[Determination of Chlorothalonil Metabolite I in Livestock Products by LC-MS/MS].

An analytical method based on LC-MS/MS was developed for the determination of chlorothalonil metabolite I in livestock products. Chlorothalonil metabolite I in livestock products was extracted with acetone. The crude extracts were defatted by acetonitrile and n-hexane partitioning. Cleanup was carried out using a combination of ethylene diamine-N-propyl silylation silica gel (PSA) and silica gel (SI) mini columns with acidic condition. The sample solution was subjected to LC-MS/MS using an external solvent calibration curve. The average recovery (n=5) of chlorothalonil metabolite I from five types of livestock products (cattle muscle, cattle fat, cattle liver, milk and egg) spike at the maximum residue limits (MRLs) or at a uniform limit of 0.01 mg/kg was 97.1-102.9%, with a relative standard deviation of 1.4-6.8%. The limit of quantitation of the developed method was calculated to be 0.01 mg/kg.

Gain of human torsional optokinetic nystagmus depends on horizontal disparity.

PURPOSE: To investigate the effects of horizontal disparity on torsional optokinetic nystagmus (tOKN) in humans. METHODS: Ten healthy human subjects were selected for this experiment. Monocular eye movements were recorded three-dimensionally using dual-search coil methods. Torsional OKN was induced by a rotating random-dot pattern (22 degrees in diameter, constant angular velocity: +/-54 deg/s) projected on the virtual screen of the optical see-through, head-mounted display (HMD). The optical distance of the HMD's virtual screen was 2 m. A red LED that could be fixated through the virtual screen of the HMD was located near the center of the rotating random-dot pattern. Horizontal disparity was induced by changing the distance between the fixated target and the subject systematically (1, 1.5, 2, or 3 m; five subjects) or by the prism (+1.5, +0.5, 0, or -0.5 prism-diopter [PD] in each eye; five subjects) in front of the HMD. RESULTS: The average gain with zero horizontal disparity (0.022 +/- 0.008/0.025 +/- 0.014, fixated target at 2 m/fixated target with the plain glass) was significantly higher than the gain with crossed disparity (0.017 +/- 0.003/0.019 +/- 0.008, target at 3 m/with the prism of -0.5 PD) and uncrossed disparity (0.017 +/- 0.002, target at 1 m/with the prism of +1.5 PD; one-way ANOVA, P <0.05). CONCLUSIONS: The horizontal disparity of optokinetic stimulus affects tOKN. Nonzero horizontal disparity decreases the gain of tOKN.

Relationship of dissociated optic nerve fiber layer appearance to internal limiting membrane peeling.

PURPOSE: The dissociated optic nerve fiber layer (DONFL) appearance features numerous arcuate striae after vitrectomy for idiopathic epiretinal membrane or macular hole. We studied the relation between the DONFL appearance and internal limiting membrane (ILM) peeling and performed static microperimetry to explore the possible mechanisms underlying the DONFL appearance. DESIGN: Prospective cohort study. PARTICIPANTS: Ninety-five eyes of 88 consecutive patients undergoing vitrectomy for idiopathic macular hole. METHODS: Vitrectomy and gas tamponade were performed with or without ILM peeling. All eyes were examined postoperatively using fundus photography with blue filters. Static microperimetry was performed in 31 eyes with a clearly visible DONFL appearance. MAIN OUTCOME MEASURE: The postoperative incidence of the DONFL appearance on blue-filtered fundus photographs. The secondary outcome measure included the microperimetry threshold value in the arcuate striae and the surrounding normal retina within the papillomacular bundle. RESULTS: On blue-filtered photographs, 46 (62.2%) of 74 eyes with ILM peeling exhibited the DONFL appearance, compared with 0 (0%) of 21 eyes without ILM peeling (P = 0.0002). The area of the DONFL appearance was limited to the area of ILM peeling. There was no difference in the microperimetry threshold value between the arcuate striae and the surrounding normal retina (P = 0.9312). CONCLUSION: The present study indicates that the DONFL appearance might be related to ILM peeling and is not associated with the loss of optic nerve fibers. These results are consistent with the suggestion that the DONFL appearance might be caused by cleavage of the optic nerve fiber bundles due to damage to the Müller cells, which are in close contact with the ILM and act to maintain the close proximity of the nerve fiber bundles.

