Biomedical subjects

Y Morimoto

Publications and source records attributed to Y Morimoto.

At least 145 records · Page 8Linked to original sources

PubMed2000

[Congenital hydronephrosis detected by prenatal ultrasonography: the effect of pyeloplasty on renal function].

PURPOSE: Prenatal detection of congenital hydronephrosis has raised new questions with regard to the need of management and the indications for operation. Moreover, there is considerable controversy whether or not pyeloplasty improves long-term renal function. We evaluated the operative results of this entity under the setting of well defined indications for surgery. MATERIALS AND METHODS: The indications for pyeloplasty included Society for Fetal Urology-grade (SFU-grade) 3 and grade 4 hydronephrosis on ultrasonogram together with obstructive pattern on modified "Well Tempered" diuretic renogram. We analysed the postoperative changes of ultrasonographic findings, differential renal function, and renogram patterns in 28 children with unilateral hydronephrosis detected prenatally. RESULTS: Of the patients, 27 had grade-4 hydronephrosis on preoperative ultrasonogram. Pyeloplasty was effective in decreasing the grade of dilatation in all kidneys except one. Of the involved renal units, 14 (50%) had reduced differential renal function less than 45% on the preoperative renogram. Differential renal function increased significantly by absolute value of 5% or greater in 8 kidneys (29%), but decreases in 5 kidneys (18%). In the remaining 15 kidneys (54%) there was no significant differences between pre- and post-operative differential renal function. Postoperative diuretic renogram changed to non-obstructive pattern in 26 kidneys (93%). Another 2 kidneys showed hypofunctioning pattern. CONCLUSIONS: The results suggest that, although pyeloplasty decreases ultrasonographic dilatation of hydronephrosis and improves excretory pattern of diuretic renogram, significant increase of differential renal function is expected in only one third of the involved kidneys.

Humans↗

PubMed2000

Novel assay for measuring serum conjugated bilirubin and its clinical relevance.

We have developed a new enzymatic assay for the determination of conjugated bilirubin (Bc) using stable liquid reagents. In this assay, only Bc is selectively oxidized by bilirubin oxidase at pH 5. 0 in the presence of nitrilotris (methylenephosphonic acid) trisodium salt, ethylenediaminetetraacetic acid disodium manganese (II) salt, and 4-hydroxy-2,2,6,6,-tetramethylpiperidine 1-oxyl. Bc is quantitatively determined from a decrease in the absorbance at 450 nm caused by Bc oxidization. The reagent solutions of the assay were developed so that they could be stably stored for one year together with bilirubin oxidase, in order to eliminate the need to prepare working solutions every time they are required. The assay has good reactivity, differentiability, measurability, and precision. Neither ascorbic acid nor hemoglobin interfered with the measurement. Bc values determined by the assay reflected more clearly the pathophysiological condition of hepatobiliary disease patients with jaundice than the values of total bilirubin or direct bilirubin determined by conventional methods. From these observations, we concluded that this Bc assay is valuable for the evaluation of jaundice.

Bilirubin↗

PubMed2000

[Hypercapnea after minitracheotomy].

Minitracheotomy is a useful procedure for the respiratory management of patients with sputum retention observed frequently in chronic lung disease and postoperative respiratory failure. However, we experienced a case of hypercapnea after minitracheotomy. An 83-year-old woman was scheduled for gastrectomy. She had respiratory failure of Hugh-Jones 5 with fibroid lungs and the infection with atypical Mycobacterium and MRSA. Her sputum was adhesive and showed persistent increase during pre- and intra-operative periods. After the operation, minitracheotomy was carried out against the sputum retention by using Portex Mini-Trach II kit. Hypercapnea, however, was observed in spite of no evidence of the surgical complications such as bleeding or inadequate care for sputum from the inserted tube. Bronchofiberscope revealed adhesive sputum stuck to the space between the inserted tube and the trachea. In this case, hypercapnea was improved by opening the top of the inserted tube and frequent care for sputum. In cases with a large amount of adhesive sputum, sputum retention may easily occur not only at the peripheral bronchial branch but also between the inserted tube and the trachea and it can cause hypercapnea which may be overlooked.

