Allergy against chironomids (non biting midges) in adult atopic patients

Summary The aim of this investigation was to evaluate the prevalence of atopic sensitization to chironomids (CHI) in patients with asthma and/or rhinitis (A/R), and to study concomitant sensitization to CHI and other allergens. Skin prick tests were performed with 3 different CHI extracts as well as with common inhalant allergens in 600 consecutive patients, 495 of which had A/R. Allergen specific IgE antibodies in the sera against CHI, shell fish and cockroaches were analyzed with Magic Lite.59 (12%) of the patients with A/R had a positive skin test with CHI. Positive skin tests with house dust mites and a storage mite were more common in CHI allergic patients than in other atopic patients. Nasal or conjunctival provocation tests, performed on 23 of the patients with positive skin test with CHI, were clearly positive in 7 cases (30%), questionable in 8 (35%) and negative in 8 cases (35%).Magic Lite, performed on sera from 50 of the patients with positive skin test against CHI, was positive with CHI in 39 cases (78%), with crayfish in 33 (66%), shrimp 20 (40%), cockroach 21 (40%) and with crab in 3 cases (6%).It is concluded that sensitization against CHI is common in patients with A/R. The clinical relevance of the positive test results is, however, unknown. Concomitant sensitization with CHI, crustaceans and cockroach is common.     

Specific photoperiodic stimulation of dry matter production in a high-latitude cultivar of Poa pratensis

Vegetative plants of Poa pratensis L. cv. Holt (origin 69°N) raised in short days gave large and significant increases in plant dry weight, plant height and leaf area upon exposure to continuous light, compared with 8-h short days, at essentially identical daily inputs of radiant energy (8-h summer daylight ± low intensity extension). For example, by the fourth harvest (after 26, 34 and 46 days at 21, 15 and 9°C, respectively), the dry weights of plants in long days were 81, 163 and 195% greater than those of the corresponding short-day controls at the respective temperatures. Plant leaf areas in long days were between two and four times as large as control values by the end of the experiment. This was mainly due to increased leaf length caused by long-day stimulation of cell extension and division. However, the photoperiod did not affect the partitioning of assimilates amongst leaves, culms and stolons. Most of these effects could also be brought about by exogenous gibberellin application to plants in short days. However, in contrast to the effect of long days, gibberellin treatment also induced stem internode elongation even in these vegetative plants. Examination by standard growth analysis procedures revealed that the observed increases in relative growth rate were due primarily to increased net assimilation rate followed, several days later, by increases in leaf area ratio when newly-emerged leaves began to constitute a significant proportion of the leaf area. It is concluded that these reactions are of great adaptive significance for growth at the marginal temperatures prevailing at high latitudes.     

Na+, Cl− cotransport in Ehrlich ascites tumor cells activated during volume regulation (regulatory volume increase)

Ehrlich ascites cells were preincubated in hypotonic medium with subsequent restoration of tonicity. After the initial osmotic shrinkage the cells recovered their volume within 5 min with an associated KCl uptake. The volume recovery was inhibited when NO-3 was substituted for Cl-, and when Na+ was replaced by K+, or by choline (at 5 mM external K+). The volume recovery was strongly inhibited by furosemide and bumetanide, but essentially unaffected by DIDS. The net uptake of Cl- was much larger than the value predicted from the conductive Cl- permeability. The undirectional 36Cl flux, which was insensitive to bumetanide under steady-state conditions, was substantially increased during regulatory volume increase, and showed a large bumetanide-sensitive component. During volume recovery the Cl- flux ratio (influx/efflux) for the bumetanide-sensitive component was estimated at 1.85, compatible with a coupled uptake of Na+ and Cl-, or with an uptake via a K+,Na+,2Cl- cotransport system. The latter possibility is unlikely, however, because a net uptake of KCl was found even at low external K+, and because no K+ uptake was found in ouabain-poisoned cells. In the presence of ouabain a bumetanide-sensitive uptake during volume recovery of Na+ and Cl- in nearly equimolar amounts was demonstrated. It is proposed that the primary process during the regulatory volume increase is an activation of an otherwise quiescent, bumetanide-sensitive Na+,Cl- cotransport system with subsequent replacement of Na+ by K+ via the Na+/K+ pump, stimulated by the Na+ influx through the Na+,Cl- cotransport system.     

Role of calcium binding by sarcoplasmic reticulum in the contraction and relaxation of uterine smooth muscle

The binding of calcium by isolated sarcoplasmic reticulum from cow uterus was studied. Sarcoplasmic reticulum was prepared by differential centrifugation. Three fractions were obtained: I, sedimented between 2,500–15,000 x g; II at 40,000 x g; and III, at 150,000 x g. Fraction II was further purified on a sucrose density gradient. All three fractions contained considerable amounts of intrinsic calcium, mostly in fraction I. Calcium binding in the presence of ATP¹ and Mg also was greatest in fraction I, followed by fraction II, with less in fraction III. Without ATP no calcium was taken up. 5 and 10 mM sodium azide partially inhibited calcium binding in fraction I, but not in fraction II, suggesting the presence of some mitochondria or mitochondrial fragments in fraction I. Calcium binding in fraction II was completely inhibited by 3 mM salyrgan; this fraction thus appears to be sarcoplasmic reticulum. ATPase activity was found in all three fractions, highest in fraction II. It is computed that calcium binding in fractions I and II, on the basis of a 50% yield of protein, is sufficient to elicit contraction by supplying calcium to the contractile proteins of the smooth muscle cell and to regulate relaxation and contraction.     

