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Biomedical subjects

S T Ho

Publications and source records attributed to S T Ho.

At least 19 recordsLinked to original sources
PubMed2004

Antinociceptive effect of a novel long-acting nalbuphine preparation.

BACKGROUND: A long-acting analgesic may be particularly desirable in patients suffering from long-lasting pain. The aim of the study was to evaluate the antinociceptive effect of a novel nalbuphine preparation and to determine its duration of action. METHODS: The antinociceptive effects of i.m. nalbuphine HCl in saline and nalbuphine base in sesame oil were evaluated in rats. The in vitro drug-releasing profiles of nalbuphine HCl and base in different preparations were also evaluated. RESULTS: We found that i.m. nalbuphine HCl 25, 50 and 100 micromol kg(-1) produced dose-related antinociceptive effects with a duration of action of 1.5, 2 and 3 h, respectively. i.m. nalbuphine base 100, 200 and 400 micromol kg(-1) also produced dose-related antinociceptive effects but with longer durations of action: 27, 49 and 55 h, respectively. In vitro studies demonstrated that nalbuphine base in sesame oil had the slowest drug-releasing profile of the different preparations. CONCLUSIONS: i.m. injection of an oil formulation of nalbuphine base produced a long-lasting antinociceptive effect.

Analgesics, Opioid↗
PubMed2004

Pharmacokinetics of desflurane uptake into the brain and body.

The aim of this study was to investigate the pharmacokinetics of desflurane uptake into the brain and body by comparing desflurane concentrations in internal jugular-bulb blood (Jdes), arterial blood (Ades) and pulmonary arterial blood (PAdes) at a fixed inspired desflurane concentration. Thirteen patients (aged 42-72 years) undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 5% inspired desflurane concentration (CIdes) during the first hour of anaesthesia. Under constant volume-controlled ventilation, CIdes and end-tidal desflurane (CEdes) were measured with an infrared analyser. The desflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti-Q pulmonary artery catheter. It took 24 min for the Jdes to equilibrate with Ades. Both CIdes-CEdes and Ades-PAdes gradients persisted during the study period. There was no further uptake of desflurane into the brain after 24 min but there was near-constant uptake into the body.

Adult↗
PubMed2003

High prevalence of asymptomatically poor muscle perfusion of lower extremities measured in systemic lupus erythematosus patients with abnormal myocardial perfusion.

Patients with systemic lupus erythematosus (SLE) may develop premature atherosclerosis, notably peripheral vascular disease (PVD) presenting with intermittent claudication or gangrene. Therefore, it is important to investigate if high prevalence of poor muscle perfusion of lower extremities in SLE patients with abnormal myocardial perfusion is related to more cardiovascular risk factors. We used a well-established and noninvasive radionuclide method (xenon 133 muscle washout) to evaluate objectively the anterior tibial muscle perfusion of 34 SLE female patients without symptoms/signs of PVD in the lower extremities. The patients were separated into two groups according to myocardial perfusion imaging results. Meanwhile, 30 normal female controls with matched age distribution were also included for comparison. The muscle perfusion differed significantly ( P <0.05) between patients (1.90+/-0.41 ml/100 g per min) and controls (2.91+/-0.50 ml/100 g per min), as well as between 18 SLE patients with abnormal myocardial perfusion (1.33+/-0.43 ml/100 g per min) and 16 with normal myocardial perfusion (2.26+/-0.45 ml/100 g per min). Based on the xenon 133 muscle washout method, we conclude that muscle perfusion in the lower extremities of SLE patients without symptoms/signs of PVD is significantly decreased and related to abnormal myocardial perfusion.

Adult↗
PubMed2003

Usefulness of Tc-99m ECD brain SPECT to evaluate the effects of methylprednisolone pulse therapy in lupus erythematosus with brain involvement: a preliminary report.

