Search PubMed⌕ Search

Biomedical subjects

K Fukuta

Publications and source records attributed to K Fukuta.

At least 37 records · Page 2Linked to original sources
PubMed1999

Recovery of olfactory function after an anterior craniofacial approach.

We assessed recovery of olfactory function in five consecutive patients who underwent surgical resection of midline skull base tumors using an anterior craniofacial approach in which the cribriform plate was mobilized with the dura. Olfactory function was evaluated before and after surgery using an intravenous olfactory test with prosultiamine and also a standard olfactory acuity test. Before surgery, one patient showed anosmia attributable to obstruction of the nasal cavity and olfactory cleft, and four patients showed normal olfactory function. After surgery, one patient was irreversibly anosmic, probably because of intradural dissection of the olfactory tracts. The other four patients, including the patient showing anosmia preoperatively, reported subjective recovery of olfaction 3 to 8 weeks after surgery. Intravenous and standard olfactory acuity tests indicated recovery of olfaction to the normal range in three patients and decreased olfactory function in one. With careful preservation of the olfactory system and of the integrity of the nasal cavity, olfactory function was found to recover after skull base resections via the anterior craniofacial approach.

Journal Article↗
PubMed1999

Characterization of fibroblast growth factor-6 expressed by Chinese hamster ovary cells as a glycosylated mitogen for human vascular endothelial cells.

The gene for fibroblast growth factor (FGF)-6/hst-2 was originally identified by its close homology with the FGF-4/hst-1 gene. Aside from its ability to transform cultured fibroblasts, the characteristics of FGF-6 protein have only been studied using a simple preparation from E. coli. In the present study, we expressed FGF-6 cDNA in CHO cells and characterized the resultant protein. We found that CHO cells secreted several forms of the FGF-6 polypeptide, and that there were multiple N-terminal modifications. The longest form (18-kDa) contained the sequence, SerProAlaGlyAlaArg, as its N-terminus, which was consistent with the signal peptide cleavage site predicted from its primary structure. The core polypeptide was primarily modified by heterogeneous N-glycans that were sialylated to a small degree; among them, biantennary structures were found to predominate. Moreover, possible O-glycosylation was also detected. N-glycosylated FGF-6 potently induced DNA synthesis and proliferation of human vascular endothelial cells, whereas in the absence of N-glycosylation, FGF-6 mitogenicity was substantially diminished. The results clearly indicate that FGF-6 expressed by mammalian cells is a glycosylated mitogen for vascular endothelial cells and further suggests that N-glycosylation plays a key role in determining the mitogenicity of FGF-6.

Animals↗
PubMed1998

A comparison of single-stage versus gradual fronto-parietal advancement in terms of extradural dead space and bone deposition.

This study was designed to investigate the differences between single-stage and gradual advancement of cranial vault in adult cats. Fifteen animals underwent fronto-parietal craniotomy including the roof of the frontal sinus. They were randomly assigned to three experimental groups; single-stage advancement (n = 5), gradual distraction with intact dura-bone attachments (n = 5), and gradual distraction after separation of the dura from the fronto-parietal bone segment (n = 5). Development of an extradural dead space and new bone formation were evaluated with CT scans at 1, 4 and 12 weeks. After sacrificing the animals at 12 weeks, midsagittal frozen sections and decalcified coronal sections of the heads were obtained. The single-stage advancement group developed an extradural dead space which communicated with the frontal sinus. The advanced bone segment, which was exposed to the air-filled dead space, showed bony resorption. Both groups of gradual advancement showed enlargement of the cranial cavity and frontal sinus. As the dura and brain were stretched superiorly, no extradural dead space was produced. Although the distraction gap demonstrated deposition of new bone in both gradual advancement groups, the bone formation was less pronounced in distraction after separating the dura from the bone segment. In conclusion, gradual distraction of a fronto-parietal bone prevents extradural dead space formation regardless of whether the dura is kept attached to or it is separated from the distracted bone segment. Devascularization of the bone segment by dissecting off the dura, however, decreases new bone formation, and thus may increase a risk of relapse.

Animals↗
PubMed1998

Segmental mandibular reconstruction by distraction osteogenesis under skin flaps.

