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Biomedical subjects

R S Liu

Publications and source records attributed to R S Liu.

At least 145 records · Page 8Linked to original sources
PubMed1990

Report of a pilot study of intra-arterial injection of I-131 lipiodol for the treatment of hepatoma.

This pilot study in 10 hepatoma patients investigated the feasibility of using selective targeting of radioisotope (I-131) lipiodol in the treatment of hepatoma patients. Lipiodol is a contrast medium that selectively goes to hepatoma and remains there for a long period as compared with that in normal liver and other tissues. Lipiodol was labelled with I-131 and infused into the hepatoma via the hepatic artery. Selective targeting of I-131 to hepatoma was demonstrated with a radiation dose ratio (hepatoma to normal liver) of up to 25 to 1. The biodistribution data of I-131-lipiodol in this study also confirmed the selective targeting of the radioisotope (I-131) to the hepatoma. Tumor radiation dose up to 26,000 rads can be delivered by this method. The treatment results were encouraging. About 70% of hepatoma patients had response to the treatment with reduction of alpha-fetoprotein and decrease of hepatoma sizes. The overall median survival was 9 months (range 2-17 months). This treatment was simple, safe, effective, non-expensive and well tolerated by all patients without major side effects. The optimal dose, schedule, duration of this treatment are still under investigation.

Adult↗
PubMed1990

Transfer function analysis of the ventricular function: a new method for calculating right ventricular ejection fraction.

The relationship between the ventricular transfer function and ejection fraction has been investigated by the routine procedure of first-pass radionuclide angiocardiography. Ejection fraction has been shown to equal 1-e(-b), where b is the ratio of the R-R interval over the mean transit time difference between ventricular and atrial time-activity curves. To evaluate the effect of region of interest (ROI) on the right ventricular ejection fraction (RVEF), the results of the transfer function analysis (TFA) technique using precise ROI, TFA using rectangular ROI, and the routine method were compared. Regression analyses among RVEFs obtained from the above ROI methods yielded good correlations. Reliable RVEFs have been obtained even in the case of an improper bolus injection. Thus, the TFA technique is a new, simple, and reliable method for calculating RVEF without needing to outline the right ventricle precisely.

Heart↗
PubMed1989

Diagnosis of vasculogenic impotence: combination of penile xenon-133 washout and papaverine tests.

The present study evaluates both penile xenon-133 washout (XWT) and papaverine tests (PT) in the diagnosis of vasculogenic impotence. XWT was accomplished by subcutaneous injection of xenon-133 (1-2 mCi in 0.1 mL saline solution) into the dorsal coronal prepuce. Abnormal XWT was suggested in patients whose clearance time (T1/2) was longer than 7.5 minutes and whose penile blood flow rate (Q) was less than 6 mL/100 g tissue/min. PT was done by intracavernous injection of papaverine (60 mg in 20 mL normal saline). Abnormal PT was indicated in patients whose onset of full erection was more than ten minutes after papaverine injection and whose duration of erection was less than one hour. Ten young and 11 older normal volunteers were examined with XWT only; all showed normal results. A total of 60 impotent patients were examined with both XWT and PT and were classified into four groups: in 2 patients (3.3%) both XWT and PT were normal (group I); in 8 (13.3%) XWT was abnormal and PT normal (group II); in 14 (23.3%) XWT was normal and PT abnormal (group III); and in 36 (60%) both XWT and PT were abnormal (group IV). On further examination with bilateral hypogastric arteriography in 10 XWT-abnormal patients and on surgical correction of abnormal curvature in 5 XWT-abnormal patients, all (100%) were proved to have penile arterial insufficiency. Erection cavernosography performed in 15 PT-abnormal patients confirmed penile venous insufficiency in 80 percent. We conclude both XWT and PT are simple and effective for evaluation of the penile arterial blood flow and venous competence, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Treatment of acute leukemia with rifampin and low dose harringtonine. Analysis of 14 cases.

We evaluate the efficacy of rifampin combined with low dose harringtonine in acute leukemia (Group A, acute lymphocytic leukemia (ALL) 6 cases and acute non-lymphocytic leukemia (ANLL) 8 cases) in comparison with the patients treated with low dose harringtonine only (Group B, 8 ALL, and 5 ANLL). The complete remission (CR) rate in Groups A and B was 64.3% and 23.1%, while the median CR duration, 17 months and 8 months respectively, Group A was more effective than Group B. We also consider that rifampin and low dose harringtonine are more applicable for treatment of ANLL patients without peripheral leukocytosis and those complicated with infection.

Adolescent↗
PubMed1989

[Immunocytochemical demonstration of S-100 protein in adenoid cystic carcinoma of the salivary gland].

Immunocytochemical study was performed for the presence of S-100 protein in adenoid cystic carcinoma (ACC) of salivary gland and normal salivary gland tissues with the immunogold-silver staining method (IGSS). Myoepithelial cells, intercalated duct cells and serous acinar cells of normal salivary gland were S-100 positive. In ACC, S-100 protein can be found in component cells of various histological patterns of the tumor. The results suggest, according to the distribution patterns of S-100 protein positive cells in the tumor tissues, that ACC may originate partly from intercalated duct cells and partly from myoepithelial cells.

