Search PubMed⌕ Search

Biomedical subjects

S Liu

Publications and source records attributed to S Liu.

At least 1,009 records · Page 56Linked to original sources
PubMed1992

Intracellular potentials of visceronociceptive neurons in posterior group of thalamic nuclei and its labeling with HRP intracellularly in cat.

The intracellular potentials (ICP) of 42 visceronociceptive neurons related to stimulating greater splanchnic nerve (SPL) in Posterior group of thalamic nuclei (PO) were investigated. We analyzed the electrophysiological features, such as amplitude of resting potentials and action potentials of the neurons. Following acquisition of electrophysiological data, (HRP) was injected into 3 neurons, whose responses were inducted by stimulating SPL (related neurons) and able to be inhibited by morphine intravenously. Two neurons revealing spontaneous discharges but are not able to evoke response by stimulating SPL (non-related neurons), also were stained by HRP. Two kinds of neurons, related and non-related ones, display different dendrite branching patterns.

Action Potentials↗
PubMed1992

[Effects of Ligustricum Wallichii on acute nephrotoxicity induced by cyclosporine A in rats].

We investigated the influence of cyclosporine A (CsA) on renal function, renin-angiotensin system (RAS) and platelet aggregation in addition to the effect of Ligusticum Wallichii (LW) on CsA actions in SD rats. Infusion of CsA (50 mg/kg, iv) resulted in a significant fall in glomerular filtration rate (GFR) and renal plasma flow (RPF) and a significant increase of plasma renin activity (PRA), angiotensin II (A II) level and percentage platelet aggregation. At the same time, treatment with 20% LW (8 ml/kg, iv) before CsA infusion significantly prevented the decline of GFR and RPF as well as the enhancement of platelet aggregation, but had no influence on CsA-mediated RAS activation. These results suggested that LW may be beneficial to the acute nephrotoxicity induced by CsA.

Acute Kidney Injury↗
PubMed1992

[Application of the regression orthogonal design to the fertilization of Psoralea corylifolia L. for optimum yield].

This paper probes into the determination of the optimum amount of fertilization by applying regression orthogonal design. After a significance test by regression equation, a regression equation can be set up, i. e. Y = 25.21 + 9.18 Xn + 15.68 Xp - 0.4 Xn2 - 0.98 Xp2 + 0.062 Xn Xp. This equation can be used to describe the relationship between yield and amount of fertilization.

Fertilizers↗
PubMed1992

[Estrogen and progesterone receptors in laryngeal carcinoma].

The existence of hormone receptors on or within neoplastic tissue has potential diagnostic, therapeutic, and prognostic importance. It has now been demonstrated in many reports that cancers of the breast and prostate often express hormone receptors and can be controlled by hormone manipulation. The fact that larynx is a target organ for androgenic steroids has long been known. The question of whether laryngeal carcinoma expresses hormone receptors has been a matter of interest. We adopted the fluorescent hormone conjugate method to measure the estrogen receptor (ER) and progesterone receptor (PR) in 25 patients with laryngeal cancer. Our findings indicated that in 25 samples of laryngeal cancer 48% were ER positive, and 68% were PR positive. Cells of the laryngeal cancer not only contain ER and PR but also have relationship between the presence of receptors and the degree of histologic differentiation. Low differentiated cancers are inclinable to contain low level receptors. From this initial survey it appears that the hormone receptors could play an important role in the cancer of larynx. The presence of receptors in some laryngeal carcinoma implicates that these tumors are possibly hormone sensitive.

Adult↗
PubMed1992

[Relationship among dosages of aminophylline, plasma levels of theophylline and variation of pulmonary arterial pressure].

The relationship among the dosages of aminophylline, plasma levels of theophylline and variations of mean pulmonary arterial pressure (mPAP) in 72 patients with COPD was investigated. The results showed that after a different loading dosage of aminophylline (6 mg/kg, 5 mg/kg and 4 mg/kg) was administered by intravenous injection, mPAP in the 6 mg/kg group was decreased more significantly (P less than 0.01) than that in the 4 mg/kg group. In the 6 mg/kg group, the decreased mPAP period sustained for 120 min, which was longer than that in the other 2 groups. The plasma levels of theophylline in the 6 mg/kg group of patients 30 to 120 min after loading dose injected were 115.54-79.04 mumol/L, which were higher than that in the others. Within the 120 min period of observation after the drug was administered no patients in any of these groups showed severe untoward effects. According to the results of this experiment, we suggest that the 6 mg/kg as a loading dose should be advised for the treatment of pulmonary hypertension in COPD. The optimum time to give the maintenance dosage should be set within 2 h after the loading dose. It is necessary to monitor the plasma levels of theophylline while aminophylline is administered, so that optimal therapeutic effects could be achieved without side effects.

