Effects of duration of electric pulse on in vitro development of cloned cat embryos with human artificial chromosome vector.

The current applications for cat cloning include production of models for the study of human and animal diseases. This study was conducted to investigate the optimal fusion protocol on in vitro development of transgenic cloned cat embryos by comparing duration of electric pulse. Cat fibroblast cells containing a human artificial chromosome (HAC) vector were used as genetically modified nuclear donor cells. Couplets were fused and activated simultaneously with a single DC pulse of 3.0 kV/cm for either 30 or 60 µs. Low rates of fusion and embryo development to the blastocyst stage were observed in the reconstructed HAC-transchromosomic embryos, when the duration of fusion was prolonged to 60 µs. In contrast, the prolongation of electric pulse duration improved the embryo development and quality in the reconstructed control embryos without HAC vector. Our results suggested that the optimal parameters of electric pulses for fusion in cat somatic cell nuclear transfer vary among the types used for donor cells.

Follicle formation in the canine ovary after autografting to a peripheral site.

This study reports about follicular development on the surface of canine ovarian tissue after autografting under the fascia of the thoracolumbar muscle and about meiotic resumption of follicle-derived oocyte after maturation culture. After ovarian excision from a bitch, each ovary of the pairs was cut approximately into half. The hemi-ovaries were transplanted into the bitch of origin at three different body sites (under the fascia of the quadriceps femoris muscle and the thoracolumbar muscle, and in the deltoid muscle in the scapular region). All grafted ovaries were recovered from the bitch at 35 days post-transplantation. A visible antral follicle was observed on the surface of the ovary grafted under the thoracolumbar fascia. Histological examination revealed viable follicles at different stages of development irrespective of graft site. Most granulosa cells in the follicles at different stages of development expressed proliferating cell nuclear antigen (PCNA). A total of three oocytes were collected from an ovary grafted under the fascia of the thoracolumbar muscle, wherein an oocyte reached metaphase I after maturation culture. This is the first report to demonstrate follicular development and meiotic resumption of oocytes recovered from autografted canine ovarian tissues.

Epidermal growth factor (EGF) receptors in human chorionic gonadotropin-producing tumor: transplantation in nude mice and the effect of EGF on tumor growth.

We examined the presence and characteristics of epidermal growth factor (EGF) receptors in hCG producing tumors (CC-2-JCK) transplanted in female nude mice. We also examined the in vivo effects of EGF on tumor growth. Specific receptors with apparent dissociation constants of 3.89 x 10(-10) and 1.0 x 10(-9) M and binding capacities of 5.96 x 10(-10) and 1.52 x 10(-9) M/mg protein for EGF have been identified in the hCG-producing tumor. [125I]EGF binding to the tumor tissues was time, temperature, and tissue weight dependent and specific. EGF and transforming growth factor-alpha (TGF alpha) competed for [125I]EGF binding, with 50% of the bound [125I]EGF displaced by approximately 0.52 nM EGF and 3.10 nM TGF alpha. TGF beta competed for [125I]EGF binding slightly. Five micrograms of EGF caused an increase in the rate of tumor growth, while 50 micrograms EGF strongly inhibited tumor growth. The concentration of [125I]EGF binding in the tumor treated with low doses of EGF was high, and that in the tumor treated with high doses of EGF was low. These changes in EGF binding were attributable to the changes in the number of high affinity EGF receptors with no significant alteration in binding affinity. In conclusion, the existence of high concentrations of EGF receptors with high affinity and specificity to EGF was demonstrated in an hCG-producing tumor transplanted in nude mice and appeared to be correlated with tumor growth.

Freeze-replica observations of guinea pig middle ear muscles.

The histological characteristics of the middle ear muscles, Musculus tensor tympani and M. Stapedius, of the guinea pig were studied using freeze-fracturing technique. No gap junction was observed but the tight junction was found in the tensor tympani muscle, possibly between muscle cells. No distinct difference was found between the size distributions of the apertures and caveolae on the fracture face of the sarcolemma of the two kinds of muscles.

[Neo-adjuvant chemotherapy with cisplatin, 5-fluorouracil, vindesine in head and neck cancer].

