The measurement of amino groups in proteins and peptides

A technique is examined for determining amino groups with 2,4,6-trinitrobenzenesulphonic acid, in which the extinction at 420nm of sulphite complexes of the trinitrophenylated amino groups is measured. The sensitivity of the method is 5-200nmol of amino group. The method is especially suitable for checking the extent of blocking or unblocking of amino groups in proteins and peptides, owing to the short time required for reaction (5min at room temperature). The reaction of the reagent with thiol groups has been studied and was found to proceed 30-50 times faster than with in-amino groups of model compounds. The in(420) of a trinitrophenylated thiol group was found to be 2250m(-1).cm(-1). The reaction with several amino acids, peptides and proteins is presented. The in(420) of a typical alpha-amino group was found to be 22000m(-1).cm(-1) and that of an in-amino group, 19200m(-1).cm(-1). Difficulties inherent in the analysis of constituent amino group reactions in proteins are discussed.     

Immunologic memory to PC-KLH: participation of the Q52 VH gene family

BALB/c mice immunized with phosphocholine-conjugated keyhole limpet hemocyanin respond with two major groups of antibodies that differ with respect to fine specificity and idiotype. Group I antibodies predominantly bear the T15 idiotype, and show appreciable affinity for the haptens PC and nitrophenyl PC (NPPC), whereas group II antibodies have appreciable affinity for NPPC only and are T15 idiotype negative. Previous studies indicated that group II binding characteristics may derive from the use of novel V gene segments not observed in group I antibodies. To determine the nature of VH gene usage in the group II antibody response, we examined the VH region of a prototype group II hybridoma, PCG1-1. The nucleotide sequence obtained from the VDJ region indicates that PCG1-1 utilizes a VH gene not observed in the group I response, one that belongs to the Q52 VH family. The PCG1-1 VH nucleotide sequence shares 97% identity with the myeloma M141 VH gene. In addition, PCG1-1 utilizes a D segment most closely related to DSP2.6 rearranged to JH-3. These data indicate that M141, a VH gene not seen in group I anti-PC antibodies is utilized by PCG1-1 to generate a PC-protein-binding group II antibody. PCG1-1 was previously shown to express the V kappa 1-3 light chain, a characteristic shared by several group II hybridomas. Furthermore, here we examined the VH gene rearrangements in four lambda 1-bearing group II hybridomas that share a common JH rearrangement with PCG1-1 by Southern blot analysis. A VH-specific probe that detects M141 VH rearrangements revealed that all four lambda 1 hybridomas as well as PCG1-1 share an identical VH gene rearrangement to JH-3. Thus the M141 VH gene product is able to utilize two distinct light chains to generate group II-like combining sites.     

The effect of antibiotic treatment on the supercooling ability of the land snail Helix aspersa (Gastropoda: Pulmonata)

The land snail Helix aspersa is a partially freezing tolerant species whose supercooling ability is limited to ca. -3 to -5 degrees C. One hundred adult snails were subjected to the following two experimental conditions: (i) a starved group, provided with water; (ii) an antibiotic-treated group that was provided with a solution containing a mixture of two antibiotics. The antibiotic group exhibited a T(c) significantly lower than the starved group (-3.94 +/- 1.32 degrees C, n = 40 and -3.07 +/- 0.99, n = 30, t test, p < 0.005). This study showed that bacteria of the gut are likely to elevate animal supercooling points. It is also the first report in which a possible ice-nucleating activity of the gut microflora in a land snail has been suggested by the action of antibiotics on the T(c).     

