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Biomedical subjects

L Qiu

Publications and source records attributed to L Qiu.

86 records · Page 5Linked to original sources
PubMed1995

Dietary fat: gene expression and mammary tumorigenesis.

Although discovered as an exogenous agent of mammary carcinoma, the mouse mammary tumor virus (MMTV) is also transmitted vertically as endogenous proviral DNA present in the germ line of all inbred mice. In the C3Hf mouse, which receives no exogenous virus, the initial event of mammary tumorigenesis is the transcription of the endogenous MMTV proviral DNA present at the Mtv-1 locus. Transcription occurs as a result of the hormonal effects of pregnancy, and Mtv-1 specific transcripts are seen in second-parity lactating mammary glands of these mice. As a means of studying the effects of diet on mammary carcinoma at the molecular/genetic level, we have studied the transcription of the Mtv-1 locus in C3Hf mice on a high-fat diet containing 46% fat in calories or a low-fat diet containing 10% fat in calories. We have detected an accelerated transcription of the Mtv-1 locus (first- vs. second-parity lactating mammary glands) in > 50% of the C3Hf mice on the high-fat diet. In addition, mice on the high-fat diet developed mammary tumors earlier (11 vs. 17.8 mos) and after fewer litters (2.1 vs. 4.2). Our results indicate that fat in the diet can affect gene expression related to mammary carcinoma.

Animals↗
PubMed1995

[Tolerance of reconstructive flaps to postoperative irradiation in oral and maxillofacial regions].

Eighty-three reconstructive flaps in oral and maxillofacial regions irradiated with a dose of 4000 to 7200 cGy were observed for a 2 year follow-up period. It was found that the rates of acute side effects including redswelling erosion and ulceration in the flaps were lower significantly than in neighbor oral mucosa (P < 0.01-0.05). The late radiation side effects of the flaps were uncommon also. The result showed that free flaps were well tolerated to postoperative irradiation of routine dose. Our studies indicate that the preoperative irradiation deficiency of blood supply or purulency were main reasons of the late radiation side effects, e.g. atrophy of epithelia, cicatrization or necrosis of the flap. Base on the results we have designed preventive measures.

Adult↗
PubMed1995

[Anatomical study of anterior branches of the lateral cutaneous nerve of the thigh].

100 anterior branches of the lateral cutaneous nerve of the thigh were dissected and measured in 50 adult cadavers. The results show that this nerve is present in all sides. The average length from the point of the nerve piercing fascia lata to the point of its first branch is about 79mm, the average width is 2.25 mm, and the average thickness is 0.79 mm respectively. It is found that the course of the nerve is approximately along the line between the anterior superior iliac spine and the midpoint of the patella. This study is benifit to the facial nerve grafting in clinic by providing data of the nerve.

Anthropometry↗
PubMed1995

Immunofluorescence quantitation of stromelysin in human synovial fibroblasts by confocal laser scanning microscopy.

BACKGROUND: Elevated levels of stromelysin have been reported in humans with osteoarthritis and rheumatoid arthritis, as well as in animal models of arthritis. However, a considerable amount of heterogeneity is observed in the expression of this enzyme in pathologic tissues as well as in in vitro systems. To analyze this variability, stromelysin expression was quantitated in individual human synovial fibroblasts (HSF) obtained from osteoarthritis patients. EXPERIMENTAL DESIGN: HSF were incubated with interleukin-1 (40 units/ml), an agonist known to induce stromelysin, in the presence or absence of dexamethasone (0.01 to 100 nM), an inhibitor of stromelysin transcription. With a stromelysin-specific antibody and a tetramethyl-rhodamine 5-isothiocyanate-labeled secondary antibody, the enzyme was visualized and the fluorescence in individual cells was quantified with an ACAS 570 laser cytometer in confocal mode. RESULTS: Stromelysin expression varied from one cell to another; however, on the basis of the magnitude of expression of stromelysin by each cell, the "nonresponders" within each treatment were identified. Approximately 34% of the cells showed a higher level of stromelysin expression in IL-1-treated HSF compared with controls. A dose-dependent inhibition in the expression of stromelysin was observed in response to increasing concentrations of dexamethasone. The dose-dependent changes in the accumulation of stromelysin protein correlated well with the stromelysin mRNA expression. CONCLUSIONS: Confocal laser scanning microscopy can be effectively used to analyze cellular heterogeneity in stromelysin expression.

Cells, Cultured↗
PubMed1995

[Observation on antibody levels of rabbits infected with single sex cercariae of Schistosoma japonicum].

Nine rabbits infected with male S. japonicum cercariae (worm recovery 15-133, mean 53.1) and 9 rabbits infected with female cercariae (worm recovery 1-102, mean 36.1) were bled periodically until 1 year post-infection. The sera were tested by ELISA, LA and CHR for antibody detection. Results showed that the positive rates were 88.9%, 55.6% and 83.3%, respectively. The duration of positive reaction was 3-51 wk post-infection for ELISA, 4-17 wk for LA and 2-35 wk for CHR and the fluctuated results were obtained in ELISA while positive CHR and LA results usually remained stable. The above-mentioned results suggest that antibody detection methods should not be neglected due to its sensitivity although antigen detection methods are considered more favorable. For the surveillance of schistosomiasis in endemic areas where schistosomiasis is under control, antibody detection methods are still worthy of recommending for case finding of new infections.

Animals↗
PubMed1995

[The anatomy of the maxillary ostium and the middle meatus antrostomy].

