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61.
Sera from 146 cancer patients at risk for disseminated candidiasis were studied prospectively with immunodiffusion (ID), counterelectrophoresis (CEP), and latex agglutination (LA) tests to determine their diagnostic value in the detection of antibodies to theCandida species. Serial serum samples, cultures, and clinical data were obtained after a malignancy was diagnosed. Patients were classified into three groups (I, II, and III) on the basis of cultural, histological, and clinical evidence for superficial (Group I) versus disseminated (Group III)Candida infection. Thirty-two of 78 patients (41%) in Group I had positive ID, CEP, and LA titers. In Group II, those patients lacking histological confirmation of disseminated infection, 16 of 18 (89%) had positive titers. Thirty-six of 50 (72%) in Group III were positive by all three tests. Heavy colonization of the gastrointestinal tract, without evidence of tissue invasion, produced positive test results. Negative serologic tests were encountered in immunosuppressed patients with rapidly progressive candidiasis.C. krusei infections produced specific antibody titers detected by the homologous antigen but not byC. albicans antigen. Stable or decreasing LA titers were correlated with clinical improvement in patients receiving effective antifungal therapy.  相似文献   
62.
Acylated crude papain has been shown to exert stereoselective behavior toward racemic hydrazides devoid of an amino acid residue, namely, (RS)-mandelic and (RS)-atrolactic hydrazides. These hydrazides functioned as nucleophiles to yield N1,N2-diacylhydrazines. Several achiral acylating agents for the enzyme were chosen, including Z-glycine, BOC-glycine, AOC-glycine, and hippuric acid. With the exception of hippuric acid as the acylating agent, the reaction product, in every instance for these achiral hydrazides, consisted of an excess of the (+)-N1,N2-diacylhydrazine. The relative rates of product formation for the mandelic hydrazides were considerably greater than for corresponding reactions with racemic atrolactic hydrazide. When chiral Z-l-alanine was employed to acylate crude papain, the stereoselective action was most pronounced, with the formation of a mixture of diastereoisomers consisting of 73% N1-(Z-l-alanyl)-N2-[(R)-mandelyl]hydrazine. The relative reactivities for the electrophiles was Z-l-alanine ? Z-glycine ? hippuric acid ? AOC-glycine > BOC-glycine. The hydrazides of (R)-, (S)-mandelic, and (RS)-atrolactic acids were prepared by conversion of the corresponding acids to their esters by means of a catalytic dehydrating agent and subsequent treatment with a methanolic solution of hydrazine.  相似文献   
63.
Hydrazides of five N-acylamino acids have been used alone as substrates for papain catalysis to yield N1,N2-diacylhydrazines. With the exception of N-(benzyloxycarbonyl)(Z)- -alanine hydrazide, they were very effective as both acylating agents of the enzyme and nucleophiles in attacking the enzyme-substrate intermediate. Although Z- -alanine hydrazide was a minimal acylating agent, it was a satisfactory nucleophile. The most favorable reaction involved Z- -alanine hydrazide in producing N1,N2-bis(Z- -alanyl)hydrazine. When Z- -alanine hydrazide was the substrate, this same chiral diacylhydrazine was formed along with meso N1-(Z- -alanyl)-N2-(Z- -alanyl)hydrazine. For the acylation step, the enzyme displayed powerful, essentially stereospecific, bias toward the enantiomer. Once the thioester intermediate was formed, little preference was detected for attack by the enantiomers as nucleophiles. The most direct procedure for synthesis of substrates was conversion of Z-amino acids to their esters by means of dry HCl in an absolute alcohol. Treatment with hydrazine produced the hydrazides in excellent yield.  相似文献   
64.
The effect of collection technique, anticoagulant, pH, glucose, and temperature on in vitro granulocyte function were studied after 24 hr of storage in the liquid state. Collection by CL did not adversely affect granulocyte function, however, cells collected by FL had accelerated loss of bactericidal activity and chemotactic response. Citrate anticoagulants provided better maintenance of bacteridical activity, NBT reduction, and chemotactic response than heparin, EDTA, and ion-exchange anticoagulants. Chemiluminescence was well maintained when the initial pH of the preservative solution (CPD plasma) was between 6.5 and 8.0 but maintenance of chemotaxis required pH of 7.0–7.5. Glucose concentrations of 80–1000 mg/dl provided adequate maintenance of chemiluminescence and chemotaxis. Bacterial killing was well maintained by storage at either 1–6 or 20–24 °C. Storage at 1–6 °C caused decreased chemotaxis, decreased ability of granulocytes to adhere and spread on a foreign surface, and a decreased intravascular recovery and shortened half-life after transfusion. Although short-term liquid storage may be practical, at present, granulocytes should be transfused as soon as possible after collection.  相似文献   
65.
