• Advances in pediatric surgery
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• v.17 no.2
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• pp.179-187
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• 2011

Experimental tracheal ligation (TL) has been shown to reverse the pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and to normalize gas exchange. The purpose of this study was to determine whether the TL would correct the surfactant deficiency present in the fetal rabbit model of CDH by using lamellar body count. Lamellar bodies are synthesized and secreted by the type II pneumocytes of fetal lung. The phospholipids present in these bodies constitute the major component of pulmonary surfactant. Twenty-one pregnant New Zealand rabbits underwent hysterotomy and fetal surgery on gestational day 24. Two fetuses of each pregnant rabbit were operated. In the fetus of one end of bicornuate uterus, left DH was created by excision of fetal diaphragm through open thoracotomy (DH Group). In the fetus of the other end of bicornuate uterus, left DH and TL were created (TL Group). The fetuses were delivered by Cesarean section on gestational day 31. Fourteen in control group, 12 in the DH group and 13 in TL group were born alive. En bloc excision of lungs, bronchi and trachea was done in all newborn rabbits. A five Fr catheter was inserted through trachea and repeated irrigations with 10 cc normal saline were done. The irrigated fluid was centrifuged at $280{\times}g$ for 5 minutes and the lamellar bodies were counted with the upper level fluid in platelet channel of electronic cell counter. The average lamellar body counts were $37.1{\pm}14.2{\times}10^3/{\mu}L$ in control group, $11.5{\pm}4.4 {\times}10^3/{\mu}L$ in DH group, and $6.5{\pm}0.9{\times}10^3/{\mu}L$ in TL group. Lamellar body count in DH group was lower than in control group and did not increase after TL. This study shows TL has no therapeutic effect on decreased surfactant level of CDH and the pregnant rabbit is appropriate for the animal model of CDH.

• Applied Microscopy
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• v.28 no.4
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• pp.603-613
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• 1998

The present study was designed in order to observe relationship between the endoplasmic reticulum and the Golgi complex during spermiogenesis of the long-fingered bat (Miniopterus schreibersi fuliginosus). The testes were obtained from adult bats and treated with the prolonged osmification or fixed with ferrocyanide reduced osmiun. In the Golgi phase, The Golgi complex shows an oval shape, and was composed of a cortex and a medullar enclosing acrosome. The Golgi vacuoles with electron-dense granules of crescent shape were fused with each other. The smooth endoplasrnic reticulum was scattered in all the area of the cytoplasm. In the cap phase, The Golgi complex was crescent in shape, and faced to a nucleus. Large and small vesicles were fused with each other, and then fused with a acrosomal vacuole. The rough endoplasmic reticulum was close to the large Golgi vacuole. In the acrosome phase, The Golgi complex was moved to behind of the acrosome face. Small vesicles were fused with an acrosome, and cisternae of the trans-face of Golgi complex was connected with an acrosome in the early acrosome phase. The smooth endoplasmic reticulum was distributed in the cytoplasm. The annulate lamellar was originated from a radial body-annulate lammellae complex. In the maturation phase, The Golgi complex with dilated cistrern appeared in the cytoplasm, and also, annulate lamellar was observed in the cytoplasm. The connection of the annulate lamellar with the cistern of radial body suggests that an annulate lamellar seems to be closely related to radial body. The smooth endoplasmic reticulum was scattered in the cytoplasm in the early Golgi phase, but annulate lamellar-radial body complex which might be a residual and disappearing form of the smooth endoplasmic reticulum appeared in the acrosome phase. The Golgi complex steadily remained in the late maturation phase when the endoplasmic reticulum began to disappear from the cytoplasm: the Golgi complex was still occurred after acrosome formation. The observations obtained in the present study, which was characterized by the presence of the Golgi complex in the late maturation phase, suggests that the Golgi complex may play an important role also even after the acrosome formation.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.191-191
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• 2006

