我国河南汉族正常人群凝血因子VII基因MspⅠ多态性观察

目的 研究我国汉族正常人群凝血因子Vll基因MspI多态性的分布特点.方法 利用聚合酶链反应-限制性内切酶片段长度多态性(PCR-RFLP)技术,分析560名河南汉族正常人群凝血因子VII(FVII)基因R353Q突变的分布情况.结果 我国河南汉族正常人群FVII基因R353Q的RR,RQ,QQ,基因型频率分别是0.864,0.132,0.004;R,Q等位基因频率分别是0.930,0.070;与国外其他种族相比,基因型及等位基因频率与日本人差异无统计学意义(χ2=2.475,P＞0.05χ2=0.000,P＞0.05);RQ及QQ基因型明显低于意大利人,差异具有统计学意义(χ2=38.536,P＜0.01;χ2=16.311,P＜0.01);Q等位基因明显低于意大利人,差异具有统计学意义(χ2=50.228,P＜0.01).结论 我国河南汉族正常人群FVII基因R353Q突变的基因型分布不同于国外其它种族,具有种族或地域的差异.     

AMPK as a metabolic switch in rat muscle,liver and adipose tissue after exercise

An increasing body of evidence has revealed that activation of adenosine monophosphate (AMP)‐activated protein kinase (AMPK)‐activated protein kinase increases fatty acid oxidation by lowering the concentration of malonyl coenzyme A (CoA), an inhibitor of carnitine palmitoyl transferase 1. Studies carried out primarily in skeletal muscle suggest that AMPK modulates the concentration of malonyl CoA by concurrently phosphorylating and inhibiting acetyl CoA carboxylase (ACC), the rate limiting enzyme in malonyl CoA synthesis, and phosphorylating and activating malonyl CoA decarboxylase (MCD), an enzyme involved in its degradation. We have recently observed that AMPK and MCD activities are increased and ACC activity diminished in skeletal muscle, liver and, surprisingly, in adipose tissue 30 min following exercise (treadmill run) in normal rats. In liver and adipose tissue these changes were associated with a decrease in the activity of glycerol‐3‐phosphate acyltransferase (GPAT), which catalyses the first committed reaction in glycerolipid synthesis and, which like ACC, is phosphorylated and inhibited by AMPK. Similar changes in ACC, MCD and GPAT were observed following the administration of 5‐aminoimidazole 4‐carboxamide‐riboside (AICAR), further indicating that the exercise‐induced alterations in these enzymes were AMPK‐mediated. Conclusions: (1) AMPK plays a major role in regulating lipid metabolism in multiple tissues following exercise. (2) The net effect of its activation is to increase fatty acid oxidation and diminish glycerolipid synthesis. (3) The relevance of these findings to the regulation of muscle glycogen repletion in the post‐exercise state and to the demonstrated ability of AMPK activation to decrease adiposity and increase insulin sensitivity in rodents remains to be determined.     

Atypical respiratory pathogens

The main atypical pathogens in respiratory tract infections are classified on the basis of their ability to cause atypical pneumonia. This is not a well-defined clinical entity, and it is evident that atypical pathogens can sometimes cause 'typical' pneumonias and vice versa. This emphasizes the need for microbiological diagnosis, since it affects the selection of proper treatment, in which β-lactam antibiotics and aminoglycosides are not effective. Moreover, mixed infections caused by atypical and typical pathogens together are common. At this moment rapid and sensitive diagnostic methods are lacking. Besides numerous viruses, the main bacterial pathogens causing atypical pneumonias are Mycoplasma pneumoniae , two chlamydia species. Chlamydia pneumoniae and C. psittaci , one rickettsia, Coxiella burnetti , and several Legionella species. The majority of these pathogens cause upper respiratory tract infections more often than overt pneumonias. An atypical agent, Chlamydia pneumoniae , has also been associated with chronic inflammatory conditions in the cardiovascular system. The most recently discovered pathogen in atypical pneumonias is a hantavirus causing hantavirus pulmonary syndrome.     

SLEEP CYCLES AND SKIN POTENTIAL IN NEWBORNS STUDIED WITH A SIMPLIFIED OBSERVATION AND RECORDING SYSTEM

A simple visual observation system, supplemented by measurement of skin potential, was devised for developmental studies of sleep cycles in settings where multiple electrode placement is not practicable. The findings replicated essential features of quiet and active sleep cycles which had been reported previously to exist against the background of decreasing level of physiological arousal, as sleep proceeds. Twelve newborns showed approximately one-half of their inter-feeding sleeping time in the rapid eye movement stage of sleep. Skin potential rapidly declined from the waking level, continued to decrease in level throughout sleep, increased in variability during REM sleep, and increased in level at the second waking period.     

Positive correlation between aortic valve pressure gradient and mitochondrial respiratory chain capacity in hypertrophied human left ventricle

Summary The effect of chronic left ventricular pressure overload on the activities of mitochondrial respiratory chain enzymes was investigated in myocardial biopsies from the left ventricular apex of 13 patients undergoing aortic valve replacement for aortic valve stenosis. Transvalvular pressure gradients measured by left-sided heart catheterization ranged from 52 to 100 mmHg. The specific activity of mitochondrial respiratory chain enzyme complexes I + III (antimycin A sensitive NADH cytochrome c oxidoreductase) and the myocardial concentrations of coenzyme Q₁₀ (CoQ₁₀) increased significantly (P < 0.05) with increasing aortic valve pressure gradient. In contrast, the specific activities of complex IV (cytochrome c oxidase), succinate dehydrogenase, and citrate synthase, a mitochondrial matrix enzyme, showed no significant correlation with the pressure gradient. Since (CoQ₁₀) is the rate-limiting compound of the activity of complexes 1+111 but not of cytochrome c oxidase, succinate dehydrogenase, or citrate synthase, these data suggest that the increase in the activity of complexes I+III is due to the increase in (CoQ₁₀) content.Abbreviations CoQ coenzyme Q - CoQ₉ coenzyme Q₉ - CoQ₁₀ coenzyme Q₁₀ - SDH succinate dehydrogenase - NCP noncollagen protein     

