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Biomedical subjects

Q H Liu

Publications and source records attributed to Q H Liu.

49 records · Page 3Linked to original sources
PubMed1994

Expression of human beta E-globin gene with erythroid enhancer in transgenic mice.

The human beta E-globin gene from HbE (beta 26 Glu-->Lys, G-->A) homozygote, a common hemoglobinopathy in China, was injected into the pronuclei of fertilized mouse eggs to prepare transgenic mice. A transgenic mouse bearing 16 copies of construct 5'.HS2 beta E has characteristics of typical transgenic mice. It has been verified that the presence of erythroid enhancer 5'HS2 is necessary for the high level expression of human beta E-globin gene in transgenic mice, indicating that the cis-element 5'HS2 is effective for abnormal beta-globin gene as well. Although the expression level of beta-globin gene was copy number-dependent as reported in previous studies, the average expression level per gene copy (12.1%) in transgenic mice bearing many copies of 5'HS2 beta E (16 copies) was significantly lower than that (79.7%) in transgenic mice bearing fewer copies of the gene (2 copies). The possible mechanisms for this decrease of expression are discussed. Novel hemoglobin tetramers which presumably consist of human beta E-globin chains and mouse endogenous alpha-globin chains have been assembled in transgenic mice.

Animals↗
PubMed1993

Effects of chronic ethanol on enzymes regulating sialylation and desialylation of transferrin in rats.

Transferrin is N-glycosylated glycoprotein and plays an important role in iron transport from sites of absorption and storage to sites of utilization. Chronic ethanol alters the normal microheterogeneity pattern of transferrin as a consequence of changes in the sialic acid content. However the underlying basis of this change in sialic acid contents of transferrin in alcohol abuse remains unclear. We have undertaken this study in order to investigate the effects of chronic ethanol in rats with respect to the hepatic rate of (i) transferrin synthesis based on labeled leucine incorporation, (ii) the incorporation of labeled N-acetyl mannosamine (NAM) into sialic acid residues of transferrin, and (iii) roles of specific sialyltransferase and sialidase at hepatic subcellular level. The results showed no significant difference in the incorporation of labeled leucine into transferrin at all levels between the control and ethanol group, whereas the incorporation of NAM into transferrin was significantly decreased by 84% (p < 0.001) both at the whole cell and Golgi level. Thus, the incorporation of labeled NAM relative to the incorporation of labeled leucine into hepatic transferrin was significantly decreased by 86% (p < 0.001) in chronic ethanol-treated animals as compared with the controls both at the whole cell golgi levels. These data are further supported by our finding of concomitant decrease in the activity of beta-galactoside alpha 2,6-sialyltransferase by 58% (p < 0.01) in ethanol-treated rats as compared with control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1992

Antigenic diversity of Rickettsia conorii.

Analysis of seven strains designated as Rickettsia conorii for reactivity with a panel of 12 monoclonal antibodies to surface-protein epitopes of spotted fever group rickettsiae and by Western immunoblotting with standard serotyping sera revealed remarkable antigenic diversity. Rickettsial strains from France, Morocco, Ethiopia, Kenya, South Africa, India, and the USSR differed from one another in reactivity with at least one and as many as five monoclonal antibodies. Simko and Indian strains were similar to one another and differed substantially from other R. conorii strains. All seven strains reacted with three R. conorii-specific monoclonal antibodies. Western immunoblotting demonstrated a major 120-kD protein and a major 135-kD protein in all strains. The principal differences were the presence of a major undenatured 130-kD protein in all strains except Indian and Simko, which had an analogous protein of 124 kD. Immunodominant antigenically related, heat-denatured protein bands of 170 kD (Malish 7 strain), 175 kD (Manuel strain), and 190 kD (Kenya tick typhus, Indian, and Simko strains) were not detected in the M-1 and Moroccan strains. This antigenic diversity is greater than that previously reported for other spotted fever group rickettsial species, suggesting that R. conorrii is an older species than R. rickettsii with a longer period of time for evolutionary divergence.

Animals↗
PubMed1992

[The protective effect of apolipoprotein C1 on endothelial cells injured by low density lipoprotein in vitro].

