Suppression of the morphine-induced rewarding effect and G-protein activation in the lower midbrain following nerve injury in the mouse: involvement of G-protein-coupled receptor kinase 2

The present study was designed to investigate whether a state of neuropathic pain induced by sciatic nerve ligation could alter the rewarding effect, antinociception, and G-protein activation induced by a prototype of mu-opioid receptor agonist morphine in the mouse. The sciatic nerve ligation caused a long-lasting and profound thermal hyperalgesia. Under this neuropathic pain-like state, an i.c.v. morphine-induced place preference was observed in sham-operated mice but not in sciatic nerve-ligated mice. However, no differences in the antinociceptive effect of i.c.v.-administered morphine were noted between the groups. The increases in the binding of guanosine-5'-o-(3-[(35)S]thio)triphosphate induced by morphine in lower midbrain membranes including the ventral tegmental area, which contributes to the expression of the rewarding effect of opioid, were significantly attenuated in sciatic nerve-ligated mice. On the other hand, there were no differences in the stimulation of guanosine-5'-o-(3-[(35)S]thio)triphosphate binding to pons/medulla membranes, which plays an important role in the antinociception of mu-opioid receptor agonists, between the groups. In addition, no changes in levels of guanosine-5'-o-(3-[(35)S]thio)triphosphate binding by either the selective delta- or kappa-opioid receptor agonists were noted in membrane of the lower midbrain and limbic forebrain membranes obtained from sciatic nerve-ligated mice. Reverse transcription-polymerase chain reaction analysis showed that sciatic nerve ligation did not alter the mRNA product of mu-opioid receptors in the lower midbrain, indicating that a decrease in some mu-opioid receptor functions may result from the uncoupling of mu-opioid receptors from G-proteins. We found a significant increase in protein levels of G-protein-coupled receptor kinase 2, which causes receptor phosphorylation in membranes of the lower midbrain but not in the pons/medulla, obtained from mice with nerve injury, whereas there were no changes in the protein level of phosphorylated-protein kinase C in the lower midbrain. These results suggest that the uncoupling of mu-opioid receptors from G-proteins by G-protein-coupled receptor kinase 2 in the lower midbrain may, at least in part, contribute to the suppression of the rewarding effect of morphine under neuropathic pain.

A case of concurrent vitiligo vulgaris and polymyositis

Abstract  We present a rare case of simultaneous muscle weakness and cutaneous depigmentation. Muscle and skin biopsies confirmed the diagnosis of polymyositis and generalized vitiligo vulgaris. All symptoms improved after steroid therapy. Immunohistochemical analyses revealed predominant CD8-positive T cell infiltration in both muscular and cutaneous lesions. This case suggests that a common autoimmune mechanism mediated by cytotoxic T lymphocytes underlies the pathogeneses of these two diseases.

Leptin inhibits stress-induced apoptosis of T lymphocytes

Leptin, which is secreted by adipocytes, the placenta and the stomach, not only controls appetite through leptin receptors in the hypothalamus but also regulates cell-mediated immunity. In this study we have demonstrated that continuous injection of leptin prevents the reduction in lymphocyte numbers normally observed in fasted and steroid-injected mice. Consistent with leptin-induced protection, we observed up-regulation of the bcl-xL gene as a result of signal transduction via leptin receptors on lymphocytes. We suggest that leptin might contribute to the recovery of immune suppression in malnourished mice by inhibiting lymphocyte apoptosis.

