showing 36 of ~574560 from 574555 documents
Identification of a plasminogen-binding motif in PAM, a bacterial surface protein.
1995
Surface-associated plasmin(ogen) may contribute to the invasive properties of various cells. Analysis of plasmin(ogen)-binding surface proteins is therefore of interest. The N-terminal variable regions of M-like (ML) proteins from five different group A streptococcal serotypes (33, 41, 52, 53 and 56) exhibiting the plasminogen-binding phenotype were cloned and expressed in Escherichia coli. The recombinant proteins all bound plasminogen with high affinity. The binding involved the kringle domains of plasminogen and was blocked by a lysine analogue, 6-aminohexanoic acid, indicating that lysine residues in the M-like proteins participate in the interaction. Sequence analysis revealed that the…
The glass transition of mixtures of polystyrene with alkyl-terminated oligostyrene — experimental evidence for microphase separation in a polymer ble…
1995
Mixtures of high molecular weight polystyrene (P n = 961.5 ; T g = 373 K) and sec-butyl-terminated oligostyrene (P n = 10.6 ; T g = 302 K) show a dependence of the glass transition on the composition (i.e., number-average molecular weight) which cannot be described by the classic equations of Fox & Flory or Kanig & Ueberreiter. Addition of small amounts of the oligostyrene strongly decreases the glass transition, and above an oligomer content of 40 wt.-% the glass transition remains constant within experimental error. This behavior can be attributed to the unfavorable interactions between the alkyl-terminated oligomer and the high molecular weight PS. As a result the oligomer is a bad solve…
Sequence of the M28 dsRNA: Preprotoxin Is Processed to an α/β Heterodimeric Protein Toxin
1995
The killer and immunity phenotypes of K28 killer strains of Saccharomyces cerevisiae are determined by the 1.75-kb M28 dsRNA virus. In the plus strand, M28p, the K28 preprotoxin gene, comprises bases 13-1047 and is followed, after an additional 85 bases, by a 63-bp poly(A) sequence and a 553-base 3'-sequence. This 3'-sequence contains two potential stem-loop structures predicted to bind the L-A encoded cap-pol protein, initiating encapsidation; high-level expression results in curing of M1 dsRNA. Expression of M28p confers the complete K28 killer and immunity phenotype on a cell lacking M28 dsRNA. K28 toxin is a disulfide-bonded heterodimer of alpha (10.5 kDa) and beta (11 kDa) components w…
Involvement of Free Calcium in Action of Cryptogein, a Proteinaceous Elicitor of Hypersensitive Reaction in Tobacco Cells
1995
Treatment of suspension-cultured tobacco (Nicotiana tabacum var Xanthi) cells with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea, induced a great stimulation of Ca2+ influx within the first minutes. Ca2+ influx is essential for the initiation of cryptogein-induced responses, since ethyleneglycol-bis([beta]-amino-ethyl ether)-N,N[prime]-tetraacetic acid or La3+, which block Ca2+ entrance, suppress cryptogein-induced responses such as extracellular alkalinization, active oxygen species, and phytoalexin production. Moreover, once initiated, these responses require sustained Ca2+ influx within the 1st h. A Ca2+ ionophore (A23187) was able to trigger an extracellular alkaliniz…
In situ study of the phase transition in Bi2Ti4O11
1995
Abstract The paraelectric ⇌ antiferroelectric phase transition of the compound Bi 2 Ti 4 O 11 is studied in situ by electron diffraction and electron microscopy. The transition is reversible and clearly second order. Above T c faint streaking at the superlattice positions persists. In the low-temperature phase, antiphase boundaries with a displacement vector R = 1/2[101] are revealed; they show a finite width, suggesting a gradual displacement of the Bi atoms at the transition. A model for the domain wall configuration is proposed, based on the influence of the lone pairs of Bi 3+ ions at the transition.
Functional, biochemical and morphological studies on human bronchi after cryopreservation
1995
1. Human isolated bronchi have been investigated as fresh tissue or after storage (7 and 30 days) at -196 degrees C in foetal calf serum containing 1.8 M dimethyl sulphoxide. 2. After cryopreservation, the maximal contractile response to acetylcholine (3 mM) was reduced (approximately 25%) but the difference did not reach significance statistically. Maximal responses to other spasmogens tested (histamine, [Nle10]NKA(4-10), bradykinin, leukotriene D4, U46619, and KCl) did not differ between unfrozen and frozen/thawed tissues. The sensitivity of cryopreserved tissues to the constrictor agents tested was similar to that of fresh tissues. 3. The accumulation of inositol phosphates produced by a…
Activating mutations in human c-Ha-ras-1 protooncogene induced by stereoisomeric fjord-region benzo[c]chrysene diol-epoxides.
