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Biomedical subjects

M Tamai

Publications and source records attributed to M Tamai.

At least 217 records · Page 12Linked to original sources
PubMed1992

[A case of chronic progressive external ophthalmoplegia with Oguchi's disease].

A 52-year-old case of chronic external ophthalmoplegia accompanied by Oguchi's disease was reported. The patient noticed night blindness and deafness since childhood. Later he developed ocular movement limitation to all directions by the age of 40. He had 20/20 corrected visual acuity and normal anterior segment, as well as normal color vision. Goldmann's perimetry showed generalized constriction of the peripheral field. Golden tapetal reflex without dark adaptation disappeared after 4 hours of dark adaptation, i.e. Mizuo-Nakamura's phenomenon was recognized. Recovery of diminished a and b wave electroretinogram to the subnormal range was also observed after 4 hours of dark adaptation. Rod-cone interaction test revealed a monophasic adaptation, and no suppression to the cones from the rods was observed. This finding was also compatible with Oguchi's disease. ECG revealed incomplete atrio-ventricular as well as right bundle branch blocks. Neurological examination findings were entirely normal other than slight enhancement of deep tendon reflexes in the lower extremities and mixed typed difficulty of hearing. Muscle biopsy of the right medial rectus muscle revealed ragged-red fiber, suggesting mitochondrial abnormalities. Never the less the quadriceps femoris muscle biopsy specimen showed normal histological findings. This is the first case report of progressive external ophthalmoplegia associated with Oguchi's disease. Mitochondrial abnormality was confirmed only in the external ocular muscle. This case may be a variant of Kearns-Sayre syndrome.

Humans↗
PubMed1992

[pO2, pCO2 and acid-base balance in the human vitreous sample].

In order to clarify the physiological profile in vitreous cavity undergoing vitrectomy, both human vitreous and venous blood samples were obtained to measure pO2, pCO2, acid-base balance and potassium. A new collection system was employed to obtain vitreous samples from 15 eyes under local or general anesthesia. The mean vitreous pO2 was higher than that of venous blood, and was affected by irrigative air more than breathed oxygen. Irrigating air was considered to be one of the best methods to supply enough oxygen concentration to the inner retina during the vitrectomy. Although the vitreous pH showed alkalosis during the air irrigation, it was suggested that to protecting the retina, the vitreous bicarbonate buffer was not enough to compensate for the decrease in the vitreous pH.

Acid-Base Equilibrium↗
PubMed1992

[An epidemiogenetic study of typical retinitis pigmentosa in Japan--a preliminary report of nationwide, multicenter study].

We performed a nationwide, multicenter study of typical retinitis pigmentosa with reference to the inheritance patterns of the disease. A total of 253 probands were registered during two months of 1989, and an analysis of the parental consanguinity of 182 probands with the method of inbreeding coefficient enabled us to estimate the relative prevalence of genetic types; autosomal recessive trait: 47.6%; autosomal dominant trait: 17.3%; sporadic cases: 34.6%. A comparison of the results with previous studies has indicated a decrease in the prevalence of the autosomal recessive trait and an increase in the sporadic cases, as would be expected from the decrease in consanguineous marriages and offsprings in the past few decades in Japan. X-linked retinitis pigmentosa was rarely identified, but precise evaluation of its frequency needs further investigation.

Adolescent↗
PubMed1992

[Molecular biological study of the rhodopsin gene in Japanese patients with autosomal dominant retinitis pigmentosa].

The author analyzed codon 347 of the rhodopsin gene using PCR (polymerase chain reaction) amplification and restriction enzymes in 19 unrelated Japanese families including 28 patients with autosomal dominant retinitis pigmentosa (ADRP). An allele of codon 347 mutation was found in a family (father and daughter). Sequence analysis shows that the mutation is from CCG to CTG. This mutation appears to be the cause of one form of ADRP, since it was also found in Japanese cases of ADRP which have a different racial background from families reported by Dryja et al.

Codon↗
PubMed1992

[Unilateral vitreous hemorrhage secondary to massive subretinal hemorrhage in 5 cases].

Massive subretinal and vitreous hemorrhage (MSVH) in the elderly is usually complicated with senile disciform macular degeneration (SDMD). The authors treated 5 cases, averaging 59 years old, with MSVH in unilateral eye. They noticed sudden loss of vision and underwent vitreous surgery. After operation, organized hematomas were seen beneath the retina, which disappeared without scar formation, leaving atrophic lesions of the RPE and neural retina. The final visual outcome was NLP to 0.8, depending upon the location of subretinal hemorrhage. Fluorescein angiography demonstrated no subretinal neovascularization. Contralateral eyes showed no sign of SDMD during follow-up period of up to 6.5 years. These cases may suggest a pathogenesis different from the hemorrhagic type of SDMD.