Methylprednisolone pulse therapy (MPT) was introduced to avoid life-threatening complications in systemic lupus erythematosus (SLE) with brain manifestations. However, its efficacy in SLE patients remains uncertain and needs to be objectively evaluated. In this study, technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect regional cerebral blood flow (rCBF) in SLE patients with normal brain magnetic resonance imaging (MRI) findings. Twelve female SLE patients with neuropsychiatric symptoms were enrolled in this study. All patients had normal brain MRI and abnormal Tc-99m ECD brain SPECT findings. The Tc-99m ECD brain SPECT studies were performed 2 weeks after MPT. Pre- and post-MPT serum levels of anticardiolipin antibodies (ACA) and antiribosomal P antibodies (anti-P) were also measured. Before MPT, four patients had positive ACA and seven had positive anti-P. After MPT, all 12 patients demonstrated negative serologic findings and no neuropsychiatric symptoms. After MPT, ten patients showed complete recovery and two showed partial recovery of rCBF in the follow-up Tc-99m ECD brain SPECT images. This imaging is a logical and objective tool for measuring the effects of MPT in SLE patients with brain involvement by the determination of rCBF changes.

Adult↗
PubMed2003

Comparing the relationship of Taxol-based chemotherapy response with P-glycoprotein and lung resistance-related protein expression in non-small cell lung cancer.

Our aim was to compare Taxol-based chemotherapy response of non-small cell lung cancer (NSCLC) with P-glycoprotein (Pgp) or lung resistance protein expression (LRP). Immunohistochemical analyses were performed on multiple nonconsecutive sections of the biopsy specimens to detect Pgp and LPR expressions in 40 patients with advanced NSCLC before Taxol-based chemotherapy. The chemotherapy response was evaluated by clinical and radiological methods in the third month after completion of treatment. No significant differences of prognostic factors (age, sex, body weight loss, performance status, tumor size, tumor stage, and tumor cell type) were found between the 20 patients with good and the 20 patients with poor responses. The incidence difference of positive Pgp expressions between good and poor responses was significant, however, the difference of LRP expression was not. We concluded that Taxol-based chemotherapy response of patients with NSCLC was related to Pgp but not LPR expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

Pharmacokinetics of sevoflurane uptake into the brain and body.

The aim of this study was to investigate the pharmacokinetics of sevoflurane uptake into the brain and body by comparing sevoflurane concentrations in internal jugular-bulb blood (Jsev), arterial blood (Asev) and pulmonary arterial blood (PAsev) over a fixed inspired sevoflurane concentration. Ten patients (aged 51-73 years), undergoing coronary artery bypass grafting surgery were enrolled in this study. They were anaesthetised using a constant 3.5% inspired sevoflurane concentration (CIsev) during the first hour of anaesthesia. During constant volume-controlled ventilation, we measured CIsev and end-tidal sevoflurane (CEsev) using infrared analysis. The sevoflurane concentration in the blood was analysed using gas chromatography, and cardiac output was measured using an Opti-Q pulmonary artery catheter. We found that it took 40 min for the brain concentration to equilibrate with arterial blood (Asev). Both CIsev-CEsev and Asev-PAsev gradients persisted during the study period. There was no further uptake of sevoflurane into the brain after 40 min; however, there was near-constant uptake into the body.

Aged↗
PubMed2003

Evaluating the changes in alveolar permeability and lung ventilation in patients with chronic renal failure after haemodialysis using 99mTc-DTPA radioaerosol inhalation lung scan.

Hypoxaemia occurring in patients with chronic renal failure (CRF) during haemodialysis (HD) has long been known. Several mechanisms of pathogenesis have been proposed. Before and after regular HD, lung ventilation (LV) and alveolar permeability (AP) were measured in 24 male patients with CRF (age, 61-75 years). LV and AP were determined by 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA) radioaerosol inhalation lung scan (99mTc-DTPA lung scan). The LV images were visually interpreted according to established criteria, including the presence or absence of an inhomogeneous distribution, inverted base to apex gradient and segmental hypoventilation. The degree of AP in the total right lung was presented as the clearance rate (K; %.min-1) of the time-activity curve from dynamic total right lung images. Ten male normal controls (age, 62-76 years) were enrolled in the study for comparison. Ten of 24 (42%) cases showed an inhomogeneous distribution and eight of 24 (33%) cases showed hypoventilation on equilibrium LV images. After regular HD for 5 h, no significant changes in the LV images were found. Before HD, the CRF patient group (K=1.14+/-0.36%.min-1) had a significantly faster clearance rate than that of normal controls (0.75+/-0.14%.min-1, P<0.05). Moreover, the clearance rate after HD was significantly slower (0.87+/-0.15%.min-1, P<0.05) than that before HD. CRF can predispose patients to LV change and AP damage. After HD, the damage to AP is significantly improved. However, after HD, the change in LV is not significant.

