Ako Nakajima

Decreased tear lactoferrin concentration in patients with chronic hepatitis C

BACKGROUND/AIMS Decreased tear volume in patients with chronic hepatitis C has been reported in the literature. Lactoferrin is abundantly present in human tears, the main source of which is the acini of the lacrimal glands. In this study tear lactoferrin levels were measured to investigate the dry eye condition of patients with chronic hepatitis C. METHODS Lactoferrin in tears/fluid was measured by a radial immunodiffusion assay in 42 patients with chronic hepatitis C. The rate of lacrimal secretion was determined by the cotton thread test. Rose bengal staining of the ocular surface was also performed. RESULTS Only three patients out of 42 complained of dry eye sensation and, in 31 patients, six showed positive results on the rose bengal staining test of the ocular surface. The lactoferrin concentration of tear fluid in the chronic hepatitis C group (1.42 (SD 0.56) mg/ml) was significantly lower than in the control group (1.90 (0.62) mg/ml; p <0.00048). The cotton thread test results in the chronic hepatitis C group (12.9 (5.5) mm) were significantly lower than in the control group (17.9 (5.3) mm; p<0.00048). Also, in the chronic hepatitis C group, tear lactoferrin concentration correlated with the results of the cotton thread test (r = 0.35, p<0.05). CONCLUSION Chronic hepatitis C patients showed both decreased tear volume, and decreased tear lactoferrin concentration. These findings suggest that there may be dysfunction of the lacrimal glands in patients with chronic hepatitis C, which may account for the mild dry eye.

Suppression of Experimental Autoimmune Uveoretinitis by Dietary Calorie Restriction

To investigate the inhibitory effect of dietary calorie restriction on experimental autoimmune uveoretinitis (EAU) in rats, and its mechanism. Lewis rats were maintained on a 50% calorie-restricted diet for 2 months or 6 months. The control group was maintained on a 90% ad libitum intake for the same length of time. Experimental autoimmune uveoretinitis was elicited in both groups by immunization with an inter-photoreceptor retinoid-binding protein or its peptide. Rats in both groups were examined clinically, histopathologically, and immunologically. The severity of EAU was milder in the restricted diet group than in the control group. In EAU rats, production of interferon-gamma (IFN-gamma) in eyes and of IFN-gamma and tumor necrosis factor-alpha in draining lymph node cells was significantly lower in the restricted diet group than in the control group. Our results indicate that a calorie-restricted diet suppresses the development of EAU. The suppressed Th1-dependent immunological response is one of the reasons for the mildness of EAU in the calorie-restricted diet group of rats.

Intraocular pressure during pneumatic retinopexy.

BACKGROUND AND OBJECTIVE A simplified method of monitoring intraocular pressure (IOP) during pneumatic retinopexy was devised and used clinically to decrease the risk of complications associated with unnecessary IOP elevation. PATIENTS AND METHODS Intraoperative IOP and IOP immediately after sulfur hexafluoride (SF6) injection were monitored during pneumatic retinopexy in 22 eyes with rhegmatogenous retinal detachment. Intraoperative IOP was measured with a sphygmomanometer connected to the side of a gas-filled syringe. RESULTS Intraoperative IOP and IOP immediately after gas injection were 97.2 +/- 28.5 (mean +/- SD) and 46.5 +/- 19.6 mm Hg, respectively. Two eyes temporarily lost light perception immediately after the gas injection. The intraoperative IOP and the IOP immediately after the gas injection were 130 and 80 mm Hg, respectively, in one eye, and 180 and 90 mm Hg, respectively, in the other. CONCLUSIONS In general, to ensure effective and safe results of pneumatic retinopexy, the authors recommend that the gas be injected either to approximately 90 mm Hg of intraoperative IOP or to the maximum acceptable volume (2.0 to 2.5 ml of 100% SF6).

Analysis of uveitogenic sites in phosducin molecule.

