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Biomedical subjects

C H Kao

Publications and source records attributed to C H Kao.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of the uptake and clearance of Tc-99m MIBI, Tl-201 and Ga-67 in drug-resistant lymphoma cell lines.

Tc-99m sestamibi (MIBI) has been used as a tumor-seeking agent. However, its role in detecting lymphomas has not been widely investigated. The aim of the present study was to determine the uptake and clearance characteristics of Tc-99m MIBI in vincristine-resistant lymphoma cell lines. In addition, thallium-201 (Tl-201) and gallium-67 (Ga-67) uptake and clearance characteristics were evaluated for comparison with Tc-99m MIBI. Drug-resistant lymphoma cell lines (monocyte-like, histiocytic lymphoma, human; B-lymphoma cell line, American Burkitt lymphoma, lymphoblastoid, human; Hodgkin's disease, lymphoid, human) were selected by multistep vincristine treatment up to 50 nM. After incubation of the radiotracers, Tc-99m MIBI, Tl-201 and Ga-67, in medium for 0, 10, 20, 30, 60 or 120 min, the uptake and clearance of each radiotracer were measured in the drug-resistant lymphoma cell lines. In addition, P-glycoprotein expression was determined by immunohistochemical study. In a comparison of the three radiotracers, the uptake of Tc-99m MIBI was the greatest in the studied wild-type lymphoma cell lines. Tc-99m MIBI uptake was much lower in drug-resistant tumor cell lines than in non-resistant cell lines. On the other hand, the uptake characteristics of Tl-201 did not differ between drug-resistant and non-resistant cells. Immunohistochemistry analyses of Ab-1 or JSB indicated that tumor cells expressed MDR-1 protein in all three cell lines. Tc-99m MIBI is a good radiotracer for detecting drug resistance in lymphoma cell lines.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Predicting chemotherapy response and comparing with P-glycoprotein expression using technetium-99m tetrofosmin scan in untreated malignant lymphomas.

The purposes of this study were to predict the chemotherapy response of untreated malignant lymphomas (ML) using a technetium-99m tetrofosmin (Tc-TF) scan and to compare Tc-TF results with P-glycoprotein (Pgp) expression. Before undergoing chemotherapy, 25 patients with ML were enrolled in this study. Tc-TF scan was performed 10 min after intravenous injection of Tc-TF. Immunohistochemical analyses were performed on multiple sections of ML specimens to evaluate Pgp expression. The chemotherapy response was evaluated in the first 1-2 years after the completion of treatment. The mean tumor-to-background ratio of the 15 patients with good responses (3.23+/-0.56) was significantly higher than that of the ten patients with poor responses (1.18+/-0.11). All of the 15 patients with good responses had positive Tc-TF scan results, but negative Pgp expression. Among the ten patients with poor responses, all had negative Tc-TF scan results, but six had positive Pgp expression and four had negative Pgp expression. Significant differences in the incidences of good and poor responses were found between patients with positive Tc-TF scan results and patients with negative Tc-TF scan results and between patients with positive Pgp expression and patients with negative Pgp expression. No significant differences in the incidences of good and poor responses were found between Hodgkin's disease patients and non-Hodgkin's lymphoma patients, stage I-II patients and III-IV patients, patients aged >40 and patients aged < or =40 years, and patients with and without B symptoms. Compared with other prognostic factors, Tc-TF scan results and Pgp expression more accurately predict the chemotherapy response in patients with ML.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

To predict chemotherapy response using technetium-99m tetrofosmin and compare with p-glycoprotein and multidrug resistance related protein-1 expression in patients with untreated small cell lung cancer.

The aim of this study was to investigate the relationships among technetium-99m tetrofosmin (Tc-TF) accumulation in untreated small cell lung cancer (SCLC), the expression of P-glycoprotein (Pgp) and multidrug resistance related protein-1 (MRP1), and the response to chemotherapy in patients with untreated SCLC. Thirty patients with SCLC were studied with chest scintigraphy 15 to 30 min after intravenous injection of Tc-TF before chemotherapeutic induction. Tc-TF chest scans were interpreted both visually and quantitatively. The response to chemotherapy was evaluated upon completion of chemotherapy. Immunohistochemical analyses were performed on multiple non-consecutive sections of biopsy specimens to detect Pgp and MRP1 expression. Fifteen patients with good response to chemotherapy had a significantly higher incidence (100.0%) of positive Tc-TF chest single photon emission computed tomography (SPECT) findings and negative Pgp or MPR expression than 15 patients with poor response (20%) (P<0.05). The tumor/background (T/B) ratios were 1.8+/-0.3 and 1.2+/-0.3 for patients with good response and poor response, respectively (P<0.05). However, other prognostic factors (performance status, tumor size and stage) were not significantly related to Tc-TF chest scan findings and response to chemotherapy. Tc-TF chest scintigraphy correlated well with Pgp or MRP1 expression and accurately predicted the response to chemotherapy in patients with SCLC.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Changes in the levels of nitric oxide synthase and protein kinase C gamma following kainic acid receptor activation in the rat spinal cord.

