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1.
Summary The distribution of monoamines in the pharynx and oesophagus of the rhesus monkey (Macacus rhesus) and the cat (Felis domestica) was investigated by means of fluorescence microscopical and chemical methods. Fluorimetric determinations reveal the presence of varying amounts of noradrenaline in the pharynx and oesophagus of the rhesus monkey. The lowest amount (0.05 (g/g) was found in the lower part of the oesophagus, the so-called sphincter-segment. The middle and upper part of the oesophagus contain medium amounts of noradrenaline (0.06–0.09 g) whereas the highest concentration was detected in the pharynx (0.14 (g/g). Neither dopamine nor adrenaline occurred in the tissue pieces analyzed. Fluorescence microscopically noradrenaline was found to be located in varicose intramural nerve fibre plexus which innervate mucous glands and blood vessels in the pharynx of both species. In the rhesus monkey, the lamina muscularis mucosae of all parts of the oesophagus is supplied by a well developed noradrenergic ground-plexus. Preterminal and terminal varicose nerve fibres are distributed in myenteric and submucous ganglia of the oesophagus; the number of such ganglia decreases towards the lower segment. The density of the adrenergic innervation is higher in myenteric when compared to submucous ganglia. The arrangement of the intraganglionic terminals suggests that both axosomatic and axodendritic contacts occur in Auerbach's ganglia whereas axodendritic contacts seem to predominate in Meissner's ganglia. Myenteric ganglia situated close to the submucosa as well as true submucous ganglia may be occasionally seen to be traversed by faintly fluorescent non-varicosed fibres which do not establish any synaptic contacts. The fluorescence intensity of intraganglionic varicosities varies considerably; accordingly the transmitter content of individual varicosities seems to be very variable. The adrenergic innervation of the lamina muscularis is restricted to single contorted fibres being sparsely distributed throughout the longitudinal smooth muscle layer. The circularly arranged smooth musculature of the sphincter-segment lacks an adrenergic nerve supply. The vagus nerve carries sympathetic adrenergic fibres to the lower oesophagus and the cardia. Species differences between the innervation pattern in rhesus monkeys and cats are outlined: No adrenergically innervated ganglia occur in the submucosa of the cat. However, part of the myenteric ganglia in cats exhibit an adrenergic innervation pattern similar to that seen in submucous ganglia of the rhesus monkey. They might therefore be regarded as morphologically equivalent to the plexus submucosus which is, however, present in the whole gut. The density of the noradrenergic ground-plexus in the muscularis mucosae of the cat's oesophagus is less than that of the corresponding plexus in rhesus monkeys.The influence of noradrenaline upon the smooth musculature and the neurons from myenteric as well as submucous ganglia is discussed. From the point of view of the adrenergic innervation there is no structure corresponding to the sphincterlike lower oesophageal segment.Supported by the Deutsche Forschungsgemeinschaft and the Joachim-Jungius-Gesellschaft zur Förderung der Wissenschaften, Hamburg.  相似文献   

2.
Ceratomyxa seriolae n. sp. and C. buri n. sp. (Myxozoa: Myxosporea) were found in the gall-bladder of cultured yellowtail Seriola quinqueradiata Temminck & Schlegel (Carangidae) in Japan. Mature spores of C. seriolae n. sp. were elongate and 6.5 (6.0-7.5) m long and 33.7 (28.0-41.5) m thick. Disporous plasmodia of C. seriolae n. sp., 40-100 m in size, were amoeboid to spherical. C. buri n. sp. were elliptical with a flattened posterior end, 6.5 (5.5-7.5) m long and 14.3 (11.0-16.5) m thick. Spherical plasmodia of C. buri n. sp., 15-20 m in diameter, were disporous. In periodical sampling of yellowtail bile from August, 1999 to February, 2000, the two new species of Ceratomyxa, as well as Myxobolus spirosulcatus Maeno, Sorimachi, Ogawa & Kearn 1995, first appeared in October, and the prevalences were very variable (20-100%) during the study period.  相似文献   

