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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 289 records · Page 16Linked to original sources

Pericardial fluid as an alternative specimen to blood for postmortem toxicological analyses.

In actual forensic cases, we occasionally encounter victims with their blood being completely lost. In this study, pericardial fluid has been proposed as a specimen for toxicological analysis, and its utility has been evaluated. Fifteen autopsy cases with little putrefaction were selected. Fairly good correlations were observed between blood and pericardial fluid for all drugs, neutral and basic drugs and acidic drugs with regression equations of y=1.09x - 0.086 (r=0.989, n=21), y=0.969x - 0.072 (r=0.993, n=16) and y=1.01x + 0.355 (r=0.970, n=5), respectively. The correlations of drug concentrations between blood and cerebrospinal fluid/femoral muscle were not as good as those between blood and pericardial fluid. No correlations were observed between blood and urine/bile. The ratios of pesticide concentrations in each specimen to those in blood showed a large variation. Although our study was limited to a small number of cases, we have concluded that pericardial fluid is a good sample for quantitative confirmation of analyses performed on blood samples or a quantitative alternative to blood in exsanguinated victims. Cerebrospinal fluid, urine, bile and the skeletal muscle were found to be suitable only for qualitative analyses.

Journal Article↗

Concentrations of morphine and codeine in urine of heroin abusers.

We have measured concentrations of morphine, codeine and 6-monoacetylmorphine in urine of people admitted to the Los Angeles County + University of Southern California Medical Center. Of 60 patients positive for morphine and/or codeine, 10 were judged to be heroin abusers based on positive results for 6-monoacetylmorphine, a specific metabolite of heroin. In nine of these ten patients, 0.028-39.4 microg/ml free codeine and 0.070-307 microg/ml total codeine were detected along with 1.74-218 microg/ml of free morphine and 11.2-2870 microg/ml of total morphine; the morphine-to-codeine ratios were 3.65-228 and 2.27-207 for the free forms and total amounts of these opiates, respectively. In the one patient who was negative for codeine, the concentrations of free and total morphine were 0.114 and 2.22 microg/ml, respectively. Based on our data and literature data available, the following criteria are proposed for judging heroin use from the results of urinalysis, especially when no 6-monoacetylmorphine is detected: (1) a detectable amount of free morphine exists and the concentration of total morphine is higher than 10 microg/ml; (2) a detectable amount of codeine exists; and (3) the morphine-to-codeine ratio is higher than 2 for both the free forms and total amounts of these opiates.

Journal Article↗

Vitrectomy for macular edema combined with retinal vein occlusion.

This study was performed in order to evaluate the effect of vitrectomy in eyes with retinal vein occlusion associated with macular edema. Twenty-nine years eyes (27 patients) with branch retinal vein occlusion (BRVO), and 14 eyes (13 patients) with central retinal vein occlusion (CRVO) both associated with macular edema underwent phacoemulsification, intraocular lens implantation, pars plana vitrectomy and peeling of the posterior hyaloid membrane. Follow-up ranged from 12 to 32 months. Macular edema was reduced, and visual improvement was observed (p < 0.0001 in BRVO, p = 0.0257 in CRVO, paired t-test). Visual outcome was better in eyes with better visual acuity before surgery. Early vitrectomy may be recommended for retinal vein occlusion associated with macular edema.

Aged↗

Cystotomy for diabetic cystoid macular edema.

The purpose of this study was to evaluate the role of vitrectomy with cystotomy in the treatment of diabetic cystoid macular edema (CME). Among 22 eyes of 21 patients with diabetic CME underwent phacoemulsification, intraocular lens implantation, pars plana vitrectomy, induction of posterior vitreous detachment, and cystotomy or cystectomy. Follow-up ranged from 3 to 29 months. Under biomicroscopic examination, Cystoid macular edema was eliminated in 16 of 22 eyes during the follow-up period. Ring-shaped residual edema was observed in one eye. Corrected visual acuity improved in 7 of 22 eyes by more than one Snellen line (P = 0.0391, paired t-test), remained the same in 13 eyes, and decreased by more than one line in 2 eyes. This pilot study shows that cystotomy may have a role in the treatment of cystoid macular edema in diabetic patients.

