Biomedical subjects

H Yamaguchi

Publications and source records attributed to H Yamaguchi.

At least 865 records · Page 48Linked to original sources

PubMed1993

Early detection of coronary reperfusion by rapid assessment of plasma myoglobin.

We assayed plasma myoglobin and creatine kinase to elucidate the usefulness of rapid assessment of myoglobin for detecting coronary reperfusion in 31 patients with acute myocardial infarction. Reperfusion was achieved in 20 patients by thrombolytic therapy or angioplasty, and it was not in 11 patients. Blood sampling was performed before and 43 +/- 15 (+/- SD) min after the start of treatment. In the reperfused group, blood samples were obtained before and 26 +/- 10 min after reperfusion. Myoglobin was assayed by a new quantitative test based on latex agglutination turbidimetry which required an assay time of 10 min. After treatment, the rate of increase of plasma myoglobin was significantly higher than that of plasma creatine kinase in the reperfused group (9.7 +/- 9.5 and 2.8 +/- 1.6-fold), but not in the occluded group (1.8 +/- 0.6 and 1.5 +/- 0.3-fold). When a 3.0-fold or greater increase in myoglobin (1.9-fold or greater increase in creatine kinase) was taken as evidence of coronary reperfusion, the sensitivity and specificity were 95% and 100% (70% and 82% in creatine kinase), respectively. In conclusion, using the rate of increase of myoglobin, as measured by latex agglutination turbidimetry, coronary reperfusion can be diagnosed within 1 h after reperfusion.

Adult↗

PubMed1993

Multiple primary carcinoma of the oesophagus.

A retrospective evaluation of 239 patients with primary oesophageal carcinoma who underwent oesophagectomy without preoperative treatment revealed 45 cases (18.8%) of multiple primary oesophageal carcinoma (MPEC). The average age of the patients with MPEC was significantly lower than that of patients with single primary oesophageal carcinoma (SPEC) (P = 0.005). The incidence of association with pharyngeal malignancy was higher in patients with MPEC than in those with SPEC (P = 0.080). The number of patients in the category representing a combination of heaviest alcohol and cigarette use was significantly higher in the MPEC patients (P = 0.035). The high incidence of MPEC points to a need for careful checking of the oesophagus at the time of surgical treatment for oesophageal carcinoma. Low age at onset, a combination of heavy smoking and drinking, and association with pharyngeal malignancy are considered to be high-risk factors for MPEC.

Aged↗

PubMed1993

Pushing exercise program to correct glottal incompetence.

A voice therapy program using pushing exercises to correct glottal incompetence is described. The program utilizes various types of instrumentation to determine whether or not a given patient is likely to benefit from the treatment. The program also provides feedback of target voices. Three cases with incomplete glottal closure and subsequent vocal dysphonia characterized by an asthenic breathy quality are used to illustrate the program. Details of the program, termination criteria, and problems and precautions learned from treating 29 patients over a 3-year period are presented.

Aged↗

PubMed1993

Study of morphological manifestations of pulmonary arteries in experimental pulmonary hypertension provoked by administration of long-term, low-dose Na2EDTA--especially in aneurysmal changes and plexiform-like lesions.

In a previous paper (Yamaguchi et al. 1991) we informed that the administration of 1 ml. of 6% Na2EDTA every day intraperitoneally for two months led to the death of the guinea pigs, and autopsy revealed that the causes of death were right ventricular rupture ("rupturing") or severe right heart failure which was observed as extraordinary dilatation of the right ventricle ("non-rupturing"). The two different morphological causes of death were site dependent on the constriction of the pulmonary arteries, and the pulmonary arteries showed a fairly unique morphology. To analyze the morphological manifestations of the pulmonary arteries which were observed in the cases of extraordinarily dilated and thin ventricular luminal wall a decreased dose of Na2EDTA was administered every day for six months in order to maintain a reasonably long life of the animals through prevention of right ventricular rupture. In addition to the morphological manifestations reported in the previous paper, the longer term constriction of pulmonary arteries provoked aneurysmal changes, partially or totally, and the plexiform-like lesions which have been thought to be the most characteristic morphological one in pulmonary hypertension. The formative mechanisms are discussed.

