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Biomedical subjects

K Horikawa

Publications and source records attributed to K Horikawa.

At least 55 records · Page 3Linked to original sources
PubMed1997

[A study for serodiagnosis of verotoxin-producing Escherichia coli (enterohemorrhagic E. coli) O157 by the bacterial agglutination technique].

We evaluated the usefulness of bacterial agglutination antibodies for serodiagnosis of verotoxin-producing Escherichia coli (enterohemorrhagic E. coli) O157 infections. We examined 50 serum samples from 50 control children (whiout diarrhea 31, with diarrhea 19), 24 samples from 8 diarrhea cases due to O157:H7, 37 samples from 14 cases of hemolytic uremic syndrome (HUS) for antibodies to heat-killed E. coli E32511 (O157:H.-) strain using the bacterial agglutination technique. Of the control sera all but one (x80) showed 20 > or = in the antibody. All the diarrhea patients due to O157:H7 showed a significant rise (x160-x5120) of the titers in the sera at 5-7 days on illness, after that the titers fell rapidly. Significant antibody rise (x160-x5120) was detected in twelve out of 14 HUS patients at the early stage of the illness which fell in the convalescent phase. The assay appeared to be a useful serodiagnostic technique because of its easiness and simplicity as well as because of its high sensitivity and specificity.

Agglutination Tests↗
PubMed1997

[Transarterial platinum coil embolization for direct carotid-cavernous fistula].

Two cases of direct carotid-cavernous fistula (CCF) were treated by transarterial platinum coil embolization (TACE) following unsuccessful transarterial balloon embolization (TABE). Case 1 was a 47-year-old man who complained of pulsatile left exophthalmos, chemosis and bruit. Left carotid angiograms showed a CCF with anterior, posterior and cortical venous drainage. Near total obliteration of the CCF was achieved by TABE, but it showed recurrence in the next morning. At this time, left carotid angiograms showed a CCF which drained only into the cortical veins via the enlarged sphenoparietal sinus. Because of high risk of intracranial hemorrhage, TACE was performed immediately. The result was successful. Case 2 was an 82-year-old woman who suffered from traumatic subarachnoid hemorrhage. First right carotid angiograms showed a small CCF which drained only into the inferior petrosal sinus. Right exophthalmos, swelling of the eyelids, severe eye pain and bruit appeared gradually. The second right CAG performed three months after the head trauma showed markedly dilated superior ophthalmic vein which was the new main draining root of the CCF. Because of progressive symptoms, TACE was performed immediately after the angiography, which proved successful. Direct CCFs must be treated aggressively because they don't cure by spontaneous obstruction of fistula. Although TABE is the first choice for direct CCF, complete occlusion of CCF in difficult in some cases. Those cases have; 1) small fistula of CCF for balloon insertion, 2) large fistula for occlusion by balloons, 3) not enough space for inserting a balloon after recurrence of CCF, and 4) sharp objects (bone fracture fragments, foreign objects) may puncture the balloon. If TABE couldn't provide successful treatments, TACE should be considered as an alternative treatment for direct CCF after angiography without delay because it is less complex compared with TABE.

Aged↗
PubMed1997

[Echocardiographic evaluation of cardiotoxicity induced by anthracycline therapy].

Echocardiographic reports on 144 adults receiving anthracycline therapy and 18 controls were reviewed for the possible relationship between dosage and ejection fractions. The cardiotoxicity of each anthracycline drug was evaluated as follows: Pirarubicin = 0.8, Mitoxantrone = 3.4, Daunorubicin = 0.5, Aclarubicin = 0, and Epirubicin = 0.6 with Doxorubicin = 1 as a control. As a whole, the ejection fractions, which decreased subsequently compared with increasing amount of dosage, showed a remarkable decrease at the dosage level of 600 mg/m2. However, the ejection fractions differed among individual patients. It was predicted that heart failure would not develop when the ejection fractions exceeded 55%. It is desirable to stop anthracycline therapy when the ejection fractions drop to 55%.

