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81.
Three cases of adenocarcinoma of the stomach, two in situ and one superficially invasive, and one of superficially invasive squamous-cell carcinoma of the esophagus are presented to illustrate the problems encountered in the diagnosis of early lesions of the upper gastrointestinal (GI) tract and the contribution that cytodiagnosis can make. The symptomology and roentgenographic findings in these cases were largely nonspecific. While endoscopic biopsies were repeatedly negative in three of the four cases, endoscopic brushing cytology consistently indicated the presence of a malignancy. Surgery was finally performed on the basis of the cytologic findings, confirming the presence of early malignancy. The cytologic findings, with histologic correlations, are presented in an effort to define some specific criteria for the diagnosis of early malignancy of the upper GI tract. 相似文献
82.
C R Mendelson E E Wright C T Evans J C Porter E R Simpson 《Archives of biochemistry and biophysics》1985,243(2):480-491
Aromatase cytochrome P-450 (P-450AROM) was partially purified from human placental microsomes by hydrophobic affinity chromatography using Phenyl-Sepharose and ion-exchange chromatography on DEAE-cellulose. The resulting preparation had a specific activity of 2 nmol/mg protein with respect to cytochrome P-450 content and displayed a type I difference spectrum upon addition of the substrate androstenedione. When the cytochrome P-450-enriched fractions were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and stained with Coomassie blue, there was an enrichment of two proteins having apparent molecular weights of 50,000 and 55,000. The bands containing these proteins were removed from unstained polyacrylamide gels and injected separately or together into three rabbits. An aliquot of the serum or an immunoglobulin (IgG) fraction prepared from the serum of the rabbit injected with the 55-kDa band or with both the 50- and 55-kDa bands inhibited aromatase activity of human placental microsomes by 80%; this IgG had no effect on 17 alpha-hydroxylase or 21-hydroxylase activities of human fetal adrenal microsomes. In contrast, the serum of the rabbit injected with the 50-kDa band had little capacity to inhibit placental aromatase activity. By immunoblot analysis, it was found that the IgG from the serum of the rabbit immunized with the 55-kDa protein bound specifically to a protein of 55 kDa in human placental microsomes. Monoclonal antibodies were prepared from a hybridoma cell line derived from the spleen cells of mice immunized against the 55-kDa protein. The monoclonal IgG was covalently linked to a Sepharose 4B column and was used for immunoaffinity chromatography of cytochrome P-450AROM. The finding that cytochrome P-450 and the 55-kDa protein were selectively retained by the affinity column and eluted with NaCl (2 M) and glycine (0.2 M, pH 3.0) and that this fraction contained aromatase activity upon reconstitution with purified NADPH-cytochrome P-450 reductase and phospholipid, is indicative that the 55-kDa protein is indeed cytochrome P-450AROM. These findings are also indicative that both the monoclonal and polyclonal IgGs are specific for human cytochrome P-450AROM. 相似文献
83.
Binding and internalization of heparin by vascular smooth muscle cells 总被引:13,自引:0,他引:13
J J Castellot K Wong B Herman R L Hoover D F Albertini T C Wright B L Caleb M J Karnovsky 《Journal of cellular physiology》1985,124(1):13-20
Previous work from our laboratory has demonstrated that heparin specifically inhibits the proliferation of vascular smooth muscle cells in vivo and in vitro. In this paper, we examine the binding and mode of internalization of heparin by smooth muscle cells. For these studies, radiolabeled and fluoresceinated (FITC) heparin probes were synthesized that retained their antiproliferative capacity. Binding of 3H-heparin to these cells occurs via specific, high-affinity binding sites (Kd = 10(-9) M, 100,000 binding sites per cell). Approximately 80% of the heparin bound to the cell surface was shed into the culture medium within 2 hr. The heparin that was left on the cell surface was internalized with biphasic kinetics. Approximately 50% of the bound material was internalized within 2 hr. After this initial rapid uptake, the rate slowed substantially, with the remaining heparin requiring 1-2 days to be internalized. Binding and uptake of FITC heparin was monitored using video image intensification fluorescence microscopy. When smooth muscle cells were exposed to FITC heparin at 4 degrees C, a diffuse surface staining pattern was observed. After warming the cells to 37 degrees C, intensely fluorescent vesicles were seen superimposed over the diffuse surface staining within 2 min. After 15 min at 37 degrees C, numerous large punctate vesicles were seen inside the cell. After 2 hr these vesicles had concentrated in the perinuclear region. This pattern of uptake, when considered along with the presence of specific, high-affinity binding sites and the initial rapid uptake of 3H-heparin, suggests that heparin enters smooth muscle cells by both receptor-mediated and other endocytic pathways. 相似文献
84.
