彝族、藏族与哈尼族血清胆硷酯酶的遗传多态性

按照Kalow等的方法对中国3个人群的血清胆硷酯酶(简称ChE)的遗传多态性进行了研究。3个人群是四川省布拖县彝族(197人)、西藏自治区拉萨市藏族(100人)及云南省元江县哈尼族(170人)。根据每一个体的地布卡因值和氟化钠值,按Motulsky的分型标准进行分型。结果表明,在彝族中有3人属一般型+抗氟化物型(UF);在藏族中有2名UF;在哈尼族中也有3名UF,未发现不典型型(即抗地布卡因型的纯合子与杂合子),也未发现抗氟化物型的纯合子。因此,E_1~f基因频率在彝族、藏族与哈尼族中分别为0.0076、0.0100及0.0088。正常的常见等位基因E_1~(?)的频率分别为0.9924、0.9900及0.9912。这3个人群ChE表型分布均符合Hardy-Weinberg平衡法则。他们的基因频率与蒙古人种其他人群是一致的。     

Incidence of C5 isozyme of serum cholinesterase (E2 locus) in populations of Andhra Pradesh, South India

The distribution of the C5 isozyme of the serum cholinesterase (E2 locus) was studied in several endogamous Hindu caste groups and Muslim sub-sects of Andhra Pradesh in South India. Both intra and inter population variation was marked with a comparatively low incidence of C5 in the populations studied.     

Histochemically demonstrable catecholamines and cholinesterases in nerve fibres of rat dorsal skin

Summary Histochemically demonstrable cholinesterases of rat skin and cutaneous nerves hydrolyze acetylthiocholine iodide and butyrylthiocholine iodide. Cholinesterase activity of the skin was located in the epidermis, in the hair follicles at the level of the sebaceous glands, in adjacent parts of the sebaceous glands, in erector pili muscles and their nerves, in cutaneous and subcutaneous nerves and nerve trunks, including some nerves accompanying cutaneous blood vessels, and in the membranes of fat cells. No encapsulated nerve endings were found. In the nerves of erector pili muscles there was some neurilemmal non-specific cholinesterase activity, demonstrated in the presence of 10^–5 M BW 284C 51, and specific acetylcholinesterase activity resistant to 10^–5 M iso-OMPA. The cholinesterase activity in other cutaneous nerves was inhibited by 10^–5 M iso-OMPA but was resistant to 10^–5 M BW284 C 51, thus representing mainly non-specifc cholinesterase (nsChE) activity.The adrenergic nerves of the dorsal skin, as revealed by glyoxylic acid-induced fluorescence (GIF), were located in association with erector pili muscles and surrounded arteries and arterioles. Small fluorescent nerves were situated in subcutaneous nsChE-positive nerve trunks.Using GIF and cholinesterase techniques performed either simultaneously or consecutively, it was found that the nsChE-positive, probably sensory, nerves accompanying blood vessels were fewer in number than the fluorescent adrenergic nerves and ran a course independent of them. No cholinesterase reaction was seen in the fluorescent adrenergic nerves when short incubation times were used. When the incubation time was prolonged overnight, the nsChE reaction closely followed the course of fluorescent adrenergic nerves.     

Cholinesterase activity in Japanese quail dusted with carbaryl.

Japanese quail (Coturnix coturnix japonica) were dusted with 5% carbaryl to determine if this topical treatment would alter plasma and brain cholinesterase activities. Within 6 hours after dusting, plasma cholinesterase activity was depressed compared with controls, the depression averaging 20% for females and 27% for males. By 24 hours the cholinesterase activity of females had returned to normal, but the cholinesterase activity of males remained depressed. Brain cholinesterase activity was not affected by the treatment, and there were no overt toxic signs.     

Structural difference at the active site of dibucaine resistant variant of human plasma cholinesterase.

Human plasma cholinesterase from five different genotypes -- E1U E1U, E1U E1A, E1A E1A, E1U E1S, E1A E1S, and E1U E1U C5+ -- was purified 8,000 fold from serum by a two-step procedure involving chromatography on DEAE-cellulose and preparative disc electrophoresis. The esterases were labeled with diisopropyl-1, 3-C14-fluorophosphate (DFP) aminoethylated, and digested by trypsin. The trytic digests were subjected to high voltage electrophoresis, and the radioactive peptides were detected by radioautography. Comparison of the peptides revealed different electrophoretic mobilities of the usual and atypical (dibucaine resistant) plasma cholinesterase peptides. The results are consistent with a structural abnormality of the active center in the variant enzyme. No difference was observed an the esteratic site of the enzyme with C5 component.     

