Biomedical subjects

Kyongsong Kim

Publications and source records attributed to Kyongsong Kim.

10 recordsLinked to original sources

PubMed2006

Surgical pitfalls of an ultrasonic bone curette (SONOPET) in spinal surgery.

OBJECTIVE: We report our experience with the SONOPET ultrasonic bone curette. METHODS: Between September 2001 and July 2005, 546 patients underwent microscopic spinal surgeries using a high-speed drill and the SONOPET instrument. RESULTS: We encountered operative complications thought to be attributable to the use of the SONOPET in six patients (1.1%). There were five instances of dural puncture and one spinal cord injury. All dural tears occurred when the dura mater was aspirated into the tip of the SONOPET. None of the affected patients developed postoperative clinical complications because cerebrospinal fluid leakage was avoided by appropriate closure. We think that the transient spinal cord injury occurred because the vibration emanating from the SONOPET was transmitted directly to the spinal cord. Some patients experienced damage to the epidural venous plexus for reasons similar to those described above. CONCLUSION: SONOPET facilitates the removal of bone in a narrow field, such as that encountered during keyhole surgery. It aids in the removal of the lateral edge of bone and is especially useful for expanding the foramen intervertebrale or opening the lateral recess. However, its use is not without risk. To prevent dural tears and venous plexus injury, we recommend that cotton be placed between the SONOPET and important structures. To avoid spinal cord injury, we suggest that the SONOPET be inserted horizontal with the dura mater to avoid the direct transmission of vibrations emanating from the instrument to the spinal cord. SONOPET is suitable for decompression on the lateral side, but not for decompression above the spinal cord.

Adolescent↗

PubMed2006

Utility of preoperative magnetic resonance imaging myelography for identifying dural defects in patients with spinal extradural arachnoid cysts: case report.

OBJECTIVE: Preoperative magnetic resonance imaging (MRI) myelography scans demonstrated a dural defect in a 50-year-old man with an epidural arachnoid cyst who had a 29-year history of untreated weakness and numbness both lower limbs. METHODS: MRI scans showed a dorsal intraspinal extradural cystic lesion at the level from Th11 to L1. Although preoperative cine-MRI scans failed to display the dural defect, an MRI myelography scan showed cerebrospinal fluid in the subarachnoid space containing a cyst. RESULTS: The site of shunting between the subarachnoid space and the cyst was visualized as a pulsating flow void to the right of Th12. We removed the cyst wall and closed the dural defect via laminectomy. CONCLUSION: Because the preoperative MRI myelography scan correctly identified the existence and location of the dural defect, we conclude that MRI myelography is helpful for detecting dural defects in patients with epidural arachnoid cysts.

Arachnoid Cysts↗

PubMed2006

[A case of far-out syndrome: case report and review of the literature].

Far-out syndrome (FOS) is a rare disease in which the L5 nerve root is compressed by a transverse process, the sacral ala, and a bony spur at the extraforaminal zone. We report the case of patient with FOS due to a bulging disc and review the literature. This 34-year-old male experienced severe left leg pain and slight motor weakness of the left extensor digitorum. Radiographic studies revealed no abnormality in the spinal canal. The intervertebral disk bulged to the left. Because of fat it was difficult to discern the left L5 nerve root from the sacral ala in the extraforaminal zone. His symptoms failed to respond to conservative treatment and he underwent decompression of the L5 nerve root without fusion. During the operation, the left L5 nerve root was exposed by drilling the sacral ala via the left paraspinal approach. The sacral ala was removed along with the left L5 nerve root to obtain sufficient pulsation and movement of the left L5 nerve root. Neither the intervertebral joint nor the intervertebral disk was removed. The patient's symptoms disappeared immediately after surgery. Due to anatomical factors, the L5 nerve root is easily compressed and the presence of this syndrome should be considered in a differential diagnosis. Careful and appropriate decompression without fusion yielded an excellent outcome.

Adult↗

PubMed2005

Method for measuring sinus and vein pressure during surgery: technical note.

BACKGROUND: Measurement of dural sinus or drainage vein pressure is useful for determining the appropriate treatment for some patients. We report a novel measurement procedure that reduces bleeding from the needle puncture site as well as further tearing of the wall. METHODS: The vessel is punctured through the patch by gelatin sponge with fibrin sealant and a siliconized elastic needle is introduced. After obtaining the desired measurements, the needle is withdrawn through the fibrin sealant-bearing patch whose presence facilitates sealing of the puncture site. To further decrease the incidence of complications due to incomplete hemostasis, an additional identically prepared path is placed over the site. RESULTS: We have used this method in several operations and have encountered no complications. Our method also makes it possible to safely approach the drainers of pial arteriovenous malformations. CONCLUSIONS: Our method is easy and convenient and prevents the leakage of blood from the puncture site and further tearing of the venous wall.

