Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament

OBJECTIVE: We introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL).METHODS: Fifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom’s criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months.RESULTS: In all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom’s criteria or between the single-level and two-level corpectomy groups.CONCLUSION: The satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament

OBJECTIVE: We introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL). METHODS: Fifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom’s criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months. RESULTS: In all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom’s criteria or between the single-level and two-level corpectomy groups. CONCLUSION: The satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Rotational vertebral artery syndrome treated via an anterior approach and selective decompression only

We present the case of a 38-year-old male who complained of repeated dizziness and syncope. Rotational vertebral artery syndrome (RVAS) was diagnosed via videonystagmoraphy (VNG), computed tomography angiography (CTA) and three-position digital subtraction angiography (DSA). In the neutral position, CTA and DSA revealed left vertebral artery (VA) stenosis at the C2 transverse foramen and right VA hypoplasia. When the head was turned to the right, the blood flow stopped at the C2 level. The bony structure around the VA at the C2 transverse foramen was decompressed via an anterior surgical approach, and the symptoms resolved. This case present the precise stenotic point evaluation by three-position DSA is crucial for the planning of surgical treatment.

Can Three Months of Teriparatide Be One of Treatment Options for Osteoporotic Vertebral Compression Fracture Patients? / 대한신경손상학회지

OBJECTIVE: Osteoporosis is one of the most common causes of vertebral compression fractures (VCFs). Teriparatide, a recombinant human parathyroid hormone, is the first anabolic agent for the treatment of osteoporosis. The aim of this study was to determine whether 3 months of teriparatide could be effective for patients with osteoporotic VCF at the thoracolumbar spine. METHODS: We reviewed 25 patients with thoracolumbar osteoporotic compression fractures between July 2012 and October 2016 who could be followed up for more than 1 year. Patients were divided into 2 groups depending on the use of teriparatide: 14 patients received teriparatide through subcutaneous injection (group I) and 11 patients did not receive teriparatide (group II). Demographic data, bone mineral density, hospitalization period, changes in the visual analogue scale (VAS) score, body mass index, and medical history such as smoking, alcohol, diabetes, and steroid usage were reviewed. Radiographs were also reviewed to evaluate vertebral body compression percentages and kyphotic angles. RESULTS: Overall changes of VAS score between injury and follow-up were statistically improved in both groups at 2 to 3 weeks post-injury. However, difference in VAS improvement at a specific time between the 2 groups was not statistically significant. Overall kyphotic angle and compression percentage between injury and follow-up time were increased in group II than those in group I, although the difference between the 2 groups was not statistically significant. CONCLUSION: Three-month of teriparatide did not show protective effects on progression of fractured vertebral body collapse or kyphotic changes in patients with osteoporosis.

Elemental analysis of the liver, kidney, and intestine tissues from a Hodgson's bat (Myotis formosus tsuensis)

Hodgson's bats are critically endangered in South Korea. This study analyzed the concentrations of elements in liver, kidney, and intestine tissues from a Hodgson's bat found dead in the wild. The concentrations of essential elements followed the order Fe > Zn > Cu >Mn > Se in the three tissues. Hg was detected at the highest concentrations among the non-essential elements analyzed in the liver and kidney tissues, while As was the most highly concentrated non-essential element in the intestine. To the best of our knowledge, this is the first study of tissue element concentrations in Hodgson's bats.

Lying Down Instability Undetected on Standing Dynamic Radiographs

It is well known that spinal instability should be evaluated in the standing lateral position. Standing dynamic flexion and extension radiographs are usually used to assess spinal instability. Here, we report a patient who experienced distraction instability while in the supine position rather than the standard standing position. To our knowledge, this is the first report of lying-down instability undetected on standing dynamic flexion and extension radiographs. We discuss the pathophysiological mechanism of this uncommon but possible entity and provide a review of the literature.

