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Biomedical subjects

N H Kim

Publications and source records attributed to N H Kim.

At least 127 records · Page 7Linked to original sources
PubMed1996

Effects of oviductal fluid on sperm penetration and cortical granule exocytosis during fertilization of pig oocytes in vitro.

The effects of oviductal fluid on sperm penetration and cortical granule exocytosis in pigs were examined. Cortical granule exocytosis in oocytes matured in vivo and in vitro was observed by staining with fluorescent-labelled lectin and laser-scanning confocal microscopy. Exocytosis of matured oocytes was classified into three categories after in vitro fertilization: complete cortical granule exocytosis and even distribution of exudate in the entire perivitelline space (type I); complete exocytosis and partial distribution of exudate (type II) and incomplete cortical granule exocytosis (type III). The incidence of oocytes with type I exocytosis was higher in oocytes matured in vivo than in those matured in vitro. The addition of oviductal fluid at a concentration of 1% or 10% to the fertilization medium decreased sperm penetration and the mean number of spermatozoa present in penetrated eggs. The distribution of cortical granule exudate was not different in the presence of 1% oviductal fluid after sperm penetration from that of control groups. When oocytes were cultured for 1.5 h in medium containing 10% or 30% oviductal fluid before insemination, the incidence of monospermy increased without a decrease in sperm penetration. Preculture of oocytes in medium containing 30% oviductal fluid increased type I cortical granule reaction and increased resistance of the zona pellucida to dissolution by 0.1% (w/v) pronase at the time of sperm penetration. These results suggest that a factor(s) from the oviductal secretion is required for the complete cortical granule reaction and in the modification of the zona pellucida.

Acrosome↗
PubMed1996

Atretic encephalocele/myelocele--case reports with emphasis on pathogenesis.

Atretic encephaloceles or myelomeningoceles are frequently solid due to hamartomatous proliferation of fibrous tissue and blood vessels. Because of the fibrous nature of the tumor with no cystic cavity and unusual location with no connection to CNS, they are frequently regarded as insignificant hamartomas. Apart from this terminology, they are also described as cutaneous meningiomas or hamartomas with ectopic meningothelial elements by the presence of meningothelial cells. We report a case of atretic encephalocele in the parietal scalp of an 8 year-old boy and a case of myelomeningocele in the posterior mediastinum of a 31 year-old woman. The terms atretic encephalocele and myelomeningocele are more appropriate for these cases because they include their pathogenesis and the non-neoplastic nature of the lesion.

Adult↗
PubMed1996

Tuberous sclerosis and polycystic kidney disease. A case report.

Polycystic kidney disease is a relatively uncommon finding of tuberous sclerosis. Furthermore, the renal insufficiency by the severe polycystic kidney disease is extremely rare in tuberous sclerosis. The patient was a 27-year-old man, complaining of generalized seizure and progressive abdominal distension. His clinical features were chracterized by epilepsy, mental retardation, skin abnormalities including adenoma sebaceum, shagreen patch and ash-leaf spots. Abdominal computed tomography demonstrated numerous variable sized cysts throughout both kidneys. Clinical and laboratory findings revealed chronic renal failure due to severe polycystic kidneys. On reviewing the literature, the present case is the first report of polycystic kidneys associated with tuberous sclerosis in Korea.

Adult↗
PubMed1995

Morphometric study of the lumbar spinal canal in the Korean population.

STUDY DESIGN: The anatomic dimensions of the vertebral body and spinal canal of the lumbar spine were analyzed in Koreans. OBJECTIVES: To determine the normal dimension of the lumbar spinal canal in Koreans, to determine whether there are any racial differences in the morphometry of the lumbar spinal canal, and to provide criteria for diagnosing spinal stenosis in the Far Eastern Asian. SUMMARY OF BACKGROUND DATA: Some radiologic and anatomic studies have been conducted regarding the size of the lumbar spinal canal of whites and blacks in western and African countries. METHODS: One-thousand-eight-hundred measurements were performed on the transverse and sagittal diameters of vertebral bodies and spinal canals using complete sets of 90 lumbar vertebrae. RESULTS: The mean mid-sagittal diameter of the lumbar spinal canal in the Korean population was less than that measured in white and African populations, but there was no significant differences between the Korean, white, and African populations regarding the transverse diameter of the lumbar spinal canal. CONCLUSION: The mid-sagittal diameter of the lumbar spinal canal is narrowest in the Far Eastern Asian population; the radiologic criteria of spinal stenosis should be reconsidered for these people.