The effect of starvation on RNA: DNA ratios and growth of larval striped bass, Morone saxatalis 总被引:1,自引:0,他引:1
Hatchery reared larval striped bass, Morone saxatilis , 8-days-post-hatching were subjected to various feeding/starvation regimes over a period of 14 days.
Batches of larvae from each treatment were sampled over the 14-day period and subdivided for determination of notochord length and RNA:DNA ratio. The best growth was found in fully fed F1000 larvae (exposed to 1000 Artermia nauplii l−1 ), which reached 8.2 mm after 11 days and 9.6 mm after 14 days. Starved animals after 11 days had notochord lengths of 4.9 mm. Growth curves from feeding-delayed larvae indicated that animals fed after up to 5 days starvation were capable of complete recovery. F100 larvae (exposed to 100 Anemia nauplii 1−l ) had a slower growth rate than F1000 larvae, reaching a notochord length of 7.3 mm after 14 days. RNA:DNA ratios over time closely followed notochord growth curves, with clear differences between starved, F100 and F1000 larvae being established after only 2 days. Equilibrium RNA:DNA ratios of 3.0 and 2.25 were established in F1000 and F100 larvae, respectively, 6.8 days after the beginning of the experiment. The average lag time between a change from the starved to the fed condition and a change in RNA:DNA ratio as determined by the divergence of the nucleic acid curve from the starved condition was 0.66 days.
In treatments where starvation followed various periods of feeding, larvae regressed in notochord length such that the final length at 14 days reflected the degree of feeding. RNA:DNA ratios in these animals again closely followed growth curves with a lag time of 0.81 days.
It was concluded that RNA:DNA ratios provided very accurate indices of growth in striped bass larvae which were highly sensitive to feeding status. 相似文献
Batches of larvae from each treatment were sampled over the 14-day period and subdivided for determination of notochord length and RNA:DNA ratio. The best growth was found in fully fed F1000 larvae (exposed to 1000 Artermia nauplii l
In treatments where starvation followed various periods of feeding, larvae regressed in notochord length such that the final length at 14 days reflected the degree of feeding. RNA:DNA ratios in these animals again closely followed growth curves with a lag time of 0.81 days.
It was concluded that RNA:DNA ratios provided very accurate indices of growth in striped bass larvae which were highly sensitive to feeding status. 相似文献
85.
Investigation of the instability of plasmids directing the expression of Met-prochymosin in Escherichia coli 总被引:4,自引:0,他引:4
C A Caulcott G Lilley E M Wright M K Robinson G T Yarranton 《Journal of general microbiology》1985,131(12):3355-3365
The causes of the instability of a multicopy plasmid, pCT70, which directs the expression of calf prochymosin in Escherichia coli, were investigated. Plasmid pAT153 and its derivative, pCT54, were stable for more than 90 generations in continuous culture with glucose limitation. The multicopy plasmid pCT66, which expressed very low levels of prochymosin due to poor translational efficiency, and low copy number plasmids which efficiently expressed the prochymosin gene, were also stable. These results indicated that high level translation of the recombinant gene was the cause of the instability of pCT70. The maximum specific growth rate of E. coli(pCT70) was reduced by 30% compared with E. coli(pCT66). To fulfil the requirements of a production system, a dual origin plasmid with controllable copy number was developed. Both this plasmid (pMG165) and a derivative which contained the prochymosin gene (pMG168) were stable when maintained at low copy number. When the copy number of plasmid pMG168 was increased by putting replication under the control of the lambda PR promoter and the cI857 temperature sensitive repressor, expression of prochymosin was achieved. This strategy enables large-scale production of prochymosin without the need for antibiotic selection or other methods of preventing plasmid loss. 相似文献
86.
Androst-4-en-3-one analogs incorporating a trimethylsilyl or a trimethylsilylmethyl group at C-1, C-2 or C-19 were prepared and evaluated as inhibitors of aromatase. Only 10-[1-hydroxy-2-(trimethylsilyl)ethyl]estr-4-ene-3,17-dione inhibited human placental aromatase. Enzyme kinetic analysis revealed competitive inhibition [apparent dissociation constant (Ki) of 562 +/- 12 nM] associated with marginal time-dependent inhibition. 相似文献
87.
