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Biomedical subjects

D I Kim

Publications and source records attributed to D I Kim.

At least 55 records · Page 3Linked to original sources

Transient improvement of pyruvate metabolism after coenzyme Q therapy in Kearns-Sayre syndrome: MRS study.

Coenzyme Q therapy has been used to support metabolic derangements in patients with mitochondrial encephalomyopathies. Biochemical analysis of the living human brain can be performed by magnetic resonance spectroscopy (MRS). We report upon a KSS patient who was serially imaged with localized proton MRS to monitor the efficacy of CoQ treatment. A 17-year-old girl with KSS was serially imaged with localized proton MRS performed on a GE 1.5 T SIGNA MRI/MRS system. The elevated lactate contents of lesions decreased after one month of CoQ therapy but were re-elevated 10 months after treatment. We conclude that MRS presents us with a powerful tool for monitoring the effects of therapeutic trials in mitochondrial encephalomyopathies.

Adolescent↗

Prevalence of foam cells and helper-T cells in atherosclerotic plaques of Korean patients with carotid atheroma.

BACKGROUND: Inflammation and activation of immune cells have important roles in the pathogenesis of atherosclerosis. We analyzed the involvement of various immune cells in the pathogenesis of atherosclerosis. METHODS: We investigated the presence of foam cells, lymphocytes and killer cells in 11 atherosclerotic plaque specimens removed from Korean patients who underwent carotid endoarterectomy. Atherosclerotic plaques were analyzed by immunohistochemistry using monoclonal antibody specific to foam cells (anti-CD68), pan-T cells (anti-CD3), helper-T cells (anti-CD4), cytotoxic T cells (anti-CD8), granular component of killer cells (anti-TIA-1) and pan-B cells (anti-CD20). RESULTS: Analysis revealed a general infiltration of immune cells not only in atherosclerotic plaques but also in the vascular wall adjacent to the plaque. Heavy infiltration of CD68+ macrophage was observed in all cases. In addition, significant infiltration of CD3+ T-lymphocytes was observed in all cases, while CD20+ B-cells were observed in only a few cases. Majority of the CD3+ cells was found to be CD4+ helper-T cells. CD8+ cytotoxic T cells and TIA-1+ cells were less prominent. CONCLUSION: Analysis of the human atherosclerotic plaques suggested that helper-T cells and foam cells had a major role in the plaque development.

Aged↗

Preservation of renal function in reimplantation of renal artery of abdominal aortic aneurysm.

Intraoperative administration of diuretics and renal hypothermia with cold (4 degrees C) heparinized Ringer's lactate were useful methods for preserving renal function during warm ischemia time. 54-year and 74-year-old men were diagnosed as abdominal aortic aneurysm. Their left renal and accessory left renal arteries originated from the border zone of the aneurysm. We reported two cases of reimplantation of the renal artery in abdominal aortic aneurysm without deterioration of renal function.

Aged↗

Hydroxyurea induces a senescence-like change of K562 human erythroleukemia cell.

Hydroxyurea, a differentiation-inducing agent of human erythroleukemia K562 cells, is commonly used to treat some types of leukemia. However, the mechanism for its therapeutic effect is not clearly understood yet. In this study, we have observed an interesting effect of hydroxyurea on tumor cells: an induction of senescence-like changes. Human erythroleukemia K562 cells, when treated with hydroxyurea for 7 days or more, underwent a change into phenotypically senescent cells together with a reduction of hemoglobin generation, a differentiation marker. The hydroxyurea-treated cells showed positive senescence associated-beta-galactosidase staining, a senescence index, and the accumulation of cdk (cyclin dependent kinase) inhibitors, such as p16INK4a, p21Waf1, and p27Kip1, implicated in cellular senescence. Nonetheless, these changes were not accompanied by DNA fragmentation. Taken together, we summarize that the long-term treatment of cancer cells with hydroxyurea can induce cellular senescence different from differentiation or programmed cell death.

Antineoplastic Agents↗

Synthesis and biological activity of KCB-328 and its analogues: novel class III antiarrhythmic agents with little reverse frequency dependence.

A series of 3,4-dimethoxyphenethylamine derivatives was prepared, and their prolongation effects on effective refractory period of contractile response (ERPc) and action potential duration (APD) in isolated guinea-pig papillary muscles at 1 Hz and 3 Hz were examined. SAR studies led to the identification of KCB-328 (51) which is a novel class III antiarrhythmic agent with little reverse frequency dependence.

Animals↗

Perfusion impairments in infantile autism on technetium-99m ethyl cysteinate dimer brain single-photon emission tomography: comparison with findings on magnetic resonance imaging.