Mild sonication was used to obtain single cell suspensions of Paracoccidioides brasiliensis. These cells were intact by microscopic criteria. Direct cell counts in a given inoculum and colony formation on various media were used to determine plating efficiency. Sonicated and nonsonicated cell suspensions were used to study plating efficiency and to estimate viability by means of vital dyes. Methylene blue, Erythrosin B, and Janus green were unreliable when used with P. brasiliensis, but vital dyes were accurate when tested with Candida albicans.Acridine orange gave more meaningful results of viability. Estimates of viability, however, changed significantly as a result of relatively minor alterations in the composition of the suspending medium.In initial experiments, the plating efficiency of P. brasiliensis was dismally low. It descended abruptly with increasing dilution of inoculum. Efficiency was much improved if horse serum was added to brain heart infusion plates or if glucose glycine yeast extract (GGY) plates were incubated at room temperature and mycelial colonies were counted. With the technique we report, current plating efficiency of sonicated suspensions is of the order of 25 %. Our results and procedures have an important bearing upon those studies concerned with in vitro killing of P. brasiliensis in suspensions or with isolating this fungus from clinical or environmental specimens.  相似文献   
66.
Two strains of Histoplasma capsulatum were required to prepare maximum yields of H and of M antigen from histoplasmin. The antigens were separated and partially purified by a series of procedures yielding an overall recovery of 70 to 90% of the individual antigens. Stable products suitable for use as reference products were obtained when the final purification step employed DEAE-cellulose with phosphate buffer elution at increasing molarity and decreasing pH. A final step of purification of each antigen with slab acrylamide gel electrophoresis gave products which were highly reactive and specific in a variety of serological tests with sera from persons with proven cases of histoplasmosis and with natural infections of heterologous deep mycoses. These antigens were maximally active at concentrations of 2 to 16 g protein in the complement fixation, capillary precipitin, microimmunodiffusion, or immunoelectrophoresis tests; 0.5 g gave a maximum delayed cutaneous hypersensitivity reaction in homologously infected animals and caused no appreciable reaction in control animals. Although these antigens appeared to be specific when tested with sera from persons with natural infections, the M and H antigens demonstrated the presence of an additional antigen reacting with sera of rabbits immunized with cell membrane and cell particulate fractions of Blastomyces dermatitidis. After purification by electrophoresis, both the H and M antigens of some preparations showed some decomposition and loss of reactivity after storage at 5 C for more than six months. The overall results suggest that the purified H and M antigens of Heiner (12) have multiple serological reactivity and may function in precipitin reactions, complementfixing reactions, hemagglutination of formalin-fixed goose red blood cells, and as antigens for delayed cutaneous tests.  相似文献   
67.
Optimal conditions for the rhesus monkey micro mixed lymphocyte system with multiple automated harvesting of samples were evaluated. Parameters studied were cell concentration, length of culture period, methods of inactivation of cell populations, supplementation of media, type of culture plates, and changes in the reactivity of cells from individual animals over an extended time period. This work was supported in part by Portland Veterans Administration Hospital, Portland, Oregon, and the General Research Support Branch of the U.S. Public Health Service Grant RR00163, the Bureau of Medicine and Surgery, Navy Department, Work Unit No. M4318. 01.007ABG2. The opinions or assertions contained herein are the private ones of the authors and are not to be construed as official or reflecting the views of the U.S. Navy Department or the Naval service at large. The animals used in this study were handled in accordance with the provisions of Public Law 89–54 as amended by Public Law 91–579, “Animal Welfare Act of 1970,” and the principles outlined in the “Guide for the Care of Laboratory Animals,” U.S. Department of Health, Education, and Welfare Publication No. (NIH) 73-23.  相似文献   
68.
