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Biomedical subjects

Manabu Mochizuki

Publications and source records attributed to Manabu Mochizuki.

At least 55 records · Page 3Linked to original sources

Efficacy, safety, and pharmacokinetics of multiple administration of infliximab in Behçet's disease with refractory uveoretinitis.

OBJECTIVE: Behçet's disease (BD) with uveoretinitis is a chronic refractory disease accompanied by ocular attacks. As the decrease in visual acuity due to ocular attack is seriously life-threatening, development of a new drug is anticipated. Since tumor necrosis factor-a (TNF-a) is involved in the symptoms of BD, particularly the activity of ocular symptoms, suppression of TNF-a might be effective in treating BD with uveoretinitis. We conducted a clinical trial of infliximab, an anti-TNF-a chimeric monoclonal antibody, in patients with BD. METHODS: In this open label trial, the efficacy, safety, and pharmacokinetics of repeated administration of infliximab were evaluated in 13 patients with BD accompanied by refractory uveoretinitis. Infliximab was administered 4 times at Weeks 0, 2, 6, and 10 at doses of either 5 or 10 mg/kg by intravenous drip infusion. Frequency of ocular attacks was used as the primary index for evaluation of efficacy, with visual acuity and extraocular symptoms as secondary indices. RESULTS: The mean numbers of ocular attacks, converted to frequency per 14 weeks, were 3.96 times for the 5 mg/kg group and 3.79 times for the 10 mg/kg group during the observation period. Following treatment with infliximab, they decreased to 0.98 times and 0.16 times, respectively. A serious adverse event, tuberculosis, was observed in one case in the 10 mg/kg group. Serum infliximab concentration increased with dosage. CONCLUSION: Administration of infliximab in patients with BD with refractory uveoretinitis suppressed the frequency of ocular attacks, and multiple administration was well tolerated, suggesting that infliximab is effective for this condition.

Adolescent↗

[Histopathological findings in cytomegalovirus retinitis].

PURPOSE: We examined eyeballs collected from autopsied acquired immunodeficiency syndrome patients with cytomegalovirus (CMV) retinitis, and analyzed the precise pathogenesis of CMV retinitis. MATERIAL AND METHODS: Eyeballs were fixed with 10% buffered formalin embedded in paraffin. CMV antigens were investigated by histopathological and immunohistochemical analyses. Histopathological findings were compared with funduscopic images. RESULTS: CMV antigens remained in the necrotic area of the retina and many CMV immediate early antigens existed in intact parts of the inner retina showing almost intact structure, and around retinal vessels. CONCLUSIONS: The results suggest that CMV infects the inner retina first via the retinal vessels, although funduscopic examination may appear normal. It extends through the neuronal cells and glial cells horizontally and Muller cells vertically. CMV severely damages the retinal structure.

AIDS-Related Opportunistic Infections↗

Factors associated with the development of chorioretinal atrophy around choroidal neovascularization in pathologic myopia.

PURPOSE: To examine the influencing factors on the development of chorioretinal atrophy, which is the main cause of long-term visual decrease in myopic choroidal neovascularization (CNV), in a large series of highly myopic patients. METHODS: Sixty-five patients (81 eyes) with myopic CNV were studied retrospectively. The influence of the patient's age, refractive error, axial length, visual acuity at onset of CNV, size of CNV, and grade of myopic retinopathy on the extent of chorioretinal atrophy more than 3 years after CNV onset was investigated by means of multiple linear regression analysis. RESULTS: Seventy-seven of 81 eyes (95.1%) developed chorioretinal atrophy around myopic CNV during the follow-up period. Multiple linear regression revealed that age was the most influencing factor for the development of chorioretinal atrophy in all the subjects. When we divided the subjects into two groups according to their age, however, CNV size was the only factor to influence the development of chorioretinal atrophy in the patients younger than 40 years, whereas age was still the only influencing factor in those older than 40 years. CONCLUSIONS: The factors influencing the development of chorioretinal atrophy differ according to patient age. Local factors, such as CNV size, determine the tendency to develop chorioretinal atrophy in young patients. Systemic factors, such as patient age, play a greater part in older subjects.

Atrophy↗

Glucose hypometabolism in medial frontal cortex of patients with apraxia of lid opening.

