Heat shock protein 70 expression increased in rabbit müller cells in the ischemia-reperfusion model

Heat shock protein 70 (HSP70) expression in the rabbit retina was evaluated in the ischemia-reperfusion model. Ischemia was induced by increasing the pressure in the anterior chamber, and the retinas were collected 1 or 12 h after reperfusion. HSP70 expression was examined by Western blot, confocal laser scanning microscopy and immunoelectron microscopy. Western blot showed that HSP70 was significantly increased in the retina 12 h after reperfusion, compared with normal control or 1 h after reperfusion. Confocal microscopy demonstrated that HSP70 was constitutive in Müller cells and that its expression was increased 12 h after reperfusion. Electron microscopy showed that glycogen-like granules were significantly decreased with prominent endoplasmic reticulum 1 h after reperfusion. Twelve hours after reperfusion, however, the density of glycogen-like granules was restored, and immunoelectron microscopy indicated that HSP70 was associated with the organelles of the Müller cells. Taken together, these data suggest that HSP70 in Müller cells plays a role in accommodation to stress.

[Compounds modulating parathyroid hormone (PTH) secretion]

The control of parathyroid hormone (PTH) secretion is strictly regulated by the parathyroid Ca receptor (CaR). Calcimimetics and calcilytics selectively act on the parathyroid CaR to inhibit and enhance PTH secretion, respectively. According to the recent pharmacological two-state model, calcimimetics act on the CaR as allosteric agonists to stabilize an active conformation of CaR. Conversely, calcilytics act on the CaR as allosteric inverse agonists to stabilize an inactive conformation of CaR. These compounds that can alter circulating levels of PTH and bone turnover might provide novel treatments for adynamic bone disease in patients with chronic renal failure.

Crucial amino acid residues of mouse CD1d for glycolipid ligand presentation to V(alpha)14 NKT cells

A novel lymphocyte, NKT cells bearing an invariant V(alpha)14 antigen receptor, specifically recognizes alpha-galactosylceramide (alpha-GalCer) exclusively presented by mouse CD1d (mCD1d). However, the precise molecular interaction remains unclear. For the basis of functional analyses, a docking model of alpha-GalCer with the crystal structure of mCD1d was constructed. Possible residues involved in the alpha-GalCer--mCD1d interaction were found to be Arg79, Glu83 and Asp80 for carbohydrate recognition, and Asp153 for interaction with the amide group on the fatty acyl chain. The alpha-GalCer-presenting ability of various transfectants expressing mutant mCD1d was completely abrogated if a single amino acid mutation was induced at positions 79, 80, 83 or 153, suggesting that the polar amino acids above the F' pocket are crucial for alpha-GalCer presentation to activate V(alpha)14 NKT cells. The possibility that Glu83 is a contact site for the NKT cell receptor is also discussed.

Optical coherence tomography of tractional macular elevations in eyes with proliferative diabetic retinopathy

PURPOSE

To document the findings of optical coherence tomography in eyes with tractional macular elevation associated with proliferative diabetic retinopathy, paying special attention to differentiating between tractional retinal detachment and retinoschisis.

DESIGN

Observational case series.

METHODS

We retrospectively reviewed images of optical coherence tomography obtained from 17 consecutive eyes (17 patients) with proliferative diabetic retinopathy without vitreous opacity and showing tractional macular elevation with or without foveal involvement.

RESULTS

Tractional retinal detachment and retinoschisis could be differentiated in the cross-sectional images of optical coherence tomography. Retinoschisis with or without associated retinal detachment was observed in 16 of 17 eyes (94%), whereas retinal detachment was observed in only six of 17 eyes (35%). Five eyes showed both findings of retinal detachment and retinoschisis.

CONCLUSIONS

Optical coherence tomography is useful for distinguishing tractional retinoschisis from retinal detachment in eyes with proliferative diabetic retinopathy and macular elevation. Tractional retinoschisis with or without retinal detachment is the most frequent pattern of tractional macular elevation in eyes with proliferative diabetic retinopathy.

