Sympathetic Tone Induced by High Acoustic Tempo Requires Fast Respiration

Many studies have revealed the influences of music, and particularly its tempo, on the autonomic nervous system (ANS) and respiration patterns. Since there is the interaction between the ANS and the respiratory system, namely sympatho-respiratory coupling, it is possible that the effect of musical tempo on the ANS is modulated by the respiratory system. Therefore, we investigated the effects of the relationship between musical tempo and respiratory rate on the ANS. Fifty-two healthy people aged 18–35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome and they listened to simple drum sounds with a constant tempo. We varied the respiratory rate—acoustic tempo combination. The respiratory rate was controlled at 15 or 20 cycles per minute (CPM) and the acoustic tempo was 60 or 80 beats per minute (BPM) or the environment was silent. Electrocardiograms and an elastic chest band were used to measure the heart rate and respiratory rate, respectively. The mean heart rate and heart rate variability (HRV) were regarded as indices of ANS activity. We observed a significant increase in the mean heart rate and the low (0.04–0.15 Hz) to high (0.15–0.40 Hz) frequency ratio of HRV, only when the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the effect of acoustic tempo on the sympathetic tone is modulated by the respiratory system.     

Differentiation of Langerhans Cells from Interdigitating Cells Using CD1a and S-100 Protein Antibodies

The present study shows that Langerhans cells can be differentiated from Interdigitating cells at the light microscopic level. Superficial lymph nodes and skin taken from necropsies and the lymph nodes of dermatopathic lymphadenopathy (DPL) were used for this experiment. Sections of lymph node and skin were embedded using the acetone, methyl benzoate and xylene (AMeX) method and dendritic cells were immunostained with anti S-100 protein antibody (S-100, and OKT-6 (CD1a) using the restaining method. Langerhans cells in the skin were positive for both CD1a and S-100. Dendritic cells positive for both CD1a and S-100, and dendritic cells positive for S-100, but not for CD1a were observed in superficial lymph nodes. In normal superficial lymph nodes, there were more interdigitating cells than Langerhans cells. The majority of the dendritic cells in the DPL were Langerhans cells. We conclude that the S-100 and CD1a positive cells are Langerhans cells, and the S-100 positive-CD1a negative cells are interdigitating cells.     

Characterization of Flavin-Containing Opine Dehydrogenase from Bacteria

Opines, in particular nopaline and octopine, are specific compounds found in crown gall tumor tissues induced by infections with Agrobacterium species, and are synthesized by well-studied NAD(P)H-dependent dehydrogenases (synthases), which catalyze the reductive condensation of α-ketoglutarate or pyruvate with L-arginine. The corresponding genes are transferred into plant cells via a tumor-inducing (Ti) plasmid. In addition to the reverse oxidative reaction(s), the genes noxB-noxA and ooxB-ooxA are considered to be involved in opine catabolism as (membrane-associated) oxidases; however, their properties have not yet been elucidated in detail due to the difficulties associated with purification (and preservation). We herein successfully expressed Nox/Oox-like genes from Pseudomonas putida in P. putida cells. The purified protein consisted of different α-, β-, and γ-subunits encoded by the OdhA, OdhB, and OdhC genes, which were arranged in tandem on the chromosome (OdhB-C-A), and exhibited dehydrogenase (but not oxidase) activity toward nopaline in the presence of artificial electron acceptors such as 2,6-dichloroindophenol. The enzyme contained FAD, FMN, and [2Fe-2S]-iron sulfur as prosthetic groups. On the other hand, the gene cluster from Bradyrhizobium japonicum consisted of OdhB ₁ -C-A-B ₂, from which two proteins, OdhAB₁C and OdhAB₂C, appeared through the assembly of each β-subunit together with common α- and γ-subunits. A poor phylogenetic relationship was detected between OdhB₁ and OdhB₂ in spite of them both functioning as octopine dehydrogenases, which provided clear evidence for the acquisition of novel functions by “subunit-exchange”. To the best of our knowledge, this is the first study to have examined flavin-containing opine dehydrogenase.     

