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Biomedical subjects

T Yamamura

Publications and source records attributed to T Yamamura.

At least 235 records · Page 13Linked to original sources
PubMed1992

[Pneumonia due to aspiration of povidone-iodine during anesthesia--a case report].

We report a case of pneumonia secondary to aspiration of povidone-iodine, which was used as an oral antiseptic. The patient was 17 y.o. female (body weight: 70 kg) who underwent a transsphenoidal resection of pituitary adenoma. Although she had a history of asthma during her childhood, no asthmatic attacks occurred for the past 10 yrs. After satisfactory anesthesia induction and tracheal intubation, 60 ml of 0.7% povidone-iodine solution was used to clean the oral cavity by a surgeon. Insufficient sealing by the cuff occurred after suturing the tube, which had made a needle hole in the cuff. Arterial oxygen saturation dropped to 90% and an increased resistance in the lungs was noted. The trachea was reintubated and she was transferred to the ICU. Her chest X-ray revealed signs of pneumonia and atelectasis in the right upper lobe. Mechanical ventilation with PEEP and periodical bronchial toilet were performed during her stay in the ICU for 42 hrs. A week was needed for the improvement of her X-ray findings. Although povidone-iodine is thought to be safe and affective antiseptics, severe complications from its aspiration may occur in patients whose airways are sensitive as observed in this case.

Adolescent↗
PubMed1992

[Measurement of functional residual capacity by sulfur hexafluoride washout].

An open circuit tracer gas washout method for measurement of functional residual capacity (FRC) during mechanical ventilation is described and tested. The system employed a piezo-valve for dispensing sulfur hexafluoride (SF6) gas, a fast response infrared SF6 analyzer, Servo 900-C ventilator and a computer. The piezo-valve unit delivers SF6 into the airway in proportion to instantaneous inspiratory flow so that inspiratory SF6 concentration was held constant regardless of the inspiratory flow pattern. The washin concentration was approximately 0.6% which was so low that the supply of other gases was hardly influenced. The amount of SF6 at the end of a washin was calculated during washout by signals of expired SF6 concentration and expired flow. The results obtained in model lungs were accurate and reproducible; mean difference (limits of agreements) was 14 +/- 48ml (M +/- 2SD) in the range between 0.5 and 3.0 liters. Comparison with helium dilution methods in 24 healthy subjects gave a regression equation: y = 0.98x + 56, r = 0.98. The mean difference of the values between the two methods was 21 +/- 142 ml (M +/- 2SD). The authors conclude that the system is quite useful in determining FRC of the patients under mechanical ventilation.

Functional Residual Capacity↗
PubMed1991

Protein kinase C activity as marker for colorectal cancer.

Protein kinase C (PKC) activity was measured in normal-appearing colonic mucosa from patients undergoing colonic resection. Comparisons were made between cases with and without colorectal cancers. PKC activity in cytosolic and particulate fractions was significantly reduced in patients with colorectal cancer: 40 +/- 9 and 114 +/- 29 (pmol/min/mg) respectively, compared with patients without cancer; 129 +/- 11 and 250 +/- 38 (pmol/min/mg) (p less than 0.05). Normal-appearing colonic mucosa in patients with cancer showed significantly decreased total PKC activities in the cytosolic and particulate fractions compared with those in patients without cancer (10 +/- 1 and 20 +/- 3 vs. 30 +/- 2 and 33 +/- 6) (pmol/min/g tissue) (p less than 0.05). The cellular distribution (% particulate fraction) of PKC activity in normal-appearing mucosa in patients with cancer (64%) was higher than in patients without cancer (49%) (p less than 0.05). OUr data suggest that PKC activity may be used as a biological marker of risk of developing colorectal cancer or risk of bearing an asymptomatic tumor.

Biomarkers, Tumor↗
PubMed1991

Altered protein tyrosine kinase levels in human colon carcinoma.

To further understand the molecular mechanisms and the biological indicators of colonic tumorigenesis, the authors examined tyrosine kinase activity in the cytosol and in the particulate fraction of the homogenates of specimens from 20 human colonic carcinomas and compared them with the adjacent normal mucosal tissues. Total protein tyrosine kinase activity could be precisely detected using miniphosphocellulose column purification and a synthetic peptide, Glu-asparagine (Asp)-alanine (Ala)-Glu-tyrosine (Tyr)-Ala-Ala-arginine (Arg)-Arg-Arg-glycine (Gly) (E11-G1), as an artificial substrate. Tyrosine kinase activity of colonic carcinoma and normal mucosa was reduced in the cytosol fraction whereas activity in the particulate fraction was elevated with respect to protein concentration. The average specific activity ratios were 1.95 +/- 0.27 (normal cytosolic/carcinoma cytosolic) and 0.57 +/- 0.01 (normal particulate/carcinoma particulate) for tyrosine kinase activity. Cellular distribution (% cytosol) of tyrosine kinase activity in normal mucosa and in carcinoma varied from 21.0% to 91.2% and from 7.0% to 61.4%, respectively. In nearly all cases the percentage of cytosolic tyrosine kinase activity in carcinoma tissues was lower than in normal tissues. There was no difference due to histologic type or the presence of adenomatous components. A significant decrease of cytosolic tyrosine kinases was correlated with Dukes' Stage A. With advancing Dukes' stage, the average specific activity ratios (normal cytosol/carcinoma cytosol) were decreased. This study indicates that colonic carcinogenesis might be associated with alterations in cellular levels of tyrosine kinase activity and that the average specific activity ratio (normal cytosol/carcinoma cytosol) had a possible correlation with colonic tumor growth.

