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Biomedical subjects

L M Liu

Publications and source records attributed to L M Liu.

At least 55 records · Page 3Linked to original sources
PubMed1993

[Studies of the spasm-relieving effect of Glycyrrhiza uralensis Fisch.--Aster tataricus L.F. pulvis mixture on the trachea in guinea pigs].

The experiment shows that high concentration of Aster tataricus plus Glycyrrhiza uralensis Fisch. can inhibit the tracheal systoliea caused by histamine, but for tracheal systoliea caused by acetylcholine the inhibition is indistinct. The experiment also shows that Aster tataricus, glycyrrhiza uralensis and Tussilago far fara L. combined have coordinated inhibiting effect on the tracheal systoliea caused by histamine and acetylcholine.

Acetylcholine↗
PubMed1993

[Clinical significance of tumor cell DNA analysis in patients with large hepatocellular carcinoma treated with irradiation combined with traditional Chinese medicine].

There has not been reported that DNA ploidy status of hepatocellular carcinoma may be used to predict the prognosis of patients with large liver cancer treated with radiotherapy combined with Chinese traditional medicine. In this series, the ploidy of DNA pattern in 28 cases were analyzed. Of them, the diploid accounts for 57.14% and aneuploid for 42.86%. Correlative analysis indicated that the clinical course of the disease in diploid cases was less severe than those in aneuploid ones (P < 0.05) and the response to treatment of patients with diploid DNA pattern was better than that of aneuploid ones (P < 0.01). However, there was no significant correlation between ploidy of DNA pattern and tumor size, AFP level or degree of differentiation of cancer cells (P > 0.05), which indicated that the ploidy pattern may be of significance in the treatment outcome of large liver cancer by radiotherapy.

Adult↗
PubMed1992

Induction and maintenance characteristics of anesthesia with desflurane and nitrous oxide in infants and children.

To determine the induction and maintenance characteristics of desflurane in pediatric patients, the authors anesthetized 206 infants and children aged 1 month to 12 yr with nitrous oxide plus desflurane and/or halothane in oxygen. Patients were assigned to one of four groups: anesthesia was 1) induced and maintained with desflurane after premedication with an oral combination of meperidine, diazepam, and atropine; 2) induced and maintained with desflurane; 3) induced with halothane and maintained with desflurane; or 4) induced and maintained with halothane. An unblinded observer recorded time to loss of consciousness (lid reflex), time to intubation, and clinical characteristics of the induction and maintenance of anesthesia. Moderate-to-severe laryngospasm (49%) and moderate-to-severe coughing (58%) occurred frequently during induction of anesthesia with desflurane; the incidence of these was not altered by premedication. In contrast, laryngospasm and coughing were rare during induction of anesthesia with halothane. In unpremedicated patients, time to loss of lid reflex (mean +/- SD) was similar for desflurane (2.4 +/- 1.2 min) and halothane (2.1 +/- 0.8 min). During induction of anesthesia, before laryngoscopy and intubation, mean arterial pressure less than 80% of baseline was more common with halothane; heart rate and mean arterial pressure greater than 120% of baseline were more common with desflurane. Intraoperatively, heart rate greater than 120% of baseline was more common with desflurane; blood pressures were similar for the two anesthetics. The authors conclude that the high incidence of airway complications during induction of anesthesia with desflurane limits its utility for inhalation induction in pediatric patients. Anesthesia can be safely maintained with desflurane if induced with a different anesthetic.

Anesthesia, Inhalation↗
PubMed1992

[Comprehensive "4-step analgesic ladder" therapy in treating cancer-related pain-analysis of 486 cases].

This analysis indicated that patients with cancer-related pain account for 71.0% in author's material. After the TCM treatment, the effective rate were 91.6% in hepatocarcinoma-related pain; 86.1% in colon-rectal cancer-related pain; 68.2% in malignant lymphoma-related pain; 100% in irradiation-related pain of esophageal cancer, lung cancer, post-operative breast cancer. Results of "four-step analgesic ladder" showed that 52.1% of pain could be relieved by Step I (TCM therapy); if Step II (indomethacin) or III (phenylbutazone) was added, the rate of pain relief reached as high as 96.5%; and only 3.5% need to be treated by Step IV (Opioids). With less side-effects and addiction of opioids and other narcotics, the "four-step analgesic ladder" therapy seems to be more suitable for cancer pain relief in China.

