Expression levels of Rab2, a G protein, and Bag-1, a Bcl-2 binding protein are controlled by withdrawal of nicotine from cultured pheochromocytoma PC12 cells

We previously reported that nicotine withdrawal up-regulates transcription of some immediately early genes (IEGs), c-fos (Ichino et al., 1999) and egr1, nur77 (Ichino et al., 2002) in cultures of pheochromocytoma PC12 cells, which are of neuronal lineage. In the present study we aimed at further elucidating the effects of nicotine withdrawal on the expression of the genes downstream of IEGs. We examined the changes in the protein levels of 2 GTP-binding proteins, Rab2 (Ras-related protein) and Rac1. PC12 cells were cultured in the presence of nicotine for 24 hours, and then the nicotine was removed from the medium. The protein level of Rab2 was low in the presence of nicotine, but was rapidly increased after nicotine withdrawal. In contrast, that of Rac1 did not change after the withdrawal. Considering the neuroprotective effect of nicotine, we also examined the level of Bag-1 protein, which is a binding protein for Bcl-2, an anti-apoptotic factor, and found a slight increase in the gene expression of Bag-1 following nicotine withdrawal. Among 56-kDa, 50-kDa, and 36-kDa protein components of the Bag-1 protein complex, the levels of 56-kDa and 50-kDa proteins were not changed by the addition or withdrawal of nicotine; but the level of the 36-kDa protein, which had been increased in the presence of nicotine, was markedly decreased after nicotine withdrawal. The present results suggest that such changes may also occur in individuals during abstaining from smoking and be related to the withdrawal symptoms experienced after smokers stop smoking.

Japanese SCA families with an unusual phenotype linked to a locus overlapping with SCA15 locus

The authors identified two Japanese spinocerebellar ataxia (SCA) families characterized by postural and action tremor and a very slow progression rate. A genome-wide linkage analysis revealed linkage to chromosome 3p26.1-25.3 with the highest multipoint lod score at D3S3728 (Zmax = 3.31 at theta = 0.00). The candidate region was 14.7 cM flanked by D3S1620 and D3S3691, which was partly overlapping with the locus of SCA15 characterized by pure cerebellar ataxia. Despite the difference in phenotypes, there remains a possibility that the causative gene for these Japanese SCA is allelic to SCA15.

Human cannabinoid receptor 1: 5' exons, candidate regulatory regions, polymorphisms, haplotypes and association with polysubstance abuse

A number of lines of evidence make the gene that encodes the G-protein-coupled CB1/Cnr1 receptor a strong candidate to harbor variants that might contribute to individual differences in human addiction vulnerability. The CB1/Cnr1 receptor is the major brain site at which cannabinoid marijuana constituents are psychoactive as well as the principal brain receptor for endogenous anandamide ligands. It is densely expressed in brain circuits likely to be important for both the reward and mnemonic processes important for addiction. Altered drug effects in CB1/Cnr1 knockout mice and initial association studies also make variants at the CB1/Cnr1 locus candidates for roles in human vulnerabilities to addictions. However, many features of this gene's structure, regulation and variation remain poorly defined. This poor definition has limited the ability of previous association studies to adequately sample variation at this locus. We now report improved definition of the human CB1/Cnr1 locus and its variants. Novel exons 1-3, splice variant and candidate promoter region sequences add to the richness of the CB1/Cnr1 locus. Candidate promoter region sequences confer reporter gene expression in cells that express CB1/Cnr1. Common polymorphisms reveal patterns of linkage disequilibrium in European- and in African-American individuals. A 5' CB1/Cnr1 "TAG" haplotype displays significant allelic frequency differences between substance abusers and controls in European-American, African-American and Japanese samples. Post-mortem brain samples of heterozygous individuals contain less mRNA transcribed from the TAG alleles than from other CB1/Cnr1 haplotypes. CB1/ Cnr1 genomic variation thus appears to play roles in human addiction vulnerability.

