首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Abstract— Proteins of the brain extracts of 85 individual pigeons (Columba livia) were mapped by two-dimensional gel electrophoresis. The method is a modification of O'Farrell 'S technique and separates proteins first by charge and then by molecular weight. There were three proteins, A, B and D which had each a variant form. The positions of these six proteins on the gel corresponded to the following pH values and molecular weight values: protein A1, 6.4/43,000; A2, 6.6/43,000; B1, 5.7/41,000; B2, 5.8/40,000; D1, 6.2/22,000; D2, 6.2/21,000. The variants are genetically determined, since protein A, B and D each occurred in three phenotypes (A1, A1A2 and A2; B1, B1B2 and B2; D1, D1D2 and D2) corresponding to the three possible genotypes. From the observed frequencies of the phenotypes the following allele frequencies were calculated: allele A1, 72%; A2, 28%; B1, 15%; B2, 85%; D1, 74%; D2, 26%. A fourth protein named C occurred in four different forms (C1, 7.2/37,000; C2, 7.2/36,000; C3, 7.1/37,000; C4, 7.1/36,000) and six phenotypes (C1, C1C2, C2, C1C3, C2C3 and C4C3). This polymorphism is also interpreted as being genetically determined. The four alleles coding for the four protein C forms had the following frequencies: allele C1, 62%; C2, 27%; C3, 10.5%; C4, 0.5%.  相似文献   

2.
Blood specimens from 69 gibbons (63Hylobates lar, 4Hylobates concolor, and 2Hylobates pileatus) were tested for human-type ABO, MN, and Rh blood groups. AmongH. lar, three phenotypes were noted in the ABO and MN blood groups respectively, but all fourH. concolor were grouped as AM. All group A gibbons were of subgroup A1; subgroups A2B and A12B were observed at a low frequency in group AB gibbons. Leb antigen was detected in about 30% of the red cell samples fromH. lar, but all the samples were negative for Lea. All the gibbons tested had c(hr) antigen but no other Rh antigens (D, C, E, and e) in their red cells. Some selected blood samples fromH. lar were also tested for some other blood group antigens and for the Gm and Inv factors. The Jka antigen was detected in all the red cell samples tested, but the S, s, U, K, k, and Fya antigens were not. In the tests of plasma with anti-Gm (1),H. lar could be divided into two groups, i.e., Gm(1)Gi and Gm(–1)Gi; Gm(2), Gm(4), and Inv(1) were absent in the species.  相似文献   

3.
According to integral characterization of gene frequencies of the investigated loci AB0, MN, Rh, GLO1, PGM1, EsD, AcP, 6-PGD, Hp, Tf, Gc, C'3 and ChE2, Mongolian population has high level of polymorphism, with the exception of haplotypes R" (cdE) and Ry(CdE) at the Rh locus and TfB0-1 at the Tf locus. The data on biochemical and immunological polymorphic gene markers analysed in the population of Mongolia show that the Mongolians have some distinctive features, in comparison with the mean-in-the-world characteristics: high frequencies of the B genes at the AB0 locus; D, E, R1 and R2 at the Rh locus; GLO11, PGDc, TfDChi, E2(C5+), PGM1(1+); low frequencies of the genes A(AB0), R0(Rh), AcPc, Hp1, Gc2, C'3F, PGM 1(2-); the rest of the genes at the above-mentioned loci and the genes of the locus MN have the mean-in-the-world frequencies.  相似文献   

