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Biomedical subjects

J B Liu

Publications and source records attributed to J B Liu.

At least 109 records · Page 6Linked to original sources
PubMed1993

Galactose-based intravenous sonographic contrast agent: experimental studies.

A galactose-based sonographic contrast agent, which produces stable microbubbles capable of traversing the cardiopulmonary circulation, was used to enhance Doppler signals in blood vessels of varying size after intravenous injection. A series of experiments using dogs, rabbits, and woodchucks was conducted to establish the ability of the agent to enhance the reflectivity of normal tissue, tumor tissue, and blood. Although no enhancement was perceptible in tissue on the sonogram, significant enhancement of color and spectral Doppler signals was demonstrated in a variety of vessels. These included the aorta, vena cava, and portal vein as well as such small vessels as those of the retina of the eye, renal cortex, liver parenchyma, and gallbladder wall. Both spectral and color Doppler enhancement was shown in naturally occurring woodchuck hepatomas. Peak Doppler signal enhancement after bolus injection was approximately 10 dB with a dose of 0.01 ml/kg. Recirculation of the agent provided enhancement after intravenous bolus injection for more than 3 min. With a steady intravenous infusion of 0.2 ml/min/kg, Doppler signal enhancement of about 14 dB was maintained continuously for more than 5 min. The results of these animal experiments, in particular in small vessels and with recirculation after intravenous injection, suggest excellent potential for future clinical applications.

Angiography↗
PubMed1993

[Changes in hypothalamus-pituitary-adrenal (HPA) axis and the deficiency-excess syndrome differentiation on epidemic hemorrhagic fever patients].

UNLABELLED: In order to understand the relationship between the functional changes of hypothalamus-pituitary-adrenal (HPA) axis and the Deficiency-Excess Syndrome Differentiation of traditional Chinese medicine (TCM), the levels of serum cortisol and urinary 17-hydroxy-corticosteroid (U 17-OH) per 24 hours were studied. 171 serum samples and 139 urinary samples were obtained from 87 patients suffering from epidemic hemorrhagic fever (EHF) in various stage. RESULT: The Syndrome displayed as Excess-Heat type accompanied with Blood Stasis in febrile phase of EHF, both the level of serum cortisol and the U 17-OH increased to meet the stress. But the Syndrome converted from the Excess-Heat type to the Cold-Deficiency type in hypotensive and shock phase and the secretion of HPA axis began to reduce. However, in oliguric phase, the Syndrome was Kidney Deficiency complicated with Blood-Heat and Blood Stasis, their U 17-OH lowered significantly (7.53 +/- 3.82 mg/24 h.) in comparing with normal control (P < 0.01), but the level of serum cortisol, on the contrary, raised significantly (1517.96 +/- 421.96 mol/L) in comparing with control (P < 0.01). And in diuretic phase, the Syndrome was the Cold-Deficiency type, the HPA excretion tended to restore gradually but 17-OH maintain at a lower level in serious case. Therefore the change of serum cortisol was closely related with the HPA excretion in all phases of EHF, as well as to the Deficiency-Excess Syndrome Differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

17-Hydroxycorticosteroids↗
PubMed1992

Transnasal US of the esophagus: preliminary morphologic and function studies.

High-frequency catheter-based ultrasound (US) transducers can be inserted into the esophagus transnasally to evaluate esophageal wall structures. Studies were performed in two sheep esophagus specimens in vitro, in 17 healthy human subjects, and in 16 patients with esophageal abnormalities (eight with achalasia, four with scleroderma, three with esophageal carcinoma, and one with esophagitis). In the sheep specimens, endoluminal US delineated seven layers of the esophageal wall; these results correlated closely with histologic findings. Real-time US of the normal esophageal wall was performed during resting and swallowing. Muscles at the lower esophageal sphincter (LES) were shown to be thicker than muscles in the body of the esophagus. Thickening of the muscular layers at the LES in achalasia, dilated blood vessels within the submucosa in esophagitis, and fibrotic changes within the muscular layers in scleroderma were demonstrated. Extramural structures adjacent to the esophagus were also seen. These preliminary results suggest that transnasal esophageal US may become an important diagnostic tool in evaluation of the esophagus.

