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1.
Summary Chemiluminescence, indomethacin-sensitive suppression, and adherent cell cytotoxicity were measured in peripheral blood mononuclear cells (PBMC) from normal subjects and solid tumor cancer patients. These functions were found to be differentially affected by malignant disease. In cancer patients with disseminated disease, indomethacin-sensitive suppression and chemiluminescence emission were increased to a level significantly higher than normal without a concurrent increase in adherent cell cytotoxic function. In cancer patients with at most minimum residual diseases, the levels of chemiluminescence, indomethacin-sensitive suppression, and adherent cell cytotoxicity found were comparable to those of the normal study population. In vitro stimulation of cells from patients with disseminated disease by phorbol myristic acetate (PMA) increased chemiluminescence overcame the suppressive effects of indomethacin-sensitive suppressor cells, and increased adherent cell cytotoxicity; in cells from patients with at most minimum residual disease, PMA increased chemiluminescence and cytotoxicity without influencing the activity of indomethacin-sensitive suppressor cells. Vaccination of lung cancer patients with Freund's complete adjuvant or Freund's complete adjuvant plus tumor antigen extracts led to increased levels of chemiluminescence and increased levels of adherent cell cytotoxicity without altering indomethacin-sensitive regulatory cell function.  相似文献   

2.
The enhanced expression of the RI subunit of cyclic AMP-dependent protein kinase type 1 (PKA-I) has been correlated with cancer cell growth. We have investigated the effects of sequence-specific inhibition of RI gene expression on the growth of MCF-7 human breast cancer cells. We report that RI antisense treatment results in a reduction in RI expression at both mRNA and protein levels and inhibition of cell growth. The growth inhibition was accompanied by changes in cell morphology, cleavage of poly(ADP-ribose) polymerase (PARP) and appearance of apoptotic nuclei. In addition, bcl-2 protein level was reduced and p53 expression increased in growth arrested cells. Interestingly, RI antisense inhibited cell viability and induced apoptosis in the absence of p53, suggesting that these actions of RI antisense are exerted independent of p53. In contrast, two- and four-base mismatched control oligonucleotides had no effect on either cell growth or morphology. These results demonstrate that the RI antisense, which efficiently depletes the growth stimulatory molecule RI, induces cell differentiation and apoptosis, providing a new approach to combat breast cancer cell growth.  相似文献   

3.
The life cycle of Daphnia commonly includes parthenogenesis, sexual reproduction, and diapause. Although there are no genotypic transformations during diapause, it separates the clonal and pseudopanmictic states of the population. During parthenogenetic reproduction primarily polymorphic natural populations gradually degenerate into a mixture of a few clones. As resting eggs are usually produced sexually (= by means of sexual reproduction), after the diapause the vast diversity of individual genotypes normal for panmictic populations is observed. It is the competitive interactions between parthenogenetic clones which again eventually decrease the genotypic polymorphism. Forms in which the sexual process and diapause are rare (or species which are represented by parthenogenetic populations in one part of their area and by bisexual ones in another) demonstrate the most significant differences between clonal and panmictic populations.Parthenogenesis, apomixis and other kinds of reproduction without genetic recombination are widely spread in branchiopod crustaceans (Notostraca, Anostraca, Conchostraca, Cladocera) and in many other animals and plants. Moreover, reproduction without recombination plays an important role in evolution of faunas and floras. It is emphasized that non-recombinating races and species having high heterozygosity but a low level of genetic variation, enjoy short term advantages, but die out after change in the environment.  相似文献   

4.
Summary The generation of lymphokine-activated killer (LAK) activity and the proliferative response to human recombinant interleukin-2 (IL-2) were significantly reduced by the presence of human recombinant leukocyte interferon (IFN) in cultures of human peripheral blood mononuclear cells (PBMC). Mature natural killer (NK) cells can be depleted from PBMC with the toxic lysosomotropic agentl-leucine methyl ester. The generation of cytotoxic cells from lymphocytes depleted in leucine methyl ester was also inhibited by indicating that the IFN- effect is not limited to mature cytotoxic NK cells. Depletion of adherent cells from PBMC did not affect the suppression of LAK induction by IFN-. Surface marker analyses of Tac antigen and transferrin receptor (TfR) showed that the presence of IFN throughout the culture period significantly suppressed the typical increase in IL-2-induced Tac- and TfR-positive cells. In contrast, IFN treatment before and after IL-2 culture enhanced LAK cytotoxic activity. Therefore, combinations of these biological response modifiers for clinical use should take into account the dual effect of IFN on key features of the IL-2 response.This work was supported in part by USPHS grant CA34442. Y. T. is a UCLA visiting scientist from the Department of Surgery, School of Medicine, Tokai University, Kanagawa, Japan and recipient of a fellowship from the University of California Cancer Research Coordinating Committee. N. E. is a UCLA visiting scientist from the Department of Surgery, School of Medicine, Tohoku University, Sendai, Japan  相似文献   

