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Biomedical subjects

R S Liu

Publications and source records attributed to R S Liu.

At least 19 recordsLinked to original sources

Liver disease after bone marrow transplantation--the Taiwan experience.

To investigate the causes of impaired liver function (LF)* after BMT, 88 patients were included for analysis of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, transplant methods, preconditioning regimens, and graft-versus-host disease (GVHD). Fifty of them (56.8%) developed abnormal LF after BMT and among them, 29 (32.9%) developed chronic hepatitis (CH). By univariate analysis, HCV infection, pretransplant abnormal LF, allogeneic BMT, and preconditioning regimen with total body irradiation were all significantly related to higher incidence of post-BMT impaired LF. However, only HCV infection, pretransplant abnormal LF, and acute GVHD were associated with higher incidence of CH. By multivariate logistic regression analysis, HCV infection and pretransplant abnormal LF were the two most significant interpreters for abnormal LF, especially for CH (odds ratios: 7.86 and 4.735, respectively) after BMT. Although the incidence of abnormal LF was found high in this study, there was no significant disadvantage in terms of survival for patients who developed abnormal acute and chronic liver function after BMT. However, a long-term follow-up is needed to evaluate survival pathology of CH, such as liver cirrhosis and hepatoma.

Adolescent

Lipiodol uptake and retention by human hepatoma cells.

Lipodol has important diagnostic and therapeutic uses in hepatoma. However, the mechanisms of its selective, prolonged retention in hepatoma cells is not well understood. Therefore, using oil-red O, light and electron microscopy and neutron activation analysis we have determined that HepG2 cells are characterized by lipiodol deposition and emulsification on the cell surface, action uptake of lipodol by endocytosis, and prolonged intracellular retention. These findings may have major clinical significance in the development of a new treatment for hepatoma patients.

Carcinoma, Hepatocellular

Tc-99m phytate bone marrow scintigraphy showing multiple areas of focal hyperactivity in a patient with lung cancer. A case report.

Focal hyperactivity indicative of metastases is a rare finding in bone marrow imaging. In a lung cancer patient with multiple bony metastases, the Tc-99m phytate bone marrow imaging revealed multiple focal areas of increased radioactivity corresponding to the bone scan findings. The findings presented are consistent with a previous animal study, which found that phytate distribution was similar to that of diphosphonate in the skeletal system of rats and rabbits. The authors conclude that Tc-99m phytate should not be used as a bone marrow imaging agent. Further studies of Tc-99m phytate bone marrow scintigraphy on human beings are under way.

Aged

Three-phase abdominal scintigraphy in lupus vasculitis of the gastrointestinal tract.

Gastrointestinal vasculitis is a recognized but frequently misdiagnosed complication of systemic lupus erythematosus. The authors investigated the usefulness of three-phase Tc-99m pyrophosphate abdominal scintigraphy for identifying areas of vasculitis in patients with systemic lupus erythematosus who have gastrointestinal symptoms (diarrhea or abdominal pain). Among patients with gastrointestinal symptoms, 62 of 82 (75%) patients showed positive scan results, suggesting gastrointestinal vasculitis. Among patients without gastrointestinal symptoms, 6 of 43 (13%) patients showed positive scan results. Although three-phase Tc-99m pyrophosphate abdominal scintigraphy cannot provide a definite diagnosis of vasculitis of the gastrointestinal tract, it is a noninvasive and convenient method for suggesting and monitoring gastrointestinal vasculitis.

Abdomen

Hypertrophic pulmonary osteoarthropathy in nasopharyngeal carcinoma: an early sign of pulmonary metastasis.

The aims of this study were to determine the incidence of hypertrophic pulmonary osteoarthropathy (HPO) in nasopharyngeal carcinoma (NPC) and assess its clinical significance. Altogether, 407 NPC patients were reviewed retrospectively. HPO was identified by 99Tcm-methylene diphosphonate bone scans and related clinical and radiographic evidence. Pulmonary metastases, bony metastases and titre of anti-Epstein Barr virus (EBV) immunoglobulin were assessed in patients with and without HPO. The patients had a mean (+/- S.D.) age of 50.4 +/- 12.4 (range 17-73) years. HPO was found in 27 of the 407 (6.6%) NPC patients, among whom 13 (48%) had pulmonary metastases. HPO preceded lung metastases by 7-22 months (14.4 +/- 6 months) in 7 (52%) patients. Six patients had overt lung metastases at the time of the bone scan. No significant difference was found in anti-EBV immunoglobulins between the patients with or without HPO, nor in the incidence of bony metastases between these two groups of patients. HPO should be regarded as an early sign of pulmonary metastases.

