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排序方式: 共有1420条查询结果,搜索用时 15 毫秒
1.
Neonatal treatments can disrupt prepulse inhibition (PPI) of startle response later in life. Alpha2A-adrenergic receptors (alpha2A-ARs) regulate the release of brain neurotransmitters that may influence PPI. The authors examined the effects of short-term reduction in the neonatal brainstem alpha2A-ARs on subsequent development of this receptor system and acoustic startle reflex in rats. Administration of antisense oligodeoxynucleotide complementary to the alpha2A-ARs on Days 2-4 of life reduced receptor expression in the brainstem by Day 5. The treatment increased alpha2-AR numbers in the cortex, hippocampus, and amygdala at 40 days of age, and in cortex and hypothalamus at 90 days of age. Transient increases in hippocampal and amygdalar alpha2-ARs were accompanied by attenuation of acoustic startle response and impairment of PPI. 相似文献
2.
Improved replication of influenza viruses in embryonated chicken eggs (CE) permits increased vaccine production and availability. We investigated the growth properties of influenza B viruses in relation to specific mutations occurring after serial passage in CE. In serial passage experiments yielding high growth variants of B/Victoria/504/2000, mutations predicted to alter amino acid (AA) composition occurred only near the receptor-binding pocket of the hemagglutinins (HA) and in no other genes. Two B/Victoria/504/2000 high growth variants had the same AA substitutions in HA (R162M and D196Y), but the higher yield variant had a third substitution (G141E), which also altered antigenic characteristics. In a serial passage experiment yielding a high growth variant of B/Hong Kong/330/2001, mutations predicted to alter AA composition occurred only in PB2 and NP in domains predicted to relate to RNP formation and function. Our results indicate that adaptation of influenza B viruses to high-yield replication by serial passage in CE requires few mutations either in internal or external genes. Specific modifications of genes or a combination of genes could be used to optimize or create influenza B viruses for specific growth substrates. 相似文献
3.
Laputková G Legin M Sabo J 《Acta medica (Hradec Králové) / Universitas Carolina, Facultas Medica Hradec Králové》2004,47(4):323-326
The influence of D-glucose on a lipid solid support system with the aid of impedance spectrocopy as a preliminary attempt for the biosensing of medical relevant molecules was studied. In spite of some shortcomings, s-BLM's proved to be an appropriate model for the study of lipid membrane-D-glucose interactions. The shortcomings were the roughness of the metal support, and the lack of homogeneity in the monolayer or multilayer lipid structures. 相似文献
4.
Stress-induced analgesia: adaptive pain suppression 总被引:7,自引:0,他引:7
In this paper we have examined the phenomenon of stress-induced analgesia. We have described the procedures used to measure analgesia and have suggested that the tests can be designed not only to indicate changes in pain threshold but also to allow for the determination of the capacity to execute adaptive behavior. Aside from enabling the analysis of responses, tests that induce reflexive as well as nonreflexive behavior may have the capacity to separate the more complex aspects of pain such as the possible presence of two components of pain, sensory/discriminative and motivational/affective. These components may be of fundamental importance for any attempt to understand the biological significance of SIA. Our examination of the neurotransmitter and neuropeptide systems has revealed that they are affected by the same manipulations that induce SIA. These amines and perhaps peptides play an integral role in learning, motivation, and performance. We conclude that the functional advantage of a reduction of pain during stressful situations is significant because it allows the animal to react in threatening and perhaps critical situations as if there were no pain. Once the pain system is inhibited, other systems modulate and mediate adaptive responses that expedite the survival of the animal. 相似文献
5.
