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1.
Biochemical characteristics, O1 antigen factors and phage patterns were examined in 35 urinary O1K1 isolates ofEscherichia coli different in H and F antigen. Fermentation of dulcitol, decarboxylation of ornithine, requirement for nicotinamide, and determination of O1 factor d allowed maximum differentiation. On the basis of these tests the strains could be divided into two major groups which are obviously of different clonal origin. Members of clone 1 represented by serotypes O1K1H7F11 (12 strains) and O1K1HF11 (5 strains) were characterized by positive biochemical reactions and absence of O1 antigen factor d. Negative biochemical tests and presence of O1 antigen factor d were shown by strains of clone 2 which were of serotypes O1K1HF9 (14 strains) and O1K1HF (3 strains). Phage patterns are less well correlated with clonal assignment. However, strains of clone 2 were not susceptible to K1-specific phage D and were non-typable with another set of 13 phages.  相似文献   

2.
106 enterotoxigenicEscherichia coli strains from children and adults from many parts of the world were serotyped for O and H antigens. Some OH types,i.e. O6H16, O8H9, O15H11, O25H42, O78H11 and O78H12, were found repeatedly from different geographical locations. Some of these OH serotypes were only found rarely among more than 20000E. coli strains collected over many years from different locations and sources. It is suggested that these special OH serotypes represent clones which have been selected to the special conditions in the small intestine and selected to carry the plasmids necessary to provoke diarrhoea.  相似文献   

3.
Aerobactin production was examined by a bioassay in 467 Escherichia coli urinary strains from girls. All strains were of known OKH serotype. 139, 119 and 112 strains were isolates from pyelonephritis (Py), cystitis (Cy) and asymptomatic bacteriuria (ABU), respectively, and 97 were from fecal samples of healthy girls (FN). The incidence of aerobactin production was significantly higher among Py strains than among ABU and FN strains (P<0.001) and also significantly higher than among Cy strains (P<0.01). Aerobactin production was associated with serotype, e.g. the majority of 06K2H1 strains and of 016K1H6 were positive while e.g. the 06K13H1 strains were negative. There was no consistent pattern of coappearance of aerobactin and hemolysin.  相似文献   

4.
During the development of mammalian muscle the -subunit of the nicotinic acetylcholine receptor (AChR) is replaced by the -subunit to produce well-defined alterations in the conductance and gating of the channel. To gain a better unterstanding of the functional role of the and -subunits, we have studied the properties of an AChR channel lacking these subunits. The AChR expressed in Xenopus oocytes injected with the bovine -, and -subunit-specific mRNAs (referred to as -AChR) is unusual in that its channel opens spontaneously at a high frequency in the absence of agonist. From a comparison of the -AChR with complete receptors containing either the or -subunit, we conclude that the and -subunits influence most channel properties, including agonist binding, and are especially important for stabilizing the closed state of the unliganded receptor channel. The -AChR can form when a complete set of four subunit-specific mRNAs is injected. The ease with which it is assembled raises the possibility that the - AChR contributes to some of the variations in receptor properties that occur during development.  相似文献   

5.
We studied the content and expression of mRNA for estrogen receptors receptors- and - in breast tumors before and after 3-month neoadjuvant hormone therapy with antiestrogen tamoxifen and/or aromatase inhibitors. Expression of estrogen receptors- and - was most often detected in ER+PR+ tumors and most significantly decreased in these neoplasms after exemestane therapy. Immunocytochemical and radioligand assays showed that tamoxifen and anastrozole have little effect on the number of estrogen receptors- The number of progesterone receptors in tumors decreased by the end of anastrozole therapy. Estrogen receptors- were immunocytochemically revealed in 50% primary breast tumors. Anastrozole slightly decreased, while tamoxifen increased the incidence of these receptors. Interruption of signaling through estrogen receptors and suppression of estrogen biosynthesis had different effects on the receptor status of neoplasms and distribution of estrogen receptors- and -.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 559–562, November, 2004  相似文献   

