Immunohistochemical localization of proteoglycans in interstitial elements of human pancreas and biliary system

Summary The immunohistochemical localization of large proteoglycan and small proteoglycan was observed, using antibodies 2B1 and 6B6 (Sobueet al., 1988, 1989a), in fetal and adult pancreas and biliary system as well as in tumour tissues, obtained from 11 autopsies and 74 biopsies. The distribution of chondroitin 4- and 6-sulphate side chains, type I and IV collagen and elastin were also studied. In adult pancreas and all the biliary tracts examined, periductal fibrous tissues consisted mainly of dermatan sulphate small proteoglycan with networks of fibrous elements, which were composed of large proteoglycan, elastin, type I collagen and type IV collagen. In the interstitial components of cystadenoma of pancreas and biliary duct carcinoma, similar small proteoglycan-rich components were relatively abundant, although large proteoglycan was present in much larger amounts than that in non-neoplastic adult tissues. In some cholangiomas, the extra-and intracellular hyaline globules formed by the carcinoma cells were found to contain chondroitin sulphate large proteoglycan, laminin and fibronectin.The distribution of proteoglycans was observed to be different in the arterial walls of the interlobular tissues of the adult and the fetal pancreas. The biological significance of large and small proteoglycans in the interstitial connective tissues was discussed.     

Alterations of human erythrocyte membrane fluidity by oxygen-derived free radicals and calcium

Two possible reasons for the structural alterations of cell membranes caused by free radicals are lipid peroxidation and an increase in the intracellular calcium ion concentration. To characterize the alterations in membrane molecular dynamics caused by oxygen-derived free radicals and calcium, human erythrocytes were spin-labeled with 5-doxyl stearic acid, and alterations in membrane fluidity were quantified by electron spin resonance oxidase (0.07 U/mL) decreased membrane fluidity, and the addition of superoxide dismutase and catalase inhibited the effect on membrane fluidity of the hypoxanthine-xanthine oxidase system. Hydrogen peroxide (0.1 and 1 nM) also decreased membrane fluidity and caused alterations to erythrocyte morphology. In addition, a decrease in membrane fluidity was observed in erythrocytes incubated with 2.8 mM CaCl₂. On the other hand, incubation of erythrocytes with calcium-free solution decreased the changes in membrane fluidity caused by hydrogen peroxide.

These results suggest that changes in membrane fluidity are directly due to lipid peroxidation and are indirectly the result of increased intracellular calcium concentration. We support the hypothesis that alterations of the biophysical properties of membranes caused by free radicals play an important role in cell injury, and that the accumulation of calcium amplifies the damge to membranes weakened by free radicals.     

Specific arrangements of cortical microtubules are correlated with the architecture ofmeristems in shoot apices of angiosperms and gymnosperms

Arrangements of corticalmicrotubules (MTs) as seen in median longitudinal cryosections of shoot apices of several angiosperms and gymnosperms were studied by indirect immunofluorescence microscopy.Bryophyllum, Clethra, Helianthus, Houttuynia, Vinca (angiosperms), andPinus, Cedrus, Cedrus andGinkgo (gymnosperms) were examined. In all angiosperm apices collected during the growing season, MTs were mainly arranged anticlinally in the tunica, randomly in the corpus, and transversely in the rib meristem. This pattern of arrangements of MTs was further confirmed by electron microscopy inBryophyllum apices. In the apices of winter shoots MTs in the rib meristem were arranged randomly, indicating a seasonal change with respect to their arrangment. In all examined gymnosperm apices, populations of superficial cells showed both random and anticlinal arrangements of MTs, in contrast to those of angiosperm apices that consistently show anticlinally arranged MTs. In the shoot apices of both angiosperms and gymnosperms, cortical MTs were arranged perpendicularly to the directions of cell expansion. The significance of MTs in the maintrnance of the different architectures of shoot apices in angiosperms and gymnosperms is discussed.     

Asymmetric transport of D-glucose anomers across the human erythrocyte membrane

The anomeric preference in the influx and efflux of D-glucose across the human erythrocyte membrane was studied. beta-D-Glucose was transported 1.5 times faster than alpha-D-glucose into the cells, when washed cells were incubated at 20 degrees C in medium containing either alpha- or beta-D-glucose (100 mM). On the other hand, no difference between half-times of efflux of the two anomers was distinguishable. The result demonstrates the presence of influx-efflux asymmetry in anomeric preference in D-glucose transport across the human erythrocyte membrane, and is consistent with the view (Barnett et al., Biochem. J. 145, 417-429, 1975) that the C-1 hydroxyl group of D-glucose interacts with the D-glucose transport protein only in the influx, but not in the efflux.     