A review of 244 orbital tumors in Japanese patients during a 21-year period: origins and locations.

PURPOSE: To review 244 cases of orbital tumors to determine the distribution of patient age, pathology, and tumor origin and location. METHODS: We reviewed cases of histopathologically or radiologically verified orbital tumors at our institution from 1981 through 2002, and studied the distribution of patient age, pathology, origin of tumors, and tumor location in the orbit in 244 consecutive patients (aged from 0 to 90 years, mean, 48.7 years; 114 men, 130 women). RESULTS: Among the 244 cases, 213 (89%) were primary orbital tumors, 23 (9%) were secondary tumors originating in contiguous spaces, and 8 (2%) were metastatic tumors. Regarding the location in the orbit, 122 tumors (50%) were extraconal, 36 (15%) were intraconal, and 86 (35%) were in the lacrimal gland area. The common tumors were reactive lymphoid hyperplasia (22%) and malignant lymphoma (20%) in the extraconal area; cavernous hemangioma (25%), optic nerve glioma (14%), and optic nerve sheath meningioma (14%) in the intraconal area; and malignant lymphoma (40%) and pleomorphic adenoma (24%) in the lacrimal gland area. The age distribution of the 244 patients exhibited two peaks, at 0 to 9 years and 60 to 69 years. In the 0- to 9-year-old patients, the most common tumors were dermoid cyst (26%), optic nerve glioma (11%), capillary hemangioma (11%), and hemorrhagic lymphangioma (11%). On the other hand, in patients over 40 years of age, the common tumors were malignant lymphoma (31%), orbital pseudotumor (24%), pleomorphic adenoma (10%), and cavernous hemangioma (9%). CONCLUSIONS: The pathologic profiles of orbital tumors were characterized according to patient age and the location of the tumor in the orbit. The age of onset, tumor location, and radiological findings provide us with important information for the diagnosis of a tumor prior to biopsy or tumor resection and for the determination of the treatment strategy.

Transition from upbeat to downbeat nystagmus observed in a patient with Wernicke's encephalopathy.

BACKGROUND: We report an unusual case of Wernicke's encephalopathy presenting with transient upbeat nystagmus that changed to a persistent downbeat nystagmus. CASE: A 27-year-old man presented with upbeat nystagmus. Three months earlier, he had been diagnosed with Wernicke's encephalopathy after fasting for a month. OBSERVATIONS: This diagnosis was supported by his symptoms (ataxia, a confused state). Clinical recovery followed thiamine therapy. His upbeat nystagmus had linear slow phases with average amplitude and frequency (+/-SD) during fixation straight ahead of 2.8 +/- 0.7 degrees and 4.6 +/- 2.2 Hz, respectively. Two months later, the primary position upbeat nystagmus had diminished and downbeat nystagmus (0.9 +/- 0.5 degrees and 3.2 +/- 0.7 Hz on average) for a 20 degrees downward gaze had developed. Then, 8 months later, he showed only downbeat nystagmus, which obeyed Alexander's law. His primary position downbeat nystagmus was completely suppressed by clonazepam, a gamma-aminobutyric acid (GABA) agonist. CONCLUSIONS: Owing to an underlying central vestibular imbalance, even after the recovery of acute neurological symptoms, Wernicke's encephalopathy can be complicated by persistent downbeat nystagmus, which can be treated by a GABA agonist.

An unusual case of congenital convergent convergent strabismus fixus.

BACKGROUND: Convergent strabismus fixus is classified into congenital and acquired types; however, there are only a few detailed case reports of congenital convergent strabismus fixus. Here, we report a rare case of this condition in which the eyeball was shown by imaging diagnosis to be fixed with a hard cord-like material in the orbit. To our knowledge, there have been no previous reports of congenital convergent strabismus fixus caused by an abnormal cord-like material that was clearly identifiable by imaging. CASE REPORT: The patient was a 16 year old female who visited our department for consultation regarding restoration of normal appearance of her strabismus. She had undergone strabismus surgery at the age of 3 years, but a forced duction test was strongly positive in all directions, and the eyeball was not mobile at the time. The initial surgery performed was a tenotomy of the medial rectus muscle and inferior rectus muscle and resection of the lateral rectus muscle of the right eye. The eye position and eye movement remained unchanged after surgery. At this time, MRI of the orbital region was performed, and an abnormal cord-like material connecting the posterior eyeball to the orbital wall was detected in the orbit. The cord-like material was pulling strongly on the posterior eyeball, congenitally fixing the eye position internally. CONCLUSION: We experienced a rare case in which a hard cord-like material in the orbit congenitally fixed the position of the eyeball. On MRI, the intensity of the cord-like material was clearly different from those of the muscle and nerve tissues. Considering the linearity of the cord-like material and the results of a forced duction test, the cord-like material probably consisted of fairly hard tissue, similar to bone.

