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Biomedical subjects

H Kawada

Publications and source records attributed to H Kawada.

At least 19 recordsLinked to original sources

Clinical significance of LEA-1 expression in adult acute myeloid leukemia.

In this study, we examined expressions of several adhesion molecules (AdMs), i.e. leukocyte function antigen-1 (LFA-1: CD11a/CD18), Hermes homing receptor (CD44) and intercellular adhesion molecule-1 (ICAM-1: CD54), on leukemia cells from 51 adult patients with newly diagnosed acute myeloid leukemias (AMLs) to elucidate clinical significance of these AdM expressions. Those expressions in lymphoid malignancies have been correlated with tumor evolutions, but CD44 was detected in all the AML cases examined and CD54 expression did not associate with their clinical characteristics or outcomes. However, we found that LFA-1 expressions significantly correlated with splenomegaly, resistance to induction chemotherapies and short survival periods in AML patients.

Acute Disease

In-vitro and in-vivo antibacterial activity of plaunotol, a cytoprotective antiulcer agent, against Helicobacter pylori.

Recently, some antiulcer agents have been reported to have antibacterial activity against Helicobacter pylori, which is highly associated with gastritis and peptic ulcers. In-vitro and in-vivo activity of plaunotol, a cytoprotective antiulcer agent, against H. pylori was investigated. Antibacterial activity of plaunotol against a standard strain (NCTC 11637) and 14 clinical isolates was compared with those of other cytoprotective antiulcer agents: benexate, sofalcone, teprenone, cetraxate, and gefarnate, by an agar dilution method. The MIC50 and MIC90 of plaunotol against 15 strains were 6.25 and 12.5 mg/L, respectively, making it the most potent of the cytoprotective antiulcer agents. The bactericidal effect of plaunotol was investigated using an in-vitro killing assay. Plaunotol at concentrations of more than 6 mg/L induced a rapid reduction of culture turbidity, with an extensive loss of viability, within 30 min. Observation by scanning electron microscopy revealed that plaunotol caused autolysis and treated cells were deformed. In-vivo activity of plaunotol against H. pylori was examined in a nude mouse gastritis model. Plaunotol significantly decreased the number of H. pylori in the stomach of nude mice. In addition, the antiulcer agent enhanced the antibacterial activity of amoxycillin or clarithromycin in the infection model.

Amoxicillin

Bactericidal effect of plaunotol, a cytoprotective antiulcer agent, against Helicobacter pylori.

In order to investigate the bactericidal effect of plaunotol, an oily antiulcer agent, against Helicobacter pylori, comparative studies were conducted using its derivatives, M-4, M-5, and M-6, whose hydrophobicity decreased in the order of plaunotol > M-6 > M-5 > M-4 by log P determination. Plaunotol rapidly reduced the viability of H. pylori in vitro, and cell death was associated with cell lysis. In addition, plaunotol showed eightfold stronger bactericidal activity against H. pylori than M-6 and M-5, while the compound with the lowest hydrophobicity, M-4, showed no bactericidal activity. The bactericidal activities of plaunotol and its derivatives were related to the hydrophobicity of these compounds. To investigate a possible interaction between these compounds and the cell membrane of H. pylori, their effects on liposomal membranes prepared from phosphatidylethanolamine and cardiolipin, which are known to be present in the membrane of H. pylori, were determined by detection of glucose release from the liposomes. Plaunotol showed eight-fold higher activity than M-6 and M-5, while M-4 showed no activity. The effects of plaunotol and its derivatives on liposomal membrane were therefore related to their bactericidal activities. In addition, it was confirmed that the bactericidal effect of plaunotol against H. pylori was neutralized by the liposomal membrane, and that plaunotol led to an increase in permeability of the membrane, as evidenced by measurement of the leakage of 260 nm absorbing-material from H. pylori. These results suggest that the bactericidal effect of plaunotol against H. pylori is due to the interaction between this compound and the bacterial cell membrane.

