• The Journal of the Korean dental association
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• v.12 no.12
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• pp.925-927
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• 1974

It has been said that thyroid gland controls the function of salivary gland and vice versa. In an attempt to investigate the role of submaxillary gland on the function of thyroid gland, the authors have observed the changes of thyroid gland histologically and histochemically at 70 days after removal of submaxillary gland in rats. The results are as follows: 1. There are no significant changes of thyroid cells after submaxillary gland removal. 2. The colloidal concentration of thyroid follicles is markedly decreased after submaxillary gland removal. 3. The colloids of thyroid follicles show intensive reaction to PAS staining in intact rats, but moderate or minimal reaction in submaxillary removal rats.

• Environmental Analysis Health and Toxicology
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• v.19 no.3
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• pp.251-259
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• 2004

Xenoestrogens are chemicals with diverse structure that mimic estrogen. Bisphenol A, a monomer of polycarbonate and epoxy resins, has been detected in canned food and human saliva. Bisphenol A stimulate cell proliferation and induce expression of estrogen -response genes in vitro. The purpose of the this study was to evaluate cell proliferation of bisphenol A in the presence of a rat liver 59 mix contaning cytochrome P450 enzymes and Cu (II). The fragmentation of intact DNA, a parameter of apoptotic cell death, was evaluated quantitatively by diphenylamine reaction method. Bisphenol A induced apoptotic cell death in a dose-dependent manner The effect of radical scavenger on the apoptotic cell death induced bisphenol A was investigated. The DNA fragmentation induced by bisphenol A was significantly inhibited by addition of radical scavenger to the culture medium. This indicated that elevated oxidative stress caused by imbalance between the production and removal of free radicals occurred in cells. Taken together, these results suggest that free radical reacts with Cu (II) leading oxidative stress.

• Molecules and Cells
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• v.39 no.2
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• pp.136-140
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• 2016

Eph receptors and their ligands, ephrins, mediate cell-to-cell contacts in a specific brain region and their bidirectional signaling is implicated in the regulation of apoptosis during early brain development. In this report, we used the alpha(${\alpha}$)-Cre transgenic line to induce ephrin-A5 over-expression in the distal region of the neural retina. Using this double transgenic embryo, we show that the over-expression of ephrin-A5 was responsible for inducing massive apoptosis in both the nasal and temporal retinas. In addition, the number of differentiated retinal neurons with the exception of the bipolar neuron was significantly reduced, whereas the laminar organization of the mature retina remained intact. Consistent with this finding, an analysis of the mature retina revealed that the size of the whole retina-particularly the nasal and temporal regions-is markedly reduced. These results strongly suggest that the level of ephrin-A5 expression plays a role in the regulation of the size of the retinal progenitor pool in the neural retina.

• The Korean Journal of Food And Nutrition
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• v.6 no.3
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• pp.219-230
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• 1993

This research aims to study the changes In gastrointestinal function attributed to aging In human. The thresholds for recognition and detection of flavors became elevated and salivary gland acinar cells decreased in the old age. But most esophageal function remained relatively Intact. Although gastric emptying time has been slowed with aging, the total intestinal transit time did not differ. Atropic gastritis due to H. pylori in old man decreased secretion of acid and Intrinsic factor and absorbability of calcium and iron. Pancreatic secretion is droned in older persons. Prevalence of gallstones rised with age. Liver size and portal blood flow decreased significantly with age. Mucosal surface area has been reported to be slightly diminished in the aging man. Glucose transporters decreased and Insulin tolerance Increased. Absorption of aromatic amino acid is diminished with age. Dietary protein In that aging human increased fecal nitrogen excretion. Vitamin A tolerance increased. Vitamin D receptor concentration decreased and resistance to 1,25-(OH)2D3 action increased. Permeability of aging small Intestine Increased. Zinc balance dirt not differ Copper absorption appeared not to be significantly affected by age. Neurotensin secretion decreased thus slowed colonic peristaltic movements and Intestinal mucosal growth.

