首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
《Insect Biochemistry》1990,20(6):619-623
An α-glucosidase from the adult salivary glands of the vector mosquito, Aedes aegypti, was characterized. The α-glucosidase is a soluble glycoprotein with Mr 68,000 that is secreted when mosquitoes take a sugar meal. Total activity in the salivary glands is equal between males and females with 82% of the activity in female glands being present in the proximal-lateral lobes. The characteristics of the α-glucosidase correlate well with the putative protein encoded by the Maltase-like I gene. The α-glucosidase is most likely involved in sugar digestion.  相似文献   

2.
Summary The intercellular junctions that occur in the hypodermis, Gené's organ, and the salivary glands of the tick, B. microplus, are described. The epithelial cells of the hypodermis are connected by spot desmosomes and septate junctions and the secretory cells of Gené's organ by septate and gap junctions. The cap cells in the alveoli of the salivary gland connect to adjacent cells by gap junctions, hemidesmosomes and septate junctions into which microtubules are inserted.The authors would like to thank Mr. R. Lamb for preparing the plates. M.W.J. Megaw was supported by an S.R.C. Studentship  相似文献   

3.
The number of scale insect species (Hemiptera: Coccoidea) known from Hungary has increased in the last 10 years by 39 (16.6 %), to a total of 274 species belonging to 112 genera in10 families. The family Pseudococcidae is the most species rich, with 101 species in 34 genera; Diaspididae contains 59 species in 27 genera; Coccidae contains 54 species in 27 genera; and the Eriococcidae contains 33 species in 8 genera. The other 6 coccoid families each contain only a few species: Asterolecaniidae (7 species in 3 genera); Ortheziidae (7 species in 4 genera); Margarodidae sensu lato (5 species in 5 genera); Cryptococcidae (3 species in 2 genera); Kermesidae (4 species in 1genus); and Cerococcidae (1 species). Of the species in the check list, 224 were found in outdoor conditions, while 50 species occurred only in indoor conditions. This paper contains 22 species recorded for the first time in the Hungarian fauna.  相似文献   

4.
Summary The three major salivary glands of normal male and female Fischer 344 rats of different ages were examined for the localization of epidermal growth factor (EGF) and transforming growth factor (TGF) by immunohistochemical staining. EGF was demonstrated only in the granulated convoluted tubule (GCT) cells of the submandibular gland, the results confirming the previous reports, and most abundantly in adult males and pregnant females. TGF stain was localized in all three glands and was found throughout the entire duct system, excluding acinar cells. The myoepithelial cells of the sublingual gland were also reactive with the TGF antibody. The specificity of the staining was confirmed by negative staining reaction with the absorbed antibody and by radio-immunoassay and Western blot methods. This is the first report describing the presence of TGF in the rat salivary glands.  相似文献   

5.
Lagenidium giganteum Couch, a watermold parasitic on mosquito larvae possesses an intracellular -d-glucosidase (-d-glucoside glucohydrolase, E. C. 3.2.1.21). The enzyme was purified 132 fold and, with the substrate p-nitrophenyl -d-glucoside, was shown to have the following properties: The pH of optimum enzyme stability and activity lay between 5.5 and 6.0, and the enzyme was inactivated at temperatures above 50°C. The K m was 4.6×10-5 M and the Arrhenius activation energy was 8.35 Kcal·mole-1. Elution from Sephadex G-200 gave an approximate molecular weight of 120000. The enzyme was inhibited by Pb2+, Ag2+ and Hg2+, by glucose and by p-chloromercuribenzoate. The latter inhibition was overcome cy cysteine. Chromatographic studies demonstrated transferase as well as hydrolase properties.This paper represents a portion of a Ph.D. dissertation presented by T. M. McInnis, Jr., to the University of North Carolina at Chapel Hill. The work was supported in part by grants from the American Cancer Society, the University of North Carolina Research Council, the Society of Sigma Xi, and a United States Army Medical Research DevelopmentGrant DADA 17-72-C-2168.  相似文献   

6.
The Greater White-toothed shrew Crocidura russula is short-lived species and the phase of senescence is greatly elongated in captivity. The loss of rhythmicity of biological functions that accompanies its aging is also well documented. C. russula is thus an excellent model to test the effects of aging on biological clocks. Melatonin is a key hormone in the synchronization of behaviors, metabolisms and physiological regulations with environmental factors. In the present work we want to know if the loss of rhythmicity and the reduced melatonin levels registered by the second year of life in this species could be associated to modified ultrastructural features of the pineal parenchyma, site of melatonin synthesis. Transmission electron microscopy (TEM) analysis of young (1-4 months) and old (25-28 months) shrew's pineals show that in older individuals, the parenchyma undergoes alterations affecting mainly nucleus, mitochondria and endoplasmic reticulum cisternae, with increased numbers of dense bodies and the formation of many concretions as well as a depletion of secretory products. These changes suggest a process of slowing pinealocytes metabolism which could explain the gradual reduction of melatonin levels registered during aging in C. russula.  相似文献   