In five adult dogs, molars were extracted and skin flaps from the neck prepared for delayed transplantation. Two weeks later, a 25-mm segment of the mandible was excised with surrounding periosteum and gingiva. The mandible was stabilized with a reconstruction plate and the intraoral defect repaired with a pedicled skin flap. A proximal transport segment was created and an external distraction device was applied. After one week, distraction of the transport segment was begun at a rate of 1 mm/day. After distraction was completed, the lengthening appliance was left in place for 12 weeks until the dogs were killed. Radiologic and histologic examination revealed new bone at the distraction site. The intraoral skin flap was pushed out of the defect as distraction progressed. Bony union of the transport segment to the distal stump was not achieved due to intervening soft tissue. These results suggest that it is feasible to bridge a mandibular defect that is covered with a skin flap, with distraction osteogenesis.

Animals↗
PubMed1998

Somatotopic representation within the facial motor nucleus of the chicken studied by means of horseradish peroxidase.

The distribution in the chicken of motoneurons innervating the hyolingual muscles, i.e. the M. branchiomandibularis (BM), M. ceratoglossus (CG), M. interceratobranchialis (CB), M. serpihyoideus (PH), M. stylohyoideus (YH) and one of the mandibular muscles, M. depressor mandibulae (DM), was examined by retrograde transport of horseradish peroxidase conjugated with wheatgerm agglutinin. Labelled motoneurons are found in the three subnuclei of the facial (VII) nucleus, as well as hypoglossal (XII) nucleus. The distribution of motoneurons projecting to the DM are observed in the three subnuclei, those of the BM, PH and YH in the intermediate and ventral subnuclei and those of the CB and CG in the intermediate subnucleus. Motoneurons projecting to the PH, YH, CB and CG are also distributed in the XII nucleus. The ratio of labelled motoneurons of the VII to XII nuclei decreases the PH, YH, CB and CG in that order, and the ratio of labelled ones of the ventral to intermediate subnuclei decreases the BM, PH and YH in that order. The topographical and functional aspects of the subdivision of the motor nucleus are discussed.

Animals↗
PubMed1998

Holmium:YAG laser resection of the prostate versus visual laser ablation of the prostate and transurethral ultrasound-guided laser induced prostatectomy: a retrospective comparative study.

BACKGROUND: Transurethral resection of the prostate (TUR-P) is the gold standard for treating symptomatic benign prostatic hyperplasia (BPH) despite some perioperative morbidity. As a minimally-invasive alternative to TUR-P, a neodymium:YAG laser, and more recently a holmium:YAG laser, have been used in transurethral surgery for BPH. In order to assess the safety and efficacy of various BPH treatments, the outcome in patients treated with transurethral ultrasound-guided laser induced prostatectomy (TULIP), visual laser ablation of the prostate (VLAP) and holmium:YAG laser resection of the prostate (HoLRP) were retrospectively compared. METHODS: From May 1995 to August 1996, 60 patients with symptomatic BPH underwent TULIP (n=20), VLAP (n=20), and HoLRP (n=20). All patients were evaluated preoperatively and at 1 and 3 months postoperatively by the International Prostate Symptom Score (IPSS), the IPSS quality-of-life score (QOL), maximum flow rate (MFR), prostate volume, and residual urine volume. RESULTS: The preoperative mean IPSS was 18.5, 19.3, and 19.6 and the mean MFR was 6.3, 6.9, and 6.1 mL/sec in the TULIP, VLAP, and HoLRP groups, respectively. At 1 month after surgery, the mean IPSS was 10.2, 9.5, and 4.7 and the mean MFR was 9.6, 13.4, and 18.7 mL/sec while at 3 months the mean IPSS was 6.2, 6.1, and 3.6 and the mean MFR was 14.1, 16.0, and 21.5 mL/sec in patients treated with TULIP, VLAP, and HoLRP, respectively. No serious complication occurred in any patient. CONCLUSION: Although HoLRP requires expertise, it appears to be a promising treatment modality for BPH.