Aged↗

Distribution characteristics of levofloxacin and grepafloxacin in rat kidney.

PURPOSE: To elucidate the renal distribution of quinolones, we examined the uptake of levofloxacin and grepafloxacin in vivo and in rat renal cortical slices. METHODS: The plasma and various tissue concentrations of levofloxacin and grepafloxacin were measured after a bolus injection in rats, and tissue uptake clearance was calculated. Transport characteristics of quinolones in rat renal cortical slices were evaluated. RESULTS: The tissue distribution of levofloxacin and grepafloxacin in the kidney was greater than in any other tissue, and the tissue uptake clearances of levofloxacin and grepafloxacin in the kidney cortex were 1.2 and 4.6 ml/min/g tissue, respectively. The uptake of levofloxacin and grepafloxacin in rat renal cortical slices was concentrative, as indicated by slice/medium ratios of 2.3 and 9.6 at 60 min, respectively. The uptake of levofloxacin and grepafloxacin in rat renal cortical slices showed saturation, and was significantly inhibited in the presence of quinidine (p<.05), but not of tetraethylammonium or p-aminohippurate. CONCLUSIONS: Renal distribution of levofloxacin and grepafloxacin may be mediated by a specific transport system for quinolones, distinct from the organic cation and organic anion transport systems in the kidney.

Animals↗

Effects of glibenclamide on glycylsarcosine transport by the rat peptide transporters PEPT1 and PEPT2.

1 Glibenclamide is a widely used sulphonylurea for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). This agent has been reported to inhibit the activities of various ion channels and transporters. In the present study, we examined the effects of glibenclamide on the function of the H+/peptide cotransporters PEPT1 and PEPT2 by using stable transfectants. 2 Uptake of [14C]-glycylsarcosine, a typical substrate for peptide transporters, by PEPT1- or PEPT2-expressing transfectant was inhibited by glibenclamide as well as other sulphonylureas including tolbutamide. 3 Kinetic analysis revealed that the inhibition by glibenclamide was noncompetitive. Dixon plot analyses showed that the Ki values of this agent were 25 and 7.8 microM for PEPT1 and PEPT2, respectively. 4 Glibenclamide did not inhibit Na+-coupled alanine and alpha-methyl-D-glucoside transport, suggesting that the inhibitory effects of glibenclamide on peptide transporters were not due to nonspecific interactions. 5 There was little uptake of [3H]-glibenclamide by PEPT-expressing transfectants as compared to mock-transfected cells, suggesting that glibenclamide was not a substrate for these peptide transporters. 6 In summary, glibenclamide inhibited the [14C]-glycylsarcosine transport by PEPT1 and PEPT2 in a noncompetitive fashion, although glibenclamide per se was not transported through these transporters. These findings would provide important information for clinical, physiological and biochemical aspects of peptide transporters.

Alanine↗

The role of Ets family transcription factor PU.1 in hematopoietic cell differentiation, proliferation and apoptosis.

The PU.1 gene encodes an Ets family transcription factor which controls expression of many B cell- and macrophage-specific genes. Expression of the gene is critical for development of lymphoid and myeloid cell lineages, since PU.1-deficient mice exhibit defects in the development of these cell lineages. The PU.1 gene is identical to the Spi-1 gene isolated from common proviral integration sites in Friend virus-induced murine erythroleukemia (MEL), and deregulated expression of the gene is believed to be an essential step of the disease. We recently demonstrated that overexpression of PU.1 inhibits erythroid differentiation of MEL cells induced with the differentiating agent DMSO. We also noticed unexpectedly that overexpression of PU.1 together with DMSO induces marked growth arrest and apoptosis in MEL cells, supporting the notion that some oncogenes induce growth inhibition and apoptosis rather than cell proliferation and transformation under specific circumstances as shown with the c-myc gene. In this review, the role of PU.1 in hematopoietic cell differentiation, proliferation and apoptosis is described and the possible molecular mechanisms of PU.1-induced effects in MEL cells are discussed.

Animals↗

Programmed cell death in normal epidermis and loricrin keratoderma. Multiple functions of profilaggrin in keratinization.

