Mengovirus-Induced Cytopathic Effect in L-Cells: Protective Effect of Interferon

The effect of interferon on mengovirus-induced cytopathic effect (CPE) in L cells, the cut-off of host-cell protein synthesis, and production of mature virus were found to be dependent on the concentration of interferon. CPE and inhibition of host protein synthesis were not affected until the concentration of interferon was increased 100-fold over that required to reduce viral yields by 90%.     

复方克痛宁临床应用镇痛效果

应用复方克痛宁注射液,治疗各种痛证８２例,显效５０％,有效４３．９％,总有效率９３．９％。其中大多数病例都是经用其它药或疗法无效或效差而用本药获效的。对关节痛、神经血管性头痛等顽固性疼痛显著独特。用药次数最少１次,最多３５例,仅极个别有轻微短暂口干、头晕副作用,各项常规化验检查均无异常,效果显著高于克痛宁或盐酸平痛新单用。临床应用的结果与动物试验观察到的协同增效结果一致。     

具有初始效应的Logistic方程

在植物原生质体培养中,作者发现原生质体（细胞）增长有初始效应,由此导出了具有普适意义的含初始效应的Logistic方程：。此方程可用来描述任何大小的初始种群在初始状态下的增长动态。本文作者还给出了上述方程中各参数的求解方法。     

Zn、Cd及其复合对小麦幼苗吸收Ca,Fe,Mn的影响

研究了溶液培养条件下,Cd,Zn及其复合对小麦幼苗吸收Ca,Fe,Mn的影响,结果表明,小麦幼苗对Zn,Cd的吸收随溶液中Cd^2 ,Zn^2 浓度的升高而增加,Cd,Zn同时存在时与其单独作用时幼苗对它们的吸收不同,Zn影响幼苗对Cd的吸收,Cd对Zn的吸收起抑制作用,Ca,Mn的吸收随溶液中Cd^2 ,Zn2 浓度升高而呈下降趋势,在Cd单独处理组和Zn单独处理组中Fe的吸收随Cd2 ,Zn2 浓度升高而增加,但在Zn Cd处理组中,Fe的吸收则呈下降趋势,其效应试学与作物具体部位有关。     

Effect of prolactin on ovarian steroidogenesis

This review summarizes evidence that prolactin (PRL) is involved directly in the regulation of ovarian steroidogenesis. The scope of this paper will be limited to two areas. The first area involves the regulation of the corpus luteum function and the second the effect of PRL on steroidogenesis during the follicular phase of the oestrous cycle. Cyclic changes of plasma PRL levels and the ovarian receptors which bind PRL have been observed during the oestrous cycle of domestic animals. The luteotropic effect of PRL and its failure is also presented. PRL may exert a physiological effect on follicle steroidogenesis but its effect depends on the level of follicle maturation. The effect of PRL treatment on estrogen production by follicular cells in vivo and in vitro was studied. The results of many papers indicate suppression of estrogen secretion by the direct action of PRL at the ovarian level. However, there is abundant evidence, that PRL is involved directly in regulation of ovarian steroidogenesis, the precise mechanism remains to be discovered.     

Effect of quinolinate on aminotransferases

Quinolinate inhibits several aminotransferases (ornithine, alanine, and aspartate). However, it is considerably more potent as an inhibitor of liver and heart cytoplasmic aspartate aminotransferase. It is a much less potent inhibitor of mitochondrial aspartate aminotransferases. Quinolinate is bound to the active site of cytoplasmic aspartate aminotransferase. It has a much greater affinity for the pyridoximine-P than the pyridoxal-P form of the enzyme. According to kinetic results, the inhibition or dissociation constant of quinolinate is 0.2 and 20 mm, respectively, for the pyridoxamine-P and the pyridoxal-P forms of the enzyme. Since quinolinate is mainly bound to the pyridoxamine-P form: (a) it is a potent competitive inhibitor of α-ketoglutarate but has little effect when α-ketoglutarate is saturating even if the level of aspartate is low; (b) it decreases the effect of α-ketoglutarate on the absorption spectrum of the pyridoxamine-P form; and (c) it enhances the effect of glutamate on the absorption spectrum of the pyridoxal-P form. Quinolinate is also apparently bound to the apoenzyme since it inhibits reconstitution by either pyridoxamine-P or pyridoxal-P. Since quinolinate is a competitive inhibitor of α-ketoglutarate, it is possible that part of the inhibitory effect of quinolinate on hepatic gluconeogenesis could result from quinolinate inhibiting the conversion of aspartate to oxalacetate by the cytoplasmic aspartate aminotransferase. Quinolinate has no effect on either rat or bovine liver glutamate dehydrogenase or on kidney glutamate dehydrogenase.     

