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Biomedical subjects

M Ida

Publications and source records attributed to M Ida.

At least 55 records · Page 3Linked to original sources
PubMed1998

Further examination of various administration protocols of pegylated recombinant human megakaryocyte growth and development factor on thrombocytopenia in myelosuppressed mice.

Thrombopoietin (TPO) is the recently isolated lineage-dominant hematopoietic factor that plays a pivotal role in the regulation of megakaryocytopoiesis and thrombopoiesis. In vivo studies have shown that daily multiple injections of pegylated human megakaryocyte growth and development factor (PEG-rHuMGDF), a truncated molecule related to human TPO, modified with polyethylene glycol, greatly improve thrombocytopenia and in most cases anemia and neutropenia in myelosuppressed animal models. In this study, we further examined various administration protocols of PEG-rHuMGDF on thrombocytopenia in mice treated with a combination of irradiation and carboplatin. After the myelosuppressive treatment on Day 0, mice received the same amount of PEG-rHuMGDF beginning on Day 1 by a single, 3 times (on alternate days), or 7 day daily administration. A single injection of PEG-rHuMGDF significantly reduced the severity and duration of thrombocytopenia and anemia with a concomitant accelerated recovery of megakaryocytic and erythroid progenitors in the bone marrow, similar to the 2 other administration protocols. As the start of a single injection of PEG-rHuMGDF was delayed, its therapeutic effects were attenuated. These results indicate that an administration of PEG-rHuMGDF at an earlier time after the myelosuppressive treatment is necessary to improve thrombocytopenia and anemia.

Animals↗
PubMed1997

Differential diagnosis of tumours of the minor salivary glands of the palate by computed tomography.

OBJECTIVE: To define the CT criteria for differentiating malignant from benign tumours of the minor salivary glands of the palate and to evaluate their accuracy. PATIENTS AND METHODS: CT findings of 63 patients with histopathologically proven minor salivary gland tumours of the palate (23 malignant, 40 benign) were retrospectively evaluated. RESULTS: Aggressive bone destruction was a specific finding of malignant tumours, but was seen in only 57% (13/23) of this series. Extension into the pterygopalatine fossa was observed in seven malignant and one benign tumour. Calcifications within a tumour were observed in four cases, all of which were malignant. These three CT findings were significantly more frequent in malignant tumours. Using any one of these as the criterion for the malignancy, the sensitivity was 78% (18/23), specificity 98% (39/40) and accuracy 90% (57/63). CONCLUSION: Malignant tumours of the minor salivary glands of the palate are very likely to show any or all of aggressive bone destruction, extension into the pterygopalatine fossa and calcification, whereas benign tumours can almost always be correctly diagnosed by their absence.

Calcinosis↗
PubMed1997

Periosteal new bone formation in the jaws. A computed tomographic study.

OBJECTIVES: To investigate the diagnostic significance of a periosteal reaction (PR) in diseases of the jaws. METHODS: The frequency of PR was investigated in 1142 patients who had undergone CT of the maxilla or mandible. The pattern of PR was categorized as either parallel, irregular, spicule or Codman's triangle. We examined the relationship of the pattern of PR to the specific disease categories of osteomyelitis, trauma, cysts, benign tumours and malignant tumors. RESULTS: Seventy patients were found to have PR. It was found in 40% of cases with osteomyelitis and 15% of malignant tumors. The only benign lesion was an eosinophilic granuloma. There were no cysts. The frequency of PR was higher in younger patient and in those with sarcomas or bone metastases compared with those with carcinomas. Ninety-one percent of the patients with osteomyelitis showed single or multi-layered PR parallel to the cortical bone, while 61% of those with malignant tumors had a spicule pattern. With the exception of Codman's triangle, none of the PR patterns were specifically associated with any one disease category. When the PR pattern was combined with the pattern of cortical bone destruction, 90% of the patients with PR could be correctly assigned to one or other of the four disease categories of osteomyelitis, trauma, benign lesion or malignant tumor. CONCLUSIONS: The pattern of PR on CT in combination with the pattern of the cortical destruction of the cortex is useful in differentiating osteomyelitis from malignant tumors.

