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Biomedical subjects

K Fukuta

Publications and source records attributed to K Fukuta.

At least 55 records · Page 3Linked to original sources
PubMed1996

High lethality of F1 (Dh/+) male mice from the cross between DDD female and DH (Dh/+) male.

The present study demonstrates the incidence of high lethality of F1 (Dh/+) male mice, the offspring of DDD females and inbred DH (Dh/+) males. Among the newborn pups, the numbers of F1 (Dh/+) males are comparable to those of mice having other genotypes (+/+ male, Dh/+ female and +/+ female), but many F1 (Dh/+) males died before weaning. On the other hand, among the F1 mice from the cross between DH (Dh/+) females and DDD males, there are no biased numbers of Dh genotype pups. These results suggest the existence of defects in the interaction between the male derived Dh gene and the genetic traits of the DDD female.

Abnormalities, Multiple↗
PubMed1996

Isolation of a germline-transmissible embryonic stem (ES) cell line from C3H/He mice.

We have isolated three embryonic stem (ES) cell lines from C3H/He mice using mouse STO cells as a feeder layer. One ES cell line (H-1) was male, and two (H-2 and H-3) were female, as determined by polymerase chain reaction, in situ hybridization, and karyotype analyses. All were immunocytochemically reactive with a C3H strain-specific antibody. Injection of cells from the female ES H-3 line into C57BL/6 blastocysts yielded four chimeras with slight coat color chimerism. All chimeras were male, and as expected, no germline-transmission was observed. By contrast, when male ES H-1 cells were injected into the perivitelline space of 8-cell C57BL/6 embryos, one male mouse with overt coat color chimerism was recovered, and it produced ES H-1-derived offspring exclusively. This germline-transmissible C3H/He cell line represents a novel addition to those ES lines currently employed for gene manipulation studies of development.

Animals↗
PubMed1996

Unique pits on the erythrocytes of the lesser mouse-deer, Tragulus javanicus.

The lesser mouse-deer, Tragulus javanicus, is the smallest living ungulate and it possesses the smallest erythrocytes amongst mammalian species. We observed pits on its erythrocytes by scanning electron microscopy. They were 68-390 nm in diameter (135 +/- 65 nm) and appeared in 12.8% of erythrocytes examined. They represent unique structures that have not previously been reported physiologically or pathologically.

Animals↗
PubMed1995

Incomplete development of the spleen and the deformity in the chimeras between asplenic mutant (Dominant hemimelia) and normal mice.

The semidominant gene Dh (Dominant hemimelia) induces skeletal and visceral abnormalities of various degrees and failure of the spleen in mice. The homozygous individual (Dh/Dh) seems to be lethal. The present experiment was designed to investigate the ability Dh cells to form a spleen and the genesis of the hind limb malformations by Dh/Dh and Dh/+ cells in chimeric mice. The Dh/Dh and Dh/+ embryos were produced in the F2 progeny of a cross between inbred strains of Dh/+ and DDD mice. They were aggregated with C3H/He or C57BL/6 embryos to make chimeras. Identification of Dh/Dh or Dh/+ embryos was carried out by Pep-3, and chimerism was analyzed by Gpi-1. Of 25 chimeras carrying the Dh gene, four mice formed a small spleen, two mice had a vestigial spleen, and the others no spleen. The tissues of the incompletely developed spleens were normal histologically and Dh cells were involved in the tissues of the spleen. In the chimeric mice, hindlimb malformation by the Dh gene was reduced in severity and the lethality of the homozygote (Dh/Dh) was rescued.

Animals↗
PubMed1995

Reconstruction of the anterior cranial base with the galeal frontalis myofascial flap and the vascularized outer table calvarial bone graft.

