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Biomedical subjects

M Katoh

Publications and source records attributed to M Katoh.

At least 235 records · Page 13Linked to original sources
PubMed1994

Inhibition of histamine release from RBL-2H3 cells by protein synthesis inhibitors.

Effects of cycloheximide, an inhibitor of protein synthesis, on histamine release from RBL-2H3 cells were examined. RBL-2H3 cells sensitized by rat antiserum to ascaris extract were challenged by the antigen, and histamine release during a period of 30 min was measured. Pretreatment with cycloheximide (1 microgram/ml) for 1 h significantly inhibited the antigen-induced histamine release (36% inhibition). The cycloheximide-induced inhibition of histamine release was abolished when the cells were further incubated in the absence of cycloheximide for 2 h. Pretreatment with puromycin (3 and 10 micrograms/ml), an inhibitor of protein synthesis, or actinomycin D (0.1-1 microgram/ml), an inhibitor of DNA-dependent RNA synthesis, also inhibited the antigen-induced histamine release in a concentration-dependent manner. Both ionomycin- and thapsigargin-induced histamine release were also inhibited by pretreatment with cycloheximide. Measurement of intracellular Ca2+ levels using quin 2 revealed that cycloheximide inhibits the increase in Ca2+ levels induced by the antigen, ionomycin or thapsigargin. These results suggest that histamine release induced by the antigen, ionomycin and thapsigargin in RBL-2H3 cells is mediated by protein(s) which is newly synthesized and inactivated rapidly, and the newly synthesized protein(s) is involved in the increase of intracellular Ca2+ levels induced by these stimulants.

Animals↗
PubMed1994

Muscular dystrophy of the diaphragmatic muscles in Holstein-Friesian cows.

Six Holstein-Friesian cows suffering from recurrent rumenal tympany were pathologically investigated. Macroscopical lesions associated with the clinical symptoms were confined to the diaphragmatic muscles which were pale, and stiff on palpation. Histopathological examination revealed various degenerative changes in diaphragmatic muscles as follows: variation in muscle fiber diameter, vacuolar and hyalinized degeneration of muscle fibers, fiber splitting, central core-like structures, sarcoplasmic masses and ring fibers. These characteristic features in the present cases were consistent with dystrophy of the diaphragmatic muscles in Meuse-Rhine-Yssel cattle. From these observations, it is confirmed that muscular dystrophy of the diaphragmatic muscles dose occur in Holstein-Friesian cows, although a genetic mode was not proven.

Animals↗
PubMed1994

[VCAP chemotherapy combined with interferon-alpha (HLBI) for elderly multiple myeloma].

VCAP chemotherapy combined with natural interferon-alpha (HBLI) was performed on elderly patients over 65 year with multiple myeloma (MM), and its clinical effects were compared with those of VCAP chemotherapy without HLBI on elderly MM and also with those of HLBI-VCAP and VCAP combination therapy on non-elderly MM. Sixteen elderly and 21 non-elderly patients received HLBI-VCAP combination therapy, whereas 12 elderly and 21 non-elderly patients were treated with VCAP chemotherapy alone. The remission rate (CR+PR) was 81% for the elderly HLBI-VCAP group, 58% for the elderly VCAP group, 90% for the non-elderly HLBI-VCAP group, and 76% for the non-elderly VCAP group. While the median survival time was 54 months for the elderly HLBI-VCAP group and 13.5 months for the elderly VCAP group, it was 70 months for non-elderly HLBI-VCAP group and 34.5 months for the non-elderly VCAP group. The survival time in the elderly HLBI-VCAP group was significantly longer than that in the elderly VCAP group. Therefore, improvement of survival in cases treated by interferon was much better in the elderly group than in the non-elderly group. These results indicate that HLBI-VCAP combination therapy is beneficial for the treatment of elderly MM.

Aged↗
PubMed1994

[Refractory immune thrombocytopenic purpura accompanied with avascular necrosis of femoral head receiving the combination of high dose immunoglobulin therapy followed by platelet transfusion could successfully be managed to undergo surgery].

