Rostral ventrolateral medulla: selective projections to the thoracic autonomic cell column from the region containing C1 adrenaline neurons

Anterograde, retrograde, and combined axonal transport methods were used to describe the descending efferent projections of a region of rostral ventrolateral medullary reticular formation important in cardiovascular control. We have termed this region, which contains C1 adrenaline-synthesizing neurons, the nucleus reticularis rostroventrolateralis (RVL). Efferent projections from the RVL innervate all segmental levels of the thoracic intermediolateral and intermediomedial columns as shown using retrograde transport of lectin-conjugated horseradish peroxidase (HRP) or fast blue dye, and anterograde transport of either HRP or labeled amino acids. The projection is highly specific in that there are no projections to thoracic dorsal or ventral horns. This innervation corresponds to the distribution of preganglionic sympathetic neurons in the intermediolateral column. In particular, terminals surround neurons projecting to the adrenal medulla, as demonstrated by combined anterograde and retrograde transport methods at the light level. Terminals containing phenylethanolamine-N-methyl transferase (PNMT) were mapped using immunocytochemical techniques. PNMT-labeled terminals were present at all levels of thoracic intermediolateral column, in a distribution similar to that of the descending projections from the RVL. We have previously shown using double label techniques (Ross et al., '81-'83), that many of the spinal projections of the RVL originate from C1 neurons. These data support our suggestion that certain bulbospinal neurons within the RVL, in particular the C1 neurons, are crucial for tonic vasomotor control.

Control of circadian rhythms and photoperiodic flowering by the Arabidopsis GIGANTEA gene

Photoperiodic responses in plants include flowering that is day-length-dependent. Mutations in the Arabidopsis thaliana GIGANTEA (GI) gene cause photoperiod-insensitive flowering and alteration of circadian rhythms. The GI gene encodes a protein containing six putative transmembrane domains. Circadian expression patterns of the GI gene and the clock-associated genes, LHY and CCA1, are altered in gi mutants, showing that GI is required for maintaining circadian amplitude and appropriate period length of these genes. The gi-1 mutation also affects light signaling to the clock, which suggests that GI participates in a feedback loop of the plant circadian system.

Chemical and structural analysis of the relation between cortical inputs and tyrosine hydroxylase-containing terminals in rat neostriatum

Levels of tyrosine hydroxylase (TH) and the ultrastructural relation between axons from cerebral cortex and TH containing, predominantly dopaminergic terminals were examined in the adult rat neostriatum at 2 and 12 days following unilateral decortication. The caudate nuclei from the unlesioned and lesioned hemispheres were biochemically assayed for TH processed for light or electron microscopic localization of the enzyme. At both time intervals examined, there was no statistically significant alteration in TH activity or apparent change in the intensity of reactive labeling visualized by light microscopy. However, electron microscopic examination of the caudate nucleus homolateral to the decortication at two days following surgery revealed the presence of numerous small, osmiophilic boutons which were much less frequently seen on the contralateral side. Further ultrastructural examination showed that the osmiophilic boutons formed predominantly asymmetric, axodendritic synapses. In sections containing both degenerating and TH labeled terminals, two patterns of connectivity could be discovered. First and most commonly, the degenerating and TH-labeled terminals formed synapses with the same dendrite or dendritic spine. Less frequently, the two types of terminals were in direct contact with each other. In this axo-axonic relation, the outer membranes between the terminals were in apposition but usually failed to exhibit pre- or postsynaptic specializations. These findings indicate that the cortical and dopaminergic nigral efferents have actions on common recipient neurons in the rat caudate nucleus and provide support for a possible direct axonal interrelationship between these two primary inputs.

Electricity generation in microbial fuel cells using neutral red as an electronophore

Neutral red (NR) was utilized as an electron mediator in microbial fuel cells consuming glucose to study both its efficiency during electricity generation and its role in altering anaerobic growth and metabolism of Escherichia coli and Actinobacillus succinogenes. A study of chemical fuel cells in which NADH, NR, and ferricyanide were the electron donor, the electronophore, and the electron acceptor, respectively, showed that electrical current produced from NADH was proportional to the concentration of NADH. Fourfold more current was produced from NADH in chemical fuel cells when NR was the electron mediator than when thionin was the electron mediator. In microbial fuel cells in which E. coli resting cells were used the amount of current produced from glucose when NR was the electron mediator (3.5 mA) was 10-fold more than the amount produced when thionin was the electron mediator (0.4 mA). The amount of electrical energy generated (expressed in joules per mole of substrate) and the amount of current produced from glucose (expressed in milliamperes) in NR-mediated microbial fuel cells containing either E. coli or A. succinogenes were about 10- and 2-fold greater, respectively, when resting cells were used than when growing cells were used. Cell growth was inhibited substantially when these microbial fuel cells were making current, and more oxidized end products were formed under these conditions. When sewage sludge (i.e., a mixed culture of anaerobic bacteria) was used in the fuel cell, stable (for 120 h) and equivalent levels of current were obtained with glucose, as observed in the pure-culture experiments. These results suggest that NR is better than other electron mediators used in microbial fuel cells and that sludge production can be decreased while electricity is produced in fuel cells. Our results are discussed in relation to factors that may improve the relatively low electrical efficiencies (1.2 kJ/mol) obtained with microbial fuel cells.