Reconstruction of the anterior cranial base after tumor extirpation must seal off the cranial cavity from the upper respiratory tract. The key to success is to use vascularized materials for the structural support of the brain. From October 1989 to July 1992, 10 patients underwent anterior cranial base reconstruction after basicranial tumor resection; the lesions were four meningiomas and six malignant tumors of the ethmoid, maxilla, and orbit. The malignant tumors included four recurrent tumors that had been previously treated by a transfacial approach. After tumor extirpation, the resultant bony defects in the anterior cranial base, involving the orbital roof as well as the cribriform plate, ranged from 4 x 3 to 6 x 7 cm in size. The materials used in reconstruction were the galeal frontalis myofascial flap and the outer table calvarial bone flap, which is based on the temporoparietal galeal flap. Both materials are known to have rich blood supplies. These flaps make a reliable separation between the cranial cavity and the respiratory tract in three layers: the galeal frontalis myofascial flap, the vascularized calvarial bone, and the temporoparietal galea. Postoperative complications included one subcutaneous hematoma and one temporary cerebrospinal fluid rhinorrhea. We think this reconstructive technique will be useful in selected circumstances, especially after resection of a recurrent malignant tumor.

Adult↗
PubMed1995

Production of term offspring by in vitro fertilization using old mouse spermatozoa.

We successfully produced offspring of old male BDF1 mice using in vitro fertilization. Although 7 old male mice (33 months of age) were infertile and revealed frequent degeneration in the seminiferous epithelia, 4 of them had spermatozoa in the caudae epididymides. The IVF rate of their sperm with eggs from young ICR mice was very high (82.0%). The production rate of offspring was also satisfactory (61.6%). The present study indicates that the IVF method is useful for producing offspring of aged male mice.

Aging↗
PubMed1995

In vitro fertilization and embryo development of Japanese field voles (Microtus montebelli).

Optimal conditions for in vitro fertilization of Japanese field voles (Microtus montebelli) were analysed. The medium used was a modified Krebs-Ringer bicarbonate devised for in vitro fertilization in rats. Ovulated eggs and epididymal spermatozoa were co-incubated in vitro at 37 degrees C under 5% CO2 in air for 6 h, and the eggs were fixed with 2.5% (w/v) glutaraldehyde, stained with 0.25% (v/v) acetolacmoid and examined for evidence of fertilization at the pronuclear stage. Although the fertilization rate with spermatozoa preincubated at 1-2 x 10(8) cells ml-1 for 2 h was very low (1-13%), it was significantly increased (43-51%, P < 0.05) when spermatozoa were preincubated at a lower concentration (1-2 x 10(7) cells ml-1). Furthermore, the fertilization rate was significantly higher with 1 mmol hypotaurine l-1 (74.0%) than without hypotaurine (44.4%, P < 0.05). Fertilization rates of spermatozoa preincubated at 1-2 x 10(7) cells ml-1 for 0.5 or 2 h were similar (69.0% and 73.6%), but a longer preincubation (10 h) resulted in a significantly lower fertilization rate (56.8%, P < 0.01). Vole spermatozoa preincubated for 2 h penetrated the zona pellucida 2 h after insemination, and the sperm heads became decondensed 3 h after insemination. At 6 h after insemination, male and female pronuclei were found in most penetrated eggs. When the eggs were left in the fertilization medium without washing and cultured for 96 h after insemination, they developed to two-cell (82.6%), four-cell (60.9%), eight-cell (23.2%) and morula/blastocyst (8.7%) stages in modified Krebs-Ringer bicarbonate supplemented with 1 mmol hypotaurine l-1.

Animals↗
PubMed1995

Preimplantation development of tetraploid mouse embryo produced by cytochalasin B.

Tetraploid mouse embryos usually cease to develop early after implantation, though they can develop to blastocysts. To characterize the failure of development in detail, tetraploid mouse embryos at the preimplantation period were examined as to both their morphology and number of cells. The tetraploid embryos were produced by 12 hr treatment with cytochalasin B (CB) at the 2-cell stage of backcross of (C57BL/6 x C3H/He) F1 x C3H/He. The tetraploid embryos in the preimplantation period exhibited compaction at 72 hr after hCG injection and blastocyst formation at 96 hr, as well as diploid embryos, but the number of cells composing the embryos was significantly smaller than that in the diploid embryos. At the term 60-96 hr after hCG injection, mean cell cycles were 14.03 hr in the tetraploid embryos, but 12.02 hr in the diploid. When tetraploid embryos were transferred into the oviducts of pseudopregnant recipients immediately after CB treatment, the number of cells in tetraploid blastocysts was increased compared with the embryos cultured in vitro, though the number did not reach that of diploid embryos. These results suggested that compaction and blastocyst formation in preimplantation development of tetraploid embryos depended on the time after hCG injection, irrespective of the number of cells or the length of the cell cycle. The lengthening of the cell cycle in tetraploid embryos may be one of the causes of failure in postimplantation development.