In this study, we evaluated the levels of nitric oxide synthase, both neuronal and induced (nNOS and iNOS, respectively), cyclooxygenase-1 and 2 (COX-1 and COX-2) and protein kinase C gamma (PKCgamma) and correlated these with algogenic behavior following spinal kainic acid (KA) receptor activation in rats. Thirty adult male Sprague-Dawley rats were randomly assigned into six groups (n=5). Groups A, B, and C received 0.5 g kainic acid intrathecally and were analyzed at 3, 6, 24 h after injection, respectively. Groups D, E, and F received saline and were analyzed at 3, 6, 24 h after injection, respectively. We observed for behavioral changes in the rats following intrathecal KA injection and analyzed the protein levels of NOS, COX and PKCgamma by Western blotting techniques. Importantly, we clarified the potential roles of PKCgamma in the regulation of nNOS and COX-2 following intrathecal injection with KA in the rat spinal cord. COX-2 protein was detected but not significantly changed in the lumbosacral spinal cord at 3, 6, and 24 h following intrathecal KA injection (P>0.05). In contrast, nNOS protein was detected at higher levels in comparison with normal spinal cord at 6 and 24 h after intrathecal administration of KA (P<0.05). PKCgamma also increased significantly at 3, 6, and 24 h after intrathecal KA injection when compared with the baseline level (P<0.05). On the other hand, COX-1 and iNOS were not detected in either normal or KA treated spinal cords. These results provide strong in vivo evidence to support the idea that nNOS but not COX-2, plays an important role in spinal KA receptor activation. Furthermore, up-regulation of PKCgamma is involved in KA induced algogenic behavior in rats.

Animals↗
PubMed2001

Evaluation of chemotherapy response using technetium-99M-sestamibi scintigraphy in untreated adult malignant lymphomas and comparison with other prognosis factors: a preliminary report.

The purpose of this study was to predict chemotherapy response using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scintigraphy in untreated adult malignant lymphomas (ML) and compare the response with other prognosis factors. Before chemotherapy, 25 adult patients with ML were enrolled in this study. Tc-MIBI scintigraphy was performed 10 min after intravenous injection of Tc-MIBI to calculate tumor-to-background (T/B) uptake ratio and interpret the results visually. Chemotherapy response was evaluated in the first 1 to 2 years after completion of treatment by clinical and radiological methods. The mean T/B uptake ratio of the 15 patients with good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with poor response (1.2 +/- 0.1). All of the 15 patients with good response had positive Tc-MIBI scintigraphic results. All of the 10 patients with poor response had negative Tc-MIBI scintigraphic results. However, there were no significant differences in the incidences of good and poor responses for other prognosis factors. In our preliminary study, when compared with other prognosis factors, Tc-MIBI scintigraphy was the best tool to predict chemotherapy response in adult patients with ML.

Adult↗
PubMed2001

Comparing 18-fluoro-2-deoxyglucose positron emission tomography with a combination of technetium 99m tetrofosmin single photon emission computed tomography and computed tomography to detect recurrent or persistent nasopharyngeal carcinomas after radiotherapy.

