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H Koga

Publications and source records attributed to H Koga.

At least 343 records · Page 19Linked to original sources
PubMed1990

Identification of 2Fe-2S cysteine ligands in putidaredoxin.

The iron-sulfur center of putidaredoxin is coordinated by four cysteine sulfhydrals. In order to determine which of the six cysteine residues in the protein coordinate the Fe-S center, we have individually mutated cysteine residues 73, 85 and 86 into serines. Of these mutant proteins, only C85S and C73S express holo-protein as evidence by SDS-PAGE and EPR spectroscopy. This leads us to the conclusion that residues 39,45,48, and 86 are the cysteines that coordinate the iron-sulfur center in putidaredoxin.

Base Sequence↗
PubMed1990

A patient with progressive myelopathy and antibodies to human T-cell leukemia virus type I and human immunodeficiency virus type 1 in serum and cerebrospinal fluid.

A 52-year-old human immunodeficiency virus type 1-seropositive bisexual black man was evaluated at UCLA because of the recent onset of progressive lower-extremity weakness. Initial neurologic examination showed that the patient's distal weakness was greater than his proximal weakness, with bilateral foot drop and electrophysiologic evidence of denervation in the distal lower extremities. Magnetic resonance imaging of the brain and spinal cord disclosed no abnormalities. Subsequent neurologic evaluation 8 months later showed a myelopathy, with progression of lower-extremity weakness, spasticity, and flexor spasms, and urinary incontinence, as well as the peripheral neuropathy noted previously. A second magnetic resonance imaging scan of the brain showed patchy foci of increased signal intensity in white matter and cortex, with mild generalized cerebral and cerebellar atrophy and no lesions in the spinal cord. Specimens of the patient's serum and cerebrospinal fluid contained antibodies to human immunodeficiency virus type 1. Additionally, specimens of his serum and cerebrospinal fluid were tested for antibody to human T-cell leukemia virus type I by Western blotting and radioimmunoprecipitation, and found to be positive for human T-cell leukemia virus type I gag, env, and tax antibodies. The primary cause of severe myelopathy in this patient may be infection with human T-cell leukemia virus type I rather than with human immunodeficiency virus type 1. Treatment with prednisolone resulted in improvement of the lower-extremity weakness, reduction in flexor spasms, and slower but significant improvement in urinary symptoms. Patients who are infected with human immunodeficiency virus type 1 and have unusual motor findings should be tested for concomitant human T-cell leukemia virus type I infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Mouse-human chimeric monoclonal antibody to carcinoembryonic antigen (CEA): in vitro and in vivo activities.

Mouse-human chimeric antibody specific for human carcinoembryonic antigen (CEA) was produced by recombinant DNA techniques. The genes of the mouse variable regions of heavy and light chains were cloned from the mouse hybridoma, 2.7.1G.10., which secreted anti human CEA antibody (IgG1, kappa), and were joined with human gamma 1 and kappa constant genes. The affinity of the resultant chimeric antibody to its relevant antigen was the same as that of the parental mouse monoclonal antibody when analysed by Scatchard plot analysis. The chimeric antibody showed a potent antibody dependent cell-mediated cytotoxicity (ADCC) activity with human peripheral blood mononuclear cells against CEA-positive human adenocarcinoma cells. In vivo imaging analysis revealed that the present chimeric antibody was specifically localized on the tumor site. These results indicate that our mouse-human chimeric antibody is a promising reagent for the diagnosis and therapy of CEA-positive human cancers.

Amino Acid Sequence↗
PubMed1990

Comparative study on specificities of rat cathepsin L and papain: amino acid differences at substrate-binding sites are involved in their specificities.

Sixty-nine rat cathepsin L-susceptible peptide bonds were analyzed employing various peptide substrates. The proteolytic specificities of rat cathepsin L and papain were compared and the results are discussed in relation to differences in amino acid residues around their binding sites. The specificity of cathepsin L, which is characterized by a remarkable preference for hydrophobic amino acids at the P2 site of the scissile peptide bonds, was analogous to that of papain as a whole. This analogous specificity suggests that the binding sites of the two proteases are analogous, as expected from their homologous amino acid sequences. However, there is a slight difference in the preference for S3 site between them. That is, cathepsin L showed a greater preference for bulky and hydrophobic amino acids at the S3 site than did papain. Based on the computer-graphically deduced structure of the binding sites of cathepsin L, the preferences for hydrophobic amino acids at the S2 site and for bulky and hydrophobic amino acids at the S3 site of the protease are supposed to be related to the compensating amino acid substitutions at the S2 site (V133A and V157L) and the reduction in size at the S3 site (Y61Q and Y67L), respectively. The discussion of the effect of the amino acid substitutions on the proteolytic activities of cathepsin L and papain in this paper provides a basis for more advanced studies of the relationship between structure and function of proteases belonging to the papain superfamily by means of protein engineering.

