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Biomedical subjects

H Fujimori

Publications and source records attributed to H Fujimori.

At least 55 records · Page 3Linked to original sources
PubMed1995

Organomercurial resistance determinants in Pseudomonas K-62 are present on two plasmids.

Pseudomonas strain K-62 was found to contain six plasmids. A mutant derivative cured of the 26-kb plasmid showed a higher sensitivity to mercurials; however, the strain was still able to volatilize them. Loss of the 68-kb plasmid in addition to the 26-kb plasmid abolished the ability of mercury volatilization in this strain and led to a further decrease in the level of mercurial resistance. These results are the first to demonstrate that the organomercurial resistance of Pseudomonas strain K-62 is plasmid-based, and that both the 26- and 68-kb plasmids are required for full expression of the mercurial resistance. Probes specific for the mer genes merA, merB, and merR strongly hybridized with the 26-kb plasmid, but not with the 68-kb plasmid. Two fragments of the 26-kb plasmid that hybridized with the mer genes were cloned and expressed in Escherichia coli. One recombinant plasmid (pMRA17) inducibly encoded a typical broad-spectrum mercurial resistance, whereas the other recombinant plasmid (pMRB01) constitutively conferred hypersensitivity to phenylmercury in the absence of mercuric reductase activity. The results suggest that the two organomercurial lyases in the cells are transcribed from different operator-promoters.

Chromosome Mapping↗
PubMed1995

Effect of iron as a new type of phosphate binder in hemodialysis patients.

Hyperphosphatemia is one of the major problems requiring management in the majority of hemodialysis patients and they require phosphate-binding agents to control the hyperphosphatemia. Aluminum hydroxide and calcium compounds are used currently as phosphate-binding agents to treat hyperphosphatemia, but these compounds can cause undesirable side effects. Therefore, the development of new phosphate-binding agents is imperative. It is well known that oral and intravenous administration of iron causes hypophosphatemia. We hypothesized that this side effect of iron may be beneficial for the treatment of hyperphosphatemia in hemodialysis patients. Consequently, we conducted a fundamental and clinical investigation of the effects of iron administration. Membrane permeability of phosphorus in a mixture of sodium ferrous citrate and dessicated aluminium hydroxide in the presence of hydrogenated lecithin as a phosporic compound was examined. Fifteen patients undergoing hemodialysis were treated with 150 mg of sodium ferrous citrate given orally for eight weeks. The permeability of the filtering membrane to phosphorus decreased in accordance with the dosage of sodium ferrous citrate and dessicated aluminum hydroxide. The degree of phosphate-binding effect of sodium ferrous citrate was larger than that of dessicated aluminum hydroxide. Serum phosphorus decreased significantly during the experiment. These results suggest that the oral administration of sodium ferrous citrate as a new phosphate binder is a useful therapeutic method for hemodialysis in patients with hyperphosphatemia.

Administration, Oral↗
PubMed1995

[Pulmonary alveolar proteinosis associated with myelodysplastic syndrome].

A 57-year-old man with myelodysplastic syndrome developed dyspnea on exertion in September 1993. Chest X-ray film showed diffuse infiltrative shadows in the middle and lower lung fields on both sides. The infiltrates were prominent in the perihilar regions but less so in the periphery, consistent with a "bat wing pattern." Milky fluid was obtained by bronchoalveolar lavage. The specimens obtained from transbronchial lung biopsy were compatible with the pathological findings of pulmonary alveolar proteinosis with amorphous periodic acid-Sciff-positive materials in the alveolar spaces. Impaired function of alveolar macrophages was demonstrated from their abnormally low phagocytosis of FITC-labeled latex beads. Whole lung lavage under general anesthesia was done twice, but the patient died because of progression of respiratory failure.

Fatal Outcome↗
PubMed1994

Popliteal venous aneurysm with pulmonary embolism.

A 29-year-old female was admitted to the hospital because of increasing exertional dyspnea, chest oppressive feeling and palpitation. Lung perfusion scan, pulmonary angiography, and venography of the lower extremities revealed multiple pulmonary embolism and a right popliteal venous aneurysm as the probable source of emboli. B-mode/Doppler echography and magnetic resonance imaging were useful for the preoperative evaluation. Following anticoagulant therapy and thrombolytic therapy using intravenous heparin and urokinase, respectively, the popliteal venous aneurysm was surgically excised; the walls contained organized thrombus. She delivered a baby without any complication 2 years after the surgery.

Adult↗
PubMed1994

Absorbed doses modified by exposure settings with rotational panoramic radiography.

Absorbed doses to parotid gland, cervical vertebrae and thyroid gland were measured with various exposure settings of the tube voltage and tube current during use of rotational panoramic radiographs , Veraview (J. Morita Corp., Kyoto, Japan) and PM 2002 CC (Planmeca Oy, Helsinki, Finland) using Rando phantom and thermoluminescence dosimeters. The magnitude of each absorbed dose was greatest in the parotid gland, followed in order by the cervical vertebrae and thyroid gland and was proportional to tube current. The increase of the thyroid gland absorbed dose with increasing tube voltage was steeper than were the increases in the absorbed doses in either the parotid gland or the cervical vertebrae.

Absorption↗
PubMed1994

Absorbed dose reduced by sliced exposure using sector selector system with rotational panoramic radiography.