Colonic Neoplasms↗
PubMed1991

Function after anoabdominal rectal resection and colonic J pouch--anal anastomosis.

Twenty-eight patients undergoing anoabdominal resection of the rectum with construction of a colonic J reservoir and eight patients without a reservoir were studied 2 years after surgery. Frequency of defaecation and daytime soiling were inversely correlated with the maximum tolerable volume of the colonic J pouch. The distensibility and threshold volume of those with a pouch were significantly greater than in those without a pouch 6 months or more after stoma closure. Anal resting pressure, squeeze pressure, anal canal length and a positive inhibitory reflex were similar in both groups. Anal resting pressure, squeeze pressure and pouch distensibility correlated with frequency of defaecation in the stable phase. Pouch construction may improve the patient's quality of life in the adaptation phase.

Adult↗
PubMed1991

Distribution of proteolipid protein and myelin basic protein in cultured mouse oligodendrocytes: primary vs. secondary cultures.

The distribution of proteolipid protein (PLP) and myelin basic protein (MBP) was examined in differentiating oligodendrocytes of primary and secondary mouse brain cell cultures by single- and double-label indirect immunofluorescence. In primary cultures, MBP and PLP were differentially located in oligodendrocytes. MBP became concentrated as fine punctate dots lining the edges of processes and as coarse grains in flattened sheet-like structures. PLP was distributed diffusely throughout cell bodies and processes but was limited to the perimeter of sheets and some processes within sheets. To compare the detailed distribution of PLP and MBP in the absence of underlying cells, a simple method for the growth of isolated oligodendrocytes in secondary cultures was developed. Cells were maintained in primary culture for 39-41 days, harvested by scraping, enriched for oligodendrocytes, and plated at low cell density. After 1 week, isolated oligodendrocytes had developed long processes and large flattened membranous sheets. MBP and PLP were differentially localized in these cell structures. The sheets contained fine-grained patches of MBP, which were surrounded by networks of MBP- processes. In contrast, PLP was initially seen throughout the cell bodies and processes. In older cultures, PLP became strikingly concentrated in curvilinear membranous profiles. The observations show that PLP and MBP are differentially located in cultured mouse oligodendrocytes. Furthermore, the precise distribution of these myelin-specific antigens is dependent on culture conditions.

Animals↗
PubMed1991

Lectin staining of neoplastic and normal background colorectal mucosa in nonpolyposis and polyposis patients.

A lectin histochemistry approach was adopted for comparative assessment of a colon cancer risk. Binding of Ulex europaeus agglutinin-I (UEA-I), peanut agglutinin (PNA), Griffonia simplicifolia agglutinin-II (GSA-II), and Dolichos biflorus agglutinin (DBA) was investigated in tumor and background tissue from a total of 34 adenoma and 44 cancer patients and compared with reaction patterns in control and familial adenomatous polyposis (FAP) patients. Adenoma patients with UEA-I positive rectal mucosa were found to have a 33.3 percent familial history of large bowel cancer, which was significantly higher (P less than 0.05) than the respective 4.0 percent figure for patients with negative rectal mucosa. In the cancer patients, an even stronger correlation was noted, with a 63.2 percent UEA-I positive family history association being recorded, as opposed to 4.0 percent in the negative rectal mucosa patients (P less than 0.01). Thus, the results suggest that, apparently, normal rectal background mucosa of individuals genetically at high risk for colon and rectal cancer demonstrates a specific lectin binding ability similar to that of FAP patients and that the simple method using UEA-I staining of rectal biopsy specimens can be of practical use in identification of high-risk colorectal cancer.

Adenoma↗
PubMed1991

Disappearance of hyperplastic polyposis after resection of rectal cancer. Report of two cases.

Since 1980, when the first description of hyperplastic polyposis of the colon appeared, 18 cases of hyperplastic polyposis have been reported in the literature. Only two of them bore colonic cancer. Here we add two cases of hyperplastic polyposis accompanying rectal carcinoma following cancer resection, in which residual hyperplastic polyps disappeared after resection.

