Fluorescence energy transfer between epsilon-ATP at the nucleotide binding site and N-(4-dimethylamino-3,5-dinitrophenyl)-maleimide at Cys-373 of G-actin

The method of fluorescence energy transfer is used to measure the distance from the nucleotide binding site to Cys-373 of G-actin. The fluorescent ATP analogue 1-N6-ethenoadenosine 5'-triphosphate was used as donor and N-(4-dimethylamino-3,5-dinitrophenyl)-maleimide was used as acceptor. From the measurements of the efficiency of fluorescence energy transfer by both static and time resolved fluorometries, the distance between nucleotide binding site and Cys-373 residue of G-actin was calculated to be about 30 A.

Operative nephroscopy with fiberoptic scope: preliminary report

New fiberoptic scopes, originally designed for biliary tract operations, were used in 23 cases for removal of residual calculi at pyelolithotomy and for examination of the renal pelvis and ureter. The external diameters of the scopes are 6.6 mm. (CHF-X1) and 4.5 mm. (CHF-X2). Water irrigation and forceps manipulation can be performed simultaneously with the CHF-X1 scope but only irrigation can be done with the CHF-X2 scope. The scopes were reliable and allowed easy endoscopic forceps manipulation. Improvements for an ideal fibroptic nephroscope are discussed.

Long-term results of retinal detachment surgery

Patients treated successfully with retinal detachment surgery 11-39 years earlier were called back and examined. The average age was 35 years at the time of surgery and the average interval between the operation and this follow-up examination was 16 years. The visual acuity had decreased in many patients. The most frequent causes of this fall in visual acuity after surgery were cataract and macular degeneration. Chorioretinal atrophy with blackish pigment spots developed in the reattached retina a long time after surgery and caused defects in the visual fields. This atrophy seems to be related to the long duration of retinal detachment before and after operation, which may cause malnutrition of the detached retina and result in incomplete recovery of visual cells, leading to chorioretinal atrophy. Macular degeneration was caused or accelerated by detachment of the macula. There was no difference in postoperative ocular findings between only diathermy and combination of diathermy with segmental scleral-buckling procedures. However, Arruga's ring suture method induced cataract more frequently than did other surgical procedures.

Basic studies of various 99mTc-labelled renal agents and clinical application of 99mTc-malate

Various renal imaging agents that were reported in the past and a new agent, 99mTc-malate as well as99mTc-cystein acetazolamide complex were prepared using electrolysis and electrochemical methods. These were studied for their labelling efficiency. After animal experiments with selected 99mTc-compounds, 99mTc-malate proved to be sufficient for renal imaging with adequate concentration. 99mTc-malate differs from other renal imaging agents in the utilization of endogeneous metabolic product. The first half time of 99mTc-malate in humans is 17 minutes, on the average, and the urinary excretion rate of 99mTc-malate is 36+/-6.05% in 1 hour after intravenous administration, 44+/-3.41% in 2 hours and 50+/-5.62% in 3 hours. In our 40 clinical experiences of 99m-Tc-malate, most cases demonstrated quite clear renal images in the serial scintiphotos except cases whose serum creatinines were over 4.5 mg/dl.

Fluorescence and flow dichroism of F-actin-epsilon-ADP; the orientation of the admine plane relative to the long axis of F-actin

The excitation polarization spectrum of epsilon-ADP bound to F-actin shows that two absorption dipoles at 260 nm and 340 nm are oriented in different directions relative to the emission dipole. On the other hand, the linear dichroism of F-actin-epsilon-ADP gives that the dichroic ratio of the bound epsilon-ADP is approximately constant (about-0.5) in the wavelength region form 250 to 350nm. Furthermore, the fluorescence polarization of epsilon-ADP bound to F-actin which is oriented in the field of flow shows that the emission dipole is nearly perpendicular to the long axis of F-actin. From these observations we conclude that the adenine plane of the bound nucleotide is almost perpendicular to the long axis of F-actin.

Evaluation of recommended methods for radioisotopes red cell survival studies

Mean red cell life-span in normal subjects and in patients with various hematological disorders was examined with 51Cr and DF32P. The results with 51Cr were corrected for 51Cr elution using correction factors. The results by the two methods agreed fairly well with each other. Elution rate in various hematological disorders was 2.3% per day or less except for the patients with extracorpuscular hemolytic agents such as autoimmune hemolytic anemia or congestive splenomegaly. It is concluded that estimates of mean red cell life-span by corrected 51Cr method are more useful and sufficient than uncorrected 51Cr or DF32P method in general hematological disorders.