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51.
The results of 209 liver biopsy needle washings were compared with the corresponding histologic findings. An effort was made to distinguish major categories of liver disease on the basis of cytologic findings. Pigment identification and fat quantitation were also evaluated. It was found that it was often possible to determine whether a liver needle washing was normal or abnormal; however, it was rarely possible to provide specific diagnoses. Pure fatty change and primary cholestasis could be reliably differentiated from the steatosis and bile plugging seen in other liver disorders. Cirrhosis could be suggested in a limited number of cases, although in most cases the findings were nonspecific. Cytology was found to be less reliable than biopsy in the discrimination between the major pigments. Finally, cytology was an acceptable method for detecting and quantitating fatty change.  相似文献   
52.
The major sesquiterpenes in the foliage of Dacrydium cupressinum are α-longipinene, longifolene, longibornyl acetate, caryophyllene, caryophyllene oxide, humulene, α- and β-selinene, β- and δ-elemene, aromadendrene and the rare 9βH-caryophyllene. Sesquiterpene levels vary greatly from tree to tree. As this variation is largely independent of environmental factors, genetic control is proposed. Longifolene and α-longipinene levels are closely correlated, as are those of caryophyllene and humulene. The biosynthetic implications of these correlations are discussed.  相似文献   
53.
The drug resistance plasmid pKM101 makes Escherichia coli resistant to the lethal effects of ultraviolet (UV) irradiation and more susceptible to mutagenesis by a variety of agents. The plasmid operon responsible for increasing mutagenesis has been termed mucAB (Mutagenesis, UV and chemical). We have isolated a derivative of pKM101 called pGW1975 which makes cells more sensitive to killing by UV but which retains the ability of pKM101 to increase susceptibility to methyl methanesulfonate (MMS) mutagenesis. pGW1975 increases UV mutagenesis less than pKM101 in a uvrA+ strain but more than pKM101 in a uvrA strain. muc point and insertion mutants of pKM101 and pGW1975 complement to restore the plasmid-mediated: (i) ability to reactivate UV-irradiated phage, (ii) resistance to killing by UV, and (iii) level of susceptibility to UV mutagenesis. We have identified a 2.0 kb region of pKM101 which is responsible for the complementation and which maps counterclockwise of mucAB.  相似文献   
54.
Addition of calcium chloride to an egg homogenate of Strongylocentrotus purpuratus stimulates O2 consumption which is not inhibited by millimolar cyanide. Results strongly suggest that Ca2+-stimulated O2 consumption is at least partially the result of polyunsaturated fatty acid oxidation. First, addition of arachidonic acid (AA), or other polyunsaturated fatty acids, to the homogenate enhance Ca2+-stimulated O2 consumption; this enhancement, by AA, being coupled to its oxidation to a hydroxy fatty acid. Second, calcium stimulates a lipase activity in the homogenate that is capable of releasing free fatty acids. Third, Ca2+-stimulated O2 consumption and AA oxidation have virtually identical calcium requirements and pH optima. The sequence of events then is that upon calcium addition to the homogenate, lipase activity is increased which liberates free fatty acids. At the same time calcium also activates a polyunsaturated fatty acid oxygenase, possibly lipoxygenase, that converts the free fatty acids to hydroxy fatty acids. The possible physiological importance of this reaction is underscored by the high affinity for Ca2+ [approximately 10(-7)M], an ion known to increase above the required levels at fertilization. The pH activity profile also suggests possible physiological modulation because a pH change of 6.8 increasing to 7.2, as suggested to occur after fertilization, yields almost a twofold increase in O2 consumption. Egg homogenates from many other invertebrate species have the ability to oxidize AA in a Ca2+-dependent fashion. For the investigated species, the presence of Ca2+-stimulated O2 consumption and AA oxidation correlates with the presence of cyanide insensitive respiration in the intact egg.  相似文献   
55.
In 1980 a long-term study of the fishery resources of the San Francisco Bay estuary was initiated in an effort to delineate the importance of freshwater inflow to fish and invertebrate abundance and distribution in the bay. An analysis of the trawl data collected between January 1980 and December 1982 illustrates the influence of the timing and magnitude of freshwater inflows on fish fistribution and abundance in this estuary from the perspective of monthly, seasonal and annual time scales. Normally found in the delta, Suisun Bay and San Pablo Bay during periods of increased salinity, pelagic species moved downstream after the two peak flows studied, while demersal species usually found in Central San Francisco Bay moved upstream. Such upstream movements may be due in part to transport by strong density-driven currents.Timing and magnitude of monthly catches of some species varied on a seasonal cycle coincident with variations of freshwater inflow. Most species, especially the marine species, showed no consistent cycle of monthly catches. In the wet years of 1980 and 1982 the distributions of freshwater, estuarine and anadromous species were extended downstream into San Pablo, Central and South San Francisco Bays and some marine species, including the flatfish, were more abundant in the upstream areas. In the dry year of 1981 when bay salinities were higher, few marine species extended their distributions upstream into San Pablo and Suisun Bays. Jacksmelt was the only fish of the 15 most abundant species with its peak abundance in 1981. Most marine species were more abundant in the San Francisco Bay estuary in the wet years.  相似文献   
56.
