高原红细胞增多症患者红细胞二磷酸甘油酸和氧亲和力变化的探讨

在海拔４３００ｍ地区,对１８名移居汉族、２４名世居藏族和２１名高原红细胞增多症（ＨＡＰＣ）患者测定了２,３—二磷酸甘油酸（２,３—ＤＰＧ）和肺通气功能,并进行了血气分析。结果显示：ＨＡＰＣ患者的全血和红细胞内２,３—ＤＰ６浓度均显著高于健康组,但世居、移居健康组之间无明显差异。ＨＡＰＣ组的红细胞２,３—ＤＰＧ和Ｐｄｏ＿２呈显著负相关（ｒ＝—０．７７１,Ｐ＜０．０１）,而在健康组无显著相关（ｒ＝—０．２６,Ｐ＞０．０５）。ＨＡＰＣ组与健康组相比,ｐＨ、Ｐａｏ＿２和Ｓａｏ＿２降低,Ｐａｃｏ＿２和肺泡动脉氧分压差增高。ＨＡＰＣ病人Ｐ＿（５０）为３．７５±０．６６ｋＰａ,健康组为３．４０±０．１２ｋＰａ（Ｐ＜０．０５）,Ｐ＿（５０）与２,３－ＤＰＧ呈正相关（ｒ＝０．５９２,Ｐ＜０．０５）。ＨＡＰＣ组最大呼气中段流量和５０％肺活量最大呼气量明显低于健康组（Ｐ＜０．０１）。本研究提示：①ＨＡＰＣ患者的低氧血症可能与血中２,３－ＤＰＧ浓度过高有关;②轻度肺功能异常亦可促使红细胞进一步增多。     

听觉声损伤与耳蜗鼓阶淋巴氧分压的关系

本实验运用极谱式氧电极研究了噪声暴露对耳蜗鼓阶淋巴氧分压（ＳＴＰＯ２）的影响以及ＳＴＰＯ２的变化与听觉电生理、毛细胞损伤之间的关系。结果表明：（１）８５ｄＢＳＰＬ以上声刺激时ＳＴＰＯ２迅速降低;８５ｄＢＳＰＬ窄带噪声暴露时ＳＴＰ０２与血压一同缓慢增高;低于８５ｄＢＳＰＬ的声刺激则未能引起ＳＴＰ０２和血压的改变。（２）ＳＴＰＯ２降低约２０％即伴随明显的听损伤;ＳＴＰＯ２的变化程度与声暴露量（ｒ＝０．９７,Ｐ＜０．０５）、听力损失（ｒ＝０．８２,Ｐ＜０．０５）呈相关;与耳蜗病理改变也有一定关系,但与血压无明显相关性（ｒ＝０．２１,Ｐ＞０．２）。（３）声暴露时,吸入碳氧混合气对听力损失具有部分保护作用。     

维生素A缺乏胎鼠作为先天性心脏病动物模型的实验研究

目的　探讨将维生素Ａ缺乏（ＶＡＤ）胎鼠作为先天性心脏病动物模型的可行性。方法取１１－１９ｄ不同胎龄正常及ＶＡＤ胎鼠心脏经石蜡包埋、切片及 ＨＥ染色观察其发育情况。结果 １．实验组饲料含维生素Ａ（ＶＡ）７μｇ／１００ｇ,经ＶＡＤ饮食喂养后实验组大鼠血清ＶＡ水平明显低于对照组［（０．１６８±０．０５９）μｍｏｌ／Ｌ Ｖｓ（２．１８±０．２３）μｍｏｌ／Ｌ,ｔ＝３２．８８, Ｐ＜０．００１］。 ２．大鼠死亡百分比：饲养于屏障系统的ＶＡＤ大鼠死亡百分比较饲养于开放系统中的要低４．６倍（１０％ Ｖｓ ４５．８３％．ｘ ２＝１６．６４, Ｐ＜０．００１）,对照组为０。 ３．实验组大鼠受孕百分比及每只孕鼠产仔数均低于对照组［５８．３３％ Ｖｓ ８１．５％, ｘ ２＝４．３７,Ｐ＜０．０５：（６．９７±２．７９） Ｖｓ（１３ ±１．０５）,ｔ＝７．１６, Ｐ＜０．００１］。 ４．经切片观察１１～１５ ｄ胎龄胎鼠实验组心脏出现明显发育延迟的占３６．６７％, １６～１９ ｄ胎龄胎鼠实验组心脏畸形占４１．４３％,血管异常占１８．５７％。结论ＶＡＤ胎鼠可用来作为先天性心脏病动物模型,但需改进饲养环境以减少异常死亡。     