Adult↗
PubMed1995

Effects of stimulators of protein kinases A and C and modulators of phosphorylation on plasminogen activator activity in porcine oocyte-cumulus cell complexes during in vitro maturation.

Effects of phorbol myristate acetate (PMA), dibutyryl cyclic AMP (dbcAMP), 6-dimethylaminopurine (6-DMAP), and okadaic acid (OA) on plasminogen activator (PA) activity in porcine oocyte-cumulus cell complexes (POCC) in vitro were determined. Cumulus cell-enclosed oocytes were collected from 1-4 mm antral follicles and cultured in TCM-199 with 0.3% polyvinylpyrrolidone for 48 hr. PA activities in POCC were quantified using SDS-PAGE, casein-agar zymography, and densitometry. Two plasminogen-dependent lytic zones (93-96 kD and 71-79 kD) were observed in POCC. Addition of amiloride to the zymography, a competitive inhibitor of urokinase-type PA, failed to reduce activities in either zone, suggesting that the 71-79 kD band is a tissue-type PA (tPA) and the 93-96 kD band is possibly a tPA-inhibitor complex. Changes in PA activity due to the various treatments were expressed relative to the PA activity in 40 POCC. Increasing dbcAMP increased PA (P < 0.05) activity in dose-dependent fashion, whereas 6-DMAP and 10 and 100 ng/ml PMA inhibited (P < 0.05) PA activity. PA activity increased (P < 0.05) in POCC treated with up to 25 nM OA; however, activity decreased (P < 0.05) at concentrations > 75 nM. Treatment with 25 nM OA also induced the expression of an amiloride-sensitive PA (49-52 kD). Germinal vesicle breakdown and progression to metaphase II were inhibited (P < 0.05) by 2.5 mM dbcAMP and 2 mM 6-DMAP, whereas 100 ng/ml PMA and 25 nM OA inhibited (P < 0.05) only progression to metaphase II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine↗
PubMed1995

The relationship between isthmic and degenerative spondylolisthesis and the configuration of the lamina and facet joints.

Advanced degenerative change in the facet joints leads to displacement of the vertebral body, and the configuration of facet joints and lamina is closely related to the development of degenerative spondylolisthesis. For this study 103 patients and 25 controls were examined with respect to the configuration of the lamina, anteroposterior diameter of the vertebral canal, interarticular distance, interlaminar distance, disc degeneration, and degree of arthritic changes of facet joint, all as shown of plain radiography, and facet angle, interfacet distance, and contour of the canal side of the inferior articular process and lamina, as shown on computed axial tomography. The results of this study showed that those patients with a narrow facet angle were more likely to have developed degenerative spondylolisthesis. If the sum of both facet angles was less than 77.9 degree, the risk of development of degenerative spondylolisthesis was 2.5 times higher than if the sum was greater than 77.9 degree. Those with type N lamina, detected on plain radiographs, were especially likely to have developed degenerative spondylolisthesis. This suggested that degenerative spondylolisthesis may be due to the less effective check mechanism preventing a vertebra from slipping forward on the vertebra below. We recommend fusion of the degenerated spinal segments when operation is considered in cases of acute facet angle with symptoms.

Adult↗
PubMed1995

Pronuclear formation and intracellular glutathione content of in vitro-matured porcine oocytes following in vitro fertilisation and/or electrical activation.