Tapia Syndrome after Cervical Spine Surgery

Tapia syndrome is a rare entity characterized by unilateral paralysis of the tongue and vocal cord caused by Xth and XIIth cranial nerve lesions. However, there has been no report of Tapia syndrome immediately following spine surgery. A 47-year-old man underwent posterior decompressive laminectomy for cervical stenosis. The surgery took about 117 minutes and it was uneventful. Postoperatively he developed hoarseness of voice during speech, with deviation of tongue protrusion. On laryngoscopic examination, paralysis of the left side of the tongue and the soft palate was found and complete palsy of the left vocal cord was noted. After excluding surgical cause and craniocervical lesion, a clinical diagnosis of Tapia syndrome was made. Here we report a rare case of Tapia syndrome developed after posterior approach for cervical spine surgery and discuss the possible mechanisms of this uncommon syndrome.

Tuberculous Spondylitis after Percutaneous Vertebroplasty: Misdiagnosis or Complication?

So far, there have been few previous reports of tuberculous spondylitis occurring after percutaneous vertebroplasty. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous vertebroplasty in a patient who had a history of pulmonary tuberculosis for the first time. A 58-year-old woman, who had a history of complete recovery from pulmonary tuberculosis six years previously, was hospitalized due to severe back pain after a fall. Radiological studies revealed a fresh compression fracture at the T12 thoracic vertebra. The back pain improved dramatically, and the patient was discharged two days after the vertebroplasty. However, cold sweats and a low grade fever with severe back pain developed four weeks after the procedure. Magnetic resonance imaging revealed a severe kyphosis and the T11-T12 disc space had collapsed with heterogeneous signal intensity. The results of the culture of the biopsy specimens were negative, and did not lead to identification of the causative micro-organism. However, the polymerase chain reaction for Mycobacterium tuberculosis was positive. Treatment for tuberculous spondylitis was started and she underwent posterior fusion and instrumentation from T9-L2 after the markers for infection returned to normal. After surgical intervention, the pain improved and the kyphotic deformity was corrected.

Concurrent chemoradiotherapy for elderly patients with stage III non-small cell lung cancer

PURPOSE: Combined chemoradiotherapy is standard management for locally advanced non-small cell lung cancer (LA-NSCLC), but standard treatment for elderly patients with LA-NSCLC has not been confirmed yet. We evaluated the feasibility and efficacy of concurrent chemoradiotherapy (CCRT) for elderly patients with LA-NSCLC. MATERIALS AND METHODS: Among patients older than 65 years with LA-NSCLC, 36 patients, who underwent CCRT were retrospectively analyzed. Chemotherapy was administered 3-5 times with 4 weeks interval during radiotherapy. Thoracic radiotherapy was delivered to the primary mass and regional lymph nodes. Total dose of 54-59.4 Gy (median, 59.4 Gy) in daily 1.8 Gy fractions and 5 fractions per week. RESULTS: Regarding the response to treatment, complete response, partial response, and no response were shown in 16.7%, 66.7%, and 13.9%, respectively. The 1- and 2-year overall survival (OS) rates were 58.2% and 31.2%, respectively, and the median survival was 15 months. The 1- and 2-year progression-free survivals (PFS) were 41.2% and 19.5%, respectively, and the median PFS was 10 months. Regarding to the toxicity developed after CCRT, pneumonitis and esophagitis with grade 3 or higher were observed in 13.9% (5 patients) and 11.1% (4 patients), respectively. Treatment-related death was not observed. CONCLUSION: The treatment-related toxicity as esophagitis and pneumonitis were noticeably lower when was compared with the previously reported results, and the survival rate was higher than radiotherapy alone. The results indicate that CCRT is an effective in terms of survival and treatment related toxicity for elderly patients over 65 years old with LA-NSCLC.

Concurrent Chemoradiotherapy in Elderly Patients with Locally Advanced Esophageal Carcinoma / 대한방사선종양학회지

