20-羟基蜕皮酮对蓖麻蚕蛹体液免疫的调节作用(英)

本研究指出20—羟基蜕皮酮(20-OHE)参加蓖麻蚕蛹对大肠杆菌的体液免疫反应。20-OHE的作用方式是多方面的,包括提高血淋巴蛋白质含量,产生抗菌蛋白,增加溶菌酶活性,和激活原酚氧化酶系统。这表明多个免疫控制系统参与蓖麻蚕蛹体液免疫反应的可能性。     

COMPARATIVE ULTRASTRUCTURAL STUDIES OF SPERMATOGENESIS IN THE METZGERIALES (HEPATICAE). I. THE BLEPHAROPLAST OF PALLAVICINIA LYELLII

The blepharoplast in the young spermatid of Pallavicinia is similar to that of other hepatics in that it comprises a four-layered multilayered structure (MLS) and two staggered, dimorphic basal bodies. The spline, approximately 40 μm in length and extending through nearly two full gyres, comprises 20 parallel microtubules at its anterior end and narrows to 17 at the posterior limit of the subjacent lamellar strip (LS). Behind this, the spline shank, approximately 32 μm in length, is reduced to six tubules. The LS curves around the spermatid, following the anterior one-third of the first gyre of the spine, and is approximately 7.5 μm in length, the longest yet recorded for the bryophytes. It is spatulate in outline, equaling the width of the spline anteriorly but tapering steeply from the right-hand side behind the anterior basal body (ABB). It then extends posteriorly as a narrow strip beneath the left-hand margin of the spline. The basal bodies of the greatly staggered flagella are nonoverlapping and separated by a distance of about 4.4 μm. The subapical ABB and PBB measure (including the ventral triplet extensions and transition zones) 1.2 μm and 2.4 μm in length, respectively. A short, narrow aperture equaling one tubule-diameter in width is located in the spline directly beneath the ABB. The anterior mitochondrion is about 7 μm long and follows the outline of the overlying LS, while a cupshaped posterior mitochondrion is appressed to the plastid. Comparisons with other taxa indicate that major distinguishing features of metzgerialian blepharoplasts are highly staggered, nonoverlapping basal bodies, greatly elongate anterior mitochondria, and six-tubule shanks. Great differences between the spermatids suggest wide phylogenetic discontinuities between the genera of the Metzgeriales.     

EVALUATION OF THE SPECIFICITY OF A LYMPHOID CHALONE

An extract from calf spleens, injected into mice, was found to inhibit their lymphocyte proliferative response to PHA-M and PWM in vitro. Despite the ability of the spleen extract to inhibit the response of lymphocytes to stimuli in vitro, no effect was observed on the repopulation of lymphocytes in the peripheral blood of sublethally irradiated mice. The data suggest that the spleen extract acts as a specific inhibitor of the immune competent cells since neither the precursors of lymphocytes nor other haematopoietic cells were affected.     

THE UPTAKE OF BIOGENIC MONOAMINES BY THE ISOLATED AURICLE OF THE SNAIL (HELIX POMATIA)

—The uptake of [³H]5HT, [³H]dopamine, [³H]noradrenaline and [³H]octopamine into the auricle of Helix pomatia was studied. When tissues were incubated at 25°C in media containing radioactive amines, tissue:medium ratios of about 49:1, 14:1 and 5:1 for 5-HT, dopamine, noradrenaline, and octopamine respectively were obtained after a 20–30 min incubation time. Tissues incubated at 25°C in media containing radioactive amines for 20–30 mins showed that almost all (96%) the radioactivity was present as unchanged [³H]5-HT, [³H]dopamine, [³H]octopamine or [³H]noradrenaline. The high tissue:medium ratios for 5-HT and dopamine, but not for noradrenaline and octopamine, showed saturation kinetics which were dependent upon temperature and sodium ions. From the Lineweaver–Burk plots, two uptake mechanisms for 5-HT at 25°C were resolved; the high affinity uptake process having a K_m1 value of 6.0 ± 10^?8m and a V_m1 value of 0.115 nmol/g/min while the lower affinity process had a K_m2 value of 1.04 ± 10^?6m and a V_m2 value of 0.66nmol/g/min. At 0°C a single uptake mechanism for 5-HT occurred which gave a K_m value of 5.02 ± 10^?8m and a V_m value of 0.0165 nmol/g/min. In the case of dopamine, the Lineweaver–Burk plot at 25°C showed a single uptake process with values for K_m and V_m of 1.55 ± 10^?7m and 0.086 nmol/g/min respectively. This process did not function at 0°C. The effect of various agents and ions upon the accumulation processes for all amines was also studied, and the data indicate that the same neurons probably accumulate more than one amine type. It is concluded that 5-HT and dopamine uptake in the auricle is a mechanism for inactivating these substances at 25°C and that an uptake mechanism for 5-HT also functions at 0°C. The results are discussed from the point of view of 5-HT's being the cardioexcitatory substance in the snail heart.     