Adolescent

Photostationary state compositions of retinal and related compounds included in beta-lactoglobulin. Effects of protein host on isomer distribution of polyene substrates.

The UV-visible absorption spectra and photostationary state compositions of retinal (or the related C-18 ketone, 3-dehydroretinal and the C-22 aldehyde) imbedded in the binding cavity of beta-lactoglobulin (BLG) are consistent with the view that the carbonyl group of these polyenes are hydrogen-bonded with the protein host, most likely with the lone protonated lysine residue in the binding pocket. Patterns of variation in photochemical behavior of the imbedded chromophore versus that in solution are discussed in terms of possible specific protein-substrate interactions. The results are also compared with that of the methyl ether of retinol where similar hydrogen bonding is not possible.

Chemical Phenomena

99Tcm-HMPAO and 99Tcm-DTPA radioaerosol clearance measurements in idiopathic pulmonary fibrosis.

The clearance rate of an inhaled aerosol of a lipophilic complex, 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO), was compared with that of a hydrophilic complex, 99Tcm-diethylenetriamine pentaacetate (99Tcm-DTPA), in nine normal subjects and in eight patients with idiopathic pulmonary fibrosis (IPF). Data were acquired as follows. The subjects were placed supine with their back against the scintillation camera and breathed aerosol for 2 min; pulmonary radioactivity was then monitored for 30 min. A time-activity curve (TAC) was generated from the region of interest (ROI) over the periphery of each lung field and a computer program was then used to calculate percentage clearance per minute (k) in each lung. The mean (+/- S.E.M.) rate of clearance of 99Tcm-DTPA (k = 1.31 +/- 0.13% min-1) was not significantly different from that of 99Tcm-HMPAO (k = 1.32 +/- 0.27% min-1, P > 0.025) in the normal subjects. However, 99Tcm-DTPA clearance was 1.91 +/- 0.27% min-1 and 99Tcm-HMPAO clearance 0.78 +/- 0.17% min-1 in eight patients with IPF (P < 0.001, 99Tcm-DTPA vs 99Tcm-HMPAO). By regression analysis using a multiplicative model, both values correlated fairly [r = -0.71, y = exp (0.08-0.85 ln chi); P < 0.005], with a change in clearance rate in the opposite direction in all eight patients. The results of our study demonstrate that the pulmonary clearance of 99Tcm-HMPAO is different from that of 99Tcm-DTPA in IPF.

Aerosols

An appraisal of dipyridamole thallium imaging-detected ischemia in Chinese following acute myocardial infarction.

BACKGROUND: The detection of objective myocardial ischemia is an important work-up of risk stratification for survivors of acute myocardial infarction (MI). Intravenous dipyridamole thallium scintigraphy was used to identify the prevalence and prognostic value of silent myocardial ischemia (SI) at the early stage in patients after MI. METHODS: Ninety patients (male/female = 87/3; aged from 36 to 70 years) who succumbed to an episode of MI was recruited in this prospective study. Thallium imaging with reversible or combined defect was defined as presence of SI (Group I), while those with fixed defects or normal images were defined as absence of SI (Group II). Correlation between the patterns of thallium images for postinfarct ischemia and the angiographic lesions was investigated. Also, versatile clinical variables and indexes of adverse cardiac events: unstable angina, CHF, reinfarction, ventricular tachyarrhythmia and sudden death, were evaluated for their influence on patients' prognosis. The average follow-up was 11.6 months. RESULTS: There were 61 patients in the Group I as compared with 29 patients in the Group II. The difference of Killip functional classification between Group I and Group II patients was not significant (1.33 +/- 0.72 versus 1.07 +/- 0.59). Adverse cardiac event occurred in 30% (27/90) of the patients during follow-up. Cardiac death occurred in 6 cases (7%) and were distributed evenly (3 versus 3) in both groups. Group I patients showed a higher number of nonfatal reinfarctions (8 versus 5) and had more cases of percutaneous coronary angioplasty (11 versus 8) than Group II patients. Only two cases in Group I underwent bypass graft surgery. There was no statistic difference among four patterns of thallium image in the cumulative event-free survival curve. Prior history of CHF, prior MI and higher score index of proximal arterial stenosis were the three significant prognostic predictors for late cardiac events. CONCLUSIONS: Dipyridamole thallium imaging-detected SI was frequently seen in the Chinese patients following AMI. It was less valuable than prior histories of CHF, prior MI and higher index of proximal arterial stenosis scores in predicting the short-term unfavorable cardiac events in these patients. A large scale analysis and longer follow-up might be required to more accurately determine the role of this exam for the Chinese victims of myocardial infarction.