PURPOSE: The effect of concurrent chemoradiotherapy was analyzed in elderly patients when used in the treatment of locally advanced esophageal cancer. MATERIALS AND METHODS: The retrospective analysis included 28 elderly patients aged 65 or older, with histopathologically confirmed squamous cell carcinoma of the esophagus, underwent concurrent chemoradiotherapy from January 2001 to July 2007. The squamous cell carcinoma disease stages included 8 patients (28.8%) in stage IIa, 10 patients (35.7%) in stage IIb, and 10 patients (35.7%) in stage III. Fractionated radiotherapy was performed with a 6 MV or 10 MV X-ray for 45~63 Gy (median: 59.4 Gy). Chemotherapy was applied concurrently with the initiation of radiotherapy. A 75 mg/m2 dose of Cisplatin was intravenously administered on day 1. Further, 5-FU 1,000 mg/m2 was continuously administered intravenously from days 1 to 4. This regimen was performed twice at 3-week intervals during radiotherapy. Two cycles of consolidation chemotherapy was performed after radiotherapy. RESULTS: The follow-up period was 3~72 months (median: 19 months). The treatment responses after concurrent chemoradiotherapy included a complete response in 11 patients (39.3%), a partial response in 14 patients (50.0%), and no response in 3 patients (10.7%). The overall response rate was 89.3% (25 patients). The overall 1-, 2- and 3-year survival rates were 55.9%, 34.6% and 24.2%, respectively. The median survival time was 15 months. Two-year survival rates of patients with a complete response, partial response, and no response were 46.2%, 33.0%, and 0%, respectively. The stage and tumor response after concurrent chemoradiotherapy were statistically significant prognostic factors related with survival. No treatment-related deaths occurred in this study. CONCLUSION: Concurrent chemoradiotherapy is a relatively effective treatment without serious complications in elderly patients with locally-advanced esophageal cancer.

Minimal Stitch Canalicular Repair of Canalicular Lacerations

PURPOSE: To examine the results of minimal stitch on the restoration of tissue after canalicular laceration. METHODS: We have operated using sutures of tissues around canalicular laceration by inserting bicanalicular silicone stents and minimal horizontal mattress sutures with 8-0 Vicryl in cases of canalicular laceration instead of the existing method for the past 6 years. The ages of patients ranged from 2 to 76 years (average age 39.8+/-17.4 years), with most patients in their thirties (12 patients, 40%), 30 cases underwent canalicular repair with minimal stitch and bicanalicular silicone stent insertion within 24 hours after trauma. The silicone stent was removed 3 months after the operation if the patient did not complain of epiphroa while the canalicular remained open. RESULTS: Twenty-five eyes (83.3%) showed symptom improvement and good passage in lacrimal syringing test in 4~12 months (average: 6.8+/-2.2 months) of follow-up study. Complications included one case each of fistula formation, stent prolapse, and wound infection, and two cases of canalicular stenosis. CONCLUSIONS: We recommend this method because of its satisfying success ratio.

Inhibition of trichostatin A-induced antiangiogenesis by small-interfering RNA for thrombospondin-1

Expression of thrombospondin-1 (TSP-1), which is a known inhibitor of tumor growth and angiogenesis, is reciprocally regulated by positive regulators, such as VEGF. Additionally, trichostatin A (TSA) suppresses tumor progression by altering VEGF levels and VEGF-mediated signaling. Thus, understanding TSA-regulated TSP-1 expression and the effects of altered TSP-1 levels might provide insights into the mechanism of action of TSA in anti-tumorigenesis, and provide an approach to cancer therapy. Here, we examined the effect of TSA on TSP-1 expression, and the effects of TSA-induced TSP-1 on cell motility and angiogenesis, in HeLa and bovine aortic endothelial cells. TSA remarkably increased TSP-1 expression at the mRNA and protein levels, by controlling the TSP-1 promoter activity. Both TSA and exogenous TSP-1 reduced cell migration and capillary-like tube formation and these activities were confirmed by blocking TSP-1 with its neutralizing antibody and small-interfering RNA. Our results suggest that TSP-1 is a potent mediator of TSA-induced anti- angiogenesis.

Paclitaxel and Cisplatin with Induction Chemotherapy Followed by Concurrent Chemoradiotherapy for Stage IIIB Non-small Cell Lung Cancer / 대한방사선종양학회지