The neuro-anatomical substrate of autism has been the subject of detailed investigation. Because previous studies have not demonstrated consistent and specific neuro-imaging findings in autism and most such studies have been performed in adults and school-aged children, we performed a retrospective review in young children in search of common functional and anatomical abnormalities with brain single-photon emission tomography (SPET) using technetium-99m ethyl cysteinate dimer (ECD) and correlative magnetic resonance imaging (MRI). The patient population was composed of 23 children aged 28-92 months (mean: 54 months) who met the diagnostic criteria of autism as defined in the DSM-IV and CARS. Brain SPET was performed after intravenous injection of 185-370 MBq of 99mTc-ECD using a brain-dedicated annular crystal gamma camera. MRI was performed in all patients, including T1, T2 axial and T1 sagittal sequences. SPET data were assessed visually. Twenty patients had abnormal SPET scans revealing focal areas of decreased perfusion. Decreased perfusion of the cerebellar hemisphere (20/23), thalami (19/23), basal ganglia (5/23) and posterior parietal (10/23) and temporal (7/23) areas were noted on brain SPET. By contrast all patients had normal MRI findings without evidence of abnormalities of the cerebellar vermis, cerebellar hemisphere, thalami, basal ganglia or parietotemporal cortex. In conclusion, extensive perfusion impairments involving the cerebellum, thalami and parietal cortex were found in this study. SPET may be more sensitive in reflecting the pathophysiology of autism than MRI. However, further studies are necessary to determine the significance of thalamic and parietal perfusion impairment in autism.

Autistic Disorder↗

Quantitative assessment of cerebrospinal fluid hydrodynamics using a phase-contrast cine MR image in hydrocephalus.

This investigation was undertaken to characterize CSF flow at the level of the aqueduct of Sylvius with a phase-contrast cine MR pulse sequence in 28 healthy volunteers. Sixteen patients with obstructive hydrocephalus and 11 patients with normal pressure hydrocephalus (NPH) were investigated with the same sequence before and after CSF diversion. The peak CSF flow velocity and stroke volume in the aqueduct increased significantly in the NPH group and decreased significantly in the obstructive hydrocephalus group. After lumboperitoneal shunting in the NPH group, the retrograde flow of CSF was anterogradely converted and the peak flow velocities decreased somewhat. The clinical diagnosis of NPH was well correlated with the results of cine MRI. After endoscopic III ventriculostomy in the obstructive hydrocephalus group we noted increased CSF flow velocity with markedly increased stroke volume at the prepontine cistern. Phase-contrast cine MR is useful in evaluating CSF dynamics in patients with hyperdynamic aqueductal CSF or aqueductal obstruction.

Adult↗

Synthesis of (25R)-26-hydroxy-15-ketosterols.

(25R)-3beta,26-Dihydroxy-5alpha-cholest-8(14)-en-15-one (1) and (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2) were synthesized from (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-ene (4). Oxidation of 4 with CrO3-3,5-dimethylpyrazole at -20 degrees C gave (25R)-3beta,26-dibenzoyloxy-5alpha,14alpha-chole st-16-en-15-one (5) along with (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-16alpha+ ++,17alpha-epoxide (6). Oxidation of 5 with selenium dioxide afforded (25R)-3beta,26-dibenzoyloxy-5alpha-cholest-8(14),16-++ +dien-15-one (7) and (25R)-3beta,26-dibenzoyloxy-5alpha,14beta-choles t-16-en-15-one (8). Selective hydrogenation of 7 followed by hydrolysis in alcoholic potassium hydroxide yielded (25R)-3beta,26-dihydroxy-5alpha-cholest-8(14)-en-15-one (1). Hydrolysis of 5 and 8 in alcoholic potassium hydroxide provided (25R)-3beta,26-dihydroxy-5alpha,14beta-cholest-16-en-1 5-one (2).

Magnetic Resonance Spectroscopy↗

Endoscopic hemostasis in sphincterotomy-induced hemorrhage: its efficacy and safety.

