Field survey and resin casting of <Emphasis Type="Italic">Gymnogobius macrognathos</Emphasis> spawning nests in the Tatara River,Fukuoka Prefecture,Japan

We investigated the spawning nests of Gymnogobius macrognathos on a tidal flat in the Tatara River, Fukuoka Prefecture, Japan. Digging uncovered 19 spawning nests. The number of eggs and the standard length of the guarding male were positively correlated. Nine spawning nests were examined using in situ resin casting. All casts had structures characteristic of callianassid shrimp burrows and were most likely those of Nihonotrypaea japonica. Spawning nests had significantly greater average diameters than shrimp burrow openings and may have been widened by G. macrognathos.     

Migration Behavior of Granule Cell Neurons in Cerebellar Cultures. II. An Electron Microscopic Study

We examined the fine structure of migrating granule cell neurons in cerebellar microexplant cultures. Radially migrating bipolar cells extended microspikes or small filopodia from their soma and processes and frequently made contact with neighboring cells. These microspikes contained microfilaments but no microtubules. At the later phase of the migration, in which they had symmetrical bipolar long processes, filopodia extending from perikarial region of cells contained microtubules, suggesting that they are precursors of the future thick perpendicular processes. When cell bodies changed orientation from radial to perpendicular, microtubules that were nucleated from perinuclear centrioles frequently extended into both thick radial and perpendicular processes from the perikarial region. Bundles of 10nm intermediate filaments also appeared in these processes. During migration by the perpendicular contact guidance, many filopodia extending from both the thick leading processes and thin trailing processes made close contacts with the radial parallel neurite. These findings suggest that; 1) The direct contact of the filopodia from both the growth cones and their processes of the granule cells to the neurite bundle plays roles in both the parallel and perpendicular contact guidances. 2) The spacial and temporal changes of cytoskeletons and the association of microtubules with perinuclear centrioles are important for the formation of perpendicular processes and initiation of the perpendicular contact guidance.     

Presence of Neutrophil Extracellular Traps and Citrullinated Histone H3 in the Bloodstream of Critically Ill Patients

Neutrophil extracellular traps (NETs), a newly identified immune mechanism, are induced by inflammatory stimuli. Modification by citrullination of histone H3 is thought to be involved in the in vitro formation of NETs. The purposes of this study were to evaluate whether NETs and citrullinated histone H3 (Cit-H3) are present in the bloodstream of critically ill patients and to identify correlations with clinical and biological parameters. Blood samples were collected from intubated patients at the time of ICU admission from April to June 2011. To identify NETs, DNA and histone H3 were visualized simultaneously by immunofluorescence in blood smears. Cit-H3 was detected using a specific antibody. We assessed relationships of the presence of NETs and Cit-H3 with the existence of bacteria in tracheal aspirate, SIRS, diagnosis, WBC count, and concentrations of IL-8, TNF-α, cf-DNA, lactate, and HMGB1. Forty-nine patients were included. The median of age was 66.0 (IQR: 52.5–76.0) years. The diagnoses included trauma (7, 14.3%), infection (14, 28.6%), resuscitation from cardiopulmonary arrest (8, 16.3%), acute poisoning (4, 8.1%), heart disease (4, 8.1%), brain stroke (8, 16.3%), heat stroke (2, 4.1%), and others (2, 4.1%). We identified NETs in 5 patients and Cit-H3 in 11 patients. NETs and/or Cit-H3 were observed more frequently in “the presence of bacteria in tracheal aspirate” group (11/22, 50.0%) than in “the absence of bacteria in tracheal aspirate” group (4/27, 14.8%) (p<.01). Multiple logistic regression analysis showed that only the presence of bacteria in tracheal aspirate was significantly associated with the presence of NETs and/or Cit-H3. The presence of bacteria in tracheal aspirate may be one important factor associated with NET formation. NETs may play a pivotal role in the biological defense against the dissemination of pathogens from the respiratory tract to the bloodstream in potentially infected patients.     

Persistent Calcium Inward Current in Internally Perfused Snail Neuron

The inactivation process of the calcium current (ICa) was investigated in a molluscan neuron which was perfused intracellularly and voltage-clamped using a suction pipette technique. The decay phase of the ICa contained a very slowly inactivated component (persistent inward current; PIC). The decay time constant of this component was over 10 sec. An increase in the amplitude of the ICa or the intracellular Ca2+ concentration caused a decrease in the decay time constant of the PIC. Replacing Ba2+ with extracellular Ca2+ increased the decay time constant of the PIC. The differences in the amplitude and the decay kinetics between the ICa and the IBa resulted from changes in the amplitude and the decay time constant of the PIC. These observations support the conclusion that the inactivation of the PIC is calcium dependent [Chad, J., Eckert, R., and Ewald, D. (1984). J. Physiol. (Lond.) 347:279-300].     

