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121.
alpha 1-Proteinase inhibitors (alpha 1-PIs) are members of the serpin
superfamily of proteinase inhibitors, and are important in the maintenance
of homeostasis in a wide variety of animal taxa. Previous studies have
shown that in mice (genus Mus), evolution of alpha 1-PIs is characterized
by gene amplification, region-specific concerted evolution, and rapid
accumulation of amino acid substitutions. The latter occurs primarily in
the reactive center, which is the region of the alpha 1-PI molecule that
determines the inhibitor's specificity for target proteinases. The P1
residue within the reactive center, which is methionine in so-called
orthodox alpha 1-PIs and an amino acid other than methionine in unorthodox
alpha 1-PIs, is a primary determinant of inhibitor specificity. In the
present study, we find that the expression of mRNAs encoding unorthodox
alpha 1-PIs is polymorphic within Mus species, i.e., among individuals or
inbred strains. This is in striking contrast to mRNAs that encode orthodox
alpha 1-PIs, whose concentrations are relatively invariant. The
intraspecies variations in mRNA expression represent polymorphisms in the
structure of the alpha 1- PI gene family. The results, taken together with
previously described aspects of alpha 1-PI evolution, indicate that the
dissimilar levels of polymorphism exhibited by orthodox and unorthodox
alpha 1-PIs, which likely have distinct physiological functions, may
reflect different levels of selective constraint. The significance of this
finding to the evolution of gene families is discussed.
相似文献
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124.
Faycal El Majdoub Moataz Elawady Tobias Blau Christian Bührle Mauritius Hoevels Matthias Runge Rolf-Peter Müller Martina Deckert Volker Sturm Mohammad Maarouf 《PloS one》2012,7(11)
Background
We evaluated the long-term outcome in patients harboring intracranial ependymomas treated with interstitial brachytherapy (IBT).Methods
Twenty-one patients (M/F = 9/12; median age: 29 years; range: 8–70 years), diagnosed with intracranial ependymoma (1 WHO I, 11 WHO II, 9 WHO III) were treated with IBT using stereotactically implanted 125Iodine seeds between 1987 and 2010, either primarily, as adjuvant therapy following incomplete resection, or as salvage treatment upon tumor recurrence. Sixteen of 21 patients underwent microsurgical resection prior to IBT; in 5 patients, IBT was performed primarily after stereotactic biopsy for histological diagnosis. The cumulative tumor surface dose ranged from 50–65 Gy treating a median tumor volume of 3.6 ml (range, 0.3–11.6 ml). A median follow-up period of 105.3 months (range, 12.7–286.2 months) was evaluated.Results
Actuarial 2-, 5- and 10-years overall- and disease-specific survival rates after IBT were each 90% and 100% at all times for ependymomas WHO I/II, for anaplastic ependymomas WHO III 100%, 100%, 70% and 100%, 100%, 86%, respectively. The neurological status of seven patients improved, while there was no change in 12 and deterioration in 2 patients, respectively. Follow-up MR images disclosed a complete tumor remission in 3, a partial remission in 12 and a stable disease in 6 patients. Treatment-associated morbidity only occurred in a single patient.Conclusions
This study shows that stereotactic IBT for intracranial ependymomas is safe and can provide a high degree of local tumor control. Due to the low rate of side effects, IBT may evolve into an attractive alternative to microsurgery in ependymomas located in eloquent areas or as a salvage treatment. 相似文献125.
Jeffrey A. Runge 《Journal of experimental marine biology and ecology》1984,74(1):53-66
When acclimated to a continuous, superabundant food supply and constant temperature, Calanus pacificus Brodsky females produce eggs at a weight-specific rate ranging from 0.13 · day?1 at 8°C to 0.21 · day?1 at 15°C. Maximum weight-specific egg production rates do not change with seasonal changes in female body size. The relationship between egg production rate and food concentration is hyperbolic, with threshold and critical concentrations that are high relative to other species for which data are available. Food concentration and temperature influence spawning frequency (i.e., the time required for oocytes to mature) much more than the number of eggs in a single spawning event (i.e., clutch size). Clutch size is significantly related to female body size. 相似文献
126.
S W Runge 《BioTechniques》1992,12(5):630-631
Current methods of analyzing fusion proteins from lambda gt11 clones involve either subcloning of the insert DNA into a plasmid expression vector or production of lambda gt11 lysogens that are subsequently induced. Both of these methods can be quite time-consuming. The present communication describes a novel strategy for induction of the fusion protein that is both simple and rapid. Liquid cultures of E. coli Y1090R- infected with the lambda gt11 clone were induced directly to produce the fusion protein. Following the preparation of a crude bacterial cell lysate, fusion products were subjected to Western blot analysis. 相似文献
127.
Cyclic AMP phosphodiesterase was measured in liver homogenates and microdissected periportal and perivenous liver tissue from rats in different dietary states under different conditions of substrate saturation and effector stimulation. A radiochemical microtest, more sensitive by 2-3 orders of magnitude than the usual assay, was established for the determination of the activity in liver samples corresponding to 200-800 ng dry weight. At saturating cyclic AMP concentrations (46 microM) phosphodiesterase was homogeneously distributed within the liver acinus of fed rats. Starvation for 48 h led to a decrease in the overall activity and to a heterogenous distribution with slightly higher activities in the perivenous zone. At physiological cyclic AMP concentrations (1.8 microM) phosphodiesterase showed a flat zonal gradient in livers of fed rats with higher levels in the periportal zone; after 48 h starvation it was homogeneously distributed. In the presence of cyclic GMP (2 microM) the basal activity at physiological substrate concentrations was stimulated to a greater extent in the perivenous zone. This led to a homogeneous activity distribution in the fed state and to a heterogenous pattern with a slight perivenous maximum in the fasted state. Thus there was no or only a small zonal heterogeneity of signal transmitting enzymes such as cyclic AMP phosphodiesterase and glucagon-stimulated adenylate cyclase (Zierz and Jungermann 1984). This similar signal transducing capacity in the periportal and the perivenous area will contribute to maintain the zonation of signal input due to the hormone concentration gradients across the liver acinus. 相似文献
128.
129.
Monoclonal antibodies specific for a rat tumor-associated protein cross-react with a similar protein present in the cytosol of the rat fetus. The oncofetal protein exists as two species of approximate molecular weight 50 and 55 kDa which promote the transport of RNA from isolated nuclei. During rat fetal development, the protein first increases in concentration from approximately 12 to 16 days gestation and then drops to non-detectable levels perinatally. 相似文献
130.
F. Runge 《Plant Ecology》1963,11(4):237-240
Summary In a Gentiano-Koelerietum of the Beckumer Berge (Westfalen) a permanent quadrat of 3 sq. metres was constructed. Sample plot analyses (see table), noticed during 5 years (1957–1961), gave the following results:Many species, especially the perennials, nearly do not fluctuate in quantity during many years. Some plants continuously decrease or increase in number. Other species, especially the annuals, fluctuate irregularly in abundance. These fluctuations depend on fluctuations of climatic factors. 相似文献