Interaction of Growth Retardants and Temperature in Growth, Flowering, Regeneration, and Auxin Activity of Begonia × cheimantha Everett

Soil application of CCC reduced stem and leaf growth in Begonia plants. This effect was evident with all concentrations tested at 18°C, whereas at 21 and 24°C no growth–retarding effect was observed with 2 × 10^?2 M CCC, and with 5 × 10^?3 M growth was even stimulated. Flowering was promoted by CCC in long day and neur–critical temperature, particularly under low light intensity in the winter. The formation of adventitious buds in leaves of plants grown at 21 and 24°C was stimulated when the plants received 5 × 10^?2 and 2 × 10^?2 M CCC, while 8 7times; 10^?2 M was inhibitory. In plants grown at 18°C bud formation was inhibited by all CCC concentrations. Root formation in the the leaves was usually stimulated by high CCC concentrations, while root elongation was reduced. The level of ether–extractable. acidic auxin (presumably IAA) in the leaves was lowered by CCC treatment of the plants, hut this required higher CCC concentrations at higt than at low temperature. When applied to detached leaves CCC stimulated bud formation at concentrations ranging from 10^?4 to 10^?2 M in leaves planted at 18 and 21°C. At 24°C budding was inhibited by 10^?2 M CCC, the lower concentrations being stimulatory also at this temperature. Root formation and growth were not much affected by CCC treatment of the leaves, but increased with the temperature. Soil application of Phosfon (4 × 10^?4 M) had no effect on growth and flowering, nov did it affect the subsequent regeneration of buds and roots in the leaves. In detached leaves Phosfon stimulated bud formation with au optimum at 10^?6 M. Root formation was stimulated by Phosfon at all temperatures, the optimal concentration being 10^?5 M, whereas root length was conversely affected. Foliar application of B-995 to intact plants and treatment of detached leaves greatly inhibited the formation of buds and had little effect on root formation. B-99D reduced the growth and delayed flowering in the plants.     

Microtubule assembly is required for the formation of the pronuclei,nuclear lamin acquisition,and DNA synthesis during mouse,but not sea urchin,fertillization

Microtubule assembly is required for the formation of the male and female pronuclei during mouse, but not sea urchin, fertilization. In mouse oocytes, 50 μM colcemid prevents the decondensation of the maternal meiotic chromosomes and of the incorporated sperm nucleus during in vitro fertilization. Nuclear lamins do not associate with either of the parental chromatin sets although peripherin, the PI nuclear peripheral antigen, appears on both. DN A synthesis docs not occur in these fertilized, colcemid-arrested oocytes. This effect is limited to the first hours after ovulation, since colcemid added 4–6 hours later no longer prevents pronuclear development, lamin acquisition, or DNA synthesis. Neither microtubule stabilization with 10 μM taxol nor microfilament inhibition with 10 μM cytochalasin D or 2.2 μg/ml lalrunculin A prevent these pronuclear events; these drugs will inhibit the apposition of the pronuclei at the egg center. In sea urchin eggs, colcemid or griseofulvin treatment doe? not result in the same effect and the male pronucleus forms with the attendant accumulation of the nuclear lamins. The differences in the requirement for microtubule assembly during pronucleus formation may be related to the cell cycle: In mice the sperm enters a meiotic cytoplasm, whereas in sea urchin eggs it enters an interphase cytoplasm. Refertilization of mitotic sea urchin eggs was performed to test the possibility that this phenomenon is related to whether the sperm enters a meiotic/mitotic cytoplasm or one at interphase; during refertilization at first mitosis, the incorporated sperm nucleus is unable to decondense and acquire lamins. These results indicate a requirement for microtubule assembly for the progression from meiosis to first interphase during mouse fertilization and suggest that the cytoskeleton is required for changes in nuclear architecture necessary during fertilization and the cell cycle.     

Modulation of the activity of phosphoenolypyruvate carboxylase during potassium-induced swelling of guard-cell protoplasts of Vicia faba L. after light and dark treatments

Phosphoenolpyruvate carboxylase (PEPCase; EC 4.1.1.31) activity was found to be modulated by light and darkness when measured in the presence of K⁺, which had been added to induce swelling of guard-cell protoplasts (GCPs) from Vicia faba L., whereas no modulation was detected in the absence of K⁺ (PEPcase activity remained constant at 1.5±0.15 pmol PEP metabolized · GCP^–1 ·h^–1; subsequently, pmol GCP^–1 ·h^–1 will be used). The activity of PEPCase increased by 100% (from 1.5 to 3 pmol·protoplast^–1·h^–1) in darkness and by 200% (from 1.7 to 5 pmol·protoplast^–1· h^–1) in light and oscillations in activity of these magnitudes were repeated at intervals of 2 min (dark) and 2.5 min (light) for a period of 10 min during K⁺-induced increase in the volume of GCPs. The oscillations were reflected in changes in malate-pool sizes determined in plastids, mitochondria and the supernatant fraction (consisting of the cytosol and the vacuole). Malate probably functioned as a mitochondrial substrate, thus supplying ATP for K⁺ uptake and the swelling of the protoplasts. On the basis of the present paper and previous results (H. Schnabl and B. Michalke 1988, Life Sci. Adv. Plant Physiol. 7, 203–207) involving adenine nucleotidepool sizes in fractionated GCPs, a model is proposed to explain the cause-effect relationship between K⁺, PEPCase, the cytosolic and mitochondrial malate levels and ATP levels during the K⁺-induced increase of GCP volume.Abbreviations GCP dtguard-cell protoplast - PEP phosphoenol-pyruvate - PEPCase PEP carboxylase The authors thank Professor Hermann Schnabl, University of Stuttgart (FRG), for his assistance in applying the graph theory analysis. This work was supported by Deutsche Forschungsgemeinschaft to H.S.