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Biomedical subjects

K Fukuta

Publications and source records attributed to K Fukuta.

At least 73 records · Page 4Linked to original sources
PubMed1994

Development of early-stage embryos of the Japanese field vole, Microtus montebelli, in vivo and in vitro.

Although ovulation could be easily induced in the Japanese field vole by administering pregnant mares' serum gonadotrophin and hCG, the number of embryos obtained varied from 1 to 47 (mean, 9.6). One-cell embryos were small (57.8-63.3 microns in diameter; mean, 61.0 microns) compared with those in other mammals. Development of the preimplantation vole embryos in vivo was similar to that of mouse embryos. The first cleavage occurred between 24 and 26 h after mating. The second cleavage was between 46 and 52 h after mating, and subsequent cleavages occurred at about 12 h intervals. Blastocysts were clearly observed in the uterus 4 days after mating. Vole embryos could be cultured in vitro from the late two-cell to the blastocyst stage in M16 medium. However, development of one-cell and early two-cell embryos in vitro was limited, and few cleaved beyond the four-cell stage. Eliminating sodium pyruvate from M16 medium significantly improved the development of early two-cell embryos into blastocysts (P < 0.05). The Japanese field vole may be a useful experimental animal for reproductive biology, comparable with the mouse.

Animals↗
PubMed1994

Identification of sublines of inbred strains of mice and assessment of genetic relationships between substrains or sublines by DNA fingerprinting.

Identification of substrains or sublines of inbred mice and assessment of genetic relationships among them were performed on the basis of DNA fingerprinting using M13 phage DNA as a probe. We used eight C57BL/6 sublines (J parallel Jcl, J parallel Jms, J parallel Slc, J parallel Nrs, J parallel Yok, Jah, N parallel Crj, N parallel Jcl) and eleven C3H/He sublines, (J, J parallel Jcl, J parallel Yok, J parallel Nrs, J parallel Jms, N, N parallel Jcl, N parallel Crj, Slc, Jah, Nrs). Two kinds of restriction endonucleases (HinfI and PstI) were used. It was found that: 1) DNA fingerprint within each subline showed identical patterns. 2) Most sublines of C57BL/6 and C3H/He could be identified using DNA fingerprinting with HinfI except between N parallel Crj and Slc, and among J, J parallel Nrs and J parallel Yok in C3H/He. DNA fingerprints with PstI endonucleases showed low polymorphic banding patterns. 3) A dendrogram constructed from DNA fingerprint patterns reflected generally the genealogy of the sublines used. 4) DNA fingerprinting, therefore, seemed to be suitable for the genetic monitoring and assessment of genetic relationships among sublines of inbred mice having close relationships.

Animals↗
PubMed1994

Arteriovenous fistula formation after punch graft hair transplantation in the frontal region.

A case of arteriovenous fistula formation following punch hair grafting is presented. This is indeed a potential complication of a hair plug transplantation procedure in both recipient and donor sites. Surgical excision of the fistula in the frontal or midline scalp region requires resection of the overlying skin because the involved vessels lie within the subdermal plexus.

Adult↗
PubMed1993

Orbital neurofibromatosis with enophthalmos.

Two patients with orbital neurofibromatosis associated with enophthalmos are presented. Assessment using 3D-CT scan shows an increase in the size of the orbital cavity and an enlargement of the inferior orbital fissure, which allows orbital fat to prolapse into the infratemporal fossa, causing enophthalmos.

Adult↗
PubMed1993

Efficacy of cycled hyperinflation for rapid tissue expansion.

Temporary hyperexpansion at each filling session has previously been confirmed to increase the inflation volume in a conventional expansion procedure. This study employed eight young pigs to evaluate the effect of hyperinflation of this type in rapid expansion performed on 10 consecutive days. Hyperinflation to 120 mmHg for 4 minutes and deflation to 40 mmHg for 2 minutes was repeated five times on the experimental side. This cycled hyperinflation was found to increase the filling volume by 49 percent when compared with the contralateral side, which was not cycled or hyperinflated (control) (p < 0.01). The increase in surface area of the entire skin over the balloon was 178.1 percent in the hyperinflation group and 132.8 percent in the controls (p < 0.01). The actual expansion in surface area was not significantly different: 44.4 percent in the hyperinflation group and 45.7 percent in the control group. The additional gain of skin by cycled hyperinflation was the result of recruitment. The control group required 5 more days to achieve the same amount of skin but resulted in more true expansion and less recruitment. It is concluded that the cycled hyperinflation technique may shorten the time period of the whole reconstruction procedure but may produce an aesthetic deformity and flap necrosis.

Animals↗
PubMed1993

Morphometric profiles of the mandible of SMXA recombinant inbred strains of mice and strain identification on the basis of mandible measurements.