Adult

Enhanced immunogenicity of leucine enkephalin following coupling to anti-immunoglobulin and anti-CD3 antibodies.

Leucine enkephalin (Leu-enk) was coupled to both T and B cell antibodies in order to investigate the possibility of enhanced immunogenicity via targeted immunization. The two antibodies used were Hm x Mo CD3 and Gt x Mo Ig, respectively. The data indicate that while both antibody carriers enhanced the immunogenicity of Leu-enk, the use of the Hm x Mo CD3 antibody resulted in a greater number of mice with positive Leu-enk specific serum titers. 12 Leu-enk cell lines were produced and one, LE4H8, was chosen for characterization.

Amino Acid Sequence

Reappraisal of scrotal scintigraphy in evaluation of varicocoeles.

Varicocoeles could be classified into stop-type and shunt-type. In stop-type varicocoeles, only the internal spermatic (testicular) vein is dilated and needs to be ligated. In shunt-type, both internal spermatic vein and external spermatic (cremasteric) vein are dilated due to incompetence of the cremasteric system and both venous systems require ligation. Two-phase (flow and static) scrotal scintigraphy was performed on 92 patients preoperatively. Forty-three patients in whom the testicular and cremasteric veins could be verified during operation were included in this study. All 43 patients had unilateral varicocoeles and had abnormal blood pooling in the affected spermatic cord and hemiscrotum. In the blood flow study, 22 of 27 shunt-type varicocoeles had abnormal flow in the spermatic cord whereas only one out of 16 stop-type varicocoeles had increased blood flow. No difference in the results of semen analysis was found between the two groups of patients. Two-phase scrotal scintigraphy provides a noninvasive evaluation of shunting of the retrograde venous flow from the internal spermatic to the external spermatic vein. Understanding this pathophysiological change would be of benefit in the decision making about a surgical approach to varicocoeles.

Humans

Efficacy of quantitative cholescintigraphy in the diagnosis of sphincter of Oddi dysfunction.

The diagnostic efficacy of time-activity curves (TAC) and common bile duct dynamics (CBDD) derived from quantitative cholescintigraphy (QC) was assessed in patients with suspected sphincter of Oddi dysfunction (SOD). Quantitative cholescintigraphy was performed on 34 cholecystectomized individuals with suspected SOD and 26 asymptomatic controls. Each patient with suspected SOD underwent endoscopic retrograde cholangiography and sphincter of Oddi manometry (SOM). After exclusion of eight patients because of failure of manometry, the final diagnoses of the remaining 26 patients were taken as the gold standard by which to determine the detectability of TAC and CBDD. The sensitivity of TAC reached 68.8%. Common bile duct dynamics showed equal sensitivity but was more specific than TAC. The sensitivity improved to 87.5% when TAC and CBDD were combined. We conclude that non-invasive QC provides good sensitivity and specificity in evaluating cholecystectomized patients with suspected SOD.

Aged

Shape of the chromophore binding site in pharaonis phoborhodopsin from a study using retinal analogs.

To investigate the shape of the chromophore binding site of pharaonis phoborhodopsin (ppR), ppR-opsin was incubated with five ring-modified retinal analogs: an acyclic retinal, phenylretinal, alpha-retinal, cyclohexylretinal and 5-isopropyl-alpha-retinal. The experimental results were compared with those obtained from bacteriorhodopsin-opsin (bR-opsin) and the same retinal analogs. It was suggested that ring chain conformation is important in affecting the spectral shoulder unique for the absorption spectrum of ppR. The rate of pigment formation depended greatly on the analogs used with the planar analogs showing rapid formation. Thus, we concluded that the space of the retinal binding site of ppR is restricted to the plane of the cyclohexenyl ring of the chromophore, whereas that of bR is less restricted.

