Unrecognized migration of an entire guidewire on insertion of a central venous catheter into the cardiovascular system.
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Aged↗
Biomedical subjects
K Hotta
Publications and source records attributed to K Hotta.
ROM7/BEM4 encodes a novel protein that interacts with the Rho1p small GTP-binding protein in Saccharomyces cerevisiae.
The RHO1 gene encodes a homolog of the mammalian RhoA small GTP-binding protein in the yeast Saccharomyces cerevisiae. Rho1p is localized at the growth site and is required for bud formation. The RHO1(G22S, D125N) mutation is a temperature-sensitive and dominant negative mutation of RHO1, and a multicopy suppressor of RHO1(G22S, D125N), ROM7, was isolated. Nucleotide sequencing of ROM7 revealed that it is identical to the BEM4 gene (GenBank accession number L27816), although its physiological function has not yet been reported. Disruption of BEM4 resulted in the cold- and temperature-sensitive growth phenotypes, and cells of the deltabem4 mutant showed abnormal morphology, suggesting that BEM4 is involved in the budding process. The temperature-sensitive growth phenotype was suppressed by overexpression of RHO1, ROM2, which encodes a Rho1p-specific GDP/GTP exchange factor, or PKC1, which encodes a target of Rho1p. Moreover, glucan synthase activity, which is activated by Rho1p, was significantly reduced in the deltabem4 mutant. Two-hybrid and biochemical experiments revealed that Bem4p directly interacts with the nucleotide-free form of Rho1p and, to lesser extents, with the GDP- and GTP-bound forms of Rho1p, although Bem4p showed neither GDP/GTP exchange factor, GDP dissociation inhibitor, nor GTPase-activating protein activity toward Rho1p. These results indicate that Bem4p is a novel protein directly interacting with Rho1p and is involved in the RHO1-mediated signaling pathway.
Base Sequence↗
Reactivity of glomerular and serum IgA1 to jacalin in IgA nephropathy.
To analyze O-linked oligosaccharides (O-glycans) in the hinge region of IgA1 in IgA nephropathy (IgAN), the reactivity of IgA1 to jacalin, which specifically binds to O-glycans, was investigated. Initially, renal biopsy specimens from 5 patients with IgAN and 3 patients with other renal diseases were investigated in an immunofluorescence study with jacalin, monoclonal antihuman IgA1 and IgA2 antibodies. All of the renal biopsy specimens of IgAN and none of other renal diseases were positively stained by both FITC-labeled jacalin and monoclonal anti-IgA1 antibody. The glomerular staining patterns of FITC-jacalin were similar to those of the monoclonal anti-IgA1 antibody. IgA2 was negative in all specimens. Based on the positive reactivity of deposited IgA1 to jacalin, the binding ability of serum IgA1 to jacalin was evaluated by inhibition assay using D-galactose in patients with IgAN (n = 58), other primary glomerulonephritides (PGN) (n = 41), and healthy controls (n = 52). The frequencies of the patients with serum IgA1 having a high affinity for jacalin were significantly greater in IgAN (19/58, 32.8%) compared with the healthy controls (2/52, 3.8%) and other PGN (4/41, 9.8%). These results suggested that the increased reactivity of O-glycan(s) in the IgA1 hinge region to jacalin is due to an unusual glycosylation of serum IgA1 in IgAN.
Adult↗
Cleavage specificity of coxsackievirus 3C proteinase for peptide substrate (2): Importance of the P2 and P4 residues.
Coxsackievirus 3C proteinase (3Cpro) cleaves between Gln and Gly, but additional amino acids are required to constitute a cleavage site. To investigate the additional sequence requirements, cleavages of the peptide substrate, and its derivatives were examined. Substitutions of each residue from the P2 to P5 positions showed the importance of the P2 Phe and P4 Ala for recognition by 3Cpro.
3C Viral Proteases↗
Association of asialo-galactosyl beta 1-3N-acetylgalactosamine on the hinge with a conformational instability of Jacalin-reactive immunoglobulin A1 in immunoglobulin A nephropathy.