3.
Four new species of Isospora are described from Australian geckoes. Isospora gehyrae n. sp. from Gehyra cf. variegata in South Australia have 18.5-22.5×17.5–20.0 m oöcysts with 10.0-12.5×7.5-9.0 m sporocysts; endogenous stages develop in the host cell cytoplasm. Of the two species found in Heteronotia binoei from northern Queensland, Isospora cytoheteronotis n. sp., with oöcysts of 20.0-26.0×17.5-25.0 m and sporocysts of 10.0-13.5×7.5-11.5 m, undergoes endogenous development in its host cell cytoplasm, whereas I. nucleoheteronotis n. sp., with oöcysts of 17.5-22.5×17.5-21.5 m and sporocysts of 9.0-12.5×6.5-10.0 m, develops in the host cell nucleus. I. oedurae n. sp. from Oedura rhombifer in northern Queensland has oöcysts of 22.5-25.0×22.5-24.0 m and sporocysts of 12.5-14.0×7.5-11.5 m, and undergoes endogenous development in its host cell nuclei.  相似文献   

4.
Single-chain Fv molecules in monovalent (sFv) and divalent [(sFv')2] forms exhibit highly specific tumor targeting in mice as a result of their small size and rapid systemic clearance. As a consequence, there is a rapid reversal of the sFv blood/tumor gradient, resulting in diminished retention of sFv species in tumors. In this report we investigate two distinct strategies, dose escalation and repetitive intravenous (i.v.) dosing, aiming to increase the absolute selective retention of radiolabeled anti-c-erbB-2125I-741F8 (sFv')2 in c-erbB-2-overexpressing SK-OV-3 tumors in mice with severe combined immunodeficiency (SCID). A doseescalation strategy was applied to single i.v. injections of125I-741F8 (sFv')2. Doses from 50 g to 1000 g were administered without a significant decrease in tumor targeting or specificity. High doses resulted in large increases in the absolute retention of125I-741F8 (sFv')2. For example, raising the administered dose from 50 g to 1000 g increased the tumor retention 24 h after injection from 0.46 g/g to 9.5 g/g, and resulted in a net increase of greater than 9 /g. Over the same dose range, the liver retention rose from 0.06 g/g to 1 g/g, and resulted in a net increase of less than 1 g/g. The retention of 9.5 g/g in tumor 24 h fllowing the 1000-g dose of (sFv')2 was comparable to that seen 24 h after a 50-g dose of125I-741F8 IgG, indicating that the use of large doses of (sFv')2 may partially offset their rapid clearance. When two doses were administered by i.v. injection 24 h apart, the specificity of delivery to tumor observed after the first dose was maintained following the second injection. Tumor retention of125I-741F8 (sFv')2 was 0.32 g/g at 24 h and 0.22 g/g at 48 h following a single injection of 20 g/g, while 0.04 g/ml and 0.03 g/ml were retained in blood at the same assay times. After a second 20-g injection at the 24-h assay time, tumor retention increased to 0.49 g/g, and blood retention was 0.06 g/ml, at the 48-h point. These results suggest that multiple high-dose administrations of radiolabeled 741F8 (sFv')2 may lead to the selective tumor localization of therapeutic radiation doses.Supported by National Cancer Institute (NCI) National Cooperative Drug Discovery Group grant U01 CA51880, CA06927, an appropriation from the Commonwealth of Pennsylvania, and the Bernard A. and Rebecca S. Bernard Foundation  相似文献   

5.
Summary Vicia faba callus line (VFS 1), isolated from expiants of immature embryo, grew satisfactorily onMurashige andSkoog complete medium with 1.38 M 2,4-D, or with 0.92 M 2,4-D to which 1.0 M kinetin was added. It also grew well on the B 5 modified medium containing 2.3 M 2,4-D and 25.0 M kinetin. On the last of these media the cultures grew more uniformly and without necrosis. They also showed diminishing variation in polyploidy in favour of diploids and corresponding aneuploids (hypodiploids).After being cultured for nearly three years on MS containing 1.38 M 2,4-D, 8–33% of cultures of VFS 1 were able to regenerate roots when transferred to either MS half strength with 5.37 M NAA, or to a medium without 2,4-D, or else to media with the addition of kinetin only (in various concentrations).  相似文献   

6.
    