The H- and T-reflex response parameters of long- and short-distance athletes

It is well known that the training level of a muscle belongs to the parameters that affect the H-reflex response amplitude. The aim of this study was to investigate the effects of training type on H- and T-reflex response parameters. For this purpose, 20 long-distance athletes (group I, test group), 18 short-distance athletes (group II, test group) and 20 non-trained subjects (group III, control group) were involved in this study in which the H- and T-reflex amplitude and latency values were measured. The H-reflex amplitude and latency values found in groups I, II and III were 3.64 +/- 0.28 mV and 26.88 +/- 1.45 ms, 3.17 +/- 0.26 mV and 26.19 +/- 1.89 ms, and 6.07 +/- 0.34 mV and 26.77 +/- 1.32 ms, respectively. The T-reflex amplitude and latency values of the groups I, II and III were 3.30 +/- 0.18 mV and 32.01 +/- 1.02 ms, 3.11 +/- 0.20 mV and 31.47 +/- 1.16 ms, 4.24 +/- 0.21 mV and 31.47 +/- 1.16 ms, respectively. There was no statistically significant difference between the groups with respect to latencies of H- and T-reflexes (p>0.05). In both test groups, the amplitudes of the H-reflex and T-reflex were significantly smaller than the control group (p<0.05). The results of this study suggest that training of muscles affect the H- and T-reflex response parameters.     

低氧预适应小鼠皮层Bcl-2和Caspase-3的表达变化

本文旨在探讨小鼠皮层Bcl-2和Caspase-3在低氧预适应脑保护中的作用.将Bib/c近交系小鼠随机分为对照组、低氧组和低氧预适应组,用免疫荧光和激光共聚焦显微镜等技术测定皮层顶叶Bcl-2和Caspase-3表达荧光强度和阳性细胞计数.结果显示,低氧组和低氧预适应组Bcl-2表达均显著高于对照组,低氧预适应组又显著高于低氧组.低氧组和低氧预适应组Caspase-3表达均显著高于对照组,但低氧预适应组显著低于低氧组.结果表明,低氧预适应过程中,小鼠皮层脑区通过Bcl-2高表达和Caspase-3低表达抵御皮层细胞凋亡,从而参与脑保护机制.     

血清25-羟维生素D水平与儿童骨密度的相关性研究

目的:研究血清25-羟维生素D[25-(OH)D]水平与儿童骨密度(BMD)的相关性。方法:选择2017年1月到2017年12月在亳州市人民医院接受健康体检的儿童100例作为研究对象。根据血清25-(OH)D水平对维生素D(Vit D)营养状况进行分组,其中严重缺乏组9例,缺乏组28例,不足组42例和充足组21例。对比不同年龄段和不同性别儿童血清25-(OH)D、BMD水平以及不同Vit D营养状况儿童对应的BMD水平,并采用Spearman相关性分析法分析血清25-(OH)D水平与儿童BMD、年龄的相关性。结果:5-9岁和10-14岁儿童的血清25-(OH)D及BMD水平均分别低于1-4岁儿童,而10-14岁儿童又低于5-9岁儿童(P0.05)。男童的血清25-(OH)D及BMD水平均分别高于女童,差异有统计学意义(P0.05)。不足组、缺乏组、严重缺乏组儿童的BMD水平均分别低于充足组,且缺乏组和严重缺乏组低于不足组,严重缺乏组又低于缺乏组(P0.05)。根据Spearman相关性分析结果显示,血清25-(OH)D水平与儿童BMD呈正相关,而与年龄呈负相关(P0.05),年龄与儿童BMD呈负相关(P0.05)。结论:血清25-(OH)D水平与儿童BMD呈正相关,但与年龄则呈负相关,及时补充适量的Vit D以满足儿童的机体所需,有利于儿童健康成长。     