The O-glycans in Jacalin-binding immunoglobulin A1 (IgA1) were released by gas-phase hydrazinolysis and were fractionated by gel filtration and reversed-phase HPLC. Four peaks (P1 to P4) were obtained. There was a significant shift from Peak 2 (monosialylated Gal beta 1-3GalNAc) to Peak 4 (asialo-Gal beta 1-3GalNAc) in the IgA-nephropathy group compared with the negative control group (P < 0.05). One of the functions of the carbohydrate side chains is to stabilize the three-dimensional structure of the glycopeptides. In order to evaluate the stability of the Jacalin-binding IgA1 molecule, the increase in turbidity as a consequence of the increase of the aggregated IgA1 level under the condition of high temperature (63 degrees C) was observed. The increase in the turbidity was significantly higher in the IgA nephropathy group compared with the negative control group (21.7 vs. 5.9% at 150 min, P < 0.02). From a sample of IgA1 solution that had originated from a pooled normal serum, heat-tolerant (nonaggregated) and intolerant (aggregated) IgA1 molecules were separated by gel filtration. The heat-intolerant IgA1 had lower amounts of sialic acid (27.4 micrograms/mg IgA1) than the tolerant IgA1 (37.6 micrograms/mg IgA1). Further, the analysis of the O-glycans released from another IgA1 sample by the hydrazinolysis revealed that the ratio of the asialo-Gal beta 1-3GalNAc/total Gal beta 1-3GalNAc in the heat-in-tolerant IgA1 (27.2%) was increased compared with that in the heat-tolerant IgA1 (18.2%). From these results, it was suggested that unusual glycosylation on the hinge region of Jacalin-binding IgA1 induced an insufficient conformational stiffness to the hinge peptide, resulting in the aggregation of the IgA1 molecule in IgA nephropathy.
Acetylgalactosamine↗
Enzymatic 2'-N-acetylation of arbekacin and antibiotic activity of its product.
Aminoglycoside antibiotics (AGs) with a free 2'-amino group were subjected to enzymatic N-acetylation using a cell free extract that contained an aminoglycoside 2'-N-acetyltransferase, AAC (2'), derived from a kasugamycin-producing strain of Streptomyces kasugaensis. TLC and antibiotic assay of the incubated reaction mixtures revealed that a modified compound retaining substantial antibiotic activity was formed from arbekacin (ABK), while modification of the other AGs resulted in the marked decrease in antibiotic activity. Structure determination following isolation from a large scale reaction mixture showed the modified ABK to be 2'-N-acetyl ABK. In addition, 2',6'-di-N-acetyl ABK was formed as a minor product. The same conversion also occurred with dibekacin (DKB) resulting in the formation of 2'-N-acetyl DKB and 2',6'-di-N-acetyl DKB. MIC determination showed antibacterial activity (1.56 approximately 3.13 micrograms/ml) of 2'-N-acetyl ABK against a variety of organisms. By contrast, 2'-N-acetyl DKB showed no substantial antibiotic activity. We believe 2'-N-acetyl ABK has the highest and broadest antibacterial activity, compared with known N-acetylated AGs.
Acetylation↗
Mechanism of multiple aminoglycoside resistance of kasugamycin-producing Streptomyces kasugaensis MB273: involvement of two types of acetyltransferases in resistance to astromicin group antibiotics.
The biochemical basis for the multiple resistance to aminoglycoside antibiotics (AGs) of kasugamycin-producing Streptomyces kasugaensis MB273 was studied. The strain was resistant to a wide range of deoxystreptamine (DOS)-containing AGs as well as astromicin (ASTM) group antibiotics. These AGs strongly inhibited in vitro polyU-directed polyphenylalanine-synthesis using ribosomes from the strain, while they were acetylated and inactivated by the MB273 cell free extract supplemented with acetyl-CoA. It seemed thus likely that the acetyltransferase activity played a critical role for the multiple AG resistance. The acetylation was selective to AGs with 2'-NH2, suggesting the involvement of aminoglycoside 2'-N-acetyltransferase, AAC (2'). Interestingly, the acetylation of istamycin B (ISM-B; an ASTM group AG) resulted in the formation of two different products (1-N-acetyl ISM-B and 2"-N-acetyl ISM-B) at a similar ratio. In this context, an AAC (2') gene cloned as an ISM-B resistance gene from the strain MB273 directed the conversion of ISM-B to only 1-N-acetyl ISM-B. It seemed likely that two types of AACs [AAC(2') and a novel one] were involved in the mechanism of resistance to ASTM group AGs.
Acetylation↗
[Emergency internal carotid artery ligation using near infrared spectroscopy].
