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101.
G. M. Budd J. R. Brotherhood D. W. Thomas F. A. Beasley A. L. Hendrie S. E. Jeffery G. J. Lincoln A. T. Solaga 《European journal of applied physiology and occupational physiology》1993,67(5):450-456
The purpose of this study was to see whether artificial acclimatization to cold would reduce the pressor response to noradrenaline (NA) as natural acclimatization has been shown to do, and whether it would induce nonshivering thermogenesis. Three white men were infused with NA at four dosage levels between 0.038 and 0.300 g·kg–1·min–1 (2–23 g·min–1), before and after artificial acclimatization to cold and again 4 months later when acclimatization had decayed. Acclimatization was induced by ten daily cold (15°Q baths of 30–60 min followed by rapid rewarming in hot (38–42°C) water, and was confirmed by tests of the subjects responses to whole-body cooling in air. Three control subjects also underwent the first and third tests. Acclimatization substantially reduced the pressor response to NA at 0.150 and 0.300 g·kg–1·min–1, confirming earlier findings by the same technique in naturally acclimatized men, and its decay increased this response to beyond its initial levels (P<0.05 for both changes). Acclimatization did not change the response to NA of heart rate, subjective impressions, skin temperature of finger and toe, pulmonary ventilation, or plasma free fatty acids and ketone bodies. At no time did NA increase oxygen consumption, or increase skin temperature or heat flow over reported sites of brown fat. These findings would seem to show that acclimatization to cold reduces sensitivity to the pressor effect of NA but does not induce nonshivering thermogenesis, and that the reduced sensitivity is replaced by a hypersensitivity to NA when acclimatization decays. 相似文献
102.
Eric W. Slessarev Allegra Mayer Courtland Kelly Katerina Georgiou Jennifer Pett-Ridge Erin E. Nuccio 《Global Change Biology》2023,29(5):1239-1247
Changes in soil organic carbon (SOC) storage have the potential to affect global climate; hence identifying environments with a high capacity to gain or lose SOC is of broad interest. Many cross-site studies have found that SOC-poor soils tend to gain or retain carbon more readily than SOC-rich soils. While this pattern may partly reflect reality, here we argue that it can also be created by a pair of statistical artifacts. First, soils that appear SOC-poor purely due to random variation will tend to yield more moderate SOC estimates upon resampling and hence will appear to accrue or retain more SOC than SOC-rich soils. This phenomenon is an example of regression to the mean. Second, normalized metrics of SOC change—such as relative rates and response ratios—will by definition show larger changes in SOC at lower initial SOC levels, even when the absolute change in SOC does not depend on initial SOC. These two artifacts create an exaggerated impression that initial SOC stocks are a major control on SOC dynamics. To address this problem, we recommend applying statistical corrections to eliminate the effect of regression to the mean, and avoiding normalized metrics when testing relationships between SOC change and initial SOC. Careful consideration of these issues in future cross-site studies will support clearer scientific inference that can better inform environmental management. 相似文献
103.
The immunogenicity of recombinant interleukin-2 (rIL-2, EuroCetus, Amsterdam, Netherlands) was studied in seventy-six patients receiving different subcutaneous immunotherapy regimens. Patients presented with progressive metastatic renal cell carcinoma, malignant melanoma, colorectal cancer, B-cell lymphoma, and Hodgkin's disease. An enzyme immunoassay (EIA) was employed to screen patients for development of non-neutralizing antibodies against rIL-2, antibody specificity was confirmed by a standard Western blot. Neutralizing serum activity against rIL-2 was detected using a standard CTLL mouse proliferation assay. Additionally, serum levels of soluble interleukin-2 receptors and lymphocyte subsets expressing the CD56 natural killer (NK) associated antigen were measured.In a proportion of approximately 35% to 90% of the patients treated, non-neutralizing antibodies against rIL-2 could be detected after all treatment courses were evaluated. Antibodies were of the IgG, IgM, IgA and IgD subtypes. None of the 76 patients exhibited serum neutralizing activity after one treatment course. Five patients exhibited neutralizing anti-rIL-2 serum activity after two or more treatment courses of systemic rIL-2. In three of these patients, antibodies neutralized both recombinant and natural IL-2. Patients developing neutralizing anti-rIL-2 antibodies, exhibited significantly lower serum sIL-2 receptor levels upon the emergence of serum neutralizing activity than patients without antibody. Additionally, NK cell associated CD56 positivity was significantly lower in patients who exhibited neutralizing anti-rIL-2 serum activity than in patients who did not. A significant decrease in levels of soluble IL-2 receptors and CD56 NK cell positivity was observed, when comparing values prior to and after onset of serum neutralizing activity against rIL-2. However, while emergence of neutralizing antibodies to rIL-2 diminished rIL-2 induced biological activation, it did not coincide with abrogation of treatment response.Abbreviations rIL-2
recombinant interleukin-2
- EIA
enzyme immuno assay
- rIFN-2
recombinant interferon- 2 相似文献
104.