A structure-activity study was carried out to determine the important groups of coumarin derivatives in inhibiting the oxidoreductase activity of the camel lens-crystallin. Coumarin, 4-hydroxycoumarin, 7-hydroxy-4-methylcoumarin, dicoumarol, and warfarin were screened for their inhibitory effect on-crystallin activity. The sequence of potency for the inhibitors was dicoumarol > 4-hydroxycoumarin > warfarin coumarin. 7-Hydroxy-4-methylcoumarin was ineffective as an inhibitor. Only dicoumarol, 4-hydroxycoumarin, and warfarin were found to inhibit the oxidoreductase activity in micromolar ranges. All tested inhibitors seem to act in reversible and time-independent manner. Concentration causing 50% inhibition of the enzyme activity (IC 50 value) was 34M for dicoumarol, 76M for 4-hydroxycoumarin, and approximately 515M for warfarin, while 1 mM coumarin showed less than 10% inhibition. Kinetic analysis revealed inhibition of camel lens-crystallin by coumarin derivatives to occur in a competitive manner with respect to dichlorophenolindophenol (DCIP) as an electron acceptor and uncompetitive manner with respect to NADPH as an electron donor. TheK i values were found to be 16M for dicoumarol, 40M for 4-hydroxycoumarin, and 220M for warfarin. The structure-activity relationship of coumarin derivatives indicates that the phenolic hydroxyl group at the C-4 position in the coumarin skeleton is important for the maximal inhibition.  相似文献   

7.
Summary The innervation of the major arteries and heart of the toad (Bufo marinus) was examined by use of glyoxylic acid-induced catecholamine fluorescence and peptide immunohistochemistry. All arteries possessed a moderate to dense plexus of adrenergic axons, which also showed neuropeptide Y-like immunoreactivity (NPY-LI). Some adrenergic axons in the intracardiac vagal trunks showed NPY-LI, but the varicose adrenergic axons innervating the cardiac muscle of the atria and ventricle, and the coronary blood vessels did not display NPY-LI. About half of the nerve cell bodies in the anterior sympathetic chain ganglia with dopamine--hydroxylase-LI (DBH-LI) also contained NPY-LI. The nerve cell bodies with DBH-LI alone were generally larger (median diameter 30 m) than those with both DBH-LI and NPY-LI (median diameter 20 m). Some cell bodies showing DBH-LI alone were surrounded by boutons with NPY-LI but not DBH-LI. Axons that displayed simultaneously both substance P-LI (SP-LI) and calcitonin gene-related peptide-LI (CGRP-LI) also formed a plexus around all arteries studied, being particularly dense around the mesenteric and pulmonary arteries. These axons are most likely sensory since SP-LI was reduced by capsaicin treatment, and nerve cell bodies with both SP-LI and CGRP-LI were found in dorsal root ganglia and the vagal ganglion. A dense plexus of axons showing somatostatin-LI was located around the pulmonary artery and its main intrapulmonary branches. A few nerves with vasoactive intestinal polypeptide-LI were found around the dorsal aorta and pulmonary artery. No perivascular nerves with enkephalin-LI were observed. Reversed-phase, high-pressure liquid chromatography of acid extracts of the large arteries showed that the major peaks of NPY-LI and SP-LI coeluted with porcine NPY (1–36) and synthetic SP (1–11), respectively. Thus, the location and structure of these peptides in perivascular nerves has been highly conserved during vertebrate evolution.  相似文献   

8.
Lipid peroxidation in vitro homogenates of brain was examined as sequela of lead toxicity. The levels of malondialdehyde (MDA) in homogenates of rat brain (1 ml, 5% w/v) treated with lead (50 g) alone or in combination with ascorbic acid (100 g), alphatocopherol (100 g) or hydroquinone (100 g) were evaluated. The levels of MDA were consistently evoked by lead in a dose-related manner. The toxicity of lead was further advanced by the action of the pro-oxidant drug ascorbic acid on the brain. However, the anti-oxidant drugs alphatocopherol and hydroquinone decreased the toxic effect of lead on the brain. These results clearly show that the enhanced lipid peroxidation may provide a basis of lead-induced neurotoxicity.  相似文献   

