Rapid astrocyte death induced by transient hypoxia, acidosis, and extracellular ion shifts

Death of astrocytes requires hours to days in injury models that use hypoxia, acidosis, or calcium paradox protocols. These methods do not incorporate the shifts in extracellular K(+), Na(+), Cl(-), and Ca(2+) that accompany acute brain insults. We studied astrocyte survival after exposure to hypoxic, acidic, ion-shifted Ringer (HAIR), with respective [Ca(2+)], [K(+)], [Na(+)], [Cl(-)], and [HCO(-)(3)] of 0.13, 65, 51, 75, and 13 mM (15% CO(2)/85% N(2), pH 6.6). Intracellular pH (pH(i)) was monitored with the fluorescent dye BCECF. Cell death was indicated by a steep fall in the pH-insensitive, 440-nm-induced fluorescence (F440) and was confirmed by propidium iodide staining. After 15-40-min HAIR exposure, reperfusion with standard Ringer caused death of most cultured (and acutely dissociated) astrocytes within 20 min. Cell death was not prevented if low Ca(2+) was maintained during reperfusion. Survival fell with increased HAIR duration, elevated temperature, or absence of external glucose. Comparable durations of hypoxia, acidosis, or ion shifts alone did not lead to acute cell death, while modest loss was noted when acidosis was paired with either hypoxia or ion shifts. Severe cell loss required the triad of hypoxia, acidosis, and ion shifts. Intracellular pH was significantly higher in HAIR media, compared with solutions of low pH alone or with low pH plus hypoxia. These results indicate that astrocytes can be killed rapidly by changes in the extracellular microenvironment that occur in settings of traumatic and ischemic brain injury.     

Effect of elevated K(+), hypotonic stress, and cortical spreading depression on astrocyte swelling in GFAP-deficient mice

Glial fibrillary acidic protein (GFAP) is the main component of intermediate filaments in astrocytes. To assess its function in astrocyte swelling, we compared astrocyte membrane properties and swelling in spinal cord slices of 8- to 10-day-old wild-type control (GFAP(+/+)) and GFAP-knockout (GFAP(-/-)) mice. Membrane currents and K(+) accumulation around astrocytes after a depolarizing pulse were studied using the whole-cell patch-clamp technique. In vivo cell swelling was studied in the cortex during spreading depression (SD) in 3 to 6-month-old animals. Swelling-induced changes of the extracellular space (ECS) diffusion parameters, i.e., volume fraction alpha and tortuosity lambda, were studied by the real-time iontophoretic tetramethylammonium (TMA(+)) method using TMA(+)-selective microelectrodes. Morphological analysis using confocal microscopy and quantification of xy intensity profiles in a confocal plane revealed a lower density of processes in GFAP(-/-) astrocytes than in GFAP(+/+) astrocytes. K(+) accumulation evoked by membrane depolarization was lower in the vicinity of GFAP(-/-) astrocytes than GFAP(+/+) astrocytes, suggesting the presence of a larger ECS around GFAP(-/-) astrocytes. Astrocyte swelling evoked by application of 50 mM K(+) or by hypotonic solution (HS) produced a larger increase in [K(+)](e) around GFAP(+/+) astrocytes than around GFAP(-/-) astrocytes. No differences in alpha and lambda in the spinal cord or cortex of GFAP(+/+) and GFAP(-/-) mice were found; however, the application of either 50 mM K(+) or HS in spinal cord, or SD in cortex, evoked a large decrease in alpha and an increase in lambda in GFAP(+/+) mice only. Slower swelling in GFAP(-/-) astrocytes indicates that GFAP and intermediate filaments play an important role in cell swelling during pathological states.     

Glycogenosis Type V (McArdle’s Disease) Mimicking Atypical Myositis

A 13-year-old girl was referred to our clinic because of a positive rheumatoid factor test, muscle pain and weakness. Laboratory evaluation revealed an increased ESR, hypergammaglobulinaemia, antinuclear antibodies, circulating immune complexes, complement consumption and elevated serum creatine kinase (CK) activity. A needle biopsy of the dolent muscle showed normal routine histology. Immunohistochemistry disclosed single lymphocytes and a weak myocytic HLA class I expression. The diagnosis of myositis was considered and corticosteroids were initiated, leading to an increase of complement levels and a decrease of CK-activity and ESR. She subjectively felt stronger but still reported exercise intolerance and metabolic myopathy was considered. Myophosphorylase activity was completely lacking, establishing the diagnosis of McArdle's disease. CK level was found to be elevated in an obese 4-year-old brother too, who refused extensive walking but reported no muscle pain. Myophosphorylase deficiency was demonstrated by histochemistry and by biochemical analysis of his muscle. The female case illustrates that in children with the clinical picture of inflammatory myopathy and serological but not clinical response to therapy underlying metabolic muscle disorders should be excluded. Since the pathogenesis of polymyositis remains unclear, we speculate that inflammatory changes observed in the muscles may have been initiated by muscular damage resulting from the underlying metabolic disease. The serological changes remained unexplained and may contribute to a so far undeterminable connective tissue disease.     