Aneurysm↗

PubMed1993

Experimental pulmonary hypertension induced by constriction of the pulmonary arteries resulting in rupture or extraordinary dilatation of the right ventricle after administration of a little amount of Na2EDTA.

Our earlier studies on the hypocalcemic condition have focused on the histological distortion of the organ structure with the removal of the calcium ion from the molecular structure of acid mucopolysaccharides (AMPs); resulting in the sol-gel diversion of the matrix. Bivalent cationic materials including calcium are related not only to function but also to structural alteration of the living organism (Yamaguchi et al. 1978, 1981, 1982, 1985, 1991). The ionic shift from the structural phase to the functional phase induced a number of morphological distortions of the various organs. In the present paper, starting our research from a different experimental viewpoint, we decreased the Na2EDTA dose used to prevent the conventional typical tetanic shock which sometimes results in animal death. We expected this decreased dose to induce mild constriction of muscle cells. In our experiment, administration of a small amount of Na2EDTA intraperitoneally provoked animal death after 10 days to two weeks over a two-month period. In the initial phase of 10 days to two weeks, rupture of the right ventricular wall along the septum occurred at an anterior angle with moderate right ventricular dilatation and a remarkably thin ventricular wall. Characteristic of these cases was elastosis between the medial smooth muscle cells of the main pulmonary arteries accompanied by a severe degree of constriction. On the other hand, demonstrated in the delayed cases of between more than two weeks to two months there was severe dilatation of the right ventricular lumina with paper-like thinness of the wall. In these cases, the main pulmonary arteries showed rather slight constriction with scarce elastosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Filtration through a polyester white cell-reduction filter of plasma-poor platelet concentrates prepared with an acetate-containing additive solution.

It is of practical importance to known whether the adsorption of platelets and contaminating white cells (WBCs) by the WBC-reduction filter is altered when platelet concentrates (PCs) are prepared in a plasma-poor condition with an acetate-containing additive solution (Seto sol). Plasma-poor PCs with 11-percent residual plasma were prepared from apheresis platelet-rich plasma by using a sterile docking device with steam-sterilized Seto sol. Seto sol contains 115 mM (115 mmol/L) NaCl, 4 mM (4 mmol/L) KCl, 3 mM (3 mmol/L) MgCl2, 10 mM (10 mmol/L) Na3PO4, 15 mM (15 mmol/L) acetate, 3 mM (3 mmol/L) Na3 citrate, and 10 mM (10 mmol/L) glucose (pH 7.1). The solution was steam-sterilized under nitrogen gas. On Days 1 and 5, pooled Seto sol PCs (2.4 x 10(11) platelets) were filtered with a polyester filter at a flow rate of 10 mL per minute. The WBC-removal rate was over 99.9 percent with a platelet recovery of 88 percent following Day 1 filtration. These values were very similar to those of plasma PCs, and 84-percent recovery was achieved following Day 5 filtration. However, when 1 unit of Seto sol PCs with half the number of platelets was filtered with the polyester filter, platelet recovery was about 16 to 17 percent less than that of plasma PCs. Platelet quality was maintained if pooled Seto sol PCs were filtered on Day 1 and stored for over 4 days. Filtration did not alter platelet function in 1-day-old or 5-day-old Seto sol PCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗

PubMed1993

Direct demonstration of the essential role of the intramolecular high-mannose oligosaccharide chains in the folding and assembly of soybean (glycine max) lectin polypeptides.

We investigated the role of the intramolecular high-mannose oligosaccharide chains in the folding and assembly of soybean lectin polypeptides. Soybean lectin, dissociated into subunits and completely denatured in 6 M guanidine hydrochloride, was quantitatively reconstituted to the active tetrameric structure by simple dilution. However, neither the activity nor the tetrameric structure was regained in the presence of 100 microM of an asparagine-linked oligosaccharide, Man9GlcNAc2Asn, having the same structure as that of the sugar chains of soybean lectin. Besides, the same concentration of this glycopeptide even dissociated, although only gradually, the native lectin into subunits. On the other hand, the deglycosylated subunits had no ability to regain the activity or the tetrameric structure. The present study provided for the first time direct evidence of the essential role of the intramolecular high-mannose oligosaccharide chains in the proper folding and assembly of glycopolypeptides.