Endoscopic ultrasound-guided versus conventional transmural drainage for pancreatic pseudocysts: a prospective randomized trial

BACKGROUND AND STUDY AIMS

Although endoscopic ultrasound (EUS)-guided transmural drainage (EUD) is preferred over conventional transmural drainage (CTD) of pancreatic pseudocysts by endoscopy in many centers, its superiority with respect to technical success and clinical outcome has not yet been demonstrated in a prospective randomized trial. We conducted this prospective randomized trial to compare the technical success and clinical outcomes of EUD and CTD in treating pancreatic pseudocysts.

PATIENTS AND METHODS

A total of 60 consecutive patients with pancreatic pseudocysts were randomly divided into two groups to undergo either EUD (n = 31) or CTD (n = 29) of pancreatic pseudocysts. The technical success rate, complications, and short-term and long-term results were prospectively evaluated.

RESULTS

The rate of technical success of the drainage was higher for EUD (94 %, 29/31) than for CTD (72 %, 21/29; P = 0.039) in intention-to-treat analysis. In cases where CTD failed (n = 8), because the pseudocysts were nonbulging, a crossover was made to EUD, which was successfully performed in all these patients. Complications occurred in 7 % of the EUD and 10 % of the CTD group ( P = 0.67). During short-term follow-up, pseudocyst resolution was achieved in 97 % (28/29) in the EUD group and in 91 % (19/21) in the CTD group ( P = 0.565). Long-term results analyzed on a per-protocol basis showed no significant difference in clinical outcomes between EUD (89 %, 33/37) and CTD (86 %, 18/21, P = 0.696).

CONCLUSIONS

We found that EUD and CTD can both be considered first-line methods of endoscopic transmural drainage of bulging pseudocysts, whereas EUD should be preferred for nonbulging pseudocysts.

Distribution of neurons containing phenylethanolamine N-methyltransferase in medulla and hypothalamus of rat

Neurons immunocytochemically labeled with the adrenaline-synthesizing enzyme phenylethanolamine N-methyltransferase were mapped in the brain of rat pretreated with colchicine. In medulla, immunoreactive cells in the C1 and C2 groups were distributed in a more complex manner than described previously. C1 neurons were identified in the reticular formation of ventrolateral medulla and were organized into two populations: (1) a cell column extending throughout the ventrolateral medulla, and lying ventral to the ambiguus cell group and either dorsal to the precerebellar lateral reticular nucleus or interposed between its two subdivisions; (2) a rostral cell cluster forming medial to the column at caudal levels and enlarging close to and in parallel with the ventral surface of the rostral ventrolateral medulla. A large proportion of cells and processes of the rostral cell group were oriented medially and ventromedially. processes of C1 neurons were traced dorsally toward the nucleus tractus solitarii, dorsal motor nucleus, and principal tegmental adrenergic bundle, ventrally toward the ventral surface, laterally toward the trigeminal complex, and medially or ventromedially toward the raphe. C2 neurons were located in the dorsomedial medulla and were subdivided into four distinct populations: (1) neurons in the rostral nucleus paragigantocellularis pars dorsalis (NGCd) and medial longitudinal fasciculus (MLF) were contiguous and similar in size and shape, with their long diameters oriented horizontally or diagonally along several axes; (2) neurons of the periventricular gray were located in a cytoarchitecturally undefined area dorsal to the MLF; these cells were ovoid, smaller, and organized more compactly than those in the NGCd-MLF; (3) a cell group in the rostromedial nucleus tractus solitarii (NTS) and dorsal motor nucleus overflowed caudally into the intermediate thirds of both structures; and (4) a parvicellular group in the NTS was compactly organized in the dorsolateral NTS and was best developed at the level of the area postrema. Processes of C2 neurons were generally directed sagitally, medially, and laterally along the ventricular floor and ventrally or medially toward the raphe; other fibers arborized and terminated within the NTS and dorsal motor nucleus. In the medulla, local processes were traced from C1 and C2 neurons directly into respective ventral and dorsal parts of the medullary raphe and surrounding intraparenchymal blood vessels. Fibers from these neurons were also followed, respectively, onto the ventral subpial surface and the floor of the fourth ventricle.(ABSTRACT TRUNCATED AT 400 WORDS)

