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Biomedical subjects

H Yajima

Publications and source records attributed to H Yajima.

At least 91 records · Page 5Linked to original sources
PubMed1996

Free and island flap transfer for soft tissue defects in the hand and forearm.

Two hundred twenty patients with soft tissue defects in the hand and forearm were treated with 226 free and island flap transfers. Reconstructed sites involved the thumb in 74 cases, the fingers in 117, the hand in 30, and the forearm in 5. Seventy-nine patients received 82 free flaps, and 141 patients received 144 island flaps. Fifty-six finger reconstruction cases and 73 of 74 thumb reconstruction cases had sensory flap transfers. In the free flap transfer group, 77 flaps survived (93.9%), and 5 failed. In the island flap transfer group, 140 flaps survived (97.2%), and 4 failed. Of the five-failures in the free flap transfers, four were dorsalis pedis flaps, two of which were on patients with an arteriovenous fistula. Of the four failures in the island flap transfers, two were posterior interosseous flaps and two were digital island flaps. All four were reverse-flow island flaps.

Adolescent↗
PubMed1996

A long-term study of the donor-site ankle after vascularized fibula grafts in children.

We reviewed the long-term course of the donor-site ankle after vascularized fibula grafts in 13 children. The preventive and therapeutic effects of the tibio-fibular metaphyseal synostosis (T-F synostosis) against valgus ankle deformity, which is one of the postoperative donor-site problems, were evaluated based on three radiologic and clinical parameters. Thirteen patients were divided into two groups: patients with or without simultaneous T-F synostosis when the fibula was taken. Three patients underwent T-F synostosis secondarily after the development of the valgus deformity. Follow-up periods averaged 12.4 years. In the patients with primary T-F synostosis, valgus deformity was only observed in one case. No functional disorder of the ankle joints was observed after T-F synostosis. In the patients without T-F synostosis, all the patients younger than 8 years old showed valgus deformity, in which the tilting angle averaged 6.3 degrees. In the three patients who underwent T-F synostosis secondarily, the tilting angle normalized in cases in which the fixation was performed when the lateral wedging was in a mild stage. There was a statistically significant difference in valgus tilt angle between the two groups (with or without T-F synostosis).

Adolescent↗
PubMed1996

Histologic and biochemical analysis of osteogenic capacity of vascularized periosteum.

We analyzed the osteogenic capacity of the vascularized periosteum histologically and biochemically using a new experimental model of the vascularized tibial periosteum-hydroxyapatite composite in rats. Bone formation was observed not only on the surface but also in the pores of the hydroxyapatite at 4 weeks. The alkaline phosphatase activity increased to a peak at 2 weeks, with half this activity maintained until 8 weeks. The bone-specific bone gla protein content increased constantly as time passed. On the other hand, in the vascularized fascia-hydroxyapatite composite group (control group), no bone formation was observed histologically, alkaline phospatase activity was low, and bone gla protein content was very low. These results indicate that (1) the vascularized periosteum has the most significant osteogenic capaacity at 2 weeks, with a constant level of the activity maintained thereafter, (2) it forms new bone soon after operation, and (3) the amount of bone increases as time passes.

Alkaline Phosphatase↗
PubMed1996

Radical forearm flap with vascularized tendons for hand reconstruction.

We treated six patients with soft-tissue defects involving the skin and extensor or flexor tendons using a cutaneotendinous radial forearm flap. There were five male patients and one female patient. Their ages at operation ranged from 22 to 65 years (mean 50 years). In one patient, the flexor pollicis longus tendon was reconstructed with a palmaris longus tendon graft. Four patients each had two extensor tendons reconstructed. This was performed either with the palmaris longus tendon folded in the center (n = 2) or with the palmaris longus and flexor carpi radialis tendons (n = 2). In the remaining patient, three extensor tendons were reconstructed with the palmaris longus and flexor carpi radialis tendons. All the flaps survived. Recovery of motor function has been satisfactory in all but one patient.

Adult↗
PubMed1996

Isolation and genetic characterization of pGKL killer-insensitive mutants (iki) from Saccharomyces cerevisiae.

The linear double stranded DNA plasmid pGKL1 encodes the yeast killer toxin complex (Gunge et al., 1981) of which the killing mechanism is not understood. We isolated and characterized eight mutants in Saccharomyces cerevisiae that were insensitive to both the intracellularly expressed 28-kDa killer subunit and the native killer toxin complex. These mutations (iki1 through iki5) were all recessive, and classified into five complementation groups. The iki2 mutation was mapped to a position near the centromere on chromosome XIII. We developed a novel screening system to isolate the DNA fragments complementing the iki mutations from a Saccharomyces gene library, and isolated three DNA fragments that complement the iki1, iki3, and iki4 mutations, respectively.

Cloning, Molecular↗
PubMed1996

Molecular cloning of a partial cDNA clone encoding the C terminal region of chicken breast muscle connectin.

