• Korean Journal of Poultry Science
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• v.24 no.3
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• pp.107-116
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• 1997

In order to achieve optimal reproductive performance, reliable morphological and physiological basic data on the reproductive organs are desirable. Adult male Korean ring-necked pheasant in inactive(mid of January) and active state (end of April) were used in this study. In addition, five active state pheasants were received a single dose of 60Co-ray 500 rads each to damage the testes. The objective of this study was to investigate the distribution pattern of protein gene product (PGP) 9.5 and ${\alpha}$-tubulin in the pheasant testes of the active, inactive and ${\gamma}$-ray irradiated active states. The results obtained were summarized as follows 1. The seminiferous tubules collected in inactive states( mid of Jan) showed narrow lumen, and the spermatogonia and the Sertoli cell were well preserved. The PGP 9.5 immunoreactivity of these tubules showed a positive reaction in paranucleus area of the spermatogonia, and a positive reaction in a small number of the Leydig cells in the interstitium of the seminiferous tubules. 2. The seminiferous tubules were dilated in active state(end of April) as compared with the inactive state. The PGP 9.5 reactivity in these tubules showed a positive reaction in many Leydig cells in the interstitium of the seminiferous tubules, and the testes of ${\gamma}$-ray irradiated group showed partially weak reaction in the interstitium of the seminiferous tubules. 3. The ${\alpha}$-tubulin reactivity in the seminiferous tubules of the inactive testes was strongly positive in the cytoplasmic process of the Sertoli cell from the basal stem region to the apical ex-tension. From the broad part of the stem region to the luminal space, the active testes showed a strong positive reaction. The ${\gamma}$-ray irradiated groups showed diminished reaction in the basal region.

• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.392-401
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• 2003

The purpose of this study was to evaluate the penetration pattern of dentin adhesives according to the orientation of dentinal tubules with confocal laser scanning microscopy. Specimens having perpendicular. parallel and oblique surface to dentinal tubules were fabricated. The primer of dentin adhesives (ALL $BOND^{\circledR}{\;}2,{\;}CLEARFIL^{TM}$ SE BOND and PQ1) was mixed with fluorescent material. rhodamine B isothio-cyanate (Aldrich Cherm. CO., Milw., USA), It was applied to the specimens according to the instructions of manufactures. The specimens were covered with composite resin (Estelite, shade A2) and then cut to a thickness of 500$\mu\textrm{m}$ with low speed saw (Isomet^{TM}, Buehler. USA). The adhesive pattern of dentin adhesives were observed by fluorescence image using confocal laser scanning microscopy. The results were as follows. 1. For the groups with tubules perpendicular to bonded surface. funnel shape of resin tag was observed in all specimen. However. resin tags were more prominent in phosphoric acid etching system (ALL $BOND^{\circledR}$ 2 and PQ1) than self etching system ($CLEARFIL^{TM}$ SE BOND). 2. For the groups with tubules parallel to bonded surface. rhodamine-labeled primer penetrated into peritubular dentin parallel to the orientation of dentinal tubules. But rhodamine-labeled primer of PQ1 diffused more radially into surrounding intertubular dentin than other dentin adhesive systems. 3. For the groups with tubules oblique to bonded surface. resin tags appeared irregular and discontinuous. But they penetrated deeper into dentinal tubules than other groups.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.529-543
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• 2020

In contrast to ventricular myocytes, the structural and functional importance of atrial transverse tubules (T-tubules) is not fully understood. Therefore, we investigated the ultrastructure of T-tubules of living rat atrial myocytes in comparison with ventricular myocytes. Nanoscale cell surface imaging by scanning ion conductance microscopy (SICM) was accompanied by confocal imaging of intracellular T-tubule network, and the effect of removal of T-tubules on atrial excitation-contraction coupling (EC-coupling) was observed. By SICM imaging, we classified atrial cell surface into 4 subtypes. About 38% of atrial myocytes had smooth cell surface with no clear T-tubule openings and intracellular T-tubules (smooth-type). In 33% of cells, we found a novel membrane nanostructure running in the direction of cell length and named it 'longitudinal fissures' (LFs-type). Interestingly, T-tubule openings were often found inside the LFs. About 17% of atrial cells resembled ventricular myocytes, but they had smaller T-tubule openings and a lower Z-groove ratio than the ventricle (ventricular-type). The remaining 12% of cells showed a mixed structure of each subtype (mixed-type). The LFs-, ventricular-, and mixed-type had an appreciable amount of reticular form of intracellular T-tubules. Formamide-induced detubulation effectively removed atrial T-tubules, which was confirmed by both confocal images and decreased cell capacitance. However, the LFs remained intact after detubulation. Detubulation reduced action potential duration and L-type Ca²⁺ channel (LTCC) density, and prolonged relaxation time of the myocytes. Taken together, we observed heterogeneity of rat atrial T-tubules and membranous ultrastructure, and the alteration of atrial EC-coupling by disruption of T-tubules.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.258-264
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• 2014