冻干A+C群脑膜炎球菌多糖疫苗安全性和免疫原性观察

为了评价冻干A+C群脑膜炎球菌多糖疫苗(MPV)的安全性和免疫原性,按随机、盲法的原则,评价疫苗免疫后不良反应发生率、抗体阳转率及抗体几何平均滴度(GMT)。将606名健康观察者分为2～5岁、6～12岁、13～17岁、18～60岁四个年龄组,结果显示,该疫苗全身反应发生率2.64%,局部反应发生率1.32%,四个年龄组疫苗免疫后杀菌抗体阳性率分别为100%、100%、99.3%和100%,免疫后A群杀菌抗体GMT分别为1:250.47、1:190.61、1:144.22和1:205.79,免疫后C群杀菌抗体GMT分别为1:273.33、1:551.18、1:788.26和1:809.81,冻干A+C群多糖疫苗在≥2岁人群中具有良好的安全性和免疫原性,建议推广使用A+C群MPV。     

一种新的CTAB加入方法对A群脑膜炎球菌荚膜多糖分子大小的影响

目的探讨CTAB不同的加入方法对A群脑膜炎球菌荚膜多糖分子大小的影响。方法采用分次加入手动搅拌和持续加入机械快速搅拌两种CTAB加入方法,纯化获得荚膜多糖粗糖,分别编为B组和C组。将两组荚膜多糖粗糖分别纯化获得精糖,分别编为D组和E组。以Sepharose CL-4B凝胶层析纯化获得荚膜多糖并检测其KD值。结果 B组荚膜多糖粗糖的KD值介于0.34~0.35之间,C组荚膜多糖粗糖的KD值介于0.03~0.05,进一步用苯酚纯化获得精糖后KD值D组介于0.34~0.36之间,E组介于0.22~0.28之间。两组相比KD值显著降低。结论CTAB的加入过程对A群脑膜炎球菌荚膜多糖的分子大小有明显的影响,CTAB沉淀时进行快速而充分的搅拌,纯化获得的荚膜多糖相对分子质量更大。     

The effect of duration and time of food availability on the photoperiodic response in the male house sparrow, Passer domesticus

We investigated the effects of food availability on the seasonal testicular growth in the photoperiodic house sparrow (Passer domesticus). Two experiments were performed, each lasting 4 weeks. In experiment 1, sparrows were exposed to natural (NDL; group 1), short (8L:16D; group 2) and long (16L:8D; groups 3-5) day lengths with access to food ad libitum (groups 1-3) or for 10 h (zeitgeber time (zt) 0-10, group 4; zt 0 is the time of light onset) or for 8 h (zt 8-16, group 5). Testes recrudesced under long, but not short and natural, day lengths, and the recrudescence under long days was influenced by the duration of food availability. In experiment 2, the sparrows were exposed to short (8L:16D, group 1) and long (16L:8D, groups 2-5) day lengths with access to food ad libitum (for groups 1 and 2) or for 6 h (for groups 3-5) at different times during the 16 h light period (group 3- zt 0-6, group 4- zt 5-11, group 5- zt 10-16). As the expected, the testes recrudesced only under long lengths, but the photoinduction was variable among the 4 groups. The testes grew to full size in groups 2 and 3 that received food either ad libitum or for 6 h at zt 0-6, but to sub-maximal size in the groups that received 6 h food either at zt 5-11 (group 4) or at zt 10-16 (group 5). Altogether, these results support the idea that the photoperiodic regulation of reproduction in a seasonally breeding species is influenced both by the duration and the time of food availability.     

Role of protonatable groups of bovine heart bc(1) complex in ubiquinol binding and oxidation.

