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Biomedical subjects

K Uchida

Publications and source records attributed to K Uchida.

At least 1,423 records · Page 79Linked to original sources
PubMed1983

Diffusion coefficients of CO2 molecule and bicarbonate ion in hemoglobin solution measured by fluorescence technique.

The diffusion process of CO2 within a thin layer of hemoglobin (Hb) solution was followed by pH-sensitive fluorescence of 4-methylumbelliferone. In the presence of sufficient carbonic anhydrase in the layer, the pH change was accelerated and determined only by the diffusion. The diffusion rate was reduced as the Hb concentration was increased. The pH rise observed in the CO2 diffusion out of the layer was slower than the pH fall caused by inward diffusion. However, the outward diffusion rate was faster than the inward diffusion rate in contrast to the pH change. The diffusion coefficients of molecular CO2 and bicarbonate ion were separately determined from the simulated and experimental PCO2-time curves by utilizing the non-linearity of the CO2 dissociation curve. The simulated curve was obtained from a numerical solution of the differential equation for diffusion by using the measured CO2 dissociation curve. The diffusion coefficient of CO2 was assumed to decrease exponentially with increasing Hb concentration. The diffusion coefficient of HCO3- was found to be reduced hyperbolically as the Hb concentration was increased. The diffusion coefficients of CO2 and HCO3- of 100% hemolysate were 0.34 X 10(-5) and 0.14 X 10(-5) cm2/sec, respectively.

Adult↗
PubMed1983

Rate of CO2 diffusion in the human red blood cell measured with pH-sensitive fluorescence.

The diffusion rate of CO2, into and out of the red cell, was measured by using a stopped flow method with pH-sensitive fluorescence of 4-methylumbelliferone. A red cell suspension of 15% hematocrit with the PCO2 of 8 Torr (or 65 Torr) was mixed with the same amount of saline solution having 65 Torr (or 8 Torr). Carbonic anhydrase was added to the external solution at a concentration of 20 mg/100 ml in order to accelerate the hydration and dehydration reactions, so that the PCO2 change in the fluid could be observed instantaneously through pH. In the inward diffusion PCO2 showed a large change, suggesting a lack of HCO3- shift across the red cell membrane. In the outward diffusion, however, the PCO2 change was smaller, suggesting that H+ ions produced in the external solution by CO2 hydration were rapidly buffered by the red cell. The half-times of the inward and outward diffusions were, on an average, 0.08 and 0.13 sec, respectively. The results of the simulation revealed that the above difference in half-times was attributed to the difference in slope between the two dissociation curves with and without the HCO3- shift. The diffusion rate was almost constant and remained independent of the direction of CO2 flux. That is, at a low pH range the permeation of H+ ions across the red cell membrane was much faster than the diffusion rate of CO2.

Carbon Dioxide↗
PubMed1983

Isolation and partial characterization of a cerulenin-sensitive mutant of Pseudomonas aeruginosa.

Sensitivity of Pseudomonas aeruginosa to cerulenin was first tested. The result indicated that this bacterium is resistant to cerulenin. Cerulenin-sensitive mutants were isolated from P. aeruginosa PML 1552 by 1-methyl-3-nitro-1-nitrosoguanidine treatment and following carbenicillin plus D-cycloserine screening. Isolated mutants were designated CSM-1 to CSM-19, and some characters of CSM-19, which showed rapid growth almost as well as parent strain in the medium without cerulenin, were examined. The cell growth of CSM-19 was greatly inhibited by 50 micrograms/ml of cerulenin, but when the mixture of cellular fatty acids or both cis-vaccenic acid and palmitic acid were added to the medium, the growth was partially recovered. Incorporation of radioactivity into fatty acids from [1-14C]acetate was lowered by cerulenin. Those results mean that the fatty acid synthesis of CSM-19 was decreased by cerulenin. Although cellular fatty acid composition and amount were not notably different between CSM-19 and PML 1552, CSM-19 had less phosphatidylethanolamine, and more phosphatidylglycerol and cardiolipin than PML 1552. CSM-19 was also supersensitive to several other antibiotics, especially to carbenicillin and tetracycline, when compared with PML 1552, although both strains showed identical sensitivity to D-cycloserine, polymyxin B, and chloramphenicol.

Anti-Bacterial Agents↗
PubMed1983

[Pharmacological characterization of the adrenoceptors in the muscularis mucosae of the guinea-pig esophagus].