PURPOSE: To determine whether regional cerebral functional abnormalities exist in patients with apraxia of lid opening (ALO). METHODS: Cerebral glucose metabolism was examined by positron emission tomography (PET) in 11 patients (8 women and 3 men, age 48-69 years); 10 with ALO accompanied by blepharospasm and 1 patient with pure ALO. Eleven normal volunteers (6 women and 5 men, age 45-66 years) were examined as controls. A comprehensive ophthalmological examination, magnetic resonance imaging (MRI), and PET were performed. The cerebral glucose metabolism was evaluated by the relative uptake of [fluorine-18]fluorodeoxyglucose by PET. The mean +/- two standard deviations of the normal controls was defined as the normal range for cerebral glucose metabolism. RESULTS: MRI revealed no particular lesion except for an infarction in the unilateral basal ganglia in two patients. Decreased glucose metabolism was observed in a wide area of the medial frontal lobe (six cases) and primary visual cortex (PVC) (four cases). Group multiple comparisons revealed a significant decrease ( P<0.0035) in the bilateral anterior cingulate gyrus, left supplementary motor area (SMA), and bilateral PVC. CONCLUSION: The results support the hypothesis that ALO is associated with hypofunction in the SMA and/or anterior cingulate gyrus.

Aged↗

Vascular endothelial growth factor upregulates pigment epithelium-derived factor expression via VEGFR-1 in human retinal pigment epithelial cells.

We previously demonstrated that differentiated retinal pigment epithelial (RPE) cells express high levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF), and a critical balance between VEGF and PEDF is important to prevent the development of choroidal neovascularization. We report here that VEGF secreted by RPE cells upregulates PEDF expression via VEGFR-1 in an autocrine manner. PEDF mRNA and protein expression was downregulated by neutralizing antibody against VEGF in differentiated human RPE cells. VEGFR-1 neutralization decreased PEDF mRNA and protein expression whereas anti-VEGFR-2 antibody had no effect. Addition of placenta growth factor (PlGF) restored PEDF expression in the presence of anti-VEGF antibody. These results demonstrate a regulatory interaction between angiogenesis stimulators and inhibitors to maintain homeostasis in normal human retina.

Cells, Cultured↗

Phenotypic change regulates monocyte chemoattractant protein-1 (MCP-1) gene expression in human retinal pigment epithelial cells.

We investigated the expression profile of monocyte chemoattractant protein-1 (MCP-1) in human retinal pigment epithelial (RPE) cells under different culture conditions and evaluated the molecular mechanism responsible for MCP-1 gene expression in RPE cells. After cellular confluence, total RNA was extracted and used for RT-PCR. Medium conditioned by RPE was used for ELISA and Western blotting. The result showed that RPE cells cultured on plastic expressed MCP-1 constitutively in the absence of any stimuli. On the other hand, growing human RPE on laminin-coated flasks instead of plastic reduced the production of MCP-1. In the RPE cells cultured on plastic, IkappaB was degraded and A20 protein increased concomitantly. MCP-1 upregulation in RPE cells on plastic was attenuated by the addition of MG-132, a proteasome inhibitor. Also, the addition of pyrolidine dithiocarbonate (PDTC) and hypoxic conditions (0.5% O2) decreased MCP-1 production in these cells. These findings suggested that the expression profile of MCP-1 is regulated by phenotypic alterations of the RPE cells. And the increased MCP-1 expression in RPE cells cultured on plastic is caused via spontaneous activation of NFkappaB induced by susceptibility to oxidative stress.

Blotting, Western↗

Prevalence and characteristics of foveal retinal detachment without macular hole in high myopia.

PURPOSE: To report the prevalence of foveal retinal detachment without macular hole in a large number of highly myopic eyes using optical coherence tomography (OCT), and to clarify the demographic characteristics associated with foveal retinal detachment in these eyes. DESIGN: A consecutive, prospective, observational case series. METHODS: In 134 eyes of 78 consecutive patients with high myopia (refractive error of -8 diopters or more), we performed complete ophthalmic examinations and studied cross-sectional images of the macula with OCT. The patients were divided into two groups according to the presence (group 1, n = 78 eyes of 45 patients) or absence (group 2, n = 56 eyes of 33 patients) of posterior staphyloma. Slit-lamp examination with a Goldmann three-mirror lens indicated that none of the eyes had a macular hole. RESULTS: In seven of 78 eyes (9.0%) with posterior staphyloma (group 1), OCT revealed foveal retinal detachment. Two of the seven eyes had foveal retinoschisis. Optical coherence tomography revealed no retinal detachment or retinoschisis in any eye without posterior staphyloma (group 2). Visual acuity of the seven eyes with foveal retinal detachment ranged from 20/40 to 20/200. Two of the seven eyes had visual acuity 20/50 or better. No patients complained of recent, progressive visual impairment. All seven eyes with foveal retinal detachment had severe myopic fundus changes (focal chorioretinal atrophy or bare sclera). CONCLUSIONS: In highly myopic eyes with posterior staphyloma, the prevalence of foveal retinal detachment without macular hole was 9.0%. In eyes with this type of retinal detachment, visual acuity varies and foveal retinal detachment tends to be missed on routine examination. Periodic examination using OCT is recommended for highly myopic eyes with severe myopic degenerative changes and posterior staphyloma.