Protective Effect of Oren-gedoku-to Against Induction of Neuronal Death by Transient Cerebral Ischemia in the C57BL/6 Mouse

We examined the neuroprotective effects of oren-gedoku-to (TJ15), a herbal medicine, after transient forebrain ischemia. Transient forebrain ischemia was induced by occlusion of both common carotid arteries for 15 min in C57BL/6 mice treated with TJ15. In the control ischemic group without TJ15 treatment, histologic examination of brain tissue collected seven days after reperfusion showed death of pyramidal cells in CA2-3 area of the hippocampus, unilaterally or bilaterally. In mice treated with oral TJ15 (845 mg/kg/day) for five weeks, the frequency of ischemic neuronal death was significantly lower. Immunohistochemistry for Cu/Zn-superoxide dismutase (Cu/Zn-SOD) showed strongly reactive astrocytes in the hippocampus of ischemic mice treated with TJ15. Damage to nerve cells by free radicals plays an important role in the induction of neuronal death by ischemia-reperfusion injury. Our results suggest that TJ15 protects against ischemic neuronal death by increasing the expression of Cu/Zn-SOD and suggest that oren-gedoku-to reduces the exposure of hippocampal neurons to oxidative stress.     

Are tyrosine residues involved in the photoconversion of the water‐soluble chlorophyll‐binding protein of Chenopodium album?

Non‐photosynthetic and hydrophilic chlorophyll (Chl) proteins, called water‐soluble Chl‐binding proteins (WSCPs), are distributed in various species of Chenopodiaceae, Amaranthaceae, Polygonaceae and Brassicaceae. Based on their photoconvertibility, WSCPs are categorised into two classes: Class I (photoconvertible) and Class II (non‐photoconvertible). Chenopodium album WSCP (CaWSCP; Class I) is able to convert the chlorin skeleton of Chl a into a bacteriochlorin‐like skeleton under light in the presence of molecular oxygen. Potassium iodide (KI) is a strong inhibitor of the photoconversion. Because KI attacks tyrosine residues in proteins, tyrosine residues in CaWSCP are considered to be important amino acid residues for the photoconversion. Recently, we identified the gene encoding CaWSCP and found that the mature region of CaWSCP contained four tyrosine residues: Tyr13, Tyr14, Tyr87 and Tyr134. To gain insight into the effect of the tyrosine residues on the photoconversion, we constructed 15 mutant proteins (Y13A, Y14A, Y87A, Y134A, Y13‐14A, Y13‐87A, Y13‐134A, Y14‐87A, Y14‐134A, Y87‐134A, Y13‐14‐87A, Y13‐14‐134A, Y13‐87‐134A, Y14‐87‐134A and Y13‐14‐87‐134A) using site‐directed mutagenesis. Amazingly, all the mutant proteins retained not only chlorophyll‐binding activity, but also photoconvertibility. Furthermore, we found that KI strongly inhibited the photoconversion of Y13‐14‐87‐134A. These findings indicated that the four tyrosine residues are not essential for the photoconversion.     

NIR fluorescent ytterbium compound for in vivo fluorescence molecular imaging

We have developed a new NIR fluorescent probe based on an ytterbium(III) (E)‐1‐(pyridin‐2‐yl‐diazenyl)naphthalen‐2‐ol (PAN) complex. This probe emits near‐infrared luminescence derived from the Yb ion through excitation of the PAN moiety with visible light (λ_ex = 530 nm, λ_em = 975 nm). The results support the possible utility of the probe for in vivo fluorescence molecular imaging. Copyright © 2009 John Wiley & Sons, Ltd.     

Antinociceptive effect of 7-hydroxymitragynine in mice: Discovery of an orally active opioid analgesic from the Thai medicinal herb Mitragyna speciosa

Mitragynine is an indole alkaloid isolated from the Thai medicinal plant Mitragyna speciosa. We previously reported the morphine-like action of mitragynine and its related compounds in the in vitro assays. In the present study, we investigated the opioid effects of 7-hydroxymitragynine, which is isolated as its novel constituent, on contraction of isolated ileum, binding of the specific ligands to opioid receptors and nociceptive stimuli in mice. In guinea-pig ileum, 7-hydroxymitragynine inhibited electrically induced contraction through the opioid receptors. Receptor-binding assays revealed that 7-hydroxymitragynine has a higher affinity for micro-opioid receptors relative to the other opioid receptors. Administration of 7-hydroxymitragynine (2.5-10 mg/kg, s.c.) induced dose-dependent antinociceptive effects in tail-flick and hot-plate tests in mice. Its effect was more potent than that of morphine in both tests. When orally administered, 7-hydroxymitragynine (5-10 mg/kg) showed potent antinociceptive activities in tail-flick and hot-plate tests. In contrast, only weak antinociception was observed in the case of oral administration of morphine at a dose of 20 mg/kg. It was found that 7-hydroxymitragynine is a novel opioid agonist that is structurally different from the other opioid agonists, and has potent analgesic activity when orally administered.