Statins induce S1P1 receptors and enhance endothelial nitric oxide production in response to high-density lipoproteins

BACKGROUND AND PURPOSE

Sphingosine 1-phosphate (S1P) is a serum-borne naturally occurring sphingolipid, specifically enriched in high-density lipoprotein (HDL) fractions. S1P binds to G-protein-coupled S1P1 receptors to activate endothelial NO synthase (eNOS) in vascular endothelial cells. We explored whether and how statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, modulate expression of S1P1 receptors and endothelial responses for subsequent stimulation with S1P or with HDL.

EXPERIMENTAL APPROACH

Protein expression and phosphorylation and mRNA expression in cultured bovine aortic endothelial cells (BAEC) were determined using immunoblots and reverse transcription PCR analyses, respectively. NO synthesis was assessed as nitrite production.

KEY RESULTS

Stimulation of BAEC with pitavastatin or atorvastatin led to significant increases in S1P1-receptors, at levels of protein and mRNA, in a dose-dependent manner. When BAEC were treated with pitavastatin prior to stimulation with S1P or with normal human HDL, phosphorylation and activation of eNOS evoked by S1P or by HDL was enhanced. These effects of statins were counteracted by L-mevalonate and were mimicked by an inhibitor of geranylgeranyl transferase I, suggesting that inhibition of HMG-CoA reductase activity and subsequent decreases in protein geranylgeranylation may contribute to these actions of statins. Specific knock down of S1P1 receptors by small interfering RNA led to attenuation of eNOS responses to HDL.

CONCLUSIONS AND IMPLICATIONS

Statins induce S1P1 receptors and potentiate responses of endothelial cells to HDL-associated sphingolipids, identifying a novel aspect of the pleiotropic actions of statins through which they may exert NO-dependent vascular protective effects.

Genotoxic Risks to Nurses from Contamination of the Work Environment with Antineoplastic Drugs in Japan

The aims of the present study were to clarify the work environment contamination by antineoplastic drugs in a hospital ward and to assess the genotoxic risks to nurses who routinely handle antineoplastic drugs in Japan. The exposed group consisted of 19 female nurses who routinely handled antineoplastic drugs. The control group consisted of 18 female nurses who did not handle antineoplastic drugs in the same hospital as the exposed group. The genotoxicity of the 19 antineoplastic drugs used in the hospital ward and 8 wipe samples of the workbench after handling of antineoplastic drugs were measured using the umu assay. Lymphocyte DNA damage (tail length) was measured with alkaline methods of the single cell gel electrophoresis assay (comet assay). Of the 19 antineoplastic drugs, dacarbazine, bleomycin, daunorubicin, doxorubicin, pirarubicin, carboplatin, cisplatin and etoposide induced genotoxicity. Of the 8 sampling d, the umu activity of the wipe sample was positive on 3 d. Contamination of the workbench was found when the nurses handled more drugs than on other days. The medians of the tail length in the comet assay were 8.5 and 5.1 microm, respectively, for the exposed and control groups, with a significant difference (p=0.004 by Mann-Whitney's U-test). In the present study, the nurses of the exposed group were considered to have been exposed to antineoplastic drugs and lymphocyte DNA damage of the exposed group was suggested to be induced by antineoplastic drugs.

Abnormal pontine activation in pathological laughing as shown by functional magnetic resonance imaging

To explore the aetiology of pathological laughing, a 65-year-old woman with pathological laughing was examined by 3-T functional magnetic resonance imaging (fMRI) before and after treatment with drugs. Here, we report that the patient consistently showed exaggerated pontine activation during the performance of three tasks before treatment, whereas abnormal pontine activation was no longer found after successful treatment with the selective serotonin reuptake inhibitor, paroxetine. Our findings in this first fMRI study of pathological laughing suggest that serotonergic replacement decreases the aberrant activity in a circuit that involves the pons.

