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Biomedical subjects

N Kotani

Publications and source records attributed to N Kotani.

At least 55 records · Page 3Linked to original sources
PubMed1991

Amino acid sequence of the 14-kDa protein in the photosystem I reaction center complex from Synechococcus elongatus Naegeli.

One of the small components (14 kDa) of the photosystem I reaction center complex was isolated from a thermophilic alga, Synechococcus elongatus. The amino acid sequence was determined. The protein consists of 137 amino acid residues, corresponding to the molecular mass of 15,319. Alignment of this sequence with the ferredoxin-binding proteins of photosystem I from other cyanobacteria and higher plants suggests the possible biologically important residues and the residues responsible for thermostability in the sequence.

Amino Acid Sequence↗
PubMed1991

Amino acid sequence of 10-kDa protein in photosystem I reaction-center complex from a thermophilic cyanobacterium, Synechococcus elongatus Naegeli.

Four small subunits (14, 13, 10, and 8 kDa) of the photosystem I reaction-center complex were isolated from a thermophilic cyanobacterium Synechococcus elongatus. The complete amino acid sequence of the 10-kDa subunit was determined to consist of 80 amino acid residues giving a molecular mass of 8855.3, excluding iron and sulfur atoms, and containing two special sequences of cysteine residues, Cys-X-X-Cys-X-X-Cys-X-X-X-Cys-Pro, at residues 10-21 and 47-58, which indicates that the subunit is an apoprotein carrying two iron-sulfur centers, FA and FB, assigned as [4Fe-4S] clusters. The amino acid sequence indicated an 87.5% identity compared with those deduced from the nucleotide sequences of chloroplast gene psa C from several plants.

Amino Acid Sequence↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--3. Pharmacokinetics during prolonged continuous ketamine infusion].

A simple and precise method has been developed for the analysis of plasma ketamine and its metabolites using gas chromatography with flame ionization detection after elution by trifluoroacetic dehydride. Seven surgical patients who received total intravenous anesthesia with droperidol, fentanyl and ketamine anesthesia over 5 hours were the subjects of the study. During the anesthesia, ketamine levels were from 1.0 to 2.0 micrograms.ml-1. After the termination of ketamine infusion, their levels decreased gradually. Metabolites I levels were elevated gradually to about twofold of that of ketamine and remained high. Metabolite II was detected in only two patients and their levels were under 0.2 micrograms.ml-1. The results of our study suggest that this type of anesthesia of prolonged duration is safe as judged by the present pharmacokinetic study.

Adult↗
PubMed1991

[A clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--2. Pharmacokinetics following the end of continuous ketamine infusion].

Ten surgical patients who received various operative procedures including abdominal surgery and ENT surgery were the subjects of the pharmacokinetic study of total intravenous anesthesia with droperidol, fentanyl and ketamine. Six arterial samples were taken through an indwelling catheter in the left radial artery to measure plasma levels of ketamine and its metabolites by means of gas liquid chromatography. Two hours following the end of the ketamine infusion, plasma ketamine levels decreased to 14% of the control value (0.81 micrograms.ml-1), while metabolite I (K1) was still about 1.8 micrograms.ml-1 in the plasma. The control value of plasma ketamine just before the end of its infusion had not any significant relationship with the total dose of ketamine, total dose of fentanyl, blood loss or fluid given. The results of our study suggest that long continuous ketamine infusion would be safe as judged by its pharmacokinetics.

Adult↗
PubMed1991

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--4. Control of intraoperative hypertension with nicardipine].

Intraoperative hypertension over 160 mmHg systolic observed during total intravenous anesthesia with droperidol, fentanyl and ketamine was treated with intravenous nicardipine in 50 surgical patients. Nicardipine was given intravenously in a bolus of either 0.5 mg or 1.0 mg to treat the intraoperative hypertension. Systolic and diastolic blood pressures decreased soon after administration of nicardipine without simultaneous sinus tachycardia. Thus rate pressure product was also reduced significantly. Neither preoperative hypertension, nor systolic blood pressure just before the administration of nicardipine had any significant relationship with hypotensive effect of intravenous nicardipine. We did not experience any adverse reaction with the drug. We conclude that intravenous nicardipine in a dose of 0.5-1.0mg can be given repeatedly to overcome hypertension observed during this method of anesthesia.