Aged↗
PubMed1992

[The immunosuppressive acidic protein in the vitreous of fundus diseases].

Immunosuppressive acidic protein (IAP) is known to be a useful marker for malignant tumors and inflammatory diseases. We have previously reported that serum IAP level was increased in cases of Behçet's disease, especially in the acute phase, and those of retinoblastoma with extraocular infiltration. We assayed IAP levels in the vitreous body of various ocular diseases, including five cases of proliferative vitreoretinopathy (PVR), five cases of vitreous hemorrhage including four cases of branch retinal vein occlusion (BRVO) and one case of Terson's syndrome, four cases of proliferative diabetic retinopathy (PDR) and five cases of acute retinal necrosis syndrome. The single radial immunodiffusion method was used. The vitreous IAP level ranged from 5 to 130 micrograms/ml according to each case. Statistical analysis revealed that the vitreous IAP level was significantly higher in the group of PDR (p less than 0.05) and in the group of acute retinal necrosis syndrome (p less than 0.01) compared to the group of vitreous hemorrhage. In all cases, serum IAP levels were within normal limits. These results suggested that IAP might be produced within the ocular tissue, possibly by the activation of suppressor macrophages and migration of polymorphonuclear leukocytes in the vitreous with pathologic condition.

Adult↗
PubMed1992

Clinical features of Japanese family with autosomal dominant retinitis pigmentosa caused by point mutation in codon 347 of rhodopsin gene.

Four members in a Japanese family had autosomal dominant retinitis pigmentosa caused by a single point mutation in codon 347 of the rhodopsin gene. The youngest, an 11-year-old girl, had an abnormal electroretinographic response, although her fundus appeared normal. The other affected family members noticed night blindness in the second decade. Their fundi showed diffuse pigmentation with concentric visual field loss, and there was no recordable electroretinographic response. Cataract developed in the fourth decade in the older patients. Good visual acuity was retained however, even in the fifth decade, after cataract extraction. These clinical features were similar to those of American patients (European family origin) with the same mutation of the rhodopsin gene reported previously.

Adult↗
PubMed1992

Partially deficient glutamate dehydrogenase activity and attenuated oscillatory potentials in patients with spinocerebellar degeneration.

Glutamate dehydrogenase (GDH, EC 1.4.1.2) catalyzes the synthesis and degradation of glutamate, an excitatory neurotransmitter in the retina. Recently, two forms of GDH, a soluble heat-stable form and a particulate heat-labile form, have been demonstrated to be deficient in some types of spinocerebellar degeneration (SCD). We measured these forms of GDH activity in leukocyte homogenate from patients with SCD (n = 22) and normal subjects (n = 20) who were examined ophthalmoscopically and electrophysiologically. Seven patients with SCD showed attenuated oscillatory potentials (OPs) on electroretinography. The heat-labile GDH activity in these seven patients (78 +/- 51 nmol/mg protein/h) was significantly lower than that of 15 patients with normal OPs (367 +/- 189) and the normal subjects (397 +/- 1720 (P less than 0.001). Our results indicated that patients with SCD could be separated into two groups electrophysiologically, one with normal OPs and one with attenuated OPs. Also indicated was that a deficiency of heat-labile GDH might affect some functions of neural elements in the retina that are responsible for the generation of OPs.

Aged↗
PubMed1991

Augmentation of cytotoxic activity by combination with interleukin 2 and interferon gamma.

The synergy of cytotoxic activity by interleukin 2 (IL-2) and interferon gamma (IFN-gamma) was evaluated in human peripheral blood mononuclear cells (PBMC) and spleen cells. PBMC incubated with IL-2 (10 IU/ml) and IFN-gamma (200 IU/ml) for 4 days showed the stronger cytotoxic activity against K562, MOLT-4 and Daudi cells. Combination with IL-2 and IFN-gamma induced stronger activity than IL-2 or IFN-gamma alone. In order to investigate the sequential roles of IL-2 and IFN-gamma in the killer cell function, the cells were stimulated with IFN-gamma after washing of IL-2 or stimulated by IFN-gamma at various timing and duration without washing of IL-2. IL-2 was essential to induce the synergistic effect of IL-2 and IFN-gamma to cytotoxic activity. The similar augmentation of cytotoxic activity was observed by the addition of IFN-gamma at any incubation periods with IL-2, compared with stimulation with IL-2 or IFN-gamma alone. The phenotypes of the killer cells by stimulation with IL-2, IFN-gamma alone or IL-2 plus IFN-gamma were mainly CD2+, CD16+, indicating the activated natural killer cells.

