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Biomedical subjects

H Mohri

Publications and source records attributed to H Mohri.

At least 325 records · Page 18Linked to original sources

Surgical treatment for hypoplastic left heart syndrome: case reports.

A 58-day-old girl with hypoplastic left heart syndrome underwent bypass grafting from the pulmonary artery to the descending aorta, ligation of the ductus arteriosus, and banding of the main pulmonary artery distal to the graft. Anastomoses of the graft were performed by partial clamping of the arteries under moderate surface hypothermia. The patient tolerated the procedure well and was discharged from the intensive care unit on the eleventh postoperative day, but she died on the twentieth day of metabolic derangement. Our total experience with this anomaly includes three other infants, and a summary of these patients and applied surgical procedures are presented. Surgical and diagnostic considerations for this anomaly based on our experiences are discussed.

Aorta, Thoracic↗

Use of athrombogenic tubing for perfusion rewarming following surface-induced deep hypothermia.

A method of heparinless, oxygenatorless, left heart bypass perfusion rewarming following surface hypothermia, with the use of a closed circuit with 130 ml. prime volume including heat exchanger, has been devised. The use of polyurethane-polyvinyl-graphite (PPG)-coated tubing has previously been reported. In this text, the use of an athrombogenic coating with cetyl-pyridinium chloride (CPC) as a regional heparin carrier was studied in dogs, comparing groups with PPG tubing and total systemic heparinization or plain polyvinyl tubing without systemic heparinization. Heparin compounded in the CPC coating eluted into the blood and caused mild transient whole-body heparinization during rewarming from 20 degrees to 25 degrees C., as evidenced by prolongation of the thrombin time. Alterations of hematologic parameters in all three groups were similar to those during surface rewarming except for those affected by heparinization. The left heart bypass method was found useful for hypothermic open-heart surgery when utilized with an athrombogenic surface coating or total body heparinization. It was concluded that the CPC coating is superior to the PPG coating since no cracking surface develops, it is translucent, and it provides a more effective athrombogenic surface.

Animals↗

Mode of action of alpha-chlorohydrin as a male anti-fertility agent. Inhibition of the metabolism of ram spermatozoa by alpha-chlorohydrin and location of block in glycolysis.

1. The effect of alpha-chlorohydrin on the metabolism of glycolytic and tricarboxylate-cycle substrates by ram spermatozoa was investigated. The utilization and oxidation of fructose and triose phosphate were much more sensitive to inhibition by alpha-chlorohydrin (0.1-1.0mm) than lactate or pyruvate. Inhibition of glycolysis by alpha-chlorohydrin is concluded to be between triose phosphate and pyruvate formation. Oxidation of glycerol was not as severely inhibited as that of the triose phosphate. This unexpected finding can be explained in terms of competition between glycerol and alpha-chlorohydrin. A second, much less sensitive site, of alpha-chlorohydrin inhibition appears to be associated with production of acetyl-CoA from exogenous and endogenous fatty acids. 2. Measurement of the glycolytic intermediates after incubation of spermatozoal suspensions with 15mm-fructose in the presence of 3mm-alpha-chlorohydrin showed a ;block' in the conversion of glyceraldehyde 3-phosphate into 3-phosphoglycerate. alpha-Chlorohydrin also caused conversion of most of the ATP in spermatozoa into AMP. After incubation with 3mm-alpha-chlorohydrin, glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase activities were decreased by approx. 90% and 80% respectively, and in some experiments aldolase was also inhibited. Other glycolytic enzymes were not affected by a low concentration (0.3mm) of alpha-chlorohydrin. Loss of motility of spermatozoa paralleled the decrease in glyceraldehyde 3-phosphate dehydrogenase activity. alpha-Chlorohydrin, however, did not inhibit glyceraldehyde 3-phosphate dehydrogenase or triose phosphate isomerase in sonicated enzyme preparations when added to the assay cuvette. 3. Measurement of intermediates and glycolytic enzymes in ejaculated spermatozoa before, during and after injection of rams with alpha-chlorohydrin (25mg/kg body wt.) confirmed a severe block in glycolysis in vivo at the site of triose phosphate conversion into 3-phosphoglycerate within 24h of the first injection. Glyceraldehyde 3-phosphate dehydrogenase activity was no longer detectable and both aldolase and triose phosphate isomerase were severely inhibited. Spermatozoal ATP decreased by 92% at this time, being quantitatively converted into AMP. At 1 month after injection of alpha-chlorohydrin glycolytic intermediate concentrations returned to normal in the spermatozoa but ATP was still only 38% of the pre-injection concentration. Motility of spermatozoa was, however, as good as during the pre-injection period. The activity of the inhibited enzymes also returned to normal during the recovery period and 26 days after injection were close to pre-injection values. 4. An unknown metabolic product of alpha-chlorohydrin is suggested to inhibit glyceraldehyde 3-phosphate dehydrogenase and triose phosphate isomerase of spermatozoa. This results in a lower ATP content, motility and fertility of the spermatozoa. Glycidol was shown not to be an active intermediate of alpha-chlorohydrin in vitro.

Animals↗

Surgical treatment of annuloaortic estasia: experience in 7 consecutive patients.

