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21.
Summary Microsomal and soluble fractions of Pleurotus pulmonarius exhibited a reduced carbon monoxide difference spectrum with P450 maxima at 448nm and 450–452nm respectively. Substrate induced Type I spectra were observed on addition of benzo(a)pyrene to both fractions. Benzo(a)pyrene hydroxylation was measured using the aryl hydrocarbon hydroxylase assay and was observed to be P450 dependent as indicated by carbon monoxide inhibition together with the substrate binding characteristics. The activity of the fractions were observed to give Km of 200mM and 660mM and Vmax of 1.25 nmol/min/nmol P450 and 0.57 nmol/min/nmol P450 for the microsomal and cytosolic fractions respectively. 相似文献
22.
S. A. Jenkins J. N. Baxter M. Critchley A. N. Kingsnorth C. A. Makin S. Ellenbogen J. S. Grime J. G. Love R. Sutton 《BMJ (Clinical research ed.)》1997,315(7119):1338-1341
OBJECTIVE: To assess the efficacy of long term octreotide as adjuvant treatment to programmed endoscopic sclerotherapy after acute variceal haemorrhage in cirrhotic portal hypertension. DESIGN: Randomised clinical trial. SETTING: University hospital. SUBJECTS: 32 patients with cirrhotic portal hypertension. INTERVENTIONS: Programmed injection sclerotherapy with subcutaneous octreotide 50 micrograms twice daily for 6 months, or programmed injection sclerotherapy alone. MAIN OUTCOME MEASURES: Episodes of recurrent variceal bleeding and survival. RESULTS: Significantly fewer patients receiving combined octreotide and sclerotherapy had episodes of recurrent variceal bleeding compared with patients given sclerotherapy alone (1/16 v 7/16; P = 0.037, Fisher''s exact test), and their survival was significantly improved (P < 0.02, log rank test); this improvement was maintained for 12 months after the end of the study. Combined treatment also resulted in a sustained decrease in portal pressure (median decrease -6.0 mm Hg, interquartile range -10 to -4.75 mm Hg, P = 0.0002) compared with sclerotherapy alone (median increase 1.5 mm Hg, interquartile range 0.25 to 3.25 mm Hg), as well as a significant improvement in liver function as assessed by plasma concentrations of bilirubin, albumin, and alanine aminotransferase and by hepatocyte metabolism of aminopyrine labelled with carbon-14. CONCLUSION: Long term octreotide may be a valuable adjuvant to endoscopic sclerotherapy for acute variceal haemorrhage in cirrhotic portal hypertension. 相似文献
23.
Impact of Growth in Benzoate and m-Toluate Liquid Media on Culturability of Pseudomonas putida on Benzoate and m-Toluate Plates 总被引:1,自引:0,他引:1 下载免费PDF全文
Pseudomonas putida grown in continuous culture on benzoate or m-toluate lost the ability to grow on benzoate or m-toluate plates. A similar effect was not seen with a glucose continuous culture. Cells carrying and expressing a TOL plasmid rapidly lost their ability to grow on benzoate solid medium. 相似文献
24.
One hundred and eighteen patients with normal gastrointestinal function were randomly allocated to one of three feeding regimens in a double blind study to determine the relation between the tonicity of the diet and gastrointestinal side effects related to the diet and to evaluate the efficacy of "starter" regimens in reducing gastrointestinal side effects during enteral nutrition. Patients received a hypertonic diet with an osmolality of 430 mmol (mosmol)/kg (group 1), the same diet but with the osmolality increasing from 145 to 430 mmol/kg over the first four days (group 2), or an isotonic diet (300 mmol/kg) (group 3). All diets were prepared aseptically and administered by 24 hour nasogastric infusion. The mean daily nitrogen intake in group 1 was significantly greater (p less than 0.05) than that in both groups 2 and 3, and the mean overall daily nitrogen balance was significantly better (p less than 0.05) in group 1 than groups 2 and 3. The incidence of side effects related to the diet was similar in all three groups, but diarrhoea was significantly (p less than 0.001) associated with concurrent treatment with antibiotics. These findings show that undiluted hypertonic diet results in significantly better nitrogen intake and balance, that starter regimens reduce nutrient intake but not symptoms, and that diarrhoea is significantly related to treatment with antibiotics and not to administration of an undiluted hypertonic polymeric diet. 相似文献
25.