Cytotoxicity, Immunologic↗
PubMed1991

Purification of retinol dehydrogenase from bovine retinal rod outer segments.

We purified retinol dehydrogenase from bovine rod outer segments using polyethylene glycol precipitation and hydroxylapatite, concanavalin A-Sepharose CL-4B, and Sepharose CL-6B column chromatography in the presence of NADP. We obtained 13-fold purification of retinol dehydrogenase with specific activity of 61.8 nmol/min/mg and 3.8% recovery. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that retinol dehydrogenase had a molecular mass of 37,000 daltons. The Km values of purified retinol dehydrogenase for all-trans retinol and all-trans retinal were 6.6 mM and 0.085 mM, respectively. The purified enzyme reacted with the all-trans retinal but not with 13-, 11-, and 9-cis compounds. In addition, we prepared antibody to retinol dehydrogenase using rat. The anti-retinol dehydrogenase antibody precipitated retinol dehydrogenase activity and was confirmed to bind to 37-kDa protein by Western blotting. We also found that anti-retinol dehydrogenase antibody bound to bovine rod outer segments specifically by immunohistochemical technique. The molar ratio of retinol dehydrogenase to opsin in rod outer segments estimated by enzyme-linked immunosorbent assay was 1:140.

Alcohol Oxidoreductases↗
PubMed1991

Pulmonary venous flow velocity pattern as assessed with transthoracic pulsed Doppler echocardiography in subjects without cardiac disease.

Pulmonary venous flow velocity pattern (PVFVP) was analyzed in 53 subjects (aged 25 to 77 years, mean 47) without cardiovascular disease who underwent transthoracic pulsed Doppler echocardiography. The forward flow velocity pattern was biphasic in 37 of the 53 subjects, with each of the 2 peaks in systole and diastole; flow was triphasic with 2 peaks in systole and the other peak in diastole in the remaining 16 subjects. Peak systolic and diastolic flow velocity ranged from 28 to 84 cm/s and from 27 to 71 cm/s, respectively. Mean systolic flow velocity was significantly greater than mean diastolic flow velocity (53 +/- 12 vs 47 +/- 11 cm/s, p less than 0.01). Systolic flow velocity and the ratio of systolic to diastolic flow velocity increased and diastolic flow velocity decreased with aging (r = 0.52, p less than 0.001, r = 0.70, p less than 0.001 and r = -0.49, p less than 0.001, respectively). Reverse flow occurred during the atrial contraction phase and its velocity (mean 20 cm/s) increased with aging (r = 0.56, p less than 0.001). The parameters of PVFVP were compared with the ratio of peak early diastolic filling velocity to peak filling velocity at atrial contraction (E/A ratio) measured in the transmitral flow velocity pattern. As E/A ratio increased, systolic flow velocity and systolic/diastolic flow ratio and peak reverse flow velocity decreased (r = -0.40, p less than 0.01, r = -0.67, p less than 0.001 and r = -0.68, p less than 0.001, respectively) and diastolic flow velocity increased (r = 0.58, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Nasobiliary drainage for spontaneous bile peritonitis due to cholangiocarcinoma].

We report a case of cholangiocarcinoma presented with bile peritonitis, in which endoscopic nasobiliary drainage (ENBD) as well as pleural and abdominal drainages improved the general condition leading to a radical operation. The case was a 79-year-old woman with the chief complaints of fever and right hypochondralgia due to pleural effusion and infected ascites contaminated with bile including E. coli. However gall-stones were not recognized in any biliary trees. US-guided drainage was performed into the pleural and abdominal cavities because of poor condition. After continuous drainages, peritonitis was improved, but hematoemesis and tarry stool appeared. Emergent endoscopy revealed a multiple gastric ulcer, and the bleeding was stopped by an injection of ethanol. ERCP findings revealed a cholangiocarcinoma in superior and middle portion of the bile duct obstructed nearly completely. After improvement in general condition by ENBD, cholecystectomy, resection of extrahepatic bile duct and subtotal gastrectomy were performed followed the reconstruction with Roux-en-Y method. Postoperative course was uneventful and the patient was discharged at the postoperative 35th day. Thus, the appropriate and opportune multiple biliary drainages can save a patient with cholangiocarcinoma in poor condition and lead to tolerate the operation even if he or she is suffering from severe bile peritonitis.

Adenoma, Bile Duct↗
PubMed1991

Novel epoxysuccinyl peptides. Selective inhibitors of cathepsin B, in vitro.

