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Biomedical subjects

T Higuchi

Publications and source records attributed to T Higuchi.

At least 307 records · Page 17Linked to original sources
PubMed1997

Increased production of interleukin-1beta and interleukin-1 receptor antagonist by peripheral blood mononuclear cells in undialyzed chronic renal failure.

We investigated the cell content and production of IL-1beta and IL-1 receptor antagonist (Ra) by unstimulated and lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) obtained from 15 undialyzed patients with chronic renal failure (CRF; estimated GFR <10 ml/min), 15 patients on chronic hemodialysis (HD) and 15 healthy controls. These cytokines were measured by ELISA. The cell content of IL-1beta in freshly obtained PBMC was not detectable in any group. In contrast, that of IL-1Ra in CRF (1,807 +/- 370 pg/ml, p < 0.05) as well as in HD (1,791 +/- 151 pg/ml, p < 0.001) was significantly higher than that of the controls (907 +/- 156 pg/ml). In unstimulated cultured PBMC, spontaneous production of IL-1beta in CRF (66 +/- 13 pg/ml, p < 0.05) and in HD (81 +/- 29 pg/ml, p < 0.05) was significantly higher than that of the controls (26 +/- 3 pg/ml). In contrast, comparison of spontaneous production of IL-1Ra in the three groups was not significantly different. In LPS-stimulated PBMC, IL-1beta production in CRF (10,896 +/- 1,359 pg/ml, p < 0.01)and in HD(11,441 +/- 1,400 pg/ml, p < 0.01) was significantly higher than that of the controls (6,117 +/- 572 pg/ml). However, IL-1Ra production by LPS-stimulated PBMC in the three groups was not significantly different. Moreover, the spontaneous IL-1Ra/IL-1beta production ratio in CRF (140 +/- 16, p < 0.01) and in HD (142 +/- 19, p < 0.01) was significantly lower than that of the controls (294 +/- 41). The present study demonstrates that cytokine production by PBMC in undialyzed CRF patients as well as in hemodialyzed patients is heightened and may induce impaired function of the immunological system before CRF patients are introduced to dialysis.

Adult↗
PubMed1997

Recent advances in evolvable systems--ICES 96 (International Conference on Evolvable Systems).

This paper reviews the developments in evolvable hardware systems presented at the First International Conference on Evolvable Systems (ICES 96). The main body of the review gives an overview of the 34 papers presented orally, splitting them into three broad groups according to whether they involve (1) evolving a fit solution to a problem as a member of a population of competing candidates, (2) evolving solutions that can individually learn from and adapt to their environments, or (3) the embryonic growth of solutions. We also review the discussion sessions of the conference and give pointers to related upcoming events.

Algorithms↗
PubMed1997

Isolation of Streptococcus equi subsp. equi from thoroughbred horses in a racehorse-breeding area of Japan.

For determination whether strangles has invaded the Hidaka district of Hokkaido, the main racehorse-breeding area of Japan, a epizootiological survey with bacterial isolation was carried out during the breeding season in 1995. Streptococcus equi subsp. equi, which is the causative agent of strangles, was isolated from two Thoroughbred horses with submandibular lymphadenitis. Isolates were identified by serological grouping, biochemical tests and analysis of cell surface proteins by Western immunoblotting. Through this survey, it revealed that S. equi subsp. equi has invaded the Hidaka district and that strangles has become prevalent in racehorse-breeding farms in this area.

Animals↗
PubMed1997

Inhibitory effect on LPS-induced tumor necrosis factor in calves treated with chlorpromazine or pentoxifylline.

The inhibitory effect of chlorpromazine (CPZ), pentoxifylline (PTX) and dexamethasone (DEX) was investigated in a model of endotoxin shock in Holstein calves following an intravenous administration of Esherichia coli endotoxin (LPS). Initial correlations with its effects on the levels of tumor necrosis factor (TNF), a pivotal mediator of endotoxin shock, and clinical signs were obtained. The pretreatment of CPZ or DEX significantly decreased the serum levels of TNF, and reduced endotoxic shock. But the pretreatment of PTX hardly reduced the increase of serum TNF levels and endotoxin shock. The levels of serum endotoxin were not significantly different a minute of postinjection of LPS in calves. The results of this study indicate that pretreatment of CPZ or DEX inhibit various biological effects on endotoxin in calves.

Animals↗
PubMed1997

Isolation of virulent Rhodococcus equi from transtracheal aspirates of foals serodiagnosed by enzyme-linked immunosorbent assay.