Adult↗
PubMed1997

Computed tomography in the diagnosis of buccal space masses.

OBJECTIVE: To evaluate the CT features of buccal space masses. PATIENTS AND METHODS: Fifty-three cases of buccal space masses were reviewed retrospectively. The diagnosis was confirmed histopathologically in all except two. CT images were assessed for the number, location, internal architecture and margin of the lesions and their relation to the surrounding structures. RESULTS: The series comprised 44 tumors (33 benign and 11 malignant) and nine non-tumorous lesions. Buccal gland tumors were all found adjacent to the outer surface of the buccinator, in contrast to epidermoid cysts and accessory parotid tumors which were completely separate from it. Hemangiomas were characterized by multiple masses or the presence of phleboliths. When ill-defined margins, violation of fascial planes and aggressive bone destruction were used as the criteria for the malignancy, only seven out of 11 malignant tumors were correctly diagnosed (sensitivity 64%). CONCLUSION: CT was useful in demonstrating the presence and location of the masses in the buccal space and sometimes in the differential diagnosis. For a mass of uncertain cause in the buccal space, a buccal gland tumor is the most likely diagnosis. The value of CT in differentiating malignant from benign buccal space lesions is limited.

Adolescent↗
PubMed1997

Transformation of Arabidopsis thaliana with the codA gene for choline oxidase; accumulation of glycinebetaine and enhanced tolerance to salt and cold stress.

Glycinebetaine is one of the compatible solutes that accumulate in the chloroplasts of contain halotolerant plants when these plants are exposed to salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into glycinebetaine, has previously been cloned from a soil bacterium, Arthrobacter globiformis. Transformation of Arabidopsis thaliana with the cloned codA gene under the control of the 35S promoter of cauliflower mosaic virus enabled the plant to accumulate glycinebetaine and enhanced its tolerance to salt and cold stress. At 300 mM NaCl, considerable proportions of seeds of transformed plants germinated well, whereas seeds of wild-type plants failed to germinate. At 100 mM NaCl, transformed plants grew well whereas wild-type plants did not do so. The transformed plants tolerated 200 mM NaCl, which was lethal to wild-type plants. After plants had been incubated with 400 mM NaCl for two days, the photosystem II activity of wild-type plants had almost completely disappeared, whereas that of transformed plants remained at more than 50% of the original level. When exposed to a low temperature in the light, leaves of wild-type plants exhibited symptoms of chlorosis, whereas those of transformed plants did not. These observations demonstrate that the genetic modification of Arabidopsis thaliana that allowed it to accumulate glycinebetaine enhanced its ability to tolerate salt and cold stress.

Acclimatization↗
PubMed1997

[A case of hypertrophic spinal pachymeningitis].

A 79-year-old woman was admitted to our hospital complaining of gait disturbance. At the time of admission, she had incomplete monoparesis of the left lower extremity, with a sensory level of T6. MR images showed a thickened dura at the C6-T4 vertebral levels. The thickened dura showed low intensities on T1- and T2-weighted images, and was homogeneously enhanced by Gd-DTPA. Hypertrophic spinal pachymeningitis (HSP) was suspected, and laminectomy was performed from T2 to T3. The thickened dura was found and partially resected. Microscopically, the diagnosis was HSP. Steroid therapy was initiated after surgery. Postoperatively, the patient's physical status and radiographic images improved. The etiology of HSP is not clear in most cases. It is difficult to diagnose radiographically, although MR imaging can help differentiate it from other disorders. T1- and T2-weighted images of HSP show low intensities, and the T1-weighted image is homogeneously enhanced by Gd-DTPA. Treatment is early decompressive surgery with possible excision of the involved dura. Steroid therapy was effective in our case.

Aged↗
PubMed1997

[Autosomal dominant distal myopathy with rimmed vacuoles and cytoplasmic inclusions: report of a family].