• Environmental Analysis Health and Toxicology
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• v.18 no.3
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• pp.165-174
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• 2003

Cr (Ⅵ) - containing compounds are well-established carcinogens, although the mechanism for chromium - induced carcinogenesis is still not well understood. The reduction of Cr (Ⅵ) to its lower oxidation states, par ticularly Cr (V) and Cr (IV), is an important step for the production of chromium-mediated reactive oxygen species (ROS). The persistent oxidative stress during the reduction process may play a key role in the mechanism of Cr (Ⅵ) -induced carcinogenesis. This paper summarizes recent studies on (1) the reduction of Cr (Ⅵ) to Cr (III) occur by a multiplicity of mechanisms depending on the nature of reducing agents including ascorbate, diol-and thiol-containing molecules, certain flavoenzymes, cell organelles, intact cells, and whole animals; (2) free-radical production with emphasis on hydroxy radical generation via Fenton or Haber-Weiss type reactions; and (3) free radical - induced cellular damage, such at DNA strand breaks, hydroxylation of 2'-deoxyguanosine, and activation of nuclear transcription factor kB.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.32-32
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• 2001

Helicobacter pylori (Hp), an important etiologic agent in a variety of gastroduodenal diseases, produces a large amount of urease, which is believed to neutralize gastric acid by producing ammonia for the survival of the bacteria. Up to 30％ of the enzyme is associated with the surface of intact cells by lysis of neighboring bacteria. However, the role of the external enzyme has been a subject of controversy, because the enzyme is irreversibly inactivated below pH 5.(omitted)

• Korean Journal of Veterinary Research
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• v.62 no.4
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• pp.34.1-34.4
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• 2022

We describe four cases of feline progressive histiocytosis (FPH) including three females (one intact, two spayed) and one castrated male cat, with a mean age of 5.95 years at diagnosis. Masses were found under the skin of head, lip, neck, and vulva. Histologically, proliferative round cells had ovoid nuclei, foamy eosinophilic cytoplasm, distinct cytoplasmic processes, and numerous mitotic figures. Immunohistochemically, all cases were positive for Iba1 and MHC II (Dako). One case showed cytoplasmic positive staining for E-cadherin. To the best of our knowledge, this is the first documented report of FPH in Korea.

• Korean Journal of Animal Reproduction
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• v.14 no.1
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• pp.36-42
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• 1990

The effect of preincubation on in vitro maturation and fertility were investigated using preovulatory oocytes with and without cumulus cells obtained from superovulated ouot-bred ICR mice. Oocytes were recovered from fully grown folicle at 10 hr after hCG administration. A part of oocytes recovered were treated with the solution of 0.1% hyaluronidase to remove cumulus cells. Both intact and treated oocytes were then incubated for 0 to 6hr in mT6 medium containing 0.3% BSA. After incubation for various times, a part of oocytes were subjected to the investigation of nuclear maturation and the remaining oocytes were used fro the induction of in vitro fertilization by adding them into medium containing capacitated mice epididymal spermatozoa. Above all, the percentage of preovulatory oocytes at the stage of metaphase II after preincubation for 0, 2, 4 and 6hr was 15.8, 36.4, 47.5 and 66.7%, respectively, suggesting the in vitro maturation of oocytes during their incubation. On the other hand, fertilizatin rate of oocytes preincubated for 0, 2, 4 and 6hr with and without cumulus cells were 41.0, 58.7, 68.7 and 75.6%, and 50.0, 45.1, 37.8 and 39.2%, respectively. No significant differences in fertilization rate between preovulatory oocytes preincubated for 6hr with cumulus cells and naturally ovulated were observed. These results suggest that cumulus cells take very important role in maturtion of oocytes in vitro. The precentage of preovulatory oocytes developed to 2-cell stage in vitro fertilization following preincubation for 0 to 6hr with and without cumulus cells ranged from 48.5 to 82.4% and 36.9 to 56.1%, respectively. Also, the rates of oocytes developed to blastocyst in vitro fertilization after preincubation for 0 to 6hr with and without cumulus cells were 28.1, 39.3, 42.5 and 44.0% and 12.5, 32.6, 24.4 and 15.5%, respectively. From these results, it could be said that fertility of preovulatory oocytes with cumulus cells could be improved to the level of that of naturally ovulated oocytes by adquate preincubation in vitro. Cumulus cells may, therefore, affect in vitro maturation, fertilization and following development of oocytes by influencing zona hardening.

