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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 649 records · Page 36Linked to original sources
PubMed1990

Attenuation of arterial baroreceptor reflex response to acute hypovolemia during induced hypotension.

Preservation of the arterial baroreflex response is important to restore cardiac output and blood pressure by reflex sympathetic nerve activation in the event of sudden hypotension caused by acute blood loss during surgery. However, the arterial baroreflex may be significantly attenuated by both anesthetics and hypotensive agents. In isoflurane-anesthetized dogs, the authors investigated the arterial baroreflex response 1) to bolus injections of sodium nitroprusside (SNP), prostaglandin E1 (PGE1) and trimethaphan (TM); and 2) to rapid blood loss (5 ml/kg) before and during induced hypotension with SNP, PGE1, and TM by measuring mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA). Hypotension produced by both SNP and PGE1 was accompanied by an increase in RSNA and HR. The increase in RSNA and HR following the SNP bolus injection was significantly greater than that following injection of PGE1 (P less than 0.05). Trimethaphan was associated with a decrease in RSNA and HR. Rapid blood loss resulted in the same degree of MAP reduction (20 +/- 2 mmHg) before and during induced hypotension. Sensitivities of baroreflex, as evaluated by ratios of maximum changes in RSNA or HR to MAP (delta RSNA/delta MAP, delta HR/delta MAP), in response to rapid blood loss, were significantly suppressed during continuously induced hypotension, as compared with responses before induced hypotension. Despite the same degree of induced hypotension (70 +/- 5 mmHg of MAP), delta RSNA/delta MAP and delta HR/delta MAP in response to rapid blood loss were significantly greater with PGE1 than those with SNP (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Alprostadil↗
PubMed1990

[Fundamental studies on serological diagnosis of amoebiasis. 1. Application of amoebic antigen for CF test to ELISA].

We studied the establishment of enzyme-linked immunosorbent assay (ELISA) using amoebic antigen for complement fixation (CF) test. Optimal dilution for ELISA of sera from patients was 1:100, and that of CF-antigen was 1:400. The upper limit of the 99% critical range of the reaction of negative sera was 0.068 (cut-off level). Absorbance of sera from patients diluted 1:100 to antigen and antibody titers of ELISA were strongly correlated, so it was possible to estimate antibody titers from absorbance of serum diluted 1:100. ELISA and CF test were done to compare sensitivity of the tests using 63 sera from patients with invasive amoebic disease. The sensitivity of ELISA compared well with CF test (62 sera were positive by ELISA and 61 by CF test). Only one sample was both positive by ELISA and negative by CF test. This sample had low ELISA titers, so this discrepancy was mainly due to the sensitivity of CF test in detecting lower levels of antibody. These results suggested that the amoebic antigen for CF test can be applicable to ELISA, and this method was so sensitive and specific.

Amebiasis↗
PubMed1990

[An improved differential medium, CA medium, for differentiating Shigella].

We devised a Citrate-Acetate (CA) medium for rapidly differentiating Shigella. The medium consisted of 3.0 g of sodium citrate, 2.0 g of sodium acetate, 0.2 g of glucose, 1.0 g of dipotassium phosphate, 1.0 g of mono ammonium phosphate, 0.2 g of magnesium sulfate, 5.0 g of sodium chloride, 0.08 g of brom thymol blue, 15.0 g of agar, and 1000 ml of distilled water. An evaluation was made of the CA medium, for the rapid differentiation of 23 Shigella strains, 129 Escherichia coli strains and 130 isolates, that formed colourless colonies suspected to be Shigella on SS agar plate, from feces of healthy people. The results obtained were as follows 1) On the CA medium, all Shigella strains did not grow and there was no change in colour. 2) Positive growth rates of E. coli strains after incubation for 24 hr at 37 degrees C on CA medium, sodium acetate medium (Acet) and Christensen citrate medium (C-Cit) were 96.0%, 95.2% and 28.0%, respectively. Therefore, the positive growth rate of E. coli strains after incubation for 24 hr on CA medium was significantly higher (p less than 0.01) than that on C-Cit medium. 3) Positive growth rates of isolates after incubation for 24 hr at 37 degrees C on CA medium, Acet medium and C-Cit medium were 95.4%, 83.1% and 71.5%, respectively. Therefore, the positive growth rates of isolates after incubation for 24 hr on CA medium was significantly higher (p less than 0.01) than that on Acet medium and C-Cit medium.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1990

Functional cooperation of lens-specific and nonspecific elements in the delta 1-crystallin enhancer.