9.
Uptake kinetics of nitrogen derived from sewage–seawater mixtures (2.5–20% v/v effluent) were determined in the laboratory for Ulva rigida (Chlorophyceae) native from Bahía Nueva (Golfo Nuevo, Patagonia, Argentine). In terms of nitrogen concentration, experimental enrichment levels varied between 53.7 and 362.3M of ammonium and between 0.77 and 6.21M of nitrate+nitrite. Uptake rates were fitted to the Michaelis–Menten equation, with the following kinetic parameters: ammonium: Vmax = 591.2molg–1h–1, K s=262.3M, nitrate+nitrite: V max=12.9molg–1h–1, K s=3.5M). Both nutrients were taken up simultaneously, but ammonium incorporation was faster in all cases. The results show a high capability of Ulva rigida to remove sewage-derived nitrogen from culture media. In the field, most of the nitrogen provided by the effluent would be tied up in algal biomass, supporting low nitrogen levels found at a short distance away from the source.  相似文献   

10.
Total mercury was measured in different compartments of Lake Xolotlán's (Managua) ecosystemviz., sediments, water, fish and men. Sediments from 18 localities at 5 depths inside the sediment (5, 10, 15, 20 and 25 cm) contained an average concentration of 0.62 g Hg.g–1±0.46 at the surface, with extreme values of 0.16 and 1.8 g.g–1. The highest concentration was observed at 25 cm depth in front of the chlor-alkaly factory (ELPESA). This maximum is associated with the period of highest production of this factory. The highest mercury concentrations in water were also measured close to the discharge of ELPESA,viz. 787 g.Hg–1 in January and 506 g.g–1 in April. The mean mercury concentrations measured in the muscles of the most consumed fish were 0.63 g.g–1±0.22 (extreme values 0.22 and 1.45) inCichlasoma managuense, and 0.07 g.g–1±0.14 (extreme values 0.004 and 0.63) inC. citrinellum. The concentration in the liver was 0.79 g.g–1±1.29 inC. managuense and 0.62 g.g–1±0.44 inC. citrinellum. Human hairs (n=98) of fishermen and their families contained 5.03 g.g–1±6.2 (extreme values 0.02 and 38.22). The mean concentration measured in men was 6.22 g.g–1±6.34 (n=58), and in women 3.39 g.g–1±5.7 (n=40). The average mercury concentration of hairs of workers of ELPESA was 91.24 g.g–1±156.9 (extreme values 0.46 and 724.53; n=32). We conclude that total mercury levels in the various ecosystem compartments are very high and mercury contamination in the lake may be considered as dangerous for human health.  相似文献   

11.
Oocysts of Isospora ernsti n. sp. and Isospora blagburni n. sp. are described from the black-capped bulbul Pycnonotus xanthopygos from Lincoln Park Zoo, Chicago, Illinois. The bird came from southwestern Africa seven years earlier. I. ernsti oocysts are ellipsoidal to bluntly ovoid, 28–38 × 23–31m (mean 34 × 28 m) and have a single-layered oocyst wall. Micropyle, oocyst residuum and polar granules are absent. Sporocysts are elongate ovoid, 24–30 × 11–16 m (mean 27×13 m). Stieda and substiedal bodies and sporocyst residuum are present. I. blagburni oocysts are spherical to subspherical. 21–28 × 19–26 m (mean 25 × 23 m) and have a single oocyst wall. Sporocysts are ovoid and 17–23 × 10–13 m (mean 20 × 12 m). Stieda and substiedal bodies and sporocyst residuum are present.  相似文献   

12.
Feeding in the rotifer Brachionus calyciflorus   总被引:7,自引:0,他引:7  
Summary The laboratory feeding behavior of Brachionus calyciflorus varies depending upon the type of food cell available in suspension. When feeding on the yeast Rhodotorula glutinis, rotifers show a continuous increase in ingestion with increased cell density between 0.01 and 1000 g dry weight ml-1. Effective clearance rates drop from ca. 50 l animal-1 h-1 to less than 0.5 l animal-1 h-1 over this food density range. When feeding on Englena gracilis, B. calyciflorus ingestion rates are constant between 1.0 and 100 g ml-1 of available food, averaging close to 25 ng animal-1 h-1. The decrease in clearance rate is more striking than with R. glutinis, dropping from 45 l animal-1 h-1 at 0.1 g ml-1 to 0.13 l animal-1 h-1 at 100 g ml-1. Differences between the patterns obtained with the two food types indicate fundamental dissimilarities in the feeding behavior of this rotifer species when presented with these different foods.  相似文献   