Preservation of C7 spinous process does not influence the long-term outcome after laminoplasty for cervical spondylotic myelopathy

Axial pain is one of the major complications after laminoplasty, and preservation of C7 spinous process during the procedure can reduce the axial pain. However, it has not been elucidated whether laminoplasty preserving the C7 spinous process can maintain neurological improvement for a long time. The purpose of our retrospective study was to investigate the long-term neurological outcome after open-door laminoplasty preserving the C7 spinous process for cervical spondylotic myelopathy (CSM). Clinical and radiological outcomes were analysed in 42 patients who underwent open-door laminoplasty preserving C7 spinous process and followed up for more than 5 years. Neurological function was evaluated by means of the Japanese Orthopaedic Association (JOA) scoring system for cervical myelopathy. Axial pain was assessed using a visual analog scale (VAS) at the last examination. Alignment and motion of the cervical spine were measured from radiographs, and magnetic resonance imaging (MRI) was used to evaluate postoperative compression at C7. The mean JOA score was 9.4 before surgery and 12.0 at the latest follow-up. The mean VAS score in 26 patients score was 9.7/100. No compression of the spinal cord was observed in any MRI at the latest follow-up. Preservation of the C7 spinous process does not influence the long-term outcome of CSM after laminoplasty. Although we did not have a comparative group, the procedure described here should be considered as the solution.

[Equipment at the special nursing homes for the elderly: a workplace survey of new nursing homes in Osaka Prefecture]

The number of those who need nursing care and the workers who provide it have been increasing year after year. In April 2000, the public nursing care insurance system was enacted by the Japanese government. After its enaction, care equipment came under scrutiny, but the situation regarding the installation of equipment is not fully understood. In order to understand the present state of care equipment in nursing facilities for the elderly, we conducted a workplace and interview survey. The surveyed facilities were 10 special nursing homes for the elderly in Osaka Prefecture which were established after April 2002. The average number of elderly residents was 79.0, the average value of degree of care was 3.52, and the average number of caregivers was 28.3 per facility. We found all facilities had installed some kinds of bathing equipment: stretcher type, 9 facilities; bath-chair type, 8 facilities. In the facilities with bath-chairs, 6 facilities had special bathtubs, and 6 facilities had general bathtubs. However, all facilities had the working principle that transfer should be done manually, and the equipment for transfer such as a lifts, a transfer and roller board were not be installed. In changing diapers, bed height adjustment was not possible. And the Japanese standard type of wheelchair has a non-detachable armrest, creating a structural barrier when transferring elderly people from a wheelchair to a toilet seat. At all facilities the basis of care was that caregivers should do it manually. In particular, all facilities had only a weak recognition of the risks of transfer. This investigation shows that facilities for the elderly should rethink elderly care based on a reduction of care load and most importantly protection of caregivers' health.

Cloning and characterization of Pseudomonas putida genes encoding the phosphate-specific transport system

The pstSCAB genes of Pseudomonas putida PRS2000, encoding the phosphate (Pi)-specific transport (Pst) system, were cloned. The pstS gene of Pseudomonas aeruginosa PAO1, of which the pstCAB genes had been cloned previously, was also cloned (Nikata, T. et al., Mol. Gen. Genet., 250, 692-698, 1996). The predicted translation products of the P. putida pstSCAB genes showed 83, 75, 78 and 88% amino acid identity with their P. aeruginosa counterparts. Two well-conserved Pho box sequences were found in the region upstream of the pstS gene (15/18 base identity with the consensus Pho box sequence) and in the intercistronic region between the pstS and pstC genes (11/18 base identity) of P. putida PRS2000. To investigate the functions of PstSCAB, the pstSC genes were inactivated by inserting a kanamycin resistance gene cassette into the chromosome of P. putida PRS2000. The resultant mutant, designated PNT1, failed to take up 32Pi even under conditions of Pi limitation. Strain PNT1 was also constitutive for alkaline phosphatase synthesis, as well as chemotaxis toward Pi, indicating that the Pst system is involved in the negative regulation of the pho regulon in P. putida. Although overexpression of the pstSCAB genes in P. putida PRS2000 resulted in decreased cell growth, this recombinant strain could remove Pi at a rate similar to that seen with the control strain.