• Korean journal of applied entomology
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• v.36 no.4
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• pp.341-350
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• 1997

We have now constructed a novel recombinant baculovirus producing fusion protein with Autographa californica nuclear polyhedrosis virus (AcNPV) polyhedrin and Bacillus thuringiensis(Bt) cryIA(c) crystal protein. The fusion protein expressed by the recombinant baculovirus in insect cells was characterized. The N-terminal of cryIA(c) gene of Bt subsp. kurstaki HD-73 was introduced under the control of polyhedrin gene promoter of AcNPV, by fusion in the front of intact polyhedrin gene or by insertion into the HindIII site in polyhedrin gene. The recombinant baculoviruses were named as BtrusI or BtrusII, respectively. Although single transcript from the fusion protein gene was apparently observed. BtrusI was produced the two proteins, 92 kDa fusion protein and only polyhedrin. In addition, fusion protein produced by BtrusI did not form polyhedra. Interestingly, however, the cells infected with BtrusII did not show a 33 kDa polyhedrin band as a cells infected with BtrusI. Cells infected with BtrusII were only produced fusion protein, but the polyhedra formed by fusion protein was not observed. To determine the insecticidal toxicity of fusion protein, therefore, Sf9 cells infected with BtrusI were inoculated to Bombyx mori larvae. Sf9 cells infected with BtrusI that expressed the fusion protein caused larval mortality although the insecticidal toxicity was low. In conclusion, our results clearly demonstrated that the fusion protein with polyhedrin and Bt cryIA(c) crystal protein have a insecticida toxicity.

• Interdisciplinary Bio Central
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• v.1 no.2
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• pp.7.1-7.7
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• 2009

"To be, or not to be?" This question is not only Hamlet's agony but also the dilemma of mitochondria in a cancer cell. Cancer cells have a high glycolysis rate even in the presence of oxygen. This feature of cancer cells is known as the Warburg effect, named for the first scientist to observe it, Otto Warburg, who assumed that because of mitochondrial malfunction, cancer cells had to depend on anaerobic glycolysis to generate ATP. It was demonstrated, however, that cancer cells with intact mitochondria also showed evidence of the Warburg effect. Thus, an alternative explanation was proposed: the Warburg effect helps cancer cells harness additional ATP to meet the high energy demand required for their extraordinary growth while providing a basic building block of metabolites for their proliferation. A third view suggests that the Warburg effect is a defense mechanism, protecting cancer cells from the higher than usual oxidative environment in which they survive. Interestingly, the latter view does not conflict with the high-energy production view, as increased glucose metabolism enables cancer cells to produce larger amounts of both antioxidants to fight oxidative stress and ATP and metabolites for growth. The combination of these two different hypotheses may explain the Warburg effect, but critical questions at the mechanistic level remain to be explored. Cancer shows complex and multi-faceted behaviors. Previously, there has been no overall plan or systematic approach to integrate and interpret the complex signaling in cancer cells. A new paradigm of collaboration and a well-designed systemic approach will supply answers to fill the gaps in current cancer knowledge and will accelerate the discovery of the connections behind the Warburg mystery. An integrated understanding of cancer complexity and tumorigenesis is necessary to expand the frontiers of cancer cell biology.