乳酸左氧氟沙星片的生物等效性研究

目的：建立人血浆中乳酸左氧氟沙星的HPLC-MS测定方法,研究乳酸左氧氟沙星在正常人体内的药代动力学行为,评价我公司生产的乳酸左氧氟沙星片与上市产品来立信的生物等效性。方法：人体实验采用双交叉设计,22名健康受试者交叉口服两个厂家生产的乳酸左氧氟沙星片,服药后0.33h～24h内间隔取血,用HPLC-MS法测血浆中的左氧氟沙星浓度,计算主要药动学参数,以上市样品为参比制剂,估算我公司生产的样品的相对生物利用度,判断生物等效性。结果：我公司研制的乳酸左氧氟沙星片相对生物利用度为108.1%～123.3%。结论：本实验建立的分析方法灵敏、准确、简便,统计学结果表明两种制剂生物等效。     

1,2-二氯乙烷对大鼠肝细胞内游离钙离子浓度的影响

目的了解1，2-二氯乙烷染毒24h对大鼠肝细胞的损伤及其机理。方法运用显微荧光术测定了大鼠肝细胞内游离钙离子浓度，同时，测定了大鼠肝细胞培养上清液乳酸脱氢酶（LDH）活力作为大鼠肝细胞受损的指标。结果所有剂量组的1，2-二氯乙烷的大鼠肝细胞内游离钙离子浓度与对照组比较差异均无显著性（P〉0．05）；LDH活力仅在浓度为5mmol／L的1，2-二氯乙烷染毒组与对照组比较差异也无显著性（P〉0．05）；而1，2-二氯乙烷其他染毒组（即浓度为10mmol／L和20mmol／L）与对照组比较差异均有显著性（P〈0．01）。结论较高浓度（10mmol／L和20mmol／L）的1，2-二氯乙烷能损伤大鼠肝细胞，损伤的途径不是通过破坏肝细胞内钙稳态机制。     

Basal levels of metabolic activity are elevated in Genetic Absence Epilepsy Rats from Strasbourg (GAERS): measurement of regional activity of cytochrome oxidase and lactate dehydrogenase by histochemistry

The Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are considered an isomorphic, predictive, and homologous model of human generalized absence epilepsy. It is characterized by the expression of spike-and-wave discharges in the thalamus and cortex. In this strain, basal regional rates of cerebral glucose utilization measured by the quantitative autoradiographic [(14)C]2-deoxyglucose technique display a widespread consistent increase compared to a selected strain of genetically nonepileptic rats (NE). In order to verify whether these high rates of glucose metabolism are paralleled by elevated activities of the enzymes of the glycolytic and tricarboxylic acid cycle pathways, we measured by histochemistry the regional activity of the two key enzymes of glucose metabolism, lactate dehydrogenase (LDH) for the anaerobic pathway and cytochrome oxidase (CO) for the aerobic pathway coupled to oxidative phosphorylation. CO and LDH activities were significantly higher in GAERS than in NE rats in 24 and 28 of the 30 brain regions studied, respectively. The differences in CO and LDH activity between both strains were widespread, affected all brain systems studied, and ranged from 12 to 63%. The data of the present study confirm the generalized increase in cerebral glucose metabolism in GAERS, occurring both at the glycolytic and at the oxidative step. However, they still do not allow us to understand why the ubiquitous mutation(s) generates spike-and-wave discharges only in the thalamocortical circuit.     

疟原虫乳酸脱氢酶Mab在疟疾诊断和疗效考核上的应用

目的评估疟疾乳酸脱氢酶单克隆抗体快速检测试剂在疟疾诊断和鉴别诊断上的特异性和敏感性以及考核疟疾治疗效果。方法使用OptiMal—IT金标层析快速检测试剂诊断和鉴别诊断间日疟57例，恶性疟5例；用传统的厚薄血片进行病原学对比诊断。同时用OptiMal—IT金标层析法考核治疗效果。结果OptiMal—IT金标层析法与病原学诊断间日疟和恶性疟原虫虫的符合率为100％，疟原虫患者治疗后3d OptiMal—IT金标层析法检测为阴性。结论OptiMal—IT金标层析法是一种快速、简便、特异性强、敏感性高的疟疾诊断和鉴别诊断试剂，可以用于快速应急检测，同时疟疾患者治疗后，若患者体内无活的疟原虫，OptiMal—IT金标层析为阴性，提示疟疾乳酸脱氢酶单克隆抗体OptiMal—IT金标层析可现场应用于疟疾快速诊断和疟疾治疗效果考核。     

