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Biomedical subjects

K Nishitani

Publications and source records attributed to K Nishitani.

At least 19 recordsLinked to original sources
PubMed2001

Endoxyloglucan transferase is localized both in the cell plate and in the secretory pathway destined for the apoplast in tobacco cells.

Intracellular trafficking of enzymes responsible for constructing and modifying the cell wall architecture in plants is mostly unknown. To examine their translocation pathways, we employed an endoxyloglucan transferase (EXGT), a key enzyme responsible for forming and rearranging the cellulose/xyloglucan network of the cell wall. We traced its intracellular localization in suspension-cultured cells of tobacco bright yellow-2 by means of green fluorescent protein-fusion gene procedures as well as by indirect immunofluorescence. During interphase the protein was extensively secreted into the apoplast via the endoplasmic reticulum-Golgi apparatus network, whereas during cytokinesis, the protein was exclusively located in the phragmoplast and eventually transported to the cell plate. These results clearly indicate commitment of EXGT protein to the construction of both the cell plate and the cell wall. This study also visualized the process of phragmoplast development at a level of vesicle translocation in the living cell.

Amino Acid Sequence↗
PubMed1999

Endoxyloglucan transferase cDNA isolated from pea roots and its fluctuating expression in hydrotropically responding roots.

We isolated an endoxyloglucan transferase cDNA (Ps-EXGT1) from the roots of an agravitropic pea mutant, ageotropum. The putative product of the cDNA was 34.1 kDa and consisted of 293 amino acid residues. The predicted amino acid sequence was 75.1-88.6% identical to those of EXGT genes in other plants. The Ps-EXGT1 cDNA was strongly expressed in elongating roots and stems but not in either mature stems or young leaves. In roots, the transcription level of Ps-EXGT1 was most abundant in the rapidly growing region. When root elongation was inhibited by a water stress, Ps-EXGT1 transcription was repressed. The roots curved hydrotropically due to differential growth of the cortical cells in the elongation zone when the root cap was exposed to a gradient of water potential; the length of the cells on the side of lower water potential was much longer than those on the side of higher water potential. The expression pattern of Ps-EXGT1 in the hydrotropically responding roots fluctuated between the side of the higher water potential and that of the lower water potential in the elongation zone. In other words, the accumulation of Ps-EXGT1 mRNA was much greater on the side of lower water potential than on that of higher potential just prior to the commencement of positive hydrotropism. When the roots started to curve slightly away from the side of higher water potential causing a rhythmic oscillatory movement [Takano et al. (1995) Planta 197: 410], there was more transcription of Ps-EXGT1 on the side of higher water potential. These results suggest that the transcription of Ps-EXGT1 is involved in cell growth and that this regulation of transcription plays a role in the differential growth of hydrotropically responding roots.

Amino Acid Sequence↗
PubMed1999

Expression of endoxyloglucan transferase genes in acaulis mutants of Arabidopsis.

A mutant of Arabidopsis with reduced internodal cell length, acaulis5 (acl5), has recently been shown to have reduced transcript levels of a gene for endoxyloglucan transferase, EXGT-A1 (Y. Hanzawa, T. Takahashi, Y. Komeda [1997] Plant J 12: 863-874). In the present study, we cloned genomic fragments of five members of the EXGT gene family, EXGT-A1, EXGT-A3, EXGT-A4, XTR2, and XTR3, and examined their expression in the wild type and in a series of acl mutants. In wild-type plants, the EXGT-A3 gene showed higher expression in lower internodes (internodes between nodes bearing axillary shoots) than in upper and young internodes, in which EXGT-A1 was highly expressed. EXGT-A4 was preferentially expressed in roots and XTR3 in siliques. The XTR2 gene was constitutively expressed. In acl1, acl3, and acl4 mutants, which have a severe defect in leaf expansion as well as in internode elongation, the EXGT-A1 gene showed reduced levels of expression before bolting of plants. In contrast, XTR3 was increased in these mutant seedlings. Reduction of EXGT-A1 expression was also detected after bolting of all acl mutants except acl2, whose growth defect is restricted to lower internodes. These results suggest the involvement of each EXGT in different aspects of organ development.