BACKGROUND: The diagnostic accuracy of combined computed tomography (CT) and technetium 99m tetrofosmin (Tc-TF) single photon emission computed tomography (SPECT) of head and neck to differentiate recurrent or residual nasopharyngeal carcinomas (NPCs) from benign lesions after radiotherapy was evaluated and compared with positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG). METHODS: Four months after radiotherapy, 36 patients with NPC underwent Tc-TF SPECT and CT of head and neck to differentiate recurrent or residual NPC from benign lesions. Histopathologic examinations were performed on nasopharyngeal biopsies of all 36 patients. RESULTS: Based on the biopsy results, the sensitivity, specificity, and accuracy of Tc-TF SPECT were 64%, 96%, and 86%, respectively, for differentiation of recurrent or persistent NPC from benign lesions. For CT and FDG-PET, the sensitivity, specificity, and accuracy were 73%, 88%, and 83% and 100%, 96%, 97%, respectively. For the 27 patients with NPC whose Tc-TF SPECT and CT results were congruent, the combination of Tc-TF SPECT and CT had the same sensitivity, specificity, and accuracy (100%, 96%, and 96%) as FDG-PET. For the nine patients with NPC with incongruent Tc-TF SPECT and CT results, FDG-PET correctly differentiated two benign lesions from seven recurrent/residual NPCs. CONCLUSIONS: Although, FDG-PET is the best tool for detecting recurrent or residual NPC, combined congruent Tc-TF SPECT and CT results achieved the same accuracy as FDG-PET. Therefore, we concluded that FDG-PET could be considered only when Tc-TF SPECT and CT give incongruent results.

Adolescent↗
PubMed2001

P-Glycoprotein and multidrug resistance-related protein expressions in relation to technetium-99m methoxyisobutylisonitrile scintimammography findings.

The purpose of this study was to retrospectively study 48 patients with infiltrating ductal breast cancer to evaluate the relationship between the degree of accumulation of technetium-99m methoxyisobutylisonitrile (Tc-MIBI) and P-glycoprotein (Pgp) or multidrug resistance-related protein (MRP) expression in breast cancer tissues. Before surgery or biopsy, all 48 patients underwent scintimammography started 10 min after the injection of Tc-MIBI. Tumor:background (T:B) ratios were calculated from the Tc-MIBI scintimammography. Immunohistochemical analysis was performed on the pathological specimens of the 48 breast tumors to determine Pgp and MRP expression. According to the results of immunohistochemical analysis, the 48 breast cancers were separated into four groups: (a) group 1, 12 cancers with both positive Pgp expression and positive MRP expression; (b) group 2, 12 cancers with positive Pgp expression and negative MRP expression; (c) group 3, 12 cancers with negative Pgp expression and positive MRP expression; and (d) group 4, 12 cancers with both negative Pgp expression and negative MRP expression. Among the four groups, the T:B ratio was lowest in group 1 (1.13+/-0.10) and highest in group 4 (2.17+/-0.14), respectively (P < 0.05). The T:B ratios of groups 2 (1.30+/-0.25) and 3 (1.32+/-0.26) were between those of groups 1 and 4. Our data confirmed that Tc-MIBI scintimammography is useful for determining Pgp and MRP expression in patients with breast cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Technetium-99m tetrofosmin chest imaging related to p-glycoprotein expression for predicting the response with paclitaxel-based chemotherapy for non-small cell lung cancer.

Our aim was to use technetium-99m tetrofosmin (Tc-TF) uptake in non-small cell lung cancer (NSCLC) for predicting the chemotherapeutic response of NSCLC to paclitaxel and to compare the results with the expression of multidrug resistance (MDR) - P-glycoprotein (Pgp). Twenty patients with advanced NSCLC were enrolled in this study before chemotherapy with paclitaxel. Tc-TF chest imaging was performed to calculate early and delayed tumor-to-normal lung (T/NL) count-density ratios, as well as washout indexes (WIs). Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to detect Pgp expression. The response to chemotherapy was evaluated by clinical and radiological methods in the third month after completion of treatment. The early and delayed T/NL count-density ratios of patients with good response were significantly higher than those of patients with poor response (p <0.05). However, no significant difference in WI between the two groups of patients was found (p > 0.05). A significantly higher incidence of good response was found in patients with negative Pgp expression (100%) than in patients with positive Pgp expression (40%) (p <0.05). Significantly higher early and delayed T/NL count-density ratios as well as decreased WIs were found in patients with negative Pgp expression than in patients with positive Pgp expression. However, other prognostic factors (age, sex, body weight loss, performance status, tumor stage, and tumor cell type) were not significantly different between the patients with good response and those with poor response. Because Tc-TF chest images can correctly represent the expression of Pgp in NSCLC, it can accurately predict the chemotherapeutic response to paclitaxel.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Structural correlation of catecholase-like activities of oxy-bridged dinuclear copper(II) complexes.