Uptake of Gibberellin Methyl Esters by Spores and Induction of Dark Germination in Lygodium japonicum

In the fern Lygodium japonicum, the effect of the exogenousapplication of two gibberellin methyl esters, gibberellin A₄methyl ester (GA₄Me) and gibberellin A₂₀ methyl ester (GA₂₀Me)on spore germination in the dark and uptake of GA₄Me and GA₂₀Meby spores was investigated. Tritiated GA₄Me and GA₂₀Me wereprepared and used as radioactive tracers. The activity of GA₄Mewas more than 100-fold that of GA₂₀Me for the induction of sporegermination. When treated for 24 h, the activity for inducingspore germination remained after removal of the gibberellinmethyl esters from the medium. The amount of GA₄Me taken upby spores was more than three times that of GA₂₀Me throughoutthe 24 h time course of treatment. The uptake of both gibberellinmethyl esters was proportional to the external concentrationfor the range of concentrations between 10^–9 M and 10^–6M. When treated with the tritiated gibberellin methyl estersat 10^–6 M and 10^–7 M for 24 h, most of the gibberellinmethyl esters taken up by the spores were not metabolized. Althoughthe uptake of the two gibberellin methyl esters differed by3- to 5- fold, their abilities to induce spore germination differedby more than 100-fold. Therefore, the difference in the activityof the two gibberellin methyl esters regarding the inductionof spore germination could not be explained solely by the differencein their uptake. (Received January 11, 1988; Accepted May 26, 1988)     

Adherence of streptococci to surface-modified glass

Four types of surface-modified glass were prepared. Aminopropyl glass was prepared by alkylsilylation of glass slides with gamma-aminopropyltriethoxysilane. This glass carries primary amino groups which may be protonated at pH 7.2. Owing to the presence of both positively charged ions and hydrophobic ethoxyl groups, the glass is considered to be amphipathic. Three other types of surface-modified glass slides were prepared from aminopropyl glass by forming Schiff's bases with three aldehydes: glucose, glyoxylic acid and hexanal. The aldehyde-treated slides were subsequently reduced using sodium borohydride. Thus, the surface of the glass was rendered hydrophilic, ampholytic or hydrophobic, respectively. The adherence of two Streptococcus sanguis strains and two Streptococcus mutans strains to the surface-modified glass slides was studied. Different strains showed differences in adherence to these slides depending on their physico-chemical surface properties. For S. sanguis ATCC 10556, hydrophobic bonds seemed to be most important, while in S. mutans OMZ 176, ionic interactions made the highest contribution to adhesion. Hydrogen bonds seemed to contribute least to adherence.     

In vitro propagation of Glehnia littoralis from shoot-tips

Shoot cultures of Glehnia littoralis F. Schmidt ex Miq. (Umbelliferae) were established by placing shoot tip explants on Linsmaier and Skoog medium with 1 M NAA and 10 M BAP. Shoots were multiplied on the basal medium supplemented with 0.3 M NAA and 3 M BAP and rooted on medium containing either 1 M IBA or 3–10 M IAA. Plantlets survived in pots without any covering. This unique characteristic of the plantlets was ascribed partly to a well-developed cuticle on the surface of the leaf and the small ratio of surface area to fresh weight of a leaf blade in comparison with those of other species whose plantlets needed coverings after potting. The regenerated plantlets were finally transferred to soil.Abbreviations IAA potassium indole-3-acetate - IBA indole-3-butyric acid - IPA indole-3-propionic acid - NAA potassium 1-naphthaleneacetate - 2,4-D sodium 2,4-dichlorophenoxyacetate - BAP 6-benzylaminopurine - 2-iP N⁶-(2-isopentenyl)adenine     

Development of shoot inHydrangea macrophylla I. Terminal and axillary buds

The structure of shoots, in particular of winter buds, ofHydrangea macrophylla was examined. The non-flower-bearing shoot is usually composed of a lower and an upper part, between which a boundary is discernible by means of a distinctly short internode. This internode is the lowermost of the upper part, and it is usually shorter than the internodes immediately above and below, although the internodes tend to shorten successively from the proximal to the distal part of the shoot. Variations exist in the following characters among the terminal bud, the axillary bud on the lower part of the shoot and the axillary bud on the upper part: (1) length of bud; (2) character of the outermost pair of leaf primordia; (3) degree of development of secondary buds in the winter bud; and (4) the number of leaf primordia. Usually, the terminal bud contains several pairs of foliage leaf primordia with a primordial inflorescence at the terminal of the bud, but the axiallary bud contains only the primordia of foliage leaves in addition to a pair of bud scales.     

In vitro penetration of zona pellucida of salt-stored bovine oocytes before and after maturation by frozen-thawed spermatozoa

Bovine oocytes, before and after maturation in culture, were stored in PBS with 2 M-(NH(4))(2)SO(4) + 0.1% dextran or 2 M-(NH(4))(2)SO(4) + 40 mM-Hepes + 0.5% dextran and were inseminated with frozen-thawed spermatozoa in BO medium with caffeine (5 mM) and heparin (10 mug/ml). The penetration rates of mature oocytes were very low (19 to 24%) and not significantly different between the two salt solutions in which the oocytes were stored for 2 to 89 days. Significantly lower (P < 0.01) penetration rates were observed in immature (7 to 8%) than in mature (20 to 21%) oocytes stored in the two solutions. The synergistic effect of caffeine and heparin was observed in the penetration rate of fresh mature oocytes but not in the stored oocytes, indicating the difficulty of assessing sperm capacitation and/or acrosome reaction of salt-stored mature bovine oocytes under the present condition. Using 0.1% protease the solubility of the zonae decreased in salt-stored but not in fresh oocytes, but there was no significant difference between the immature and mature oocytes regardless of storage in the salt solutions. It appears from these results that some alteration was induced in the nature of zona glycoprotein by ammonium sulfate solution.