Adult↗
PubMed1992

[Review of improving the technology of processing Chinese herbal medicines].

In this paper, the present situation of processing technology for Chinese herbal medicines is expounded in all aspects. Careful processing, overall developing and comprehensive utilization are put forward as improving ways, in the hope of providing a scientific basis for carrying forward the traditional processing techniques for Chinese herbal medicines in producing areas and putting the resources to full and rational use.

Drugs, Chinese Herbal↗
PubMed1992

[Changes in vascular stria after blast traumatized guinea pigs by colloidal lanthanum tracing technique].

The exudation of endotheliocyte in the capillary vessels of vascular stria after blast traumatized guinea pigs was studied by colloidal lanthanum tracing technique. The high density lanthanum ion shown as a line--distribution can be found in the endothelial surfaces of vascular stria by using transmission electron microscopy, but nolanthanum granulars were seen in the cytoplasm of endotheliocyte, the base membrane, and the tissular interval of vascular stria. At six hours after exposure to impulse noise, the lanthanum ion can exudate to the base membrane of capillary vessels through the closed-linkup between two endotheliocytes. On twelve hours after exposure, the exudation of the vascular endothelial cell membrane was increased and the lanthanum ion of the high electronic density was precipitated to the inside of cytoplasm. This study suggested that the impulse noise may have a obvious early effect on the exudation of vascular stria and the colloidal lanthanum tracing technique is a better method in studying the cochlear microcirculation.

Animals↗
PubMed1992

Physiologic comparison and validation of Stairobic stepping with bench stepping.

To compare the oxygen cost of submaximal exercise on the Stairobic stepping (SS) machine with bench stepping (BS), 12 healthy men and women (mean age 23 years) underwent six different five minute exercise bouts that were randomly assigned. Tests were conducted using standard open circuit calorimetry. SS at 40 and 60 st/min was equal to BS at 20 st/min and SS at 80 st/min was equal to BS at 30 st/min for VE and RER. VO2 was equal at 20 st/min (BS) and 60 st/min (SS), and 30 st/min (BS) and 80 st/min (SS). Stairobic MET (SM) displayed values over-estimated actual MET (AM) values at the two lowest SS rates and under-estimated the AM value at the highest SS rate. Forty-eight observations of the MET response of SS were conducted and analyzed (BMDP2R) in a forward stepping solution. The multiple regression equation calculated for AM was: AM = -0.567 + -0.012 (WT) + 0.063 (rate) + 0.612 (SM) with an adjusted R2 of 0.82 and a SEE of 0.90. The physiologic cost of BS was approximately equal to SS at two to three times the BS rate of stepping.

Adult↗
PubMed1992

Effect of cycloheximide on the adaptive response induced by low dose radiation.

Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.

Adaptation, Physiological↗
PubMed1992

Effects of m-nisoldipine and nisoldipine on electric activity of human atrial tissue.

Using intracellular microelectrode technique and microcomputer analyzing system, the effects of m-nisoldipine (m-Nis) and nisoldipine (Nis) on spontaneous electric activity of human atrial tissue were studied. APA and Vmax were remarkably decreased by m-Nis (0.25 and 1.25 mumol.L-1) and Nis (0.25 mumol.L-1). RPF was also greatly decreased as a result of inhibition in VDD. The inhibitory effects of m-Nis on transmembrane potentials were less than those of Nis at equal concentration (0.25 mumol.L-1). Neither MDP nor APD90 was affected by m-Nis and Nis.

Action Potentials↗
PubMed1991

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. I. The identification of viral genome and subgenomic sequences in biopsies of Chinese patients.