E. coli cells were reacted with TNBS in bicarbonate-NaCl buffer, pH 8.5 (buffer A) and in phosphate-NaCl buffer, pH 7.0 (buffer B). In buffer A, DNP-GPE is the major product when FDNB is used. DNP-PE and DNP-LPE are formed in lesser amounts. Phospholipase A activity is high in buffer A. When TNBS is used, the labeling of the lipid components is less than with FDNB and more TNP-PE is formed relative to TNP-GPE. This data suggests that the phospholipases which are located primarily on the outer L-membrane of the cell wall act to a lesser extent on TNP-PE than on DNP-PE. E. coli cells were prelabeled with TNBS and FDNB in buffer A, washed and incubated in buffer A. The endogenous labeled DNP-PE gradually decreased with time with a concomitant increase in DNP-LPE and DNP-GPE due to phospholipase A activity. In contrast, the endogenous labeled TNP-PE also decreased with time as did the endogenous labeled TNP-LPE but a new orange lipid was produced. This lipid is believed to be a derivative of TNP-PE in which one of the nitro groups has been reduced to an amino group by nitroreductase. E. coli cells were prelabeled with TNBS and FDNB in buffer A, washed and incubated in buffer B. Under these conditions with both TNBS and FDNB there is an increase in TNP-PE and DNP-PE with a concomitant decrease in TNP-LPE, TNP-GPE, DNP-LPE and DNP-GPE. These results show that at neutral pH acylation occurs to regenerate TNP-PE and DNP-PE. E. coli cells were incubated with exogenous DNP-GPE or TNP-GPE in buffer A. The DNP-GPE and TNP-GPE were rapidly hydrolyzed by a phosphodiesterase to DNP-ethanolamine and TNP-ethanolamine. An orange derivative was formed which was provisionally identified as a derivative of DNP-ethanolamine or TNP-ethanolamine in which a nitro group has been reduced to an amino group by nitroreductase. The phospholipases and acylating enzymes present in the cell wall of E. coli are active on the dinitrophenyl and trinitrophenyl derivatives of PE and LPE and may act in concert to model and repair the plasma membrane. 相似文献
26.
T M Doherty B T B?ckstr?m R L Prestidge S G Love D R Harding J D Watson 《Journal of immunology (Baltimore, Md. : 1950)》1991,146(6):1934-1940
Antibody responses to the 18-kDa protein of Mycobacterium leprae have been analyzed in different strains of mice. High, intermediate, and low responder strains have been identified and these response patterns show clear linkage to genes encoded in the H-2 complex. Three peptides, residues 1-50, 51-100, and 101-148 have been synthesized, as well as a series of 20-mer peptides, which span the entire 18-kDa protein. Repeated immunization of different strains of mice with the 18-kDa protein resulted in IgG responses to epitopes found on all three synthetic peptides. Immunization of BALB/cJ and B10.BR mice, two high responder strains, with 18-kDa protein resulted in high levels of IgG antibody to epitopes found on peptides 1-20, 16-35, 31-50, 46-65, and 76-95. B10.BR mice also contained IgG that bound peptide 61-80 and BALB/cJ mice produced IgG that bound peptide 91-110. Although B10.BR mice produced IgG that bound the 50-mer peptide 101-148, this IgG was not detected by binding to peptides 91-110, 106-125, 121-140, and 131-148. Immunization of B10.BR mice with individual overlapping 20-mer peptides as Ag revealed that peptides 1-20, 16-35, 31-50, and 76-95 elicited high titers of IgG that bound both the immunizing peptide as well as 18-kDa protein. As these peptides induce antibody synthesis they must contain both B cell and T cell epitopes. By contrast, immunization of BALB/cJ mice with the same 20-mer peptides, all of which contain B cell epitopes for this strain, failed to elicit IgG responses with one exception. Peptide 91-110 induced IgG that bound peptide 91-110, but not the intact 18-kDa protein. We conclude that peptides 1-20, 16-35, 31-50, and 76-95 either lack T cell epitopes for BALB/cJ mice, or activate different T cell subpopulations in the two strains. We suggest that the induction of IgG responses to small peptide Ag is an in vivo assay of the activity of Th2 cell subpopulations. 相似文献
27.
We report methods to generate protoplasts, to regenerate mycelia, and to transform Micromonospora echinospora. This actinomycete produces the unusual antitumor antibiotics, the calicheamicins. These protocols may be applied to other actinomycetes that have been difficult to transform. These methods also may facilitate the cloning of calicheamicin biosynthetic genes by genetic complementation. 相似文献
28.
Sequences of junction fragments in the deletion-prone region of the dystrophin gene 总被引:15,自引:0,他引:15
D R Love S B England A Speer R F Marsden J F Bloomfield A L Roche G S Cross R C Mountford T J Smith K E Davies 《Genomics》1991,10(1):57-67
The Duchenne muscular dystrophy locus is remarkable in that it shows a high mutation rate and the majority of mutations found are deletions. These deletions are generated as meiotic as well as mitotic events and occur preferentially in the central region of the gene. Nothing is known so far about the mechanisms involved. This paper reports the first sequencing of deletion junctions in the dystrophin gene. The data from a study of two patients with deletions in the central region of dystrophin show the breakpoints to lie in regions of introns in which stretches of dA-dT are seen. The relationship between these observations and possible mechanisms for the mutations is discussed. 相似文献
29.
30.