[A case of cystic cavernous angioma accompanied by a fluid-fluid level on magnetic resonance imaging]

We describe the case of a patient with cavernous angioma (CA). A 44-year-old woman complained of numbness on the left side of the body as an initial symptom of the disease. The initial magnetic resonance (MR) imaging revealed a cystic mass with a fluid-fluid level without perifocal edema in the right thalamus on the T 2-weighted image (T 2WI) and T2*-weighted image (T2*WI). Her symptoms were self-controllable; therefore we decided to observe her natural course only with serial MR imaging. The cystic mass was not enhanced by gadolinium on T1-weighted images, although, we suspected the tumor was complicated by vascular malformation. Therefore, we performed cranial angiography to eliminate the possibility of bleeding from the vascular malformation. Angiography did not demonstrate tumor staining nor vascular malformation. Longitudinally, the tumor demonstrated mosaic signal intensities on each sequence with perifocal edema. Moreover, the tumor exhibited hypointensities on T2* WIs without perifocal edema. The natural history of the tumor on MR imaging exhibited a typical case of CA. Some previous reports described cystic CA with perifocal edema and vascular malformation. In our present case, we clinically diagnosed CA on the basis of the final MR imaging together with previous reports. An intra-axial fluid-fluid level is a very rare finding of MR imaging. Here, we report the case of a patient with cystic CA accompanied by a fluid-fluid level. This finding is not a pathognomonic sign of CA; although, we consider that it is very important to follow up carefully the natural history of such cases.

[Two cases of generalized tetanus presenting with dysphagia as an initial symptom]

We describe two patients with generalized tetanus, a 60-year-old man and a 76-year-old woman, presenting with dysphagia as an initial symptom of the disease. Eighty percent of patients with generalized tetanus manifest dysphagia on admission to a hospital. However, dysphagia is rare as an initial symptom. Both our patients had dysphagia as their initial symptom, followed by neck stiffness and trismus. We made a diagnosis of generalized tetanus based on these neurological findings in the absence of an apparent episode of trauma. After the administration of tetanus immunoglobulin on admission, they recovered without exhibiting generalized convulsion, autonomic storm, or any other serious complications. The vaccination of tetanus toxoid cannot maintain sufficient antibody titers more than ten years. Therefore, elderly people are considered susceptible to tetanus. We suggest that tetanus should be considered in the differential diagnosis of dysphagia particularly in elderly patients. We also suggest that treatment of tetanus should be initiated immediately, because tetanus still has a high mortality rate at present.

CSF hypocretin levels in Guillain-Barre syndrome and other inflammatory neuropathies

CSF hypocretin-1 was measured in 28 Guillain-Barré syndrome (GBS), 12 Miller-Fisher syndrome, 12 chronic inflammatory demyelinating polyneuropathy (CIDP), and 48 control subjects. Seven GBS subjects had undetectably low hypocretin-1 levels (<100 pg/mL). Hypocretin-1 levels were moderately reduced in an additional 11 GBS, 5 Miller-Fisher syndrome, and 1 CIDP subject. Low levels in GBS occurred early in the disease and were associated with upper CNS level abnormalities.

Gradient liquid chromatography of leucine-enkephalin peptide and its metabolites with electrochemical detection using highly boron-doped diamond electrode

Boron-doped diamond thin film (BDD) electrodes have been used to study the oxidation reactions and to detect leucine-enkephalinamide (LEA) and its metabolites, tyrosine (T), tyrosyl-alanine (TA), tyrosyl-alanine-glycine (TAG) and leucine-enkephalin (LE) using cyclic voltammetry (CV), flow-injection analysis (FIA), and gradient liquid chromatography (LC) with amperometric detection. At diamond electrodes, well-defined and highly reproducible cyclic voltammograms were obtained with signal-to-background (S/B) ratios 5-10 times higher than those observed for glassy carbon (GC) electrodes. The analytical peaks of LC for LEA and its metabolites were well resolved. No deactivation of BDD electrodes was found after several experiments with standard as well as plasma samples, indicating high stability of the electrode. Calibration curves were linear over a wide range from 0.06 to 30 microM with regression coefficients of 0.999 for all compounds. The limits of detection obtained based on a signal-to-noise ratio of 3:1 were 3, 2.2, 2.7, 20 and 11 nM for T, TA, TAG, LE and LEA, respectively. These values were at least one order lower than those obtained at GC electrodes, which has given limits of detection of 22.88, 20.64, 89.57, 116.04 and 75.67 for T, TA, TAG, LE and LEA, respectively. Application of this method to real samples was demonstrated and validated using rabbit serum samples. This work shows the promising use of conducting diamond as an amperometric detector in gradient LC, especially for the analysis of enkephalinamide and its metabolites.

