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Biomedical subjects

Y Q Liu

Publications and source records attributed to Y Q Liu.

At least 73 records · Page 4Linked to original sources
PubMed1992

Acetylcholinesterase-containing neurons, substance P and enkephalin fibers in the ventral horns of developing human embryos and fetuses.

The presence of the acetylcholinesterase neurons and substance P-like and enkephalin-like fibers in the various nuclear columns of the ventral horns of the spinal cords was studied in the developing human by acetylcholinesterase histochemistry and substance P and enkephalin immunohistochemistry. Acetylcholinesterase-positive neurons initially appeared in the lateral neuronal columns and eventually were also observed in the medial columns as well as the median columns at various levels of the spinal cord by 10 weeks' gestation. Acetylcholinesterase-positive neurons in the lower sacral levels were not detected until 11-12 weeks' gestation. Diffused substance P- and enkephalin-like fibers were demonstrated as early as 10 weeks' gestation but did not align with any particular nuclear column until after 15 weeks' gestation. These fibers further increased in length and adopted reticular branching patterns and many of these tended to surround the cell bodies of the nuclear columns. Possible interaction of acetylcholinesterase neurons and substance P and enkephalin fibers would commence by 15 weeks' gestation.

Acetylcholinesterase↗
PubMed1991

Small-vessel pathology and anastomosis following maxillofacial firearm wounds: an experimental study.

This experiment was designed to provide a biological basis for early reconstruction of maxillofacial defects caused by firearms using free vascularized flap transfer. The pathologic changes of small-vessel injury, injury mechanism, and the feasibility for early anastomosis of these vessels in the maxillofacial region following high-velocity missile wounds were studied. Dogs' faces were wounded by a steel sphere, weighing 0.7 g and 1.03 g, with an initial velocity of 1,300 m/s or 1,500 m/s. Angiography and high-speed x-ray photography were used to record the effect of injury to blood vessels and other tissues. The pathologic changes in the small blood vessels in the wounds were studied by light microscopy (LM) and electron microscopy (EM). Anastomosis of small vessels in the wound was performed at different times after injury. There were temporary cavity effects and small vascular injury in the wounds. The pathologic changes of the small vessels included microthrombus formation, endothelial loss, breaks in the internal elastic layer, and necrosis. Degeneration of cells was found to end 3 cm from the wound edge. Anastomosis of the vessels performed 3 days after injury provided good short-term patency. These results suggest that the operation for repairing facial defects should be performed 3 days after injury.

Animals↗
PubMed1991

Indoor air pollution in four cities in China.

The study reports the investigation of indoor air pollution carried out in four cities in China (Chengde, Shanghai, Shenyang and Wuhan). The concentrations of RP, SO2, CO and NO2 were measured in kitchens and bedrooms, both in summer and in winter. The results showed that indoor air pollution, as measured by RP, SO2, CO, was heavy when coal was used as domestic fuel. This was particularly severe in winter. For example, the concentrations of SO2 in homes with coal stoves were more than 10 times higher than those in homes with gas or LPG in Shanghai. The concentrations of pollutants in kitchens were higher than those in bedrooms. The source of pollutants was fuel combustion from kitchen. The highest concentrations in kitchen could reach 665 micrograms/m3 (RP), 860 micrograms/m3 (SO2) and 14.07 mg/m3 (CO). The concentrations in bedrooms were up to 270 micrograms/m3, 502 micrograms/m3, and 13.67mg/m3, respectively.

Air Pollution, Indoor↗
PubMed1991

Special spectacles facilitating debridement. Report of use in 300 cases.

According to the difference of light reflection of tissue with different degree of viability, spectacles were made from glass permitting light of certain wavelength to pass to help distinguish viable from nonviable tissue. They were used in debridement of wounds in 300 patients. The results showed that the quality of debridement was improved as evidenced by better healing and shorter healing time. These spectacles were helpful, especially for young and unexperienced operators to distinguish viable from nonviable tissue. They were also used to predict flap viability in plastic surgery.

Arm Injuries↗
PubMed1989

Epidemiologic study of cancer mortality among chloroprene workers.