105.
Abstract This paper describes four new species of Coenosia Meigen, 1826, namely C. angustifolia sp.nov., C. obscuriabdominis sp. nov., C. sparagmocerca sp. nov. and C. sponsa sp. nov. Type specimens are deposited in Institute of Entomology, Shenyang Normal University, Shenyang, China. 相似文献
106.
K. Sudha Rani M. V. Swamy D. Sunitha D. Haritha G. Seenayya 《World journal of microbiology & biotechnology》1996,12(1):57-60
Two Clostridium thermocellum strains were improved for ethanol tolerance, to 5% (v/v), by gradual adaptation and mutation. The best mutant gave an ethanol yield of 0.37 g/g substrate, with a growth yield 1.5 times more than its parent. Accumulation of acids and reducing sugars by the mutant strain with 5% (v/v) ethanol was lower than that of the parent strain with 1.5% (v/v) ethanol. 相似文献
107.
Abstract The present paper deals with a new species Habrophlebiodes zijinensis sp. nov. collected in Nanjing, Jiangsu Povince, China. 相似文献
108.
Determination of anteroposterior and dorsoventral axes is an important early event in the development of vertebrates involving
extensive cellular interactions including inductive events. Recently we showed that insulin plays an essential role in prepancreatic
development of the frogMicrohyla ornata. In the present study we have investigated the effects of immunoneutralization of endogenous insulin on the process of pattern
formation. Treatment of neurulating embryos with antiserum to insulin caused abnormal pattern formation. The defects included
loss of normal architecture of the neural tube, reduction in the size of the neural tube and, most conspicuously, rotation
of the dorsoventral axis of the neural tube, notochord and adjoining mesodermal elements. The effects could be alleviated
partially by pretreatment of embryos with exogenous insulin. This supports our belief that insulin plays an important role
in induction and pattern formation of the amphibian nervous system.
In addition, using 2-deoxy-α-D-glucose, an inhibitor of glucose metabolism, it is shown that the stimulatory effects of exogenous
insulin on developing frog embryos are, at least partially, through the glucose metabolism pathway.
Preliminary results of this study were presented at the National Symposium on Genes and Human Environment, held at Hyderabad,
February 1994 and DAE Symposium on Stress and Adaptive Responses in Biological Systems, held at Vadodara, March 1994. 相似文献
109.
Interferon antibodies in patients with infectious diseases 总被引:2,自引:0,他引:2
G. Antonelli E. Simeoni M. Currenti F. De Pisa V. Colizzi M. Pistello F. Dianzani 《Biotherapy》1997,10(1):7-14
Interferons (IFNs) are generally recognized as the most important therapeutic agent in some infectious diseases such as chronic
hepatitis B and C. Since the early clinical trials it was documented that the therapeutic use of IFNs could be complicated
by the development of antibodies able to neutralize or to bind to the IFN molecule.
After several years of research it is now widely accepted that the presence of circulating anti-IFN antibodies may affect
the response to IFN.
Here we summarize what is currently know on the clinical significance of antibodies to IFN in IFN-treated viral diseases patients. 相似文献
110.
银川异伊螨新种记述(蜱螨亚纲:犹伊螨科) 总被引:1,自引:0,他引:1
本文记述一新种,即银川异伊螨。标本采自银川市日本埋葬虫体上,文中列表比较了相近种长沟异伊螨和玉溪异伊螨的区别。 相似文献