二月桂酸二丁基锡(DBTD)对雄性大鼠睾丸组织中酶活性的影响

目的探讨二月桂酸二丁基锡(DBTD)对雄性大鼠生殖系统的影响。方法将健康成年Wistar雄性大鼠28只,体重(260±10)g,随机分为4组,即0、5、102、0 mg/kg剂量组,每组7只。灌胃染毒5周,末次染毒后48 h处死动物。结果与对照组相比,各剂量组大鼠睾丸中锡含量差异无显著性(P>0.05),而乳酸脱氢酶(LDH),氧化氮(NO)各剂量组,一氧化氮合酶(NOS)及酸性磷酸酶(ACP)中高剂量组与对照组差异都有显著性。结论DBTD具有睾丸毒性,能干扰雄性大鼠睾丸组织中酶的活性。     

豚鼠耳蜗毛细胞暴露非聚焦超声后的酶组织化学观察

目的　探讨非聚焦超声 (non focusedultrasound ,NFU)对耳蜗毛细胞的影响。方法　以A型超声波诊断仪为超声发射器 ,分别以 2 5MHz、8MHz照射各 15耳豚鼠耳蜗 6h后 30min和 8h行耳蜗基底膜毛细胞铺片及冰冻切片观察琥珀酸脱氢酶 (succinatedehydrogenase ,SDH)组织化学变化。结果　 2 5MHz、8MHzNFU照射豚鼠耳蜗 6h后 8h能引起不同节段基底膜毛细胞SDH酶活性降低 ,其中外毛细胞较内毛细胞SDH酶活性降低更甚。照射后 8h组较照射后 30min组SDH酶活性有明显恢复。结论不同频率NFU超声照射耳蜗达一定剂量可以引起不同部位基底膜毛细胞的病理性缺氧改变 ,而这种缺氧病理改变在一定暴露剂量下是可逆或部分可逆的。提示耳蜗毛细胞可能与超声感受有关 ,其中外毛细胞可能起更为重要的作用 ,且不同部位毛细胞与超声感受的频率选择性可能有一定关系     

Zur Enzymdiagnostik im Harn bei Kindern

Zusammenfassung Aus stationär aufgenommenen Kindern wurden 64 Patienten im Alter von 4 Tagen bis zu 13 Jahren randomisiert ausgewählt. Im Rahmen der Erstuntersuchungen wurden die Ausscheidung der Lactatdehydrogenase (LDH), alkalischen Phosphatase (AP) und der Leucinarylamidase (sogenannte Leucinaminopeptidase, LAP) im 8 Std-Nachtharn untersucht. Die Aktivitätsbestimmungen erfolgten in modifizierten Standardverfahren im Mikrolitersystem; der Sammlung, Vorbereitung und Aufarbeitung der Harne wurde besonderes Augenmerk geschenkt.Aus Patienten mit banalen, nichtentzündlichen Erkrankungen, ohne Fieber und ohne erhöhte Proteinausscheidung im Harn wurde ein Grundkollektiv von 18 Kindern gebildet. Bei diesem Kollektiv betrug die Ausscheidung, , für die LDH 2515±1838 mU/Std, für die AP 255±107 mU/8 Std und für die LAP 310±169 mU/8 Std. Mit zunehmendem Alter steigt die Ausscheidung der LDH von 1359 über 1531 und 2534 auf 4397 mU/8 Std an. Dagegen bleibt die Gesamtausscheidung der AP und LAP in diesem Alterszeitraum gleich. Bei allen Altersstufen ist die Ausscheidung der LDH dem Harnvolumen streng direkt proportional, r=0,95), nicht hingegen die der AP und LAP. Geschlechtsunterschiede sind bei allen drei Enzymen nicht festzustellen.Bei dem Krankenkollektiv bestehen auch bei unseren Kindern keine Zusammenhänge zwischen dem Bakteriengehalt und der proteinkonzentration und-ausscheidung einerseits und dem Ausmaß der Enzymurie andererseits. Dagegen wird Fieber über 38,6° C regelmäßig begleitet von hohen und höchsten Enzymausscheidungen bei AP und LAP; im Gegensatz dazu bleibt die LDH unauffällig. Umgekehrt bedeutet eine Enzymurie keinen Hinweis auf eine fieberhafte Erkrankung.Bei unseren Patienten mit Harnwegsinfekten und Nierenerkrankungen finden wir keine erhöhten Ausscheidungen der LDH, AP und LAP. Affallend ist die hohe Korrelation zwischen entzündlichen Allgemeinerkrankungen, insbesondere Entzündungen der Atemwege und des Magen-Darm-Traktes und der Ausscheidung der LAP, teilweise der AP. Zwischen Virusinfektionen und erhöhten Enzymausscheidungen scheinen keine Beziehungen zu bestehen.Die bisherigen Vorstellungen über die Mechanismen der pathologischen Enzymurie scheinen auf Grund des unterschiedlichen Verhaltens von LDH, AP und LAP einerseits, der verschiedenartigen Korrelation dieser Enzyme zu verschiedenen Krankheitstypen andererseits revisionsbedürftig. Weiterhin sollte gerade bei Kindern an Hand der vorgelegten Befunde der Versuch einer enzymatischen urinären Verlaufskontrolle von schweren Krankheitsbildern an größeren Fallzahlen durchgeführt werden. Ausgangspunkt hierfür sind die beobachteten normalen und schwerst pathologischen Enzymausscheidungen bei Pneumonien, Meningitiden und Leucosen.

