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Biomedical subjects

T Kudo

Publications and source records attributed to T Kudo.

At least 487 records · Page 27Linked to original sources
PubMed1990

DNA sequences required for the alkalophily of Bacillus sp. strain C-125 are located close together on its chromosomal DNA.

Two alkali-sensitive mutants of alkalophilic Bacillus sp. strain C-125 were obtained. Mutant 38154 showed defective regulation of internal pH. Plasmids pALK1 and pALK2, containing DNA fragments different from those of the parent strain, were able to recover alkalophily in mutants 18224 and 38154, respectively. DNA analysis suggested that the two fragments overlapped on the chromosomal DNA of strain C-125.

Bacillus↗
PubMed1990

Learning impairment and microtubule-associated protein 2 decrease in gerbils under chronic cerebral hypoperfusion.

A coiled stainless steel wire clip was made that allowed us to chronically reduce cerebral blood flow in Mongolian gerbils. After 6 weeks of reduced cerebral blood flow in 15 experimental gerbils, we evaluated their learning ability and found it to be impaired relative to that in 15 control gerbils. Eight weeks after surgery, regional cerebral blood flow in the parietal cortex measured by the hydrogen clearance method in the experimental gerbils was 73-76% of that in the control gerbils. Light microscopy showed minimal histologic changes in the brains of the experimental gerbils. Concentrations of brain proteins analyzed using sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that among water-soluble brain proteins, the concentrations of cytoskeletal proteins (microtubule-associated protein 2, calspectin, and clathrin) declined in the experimental gerbils. In particular, the concentration of microtubule-associated protein 2 declined significantly. Our findings show that the reduction of cerebral blood flow via carotid stenosis impairs the learning behavior in gerbils, with an associated decrease in the concentration of microtubule-associated protein 2. We believe that Mongolian gerbils with chronically reduced cerebral blood flow are a useful animal model of chronic brain hypoperfusion.

Animals↗
PubMed1990

[Research for development of immunoassay kits for hapten].

Determination of estrogen concentrations in the urine is widely utilized for a variety of purposes, such as the assessing of fetoplacental unit function and ovarian function, and the monitoring of follicle in inducing ovulation in the treatment of infertility. Since hapten antigens such as estrogen have low molecular weight, unlike high molecular substances, they do not form visible agglutination of antigen-antibody reaction, so there has been no other choice but to depend on radioimmunoassay for the determination of estrogen concentrations. However, radioimmunoassay requires special facilities and apparatus and is complicated in procedure, and these drawbacks have prevented the estrogen assay from routine tests in spite of clinical usefulness. As a result of various researches, a new immunochemical principle called competitive agglutination inhibition reaction has been developed for the determination of hapten concentrations, and succeeded in putting this principle to practical use with a fetoplacental unit function test kit (Estrotec slide test) and highly sensitive semi-quantitative analysis kits for urinary estrogen (Hi-estrotec and Hi-estrotec slide).

Estrogens↗
PubMed1990

[Clinical efficacy of recombinant interleukin-2 for renal cell carcinoma and the effect of blood transfusion upon the immune response of these patients].

We studied the efficacy and safety of recombinant interleukin-2 (rIL-2: S-6820) for the treatment of renal cell carcinoma as well as the effect of blood transfusion upon the immune response of these patients. Among 14 cases of renal cell carcinoma treated by i.v. infusion of rIL-2, a partial response (PR) was achieved in one patient, 10 patients had no change, and in 3 had the disease progressed. The overall efficacy rate was 7.1%. However, the rate increased to 12.5% in cases with pulmonary metastases and to 14.3% in cases without any blood transfusion within a year before treatment with rIL-2. No severe side effects were observed, except for central nervous system disturbance in one case. During the rIL-2 therapy, LAK activity was suppressed in the transfused patients. On the other hand, NK activity was augmented in transfused patients to the same degree as in non-transfused cases. No significant changes of lymphocyte count and the subsets of peripheral blood lymphocytes were observed in either group treated with rIL-2. Anemia and radical nephrectomy did not affect the immune response in these patient. Thus, it appeared that blood transfusion altered the immune response in patients treated with rIL-2. However, it could not be concluded that transfusion definitely had an adverse effect on the clinical efficacy of rIL-2 for renal cell carcinoma.