Both case-control and cohort studies were undertaken from July 1, 1969 to June 30, 1983 to ascertain whether exposure to chloroprene increases the risk of cancer. Fifty-five cases of cancer deaths were verified, 16 of which had histories of exposure to chloroprene ranging from 3 to 23 years (median 11 years) with a latent period of 8-27 years, except for one case of 3 years (median 12.5 years). Fifty-four pairs were obtained by matching the cancer deaths to noncancer deaths in accordance with strict requirements. The odds ratio for the paired data was 13, X2 = 8.64, P less than 0.005. The average age at death from cancer of workers exposed to chloroprene was 12.7 years younger than that of unexposed workers, t' = 2.98, P less than 0.001. The total cohort consisted of 1213 persons, among whom 149 (11.6%) had histories of exposure for over 25 years, 381 (31.5%) for over 20 years, and 852 (70.2%) for over 15 years. The SMR for the total cohort was 2.38 (P less than 0.01), and all SMRs for the high-exposure occupations were of significance (P less than 0.05 or P less than 0.01), in contrast to those of the low-exposure grups whose SMRs were low or zero. Thus, a dose-response relationship existed. Among the high-exposure occupations, maintenance mechanics seem to have the highest risk of cancers, and SMRs for liver, lung, and lymphatic cancers were significant in this group. These results suggested that chloroprene exposure increases the risk of developing cancer.

Butadienes↗
PubMed1989

[Studies on the mutagenicity of amrinone and milrinone].

The mutagenicity of domestic new drugs amrinone and milrinone were studied by Ames test, micronucleus test of mouse bone marrow and chromosome aberration assay in CHO cells. The results were as follows: neither amrinone nor milrinone was mutagenic in the Ames test; in chromosome aberration assay, both gave positive results; in mouse micronucleus test, amrinone gave a positive result when mice were exposed to 0.8 LD50 dose, but milrinone gave a negative result. These results suggested that amrinone and milrinone did not induce gene mutation, but amrinone induced chromosome damage both in vitro and in vivo, while the chromosome-damaging activity of milrinone in vitro may be minimized by biodetoxication in vivo.

Amrinone↗
PubMed1989

[A study of acute toxicity of mitoxantrone].

Acute toxicity of mitoxantrone (DHAQ) synthetized by Department of Organic Chemistry, School of Pharmacy, WCUMS was studied in mice and dogs. The toxic effects were compared with those of adriamycin (ADR). The LD50 were 6.6 +/- 1.3 and 7.1 +/- 1.6 mg/kg DHAQ, 7.9 +/- 2.1 and 10.7 +/- 2.2 mg/kg ADR (P = 0.95) respectively on observation with a single dose i.v. and i.p., for 21 days in Kunming mice. The toxicity appeared to be delayed with DHAQ and ADR. The earliest death occurred on 4th day after treatment in mice. In the third week still a few died. There were obvious decreases in WBC counts in the peripheral blood of mice receiving either 1-2.5 mg/kg DHAQ or 2.5-5 mg/kg ADR with a single dose i.p.. The WBC count could return to normality after 3 weeks with the withdrawal of the drugs. On electron microscopic examination of myocardial samples from mice 4 days after a single dose of 20 mg/kg DHAQ i.p., mitochondria swelling and vacuoles formation in some cells were shown. Besides the above-mentioned changes, some myocytes exhibited disorientation and loss of myofilaments in the mice which received equivalent dose of ADR. In dogs anaesthetized a temporary falling of blood pressure and slowing of heart rate were observed following 5-10 mg/kg DHAQ i.p.. When a dose of 50-100 mg/kg was given, the blood pressure dropped continuously until death.

Animals↗
PubMed1989

Influence of naproxen on uterine PGF2 alpha and the antifertility effect of IUDs in rats.