We anesthetized a patient who received an emergency internal carotid artery ligation. Regional cerebral oxygen saturation (rSO2) was measured with near infrared spectroscopy (NIRS) during the whole anesthetic course. The sensor was placed on the left forehead of the patient. Decrease in blood pressure was reflected in the decrease in rSO2. The rSO2 was not altered by internal carotid ligation. However, cerebral infarction in the middle cerebral artery region, the onset of which remained unclear, was revealed postoperatively, regardless of a stable rSO2 during the operation. This monitor may provide useful information regarding the cerebral circulation during the operation in such a case as the present one, but this monitor reflects only the oxygenation of the region on which the sensor was placed. Thus, we should keep in mind the limitation in detecting cerebral dysfunction using NIRS.
Anesthesia, General↗
[Clinical evaluation of a new programmable syringe infusion pump].
A new programmable syringe infusion pump, Auto Syringe Model AS 40 A, was evaluated for infusion of muscle relaxants, vasodilators and opioids in 4 surgical patients. Every drug mentioned above was easily adjusted according to surgical requirement in these patients. Auto Syringe Model AS40A is light and compact. Its major advantages lie in the mechanisms for delivery of a bolus dose and automated delivery of intermittent doses, automatic rate calculation, and the applicability to various sizes of syringes. Auto Syringe Model AS40A was found to be very useful for intravenous infusion of drugs.
Adult↗
The presence of 2-keto-3-deoxygluconic acid and oxoaldehyde dehydrogenase activity in human erythrocytes.
2-Keto-3-deoxygluconic acid (3-DGA) is produced from 3-deoxyglucosone (3-DG:a highly reactive glycation intermediate) through oxidation by the enzyme oxoaldehyde dehydrogenase (OAD) in animals. We developed a specific assay method for 3-DGA using high-performance liquid chromatography [Fujii, E. et al. (1994) J. Chromatogr. B 660, 265-270] and measured it in the hemolysate and plasma of diabetic patients and healthy subjects. Both human erythrocytes and plasma contained considerable amounts of 3-DGA. However, human erythrocyte contained about 30-50 times higher 3-DGA than human plasma did and also had the same ability to convert 3-DG to 3-DGA as OAD had. Erythrocyte 3-DGA levels of diabetic patients were 990 +/- 370 nmol/gHb (n = 57, Mean +/- SD) and were significantly higher compared with healthy subjects (527 +/- 194 nmol/gHb, n = 7, p < 0.01). In all diabetic patients and healthy subjects (n = 64), there was only one patient who had a very low level of erythrocyte 3-DGA and lacked the ability to convert 3-DG to 3-DGA. When erythrocytes were incubated at 37 degrees C for 8 hours in phosphate buffer containing 0.35 mM 3-DG, 3-DG was easily taken into the erythrocytes and was converted to 3-DGA. Our results suggest the contribution of OAD not only to the prevention of glycation of hemoglobin but also to that of blood vessels by scavenging plasma 3-DG into erythrocytes.
Adult↗
Effects of sodium thiosulfate on the pharmacokinetics of unchanged cisplatin and on the distribution of platinum species in rat kidney: protective mechanism against cisplatin nephrotoxicity.
To investigate the mechanism underlying the protective effect against cisplatin (CDDP) nephrotoxicity of its antidote, sodium thiosulfate (STS), the effects of STS on the pharmacokinetics of unchanged CDDP and on the distribution of unchanged CDDP and high and low molecular mass metabolites (fixed and mobile metabolites) in the kidney 1 min after a bolus injection of CDDP (5 mg/kg) to rats were studied. A decrease in the plasma concentration of unchanged CDDP and an increase in the plasma concentration of mobile metabolites were observed in the rats after the bolus injection of CDDP in combination with STS infusion for 30 min (1200 mg/kg). Although STS accelerated platinum excretion during the first 10 min after CDDP injection, unchanged CDDP was not excreted in the urine in the STS-treated rats. Total kidney platinum 1 min after the bolus injection of CDDP was detected mainly as unchanged CDDP (86% of the total platinum) in the rats given CDDP alone. However, in the STS-treated rats, the total kidney platinum was decreased to 62% of the level in the rats given CDDP alone, and the platinum species detected in the kidney were mainly mobile metabolites. Only 24% of the total kidney platinum was detected as unchanged CDDP in the STS-treated rats. The loss of body weight and increases in BUN and serum creatinine levels usually observed after a bolus injection of CDDP were completely prevented by STS coadministration. The present study provides information about unchanged CDDP pharmacokinetics and the distribution of unchanged CDDP and some of its generic metabolites in the kidney when STS is coadministered as an antidote. These results show that the protective effect of STS against CDDP nephrotoxicity can be attributed to the formation of inactive mobile metabolites by a direct reaction between unchanged CDDP and STS in the systemic circulation, resulting in a reduction in the amount of unchanged CDDP in the kidney.