Galina Sanaksenaho Annika Mutanen Nimish Godbole Maria Hukkinen Laura Merras-Salmio Reetta Kivisaari Antti Kyrönlahti Marjut Pihlajoki Jouko Lohi Markku Heikinheimo Mikko P Pakarinen 《Journal of pediatric surgery》2021,56(5):966-974
BackgroundIntestinal adaptation has been extensively studied experimentally, but very limited data is available on human subjects. In this study we assessed intestinal adaption in humans with short bowel syndrome (SBS).MethodsWe comparatively evaluated mucosal hyperplasia, inflammation, barrier function and nutrient transport using histology, immunohistochemistry and qPCR for selected 52 key genes in duodenal biopsies obtained from children with SBS after weaning off parenteral nutrition (n = 33), and matched controls without intestinal pathology (n = 12). Small bowel dilatation was assessed from contrast small bowel series.ResultsDuodenal mucosa of SBS children showed increased histologic inflammation of lamina propria (p = 0.033) and mucosal mRNA expression of tumor necrosis factor (p = 0.027), transforming growth factor (TGF)-β2 (p = 0.006) and caveolin-1 (CAV1; p = 0.001). Villus height, crypt depth, enterocyte proliferation, apoptosis and expression of proliferation and nutrient transport genes remained unchanged. Pathologic small bowel dilatation reduced crypt depth (p = 0.045) and downregulated mRNA expression of interleukin (IL)-6 by three-fold (p = 0.008), while correlating negatively with IL6 (r = -0.609, p = 0.004). Loss of ileocecal valve (ICV) upregulated mRNA expression of toll-like receptor 4 (TLR4), TGF-β1, CAV1, several apoptosis regulating genes, and mRNA expression of zonulin (p < 0.05 for all).ConclusionsDespite successful adaptation to enteral autonomy, duodenal mucosa of SBS children displayed histologic and molecular signs of abnormal inflammation and regulation of epithelial permeability, whereas no structural or molecular signs of adaptive hyperplasia or enhanced nutrient transport were observed. Excessive dilatation of the remaining small bowel paralleled impaired duodenal crypt homeostasis, while absence of ICV modified regulation of mucosal inflammation, regeneration and permeability.Level of evidenceII 相似文献
6.
Maria Neufeld Jürgen Rehm Anna Bunova Artyom Gil Boris Gornyi Pol Rovira Jakob Manthey Elena Yurasova Svetlana Dolgova Bulat Idrisov Marina Moskvicheva Galina Nabiullina Olga Shegaym Irina Zhidkova Zukhra Ziganshina Carina Ferreira-Borges the / RUS-AUDIT Collaborators the RUS-AUDIT Project Advisory Board 《Bulletin of the World Health Organization》2021,99(7):496
ObjectiveTo validate a Russian-language version of the World Health Organization’s Alcohol Use Disorders Identification Test (AUDIT).MethodsWe invited 2173 patients from 21 rural and urban primary health-care centres in nine Russian regions to participate in the study (143 declined and eight were excluded). In a standardized interview, patients who had consumed alcohol in the past 12 months provided information on their sociodemographic characteristics and completed the Russian AUDIT, the Kessler Psychological Distress Scale and the Composite International Diagnostic Interview to identify problem drinking and alcohol use disorders. We assessed the feasibility of administering the test, its internal consistency and its ability to predict hazardous drinking and alcohol use disorders in primary health care in the Russian Federation.FindingsOf the 2022 patients included in the study, 1497 were current drinkers with Russian AUDIT scores. The test was internally consistent with good psychometric properties (Cronbach’s α : 0.842) and accurately predicted alcohol use disorders and other outcomes (area under the curve > 75%). A three-item short form of the test correlated well with the full instrument and had similar predictive power (area under the curve > 80%). We determined sex-specific thresholds for all outcomes, as non-specific thresholds resulted in few women being identified.ConclusionWith the validated Russian AUDIT, there is no longer a barrier to introducing screening and brief interventions into primary health care in the Russian Federation to supplement successful alcohol control policies. 相似文献
7.
A trace element preparation (Béres Drops Plus, BDP) produced immunomodulatory effects in previous in vitro and in vivo experiments.
Here, C57B1/6 inbred mice were transplanted with either Lewis lung tumor or with B16 melanoma. BDP was given intraperitoneally
a. before transplantation; b. after transplantation or c. after the removal of the primary tumor. As a result, BDP pretreatment
could slow down the tumor progression by decreasing the number and the volume of metastases as well as the proportion of mice
with metastases without influencing the growth of the primary tumors. Furthermore, BDP treatment improved the immunological
activity of the tumor-bearing host, too. These preliminary data suggest that the parenteral administration of the practically
non-toxic BDP could help to control tumor progression in experimental models. 相似文献
8.