1995
The mutagenicity of fjord-region benzo[c]chrysene diol-epoxide (BcCDE) stereoisomers((+) anti-BcCDE, (-)anti-BcCDE, (+)syn-BcCDE, and (-)syn-BcCDE) was studied in a forward-mutation system. pEC plasmid containing the human c-Ha-ras-1 proto-oncogene was reacted in vitro with each optically active isomer separately and transfected into NIH/3T3 cells. Morphologically transformed foci were cloned, and DNA obtained from these foci was tested for the presence of Ha-ras-1 sequence by Southern blot analysis. A total of 50 transformed foci (11-14 for each diastereomer) were generated. To determine the nature of mutations responsible for activating the proto-oncogene, regions of the gene likely to co…
Conformational and linear epitopes on virus-like particles of human papillomavirus type 33 identified by monoclonal antibodies to the minor capsid pr…
1995
The organization of epitopes on the minor capsid protein L2 of human papillomavirus (HPV) type 33 has been analysed using three monoclonal antibodies (MAbs) generated against a large fragment of the L2 protein (amino acids 82-259) expressed as a glutathione S-transferase fusion protein. The topology of the L2 epitopes has been investigated with respect to the structure of HPV-33 virus-like particles (VLPs). Two of the MAbs reacted with linear epitopes which were mapped to amino acids 153-160 and 163-170, respectively. These epitopes were accessible in denatured but not in native VLPs consisting of L1 and L2, suggesting an internal location. The third antibody was unable to detect denatured …
Complete characterization of low-noise devices at microwave frequencies: two alternative procedures for HEMTs
1995
Survey of the Working Condition of Used Tractors in Northern Italy
1995
The working condition of 96 used tractors of different ages and sizes was examined in Northern Italy and compared with those of new machines and the standards at present in force. The results show that from the safety point of view, performance levels do not worsen drastically with increase in vehicle age. Rusty roll-over protective structures with cracks and tears are the main danger. Controls which are difficult to operate, seats in very bad condition, high levels of noise and vibrations render the situation critical from the ergonomic point of view.
The analgesic-antiinflammatory extract fromAraujia sericifera lacks ulcerogenic activity on stress-gastric damage model
1995
The present study evaluates the ulcerogenic activity of the hexane extract from dry fruits of Araujia sericifera in an experimental model of cold-restraint stress. Treatment of rats with 200 mg/kg (i.p.) of hexane extract did not affect the gastric lesions induced by cold-restraint stress. However, it was confirmed that a dose of 300 mg/kg (i.p.) of acetylsalicylic acid (ASA) which induced a similar analgesic-antiinflammatory effect, increased significantly the level of gastric damage. Thus, the hexane extract from the fruits of A. sericifera seems to possess analgesic-antiinflammatory properties which are not linked to gastrolesive effects.
Congenital adrenal hypoplasia and hearing loss. A case report
1995
We report on the diagnostics, the therapeutics and the follow-up (to 3 years and 5 months) of a newborn affected by X-linked congenital adrenal hypoplasia. After the beginning of substitute hormonal therapy, the patient underwent periodical clinical examinations, with particular attention to the growth, and laboratory tests, which monitored the hormonal pattern. This experience points out the diagnostic role of low maternal levels of urinary estriol during pregnancy and the importance of a prolonged follow-up, so as to discover associated pathologies as early as possible. In our case, in fact, the study of auditory brainstem responses enabled us to recognize a mild transmission hearing loss…
Altered Regulation of Insulin-Like Growth Factor Binding Protein-I in Patients With Polycystic Ovary Syndrome
1995
Insulin-like growth factor (IGF-I) action is influenced by circulating as well as tissue levels of its binding proteins. Because serum IGF binding protein-1 (IGFBP-1) levels have been found to be decreased in patients with polycystic ovary syndrome (PCOS), we tested the hypothesis that regulation of IGFBP-1 secretion may be different in patients with PCOS compared with normal women. We studied 15 normal ovulatory women and 15 women with PCOS of similar age (21 ± 1 and 22 ± 1 years, respectively). All subjects were studied after an overnight fast between days 5–8 after spontaneous or progestin-induced menses. Perturbations included the administration of insulin intravenously, maintenance of …
Muscle strength and mobility as predictors of survival in 75-84-year-old people.
