反相斑点杂交法对解脲脲原体分型的研究

目的研究以聚合酶链反应为基础的快速检测与鉴定解脲脲原体基因型的方法。方法选择2003年11月至2005年11月在中山大学附属第二医院门诊就诊的有外阴阴道炎症状和体征的患者601例,设为病例组,同期无自觉症状的正常体检人群306例,设为对照组,分别取宫颈分泌物待检测。将解脲脲原体不同基因型的特异探针固定在硝酸纤维素膜上,临床标本按常规方法提取解脲脲原体DNA,采用生物素标记的解脲脲原体特异通用引物PCR扩增DNA,然后分别与解脲脲原体不同基因型特异探针杂交、显色。结果病例组解脲脲原体阳性421例占70.0%,对照组解脲脲原体阳性126例占41.2%。病例组中单型别感染的U.parvum占65.4%,其中1型、3型、6型和14型分别占28.8%、43.3%、26.0%和1.9%,U.urealyticum占18.4%;对照组中单型别感染的U.parvum占79.3%,其中1型、3型、6型和14型分别占63.2%、21.1%、15.7%和0.0%,U.urealyticum占13.8%。18例阳性标本随机DNA测序鉴定,均为相应的解脲脲原体基因型。结论U.parvum群,尤其是其中的1、3、6型别是正常人群携带的可能性较大,U.urealyticum则有可能和1型起协同作用或独自导致疾病。用反相斑点杂交进行解脲脲原体基因分型,方法简单、实用,适用于临床。     

运用PCR 扩增技术检测解脲脲支原体生物群的临床应用

目的:探讨运用酶链聚合反应(PCR)技术检测泌尿生殖道解脲脲原体(Uu)的生物群,分析Uu生物群与临床症状的相关性。方法:以支原体16S rRNA保守区域基因为扩增靶序列设计引物,采用PCR方法扩增Uu 16S rRNA基因检测125例临床标本,并将检测结果与临床症状进行相关性分析。结果:PCR法检出Uu阳性率44.8%,其中35例Uu生物1群阳性,其中有16例有症状;27例Uu生物2群阳性,其中有18例有症状。Uu生物1群感染与症状的相关性无统计学差异(P>0.05),而Uu生物2群感染与症状相关性有统计学差异(P<0.05)。结论:PCR检测Uu 16S rRNA基因可用于Uu生物群的检测,Uu生物2群可能是非淋菌性尿道炎(NGU)的一个致病菌,而Uu生物1群与NGU无明显相关性。     

解脲脲原体分子生物学分群和分型

解脲脲原体(Uu)常寄居于人泌尿生殖道,可引起绒毛膜羊膜炎、新生儿脑膜炎,尿道炎等疾病,也可引起呼吸道疾病和死亡.研究表明,Uu的某个群或型与疾病相关,所以研究Uu的分群和分型方法对理解疾病的发病机制和临床治疗有重要作用.本文对Uu的分子生物学分群和分型方法作一综述.     

大学生解脲脲原体和人型支原体正常携带状况研究

目的探讨解脲脲原体(Uu)和人型支原体(Mh)在大学生中的正常携带状况.方法采用培养法对314名未婚统招大学生和232名已婚成教大学生进行解脲脲原体和人型支原体的检测.结果未婚大学生和已婚大学生泌尿生殖道支原体检出率分别为12.10%和22.41%,后者明显高于前者(x2=10.31,P＜0.005);已婚男、女大学生泌尿生殖道支原体检出率(分别为17.44%和27.78%)明显高于未婚男、女大学生检出率(分别为8.33%和16.44%,x2=5.84、4.77P＜0.05).未婚男、女大学生之间泌尿生殖道支原体检出率差异有显著性(y2=4.82,P＜0.05),而已婚男、女大学生之间泌尿生殖道支原体检出率差异无显著性(x2=3.34,P＞0.05).已婚和未婚大学生泌尿生殖道支原体检出者中均以同时携带Uu和Mh较为常见.结论在校大学生中也有一部分人正常携带Uu和/或Mh,从他(她)们体内检出Uu和/或Mh一般不代表疾病状态.     

