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Biomedical subjects

Y Kojima

Publications and source records attributed to Y Kojima.

At least 325 records · Page 18Linked to original sources
PubMed1991

Monoaminergic interaction in the central nervous system: a morphological analysis in the locus coeruleus of the rat.

The locus coeruleus of the rat is richly innervated by many aminergic neurons varying in amine content and in site of origin. There are adrenergic and noradrenergic neurons originating in the medulla oblongata, dopaminergic from the hypothalamus, serotonergic from the mesencephalon and also intrinsic noradrenergic neurons in the locus coeruleus complex. Of these, adrenergic and dopaminergic inputs appear relatively specific and powerful.

Animals↗
PubMed1991

Development of an integrated filing system for endoscopic images.

A new integrated filing system for endoscopic images has been developed, comprising a main image filing system and subsystems located at different stations. A hybrid filing system made up of both digital and analog filing devices was introduced to construct this system that combines the merits of the two filing methods. Each subsystem provided with a video processor, is equipped with a digital filing device, and routine images were recorded in the analog image filing device of the main system. The use of a multi-input adapter enabled simultaneous input of analog images from up to 8 video processors. Recorded magneto-optical disks make it possible to recall the digital images at any station in the hospital; the disks are copied without image degradation and also utilised for image processing. This system promises reliable storage and integrated, efficient management of endoscopic information. It also costs less to install than the so-called PACS (picture archiving and communication system), which connects all the stations of the hospital using optical fiber cables.

Analog-Digital Conversion↗
PubMed1991

Abnormal copper accumulation in non-cancerous and cancerous liver tissues of LEC rats developing hereditary hepatitis and spontaneous hepatoma.

We studied the copper concentrations in the non-cancerous and cancerous liver tissues of LEC rats with hereditary hepatitis and spontaneous hepatoma by atomic absorption spectrophotometry. Copper concentration in the non-cancerous livers of 29-month-old male LEC rats was comparable to that in the livers of LEC rats aged 2, 3 and 8 months whose hepatic copper concentrations were more than 40 times those of normal LEA rats. Copper concentration in spontaneously developed hepatocellular carcinomas of the 29-month-old male LEC rats was lower than that in the surrounding non-cancerous liver tissues, but was still more than 39 times that of 8-month-old male LEA rats. These findings suggest that in LEC rats an abnormal copper metabolism may be maintained during the process of hepatic carcinogenesis.

Age Factors↗
PubMed1991

Preparations, solution conformation and molecular structures of N,N'-ethylene-bridged dipeptides and their derivatives.

The solution conformations of novel dipeptides, methyl (2S, 3'S)-3-methyl-2-(2'-oxo-3'-isopropyl-1'-piperazinyl)-butanoate (EVV-OCH3), methyl (2S, 3'S)-3-phenyl-2-(2'-oxo-3'-benzyl-1'-piperazinyl) propionate (EFF-OCH3), and their derivatives (Boc-Gly-EVV-OH, Boc-Gly-EVV-Gly-OH, and Boc-Gly-EFF-OH), were studied by 1H NMR measurements and molecular mechanics calculations (1). The molecular structures of Boc-Gly-EVV-OH, Boc-Gly-EFF-OH, and the hydrochloride of EVV-OCH3 were determined by X-ray analyses. The conformations of the piperazinone rings and the side chains of these oligopeptides were clarified.

Chemical Phenomena↗
PubMed1991

Protection against endocarditis due to Staphylococcus epidermidis by immunization with capsular polysaccharide/adhesin.

