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Biomedical subjects

K Ogata

Publications and source records attributed to K Ogata.

At least 127 records · Page 7Linked to original sources
PubMed1998

Effect of EPC-K1 on myocardial infarct size in a rat model with coronary artery occlusion and reperfusion.

1. The ability of EPC-K1 to improve myocardial infarction was evaluated in a rat model with coronary artery occlusion and reperfusion. 2. The myocardial infarct size was 30.5 +/- 1.7% by intravenous (i.v.) administration and 28.8 +/- 2.7% by intraduodenal (i.d.) administration of the saline EPC-K1 at doses between 1 and 10 mg/kg, i.v. and at doses between 50 and 200 mg/kg, i.d., reduced myocardial infarct size dose dependently. Significant reduction in myocardial infarct size was found at a dose of 10 mg/kg, i.v., and 200 mg/kg, i.d.

Animals↗
PubMed1998

Pulmonary toxicity after granulocyte colony-stimulating factor-combined chemotherapy for non-Hodgkin's lymphoma.

Sporadic cases have developed pulmonary toxicity after receiving chemotherapy and granulocyte colony-stimulating factor (G-CSF). However, because such cases received chemotherapy that alone frequently causes pulmonary toxicity, the role of G-CSF in this toxicity has been unclear. CHOP therapy (cyclophosphamide, doxorubicin, vincristine and prednisolone) only slightly induces pulmonary toxicity. However, we observed a considerable incidence of this toxicity in non-Hodgkin's lymphoma subjects receiving CHOP therapy and G-CSF (6 out of 52 subjects, 11.5%). In this cohort, among various characteristics, including the dose and interval of CHOP therapy, only the mean peak leucocyte count (MPLC) with each therapy cycle was associated with development of this toxicity (MPLC > or = 23.0 x 10(9) l(-1), 6 out of 29 cases; MPLC < 23.0 x 10(9) l(-1), 0 out of 23 cases; P = 0.020). These findings suggest that the effect of G-CSF is the main determinant of the pulmonary toxicity in these cases. Because the toxicity was associated with a large MPLC and did not recur in cases readministered G-CSF, an idiosyncratic reaction to G-CSF is unlikely to be the pathogenesis of this toxicity. Thus, lowering the G-CSF dose seems to be useful in the prevention of this toxicity. In all six cases, the time course of manifestation of the toxicity was the same, and early application of high-dose corticosteroid led to cure. This knowledge will be helpful in the care of similar cases.

Adult↗
PubMed1998

Plasma thrombopoietin (TPO) levels and expression of TPO receptor on platelets in patients with myelodysplastic syndromes.

Data on endogenous thrombopoietin (TPO) levels and their regulation in myelodysplastic syndromes (MDS) are sparse. We examined the plasma TPO level of 85 MDS patients by a sensitive enzyme immunoassay and the platelet expression of TPO receptor (TPO-R) protein, which metabolizes endogenous TPO, in 19 MDS patients with an equilibrium binding assay using 125I-TPO. The MDS patients had higher plasma TPO levels (7.0 +/- 9.3 fmol/ml) than 52 normal subjects (P < 0.0001). Refractory anaemia (RA) patients (n = 39) had higher plasma TPO levels than patients (n = 28) with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-t) (P = 0.0002), irrespective of similar platelet counts in these groups. The plasma TPO level correlated inversely with the platelet count in RA patients (P = 0.0027) but not in RAEB and RAEB-t patients (P = 0.7865). These data suggest that the physiological pathway for TPO production and metabolism is conserved, at least partially, in RA, but deranged in RAEB/RAEB-t. The number of TPO-R per platelet was significantly smaller in 19 MDS patients (17.5 +/- 13.3) than in normals (P = 0.0014), but similar between RA patients and patients with RAEB and RAEB-t. Further, the bone marrow megakaryocyte count, determined in 31 MDS patients, was quite similar between RA patients and patients with RAEB or RAEB-t. Thus, in addition to thrombocytopenia, a reduced platelet TPO-R number may contribute to elevated plasma TPO levels in MDS, and a regulatory pathway for circulating TPO other than platelet TPO-R and marrow megakaryocytes, such as blasts expressing TPO-R, may operate in RAEB/RAEB-t.

Blood Platelets↗
PubMed1998

ATPase associated with ribosomal 30S-5SRNP particles and 40S subunits of rat liver.

