Michaelis-Menten analysis of immobilized enzyme by affinity capillary electrophoresis

Michaelis constant of enzymatic reaction was evaluated by affinity capillary electrophoresis using beta-galactosidase as a model enzyme and o- and p-isomers of nitrophenyl-beta-galactoside as substrates. The enzyme was immobilized on the inner surface of a fused-silica capillary by the covalent bonding through a bridging group, and the substrates were introduced into the capillary. The reaction products migrated electrophoretically toward the detection side (anodic side), while the unreacted substrates moved toward the injection side (cathodic side) on a slow electroosmotic flow generated by the weak negative charge of the immobilized enzyme. The initial velocity of the enzymatic reaction was estimated from the peak height of the product, and the Michaelis constant was calculated according to Lineweaver-Burk equation. The results (Km, 2.34 mM for o-isomer and 1.09 mM for p-isomer) were reproducible (RSD < 11.8%, n = 5). Although the estimated Michaelis constants were larger than the reported values measured in homogeneous solution, the ratio of the Michaelis constants of o-/p-isomers was in good agreement with the literature value. The present method required as low as a few microgram amount of enzyme and nanogram amount of substrate which is far smaller than those required in a conventional affinity HPLC.

[The characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid in hypertrophic cardiomyopathy with asymmetric septal hypertrophy]

The aim of this study was to elucidate the characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid (BMIPP) in the patients with hypertrophic cardiomyopathy (HCM). In 26 patients with asymmetric septal hypertrophy (ASH), the imaging data were acquired for 15 minutes after the injection of 123I-BMIPP by the emission computed tomography (ECT). ECT image was divided into 17 segments to score the severity of the defect in each segment using a 5-point grading system from score 3 to score -1; score 3 = severely decreased tracer uptake, score 2 = moderately decreased tracer uptake, score 1 = mildly decreased tracer uptake, score 0 = normal and score -1 = increased tracer uptake. Reduced uptake (Defect Score > or = 2) was frequently observed in septal portion of anterior wall (65%), septal portion of posterior wall (62%) and apical wall (73%). Defect score was higher in septal portion of anterior wall (p < 0.001), septal portion of posterior wall (p < 0.01) and apical wall (p < 0.01) than in the ventricular septum. This result indicates that in hearts with ASH, 123I-BMIPP image reveals severely impaired fatty acid metabolism in these regions. With the reference of the previous report about histologic features in necropsy hearts with HCM, myocardial fatty acid metabolic disorder shown by reduced 123I-BMIPP uptake is closely related to the histological abnormalities in hearts with HCM.

[Quantitative flowcytometric analysis of B cell surface antigens in patients with autoimmune diseases]

In 47 cases of autoimmune diseases (25 SLE, 9 MCTD, 6 PSS, 7 RA), two B cell surface antigens, CD19 and CD20 were quantitatively measured with a flowcytometer. When compared with the results of healthy controls, CD19 antigens were observed to be ca. 10% decreased in SLE and ca. 20% increased in RA. CD20 antigens were observed to be ca. 25% increased in SLE and no changes in RA. No significant increase nor decrease was observed with MCTD and PSS patients. In SLE patients, the amount of CD19 antigen expression was positively related to serum C3 levels, and that of CD20 antigen was negatively related to it. It is not obvious in what mechanism the expression of these antigens are regulated, however, from the point that the expression relates to the amount of serum C3 level, the quantitative measurement of CD19 and CD20 antigens is possibly be a good marker to detect the state of autoimmune disease such as SLE.

The SKM-1 leukemic cell line established from a patient with progression to myelomonocytic leukemia in myelodysplastic syndrome (MDS)-contribution to better understanding of MDS

Although molecular and cytogenetic studies strongly point to the role of oncogenes, the mechanisms underlying the development of MDS and their progressive evolution to AML are still largely unknown. It has been postulated that AML has a preleukemic stage and a multi step pathogenesis, with the preleukemic stem cell able to undergo clonal evolution, with the acquisition of karyotypic abnormalities, leading to the development of acute leukemic subclones. The activations of the ras oncogenes or inactivation of the p53 anti-oncogene by point mutations have been described recently in several cases of MDS as well as AML, suggesting a critical role for these alterations in the development of these myelogenous leukemias. We reported previously establishment of a leukemic cell line, SKM-1, from the patient who initially possessed multiple point mutations of ras genes but lost these mutations during disease progression to myelomonocytic leukemia with acquisition of chromosomal abnormalities involving the p53 anti-oncogene. This process is characterized by genetic instabilities probably due to the failure of their DNA repairment leading to abnormal control of cell proliferation and differentiation. Studying this cell line, SKM-1, is a promising approach to understand the mechanisms of the initiation, disease progression, alterations of DNA repairment, and genetic instability in MDS and myelogenous malignancies.