Aged↗
PubMed1998

Significant prognostic factors for 5-year survival after curative resection of renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) patients occasionally die of RCC even after curative resection. In this study, we investigated prognostic factors between survivors for more than 5 years and patients who died within 5 years after curative resection. METHODS: We retrospectively studied 111 patients who underwent RCC curative resection and were followed for more than 5 years. Patient survival at 5 years after curative resection was regarded as the end-point of this analysis. Statistical differences of 19 prognostic factors between surviving and deceased patients were determined using logistic regression analysis. RESULTS: Eighteen of the 111 patients died of RCC during the 5-year follow-up period. Of the 19 prognostic factors evaluated, univariate analysis showed significant differences in the body temperature, hemoglobin, erythrocyte sedimentation rate (ESR), alpha2-globulin, C-reactive protein (CRP), fibrinogen, tumor size, Robson's stage, T classification (renal capsular involvement), pathological grade, and mode of tumor infiltration. Five significant variables (body temperature, ESR, alpha2-globulin, fibrinogen, and tumor size) were excluded from multivariate analysis because greater than 10% of the data was missing. The TNM staging system was selected as the representative variable for stage for multivariate analysis. Using the remaining 5 significant variables (hemoglobin, CRP, T stage, pathological grade, and mode of tumor infiltration), multivariate analysis showed that CRP (P = 0.0126) and T stage (P = 0.0490) were the most important prognostic factors. CONCLUSION: From this analysis, CRP and renal capsular involvement were the most important factors predicting survival for greater than 5 years after curative resection of RCC.

Adult↗
PubMed1998

Benign fibroosseous lesions involving the skull base, paranasal sinuses, and nasal cavity. Report of two cases.

The authors report two patients with benign fibroosseous lesions involving the center of the skull base: a 15-year-old boy with repetitive meningitis and pneumocephalus and a 11-year-old boy with nasal obstruction and headache. The clinical diagnoses were ossifying fibroma and aneurysmal bone cyst, respectively. Lesions in both patients extended to the nasal cavity, the sphenoid and posterior ethmoid sinuses, and the skull base, where the planum sphenoidale, the sella turcica, the upper two-thirds of the clivus, and the medial portion of the middle cranial base were involved. The lesions were totally removed using an anterior craniofacial approach. Characteristics of these lesions and the surgical approach are discussed.

Adolescent↗
PubMed1998

Ultrastructure of enkephalin- and substance P-immunoreactive axon terminals in the hypoglossal nucleus of the chicken.

The morphology and distribution of leucine-enkephalin (LENK)- and substance P (SP)-containing axon terminals in the hypoglossal nucleus of the chicken was investigated immunocytochemically at the electron microscopic level. The major findings of the present study were as follows: 1) Both LENK- and SP-immunoreactive (IR) profiles including unmyelinated axons, varicosities and axon terminals were found throughout the hypoglossal nucleus. 2) LENK-IR profiles without synapses (preterminal axons and varicosities) were observed more frequently (66%) than LENK-IR synaptic profiles (34%). In contrast, SP-IR synaptic terminals were seen more often (68%) than SP-IR terminals without synapses (32%). 3) Both LENK- and SP-IR synaptic terminals ending on dendrites were more numerous (83% and 94%, respectively) than those making synapses on somata (17% and 6%, respectively). 4) The average diameter of SP-IR synaptic terminals were significantly larger than that of LENK-IR ones. 5) Both LENK- and SP-IR synaptic terminals contained numerous small clear vesicles and several large dense-cored vesicles (LDV). Although both LENK- and SP-IR synaptic terminals contained LDV consistently, SP-IR synaptic terminals contained significantly more LDV than LENK-IR types. 6) Postsynaptic dense bodies (Taxi bodies) were seen more frequently in SP-IR synaptic terminals than in LENK-IR ones. These findings confirm both LENK and SP innervation in the hypoglossal nucleus and suggest a functional role as neuromodulator for the two neuropeptides in tongue control.

Animals↗
PubMed1997

Topical administration of prostaglandin E1 with iontophoresis for skin flap viability.