The expression of the chicken delta 1-crystallin gene is primarily regulated by the action of a lens-specific enhancer 1 kilobase long and located in the third intron of the gene (S. Hayashi, K. Goto, T. S. Okada, and H. Kondoh, Genes Dev. 1:818-828, 1987). The 120-base-long core segment is required for the activity of the delta 1-crystallin enhancer but by itself shows no activity. We analyzed the action of the core and adjoining segments of the delta 1-crystallin enhancer by two different approaches: (i) multiplication of the segments to express any cryptic effect and (ii) competition among enhancers for nuclear factors involved in enhancer action. We found that (i) the core defines a strictly lens-specific element, (ii) an adjoining segment defines an element with a broad specificity with regard to cell type, (iii) these elements cooperate in cis within the delta 1-crystallin enhancer, (iv) the multimers of these elements complete with each other and with delta 1-crystallin and simian virus 40 enhancers in trans apparently without sequence specificity but in a fashion reflecting the strength of the enhancers, and (v) the enhancers in trans do not affect the expression of enhancer-free genes, thereby ruling out the possibility of competition for general transcription factors. The last two observations raise the possibility that the enhancer segments interacting with different sequence-specific factors also interact with one other component involved in enhancer action.

Animals↗
PubMed1990

Involvement of endothelin in the regulation of human vascular tonus. Potent vasoconstrictor effect and existence in endothelial cells.

Endothelin, a recently discovered endothelium-derived peptide, has been reported to produce potent vasoconstriction in various vessels of experimental animals. To study the involvement of endothelin in the regulation of vascular tonus in humans, isolated human mesenteric arteries were investigated by both pharmacological and immunohistochemical methods. The vasoconstrictor action of endothelin-1 was examined on ring segments of human mesenteric arteries. Endothelin-1 induced a slowly developing and sustained contraction, with an EC50 value (half-maximal effective concentration) of 2.9 x 10(-9) M, two orders of magnitude smaller than that of norepinephrine (EC50 of 3.9 x 10(-7) M), indicating that the vasoconstrictor action of endothelin-1 is about 100 times more potent than that of norepinephrine. The contractile effect of endothelin-1 was affected neither by adrenergic, cholinergic, histaminergic, nor serotonergic antagonists, nor by inhibitors of arachidonic acid metabolism. The vasoconstrictor response to endothelin-1 was effectively antagonized by nicardipine, a dihydropyridine Ca2+ channel blocker. Endothelin-1 profoundly augmented contractile response to Ca2+ in partially depolarized tissues. Immunohistochemical studies revealed for the first time that endothelin-like immunoreactivity was localized in endothelial cells of human mesenteric artery. The results of the present study indicate that endothelin-1 is one of the most potent vasoconstrictors in the human mesenteric artery and that it induces vasoconstriction via an ultimately accelerating Ca2+ influx through voltage-dependent Ca2+ channels. Since endothelin-1 can be located in human endothelial cells, it may play an important physiological or pathophysiological role.

Adult↗
PubMed1990

Enzyme-catalyzed synthesis of a bioactive oligopeptide in nearly anhydrous solvents with polyethylene glycol-modified proteases.

An oligopeptide, L-arginyl-glycyl-L-aspartyl-L-serine, having cell attachment activity was synthesized from the respective aminoacids carrying suitable protecting residues, by using carboxymethyl polyethylene glycol (PEG)-modified proteases in organic solvents. Papain, trypsin, and alpha-chymotrypsin were modified with PEG. Organic solvents used were 1,1,1-trichloroethane, chloroform and chloroform/ethyl cellosolve (1:1) mixture. Identification of the products was done by gel permeation chromatography (GPC) and thin layer chromatography (TLC).