Study of the enantioselective binding between BOF-4272 and serum albumins by means of high-performance frontal analysis

High-performance frontal analysis (HPFA) was incorporated in an on-line HPLC system for the study of the enantioselective binding of BOF-4272, a new xanthine oxidase inhibitor, with human, bovine and rat serum albumins. This HPLC system consists of a HPFA column (diol-silica column), an extraction column (C4 column) and a chiral separation column (beta-cyclodextrin immobilized silica column), which were connected in series via two column switching valves. After the direct injection of a solution of 0.5-400 microM racemic BOF-4272 and 550 microM serum albumin onto the HPFA column, BOF-4272 was eluted, under a mild mobile phase condition (phosphate buffer, pH 7.4, ionic strength 0.17), as a zonal peak containing a plateau region. The drug concentration in the plateau region is the same as that for the unbound drug concentration in the sample solution. A given volume of this plateau region was transferred into the extraction column, and subsequently the extracted BOF-4272 was transferred into the chiral separation column to determine the unbound concentration of each enantiomer. The binding between BOF-4272 and the serum albumins was enantioselective and species dependent. The unbound concentration of the (+)-isomer in rat serum albumin solution was 1.04-1.14 times larger than that of the antipode, while the unbound concentration of the (-)-isomer in bovine serum albumin solution was 1.04-1.16 times larger than that of the antipode. The enantioselectivity of the binding between BOF-4272 and human serum albumin was concentration dependent.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracranial hemorrhage due to long-term anticoagulant therapy in patients with prosthetic heart valves--four case reports

Four patients with prosthetic heart valves suffered intracranial hemorrhage (cerebral hemorrhage in one patient, cerebellar hemorrhage in one, and chronic subdural hematoma in two) during long-term oral anticoagulant drug therapy (warfarin). In all patients, warfarin was discontinued and its effect neutralized by vitamin K, then surgery was performed after the thrombotest value exceeded 50%. No uncontrollable bleeding occurred at surgery. Warfarin was discontinued until 3-7 days postoperatively. Intravenous heparin administration was used to prevent embolic complications and the dose was modified based on the activated clotting time measured at the bedside. One patient, who could not receive heparin administration because of massive bleeding, developed myocardial infarction due to coronary artery thromboembolism 2 days after operation and died 4 days later. The other patients received heparin administration and were alive and well at the most recent follow-up examinations. Heparin administration monitored by activated clotting time is a useful method to prevent embolic and bleeding complications in the surgical treatment of intracranial hemorrhage in patients with prosthetic heart valves receiving long-term anticoagulant therapy.

Clear cell (glycogen-rich) meningioma with special reference to spherical collagen deposits

A detailed immunohistochemical and electron microscopic study of a case of clear cell (glycogen-rich) meningioma is presented. The neoplasm recurred three times and the patient died of the disease. The specimens obtained at all three operations showed similar basic histologic patterns. The tumor was comprised mainly of a syncytial, sheet-like proliferation of polygonal cells with clear cytoplasm containing abundant glycogen. The immunohistochemical features included epithelial membrane antigen- and vimentin-positive cytoplasm. The ultrastructural examination revealed distinctive meningocytic cells which contained large amounts of glycogen granules. In addition, the presence of numerous blocky, collagen conglomerations were a conspicuous feature of this tumor. The collagen deposits exhibited intensive immunopositivity for types I, III, IV and VI collagen, and their fine structure suggested the production of the extracellular matrix substance from the contiguous meningothelial cells with well developed Golgi complexes and frequent vesicles near the cell membrane. Proliferating cell nuclear antigen cell kinetics study revealed high labeling index of this neoplasm. The findings for this clear cell (glycogen-rich) meningioma may be useful in the differential diagnosis and treatment of this distinctive subtype of meningioma.

Cloning and sequence analysis of genes for cyclophilin from Arabidopsis thaliana

Two genomic DNA clones encoding cyclophilin (CyP) from Arabidopsis thaliana were isolated. The deduced protein products of these genes appeared to be cytosol-localized isoforms given the absence of a specific presequence for targeting to cellular compartments. Thus, multiple CyPs may exist and function in the cytosol of Arabidopsis thaliana.

