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161.
The developing porcine fetus offers an excellent opportunity for the study of lymphocyte development. Studies on B cell, alphabeta T cells and gammadelta T cells in the last decade have expanded our knowledge of lymphocyte development in pigs. These studies have revealed several interesting differences between swine, mice and humans. For example, porcine peripheral lymphocytes include CD4+CD8+ alphabeta T cells and an abundance of gammadelta T cells that may even prevail over the alphabeta population. There are numerous CD2- gammadelta T cells in the blood and a large number of CD8alphaalpha-bearing cells that include NK cells, conventional gammadelta and alphabeta T cells. All porcine B lymphocytes are CD25(lo) and sIgM+ B cells may differ in the expression of CD2 antigen. Unlike mice, porcine B cells appear approximately 2 weeks before T cells and progenitors undergo VDJH rearrangement at 20th day of gestation (DG20) in the yolk sac and DG30 in the fetal liver before consummating high level lymphogenesis in the bone marrow after DG45. Early B cells show an unexpectedly high proportion of in-frame rearrangements, undergo switch recombination in thymus on DG60 and use N-region insertion from the time of the earliest VDJ rearrangement. The genomic repertoire of VH, DH and JH genes is small compared to mice and humans and swine appear to depend on junctional diversity for the majority of their repertoire. The limited VH repertoire of swine contrasts sharply with the porcine TCRbeta repertoire, which is extensive, extraordinarily conserved and nearly identical to that in humans. Therefore, swine present an example of two highly related receptor systems that have diverged in the same species.  相似文献   
162.
Evaporative cooling of rose plants ‘Baccara’ and ‘Marimba’ by “fan and pad” resulted in a substantial increase in shoot water potential, a decrease in leaf diffusive resistance, and an increase in CO2 fixation. The mid-day increase in the leaf diffusive resistance was not accompanied by a decrease in the CO2 uptake. This phenomenon is attributed to the existence of continuous air flow through the plant canopy. Evaporative cooling also increased leaf area and the fresh weight and dry matter content of flower buds and stems.  相似文献   
163.
Difficulty in recognition of some diaphragmatic hernias in dogs have stimulated the authors to develop a diagnostic method consisting of selective angiography of the cranial mesenteric and celiac arteries. The basis for the experimen was that each herniated visceral organ is usually displaced with its vessels. The experiment was carried out on 14 mongrel dogs. Four dogs served as controls. Different kinds of diaphragmatic hernias were surgically created in 10 dogs. Survey abdominal radiographs, gastrointestinal tract contrast studies and selective abdominal angiography were performed 14 days later. In angiograms of dogs with omental diaphragmatic hernias, displacement of branches of the left gastroepiploic artery into the thorax was seen. In angiograms of dogs with hepatic diaphragmatic hernias, branches of the common hepatic artery were seen to enter the thorax. In dogs with herniated small intestine, the jejunal branches of the cranial mesenteric artery were seen entering the thorax. Potential possibilities of selective abdominal angiography for diagnosis of diaphragmatic hernias are discussed.  相似文献   
164.
The objective of the study was to demonstrate the presence of estrogen receptor alpha (ERalpha) and beta (ERbeta) protein and corresponding mRNA in porcine ovarian follicles and corpora lutea obtained on day 10, 18, 32, 50, 71 and 90 post coitum (p.c.) using immunohistochemistry, Western blot, and RT-PCR analysis. Immunohistochemistry showed that ERalpha protein was located in the granulosa cells of ovarian follicles and the strongest immunoreaction was observed on days 32 and 50 p.c. The ERbeta protein was found mainly in theca cells of follicles as well as in luteal cells. The most intense immunoreaction was observed on day 18 p.c. within theca cells, while in the corpus luteum (CL) the intensity of ERbeta staining gradually increased and remained elevated at mid and late pregnancy. In CL by day 50 p.c. immunoreaction for ERbeta was present only in small luteal cells, but starting from day 71 to 90 p.c. it was observed in both small and large luteal cells. Western blot analysis was performed and validated data obtained from immunohistochemistry. RT-PCR results indicated that ERalpha mRNA was expressed only in ovarian follicles of the pregnant swine, while that of ERbeta in both follicles and CL. The results suggest an autocrine/paracrine role of estrogens acting via both ERalpha and ERbeta in the regulation of the ovarian function during pregnancy and for the process of successful reproduction.  相似文献   
165.
166.
The varied bioavailability and different effects of organic forms of copper on the immune system of poultry have prompted the search for new feed additives based on copper compounds containing modified chelate complexes. The aim of the study was to determine the effect of inorganic and organic forms of copper on selected parameters of the cellular and humoral immune response in broiler chickens by determining the percentages of CD3+CD4+, CD3+CD8+ and CD25+ lymphocytes, cells with MHC Class II expression, and BU‐1+ cells, as well as the concentrations of SOD, IL‐2, IL‐10 and TNF‐α in the peripheral blood. The experiments were conducted using 500 one‐day‐old Ross 308 roosters divided into five groups. Cu was added in inorganic form (CuSO4), in inorganic form with the addition of phytase (CuSO4 + F), in organic form in combination with glycine (Cu‐Gly) and in organic form in combination with glycine and a phytase supplement (Cu‐Gly+F). The results of the study indicate an increase in the percentage of CD3+CD4+ and CD3+CD8+ T lymphocytes, CD25+ T cells, and cells expressing MHC class II molecules, and in the concentration of ceruloplasmin, activity of superoxide dismutase and the concentration of IL‐2 in the groups that received copper, particularly copper‐glycine chelates. Based on the study, we can conclude that supplementation of poultry feed with copper chelates activates mainly the Th1 cellular immune response and the response of peripheral blood T lymphocytes. Furthermore, it promotes secretion of cytokines, which are involved in potentiation and regulation of the immune response in birds.  相似文献   
167.
After exposure in the field and laboratory soil block culture testing, the void content of wood–plastic composite (WPC) decking boards was compared to unexposed samples. A void volume analysis was conducted based on calculations of sample density and from micro-computed tomography (microCT) data. It was found that reference WPC contains voids of different sizes from the micrometer range up to several cubic millimeters. Large voids were unevenly distributed within the composite sample. Void size and volume increased after conditioning the WPC in water at 70°C. Depending on the effect of exposure conditions, fungal decay during laboratory soil block testing increased the size and volume of voids. For laboratory samples, the calculated void volume was much higher compared to microCT-detected voids because of the limited resolution of the instrument on relatively large samples with many nano- and microvoids present in the material. In both laboratory and field samples, the creation of the voids resulted in a significant decrease in composite density. Decay damage observed as an increase in the size and volume of voids was particularly severe for boards exposed in the field. The calculated void volume in such samples was in reasonable agreement with voids detected by microCT.  相似文献   
168.

