Double-pulsed wave packets in spontaneous radiation from a tandem undulator

We verify that each wave packet of spontaneous radiation from two undulators placed in series has a double-pulsed temporal profile with pulse spacing which can be controlled at the attosecond level. Using a Mach–Zehnder interferometer operating at ultraviolet wavelengths, we obtain the autocorrelation trace for the spontaneous radiation from the tandem undulator. The results clearly show that the wave packet has a double-pulsed structure, consisting of a pair of 10-cycle oscillations with a variable separation. We also report the characterization of the time delay between the double-pulsed components in different wavelength regimes. The excellent agreement between the independent measurements confirms that a tandem undulator can be used to produce double-pulsed wave packets at arbitrary wavelength.

P2X2 receptors supply extracellular choline as a substrate for acetylcholine synthesis

Acetylcholine (ACh), an excitatory neurotransmitter, is biosynthesized from choline in cholinergic neurons. Import from the extracellular space to the intracellular environment through the high-affinity choline transporter is currently regarded to be the only source of choline for ACh synthesis. We recently demonstrated that the P2X₂ receptor, through which large cations permeate, functions as an alternative pathway for choline transport in the mouse retina. In the present study, we investigated whether choline entering cells through P2X₂ receptors is used for ACh synthesis using a recombinant system. When P2X₂ receptors expressed on HEK293 cell lines were stimulated with ATP, intracellular ACh concentrations increased. These results suggest that P2X₂ receptors function in a novel pathway that supplies choline for ACh synthesis.

Non-neuronal cardiac acetylcholine system playing indispensable roles in cardiac homeostasis confers resiliency to the heart

BACKGROUND

We previously established that the non-neuronal cardiac cholinergic system (NNCCS) is equipped with cardiomyocytes synthesizes acetylcholine (ACh), which is an indispensable endogenous system, sustaining cardiac homeostasis and regulating an inflammatory status, by transgenic mice overexpressing choline acetyltransferase (ChAT) gene in the heart. However, whole body biological significances of NNCCS remain to be fully elucidated.

METHODS AND RESULTS

To consolidate the features, we developed heart-specific ChAT knockdown (ChATKD) mice using 3 ChAT-specific siRNAs. The mice developed cardiac dysfunction. Factors causing it included the downregulation of cardiac glucose metabolism along with decreased signal transduction of Akt/HIF-1alpha/GLUT4, leading to poor glucose utilization, impairment of glycolytic metabolites entering the tricarboxylic (TCA) cycle, the upregulation of reactive oxygen species (ROS) production with an attenuated scavenging potency, and the downregulated nitric oxide (NO) production via NOS1. ChATKD mice revealed a decreased vagus nerve activity, accelerated aggression, more accentuated blood basal corticosterone levels with depression-like phenotypes, several features of which were accompanied by cardiac dysfunction.

CONCLUSION

The NNCCS plays a crucial role in cardiac homeostasis by regulating the glucose metabolism, ROS synthesis, NO levels, and the cardiac vagus nerve activity. Thus, the NNCCS is suggested a fundamentally crucial system of the heart.

S-Nitroso-N-Pivaloyl-D-Penicillamine, a novel non-neuronal ACh system activator, modulates cardiac diastolic function to increase cardiac performance under pathophysiological conditions

We have previously reported the development of a novel chemical compound, S-Nitroso-N-Pivaloyl-D-Penicillamine (SNPiP), for the upregulation of the non-neuronal cardiac cholinergic system (NNCCS), a cardiac acetylcholine (ACh) synthesis system, which is different from the vagus nerve releasing of ACh as a neurotransmitter. However, it remains unclear how SNPiP could influence cardiac function positively, and whether SNPiP could improve cardiac function under various pathological conditions. SNPiP-injected control mice demonstrated a gradual upregulation in diastolic function without changes in heart rate. In contrast to some parameters in cardiac function that were influenced by SNPiP 24 h or 48 h after a single intraperitoneal (IP) injection, 72 h later, end-systolic pressure, cardiac output, end-diastolic volume, stroke volume, and ejection fraction increased. IP SNPiP injection also improved impaired cardiac function, which is a characteristic feature of the db/db heart, in a delayed fashion, including diastolic and systolic function, following either several consecutive injections or a single injection. SNPiP, a novel NNCCS activator, could be applied as a therapeutic agent for the upregulation of NNCCS and as a unique tool for modulating cardiac function via improvement in diastolic function.