5.
Summary Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant genetic disease characterized by systemic accumulation of amyloid fibrils. A major component of FAP anyloid has been identified as variant transthyretin (TTR, also called prealbumin). In particular, a variant with the substitution 30ValMet has been commonly found in FAP of various ethnic groups. To understand the origin and spread of the ValMet mutation, we analyzed DNA polymorphisms associated with the TTR gene in six Japanese FAP families and several Portuguese FAP patients. Three distinct haplotypes associated with the ValMet mutation were identified in Japanese FAP families, one of which was also found in Portuguese patients. On the other hand, it was found that the ValMet mutation can be explained by a C-T transition at the CpG dinucleotide sequence of a mutation hot spot. Thus, our findings indicate that the ValMet mutation has probably recurred in the human population, to generate FAP families of independent origin.  相似文献   

6.
Thidiazuron substitution for chilling requirement in three apple cultivars   总被引:2,自引:0,他引:2  
Thidiazuron [(TDZ)N-phenyl-N-1,2,3-thidiazol-5-ylurea] at 750 M was applied to buds of apple trees to determine if it could substitute for the chilling requirement to induce bud break. Shoots of cv. Anna (low chill), Delicious cv. Redchief (medium chill), and Northern Spy (high chill) were untreated, treated with TDZ prior to chilling (before-chill), and treated with TDZ at various intervals after the accumulation of specific amounts of chilling (after-chill). Shoots were stored in a cold room at 4°C. TDZ applied prior to chilling reduced the chill unit (CU) requirement (1 CU = 1 h at 4°C) for the promotion of bud break on 1-year-old shoots of Anna and Northern Spy and 1- and 2-year-old wood of Delicious. TDZ applied after-chill promoted bud break only for Anna and buds on 2-year-old wood of Delicious. While accumulating CUs, untreated buds or buds treated with TDZ on 1-year Delicious and Northern Spy did not respond to the cold treatment even after 1848 h of CU accumulation. For all three cultivars, TDZ treatment was more effective in promoting bud break when applied before the initiation of chilling.The use of a company or product name does not constitute an endorsement by USDA or the University of Maryland nor imply approval to the exclusion of other suitable products.  相似文献   

7.
Summary Growth of and of some lambdoid phages is considerably inhibited on strain 3057 derived from E. coli 15T-. Mutants of which overcome this inhibition map in gene N. Some of these hty mutants are temperature sensitive for growth on E. coli K12. Thus plating of on strain 3057 allows one to isolate temperature sensitive N mutants. The hty mutants produce less than normal N activity as judged by their low efficiency of plating on a nus - host and by the extended latent period of some of them on normal hosts. The inability of strain 3057 to propagate can be at least partially reversed by addition of thymidine to the medium and the growth difference between hty and in 3057 increases with decreasing thymidine concentration. The amount of DNA produced by in 3057 at low thymidine concentration is lower than that produced by hty under the same conditions. Only a small percentage of the DNA produced by in 3057 is packaged into viable phage particles. This suggests that not only produces less DNA in 3057 than hty but that an important part of the DNA in 3057 is in a form which can not be packaged or which is noninfective for other reasons. A hypothesis is discussed that hty mutations enable to grow on E. coli 15T- at low thymidine concentration because they lead to reduction in the number of single strand nicks in the DNA by reducing the intracellular endonuclease activity. Under permissive conditions conditional lethal N mutants are favored for growth on 3057 over N + which confirms the idea that N activity or the activity of a gene under N control interferes with growth in 3057 at low thymidine concentration.  相似文献   