1995
The purpose of the study was to examine the association of physical capacity, as determined on the basis of self-report and physical measurements, with survival in three groups of elderly people aged 75, 80 and 75-84 years. The main aspects of physical capacity were mobility, walking speed, hand grip strength and knee extension strength. Although 1142 persons participated in mobility interview, of whom 466 also took part in the walking speed test, and 463 in the strength tests. The follow-up periods ranged from 48 to 58 months. Risk of death was significantly related to difficulties in indoor mobility among the 75-84-year-olds (odds ratio = 1.99, 95% confidence interval = 1.27-3.13) and 75-…
Oligosaccharide recognition by selectins: Synthesis and biological activity of multivalent sialyl lewis-X ligands
1995
Abstract Trivalent sialyl Lewis-X ligands 6–8 anchored onto flexible templates have been synthesized and evaluated as inhibitors of E-selectin and P-selectin mediated cell adhesion in cell culture assays and in vivo. Biological activities in vitro correlated with spacer length and lead to ligands with 3-fold (E-selectin) and 5-fold (P-selectin) improved receptor binding avidity per single tetrasaccharide moiety.
Randomised double-blind clinical trial of intermediate- versus high-dose chloral hydrate for neuroimaging of children.
1995
Orally administered chloral hydrate is the most widely used sedative in children undergoing MRI. We compared intermediate- and high-dose oral chloral hydrate in 97 consecutive children undergoing MRI in a prospective, controlled, double-blind, randomised clinical trial. There were 50 girls and 47 boys, mean weight (+/- SD) 14.7 +/- 6.4 kg, and mean age 38 +/- 31. The children were randomly allocated to receive chloral hydrate syrup either 70 mg/kg (group A, n = 50) or 100 mg/kg (group B, n = 47). These two groups were not significantly different in sex, weight, age, diagnosis or ambulatory medication. The mean initial dose (+/- SEM) was 64 +/- 2 mg/kg for group A and 93 +/- 2 mg/kg for grou…
Natural products and enzymes from plant cell cultures
1995
Plants represent an unlimited source of natural products. Many of the recently detected phytochemicals exhibit remarkable bioactivities, ranging from anticancer activity, phosphodiesterase inhibition to cytotoxicity against HIV-infected cells. Cultivated plant cells produce at their unorganized, dedifferentiated stage secondary metabolites, but in very different amounts in so far as new compounds are concerned. In fact, more than 140 novel natural products are presently known from plant cell cultures, which also include new metabolites formed by biotransformation. The biotransformation capacity of suspended cells is described and recent high yielding transformations, like the formation of a…
A comparison of direct and indirect methods for measuring leaf and surface areas of individual bushes
1995
Indirect estimates of leaf area from measurements with three commercially available instruments (DEMON, LAI-2000 and Sunfleck Ceptometer) were compared with directly measured areas of individual Retama sphaerocarpa bushes. The three indirect methods gave good estimates of the total surface area of individual bushes. For the DEMON, the method of log-linear averaging of transmitted radiation gave estimates closer to directly measured surface area than the method of averaging transmission linearly. For the LAI-2000, estimated surface area index multiplied by canopy projected area gave the best agreement with directly measured values. For measurements with the Sunfleck Ceptometer, values of sur…
Pre- and postjunctional effects of diadenosine polyphosphates in the guinea-pig vas deferens.
1995
Abstract The pre- and postjunctional activities of a number of diadenosine polyphosphates were examined in the guinea-pig isolated vas deferens at the level of the membrane-potential, using a modified sucrose-gap technique. P1,P3-Di(adenosine 5′)triphosphate (Ap3A), P1,P4-di(adenosine 5′)tetraphosphate (Ap4A) and P1,P5-di(adenosine 5′)pentaphosphate (Ap5 A) all caused concentration-dependent depolarization of the smooth muscle membrane. The potency order was: Ap5A > Ap4A. Ap3A. P1, P2-Di(adenosine 5′)pyrophosphate (Ap2A) did not evoke depolarization even at the highest concentration tested (1 mM). All the dinucleotides caused a reduction in the amplitude of evoked excitatory junction…
Ultrasound assisted reductive cleavage of sesquiterpene γ-enonelactones
1995
Abstract Ultrasound enhances the rate of reductive cleavage of the C 6 -oxygen bond of several cis - and trans - sesquiterpene γ-enonelactones. Interestingly ultrasound overrides the stereoelectronic requirements for the reductive cleavage of the most usually occurring sesquiterpene trans -lactones.
Polyamines and ripening of photoreceptor outer segments in chicken embryos.