Animals↗
PubMed1995

Retinal projections to the subcortical nuclei in the Japanese field vole (Microtus montebelli).

Retinal projections in the Japanese field vole (Microtus montebelli) were determined by anterograde transport of horseradish peroxidase (HRP). Injection of HRP into the unilateral vitreous body demonstrated that the terminal labeling of the optic projections was seen bilaterally in the suprachiasmatic nucleus (SCH), the ventral (GLv) and dorsal (GLd) lateral geniculate nuclei, the intergeniculate leaflet (IGL), the medial pretectal nucleus (NTOM) of the pretectum (PT) and the superficial layer of the superior colliculus (CS), with contralateral predominance, and only contralaterally labeled terminals were found in the lateroposterior thalamic nucleus (LP), the lateral pretectal nucleus (NTOL) of the PT, the dorsal (DTN) and medial (MTN) terminal nuclei of the accessory optic system (AOS). The distribution area of the retinofugal terminals was divided into a three laminar arrangement in the GLd, i.e., layers 1 and 3 and layer 2, received the retinal input from contralateral and ipsilateral eye, respectively, as in arboreal squirrels. The contralateral CS received retinal fibers in the superficial layer, while ipsilateral optic fibers projected sparsely to the stratum opticum of the colliculi. Retinal connections to the DTN and MTN of the AOS were clearly discerned but no lateral terminal nucleus with retinal afferents was found. In addition, the AOS had no inferior fasciculus. These findings indicate that the vole has a contradictory features of a well- and a less-developed sense of vision. Namely, the image forming visual system such as the retino-GLd was as well-developed as in a squirrel, on the other hand, the non-image forming visual system such as the retino-AOS was less-developed as in an insectivore's brain.

Animals↗
PubMed1995

Identification and minisatellite linkage analysis of SMXA recombinant inbred strains of mice by DNA fingerprinting.

SMXA recombinant inbred (RI) strains of mice were produced by systematic inbreeding from the F2 generation of a cross between two progenitor inbred strains, A/J and SM/J, which differ considerably with respect to many characteristics, and consists of 28 inbred strains. In this study, we investigated the applicability of DNA fingerprinting with M13 phage DNA to the identification of these closely related strains. DNA fingerprints of the SMXA RI strains and their progenitors, SM/J and A/J, showed strain-specific patterns, with the same banding patterns within each strain. Linkage analysis by using strain distribution patterns of minisatellite loci with 108 genetic markers containing microsatellites, biochemical and immunological marker genes allowed 23 minisatellite loci to be assigned to 11 chromosomes. The results suggested that DNA fingerprinting with M13 phage DNA is applicable not only for strain identification but also for genetic monitoring of RI strains on almost all chromosomes.

Animals↗
PubMed1995

[Brain deformation caused by hyperplasia molar teeth (macrodonts) in the Japanese field vole (Microtus montebelli)].

Protrusion of hyperplastic upper molar teeth (macrodonts) into the cranial cavity was observed in the Japanese field vole. Protrusions of the upper molars occurred on both sides, but were large on the left than on the right. The teeth invaded the cranial cavity and brain parenchyma. Large concavities on the ventral side of the brain were interposed between the lateral olfactory tract and the optic tract. Invation by one macrodont reached the basal nuclei, hypothalamic and thalamic nuclei. The brain was deformed bilaterally, and nearly the entire olfactory bulb, globus pallidus, internal capsule, and lateral preoptic nucleus, and a portion of the hypothalamus, thalamus and anterior commissure were absent on the left side.

Animals↗
PubMed1994

Role of perivenous areolar tissue and recipient bed in the viability of venous flaps in the rabbit ear model.