Cystoid macular edema associated with topical latanoprost in glaucomatous eyes with a normally functioning blood-ocular barrier

PURPOSE

To study prospectively using optical coherence tomography (OCT) whether topical latanoprost induces retinal disorders, such as cystoid macular edema, in patients with glaucoma and a normally functioning blood-ocular barrier.

METHODS

Sixty-eight eyes of 38 patients with glaucoma and no history of intraocular surgery, uveitis, or laser trabeculoplasty were studied. Before initiation of latanoprost treatment and after 1, 3, and 6 months of treatment, OCT images were taken, and the following tests were performed: visual acuity examination, fundus ophthalmoscopy, intraocular pressure measurement, and fundus color photography. To evaluate retinal thickness in the fovea accurately. OCT scanning was repeated six times, and the smallest value was used as the retinal thickness in the fovea.

RESULTS

Latanoprost ophthalmic solution did not influence retinal thickness in the fovea at any investigated time points compared with the time before instillation, and no changes were observed in visual acuity, ophthalmoscopic findings, and fundus photographs. The intraocular pressure was reduced significantly at all investigated time points compared with the time before instillation.

CONCLUSIONS

It is unlikely that topical latanoprost induces retinal disorders, such as cystoid macular edema, in glaucomatous eyes with a normally functioning blood-ocular barrier.

A sequence change (Arg158Gln) in the leucine zipper-like motif region of the MYOC/TIGR protein

The myocilin/trabecular meshwork-inducible glucocorticoid response (MYOC/TIGR) gene was identified as a gene that caused open angle glaucoma (OAG). Single-strand conformation polymorphism analysis and subsequent sequence analysis were performed for the MYOC/TIGR gene in 120 unrelated Japanese OAG patients with increased intraocular pressure (IOP), 116 unrelated OAG patients without increased IOP, and 106 unrelated control subjects without glaucoma. An Arg158Gln sequence change in the leucine zipper-like motif (LZM) region in the myosin-homology domain was found in 2 OAG patients with or without increased IOP, and in a 56-year-old control subject without glaucoma. This is the first report of missense sequence change in the LZM region of the MYOC/TIGR protein in subjects showing various phenotypes, including a control subject. These findings suggest that Arg158Gln in the LZM region is probably a rare nondisease-causing polymorphism, despite its important role in this region, because it was found in a control subject, although Arg158Gln was previously reported as a probable disease-causing mutation.

Effect of whole-body x-irradiation on antigen-induced airway response in sensitized guinea pigs

The objectives of this study were to test the hypothesis that x-irradiation inhibits the late asthmatic response (LAR) without influencing the early asthmatic response (EAR) and to examine the mechanism of the inhibitory effect. Twenty sensitized guinea pigs were irradiated at a dose of 8 Gy. The next day, one-half of the animals were injected intravenously with spleen cells (2 x 10(8)) collected from unirradiated sensitized guinea pigs, whilst the other half were injected with vehicle only. Ten additional unirradiated sensitized guinea pigs also received vehicle only. Antigen inhalation challenge took place two days later. Pulmonary resistance was measured for 6 h after antigen exposure, and bronchoalveolar lavage and lung fixation were then undertaken. The area under the percentage pulmonary resistance curve 2-6 h after allergen inhalation was used for analysis of the LAR, while the maximal percentage change in pulmonary resistance was used for analysis of the EAR. Irradiation abolished the LAR (364.4+/-49.4 versus 62.8+/-10.4) without inhibiting the EAR (229.3+/-27.2 versus 278.7+/-40.2) and significantly inhibited the accumulation of eosinophils and lymphocytes in the airways. Transfer of spleen cells restored the LAR (334.4+/-66.8) and the recruitment of cells to the levels seen in unirradiated sensitized guinea pigs. In addition, transfer of only CD4+ T-lymphocytes separated from the spleen cells restored the LAR (439.4+/-62.1) and the cell infiltration into the airways. These inhibitory effects of x-irradiation were due to decreases in numbers of CD4+ T-lymphocytes.