Direct phosphorylation of brain tyrosine hydroxylase by cyclic AMP-dependent protein kinase: mechanism of enzyme activation

Tyrosine hydroxylase [tyrosine monooxygenase, L-tyrosine, tetrahydropteridine:oxygen oxidoreductase (3-hydroxylating), EC 1.14.16.2] was highly purified from rat caudate nuclei. When the pure hydroxylase was phosphorylated by incubation with cyclic AMP-dependent protein kinase and [32P]ATP, 32P and tyrosine hydroxylase activity were detected after polyacrylamide gel electrophoresis in a single protein band. After sodium dodecyl sulfate gel electrophoresis, 32P was detected only in a probably active subunit of tyrosine hydroxylase of molecular weight 62,000. Phosphorylation of the hydroxylase increased its activity by 2-fold, and was associated with an increase in Vm without any change in Km for either substrate or cofactor. We propose that the pool of native tyrosine hydroxylase is composed of a mixture of enzyme molecules in both active and probably inactive forms, that the active form is phosphorylated, and that phosphorylation produces an active form of the enzyme at the expense of an inactive one.

Adrenaline synthesizing neurons in the rostral ventrolateral medulla: a possible role in tonic vasomotor control

Adrenaline-containing neurons of the rostral ventrolateral medulla (the C1 group) project selectively to autonomic spinal neurons in rats. Stimulation of these neurons electrically or chemically elevates arterial pressure, while neuronal blockade by microinjection of tetrodotoxin bilaterally drops arterial pressure to levels comparable to those produced by spinal cord transection. Adrenaline neurons of the ventral medulla appear necessary for maintaining normal levels of blood pressure, and thus may constitute a tonic vasomotor center.

Recent advances in autoimmune pancreatitis

Autoimmune pancreatitis (AIP) is distinct from calcifying and obstructive forms of chronic pancreatitis. Clinically and histologically it has two distinct subsets: (i) lymphoplasmacytic sclerosing pancreatitis or type 1 AIP which appears to be a systemic disease characterised by abundant infiltration of affected organs with immunoglobulin G4 (IgG4)-positive plasma cells and (2) duct-centric or type 2 AIP characterised by granulocyte epithelial lesions in the pancreas without systemic involvement. In AIP a marked lymphoplasmacytic infiltrate that responds dramatically to steroid therapy suggests an autoimmune aetiology. However, the target autoantigen(s) and the effector cells in AIP remain speculative. Despite the consistent elevation in serum IgG4 levels and tissue infiltration with IgG4-positive plasma cells in type 1 AIP, the role of IgG4 in its pathogenesis remains unknown. Recent development of animal models of AIP will help improve our understanding of the pathogenesis of these newly described forms of chronic pancreatitis.

Aromatic L-amino acid decarboxylase in the rat brain: immunocytochemical localization in neurons of the brain stem

Neurons containing the enzyme aromatic L-amino acid decarboxylase were immunocytochemically localized in the brain stem of the rat. The enzyme occurred as expected in previously well characterized monoaminergic cell groups, and in addition in some nuclei with unknown neurotransmitters. Major aggregates of neurons that were immunoreactive for aromatic L-amino acid decarboxylase but contained neither tyrosine hydroxylase nor serotonin, were found in the pretectal nuclei, the lateral parabrachial nucleus, and the dorsolateral subdivision of the nucleus tractus solitarius. Aromatic L-amino acid decarboxylase was also present in serotonin neurons and the majority of catecholamine cell groups. Dopamine, noradrenaline, and adrenaline cells exhibited characteristic staining intensities to anti-aromatic L-amino acid decarboxylase reflective of relative enzyme levels in the different groups. Some cells in the dorsal motor nucleus of the vagus that were previously classified as dopaminergic lacked immunoreactivity to aromatic L-amino acid decarboxylase.

Some neurons of the rat central nervous system contain aromatic-L-amino-acid decarboxylase but not monoamines

Neurons containing the enzyme aromatic-L-amino-acid decarboxylase (AADC) but lacking either tyrosine hydroxylase or serotonin were found in the spinal cord of neonatal and adult rats by light and electron microscopic immunocytochemistry. The majority of these neurons localized to area X of Rexed contact ependyma. Thus, spinal AADC neurons have the enzymatic capacity to catalyze directly the conversion of the amino acids tyrosine, tryptophan, or phenylalanine to their respective amines tyramine, tryptamine, or phenylethylamine. These amines normally present in the central nervous system may be of potential clinical significance as endogenous psychotomimetics.