Administration, Inhalation↗
PubMed2003

Correlations of extractable heavy metals with organic matters in contaminated river sediments.

In southern Taiwan, almost all the main rivers have been contaminated by anthropogenic heavy metals and organic matters. The main pollution sources include agricultural, industrial, and domestic activities. River sediments potentially have large capacities to accumulate heavy metals and organic matters when the river water flows through it. The sediments sampled from high contaminated river (the Yenshui River) and moderately contaminated rivers (the Tsengwen, Chishui, Potzu, and Peikang Rivers) were used to realize correlations between each kind of aqua regia extractable heavy metals (Co, Cr, Cu, Zn, Ni, Pb, Mn, and Fe) and organic matters in vertical sediment cores. Organic matters and aqua regia extractable heavy metal concentrations, analyzed by strong acid-digested extraction, were determined in vertical profile segments from downstream sediments of the five rivers. Sum of six aqua regia extractable heavy metals (Co, Cr, Cu, Zn, Ni, and Pb) were below 3,000 mg/kg in sediments of the Yenshui River, and below 500 mg/kg in the other four rivers' sediments. Strongly positive correlations (r = 0.83-0.95) between each kind of aqua regia extractable heavy metals and organic matters (concentration range between 0.6 to 3.8%) were observed in sediments of the Yenshui River. The slopes of the linear regressive lines approximated the average metal complexation ratios with organic matters in the sediments. In sediments of the other four rivers, smaller positive correlation coefficients between aqua regia extractable heavy metals and organic matters (below 2.6%) were observed. The complexation ratios derived from the four moderately polluted river sediments were smaller than those derived from the highly contaminated river sediments, indicating that the importance of organic matters in the accumulation of heavy metals in river sediments.

Environmental Monitoring↗
PubMed2002

Detecting parathyroid adenoma using technetium-99m tetrofosmin: comparison with P-glycoprotein and multidrug resistance related protein expression--a preliminary report.

The aim of this study was to investigate the relationships among technetium-99m tetrofosmin (Tc-TF) accumulation in parathyroid adenoma and the expression of P-glycoprotein (Pgp) or multidrug resistance related protein (MRP). Before operation, 33 patients with parathyroid adenomas (larger than 1.5 gm) were studied with parathyroid scintigraphy 10 minutes and 2 hours after intravenous injection of Tc-TF before operation. Immunohistochemical analyses (IHA) were performed on multiple nonconsecutive sections of operative parathyroid specimens to detect Pgp or MRP expression. According to the results of IHA, the 33 parathyroid adenomas were separated into four groups: (1) 2 adenomas with both positive Pgp and positive MRP expression, (2) 1 adenomas with positive Pgp but negative MRP expression, (3) 2 adenomas with negative Pgp but positive MRP expression, and (4) 28 adenomas with both negative Pgp and negative MRP expression. All of 28 adenomas in the group 4 could be detected by Tc-TF parathyroid imaging. All of 5 adenomas in the groups 1 to 3 could not be detected by TcTF parathyroid imaging (p < 0.05). Not only the size of parathyroid adenomas, but also significant Pgp or MRP expression limited the sensitivity of Tc-TF parathyroid imaging to localize parathyroid adenomas before operation.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2002

Abnormal regional cerebral blood flow in primary antiphospholipid antibody syndrome patients with normal magnetic resonance imaging findings. A preliminary report.

UNLABELLED: Technetium-99m ethyl cysteinate dimer (Tc-99m ECD) brain single photon emission computed tomography (SPECT) was used to detect abnormal regional cerebral blood flow (rCBF) in primary antiphospholipid antibody syndrome (PAPS) patients. The patients had mild neuropsychiatric manifestations and normal brain magnetic resonance imaging (MRI) findings in this preliminary study. Fifteen such female PAPS patients were examined with Tc-99m ECD brain SPECT in order to evaluate the rCBF. In addition, serum anti-cardiolipin antibodies (ACA) and lupus anticoagulant (LA) were simultaneously measured for comparison. RESULTS: (a) Tc-99m ECD brain SPECT revealed hypoperfusion brain lesions in 12 (80%) of the PAPS patients. Pariental lobes were the most commonly involved areas. (b) 11 (73%) and 9 (60%) cases had positive ACA and positive LA, respectively. In addition, ACA and LA results were correlated to the Tc-99m ECD brain SPECT findings. Tc-99m ECD brain SPECT is a sensitive tool for detecting abnormal rCBF in PAPS patients with mild neuropsychiatric manifestations and normal brain MRI findings.