Association between serotonin 4 receptor gene polymorphisms and bipolar disorder in Japanese case-control samples and the NIMH Genetics Initiative Bipolar Pedigrees

Possible irregularities in serotonergic neurotransmission have been suggested as causes of a variety of neuropsychiatric diseases. We performed mutation and association analyses of the HTR4 gene, on 5q32, encoding the serotonin 4 receptor in mood disorders and schizophrenia. Mutation analysis was performed on the HTR4 exons and exon/intron boundaries in 48 Japanese patients with mood disorders and 48 patients with schizophrenia. Eight polymorphisms and four rare variants were identified. Of these, four polymorphisms at or in close proximity to exon d, g.83097C/T (HTR4-SVR (splice variant region) SNP1), g.83159G/A (HTR4-SVRSNP2), g.83164 (T)9-10 (HTR4-SVRSNP3), and g.83198A/G (HTR4-SVRSNP4), showed significant association with bipolar disorder with odds ratios of 1.5 to 2. These polymorphisms were in linkage disequilibrium, and only three common haplotypes were observed. One of the haplotypes showed significant association with bipolar disorder (P = 0.002). The genotypic and haplotypic associations with bipolar disorder were confirmed by transmission disequilibrium test in the NIMH Genetics Initiative Bipolar Pedigrees with ratios of transmitted to not transmitted alleles of 1.5 to 2.0 (P = 0.01). The same haplotype that showed association with bipolar disorder was suggested to be associated with schizophrenia in the case-control analysis (P = 0.003) but was not confirmed when Japanese schizophrenia families were tested. The polymorphisms associated with mood disorder were located within the region that encodes the divergent C-terminal tails of the 5-HT(4) receptor. These findings suggest that genomic variations in the HTR4 gene may confer susceptibility to mood disorder.

[Eczematous reactions after intravenous immunoglobulin therapy in two patients with Guillain-Barré syndrome and a patient with Miller Fisher syndrome]

The use of intravenous immunoglobulin (IVIG) has become an accepted treatment for patients with Guillain-Barré syndrome. Few patients develop adverse reactions to IVIG such as flushing, urticaria, eczema, chest tightness, wheezing, diaphoresis and hypotension. We report three patients who each received a five day course of IVIG at the standard dose of 0.4 g/kg/day. Two patients had Guillain-Barré syndrome, and the other had Miller Fisher syndrome. All developed eczematous reactions after 4 days from the start day of therapy to 5 days from the last day of therapy. One patient with GBS had widespread eczematous eruption with severe pompholyx lesions on the palms, fingers and soles, and spread over a period of 2 to 3 weeks to become generalized. That persisted for 4 weeks but gradually settled with desquamation by the use of topical steroids. None of our patients subsequently developed long-term or chronic eczema after the resolution of the initial cutaneous reaction. Eczematous reactions of our patients were similar to those reported in the literature and clinically typical as pompholyx. Although pompholyx has been recognized as a clinical entity, its cause remains obscure. Cutaneous reactions after IVIG infusion are recognized to be rare, but actually they may occur more frequently than our recognition, and its knowledge is essential to make the right clinical decision.

[Consciousness disturbance caused by iodoform absorption in a patient with decubitus ulcer topically treated with iodoform-gauze]

A 76-year-old man with supranuclear palsy, developed consciousness disturbance followed by the treatment of decubitus ulcer in the sacral region using iodoform-gauze. He was semicoma and tachycardia. His pupils were miotic and light reflexes were absent. EEG demonstrated diffuse and random slow activities. Plasma concentration of free iodine was high (151 micrograms/dl), but the other laboratory findings including thyroid functions were normal. He was diagnosed as suffering from iodoform poisoning. The symptoms and laboratory abnormalities of the patient recovered soon after the removal of iodoform-gauze. Although iodoform has been widely used for the treatment of wounds, there are few case reports of its side effects, such as consciousness disturbance, delirium, headache and tachycardia.