SMXA recombinant inbred (RI) strains were derived from the F2 generation of a cross between two progenitor inbred strains, A/J and SM/J, which differ considerably with respect to many characters. In order to determine the morphometric profiles of the mandible of SMXA RI strains and to identify these strains, principal component and discriminant analyses (mandible analysis) were carried out using 11 mandible measurements. Principal component analysis revealed that the mandibles of each strain have their own characteristic size and shape. The RI strains, however, were roughly divided into 15 groups based on the morphometric profile of their mandibles. Discriminant analysis showed the probability of erroneous discrimination to be 6.49% (20/308) for the males and 8.06% (27/335) for the females. In both sexes, most of the erroneous discrimination (13 in the male, 17 in the female) occurred between RI strains having comparatively similar morphometric profiles. This suggested that all of the SMXA RI strains examined could be regarded as genetically homogeneous within each strain.

Animals↗
PubMed1993

Identification of inbred strains of mice and genetic relationships between strains as assessed by DNA fingerprinting.

Strain identification and the assessment of genetic relationships among inbred strains of mice were examined by DNA fingerprinting using M13 phage DNA as a probe. We used 8 inbred strains (NC/Jah, DDD/Jah, DSD/Jah, RR/Jah, SS/Jah, C3H/HeJah, C57BL/6 Jah and C57BL/6CrSlc) and coisogenic (NC-brp) as well as congenic (C57BL/6-bg) strains. DNA fingerprints using M13 phage DNA as a probe revealed identical patterns within strains. Bands due to new mutations in minisatellite regions within each strain were not observed. The banding patterns were strain-specific. Thus, DNA fingerprinting seemed to be suitable for genetic monitoring of mice. A dendrogram constructed with difference values calculated from DNA fingerprint patterns showed that relationships among strains reflected the history of these strains, so DNA fingerprinting could also be effectively used to assess the relationships between inbred strains of mice.

Animals↗
PubMed1993

[Adrenocortical zonation in the laboratory Japanese field vole (Microtus montebelli)].

Adrenocortical zonation in the laboratory Japanese field vole (Microtus montebelli) was investigated histologically with special attention to the sex and species specific differences. The whole cortex and zona reticularis showed clear sex differences. They were thicker in females than in males. In this respect the vole was similar to the mouse and rat, but different from the Syrian hamster and mastomys. Male cortices were characterized by thick z. fasciculata and meagre z. reticularis, while both zones were thick in females. The z. fasciculata in both sexes and z. reticularis in females seemed to be divided into two sublayers by the cellular arrangement. No distinctive additional zones were identified. The histological observations indicated that the Japanese field vole might have interesting endocrinological characteristics and serve for studying the mechanism of the zone formation in the mammalian adrenal cortex.

Adrenal Cortex↗
PubMed1993

Establishment of inbred strain of long-haired golden hamster.

Features of a long-haired mutant and inheritance of mutation were investigated in the golden hamster (Mesocricetus auratus). The hair of adult long-haired hamsters was longest at the rump and flanks (approximately 70 mm) and was also unusually long at the neck (45 to 50mm). The hair length of males was more striking than that of females. Mating experiments indicated that an autosomal recessive gene is responsible for the inheritance of long hair. An albino long-haired hamster strain was established by continuous full-sib mating from F2 hybrids, descendants of (acromelanic albino x agouti long-haired) F1 progeny, and genetic homogeneity was confirmed by DNA fingerprinting. The long-haired strain was characterised by the fact that males grew larger than females, in contrast to the other strains of hamsters.

Animals↗
PubMed1992

Purification and characterization of glycerate kinase from a serine-producing methylotroph, Hyphomicrobium methylovorum GM2.

The glycerate kinase of a serine-producing methylotroph, Hyphomicrobium methylovorum GM2, was purified to complete homogeneity and characterized, the first time for an enzyme from a methylotroph. The enzyme was a monomer with a molecular mass about 41-52 kDa. The enzyme was stable against heating at 35 degrees C for 30 min at pH values over 6-10. Maximum activity was observed at pH 8.0 and around 50 degrees C. The Km values for D-glycerate and ATP were 0.13 mM and 0.13 mM, respectively. The enzyme showed high specificity for D-glycerate, and was activated by potassium and ammonium ions. The reaction product of the enzyme was identified as 2-phosphoglycerate.

Bacteria↗
PubMed1992

Role of perivenous areolar tissue in the viability of venous flaps: an experimental study on the inferior epigastric venous flap of the rat.

This study was performed to investigate how the perivenous areolar tissue affects survival of the rat inferior epigastric venous flap model designed by Yuen and Leung (1991). Five groups of flaps were studied; group A--flap based on an inferior epigastric vein and areolar tissue; group B--flap with a skeletonised vein; group C--control, nonvascularised flap; group D--flap based on perivascular areolar tissue alone; group E--flap with a skeletonised artery and vein. Each group included 40 flaps; 20 of them had a silicone sheet placed under the flap, the other 20 did not. All flaps of group E survived. The success rate of group A with and without a silicone sheet was 60% and 90% respectively. All flaps of the other groups (B, C, D) necrosed. Histological examination of the pedicle showed that many minute vascular channels (single-cell-layered capillaries) were present apart from the inferior epigastric vein. This result confirms the importance of the perivenous areolar tissue in perfusion of the skin island, at least, in the inferior epigastric venous flap in the rat.

Animals↗
PubMed1992

The directions of static skin tensions in the face: their roles in facial incisions.