Negative association between serum dioxin level and oxidative DNA damage markers in municipal waste incinerator workers

OBJECTIVES

To investigate the effect of dioxin on the formation of oxidative DNA damage and urinary mutagenicity, we measured the concentrations of serum dioxins and lymphocytic 8-hydroxydeoxyguanosine (8-OH-dG) in 57 male waste incinerator workers, urinary 8-OH-dG and urinary mutagenicity in 29 male waste incinerator workers.

METHODS

Information about the subjects was obtained from a questionnaire. Concentrations of polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and coplanar-polychlorinated-biphenyl (Co-PCB) in serum samples from the workers were measured with a high-resolution gas chromatograph /high-resolution mass spectrometer. Lymphocytic and urinary 8-OH-dG levels were measured with a high-performance liquid chromatography-electrochemical detector system. The urinary mutagenicity was measured with umu assay.

RESULTS

The lymphocytic 8-OH-dG level showed a negative association with the serum dioxin level (total value of TEQ-PCDD, PCDF, and Co-PCB). Urinary 8-OH-dG did not show correlation with serum dioxin level, but showed positive correlation with the smoking index.

CONCLUSIONS

With respect to the subjects' serum dioxin level, dioxin did not increase the urinary 8-OH-dG level by oxidative DNA damage, but upregulation of the primary defenses with oxidative damage and/or DNA repair system activity might have occurred.

[Load on the low back of care workers in nursing homes for the elderly]

In order to evaluate the load on the low back of care workers in nursing homes for the elderly, basic activities and working postures were analyzed for six care workers using the 30-s snap reading method. The trunk inclination angle (TIA) was also measured continuously using an inclination monitor. The analysis of basic activities showed that 22.5% and 21.1% of the workshift were spent on 'bathing and ablution' and 'meal', respectively, and 9.3%, 8.7% and 8.3% were spent on 'assistance with elimination', 'assistance with moving and repositioning' and 'exchange of bed sheet', respectively. Total of the assistance activity was 43.7% of the workshift. The analysis of working posture showed that 'standing' and 'standing bent forward' accounted for 36.1% and 29.5%, respectively, of the workshift. Total of three postures loading the low back ('standing bent forward', 'squatting', 'kneeling') accounted for 39.0%. The time spent in TIA of 20 degrees or more was 45.7%. The postures loading the low back during 'bathing and ablution', 'exchange of bed sheet' and 'assistance with elimination' account for 68.3%, 58.2% and 49.6%, respectively, which suggests that these activities load the low back of the care workers considerably.

Prevention of toxic epidermal necrolysis by regulatory T cells

To analyze immunoregulation of autoreactive T cells specific for epidermal skin antigens, we crossed transgenic mice expressing ovalbumin selectively in keratinocytes under the keratin 5 promoter (K5-mOVA) with mice expressing a K(b)-restricted OVA-specific T cell receptor transgene (OT-I). In athymic double-transgenic mice, OT-I cells developed extrathymically and, at 8-12 weeks of age, initiated severe epidermal damage mimicking toxic epidermal necrolysis (TEN). In contrast, euthymic double-transgenic mice showed thymic deletion of OT-I cells, had few of these cells in the periphery, and never developed skin changes mimicking TEN. Adoptive transfer of OT-I cells isolated from euthymic double-transgenic mice induced TEN in athymic K5-mOVA single-transgenic mice. This spontaneous disease in athymic double-transgenic mice was prevented by transferring lymph node cells from euthymic mice, but was not prevented when CD4(+) or CD25(+) cells were depleted from this population. Although purified CD4(+)CD25(+) cells scarcely prevented the skin disease induced by adoptive transfer of OT-I cells, they efficiently prevented the disease when co-transferred with CD11c(+) dendritic cells. These results suggested that thymus-derived regulatory T cells cooperate with CD11c(+) dendritic cells to prevent life-threatening skin damage such as TEN.