Amino Acid Sequence↗
PubMed1990

Studies on uricosuric diuretics. I. Syntheses and activities of xanthonyloxyacetic acids and dihydrofuroxanthone-2-carboxylic acids.

A series of substituted xanthonyloxyacetic acids (5 and 6), 1,2-dihydrofuro[2,3-c]xanthone-2-carboxylic acids (7) and 2,3-dihydrofuro[3,2-b]xanthone-2-carboxylic acids (8) were synthesized and tested for diuretic and uricosuric activities in rats. Most of the xanthon-3-yloxyacetic acids (5) and 7 showed potent diuretic activities, while 8 had lower activities. Uricosuric activities were found in 5c, 5f, 5k, 5m, 5o, 5p, 5r, 7m, 7p and 8q.

Animals↗
PubMed1990

Neutrophilia in bronchoalveolar lavage fluid of diffuse panbronchiolitis.

The clinical and pathologic features of diffuse panbronchiolitis (DPB) have been well reported to date, although its pathogenesis remains unknown. In the present study, we performed bronchoalveolar lavage (BAL) on three patients with biopsy specimen-proven DPB and eight patients with highly probable DPB (six women and five men; one smoker and ten nonsmokers), nine patients with chronic bronchitis (all men, five smokers and four nonsmokers), and nine normal control subjects (six women and three men, all nonsmokers) to clarify the cell populations in the lower respiratory tract. Neutrophils comprised 55.3 +/- 24.4 percent of recovered cells by BAL in DPB patients but only 6.6 +/- 6.4 percent in chronic bronchitis patients, and 1.8 +/- 1.5 percent in normal control subjects (p less than 0.001, all comparisons). The DPB patients also exhibited a decreased percentage of alveolar macrophages (34.9 +/- 23.5 percent) compared with chronic bronchitis patients and normal control subjects (p less than 0.001, all comparisons). The percentage of lymphocytes of the recovered lavage cells in DPB patients did not differ from that in chronic bronchitis patients and normal control subjects. These results indicate that neutrophils play an important role in the pathogenesis of DPB. They also suggest that neutrophilia of BAL-recovered fluid is a common finding in diseases associated with bronchiolar inflammation despite some clinical and pathophysiologic differences.

Adult↗
PubMed1990

Liposome-encapsulated amphotericin B in the treatment of experimental murine candidiasis.

The efficacy of liposome-encapsulated amphotericin B in treating experimental murine candidiasis was compared with that of the commercially available amphotericin B (Fungizone). The LD50 of liposomal amphotericin B in ddY mice exceeded 10.0 mg/kg while that of Fungizone was 3.0 mg/kg. Experimental candidiasis was induced by injecting a clinical isolate of Candida albicans strain 0925-107-01, through the tail vein. With the injection of 1.7 x 10(6) colony forming units, the number of colonies in the kidneys remained between 2.1 x 10(5) and 1.2 x 10(6), whereas the number of colonies in blood, liver, spleen, lungs and heart decreased rapidly. Histological examination revealed severe pyelonephritis with fungal infiltration and a mild invasion of the heart, lungs, liver and spleen. The survival rate of mice with experimental candidiasis treated with Fungizone at a dose of 0.8 mg/kg was 50% (the maximum tolerated dose without acute lethality), whereas all mice treated with the liposomal amphotericin B at a dose of 5.0 mg/kg were alive even 42 days after the inoculation (p less than 0.01). Using liposome as a carrier for amphotericin B decreased this drug's systemic toxicity making it possible to administer doses higher than feasible with the commercial preparation and thus obtaining better therapeutic efficacy.

Amphotericin B↗
PubMed1990

The influences of dexamethasone and indomethacin on 67Ga uptake by normal tissues.

Dexamethasone (DEX) increased 67Ga uptake by the liver and spleen at 4, 8, and even 24 h after the injection of 67Ga. These results showed that DEX influenced 67Ga accumulation as well as the initial entry of 67Ga in the liver and spleen. On the other hand, indomethacin (IM) decreased 67Ga uptake by the liver and spleen at 4 h after the injection of 67Ga but did not influence the uptake at 8 or 24 h after the injection of 67Ga. Moreover, DEX or IM little influenced 67Ga uptake by the kidney and muscle. These results suggest that the influence of DEX or IM on 67Ga uptake or accumulation is specific for the liver and spleen.

Animals↗
PubMed1990

Mutations in the p53 gene are frequent in primary, resected non-small cell lung cancer. Lung Cancer Study Group.

