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1.
Summary The question, Is Hb G Philadelphia linked to -thalassaemia? was first posed because the abnormal haemoglobin is found in heterozygotes at a concentration greater than 25%, the proportion predicted from a 4 -chain gene model. Globin chain biosynthesis was studied in a West Indian family in which one parent had + thalassaemia and the other was heterozygous for the G Philadelphia chain gene. The former had a globin chain production ratio / well above 1, while the latter had a ratio significantly less than 1. One child of the marriage had inherited the + thallassaemia from one parent and the G Philadelphia chain gene from the other and showed the typical picture of /-thalassaemia (/ ratio slightly above normal). It is explained in the discussion that the evidence favours a close linkage of 2 -chain genes.  相似文献   

2.
G. E. Marks 《Chromosoma》1965,16(6):681-692
Summary Phytophthora infestans has three kinds of somatic nuclei: an oval shaped nucleus (approx. 3.1×2.7 ) which stains diffusely except for a crescent shaped Feulgen positive cap which stains intensely; a granular nucleus whose contents are organized into a fairly constant number of stained bodies, and, a deeply staining condensed nucleus. The capped nucleus is thought to be metabolic or resting and the granular nucleus is thought to be dividing as it is most commonly found in hyphal tips. Attenuated forms of all three kinds of nuclei are found.Nuclear division is mitotic and intranuclear. Eight—ten chromosomes are seen at metaphase.Sporangia have a mean of 6.3 nuclei which is constant for age and strain of culture. Sporangia become multinucleate as a result of nuclear migration and not by division in the developing sporangium. Zoospores are usually uninucleate.The nuclear cap is persistent throughout nuclear division when it also divides. It is associated with flagella production and nuclear migration and has some of the properties of a blepharoplast.  相似文献   

3.
The structures of the N-linked sugar chains in the PAS-6 glycoprotein (PAS-6) from the bovine milk fat globule membrane were determined. The sugar chains were liberated from PAS-6 by hydrazinolysis, and the pyridylaminated sugar chains were separated into a neutral (6N) and two acidic chains (6M and 6D), the acidic sugar chains then being converted to neutral sugar chains (6MN and 6DN). 6N was separated into two neutral fractions (6N13 and 6N5.5), while 6MN and 6DN each gave a single fraction (6MN13 and 6DN13). The structure of 6N5.5, which was the major sugar chain in PAS-6, is proposed to be Man16 (Man13) Man14GlcNAc14GlcNAc-PA; 6N13, 6MN13 and 6DN13 are proposed to be Gal13Gal14GlcNAc12Man16 (Gal13Gal14GlcNAc12Man13) Man14GlcNAc14 (Fuc16)GlcNAc-PA;6M and 6D had 1 or 2 additional NeuAc residues at the non-reducing ends of 6MN13 and 6DN13, respectively. © 1998 Rapid Science Ltd  相似文献   

4.
Thirty-two West African dwarf goats were exposed to temperature treatments: 20, 25, 30, 35, 35, 35, 30, 25, 20°C each lasting three days.Sixteen goats were kept in individual pens (I), the others in two group pens (G). Heat production (HP) and activity were recorded during 48 hours in each temperature treatment.Mean HP and ME intake were similar for G and I animals, but I animals had lower values than G animals at low chamber temperatures and higher values than G animals at high temperatures. Upper critical temperature was between 25°C and 30°C under an increasing T and between 30 and 35°C under a decreasing T. Adaptation of heat production and ME intake to a change in temperature of 5°C required at least six and possibly more than nine days.Diurnal variation in HP was large, up to 44% between extremes. This was largely due to variation in activity.  相似文献   