Effects of dioxin on metabolism of estrogens in waste incinerator workers

The authors measured the concentrations of serum dioxins and urinary estrogen metabolites in 57 male waste incinerator workers to determine whether dioxin influenced the metabolism of estrogens. Concentrations of serum dioxin levels and urinary estrogen metabolites, such as estrone, 17beta-estradiol, 2-hydroxyestrone, 2-methoxyestrone, 2-hydroxyestradiol, 2-methoxyestradiol, 4-hydroxyestrone, 4-hydroxyestradiol, 4-methoxyestradiol, 16-hydroxyestrone, and estriol from the workers were measured. An analysis of covariance showed that mean estriol concentrations, adjusted for confounding factors among 3 serum dioxin levels, indicated a progressive increase with increasing serum dioxin level: 1.30, 1.41, and 2.02 nmol/mol creatinine at < 30.3, 30.3-39.7, and > 39.7 pg toxicity equivalent quantity/g lipid, respectively (F = 3.56, p = .036). This study showed that dioxin acts to metabolize estrogens to 16-hydroxyestrogens rather than to 2- or 4-hydroxyestrogens.

Rare Helicobacter pylori infection as a factor for the very low stomach cancer incidence in Yogyakarta, Indonesia

To elucidate factors associated with the very low risk of gastric neoplasia in Yogyakarta, Indonesia, approximately 1/50 of the level in Japan, we recruited 52 male and 39 female participants from the general populace in the city of Yogyakarta in October 2003. Helicobacter pylori IgG antibodies were found in only 5% (0-13) (95% confidence interval) and 4% (0-9) for Javanese males and females, respectively, and were statistically lower than the 62% (58-65) and 57% (53-60), respectively, in Japanese. Furthermore, positive findings of pepsinogen test were only 0 and 2% (0-6) for males and females, in Yogyakarta, and were again significantly lower than the 23% (22-25) and 22% (20-23), in Japan. The very low incidence of stomach cancer in Yogyakarta may be due to a low prevalence of H. pylori infection and chronic atrophic gastritis.

Modification of cytokine milieu by A2A adenosine receptor signaling--possible application for inflammatory diseases

Pro-inflammatory cytokine TNF-alpha (TNF) production from in vitro lipopolysaccharide (LPS)-stimulated human peripheral blood CD14+ cells (PB-CD14) was inhibited by A2A adenosine receptor (AdoR) (A2AR) or beta2 adrenergic receptor (ADR) (beta2R) signaling in a concentration-dependent manner. These inhibitory effects were presumably mediated by the increase in intracellular cAMP. Furthermore A2AR agonist and beta2R agonist synergistically inhibited the TNF production of LPS-stimulated PB-CD14 cells. These results suggest that the anti-inflammatory effect of extracellular adenosine is, at least in part, due to the modification of the cytokine milieu via A2A signaling, and that the targeting of both A2AR and beta2R may have strong therapeutic potential for the inflammatory diseases.

A study on the effect of lead on event-related potentials among lead-exposed workers

OBJECTIVES

In order to clarify the effect of lead on higher cerebral functions, lead-exposed workers (Pb group) and controls were examined for event-related potentials.

SUBJECTS AND METHODS

Fourteen lead-exposed workers with a mean age of 57.1 yr (SD=4.27, range 48-64; lead concentration of whole blood ranged from 33 to 106 microg/dl with a mean of 58.6 and SD 28.6 microg/dl) and 19 age-matched control workers with a mean age of 57.3 yr (SD=4.80, range 48-65) were examined. Visual P300 was recorded by button pushing to the target image (minute checkerboard pattern, 20%), and the NO-GO potential by no button pushing to the target image (same as above, 50%).