Sliced exposures which restrict the exposed area and adjust the region of diagnosis are possible using a sector selector system which is installed in the rotational panoramic radiograph, PM 2002 CC (Planmeca Oy, Helsinki, Finland). The effects of altering the horizontal and vertical sector selector system on thyroid gland dose were measured using Rando Phantom and thermoluminescence dosimeters. The horizontal sector selector system clarified that the most of the thyroid gland dose was delivered from exposure of the mandibular region. The vertical sector selector system clarified that scattered x-rays which originated from primary x-rays curved at the incisor and canine, premolar and molar, and ramus regions contributed equally to the thyroid gland dose.

Humans↗
PubMed1993

Absorbed doses with intraoral radiography. Function of various technical parameters.

Both the maxillary incisor and mandibular molar regions of a Rando phantom were radiographed using specific technical parameters. The parotid gland and thyroid gland doses were measured using thermoluminescence dosimetry. Tube voltage, total filtration, mAs, collimation, and cone length were varied while keeping the other factors constant. Increased tube voltage or total filtration generally resulted in a slightly increased absorbed dose. Absorbed dose was decreased as the beam was more tightly collimated or the cone length was increased.

Absorption↗
PubMed1993

Dose reduction to the thyroid gland in intraoral source radiography.

Organs near the oral cavity may be exposed to unacceptably high levels of radiation in intraoral source radiography. Three methods for reducing the dose to the thyroid gland have been investigated. A restriction of the exposure geometry by use of the B and C types of applicator was an efficient means of dose reduction. Absorbed doses to the thyroid gland were 30-50% less than those obtained when using the A-type applicator. A 10 degree upward inclination of the occlusal plane reduced the dose by 20%. In contrast, three thyroid protectors had no effect on dose reduction.

Absorption↗
PubMed1993

Morphometric analysis of image distortion with rotational panoramic radiography.

We studied the image distortion of spherical objects that occurred during rotational panoramic radiography. We measured the magnification of height, width, perimeter and area, and calculated the circularity index to quantify the distortion. Spherical objects of different diameters were projected on the film. A complex relationship was found between the position and the horizontal magnification for each anatomical region. The object's size influenced the horizontal magnification to a considerable extent. The greatest changes in circularity occurred at the midline. This morphological distortion was caused by non-symmetrical projection during the scanning of these spherical objects, which resulted from the continuous changes in the scanning velocity and the position of the x-ray beam. This result suggests a complex distortion of the inner structures of macroscopic objects.

Humans↗
PubMed1992

Cavernous hemangioma over the anterior fontanelle.

This is a report of an extremely rare case of cavernous hemangioma over the anterior fontanelle in a 5-year-old boy. Cavernous hemangioma is most common in or beneath the skin of the face, neck, and extremities and sometimes occurs in the scalp. Although cavernous hemangioma is often quoted in the literature as a differential diagnosis of a mass located at the anterior fontanelle, we could not find an illustrative case in published articles. We discuss the characteristics and differential diagnosis of cavernous hemangioma over the anterior fontanelle.

Carotid Arteries↗
PubMed1992

Foramen magnum meningioma and arachnoid cyst coinciding in the lateral cerebellomedullary cistern--case report.

An extremely rare foramen magnum meningioma associated with an arachnoid cyst in the lateral cerebellomedullary cistern occurred in a 65-year-old female presenting with dizziness. Neuroimaging revealed a meningioma at the left lateral edge of the foramen magnum and an arachnoid cyst mainly located in the right lateral cerebellomedullary cistern, compressing the medulla oblongata bilaterally. After fenestration of the cyst wall and tumor removal, the clinical symptoms ameliorated. We recommend that where a foramen magnum tumor coexists with an arachnoid cyst of the posterior fossa, the tumor should be removed after shrinking the cyst to obviate the need for brainstem retraction.

Aged↗
PubMed1992

Comparison of spatial resolution between tomographic images and ghosts in rotational panoramic radiography: the effect of the first slit width.

Rotational panoramic radiography projects the object placed within the focal trough as tomographic images with minimal distortion. However, even if an object is within the focal trough, the sharpness of the image is affected by the position of the object, the difference in the relative speed of the X-ray source against the film and the difference in the direction of rotation. In this study, spatial resolutions of ghosts and tomographic images were compared. Ghosts, as well as tomographic images, were obtained from the object placed in the focal trough. The effects of the width of the first slit, a major parameter affecting image quality, were the primary concern in this study. With regard to ghosts, the influence of the position of object, in terms of central, buccal and lingual regions the focal trough, was also analyzed. The target of analysis was the mandibular ramus region. An Orthopantomograph OP5, a conventional panoramic apparatus, was used. An X-ray test chart, X-ray beams, and H-D curve were prepared for calculation of the Modulation Transfer Function (MTF), and the slit method using the Fourier transforms was applied. When the width of the first slit was changed displacement of MTF curves was most remarkable for the superimposed tomographic image which was scanned 10 mm posterior to the X-axis connecting the right and left lateral rotation centers. For reduction of the spatial resolution of ghosts, it was found effective to use a wider slit and place the object at a position lingual to the central plane.

Artifacts↗
PubMed1991

Effect of nitric oxide on L-[3H]glutamate binding to rat brain synaptic membranes.

Nitric oxide (NO), which is spontaneously generated from sodium nitroprusside, was shown to inhibit L-[3H]glutamate binding to rat brain synaptic membranes in a concentration-dependent manner. The L-glutamate binding inhibited by NO, was largely recoverable by the addition of hemoglobin, a scavenger of NO, to the assay medium. These results suggest that NO may play an important role in the modulation of excitatory neurotransmission through direct interaction of L-glutamate binding to its physiological synaptic membrane receptors.

Animals↗