Effect of nanoparticles on aquatic organisms

This paper summarizes the data on the effect of engineered nanoparticles on aquatic organisms. The issues of penetration and accumulation of nanoparticles in the body of aquatic organisms and their toxic effect, biotransformation, and migration along food webs are considered. It is demonstrated that the behavior of nanomaterials in the environment and their effect on living organisms have been studied insufficiently and require close attention, because their release into the environment will increase in the very near future.     

Group Size Effect on Cooperation in One-Shot Social Dilemmas II: Curvilinear Effect

In a world in which many pressing global issues require large scale cooperation, understanding the group size effect on cooperative behavior is a topic of central importance. Yet, the nature of this effect remains largely unknown, with lab experiments insisting that it is either positive or negative or null, and field experiments suggesting that it is instead curvilinear. Here we shed light on this apparent contradiction by considering a novel class of public goods games inspired to the realistic scenario in which the natural output limits of the public good imply that the benefit of cooperation increases fast for early contributions and then decelerates. We report on a large lab experiment providing evidence that, in this case, group size has a curvilinear effect on cooperation, according to which intermediate-size groups cooperate more than smaller groups and more than larger groups. In doing so, our findings help fill the gap between lab experiments and field experiments and suggest concrete ways to promote large scale cooperation among people.     

Antistress Effect of Nitric Oxide

Rat strains feature different resistances to stress. The increased production of nitric oxide (NO) in the August strain prevents the appearance of ulcerous lesions of gastric mucosa and behavioral changes induced by restraint stress. Wistar rats feature a lower level of NO production and are more sensitive to restraint stress compared to the August rats according to both the ulcerous gastric lesions and behavioral parameters. The stress-induced release of catecholamines was mimicked by experimental hyperfunction of the dopaminergic (DA) system induced by L-DOPA. The NO synthase inhibitor N-nitro-L-arginine (L-NNA) enhanced the L-DOPA-induced behavioral changes. This effect was more pronounced in the August strain. The administration of the exogenous NO donor, dinitrosyl iron complexes (DNIC), limited the behavioral disturbances induced by L-DOPA in both rat strains. The protective effect of DNIC in conditions of the DA system hyperfunction is similar to the effect of a D₂blocker sulpiride. Thus, NO has a central antistress effect apparently mediated by limiting the release of catecholamines.     

Effect of Naturally Occurring Xanthines on Bacteria: I. Antimicrobial Action and Potentiating Effect on Antibiotic Spectra

The effect of xanthines on various microorganisms was studied. The antibacterial effect was not high; most of the test organisms could easily withstand a concentration of 2,500 μg/ml. Caffeine was more antibacterial than theophylline, and the latter more than theobromine. Caffeine citrate exhibited greater inhibitory effect than did pure caffeine. The effect was both bacteriostatic and bactericidal against susceptible organisms. The susceptibility of organisms to xanthines differed greatly even in related species. The morphology of Aerobacter aerogenes and A. cloacae was affected under the influence of caffeine; filamentation of cells followed sublethal doses. Potentiation was seen with antibiotics and caffeine; resistant strains were killed with a lower dose of drug in the presence of caffeine. This potentiating effect was pronounced with the tetracyclines; with streptomycin, the effect was the contrary.     

Effect of polyvinylpyrrolidone on microbial cells

The oral administration of polyvinylpyrrolidone to rats produces no effect on the intestinal microflora. At the same time, polyvinylpyrrolidone solutions decrease the toxicity of Escherichia coli and Proteus vulgaris, produce a bactericidal and agglutinating effect.     