Cerebral Veins↗

PubMed2005

Expression of hypoxia-inducible factor 1alpha and vascular endothelial growth factor in pituitary adenomas.

Hypoxia-inducible factor (HIF)-1alpha is a transcription factor in hypoxia adaptation mechanisms. In malignant tumors, HIF-1alpha upregulates vascular endothelial growth factor (VEGF) expression to induce tumor angiogenesis. Although VEGF and HIF-1alpha are expressed in pituitary adenomas, the relationships of these factors remain unclear. Therefore, we examined the expression of HIF-1alpha and VEGF using real-time RT-PCR and immunohistochemistry to clarify the relationship of these factors in pituitary adenomas. HIF-1alpha mRNA and VEGF mRNA levels in pituitary adenoma tissues from 25 operated patients were quantified using real-time RT-PCR. Some tissues were also studied by double fluorescent immunohistochemical methods. HIF-1alpha mRNA and protein were expressed in all pituitary adenomas examined. Their expression tended to be higher in GH-producing and lower in ACTH-producing tumors. VEGF mRNA and protein were also expressed in all pituitary adenomas. There was no significant correlation in the expression levels of HIF-1alpha and VEGF mRNA. The mutual expression of HIF-1alpha and VEGF was of no significance; in only a few cells were HIF-1alpha and VEGF co-localized. Our results suggest that in pituitary adenomas VEGF expression may not depend strongly on HIF-1alpha expression.

Adenoma↗

PubMed2005

Expression of hypoxia-inducible factor 1alpha and cathepsin D in pituitary adenomas.

Hypoxia-inducible factor (HIF)-1alpha is a crucial transcription factor involved in the adaptive response to hypoxia, whereas cathepsin D, which regulates angiostatin in several cancer cell lines, has been reported to be upregulated by HIF-1alpha. In order to determine the involvement of angiogenesis in pituitary adenomas, we studied the expression of both HIF-1alpha and cathepsin D in tissues from 58 patients (39 women, 19 men, ranging in age from 20 to 78 yr), sorted by histological group, and assayed by double immunohistochemistry. HIF-1alpha immunoreactivity, confined to the nucleoplasm, was present in both tumor and vascular endothelial cells. There was no difference in microvascular density (p = 0.7761) by histotype. ACTH-producing adenomas showed the lowest level of HIF-1alpha, whereas prolactin (PRL)-producing adenomas and HIF-1alpha-positive microvessels showed the highest (p < 0.001). In contrast, the lowest expression of cathepsin D was observed in PRL-producing adenomas, whereas the highest expression was detected in ACTH-producing adenomas (p < 0.0001). Imaging analysis with fluorescence double immunohistochemistry showed that HIF-1alpha-negative tumor cells did not express significantly higher levels of cathepsin D. In these poorly vascularized tumors, the hypoxic marker HIF-1alpha may not downregulate cathepsin D. The mechanisms of tumor angiogenesis and cell invasion in pituitary adenomas may differ from those in other tumor cells.

Adenoma↗

PubMed2005

Co-localization of honeycomb golgi and ACTH granules in a giant ACTH-producing pituitary adenoma.

We document the co-localization of honeycomb golgi and ACTH-immunopositive granules in giant ACTH-producing pituitary adenoma cells. A 42-yr-old woman presented with Cushing's disease and a giant adenoma that invaded the sphenoid and cavernous sinus. She underwent transsphenoidal surgery followed by radiation therapy. Some of the adenoma cells were ACTH-positive and upon electron-microscopic (EM) study most were found to contain sparse granules and no type-I filaments. In many cells the golgi complex had undergone partial or total vacuolar transformation that resulted in the appearance of honeycomb golgi. Immunohistochemical study of mirror sections of portions containing cells with honeycomb golgi revealed that the cells with honeycomb golgi showed ACTH-immunopositivity. Honeycomb golgi, which was formerly considered a morphological marker of gonadotroph adenomas in females, has previously been identified in large ACTH-producing pituitary adenomas but there has been no direct evidence that individual cells with honeycomb golgi are cells that produce ACTH. Our immunohistochemical documentation of ACTH-immunoreactivity in individual adenoma cells containing honeycomb golgi clearly confirms that honeycomb golgi is not confined only to gonadotroph adenomas in females. Rather, the existence of honeycomb golgi in cells of other adenoma types may be due to their low hormone production and/or to disturbances in the regulation of the exocytotic pathway.