Amino Acid Sequence↗
PubMed1990

Endothelin receptor is coupled to phospholipase C via a pertussis toxin-insensitive guanine nucleotide-binding regulatory protein in vascular smooth muscle cells.

The mechanisms of endothelin-1 (ET) actions were investigated in cultured rat aortic vascular smooth muscle A-10 cells. The A-10 cells have a single class of high affinity binding sites for ET with an apparent Mr of 65,000-75,000 on SDS-PAGE. Stimulation of cells with ET induces mobilization of Ca2+ from both intra- and extracellular pools to produce a biphasic increase in cytoplasmic free Ca2+ concentration. ET increases cellular levels of inositol trisphosphate and 1,2-diacylglycerol, indicating activation of phospholipase C by ET. ET stimulates production of inositol phosphates in membranes prepared from A-10 cells in the presence of guanosine 5'-O-(thiotriphosphate) (GTP gamma S), but not in its absence. Further, specific binding of 125I-labeled ET to A-10 cell membranes is shown to be inhibited by GTP gamma S in a dose-dependent manner. Treatment of A-10 cells with pertussis toxin induces ADP-ribosylation of a 41,000-D membrane protein but fails to block the ET-induced increases in inositol phosphate production and Ca2+ mobilization. These results indicate that the receptor for ET is coupled to phospholipase C via a guanine nucleotide-binding regulatory protein which is distinct from the pertussis toxin substrate in A-10 cells.

Animals↗
PubMed1990

Expression of c-fos and c-myc proto-oncogenes in human adrenal pheochromocytomas.

We examined c-fos and c-myc expressions in pheochromocytoma tissues from six patients. All samples contained c-fos and c-myc transcripts, whereas mRNA from bovine adrenal medulla, as a control, did not contain these transcripts at detectable levels. Southern blot analysis revealed no amplification and no rearrangement of c-fos and c-myc genes. We also examined the gene expression of insulin-like growth factor-II (IGF-II), a mitogen for rat pheochromocytoma cells exerted by autocrine or paracrine fashion. All samples from the pheochromocytomas contained IGF-II transcripts as well as c-fos and c-myc transcripts. The constitutive expressions of c-fos and c-myc genes may be interpreted to mean that pheochromocytoma is in a state of growth stimulation in vivo by growth factors, including IGF-II.

Adrenal Gland Neoplasms↗
PubMed1990

Efficacy of high-frequency jet ventilation in cardiac tamponade.

To evaluate the effects of high-frequency jet ventilation (HFJV) (f = 60, 120 breaths/min) and conventional mechanical ventilation (CMV) (f = 10, 20) during equivalent conditions of cardiac tamponade, stroke index (SI), intrapericardial pressure (IPP), airway pressure (P(aw)), and cardiac pressures were measured in anesthetized, paralyzed, chest-closed dogs with the same levels of PaCO2. Cardiac tamponade was produced by infusing normal saline into the intrapericardial space to increase IPP to either 8 mm Hg (group 1, n = 8) or 12 mm Hg (group 2, n = 8). Stroke index in group 1 was 7.3 +/- 0.8 during CMV (f = 10), 8.1 +/- 0.7 during CMV (f = 20), 10.9 +/- 1.4 during HFJV (f = 60), and 10.7 +/- 1.2 (mL.beat-1.m-2) during HFJV (f = 120). Stroke index in group 2 was 4.1 +/- 0.7, 5.1 +/- 0.5, 7.2 +/- 0.5, and 6.7 +/- 0.5 (mL.beat-1.m-2), respectively. In both IPP groups, stroke index values during HFJV were significantly higher than during CMV; however, there were no significant differences in mean left and right atrial transmural pressures between HFJV and CMV. Peak IPP, mean P(aw), and peak P(aw) during HFJV were significantly lower than those during CMV. The results indicate that HFJV with lower mean and peak Paw, and with lower mean and peak IPP, can result in higher cardiac output than CMV in cardiac tamponade. Thus, HFJV may be superior to CMV in the clinical management of cardiac tamponade.

Animals↗
PubMed1990

Study on the endothelin gene and its expression.

