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1.
Jaroslava Mal Frantisek Sehnal A. Krishna Kumaran Noelle A. Granger 《Archives of insect biochemistry and physiology》1987,4(2):113-128
Starvation, chilling, and injury of last instar Galleria mellonella larvae typically elicit extra larval molts or a delay in pupation. The primary sites of action and the nature of the signals by which these treatments affect development are not known. However, since the connections of the brain to the nerve cord are crucial for the effects of starvation and chilling, these signals apparently affect the brain-centered program of developmental regulation via the nerve cord. Chilling, and occasionally starvation, cause extra larval molts in last instar larvae treated prior to the nervous inhibition of their corpora allata; release of a cerebral allatotropin, which stimulates the production of juvenile hormone, appears to be involved in this effect. After this time, a delay in pupation is the principal effect of starvation and chilling, and is apparently due to a temporal inhibition of the release of the prothoracicotropic hormone. Chilling also appears to inhibit unstimulated ecdysteroid production by the prothoracic glands. The effect of injury is not mediated by the nerve cord, but appears to involve an inhibitory humoral factor that affects either the brain or the prothoracic glands themselves. Injury also stimulates juvenile hormone production, an effect which is enhanced when the brain is separated from the nerve cord and which is evidenced by a delay of ecdysis and the occasional retention of some larval features in the ecdysed insects. None of the effects of these various treatments on the brain and the endocrine glands persist when the brains or glands are implanted into untreated hosts. 相似文献
2.
Summary Confined placental chorionic mosaicism is reported in 2% of viable pregnancies cytogenetically analyzed on chorionic villi samplings (CVS) at 9–12 weeks of gestation. In follow-up studies this mosaicism has been shown to be associated with increased frequency of second and third trimester pregnancy loss or intrauterine fetal growth retardation. We have studied 54 spontaneous abortions (SA) for the detection of confined placental mosaicism and found 11 of them to be mosaic. All mosaic cases were identified among first trimester spontaneous abortions, and the mosaicism was confined to specific placental or embryonic/fetal cell lineages. These results indicate that the previously reported mosaicism in SA represents both confined and generalized types of mosaicism and that its accepted frequency of 5%–10% in SA will likely be higher. Over the whole gestational period, the confined placental mosaicism is more common than the reported rate of 1%–2% seen in viable pregnancies at CVS, and a higher proportion of pregnancy complications than previously suspected may be associated with confined placental mosaicism. 相似文献
3.
Subregional assignment of the linked marker G8 (D4S10) for Huntington disease to chromosome 4p16.1-16.3. 总被引:3,自引:3,他引:0
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H S Wang C R Greenberg J Hewitt D Kalousek M R Hayden 《American journal of human genetics》1986,39(3):392-396
The linked DNA marker for Huntington disease has recently been mapped to the short arm of chromosome 4 by somatic cell hybridization studies. Southern blot analysis of DNA from patients with Wolf-Hirschhorn syndrome (WHS) has suggested that the linked marker maps within the terminal 4p16 band. We have now accomplished subregional assignment of G8 (D4S10) to 4p16.1-16.3 using in situ hybridization techniques on two patients with nonoverlapping interstitial deletions of 4p. The mapping of G8 (D4S10) to a region deleted in patients with WHS will allow the application of new strategies for detecting DNA sequences closer to the locus for Huntington disease. 相似文献
4.
Treatment of rabies virus with the nonionic detergent Nonidet P-40 resulted in solubilization of viral lipids and in a preferential release of the envelope glycoprotein. The other viral proteins and the viral ribonucleic acid remained associated in "core" particles sedimenting at a rate similar to that of intact virions. After fractionation of treated virus by velocity centrifugation in a sucrose density gradient, the amount of residual glycoprotein recovered in the "core" particle fraction and the extent of contamination of the glycoprotein fraction by other viral components were dependent on the ratio of detergent to viral protein used. 相似文献
5.
Isolation and characterization of propionyl-CoA carboxylase from normal human liver. Evidence for a protomeric tetramer of nonidentical subunits 总被引:9,自引:0,他引:9
We have purified propionyl-CoA carboxylase from normal, postmortem human liver to homogeneity. The isolation procedure, which provided an approximately 3000-fold purification and an overall yield of 26%, employed initial centrifugation of a cetyltrimethylammonium bromide-treated homogenate, followed by sequential chromatographic separations using DEAE-cellulose, Blue Sepharose, and Bio-Gel A-1.5m. The native enzyme has a molecular weight of approximately 540,000 and is composed of nonidentical subunits (alpha and beta) of Mr = 72,000 and 56,000, respectively. When studied with analytical isoelectrofocusing techniques, it focuses as a single peak at pH 5.5. Each mole of native enzyme contains 4 mol of bound biotin, virtually all of which is found with the larger (alpha) subunit. The apparent Km values for ATP, propionyl-CoA, and bicarbonate are 0.08 mM, 0.29 mM, and 3.0 mM, respectively. The enzyme also catalyzes the carboxylation of acetyl-CoA and butyryl-CoA to a limited degree, but not that of crotonyl-CoA. Propionyl-CoA carboxylase is quite stable over a temperature range from -50--37 degrees C and over a pH range from 6.2 to 8.4. It has a broad pH optimum from pH 7.2 to 8.8. Limited proteolysis with trypsin results in slow, time-dependent deactivation of the enzyme with preferential cleavage of the smaller subunit. Antiserum prepared against the native enzyme is shown to be monospecific by immunodiffusion and immunoelectrophoresis. 相似文献
6.
