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Biomedical subjects

H Uchida

Publications and source records attributed to H Uchida.

At least 37 records · Page 2Linked to original sources
PubMed2001

Experimental small bowel transplantation using newborn intestine in rats: III. Long-term cryopreservation of rat newborn intestine.

BACKGROUND: If long-term organ cryopreservation can be attained, a significant achievement will have been made to address the problem for donor shortage. Fetal intestine has been known to revascularize naturally without vascular anastmosis. The authors have confirmed previously that the newborn intestine also could develop to maturity in the host omentum. Here, the authors examined whether the cryopreserved newborn intestine could revascularize in the syngeneic combination using the 2 different solutions and whether cryopreservation affect their antigenicity in the allogeneic combination. METHODS: Inbred rat strains of LEW (MHC haplotype; RT1(l)) and BN (RT1(n)) were used. LEW newborn intestinal grafts were stored in RPMI-1640 or University of Wisconsin solution with 10% DEMSO (n = 10 in each group). The grafts were placed into a cold (4 degrees C) preservation solution for 30 minutes and then placed into a freezing chamber and cooled to -80 degrees C at -1 degrees C/min after 12 hours quenched to -180 degrees C in liquid nitrogen for longer than 30 days. Then, the cryopreserved grafts under the 2 different solutions were transplanted syngenicaly (LEW to LEW). The cryopreserved BN grafts also were implanted into the LEW omentum pouch. The allotransplantation was received with a 14-day high-dose course of tacrolimus (0.64 mg/kg, intramuscularly). The grafts were evaluated histologically at 4 weeks after transplantation. Fresh newborn intestines implanted in this syngeneic and allogeneic combination were evaluated as each control group. RESULT: In the syngeneic combination, more than 90% of the mature intestine were obtained. There was no significant difference among the different solution and the fresh group. However, in the allogeneic combination, both fresh and cryopreserved grafts were histologically poor. CONCLUSIONS: This is the first report showing that long-term cryopreservation was not harmful for neovascularization of newborn intestine. Long-term cryopreservation did not reduce the antigenicity of the newborn intestine. J Pediatr Surg 36:602-604.

Animals↗
PubMed2001

Experimental small bowel transplantation using a newborn intestine in rats: IV. Effect of cold preservation on graft neovascularization.

BACKGROUND/PURPOSE: University of Wisconsin (UW) solution is one of the most superior organ preservation solutions for liver, kidney, and pancreas; however, it still is controversial for intestinal preservation. Here, the authors studied the efficacy of preservation with 2 kinds of solutions, UW and modified TOM (m-TOM) solutions in our experimental newborn intestinal transplantation model. UW solution was used as a standard intracellular and m-TOM solution as an extracellular preservation solution. Lactated ringer (LR) solution was used as a control. METHODS: Newborn intestine, which were preserved in these solutions for 24 or 48 hours, were transplanted in the subcutaneous spaces of the syngeneic recipients without surgical vascular anastomosis and histologically examined 14 days after grafting. The preserved grafts were evaluated histologically by use of light and electron microscopy just after preservation. The biochemical parameters such as LDH and serotonin also were measured in the supernatants of preservation solutions. RESULTS: Fresh newborn grafts were revascularized successfully at a rate of 80% (16 of 20). After 24 hours of preservation, 65% (13 of 20), 75% (15 of 20), and 85% (17 of 20) of the grafts were observed to be revascularized in LR, m-TOM, and UW solutions, respectively. After 48 hours of preservation, 60% (12 of 20), 80% (16 of 20), and 80% (16 of 20) of the grafts also were revascularized in the respective solutions (no statistic difference among the groups). The cold-preservation did not affect the neovascularization of newborn intestine until 48 hours. Histologic findings of the preserved intestine and biochemical analyses showed that UW and m-TOM solutions kept villous architectures of the preserved grafts, however, might be harmful to enterochromaffin cells. CONCLUSION: Long-time preservation of newborn intestine did not interfere with neovascularization and maturation. J Pediatr Surg 36:1805-1810.