Altered donor and recipient Ly49+ NK cell subsets in allogeneic H-2d --> H-2b and H-2b --> H-2d bone marrow chimeras

NK cells reject non-self hematopoietic bone marrow (BM) grafts via Ly49 receptor-mediated MHC class I-specific recognition and calibration of receptor expression levels. In this paper we investigated how Ly49+ subset frequencies were regulated dependent on MHC class I expression. The development of donor and host Ly49A+ (recognizes H-2Dd and H-2Dk ligands) and Ly49C/I+ (Ly49CBALB/c recognizes H-2Kb, H-2Kd, and H-2Dd, and Ly49CB6 recognizes only H-2Kb) NK cell frequencies were monitored for 120 days in murine-mixed allogeneic BM chimeras. C57BL/6 (H-2b) BM was transplanted into BALB/c (H-2d) mice and vice versa. Peripheral NK cell populations were examined every 5 days. Chimerism was found to be stable with 80-90% donor NK cells. In contrast to syngeneic controls reexpressing pretransplant patterns, donor and host NK cells revealed new and mainly reduced subset frequencies 55 days after allogeneic transplantation. Recipient NK cells acquired these later than donor NK cells. In H-2d --> H-2b chimeras Ly49A+, Ly49C/I+, and Ly49A+/Ly49C/I+ proportions were mainly diminished upon interaction with cognate ligands. Also in H-2b --> H-2d chimeras, Ly49A+ and Ly49A+/Ly49C/I+ subsets were reduced, but there was a transient normalization of Ly49C/I+ proportions in the noncognate host. After 120 days all subsets were reduced. Therefore, down-regulation of developing Ly49A+ and Ly49C/I+ chimeric NK cell frequencies by cognate ligands within 7-8 wk after BM transplantation may be important for successful engraftment.     

Transferrin C subtypes and ethnic heterogeneity in Sweden

Transferrin (TF) C subtypes were studied in Swedish Lapps (Saami) and in Swedes from northern, central and southern Sweden, and the allele frequencies were compared with those in other European populations. The Swedish Lapps were found to have the lowest frequency of the TF*C3 allele (1-2%) so far observed in Europe. Most European populations have TF*C3 allele frequencies between 5 and 7%. Finns differ by having high TF*C3 frequencies (13-14%). The relatively high TF*C3 frequencies found in northeastern Sweden (13%) and in central Sweden (9%) are most likely due to eastern influence. Unlike other genetic markers of eastern influence (e.g. TF*DCHI), which are of Asiatic Mongoloid origin, TF*C3 appears to originate from Finno-Ugric populations.     

Apolipoprotein A1 gene polymorphisms at the -75 bp and +83/ 84 bp polymorphic sites in healthy Omanis compared with world populations

The relative frequencies of the *A allele of the APOA1 gene at -75 bp (M1-) and the C or T +83/+ 84 bp allele (M2-) varied significantly between populations. We found the frequencies of M1- and M2- to be 0.22 and 0.067, respectively, in 150 healthy Omanis. These frequencies were compared to frequencies found in other world populations.     

Biochemical characterization of the neuron. ATPase and acetylcholinesterase activities of neuronal cell bodies isolated in bulk from the pig brain stem.

Nerve cell bodies, large and multipolar, were isolated in bulk with the least possible contamination from the pig brain stem. The activities of two neurobiologically important membrane enzymes, Na+, K+-ATPase, and acetylcholinesterase, in the isolated cell bodies were estimated. Na+, K+-ATPase [EC 3.6.1.4], more accurately called ouabain-sensitive ATPase of the nerve cell body, hydrolyzed 94 micronmoles of ATP per h per 100 mg of protein. This activity was one-fourth that in the brain stem. Nerve cell bodies contained a large amount of Ca2+, 275 micronmoles per 100 mg of protein, about half of which was calculated to exist as compounds other than calcium orthophosphate. However, the Na+, K+-ATPase of the nerve cell bodies was not stimulated by EGTA, in contrast to that of the brain stem. Acetylcholinesterase [EC 3.1.1.7] and cholinesterase [EC 3.1.1.8] activities were estimated separately by the use of the specific inhibitors Persidol and BW 284C51 dibromide. Acetylcholinesterase was almost completely responsible for the hydrolysis of acetylcholine in the nerve cell bodies isolated from the brain stem and little cholinesterase activity was detected. 1300-1400 micronmoles of acetylcholine was hydrolyzed per h per 100 mg of protein of the neuronal cell bodies; this activity was about four times higher than that in the brain stem. The differences between the specific activities of Na+, K+-ATPase, and acetylcholinesterase in theneuronal cell bodies and the brain stem are discussed in the light of electron microscopic analysis of the distribution of these enzymes and the preservation of the plasma membrane of the isolated cell bodies.     

Molecular diagnosis and frequencies of primary hypolactasia in populations of RUSSIA and neighboring countries

The digestion of the milk sugar (lactose) is observed every normal child but not in every adult. The decreased lactase synthesis in some adults results in problems with digestion of the whole milk (primary hypolactasy). An association of lactase activity in adults with carrying of the allele T within the polymorphism C/T-13910 located upstream of the lactase gene and 100% association of hypolactasy with the genotype C/C has recently been shown for a Finnish sample. In the present work we determined the LCT* C/T_13910 genotypes and allele frequencies in populations from Russia. The genotype C/C frequencies varied from 36.6% for Russians to 88.2% for Chukchi and were close to the published medical and epidemiological data on hypolactasy frequencies in respective populations. Genotyping was performed by three different methods to identify the optimal one. Our results have shown that the studied locus is the key determinant for the primary hypolactasy development in various human populations. Consequently, the DNA diagnostics of the C/C genotype carrying is a promising predictive test to detect the primary hypolactasy long before its clinical development. Practical application of this type of diagnostics would be a step towards the individual-oriented medicine.     

Levels of plasma cholinesterase in Colombian working-class populations

Levels of plasma cholinesterase in Colombian working-class populations Reference values for plasma cholinesterase (EC 3.1.1.8) are not available for Colombian populations. A representative sample of a working-class population was used to establish these values to provide reference data for use by the social security system. Two working-class populations were sampled from the Aburrá Valley (Aburrá) and eastern Antioquia (Oriente). Cholinesterase activity was measured in 827 workers, with ages spanning 18-49 years, 415 from Aburrá and 412 people from Oriente. Three methods were used to measure cholinesterase: Michel, EQM and Monotest The average values by Michel and EQM were not statistically different between regions (Michel: Aburrá, 1.11, and East, 1.13 deltas pH/hora; EQM: Aburrá, 2.55, and Oriente, 2.48 U/ml). By the Monotest, the enzyme average was statistically higher in Aburra than in Oriente (5,743 and 5,459 U/L respectively; p = 0 .012). By region and technique, men had significantly higher enzymatic levels than women. Within both regions and sexes, no statistically significant difference among the three aged groups was noted. Our obtained Colombian values differed significantly from foreign reference values: Michel and Monotest levels were higher and EQM levels were lower. For making clinical and epidemiologic decisions in Colombia related to these data, the values obtained for the Colombian populations are preferred over values derived from external sources.     

A comparison of cholinesterase activity after intravenous, oral or dermal administration of methyl parathion

Time-dependent changes in blood cholinesterase activity caused by single intravenous, oral or dermal administration of methyl parathion to adult female rats were defined. Intravenous and oral administration of 2.5 mg/kg methyl parathion resulted in rapid (<60 min) decreases in cholinesterase activity which recovered fully in vivo within 30-48 h. In contrast, spontaneous reactivation of cholinesterase in vitro was complete within 6 h at 37 degrees C. Dermal administration of methyl parathion caused dose-dependent inhibition of cholinesterase activity which developed slowly (> or =6 h) and was prolonged (> or =48 h). Time- and route-dependent effects of methyl parathion on cholinesterase activity in brain and other tissues generally paralleled its effects on activity in blood. In conclusion, pharmacodynamics of methyl parathion differ substantially with route of exposure. Recovery of cholinesterase in vivo after intravenous or oral exposure may partially reflect spontaneous reactivation and suggests a rapid clearance of methyl parathion or its active metabolite methyl paraoxon. The more gradual and prolonged inhibition of cholinesterase caused by dermal administration is consistent with disposition of methyl parathion at a site from which it or methyl paraoxon is only slowly distributed. Thus, dermal exposure to methyl parathion may pose the greatest risk for long-term adverse effects.     