Endothelin (ET) is a potent vasoconstrictor peptide produced by vascular endothelial cells. Three distinct human endothelin genes were cloned and analysed. The results demonstrated that there were three distinct mRNAs for ET and that TPA-responsive element, mRNA stabilizing sequence, motifs for binding site of nuclear factor 1 and acute phase reactant regulatory elements were recognized in preproform ET-1 gene.

Animals↗
PubMed1990

Sensitive detection of Mycoplasma pulmonis by using the polymerase chain reaction.

Detection of Mycoplasma pulmonis was examined by using the polymerase chain reaction (PCR) for amplifying a specific DNA sequence. In gel electrophoresis which was conducted to detect the amplified products, only 1 pg of M. pulmonis DNA could be detected following 30 cycles of amplification, while no amplified product was detected even from 1 microgram of M. arthritidis or M. neurolyticum DNA. Furthermore, 10 colony-forming units of M. pulmonis could be detected by direct amplification from the mycoplasma suspension. These results suggest the usefulness of the PCR as a highly sensitive, specific, and rapid method for direct detection of M. pulmonis.

Base Sequence↗
PubMed1990

[Local irritancy study of cefpirome sulfate].

As a series of safety studies of cefpirome sulfate (CPR), its local irritancy was examined in rabbits after the following treatments: intracutaneous injection (single), application into the conjunctival sac of the eye (single), intramuscular injection (single, 7-day repeated), and intravenous injection (8-day repeated). In addition, the hemolysis test was carried out with human blood. When CPR was injected intracutaneously at a high concentration of 20%, its irritating effects were only equal to or slightly stronger than those of distilled water for injection and Na2SO4 solution. The same concentration of the compound applied into the conjunctival sac had little irritancy to the eye. In the single intramuscular administration experiment, muscular changes caused by 10% CPR were comparable to those by 0.75% acetic acid, slightly severer than those by physiological saline, and slighter than those by 6% acetic acid at 2 days after administration, but at 7 days, the changes were apparently slighter than those by 0.75% acetic acid. CPR is classified under Grade 3 according to the draft guidelines for local tolerability studies issued by the Ministry of Health and Welfare of Japan. The repeated intramuscular administration experiment showed the following results. Muscular changes caused by 10% CPR were comparable to those by physiological saline and slighter than those by 0.75% acetic acid, 5% cefotetan (CTT) and 20% cephalothin sodium (CET) at 2 days after the last administration. At 7 days, the changes were slightly severer than those by physiological saline, but slighter than those by the other control solutions. Microscopically, a tendency toward recovery was marked. In the vascular irritancy experiment, the 10% CPR group showed thrombus macroscopically on and after day 5 of dosing. Microscopy at the end of the 8-day administration period revealed thrombus and organized thrombus. In the 20% CET group, thrombogenesis was slighter than that in the 10% CPR group, while perivascular changes were severer. The changes caused by 5% CTT (thrombogenesis, perivascular changes) were somewhat severer than those by 10% CPR. In the hemolysis test, 10% CPR solution applied to fresh blood from adult men caused to hemolysis when determined by the macroscopic or spectrophotometric method.

Animals↗
PubMed1990

Increased maternal plasma concentration of endothelin-1 during labor pain or on delivery and the existence of a large amount of endothelin-1 in amniotic fluid.

The concentration of endothelin-1 (ET-1) in plasma and amniotic fluid from normal pregnant women was determined by a sensitive sandwich-enzyme immunoassay system, established recently. The plasma ET-1 level increased gradually during normal pregnancy as the pregnancy advanced, the levels (0.40 +/- 0.02 pmol/l, n = 45) being significantly (p less than 0.05) higher after 29 weeks of gestation than those (0.32 +/- 0.01 pmol/l, n = 30) before 28 weeks of gestation. The plasma ET-1 level during labor pain was significantly higher (0.59 +/- 0.06 pmol/l, n = 10) than that (0.40 +/- 0.02 pmol/l, n = 45) in the 3rd trimester of pregnancy without labor pain (p less than 0.02). Moreover, a high level of ET-1 (17.38 +/- 0.25 pmol/l, n = 18) was detected in amniotic fluid on term delivery. The ET-1 level in amniotic fluid was significantly higher than the levels in maternal and umbilical cord plasma (p less than 0.001 and p less than 0.001, respectively). After delivery the maternal ET-1 level decreased gradually and 2 day postpartum ET-1 levels reached the normal non-pregnant level.