Mechanism of opioid dependence and interaction between opioid receptors

Clinical studies have demonstrated that when opiates are used to control cancer pain, psychological dependence and analgesic tolerance are not a major concern. The present study was, therefore, designed to investigate the modulation of rewarding effects of opiates under inflammatory chronic pain. Formalin or carrageenan was injected into the plantar surface of the rat paw. Formalin and carrageenan reduced the paw pressure threshold. The hyperalgesia lasted for 9-13 days. The rewarding effect of morphine was evaluated by conditioned place preference paradigm. Morphine produced a significant place preference. This effect was significantly attenuated in inflamed groups compared with the respective non-inflamed groups. Furthermore, the morphine-induced place preference in the inflamed group gradually recovered to the respective control level as the inflammation healed. We also found that kappa-receptor agonists markedly inhibited the rewarding effect of mu-receptor agonists. Therefore, to elucidate the mechanism of this attenuation, the effects of pretreatment with kappa- and delta-receptor antagonists, nor-binaltorphimine (nor-BNI) and naltrindole (NTI), on the development of the morphine-induced place preference under inflammation were examined. Nor-BNI, but not NTI, eliminated the suppression of the morphine-induced place preference in inflamed groups. The morphine-induced increase in dopamine (DA) turnover in the limbic forebrain was suppressed under inflammation, and the suppression was abolished by the pretreatment with nor-BNI. These results suggest that endogenous kappa-opioid systems may be activated by chronic inflammatory nociception, and then the activation of kappa-opioid system may inhibit DA release in nucleus accumbens, resulting in the suppression of the development of rewarding effects produced by morphine.

Drug-induced neutropenia associated with anti-neutrophil cytoplasmic antibodies (ANCA): possible involvement of complement in granulocyte cytotoxicity

Although antineutrophil antibodies are thought to be involved in drug-induced neutropenia, neither the precise mechanisms nor the particular antigens on the neutrophil surface have yet been clarified. Recently, we examined a patient with Graves' disease who developed antineutrophil cytoplasmic antibodies (ANCA) after propylthiouracil treatment and exhibited neutropenia. Because several target antigens of ANCA are expressed on the surface of neutrophils, it was suggested that ANCA might contribute to neutropenia. The patient's serum bound specifically to neutrophils and HL-60 cells differentiated into granulocytes, and lysed the HL-60 cells via a complement-mediated mechanism. Furthermore, two representative ANCA antigens, proteinase 3 and myeloperoxidase, significantly inhibited both the binding and cytotoxicity of the serum. Finally, tumour necrosis factor-alpha, which is known to up-regulate cell surface expression of several ANCA antigens, enhanced both the binding and cytotoxicity of the serum. These findings suggest that ANCA induced by propylthiouracil contributed to leucopenia through a complement-mediated mechanism.

Influence of design and fixation pressure on fibrous sheathing in right-sided porcine aortic bioprostheses

Valve dysfunction in right side implanted bioprostheses can be caused by fibrous sheathing and cusp retraction. A scoring system was employed to grade the macroscopic appearance of the cusp retraction. Stentless porcine aortic valves exhibit less cusp retraction when implanted in right-sided position than stented porcine aortic valves.

Lack of calcification of tissue engineered heart valves in juvenile sheep

The presence of viable endothelial cells may support longer durability and the absence of calcification in valve prostheses. This study shows the development of a tissue engineered heart valve, constructed from viable autologous endothelial cells on an acellular matrix and its evaluation in juvenile sheep. In 3-month-old sheep (n = 8) a piece of vein was harvested to culture autologous endothelial cells. A porcine acellular matrix was reendothelialized and implanted in juvenile sheep as pulmonary interposition. The valves were explanted after 1 week, 3 and 6 months. Examination was performed by X-ray, light microscopy, and atomic absorption spectrometry. Reendothelialization mean rate was 10.3 x 10(5) cells/cm(2) with a mean endothelial cell viability of 95.5% (0.98 x 10(5) cells/cm(2)). X-ray examination showed no cusp calcification at 1 week, 3 and 6 months, which was confirmed by light microscopy. Immunostaining for factor VIII demonstrated colonization of viable mature autologous endothelial cells on the heart valve after the seeding process. The atomic absorption spectrometry showed no significant increase of the calcium content after 3 (P value >.1) and 6 months (P value >.1) compared with nonimplanted tissue engineered heart valves. The tissue engineered valve showed no cusp calcification in the juvenile sheep after 3 and 6 months.

