Dense-core vesicles in motor nerve terminals

Summary Motor nerve terminals on white and intermediate muscle fibers of the Atlantic hagfish (Myxine glutinosa, L.) contain translucent synpatic vesicles and about 1–2% dense-core vesicles. Terminals on red muscle fibers contain up to 40% dense-core vesicles with diameter 800–1100 Å. Examinations for formaldehyde-induced fluorescence indicate yellow fluorescence (5-HT ?) apparently corresponding with terminal axons on red muscle fibers in craniovelar muscles. Possibly red muscle fibers of Myxine receive monoaminergic innervation.The author is indebted to Dr. Finn Walvig, Biological station, University of Oslo, Drøbak, for supply of hagfishes.     

Sequestered actin in chick embryo fibroblasts

Chick embryo fibroblasts contain about 75-100 M unpolymerized actin and at least four proteins which can bind actin monomers, actin depolymerizing factor (ADF), gelsolin, profilin, and thymosin ₄ (T₄). Fibroblast extracts are analyzed by non-denaturing polyacrylamide gel electrophoresis and immunoblotting where most of the G-actin is detected as a complex with T₄. When fibroblast extracts are fractionated by gel filtration and the fractions are analyzed by PAGE and HPLC, most of the G-actin elutes in a peak that also contains T₄ at an overall molar ratio of 1.9:1 relative to actin. Gelsolin, profilin, and ADF are also detectable in the gel filtration eluate and at least partly coelute with actin, and account for only a minor fraction of the soluble actin pool. These observations indicate that under the growth conditions studied, T₄ is the major actin-sequestering protein in fibroblasts.     

Action of rat liver Galβ1-4GlcNAc α(2-6)-sialyltransferase on Manβ1-4GlcNAcβ-OMe,GalNAcβ1-4GlcNAcβ-OMe,Glcβ1-4GlcNAcβ-OMe and GlcNAcβ1-4GlcNAcβ-OMe as synthetic substrates

Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz¹H-NMR spectroscopy.Abbreviations 2D 2-dimensional - CMP cytidine 5-monophosphate - CMP-Neu5Ac cytidine 5-monophospho--N-acetylneuraminic acid - COSY correlation spectroscopy - DQF double quantum filtered - HOHAHA homonuclear Hartmann-Hahn - MLEV composite pulse devised by M. Levitt - Neu5Ac N-acetylneuraminic acid - Neu5Ac2en 2-deoxy-2,3-didehydro-N-acetylneuraminic acid     

A meta-analysis of frontalis EMG levels with biofeedback and alternative procedures

The lack of comparative reviews of the efficacy of EMG frontalis biofeedback versus alternative procedures for reduction of muscle tension prompted the present meta-analytic treatment of literature previously concluded to be equivocal. Twenty studies comparing EMG frontalis biofeedback with other tension-reduction procedures produced a total of 68 separate effect sizes suitable for meta-analysis. Differences between clinical and normal samples were nonsignificant, and data analyses revealed that EMG frontalis biofeedback was significantly superior to control (p<.05) but that alternative forms of muscle relaxation, while effective, did not reach statistical significance.     

Studies on aneuploids of Petunia

Summary The seven possible primary trisomics of Petunia (2 n= 14) located in the progenies of triploid, hypertriploid and hypotriploid plants were distinguished from one another and from diploid on the basis of cytological and morphological criteria. They were provisionally named as Oval, Semi, Slender, Pseudonormal, Arrow, Narrow and Giant. In three of the trisomics, the extra chromosome was identified for the first time at pachytene stage. Postpachytene studies revealed no precise relationship between the length of extra chromosome and the frequency of multiple association.     

17 β-Estradiol Enhances the Outgrowth and Survival of Neocortical Neurons in Culture

