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421.
An anti-viral factor (PARFa), related to the ‘periodic acquisition’ phenomenon of the tomato yellow leaf curl virus (TYLCV) by the tobacco whitefly, was investigated by ion-exchange chromatography and some of its properties were determined. Separating crude PARFa on a DEAE-cellulose column revealed the presence of two different active fractions. Both fractions were found to occur periodically in the vector's body in concurrence with TYLCV inoculability.PARFa was sensitive to temperatures over 35°C, resistant to pH changes in the range of 2·2 to 9·0 and to RNase, but lost its activity after exposure to pronase.  相似文献   
422.
The extent of inhibition of cotton-seed germination by lucernesaponins depends upon the period of pre-immersion in the saponinsolution prior to germination. After 5 hr of pre-immersion ina 0.5% lucerne saponin solution, a 40% drop in germination wasnoted. The respiration rate decreased after 3 hr of pre-immersion.The diffusion of oxygen through the membranes of seeds pre-immersedin saponins also decreased with an increasing pre-immersiontime. Inhibition of germination was irreversible after pre-immersionin saponins for 6 hr or more. The effect of saponins does not appear to be biochemically specificbecause the germination and respiration rates of the cottonseeds which were immersed in aqueous solutions of anionic, nonionicor cationic commercial surfactants were similarly inhibited. (Received February 19, 1975; )  相似文献   
423.
The entire mouse cDNA sequence for type XIV collagen was determined using overlapping PCR products. The 6456 nucleotide (nt) cDNA sequence contains a 5391-nt open reading frame encoding 1797 amino acid residues. The amino terminus has a 28-residue signal peptide that is followed by the mature polypeptide of 1769 amino acid residues with a calculated molecular mass of 193.2 kDa. The mouse alpha1(XIV) collagen chain is predicted to contain all the structural domains described for the polypeptide in chicken and human. These include fibronectin type III repeats, von Willebrand factor A domains, thrombospondin-N-terminal-like domains and two triple-helical domains similar to those of other collagen family members. The amino acid residue sequence of human alpha1(XIV) collagen showed an overall identity of 74% to the chicken sequence and 88% to the human sequence. The entire mouse genomic structure has been determined and is made up of 48 exons. Alternatively spliced forms of mouse type XIV, collagen were not identified corresponding to the findings for the human form.  相似文献   
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The offspring of parents with mental disorders are at increased risk for developing mental disorders themselves. The risk to offspring may extend transdiagnostically to disorders other than those present in the parents. The literature on this topic is vast but mixed. To inform targeted prevention and genetic counseling, we performed a comprehensive, PRISMA 2020-compliant meta-analysis. We systematically searched the literature published up to September 2022 to retrieve original family high-risk and registry studies reporting on the risk of mental disorders in offspring of parents with any type of mental disorder. We performed random-effects meta-analyses of the relative risk (risk ratio, RR) and absolute risk (lifetime, up to the age at assessment) of mental disorders, defined according to the ICD or DSM. Cumulative incidence by offspring age was determined using meta-analytic Kaplan-Meier curves. We measured heterogeneity with the I2 statistic, and risk of bias with the Quality In Prognosis Studies (QUIPS) tool. Sensitivity analyses addressed the impact of study design (family high-risk vs. registry) and specific vs. transdiagnostic risks. Transdiagnosticity was appraised with the TRANSD criteria. We identified 211 independent studies that reported data on 3,172,115 offspring of parents with psychotic, bipolar, depressive, disruptive, attention-deficit/hyperactivity, anxiety, substance use, eating, obsessive-compulsive, and borderline personality disorders, and 20,428,575 control offspring. The RR and lifetime risk of developing any mental disorder were 3.0 and 55% in offspring of parents with anxiety disorders; 2.6 and 17% in offspring of those with psychosis; 2.1 and 55% in offspring of those with bipolar disorder; 1.9 and 51% in offspring of those with depressive disorders; and 1.5 and 38% in offspring of those with substance use disorders. The