Procedures for the production and separation of H and M antigens in histoplasmin: Chemical and serological properties of the isolated products

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.     

An examination of the developing cotton fiber: Wall and plasmalemma

Summary The ultrastructure of developing cotton fibers has been examined using novel modifications of the techniques of surface replication, freeze-etching and thin-sectioning. The fiber surface was found to be coated with a lamellar cuticle, which is stretched and thinned as the fiber elongates. It is marked by bars which run parallel with the fiber long axis. Beneath the cuticle, the outermost microfibrils of the primary wall lie parallel with the fiber axis, while those adjacent to the plasma membrane are transverse. Primary wall microfibrils are present in bundles, disposed in left-handed and right-handed helices, which correspond with the fibrils observed optically. Microfibrils within bundles form in-phase waves, with wavelengths and amplitudes in the ranges 0.3–7 m and 0.01–0.1 m in primary and secondary walls respectively. As elongation proceeds bundles become displaced towards the cell axis. Microfibrils of the secondary wall, disposed around the cell as fast helices, are similarly bundled and wavy (though with a reduced amplitude). In surface-replicas, large (20–30 nm) granules are present on the cytoplasmic face of the wall which probably correspond with 20–40 nm low prominences visible on freeze-etch EF plasma membrane fracture faces. It is proposed that these may be microfibril-synthesizing centers. Plasma membranes fracture such that the membrane-associated-particles segregate 6040 between P and E fracture moieties, but the prominence and total number of these particles is reduced at the stage of secondary wall formation as compared with primary wall formation. Beneath the plasmalemma the axes of microtubules parallel secondary wall microfibril orientation. Cross-bridges, which stain heavily after glutaraldehyde/tannic acid fixation, link microtubules to plasma membrane. The use of butyl benzene to cement fragments of cotton fibers, employed in this work, may prove useful in other freeze-etch studies of long fibers which are readily ruptured during preparation.     

STUDIES OF HAWAIIAN FRESHWATER AND SOIL ALGAE II. ALGAL COLONIZATION AND SUCCESSION ON A DATED VOLCANIC SUBSTRATE1,2

Spatial studies of colonization and succession of soil algae and chemical analyses of the various soils on the cinde cone of Kilauea Iki in Hawaii Volcanoes National Park, Hawaii are outlined. There is a positive correlation between the diversity and quantity of soil algae with nutrient levels and organic matter accumulation in each locale. Three distinct edaphic-biotic zones existing in this area are differentially revealed by the soil chemical composition, quantity and diversity of soil algae, and as evident variations in higher plant growth and colonization. Varying colonization and successional phases of higher plant growth around standing and fallen tree snags killed by volcanic activity also reflect variations in the soil algal flora. These variations appear largely as a function of differential water interception, absorption, and retention as well as differential accumulation of organic matter, and the initiation of various biogeochemical cycles.     

24-methylenepollinastanol and 24-dehydropollinastanol—two sterols of pollen

The esterified and unesterified sterol fractions of bee-gathered mixed pollens were examined, and total sterol composition was determined. Two new sterols of pollens, 14α-methyl-9β,19-cyclo-5α-cholest-24-en-3β-ol (24-dehydropollinastanol) and 14α-methyl-5α-ergost-24(28)-en-3β-ol (24-methylenepollinastanol) were isolated and identified. Both sterols were found primarily in the esterified sterol fraction, and 24-methylenepollinastanol accounted for 43% of the sterols of this fraction. 24-Dehydropollinastanol and four other sterols which also contain a 9β,19-cyclopropane ring were found only in the esterified sterol fraction. 24-Methylenecholesterol was the major sterol of the unesterified sterol fraction.     

A 13C NMR study of the biosynthesis of the anthraquinone dothistromin by Dothistroma pini

A ¹³C-NMR study of the biosynthesis of dothistromin by Dothistroma pini was undertaken. The biosynthetic labelling pattern in this bistetrahydr     

The biology of a giant dung-beetle (Heliocopris dilloni) (Coleoptera: Scarabaeidae)

Heliocopris dilloni is the largest dung-beetle found in the Tsavo National Park, Kenya, which during the biannual rainy seasons comprises the most important agency of elephant dung removal. The species is shown to exhibit considerable morphological variation. The mode of construction of the brood chamber is described together with details of development from egg to pupa. It is suggested that the depth to which these beetles burrow is related to avoiding the extreme climate near the surface and to predator avoidance.     

The effect of vitamin E analogues and long hydrocarbon chain compounds on calcium-induced muscle damage. A novel role for α-tocopherol?

Previous studies have demonstrated that supplemental α-tocopherol inhibited calcium-induced cytosolic enzyme efflux from normal rat skeletal muscles incubated in vitro and suggested that the protective action was mediated by the phytyl chain of α-tocopherol [1]. In order to investigate this further a number of hydrocarbon chain analogues of tocopherol (7.8-dimethyl tocol, 5,7-dimethyl tocol, tocol, α-tocotrienol, α-tocopherol [10], vitamin K1, vitamin K1 [10], vitamin K1 diacetate, vitamin K2 [20], phytyl ubiquinone and retinol) were tested for any ability to inhibit calcium ionophore, A23187, induced creatine kinase (CK) enzyme efflux. Some compounds were found to be very effective inhibitors and comparison of their structures and ability and to inhibit TBARS production in muscle homogenates revealed that the effects did not appear related to antioxidant capacity or chromanol methyl groups, but rather the length and structure of the hydrocarbon chain was the important mediator of the effects seen.     

Fecundity,reproductive effort,and pupal size in the profundal midgeChironomus cuccini (Diptera: Chironomidae)

Fecundity ofChironomus cucini increased linearly across a three-fold range of female pupal biomass. Females from a lake producing small pupae (Crystal Lake) had an average of 303 primary follicles, while larger pupae from Trout Lake had an average fecundity of 582. Pupae produced in Crystal Lake from larvae that received experimental food supplements were intermediate in size and fecundity. Pupal biomass explained 76% of the variation in fecundity. No difference in egg size was detected between pupae from the two lakes, and an average value of 2.1 g egg^–1 was used to calculate the total biomass allocated to eggs in each of 79 females dissected. This measure of reproductive effort scaled isometrically with pupal mass. On average, females allocated 48% of their biomass to eggs and 52% to somatic tissues. A comparison of average male biomass to female somatic biomass across 12 populations indicated that the biomass difference between the sexes is a biased predictor of fecundity.