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Biomedical subjects

H Gunji

Publications and source records attributed to H Gunji.

At least 37 records · Page 2Linked to original sources
PubMed1995

Pneumocephalus caused by fistulas of the mastoid air cells treated with a temporoparietal fascial flap.

Using a temporoparietal fascial flap and hydroxyapatite ceramics, we treated a patient for complications after a neurosurgical operation for glossopharyngeal neuralgia. These consisted of pneumocephalus and cerebrospinal fluid rhinorrhea resulting from fistulas of mastoid air cells associated with a subcutaneous dead space. By means of the temporoparietal fascial flap, we were able to fill the dead space and reinforce the repaired dural and mastoid lesion as well. Hydroxyapatite ceramics were also useful for closing the mastoid air cell fistulas.

Bone Diseases↗
PubMed1995

Bone induction of hydroxyapatite combined with bone morphogenetic protein and covered with periosteum.

Using a rabbit model, we evaluated the role of the periosteum in bone induction using hydroxyapatite ceramic pellets, some of which had been coated with bone morphogenetic protein. Eighteen rabbits were divided into two groups, a control group that received pellets soaked in phosphate-buffered saline alone and another group for which the pellets had been supplemented with bone morphogenetic protein. After making a skin incision on the head of each rabbit, two caudally pedicled periosteal flaps measuring 1 cm in width and 2.5 cm in length were elevated. These flaps were wrapped around hydroxyapatite pellets manufactured from limestone and fixed with sutures. After implantation, both groups of rabbits were returned to their cages, maintained for 3, 6, or 9 weeks [every group consisted of 3 rabbits (6 pellets)], and then sacrificed. In this study, the extent of bone induction, which was measured with a dual x-ray densitometer, that resulted from covering the hydroxyapatite pellet with periosteum alone (control group) was minimal. On the contrary, since osteogenesis from the periosteum toward the pores of the pellet was observed in the bone morphogenetic protein group much more than in the control group, the usefulness of our technique was confirmed. However, active osteogenesis was observed with subperiosteal implantation of the hydroxyapatite-bone morphogenetic protein complex in the bone morphogenetic protein group, but the osteogenesis observed was not distributed over the entire pellet.

Animals↗
PubMed1995

A new operative method for treating severe cryptotia.

Results following surgical treatment for cryptotia are as yet far from fully satisfactory in cases in which deformity of the upper auricular portion is severe and particularly when there is contraction of the helical skin and auricular cartilage. Therefore, improvements in operative procedures have been considered necessary. We have developed a new method for treating cryptotia using a rhomboid flap in the superior and anterior auricular regions to correct the contraction of skin in the helix in cases in which the deformity of the upper auricular portion is large and shortening in the anterior and posterior directions is significant and in which severe contraction of the helix is observed. In this report, we describe the operative procedures used and present the relatively favorable results obtained in three patients. Using these techniques, we have been able to elongate the contracted helix frequently observed in cases of cryptotia by preparing a flap in the anterior auricular region. This approach appears to be a useful and safe means of treating cryptotia and so-called constricted ear as well.

Child, Preschool↗
PubMed1994

Immunocytochemical study of seminal gamma-glutamyltransferase using monoclonal antibodies.

We produced three monoclonal antibodies, SG1, SG2 and SG3, specific for human seminal gamma-glutamyltransferase when characterized by enzyme-linked immunosorbent assay and immunoblotting. Seminal gamma-glutamyltransferase was localized, by immunostaining, to the epithelial cells of the ductus epididymidis, seminal vesicle and prostate gland with SG1, those of the prostate gland with SG2, and those of the seminal vesicle with SG3. Rabbit polyclonal anti-seminal gamma-glutamyltransferase serum reacted with the proximal convolution of the kidney and the bile capillaries of the liver, and with the epithelial cells of the reproductive organs. However, immunoreactivity was not observed in the kidney or liver with the monoclonal antibodies. Thus, these monoclonal antibodies are probably all specific to seminal gamma-glutamyltransferase but recognize different epitopes.

Animals↗
PubMed1994

Effects of cilostazol lotion on blood flow in rabbit skin.