Although isolation of Rhodococcus equi from tracheobronchial aspirates is thought to be a definitive diagnosis of R. equi pneumonia in foals, virulence of isolates from the aspirates of infected foals remains obscure. In the present study, transtracheal aspirates were collected from thirty-one 1- to 6-month-old foals, which showed clinical signs of respiratory tract infection, and R. equi isolates were analyzed for the presence of virulence plasmids and virulence-associated antigens. Moreover, this method was compared with a serodiagnosis by an enzyme-linked immunosorbent assay (ELISA) to evaluate the sensitivity of the ELISA. Of the 31 foals, 21 revealed positive cultures for R. equi. Of the 21 foals, 20 (95%) had an ELISA OD value of 0.3 (positive limit of this test) or higher at the initial medical examination. All of the isolates from the aspirates were virulent R. equi, which contained virulence plasmids and expressed virulence-associated antigens. In the remaining 10 foals showing a negative culture for R. equi, 3 foals had positive ELISA titers. Six foals died during the treatment, and necropsy revealed that 5 of the 6 foals had R. equi infection characterized by large abscesses in the lungs, and 3 of the 5 foals also had intestinal lesions. All clinical isolates from the lesions of the foals were virulent R. equi. These results support the assumption that isolates from the transtracheal aspirates of infected foals are virulent R. equi and the sensitivity of ELISA might demonstrate a serodiagnostic value for early diagnosis of R. equi infection in foals.

Actinomycetales Infections↗
PubMed1997

Preoperative detection of the composition of atherosclerotic plaque in the carotid artery using ultrasonography and magnetic resonance imaging.

Preoperative identification of the components of atherosclerotic plaque was attempted using ultrasonography in five patients and magnetic resonance (MR) imaging in three patients before carotid endarterectomy. The correlation between surgical and histological findings, and preoperative ultrasonography and MR imaging was evaluated. Plaque consisting predominantly of calcification appeared as bright echo on ultrasonography and was tough. Plaque consisting predominantly of hemorrhage was echolucent, appeared as low intensity on T2-weighted MR images and was fragile. Such preoperative assessment of plaque composition using ultrasonography and MR imaging is useful for manipulation of atherosclerotic plaque during carotid endarterectomy.

Aged↗
PubMed1997

Inhibitory effect of drugs with a ketone group on reduction of acetohexamide catalyzed by carbonyl reductase from rabbit kidney.

The reduction of acetohexamide catalyzed by carbonyl reductase from rabbit kidney was inhibited by befunolol, moperone, levobunolol, daunorubicin and loxoprofen, which have a ketone group within their chemical structures and are substrates for the enzyme. A significant correlation was observed between the common logarithm of Vmax/Km values of the enzyme for befunolol, moperone, levobunolol and daunorubicin and the percentage inhibition of the enzyme, confirming that these drugs are competitive substrates of the enzyme with respect to acetohexamide. However, the plot for loxoprofen, a nonsteroidal anti-inflammatory drug with a ketone group, was apparently distant from the regression line obtained. Although nonsteroidal anti-inflammatory drugs with a ketone group such as suprofen and fenbufen were not reduced by the enzyme, they strongly inhibited the reduction of acetohexamide catalyzed by the enzyme.

Acetohexamide↗
PubMed1997

Effect of lactic acid on water content and osmotic fragility of erythrocytes in vivo.

OBJECTIVE: A coll planet centrifuge is an apparatus for the dynamic measurement of erythrocyte osmotic fragility, and it was applied to the observation of altered erythrocyte osmotic fragility induced by the lactic acid. Changes in intracellular water content of red cells were also measured according to the method, based on gas-liquid chromatography. EXPERIMENTAL DESIGN: Blood was withdrawn from the animal by cardiac puncture before and after lactic acid injection. The lactic acid was injected to rabbit through the auricular vein till the final concentration for the circulating blood was 0.7 mg/ml. RESULTS: The water content in the red cells before the lactic acid injection was between 71.37% and 73.33%. It increased after the lactic acid injection and reached the maximum of 102% of the original content. Hemolysis of erythrocytes before the injection of lactic acid began at 108.3 to 110.3 mOsm and ended at 77.0 to 81.0 mOsm, and after the injection it began at 117.0 to 120.7 mOsm and ended at 84.5 to 87.3 mOsm. CONCLUSIONS: In the present experiment the decrease in pH of the blood in lactic acid administered rabbits was too small to cause any changes in the osmotic fragility, suggesting that changes of the erythrocyte membrane properties, owing to the presence of lactic acid in the blood had occurred.

Animals↗
PubMed1997

[All-trans retinoic acid-induced myelomonocytoid differentiation in acute promyelocytic leukemia].