PURPOSE Phosducin, a retinal photoreceptor protein, induces experimental autoimmune uveitis (EAU). In this study, we attempted to determine the numbers of uveitogenic sites in phosducin using synthetic peptides. METHODS Antigen peptides were synthesized according to the amino acid sequence of the rat-derived phosducin with a peptide-synthesizer and purified by reversed-phase HPLC. First, 13 peptides covering the entire sequence of phosducin were synthesized, and each was injected into the hind footpad of Lewis rats for immunization, and induction of EAU was examined clinically and histologically. Next, peptides that appeared to contain sequences of a uveitogenic site were newly synthesized and examined clinically and immunologically. RESULTS Of the 13 peptides used in the first immunization, 7 induced inflammation. Similar to other EAU antigens, clinical changes began with fibrin deposition in the anterior segment and posterior synechia, followed by posterior chamber hypopyon. Histologically, inflammation was observed mainly in the outer segment of photoreceptor cells and outer nuclear layer, and serous retinal detachment was found in cases of severe inflammation. Infiltration of inflammatory cells in the pineal gland was also observed. In experiments designed to further specify the uveitogenic sites, the presence of inflammation-inducing sequences was inferred for amino acid sequences 1-20, 23-37, 79-91, 127-142 and 198-212. The rats immunized with these peptides also exhibited high value on lymphocyte proliferation assay. CONCLUSION Phosducin has 5 uveitogenic sites. Among others, one of them has potent and others weak uveitogenicity.

Two cases of malignant lymphoma complicated by hemophagocytosis resembling orbital cellulitis

Two patients with malignant lymphoma complicated by hemophagocytic syndrome (HPS) are reported. Their clinical signs at onset were similar to those of orbital cellulitis. Lymphoma complicated by hemophagocytosis is called lymphoma-associated hemophagocytic syndrome (LAHS) and its prognosis is reported to be very poor. As far as we know, this is the first report in the ophthalmological field. In our patients, we suspected that the lesions occurred from the orbit or skin of this area. The first patient was a 22-year-old man and the second patient a 16-year-old girl. The diagnosis was very difficult at the onset of disease. They died within 6 months after the first ophthalmological examination. When orbital cellulitis is suspected and antibiotic therapy is ineffective, we should suspect HPS and should examine serum ferritin, which is a good marker of HPS. Early biopsy and consultation with a hematologist are very important.

Uveitopathogenic sites in recoverin.

Purpose. This study was carried out in order to determine the most potent and novel uveitopathogenic sites of recoverin using synthetic peptides. Methods. Several synthetic peptides containing the recoverin sequence plus adjuvants were injected into Lewis rats, and the uveitopathogenic sequence was defined, clinically, histologically, and immunologically. Results. Peptides containing of amino acids 57–85 and 136–167 induced severe EAU, and the lowest doses to induce EAU were 20 µg and 10 µg, respectively. Lymphocyte proliferative reactions were also positive for peptides 57–85 and 136–167. The core sequences within the uveitopathogenic site were 65–79 and 153–164. Peptides of amino acids 65–79 within 57–85 and 149–167 within 136–167 were the smallest in the recoverin sequence, respectively, that could induce severe EAU. Conclusion. We found recoverin has some novel potent uveitopathogenic sites, 149–167. These findings of the uveitopathogenic sites in recoverin may lead to improved understanding of the pathogenesis of uveitis and the means to design specific treatment.

Fas Expression and Apoptosis in Rats with Experimental Autoimmune Uveoretinitis

PURPOSE To evaluate Fas expression on CD4 and CD8 T cells in each organ at each stage of experimental autoimmune uveoretinitis (EAU) and apoptotic cells within EAU eyes. METHODS Rats were immunized with the uveitopathogenic peptide derived from interphotoreceptor retinoid-binding protein. Flow cytometry was performed in ocular cells, draining lymph nodes cells and splenic cells of EAU rats to investigate Fas expression by CD4 and CD8 lymphocytes. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining of apoptotic nuclei was performed on sections of EAU eyes. RESULTS Fas expression by both ocular and splenic CD4 and CD8 lymphocytes was significantly higher than in lymph nodes at each stage. In EAU eyes, there was a relatively large population of lymphocytes with Fas expression (19.6-25.6% of CD4 and 33.2-53.4% of CD8). Apoptotic cells were more prominent in the EAU eyes with established disease than in those with early or resolving disease. CONCLUSIONS These results suggest that the relatively large population of lymphocytes with Fas expression in EAU eyes reflects the activation of lymphocytes in these eyes, and that the increase in apoptotic inflammatory cells at the peak of established disease may participate in the spontaneous disappearance of EAU.