Aged↗

PubMed2000

[Surgical stress and CARS: involvement of T cell loss due to apoptosis].

The term compensatory anti-inflammatory response syndrome(CARS) is the cytokine antagonist cascade which down-regulates the inflammatory cascade that appeared to contribute to the onset of bacterial infection. CARS represents immunosuppression, in which state reduced numbers of T cells in blood were encountered. Here we have determined whether this T cell loss is a consequence of bacterial antigen-mediated activation-induced cell death(AICD). By flowcytometric analysis, less than 0.3% of freshly isolated T cells from healthy volunteers and patients with severe pneumonia were identified as apoptosis. However, during culture, the rate of apoptosis in peripheral blood T cells from patients was 3.0 + 0.9%, and increased further in the presence of anti-CD3(7.4 + 2.1%) and decreased when IL-2 was added(4.4 + 1.3%). In contrast, there were no changes observed in healthy volunteers on addition of anti-CD3. Further, anti-CD3 significantly increased susceptibility to apoptosis of CD45RO+ T cells, but not CD45RA+ T cells from patients. Collectively, these findings demonstrated that bacteria-reactive T cells were more susceptible to AICD, and AICD of CD45RO+ T cells, therefore, provides an explanation for the loss of bacteria-reactive T cells during CARS.

Apoptosis↗

PubMed2000

[Patent blue-induced false-methemoglobinemia].

We experienced an anesthetic case, in which interference in oxygen saturation values by patent blue was mistaken for nitroglycerin-induced methemoglobinemia. A 40-year-old woman underwent mastectomy for breast cancer under general anesthesia. Nitroglycerin was infused to produce hypotensive anesthesia. Patent blue was locally injected around the cancer by a surgeon and surgery was started. A few minutes later, oxygen saturation by finger pulse oximeter suddenly decreased from 100% to 90%. And then, blood gas analysis was performed to confirm this change. The decrease of oxygen saturation and the increase of methemoglobin were also observed in the finding of blood gas analysis. At first, we judged these changes as methemoglobinemia by nitroglycerin infusion. Finally, however, we concluded that all these changes were attributable to the interference by patent blue on oxygen saturation value because we found that there had been some inconsistent findings as methemoglobinemia. The fact seems that nothing happened to the patient during the episode. This case showed us that anesthesiologists should understand the principle of hematological monitors and the meaning of the data obtained by monitors.

Adult↗

PubMed2000

[Efficacy of patient-controlled epidural analgesia using a disposable PCA device].

We evaluated efficacy of patient-controlled epidural analgesia (PCEA) using a disposable PCA device (3.0 ml type). Twenty-two patients for elective gynecological surgery were randomized into two groups. Patients of the continuous epidural group received epidural fentanyl (15 micrograms.ml-1) with bupivacaine (1.25 mg.ml-1) from a disposable infusion pump (infusion rate: 2.1 ml.hr-1). Patients of the PCEA group received the same anesthetic solution from the same infusion pump serially connected to the disposable PCA device. There were no significant differences in postoperative visual analogue scale (VAS) scores at rest and with movement between the two groups. However, VAS scores significantly decreased from 6.8 +/- 1.6 to 1.0 +/- 1.3 when the PCA device was used for severe pain. This suggests that segmental analgesic effect might be obtained by diffusion of anesthetic solution in the epidural space after 3.0 ml PCEA bolus administration. The incidences of side effects were similar in both groups. Respiratory depression and sedative effects were not observed in both groups. We conclude that PCEA using a disposable PCA device (3.0 ml type) seems to be effective for postoperative pain relief.

Adult↗

PubMed2000

[Perioperative management for emergency cesarean section of a patient with reexpansion pulmonary edema].

A 27-year-old woman with 39 week gestation was admitted because of cough and dyspnea accompanied by massive right-sided pleural effusion. Following the right thoracocentesis, about 2000 ml of bloody pleural effusion was drained. Just after the thoracocentesis, the fetal heart rate (FHR) temporarily showed a variable deceleration pattern but the rate was restored spontaneously. One hour later, cough and dyspnea became worse. Changes in FHR pattern indicated the premature separation of the normally implanted placenta. Accordingly, an emergency cesarean section was performed under general anesthesia. Massive foamy tracheal secretion was drained from the tracheal tube during surgery. As her chest X-ray showed signs of pulmonary edema in the right lung, her status was diagnosed as reexpansion pulmonary edema (RPE). She was transferred to the intensive care unit and treated with mechanical ventilation, prednisolone and diuretics. Extubation was performed on the 2nd day after the surgery. On reexpansion of the collapsed lung, it is always necessary to consider not only the hemodynamic changes just after reexpansion but also RPE following reexpansion.

