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Biomedical subjects

S Soeda

Publications and source records attributed to S Soeda.

At least 127 records · Page 7Linked to original sources

Distally based lateral plantar artery island flap.

We report on the reconstruction of the lateral metatarsal head defect by a distally based lateral plantar artery island flap using the flexor digitorum brevis muscle. The pedicle for this flap was provided by a retrograde lateral plantar artery. We found that this flap was relatively simple and easy to perform and could cover large defects better than any other conventional local flap.

Adult↗

The free or pedicled saphenous flap.

The saphenous flap described by Acland is a septocutaneous artery flap based on the saphenous vessels and great saphenous vein. The use of this flap in 2 patients who required soft tissue coverage is reported herein. The saphenous flap has the advantages of thin and pliable skin, a long and large pedicle, and the technical possibility of combination with the sartorius muscle, sensory nerve, and the femur or tibia. Donor defects are usually closed directly and cause no functional limitations. This flap is useful for the coverage of thin defects that require mobility, especially in the extremities or the intraoral region. It also could be used for the reconstruction of various types of organ losses (e.g., as a motor providing musculocutaneous flap, an osteocutaneous flap involving the femur or the tibia, and/or a vascularized nerve graft).

Aged↗

The free or pedicled anteromedial thigh flap.

The anteromedial thigh flap first described by Song is a septocutaneous artery flap based on the septocutaneous perforator originating from the lateral circumflex femoral vessels and long saphenous vein. The use of this flap for 3 patients who required soft tissue coverage is reported herein. The most important advantage of this flap is that it can be used not only as a skin flap but also as a vascularized fascia graft and fasciocutaneous free flap for the full-thickness defect of the abdominal wall and cranial region.

Abdominal Muscles↗

[An experimental study on conductive spinal cord action potentials evoked by direct stimulation of the spinal cord--pathway and source of conductive action potentials in the spinal cord].

The following experiments were carried out in adult cats to clarify the pathway and origin of the conductive spinal cord action potential evoked by dorsal epidural stimulation. (1) Comparison with the potential by surface stimulation of the spinal cord: Since waveforms, conduction velocity, and the relationships between the stimulation site and the change in threshold level were equal to those of surface stimulation, epidural stimulation and direct surface stimulation apparently induced the potential deriving from the same origin. (2) Recording of single fiber action potential: The mean conduction velocity of the dorsal column fiber was approximately 50 m/sec and that of the dorsolateral funiculus fiber was about 80 m/sec. 15-20% of potential N1 and 80-85% of potentials N2 and N3 were composed by the dorsal column fibers, whereas 80-85% of N1 and 15-20% of N2 and N3 were composed by the dorsolateral funiculus fibers.

Animals↗

Localization of the binding sites of porcine tissue-type plasminogen activator and plasminogen to heparin.

To localize the binding region of porcine tissue-type plasminogen activator (EC 3.4.21.31) (t-plasminogen activator) to heparin, functionally active A and B chains (molecular mass of each 33 kDa) were separated from the two-chain t-plasminogen activator after mild reduction and alkylation. The A chain bound to fibrin-Sepharose, but not to heparin-Sepharose. In contrast, the B chain showed amidase activity toward HD-Ile-Pro-Arg-p-nitroanilide (S-2288) and a high affinity for heparin-Sepharose, but no affinity for fibrin-Sepharose. Plasminogen activator activity of the B chain was stimulated by heparin (about 3-fold), but not by fibrin. On the other hand, the elastase digestion fragments of plasminogen, kringle 1-3 and kringle 4, had no affinity for a heparin-Sepharose column, whereas the other fragment, Val442-plasminogen, efficiently bound to the column and was eluted with 1.6 M KSCN-containing buffer. The stimulatory effect of fibrin on two-chain t-plasminogen activator-catalyzed Val442-plasminogen activation was clearly diminished by heparin. These results suggest that heparin can form a complex with both t-plasminogen activator and plasminogen molecules through their catalytic regions located in each B chain, and that the heparin connection between t-plasminogen activator and plasminogen may improve the plasminogen activation kinetics by making a situation in which t-plasminogen activator is easily approachable to plasminogen.

Animals↗

Some properties of tissue-type plasminogen activator reconstituted onto phospholipid and/or glycolipid vesicles.