PURPOSE: Combined modality therapy including chemotherapy, surgery and radiotherapy is considered the standard of care for the treatment of stage III non-small cell lung cancer (NSCLC). This study was conducted to evaluate the efficacy of paclitaxel and cisplatin with induction chemotherapy followed by concurrent chemoradiotherapy for stage IIIB NSCLC. MATERIALS AND METHODS: Between July 2000 and October 2005, thirty-nine patients with stage IIIB NSCLC were treated with two cycles of induction chemotherapy followed by concurrent chemoradiotherapy. The induction chemotherapy included the administration of paclitaxel (175 mg/m2) by intravenous infusion on day 1 and treatment with cisplatin (75 mg/m2) by intravenous infusion on day 1 every 3 weeks. Concurrent chemoradiotherapy included the use of paclitaxel (60 mg/m2) plus cisplatin (25 mg/m2) given intravenously for 6 weeks on day 43, 50, 57, 71, 78 and 85. Thoracic radiotherapy was delivered with 1.8 Gy daily fractions to a total dose of 54~59.4 Gy in 6~7 weeks (median: 59.4 Gy). RESULTS: The follow up period was 6~63 months (median: 21 months). After the induction of chemotherapy, 41.0% (16 patients) showed a partial response and 59.0% (23 patients) had stable disease. After concurrent chemoradiotherapy, 10.3% (4 patients) had a complete response, 41.0% (16 patients) had a partial response, and the overall response rate was 51.3% (20 patients). The 1-, 2-, 3-year overall survival rates were 66.7%, 40.6%, and 27.4% respectively, with a median survival time of 20 months. The 1-, 2-, 3-year progression free survival rates were 43.6%, 24.6%, and 24.6%, respectively, with median progression free survival time of 10.7 months. Induction chemotherapy was well tolerated. Among 39 patients who completed the entire treatment including chemoradiotherapy, 46.3% (18 patients) had esophagitis greater than grade 3 and 28.2% (11 patients) had radiation pneumonitis greater than grade 3. CONCLUSION: Paclitaxel and cisplatin with induction chemotherapy followed by concurrent chemoradiotherapy for stage IIIB NSCLC seems to be an effective treatment. Occurrence of esophagitis and pneumonitis represents a significant morbidity and suggests a modification of the treatment regimen, either with the chemotherapy schedule or with radiotherapy treatment planning.

The Effect of Epicatechin on the High Glucose-induced TSP-1 Expression and MMP-2 Activity in Rat Vascular Smooth Muscle Cells / 대한내분비학회지

BACKGROUND: The incidence of atherosclerosis is well correlated with the progression of type 2 diabetes mellitus. High plasma glucose in uncontrolled diabetic patients evokes many vascular complications such as atherosclerosis. Specifically, high glucose was reported to induce thrombospondin-1 (TSP-1), which activates matrix metalloproteinase-2 (MMP-2) and leads to the invasion of vascular smooth muscle cells (VSMCs) into the intima. Catechins with antioxidant effects are known to inhibit MMP-2 activity. Therefore, this study was aimed at revealing the effect of epicatechin, one of catechins, on high glucose-induced TSP-1 and the invasiveness of VSMCs. METHODS: VSMCs were primarily isolated from Sprague-Dawley rat aorta. The VSMCs were incubated with different doses (30, 100 and 300 micrometer) of epicatechin under high glucose concentration (30 mM). The TSP-1 protein and mRNA expressions were analyzed by performing Western blotting and Northern blot analyses, respectively. RT-PCR was performed to observe the MMP-2 mRNA expression. Gelatin zymography was performed for the measurement of MMP-2 activity. Invasion assays were performed to evaluate the invasiveness of VSMCs. RESULTS: Epicatechin inhibited the high glucose-induced TSP-1 expression and the MMP-2 activity in a dose-dependent manner. Also, epicatechin inhibited the high glucose-induced invasiveness of VSMCs across the matrix barrier in a dose-dependent fashion. CONCLUSION: Collectively, epicatechin may prevent the high glucose-induced proliferation and invasion of VSMCs by inhibiting the TSP-1 expression and the MMP-2 activity. Therefore, epicatechin appears to play a protective role in the development of atherosclerosis.