EFFECT OF PARASITIZATION BY THE PUPAL ENDOPARISITOID,PTEROMALUS PUPARUM (HYMENOPTERA: PTEROMALIDAE) ON HUMORAL IMMUNE REACTIONS OF PIERIS RAPAE (LEPIDOPETERA: PIERIDAE)*

Abstract Studies on the effect of parasitization by the endoparasitoid on host humoral immune reactions are carried out with the pupal endoparisitic wasp, Pteromalus puparum, and its host, Pieris rapae. Phenoloxidase (PO) activity of parasitized hosts hemolymph increased significantly at 12 h, day four and day five after parasitization. Hem‐agglutination activity of parasitized hosts hemolymph was always higher than that of wounded and unparasitized ones. Moreover, antibacterial activity of parasitized hosts hemolymph became more and more stronger, whilst wounded and unparasitized pupae only owned a weak antibacterial activity. It suggested that activities of humoral immune factors of Pieris rapae could be influenced to some degrees by P. puparum.     

THE QUANTITATIVE DETERMINATION OF THE INFECTIVITY OF AGROBACTERIUM TUMEFACIENS

A bioassay relating number of Agrobacterium tumefaciens cells in the inoculum quantitatively to the number of crown-gall tumors initiated on primary pinto bean leaves is described. Variability in estimation of infectious titers by this assay is similar to that observed in comparable plant virus assays, most determinations showing standard errors of 20% of the mean tumor per leaf value. The assay has the advantages of speed and practicality. The efficiency of the system is low, typically requiring between 10⁵ and 10⁶ bacteria for each tumor initiated. Infectivity titers of 10³-10⁴, however, are readily obtained from stationary phase cultures. Statistical analysis of the infectivity titration curve indicates that a single bacterium is the usual infectious unit. The assay is specific within the family Rhizobiaceae to the species Agrobacterium tumefaciens and Agrobacterium rubi. A. tumefaciens strains IIBNV6 and ATCC # 11095 were non-infectious, while strain B6 was the most infectious of the strains tested. The infectivity of the latter strain is shown to decrease about 4-fold between early log and stationary phases of growth. Changes in the growth medium or in the dilution-inoculation medium failed to alter the infectivity of the bacterium.     

CYTOTAXONOMY OF THE ELEOCHARIS TENUIS COMPLEX

Chromosome numbers of 2n = 20, 24, 36, and 38 were found in the various taxa comprising the Eleocharis tenuis complex in the United States. Eleocharis tenuis var. verrucosa, the only taxon in the complex with 2n = 20 is given the new status of a full species [E. verrucosa (Svens.) Harms] and seems most closely allied to two southern members of the subseries Truncatae which are not members of the tenuis complex s. s. Karyotypes and meiotic pairing in artificial hybrids indicate that the remainder of the taxa are derivatives of X = 6 with E. tenuis and one of two cytotypes of E. compressa with the lowest numbers of 2n = 24, although evidence is presented to indicate that they are of amphidiploid origin. A second cytotype of E. compressa with 2n = 36 is a segmental autoallohexaploid, whereas E. elliptica and E. elliptica var. pseudoptera (Svens.) Harms, comb. nov. with 2n = 38 are hyperploid derivatives of 2n = 36.     

