) were investigated in ramified murine brain macrophages. In order to induce I_K,Ca the intracellular concentration of nominal free Ca²⁺ was adjusted to 1μM. The Ca²⁺-activated K⁺ current of brain macrophages did not show any voltage dependence at test potentials between –120 and +30mV. A tenfold change in extracellular K⁺ concentration shifted the reversal potential of I_K,Ca by 51mV. The bee venom toxin apamin applied at concentrations of up to 1μM did not affect I_K,Ca. Ca²⁺-activated K⁺ currents of ramified brain macrophages were highly sensitive to extracellularly applied charybdotoxin (CTX). The half-maximal effective concentration of CTX was calculated to be 4.3nM. In contrast to CTX, the scorpion toxin kaliotoxin did not inhibit I_K,Ca at concentrations between 1 and 50nM. Tetraethylammonium (TEA) blocked 8.0% of I_K,Ca at a concentration of 1mM, whereas 31.4% of current was blocked by 10mM TEA. Several inorganic polyvalent cations were tested at a concentration of 2mM for their ability to block I_K,Ca. La³⁺ reduced I_K,Ca by 72.8%, whereas Cd²⁺ decreased I_K,Ca by 17.4%; in contrast, Ni²⁺ did not have any effect on I_K,Ca. Ba²⁺ applied at a concentration of 1mM reduced I_K,Ca voltage-dependently at hyperpolarizing potentials. Received: 17 January / Accepted: 5 May 1997