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Biomedical subjects

Byung Kyu Park

Publications and source records attributed to Byung Kyu Park.

14 recordsLinked to original sources
PubMed2006

Bile acid analysis in biliary tract cancer.

The etiology of biliary tract cancer is obscure, but there are evidences that bile acid plays a role in carcinogenesis. To find the association between biliary tract cancer and bile acid, this study compared the bile acid concentration and composition among patients with biliary cancer, biliary tract stones, and no biliary disease. Bile was compared among patients with biliary tract cancer (n = 26), biliary tract stones (n = 29), and disease free controls (n = 9). Samples were obtained by percutaneous transhepatic biliary drainage, endoscopic nasobiliary drainage, or gallbladder puncture, and analyzed for cholic, deoxycholic, chenodeoxycholic, lithocholic, and ursodeoxycholic acid composition. Total bile acid concentration was lower in the cancer group than the biliary stone and control groups; the proportions of deoxycholic (2.2% vs. 10.2% and 23.6%, p < 0.001 and p < 0.001, respectively) and lithocholic acid (0.3% vs. 0.6% and 1.0%, p = 0.065 and p < 0.001, respectively) were also lower. This result was similar when disease site was limited to bile duct or gallbladder. Analysis of cases with bilirubin <or= 2.0 mg/dL also showed lower total bile acid concentration and deoxycholic acid composition in the cancer group compared to controls (5.7% vs. 23.6%, p = 0.003). Although the presence of bile duct obstruction explains some of the difference in total concentration and composition of bile acid, there are other contributing mechanisms. We suspect the alteration of bile acid transport might decrease bile acid excretion and cause the accumulation of carcinogenic bile acid in bile duct epithelium.

Adolescent↗
PubMed2006

The relationship of anatomic variation of pancreatic ductal system and pancreaticobiliary diseases.

The aims of this study were to identify the morphological diversities and anatomical variations of pancreatic ductal system and to define the relationships between pancreatic ductal systems, pancreaticobiliary diseases, and procedure- related complications, including post-ERCP pancreatitis. This study included 582 patients in whom both pancreatic duct (PD) and common bile duct were clearly visible by ERCP. PD systems were categorized into four types according to the relationship between common bile duct and PD. In types A and B, Wirsung duct formed the main PD. In type C, Wirsung duct did not form the main PD. If PD system did not fall into any of these three types, it was categorized as type D. The distribution of types among pancreatic ducts examined was as follows: type A: 491 cases (84.4%), type B: 56 cases (9.6%), type C: 20 cases (3.4%), and type D: 15 cases (2.6%). The anomalous anatomic variations of PD systems were divided into migration, fusion, and duplication anomalies. PD anomalies were noted in 51 patients, of which 19 (3.3%) were fusion anomalies (12 complete pancreas divisum, 7 incomplete pancreas divisum), and 32 (5.5%) were duplication anomalies (5 number variations, 27 form variations). No significant relationships between various PD morphologies and pancreaticobiliary diseases were found. However, post- ERCP hyperamylasemia was more frequently found in types C (41.7%), D (50%) and A (19.8%) than in type B (9.4%). In summary, whether Wirsung duct forms the main PD and the presence or absence of the opening of the Santorini duct are both important factors in determining the development of pancreatitis and hyperamylasemia after ERCP.

Bile Ducts↗
PubMed2006

Variability in conduction of the lateral femoral cutaneous nerve.

The purpose of this study was to establish a reliable technique for assessing conduction in the lateral femoral cutaneous nerve (LFCN), bearing in mind its anatomical variation. Based on our anatomical study, normative values were obtained in 40 healthy nerves. The optimal stimulation site was located 1 cm or more media 16470526 l to the anterior superior iliac spine (ASIS) in 93% of cases and over the ASIS in 7%. Sensory nerve action potentials (SNAPs) were recorded simultaneously along an imaginary line between the ASIS and the lateral border of the patella and 2 cm medial to this line. Side-to-side variability in amplitude was 31% for the recording from the line and 30% for the medial recording. The variability significantly decreased to 16% when the higher value of each side was compared. Therefore, the measurement of higher amplitude recorded at two different sites may minimize interside variability and improve the diagnostic utility of the LFCN conduction study.