Adult↗
PubMed1991

A single-blind study of combined pulse oximetry and capnography in children.

This single-blind study examined four levels of monitoring in 402 pediatric cases. Patients were randomly assigned to one of four groups: 1) oximeter and capnograph; 2) only oximeter; 3) only capnograph; or 4) neither oximeter nor capnograph data available to the anesthesia team. An anesthesiologist, not involved in patient care, observed all cases and continuously recorded hemoglobin oxygen saturation (Spo2), ECG, expired CO2, and the oximeter plethysmographic output. Mean age, weight, ASA physical status, airway management (mask or endotracheal tube), and anesthetic technique were similar in each group. Two-hundred sixty problems were documented in 153 patients. Fifty-nine events in 43 patients resulted in "major" desaturation (Spo2 less than or equal to 85% for greater than or equal to 30 s). Fifteen "major" capnograph events (esophageal intubation, disconnection, accidental extubation, or obstructed endotracheal tube) were observed in 11 patients; 8 of these also developed varying degrees of desaturation. One-hundred thirty "minor" desaturation events (Spo2 less than or equal to 95% for greater than 60 s) and 79 "minor" desaturation events (hypercarbaria or hypocarbia) were observed. A number of problems fulfilled criteria in multiple categories. Infants less than or equal to 6 months of age had the highest incidence of major desaturation events (18 of 65 [27%]) compared to toddlers 7-24 months of age or children greater than 24 months of age (P less than 0.001). Blinding the oximeter data increased the number of patients (12 vs. 31) experiencing major desaturation events (P = 0.003); blinding the capnograph data altered neither the frequency of desaturation events nor the incidence of major capnograph events.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1991

Lymph-borne (veiled) dendritic cells can acquire and present intestinally administered antigens.

To investigate the ability of lymph-borne (veiled) dendritic cells (LDC) to acquire and present antigens in vivo, mesenteric lymphadenectomized rats were injected intra-intestinally with antigen and LDC were then purified from thoracic duct lymph. When used as antigen presenting cells with primed spleen cells as responders, the LDC could stimulate antigen-specific proliferation of the responder cells in the absence of exogenous added antigen. As little as 10 mg of ovalbumin (OVA) or horseradish peroxidase (HRP) injected into the ileum and jejunum could sensitize LDC for presentation. LDC acquired antigen within 8 hr of its injection but cells collected more than 24 hr after injection were unable to stimulate a response. Non-dendritic cells (NDC) in the thoracic duct lymph, such as B cells, were unable to present antigen either following intraintestinal injection or after in vitro pulsing. The antigen-specific response was blocked by antibodies to CD4 and major histocompatibility complex (MHC) class II and was totally dependent on the presence of CD4+ cells in the responding population. These studies show that dendritic cells can acquire antigens in vivo and provide a novel approach to the study of intestinal immune responses and oral tolerance.

Animals↗
PubMed1991

Apolipoprotein E is secreted by cultured lipocytes of the rat liver.

Hepatic lipocytes, the retinoid-storing cells of the liver, share several characteristics with vascular smooth muscle cells. To determine whether they also share the characteristic of apolipoprotein E secretion, we have compared the relative mRNA expression and protein secretion of apolipoprotein E, apolipoprotein A-I, and apolipoprotein A-IV in early primary cultures of lipocytes, hepatocytes, and Kupffer cells. Expression of apolipoprotein mRNAs was detected using the polymerase chain reaction and oligonucleotide primers specific for apolipoprotein E, apolipoprotein A-I, and apolipoprotein A-IV. Cellular mRNA concentrations were compared by dot blot analysis, and apolipoprotein secretion was assessed by immunoblot analysis of culture media. Apolipoprotein E mRNA was found in all three cell types, whereas apolipoprotein A-I and A-IV mRNAs were detected only in hepatocytes. Hepatocyte, lipocyte, and Kupffer cell media all contained a Mr approximately 36,000 protein identified by an antibody specific for rat apolipoprotein E. The relative concentration of apolipoprotein E mRNA per microgram of total cellular RNA in lipocytes, hepatocytes, and Kupffer cells was 1.0, 3.0, and 1.6, respectively. The relative secretion of apolipoprotein E per cell was also lowest in lipocytes, being twofold greater in hepatocytes and 1.4-fold greater in Kupffer cells. The secretion of apolipoprotein E by lipocytes is not only an additional smooth muscle cell-like characteristic of the hepatic lipocyte, but also raises the possibility of retinol mobilization upon apolipoprotein secretion.

