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181.
182.
Vullings H. G. B. Ten Voorde S. E. C. G. Passier P. C. C. M. Diederen J. H. B. Van Der Horst D. J. NÄSSEL D. R. 《Brain Cell Biology》1998,27(12):901-913
The distribution and actions of FMRFamide-related peptides (FaRPs) in the corpora cardiaca of the locust Locusta migratoria were studied. Antisera to FMRFamide and SchistoFLRFamide (PDVDHVFLRFamide) label neuronal processes that impinge on glandular cells in the glandular lobe of the corpora cardiaca known to produce adipokinetic hormones. Electron microscopic immunocytochemistry revealed that these FaRP-containing processes form synaptoid contacts with the glandular cells. Approximately 12% of the axon profiles present in the glandular part of the corpus cardiacum contained SchistoFLRFamide-immunoreactive material. Retrograde tracing of the axons in the nervus corporis cardiaci II with Lucifer yellow revealed 25–30 labelled neuronal cell bodies in each lateral part of the protocerebrum. About five of these in each hemisphere reacted with the SchistoFLRFamide-antiserum. Double-labelling immunocytochemistry showed that the FaRP-containing processes in the glandular lobe of the corpora cardiaca are distinct from neuronal processes, reacting with an antiserum to the neuropeptide locustatachykinin. The effect of the decapeptide SchistoFLRFamide and the tetrapeptide FMRFamide on the release of adipokinetic hormone I (AKH I) from the cells in the glandular part of the corpus cardiacum was studied in vitro. Neither the deca- nor the tetrapeptide had any effect on the spontaneous release of AKH I. Release of AKH I induced by the phosphodiesterase inhibitor IBMX, however, was reduced significantly by both peptides. These results point to an involvement of FaRPs as inhibitory modulators in the regulation of the release of adipokinetic hormone from the glandular cells. 相似文献
183.
Sources and sinks of nitrous oxide (N2O) in deep lakes 总被引:3,自引:1,他引:2
As reported from marine systems, we found that also in15 prealpine lakes N2O concentrations werestrongly correlated with O2 concentrations. Inoxic waters below the mixed surface layer, N2Oconcentrations usually increased with decreasingO2 concentrations. N2O is produced in oxicepilimnia, in oxic hypolimnia and at oxic-anoxicboundaries, either in the water or at the sediment-waterinterface. It is consumed, however, incompletely anoxic layers. Anoxic water layers weretherefore N2O undersaturated. All studied lakeswere sources for atmospheric N2O, including thosewith anoxic, N2O undersaturated hypolimnia.However, compared to agriculture, lakes seem not tocontribute significantly to atmospheric N2Oemissions. 相似文献
184.
The U‐shaped association of body mass index with mortality: Influence of the traits height,intelligence, and education 下载免费PDF全文
185.
Astorga and Williams1 have demonstrated that leucocytes from some patients with rheumatoid arthritis (RA) have an impaired one-way mixed leucocyte reaction2 (MLR) when stimulated with leucocytes from other such patients. No definite explanation of this phenomenon is given. We have investigated other diseases in which auto-immune aetiology is suspected to see whether similar phenomena are associated with them. Here we report our investigations of multiple sclerosis (MS). 相似文献
186.
Mass fragmentographic determination of homovanillic acid in tissues and body fluids using the deuterium labeled species as internal standard 总被引:1,自引:0,他引:1
Mass fragmentographic methods for determination of 4-hydroxy-3-methoxyphenyl acetic acid (HVA) in human cerebrospinal fluid (CSF), urine, blood plasma and mouse brain were developed. After isolation by extraction or by Amberlite XAD-2 chromatography the HVA was converted to the heptafluorobutyryl methyl ester derivative and analyzed using the 2, 2 dideutero-2 (4-hydroxy-3-methoxy-2, 5, 6-trideuterophenyl) acetic acid (HVA-d5) as an internal standard. The values (mean ± coefficient of variation) obtained on repetitive analyses of the same sample were for human CSF 0.42 nmole/ml ± 1.5% (n = 10), human plasma 48 pmole/ml ± 4.5% (n = 15), human urine 20 nmole/ml ± 5.4% (n = 10) and mouse brain 1.2 nmole/g ± 0.6% (n = 12). The results demonstrate that the use of HVA-d5 as an internal standard provides high precision and the necessary sensitivity for the mass fragmentographic determination of HVA in small amount of tissue and body fluids. 相似文献
187.