Arabidopsis↗
PubMed1999

Coronary artery stenosis evaluated by combined carotid and coronary angiography in patients undergoing carotid endarterectomy.

The relationship between coronary artery stenosis and the postoperative outcome was investigated in patients who underwent carotid endarterectomy (CEA). The benefit of combined carotid and coronary angiography was also evaluated. Combined carotid and coronary angiography was performed in 72 patients treated with CEA (mean age 64.0 years). Fourteen patients with a history of ischemic heart disease (IHD) had a higher Gensini score for coronary artery stenosis than patients with no history of IHD (37.9 +/- 36.8 vs. 7.9 +/- 12.5, p < 0.0001). However, 39.7% of patients with no history of IHD had a Gensini score exceeding 6. Patients with diabetes mellitus had a significantly higher Gensini score than nondiabetic patients. Eleven patients (15.3%) underwent percutaneous transluminal coronary angioplasty and three (4.2%) underwent coronary artery bypass grafting during the CEA perioperative period. None of the patients who underwent combined angiography showed signs of IHD during or after CEA (mean follow-up period 30 months). Combined angiography was not performed in 189 previous patients. Of these, two died of acute myocardial infarction in the postoperative period, 11 manifested nonfatal IHD, and 18 succumbed to IHD (mean follow-up period 8 years). Although patients with a history of IHD manifested more severe coronary artery stenosis than patients without such a history, the possibility of coronary artery stenosis must be considered in patients with no history of IHD, especially those with diabetes mellitus. Combined carotid and coronary angiography and careful management of coronary artery stenosis can be expected to decrease the mortality and morbidity in patients treated with CEA.

Adult↗
PubMed1998

Hyperperfusion syndrome following carotid endarterectomy: evaluation using diffusion-weighted magnetic resonance imaging--case report.

A 65-year-old female developed hyperperfusion syndrome following carotid endarterectomy for severe stenosis of the left internal carotid artery. Transcranial Doppler monitoring showed a sharp increase in flow velocity in the middle cerebral artery (MCA). Diffusion-weighted magnetic resonance (MR) imaging demonstrated diffuse hyperintensity in the region of the left MCA, which diminished markedly 9 days later. The abnormal hyperintensity decreased as the patient's symptoms improved, suggesting that diffusion-weighted MR imaging can be used for evaluating the course of hyperperfusion syndrome.

Aged↗
PubMed1998

[Effect of epidural pressure gradient on buprenorphine flux through the dural hole after combined spinal-epidural anesthesia--comparison between bolus injection and continuous infusion].

Combined spinal-epidural anesthesia is a useful technique. However, there has been no attempt to investigate the risk of epidural opioid, especially buprenorphine, flux through the dural hole. The purpose of this study was to compare the effect of epidural buprenorphine administered across the dura into subarachnoid space, between two different methods of administration; bolus injection (Group I) and continuous infusion (Group II). Sixty patients for transvaginal hysterectomy were divided into two groups. Group I received buprenorphine 0.1-0.2 mg with 0.25% bupivacaine, and Group II 0.4 mg with 0.25% bupivacaine 40 ml continuously (infusion rate was 1.7 ml.h-1). Pain relief was similar in both groups, but the total buprenorphine requirement was lower in Group I than in Group II. The incidence of nausea and vomiting was significantly higher in Group I than that in Group II, 73% and 16%, respectively. It indicates that the increase of nausea and vomiting is predominantly determined by a high rate of flux into subarachnoid space and only partly determined by blood concentrations. In contrast to continuous infusion, the drug movement through the dural hole may increase by bolus injection due to its higher pressure. We recommend careful injection of epidural buprenorphine such as by continuous infusion with low pressure after combined spinal-epidural anesthesia.