4.
As tested by anti-A and anti-B sera, blood drawn from 30,000 inhabitans of Bogotá, Colombia, showed the following phenotype percentages: A — 26.5, B — 8.0, AB — 1.1, and O — 64.4. The allele frequencies were: A — 0.150, B — 0.048, and O — 0.802. In the same samples anti-D (Rh0) was used: 94.6% of the individuals carried the D antigen. All bloods were typed with fresh commercial sera. No back-typing was performed. Hemolytic disease of the newborn, caused by Rh-Hr isoimmunization, is more frequent (0.40%) in Bogotá than should be expected for a population having only (5.4%) or less “Rh negative” individuals. This paradoxical fact was observed in the analysis of 12,672 deliveries in an obstetrical hospital of Bogotá. A possible explanation could be the multiparity of Colombian women since the possibility of isoimmunization and hemolytic disease increases with each succeeding pregnancy in a given woman. Also it is well established that when Rh-Hr incompatibility is combined with ABO incompatibility, it is less apt to produce disease than when it occurs alone. AO isoimmunization should therefore be less frequent in Bogotá than in populations that have a higher frequency of A individuals. Thus, the women of Bogotá are less “protected” from Rh-Hr immunization by ABO incompatibility.  相似文献   

5.
Summary Nearly three and a half thousand sera obtained from various populations were tested serologically to obtain evidence of past infection with influenza A viruses that were prevalent from 1947 to 1972.No significant difference was found between the distributions of the levels of these antibodies of individuals of blood groups A and 0, A1 and 0, Rh (D+) and Rh (D-) and MM, MN and NN.The significance of these findings is discussed.  相似文献   

6.
Phospholipase A2 modification of lipid-protein interactions of normal O,Rh(D) positive erythrocyte membranes increased the fluorescence intensity of the membrane bound probe, 1-anilinonaphthalene-8-sulfonate (ANS) and increased the N-1-[14C]-ethyl maleimide ([14C]-NEM) labeling of sulfhydryl groups in two proteins of molecular weight >200,000. In marked contrast, phospholipase A2 modification of the rare phenotype O,Rhnull membranes resulted in no significant increase in ANS fluorescence or labeling of sulfhydryl groups by [14C] NEM. Since the O,Rhnull erythrocytes demonstrated an increased osmotic fragility and decreased survival time, the fluorescence and sulfhydryl labeling data support the conclusion that hydrophobic bonding between β-fatty acid side chains and non-polar regions of asymmetric proteins is necessary for maintaining the native structure of the O,Rh(D) positive membrane. Comparative studies with phospholipase C or D implied that ionic bonding played a similar though less important structural role in both membranes.  相似文献   

7.
A study is carried out on the distribution of ABO, MN, Rh, P and Le blood groups systems, haptoglobins, and common anthropogenetic features in the population of two villages of the Samarkand district. The examined samples have appeared to be heterogenous for ABO, Rh and P systems. For MN and Le unification is possible. The summary data on the allotment of phenotypes are as follows: (%) 0-30.2, A-35.3, B-26.2, AB-8.3, M-33.9, N-26.2, MN-39.9, Rh- -1.5, P-78.6, Le(a-b+)-33, Le (a+b-)-22.2, Le(a-b-)-34.2, Le(a+b+)-10.6. Gene frequencies have are calculated. The occurrence with regards to haptoglobins in both the villages is the same. The summary data are as follows: Hp1=1-4.8, Hp1=2-36.2, Hp2=2-59%. Gene frequencies have been calculated. In the population of the village Karakent there is a change of the frequency in many features of dermatoglyphics. The frequencies of anthropogenetic features do not differ between the villages. The summary data are the following: the frequency of theelbow type of hand is 86.9%, the right type of "hand clasping"-55.0%, the right type of "arm folding"-50.4%, righthandedness-99.7%. The occurence of square lobe of the ear is 21%, spliced one is 26.2%, the hanging down is 52.7%. The frequency of the gene insensitivity for PTC taste is 0.47 in one village and 0.53 in the other.  相似文献   