Influence of species, environmental factors, and tissue cellularity on calcification of porcine aortic wall tissue

Valve tissue calcification has complex host, implant, and mechanical determinants. We studied the influence of species (rat v sheep), environmental factors (presence v absence of blood contact and arterial stress), and tissue cellularity (normal v acellularized tissue) on porcine aortic wall mineralization. Porcine aortic wall samples underwent standard glutaraldehyde-fixation or combined enzyme-detergent acellularization. Samples were implanted subcutaneously in rats (n = 8) and in juvenile sheep (n = 8). Furthermore, in juvenile sheep, similar samples were implanted into the jugular vein (blood contact) and into the carotid artery (blood contact and arterial stress). After 8 and 12 weeks, tissue was explanted and evaluated by X-ray, light- and electron-microscopy, and calcium content measurement (atomic absorption spectrometry). On the Von Kossa staining, auto-fluorescence of elastic fibers was used to identify the relation between calcific deposits and elastin. Subcutaneously implanted, glutaraldehyde-fixed tissue calcified severely in rat, but much less in sheep (calcium content: 56.2 +/- 13.6 v 9.9 +/- 9.0 microg/mg, respectively; P <.001). In sheep, the presence of blood contact (venous implants) increased wall calcification significantly (36.9 +/- 15.8; P <.001), but hemodynamic stress (arterial implants) had no additional mineralizing effect on the aortic wall (P >.05 v venous implants). Calcification of glutaraldehyde-fixed tissue occurred predominantly at the level of cells and cellular remnants, as confirmed by electron- and fluorescence-microscopy, locating calcific deposits in between elastic fibers. Acellularized tissue calcified significantly less, but an inflammatory response towards the tissue led to fragmentation, lysis, and subsequent calcification of elastic fibers. Results from subcutaneous implantations show large inconsistencies in calcification between the species. In sheep, blood contact increases aortic wall calcification significantly, while arterial stress has no additional effect. The sheep-jugular implantation model can be used as a simplified model for further study of aortic wall calcification and new antimineralization treatments. Calcification of glutaraldehyde-fixed aortic wall tissue is initiated at the level of cellular remnants, with little or no contribution from elastic fibers. Acellularization can avoid this cell-mediated calcification, but an additional treatment (glutaraldehyde, cryopreservation, photo-fixation,.) will be necessary to avoid the inflammation leading to elastolysis and consequent calcification of elastic fibers.

Different motivational effects induced by the endogenous mu-opioid receptor ligands endomorphin-1 and -2 in the mouse

The present study was designed to investigate the motivational effects of the newly discovered endogenous mu-opioid receptor ligands, endomorphin-1 and endomorphin-2, using the conditioned place preference paradigm in mice. The binding properties of these peptides were first examined using an opioid binding assay. In membranes obtained from the mouse whole brain, the binding of [3H][D-Ala2, NMePhe4, Gly(ol)5]enkephalin (DAMGO; mu), but not of [3H][D-Phe2, D-Phe5]enkephalin (DPDPE; delta) or [3H]U69593 (kappa) selectively and concentration-dependently competed with that of endomorphin-1 and endomorphin-2, indicating that both endomorphin-1 and endomorphin-2 are specific ligands for mu-opioid receptors in the brain. Endomorphin-1 (1-30 nmol/mouse) given i.c.v. produced a dose-related place preference. This effect was abolished by pre-treatment with the mu-opioid receptor antagonist beta-funaltrexamine but not the delta-opioid receptor antagonist naltrindole or the kappa-opioid receptor antagonist nor-binaltorphimine. In contrast, endomorphin-2 (5.6 nmol/mouse) produced place aversion. This aversive effect was inhibited by nor-binaltorphimine as well as beta-funaltrexamine, but not by naltrindole. The place aversion produced by endomorphin-2 was also attenuated by pre-treatment with antiserum against the endogenous kappa-opioid receptor ligand dynorphin A (1-17). These findings indicate that endomorphin-1 may produce its rewarding effect via mu-opioid receptors. On the other hand, the aversive effect induced by endomorphin-2 may be associated with the stimulation of endomorphin-1-insensitive mu-opioid receptors and the activation of dynorphinergic systems in the mouse brain.

Observation of the "self-healing" of an error field island in the large helical device

It was observed that the vacuum magnetic island produced by an external error magnetic field in the large helical device shrank in the presence of plasma. This was evidenced by the disappearance of flat regions in the electron temperature profile obtained by Thomson scattering. This island behavior depended on the magnetic configuration in which the plasmas were produced.