Is a 2-week steroid trial after initial negative investigation for malignancy useful in differentiating autoimmune pancreatitis from pancreatic cancer? A prospective outcome study

BACKGROUND

Autoimmune pancreatitis (AIP) is a peculiar type of chronic pancreatitis that responds dramatically to steroid therapy. To date, there are no worldwide consensus criteria for AIP. Different criteria with institutional preference (HISORt, revised Kim and the revised Japanese criteria) are being used to diagnose AIP, and there is controversy regarding the inclusion of steroid responsiveness in the diagnostic criteria. In contrast to the HISORt and revised Kim criteria, the revised Japanese criteria do not include steroid responsiveness as a diagnostic component.

AIMS

This study was performed to evaluate whether "a 2-week steroid trial and subsequent assessment of its response" is a useful diagnostic tool for the differentiation of AIP from pancreatic cancer. A further aim was to discover the surgical and clinical outcome for a patient who followed the treatment algorithm based on the steroid responsiveness.

PATIENTS AND METHODS

From January 2004 to June 2007, in the setting of clinically suspected AIP, 22 consecutive patients with atypical imaging for AIP, while not meeting the classic imaging criteria for pancreatic cancer, were challenged to undergo 2 weeks of steroid therapy (0.5 mg/kg of oral prednisolone per day). After the 2-week steroid trial, steroid responsiveness was assessed based on a marked improvement of narrowing of the main pancreatic duct and a reduction of the pancreatic mass. The steroid trial was continued in the case of positive steroid responsiveness, whereas surgical exploration was conducted in the case of negative steroid responsiveness. The final diagnosis was made by surgical exploration or long-term clinical and radiological follow-up.

RESULTS

All patients (n = 15) who responded to steroids were diagnosed as having AIP, whereas all patients (n = 7) who did not show a response to steroids were confirmed as having pancreatic cancer. Complete resection was possible in all (6/6; 100%), except one individual who refused surgery.

CONCLUSION

In the clinical setting of suspected AIP with the continued need for differentiation from pancreatic cancer due to atypical imaging for AIP, "a 2-week steroid trial and subsequent assessment of its response" may be helpful in confirming the diagnosis of AIP without negative consequences for resectable pancreatic cancer. However, a steroid trial should be performed carefully only by specialists in pancreatology.

Microbial utilization of electrically reduced neutral red as the sole electron donor for growth and metabolite production

Electrically reduced neutral red (NR) served as the sole source of reducing power for growth and metabolism of pure and mixed cultures of H2-consuming bacteria in a novel electrochemical bioreactor system. NR was continuously reduced by the cathodic potential (-1.5 V) generated from an electric current (0.3 to 1.0 mA), and it was subsequently oxidized by Actinobacillus succinogenes or by mixed methanogenic cultures. The A. succinogenes mutant strain FZ-6 did not grow on fumarate alone unless electrically reduced NR or hydrogen was present as the electron donor for succinate production. The mutant strain, unlike the wild type, lacked pyruvate formate lyase and formate dehydrogenase. Electrically reduced NR also replaced hydrogen as the sole electron donor source for growth and production of methane from CO2. These results show that both pure and mixed cultures can function as electrochemical devices when electrically generated reducing power can be used to drive metabolism. The potential utility of utilizing electrical reducing power in enhancing industrial fermentations or biotransformation processes is discussed.

Role of exercise in age-related sarcopenia

Sarcopenia is an age-associated decline of skeletal muscle mass and function and is known to lead to frailty, cachexia, osteoporosis, metabolic syndromes, and death. Notwithstanding the increasing incidence of sarcopenia, the molecular and cellular mechanisms driving age-related sarcopenia are not completely understood. This article reviews current definitions of sarcopenia, its potential mechanisms, and effects of exercise on sarcopenia. The pathogenesis of age-related sarcopenia is multifactorial and includes myostatin, inflammatory cytokines, and mitochondria-derived problems. Especially, age-induced mitochondrial dysfunction triggers the production of reactive oxygen species (ROS) by mitochondria, impedes mitochondrial dynamics, interrupts mitophagy, and leads to mitochondria-mediated apoptosis. Aerobic exercise provides at least a partial solution to sarcopenia as it ameliorates mitochondria-derived problems, and resistance exercise strengthens muscle mass and function. Furthermore, combinations of these exercise types provide the benefits of both. Collectively, this review summarizes potential mechanisms of age-related sarcopenia and emphasizes the use of exercise as a therapeutic strategy, suggesting that combined exercise provides the most beneficial means of combating age-related sarcopenia.