8.
Summary 3 families with hereditary angioedema in 9 members are described. The serum concentrations of complement factors C3, C4, and C-inhibitor (CINH) were determined in all available family members. C inhibiting activity was characteristically low or absent in sera from patients. CINH and C4 concentrations were also low, whereas C3 was present in normal concentrations in patients and in unaffected family members. In all 3 families fatal attacks of laryngeal edema had occured. 4 individuals, 2 children and 2 adults, had low concentrations of CINH and C4 but had never experienced symptoms of angioedema.
Zusammenfassung 3 Familien mit hereditärem Angioödem bei insgesamt 9 Mitgliedern werden beschrieben. Die Serumkonzentrationen der Komplementfaktoren C3, C4 und des C-Inhibitors (CINH) wurden bei allen erreichbaren Familienmitgliedern bestimmt. Die C-Hemmaktivität und die Konzentrationen von CINH und C4 waren in den Patientenseren niedrig. Der C3-Serumspiegel war jedoch bei Patienten und gesunden Familienmitgliedern normal. In allen 3 Familien sind tödlich verlaufende Anfälle von Larynxödem vorgekommen. 4 Familienmitglieder, 2 Kinder und 2 Erwachsene, waren trotz niedriger Serumkonzentrationen von C4 und CINH asymptomatisch.


Supported in part by Deutsche Forschungsgemeinschaft.  相似文献   

9.
Summary Gene dosage studies yielded results consistent with assignment of the locus for nucleoside phosphorylase to band 14q13. The red blood cells from a patient with the karyotype 47,XX,+der(14),t(8;14)(8qter8q24: :14q2114pter)pat had enzyme activity 50% higher than red cells from 47 normal controls, two trisomies involving chromosomes other than 14, and five balanced translocations involving chromosome 14. On the other hand, the red cells of a case with a karyotype 45,XX,-14,-22,+der(22),t(14;22)(14qter14q11 or 14q12::22p1122qter)mat and a case with a karyotype 47,XX, +der(14),t(14;16)(14pter14q11::16q2416qter)mat had normal activity.  相似文献   

10.
Summary Genetic analysis for leaf rust reaction of two widely adapted cultivars, Sonalika and WL 711, has been done using 21 near isogenic Lr lines and rust culture IL004 — avirulent on the two cultivars and all the Lr lines used. The segregation pattern in the F2 generation indicated the presence of a recessive gene in Sonalika and of a dominant gene in WL 711. These genes in cultivars Sonalika and WL 711 have been identified as Lr 11 and Lr 13, respectively. Gene Lr 13 is no longer effective in WL 711 but it continues to give field resistance in the backgrounds of Chris, Prelude and Thatcher. There has been no significant change in the virulence spectrum of the leaf rust pathogen in India with the release of WL 711. High susceptibility of WL 711 seems to be due to the evolution of more aggressive forms of the pathogen to this cultivar. The gene Lr 11, which behaves as a recessive in Sonalika, was effective against leaf rust when this cultivar was released. The high susceptibility of Sonalika is probably due to an increase in the frequency of race 77 virulent on Lr 11. Lr 11 has shown a dominance reversal in the background of Sonalika. Present results suggest that interaction of resistance genes with the background genotype must be studied for their effective use in breeding programme.  相似文献   

11.
The inheritance of host plant resistance and its effect on the relative infection efficiency for leaf blast was studied in the crosses IR36/CO39 (partially resistant × highly susceptible) and IR36/IR64 (both partially resistant). On the natural scale, gene action appeared multiplicative. After log transformation, additive effects described most of the genetic variation in the cross IR36/CO39, while additive and dominance effects were about equal in magnitude in the cross IR36/IR64. Dominance was towards increased resistance. No transgressive segregation occurred in the cross IR36/CO39. The number of genes that reduce lesion number was estimated to be zero in CO39 and five or more in IR36. The cross IR36/IR64 showed transgressive segregation in both directions, and IR36 and IR64 each contain at least one gene that is not present in the other cultivar. The heritabilities (narrow sense) in the F2 were low (range 0.06–0.16), while narrow sense heritabilities based on F3 lines were much higher (range 0.41–0.68). Lesion numbers in F3 lines were reasonably correlated with those in F5 progenies derived from the same F2 plant (r was±0.6 in both crosses). Partial resistance can be effectively improved by selecting the most resistant plants from the most resistant F3 lines.  相似文献   

