REINVESTIGATION OF THE FINE STRUCTURE OF REINKE''S CRYSTAL IN THE HUMAN TESTICULAR INTERSTITIAL CELL

Testicular biopsy materials of men were examined with the electron microscope equipped with a tilling stage. An optical transformation method was applied for the electron microscope images. An attempt was made to clarify relationships between the contour and the internal pattern of Reinke's crystal in the interstitial cell. The shape of this crystal is a hexagonal prism. Three types of internal patterns are observed in relation to the main planes of the crystal. The crystal consists of 50-A-thick filaments. It is trigonal, a = 300 A, c = 450 A, being similar to catalase crystals studied by X-ray diffraction and electron microscopy (20), but the dimensions are different. Dislocations of Reinke's crystal are also analyzed. In some interstitial cells without Reinke's crystal, specially arranged 50-A-thick filaments are observed. They are similar in arrangement to the pattern within Reinke's crystal, but not so closely compacted. Morphological similarities and dissimilarities between this crystal and other crystal and crystalloid structures are discussed.     

Analysis of contagiousness in the action of mortality factors on the western tent caterpillar population by using the\mathop m\limits^* - m relationshiprelationship

The contagiousness in the operation of mortality processes on the colonies of the western tent caterpillar, Malacosoma californicum pluviale, was analyzed from two different aspects: successive changes in the frequency distribution of the number of surviving individuals per colony in the course of development, and the distribution pattern of the individuals killed by some biotic mortality factors. Also, for a tachinid parasite, Tachinomyia similis, the analysis was made on the egg-laying pattern on colonies as well as on individual larvae. The methods of these analyses were all based on the relation of mean crowding (m) on mean . A braconid parasite, Rogas sp., tended to kill few individuals together once it attacked a colony, but its effect on host colonies was rather equivalent to the random removal of individuals from all the colonies. Diseases in the late-stage larvae before cocooning was contagious in their action. Nuclear polyhedrosis virus seemed to have no basic contagiousness in its action, but it caused highly contagious distribution of deaths among the colonies when its average incidence was high. A spore-forming Bacillus had a tendency to kill several individuals once it appeared in a colony, but the distribution of its incidence (no. of times it appeared per colony) was considered to be nearly at random. The female of Tachinomyia tended to lay more than one egg successively on the same colony. It also attacked individual larvae with a definite tendency for aggregation, which seemed to be resulted from the parasite's preference to large hosts. When the number of eggs laid on prefered hosts exceeded a certain threshold, however, the fly seemed to change its attention to less attractive, smaller individuals.     

Variation in Natural Abundance of 15N among Plant Parts and in 15N/14N Fractionation during N2 Fixation in the Legume-Rhizobia Symbiotic System

Sixteen legumes were grown in N-free media so that N was suppliedentirely by symbiotic N₂ fixation. The plant tissues were analyzedfor natural ¹⁵N abundance (expressed as ¹⁵N per mil relativeto air N₂) with a ratio mass spectrometer. The nodules of desmodium,centro, siratro, soybean and winged bean showed high enrichmentin ¹⁵N (+9), while red clover showed slight enrichment (+2).The nodules of 9 other forage legumes (Townsville stylo, whiteclover, alsike clover, common vetch, Chinese milk vetch, senna,alfalfa, ladino clover, and hairy vetch) showed little enrichmentin ¹⁵N. In all the legumes investigated, particularly in the ureide-transportingplants such as desmodium, centro, siratro, soybean, winged beanand field bean, the ¹⁵N value of the shoots was negative (–3.2).The ¹⁵N value of the shoots in winged bean and field bean variedby about 1 depending on the Rhizobium strains used. The isotopicmass balance of 13 legumes indicated that isotopic fractionationoccurs during N₂ fixation by the legume-rhizobia symbiosis witha preference for ¹⁴N over ¹⁵N, resulting in a ¹⁵N value of –0.2to –2 in the whole plant. The results indicate that ¹⁵N/¹⁴N isotopic discrimination witha preference for the lighter atom may occur in both N₂ fixationand export of fixed N from nodules. ¹Present address: Department of Soils and Fertilizers, NationalAgriculture Research Center, Kannondai, Tsukuba, Ibaraki 305,Japan. (Received October 8, 1985; Accepted April 7, 1986)     

Extraction and purification of a new compound containing selenium and mercury accumulated in dolphin liver

Dolphins sometimes accumulate Hg and Se as high as 100 μg/g or more in their livers. In the present study, a compound containing Hg and Se in a dolphin liver was extracted and purified by cation exchange, gel filtration, and paper, anion exchange, and chelate chromatographies. The Hg and Se contents in every fraction were determined by atomic absorption spectrometry using the palladium addition method. In all chromatographic fractions Hg and Se appeared in the 1∶1 molar ratio. The purified compound is water-soluble, with a molecular weight of less than 1000, and contains amino-groups, as well as Hg and Se at a 1∶1 molar ratio. Mercury in the compound is not removed by the chelate resin, indicating that the metal is not ionic and is tightly bound.     