Decreased Serum Melatonin Levels in Rats with Experimental Autoimmune Uveitis/Pinealitis and in Patients with Uveitis

The authors measured serum levels of the pineal hormone melatonin to investigate the possibility of pineal dysfunction in both rats with experimental autoimmune uveitis/pinealitis (EAU/EAP) and uveitis patients. The serum melatonin concentrations of EAU/EAP rats were measured by radioimmunoassay over a 24-hour (h) period, and in uveitis patients at night (0200 h). Melatonin concentrations were assayed in six patients with Behçets disease, four with Vogt-Koyanagi-Harada (VKH) disease, three with sarcoidosis, three with Kirisawa-type uveitis, and one with tubulointerstitial nephritis and uveitis syndrome. Nocturnal serum melatonin levels were significantly lower in Lewis rats with EAU/EAP (2200 h: 33.6±20.4 pg/ml, 0200 h: 43.2±13.9 pg/ml) than in the controls (2200 h: 117.5±25.3 pg/ml, 0200 h: 132.4±20.2 pg/ml) (p>0.01, at 2200 h and 0200 h). Melatonin levels were significantly lower in VKH disease (20.7±10.5 pg/ml) (p>0.01) and Behçets disease (42.1±42.5 pg/ml) (p>0.05) than in the controls (79.4±36.7 pg/ml). These results suggest that there is a decrease in pineal gland function due to pinealitis in EAU/EAP rats. The markedly decreased nocturnal serum melatonin levels may also be related to the presence of retinal uveitogenic antigens in uveitis patients.

Uveitopathogenic Site of the γ-Subunit of Cyclic Guanosine Monophosphate Phosphodiesterase in Lewis Rats

PURPOSE The gamma-subunit of cyclic guanosine monophosphate phosphodiesterase (PDEgamma) plays an important role in the phototransduction process of rod photoreceptors. A previous report indicated that experimental autoimmune uveoretinitis (EAU) could be induced in Lewis rats by immunization with PDEgamma. In this study, we identified the uveitopathogenic site of PDEgamma synthetic peptides and identified pivotal amino acid residues using analogue peptides. METHODS Several synthetic peptides derived from PDEgamma plus adjuvants were injected in Lewis rats. The induction of EAU was examined clinically and histologically. In addition, humoral and cellular immunity against peptides was investigated. RESULTS The smallest uveitopathogenic peptide was identified as PDEgamma 64-76 (ITVICPWEAFNHL), which consists of 13 amino acid residues, and the core sequence was identified as PDEgamma 70-76 (WEAFNHL), which consists of 7 amino acid residues. The lowest dose of peptide to induce EAU was 0.03 nmol. The pivotal amino acid residues for eliciting EAU are at 70(W), 71(E), 73(F), and 75(H). CONCLUSION Our findings demonstrated the presence of a potent uveitopathogenic site in PDEgamma whose potency in Lewis rats was comparable to that of interphotoreceptor retinoid-binding protein.

Clinical course, immune response, and histopathology of a simplified model of experimental lens induced endophthalmitis in rats.

YAG laser capsulotomy 14 days after one-shot immunization of bovine lens soluble protein with Freunds complete adjuvant and simultaneous intravenous injection of Bordettella pertussis caused lens induced endophthalmitis (LIE) in Lewis rats. Exudate first appeared in the anterior chamber eight hours after capsulotomy. In the cases of low dose (20μg/rat) immunization, exudative change was localized around the ruptured lens surface. On the other hand, the anterior chamber was filled with thick exudate in high dose (200μg/rat) immunized rats. By ELISA and lymphocyte proliferation assay, serum and lymphocyte from LIE rats reacted with bovine uvea as well as bovine lens, but showed no cross-reactivity with bovine retina. Histopathological finding in the low-dose immunized rats was granulomatous inflammation localized to the anterior eye segment, but high dose-immunized rats developed severe panophthalmitis and showed epithelioid granulomas in disorganized retina. The authors think this low dose model can contribute to therapeutic or suppressive studies.