Animals↗
PubMed2001

Real time visualization of 13N-translocation in rice under different environmental conditions using positron emitting Ttacer imaging system.

The ammonium ion is an indispensable nitrogen source for crops, especially paddy rice (Oryza sativa L. cv Nipponbare). Until now, it has been impossible to measure ammonium uptake and nitrogen movement in plants in real time. Using the new technologies of PETIS (positron emitting tracer imaging system) and PMPS (positron multi-probe system), we were able to visualize the real time translocation of nitrogen and water in rice plants. We used positron-emitting 13N-labeled ammonium (13NH4+) and 15O-water to monitor the movement. In plants cultured under normal conditions, 13NH4+ supplied to roots was taken up, and a 13N signal was detected at the discrimination center, the basal part of the shoots, within 2 minutes. This rapid translocation of (13)N was almost completely inhibited by a glutamine synthetase inhibitor, methionine sulfoximine. In general, nitrogen deficiency enhanced 13N translocation to the discrimination center. In the dark, 13N translocation to the discrimination center was suppressed to 40% of control levels, whereas 15O-water flow from the root to the discrimination center stopped completely in the dark. In abscisic acid-treated rice, 13N translocation to the discrimination center was doubled, whereas translocation to leaves decreased to 40% of control levels. Pretreatment with NO3- for 36 hours increased 13N translocation from the roots to the discrimination center to 5 times of control levels. These results suggest that ammonium assimilation (from the roots to the discrimination center) depends passively on water flow, but actively on NH4+-transporter(s) or glutamine synthetase(s).

Biological Transport↗
PubMed2001

Deletion mutants of human deoxycytidine kinase mRNA in cells resistant to antitumor cytosine nucleosides.

We studied mutational events in deoxycytidine (dCyd) kinase mRNA expression, focusing on aberrant dCyd kinase mRNA, which has been frequently observed in established cell lines resistant to antitumor dCyd nucleoside analogues such as 1-beta-D-arabinofuranosyl cytosine (Ara-C), gemcitabine (dFdC) and 2'-C-cyano-2'-deoxy-1-beta-D-arabinofuranosylcytosine (CNDAC). We describe here the expression of aberrant dCyd kinase mRNAs identified as splicing mutants. These mutants included deletions of the fifth exon in CNDAC-resistant cells (originating from HT-1080 cells), of the third exon in Ara-C-resistant cells (originating from SK-MEL-28 cells) and of the fourth exon in 2'-deoxy-2'-methylidenecytidine (DMDC)-resistant cells (originating from SK-MEL-28 cells). Various nucleoside-resistant cells originating from the same parental HT-1080 cells were established. The resulting cells expressed the same mRNA with deletion of the fifth exon, and the location of splicing was independent of the type of nucleosides used for the establishment of resistant cells. The deletion of the fifth exon in dCyd kinase seems to be a target for acquisition of resistance to antitumor cytosine nucleosides. However, distinct mutations in the dCyd kinase gene seem to be associated with acquisition of resistance to different antitumor cytosine nucleosides.

Antimetabolites, Antineoplastic↗
PubMed2001

Stent-Graft treatment of dissecting aneurysm in association with aortic intramural hematoma: when should the procedure be performed?

PURPOSE: To report 2 cases of stent-graft implantation for localized dissecting aneurysm during the conservative treatment of aortic intramural hematoma. CASE REPORTS: One patient underwent stent-graft implantation for 2 localized dissecting aneurysms about 23 months after symptom onset. Computed tomography (CT) 1 year after the procedure demonstrated aneurysm shrinkage. In the other patient, a localized dissecting aneurysm was treated about 3 months after symptom onset, even though the intramural hematoma had not resolved. CT scanning 3 months after the procedure demonstrated aneurysm shrinkage, but also revealed poor attachment of the distal stent-graft to the aortic wall due to subsequent resolution of the hematoma. CONCLUSIONS: Endograft implantation for treatment of localized dissecting aneurysm associated with aortic intramural hematoma should probably not be performed before the hematoma has completely resolved.

