• Journal of Mechanical Science and Technology
• /
• v.15 no.7
• /
• pp.965-973
• /
• 2001

It is well established that arteries are subjected to residual stress. Due to the effect of residual stress, the arteries open to a horse-shoe shape when a longitudinal cut is made on an excised arterial segment. Previously, the residual stress has been quantified by the opening angle of the horse-shoe shape. We have employed a finite element analysis of the open arterial segment to restore the same to the original cylindrical shape and computed the circumferential strain as well as the stress distribution in the wall. In this study, the stress distribution in the femoral arteries of miniswine was computed with and without the residual stress for a range of transmural pressures. Our analysis showed that the residual stress has the effect of redistribution of the circumferential stresses between the intima and the adventitia under physiological loading. The redistribution of the stress with the inclusion of residual stress may be important in the studies on effect of wall stresses on the endothelial and vascular smooth muscle cells.

• Journal of Veterinary Clinics
• /
• v.23 no.2
• /
• pp.194-196
• /
• 2006

A leiomyosarcoma that occurred in the right kidney with hepatic metastasis of a 15-year-old intact female Asian water buffalo (Bubalus arnee) in a zoo, Republic of Korea. The animal showed no clinical signs. Grossly, a firm and white mass (6.0 x- 5.0- x 4.0 cm) was observed in the renal capsule and multiple firm white nodules, measuring 1.0-2.5 cm, were present on the surface of the liver. Microscopically, tumor cells were spindle-shaped, the cell density was high, and complex fasciculated tumor cells showing longitudinal and transverse cross-sections were observed. Tumor cell nuclei was ordinarily cigar shaped and had rounded blunt ends. Immunohistochemically, tumor cells reacted intensely with anti-smooth muscle actin antibody. This is the first case report of a renal leiomyosarcoma with hepatic metastasis in a Asian water buffalo.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.3 no.1
• /
• pp.108-127
• /
• 1996

The purpose of this research was to determine whether or not a education program of low back pain would have benificial effect on nurses. Nonequivalent control group pre-post test research was designed. Subjects for this study were 50 selected from nurses who work at a general hospital in Taegu. Of them, twenty seven were assigned to experimental group, twenty-three to control group. The data were collected during the period from June 27 to August 31, 1994. The instruments used in this study were Visual Analog Scale for low back pain, Sit-and-reach test for trunk flexibility, and 1 min sit up test for abdominal muscle endurance. Data related to general chracteristics and factors of low back pain were collected with questionnaire developed by this reseacher. The data were analyzed by $X^2-test$, t-test and paired t-test, using the SAS package program. The results of this study are summerized as follows : 1. The numbers of the experimental group with low back pain were not a statistically significant difference from pre to posttesting($X^2=0.77$, p=.379), and the numbers of the control group with low back pain were also not a statistically significant difference from pre to posttesting($X^2=0.09$, p=.767). 2. The severity of low back pain of the experimental group was not a statistically significant difference from pre to posttesting(t=-0.55, p=.5857), and the severity of low back pain of the control group was also not a statistically significant difference from pre to posttesting(t=-0.70, p=.3101). 3. The trunk flexibility of the experimental group was not a statistically significant difference from pre to posttesting(t= 1.08, p=.2835), and the control group's trunk flexibility was also not a statistically significant difference from pre to posttesting(t=0.85, p=.4026). 4. The abdominal muscle endurance of the experimental group was a statistically significant difference from pre to posttesting(t=-2.42, p=.0190), but the control group's abdominal muscle endurance was not a statistically significant difference from pre to posttesting(t=-0.06, p=.9556) This study suggest that replication of study with more sample and more rigid treatment should be needed. And furthermore, the longitudinal research is needed to determine the effectiveness of education program.

• Parasites, Hosts and Diseases
• /
• v.33 no.3
• /
• pp.165-172
• /
• 1995

A transmission electron microscopic study was performed on the ultrastructure of the tegumental layer of GymophoLloines seoi (Digenea: Gymnophallidae) metacercarlae and adults. The metacercariae were obtained from naturally infected oysters, Crcssosoea gigas, and the adults from experimentally infected C3H mice. The tegumental layer generally revealed a small number of foldings, numerous small vacuoles, sines, and muscle bundles. Beneath the muscle layer, nuclei of the tegumental cells were located. There was little difference in the structure of the tegument between the metacercariae and adults. The oral sucker, having well-developed muscle layers, showed a similar structure to the ventral sucker except numerous foldlngs in the ventral sucker. The ventral pit was surrounded by a thin spcpiu layer, where a number of microtubules and mitochondria were seen. Around the ventral pit located well-developed circular and longitudinal muscles. The results showed that the ultrastructure of the tegumental layer of G. seoi metacercariae and adults revealed little difference from other trematodes in general. The ventral pit, a peculiar structure of this trematode, seems to function as a sphincter or an accessory adhesive organ.

