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Biomedical subjects

Y Yamashiro

Publications and source records attributed to Y Yamashiro.

At least 145 records · Page 8Linked to original sources
PubMed1994

The effect of nasal CPAP on nocturnal reflux in patients with aperistaltic esophagus.

It has been shown that nasal continuous positive airway pressure (nasal CPAP) significantly reduces nocturnal reflux both in patients with sleep apnea and in patients without sleep apnea but consistent abnormal nocturnal reflux. The mechanism by which CPAP is thought to reduce reflux includes the elevation of the resting lower esophageal sphincter (LES) pressure. In this study, we tested the effect of nasal CPAP in two groups of patients with aperistaltic esophagus but with different resting LES pressure. Seven patients with scleroderma esophagus and six patients treated for achalasia were tested over a 48-h period. On the first night, the patients were untreated; on the second night, both groups received applied nasal CPAP at 8 cm H2O pressure. The percentage of time the pH < 4.0, the number of reflux events > 5 min, and the length of the longest reflux event were all significantly reduced in the patients with achalasia (p < 0.03), but not in the scleroderma group (p > 0.20). These results suggest that a residual resting LES pressure greater than that demonstrated by patients with scleroderma (> 10 mm Hg) may be necessary for nasal CPAP to affect nocturnal reflux.

Adult↗
PubMed1994

[Determination of globin synthesis studies using high performance liquid chromatography technique].

In vitro globin chain synthesis ratios (beta/alpha) were determined using high performance liquid chromatography (HPLC) in twenty-five alpha or beta-thalassemiaes as well as six normal controls. Among thalassemiaes nineteen were Japanese and six Korean. Two kinds of cation exchange columns.; Mono S, HR 5/5 by Pharmacia and TSK gel by Tohso were compared. Hemolysates (10%), in stead of purified globin peptides, were directly subjected to the both columns, and 3H-labeled globin chain in vitro synthesized were separated on them. The Tohso column gave better resolution of globin peptides, resulting in sharp elution profiles. The HPLC system took about two hours for an analysis of a sample. In contrast, the conventional carboxymethyl cellulose (CMC) chromatography by Clegg need larger sample amounts for globin extraction and twenty-four hours to be completed. The HPLC is evidently simple and rapid. The globin chain ratios thus obtained by HPLC were 1.04-1.08, 0.23-0.89, 1.22-1.62 and 2.05-4.29 for normals, thirteen beta-thalassemia minors, seven alpha-thalassemia traits and three Hb H diseases respectively.

Chromatography, High Pressure Liquid↗
PubMed1994

[Antibacterial activity of tosufloxacin against fresh clinical isolates].

The antibacterial activity of tosufloxacin (TFLX) was compared with those of other new quinolones (ofloxacin, ciprofloxacin, sparfloxacin and fleroxacin) against clinical isolates. These isolates had been collected from May to June 1993 (22 species, 260 strains) and from June to July 1992 (Staphylococcus aureus and Pseudomonas aeruginosa, 87 strains) in Toyama municipal hospital. TFLX showed the most potent activities against methicillin-susceptible S. aureus, methicillin-susceptible Staphylococcus epidermidis, methicillin-resistant S. epidermidis, Enterococcus faecalis and Escherichia coli in 1993, at MIC50 levels. The MIC50's of TFLX for these species ranged from 0.025 to 0.39 microgram/ml. TFLX showed potent activities against Klebsiella pneumoniae and P. aeruginosa, and the MIC50's of TFLX were 0.05 and 0.39 microgram/ml, respectively. However, new quinolone resistant strains (MIC > or = 6.25 micrograms/ml) were found among some species. Especially, the number of methicillin-resistant S. aureus (MRSA) strains resistant to new quinolone exceeded 60% of all the S. aureus isolates in 1993. More MRSA strains resistant to new quinolones were isolated in 1993 than in 1992, and similar result was observed for P. aeruginosa. The coagulase typing was done, and all MRSA strains of resistant to new quinolones produced coagulase type II.

Anti-Infective Agents↗
PubMed1993

Fibrin binding, fibrinolytic and fibrinogenolytic activity of plasminogen activator derived from the paranasal mucous membrane of humans.