A 30-year-old man with a diagnosis of acute promyelocytic leukemia (APL) was admitted. Laboratory findings were as follows: WBC 32,900/microliter with 88% promyelocytes, Hb 10.4 g/dl, platelets 2.6 x 10(4)/microliter. Coagulation tests revealed DIC. Bone marrow was hypercellular with 91.8% promyelocytes which were strongly positive for peroxidase and positive for alpha-naphthyl butyrate esterase. Cytogenetic study revealed 46, XY, t(15;17) (q22:q11). He was treated with all-trans retinoic acid (ATRA) along with hydroxyurea (HU) and low-molecular weight heparin (LMH). Because his WBC increased to 93,700/microliter on day 6 of ATRA therapy, DCMP chemotherapy was given, while ATRA was withheld. He developed enterocolitis due to myelosuppression. ATRA was restarted along with granulocyte-colony stimulating factor (G-CSF). His WBC rose to 10,400/microliter with a marked, but temporary predominance of myelomonocytes both in peripheral blood and in bone marrow. These myelomonocytoid cells were positive for specific and nonspecific esterase double stainings. Then he entered complete remission. It was of interest that myelomonocytoid differentiation of APL cells was induced by ATRA. The etiology was discussed.

Adult↗
PubMed1997

Proliferative and differentiative potential of thrombopoietin-responsive precursors: expression of megakaryocytic and erythroid lineages.

We investigated changes in proliferative potential and surface markers during human megakaryocytic differentiation, using megakaryocytic cells grown by thrombopoietin (TPO). Cells grown in response to TPO from CD34+ cord blood cells in a liquid culture system expressed CD41b at a frequency of 92% and CD42b at a frequency of 80% on day 10, whereas cells expressing other lineage markers constituted less than 2.5% of this population. The cultured cells were divided into CD41b-/CD42b-, CD41b+/CD42b-, and CD41b+/CD42b+ cells. Comparison of their respective proliferative potentials showed that CD41b-/CD42b- cells generated megakaryocytic progeny in response to TPO to a lesser extent, but responded to the combination of growth factors (GFs) more intensely than CD41b+/CD42b- cells. Almost all CD41b+/CD42b+ cells failed to undergo cell division. In the culture containing GFs, some CD41b-/CD42b- cells and CD41b+/CD42b- cells gave rise to erythroid as well as megakaryocytic progeny. The potential of these cells to yield erythroid progeny in response to GFs correlated well with their expression of CD34. These results suggest that TPO generates precursors with a potential to differentiate into megakaryocytic and erythroid lineages.

Antigens, CD34↗
PubMed1997

[Functional brain mapping in motor task and somatosensory stimulation using echo planar MRI].

Functional brain mapping was performed with a 1.5T clinical MRI apparatus. Single shot gradient echo echo-planar imaging (EPI) sequence was employed. Normal volunteers were studied with the task of grasping hand or opposition of fingers at the frequency of 3 Hz, median nerve electro-stimulation, pure somatosensory stimulation by roller for acupuncture. Apparent signal increase was observed at contralateral sensorimotor cortex with motor task. Signal changes delayed about 5 seconds compared with the start and the cessation of the task, which may suggest that regional changes of CBF and blood oxygen level in capillary and/or in venule lag behind electrical excitation. It was hard to detect the activated area with median nerve electro-stimulation. On the other hand, roller stimulation provoked distinct activated areas at contralateral sensorimotor cortex. The activated areas caused by the roller stimulation and the motor task coincided entirely, which suggests the possibility of the intermixed localization of primary areas of motor and somatosensory. It was also clearly demonstrated that the activated area was broader with quick (3 Hz) and complicated motor task (finger opposition) than with slow (1Hz) and simple motor task (hand grasping).

Adult↗
PubMed1997

[Blast crisis accompanied by severe DIC of Ph negative chronic myeloid leukemia showing t(9;16) and positive M-BCR/ABL rearrangement].

A 66-year-old woman complained of chest discomfort in January 1995. In March the accelerated phase of chronic myeloid leukemia (CML) was diagnosed. Chromosomal analysis demonstrated negative Ph and positive t(9;16) (q34;p11) with positive major BCR/ABL chimeric mRNA. Administration of hydroxycarbamide was initiated, but in May she developed high fever and severe left hypochondralgia. Her WBC was 62,100/microliter (blast 64%), and LDH was 3,590 IU/l. Bone marrow examination showed 78.6% blasts, with a nucleated cell count of 74 x 10(3)/microliter. Blasts were negative for esterase stain and partially positive for both peroxidase stain and PAS reaction. Surface marker analysis revealed that blasts were positive for CD13, CD19, CD33, CD34, and HLA-DR. A diagnosis of blast crisis was made and she was treated with the VDS-CP regimen with heparin for DIC. After temporary improvement her disease recurred rapidly with severe DIC. Treatment with low molecular weight heparin and fresh frozen plasma failed to control DIC and she died of subarachnoid hemorrhage on the 48th hospital day. This is the first veprted of case Ph-negative, M-BCR/ABL-positive CML with t(9;16) accompanied by severe DIC.

