Study of termination of postprandial gastric contractions in humans, dogs and Suncus murinus: role of motilin- and ghrelin-induced strong contraction.

AIM: Stomach contractions show two types of specific patterns in many species, that is migrating motor contraction (MMC) and postprandial contractions (PPCs), in the fasting and fed states respectively. We found gastric PPCs terminated with migrating strong contractions in humans, dogs and suncus. In this study, we reveal the detailed characteristics and physiological implications of these strong contractions of PPC. METHODS: Human, suncus and canine gastric contractions were recorded with a motility-monitoring ingestible capsule and a strain-gauge force transducer. The response of motilin and ghrelin and its receptor antagonist on the contractions were studied by using free-moving suncus. RESULTS: Strong gastric contractions were observed at the end of a PPC in human, dog and suncus models, and we tentatively designated this contraction to be a postprandial giant contraction (PPGC). In the suncus, the PPGC showed the same property as those of a phase III contraction of MMC (PIII-MMC) in the duration, motility index and response to motilin or ghrelin antagonist administration. Ghrelin antagonist administration in the latter half of the PPC (LH-PPC) attenuated gastric contraction prolonged the duration of occurrence of PPGC, as found in PII-MMC. CONCLUSION: It is thought that the first half of the PPC changed to PII-MMC and then terminated with PIII-MMC, suggesting that PPC consists of a digestive phase (the first half of the PPC) and a discharge phase (LH-PPC) and that LH-PPC is coincident with MMC. In this study, we propose a new approach for the understanding of postprandial contractions.

Time-Reversal Measurement of the p-Wave Cross Sections of the

The cross sections of the ^{7}Be(n,α)^{4}He reaction for p-wave neutrons were experimentally determined at E_{c.m.}=0.20-0.81 MeV slightly above the big bang nucleosynthesis (BBN) energy window for the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the ^{7}Be(n,α)^{4}He reaction rate is not large enough to solve the cosmological lithium problem, and this conclusion agrees with the recent result from the direct measurement of the s-wave cross sections using a low-energy neutron beam and the evaluated nuclear data library ENDF/B-VII.1.

Increased ghrelin signaling prolongs survival in mouse models of human aging through activation of sirtuin1.

Caloric restriction (CR) is known to retard aging and delay functional decline as well as the onset of diseases in most organisms. Ghrelin is secreted from the stomach in response to CR and regulates energy metabolism. We hypothesized that in CR ghrelin has a role in protecting aging-related diseases. We examined the physiological mechanisms underlying the ghrelin system during the aging process in three mouse strains with different genetic and biochemical backgrounds as animal models of accelerated or normal human aging. The elevated plasma ghrelin concentration was observed in both klotho-deficient and senescence-accelerated mouse prone/8 (SAMP8) mice. Ghrelin treatment failed to stimulate appetite and prolong survival in klotho-deficient mice, suggesting the existence of ghrelin resistance in the process of aging. However, ghrelin antagonist hastened death and ghrelin signaling potentiators rikkunshito and atractylodin ameliorated several age-related diseases with decreased microglial activation in the brain and prolonged survival in klotho-deficient, SAMP8 and aged ICR mice. In vitro experiments, the elevated sirtuin1 (SIRT1) activity and protein expression through the cAMP-CREB pathway was observed after ghrelin and ghrelin potentiator treatment in ghrelin receptor 1a-expressing cells and human umbilical vein endothelial cells. Furthermore, rikkunshito increased hypothalamic SIRT1 activity and SIRT1 protein expression of the heart in the all three mouse models of aging. Pericarditis, myocardial calcification and atrophy of myocardial and muscle fiber were improved by treatment with rikkunshito. Ghrelin signaling may represent one of the mechanisms activated by CR, and potentiating ghrelin signaling may be useful to extend health and lifespan.

Rikkunshito induces gastric relaxation via the ß-adrenergic pathway in Suncus murinus.