Adult↗
PubMed1992

Magnetic resonance imaging in hepatolenticular degeneration. Analysis of 9 cases.

Nine patients with biochemically proved Wilson's disease underwent magnetic resonance imaging (MRI) of the brain. Areas of abnormal signal, long T1 and long T2, caused by gliosis and edema were seen in the lenticula, thalami, caudatum, brain stem as well as in the dentate nuclei. The abnormalities were bilateral and symmetric. Asymmetric focal white matter lesions were noted in a few patients. Focal atrophies were seen in the head of caudatum. Symmetric cavitations were only seen in the lenticular nuclei. Acute progressive type (2 patients) was characterized by cavity formation, and chronic progressive type (7 patients) by gliosis, edema and focal atrophy.

Adolescent↗
PubMed1991

Endoluminal sonography of the urinary tract: preliminary observations.

Endoluminal sonography of the urinary tract was performed by using endoluminal ultrasound transducers contained within 2-mm-diameter catheters. The catheters were inserted into the urinary bladder via the urethra and advanced into the ureters and renal pelvis under cystoscopic control; then, cross-sectional images of the bladder, ureters, and renal pelvis were obtained. Two dogs and seven human patients were studied. In one dog, a 4.5-mm pseudopolyp, which was surgically created in the bladder wall, was successfully imaged; in the other, stones 2 mm or larger inserted into the bladder were identified. Of the seven patients, sonography showed stones embedded in the renal parenchyma (one patient) and the mucosa of the distal ureter (one patient). These were ultimately confirmed by their eventual removal. In a third, sonography showed a tumor of the distal ureter and identified the depth of the tumor. This was confirmed by biopsy. In a fourth, sonography clearly showed a crossing vessel as the cause for narrowing of the proximal ureter. In a fifth, sonography showed that the cause of a ureteral stricture was idiopathic. In the last two cases, sonography did not reveal a cause for hematuria. In these last three cases, negative sonographic results were confirmed by direct ureteroscopic examinations and follow-up studies. Our observations based on this limited study suggest that endoluminal sonography is a useful procedure for diagnosing diseases of the urinary tract. Further study is warranted.

Adult↗
PubMed1991

Endoluminal gynecologic ultrasound: preliminary results.

Specially developed high-resolution real-time ultrasound transducers (12.5 and 20 MHz) on the tip of endoluminal catheters were inserted into the endometrial canal to evaluate the usefulness of this approach. Uterine abnormalities, most confirmed by biopsy, surgery, or both, were detected in 12 patients, including submucosal myomas, nabothian cysts, endometrial polyps, synechiae, and endometrial and cervical carcinoma. In one case the catheter was directed under hysteroscopic guidance into a fallopian tube, demonstrating its potential usefulness in this region. In 4 of the 12 cases in which a hysterectomy was performed, an in vitro ultrasound examination of the organ was performed, which confirmed the initial in vivo ultrasound impressions. Anatomic cross-sectional slices of the uterus resulted in excellent correlation with the ultrasound findings. These preliminary results suggest that this new sonographic procedure will become an important diagnostic tool, supplementing abdominal and endovaginal ultrasound approaches.

Adult↗
PubMed1991

[Traditional Chinese medicine combined with Western medicine in the treatment of severe renal failure in patients with epidemic hemorrhagic fever].

This article reports the treatment of 23 cases (with the control group 20 cases) of severe renal failure in patients with epidemic hemorrhagic fever (EHF) by integrated traditional Chinese medicine and western medicine (TCM-WM), i.e., the renal protective decoction and modern medical treatment during the period of 1988-1989. The effects were as follows: (1) The curative rate was elevated and the morbidity was dropped (P less than 0.01-0.05). (2) Both the period of oliguria and albuminuria were shortened (P less than 0.01-0.05). (3) The severity of the complication, e.g., massive gastro-intestinal hemorrhage, etc., was much reduced (P less than 0.05). (4) The degree of azotemia was getting milder. And the renal function was much improved (P less than 0.05). The mode of action of the renal protective decoction is based on the point of view of the TCM in the treatment of infectious disease.

Acute Kidney Injury↗
PubMed1991

Endoluminal urologic ultrasound.

Miniature transducer-containing catheters (6 French 20 MHz and 9 French 12.5 MHz) have been inserted into the urethra, urinary bladder, ureter and renal pelvis. Real-time 360 degrees cross sectional ultrasound images were obtained delineating a variety of normal and abnormal structures in both animal models and humans. With this approach it was possible to measure wall thickness as well as adjacent external structures such as blood vessels, lymph nodes and muscle. It was possible to diagnose a variety of abnormalities including embedded stones in the ureter and renal pelvis, crossing blood vessels producing compression of the ureter and tumors within the urinary bladder and ureter. In addition, these transducer-containing catheters show promise in assisting in tumor staging and biopsy guidance. These specially developed transducer-containing catheters, intended originally for placement in blood vessels, show great promise in becoming important new tools in a wide variety of non-vascular lumina and surgically created openings in many areas of the body. From our initial results we can already predict that non-vascular endoluminal ultrasound will assume an important role in the evaluation of a variety of urologic abnormalities.

Animals↗
PubMed1990

Withdrawal phenomena after atenolol and bopindolol: haemodynamic responses in healthy volunteers.

1. The effect of withdrawal of atenolol and bopindolol administration was studied in 12 normal volunteers; six on each drug. 2. Following sub-maximal cycle-ergometer exercise training six sets of base-line observations were made of heart-rate (HR) and blood pressure (BP) responses; supine, 60 degrees head-up tilt, during graduated isoprenaline infusion and sub-maximal cycle exercise. 3. The results show that withdrawal phenomena occur following both drug treatments. Atenolol produced a hypersensitivity to isoprenaline and a small overshoot of HR in response to physiological manoeuvres. In contrast bopindolol produced a prolonged state of reduced sensitivity to isoprenaline and some evidence of overshoot of HR with physiological manoeuvres. The differences between the responses may be explained by the different properties of the two beta-adrenoceptor blocking drugs. 4. Some subjects showed clear evidence of overshoot of HR and BP on exercise demonstrating that certain individuals may be more prone to have withdrawal effects than others. 5. The length of time during which withdrawal phenomena can occur is probably longer than has previously been realised. 6. Hormonal changes were found in the withdrawal period (Walden et al., 1990).

Adrenergic beta-Antagonists↗
PubMed1990

Color Doppler imaging of the iliofemoral region.

Color Doppler imaging has been used to evaluate a variety of abnormalities in the iliofemoral region. This pictorial essay demonstrates how use of color Doppler techniques aids in the diagnoses of iliofemoral pseudoaneurysms, fluid collections, aneurysms, arteriovenous fistulas and malformations, venous thrombosis, vascular grafts, and soft-tissue masses including tumors and benign lymphadenopathy.

Color↗
PubMed1990

Endoluminal US: experiments with nonvascular uses in animals.

Catheters containing miniature ultrasound (US) transducers, originally developed for intravascular evaluation of plaque, were used in a series of in vivo and in vitro animal experiments to image a variety of nonvascular lumina. Measurements of the wall thickness and echotexture of the urethra, urinary bladder, ureter, renal pelvis, bile ducts, small bowel, fallopian tubes, and uterus were carried out. Close correlation between the US images and actual anatomic specimens was obtained. Structures outside of the lumen were identified and confirmed with both direct visualization and radiographic localization. Two small stones artificially inserted into the renal pelvis and a polyp-like projection artificially created within the fallopian tube were clearly identified by using the US probe. These initial US studies demonstrate the potential feasibility of these miniature transducers contained within catheters for intraluminal analysis in humans.

Animals↗
PubMed1990

Hepatic tumors: signal enhancement at Doppler US after intravenous injection of a contrast agent.

Experiments were carried out to detect and establish the origin of Doppler and echo signal enhancement in small vessels of the systemic circulation and of tumors after intravenous injection of a contrast agent. Eight woodchucks (Marmota monax) were studied; each woodchuck had naturally occurring hepatocellular carcinoma. Injections of 0.1-4.0 mL of air-filled human serum albumin microspheres were administered into a hind limb or jugular vein. Ultrasound (US) examination included transabdominal duplex scanning, color Doppler imaging, placement of a Doppler transducer on the exposed tumor, and surgical implantation of pulsed Doppler cuffs. Doppler signals were assessed by recording color Doppler images and results of spectral analysis. While subjective echo level was unaffected within the tumors, dramatic Doppler signal enhancement was recorded in both normal and tumor vessels. At optimum dose levels, a signal gain of approximately 10 dB was recorded from the tumor. Analysis showed that the echo enhancement was due to the presence of the contrast agent in branches of the hepatic artery. These results suggest that tumor detection may be enhanced by intravenous administration of a US contrast agent.

Animals↗
PubMed1990

[M2-type pyruvate kinase in the diagnosis of hepatocarcinoma--a pilot study].

By using Fab'-enzyme labelled immunosorbent assay (ELISA) at a sensitivity of picogram (10(-12) g or pg) level, M-type pyruvate kinase (M-PyK) in the plasma was determined in 47 healthy adults and 26 hepatocellular carcinoma (HCC) patients. The upper limits of M-PyK in the normal male and female were 1.1 and 1.4 ng/ml. The plasma M-PyK in HCC patients was significantly increased about 5 fold of the average normal level with a positive rate of about 95%. In 6 cases of subclinical small hepatocarcinoma and 7 cases of HCC with normal serum alpha-fetoprotein level, the plasma M-PyK was increased, whereas the plasma M-PyK levels were normal in acute or chronic hepatitis and the other benign diseases. After tumor resection, the plasma M-PyK returned to the normal value, but increased again in cases with recurrence, suggesting that the increased M-PyK in the plasma of HCC patients originates from M2-type PyK in HCC tissue. The plasma M2-PyK also increased in patients with carcinoma of the digestive tract, so M2-PyK may become a new marker of malignant tumors.

Biomarkers, Tumor↗
PubMed1990

Dilevalol: a dose-response study in normal volunteers.

Dilevalol, 100 mg, 200 mg and 400 mg, and placebo were given to eight normal volunteers and the effect on blood pressure and heart rate studied at rest and on exercise. There was a dose-dependent fall in exercising heart rate and in the increased heart rate on exercise with dilevalol, while exercising systolic blood pressure and the rise in systolic blood pressure on exercise fell dose-dependently up to 200 mg, but the effect of 400 mg was similar. Diastolic blood pressure was not affected. Supine heart rate and blood pressure changes were not different from placebo. Tilt heart rate fell most constantly from 200 mg. Some fall in tilt systolic blood pressure was seen but this was not dose-dependent, diastolic blood pressure was not affected. There was wide variation in plasma concentration of dilevalol, as might be expected from a liver metabolised drug, with a relatively larger amount absorbed of the 400 mg dose compared to the 100 or 200 mg doses.

Adult↗
PubMed1989

A log-dose-response study of xipamide and its effect on metabolic parameters.

An extended dose-response study with xipamide, using seven doublings of the dose, from 0.3125 to 40 mg/day at 4-week intervals, was carried out in 12 hypertensive patients. Blood pressure showed a progressive decline with doses from 5 to 20 mg, and 40 mg xipamide produced no greater fall. Some subjects showed a maximum fall in blood pressure with a single dose increase but most showed a declining blood pressure over two or more dose increases. Plasma urea increased with doses of 5-40 mg to a similar extent, but there was no fall in the mean potassium level except with the 40-mg dose. Urinary calcium was reduced (from 4.2 to 1.7 mmol/24 h) on the 40-mg dose and the corrected plasma calcium level rose from 2.28 to 2.32 mmol/l. Triglycerides, very-low-density lipoprotein cholesterol and plasma aldosterone increased at the maximum dose; the cholesterol ratio, however, was unchanged.

Blood Pressure↗
PubMed1988

Validity and reliability of the Chinese Hamilton Depression Rating Scale.

The reliability and validity of the Chinese version of the 17-item Hamilton Depression Rating Scale (CHDS) was assessed. Interrater reliability was excellent, the item total-score correlations were good, and the internal reliability was satisfactory. The concurrent validity was tested by correlating the CHDS score with the Global Assessment Scale score; the strong negative correlation found indicated that the CHDS reflects the overall level of disability. Five distinct factors were generated by principle-component analysis; these factors account for 52.4% of the total variance. Rigorous evaluation of the numerous translated scales being used in clinical and research settings of non-Western countries is important.

Adult↗