Anti-Bacterial Agents

Insecticidal effects of the insect growth regulators methoprene and pyriproxyfen on the cat flea (Siphonaptera:Pulicidae).

Residual effectiveness of the insect growth regulators pyriproxyfen and methoprene against cat flea, Ctenocephalides felis (Bouché), larvae were evaluated under simulated household conditions. Pyriproxyfen provided control of larvae for > 12 mo when applied at 1 mg and 0.2 mg/m2 and > or = 3 mo at the rate of 0.04 mg/m2. Methoprene applied at 1 mg/m2 provided control for > 12 mo and 6 mo at 0.2 mg/m2. No significant mortality was observed when methoprene was applied at 0.04 mg/m2.

Animals

The usefulness of ultrasonic microprobe imaging for endoscopic variceal ligation.

OBJECTIVES: This study investigated whether ultrasonic microprobe (UMP) imaging was useful in judging the therapeutic effect of endoscopic variceal (EVL) on varices as well as assessing varices and surrounding vessels before and after EVL. METHODS: UMP imaging was performed repeatedly safely and easily via the biopsy channel of an endoscope in 20 patients with esophageal varices. Using this modality in combination with our method of "intensive ligation," we treated esophageal varices successfully. RESULTS: Before EVL, UMP imaging displayed esophageal varices, periesophageal collaterals, and the azygous vein as echo-free lumens. In 15 of 20 patients, UMP imaging clearly detected the perforating vein, one of the optimal ligation sites for EVL, connecting the varix and collateral vein. Just after EVL, UMP imaging revealed a hyperechoic change ("snow ball" sign or "snow channel" sign), indicating blood flow stasis in the esophageal varices. On subsequent EVL, UMP imaging showed the cross-sectional area of varices was undetectable (occluded) or partially detectaable. After repeated EVL (2.9 treatment sessions on average), UMP imaging, as well as endoscopy, indicated that almost all varices were eradicated (undetectable). However, UMP imaging demonstrated that neither collaterals nor the azygous vein had significantly changed in size. CONCLUSIONS: This modern diagnostic modality provided a clinical adjunct to current endoscopy when observing esophageal varices and surrounding vessels before and after EVL to determine the need for additional therapy.

Aged

[Outbreaks of pulmonary tuberculosis in a family and in a hospital. Analysis of restriction-fragment-length polymorphisms].

Restriction-fragment-length polymorphism, analysis was used to study two outbreaks of pulmonary tuberculosis, one in a family and one in a hospital. The DNA probe was derived from the insertion sequence IS 6110. Two groups of isolates were analyzed, both of which were suspected to be common sources of each infection. Both groups showed identical fingerprints within each group. These results suggest that analysis of restriction-fragment-length polymorphism is useful in epidemiological studies of pulmonary tuberculosis.

Adult

[The usefulness of induced sputum in the diagnosis of pulmonary tuberculosis].

This study was designed to compare the results of culture for tubercle bacilli using induced sputum by an ultrasonic nebulizer and gastric aspirates from same patients who were suspected of having active tuberculosis with little or no sputum and had received no prior chemotherapy. 22 patients included in this series were either culture positive for tubercle bacilli or showed unequivocal radiographic improvement after three months of therapy with three anti-tuberculosis drugs. Induced sputum from 17 patients and gastric aspirates from seven patients were culture positive for M.tuberculosis. This difference is significant (p < 0.01). Paired induced sputum and gastric aspirates were both positive for tubercle bacilli in seven patients. The finding of acid-fast bacilli on microscopy or tubercle bacilli in culture in four of the seven patients were available much earlier with induced sputum than with gastric aspirates. Positive gastric aspirates and negative induced sputum for tubercle bacilli was not seen. These results suggest that induced sputum by an ultrasonic nebulizer is superior to gastric aspirates in terms of high sensitivity and early finding for tubercle bacilli and induced sputum and gastric aspirates do not supplement each other.