BACKGROUND AND STUDY AIMS: Hemorrhage is induced in approximately 0.5-12% of endoscopic biliary sphincterotomy (ES) procedures. We prospectively investigated the risk factors for ES-induced hemorrhage and evaluated the safety as well as the effectiveness of endoscopic hemostasis. PATIENTS AND METHODS: The study included 1304 patients who underwent ES between July 1996 and June 1998. Epinephrine spray was used initially for hemostatic treatment. If bleeding persisted, an epinephrine injection was given consecutively. In patients with exposed vessels, epinephrine injection followed by alcohol injection was given. RESULTS: ES-induced hemorrhage occurred in 136 (10.4%) patients. The type of sphincterotome used (needle-knife sphincterotome, P=0.025) and the cutting speed (the so-called "zipper" cut, P = 0.049) were revealed as significant variables with regard to the occurrence of bleeding. Mild, moderate, and severe bleeding were noted in 108 (79.4%), 22 (16.2%), and six (4.4%) patients, respectively. Once bleeding occurred, patients with an associated ampullary lesion (impacted stone or cancer) or with coagulopathy were more likely to bleed profusely. Initial hemostasis was achieved in all patients. However, rebleeding occurred in eight patients who were initially classified as having moderate or severe bleeding. Finally, ES-induced hemorrhage was successfully controlled in all patients after 1-3 treatment sessions (mean 1.1 sessions). The difference in the incidence of complications between the groups treated or not treated by endoscopic hemostasis was not statistically significant. CONCLUSIONS: ES-induced hemorrhage occurred in 10% of the patients studied. The use of needle-knife sphincterotomy and the cutting speed were independent risk factors for the occurrence of bleeding. Once bleeding occurred, its severity was affected by an associated ampullary lesion (impacted stone or cancer) or coagulopathy. Endoscopic hemostasis with epinephrine and/or alcohol was effective and safe in ES-induced hemorrhage.

Biliary Tract Diseases↗

Simple, efficient and successful vitrification of bovine blastocysts using electron microscope grids.

This study demonstrates that higher survival of vitrified-thawed bovine blastocysts can be obtained using electron microscope (EM) grids as embryo containers at freezing, rather than plastic straws. In-vitro produced day 7 bovine blastocysts after in-vitro fertilization (IVF) were vitrified on grids or in straws with EFS40 freezing solution and their survival after thawing was compared. Embryo survival was assessed as re-expanded and hatched rates at 24 and 48 h after thawing respectively. When the effects of exposure to vitrification solution and chilling injury from the freezing procedure were examined, embryo survival in the exposure group (24 h: 100, 48 h: 73.3%) was not different compared with that in the control group (100, 84.4%). After vitrification, the hatched rate of the EM grid group 48 h after thawing (67.8%) was significantly higher than that of the straw group (53.3%) (P < 0.05). Fast developing embryos (expanded blastocyst and early hatching blastocyst stage) showed better resistance to freezing than delayed ones (early blastocyst stage), irrespective of embryo containers (early: 24 h, 57.1 and 48 h, 24.4%; expanded: 84.7 and 60.6%; early hatching: 91.7 and 80.0%) (P < 0.001). When using expanded and early hatching blastocysts, embryo survival rates in the vitrification-EM grid group (67.8, 95.0% respectively) were significantly higher than that of the vitrification-straw group (53.0, 65.0%) at 48 h.

Animals↗

Evaluation of reperfusion and recovery of brain function before and after intracarotid arterial urokinase therapy in acute cerebral infarction with brain SPECT.

PURPOSE: Perfusion defects can be demonstrated reliably at an early stage with regional cerebral blood flow studies using SPECT. The administration of thrombolytic therapy in ischemic stroke is targeted at restoring cerebral perfusion immediately, leading to salvage of ischemic penumbra, smaller infarct size, and improved clinical outcome. This study considered the role of brain perfusion SPECT in the evaluation of reperfusion and brain function recovery of the infarcted area after early recanalization (less than 6 hours) of the occluded artery using intracarotid arterial urokinase therapy (ICAU). METHODS: Intracranial artery occlusion was confirmed in seven patients using emergency carotid angiography performed within the initial 6-hour period. Intracarotid arterial urokinase (500,000 to 800,000 units) was administered into the occluded arterial system (the left middle cerebral artery in four and the right middle cerebral artery in three patients). CT scanning was performed when the patients arrived in the emergency department and was repeated 24 to 48 hours after ICAU and at 7 days or earlier if clinically indicated. All patients had two SPECT studies, the first before urokinase administration and the second 24 or 48 hours later. RESULTS: Complete recanalization of the occluded vessels was seen in one patient after ICAU, effective partial recanalization was achieved in four patients, and minimal recanalization occurred in the other two. Before ICAU, Tc-99m HMPAO brain SPECT showed decreased uptake of the infarcted area in all patients, whereas the follow-up brain SPECT performed 24 or 48 hours after ICAU revealed improvement in the uptake of the recanalized area on qualitative and semiquantitative assessments using an asymmetry index, suggestive of brain function recovery and clinical improvement. Hemorrhagic transformation adjacent to the reperfused regions occurred in two patients with partial recanalization of the left middle cerebral artery. CONCLUSIONS: Reperfusion of the recanalized area and brain function recovery could be achieved if the occluded artery is recanalized within the initial 6-hour period using ICAU, and this was documented using brain perfusion SPECT without a delay in the therapeutic time window. Because the number of patients we studied was limited, further study is necessary to evaluate the effect of ICAU and to determine its prognostic significance.