Lucia Mala Mikulas Hank Petr Stastny Frantisek Zahalka Kevin R. Ford Piotr Zmijewski David Bujnovsky Miroslav Petr Tomas Maly 《Biology of sport / Institute of Sport》2023,40(1):265
Body composition (BC) and inter-limb anthropometric asymmetries (LA) may influence the physical performance of soccer players. This study aimed to determine differences in BC and LA among soccer across four performance levels. The study involved 110 male soccer players participating in Czech senior teams who were grouped into four different performance levels (i.e. G1: national team, G2: 1st division, G3: 2nd division, G4: 3rd division). The following BC and LA parameters were compared among groups: body height, body mass, absolute fat-free mass, relative fat-free mass (FFMrel), percentage of fat mass (FM), total body water (TBW), intracellular water (ICW), extracellular water (ECW), phase angle, and bilateral muscle mass differences in the upper and lower extremities. Significant differences were observed in BC parameters among all groups (λ = 0.06, F75,246 = 5.38, p = 0.01, ηp2 = 0.62). High-performance players (i.e. G1, G2) had significantly (p < 0.01) lower FM than lower performance players (i.e. G3, G4). The lowest values of FFMrel, relative TBW, relative ICW and ECW were detected in the lowest-performance players (i.e. G4). Significantly lower bilateral muscle mass differences were detected in G1 players (2.71 ± 1.26%; p < 0.01) compared with G4 players (3.95 ± 1.17%). G1 and G2 players had a higher proportion of muscle mass in the torso (p < 0.01) and upper limbs than G3 and G4 (p < 0.01). Elite and high-performance players have better BC and lower inter-limb anthropometric asymmetries compared with low-performance level players. 相似文献
7.
Jakub Hofman Radim Ku?era Daniela Cihalova Jiri Klimes Martina Ceckova Frantisek Staud 《PloS one》2013,8(10)
Purine cyclin-dependent kinase inhibitors have been recognized as promising candidates for the treatment of various cancers; nevertheless, data regarding interaction of these substances with drug efflux transporters is still lacking. Recently, we have demonstrated inhibition of breast cancer resistance protein (ABCG2) by olomoucine II and purvalanol A and shown that these compounds are able to synergistically potentiate the antiproliferative effect of mitoxantrone, an ABCG2 substrate. In this follow up study, we investigated whether olomoucine II and purvalanol A are transported by ABCG2 and ABCB1 (P-glycoprotein). Using monolayers of MDCKII cells stably expressing human ABCB1 or ABCG2, we demonstrated that olomoucine II, but not purvalanol A, is a dual substrate of both ABCG2 and ABCB1. We, therefore, assume that pharmacokinetics of olomoucine II will be affected by both ABCB1 and ABCG2 transport proteins, which might potentially result in limited accumulation of the compound in tumor tissues or lead to drug-drug interactions. Pharmacokinetic behavior of purvalanol A, on the other hand, does not seem to be affected by either ABCG2 or ABCB1, theoretically favoring this drug in the potential treatment of efflux transporter-based multidrug resistant tumors. In addition, we observed intensive sulfatation of olomoucine II in MDCKII cell lines with subsequent active efflux of the metabolite out of the cells. Therefore, care should be taken when performing pharmacokinetic studies in MDCKII cells, especially if radiolabeled substrates are used; the generated sulfated conjugate may largely contaminate pharmacokinetic analysis and result in misleading interpretation. With regard to chemical structures of olomoucine II and purvalanol A, our data emphasize that even drugs with remarkable structure similarity may show different pharmacokinetic behavior such as interactions with ABC transporters or biotransformation enzymes. 相似文献
8.
Petra Ondrackova Hana Kovaru Frantisek Kovaru Lenka Leva Martin Faldyna 《Cytokine》2013,61(3):953-961
Adenosine plays an important role during inflammation, particularly through modulation of monocyte function. The objective of the present study was to evaluate the effect of synthetic adenosine analogs on cytokine production by porcine monocytes. The LPS-stimulated cytokine production was measured by flow cytometry and quantitative real-time PCR. Adenosine receptor expression was measured by quantitative real-time PCR. The present study demonstrates that adenosine analog N-ethylcarboxyamidoadenosine (NECA) down-regulates TNF-α production and up-regulates IL-8 production by LPS-stimulated porcine monocytes. The effect was more pronounced in CD163? subset of monocytes compared to the CD163+ subset. Although both monocyte subsets express mRNA for A1, A2A, A2B and A3 adenosine receptors, the treatment of monocytes with various adenosine receptor agonists and antagonists proved that the effect of adenosine is mediated preferentially via A2A adenosine receptor. Moreover, the study suggests that the effect of NECA on porcine monocytes alters the levels of the cytokines which could play a role in the differentiation of naive T cells into Th17 cells. The results suggest that adenosine plays an important role in modulation of cytokine production by porcine monocytes. 相似文献
9.
Lucia Vernerova Frantisek Spoutil Miroslav Vlcek Katarina Krskova Adela Penesova Milada Meskova Andrea Marko Katarina Raslova Branislav Vohnout Jozef Rovensky Zdenko Killinger Ivana Jochmanova Ivica Lazurova Guenter Steiner Josef Smolen Richard Imrich 《PloS one》2016,11(4)
IntroductionThe aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).MethodsA total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.ResultsHLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.ConclusionsThe association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA. 相似文献
10.