Adult↗
PubMed1998

[HELLP syndrome in triplet pregnancy complicated by DIC and transient diabetes insipidus].

A 29-year-old woman with a triplet pregnancy received emergency caesarean section in the 33rd week of pregnancy. She lost 2 babies, one of whom was a fetal death and the other a neonatal death. Three weeks before delivery, she was admitted to hospital suffering from vomiting, diarrhea and polyuria. There were no laboratory abnormalities such as a slightly elevated levels of liver enzymes, nor any clinical symptoms of preeclampsia. At the end of the operation, disseminated intravascular coagulation (DIC) occurred and HELLP syndrome was diagnosed. However, the hemoglobin level was in the normal range at this point. On the 2nd postoperative day, hemolytic anemia developed in spite of the resolution of other problems. We suggested that the hemolysis, which may have been caused by a latent hemoconcentration and a membrane disorder of the red cells, was an osmotic hemolysis. This case was unique for the following reasons; 1) a lack of symptoms of hypertension, proteinuria and edema, 2) complications due to diabetes insipidus, 3) postpartum severe hemolysis following latent hemoconcentration, and 4) slow progress of the condition after onset. Early detection of HELLP syndrome is difficult. It should be considered in the management of patients with unrecognizable hemoconcentration and nonspecific complications.

Adult↗
PubMed1997

The role of endoxyloglucan transferase in the organization of plant cell walls.

The plant cell wall plays a central role in morphogenesis as well as responsiveness to environmental signals. Xyloglucans are the principal component of the plant cell wall matrix and serve as cross-links between cellulose microfibrils to form the cellulose-xyloglucan framework. Endoxyloglucan transferase (EXGT), which was isolated and characterized in 1992, is an enzyme that mediates molecular grafting reaction between xyloglucan molecules. Structural studies on cDNAs encoding EXGT and its related proteins have disclosed the ubiquitous presence in the plant kingdom of a large multigene family of xyloglucan-related proteins (XRPs). Each XRP functions as either hydrolase or transferase acting on xyloglucans and is considered to be responsible for rearrangement of the cellulose-xyloglucan framework, the processes essential for the construction, modification, and degradation of plant cell walls. Different XRP genes exhibit potentially different expression profiles with respect to tissue specificity and responsiveness to hormonal and mechanical signals. The molecular approach to individual XRP genes will open a new path for exploring the controlling mechanisms by which the plant cell wall is constructed and reformed during plant growth and development.

Amino Acid Sequence↗
PubMed1997

[Management and long-term follow-up results in patients with carotid artery dissection].

The recognized incidence of extra- and intracranial carotid artery dissection has increased concomitantly with the progress and development of diagnostic methods. However, management for this condition is still controversial. We report in the present study the management and long-term follow-up results of 15 patients with carotid artery dissection. Mean age of the patients at onset was 47.8 years old, and male/female ratio was 12:3. Two patients were considered to be traumatic dissections and the other 13 patients were spontaneous dissections. Dissection occurred in 10 patients at the extracranial carotid artery, in 4 at the intracranial carotid artery and in 1 at the middle cerebral artery. Nine of 15 patients demonstrated hemiparesis and 5 complained of headache or facial pain. However, it was not possible to identify a characteristic symptom of dissection. Final diagnosis of dissection was made by cerebral angiography in all patients. Serial angiography was carried out in 10 of those, and 5 of the 10 patients showed some improvements of dissection in the cerebral angiogram. Treatment for those patients was selected according to the neurological and angiographical changes. Five patients were managed conservatively and 10 patients underwent surgical revascularization. During the follow-up period (mean 77.6 months), none of them showed any symptoms of reattack, and all but one, who died of heart failure 193 months after revascularization surgery, have lived independently. Although diagnosis of dissection was difficult because of the lack of characteristic symptom, serial angiography was a useful method for diagnosis and adequate management has led to a good clinical outcome.

Adolescent↗
PubMed1995

[On the antibacterial effect of hinokitiol against Staphylococcus aureus showing double zone phenomenon].

We studied the antibacterial effect of Hinokitiol against Staphylococcus aureus. As reference, we studied also the antibacterial effects of the oil and water from Thujopsis dolablata var. hondai Makino which contains Hinokitiol an important element of its antibacterial effect. Interestingly, Hinokitiol showed the double zone phenomenon, i.e., minimum inhibitory concentration of hinokitiol against MSSA was 15-125 micrograms/ml and against MSSA was 125 micrograms/ml. But when the concentration of Hinokitiol was diluted to 1.87-0.94 micrograms/ml, then the growth of MSSA was inhibited (Table 1 and Fig. 1). This phenomenon was observed the study on antibacterial effect using disk containing Hinokitiol (Fig/3). Similar phenomenon were observed also in the study using water from Thujopsis dolablata (Table 2 & Fig. 2). We deduce that Hinokitiol has a strong antibacterial effect against S. aureus. But this effect shows double zone effect. The antibacterial effect of Hinokitiol is more prominent against MRSA than MSSA.

Dose-Response Relationship, Drug↗
PubMed1995

[Usefulness of coronary angiography in patients undergoing carotid endarterectomy].

We evaluated 37 cases of coronary angiography in patients undergoing carotid endarterectomy (CEA). The severity of coronary stenosis was estimated by Gesini's scoring system. There was no correlation between the severity of carotid stenosis and that of coronary stenosis, but those patients who had a history of coronary artery disease, carotid bruit or intracranial artery stenoses presented significant severe coronary stenosis in most cases. Even in the patients who had no history of coronary artery disease (n = 26), 13 patients (50%) had stenotic lesions shown by coronary angiography. Eight patients required treatment for their coronary stenotic lesions: 5 were treated with percutaneous transluminal coronary angioplasty (PTCA) and 3 with coronary artery bypass grafting. Intraoperative occlusion tests monitored by EEG and SEP showed abnormal findings in 6 CEA operations. One of these patients received PTCA before CEA, and had a good clinical course during and after the CEA procedure. In conclusion, in patients undergoing CEA there is frequently concomitant coronary artery stenosis. We should thus assess the coronary artery lesion more precisely by coronary angiography, and should carry out prophylactic treatment for these lesions.

Aged↗
PubMed1995

[Treatment of tuberculous tracheobronchial stenoses with expandable metallic stent (EMS)s placed during percutaneous cardiopulmonary support (PCPS)].

A 63-year-old woman was taken to a hospital by ambulance because of dyspnea. She was admitted in nearly complete cardiopulmonary arrest. CPR was started immediately, and the patient was mechanically ventilated via a tracheostomy tube. Abnormally high airway pressures 40-50 cmH2O were required during positive pressure ventilation. Saber-sheath like stenoses of the lower trachea 3 cm long and left main stem bronchus 2 cm long were found by bronchoscopy. It was difficult to pass a 3-mm-diameter bronchoscope through these stenoses. The right main stem bronchus was completely obstructed. A chest radiograph showed a completely collapsed right lung and a scarred upper lobe of the left lung, probably caused by previous tuberculosis. Weaning from the ventilator was attempted over three months. However, the patient could not breathe by herself because of airway obstruction. She was referred to our hospital for the placement of stents into the stenotic parts of the airways. A longitudinally connected Gianturcotype EMS, 15 mm in diameter and 50 mm long was placed in each area of stenosis under general anesthesia. During the placement of EMSs, PCPS was used for 113 minutes instead of mechanical ventilation of the lungs. Hemodynamics were stable during PCPS. A bypass flow of 2.0-2.8 l/min/m2 was used. Oxygen saturation of arterial blood taken from an earlobe was maintained at 100%. Blood taken from the left radial artery had a PaO2 of 269.4 mmHg and a PaCO2 of 40.2 mmHg. There were no complications after the procedure. One month later, the stenoses had become slightly dilated.(ABSTRACT TRUNCATED AT 250 WORDS)

Bronchial Diseases↗
PubMed1994

[A case of idiopathic pulmonary fibrosis associated with bilateral pulmonary arterial thrombosis found at autopsy].

A 73-year-old woman admitted to the hospital with dyspnea on exertion. Chest radiography revealed a diffuse interstitial shadow; PaO2 was 72 Torr, and PaCO2 was 41 Torr. Laboratory examination results were compatible with idiopathic pulmonary fibrosis (IPF). Prednisolone relieved the dyspnea, but tapering of the drug led to a recurrence of this symptom. Pulse therapy was started and azathioprine was added to the corticosteroid. Over the course of 6 months of treatment, the patient's respiratory function remained fairly stable. Then respiratory distress was induced by an attack of atrial fibrillation, with relief provided by anti-arrhythmic drugs and large doses of corticosteroids. The patient died suddenly 3 weeks later. An autopsy revealed large thrombi in both pulmonary arteries with 90% stenosis. Parts of the thrombi were organized, which suggests that 2-3 weeks had elapsed since initial thrombus formation. Histological examination of lung tissue showed usual interstitial pneumonia. Pulmonary thromboembolism should be considered in patients with IPF if respiratory distress suddenly and unexpectedly worsens.

Aged↗
PubMed1993

Molecular cloning and cDNA sequencing of endoxyloglucan transferase, a novel class of glycosyltransferase that mediates molecular grafting between matrix polysaccharides in plant cell walls.

Endoxyloglucan transferase is a novel class of glycosyltransferase recently purified from Vigna angularis (Nishitani, K,, and Tominaga, R. (1992) J. Biol. Chem. 267, 21058-21064). This enzyme is the first transferase identified that catalyzes molecular grafting between polysaccharide cross-links in the cell wall matrix and participates in reconstruction of the network structure in the cell wall. Based on the NH2-terminal amino acid sequence information of the purified transferase, we have here cloned and sequenced cDNAs derived from five different plant species, V. angularis, Triticum aestivum, Arabidopsis thaliana, Lycopersicon esculentum, and Glycine max. In the five plant species, the amino acid sequence of the mature proteins is conserved in the range of 71-90% throughout their length. The consensus sequence for N-linked glycosylation, and four cysteine residues are all conserved in the five species. Thus, the endoxyloglucan transferase protein is ubiquitous among higher plants. The highly conserved DNA sequence will serve as a promising tool for exploring the molecular process by which cell wall construction, and hence cell growth, is regulated.

Amino Acid Sequence↗
PubMed1993

[Evaluation of CEA, SLX and CA125 in active pulmonary tuberculosis].

Serum tumor markers (CEA, SLX, CA125) were evaluated in 123 patients with active pulmonary tuberculosis. The results were as follows: Elevated serum CEA, SLX and CA125 levels were found in 16.9%, 39.5% and 44.4%, respectively, of patients with active pulmonary tuberculosis. Markedly elevated serum CA125 levels were found in some cases. On chest X-ray films, the factors associated with elevation of serum tumor marker levels were examined. Serum CEA and SLX levels were correlated with the extent of disease. Pleural effusion had no influence on serum tumor marker levels. Serum SLX levels were higher in patients without a tuberculous cavity than in those with a tuberculous cavity. After therapy with antituberculous drugs, the mean values of serum SLX and CA125 levels significantly decreased. The decrease in mean value of serum CEA levels was not significant, but in 4 of 8 cases, elevated serum CEA levels were normalized after therapy. On the other hand, two cases with increased serum CEA or SLX level died of respiratory failure. These results suggest that to follow up patients with elevated serum tumor markers is useful for the evaluation of disease activity of pulmonary tuberculosis. Further elevation of serum tumor marker levels after antituberculous therapy may indicate the presence of cancer or deterioration of the disease.

Adolescent↗