Search PubMed⌕ Search

Biomedical subjects

K Imamura

Publications and source records attributed to K Imamura.

At least 253 records · Page 14Linked to original sources
PubMed1988

Appearance of interfrontal bone in chimeric mouse.

The incidence of the interfrontal bone in mice differs between strains, being high in C57BL/6 and low in BALB/c. In the present study, aggregation chimeras (C57BL----BALB) were examined to reveal whether or not genetically different cells interact in the morphogenesis of the interfrontal bone. In C57BL/6 mice, large interfrontal bones appeared in almost all animals, whereas in BALB/c and reciprocal F1 crosses (C57 BL x BALB, BALB x C57BL), large bones were seldom observed while tiny bones at the inside of the skull appeared at a low incidence. In contrast, chimeras frequently had large interfrontal bones, the size of which varied considerably. Based on the degree of chimerism as determined by coat color mosaicism and glucose phosphate isomerase (G PI) analysis of tissues, the chimeric mice containing a dominant population of C57BL cells had large interfrontal bones, while those with a predominance of BALB cells had no bone or had tiny ones. The results indicated that the appearance of the interfrontal bone corresponded with the population of the C57BL cells occupying the skeletal rudiment, and that there was no interaction between C57BL cells and BALB cells in the morphogenesis of the interfrontal bone.

Animals↗
PubMed1988

[Local irritation studies of cefodizime sodium].

Four local irritation studies of cefodizime sodium (THR-221), a new developed cephem-type antibiotics, were carried out with NZW rabbits. 1. In eye irritation test, 25% THR-221 water solution had no irritancy on eye mucosa in rabbits. 2. In single injective intramuscular irritation study, regardless of solvents (water or 0.5% lidocaine), 25% THR-221 solution had irritancy equal to 0.75% acetic acid. But recovery process of the muscle injured with THR-221 was faster and better than with 0.75% acetic acid. 3. In five days injective muscular irritation study, the irritancy of 25% THR-221 water solution on the muscle was milder than that of CTT or CET. Histopathological damage with THR-221, necrosis/degeneration of muscle fibers and edema/hemorrhage in interstitium etc., were well recovered. 4. In vessel irritation study, 10% or more THR-221 water solution had irritancy on ear vessel. THR-221, as same as CTT, caused organized thrombi and inflammation at the surrounding area. The degree of irritation of 20% THR-221 solution was slightly stronger than that of 20% CET, but weaker than that of 20% CTT. 5. In a clinical phase, it is to be desired that THR-221 like as CTT or CET shall be avoided repeated intramuscular or intravenous injections at the same site.

Animals↗
PubMed1988

[Effect of thrombin on hematuria after operation for benign prostatic hyperplasia].

The control of intra- and postoperative hemorrhage is as significant a problem following prostatectomy as postoperative urinary tract infection. We made a trial use of a solution of thrombin in continuous bladder lavage to control postoperative hemorrhage. A group of 21 patients with benign prostatic hyperplasia were treated by the thrombin lavage, with a group of 20 similar patients as controls. The treated group comprised 5 patients operated on by suprapubic, 11 by retropubic and 6 by transurethral prostatectomy, and the control group consisted of 6 patients operated on by suprapubic, 8 by retropubic, and 6 by transurethral prostatectomy. The thrombin lavage was, as a general rule, performed by lavaging the bladder with a solution of thrombin in physiological saline containing 100 units in each ml through an indwelling 3-way Foly catheter continuously for 24 hours following operation. There was no significant difference in the duration of macroscopic hematuria following operation by any operating technic between the control and the treated grove. The duration of microscopic hematuria was significantly shorter in the patients operated on by suprapubic prostatectomy and treated with thrombin than in the control group similarly operated on, and also tended to be reduced in the patients operated on by retropubic prostatectomy and treated with thrombin, compared with the controls similarly operated on. There was no significant difference in the duration between the patients operated on by transurethral technic. No particular adverse reactions to the thrombin lavage were observed.

Aged↗
PubMed1988

[Clinical effect of UFT in advanced renal cell carcinoma].

Single administration of 1-(2-tetrahydrofuryl)-5-fluorouracil (UFT) to patients with renal cell carcinoma with assessable lesions brought about 1 case each of complete response, partial response and no change, 3 cases of partial deterioration and the effective rate of 33.3%. As adverse effects, anorexia occurred in 1 of the 6 patients, but continual administration was possible by reducing the dose. The effective rate of UFT is high with few adverse effects, compared with the conventional chemotherapy. Therefore, UFT is considered to be an effective preparation for treating renal cell carcinoma.

Aged↗
PubMed1988

[Metastatic calcification associated with malignancy].