The activation of molecular oxygen by horseradish peroxidase with sodium sulfite

Horseradish peroxidase (HRP) utilizes molecular oxygen (O2) with sodium sulfite (Na2SO3) to oxidize thioanisole and styrene at the exterior of the heme pocket.

[Basic research for psychological dependence on morphine under chronic pain]

Morphine is clinically superior in relieving severe pain such as cancer pain. However, considering misplaced fears of the dangers of dependence potential and abuse liability, doctors have hesitated to treat patients with morphine. Recent clinical studies have clearly demonstrated that when opiates including morphine are used to control pain, psychological dependence is not a major concern. The present study was then designed to investigate the rewarding effects induced by morphine under chronic pain by inflammatory and neuropathic pain in rodents. Furthermore, we also investigated whether any biological changes to interfere with the effects of morphine could be seen under chronic pain.

Successful emergency endometrial ablation for intractable uterine bleeding in a postmenopausal woman complicated with liver cirrhosis and morbid obesity

Life-threatening intractable uterine bleeding is difficult to treat when concurrent medical complications contraindicate invasive surgery. We present a case of heavy uterine bleeding in a postmenopausal woman that was complicated by liver cirrhosis and morbid obesity. The bleeding was successfully halted through emergency endometrial ablation after failure of uterine artery embolization.

Intercellular adhesion molecule-1 in patients with idiopathic interstitial pneumonia

This study focuses on a possible role of intercellular adhesion molecule-1 (ICAM-1) in interstitial pulmonary diseases. We determined a soluble form of ICAM-1 in serum and bronchoalveolar lavage fluid (BALF) using ELISA in patients with usual interstitial pneumonia (UIP), bronchiolitis obliterance organizing pneumonia (BOOP), or nonspecific interstitial pneumonia (NSIP). In addition, we investigated the expression of ICAM-1 in the lung tissues of these patients by means of immunohistochemical staining. Serum levels of soluble ICAM-1 were significantly higher in patients with UIP or NSIP than in healthy subjects, and were also high in patients with BOOP. The soluble ICAM-1 in BALF tended to be higher in patients with UIP, BOOP, or NSIP than in normal subjects. A significant correlation was seen between soluble levels of ICAM-1 in serum and BALF. In the immunostaining of ICAM-1 of the lung tissues, ICAM-1 expression was more pronounced in patients with UIP than in those with BOOP or NSIP. The increased expression of ICAM-1 was seen in type II alveolar epithelium and vascular endothelium in patients with interstitial pneumonia. A positive correlation was observed between the degree of ICAM-1 expression in the lung tissues and the BALF levels of soluble ICAM-1. The expression of ICAM-1 in type II alveolar epithelium suggests that ICAM-1 plays a specific role in the fibrotic process of the lung, and that the measurement of soluble ICAM-1 in sera and BALF could be a useful marker for evaluating the progression of fibrosis.

Lack of the involvement of mu1-opioid receptor subtype on motivational effects induced by the endogenous mu-opioid receptor ligands endomorphin-1 and -2 in the mouse

The present study was designed to investigate the role of mu-opioid receptor subtypes in the motivational effect of endogenous mu-opioid receptor ligands, endomorphin-1 and -2. In C57BL/6J mice, endomorphin-1 produced a significant place preference, whereas endomorphin-2 exhibited a significant place aversion. These effects were abolished by a mu1/mu2-opioid receptor antagonist beta-funaltrexamine. Under these conditions, both endomorphin-1 and -2 produced their motivational effects in mu1-opioid receptor-deficient CXBK mice, indicating the mu2-opioid receptor involvement. Furthermore, in the lower midbrain including ventral tegmental area, both endomorphin-1 and -2 equally produced dose-related increases in guanosine-5'-o-(3-[35S] thio) triphosphate bindings in C57BL/6J and CXBK mice. These findings indicate that endomorphin-1 and -2 may produce distinct motivational effects via respective mu2-opioid receptor isoforms in the mouse. Furthermore, endomorphin-1 and -2 produced the mu1-resistant G-protein activation in the mouse lower midbtrain.