Oxidative stress and sleep apnoea in clinically healthy infants in the first year of life

Summary Question of the study   Respiratory instability as well as tissue damage by free radicals (oxidative stress) have been hypothesized to play a role in cases of sudden and unexpected infant death in the first year of life. The ratio of the oxidized/reduced form of redox compounds in the circulation could be used as a marker of oxidative stress. Therefore, the sleep apnoea rate and redox status of coenzyme Q10 (CoQ10) (percentage of the oxidized form in total CoQ10) were measured in a population of clinically healthy infants in their first year of life in order to study whether a physiological parameter of respiratory instability is related to a biochemical parameter of oxidative stress. Patients and methods   Between May and December 1999, 323 infants in the first year of life were referred to a paediatric sleep laboratory. Sleep apnoea rate, periodic breathing and parameters of oxygenation (SaO₂ and TcPO₂) were calculated based on polysomnographic recordings. The CoQ10 redox status was calculated based on high-pressure liquid chromatographic (HPLC) analysis. Results   Statistical analysis showed an age-dependent decrease in apnoea rate ( r = – 0.38) and CoQ10 redox status ( r = – 0.40). An increased CoQ10 redox status (median: 16.6 %; range: 7.3 – 29.7 %) was found in infants with high apnoea rates above the 90^th percentile of a reference group in comparison with infants with apnoea rates below the 90^th percentile of a reference group (median: 10.4 %; range: 5.1 – 20.4 %; P = 0.031). Conclusions   These findings may indicate that high apnoea rates are accompanied by increased formation of free radicals in clinically healthy infants in the first year of life.     

辅酶Q10对兔膈肌疲劳的作用

实验以膈肌肌电图（ＥＭＧｄｉ）及膈肌诱发电位为指标，观察辅助酶Ｑ１０对兔膈肌作用，发现：（１）复制膈肌疲劳（ＤＩＦ）后静脉注射ＣｏＱ１０ｍｇ／ｋｇ，对ＤＩＦ有治疗作用，（２）提前１静脉注射ＣｏＱ１０１０ｍｇ／ｋｇ预处理，对电致作膈肌有保护作用。     

Pericentric inversions of chromosome 4: report of a new family and review of the literature

A family was cytogenetically studied because of the birth of a male child with a multiple congenital anomaly pattern, in whom a dup (4q) recombinant was found. His phenotypically normal mother's karyotype showed an apparently balanced pericentric inversion in a chromosome 4. So as to analyze the occurrence of recombinants, the cytogenetic data from this family are compared with those of the 18 previously reported familial cases of pericentric inversions (PIs) of chromosome 4. The congenital anomalies observed in the child strongly suggest Wolf-Hirschhorn syndrome but some of his clinical features seem to be pathogenetically related to the presence of lymphedema during the intrauterine period. In the multiple congenital anomaly pattern observed in this patient, the lymphedema could be the consequence of the large 4q duplication. The review of chromosome 4 PIs with 4q duplication suggests that the q3 region should be examined when edema is detected prenatally.     

The effects of a 5-HT1 receptor ligand isapirone (TVX Q 7821) on 5-HT synthesis and the behavioural effects of 5-HT agonists in mice and rats

The effects of 2-(4-(4-(2-pyrimidinyl)-1-piperazinyl)-butyl)-1,2-benzoisothiazol-3(2H)one-1,1-dioxide hydrochloride (isapirone, TVX Q 7821), a putative 5-HT₁ receptor antagonist, has been studied on various models of 5-HT receptor sub-type function. In mice TVX Q 7821 produced a dose-dependent inhibition of the hypothermia induced by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) with an ED₅₀ of 5.3 mg/kg suggesting that TVX Q 7821 was an antagonist of the presynaptic (possibly somato-dendritic) 5-HT_1A receptor. TVX Q 7821 did not alter the locomotor response to the suggested 5-HT_1B agonist RU 24969. The rate of mouse brain 5-HT synthesis was accelerated by TVX Q 7821 (10 mg/kg). 5-HT₂ receptor-mediated head twitch behaviour induced by precursor loading with 5-HTP was unaffected by TVX Q 7821 (10 mg/kg) pretreatment 75 min earlier, but the head-twitch induced by the agonist 5-methoxy-N,N-dimethyltryptamine was enhanced by prior treatment with TVX Q 7821.In rats the hypothermia induced by 8-OH-DPAT was partially antagonised by TVX Q 7821 while the behavioural serotonin syndrome induced by 8-OH-DPAT (a possible post-synaptic 5-HT_1B-mediated effect) was unaffected by TVX Q 7821 as was the locomotion induced by RU 24969.The data suggest that TVX Q 7821 is a good presynaptic 5-HT_1A antagonist in mice, as indicated by the 8-OH-DPAT-induced hypothermia and 5-HT synthesis rate studies. It did not antagonise 5-HT_1B-mediated behaviour in mice or rats and appeared to have an antagonist action at pre- but not post-synaptic 5-HT_1A receptors in rats. Offprint requests to: G.M. Goodwin