From 1975 to 1986, 15 cases (2%) of metastatic calcification associated with an underlying malignancy were found in a review of 702 autopsied cases with histories of malignancy. These underlying malignancies included 7 cases of lung cancer, 6 cases of malignant lymphoma, one case of breast cancer, and one of urinary bladder cancer. Squamous cell carcinoma was of the histological type most often associated with metastatic calcification in lung cancer, and ATL in malignant lymphoma. Hypercalcemia was found in 10 (83%) out of cases, and almost all were accompanied by renal dysfunction. Calcium deposits were most frequently observed in the kidneys and the lungs. It has been suggested that metastatic calcification in the lungs and kidneys of a patient with a history of malignancy showing hypercalcemia is sometimes accompanied by respiratory and renal dysfunction, causing the patient's condition to deteriorate.

Adult↗
PubMed1987

Expression of tumor necrosis factor receptors on human monocytes and internalization of receptor bound ligand.

Tumor necrosis factor (TNF) is a polypeptide produced by monocytes and macrophages. Although TNF receptors have been identified on a variety of cell types, previous studies have not determined whether these receptors also exist on monocytes. In the present work, highly purified recombinant TNF was labeled with 125I. The 125I-labeled TNF bound specifically to receptors on human monocytes and monocyte membrane preparations. A curvilinear Scatchard plot indicated the presence of TNF-binding sites with two different affinities. The results also indicate that receptor-bound TNF is rapidly internalized by monocytes and then degraded intracellularly. These findings are in concert with recent studies demonstrating that TNF immunomodulates monocyte function by an autocrine mechanism.

Binding Sites↗
PubMed1987

Reduced binocularity in the noradrenaline-infused striate cortex of acutely anesthetized and paralyzed, otherwise normal cats.

In anesthetized and paralyzed cats, the normal alignment of the visual axes is disturbed by paralysis of the eye muscles. Thus, the separation between paired receptive fields of binocular cells in visual cortex is increased (paralysis squint). This increased separation is normally tolerated by the majority of visuocortical cells, about 80% of them being binocularly driven (Hubel and Wiesel 1962). It was shown previously that neuronal plasticity in visual cortex can be enhanced in both normal adult cats (Kasamatsu et al. 1979) and kittens (Kuppermann and Kasamatsu 1984) by intracortical microinfusion of noradrenaline (NA). In the present study we tested whether the usual range of disparity produced by the paralysis squint is sufficient to induce ocular dominance changes in visual cortex of adult cats when the neuronal plasticity is enhanced by NA. NA was continuously infused into visual cortex throughout the experiments. The period of the paralysis squint varied from experiment to experiment between 9 and 47 h. We found: (1) These short periods were sufficient to produce a marked reduction in the proportion of binocular cells. (2) The proportion decreased linearly with increasing the duration of the squint period at a rate of 0.17 per 10 h up to about 22 h. (3) At longer durations the average binocularity remained at about 0.30 and could not be further reduced in the present paradigm. (4) The binocularity seemed to decrease with increasing separation of paired receptive fields. (5) Binocularity increased again toward the normal value after optical correction of the squint. (6) The amount of increased binocularity was linearly correlated with the duration of the period after the squint correction. (7) The binocularity increased at a rate of 0.18 per 10 h, reaching the normal value in less than 30 h. We thus concluded that if visuocortical plasticity is maintained at a high level through the continuous infusion of NA it is possible to change the ocular dominance distribution in the mature visual cortex by manipulations of the alignment of the visual axes even in the acutely anesthetized and paralyzed condition.

Anesthesia↗
PubMed1987

Projections of two subclasses of vomeronasal nerve fibers to the accessory olfactory bulb in the rabbit.

The organization of the projections of subclasses of vomeronasal nerve fibers to the accessory olfactory bulb was analysed using monoclonal antibodies generated against a homogenate of the rabbit olfactory bulb. Monoclonal antibody R2D5 labels all the somata of vomeronasal receptor cells in the vomeronasal organ as well as all their axons (vomeronasal nerve fibers). Another monoclonal antibody (R4B12), which has been shown to selectively bind and thus identify a subclass of olfactory nerve fibers, also labels a subclass of vomeronasal nerve fibers. The R4B12-positive subclass of vomeronasal nerve fibers project to the glomeruli in the rostrolateral part of the accessory olfactory bulb. The third monoclonal antibody (R5A10) recognizes a complementary subclass of vomeronasal nerve fibers projecting to the glomeruli in the caudomedial part of the accessory bulb. In contrast to the clearly segregated terminations in the accessory bulb, the two subclasses of vomeronasal nerve fibers are intermingled with each other in the vomeronasal nerve bundles. Retrograde labeling of vomeronasal receptor cell somata following injection of horseradish peroxidase within the rostrolateral (R4B12-positive) part of the accessory bulb indicates that vomeronasal receptor cells of this subtype are widely distributed in the vomeronasal sensory epithelium. These results demonstrate the heterogeneity of vomeronasal receptor cells and the specificity of projections arising from subclasses of vomeronasal nerve fibers to the accessory olfactory bulb.

Animals↗
PubMed1987

Induction of tumor necrosis factor expression and resistance in a human breast tumor cell line.