A 31 year-old male with refractory immune thrombocytopenic purpura (ITP) was accompanied with avascular necrosis of the femoral head on both sides, refractory to the following conventional therapies: high dose immunoglobulin (IgG) therapy, splenectomy, vinblastin slow infusion; maintaining a platelet count less than 20 x 10(3)/microliters. He subsequently tried the combination of high dose IgG therapy with platelet transfusion from two single donors, which successfully increased the platelet count to more than 50 x 10(3)/microliters for as long as 9 days. Compared to this method, platelet transfusion alone without IgG infusion failed to maintain an increase in the platelet count. These results suggest that high dose IgG may affect transfused-platelet removal in ITP. Management by the combination method enabled him to undergo surgery twice and he was able to walk with a stick six months later.

Adult↗
PubMed1994

[Temporal arteritis].

Temporal arteritis or giant cell arteritis occurs most commonly in elderly individuals. The lesion is usually restricted to the temporal arteries, but rarely, those elsewhere in the body may be involved. The symptoms include a pulsatile headache, usually in the temporal regions, together with anorexia, fever, jaw claudication and muscle pain, known as polymyalgia rheumatica. Histopathological study shows a granulomatous inflammatory lesion with mono-nuclear cell infiltration, associated with Langhans type giant cells, involving mainly the tunica media. Temporal arteritis is not considered to be a life-threatening disorder, however, visual disturbance, the most serious complication, may appear in those with affection of the ophthalmic artery, resulting in blindness in approximately 26% of the untreated cases. Therefore, early diagnosis by temporal artery biopsy and immediate steroid administration should be the keynote of successful therapy for preventing such a critical complication and for relief of the symptoms.

Drug Therapy, Combination↗
PubMed1994

[Surgical treatment of descending thoracic aortic aneurysm with simple aortic cross-clamping versus left heart bypass using centrifugal pump].

Surgical treatment has been employed in 52 patients (pts) with descending thoracic aortic aneurysm (DS-TAA). Based on the adjuncts during aneurysmal repair, the series is divided into 2 groups; simple aortic cross-clamping was utilized to manage the lesion in group SC (n = 42), while left heart bypass using a centrifugal pump was employed during the period of aortic occlusion in LHB group (n = 10). Of these 52 pts, 4 died in hospital (group SC:2, group LHB:2). The most common complication was the respiratory failure following the renal failure. No paraplegia occurred in both groups. Biochemistric measurements of alanine aminotransferase, creatinine (CRN) and amylase (AMY) showed no difference between group SC and group LHB. In pts of SC group with normal renal function, post-operative maximum (post Max) CRN during the first month had a logarithmic correlation with total aortic cross-clamp time (TAXT). The post Max CRN of LHB group with normal renal function remained less than 3.0 mg/dl even in the case with TAXT over 60 minutes. There is also a linear correlation of post Max AMY in pts of SC group. Late survival at 4 years, including hospital death, were 83% in SC group and 63% in LHB group. We conclude that DS-TAA cases with TAXT of less than 30 min with good distal organ function can be managed with simple aortic cross-clamping; otherwise usage of LHB was recommended to support distal circulation.

Adult↗
PubMed1994

[Local recurrence of ureteral tumor histologically similar to malignant lymphoma: a case report].

A 65-year old man, who had had resection of a right ureter tumor two years earlier, was hospitalized with complaints of lower abdominal discomfort and hematuria. Pathological diagnosis of the ureteral tumor was grade 3 transitional cell carcinoma. Computed tomography and magnetic resonance imaging demonstrated a large tumor in the retrovesical space and recurrence of transitional cell carcinoma was suggested. Total pelvic exenteration was performed and pathological diagnosis of the tumor was undifferentiated carcinoma simulating malignant lymphoma. Immunohistochemical examinations revealed no antigens specific for the lymphoid cells or epithelial cells on the specimen. This tumor consisting of undifferentiated carcinoma was considered to be recurrence of transitional cell carcinoma with the diffuse pattern simulating malignant lymphoma proposed by Zukerberg et al.