Double lesions are produced in DNA oligomer by ionizing radiation and by metal-catalyzed H2O2 reactions

It was demonstrated previously that double lesions are produced in DNA by ionizing radiation. These double lesions consist of adjacent nucleotides each bearing a modified base. The goal of the present investigation was to determine whether Fenton chemistry can generate the same kind of lesions. DNA oligomers were exposed to metal-catalyzed H(2)O(2) reactions, and the products were characterized by chromatography and by mass spectrometry. Double lesions are produced by this treatment in which deoxyguanosine is oxidized to 8-oxo-7,8-dihydrodeoxyguanosine and an adjacent pyrimidine nucleoside is degraded to a formamido remnant.

Nitric oxide and protein nitration are eosinophil dependent in allergen-challenged mice

To explore the possible role of eosinophils in NO-mediated tissue injury, we studied a murine model of allergic asthma. Male A/J mice were sensitized and challenged intranasally with ovalbumin (OVA). Following challenge, the number of eosinophils in bronchoalveolar lavage fluid (BALF) increased from 0.4% of total cells at baseline (0.02 x 10(4) cells/ml) to 60.2% at 48 h after the challenge (9.34 x 10(4) cells/ml). The rise in eosinophil count was accompanied by a 40.3% increase in total NO(2-) plus NO(3-) (NO(x)) in BALF. This in turn was accompanied by expression of inducible NO synthase (NOS II) in airway epithelial and inflammatory cells, as well as by evidence of staining for 3-nitrotyrosine (3NT) in peribronchial inflammatory cells and at the epithelial surface. Both NO(x) production and 3NT were significantly reduced by pretreatment of the challenged mice with the highly specific NOS II inhibitor N-3-aminomethyl-benzyl-acetamidine-dihydrochloride (1400W), as well as by the nonselective NOS inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME). L-NAME and 1400W also reduced the number of BALF eosinophils (37.2% and 61.5%, respectively, as compared with the control value), suggesting that NO production by NOS II contributes to eosinophil recruitment. To further examine the role of eosinophils, we pretreated additional mice with an anti-interleukin (IL)-5 antibody, which reduced BALF eosinophilia following OVA challenge by 90.1%. In concert with the decrease in eosinophils, the anti-IL-5 antibody reduced NO(x) in BALF almost to the baseline value, and decreased the number of 3NT-positive cells in the peribronchial region by 74.4%. Western blot analysis of protein extracted from whole lung confirmed the reduction in tyrosine nitration by anti-IL-5 antibody. These findings indicate that NO and eosinophilic inflammation are closely coupled, and suggest that eosinophils are an important source of tyrosine nitration.

Analysis of myocilin gene mutations in Japanese patients with normal tension glaucoma and primary open-angle glaucoma

The myocilin gene was identified as a gene (MYOC) that caused primary open-angle glaucoma (POAG). Although a normal tension glaucoma (NTG) patient with the myocilin gene mutation was previously reported, no study using large numbers of patients with NTG has been reported. Single-strand conformation polymorphism analysis and subsequent sequence analysis were performed for genotyping the myocilin gene in 114 unrelated Japanese patients with NTG. One hundred and nineteen patients with POAG and 100 control subjects without glaucoma were studied as reference subjects. Five amino acid sequence changes of the myocilin were identified: Arg46Stop (one NTG), Arg76Lys (four NTG, 10 POAG, seven control), Arg158Gln (one NTG, one POAG, one control) found in only Japanese, Asp208Glu (four NTG, three POAG, one control), Pro481Ser (one control). Pro481Ser was novel. Arg76Lys always occurred with 1-83 from G to A in the promoter as it was reported in Chinese. Although some Japanese patients with NTG had sequence changes of the myocilin gene, there were no apparent specific mutations in patients with NTG.