Measurement of intracellular free Ca2+ concentration in guinea pig spiral ganglion cells

Intracellular free Ca2+ concentration ([Ca2+]i) in spiral ganglion cells (SGC) of guinea pig was measured using the fura-2 fluorescence method. Application of high-K+ external solution increased [Ca2+]i. [Ca2+]i elevation was suppressed by either depletion of external Ca2+ or application of the dihydropyridine Ca2+ channel antagonist, nicardipine. One of the putative hair cell afferent nerve neurotransmitters, L-glutamate (Glu), induced [Ca2+]i elevation in SGC. Pharmacological studies suggested that the Glu receptor may be a non-NMDA subtype. Glu-induced response was suppressed by either depletion of external Ca2+ or application of nicardipine, indicating that Glu-induced [Ca2+]i elevation is mainly carried out by the voltage-dependent Ca2+ channel in SGC.

Fetus-specific CYP3A7 and adult-specific CYP3A4 expressed in Chinese hamster CHL cells have similar capacity to activate carcinogenic mycotoxins

To assess whether CYP3A4 and CYP3A7 have a similar capacity to activate carcinogenic mycotoxins, we established cell lines stably expressing human CYP3A4 and CYP3A7, which are adult- and fetal-specific forms of cytochrome P450 in human livers, respectively. Each cDNA was introduced into CR-119 cells which had been established by introducing guinea pig NADPH-cytochrome P450 reductase cDNA into Chinese hamster lung cells. The cell lines (4-line and 7-line) stably expressed the mRNA and the protein corresponding to CYP3A4 and CYP3A7, respectively. The concentration-response for aflatoxin B1 (AFB1) cytotoxicity in 4-line and 7-line, respectively, was compared. 4-10 and 7-40 cells were approximately 17- and 20 times more sensitive to AFB1 than the parental CR-119 cells, respectively. In addition, the sensitivities to AFB1 of both 4-10 and 7-40 cells were enhanced approximately seven times by the addition of 10 microM alpha-naphthoflavone, a known activator of CYP3A enzyme, while the sensitivities were suppressed approximately four times by the addition of 100 microM troleandomycin, which forms a metabolite intermediate complex with CYP3A enzyme. Moreover, both cell lines showed approximately 10 and 2 times higher sensitivity to sterigmatocystin and aflatoxin G1 than CR-119 cells, respectively. These results indicate that CYP3A4 and CYP3A7 have essentially similar capacities to activate AFB1, sterigmatocystin, and aflatoxin G1 to produce toxic metabolites.

Parvalbumin-positive small myelinated fiber bundles in anterior marginal areas in the human cervical cord

During pathological examinations of amyotrophic lateral sclerosis (ALS) patients, we noticed that bundles of dense small myelinated fibers were relatively well preserved in the anterior marginal areas of the cervical cords in a few ALS patients with diffuse myelin pallor. Moreover, these fibers were strongly immunostained by anti-parvalbumin antiserum. These parvalbumin-positive fiber bundles were also seen in other ALS and non-ALS patients, and they were continuously traced up to the spinothalamic tract areas of the medulla oblongata. Therefore, it is suggested that these fiber bundles belong mainly to the ventral spinothalamic tract. We considered that these fiber bundles became conspicuous in shape since other areas in the anterolateral funiculus showed myelin pallor in such ALS patients.

Disturbance of regulation of sodium by cis-diamminedichloroplatinum in perilymph of the guinea pig cochlea

We studied the acute effects of cis-diamminedichloroplatinum (CDDP) on the cochlear partition and inner ear fluid in the guinea pig. At 48 hours after the administration of a single intramuscular injection of CDDP, 12.5 mg/kg of body weight, the endocochlear resting potential (EP) was significantly decreased to 32.1 +/- 1.8 mV in the treated animals, versus 80.6 +/- 1.0 mV in the control animals. There was a significant rise in potassium (K+), sodium (Na+), and chlorine (Cl-) in the endolymph of the animals treated with CDDP as compared with the control animals. Only Na+ was found to increase significantly in the perilymph, reaching more than twice the level of the control animals; both K+ and Cl- remained within the normal range. Serum electrolytes also remained within the normal range. Evaluation of modified ionic permeabilities across the endolymph-perilymph barrier showed an apparent increase in Na+ permeability and a normal range of K+ and Cl- permeabilities. Histopathologic examination of the cochlea showed a moderate collapse of the endolymphatic space, with atrophy of the stria vascularis and destruction of the outer hair cells. The findings suggest that the acute changes produced in the cochlea by administration of CDDP were attributable to a breakdown in the regulation of Na+ metabolism in the perilymph.