The circular excisions of facial skin lesions were performed in 202 sites on 126 patients. The shapes of the resultant defects were observed to identify the directions of skin tensions in a static state. The round shapes remained in the forehead, temple, and nose. In the other areas of the face, the wounds were stretched in certain directions and became elliptical. The orientations of the facial static tensions were identical to the wrinkle lines in many facial areas. It is suggested that the wrinkle lines show the optimal directions of selective incisions in most facial areas except for the medial canthus and upper and lower lips.

Adolescent↗
PubMed1992

The viability of revascularized calvarial bone graft in a pig model.

This study compared the vascularity and resorption of calvarial bone flaps based on an undisturbed pedicle and on a previously (4 weeks) detached pedicle of the superficial fascia (galea) and periosteum and free calvarial bone grafts. Nine adult pigs were used, in three of which a silicone rubber compound was injected intravascularly immediately after the transfer confirmed the vascularity of both pedicled bone flaps. In six pigs, volume changes were assessed intraoperatively by a water displacement method and also 12 weeks postoperatively. Both pedicled bone flaps preserved their original volume, whereas free skull grafts showed approximately 50% of volume loss (p less than 0.001). Decalcified hematoxylin and eosin sections of the specimens obtained 12 weeks postoperatively showed a normal calvarial appearance in both pedicled bone flaps and extensive fibrous tissue infiltration into free grafts. It is suggested that a previous detachment of galea and periosteum does not interfere with the use of vascularized calvarial bone graft, which may provide a more predictable result than a free bone graft.

Animals↗
PubMed1992

Comparison of inorganic bovine bone mineral particles with porous hydroxyapatite granules and cranial bone dust in the reconstruction of full-thickness skull defect.

Twenty adult rabbits were used to evaluate the biocompatibility and osteoconductivity of Bio-Oss, an inorganic bovine bone mineral, in the reconstruction of full-thickness skull defects. Skull defects were treated with either autogenous bone dust, porous hydroxyapatite granules, Bio-Oss particles, or were left untreated as controls. Histological examination of decalcified sections showed incorporation of Bio-Oss into the host tissue without a significant inflammatory reaction. Measurement of the profile area occupied by the bone revealed that Bio-Oss, hydroxyapatite, and the control had the same amount of bone ingrowth, whereas autogenous bone dust produced a greater amount of bone (p < 0.01). We conclude that Bio-Oss, like porous hydroxyapatite, has sufficient osteoconductive properties and can also be used as a bone substitute material.

Animals↗
PubMed1992

Inhibition by fibrin coagulation of lung cancer cell destruction by human interleukin-2-activated killer cells.

We examined the effect of fibrin coagulation on tumor cytotoxicity mediated by human lymphokine (IL-2)-activated killer (LAK) cells. LAK cells were induced from peripheral blood mononuclear cells (MNC) by culture with recombinant IL-2 for 4 or 5 days, and LAK cell-mediated cytotoxicity against tumor cells was assessed by 51Cr release assay in the presence or absence of plasma from normal subjects and lung cancer patients. Plasma did not affect the phase of induction of LAK activity by IL-2, but dose-dependently inhibited the effector phase of LAK cell-mediated cytotoxicity against Daudi cells. Similar inhibition of LAK cell-mediated cytotoxicity was observed on pretreatment of Daudi cells and human lung cancer cell lines with human fibrinogen plus thrombin. A parallel relationship was found between the amount of fibrinogen in plasma of lung cancer patients and inhibition of LAK cytotoxicity. This inhibition was reduced by addition of anticoagulants (heparin or argatroban). These findings suggest that fibrin coagulation on tumor cells protects them from LAK cell-mediated tumor cytotoxicity in malignant lesions and that a combination of an anticoagulant drug and IL-2/LAK therapy may be effective for treatment of lung cancer patients.

Aged↗
PubMed1992

Changes in the level of plasma cortisol, progesterone and total testosterone in developing hairless dogs.

Changes in the levels of plasma cortisol, progesterone and total testosterone were examined in developing hairless and haired dogs. Cortisol levels in the hairless dogs seemed to be higher than those in haired dogs within the age of 4-5 weeks. No apparent changes were seen in the level of plasma progesterone between the groups of hairless females and haired females. Total testosterone levels in hairless males showed to be significantly lower than those in haired males at the age of 13-21 weeks.

Animals↗
PubMed1992

Lymphocyte blastogenesis in hairless dogs following stimulation by various mitogens.

Lymphocyte blastogenesis in hairless descendants of Mexican hairless dogs was examined using the following mitogens: phytohemagglutinin (PHA-M), Concanavalin A (Con A), lipopolysaccharide (LPS) and pokeweed mitogen (PWM). Blastogenetic responses to these mitogens were measured by glucose consumption test (GCT) and compared with those of haired beagle dogs. The response to PHA-M was significantly less in the hairless dogs than in the beagles. No significant differences in the responses to Con A, PWM and LPS were recognized. These results indicated T-cell dysfunction in the hairless dogs, coinciding with our previous work showing reduction of the delayed-type hypersensitivity reaction and early degeneration of the thymus.

Animals↗