It is known that large amounts of plasminogen activator (PA) are contained in tissue extracts of the human paranasal mucous membrane (PMM) with chronic sinusitis. The present study was undertaken to isolate and purify the PA in tissue extracts of PMM. Furthermore, the purified PA was identified as to whether it was of the tissue type or urokinase (UK) type, and some of its fibrinolytic characteristics were determined in comparison with those of urokinase. As starting material, extracts of acetone powder of PMM with chronic sinusitis were used, and Zn-imminodiacetate affinity chromatography, and ultrafiltration were carried out to separate and purify the PA from the PMM. The PA was purified to a 107-fold increase in specific activity. The molecular weight of the PA was estimated to be 65,000 to 70,000 d by gel filtration using Sephacryl S-200. The purified PA was stable in the range of pH 8.0 to 9.0. Using S-2288, a synthetic substrate, the Michaelis constant (Km) of the purified PA was estimated to be 0.11 mmol. The binding of the purified PA to fibrin was stronger than that of UK, while the fibrinogenolytic activity of the purified PA was not stronger than that of UK. Based on these results, the purified PA was identified as a tissue-type plasminogen activator (t-PA). From the kinetic data, it was identified as being of the two-chain variety. It is considered that, as a thrombolytic agent, t-PA derived from the PMM could be more useful than UK.

Animals↗
PubMed1993

How great is the incidence of truly congenital common bile duct dilatation?

In an attempt to investigate the causes of common bile duct dilatation (CBDD), activity of the pancreatic enzymes in bile aspirated from the dilated duct during laparotomy was measured in 24 children with CBDD. The reasoning behind this is the fact that the existence of activated pancreatic enzymes, namely raised activity of all enzymes accompanied by trypsin activation, can be regarded as an acquired result of an anomalous choledochopancreaticoductal junction (ACP-DJ). All of the pancreatic enzymes measured were activated in 14 cases (58.3%) but no evidence of activation of enzymes, such as trypsin or others except for amylase and lipase, was observed in the remaining 10 cases (41.7%), whether an ACPDJ was present or absent. Eight of the 10 patients with no enzyme activation (33.3% of the total) were less than 2 months old. The findings in these eight infants, which included cystic dilation or hypoplasia of the intrahepatic duct, provide strong suggestive evidence of the congenital nature of these cases. These results suggest that at least one third of CBDD cases are congenital and the remaining cases are either acquired or a combination of congenital and acquired, or both.

Adolescent↗
PubMed1993

[Study of Legionella pneumophila detection by two step polymerase chain reaction].

We studied the usefulness of two sets of primers in macrophage infectivity potentiator gene sequence of Legionella pneumophila. PCR by 1st step primers produced 649 bp DNA bands and 2nd step primers 489 bp DNA bands. Two step PCR by these primers produced 489 bp DNA bands specific for L. pneumophila. Two step PCR detected 10 fg of pure DNA extracted from L. pneumophila, Philadelphia-1 strain. PCR sensitivity by these primers was superior to former primers reported by us using intratracheal aspirates collected from the patient with L. pneumophila serogroup 2 pneumonia.

Base Sequence↗
PubMed1993

In vitro and in vivo antibacterial activities of T-3761, a new quinolone derivative.

T-3761, a new quinolone derivative, showed broad and potent antibacterial activity. Its MICs for 90% of the strains tested were 0.20 to 100 micrograms/ml against gram-positive bacteria, including members of the genera Staphylococcus, Streptococcus, and Enterococcus; 0.025 to 3.13 micrograms/ml against gram-negative bacteria, including members of the family Enterobacteriaceae and the genus Haemophilus; 0.05 to 50 micrograms/ml against glucose nonfermenters, including members of the genera Pseudomonas, Xanthomonas, Acinetobacter, Alcaligenes, and Moraxella; 0.025 micrograms/ml against Legionella spp.; and 6.25 to 25 micrograms/ml against anaerobes, including Bacteroides fragilis, Clostridium difficile, and Peptostreptococcus spp. The in vitro activity of T-3761 against these clinical isolates was comparable to or 2- to 32-fold greater than those of ofloxacin and norfloxacin and 2- to 16-fold less and 1- to 8-fold greater than those of ciprofloxacin and tosulfoxacin, respectively. When administered orally, T-3761 showed good efficacy in mice against systemic, pulmonary, and urinary tract infections with gram-positive and gram-negative bacteria, including quinolone-resistant Serratia marcescens and Pseudomonas aeruginosa. The in vivo activity of T-3761 was comparable to or greater than those of ofloxacin, ciprofloxacin, norfloxacin, and tosufloxacin against most infection models in mice. The activities of T-3761 were lower than those of tosufloxacin against gram-positive bacterial systemic and pulmonary infections in mice but not against infections with methicillin-resistant Staphylococcus aureus. The activities of T-3761 against systemic quinolone-resistant Serratia marcescens and Pseudomonas aeruginosa infections in mice were 2- to 14-fold greater than those of the reference agents.