Results of this investigation demonstrate that exposure to 17 -estradiol differentially and significantly regulates cortical nerve cell outgrowth depending on the cortical region. Parietal and occipital neurons treated with 1 nM 17 -estradiol showed a greater magnitude of neuronal outgrowth whereas outgrowth of temporal cortex neurons was decreased in the presence of 1 nM 17 -estradiol. Frontal cortex neurons showed a consistent enhancement of neuronal outgrowth that did not reach statistical significance. The dose response profile for 17 -estradiol regulation of the macromorphological features exhibited a bimodal dose response relationship whereas the dose response profile for 17 -estradiol regulation of the micromorphological features exhibited a dose response more characteristic of an inverted V-shaped function. An antagonist to the NMDA receptor antagonist, AP5, abolished the growth promoting effect of 17 -estradiol whereas the nuclear estrogen receptor antagonist ICI 182,780 did not. Lastly, neocortical neurons exposed to 17 -estradiol exhibited greater viability and survival than control neurons over a two week period. These data indicate that 17 -estradiol can enhance the growth and viability of select populations of neocortical neurons and that the growth promoting effects of 17 -estradiol can be blocked by an antagonist to the NMDA glutamate receptor and not by an antagonist to the estrogen nuclear receptor.     

Pullulan production from brewery wastes by Aureobasidium pullulans

The production of pullulan from brewery wastes by Aureobasidium pullulans in shake flask culture was investigated. The maximum pullulan concentration (6.0g/l) was obtained after 72h of fermentation. The external addition of nutrients into the spent grain liquor improved significantly the production of pullulan. In this case, the highest values of pullulan concentration (11.0±0.5g/l), pullulan yield (48.2±1.5%), and sugar utilization (99.0±0.5%) were obtained in the medium (pH 6.5–7.5) supplemented with K₂HPO₄ 0.5%, l-glutamic acid 1%, olive oil 2.5%, and Tween 800.5%.     

Ovarian development in Culex nigripalpus and its implication for disease transmission

Ovarian development was investigated in wild and colonized Culex nigripalpus Theobald females. Blood-seeking females with morphologically distinct nulliparous, parous and resorbed ovarian follicles (as opposed to females with degenerating follicles) were collected from the field all year, indicating year around gonoactivity. During the cooler months a larger number of females with resorbed follicles were collected from the field than in warmer months. Laboratory experiments showed that resorbed ovarian follicles occurred in sucrose fed females when deprived of a blood meal after emergence. These resorbed ovarian follicles were functional, since most of them began to develop and mature after the females took a blood meal to repletion. Among females fed a partial blood meal, some did not begin ovarian development and, therefore, exhibited gonotrophic dissociation. Females fed partial blood meals had similar patterns of ovarian development, irrespective of temperature at which they were maintained. Implications of occurrence of females with resorbed ovarian follicles and disease transmission are discussed.Supported in part by National Institutes of Health Research Grants No. A1-06587 and RR-07021. A contribution of the Florida Medical Entomology Laboratory, Vero Beach, Florida, Florida Agriculture Experimental Station Journal Series No. 2367     

γδ T-cell receptor repertoire in human peripheral blood and thymus

T-cell clones expressing the T-cell receptor (Tcr) were generated from peripheral blood lymphocytes (PBLs) and from a thymus sample. In the panel of ten thymus-derived clones, four Tcr phenotypes [as defined by the reaction of monoclonal antibodies (mAbs) directed against known V and V regions] were identified. All the clones lacked expression of the V3 V region, while seven clones were V1+ . V1 was found in combination with V9 or with undefined VVregions. In addition, two other Tcr phenotypes were identified on these clones: V9⁺ V1^– V3^– and V9^– V1^– V3^– One of the clones expressed CD4 and another was CD8positive. The remaining clones were CD4^– CD8^–. In the panel of 76 PBL-derived, Tcr-bearing clones, five Tcr phenotypes could be identified. In contrast to the thymus-derived clones, 30% of the clones were V3⁺ whereas V1 was expressed by a minority of the clones only. One clone was CD4-positive and approximately 30% of the clones were CD8-positive. Four of the five mAb-defined Tcr phenotypes could be identified on both thymus and PBL-derived T-cell clones. However, biochemical analysis of the Tcrs demonstrates differences in the usage of Ct- and C2-encoded y chains by T cells derived from the thymus and PBLs. The results therefore indicate that, at the clonal level, similarities and differences exist between the Tcr repertoires expressed in the thymus and by PBLs. Furthermore, they indicate that combinatorial Tcr heterogeneity is larger than has so far been described. The receptor diversity, combined with the potential of Tcr+ cells to express CD4 or CD8, indicates that these cells are a heterogeneous population that might mediate a number of immune functions.     