Pronuclear formation and intracellular content of glutathione, containing reduced and oxidised forms, in porcine oocytes matured in vitro were determined following insemination and/or electrical stimulation. After insemination, sperm penetration had occurred as early as 3 h and female pronuclei had formed by 6 h with complete development by 12 h. Male pronuclear formation occurred, primarily, between 9 and 12 h after insemination. Glutathione content of the oocytes decreased following sperm penetration and remained at a depressed level until 12 h. After electrical stimulation, oocyte activation had occurred and female pronuclei had formed by 3 and 6 h, respectively. Oocyte glutathione content did not change as a result of oocyte activation. When oocytes were exposed to an electrical pulse and then spermatozoa, female pronuclear formation was observed by 3 h after stimulation/insemination. Sperm penetration was observed between 3 and 9 h. However, the incidence of male pronuclear formation observed at 12 h was extremely low, although sperm decondensation had occurred in some oocytes. Oocyte glutathione content had not decreased by 6 h following electrical activation. These results demonstrate that the changes in glutathione content in porcine oocytes following fertilisation in vitro differ from those due to electrical activation. Further, the decreased intracellular glutathione content in oocytes activated by sperm penetration appears to be due to the presence of a sperm factor.

Animals↗
PubMed1995

The biomechanical properties of deep freezing and freeze drying bones and their biomechanical changes after in-vivo allograft.

This study measured the physical properties in bending of the rat femur and compression of the rat first tail vertebra subjected to deep freezing at -80 degrees C for 2 weeks, 6 weeks, 12 weeks and freeze drying. This study also measured the mechanical changes after in vivo allograft of fresh bone, deep freezing(2, 6, 12 weeks) and freeze drying. Analysis for deep freezing groups showed a mean 7.2% decrease in bending strength and 11.0% decrease in compressive strength when compared with the control group, but there was no statistical difference in the duration of deep freezing. The groups of in vivo graft after deep freezing showed 23.1% and 22.2% decrease in bending and compressive strength. There was no statistical difference in the duration of deep freezing. The freeze drying group showed a 9.7% decrease in bending strength and no significant difference in compressive strength. The group of in vivo graft after freeze drying showed a 30.1% and a 41.3% decrease in bending and compressive strength. The above results suggested that there would be some mechanical limitation in using freeze dried graft for supporting implants.

Animals↗
PubMed1995

Use of a 64 channel computerized cardiac mapping system in arrhythmia surgery.

A multipoint and computerized intraoperative mapping system has been known to be of value in improving the results of surgery for cardiac arrhythmia. It shows great potential as a new tool in the surgical intervention of the more common and lethal types of supraventricular tachyarrhythmias such as atrial flutter and atrial fibrillation. In addition, it also enhances the ability of the investigators to map and ablate the sometimes fleeting automatic atrial tachycardia. The authors developed a 64 channel computerized cardiac mapping system using a microcomputer (Macintosh IIx) and this has been used for basic research in cardiac electrophysiology as well as in arrhythmia surgery. In this system, bipolar electrograms are obtained from 64 different cardiac sites simultaneously at a sampling rate of 1 Ksample/sec and with a continuous and total data storage of up to 30 seconds. When the reference electrode is selected, delay time from the reference point is displayed on a two dimensional diagram of the heart. This system was used in one patient who underwent a surgical ablation of a ventricular tachycardia in whom we observed a ventricular activation sequence involving a variety of rhythms over several minutes. The system design permits easy expansion to a simultaneous sampling from 256 sites. This 64-channel mapping appeared to have the potential to be of great help in our understanding of cardiac arrhythmia as well as in its diagnosis and surgical treatment.

Arrhythmias, Cardiac↗
PubMed1995

Design of an emergency teleradiology system based on progressive transmission.

In clinical surgery, there are frequent needs for communication between the house staff and the attending physician in an emergency situation. To overcome the limitation of voice communication through the telephone line, we have designed an 'emergency teleradiology system' which can be used for emergency surgical and medical decision making. This system can transmit the high quality images of CT, MRI, and other X-ray data using a PC attached to a modem through the conventional telephone line. It is based on the progressive transmission system which enables the successive update of a received image. The iterative residual coding/decoding algorithm efficiently compresses the image to maximally utilize the low bandwidth PSTN channels. This system also satisfies design requirements such as low-cost, ease of operation, fast transmission, and interactive image communication including voice. Test results using several CT, MR, and X-ray images evaluate the compression performance, image quality, transmission time and computational time of the coding and decoding processes, thus demonstrate the usefulness of this system in an emergency situation.

