冠状动脉起源于肺动脉的影像学研究

目的 探讨冠状动脉(简称冠脉)起源于肺动脉(ACAPA)影像学诊断方法的价值。方法 回顾性分析11例ACAPA的影像学表现。11例均行X线胸片、超声心动图(Echo)和心血管造影检查，其中1例行电子束CT(EBCT)检查。结果 10例为左冠脉起源于肺动脉，1例为右冠脉起源于肺动脉。11例胸片均未确诊，Echo诊断3例，EBCT诊断1例。心血管造影全部诊断正确，其中左冠脉异常起源者左冠脉均发自主肺动脉后窦或后壁，通过扩张的右冠脉藉侧支逆行充盈；右冠脉异常起源者右冠脉从主肺动脉右窦发出。手术与造影所见相同。3例前乳头肌缺血性纤维化，二尖瓣环扩大，前叶脱垂致二尖瓣关闭不全。结论 X线胸片诊断受限，Echo简便、无创，但操作技术及认知水平有待提高。心血管造影仍是术前确诊的“金标准”。     

五味子酚对氧自由基引起大鼠脑突触体和线粒体损伤的保护作用

以Fe²⁺-半胱氨酸(Cys)为氧自由基生成系统,在体外模仿脑出血或脑外伤引起的氧自由基损伤的模型,观察五味子酚是否对Fe²⁺-Cys引起的大鼠脑突触体和线粒体损伤有保护作用,以探讨Sal用于延缓衰老、防治某些神经系统疾病的可能性。结果显示,与Fe²⁺-Cys共温孵可使脑突触体和线粒体MDA生成量显著增加,线粒体ATPase活性下降。而预先加入Sal(10^{-6mol·L-1)可抑制MDA生成,防止线粒体ATPase活性降低。Sal对Fe2+-Cys引起的线粒体肿胀和膜流动性降低也有明显的保护作用,并能防止Fe2+-Cys所致线粒体和突触体形态的病理性损伤。结果提示,Sal对氧自由基引起的大鼠脑突触体和线粒体损伤有明显保护作用。}     

Renal function in relation to three candidate genes in a Chinese population

We recently found in a white population that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), -adducin (Gly460Trp), and aldosterone synthase (–344C/T) jointly influence renal function. We therefore investigated in a Chinese population the associations between the serum concentrations of creatinine and uric acid and these three genetic polymorphisms. We genotyped 471 ethnic Han Chinese subjects from 125 nuclear families recruited in northern China via random population sampling (75%) and at specialized hypertension clinics (25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. The participants were 39.7 years old and included 235 women (49.9%). The blood pressure measured at the subjects homes averaged 126/80 mmHg. Mean values were 71 µmol/l for serum creatinine, 111 ml min^–1 1.73 m^–2 for calculated creatinine clearance, and 236 µmol/l for serum uric acid. With adjustment for covariables, GEE analyses of single genes demonstrated that serum uric acid, but not serum creatinine, was positively associated with the ACE D allele. Serum uric acid concentrations were 15.8 µmol/l (95% confidence interval 3.3–28.2) and 25.7 µmol/l (11.1–40.2) higher in DD homozygotes than in ID and II subjects, respectively. Further GEE analyses of the three genes combined showed that the association between serum uric acid and the ACE polymorphism was confined to carriers of the -adducin Gly and/or aldosterone synthase C alleles. Sensitivity analyses in parents and offspring separately as well as QTDT analyses were confirmatory. Among 114 informative offspring carrying the -adducin Gly allele serum uric acid was significantly and positively associated with the transmission of the ACE D allele (=20.7 µmol/l). In conclusion, the present study extends our previous findings on the combined effects of the three candidate genes and supports the concept that these genetic polymorphisms jointly influence renal function.     

Distinct Pattern of Human Vδ/51 γδ/5 T Cells Recognizing MICA

γδ T cells represent one unique recognition pattern, the limited recognition, which distinguishes from the specific recognition for αβ T cells and pattern recognition for macrophages. Vδ1 γδT cell is the major subset of human γδT cells, which predominates in mucosal tissue including the intestinal epithelia. Presently, a few antigens that human Vδ1TCR can recognize have been identified. Among them, MHC class I chain-related molecules A （MICA） have been studied most intensively. Besides Vδ1TCR, MICA is also the ligand of NKG2D, a C-type lectin-like activating immunoreceptor. In human, only Vδ1 cells can simultaneously express both types of receptors of MICA while NK cells, αβ T cells and other subsets of γδT cells likewise express NKG2D. Although the precise mechanisms are still enigmatic, this distinct pattern of Vδ1 cells recognizing MICA predicts unique biological significance of Vδ1 cells in immune defense. Recent years, some progresses have been made in this issue. In this review we summarize the related reports and put forward some novel views based on our group＇s studies.     

Mitochondrial DNA polymorphisms in Yunnan nationalities in China

Nucleotide sequences of the D-loop region of human mitochondrial DNA from four Yunnan nationalities, Dai, Wa, Lahu, and Tibetan, were analyzed. Based on a comparison of 563-bp sequences in 99 people, 66 different sequence types were observed. Of these, 64 were unique to their respective populations, whereas only 2 types were shared between the Lahu and Wa nationalities. The D-loop sequence variation and phylogenetic analysis suggested that the 99 mtDNA lineages were classified into eight clusters in the phylogenetic tree. All lineages that had a 9-bp deletion in the COII/tRNA^Lys intergenic region appeared in one cluster in the D-loop tree, suggesting a single event of the deletion in the Yunnan nationalities studied. Genetic distances, based on net nucleotide diversities between populations including Han Chinese and mainland Japanese, revealed that the Dai, Wa, Lahu, and Han Chinese are closely related to each other, while Tibetan and mainland Japanese formed a single cluster. The bootstrap probabil-ity of separation between the Dai-Wa-Lahu-Chinese clade and the Tibetan-Japanese clade was 99%, indicating that there are at least two different origins among minority groups in Yunnan province. Although the genetic distance between Tibetan and Japanese within the clade is rather long, the results may shed light on the origins of mainland Japanese. Received: December 22, 2000 / Accepted: January 18, 2001