• The Korean Journal of Pharmacology
• /
• v.25 no.1
• /
• pp.53-58
• /
• 1989

For several years, we investigated the pharmacological action of several substances isolated from Buxus microphylla var koreana Nakai, which had been used as folk remedies of malaria and venereal disease. Cyclobuxine $D(C_{25}H_{42}ON_2)$, a steroidal alkaloid, exerted an antiinflammatory action, hypotensive and bradycardic effects in rats. In the present study, we isolated alkaloid from the acetone-insoluble fraction of the strong bases of this plants. This alkaloid $(C_{25}H_{38}ON_2)$ was identified as a steroidal alkaloid contained a cyclopropane ring by physical and chemical methods. It is a derivative of cyclobuxine D and named cyclobuxine E. We examined the effect of cyclobuxine E on the contractile response induced by acetylcholine and two distinct types of potassium-activated calcium channels in an intestinal smooth muscle of the rat. Cyclobuxine E inhibited significantly the Ach-induced contraction. The isolated longitudinal muscle from the rat duodenum was immersed calcium-depleted potassium depolarizing solution. Ten minutes after, 1.8 mM $CaCl_2$ was added to muscle bath and elicited a biphasic increase in muscle tension. Cyclobuxine E produced an appreciable inhibition of both components of the mechanical response. In addition, Cyclobuxine E introduced at a point when the tonic response had reached its maximum level, caused the muscle to exhibit a rapid loss of tension. Based on these experimental results, we proposed the possibility that the inhibitory action of cyclobuxine E on the isolated rat duodenum may be due to inhibiting the transmembrane fluxes of calcium ion in potassium-activated calcium channels.

• Journal of Aquaculture
• /
• v.17 no.3
• /
• pp.215-220
• /
• 2004

Using light microscopy, the digestive tract of the parrot fish, Oplegnathus fasciatus was studied histologically. The tract consists of esophagus, stomach, intestine and fifty or sixty pyloric caecae. Each pyloric caecum is a blind sac of banana shape, and is originated from pyloric end of the stomach. The relative length of gut (RLG), that is length of digestive tract to standard length, is 1.78 (n=30). Esophagus has an undeveloped submucosa and a well developed muscularis mucosae. Its mucosa displays primary and secondary folds lined with a cuboidal or columnar epithelium and numerous acidic mucous secretory cells. The stomach has muscularis, which consists of longitudinal and circular muscular layers; its submucosa and muscularis mucosae are well developed. Only primary folds are present in the stomach. Microvilli are present in the epithelial layer. The stomach has a well-developed gastric gland and relatively more secretory granules. Mucosal epithelium of the pyloric caeca is composed of neutral mucous secretory cells and columnar epithelium with developed microvilli in the apical portion. Using the morphological and histological features, the intestine may be divided into anterior, mid and posterior parts. It has an advanced striated border and abundant acidic mucous secretory cells and some neutral mucous secretory cells. The mid intestine has more abundant acidic mucous secretory cells than the anterior and posterior parts. A thick longitudinal muscle is formed in the intestine and its thickness is progressively increased towards the posterior end.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.8
• /
• pp.1134-1142
• /
• 2008

Cationic amino acid transporter $b^{0,+}AT$ (HGMW-approved gene symbol SLC7A9, solute carrier family 7, member 9) plays a crucial role in amino acid nutrition. In the present study, we describe the cloning and sequencing of porcine $b^{0,+}AT$. Based on the sequence of porcine $b^{0,+}AT$ deposited in the NCBI (National Center for Biotechnological Information), we identified a putative porcine homologue. Using rapid amplification of cDNA ends (RACE), the full-length cDNA encoding porcine $b^{0,+}AT$ was isolated. The porcine $b^{0,+}AT$ cDNA was 1,680 bp long, encoding a 487 amino acid trans-membrane protein. The predicted amino acid sequence was found to have 88.9% and 87.1% identity with human and mouse $b^{0,+}AT$, respectively. Real-time RT-PCR indicated porcine $b^{0,+}AT$ transcripts expressed in heart, kidney, muscle and small intestine. The small intestine had the highest $b^{0,+}AT$ mRNA abundance while the muscle had the lowest (p<0.05). Along the longitudinal axis, the ileum had the highest $b^{0,+}AT$ mRNA abundance while the colon had the lowest (p<0.05). The $b^{0,+}AT$ mRNA level was highest on day 7 and 90 in the duodenum (p<0.05). It increased from day 1 to day 26 in the jejunum (p>0.05) and had the highest abundance on day 60 (p<0.05). There was, however, no difference between day 1, 7, 26, 30, 90 and 150 (p>0.05). The strongest $b^{0,+}AT$ expression appeared on day 7 in the ileum before weaning, and then decreased till day 30 but rose gradually again from day 60 to 150 (p<0.05).