The ATPase activity of rat liver 30S-5SRNP particles prepared by EDTA treatment of 80S ribosomes, and that of 40S subunits were investigated in correlation with polypeptide elongation. The ATPase activity of 30S-5SRNP particles was higher than that of 40S subunits. Poly(U) and TMV RNA stimulated the ATPase activity of 30S-5SRNP particles more markedly than that of 40S subunits. These two kinds of particles also showed intrinsic GTPase. Poly(U) enhanced the GTPase activity of 30S-5SRNP particles but not that of 40S subunits. An elongation factor (EF-1alpha, EF-2, or EF-1alphabetagamma) alone or in combination with poly(U) and/or other elongation factors stimulated the ATPase activities of both particles. The extent of stimulation of the ATPase activity by a combination of these components was usually somewhat higher than or similar to the sum of those with the individual components. The extents of stimulation by these components were higher in the case of 30S-5SRNP particles than that of 40S subunits, indicating the importance of the 5SRNP moiety in the former particles. The intactness of 18SrRNA was required for promotion of the ATPase activity of 30S-5SRNP particles by Phe(+), (-)tRNA(Phe). The ATPase activities of the two kinds of particles by themselves or those observed with the combinations of the components mentioned above were inhibited by several kinds of translation inhibitors. The degrees of inhibition were generally higher for 30S-5SRNP particles. The ATPase activity of 40S subunits was enhanced by spermidine, suggesting the importance of the conformational change induced by it. These results imply the participation of the intrinsic ATPase of 30S-5SRNP particles and 40S subunits in polypeptide elongation, and the important role of the 5SRNP moiety of 30S-5SRNP particles in the ATPase activity.

Adenosine Triphosphatases↗
PubMed1998

Drill-hole guide for internal fixation of fractures of the mandibular condyle.

We have developed a drill-hole guide valuable in accurately positioning the fracture of the mandibular ramus. It operates by introducing a Kirschner wire through the fracture stump from the mandibular angle to the condyle. A 2.0- to 2.4-mm-diameter Kirschner wire is drilled into the ramus from below and proceeds up to the condylar fragment through the stump of the fracture. With this guide, 15 patients with 23 subcondylar fractures underwent open reduction with Kirschner wire fixation. In each case, wire, by means of a pinning technique, was inserted accurately from the mandibular angle to the repositioned condyle.

Adult↗
PubMed1998

Reappraisal of the expression of mast cell proteases of Mongolian gerbils (Meriones unguiculatus).

Mast cell proteases in the tongue and jejunum of Mongolian gerbils (Meriones unguiculatus) were examined by enzyme-histochemical methods. Both trypsin-like (tryptase) and chymotrypsin-like (chymase) protease activities were demonstrated in mast cells in the tongue of fresh cryosections. When frozen sections of the tongue were post-fixed in various fixatives, those fixed in Carnoy's fluid showed strongest enzyme activities. Tryptase and chymase activities in paraffin sections of both tissues were well preserved when tissues were fixed in Carnoy's fluid at 4 degrees C for 15 min. However, enzyme activities in both tissues, especially in the tongue, were drastically reduced by longer fixation time and higher temperature. When Carnoy-fixed (4 degrees C for 15 min) paraffin sections were treated with heparinase I or chondroitinase ABC before enzyme-histochemical stainings for proteases, tryptase activities were lost entirely in the tongue and mostly in the jejunum by heparinase I digestion, and slightly in both organs by chondroitinase ABC digestion. In contrast, chymase activities at both sites were not influenced by these pretreatments. These results show that although mast cells in the tongue as well as in the jejunum of Mongolian gerbils contain both tryptase and chymase activities, their stability to fixations is variable among organs so that tissue fixation conditions are crucial for the preservation. At least some part of the stability of mast cell proteases is dependent on the proteoglycans present in mast cell granules.

Animals↗
PubMed1998

Cloning, sequencing, and expression of an endoglucanase gene from the rumen anaerobic fungus Neocallimastix frontalis MCH3.

A cDNA clone encoding an endo-1,4-beta-glucanase from a rumen fungus, Neocallimastix frontalis MCH3, was isolated. The nucleotide sequence showed that the gene, celA, encoded a multidomain enzyme containing a family 5 catalytic domain and a reiterated sequence that is involved in the association of a multienzyme complex, the cellulosome. The enzyme expressed in Escherichia coli showed the highest activity against carboxymethylcellulose at 40 degrees C and pH 8.5.