Potent thyrotropic activity of human chorionic gonadotropin variants in terms of 125I incorporation and de novo synthesized thyroid hormone release in human thyroid follicles

Using a highly sensitive bioassay for TSH, in which human thyroid follicles incorporate 125I and release de novo synthesized thyroid hormone into the culture medium, the thyrotropic activities of various hCG preparations were studied. Under the culture conditions employed, bovine TSH (bTSH) was approximately 6- to 9-fold more active than human TSH (hTSH). Highly purified hCG prepared from urine of normal pregnant women (CR 127) had only a trivial thyrotropic activity equipotent to 0.00022 microU bTSH/U hCG or 0.0013 microU hTSH/U hCG (19.7 microU hTSH/mg hCG). Hybrid hCG (AB1ER) also elicited low thyrotropic activity (14.0 microU hTSH/mg), whereas crude hCG had moderate thyrotropic activity (0.041 hTSH microU/U hCG or 127 microU/mg protein). Deglycosylated hCG, a very weak LH/hCG receptor agonist, was the most potent agonist in thyroid follicles (588 microU hTSH/mg protein). hCGs purified from urine of patients with trophoblastic tumors had greater TSH-like activity (37-84 microU hTSH/mg protein) than purified hCG. Asialo-hCG purified from a patient with choriocarcinoma had very potent TSH-like activity (468 microU hTSH/mg). Submaximal doses of bTSH and hCG variants produced additive stimulation of thyroid function. Furthermore, the thyrotropic effect of hCG was inhibited by anti-TSH receptor antibody obtained from patients with myxedema. These in vitro findings suggest that although hCG is reported to exert potent cAMP-stimulating activity on rat thyroid-like cells (FRTL-5) and Chinese hamster ovary cells transfected with hTSH receptor complementary DNA (0.092-0.72 microU hTSH/U hCG), the thyrotropic activity induced by authentic hCG in human thyroid follicles is too weak to cause hyperthyroidism in normal pregnancy. However, hCG produced by some trophoblastic tumors, particularly asialo-hCG, has potent thyrotropic activity sufficient to cause clinically overt hyperthyroidism when produced excessively.

[Percutaneous transluminal angioplasty for cervical carotid artery stenosis]

Percutaneous transluminal angioplasty (PTA) was attempted in 16 patients (17 procedures) with cervical internal carotid artery (ICA) stenosis. Among the 16 patients, 14 were male and 2 were female aged from 44 to 76 years (average 63.4 years). One had cerebral infarction on the acute stage, and the other 15 were in the chronic stage. On CT scan and MRI, there were nine multiple lacunar infarctions and seven watershed infarctions. On angiographical findings, 13 had Rt.-ICA stenosis and 4 had Lt. ICA stenosis. Stenotic lesion existed beyond the level of the third cervical vertebral body in eleven cases, and so-called long segmental stenosis ranged from 3 to 5 cervical vertebral bodies in 3 cases. Before PTA, 14 patients underwent a balloon occlusion test for 3 to 20 minutes (average 9 minutes). Neurological symptoms of hemiparesis or sensory disturbance occurred in 3 patients during balloon inflation, but these disappeared completely after balloon deflation. It took from 1.5 to 2 hours (average 1.7 hours) to carry out PTA including the balloon occlusion test. All cases had satisfactory results with no morbidity or mortality. The mean stenosis ratio of pre-PTA, approximately 80% (55-93%), improved to that of 22% (0-50%) after PTA. Bradycardia and hypotension occurred transiently in 9 cases during and after PTA, but no symptoms remained by atropine sulfate and catecholamine infusion intravenously. In the following 1 to 26 months (mean 9.0 months) after PTA, 3 cases restenosed. The restenosis was recognized by MR angiography after 8 to 26 months (average 15.7 months) of PTA.(ABSTRACT TRUNCATED AT 250 WORDS)

[Successful treatment with administration of systemic high dose methotrexate and intraarterial carboplatin for osteosarcoma of the skull: a case report]