Aortic Dissection↗
PubMed2001

[The occurrence of Churg-Strauss syndrome in two patients with remitted asthma].

We report two patients with Churg-Strauss syndrome (CSS) which occurred on the remission stage of bronchial asthma. Case 1 of a 64-year-old woman suffered from asthma in June, 1997, and got relief with treatment. In February, 1998, dysesthesia, pain and severe muscle weakness occurred in the extremities and erythematous rashes appeared on the extremities and back. She was transferred to our hospital on March 3. Peripheral blood eosinophilia was observed and a diagnosis of CSS was made. Eosinophilic tissue infiltration and vasculitis was found in the skin biopsy specimen. She was treated with prednisolone (60 mg/day) with moderate improvement. But the dysesthesia in the extremities, bilateral foot drop and the weakness of the left hand grasping power continued. Case 2 of a 62-year-old woman suffered from asthma in 1995, which improved by treatment. In March 1998, dysesthesia and pain in the lower extremities occurred and progressed. Erythematous rashes appeared on the feet and she was admitted to our hospital in May. Peripheral blood eosinophilia and eosinophilic tissue infiltration in the skin biopsy specimen were observed and a diagnosis of CSS was made. The treatment with prednisolone (60 mg/day) improved the pain but the dysesthesia continued. It is important to know the occurrence of CSS on the remission stage of bronchial asthma.

Asthma↗
PubMed2001

Rapid N transport to pods and seeds in N-deficient soybean plants.

Non-nodulated soybean (Glycine max (L.) Merr.) plants were cultivated hydroponically under N-sufficient (5 mM NaNO(3)) or N-deficient (0.5 mM NaNO(3)) conditions. (13)N- or (15)N- labelled nitrate was fed to the cut end of the stems, and the accumulation of nitrate-derived N in the pods, nodes and stems was compared. Real-time images of (13)N distribution in stems, petioles and pods were obtained using a Positron Emitting Tracer Imaging System for a period of 40 min. The results indicated that the radioactivity in the pods of N-deficient plants was about 10 times higher than that of N-sufficient plants, although radioactivity in the stems and nodes of N-deficient versus N-sufficient plants was not different. A similar result was obtained by supplying (15)NO(3) to cut soybean shoots for 1 h. The fact that the N translocation into the pods from NO(3) fed to the stem base was much faster in N-deficient plants may be due to the strong sink activity of the pods in N-deficient plants. Alternatively, the redistribution of N from the leaves to the pods via the phloem may be accelerated in N-deficient plants. The temporal accumulation of (13)NO(3) in nodes was suggested in both N-sufficient and N-deficient plants. In one (13)NO(3) pulse-chase experiment, radioactivity in the stem declined rapidly after transferring the shoot from the (13)NO(3) solution to non-labelled NO(3); in contrast, the radioactivity in the node declined minimally during the same time period.

Amino Acids↗
PubMed2001

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (1)--A study on oral administration prior to and in the early stages of pregnancy in rats].

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to rats at doses of 100, 300 or 1000 mg potency/kg/day prior to and in the early stage of pregnancy to assess its adverse effects on parental reproductive ability and embryo-fetal development. Loose and/or reddish brown feces were observed in both males and females of all the S-1090 dosing groups, and abdominal distention was also observed in males throughout the dosing period. No drug-related deaths occurred in either males or females. In males, body weight and food consumption were increased at a dose of 1000 mg potency/kg/day throughout the dosing period. In females, body weight gain was restrained during late pregnancy, and food consumption was decreased transiently following the initiation of dosing, and then remained high on the day before parturition in all the S-1090 dosing groups. Necropsy of male and female rats revealed an increase in the cecum weight. The reproductive ability of males and females was normal in all the S-1090 dosing groups. No effects of S-1090 were observed in the implantation ratio, embryo-fetal viability, fetal body weight, and incidence of external, skeletal and visceral anomalies. Based on these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for parental general toxicity, 1000 mg potency/kg/day for reproductive toxicity, and 1000 mg potency/kg/day for developmental toxicity in embryo-fetuses under the conditions of the present study.