In isolated rat adipocytes, epinephrine rapidly stimulates the transport of long chain fatty acid across the plasma membrane. At a concentration of unbound oleate of 0.1 microM ([fatty acid]/[albumin] = 1) and 5 min exposure to the hormone, the minimal effective concentration of epinephrine is 0.03 and the optimal concentration 0.3 microM (0.01 and 0.1 microgram/ml). The stimulated rates are 5-10-fold the basal rate of influx or efflux. The hormone effect is on the transport process specifically as shown by isolation of the product of transport in either direction as unesterified fatty acid and inhibition by the transport inhibitors phloretin and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. This effect of epinephrine on transport coordinates physiologically with lipase activation to bring about fatty acid release from adipose tissue.  相似文献   
57.
Abstract: After the goldfish optic nerve was crushed, the total amount of protein in the nerve decreased by about 45% within 1 week as the axons degenerated, began to recover between 2 and 5 weeks as axonal regeneration occurred, and had returned to nearly normal by 12 weeks. Corresponding changes in the relative amounts of some individual proteins were investigated by separating the proteins by two-dimensional gel electrophoresis and performing a quantitative analysis of the Coomassie Brilliant Blue staining patterns of the gels. In addition, labelling patterns showing incorporation of [3H]proline into individual proteins were examined to differentiate between locally synthesized proteins (presumably produced mainly by the glial cells) and axonal proteins carried by fast or slow axonal transport. Some prominent nerve proteins, ON1 and ON2 (50–55 kD, pI ~6), decreased to almost undetectable levels and then reappeared with a time course corresponding to the changes in total protein content of the nerve. Similar changes were seen in a protein we have designated NF (~130 kD, pI ~5.2). These three proteins, which were labelled in association with slow axonal transport, may be neurofilament constituents. Large decreases following optic nerve crush were also seen in the relative amounts of α- and β-tubulin, which suggests that they are localized mainly in the optic axons rather than the glial cells. Another group of proteins, W2, W3, and W4 (35–45 kD, pI 6.5–7.0), which showed a somewhat slower time course of disappearance and were intensely labelled in the local synthesis pattern, may be associated with myelin. A small number of proteins increased in relative amount following nerve crush. These included some, P1 and P2 (35–40 kD, pIs 6.1–6.2) and NT (~50 kD, pI ~5.5), that appeared to be synthesized by the glial cells. Increases were also seen in one axonal protein, B (~45 kD, pI ~4.5), that is carried by fast axonal transport, as well as in two axonal proteins, HA1 and HA2 (~60 and 65 kD respectively, pIs 4.5–5.0), that are carried mainly by slow axonal transport. Other proteins, including actin, that showed no net changes in relative amount (but presumably changed in absolute amount in direct proportion to the changes in total protein content of the nerve), are apparently distributed in both the neuronal and nonneuronal compartments of the nerve.  相似文献   
58.
The critical statistical parameters of an enzyme-linked immunosorbent assay were determined to enable quantitation of antibody responses in cattle affected with infectious bovine rhinotracheitis. A system of controlling well-to-well variations in optical density reading across a microtitre plate was evolved and dose--response assays were carried out to determine the dilution of serum which gave the greatest discrimination between acute and convalescent sera from an infected animal. Use of a standard serum was studied in further assays. An increase in optical density value of 0.15 was set as a diagnostic criterion for a significantly rising antibody response. This compared well with the conventional criterion of a fourfold rise in virus neutralizing antibody titre.  相似文献   
59.
60.
Synopsis Adult clearnose skates, Raja eglanteria, were captured during the winters of 1981 and 1983, and observed to mate in captivity. Mating and egg depositions take place on the central west coast of Florida from December through mid-May. During copulation the male holds the trailing edge of the female's right or left pectoral fin firmly in his mouth, swings his tail beneath hers and inserts one clasper into the distal end of her reproductive tract. Copulation may last one to four hours during which time sperm pass from the urogenital papilla of the male along the clasper groove to the female. Sperm move cranially to the upper portion of the shell gland where they are stored and remain viable for at least three months. The ovum is fertilized in the shell gland. The egg case bears a prominent projection or horn at each corner. The two posterior ones are shorter and bear tendrils which are covered with a sticky substance that insures attachment to the substrate when the egg is deposited. Fertilized eggs are laid in pairs at intervals ranging from 1 to 13 days (mean of 4.5 ± 2.2 days). As development proceeds within the egg case a plugged slit on the lateral side of each horn opens and permits seawater to wash the developing embryo. Incubation periods for eggs maintained between 20–22°C decrease in duration throughout the egg laying season, ranging from 94 days initially to 77 days for eggs laid later in the spring. At hatching, the anterior end of the egg case ruptures, and the skate emerges abruptly with its pectoral fins rolled dorsally.  相似文献   
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