Algorithms↗
PubMed1995

A case of adult-onset Bartter's syndrome.

Bartter's Syndrome is characterized by renal potassium wasting with hypokalemia, metabolic alkalosis, increased renin-angiotensin-aldosterone system, normal blood pressure, resistance to the pressor effects of angiotensin II and juxtaglomerular cell hyperplasia. Most of the cases have been noted in the pediatric age group and adult-onset cases are very rare. We report a case of adult-onset Bartter's syndrome.

Adult↗
PubMed1994

Magnetic resonance imaging for the diagnosis of tuberculous spondylitis.

OBJECTIVES: The purposes of this study were to evaluate the nature of the paraspinal soft tissue mass and the location of the lesion involved using magnetic resonance imaging and to correlate these observations with surgical findings. SUMMARY OF BACKGROUND DATA: In the past, tuberculous spondylitis was diagnosed by plain radiography and since the 1970s, computed tomography has been a useful method for assessing tuberculous spondylitis. In contrast to most imaging methods, MRI has the advantages of improved contrast resolution for bone and soft tissues and versatility of direct imaging in multiple planes. METHODS: Medical records and magnetic resonance imaging studies of 22 patients with bacteriologically and/or histologically proved tuberculous spondylitis were reviewed. In each patient, the numbers of vertebrae involved were evaluated as well as which columns of vertebrae were affected and the signal intensities of lesions. In addition, an attempt was made to determine if granulation tissue differed from the abscess based on magnetic resonance imaging appearance and to compare the outcome with surgical findings. RESULTS: The average number of vertebrae involved per patient was 2.8 and T8 and T9 were the vertebrae most frequently affected. The destruction of vertebrae and discs was easily identified in both sagittal and axial planes. The peripheral margins were exclusively enhanced in all cases. Of particular interest, the posterior aspect of the vertebral body was predominantly involved. Mostly the involvement of both anterior and middle columns was noted. With the aid of intravenous administration of magnetic resonance contrast agents, magnetic resonance imaging was highly accurate in distinguishing the granulation tissue from the cold abscess. CONCLUSIONS: Magnetic resonance imaging demonstrated excellent images of bone destruction and soft tissue mass, and provided information in multiple planes, thereby delineating the extent of involvement in tuberculous spondylitis. Magnetic resonance imaging is most helpful in planning a surgical approach to tuberculous spondylitis.

Adult↗
PubMed1994

Inhibitory mechanism of Ca2+ on the hemolysis caused by Vibrio vulnificus cytolysin.

Calcium in millimolar concentrations protected mouse erythrocytes from hemolysis caused by Vibrio vulnificus cytolysin without affecting the release of intracellular K+ from the cells. This effect was maximal at 25 mM CaCl2. The protection was not absolute and could be partially overcome by increased concentrations of cytolysin. Calcium failed to block both the binding and oligomer formation of cytolysins on the erythrocyte membrane. After pore formation, the continued presence of calcium is required for the prevention of hemolysis. There was hardly any inflow of calcium into the erythrocytes through pores as measured by 45Ca2+ uptake. The presence of calcium after the abolition of Ca2+ gradient by ionomycin cannot inhibit the hemolysis caused by cytolysin. These results suggest that calcium exerts its major inhibitory effect on V. vulnificus cytolysin-induced hemolysis as an osmotic protectant, and that cytolysin may become an useful tool for permeabilizing cells selectively for small ions such as potassium or sodium while preventing the Ca2+ flow.

Animals↗
PubMed1994

Morphometric study of the pedicles of thoracic and lumbar vertebrae in Koreans.