A randomised phase II study of modified FOLFIRI.3 vs modified FOLFOX as second-line therapy in patients with gemcitabine-refractory advanced pancreatic cancer

Background:

Only a few clinical trials have been conducted in patients with advanced pancreatic cancer after failure of first-line gemcitabine-based chemotherapy. Therefore, there is no current consensus on the treatment of these patients. We conducted a randomised phase II study of the modified FOLFIRI.3 (mFOLFIRI.3; a regimen combining 5-fluorouracil (5-FU), folinic acid, and irinotecan) and modified FOLFOX (mFOLFOX; a regimen combining folinic acid, 5-FU, and oxaliplatin) regimens as second-line treatments in patients with gemcitabine-refractory pancreatic cancer.

Methods:

The primary end point was the 6-month overall survival rate. The mFOlFIRI.3 regimen consisted of irinotecan (70 mg m⁻²; days 1 and 3), leucovorin (400 mg m⁻²; day 1), and 5-FU (2000 mg m⁻²; days 1 and 2) every 2 weeks. The mFOLFOX regimen was composed of oxaliplatin (85 mg m⁻²; day 1), leucovorin (400 mg m⁻²; day 1), and 5-FU (2000 mg m⁻²; days 1 and 2) every 2 weeks.

Results:

Sixty-one patients were randomised to mFOLFIRI.3 (n=31) or mFOLFOX (n=30) regimen. The six-month survival rates were 27% (95% confidence interval (CI)=13–46%) and 30% (95% CI=15–49%), respectively. The median overall survival periods were 16.6 and 14.9 weeks, respectively. Disease control was achieved in 23% (95% CI=10–42%) and 17% patients (95% CI=6–35%), respectively. The number of patients with at least one grade 3/4 toxicity was identical (11 patients, 38%) in both groups: neutropenia (7 patients under mFOLFIRI.3 regimen vs 6 patients under mFOLFOX regimen), asthaenia (1 vs 4), vomiting (3 in both), diarrhoea (2 vs 0), and mucositis (1 vs 2).

Conclusion:

Both mFOLFIRI.3 and mFOLFOX regimens were tolerated with manageable toxicity, offering modest activities as second-line treatments for patients with advanced pancreatic cancer, previously treated with gemcitabine.

Utilization of electrically reduced neutral red by Actinobacillus succinogenes: physiological function of neutral red in membrane-driven fumarate reduction and energy conservation

Neutral red (NR) functioned as an electronophore or electron channel enabling either cells or membranes purified from Actinobacillus succinogenes to drive electron transfer and proton translocation by coupling fumarate reduction to succinate production. Electrically reduced NR, unlike methyl or benzyl viologen, bound to cell membranes, was not toxic, and chemically reduced NAD. The cell membrane of A. succinogenes contained high levels of benzyl viologen-linked hydrogenase (12.2 U), fumarate reductase (13.1 U), and diaphorase (109.7 U) activities. Fumarate reductase (24.5 U) displayed the highest activity with NR as the electron carrier, whereas hydrogenase (1.1 U) and diaphorase (0.8 U) did not. Proton translocation by whole cells was dependent on either electrically reduced NR or H2 as the electron donor and on the fumarate concentration. During the growth of Actinobacillus on glucose plus electrically reduced NR in an electrochemical bioreactor system versus on glucose alone, electrically reduced NR enhanced glucose consumption, growth, and succinate production by about 20% while it decreased acetate production by about 50%. The rate of fumarate reduction to succinate by purified membranes was twofold higher with electrically reduced NR than with hydrogen as the electron donor. The addition of 2-(n-heptyl)-4-hydroxyquinoline N-oxide to whole cells or purified membranes inhibited succinate production from H2 plus fumarate but not from electrically reduced NR plus fumarate. Thus, NR appears to replace the function of menaquinone in the fumarate reductase complex, and it enables A. succinogenes to utilize electricity as a significant source of metabolic reducing power.