不同碘摄入量对大鼠碘代谢及甲状腺功能影响

目的观察不同碘酸钾（KIO3）摄入量的大鼠模型碘代谢及甲状腺功能的变化并探讨KIO3的安全性。方法Wistar大鼠随机分为6组,分别给予低碘、适碘和高碘（分别为适碘组的5,10,50,100倍）饮食,检测3、6和12个月时尿碘水平和甲状腺含碘量,分析碘代谢变化;分别检测血清总三碘甲腺氨酸（TT3）、总甲状腺素（TT4）、游离三碘甲腺氨酸（FT3）、游离甲状腺素（FT4）浓度及甲状腺组织中三碘甲腺氨酸（T3）、甲状腺素（T4）含量来衡量甲状腺功能。结果LI组尿碘水平和甲状腺含碘量,以及血清、甲状腺组织中的甲状腺激素水平均显著低于适碘组,呈明显甲状腺功能低下;各HI组尿碘排泄量显著增加,增加幅度与碘摄入量的倍数相一致,但与适碘组比较,各HI组甲状腺含碘量最高仅2倍左右;另外,HI组随着碘摄入的增加,血清和甲状腺组织中的甲状腺激素水平也出现降低趋势,呈现一定的甲状腺功能低下。结论长期碘缺乏和碘过量均可导致大鼠甲状腺功能低下,但以碘缺乏所致的甲状腺功能低下更为明显。同时大鼠存在适应高碘的机制,对高碘摄入具有更强的耐受性,并证实KIO3的安全性。     

硫酸铝钾对小鼠胚胎中脑细胞增殖和分化的影响

目的研究硫酸铝钾对胎鼠中脑细胞增殖和分化的影响。方法采用细胞微团培养法,观察不同浓度(0～100μmol/L)的硫酸铝钾对胎鼠中脑细胞增殖和分化的影响。结果硫酸铝钾对离体培养的中脑细胞的增殖和分化均有抑制作用,其半数增殖抑制浓度(IP50)为45.03μmol/L、半数分化抑制浓度(ID50)为3.92μmol/L,IP50/ID50=11.5。结论硫酸铝钾对细胞分化有特异抑制作用。     

ICAM-1、CD44V6与食管鳞癌淋巴结转移关系的研究

目的探讨黏附分子ICAM-1、CD44V6在食管鳞癌淋巴结转移中的作用。方法采用S—P免疫组化染色法检测食管鳞癌组织中ICAM-1、CD44V6的表达情况。结果在发生淋巴结转移的食管鳞癌组织中ICAM-1、CD44V6的阳性表达率分别为69．2％（18／26）、76．9％（20／26），且两者具有明显的一致性（P〈0．05）。结论ICAM-1、CD44V6与食管鳞癌的淋巴结转移情况密切相关，食管鳞癌淋巴结的转移是一个涉及多种黏附分子参与的复杂过程。     

益气活血Ⅴ号方加葛根素治疗老年短暂性脑缺血观察

目的:观察中药益气活血Ⅴ号方加葛根素治疗老年短暂性脑缺血的疗效。方法:将72例诊断为老年短暂性脑缺血病人,随机分为治疗组与对照组,各36例。治疗组用自拟益气活血Ⅴ号方加葛根素注射液治疗,对照组用西药低分子右旋糖酐与西比灵治疗,疗程20天,观察发作期及停药后3个月复发病况。结果:在短暂性脑缺血发作期,治疗组比对照组缩短发病时间。在疗程内,治疗组未出现任何症状,对照组有40%病例出现不同程度头晕、头痛、乏力症状。停药后,追踪远期疗效的3个月中,治疗组未见1例复发,对照组有9例复发。经颅多普勒检查:治疗前与治疗后,椎—基底动脉及左、右大脑中动脉供血,治疗组优于对照组(P<0.01)。结论:治疗组治疗老年短暂性脑缺血,近期与远期疗效明显优于对照组,是治疗本病较理想方法。     