Mucosal immune network in the gut for the control of infectious diseases

The common mucosal immune system (CMIS) consists of an integrated cross-communication pathway of lymphoid tissues made up of inductive and effector sites for host protection against pathogenic microorganisms. Major effector molecules of the CMIS include IgA antibodies and cytokines, chemokines and their corresponding receptors. Secretory IgA (S-IgA), the major immunoglobulin, is induced by gut-associated lymphoreticular tissue (GALT)-derived B cells with the help of Th1- and Th2-type CD4(+) T lymphocytes. Cytotoxic T lymphocytes (CTLs) in the mucosal epithelium, a subpopulation of intraepithelial lymphocytes (IELs), also help maintain the mucosal barrier. The CMIS is unique in that it can provide both positive and negative signals for the induction and regulation of immune responses in both the mucosal and systemic compartments after oral or nasal antigen exposure. Prevention of infection through mucosal surfaces can be achieved by the CMIS through connections between inductive (e.g. GALT) and effector tissues. When vaccine antigens are enterically administered together with mucosal adjuvants [e.g. cholera toxin (CT), heat-labile toxin produced by Escherichia coli (LT) and IL-12], antigen-specific Th1/Th2 and IgA B cell responses are induced simultaneously in the mucosal effector compartment. Since these antigen-specific immune responses are not generated by oral vaccine without mucosal adjuvant, safe and effective adjuvants for the induction of antigen-specific S-IgA and CTL responses are essential for the development of mucosal vaccines for protection against infectious diseases. Finally, recent findings suggest the presence of a CMIS-independent IgA induction pathway, which also must be considered in the development of mucosal vaccines.

Natural killer cell tumoricidal activity and deterioration of lung tumor metastasis in silicotic mice and stressed silicotic mice

Aim of this study is to explore the role of splenic NK cells in the lung metastasis in the silicotic mice. The number of metastatic foci increased 1.5-fold and 1.8-fold in the silicotic and stressed silicotic mice compared with the control mice. Treatment with an immunomodulator reduced the rate of tumor metastasis in silicotic mice with or without stresses, while their NK cell activity was normalized. Decrease of NK cell activity on the day of tumor inoculation but not on the post-inoculation days seems to be a major factor for predicting the extent of tumor metastasis in the silicotic and stressed silicotic mice.

Homeobox protein Hex induces SMemb/nonmuscle myosin heavy chain-B gene expression through the cAMP-responsive element

Recent studies have shown that the homeobox gene Hex plays an important role in inducing differentiation of vascular endothelial cells. In this study, we examined the expression of Hex in vascular smooth muscle cells (VSMCs) in vitro and in vivo. Immunohistochemistry showed a marked induction of Hex protein in neointimal VSMCs after balloon injury in rat aorta. Western and reverse transcriptase-polymerase chain reaction analyses demonstrated that Hex was abundantly expressed in cultured VSMCs, whereas it was undetectable in other cell types or in normal aorta. The expression pattern of Hex was similar to that of SMemb/NMHC-B, a nonmuscle isoform of myosin heavy chain that we have previously reported to be a molecular marker of dedifferentiated VSMCs. We next examined the role of Hex in SMemb gene transcription. Promoter analysis demonstrated that the sequence identical to consensus cAMP-responsive element (CRE) located at -481 of the SMemb promoter was critical for Hex responsiveness. Mutant Hex expression vector, which lacks the homeodomain, failed to stimulate SMemb gene transcription, suggesting the requirement of the homeodomain for its transactivation. Elecrophoretic mobility shift assay showed that Hex binds to a consensus binding sequence for homeobox proteins, but not to CRE. Cotransfection of protein kinase A expression vector increased the ability of Hex to stimulate SMemb promoter activity in a CRE-dependent manner. Overexpression of CRE binding protein (CREB), but not Mut-CREB which contains mutation at Ser133, strongly activated Hex-induced SMemb promoter activity. These results suggest that Hex mediates transcriptional induction of the SMemb/NMHC-B gene via its homeodomain, and Hex can function as a transcriptional modulator of CRE-dependent transcription in VSMCs.

