Biomedical subjects

Kiwon Lee

Publications and source records attributed to Kiwon Lee.

4 recordsLinked to original sources

PubMed2007

Hyperperfusion syndromes: insight into the pathophysiology and treatment of hypertensive encephalopathy.

Hypertensive encephalopathy is one of the manifestations of a hypertensive crisis. It is not the absolute value of the blood pressure that causes the encephalopathy, rather the presence of an abrupt rise in pressure. In terms of clinical and radiographic findings, there are many similarities among a group of entities, including hypertensive encephalopathy, eclampsia, and immunosuppressant neurotoxicity. Hyperperfusion syndromes may represent these clinical disease states that may share the same pathophysiology. Magnetic resonance imaging fluid attenuated inversion recovery sequences have recognized the prominent cortical involvement of the disease that had been previously missed on computed tomography. Studies have found cortical involvement in 94% of their patients, particularly in mild cases. Animal models demonstrate endothelial damage and enhanced pinocytosis in the cortex as reasons why edema may begin in that region of the brain. Patients diagnosed with hypertensive encephalopathy should be diagnosed and treated promptly in order to avoid further neurological complications. The mean arterial pressure should be lowered by 20% to 25% within the first hour of patient presentation, followed by further gradual reduction in blood pressure over the following 24 hours. Hypertensive emergency in acute ischemic stroke should be managed with more caution. According to the 2003 American Stroke Association treatment guidelines, for patients with ischemic stroke not eligible for thrombolytic therapy, target blood pressures are a diastolic blood pressure <120 mmHg and systolic blood pressure <220 mmHg. The systolic pressure must be <185 mmHg and diastolic pressure <110 mmHg at all times if eligible for thrombolytic therapy.

Animals↗

PubMed2006

Vav3 oncogene is overexpressed and regulates cell growth and androgen receptor activity in human prostate cancer.

The purpose of this research was to investigate the role of Vav3 oncogene in human prostate cancer. We found that expression of Vav3 was significantly elevated in androgen-independent LNCaP-AI cells in comparison with that in their androgen-dependent counterparts, LNCaP cells. Vav3 expression was also detected in other human prostate cancer cell lines (PC-3, DU145, and 22Rv1) and, by immunohistochemistry analysis, was detected in 32% (26 of 82) of surgical specimens of human prostate cancer. Knockdown expression of Vav3 by small interfering RNA inhibited growth of both androgen-dependent LNCaP and androgen-independent LNCaP-AI cells. In contrast, overexpression of Vav3 promoted androgen-independent growth of LNCaP cells induced by epidermal growth factor. Overexpression of Vav3 enhanced androgen receptor (AR) activity regardless of the presence or absence of androgen and stimulated the promoters of AR target genes. These effects of Vav3 could be attenuated by either phosphatidylinositol 3-kinase (PI3K) inhibitors or dominant-negative Akt and were enhanced by cotransfection of PI3K. Moreover, phosphorylation of Akt was elevated in LNCaP cells overexpressing Vav3, which could be blocked by PI3K inhibitors. Finally, we ascertained that the DH domain of Vav3 was responsible for activation of AR. Taken together, our data show that overexpression of Vav3, through the PI3K-Akt pathway, inappropriately activates AR signaling axis and stimulates cell growth in prostate cancer cells. These findings suggest that Vav3 overexpression may be involved in prostate cancer development and progression.

Blotting, Western↗

PubMed2006

Nosocomial infections in neurocritical care.

Development of nosocomial infections is a commonly encountered problem for critically ill patients. Approximately half of all nosocomial pneumonias in the neurointensive care unit (NICU) are associated with ventilator-associated pneumonia. Prompt diagnosis with appropriate specimen analysis is required in order to prevent increased morbidity. Catheter-related blood stream infection imposes financial as well as medical implications. Multifaceted interventions are helpful to ensure adherence with evidence-based infection control guidelines. Urosepsis occurs in approximately 16% of patients. Colonized patients without evidence of infection do not require treatment, but the indwelling catheter should be changed. NICU patients have increased risk of developing cerebrospinal fluid infection due to frequent placement of external ventricular drains. The incidence of ventriculostomy-related meningitis or ventriculitis is approximately 8%. It is unclear whether the duration of ventricular catheter has any relationship with the risk of infection. Patients often receive multiple antibiotics, leading to an increased risk of developing Clostridium difficile colitis, which needs prompt diagnosis and appropriate antimicrobial therapy.

Anti-Bacterial Agents↗

PubMed2006

Acute embolic stroke after electroconvulsive therapy.

This is the case report of a 44-year-old woman presented with an acute stroke immediately after electroconvulsive therapy (ECT). The patient had no significant medical history other than chronic depression. She was taking sertraline, and she had had multiple previous ECT treatments without any complications. While being monitored in the recovery room within 10 minutes after the last ECT session, she was found to have sudden onset of left-sided flaccid hemiplegia and numbness along with slurred speech. On arrival to our hospital, she was found to have flaccid hemiplegia on the left side involving the face, arm, and leg (face and arm more than the leg involvement), severe dysarthria, and mild neglect syndrome (National Health Institute Stroke Scale of 14). Noncontrast computed tomography (CT) of the head showed no signs of early ischemia, and iodine contrast CT angiography revealed right middle cerebral artery (MCA) (distal M1 segment) clot. Patient received intravenous recombinant tissue plasminogen (rt-PA) at 2.5 hours after the onset of symptoms, and then a total of 3.0 mg of intra-arterial (IA) rt-PA. Angiography at the end of the procedure showed successful recanalization of the M1 segment and normal vessel caliber with adequate distal flow. After the procedure, the patient made rapid improvements in all of her initial symptoms during the first 24 hours. An extensive stroke workup failed to reveal any cause of the stroke, including usual stroke and hypercoagulable risk factors. This was an acute embolic stroke immediately following an ECT, and without the aggressive thrombolytic therapy, the patient's outcome would have been poor because there was an M1 segment clot with a major MCA syndrome with relatively high National Institute of Health Stroke Scale. The neurological side effect profile of ECT is reported to be minimal with most common symptoms being headache, disorientation, and memory complaints. There is no clear cause-and-effect relationship in this case, and the stroke after ECT is extremely rare. In such rare event of stroke while receiving ECT, there is an effective treatment available using both intravenous and IA thrombolysis as reported in this case.

Acute Disease↗