RESULTS

Latencies of P300 in the Pb group (475+/-46.0 ms) were significantly delayed compared with those in controls (407+/-42.4 ms, p<0.01 by Student's t test). Amplitudes of the NO-GO potential in the Pb group (4.59+/-2.04 microV) significantly increased compared with those in the controls (3.18+/-1.41 microV, p<0.05).

CONCLUSION

The finding suggests that lead exposure affects high cerebral functions of cognition and attention, but is unclear in suppression of movement.

Individual trait anxiety levels characterizing the properties of zen meditation

Meditation is a specific consciousness state in which deep relaxation and increased internalized attention coexist. There have been various neurophysiological studies on meditation. However, the personal predispositions/traits that characterize the properties of meditation have not been adequately studied. We analyzed changes in neurophysiological parameters [EEG coherence and autonomic nervous activity using heart rate variability (HRV) as an index] during Zen meditation, and evaluated the results in association with trait anxiety (assessed by Spielberger's State-Trait Anxiety Inventory) in 22 healthy adults who had not previously practiced any form of meditation. During meditation, in terms of mean values in all subjects, an increase in slow alpha interhemispheric EEG coherence in the frontal region, an increase in high-frequency (HF) power (as a parasympathetic index of HRV), and a decrease in the ratio of low-frequency to HF power (as a sympathetic index of HRV) were observed. Further evaluation of these changes in individuals showed a negative correlation between the percent change (with the control condition as the baseline) in slow alpha interhemispheric coherence reflecting internalized attention and the percent change in HF reflecting relaxation. The trait anxiety score was negatively correlated with the percent change in slow alpha interhemispheric coherence in the frontal region and was positively correlated with the percent change in HF. These results suggest that lower trait anxiety more readily induces meditation with a predominance of internalized attention, while higher trait anxiety more readily induces meditation with a predominance of relaxation.

Inhibition of nuclear factor kappa B activation and inducible nitric oxide synthase transcription by prolonged exposure to high glucose in the human keratinocyte cell line HaCaT

BACKGROUND

In human skin, inducible nitric oxide synthase (iNOS) appears to be a key enzyme during wound healing and has roles in protection from infection. We speculated that diabetic skin complications such as delayed wound healing and skin infection were due to iNOS activity altered by high glucose in skin keratinocytes.

OBJECTIVES

The purpose of this study was to see how high levels of glucose affect iNOS activity in the human keratinocyte cell line (HaCaT).

METHODS

HaCaT cells were exposed to high glucose for 1 day or 10 days. We measured nitric oxide (NO) end product nitrite in the culture medium using the Griess reagent, and intracellular tetrahydrobiopterin (BH(4), a cofactor of NOS) content by using high-performance liquid chromatography, analysed the expression level of iNOS mRNA by the reverse transcriptase-polymerase chain reaction method and evaluated the DNA binding activity of nuclear factor kappa B (NF-kappaB) by enzyme-immunoassay.

RESULTS

Short-term exposure (1 day) to a high level of glucose increased BH(4) and iNOS activity at the post-translational level. However, long-term exposure (10 days) to high glucose downregulates NF-kappaB binding activity and inhibits iNOS transcription and its activity.

CONCLUSIONS

Pretreatment with high glucose for 10 days down-regulated NF-kappaB activity and inhibited iNOS transcription and NO production, implying the involvement of a deficiency in NO synthesis in both skin infection and impaired wound healing in diabetic patients.