Neurotrophic factor receptors in epiretinal membranes after human diabetic retinopathy.

OBJECTIVE: Formation of epiretinal membranes (ERMs) in the posterior fundus results in progressive deterioration of vision. ERMs have been associated with numerous clinical conditions, including proliferative diabetic retinopathy (PDR), but its pathogenic mechanisms are still unknown. This study was conducted to determine whether neurotrophic factor receptors (tyrosine kinase receptors trkA, trkB, and trkC; low-affinity neurotrophin [NT] receptor p75 [p75(NTR)]; glial cell line-derived neurotrophic factor receptor-alpha1 [GFR alpha 1] and GFR alpha 2; and Ret) are involved in the formation of ERMs after PDR. RESEARCH DESIGN AND METHODS: ERM samples were obtained by vitrectomy from 19 subjects with PDR aged 57 +/- 8 years with 17 +/- 8 years of diabetes and 15 subjects with idiopathic ERM. They were processed for RT-PCR analysis. In addition, 11 ERM samples from PDR patients aged 47 +/- 18 years with 13 +/- 4 years of diabetes were processed for immunohistochemical analysis. RESULTS: Expressions of trkA, trkB, trkC, p75(NTR), and Ret mRNAs were similar in both groups. In contrast, GFR alpha 2 expression levels were significantly higher (17 of 19 vs. 2 of 15 subjects in idiopathic ERM, P < 0.0001) in PDR subjects. Accordingly, immunohistochemical analysis revealed expression of GFR alpha 2 protein in all of the 11 ERMs derived from PDR patients, and that region was double-labeled with glial cell-specific markers. On the other hand, GFR alpha 1 expression was lower (8 of 19 vs. 12 of 15 subjects with idiopathic ERM, P = 0.0258) in PDR subjects. CONCLUSIONS: These results suggest a possibility that glial cell line-derived neurotrophic factor receptor (GDNF) subtypes are differently involved in the formation of ERMs.

Diverse NF-kappaB expression in epiretinal membranes after human diabetic retinopathy and proliferative vitreoretinopathy.

PURPOSE: Formation of epiretinal membranes (ERMs) after proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR) results in progressive deterioration of vision, but its pathogenic mechanisms are still unknown. This study was conducted to examine the role of nuclear factor kappa B (NF-kappaB) in the formation of ERMs after PDR and PVR. METHODS: ERM samples were obtained by vitrectomy from 10 patients with PDR (aged 53+/-12 years with 14+/-5 years of diabetes), 20 patients with PVR, and 17 patients with idiopathic ERMs. Ten PVR and 17 idiopathic ERM samples were processed for reverse transcription-polymerase chain reaction (RT-PCR) analysis. In addition, 10 PDR and 10 PVR membranes were processed for immunohistochemical analysis. RESULTS: NF-kappaB mRNA expression levels were significantly higher (10 of 10 versus 9 of 17 subjects in idiopathic ERM, p=0.0119) in PVR subjects. Immunohistochemical analysis showed NF-kappaB protein expression in 8 of the 10 PDR samples as well as all 10 PVR samples, and NF-kappaB positive cells were partially double labeled with glial cell markers. Interestingly, NF-kappaB protein was also overlapped with angiogenic factor interleukin-8 (IL-8) in glial cells as well as vascular endothelial cells. CONCLUSIONS: These results suggest that NF-kappaB is involved in the formation of both glial and vascular endothelial cell components, and that these two cell types might have functional interactions that lead to the enlargement of intraocular proliferative membranes.

Invasive thymoma with paraneoplastic retinopathy.