We reported four patients with distal myopathy in the same family. Muscle weakness and atrophy started in the lower extremities, especially in the calf muscle, and it extended to the upper extremities and pelvic muscles to a variable extent. Facial and bulbar muscles were slightly involved in one case. The anterior tibial muscle tended to be better preserved than the calf muscle. Cardiac abnormalities were absent in any case. Serum creatine kinase activity was normal or mildly elevated. Skeletal muscle biopsies revealed myopathic process presenting rimmed vacuoles, eosinophilic cytoplasmic inclusions and/or subsarcolemmal mass. Ultrastructurally, cytoplasmic inclusions were composed of electron dense granular material and intermediate-sized filaments. There were membranous whorls and myelin-like figures which were the characteristic findings of rimmed vacuoles. Immunohistochemistry revealed accumulation of desmin, dystrophin and vimentin in the cytoplasm of degenerating muscle fibers and in the inclusion. In present patients, cardiac function was normal and the tibialis anterior muscle was relatively spared. These features were different from the autosomal dominant rimmed-vacuolar myopathy with desmin storage described in previous reports.

Adult↗
PubMed1997

[T2*-contrast perfusion study--principles, theory and clinical utility in evaluating cerebral hemodynamics].

Contrast-enhanced dynamic study is easily feasible with a clinical MR system, for evaluating cerebral perfusion. A bolus of the paramagnetic contrast agents such as Gd-DTPA produces inhomogenity of the regional magnetic field between the capillaries and extravascular proton, and causes a decrease of signal intensity in the perfused region with T2*-weighted sequences. Echo planar imaging (EPI) is suitable for contrast-enhanced dynamic study, because it is markedly susceptible and provides high temporal-resolution. Tracer kinetic approaches are used for analysis of the dynamic data to acquire various perfusion parameters such as time delta R2* curve, rCBF, rCBV and MTT. T2*-weighted contrast-enhanced perfusion imaging is useful, especially, for detecting hyperacute ischemia and its therapeutic window, and depicting vasculature and ability of the brain tumors.

Blood Flow Velocity↗
PubMed1997

[A case of dyskeratosis congenita with acute interstitial pneumonia].

This is a rare case of Dyskeratosis Congenita (DC) with acute interstitial pneumonia. A 51-year-old man with DC was admitted to our hospital because of cough, sputum and fever. Chest X-ray film showed ground glass opacities in all lung fields for a while steroid's therapy proved effective, but about seven months later the patient's condition became serious. Methylprednisolone, cyclophosphamide and mechanical ventilation therapy were not effective. He died and an autopsy was performed. The lung specimen showed Organizing Diffuse Alveolar Damage, and some parts pointed to bacterial infection. But Pneumocystic carinii pneumonia and Fungal infections were not found. It is therefore necessary to conduct intensive examinations of lung involvement of patients with Dyskeratosis Congenita.

Acute Disease↗
PubMed1996

Pervanadate stimulation of wortmannin-sensitive and -resistant 2-deoxyglucose transport in adipocytes.

Pervanadate mimics several distinct insulin effects, including stimulation of hexose uptake in the in vitro system, and reduces the blood glucose level in streptozotocin-treated diabetic rats. It has been proposed that pervanadate induces insulin-like effects mediated through autophosphorylation and activation of insulin receptor (IR) even in the absence of insulin by inhibiting protein tyrosine phosphatases. This study focused on the mechanism of pervanadate action on hexose uptake. Both insulin (100 nM) and pervanadate (100 microM), a protein tyrosine phosphatase inhibitor, induced a marked increase in the phosphorylation at tyrosine residues of IR and insulin receptor substrate 1 (IRS-1) and in 2-deoxyglucose uptake in 3T3-L1 adipocytes. Wortmannin (1 microM), a specific phosphatidylinositol 3-kinase (PI 3-kinase) inhibitor, inhibited the increased 2-deoxyglucose uptake by insulin completely but that by pervanadate only partially. On the other hand, both insulin- and pervanadate-stimulated PI 3-kinase activities were inhibited completely by wortmannin (100 nM), suggesting that the pervanadate-induced wortmannin-resistant effect on hexose uptake may be mediated through a PI 3-kinase-independent pathway. This pervanadate-induced wortmannin-resistant effect was abolished by ST-638, a specific tyrosine kinase inhibitor. These data suggest that at least two distinct tyrosine phosphorylation pathways may be involved in the insulin-like effect of pervanadate.