Unmasking of hydrogen tunneling in the horse liver alcohol dehydrogenase reaction by site-directed mutagenesis

Primary and secondary kD/kT and kH/kT kinetic isotope effects have been studied as a probe of hydrogen tunneling in the oxidation of benzyl alcohol catalyzed by horse liver alcohol dehydrogenase (LADH). In the case of the wild-type enzyme, isotope effects at 25 degrees C do not clearly support hydrogen tunneling; this result is consistent with a reaction rate that is partially limited by the release of product benzaldehyde. The three-dimensional structure for LADH was used to design site-directed mutations in an effort to enhance the rate of the product release step and to "unmask" tunneling. Substitutions that increased the size of the alcohol binding pocket resulted in minor changes in isotope effects. By contrast, reduction in the size of the alcohol binding pocket through substitution at residues 57 and 93, which are in van der Waals contact with bound alcohol substrate, produced a clear demonstration of protium tunneling from the breakdown of the semiclassical relationship between kD/kT and kH/kT isotope effects. The temperature dependence of kD/kT isotope effects has also been pursued, leading to the conclusion that tunneling does, in fact, occur in the reaction catalyzed by wild-type LADH. Despite the unmasking of protium tunneling in site-directed mutants, substitutions that decrease the size of the alcohol pocket appear to result in less extensive tunneling in the hydride transfer. It is noteworthy that the mutant enzyme (Leu57-->Phe), which shows the greatest evidence of tunneling, has the same catalytic efficiency (Vmax/Km) as the wild-type enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Endoscopic ultrasound-guided rendezvous for biliary access after failed cannulation

INTRODUCTION

Selective cannulation fails in approximately 3 % of endoscopic retrograde cholangiography (ERC) procedures. An endoscopic ultrasound-guided rendezvous technique (EUS - RV) may salvage failed cannulation. The aims of the current study were to determine the safety and efficacy of EUS - RV.

METHODS

A total of 40 patients underwent salvage EUS - RV. EUS - RV was attempted immediately after failed biliary cannulation. A dilated intra- or extra-hepatic biliary duct (IHBD or EHBD) was punctured from the stomach or the small intestine under EUS guidance followed by cholangiography and antegrade manipulation of the guide wire into the small intestine. Finally, the echoendoscope was exchanged for an appropriate endoscope and biliary cannulation was achieved over or adjacent to the guide wire.

RESULT

EUS-RV appears safe and effective and may be considered as a primary salvage technique after failed cannulation. Antegrade manipulation of the guide wire into the small intestine was achieved in 29 of 40 patients (73 %; EHBD 25 /31 and IHBD 4/9). The reasons for failure were inability to advance the guide wire through an obstruction or a native ampulla. Re-attempt at ERC immediately after failed EUS - RV was made in seven of the 11 patients, and was successful in four. The remaining seven patients underwent percutaneous drainage within 3 days. Complications occurred in five patients (13 %), including pancreatitis, abdominal pain, pneumoperitoneum, and sepsis/death, which was unlikely to be related to the procedure.

CONCLUSION

EUS - RV is safe and effective and should be considered as a primary salvage technique after failed cannulation. Immediate re-attempt at ERC after failed EUS - RV is warranted, as EUS-guided cholangiogram can facilitate biliary cannulation in some cases. Finally, prompt alternative biliary drainage should be available.

Roles of myokines in exercise-induced improvement of neuropsychiatric function

Exercise is a well-known non-pharmacological intervention to improve brain functions, including cognition, memory, and motor coordination. Contraction of skeletal muscles during exercise releases humoral factors that regulate the whole-body metabolism via interaction with other non-muscle organs. Myokines are muscle-derived effectors that regulate body metabolism by autocrine, paracrine, or endocrine action and were reportedly suggested as "exercise factors" that can improve the brain function. However, several aspects remain to be elucidated, namely the specific activities of myokines related to the whole-body metabolism or brain function, the mechanisms of regulation of other organs or cells, the sources of "exercise factors" that regulate brain function, and their mechanisms of interaction with non-muscle organs. In this paper, we present the physiological functions of myokines secreted by exercise, including regulation of the whole-body metabolism by interaction with other organs and adaptation of skeletal muscles to exercise. In addition, we discuss the functions of myokines that possibly contribute to exercise-induced improvement of brain function. Among several myokines, brain-derived neurotrophic factor (BDNF) is the most studied myokine that regulates adult neurogenesis and synaptic plasticity. However, the source of circulating BDNF and its upstream effector, insulin-like growth factor (IGF-1), and irisin and the effect size of peripheral BDNF, irisin, and IGF-1 released after exercise should be further investigated. Recently, cathepsin B has been reported to be secreted from skeletal muscles and upregulate BDNF following exercise, which was associated with improved cognitive function. We reviewed the level of evidence for the effect of myokine on the brain function. Level of evidence for the association of the change in circulating myokine following exercise and improvement of neuropsychiatric function is lower than the level of evidence for the benefit of exercise on the brain. Therefore, more clinical evidences for the association of myokine release after exercise and their effect on the brain function are required. Finally, we discuss the effect size of the action of myokines on cognitive benefits of exercise, in addition to other contributors, such as improvement of the cardiovascular system or the effect of "exercise factors" released from non-muscle organs, particularly in patients with sarcopenia.