Aclarubicin↗
PubMed1997

[Investigation of doxorubicin cardiotoxicity by echocardiogram and the appropriate method of using doxorubicin].

For a sample of 136 adults on whom Doxorubicin (DXR) had been used, we looked for the ejection fraction (EF) by echocardiography and examined its relationship with the amount of DXR. Our results showed that as the amount of DXR increased the EF decreased significantly, particularly with aging. The use of previous mediastinal radiation and 5-FU, etc. on breast cancer patients had no effect on the EF. From our examination of patients developing congestive heart failure, we repeatedly performed echocardiography and found that DXR can be safely used until the EF decreases to 55 percent. In this way, we can find many patients with whom it is possible to use DXR in larger amounts than 550 mg/m2. In general, large quantities of DXR can be used on young people, but for elderly people, large quantities of DXR should be used with caution.

Adult↗
PubMed1996

Preferential hematopoiesis by paroxysmal nocturnal hemoglobinuria clone engrafted in SCID mice.

In paroxysmal nocturnal hemoglobinuria (PNH), little is known about the molecular events leading to the clinical manifestations except for the hemolysis. To unfold the complex pathophysiology, it is necessary to elucidate the nature of the PNH clone. PNH exhibits an acquired stem cell disorder, a clonal expansion of affected cells, concomitant depression of normal hematopoiesis in bone marrow (BM), and, although infrequently, the development of leukemia. The PNH clone is thus expected to exhibit some neoplastic features. We report here that CD34+ hematopoietic progenitor cells of PNH-BM yielded blood cells of three lineages with PNH phenotype alone when transplanted into sublethally irradiated severe combined immunedeficient mice. The hematopoiesis persisted for more than 10 months and did not always need human cytokines. In contrast, the hematopoiesis by control grafts obtained from healthy volunteers required an intense cytokine treatment. This in vivo model defines the preferential hematopoiesis of pluripotent PNH progenitor cells, indicating the intrinsic growth abnormality of PNH clone.

Adult↗
PubMed1995

Markedly high population of affected reticulocytes negative for decay-accelerating factor and CD59 in paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) blood cells lack glycosylphosphatidylinositol-anchored membrane proteins such as decay-accelerating factor (DAF) and CD59. This lack is of diagnostic value in PNH. Because reticulocytes in PNH are not yet well characterized, we analyzed reticulocytes obtained from 12 patients with PNH and from 5 healthy volunteers by two-color flow cytometry with a membrane-permeable fluorescent dye, thiazole orange, to identify reticulocytes and monoclonal antibodies to DAF and CD59. Healthy individuals had no affected cells. In all patients, the population of affected reticulocytes negative for DAF and CD59 was markedly higher than the population of affected erythrocytes. Moreover, the population of affected erythrocytes became obviously low in patients who received transfusions and suffered from hemolytic precipitation, whereas the population of affected reticulocytes was unchanged. The persistently high population of affected reticulocytes, despite cytolytic exclusion and an inherently short lifetime, might possibly be explained by relative reticulocytosis caused by an anemia-induced feedback stimulation of erythropoiesis in PNH. Thus, affected reticulocytes could be a reliable marker for the diagnosis of PNH and for the evaluation of erythropoiesis by PNH stem cell.

Adolescent↗
PubMed1995

Paroxysmal nocturnal hemoglobinuria clone in bone marrow of patients with pancytopenia.

