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Biomedical subjects

T Imamura

Publications and source records attributed to T Imamura.

At least 379 records · Page 21Linked to original sources
PubMed1994

Primary retroperitoneal synovial sarcoma.

We present a patient with primary retroperitoneal synovial sarcoma which showed a monophasic fibrous pattern, the fourth such case to be described, and a review of the literature. Synovial sarcoma cells in the present case were stained positive for cytokeratin and epithelial membrane antigen (EMA), of which histology was differentiated from other spindle cell sarcoma with similar light microscopic features. Retroperitoneal synovial sarcoma is usually treated surgically, however only one of 16 cases identified in the literature survived five years after resection. Due to the high fatality rate, physicians should be alerted to the possibility of this disorder in the differential diagnosis of an abdominal mass.

Adult↗
PubMed1994

[A case of hypophosphatemia induced by intravenous administration of saccharated iron oxide].

An 81-year-old woman was hospitalised because of pneumonia in December 1989. In February 1991, an iliac bone biopsy was performed on the suspicion of disturbed bone metabolism due to chronic renal failure. Since she developed anemia due to continuous bleeding from the surgical wounds, saccharated iron oxide was administered beginning in March. Hypophosphatemia was noted 23 days after the beginning of administration. Due to the possibility of osteomalacia, active vitamin D was given but the hypophosphatemia persisted. Following an EDTA-2 Na load test performed to evaluate the reabsorption of phosphorus in the renal tubules, it was considered that the patient had a functional disorder of the parathyroid glands and that reabsorption of phosphorus was interrupted in the renal tubules. Furthermore, abnormal distributions of phosphorus seemed to occur in the same areas where sucrose was metabolized and iron was stored. Therefore, it was considered that these abnormalities induced hypophosphatemia following the intravenous administration of saccharated iron oxide. In addition to these actions, the possibility remained that phosphate absorption was inhibited in the small intestine by calcium lactate.

Aged↗
PubMed1994

[Donohue's syndrome (Leprechaunism)].

The syndrome of leprechaunism is characterized by the elfin-like face, hirsutism, acanthosis nigricans, absence of subcutaneous fat, and intrauterine and neonatal growth retardation. Most of the cases have severe insulin resistance with the mutation of the insulin receptor gene. In some cases, patient had two different mutations of the insulin receptor gene, and showed extremely severe insulin resistance. However, the genetic abnormalities responsible for the patient's phenotype, other than the insulin resistance, have not been found. Further study to define the additional genetic defects will be necessary to understand the abnormalities of this disorder.

Abnormalities, Multiple↗
PubMed1994

[Cor pulmonale].

Explore the source record for details and available documents.

Chronic Disease↗
PubMed1994

[Evaluation of Goldmann applanation tonometer with thin membrane water manometer].

In order to evaluate the accuracy of applanation tonometry, we prepared a thin membrane water manometer with a 0.07 mm thick HEMA soft contact lens and measured the internal pressure using a Goldmann type applanation tonometer (KOWA HA-1). The results were as follows. When the inner rims of the fluorescein ring were in contact with each other, the measured pressure value was lower than the theoretical value by about 5-15 mmHg; the higher the internal pressure, the larger the difference from the theoretical value. When the applanated condition was observed carefully, a dark ring about 0.2 mm in width could be seen inside the fluorescein ring. By applanating until the inner rims of this dark ring contacted each other, the theoretical value and the measured value matched approximately. Observing the contact surface by means of specular reflection, the applanated surface was located inside the dark ring, maintaining a circular shape with distinct boundary and this plane showed concentric circles or map-like color interference fringes. Newton's rings appeared on the boundary between this light interference surface and the dark ring. So we concluded that the true applanated area existed inside the dark ring and the inner rim of the fluorescein ring did not constitute an indicator of the boundary of applanated area.

Evaluation Studies as Topic↗
PubMed1994

[Improved perseveration with amantadine].