3T3 Cells↗
PubMed1996

In vivo effects of pegylated recombinant human megakaryocyte growth and development factor on hematopoiesis in normal mice.

The in vivo effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a truncated molecule of recombinant human thrombopoietin modified with polyethylene glycol, were investigated in normal Balb/c mice. PEG-rHuMGDF was more potent in producing platelets and the dose-response curve was steeper compared with the case of the nonpegylated form of this molecule. Five consecutive injections with PEG-rHuMGDF caused a dose-dependent increase in peripheral platelet counts with a peak on day 8. There was a dose-dependent rise in platelet counts on day 8 at daily doses from 0.333 to 30 micrograms/kg. Intermediate doses of PEG-rHuMGDF (1.111 to 10 micrograms/kg/day) caused a significant decrease in mean platelet volume, and conversely, higher doses of PEG-rHuMGDF (30 to 270 micrograms/kg/day) induced a dose-dependent increase in mean platelet volume. There was a dose-dependent decrease in hemoglobin concentration with a minimum on day 8 but no significant reduction in reticulocyte counts following PEG-rHuMGDF administration. White blood cell counts were unchanged by PEG-rHuMGDF treatment. Marrow megakaryocyte size enlarged to 1.5-fold and the number of marrow megakaryocytes increased to sixfold by consecutive administration of PEG-rHuMGDF at 30 micrograms/kg/day. A twofold increase in the number of marrow megakaryocytic progenitor cells (colony-forming units-megakaryocyte) was also observed. Marrow erythroid progenitor (colony-forming units-erythroid) counts decreased but splenic colony-forming units-erythroid, marrow and splenic erythro/myeloid progenitor cell counts, and splenic granulocyte/macrophage progenitor cell counts increased with PEG-rHuMGDF treatment. Marrow and splenic erythroid burst-forming cells were unchanged. These results indicate that PEG-rHuMGDF, a truncated molecule of thrombopoietin, is a potent stimulator for megakaryopoiesis and thrombopoiesis, and also affects the development of other hematopoietic cells in normal mice.

Animals↗
PubMed1996

Effects of pegylated recombinant human megakaryocyte growth and development factor on thrombocytopenia induced by a new myelosuppressive chemotherapy regimen in mice.

Thrombopoietin, the endogenous c-Mpl ligand, is a novel lineage-specific hematopoietic factor that plays a pivotal role in the regulation of megakaryocytopoiesis and thrombopoiesis. In this study, we examined the effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a truncated molecule of recombinant human c-Mpl ligand derivatized with polyethylene glycol, on myelosuppressive chemotherapy-induced thrombocytopenia in mice. We developed a new murine model of thrombocytopenia induced by i.v. injections of mitomycin C (MMC) for two consecutive days. In control mice, platelet counts began to decrease on day 6, reached a nadir of less than 5% of basal level on day 14, and could not recover to basal level by day 26. Administration of PEG-rHuMGDF greatly enhanced recovery of the number of megakaryocyte progenitor cells and the megakaryocytes in bone marrow, and markedly reduced the severity of thrombocytopenia; it also accelerated platelet recovery in a dose-dependent manner in myelosuppressed mice. Mice receiving consecutive administration of higher doses of PEG-rHuMGDF showed no thrombocytopenia but rather had platelet counts being increased over basal level. Although absolute neutrophil counts and red cell counts also were decreased following MMC treatment, administration of PEG-rHuMGDF also improved neutropenia and anemia. Administration of PEG-rHuMGDF on alternate days or once a week after chemotherapy was almost as effective as consecutive administration in improving thrombocytopenia. Combined administration of PEG-rHuMGDF and rHuG-CSF had an additive effect on improvement of thrombocytopenia and neutropenia. These results suggest that PEG-rHuMGDF is a therapeutically effective agent in the treatment of thrombocytopenia associated with chemotherapy.

Animals↗
PubMed1996

Arthrotomographic sign of a 'double line' as an indicator of disc folding and sideways disc displacement in the temporomandibular joint.