6.
Fecal isolates of Escherichia coli which were collected from human patients in different parts of Germany between 1985 and 1992 were examined for production of verotoxins (VT). Among 2165 isolates 54 (2.5%) verotoxigenic E. coli (VTEC) were found. The 54 VTEC belonged to 13 different serotypes, 46 (85.2%) of these were enterohemorrhagic E. coli (EHEC) types as O157H7, O157H-, O145H-, O111[H8] and O26[H11]. Of the 54 VTEC 50 (92.6%) hybridized with one or both of the DNA probes specific for VT1 and VT2. The 4 VTEC strains which were negative for VT1 and VT2 differed from all other VTEC by many phenotypical trains such as serotype, production of -hemolysin and absence of EHEC-plasmid and attaching and effacing (eae)-specific DNA sequences. In contrast, VTEC which were positive for VT1, VT2 or both were frequently positive for eae sequences (92.0%), EHEC-plasmids (90.0%) and for production of enterohemolysin (88.0%). With enterohemolysin as an epidemiological marker more VTEC strains (81.5%) could be identified than with others such as the absence of -glucuronidase activity (61.1 %) or non-fermentation of sorbitol (48.1%). Case reports were available for 42 of the 54 VTEC strains. The clinical presentation of 42 cases with VTEC ranged from uncomplicated diarrhea to severe diseases as hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS). However, bloody diarrhea, HC and HUS were more associated with the O157 group than with other VTEC groups.  相似文献   

7.
Prior heavy-intensity exercise facilitates the pulmonary oxygen uptake (O2) response during subsequent exercise, such that its kinetics returns towards first-order. To better understand this priming phenomenon, we investigated the effect of priming exercise, over a range of intensities, on the O2 response to heavy-intensity cycle ergometry at a work rate of 50% [halfway between lactate threshold (LT) and O2max]. Eight subjects performed two consecutive 6-min bouts separated by 6 min at 20 W. The first bout was each of: no warm-up control (CON), sub-lactate threshold (LT) at 80% of LT, and three supra-LT conditions (20%, 40%, and 60%). The O2 response during the subsequent bout was evaluated using the effective time constant (), and the O2 difference between minutes 3 and 6 (O2(6–3)). The goodness-of-fit, indicative of first-order kinetics, was determined by the residual profile, and the mean square of errors (MSEr). The heart rate and blood lactate concentration ([La]r) just prior to the second bout were also measured. Compared with CON, and O2(6–3) were significantly reduced following all supra-LT priming bouts, while the goodness-of-fit was significantly improved following 40% exercise. O2(6–3) and [La]r were negatively correlated (P<0.05), unlike HR. In conclusion, prior exercise just above, but not below, LT facilitated the O2 response in a threshold-like manner. Supra-LT priming exercise influenced the O2 response allowing it to return to within as little as 12% from first-order (compared to ~50% in CON). The associated increases in circulating lactate and/or related factors seem to be centrally involved in this phenomenon.  相似文献   

8.
Summary Several double-stranded complexes of copolyribonucleotide of inosinic and guanylic acids with polyribocytidylic acid (poly IGC) were found to possess interferon inducing activity stronger than poly ICin vivo, Their activity increased in parallel with increase in the ratio of guanine base to hypoxanthine base in these copolymers as far as double-strand formation was observed with polyribocytidylic acid. Many other combinations of copolyribonucleotide with homopolyribonucleotide were also investigated, and several of them were found to induce interferon. However, the interferon inducing effects of these combinations including complementary base-pairings of hypoxanthine and cytosine increased in parallel with the length of the base-pairings, thus approaching to that of poly IC. It is, therefore, supposed that the activity of poly IG C is somewhat different from poly IC and that those of other combinations owe to the essential structure of poly IC. Furthermore, kinetics of interferon induction, cross tolerance to reinduction, and antiviral effectsin vivo of poly IGC and poly IC were studied.  相似文献   