Aged↗
PubMed1997

[Three-dimensional brain mapping using fMRI].

Functional mapping of the activated brain, the location and extent of the activated area were determined, during motor tasks and sensory stimulation using fMRI superimposed on 3 D anatomical MRI. Twelve volunteers were studied. The fMR images were acquired using a 2 D gradient echo echo planar imaging sequence. The 3D anatomical MR images of the whole brain were acquired using a conventional 3D gradient echo sequence. Motor tasks were sequential opposition of fingers, clenching a hand and elbow flexion. Somatosensory stimulation were administered by scrubbing the palm and sole with a washing sponge. Visual stimulation consisted of full visual field stimulation. Data were analyzed by the cross-correlation method. Transversal fMR images and anatomical images were reconstructed using both volume-, surface-rendering methods, and reconstructed for coronal and sagittal sections. Activated areas were expressed using the three primary colors. Motor tasks activated the contralateral primary motor area (M1), the primary somatosensory area (S1) and the supplementary motor area (SMA). Somatosensory tasks activated the contralateral S 1, M1 and secondary sensory area (S2). Activated areas during full visual field stimulation was observed in the bilateral occipital lobe, including both the primary cortex. Three-dimensional brain mapping allowed visualization of the anatomical location and extent of the activated brain during both motor task and sensory stimulation. Using this method we could obtain a functional map similar to the Penfield's schema.

Adult↗
PubMed1997

Direct labeling of macroaggregated albumin with indium-111-chloride using acetate buffer.

UNLABELLED: Indium-111-labeled macroaggregated albumin (MAA) would be suitable for combined pulmonary perfusion and ventilation scan using a 99mTc ventilation agent. METHODS: MAA suspended in 0.1 M sodium acetate buffer, pH 5.8, was incubated with 111In-chloride for 30 min at room temperature. An in vitro study of the obtained 111In-MAA was performed for labeling efficiency and stability in human normal serum. The 111In-MAA was intravenously injected into normal mice, and the biodistribution was studied at 15 and 180 min postinjection. A gamma camera image was obtained at 15 min after injection. RESULTS: MAA was directly and stably labeled with 111In-chloride, and the labeling efficiency of the preparation was more than 96%. More than 90% of the administered 111In-MAA was caught in the murine lung. The scintigraphy with 111In-MAA showed a clearly visualized murine lung. CONCLUSION: Indium-111-MAA can be conveniently prepared by direct labeling at room temperature. It provides an alternative perfusion tracer for combined perfusion-ventilation imaging.

Animals↗
PubMed1997

Ectopic bone formation by biphasic calcium phosphate (BCP) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2).

We investigated ectopic bone formation by biphasic calcium phosphate (BCP) combined with recombinant human bone morphogenetic protein-2 (rhBMP-2) in the rat dorsum. Under reduced pressure, rhBMP-2 was adsorbed onto BCP, which consisted of 80% beta-tricalcium phosphate and 20% hydroxyapatite uniformly distributed in granules. Twenty Wistar rats were separated into 4 groups consisting of 5 animals each dosed with 2, 10, and 50 micrograms/700 microliters of rhBMP-2 and a control group (BCP only). Pieces of the BCP-BMP complex or only BCP were implanted under the dorsal skin of the rats. Histological sections were examined three weeks later. New bone was formed in all rats given 50 micrograms doses, but not in the 2 micrograms and control groups. These results indicated that BCP combined with rhBMP-2 induced ectopic bone formation without additional carriers. Therefore, BCP granules alone can function as carriers for rhBMP-2 to induce bone formation.

Adsorption↗
PubMed1996

The effect of systemic and central nitric oxide administration on milk availability in lactating rats.

This study examined the effect of nitric oxide (NO) on milk transfer in rats. Pups nursed by mothers that received chronic systemic injections of sodium nitroprusside (SNP) weighed significantly less than pups of mothers treated with either saline or N omega-nitro-L-arginine (NNLA). Intracerebroventricular injection of SNP or L-arginine (L-arg) but not NNLA or saline, caused a significant reduction of milk transfer from mother to pups after a 12 h separation period. Systemic oxytocin (OT) injection reversed the effect of central injection of SNP. Furthermore, SNP and L-arg inhibited, whereas NNLA permitted the characteristic milk ejection burst of OT neurones without changing myoepithelial tissue response to systemic OT. These observations suggest that NO may be involved in the regulation of milk ejection bursts and milk transfer.

Animals↗