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91.
David Schwartz Katherine DeSchryver-Kecskemeti Philip Needleman 《Prostaglandins & other lipid mediators》1984,27(4):605-613
The process of renal inflammation was examined using the partial renal vein constricted rabbit kidney (RVC) as a model. Forty eight hours of partial renal vein constriction in the rabbit was associated with an increase in prostaglandin (PG) and thromboxane (Tx) production. The
perfused RVC kidney showed an enhanced time-dependent increase in PG and Tx production in response to bradykinin stimulation when compared with the unlatered contralateral (CLK) or normal kidney. At 6 hrs of perfusion bradykinin stimulation lateral (CLK) or normal kidney. At 6 hrs of perfusion bradykinin stimulation released 2950±350 ng PGE2, 61±15 ng TxB2 from the RVC, and 225±85 ng PGE2 and undetectable TxB2 from the CLK. Histological examination of the RVC cortex showed an increase in fibroblast-like cells, a modest increase in the interstitial space and an appearance of macrophages and lymphocytes not seen in the normal of CLK. Endotoxin has been reported to stimulate macrophages in culture to produce PGE2 and TxB2. Endotoxin (100 ng)_stimulation of the perfused RVC kidney caused an immediate, followed by a chronically increasing, release of PGs and Tx. Two hours after endotoxin injection 50 ml of effluent fromt the RVC contained 1450±107 ng PGE2 and 15.0±4.5 ng TxB2. Other models of renal inflammation (e.g., the hydronephrotic kidney, chronic glomerulonephritis) also show the histological appearance of macrophages. In addition, hydronephrotic kidneys undergo fibroblast proliferation and changes in arachidonic acid metabolism similar to what we observed in the RVC. This work suggests that the inflammatory process (mononuclear cell infiltration), fibroblast-like cell proliferation, and accompanying changes in arachidonate metabolism) is common among different forms of renal injury. 相似文献
92.
A survey of dermatophytes isolated from patients seeking medical advice was made from 1979 to 1981 in the United States. The survey included 54 locations with data from 40 cities and 2 states. Correlations of these data with that of the other localities of the world were made to illustrate the dynamic epidemiology of several common dermatophytes. The most often isolated dermatophyte in this survey was Trichophyton rubrum having 53.66% of the total for these three calendar years. In a chronological listing of ringworm infections caused by this organism, many areas of the world have reported similar increased incidence of this pathogen. Trichophyton tonsurans was isolated 27.85% of the total. A dramatic increase of this pathogen as a cause of tinea capitis has been observed in most cities of the United States. It has been isolated in 25 different countries of the world. The percentage of isolation of Trichophyton mentagrophytes was 8.56%. This percentage may not be near the true incidence of infection by this dermatophyte because the infections are mild and respond to treatment without the individual seeking medical advice. Since the 1950s the percentage of isolations of the total has dropped for T. mentagrophytes in the United States. Epidermophyton floccosum accounted for 4.36% of the total. In a few areas of the world it causes over 30% of the total of dermatophytoses. Microsporum canis was isolated 3.72% of the total in the United States. It has recently been reported to be the dominant agent of tinea capitis in several South American countries, Tucson, Arizona and Kuwait. Once the dominant pathogen of tinea capitis in children in the United States, it was replaced by Microsporum audouinii before 1960. Today in the United States, M. audouinii only accounts for 0.30% of the total. It is considered eliminated as a pathogen in England. In this survey, isolated less than 1.0% of the total were Microsporum gypseum, Microsporum ferrugineum, Microsporum nanum, Microsporum fulvum and Trichophyton schoenleinii. Trichophyton meginii and Trichophyton terrestre were reported isolated but no numerical data were available. 相似文献
93.
Summary Endings of four skeletofusimotor axons in a spindle of the cat tenuissimus muscle were examined in semithin (1-m thick) and ultrathin transverse serial sections. Two (dynamic) axons terminated on the nuclear bag1 intrafusal muscle fiber and on extrafusal fibers of the dark type. Two (static) axons terminated on the nuclear chain intrafusal fibers and extrafusal fibers of the intermediate type. The degree of indentation of axon terminals into the muscle surface, thickness of the sole plate and extent of folding of subjunctional membranes differed among intrafusal and extrafusal terminations of the same axon. Endings of axons on the bag1 and chain fibers were also morphologically dissimilar. Motor axons may not determine ending morphology. Rather the form and structure of a bag1 or chain ending may be determined by the type of intrafusal fiber on which the ending lies and the ending's distance from the primary sensory axon. 相似文献
94.
95.
