• Korean Journal of Plant Resources
• /
• v.16 no.2
• /
• pp.160-167
• /
• 2003

In order to investigate the effects of developmental stage of embryos and plant growth regulators on mass production of Zantedeschia spp. Southern Light, immature zygotic embryos of Zantedeschia spp. Southern Light were cultured on Murashige and Skoog(1962) basal media or containing 2,4-D, NAA and BA. Globular embryos did not grow on any of the 2,4-D, NAA and BA combinations. The most suitable stage of immature zygotic embryo culture on the induction callus and multiple shoot was at early cotyledonary embryo stage, and at this stage of embryos were germinated up to 87.5%. The whitish watery callus and yellowish compact nodular callus produced on all 2,4-D, NAA and BA media. The best combination for inducing embryogenic callus was 0.5 mgL NAA and 1.0 mg/L BA. Whitish watery calli have been subcultured for more than 8 months and have retained their producing ability, Plant regeneration was only obtained by direct shoot development and yellowish compact nodular calli. Abundant plantlets were regenerated from cotyledonary stage of embryo culture on MS medium supplemented with 0.5 mg/L NAA and 1.0 mg/L BA. Supplementation of the media with 10％ coconut water showed as the best concentration for plant differentiation from direct developed of shoots. The number of regenerated plants from one embryo could be seperated 25-35s plantlets. All yellowish compact callus-derived plantlets were transferred to pots containing a mixture of vermiculite, perlite and sand(1:1;1 v/v) and 100% of divided plantlets were phenotypically normal.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.3
• /
• pp.867-872
• /
• 2012

Background: $FOXP3^+$ regulatory T cells (Tregs) inhibit effector T cell functions and are implicated in tumour progression. However, together with microvessel density (MVD) they remain controversial prognostic predictors for renal cell carcinoma (RCC), and potential associations have yet to be determined. The objective of this study was to determine the prognostic significance of Tregs and MVD and their potential relationship in RCCs. Design: Paraffin-embedded tissues from 62 RCC patients were analysed using immunohistochemistry to detect $FOXP3^+$ lymphocytes, and double immunohistochemistry to detect different microvessel types in the tumour interior, rim and normal kidney tissue, and their correlation with clinicopathological characteristics. Survival analysis was also performed. Results: The presence of $FOXP3^+$ cells in the tumour interior or the rim showed no correlation with death from RCC and other pathological characteristics. Negative correlations were noted between the immature MVD in the tumour interior or the rim and tumour size, tumour stage and overall survival; however, there was no correlation with the nuclear grade or pathological type. A positive correlation between $FOXP3^+$ Tregs and immature MVD (r=0.363, P=0.014) and mature MVD (r=0.383, P=0.009) was confirmed in the tumour interior. However, there was no correlation between $FOXP3^+$ Tregs and mature MVD (r=0.281, P=0.076) or immature MVD (r=0.064, P=0.692) in the tumour rim. Conclusions: In this study, a positive correlation between the presence of $FOXP3^+$ Tregs and immature and mature MVD in RCC was confirmed, which suggests a link between suppression of immunity, tumour angiogenesis and poor prognosis.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.749-756
• /
• 2013

In this paper, we consider a diffusive delayed predator-prey model with Beddington-DeAngelis type functional response under homogeneous Neumann boundary conditions, where the discrete time delay covers the period from the birth of immature preys to their maturity. We investigate the global existence of nonnegative solutions and the long-term behavior of the time-dependent solution of the model.

• Kyungpook Mathematical Journal
• /
• v.47 no.1
• /
• pp.31-56
• /
• 2007

In this paper, we consider a delay differential equation model of two competing species with harvesting of the mature and immature members of each species. The time delay in the model represents the time from birth to maturity of that species, which appears in the adults recruitment terms. We study the dynamics of our model analytically and we present results on positivity and boundedness of the solution, conditions for the existence and globally asymptotically stable of equilibria, a threshold of harvesting, and the optimal harvesting of the mature populations of each species.

• Proceedings of the Korean Society of Applied Entomolohy Conference
• /
• 2002.05a
• /
• pp.61-61
• /
• 2002

• Clinical and Experimental Reproductive Medicine
• /
• v.30 no.4
• /
• pp.333-340
• /
• 2003

Objective: This study was performed to examine the maturation and the development to the blastocyst stage of immature oocytes collected from patients with high risk of ovarian hyperstimulation syndrome (OHSS). Materials and Methods: Cumulus-oocyte complexes (COCs) were collected following only HCGpriming for non stimulated IVF-ET cycles of the patients. At the time of oocyte collection, COCs were classified into three groups in accordance with their appearance (Group I: oocytes with dispersed cumulus cells; Group II: oocytes with compacted cumulus cells; Group III: oocytes with sparse cumulus cells). The in vitro maturation and blastocyst development rates of the COCs were compared among these groups. From August 2001 to June 2002, 48 IVM/IVF-ET cycles from 42 patients (mean age: $32.4{\pm}3.8$ years) were performed. To prevent the occurrence of OHSS, the patients were primed with 10, 000 IU HCG alone 36 h before oocyte collection without gonadotropin stimulation. Oocytes were aspirated on cycle days from 7 to 13. The normal COCs were classified into three groups according to their appearance. The aspirated immature oocytes were cultured in YS maturation medium containing 30% (v/v) human follicular fluid (HFF), 1 IU/ml FSH, 10 IU/ml HCG and 10 ng/ml rhEGF. Fertilization was induced by intracytoplasmic sperm injection (ICSI). All zygotes were co-cultured with cumulus cells in $10{\mu}l$ YS medium containing 10% HFF until day 7 after oocyte collection. Blastocyst transfer was performed on day 5 after ICSI. Results: Th e mean number of oocytes cultured in the IVM/IVF cycles was $24.7{\pm}10.6$. Of 1185 COCs, those assigned to Group I, II and III were 470 (39.7%), 414 (35.0%) and 301 (25.4%), respectively. The maturation rate (94.5%, 444/470, p<0.05) in Group I was significantly higher than those of Group II (62.8%, 260/414) and Group III (73.1%, 220/301). Especially, 30.9% of COCs in Group I (145/470) was matured on the day of oocyte aspiration. There were no differences in the rates of fertilization and cleavage among the three groups. The development rate to the blastocyst stage in Group I (54.6%, 206/377, p<0.05) was also significantly higher than those in Group II (33.0%, 68/206) and Group III (30.1%, 52/173). Twenty-four clinical pregnancies (50.0%) was obtained and 22 pregnancies (45.8%) are ongoing. Implantation rate in the present study was 24.6%. Conclusion: These results suggest that there is a positive correlation between the appearance of COCs and the developmental competence of the immature oocytes in non stimulated IVM/IVF cycles.

• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.2
• /
• pp.253-259
• /
• 1997

Objective: To investigate effects of cryoprotectant and cryopreservation on the chromosome of the human immature oocytes. Design: Intact cumulus-enclosed immature oocytes were collected from unstimulated ovaries and divided into three groups, such as no treatment as control (group 1), only 1,2-propanediol (PROH)-treated (group 2), and cryopreserved oocytes (group 3). Oocytes in group 1, 2, and survived oocytes after cryopreservation in group 3 were cultured for 48 hours. Setting: Infertility Medical Center at the CHA General Hospital, Seoul, Korea. Patients: Oocytes were obtained from Patients undergoing gynecological surgery. Main Outcome Measures: Maturation rate, abnormality in chromosomes by fluorescence in situ hybridization (FISH). Results: There was no effect of PROH only treatment on the chromosomal abnormalities in group 2 compared to control oocytes (41.4% and 31.8%, respectively). Whereas significantly increased abnormalities in chromosome (77.8%) were found in group 3. Conclusions: Human oocytes matured in vitro after cryopreservation at the germinal vesicle (GV) stage showed increased incidence of chromosomal abnormalities. These abnormalities may impair the capacity for further development of the embryos derived from frozen-thawed oocytes.

• Clinical and Experimental Reproductive Medicine
• /
• v.40 no.1
• /
• pp.7-11
• /
• 2013

Objective: We evaluated the fertilization potential of immature oocytes obtained from controlled ovarian hyperstimulation cycles of patients undergoing ICSI. Methods: We retrospectively analyzed 463 ICSI cycles containing at least one immature oocyte at oocyte denudation. ICSI was performed on mature oocytes at oocyte denudation (metaphase-II [MII] oocytes) and the oocytes that extruded the first polar body between oocyte denudation and ICSI (MI-MII oocytes). Fertilization and early embryonic development were compared between MII and MI-MII oocytes. To investigate the pregnancy potential of MI-MII oocytes, the pregnancy outcome was analyzed in 24 ICSI cycles containing only immature oocytes at retrieval. Results: The fertilization rate of MI-MII oocytes (37.0%) was significantly lower than that of MII oocytes (72.3%). The rates of delayed embryos and damaged embryos did not significantly differ. Eighty-one immature oocytes were retrieved in 24 cycles that retrieved only immature oocytes and 61 (75.3%) of them were in the MI stage. ICSI was performed on 36 oocytes (59.0%) that extruded the first polar body before ICSI and nine MI-MII oocytes (25.0%) were fertilized. Embryo transfers were performed in five cycles. Pregnancy was observed in one cycle, but it ended in biochemical pregnancy. Conclusion: In ICSI cycles, oocytes that extruded the first polar body between denudation and ICSI can be used as a source of oocytes for sperm injection. However, their fertilization and pregnancy potential are lower than that of mature oocytes. Therefore, ovarian stimulation should be performed carefully for mature oocytes obtained at retrieval, especially in cycles with a small number of retrieved oocytes.

• Asian-Australasian Journal of Animal Sciences
• /
• v.4 no.1
• /
• pp.1-5
• /
• 1991

Responsiveness of the testis to pregnant mare's serum gonadotropin (PMSG) was studied in immature Nili-Ravi buffalo bulls. Four month old bull calves weighing between 66 to 100 kg raised under uniform condition, were treated with 1000 IU PMSG or vehicle, daily, for six days. PMSG induced an increase in the size of the testis, enlargement of the seminiferous tubules and activation of the spermatogonia. The number of differentiated Leydig cells in the testis of gonadotropin treated animals increased considerably over that of the control testes. A significant increase in plasma testosterone concentrations was observed 24 h following the first injection of PMSG and the levels continued to increase until day 6. In vehicle treated animals plasma testosterone levels remained more or less at pretreatment values. The data suggest that buffalo bull testis is functionally responsive to gonadotropin at an early stage of prepubertal development.

• Molecules and Cells
• /
• v.41 no.7
• /
• pp.613-621
• /
• 2018

The capacity of differentiation of human pluripotent stem cells (hPSCs), which include both embryonic stem cells and induced pluripotent stem cells, into cardiomyocytes (CMs) in vitro provides an unlimited resource for human CMs for a wide range of applications such as cell based cardiac repair, cardiac drug toxicology screening, and human cardiac disease modeling. However, their applicability is significantly limited by immature phenotypes. It has been well known that currently available CMs derived from hPSCs (hPSC-CMs) represent immature embryonic or fetal stage CMs and are functionally and structurally different from mature human CMs. To overcome this critical issue, several new approaches aiming to generate more mature hPSC-CMs have been developed. This review describes recent approaches to generate more mature hPSC-CMs including their scientific principles, advantages, and limitations.