The Effect of Epicatechin on the High Glucose-induced TSP-1 Expression and MMP-2 Activity in Rat Vascular Smooth Muscle Cells / 대한내분비학회지

BACKGROUND: The incidence of atherosclerosis is well correlated with the progression of type 2 diabetes mellitus. High plasma glucose in uncontrolled diabetic patients evokes many vascular complications such as atherosclerosis. Specifically, high glucose was reported to induce thrombospondin-1 (TSP-1), which activates matrix metalloproteinase-2 (MMP-2) and leads to the invasion of vascular smooth muscle cells (VSMCs) into the intima. Catechins with antioxidant effects are known to inhibit MMP-2 activity. Therefore, this study was aimed at revealing the effect of epicatechin, one of catechins, on high glucose-induced TSP-1 and the invasiveness of VSMCs. METHODS: VSMCs were primarily isolated from Sprague-Dawley rat aorta. The VSMCs were incubated with different doses (30, 100 and 300 micrometer) of epicatechin under high glucose concentration (30 mM). The TSP-1 protein and mRNA expressions were analyzed by performing Western blotting and Northern blot analyses, respectively. RT-PCR was performed to observe the MMP-2 mRNA expression. Gelatin zymography was performed for the measurement of MMP-2 activity. Invasion assays were performed to evaluate the invasiveness of VSMCs. RESULTS: Epicatechin inhibited the high glucose-induced TSP-1 expression and the MMP-2 activity in a dose-dependent manner. Also, epicatechin inhibited the high glucose-induced invasiveness of VSMCs across the matrix barrier in a dose-dependent fashion. CONCLUSION: Collectively, epicatechin may prevent the high glucose-induced proliferation and invasion of VSMCs by inhibiting the TSP-1 expression and the MMP-2 activity. Therefore, epicatechin appears to play a protective role in the development of atherosclerosis.

Castleman's Disease in Unusual Location; Plasma Cell Variant

Castleman's disease, or angiofollicular lymph node hyperplasia, is a rare tumor of lymphoid origin, of unknown etiology. The expected localization is mediastinum, but rarely retroperitoneum. Localized and multicentric Castleman's diseases may be different clinical disorders, but with overlapping histological features. Recently, we experienced three cases of Castleman's disease. One case was a mixed variant, which presented as a right perirenal mass in a 23-year-old woman. The lesion was detected incidentally on computerized tomography (CT) and successfully resected. The remaining two cases were multicentric, plasma cell variants of Castleman's disease, which presented as an inguinal mass in a 29-year-old male, and as a multiple neck lymphadenopathy in a 63-year-old male, respectively. Although Castleman's disease in the perirenal retroperitoneum is extremely rare, accounting for only 2% of all reported cases, it should be included in the differential diagnosis of the mostly malignant retroperitoneal masses. We suggested that radical surgery may be avoided, given the excellent outcome after a limited excision in solitary retroperitoneal Castleman's disease.

Regulation of Vacuolar H+-ATPase c Gene Expression by Oxidative Stress

By using differential display, we identified one of the genes encoding the multi-subunit complex protein V-ATPase, c subunit gene (ATP6L), and showed alterations of the gene expression by oxidative stresses. Expression of the ATP6L gene in Neuro-2A cells was increased by the treatment with H2O2 and incubation in hypoxic chamber, implying that the expression of the ATP6L gene is regulated by oxidative stresses. To examine mechanisms involved in the regulation of the gene expression by oxidative stresses, the transcriptional activity of the rat ATP6L promoter was studied. Transcription initiation site was determined by primer extension analysis and DNA sequencing, and promoter of the rat ATP6L and its deletion clones were constructed in reporter assay vector. Significant changes of the promoter activities in Neuro-2A cells were observed in two regions within the proximal 1 kbp promoter, and one containing a suppressor was in -195 to -220, which contains GC box that is activated by binding of Sp1 protein. The suppression of promoter activity was lost in mutants of the GC box. We confirmed by electrophoretic mobility shift and supershift assays that Sp1 protein specifically binds to the GC box. The promoter activity was not changed by the H2O2 treatment and incubation in hypoxic chamber, however, H2O2 increased the stability of ATP6L mRNA. These data suggest that the expression of the ATP6L gene by oxidative stresses is regulated at posttranscriptional level, whereas the GC box is important in basal activities of the promoter.