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Diagnosis by means of enzymes in the urine of children

Sixty-four children aged from 4 days to 13 years were selected randomly amongst clinic patients. Parallel to primary examinations the urinary excretions of the enzymes lactate dehydrogenase (LDH), alkaline phosphatase (AP) and leucine aminopeptidase (LAP) during an eight-hour night period were measured. The determinations of activity were performed by modified standard methods in the microliter scale. Special attention was given to the collection and preparation of the urine samples. A group of 18 children with trivial diseases, with no signs of inflammatory processes, fever, or increased excretion of protein was formed. This group was used as a normal collective. The figures for the excretion of enzymes were as follows : 2515±1838 (LDH), 255±107 (AP) and 310±169 (LAP) mU/8 hrs. The excretion of LDH increased with advancing age, starting from 1359 to 1531, 2534 and 4397 mU/8 hrs. In contrast to these figures the total excretion of AP and LAP remains unchanged. At every age the excretion of LDH was closely correlated with the volume of the urine (coefficient of correlation r=0.95); there was no correlation with the excretion of AP and LAP. Nor did there seem to be any sex-dependent differentiation. In no case was any correlation found between the content of bacteria or proteins and that of enzymes in the urine. Elevated temperatures (38.6°C) were regularly accompanied by high values for the excretion of AP and LAP. Correlation between excretion of LAP, and, in some cases, of AP and general inflammatory diseases especially diseases of the respiratory and intestinal tracts was remarkably close. There did not appear to be any correlation will viral infections or — in our patients — to urogenital infections or kidney diseases. The hitherto genrally accepted conception of the mechanism of pathological excretion of enzymes seems to require a revision if one considers the different behaviour of LDH, AP and LAP.

     

Lactate accumulation following concussive brain injury: the role of ionic fluxes induced by excitatory amino acids

During the first few minutes following traumatic brain injury, cells are exposed to an indiscriminate release of glutamate from nerve terminals resulting in a massive ionic flux (e.g., K⁺ efflux) via stimulation of excitatory amino acid (EAA)-coupled ion channels. The present study was undertaken to elucidate the causal relationship between these ionic shifts and lactate accumulation in the injured brain, by examining the effects of ouabain (an inhibitor of Na⁺/K⁺-ATPase), Ba²⁺ (an inhibitor of non-energy-dependent glial K⁺ uptake) and kynurenic acid (KYN; a broad-spectrum EAA antagonist) on lactate accumulation. Two microdialysis probes were placed bilaterally in the rat parietal cortex. One was perfused with a test drug (1.0 mM ouabain, 2.0 mM Ba²⁺ or 10 mM KYN) and the other with Ringer's solution (control) for 30 min prior to injury. Following a 2.2–2.7 atm fluid-percussion injury, lactate levels in the dialysate increased (up to 116.6% above baseline) for the first 16 min and returned to baseline levels within 20 min after injury. This lactate accumulation was attenuated by preinjury administration of ouabain and KYN and was prolonged by Ba²⁺ administration. These findings indicate that lactate accumulation following concussive brain injury is a result of increased glycolysis which supports ion-pumping mechanisms, thereby, restoring the ionic balance which was disrupted by stimulation of EAA-coupled ion channels.     

Metabolic changes in patients with mitochondrial myopathies and effects of coenzyme Q10 therapy

We used a standardized bicycle ergometry protocol with a stepwise increasing workload (30–100 W) to evaluate various metabolic factors for the diagnosis and metabolic monitoring of mitochondrial encephalomyopathies. All patients (n = 9) showed pathological venous lactate/pyruvate (L/P) ratios, which normalized in three patients after 6 months of coenzyme Q₁₀ (CoQ) therapy. Thus, the L/P ratio proved to be the clinically most useful parameter in the evaluation and monitoring of mitochondrial diseases, showing higher sensitivity than lactate measurements only. CoQ may exert a favourable effect in some patients with mitochondrial diseases. Received: 15 October 1997 Received in revised form: 6 February 1998 Accepted: 20 March 1998     

Increase in plasma lactate at the menopause and its relation to the "anion gap"

The mean plasma anion gap (Na + K + Ca + Mg)--(Cl + HCO3(-) + HPO4(2-) + protein), was significantly higher in post-menopausal women compared with pre-menopausal women (8.04 mEq/l compared with 7.03 mEq/l). This change was due, in part, to an increase in the plasma lactate concentration and to smaller increases in citrate and pyruvate concentrations. There were also changes in bicarbonate and chloride concentrations which suggested an increase pH of approximately 0.02 U. Together, these changes accounted for 46% of the increase in the "anion gap", leaving 54% unexplained. It is suggested that the rise in plasma lactate concentration may be due to mild alkalosis and that this change may account for the rise in plasma urate concentration which also occurs at the menopause.