8.
In the present study, the possible role of genetic polymorphism of three drug-metabolizing enzymes, debrisoquine/sparteine hydroxylase (CYP2D6), glutathione S-transferase μ (GSTM1), and N-acetyltransferase (NAT2), as a putative genetic component of human longevity, was explored. A total of 817 DNA samples from a centenarian and a control (20–70 years) population was subjected to PCR-coupled RFLP methods. Subjects were genotyped for the CYP2D6*3 (A2637 deletion) and CYP2D6*4 (G1934A transition) alleles, for four mutations of NAT2 [namely, NAT2*5A (C481T), NAT2*6A (G590A), NAT2*7A (G857A), and NAT2*14A (G191A)], and for the presence or absence of GSTM1 gene deletion. No significant difference was found at these three loci between centenarian and control subjects with respect to allelic variant frequencies, genotype distributions or predicted phenotypes deduced from genotype combinations. By comparing the distribution of combined genotypes for the polymorphisms tested at the CYP2D6, NAT2, and GSTM1 loci, none of the predicted phenotypes concerning debrisoquine hydroxylase extensive-metabolizer or poor-metabolizer phenotypes, slow or fast N-acetylation capacities, and active or defective glutathione S-transferase, could be correlated with human longevity, alone or in combination. Received: 4 September 1997/Accepted: 13 December 1997  相似文献   

9.
Nitrous oxide (N2O) emissions can be significantly affected by the amounts and forms of nitrogen (N) available in soils, but the effect is highly dependent on local climate and soil conditions in specific ecosystem. To improve our understanding of the response of N2O emissions to different N sources of fertilizer in a typical semiarid temperate steppe in Inner Mongolia, a 2-year field experiment was conducted to investigate the effects of high, medium and low N fertilizer levels (HN: 200 kg N?ha-1y-1, MN: 100 kg N ha-1y-1, and LN: 50 kg N ha-1y-1) respectively and N fertilizer forms (CAN: calcium ammonium nitrate, AS: ammonium sulphate and NS: sodium nitrate) on N2O emissions using static closed chamber method. Our data showed that peak N2O fluxes induced by N treatments were concentrated in short periods (2 to 3 weeks) after fertilization in summer and in soil thawing periods in early spring; there were similarly low N2O fluxes from all treatments in the remaining seasons of the year. The three N levels increased annual N2O emissions significantly (P?<?0.05) in the order of MN > HN > LN compared with the CK (control) treatment in year 1; in year 2, the elevation of annual N2O emissions was significant (P?<?0.05) by HN and MN treatments but was insignificant by LN treatments (P?>?0.05). The three N forms also had strong effects on N2O emissions. Significantly (P?<?0.05) higher annual N2O emissions were observed in the soils of CAN and AS fertilizer treatments than in the soils of NS fertilizer treatments in both measured years, but the difference between CAN and AS was not significant (P?>?0.05). Annual N2O emission factors (EF) ranged from 0.060 to 0.298% for different N fertilizer treatments in the two observed years, with an overall EF value of 0.125%. The EF values were by far less than the mean default EF proposed by the Intergovernmental Panel on Climate Change (IPCC).  相似文献   

10.
Blood specimens from Brahmin and Kamma caste populations of Coastal Andhra Pradesh, India are examined for A1A2BO, MNSs, and Rhesus blood groups. Predominance of A group in Brahmins and B group in Kammas is observed. Phenotype A2 records less than 4% in both populations. High frequencies of genes M, s, D, and e are exhibited among both populations. Statistically significant differences are found only for A1A2BO system between Brahmins and Kammas.  相似文献   