Dual-space, single-contrast arthrotomolgraphy of the TMJ was performed on a 19-year-old woman with a history of pain and clicking. Simultaneous multi-layer arthrotomography with computed radiography was used for the present examination. Anterior disc displacement with reduction was observed in the sagittal plane, together with a double line in the lower joint space. The double line was interpreted as disc folding and sideways disc displacement and was confirmed in the coronal plane.

Adult↗
PubMed1996

[Middle lobe syndrome--incidence and relationship to atypical mycobacterial pulmonary disease].

We evaluated the incidence of middle lobe syndrome in the Haibara area, and its relationship to atypical mycobacterial infection. Of the 30,588 persons who underwent annual mini-chest roentgenography in 1992 or 1993 or both, 51 (0.17%) had middle lobe syndrome, diagnosed from posteroanterior and lateral chest X-ray films. The incidence was significantly higher in persons over 50 years old than in persons under 50 years old (0.26% vs 0.02%: p < 0.001), and was higher in femals than in males (0.20% vs 0.11%: p = 0.527). Of 16 patients examined by bronchoscopy and computed tomography, 7 showed evidence of cylindrical bronchiectasis, and four had mycobacterium avium complex pulmonary disease presenting as middle lobe syndrome. All four were women who were 51 years of age or older and none had predisposing pulmonary disorders. Computed tomography showed multiple nodular shadows with or without bronchiectasis located in the middle lobe or the lingula. Cavitary lesions were not seen. These results indicate that middle lobe syndrome is not rare, and that infection with mycobacterium avium complex should be considered when multiple nodular shadows are seen in the middle lobe or the lingula.

Adult↗
PubMed1996

[Swyer-James syndrome with unilateral pulmonary edema].

A 64-year-old man with ischemic heart disease was admitted to our hospital because of dyspnea. A chest X-ray film showed a butterfly shadow in the right lung. A chest X-ray film obtained before the patient had respiratory symptoms showed hyperlucency of the left lung. CT scans obtained at maximal inspiration and expiration revealed air trapping. Pulmonary arteriography showed that the left pulmonary artery and its branches were very small. Cardiac catheterization showed poor cardiac function. Swyer-James syndrome should be included in the differential diagnosis of patients with unilateral pulmonary edema.

Bronchial Diseases↗
PubMed1996

Improvement of thrombocytopenia following bone marrow transplantation by pegylated recombinant human megakaryocyte growth and development factor in mice.

We examined whether pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) is capable of improving thrombocytopenia and promoting thrombopoietic reconstitution following lethal irradiation and bone marrow transplantation (BMT) in mice. Immediately after receiving 10 Gy whole body irradiation (day 0), male C3H/HeN mice were inoculated with 10(6) bone marrow cells obtained from syngeneic mice. Circulating platelet counts decreased to below 4% of the normal counts with a nadir on day 10, and then returned to the normal level on day 28 in the control mice undergoing BMT. Subcutaneous consecutive treatment with PEG-rHuMGDF at doses from 10 to 300 micrograms/kg/day from day 1 for 13 days significantly improved the platelet nadir and promoted platelet recovery. The white blood cell counts and hemoglobin concentration following BMT were not influenced by the PEG-rHuMGDF. PEG-rHuMGDF-injection starting from day 5 did not improve the platelet nadir following BMT. Furthermore, administration with PEG-rHuMGDF on alternate days at 55.7 micrograms/kg/day for 7 days or at an interval of 3 days at 78 micrograms/kg/day for 4 days (twice a week for 2 weeks) had a significant efficacy, but these administration regimens had less efficacy than consecutive administration at 30 micrograms/kg/day for 13 days. The numbers of megakaryocytes and megakaryocyte progenitor cells decreased to 5 and 0.2% of normal level, respectively, in the control mice. Consecutive administration of PEG-rHuMGDF enhanced the recovery of the mean number of these cells compared to those in vehicle-treated mice, although such effects were not statistically significant except for the number of megakaryocyte progenitors on day 12. These results suggest that consecutive treatment with PEG-rHuMGDF beginning from the day after BMT may be effective in improving thrombocytopenia following BMT.

Animals↗