5.
Summary Three different conformations of proline rings in a protein in solution, Up, Down and Twist, have been distinguished, and stereospecific assignments of the pyrrolidine -, - and -hydrogens have been made on the basis of 1H-1H vicinal coupling constant patterns and intraresidue NOEs. For all three conformations, interhydrogen distances in the pairs -3, 3-3, 2-2, 2-2, and 3-3 (2.3 Å) are shorter than those in the pairs -2, 2-3, 3-2, 2-3, and 3-2 (2.7–3.0 Å), resulting in stronger NOESY cross peaks. For the Up conformation, the 3-2 and 2-3 spin-spin coupling constants are small (<3 Hz), and weak cross peaks are obtained in a short-mixing-time (10 ms) TOCSY spectrum; all other vicinal coupling constants are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. For the Down form, the -2, 2-3, and 3-2 vicinal coupling constants are small, leading to weak TOCSY cross peaks; all other couplings again are in the range 5–12 Hz, and result in medium to strong TOCSY cross peaks. In the case of a Twist conformation, dynamically averaged coupling constants are anticipated. The procedure has been applied to bovine pancreatic trypsin inhibitor and Cucurbita maxima trypsin inhibitor-V, and ring conformations of all prolines in the two proteins have been determined.  相似文献   

6.
Immunocytochemical demonstration of protein kinase C (PKC) subspecies (, , ) was carried out in Pacinian corpuscles of rat hind feet using monoclonal or polyclonal antibodies against each of these subspecies. The inner core cells and lamellae and the Schwann cell cytoplasm of the nerve fiber innervating the corpuscle were strongly positive for PKC -immunoreactivity (IR). In contrast, the axon terminal and the outer core did not display any positive -IR. Very weak PKC -IR was detected in the ultraterminal region of the axon terminal, while the trunk region showed no immunoreactivity. Very faint PKC -IR was found also in the lamellar cells located at the periphery of the inner core and the endoneurial fibroblasts in the intermediate layer. PKC -IR was not detected in any part of the corpuscle. The strong PKC -IR in the inner core and the presence of absence of PKC -, -, and -IR in the axon terminal are discussed from the point of view of the functional aspects of each part.  相似文献   

7.
This report examines plasma amyloid proteins A40 and A42 and apolipoprotein E (apoE) levels and their relationships with age in non-demented older adults with (N = 32) or without the apoE-4 allele (N = 94). A levels did not differ between the groups whereas the 4 allele was associated with a significant reduction in plasma apoE. In subjects with the 4 allele, increasing age was associated with significant reduction in plasma A40. Subjects without the 4 allele showed a significant positive correlation between A40 and A42 levels. There was also a significant correlation between plasma A40 and apoE levels in all subjects.  相似文献   

8.
Pan XW  Xu HH  Liu X  Gao X  Lu YT 《Biotechnology letters》2004,26(22):1745-1748
Nitrate at 70m gave the highest biomass of Camptotheca acuminata in suspension culture in MS medium, but a NH4 +/NO3 molar ratio of 5:1 (giving a total of 40 m N) gave the maximum camptothecin yield. A two-stage flask culture system was established to improve culture efficiency; cell dry weight, camptothecin content and yield was increased by 30%, 280% and 340%, respectively when compared with those of control, reaching up to 36g l–1, 0.36mgg–1, and 12.8mgl–1, respectively.  相似文献   