BACKGROUND: Rikkunshito (RKT) is a gastroprotective herbal medicine. In this study, we investigated the role of RKT in the relaxation of the gastric body (fundus and corpus) and antrum. METHODS: We used Suncus murinus, a unique small model animal with similar gastrointestinal motility to humans and dogs. RKT was added at 0.1, 1.0, and 5.0 mg/mL to induce relaxation in vitro; the outcome measure was the intensity of relaxation. The number of spontaneous antral contractions in the absence or the presence of RKT was also counted. KEY RESULTS: Rikkunshito induced the relaxation of the gastric body and antrum and decreased the number of spontaneous antral contractions in a dose-dependent manner. The responses to RKT (1.0 mg/mL) were not affected by pretreatment with atropine, N-nitro-l-arginine methyl ester, ritanserin, or ondansetron. On the other hand, timolol almost completely reversed the relaxation induced by RKT (1.0 mg/mL) on the gastric body and antrum and the occurrence of the spontaneous antral contractions. Both butoxamine, a ß(2) -adrenoreceptor antagonist, and L 748337, a ß(3) -adrenoreceptor antagonist, but not CGP 20712, a ß(1) -adrenoreceptor antagonist, significantly reversed the RKT-induced (1.0 mg/mL) gastric relaxation. CONCLUSIONS & INFERENCES: These results indicate that RKT stimulates and modulates gastric relaxation through ß(2) - and ß(3) -adrenergic, but not ß(1) -adrenergic, pathways in S. murinus.

Neuroanatomical and functional characterization of CRF neurons of the amygdala using a novel transgenic mouse model.

The corticotropin-releasing factor (CRF)-producing neurons of the amygdala have been implicated in behavioral and physiological responses associated with fear, anxiety, stress, food intake and reward. To overcome the difficulties in identifying CRF neurons within the amygdala, a novel transgenic mouse line, in which the humanized recombinant Renilla reniformis green fluorescent protein (hrGFP) is under the control of the CRF promoter (CRF-hrGFP mice), was developed. First, the CRF-hrGFP mouse model was validated and the localization of CRF neurons within the amygdala was systematically mapped. Amygdalar hrGFP-expressing neurons were located primarily in the interstitial nucleus of the posterior limb of the anterior commissure, but also present in the central amygdala. Secondly, the marker of neuronal activation c-Fos was used to explore the response of amygdalar CRF neurons in CRF-hrGFP mice under different experimental paradigms. C-Fos induction was observed in CRF neurons of CRF-hrGFP mice exposed to an acute social defeat stress event, a fasting/refeeding paradigm or lipopolysaccharide (LPS) administration. In contrast, no c-Fos induction was detected in CRF neurons of CRF-hrGFP mice exposed to restraint stress, forced swimming test, 48-h fasting, acute high-fat diet (HFD) consumption, intermittent HFD consumption, ad libitum HFD consumption, HFD withdrawal, conditioned HFD aversion, ghrelin administration or melanocortin 4 receptor agonist administration. Thus, this study fully characterizes the distribution of amygdala CRF neurons in mice and suggests that they are involved in some, but not all, stress or food intake-related behaviors recruiting the amygdala.

Myenteric neural network activated by motilin in the stomach of Suncus murinus (house musk shrew).

BACKGROUND: It has been shown in human and canine studies that motilin, a gastroprokinetic hormone, induces gastric phase III contractions via the enteric nervous; however, the center of motilin action in the stomach has not been clearly revealed. In the present study, we investigated the neural pathway of motilin-induced gastric contraction by using Suncus murinus, a new animal model for motilin study. METHODS: An isolated suncus stomach was used in vitro to determine the mechanism of motilin action through the myenteric plexus. Synthetic suncus motilin (10(-11) -10(-7) molL(-1) ) was added to an organ bath, and the spontaneous contraction response was expressed as a percent of ACh (10(-5) molL(-1) ) responses. Motilin-induced contractions were also studied by a pharmacological method using several receptor antagonists and enzyme inhibitor. KEY RESULTS: Suncus motilin induced a concentration-dependent gastric contraction at concentrations from 10(-9) to 10(-7) molL(-1) . The responses to suncus motilin in the stomach were completely abolished by atropine and tetrodotoxin treatment and significantly suppressed by administration of hexamethonium, verapamil, phentolamine, yohimbine, ondansetron, and naloxone, whereas ritanserin, prazosin, timolol, and FK888 did not affect the action of motilin. Additionally, N-nitro l-arginine methylester slightly potentiated the contractions induced by motilin. CONCLUSIONS & INFERENCES: The results indicate that motilin directly stimulates and modulates suncus gastric contraction through cholinergic, adrenergic, serotonergic, opioidergic, and NO neurons in the myenteric plexus.