12.
One thousand and ninety-two poplars were regenerated in vitro from callus of 13 poplar clones representing the Leuce, Aigeiros and Tacamahaca sections. At lest 44 of the regenerants differed in some way from the original clones. Somaclonal variation occurred more frequently in poplars of the Leuce section (8%) than in those of the Aigeiros or Tacamahaca sections (1%). Variation was noticed in growth habit, leaf shape or indentation but not in the reaction to four Melampsora races. However, after one growing season in the field, a few regenerants from calli of two clones (Ogy and Rap) differed in their susceptibility vis à vis the original clones. Cultivation of callus from Leuce poplars that had survived exposure to increasing concentrations of toxins from Hypoxylon mammatum gave rise to a toxin-tolerant line from which toxin tolerant plants were regenerated. Flow cytometry to measure the DNA content of nuclei showed that regenerants tended to be tetraploid.Abbreviations NAA naphthaleneacetic acid - BAP benzylaminopurine - TDZ thidiazuron - MS Murashige & Skoog medium  相似文献   

13.
The role of -tocopherol uptake system in human erythrocyte in the uptake of plasma -tocopherol has been suggested. However no information is available on -tocopherol uptake activity of human erythrocytes in the presence of high levels of D-glucose which is known to lead to pathological alterations in different cells including human erythrocytes. Therefore, in order to examine the effect of D-glucose on the binding of -tocopherol to human erythrocytes, the binding characteristics of -tocopherol to these cells were established first. Binding of [3H]-tocopherol to human erythrocytes was both saturable and specific. Scatchard analysis of -tocopherol binding to these cells showed the presence of two independent classes of binding sites with widely different affinities. The high affinity binding sites had a dissociation constant (Kd1) of 90 nM with a binding capacity (n1) of 900 sites per cell, whereas the low affinity binding sites had a dissociation constant (Kd2) of 5.2 M and a binding capacity (n2) of 105,400 sites per cell. Trypsin treatment abolished all the -tocopherol binding activity. Competition for the binding of -tocopherol to human erythrocytes was effective with other homologues of -tocopherol (-tocopherol, -tocopherol and -tocopherol) and their potency was almost equal to -tocopherol itself. The order of preference was -tocopherol > -tocopherol -tocopherol -tocopherol. Incubation of human erythrocytes with various concentrations of D-glucose did not affect -tocopherol uptake activity. Our data demonstrate the presence of an -tocopherol uptake system in human erythrocytes and that the -tocopherol uptake activity is not modulated by the presence of D-glucose.  相似文献   

14.
Summary Chris wheat possessed genes Sr5, Sr7a, Sr8a, Sr9g and Sr12. W3746, derived from the cross Chris/Baart, possessed Sr7a and Sr12. The response conferred by Sr7a was influenced by the genetic background. Although Sr7a or Sr12 alone conferred no observable resistance upon adult plants, the adult resistances of Chris and W3746 to predominant pathotypes appeared to be associated with the interaction of Sr7a and Sr12, or genes at closely linked loci.  相似文献   

15.
The amounts of a 160-kDa amylase and a 140-kDa -amylase (A. Burgess-Cassler and S. H. Imam, Curr. Microbiol. 23:207–213, 1991) secreted into culture medium by the starchutilizingLactobacillus amylovorus were enhanced by the use of cyclodextrin (CD) as the carbon source. The levels of total extracellular -amylase obtained with glucose as the carbon source could be boosted severalfold by use of CD. The best enhancer was -CD, and the rank order of best to least effective was -CD>-CD=-CD>glucose.Another amylase, a 65-kDa -amylase, which degraded para-nitrophenyl-(1,4)-d-glucopyranoside, was also detected in this study. The most effective enhancer in this case was -CD, and the rank order was -CD>-CD>-CD glucose. Despite its ability to degradep-nitrophenylated glucose, this enzyme did not convert maltose to glucose. It showed a cleared zone on starch zymograms and did degrade short maltodextrins to maltose. Neither this new -amylase nor the 140-kDa -amylase exhibited any detectable ring-decyclizing (cyclodextrinase) activity against -or -CD.Other extracellular amylases (not characterized here) appeared to be similarly enhanced by CDs. Although the precise mechanism by which this effect is accomplished remains undefined, CDs can be useful inducing agents, boosting the expression and/or secretion of otherwise low-level enzymes, either as additives to growth media or as sole carbon source.  相似文献   