PCR法检测正常女性宫颈中的溶脲脲原体生物群

目的了解正常妇女宫颈中溶脲脲原体两个生物群的分布及药物敏感性。方法采用PCR技术对妇科门诊的正常妇女宫颈的溶脲脲原体两个生物群进行检测。结果50例正常妇女经PCR-CE检测,21例(42.0%)溶脲脲原体阳性其中溶脲脲原体生物群1阳性16例(76.2%),生物群2阳性5例(23.8%)。结论溶脲脲原体生物群1可能是女性生殖道一种正常菌群。而溶脲脲原体生物群2能引起妇科疾病从而导致不孕。     

大学生尿沉渣中解脲脲原体和人型支原体感染情况分析

目的了解解脲脲原体(Ureaplasma urealytium,Uu)和人型支原体(Mycoplasma homanis,Mh)在大学生泌尿道中的感染情况.方法采用培养方法对37例正常的在校大学生的尿沉渣进行Uu和Mh的培养.结果采用培养方法检测21.6%(8/37)的大学生Uu感染为阳性,其中分离阳性者全部是女生(8/20,40%),13.50%(5/37)大学生Mh培养为阳性,其中阳性者亦全部为女生,占女生人数的25%(5/20).结论Uu和Mh可能是女性泌尿道的正常寄生的微生物之一.     

女性泌尿生殖道支原体感染及耐药性观察

目的了解女性泌尿生殖道感染患者解脲支原体(Uu)和人支原体(Mh)感染及耐药情况,指导临床合理应用抗菌药物。方法采用法国梅里埃公司生产的IST2支原体培养及药敏试剂盒,对932例女性泌尿生殖道感染患者进行培养及药敏试验。结果 932例患者中支原体阳性426例,总检出率45.7%,其中Uu阳性354例(37.9%),Mh阳性14例(1.5%),Uu+Mh阳性58例(6.2%);药敏结果表明,Uu与Mh对多西环素、交沙霉素、四环素较为敏感,Uu对环丙沙星、氧氟沙星耐药率较高,而Mh对克拉霉素、红霉素、阿奇霉素耐药率较高。结论女性泌尿生殖道支原体检出率较高,主要以Uu为主,Uu和Mh对多种抗菌药物耐药,应引起临床重视。     

泌尿生殖道支原体感染检测及药敏试验

目的了解本地区泌尿生殖道解脲脲原体（Uu）和人型支原体（Mh）感染状况及药物敏感性,指导临床医生合理应用抗生素。方法应用法国生物梅里埃公司提供的IST试剂盒进行支原体鉴定及9种药物敏感检测,并对结果进行统计分析。结果1210例门诊患者检出支原体阳性683例,总感染率为56.4%,其中Uu单独感染占628例（占51.9%）,Mh单独感染14例（占1.2%）,Uu和Mh混合感染41例（占3.4%）。交沙霉素和原始霉素敏感率最高,对Uu分别为98.5%和97.0%,对Uu和Mh混合感染率都为100%;氧氟沙星敏感率最低,分别为1.5%和0.0%。结论泌尿生殖道系统感染主要由解脲支原体引起,交沙霉素和原始霉素敏感率最高,氧氟沙星敏感率最低。临床应选用培养敏感的抗菌药物,提高治疗效果。     

产后子宫内膜炎与围生期解脲脲原体感染有关

为了探讨围生期支原体感染与产后子宫内膜炎的关系及治疗,本研究选取产后子宫内膜炎患者73例作为观察组,同时选取正常产妇80例作为对照组。通过检测两组解脲脲原体(Uu)和人型支原体(Mh)感染情况,同时给予观察组常规治疗,本研究发现观察组Uu阳性比例为32.88%,明显高于对照组(p<0.05);观察组和对照组Mh阳性差异比较无统计学意义(p>0.05);观察组Uu阳性和Mh阳性产妇发生早产或胎膜早破的比例分别为62.50%和25.00%,明显高于支原体感染阴性产妇(p<0.05);观察组Uu阳性、Mh阳性和阴性患者治疗效果比较差异无统计学意义(p>0.05);观察组治疗后Uu阳性率为10.96%,明显较治疗前降低(p<0.05);观察组治疗前后Mh阳性率比较差异不显著(p>0.05)。本研究表明,Uu感染与产后子宫内膜炎发生有一定关系,围生期应加强Uu感染筛查,并及时进行治疗。     