Animals↗
PubMed1990

In vitro lymphocyte proliferation induced by radio-frequency electromagnetic radiation under isothermal conditions.

Whole human blood was exposed or sham-exposed in vitro for 2 h to 27 or 2,450 MHz radio-frequency electromagnetic (RF) radiation under isothermal conditions (i.e., 37 +/- 0.2 degrees C). Immediately after exposure, mononuclear cells were separated from blood by Ficoll density-gradient centrifugation and cultured for 3 days at 37 degrees C with or without mitogenic stimulation by phytohemagglutinin (PHA). Lymphocyte proliferation was assayed at the end of the culture period by 6 h of pulse labeling with 3H-thymidine (3H-TdR). Exposure to radiation at either frequency at specific absorption rates (SARs) below 50 W/kg resulted in a dose-dependent, statistically significant increase of 3H-TdR uptake in PHA-activated or unstimulated lymphocytes. Exposure at 50 W/kg or higher suppressed 3H-TdR uptake relative to that of sham-exposed cells. There were no detectable effects of RF radiation on lymphocyte morphology or viability. Notwithstanding the characteristic temperature dependence of lymphocyte activation in vitro, the isothermal exposure conditions of this study warrant the conclusion that the biphasic, dose-dependent effects of the radiation on lymphocyte proliferation were not dependent on heating.

Dose-Response Relationship, Radiation↗
PubMed1990

Analysis of the role of basic fibroblast growth factor in growth and differentiation of transplanted fetal rat paws and intestines.

Paws and intestinal segments from 16-day-old rat fetuses were transplanted bilaterally under the kidney capsule of adult female hosts and grown there for different periods of time. The direct effects of an antiserum to bovine basic fibroblast growth factor (bFGF) and of recombinant bFGF on growth and tissue differentiation in the transplants were evaluated by infusing them into the right renal artery via a catheter attached to an osmotic minipump. Infusion of the antiserum into the right kidney of intact hosts for 6 or 10 days did not affect either growth of the paws or bone differentiation in them. By contrast, the anti-FGF serum significantly inhibited the growth of intestinal transplants and caused slight retardation of villus differentiation. We presume that this inhibition resulted from neutralization of the bFGF produced within the transplants, as infusion of nonimmune rabbit serum had no such effects on the intestinal segments. In hypophysectomized hosts growth of both types of transplants was greatly reduced, and tissue differentiation was retarded, presumably reflecting low serum insulin-like growth factor-I levels. Infusion of the recombinant bFGF (5 micrograms/rat.day) into the hypophysectomized hosts stimulated growth of the paws and promoted ossification of the phalanges, but not the carpals. Intestinal growth was not affected by bFGF, and villus development was not restored. These results indicate that fetal rat structures are differentially dependent on and responsive to bFGF for growth and differentiation. These findings, when considered in relation to our previous results with transplanted 10-day-old rat embryos, indicate that growth and tissue differentiation during the embryonic period of rat development are more dependent on bFGF than are these processes in the fetal period.

Animals↗
PubMed1990

Glioma proliferation modulated in vitro by isothermal radiofrequency radiation exposure.

Isothermal (37 +/- 0.2 degrees C) exposure of glioma cells (LN71) for 2 h to 27 or 2450 MHz continuous-wave radiofrequency (RF) radiation in vitro modulated the rates of DNA and RNA synthesis 1, 3, and 5 days after exposure. The alterations indicate effects on cell proliferation and were not caused by RF-induced cell heating. The dose response for either frequency of the radiation was biphasic. Exposure to specific absorption rates (SARs) of 50 W/kg or less stimulated incorporation rates of tritiated thymidine (3H-TdR) and tritiated uridine (3H-UdR), whereas higher SARs suppressed DNA and RNA synthesis. Statistically significant time-dependent alterations were detected for up to 5 days postexposure, suggesting a kinetic cellular response to RF radiation and the possibility of cumulative effects on cell proliferation. General mechanisms of effects are discussed.