Polyethylelimine Masks Mitogenic Effect of DNA

Abstract

The effect of polyethylenimine on the mitogenic stimulation of murine splenocytes by DNA and oligonucleotides has been investigated. It was found that polyethylenimine masks the mitogenic stimulation effect of the compounds.     

Effect of antibiotics on Francisella tularensis]

The minimum inhibitory concentrations of rifampicin, doxycycline, sisomicin, ciprofloxacin and phosmidomycin for various strains of Francisella tularensis were 0.5 to 2.0, 0.5 to 2.0, 0.125 to 0.4, 0.625 to 0.125 and 2.0 to 12.5 micrograms/ml, respectively. Ciprofloxacin and sisomicin had a marked bactericidal effect. The bactericidal effect of rifampicin was insignificant. Doxycycline and phomidomycin had practically no such effect. All the antibiotics had a post effect. The level of the post-antibiotic effect was different and depended on the antibiotic concentration.     

Effect of hydrostatic pressure on nucleic acids

In comparison to other biomolecules, the effect of hydrostatic pressure on the conformational stability of DNA and RNA has received scant attention. However, the increasing interest in the hydration of biological molecules has resulted in a concomitant increase in the number of investigations of the effect of pressure upon the structure of nucleic acids. In this review, studies concerning the effect of pressure on DNA and RNA oligomers and polymers are presented. The greatest amount of research has been directed at studying the effect of pressure on the stability of the double helix. In general, under most conditions, the helical form of DNA or RNA is stabilized by pressure. The extent of stabilization is small relative to the effect of pressure on other biomolecular systems such as lipid membranes or protein quaternary structure. The absence of a larger pressure effect arises, in part because the state of ionization does not change as a function of the helical state. Initial experiments have also appeared on the effect of pressure upon helix-formation kinetics, B-Z and A-Z equilibria, and DNA topology. Fourier-transform ir spectroscopy of DNA polymers under high pressure has yielded data that showing that pressure does not induce large-scale structural changes.     

Effect of alkylbenznes on n-alkane utilization

It has been shown that alkylbenzenes which do not support growth of Pseudomonas aeruginosa exert a stimulatory or inhibitory effect on the utilization of n-alkanes by this organism. The effect is a function or the number of methyl substitutions to the benzene ring and the concentration of aromatic hydrocarbon. The alkylbenzenes have been shown to exert the stimulatory and inhibitory effect, on all phases of growth. The data suggests different mechanisms involved in the inhibition by benzene and p-xylene but a similar mechanism by all of the stimulatory compounds. Warburg data demonstrates changes in the rate of oxygen uptake in the presence of trimethylbenzene at different stages of the fermentation. The release of water soluble material in the presence of trimethylbenzene suggests a permeability effect on the cells.     

The Nocebo Effect of Informed Consent

The nocebo effect, the mirror‐phenomenon to the placebo effect, is when the expectation of a negative outcome precipitates the corresponding symptom or leads to its exacerbation. One of the basic ethical duties in health care is to obtain informed consent from patients before treatment; however, the disclosure of information regarding potential complications or side effects that this involves may precipitate a nocebo effect. While dilemmas between the principles of respect for patient autonomy and of nonmaleficence are recognized in medical ethics, there has not yet been an ethical discussion focused on the potential dilemma raised by the nocebo effect of informed consent (NEIC). This dilemma is especially pernicious, since it involves a direct causality of harm by the caregiver that is unparalleled by other potential harmful effects of information disclosure. This paper articulates the dilemma of the NEIC and offers a seminal ethical analysis.     

Effect of oat seed treatment with microelements

Summary A field experiment was carried out to study the effect of treating oats seeds with the microelements boron, cobalt and copper. Treatment with microelements had no marked effect on seed germination. Tillering rate was increased by B- and Co-treatments. Boron and cobalt had positive effect on panicle length, and cobalt positively influenced plant height. The most beneficial effect of microelements was on number and weight of grains in a panicle. Boron and cobalt had increased hectoliter weights. As a result of the effects, Co and Cu produced higher grain yields than the check. The highest yield was obtained with copper treatment.     