The pH dependence of the initial reaction rate catalyzed by the isolated bovine heart ubiquinol-cytochrome c reductase (bc1 complex) varying decylbenzoquinol (DBH) and decylbenzoquinone (DB) concentrations was determined. The affinity for DBH was increased threefold by the protonation of a group with pKa = 5.7 +/- 0.2, while the inhibition constant (Ki) for DB decreased 22 and 2.8 times when groups with pKa = 5.2 +/- 0.6 and 7.7 +/- 0.2, respectively, were protonated. This suggests stabilization of the protonated form of the acidic group by DBH binding. Initial rates were best fitted to a kinetic model involving three protonatable groups. The protonation of the pKa approximately 5.7 group blocked catalysis, indicating its role in proton transfer. The kinetic model assumed that the deprotonation of two groups (pKa values of 7.5 +/- 0.03 and approximately 9.2) decreases the catalytic rate by diminishing the redox potential of the iron-sulfur (Fe-S) cluster. The protonation of the pKa approximately 7.5 group also decreased the reaction rate by 80-86%, suggesting its role as acceptor of a proton from ubiquinol. The lack of effect on the Km for DBH when the pKa 7.5-7.7 group is deprotonated suggests that hydrogen bonding to this residue is not the main factor that determines substrate binding to the Qo site. The possible relationship of the pKa 5.2-5.7 and pKa 7.5-7.7 groups with Glu272 of cytochrome b and His161 of the Fe-S protein is discussed.     

Venous interruption is unnecessary to achieve an adequate delay in the rat TRAM flap model

Staged division of any or all inferior dominant pedicles to the human lower transverse rectus abdominis musculocutaneous (TRAM) flap has previously been attempted to invoke the delay phenomenon to enhance the rate of success with the superior-pedicled version, especially for patients at high risk for complications. Regardless of the specific vessels ligated, this has usually been accomplished by division of the source artery and its accompanying vein. Whether division of both vessels is essential remains unclear, however. This issue was investigated by using the authors' standard rat TRAM flap model in 43 female Sprague-Dawley rats, which were randomly assigned to four groups. In group A, both the predominant ipsilateral cranial epigastric artery and the cranial epigastric vein were divided 2 weeks before elevation of the TRAM flap. In group B, only the artery was divided; in group C, only the vein was divided. In an undelayed control group, the TRAM flap was elevated immediately, with no prior pedicle division. The percentages of flap survival in group A (89.3 +/- 7.0 percent) and group B (88.8 +/- 6.5 percent) (both with division of the predominant artery) were significantly greater than that in the control group (64.6 +/- 20.5 percent) (p < 0.001) or that in the group in which the vein alone was divided (73.9 +/- 11.3 percent) (p < 0.01). There was no significant difference between the group that underwent vein division only and the control group (p = 0.102). The clinical implication is that arterial division is critical for TRAM flap delay and that arbitrary venous interruption is unnecessary.     

厚朴居群叶表皮毛的显微特征差异及分类意义

叶片的微观形态特征包括表皮的毛被特征,在现代植物分类研究中被越来越多地应用于疑难类群的分类鉴定中。厚朴为我国常用中药,该分类群的分类地位一直存在着很大争议。该研究选取16个厚朴的天然群体,运用光学和电子显微镜观测不同居群厚朴叶片的毛被特征,并通过对显微特征的UPMGA聚类分析,了解其分类地位及亲缘关系。结果表明：不同居群厚朴叶表皮毛差异显著,表皮毛各特征均呈现出多态性。16个居群厚朴叶表皮大致可以分为两类形态,一类由2~3个细胞组成,表皮毛直立或微倒伏,长147.48~489.21μm,顶细胞长度远长于其他细胞,与其他细胞的衔接方式为直接;另一类表皮毛由2~7个细胞组成,弯曲或扭曲,全长251.70~489.21μm,顶细胞长176.47~353.23μm,与其余细胞形成一定的夹角(123.31°~150.61°),顶细胞与其他细胞的衔接方式以钝接为主。16个样本可以分为两个类群———直立型和弯曲型,所划分的类群与根据叶形划分的类型基本一致。直立型表皮毛又可以划分为粗短型和细长型,所划分的类群对应的叶形为小凸尖型的厚朴和中间型厚朴。因此,该研究结果证实厚朴在归并为一个种后,将其分为3个地理亚种是合理的。     

Pioglitazone prevents cardiac remodeling in high-fat, high-calorie-induced Type 2 diabetes mellitus