Distribution and neurochemical characterization of protein kinase C-theta and -delta in the rodent hypothalamus.

PKC-theta (PKC-θ), a member of the novel protein kinase C family (nPKC), regulates a wide variety of functions in the periphery. However, its presence and role in the CNS has remained largely unknown. Recently, we demonstrated the presence of PKC-θ in the arcuate hypothalamic nucleus (ARC) and knockdown of PKC-θ from the ARC protected mice from developing diet-induced obesity. Another isoform of the nPKC group, PKC-delta (PKC-δ), is expressed in several non-hypothalamic brain sites including the thalamus and hippocampus. Although PKC-δ has been implicated in regulating hypothalamic glucose homeostasis, its distribution in the hypothalamus has not previously been described. In the current study, we used immunohistochemistry to examine the distribution of PKC-θ and -δ immunoreactivity in rat and mouse hypothalamus. We found PKC-θ immunoreactive neurons in several hypothalamic nuclei including the ARC, lateral hypothalamic area, perifornical area and tuberomammillary nucleus. PKC-δ immunoreactive neurons were found in the paraventricular and supraoptic nuclei. Double-label immunohistochemisty in mice expressing green fluorescent protein either with the long form of leptin receptor (LepR-b) or in orexin (ORX) neurons indicated that PKC-θ is highly colocalized in lateral hypothalamic ORX neurons but not in lateral hypothalamic LepR-b neurons. Double-label immunohistochemistry in oxytocin-enhanced yellow fluorescent protein mice or arginine vasopressin-enhanced green fluorescent protein (AVP-EGFP) transgenic rats revealed a high degree of colocalization of PKC-δ within paraventricular and supraoptic oxytocin neurons but not the vasopressinergic neurons. We conclude that PKC-θ and -δ are expressed in different hypothalamic neuronal populations.

Diurnal change of thyroid-stimulating hormone mRNA expression in the rat pars tuberalis.

Thyroid-stimulating hormone (TSH)-producing cells (TSH cells), which account for a large fraction of the cells in the rat pars tuberalis (PT), have been found to express MT1 melatonin receptor and mammalian clock genes at high densities. Although these findings suggest that TSH production in the rat PT is regulated by melatonin and/or the biological clock, there have been no studies focusing on the diurnal change and regulation mechanism of TSH production in the rat PT. Therefore, in the present study, we examined diurnal changes of in TSH beta and alpha-glycoprotein subunit (alpha GSU) mRNA expression and TSH immunoreactivity (-ir) in the rat PT, and also examined the relationship between melatonin and TSH production in vivo. Both TSH beta mRNA expression and alpha GSU mRNA expression in the PT showed diurnal variations: the expression levels were lowest at the light phase [Zeitgeber time (ZT)4] and high at the dark phase (ZT12 and ZT20). TSH-ir in the PT showed the lowest level at ZT4, as was found for mRNA expression. Interestingly, TSH-ir, which was confined to the Golgi apparatus at ZT4, spread to the cytoplasm, and most of the TSH cells in the PT were uniformly immunostained in the cytoplasm at ZT20. Despite the fact that chronic administration of melatonin suppressed TSH beta and alpha GSU mRNA expression, TSH-ir in the PT was significantly enhanced. These findings results clearly show that there are diurnal changes in TSH expression and accumulation in rat PT-TSH cells and suggest that these fluctuations are regulated by melatonin.

Optic nerve hyperintensity on T2-weighted images among patients with pituitary macroadenoma: correlation with visual impairment.