Carbohydrate Sequence↗

PubMed1993

Role of intramolecular high-mannose chains in the folding and assembly of soybean (Glycine max) lectin polypeptides: studies by the combined use of spectroscopy and gel-filtration size analysis.

It was previously reported [Nagai, K. & Yamaguchi, H. (1993) J. Biochem. 113, 123-125] that intramolecular high-mannose chains are essential for reconstitution of soybean lectin from denatured subunits. To obtain more detailed information on the role of the intramolecular high-mannose chains in the folding and assembly of soybean lectin polypeptides, the effects of asparagine-linked oligosaccharides, Man9GlcNAc2Asn (M9-Asn) and Glc1-3Man9GlcNAc2Asn (GM9-Asn), on the reconstitution of soybean lectin from denatured subunits were examined by comparison with the denaturation features of the lectin with varying concentrations of guanidine hydrochloride. The combined use of spectroscopy and size-analysis by gel filtration revealed that both the folding and assembly of denatured subunit polypeptides were completely prevented in the presence of 300 microM M9-Asn, whereas the same concentration of GM9-Asn only interfered with the polypeptide assembly, exhibiting no significant effect on the polypeptide folding. These results, considered together with those in the previous report, indicate that the sugar branch Man alpha 1-2Man-alpha 1-2Man linked to the 3 position of the beta-mannosyl residue of the high-mannose chains functions in the folding of the subunit polypeptides, and that other branches participate in the subunit assembly.

Asparagine↗

PubMed1993

Role of local pancreatic blood flow in development of hemorrhagic pancreatitis induced by stress in rats.

Our previous data showed that the pancreatitis induced in rats by cerulein develops into hemorrhagic pancreatitis following water-immersion stress. The present study examined the effects of water-immersion stress and high doses of cerulein (intraperitoneal injection) on pancreatic blood flow. Five hours of water-immersion stress reduced the local pancreatic blood flow to approximately 30% of the initial value (253.75 +/- 12.58 ml/min/100 g) without causing any histological alterations. Blood flow was decreased as early as 1 h after the immersion and reached the lowest value (30% of initial value) 3 h after the immersion. The administration of 40 micrograms/kg body wt cerulein as two intraperitoneal injections reduced the pancreatic blood flow by 40% 5 h after the first cerulein injection. The injections of cerulein combined with water-immersion stress did not reduce the pancreatic blood flow more than did water-immersion stress alone. The systemic blood pressure was unaffected during 5 h of water immersion after the cerulein injections. These findings suggest that in rats the stress-induced decrease of local pancreatic blood flow may not produce pancreatitis, but may aggravate an existing acute pancreatitis.

Amylases↗

PubMed1993

Acute pancreatitis induced by cyclosporin A under stimulation of pancreas by caerulein.

Our purpose was to investigate enzymatically and morphologically the acute effect of the immunosuppressive agent cyclosporin A (CsA) on the exocrine pancreas of rats. The intravenous injection of CsA 10 and 20 mg/kg body weight (BW) increased the content of pancreatic amylase and protein and decreased the content of pancreatic DNA. Histologically, we observed intraacinar vacuolization and individual cell necrosis. Under stimulation of the pancreas by two intraperitoneal injections of caerulein 5 micrograms/kg BW at 1-h intervals (which did not induce any evident change in the pancreas), CsA induced a significant increase in serum amylase and in pancreatic wet weight in a dose-dependent manner. CsA at doses of 10 and 20 mg/kg BW produced a significant increase in the content of pancreatic amylase and protein. Macroscopically, we observed marked pancreatic edema, venous dilatation, and patchy hemorrhage. Histologically, there were significant differences in the severity of intra-acinar vacuolization, interstitial edema, neutrophil infiltration, individual cell necrosis, and hemorrhage, severity of which was dose dependent. Pancreatic ductal erosion was particularly marked following treatment with CsA 20 mg/kg BW. These findings indicate that CsA accelerates abnormal pancreatic enzyme secretion and suggest that the therapeutically recommended doses of CsA can induce acute pancreatitis under stimulation of the pancreas.

Acute Disease↗

PubMed1993

Rapid diagnosis of gastric malignant lymphoma from biopsy specimens: detection of immunoglobulin heavy chain rearrangement by polymerase chain reaction.