Adult↗
PubMed1990

[Evaluation of serum S100ao protein in patients with renal cell carcinoma].

In order to evaluate the clinical significance of S100ao protein, we measured serum S100ao protein in 36 patients with renal cell carcinoma by EIA developed by Kimura et al. In addition, the distribution of S100ao protein was studied by the immunohistochemical method. Previous study demonstrated that mean level of serum S100ao protein in healthy volunteers was 203 +/- 107 pg/ml, therefore the cut off level was set to 524 pg/ml. The results obtained in this study were as follows: 1) The mean level of serum S100ao protein was 1162 +/- 2056 pg/ml, and its positive rate was 44% in 36 patients with renal cell carcinoma. When the patients were divided into 2 groups according to tumor stage, the mean level of serum S100ao protein in the high stage group was significantly higher than that in the low stage group (p less than 0.01). 2) In the sequential study of serum S100ao protein, patients with progressive disease showed a gradual increase in the level of serum S100ao protein while patients with no evidence of tumor showed a normal level of serum S100ao protein. 3) There was no correlation between the level of serum S100ao protein and the histological grade of renal cell carcinoma. 4) Immunohistochemical analysis (10 cases) showed that S100ao protein was observed in all of 10 renal cell carcinomas. Thus, the present study suggests that serum S100ao protein might be a useful clinical marker especially in monitoring patients with renal cell carcinoma.

Adult↗
PubMed1990

Cloning and nucleotide sequence of the KHR killer gene of Saccharomyces cerevisiae.

The KHR gene cloned from a genomic library was on 4.7-kbp DNA fragment and was inserted into YCpG11 vector (KHR-YCp) and YEp vector (KHP-YEp). Transformants with KHR-YEp could secrete 3-4 times as much killer toxin into the media as the donor strain. The complete nucleotide sequence of the KHR gene was analyzed. It was found that the KHR gene consisted of 888 bp. It was suggested that this protein was processed before being secreted into the media, because its molecular mass presumed from the nucleotide sequence was larger than that of the mature killer toxin.

Amino Acid Sequence↗
PubMed1990

Chromosomal transformation in Saccharomyces cerevisiae with DNA isolated by pulse field gel electrophoresis.

We isolated and purified yeast chromosome DNA molecules using pulse field gel electrophoresis (PFG). The isolated DNA had nearly the same size as the native chromosomal DNA on PFG. We could directly transform Saccharomyces cerevisiae yeasts with it, and obtain transformants that were selected by complementation of several markers. They had new chromosome DNA bands observed on PFG. The new chromosome was very stable during mitosis and mating processes, and each of the three homologous chromosomes in the derivative zygotes of transformants was separated equally in daughter cells.

DNA, Fungal↗
PubMed1990

[Percutaneous dissolution of uric acid and cystine stones causing acute ureteral obstruction].

Four cases with ureteral obstruction due to uric acid or cystine stones were treated successfully by percutaneous irrigation with sodium bicarbonate or tromethamine-E. These cases underwent percutaneous nephrostomy for the reason of prolonged complete obstruction (case 1), sustained pyelonephritis (case 2) or decreased renal function (case 3 and 4). Two catheters were placed through the nephrostomy tract before irrigation, 6 Fr. ureteral catheter just above the ureteral stone and 10 Fr. pigtail or 12 Fr. Malecot catheter in the renal pelvis. The ureteral stones were markedly reduced in size and passed spontaneously after 6-11 days' duration of irrigation in three cases. In case 2, the remaining stone was removed transurethrally after 14 days' duration of irrigation, and was found to be composed of organic matrix. Percutaneous dissolution is considered to be a safe and reliable method and may be an alternative way of treating uric acid or cystine stone causing acute ureteral obstruction.

Acute Disease↗