9.
1,3-Fucosyltransferase solubilized from human liver has been purified 40 000-fold to apparent homogeneity by a multistage process involving cation exchange chromatography on CM-Sephadex, hydrophobic interaction chromatography on Phenyl Sepharose, affinity chromatography on GDP-hexanolamine Sepharose and HPLC gel exclusion chromatography. The final step gave a major protein peak that co-chromatographed with 1,3-fucosyltransferase activity and had a specific activity of 5–6 µmol min–1 mg–1 and anM r 44 000 deduced from SDS-PAGE and HPLC analysis. The purified enzyme readily utilized Gal1-4GlcNAc, NeuAc2-3Gal1-4GlcNAc and Fuc1-2Gal1-4GlcNAc, with a preference for sialylated and fucosylated Type 2 acceptors. Fuc1-2Gal1-4Glc and the Type 1 compound Gal1-3GlcNAc were very poor acceptors and no incorporation was observed with NeuAc2-6Gal1-4GlcNAc. A polyclonal antibody raised against the liver preparation reacted with the homologous enzyme and also with the blood group Lewis gene-associated 1,3/1,4-fucosyltransferase purified from the human A431 epidermoid carcinoma cell line. No cross reactivity was found with 1,3-fucosyltransferase(s) isolated from myeloid cells. Examination by Northern blot analysis of mRNA from normal liver and from the HepG2 cell line, together with a comparison of the specificity pattern of the purified enzyme with that reported for the enzyme expressed in mammalian cells transfected with theFuc-TVI cDNA, suggests a provisional identification ofFuc-TVI as the major 1,3-fucosyltransferase gene expressed in human liver.Died June, 1991  相似文献   

10.
Mild cerebral anoxic/ischemic/stress insults promote tolerance and thereby protect the brain from subsequent lethal anoxic/ischemic insults. We examined whether specific activation of PKC , , , or isoforms is associated with ischemic preconditioning (IPC) in rat brain. IPC was produced by a 2-minute global cerebral ischemia. Membrane and cytosolic fractions of the hippocampi were immunoblotted using specific antibodies for PKC, , , and . PKC showed a significant translocation to the membrane fraction from 30 min to 4 h and PKC at 4 h following IPC. In contrast, the membrane/cytosol ratio of PKC showed a tendency to decrease at 30 min and 8 h, and the membrane/cytosol ratio of PKC was significantly decreased from 30 min to 24 h following IPC. These findings indicate PKC isoform-specific membrane translocations in the hippocampus after brief global brain ischemia and suggest that activation of PKC and PKC may be associated with IPC-induced tolerance in the rat hippocampus.  相似文献   

11.
Summary In the present study, synaptic ribbons were studied morphologically and quantitatively in hamster pineal gland. The number of ribbons and spherules of hamster pinealocytes was counted over a 24-h period. The 24-h variations in the quantity of synaptic ribbons were found to parallel fluctuations in pineal melatonin concentrations. No significant circadian changes were observed for synaptic spherules, indicating different roles for these two structures.  相似文献   

12.
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   

13.
Summary Vicia faba callus line (VFS 1), isolated from expiants of immature embryo, grew satisfactorily onMurashige andSkoog complete medium with 1.38 M 2,4-D, or with 0.92 M 2,4-D to which 1.0 M kinetin was added. It also grew well on the B 5 modified medium containing 2.3 M 2,4-D and 25.0 M kinetin. On the last of these media the cultures grew more uniformly and without necrosis. They also showed diminishing variation in polyploidy in favour of diploids and corresponding aneuploids (hypodiploids).After being cultured for nearly three years on MS containing 1.38 M 2,4-D, 8–33% of cultures of VFS 1 were able to regenerate roots when transferred to either MS half strength with 5.37 M NAA, or to a medium without 2,4-D, or else to media with the addition of kinetin only (in various concentrations).  相似文献   

14.
Molecules of deoxyribonucleic acid and synthetic polydeoxyribonucleotides (NA) in the particles of liquid-crystalline dispersions resulting from interaction with chitosan are accessible to interaction with intercalators. The intercalation is accompanied by alteration in the direction of spatial twist of cholesterics of NA–chitosan complexes. This effect is absent in the case of classical cholesterics produced from NA molecules via phase exclusion, i.e., the cholesteric structure of NA–chitosan complex is very labile as distinct from classical cholesteric NA.  相似文献   