The agonists of peroxisome proliferator-activated receptor-gamma (PPARgamma) ameliorate cardiovascular complications associated with diabetes mellitus. We tested the hypothesis that recovery from ailing to failing myocardium in diabetes by PPARgamma agonist is in part due to decreased matrix metalloproteinase-9 (MMP-9) activation and left ventricular (LV) tissue levels of homocysteine (Hcy). C57BL/6J mice were made diabetic (D) by feeding them a high-fat calorie diet. PPARgamma was activated by adding pioglitazone (Pi) to the diet. After 6 wk, mice were grouped into: normal calorie diet (N), D, N + Pi and D + Pi (n = 6 in each group). LV variables were measured by echocardiography, endothelial-myocyte (E-M) coupling was measured in cardiac rings, and MMP-9 activation was measured by zymography. Blood glucose levels were twofold higher in D mice compared with N mice. Pi decreased the levels of glucose in D mice to the levels in N mice. LV Hcy levels were 3.5 +/- 0.5 microM in N groups compared with 12.4 +/- 0.6 microM in D groups. Treatment with Pi normalized the LV levels of Hcy but had no effect on plasma levels of Hcy. In the D group, LV contraction was reduced compared with that of the N group and was ameliorated by treatment with Pi. LV wall thickness was reduced to 0.25 +/- 0.02 mm in the D group compared with 0.42 +/- 0.01 mm in the N group. LV diastolic diameter was 3.05 +/- 0.01 mm in the D group compared with 2.20 +/- 0.02 mm in the N group. LV systolic diameter was 1.19 +/- 0.02 mm in the D group and 0.59 +/- 0.01 mm in the N group. Pi normalized the LV variables in D mice. The responses to ACh and nitroprusside were attenuated in diabetic hearts, suggesting that there was E-M uncoupling in the D group compared with the N group, which was ameliorated by Pi. Plasma and LV levels of MMP-2 and -9 activities were higher in the D group than in the N group but normalized after Pi treatment. These results suggest that E-M uncoupling in the myocardium, in part, is due to increased MMP activities secondary to suppressing PPARgamma activity in high-fat, calorie-induced Type 2 diabetes mellitus.     

Cytoreductive surgery with intraperitoneal chemotherapy in patients with colon cancer and peritoneal carcinomatosis]

The efficacy of cytoreductive approach for colon cancer with carcinomatosis was assessed. 34 patients (the main group) underwent colon resections, peritonectomy, omentectomy and intraperitoneal chemotherapy (mitomycin and 5-fluorouracil). 22 patients (control group) underwent palliative colon resections only. The spread of peritoneal dissemination was assessed in all patients, basing on Peritoneal Cancer Index (PCI). It was found, that the rate of postoperative morbidity is higher in the main group, but it was not accompanied by enhanced postoperative mortality. It was also detected, that cytoreductive approach permits to prolong the survival (17.0 +/- 3.5 months in main group vs. 7.5 +/- 2.1 months in controls). The main prognostic factor in these patients was the PCI. The most favorable prognosis is identified if PCI < 5 (few discrete implants are present); the survival in this group was 23.0 +/- 4.5 months and disease-free interval was 14.0 +/- 2.5 months. When PCI was higher then 5, the survival was 14.5 +/- 2.5 months and disease-free interval was 7.0 +/- 1.3 months.     

接种马铃薯软腐病菌引起的烟草叶片爆发

用马铃薯软腐病菌处理烟草后,以化学法测定了叶片中O-2含量,发现在接种后1～14 h内只出现一次O-2爆发,不同于以往植物悬浮细胞研究中出现的两次爆发结果.接种软腐病菌后2 h和6 h烟草叶片O-2的电子自旋共振波谱图(electron spin resonance,ESR)显示了同样的一次O-2爆发结果.接种后烟草叶片的线粒体和叶绿体O-2爆发与叶片的同步,显示此两种细胞器参与烟草叶片在软腐病菌作用下的O-2发生.无光照叶绿体O-2的ESR谱线不出现,表明叶绿体O-2可能来源于光合电子传递链.马铃薯软腐病菌作用下烟草叶片的O-2爆发是多位点的.     