Microbial mutagenicity of 3- and 4-ring polycyclic aromatic sulfur heterocycles

The stable isomers of 3- and 4-ring polycyclic aromatic sulfur heterocycles were tested for mutagenicity in the Ames standard plate incorporation test and a liquid pre-incubation modification of the Ames test. Of the 4 three-ring compounds tested, only naphtho[1,2-b]thiophene was mutagenic. Of the four-ring compounds, 7 of 13 were mutagenic in the standard Ames or pre-incubation Ames test. The highest activity for the 4-ring compounds was observed for phenanthrol[3,4-b]thiophene, a compound of approximately the same mutagenic potency in the Ames test as benzo[a]pyrene. The other active 4-ring compounds were of considerable less mutagenic potency than phenanthrol[3,4-b]thiophene. Mutagenicity for two of the 4-ring aromatic thiophenes could only be detected in the liquid pre-incubation Ames test. Salmonella typhimurium TA100 was the most sensitive strain to mutagenesis by these compounds, followed by TA98. All mutagenesis was indirect, requiring metabolic activation.     

Structural and regulatory studies on the ribulose bisphosphate carboxylase-oxygenase of Anabaena cylindrica

Ribulose 1,5-bisphosphate (RuBP) carboxylase-oxygenase fromthe cyanobacterium Anabaena cylindrica has been purified tohomogeneity by the criterion of polyacrylamide gel electrophoresisand shown to consist of two types of subunits of molecular weights51K (large) and 12K (small). The enzyme is of the higher planttype and probably consists of 8 large plus small subunits. Isoelectricfocusing of the S-carboxymethylated protein in 8 M urea revealeda profile of consisting of 3 major polypeptides plus 1 minorpolypeptide. Some characteristics of the carboxylase and oxygenasereactions were studied using simultaneous measurements of bothactivities. Pyridoxal 5'-phosphate inhibited both activitiesequally. Neither the carboxylase nor oxygenase reaction wasaffected by glutamate (5 mM), although 6-phosphogluconate andfructose 1,6-bisphosphate inhibited both reactions. RuBP oxygenasewas more sensitive to 6-phosphogluconate (0.5 and 1.0 mM) thanRuBP carboxylase. Marked changes in the oxygenase to carboxylaseactivity ratio of the purified enzyme were effected by homologousantiserum (which preferentially inhibited carboxylation). ¹Present address: Institute of Applied Microbiology, Universityof Tokyo, Bunkyo-ku, Tokyo 113, Japan. (Received May 22, 1980; )     

Measurement of rate constants for quenching singlet oxygen with a Cypridina luciferin analog (2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin-3-one) and sodium azide

The rate constants for [¹O₂] [MCLA] and [¹O₂][NaN₃] were measured by quenching the near-infrared emission (¹Δ_g→³∑_g) in steady state with MCLA and NaN₃, respectively. ¹O₂ was constantly generated by energy transfer to O₂ from Ar laser-excited Rose Bengal. The Stern—Volmer plots yielded the second-order rate constants of 2.94 × 10⁹ M^?1 S^?1 and 3.83 × 10⁸ M^?1 S^?1 for quenching ¹O₂ with MCLA and NaN₃ in water at pH 5.4, respectively. The ¹O₂ + MCLA reaction emitted light with maximum at 465 nm at pD 4.5 identical to the O₂^? + MCLA reaction.     

The role of sialic acid in the nerve terminal for the release of transmitter

The role of sialic acid in the frequency of miniature endplate potentials (MEPPs) was examined using neuraminidase and gangliosides in the mouse diaphragm. Neuraminidase increased and decreased MEPP frequency in normal K⁺ and high K⁺ solution, respectively. The effects were dependent on the presence of Ca²⁺ in extracellular medium. Neuraminidase liberated sialic acid from and lowered Ca²⁺- binding capacity of synaptosomal membrane. Gangliosides treatment of the tissue partially restored the effects of neuraminidase on the frequency of MEPP and Ca²⁺-binding capacity. It is possible that sialic acid in the nerve endings provides a functional storage site which supply intracellular Ca²⁺ to cause a transmitter release.