Adult↗

PubMed2000

[Propofol anesthesia for ambulatory surgery in adults].

We reported 131 cases of ambulatory surgery in adults mainly anaesthetized with propofol infusion. Without any premedication, anesthesia was induced with propofol and fentanyl. A laryngeal mask airway was inserted using intravenous injection of vecuronium. Anesthesia was maintained with continuous infusion of propofol and intermittent fentanyl administrations, and local anesthetic infiltration was combined. All patients received air and oxygen mixture (FIO2 0.4) throughout the procedure. During surgery, metoclopramide and flurbiprofen axetil were given to prevent postoperative pain, nausea and vomiting. After surgery, patients were observed at the daycare unit in ward. Average age was 42 years and ASA risk was 1.3. Operation time and anesthesia time and hospital stay were 43.4 minutes, 70.6 minutes and 332 minutes, respectively. In 25 patients (19%) analgesics were needed for postoperative pain. Although 3 patients (2.3%) were unsuccessful as ambulatory surgery due to excessive pain, all patients including these three could be discharged within 24 hours after surgery. We conclude that combined anesthesia with propofol, fentanyl and local anesthetic is suitable for ambulatory surgery in adults.

Adult↗

PubMed2000

Characterization of sphingolipid long-chain base kinase in Arabidopsis thaliana.

Sphingolipid long-chain base (LCB) kinase catalyses the phosphorylation of sphingolipid LCB to form LCB 1-phosphate. Based on sequence identity to a murine sphingosine kinase (murine SPHK1a), we isolated and characterized a LCB kinase-like cDNA in Arabidopsis thaliana. The deduced amino acid sequence of the homologous cDNA shows several regions that are highly conserved in LCB kinases from mouse, yeast, human and Caenorhabditis elegans. These regions are not similar to those of other known kinase families. For a functional identification, the homologous cDNA from A. thaliana was expressed in Escherichia coli, and LCB kinase activity was measured. The recombinant AtLcbk1 protein was found to utilize ATP and sphinganine. These results indicate the first identification of a gene coding for a LCB kinase in plants.

Arabidopsis↗

PubMed2000

[A case of pulmonary fibrosis with many asbestos bodies in bronchoalveolar lavage fluid after exposure to asbestos and man-made mineral fibers].

We report a case of severe pulmonary fibrosis in a patient exposed to asbestos and other natural and man-made mineral fibers (MMMF) over a period of time. A 63-year-old man was admitted to our hospital because of progressive dyspnea and severe hypoxemia with hypercapnea. Mineral fibers recovered by bronchoalveolar lavage were analyzed by scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (SEM-EDS). The bronchoalveolar lavage fluid (BALF) included a large number of asbestos bodies (116,000/ml). The cores of the asbestos fibers were crocidolite, and no vitreous fibers nor other kinds of man-made mineral fibers (MMMFs) were identified. To our knowledge, the number of asbestos bodies per ml of this patient's BALF is the greatest ever reported. Insufficient personal protection of the airways, high concentrations of inhaled fibers, co-exposure to cigarette smoke, and prolonged biopersistence of crocidolite asbestos fibers are presumed to be the causes of such severe asbestosis.

Asbestos↗

PubMed2000

[Examination of reason to make being at home death difficult--from 42 patients died at home treatment].

On the basis of 42 patients who used temporary nursing at home before death from February 1993 to May 2000, we examined various factors thought to influence home and hospital deaths. As a result, we realized the rates of home deaths increased since the establishment of the visit nursing section. We think that the maintenance and understanding of home medical treatment and the visit system on the part of the service providers and is necessary to realize home death.

Aged↗

PubMed2000

[Tracheal tube damage by Harmonic Scalpel during tonsillectomy].