Study of red blood cell and serum enzymes in five Pyrenean communities and in a Basque population sample

Until recently, no data on genetic polymorphisms in the populations living on the northern side of the Pyrenees have been available, except for the Basques. Several investigations were done lately on rural communities in various geographic zones in the Pyrenees from the eastern to the western part. In this paper, the results for the following enzyme polymorphisms are reported: acid phosphatases, AK, ADA, PGM1 and PGM2, 6PGD, NADH diaphorase, SOD, MDH, TGP, G6PD, C5 esterase (E2 locus), serum cholinesterase (E1 locus). Significant variation in gene frequencies was observed over the distinct geographic zones for the main polymorphic system. Furthermore, some rare alleles were found: a new G6PD variant (Luz-Saint-Sauveur), the presence of ADA3 and ADA5 alleles in two groups of the Central Pyrenees, a Dia2 gene among Basques and in the Pays de Sault, a high rate of Ea1 allele in the Basque group. The values obtained for the degree of heterozygosity are in agreement with the relative isolation of the different groups studied and confirm the importance of sociocultural factors in the evolution of the genetic background of rural communities in Europe.     

Effect of acute hypoxia on the enzymes involved in the metabolic and nervous functioning of rat brain.

Rats were exposed to a simulated altitude of 25,000 ft for 4 h in a decompression chamber, and the activity of some tissue enzymes estimated. Succinate dehydrogenase activity was significantly decreased and cholinesterase activity significantly elevated in the brain homogenates of the hypoxic rats, succinic dehydrogenase activity was significantly increased. There was no change in the activity of Mg+2-ATPase and Na+-K+-ATPase in the microsomal fractions of liver or brain homogenates of the hypoxic animals.     

Effects of post-irradiation interval on translocation frequency in male mice

Hybrid male mice were given 5 Gy + 5 Gy acute X-rays 24 h apart, with cytological examination of testes 16-19, 39-42 and 64-66 weeks later. Mean testis weights were significantly lower in the youngest group than in the other two. However, translocation frequencies in spermatocytes of the youngest group (mean of 0.57 per cell) were significantly higher than in either of the other two groups, which gave similar values averaging 0.36 translocations per cell. There was highly significant heterogeneity in translocation yields within the youngest group. The decline in translocation yield with time after irradiation is in line with that reported by Léonard and Deknudt (1970) in inbred strain C57BL males. Analysis of all available data suggests that high translocation yields are found during late stages in the process of germ-cell repopulation of the testis after high radiation doses and may be connected with changing frequencies of radiosensitive and radioresistant stem cell populations as repopulation proceeds.     

Trypanosoma evansi: Cholinesterase activity in acutely infected Wistar rats

The aim of this study was to evaluate cholinesterase activity during the early acute phase of Trypanosoma evansi infection in rats. Fifteen male Wistar rats were randomly distributed into three groups (n = 5 animals per group): two trypanosome-infected groups (T3 and T5) and uninfected controls (C). The animals were inoculated intraperitoneally with 10⁶ trypanosomes. The blood was collected by cardiac puncture on the 3rd (T3) or 5th day post-infection (T5 and C). Cerebrum and cerebellum were removed for the evaluation of acetylcholinesterase (AChE) activity. AChE activity was also evaluated in whole blood and butyrylcholinesterase activity (BUChE) in plasma samples. Parasitemia were progressive increase and parasites were observed in the peripheral blood of all infected animals one day post-inoculation. AChE activity was not altered in cerebrum and cerebellum tissues. AChE activity in blood significantly decreased in the T3 and T5 groups (26.63 and 25.86 mU/l mol Hb) compared with the control (37.84 mU/l mol Hb). In addition BUChE activity in plasma was lower in the T3 (7.01 μmol BTC hydrolyzed/h/mL) than the T5 and C groups (9.84 and 12.00 μmol BTC hydrolyzed/h/mL). This study therefore, shows that reductions in the activity of cholinesterase occur in acute infection by T. evansi in rats and this demonstrates an important change occurring in animals infected by the protozoan and may indicate a potential role the enzymes play in the mechanism of disease.     

Plasma cholinesterase polymorphism in Down's syndrome.