An IUD was implanted into one horn of the uterus in each of our experimental rats. The animals were mated with males of proven fertility about 2 weeks later. At day 1 of gestation (positive mating smear), the animals were treated with oral naproxen at 2 mg/kg per day or 20 mg/kg per day for 10 consecutive days. Control animals received saline. At day 16 the animals were sacrificed and the implantation rates and fetal survival and pregnancy rates were determined. The IUD completely prevented fetal survival and largely reduced implantation rates. Naproxen did not modify these parameters in either the IUD or the non-IUD horn. In a separate set of experiments, the reduction in uterine levels of immunoreactive PGF2 alpha (iPGF) was measured during the implantation period. Naproxen treatment for 5 days with 2 mg/kg per day or 20 mg/kg per day reduced iPGF from 6.71 +/- 0.93 to 2.19 +/- 0.34 and 1.01 +/- 0.18 ng/100 mg tissue, respectively (P less than 0.01). These data show that the suppression of uterine PG synthesis by naproxen does not interfere with the antifertility effects of IUDs in the rat.

Animals↗
PubMed1988

Wounding properties of steel pellets with different velocities and quality on soft tissue of dogs.

The characteristics of the soft-tissue wounds of the hind legs of 155 dogs produced by stainless steel spheres with four different masses and at various impact velocities were observed. It was found that when the mass of the spheres was identical, the velocity became the main factor to determine the severity of the damage; when the mass of the spheres was different but their kinetic energy was similar, then a smaller but faster sphere produced more severe damage than a larger but slower one. Shallow but wide and severe wounds usually resulted. The rate of disability of extremities with such wounds was very high. These wounding properties of steel spheres have caused some new problems in the treatment of war injuries.

Animals↗
PubMed1988

Wounding effects of small fragments of different shapes at different velocities on soft tissues of dogs.

The wounding effects of small fragments of the same weight (0.44 gm) but different shapes and at different impact velocities (708-1,560 m/s) on the soft tissues of the hind legs of 156 dogs were studied. The experiments showed that velocity was the major factor in causing wounds. For fragments of the same shape, the energy transmission, volume of wound cavity, sectional areas at entrance and exit, and amount of tissue that had to be excised increased rapidly with increasing velocity. In particular, as the velocity reached about 1,500 m/s, a shallow and wide wound tract was liable to occur, peripheral tissue lesion was relatively apparent, even extended to the whole leg, and the rate of occurrence of bone fracture was high. The wounding effect of the shape of the fragment closely related to its sectional specific weight (W) and drag coefficient (CD). Given the weight of the projectile and the density and thickness of the tissue, the energy transmission (delta E) was directly proportional to the square of the velocity and to the drag coefficient, and inversely proportional to the sectional specific weight of the fragment. Therefore, under certain conditions, reducing the sectional specific weight often increased the drag coefficient, in favour of causing a wound. In this experiment, the extent of wounds caused by the triangular, the square, and the cylindrical, and the spherical fragments decreased in that order, in agreement with their values of sectional specific weight and drag coefficient.

Animals↗
PubMed1988

Effect of high-velocity missile injury on plasma cortisol concentration in dogs.

Plasma cortisol concentrations were measured in nine dogs after high-velocity missile injury induced by spherical steel bullets. All nine dogs sustained soft-tissue wounds in the thighs without damage to large vessels, femur, or nerves. When the dogs were considered as one group the mean plasma cortisol concentration increased promptly 10 min after injury (p less than 0.05) and reached its peak at 1 hour and then decreased. The mean concentration at 6 hours after injury was still higher than that before injury (p less than 0.05). Even though the severities of the injuries varied rather much there was a significant difference (p less than 0.01) between the plasma cortisol concentrations at 1 hour of the two groups into which the dogs were divided according to the severity of their injuries. The changes of the plasma cortisol concentrations may be parallel with the extent of the injuries and there was a positive correlation with the dimensions of the entrance wounds.

Animals↗
PubMed1988

Reactions of serum creatine kinase in early phase of spherical steel bullet injury.

On the basis of experimental study on 17 dogs, this paper reports on the variation of serum creatine kinase (SCK) with time in the early phase of wounding by spherical steel bullets at three different velocities and its relation with the kinetic energy absorbed by the tissue and with the amount of the excised necrotic tissue surrounding the wound tracks. The results showed that the energy absorbed by the tissue and the amount of the excised necrotic tissue surrounding the wound tracks increased with increasing velocity. Within a period of 6 hours after wounding the SCK activity increased correspondingly.

Animals↗