9.
Summary Neurofibrils were compared in warm (30 °C) acclimated (H) and cold (6 °C) acclimated (C) lizards (Sceloporus) by reduced silver staining. In H and C sections stained simultaneously by Bodian's protargol method, the neurofibrils: are generally equivalent along the lengths of dendrites and axons, are thicker and fewer in large multipolar neurones in C sections, and are many times more numerous as rings (boutons) in synaptic regions of the C sections. The morphology of the rings in C and H sections is similar, and no indication of abnormal rings or argyrophilic granules indicating degeneration is present. Comparison of rings per unit volume (104m3) show characteristic ratios for each synaptic region varying from 35:12 (CH) in the large-celled layer of the hippocampus to 602 in the cerebellar molecular layer. Counts of over 60 rings in 104m3 are routinely present in most major synaptic regions in C sections whereas the H sections do not show ring counts above 20/104m3 in any region. It is concluded that the experimentally induced alterations in number of neurofibrillar rings represents a specific response of some neuronal elements to thermal stress.  相似文献   

10.
Mechanisms underlying facilitation by dopamine of extracellular adenosine 5-triphosphate (ATP)-activated current were investigated in rat pheochromocytoma PC12 cells using the whole-cell voltage-clamp techniques. Dopamine (10 and 100 M) augmented the peak amplitude of an inward current elicited by ATP (3–100 M). The activation time course of the ATP-evoked current was accelerated by dopamine; the presence of 10 M dopamine shifted the dependence of activation rate constants on the concentration of ATP toward a lower concentration range two fold. Dopamine also accelerated the inactivation and the deactivation, which was determined from the current decay upon washout of ATP. Intracellular mediators responsible for the dopamine-induced facilitation was estimated by loading various compounds in patch pipettes. Facilitation was not observed when K-252a (1 M), a protein kinase inhibitor, was included in the intracellular solution. In addition, facilitation was also attenuated by intracellular adenosine 5-O-(thiotriphosphate)tetralithium salt (ATPS (1 mM) or --methylene ATP (1 mM). Inclusion of adenosine 3, 5-cyclic monophosphate sodium salt (cAMP, 100 M), guanosine 3,5-cyclic monophosphate sodium salt (cGMP, 100 M), 12-O-tetradecanoylphorbol-13-acetate (TPA, 1 M) or phorbol-12,13-dibutylate (1 M) in the intracellular solution did not affect the facilitation. Guanonsine 5-O-(thiotriphosphate)tetralithium salt (GTPS, 500 M) or guanosine 5-O(2-thiodiphosphate)-trilithium salt (GDPS, 500 M) did not modify the facilitation either. The results suggest that dopamine augments the ATP-activated inward current by facilitating association of ATP to its binding site, and that the augmentation may be mediated through some protein kinase which is different from cyclic-nucleotide-dependent protein kinases or protein kinase C.  相似文献   

11.
Shear stress modulates endothelial cell (EC) remodeling via realignment and elongation. We provide the first evidence that the upstroke slopes of pulsatile flow, defined as shear stress slew rates (positive / affect significantly the rates at which ECs remodel. We designed a novel flow system to isolate various shear stress slew rates by precisely controlling the frequency, amplitude, and time-averaged shear stress ave of pulsatile flow. Bovine aortic endothelial cell (BAEC) monolayers were exposed to three conditions: (1) pulsatile flow (1 Hz) at high slew rate (293 dyn/cm2 s), (2) pulsatile flow (1 Hz) at low slew rate (71 dyn/cm2 s), and (3) steady laminar flow at /t=0. All of the three conditions were operated at ave=50{dyn/cm}2. BAEC elongation and alignment were measured over 17 h. We were able to demonstrate the effects of shear stress slew rates /t on EC remodeling at a fixed spatial shear stress gradient (/x). We found that pulsatile flow significantly increased the rates at which EC elongated and realigned, compared to steady flow at /t=0. Furthermore, EC remodeling was faster in response to high than to low slew rates at a given tau ave © 2002 Biomedical Engineering Society. PAC2002: 8719Tt, 8719Rr  相似文献   