The plasma cholinesterase variants in 80 patients having Down's syndrome have been examined and compared with a random control sample of individuals domiciled in the same area. Neither a change in frequency of known C5+ variant nor any new variant has been found in the electrophoretic studies. A highly significant increase in frequency of the fluoride resistant gene as well as a significant decrease in frequency of the atypical gene has been found in the Down's syndrome individuals. This altered distribution of the rare phenotype of plasma cholinesterase in mental illness may lead to a useful diagnostic acid in genetic counselling.     

Effect of food deprivation on histomorphology and cholinesterase activity of taste buds in ratst

The histomorphology and cholinesterase activity of the taste buds and the gustatory nerve fibre sin well-fed, in protein and protein-calorie deficient rats have been investigated. The nerve fibre arborisation in the taste buds is predominantly nonmyelinated and shows degenerative changes ranging from initial swelling to disintegration, fragmentation and finally complete disappearance with the increasing degree and duration of food deprivation. Coincident with these changes in the nerve fibre, the taste bud also shows various stages of degeneration. By contrast, the cholinesterase activity in the gustatory papillae shows an initial increase during the first week followed by a decline in the activity during the succeeding weeks; a second peak of cholinesterase activity appears during 4–6 weeks. The cholinesterase activity is barely detectable after the 8th week. In the more severely protein calorie restricted groups, the cholinesterase changes are more pronounced and abrupt in onset and show a total disappearance by 4–5 weeks.     

The C5 isozyme of serum cholinesterase and adult weight.

The relationship between the CHE2 locus of serum cholinesterase (BChE) and adult human weight was studied in a sample of 225 CHE2 C5+ individuals and 225 CHE2 C5- controls matched for sex, height, age and race. With respect to the intensity of the C5 band staining (scored 1-6), 113 individuals had faint C5 bands (scores 1-3) and 112 intense C5 bands (scores 4-6). The individuals with intense CHE2 C5+ phenotype showed a significantly lower mean adult weight (64.66 +/- 0.73 kg) when compared to their controls (70.59 +/- 0.97 kg) and a significant reduction in weight variance (59.81 and 105.18, respectively). Individuals with faint C5 bands, although showing a negative correlation between weight and C5 band intensity, did not differ from their controls in mean weight.     

Polymorphism of the HFE gene associated with hereditary hemochromatosis in populations of Russia

Expression of hereditary hemochromatosis as well as predisposition to iron overload syndrome and sporadic porphyria cutanea tarda are currently believed to be associated with the inheritance of certain allelic variants of the HFE gene. Allele frequencies of the C282Y (845A) and H63D (187G) mutations in the HFE gene in human populations of different races are remarkably different, and the prevalence of the S65C (193T) mutation is still poorly studied. In the present study we estimated allele frequencies of HFE mutations in Russians and in a number of Siberian ethnic indigenous populations. In Russians, allele frequencies of the C282Y, H63D and S65C mutations were 3.7, 13.3 and 1.7%, respectively. These values were similar to those observed in populations of Europe. The C282Y mutation was not detected in the population samples of Siberian ethnic groups, including Mansis, Khantys (Finno-Ugric group), Altaians, and Nivkhs (Mongoloids), suggesting that the frequency of this allele in the populations examined was lower than 1%. The frequency of the C282Y allele in the Tuvinian and Chukchi samples (Mongoloids) constituted 0.45 and 0.8%, respectively. Furthermore, pedigree analysis of both Chukchi carriers discovered showed that some of their ancestors were from other ethnic groups. Low frequencies of this allelic variant is typical of many Eastern Asian populations, which are also characterized by rather low frequencies of the H63D variant. In contrast, in some ethnic groups of Western Siberia allelic frequency of the H63D mutation is rather high, constituting 8.7% in Altaians, 15.5% in Mansis, and 11.3% in Khantys. The frequency of this allele in Tuvinians, Nivkhs, and Chukchis constituted 5, 4.7, and 0.8%, respectively. These findings make it possible to estimate the proportion of individuals predisposed to iron overload syndrome in different Russian ethnic groups. The HFE allele frequency distribution patterns observed in the populations examined pointed to pre-Celtic appearance of the CY82 allele. It also provides elucidation of the evolutionary genetic relationships between Siberian ethnic groups and the contemporary populations of Eastern and Western Europe.