Objectives: This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods: Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Results: Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Conclusions: Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

• Restorative Dentistry and Endodontics
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• v.21 no.1
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• pp.267-279
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• 1996

Microorganisms are implicated the endodontic treatment failures. Persistent endodontic infection may be the result of retention of microorganisms in the dentin of the root canal walls. Dentinal tubules of the root canal walls have been shown to harbor microorganisms. The purpose of this study was to investigate the invasion of microorganism into the root dentin and dentinal tubules. The effects of irrigation solutions and smear layer on bacterial colonization of root canal were evaluated using a scanning electron microscopy. Canals of extracted human teeth with single and straight canals were stepback prepared using normal saline. Tooth samples were divided into four groups according to the irrigation solutions -5 % sodium hypochlorite and normal saline-and smear layer treatment. The smear layer was removed by 5% NaOCl and 20% EDTA for 10 min respectively. After sterilization, they were incubated with each strains of Streptococcus sanguis, Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Sodium hypochlorite solution reduced the adhesion of microorganisms effectively compared to normal saline. The smear layer inhibited colonization of E. faecalis, S. aureus and E. coli in the root canals due to their blocking of dentianl tubules. But S. sanguis invaded dentinal tubules in the root canals without smear layer. It was suggested that bacterial attachment might be different according to the strains. Sodium hypochlorite inhibited bacterial attachment in the dentinal tubules dramatically. The absence or presence of smear layer affected bacterial invasion of the dentinal tubules.

• Journal of Periodontal and Implant Science
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• v.43 no.6
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• pp.269-275
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• 2013

Purpose: In this study, the effect of calcium sodium phosphosilicate (NovaMin) desensitizing agent, which is a powder-based system, and hydroxyethyl methacrylate and glutaraldehyde (Gluma desensitizer), which is liquid-based system, on dentinal tubule occlusion was analyzed by scanning electron microscope. The effects of the above two along with one control group were compared to determine the more effective method of sealing the dentinal tubules after initial application. Methods: Twenty specimens were allocated to each of 3 groups: Control, Gluma desensitizer, and NovaMin. Two additional samples were also prepared and treated with Gluma and NovaMin; these samples were longitudinally fractured. The specimens were prepared from extracted sound human premolars and were stored in 10% formalin at room temperature. The teeth were cleaned of gross debris and then sectioned to provide one to two dentin specimens. The dentin specimens were etched with 6% citric acid for 2 minutes and rinsed in distilled water. Control discs were dried, and the test discs were treated with the desensitizing agents as per the manufacturer's instructions. The discs as well as longitudinal sections were later analyzed under the scanning electron microscope. The proportions of completely occluded, partially occluded, and open tubules within each group were calculated. The ratios of completely and partially occluded tubules to the total tubules for all the groups was determined, and the data was statistically analyzed using nonparametric tests and statistical significance was calculated. Results: NovaMin showed more completely occluded tubules ($0.545{\pm}0.051$) while Gluma desensitizer showed more partially occluded tubules ($0.532{\pm}0.075$). The differences among all the groups were statistically significant ($P{\leq}0.05$). Conclusion: Both materials were effective in occluding dentinal tubules but NovaMin appeared more promising in occluding tubules completely after initial application.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.508-526
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• 1995