The terminal differentiation of epidermal keratinocytes has been regarded as an example of programmed cell death. Among the proteins specifically expressed in this process is profilaggrin, which consists offilaggrin repeats and N- and C-terminal domains. Profilaggrin is proteolytically processed into individual domains during the terminal differentiation. Filaggrin released from profilaggrin aggregates keratin filaments to form compacted cornified cells with a keratin pattern. A recent transfection experiment has indicated initiation of cell death by filaggrin expression constructs. The transitional cells between the granular and cornified cells show morphologic characteristics of apoptotic cells, and their nuclei contain fragmented DNA and profilaggrin N-terminal domains. This suggests that the N-terminus of profilaggrin may participate in nuclear events accompanying programmed cell death. Among inherited skin disorders with abnormal keratinization, progressive symmetric erythrokeratoderma is caused by loricrin mutation (loricrin keratoderma). In this disease, profilaggrin N-terminal domains are aggregated with mutant loricrin within condensed nuclei. These nuclei persist in the cornified layer as parakeratosis. Loricrin keratoderma could therefore be regarded as a representative form of disrupted cell death.

Animals↗

Analysis of the immunoglobulin heavy chain gene variable region of 101 cases with peripheral B cell neoplasms and B cell chronic lymphocytic leukemia in the japanese population.

We have analyzed the immunoglobulin heavy chain (VH) gene variable regions (CDR2 and FW3) of 101 Japanese cases with peripheral B cell neoplasms. When all except one case with a deletion were graphed by frequency of replacement mutation, the 100 cases could be separated into two groups: 24 cases with zero, one and two mutations (germline or low frequency of somatic mutation); and 76 cases with three or more mutations (medium to high frequency of somatic mutation). While most mantle cell lymphoma cases (11/13) showed germline or low frequency of somatic mutation, all cases of mucosa-associated lymphoid tissue (MALT) lymphoma (11/11), follicular lymphoma (three of three cases), plasma cell myeloma (seven of seven cases) and most cases of diffuse large B cell lymphoma (DLBCL; 42/47) belonged to the latter group. These 76 cases, therefore, may be considered to show somatic hypermutation. More than half of chronic lymphocytic leukemia/small lymphocytic lymphoma cases (CLL/SLL; eight of 13) showed a hypermutated VH gene and the ratio of replacement mutation: silent mutation in CDR2 of CLL/SLL was considerably higher compared with DLBCL and MALT lymphoma, showing somatic hypermutation. When comparing VH gene type of B cell-CLL (B-CLL) among our series and those in the literature, more cases of CD5+ B-CLL in the Western literature have the VH5 and VH6 family types, while more cases in Japan are reported to have VH4 family. The occurrence of VH families in B-CLL between Japanese and Western people seems to be comparable.

Aged↗

Tumor cell growth suppression by tannic acid.

Tannic acid was cultured together with tumor cells that had originated from human malignant tumors (HCT-15 & AGS). Significant suppression of tumor growth was observed. The 50% suppression was observed at the concentration between 50 micrograms/ml and 12.5 micrograms/ml. When tannic acid was injected into HCT-15 cells by electroporation at 1180 mu p and 200 ohm, the suppression rate was 34.3% at the concentration of 50 micrograms/ml in HBS solution. The suppression rate of cells only in contact with tannic acid solution for one hour under the same conditions as used for electroporation, was 26.1%. Histographic findings suggested that tannic acid almost completely blocked the S phase of the cell cycle.

Adenocarcinoma↗

Tannic acid raises survival rate of mice bearing syngeneic tumors.

Tannic acid which was found earlier to have growth suppressive activity against cultured tumor cells, was given to Balb/c mice p.o. The mice had been inoculated with syngeneic tumor cells (Meth/A) i.p. When tannic acid was suspended in drinking water and given daily at doses of approximately 875 mg/kg/day and 1750 mg/kg/day, the respective survival rates were 59% and 48%, with that of the control mice being 29%. To study the cytotoxicity of tannic acid, we administered the tannic acid to mice at 875 and 1750 mg/kg/day for 35 days. The weight gain for each dose was lower than that of the control, although the difference was not significant. When tannic acid was given at 8750 mg/kg/day, the weight gain was significantly lower than the control. A histologic study did not show any pathological findings in the kidney, liver, or lungs in the mice given tannic acid at the above doses.