Aged↗
PubMed1994

[Relationship between prognosis of multiple myeloma and response to VCAP therapy].

We investigated the relationship between response in M-protein to VCAP therapy and survival duration in 50 multiple myeloma (MM) patients who survived for at least 6 months. The relationship between improvement of hemoglobin level as a response of VCAP therapy and survival duration was also assessed. The survival time in patients whose M-protein was reduced by 50% or more within 6 months after therapy was shorter than that in patients in whom the reduction of > or = 50% or more was obtained in more than 6 months. Patients with a hemoglobin level of 10 g/dl or higher before therapy survived significantly longer than those with a hemoglobin level of less than 10 g/dl. Among the patients with a hemoglobin level of less than 10 g/dl, patients in whom the hemoglobin level improved to 10 g/dl or higher survived for significantly longer duration than patients without improvement (p < 0.01). Patients in whom the hemoglobin level improved after more than 6 months survived form significantly longer duration than patients in whom hemoglobin level improved within 6 months. Therefore, it was considered that it was difficult to predict prognosis from the rate of decrease in M-protein in the early stage of treatment.

Aged↗
PubMed1994

[Infection-induced transient increase in the platelet count, and a transient remission of thrombocytopenia with high-dose intravenous gammaglobulin therapy during intercurrent pneumonia in chronic idiopathic thrombocytopenic purpura].

A patient with chronic idiopathic thrombocytopenic purpura (ITP), who had a transient increase in platelet count during infectious episodes, and had a transient remission of thrombocytopenia with administration of high-dose intravenous gammaglobulin during intercurrent pneumonia was described. A 64-year-old Japanese woman with a 12-year history of chronic ITP was refractory to steroids and azathioprine, and the platelet count was constantly less than 10 x 10(9)/l. During both acute upper respiratory infections and chronic cystitis due to E. coli, the platelet count transiently increased to more than 40 x 10(9)/l. High-dose intravenous gammaglobulin therapy successfully induced a remarkable increase in the platelet count, which persisted for 3 months, when gammaglobulin was administered during the intercurrent pneumonia. The bleeding tendency disappeared and transient remission of ITP was obtained. In contrast, the clinical efficacy of high-dose intravenous gammaglobulin proved to be only transient and slight, when administered before the onset of pneumonia or after recovery from pneumonia. These phenomena may suggest that high-dose gammaglobulin may enhance some positive mechanisms related to platelet increment in infectious diseases accompanied with chronic ITP.

Female↗
PubMed1994

Hepatocellular carcinoma with splenic metastasis developing after 16 years of chemotherapy for chronic myelogenous leukemia: a case report.

A case of hepatocellular carcinoma (HCC), which developed during chemotherapy for chronic myelogenous leukemia (CML), is presented. A 55-year-old Japanese man, who had received an alkylating agent for 16 years, was diagnosed as having HCC with clinically evident splenic metastases. The patient died of the HCC rupture three months after diagnosis. The autopsy revealed the HCC to have developed from the non-cirrhotic liver. In the present case, DNA damage due to the long-term chemotherapy with the alkylating agent for CML may have endowed the HCC induced by post-transfusion hepatitis and alcohol abuse with an aggressive proliferative potential. This is the first report on HCC in association with CML.

Busulfan↗
PubMed1993

The phosphatase inhibitor 2,3-diphosphoglycerate interferes with phospholipase D activation in rabbit peritoneal neutrophils.