Potentiating a non-neuronal cardiac cholinergic system reinforces the functional integrity of the blood brain barrier associated with systemic anti-inflammatory responses

We previously reported that the heart-specific choline acetyltransferase (ChAT) gene overexpressing mice (ChAT tg) show specific phenotypes including ischemic tolerance and the CNS stress tolerance. In the current study, we focused on molecular mechanisms responsible for systemic and localized anti-inflammatory phenotypes of ChAT tg. ChAT tg were resistant to systemic inflammation induced by lipopolysaccharides due to an attenuated cytokine response. In addition, ChAT tg, originally equipped with less reactive Kupffer cells, were refractory to brain cold injury, with decreased blood brain barrier (BBB) permeability and reduced inflammation. This is because ChAT tg brain endothelial cells expressed more claudin-5, and their astrocytes were less reactive, causing decreased hypertrophy. Moreover, reconstruction of the BBB integrity in vitro confirmed the consolidation of ChAT tg. ChAT tg were also resistant to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) neuronal toxicity due to lower mortality rate and neuronal loss of substantia nigra. Additionally, ChAT tg subjected to MPTP showed attenuated BBB disruption, as evident from reduced sodium fluorescein levels in the brain parenchyma. The activated central cholinergic pathway of ChAT tg lead to anti-convulsive effects like vagus nerve stimulation. However, DSP-4, a noradrenergic neuron-selective neurotoxin against the CNS including the locus ceruleus, abrogated the beneficial phenotype and vagotomy attenuated expression of claudin-5, suggesting the link between the cholinergic pathway and BBB function. Altogether, these findings indicate that ChAT tg possess an anti-inflammatory response potential, associated with upregulated claudin-5, leading to the consolidation of BBB integrity. These characteristics protect ChAT tg against systemic and localized inflammatory pathological disorders, which targets the CNS.

A Novel Nitric Oxide Donor, S-Nitroso-NPivaloyl-D-Penicillamine, Activates a Non-Neuronal Cardiac Cholinergic System to Synthesize Acetylcholine and Augments Cardiac Function

BACKGROUND/AIMS

In a previous study, we reported that cardiomyocytes were equipped with non-neuronal cardiac cholinergic system (NNCCS) to synthesize acetylcholine (ACh), which is indispensable for maintaining the basic physiological cardiac functions. The aim of this study was to identify and characterize a pharmacological inducer of NNCCS.

METHODS

To identify a pharmacological inducer of NNCCS, we screened several chemical compounds with chemical structures similar to the structure of S-nitroso-N-acetyl-DL-penicillamine (SNAP). Preliminary investigation revealed that SNAP is an inducer of non-neuronal ACh synthesis. We screened potential pharmacological inducers in H9c2 and HEK293 cells using western blot analysis, luciferase assay, and measurements of intracellular cGMP, NO₂ and ACh levels. The effects of the screened compound on cardiac function of male C57BL6 mice were also evaluated using cardiac catheter system.

RESULTS

Among the tested compounds, we selected S-nitroso-Npivaloyl-D-penicillamine (SNPiP), which gradually elevated the intracellular cGMP levels and nitric oxide (NO) levels in H9c2 and HEK293 cells. These elevated levels resulted in the gradual transactivation and translation of the choline acetyltransferase gene. Additionally, in vitro and in vivo SNPiP treatment elevated ACh levels for 72 h. SNPiP-treated mice upregulated their cardiac function without tachycardia but with enhanced diastolic function resulting in improved cardiac output. The effect of SNPiP was dependent on SNPiP nitroso group as verified by the ineffectiveness of N-pivaloyl-D-penicillamine (PiP), which lacks the nitroso group.

CONCLUSION

SNPiP is identified to be one of the important pharmacological candidates for induction of NNCCS.