BACKGROUND: Staphylococcus epidermidis is the principal pathogen in prosthetic valve endocarditis. The capsular polysaccharide adhesin (PS/A) has been shown to mediate attachment of bacteria to medical devices. In this study, we investigated the efficacy of active and passive immunization against PS/A in preventing S. epidermidis endocarditis in a rabbit model. METHODS AND RESULTS: Aortic valve vegetations were produced by inserting a Teflon catheter into the left ventricle through the right carotid artery. Bacteremia and endocarditis were then established by implanting in the left jugular vein a catheter that was attached to an osmotic pump and contaminated with S. epidermidis strain RP62A. During a 3-week study period, of 64 blood cultures taken every second or third day from six nonimmune rabbits, 54 (84%) yielded strain RP62A. In rabbits actively immunized with PS/A, eight of 60 blood cultures (13%) were positive (odds ratio 5.0, 95% CI, 2.0-12.3, p = 0.005). At death, all six nonimmune rabbits had infected vegetations that yielded 10(6)-10(11) colony-forming units (cfu)/g of vegetation, whereas only one PS/A-immunized rabbit had an infected vegetation. Immunization protocols designed to elicit antibody to teichoic acid but not to PS/A afforded no protection against bacteremia or endocarditis. Infusion of monoclonal antibody to PS/A through a catheter in the right jugular vein provided a level of protection against both bacteremia and endocarditis comparable to that produced by active immunization. In vitro, antibody against PS/A was opsonic for S. epidermidis. CONCLUSIONS: Immunoprophylaxis targeted at staphylococcal PS/A is a promising new approach to the prevention of prosthetic valve endocarditis.

Animals↗
PubMed1991

Spontaneous hepatic copper accumulation in Long-Evans Cinnamon rats with hereditary hepatitis. A model of Wilson's disease.

Long-Evans Cinnamon (LEC) rats, an inbred strain of a mutant rat isolated from Long-Evans rats, develop hereditary hepatitis. To elucidate the role of copper metabolism in the development of the hepatitis in LEC rats, we examined the copper concentration in the tissues and serum levels of copper and ceruloplasmin. Copper concentration in the liver of LEC rats was over 40 times that of normal Long-Evans Agouti (LEA) rats, while the serum ceruloplasmin and copper concentrations in LEC rats decreased significantly. The hepatocytes of LEC rats show steatosis in cytoplasm and pleomorphism of mitochondria, resembling the histologic features of the liver in Wilson's disease. These findings suggest that the hereditary hepatitis in LEC rats is closely associated with copper toxicity, and may be dealing with a rat form of Wilson's disease. Thus the LEC rats will provide a unique and useful animal model for clarifying the mechanism and for developing treatment strategies for Wilson's disease and other abnormal copper metabolism in humans.

Animals↗
PubMed1991

Identification by the sequential cell immunoblot assay of a subpopulation of rat dopamine-unresponsive lactotrophs.

The responsiveness to dopamine of PRL secretion from individual lactotrophs of female rats was investigated by the use of a newly developed sequential cell immunoblot assay. In this assay, PRL secretion from the same single lactotrophs that had been cultured on plastic coverslips was quantified before and after dopamine treatment by a combination of direct absorption of PRL secreted on protein-blotting transfer membranes, immunostaining, and microscopic image analysis. The assay was sensitive enough to detect 0.03 fg PRL/pixel and was specific for PRL. The range of PRL secretion from single pituitary cells in culture was 0.03-1.92 pg/cell.h. PRL secretion was increased with time of incubation and reached a maximum by 80-160 min. There was a significant correlation in PRL secretion from the same lactotrophs between the first and second 60-min incubations. When medium used in the second incubation contained no dopamine, amounts of PRL secreted during the second incubation period were 21-204% of those secreted during the first incubation period. Inclusion of 10(-8)-10(-6) M dopamine in the second incubation medium increased in a dose-dependent manner the proportion of lactotrophs whose PRL secretion was suppressed significantly compared with that during the first incubation period. However, PRL secretion from approximately 6% of the total lactotrophs was not suppressed even by dopamine at concentrations over 10(-6) M. The present study demonstrates that the sequential cell immunoblot assay is a useful means to quantify repeatedly hormone secretion from individual endocrine cells in culture. Furthermore, these results suggest that there is a subpopulation of rat PRL-secreting lactotrophs that are unresponsive to dopamine.