Evidence that the C-terminus of the D1 polypeptide of photosystem II is ligated to the manganese ion that undergoes oxidation during the S1 to S2 transition: an isotope-edited FTIR study

Isotope-edited FTIR difference spectroscopy was employed to determine if the C-terminal alpha-COO(-) group of the D1 polypeptide ligates the (Mn)(4) cluster in photosystem II (PSII) and, if so, if it ligates the Mn ion that undergoes an oxidation during the S(1) --> S(2) transition. Wild-type and mutant cells of the cyanobacterium Synechocystis sp. PCC 6803 were propagated photoautotrophically in the presence of L-[1-(13)C]alanine or unlabeled ((12)C) L-alanine. In wild-type cells, both the C-terminal alpha-COO(-) group of the D1 polypeptide at D1-Ala344 and all alanine-derived peptide carbonyl groups will be labeled. In D1-A344G and D1-A344S mutant cells, the C-terminal alpha-COO(-) group of the D1 polypeptide will not be labeled because this group is no longer provided by alanine. The resultant S(2)-minus-S(1) FTIR difference spectra of purified wild-type and mutant PSII particles showed that one symmetric carboxylate stretching mode that is altered during the S(1) --> S(2) transition is sensitive to L-[1-(13)C]alanine-labeling in wild-type PSII particles but not in D1-A344G and D1-A344S PSII particles. Because the only carboxylate group that can be labeled in the wild-type PSII particles but not in the mutant PSII particles is the C-terminal alpha-COO(-) group of the D1 polypeptide, we assign the L-[1-(13)C]alanine-sensitive symmetric carboxylate stretching mode to the alpha-COO(-) group of D1-Ala344. In unlabeled wild-type PSII particles, this mode appears at approximately 1356 cm(-1) in the S(1) state and at approximately 1339 or approximately 1320 cm(-1) in the S(2) state. These frequencies are consistent with unidentate ligation of the (Mn)(4) cluster by the alpha-COO(-) group of D1-Ala344 in both the S(1) and S(2) states. The apparent 17-36 cm(-1) downshift in frequency in response to the S(1) --> S(2) transition is consistent with the alpha-COO(-) group of D1-Ala344 ligating a Mn ion whose charge increases during the S(1) --> S(2) transition. Accordingly, we propose that the alpha-COO(-) group of D1-Ala344 ligates the Mn ion that undergoes an oxidation during the S(1) --> S(2) transition. Control experiments were conducted with Mn-depleted wild-type PSII particles. These experiments showed that tyrosine Y(D) may be structurally coupled to the carbonyl oxygen of an alanine-derived peptide carbonyl group.     

云南玉溪地区人口的性比

对云南玉溪地区1982年人口普查时的性比(男:女100)进行了分析,发现:(1)玉溪地区总人口的性比(99.22)比全国的(106.3)低,0—4岁与5—9岁儿童的性比(103.45与102.9)也比全国的(107.15与106.24)低。(2)傣族的性比特别低,其0—14岁儿童的性比为98.54;回族的性比也较低,其0—14岁儿童的性比为101.22;汉族0—14岁儿童性比则为104.16。(3)“大跃进”与“国民经济暂时困难”时期出生的人(20—24岁)性比特别低,仅为92.30,而且按民族,县,及城、乡分别统计时均有同样趋势。这一情况在全国人口性比统计中也得到证实。作者估计,这可能是当时自然流产增多造成的。(4)玉溪地区解放以来总人口性比不断增高,1953年为88.70,1964年为94.94,1982年则为99.22。(5)城镇人口的性比(156.48)比农村的(95.86)高得多,这与全国各地区相同。     