Adenoma↗

PubMed2005

[Unilateral spondylolysis with spina bifida occulta of lumbar spine--case report and review of the literature].

Unilateral spondylolysis and midline defects in the posterior spinal elements attributable to spina bifida occulta (SBO) result in the unilateral floating of the vertebral arch. We report a patient with unilateral spondylolysis associated with SBO in the lumbar spine and review the literature. This 71-year-old male experienced severe left leg pain and lumbago that worsened upon walking. Radiographic studies revealed SBO and unilateral spondylolysis of L5. The dural sac and left L5 nerve root were compressed by the organization of tissues around the spondylolysis. As his symptoms failed to respond to conservative treatment, he underwent unilateral laminectomy without fusion. At operation, the left lamina of L5 was floating and unstable; the right lamina was stable. Medial facetectomy at L4/5 and excision of the left floating lamina of L5 were performed. For satisfactory decompression of the dural sac and left L5 nerve root, the cartilaginous fibrous tissue around the lysis was removed. His symptoms disappeared immediately after surgery. Although long-term follow-up is necessary, we suggest that unilateral microdecompression without fusion is a useful method to treat patients with unilateral spondylolysis with SBO.

Aged↗

PubMed2004

Preoperative identification of clearly separated double pituitary adenomas.

OBJECTIVE: Double pituitary adenomas are extremely rare. They can be divided into contiguous and clearly separated types. Most contiguous tumours are surgically removed as one tumour and the co-existence of different adenoma types can be confirmed by histological methods. In contrast, detailed preoperative neuroimaging studies can suggest the co-existence of separated multiple adenomas. In patients with multiple adenomas, surgical failure may result when one adenoma is missed during surgery. Among 600 surgical cases we encountered four patients with clearly separated double pituitary adenomas; all were highly suspect on preoperative MRI studies. PATIENTS AND RESULTS: All four patients manifested acromegalic symptoms; one patient also exhibited hyperprolactinemia and two had familial pituitary adenomas unrelated to multiple endocrine neoplasia type I (MEN-1). All underwent transsphenoidal surgery and histology confirmed the diagnosis of GH-producing plus gonadotroph adenoma in two cases and of two GH-producing adenomas each in the other two patients. CONCLUSION: Although the pathogenesis of our double adenomas remains unknown, genetic abnormalities may be involved because two patients had familial pituitary adenomas unrelated to MEN-1. When preoperative MRI is suggestive of double adenomas, careful surgical exploration is necessary to avoid missing the other adenoma because the risk of surgical failure is high, especially in patients with functioning adenomas.

Acromegaly↗

PubMed2003

Ghrelin mRNA and GH secretagogue receptor mRNA in human GH-producing pituitary adenomas is affected by mutations in the alpha subunit of G protein.

OBJECTIVE: Ghrelin and its receptor, growth hormone secretagogue (GHS) receptor (GHSR), are expressed in the normal pituitary gland and various types of pituitary adenoma. Somatic mutations in the subunit of Gs alpha protein (gsp), which led to a constitutive activation of adenylyl cyclase, are reported in GH-producing pituitary adenomas. We analysed the relationship between ghrelin mRNA and GHSR mRNA expression levels in gsp mutation-positive and -negative GH-producing pituitary adenomas. PATIENTS: Pituitary adenoma tissue was obtained at surgery from 20 patients with acromegaly. METHODS: The expression levels of human ghrelin mRNA and GHSR mRNA were quantified using a competitive RT-PCR method. To detect the gsp mutations, amplified Gs alpha subunit cDNA fragments were sequenced directly using RT-PCR method. RESULTS: There was no significant difference in the expression of ghrelin mRNA between mutation-positive and -negative adenomas. The expression of GHSR mRNA was significantly lower in gsp mutation-positive than -negative adenomas. There was a significant negative correlation between the levels of ghrelin mRNA and GHSR mRNA expression in mutation-negative adenomas; no such correlation was found in mutation-positive adenomas. CONCLUSION: These results suggest that GHSR mRNA expression is downregulated by ghrelin in gsp mutation-negative GH-producing pituitary adenomas, and that changes in intracellular signalling pathways in gsp mutation-positive GH-producing pituitary adenomas affect the expression of G protein-coupled receptors such as GHSR. The absence of negative correlation between ghrelin and GHSR expression might be induced by lowered GHSR expression in gsp mutation-positive GH-producing adenomas.

Adenoma↗