Action Potentials↗
PubMed2006

Cervical paraspinal spontaneous activity in asymptomatic subjects.

Paraspinal fibrillation potentials or positive sharp waves (PSWs) reportedly may be the only electrodiagnostic abnormality in patients with radiculopathies. However, spontaneous activity may be present in muscles of asymptomatic subjects. To determine whether abnormal spontaneous activity in the cervical paraspinal muscles is clinically relevant, we evaluated the prevalence of such activity in asymptomatic individuals and examined its relationship with age. Sixty-six asymptomatic subjects underwent a needle electromyographic examination of the paraspinal muscles bilaterally at the C5/6 and C6/7 levels. All of the recorded potentials were captured and their firing rates and waveforms were evaluated. The potentials were considered to be abnormal if reproducible trains of PSWs or fibrillation potentials were present. Eight of the 66 (12%) subjects showed PSWs, five bilaterally; none showed fibrillation potentials. A statistical analysis for the effect of age could not be performed due to the small sample size. Because electromyographic cervical paraspinal abnormalities can be found in asymptomatic subjects, caution should be exercised when attributing the etiology of neck pain to radiculopathy if the only electrodiagnostic findings are electromyographic cervical paraspinal abnormalities.

Action Potentials↗
PubMed2006

The clinicopathologic significance of the expression of vascular endothelial growth factor-C in intrahepatic cholangiocarcinoma.

OBJECTIVES: Vascular endothelial growth factor-C (VEGF-C) is known to be an important lymphangiogenetic factor. Lymphatic spread is a key prognostic factor in intrahepatic cholangiocarcinoma (ICC). We studied the expression of VEGF-C in ICC tissues to clarify its clinicopathologic significance. METHODS: The expression of VEGF-C in surgical specimens obtained from 36 patients with ICC who underwent hepatic resection was examined by immunohistochemistry and Western blotting. Strong staining was defined as the presence of VEGF-C immunoreactivity in at least 50% of the tumor cells. Immunoreactivity in approximately 10% to approximately 50% of the tumor cells was considered as weak staining, and less than 10% as no staining. RESULTS: Of the 36 patients with ICC, 15 patients (41.7%) showed a strong positive result for VEGF-C. Eleven cases (30.6%) were negative and 10 cases (27.8%) showed weak immunoreactivity. VEGF-C expression was significantly correlated with lymph node metastasis (P = 0.032) and positive surgical margin (P = 0.03). Patients who had strong positive staining for VEGF-C showed significantly less favorable survival rates compared with patients who had negative or weak staining (P < 0.01). Other significant prognostic factors by univariate analysis were vascular invasion, lymph node involvement, and positive surgical margin. Multivariate analysis demonstrated that strong VEGF-C expression (P = 0.028) and vascular invasion (P = 0.021) were independent factors indicating poor prognosis. CONCLUSIONS: Our data suggest that VEGF-C expression serves as an independent and important prognostic factor in ICC patients, and it may play an important role in the lymph node metastasis of ICC.

Adult↗
PubMed2006

Intrathecal movement and tension of the lumbosacral roots induced by straight-leg raising.

OBJECTIVE: To obtain quantitative biomechanical data on the effects of different angles of straight-leg raising on intrathecal movements and tensions in the lumbosacral nerve roots in human cadavers. DESIGN: Eight embalmed human cadavers with no gross spinal pathology and no limitations in hip motion were used. We performed reverse straight-leg raising by hanging the left leg down from the table with the knee extended while measuring the movement and tension of nerve roots L2, L3, L4, L5, and S1 in 10-degree intervals for straight-leg raising from 0 to 70 degrees. RESULTS: The mean intrathecal movements at 70 degrees were 0.55 mm, 0.54 mm, 0.96 mm, 1.54 mm, and 2.31 mm for roots L2, L3, L4, L5, and S1, respectively. The movements were statistically significant at >50 degrees for root L5 and at >40 degrees for root S1 (P < 0.05). The tension in the nerve roots with increasing angle of straight-leg raising increased from roots L2 to S1. The mean tensions at 70 degrees of straight-leg raising were 141.25 g, 168.75 g, 228.75 g, 280.00 g, and 493.75 g for roots L2, L3, L4, L5, and S1, respectively. The difference in tension was significant at >70 degrees for roots L2, L3, and L4 roots, at >40 degrees for root L5 root, and at >10 degrees for root S1 (P < 0.05). CONCLUSIONS: The intrathecal movement and tension of the lumbosacral roots induced by straight-leg raising were <2.5 mm and <500 g, respectively. The movement and tension induced by straight-leg raising tended to be greater in more distal segmental roots.