11.
Abstract: Competition [3H]RX821002 ([3H]2-methoxyidazoxan) binding experiments with α2-adrenoceptor subtype-specific antagonists—BRL 44408 (α2A selective), ARC 239 (α2B selective), and others—were performed to delineate through rigorous computer modeling receptor subtypes in the postmortem human brain. In the hippocampus, hypothalamus, cerebellum, and brainstem the whole population of α2-adrenoceptors appears to belong to the α2A subtype (100%; Bmax = 34–90 fmol/mg of protein). In the frontal cortex, the predominant receptor was the α2A subtype (87%; Bmax = 53 fmol/mg of protein), although a small population of the α2B/C subtype (13%; Bmax = 8 fmol/mg of protein) was also detected. In the caudate nucleus, a mixed population of α2A (64%; Bmax = 9 fmol/mg of protein) and α2B/C (36%; Bmax = 5 fmol/mg of protein) subtypes was detected. In the cortex and caudate and in the presence of ARC 239 (to mask the α2B/C-adrenoceptors), competition experiments with the agonist guanoxabenz clearly modeled the high- and low-affinity states of the α2A subtype. In the presence of ARC 239 and the GTP analogue guanylyl-5′-imidodiphosphate together with NaCl and EDTA (to eliminate the high-affinity α2A-adrenoceptor) guanoxabenz only recognized the low-affinity α2A-adrenoceptor. The results indicate that in the human brain the predominant α2-adrenoceptor is of the α2A subtype and that this functionally relevant receptor subtype is not heterogeneous in nature.  相似文献   

12.
The present paper reports the distribution of blood groups and ABH saliva secretion in two Andhra tribal populations: the Koya Dora and the Konda Kammara. 100 Koya Dora and nearly 110 Konda Kammara adults of both sexes were tested for A1A2BO, MN, Rh (CcDEe) blood groups and ABH saliva secretion. The gene frequencies for A1A2BO, MN and ABH and the gene as well as chromosome frequencies for Rh (CcDEe) systems were calculated. Koya Doras show a higher incidence of A gene than B gene, while the reverse trend is seen in Konda Kammaras. Both the tribes show a high M gene frequency. No Rh(D) negative individual was found in Koya Doras, while 4.59% of Konda Kammaras are Rh(D) negative. The chromosomes CDE, CdE, cDe, cdE, Cde and cde are absent in Koya Doras, while only the four chromosomes CDE, CdE, cDe and cdE are absent in Konda Kammaras. The chromosome CDe shows the highest frequency in both the tribes. The frequency of secretors is, as usual, higher than that of nonsecretors in both the tribes. The intergroup variation between the two tribes is not statistically significant for MN, Rh (CcDEe) and ABH systems, while the difference is significant for the A1A2BO blood groups. Suitable comparisons have also been made with all the other available data from Andhra Pradesh tribal populations with respect to different systems studied. Finally Fi estimates have been calculated after Harpending et al. (1973) and Workman et al. (1974) for Koya Doras and Konda Kammaras to assess their degree of endogamy, considering the codominant systems studied, which suggest that Koya Doras are relatively more isolated than Konda Kammaras.  相似文献   

13.
安徽省宁国县畲族红细胞血型分布   总被引:2,自引:0,他引:2  
调查160名安徽省宁国县畲族村民的ABO、Rh、P、MN系统红细胞血型,结果显示ABO血型表型频率分布为O(0.4687)〉B(0.2375)〉A(0.2250)〉AB(0.0688),基因频率p=0.1500,q=0.1575,r=0.6925;Rh血型表型频率分布为CCdee(0.5385)〉CCDE(0.1667)〉CcDE(0.1474)〉CcDee(0.0961)〉ccDE(0.0321  相似文献   

14.
Abstract

The complementary consensus acceptor exon:intron junction d(ApCpCpTpGpTpApG) has been synthesized by a modified phosphotriester method. The non self-complementary octamer exists in the random coil form in aqueous buffer at 20°C as evidenced by temperature variable 1H-NMR and NOE measurements. The non-exchangeable proton assignments were secured using a combination of techniques including two-dimensional COSY, NOESY and 1H-1H-INADEQUATE. The octamer was annealed with the primary consensus sequence d(CpTpApCpApGpGpT). Confirmation of complete duplex formation was confirmed by detection and assignment of imino protons in D2O:H2O mixtures. Assignment of the nonexchangeable proton signals in the duplex consensus junction was then secured by a combination of two-dimensional COSY correlations, NOESY and NOE experiments. Determination of individual vicinal coupling constants in the component deoxyribose moieties permitted deduction of the population of S conformations in this sequence. It is concluded that the consensus acceptor junction exists in solution in a conformation belonging to the B family, and that the bases are oriented anti. In addition the deoxyribose moieties in the 5′ regions exist predominantly in the S form (2′endo—3′exo) whereas those residues on or adjacent to the junction on the primary strand show more N character (2′exo—3′endo). The contiguous bases A5-G6 (adjacent to the junction) and A15-G16 are stacked more closely than the other neighbor bases in this duplex sequence. These subtle structural and conformational differences in the exon:intron junction may serve as recognition signals for these critical sites in the genome.  相似文献   

