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31.
TLHS1 is a class I low molecular weight heat-shock protein (LMW HSP) of tobacco (Nicotiana tabacum). For a functional study of TLHS1, a recombinant DNA coding for TLHS1 with a hexahistidine tag at the aminoterminus was constructed and expressed in Escherichia coli. An expressed fusion protein, H6TLHS1, was purified using a Ni2+ affinity column and a Sephacryl S400 HR column. A polyclonal antibody against H6TLHS1 was produced to follow the fate of H6TLHS1 in E. coli. The fusion protein in E. coli maintained its solubility at a temperature of up to 90°C and most of the proteins in the E. coli cell lysate with H6TLHS1 were prevented from thermally induced aggregation at up to 90°C. We compared the viability of E. coli cells expressing H6TLHS1 to the E. coli cells without H6TLHS1 at a temperature of 50°C. After 8 h of high temperature treatment, E. coli cells with H6TLHS1 survived about three thousand times more than the bacterial cells without H6TLHS1. These results showed that a plant class I LMW HSP, TLHS1, can protect proteins of E. coli from heat denaturation, which could lead to a higher survival rate of the bacterial cells at high temperature. 相似文献
32.
Domenica Farci Matthew W. Bowler Joanna Kirkpatrick Sean McSweeney Enzo Tramontano Dario Piano 《生物化学与生物物理学报:生物膜》2014
We have analyzed the cell wall of the radio-resistant bacterium Deinococcus radiodurans. Unexpectedly, the bacterial envelope appears to be organized in different complexes of high molecular weight. Each complex is composed of several proteins, most of which are coded by genes of unknown function and the majority are constituents of the inner/outer membrane system. One of the most abundant complexes is constituted by the gene DR_0774. This protein is a type of secretin which is a known subunit of the homo-oligomeric channel that represents the main bulk of the type IV piliation family. Finally, a minor component of the pink envelope consists of several inner-membrane proteins. The implications of these findings are discussed. 相似文献
33.
Sperm production and mating potential of males after a cold shock on pupae of the parasitoid wasp Dinarmus basalis (Hymenoptera: Pteromalidae) 总被引:1,自引:0,他引:1
For ectothermic species, temperature is a key environmental factor influencing several aspects of their physiology and ecology, acting particularly on reproduction. To measure the consequences of a severe thermal stress during development on male reproduction, a cold shock (1h at -18 degrees C) was tested on Dinarmus basalis pupae. D. basalis (Hymenoptera: Pteromalidae) is a parasitoid wasp in which sperm management in both male and female is of prime importance. After a cold shock, developmental success was reduced, with a quarter of cold-shocked males not emerging correctly. The stress effects were estimated at the level of sperm stock in seminal vesicles of males at different ages and on the ability of 2-day-old males to access females in single and multiple mating and in male-male competition. Cold-shocked males had a reduced sperm stock compared to control males and this difference persisted with age. The rate of sperm production was similar in both groups. The consequences of a cold shock on male reproductive ability were perceptible in multiple mating and male-male competition but not in single mating. Cold-shocked males were at a disadvantage, inseminating fewer females and copulating less frequently. Finally, male pupae of D. basalis were able to withstand severe temperature stresses and their reproductive functions were partially preserved. 相似文献
34.
Roy S Khanna V Mittra S Dhar A Singh S Mahajan DC Priyadarsiny P Davis JA Sattigeri J Saini KS Bansal VS 《Life sciences》2007,81(1):72-79
Thiazolidinediones (TZDs) are currently the most efficacious class of oral antidiabetics. However, they carry the burden of weight gain and haemodilution, which may lead to cardiovascular complications. The present study was designed to ascertain whether a combination of dipeptidyl peptidase IV (DPP IV) inhibitor with low dose of a thiazolidinedione absolves TZD associated weight gain and oedema without compromising its efficacy. In this study, we examined the efficacy and safety of lower dose (1 mg/kg/day) of rosiglitazone, a thiazolidinedione, in combination with 5 mg/kg/day dose of LAF-237 (vildagliptin), a known DPP IV inhibitor, in aged db/db mice after 14 days of treatment and compared the combination with therapeutic dose (10 mg/kg) of rosiglitazone. The combination therapy showed similar efficacy as that of 10 mg/kg/day rosiglitazone in lowering random blood glucose (53.8%, p<0.001 and 54.3%, p<0.001 respectively), AUC ((0-120) min) during oral glucose tolerance test (OGTT) (38.6 %, p<0.01; 38.3%, p<0.01 respectively) and triglyceride levels (63.9% and 61% respectively; p<0.01). Plasma active glucagon like peptide-1 (GLP-1) and insulin levels were found to be elevated significantly (p<0.01 and p<0.05 respectively) in both LAF-237 and combination treated groups following oral glucose load. LAF-237 alone had no effect on random glucose and glucose excursion during OGTT in severely diabetic db/db mice. Interestingly, the combination treatment showed no significant increase in body weight as compared to the robust weight gain by therapeutic dose of rosiglitazone. Rosiglitazone at 10 mg/kg/day showed significant reduction (p<0.05) in haematocrit, RBC count, haemoglobin pointing towards haemodilution associated with increased mRNA expression of Na(+), K(+)-ATPase-alpha and epithelial sodium channel gamma (ENaCgamma) in kidney. The combination therapy escaped these adverse effects. The results suggest that combination of DPP IV inhibitor with low dose of thiazolidinedione can interact synergistically to represent a therapeutic advantage for the clinical treatment of type 2 diabetes without the adverse effects of haemodilution and weight gain associated with thiazolidinediones. 相似文献
35.