Porcine heart tissue-type plasminogen activator (t-PA) was reconstituted onto large multilamellar liposomes with various lipid compositions and the kinetics of plasminogen activation by free or the reconstituted t-PA were studied. Negatively charged lipids, sulfatide and phosphatidylserine (PS), lowered the Km values of t-PA for plasminogen activation (sulfatide, 20-fold; PS, 6-fold), whereas neutral lipid phosphatidylcholine raised the Km. On the other hand, these lipid environments did not affect the amidase parameters and fibrin-binding potency of t-PA. The present results suggest that t-PA could function as a cell-associated form and its plasminogen activation may be regulated by the net charge of the head group of membrane lipids.

Animals↗

Is the sleeve anastomosis a risky technique?

We report 15 free flap transfers using sleeve vascular anastomoses with minor modifications of the original method. There was partial necrosis of one flap and one other required reoperation due to kinking of the feeding artery and not to the method of anastomosis. We believe that the sleeve anastomosis is reliable in clinical microvascular surgery if proper cases are selected. Indications for the method are discussed.

Adolescent↗

Surgical treatment of traumatic facial dimples.

Traumatic cheek dimples are commonly encountered following trauma. The majority resolve spontaneously with time. In some cases dimples persist, leaving a cosmetic deformity particularly noticeable with movements of facial expression. We propose an operative technique for such cases where symptoms persist for a year or more. Our operative methods and representative cases are described.

Adolescent↗

The free ulnar forearm flap.

Many flaps have been described based on the septocutaneous perforators; these have many advantages for the coverage of soft tissue defects. The ulnar forearm flap described by Lovie is a septocutaneous flap based on the septocutaneous perforators of the ulnar artery. We report the use of this flap in 2 patients who required soft tissue coverage. The ulnar forearm flap has the advantages of thin and pliable skin, constant and large pedicle, and the technical possibility of combination with the muscles, sensory or motor nerve, and ulna. Comparing it with the radial forearm flap, there is no possibility of exposure of flexor tendons, which usually results in the good take of skin grafts. After skin grafting, the donor scar is unnoticeable because of its position on the forearm. This flap is for the coverage of thin defects that require mobility, such as in the extremities or the intraoral region. It also could be used for the coverage of hand or arm defects as a distally or proximally based island flap, respectively.

Forearm↗

Closure of a palatal fistula by a free tongue composite graft.

Postpalatoplasty fistulas were closed by free tongue composite grafts. Based on this experience, sharply dissected, thin hinge flaps and the fixation of the grafts are considered the vital points. If carefully executed, this procedure is safe and produces good results in closing small fistulas of the hard palate. Operative procedures are described and 2 representative cases are discussed.

Adolescent↗

[A case of extraorbital sebaceous carcinoma].

A case of sebaceous carcinoma of the forehead of a 77-year-old male is reported and discussed and included in a review of all such cases reported in Japan. The patient had a round erosion on the right forehead that had caused itching for 15 months. An excisional biopsy of that lesion disclosed a malignancy and a subsequent wide excision was performed. The tumor recurred several times after excision and partially effective radiation therapy. The patient finally died of aspiration pneumonia 3 years after the first operation. An autopsy revealed that he had a recurrent sebaceous carcinoma extending to the periosteum of the right temporal bone and a solitary pulmonary metastasis.

Adenocarcinoma↗

Rapid and high-yield purification of porcine heart tissue-type plasminogen activator by heparin-sepharose choromatography.

A rapid and high-yield procedure for the purification of single polypeptide tissue-type plasminogen activator (t-PA) from porcine heart tissue has been developed. Delipidated heart tissue was extracted with 0.45 M potassium acetate. The extract was fractionated with ammonium sulfate and purified by a combination of affinity chromatography on heparin-Sepharose CL-6B and gel filtration on Toyopearl HW-55S. The final product had a specific activity of 220,000 IU/mg protein and gave a single protein band (apparent molecular weight; 67,000) in SDS-polyacrylamide gels in the presence or absence of a reducing agent. The increase in specific activity was 3,200-fold, most of which was achieved in the step of heparin-Sepharose chromatography. The yield calculated from the active ammonium sulfate precipitate was about 90% and 500 micrograms or more of the purified enzyme was obtained from 1 kg wet tissue. This procedure may also be useful for the large-scale production of highly purified t-PA from other tissues or tissue culture cells.

Amino Acids↗

Solubilization and partial characterization of fatty acyl-CoA:sphingosine acyltransferase (ceramide synthetase) from rat liver and brain.