Eight oxy-bridged dinuclear copper(II) complexes with catecholase-like sites, [Cu(L1)X]2 (HL1 = 1-diethylaminopropan-2-ol, X=N3- 1, NCO- 2, and NO2- 3), [Cu(L2)X]2 (HL2=N-ethylsalicylaldimine, X=NO3- 4, Cl- 5, N3- 6, NCS- 7), and [Cu(L3)]2(ClO4)2, 8 (HL3=N-(salicylidene)-N'-(2-pyridylaldene)propanediamine) have been prepared and characterized. The single crystal X-ray analysis show that the structures of complexes 6 and 8 are dimeric with two adjacent copper(II) atoms bridged by pairs of micro-oxy atoms from the L2 and L3 ligands. Magnetic susceptibility measurements in the temperature range 4-300 K indicate significant antiferromagnetic coupling for 4, 5 and 7 and ferromagnetic coupling for 6 between the copper(II) atoms. The catecholase activity of complexes for the oxidation of 3,5-di-tert-butylcatechol by O2 was studied and it was found that the complexes with the bond distance of Cu(II)...Cu(II) located at 2.9-3.0 A show higher catecholase activity.

Catalytic Domain↗
PubMed2001

The higher likelihood of developing cardiomegaly during follow-up in patients with syndrome X and abnormal thallium-201 myocardial perfusion SPECT.

'Syndrome X' describes patients with exertional chest pain and a normal coronary arteriogram. In some patients, acute myocardial ischemia can be demonstrated by regional myocardial perfusion defects on thallium-201 exercise test. However, some patients with typical angina have normal perfusion on thallium-201 heart scintigraphy. It is not clear whether there are different prognoses for patients with normal and abnormal thallium studies. In this study, the clinical features, long term follow-up and clinical results of syndrome X patients with normal and abnormal thallium studies were evaluated to determine the differences between these two groups. Fifty-nine patients (52 males, seven females, mean age 62+/-6 years) with syndrome X were enrolled and divided into two groups on the basis of results of thallium-201 heart scintigraphy. Group I was comprised of 22 patients with normal thallium-201 perfusion scan and group II was comprised of 37 patients with abnormal thallium-201 heart scan. All subjects received coronary arteriography, exercise test, thallium-201 myocardial SPECT, ejection fraction of left ventricle, echocardiography, blood analysis and long term follow-up with questionnaire for 10 years. Lower maximal rate-pressure product and higher angina scores were found in group II. More patients developed cardiomegaly (nine of 33 patients) in group II than in group I (one of 21 patients). Both groups, however, were at low risk for cardiac events (cardiac death or myocardial infarction).

Aged↗
PubMed2001

Technetium-99m-sestamethoxyisobutylisonitrile scan as a predictor of chemotherapy response in malignant lymphomas compared with P-glycoprotein expression, multidrug resistance-related protein expression and other prognosis factors.

The purpose of the present study was to predict the response of malignant lymphomas (MLs) to chemotherapy using technetium-99m methoxyisobutylisonitrile (Tc-MIBI) scan and to compare it with the predictive ability of P-glycoprotein (P-gp) expression, multidrug resistance-related protein (MRP) expression and other prognosis factors. Twenty-five ML patients were enrolled in this study prior to initiation of chemotherapy. Images were obtained 10 min after intravenous injection of Tc-MIBI, interpreted visually and the tumour-to-background (T/B) ratios calculated. Immunohistochemical analyses were performed on sections of the biopsy specimens to determine P-gp and MRP expression. Chemotherapy response was evaluated in the first 1-2 years after completion of chemotherapy. The mean T/B ratio of the 15 patients with a good response (3.3 +/- 0.6) was significantly higher than that of the 10 patients with a poor response (1.2 +/- 0.1). All 15 patients with a good chemotherapy response had positive Tc-MIBI scan results and negative P-gp and MRP expression. All 10 patients with a poor response had negative Tc-MIBI scan results and either positive P-gp or MRP expression. Other prognosis factors showed no significant difference in the incidence of good and poor responses. Tc-MIBI scan results represent P-gp or MRP expression more accurately than other prognosis factors and predict the chemotherapy response in ML patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Small intestinal bacterial overgrowth versus antimicrobial capacity in patients with spontaneous bacterial peritonitis.