Acute Disease↗

The prognosis for control of seizures with medications in patients with MRI evidence for mesial temporal sclerosis.

PURPOSE: Mesial temporal sclerosis (MTS) is the most common and important pathology in temporal lobe epilepsy (TLE), and its presence in magnetic resonance imaging (MRI) scans is strongly correlated with a successful surgical outcome. Despite the general assumption that patients with MTS respond poorly to medication, the long-term prognosis for such patients has not yet been investigated. We studied the overall clinical prognosis of patients with MTS and analyzed the factors related to the degree of medical responsiveness. METHODS: Case patients were actively followed up at the Yonsei Epilepsy Clinic in Seoul, Korea, for >2 years. A structured interview and a thorough clinical evaluation were conducted. MRI scans, at the field strength of 1.0 or 1.5 Tesla, were performed with T1- and T2-weighted coronal and axial spin-echo images. All coronal slices were < or = 5-mm thick with no gap. Two neurologists and one radiologist determined the presence of MTS in MRIs by visual analysis. RESULTS: The MTS group consisted of 104 patients. Of these, 26 (25%) were completely controlled with adequate therapy, and 40 (38%) were intractable, despite aggressive anticonvulsant polytherapy. The remaining 37% had their seizure frequencies reduced by > or = 50%, but were not seizure free. The age of seizure onset was significantly younger in the intractable group than in the well-controlled group. Patients with a history of febrile convulsions or with epileptiform discharges in their electroencephalogram (EEG) had poorer seizure control (p < 0.05) than those who did not. Among the 16 patients who had no previous treatment, five (31%) became seizure free, and two were intractable. CONCLUSIONS: Not all patients with MTS are medically intractable; 25% of the patients in our study achieved complete control while receiving medication. Poor seizure control was related to an early age of seizure onset, a history of febrile convulsions, and epileptiform discharges on the EEG.

Adolescent↗

Venous dynamics in leg lymphedema.

To determine whether there is anatomical and/or functional impairment to venous return in patients with lymphedema, we examined venous dynamics in 41 patients with unilateral leg lymphedema. A Volometer was used for computer analysis of leg volume, a color Duplex Doppler scanner was used to determine deep vein patency and skin thickness, and Air-plethysmography was used to assess ambulatory venous pressure, venous volume, venous filling index and the ejection fraction. In the lymphedematous leg, volume and skin thickness were uniformly increased (126.4 +/- 21.3% and 156.9 +/- 44.5%) (mean +/- S.D.), respectively. The ambulatory venous pressure was also increased (134 +/- 60.7%) as was the venous volume (124.5 +/- 37.5%), and the venous filling index (134.5 +/- 50.5%). The ejection fraction was decreased (94.9 +/- 26.1%). Greater leg volume correlated with increased venous volume and venous filling index (values = 0.327, 0.241, respectively) and decreased ejection fraction (r = -0.133). Increased subcutaneous thickness correlated with increased venous filling index and venous volume (r = 0.307, 0.126, respectively) and decreased ejection fraction (r = -0.202). These findings suggest that soft tissue edema from lymphatic stasis gradually impedes venous return which in turn aggravates the underlying lymphedema.

Female↗

Changes in lymphatic function after complex physical therapy for lymphedema.

Twenty-two extremities of 19 lymphedema patients (6 arms, 16 legs) were treated by 2 weeks of complex physical therapy (CPT) and self home maintenance therapy (bandage/wearing of elastic garment and exercise). In addition to the clinical response of volume reduction before and 3 months after CPT, we analyzed the functional changes of the peripheral lymphatic system by use of lymphoscintigraphy (LS). Before CPT, the main LS findings of lymphedema included dermal backflow (100%), absent or faintly visualized regional lymph nodes (95.5%), presence of collateral lymphatic vessels (68.2%), and no or barely visualized lymphatic vessels (27.3%). LS findings suggesting improved lymphatic function after CPT were a decrease in dermal backflow (72.7%), an increase in radioisotope uptake by lymphatic vessels (27.3%), and an increase in radioisotope uptake by lymph nodes (9.1%). 81.8% of limbs showed improved lymphoscintigraphic findings and no change in 9.1%. In the others (9.1%), LS findings appeared worse. There was, however, no correlation between LS "improvement" and the amount of limb volume reduction.