IRRADIANCE DEPENDENCY OF UV-A INDUCED PHASE SHIFTS IN THE LOCOMOTOR ACTIVITY RHYTHM OF THE FIELD MOUSE MUS BOODUGA

In the nocturnal field mouse Mus booduga, the responsiveness of the circadian system to UV-A light of 2.5 W/m² and 30 minutes duration is known to be phase dependent. The results of our experiments indicate that the phase shifts evoked by UV-A at the two phases, CT14 (circadian time 14) and CT20 increases nonlinearly with irradiance. (Chronobiology International, 17(6), 777–782, 2000)     

THE WOOL-LIKE COVERING OF THE ROOTS OF LANNEA ALATA I. THE ORIGIN AND MORPHOLOGY OF THE WOOLY COAT

Lannea alata (Engl.) Engl., Anacardiaceae, a tree or shrub of East Africa, has roots covered with dense wool-like hair. Cork cambium of the root produces a closely appressed cork from which the hairs (modified cork cells) arise. Cork cells and wooly hair are rich in sterol and carotin-oid-like compounds and have thick walls. It is suggested that the root wool plays a role in the soil-air, soil-water relations of Lannea alata and other plants.     

CLONING AND SEQUENCING OF GENE ENCODING HYALURONIDASE FROM THE VENOM OF APIS CERANA CERANA*

Abstract The venomous hyaluronidase (Hya) gene of Chinese honey bee, Apis cerana cerana, was amplified by RT‐PCR from total RNA of venom glands of the worker bees. The full length of its nucleotide is 1164 bp encoding a 387 amino acid polypeptide with predicted molecular weight of 42.6 kD. The alignment of AcHya amino acid sequence with other 6 Hyas shows that AcHya is most closely related to the Hya of European honey bee, A. mellifera, with 91% amino acid identity. It also shares homology with Hya of Dolichovespul amacidata, Polistes annularis, Vespula vulgaris, Lutzomia longipalpis and Homo sapiens (sperm), with 54%., 52%., 46%, 27% and 20% amino acid identity, respectively. A phylogenetic tree of those hyaluronidases was drawn by using GENETYX program, the conservation, the relationship between molecular structure and function of 7 hyaluronidases as above was compared and analysed.     

EFFECTS OF LOWERING TEMPERATURE DURING CULTURE ON THE PRODUCTION OF POLYUNSATURATED FATTY ACIDS IN THE MARINE DIATOM PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE)1

The composition of fatty acids and contents of eicosapentaenoic acid (EPA) and polyunsaturated fatty acids (PUFAs) of the economically important marine diatom, Phaeodactylum tricornutum (Bohlin), were investigated to see whether reducing the culture temperature enhances the production of EPA and PUFAs. The contents of EPA and PUFAs of P. tricornutum were found to be higher at lower temperature when cultured at 10, 15, 20, or 25°C. When the cells grown at 25°C were shifted to 20, 15, or 10°C, the contents per dry mass of PUFAs and EPA increased to the maximal values in 48, 24, and 12 h, respectively. The highest yields of PUFAs and EPA per unit dry mass (per unit volume of culture) were 4.9% and 2.6% (12.4 and 6.6 mg·L^?1), respectively, when temperature was shifted from 25 to 10°C for 12 h, both being raised by 120% compared with the control. The representative fatty acids in the total fatty acids, when temperature was lowered from 25 to 10°C, decreased proportionally by about 30% in C_16:0 and 20% in C_16:1(n?7) but increased about 85% in EPA. It was concluded that lowering culture temperature of P. tricornutum could significantly raise the yields of EPA and PUFAs.     

THE ROLES OF PLANT HORMONES IN THE GROWTH OF THE COROLLA OF GAILLARDIA GRANDIFLORA (ASTERACEAE) RAY FLOWERS

Corolla elongation and the roles of plant hormones in this process in Gaillardia grandiflora Van Houtte ray flowers were examined. The sterile ray flowers elongated during a 2-day period, and corolla growth was accompanied by fresh and dry weight increases and epidermal cell elongation (greatest near the base of the corolla) but not by cell division. Corollas excised from young ray flowers were measured during treatment in vitro with solutions of plant growth regulators. They elongated in response to gibberellins and fusicoccin but did not respond to auxins, cytokinins, abscisic acid, ethylene, or inhibitors of ethylene biosynthesis. Sequential and simultaneous hormone applications indicated no additive or synergistic effects between hormones, but auxin did reduce gibberellin-promoted growth. Analyses of endogenous auxins showed no significant variation, and ethylene production decreased prior to elongation, while a 20-fold increase in endogenous gibberellin activity was observed just prior to rapid corolla elongation. It appears that corolla growth in Gaillardia is accomplished by an increase in gibberellin activity alone, that multiple hormone interactions are not important in the control of corolla growth, and that part of the mode of action of gibberellin is acid-induced growth.     

