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Immunization of mice with a synthetic GM3-lactam-BSA (bovine serum albumin) conjugate (designed to emulate the corresponding natural GM3-lactone conjugate), followed by fusion of splenocytes with myeloma cells, gave rise to more than 300 monoclonal hybridomas producing antibodies to GM3-lactam-BSA, which did not react with Glc-BSA and BSA. Eight antibody clones were randomly chosen from the positive 300 hybridomas. The eight clones, all belonging to the IgG class, were unreactive against GM3-ganglioside, whereas two antibodies (P5-1 and P5-3, both IgG1, ) reacted with GM3-ganglioside lactone. Binding of these two antibodies to the GM3-lactam-BSA conjugate was inhibited by soluble glycosides of GM2-, GM3-, and GM4-lactam and by GM3- and GM4-lactam, respectively, but not by Gb3 or asialo-GM1 and GM2-saccharides. A third antibody (P3; IgG2b, ) was inhibited by GM2-, GM3-, and GM4-lactam, but did not recognize GM3-ganglioside lactone. 相似文献
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Mária Zsófia Koltai Peter Rösen Pál Hadházy Zoltán Aranyi György Ballagi-Pordány Gábor Pogátsa 《Molecular and cellular biochemistry》1992,109(2):189-196
The aim of this study was to clarify whether or not arachidonic acid metabolic disorders are caused by a substrate inavailability and whether such disorders might contribute to circulatory disturbances in the diabetic myocardium. Norepinephrine induced a decrease in the conductivity of both coronary arterial bed and myocardial microcirculation in alloxan-diabetic dogs. It was markedly (p < 0.05) attenuated both by indomethacin and acetylsalicylic acid pretreatments indicating an imbalance among the vasoactive prostanoids in diabetes. TXA2 release from the diabetic coronary rings was found to be elevated and could be normalized after the blockade of vascular adrenoceptors by phentolamine (p < 0.05). PGIZ synthesis was also enhanced by adrenergic blockade in the diabetic arterial rings. After pretreatment with l4C arachidonic acid, in order to measure substrate availability, the arachidonic acid metabolic rate was less in the diabetic coronary arteries than in healthy vessels (p < 0.05). Ten µmol/1 norepinephrine decreased arachidonic acid metabolism in the presence of prelabelled substrate in the diabetic animals, compared to an increase observed in metabolically healthy dogs. Therefore diabetes appears to diminish arachidonic acid metabolism and uptake independent of adrenoceptors and to induce an imbalance between vasoconstrictor and vasodilator cyclooxygenase products, resulting in elevated TXA2 release controlled by adrenergic mechanisms which may contribute to an impairment in myocardial microcirculation.Abbreviations 6-oxo-PGF1
6-oxo prostaglandin F1
- HPLC
High Pressure Liquid Chromatograph
- LAD
Left Anterior Descending (coronary artery)
- PGI2
Prostacyclin
- TXA2
Thromboxane 相似文献
127.
Summary An antiserum against conjugated histamine and two oligonucleotide probes that detect the mRNA encoding L-histidine decarboxylase (HDC) involved in histamine synthesis were used to study the appearance of histamine and its location in the kidneys of fetal, newborn and young postnatal rats and in the kidneys of pregnant rats. On embryonic days 16 and 18 (E16 and E18), some HA-immunoreactive (HA-ir) cells were found within the largest S-shaped bodies. Histamine was found to appear rapidly between the 18th and 20th embryonic days in the convoluted tubules of the kidneys. On postnatal day 0 (P0), the distal convoluted tubules and collecting ducts exhibited bright fluorescence, the intensity of which decreased quickly so that it was faint on day P4 and absent at later stages. In kidneys of pregnant rats HA-ir was found in the epithelium of both the Bowman's capsule, collecting ducts and in a few cells within the tubules. Nonuniform HA-ir was also detected within glomeruli. No evidence for the presence of L-histidine decarboxylase mRNA in kidneys of fetuses or pregnant rats was seen. It is concluded that distinct structures in the developing rat kidney contain histamine during a period around birth from day E20 to day P4. In the pregnant rat, the epithelium that is in direct contact with the urine flow is immunoreactive for histamine from day 16 to 20 of pregnancy. The results suggest that histamine is not synthesized locally in the kidneys but rather originates from other tissues. 相似文献
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Catharina Larsson Günther Weber Eva Kvanta Kathy Lewis Marie Janson Carol Jones Tom Glaser Glen Evans Magnus Nordenskjöld 《Human genetics》1992,89(2):187-193
Summary Multiple endocrine neoplasia type 1 (MEN1) is characterized by neoplasia of the parathyroids, the pancreas, and the pituitary. Tumorigenesis involves unmasking of a recessive mutation at the MEN1 locus, which has been mapped to the centromeric part of chromosomal region 11q. In order to localize the MEN1 gene further and to make its isolation possible, a number of new markers were isolated. Two radiation-reduced somatic cell hybrids were identified that only contained markers close to and flanking the MEN1 region. DNA from these hybrids was used for the construction of a cosmid library, and clones containing human inserts were isolated. In addition, cosmid clones were isolated for locus expansion of 7 other markers that were mapped to the 11q12–13.2 region. The 33 newly isolated clones together with 25 previously published markers from this region were analyzed in a panel of radiation-reduced somatic cell hybrids. From the hybridization pattern, the region was divided into 11 parts. New restriction fragment length polymorphisms were identified in 7 of the newly isolated cosmid clones and in one plasmid. These were then used to sublocalize meiotic cross-overs more precisely in two MEN1 families, thus refining the mapping of the disease gene. 相似文献
130.
Dan -E. Nilsson Kurt Hamdorf Gunnar Höglund 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1992,170(2):217-226
Summary In the superposition eyes of the sphingid moth Deilephila and the neuropteran Ascalaphus, adjustment to different intensities is subserved by longitudinal migrations of screening pigment in specialized pigment cells. Using ophthalmoscopic techniques we have localized the light-sensitive trigger that controls pigment position.In both species, local illumination of a small spot anywhere within the eye glow of a dark-adapted eye evokes local light adaptation in the ommatidia whose facets receive the light. Details of the response pattern demonstrate that a distal light-sensitive trigger is located axially in the ommatidium, just beneath the crystalline cone, and extends with less sensitivity deep into the clear zone. The distal trigger in Deilephila was shown to be predominantly UV sensitive, and a UV-absorbing structure, presumably the distal trigger, was observed near the proximal tip of the crystalline cone.In Ascalaphus we also found another trigger located more proximally, which causes local pigment reaction in the ommatidia whose rhabdoms are illuminated (the centre of the eye glow). The light-sensitive trigger for this response appears to be the rhabdom itself. 相似文献