Adolescent

Simple 13C-urea breath test with infra-red spectrophotometer.

When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy.

Breath Tests

A case of right atrial myxoma--effect of large myxoma in the right atrium studied by M-mode and Doppler echocardiography.

Doppler profiles are rarely used to assess cardiac function that has been partially impaired by a sizeable myxoma in the right atrium or to evaluate the improvement caused by extirpation of the tumor. In a 54-year-old man with a large right atrial myxoma (6.5 x 5.5 x 4.0 cm) along with first-degree atrioventricular (AV) block, M-mode and pulsed Doppler echocardiography were used to evaluate the left ventricular systolic and diastolic function before and 1 month after surgical removal of the myxoma. End-diastolic left ventricular (LV) and left atrial diameters increased postsurgically from 47 to 51 mm and from 38 to 41 mm, respectively, while end-systolic LV remained unchanged. In the LV inflow pattern, peak early filling velocity (E) increased substantially (preoperative 31, postoperative 58 cm/sec), with no change in peak late filling velocity (A) (53 cm/sec), which gave a favorable E/A ratio (from 0.58 to 1.09). First-degree AV block resolved after tumor resection (PR interval: 0.23 vs 0.20 sec). Improved LV diastolic function associated with natural recovery from the myxoma was ascribed to the restoration of preload and recovery of systolic function. The results of this study show that removal of a large myxoma in the right atrium is important not only for preventing possible obstruction of the tricuspid orifice, eliminating pulmonary emboli, and maintaining systolic function, but also for restoring LV diastolic function.

Diastole

Biological and physicochemical properties of fenitrothion microcapsules as a residual spraying formulation for mosquito control.

Insecticidal properties of fenitrothion microcapsules (MC3) as a new residual spraying formulation for mosquito control were studied. Adult female Anopheles albimanus were confined so as to contact several surfaces treated with fenitrothion MC or wettable powder (WP) for 10 and 30 min. Residual efficacy of MC at the rate of 1 g/m2 was almost equivalent to that of WP at the rate of 2 g/m2 on a plywood surface and was superior to that on an unglazed pottery surface. Greater than 50% mortality was maintained for more than 28 wk after treatment by fenitrothion MC on a mud surface with 10 min of contact at the rate of 2 g/m2. The effective duration on a mud surface treated with WP was less than 44 wk with 30 min of contact and was less than 12 wk with 10 min of contact at the rate of 2 g/m2. Microcapsule particles were observed to be mechanically broken (trampled) by mosquito contact, and the amount of fenitrothion released from MC increased as contact time increased. Comparison of MC with WP and emulsifiable concentrate formulations in this study indicates that the increased residual activity results from protection from evaporation and decomposition afforded by capsule walls of the MC formulation.

Animals

Flow cytometric analysis of cell-surface antigen expressions on acute myeloid leukemia cell populations according to their cell-size.

Acute myeloid leukemia (AML) cells which expanded from a single leukemic cell show certain degrees of morphological and biological heterogeneity. In the present study, we determined cell-surface antigen expressions (CD13, 33, 34 and 38, and HLA-DR) on AML cells based on their cell-size (large vs small cells) by flow cytometry. We found that the cell-surface antigens were more strongly expressed on the large leukemic cells than the small cells, regardless of FAB subtypes. Furthermore, our preliminary study demonstrated that AML patients who showed a relatively small difference in antigen expression between large and small leukemic cells had longer remission durations and survival periods, compared with those with a more prominent difference in antigen expression. Thus, the heterogeneity of AML cells determined by the combination of cell-surface antigen expressions and cell-size may be associated with clinically important biological behaviors.

Adult

Post-natal decrease in chronotropic sensitivity to acetylcholine in rat heart.

