Biomedical subjects

T Okabe

Publications and source records attributed to T Okabe.

At least 199 records · Page 11Linked to original sources

PubMed1994

Purification and characterization of endothelin-1 degradation activity from porcine kidney.

In order to identify the membrane-bound peptidase that is responsible for the degradation of endothelin (ET), an endothelin-1 (ET-1) degradation enzyme was solubilized from membrane fractions of porcine kidney with 1% Triton X-100, and subsequently purified by column chromatographies, i.e., diethylamino-Sepharose ion exchange, gel permeation, Con A Sepharose and hydroxyapatite chromatography. On DEAE-Toyopearl ion exchange column chromatography, the ET degradation enzyme and aminopeptidase were separated, but ET degradation enkephalinase activities were not separable. In order to separate ET degradation enzyme and enkephalinase, the active fractions were loaded on each of the column chromatographies: sephacryl S-200, Con A Sepharose or hydroxyapatite. The ET degradation activities were co-migrated with enkephalinase activities on all of the three chromatographies. In addition, the ET degradation activities were inhibited by thiorphan, phosphoramidon and EDTA, which are known to inhibit enkephalinase. These results suggest that ET degradation activity in the membrane fractions of the kidney is related to enkephalinase and may be involved in the degradation of ET-1 in vivo.

Aminopeptidases↗

PubMed1994

Local pathological reactions induced in pigs and cats by adjuvant ISA-70 containing inactivated Newcastle disease virus antigen.

Gross and microscopic changes at the injection site in pigs and cats were investigated for 8 weeks after an intramuscular injection of oil adjuvant ISA-70 emulsion, containing inactivated Newcastle disease virus antigen. In pigs, an egg-sized and discolored lesion with pinpoint to miliary-sized nodules was observed at 2 to 8 weeks post injection (PI). In cats, there was partial thickening of the subcutaneous tissue at 2 to 8 weeks PI. Histopathologic changes in pigs were fundamentally similar to those in cats, however, the local tissue reactions in pigs were severer and more protracted than those in cats. The lesions in pigs were characterized by formation of large-sized cysts and well-developed encapsulation of the cysts with epithelioid cells.

Adjuvants, Immunologic↗

PubMed1994

Single amino acid substitution (840Arg-->His) in the hormone-binding domain of the androgen receptor leads to incomplete androgen insensitivity syndrome associated with a thermolabile androgen receptor.

We have characterized the androgen receptor in a Japanese girl and her maternal cousin in a family with incomplete androgen insensitivity syndrome, and have investigated the molecular basis. Whole-cell androgen binding assay in cultured genital skin fibroblasts from both patients showed a normal maximum binding capacity and a normal apparent dissociation constant. However, androgen binding in fibroblasts from both patients decreased to 30% when the assay temperature was raised from 30 degrees C to 41 degrees C, indicating the presence of the thermolability of ligand binding to the androgen receptor. Sequence analysis of the coding exons of the androgen receptor gene from the patients revealed a single nucleotide substitution at position 2881 in exon G, resulting in the conversion of arginine (CGT) to histidine (CAT) at amino acid position 840 in the hormone-binding domain of the androgen receptor. The family study showed that the mothers and the maternal grandmother of the patients are heterozygous carriers for this mutation, whereas the father does not carry it, supporting the view that androgen insensitivity syndrome is an X chromosome-linked disorder. The single amino acid substitution may explain the qualitative abnormality of the androgen receptor displaying thermolability, which is thought to be the pathogenesis of incomplete androgen insensitivity syndrome in the patients.

Androgen-Insensitivity Syndrome↗

PubMed1994

[Analysis of computed X-ray tomography of the brain in incontinence patients with senile dementia. Relationship between circulatory defect of the brain, brain atrophy and urinary incontinence].