12.
Endothelial cells play an important role in adhesive interactions between circulating cells and extracellular matrix proteins. In vitro studies have shown that many of these processes are mediated by a superfamily of heterodimeric transmembrane glycoproteins called integrins. The distribution patterns of 1, 3 and 4 integrin subunits in endothelial cells (EC) in situ were examined immunohistochemically on serial forzen sections of a wide range of non-neoplastic tissues and of vascular tumours, both benign and malignant. Expression of the 1 subunit was a constitutive feature of EC. Among the 1-associated subunits, 5 and 6 were broadly distributed in EC, irrespective of vessel size and microenvironment. The 3 subunit displayed intermediate levels of expression with a slight preference for small vessel EC. Presence of 1 was confined to EC of capillaries and venules/small veins. Expression of 2 in EC was inconsistent. With rare exceptions, the 4 chain was absent in EC. The 3 and v subunits were expressed in most EC, though not always concomitantly. In contrast to the 1 chain, however, these integrin subunits were absent in EC of glomerular capillaries and were expressed variably in sinusoidal EC. The 4 chain was evenly present in the great majority of EC, except for those of large vessels. In vascular tumours, the patterns of 1 and 1 to 6 subunit expression generally corresponded to those found in their non-neoplastic counterparts. Expression of 3, v and 4 chains, however, decreased in neoplasia, especially in angiosarcomas. These data show that EC dispose of broad and at the same time differential repertoires of integrin subunits that presumably reflect vessel-type associated functional differences among these cells. In vascular tumours, the orthologous distribution patterns of 1 and 1 to 6 chains are conserved in most instances while the amounts of 3, v and 4 subunits expressed in EC tend to decrease in the course of malignant transformation.Dedicated to Prof. Dr. med. Dres. h.c. Wilhelm Doerr on the occasion of his 80th birthday  相似文献   

13.
Zusammenfassung Es wurde eine 40jährige Frau mit sog. Stiff-man-Syndrom untersucht. In Narkose und Lumbalanaesthesie verschwand die abnorme Muskelverspannung. Ebenso normalisierte sich unter Differentialblockade des N. femoralis durch Procainumspritzung der Tonus im Quadriceps vorübergehend ohne Lähmungserscheinungen. Daraus kann gefolgert werden, daß die-Motoneurone wesentlich am Zustandekommen der Muskelverspannung beteiligt sind. Histologisch ergab sich kein krankhafter Muskelbefund. Elektromyographisch bestand eine langanhaltende Aktivität in den befallenen Muskeln, die sich von Willkürentladungen nicht unterscheiden ließ. Bei passiven Bewegungen wurde eine ungewöhnliche Entdehnungsaktivität registriert. Unter Willkürinnervation bestand ein normal dichtes Muster. Bei Entspannung nach aktiver Innervation trat nach kurzer Entlastungsreaktion Überdauerungsaktivität auf. Einzelpotentiale, Nervenleitgeschwindigkeit, mechanisch und elektrisch (H-Reflex) ausgelöste Muskeleigenreflexe waren normal, die silent period nicht verändert. Der H-Reflex zeigte unter subparalytischer Dosis von Succinylcholin einen Abfall wie beim Gesunden.Unter Behandlung mit Diazepam und einem Amino-Buttersäurederivat verschwand die abnorme Muskelspannung fast vollständig. Es wird die Annahme vertreten, daß es sich bei dieser Form des Stiff-man-Syndroms, die dem Syndrom vonMoersch undWoltman entspricht, um ein Parabiosephänomen der-Motoneurone handelt (Spindelmyotonie). Analog dazu liegt beim Isaacs-Syndrom eine Überaktivität der peripheren -Motoneurone vor (Neuromyotonie). Bei anderen in der Literatur beschriebenen Formen des Stiff-man-Syndroms handelt es sich offensichtlich um primäre Muskel- oder Bindegewebserkrankungen.
Summary A 40 years old woman suffering from the so-called stiff-man syndrome is described. The abnormal muscle-tonus disappeared in narcosis and in lumbar anaesthesia. When procaine was infiltrated close to the nervus femoralis, the tonus in the quadriceps muscle was normalised temporarily without the muscle being paralysed. Consequently the-motoneurones may be considered as an essential factor in bringing about the pathological muscle stiffening. Histologycally there was no evidence of muscle disease. The EMG showed a long-lasting activity in the stiffened muscles which did not differ from a normal pattern. During passive shortening of the muscle abnormal activity was registered. An interference pattern was seen with maximum voluntary contraction. Active innervation was followed by anew electrical activity in the relaxing muscle, only interrupted by a short silent interval. Single units, nerve conduction velocity, the potentials of the muscle stretch reflex an the H-reflex were normal. The silent period was not altered. Under subparalytical dosage of succinylcholine the amplitude of the H-reflex showed a decrease in a physiological manner. The muscle stiffness disappeared almost completely when the patient was treated with diazepam (Valium) and a derivate of amino-butyric acid (CIBA 34-647 Ba).There is some reason to believe that this variety of stiff-man syndrome, being identical with the syndrome described byMoersch andWoltman, is caused by the parabiotically diseased-motoneurones (spindlemyotonia). Likewise a hyperactivity of peripheral -motoneurones is known to bring aboutIsaacs syndrome (neuromyotonia). Other varieties of the stiff-man syndrome described by literature are obviously primary diseases of the muscle or connective tissue.