Cell Division↗
PubMed1989

In vitro fertilization of mouse ova by spermatozoa exposed isothermally to radio-frequency radiation.

Mouse spermatozoa were exposed in vitro for 1 h to 27- or 2,450-MHz CW RF radiation at SARs of 0 to 90 W/kg under isothermal (37 +/- 0.2 degrees C) conditions. Exposure at either frequency to RF radiation at SARs of 50 W/kg or greater resulted in a statistically significant reduction in the ability of irradiated sperm to fertilize mouse ova in vitro (P less than .05). Over the range of SARs there was no apparent difference in the effects of 27- vs. 2,450-MHz RF radiation. There were no readily detectable exposure effects on spermatozoan morphology, ultrastructure, or capacitation. The reduction of in vitro fertilization is attributed to a direct effect of RF radiation on spermatozoa rather than to heating.

Animals↗
PubMed1989

Neuromuscular and cardiovascular effects of doxacurium in children anaesthetized with halothane.

The neuromuscular and cardiovascular effects of doxacurium chloride (BW A938U) were evaluated in 27 children (2-12 yr) anaesthetized with 1% halothane and nitrous oxide in oxygen. In nine children the incremental technique was used to establish a cumulative dose-response curve by train-of-four stimulation. The remaining children received either 30 or 50 micrograms kg-1 of the drug as a single bolus. The median ED50 and ED95 of doxacurium in children were 19 and 32 micrograms kg-1, respectively. No clinically significant change in heart rate or arterial pressure occurred. Following doxacurium 30 micrograms kg-1 and 50 micrograms kg-1, recovery to 25% of control occurred in 25 (SEM 6) and 44 (3) min, respectively. The recovery index (25-75% of control) was 27 (2) min. The duration of action of doxacurium is similar to that of tubocurarine and dimethyl-tubocurarine in children. Compared with adults, children seem to require more doxacurium (microgram kg-1) to achieve a comparable degree of neuromuscular depression, and they recover more rapidly.

Anesthesia Recovery Period↗
PubMed1989

Treatment of pain according to syndrome differentiation in 169 cases of liver cancer.

In 169 cases with liver cancer pain, the therapeutic effects of TCM and the authors' "analgesic therapy of four steps" were analysed. The results were that most patients with advanced liver cancer had mild pain, and only a small number of patients (14.2%) had moderate or severe pain. By the first step analgesic therapy, 46.1% of the patients were relieved and with the second or third step of analgesic therapy, 93.5% of the patients were relieved, only 6.5% of the patients with grade III pain needed the fourth step therapy. With TCM treatment alone, the remission rate of grade I and grade II pain was 100% and 76.9% respectively. "Analgesic therapy of four steps" produced less side effects or addiction to narcotics.

Abdominal Pain↗
PubMed1988

Modulation of tendon fibroplasia by exogenous electric currents.

A chicken tendon explant model system has been developed to investigate the effects of extremely-low-frequency (ELF), low-amplitude, unipolar, square wave pulsed electric fields on fibroplasia in vitro. An electric field parameter set consisting of 1-Hz, 1-ms duration pulses, with a time-averaged current density of 7 mA/m2 (peak current density 7 A/m2) induced maximal (32%) increase in fibroblast proliferation in tendon explants exposed for 4 days. Exposure to the same field at an average current density of 1.8 mA/m2 had no effect on fibroblast proliferation, whereas exposure to current densities on greater than 10 mA/m2 inhibited proliferation and relative collagen synthesis, without affecting noncollagen protein synthesis. Fibroplasia was significantly increased in explants oriented parallel to applied electric fields having current densities of 3.5 or 7 mA/m2, but there was no detectable effect on explants oriented perpendicular to the same electric field. Fibroblast proliferation and relative collagen synthesis were inversely proportional to donor age for chickens in the 3- to 16-week age group used in this study. For these dependent variables (proliferation and relative collagen synthesis), there was no interaction between donor age and ELF electric field exposure.

Animals↗