A Burkitt-lymphoma variant translocation (2p-; 8q+) in a patient with ALL,L3 (Burkitt type)

Summary A patient with acute lymphoblastic leukemia (ALL) whose cells had L3 (Burkitt-type) morphology was found to have a variant translocation t(2;8)(p13;q24), that has been reported only in Burkitt lymphomas. This observation provides additional evidence for a close association of particular karyotypic abnormalities with both Burkitt-type ALL and Burkitt lymphoma.     

Synthesis of desmosterol and epidesmosterol from hyodeoxycholic acid

A new synthesis of desmosterol was described using hyodeoxycholic acid (3,6-dihydroxy-5β-cholanic acid) as a starting material. Epidesmosterol (3-hydroxycholesta-5,24-diene) was also synthesized for the first time from the same starting material.     

Microbiological studies of Tokyo Bay

The generic composition of the heterotrophic bacterial population of Tokyo Bay, which is now highly polluted and eutrophic, was compared with that of the adjacent, less polluted regions of Sagami Bay and Suruga Bay. Members of Vibrionaceae predominated in the bacterial flora of seawater and zooplankton samples from Sagami Bay, Suruga Bay, and the mouth of Tokyo Bay. However,Vibrio spp. formed only a small proportion of the bacterial population of the water and sediment samples from the inner Tokyo Bay; there the Gram-negative, nonmotile, nonpigmented bacteria, which were tentatively identified asAcinetobacter, were predominant. The result of experiments, in which seawater samples from Tokyo Bay were incubated under various experimental conditions, indicated that two significant factors apparently control the growth ofVibrio spp. in seawater; (1) a direct antagonism betweenVibrios and phytoplankton undergoing rapid growth, and (2) a limiting organic nutrient forvibrios.     

Cis-5-hydroxy-L-pipecolic acid from Morus alba and Lathyrus japonicus

cis-5-Hydroxy-L-pipecolic acid was isolated and characterized from the leaves of Morus alba and the seeds of Lathyrus japonicus. The trans-form was also obtained from the former.     

Photosynthetic activities of a thermophilic blue-green alga

Photosynthetic activities of a thermophilic blue-green alga,a species of Synechococcus, were studied with special referenceto its growth at high temperatures. A rapid algal growth occurredin the temperature range between 50 and 60?C, showing the maximumrate, six doublings per day, at about 57?C. Photosynthetic oxygenevolution and methyl viologen photoreduction in the cells werealso active at high temperatures and the optimum temperaturesfor these activities agreed with that of the algal growth. Thegrowth and photosynthetic activities were very low at room temperatureand irreversibly inactivated at temperatures above 60?C. The thylakoid membranes isolated from the alga were also photochemicallyactive at high temperatures. The membranes mediated ferricyanidephotoreduction coupled with a stoichiometric oxygen evolutionat a rate comparable to that of photosynthetic oxygen evolutionin the cells. The optimum temperature for the reaction was ashigh as 50?C. The membranes also showed a photosystem I-mediatedreaction at high temperatures. These observations indicate thatthe thylakoid membranes are intrinsically thermophilic in thisorganism. Thus the growth of the alga at high temperatures canbe well correlated to thermophilic properties of the photosyntheticapparatus. (Received February 20, 1978; )     

Effects of dibromothymoquinone and bathophenanthroline on flash-induced cytochrome f oxidation in spinach chloroplasts

The effects of several electron transport inhibitors on themagnitude and kinetics of cytochrome f oxidation induced byflash illumination were studied in the - and -band regions.On the flash excitation only a fraction of cytochrome f presentin the chloroplasts was oxidized with a half time of 0.1 to0.3 msec and then reduced with a half time of 10 to 25 msec. Dibromothymoquinone (DBMIB) at concentrations which severelysuppressed the reduction of cytochrome f approximately doubledthe magnitude of cytochrome f oxidation caused by a flash, mainlyby inducing an additional slow oxidation of cytochrome f witha half time longer than 1 msec. Enhancement of the cytochromef oxidation was also observed in the presence of bathophenanthroline.Such enhanced oxidation in duced by the two inhibitors was largelydiminished with the addition of reduced 2,6-dichlorophenolindophenolwhich accelerated cytochrome f reduction. In contrast, the inhibitionof cytochrome f reduction by 3-(3,4-dichlorophenyl)-1,1-dimethylurea(DCMU) was not associated with an increase in the magnitudeof cytochrome f oxidation. However, addition of DBMIB to theDCMU-poisoned chloroplasts enhanced cytochrome f oxidation,suggesting that this is related to a block of the electron transportbetween plastoquinone and cytochrome f. The results are explainedby assuming the occurrence of an electron carrier between plastoquinoneand cytochrome f. (Received May 10, 1978; )     

Oxidation and reduction of plastoquinone by photosynthetic and respiratory electron transport in a cyanobacterium Synechococcus sp.

The I-D dip, an early transient of the fluorescence induction, was examined as a means to monitor redox changes of plastoquinone in cells of a cyanobacterium, Synechococcus sp. That the occurrence of the dip depends upon the reduced state of the plastoquinone pool was indicated by observations that 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone and 3-(3,4-dichlorophenyl)-1,1-dimethylurea did not affect the initial rise to I but abolished the subsequent decline from I to D and that illumination of the cells with light 1, prior to fluorescence measurements, eliminated the transient. The I-D dip was prominent in freshly harvested cells containing abundant endogenous substrates, disappeared slowly as the cells were starved by aeration but reappeared on addition of fructose to the starved cells in the dark. The dip that had been induced by a brief illumination of the starved cells with light 2 was rapidly diminished in the dark and KCN inhibited the dark decay of the transient. The results indicate that plastoquinone is reduced with endogenous as well as exogenous substrates and oxidized by a KCN-sensitive oxidase in the dark, thus providing strong support for the view that plastoquinone of photosynthetic electron transport also functions in respiration. In addition, the occurrence of a cyclic pathway of electrons from Photosystem I to plastoquinone, possibly via ferredoxin or NADP, was suggested. Several lines of evidence indicate that, under a strong light 2, Photosystem I-dependent oxidation of plastoquinone predominates over Photosystem II-dependent reduction of the quinone in the cyanobacterium which contains Photosystem I more abundantly than Photosystem II.     

Purification and characterisation of β-N-acetylhexosaminidase from the butter clam, saxidomus purpuratus

A β-N-acetylhexosaminidase [EC 3.2.1.30] has been purified ～98-fold from an extract of the digestive organs of Saxidomus purpuratus by using ammonium sulfate fractionation, and chromatography on Toyopearl HW-50, CM-cellulose, and Sepharose 4B. The purified enzyme, the molecular weight of which was estimated to be ～66,000 by gel filtration, was composed of two sub-units of molecular weight 30,000 as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The purified enzyme had a pH optimum of 3.8 and an optimum temperature of 55°, and its activity was enhanced ～2-fold in the presence of 0.1m sodium chloride. The Michaelis constants toward p-nitrophenyl 2-acetamido-2-deoxy-β-d-glucoside and -galactoside were 1.2 × 10^?4 and 1.3 × 10^?4m, respectively.