Analysis of Variance↗
Aminoglycosides and aminocyclitols (other than streptomycin).
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Actinomycetales↗
Gastric mucosal damage accompanying changes in mucin induced by histamine in rats.
The present study was carried out to clarify the mechanism of histamine-induced gastric mucosal damage in rats. Following an injection of histamine (80 mg/kg), pH dropped within 30 min. and then recovered control value (pH = 4-5) 4 hr later. The decrease in mucosal mucin content and the appearance of haemorrhagic erosions followed the drop in pH. The recovery of mucosal mucin content preceded the healing of haemorrhagic erosions and pH recovery to the control level. Histamine also caused qualitative changes in corpus mucins. These qualitative changes induced by histamine were eliminated at 7 hr following the administration of histamine. It appears from the present results that increase in HCl and decrease in mucins induced by histamine bring about gastric damage.
Animals↗
[Scanning electron microscopic study of the development of crystalline lens fiber].
To elucidate the 3-dimensional structural development of the albino rabbit lens fiber, and to study how cataracts affect these fibers, the lenses from rabbits 1, 2, 4, and 8 weeks old, and from 8 week old rabbits with cataracts caused by naphthalene were examined with a scanning electron microscope. The results were: 1) Normal rabbit: The ratio of the length of the anterior suture line to the diameter of the lens gradually rose from 1 to 4 weeks and then reached a plateau. The ratio of the length of the posterior suture line was constant from the first week on. Fibers were wider in lenses from older rabbits, except for those in the middle of the suture line. Ball-and-socket junctions were common on the anterior side and were concentrated in the area of the paraanterior suture line of lenses from older animals. The lateral large processes were only noted near the anterior suture line, and in extended direction from its end. The likelihood of finding edge processes, especially in the area of middle anterior and posterior sections, rose with age. 2) Rabbit exposed to Naphthalene: The rate of increase of the length of the anterior suture line and the diameter of the lens were both low, but their ratio did not differ from that of a normal rabbit's lens. On the contrary, the growth rate of the posterior suture line was much greater than that of the diameter. The peculiarity of distribution of edge processes and width found in normal lens fibers was not found in naphthalene-affected fibers.
Animals↗
Autophosphorylation of insulin receptor in a patient with Werner's syndrome associated with insulin resistant diabetes mellitus.
The tissue sensitivity to insulin was evaluated using the hyperinsulinemic euglycemic clamp technique in a 44-year old male with Werner's syndrome associated with diabetes mellitus. In addition, the autophosphorylation of insulin receptors and the number of autophosphorylated insulin receptors were measured in his erythrocytes by a new enzyme-linked immunosorbent assay. He had an increased serum insulin level (30.5 microU/ml) in addition to hyperglycemia (226 mg/dl), suggesting that he had insulin-resistant diabetes mellitus. A clamp study revealed that his insulin-stimulated glucose disposal rate (2.80 mg/kg/min) was comparable to that in noninsulin-dependent diabetes mellitus (4.14 +/- 1.94 (SD) mg/kg/min, n = 23). The number of autophosphorylated insulin receptors per 300 microliters of erythrocytes was also identical to that in normal control subjects. In addition, the autophosphorylation of insulin receptors determined at six different insulin concentrations was within the normal range, even when it was expressed as per 300 microliters of erythrocytes as well as per unit receptor. These results demonstrate that insulin resistance in the patient with Werner's syndrome is caused by a defect that cannot be detected by means employed in this study, and suggest that the defect is present at the steps distal to the autophosphorylation of tyrosine kinase of insulin receptors.
Adult↗
PCR inhibition assay for DNA-targeted antibiotics.
DNA amplification by polymerase chain reaction (PCR) should be inhibited if the target for amplification region in the template DNA is nicked or cut. Based on this premise, we established a sensitive and differential assay using PCR to detect antibiotics that act on DNA. After template lambda DNA (10 pg) was incubated with antibiotics (10 approximately 20 ng) at 37 degrees C for 30 minutes in a 5 microliters reaction volume, a PCR assay (10 microliters reaction volume; 25 approximately 30 cycles) was performed under the conditions we modified, resulting in amplification of a 500 bp fragment of lambda DNA which was monitored by agarose gel electrophoresis. Among the several antibiotics examined, the anthracyclines, bleomycin, D-cycloserine and mitomycin C clearly inhibited the PCR amplification reaction, whereas actinomycin D and ofloxacin did not. Preincubation of template DNA in the presence of Fe++ was necessary for bleomycin and cycloserine to exhibit marked inhibition of PCR. Mitomycin C exhibited the inhibition in the presence of DTT and Cu+. By contrast, non-DNA-acting antibiotics (200 ng) such as aminoglycosides, beta-lactams, and macrolides showed no inhibition. The PCR-amplified fragment from lambda DNA was not degraded by incubation with the antibiotics (20 ng) that inhibited PCR. Furthermore, ethylacetate extracts of the cultured broths of actinomycetes proved to be suitable as samples for this PCR inhibition assay.