The cDNA sequence encoding the C terminal region of chicken skeletal muscle connectin was described. Its predicted amino acid sequence had 1,021 amino acids comprising six motif Ils (Immunoglobulin C2 domain) and five interdomains. The sequence showed 70-75% homology with that of human cardiac connectin, but 168 amino acids including one motif II were missing in chicken skeletal muscle connectin. The C terminal sequence of chicken skeletal muscle connectin reported by the previous work (Maruyama et al., 1994) was erroneous due to the accidental ligation of the cDNA clone encoding a N terminal region of connectin with a partial porin cDNA clone.

Amino Acid Sequence↗
PubMed1996

[The relationship between daily activity rhythms and depression in college freshman].

The purpose of this study was to analyze the relationship between daily activity rhythms and depression college freshmen. A questionnaire was administered to 226 college freshmen, which contained scales for daily activity rhythms (e.g., keeping early vs. late hours), perceived state of own health, and degree of depression. Path analysis of the variables revealed that the path diagrams for normal-rhythm and confused-rhythm groups were different. In the normal-rhythm group, the daily activity rhythms did not affect depression tendency, whereas in the confused group, daily rhythms had both direct and indirect effects on depression tendency. The results suggest that disturbance in daily activity rhythms causes a depression tendency in college freshmen.

Activities of Daily Living↗
PubMed1995

Release of biological activities from quiescent fibronectin by a conformational change and limited proteolysis by matrix metalloproteinases.

We reported that specific biological activities are confined to three domains of the fibronectin (Fn) molecule [Fukai et al. (1991) J. Biol. Chem. 266, 8807; Fukai et al. (1993) Biochemistry 32, 5746]: the potent ability to stimulate the adipocyte differentiation of ST-13 cells is in the amino-terminal fibrin-binding (Fib 1) domain (referred to as Fib 1 domain activity); the RGD-dependent activities that stimulate NIH-L13 cell migration and inhibit adipocyte differentiation are in the central cell-binding (Cell) domain (Cell domain activity); and the activity that stimulates cell migration in a RGD-independent manner is in the carboxyl-terminal fibrin-binding (Fib 2) domain (Fib 2 domain activity). Human plasma Fn which was purified without exposure to a denaturant, such as urea, exhibited no Fib 1, Fib 2, or Cell domain activity. By exposure to urea or surface adsorption, Fn showed Cell domain activity but not those of the Fib 1 and Fib 2 domains. Whether the cryptic domain activities are disclosed or not depended on whether or not the responsible domains were irreversibly exposed from confined environments of Fn structure as confirmed by light-scattering measurement and enzyme immunoassay using domain-specific monoclonal antibodies. We then investigated the action of matrix metalloproteinases (MMPs) in liberating the Fib 1, Cell, and Fib 2 domain activities. Matrilysin released only the Cell domain activity. In contrast, stromelysin, collagenase, and especially gelatinase A additionally liberated the Fib 1 and Fib 2 domain activities. The Fib 1, Fib 2, and Cell domains acquired much higher activities when they were freed from linkage with adjacent domains.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1995

A eukaryotic gene encoding an endonuclease that specifically repairs DNA damaged by ultraviolet light.

Many eukaryotic organisms, including humans, remove ultraviolet (UV) damage from their genomes by the nucleotide excision repair pathway, which requires more than 10 separate protein factors. However, no nucleotide excision repair pathway has been found in the filamentous fungus Neurospora crassa. We have isolated a new eukaryotic DNA repair gene from N.crassa by its ability to complement UV-sensitive Escherichia coli cells. The gene is altered in a N.crassa mus-18 mutant and responsible for the exclusive sensitivity to UV of the mutant. Introduction of the wild-type mus-18 gene complements not only the mus-18 DNA repair defect of N.crassa, but also confers UV-resistance on various DNA repair-deficient mutants of Saccharomyces cerevisiae and a human xeroderma pigmentosum cell line. The cDNA encodes a protein of 74 kDa with no sequence similarity to other known repair enzymes. Recombinant mus-18 protein was purified from E.coli and found to be an endonuclease for UV-irradiated DNA. Both cyclobutane pyrimidine dimers and (6-4)photoproducts are cleaved at the sites immediately 5' to the damaged dipyrimidines in a magnesium-dependent, ATP-independent reaction. This mechanism, requiring a single polypeptide designated UV-induced dimer endonuclease for incision, is a substitute for the role of nucleotide excision repair of UV damage in N.crassa.

Amino Acid Sequence↗
PubMed1995

Mandibular reconstruction using the double barrel fibular graft.