Perimetric sensitivity and retinal thickness in eyes with macular edema resulting from branch retinal vein occlusion

PURPOSE

To document and study the relationship between perimetric sensitivity and retinal thickness at the foveal and parafoveal points in eyes with macular edema associated with branch retinal vein occlusion.

METHODS

A prospective study was performed using the central 10-2 Humphrey perimetry program and optical coherence tomography. Seventeen eyes with branch retinal vein occlusion were eligible showing macular edema without macular nonperfusion or massive retinal hemorrhage.

RESULTS

The sensitivity and retinal thickness were significantly correlated at the fovea (r = -0.629, P =.006) as well as 1 (r = -0.656, P <.0001) and 3 (r = -0.885, P <.0001) degrees apart from the fovea. The visual acuity that is expressed as a logarithm of the minimum angle of resolution (LogMAR) also correlated with retinal thickness (r = 0.591, P =.011).

CONCLUSION

The increased retinal thickness resulting from macular edema is closely correlated with retinal sensitivity as measured by automated static perimetry both at the fovea and parafovea. Measuring the retinal thickness using optical coherence tomography may be useful in monitoring macular edema in eyes with branch retinal vein occlusion.

Basedow's disease and chronic ulcerative colitis: a case report and review of the Japanese literature

A case of Basedow's disease, that developed after successful treatment of ulcerative colitis with a total colectomy, is presented, along with a review of the Japanese literature on the coexistence of hyperthyroidism and ulcerative colitis. A 26-year-old man was referred to our department, complaining of general fatigue, appetite loss, and palpitation. At age 14, blood was discovered in his stool and a diagnosis of ulcerative colitis was made. Since then, he has been treated with salazosulfapyridine and prednisolone. On examination, mild exophthalmos and thyroid swelling were observed. Both serum free T3 and T4 levels were increased along with a positive TSH receptor antibody, while TSH was decreased. Scintigraphic and ultrasonographic examinations of the thyroid gland showed diffuse enlargement. Treatment with thiamazole relieved the symptoms and normalized the thyroid function. Although a high incidence of autoimmune thyroid diseases in association with ulcerative colitis has been suggested, only 6 cases of hyperthyroidism coexisting with ulcerative colitis have been reported in Japan. A common immunological process has been suggested to be implicated in the pathogenesis of this association, however, the exact mechanism remains unclear.

Neonatal inoculation with the protein-bound polysaccharide PSK increases resistance of adult animals to challenge with syngeneic tumor cells and reduces azoxymethane-induced precancerous lesions in the colon