13.
Summary Fourth instar larvae of the stick insect,Carausius morosus, kept at 20°C in 16:8 LD, contained about 10 g/animal of epidermal ommochrome. Surgical removal of the ventral half of each eye caused an increase to 110 g/animal. A similar response (90 g/animal) is produced by masking the ventral eye-halves with black varnish. Masking or surgically removing the dorsal half of each eye only caused a slight increase (20 g/animal).The effect of total blinding, either by surgical removal of the eyes or optic lobes, or by electro-coagulation of the eyes, was similar to that of total darkness (40–60 g/animal). The effects of blinding were not enhanced by keeping the insects in total darkness. Eyes that had been destroyed or removed did not regenerate but were replaced by plain cuticle at subsequent moults. Consequently the blinding persisted through the following instars, and the fresh adults contained 300–600 g/animal as compared to 23 g in untreated animals.The results indicate that the effects of illumination on ommochrome pigmentation are mediated entirely through the compound eyes. Removal, destruction or disconnection of eyes or parts of them produced the same response as did lack of light stimulation in the same eyes or parts of eyes when left intact.First communication: J. Comp. Physiol.115, 185–193 (1977)Dedicated to Professor Peter Karlson on the occasion of his 50th birthday  相似文献   

14.
Three species of Nadejdolepis from Tasmania, Australia, are described and illustrated. N. burgessi n. sp., a parasite of Charadrius ruficapillus, is 4-6 mm long, with rostellar nitiduloid hooks 63-66 m long, a short evaginated cirrus 13-16 m long with a short collar of thin spines 1 m long, a narrow and tubular sclerotinoid vagina 40-50 long and 3-4 m in diameter with a little ampulla 3-5 m in diameter at the proximal end, and a membranous atrial segment with smooth, short (1 m) and compact spines which are sometimes difficult to observe. N. smithi n. sp., a parasite of 40-50 long and 3-4 m in diameter with a little ampulla 3-5 m in diameter at the proximal end, and a membranous atrial segment with smooth, short (1 m) and compact spines which are  相似文献   

15.
Callus development in Callistemon viminalis was readily achieved when axillary buds derived from nodal tissue were placed in a medium containing macro- and micro-nutrients, sucrose (0.06 M), inositol (300 M), nicotinic acid (20 M), pyridoxine hydrochloride (3 M), thiamine hydrochloride (2 M), riboflavin (10 M), cytokinins (5 M) and auxins (0.1 M). The presence of benzylaminopurine (5 M) and p-chlorophenoxyacetic acid (0.1 M) promoted the most vigorous callus development and sprout formation. Rooting of nodal material was rare but occurred readily following the transference of sprouts developed on callus to a basal medium containing sucrose and salts. Root initiation was stimulated, however, by the presence of auxins. Chlorophenoxyacetic acid while stimulating root initiation repressed root growth. Indole butyric acid stimulated both root initiation and shoot growth at concentrations of 0.005 to 0.1 M. The treatment of choice for rooting and shoot growth was the addition of indole butyric acid at a concentration of 0.01 M.  相似文献   