Five patients underwent mandibular reconstruction using the double barrel fibular graft from 1989 to 1994. Bony defects ranged from 7 to 14 cm. In three patients, two skin flaps were taken with the fibular graft for composite reconstruction. In order to overcome the main disadvantage of the fibular graft, i.e., small circumference of the bone, a harvested fibula was osteotomized into several portions, folded into two parallel lengths, and fixed along the inferior border of the mandible and the alveolar ridge. The double barrel fibular graft provided more than 4-cm alveolar height without damaging bone viability. In Orientals, a fibula is approximately 1.5 cm thick, and using a single fibular strut for mandibular reconstruction may result in subsequent difficulty in wearing conventional dentures or osseointegrated implants. All patients acquired good mandibular contour and enough thickness of the alveolar ridge, and could wear a conventional denture and eat a solid diet. This procedure seems to be superior to the iliac bone graft for major mandibular reconstruction because of its length, the possibility of three-dimensional composite reconstruction, increased bone thickness, and minimal donor-site morbidity.

Adolescent↗
PubMed1995

Aneurysms of the digital artery: a review and report of three cases.

Aneurysms of the digital artery are rare. Since 1980, we have treated three traumatic aneurysms of the digital artery. There were two lesions of the common palmar digital artery and one of the ulnar pollicis artery. One case was caused by a traumatic laceration with a kitchen knife, and two cases were caused by repetitive microtrauma. On histologic examination, there were two true aneurysms and one false aneurysm. Two cases were treated by excision only, and one case was treated by excision and reanastomosis. The operating microscope was useful during neurolysis, excision of the aneurysm, and vascular anastomosis.

Adolescent↗
PubMed1995

Experimental study on choline acetyltransferase activity measurement for brachial plexus injury.

We studied choline acetyltransferase (CAT) activity in a rat model of brachial plexus injury. In experiment 1, we found that the CAT activity was remarkably high in the anterior roots and low in the posterior roots. In experiment 2, nerve root segments were extracted and examined for CAT activity in the root avulsion group (group A) and the plexus severance group (group B). CAT activity decreased day by day in group A, reaching about 1/20 of the normal 5 days postoperatively. By contrast, in group B activity decreased only slightly, and even at 90 days postoperatively was about 6,000 cpm (one-half normal level). As a result, CAT activity enabled us to distinguish postganglionic from preganglionic injury of the cervical roots. Furthermore, it was a useful adjunct for minimizing nerve loss in intercostal nerve transfer, distinguishing motor and sensory branches of the intercostal nerve, and evaluating the motor nerve activity.

Animals↗
PubMed1995

Identification and characterization of monocyte subpopulations from patients with bronchial asthma.

Monocytes are inflammatory cells that accumulate in the airway in asthma. Monocytes constitute a heterogenous cell population in normal subjects. The heterogeneity of monocytes from nine patients with mild asthma and nine normal subjects was studied by means of discontinuous density gradient centrifugation with use of bovine serum albumin. The rate of low-density monocytes recovered from patients with asthma was higher than that obtained from normal subjects. The functional activity of monocyte fractions from asthmatic and control subjects was assessed by using the release of interleukin-1 beta (IL-1 beta) and the intensity of lysosomal enzymes, such as acid phosphatase and nonspecific esterase. The low-density cells produced less IL-1 beta than did cells of higher density in normal subjects. The IL-1 beta release was increased in low-density monocytes from subjects with asthma when compared with the same fraction from normal subjects (p < 0.01). The low-density monocytes had a higher activity of lysosomal enzymes than did cells of higher density in both asthmatic and normal subjects. Electron microscopic studies showed that low-density monocytes from the subjects with mild asthma appeared to have the morphologic characteristics of activated cells with more vacuoles in this periphery. This study shows that low-density monocytes from subjects with asthma retain the ability to be activated in vivo and in vitro and may orchestrate immune reactions in mild asthma.

Adult↗
PubMed1995

Prefabricated vascularized periosteal grafts using fascial flap transfers.

The purpose of this study was to demonstrate the feasibility of prefabricated vascularized periosteal grafts using fascial flap transfers. Fifty rats were divided into two (Group A, underwent periosteal wrapping, and Group B underwent fascial wrapping). Fascial flap from the medical leg, which were nourished by the saphenous artery and vein, were used for all grafts. In Group A, the fascia was transferred onto the proximal tibial periosteum. Two weeks postoperatively, the elevated fascioperiosteal flap was wrapped around a 4-mm hydroxapatite cube. In Group B, the fascial flap was immediately wrapped around the hydroxyapatite cube. In both groups, the hydroxapatite-wrapped cube was transferred to the inguinal region. Three days postoperatively, five rats from group A were sacrificed. On histologic examination, these five showed no necrosis of the fascioperiosteal flap and no bone formation. The remaining 45 rats were sacrificed 5 weeks postoperatively. Microangiography was performed on five rats in Group A, revealing neovascularization of the hydroxyapatite. On histologic examination, new bone formation was confirmed in 15 of the remaining 20 rats in Group A, and in three of the 20 rats in Group B. These experiments demonstrated that the prefabricated vascularized periosteal graft, which has good osteogenic capacity, could be carried out using a fascial flap transfer.

Angiography↗