STUDIES OF SPERMATOGENESIS IN THE HEPATICAE. IV. ON THE BLEPHAROPLAST OF BLASIA

Spermatogenesis in Blasia pusilla L. was reexamined with electron optics to help evaluate conflicting results of the two earlier light microscope studies of this species. The present micrographic resumé of spermatid transformation confirms Sharp's observation of centrosomes in very young spermatids and agrees with Woodburn's general account of spermatozoid maturation. Further, male gamete development in Blasia is shown to be closely comparable to that of Marchantia and Pellia. It is concluded that Sharp's report of blepharoplast development in Blasia by fragmentation and coalescence was based on anomalous plant material.     

ANALYSIS OF THE KINETICS OF GRANULOSA CELL POPULATIONS IN THE MOUSE OVARY

The kinetics of granulosa cell populations in two types of follicles in ovaries of 28-day-old Bagg mice are investigated. The analysis includes estimations of mean values and standard deviations of the transit times (T_G1, T_S, T_G2 and T_C), the doubling time T_D, and the proliferative fraction p. First the percentage of labelled mitosis curve (PLM-curve) and the continuous labelling curve (CL-curve) are estimated. Then a hypothesis concerning the cell kinetics of the granulosa cells in the two follicle types is set up. The normal distribution is chosen to simulate the probability density functions of the transit times. On the basis of the hypothesis mathematical expressions for the PLM- and CL-curves are worked out. By fitting the calculated PLM-curve to the experimental one it is possible to estimate mean values and standard deviations of T_G1, T_S>, and T_G2. As a test of the hypothesis the CL-curve is calculated by means of the estimated parameter values and compared to the experimental one. The calculated PLM- and CL-curves are found to be in good agreement with the experimental data as far as both follicle types are concerned. It is concluded that the method is a useful procedure. The choice of a normal distribution does not imply a significant limitation of the method in these investigations. Moreover it is concluded that the hypothesis is plausible. This means, e.g., that the proliferative fraction is unity in the two follicle types and that there is no cell loss from the cell systems.     

THE NUTRITION OF CERTAIN SPECIES OF THE GREEN ALGA OEDOGONIUM

Machlis , Leonard . (U. California, Berkeley.) The nutrition of certain species of the green alga Oedogonium. Amer. Jour. Bot. 49 (2) : 171–177. Illus. 1962.—Evidence is presented showing that O. cardiacum and O. geniculatum require vitamin B₁₂ and an unknown growth factor released from soil into water during autoclaving. The unknown growth factor is shown not to be a number of things, to be retained on anion exchange columns, and to be partially purified by fractionation on the polydextran, Sephadex 50. It appears to be an organic substance with acidic properties. Isolates of Oedogonium presently in unialgal and axenic culture are listed and the methods used to obtain the axenic cultures and to grow them for nutritional studies are described.     

THE DYNAMICS OF TWO HYBRID ZONES IN APPALACHIAN SALAMANDERS OF THE GENUS PLETHODON

Two zones of intergradation between populations of Plethodon have been studied for 18 and 20 years, respectively. The data consist of systematic scores of colors, made at least twice annually. Near Heintooga Overlook in the Balsam Mountains (Great Smoky Mountains National Park), the salamanders' cheeks are gray. Proceeding north toward the Smokies, there is increasing frequency and intensity of red color at two, four, and six miles. There has been no change in the scores at any location. The width of the zone and our failure to detect any change can be explained by assuming neutrality of the character and random diffusion during the probable time since contact between the two intergrading forms, which most likely took place after the Hypsithermal Interval, 8,000–5,000 BP. At Coweeta Hydrologic Laboratory in the Nantahala Mountains, Plethodon jordani and P. glutinosus hybridize at intermediate elevations. The lateral white spots of glutinosus decrease and the red on the legs of jordani increases with elevation from 685 m to 1,052 m. At the higher elevation, the proportion of animals scored as “pure” jordani declined significantly from 1974 to 1990, an indication that the hybrid zone is spreading upward. The rate of spread is too great to be explained by random diffusion, so selection for glutinosus characters is the best explanation. The rate of spread of the hybrid zone indicates that hybridization began 60–65 years ago, at the end of the time of intense timbering. Such human disturbances have caused hybridization in other organisms.     