offspring's RR and lifetime risk of developing the same mental disorder diagnosed in their parent were 8.4 and 32% for attention-deficit/hyperactivity disorder; 5.8 and 8% for psychosis; 5.1 and 5% for bipolar disorder; 2.8 and 9% for substance use disorders; 2.3 and 14% for depressive disorders; 2.3 and 1% for eating disorders; and 2.2 and 31% for anxiety disorders. There were 37 significant transdiagnostic associations between parental mental disorders and the RR of developing a different mental disorder in the offspring. In offspring of parents with psychosis, bipolar and depressive disorder, the risk of the same disorder onset emerged at 16, 5 and 6 years, and cumulated to 3%, 19% and 24% by age 18; and to 8%, 36% and 46% by age 28. Heterogeneity ranged from 0 to 0.98, and 96% of studies were at high risk of bias. Sensitivity analyses restricted to prospective family high-risk studies confirmed the pattern of findings with similar RR, but with greater absolute risks compared to analyses of all study types. This study demonstrates at a global, meta-analytic level that offspring of affected parents have strongly elevated RR and lifetime risk of developing any mental disorder as well as the same mental disorder diagnosed in the parent. The transdiagnostic risks suggest that offspring of parents with a range of mental disorders should be considered as candidates for targeted primary prevention.  相似文献   
427.
In the ER (endoplasmic reticulum) of human cells, disulfide bonds are predominantly generated by the two isoforms of Ero1 (ER oxidoreductin-1): Ero1α and Ero1β. The activity of Ero1α is tightly regulated through the formation of intramolecular disulfide bonds to help ensure balanced ER redox conditions. Ero1β is less tightly regulated, but the molecular details underlying control of activity are not as well characterized as for Ero1α. Ero1β contains an additional cysteine residue (Cys262), which has been suggested to engage in an isoform-specific regulatory disulfide bond with Cys100. However, we show that the two regulatory disulfide bonds in Ero1α are likely conserved in Ero1β (Cys90–Cys130 and Cys95–Cys100). Molecular modelling of the Ero1β structure predicted that the side chain of Cys262 is completely buried. Indeed, we found this cysteine to be reduced and partially protected from alkylation in the ER of living cells. Furthermore, mutation of Cys100–but not of Cys262–rendered Ero1β hyperactive in cells, as did mutation of Cys130. Ero1β hyperactivity induced the UPR (unfolded protein response) and resulted in oxidative perturbation of the ER redox state. We propose that features other than a distinct pattern of regulatory disulfide bonds determine the loose redox regulation of Ero1β relative to Ero1α.  相似文献   
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It has been proposed that the hepatitis C virus (HCV) internal ribosome entry site (IRES) resides within a locked conformation, owing to annealing of its immediate flanking sequences. In this study, structure probing using Escherichia coli dsRNA-specific RNase III and other classical tools showed that this region switches to an open conformation triggered by the liver-specific microRNA, miR-122. This structural transition, observed in vitro, may be the mechanistic basis for the involvement of downstream IRES structural domain VI in translation, as well as providing a role of liver-specific miR-122 in HCV infection. In addition, the induced RNA switching at the 5′ untranslated region could ultimately represent a new mechanism of action of micro-RNAs.  相似文献   
430.
Polyclonal antibodies were produced against trypsin-like enzyme TLE-2, one of two trypsins isolated from the midgut cecae of the locust Locusta migratoria. Using those antibodies a heterologous RIA was developed. The specificity of the antibodies was demonstrated by immunoblot technique and cross-reactivity experiments. Positive blot reaction with the antiserum was observed with locust trypsins and binding competition was obtained only with the second trypsin from the locust, TLE-1. Trypsins from bovine and hog as well as trypsins from Tenebrio molitor and Tribolium castaneum and locust chymotrypsin did not inhibit TLE-2 binding to the antiserum even at concentrations 1,000-fold greater than that of locust TLE-2. The concentrations of TLE-2 in cecal fluid, cecal wall, hemolymph, and fat-body were 2,790, 60.4, 6.4, and 0.7 ng per mg tissue, respectively. © 1992 Wiley-Liss, Inc.  相似文献   
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