1796例泌尿生殖道支原体培养及药敏结果分析

目的分析新乡地区1796例泌尿生殖道标本的支原体培养及抗生素药物敏感试验,指导临床合理使用抗生素。方法支原体培养鉴定、药敏试剂盒购自贝瑞特公司。同时检测解脲支原体和人型支原体,并进行10种抗生素的药敏试验。数据统计采用χ^2检验。结果支原体培养1596例标本中,541例解脲脲原体（Uu）阳性,阳性率为33.9%;39例人型支原体（Mh）阳性,阳性率为2.4%;解脲脲原体、人型支原体均阳性76例,阳性率为4.8%。200例正常对照组27例阳性,阳性率为13.5%。药敏结果显示,强力霉素、克拉霉素和美满霉素的抗菌活性较强。结论支原体感染以Uu为主,Uu＋Mh次之,正常人泌尿生殖道支原体阳性率为13.5%。只有某些血清型感染且在达到一定浓度以上同时宿主处于多种病原体感染或免疫机制紊乱时,Uu才能致病。避免滥用抗生素引起生殖道菌群失调。临床上治疗Uu感染、Mh感染或Uu＋Mh混合感染时,建议选用强力霉素、克拉霉素和美满霉素。     

Race and Racism in America and in Anthropology

Race in North America: Origin and Evolution of a Worldview . Audrey Smedley
Anthropology and Race . Eugenia Shanklin     

Degradation and conversion of somatostatin in normal and diabetic rats in vivo and in vitro

Plasma somatostatin-like immunoreactivity in the portal and jugular veins of streptozotocin diabetic rats was compared with that in normal control rats. In the diabetic group, somatostatin levels in the portal (p less than 0.05) and jugular (p less than 0.01) veins were both elevated compared with those in the control group. Moreover, the degree of elevation was greater in the jugular vein than in the portal vein. To further investigate the role of the liver in the clearance of somatostatin-28 in vivo, 2 micrograms of somatostatin-28 was administered as a bolus into the external jugular vein of intact and functionally hepatectomized rats. The mean half-time of somatostatin-28 was significantly longer in intact diabetic rats than in controls (p less than 0.05). The functional hepatectomy did not cause a significant difference in the half-time in diabetic rats but made it longer in control rats. These results suggest that the longer half-time of somatostatin-28 in diabetic rats in vivo is due to its slower hepatic clearance. The hepatic clearance of somatostatin-28 and somatostatin-14 was further studied in vitro using a recirculating liver perfusion method. The hepatic clearance of 1.2 nM of either somatostatin-28 or somatostatin-14 was significantly lower in diabetic rats than in controls (p less than 0.01). This indicates that elevated plasma somatostatin levels in diabetic rats are caused at least in part by decreased hepatic clearance of somatostatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Electroejaculation in chimpanzees and gorillas and artificial insemination in chimpanzees

Electroejaculation was performed in 3 chimpanzees, 1 pygmy chimpanzee, and 2 gorillas with an instrument that delivers a modified sine wave current with a frequency of 24 Hz. The current stimuli were applied by a rectal probe with longitudinal electrodes. The electrical parameters varied from 6 to 12 V and from 30 to 40 mA for response of erection and lay between 8 and 18 V and between 40 and 145 mA during semen emission. Eleven chimpanzee semen samples showed the following data (x ± SD): total volume 1.9 ± 1.3 ml, volume of the liquid fraction 0.3 ± 0.2 ml, spermatozoa per ejaculate 743 ± 376 × 10⁶, sperm motility 52.7 ± 9.6%, morphologically abnormal spermatozoa 12.2 ± 7.5%. From an adult gorilla, three semen samples were collected, in each case without spermatozoa. The electrostimulation of a 6-year-old gorilla led to an erection, but not to semen emission. Three female chimpanzees were inseminated with fresh or frozen semen, each of them within three different estrous cycles. None of these inseminations led to a pregnancy.     