The structural filament network of the nucleus is prepared while still connected to the cytoskeleton. The relatively gentle procedure removes about 98% of the DNA and at least 86% of the histones. The matrix is bounded by an outer nuclear lamina connected to the cytoskeletal framework, as well as the inner filaments. The filaments range in diameter from 3 to 22 nm, and are organized in a three-dimensional anastomosing network in which nucleoli are enmeshed. The nuclear matrix is separated from the cytoskeletal framework by a double detergent and then partitioned into a chromatin fraction and a matrix fraction by nuclease and high salt. Two-dimensional gel electrophoresis shows that the proteins of the cytoskeleton, chromatin and nuclear matrix are very different. A major protein found in all fractions cofocuses with actin. Vimentin is largely associated with the nuclear matrix, probably as a corona external of filaments. 相似文献
96.
97.
Veronica M. Maher J. Justin McCormick Phillip L. Grover Peter Sims 《Mutation research》1977,43(1):117-137
The cytotoxicity of the “K-region” epoxides as well as several other reactive metabolites or chemical derivatives of polycyclic hydrocarbons was compared in normally-repairing human diploid skin fibroblasts and in fibroblasts from a classical xeroderma pigmentosum (XP) patient (XP2BE) whose cells have been shown to carry out excision repair of damage induced in DNA by ultraviolet (UV) radiation at a rate approx. 20% that of normal cells. Each compound tested exhibited a 2- to 3-fold greater cytotoxicity in this XP strain than in the normal strain. To determine whether this difference in survival reflected a difference in the capacity of the strains to repair DNA damage caused by such hydrocarbon derivatives, we compared the cytotoxic effect of several “K-region” epoxides in two additional XP strains, each with a different capacity for repair of UV damage. The ration of the slopes of the survival curves for each of the XP strains to that of the normal strain, following exposure to each epoxide, was very similar to that which we had previously determined for their respective UV curves, suggesting that human cells repair damage induced in DNA by exposure to hydrocarbon derivatives with the same system used for UV-induced lesions.To determine whether the deficiency in rate of excision repair in this classical XP strain (XP2BE) causes such cells to be abnormally susceptible to mutations induced by “K-region” epoxides of polycyclic hydrocarbons, we compared them with normal cells for the frequency of induced mutations to 8-azaguanine resistance. The XP cells were two to three times more susceptible to mutations induced by the “K-region” epoxide of benzo(a)pyrene (BP), 7,12-dimethylbenz(a)anthracene (DMBA), and dibenz(a,h)anthracene (DBA). Evidence also was obtained that cells from an XP variant patient are abnormally susceptible to mutations induced by hydrocarbon epoxides and, as is the case following exposure to UV, are abnormally slow in converting low molecular weight DNA, synthesized from a template following exposure to hydrocarbon epoxides, into large-size DNA. 相似文献
98.
Metabolism and activation of benzo[a]pyrene by mouse and rat skin in short-term organ culture and in vivo 总被引:1,自引:0,他引:1
The metabolic activation of BP was examined in mouse and rat skin in vivo and in short-term organ culture. In mouse skin, larger quantities of ether- and water-soluble metabolites were formed and more BP became bound covalently to DNA and protein than in rat skin. Qualitative differences in the formation of dihydrodiol metabolites and of BP-deoxyribonucleoside adducts between mouse and rat skin were also observed. Organ culture techniques may not provide a true model of metabolic activation in vivo because it was found that the covalent binding of BP to DNA and protein was reduced in skin maintained in culture despite an accumulation of dihydrodiol and other ether-soluble metabolites. In addition, the proportions of the syn- and anti-isomers of BP-7,8-diol 9,10-oxide involved in the formation of adducts with deoxyguanosine differed between skin treated in organ culture and in vivo. 相似文献
99.
Agneta Oskarsson Katherine S. Squibb Bruce A. Fowler 《Biochemical and biophysical research communications》1982,104(1):290-298
Gel chromatography of kidney postmitochondrial fractions from control rats 2 hr after injection of 203Pb or after in vitro incubation with 203Pb disclosed the presence of two fractionated Pb-binding components plus binding in the void volume and total volume regions. The binding of Pb to the two components, with molecular weights of 11,500 and 63,000 daltons, was markedly decreased in Pb-pretreated rats. Sodium dodecyl sulfate-gel electrophoresis and autoradiography showed the presence of one major 203Pb band with an estimated molecular weight of 60,000 daltons. The 11,500-dalton peak did not incorporate 14C-leucine nor did concomitant administration of cycloheximide with the 203Pb inhibit incorporation of 203Pb activity, suggesting that the component is a preformed constituent of the kidney. In vitro incubation of brain, liver and lung postmitochondrial supernatants with 203Pb disclosed that these two binding components were also present in brain but not in liver or lung, suggesting a target tissue-specific localization for these Pb-binding macromolecules. 相似文献
100.