An 11-year-old boy was admitted with a painless lump in the right frontal area as his chief complaint. On admission, physical and neurological examinations were normal except for the localized lump constituting the frontal lesion. Skull roentgenogram showed an osteoblastic and osteolytic mass with radiating bony spicules "sunray appearance" around the coronal suture. CT scans demonstrated it more clearly. The initial surgery was performed in July 1993. Pathological specimen showed osteosarcoma of the skull. The patient was transferred to our hospital for chemotherapy. The regimen consisted of intravenous high dose methotrexate 9,000 mg given for 6 hours with leucovorin rescue in a single course. Following 4 courses of high dose methotrexate, he underwent residual tumor resection. Two courses of intraarterial carboplatin 150 mg and methotrexate 200 mg were also given. Histologically, the lesion showed complete remission of the tumor, and no viable tumor cells were seen. Two additional courses of high dose methotrexate were given. The patient is doing well without evidence of recurrence. This case indicates that the chemotherapy with systemic high dose methotrexate and intraarterial carboplatin and methotrexate is effective for skull osteosarcoma.

Single photon emission computed tomography to determine effective hepatic blood flow and intrahepatic shunting

The noninvasive determination of effective hepatic blood flow, intrahepatic shunted blood flow, intrahepatic shunt index, and total hepatic blood flow was investigated by using the sequential single photon emission computed tomography. This method was performed for a period of 10 minutes following an intravenous injection of 99mTc-(Sn)-N-pyridoxyl-5-methyltryptophan and a venous blood sampling. This study comprised 8 healthy volunteers, 16 patients with chronic hepatitis, and 33 patients with liver cirrhosis. The intrahepatic shunt index measured with this method coincided with the intrahepatic shunt index determined by catheterization, indicating the high reliability of this procedure. The effective hepatic blood flow in patients with liver cirrhosis was significantly lower than that in the healthy controls and the chronic hepatitis group. The intrahepatic shunted blood flow was significantly higher in patients with liver cirrhosis compared with the flow in healthy controls. The intrahepatic shunt index was also significantly higher in patients with liver cirrhosis compared with the index of healthy controls and those with chronic hepatitis. No substantial differences were noted in the total hepatic blood flow among the three groups. The effective hepatic blood flow, the intrahepatic shunted blood flow, and the intrahepatic shunt index, correlated with the serum albumin concentration, the serum cholinesterase level, and the plasma indocyanine green attenuation rate. From these results, it was concluded that the present procedure constitutes a reliable and effective method for the noninvasive determination of hepatic blood flows. Consequently, it will be of high clinical value for assessing the functional and the pathological alterations of the liver.

Hostility is related to narcissism controlling for social desirability: studies of college students and patients with myocardial infarction

The authors examined the influence of narcissism and social desirability on hostility in two samples of 215 college students and 30 patients with myocardial infarction (MI). Results were as follows: (1) MI patients had stronger cynical hostility and lower social desirability than college students; (2) hostility was related to narcissism before and after controlling for social desirability in both MI patients and college students; and (3) these tendencies were stronger in MI patients than in college students, although there were no significant differences.

Influence of laparotomy on disposition kinetics of diclofenac in CCl4-intoxicated rats

The effect of the acute hepatic failure induced by CCl4 on the pharmacokinetics of diclofenac, which is definitely subject to enterohepatic circulation (EHC) in normal rats, was evaluated. This hepatic failure extinguished the secondary peak on the plasma time course which is usually observed in normal rats due to EHC. In the group without EHC by means of bile cannulation, the total clearance (CL) markedly decreased by CCl4-intoxication from 0.7 l/h/kg down to 0.1 l/h/kg, and mean residence time (MRT) increased from 0.29 h up to 2.8 h. The plasma time curves of the rats with laparotomy and with bile duct-cannulation were almost the same in the CCl4-intoxicated group. The bile excretion ratio of diclofenac markedly decreased by CCl4-intoxication from 43% down to 13%. In both groups, 92% of the total diclofenac excreted into the bile was glucuronide. While EHC made area under the curve (AUC) and MRT obviously increase in the CCl4-free rats, the effect of EHC on these moments was negligible in the CCl4-intoxicated rats. In the CCl4-intoxicated condition, the elimination of diclofenac in the rats with laparotomy was considerably slower than that in the rats without laparotomy. The plasma time courses were obviously monoexponential in the former group, while those were almost biexponential in the latter group.