We have investigated the results of neonatal inoculation with a protein-bound polysaccharide, PSK, as it affects the defense mechanism of animals against cancer. Male BALB/c mice received a single i.p. injection of 10 mg/kg PSK within 48 h of birth. When the mice were 8 weeks of age, colon adenocarcinoma 26 (C26 tumor) cells were transplanted s.c. Injection of PSK increased the number of tumor-rejecting mice from 10 to 50% compared with the control mice transplanted with 5 x 10(3) tumor cells and prolonged the median survival period to 174% of control mice with tumors. When the number of transplanted tumor cells was increased to 1 x 10(6), PSK injection significantly prolonged the survival period, although tumors grew in all mice. The survival period was also significantly prolonged in male C57BL/6 mice that received an injection neonatally with PSK and were given a s.c. transplant of Lewis lung carcinoma or B16 melanoma at 8 weeks of age. The effect on survival was dependent on the PSK dose and the number of transplanted tumor cells. PSK was as effective for male mice 30 weeks of age as for mice 8 weeks of age treated with PSK during the neonatal period. However, prolongation of the survival period of tumor-bearing mice was not observed in the offspring (F1). Neonatal injection of PSK also significantly reduced the number of metastatic foci in the liver of mice inoculated with 1 x 10(5) C26 tumor cells in the splenic vein after 8 weeks of age. In addition, neonatal injection of PSK significantly reduced the number of aberrant crypts and aberrant crypt foci, the precancerous lesions in the colon of F344 rats that received injections s.c. with azoxymethane after 7 weeks of age, to 47% of that of rats that received an injection with saline at the same age. The effect on precancerous lesions was dependent on the timing of PSK injection and the dose. Regarding the mechanism, when animals thymectomized during the neonatal period or when congenitally athymic animals were used instead of healthy animals, the effect on survival or precancerous lesions did not appear. Neonatal injection of PSK significantly reduced the number of CD4+ CD8+ T cells and significantly increased the number of CD4+ CD8- and CD4- CD8+ T cells in the thymus of healthy mice 10 weeks of age and C26 tumor-bearing mice. Furthermore, neonatal injection of PSK significantly elevated the T-cell differentiation induced by a mouse thymus extract 10 weeks of age. These findings suggest that neonatal injection of PSK induces resistance in adult mice to challenge by syngeneic tumor cells and reduces the azoxymethane-induced precancerous lesions in the colon of adult rats via the thymus functions.

[Macular diseases--application of automated static perimetry and optical coherence tomography]

The usefulness of automated static perimetry and optical coherence tomography in the management of macular diseases has been described. Scotomata in eyes with central serous chorioretinopathy could be evaluated with central 10-degree automated static perimetry. The degree of visual field defects in eyes with the disease varied greatly with mean deviation of -10 dB or less in as many as 10% of the subjects. Although retinitis pigmentosa is a diffuse retinal dystrophy, eyes with a moderately advanced stage of retinitis pigmentosa should be managed as a macular disease, because the functioning retina is confined within the vascular arcade. The progressive nature in this stage of the disease could be demonstrated with a central 10-degree automated static perimetry measured once or twice a year and the use of univariate linear regression of mean deviation, in half of the patients with a mean follow-up period of 5 years. Functional recovery in eyes with exudative age-related macular degeneration after laser surgery or submacular surgery could be evaluated with central 10-degree automated static perimetry. Eyes with increased mean deviation in spite of reduced visual acuity after therapeutic intervention should also be evaluated. Macular function could also be evaluated using a color test. A newly developed color saturation discrimination test was applied to patients with age-related macular degeneration, retinitis pigmentosa, and cone dystrophy. The degree of dyschromatopsia was less in eyes with age-related macular degeneration than in those with retinitis pigmentosa or cone dystrophy with the same level of acuity loss. The highly protrusive nature of the orange-red nodule in eyes with idiopathic polypoidal choroidal vasculopathy was demonstrated with dimensional measurement with OCT. The degree of protrusion was greater than in eyes with serous pigment epithelial detachment, which suggests that the polypoidal lesion is covered with rigid tissues including Bruch's membrane. Parafoveal retinal sensitivity obtained with automated static perimetry was studied in correlation with retinal thickness measured using OCT in eyes with branch retinal vein occlusion showing macular edema without macular non-perfusion or massive retinal hemorrhages. The increased retinal thickness due to macular edema is closely correlated with retinal sensitivity both at the fovea and in the parafoveal area. Eighty-nine phakic eyes of 46 patients with retinitis pigmentosa patients were studied to detect cystoid macular edema using OCT. Cystoid lesions were observed in the macula in 12 eyes in 6 (13%) of 46 patients. Some eyes with OCT-proven cystoid macular edema did not show dye pooling in the fluorescein angiogram. The width of the total area of cystoid lesions was positively correlated with best-corrected visual acuity but the thickness of the neurosensory retina at the center of the fovea was not. OCT findings of successfully repaired macular holes were categorized into 3 groups. Eyes with U-type showed a normal foveal contour and a dark layer corresponding to the outer segment of photoreceptors. Eyes with V-type showed a notch in the surface of repaired neurosensory retina without a dark layer on the retinal pigment epithelium. Those with W-type showed a defect of the neurosensory retina, where the retinal pigment epithelium was exposed. The visual results were excellent in eyes with U-type, but poor in those with W-type.