Novel channel-mediated choline transport in cholinergic neurons of the mouse retina

Choline uptake into the presynaptic terminal of cholinergic neurons is mediated by the high-affinity choline transporter and is essential for acetylcholine synthesis. In a previous study, we reported that P2X₂ purinoceptors are selectively expressed in OFF-cholinergic amacrine cells of the mouse retina. Under specific conditions, P2X₂ purinoceptors acquire permeability to large cations, such as N-methyl-d-glucamine, and therefore potentially could act as a noncanonical pathway for choline entry into neurons. We tested this hypothesis in OFF-cholinergic amacrine cells of the mouse retina. ATP-induced choline currents were observed in OFF-cholinergic amacrine cells, but not in ON-cholinergic amacrine cells, in mouse retinal slice preparations. High-affinity choline transporters are expressed at higher levels in ON-cholinergic amacrine cells than in OFF-cholinergic amacrine cells. In dissociated preparations of cholinergic amacrine cells, ATP-activated cation currents arose from permeation of extracellular choline. We also examined the pharmacological properties of choline currents. Pharmacologically, α,β-methylene ATP did not produce a cation current, whereas ATPγS and benzoyl-benzoyl-ATP (BzATP) activated choline currents. However, the amplitude of the choline current activated by BzATP was very small. The choline current activated by ATP was strongly inhibited by pyridoxalphosphate-6-azophenyl-2',4'-sulfonic acid. Accordingly, P2X₂ purinoceptors expressed in HEK-293T cells were permeable to choline and similarly functioned as a choline uptake pathway. Our physiological and pharmacological findings support the hypothesis that P2 purinoceptors, including P2X₂ purinoceptors, function as a novel choline transport pathway and may provide a new regulatory mechanism for cholinergic signaling transmission at synapses in OFF-cholinergic amacrine cells of the mouse retina.NEW & NOTEWORTHY Choline transport across the membrane is exerted by both the high-affinity and low-affinity choline transporters. We found that choline can permeate P2 purinergic receptors, including P2X₂ purinoceptors, in cholinergic neurons of the retina. Our findings show the presence of a novel choline transport pathway in cholinergic neurons. Our findings also indicate that the permeability of P2X₂ purinergic receptors to choline observed in the heterologous expression system may have a physiological relevance in vivo.

Remote ischemic preconditioning with a specialized protocol activates the non-neuronal cardiac cholinergic system and increases ATP content in the heart

Ischemic preconditioning (IPC) renders the targeted organ resistant to prolonged ischemic insults, leading to organoprotection. Among several means to achieve IPC, we reported that remote ischemic preconditioning (RIPC) activates the non-neuronal cardiac cholinergic system (NNCCS) to accelerate de novo ACh synthesis in cardiomyocytes. In the current study, we aimed to optimize a specific protocol to most efficiently activate NNCCS using RIPC. In this study, we elucidated that the protocol with 3 min of ischemia repeated three times increased cardiac ChAT expression (139.2 ± 0.4%; P < 0.05) as well as ACh (14.2 ± 2.0× 10(-8) M; P< 0.05) and ATP content (2.13 ± 0.19 μmol/g tissue; P < 0.05) in the heart. Moreover, in the specific protocol, several characteristic responses against energy starvation and for obtaining adequate energy were observed; therefore, it is suggested that RIPC evokes a robust response by the heart to activate NNCCS through the modification of energy metabolism.

miR-449a contributes to glucocorticoid-induced CRF-R1 downregulation in the pituitary during stress