Tettamanti G Grimaldi A Casartelli M Ambrosetti E Ponti B Congiu T Ferrarese R Rivas-Pena ML Pennacchio F Eguileor Md 《Cell and tissue research》2007,330(2):345-359
We have analyzed midgut development during the fifth larval instar in the tobacco budworm Heliothis virescens. In prepupae, the midgut formed during larval instars undergoes a complete renewal process. This drastic remodeling of the
alimentary canal involves the destruction of the old cells by programmed cell-death mechanisms (autophagy and apoptosis).
Massive proliferation and differentiation of regenerative stem cells take place at the end of the fifth instar and give rise
to a new fully functioning epithelium that is capable of digesting and absorbing nutrients and that is maintained throughout
the subsequent pupal stage. Midgut replacement in H. virescens is achieved by a balance between this active proliferation process and cell-death mechanisms and is different from similar
processes characterized in other insects.
This work was supported by FAR 2006 (University of Insubria) to G.T., by a MIUR-FIRB-COFIN grant (no. RBNE01YXA8/2004077251),
and by the Centro Grandi Attrezzature (University of Insubria). 相似文献
36.
John M. Casselman 《Environmental Biology of Fishes》2007,79(1-2):137-154
Growth and ultimate size can provide important population insights and a sound biological basis for setting length limits,
which can be the best single regulation for preventing overexploitation of muskellunge (Esox masquinongy) populations. A system was developed, using cleithral age and total length at age confidence limits (CL) data, to determine
reproductive and growth potential (ultimate size) for calculating and setting increased size limits based on minimum reproductive
size (upper 99% CL at age at first maturity + 2 year) and minimum ultimate size (MUS) calculated from the lower 99% CL—minimum
ultimate size limit (MUSL). MUS also provides a trophy standard and an index of relative size for comparing trophy potential
of individuals within and among populations. Guidelines are provided for determining minimum sample size (mean ± 95% confidence
interval = 12 ± 4) and minimum age (8–10 ± 2.0 year) required to produce valid von Bertalanffy growth trajectories. MUS, MUSL,
and trophy standards for both length and estimated weight are provided for female and male muskellunge from 14 Ontario sources.
Mean MUS, or trophy standard, for females was 115 ± 10.3 cm (MUSL range 75–135) and 11.1 ± 2.6 kg (2.5–17.5) and for males
was 95 ± 7.5 cm (66–110) and 6.1 ± 1.3 kg (1.9–9.2). These indices can precisely define growth and growth potential for muskellunge
populations and individuals and can be used to better manage and maintain or improve the quality of muskellunge populations
and fisheries.
Dedicated to the late Dr. E.J. Crossman. 相似文献
37.
Mojca Gorenc Nada Rotovnik Kozjek Primo? Strojan 《Reports of Practical Oncology and Radiotherapy》2015,20(4):249-258
AimTo highlight the problems associated with nutrition that occur in patients with squamous cell carcinoma of the head and neck (SCCHN).BackgroundSCCHN is associated with weight loss before, during and after radiotherapy or concurrent chemoradiotherapy. Because of serious consequences of malnutrition and cachexia on treatment outcome, mortality, morbidity, and quality of life, it is important to identify SCCHN patients with increased risk for the development of malnutrition and cachexia.Materials and methodsCritical review of the literature.ResultsThis review describes pathogenesis, diagnosis and treatment of malnutrition and cancer cachexia. Treatment of malnutrition and cancer cachexia includes nutritional interventions and pharmacological therapy. Advantages and disadvantages of different nutritional interventions and their effect on the nutritional status, quality of life and specific oncological treatment are presented.ConclusionsNutritional management is an essential part of care of these patients, including early screening, assessment of nutritional status and appropriate intervention. 相似文献
38.
39.
FXPRLamide peptides encoded by the DH-PBAN (diapause hormone-pheromone biosynthesis activating neuropeptide) gene induce embryonic diapause in Bombyx mori, but terminate pupal diapause in Helicoverpa armigera (Har). Here, we explore the mechanisms of terminating pupal diapause by the FXPRLamide peptides. Using quantitative RT-PCR, we observed that expression of Har-DH-PBAN mRNA in the SG of nondiapause-type pupae was significantly higher than in diapause-type pupae. Immunocytochemical results indicated that the level of FXPRLamide peptides and axonal release are related to the diapause decision. Ecdysteroidogenesis in prothoracic glands (PGs) was stimulated by synthetic Har-DH in vivo and in vitro, and labeled Har-DH bound to the membrane of the PG, thus suggesting that DH breaks diapause by activating the PG to synthesize ecdysone. Furthermore, the response of DH in terminating diapause was temperature dependent. Decerebration experiments showed that the brain can control pupal development through the regulation of DH, and DH can terminate diapause and promote development without the brain. This result suggests a possible mechanism of response for the signals of DH and other FXPRLamide peptides in H. armigera. 相似文献