We experienced a case in which a tracheal tube was damaged by a Harmonic Scalpel during tonsillectomy. A 33-year-old man with chronic tonsillitis underwent tonsillectomy under general anesthesia. The trachea was intubated by Polar Preformed Tracheal Tube (Polar tube). About 45 minutes after the start of surgery, sudden massive air leakage in the trachea occurred. Surgery was accomplished under oral suctioning. After extubation, we found that an inflation cuff tube was cut off by the Harmonic Scalpel. The cause of damage was the position of an inflation cuff tube which had been in the dorsal side of the tracheal tube (near the surgical field) in the Polar tube. Anesthesiologists should be aware of the characteristics of the surgical equipment newly introduced.

Adult↗

PubMed1999

Analysis of skin disposition of flurbiprofen after topical application in hairless rats.

Cutaneous disposition of topically applied flurbiprofen (FP) was evaluated using a new in situ experimental model in hairless rats. A disk-shaped agar gel (3.85 cm in diameter and 0.5 cm in thickness) was subcutaneously implanted in the abdominal region of rats as a drug receptor, and a drug donor cell was subsequently placed above this agar gel. No significant pharmacokinetic modification of FP was observed as a result of this experimental procedure. A bolus injection and a constant intravenous infusion of FP were applied to the rats, followed by an analysis of FP levels in the plasma and agar gels. Using these results, the clearance rate of FP from the systemic circulation to the gel could be calculated. FP (1% gel formulation, 1.0 g/3.14 cm(2)) was then topically applied to the skin of these rats. From these experiments, the amount of FP that migrated from the formulation to the systemic circulation and the amount of FP that migrated directly to the agar gel across the skin, over 10 h, were separately evaluated to be 235.4 and 2.0 microg, respectively. Thus, most of the FP was absorbed into the systemic circulation. The effect of endogeneous vasoactive compounds and penetration enhancers on the FP disposition within skin was also determined. Epinephrine and bradykinin were used as vasoactive compounds that were entrapped in agar gel, and an isopropyl myristate system (IPM system) and a l-menthol-ethanol-glycerin-water system (MEGW system) were used as enhancers in the formulation. Epinephrine enhanced the direct delivery of FP into the agar gel to more than ten times its former level, in spite of the fact that it had no effect on systemic delivery. Bradykinin strengthened systemic delivery slightly, without changing the quantity of FP in the gel. IPM increased only the systemic delivery of FP, as was the case with bradykinin, whereas the MEGW system markedly increased both the blood concentration and the quantity of FP in the gel (13 and 200 times, respectively). This technique has proven to be an effective tool for the quantitative evaluation of cutaneous disposition of a topically applied drug.

Administration, Cutaneous↗

PubMed1999

Simultaneous transport and metabolism of ethyl nicotinate in hairless rat skin after its topical application: the effect of enzyme distribution in skin.

An in vitro permeation study of ethyl nicotinate (EN) was carried out using excised hairless rat skin, and simultaneous skin transport and metabolism of the drug were kinetically followed. Fairly good steady-state fluxes of EN and its metabolite nicotinic acid (NA) through the skin were obtained after a short lag time for all the concentrations of EN applied. These steady-state fluxes were not proportional to the initial donor concentration of EN: EN and NA curves were concave and convex, respectively, which suggests that metabolic saturation from EN to NA takes place in the viable skin at higher EN application. Further permeation studies of EN or NA were then carried out on full-thickness skin or stripped skin with an esterase inhibitor to measure their permeation parameters, such as partition coefficient of EN from the donor solution to the stratum corneum and diffusion coefficients of EN and NA in the stratum corneum and the viable epidermis and dermis. Separately, enzymatic parameters (Michaelis constant K(m) and maximum metabolism rate V(max)) were obtained from the production rate of NA from different concentrations of EN in the skin homogenate. The obtained permeation and enzymatic parameters were then introduced to differential equations showing Fick's second law of diffusion in the stratum corneum and the law with Michaelis-Menten metabolism in the viable epidermis and dermis. The calculated steady-state fluxes of EN and NA by the equations were very close to the obtained data. We then measured the esterase distribution in skin microphotographically using fluorescein-5-isothiocyanate diacetate. A higher enzyme concentration was observed in the epidermal cells and near hair follicles than in the dermis. Simulation studies using the even and the partial enzyme distribution models suggested that no significant difference between the models was observed in the skin permeations of EN and NA, whereas concentration-distance profiles of EN and NA were very different. This finding suggests that the total amount of enzyme in skin which converts EN to NA is a determinant of the metabolic rate of EN in skin. The present approach is a useful tool for analyzing simultaneous transport and metabolism of many drugs, especially those showing Michaelis-Menten type-metabolic saturation in skin.