Pharmacological characteristics of the post-junctional adrenoceptors in the muscularis mucosae of the guinea-pig esophagus were examined in vitro. In the presence of propranolol (3 microM), all catecholamines, phenylephrine and methoxamine produced a weak contraction of the isolated muscularis mucosae. The order of potency of the contractile response was adrenaline greater than noradrenaline greater than methoxamine greater than phenylephrine and much weaker isoproterenol, dopamine and clonidine. The contractile responses to noradrenaline (10 microM) and adrenaline (10 microM) were markedly inhibited by phentolamine (3 microM), prazosin (3 microM), indomethacin (1 microM), aspirin (100 microM) and polyphloretin (30 microM), and slightly by yohimbine (3 microM). On the other hand, all catecholamines and terbutaline produced relaxation of the isolated muscularis mucosae which was maximally contracted with carbachol (3 microM) in the presence of phentolamine (10 microM), in a concentration-dependent manner. The order of potency of the inhibitory response was isoproterenol greater than noradrenaline greater than adrenaline and much weaker terbutaline and dopamine. The inhibitory responses to catecholamines were competitively antagonized by three beta blockers, being in the following order of potency as estimated by their pA2 values: propranolol greater than atenolol much greater than butoxamine. The pretreatment of the tissue with indomethacin (1 microM) did not modify the inhibitory responses to catecholamines. These results suggest that the guinea-pig esophageal muscularis mucosae has excitatory alpha 1 adrenoceptors and inhibitory beta 1 adrenoceptors, and the alpha 1, but not beta 1, adrenoceptors may link with the endogenous arachidonic acid cascade.

Adrenergic alpha-Antagonists↗
PubMed1983

Purification of porcine pancreatic kallikrein using various affinity chromatographies and intestinal absorption of the purified kallikrein.

For the simple purification of porcine pancreas kallikrein, various affinity chromatographies using L-prolyl-L-phenylalanyl-L-arginine (Pro-Phe-Arg-OH), tosyl-L-arginine (Tos-Arg-OH) and acetyl-L-phenylalanyl-L-arginine (Ac-Phe-Arg-OH) as ligands were examined. The purification was performed as follows using the extract from acetone powder of porcine pancreas as starting material; ammonium sulfate fractionation (30-80%), affinity chromatography (repeated) and gel filtration on Sephadex G-75, respectively. With these purification techniques, porcine pancreas kallikrein was purified about 2000-fold, respectively. From the results, these affinity chromatographies were considered to be effective for the purification of porcine pancreas kallikrein. Intestinal absorption of the purified kallikrein was also investigated using a rabbit. After the administration of the purified kallikrein into the intestinal tract, peripheral blood was taken from the ear vein and the plasma was assayed for Pro-Phe-Arg-7-amino-4-methylcoumarinamide hydrolytic activity. The concentration of the kallikrein in the blood was maximal at 3 hr after the administration and the absorption at this time amounted to about 0.07%.

Animals↗
PubMed1983

[Clinical effects of ceftizoxime and latamoxef on infections in acute leukemia].

Ceftizoxime (CZX) and latamoxef (LMOX), new synthetic cephems, are stable against various types of beta-lactamase and highly active against Gram-negative rods, such as H. influenzae, Serratia, Enterobacter and indole (+) Proteus. In this study, we evaluated clinical effects of CZX and LMOX in the clinical management of infections in acute leukemia. Sixteen episodes of infections were treated with CZX or LMOX. Four causative organisms, P. aeruginosa, S. faecalis, K. pneumoniae and A. faecalis, were identified in 2 episodes of infections. Clinical effects were recognized at 75% in 8 episodes treated with CZX and at 71% in 7 episodes treated with LMOX, respectively. The transient evaluation of GOT, GPT and Al-P, recognized in several cases. In conclusion, the clinical effects of CZX and LMOX are promised in clinical management of infections in acute leukemia.

Acute Disease↗
PubMed1983

[THP-adriamycin in head and neck tumor].

Primary effects and side-effects of a new anthracycline antineoplastic agent, THP-adriamycin (THP-ADM), were examined in 20 patients with malignant head and neck tumors. According to a classification by tumor sites, there were 6 cases of oropharynx, 6 of nose and sinuses, 3 of tongue, 2 of floor of mouth, 2 of neck and 1 of external auditory meatus. According to the tissue classification, there were 11 cases of squamous cell ca., 6 cases of malignant lymphoma, each one case of anaplastic ca., carcino sarcoma and adeno cystic ca. There were 16 previously untreated cases and 4 pretreated cases. Twelve cases received THP-ADM by intraarterial injection and 8 cases by the same dose. 10 to 20 mg/body 3 times a week, in a total of 40 to 100 mg. 2 CR, 5 PR, 3 MR and 4 NC in 14 cases with carcinoma, and 2 CR, 3 PR and 1 MR in 6 cases with malignant lymphoma were obtained. Among 12 cases receiving intraarterial injection, 3 CR and 5 PR were obtained. The decrease of WBC counts below 3000/mm3 after THP-ADM administration was observed in 9 cases. Side effect of THP-ADM appeared to be less severe than that of Adriamycin.