Carcinoma, Adenoid Cystic↗
PubMed1989

The clinical significance of a new monoclonal antibody defined antigen CA195 as a tumor marker in colorectal cancer.

We evaluated a new monoclonal antibody defined antigen CA195 as a tumor marker in patients with colorectal adenocarcinoma and compared the results with CA19-9 and carcinoembryonic antigen (CEA). This study included 37 patients with colorectal adenocarcinoma, 118 healthy subjects, 20 hepatitis with or without jaundice, and 20 duodenal ulcer with or without smoking habits. The average concentration of CA195 in serum from 118 healthy subjects is 5.80 +/- 6.83 U/ml. In the 37 patients with colorectal adenocarcinoma, 13 had elevated levels (greater than 30 U/ml) of CA195 (35%), 10 had elevated levels (greater than 37 U/ml) of CA19-9 (27%), and 18 and elevated levels (greater than 5 ng/ml) of CEA (48%). The sensitivity of CA195 is correlated well with the extent of the malignancy, 9% in Duke's stage A and B, and 79% in advanced stage C and D. Although the sensitivity of CA195 is less than CEA (35% vs. 48%), this difference is not statistically significant scaled (P greater than 0.05). Combined use CA195 with CEA can increase detecting rate from 48% (CEA alone) to 59%. CA-195 level may be elevated in some patients with hepatocellular disease, but its level is not affected by smoking. Therefore CA-195 can be applied as complementary tumor marker in colorectal cancer.

Adenocarcinoma↗
PubMed1989

[Prediction of postoperative pulmonary function in the patient undergoing pneumonectomy using combined pulmonary function test and ventilation/perfusion scintiphotography].

A method to predict postoperative lung function following pneumonectomy has been used in 11 patients. Preoperative unilateral lung function can be predicted by combining the preoperative information on lung volumes obtained by spirometry with the distributional information obtained from ventilation and perfusion scintigrams in order to estimate lung function after pneumonectomy. There was a high degree of correlation between predicted and measured lung function for both FEV1 (r = 0.81, p less than 0.050, and FVC (r = 0.81, p less than 0.05). The postoperative FEV1 and FVC were within 200 ml of the predicted value in most of the patients. A more accurate and easy prediction of postoperative lung function is obtained using unilateral perfusion rather than ventilation scintigrams. We suggest that the combined the results of simple spirometric data and a quantitative right-vs-left perfusion lung scan using radioactive Tc-99m provides a simple non-invasive and accurate method for the pre-operative functional evaluation of the high risk patient.

Adult↗
PubMed1989

Xenon-133 hepatic retention ratio: a useful index for fatty liver quantification.

Xenon-133 hepatic retention ratio was developed for quantifying fatty liver. Data were acquired in frame mode in the hepatic region and both lung bases for 5 min after rebreathing 20 mCi of gaseous 133Xe and for another 5 min during washout. Static [99mTc]sulfur colloid liver imaging was performed with the patient in the identical position immediately after the ventilation study and data were stored for liver localization. A hepatic time-activity curve corrected for background activity was generated. The 133Xe retention ratio was derived by dividing the activity at 3.5 min after washout by the peak activity. The data of 16 controls and 20 patients with fatty liver were analyzed. The retention ratio (mean +/- s.d.) was greatly increased in patients with fatty infiltration (0.43 +/- 0.20 vs. 0.04 +/- 0.08 in controls, p less than 0.001). There was a strong positive correlation between the 133Xe retention ratios and percentage of fat on biopsy as assessed by the amount of the liver tissue occupied by fat globules on H & E stained sections. The 133Xe hepatic retention ratio is a simple, accurate and clinically useful index of detecting, quantifying and managing fatty infiltration of the liver.

Adult↗
PubMed1988

9,13-dicis-rhodopsin and its one-photon-one-double-bond isomerization.

Incubation of purified 9,13-dicis-retinal with cattle opsin in 2% digitonin at 20 degrees C produced two pigments, one unstable (lambda max 478 nm) and the other stable (lambda max 485 nm) in hydroxylamine. The two pigments exhibited different characteristics. HPLC analysis revealed that the chromophores of these pigments have respectively 9,13-dicis and 9-cis geometries. Under various conditions the amount of 9,13-dicis-rhodopsin formed never exceeded 30% of the total pigments. The addition of 9,13-dicis-retinal to the ROS suspension containing opsin produced 9-cis-rhodopsin in 97% yield. Irradiation of the 9,13-dicis-rhodopsin mainly produced 13-cis-retinal, while 9-cis-rhodopsin produced the all-trans isomer. These results demonstrated that the one-photon-one-double-bond isomerization process took place in 9,13-dicis-rhodopsin.

Animals↗
PubMed1988

The spectral properties and photosensitivities of analogue photopigments regenerated with 10- and 14-substituted retinal analogues.