CD44V6在肺鳞癌中的表达

目的 探讨CD44V6在肺鳞癌中的表达及其与肺鳞癌发生发展的相关性 。方法 应用免疫组织化学ABC法检测35例手术切除的新鲜肺鳞组织及 其癌旁正常肺组织的CD44V6蛋白,并将检测结果与患者的临床病理资料进行对照分析。结果 CD44V6在肺磷癌组织中的阳性表达率为65．7％（23／35）,而在癌旁正常肺组织中则无表达,二者差异有显著性（X^2=34．3,P＜0．01）;CD44V6在有淋巴结转移的肺鳞癌组织中的阳性表达率（84．2％,16／19）明显高于其在无淋巴结转移中的阳性表达率（43．8％,7／16）（X^2＝6．3,P＜0．01）;CD44V6阳性表达率随肺鳞癌组织分化程度的降低而或高,但无统计学意义（X^2=2．33,P＞0．05）;CD44V6在Ⅲ Ⅳ期肺鳞癌中的阳性表达率（86．7％,13／15）明显高于其在Ⅰ Ⅱ期中的阳性表达率（50％,10／20）,（X^2＝5．1,P＜0．01）;CD44V6阳性表达患者的3年生存率（30．4％,7／23）明显低于CD44V6阴性者（66．7％,8／12）（X^2＝4．2,P＜0．05）。结论 CD44V6可能与肺鳞癌的发生有关;CD44V6阳性预示肺鳞癌可能发生淋巴结转移,并对肺鳞癌的临床分期起到一定作用;CD44V6阳性还可作为评估肺鳞癌患者预后的参考指标。     

Gender and seasonally related differences in myocardial recovery and susceptibility to sotalol-induced arrhythmias in isolated rabbit hearts

INTRODUCTION: Gender differences and seasonal variations in cardiac electrophysiology and susceptibility to arrhythmias have been described clinically. The present study was undertaken to determine if there are similar gender and seasonally related differences in the electrophysiology of the rabbit heart. METHODS AND RESULTS: We analyzed epicardial electrograms, left ventricular endocardial monophasic action potentials (MAPs), and simulated X and Y lead ECGs from 145 isolated rabbit hearts studied over a period of 41 months. Hearts from males had seasonal increases in the duration of myocardial recovery. During the months of June to September compared with October to January and February to May, epicardial activation-recovery intervals (231.6+/-23.4 vs 215.6+/-19.2 and 213.5+/-18.8 msec, P = 0.003), MAP durations (256.5+/-25.4 vs 237.0+/-19.6 and 230.7+/-26.4 msec, P < 0.001), and QT intervals (278.3+/-25.6 vs 267.3+/-11.8 and 261.3+/-13.0 msec, P = 0.037) were longer. Overall, hearts from females had shorter QT intervals than males (257.7+/-15.7 vs 270.1+/-20.3 msec, P < 0.001), and this difference was reflected in their shorter epicardial activation-recovery intervals and MAP durations. However, hearts from females showed a greater prolongation of epicardial recovery (P = 0.007) and greater incidence of arrhythmias (P < 0.001) with sotalol than males. Also, the incidence of arrhythmias was greater in the winter months October to May (P < 0.001). CONCLUSION: The isolated rabbit heart provides a spontaneous model of gender and seasonally related differences in cardiac electrophysiology and arrhythmia susceptibility. These differences may be related to variation in the expression of or regulation of the membrane ion channels mediating repolarization.     

原发性甲状腺鳞状细胞癌临床病理分析

目的:探讨原发性甲状腺鳞状细胞癌的临床病理特点、诊断及鉴别诊断。方法:分析5例原发性甲状腺鳞状细胞癌的临床、病理及随访资料,对标本进行HE及免疫组织化学染色并观察分析。结果:原发性甲状腺鳞状细胞癌的病理分级多属鳞癌I~II级;免疫组织化学染色:CD44V6、CK在原发灶及淋巴结转移灶内肿瘤细胞均呈强阳性表达,而甲状腺球蛋白(TG)呈弱阳性表达。结论:原发性甲状腺鳞状细胞癌恶性程度高。CD44V6的高表达与原发性甲状腺鳞状细胞癌的侵袭转移密切相关,免疫组织化学TG标记对鉴别诊断有帮助。