Neural substrates participating in acquisition of facial familiarity: an fMRI study

The amygdala is related to recognition of faces and emotions, and functional magnetic resonance imaging (fMRI) studies have reported that the amygdala is habituated over time with repetition of facial stimuli. When subjects are presented repeatedly with unfamiliar faces, they come to gradually recognize the unfamiliar faces as familiar. To investigate the brain areas participating in the acquisition of familiarity to repeatedly presented unfamiliar faces, we conducted an fMRI study in 16 healthy subjects. During the task periods, the subjects were instructed to see presented unfamiliar faces repeatedly and to judge whether the face was male or female or whether the face had emotional valences. The experiment consisted of nine sessions. To clarify the brain areas that showed increasing or decreasing activation as the experimental session proceeded, we analyzed the fMRI data using specified linear covariates in the face recognition task from the first session to the ninth session. Imaging data were investigated on a voxel-by-voxel basis for single-group analysis according to the random effect model using Statistical Parametric Mapping. The bilateral posterior cingulate cortices showed significant increases in activity as the experimental sessions proceeded, while the activation in the right amygdala and the left medial fusiform gyrus decreased. Thus, the posterior cingulate cortex may play an important role in the acquisition of facial familiarity.

[Relationships between dioxin concentrations in deposited dust and those in serum of workers at municipal waste incineration plants]

Relationships between concentrations of polychlorodibenzo-p-dioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in deposited dust and those in the serum of incinerator workers were examined at 13 municipal incineration plants. The following results were found. 1) Dust analysis showed that dominant constituents were octachlorodibenzo-p-dioxin (OCDD) and 1, 2, 3, 4, 6, 7, 8-heptachlorodibenzo-p-dioxin (HpCDD) among PCDDs, and 1, 2, 3, 4, 6, 7, 8-heptachlorodibenzofuran (HpCDF) and octachlorodibenzofuran (OCDF) among PCDFs. The toxicity equivalents (TEQs) of total PCDDs and PCDFs in the deposited dust were 0.54 to 33 ngTEQ/g, which were about 1,000 to 10,000 times as high as those in general soil. 2) The mean of serum TEQ of PCDDs, that of PCDFs and that of total PCDDs and PCDFs in the incinerator workers were 16, 12 and 28 pg TEQ/g lipid, respectively, for all the incinerator workers. Concentrations of hexachlorodibenzofurans (HxCDFs) and HpCDFs in the serum were significantly higher in the incinerator workers than the general population, which suggests that these workers had inhaled these chemicals during their work. 3) The concentration of 1, 2, 3, 4, 6, 7, 8-HpCDF and the TEQ value of PCDFs and in the serum were positively correlated with those in dust except for three plants where large-scale remodeling of the equipment was conducted within the past seven years. Consequently, deposited dust analysis may be useful for judging whether health examination containing blood dioxin measurement is necessary or not.

Vesiculobullous dermatomyositis with panniculitis without muscle disease

Vesicles and bullae formation is rare in dermatomyositis. We describe a 60-year-old woman who presented with vesiculobullous dermatomyositis with panniculitis and no muscle disease.

Abnormal nocturnal blood pressure fall in senile-onset depression with subcortical silent cerebral infarction

Recent studies have shown that the complication rate of silent cerebral infarction (SCI) in patients with geriatric depression increases with the age at the onset of depression. This study investigated the cardiovascular factors involved in the development of SCI in geriatric depression. Thirty-six patients with geriatric depression were classified according to the age at onset into 16 who developed depression at the age of <50 years (early-onset group) and 20 who developed depression at the age of > or =50 years (late-onset group). The incidence of SCI assessed by subcortical hyperintensity on MRI images, office blood pressure (BP), nocturnal systolic BP fall pattern examined by 24-hour ambulatory BP monitoring, and the severity of carotid atherosclerosis examined by B-mode ultrasonography were compared between the two groups. Furthermore, the association between the presence or absence of SCI and the nocturnal systolic BP fall pattern or the severity of carotid atherosclerosis was evaluated. The SCI complication rate was higher in the late-onset group (55.0%) than in the early-onset group (18.7%). The office BP and mean 24-hour BP did not differ significantly between the two groups. Abnormal nocturnal systolic BP fall patterns were observed in 85.0% (nondipper type showing a fall of <10% in 60.0%, extreme-dipper type showing a fall of > or =20% in 25.0%) in the late-onset group, which was significantly higher than the incidence in the early-onset group (18.7%). No significant difference was observed in any parameter of carotid atherosclerosis between the two groups. In addition, the patients with SCI more frequently showed abnormal nocturnal systolic BP fall patterns than those without SCI. These results suggest that abnormal nocturnal BP fall patterns appear to be involved in the development of SCI in senile-onset depression.