Biomechanical Phenomena↗
PubMed2006

Phase II study of gemcitabine and cisplatin in advanced biliary tract cancer.

BACKGROUND: The aim of this phase II study was to determine the efficacy of gemcitabine plus cisplatin chemotherapy in patients with advanced biliary tract cancer. METHODS: Eligibility criteria included histologically confirmed adenocarcinoma with measurable tumor in the biliary tract that was unresectable and either locally advanced or metastatic. Patients received a combination of gemcitabine (1000 mg/m(2) intravenously [IV] on days 1, 8, and 15) and cisplatin (75 mg/m(2) IV on day 1). Cycles were repeated every 28 days. Objective tumor response rates and toxicities were evaluated according to World Health Organization criteria. RESULTS: Twenty-seven patients were enrolled in the study and a total of 120 cycles of chemotherapy were administrated. Objective partial response was observed in nine (33.3%) patients, while stable disease was found in seven (25.9%) patients. The median survival time was 10.0 months and the 1-year survival rate was 36%. Median time to disease progression was 5.6 months. The most common grade 3-4 toxicities were leukopenia (25.9%), anemia (29.6%), thrombocytopenia (22.2%), and vomiting (18.5%). Only one patient was hospitalized for chemotherapy-related complications. CONCLUSION: Gemcitabine and cisplatin combination chemotherapy is an effective, safe, and well-tolerated regimen for the treatment of advanced biliary tract cancer.

Adult↗
PubMed2004

Physiologic changes of compound muscle action potentials related to voluntary contraction and muscle length in carpal tunnel syndrome.

The affect of muscle length and voluntary contraction upon compound muscle action potentials (CMAPs) in subjects with carpal tunnel syndrome (CTS) has been evaluated. Twenty-five hands in a CTS patient group and 29 hands in a normal subject control group were studied. The CMAPs from the abductor pollicis brevis induced by median nerve stimulation at the wrist were obtained for five thumb positions: neutral, abduction for shortening with and without contraction, and adduction for lengthening with and without contraction. Upon muscle shortening with relaxation, CMAP duration decreased in both groups, whereas waveform amplitude increased in the control group and showed no significant change in the CTS group. Muscle shortening with contraction afforded decreased CMAP duration and increased CMAP amplitude in both groups. Upon muscle lengthening with relaxation, both groups showed a reduction in CMAP amplitude and an increase in CMAP duration. Upon lengthening with contraction, CMAP duration decreased in the control group; in contrast, the CTS group showed further amplitude reduction and the waveform duration returned to the neutral value. These results demonstrate that, in patients with CTS, physiologic CMAP summations by muscle shortening or contraction may be less effective, whereas decreases in amplitude and increases in duration may be accentuated by lengthening and contraction.

Action Potentials↗
PubMed2003

Role of oxygen free radicals in patients with acute pancreatitis.

AIM: The generation of oxygen free radicals has been implicated in the pathogenesis of experimental pancreatitis. The aim of this study was to determine the role of oxygen free radicals in patients with acute pancreatitis. METHODS: The plasma levels of C-reactive protein (CRP), lipid peroxide (LPO), myeloperoxidase (MPO) and superoxide dismutase (SOD) were measured in 13 patients with acute pancreatitis and 14 healthy volunteers. RESULTS: Among the patients with acute pancreatitis, there were higher plasma levels of LPO and MPO and lower SOD activity in patients with severe pancreatitis than in those with mild pancreatitis. However, there was no significant difference in the serum marker of oxidative stress no matter what the etiology was. The LPO level was especially correlated with the concentration of serum CRP and CT severity index. CONCLUSION: The oxygen free radicals may be closely associated with inflammatory process and the severity of acute pancreatitis. Especially, the concentration of plasma LPO is a meaningful index for determining the severity of the disease.