Tumor necrosis factor (TNF) is a polypeptide cytokine that is cytotoxic to some but not all tumor cells. The basis for resistance to the cytotoxic effects of this agent remains unclear. We have studied the development of TNF resistance in human ZR-75-1 breast carcinoma cells. ZR-75-1 cells have undetectable levels of TNF RNA and protein. However, TNF transcripts are transiently induced in these cells by exposure to recombinant human TNF. This induction of TNF RNA is associated with production of TNF-like protein in cell lysates and culture supernatants. Stable resistance to TNF-induced cytotoxicity develops when ZR-75-1 cells are exposed to increased concentrations of TNF. The TNF-resistant cells, designated ZR-75-1R, continuously express TNF transcripts and a TNF-like protein. Furthermore, ZR-75-1R cell supernatants contain cytotoxic activity that is abrogated by polyclonal antibody against TNF. The ZR-75-1R cells also possess TNF receptors that are occupied or down-regulated by the TNF-like protein. These findings thus suggest that (i) TNF induces TNF transcripts and production of a TNF-like protein in ZR-75-1 cells and (ii) resistance to TNF-induced cytotoxicity is associated with stable TNF expression.

Breast Neoplasms↗
PubMed1987

The Mexican hairless dog, its morphology and inheritance.

Some morphological characteristics of the Mexican hairless dog and their inheritance were investigated. The dogs examined were hairless and had defective teeth. From the results of mating experiments, an autosomal dominant semi-lethal gene was considered to be responsible for the hairlessness accompanied by defective teeth in the dog. The possible usefulness of the dog was also discussed.

Animals↗
PubMed1987

[Free methyltetrazolethiol concentrations in men subjected to intravenous administration of cephems with methyltetrazolethiol].

The disulfiram-like reaction due to cephems with methyltetrazolethiol (tetrazole) moiety was studied in biotransformation of these drugs. The serum tetrazole concentration was determined following intravenous administration of cefoperazone (CPZ) 1 g, latamoxef (LMOX) 1 g, or cefmetazole (CMZ) 2 g to patients suffering infections without liver dysfunction, and of CPZ 1 g to patients with liver cirrhosis. Tetrazole concentrations in normal patients were 0.5-2.0 micrograms/ml after 3 hours, and 0.14-0.26 micrograms/ml after 12 hours, and undetectable after 24 hours. On the other hand, the tetrazole concentration in cirrhotic patients was 0.143 +/- 0.07 micrograms/ml (mean +/- SD) even after 24 hours. Therefore, it is concluded that the disulfiram-like reaction due to cephems with tetrazole moiety closely related to the metabolism of these drugs in liver, and probably be caused by the inhibition of acetaldehyde dehydrogenase activity in liver by the free tetrazole group produced by the metabolism of these drugs in liver.

Aldehyde Oxidoreductases↗
PubMed1987

[The clinical study of 794 patients with an upper urinary tract stone analyzed by infrared spectroscopy].

During the 48-year period from January, 1938 to December, 1985, upper urinary tract stones obtained from 794 patients were analyzed by infrared spectroscopy in our Department. Their clinical manifestations were studied, mainly in relation to stone composition. The ratio of males to females was 3.0 to 1. In recent years, the incidence of females tended to increase. In the age distribution, twenties were most frequent followed by thirties together with fourties before 1965, but after 1966, the thirties were most frequent, and fourties and fifties increased. The composition of 794 stones was as follows. The most frequent type was calcium oxalate combined with calcium phosphate (43.1%), followed by calcium oxalate (39.8%) and calcium phosphate (9.6%). Magnesium ammonium phosphate stones were found in 1.6% and uric acid stones in 2.9%. Calcium oxalate stones, uric acid stones and oxalate-containing stones were found more frequently in males than in females. On the other hand, magnesium ammonium phosphate stones, calcium phosphate stones and phosphate-containing stones were found less frequently in males than in females. There was a high occurrence of calcium phosphate stones and uric acid stones in patients older than 60 years old. The occurrence of calcium oxalate stones and uric acid stones increased and that of phosphate-containing stones decreased after 1966. Most of the recurrent stones revealed the same or similar composition as the initial stones.

Adolescent↗
PubMed1987

[Cineradiographic study of wrist motion].

To make clear the kinematics of the wrist in flexion-extension and radial-ulnar deviation, a cineradiographic study was carried out on twenty normal hands. The intercarpal angles were measured on each picture of the cineradiogram. The relationship between the wrist angle and the intercarpal angles were calculated by a micro-computer giving a 5th degree regression curve. From the maximal dorsiflexion to the neutral position, the wrist moves in the radiocarpal joint more than in the midcarpal joint, while, from the neutral position to the maximal palmar flexion, the wrist moves more in the latter. From the neutral position to the maximal radial deviation, the wrist motion occurs in the midcarpal joint more than in the radiocarpal joint, while, from the neutral position to maximal ulnar deviation, the wrist motion occurs equally in the two joints. The movements of the carpal bones were regulated by the tension and the relaxation of the carpal ligaments.

Adult↗