The p53 gene has been implicated as a tumor suppressor gene with mutations found in common human cancers. We examined 51 early stage, primary, resected non-small cell lung cancer specimens using an RNAase protection assay and cDNA sequencing. Mutations changing the p53 coding sequence were found in 23/51 (45%) tumor specimens, but not in the corresponding normal lung, were distributed between codons 132 to 283, and included tumors with and without 17p allele loss. Fifteen of the 23 mutations lay in the predicted binding regions for SV40 large T antigen, and 14 were located in regions highly conserved between species. G to T transversions were a common result of p53 mutations in lung cancer compared to other cancers suggesting exposure to different mutagens. In univariate and multivariate analysis the presence of p53 mutations was associated with younger age and squamous histology. However, the presence of p53 mutations was not significantly associated with tumor stage, nodal status or sex and was found in all histologic types of lung cancer. We conclude that somatic mutations in the p53 gene play an important role in the pathogenesis of early stage non-small cell lung cancer.

Aged↗
PubMed1990

[Modified microdiffusion method for fluoride analysis of foodstuffs].

In fluoride analysis, there are two procedures for the determination of fluoride depending on nature of samples. One procedure directly can determine fluoride contents by fluoride ion electrode, dissociating fluoride from the sample with the acid (perchloric acid). The other procedure needs to separate fluoride from biological sample using steam-distillation or micro-diffusion method, and then the determination by means of fluoride ion electrode can be applied. In this study, we applied a modified microdiffusion method by Hinoide (1990) for its availability in different temperatures and reaction time, and then estimated to determine fluoride contents of Shrimp (Sakura-shrimp) as a biological sample by this method. It is also very important to determine fluoride contents of foodstuffs and biological samples with regard to bioavailability of fluoride in vivo. The results were as follows: 1. Using the modified microdiffusion method, the fluoride recovery rate attained more than 95% in the range of 0.1-10 micrograms fluoride from a standard solution under the experimental condition of 60 degrees C and 90 degrees C of reaction temperatures and 60, 90 and 120 minutes of reaction time. 2. For the sample of shrimp, fluoride contents analyzed by means of the modified micro-diffusion and steam-distillation methods showed almost similar values, although the fluoride contents by steam-distillation method revealed relatively lower value. The difference might be derived from a loss of fluoride in ashing the sample before applying the steam-distillation method. The modified microdiffusion method used in this experiment can be utilized routinely and precisely in fluoride analysis for small amounts of biological sample.

Animals↗
PubMed1990

Frequent amplification of the bcl-1 locus in poorly differentiated squamous cell carcinoma of the lung. The Lung Cancer Study Group.

The bcl-1 locus on chromosome 11 at band q13 has been shown to be rearranged in some chronic B lymphoid malignancies with the t(11;14)(q13;q32). Chromosome 11 abnormalities occur in solid tumors including squamous cell cancers and adenocarcinomas. We have recently reported the frequency amplification of the bcl-1 locus in squamous cell carcinomas of head and neck origin, and increased copy number also has been found in some breast adenocarcinomas. In this investigation, we analyzed the arrangement, copy number and expression of this locus in 111 primary non-small cell lung cancers. Bcl-1 was found to be amplified three- to 10-fold in seven fresh tumors. Whereas none of 51 adenocarcinomas showed bcl-1 amplification, six of 46 squamous cell carcinomas revealed an increase in bcl-1 copy number. This amplification was more frequently associated with larger and more poorly differentiated tumors. None of the cancers showed rearrangement of this locus.

Adenocarcinoma↗
PubMed1990

[A case of foreign-body granuloma].

A 24-year-old male patient was admitted to our Ryukyu University Hospital, complaining of visual disturbance. He had had partial removal of a suprasellar region tumor in another hospital one year before the admission. Microscopical findings had shown two cell patterns of germinoma in the first operation. Following it, the patient received irradiation with a total dose of 54Gy. The tumor completely disappeared after these procedures. On this admission, plain CT scan revealed an isodensity mass in the suprasellar cistern extending to the right side of the third ventricle, which was enhanced homogeneously. In MRI, the mass showed low intensity in the T1-weighted inversion recovery sequence, and heterogeneously, high intensity in the T2-weighted spin echo sequence. By bifrontal craniotomy, the tumor was removed. Histologically, it consisted of granuloma containing fine cotton fibers. MRI findings of intracranial foreign-body granuloma were discussed.

Adult↗
PubMed1990

[Computed tomographic analyses on skeletal muscles in bulbar spinal muscular atrophy].