Vector competence of field populations of the mosquito species Aedes japonicus japonicus and Culex pipiens from Switzerland for two West Nile virus strains 下载免费PDF全文
188.
Behavioral and Physiological Thermoregulation of Crocodilians 总被引:1,自引:0,他引:1
Crocodilians, like other reptiles, regulate their body temperaturesby a combination of behavioral and physiological mechanisms.Behaviorally, they seek warm surface water or bask when cooland avoid overheating by the evaporation of water from theirdorsum, evaporation of water by gaping or by retreating to deep,cool water. Physiologically, crocodilians increase cutaneousthermal conductance by increasing blood flow to the skin (andsubdermal musculature) during warming. This hastens the warmingprocess. Cutaneous blood flow is reduced during general coolingand locally if the body temperature exceeds skin temperature.This enables crocodilians to increase body temperature significantlywhile basking in cool shallow water. Large crocodilians appearto be able to alter their rates of heat exchange to a largerextent than small ones and they can do so with less cardiovascularinvolvement. Large crocodilians, with their lower surface/volumeratio, are capable of producing sufficient metabolic heat toelevate their body temperature above water temperature. 相似文献
189.
YAC is a Moloney-virus-induced lymphoma of strain A/Sn origin that is highly sensitive to natural killing (NK) in vitro and NK-mediated hybrid resistance in vivo. Previous studies have shown that hybrid resistance is under polygenic control that includes both H-2-linked and non-H-2-linked factors. For further analysis on the genetics and immunology of hybrid resistance, we are at present developing congenic resistant lines on an A/Sn strain background. Following an outcross to a strain that conveys strong hybrid resistance on the F1 offspring, the mice are challenged with small viable inocula of YAC. Survivors are backcrossed to A/Sn. This is followed by repeated YAC challenge and backcrossing. We now report the successful establishment of a first resistant strain, designated A.LRA. It is relatively resistant to small inocula of YAC cells due to a single, non-H-2-linked dominant gene introduced from the C57L strain. 相似文献
190.
Onset of photosynthesis in spring speeds up monoterpene synthesis and leads to emission bursts 下载免费PDF全文
J. Aalto A. Porcar‐Castell J. Atherton P. Kolari T. Pohja P. Hari E. Nikinmaa T. PetÄJÄ J. Bäck 《Plant, cell & environment》2015,38(11):2299-2312
Emissions of biogenic volatile organic compounds (BVOC) by boreal evergreen trees have strong seasonality, with low emission rates during photosynthetically inactive winter and increasing rates towards summer. Yet, the regulation of this seasonality remains unclear. We measured in situ monoterpene emissions from Scots pine shoots during several spring periods and analysed their dynamics in connection with the spring recovery of photosynthesis. We found high emission peaks caused by enhanced monoterpene synthesis consistently during every spring period (monoterpene emission bursts, MEB). The timing of the MEBs varied relatively little between the spring periods. The timing of the MEBs showed good agreement with the photosynthetic spring recovery, which was studied with simultaneous measurements of chlorophyll fluorescence, CO2 exchange and a simple, temperature history‐based proxy for state of photosynthetic acclimation, S. We conclude that the MEBs were related to the early stages of photosynthetic recovery, when the efficiency of photosynthetic carbon reactions is still low whereas the light harvesting machinery actively absorbs light energy. This suggests that the MEBs may serve a protective functional role for the foliage during this critical transitory state and that these high emission peaks may contribute to atmospheric chemistry in the boreal forest in springtime. 相似文献