High serum low density lipoprotein (LDL) level is known injurious to endothelial cell (EC) and that high density lipoprotein (HDL) protects EC from such injury. The protective effect of HDL and apolipoprotein C1 (apo C1) on the endothelial cells (EC) isolated originally from human umbilical vein and injured by LDL was studied morphologically with phase-contrast and transmission electron microscope. Additionally, their functional changes were detected by measuring the amount of lactate dehydrogenase (LDH) and 6-keto-prostaglandin F1 alpha (PGF1 alpha) released. The EC were divided into four groups: control, HDL+LDL, apo C1 + IDL and LDL group. EC after being injured by LDL showed cell contraction, increased release of LDH and decreased secretion of PGF1. Anyhow, they would be left normal on morphology, LDH release and PGF1 alpha synthesis if HDL or apo C1 had been added to the culture media before LDL injury. The results indicated that both HDL and apo C1 can resist the injurious effect of LDL on the cultured EC.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

[Relationship between free cancer cells in the abdominal cavity, serosal type and pathologic characteristics of gastric cancer].

Of 100 cases of gastric cancer, free cancer cells in the abdominal cavity were detected in 32 (32%). In serosal typing, the free cancer cells were often found in the tendonoid (62.2%) and diffused colour types (60.0%). When the area of serosa invasion was over 20 cm2, the positive rate was 56.6% and only 2.5% if below 20 cm2. Incidence of free cancer cells was related to the depth of cancer infiltration, being often found in S2 and S3. It was also related to the pathologic characteristics of gastric cancer. Free cancer cells were often seen in infiltrating type (Borrmann 3,4); histologically differentiated or undifferentiated adenocarcinomas; nest or diffuse growing types. In patients without metastasis in the peritoneum (P0), the positive rate was 26.1%. This study proved that Chen's serosal classification is correct and useful in assessing whether the cancer cells have penetrated through the serosa during operation. Different treatment should be used in cases with different serosal types. In addition to rational surgical operation, killing of the free cancer cells should be considered in tendonoid and diffused colour serosal types so as to prevent peritoneal metastasis.

Adenocarcinoma↗
PubMed1987

Rickettsial and serologic evidence for prevalent spotted fever rickettsiosis in inner Mongolia.

A field study in northeastern Inner Mongolia, People's Republic of China, in June of 1985 demonstrated a spotted fever group rickettsiosis. Two strains of spotted fever group rickettsiae were isolated. One strain was obtained from the blood of a patient with an eschar, regional lymphadenopathy, and history of a recent tick bite. The other strain originated from ova of ticks, Dermacentor nuttalli. These represent the second isolate of a spotted fever group rickettsia from a human and the first isolate from tick ova in the People's Republic of China. Antibodies to these rickettsiae were demonstrated by indirect immunofluorescence in the sera of 4% of healthy children and 34% of healthy human adults, in 58% of sheep, and in 76% of cattle in the same location. Hemolymph test revealed rickettsiae in 6 of 36 D. nuttalli examined.

Adolescent↗
PubMedDate not supplied

Epidemiology and ecology of rickettsial diseases in the People's Republic of China.

Since 1949, information on rickettsial diseases in the People's Republic of China has been virtually nonexistent in the West. This is the first comprehensive review of the ecology and epidemiology of Chinese rickettsial diseases to be published outside the People's Republic. At least five rickettsioses exist in China: scrub typhus, murine typhus, epidemic typhus, Q fever, and one or more spotted fever-group (SFG) rickettsioses. Although epidemic typhus has been controlled and scrub typhus has abated in many areas, murine typhus, Q fever, and SFG rickettsiosis are important public health problems. Serologic surveys indicate high prevalences of antibodies to Coxiella burnetii, Rickettsia tsutsugamushi, and SFG rickettsiae in some regions; these rickettsiae have been isolated from humans, arthropods, and animals. Doxycycline has emerged as the best treatment for murine typhus, epidemic typhus, and scrub typhus. China offers both opportunities and challenges for the investigation and alleviation of the problems of rickettsial diseases.

Adult↗