Adenocarcinoma↗
PubMed1991

Hemodynamics in the prone jackknife position during surgery.

We examined the hemodynamic changes occurring with prone jackknife positioning during colorectal surgery. The operative procedure was restorative proctocolectomy with ileal J-pouch anal anastomosis in five patients with adenomatosis coli and six patients with ulcerative colitis and anoabdominal resection of the rectum with colonic J-pouch anal anastomosis in eight patients with rectal cancer. Nineteen patients (10 men and 9 women aged 41 +/- 19 years) were monitored with arterial and Swan-Ganz catheters during positioning. Measurements were obtained in the supine and prone positions (1 minute, 3 minutes), and the jackknife position (1, 3, 5, and 10 minutes), as well as before and after adoption of the Lloyd-Davies position (1, 3, 5, and 10 minutes). Turning the patient from the supine position to the prone position resulted in a significant decrease in the cardiac index (CI). However, following head-down rotation, the CI increased and returned to the value seen in the supine position (p less than 0.05). Heart rate (HR) slowed and mean arterial pressure (MAP) increased in the prone jackknife position. We concluded that the extent of the changes in cardiac function presented no serious problems.

Adenoma↗
PubMed1991

gamma-Aminobutyric acid enhances the tone of human internal anal sphincter.

The effect of gamma-aminobutyric acid (GABA) on the human internal anal sphincter was investigated. Cumulative applications of GABA produced concentration-dependent contractions (10(-8)-10(-5) M) of the isolated human sphincter. Pretreatment with bicuculline (GABAA antagonist) turned them to relaxation. Muscimol, a GABAA agonist, induced concentration-dependent contractions (10(-8)-10(-5) M); however, baclofen (GABAB agonist, 10(-8)-10(-5) M) promoted concentration-dependent relaxation of the strips. These results suggested that both excitatory GABAA receptors and inhibitory GABAB receptors exist in the internal anal sphincter. Oral administration of sodium valproate (1600 mg/day), a GABA transaminase inhibitor, enhanced the anal canal resting pressure in 10 normal volunteers. Anal manometry showed a significant elevation in tonus without affecting amplitudes or frequencies. These results indicated that endogenous GABA, which was increased by sodium valproate, produced elevations in the anal canal resting pressure through its specific receptors in the human internal anal sphincter.

Anal Canal↗
PubMed1991

Arterial tonometry for noninvasive, continuous blood pressure monitoring during anesthesia.

Arterial tonometry is a technique used to measure arterial blood pressure noninvasively. The authors developed a new tonometer system containing an array of 15 piezoresistive pressure transducers, a mechanical positioning system, signal conditioning and multiplexing electronics, and a display and control console. The authors evaluated the accuracy, reliability, and clinical acceptability of this system by comparing tonometric blood pressure measurements with intraarterial blood pressure measurements in 60 anesthetized patients. Blood pressure was measured intraarterially in either the right or left radial artery by a Gould P23XL calibrated transducer, whereas blood pressure was measured by tonometer at the radial artery of the other arm. The tonometric waveform was similar to the intraarterial waveform. Simultaneous tonometer and intraarterial systolic blood pressures of the 60 patients (3,036 data sets) had an overall regression coefficient, r = 0.97, and an equation, regression equation = 0.95X + 5.8. Similar values were obtained for mean and diastolic pressures. Regression analyses of the paired tonometric and intraarterial blood pressure values showed good correlations in both sexes and in ages ranging from 8 to 82 yr (r = 0.94-0.97). Mean absolute values of error (precision) for the systolic, mean, and diastolic measurements did not differ significantly among the five systolic, five mean, and four diastolic pressure groups and ranged from 3.6 to 6.6 mmHg, with negligible bias, with intraarterial pressure used as the reference. Bias for the various pressure groups was small: -0.9-3.6 mmHg for systolic; -3.0-0.7 mmHg for mean; and -2.1-4.5 mmHg for diastolic. The "limits of agreement" (mean difference +/- two standard deviations) were within an acceptable range for clinical anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Monoclonal antibodies against myelin proteolipid protein: identification and characterization of two major determinants.