A 60-year-old man was admitted for progressive visual loss in both eyes. He was diagnosed with retinopathy and chest computed tomography revealed an invasive thymoma. In western blot analysis, serum autoantibodies against recoverin, photoreceptor-specific calcium-binding protein, and heat shock cognate protein 70 which were identified as the cause of cancer-associated retinopathy (CAR). Immunofluorescence staining showed that thymoma cells also expressed recoverin. These observations strongly suggested that similar pathogenesis of CAR was involved in the presented case.

Convergence eye movements evoked by microstimulation of the rostral superior colliculus in the cat.

Results of our previous studies suggest that the circumscribed area in the rostral superior colliculus (SC) of the cat is involved in the control of accommodation. Accommodation is closely linked with vergence eye movements. In this study, we investigated whether or not vergence eye movements are evoked by microstimulation of the rostral SC in the cat. In addition, we studied the effect of chemical inhibition of the rostral SC on visually guided vergence eye movements. This study was conducted on three cats, weighing 2.5-3.5 kg. The animals were trained to carry out visually guided saccade and convergence tasks. Eye movements were measured using search coils placed on both eyes. We recorded eye movements evoked by microstimulation of the rostral SC in the alert cats. Muscimol was injected into the rostral SC, and the effect of SC inactivation on visually guided vergence eye movements was investigated. Convergence eye movements were evoked by low-current stimulation (< 30 microA) of a circumscribed area in the intermediate layers of the rostral SC on one side. Spontaneous saccades were interrupted by the stimulation of the low-threshold area for evoking convergence. Visually guided convergence eye movements were severely diminished by the injection of muscimol into the low-threshold area for evoking convergence of the SC. The rostral SC is related to the control of vergence eye movements as well as accommodation. The rostral SC may be involved in the functional linkage between accommodation, convergence and visual fixation.

High incidence of orbital malignant lymphoma in Japanese patients.

PURPOSE: To review 244 cases of orbital tumors to determine pathologic findings in Japanese patients. DESIGN: Observational case series. METHODS: We studied the pathology and origin of tumors in the orbit in 244 consecutive Japanese patients with orbital tumors at our institution from 1981 through 2002 (age 0 to 90 years, mean, 48.7 years; 114 men, 130 women). RESULTS: The most common tumors were lymphoproliferative diseases (n = 114, 42.5%), including malignant lymphoma (n = 59, 24.1%) and reactive lymphoid hyperplasia (n = 45, 18.4%), pleomorphic adenoma (n = 21, 8.6%), and cavernous hemangioma (n = 18, 7.4%). CONCLUSION: The incidence of lymphoproliferative diseases, especially malignant lymphoma, was very high in Japanese patients.

Accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus.

PURPOSE: To report a patient who developed accommodation and convergence palsy caused by lesions in the bilateral rostral superior colliculus. DESIGN: Observational case report. METHODS: A 30-year-old right-handed man experienced sudden onset of diplopia and blurred vision at near vision. RESULTS: The patient showed accommodation and convergence palsy. Magnetic resonance imaging revealed lesions located in the bilateral rostral superior colliculus. CONCLUSION: These findings suggest that the rostral superior colliculus is involved in the control of accommodation and vergence eye movements.

Three-dimensional eye movement analysis of superior oblique myokymia.

PURPOSE: To confirm the idea that sole contraction of the superior oblique muscle causes attacks of superior oblique myokymia (SOM). DESIGN: Observational case report. METHODS: A 43-year-old man presented with episodic monocular oscillatory eye movements. Three-dimensional eye movements were recorded using the magnetic search coil system and analyzed as rotation vector. The attacks of SOM consisted of intorsional, depressive, and abductive fast phases and their exponential decaying slow phases. RESULTS: Average direction of rotation axis for the fast phases while fixating straight ahead was 51.5 +/- 5.4 degrees from depression axis in vertical-torsional plane, 78.7 +/- 4.4 degrees from abduction axis in horizontal-torsional plane, and 76.3 +/- 4.3 degrees from abduction axis in horizontal-vertical plane (+/-SD, n = 50). Time constants of slow phases were less than 0.1 second. CONCLUSIONS: Quantitative three-dimensional analysis of SOM directly confirmed that the fast phases of SOM attacks were induced by the sole contraction of the superior oblique muscle.