Adolescent↗
PubMed1990

Mutagenic activity of pyrolysates of cyanocobalamin and some other water-soluble vitamins in the model system with the Salmonella/mammalian microsomes.

Pyrolysates of cyanocobalamin, thiamine hydrochloride, riboflavin, pyridoxine hydrochloride, and ascorbic acid were tested for mutagenicity in the histidine-requiring mutants Salmonella typhimurium TA98 and TA100. Each vitamin was sealed in a glass tube and heated at 100-600 degrees C in a muffle furnace. Methanol-chloroform extracts of the pyrolysate of each vitamin tested did not show any mutagenicity in either TA98 or TA100 without rat liver 9000 x g supernatant fraction (S9) added. In the presence of S9, the B-group vitamins (cyanocobalamin, thiamine hydrochloride, riboflavin, and pyridoxine hydrochloride) were all mutagenic in TA98 and TA100, with the highest activity among the vitamins tested found in the pyrolysate of cyanocobalamin. The pyrolysate of 0.25 mumole cyanocobalamin produced 3200 revertants, while the pyrolysates of 0.25 mumole thiamine hydrochloride and riboflavin produced only 910 revertants, and the pyrolysate of pyridoxine hydrochloride did not show any mutagenicity at that amount. The mutagenicity was generally more active to TA98 than to TA100, indicating that frameshift-type mutagens were contained in the pyrolysates. The pyrolysate of ascorbic acid did not show any mutagenic activity in either TA98 or TA100 under the present experimental conditions.

Animals↗
PubMed1990

N-terminal amino acid sequence analysis of small subunits of photosystem I reaction center complex from a thermophilic cyanobacterium, Synechococcus elongatus Nägeli.

Four small subunits (14, 13, 10, and 8 kDa) of the photosystem I reaction center complex were isolated from a thermophilic cyanobacterium Synechococcus elongatus and their N-terminal amino acid sequences determined. Sequence analysis of the 10-kDa subunit revealed that the distribution of cysteine residues, Cys-X-X-Cys-X-X-Cys-X-X-X-Cys-Pro, is characteristic of bacterial-type ferredoxins, and that its partial sequence is highly homologous to that deduced from the chloroplast gene frx A of liverwort. This indicates that the 10-kDa polypeptide is an apoprotein carrying two iron-sulfur centers, FA and FB, assigned as [4Fe-4S] clusters, which mediated the light-activated transfer of electrons from P700 in photosystem I reaction center complex to soluble ferredoxin. The amino acid sequence of the 14-kDa polypeptide also showed similarity to that of the 20-kDa polypeptide from spinach chloroplast that can be chemically crosslinked with soluble ferredoxin. Thus, the 14-kDa polypeptide appears to be the ferredoxin 'docking' protein.

Amino Acid Sequence↗
PubMed1990

[Marked changes in the core temperature during anaphylactic shock].

Three cases of anaphylactic shock were reported in which the core temperature was measured continuously. Two core temperature thermister probes were fixed on the forehead and the sole. Temperature dissociation between the core and the periphery disappeared in a few minutes after the administration of the causative agents. The clinical signs of the anaphylactic shock such as erythema, wheal and marked hypotension also developed in a few minutes after the disappearance of temperature dissociation. Thus treatment of anaphylactic shock could be started even before the patients develop severe hypotension. This clinical study suggests that a sudden disappearance of the temperature dissociation is a incipient sign of anaphylactic shock and to monitor the core as well as the peripheral temperature is a useful method for early diagnosis and treatment of anaphylactic shock.

Aged↗
PubMed1990

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--1. Introduction].

We have developed a new method of total intravenous anesthesia with droperidol, fentanyl and ketamine and have administered it to more than 400 surgical patients, ranging in ages from 4 to 80 years. Cardiac and neurosurgical patients were excluded. After establishing a routine monitoring, droperidol 0.06-0.1 ml.kg-1 was slowly given. After 5 minutes, fentanyl 1-2 micrograms.kg-1 and ketamine 1.0-1.5 mg.kg-1 were slowly administered intravenously. Trachea was intubated following intravenous succinylcholine. A total dose of 5-15 micrograms.kg-1 of fentanyl was given intravenously with a continuous infusion of ketamine 2 mg.kg-1.hr-1 during surgical procedure. Air and O2 (FIO2 0.30-0.35) were given and muscle relaxation was achieved with necessary dose of intravenous pancuronium or vecuronium and no inhaled anesthetic was given. Total intravenous anesthesia has many advantages such as no air pollution in the operating theatre, empty bowels, no organ (hepato-renal) toxicity, good peripheral perfusion and low cost, while this method has several disadvantages to overcome such as hypertension. There are many anesthetic agents for total intravenous anesthesia. However, sufentanil, alfentanil and propofol are not available. Droperidol, fentanyl and ketamine are the best combination for this purpose in Japan so far.

Adolescent↗
PubMed1990

[Anesthetic experience of a patient with essential thrombocythemia].

We reported a 54-year-old male with essential thrombocythemia, who underwent coronary artery bypass grafting. Anesthesia was maintained with enflurane in nitrous oxide and oxygen supplemented with fentanyl. Heparin 7mg. kg-1 was administered intravenously to obtain adequate anticoagulant effect during 89 minutes of extracorporeal circulation. Aspirin and dipyridamole were also administered as anti-platelet therapy. No complications were observed during and after anesthesia. It is advocated that administration of anticoagulants such as heparin, aspirin and dipyridamole is effective to prevent thrombus formation.

Anesthesia, Inhalation↗
PubMed1989

[Prolonged respiratory depression following general anesthesia in a patient with dystrophia myotonica].

A case of general anesthesia for a 52 year old female with previously undiagnosed dystrophia myotonica was reported. The patient was diagnosed as flaccid paralysis of the bilateral lower extremities but myotonic symptoms were not found preoperatively. The patient underwent duodenal resection to have a benign tumor removed. Anesthesia was induced with thiamylal 250 mg and pancuronium bromide 4 mg intravenously to facilitate tracheal intubation. Anesthesia was maintained with enflurane (0.6-1.0%) in nitrous oxide (50%) and oxygen (50%). The course of anesthesia was uneventful except for a transient hypotension of 80 mmHg systolic for about 10 minutes. The patient did not recover smoothly from anesthesia and prolonged apnea was observed. 90 minutes after the end of surgical procedure, spontaneous ventilation appeared. Then the tidal volume increased gradually but it still remained around 100-150 ml even 3 hours after the end of the operation. She was on ventilator and observed carefully. The endotracheal tube was removed four days after the operation. The patient was examined again by a neurologist and a final diagnosis of dystrophia myotonica was made. Prolonged recovery from anesthesia and postoperative respiratory depression observed in this patient was due to preoperatively undiagnosed dystrophia myotonica. A careful preoperative examination should be made to minimize possible complication related to anesthesia in the disease.

Anesthesia Recovery Period↗
PubMed1989

Amino acid sequences of ferredoxins from rice cultivars, japonica and indica.

Ferredoxins were isolated from the leaves of two rice cultivars, japonica and indica. The purified protein preparations each contained two components, the major (I) and the minor (II) ferredoxin. Ferredoxin I from each cultivars was sequenced. The amino acid sequences of the ferredoxin I from the two strains were found to be identical to each other. The sequence similarity with wheat ferredoxin is about 90%. Most of the amino acid alterations are located at the ends of the protein, with the sequences surrounding the iron-sulfur coordinating cysteine residues being well conserved.

Amino Acid Sequence↗