Antimineralization treatments in stentless porcine bioprostheses: an experimental study

BACKGROUND AND AIM OF THE STUDY

Photo-oxidation treatment of porcine stentless bioprostheses (Photofix) was compared with glutaraldehyde fixation, with either AOA (Freestyle valve) or Tween-80 (Edwards Prima Plus valve).

METHODS

Six valves of each type were implanted in juvenile sheep, in the pulmonary position. Valves were explanted after three or six months and examined macroscopically, by X-radiography, and by light and transmission electron microscopy. Calcium content was determined by atomic absorption spectrometry.

RESULTS

The cusps of all valves were free of calcification, and had normal histology and function. Calcium contents (median +/- IQR) were 0.63+/-0.45, 0.73+/-1.46 and 0.46+/-1.42 microg/mg for the Photofix, Freestyle and Prima Plus valves, respectively (p = NS). Calcium contents of the aortic wall portions were 0.71+/-1.27 (Photofix), 10.78+/-77.22 (Freestyle) and 28.70+/-66.53 (Prima Plus) (p <0.05 for Photofix versus Freestyle or Prima Plus).

CONCLUSION

Photo-oxidation of a porcine stentless valve prevents calcification not only in the cusps, but also in the aortic wall portion.

Involvement of protein kinase Cgamma isoform in morphine-induced reinforcing effects

The present study was designed to investigate the role of protein kinase C (PKC) isoform in the morphine-induced reinforcing effect in mice. An intracerebroventricular injection of calphostin C, a specific PKC inhibitor, produced a dose-dependent reduction in the morphine-induced place preference. The protein level of PKCgamma was significantly up-regulated in membrane preparations of the limbic forebrain obtained from the morphine-conditioned mice compared to that from the saline-conditioned mice. However, the protein levels of PKCalpha, betaI, betaII and epsilon were not affected in the same preparation. By contrast, there were no changes in the protein level of all five PKC isoforms in the lower midbrain. Furthermore, we investigated the rewarding properties of morphine in mice lacking PKCgamma gene. A significant place preference was observed following treatment with morphine in wild-type mice, whereas such an effect of morphine was not found in PKCgamma knockout mice. These findings suggest that activated PKCgamma in the limbic forebrain following the treatment with morphine may be critical for the development and/or maintenance of reinforcing effects induced by morphine in mice.

In vitro inhibitory effects of J-113397 on nociceptin/orphanin FQ-stimulated

J-113397 (1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one) is a recently developed antagonist of the opioid receptor-like 1 (ORL1) receptor. We compared the in vitro functional profile J-113397 on [35S]guanosine 5'-O-(gamma-thio)triphosphate (GTPgammaS) binding to mouse brain with that of [Phe1psi(CH2-NH)Gly2]nociceptin(1-13)NH2 and naloxone benzoylhydrazone (NalBzoH). J-113397 antagonized nociceptin/orphanin FQ-stimulated [35S]GTPgammaS binding to mouse brain with an IC50 value of 7.6 nM, but had no effect on basal [35S]GTPgammaS binding by itself. [Phe1psi(CH2-NH)Gly2]nociceptin(1-13)NH2 partially antagonized nociceptin/orphanin FQ-stimulated [35S]GTPgammaS binding but showed agonistic activity on ORL1 by itself. NalBzoH showed antagonistic activity on ORL1 receptor but had significant agonistic activity on other opioid receptors at lower doses. Schild plot analysis demonstrated competitive antagonism of J-113397 on ORL1 receptor in mouse brain. A [35S]GTPgammaS binding study using ORL1 receptor-deficient mice confirmed the selective antagonism of J-113397 on ORL1 receptor. These data indicate that J-113397 is the most potent and selective antagonist of ORL1 receptor in mouse brain that has yet been reported, and therefore will be a useful tool for characterization of ORL1 receptors in the brain.