Herrn ProfessorG. Schaltenbrand zum 70. Geburtstag gewidmet.  相似文献   

14.
Summary We compared the serum concentrations of soluble CD8 with the immune activation markers neopterin, interferon-, tumour necrosis factor-, soluble CD4, and with CD34+ and CD38+ T-cell counts in patients with human immunodeficiency virus (HIV) infection. The majority of patients had increased concentrations of soluble CD8, interferon- and neopterin, and various significant correlations existed between them. Our results support the view that enhanced soluble CD8 levels indicate activated CD8+ T cells in patients with HIV infection.Abbreviations sCD8 serum-soluble CD8 - sCD4 serum-soluble CD4 - IFN- interferon- - TNF =tumour necrosis factor- - HIV human immunodeficiency virus - AIDS acquired immunodeficiency virus  相似文献   

15.
Pathogenic mechanisms that underlie feline leukaemia virus subgroup-C (FeLV-C) induced erythroid aplasia are unknown. FeLV-C infection is associated with higher serum levels of interferon- (IFN-) and tumour necrosis factor- (TNF-), which may act synergistically to cause haemopoietic suppression. In the present studies, the synergistic effects of TNF- and IFN- on feline bone marrow progenitors in vitro were evaluated. Bone marrow mononuclear cells from specific-pathogen-free cats were exposed to TNF- (100 and 200 pg/ml) and IFN- (100 or 200 units/ml), alone or in combination, for 2 h before plating for clonal assays of colony forming units. Our results show that TNF- and IFN- in combination caused marked suppression of feline colony forming units-erythroid (CFU-E), burst forming units-erythroid (BFU-E), and colony forming units-fibroblasts (CFU-F), whereas colony forming units-granulocyte/macrophage (CFU-GM) were minimally affected. The same concentrations of TNF- and IFN- alone had minimal effects on CFU-E, BFU-E and CFU-F. These results suggest that TNF- and IFN- may play a significant role in regulating haemopoiesis in cats and may be involved in the pathogenesis of erythroid aplasia in cats infected with feline leukaemia virus.  相似文献   

16.
We have investigated the role of recombinant human interleukin-1 (rIL-1) and recombinant human tumor necrosis factor (rTNF-) on PLA2 activity, protein synthesis and eicosanoid production in bovine pulmonary artery endothelial cells. Cellular PLA2 activity increased 4-fold and production of PGE2 increased 3-fold at 1–2 hrs in the presence of 10 units/ml rIL-1. PLA2 activity increased 3-fold at 30 min and PGE2 production increased 2-fold with 5×10–9 M rTNF-. The data show that endothelial cells respond more rapidly to rIL-1 (2–6 hr) and rTNF- (30 min) than do chondrocytes and synovial cells (6–16 hrs), suggesting endothelial cells may play a primary role in initiating the inflammatory response.  相似文献   

17.
Five clinical strains ofYersinia isolated in Japan and identified as atypical biotype 3 or biotype 3B, serotype O:3, phage type II (3*/O3/II)Yersinia enterocolitica were characterised since the biochemical reactions of these strains indicate they might also belong to the speciesYersinia bercovieri. Biochemical tests, characterisation of the -lactamases and DNA-DNA hybridization studies provided strong evidence indicating that these strains should be classified asYersinia enterocolitica. A simple scheme combining a disc diffusion test and four biochemical tests was devised for identification of these atypical strains.  相似文献   