Membrane potential and bicarbonate secretion in isolated interlobular ducts from guinea-pig pancreas

The interlobular duct cells of the guinea-pig pancreas secrete HCO(3)(-) across their luminal membrane into a HCO(3)(-)-rich (125 mM) luminal fluid against a sixfold concentration gradient. Since HCO(3)(-) transport cannot be achieved by luminal Cl-/HCO(3)(-) exchange under these conditions, we have investigated the possibility that it is mediated by an anion conductance. To determine whether the electrochemical potential gradient across the luminal membrane would favor HCO(3)(-) efflux, we have measured the intracellular potential (V(m)) in microperfused, interlobular duct segments under various physiological conditions. When the lumen was perfused with a 124 mM Cl- -25 mM HCO(3)(-) solution, a condition similar to the basal state, the resting potential was approximately -60 mV. Stimulation with dbcAMP or secretin caused a transient hyperpolarization (approximately 5 mV) due to activation of electrogenic Na+-HCO(3)(-) cotransport at the basolateral membrane. This was followed by depolarization to a steady-state value of approximately -50 mV as a result of anion efflux across the luminal membrane. Raising the luminal HCO(3)(-) concentration to 125 mM caused a hyperpolarization (approximately 10 mV) in both stimulated and unstimulated ducts. These results can be explained by a model in which the depolarizing effect of Cl- efflux across the luminal membrane is minimized by the depletion of intracellular Cl- and offset by the hyperpolarizing effects of Na+-HCO(3)(-) cotransport at the basolateral membrane. The net effect is a luminally directed electrochemical potential gradient for HCO(3)(-) that is sustained during maximal stimulation. Our calculations indicate that the electrodiffusive efflux of HCO(3)(-) to the lumen via CFTR, driven by this gradient, would be sufficient to fully account for the observed secretory flux of HCO(3)(-).

Increase of transcriptional levels of egr-1 and nur77 genes due to both nicotine treatment and withdrawal in pheochromocytoma cells

The influence of nicotine on the expression of egr-1 and nur77 genes by nicotine treatment and withdrawal was assessed using PC12 cells. Nicotine treatment significantly increased the amount of mRNA for egr-1 and nur77 genes at 0.5 h post-nicotine treatment in the PC12 cells. In addition, nicotine withdrawal also elevated transcriptional levels of egr-1 and nur77 genes in Northern blot analyses. Nicotine treatment (200 microM) was also found to significantly increase expressional levels of Egr-1 and Nur77 proteins at 0.5 h post-nicotine treatment. In contrast, Egr-1 and Nur77 protein levels were dramatically decreased by nicotine withdrawal. These results suggest that expressional levels of Egr-1 and Nur77 proteins in neural cells may affect the transcriptional activity of late-response genes after nicotine withdrawal.

Hypocretin-1 (orexin-A) concentrations in cerebrospinal fluid are low in patients with Guillain-Barré syndrome

It is reported that cerebrospinal fluid (CSF) hypocretin-1 (orexin-A) concentrations in patients with narcolepsy are significantly low. Human narcolepsy is also known to be closely associated with a specific human histocompatibility leukocyte antigen (HLA), suggesting that autoimmunity is involved in the pathophysiology of the disease. Thus, it is important to know whether hypocretin changes are found in definite neuroimmunological diseases such as multiple sclerosis and Guillain-Barré syndrome (GBS). The results of the present study indicate that some patients with GBS have lower levels of CSF hypocretin-1.

Hypocretin-1 (orexin-A) levels in human lumbar CSF in different age groups: infants to elderly persons

STUDY OBJECTIVES

Recent CSF and postmortem brain hypocretin measurements in human narcolepsy suggest that hypocretin deficiency is involved in the pathophysiology of the disease. In this study, we measured CSF hypocretin-1 levels in various age ranges from infants to elder people to investigate the age-dependent change of hypocretin concentrations.

DESIGN

CSF hypocretin levels were compared by age groups and gender. ANOVA was used to examine the influences of these two parameters on CSF hypocretin levels.

SETTING

University-based sleep and biology laboratory.

PATIENTS OR PARTICIPANTS

Two hundred seventy two patients were included in this study, with 157 males and 115 females (0-79 years old).

INTERVENTIONS

CSF samples were obtained by lumber punctures with informed consents.

MEASUREMENTS AND RESULTS

Hypocretin-1 levels are not different in respect to gender or age, although our samples constitute a heterogeneous group with various disease conditions. CSF hypocretin-1 levels in infants under 4 months are similar to those in adults.