Alteration of V beta usage and cytokine production of CD4+ TCR beta beta homodimer T cells by elimination of Bacteroides vulgatus prevents colitis in TCR alpha-chain-deficient mice

A major pathogenic factor for the development of inflammatory bowel disease (IBD) is the breakdown of the intestinal homeostasis between the host immune system and the luminal microenvironment. To assess the potential influence of luminal Ags on the development of IBD, we fed TCR alpha(-/-) mice an elemental diet (ED). ED-fed TCR alpha(-/-) mice showed no pathologic features of IBD, and their aberrant mucosal B cell responses were suppressed. Similar numbers of CD4(+), TCR betabeta homodimer T cells (betabeta T cells) were developed in the colonic mucosa of ED-fed mice; however, Th2-type cytokine productions were lower than those seen in diseased regular diet (RD)-fed mice. The higher cytokine production in diseased RD-fed mice could be attributed to the high incidence of Bacteroides vulgatus (recovered in 80% of these mice), which can induce Th2-type responses of colonic CD4(+), betabeta T cells. In contrast, ED-fed TCR alpha(-/-) mice exhibited a diversification of Vbeta usage of betabetaT cell populations from the dominant Vbeta8 one associated with B. vulgatus in cecal flora to Vbeta6, Vbeta11, and Vbeta14. Rectal administration of disease-free ED-fed mice with B. vulgatus resulted in the development of Th2-type CD4(+), betabeta T cell-induced colitis. These findings suggest that the ED-induced alteration of intestinal microenvironments such as the enteric flora prevented the development of IBD in TCR alpha(-/-) mice via the immunologic quiescence of CD4(+), betabeta T cells.

Induction of cyclooxygenase-2 in rat gastric mucosa by rebamipide, a mucoprotective agent

Recent studies indicate an expression of mitogen-inducible cyclooxygenase (COX-2) in gastric mucosa. Rebamipide, a mucoprotective agent enhances prostaglandin (PG) synthesis. The present study was designed to clarify the mechanism for rebamipide-induced mucosal protection. Male Sprague-Dawley rats were administered 5, 15, or 50 mg/kg/day rebamipide for 14 days. The expression of constitutive cyclooxygenase (COX-1) and COX-2 in gastric mucosa was determined using Western blot analysis. Another series of rats was used to examine 1) the levels of PGE(2) in stomach with and without pretreatment with a COX-2 inhibitor; 2) the protective action of rebamipide against gastric damage caused by 0.6 N HCl; and 3) the effects of a COX-2 inhibitor on rebamipide-induced gastric mucosal protection. COX-2 expression was enhanced, whereas COX-1 expression did not change significantly in the gastric mucosa of rats after treatment with rebamipide. The gastric mucosal PGE(2) was higher in the rebamipide groups than in the vehicle-treated group. Rebamipide also suppressed gastric damage induced by HCl in a dose-dependent manner. A COX-2 inhibitor blocked the rebamipide-induced increase in mucosal PGE(2), and mucosal protection induced by rebamipide. The results indicate that rebamipide induces COX-2 expression, increases PGE(2) levels, and enhances gastric mucosal defense in a COX-2-dependent manner. Thus, COX-2 has an important role in the effects of rebamipide on gastric mucosal protection.