Adult↗
PubMed1990

A new aminothiazolylcephalosporin having 1-carboxyethoxyimino group, ME1228.

Aminothiazolylacetamidocephalosporins having 1-carboxyethoxyimino groups were synthesized and found to have excellent antibacterial activities including anti-pseudomonal activity and low toxicities. Among these cephalosporins, ME1228 having (S)-1-carboxyethoxyimino substituent and being combined with an (N-ethyl-4-pyridinio)thiomethyl group at C-3 showed marked therapeutic effects against systemic infections in mice and was selected as the best candidate for further evaluation.

Animals↗
PubMed1990

Comparison of CD composition produced by chimeric CGTases.

Using 12 chimeric cyclomaltodextrin glucanotransferases (CGTases) constructed from two genes, the CGTase gene from the alkalophilic Bacillus sp. strain No. 38-2 (CGTase 38-2 gene) and the CGTase gene from the alkalophilic Bacillus sp. strain No. 17-1 (CGTase 17-1 gene), we compared the effect of those chimeric enzymes on cyclodextrin (CD) production, especially on the composition of the CDs produced. It was found that the N-terminal and the C-terminal segments were important for CD production. Chimeric enzymes that contained the N-terminal and the C-terminal segments derived from CGTase 38-2 produced large amounts of CD, and especially a higher proportion of alpha-CD than those of other chimeric enzymes.

Bacillus↗
PubMed1990

Extracellular production of human tumor necrosis factor-alpha by Escherichia coli using a chemically-synthesized gene.

A DNA fragment of approximately 490 base pairs encoding human TNF was chemically synthesized and expressed within Escherichia coli cells. Furthermore, extracellular production of human TNF and several N-terminal deletion mutants of TNF was attempted using the excretion vector pEAP8. The TNF mutant with two N-terminal amino acids deleted (N delta 2-TNF) was efficiently excreted into the culture medium by E. coli carrying the plasmid pEXTNF3. In this clone, the signal peptide was correctly processed during the excretion. The E. coli-excreted N delta 2-TNF had higher antitumor activity than wild-type TNF or N delta 2-TNF produced intracellularly by E. coli.

Amino Acid Sequence↗
PubMed1990

[Effect of continuous epidural infusion of morphine on postoperative glucose metabolism].

Plasma growth hormone (GH), insulin, prolactin and blood glucose levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in 16 patients who underwent gastrectomy. Continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia) was given to eight (epidural morphine group) patients. A bolus of epidural morphine was administered through an indwelling thoracic (Th8.9) catheter at 3 hrs prior to the expected end of surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042 mg.hr-1 with the pump during and after anesthesia and surgery with gradually decreasing dose until the third postoperative day. The remaining eight patients (systemic analgesics group) repeatedly received intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma GH levels increased significantly only on the first postoperative day in both groups. Plasma insulin levels increased significantly on the first postoperative day in both groups. Blood glucose levels increased significantly at the end of surgery and during the following three postoperative days in both groups. There are no statistical differences in plasma GH, insulin and blood glucose levels between the two groups. Plasma prolactin concentrations increased significantly at the end of surgery and they were significantly higher in the systemic analgesic group than in the epidural morphine group. They, however, returned to the previous day's levels on the first postoperative day in both groups. Our study suggests that continuous epidural infusion of morphine has no suppressing effect on postoperative changes in plasma GH, insulin, prolactin and blood glucose levels as compared with systemic analgesic regimen.

Adult↗
PubMed1990

[Milk of calcium renal stone treated with endoscopic extraction: a case report].

The patient, an 18-year-old woman, visited a local doctor complaining of right flank pain. Characteristic findings obtained by X-ray examination suggested milk of calcium renal stone in the calyceal diverticulum of the right kidney, she was introduced to our clinic on February 16, 1989. Although examinations on admission showed no urinary tract obstruction or renal function disorders, since she repeatedly suffered from flank pain, we decided to remove the stone percutaneously and widen the mouth of the diverticulum. Conventional percutaneous nephrolithotripsy methods were used to endoscopically remove the stone but we were unable to ascertain the mouth of the calyceal diverticulum. Thus, we removed the nephrostomy tube. The stone was composed to 83% calcium oxalate and 17% calcium phosphate. She was released from the hospital with no particular postoperative complications and at present the flank pain has disappeared. Percutaneous treatments against milk of calcium renal stone are discussed.