PURPOSE: Visual acuity (VA) disturbance other than field defect is important in evaluating patients with pituitary macroadenoma. The purpose of this study was to evaluate MR imaging appearances of optic nerves in patients with pituitary macroadenoma and to ascertain whether visual impairment was correlated with abnormality in optic nerve signal intensity. PATIENTS AND METHODS: Twenty-seven patients with pituitary macroadenoma were examined. Optic nerves were evaluated on T2-weighted images and correlations of signal intensity abnormality with VA disturbance, visual field disturbance, degree of optic chiasm compression, pathologic findings of surgical specimen, and disease duration were statistically analyzed. Correlations between recovery of VA after treatment and the above-mentioned factors were also determined. RESULTS: Coronal T2-weighted images demonstrated unilateral optic nerve hyperintensity lesions in 9 patients. Bilateral signal intensity abnormality of the optic nerve was seen in 5 patients. Signal intensity abnormality of the optic nerve was seen at the site of compression and in the ventral side of the tumor. These patients did not demonstrate signal intensity abnormality posterior to the tumor. Presence of such signal intensity abnormalities was correlated with the degree of optic chiasmal compression and with VA disturbance. Recovery of VA after treatment was correlated with disease duration. CONCLUSION: Hyperintensity of the optic nerves ventral to the pituitary macroadenoma was associated with VA impairment. Recovery of VA after treatment was correlated with disease duration. MR imaging of the optic nerves can provide valuable information for management of pituitary macroadenoma.

ATX-S10(Na)-photodynamic therapy is less carcinogenic for mouse skin compared with ultraviolet B irradiation.

BACKGROUND: Photodynamic therapy (PDT) is available for the treatment of various skin tumours and other skin diseases. Ultraviolet (UV) irradiation induces DNA damage, cyclobutane pyrimidine dimers (CPD) (6-4) photoproducts (6-4PP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), all of which are carcinogenic for the skin. However, effects of PDT on DNA damage and carcinogenesis are unclear. OBJECTIVES: To compare the production of photoproducts and the induction of skin tumours in mouse epidermis treated with UVB or PDT. METHODS: We performed UVB irradiation or ATX-S10(Na)-PDT on the skin of 20 hairless mice, in each case, and analysed DNA damage and tumour induction. RESULTS: After a single irradiation of UVB on mouse skin, CPD, 6-4PP and 8-OHdG were detected in the nuclei of keratinocytes. In contrast, PDT-treated mouse keratinocytes showed induction of 8-OHdG, but not of CPD or 6-4PP. Skin tumours induced by UVB irradiation (3 kJ m(-2) three times weekly) were observed following 15 weeks of irradiation (mean +/- SEM tumour incidence 3.2 +/- 1.8%; tumour number 3.2 +/- 1.6 per mouse) and increased depending on irradiation times and doses. Following 30 weeks of UVB irradiation (3 kJ m(-2) three times weekly), mean +/- SEM tumour incidence and tumour number were 28.7 +/- 4.8% and 14.2 +/- 2.8% per mouse, respectively. Although skin tumours were also detected in PDT-treated mouse skin following 80 weeks of treatment (mean +/- SEM tumour incidence 9.1 +/- 1.8%; tumour number 12.2 +/- 2.3 per mouse), the number of tumours was not statistically different from untreated mouse skin (mean +/- SEM tumour incidence 4.1 +/- 3.8%; tumour number 5.2 +/- 3.3 per mouse). CONCLUSIONS: PDT induced 8-OHDG but not CPD or 6-4PP, and was shown to be a relatively safe modality following multiple applications to mouse skin.

Comparison of nonmetal and metal hydrophilic photosensitizer, ATX-S10 (Na) and ATN-2, binding with human serum proteins using spectrophotometry.

Intermolecular interactions of human serum proteins with a hydrophilic nonmetalloporphyrin, 13,17-bis(1-carboxypropionyl)carbomoylethyl-8-ethenyl-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetramethylporphyrin sodium salt (ATX-S10 (Na)), or a hydrophilic gallium-metalloporphyrin, diethylenetriamine pentaacetic acid ester of 2-[1-(2-hydroxy-ethoxy)ethyl]-4-vinyl-deuteroporphyrin (IX) Ga complex (ATN-2), were investigated using spectrophotometry. ATX-S10 (Na) caused a bathochromic shift with albumin, high-density lipoprotein and low-density lipoprotein, but little or no shift was observed with hemopexin, transferrin and immunoglobulin G. In contrast, ATN-2 displayed a bathochromic shift only with hemopexin. These results suggest that the association energy of ATX-S10 (Na) with albumin might be slightly greater than that with lipoproteins and that of ATN-2 with hemopexin might be greater than that with other serum proteins.