Biopsies from 318 cases with squamous cell carcinoma of the uterine cervix, 48 with cervical and vulvar condylomata, 14 with cervical intraepithelial neoplasia (CIN), 34 with chronic cervicitis and 24 with normal cervical epithelium were collected from different geographic regions with different cervical cancer mortalities. The DNA.DNA dot-blot and Southern blot hybridization results show that there is a close relationship between HPV-16 and the uterine cervical squamous cell carcinoma in China. One very interesting observation is that the finding of HPV-16-homologous DNA differs significantly among five geographic regions, and corresponds with the mortalities from cervical cancer of these five regions. HPV-11 was found mainly in benign lesions. The rate of detection of HPV-16 in Chinese women increased from 8.3% in normal cervical epithelium to 20% in chronic cervicitis, 28% in cervical condyloma, 50% in CIN and 60.4% in cervical cancer. It is suggested that HPV-16 infection may be an etiological factor in the development of human cervical carcinoma. From the results of Southern blot hybridization, it appeared that HPV-16 DNA had been integrated into the genome of the host cell in cervical cancer. Whereas the HPV-16 DNA sequence was only present as an episome in normal cervical epithelium and cervical benign lesions. The rate of occurrence of E6-E7 genes is the highest (88.9%) compared with that of other subgenomic fragments of HPV-16 in specimens of human cervical cancer in China. This implies that E6 and E7 may be the oncogenic genes of HPV-16 and play an important role in the carcinogenesis of human cervical epithelial cells. The amplification and rearrangement of the c-myc protooncogene are closely associated with the occurrence of cervical cancer. The results presented here revealed that the activated c-myc oncogene may cooperate with HPV-16 in the carcinogenic processes.

Biopsy↗
PubMed1991

A research for the relationship between human papillomavirus and human uterine cervical carcinoma. II. Molecular genetic and ultrastructural study on the transforming activity of recombinant retrovirus containing human papillomavirus type 16 subgenomic sequences.

In order to elucidate the role of HPV-16 in the development of genital cancer, NIH3T3 cells were transfected by HPV-16 whole genome and its two early genes, E6-E7. Besides ordinary calcium phosphate/DNA coprecipitation technique, a newly designed recombinant retrovirus containing the HPV-16 genome or subgenomes was used to infect cells for transfer of the target genes. The transforming activities have been demonstrated to be most efficient when a bioengineering technique of this kind is used. HPV-16 DNA was proved to have transforming potential for NIH3T3 cells, and the DNA of HPV-16 was proved to undergo multisite integration into transformed cells and nude mice tumour cells. The E6-E7 open reading frames are sufficient for transforming NIH3T3 cells independently in vitro, which implies that E6-E7 open reading frames are transforming genes or even viral oncogenes of HPV-16. The RNA transcribed by the E6-E7 of HPV-16 was expressed in transformed cells and in tumour cells of nude mice. The use of a recombinant retrovirus for gene transfer in this study is much more efficient than that of calcium phosphate/DNA coprecipitation. The lack of a tissue-culture system suitable for HPV replication in vitro makes HPV gene recombination into a specially engineered retrovirus for viral-mediated gene transfer of particular significance for the possible application of viral carcinogenesis, both in vitro and in vivo, for basic and clinical research.

Animals↗
PubMed1991

Failure to awaken after general anaesthesia secondary to paradoxical venous embolus.

A patient is presented who failed to regain consciousness after an apparently uneventful nine-hour revision of a total hip replacement. There were no clinically important haemodynamic changes during the operation, and oxygen saturation, capnography and acid base balance were normal throughout. Postop CT of the head showed a large left MCA infarct with midline shift. At autopsy, the patient was found to have a previously unsuspected patent foramen ovale, and a venous embolus in the left internal carotid artery, which probably had originated from the periprostatic venous plexus with a large infarct in the distribution of the left anterior and middle cerebral arteries. The authors conclude that massive paradoxical venous emboli can occur during surgery with minimal haemodynamic changes.

Anesthesia, General↗
PubMed1991

The effect of suramin, tumor necrosis factor and interferon gamma on human prostate carcinoma.

Suramin, an antiparasitic agent which has been shown to block the stimulatory effect of growth factors on certain cancers, is currently being evaluated in clinical trials and as an antineoplastic agent in patients with advanced prostate carcinoma. Preliminary studies suggested that suramin inhibits the growth in vitro of human prostate carcinoma. The present study was performed in order to evaluate the effect of suramin, recombinant human tumor necrosis factor (TNF), interferon gamma and the combination of suramin plus TNF or interferon gamma on proliferation of PC-3, a human, hormone unresponsive prostate carcinoma cell line. In medium containing 2% fetal calf serum (FCS) suramin, at doses of 10 microM, 30 microM and 100 microM (levels readily achievable in humans) inhibited proliferation of PC-3. TNF, at a concentration of 500 units/ml., induced an approximately 50% inhibition of growth of PC-3. The combination of suramin plus TNF induced a greater inhibition of growth than did either agent alone, even at the low dose of 10 microM suramin. Interferon gamma, 500 units/ml., inhibited PC-3 growth. However, the combination of interferon gamma plus suramin (30 microM) induced less inhibition of proliferation than did interferon gamma alone. These results may serve as a rationale for clinical trials employing the combination of TNF plus suramin in patients with advanced prostate carcinoma.

Antineoplastic Agents↗