Amino Acid Sequence↗
PubMed1998

Short report: gnathostomiasis in Mexico.

Gnathostomiasis is an important food-borne parasitic zoonosis that is endemic mainly in Asian countries where some people prefer to eat raw freshwater fish. In North America, the first recorded case of gnathostomiasis was in Mexico in 1970, and the numbers of gnathostomiasis patients in Mexico seems to be increasing dramatically with time. However, the epidemiology of this disease in Mexico has never been described in detail. Here we review the current status of gnathostomiasis in Mexico.

Adult↗
PubMed1998

Clinical manifestations and immunodiagnosis of gnathostomiasis in Culiacan, Mexico.

Gnathostomiasis was first described in Mexico in 1970, and endemic areas have been spreading in six states of this country. In Culiacan, Sinaloa, 300 cases of cutaneous larva migrans were recorded between January 1992 and December 1995. In addition, a Gnathostoma larva was surgically removed from the eye of one patient. Cutaneous lesions were observed mainly on the face, neck, arms, and legs. About 70% of the patients showed eosinophilia. A skin biopsy was carried out on 35 patients and the parasite was identified in histopathologic sections of 12 of these patients. In four patients, the larva migrated out spontaneously from the skin. An enzyme-linked immunosorbent assay using a crude somatic extract of adult Gnathostoma doloresi worms showed that 93% of the patients were seropositive, confirming the reliability of clinical diagnosis. A total of 14 advanced third-stage Gnathostoma larvae were found in four species of ichthyophagous birds captured on dams and dikes near the city of Culiacan. Scanning electron micrographs of human and bird larvae showed that they were morphologically indistinguishable from G. spinigerm. We conclude that the life cycle of Gnathostoma has been established in Sinaloa, and has become a serious public health issue for residents.

Adolescent↗
PubMed1998

[An adult case of peripheral facial nerve palsy following acute cerebellitis associated with high antibody titers against varicella-zoster virus].

Here we report a case of acute cerebellitis, in which the patient developed right peripheral facial palsy during the recovery phase of cerebellar ataxia. A 67-year-old man developed truncal and limb ataxia following a fever, general fatigue and anorexia. He was diagnosed to have acute cerebellitis. While the ataxia symptoms were improving without any treatment, right peripheral facial nerve palsy developed and an MRI revealed an enhancement of the right facial nerve proximal to the geniculate ganglion. After treatment with acyclovir and corticosteroids, his facial nerve palsy and ataxia both gradually improved. There has been no previous report of an adult case who developed peripheral facial nerve palsy during the recovery phase of acute cerebellitis. This case indicates that a wide spectrum of neurological complications may develop in association with a varicella-zoster virus infection.

Acute Disease↗
PubMed1998

[Hyponatremia in Duchenne muscular dystrophy on mechanical ventilation].

To evaluate the pathomechanism of hyponatremia occasionally seen in Duchenne muscular dystrophy (DMD) on intermittent positive pressure ventilation (IPPV), we performed a comparative study on 26 DMD patients, 7 IPPV in trachetomized intermittent positive pressure ventilation (TIPPV), 6 nasal intermittent positive pressure ventilation (NIPPV), 6 cuirass respirator (CR), and 7 spontaneous breathings (SB). We followed fluctuation of serum sodium levels for several years. Since the serum sodium level was gradually reduced with years on mechanical ventilation, we speculated positive relationship between hyponatremia and antidiuretic hormone (ADH) secretion. Serum sodium levels of 135.6 +/- 2.8 mEq/L in average on IPPV (TIPPV + NIPPV) patients was significantly lower than the levels of 137.8 mEq/L +/- 0.98 on CR patients and 138.8 +/- 0.69 mEq/L on SB patients. Plasma ADH levels in IPPV patients were not reduced when plasma osmolarity was less than 280 mOSm/L. Previous reports showed that ADH was inappropriately secreted only during IPPV with positive end expiratory pressure (PEEP). Ours is the first report of inappropriate secretion of ADH during IPPV without PEEP. It becomes clear that inappropriate ADH secretion is one of the causes of hyponatremia in DMD, though the exact mechanism is not clear. We should bear in mind the change of serum electrolyte level in ventilated DMD patients, especially patients on antidepressant known to release of ADH.

Adult↗
PubMed1998

Lymphoblastic lymphoma of natural killer cell origin, presenting as pancreatic tumour.