7.
Patients with Sjögren's syndrome (SS) have characteristic lymphocytic infiltrates of the salivary glands. To determine whether the B cells accumulating in the salivary glands of SS patients represent a distinct population and to delineate their potential immunopathologic impact, individual B cells obtained from the parotid gland and from the peripheral blood were analyzed for immunglobulin light chain gene rearrangements by PCR amplification of genomic DNA. The productive immunglobulin light chain repertoire in the parotid gland of the SS patient was found to be restricted, showing a preferential usage of particular variable lambda chain genes (Vλ2E) and variable kappa chain genes (VκA27). Moreover, clonally related VL chain rearrangements were identified; namely, VκA27–Jκ5 and VκA19–Jκ2 in the parotid gland, and Vλ1C–Jλ3 in the parotid gland and the peripheral blood. Vκ and Vλ rearrangements from the parotid gland exhibited a significantly elevated mutational frequency compared with those from the peripheral blood (P < 0.001). Mutational analysis revealed a pattern of somatic hypermutation similar to that found in normal donors, and a comparable impact of selection of mutated rearrangements in both the peripheral blood and the parotid gland. These data indicate that there is biased usage of VL chain genes caused by selection and clonal expansion of B cells expressing particular VL genes. In addition, the data document an accumulation of B cells bearing mutated VL gene rearrangements within the parotid gland of the SS patient. These results suggest a role of antigen-activated and selected B cells in the local autoimmune process in SS.  相似文献   

8.
Patients with Sj?gren's syndrome (SS) have characteristic lymphocytic infiltrates of the salivary glands. To determine whether the B cells accumulating in the salivary glands of SS patients represent a distinct population and to delineate their potential immunopathologic impact, individual B cells obtained from the parotid gland and from the peripheral blood were analyzed for immunoglobulin light chain gene rearrangements by PCR amplification of genomic DNA. The productive immunoglobulin light chain repertoire in the parotid gland of the SS patient was found to be restricted, showing a preferential usage of particular variable lambda chain genes (V lambda 2E) and variable kappa chain genes (V kappa A27). Moreover, clonally related V(L) chain rearrangements were identified; namely, V kappa A27-J kappa 5 and V kappa A19-J kappa 2 in the parotid gland, and V lambda 1C-J lambda 3 in the parotid gland and the peripheral blood. V kappa and V lambda rearrangements from the parotid gland exhibited a significantly elevated mutational frequency compared with those from the peripheral blood (P < 0.001). Mutational analysis revealed a pattern of somatic hypermutation similar to that found in normal donors, and a comparable impact of selection of mutated rearrangements in both the peripheral blood and the parotid gland. These data indicate that there is biased usage of V(L) chain genes caused by selection and clonal expansion of B cells expressing particular V(L) genes. In addition, the data document an accumulation of B cells bearing mutated V(L) gene rearrangements within the parotid gland of the SS patient. These results suggest a role of antigen-activated and selected B cells in the local autoimmune process in SS.  相似文献   

9.
The alkaline and acid phosphatases in larvae of the euryhaline mosquito, Aëdes togoi Theobald, were measured and the distribution of alkaline phosphatase was examined histochemically. The optima pH for alkaline and acid phosphatases in the larvae were ≈9.0 and 3.2. respectively. The thorax region showed the highest activity of alkaline phosphatase. The enzyme activity of the thorax of seawater adapted larvae was about twice as high as that of freshwater larvae. When the larvae were transferred from fresh water to sea water, the alkaline phosphatase activity of the thorax increased greatly for 3 days, and thereafter decreased to the normal level of sea-water adapted larvae within seven days. In larvae transferred from sea water to fresh water, the activity of the thorax decreased gradually and after 7 days remained at the level of freshwater adapted larvae. No change in acid phosphatase activity was detected following transfer of the larvae from fresh water to sea water or vice versa. A strong alkaline phosphatase reaction was found only in the luminal border of the gastric caeca in the thorax region. The locality of this enzyme did not vary according to the salinity of environmental water.The activity change of alkaline phosphatase of the gastric caeca is discussed in relation to the absorption of the ingested medium from the gastric caeca.  相似文献   