Administration, Cutaneous↗

PubMed1999

Tissue factor and tissue factor pathway inhibitor levels during and after cardiopulmonary resuscitation.

Disseminated intravascular coagulation frequently occurs after global ischemia and reperfusion due to cardiac arrest. The present study was performed to demonstrate the role of tissue factor for coagulation pathway activation, as well as to investigate the precise time course of tissue factor pathway inhibitor (TFPI) during and after cardiopulmonary resuscitation (CPR). Thirty-two of out-of-hospital cardiac arrest patients were classified into two groups, those who achieved return of spontaneous circulation (ROSC) (n=13) and those without ROSC (n=19). Ten normal healthy volunteers served as control subjects. Serial levels of tissue factor and TFPI were measured during and after cardiac arrest and CPR. In patients with ROSC, cardiac arrest and CPR led to persistent increases in the levels of tissue factor that peaked 6 hours after arrival at the Emergency Department. Tissue factor levels in patients without ROSC also showed marked elevations compared to those of the control subjects. In both groups, the levels of TFPI were significantly lower than those in the control subjects. However, we could not find differences in the levels of the two markers between the patients with ROSC and those without ROSC. In conclusion, we demonstrated persistent elevation of the tissue factor levels associated with low TFPI during and after CPR in patients with out-of-hospital cardiac arrest. These results indicate the activation of the extrinsic coagulation pathway without adequate TFPI generation, which may contribute to thrombin activation and fibrin formation after whole-body ischemia and reperfusion.

Adult↗

PubMed1999

A new mode of B12 binding and the direct participation of a potassium ion in enzyme catalysis: X-ray structure of diol dehydratase.

BACKGROUND: Diol dehydratase is an enzyme that catalyzes the adenosylcobalamin (coenzyme B12) dependent conversion of 1,2-diols to the corresponding aldehydes. The reaction initiated by homolytic cleavage of the cobalt-carbon bond of the coenzyme proceeds by a radical mechanism. The enzyme is an alpha2beta2gamma2 heterooligomer and has an absolute requirement for a potassium ion for catalytic activity. The crystal structure analysis of a diol dehydratase-cyanocobalamin complex was carried out in order to help understand the mechanism of action of this enzyme. RESULTS: The three-dimensional structure of diol dehydratase in complex with cyanocobalamin was determined at 2.2 A resolution. The enzyme exists as a dimer of heterotrimers (alphabetagamma)2. The cobalamin molecule is bound between the alpha and beta subunits in the 'base-on' mode, that is, 5,6-dimethylbenzimidazole of the nucleotide moiety coordinates to the cobalt atom in the lower axial position. The alpha subunit includes a (beta/alpha)8 barrel. The substrate, 1,2-propanediol, and an essential potassium ion are deeply buried inside the barrel. The two hydroxyl groups of the substrate coordinate directly to the potassium ion. CONCLUSIONS: This is the first crystallographic indication of the 'base-on' mode of cobalamin binding. An unusually long cobalt-base bond seems to favor homolytic cleavage of the cobalt-carbon bond and therefore to favor radical enzyme catalysis. Reactive radical intermediates can be protected from side reactions by spatial isolation inside the barrel. On the basis of unique direct interactions between the potassium ion and the two hydroxyl groups of the substrate, direct participation of a potassium ion in enzyme catalysis is strongly suggested.

Amino Acid Sequence↗

PubMed1999

Screening of cationic compounds as an absorption enhancer for nasal drug delivery.