A series of new epoxysuccinyl peptides were designed and synthesized to develop a specific inhibitor of cathepsin B. Of these compounds, N-(L-3-trans-ethoxycarbonyloxirane-2-carbonyl)-L-isoleucyl-L-proli ne (compound CA-030) and N-(L-3-trans-propylcarbamoyloxirane-2-carbonyl)-L-isoleucyl-L-prol ine (compound CA-074) were the most potent and specific inhibitors of cathepsin B in vitro. The carboxyl group of proline and the ethyl ester group or the n-propylamide group in the oxirane ring were necessary, the ethyl ester group or the n-propylamide group being particularly effective for distinguishing cathepsin B from other cysteine proteinases such as cathepsins L and H, and calpains.

Animals↗
PubMed1991

Novel epoxysuccinyl peptides. A selective inhibitor of cathepsin B, in vivo.

New derivatives of E-64 (compound CA-030 and CA-074) were tested in vitro and in vivo for selective inhibition of cathepsin B. They exhibited 10,000-30,000 times greater inhibitory effects on purified rat cathepsin B than on cathepsin H and L: their initial Ki values for cathepsin B were about 2-5 nM, like that of E-64-c, whereas their initial Ki values for cathepsins H and L were about 40 200 microM. In in vivo conditions, such as intraperitoneal injection of compound CA-030 or CA-074 into rats, compound CA-074 is an especially potent selective inhibitor of cathepsin B, whereas compound CA-030 does not show selectivity for cathepsin B, although both compounds CA-030 and CA-074 show complete selectivity for cathepsin B in vitro.

Animals↗
PubMed1991

Histiocytic neoplasias: immunohistochemical evaluation of their frequencies among malignant lymphoma and related conditions in Japan.

Through histologic review of 1,766 cases with malignant lymphoma and related conditions, 35 cases (2%) were selected as probable histiocytic neoplasias. Proliferating cells in these cases had voluminous, granulated cytoplasm, and round to irregularly shaped nuclei often with bi- or multinucleated forms showing monomorphous or polymorphous proliferation accompanying small lymphocytes, plasma cells, and, less frequently, eosinophils. Cases showing proliferation of convoluted cells with numerous benign-appearing histiocytes or large cells with clear cytoplasm were excluded under a diagnosis of T-cell lymphoma. To evaluate the immunologic character of proliferating cells, immunohistochemistry using antibodies Mx-Pan B, MB-1, MT-1, UCHL-1, lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, S-100 alpha, S-100 beta, Leu M1, epithelial membrane antigen, and Ki-1 were carried out in 23 cases. Naphthol-ASD-chloracetate reaction and toluidine blue stain were also performed. These procedures revealed that 12 cases (52%) were B-cell type, three cases (13%) T-cell type, six cases (26%) true histiocytic type, and two cases null type. Therefore, the frequency of cases with true histiocytic neoplasias among cases with malignant lymphoma and related conditions in Japan may be 0.5%.

Antibodies, Monoclonal↗
PubMed1991

Chemosensitivity testing with highly purified fresh human tumour cells with the MTT colorimetric assay.

A major problem associated with the succinate dehydrogenase inhibition (SDI) test using tetrazolium dye (MTT) as a cancer chemosensitivity testing is the contamination of non-malignant cells in the tumour tissues. Highly purified fresh human tumour cells from 44 solid tumours and 24 malignant ascites were used for the MTT assay. The purity of tumour cells was greater than 90% after separation on Ficoll-Hypaque and Percoll discontinuous gradients. The OD570 obtained from tumour cells alone was higher than that from non-malignant cells. The chemosensitivity of tumour cells was distinct from that of non-malignant cells. Moreover, the chemosensitivity of highly purified tumour cells was also distinct from that of non-purified cells just separated from tumour tissues. 31 of the 68 patients had evaluable lesions, and received cancer chemotherapy according to the results of MTT assay using highly purified tumour cells. A clinical response was obtained in 10 of the 31 patients (response rate = 32.3%, 5 complete responses, 5 partial responses).

Adolescent↗
PubMed1991

Macular choroidal occlusion in dysplasminogenemia.

The authors describe a family with dysplasminogenemia. This diagnosis was based on a lowered ratio of functional plasminogen activity to immunologic plasminogen antigen level, associated with fundus abnormalities. The proband is a 31-year-old woman with Graves disease who had choroidal occlusive lesions of the macula in both eyes. The results of the laboratory examination indicated that the patient was a homozygote for dysplasminogenemia. Similar examinations of the patient's parents and siblings showed their plasminogen levels to be 50% below normal. The thrombotic tendency in this disorder appeared to be responsible for the pathogenesis of the macular choroidal occlusion.

Adult↗