Administration, Oral↗

Effect of gold on tumor-associated antigens.

A gold compound, which is an anti-rheumatoid agent, was clinically applied to patients showing a high level of tumor-associated antigens. Two patients showed no clear evidence of recurrence except for a high level of tumor-associated antigens. The gold compound was injected i.m. every week at the dose of 25 mg/body for 10 times to a patient showing a high CEA level that had arisen eight years after cervical dissection for a tongue carcinoma. It was also administered every other week for 30 times at the dose of 25 mg/body to a patient showing high CA19-9 and SLX levels five years after palliative left pulmonary resection followed by radiation therapy for left pulmonary carcinoma. The CEA level dropped to the normal limit after 10 injection and remained at that level after cessation of the gold treatment. SLX and CA19-9 levels of the second patient showed lower than initial values, although SLX did not fall to the normal range after the 30 injections. No side effects such as lowering of white blood cell count, BUN elevation, or kidney dysfunction were seen.

Aged↗

Identification and characterization of a new intermediate in the ribosylative inactivation pathway of rifampin by Mycobacterium smegmatis.

Mycobacterium smegmatis DSM 43756 inactivates rifampin by ribosylation. To study this process of rifampicin, all possible inactivated forms of the antibiotic were extracted and purified. Structural studies showed the presence of a new inactivation product, designated RIP-TAp(23-phosphoribosyl-rifampin). Formation of 23-(O-ADP-ribosyl)rifampin (RIP-TAs) is the first step, followed by removal of AMP to give rise to the newly identified compound. Lastly, dephosphorylation leads to formation of 23-ribosyl-rifampin (RIP-Mb). Feeding experiments with the ADP-ribosylated antibiotic obtained from the cell homogenates of an Escherichia coli strain carrying the cloned M. smegmatis gene confirmed this rifampin inactivation process.

Antibiotics, Antitubercular↗

I.v. lidocaine worsens histamine-induced bronchoconstriction in dogs.

We have assessed the effect of lidocaine (lignocaine) on histamine-induced bronchoconstriction by direct visualization with a superfine fibreoptic bronchoscope. Seven mongrel dogs were anaesthetized with pentobarbital (pentobarbitone) 30 mg kg-1 followed by 2 mg kg-1 h-1 and pancuronium 200 micrograms kg-1 h-1. The trachea was intubated with a tracheal tube containing a second lumen for insertion of a 2.2-mm fibreoptic bronchoscope. This allowed estimation of the bronchial cross-sectional area (BCA) of the third bronchial bifurcation of the right lung. We used NIH image, a public domain image processing and analysis program. Bronchoconstriction was produced with a bolus dose of histamine 10 micrograms kg-1 i.v. followed by continuous infusion of 500 micrograms kg-1 h-1. After 30 min the following i.v. doses of lidocaine were given: lidocaine 0 (saline), 0.01, 0.1, 1.0 and 10 mg kg-1 at 10-min intervals. BCA was assessed 90 s after each dose. Arterial blood sampling was performed for measurement of plasma catecholamines. Lidocaine 1.0 and 10 mg kg-1 significantly reduced histamine-decreased BCA from 69.7 (SEM 4.1)% to 59.8 (7.3)% and 34.3 (6.8)%, respectively. Plasma concentrations of catecholamines decreased significantly after lidocaine 10 mg kg-1 i.v. In addition, there was a significant correlation between percentage decreases in plasma concentrations of epinephrine (adrenaline) and norepinephrine (noradrenaline) and reduction in %BCA (epinephrine-BCA, P < 0.01, r = 0.674; norepinephrine-BCA, P < 0.01, r = 0.510). This study suggests that i.v. lidocaine may exacerbate histamine-induced bronchoconstriction by a sympatholytic effect. This may have therapeutic implications for patients with acute asthma or anaphylactic shock who may become dependent on circulating catecholamines.