Cilostazol (Cls) is a inhibitor of phosphodiesterase and increases cyclic AMP (cAMP) in platelets and also raises the vascular smooth muscle cell cAMP level causing vasodilation. Therefore, it was expected to increase local blood flow in the skin. Topical application of Cls may improve local blood flow without systemic effects in clinical situations. In this paper the effect of Cls lotion on skin blood flow was assessed in animal experiments. Application of this lotion allowed skin blood flow to remain at increased levels for about 60-90 min. Tissue assay of the Cls content revealed that Cls is absorbed percutaneously and retained, even in the inner tissue layer, for at least 180 min.

Administration, Cutaneous↗
PubMed1994

Method for preparing an exact-size model using helical volume scan computed tomography.

Helical volume scan computed tomography is a recently developed technology by means of which detailed data for most facial bone areas can be accumulated in a very short period, i.e., about 30 seconds, a much shorter time than required with conventional computed tomography. From a clinical standpoint, this is extremely important. In this report we discuss the principles of a method for preparing actual-size models by laser lithographic procedures based on data obtained by helical volume scan computed tomography. With these procedures, it is possible to obtain a good reproduction with high accuracy, on the order of 0.5 mm, not only of the outer morphologic structure of the cranial and maxillofacial bones but also of portions of the inner structure of cavities such as the cranium and paranasal sinuses. The difference between the original and model was under 3 percent, as confirmed by constructing a model of the dry skull with helical volume scan computed tomography. Therefore, production of exact-size models using helical volume scan computed tomography data represents an important technological development, breaking through previous limits imposed by conventional simulations prepared with three-dimensional images using CRT. With the combined use of laser lithographics and helical volume scan computed tomography, operative methods for craniomaxillofacial surgery should improve significantly in the near future.

Adult↗
PubMed1994

Orbital reconstruction with hydroxyapatite ceramic implants.

Thirteen patients with fractures of the orbital floor (inferior wall), medial and lateral walls, or so-called "blowout" fractures with or without fractures of the zygoma were treated with artificially made hydroxyapatite ceramic implants made entirely from limestone, some of which were made with computer aided design and computer aided machinery (CAD-CAM) from data obtained from helical computed tomography. Orbital reconstruction with hydroxyapatite ceramic implants is a safe technique which is superior to previous ones in which autogenous or plastic materials were used.

Adult↗
PubMed1994

Evaluation of cytokines in donor site wound fluids.

The aim of the study was to measure concentrations of cytokines in wound fluid from donor sites. A film dressing was applied to the donor sites (mean size 10 x 15 cm) immediately after a split skin graft had been taken. Five days later the film was punctured with a needle and 2-3 ml of the fluid accumulated under the film dressing was withdrawn into a syringe. The fluid was snap frozen and stored immediately at -70 degrees C. The fluid was examined for epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor (TGF) alpha, TGF beta, interleukin (IL)-1 alpha and IL-1 beta. The results showed that the fluid accumulated under the film dressing contained growth factors and cytokines that are thought to promote healing. The fluid was rich in TGF alpha but contained no EGF or bFGF, which indicates that TGF alpha plays a major part for promoting local wound healing.

Adult↗
PubMed1994

Comparison of kinetic property between human seminal and renal gamma-glutamyltransferase.

The initial-velocity kinetics, optimal pH, acceptor specificity and the influence of metal ions, EDTA and urea were studied on the human seminal gamma-glytamyltransferase (GGT) in comparison with the human renal GGT. The activity was measured with glycylglycine as an acceptor and with gamma-glutamyl-4-nitroanilide or gamma-glutamyl-3-carboxy-4-nitroanilide as a donor. Because the double-reciprocal plots showed paralled lines, the reaction of seminal GGT proceeds in nonsequence (Ping Pong Bi Bi) mechanism. The acceptor Michaelis constants for the seminal GGT were about 2 times higher than those for the renal enzyme with gamma-glutamyl-3-carboxy-4-nitroanilide as well as gamma-glutamyl-4-nitroanilide as donors, which the donor michaelis constants for seminal GGT were very similar to those for renal enzyme. The optimal pH and pK values were 8.2-8.6 and about 7.7, respectively. There was little difference in the specificity for various acceptors between the seminal and renal enzyme. Glycylglycylglycine was an effective acceptor other than glycylglycine, showing 80% of the activity with glycylgycine. Various substrates including metal ions tested were practically neither inhibitory nor stimulatory for seminal and renal GGTs.

1-Carboxyglutamic Acid↗
PubMed1993

Substrate specificity of 6-deoxyerythronolide B hydroxylase, a bacterial cytochrome P450 of erythromycin A biosynthesis.