Adult↗
PubMed2002

The influences of blood glucose and duration of fasting on myocardial glucose uptake of [18F]fluoro-2-deoxy-D-glucose.

During the study of chest using positron emission tomography (PET) with [18F]fluoro-2-deoxy-d-glucose (FDG), a significant myocardial FDG uptake can prevent detection of the lesion that is located either behind or closely attached to the heart border. Two well-known and possible factors of myocardial FDG uptake are blood glucose level and fasting duration before FDG PET scanning. This study investigates whether the two factors are related to myocardial FDG uptake. Our study also explores the possibility of eliminating myocardial FDG uptake by controlling patients' blood glucose level and/or fasting duration. Whole-body FDG PET scans performed on 270 consecutive patients performed were reviewed. The study subjects were classified into four grades of myocardial FDG uptake according to the visual interpretation of the FDG PET image hard-copy films. For all study subjects, the blood sugar level and fasting duration before FDG injection were recorded. Then, the blood sugar levels and fasting duration were compared to the visual grade of myocardial FDG uptake for each study subject. About half of the study subjects showed graded 0 myocardial FDG uptake when the blood glucose levels were < or = 120 mg x dl(-1) or when the fasting duration was between 5 and 12 h. One hundred and thirty-one of the 142 (92%) patients with graded 0 uptake were asked to fast for > or = 4 h and had blood glucose levels < or = 120 mg x dl(-1). Based on our findings, we conclude that controlling the patients' blood glucose levels to < or = 120 mg x dl(-1) and at least 5 h fasting should be recommended to decrease myocardial FDG uptake.

Adolescent↗
PubMed2002

Abnormal regional cerebral blood flow on 99mTc ECD brain SPECT in patients with primary Sjögren's syndrome and normal findings on brain magnetic resonance imaging.

OBJECTIVE: Technetium-99m ethyl cysteinate dimer (99mTc ECD) single photon emission computed tomography (SPECT) of the brain was used to detect abnormal regional cerebral blood flow (rCBF) in patients with primary Sjögren's syndrome (pSS) and normal findings on brain magnetic resonance imaging (MRI). METHODS: (99m)Tc ECD brain SPECT was performed to detect brain lesions showing hypoperfusion in 32 female patients with pSS and definite neuropsychiatric symptoms or signs. Seventeen female patients with pSS without neuropsychiatric symptoms and signs were included as a control group for comparison. All of the 49 patients with pSS had normal findings on brain MRI. RESULTS: 99mTc ECD brain SPECT showed brain regions with hypoperfusion in 18 (56.3%) of the 32 patients, and parietal lobes were the most common areas with such lesions. By contrast, 99mTc ECD brain SPECT showed brain regions with hypoperfusion in only three (17.6%) of the 17 patients with pSS without neuropsychiatric symptoms or signs. CONCLUSION: This study suggests that 99mTc ECD SPECT is a sensitive tool for detecting regions of hypoperfusion in the brains of patients with pSS and neuropsychiatric symptoms or signs and normal findings on brain MRI. However, a review of the literature showed that the (99m)Tc ECD SPECT findings in patients with pSS were non-specific.

Adult↗
PubMed2002

Detection of cervical lymph node metastases in nasopharyngeal carcinomas: comparison between technetium-99m methoxyisobutylisonitrile single photon emission computed tomography and magnetic resonance imaging.

We compared the effectiveness technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) of head and neck in evaluating cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC). Forty NPC patients with cervical LN metastases confirmed histopathologically underwent Te-99m MIBI SPECT and MRI of the head and neck to evaluate cervical LN metastases. For 16 LN lesions with discordant results between Tc-99m MIBI SPECT and MRI, Tc-99m MIBI SPECT could correctly detect 1 metastatic and 10 benign LN lesions as well as MRI could correctly detect 3 metastatic and 2 benign LN lesions. Agreement positive results of Tc-99m MIBI SPECT and MRI could correctly detect all of the remaining 24 metastatic LN lesions. Tc-99m MIBI SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with MRI. The combined use of Tc-99m MIBI SPECT and MRI could increase the accuracy compared with the single use of either Te-99m MIBI SPECT or MRI to detect cervical LN metastases in NPC.

Adult↗
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

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↗