To evaluate the condition of incontinence in patients with senile dementia, we performed computed tomography X-rays to the brain and analyzed the relationship among the circulatory defect of the brain, the brain atrophy and the degree of incontinence. There were 92 patients subjected to this study who were hospitalised due to senile dementia; 74 patients had vascular dementia, 10 patients had senile dementia of Alzheimer type, and 8 patients had the mixed type. (age ranged: 54-95 years; mean: 80.3 years). The degree of incontinence in these patients varied as follows: 18 patients with continence, 16 patients with moderate incontinence, 58 patients with total incontinence. The diagnosis of circulatory defect of the brain was based on computed tomography observation of periventricular lucency (P.V.L.), and the degree of brain atrophy was evaluated based on 4 criteria: the Lateral body ratio, the Huckman number, the Evans ratio, and the enlargement of the subarachnoid space. Among the 92 patients, P.V.L. was present in 31 patients, among them 27 patients suffered from incontinence. There was a significant correlation between P.V.L. and incontinence (p < 0.001). As the incontinence progressively worsened (Continence, Moderate incontinence Total incontinence), the lateral body ratio increased to 24.8, 27.8, 28.6, (p < 0.05). The Huckman number also increased to 18.3, 19.3, 21.3, (p < 0.01), and the evans ratio likewise 29.9, 32.3, 33.7 (p < 0.01). The enlargement of the subarachnoid space was also correlated with the severity of incontinence. We conclude that urinary incontinence originating from senile dementia is connected to brain atrophy and is strongly influenced by the circulatory disorders of the brain.

Aged↗

PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. I. Producing organism, fermentation, isolation and biological activities.

BE-23372M, a novel protein tyrosine kinase inhibitor, was isolated from the culture broth of a fungus. The producing strain, F23372, was identified as Rhizoctonia solani, based on the cultural and morphological characteristics. The active principle was extracted from the mycelium with acetone and purified by solvent extraction, silica gel column chromatography and Sephadex LH-20 column chromatography. BE-23372M showed strong inhibitory activity against EGF receptor kinase with IC50 values of 0.02 and 0.03 microM on two different substrates, whereas IC50 values against protein kinase C and cAMP-dependent protein kinase were 4.5 and > 20 microM, respectively. The compound inhibited the growth of A431 human epidermoid carcinoma and MKN-7 human stomach cancer cell lines with IC50 values of 8 and 24 microM, respectively.

Amino Acid Sequence↗

PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. II. Physico-chemical properties and structure elucidation.

BE-23372M, a new protein tyrosine kinase inhibitor, has been obtained as a reddish orange solid. The compound, C17H12O6, HRFAB-MS: m/z 312.0625 (M)+, is an acidic substance, showing UV (MeOH) lambda max (epsilon) 266 (8,800), 426 nm (20,400), and IR (KBr)vmax 1752(C = O) and 3298(OH) cm-1. The structure of BE-23372M, (E)-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-fur anone, has been elucidated by 1H and 13C NMR studies.

Chromatography, Thin Layer↗

PubMed1994

BE-23372M, a novel protein tyrosine kinase inhibitor. III. Synthesis.

In a preceding paper, the physico-chemical properties and structural elucidation of BE-23372M, a potent novel protein tyrosine kinase inhibitor, were described. In this paper, we report the synthesis of BE-23372M from 3-(3,4-dimethoxybenzoyl)propionic acid and veratraldehyde or 3,4-diacetoxy-benzaldehyde. The structure of BE-23372M was confirmed to be (E)-3-(3,4-dihydroxybenzylidene)-5-(3,4-dihydroxyphenyl)-2(3H)-fur anone.

Furans↗

PubMed1994

[A case of miliary tuberculosis with high-grade fever that remitted without antituberculosis therapy].

A 23-year-old man was admitted with a persistent high-grade fever of 20 days duration. Chest roentgenogram showed diffuse miliary shadows in both lung fields, highly suggestive of miliary tuberculosis. Sputum, gastric juice, and bronchoalveolar lavage fluid did not, however, reveal acid-fast bacilli on smears. A bone marrow aspirate and a transbronchial lung biopsy were also negative for caseating granulomas and tubercule bacilli. After admission, the high-grade fever remitted in several days without continuous antibiotic, antituberculosis or antipyretic therapy. Levels of inflammatory markers (CRP, ESR, alpha 2-globulin dropped simultaneously. Despite the atypical clinical course, miliary tuberculosis was suspected. We therefore carried out an open lung biopsy. The presence of caseating granulomas and acid-fast bacilli confirmed the diagnosis of miliary tuberculosis. The remission of miliary tuberculosis without treatment is very rare and the details of this case are presented herein with a discussion of the pertinent literature.

Adult↗

PubMed1994

Sensitization to cockroach allergens of asthma patients in Japan.

To evaluate the role of allergens from Periplaneta fuliginosa, which is the most predominant cockroach species in homes in Tokyo areas, for asthma sensitization, we measured specific IgE antibodies to two cockroaches, P. fuliginosa and Blattella germanica, and to a mite, Dermatophagoides farinae, in 171 sera from children with asthma by Pharmacia's CAP system. We found that 16% of the sera had anti-P. fuliginosa IgE, whereas 9.9% had anti-B. germanica and 85% anti-D. farinae IgE. Further, we measured the levels of Per f I (Per a I equivalent) allergen in the house dust from living room, kitchen and bedding. We detected the allergen in eight of ten homes. The Per a I equivalent levels in kitchen were higher than in other sites, but they were much lower than Der I and Der II as Dermatophagoides allergens.

Allergens↗

PubMed1994

[A Japanese pedigree with oculopharyngeal muscular dystrophy].

We investigated a Japanese pedigree with oculopharyngeal muscular dystrophy (OPMD) which included the probands of two sisters and a brother. Case 1 (Fig. 1): A woman born in 1940 at Fuji City, Shizuoka prefecture (Pacific coast side, which located about 80 miles west from Tokyo) was insidiously suffering from dysphagia and eye lid ptosis since her age of 40. She was admitted to Shizuoka Red Cross Hospital when 48 years old, because of difficulty of going upstairs. Neurological examination revealed severe eye lid ptosis without eye movement disorders, dysphagia, and moderate weakness on neck and proximal muscles of extremities without definite atrophy and fasciculation. In the laboratory data, serum creatine kinase level was slightly elevated to 215 U/l. Electromyographic findings showed myogenic pattern on the extremities but no evidence of the existence of myasthenia gravis and neurogenic involvement. Intranuclear tubular filaments were found in 3% of muscle fibers from her left biceps muscle. Case 2: The elder sister of the case 1 was suffering from eye lid ptosis without eye movement disorder and severe dysphagia since the age of 44. Case 3: The younger brother of the case 1 was suffering from dysphagia and proximal muscle weakness since the age of 40. We found eye lid ptosis, dysphagia and/or proximal muscle weakness in 24 cases (men: 12 cases, women: 12 cases) out of 50 examined members of this pedigree after their ages of 40 (Fig.3; family tree). It was concluded that this pedigree had cases of oculopharyngeal muscular dystrophy with autosomal dominant inheritance which was quite rare in Japanese.

Female↗

PubMed1994

[The usefulness of the bayesian method for the prediction of plasma theophylline levels in asthmatic children during RTC therapy by the sustained preparation of theophylline].

Pharmacokinetic prediction of plasma theophylline levels during RTC therapy by the sustained release preparation of theophylline was studied with a one compartment model in children aged 1-6 years old showing comparatively long sleeping time. Using the parameters measured from the population of 1-17 year olds, the accuracy of the prediction was studied by the Bayesian method. Absolute error (A.E.) and estimation error (E.E.) were about 2.0. The prediction values of E.E. seemed to be rather higher if the measured values of the absorption phase were used, and the values seemed to be rather lower if the values of the elimination phase were used. From these results it might be concluded that the Bayesian method seems to be useful for RTC therapy in children under 6 years old.

Adolescent↗

PubMed1994

[Origin and cytogenetic abnormalities of sarcoid epithelioid cells].

The sarcoid epithelioid cells are believed to be a variant of tissue macrophages, which derived from circulating monocytes in blood. Formation of monocytes and macrophages are controlled by hematopoietic growth factors, i.e; colony-stimulating factors in the bone marrow. In the presence of colony-stimulating factors and/or vitamin D3, blood monocytes can proliferate and differentiate into epithelioid cells and multinucleated giant cells. In view of the evidences that sarcoid granulomas produce colony-stimulating factors and active form of vitamin D3, these results suggest that active metabolites of vitamin D3 and colony-stimulating factors produced by sarcoid epithelioid cells, induces the differentiation and proliferation of circulating monocytes into macrophage-epithelioid cells, which in turn form sarcoid granulomas. Since sarcoidosis is a disorder of cell proliferation and differentiation, a question has been always kept in my mind whether the sarcoid granulomas are chronic inflammation per se or neoplastic in nature. Interestingly, cytogenetic studies revealed that most of the epithelioid cells were aneuploid; the chromosomal number ranged from the near-haploid to the near diploid number. In addition, The distribution of DNA content of the granuloma cells was fairly wide. Our observations raise a question whether the aneuploidy in sarcoid granulomas may be due to viral infection or exposure to carcinogens as in the case of neoplastic cells. It is also possible to speculate that the aneuploidy may be a mechanism of macrophage differentiation similar to immunoglobulin gene rearrangement in B lymphocytes. Further studies are required.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneuploidy↗

PubMed1994

Reduction in operatory mercury levels after contamination or amalgam removal.

The threshold limit value (TLV) for occupational exposure to mercury can be exceeded in the dental operatory after a contamination event or during certain dental procedures. The objective of this study was to determine the time required for the mercury vapor levels to return to baseline in both non-ventilated and ventilated operatories after they had been contaminated with mercury to the TLV of 0.050 mg/m3; and to evaluate the efficiency of an activated charcoal filtering device for removing mercury vapor. The results showed that even in a poorly ventilated operatory, the mercury vapor level returned to background within 20-30 minutes after a contamination, and within 10-20 minutes when the operatory was ventilated. The filtering device reduced the level of mercury vapor by approximately 25% during a continuous contamination event, but did not clear the operatory faster than normal settling after a limited source contamination. The filter caused a significant reduction in mercury in the breathing zones of the patient and dentist during and after amalgam removal, but did not eliminate the exposure. This study demonstrated the difficulty in contaminating an operatory with mercury vapor and confirmed the limited time mercury remains airborne, presumably due to its density and affinity for surfaces.

Air Pollution, Indoor↗

PubMed1994

A cyclin-dependent kinase inhibitor, butyrolactone I, inhibits phosphorylation of RB protein and cell cycle progression.

Butyrolactone I is a selective inhibitor of the cyclin-dependent kinase (cdk) family. It inhibits both cdk2 and cdc2 kinase, but scarcely affects C-kinase, A-kinase, casein kinases, MAP kinase or EGF receptor-tyrosine kinase (Kitagawa et al., 1993, Oncogene, 8, 2425-2432). We studied the effects of butyrolactone I on the cell cycle as well as on phosphorylation of retinoblastoma protein (pRB). Butyrolactone I inhibited phosphorylation of pRB catalyzed by cyclin A-cdk2 produced by baculovirus in vitro. Furthermore, it inhibited phosphorylation of pRB and cell cycle progression from G1 to S phase in WI38 cell cultures. WI38 cells arrested at the G0 phase by serum starvation progressed in the cell cycle after serum stimulation. pRB was phosphorylated after 10 h serum stimulation. Incorporation of [3H]thymidine into the cells began to increase after 16 h serum stimulation. These processes were inhibited by butyrolactone I. Flow cytometric analysis showed that exposure to butyrolactone I inhibited progression of the cell cycle from G1 to S phase. These data suggested that initiation of DNA synthesis was inhibited by butyrolactone I and that the cell cycle was arrested in the G1 phase. Butyrolactone I also inhibited H1 histone phosphorylation in human WI38 cells and their G2/M progression. tsFT210 cells, a temperature-sensitive cdc2 mutant cell line, were synchronized at G2/M at a nonpermissive temperature, butyrolactone I inhibited the cell cycle progression of these cells at G2/M at the permissive temperature. Thus butyrolactone I, a cyclin-dependent kinase family inhibitor, which prevented the phosphorylations of the cell cycle-regulating proteins pRB and H1 histone, inhibited the cell cycle at G1/S and G2/M, respectively. These results suggest that the phosphorylations of pRB and H1 histone may play crucial roles in G1/S and G2/M progression, respectively, although it is possible that phosphorylations of other proteins by cdks are involved in G1/S and G2/M progression.

4-Butyrolactone↗

PubMed1993

Enhanced evaporation of mercury from amalgams in non-oxidizing environments.