CONCLUSIONS

Early maturation of hypocretin transmission is suggested. No age- or gender-dependent changes in CSF hypocretin is observed.

Impaired blood rheology by remnant-like lipoprotein particles: studies in patients with fatty liver disease

Fatty liver disease (FLD) characterised by a high plasma levels of lipoproteins and remnant-like lipoproteins (RLP) is a risk factor for impaired microvascular blood flow, endothelial cell dysfunction and atherosclerosis. Using an immunoseparation technique with a gel mixture containing human monoclonal antibodies to apo A-I and apo B-100, we separated and measured RLP cholesterol (RLP-C) levels which reflect RLP in patients with FLD (n=20). Whole blood transit time (TT) was determined by a microchannel method (MC-FAN) which allows blood flow to be viewed via a microscope connected to an image display unit. RLP-C levels were higher (P<0.01) in FLD, 15.6 +/- 1.0 mg/dl compared with 4.8 +/- 0.5 mg/dl for controls (n=20). Similarly, TT was longer (P<0.01) in FLD, 284.5 +/- 26.1 sec/100 microl compared with 82.8 +/- 1.0 sec/100 microl for controls. Since the liver is a major site for RLP formation and degradation, it is affected to a greater extent in patients with FLD. It is likely that high levels of RLP can impair microvascular perfusion in the liver tissue and contribute to the development and progression of FLD.

Chloride transport in microperfused interlobular ducts isolated from guinea-pig pancreas

Isolated interlobular ducts from the guinea-pig pancreas secrete a HCO3--rich fluid in response to secretin. To determine the role of Cl- transporters in this process, intracellular Cl- concentration ([Cl-]i) was measured in ducts loaded with the Cl--sensitive fluoroprobe, 6-methoxy-N-ethylquinolinium chloride (MEQ). [Cl-]i decreased when the luminal Cl- concentration was reduced. This effect was stimulated by forskolin, was not dependent on HCO3- and was not inhibited by application of the anion channel/transporter inhibitor H2DIDS to the luminal membrane. It is therefore attributed to a cAMP-stimulated Cl- conductance, probably the cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channel. [Cl-]i also decreased when the basolateral Cl- concentration was reduced. This effect was not stimulated by forskolin, was largely dependent on HCO3- and was inhibited by basolateral H2DIDS. It is therefore mediated mainly by Cl-/HCO3- exchange. With high Cl- and low HCO3- concentrations in the lumen, steady-state [Cl-]i was 25-35 mM in unstimulated cells. Stimulation with forskolin caused [Cl-]i to increase by approximately 4 mM due to activation of the luminal anion exchanger. With low Cl- and high HCO3- concentrations in the lumen to simulate physiological conditions, steady-state [Cl-]i was 10-15 mM in unstimulated cells. Upon stimulation with forskolin, [Cl-]i fell to approximately 7 mM due to increased Cl- efflux via the luminal conductance. We conclude that, during stimulation under physiological conditions, [Cl-]i decreases to very low levels in guinea-pig pancreatic duct cells, largely as a result of the limited capacity of the basolateral transporters for Cl- uptake. The resulting lack of competition from intracellular Cl- may therefore favour HCO3- secretion via anion conductances in the luminal membrane, possibly CFTR.

Association analysis of the pituitary adenyl cyclase activating peptide gene (PACAP) on chromosome 18p11 with schizophrenia and bipolar disorders

In neurons, pituitary adenyl cyclase activating peptide (PACAP) stimulates signaling cascades, involving cAMP and calcium. PACAP appears to play a role in up-regulation of tyrosine hydroxylase and dopamine beta-hydroxylase via protein kinase C and/or protein kinase A. Furthermore, the PACAP gene (ADCYAP1) is located in chromosome 18p11, where linkage of bipolar disorders and schizophrenia has been reported. In this study, we scanned the coding region of the PACAP gene for mutations in 24 Japanese patients with schizophrenia and 24 Japanese patients with bipolar disorders. No variant in the coding region was found. One polymorphism, INV3-37A/T, in the third intron was detected. Case-control comparisons revealed no significant association between this polymorphism and schizophrenia or bipolar disorders. This study did not provide evidence for the contribution of the PACAP gene to the etiology of schizophrenia or bipolar disorders in the Japanese population.