Animals↗
PubMed1991

Ultrastructure of abnormal boar spermatid: acrosomic fragmentation and vacuolization.

The fine structure of acrosomic abnormalities such as fragmentation and vacuolization of boar spermatids was studied in 4 different breeds (Duroc, Hampshire, Landrace and Yorkshire). These abnormalities initially appeared from the cap phase of spermiogenesis. The acrosome did not consist of serial sac covering the hemispherical nucleus, but only of a large acrosomic vesicle containing a dense granule and several pieces of cleaved proacrosomic vesicles attached to the anterior half of the round nucleus. The abnormality was frequently observed in the sister cells connected with the intercellular bridge. In the same seminiferous tubules, there was another abnormality on the acrosomic vacuolization of limited membrane system. Multiple vacuoles or vesicles were seen in the apical part of the nucleus in the cap phase, and also in the lower part of the equatorial segment of the acrosome phase.

Acrosome↗
PubMed1991

[Clinical study of intramuscular imipenem/cilastatin sodium in the field of obstetrics and gynecology].

The efficacy and the safety of intramuscular imipenem/cilastatin sodium (IPM/CS) were evaluated in 22 patients with obstetric and gynecologic infections. 0.5 g/0.5 g of IPM/CS was suspended in a lidocaine solution and administered in the gluteal muscle twice a day for 3-7 days. Nineteen patients with intrauterine infections were evaluable for the clinical efficacy and 22 for the safety. 1. Clinical efficacies were excellent in 6 patients, good in 11 and poor in 2, and the efficacy rate was 89.5%. Thirteen out of 14 patients who had not responded to treatments with other previously administered antibiotics showed excellent or good responses to IPM/CS. 2. Causative bacteria were eradicated in 5 patients, decreased in 2, unchanged in 3 and replaced in 3, with an eradication rate of 61.5%. 3. Among 22 patients treated with IPM/CS, an eruption and general itching were observed in 1 patient, but no abnormal laboratory test values were observed.

Adult↗
PubMed1991

Enhanced rectal and nasal absorption of human epidermal growth factor by combined use of the absorption promoter and the synthetic polymer in rats.

Previously, the presence of sodium carboxymethylcellulose (CMC Na) in addition to an absorption promoter, sodium caprate (C10 Na), in the dosing solution was found to be necessary for the enhancement of the rectal absorption of human epidermal growth factor (hEGF). In the present study, other synthetic polymers and absorption promoters were examined for their ability to enhance the rectal and nasal absorption of hEGF in rats. The effect of polymers in combined use with 100 mM C10 Na on the rectal absorption of hEGF was in the following order: 1% methylcellulose 1% hydroxypropylmethylcellulose 0.1% polyacrylic acid 1% CMC Na. Other absorption promoters such as N-lauroyl-alanine (C12-A) and dihydroxy-bile salts also enhanced the rectal absorption of hEGF in combined use with CMC Na. In order to confirm the increased rectal absorption of hEGF, the disappearance of hEGF from the rectal loop was examined. When hEGF in a 1% CMC Na solution (200 ug/kg) was administered in the rectal loop, the disappearance percent of hEGF during 60 min was 13.9% of the dose, although hEGF was not detected in the plasma. The presence of promoters such as 10 mM C10 Na or 15 mM C12-A in 1% CMC Na increased the disappearance percent to about 50% in a dosing range of hEGF from 100 to 500 ug/kg. On the other hand, a markedly enhanced nasal absorption of hEGF by 100 mM C10 Na was observed even in the absence of any polymer in a dising solution. However, addition of CMC Na into the dosing solution accelerated the rate of nasal absorption of hEGF in early phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Acrylic Resins↗
PubMed1991

[Diagnostic significance of urinary endothelin concentration].