Analysis of primary food sources and trophic relationships of aquatic animals in a mangrove-fringed estuary,Khung Krabaen Bay (Thailand) using dual stable isotope techniques

Stable carbon (¹³C) and nitrogen (¹⁵N) isotopes were used to elucidate primary food sources and trophic relationships of organisms in Khung Krabaen Bay and adjacent offshore waters. The three separate sampling sites were mangroves, inner bay and offshore. The ¹³C values of mangrove leaves were –28.2 to –29.4, seagrass –10.5, macroalgae –14.9 to –18.2, plankton –20.0 to –21.8, benthic detritus –15.1 to –26.3, invertebrates –16.5 to –26.0, and fishes –13.4 to –26.3. The ¹⁵N values of mangrove leaves were 4.3 to 5.7, seagrass 4.3, macroalgae 2.2 to 4.4, plankton 5.7 to 6.4 , benthic detritus 5.1 to 5.3, invertebrates 7.2 to 12.2 , and fishes 6.3 to 15.9. The primary producers had distinct ¹³C values. The ¹³C values of animals collected from mangroves were more negative than those of animals collected far from shore. The primary carbon sources that support food webs clearly depended on location. The contribution of mangroves to food webs was confined only to mangroves, but a mixture of macroalgae and plankton was a major carbon source for organisms in the inner bay area. Offshore organisms clearly derived their carbon through the planktonic food web. The ¹⁵N values of consumers were enriched by 3–4 relative to their diets. The ¹⁵N data suggests that some of aquatic animals had capacity to change their feeding habits according to places and availability of foods and as a result, individuals of the same species could be assigned to different trophic levels at different places.     

Short- and long-term effects of ACTH on the adrenal zona glomerulosa of the rat

Summary Short-term ACTH treatment provoked a decrease in volume of the lipid-droplet compartment in rat zona glomerulosa cells, and a rise in plasma and intracellular concentrations of corticosterone and aldosterone. It enhanced activities of 3-hydroxysteroid dehydrogenase (3HSD), 11-hydroxylase (11OH) and 18-hydroxylase (18OH). Long-term ACTH administration produced a hypertrophy of the zona glomerulosa and its parenchymal cells, a result of the increase in volume of the smooth endoplasmic reticulum and the mitochondrial compartment. The surface area per cell of mitochondrial inner membranes increased; the tubular cristae were transformed into a homogeneous population of vesicles. The plasma and intracellular concentrations of corticosterone further increased, whereas those of aldosterone fell below basal levels (the aldosterone-escape phenomenon). The activities of 3HSD and 11OH were enhanced, that of 180H decreased. Therefore, ACTH stimulates zona glomerulosa growth and transforms parenchymal elements into zona fasciculata celltypes. Cyanoketone nullified acute ACTH effects on plasma and intracellular concentrations of corticosterone and aldosterone, but did not affect the activities of 11OH and 18OH. Chronic ACTH treatment produced similar results, although 18OH activity was not suppressed. The mechanism underlying the aldosterone-escape phenomenon may thus involve a rise in the intracellular concentration of corticosterone, caused by the enhanced synthesis and activation of 3HSD and 11OH.     

Interpretation of metameric architecture in dominant shrubs of the Chilean matorral

Summary The seasonal progression of phenophases in 21 shrub species of the Chilean matorral was analyzed. Five modules or basic units that are responsible for the aboveground architecture of the plants were characterized. These modules appear to be organized in seven different spatial arrangements. In drought-deciduous species a module type with an absolute short shoot with limited apical growth, leafy or spiny, predominated. In evergreen species long shoot and temporal leafy short shoot module types were more frequent. The spatial arrangement of morphologically different modules and the temporal sequence of their formation allow a dynamic interpretation of the modular architecture of the plants.     

The effect of monoterpenes on astaxanthin production by a mutant ofPhaffia rhodozyma

Summary The total pigment and astaxanthin content ofPhaffia rhodozyma increased with increasing concentrations -pinene up to 500 l -pinene/l. Above this concentration the total pigment and astaxanthin content as well as the biomass production decreased. The addition of 500 l -pinene/l increased the total pigment content from 1652 g/g to 2201 g/g and the astaxanthin content from 1554 g/g to 1883 g/g. A sharp decrease in maximum specific growth rate occurred above 150 l -pinene/l.     