Fluorescence detection of a new photosensitizer, PAD-S31, in tumour tissues and its use as a photodynamic treatment for skin tumours in dogs and a cat: a preliminary report.

We describe here the detection by fluorescence of a new photosensitizer, PAD-S31, in tumours in dogs and cats and the effect of photodynamic therapy (PDT) by using PAD-S31 for skin tumours in two dogs and one cat. PAD-S31 is a hydrophilic photosensitizer that has two peaks at absorption wavelengths 406 and 665 nm in distilled water. In a preliminary experiment in mice transplanted with SCCVII and colon 26, PAD-S31 was retained in tumour tissues rather than in other organs. The tumours resected from dogs and cats after intravenous administration of PAD-S31 at a dose of 15 mg/kg emitted strong red fluorescence under light illumination of 402 nm wavelength. Animals given PAD-S31 showed no cutaneous photosensitivity under room light illumination. Irradiation at laser light 670 nm wavelength (fluence rate 150 mW/cm2 and total light dosage 150 J/cm2) on cutaneous mast cell tumours in dogs ( n=2 ) and a cutaneous basal cell tumour in a cat induced complete remission. These results suggest PAD-S31 could be a promising photosensitizer for use in a small animal veterinary practice.

Treatment of portal vein septic thrombosis by infusion of antibiotics and an antifungal agent into portal vein and superior mesenteric artery: a case report.

A 44-year-old man was hospitalized because of right-sided abdominal pain and fever. On admission, he presented spike fever, jaundice, and renal failure. Abdominal ultrasonography and computed tomography showed extensive thrombus in the portal vein. Anaerobic bacteria were identified in arterial and portal blood cultures. Based on these findings, septic thrombosis of the portal vein was diagnosed. Intraportal infusion of antibiotics, urokinase and an antifungal agent, followed by infusion of antimicrobials, urokinase, and heparin into the superior mesenteric artery resulted in marked improvement of symptoms and signs. Diverticulitis of the ascending colon was later found to be the underlying disease. In the follow-up, there were no signs of recurrent disease.

Postnatal changes in ghrelin mRNA expression and in ghrelin-producing cells in the rat stomach.

Ghrelin was recently isolated from the rat stomach as an endogenous ligand for the GH secretagogue receptor. Although it is well known that a large amount of ghrelin is produced in the gastrointestinal tract, developmental changes in ghrelin mRNA expression and differentiation of ghrelin-immunopositive (ghrelin-ip) and mRNA-expressing (ghrelin-ex) cells in the stomach have not been elucidated. In this study, we therefore investigated the changes in ghrelin mRNA expression levels and in the numbers of ghrelin-ip and -ex cells in the stomachs of 1- to 8-week-old male and female rats by Northern blot analysis, immunohistochemistry and in situ hybridization. Northern blot analysis showed that the level of weak ghrelin mRNA expression was low in the postnatal period but then increased in a dimorphic pattern, i.e. transient stagnation at 4 weeks in the male rats and at 5 weeks in the female rats. The number of ghrelin-ip and ghrelin-ex cells also increased after birth, and more numerous ghrelin cells were found in female rats than in male rats, and this finding was confirmed by Northern blot analysis. Ghrelin-ip and -ex cells first appeared in the glandular base of the fundic gland and then they were found in the glandular base and the glandular neck at 3 weeks of age, suggesting that the distribution of ghrelin cells is extended from the glandular base to the glandular neck during the postneonatal development period. This is the first report on detailed changes in postneonatal ghrelin expression level and in the number of ghrelin cells in the rat stomach. The sexual dimorphism of ghrelin expression and ghrelin cell differentiation suggest that ghrelin plays an important physiological role in the stomach.

Pharmacokinetic study of a gallium-porphyrin photo- and sono-sensitizer, ATX-70, in tumor-bearing mice.