We investigated plasma Endothelin concentration (s-ET) and urinary Endothelin concentration (u-ET) in eleven patients undergoing subtotal esophagectomy through r-thoracal and abdominal approach for esophageal cancer (nine men and two women). S-ET and u-ET, sodium excretions fraction (FENa), free-water clearance (CH2O, uric NAG Index, creatinine clearance rate (Ccr), primary water balance (PWB) and primary sodium balance (PNB) were measured during the perioperative period till the 7th day. Urinary Endothelin concentration in the postoperative 3 and 6 hours, and the 2nd postoperative day were significantly higher than preoperative value. No significant values were obtained in plasma Endothelin Highly significant correlations were obtained between urinary Endothelin concentration and FENa, CH2O, PWB and PNB. Furthermore, u-ET was well correlated with s-ET. We concluded that the measurement of u-ET may be useful as an indicator of renal tubular function and global renal functions with high sensitivity.

Adult↗
PubMed1991

[Postoperative pulmonary complication and surgical treatment of esophageal cancer in aged patients--evaluation of preoperative risk factors and postoperative management].

Because of the recent improvement in surgical technique and perioperative management, surgical treatment for esophageal cancer has become more extensive and thus even aged poor-risk patients can be operated on. However, transthoracic esophagectomy is still associated with a high rate of postoperative pulmonary complications. We analysed the preoperative findings and postoperative treatment in aged patients. During the decade starting from 1980, 151 patients with esophageal cancer were admitted to our clinic, there were 44 aged patients over 70 years. They were examined for preoperative risk factors associated with multiple organ functions. Our special attention was paid to postoperative pulmonary complications and hemodynamics that were monitored using the Swan-Ganz catheter. In the aged patients, there were highly abnormal finding in preoperative examinations, especially in cardiac, pulmonary and renal functions. Moreover, their cardiac index levels were lower and pulmonary vascular resistance levels were higher than those of the younger group. Postoperative pulmonary complications were induced frequently in the poor-risk patients who underwent transthoracic esophagectomy. However, the patients who were received infusion of dopamine and dobutamine were able to keep hemodynamic balance in the early postoperative period. Most patients with esophageal cancer are relatively old and have often multiorgan dysfunction. Transhiatal esophagectomy is a safe operation that is suitable for the treatment of aged poor-risk patients who can not tolerate thoracotomy. Choice of a surgical procedure for them should be carefully determined according to the systemic preoperative assessment of risk factors. Postoperative fluid therapy and respiratory management should be performed more strictly in the aged patient.

Aged↗
PubMed1991

Dislocation of the peroneal tendons in neonates and infants.

Twenty-three cases of dislocation of the peroneal tendons were found during routine orthopedic examinations of neonates and infants. All but one case was without foot deformity. One case was treated with a cast, and the others received no treatment. Follow-up observations revealed that the dislocations resolved spontaneously in almost all cases. This condition seems to be not as rare as had been previously considered. Dislocations of the peroneal tendons in neonates and infants without foot deformity should be untreated and allowed to resolve spontaneously.

Ankle Joint↗
PubMed1990

Cloning, sequence analysis, and expression of ligninolytic phenoloxidase genes of the white-rot basidiomycete Coriolus hirsutus.

Two cDNAs and two genomic DNAs coding for the allelic forms of the ligninolytic phenoloxidase were isolated from the white-rot fungus Coriolus hirsutus. The cloned genes were identified in genetic libraries by hybridization screening using four deoxyoligonucleotide probes which corresponded to the partial amino acid sequence of the purified enzyme. Each cDNA encoded the full-length of the phenoloxidase, a protein consisting of 499 amino acid residues, and its putative signal peptide of 21 amino acid residues. The nucleotide sequences of the two alleles differed by 18 single base changes within the open reading frames resulting in one amino acid substitution. Ten small introns interrupted both genomic DNAs as indicated by direct comparison with the corresponding cDNAs. Putative eukaryotic regulatory sequences, "CAAT" and "TATA," were observed in the 5'-flanking region of both genomic DNAs. Each of the phenoloxidase cDNAs was successfully expressed in an active form in Saccharomyces cerevisiae using the useful yeast expression vector YEp51.

Alleles↗