1995
Abstract Polyamines and their related monoacetyl derivatives were studied in rod outer segment (ROS) and cone outer segment (COS) of photoreceptor cells from chick embryo retina during eye development (7th–18th days). Putrescine was found to be necessary, in the second phase of retinogenesis, to sustain both ROS and COS differentiation and, after acetylation, γ-aminobutyric acid synthesis. On the other hand, spermidine and even more spermine intervene in the third phase of development when photoreceptors mature. Moreover, the presence of N1-acetylspermidine already at the 7th day indicates that in the outer segment of photoreceptor cells too, as in the whole retina, putrescine synthesis com…
Phenytoin-induced glutathione depletion in rat peripheral nerve
1995
Abstract Administration of high doses (150–250 mg/kg body weight) of phenytoin (DPH) promote a 40% decrease in glutathione (GSH) content of rat sciatic nerve. This DPH-induced GSH depletion is accompanied with an electrophysiological impairment of peripheral neuromuscular function. H7 (20 mg/kg body weight IP, 30 min prior to DPH), a protein kinase C inhibitor, was able to prevent the DPH-induced GSH depletion only at the lower DPH dose used. This same inhibitor completely prevented the electrophysiological impairment at the lower DPH dose, and only partially at the higher DPH dose used. These results confirm the hypothesis of a DPH-dependent activation of PKC (that might be triggered by, o…
Total cross section measurement for the three double pion photoproduction channels on the proton
1995
Abstract The total cross sections for the three γp → Nππ reactions have been measured for photon energies from 400 to 800 MeV. The γ p → p π 0 π 0 and γ p → n π + π 0 cross sections have never been measured before while the γ p → p π + π − results are much improved compared to earlier data. These measurements were performed with the large acceptance hadronic detector DAPHNE, at the tagged photon beam facility of the MAMI microtron in Mainz.
Standardisierte pathoanatomische Befunddokumentation auf den ADT-Tumorb�gen f�r Malignome des Mundes, der Kiefer und des Gesichts (Version III)
1995
The documentation form for pathohistologic findings (version III) for tumors of the maxillofacial region is presented. It is part of the site-specific documentation of the German Association of Tumor Centers (ADT). Its handling is explained by instructions which are based on the ICD-O classification and the TNM system. The prognostic relevance of the standardized documentation has already been proven by various histomorphologic investigations concerning oral and oropharyngeal cancer. By means of a multicentric observational study the German Austrian Swiss co-operative group DOSAK will develop a new prognostic model for oral and oropharyngeal cancer.
Electrical conductivity and permittivity of water-AOT-n-heptane microemulsions
1995
Measurements of the electrical conductivity and of the complex permittivity of water-sodium bis(2-ethylhexyl) sulfosuccinate (AOT)-n-heptane microemulsions are reported. The experimental results are rationalized in terms of a hopping mechanism of AOT anions within clusters of reversed micelles. The dependence of the hopping rate and of the cluster dimensions upon the ratio [water]/[AOT] and temperature is discussed.
Facility for thermal helium desorption (THDS) measurements
1995
Abstract We describe a thermal helium desorption spectrometer, built at the Department of Physics, University of Jyvaskyla, which will be used in investigations of crystal defects generated by keV range heavy ion bombardment. The helium desorption method and its requirements are reviewed briefly. The structure of the facility itself is presented in detail. The efficiency and the operation of the apparatus is discussed.
Effects of cilazapril on renal haemodynamics and function in hypertensive patients: a randomised controlled study versus hydrochlorothiazide.
1995
In this study the efficacy and safety of short-term cilazapril administration on renal haemodynamics were evaluated in mild to moderate hypertensive subjects. Our final goal was to evaluate whether the reduction in blood pressure achieved by treatment was associated with maintained renal function. After a run-in period with placebo, 40 hypertensive subjects without renal or cardiac diseases were randomly allocated to a double-blind 4 week controlled trial with cilazapril 5 mg once a day (20 patients) or hydrochlorothiazide 25 mg once a day (20 patients). Renal haemodynamics measurements included effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) by radionuclide study us…
La valorisation des investissements éducatifs par le marché : évidence empirique dans le contexte de l'Espagne
1995
International audience
Clinical predictors of unstable coronary lesion morphology.