1. The negative chronotropic effects of acetylcholine and carbachol on isolated rat right atria were examined at 0, 4, 8, and 16 weeks after birth. 2. Acetylcholine produced negative chronotropic responses at all ages and completely abolished spontaneous beating at its maximum effective concentration. 3. The sensitivity to acetylcholine, expressed in terms of ED50 values, was higher at 0 and 4 weeks than at 8 and 16 weeks, ED50 values (microM) at 0, 4, 8 and 16 weeks being 9.5 +/- 1.8 (n = 12), 13.2 +/- 3.4 (n = 11), 59.3 +/- 10.9 (n = 14) and 51.5 +/- 17.5 (n = 5), respectively. 4. Neostigmine produced a leftward shift of the concentration-response curve for acetylcholine both at 4 and 8 weeks after birth. The shift was larger at 8 weeks and no difference in sensitivity to acetylcholine was observed between the two ages in the presence of neostigmine. 5. Further, no developmental changes were observed in the sensitivity to carbachol, which is not hydrolyzed by cholinesterase. 6. We concluded that the chronotropic sensitivity to acetylcholine of rat atria decreases post-natally during the period between 4 and 8 weeks after birth due to increase in cholinesterase activity.

Acetylcholine

[Clinical studies of a newly developed miconazole preparation for intravenous drip infusion (MJR-1761) in hematologic disease patients with deep-seated fungal infections].

The efficacy and safety of a newly developed miconazole preparation (MJR-1761) for intravenous drip infusion were evaluated in 22 patients with hematological diseases complicated by documented or suspected deep-seated fungal infections. They consisted of 15 patients with fungemia, 2 patients with pulmonary mycosis, and 5 patients with mycosis of the digestive tract. Of the 5 patients, 3 had a complication of fungemia and 1 a complication of urinary tract mycosis. Of the 22 patients, 21 were clinically evaluable. All the patients were included in safety evaluation. The effective rate was 86% (18/21) when moderately improved or better evaluations were included, and the usefulness rate was 81% (17/21) when moderately or more useful evaluations were taken into consideration. Side effects occurred in 4 patients, and abnormal laboratory values were obtained in 4 patients. All these changes, which were previously reported, improved after the discontinuation of the treatment. The results presented indicate that the miconazole intravenous drip infusion solution used in this study is as effective as conventional similar preparations. Since the infusion solution need not be diluted immediately before use, it is simple to use, and its safety may be highly rated. The purpose can be met with less volume of solution per use than before because the preparation contains as much as 200 mg of miconazole in 75 ml of solution. This preparation seems to lend itself better to clinical application than conventional similar infusion solutions.

Adult

Upregulation of cell surface expression of T-lymphoid antigens and adhesion molecules on acute myeloid leukaemia cells after in vivo administration of granulocyte colony-stimulating factor.

We herein report a case of acute myeloid leukaemia (AML, FAB:M0) who showed upregulation of T-lymphoid antigens (CD2, CD7) and adhesion molecules (CD11a, CD11b, CD18) on leukaemic cells after in vivo administration of granulocyte colony-stimulating factor (G-CSF). To our knowledge, this is the first report which describes in vivo changes of cell surface antigen expression on AML cells after the administration of G-CSF.

Aclarubicin

[Effects of cytarabine ocfosfate on colony-stimulating factor in myelodysplastic syndrome with monosomy 7].

A 42-year-old man was admitted to our hospital because of pancytopenia in April 1992. A diagnosis of refractory anemia was made. The karyotype was normal male type on the initial study. Subcutaneous administration of granulocyte colony-stimulating factor (G-CSF) initially increased the peripheral neutrophil count, bat in January 1993, although blast cells did not increase, neutrophils had decreased in spite of the continuation of G-CSF administration. Chromosome analysis showed 46XY, +Y, -7 at this point. By adding 50 mg of cytarabine ocfosfate (SPAC) daily, the peripheral neutrophil count again rose dramatically. However, anemia, thrombocytopenia and the chromosomal abnormality were unchanged. These results indicate that SPAC may upregulate the effect of G-CSF on granulopoiesis in patients with myelodysplastic syndrome.

Adult