Effect of Dexamethasone on Rat Respiratory Pathways

It has been shown that a short-term application (10–15 min) of dexamethasone at a concentration of 1.0 µg/ml decreases the muscular contraction amplitude of the trachea and large bronchi to 76.2 ± 3.5% and increases the dilatational effect of histamine (1.0 µg/ml) to 47.4 ± 8.1% at stimulation of pre- and postganglionic nerve fibers. Atropine eliminates completely the effect of dexamethasone on the respiratory tract preparation at the stimulation of pre- and postganglionic nerve fibers. The ganglioblocker decreases the dilatational effect at a simultaneous application of atropine and dexamethasone from 47.4 ± 8.1 to 67.2 ± 5.3%. It is concluded that the dexamethasone effect is due to its action on tracheobronchial epithelial receptors and that this effect is mediated by intramural ganglionic neurons.     

Effect of oestradiol on catecholamine-stimulated lipolysis

The authors studied the effect of a single in vivo dose of oestradiol (OE) on adrenergic lipolysis in the epididymal adipose tissue of adult and juvenile male rats, and the effect of OE on plasma free fatty acids (FFA), cholesterol and beta-lipoprotein levels at various intervals after its administration. It was found that OE injected 24 h beforehand in vivo (s.c.), in doses of 100 and 200 micrograms X kg-1 body weight, significantly potentiated the lipid-mobilizing action of the catecholamines noradrenaline (NOR) and isoprenaline (ISO) in adult rats (the action of ISO was potentiated more intensively); in addition, the adipose tissue became more sensitive to the action of NOR, but not of ISO. Raising the dose of OE to 400 micrograms X kg-1 did not enhance the potentiation of the lipolytic action of the catecholamines any further; on the contrary, the lipid mobilizing effect of the catecholamines was potentiated less than after half this dose. Following the s.c. injection of an oily OE solution, the lipolytic effect was potentiated after more than 7 h; the potentiation was strongest after 12 h, but only as far as the maximum attainable degree of lipolysis was concerned. Potentiation of adrenergic lipolysis was found only in adult male rats. In male rats weighing 130-150 g the lipolytic effect of catecholamines (in mumol/g adipose tissue) was significantly greater than in adult animals and the pre-administration of OE did not potentiate adrenergic lipolysis any further. Determination of plasma FFA, cholesterol and beta-lipoprotein levels 1, 2, 4 and 6 hours after the s.c. injection of OE showed only nonsignificant changes (an increase in FFA and a decrease in cholesterol). The authors consider it important to distinguish between the effect of OE on catecholamine-stimulated lipolysis in depot adipose tissue and its effect on lipid metabolism. In their opinion, the dose-dependent effect of OE on muscular and metabolic adrenergic reactions could be one of the factors co-reversible for certain side reactions to steroid contraceptives.     

Antimicrobial Effect of Human Serum IgA

Serum IgA, IgG and colostrum secretory IgA prepared from specimens pooled from a large number of human beings were shown to have measurable levels of antibodies against Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, poliovirus, Coxsackie B virus, echovirus and influenza virus. Serum IgA exerted a bacteriostatic effect in vitro on E. coli and P. aeruginosa, which increased in the presence of the iron-binding proteins lactoferrin and transferrin. This bacteriostasis was reduced when the iron-binding proteins were saturated with iron. Similar results were obtained with IgG and secretory IgA. The bacteriostatic effect of serum IgA was also shown in vivo, in the peritoneal cavity of mice. The effect was suppressed by iron. Iron-chelating substances, siderophores, excreted by E. coli diminished the cosoperative bacteriostatic effect of serum IgA and transferrin. Siderophore production by E. coli was inhibited in the presence of serum IgA, but not when serum IgA was deprived of specific antibody by absorption with E. coli. These results indicate that serum IgA has a potent bacteriostatic effect in cooperation with transferrin or lactoferrin because of the inhibitory effect of the specific antibody on siderophore production by E. coli.