Characteristics of patients with hypnotic-related psychiatric disorders in the nationwide mental hospital survey

We investigated the characteristics of patients with hypnotic-related psychiatric disorders. Subjects were 90 patients reported in the nationwide Mental Hospital Survey in 1998, who were divided into three groups according to their history of substances use. Group A (patients without history of any illicit substance use) was estimated to be the most common and core group with iatrogenic characteristics. Hypnotic use in Group B (patients with history of any illicit substance use) was recognized as one of behavioral disorders in the psychosocial context. Patients in Group C (patients with multiple-substance use and without history of any illicit substance use) showed the most serious disorders in the context of addiction. More specified treatment programs would be required considering patients' characteristics.

Local cellular sources of apolipoprotein E in the human retina and retinal pigmented epithelium: implications for the process of drusen formation

PURPOSE

The inheritance of specific apolipoprotein E allelles has been linked to atherosclerosis, Alzheimer disease, and, most recently, to the incidence of age-related macular degeneration. Apolipoprotein E is a common component of the extracellular plaques and deposits characteristic of these disorders, including drusen, which are a hallmark of age-related macular degeneration. Accordingly, we assessed the potential biosynthetic contribution of local ocular cell types to the apolipoprotein E found in drusen.

METHODS

We measured apolipoprotein E mRNA levels in human donor tissues using a quantitative assay of apolipoprotein E transcription, and we localized apolipoprotein E protein to specific cell types and compartments in the neural retina, retinal pigmented epithelium, and choroid using laser scanning confocal immunofluorescence microscopy.

RESULTS

Apolipoprotein E immunoreactivity is associated with photoreceptor outer segments, the retinal ganglion cell layer, the retinal pigmented epithelium basal cytoplasm and basal lamina, and with both collagenous layers of Bruch membrane. Apolipoprotein E appears to be a ubiquitous component of drusen, irrespective of clinical phenotype. It also accumulates in the cytoplasm of a subpopulation of retinal pigmented epithelial cells, many of which overlie or flank drusen. Mean levels of apolipoprotein E mRNA in the adult human retina are 45% and 150% of the levels measured in liver and adult brain, the two most abundant biosynthetic sources of apolipoprotein E. Apolipoprotein E mRNA levels are highest in the inner retina, and lowest in the outer retina where photoreceptors predominate. Significant levels of apolipoprotein E mRNA are also present in the retinal pigmented epithelium/choroid complex and in cultured human retinal pigmented epithelial cells.

CONCLUSIONS

Apolipoprotein E protein is strategically located at the same anatomic locus where drusen are situated, and the retinal pigmented epithelium is the most likely local biosynthetic source of apolipoprotein E at that location. Age-related alteration of lipoprotein biosynthesis and/or processing at the level of the retinal pigmented epithelium and/or Bruch membrane may be a significant contributing factor in drusen formation and age-related macular degeneration pathogenesis.

Calcification characteristics of porcine stented valves in a juvenile sheep model

BACKGROUND

Different antimineralization treatments of stented porcine bioprostheses were evaluated: ethanol (Epic), alpha-amino-oleic acid (AOA) (Mosaic), and sodium dodecyl sulfate (SDS) (Hancock II). A nontreated, glutaraldehyde-fixed valve (Labcor) served as control.

METHODS

For each treatment, six valves were implanted in juvenile sheep in the pulmonary position. Valves were explanted after 3 and 6 months and examined macroscopically, by roentgenogram and light and transmission electron microscopy. Calcium content (microg/mg) was determined by atomic absorption spectrometry.

RESULTS

The Labcor valves revealed small calcium deposits in the cusps, although calcium content remained low (median value 0.4+/-0.8 microg/mg). SDS did not prevent cusp calcification as assessed by histology and calcium content measurement, which was higher than in all other valves: 1.9+/-4.6 microg/mg (p < 0.05). Cusp retraction and rupture were occasionally found in the Hancock. The Mosaic and Epic valves showed no cusp calcification and had low calcium contents (0.3+/-2.4 microg/mg and 0.7+/-0.6 microg/mg, respectively). Epic showed less pannus formation, but had hematoma or iron staining in the cusps.

CONCLUSIONS

SDS is inefficient as an antimineralization treatment, in contrast to ethanol or AOA. Cusp hematoma after ethanol treatment needs further investigation.