Administration, Oral↗
PubMed2001

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (2)--A study on oral administration during the period of organogenesis in rats].

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to female rats at doses of 100, 300 or 1000 mg potency/kg/day from Days 7 to 17 of pregnancy to assess its effects on dams and on development of the embryo-fetuses and offspring. Loose or reddish-brown feces were observed in dams of all the S-1090 dosing groups. Body weight gain was increased from the early stage of administration to the end of pregnancy, food consumption was transiently decreased at the early stage of administration, and water consumption was increased from the middle to the end of pregnancy in all the S-1090 dosing groups. However, no effects on pregnancy, parturition and lactation were observed. Necrospy revealed an increased cecum weight in pregnant and lactating dams of all the S-1090 dosing groups. No effects of S-1090 were observed in viability, growth, incidences of external, skeletal and visceral anomalies, and degree of ossification in F1 fetuses. No effects of S-1090 were observed in such parameters as viability, incidence of external and skeletal anomalies, physical development, sensory functions/reflexes, behavior and reproductive function in F1 offspring. No adverse effects were observed in F2 offspring. On the basis of these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for maternal general toxicity, 1000 mg potency/kg/day for maternal reproductive toxicity and the developmental toxicity in the embryo-fetuses and offspring under the conditions of the present study.

Abnormalities, Drug-Induced↗
PubMed2001

[Reproductive and developmental toxicity studies of S-1090, cefmatilen hydrochloride hydrate (4)--A study on oral administration during the perinatal and lactation periods in rats].

Cefmatilen hydrochloride hydrate (S-1090) was administered daily by gavage to female rats at doses of 100, 300 or 1000 mg potency/kg/day from Day 17 of pregnancy to Day 20 of lactation to assess its effects on pregnant/lactating females and on development of the offspring. In dams, loose feces/reddish brown feces, increased cecum weight, decreased weights of the heart, spleen and submaxillary gland in all the S-1090 dosing groups and a decreased weight of the thymus in the 1000 mg potency/kg dosing group were observed. However, no effects on parturition and lactation were observed in any of the dosing groups. In F1 offspring, although increased cecum weight was found at weaning in all the S-1090 dosing groups, no abnormalities in viability, physical development, sensory functions/reflexes, behavior and reproductive function were observed. No adverse effects were observed in F2 fetuses and offspring. On the basis of these results, the no observed adverse effect levels of S-1090 are estimated to be less than 100 mg potency/kg/day for maternal general toxicity, and 1000 mg potency/kg/day for maternal reproductive toxicity and for developmental and reproductive toxicity in offspring under the conditions of the present study.

Administration, Oral↗
PubMed2001

[Radiological assessment of the structural relationship between the trachea and the innominate artery in physically disabled and scoliotic children].

Studies were made on the physically disabled and scoliotic children who underwent tracheostomy. The purpose was to clarify factors that might lead to the tracheo-innominate artery fistula, by use of three-dimensional helical CT (3 DCT). In a case of right scoliosis, the tracheo-innominate artery fistula may be caused by the left-ward displacement of the trachea from the vertebra, having the innominate artery ride over the trachea and compressing it. In a case of the physically disabled and scoliotic children, there may be more compression on the trachea by the innominate artery along with the worsening scoliosis. Therefore, we consider it necessary to examine the structural relationship between the trachea, the vertebra, and the innominate artery periodically by 3 DCT.

Adolescent↗
PubMed2001

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). I. Susceptibility distribution].