Lesions of epinephrine neurons in the rostral ventrolateral medulla abolish the vasodepressor components of baroreflex and cardiopulmonary reflex

Epinephrine-containing neurons of the rostral ventrolateral medulla (RVL) (the C1 group of Hökfelt) in the rat are primarily unilaterally innervated by neurons in the nucleus tractus solitarius (NTS) and in turn project to autonomic spinal neurons. In this study, we investigated whether the C1 area of the RVL mediates the vasodepressor responses (VDR) induced by either electrical stimulation of the vagus nerve or carotid sinus stretch. In all experiments, C1 neurons were localized immunocytochemically with antibodies to phenylethanolamine N-methyltransferase (PNMT). Bilateral lesions of the C1 area decreased arterial pressure (AP) and heart rate (HR) to spinal cord transection levels and blocked the VDR induced by vagal stimulation and carotid sinus stretch. Combined lesions of the contralateral NTS and C1 area ipsilateral to the stimulated vagus nerve maintained AP and HR at normal levels, and totally blocked the VDR to vagal stimulation and carotid sinus stretch. Since projections from the vagus nerve to NTS are bilateral and those from NTS to C1 unilateral, the combined contralateral NTS/ipsilateral C1 lesions isolated and interrupted the ipsilateral NTS-C1 pathway and, therefore, blocked the baroreceptor reflex. The results are consistent with the hypothesis that neurons in the NTS synapsing in or projecting through the C1 area mediate the baro- and cardiopulmonary mechanoreceptor reflex.

Impact of electrode composition on electricity generation in a single-compartment fuel cell using Shewanella putrefaciens

The production of electricity by Shewanella putrefaciens in the absence of exogenous electron acceptors was examined in a single compartment fuel cell with different types of electrodes and varying physiological conditions. Electricity production was dependent on anode composition, electron donor type and cell concentration. A maximum current of 2.5 mA and a current density of 10.2 mW/m(2)electrode was obtained with a Mn(4+) graphite anode, 200 mM sodium lactate and a cell concentration of 3.9 g cell protein/ml. Current production by S. putrefaciens was enhanced 10-fold when an electron mediator (i.e., Mn(4+) or neutral red) was incorporated into the graphite anode.

Outcomes of endoscopic transpapillary gallbladder stenting for symptomatic gallbladder diseases: a multicenter prospective follow-up study

BACKGROUND AND STUDY AIMS

Endoscopic transpapillary gallbladder drainage for symptomatic gallbladder disease is a safe and effective bridge therapy in patients at high risk for surgery or who have terminal liver disease and are awaiting transplantation. However, there are few reports on long-term results in terms of stent patency and clinical course. Our study was designed to investigate the long-term patency and clinical course after endoscopic transpapillary gallbladder stenting (ETGS) in patients with symptomatic gallbladder disease.

PATIENTS AND METHODS

A total of 29 patients who were unsuitable for cholecystectomy underwent ETGS from June 2006 to March 2010 using a 7-Fr double-pigtail stent between the gallbladder and the duodenum. Their clinical progress, adverse events, and stent patency after ETGS were recorded prospectively in two tertiary referral centers.

RESULTS

Technically, ETGS was successful in 23 (79.3%) of the 29 patients. The mean procedure time was 22.4 ± 11.5 min. Postprocedure adverse events were mild pancreatitis (8.7%) and cholestasis (8.7%), all of which resolved with conservative management. During the follow-up period (median 586 days, range 11-1403 days), 20 patients were analyzed as per protocol, and scheduled follow-up was performed. Late adverse events developed in four patients (20%), including distal migration (n = 2), cholangitis (n = 1), and recurrent biliary pain (n = 1). The remaining 16 patients were followed for more than 12 months (nine patients were followed for more than 24 months). Median stent patency was 760 days, as determined by the Kaplan-Meier method.

CONCLUSIONS

As a primary therapy, ETGS is technically feasible and effective in patients who are unsuitable for cholecystectomy. ETGS may also provide long-term stent patency without the need for scheduled stent exchanges.