The tissue distribution of a gallium-porphyrin photo- and sono-sensitizer, 7,12-bis(1-decyloxyethyl)-Ga(III)-3,8,13,17-tetramethylporphyrin-2,18-dipropionyldiaspartic acid, ATX-70, was pharmacokinetically examined in tumor-bearing mice. The drug was administered intravenously to CDF(1) mice implanted with Colon 26 carcinoma. Blood and tissue samples were collected for up to 72 h after administration. The drug concentration was determined by high-performance liquid chromatography (HPLC) with fluorescence detection. ATX-70 was found to accumulate in tumors at a relatively high concentration that peaked between 2 h and 6 h after administration. However, modest concentrations of ATX-70 also remained in healthy tissues for up to 6 h. We examined the distribution of ATX-70 in the tumor in comparison with other tissues from the viewpoint of minimizing possible side effects of laser or ultrasound exposure while maintaining the treatment effect. About 24 h after administration, the tumor / plasma concentration ratio peaked, and relatively high tumor / skin and tumor / muscle concentration ratios were seen.

Tumour enhancement with newly developed Mn-metalloporphyrin (HOP-9P) in magnetic resonance imaging of mice.

The purpose of the study is to evaluate the tumour enhancing characteristics and biodistribution of a newly developed metalloporphyrin derivative, HOP-9P (13, 17-bis (1-carboxypropionyl) carbamoylethyl-3, 8-bis (1-phenylpropyloxyethyl)-2,7,12,18-tetra- methyl-porphynato manganese (III)). Seven mice bearing SCC VII tumours were imaged using T1-weighted conventional spin echo magnetic resonance images before and 5 min, 2 h and 24 h after intravenous injection of 0.1 mmol/kg of HOP-9P. For the acquired images, signal intensities of the tumour, muscle and oil-phantom were measured. Then, tumor/oil and tumor/muscle signal intensity ratios were calculated. Nineteen mice were sacrificed before or after the administration of HOP-9P (at 5 min, 2 h and 24 h), and the biodistribution of manganese in the tumour, muscle, liver, blood and kidneys was measured using optical emission spectrometers and was expressed as micrograms of manganese per gram of tissue. The tumour/muscle signal intensity ratio at 24 h (3.18 +/- 0.34) was significantly higher than precontrast ratio (1.77 +/- 0.20) (P < 0.05). The biodistribution assessment of manganese demonstrated that HOP-9P gradually and consistently accumulated in the tumour to reach the highest concentration at 24 h (3.49 +/- 1.22 micro gMn/g). It is concluded that HOP-9P is a potential tumour-specific MR contrast agent.

Novel glomerular lipoprotein deposits associated with apolipoprotein E2 homozygosity.

BACKGROUND: Hyperlipoproteinemia is occasionally associated with severe glomerular injury caused by abnormal accumulation of lipid in glomeruli, which occurs in conditions such as lipoprotein glomerulopathy (LPG). This study investigates the cases of two siblings with homozygous apolipoprotein (apo) E2 who show unique histologic features, massive proteinuria, and dysbetalipoproteinemia. METHODS: Histologic studies were performed using renal biopsy specimens. Plasma lipoproteins were extensively characterized. The exons of the apo E genes were sequenced to avoid missing any mutations. RESULTS: Histologically, the siblings' condition resembled LPG by light microscopy studies. Electron microscopy studies revealed large lipoid deposits in the paramesangium, subendothelium, and subepithelium of the glomeruli, which were different from LPG in terms of not forming the layered structure resembling a fingerprint even in large lipoprotein thrombi, and mesangial foam cells. Immunohistochemically, the lipoid deposits contained apo E and apo B. These patients did not have either diabetic nephropathy or other known forms of glomerulonephritis. The sequence of exons of the apo E genes revealed homozygosity for apo E2 in both cases. CONCLUSION: The extensive lipoprotein deposition in glomeruli, which resembles LPG, can also occur in apo E2 homozygous individuals, but in a distinct fashion. Because the two cases were siblings, they may have other shared alleles, in addition to the apo E2 allele, that negatively affect processing of lipoproteins and lead to abnormal accumulation of lipoprotein deposits in glomeruli.

Competitive uptake of porphyrin and LDL via the LDL receptor in glioma cell lines: flow cytometric analysis.

We examined the simultaneous uptake of porphyrin and (LDL) by four established cell lines of glioma and normal fibroblasts using flow cytometry (FCM). The results indicated porphyrin and LDL showed competitive conjugation with the LDL receptor. These results support the theory of the porphyrin uptake via the LDL receptor.