15.
Petitpierre E  Garnería I 《Genetica》2003,119(2):193-199
The chromosomes of ten species of Cyrtonus and the genome sizes of six are surveyed. Among the total of 15 chromosomally studied species, 11 have 2n=28 chromosomes and a 13+Xyp male meioformula, three have 2n=40 and 19+Xyp and one 2n=46 and 22+Xyp. All but one species with 28 chromosomes show only metacentric or submetacentric chromosomes, whereas the species with 40 and 46 chromosomes display some telocentrics or subtelocentrics, that are probably derived from the former by centric fissions. However, since the number of major chromosome arms is strikingly higher in these latter species (NF=70 and 78) than in the 28-chromosome species (mostly NF=56), other chromosomal rearrangements such as pericentric inversions or heterochromatin accretions could also be involved. The genome sizes display a narrow range, from 1C=0.6–1.22pg, and they are not significantly correlated with the chromosome numbers. Some possible factors implied in the rough chromosomal evolution of Cyrtonus are discussed in relation to a few other genera of the subfamily Chrysomelinae.  相似文献   

16.
O. Kiermayer  U. B. Sleytr 《Protoplasma》1979,101(1-2):133-138
Summary Cells ofMicrasterias denticulata Bréb. at the stage of secondary wall formation have been studied by freeze-etching. It was found that the plasma membrane exhibits oval areas in which arrays of membrane particles occur. These particles form rosettes which are arranged in a hexagonally ordered lattice with a center to center spacing of 25 nm. Nearly the same periodicities can be found between microfibrils. It is concluded that the rosettes probably together with the thickened area of the plasma membrane below them represent the apparatus for the production and orientation of microfibrils. The hypothesis suggesting the incorporation of membrane templates functional in microfibril formation, originally advanced byKiermayer andDobberstein (1973) has received further support.  相似文献   

17.
The rat pheochromocytoma PC12 cell line, which differentiates into sympathetic neurons under nerve growth factor (NGF) treatment, contains at least three phosphoinositidase C (PIC) isozymes, PIC , PIC , PIC . These isozymes have been previously shown to display a different subcellular localization. To determine whether or not NGF induces changes in the presence and/or distribution of PIC isozymes during PC12 neural differentiation, studies were carried out by means of in situ immunocytochemistry. After NGF administration the proliferative activity was progressively reduced to very low levels, as measured by bromodeoxyUridine incorporation, and a neuron-like morphology was displayed by almost all cells. In unstimulated PC12 cells, PIC was detected in the nucleus whereas PIC was only cytoplasmic; PIC was found in both cell compartments. In cells treated with NGF for 3 days, neural processes extended to twice the diameter of the cell body; the isoform was concentrated near the nucleus, while the immunoreactivity of the form remained constant and the form was increased. After 10 days of treatment with NGF, PIC was hardly detectable and PIC immunostaining was considerably decreased. On the contrary, PIC progressively increased and, after 14 days of NGF exposure, fully differentiated cells displayed an intense labelling of cell body and neurites. In the same cells, PIC and PIC were almost negative. These results suggest that NGF dependent neural differentiation is related to the selective down regulation of PIC and and the increase of PIC isozyme associated with the decrease of cell proliferation.  相似文献   

18.
The psychological side effects of self-regulatory treatment (a combination of relaxation, thermal biofeedback, and cognitive therapy) for irritable bowel syndrome (IBS) were compared among 20 successfully treated patients, 12 unsuccessfully treated patients, and 9 patients who merely monitored symptoms for 12 weeks. Pretreatment and posttreatment scores on the Beck Depression Inventory, State-Trait Anxiety Inventory, and Psychosomatic Symptom Checklist were examined. Successfully treated patients had significant (p<.01) reductions on all measures and significantly greater reductions on depression and state anxiety than the symptom monitoring group. Interestingly, the failures also showed a significant (p=.027) reduction in trait anxiety and no significant increases on other measures.  相似文献   