Neo-adjuvant chemotherapy with CDDP combination was introduced into the treatment of advanced head and neck cancer. Twenty-three patients with s.c.c of head and neck were given combination chemotherapy consisting of CDDP, VDS and 5-FU before surgical treatment in our department. CR and PR of this trial in all patients were 4 and 35%, respectively. The WBC nadir occurred around 2 weeks later, but all the patients recovered prior to the next cycle or surgical treatment. Renal dysfunction, nausea, vomiting and depilation were generally mild. VDS is useful as one of the neo-adjuvant drugs for the treatment of head and neck cancer. Long-term observation in connection with this treatment is required.

[Use of a butterfly ventilation tube in the treatment of otitis media with effusion].

Sixty-three ears of 49 patients with serous otitis media were treated making use of butterfly ventilation tube in our 4 hospitals and 1 private office. The average time from intubation to extubation was 9 months and the longest case was 33 months. Main complications were infection and spontaneous extubation. The rate of hearing improvement after tympanostomy was more than 80% in all cases. The frequency of the most improvement was observed in 1kHz on the average. It was cleared that the butterfly ventilation tube was easy to use for the wide age patients and at any clinics. It was concluded that the butterfly ventilation tube was useful as a long-term ventilation tube.

[Synthesis and regulation of growth hormone secretion].

Human growth hormone (hGH) is a single chain, 22 kd-protein with two intramolecular disulfide bonds. The hGH gene is located on chromosome 17 at band q22-q24 and has four introns separating five coding exons. The expression of hGH is restricted to the pituitary and regulated by GHF-1 which binds to the hGH promoter acting in concert with several other more ubiquitous DNA binding proteins. The secretion of hGH is regulated by GH releasing hormone (GRH) and somatostatin. GRH controls GH synthesis by stimulating transcription of GH mRNA while somatostatin determines the timing and amplitude of GH pulses. Pulsatile GH secretion is influenced by a number of neurogenic, metabolic and hormonal factors.

Assessment of canine ovaries autografted to various body sites.

The influence of graft site on the survival of canine follicles and oocytes after autografting was investigated. Hemi-ovaries were autografted to three locations (quadriceps femoris muscle fascia, kidney capsule, and gastrosplenic ligament), and grafted ovaries were recovered (under anesthesia) 28 to 31 d after transplantation. The grafted hemi-ovaries were bisected: one-quarter ovary was used for histological assessment and another quarter for evaluation of oocyte viability. As controls, the remaining fresh hemi-ovaries were used to assess the viability of follicles and oocytes in non-transplanted ovaries. Most follicles in the histological sections of the grafts were classified as primordial or primary follicles. Antral follicles were not observed in the grafts, irrespective of the graft site. The percentages of viable follicles in the sections from control ovaries, and the ovaries grafted to the kidney capsule, the quadriceps femoris muscle fascia, and the gastrosplenic ligament were 17.4, 22.9, 18.3, and 32.4%, respectively. A total of 12 oocytes was recovered from the 15 hemi-ovaries grafted in five bitches, of which five (41.7%) oocytes from the ovaries grafted to the quadriceps femoris muscle fascia and the kidney capsule were cultured for assessment of meiotic competence. Three oocytes were viable but remained in the germinal vesicle stage after 72 h of maturation culture. The quadriceps femoris muscle fascia might be useful for grafting like the kidney capsule, but improvement of follicle survival and meiotic competence of oocytes in the grafts is necessary.

Isotopic dependence of the giant monopole resonance in the even-A 112-124Sn isotopes and the asymmetry term in nuclear incompressibility.

The strength distributions of the giant monopole resonance (GMR) have been measured in the even-A Sn isotopes (A=112-124) with inelastic scattering of 400-MeV alpha particles in the angular range 0 degrees -8.5 degrees . We find that the experimentally observed GMR energies of the Sn isotopes are lower than the values predicted by theoretical calculations that reproduce the GMR energies in 208Pb and 90Zr very well. From the GMR data, a value of Ktau = -550 +/- 100 MeV is obtained for the asymmetry term in the nuclear incompressibility.