Adolescent↗
PubMed1983

[Clinical study of urinary cytology: with special reference to bladder cancer].

During the last 66 months, 482 urinary cytologic examinations were performed on 160 inpatients suspected of having genitourinary cancer at our University Hospital. Cytologic diagnosis was done according to the Papanicolaou's classification. The cytologic findings were compared by size, shape, numbers of the tumor and the histologic findings. The positive rate (classes IV and V) was 56.7% (90 patients) in bladder cancer, 22.2% (18 patients) in prostatic cancer, 13.3% (15 patients) in renal cancer and 62.5% (8 patients) in renal pelvic or ureteral cancer. There was no false positive case for benign disease. The positive rate of cytologic examinations for stage A bladder cancer was statistically lower than that for stage B, C and D cancers. There were no statistically significant differences among the stage B, C and D groups. The positive rate in the low grade (grade I and II) bladder cancer was statistically lower than that of high grade (grade III and IV) cancer. In the small tumor less than thumbtip -sized, cytological diagnosis was positive in 40.0%, while in the large tumor larger than this size, the positive rate was 73.3%. The difference between these two groups was statistically significant. The positive rate in the non-recurrent cases of the bladder cancer was 64.5%, while that in the recurrent cancer cases was 39.3%. The difference between these two groups was statistically significant. The positive rate of urinary cytology did not correspond to the shape or number of tumors. It is desirable to perform cytology more than 3 times on the same patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

[Postoperative complications and followup in cystectomy].

Clinical studies on postoperative complications and prognosis were done on 27 patients who had undergone cystectomy at our hospital. Thirty one postoperative complications were seen in 16 patients. Early complications which developed within 3 months of operation were more frequent (25 cases). They included pyelonephritis (5 cases), wound infection (4 cases), pulmonary complications (2 cases), cardiovascular complications (2 cases), ileus (2 cases) and delayed ambulance (2 cases) in decreasing order of frequency. Complications related to urinary diversion were observed in 4 out of 6 late complications. Reoperation secondary to surgical complications were done in 6 cases. Four of the 6 reoperations were related to gastrointestinal complications, all of which would be fatal if left untreated. Postoperative followup period ranged from 3 weeks to 49 months with a mean period of 12.8 months. The present status of the patients is as follows: 16 patients alive, 10 patients dead and 1 patient lost to followup. So far we cannot draw a definite conclusion regarding the relationship between surgery and the prognosis of the patients because the followup period is too short in many patients. In our experience: 1) The fewest cancer deaths occurred in patients who had undergone radical surgery; 2) the largest percentage of living patients was seen in the group of patients who had undergone radical cystectomy; and, 3) almost all patients with low stage tumors are living more than 6 months after operation.

Adult↗
PubMed1982

Isolation of an unusual 'lipid A' type glycolipid from Pseudomonas paucimobilis.

A new glycolipid was isolated from defatted cells of Pseudomonas paucimobilis IAM 12576, and called 'bound lipid'. The 'bound lipid' could not be extracted by hot phenol extraction, but could be extracted with hot chloroform/methanol after hydrolysis with 5% trichloroacetic acid. The 'bound lipid' was purified by thin-layer chromatography on silica gel plates using the solvent mixture CHCl3/CH3OH/CH3COOOH/ H2O (25:15:4:2, v/v). It consisted of glucosamine, 2-hydroxy myristic acid, galactose, mannose and uronic acid with ratios of 1.0:0.75:0.77:0.44:1.5, respectively, and other fatty acids besides 2-hydroxy myristic acid were not detected in the 'bound lipid'. 2-Hydroxy myristic acid was probably bound to glucosamine residues by amide linkage, because mild alkali treatment did not liberate the fatty acid. From these results, we discussed the possibility that the 'bound lipid' was some kind of lipid A of this bacteria.

Amino Acids↗
PubMed1982

A retino-pulvinar projection in the macaque monkey as visualized by the use of anterograde transport of horseradish peroxidase.

A direct retino-pulvinar connection was found in the Japanese monkey (Macaca fuscata) by the anterograde horseradish peroxidase (HRP) method. HRP injected into the vitreous cavity of one eye labeled a few small clusters of optic fiber terminals in the medial border regions of the inferior pulvinar nucleus bilaterally, with a contralateral predominance.

Afferent Pathways↗