The lack of glycosylphosphatidylinositol (GPI)-anchored membrane proteins such as decay-accelerating factor (DAF) and CD59 on blood cells has a diagnostic value in paroxysmal nocturnal hemoglobinuria (PNH). Because PNH often develops in patients with aplastic anemia (AA), we attempted to detect a PNH clone in the bone marrow (BM) of patients with AA and pancytopenia before affected cells were evident in the peripheral blood (PB). We used flow cytometry with monoclonal antibodies against DAF and CD59 for the detection of the clone. Affected cells were observed in the BM of 3 of 7 patients with AA and 1 of 3 patients with pancytopenia of unknown origin, but not in their PB. All 8 patients with apparent PNH had affected cells in their BM and PB. On the basis of the early appearance of the PNH clone in the BM, a prospective 4-month follow-up study of the PB cells was performed. The study showed the release of affected mature cells first in granulocytes, then in monocytes, and finally in lymphocytes. Ham's test was positive before affected erythrocytes were detected by flow cytometry. Our findings indicate that detection of the PNH clone in BM could be predictive of the development of PNH in patients with AA and pancytopenia.

Anemia, Aplastic↗
PubMed1995

Astrocytoma linked to familial ataxia-telangiectasia.

A 7-year and 11 month-old girl with cerebellar astrocytoma linked to familial ataxia-telangiectasia (AT) is presented. She was born as the 7th girl of a woman with aortic arch syndrome. Two elder sisters of the patient have ataxia telangiectasia. She had immunodeficiency, and cerebellar ataxia, but had no oculocutaneous telangiectasia. The risk of cancer developing in AT patients is about 1,200 times greater than that in age-matched controls. With regard to central nervous system tumours, seven primary tumours have been reported, such as 3 cases of medulloblastoma and 4 cases of glioma. Members of AT families who were under the age of 45 had a risk of dying of a malignant neoplasm five times greater than in the general population. However, there were no reports of glioma in AT families. In this case, it is suggested that IgA deficiency linked to familial AT may have contributed to the development of astrocytoma.

Astrocytoma↗
PubMed1995

Effects of long-term treatment with low-dose pravastatin on biliary lipid and bile acid composition in patients with nonfamilial hyperlipoproteinemia.

We tested the possibility that pravastatin, a competitive inhibitor of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase, would alter cholesterol saturation of gallbladder bile by decreasing its cholesterol saturation index and/or degree of fatty acyl chain unsaturation in lecithin. Eighteen patients with type IIa hyperlipoproteinemia were treated with pravastatin 10 mg/d for 12 months. Gallbladder bile samples were aspirated with a duodenal tube by stimulating gallbladder contraction with intramuscular administration of cerulein before and after treatment. Serum cholesterol level was significantly reduced by 20% after 3 months, and this level was maintained after 12 months. In contrast, the cholesterol saturation index of gallbladder bile was not altered after 3 months (1.52 +/- 0.20 v 1.70 +/- 0.24), but it decreased significantly after 12 months (0.95 +/- 0.11, P < .01). The degree of fatty acyl chain unsaturation tended to decrease, although this was not statistically significant except for the decrease in molar percent of linoleate after 3 months. These findings suggest that long-term treatment with an inhibitor of HMG CoA reductase improves bile lithogenicity even at a comparatively low dose, and can decrease the incidence and complications of cholesterol gallstones.

Adult↗
PubMed1995

The induction of micronuclei in mice hepatocytes and reticulocytes by tetrachloroethylene.

The clastogenicity of tetrachloroethylene (tetra) was detected by means of the micronucleus assay using hepatocytes and reticulocytes from ddY male mice, to understand its effects in upon hepatocellular carcinomas in mice. The frequency of micronucleated hepatocytes of mice that received a single injection of tetra after partial hepatectomy increased to levels that were significantly higher than those of controls treated with solvent. However, the micronucleus assay using peripheral blood reticulocytes from ddY male mice, revealed that tetra did not induce to a statistically significant increase in micronucleus frequency. These results suggested that tetra metabolites have a clastogenic effect in vivo upon mouse liver but not upon bone marrow cells.

Animals↗
PubMed1995

Alteration in the reactivity of sphingomyelin in mitogen-stimulated lymphocytes.