The bacterial strains isolated from patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the susceptibilities of them to many kinds of antimicrobial agents were investigated. The number of them were 499 strains. The breakdown of these strains was Gram-positive bacteria as 31.3% and Gram-negative bacteria as 68.7%. Susceptibilities of these bacteria to antimicrobial agents were as follows; vancomycin (VCM), ampicillin (ABPC) and imipenem (IPM) showed strong activities against Enterococcus faecalis. The increase of low-susceptible strains which was noticed in the former year showed a slight recovery in this year. VCM showed a strong activity against MRSA preventing growth of all strains with 1 microgram/ml. In addition, the activity of arbekacin (ABK) was also strong with the MIC90 of 2 micrograms/ml against MRSA. However, MSSA and MRSA showing low susceptibilities were detected in one strain each (MIC: 16 micrograms/ml and 32 micrograms/ml, respectively). Carbapenems showed high activities against Citrobacter freundii and Escherichia coli. Meropenem (MEPM) prevented growth of all strains within 0.125 microgram/ml. Quinolone resistant E. coli decreased in this year compared with those in the last year, that percentage was less than 5%. Almost all drugs showed strong activities against Klebsiella pneumoniae and Proteus mirabilis. MEPM and carumonam (CRMN) prevented growth of all strains within 0.125 microgram/ml. On the other hand, one strain of K. pneumoniae showing resistance to cefaclor (CCL) and one strain of P. mirabilis showing low susceptibility to most of cephems were detected. Against Pseudomonas aeruginosa, almost drugs were not so active. The MIC90s of carbapenems were 8 micrograms/ml and those of all other drugs were more than 16 micrograms/ml.

Anti-Bacterial Agents↗
PubMed2001

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). II. Background of patients].

Five-hundred forty four bacterial strains isolated from 412 patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the clinical background of patients were investigated such as sex, age and type of infections, infections and kind of bacteria, frequency of isolation of bacteria by age and infections, bacteria and infections by timing of administration of antibiotics, and bacteria and infections by surgical procedures. About the relationship between age and sex of patients and type of infections, the number of male patients aged less than 50 years was few, and complicated UTIs without indwelling catheter was the most frequent. In females, the number of patients aged less than 20 years was few. Complicated UTIs without indwelling catheter was the most frequent among female patients aged between 40 to 59 years, in other age groups, uncomplicated UTIs was most frequent. As for type of infections and kind of bacteria, Escherichia coli decreased when the infections became complicated, and Pseudomonas aeruginosa and Enterococcus faecalis increased when the infection became complicated. Considering this result by age of patients, isolation frequency of E. coli was gradually decreased with aging in patients aged more than 20 years with uncomplicated UTIs or complicated UTIs without indwelling catheter. The isolation frequencies of E. faecalis and Staphylococcus aureus were gradually increased with aging in complicated UTIs without indwelling catheter. In patients with complicated UTIs with indwelling catheter, there was no difference between age group, and P. aeruginosa and E. faecalis were frequently isolated. As for type of causative organisms in UTIs before and after the administration of antibiotics, the isolation of bacteria was remarkably decreased after administration in patients with uncomplicated UTIs and complicated UTIs without indwelling catheter. E. coli decreased after administration of antibiotics, and P. aeruginosa and E. faecalis increased after administration in patients with all infections. As for type of causative organisms in UTIs and surgical procedures, E. coli were more frequently isolated in patients with uncomplicated UTIs when surgical procedures were experienced. Also, Klebsiella spp. and E. faecalis were more frequently isolated in patients with surgical procedures. However, in complicated UTIs, type of causative organisms had no relationship with surgical procedures.

Adolescent↗
PubMed2001

[Comparative studies on activities of antimicrobial agents against causative organisms isolated from patients with urinary tract infections (1999). III. Secular changes in susceptibility].