Experimental Models of Sarcopenia: Bridging Molecular Mechanism and Therapeutic Strategy

Sarcopenia has been defined as a progressive decline of skeletal muscle mass, strength, and functions in elderly people. It is accompanied by physical frailty, functional disability, falls, hospitalization, and mortality, and is becoming a major geriatric disorder owing to the increasing life expectancy and growing older population worldwide. Experimental models are critical to understand the pathophysiology of sarcopenia and develop therapeutic strategies. Although its etiologies remain to be further elucidated, several mechanisms of sarcopenia have been identified, including cellular senescence, proteostasis imbalance, oxidative stress, and "inflammaging." In this article, we address three main aspects. First, we describe the fundamental aging mechanisms. Next, we discuss both in vitro and in vivo experimental models based on molecular mechanisms that have the potential to elucidate the biochemical processes integral to sarcopenia. The use of appropriate models to reflect sarcopenia and/or its underlying pathways will enable researchers to understand sarcopenia and develop novel therapeutic strategies for sarcopenia. Lastly, we discuss the possible molecular targets and the current status of drug candidates for sarcopenia treatment. In conclusion, the development of experimental models for sarcopenia is essential to discover molecular targets that are valuable as biochemical biomarkers and/or therapeutic targets for sarcopenia.

A dual role for the cAMP-dependent protein kinase in tyrosine hydroxylase gene expression

Tyrosine hydroxylase (TH) catalyzes the conversion of L-tyrosine to 3,4-dihydroxy-L-phenylalanine, the first and rate-limiting step in catecholamine biosynthesis. The cAMP-dependent protein kinase (PKA) phosphorylates and activates the TH enzyme and is thought to mediate transcriptional induction of the TH gene. To better understand the functional role of PKA in TH gene regulation, we studied TH gene expression at the transcriptional, translational, and post-translational levels in several PKA-deficient cell lines derived from rat PC12 pheochromocytoma cells. Strikingly, all PKA-deficient cell lines analyzed in this study showed substantial deficits in basal TH expression as measured by TH enzymatic activity, level of TH immunoreactivity, TH protein level, and steady-state mRNA level. Interestingly, the steady-state level of mRNA correlated well with levels of TH activity, immunoreactivity, and protein. In addition, PKA-deficient cell lines lacked transcriptional induction of the TH gene following treatment with dibutyryl cAMP. Cotransfection of PKA-deficient cells with an expression plasmid for the catalytic subunit of PKA fully reversed transcriptional defect, as indicated by robust transcriptional induction of a reporter construct containing 2400 bp of TH upstream sequence in all PC12 cells tested. These data indicate that the PKA system regulates both the basal and the cAMP-inducible expression of the TH gene primarily at the transcriptional level in PC12 cells.

Phenylethanolamine N-methyltransferase-containing neurons in the rostral ventrolateral medulla of the rat. I. Normal ultrastructure

The electron microscopic localization of the adrenaline-synthesizing enzyme, phenylethanolamine N-methyltransferase (PNMT) was examined in the rostral ventrolateral medulla (RVL) of adult rats. The brains were fixed by perfusion with 3.75% acrolein and 2.0% paraformaldehyde in phosphate buffer. Coronal Vibratome sections through the RVL were immunocytochemically labeled using a rabbit polyclonal antiserum to PNMT and the peroxidase-antiperoxidase method. A semi-quantitative ultrastructure analysis revealed that the perikarya constituted 9% of the total immunoreactive profiles observed in the RVL. The labeled somata were large (18-24 microns) and were characterized by an indented nucleus and abundant cytoplasm with numerous mitochondria. An average of 136.8 +/- 11.6 mitochondria were present per 100 microns2 cytoplasm, which is 38% greater than the numbers found for PNMT-immunoreactive neurons in the nucleus of the solitary tract. Moreover, the labeled somata were often found in direct apposition to the basal lamina of small capillaries and neighboring astrocytic processes. The remaining labeled profiles were neuronal processes of which 72% were dendrites. Both the PNMT-labeled somata and dendrites received primarily symmetric contacts from unlabeled axon terminals. Only a few axons and terminals containing immunoreactivity for PNMT were observed. The axons were both unmyelinated and myelinated. The PNMT-immunoreactive terminals were characterized by a mixed population of vesicles and by the formation of synaptic junctions with both unlabeled dendrites and PNMT-labeled perikarya and dendrites. The ultrastructural morphology and proximity to blood vessels and glia suggest a high metabolic activity and possibly a chemosensory function of PNMT neurons in the RVL. The existence of myelinated and unmyelinated axons could imply that PNMT-containing neurons have different conduction velocities in efferent pathways to the spinal cord or other brain regions. Furthermore, the multiple types of synaptic interactions between labeled and unlabeled axons and dendrites support the concept that adrenergic neurons modulate and are modulated by neurons containing the same or other putative transmitters in the RVL.