Analogues of 11-cis- and 9-cis-retinal with substitutions at positions 10 and 14 were used to regenerate analogue photopigments with two opsins: that of the transmuted (cone-like) 521-pigment of Gekko gekko and that of the rhodopsin of Porichthys notatus. The spectral absorbances and photosensitivities of the regenerated photopigments were determined and compared, first, between the two systems of analogue photopigments, and second, in the responses to the two opsins. Unlike the 10-fluoropigments, the comparable 14-compounds were significantly red-shifted by 19-30 nm and their sensitivity to light was similar to that of the parent 11-cis- and 9-cis-pigments. These were the results for both analogue pigments. In contrast, the 10-pigments were spectrally located close to the wavelengths of the parent compounds and the photosensitivity was significantly reduced, especially in the case of the 9-cis-analogues. Evidence was obtained for a steric hindrance effect at position 14, for no regeneration was obtained when methyl or ethyl groups were at this carbon. In the 10-substituted retinals, steric hindrance was noted only for the gecko; only the fluorosubstituted, but not the chloro-, the methyl- or the ethyl-substituted, retinals reacted. With the fish opsin, pigments were regenerated with all but the ethyl-substituted retinal. The gecko opsin appears to have a more restricted binding site. Another feature of the gecko was related to the chloride bathochromic and hyperchromic effects, in which the 521-pigment prepared in a chloride-deficient state has a blue-shifted spectrum compared with the spectrum obtained after the addition of chloride, and its extinction is raised by the addition of chloride to give a mean ratio of 1.23 for the two extinctions, one with, the other without, added chloride. The 11-cis-10-F-analogue pigment gave both chloride effects and the hyperchromic ratio was the same as that recorded for the native visual pigment. In contrast, the pigment formed with 11-cis-14-F-retinal gave a hyperchromic ratio significantly greater than 1.23. A similar contrast in the responses to chloride was obtained with the analogue photopigments regenerated with the 9-cis-10-F- and 9-cis-14-F-chromophores. This difference between the two systems is interpreted as the result of a specific configurational feature of the gecko opsin when in the chloride-deficient state that is relevant to the binding of the retinal analogue.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Electrostatic interaction between retinylidene chromophore and opsin in rhodopsin studied by fluorinated rhodopsin analogues.

Photochemical reactions of fluorinated rhodopsin analogues (F-rhodopsins) prepared from 10- or 12-fluorinated retinals (10- or 12-F-retinals) and cattle opsin were investigated by means of low-temperature spectrophotometry. On irradiation with blue light at liquid nitrogen temperature (-191 degrees C), the F-rhodopsins were converted to their respective batho intermediates. On warming, they decomposed to their respective fluororetinals and cattle opsin through lumi and meta intermediates. There was a difference in photochemical behavior between batho-12-F-rhodopsin and batho-10-F-rhodopsin. Upon irradiation with red light at -191 degrees C, batho-12-F-rhodopsin was converted to a mixture of 12-F-rhodopsin and 9-cis-12-F-rhodopsin like that of the natural bathorhodopsin, whereas batho-10-F-rhodopsin was not converted to 9-cis-10-F-rhodopsin but only to 10-F-rhodopsin. This fact suggests that the fluorine substituent at the C10 position (i.e., 10-fluoro) of the retinylidene chromophore may interact with the protein moiety during the process of isomerization of the chromophore or in the state of the batho intermediate. On irradiation with blue light at -191 degrees C, 9-cis-10-F-rhodopsin was converted to another bathochromic intermediate that was different in absorption spectrum from batho-10-F-rhodopsin. 9-cis-10-F-rhodopsin was practically "photoinsensitive" at liquid helium temperature (-265 degrees C), whereas 10-F-rhodopsin was converted to a photo-steady-state mixture of 10-F-rhodopsin and batho-10-F-rhodopsin. The specific interaction between the fluorine atom at the C10 position of the retinylidene chromophore and the opsin was discussed in terms of electrostatic interactions.

Animals↗
PubMed1987

Three-phase bone scintigraphy in Pellegrini-Stieda disease.

In a patient with Pellegrini-Stieda disease, radiographs of the knees were unremarkable at the time the three-phase bone scintigraphy was abnormal. The results of follow-up radiographs three months later remained normal in the left knee, where local steroid injection was given, but revealed typical positive results in the right knee with no treatment. The three-phase bone scintigraphic pattern is rather typical and antedates the radiographic changes. Thus, the radionuclide technique would provide a useful procedure for the early diagnosis and treatment of Pellegrini-Stieda disease.

Adolescent↗
PubMed1986

Study of the shape of the binding site of bovine opsin using 10-substituted retinal isomers.

The 9-cis, 11-cis, 13-cis, and all-trans isomers of 10-fluoro-, 10-chloro-, 10-methyl-, and 10-ethylretinals have been prepared and characterized. Results of their interaction with bovine opsin are reported. The data have been analyzed in terms of the conformational properties of the retinal isomers and their steric compatibility with the binding site as defined by the two-dimensional map disclosed earlier. The need to expand the active zone and previously undetected restrictions in the third dimension are noted.

Animals↗