兽类的死亡率

本文共收集了３３种兽类的年均死亡率数据。求得陆生兽类的死亡率和体重的回归模型为： Ｄｔ＝０．６９５－０．０９７３ｌｎ Ｗｔ（ｒ２＝０．８６５,ｐ＜０．００１） Ｄｈ＝０．７３２－０．１００ｌｎ Ｗｈ（ｒ２＝０．８９１,ｐ＜０．００１） Ｄｃ＝０．６１９－０．０９０８ｌｎ Ｗｃ（ｒ２＝０．８６９,ｐ＜０．００１）这里,Ｄｔ、Ｄｈ和 Ｄｃ分别为陆生兽类、食植兽类和食肉兽类的年均死亡率;Ｗｔ、Ｗｈ和 Ｗｃ则分别是它们的体重（公斤）。研究发现：陆生兽类的体重决定了年均死亡率８６％以上的变异：食肉兽类比同样体重的食植兽类的年均死亡率小;飞行兽类比同样体重的陆生兽类的年均死亡率小。兽类死亡率的这一变异规律被认为和能量限制有关。     

完全失神经面瘫I／t曲线的对数相关性及预后

肌电图检测完全失神经面瘫３０例,同时检测患侧额肌、口轮匝肌Ｉ／ｔ曲线６０条,有扭结１９条,直线４１条。计算额肌、口轮匝肌Ｉ／ｔ曲线对数回归直线方程分别为：ＬｏｇＹ＝－０．６４ＬｏｇＸ＋０．９８（ｒ＝０．９９９６,Ｐ＜０．００１）和ＬｏｇＹ＝－０．７６ｌｏｇＸ＋０．８４（ｒ＝０．９９８９,Ｐ＜０．００１）。３０例患者随访１至３年,Ｈｏｕｓｅ－ＢｒａｃｈｍａｎｎⅠ级３例,２３例留有后遗症和并发症,Ⅲ级１０例,Ⅳ级１３例。出现面部明显运动时间病后２至５个月,手术损份４例未恢复。结论：完全失神经面瘫Ｉ／ｔ曲线,随脉宽减小,强度值呈直线上升;两条曲线的建立对于评定面瘫的神经损伤程度、预后及比较不同治疗方法优越性提供了依据。     

黑鲷的胃排空率

在实验室内,１８℃条件下测量了体重在２０－４０ｇ的黑鲷的胃排空率,并用３种数学模型拟合了黑鲷的排空率,结果表明,３种模型都能很好地拟合实验数据,但通过统计学分析发现不论是用湿重还是用于重表示胃含物,线性模型都拟合得最好。用湿重表示时模型为Ｙ＝１．１４－０．０６ｔ（ｒ＾２＝０．８２,ｐ〈０．００１）;而用干重表示时模型为Ｙ＝１．３６－０．０７Ｔ（ｒ＾２＝０．６２,ｐ〈０．００１）,实验还得出体重２０     