DAMGO, a mu-opioid receptor selective agonist, distinguishes between mu- and delta-opioid receptors around their first extracellular loops

The structural basis of mu-opioid receptor (OPR) for the specificity in its ligand binding was investigated using chimeric mu/delta-OPRs. Replacement of the region around the first extracellular loop of delta-OPR with the corresponding region of mu-OPR gave the resultant chimeric receptor the similar affinity to DAMGO compared with the native mu-OPR. The reciprocal replacement deprived the high affinity to DAMGO from mu-OPR. These results indicate that the difference(s) in the structure around the first extracellular loop is critical for DAMGO to distinguish between mu- and delta-OPRs. Furthermore, displacement studies revealed that this region is partly involved in the discrimination between mu- and delta-OPRs by other peptidic mu-selective ligands, such as dermorphin, morphiceptin and CTOP, but not by non-peptidic ligands, such as morphine and naloxone.

Hemorrhagic colitis with unusual colonoscopy features, complicated with chronic graft-versus-host disease after allogeneic bone marrow transplantation

A 32-year-old man was admitted after bone marrow transplantation because of hematochezia. He had history of chronic graft-versus-host disease (GVHD) of the skin and the liver, and cytomegaloviral pneumonia. Barium enema and colonoscopy showed multiple colon ulcers in the ascending and transverse colon. This feature is very rare in chronic GVHD and resembles the feature in autoimmune disease such as periarteritis nodosa. Thus, this ulceration is thought to be caused by vasculitis due to an autoimmune reaction in chronic GVHD.

[Rheumatoid factor and cryoglobulin are not efficiently related to cold activation of complement]

Cold activation of complement (CA) is a phenomenon characterized by a low hemolytic complement activity in chilled serum. Cryoglobulin and RF have been reported as main causes of CA, and we previously reported the close association between CA and HCV infection in 21 CA patients. Therefore, we assayed CA, RF, cryoglobulin and anti-HCV antibody titers in 304 randomly selected patients with unknown diseases. CA was positive in 26 of the 304 patients, and among them, RF and/or cryoglobulin were found positive in 20 patients, and anti-HCV antibody were positive in all of them. RF was positive in 41 of the 304 patients. 37% of them were anti-HCV antibody positive and 63% were negative. Cryoglobulin was positive in 61 out of 304 patients. Anti-HCV antibody positivity was observed in 59 out of 304 patients, and all CA-positive cases were included in the anti-HCV antibody-titer-positive group. However, either RF or cryoglobulin positive patients were observed in the same degree in both anti-HCV antibody titer positive and negative groups. Therefore, RF or cryoglobulin is not considered the main cause of CA.

The emergence of free radicals after acoustic trauma and strial blood flow

The effect of acoustic trauma on cochlear strial circulation was investigated immunohistologically in the guinea pig. Kanamycin was used as a tracer of blood flow. Moreover, histochemical examinations were made to reveal the emergence of free radicals in the cochlea following acoustic trauma. At 5 min (5 min after intense sound exposure 120-125 dB SPL, 3 h) the blood flow in the stria vascularis was greatly diminished. At 2 h the strial blood flow started to recirculate and at 6 h it appeared to have returned to normal. Superoxide anion radicals (O2-) emerged along the luminal membrane of the marginal cells of the stria vascularis at 5 min. O2- disappeared at 30 min, but reappeared at 2 h. The cause of its emergence at 5 min was obscure. However, the strange phenomenon that O2- emerged again at 2 h seemed ascribable to the re-circulation of strial blood flow after sound exposure.

[A case of cutaneous malignant melanoma metastatic to the choroid]

A case of metastasis of cutaneous malignant melanoma to the choroid was reported. The patient, a 61-year-old man, had undergone an amputation of his right first finger 3 years ago due to cutaneous malignant melanoma. Ophthalmoscopic examination revealed a whitish yellow elevated choroidal lesion and serous retinal detachment in the left eye. Fluorescein angiography demonstrated multiple pinpoint leaks in the early phase and progressive pooling of dye into the subretinal space in the late phase. In magnetic resonance imaging, the tumor showed a hyperintense image in both T1 and T2-weighted images. Autopsy was performed and histopathological examination of the eye showed that the tumor cells were polygonal in shape, and had round or oval nuclei, but the cytoplasms had little melanin pigment. Immunohistochemistry for S-100 and HMB-45 antibody showed positive staining in choroidal tumor and other metastatic lesions, indicating that they were metastatic tumors from cutaneous malignant melanoma (amelanotic melanoma cells).