Acute Disease↗
PubMed2002

Delay in initiation and termination of muscle contraction, motor impairment, and physical disability in upper limb hemiparesis.

The purpose of this study was to describe the relationship between the delay in initiation and termination of muscle contraction and clinical measures of motor impairment and physical disability in the affected upper limb of patients with hemiparesis. Electromyographic (EMG) activity of 26 long-term survivors of stroke was recorded during isometric wrist flexion and extension. Upper limb motor impairment and disability were assessed with the Fugl-Meyer motor assessment (FMA) and arm motor ability test (AMAT), respectively. Delay in initiation and termination of muscle contraction was significantly prolonged in the paretic arm. However, the delay was not significantly affected by stroke type, stroke level, side of hemiparesis, or presence of aphasia. Delay in initiation and termination of muscle contraction correlated significantly with FMA and AMAT. Abnormally delayed initiation and termination of muscle contraction may contribute to hemiparetic upper limb motor impairment and physical disability in hemiparetic patients.

Adult↗
PubMed2002

Muscle weakness and cocontraction in upper limb hemiparesis: relationship to motor impairment and physical disability.

The purpose of this article is to describe the relationship between poststroke upper limb muscle weakness and cocontraction, and clinical measures of upper limb motor impairment and physical disability. Electrormyographic (EMG) activity of the paretic and nonparetic wrist flexors and extensors of 26 chronic stroke survivors were recorded during isometric wrist flexion and extension. The root mean square (RMS) of the EMG signal was used as a measure of strength of contraction. A ratio of RMS of antagonist and agonist muscles was used as a measure of cocontraction. Upper limb motor impairment and physical disability were assessed with the Fugl-Meyer motor assessment (FMA) and the arm motor ability test (AMAT), respectively. The strength of muscle contraction was significantly stronger in the nonparetic limb (P < 0.001). The degree of cocontraction was significantly greater in the paretic limb (P < 0.001). The strength of muscle contraction in the paretic limb correlated significantly with FMA (r = 0.62 to 0.87, P < or = 0.001) and AMAT (r = 0.66 to 0.80, P < or = 0.001) scores. Similarly, the degree of cocontraction correlated significantly with FMA (r = -0. 70 to -0.64, P < or = 0.001) and AMAT (r = -0. 72 to -0.62, P < or = 0.001) scores. Muscle weakness and degree of cocontraction correlate significantly with motor impairment and physical disability in upper limb hemiplegia. This relationship may provide insights toward development of specific interventions. However, additional studies are needed to demonstrate a cause and effect relationship.

Adult↗
PubMedDate not supplied

The extract of the flowers of Prunus persica, a new cosmetic ingredient, protects against solar ultraviolet-induced skin damage in vivo.

The flowers of Prunus persica Batsch have been used for skin disorders in East Asia from ancient times. In this investigation, the ethanol extract from this plant material was prepared and several major constituents were isolated. In addition, the protective effects of the extract were evaluated against solar ultraviolet (UV)-induced skin damage using in vivo animal models of UVB-induced erythema in guinea pigs and ear edema in ICR mice. From the extract, four kaempferol glycoside derivatives were successfully isolated and their contents were measured with HPLC. Among the derivatives isolated, the content of multiflorin B was highest (3.3%, w/w). The P. persica extract clearly inhibited UVB-induced erythema formation dose dependently when topically applied (IC(50) = 0.5 mg/cm(2)). It also inhibited UVB-induced ear edema (49% inhibition at 3.0 mg/ear). Moreover, multiflorin B inhibited UVB-induced erythema formation (80% inhibition at 0.3 mg/cm(2)), indicating that this compound is one of the active principles of the extract. All these results suggest that P. persica extract may be useful for protection against UVB-induced skin damage when topically applied.

Animals↗