? Key message

Natural regeneration of P. abies (L.) H. Karst. may reach high densities in lower mountain elevations. The highest densities were found in sites with moderate light availability, with low pH, and not near the riverbank. However, age-height classes differed in the predicted magnitude of response, but were consistent in response directions. Mosses and understory species typical of coniferous forests were positively correlated with regeneration density.

? Context

Norway spruce Picea abies (L.) H. Karst. in Central Europe is at risk under climate change scenarios, particularly in mountain regions. Little is known about the impact of environmental factors on the natural regeneration of P. abies in low-elevation mountain forests.

? Aims

We aimed to assess impacts of distance from the riverbank, soil pH, and light availability on natural P. abies regeneration. We hypothesized that (1) natural P. abies regeneration would depend on light availability and soil pH and (2) there are understory plant species which may indicate the microsites suitable for natural regeneration of P. abies.

? Methods

The study was conducted in the Sto?owe Mountains National Park (SW Poland, 600–800 m a.s.l.). We established 160 study plots (25 m2) for natural regeneration, light availability, soil pH, and understory vegetation assessment.

? Results

The highest densities of natural regeneration of P. abies were observed in sites with moderate light availability (0.1–0.2 of open sky) and low pH (3.5–4.5), and located relatively far from the riverbank. Cover of 22 understory plant species were correlated with natural P. abies regeneration densities, mostly positively.

? Conclusion

Different stages of natural regeneration of P. abies revealed different regeneration niches. Most understory plant species (bryophytes and herbs typical of coniferous forests) do not compete with natural regeneration of P. abies.
  相似文献   
169.
The summary deals with the anti-convulsant and antilethal effects of a new benzodiazepine receptor partial agonist, imidazenil, in DFP intoxication. It has been demonstrated that imidazenil (2–5 mg kg−1) significantly decreases convulsion intensity, rapidly inhibits seizure patterns in brain bioelectrical activity and significantly increases the anti-lethal efficacy of atropine plus obidoxime therapy. These effects are comparable to diazepam at 5 mg kg−1. However, diazepam exhibits myorelaxant activity at therapeutic doses, which are only observed at 5–10 times the therapeutic doses of imidazenil.  相似文献   
170.
A three-year test of growth performance andoffspring survival from top-crossing of commoncarp hybrids in low altitude (350 m above thesea level, middle European climate) and in highaltitude (750 m above the sea level, middleEuropean climate) was terminated by assessmentof slaughtering value of edible parts in therespective strains. A recently establishedHungarian synthetic mirror carp strain (HSM)was chosen for testing as maternal strain. TheHSM, as well as wild Amur carp (AC), Ropshacarp (ROP) and Tata carp (TAT) were used aspaternal strains.The evidential strain*altitude interactioneffect was demonstrated as significant forweight of fish (0.0005), fillet without skin(0.0001), index of highbackedness (0.005),index of head length (0.0404),Fulton's coefficient (0.0497),index of widebackedness (0.0315) andgonadosomatic index (0.0082). The interactioneffect was demonstrated as insignificantbetween altitude*sex and betweenstrain*sex.The comparative test of analysis of variance(ANOVA) revealed significantly (P < 0.05)higher weight of fish after killing on lowaltitude (1611.6 g) than on high altitude(1090.3 g), but processed body yield andpercentage of fillet without skin was notsignificantly different (64.0 and 34.2 for lowaltitude, 64.2 and 33.4 for high altitude). Thepercentage of processed body weight andpercentage of fillet without skin in analysisboth altitudes were significantly better infemales (65.5 and 34.6%) than in males (62.5and 33.00%), respectively. The highestsignificant differences in weight of fish afterkilling were found between HSM (890.8 g) andHSM × AC (1283.3 g) in high altitude. In lowaltitude, it was between HSM (1527.2 g) andHSM × AC (1706.9 g) and HSM × ROP (1693.0 g).  相似文献   
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