STUDY DESIGN: The shape and size of the pedicles of the human spine differs within different races. The authors studied the diameters and angles of the spine pedicle from the T1 to L5 levels in Koreans. The following measurements were made 1) transverse diameter, 2) superoinferior diameter, 3) anteroposterior pedicle angle, 4) horizontal pedicle angle, and 5) pedicle axis angle. OBJECTIVES: This study obtained indices of pedicle morphology in Koreans to use in transpedicular screw fixation and to explain the difference between other races and Koreans. SUMMARY OF BACKGROUND DATA: Internal fixators for vertebrae fixation have been developed. Knowledge of pedicle morphology is essential for pedicle screw use. The use of pedicle screws in Asians is questionable. Few reports exist regarding pedicle morphology, and in those few reports, the pedicle isthmus diameter, pedicle angles, and the depth to the anterior cortex are emphasized. METHODS: The following measurements of the diameter and length of the human cadaver pedicle were done with vernier and dial calipers: 1) transverse diameter of pedicles, 2) superoinferior diameter of pedicles, 3) anteroposterior pedicle angle, and 4) horizontal pedicle and pedicle axis angles. RESULTS: The widest transverse diameter of the pedicle was seen at the L5 level and the narrowest was at the T4 level. The widest superoinferior diameter of the pedicle was seen at the T12 level, the narrowest was at the T1 level. In the transverse plane, the angles of the pedicles of T11 and T12 were faced laterally. The anteroposterior angle increased rapidly at the T4 level, with the T1 level having the greatest. In the sagittal plane, the horizontal angle of the lumbar vertebra was almost parallel to the horizontal plane. The pedicle axis was longest at the L3 level and shortest at the T1 level. In all areas, the transverse diameter of the pedicle in males was wider than the that in the female. CONCLUSIONS: The results suggest that using 6-mm screws can violate the cortex of the pedicles in a significant number of levels of the upper lumbar spine. Using a screw longer than 40 mm is dangerous in the lower thoracic spine of a Korean. A statistical difference exists between the transverse diameter of the pedicles of Westerners and Koreans.

Adult↗
PubMed1994

Electrodiagnostic and histologic changes of graded caudal compression on cauda equina in dog.

STUDY DESIGN: An animal model of lumbar spinal stenosis, in which the pathophysiology of this condition could be examined, was retrieved according to Delamarter's method. OBJECTIVES: The purpose of this study was to develop a reproducible animal model of lumbar spinal stenosis to further understanding of the long-term electrophysiologic changes, and to detect prognostic indices of the long-term anatomic and physiologic status of chronic compression of the cauda equina. SUMMARY OF BACKGROUND DATA: Somatosensory-evoked potentials and bulbocavernosus reflexes revealed abnormalities before neurologic signs and symptoms appeared. If delayed somatosensory-evoked potentials and bulbocavernosus reflexes were recovered with the lapse of time, neurologic findings showed gradual recovery. The loss of somatosensory-evoked potentials, bulbocavernosus reflexes, and neurologic, histological abnormalities occurred at 50% constriction of the cauda equina; at the same time, that was the critical point of possible recovery. METHODS: Four experimental groups, each containing six dogs, were studied. One group had a laminectomy of the sixth and seventh lumbar vertebrae only; these animals served as controls. In the three other groups, a laminectomy was performed, and the cauda equina was constricted by 25%, 50%, or 75% to produce chronic compression according to Delamarter's method. RESULTS: Somatosensory-evoked potentials and bulbocavernosus reflexes revealed neurologic abnormalities before the appearance of neurological signs and symptoms. Constriction of more than 50% was the critical point; it resulted in loss of evoked potentials, reflexes, neurologic deficits, and histological abnormalities. CONCLUSION: To accurately forecast prognosis of chronic cauda equina compression, the combined diagnostic study of somatosensory-evoked potential with bulbocavernosus reflex is recommended.

Animals↗
PubMed1994

The Orthofix external fixator for fractures of long bones.

The Orthofix external fixator was used to treat 112 fractures of the long bones in 101 patients, and 22 patients with infected nonunions. Our results compared favourably with those reported in other series where external fixation was used. The overall rate of uncomplicated union was 69.6% with 24.1% of patients requiring a further operation. The overall incidence of nonunion (30.4%) was due to the relatively large number of severe open fractures in the series. The apparatus was simple to apply, and safe and effective in practice. We recommend its use for the primary treatment of open and segmental fractures, and for infected nonunion.

Adolescent↗