18.
We have previously observed that following the onset of moderate intensity cycle ergometry, the pulmonary O2 uptake (O2) in trained cyclists often does not increase towards its steady-state value with the typical mono-exponential characteristics; rather, there is a transient overshoot. The purpose of this study was to systematically examine this phenomenon by comparing the O2responses to two moderate-intensity work rates and one high-intensity work rate in trained and untrained subjects. Following a ramp exercise test to the limit of tolerance for the determination of the gas exchange threshold (GET) and O2peak, seven trained cyclists [mean (SD); O2peak 66.6 (2.5) ml·kg–1·min–1] and eight sedentary subjects [O2peak 42.9 (5.1) ml·kg–1·min–1] completed six step transitions from baseline cycling to work rates requiring 60% and 80% GET and three step transitions from baseline cycling to a work rate requiring 50% of the difference between GET and O2peak (50%). O2 was measured breath-by-breath and modelled using standard techniques. The sedentary subjects did not overshoot the steady-state O2 at any intensity. At 60% GET, six of the seven cyclists overshot the steady-state O2 [by an integral volume of 164 (44) ml between ~45 and 125 s]. At 80% GET, four of the seven cyclists overshot the steady-state O2 [by an integral volume of 185 (92) ml between ~55 and 140 s]. None of the cyclists showed an overshoot at 50%. These results indicate that trained cyclists evidence an overshoot in O2 before steady-state is reached in the transition to moderate-intensity exercise. The mechanism(s) responsible for this effect remains to be elucidated, as does whether the overshoot confers any functional or performance benefit to the trained cyclist.  相似文献   

19.
Summary Earlier studies concerning 1 gene regulation by the 4 protein, the major regulatory protein of herpes simplex virus 1 (HSV-1), in stably transformed cell lines, reported conflicting results, i.e., 4 protein positively regulated the 1 gB gene in 4/gB cells, while it negatively regulated the 1 gD gene in 4/BJ cells. Both cell lines were derived from a common parental cell line 4/c 113 that contains 1 copy of the 4 gene, and the only apparent difference between them was the relative copy number of the gB and gD sequences (1 and 30–50, respectively) resident in the cell genome. We investigated this disparity by constructing a cell line (BA 4) that contains one copy each of the 4 and 1 gD sequences, by fusion of 4/c 113 and BJt cells, containing and expressing respectively 1 copy of the 4 and gD genes. BA 4 cells constitutively expressed both the 4, gD genes inherited from the parental cell lines ( 4/c 113 and BJt). In BA 4 cells the 4 protein positively regulates the gD gene as evidenced from (i) higher levels of gD expression than the parental BJt cells lacking the 4 gene, and (ii) significant decrease in gD expression under conditions that render the 4 protein produced in BA 4 cells non-functional. In addition the 2gG gene contained within the DNA fragment encoding the gD gene, is also expressed in BA 4 cells. On the basis of these data, we propose that gene regulation by the 4 protein is affected by the relative copy number of these genes, resident in the cell genome.  相似文献   

20.
Candida albicans (C. albicans) is a major nosocomial pathogen. We examined arachidonic acid (AA) and cytokine production by monocytes stimulated with C. albicans. [14C]-AA labeled monocytes released 8.9 ±2.3% of the incorporated AA following stimulation with live C. albicans (C. albicans: monocyte of 161) (P=0.0002). Prior studies indicate that soluble-mannans and-glucans antagonize mannose and-glucan receptors, respectively. Preincubation of monocytes with-mannan (100g/ml) caused 45.8 ±5.7% inhibition of [14C]-AA release, whereas-glucan (100g/ml) yielded 43.7 ±6.0% inhibition (P<0.05 for each compared to control). Additionally, monocytes stimulated with C. albicans also released interleukin-1 (IL-1), tumor necrosis factor- (TNF), interleukin-6 (IL-6) and interleukin-8 (IL-8). However, a-mannan or-glucan failed to inhibit IL-1 release. These data indicate that C. albicans induces monocytes to release AA and inflammatory cytokines. Furthermore, AA, but not cytokine liberation, is partially mediated by a-mannan and-glucan components of the fungus.  相似文献   

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