Matrix Gla protein C-terminal region binds to vitronectin. Co-localization suggests binding occurs during tissue development.

Matrix Gla protein (MGP) regulates calcification in cartilage and arteries. MGP synthesis during embryonic development and its binding and regulation of growth factors and morphogens of the TGF-beta/BMP superfamily suggests that it has additional functions. Assay by far-western gel overlays and gel filtration shift shows MGP binds vitronectin. Binding is saturable and consistent with a single class of binding sites. MGP binds to vitronectin but not collagen, fibromodulin, heparin, osteocalcin, chondroitin sulfate, laminin, ovalbumin or albumin. We have identified a vitronectin binding site within a 17-amino acid peptide 61-77 near the carboxyl-terminus that corresponds to a naturally occurring MGP C-terminus. MGP and the 61-77 MGP peptide also binds to fibronectin. MGP and vitronectin are focally co-localized in embryonic tissues. Co-localization in vivo suggests that the MGP and vitronectin interactions may modify cell-matrix interactions. Alternatively, vitronectin-bound MGP may have altered function for modulating BMP2 or TGF-beta activity. The current study demonstrates that MGP has a novel binding activity for vitronectin, an extracellular protein that promotes cell-matrix interactions and regulates coagulation.     

VARIATION IN THE ULTRASTRUCTURE OF THE BIFLAGELLATE MOTILE CELLS OF SIX UNICELLULAR GENERA OF THE CHLAMYDOMONADALES AND CHLOROCOCCALES (CHLOROPHYCEAE), WITH EMPHASIS ON THE FLAGELLAR APPARATUS

The ultrastructural features of the biflagellate motile cells of six different species of the Chlorophyceae, namely Dunaliella lateralis (Polyblepharidaceae, Chlamydomonadales), Chlorococcum hypnosporum, Spongiochloris spongiosa, Protosiphon botryoides (Chlorococcaceae, Chlorococcales), Tetracystis aeria and Pseudotetracystis terrestris (Tetracystidaceae, Chlorococcales), were examined with an emphasis on the flagellar apparatus (FA). They have different vegetative characteristics, such as, being motile or nonmotile, variations in chloroplast morphology, possession of one or more nuclei, and reproductive features such as formation of tetrahedral tetrads, and naked or walled zoospores. Ultrastructural differences amongst reproductive cells of the six species include variations in cell surface structure, basal body to basal body angle, beamlike extensions of the distal fiber, extensive connections of the proximal sheath between basal bodies, two-membered rootlets, striated microtubule-associated components, two-membered rootlet-nucleus and/or mitochondria connections, X-membered rootlets, connections of rootlets and basal bodies, rhizoplasts and accessory basal bodies. All six species possess pyrenoids penetrated by thylakoid membranes, and the FA typical of the Chlorophyceae (sensu Mattox and Stewart, 1984). These six species should be divided into two groups. The first includes D. lateralis, C. hypnosporum, and T. aeria, in which accessory basal bodies are present, the basal body to basal body angle is relatively fixed, and a cell wall or surface coat is present. The second group includes Ps. terrestris, S. spongiosa, and Pr. botryoides, in which accessory basal bodies are absent, the basal body to basal body angle is variable and the zoospores are naked.     

Mechanisms of modulation of neuronal nicotinic receptors by substance P and OAG

Substance P is known to modulate neuronal nicotinicacetylcholine receptors (nAChRs) in the sympathetic nervous system.There are two conflicting proposals for the mechanism of this effect, an indirect action mediated by protein kinase C (PKC) and a direct interaction with receptor subunits. We studied the mechanisms of thiseffect in PC-12 cells. Substance P enhanced the decay of thenicotine-induced whole cell current. This effect was fast in its onsetand was not antagonized by guanosine5'-O-(2-thiodiphosphate), a G protein blocker, orstaurosporine, a nonselective PKC blocker. Staurosporine failed toreverse the inhibition by 1-oleoyl-2-acetyl-sn-glycerol (OAG), a synthetic diacylglycerol analog known to activate PKC. Theinhibitory effects of the peptide and OAG were preserved in excisedpatches, but substance P applied to the extra patch membrane wasineffective in the cell-attached patch configuration. We conclude thatsubstance P modulates neuronal nAChRs most likely by direct interactions with the receptors but independently from activation ofPKC or G proteins and that PKC does not participate in modulation by OAG.