The structures of the mesophases and their subunits of PS-b-P4VP in a toluene solution were studied by using SAXS, TEM and GIFT methods. The hierarchical structures of PS-b-P4VP, such as the individual micelle, the face-centered cubic (fcc) and body-centered cubic (bcc) structures and the lamellar structure, were identified for the first time. The diameter of the micelle core was ${\sim}80\;%$ of the most extended chain length of the core chain, suggesting that the core chains were quite stretched. The stretched chain in the core caused the core of the micelle to be not homogenous with a higher density at the center than at the outer part. As the concentration level increases, the fcc and both fcc and bcc appear for the packing of the micelles of PS(3.3k)-b-P4VP(4.7K) and PS(12K)-b-P4VP(11.8K), respectively. The lamellar structure was also identified, with a further increase in the concentration for PS(3.3k)-b-P4VP(4.7K). These hierarchical structures were also identified via TEM images.

• Polymer(Korea)
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• v.27 no.6
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• pp.509-520
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• 2003

The study was made to compare the crystallization behavior of polypropylene (PP) with different stereo-regularity. The unit cell parameters, lamellar structure of PP, and the growth of thieir spherulites were strongly dependent upon the crystallization condition. It was shown that metastable structure appeared with increasing cooling rate. The structural change of isotactic PP (iPP) was larger than that of syndiotactic PP (sPP). The crystal structure of sPP showed body centered cell III when it is cooled down with 1 $^{\circ}C$/min. When sPP was grown to primitive cell II structure, both unit cell and lamellar structure were less affected by a cooling rate. The overall crystallization rate of ipp was faster than that of sPP.

• Journal of Technologic Dentistry
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• v.29 no.1
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• pp.133-138
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• 2007

In this study, the castability and of commercially pure titanium(c.p.Ti) grade according to the casting condition which are the vacuum condition in casting machine and mold temperature of investment, was investigated. Argon-arc melt/centrifugal casting machine was used for casting the specimens. The microstructure and mechanical properties were evaluated by using optical microscope. The results were as follows; 1. It could make a sure that there's relatively not much defect of casting body of c.p.Ti according to the deference of air pressure. 2. It could make sure that it formed porosity on the surface inside of the casting body of c.p.Ti according to deferent temperature. and on excellent castability was below $200^{\circ}C$ 3. As the mold temperature of investment was increased, the lamellar structure of phase and coarse grains were shown, especially under 42MPa.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.669-676
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• 2013

Lung fluke, Paragonimus heterotremus, is a flatworm causing pulmonary paragonimiasis in cats, dogs, and humans in Southeast Asia. We examined the ultrastructure of the testis of adult P. heterotremus with special attention to spermatogenesis and spermiogenesis using scanning and transmission electron microscopy. The full sequence of spermatogenesis and spermiogenesis, from the capsular basal lamina to the luminal surface, was demonstrated. The sequence comprises spermatogonia, spermatocytes with obvious nuclear synaptonemal complexes, spermatids, and eventual spermatozoa. Moreover, full steps of spermatid differentiation were shown which consisted of 1) early stage, 2) differentiation stage representing the flagella, intercentriolar body, basal body, striated rootlets, and electron dense nucleus of thread-like lamellar configuration, and 3) growing spermatid flagella. Detailed ultrastructure of 2 different types of spermatozoa was also shown in this study.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.1
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• pp.171-178
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• 1994

This paper reports histologic and histomorphometric results concerning bone healing around vent area of 16 titanium plasma sprayed IMZ implants in rabbit femurs. Bone contact around the implants 8 weeks after placement showed a great deal of variability from 14.32% to 65.94% and mean total bone contact was 33.96%. The mean percent amount of bone contact was 43.68% in inner surface of vent and 27.79% in outer surface. Histologic examination of horizontal sections of vent area showed direct contact with living lamellar bone and some woven bone. The implants surface area not in contact with bone was in contact with collagenous connective tissue. But there was no sign of foreign-body reaction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.5
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• pp.315-317
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• 2022