Rhegmatogenous retinal detachment after rupture of retinal arterial macroaneurysm.

PURPOSE: To report two cases of rhegmatogenous retinal detachment following rupture of retinal arterial macroaneurysm. DESIGN: Observational case report. METHODS: Review of clinical records of 75 consecutive eyes (73 patients) with macroaneurysm. RESULTS: Ruptured macroaneurysm was present in 68 of the 75 eyes, and rhegmatogenous retinal detachment developed spontaneously in 2 (2.9%) of the 68 eyes. In the 2 eyes with retinal detachment, there were no predisposing lesions to retinal detachment and the detachment occurred either 2 weeks or 1 month after the rupture of a macroaneurysm. Retinal detachment and posterior vitreous detachment developed simultaneously after bleeding from the macroaneurysm spread into the vitreous in 1 eye. CONCLUSIONS: We report the occurrence of retinal detachment after macroaneurysmal rupture. Detailed fun-dus examination is required to detect retinal detachment in the follow-up of patients with ruptured macroaneurysm.

Effect of steroid pulse therapy with and without orbital radiotherapy on Graves' ophthalmopathy.

PURPOSE: To report the effect of high-dose intravenous corticosteroid pulse therapy with and without orbital radiotherapy on Graves' ophthalmopathy. DESIGN: Nonrandomized clinical trial. METHODS: We selected 39 Japanese patients (age range, 22-64 years; mean, 48 years; 31 women, 8 men) who had active Graves' ophthalmopathy among 195 consecutive patients. In the first 20 patients, high-dose intravenous methylprednisolone pulse therapy (1 g per day for 3 successive days, repeated 3 times within 3 weeks) followed by 24-Gy orbital radiotherapy was performed. In the other 19 of the 39 patients, high-dose intravenous methylprednisolone pulse therapy without orbital radiotherapy was performed. Coronal computed tomography (CT) of the orbit and exophthalmometry were performed before the corticosteroid pulse therapy, and 1 and 6 months after the corticosteroid pulse therapy. The maximum coronal section area of the most hypertrophic rectus muscle in each eye was measured based on orbital CT imaging. RESULTS: Clinical findings at study entry were not significantly different between the two groups. No significant difference was found in the maximum coronal section area of the most hypertrophic rectus muscle and the results of exophthalmometry measurements in both groups before the therapy. Extraocular muscle hypertrophy was significantly reduced 1 month and 6 months after the therapy (P < .01) in both groups. However, no beneficial therapeutic effect on proptosis was observed in either group at 1 month and 6 months after the therapy. No significant difference in the therapeutic effect on extraocular muscle hypertrophy and proptosis was found between the two groups. CONCLUSIONS: Orbital irradiation after corticosteroid pulse therapy had no beneficial therapeutic effects on rectus muscle hypertrophy or proptosis of active Graves' ophthalmopathy during the 6-month follow-up period.

Macular hole formation following ruptured retinal arterial macroaneurysm.

PURPOSE: To report four cases of macular hole formation following ruptured retinal arterial macroaneurysm. DESIGN: Case-control study. METHODS: Review of clinical records of 75 consecutive eyes (73 patients) with macroaneurysm. Macroaneurysms were confirmed using either fluorescein angiography or indocyanine green angiography or both that indicated a telangiectatic retinal vascular change. Clinical data of patients with macroaneurysm with and without macular hole (MH) formation were compared retrospectively. RESULTS: Of 75 eyes, four (5.3%; four patients) with macroaneurysm had a macular hole. In one of the four eyes, a macular hole was detected 2 days after the rupture. The distance from the macroaneurysm to the center of the fovea was significantly closer in the four eyes with a macular hole (MH group, 1.1 +/- 0.4 (mean +/- standard deviation [SD]) disk diameter) than in the 71 eyes without a macular hole (non-MH group, 1.9 +/- 0.9 disk diameter) (P =.0196). The incidence of subretinal hemorrhage in the macula was significantly greater in the MH group (100%) than in the non-MH group (35.2%) (P =.0195). CONCLUSIONS: Macular hole formation associated with ruptured macroaneurysm is not as uncommon as previously thought. We suggest that there might be early onset of macular hole formation following ruptured macroaneurysm. Macroaneurysms with early-onset macular hole are present near the center of the macula and are accompanied by subretinal hemorrhage in the macula.