16.
Studies were undertaken in order to improve the micropropagation ofCymbidiun ensifolium 'Yuh Hwa. It is easy toinduce rhizomes in vitro in this cultivar but not upright shoots, which areneeded for eventual production of a flowering plant. Exposure ofCymbidium ensifolium 'Yuh Hwa rhizomeexplants in vitro to greater than 2.5 M BA for 12weeks or longer inhibited both elongation of upright, aerial shoots and rootgrowth. Through transfer experiments, it was determined that the commitment toinduction of upright shoots occurred after 10–14 days of exposure to 2.5M BA. BA supplied at 20 M during the first 14days of culture was sufficient to induce upright shoot formation, but shootelongation did not continue under these conditions. Using radiolabelled BA,adenine was found to be a major metabolite found in the rhizome tissue at day14. BA comprised 37% of the total DPM recovered in rhizomes grown in 20M BA compared to that of 61% of the total DPM recoveredfrom rhizomes grown in 2.5 M BA. The total amount of BA takenup per gram fresh weight was similar for both green and etiolated rhizomesgrownin 2.5 M BA. Rhizomes grown in 20 M BA tookupapproximately five times as much BA as those grown in 2.5 MBA.Free IAA levels were highest in the rhizome tip (12.7 ng/g FW) anddecreased to one fourth the value at 1 cm behind the tip. Free IAAlevels increased initially in rhizornes transferred to medium with or without20M BA (although at different amounts) and then decreased. Whenactivated charcoal was added to the medium as well as BA there was no initialincrease in IAA. When 20 M BA was added to the medium, solubleperoxidase activity increased while IAA concentrations remained at about thesame level over a 7-day period. Peroxidase activity in rhizomes eitherdecreasedor remained constant when activated charcoal was added to the medium containingBA.  相似文献   

17.
Summary Respiration of an undescribed species of soil nematode of the genus Chiloplacus from the Canadian High Arctic was measured at 2°, 5°, 10°, 15°, 20° and 25°C. The corresponding metabolic rates were 0.2697×10-3 l, 0.3406×10-3 l, 0.8408×10-3 l, 0.8539×10-3 l, 1.8420×10-3 l and 2.9360×10-3 l O2 ind-1 h-1, respectively, for a nematode of 1.0 g dry weight. The relationship between respiration and dry weight for Chiloplacus sp. at 10°C is described by the function log R=-3.0693+0.8844 log W. Q10 values for the 2°–5°, 5°–10°, 10°–15°, 15°–20° and 20°–25°C temperature intervals were 2.18, 6.09, 1.03, 4.65 and 2.54, respectively. Chiloplacus sp. showed raised metabolic rates at low tempetatures compared with species from warmer environments. Metabolic rates of representative samples of the soil, nematode fauna (dominated by individuals of the genus Plectus) from the same location were 0.1593×10-3 l, 0.3603×10-3 l and 0.5332×10-3 l O2 ind-1 h-1 at 5°, 10° and 15°C for an average nematode of 0.4297 g dry weight.  相似文献   

18.
Two cell lines of Vinca major L. cv. variegata produced strictosidine lactam as the main alkaloid. Quantities varied from 500–1000 g/g DW in the high-yielding line and 1–100 g/g DW in the low-yielding line. Transfer of cells to alkaloid production medium resulted in a 6–8 fold increase in alkaloid production with the high-yielding line, some increase in the low-yielding line and in both lines induced intense greening (up to 200 g chlorophyll/g DW) indicating chloroplast differentiation. Though in the source plant leaves are the main storage site, no correlation between alkaloid accumulation and chloroplast differentiation could be found.NRCC No. 26184.  相似文献   

19.
The relationship of taurine to glutamate, and to other amino acids, has been examined in the occipital lobe of the developing rhesus monkey. During development taurine decreases in concentration (4.96 mol/g in fetus to 1.52 mol/g in adult) while glutamate increases (7.92 mol/g in fetus to 11.26 mol/g in adult). When the concentration of taurine is plotted against that of glutamate in fetal, neonatal and adult animals there is a significant correlation in the fetal (p<0.01) and adult (p<0.01) but not in the neonatal occipital lobe samples. This correlation in both fetal and adult brain is specific for these two amino acids. Subcellular fractionation studies further indicate that this relationship may be of special importance in nerve endings.This paper is dedicated to Dr. Derek Richter on his seventy-fifth birthday.  相似文献   

20.
Thyroid hormones effectively inhibited partially purified cyclic AMP phosphodiesterase from the anterior and posterior lobes of bovine pituitary gland competitively with the substrate, but thyronine, diiodotyrosine, monoiodotyrosine, thyrotropin, thyrotropin releasing hormone, dexamethasone, and luteinizing hormone releasing hormone did not inhibit this enzyme activity.K i values were found to be 1.0 and 2.5 M for thyroxine, and 8.0 and 13.5 M for triiodothyronine in the anterior and posterior lobes, respectively.  相似文献   

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