In the present study, we examined the ability of the phosphatase inhibitors p-nitrophenyl phosphate and 2,3-diphosphoglycerate (DPG) to inhibit phospholipase D (PLD) activation in the rabbit peritoneal neutrophil. Also assessed were choline, a product of PLD-catalyzed hydrolysis of phosphatidylcholine, and its metabolite phosphocholine. PLD activity was determined by measuring the accumulation, in the presence of ethanol, of [3H]phosphatidylethanol ([3H]PEt) in neutrophils prelabeled with 1-O-[3H]octadecyl-2-lyso-snglycero-3-phosphocholine. Of the compounds tested, only DPG interfered with PLD activation by N-formyl-Met-Leu-Phe (fMLP) in a dose- and time-dependent manner. In contrast, it augmented fMLP-stimulated levels of [3H]inositol phosphates in myo-[3H]inositol-labeled neutrophils. DPG also prevented PLD activation by the calcium ionophore ionomycin and by phorbol 12-myristate 13-acetate. The suppression of PLD activation by DPG appeared to arise from direct interaction with the enzyme, as evidenced by a DPG competitive pattern of inhibition (Ki = 9.0 +/- 1.5 mM) for PLD from Streptomyces chromofuscus. These results suggest that DPG may be a useful tool for investigating the role of PLD in physiological function in a wide variety of cell types. Interestingly, DPG inhibited fMLP-induced N-acetyl-beta-glucosaminidase release and O2- generation by the cytochalasin B-primed neutrophils in a dose-dependent manner, whereas it had minimal effect (at concentrations up to 5 mM) on O2- generation induced by fMLP in nonprimed cells. These results suggest that PLD plays an important role in fMLP stimulation of both N-acetyl-beta-glucosaminidase release and O2- generation in the primed neutrophils, but that a PLD-independent pathway plays the primary role in O2- generation by the nonprimed neutrophils.

2,3-Diphosphoglycerate↗
PubMed1993

A micronucleus-specific sequence exists in the 5'-upstream region of calmodulin gene in Tetrahymena thermophila.

Tetrahymena thermophila possesses a transcriptionally inactive micronucleus and an active macronucleus. Both nuclei are developed from micronucleus-derived germ nuclei during conjugation. Extensive DNA rearrangement and transcriptional activation are known to be involved in macronuclear development, but little has been known about these processes in a particular functional gene. Therefore the micro- and macronuclear genomic DNAs for calmodulin gene were analyzed. A 1,384 bp micronucleus-specific sequence located about 3.5 kb upstream of calmodulin gene has been found, suggesting DNA rearrangement during macronuclear development. The micronucleus-specific sequence had 85% A + T, no extensive ORF, ATTAs at both ends, and two palindromic structures just outside of both ends. Interestingly, the micronucleus-specific sequence included a T-rich tract, T16CT5, in the middle, and a nearly complementary A-rich tract, A5TA10GA5, existed 7 bp upstream from the initiation codon. In addition, there was a 20 bp repetitive sequence TAAT(TAAC)4 about 100 bp upstream of the micronucleus-specific sequence and also in the promoter region of calmodulin gene. Although the functional significance of the micronucleus-specific sequence remains unclear, T16CT5 and TAAT(TAAC)4 elements might exert an influence on transcription of the calmodulin gene. Stringent Southern hybridization revealed that this micronucleus-specific sequence or very similar sequence(s) were abundant in the Tetrahymena micronuclear genome.

Animals↗
PubMed1993

c-erbB3 gene encodes secreted as well as transmembrane receptor tyrosine kinase.

c-erbB3 product is moderately expressed in gastric mucosa, especially in parietal cells. Northern blot analysis revealed that 6.2-kb c-erbB3 transcript was expressed in all gastric cancer cell lines examined, and that 1.4-kb c-erbB3 transcript was expressed as highly as 6.2-kb transcript in MKN45 cells. erbB3-S cDNA, corresponding to 1.4-kb c-erbB3 transcript, was cloned by rapid amplification of cDNA ends. Sequence analysis of erbB3-S cDNA showed that this 1.4-kb c-erbB3 mRNA encoded a secreted receptor. Analysis of partial genomic structure of c-erbB3 gene revealed that the exon specific to secreted receptor was identical with the 5' portion of the intron in c-erbB3 gene. c-erbB3 gene encodes secreted as well as transmembrane receptor tyrosine kinase due to alternative splicing.

Amino Acid Sequence↗