Stephen H. Wright 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1985,156(2):259-267
Summary The epidermal tissues of marine mussels can accumulate amino acids from surrounding sea water. In the present study, gill tissue isolated from the California coastal mussel,Mytilus californianus, was used in conjunction with intact, actively pumping mussels to study epidermal transport processes. There appeared to be at least four pathways for this uptake: i) a -neutral pathway which transports taurine; ii) an -acidic pathway specific for substrates such as aspartate; iii) an -neutral pathway having a general specificity for this class of compound, but which also accepts the basic amino acid, lysine; and iv) a second -neutral pathway, also of broad specificity, capable of accepting the imino acid, proline, as a substrate. Replacement of Na in sea water with choline reduced uptake of leucine, taurine, aspartate, and proline by more than 95%, and reduced lysine uptake by 75%, suggesting that Na-independent pathways play no significant role in epidermal transport in the gill. Isolated gill tissue was used to estimate the maximum transport capacities (J
max's) of the pathways, which ranged from approximately 5 to 25 mol/(g·hr). Apparent Michaelis constants (K
t
*'s) of the epidermal transporters were estimated using a convection-diffusion model introduced previously (Wright and Secomb, Am J Physiol 247:R346–R355, 1984). TheseK
t
*'s ranged from 1 to 5 M. The characteristics of the epidermal transporters are such that they can play a significant role in both animal nutrition and in the reacumulation of endogenous amino acids lost from surface cells through passive diffusion.Abbreviation ASW
artificial sea water 相似文献
88.
The DNase I digestion kinetics of DNA in isolated nuclei (from HeLa or murine mammary carcinoma, 67 cells) were assayed flow cytometrically by measuring the changes in ethidium bromide (EtBr) fluorescence following various digestion time intervals. The DNase I digestion curve was characterized by an initial 25-30% increase in fluorescence upon addition of the enzyme, a rapid reduction in fluorescence to approximately 50-55% in 30 minutes, and a limit digest of 45-50% beyond 45 minutes. Throughout digestion, the DNA histogram retained its characteristic bimodal shape, showing that histogram rearrangement was not responsible for the changes in EtBr fluorescence. Irradiation with 5 X 10(6) rads (137Cs-gamma-rays) or exposure to 50 mM EDTA caused an increase in EtBr fluorescence similar to that caused by DNase I, suggesting that DNA nicking and/or chromatin loosening were responsible for this increase. Residual DNA assayed by the solubilization of 14C-TdR (thymidine)-labeled DNA indicated a similar kinetic pattern without the initial increase. However, at the limit digest, the fraction of DNA remaining trichloroacetic acid (TCA) insoluble (10%) was smaller than that measured by loss of EtBr fluorescence (50% of initial, 40% of maximum). Part of this difference was due to the presence of TCA soluble DNA trapped within the nuclear matrix (15-20%). This trapped DNA was released when the digested nuclei were exposed to 0.5-1.0 M NaCl just prior to EtBr staining. Exposure of HeLa cells to three agents that are believed to cause changes in chromatin structure resulted in alterations in the DNase I digestion kinetics measured flow cytometrically.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
89.
90.
Joseph M. Wright 《Theriogenology》1985,23(1):17-29
Bovine embryos were frozen commercially in clear double length cc French straws with the wick and powder plug in the center of the straw. One-half of the double length straw serves as a handle and contains a color coded cc straw around which an adhesive backed label has been applied. After plunging into liquid nitrogen, straws are transferred into goblets on canes while under liquid nitrogen. The straws are stored in the liquid phase of a nitrogen tank and canes containing straws are not transferred from one container to another unless the goblet containing the straws is full of liquid nitrogen.Embryos held for longer than 4 hours after collection prior to freezing showed a steady decline in pregnancy rate related to the length of time held prior to freezing. The percentage of embryos thawed and then evaluated as being transferrable was related to the quality of the embryos prior to freeze (Grade 1–93.6%, Grade 2–87.0%, Grade 3–63.8%). There was no statistical difference in pregnancy rates obtained from prefreeze Grade 1 embryos when comparing advanced blastocysts (45.2%), blastocysts (38.7%), early blastoclyst (43.1%) and advanced morula (41.6%). 相似文献