Sigrid M. Klein  Leo P. Vernon 《BBA》1977,459(3):364-375
The use of Triton X-100 to solubilize membrane fragments from Anabaena flos-aquae in conjunction with DEAE cellulose chromatography allows the separation of three green fractions. Fraction 1 is detergent-solubilized chlorophyll, and Fraction 2 contains one polypeptide in the 15 kdalton area. Fraction 3, which contains most of the chlorophyll and shows P-700 and photosystem I activity, shows by SDS gel electrophoresis varying polypeptide profiles which reflect the presence of four fundamental bands as well as varying amounts of other polypeptides which appear to be aggregates containing the 15 kdalton polypeptide. The four fundamental bands are designated Band I at 120, Band II at 52, Band III at 46, and Band IV at 15 kdaltons. Band I obtained using 0.1% SDS contains chlorophyll and P-700 associated with it. When this band is cut out and rerun, the 120 kdalton band is lost, but significant increases occur in the intensities of Bands II, III, and IV as well as other polypeptides in the 20–30 kdalton range.The use of 1% Triton X-100 coupled with sucrose density gradient centrifugation allows the separation of three green bands at 10, 25 and 40% sucrose. The 10% layer contains a major polypeptide which appears to be Band IV. The 25 and 40% layers show essentially similar polypeptide profiles, resembling Fraction 3 in this regard, except that the 40% layer shows a marked decrease in Band III. Treatment of the material layering at the 40% sucrose level with a higher (4%) concentration of Triton X-100 causes a loss (disaggregation) of the polypeptides occurring in the 60–80 kdalton region and an increase in the lower molecular weight polypeptides. Thus, aggregation of the lower molecular weight polypeptides accounts for the variability seen in the electrophoresis patterns. Possible relations of the principal polypeptides to the known photochemical functions in the original membrane are discussed.  相似文献   
69.
Triethyltin (TET) stimulated the basal respiration of Escherichia coli K-12 membrane vesicles in chloride (Cl-) medium but it had little effect on respiration in sulphate (SO4(2-)) medium. Since this uncoupling activity was Cl- dependent it was attributed to the Cl-/hydroxide (OH-) exchange reaction known to be mediated by TET [1,2]. TET inhibited the oxidation of succinate by intact E. coli in both Cl- and SO4(2-) medium, but at the same concentration of TET, inhibition was always more extensive in Cl- than SO4(2-) medium. In Cl- medium uncoupling in membrane vesicles and inhibition of succinate oxidation in intact bacteria occurred over the same concentration range and it appeared that the same mechanism, i.e. Cl-/OH- exchange, was responsible for both effects. Inhibition of succinate oxidation in SO4(2-) medium was not substantial until the concentration of TET was greater than 10(-5) M. Although the nature of this inhibition could not be determined by experiments with membrane vesicles indirect evidence from growth experiments indicated that it was due to impairment of oxidative phosphorylation. The relationship between these biochemical findings and the bacteriocidal action of TET was examined by using various concentrations of anion and substrate in the growth medium. Growth was inhibited in media containing either Cl- or SO4(2-) as the main anion but at a particular concentration of TET, inhibition was greater in Cl- medium. Growth was also inhibited to a greater extent in succinate than glucose medium. Furthermore in either Cl- or SO4(2-) glucose medium, lactic acid production increased as the concentration of TET was increased. These findings imply that the bacteriocidal action of TET is related to its effect(s) on oxidative phosphorylation.  相似文献   
70.
Summary Cells of embryos carrying a lethal nucleolar mutation have been maintained in vitro for extended periods of time. Normally these mutants live only 9 to 12 days after fertilization but their cells in culture will survive for more than 3 months. The extent of ribosomal RNA (rRNA) synthesis was determined in primary cultures prepared from normal embryos and nucleolar mutants having different numbers of ribosomal RNA genes. We found that the accumulation of radioactivity into rRNA for normal and mutant embryos was similar in vivo and in vitro. In primary cultures of normal embryos which have two nucleoli per cell and mutant embryos which have only one nucleolus per cell, the incorporation of radio-activity into rRNA was similar even though the normal cells have twice as many rRNA genes. Thus the mechanism which regulates dosage compensation of the rRNA genes operates both in vivo and in vitro. This work was supported by Grant GB38651 from the National Science Foundation.  相似文献   
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