Synthetic substrate analogues for UDP-GlcNAc: Manα1-6R β(1-2)-N-acetylglucosaminyltransferase II. Substrate specificity and inhibitors for the enzyme

UDP-GlcNAc: Man1-6R (1-2)-N-acetylglucosaminyltransferase II (GlcNAc-T II; EC 2.4.1.143) is a key enzyme in the synthesis of complexN-glycans. We have tested a series of synthetic analogues of the substrate Man1-6(GlcNAc1-2Man1-3)Man-O-octyl as substrates and inhibitors for rat liver GlcNAc-T II. The enzyme attachesN-acetylglucosamine in 1-2 linkage to the 2-OH of the Man1-6 residue. The 2-deoxy analogue is a competitive inhibitor (K _i=0.13mm). The 2-O-methyl compound does not bind to the enzyme presumably due to steric hindrance. The 3-, 4- and 6-OH groups are not essential for binding or catalysis since the 3-, 4- and 6-deoxy and -O-methyl derivatives are all good substrates. Increasing the size of the substituent at the 3-position to pentyl and substituted pentyl groups causes competitive inhibition (K _i=1.0–2.5mm). We have taken advantage of this effect to synthesize two potentially irreversible GlcNAc-T II inhibitors containing a photolabile 3-O-(4,4-azo)pentyl group and a 3-O-(5-iodoacetamido)pentyl group respectively. The data indicate that none of the hydroxyls of the Man1-6 residue are essential for binding although the 2- and 3-OH face the catalytic site of the enzyme. The 4-OH group of the Man-O-octyl residue is not essential for binding or catalysis since the 4-deoxy derivative is a good substrate; the 4-O-methyl derivative does not bind. This contrasts with GlcNAc-T I which cannot bind to the 4-deoxy-Man- substrate analogue. The data are compatible with our previous observations that a bisectingN-acetylglucosamine at the 4-OH position prevents both GlcNAc-T I and GlcNAc-T II catalysis. However, in the case of GlcNAc-T II, the bisectingN-acetylglucosamine prevents binding due to steric hindrance rather than to removal of an essential OH group. The 3-OH of the Man1-3 is an essential group for GlcNAc-T II since the 3-deoxy derivative does not bind to the enzyme. The trisaccharide GlcNAc1-2Man1-3Man-O-octyl is a good inhibitor (K _i=0.9mm). The above data together with previous studies indicate that binding of the GlcNAc1-2Man1-3Man- arm of the branched substrate to the enzyme is essential for catalysis. Abbreviations: GlcNAc-T I, UDP-GlcNAc:Man1-3R (1-2)-N-acetylglucosaminyltransferase I (EC 2.4.1.101); GlcNAc-T II, UDP-GlcNAc:Man1-6R (1-2)-N-acetylglucosaminyltransferase II (EC 2.4.1.143); MES, 2-(N-morpholino)ethane sulfonic acid monohydrate.     

Dynamics of the cytoskeleton of epidermal cells in situ and in culture

Summary The cytoskeleton of primary tissue-culture cells from the epidermis of Xenopus laevis tadpoles was investigated by phase-contrast, immunofluorescence, and electron microscopy. The connection between the arrangement of different types of filaments and the mechanical properties of the epidermis is discussed. The bilayered epidermis attains stability from thick bundles of tonofilaments interconnecting the basal desmosomes. Twisting of tonofilaments around each other can explain the occurrence of elastic filamentous curls forming a meshwork braced between rows of small desmosomes in the apical region of the epidermis. Actin is arranged as a diffuse meshwork and sometimes forms bundles intermingling with tonofilament bundles. Surface membranes and rows of small desmosomes are delineated by actin and contain -actinin. Actin raises the tension for rounding and spreading of cells. Microtubules stabilize already well-developed lamellae.     

Contextualizing Images in Dreams and Daydreams

A contextualizing image (CI) is a powerful central image of a dream which appears to contextualize (provide a picture-context for) the dreamer's emotion. For instance, dreamers who have experienced any serious traumatic event sometimes dream, I was overwhelmed by a tidal wave. This appears to picture their feeling of terror and/or vulnerability.A scoring system for CIs is examined here and is applied to dreams and daydreams supplied by 40 students. Two raters scoring dreams on a blind basis showed good inter-rater reliability. Recent dreams were shown to have more as well as more intense CIs than recent daydreams; likewise, dreams that stand out had more intense CIs than daydreams that stand out. Students with thin boundaries had more and more intense CIs than students with thick boundaries in their recent dreams and nightmare, but not so clearly in dreams and nightmares that stand out. The emotions judged as contextualized by the powerful images tended towards fear/terror and helplessness/vulnerability in dreams (especially in dreams that stand out) whereas emotions contextualized by images in daydreams showed a wide range with no clusters.     