Effects of tempol on renal angiotensinogen production in Dahl salt-sensitive rats

We have recently reported that Dahl salt-sensitive rats (DS) on high salt diet (HS) have an inappropriate augmentation of intrarenal angiotensinogen. Recent studies also reported that the augmented superoxide anion formation plays important roles in this animal model of hypertension. This study was performed to address the hypothesis that an inappropriate augmentation of intrarenal angiotensinogen by HS is caused by the augmented reactive oxygen species. Male DS (200-220 g) were maintained on low salt diet LS (N = 7) or HS (N = 27) for 4 weeks. The HS group was subdivided into three subgroups to receive null (N = 12), superoxide dismutase mimetic, tempol (3 mmol/l, N = 8), or vasodilator, hydralazine (0.5 mmol/l, N = 7) in drinking water during the period. Systolic BP was significantly increased in the DS+HS group compared to the DS+LS group (184+/-7 mmHg vs. 107+/-5 at 4-week). Tempol or hydralazine treatment equivalently attenuated the hypertension (128+/-3 and 127+/-5 at 4-week, respectively). Urinary excretion of thiobarbituric acid reactive substances at 4-week was significantly increased in the DS+HS group compared to the DS+LS group (0.66+/-0.05 micromol/day vs. 0.14+/-0.01). Tempol treatment prevented this effect (0.24+/-0.04) but hydralazine treatment only partially prevented the effect (0.40+/-0.03). Kidney angiotensinogen levels, measured by Western blot analysis, were significantly increased in the DS+HS group compared to the DS+LS group (32+/-5 densitometric units vs. 21+/-1). Tempol (14+/-3) but not hydralazine (32+/-5) treatment prevented the intrarenal angiotensinogen augmentation. The evidence suggests that the enhanced intrarenal angiotensinogen in DS challenged with HS is associated with the augmented reactive oxygen species.     

Dynamics of the phosphate group in phospholipid bilayers. A 31P nuclear relaxation time study.

The spin-lattice relaxation time of the 31P nucleus in the phosphate group of egg yolk phosphatidylcholine multilamellar dispersions has been investigated at four resonant frequencies (38.9, 81.0, 108.9, and 145.7 MHz) in the temperature range from -30 degrees to 60 degrees C. The observed frequency dependence of the relaxation indicates that both dipolar relaxation and relaxation due to anisotropic chemical shielding are significant mechanisms. The experimental data have thus been modeled assuming both mechanisms and the analysis has allowed the contribution of each to the relaxation to be determined along with the correlation time for the molecular reorientation as a function of temperature. Dipolar relaxation was found to dominate at low nuclear magnetic resonance frequencies while at high frequencies the anisotropic chemical shift dominates. The correlation time of the phosphate group is on the order of 10(-9) s at 60 degrees C and increases to approximately 10(-7) s at -30 degrees C. It is observed that the freezing of the buffer which occurs at approximately -8 degrees C has a significant effect on the phosphate group reorientation. This effect of the freezing is to change the activation energy for the phosphate group reorientation from 16.9 KJ/mol above -8 degrees C to 32.5 KJ/mol below -8 degrees C.     

Correlation of hereditary and environmental effects on external respiratory function and its changes during aging in twins

The genetic-statistical analysis of 11 variables of the external respiration has been made in 90 twin pairs of the same sex divided into two age groups: 20-44 and 45-80 years. The following classification of indices of the lung ventilation function can be suggested: with high hereditary coefficients that remain unchanged with age, with low coefficients gamma 2 that are the same in both age groups, with increasing hereditary coefficients in aging, and with the high Ignatiev-Jensen criteria in the group of people aged 20-44 and declining ones in the group aged 45-80. The last group of ventilation variables is the largest. In the group aged 20-44 a test with oxygen inhalation increases the effect of environmental factors whereas in the group aged 45-80 it decreases this effect on the indices of the lung ventilation.