This study was performed to investigate the capability of iontophoretic delivery of prostaglandin E1 (PGE1) and the effect of this treatment on the viability of skin flaps on the rat dorsum model as described by Hammond and Ronald in 1993. The PGE1 level in the tissue sample under the electrode was assessed with radioimmunoassay. The iontophoretic treatment (for 20 minutes at 4 mA) with PGE1 solution (20 micrograms PGE1 in 2 ml saline) showed a significant increase of PGE1 in the flap tissue under the negative electrode (p < 0.05). Very little increase was observed after the iontophoresis of saline alone. This was not statistically significant. Iontophoretic treatment was given for 5 consecutive days following flap elevation. The survival area on the seventh postoperative day was significantly greater in the PGE1-treated flaps than that of either the control or saline-treated flaps. These results confirm the beneficial effect of iontophoretic treatment with PGE1 on the augmentation of skin flap viability.

Administration, Topical↗
PubMed1997

Surgical approach to midline skull base tumors with olfactory preservation.

Through the frontal approach, a skull base tumor in the deep midline region is obscured by the cribriform plate. This paper demonstrates our experience of operating on seven patients with midline skull base tumors posterior to the cribriform plate using a technique of maintaining the olfactory-cribriform anatomy. Following a bifrontal craniotomy and an orbitonaso-glabellar osteotomy, a circumferential osteotomy of the cribriform plate and horizontal incision of the nasal mucosa permitted mobilization of the cribriform plate unit along with the frontal lobe, providing a wide exposure of the posterior midline area. Tumors were resected from the posterior nasopharynx, ethmoid sinus, sphenoid sinus, and upper portion of the clivus. The skull base defects were repaired with the bipedicled temporoparietal galeal flap. Two patients lost olfaction because of poor preservation of the nasal mucosa and intradural dissection of the olfactory bulb. Five patients showed complete recovery of olfaction in 8 weeks. None of the patients developed cerebrospinal fluid leakage, infection, or increased neurologic deficits. En bloc mobilization of the cribriform plate and the bipedicled temporoparietal galeal flap are very useful for the management of midline cranial base tumors posterior to the cribriform plate as long as the olfactory unit is not involved with tumors.

Adolescent↗
PubMed1997

Pattern of X-Y chromosome pairing in the Japanese field vole, Microtus montebelli.

Pairing of X and Y chromosomes at meiotic prophase in males of Microtus montebelli was analyzed. The sex chromosomes form a synaptonemal complex at pachytene and end-to-end association at diakinesis-metaphase I in two species of the genus Microtus (M. montebelli and M. oeconomus) only, while they do not pair at all in the other species of this genus that have been studied so far. These data confirm that M. montebelli and M. oeconomus are very closely related in their origin. It is suggested that the sex chromosomes of M. montebelli and M. oeconomus display the ancestral type of X-Y pairing. The lack of X-Y pairing in most species of Microtus appeared after the split in lineage that led to M. oeconomus and M. montebelli on the one hand and the remaining species on the other.

Animals↗
PubMed1997

Distribution of neuropeptide-immunoreactive nerve fibres in the medulla oblongata of the chicken.

The anatomical distribution of nerve fibres containing galanin (GAL), leucine enkephalin (lENK), methionine enkephalin (mENK) and substance P (SP) was investigated in the medulla oblongata of the chicken by means of immunohistochemistry. In the medulla oblongata, dense networks of mENK-, lENK-, SP- and GAL-immunoreactive nerve fibres were mainly restricted within and around the dorsal vagal complex, i.e., the nucleus of the solitary tract and dorsal motor nucleus of the vagus nerve. The relative density of immunoreactive nerve fibres was usually decreased in the order of mENK-, SP-, lENK- and GAL-immunoreactive ones. Immunoreactive nerve fibres for each antiserum had a unique distribution among the subnuclear groups of the dorsal vagal complex. Sparser networks of immunolabelled nerve fibres were found in the nucleus of the hypoglossal nerve, nucleus ambiguus, nucleus of the descending trigeminal tract, raphe nucleus and caudal olivary complex. In the colchicine-pretreated chicken, some nerve cell bodies expressing the immunoreaction for ENK and GAL antisera were detected in the nucleus of the solitary tract and nucleus of the descending trigeminal tract. There were some differences in the distribution pattern of immunoreactive nerve elements among the four kinds of antisera. The selective distribution of neuropeptide-containing nerve elements within various nuclei of the medulla oblongata suggests that these neuropeptides may be differentially involved in central neural regulation.