Anesthetics, Intravenous↗

Low-dose succinylcholine facilitates laryngeal mask airway insertion during thiopental anaesthesia.

We have assessed the optimal dose of succinylcholine to provide satisfactory conditions for insertion of a laryngeal mask airway (LMA) without causing myalgia during induction of anaesthesia with thiopental. We studied 60 adult patients, allocated randomly to one of three groups: group 1 (n = 20) received normal saline, group 2 (n = 20) received succinylcholine 0.25 mg kg-1 and group 3 (n = 20) received succinylcholine 0.5 mg kg-1. Insertion of the LMA was performed 1 min after administration of succinylcholine or saline. Insertion conditions were significantly better in group 3 compared with groups 1 and 2. The incidence of adverse responses on insertion was significantly higher in groups 1 and 2 than in group 3. Four of 20 patients (20%) in group 3 complained of myalgia, which was higher than that in group 1 (0%) and group 2 (10%), but there were no significant differences between groups on the day of operation. On day 3 after operation, seven patients (35%) in group 3 complained of myalgia, which was significantly higher than that in group 1 (5%) and group 2 (20%). Time from administration of succinylcholine to resumption of spontaneous respiration was significantly longer in groups 2 (194.9 (SD 50.4) s) and 3 (234.2 (34.3) s) than in group 1 (84.7 (32.4) s). There was also a significant difference between groups 3 and 2 for duration of apnoea.

Adult↗

Relaxant effect of propofol on the airway in dogs.

Propofol has been suggested to produce airway relaxant effects in vivo, although the mechanism is unclear. We have evaluated the bronchodilating effect of propofol using a direct visualization method with a superfine fibreoptic bronchoscope. We studied 21 mongrel dogs anaesthetized with pentobarbital 30 mg kg-1 i.v. and pancuronium 0.2 mg kg-1 h-1. The animals were allocated randomly to one of three groups (n = 7 in each): propofol group, atropine-propofol group and histamine-propofol group. The trachea was intubated using a tracheal tube that had a second lumen for insertion of the bronchoscope to monitor continuously bronchial cross-sectional area (BCA). BCA was measured using the NIH Image program. In the propofol group, dogs were given the following doses of propofol at 10-min intervals: 0 (saline), 0.2, 2.0 and 20 mg kg-1 i.v. In the atropine-propofol group, saline, atropine 0.2 mg kg-1 and propofol 20 mg kg-1 were given at 10-min intervals. In the histamine-propofol group, bronchoconstriction was elicited with histamine 10 micrograms kg-1 and 500 micrograms kg-1 h-1 until the end of the experiment. Thirty minutes after the start of infusion of histamine, propofol (0, 0.2, 2.0 and 20 mg kg-1) was administered. Changes in BCA were expressed as percentage of basal area. Histamine decreased BCA by 39.2 (SEM 5.4%). Propofol increased significantly basal and histamine-decreased BCA in a dose-dependent manner by 18.4 (4.5%) and 15.8 (4.9%), respectively after 20 mg kg-1 i.v. However, propofol following atropine i.v. did not increase BCA (129.9 (8.2)% after atropine vs 125.7 (8.9)% after propofol). Therefore, the relaxant effect of propofol may be a result of reduction in vagal tone.

Anesthetics, Intravenous↗

Isolation and characterization of a novel HS1 SH3 domain binding protein, HS1BP3.

We have isolated a novel gene, HS1BP3, which encodes an HS1 binding protein. Analysis of HS1BP3 cDNA indicates several potentially important segments, including a PX domain, a leucine zipper, immunoreceptor tyrosine-based inhibitory motif-like motifs and proline-rich regions. HS1BP3 associates with HS1 proteins in vivo as confirmed by immunoprecipitation in B and T cell lines. HS1BP3 preferentially associates with the HS1 SH3 domains rather than with other SH3 molecules, suggesting a role of HS1BP3 as an HS1 signaling mediator. Overexpression of mutant HS1BP3 protein in T cell lines results in decreased IL-2 production. Our data suggest a novel role for HS1BP3 in lymphocyte activation.

Adaptor Proteins, Signal Transducing↗