Adolescent↗
PubMed1990

Pharmacological and biochemical study on the mechanism of enkephalin production in rat dental pulp.

The production of enkephalin (EK) in the rat dental pulp was studied in pharmacological and biochemical aspects of EK-producing enzyme, EK precursor protein and the regulation of EK production. The EK precursor protein was primarily distributed in the microsomal fraction, and a common precursor protein (Mr about 58,000) was partially purified by Sephadex G-100 chromatography. Since the EK-producing enzyme, however, was mainly localized in the lysosomal fraction, and was found to be a cysteine proteinase, the lysosomal cysteine proteinases, cathepsins H, B and L, were separated by CM Sephadex C-50 ion exchange chromatography, and identified in respects to substrate specificity, pH optimum and inhibitor sensitivity. The EK-producing activity of the cathepsin B was demonstrated using the partially purified EK precursor protein from the pulp tissue as a substrate. The cathepsin B was further purified by Sephadex G-75 gel filtration to a 400-fold purity, and SDS polyacrylamide gel electrophoresis of the enzyme showed a distinct homogeneity (Mr about 23,600). The purified enzyme cleaved BAM-12P, a met-EK-containing peptide from bovine adrenal medulla, to met-EK-Arg6, but did not convert met-EK-Arg6 to met-EK, suggesting an endopeptidase activity of the enzyme. On the other hand, a concentration-dependent activation of the enzyme by bradykinin (BK) and des-Arg9-BK was found to be mediated through B1 receptor in intact pulp tissue. It was also demonstrated that intact structure of lysosomes and Ca++ were necessary for the activation of the enzyme by BK.

Animals↗
PubMed1990

[Mode of hypertrophy in hypertrophic cardiomyopathy based on the external shape of the left ventricle: a two-dimensional echocardiographic study].

To assess the mode of left ventricular hypertrophy in hypertrophic cardiomyopathy (HCM), two-dimensional echocardiography was performed in 15 patients with asymmetric septal hypertrophy and in 13 normal subjects. The long-axis diameter (LxD) was defined as the distance from the midpoint between the anterior annulus of the aortic valve and the posterior annulus of the mitral valve to the apex in the apical long-axis image. In the parasternal long-axis image, the long axis of the left ventricle (LV) was determined by overlaying the parasternal image on the apical image. The external diameter (ExD) and the internal diameter (InD) of the LV at chordal level were measured in the direction of the short axis. The anterior part (-a) and the posterior part (-p) of both ExD and InD, which were divided by the long axis, were also measured. LxD, ExD, ExD-a, ExD-p and InD-p in HCM were greater than those in the normal subjects. Thus, the interventricular septum (IVS) in HCM was thickened inwardly and outwardly. In contrast, the left ventricular posterior wall (PW) in HCM showed only outward deviation. Thickness of the IVS and PW, and the excursion of the PW in HCM were greater than those in the normals, but the excursion of the IVS in HCM was smaller than those in the normals. We concluded that outward expansion of the IVS and PW occurs in HCM and distinct narrowing of the LV occurs only on the septal side in HCM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

[Stabilizing effect of prostaglandin E2 on lysosomal membrane of the rat dental pulp].