     

Requirement of caspase and p38MAPK activation in zinc-induced apoptosis in human leukemia HL-60 cells.

Zinc (Zn), an endogenous regulator of apoptosis, and has abilities both to induce apoptosis and inhibit the induction of apoptosis via the modulation of caspase activity. Due to the multifunctions of Zn, the intracellular Zn level is strictly regulated by a complex system in physiological and pathological conditions. The commitment of Zn to the regulation of apoptosis is not fully understood. In the present study, we investigated the role of intracellular Zn level in the induction of apoptosis in human leukemia cells (HL-60 cells) using a Zn ionophore [pyrithione (Py)]. Treatment of HL-60 cells with Zn for 6 h in the presence of Py (1 micro m) exhibited cytotoxicity in a Zn dose-dependent manner (25-200 micro m). Necrotic cells, assayed by trypan blue permeability, increased in number in a Zn dose-dependent fashion (50-100 micro m), but the appearance of apoptotic cells, assayed by formation of a DNA ladder and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling method, peaked at 25 micro m, suggesting the dependence of intracellular Zn level on the execution of apoptosis. In fact, treatment with Py resulted in increases in intracellular Zn levels, and N,N,N',N'-tetrakis (2-pyridylmethyl)ethylenediamine, a cell-permeable Zn chelator, inhibited DNA ladder formation induced by Py/Zn treatment (1 micro m Py and 25 micro m Zn). Py/Zn treatment activated the caspases, as assessed by the proteolysis of poly(ADP-ribose) polymerase (PARP), which is a substrate of caspase, and activated p38 mitogen-activated protein kinase (p38MAPK), which is a transducer of apoptotic stimuli to the apparatus of the apoptosis execution. Z-Asp-CH2-DCB, a broad-spectrum inhibitor of caspase, attenuated proteolysis of PARP and DNA ladder formation by Py/Zn, indicating that apoptosis induced by Py/Zn is mediated by caspase activation. The p38MAPK-specific inhibitor SB203580 also inhibited induction of apoptosis by Py/Zn. Although SB203580 suppressed the proteolysis of PARP, Z-Asp-CH2-DCB did not inhibit the phosphorylation of p38MAPK, raising the possibility that apoptosis triggered by Py/Zn might be mediated by the p38MAPK/caspase pathway.     

Seasonal succession of a microphagotroph community in a small pond during litter decomposition

Temporal dynamics of a lentic microphagotroph community were studied during leaf litter decomposition from December to May. Small plastic vessels containing leaf litter were placed on a pond bottom. They were sampled periodically to collect microphagotrophs. Three abiotic factors and abundance of two food items were also measured to analyze the autogenic and allogenic phenomena during a microphagotroph succession. Three behavior types were recognized in dominant taxa: a free-swimming type, a vagile (creeps on substratum, sometimes swims) type, and a voluntarily fixed type. Dominant taxa changed from the free-swimming to the vagile type up to mid-March, and the reverse change occurred from mid-April. Principal component analysis (PCA) indicated four factors affecting the dynamics of the community: water temperature as a seasonal factor, detritus volume on the litter surface as a habitat factor, and densities of bacteria and small flagellates as food factors. Taxa replacement appeared to occur through two mechanisms. (1) Dominance of small holotrichs, a free-swimming type, was brought about by a high bacterial density caused by seasonal events, i.e., leaf fall in December and detritus formation by litter feeders in mid-April. This is an allogenic aspect of community dynamics. (2) The free-swimming type was replaced by the vagile one during the period with high taxa diversity. This replacement occurred through intertaxa competition for scarce food and/or selective predation by larger microphagotrophs. It is an autogenic process within the community.