The 6-deoxyerythronolide B hydroxylase (EryF) is a soluble cytochrome P450 responsible for the stereospecific C-6 hydroxylation of the erythromycin precursor, 6-deoxyerythronolide B. Using the expression of the eryF gene in Escherichia coli [Andersen, J. F., & Hutchinson, C. R. (1992) J. Bacteriol. 174, 725-735] as the enzyme source, we examined the catalytic activity of the EryF protein toward several macrolide substrates related to 6-deoxyerythronolide B. The results of these studies were compared with measurements of the apparent dissociation constants for various substrates and with information from molecular modeling studies of the substrates and the enzyme-substrate complex. Only minor changes in the structure of 6-deoxyerythronolide B resulted in substrates with catalytic rates less than 1% of those seen with the natural substrate. Although the 9S epimer of 9-deoxo-9-hydroxy-6-deoxyerythronolide B was hydroxylated at a rate approximately equal to the natural substrate, the 9R epimer was hydroxylated at a 2-fold lower rate. Examination of molecular models revealed that the position of the 9-hydroxyl oxygen in the 9S epimer resembles that of the 9-oxo oxygen in the natural substrate more closely than in the 9R epimer. 8,8a-Deoxyoleandolide, which is identical to 6-deoxyerythronolide B except for the presence of a C-13 methyl group, and its (9S)-9-deoxo-9-hydroxy derivative were C-6 hydroxylated at a 4-fold lower rate than the natural substrate, and the 9-oxo form showed a substantially larger apparent dissociation constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

Studies of tissue cultured sliced dermis as a skin substitute.

A dermis slicer designed by the authors enabled us to prepare about 10 sheets of sliced dermal grafts (SDG), 300 micron(s) thick, from the dermis harvested from the back or buttocks of adult patients during operations. Such a sliced dermal sheet was stretched with one surface stuck on the base of a culture dish. It was then incubated in Dulbecco's essential medium for tissue culture, to which epidermal growth factor had been added. By the first week only its upper side was epithelialized from epithelial components in sliced dermis. The formation of basement membrane with anchoring fibrils was confirmed by electron microscopy. The appearance of type IV collagen and laminin was observed between epithelialized basal cells and the dermal layer. Thus, it is thought that the SDG is useful not only for immediate grafting, when epithelialization follows, but also as a substitute for free split thickness skin grafts following tissue culture.

Cells, Cultured↗
PubMed1993

Effects of a platelet activating factor antagonist on oedema formation following burns.

Deep dermal burns covering 30 per cent of the total body surface area were prepared by immersing the backs of rabbits in hot water at 80 degrees C for 20 s, to determine whether platelet activating factor (PAF) was involved in the onset of oedema following burns and to evaluate the effect of TCV-309, a potent PAF antagonist. The PAF antagonist, which was infused soon after the burn, blocked oedema formation in the wound and significantly (P < 0.001) inhibited PAF increase (P < 0.05) in the damaged tissue in a dose-dependent manner. This was confirmed by immunohistochemistry. In contrast, the superoxide dismutase content in the group treated with a high dose of TCV-309 was significantly (P < 0.01) higher than that of the control group. These findings suggest that administration of large doses of a PAF antagonist immediately after injury prevents oedema of burn wounds and the subsequent onset of burn shock by suppressing PAF and superoxide radical formation.

Animals↗
PubMed1993

Use of the oblique island flap in excision of small facial tumors.

Reconstruction with the oblique sigmoid island flap, which we contrived as a subcutaneous pedicle flap, is performed as follows: the small triangular skin flaps, about 1 to 2 mm in length on each side, are excised from both sides of a round defect following tumor excision in a direction corresponding to the wrinkle line, and a subcutaneous island flap which has a width equal to the defect and has shifted about half the distance of the defective area in parallel with the wrinkle line is advanced and sutured. Our technique is thought to be highly effective from a cosmetic point of view because reconstruction of the defects following excision of small tumors that occur in sites with delicate eminence, such as the area between the inner canthal region and the cheek, the site along the nasolabial fold, and around the alae, often tends to fail to achieve cosmetically good results when conventional local skin flaps are used.

Adult↗
PubMed1993

A method of treatment of constricted ears with a conchal cartilage graft to the posterior auricular plane.