Animals↗
PubMed1996

Galeo-pericranial flaps in the forehead: a study of blood supply and volumes.

Despite their extensive use in anterior cranial base reconstruction, very little is understood about the blood supply of galeo-pericranial flaps derived from the forehead region. The goal of this study was to define the extent of the reliable axial blood supply and to determine the volumes of these flaps. The blood supply to anteriorly based galeo-pericranial flaps depends entirely upon the deep branches and a variable component of the superficial branches of the supraorbital and the supratrochlear vessels. The axial component of the blood supply to these flaps is 20-70 mm. The extent of "random' pattern blood supply distal to this could not be adequately assessed. The volumes of various galeo-pericranial flaps range from 3 to 48 cc. The well vascularized proximal portions of galeo-pericranial flaps may well serve the reconstructive needs of the anterior cranial base. Use of more distal portions of these flaps should be undertaken with caution. Some increase in bulk and vascularity may be achieved if the pericranial and the galeal-frontalis myofascial flaps are harvested as a single unit, the composite galeal-frontalis-pericranial flap. Due to the vascular and volume limitations of galeo-pericranial flaps, consideration should be given to the use of microvascular free tissue transfers in instances where large soft tissue defects and a large "dead space' occur.

Angiography↗
PubMed1996

Effect of insulin on in vitro development of tetraploid mouse embryos.

The effect of insulin on in vitro development of early stage tetraploid mouse embryos was examined. Tetraploid embryos were produced at the 2-cell stage by treatment with cytochalasin B for 12 hr, then they were cultured with M16 medium containing 1 microM insulin. Although insulin had no effect on the embryos until 72 hr after hCG injection, at 96 hr the number of cells of insulin (+) tetraploid blastocysts increased 20.2% more than insulin (-) tetraploid embryos. The increase in the number of cells mainly depended on the inner cell mass (ICM), in which insulin (+) cells increase 76.3% more than insulin (-) cells. These effects of insulin on tetraploid embryos were comparable with those on diploid embryos. The present results suggested that the effect of insulin on the cell proliferation of early stage embryos was not affected by tetraploidy, but the increased number of cells in tetraploid blastocysts was significantly smaller than that in diploid embryos.

Animals↗
PubMed1996

Analysis of mandible of newly developing strain of Japanese white rabbit (Nib:JWNS).

In the present paper, we applied analysis of the mandible to a new strain of Japanese White rabbit being developed (Nib: JWNS), at 5th and 8th generations (F5 and F8), and evaluated the process of establishment, making comparison with the parent colonies (I, K and L), and other established JW colonies (A, E, O and R). The mandibles were measured at 12 sites and the data obtained were calculated by principal component analysis and discriminant analysis. As a result of principal component analysis, the parent colonies were found to be close to one another with intermediate size of the mandible and height of condyloid and angular processes, but in F5 and F8 the mandibles were slightly shorter in height and different from those in the parent colonies. On the other hand, results of discriminant analysis revealed that mandibles were discriminated correctly 100% in colonies A, O and R, and 90% in E and I. Colonies A, O, R, E and I were therefore regarded as established strains. In the developing colonies, the discriminant rate was 70% in F5 and 80% in F8. One mandible from F5 and two from F8 were wrongly classified to the parent colony L, which was the lowest discriminant rate among the colonies examined (61.5%). The results of both statistical analyses suggest that the JWNS are almost established at 8th generation as a new strain.

Animals↗
PubMed1996

Skeletal malformations caused by the Dh (Dominant hemimelia) gene in mice.

Morphological characterization of the skeletal malformations caused by the Dh gene was carried out. Skeletal preparations from newborn mice of Dh/Dh, Dh/+ and +/+ genotypes, and adult Dh/+ mice were examined. The Dh gene induced skeletal deformities at the axial regions from the thorax to the tail. Attachment of the ribs to the sternum was sometimes irregular, and normal segmentation of the sternum was also disrupted. Abnormal fusion of the ventral part of the rib was observed in some cases. Lumbar vertebrae were fewer in number and abnormal in shape. Although it was rare, a curled tail was also observed due to distortion of the caudal vertebrae.

Abnormalities, Multiple↗