The release of mercury from two freshly triturated amalgams exposed to a reducing atmosphere, hydrogen, was quantitated at three different temperatures. A low-copper and a high-copper amalgam were placed into a flowing hydrogen gas atmosphere for 60 min after trituration, and then the hydrogen was replaced by compressed air. The results were compared to those obtained in a previous study in which air and argon atmospheres were used under identical conditions. At 37 degrees C, the rate of evaporation of mercury from the amalgams was similar when they were exposed to hydrogen before being exposed to air. During exposure to hydrogen, the evaporation rate appeared to exceed the limit of the gold film mercury analyzer (284 pg/mm2/s), but was rapidly reduced upon exposure to air. The results were identical to those from argon exposure. When the same experiment was performed at 80 degrees C, the evaporation rate after hydrogen exposure was greater than that after exposure to argon, and far greater than that during exposure to air alone. Similar results were achieved at 110 degrees C, but there was less difference between hydrogen and argon exposure. The results support previous studies which show that the evaporation of mercury from amalgam is mainly limited by the formation of an oxide film.

Air↗

PubMed1993

In vitro stability of biphasic calcium phosphate ceramics.

Biphasic calcium phosphate ceramics consist of both beta-tricalcium phosphate and hydroxyapatite. This study was performed to examine the in vitro stability of biphasic calcium phosphate ceramics in deionized distilled water and in physiological solutions. Biphasic calcium phosphates of two different molar ratios and pure hydroxyapatite and pure beta-tricalcium phosphate granules were tested. X-ray diffraction data were obtained before and after immersion. Surface morphology was compared using scanning electron microscopy. The pure beta-tricalcium phosphate and the beta-tricalcium phosphate in the biphasic calcium phosphate ceramics gradually converted to apatite. Needle-like apatite crystals were observed on the surface of biphasic calcium phosphate and beta-tricalcium phosphate, but hydroxyapatite showed no change.

Biocompatible Materials↗

PubMed1993

Handling characteristics of gallium alloy for dental restoration.

The handling characteristics of a gallium alloy (Gallium Alloy GF) were compared to those of a spherical high-copper amalgam (Tytin). Ten dentists each restored four identical MO preparations in acrylic typodont teeth (no. 30), two with amalgam and two with gallium alloy. Each restoration was evaluated immediately following completion by the operator for six clinically relevant criteria. Each criterion was scored between 1 and 5, where 1 = very poor, 2 = poor, 3 = fair, 4 = good, and 5 = very good. Three two-sided Mann-Whitney tests were used to compare the median scores for significant differences (P < 0.05). The first test indicated no significant difference between scores for the first- and second-placed restorations, within criteria and within alloy type (n = 10). The second test indicated a significant difference between amalgam and gallium alloy, within criteria and within restoration sequence (n = 10), for each criterion except resistance to fracture during removal of the matrix band. The third test indicated a significant difference between amalgam and gallium alloy, within each criteria, combining scores for first- and second-placed restorations (n = 20). During simulated clinical placement, amalgam was rated significantly higher than gallium alloy in each handling characteristic evaluated.

Dental Alloys↗

PubMed1993

Effect of aggressive haemoperfusion on the clinical course of patients with paraquat poisoning.

The effect of aggressive haemoperfusion; i.e. haemoperfusion of 10 h or more during the first 24 h after ingestion, on the clinical course of paraquat poisoning was studied. Among 40 patients admitted within 15 h after ingestion of paraquat with an SIPP of less than 100 (h x micrograms ml-1), 21 received aggressive haemoperfusion and 19 received conventional haemoperfusion; i.e. haemoperfusion of less than 10 h during the same period. Survival rates of patients with severity between an SIPP of 100 and Proudfoot's curve in the two groups were compared by the log-rank test. Aggressive haemoperfusion did not improve the outcome but did improve the survival rates; that is, the number of patients surviving at particular points in time (P < 0.05). The length of haemoperfusion for the aggressive haemoperfusion group was longer than that for the conventional group on the first day (P < 0.001), but the difference was insignificant during the following two days. Neither the time from ingestion to haemoperfusion, urine volume from the first to third day, nor initial plasma-paraquat concentrations and SIPP were significant between groups. These findings imply that aggressive haemoperfusion reduces the severity of paraquat poisoning and elongates survival time. We, therefore, propose that the efficacy of more aggressive haemoperfusion, such as the 'continuous haemoperfusion' proposed by Okonek et al., should be further studied.

Adolescent↗