Adolescent↗

Myopic choroidal neovascularization: a 10-year follow-up.

PURPOSE: To clarify the long-term visual outcome of choroidal neovascularization (CNV) in eyes with high myopia in Asian patients. DESIGN: We reviewed the medical records of 25 consecutive patients (27 eyes) with myopic CNV who were followed up for at least 10 years after the onset of CNV. Visual acuity was examined 10 years after CNV onset. INTERVENTION: Demographic and clinical data were obtained from the patients' medical records. MAIN OUTCOME MEASURES: Visual acuity readings during the 10 years after CNV onset. RESULTS: At the onset of CNV, 19 eyes (70.4%) had a visual acuity better than 20/200, and six eyes (22.2%) had a visual acuity better than 20/40. Three years after the onset of CNV, 15 eyes (55.5%) retained a visual acuity of better than 20/200. At 5 and 10 years after the onset, however, visual acuity dropped to 20/200 or less in 24 eyes (88.9%) and in 26 eyes (96.3%), respectively. The logarithm of the minimum angle of resolution (logMAR) visual acuity was significantly worse at 5 and 10 years after onset as compared with that at CNV onset. Chorioretinal atrophy developed around the regressed CNV in 26 eyes (96.3%) at 5 and 10 years after the onset of CNV. CONCLUSIONS: Long-term visual outcome of myopic CNV is extremely poor. The visual acuity of almost all of the patients dropped to 20/200 or less within 5 to 10 years after the onset of CNV, secondary to the development of chorioretinal atrophy around the regressed CNV. These findings indicate that active treatments should be recommended to prevent long-term visual impairment in Asian patients with myopic CNV.

Adult↗

Correlation between frequency doubling technology perimetry and temporal frequency characteristics in early glaucoma.

To assess the effectiveness of the temporal frequency characteristics (TFC) as an indicator of visual damage in patients with early open-angle glaucoma, TFC obtained from VEPs elicited by a pseudorandom binary sequence (PRBS) stimulus was compared with the frequency doubling technology (FDT) thresholds. Cross power spectrum between the PRBS stimulus as the input and the PRBS-VEPs as the output was calculated, and was used as the TFC. The normalized amplitude of the TFC at 2-4, 6-8, 10-12, 14-16, 18-20, 22-24, 26-28, and 30-32 Hz was calculated, and a coefficient of correlation between these values and the FDT thresholds was determined. The coefficients of correlation between the FDT thresholds and the TFC at 18-20 Hz for the central, 10 degrees, 20 degrees, and 30 degrees were r = 0.03, 0.31, 0.21, and 0.16, respectively in non-glaucomatous normal control eyes, and those for the same regions of eyes with early glaucoma were r = 0.66, 0.46, 0.38, and 0.35, respectively. The coefficients of correlation between the FDT thresholds and TFC at temporal frequencies were relatively high at 18-20 and 26-32 Hz. The time required to obtain the PRBS-VEP data was approximately the same as that for the FDT thresholds. The strong correlation between the two tests indicates that the FDT values and the high temporal frequency segments of the TFC may be useful as a preliminary indicator of visual damage in patients with early open-angle glaucoma. In addition, the strong correlation suggests that there was a preferential damage to the magnocellular system in glaucomatous eyes.

Aged↗

Prolonged exposure to high glucose impaired cellular behavior of normal human corneal epithelial cells.

PURPOSE: To determine the effect of prolonged exposure to high glucose on cellular behavior of normal human corneal epithelial cells (HCEC). METHODS: HCEC were cultured in medium under normal or high glucose conditions for 14 days. Proliferation was evaluated by direct cell counting and [(3)H]thymidine incorporation. Cell cycle analysis was performed using flow cytometry. The ability of HCEC to attach to type I collagen was evaluated using a short-term colorimetric adhesion assay. The effect of high glucose on the expression of integrin alpha(3)beta(1) was also evaluated using flow cytometry. RESULTS: Cell number and [(3)H]thymidine incorporation under high glucose conditions decreased compared with those under normal glucose conditions. The cells exposed to high glucose were G(0)/G(1) than untreated cells. The adhesion ability of HCEC under high glucose conditions decreased compared to normal glucose conditions. Expression of integrin alpha( 3)beta(1) was down-regulated under high glucose conditions. CONCLUSIONS: High glucose had deleterious effects on cellular behavior of HCEC, which might cause delayed corneal epithelial wound healing in diabetic keratopathy.