The endoscopic appearances of the gastrointestinal lymphomas differ widely, and it is often difficult to make the distinction between a benign lymphoproliferative disorder and a malignant lymphoma even with a histologic evaluation. Since almost all primary malignant lymphomas of the gastrointestinal tract are of B-cell origin, the confirmation of monoclonality in immunoglobulin (Ig) is helpful for differential diagnosis. Rearrangements of the Ig heavy chain gene were examined by polymerase chain reaction (PCR) analysis in frozen biopsy specimens of human stomach. The sensitivity of the analysis was sufficient to detect even a 5% clonal B-cell proliferation and results could be obtained within 17 h. In a clinical investigation, seven of eight cases (88%) of primary gastric malignant lymphoma showed a single band in polyacrylamide gel electrophoresis (PAGE) after PCR, suggesting a monoclonal proliferation of B-cell lineage. By contrast, all seven cases of reactive lymphoreticular hyperplasias showed a broad smear pattern in PAGE, which is thought to reflect polyclonal proliferation. None of the lymphocytes infiltrating around gastritis (7 cases), gastric ulcers (12 cases) and gastric carcinomas (15 cases) showed a monoclonal proliferation pattern. These findings suggest that detection of monoclonality in Ig heavy gene rearrangement by PCR is useful for the differential diagnosis of B-cell lymphoproliferative diseases in the gastrointestinal tract.

Base Sequence↗

PubMed1993

A human monoclonal antibody that detects HLA-A1, A23 and A24 antigens.

We report the production and characterization of a human monoclonal IgM (mu, kappa) antibody recognizing the HLA A1, A23 and A24 antigens. B lymphocytes obtained from a multiparous Japanese woman were transformed in vitro by Epstein-Barr virus, screened with an immune adherence assay, and fused with a murine myeloma cell line, P3-X63-Ag8.653. After subcloning by limiting dilution three times, a stable antibody-secreting hybridoma cell line, 4-35-7, was identified. The culture supernant had a titer of 1:32-64 against each of A1-, A23- and A24-positive lymphocyte panels, and showed complete correlation (r = 1.00) with the A1, A23 and A24 antigens on a lymphocyte panel of 287 unrelated, class I HLA-typed donors by the NIH cytotoxicity assay. Monoclonality of the antibody was ensured by Southern blot analysis of the human immunoglobulin heavy chain gene of 4-35-7. In view of the published data on HLA class I nucleotide sequences, the antibody may recognize an antigeneic determinant including two amino acid residues, Asp-166 and Gly-167, in the alpha 2 helix of the class I molecule that are specific for A1, A23 and A24 so far analyzed.

Animals↗

PubMed1993

Granulocyte colony-stimulating factor potentiates anti-Candida albicans growth inhibitory activity of polymorphonuclear cells.

Granulocyte colony-stimulating factor (G-CSF) stimulates a subset of granulocyte colony forming cells and when administered to neutropenic individuals results in recovery of blood neutrophil numbers to normal levels. Therefore, G-CSF may be a useful therapeutic agent for infections in immunocompromised hosts. However, to date there has been only limited information that G-CSF activates the antimicrobial activity of neutrophils. In the present study, we found that recombinant G-CSF promotes the anti-Candida albicans activity of normal human blood polymorphonuclear (PMN) cells in vitro using both a 3H-glucose uptake procedure and a Candida colony counting assay. As little as 0.1 ng/ml G-CSF induced significant anti-Candida activity in the PMN cultures. G-CSF treatment also enhanced superoxide anion production by the PMNs in response to f-MLP as determined by the superoxide dismutase inhibitable cytochrome C reduction method. Such results show that G-CSF can promote the antimicrobial activity of peripheral blood PMNs against C. albicans.

Candida albicans↗

PubMed1993

[A case of encephalopathy accompanying Mycoplasma pneumoniae pneumonia in an adult].