Osseous metaplasia is defined as the formation of lamellar bone inside soft tissue structures where bone normally does not exist. It results from the transformation of non-osseous connective tissue into mature bone. This condition is rare in the oral and maxillofacial region. We report a case of osseous metaplasia of the maxilla, a rare benign tumor in an uncommon region. A 60-year-old male patient visited our clinic complaining of foreign body sensation and asymptomatic swelling on the right palatal side. However, he did not experience pain and reported no local trauma that he could remember. Intra-oral examination revealed an exophytic lesion on the right palatal portion. On computed tomography, there was a round hard-tissue mass approximately 2 cm in diameter on the right palate area. The mass was biopsied and diagnosed as an osseous metaplasia. We review the clinical, radiographic, and histologic features and common causes of osseous metaplasia and report a rare case of osseous metaplasia of the palate.

• Korean Journal of Veterinary Research
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• v.37 no.1
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• pp.59-69
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• 1997

The histological and histochemical study of the body of axis and 1st intervertebral disc in the Korean native cattle fetus was attempted to early developmental process. The experimental animals used in this study were collected from fetus of the Korean native cattle ranging from 50mm to 180mm in Crown-Rump length(CR-length). The results were summerized as follows: 1. The ossification centers appeared centrum 1 and centrum 2 of the axis in 110mm CR-length fetus of the Korean native cattle. The centrum 2 was formed little earlier than the centrum 1. 2. The histochemical reactions for collagenous fibers in the axis revealed negative in 50mm CR-length, mild positive in 90mm CR-length, and strong positive in 110mm CR-length, respectively. 3. Dense collagenous fibers were observed in the notochord through the centrum 2, and intervertebral disc developed into cuneiform dorsoventrally, It's contour looks like an annual ring. These fiber bundle arranged lamellar formation. 4. The intervertabral disc of 50mm CR-length fetus was composed mainly mesenchymal cells, and these cell showed aggregation in the central portion. The intervertebral disc of 110mm CR-length fetus was consisted of pricipally fibroblast, and notochordal sheath formed with two layers in the center.

• Applied Microscopy
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• v.29 no.3
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• pp.383-403
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• 1999

This study was performed to investigate the immunohistochemical and ultrastructural characterization of the choline acetyltransferase (ChAT)-immunoreactive nerve cells in the diagonal band of Broca of the rat basal forebrains, utilizing techniques of immunohistochemical and immunocytochemical microscopy. The ChAT-immunoreactivities were shown within neuronal cell bodies and processes by the light micoscope. According to cell shape and ratio of long axis vs short axis of cell body, the ChAT-immunoreaclive nerve cells in both vertical and horizontal limbs of the diagonal band of Broca were classified into 6 types. at the light microscopic level; round, oval, elongated, fusiform, triangular and polygonal types. As a result of the electron microscopic observation, the ChAT-immunoreactivated products appeared on the outer nuclear envelope, membranes of rough endoplasmic reticula (rER), free ribosomes and polysomes. Each cell type was subdivided into subtype I and II according to the several criteria such as volume of cell body, nuclear size relative to the cytoplasm, kinds and distribution of cell organelles and numbers and sorts of synapses. The subtype I of immnunoreactive nerve cells had large cell body and a small nucleus showing shallow indentations of nuclear evelope. In this subtype I with abundant cytoplasm, rER were well differentiated. Their long cisternae were parallelly ditributed and lamellated. One or two lamellar bodies and nematosomes were observed. The subtype II cell had small cell body and a large nucleus with deep indentations of nuclear envelope. In this subtype II with small cytoplasm, the rER were irregularly distributed and the lamellar body and nematosome were not found. A few axosomatic synapses in the subtype I and II were shown to be symmetric or asymmetric. The ratios of the symmetric synapse to the asymmetric one were investigated to be 1 : 2 and 1 : 4 in the subtype I and II, respectively. The axodendritic ones were almost asymmetric. But, the fusiform and triangular immunoreactive nerve cells were shown only to be subtype I. According to observations in this study, it is considered that the ultrastructural characterization in the 2 subtypes of each cell type may reflect the differences of the metabolic activities and projecting distances to the target cells.