Antimony↗

MRI of germinomas arising from the basal ganglia and thalamus.

We reviewed the MRI findings of germinomas originating from the basal ganglia, thalamus or deep white matter in 13 patients with 14 germinomas, excluding those in the suprasellar or pineal regions. Ten cases were confirmed as germinomas by stereotaxic biopsy, three by partial and one by total removal of the tumour. Analysis was focussed on the location and the signal characteristic of the tumour, haemorrhage, cysts within the tumour and any other associated findings. Thirteen of the tumours were in the basal ganglia and one in the thalamus. Haemorrhage was observed in seven patients, while twelve showed multiple cysts. Associated ipsilateral cerebral hemiatrophy was seen in three patients. The signal intensity of the parenchymal germinomas was heterogeneous on T1- and T2-weighted images due to haemorrhage, cysts and solid portions. We also report the MRI findings of germinomas in an early stage in two patients.

Adolescent↗

Idiopathic hypertrophic pachymeningeal lesions: correlation between clinical patterns and neuroimaging characteristics.

Nine patients with intracranial pachymeningeal thickening and enhancement on magnetic resonance imaging (MRI) completed a short-term clinical and MRI follow-up study. Based on clinical pictures, 4 of them were found to have spontaneous intracranial hypotension (SIH) and the remaining 5 had idiopathic intracranial pachymeningitis (IIP). Both groups were compared regarding their clinical and MRI characteristics. In 4 patients with SIH, gadolinium-enhanced T1-weighted images (WI) showed a diffuse and even enhancement of the entire intracranial and spinal dura mater. These thickened dura was slightly hyperintense on T2-WI. They had a favorable prognosis. In 2 patients with IIP, MRI demonstrated a relatively focal and even thickening and enhancement of the intracranial dura which was slightly hyperintense with a central hypointense area on T2-WI. These patients showed a very favorable course with or without steroid pulse therapy. In the remaining 3 patients with IIP, MRI depicted a focal, uneven enhancement of the intracranial dura which was relatively hypointense on T2-WI. Two of them with prolonged symptoms had a remitting and relapsing course, and 1 had a favorable outcome. In spite of current limitations in identifying the underlying causes of idiopathic pachymeningeal abnormalities, MRI can characterize the different patterns of pachymeningeal thickening. These findings may also correlate with the clinical picture and may be useful in predicting the response to treatment and prognosis.

Adult↗

Facial nerve schwannomas: CT and MR findings.

The present study was undertaken to analyze the radiologic findings of intratemporal and extratemporal schwannoma (ITS & ETS). We retrospectively reviewed the CT (9 cases), MR (3 cases) and medical records of 10 facial schwannoma patients. After classifying these into ITS and ETS, radiologic and clinical findings were analyzed. The most common clinical manifestations were facial nerve dysfunction (6/6 cases, 100%) and hearing impairment (5/6 cases, 83.3%) in ITS and parotid mass (4/4 cases, 100%) in ETS. Geniculate ganglion (GG) was the most commonly involved segment of ITS (5/6 cases, 83.5%). On CT, ITS arising in GG (4 cases) showed erosion of the petrous bone (4 cases), cochlea (3 cases), lateral semicircular canal (1 case) and ossicles (3 cases). ITS arising in the mastoid segment (1 case) showed the destruction of the jugular plate and external auditory canal wall. All three ITS in which MRI was performed showed iso- to hypointensity on T1WI, hyperintensity on T2WI and well-enhanced on post-enhanced T1WI. ETS showed various findings, but all four ETS were located in the posterolateral portion of the retromandibular vein and extended toward the stylomastoid foramen. In conclusion, ITS shows the schwannoma on MR. ETS shows various findings. However, if the tumor is located along the extratemporal facial nerve course, then facial schwannoma may be suspected.

Adult↗

Isolated bilateral abducens nerve palsy due to carotid cavernous dural arteriovenous fistula.

Carotid cavernous dural arteriovenous fistula (DAVF) usually presents with conjunctival injection, proptosis, loss of visual acuity and ophthalmoplegia. There have been some carotid cavernous DAVF case reports presenting with isolated oculomotor, abducens and trochlear nerve palsy. We experienced a patient presenting with bilateral abducens nerve palsy and no other ocular signs who was diagnosed as carotid cavernous DAVF after conventional angiography. According to this case, carotid cavernous DAVF should be considered in the differential diagnosis of isolated bilateral abducens nerve palsy, in which case conventional angiography may be helpful in diagnosis.

Abducens Nerve↗