In order to make natural auricular features in a simple and certain way and also to prevent the occurrence of a postoperative lop-eared deformity, we contrived a new method to treat constricted ears. Our method consists of correction of the anthelical deformity according to a modified Converse method and a cartilage graft harvested from the posterior region of the concha to fix as a support on the posterior auricular plane which enables the auricle to maintain a normal shape. This method resulted in very satisfactory treatment of prominent ears or ears with mild helical constriction, categorized as group I, IIa, or IIb on Tanzer's classification, and the patients did not have marked postoperative problems. Thus, in this respect, our technique is considered to be a very effective and safe method.

Cartilage↗
PubMed1993

Treatment of extensive cranial bone defects using computer-designed hydroxyapatite ceramics and periosteal flaps.

We performed cranioplasty using hydroxyapatite ceramics and periosteal flaps in three patients with extensive cranial bone defects. These defects were left after post-brain surgery infection forced the removal of cranial bone. Hydroxyapatite ceramics made by using computer-aided design from three-dimensional computed tomographic image data were implanted in these patients. The defects were relatively large (the largest was 16.5 x 7.5 cm) and had a high degree of curvature. Three pieces were required in one patient, although one piece was sufficient in the other two patients. The surgical technique consisted of removal of the epidural granulation tissue, exposure of the cranial bone defect site, and shaping of the hydroxyapatite ceramics to fit the defect entirely, followed by the implantation of the hydroxyapatite ceramics. In anticipation of induction of the bone to hydroxyapatite, we covered the hydroxyapatite ceramics with periosteal flaps of cranial bones; however, based on only these three patients, our knowledge of the ossification-promoting effect is incomplete. More clinical cases should be investigated to evaluate further the clinical efficacy of this method for treatment. As we have reported here, the treatment of cranial bone defects by using computer-designed hydroxyapatite ceramics and a periosteal flap is safe and highly effective.

Adult↗
PubMed1993

Phorbol ester-induced monocytic differentiation is associated with G2 delay and down-regulation of cdc25 expression.

Treatment of human U-937 myeloid leukemia cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with growth arrest and induction of monocytic differentiation. The present results demonstrate that exposure of G1- or S phase-enriched U-937 cells to TPA was associated with delayed transition through G2-M and then exit from the cell cycle in the subsequent G0-G1 phase. In contrast, G2-M cells treated with TPA progressed through G1-S, were delayed in the next G2-M phase, and then entered a nonproliferative G0-G1 state. The effects of TPA on expression of cell cycle control genes demonstrated down-regulation of the cdc25 mitotic inducer during S-G2 progression. In order to investigate the role of cdc25 in the control of cell cycle progression, U-937 cells were stably transfected with an antisense cdc25 construct under control of a metallothionein-inducible promoter. Expression of this construct in G1 phase cells was associated with a significant delay in transition through S and G2-M phase. Similar results were obtained when G1 phase cells were incubated with a 14-base pair antisense cdc25 oligomer. Taken together, these results indicate that the cdc25 gene product is functionally associated with S-G2 transition of proliferating myeloid leukemia cells and that down-regulation of this gene by TPA is associated with G2-M delay.

Base Sequence↗
PubMed1992

Inhibition of EGR-1 and NF-kappa B gene expression by dexamethasone during phorbol ester-induced human monocytic differentiation.

The treatment of human myeloid leukemia cells (HL-60, U-937, THP-1) with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with growth arrest and appearance of a differentiated monocytic phenotype. While previous studies have reported that the glucocorticoid dexamethasone blocks phenotypic characteristics of monocytic differentiation, we demonstrated in the present work that dexamethasone delays the effects of TPA on the loss of U-937 cell proliferation. We also demonstrated that this glucocorticoid inhibits TPA-induced increases in expression of the EGR-1 early response gene. The results of nuclear run-on assays and half-life experiments indicated that this effect of dexamethasone is regulated at the post-transcriptional level. Similar studies were performed for the NF-kappa B gene. While TPA treatment was associated with transient increases in NF-kappa B mRNA levels, this induction was blocked by dexamethasone. In contrast, dexamethasone had no significant effect on the activation of pre-existing NF-kappa B protein as determined in DNA-binding assays. Taken together, these findings suggest that the activated glucocorticoid receptor inhibits signaling pathways which include expression of the EGR-1 and NF-kappa B genes and that such effects may contribute to a block in TPA-induced monocytic differentiation.

Base Sequence↗