Expression of cyclooxygenase-2 and nitrotyrosine in human gastric mucosa before and after Helicobacter pylori eradication

To determine whether cure of Helicobacter pylori infection influences the expression of COX-2 and nitrotyrosine in the distal stomach of humans, biopsy specimens were examined immunohistochemically. H. pylori infection was determined using a rapid urease test, culture and histology. Positive staining of COX-2/nitrotyrosine in the epithelium was expressed as the percentage of stained cells to the total epithelial cells. There was a significant increase in COX-2/nitrotyrosine staining in H. pylori -positive subjects compared with H. pylori -negative subjects. Cure of the infection resulted in a significant decrease in both COX-2/nitrotyrosine staining in all patients (52.1+/-12.1% vs 15. 4+/-7.2%, P<0.001; and 57.3+/-13.6% vs 36.1+/-18.0%, P<0.01, respectively). However, immunoreactivity of COX-2/nitrotyrosine was observed in all cases with intestinal metaplasia even after the cure of H. pylori infection.Thus, cure of H. pylori infection may decrease the risk of gastric carcinogenesis due to COX-2 and NO-related compounds in gastric mucosa but not in those patients with intestinal metaplasia.

Dystrobrevin localization in photoreceptor axon terminals and at blood-ocular barrier sites

PURPOSE

Dystrobrevin is a newly discovered dystrophin-associated protein with multiple sites for phosphorylation on tyrosine residues. In the present study, the cellular distribution and subcellular localization of dystrobrevin were examined in the adult rat retina, cornea, lens, iris, ciliary body, and cultured Müller cells.

METHODS

Immunoblot analysis, confocal laser scanning microscopy, and immunoelectron microscopy were used to examine dystrobrevin expression.

RESULTS

Immunoblot analysis showed that an approximately 87-kDa band was expressed predominantly in the lens, retina, iris and ciliary body, whereas an approximately 60-kDa band was expressed in cultured Müller cells, cornea, retina, iris, and ciliary body. Confocal microscopy demonstrated dystrobrevin in the inner limiting membrane, outer plexiform layer, and retinal pigment epithelium and around blood vessels in the retina. At the ultrastructural level, dystrobrevin was localized under cell membranes of rod spherules and cone pedicles of photoreceptor cell terminals but often was found in the cytoplasm of endothelial cells and Müller cells. Furthermore, dystrobrevin was colocalized with beta-dystroglycan in corneal endothelium; lens, iris, and ciliary epithelia; and cultured Müller cells.

CONCLUSIONS

The present study demonstrates that dystrobrevin is expressed in neurons, glia, and endothelial cells in the rat retina. In addition, dystrobrevin is localized at the blood-ocular barrier sites in extraocular tissue. These data suggest that dystrobrevin plays an important role in visual function.

Detection of HIV-RNA in aqueous humor and subretinal fluid in an HIV carrier with rhegmatogenous retinal detachment

BACKGROUND

Although human immunodeficiency virus (HIV)-related ocular complexes are commonly observed in acquired immune deficiency syndrome (AIDS) patients, it has not been previously reported that HIV had already invaded the ocular tissues of HIV carriers.

CASE

A 56-year-old woman was diagnosed as having rhegmatogenous retinal detachment with a retinal tear in the 6-o'clock position in her right eye. No signs of ocular manifestations except the retinal detachment were observed. A blood examination revealed that she was already infected with HIV-1, and she was categorized as an HIV carrier.

OBSERVATIONS

Aqueous humor and subretinal fluid samples were obtained at the time of surgery for rhegmatogenous retinal detachment. Reverse-transcription polymerase chain reaction and Southern blotting at three regions of the HIV, LTR, gag, and env, confirmed the HIV infection in both aqueous humor and subretinal fluid. During the approximately 2-year follow-up after surgery, the patient did not show any signs of retinitis, uveitis, or other ocular manifestations.

CONCLUSIONS

This is the first report to reveal that HIV can invade the eye in the early stage of HIV infection. This infection may be related to HIV-related ocular complexes, which suppress the local immunological response.