摘要:

ABSTRACTBlastocrithidia triatomae, a species very resistant to cultivation in conventional media, was successfully grown in association with cultured lepidopteran cells. The cultured flagellates were identical to those in the insect host, including the presence of characteristic cysts on the flagellum. Growth rate was better for cultures in theHeliothis zeamedium than in IPL‐45 medium or modified McConnell's mediu

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02814.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTA virulent strain ofBabesia bovis(“L” strain) was rendered avirulent by irradiation with 35 krads with a γ source. Another virulent strain ofB. bovis (“C” strain) was made avirulent by rapid blood passage through 12 splenectomised calves. Both the parent virulent and their respective avirulent strains were injected into susceptible cattle. A nonfatal disease was observed in those intact cattle that had avirulent parasites; however, a fatal disease was produced in those animals that had received virulent parasites and in splenectomised calves that had received avirulent parasites. Blood kinin levels rose and plasma kininogen levels fell significantly in those animals infected with both virulent strains. Nonsignificant changes occurred with these parameters in animals infected with avirulent parasites. Preparations of disrupted parasites were obtained from the four parasite populations. Both virulent strains contained high levels of protease. The avirulent forms contained insignificant amounts. As parasite doubling times and maximum parasitaemias were the same for all four parasite populations, we conclude that these enzymes are not obligatory for parasite multiplication in the vertebrate host. Their role in producing pathological changes in the host is d

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02815.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTThe species‐specific lethal factor obtained fromAmoeba indica, a freeliving mononucleate amoeba, can be partially purified by differential centrifugation, gel exclusion chromatography, and elution from Cibacron blue‐agarose. The factor is unstable in the partially purified form, but activity is correlated with a heat‐labile protein having an apparent molecular weight of 186,000. The factor causes inhibition of division and death when injected intoA. proteus. Purification of the lethal factor indicates that aggregation of the factor with amoebal proteins is not a hindrance to further investigation. The natural role of the factor is disc

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02816.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTLeptomonas lactosovoransn. sp. is described from the gut of the reduviid hemipteranZelurus martinsi. It can be grown in a defined medium. The requirements for amino acids, vitamins, purine, and heme were similar to those established forCrithida fasciculata. Growth is stimulated by aeration. Generation time is longer than for any other insect trypanosomatid described; its utilization of lactose as a carbon source is a unique feature among trypanosomatids.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02817.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

ABSTRACTCell free preparations ofTetrahymena thermophilacontain an enzyme that catalyzes the direct desaturation of stearoyl CoA to octadecenoic acid. The enzyme is associated with the microsomal fraction of the ciliate. Substrate for the enzyme consists of either free stearic acid or stearoyl CoA. Both ATP and CoA are required when free stearate is the substrate and are also highly stimulatory when stearoyl CoA is the substrate. With stearoyl CoA as the substrate, either NADH or NADPH are required for desaturase activity. In the presence of ATP and CoA, either NAD or NADP can replace NADH and NADPH. Desaturase activity is optimal when the enzyme is incubated at a pH of 7.2 and a temperature of 30–35°C. Highest levels of the stearoyl CoA desaturase are found in stationary phase ciliates grown at 35

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1981.tb02818.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY