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Biomedical subjects

K Okabayashi

Publications and source records attributed to K Okabayashi.

99 records · Page 6Linked to original sources
PubMed1979

Partial purification and properties of citrate synthase from sea urchin eggs.

Citrate synthase [EC 4.1.3.7] was purified from sea urchin eggs about 14-fold with a 23% yield, based on the activity of the crude extract. The molecular weight of the enzyme was about 100,000 as determined by gel filtration. The optimum pH was about 7.8 in 100 mM Tris-HCl. The apparent Km values for acetyl-CoA and for oxaloacetate were 33 and 3.2 muM, respectively. Monovalent and divalent cations inhibited the enzyme. Iodoacetamide, pCMB, EDTA, NaF, and dithiothreitol did not affect the enzyme activity. Oxaloacetate protected the enzyme against heat denaturation. Among nucleotides, ATP was the most potent inhibitor of the enzyme. The inhibition by ATP was competitive with respect to acetyl-CoA and mixed with respect to oxaloacetate.

Animals↗
PubMed1974

Surface-bound nuclease of Stapylococcus aureus: purification and properties of the enzymes.

The surface-bound nuclease of Staphylococcus aureus liberated during formation of protoplasts was purified 1,000-fold by chromatography on phosphocellulose. Its properties were compared with those of the known extracellular nuclease, purified 200-fold by the same procedures. The adsorbance of the surface-bound nuclease on phosphocellulose was distinctly different from that of the extracellular nuclease, but other properties of the two enzymes were similar. Both enzymes had a pH optimum of about 10 and required Ca(2+) for activity. Both enzymes hydrolyzed deoxyribonucleic acid (DNA) and ribonucleic acid, and denatured DNA was a better substrate than native DNA. Both enzymes were inhibited by the same metal ions. Nuclease-less mutants of S. aureus were isolated from S. aureus 209P by using N-methyl-N'-nitroso-N-nitrosoguanidine. These mutants contained neither surface-bound nor extracellular nuclease activity. These results suggest that the surface-bound and extracellular nucleases are expressed from the same cistron of S. aureus.

Ammonium Sulfate↗
PubMedDate not supplied

Recurrence after thoracoscopic surgery for spontaneous pneumothorax.

AIM: The purpose of this study was to examine the cause and risk of recurrence after thoracoscopic surgery for spontaneous pneumothorax. METHODS: A total of 204 patients under 60 years of age who underwent axillary thoracotomy and 139 patients who underwent thoracoscopic surgery were compared. In addition, among the patients who underwent thoracoscopic surgery, recurrent and non recurrent cases were reviewed and compared. RESULTS: Postoperative recurrence rate was significantly higher among the thoracoscopic surgery group. There were some significant differences between the recurrent and non recurrent cases in the Brinkman index, the duration from the onset of pneumothorax to the initial consultation, and the number of patients who had past history of pneumothorax. The recurrence rate was higher in patients with an air leak in the chest drainage tube before operation than in patients without an air leak. CONCLUSIONS: Appropriate training under supervision of experienced surgeons is necessary for minimizing complications and procedure failures. A history of heavy smoking or an air leak in the chest drainage tube before surgery may be an index of recurrence after surgery.

Adult↗
PubMedDate not supplied

The role of video-assisted thoracic surgery for the treatment of lung cancer: lung lobectomy by thoracoscopy versus the standard thoracotomy approach.

Our objective was to evaluate the usefulness, safety, validity and benefits of video-assisted thoracoscopic surgery (VATS) for performing pulmonary lobectomy in 24 patients with clinical NO stage I primary non-small-cell lung cancer compared with 30 patients who underwent a conventional thoracotomy. There were no significant differences in the intra-operative blood loss, duration of operation, or duration of chest tube drainage between the VATS group and the standard lobectomy group, but in this VATS' experience, patients had less postoperative pain. Numbers and distributions of dissected lymph-nodes were similar in patients whether undergoing standard thoracotomy or VATS lobectomy. We can confirm that the safety and validity of VATS are virtually identical to those of the standard thoracotomy approach in the lobectomy. However, the former technique causes less discomfort to patients and requires a shorter recovery period of laboratory data and IL-6 concentrations in thoracic drainage fluid. We conclude that VATS major lung resection is technically feasible. Stringent patient selection is important and special training is needed.

Aged↗
PubMedDate not supplied

Plasmapheresis in familial hypercholesterolemia.

Twelve years' experience confirms that plasma exchange beneficially influences the course of homozygous familial hypercholesterolemia. Pilot studies with low density lipoprotein (LDL) apheresis using a dextran sulphate affinity column suggest that this procedure has advantages over plasma exchange, which it may eventually replace. Combination therapy with lovastatin and LDL apheresis is currently being assessed as a means of inducing regression of coronary lesions. Preliminary results of a pilot study in four patients with heterozygous familial hypercholesterolemia are encouraging.

Blood Component Removal↗