This experiment was performed to study mechanisms of desensitization by chemical desensitizing agents in hypersensitive dentin and compare effects of these agents by measuring the activity of intradental nerves and observing their occluding aspects on dentinal tubules with SEM over time after application of chemical desensitizing agents to the exposed dentinal surfaces. Canines of adult cats weighing 2-3 kg were cross-sectioned at 1.5 mm from incisal apex, and the smear layer of the exposed dentinal susface was removed by 32 % $H_3PO_4$ for 15 sec. Chemical desensitizing agents such as 10% $SrCl_2$, 5% $KNO_3$ and 30% $K_2C_2O_4$, were applied to the exposed dentin surfaces for 2 minutes. Intradental nerve activity was measured immediately after application of the agents, at 15 minutes and at 30 minutes by stimulating with 4M NaCl. To compare occluding ability of desensitizing agents on dentinal tubules in vivo and in vitro, the structures of the exposed dentinal surfaces of nonvital and vital teeth were morphologically observed by SEM. The results obtained were as follows : 1. Intradental nerve activity was decreased immediately after the application of 10 % $SrCl_2$, 5% $KNO_3$ and 30% $K_2C_2O_4$. (p<0.01), among which 30% $K_2C_2O_4$. showed the highest desensitizing effect(p<0.01). 2. The immediately decreased intradental nerve activity after application of 10 % $SrCl_2$ and 5% $KNO_3$ was increased over time. 10% $SrCl_2$ and 5% $KNO_3$ showed no desensitizing effect respectively at 30 minutes and at 15 minutes after application. 3. The immediately decreased intradental nerve activity after application of 30 % $K_2C_2O_4$ was persistently continued during the period of observation (p<0.01). 4. Precipitates of $SrCl_2$ and $KNO_3$ were not noted on the exposed dentinal surfaces and within dentinal tubules by SEM examination. On the other hand, 30 % $K_2C_2O_4$ produced precipitates on the exposed dentinal surfaces and openings of dentinal tubules without any formed preciptates within dentinal tubules. 5. Ten percent $SrCl_2$, 5 % $KNO_3$ and 30 % $K_2C_2O_4$ showed no differences in their occluding aspects on dentinal tubules either in vivo or in vitro studies and either immediately following application or at 30 minutes. These results suggest that the desensitizing effect of $SrCl_2$ and $KNO_3$ is resulted from their reducing effect on the intradental nerve activity rather than from their precipitates' occluding the dentinal tubules. However, desensitizing effect of 30 % $K_2C_2O_4$, is probably resulted from its precipitates' occluding the openings of the dentinal tubules as well as from it's reducing effect on the intradental nerve actibity.

• The Korean Journal of Cytopathology
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• v.8 no.2
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• pp.190-193
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• 1997

The sex cord tumor with annular tubules(SCTAT) is a rare ovarian neoplasm, which charateristically shows simple and complex annular tubules with central acidophilic hyaline bodies. This tumor has been considered as a tumor of low-grade malignancy with late recurrence. We presented a brief case report of metastatic SCTAT of ovary in pleural fluid from ovary with cytopathologic and clinical features. The cytologic features of differential diagnosis are discussed.

• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.483-496
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• 1993

Dentin hypersensitivity medicaments such as Gluma, Scotchbond 2, All-Bond 2, which are resin adhesives, were used to compare the sealing effects of dentinal tubule under mechanical stress. Topical application of above medicaments on the dentin surfaces of extracted teeth followed by artificial tooth brushing for 6 weeks was performed for the comparison. The following conclusions on the degree of dentinal tubule exposure versus time by were reached by using polyvinyl siloxane impression material for taking the impression, epoxy resin for the duplication and SEM for observing the surface. 1. SEM was used to compare the accuracy of the duplicated surface, but no differences were found when teeth samples and the duplicated surfaces were observed. 2. After comparing the degree of dentinal tubules exposure with varnish applied contrast group, resin adhesive materials showed much less exposure as time went by. 3. The results indicated that AU-Bond 2 adhesive, under mechanical stress, showed lesser exposure of dentinal tubules comparing with Gluma and Scotchbond 2 adhesives After the results were put together, it was demonstrated that resin replica method is an useful way to evaluate the treatment effects of the dentinal tubule hypersensitivity medicaments. Also, it was noticed that under mechanical stress, All-Bond 2, classified as fourth generation, illustrated the best dentinal tubules sealing effects.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.364-372
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• 2016

Sand tubules, made up of sand grains cemented by microbe-induced calcium carbonate precipitation, have been found in China's Ningxia Province. Sand tubules grow like a tree's roots about 40-60 cm below the surface. The properties of sand tubules and their bacterial community were examined. X-Ray diffraction analysis revealed that the sand tubules were associated with crystalline calcite. Scanning electron microscopy showed that the crystalline solid had a lamellar structure and lacked the presence of cells, suggesting that no bacteria acted as nucleation sites, nor that the crystalline solid was formed by the aggregation of bacteria. Denaturing gradient gel electrophoresis analysis showed 11 of the 12 detectable bands were uncultured bacteria by BLAST analysis in the GenBank database, and the rest were closely related to Paenibacillus sp. (100% identity). By cultivation techniques, the only strain isolated from the sand tubule was suggested to be related to Paenibacillus sp.; no archaea were found. Furthermore, Paenibacillus sp. was demonstrated to induce calcium carbonate precipitation in vitro.