The bacteria (Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella spp. and Pseudomonas aeruginosa) isolated from patients diagnosed as having urinary tract infections (UTIs) in 9 institutions in Japan were supplied between the period of August 1999 to July 2000. Then, the susceptibilities of these bacteria to various antimicrobial agents were examined and the results were compared with those obtained between 1991 and 1998. Comparison was made by classifying strains isolated from patients into those with uncomplicated UTIs and those with complicated UTIs (including with or without indwelling catheter). About E. faecalis, increase of low sensitive strains noted in the former year showed a decreasing tendency, however, one strain each with MIC of 4 micrograms/ml to vancomycin (VCM) was detected in patients with both uncomplicated and complicated UTIs. As for S. aureus, many sensitive strains to cephems, imipenem (IPM) and VCM were noted, and each MIC50 was better than that in the former years. S. aureus strains showing low susceptibility to arbekacin (ABK) were detected in patients with complicated UTIs in this year as well as in the former year, and one strain each with MIC of 16 micrograms/ml and 32 micrograms/ml was detected. Susceptibilities of E. coli were effective to all drugs except for penicillins and minocycline (MINO). Decrease of low sensitive strains was also noted in all drugs except for quinolones. Each MIC90 of ciprofloxacin (CPFX) and sparfloxacin (SPFX) in patients with complicated UTIs against E. coli was 3 degrees classes lower than that in patients with uncomplicated UTIs. As for Klebsiella pneumoniae, decrease of low sensitive strains to cephems was noted in patients with uncomplicated UTIs in 1998. In 1999, low sensitive strains decreased also in patients with complicated UTIs, and few were detected. Susceptibilities of K. pneumoniae to quinolones were effective as compared with those in the former years with the MIC80s of 0.125 microgram/ml or below without detection of low sensitive strains. One low sensitive strain of K. pneumoniae with MIC of 8 micrograms/ml was detected for gentamicin (GM). Susceptibilities of P. aeruginosa to carbapenems were notable. The MIC90 of meropenem (MEPM) and IPM was 4 micrograms/ml each which was 2 degrees better than that in 1998. Resistant P. aeruginosa strains to other drugs except for monobactams decreased in 1999.

Anti-Bacterial Agents↗
PubMed2001

Chronopharmacology of oral prednisolone in rats.

The chronopharmacology of oral prednisolone (PSL) was studied in rat models. Differences in the dosing-time-dependent toxicity were evaluated at four time points (3, 9, 15 and 21 HALO) in adult male Wistar rats and confirmed in an inbred strain of Lewis rats (MHC haplotype; RTIl) at two time points (9 and 21 HALO). The total body weight and that of the immunologic-related organs were maximally reduced when PSL was repeatedly administered during the late active phase (21 HALO). This chronotoxicity was independent of plasma concentrations of PSL, adrenocorticotropic hormone, and corticosterone. Repeated administration of PSL prolonged cardiac allograft survival in a DA (RTIa) -to-Lewis combination, and there was a tendency to be more effective in the 21 HALO trial. These results suggested that single dose therapy of PSL at the selected point of the day may be less harmful, protecting against allograft rejection.

Administration, Oral↗
PubMed2001

Identification and comparison of residues critical for cell-adhesion activities of two neutrophil CD66 antigens, CEACAM6 and CEACAM8.

CEACAM6 (CD66c) and CEACAM8 (CD66b) are cell-adhesion proteins on neutrophils that belong to the human carcinoembryonic antigen (CEA) family. CEACAM6 reveals homophilic adhesion and heterophilic adhesion to other CEACAM family antigens including CEACAM8, CEACAM1, and CEA, whereas CEACAM8 exhibits only heterophilic adhesion to CEACAM6. Here, we investigated and compared structural requirements for the homophilic adhesion of CEACAM6 and heterophilic adhesion between CEACAM6 and CEACAM8 at the amino acid level by using CHO transfectants expressing their mutant and chimeric proteins. The NH(2)-terminal domain (N-domain) of CEACAM6 expressed on a CHO cell was suggested to bind the N-domain of CEACAM6 or CEACAM8 on the opposing cell. By homologue-scanning mutagenesis, we found that the locations of the sequences critical for the adhesion of CEACAM6 to itself and to CEACAM8 are overlapped and that they are highly similar but not identical to the locations of the residues previously shown to be essential for the binding of CEACAM antigens to Opa proteins of pathogenic NEISSERIAE: Our findings imply that subtle differences in the N-domain sequences determine the specificity of the CEACAM antigens on neutrophils for interaction with the same or different CEACAM antigens and the bacterial proteins.

Amino Acid Sequence↗