15.
Emissions of nitrous oxide (N2O) from the soil following simulated nitrogen (N) deposition in a disturbed (pine), a rehabilitated (pine and broadleaf mixed) and a mature (monsoon evergreen broadleaf) tropical forest in southern China were studied. The following hypotheses were tested: (1) addition of N will increase soil N2O emission in tropical forests; and (2) any observed increase will be more pronounced in the mature forest than in the disturbed or rehabilitated forest due to the relatively high initial soil N concentration in the mature forest. The experiment was designed with four N treatment levels (three replicates; 0, 50, 100, 150 kg N ha−1 year−1 for C (Control), LN (Low-N), MN (Medium-N), and HN (High-N) treatment, respectively) in the mature forest, but only three levels in the disturbed and rehabilitated forests (C, LN and MN). Between October 2005 to September 2006, soil N2O flux was measured using static chamber and gas chromatography methodology. Nitrogen had been applied previously to the plots since July 2003 and continued during soil N2O flux measurement period. The annual mean rates of soil N2O emission in the C plots were 24.1 ± 1.5, 26.2 ± 1.4, and 29.3 ± 1.6 μg N2O–N m−2 h−1 in the disturbed, rehabilitated and mature forest, respectively. There was a significant increase in soil N2O emission following N additions in the mature forest (38%, 41%, and 58% when compared to the C plots for the LN, MN, and HN plots, respectively). In the disturbed forest a significant increase (35%) was observed in the MN plots, but not in the LN plots. The rehabilitated forest showed no significant response to N additions. Increases in soil N2O emission occurred primarily in the cool-dry season (November, December and January). Our results suggest that the response of soil N2O emission to N deposition in tropical forests in southern China may vary depending on the soil N status and land-use history of the forest.  相似文献   

16.
The reaction between [Rh(H2O)6](ClO4)3 and the monoanion Hdopn (H2dopn=bis(diacetylmonoxime-imino)propane 1,3=3,9-dimethyl-4,8-diazaundeca-3,8-diene-2,10-dione dioxime) afforded a new dimeric rhodium(II) compound of formula [Rh(Hdopn)(H2O)]2(ClO4)2 · H2O (1). Treatment of methanolic solution of 1 with NaX (X=Cl, Br, I) results in the replacement of water with halides in 1, leading to the formation of [Rh(Hdopn)X]2 rhodium(II) dimers. The X-ray crystal structure of [Rh(Hdopn)Cl]2 · 0.5H2O (2) was determined showing a [Rh(II)-Rh(II)] core. Upon the reaction of 1 with NaI carried out in air, [Rh(Hdopn)(I)2] (3) was isolated and characterized by a single-crystal X-ray diffraction analysis.  相似文献   

17.
Summary Genetic polymorphism of human plasminogen (PLG) was investigated in 1252 unrelated individuals from eight South African Bantu-speaking Negro tribes. PLG phenotypes were determined by isoelectric focusing (pH 3.5–9.5 and 5–8 gradients) of neuraminidase-treated samples and subsequent detection by caseinolytic overlay or immunoblotting with specific antibody. No significant difference in the distribution of PLG alleles among the eight ethnic groups was observed. The combined allele frequencies of the common alleles in South African Negroes were 0.6977 for PLG*A, 0.2736 for PLG*B. In addition, six rare alleles were seen: PLG*A3, *A1, *M2, *B1, *B2, *B3. The rare variant PLG*B2 was proven to segregate by autosomal Mendelian inheritance in a family. The combined frequency for the rare alleles was 0.0287. The distribution of phenotypes in the total population sample was found to be in Hardy-Weinberg equilibrium. A striking difference in PLG allele distribution between Negroes from South Africa and published Negroid frequencies from North America could be observed. This difference was also seen in comparison with Mongoloid populations; in contrast, PLG frequencies for South African Negroes were similar or almost identical to known Caucasoid distributions.  相似文献   