缺氧时培养的心内膜内皮细胞内皮素自分泌调节的探讨

本实验观察缺氧对心内膜内皮细胞（ＥＥＣ）内皮素－１（ＥＴ－１）分泌的影响。传代培养的新生小牛右心室ＥＥＣ的ＥＴ－１免疫组织化学显色强阳性。采用放免测定发现ＥＥＣ可向培养液中分泌ＥＴ－１,其分泌速度与细胞密度呈线性负相关（ｒ＝－０．９５４２,Ｐ＜０．００１）,与温育时间呈指数负相关（ｒ＝－０．９９８,Ｐ＜０．００１）。０％Ｏ２缺氧６～１２ｈ后,ＥＥＣ的ＥＴ－１分泌约增加１倍（Ｐ＜０．００１）。无论在常氧还是缺氧情况下,硝普钠抑制ＥＥＣ的ＥＴ－１分泌,而ＮＯ合酶抑制剂ＬＮＡ则促进ＥＴ－１分泌。上述结果表明：ＥＥＣ可能通过分泌ＥＴ－１调节心脏功能,内源性ＮＯ抑制ＥＴ－１分泌;缺氧可能显著影响ＥＥＣ的ＥＴ－１分泌     

不同pH值条件下利多卡因对淋巴细胞β受体的影响

用放射配基结合法和放免分析法测定了不同ｐＨ值下利多卡因对人血液淋巴细胞β受体结合和肾上腺素刺激的ｃＡＭＰ产量的影响。结果表明,ｐＨ值的增加有利于３Ｈ－ＤＨＡ与β受体结合,肾上腺素刺激的淋巴细胞ｃＡＭＰ的产量随ｐＨ值的增加而增加（Ｐ＜０．００１）;利多卡因抑制β受体结合和肾上腺素刺激的淋巴细胞ｃＡＭＰ产量,其抑制程度亦随ｐＨ值增加而增加（Ｐ＜０．００１）。提示心肺复苏期间不用利多卡因时β受体激动剂的效应随ｐＨ值的增加而增加,如同时使用利多卡因则β受体激动剂的效应并不随ｐＨ值的增加而增强,其机制可能与利多卡因随ｐＨ值的增加,改变了细胞膜脂质流动性,抑制β受体与激动剂的结合有关。     

高碳酸抑制兔离体基底动脉缺氧性收缩

在离休兔基底动脉观察了ＣＯ＿２浓度、ｐＨ值对血管缺氧反应的影响。在以５－羟色胺（５－ＨＴ,１０￣（－６）ｍｏｌ／Ｌ）预收缩后,缺氧使血管张力升高（Ｔ＿Ｈ）１１４．８７±４０．７５ｍｇ,其占总张力变化的百分数Ｔ（％）为４８．６２±１２．１１（ｎ＝５１）。去内皮对缺氧性收缩无影响。随浴槽液中ＣＯ＿２浓度增加,缺氧性收缩幅度减弱,在Ｐｃｏ＿２为８．００、９．３３和１０．６７ｋＰ８时,Ｔ（％）仅分别为３８．３０±５．３６（ｎ＝１１）、３２．２５±７．７６（ｎ＝１３）和２９．９０±９．２６（ｎ＝１１）,较对照值（Ｐｃｏ＿２＝５．３３ｋＰａ时）均有显著差异（Ｐ＜０．０１）。ｐＨ７．２－７．７时血管缺氧反应无显著变化。一氧化氮合成酶抑制剂Ｌ－ＮＮＡ（１０￣（－６）ｍｏｌ／Ｌ可抑制血管的缺氧收缩反应,也抑制了不同ＣＯ＿２浓度对缺氧反应的影响。结果提示ＣＯ＿２可能经促血管分泌一氧化氮的功能而抑制了缺氧性收缩。     

白水江自然保护区糙花箭竹天然林生物量与生产力的初步研究

本文根据样方上测定糙花箭竹的地径,茎高,密度,茎重,枝条重,叶重和鞭系重资料,研究竹林生物量和生产力,并建立回归数学模型为“茎重ＷＳ＝１６０．９４２＋０．２７７（Ｄ＾２ＮＨ） ｐ＜０．００１,枝条重ＷＢ＝７６．００８＋０．０３９（Ｄ＾２ＮＨ） ｐ＜０．００１,叶重ＷＬ＝８０．６４３＋０．０５１（Ｄ＾２ＮＨ） ｐ＜０．００１,鞭系重ＷＲ＝２８５．５５４＋０．０７４（Ｄ＾２ＮＨ） ｐ＜０．００１     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.