We report here 3 patients who showed marked improvement of clonic and intentional perseverations following the administration of amantadine. Patient 1 had a subacute encephalitis of unknown etiology. Magnetic resonance imaging documented lesions predominantly in the bilateral putaminal and frontal subcortical areas, and positron emission tomography revealed frontal glucose hypometabolism. Daily amantadine hydrochloride of 200 mg with or without 10 mg of trihexyphenidyl, reduced his clonic and intentional perseverations. The diagnosis of patients 2 and 3 was vascular dementia with multiple subcortical ischemic lesions, and single photon emission CTs showed reduced cerebral blood flow in the frontal lobes. Their clonic perseveration subsided and intentional perseveration disappeared after the administration of 150 mg of daily amantadine hydrochloride. Associated Parkinsonism and confusional state also improved in patient 1, but not in patients 2 or 3. Amantadine increases the pre-synaptic synthesis and release of dopamine, and works as a dopamine system activator. Our findings suggest that the disturbance of dopamine system, especially meso-limbofrontal projection, has some contributions to the perseveration of these patients.

Aged↗
PubMed1994

Pharmacokinetics and postmortem changes of cimetidine in body tissues.

Cimetidine concentrations in body tissues were pharmacokinetically examined, together with their postmortem changes, to assess the toxicological effect of this drug from the aspect of forensic medicine. For the pharmacokinetic study, rats were pithed at 0.5, 1.0, 2.0, 4.0 or 8.0 hours after an intravenous injection of the drug (33.3 mg/kg), and their tissue samples were immediately collected to be analyzed by high-performance liquid chromatography (HPLC). The concentrations of cimetidine in the blood and muscle decreased below the lower detection limit at 8 hours after the injection, while the drug could still be detected in the brain, lung, liver, kidney, spleen and adipose tissue. The ratios of the cimetidine concentrations in the muscle, lung and spleen to that in the blood were nearly constant until 4 hours after the injection, while those in the liver, kidney and adipose tissue increased as time elapsed. Postmortem changes of cimetidine concentrations were examined using the tissue samples collected 0, 1 and 2 days after death. There was no statistical significance in the postmortem changes in cimetidine concentrations in the body tissues over the two-day period of examination. The experimental results indicated that the muscle, lung and spleen together can serve as samples for toxicological analysis to evaluate the effect of cimetidine, regardless of various postmortem factors, including the availability of blood.

Animals↗
PubMed1993

Importance of Asp1191 for tyrosine kinase activity of the insulin receptor: functional difference of universally conserved Asp between tyrosine kinase and c-AMP dependent serine/threonine protein kinase.

Asp1191 of the tyrosine kinase domain in the insulin receptor is located in the almost perfectly conserved Ser-Asp-X-Trp motif of all tyrosine kinases, and the function of the motif has not been clarified. In this motif, Asp1191 is universally conserved in all protein kinases and corresponds to Asp220 in catalytic subunit of c-AMP dependent protein kinase. However, while other universally conserved amino acid residues are involved in catalysis, only Asp220 is not. To determine whether this motif was not also involved in catalysis, Asp1191 was replaced either by alanine, asparagine, or glutamic acid and Met1192 was replaced by valine. Asp1191-->Ala, Asn or Glu receptor lacked tyrosine kinase activity, while Met1192-->Val receptor showed normal kinase activity. These mutant receptors had no effect on insulin binding. These results suggested that the universally conserved Asp1191 in all protein kinases, which was not required for catalytic action of c-AMP dependent protein kinase, was essential for the tyrosine kinase activity of the insulin receptor.

Amino Acid Sequence↗
PubMed1993

Dissociated motor loss in the upper extremities. Clinical features and pathophysiology.

Dissociated motor loss occurring in the upper extremities with and without lower extremity myelopathy was evaluated in patients with cervical spondylosis. The presence of dissociated motor loss without attendant myelopathy was correlated with selected compression of the anterior nerve root in the lateral spinal canal, close to the intervertebral foramen. The clinical and radiologic feature differentiating these two dissociative syndromes were reviewed.

Arm↗
PubMed1993

Simultaneous determination of paraquat and diquat in human tissues by high-performance liquid chromatography.

A simple, sensitive, reliable, and economical method for simultaneous determination of paraquat dichloride and diquat dibromide in human biological materials has been developed, using high-performance liquid chromatography. The drugs were extracted from the sample with a Sep-Pak C18 cartridge and applied to a chromatograph with the internal standard, L-tyrosine. Paraquat and diquat were clearly separated on the octadecylsilica column with a mobile phase of 0.5% potassium bromide in 5% methanol solution, containing triethylamine (1 ml/l). The pH of the mobile phase was adjusted to 3-4 with 1.3 M phosphoric acid. Two ultraviolet wavelengths were selected, 256 nm for paraquat as well as the internal standard, and 310 nm for diquat. The calibration curves were linear in the concentration range 0.1-10 micrograms/g, and the lower limit of detection was 0.05 microgram/g. We used this method to examine the concentrations of paraquat and diquat in tissues of an individual at autopsy.