We experienced a 39-year-old male who developed neurological complication during a course of Mycoplasma pneumoniae pneumonia. The diagnosis of M. pneumoniae pneumonia was made on the basis of elevation of specific antibody (CF) titer in convalescent serum. Electroencephalogram showed diffuse damage in the brain, but no other abnormalities were not found on brain CT-scan and MRI. In the cerebrospinal fluid, the number of cells did not increase and the M. pneumoniae CF titer was not elevated. From these results, we concluded that encephalopathy in this patient was raised by an allergic reaction of the brain tissue to M. pneumoniae antigen. Until now, encephalitis or meningoencephalitis accompanied with M. pneumoniae infection has been reported by many investigators, but reports on encephalopathy due to M. pneumoniae are few. Therefore, we reported herein a case of encephalopathy following Mycoplasma pneumoniae pneumonia with several references.

Adult↗

PubMed1993

Augmentation of murine tumor necrosis factor production by amphotericin B in vitro and in vivo.

Murine peritoneal macrophages were preincubated with amphotericin B (AMPH) and were then stimulated with bacterial lipopolysaccharide or streptococcal preparation (OK432). These macrophages produced a large amount of tumor necrosis factor. When administered to mice, the priming activity of amphotericin B for tumor necrosis factor production in vivo was also observed.

Amphotericin B↗

PubMed1993

Two mechanisms of butenafine action in Candida albicans.

The mechanism of action of a new benzylamine antimycotic, butenafine hydrochloride, was studied in Candida albicans by using the thiocarbamate antimycotic tolnaftate as a reference drug. Butenafine completely inhibited the growth of a test strain of C. albicans at 25 micrograms/ml and was cidal at 50 micrograms/ml. Tolnaftate did not show any growth-inhibitory activity up to 100 micrograms/ml. Both butenafine and tolnaftate inhibited squalene epoxidation in C. albicans, with 50% inhibitory concentrations being 0.57 and 0.17 microgram/ml, respectively. Butenafine, but not tolnaftate, induced the release of appreciable amounts of Pi from C. albicans cells at 12.5 micrograms/ml. This effect of butenafine was augmented when the cells were pretreated with tolnaftate. The results suggest that the direct membrane-damaging effect of butenafine may play a major role in its anticandidal activity and that the drug-induced alteration in the cellular sterol composition renders the cell membrane more susceptible to the membrane-damaging effect of this drug.

Acetates↗

PubMed1993

Change in K+ current of HeLa cells with progression of the cell cycle studied by patch-clamp technique.

The K+ channel of HeLa S3 cells in metaphase was analyzed by inside-out and whole cell patch-clamp techniques. The channel had the characteristics of strong inward rectification, small conductance (22 pS at -100 mV), and dependence on intracellular Ca2+. We investigated the cell cycle dependency of the channel, using cells synchronized by harvesting them at the mitotic stage. The cell capacitance increased gradually with increases in the cell volume toward the S phase. The inward K+ currents through the channel at fixed membrane potentials were highest in early G1 and then decreased with time to a minimum in the S phase, increasing again in the M phase. The permeabilities at fixed membrane potentials were also highest in early G1, decreased to minima in the S phase, and increased again toward the next mitosis. In contrast, mean amplitude and the open probability of the single channel at a fixed membrane potential (-60 mV) did not change significantly during the cell cycle. Therefore the capacitance increases with progression of the cell cycle, whereas the permeability decreases from early G1 to an apparent minimum in the S phase. These changes may be caused by cell cycle-dependent changes in the number of channels.

Calcium↗

PubMed1993

Free cytosolic Ca2+ measured with Ca(2+)-selective electrodes and fura 2 in rat mesenteric resistance arteries.

Free cytosolic Ca2+ was measured with sub-micrometer-tip, double-barrelled, Ca(2+)-selective electrodes and fura 2 in rat mesenteric resistance arteries. The purpose was to establish intracellular free Ca2+ concentration ([Ca2+]i) values in resting and stimulated vessels. Isolated vessels were mounted for isometric force measurements. Measured with electrodes, mean [Ca2+]i was 115 and 708 nM under resting and norepinephrine-activated conditions, respectively. Fura 2 was calibrated intracellularly including determination of the intracellular dissociation constant (Kd) of the fura 2:Ca2+ complex. The intracellular Kd was 342 nM. With this value of Kd, fura 2 measurements of mean [Ca2+]i were 129 and 537 nM under resting and norepinephrine-activated conditions, respectively. The values measured with the two techniques were thus in good accordance.

Animals↗