We analysed the patterns of skeletal muscular involvement in 18 patients with bulbar-spinal muscular atrophy (BSMA) of the Kennedy-Alter-Sung type by using the computed tomographic scanner. Fatty infiltrations were prominent in various skeletal muscles of extremities and trunk, and its degree was severe in the following numerical orders; the gluteal muscles, flexors of the thighs, flexors of the lower extremities, extensors and the adductors of the thighs, the paraspinal muscles, and extensors of the lower extremities. There was statistically significant correlation between fatty infiltrations in flexors of the lower extremities and duration of illness. And were noted findings that the skeletal muscle lesion progressed with the preserved fasciae and sectional areas, fatty infiltrations in the lower extremities were more conspicuous in flexors than in extensors, and compensatory hypertrophic muscles in the thigh were apparent in 50% of cases. In conclusions, the computed tomographic analyses on skeletal muscle of BSMA may be useful to detect distributions, progression of the muscle lesion, in addition to a profile of the myopathic alterations of the disease.

Adult↗
PubMed1990

[Cephem].

Explore the source record for details and available documents.

Bacteria↗
PubMed1990

[Computed tomography of skeletal muscles in myotonic muscular dystrophy].

The computed tomography (CT) of skeletal muscles was performed on 12 patients with myotonic muscular dystrophy (MyD). We have sliced at seven levels; those are 1. neck level-at the level of thyroid cartilage 2. shoulder girdle level-at the level of upper edge of sternum 3. upper arm level-at the level of middle of upper arm 4. abdominal level-at the level of L3 vertebra 5. pelvic girdle level-at the level of middle inguinal ligament 6. thigh level-at the level of middle of thigh 7. lower leg level-at the maximum size level of lower leg. The characteristic changes of MyD are; the sternocleidomastoid muscles are most severely affected, and the paravertebral and straight abdominal muscles also tend to be severely atrophied with lower CT density. Concerning thigh levels, the deeply located muscles and muscles for extension are predominantly affected. At the lower leg levels, the calf muscles are severely affected. The muscles of levator scapulae, trapezius, psoas major, iliopsoas, gluteus, and tibialis posterior tend to be preserved. In the tight, the compensatory hypertrophy is observed often in the rectus femoris muscles and rarely in the gracilis muscles with the involvements of the agonist muscles. It might be also important to examine the changes of muscles as a whole and to know the grade of atrophy for planning the life style. The CT examination would be recommended by this standpoint.

Adult↗
PubMed1990

Mechanism of uricosuric action of AA-193 in DBA/2N mice.

Six strains of mice were investigated to find an animal model suitable for researching the mechanism of uricosuric agents. A clearance method and a pyrazinamide suppression test were used to examine the mechanism of urate excretion in the kidney and the mode of action of uricosurics, respectively. The negative correlation between the urinary urate excretion and the endogenous plasma urate level was observed, suggesting the net reabsorption of urate may vary between strains. DBA/2N mice showed the lowest fractional excretion of urate (0.278), and the effects of uricosurics on DBA/2N mice are analogous to those of humans. Our extensive study of the mechanism of urate excretion in DBA/2N mice has proven that the mouse strain is a useful model for the study of uricosurics. AA-193 (5-chloro-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carb oxylic acid) is a potent new uricosuric agent developed in our laboratory. In the present study, AA-193 was tested in DBA/2N mice and found to have a mode of action different from well-known uricosuric agents. It appeared to inhibit presecretory reabsorption in the proximal tubules.

Animals↗
PubMed1989

The activity of AA-193, a new uricosuric agent, in animals.

A new uricosuric agent, 5-chloro-7,8-dihydro-3-phenylfuro[2,3-g]-1,2-benzisoxazole-7-carbo xylic acid (AA-193), was compared with other uricosurics in the rat, mouse and cebus monkey. In rats, probenecid and tienilic acid increased the urate excretion, but benzbromarone did not have the uricosuric activity. Thus, the presecretory reabsorption of urate is probably dominant in rats. We found that in rats AA-193 was the most potent uricosuric tested. In mice, probenecid not only had so-called paradoxical actions but stimulated urinary urate wasting after administration of pyrazinamide. These data suggest that the renal transport system of urate in the mouse is similar to that in man. AA-193 as well as benzbromarone enhanced the urate excretion dose-dependently, but the effects were different in pyrazinamide suppression tests in mice. In cebus monkeys, the uricosuric and hypouricemic effects of AA-193 were more potent than those of probenecid and similar to those of tienilic acid, but less than those of benzbromarone. Benzbromarone had a considerable role in postsecretory reabsorption in the monkey. These results suggest that AA-193 is a new class of uricosuric agent that controls the renal reabsorption of filtered urate particularly.

Animals↗