It has been reported that prostaglandin E2 (PGE2) had anti-inflammatory and analgesic effects, although it was well known that PGE2 combined with bradykinin (BK) showed proinflammatory and algesic effects. On the other hand, it has recently been known that BK showed an indirect activating effect on cathepsin B, a lysosomal enzyme, which may be mediated through calcium ion-dependent steps, followed by production of enkephalins (EK), endogenous anti-inflammatory and analgesic peptides, in the rat incisor pulp. The purpose of the present study is to examine whether PGE2 could have an effect on activation or release of cathepsin B in the pulp tissue, or not. Intact whole pulps of the rat incisors were incubated with N alpha-benzoyl-arginine-beta-naphthylamide (BANA), a substrate for cathepsin B, in the presence or absence of BK and PGE2 in Hanks solution (pH 7.4), in order to determine the BANA-degrading activity and EK producing activity. Both hydrocortisone and lidocaine which were stabilizers for lysosomal membrane markedly inhibited the BANA-degrading activities in the presence of BK, and in contrast, retinol, a labilizer for lysosomal membrane, significantly enhanced the BK-induced BANA-degrading activity. PGE2, like hydrocortisone and lidocaine, inhibited the BANA-degrading activity, in a dose-dependent manner, regardless of the presence or absence of BK, as well as resulted in a decrease of EK production in the pulp. Furthermore, both arginine, a cleavage product of BK by carboxypeptidase B, and arachidonic acid, which were endogenous activators for soluble guanylate cyclase, enhanced the BANA-degrading activity in the pulp homogenate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Endocrine and hemodynamic responses to total body hyperthermia in humans].

We investigated effects of total body hyperthermia (TBH) on endocrine and hemodynamic responses. A total of five treatments were performed in five patients with gastric cancer under neuroleptanesthesia with morphine followed by 0.2 to 0.4% enflurane. TBH was extracorporeally induced with veno-venous shunt incorporating with heat exchanger to keep their temperature between 41.5 degrees C and 42.0 degrees C for three hours. The patients were administered angiotensin to maintain tumor blood flow. Lactated Ringer's solution was administered at the rate of 10 to 15 ml.kg-1.hr-1 for five hours. Plasma cortisol levels decreased significantly to about one third of the control value after heating and the levels recovered to the control value after cooling. Plasma norepinephrine level increased significantly to about 7 to 9 times the control value following TBH, but this hormonal response was insufficient to reveal marked direct hemodynamic effects. The magnitude of fall in SVR was more significant in spite of the administration of angiotensin. Cardiac index increased significantly to about 2.0 to 2.6 fold of control value, but mean arterial blood pressure (MAP) decreased significantly to about two thirds to four fifths of the control value. Morphine relieved the hormonal response in ACTH and cortisol strongly, but morphine suppressed hemodynamics by decreasing SVR. Neither norepinephrine released from sympathetic nerve endings nor even 50 to 200 ng.kg-1.min-1 of angiotensin administered failed to restore SVR or MAP during hyperthermia.

Adult↗
PubMed1990

[The changes in total body water in patients with prolonged anesthesia and surgery].

We studied the influence of prolonged anesthesia and surgery on total body water (TBW) with tetrapolar bioelectrical impedance analysis (BIA). Eight patients who underwent prolonged anesthesia were selected as the subjects of the study and were compared with nine patients who underwent surgery of less than 3 hours. Plasma hormone concentrations were also examined. In the prolonged anesthesia patients, TBW increased significantly as compared with those of the patients who underwent short surgery (P less than 0.05). TBW showed the most remarkable increase on the first post operative day. Plasma ADH and aldosterone concentrations increased in the patients of both groups. However, we could not find a significant relationship between TBW and plasma hormone concentrations. BIA seems to be a useful method to estimate TBW during perioperative periods. However, further detailed investigation would be necessary to obtain a reliable technique in such an unstable condition.

Adult↗
PubMed1990

[Reaction products of sevoflurane with components of sodalime under various conditions].

Sevoflurane is reported to react with sodalime to resolve into several products. We examined the reaction products of sevoflurane when this anesthetic reacted with components of sodalime under various conditions. Analysis of reaction products was performed by gas chromatography using a 2m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime in a test tube at room temperature, only P1 was detected and all reaction products of P1 to P5 were identified when the test tube was heated at 50 degree C for 3 hours. Sodalime contains Ca (OH)2, NaOH, KOH and silicon dioxide. Reaction of sevoflurane with KOH produced P1 to P5 products even at room temperature. After the reaction of sevoflurane with NaOH or Ca (OH)2 at 50 degrees C, P1 to P5 or P1 only were detected on the chromatogram respectively. No peak of any reaction products was obtained after the reaction with silicon dioxide under various conditions. These results suggest that hydroxy group of sodalime component would increase reaction products of sevoflurane.

Anesthetics↗