Seven patients with annuloaortic ectasia were treated according to the method described by Bentall and De Bono. A Björk-Shiley valve in a composite graft was the prosthesis of choice and was used in all patients except 1, who received a Starr-Edwards valve. Profound topical cooling without selective coronary perfusion was applied in 5 patients for myocardial preservation during aortic occlusion. The was 1 operative death and 1 late death, the latter from cerebral thromboembolism. Five survivors have been followed from 1 year 5 months to 2 years 10 months with an average follow-up of 2 years. Excellent results were obtained in all survivors, their physical capabilities putting them in Class I of the New York Heart Association Functional Classification. Postoperative aortograms showed no signs of kinking or compression of vascular prostheses nor abnormalities of prosthetic calves. A modified technique to secure graft fixation is discussed.

Adolescent↗

Microtubules in protozoan cells. III. Ultrastructural changes during disintegration and reformation of heliozoan microtubules.

In the heliozoan, Echinosphaerium nucleofilum strain MA, cold temperature (2 degrees C) induced axopodial retraction to about 36% of the initial length after 3 h. By electron microscopy, it was found that such axopodial shortening is accompanied by degradation of axonemal microtubules (25 nm in diameter), followed by the appearance of macrotubles (37 nm in diameter) and filamentous structures (14 nm in diameter) of a tubular and twisted appearance. All of these structures (microtubules, macrotubules and filamentous structures) were found to be depolymerized completely by applying 10 mM colchicine for 1-2 h, and to be replaced by regions with low electron density. Axopodial re-extension was induced rapidly by returning the cold-treated organisms to room temperature (20 degrees C). At a very early stage of axopodial re-extension, the filamentous structures were often observed to be continuous with the macrotubules. At a late stage of axopodial re-extension, the reforming axoneme was composed only of normal microtubules, while the macrotubules and filamentous structures had disappeared. On the basis of these results, the processes of disintegration and reformation of microtubules are discussed.

Animals↗

Oxygen consumption during surface-induced deep hypothermia under halothane anesthesia.

The effect of halothane-100% oxygen anesthesia on oxygen consumption was studied in 10 dogs subjected to surface-induced deep hypothermia with 30 minutes of circulatory arrest. The results were compared with previous oxygen consumtion data under ether-100% oxygen anesthesia. Low cardiac output, especially during the rewarming period, low PaO2, and a large arteriovenous oxygen difference during rewarming were significantly different in the halothane group, despite identical oxygen consumption in both groups. These differences could not elucidate the exact cause of postoperative motor disturbances associated with 30 minutes of circulatory arrest in the halothane group. The possibility that there was higher oxygen consumption under halothane anesthesia is discussed.

Anesthesia↗

Prefabricated Dacron baffle for use in correction of transposition of the great arteries.

Interatrial venous transposition for correction of transposition of the great arteries (TGA) is facilitated by using a premolded Dacron baffle. Fine-mesh Dacron is easily fashioned to the desired shape in a metallic brass mold at 200 degrees C. The resultant baffle material can be autoclaved without losing its shape or altering the fabric characteristics of flexibility and porosity. This premolded baffle has been used in our last 7 patients with TGA over the past two years without complication, and the use of Dacron in 13 survivors over the past seven years has shown no pulmonary or venous obstructions related to the material.

Humans↗

Identification of dynein as the outer arms of sea urchin sperm axonemes.

The location of dynein, the main flagellar ATPase, within the sea urchin sperm axoneme was investigated by the use of immunofluorescence and immunoelectron microscopy, employing an antiserum against a tryptic fragment of dynein 1 (Fragment 1A) purified from sea urchin sperm flagella. The axonemes were found to be stained with the antiserum when examined by an indirect immunofluorescence technique. Immunoelectron microscopy with the antiserum and a ferritin-conjugated IgG fraction of goat antiserum to rabbit IgG revealed that, among the structures within the axoneme, only the outer arms were labeled with ferritin particles. With either the normal serum or antiserum absorbed with Fragment 1A, there were no ferritin particles within the axonemes. When the outer arms were extracted with 0.5 M NaCl, leaving the inner arms intact, again no ferritin dots were detected. Furthermore, it was found that the outer arm on the no. 5 doublet microtubule, which connects with the extra arm projection backward from the no. 6 doublet, had no attached ferritin particles. From these observations, it can be concluded that the outer arm consists of dynein (at least dynein 1) and that Fragment 1A, containing the active site for ATPase activity of dynein 1, is located at the distal end of the outer arms. The significance of the present findings is considered in connection with flagellar movement.

Adenosine Triphosphatases↗

Surgical correction in infancy to reduce mortality in transposition of the great arteries.

The mortality for infants with transposition of the great arteries (TGA) prior to the introduction of medical and surgical septostomy was over 80% by 6 months of age. The mortality has fallen recently, due to balloon atrial septostomy (BAS), but still exceeds 25% by 6 months of age in major centers. The cumulative mortality rises to 40% by 1 year of age with or without additional surgical atrial septectomy. In our center, 12 patients with an average age of 3 months were operated on for interatrial baffle correction of their TGA under surface-induced deep hypothermia. BAS had been done preliminarily in those patients without an adequate atrial communication. Ten of these 12 patients (83%) survived. These patients have been followed up from one month to eight years with an average follow-up of over four years. Surgical correction during infancy offers a better survival rate for infants with TGA than does medical management, with or without palliative surgery.

Ductus Arteriosus, Patent↗