This report describes the preparation and characterization of a panel of monoclonal antibodies (mAbs) against the myelin proteolipid protein (PLP). A Lewis rat was immunized with bovine proteolipid apoprotein and 27 mAbs were selected based on their reactivity against bovine PLP on enzyme-linked immunosorbent assays. Eleven mAbs recognized the PLP carboxyl-terminal sequence when tested against a panel of synthetic peptides in a solid-phase assay. A carboxyl-terminal pentapeptide (residues 272-276) was sufficient for antibody binding and the terminal phenylalanine residue was found particularly important. Deletion, modification, or replacement of this residue markedly reduced or obliterated antigen-antibody interaction. Nine mAbs reacted with a second antigenic determinant, residues 209-217, but these could be identified only by competitive immunoassays. This peptide was a more effective inhibitor than the longer peptides 202-217 and 205-221, suggesting that flanking residues may interfere with peptide-antibody interaction. Seven antibodies did not react with any of the synthetic peptides tested and their determinants remain unidentified. Immunoblot analysis showed that the mAbs reacted with both the PLP and the DM-20 isoforms. Twenty-three of the mAbs were of the immunoglobulin G2a or b isotype; the remaining antibodies were immunoglobulin M and all of these were specific for residues 209-217. Cultured murine oligodendrocytes were stained by most of the mAbs tested, but the most intense reactivity was observed with the carboxyl-terminus-specific mAbs. The immunocytochemical analyses demonstrate that the mAbs react with the native PLP in situ and show their potential usefulness for studies of the cell biology of myelin and oligodendrocytes.

Amino Acid Sequence↗
PubMed1991

Induction of experimental allergic encephalomyelitis by myelin proteolipid-protein-specific T cell clones and synthetic peptides.

Proteolipid protein (PLP) is the major protein of central nervous system (CNS) myelin. SJL(H-2s) mice immunized with a synthetic peptide corresponding to PLP residues 139-151 (HSLGKWLGHPDKF) develop acute experimental allergic encephalomyelitis (EAE). In the present study a T cell line and 4 clones were derived from SJL/J mice following immunization with this synthetic peptide. Severe clinical and histological EAE could be induced by adoptive transfer of the peptide-specific T cell line and 3 of 4 T cell clones. The T cell line/clones all responded strongly to PLP peptide 139-151 in in vitro proliferative assays. However, two different reactivity patterns emerged when truncated PLP peptides 141-150 and 141-149 were tested, suggesting that more than 1 epitope may be present within the PLP 139-151 determinant. To evaluate the encephalitogenic potential of the truncated peptides, we compared the ability of 2 truncated PLP peptides to induce EAE in vivo and proliferative responses in vitro. Immunization with PLP peptide 141-150 induced acute EAE in about 70% of mice tested, but PLP peptide 141-149 induced a comparatively mild form of EAE in 4 out of 9 mice tested. Lymph node cells from mice immunized with these peptides showed in vitro proliferative responses to each of the peptides, but the response to peptide 139-151 was always strongest. These combined in vivo and in vitro data further define the epitopes involved in PLP-induced EAE in SJL mice. Furthermore, the availability of multiple PLP-specific T cell clones will enable us to study the diversity of the T cell repertoire to PLP.

Amino Acid Sequence↗
PubMed1991

Triglyceride and glucose intolerance as a risk factor for coronary heart disease.

The electrophoresis of plasma lipoproteins frequently showed midbands between beta- and pre-beta-lipoproteins in survivors of myocardial infarction. There were increases in intermediate-density-lipoprotein (IDL) cholesterol and triglycerides with an increase in IDL cholesterol/triglycerides in the very-low-density-lipoprotein fraction, even if the increase in cholesterol was not so significant. Impaired glucose tolerance (IGT) was also frequently found in these patients. Among the patients with an apparently normal glucose tolerance, the coronary atherosclerosis scores judged by the American Heart Association reporting system on coronary angiography increased as the total insulin area by 75 g oral glucose tolerance test increased. The correlation between the atherosclerosis score and the insulin area was still significant even after adjustment for body mass index and plasma triglyceride level. Our data suggest that hypertriglyceridemia, IGT, and hyperinsulinemia may become independent risk factors for atherosclerosis in addition to cholesterol. Another study showed that the morbidity of coronary heart disease increased with an elevation of plasma triglyceride levels among patients with familial hypercholesterolemia.

Aged↗
PubMed1991

Recurrent mucocutaneous lymphocytic infiltration possibly associated with Epstein-Barr virus infection.

A 32-year-old man had a history of recurrent but self-healing necrotizing nodules on the face and oral mucosa. Histologically the lesion was composed of necrotizing foci surrounded with dense CD8+ T lymphocytic infiltration in the dermis. Laboratory examination showed marked blood CD8+ T lymphocytosis with a reversed ratio of CD4+/CD8+ of 0.11. Except for a very high titer of antibodies against Epstein-Barr-virus-associated antigens, no signs of infection were observed.

Adult↗
PubMed1991

Subcutaneous leiomyosarcoma developing in a radiation dermatitis.

A case of subcutaneous leiomyosarcoma developing in a skin affected by radiation dermatitis is presented. A 59-year-old patient had been suffering from radiation dermatitis induced by radiotherapy for a mediastinal tumor diagnosed at 24 years of age. Thirty-four years later, slow growing nodules developed in this lesion. Light and electron microscopic studies revealed that the tumor was a subcutaneous leiomyosarcoma. There is no previous report of a subcutaneous leiomyosarcoma developing in radiation dermatitis.

Dermatitis↗