18.

INTRODUCTION:

Increase in the instability of cellular genome with an increasing age is the result of an accumulation of cellular damage and mutations. This instability which might be observed as chromosome damage or chromosome losses can be measured by the micronucleus technique.

AIM:

The aim of this study was to investigate the effect of aging and oxidative stress induced by non-toxic levels of H2O2 on micronuclei induction and their relationship to cell proliferation in human peripheral blood lymphocytes.

MATERIALS AND METHODS:

Healthy volunteers with different ages were choosen. Spontaneous and H2O2 induced micronuclei frequencies were measured in peripheral blood lymphocytes of 30 volunteers by the micronucleus method.

RESULTS:

Spontaneous micronuclei frequencies increased first then started to decrease after 50 years of age. This biphasic response was significantly higher than micronucleus (MN) frequencies induced by H2O2 (P < 0.05), which followed the similar shape of response to increasing ages with lower frequencies. Proliferative capacity of cells either treated with H2O2 or not did not differ with an increasing age giving similar responses.

CONCLUSION:

These results indicate biphasic character of chromosome damage; first increase and decrease after 50 years with an increasing age. But this change pattern was not correlated with the steady state of proliferation capacity of cells through an increasing age. Decreases in H2O2-induced MN frequencies compared to spontaneous MN frequencies may be inducing an apoptosis by H2O2 treatment leading to underscoring damaged cells.  相似文献   

19.
A total of 2, 490 South American Indians affiliated with 10 tribes were studied for esterases A1, A2, A3, B, D, and carbonic anhydrases 1 and 2. Wide variation was observed in the prevalence of ESD1, the extreme values being 0. 44, encountered among the Xikrin, and 0. 95, found among the Cashinawa. Seven of the 10 frequencies fell within the interval of 0. 66–0. 87. These results were integrated with those of earlier surveys. In a general way we observe lower values in the eastern and Atlantic Coast groups, but this is mainly due to the low frequencies found among the Gê tribes and the Caingang, who speak a language which has many affinities with Gê. High prevalences were observed among the tropical forest tribes. A fair amount of intervillage, intratribal variation was found among the Ticuna and Caingang. No variability was detected in the A1, A2, A3, B esterases. In the carbonic anhydrases we confirmed the presence of a “private polymorphism” among the Baniwa.  相似文献   

20.
The process of electron transfer from the primary electron donor P* to the primary electron acceptor BA in the reaction center of Rhodobacter sphaeroides R-26 under 30 fsec pulse excitation was studied in this work with the aim of establishing a relationship between the nuclear subsystem motion and charge transfer. For this purpose the fsec and psec oscillations in the bands of stimulated emission of P* and in the band of reaction product B A - at 1020 nm were investigated. It was established that the reversible formation of the P+B A - state is characterized by two vibration modes (130 and 320 cm-1) and connected with an arrival of the wavepacket induced by fsec excitation to the intersection of potential surfaces P*BA and P+B A - . The irreversible formation of the P+B A - state with the time constant of 3 psec is followed by oscillations with frequencies of 9 and 33 cm-1. These results show that the irreversibility of electron transfer is determined by two factors: 1) by a difference between the energy width of the wavepacket and the gap between the named surfaces; 2) by a difference between the duration of wavepacket residence near the intersection of the surfaces and the relaxation time of the P+B A - state.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号