Lignoceroyl-CoA:sphingosine lignoceroyltransferase, which catalyzes synthesis of lignoceroylsphingosine, the ceramide that is a major component of sphingolipids in mammalian tissues, has been solubilized from microsomes of rat brain and liver and partially purified. The microsomes were treated with 1 M sodium thiocyanate in N,N-bis(2-hydroxyethyl)glycine (Bicine) buffer containing 20% glycerol. The supernatant fraction obtained after centrifugation was fractionated by Sepharose CL-4B gel filtration. The ceramide synthetase activity was recovered in a small fraction containing high molecular weight proteins. Analysis of proteins and lipids indicated that the fraction was not simply a fragment of microsomes. The activity for synthesis of lignoceroylsphingosine, which is abundant in nervous system, was compared with that for the synthesis of stearoylsphingosine, which is more enriched in extraneural sphingolipids, in brain and liver microsomes. Despite the difference in relative abundance of molecular species of ceramides in these tissues, the activity for lignoceroylsphingosine synthesis was not more enriched in brain than in liver.

Acyl Coenzyme A↗

Change of substrate specificity of rat liver microsomal fatty acyl-CoA synthetase activity by Triton X-100.

The effect of Triton X-100 on the activities and apparent molecular size of fatty acyl-CoA synthetase, solubilized and partially purified from rat liver microsomes, was studied. In the presence of Triton X-100, the activity for lignoceroyl-CoA synthesis was decreased, but activity was restored when the detergent was removed. The appearance and disappearance of lignoceroyl-CoA synthesis appeared related to the size of the aggregated form of the enzyme. On the other hand, activity for palmitoyl-CoA synthesis was not significantly affected by the detergent. Because available evidence suggests that both fatty acids are converted to CoA esters by the same enzyme, it seems likely that the substrate specificity of the enzyme is influenced by changes in the aggregation state and that the microenvironment of the enzyme in membranes may determine the substrate specificity of acyl-CoA synthetase.

Animals↗

A radial forearm flap based on an extended dissection of the cephalic vein. The longest venous pedicle? Case report.

A radial forearm flap based on the cephalic vein was elevated to resurface a defect in the left auricular region. The cephalic vein was dissected up to the clavicle and the flap was transferred through a subcutaneous tunnel to the defect. The radial artery was anastomosed to the stump of the external carotid artery using a vein graft. The flap pursued an uneventful course and survived completely. This showed that the long venous pedicle (47 cm) could drain the flap safely and sufficiently.

Carcinoma, Squamous Cell↗

Surgical treatment of Stahl's ear using the periosteal string.

Surgical treatment of Stahl's ear is reported. Lifting of the cymba and bending of the helix by the periosteal string are the main points. This method is simple, and it is easy to adjust the extent of correction. Four patients were operated on by this method, and no complications were encountered. The results are quite satisfactory. In the follow-up periods (16 to 29 months, average 22.5 months), the operated ears retain their corrected forms and bear close resemblances to the opposite ears.

Child↗

Effects of polyamines on proline endopeptidase activity in rat brain.

The in vitro effects of polyamines on the activity of proline endopeptidase (PEPase) in rat brain cytosol, which contains an endogenous PEPase inhibitor, have been studied. Of the three amines tested (spermine, spermidine, and putrescine), spermine and spermidine markedly enhanced the enzyme activity in brain cytosol. At 6.25 mM spermine or 25 mM spermidine, a 13- or 14-fold enhancement of the enzyme activity was observed. When Mg2+ was used, an approximately fourfold enhancement of the enzyme activity was observed at 50 mM. The enhancement produced by spermine or spermidine was unaffected by Mg2+ up to 50 mM. The activity of purified PEPase was only slightly affected by each polyamine, but it was inhibited 50% by 50 mM Mg2+. On the other hand, 50% inhibition of the enzyme produced by the purified PEPase inhibitor (Mr 7,000: Ki 0.67 mM) was completely restored by addition of 0.7 mM spermine, 3.5 mM spermidine, or 28 mM putrescine. This restoration of inhibition by polyamines was reversed by increasing the inhibitor concentration. These data suggest that polyamines effectively reverse the inhibition of PEPase by its endogenous inhibitor by the reversible formation of a kinetically significant complex. The possible functions of polyamines in the regulation of PEPase in vivo are discussed.

Animals↗