Antibodies↗

Reduced retinal angiogenesis in MMP-2-deficient mice.

PURPOSE: To study the putative role of endogenous matrix metalloproteinases (MMPs) in retinal neovascularization, an established mouse model was used to compare the retinal neovascularization observed in wild-type mice with that in mice without the MMP-2 or -9 genes. METHODS: C57Bl/6 (MMP-2(+/+) and -9(+/+)), MMP-2-deficient (MMP-2(-/-)), and MMP-9-deficient (MMP-9(-/-)) mice were used. After oxygen-induced retinopathy was induced in the mice, their eyes were rapidly removed and frozen in optimal cutting temperature embedding compound. Sections were histochemically stained with specific markers for vascular cells and angiogenesis-related factors. The area of new retinal vessels was measured using image-analysis software and compared between groups. RESULTS: Retinal neovascularization was not significantly different between wild-type and MMP-9(-/-) mice. The MMP-2(-/-) mice had significantly less extraretinal neovascularization than did wild-type mice. The mean number of extraretinal neovascular buds per cross section was significantly lower in MMP-2(-/-) mice than in wild-type mice (P < 0.05). The expression of other angiogenesis-related factors, vascular endothelial growth factor and pigment epithelium-derived factor, was not different between wild-type and MMP-2(-/-) mice. CONCLUSIONS: MMP-2 may be essential in the regulation of retinal neovascularization. Pharmacologic intervention using MMP inhibitors may be a future therapeutic approach for angiogenic retinal diseases.

Animals↗

Cytotoxicity for porcine islet cells by complement of six animal species.

Complement-mediated cytotoxicity for porcine islet cells (PICs) was evaluated using sera of six animal species. Then soluble complement receptor type-1 (sCR1) as an anti-complement agent was added to those sera, and the changes in 50% hemolytic unit of complement serum (CH50) and cytotoxic effect of those sera on PICs were examined. All the sera except for that of pig showed cytotoxicity. However, the extent of toxicity was considerably different between species. In the rat and human serum, sCR1 significantly reduced CH50 and cytotoxicity, however in the dog serum, sCR1 had no suppressive effects. These results may suggest that complement contribute to humoral cytotoxicity for PICs as a main factor, and the compatibility of complement with PICs differs between animal species.

Animals↗

Effects of midazolam-butorphanol, acepromazine-butorphanol and medetomidine on an induction dose of propofol and their compatibility in dogs.

The effects of acepromazine-butorphanol (AB), midazolam-butorphanol (MB) and medetomidine (Med) on the induction dose of propofol and their compatibility with propofol were evaluated in client-owned dogs. All premedications induced good to excellent sedation and the induction dose of propofol was considerably reduced. Of the tested premedicants, Med induced the deepest sedation and the most potent dose-sparing effect. Induction of anesthesia was excellent to good in all dogs except for one dog premedicated with MB. Most dogs premedicated with AB or MB showed temporary apnea. Although other adverse effects such as bradycardia or hypotension may also occur, premedication with MB, AB or Med is a valuable technique for the induction of anesthesia with propofol in dogs in a clinical setting.

Acepromazine↗

Clinical usefulness of propofol as an anesthetic induction agent in dogs and cats.

Propofol was used as an induction agent of general anesthesia in 77 dogs and 64 cats, all client owned, for a variety of surgeries/treatments or diagnostic procedures. The mean intravenous doses of propofol required to achieve endotracheal intubation in dogs and cats were 6.5 +/- 1.4 mg/kg and 10.1 +/- 2.8 mg /kg, respectively. Most of the animals could be induced to anesthesia smoothly by the administration of propofol with a high incidence of apnea. Propofol is a clinically valuable anesthetic induction agent in both dogs and cats, however, care must be taken for apnea.

Anesthesia, Intravenous↗

[A case of intraocular malignant lymphoma diagnosed by immunoglobulin gene rearrangement and translocation, and IL-10/IL-6 ratio in the vitreous fluid].