Several cationic compounds were screened as potential nasal absorption enhancers to increase intranasal absorption of a model drug, fluorescein isothiocyanate labeled dextran (MW 4.4 kDa, FD-4), without nasal membrane damage in rats. Their effects were compared with those of classical enhancers. Various cationic compounds (poly-L-arginines with different molecular weights (MW 8.9, 45.5 and 92.0 kDa, poly-L-Arg (10), (50) and (100), respectively), L-arginine (L-Arg), L-lysine (L-Lys), and cetylpyridinium chloride (CPCL) were evaluated. Of the cationic compounds, poly-L-Arg and CPCL greatly enhanced the intranasal absorption of FD-4, as did chitosan, a cationic polysaccharide which has been reported to show a great effect on the transnasal delivery of peptide and protein drugs. The enhancing intensity by poly-L-Arg was dependent on its molecular weight. Rank order of the enhancing ratio, calculated from the AUC ratio for the enhancer treatment against the untreatment, was 0.5% poly-L-Arg (100) congruent with0.5% sodium dodecylsulfate congruent with0.5% CPCL?0.5% poly-L-Arg (50)?0.5% sodium deoxycholate congruent with0.5% sodium taurodihydrofusidate?0.5% polyoxyethylene-9-lauryl ether congruent with0.5% lysophosphatidylcholine?0.5% chitosan congruent with0.5% poly-L-Arg (10)>/=10% L-Arg congruent with10% L-Lys?0.5% sodium glycocholate congruent with0.5% sodium taurocholate congruent with0.5% EDTA. Only the poly-L-Args represented almost the same degree of hemolysis of cationic compounds compared with pH 7.0 phosphate buffered saline in the rat erythrocyte lysis experiment. The enhancing ratio by classical enhancers correlated with leaching of protein, phospholipids and LDH from isolated rabbit nasal mucosa. CPCL also fell on the regression lines between the enhancing ratio and their degree of leaching from classical enhancers. In contrast, the enhancing intensities by poly-L-Arg (10), (50) and (100) were greatly shifted from the regression line: the amount of leaching was markedly low in spite of a great enhancement of FD-4 absorption. These findings suggest that of the assessed enhancers only the poly-L-Args enhance the transnasal delivery of high molecular substances without severe damage to the nasal mucosal membrane. Poly-L-Arg is therefore a promising candidate having a good balance between enhancing activity and safety for nasal peptide and protein delivery.

Absorption↗

PubMed1999

Differential involvement of the CD95 (Fas/APO-1) receptor/ligand system on apoptosis induced by the wild-type p53 gene transfer in human cancer cells.

The CD95 (Fas/APO-1) system regulates a number of physiological and pathological processes of cell death. The ligand for CD95 induces apoptosis in sensitive target cells by interacting with a transmembrane cell surface CD95 receptor. We previously reported that the recombinant adenovirus-mediated transfer of the wild-type p53 gene caused apoptotic cell death in a variety of human cancer cells. To better understand the mechanism responsible for this cell death signaling, we have investigated the potential involvement of the CD95 receptor/ligand system in p53-mediated apoptosis. The transient expression of the wild-type p53 gene upregulated the CD95 ligand mRNA as well as protein expression in H1299 human lung cancer cells deficient for p53 and in DLD-1 and SW620 human colon cancer cells with mutated p53, all of which constitutively expressed CD95 receptor as shown by a flow cytometric analysis, and induced rapid apoptotic cell death as early as 24 h after gene transfer. However, the sensitivity to the cytolytic effect of agonistic anti-CD95 antibody (CH11) varied among these cell lines: CH11 induced apoptosis in H1299 cells, but not in DLD-1 and SW620 cells despite their abundant CD95 receptor expression, suggesting that the CD95 receptors on DLD-1 and SW620 cells might be inactivated. In addition, an antagonistic anti-CD95 ligand antibody (4H9) that interfered with the CD95-receptor-ligand interaction partially reduced the apoptosis induced by the wild-type p53 gene transfer in H1299 cells, whereas apoptosis of DLD-1 and SW620 cells occurred in the presence of 4H9. Taken together, these findings led us to conclude that the CD95 receptor/ligand system is differentially involved in p53-mediated apoptosis, suggesting that the restoration of the wild-type p53 function may mediate apoptosis through CD95 receptor/ligand interactions as well as an alternative pathway.

Adenocarcinoma↗