• Korean Journal of Veterinary Research
• /
• v.37 no.4
• /
• pp.693-706
• /
• 1997

The present study was designed to investigate the morphological developments of the stomach in the prenatal and postnatal rats. The gastric fundus of 16- to 22-day-old fetuses, neonates, 7-day-old, 14-day-old, 21-day-old, and adult rats were observed by light and scanning electron microscopy. Light microscopic studies. 1. In the 16-day-old fetuses, the walls of the gastric fundus were differentiated into epithelium, lamina propria, muscle layer, and serosa. The lamina propria was composed of mesenchymal connective tissue cells with sparse nucleus and their fibers. 2. In the 17-day-old fetuses, the muscular layer were differentiated into the circular and longitudinal muscle layers. 3. The epithelium on the fundus of stomach was stratified columnar cells at 16-, 17- and 18-day-old fetuses, but partly converted into simple columnar epithelium at 19-day-old fetuses. 4. The mucous cells were positive by PAS reaction at the 19-day-old fetuses and then these developed rapidly within 1 or 2 days before birth. 5. In the 20-day -old fetuses, the parietal cells were distinguished from other type cells and these cells were chiefly crowded in the middle parts of the gastric glands after 7-day-old. Scanning electron microscopic studies. 6. The surface of gastric mucosa was covered with forms of the various protrusions by forming villi at the last few days before birth and these protrusion forms were fused and folded each other. 7. The mucosal surface was closely packed by polygonal mucous cells. The openings of gastric glands were seen as slit-like round invagination and were more numerous and increased gradually in depth after the postnatal life. The above findings indicate that prominent changes occurred in the pattern of cellular proliferation in the stomach fundus at the end of gestation. The gastric epithelium had well-defined glands composed of parietal, chief and mucous cells just before the birth. The stomach fundus, therefore, were developed morphologically as those of normal adult at fourteen days after birth.

• The Korean Journal of Pharmacology
• /
• v.15 no.1_2 s.25
• /
• pp.29-37
• /
• 1979

The tension-length relationships and reactivity of vascular smooth muscle in longitudinal strips from portal vein ana in helical strips from thoracic aorta and pulmonary artery of normotensive control and cadmium-hypertensive rabbits were studied in vitro. 1. The mean arterial pressures of non-poisoned control rabbits was $87.0{\pm}4.7 mmHg$. However, Cd-poisoned group revealed the significant increase in pressure by $109.04{\pm}2.8 mmHg$ (p<0.005). 2. By tension-length studies, strips from portal vein of Cd-poisoned group stretched a greater percent increase in length in response to an applied resting force from 0.25 to 5 g than did those from non-poisoned group. On the contrary, strips from thoracic aorta of Cd-poisoned group showed less compliant than those from control, i.e. the former underwent a less percent increase in length than the latter. Passive tension-length relations of pulmonary artery was unaffected by Cd-hypertension. 3. The force of contraction(active tension) was significantly lowered in strips from aorta of Cd-hypertensive group throughout the range of $0.5{\sim}2g$ passive tension. However, there was no significant difference in the development of active tension of portal vein or pulmonary artery of both groups. 4. The $K^+$-contraction in the portal vein, aorta and pulmonary artery of Cd-poisoned group made no difference in the active force from those of control group. 5. The force of contraction in the strips from aorta of Cd-poisoned group was significanty decreased compared to that of control. The results suggested that the alterations in vascular reactivity to contracting substances and in distensibility to passive tension were induced in the Cd-hypertensive rabbits.

• Journal of fish pathology
• /
• v.21 no.1
• /
• pp.45-56
• /
• 2008

This study was conducted to find out biological responses of bivalves exposed to organotin compound.The results of the study confirmed that tribultyltin chloride (TBTCl) induce reduction of survival rate andburrowing activity, and histopathological feature in the foot structure of the equilateral venus, Gomphinaveneriformis. The experimental period was 36 weeks. The experimental groups consisted of a control and 3TBTCl exposure groups (0.4, 0.6, 0.8 ym TBTCl L'). The survival rate and burrowing activity were record-ed daily. For histological analysis, foot tissues were fixed in Bouin' s fluid and then stained H-E stain, AB-PAS (PH 2.5) reaction and Masson's trichrome stain after having serially sectioned the tissue by paraffinmethod at thickness of 4-6 ym. The survival rate was not significantly different between the control andexposure groups for 20 weeks, but in 0.8 Um TBTCl L', it was on the decreased ever since the exposure. Theburrowing activity was not significantly different in the exposure group compared to the control up to 12weeks, but in 0.6 and 0.8 ym TBTCl L', it measured the lowest level after 20 weeks. The foot is composedof the epidermal layer, connective tissue, and muscular layer. The epidermal layer is composed of simplecolumnar, cuboidal epithelia and mucous cells. The cilia were well developed on the apical surface ofepithelium, Circular, longitudinal and transverse muscle bundle were well developed in the muscular layer.The majority mucous cells showed blue color (542c) when it subjected to AB-PAS (PH 2.5) reaction. Nohistopathological alterations in the foot were observed up to 12 weeks. After 20 weeks of exposure to 0.8 (anTBTCl L'', the foot samples of exposed G. veneriformis showed disappearance of cilia and striated borderpartially and extension of hemolymph sinus. The mucous cell increased in the marginal of foot. At 28-weekof exposure to 0.4 ym TBTCl L', it observed weekly acid (564c), neutral (264c) and mixed mucous cell. At36-week of exposure to 0.6 ym TBTCl L', it showed fragmentation of the muscle and collagen fiber bundle,and also diappearance of cilia on epithelia and edema of epithelium in 0.8 ym TBTCl L''.