The antigens for a monoclonal antibody, VJ-41, established by alloimmunization of B10.A(3R) mice with lymphocytes from B10.A(5R) mice and screening of its reactivity toward Con A-stimulated human T lymphocytes, were found to be phosphorylcholine-containing ceramides (sphingomyelin) and disaturated fatty acyl glycerol (phosphatidyl-choline, PC), but neither deacylated sphingomyelin nor unsaturated fatty acid-containing PC reacted with the antibody. Although the reactivity of disaturated fatty acyl PC increased with increasing chain length, that of sphingomyelin was stronger than that of di-20:0-PC. The binding of the antibody to Con A-stimulated lymphocytes was inhibited by sphingomyelin-containing liposomes, but not by di-18:0-PC-containing ones, and the concentration of sphingomyelin in Con A-stimulated human T-lymphocytes was the same as that in non-stimulated ones, indicating that the reactivity of sphingomyelin in lymphocytes is altered by Con A-stimulation.

Animals↗
PubMed1995

[Prevalence of pertussis in Fukuoka: incidence and MICs of antibiotics for Bordetella pertussis isolate].

For bacteriological examinations of whooping cough patients, nasopharyngeal specimens were directly inoculated on the cyclodextrin solid medium (CSM) supplemented with 5 micrograms of cephalexin (CEX) per ml. The inoculated plates were cultured in an incubator at 35 degrees C for 3 to 7 days. During the period from 1990 to 1993, B. pertussis (43 strains) and B. parapertussis (1 strain) were isolated from 145 whooping cough patients and 34 relatives. B. pertussis were isolated sufficiently in June to December during the year. It was suggested that during this period epidemics of whooping cough occurred. All isolates of B. pertussis had K antigen consisting of 1, 3, and 6. The determination of minimal inhibitory concentrations (MIC) of antibiotics to B. pertussis was carried out by the micro dilution technique modified from the standard methods. The Stainer-Scholte broth, supplemented with heptakis (2,6-O-dimethyl) beta-cyclodextrin, was used for dilution of the drug, and also for cultivation of bacteria. For determining susceptibility of bacteria to antibiotics, twenty seven isolates of B. pertussis and one of B. parapertussis were precultured on CSM at 35 degrees C for 2 days. The turbidity of broth cultures was adjusted to that of McFarland no. 0.5, and diluted to the concentration of 10(6) CFU/ml. One hundred microliters of these suspensions were added to 25 microliters of each antibiotic solution. After incubation for 3 days at 35 degrees C, the turbidity of the bacteria was read macroscopically for determining the MICs. On the other hand, we compared the agar dilution MICs of 23 antibiotics to the broth microdilution MICs for 27 B. pertussis isolates.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1995

Expression of cryptantigen Th on paroxysmal nocturnal hemoglobinuria erythrocytes in association with a hemolytic exacerbation.

Paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes lack complement regulatory membrane proteins and are susceptible to complement. Although the critical role of complement in intravascular hemolysis in PNH is accepted, the precise mechanism of complement activation in vivo is unknown. Accordingly, in a PNH patient who was suffering from a hemolytic precipitation soon after a common cold-like upper respiratory infection, we analyzed the erythrocytes with lectins and by flow cytometry to detect membrane alteration that lead to complement activation. The lectin reactivity of erythrocytes showed the expression of cryptantigen Th. The patient serum at the time of the hemolysis induced the expression of Th on erythrocytes from PNH patients and from healthy volunteers in vitro, whereas neither the patient serum after recovery from the hemolysis nor blood type-matched control serum from healthy donor showed this activity. Moreover, autologous serum selectively hemolyzed Th+ PNH erythrocytes, but not Th- PNH erythrocytes, or Th+ control erythrocytes. Hemolysis was not observed either in complement-inactivated serum or in blood type-matched cord blood serum, which lacks natural antibodies to cryptantigens. These findings indicate that the immunoreaction of infection-induced Th with natural antibody on PNH erythrocytes is a trigger of the complement activation, leading to intravascular hemolysis.

Adolescent↗