Galina Lurie Gertraud Maskarinec Rudolf Kaaks Frank Z Stanczyk Lo?c Le Marchand 《Cancer epidemiology, biomarkers & prevention》2005,14(6):1521-1527
There is evidence that circulating estrogens are associated with breast cancer risk. In this study of premenopausal women, we explored the association of polymorphisms in genes in the estrogen synthesis and metabolism pathways with serum and urinary levels of estrone (E1) and estradiol (E2) and with the urinary ratio of 2-hydroxyestrone (2-OHE1)/16alpha-hydroxyestrone (16alpha-OHE1). This analysis included 220 women, who were participants in a 2-year randomized soy intervention. Blood specimens were collected in the luteal phase of the menstrual cycle an average of 4.4 times over 2 years. Overnight urinary specimens were collected on the same cycle day, only at baseline. Levels of E1, E2, 2-OHE1, and 16alpha-OHE1 were measured by enzyme immunoassays. The DNA samples were analyzed by PCR/RFLP for the COMT Val158Met, CYP1A1*2A, CYP1A1*2B, CYP1A2*1F, CYP1B1 Val432Leu, and CYP17 T27C polymorphisms. We applied mixed models to investigate the relations between genotypes and repeated serum hormone measurements and generalized linear models to assess associations between genotypes and urinary estrogen metabolites. The CYP1A2 C allele was significantly associated with lower serum E2 levels; in CC genotype carriers, serum E2 levels were 26.3% lower than in homo- and heterozygous common allele carriers combined (P = 0.01). CYP1A2*1F also affected the urinary 2-OHE1/16alpha-OHE1 ratio; carriers of the variant C allele had a markedly lower ratio than individuals with the AA genotype (1.37 versus 1.76; P = 0.002). These data suggest that CYP1A2*1F is associated with lower circulating levels of E2, and that it may be a susceptibility locus for breast cancer. 相似文献
9.
Svetlana Popova Victoria Tazetdinova Erzhena Pavlova Galina Matafonova Valeriy Batoev 《Materials》2022,15(15)
Naturally occurring sono- and photoactive minerals, which are abundant on Earth, represent an attractive alternative to the synthesized sonophotocatalysts as cost-effective materials for water and wastewater treatment. This study focuses on characterizing and evaluating the sonophotocatalytic activity of natural sphalerite (NatS) from Dovatka deposit (Siberia) under high-frequency ultrasonic (US, 1.7 MHz) and ultraviolet light-emitting diodes (UVA LED, 365 nm) irradiation towards degradation of 4-chlorophenol as a model organic pollutant. Since raw natural sphalerite did not exhibit a measurable photocatalytic activity, it was calcined at 500, 900 and 1200 °C. The natural sphalerite after calcination at 900 °C (NatS*) was found to be the most effective for sonophotocatalytic degradation of 4-chlorophenol, attaining the highest efficiency (55%, 1 h exposure) in the following row: UV < US ≈ UV/US ≈ US/NatS* < UV/NatS* < UV/US/NatS*. Addition of 1 mM H2O2 increased the removal to 74% by UV/US/NatS*/H2O2 process. An additive effect between UV/NatS* and US/NatS* processes was observed in the sonophotocatalytic system as well as in the H2O2-assisted system. We assume that the sonophotocatalytic hybrid process, which is based on the simultaneous use of high-frequency ultrasound, UVA light, calcined natural sphalerite and H2O2, could provide a basis of an environmentally safe and cost-effective method of elimination of organic pollutants from aqueous media. 相似文献
10.
The composition, structure, and protective and hydrophobic properties of nanoscale films formed layer-by-layer in solutions of sodium dodecylphosphonate (SDDP) and vinyltrimethoxysilane or n-octyltriethoxysilane (OTES) on the zinc surface with different morphologies were studied by SEM, XPS, water contact angle measurements, and electrochemical and corrosion tests. The protective, hydrophobic properties of phosphonate–siloxane films on zinc and their stability in a corrosive media are determined both by the initial surface morphology and composition of the surface oxide layer, and by the nature of inhibitors. It was shown that preliminary laser texturing of the zinc surface is preferable than chemical etching to enhance the anticorrosive properties of the resulting thin films. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray are formed on the zinc surface with fractal morphology during layer-by-layer passivation with SDDP and OTES. 相似文献