Serial cadaver dissections were performed and the anatomy of the natural ostium of the maxillary sinus and its adjacent structures observed. The results showed obvious anatomic variations. In most cases, the maxillary ostium was located in the infundibulum, directly under the orbit. The average distance was 1.1 cm from the maxillary ostium to the anterior maxillary wall, showing the anatomic relationship of the maxillary ostium with the nasolacrimal duct. The close anatomic relationship between the antronasal channel and orbit was demonstrated by radiography. A retrospective review of 70 middle meatal antrostomies was conducted and discussed. The anatomy of the antronasal channel should be well understood by an endoscope sinus surgeon in order to perform the middle meatal antrostomy without injuring the orbit and nasolacrimal duct.

Endoscopy↗
PubMed1994

Homozygous deletion, rearrangement and hypermethylation implicate chromosome region 3p14.3-3p21.3 in sporadic breast-cancer development.

DNAs from 19 malignant human breast tumors and 2 benign fibroadenomas were analyzed for heterozygosity at 5 polymorphic loci on the short arm of chromosome 3. One homozygous deletion and one rearrangement were identified using probe D3S2 which maps to 3p14.3-3p21.1. This probe also detected novel hybridizing fragments of 2.0 kb and/or 3.4 kb in 6/18 (33%) of the malignant tumor samples that hybridized with the D3S2 probe following digestion with the 5'-methylcytosine-insensitive enzyme MspI. Comparisons of HpaII and MspI digestion showed that all but one of the tumor DNAs analyzed were hypermethylated. The two fibroadenoma DNAs were not as highly methylated and had hybridizing fragments of 3.4 kb after HpaII digestion. These malignant breast-tumor DNAs exhibit 3 mechanisms by which a tumor-suppressor gene hypothesized to reside at 3p14-3p21 could be inactivated: homozygous deletion, rearrangement and hypermethylation, and strongly implicate this 3p chromosome region in breast-tumor development.

Breast Neoplasms↗
PubMed1994

Cholinergic neuronal differentiation factor (CDF)/leukemia inhibitory factor (LIF) binds to specific regions of the developing nervous system in vivo.

The cholinergic neuronal differentiation factor (CDF)/leukemia inhibitory factor (LIF) promotes survival and/or differentiation of specific neuronal populations in vitro. To investigate the spatial and temporal distribution of CDF/LIF binding sites in the developing rat nervous system, we localized binding of iodinated native rat CDF/LIF by radioautography. We find that specific CDF/LIF binding sites are present in distinct regions of the nervous system at defined developmental stages. CDF/LIF binding is detectable in all sensory ganglia examined, both neural crest- and placode-derived, and in all sympathetic and parasympathetic ganglia examined. In the central nervous system, in contrast, binding is restricted to specific regions in the motor, sensory, and limbic systems. These in vivo results not only support culture studies which suggest CDF/LIF involvement in development of specific populations of neurons, but also suggest new roles played by CDF/LIF.

Animals↗
PubMed1994

[Relationship between the sex of Schistosoma japonicum and circulating antigen detection].

Single sex cercariae were used to infect rabbits and the detection of circulating membrane antigen by dot-ELISA were followed up until 1 year postinfection. 9 rabbits infected with male cercariae (worm recovery 15-133, mean 53.1) and 9 rabbits infected with female cercariae (worm recovery 1-102, mean 39.1) were examined but no positive reaction was occurred. On the contrary, 7 rabbits infected with bi-sex cercariae (worm recovery 4-161, mean 67.1) all showed positive reactions 6-10 wks post-infection. Uni-sex female worms usually could not develop to maturity within rabbits even 1 year after infection, suggesting that the life-span of uni-sex female worm might be 1 year at least in rabbits. The uni-sex male worms could develop to maturity, being usually stout. The question why no circulating membrane antigen (even CCA, unpublished data) could be detected and the nature of antigen we detected needs further investigation.

Animals↗
PubMed1994

[Morphology and phagocytic activity of hemocytes of Oncomelania hupensis].

Hemocytes from Oncomelania hupensis hemolymph were studied in vitro. Spreading amoebocytes were the most common cell type. The average sizes of amoebocytes from Anhui and Yunnan were 8.42 +/- 0.73 x 7.46 +/- 0.52 microns and 7.63 +/- 0.65 x 6.85 +/- 0.54 microns, respectively. The nucleus was round in shape, and eosinophile granular inclusions were found in the endocytoplasm. Contacting with slide, the cells became flattened with extending pseudopodia. The ability of amoebocytes from snails of both localities to phagocytose sheep red blood cells was confirmed in vitro. The method to collect hemolymph from Oncomelania hupensis was developed, and the promise of this method in studying host-parasite relationship as well as epidemiological investigation of schistosomiasis japonica in the mainland of China was discussed.

Animals↗
PubMed1993

[Molecular genetic analysis on six cases of sex reversal syndrome].

Southern blot hybridization using Y-specific DNA probes and electrophoretic analysis of the SRY gene fragment amplified through polymerase chain reaction (PCR) have been performed in six cases of sex reversal syndrome (three 46, XX males and three 46, XY females). The result showed that the Y-specific DNA hybridization signal and SRY sequence were absent in one XX male and present in the remaining cases. This finding indicates that testis development of this XX male was initiated in the absence of the SRY gene.

Adult↗
PubMed1992

The C. elegans genome sequencing project: a beginning.

The long-term goal of this project is the elucidation of the complete sequence of the Caenorhabditis elegans genome. During the first year methods have been developed and a strategy implemented that is amenable to large-scale sequencing. The three cosmids sequenced in this initial phase are surprisingly rich in genes, many of which have mammalian homologues.

Animals↗