THE SITE OF SYNTHESIS OF GANGLIOSIDES IN THE CHICK OPTIC SYSTEM

Abstract– In the retinas of 1-day-old chickens that received an intraocular injection of N-[³H]acetylmannosamine the labelling of N-acetylneuraminic acid and CMP-N-acetylneuraminic acid increased for at least 8 h and that of gangliosides for at least 24 h after injection. In the optic tectum contralateral to the injected eye at 8 h after the intraocular injection, the labelling of gangliosides exceeded the labelling of gangliosides in the ipsilateral tectum by approx 20-fold. In the contralateral tectum the highest concentration of labelled gangliosides was in subfractions enriched in synaptosomes and synaptic plasma membranes. No significant contralateral ipsilateral differences were found in the acid soluble substances of the tectum. In the optic tectum, labelled gangliosides appeared earlier in the neuronal perikarya than in synaptosomes when the injection was intracranial. Conversely, when the injection was intraocular the labelling appeared earlier in the synaptosomes than in the neuronal perikarya. The radioactivity pattern of the optic tectum gangliosides resembled the pattern of retina gangliosides when N-[³H]acetylmannosamine was injected intraocularly, but when N-[³H]acetylmannosamine was given intracerebrally the radioactivity pattern resembled that of optic tectum gangliosides. Intraocular injection of colchicine or vinblastine did not affect the labelling of retinal gangliosides from N-[³H]acetylmannosamine injected into the same eye but prevented the appearance of labelled gangliosides in the optic tectum. In vitro the ganglioside glycosylating activity of optic tectum synaptosomes and synaptic plasma membranes was between 6 and 10-fold lower than that found in the optic tectum neuronal perikarya. These findings support the notion that the main subcellular site of synthesis of neuronal gangliosides is in the neuronal perikarya, from which they are translocated to the nerve endings.     

THE EFFECT OF POLYCYTHAEMIC SERUM ON THE PROLIFERATION OF RAT BONE MARROW CELLS IN VITRO

The effect of experimental polycythaemia on the rate of proliferation of erythrocytic precursor cells was investigated by means of an in vitro technique. The serum obtained from polycythaemic rats was found to inhibit significantly ³H-thymidine incorporation in normal rat bone marrow cells in vitro, as compared with normal serum. Autoradiographic analysis revealed that this inhibition resulted from a reduction in the number of labelled bone marrow cells. The inhibition proved to be specific to the erythrocyte precursor cells; the labelling index was reduced in the erythrocytic cell population by 21–50% (P < 0.001) at different incubation times, while the effect on the granulocytic cell population was negligible. It is deduced that an inhibitor substance responsible for the effects observed is present in polycythaemic serum. It is proposed that this factor is the ‘erythrocytic chalone'. The results support the general view that triggering of stem cells is not the only mode of regulation of erythropoiesis, but that the rate of proliferation of the precursor cells in the erythron is also regulated.     

THE EFFECTS OF SOME NEWER ANAESTHETICS ON THE IN VITRO ACTIVITY OF GLUTAMATE DECARBOXYLASE AND GABA TRANSAMINASE IN CRUDE BRAIN EXTRACTS AND ON THE LEVELS OF AMINO ACIDS IN VIVO

—The effects of several anaesthetic and hypnotic compounds with well-defined excitatory side-effects on glutamate decarboxylase and γ-aminobutyric acid transaminase activity have been examined. The dissociative anaesthetics ketamine and γ-hydroxybutyric acid produced competitive inhibition of glutamate decarboxylase with respect to glutamate at concentrations which had no effect on GABA transaminase activity. The inhibitor constant (K_i) values were, ketamine: 13.3 mm , γ-hydroxybutyric acid; 8.8 mm . The steroid anaesthetic alphaxalone was also a potent competitive inhibitor of glutamate decarboxylase K_i= 4.1 mm ). Pentobarbitone, thiopentone and methohexitone non-competitively inhibited both glutamate decarboxylase and GABA-transaminase but only at high concentration (> 20 mm ). None of the drugs tested produced any significant change in brain GABA or glutamate levels following the injection of an hypnotic or anaesthetic dose. It is proposed that an alteration in the rate of GABA synthesis as a result of the inhibition of glutamate decarboxylase could explain the convulsive properties of the dissociative anaesthetics when given at high doses.