10.
A critical and annotated catalogue of 183 types of Hymenoptera Chrysididae belonging to 124 taxa housed in the Radoszkowski collection is given. Radoszkowski type material from other institutes has also been checked. Six lectotypes are designated in Kraków (ISEA-PAN): Chrysis acceptabilis Radoszkowski, 1891; Chrysis persica Radoczkowsky, 1881; Chrysis daphnis Mocsáry, 1889; Chrysis lagodechii Radoszkowski, 1889; Chrysis remota Mocsáry, 1889 and Chrysis vagans Radoszkowski, 1877. The lectotype of Brugmoia pellucida Radoszkowski, 1877 is designated in Moscow (MMU). Four new combinations are proposed: Philoctetes araraticus (Radoszkowski, 1890), comb. n.; Pseudomalus hypocrita (du Buysson, 1893), comb. n.; Chrysis eldari (Radoszkowski, 1893), comb. n.; and Chrysura mlokosewitzi (Radoszkowski, 1889), comb. n.. Ten new synonyms are given: Chrysis auropunctata Mocsáry, 1889, syn. n. of Chrysis angolensis Radoszkovsky, 1881; Chrysis chrysochlora Mocsáry, 1889, syn. n. and Chrysis viridans Radoszkowski, 1891, syn. n. of Chrysis keriensis Radoszkowski, 1887; Chrysis angustifrons var. ignicollis Trautmann, 1926, syn. n. of Chrysis eldari (Radoszkowski, 1893); Chrysis maracandensis var. simulatrix Radoszkowski, 1891, syn. n. of Chrysis maracandensis Radoszkowski, 1877; Chrysis pulchra Radoszkovsky, 1880, syn. n. of Spinolia dallatorreana (Mocsáry, 1896); Chrysis rubricollis du Buysson, 1900, syn. n. of Chrysis eldari (Radoszkowski, 1893); Chrysis subcoerulea Radoszkowski, 1891, syn. n. of Chrysis chlorochrysa Mocsáry, 1889; Chrysis therates Mocsáry, 1889, syn. n. of Chrysis principalis Smith, 1874; and Notozus komarowi Radoszkowski, 1893, syn. n. of Elampus obesus (Mocsáry, 1890). One species is revaluated: Chrysis chalcochrysa Mocsáry, 1887. Chrysis kizilkumiana Rosa is the new name for Chrysis uljanini Radoszkowski & Mocsáry, 1889 nec Radoszkowski, 1877. Pictures of seventy-seven type specimens are given.  相似文献   

11.
Exocrine glands play an important role in maintaining the integrity of colonies of social Hymenoptera. The postpharyngeal gland (PPG) of ants is crucial for the generation of a nest odour that enables nestmate recognition. The evolutionary history of this gland is unknown and it was thought to be restricted to ants. Here we describe an exocrine head gland in females of a solitary crabronid wasp, the European beewolf, Philanthus triangulum, that resembles the PPG of ants in many respects. The newly described gland has the same location and the same glove like shape as in ants, and it also has a monolayered epithelium with similar ultrastructure. Unlike in ants, the epithelium bears hairs that reach into the lumen of the gland. Although the PPG of beewolves serves a completely different function it is also associated to an allogrooming behaviour as in ants. Based on these morphological and behavioural similarities as well as similarities in the chemical composition of the content of the PPG of both taxa, we hypothesise that the PPGs of ants and beewolves have a common evolutionary origin. Thus, our results suggest that the PPG in ants might not have evolved in response to social requirements but might have already existed in solitary predecessors.  相似文献   

12.
The relationship between myonuclear number, cellular size, succinate dehydrogenase activity, and myosin type was examined in single fiber segments (n=54; 9±3 mm long) mechanically dissected from soleus and plantaris muscles of adult rats. One end of each fiber segment was stained for DNA before quantitative photometric analysis of succinate dehydrogenase activity; the other end was double immunolabelled with fast and slow myosin heavy chain monoclonal antibodies. Mean±S.D. cytoplasmic volume/myonucleus ratio was higher in fast and slow plantaris fibers (112±69 vs. 34±21x103 m3) than fast and slow soleus fibers (40±20 vs. 30±14x103 m3), respectively. Slow fibers always had small volumes/myonucleus, regardless of fiber diameter, succinate dehydrogenase activity, or muscle of origin. In contrast, smaller diameter (<70 m) fast soleus and plantaris fibers with high succinate dehydrogenase activity appeared to have low volumes/myonucleus while larger diameter (>70 m) fast fibers with low succinate dehydrogenase activity always had large volume/myonucleus. Slow soleus fibers had significantly greater numbers of myonuclei/mm than did either fast soleus or fast plantaris fibers (116±51 vs. 55±22 and 44±23), respectively. These data suggest that the myonuclear domain is more limited in slow than fast fibers and in the fibers with a high, compared to a low, oxidative metabolic capability.  相似文献   