BACKGROUND: The diagnosis of primary intraocular lymphoma is difficult in many cases even with conventional cytological tests using vitreous samples. Recently new diagnostic tests, such as microdissection and polymerase chain reaction (PCR) and measurement of cytokines using intraocular samples, have been applied to the diagnosis of the disease. We report here a case where we used the new diagnostic tests and the results aided us to make a diagnosis of intraocular lymphoma. CASE: A 68-year-old woman with an initial diagnosis of bilateral idiopathic uveitis with steroid-resistant vitreous opacities underwent a vitreous biopsy. The cytological examinations of the vitreous samples revealed class III. The microdissection and PCR using the vitreous samples detected IgH rearrangement gene in the third framework (FR3A), the complementary determining region 3 (CDR3) of the VH region and Bcl-2-associated translocation. The interleukin (IL)-10 to IL-6 ratio in the vitreous fluid was greater than 100. Because the results of the examinations strongly suggested intraocular lymphoma, the patient was treated with radiation and chemotherapy. One month after the therapy, however, the patient developed multiple metastatic lesions in the brain. The clinical course of the patient together with the new diagnostic results of examinations led to a diagnosis of intraocular lymphoma. CONCLUSION: A combination of tests, such as conventional cytology, microdissection, and PCR, and cytokine assay using intraocular biopsy samples, is useful to make a diagnosis of intraocular lymphoma.

Aged↗

[Three cases of hypotonic maculopathy due to blunt trauma, treated by 360-degree scleral buckling].

BACKGROUND: In hypotonic maculopathy with a shallow anterior chamber, it is difficult to delineate the extent of cyclodialysis. Reoperations are often reported, and a method of management for hypotonic maculopathy is not yet established. CASES: We treated three patients with hypotonic maculopathy due to blunt trauma. Case 1 did not improve after two cryoablations, two cyclopexies, and a laser photocoagulation treatment. Cases 2 and 3 did not improve after a single laser photocoagulation treatment. All cases exhibited retinal breaks, and underwent 360-degree scleral buckling. RESULTS: In all cases, intraocular pressure was normalized soon after the surgery. We found that ultrasound biomicroscopy (UBM) was helpful in clarifying cyclodialysis, and that optical coherence tomography(OCT) was useful to observe morphologic changes of the macula in detail. CONCLUSION: This procedure is considered to be useful in the treatment of hypotonic maculopathy.

Adult↗

Detection of visual activation of lateral geniculate nucleus by positron emission tomography.

PURPOSE: Although activation of the lateral geniculate nucleus (LGN) has been shown by functional magnetic resonance imaging, a quantitative evaluation of the activity has not been reported by positron emission tomography (PET). The purpose of this study was to quantify the degree of activation of the LGN and other vision-related structures by visual stimuli as detected by PET. METHODS: PET activation was induced by a bolus injection of 15O-labelled water (H2(15)O) in six normal volunteers. The regional cerebral blood flow (rCBF) was measured under three conditions: eyes closed, binocular flickering light stimulation, and binocular viewing of a video movie. Single-subject analysis, group analysis, and correlation analysis were performed. RESULTS: Although single-subject analysis did not show significant changes, group analysis revealed a significant increase in rCBF in the left LGN induced by flickering light stimulation ( P<0.01) and video stimulation ( P<0.05). Localization of the activation foci in the LGN agreed with the retinotopic organization of the LGN. CONCLUSION: Although the LGN is relatively small compared with the resolution of the PET image, visually activated blood flow changes could be determined by H2(15)O PET:

Adult↗

Unusual response in mediated biosensors with an oxidase/peroxidase bienzyme system.

Mediated biosensors consisting of an oxidase and peroxidase (POx) have attracted increasing attention because of their wide applicability. However, since most of oxidases utilize artificial electron acceptors in place of dioxygen, the competition between O2 and the electron acceptor in the mediated sensors is anticipated. This has been evidenced with a glucose oxidase (GOx)- and POx-coentrapped and ferrocene-embedded carbon paste electrode, which exhibits peak-shaped current-time curves at increased concentrations of glucose and also gives a peak-shaped calibration curve. Digital simulation has been applied to clarify the cause of such unusual responses, by taking into account the ping-pong enzyme kinetics on two- and three-substrate models for POx and GOx, respectively. The simulation has well reproduced such unusual responses and has clearly revealed that the depletion of O2 in the enzyme layer is the most important factor responsible for such unusual responses. To overcome such a drawback of oxidase/POx bienzyme sensors, it is expected to be essential to decrease the rate of the oxidase reaction. In contrast, increase in the POx activity is useful to improve the sensitivity. According to the simulation-based expectation, the GOx and POx concentrations in the bienzyme sensor are adjusted to exhibit normal behavior with high sensitivity.

Biosensing Techniques↗