Nodular scleritis and panuveitis with erythema elevatum diutinum.

PURPOSE: To report a case of nodular scleritis and panuveitis associated with erythema elevatum diutinum, a rare immunocomplex-mediated skin disease. DESIGN: Observational case report. METHODS: A 22-year-old woman who was diagnosed with erythema elevatum diutinum developed nodular scleritis and panuveitis of the right eye. She had experienced peripheral ulcerative keratitis with corneal perforation. RESULTS: All other known causes of nodular scleritis and panuveitis were investigated and ruled out. CONCLUSIONS: Erythema elevatum diutinum should be considered as an underlying systemic disease associated with nodular scleritis and panuveitis as well as peripheral keratitis.

Optical coherence tomographic findings of dissociated optic nerve fiber layer appearance.

PURPOSE: To examine the features of optical coherence tomographic (OCT) findings of dissociated optic nerve fiber layer (DONFL) appearance. DESIGN: Case-control study. METHODS: Twenty-four eyes undergoing vitrectomy for idiopathic epiretinal membrane or macular hole were examined postoperatively using OCT. RESULTS: Thirteen of the 24 eyes exhibited the DONFL appearance. In these 13 eyes, the OCT images indicated dimples in the retinal nerve fiber layer (RNFL) corresponding to each stria. The RNFL thickness (mean +/- SD) at the dimple site was 38.1 +/- 9.3 microm. The depth of each dimple was 28.6 +/- 8.0 microm. The depths of all the dimples were limited to the RNFL thickness. In the other 11 eyes without the DONFL appearance, OCT images showed no distinct dimples. CONCLUSIONS: The DONFL appearance is caused by dimples the depths of which are limited to the RNFL thickness.

N-acetylaspartate concentration in the chiasm measured by in vivo proton magnetic resonance spectroscopy.

PURPOSE: To measure the concentration of N-acetylaspartate (NAA) in the chiasm of both normal controls and patients with chiasmal optic neuritis by in vivo proton magnetic resonance spectroscopy (1H-MRS). METHODS: Ten normal subjects (age range, 22 to 40 years; mean, 31 years; seven men and three women) and two patients with chiasmal optic neuritis were examined at the Sapporo Medical University Hospital. Localized 1H-MRS spectra of the chiasm were obtained using a whole-body 1.5-T magnetic resonance system. RESULTS: 1H-MRS spectra of the chiasm were obtained in all subjects. The level of NAA concentration in the optic chiasm was 15.73 +/- 1.43 mM (mean +/- SD) in normal subjects. In contrast, the NAA levels in the two patients with chiasmal optic neuritis were significantly lower (P < 0.001). The level of NAA in the two patients was significantly increased after improvement of visual acuity and visual fields following corticosteroid pulse therapy. CONCLUSIONS: These results suggest that 1H-MRS enables us to estimate the concentration of NAA in the chiasm. The NAA concentration in the optic nerve measured by 1H-MRS may be a new clinical parameter to monitor the axonal damage following optic neuritis.

Leaky neural integration observed in square-wave jerks.

PURPOSE: To clarify the neuronal mechanism for the square-wave jerks (SWJs). METHODS: A 66-year-old man presented with oscillatory eye movements. He showed horizontal nystagmus in rightward gaze and SWJs during fixation at straight ahead. We recorded his eye movements with search coil methods and quantitatively analyzed them. RESULTS: Visually guided rightward saccades were followed by exponential drifts with average time constants of 0.3-1.0 second, indicating a leaky rightward velocity-to-position integrator. Amplitude of SWJs ranged from 0.5 to 2.5 degrees and average intersaccadic interval was 0.2 seconds. In addition, exponential drifts similar to those observed after visually guided saccades were observed in the SWJs. Rightward fast eye movements of SWJs were followed by exponential drifts lasting for 0.2 seconds with average time constant (+/-SD) of 0.7+/-0.3 seconds. CONCLUSIONS: Position signals after visually guided saccades and SWJs were outputs of the identical velocity-to-position integrator. SWJs are generated by the neural circuits involving a pulse generator and a velocity-to-position integrator.