13.
《Journal of bryology》2013,35(1):57-80
Abstract

On the subantarctic and temperate islands of the eastern Southern Hemisphere (90°E to 0°) 66 Hepaticae and two Anthocerotae species are recorded, among them ten are recorded for the first time. The reports of a further 18 are rejected. Fifteen species and five variety names are newly synonymized. Nineteen species and two subspecies are regarded as endemics. Among the recorded species, 75% are only or mainly known from the Subantarctic Zone. Species otherwise known also from southernmost South America predominate, contrary to its geographical distance, whereas those otherwise known only from the closer Africa are weakly represented and those known only from Australasia are almost lacking.  相似文献   

14.
The type status is described of 96 taxa classified within the superfamily Orthalicoidea and present in the Mollusca collection of the Museum für Naturkunde der Humboldt-Universität zu Berlin. Lectotypes are designated for the following taxa: Orthalicus elegans Rolle, 1895; Bulimus maranhonensis Albers, 1854; Orthalicus nobilis Rolle, 1895; Orthalichus tricinctus Martens, 1893. Orthalicus sphinx tresmariae is introduced as new name for Zebra sphinx turrita Strebel, 1909, not Zebra quagga turrita Strebel, 1909. The following synonyms are established: Zebra crosseifischeri Strebel, 1909 = Orthalicus princeps fischeri Martens, 1893; Orthalicus isabellinus Martens, 1873 = Orthalicus bensoni (Reeve, 1849); Zebra zoniferus naesiotes Strebel, 1909 = Orthalicus undatus (Bruguière, 1789); Porphyrobaphe (Myiorthalicus) dennisoni pallida Strebel, 1909 = Hemibulimus dennisoni (Reeve, 1848); Zebra delphinus pumilio Strebel, 1909 = Orthalicus delphinus (Strebel, 1909); Orthalicus (Laeorthalicus) reginaeformis Strebel, 1909 = Corona perversa (Swainson, 1821); Bulimus (Eurytus) corticosus Sowerby III, 1895 = Plekocheilus (Eurytus) stuebeli Martens, 1885. The taxon Bulimus (Eudioptus) psidii Martens, 1877 is now placed within the family Sagdidae, tentatively in the genus Platysuccinea. Appendices are included with an index to all the types of Orthalicoidea extant (including those listed by Köhler 2007) and a partial list of letters present in the correspondence archives.  相似文献   

15.
16.
INTRODUCTIONEstrogen has been known to exert extensive effects via estrogen receptor (ER) on diverse physio-logical and develoPmental functions of the brain[1,2]. It has been observed that the distribution ofthe classical ER subtype-a (ERa) and the recentlycharacterized novel ER subtype--fi (ERg), and theirexpression patterns (ERcr/ERfi) vary greatly amongvarious brain regions[1, 3]. These evidences suggestthat each ER subtype may play a different role inestrogen's effects on the br…  相似文献   

17.
18.
19.
20.
Intracarotid infusions of noradrenaline (0.15 nmol · kg−1 · min−1) either alone or accompanied by phentolamine (1.5 nmol · kg−1 · min−1) caused similar-sized increases in salivary protein, magnesium and bicarbonate, and decreases in osmolality, sodium, potassium and chloride whereas intravenous noradrenaline stimulated much smaller responses. Concurrent infusions of the β1-antagonist, CGP20712A, blocked these noradrenaline-induced changes in salivary composition more effectively than equimolar infusions of the β2-antagonist, ICI118551, thereby confirming the presence of β1-adrenoceptors. Intracarotid infusion of salbutamol at 0.15, 0.3 and 1.5 nmol · kg−1 · min−1 caused increasing but qualitatively similar changes in salivary composition, sodium excepted, to intracarotid noradrenaline with 0.3 nmol being most similar quantitatively. Intravenous infusion of salbutamol caused larger changes in salivary composition than equimolar intravenous noradrenaline thereby indicating that the response to salbutamol may, in part, be mediated by reflex increases in general sympathetic tone triggered by lowered blood pressure. Eliminating this hypotensive effect by concurrent intravenous and intracarotid infusions of β1-(CGP or atenolol) and β2-(ICI118551) antagonists with intracarotid salbutamol showed that ICI118551 was more potent than the β1-antagonists thereby demonstrating the presence of β2-receptors. It was concluded that the kangaroo mandibular has functional β1- and β2-adrenoceptor subtypes in both endpieces and excurrent ducts and that the duct system has two populations of cells, each expressing one receptor subtype. Accepted: 26 July 2000  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号