AIMS: We describe the first case of lymphoblastic lymphoma (LBL) of natural killer (NK) cell origin initially presenting as a pancreatic tumour, and review this type of lymphoma. METHODS AND RESULTS: A 38-year-old woman with abdominal pain was found to have a pancreatic mass. Twenty days later, she developed diffuse lung infiltrates and leucoerythroblastosis of the peripheral blood, and her bone marrow was diffusely infiltrated with blasts. The blasts were positive for CD56, CD16 and P-glycoprotein, but lacked cytoplasmic azurophilic granules, T. B and myeloid cell markers on the cell surface, rearrangement of the genes for T-cell receptor and immunoglobulin, and the Epstein-Barr virus (EBV) genome. The diagnosis was LBL of NK cell origin. She received aggressive therapy, but died of the lymphoma. In contrast to ordinary NK-cell lymphoma, this case and reported cases of LBL of NK-cell origin showed the following common characteristics. The tumour cells often lack cell surface CD2, cytoplasmic CD3, cytoplasmic azurophilic granules, and EBV genome. The prognosis was extremely poor. CONCLUSIONS: LBL of NK-cell origin should be included in the differential diagnosis of pancreatic tumours. To fully characterize this type of lymphoma, further cases must be evaluated.

Adult↗
PubMed1998

[T 0 N 2 M 0 small cell lung cancer in a patient with Lambert-Eaton myasthenic syndrome].

We report an unusual case of T 0 N 2 M 0 small cell lung cancer in a patient with Lambert-Eaton myasthenic syndrome (LEMS). A 52-year-old man began to notice muscle weakness in a left limb in January 1996, which was followed by muscle weakness in his left arm and fingers, appetite loss, and general fatigue. An electromyogram (EMG) showed the waxing phenomenon in response to high-frequency repetitive stimulation. Lambest-Eaton myasthenic syndrome was diagnosed, based on his symptoms and EMG findings. Chest computed tomography (CT) was done, and left paratracheal, tracheobronchial, subaortic, and hilar lymphadenopathy were found. No mass was seen in either lung field. Cytologic examination of the sputum and bronchial lavage fluid were done, but no malignant cells were found Small cell lung cancer was diagnosed after thoracoscopic resection of the subaortic lymph nodes. No metastases were detected by bone scintigraphy, abdominal CT, or magnetic resonance imaging of the brain. Complete response and resolution of symptoms were obtained by chemotherapy and irradiation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

[Somatic mosaicism of p(CTG)n expansion in a case of myotonic dystrophy with parotid tumor].

Myotonic dystrophy (MD) is an autosomal dominant systemic disorder with an unstable expansion of the CTG triplet repeat in the 3'-untranslated region of the gene encoding myotonine protein kinase (DMPK) which maps to chromosome 19q13.3. Somatic mosaicism of CTG repeats in MD has been reported; and it has been observed that CTG repeats in tumor tissues associated with MD are more expanded than the other tissues. It is not rare that parotid tumors are found in patients with MD. We performed Southern blot analysis for tissues from the parotid tumor, the normal parotid gland, the skeletal muscles, and the leukocyte from a 60-year-old patient with MD. CTG repeat was most expanded in the parotid tumor, and the normal parotid gland had longer expansion of CTG repeat than the skeletal muscles. The leukocyte had the shortest expansion of CTG repeat. The expansion of CTG repeat in the parotid tumor may be related to active cell division and may underlie the occurrence of tumors in MD.

Adenoma, Pleomorphic↗
PubMed1998

[Treatment of nocturnal periodic hypoxemia with safrazine hydrochloride in a patient with Duchenne muscular dystrophy under nasal intermittent positive pressure ventilation].

Nocturnal periodic hypoxemia occurring in a 25-year-old Duchenne muscular dystrophy patient under NIPPV control was successfully treated with monoamine oxydase inhibitor (MAOI), safrazine hydrochloride. Five mg of safrazine hydrochloride was administered before sleep, and the periodic hypoxemia disappeared within 14 days. The effect lasted almost seven months without notable side effect. MAOI may be effective for nocturnal hypoventilation through suppression of REM sleep as in the case of tricyclic antidepressants. The effect of tricyclic antidepressants appears immediately. However, it usually fades away within forty days. Safrazine hydrochloride was effective obviously longer than tricyclic antidepressants. Consequently MAOI may be a hopeful candidate of medication for a treatment of nocturnal periodic hypoxemia in Duchenne muscular dystrophy.

Adult↗