Plant regeneration from embryo-derived callus of oil palm – the effect of exogenous polyamines

Regeneration in oil palm was achieved through somatic embryogenesis/organogenesis from embryo-derived callus. Callus was induced from mature embryos of the cross 281 (D)×18 (P) on modified MS medium supplemented with 2,4-D (113.12 M) and 2-iP (14.76 M). The embryogenic calluses obtained were transferred to Blaydes medium supplemented with 2,4-D (0.045 M) and one of the following growth regulators: TDZ (4.54 M), zeatin riboside (2.85 M), putrescine (1 mM) and spermine (100 M). Secondary somatic embryogenesis was found to occur in media supplemented with polyamines. The efficiency of formation of somatic embryos, secondary somatic embryos and shoot meristemoids were significantly higher in putrescine containing medium. Histological studies were also undertaken.     

Ethnocentricity and the social construction of ‘mass hysteria’

This study provides a critical historical review and analysis of the variety of human expressions which have been erroneously labeled under the grandiose category mass hysteria. It is argued that Western science reductionist approaches to the classification of mass hysteria treat it as an entity to be discovered transculturally, and in their self-fulfilling search for universals systematically exclude what does not fit within the autonomous parameters of its Western-biased culture model, exemplifying what Kleinman (1977) terms a category fallacy. As a result of objectivist methodologies, the etiology of actions labeled as mass hysteria is typically viewed as deviant, irrational or abnormal behavior resulting from a malfunctioning proper social order. However, what constitutes the correct social order is a function of a researcher's historical sociocultural and/or scientific milieu. This study reviews the problem, advocating Geertz's (1973) culturally relativistic approach to understanding various cross-cultural behavior that is sensitive to and tolerant of the unique context and milieu of participants. Mass or epidemic hysteria is viewed as an invention of Western psychiatry and should be abandoned and replaced with the term collective exaggerated emotions. Instead of attempting to discover a neatly packaged, unitary external disease entity, the focus of a meaning-oriented approach emphasizes the deciphering of foreign realities, semantic networks and symbol systems.     

Secondary structure determination by NMR spectroscopy of an immunoglobulin-like domain from the giant muscle protein titin

Summary We present the complete ¹⁵N and ¹H NMR assignment and the secondary structure of an immunoglobulin-like domain from the giant muscle protein titin. The assignment was obtained using homonuclear and ¹⁵N heteronuclear 2D and 3D experiments. The complementarity of 3D TOCSY-NOESY and 3D ¹⁵N NOESY-HSQC experiments, using WATERGATE for water suppression, allowed an efficient assignment of otherwise ambiguous cross peaks and was helpful in overcoming poor TOCSY transfer for some amino acids. The secondary structure is derived from specific NOEs between backbone - and amide protons, secondary chemical shifts of -protons and chemical exchange for the backbone amide protons. It consists of eight -strands, forming two -sheets with four strands each, similar to the classical -sandwich of the immunoglobulin superfamily, as previously predicted by sequence analysis. Two of the -strands are connected by type II -turns; the first -strand forms a -bulge. The whole topology is very similar to the only intracellular immunoglobulin-like domain for which a structure has been determined so far, i.e., telokin.     

Genetic variation detected by use of the M13 “DNA fingerprint” probe in Malus,Prunus, and Rubus (Rosaceae)

Summary Recently, DNA fingerprints have been reported in a wide array of organisms. We used the M13 repeat probe on several genera and species in the angiosperm family Rosaceae. Four apple cultivars could be differentiated when any one of five restriction enzymes was used to analyze minisatellite DNA. Similarly, four individual trees of Prunus serotina (black cherry) exhibited different fingerprints with each of four enyzmes. A total of 14 Rubus (blackberries and raspberries) plants representing four species were investigated with two enzymes. Extensive inter-and intraspecific variation was found. However, some closely growing plants had identical fingerprints, probably due to their being derived through vegetative propagation.