Advances in purine and pyrimidine metabolism in health and diseases

ABSTRACT

In June, 2015, the Purine and Pyrimidine Society organized the 16th biennial symposium on Purine and Pyrimidine metabolism at the Faculty House of Columbia University, New York City. This exciting meeting focused on these important molecules, new developments in inborn errors of metabolism; therapeutic analogs. In addition, the biochemistry of mammalian and non-mammalian systems were discussed. Due to significant advances in molecular medicine, the boundaries between clinical and basic sciences have merged into exciting translational research, of which a small portion was highlighted in the presymposium.     

Trajectories and Constraints in Brain Evolution in Primates and Cetaceans

A negative allometric relationship between body mass (BM) and brain size (BS) can be observed for many vertebrate groups. In the past decades, researchers have proposed several hypotheses to explain this finding, but none is definitive and some are possibly not mutually exclusive. Certain species diverge markedly (positively or negatively) from the mean of the ratio BM/BS expected for a particular taxonomic group. It is possible to define encephalization quotient (EQ) as the ratio between the actual BS and the expected brain size. Several cetacean species show higher EQs compared to all primates, except modern humans. The process that led to big brains in primates and cetaceans produced different trajectories, as shown by the organizational differences observed in every encephalic district (e.g., the cortex). However, these two groups both convergently developed complex cognitive abilities. The comparative study on the trajectories through which the encephalization process has independently evolved in primates and cetaceans allows a critical appraisal of the causes, the time and the mode of quantitative and qualitative development of the brain in our species and in the hominid evolutionary lineage.     

Variation in infectivity and aggressiveness in space and time in wild host-pathogen systems: causes and consequences

Variation in host resistance and in the ability of pathogens to infect and grow (i.e. pathogenicity) is important as it provides the raw material for antagonistic (co)evolution and therefore underlies risks of disease spread, disease evolution and host shifts. Moreover, the distribution of this variation in space and time may inform us about the mode of coevolutionary selection (arms race vs. fluctuating selection dynamics) and the relative roles of G × G interactions, gene flow, selection and genetic drift in shaping coevolutionary processes. Although variation in host resistance has recently been reviewed, little is known about overall patterns in the frequency and scale of variation in pathogenicity, particularly in natural systems. Using 48 studies from 30 distinct host–pathogen systems, this review demonstrates that variation in pathogenicity is ubiquitous across multiple spatial and temporal scales. Quantitative analysis of a subset of extensively studied plant–pathogen systems shows that the magnitude of within‐population variation in pathogenicity is large relative to among‐population variation and that the distribution of pathogenicity partly mirrors the distribution of host resistance. At least part of the variation in pathogenicity found at a given spatial scale is adaptive, as evidenced by studies that have examined local adaptation at scales ranging from single hosts through metapopulations to entire continents and – to a lesser extent – by comparisons of pathogenicity with neutral genetic variation. Together, these results support coevolutionary selection through fluctuating selection dynamics. We end by outlining several promising directions for future research.     

MPD and DNA Bending in Crystals and in Solution

Bending of 15 to 24° is observed within crystal structures ofB-DNA duplexes, is strongly sequence-dependent, and exhibits no correlation with the concentration of MPD (2-methyl-2,4-pentanediol) in the crystallizing solution. Two types of bends are observed: facultative bends or flexible hinges at junctions between regions of G·C and A·T base-pairs, and a persistent and almost obligatory bend at the center of the sequence R-G-C-Y. Only A-tracts are characteristically straight and unbent in every crystal structure examined to date. A detailed examination of normal vector plots for individual strands of a double helix provides an explanation, in terms of the stacking properties of guanine and adenine bases. The effect of high MPD concentrations, in both solution and crystal, is to decrease local bending somewhat without removing it altogether. MPD gel retardation experiments provide no basis for choosing among the three models that seek to explain macroscopic curvature of DNA by means of microscopic bending: junction bending, bent A-tracts, or bent general- sequence DNA. Crystallographic data on the straightness of A-tracts, the bendability of non-A sequences, and the identity of inclination angles in A-tract and non-A-tractB-DNA support only the general-sequence bending model. The pre-melting transition observed in A-tract DNA probably represents a relaxation of stiff adenine stacks to a flexible conformation more typical of general-sequence DNA.