19.
Expression of a chimeric stilbene synthase gene in transgenic wheat lines   总被引:11,自引:0,他引:11  
A chimeric stilbene synthase (sts)gene was transferred into wheat. Stilbene synthases play a role in the defence against fungal diseases in some plant species (e.g. groundnut or grapevine) by producing stilbenetype phytoalexins like resveratrol. Resveratrol is also claimed to have positive effects to human health. Embryogenic scutellar calli derived from immature embryos of the two commercial German spring wheat cultivars Combi and Hanno were used as target tissue for cotransformation by microprojectile delivery. The selectable marker/reporter gene constructs contained the bargene either driven by the ubiquitinpromoter from maize (pAHC 25, also containing the uidAgene driven by the ubiquitinpromoter), or by the actinpromoter (pDM 302) from rice. The cotransferred plasmid pStil 2 consisted of a grapevine stscoding region driven by the ubiquitin promoter. Eight transgenic Combi and one Hanno TOplant were obtained and, except one Combi TOplant, found to be cotransformants due to the integration of both the stsgene and the selectable marker or reporter genes. Expression of the stsgene was proven by RTPCR, and, for the first time, by detection of the stilbene synthase product resveratrol by HPLC and mass spectrometry. The stsgene was expressed in four of the seven transgenic Combi T_oplants. Two of the respective T1progenies segregated in a Mendelian manner were still expressing the gene. Investigations into methylation of the stsgene showed that in three nonexpressing progenies inactivation was paralleled by methylation.  相似文献   

20.
Summary 1. The cellular resistance of representatives from four euryhaline poikilosmotic bivalves caught in Büsum (North Sea, 30 S), Kieler Förde (Belt Sea, 15 S), and Tvärminne (Gulf of Finland, 6 S) has been tested. All experiments were performed in October.2. According to their cellular salinity rangesMacoma baltica andMytilus edulis are more euryhaline thanMya arenaria andCardium edule.3. The cellular heat resistance decreases in specimens from the North Sea in the following order:Cardium, Mya, Macoma, Mytilus. Among the representatives collected near Tvärminne,Macoma has the highest heat resistance.4. The cellular freezing resistance in specimens from the North Sea is highest inMytilus. The bivalves of the Gulf of Finland practically lack resistance to freezing.5. In localities of decreased salinity the cellular resistance of these bivalves to a dilution of the external medium is somewhat increased, but simultaneously the cellular resistance to other environmental factors, such as heat, freezing and high salinity, decreases unspecifically.
Vergleichende Untersuchungen über zelluläre Resistenz bei Muscheln aus Meer- und Brackwasser
Kurzfassung An vier euryhalinen poikilosmotischen Muschelarten aus Büsum (Nord-seeküste, 30 S), der Kieler Förde Beltsee, 15 S) und Tvärminne (Finnischer Meerbusen, 6 S), wurden zur gleichen Jahreszeit (Herbst) vergleichende Untersuchungen über die zellulären Resistenzgrenzen durchgeführt. Auf Grund ihrer zellulären Salzgehaltsbereiche sindMacoma baltica undMytilus edulis euryhaliner alsMya arenaria undCardium edule. Die zelluläre Hitzeresistenz nimmt bei den Individuen aus der Nordsee in der Reihenfolge:Cardium, Mya, Macoma, Mytilus ab. Bei Exemplaren aus Tvärminne ist die zelluläre Hitzeresistenz vonMacoma am größten. Die zelluläre Gefrierresistenz ist unter den Muscheln aus der Nordsee am größten, fehlt dagegen praktisch bei den Tieren aus dem Finnischen Meerbusen. Bei verringertem Salzgehalt des Fundortwassers ist die zelluläre Resistenz der untersuchten Muscheln gegenüber Verdünnung des Außenmediums jeweils etwas erhöht, gleichzeitig nimmt die zelluläre Resistenz gegenüuber anderen Außenfaktoren wie Hitze, Frost und hohen Salzkonzentrationen unspezifisch ab.


Dedicated to Professor Dr.Friedrich Krüger on his 65th birthday, August 18, 1967.  相似文献   

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