1995
We evaluated prospectively clinical and angiographic data in 400 patients, 200 with unstable and 200 with stable angina in order to determine which clinical markers could reliably predict unstable coronary artery lesions. Comparison of the angiogram of 200 patients with unstable and 200 with stable angina revealed a high-grade lesion (42% vs 23%, P < 0.0001), complex lesion morphology (49% vs 20%, P < 0.0001) and thrombus-containing lesions (7% vs 1%, P = 0.006) as typical findings in patients with unstable angina. A high-grade lesion and/or complex lesion (including thrombotic lesions but excluding total occlusion) was found in 61% of unstable and 34% of stable patients (P < 0.0001). Clini…
‘Zeitgeist’and minority influence—where is the causality: A comment on Clark (1990)
1995
Does the mood of the time (Zeitgeist) facilitate the influence minorities are able to exercise, or is it itself a direct product of minority influence ? It is argued, from a social psychological definition of the minority-majority relation, that the former interpretation fails to explain many of the observed effects and in particular the conversion effect. A model is offered that is consistent with the second interpretation.
Purification and characterization of the catabolic ?-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris
1995
The α-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris was purified to homogeneity in SDS-PAGE. The enzyme is a trimer of 3×55,000 Da. It was unstable but could be preserved by addition of pyruvate and thiamine pyrophosphate in the buffer. The enzyme exhibits Michaelis-Menten kinetics, and Km for pyruvate is 10 mM. Three intermediates in glucose metabolism (ATP, 3-phosphoglycerate, and phosphoenolpyruvate) exhibit a noncompetitive inhibition towards the enzyme. This enzyme does not require any divalent metal ion for activity. The α-acetolactate synthase from Leuconostoc mesenteroides subsp. cremoris is not inhibited by the branched-chain amino acids (valine, leucine, and…
Phenoloxidase characterization in vacuolar hemocytes from the solitary ascidian Styela plicata
1995
Phenoloxidase (PO) activity was shown in lysates of Styela plicata hemocytes assayed spectrophotometrically by means of L-Dopa oxidation without divalent cations. Trypsin and chymotrypsin pretreatment and preincubation with microbial lipopolysaccharides significantly activated PO, whereas laminarin or zymosan were ineffective. Soybean trypsin inhibitor, tropolone, and phenylthiourea, but not benzamidine, were inhibitors. Finally, hemocytes were separated by a discontinuous Percoll density gradient to determine which cells were active. PO activity was demonstrated, by both biochemical and cytochemical assays, in the separated fraction enriched mainly with the globular granulocytes called mor…
Antibiotic in vivo/in vitro release, histocompatibility and biodegradation of gentamicin implants based on lactic acid polymers and copolymers
1995
Abstract Biodegradable implants containing 10 mg of gentamicin each were prepared by compressing the polymer-drug mixture. The liberation of gentamicin from the implants and the biodegradation of the implants were investigated by following in vitro and in vivo experiments. Implants based on pure poly( l -lactic acid) (L-PLA) released the incorporated antibiotic throughout 30 days with a decreasing delivery rate. During the first 24 h L-PLA implants released a total amount of 3600 μg gentamicin. Within 14 days the release rate had decreased to about 12 μg/day. The release profile of implants based on dl -lactic acid-glycolic acid copolymer (RG 502) was completely different. About 1900 μg wer…
Anxiety and athletic performance of finnish athletes: Application of the zone of optimal functioning model
1995
Abstract The aim of this study was to test five hypotheses based on Hanin's [in Spielberger, C. D. & Diaz-Guerrero, R. (Eds), Cross-cultural anxiety (Vol. 2, pp. 45–64), 1986] Individual Zones of Optimal Functioning (IZOF) model. Eighty Finnish athletes filled out the State Anxiety Inventory two weeks, one week and one hour before the start of a competition. The predicted anxiety level measured two weeks and one week before the competition correlated significantly with the state anxiety level measured one hour before the start. Comparison of athletes preparing for a very important competition showed that those who were inside their optimal individual zone performed significantly better than…
Optimality conditions for shakedown design of trusses
1995
This paper deals with optimal shakedown design of truss structures constituted by elastic perfectly plastic material. The design problem is formulated by means of a statical approach on the grounds of the shakedown lower bound theorem, and by means of a kinematical approach on the grounds of the shakedown upper bound theorem. In both cases two different types of design problem are formulated: one searches for the minimum volume design whose shakedown limit load is assigned; the other searches for the maximum shakedown limit load design whose volume is assigned. The Kuhn-Tucker equations of the four problems here above mentioned are found by utilizing a variational approach; these equations …
The three-spectrometer setup for (e,e'x) coincidence experiments at the Mainz microtron MAMI
1995
A setup of three high-resolution magnetic spectrometers has been built up as the central facility for the precise determination of electron scattering cross sections in coincidence with hadrons. The operational experiencies with two of the spectrometers, A and B, demonstrate that both spectrometers exceed the specifications. With A and B, a series of ( e, e′x ) coincidence experiments were successfully performed. The third spectrometer, C, will be ready for operation in late autumn 1994.