Archaeal Proteins

Temporal lobectomy in adults with intractable epilepsy.

We report on 30 adult patients with intractable complex partial seizure (CPS) of the temporal lobe origin who received anterior temporal lobectomy. The average follow-up period was 41 months. The age of onset was younger and the duration of epilepsy was longer in the non-mass lesion group than in the mass lesion group. Postoperatively, 21 patients (70%) were seizure-free, four patients (13%) had only rare seizures (less than three attacks per year), three patients (10%) achieved a remarkable reduction (more than 50%) of seizure frequency, and two patients (7%) showed no worthwhile improvement. Based on our experience, anterior temporal lobectomy is an effective and safe procedure for adult patients with intractable CPS. For diagnosis, magnetic resonance imaging (MRI) yielded a higher sensitivity rate than computed tomography (CT), especially in the group without mass lesions. Positron emission tomography using 18F-fluorodeoxyglucose (FDG-PET) was superior to single photon emission computed tomography (SPECT) which had a relatively high false localization rate. With high resolution MRI and FDG-PET, localization of the epileptogenic zone was more accurate. A preresection electrocorticogram (ECoG) was used to confirm the epileptogenic focus during the operation. The residual spikes on the postresection ECoG did not necessarily predict a poor seizure control outcome after anterior temporal lobectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Reactivation of hepatitis B virus in two chronic GVHD patients after transplant.

We report two cases of hepatitis B virus reactivation following allogeneic bone marrow transplantation (BMT) for severe aplastic anemia and acute myelocytic leukemia. The presence of antibodies to HBsAg, HBeAg and HBcAg prior to transplant indicated previous infection with hepatitis B virus (HBV). These antibodies disappeared 2 and 4 months after the onset of chronic graft versus host disease (GVHD) following immunosuppressive treatment, but HBsAg reappeared in their sera 6 and 10 months later, respectively. This suggests that chronic GVHD and immunosuppressive drugs can reactivate HBV in HBsAb-positive patients, most likely because of the decrease in quality and function of helper T cells and B cells during chronic GVHD to induce clearance of HBV antibodies and reactivation of HBV. Our observation confirms that patients with HBsAb, HBeAb and HBcAb present in their sera should not be considered to have 'immunity' to HBV after BMT.

Adult

Diagnosis of venous leakage by 133Xe corporeal clearance after intracavernous injection of prostaglandin E1 in poorly responding patients.

133Xe corporeal clearance after intracavernous (IC) prostaglandin E1 (PGE-1) injection was assessed in detecting venous leakage (VL) in a group of impotent patients with poor clinical response to PGE-1 injection. 133Xe corporeal washouts were done in the flaccid state and at full erection or at 20 min after the IC injection of 20 micrograms PGE-1 in cases where no full erection occurred in sequence on two separate days. In each case, data were acquired in frame mode after intracorporeal injection on one side of the midline just behind the glans of 0.1 ml, namely, 1-2 mCi (34-74 MBq) 133Xe in saline for 20 min. A time-activity curve was generated from the region of interest (ROI) at the site of injection and a computer routine was used to calculate clearance half-time (T1/2) in min and flow rate (Q) in ml per 100 g tissue per min. The data of 20 patients with equivocal response to IC PGE-1 were analysed. Of them, 14 had venous leakage and six had no vascular impairment (NVI). Venous leakage was proved by Doppler analysis, cavernosography after PGE-1, and/or selective arteriography. Twelve of 14 patients with VL had enhanced 133Xe corporeal clearance after PGE-1 with a significant decrease in T1/2 (mean +/- S.D.) from 115.9 +/- 196.0 to 13.3 +/- 13.4 (P less than 0.05) and increase in Q from 2.1 +/- 2.2 to 7.5 +/- 5.6 (P less than 0.01). In contrast, all six patients with NVI had decreased 133Xe corporeal clearance.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged