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Biomedical subjects

R L Liu

Publications and source records attributed to R L Liu.

At least 19 recordsLinked to original sources

Renal replacement lipomatosis.

We report a relatively rare case of renal replacement lipomatosis presenting as a renal mass. Computed tomography revealed a predominantly low-density and roundish mass, with an irregular renal parenchyma, high-density calcification, and abundant low-density fat. The differential diagnosis before surgery was squamous cell carcinoma, teratoma, or angiomyolipoma of the kidney. The case was initially misdiagnosed, because we had no experience with this disease. After mass exploration, histological examination confirmed the diagnosis of renal replacement lipomatosis. The patient was free from signs of recurrence 10 months after the operation.

Female↗

Growth of Qinghai Tibetans living at three different high altitudes.

This study compares the stature, weight, skinfolds, upper arm muscle area, and chest dimensions of Tibetan children, adolescents, and young adults who were born and raised, or who had lived from infancy, at 3,200 m, 3,800 m, and 4,300 m in Qinghai Province, People's Republic of China. While the individuals measured in Qinghai are among the tallest and heaviest Tibetans reported in the literature, they are nevertheless smaller and lighter than well-off children living at low altitude. The pattern of size variation among Tibetan males and females measured at the three high altitudes, along with evidence of a secular trend at 4,300 m, suggests that nutrition may significantly effect growth at high altitude. Only minor differences in thorax dimensions exist between Tibetan males and females measured at 3,200 m and 3,800 m. However, Tibetan males at 4,300 m possess slightly narrower and deeper chests (during and after adolescence) than males at 3,200 m and 3,800 m. Since individuals from 3,800 m and 4,300 m belong to the same local populations, this characteristic is unlikely to be genetically determined. However, it may be related to differences in the degree of hypoxia or to the influences of other environmental conditions.

Adolescent↗

Three new taxane diterpenoids from the seeds of the Chinese yew, Taxus chinensis var mairei.

Three new taxoids were isolated from the seeds of the Chinese yew, Taxus chinesis var mairei, their structures were established as 9alpha, 13alpha-diacetoxy-5alpha-cinnamoyloxy-11(15-->1)-abeo-taxa-4(20),11-diene-10beta, 15-diol, 2alpha,9alpha,10beta-triacetoxy-taxa-4(20),11-diene-5alpha,13alpha-diol and 2alpha,7beta,10beta-triacetoxy-5alpha-cinnamyloxy-9alpha-hydroxy-taxa-4(20),11-diene-13-one on the basis of 1D, 2D NMR, and MS spectral analyses.

Cinnamates↗

[Study on the relationship between allergic rhinitis and airway hyperresponsiveness].

OBJECTIVE: In order to study the relationship between allergic rhinitis and airway hyperresponsiveness. METHOD: Each of them were separately engaged skin test with antigen. All 50 patients had intense positive reaction to artemisia pollen (++-+++), but all controls were negative. We conducted bronchial provocation test (BPT) with 1:100 (w/v) artemisia pollen. Before and after BPT, we separately tested the forced expiratory volume in first second (FEV1) which represented ventilative function and eosinophil cationic protein (ECP) in their serum. RESULT: Before BPT, 50 patients and 20 normal controls had no trachea symptoms. FEV1 of 50 patients is (70 +/- 20)%, that normal controls is (85.6 +/- 8.9)% (P < 0.001). After BPT, in 50 patients, 23 cases felt constriction in the chest, 10 cases had wheezes, 5 cases had asthma, 12 cases had no symptoms. At the same time, all of normal controls had no symptoms. After BPT, FEV1 of 50 patients is (60 +/- 20)%, that of normal controls was (85.6 +/- 8.9)% (P < 0.05), ECP of patients was (30.37 +/- 18.92) micrograms/L, that of controls was (5.245 +/- 3.228) micrograms/L (P < 0.05). CONCLUSION: Patients with allergic rhinitis not only have chronic inflammation in their nose mucosa that results from allergic react, but also have chronic inflammation in bronchus which leads to AHR. The results reveal that most patients with allergic rhinitis have AHR (76%).

Adolescent↗

[Effects of poria cocos on ototoxicity induced by kanamycin in guinea-pigs].

In order to prevent the ototoxicity of kanamycin (KM), the effects of Poria Cocos (PC) on the ototoxicity induced by KM in guinea-pigs was observed by infusing the PC decoction into the guinea-pigs with comparing the difference in the general intoxicating symptom, prayer's reflex (PR) threshold, brainstem auditory evoked potentials (BAEPs) and the absence rate of outer hair cells in the first turn of cochlea. The results suggested that the ototoxicity of KM was retarded by giving the PC decoction. On 7th day after given KM, PR threshold of 4,6,8 kHz in the medicated group and control group were 4.7 +/- 1.5 dB, 5.7 +/- 2.4 dB, 2.7 +/- 1.2 dB and 10.5 +/- 3.2 dB, 12.1 +/- 3.7 dB, 8.5 +/- 2.7 dB respectively. BAEPs threshold on 13th day given KM raised 22.7 +/- 9.7 dB in the medicated group and 51.3 +/- 14.4 dB in control group. The absence rate of outer hair cells in first turn of cochlea were 39.4% and 67.4% respectively. The results suggested that PC might be antagonistic to the ototoxicity of KM in guinea-pigs.

Animals↗

[Measurement of the single muscle fiber action potentials and jitter value in tibialis anterior muscles of rabbits in situ].

With a home-made jitter data processing board and microcomputer for recording extracellular single fiber action potential (SF-AP), variations of the time intervals of the SF-AP pairs, or the jitters, from two adjacent muscle fibers in the unique motor unit in tibialis' anterior in response to repeated stimuli were measured. The jitter distribution of 936 recorded from 7 rabbits was positively showed with a percentile value of P75-P25 of 54.99-14.61 microseconds. The data suggested that the lower limit was smaller than that of skeletal muscles in normal human and that there exists also some differences in the jitter values of SFEMG between human and rabbit muscles.

Action Potentials↗

Hyperreiterated DNA regions are conserved among Bradyrhizobium japonicum serocluster 123 strains.

We have identified and cloned two DNA regions which are highly reiterated in Bradyrhizobium japonicum serocluster 123 strains. While one of the reiterated DNA regions, pFR2503, is closely linked to the B. japonicum common and genotype-specific nodulation genes in strain USDA 424, the other, pMAP9, is located next to a Tn5 insertion site in a host-range extension mutant of B. japonicum USDA 438. The DNA cloned in pFR2503 and pMAP9 are reiterated 18 to 21 times, respectively, in the genomes of B. japonicum serocluster 123 strains. Gene probes from the reiterated regions share sequence homology, failed to hybridize (or hybridized poorly) to genomic DNA from other B. japonicum and Bradyrhizobium spp. strains, and did not hybridize to DNA from Rhizobium meliloti, Rhizobium fredii, Rhizobium leguminosarum biovars trifolii, phaseoli, and viceae, or Agrobacterium tumefacians. The restriction fragment length polymorphism hybridization profiles obtained by using these gene probes are useful for discriminating among serologically related B. japonicum serocluster 123 strains.

Chromosome Mapping↗

Application of biotin-avidin system, determination of circulating immune complexes, and evaluation of antibody response in different hydatidosis patients.

The avidin-biotin-peroxidase complex enzyme-linked immunosorbent assay (ABC-ELISA) and standard ELISA were used for the detection of Echinococcus granulosus antibody in sera of 101 patients operated on for hydatid disease, 40 patients with miscellaneous nonhydatid diseases, and 61 normal subjects. Sensitivity and specificity of the two procedures were comparable and the geometric mean antibody titer detected with ABC-ELISA was higher than with standard ELISA. The ABC-ELISA is a sensitive, specific, simple, and convenient method for diagnosing hydatidosis.

Animals↗

Changes in myocardial oxygen demand and instantaneous ventricular vascular volume during prolonged cross-clamping and reperfusion of the abdominal aorta.

In 47 animals (rats, rabbits) the cardiac side effects of prolonged (3 to 6 hours) abdominal aortic cross-clamping and unclamping (3 to 6 hours) were investigated. The relative instantaneous ventricular vascular volume (IVVV), a factor reflecting myocardial blood supply and the rate pressure product (RPP) representing myocardial oxygen demand were used as parameters. Following cross-clamping the IVVV showed an initial decrease while the myocardial oxygen demand revealed a sudden increase. After unclamping, the myocardial oxygen demand decreased and IVVV improved. Minimal levels of both IVVV and RPP occurred at 6 hours following unclamping. This may be an effect of a myocardial inhibiting substance, released by ischemia and necrosis of the lower extremity.

Animals↗

Experimental assessment of phased-array heating of neck tumours.

An investigation of phased-array microwave systems (PAMS) for non-invasively inducing hyperthermia, primarily in neck lesions, has been done with implications for applications at other sites such as lung and pelvis. Our general approach was to combine numerical and analytical approaches with parallel experimental studies. In this paper we will concentrate only on the experimental aspects. The object, such as a homogeneous cylindrical phantom or a neck phantom, was encircled with several standard applicators driven by a single source, but with relative phase and amplitude control over each applicator. The relative phases of the applicators were adjusted by using an implanted monopole antenna connected to an HP network analyser. Power was applied and the specific absorption rate (SAR) was determined by using split phantoms and thermography or by measuring temperature transients dT/dt, recorded by implanted thermometer probes. We found that at 915 MHz for our applicators (SMA Co.) the centre of an 11 cm diameter muscle-like phantom heated to about 33% of the value at the surface in front of the applicator. Similarly, we were able to show significant SAR at the centre of realistically sized neck phantoms using four phased apertures of 915 MHz. Furthermore, substantial improvement was observed if the frequency was lowered to about 400 MHz.

Animals↗