The hypothalamic-pituitary-adrenal axis is controlled by the feedback of glucocorticoids on the hypothalamus and pituitary. Stress increases CRF, ACTH, and glucocorticoid secretion. The expression of not only CRF mRNA in the hypothalamus and proopiomelanocortin mRNA in corticotrophs, but also CRF type 1 receptor (CRF-R1) mRNA and protein on corticotrophs are downregulated through glucocorticoids. However, the mechanisms underlying the glucocorticoid-induced CRF-R1 downregulation are not fully understood. Short RNA molecules, called microRNAs (miRNAs), are posttranscriptional regulators that usually induce translational repression or gene silencing via binding to complementary sequences within target mRNAs. We hypothesized that glucocorticoids may induce the expression of miRNAs in the pituitary, which are involved in glucocorticoid-induced downregulation of CRF-R1. We found 3 miRNAs with sequences predicted to bind to the CRF-R1 3' untranslated region (3'-UTR) by database search. Expression of 1 of these miRNAs (miR-449a) was significantly higher in the anterior pituitary of restrained rats than in that of unrestrained control rats. Expression of miR-449a was evident in many anterior pituitary cells, including corticotrophs. Although overexpression of miR-449a decreased CRF-R1 mRNA and CRF-R1 protein expression, knockdown of miR-449a attenuated dexamethasone-induced suppression of CRF-R1 mRNA and CRF-R1 protein expression in the monolayer-cultured pituitary cells. Notably, luciferase activity was significantly lower in cells cotransfected with a luciferase vector containing the CRF-R1 3'-UTR and a miR-449a vector. miR-449a expression was significantly increased by dexamethasone. Adrenalectomy attenuated restraint-induced increase in miR-449a expression in the pituitary. These results indicated that miR-449a plays an important role in stress-induced, glucocorticoid-mediated downregulation of CRF-R1 expression.

Increased expression of miR-325-3p by urocortin 2 and its involvement in stress-induced suppression of LH secretion in rat pituitary

Urocortin 2 (Ucn2) is a member of the corticotropin releasing factor (CRF) peptide family, which binds to CRF type 2 receptor. We previously reported on expression of Ucn2 in proopiomelanocortin cells of rat pituitary and its inhibitory action on LH secretion. We also demonstrated that Ucn2 is involved in the mechanism underlying immobilization-induced suppression of LH secretion; the details remain unclear. Here, we found that Ucn2 increased the expression of miR-325-3p, one of three microRNAs with predicted sequence for binding to LH β-subunit 3'-untranslated region (3'-UTR) in monolayer cultured rat anterior pituitary cells, and that miR-325-3p was expressed in LH cells of the anterior pituitary. Immobilization also increased miR-325-3p expression in the anterior pituitary, and its increase was blocked by pretreatment with anti-Ucn2 IgG. Overexpression of miR-325-3p in cultured pituitary cells significantly suppressed intracellular contents and secretion of LH, while miR-325-3p knockdown blocked Ucn2-induced suppression of intracellular contents and secretion of LH. Coexpression of miR-325-3p with LH β-subunit 3'-UTR-fused luciferase vector significantly suppressed luciferase activity compared with that of mock transfectants. These results suggest that miR-325-3p is involved in immobilization-induced suppression of LH translation and secretion and that Ucn2 plays a role in the increase in miR-325-3p expression.

The effects of ghrelin/GHSs on AVP mRNA expression and release in cultured hypothalamic cells in rats

Ghrelin, the endogenous ligand for growth hormone secretagogues (GHSs) receptor (GHS-R), increases adrenocorticotropin (ACTH) and cortisol (corticosterone) as well as GH secretion in humans and animals. However, the site of GHSs action to induce ACTH secretion is not fully understood. To clarify the mechanisms of the action of ghrelin/GHSs on ACTH secretion, we analyzed the effects of KP-102 and ghrelin on the mRNA expression and release of corticotropin releasing factor (CRF) and arginine vasopressin (AVP), ACTH secretagogues, in monolayer-cultured hypothalamic cells of rats. Incubation of cells with KP-102 for 4h and 8h and with ghrelin for 4h significantly increased AVP mRNA expression and release without changing CRF mRNA expression. CRF levels in culture media were undetectable. Suppression of GHS-R expression by siRNA blocked ghrelin- and KP-102-induced AVP mRNA expression and release. NPY significantly increased AVP mRNA expression and release. Furthermore, treatment of cells with anti-NPY IgG blocked KP-102-induced AVP mRNA expression and release. We previously reported that KP-102 significantly increases NPY mRNA expression in cultured hypothalamic cells. Taken together, these results suggest that ACTH secretion by ghrelin/GHSs is induced mainly through hypothalamic AVP, and that NPY mediates the action of ghrelin/GHSs.

Reversible myocardial hypertrophy induced by tacrolimus in a pediatric heart transplant recipient: case report

Tacrolimus is a potent immunosuppressant that is frequently used in organ transplantation. However, adverse effects include cardiac toxicity. Herein we describe transient myocardial hypertrophy induced by tacrolimus after heart transplantation. The hypertrophy caused no clinical symptoms but was noted because of elevation of plasma brain natriuretic peptide concentration and confirmed at echocardiography. Initially, allograft rejection was feared; however, myocardial biopsy samples revealed only interstitial edema and mild myocardial hypertrophy; neither cellular nor humoral rejection was detected. The blood tacrolimus concentration was higher than usual at that time; thus, tacrolimus dosage was reduced. Myocardial hypertrophy completely resolved upon reducing the target concentration of tacrolimus and did not recur, as confirmed at echocardiography and myocardial biopsy. Thus, we conclude that tacrolimus induces reversible myocardial hypertrophy. In patients receiving tacrolimus therapy, blood concentration should be carefully controlled and extreme attention paid to cardiac involvement.

CA-125 AUC as a new prognostic factor for patients with ovarian cancer

OBJECTIVE

The aim of the present study was to investigate the usefulness of the CA-125 area under the curve (AUC) as a new kinetic parameter for predicting overall survival in patients with ovarian cancer. In addition, the relationship of CA-125 AUC with other prognostic factors of ovarian cancer was evaluated.

METHODS

Ninety-two patients that underwent primary line chemotherapy within 4 months after submission to cytoreductive surgery were included. For each patient, CA-125 AUC was calculated and a statistical analysis was conducted to compare CA-125 AUC behavior among patients according to several covariates.

RESULTS

The mean age at diagnostic time was found to be 55.5 (16.1-82.4) years with a mean survival of 39.2 (3.5-100.1; SE = 2.6) months. Across FIGO stage I, II, III, and IV patients had a mean CA-125 AUC of 18.2, 24.6, 147.8, and 574.6 IU/ml*days, respectively (P < 0.05). At the evaluation date, living patients had a mean CA-125 AUC of 40.1 in contrast to 234.1 IU/ml*days (P < 0.05) for deceased ones. Patients with a complete response to primary chemotherapy had a mean CA-125 AUC of 48.8, while patients with a partial response had a mean of 251.7 IU/ml*days, and patients with no response or disease progression had a mean of 316.5 IU/ml*days (P < 0.05). The best CA-125 AUC performance is in predicting patient complete response to chemotherapy with a cut-off of 100 IU/ml*days and an accuracy of 82%.

CONCLUSIONS

Despite CA-125 AUC high correlation with the FIGO stage, residual disease, and patient final outcome, the main interest of CA-125 AUC calculation is to evaluate the treatment efficacy and to foresee a full chemotherapy response. Further studies should be carried out before extrapolating these results to other data sets.

Nitrite removal in a submerged biofilter

Nowadays submerged filters seem to be the preferred technology for denitrification purposes. Optimisation of biological nitrogen has recently been tried based the nitrate shunt in order to save two of the involved steps. Former studies have shown that a build-up of nitrite can be achieved by an appropriate control of the nitrification process either in suspended cultures or in fixed cultures. An experimental plan was conducted to study the effect of different types of carbon source (acetate, ethanol and urban wastewater) on the performance of a submerged down flow biofilter, as well as the influence of the hydraulic loading. Results have shown that maximum nitrogen removal rates were similar for acetate and ethanol attaining values significantly higher than for urban waste water. On the other hand, nitrogen massic loading appeared to be the limiting factor for efficiency rather than hydraulic loading.

Important role of energy-dependent mitochondrial pathways in cultured rat cardiac myocyte apoptosis

Recent studies have suggested that apoptosis and necrosis share common features in their signaling pathway and that apoptosis requires intracellular ATP for its mitochondrial/apoptotic protease-activating factor-1 suicide cascade. The present study was, therefore, designed to examine the role of intracellular energy levels in determining the form of cell death in cardiac myocytes. Neonatal rat cardiac myocytes were first incubated for 1 h in glucose-free medium containing oligomycin to achieve metabolic inhibition. The cells were then incubated for another 4 h in similar medium containing staurosporine and graded concentrations of glucose to manipulate intracellular ATP levels. Under ATP-depleting conditions, the cell death caused by staurosporine was primarily necrotic, as determined by creatine kinase release and nuclear staining with ethidium homodimer-1. However, under ATP-replenishing conditions, staurosporine increased the percentage of apoptotic cells, as determined by nuclear morphology and DNA fragmentation. Caspase-3 activation by staurosporine was also ATP dependent. However, loss of mitochondrial transmembrane potential (DeltaPsi(m)), Bax translocation, and cytochrome c release were observed in both apoptotic and necrotic cells. Moreover, cyclosporin A, an inhibitor of mitochondrial permeability transition, attenuated staurosporine-induced apoptosis and necrosis through the inhibition of DeltaPsi(m) reduction, cytochrome c release, and caspase-3 activation. Our data therefore suggest that staurosporine induces cell demise through a mitochondrial death signaling pathway and that the presence of intracellular ATP favors a shift from necrosis to apoptosis through caspase activation.

A de novo philadelphia chromosome-positive acute mixed-lineage leukemia with both major and minor BCR/ABL mRNA transcripts

A patient with a Philadelphia chromosome (Ph)-positive acute mixed-lineage leukemia (AMLL) expressing both major and minor BCR/ABL mRNA transcripts is described. Phenotypic analysis of the leukemic blasts revealed positivity for both myeloid and B-cell lineages. Southern blot analysis showed a rearrangement of the immunoglobulin heavy chain (IgH) gene. Reverse transcriptase polymerase chain reaction (RT-PCR) analysis showed the expression of both major and minor BCR/ABL mRNA transcripts. To our knowledge, this is the first report of AMLL expressing both major and minor BCR/ABL mRNA transcripts and rearrangement of the IgH gene.

[Central muscle relaxant activities of 2-methyl-3-aminopropiophenone derivatives]

In this experiment, we synthetized new 2-methyl-3-aminopropiophenone (MP) derivatives, whose structure is known to have central muscle relaxant activities, and quinolizidine and indan . tetralin derivatives derived from MP by cyclization, and we investigated the central muscle relaxant activity. Among the quinolizidine derivatives, there was a very strong central depressant agent, trans (3H, 9aH)-3-(p-chloro) benzoyl-quinolizidine (HSR-740), and among the indan . tetralin derivatives, there was an excitant agents, trans (1H, 2H)-5-methoxy-3, 3-dimethyl-2-piperidinomethyl indan-1-ol (HSR-719). From the results, these derivatives were not considered to be adequate for central muscle relaxant. Among the MP derivatives, (4'-chloro-2'-methoxy-3-piperidino) propiophenone HCl (HSR-733) and (4'-ethyl-2-methyl-3-pyrrolidino) propiophenone HCl (HSR-770) strongly inhibited the cooperative movement in the rotating rod method using mice, and it exerted almost the same depressant activity on the cross extensor reflex using alpha-chloralose anesthetized rats. However, the inhibitory effects of HSR-733 on the anemic decerebrate rigidity and the rigidity induced by intracollicular decerebration in rats were weaker than those of HSR-770 and eperisone. In spinal cats, at a low dose (5 mg/kg, i.v.), HSR-733 depressed monosynaptic and dorsal root reflex potentials as compared with polysynaptic reflex potentials, and inhibitory effects of HSR-733 on these three reflex potentials were more potent than those of eperisone and HSR-770. Although HSR-770 acts on the spinal cord and supraspinal level on which eperisone has been reported to act, HSR-733 may mainly act on the spinal cord. These results indicate that the MP derivative with a 2-methyl group may be suitable as a central muscle relaxant. HSR-770, which has equipotent muscle relaxant activity to eperisone, exerted strong inhibitory effects on oxotremorine-induced tremor and weak inhibitory effects on spontaneous motor activity in the Animex method using mice, as compared with eperisone.