Actinomycetales↗
[Binding of IgA1 to monocyte/macrophage cell lines (THP-1, U937) in IgA nephropathy--a possible role of O-glycan in the IgA1 molecule].
IgA1 is an exceptional serum glycoprotein because it has O-glycans in the hinge region. It has been observed that the monocyte/macrophages infiltrate within the glomeruli in IgA-N. On the other hand, it is well established that the carbohydrate side chains (N-glycans) of the IgG molecule play a role in the binding of IgG to Fc receptors. Therefore, the binding of IgA1 to monocyte/macrophage cell lines was observed with the aim of clarifying the role of the O-glycan side chains in IgA-N in the initial mechanism of glomerular damage due to the interaction between the O-glycan chains on the IgA1 molecule and infiltrating monocyte/macrophages. Two human myelomonocytic cell lines, THP-1 and U-937, were activated and incubated with separated IgA1 (IgA-N, n = 16; other glomerulonephritides (other GN), n = 15; healthy controls, n = 9). The binding attitude of IgA1 to the cell lines was observed by flow immunofluorometry using a FACScan. FACScan showed that the binding of IgA1 to both of the stimulated monocyte/macrophage cell lines was increased in IgA-N compared to the normal controls and other GN. The binding of IgA1 to THP-1 was partially, but definitely inhibited by adding 100 mM melibiose (19.6 +/- 7.7%) and galactose (13.1 +/- 2.9%), but not glucose (2.9 +/- 2.2%), lactose (4.7 +/- 4.7%) and mannose (3.3 +/- 3.3%). These results suggested that THP-1 had a receptor that recognized the O-glycan in the IgA1 hinge region.(ABSTRACT TRUNCATED AT 250 WORDS)
Cell Line↗
Concentration of soluble vascular cell adhesion molecule-1 (VCAM-1) correlated with expression of VCAM-1 mRNA in the human atherosclerotic aorta.
BACKGROUND: Adherence of circulating monocytes and lymphocytes to arterial endothelium is detectable early in experimental and human atherosclerotic plaque formation. The purpose of the present study was to assess vascular cell adhesion molecule-1 (VCAM-1) mRNA expression and the properties of soluble VCAM-1 in patients with atherosclerotic aortic disease. METHODS: Thirteen patients with aortic disease (mean age 64 years) and 40 healthy volunteers (mean age 32 years) were included in the study. We investigated the expression of VCAM-1 mRNA in eight human aortic specimens obtained during surgery. Of these, two showed no evidence of atherosclerotic plaque formation [aortic dissection (n = 1) and annuloaortic ectasia (n = 1)], whereas six had demonstrable complex atherosclerotic formation [abdominal aneurysm (n = 5) and aortic dissection (n = 1)]. The RNase protection assay was performed using an alpha 32P-labeled 121 base pair VCAM-1 cRNA probe. We also measured concentrations of the soluble VCAM-1 using two-site enzyme immunoassays in 40 healthy volunteers and in 13 patients with abdominal and thoracic aortic aneurysms. RESULTS: In human samples, VCAM-1 mRNA expression was found to be higher in the six patients with complex atherosclerotic formation [optical density (OD), 0.71 +/- 0.14] than in the two patients with no evidence of atherosclerotic plaque formation (OD, 0.53 and 0.49). The concentration of serum soluble VCAM-1 was higher (850 +/- 298 ng/ml) in patients with aortic or thoracic disease than in the healthy volunteers (494 +/- 94 ng/ml). In addition, there was a relationship between VCAM-1 mRNA expression and the concentration of soluble VCAM-1 (y = 2088x-554, r2 = 0.73). CONCLUSION: VCAM-1 expression is higher in the human aorta in patients with atheromatous changes. Furthermore, concentrations of soluble VCAM-1 may provide important information about endothelial activation or in-vivo damage.
Adult↗