BACKGROUND: Spontaneous bacterial peritonitis (SBP) is a serious infection in cirrhotic patients with ascites. Both defects in the host defense mechanisms and the enhancement of the offensive factor (small intestinal bacterial overgrowth (SIBO)) may contribute to the development of SBP. Therefore, the aim of this study was to evaluate the role of SIBO versus various antimicrobial capacities in the pathogenesis of SBP in cirrhotic patients. METHODS: Forty-five cirrhotic patients were enrolled in this study. Bacterial overgrowth was evaluated by breath hydrogen test (BH2T). The hepatic reticuloendothelial system phagocytic index (HRESPI) was measured by intravenously injected colloid suspensions. RESULTS: The Child-Pugh scores in the SBP group were higher than in the non-SBP group (10.5 +/- 2.0 versus 8.0 +/- 1.8, P < 0.01). The ascitic protein concentration was significantly lower in the SBP group than in the non-SBP group (897 +/- 425 mg/l versus 1,325 +/- 453 mg/l, P < 0.01). Furthermore, the serum C3 concentration was lower in the SBP group than in the non-SBP group (43.1 +/- 13.6 ng/dl versus 73.2 +/- 26.4 ng/dl, P < 0.01). The serum C4 concentration was also lower in the SBP group than in the non-SBP group (12.4 +/- 4.0 ng/dl versus 16.9 +/- 6.6 ng/dl, P < 0.05). The incidence of SIBO was higher in the SBP group than in the non-SBP group (68.2% versus 17.4%, P < 0.01). HRESPI values were significantly higher in the two groups of cirrhotic patients than in the normal reference. However, there were no statistical differences in HRESPI between the two groups (8.4 +/- 2.8 min in the SBP group versus 7.9 +/- 2.8 min in the non-SBP group). CONCLUSIONS: The results of this study showed that the hepatic reticuloendothelial function is impaired in cirrhotic patients, but the degree of impairment does not differ between patients with and without previous history of SBP. Lower ascitic total protein, lower serum C3 and C4 concentrations, and presence of SIBO are all risk factors for SBP. Based on the results of our study, defects in the host defense mechanisms and the enhancement of the offensive factor (SIBO) may act in concert for the development of SBP.

Ascitic Fluid↗
PubMed2001

Evaluation of hepatobiliary function by hepatobiliary scintigraphy in hepatoma patients after transcatheter arterial embolization.

BACKGROUND: Transcatheter arterial embolization (TAE) is the treatment of choice for inoperable hepatocellular carcinoma. However, altered and impaired gallbladder function due to gallbladder infarction and bile duct necrosis following TAE have been reported. METHODS: Hepatobiliary function was evaluated using quantitative Tc-99m DISIDA hepatobiliary scintigraphy in 40 hepatoma patients before and after TAE. The patients were separated into two groups: group 1 (20 patients), who received pre-cystic artery TAE, and group 2 (also 20 patients), who received post-cystic artery TAE. RESULTS: After TAE, there were no significant changes in liver or bile duct function in the patients of either group. However, for group I patients, significantly decreased gallbladder function was found after TAE. CONCLUSIONS: Altered and impaired gallbladder function is common in hepatoma patients who receive pre-cystic artery TAE, and Tc-99m DISIDA cholescintigraphy may be useful for evaluating hepatobiliary function in hepatoma patients who receive TAE.

Aged↗
PubMed2001

Differentiation of radiographically indeterminate solitary pulmonary nodules with.

BACKGROUND: The purpose of this preliminary study was to evaluate the efficacy of positron emission tomography (PET) with [18F]fluoro-2-deoxyglucose (FDG) for differentiating benign from malignant solitary pulmonary nodules. METHODS: Twenty-six patients (12 females, 14 males, age 27-79 years) with radiographically indeterminate solitary pulmonary nodules underwent FDG-PET and the findings were compared with the results of pathological examination of biopsy samples. FDG activity in the lesion was expressed as the ratio of lesion-to-background counts (L/B ratio) for semiquantitative analysis. RESULTS: The mean L/B ratio of malignant lesions (8.81+/-3.71, n = 20) was not significantly higher than that of benign lesions (4.71+/-3.00, n = 6) (p = 1.00). Using a cut-off L/B ratio of 5.0 for malignancy, FDG-PET correctly detected 19 true positive and three true negative cases, but failed to detect three false positive (two abscesses and one cryptococcus) cases and one false negative (adenocarcinoma) case. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 95, 50, 86, 75 and 85%, respectively. CONCLUSIONS: FDG-PET is a sensitive modality for detecting malignancy, but is not specific enough. Benign lung lesion with active inflammation could demonstrate high FDG uptake, making it difficult to differentiate from malignancy. In the future, we will increase the case numbers to evaluate further the utility of FDG-PET for differentiating radiographically indeterminate solitary pulmonary nodules.

Adult↗