This study was performed to investigate the role of perivenous areolar tissue and flap bed in the viability of venous flaps in the rabbit ear model as described by Inada et al. Six groups of flaps were studied: group A--flap based on a proximal vein and areolar tissue; group B--flap based on a proximal venous pedicle which has been skeletonised; group C--flaps based on a proximal vein and areolar tissue sutured over a full thickness skin graft (FTSG), preventing diffusion into the flap; group D--flaps with a skeletonised pedicle sutured over a FTSG; group E--control, non-vascularised flap placed directly on bed; and Group F--control, non-vascularised flap sutured over a FTSG. Groups C and D had 15 flaps and the remaining groups had 10 flaps in each. All flaps in groups A and B had total or partial survival. In group C 4 flaps survived completely, 8 had partial survival and 3 necrosed. Group D had only 2 flaps with partial survival with 13 flaps with total loss. In group E there were 10 flaps with partial survival and none with complete loss. No flaps in group F survived. Histological examination of the pedicle showed small vascular channels present in the areolar tissue surrounding the venous pedicle. This study confirms the importance of the perivenous areolar tissue in the perfusion of the venous skin flap in the rabbit ear model.

Animals↗
PubMed1994

Extradural dead space following cranial bone advancement.

The extradural dead space produced after enlargement of the intracranial space or after reduction of the volume of the intracranial contents persists for an unknown period of time. To investigate this further, an extradural dead space was surgically created by advancement of parietal bones in 9 adult rabbits. By design, there was no connection with the paranasal sinuses. To determine outcome of the dead space, three-dimensional computed tomographic and histological studies were performed. The brain volume decreased in the first 3 months after surgery and remained constant for up to 9 months. The extradural volume increased in the first 4 weeks postoperatively, gradually decreasing in size with time. The brain failed to eliminate the extradural dead space by rearrangement or expansion. An osseous cavity filled with fluid and connective tissue was formed within the dead space. The fluid within it remained, even 9 months after surgery. This could be a potential environment for bacterial invasion if there was a connection with the nasopharynx.

Animals↗
PubMed1994

A cadaver investigation of the blood supply of the galeal frontalis flap.

The vascular anatomy of the galeal frontalis flap was studied in 12 fresh cadavers by an intraarterial dye injection technique. Special attention was directed to the length limit of this flap. The general belief that the galeal frontalis flap has a robust vascularity by means of the supratrochlear and supraorbital arteries was not demonstrated in this study. In the medial half of the forehead, superficial branches of both arteries penetrated the frontalis muscle immediately above the supraorbital rim and ran superficially in the subcutaneous tissue. In the lateral half, some of the superficial branches of the supraorbital artery traveled with the frontalis muscle and anastomosed with the frontal branch of the superficial temporal artery. Deep branches of the supratrochlear and supraorbital arteries showed an axial distribution on the periosteum only for a short distance. One or two branches of the supraorbital artery were found to take a superficial course within the subgaleal layer, pierce the frontalis muscle, and anastomose with the superficial temporal artery. These findings suggest that the galeal frontalis flap should be elevated in the lateral forehead. The preservation of the periosteum with the flap is recommended in order to ensure the temporoparietal extension.

Blood Vessels↗
PubMed1994

Plasminogen activators and plasminogen activator inhibitor 1 in urinary tract cancer.

The plasminogen activation system is considered to play an important role in cancer growth and metastasis. Both plasminogen activators (PAs) and their fast-acting inhibitors are produced in tumor cells and their surrounding tissues. In order to clarify the influence of the existence of malignant tumor in urinary tract on the systemic fibrinolytic activity, we designed a study in which we compared the plasma levels of PAs and their inhibitors between before and after radical resection of tumors. Fourteen patients with renal cell carcinoma and 14 patients with transitional cell carcinoma participated in the study. In both groups, plasma levels of tissue-type plasminogen activator and urokinase-type plasminogen activator before the operation were higher than those 15 days after operation. The plasma level of plasminogen activator inhibitor 1 (PAI-1), however, did not change after the operation in the renal cell carcinoma group, and it decreased slightly in the transitional cell carcinoma group although it was not significant. When these values of the groups with or without metastasis were compared to other organs or lymph nodes, the PAI-1 level before operation was significantly higher in the group with metastasis than that without metastasis. In the three groups divided by the degree of atypia, PAI-1 level in the most atypical group was the highest. These results suggest that the fibrinolytic system in the plasma of cancer patients may play an important role in tumor growth and metastasis.

Carcinoma, Renal Cell↗