Adult↗
PubMed1993

Involvement of p53 gene mutations in human endometrial carcinomas.

Mutations in the p53 gene are associated with a wide variety of human malignancies. Point mutation in one allele and loss of the remaining one generally lead to inactivation of p53 protein. A high frequency of allelic losses corresponding to the 17p13.3 region that contained the p53 gene sequence was also noted in human endometrial carcinoma. Thus, in order to confirm involvement of the p53 gene in endometrial carcinogenesis, we searched for nucleotide sequence change in this gene in 42 endometrial carcinomas that had been subjected to previous LOH analyses. Using the polymerase-chain-reaction-single-strand conformation polymorphism (PCR-SSCP) method, we detected p53 gene mutations in 4 specimens. Two adenocarcinomas with allelic loss on 17p contained a mutant p53 gene in the allele that was retained. One specimen with a p53 gene mutation contained a 17q deletion but was uninformative for LOH on 17p. p53 gene mutation was also noted in the remaining stage-I carcinoma, though the 17p deletion was not detected in the previous LOH examination. However, 5 specimens with the LOH on 17p retained the wild-type p53 gene. In the remaining 33 specimens, both alleles of p53 gene seemed to be normal. The mutations observed in 2 specimens (cases 10 and 24), involving C-to-T and T-to-G substitutions, were located in a highly conserved region. However, the mutations identified in the remaining 2 cases (29 and 35) were at regions positioned outside conserved stretches.

Adenocarcinoma↗
PubMed1993

Role of macrophage tissue factor in the development of the delayed hypersensitivity reaction in monkey skin.

Delayed-type hypersensitivity (DTH) reaction is a cell-mediated immune response, characterized by fibrin deposition. To determine whether macrophage tissue factor (TF), an initiator of blood coagulation, was associated with the DTH reaction, TF expression on macrophages and resulting fibrin deposition at the site of DTH, induced in Bacille-Calmette-Guerin (BCG)-sensitized Japanese monkeys with intradermal administration of pure protein derivative of tuberculin (PPD), were examined immunohistochemically using monoclonal antibodies (MoAbs) against TF and fibrin. Most mononuclear cells, but not polymorphonuclear cells, in DTH reaction sites were TF-positive and were identified as macrophages by double-immunostaining using anti-TF and anti-macrophage MoAbs. Fibrin deposition was only observed around TF-positive macrophages in the stroma of DTH reaction sites, and the deposition was not seen in the periphery of other TF-positive tissues (epidermis, trichoepithelium, and blood vessels). The development of induration and the extent of fibrin deposition paralleled an increase of TF-positive macrophages in the DTH reaction sites. In PPD-injected skin sites of nonsensitized monkeys, neither TF-positive macrophages nor fibrin were seen but epidermis, trichoepithelium, and blood vessels were TF-positive. Moreover, the development of induration was inhibited by simultaneous administration of anti-TF MoAb and PPD into BCG-sensitized monkeys. These results suggest that TF expression on macrophages in the reaction site is a key factor for the DTH reaction, through the activation of blood coagulation, resulting in fibrin deposition.

Animals↗
PubMed1993

International comparison of odor threshold values of several odorants in Japan and in The Netherlands.

The purpose of this paper is to compare the published odor threshold values of six odorants. In Japan, all of the odor threshold values used in the Offensive Odor Control Law (enacted in 1972) were determined in an odor-free room (4 m3) by a trained panel (20 men, ages 30-45 years who were perfumers) who sniffed the odors directly and made absolute judgments of odor quality and intensity. In The Netherlands, sensorial odor concentration measurements were made with an olfactometer in a mobile sniffing car with eight panelists, four men and four women, ages 18-40 years. Such presentations are repeated with different dilution ratios. Comparison of the threshold data for the six different compounds given as the barely perceptible concentration level revealed striking similarities for hydrogen sulfide (in Japan 0.0005 ppm/in The Netherlands 0.0003 ppm), phenol (0.012/0.010), styrene (0.033/0.016), toluene (0.92/0.99), and tetrachloroethylene (1.8/1.2) but not for m-xylene (0.012/0.12). Such a similarity was not found with any other literature sources.

Adolescent↗