Induction of T-cell-mediated skin disease specific for antigen transgenically expressed in keratinocytes

Transgenic mice were generated to establish an animal model for T-cell-mediated autoimmune skin disease. A membrane-bound form of OVA (mOVA) was specifically expressed under the control of the keratin 5 (K5) promoter in the epidermal and hair follicular keratinocytes of mice. Syngeneic, wild-type mice rejected the skin grafts of K5-mOVA mice with the generation of OVA-specific CTL. To study the CTL response against K5-mOVA skin, we used OT-I transgenic mice, which produce K(b)-restricted, OVA-specific CD8+ T cells. Accelerated rejection of K5-mOVA skin was demonstrated when transplanted onto OT-I mice. Furthermore, OT-I cells, when adoptively transferred into K5-mOVA mice, underwent activation and vigorous proliferation in the skin-draining lymph nodes. A bone-marrow-reconstitution assay demonstrated that K(b) presentation by bone-marrow-derived cells, but not epithelial cells, was required for this response, indicating that cross-priming was the basis for immunity in this model. Finally, transferred OT-I cells, activated by cross-priming, targeted the skin of K5-mOVA mice, resulting in development of skin lesions that were reminiscent of toxic epidermal necrolysis. We conclude that our system provides a useful model for autoimmune skin diseases and will aid understanding of the pathomechanism of drug eruption, viral exanthema, and graft-versus-host disease.

Nitric oxide synthase inhibition by N(G)-nitro-L-arginine methyl ester retards vascular sprouting in angiogenesis

The present study was designed to evaluate the role of nitric oxide (NO) for angiogenesis. Angiogenesis was elicited upon mouse cornea by chemical cautery with silver nitrate. Angiogenic activity was evaluated by measuring the length of vascular sprout with or without administration of NO synthase (NOS) inhibitor, N((G))-nitro-L-arginine-methyl ester (L-NAME). In the pericorneal plexus, a circulatory loop situated in the same topological situation for all individuals was selected to observe vascular sprouting. At 72 h after cauterization, the length of the longest vascular sprout was measured using the perfused whole-mount cornea. The length of nontreated mice (83 +/- 83 microm) was significantly longer than that of L-NAME treated mice (33 +/- 24.6 microm). To address the possible contribution of production of vascular endothelial growth factor (VEGF) and NO, we measured mRNAs of VEGF and inducible NOS. The mRNA level of VEGF increased to 170% of the nontreated level at 12 h after cauterization and returned to the nontreated level by 24 h after cauterization. mRNA of inducible NOS remained elevated 24 h after cauterization. These results suggest that the response of preexisting vessels to angiogenic stimulus via NO is of importance in the process of angiogenesis, i.e., vascular sprouting is promoted by NO production. This might be attributable to enhancement of an increase in vascular permeability and /or vasodilation via NO.