16.
Pelobacter acidigallici is a strictly anaerobic bacterium that ferments trihydroxybenzenes to 3 mol acetate/mol substrate. The key intermediate linking the catabolic sequences to the formation of cell matter is acetyl-CoA. Since P. acidigallici is independent of further external electron donors, it must oxidize part of the acetyl-CoA to provide reducing equivalents for anabolism. In this study we demonstrate the presence of all enzymes necessary to operate a modified citric acid cycle, with activities sufficient to support growth. Unusual enzymes in the cycle are 2-oxoglutarate synthase and succinyl-CoA: acetoacetate CoA transferase. Anaplerotic reactions are catalyzed by pyruvate synthase, PEP synthetase and PEP carboxylase. No CO dehydrogenase, hydrogenase, or formate dehydrogenase activity could be detected. The phylogenetic implications of these findings with respect to the relatedness of P. acidigallici to gramnegative, sulfur-reducing bacteria by 16 S rRNA cataloguing are discussed.Abbreviations CoA coenzyme A - DCPIP 2,4-dichlorophenolindophenol - DTNB 5,5-dithiobis(2-nitrobenzoic acid) Ellman's reagent - DTT 1,4-dithiothreitol - methyl viologen 1,1-dimethyl-4,4-bipyridinium dichloride - PEP phosphoenolpyruvate - PMS phenazin methosulfate - Tricine N-[tris(hydroxymethyl)-methyl]-glycine - Tris tris(hydroxymethyl)aminomethane  相似文献   

17.
The angle CH,NHN subtended by the internuclear vectors 13C-H and 15N-HN in doubly-labeled proteins can be determined by observing the effect of cross-correlation between the dipolar interactions on zero- and double-quantum coherences involving 13C and 15N. Two complementary 2D experiments with the appearance of 15N-HN correlation spectra yield signal intensities that depend on the rate of interconversion through cross-correlated relaxation of in-phase and doubly antiphase zero- and double-quantum coherences. The ratio of the signal intensities in the two experiments bears a simple relationship to the cross-correlation rate, and hence to the angle CH,NHN. Assuming planarity of the peptide bond, the dihedral angle (between C and C) can be determined from the knowledge of CH,NHN. The experiments are very time-effective and provide good sensitivity and excellent spectral resolution.  相似文献   

18.
The population dynamics of Daphnia hyalina Leydig in a productive lake, Esthwaite Water, and an unproductive lake, Buttermere, in the English Lake District have been compared. The winter is passed as resting eggs in the bottom sediments in Buttermere and as free-swimming individuals in the planktonic zone in Esthwaite Water. In Esthwaite Water seasonal periodicity was characterised by maxima in spring and autumn and a minimum in summer; in Buttermere, there was no spring maximum and the first increase in population density was in summer. Population densities were higher and adult females were larger and laid more eggs per clutch in Esthwaite Water than in Buttermere. In each lake males became numerous in autumn. Observed rates of population increase, r and calculated birth rates, b and death rates d were nearly always higher in Esthwaite Water than in Buttermere.  相似文献   

19.
The aerobic nitrogen-fixing unicellular cyanobacteriumSynechococcus RF-1 (pcc 8801) contains numerous irregular polyglucan granules ranging in size from 0.1 to 0.4 m. These morphologically unusual polyglucan granules are not found in the sheathed nitrogen-fixing unicellular cyanobacteriumGloeothece RF-6 (pcc 8803). Two forms of -amylase, ethyleneglycolbis-(-aminoethyl ether)-N,N,N,N-tetraacetic acid (EGTA)-sensitive and EGTA-insensitive, were found in theSynechococcus RF-1. In addition to their EGTA sensitivity, the two forms of -amylase also differed in their reactive pH range and in their zymogram disc gel electrophoresis. Each form of -amylase was stable and constant in concentration through a diurnal light/dark cycle.  相似文献   

20.
The concept of final preferendum is reexamined in light of data concerning acclimation in a cyclic thermal regime. Because of Shuttling behavior to temperatures above and below the mean preferendum, and because of faster acclimation upward than downward, which result in acclimation to a temperature exceeding the mean of the cycle, a fish may finally gravitate to a preferendum which does not equal acclimation temperature. It is suggested that a distinction be made between the crossover-point preferendum, where preference and acclimation are equal, and the ultimate preferendum to which a fish will ultimately gravitate.  相似文献   

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