Weakening of the repressive YY-1 site on the thrombospondin-1 promoter via c-Jun/YY-1 interaction

Thrombospondin-1 (TSP-1) level is tightly regulated at the transcriptional level. To determine the detailed molecular mechanisms of TSP-1 expression, nine serial 5'-deletion constructs of the human genomic tsp-1 promoter (nucleotides -2,220 to +756) were prepared, inserted into luciferase reporter plasmids, and transiently transfected into the Hep3B human hepatocarcinoma cell. Among the nine 5'-deletion constructs, pTSP-Luc-4 (-767~+756) had consistently decreased luciferase activity with or without PMA stimulation, whereas a further truncated construct [pTSP-Luc-4' (-407~+756)] had increased levels of expression. By searching the nucleotides from -767 to -407, a consensus binding sequence (5'-CCATTTT-3') for the repressor Yin Yang-1 (YY-1) at nucleotide -440 was identified. The suppression induced by this site was weakened in the presence of the region upstream of nucleotide -767 (pTSP-Luc-1 and -2). Nuclear protein directly bound to an oligonucleotide containing the repressive YY-1 sequence but the binding capacity of the sequence was decreased by the increased c-Jun levels. Moreover, proteins immunoprecipitated with anti-YY-1 revealed an interaction between c-Jun and YY-1 factor. These data suggest that the repressive YY-1 site of the tsp-1 promoter could not be functional via activating positive cis-elements on the upstream from this site and weakened via c-Jun/YY-1 interactions.

Transduction of Tat-Superoxide Dismutase into Insulin-producing MIN6N Cells Reduces Streptozotocin-induced Cytotoxicity

The reactive oxygen species (ROS) are considered to be an important mediator in pancreatic beta cell destruction, thereby triggering the development of insulin-dependent diabetes mellitus. In the present study, HIV-1 Tat-mediated transduction of Cu, Zn-superoxide dismutase (SOD) was investigated to evaluate its protective potential against streptozotocin (STZ) -induced cytotoxicity in insulin-producing MIN6N cells. Tat-SOD fusion protein was successfully delivered into MIN6N cells in a dose-dependent manner and the transduced fusion protein was enzymatically active for 48 h. The STZ induced-cell destruction, superoxide anion radical production, and DNA fragmentation of MIN6N cells were significantly decreased in the cells pretreated with Tat-SOD for 1 h. Furthermore, the transduction of Tat-SOD increased Bcl-2 and heat shock protein 70 (hsp70) expressions in cells exposed to STZ, which might be partly responsible for the effect of Tat-SOD. These results suggest that an increased of free radical scavenging activity by transduction of Tat-SOD enhanced the tolerance of the cell against oxidative stress in STZ-treated MIN6N cells. Therefore, this Tat-SOD transduction technique may provide a new strategy to protect the pancreatic beta cell destruction in ROS-mediated diabetes.

Human glutamate dehydrogenase is immunologically distinct from other mammalian orthologues

Five monoclonal antibodies (mAbs) that recognize human glutamate dehydrogenase (GDH) have been selected and designated as monoclonal antibodies hGDH60-6, hGDH60-8, hGDH63-10, hGDH63-11, and hGDH91-14. A total of five mAbs recognizing different epitopes of the enzyme were obtained, two of which inhibited human GDH activity. When total proteins of human homogenate separated by SDS- PAGE, were probed with mAbs, a single reactive protein band of 55 kDa, which co-migrated with purified recombinant human GDH was detected. When the purified GDH was incubated with each of the mAbs, its enzyme activity was inhibited by up to 58%. Epitope mapping analysis identified, two subgroups of mAbs recognizing different peptide fragments. Using the individual anti-GDH antibodies as probes, the cross reactivities of brain GDH obtained from human and other animal brain tissues were investigated. For the human and animal tissues tested, immunoreactive bands on Western blots appeared to have the same molecular mass of 55 kDa when hGHD60-6, hGHD60-8, or hGHD91-14 mAbs were used as probes. However, the anti-human GDH mAbs immunoreactive to bands on Western blots reacted differently on the immunoblots of the other animal brains tested, i.e., the two monoclonal antibodies hGDH63-10 and hGDH63-11 only produced positive results for human. These results suggest that human brain GDH is immunologically distinct from those of other mammalian brains. Thorough characterization of these anti-human GDH mAbs could provide potentially valuable tool as immunodiagnostic reagents for the detection, identification and characterization of the various neurological diseases related to the GDH enzyme.