Animals↗
PubMed1993

Immunohistochemical studies on small intestinal mucosa in Kawasaki disease.

To investigate the etiology of Kawasaki disease (KD), the cell surface phenotypes of mononuclear cells and enterocytes in the jejunal mucosa of KD were investigated in a case-control study. Sixteen Japanese patients with KD were enrolled in the study. As disease controls, jejunal tissues from 10 patients with diarrhea due to cow's milk protein intolerance were used. The numbers of cells stained by an immunofluorescent technique were counted and analyzed statistically by t test. Both HLA-DR+CD3+ and DR+CD4+ cells were significantly increased in the lamina propria of KD patients in the acute phase compared with numbers in controls and patients with cow's milk protein intolerance (p < or = 0.01). CD8+ cells were significantly reduced in both the epithelium and the lamina propria of KD patients in the acute phase in comparison with numbers in both controls (p < or = 0.05) and patients with cow's milk protein intolerance (p < or = 0.01). HLA-DR+ cells were significantly increased in both the enterocytes and the lamina propria of KD patients in the acute phase compared with numbers in controls (p < or = 0.01). These cell patterns returned to normal in the convalescent phase of KD. Differences between these cell patterns in KD patients with and without diarrhea were not significant, although these immunohistochemical features tended to be more marked in patients with diarrhea than in those who lacked diarrhea. These results are consistent with what one would expect to find if a delayed-type hypersensitivity reaction had occurred in the small intestinal mucosa of KD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1993

Amino acids and peptides. XIX. Preparation of enkephalin-poly(ethylene glycol) hybrid and evaluation of its analgesic activity.

The poly(ethylene glycol) hybrid of Leu-enkephalin (Tyr-Gly-Gly-Phe-Leu) was prepared and its analgesic activity was examined. Poly(ethylene glycol) #4000 was converted to amino-poly(ethylene glycol) and coupled with the N alpha-protected pentapeptide, followed by trifluoroacetic acid treatment to give the hybrid. The hybrid was soluble in water or various organic solvents. The analgesic activity of Leu-enkephalin was markedly potentiated by hybrid formation with poly(ethylene glycol).

Amino Acid Sequence↗
PubMed1993

[Penetration into bone and joint tissues of rabbits and in vitro antibacterial activity of tosufloxacin].

The penetration of tosufloxacin (TFLX) into the bone and joint tissues of rabbits and its in vitro antibacterial activity were compared with those of lomefloxacin (LFLX) which is a efficacious drug for orthopedic infections. Serum levels of TFLX at 1, 2, 4 and 6 hours after oral administration (100 mg/kg) were 0.41, 0.65, 0.62 and 0.42 micrograms/ml, respectively. Except in synovial fluid and femur, TFLX concentrations in bone and joint tissues were higher than those in serum (0.69 approximately 1.92 micrograms/g in bone marrow of sternum, 0.55 approximately 1.53 micrograms/g in bone marrow of femur). TFLX concentrations in synovial fluid at 4 and 6 hours after the administration were equal to those in serum, which were lower than those of LFLX, but the ratio of tissue level/serum level of TFLX was similar to that of LFLX. TFLX was 8- to 64-fold more active than LFLX against Staphylococcus aureus (including methicillin-resistant S. aureus), Streptococcus pyogenes, Haemophilus influenzae, which are major pathogens of purulent osteomyelitis and arthritis. TFLX inhibited the growth of these bacteria at less than 0.39 micrograms/ml. These results indicate that TFLX is a useful drug for orthopedic infection.

Administration, Oral↗
PubMed1992

Pseudohyperkalaemia in Kawasaki disease.

Pseudohyperkalaemia was observed in 3 of 16 patients with Kawasaki disease showing remarkably increased platelet counts. Their plasma potassium concentration, which is not affected by in vitro coagulation, was in the normal range despite the increased serum level. A significant correlation was observed between the platelet count and the increase in the serum potassium level resulting from blood coagulation, which was estimated by subtracting the plasma potassium level from the serum level. This study indicates that pseudohyperkalaemia should be considered in patients with Kawasaki disease whose platelet counts are markedly increased.

Child, Preschool↗