Inefficient response of T lymphocytes to glycosylphosphatidylinositol anchor-negative cells: implications for paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematopoietic stem cell disorder in which clonal cells defective in glycosylphosphatidylinositol (GPI) biosynthesis are expanded, leading to complement-mediated hemolysis. PNH is often associated with bone marrow suppressive conditions, such as aplastic anemia. One hypothetical mechanism for the clonal expansion of GPI(-) cells in PNH is that the mutant cells escape attack by autoreactive cytotoxic cells that are thought to be responsible for aplastic anemia. Here we studied 2 model systems. First, we made pairs of GPI(+) and GPI(-) EL4 cells that expressed major histocompatibility complex (MHC) class II molecules and various types of ovalbumin. When the GPI-anchored form of ovalbumin was expressed on GPI(+) and GPI(-) cells, only the GPI(+) cells presented ovalbumin to ovalbumin-specific CD4(+) T cells, indicating that if a putative autoantigen recognized by cytotoxic cells is a GPI-anchored protein, GPI(-) cells are less sensitive to cytotoxic cells. Second, antigen-specific as well as alloreactive CD4(+) T cells responded less efficiently to GPI(-) than GPI(+) cells in proliferation assays. In vivo, when GPI(-) and GPI(+) fetal liver cells, and CD4(+) T cells alloreactive to them, were cotransplanted into irradiated hosts, the contribution of GPI(-) cells in peripheral blood cells was significantly higher than that of GPI(+) cells. The results obtained with the second model suggest that certain GPI-anchored protein on target cells is important for recognition by T cells. These results provide the first experimental evidence for the hypothesis that GPI(-) cells escape from immunologic attack.

Differential amygdala response during facial recognition in patients with schizophrenia: an fMRI study

Human lesion or neuroimaging studies suggest that amygdala is involved in facial emotion recognition. Although impairments in recognition of facial and/or emotional expression have been reported in schizophrenia, there are few neuroimaging studies that have examined differential brain activation during facial recognition between patients with schizophrenia and normal controls. To investigate amygdala responses during facial recognition in schizophrenia, we conducted a functional magnetic resonance imaging (fMRI) study with 12 right-handed medicated patients with schizophrenia and 12 age- and sex-matched healthy controls. The experiment task was a type of emotional intensity judgment task. During the task period, subjects were asked to view happy (or angry/disgusting/sad) and neutral faces simultaneously presented every 3 s and to judge which face was more emotional (positive or negative face discrimination). Imaging data were investigated in voxel-by-voxel basis for single-group analysis and for between-group analysis according to the random effect model using Statistical Parametric Mapping (SPM). No significant difference in task accuracy was found between the schizophrenic and control groups. Positive face discrimination activated the bilateral amygdalae of both controls and schizophrenics, with more prominent activation of the right amygdala shown in the schizophrenic group. Negative face discrimination activated the bilateral amygdalae in the schizophrenic group whereas the right amygdala alone in the control group, although no significant group difference was found. Exaggerated amygdala activation during emotional intensity judgment found in the schizophrenic patients may reflect impaired gating of sensory input containing emotion.

PDX-1 induces differentiation of intestinal epithelioid IEC-6 into insulin-producing cells

A homeodomain containing transcription factor PDX-1 can induce beta-cell-specific gene expressions in some non-beta-cells and may therefore be useful for future diabetes gene/cell therapy. Among the potential target organs or tissues for transcription factor-mediated induction of beta-cell-like differentiation are the intestinal epithelial cells. They have certain merits over other tissues and organs in terms of accessibility for gene delivery and of similarity in developmental background to the pancreatic primordium. In this study, we used an intestinal epithelium-derived cell line, IEC-6 cells, and investigated the possible effects of PDX-1 expression in those cells. By exogenous expression of the PDX-1 gene, IEC-6 cells started expressing multiple beta-cell-specific genes such as amylin, glucokinase, and Nkx6.1, which were not found in the original IEC-6 cells. Insulin gene expression, which was missing initially even in the PDX-1-transfected IEC-6 cells, became detectable when the cells were transplanted under the renal capsule of a rat. When the PDX-1(+) IEC-6 cells were kept in vitro, treatment with betacellulin could also confer insulin gene expression to them. Although insulin secretory granules became visible by electron microscopy, they were secreted regardless of glucose concentration. The in vivo or in vitro inductions of the insulin gene expression were not observed in the PDX-1(-) IEC-6 cells. Thus, our present observations demonstrate the potency of intestinal epithelial cells as a tool for diabetes gene/cell therapy and provide further support for the potency of PDX-1 in driving beta-cell-like differentiation in non-beta-cells.