Biomedical subjects
Publications and source records attributed to X Qu.
In clinical trials, the extract of Ottelia alismoides cured two cases of bilateral tuberculosis of cervical lymph gland within 3 months. The result of drug sensitive test showed that water extract of this herb could kill or inhibit human tubercular bacteria effectively, which suggests that Ottelia alismoides is a promising medicinal herb with anti-tubercular effect.
Previous work has established that synaptic input influences the differentiation of muscle and glandular targets and that these targets reciprocally influence the differentiation of the innervating neurons. In contrast, there is little information on the impact of pre- vs postsynaptic contact on the differentiation of neuronal targets. We have delineated the timing of presynaptic projections to lumbar sympathetic neurons as well as the timing of the projections from these neurons to their targets during normal embryonic development. A combination of anterograde and retrograde labeling techniques and immunohistochemical approaches reveal that the establishment of significant synaptic input to chick sympathetic ganglia is a rather protracted process spanning late embryonic development. Although target contact in the periphery also occurs over mid to late embryogenesis, significant target projections appear to be established prior to the evolution of a comparable level of presynaptic input. Analysis of concurrent changes in the pattern and levels of expression of genes encoding neuronal nicotinic receptor (nAChR) subunits are consistent with both presynaptic input and target contact regulating nAChR expression during embryogenesis. These studies also suggest that retrograde influences of target contact on receptor expression may be more substantial than previously appreciated.
Natural vibrational optical activity consists of two principal forms. The IR form is known as vibrational circular dichroism (VCD) and is simply the extension of electronic circular dichroism into the IR vibrational region of the spectrum. The Raman form, known as Raman optical activity (ROA), is a new form of optical activity that has no counterpart in the classical forms of optical activity. In this paper, the similarities and differences of the IR and Raman forms of vibrational optical activity will be examined. Although both VCD and ROA were discovered and confirmed in the period from 1973 to 1975, each field has evolved independently with key advances in theoretical description, instrumentation and application coming at different times over the past 20 years. The current relative strengths and weaknesses of VCD and ROA will be discussed, and specific examples of VOA spectra of (-)-alpha-pinene and the amino acid L-alanine, for which overlapping VCD and ROA data are available, will be presented.
"In order to qualitatively portray the combined quality level of community population and societal development [in China], this author has developed a model for evaluating the quality of population and development in poor communities (or regions) and comparing cross-region developmental differences on the basis of an in-depth field study conducted in some poor counties and communities."
Gene expression of epidermal growth factor receptor (EGFR), epidermal growth factor (EGF) and transforming growth factor-alpha (TGF alpha) in human colonic carcinoma cell lines (HT10, LST174 and Lovo) was studied by using Northern blot technique. Total RNAs were isolated from these cell lines, separated by 1% agarose gel electrophoresis, transferred onto a membrane and hybridized with EGFR, EGF and TGF alpha probes. EGF and EGFR mRNAs were found in all three cell lines, and TGF alpha mRNA was seen in LST174 and HT10 cell lines but not in Lovo. The results indicate that autocrine stimulation by growth factor exists in human colonic carcinoma cell lines and it may be one of the important causes for the uncontrolled growth of carcinoma cell.
Sixty-six children with hyperkinesia were treated with the Yizhi (wit-increasing) syrup, after which their scores on behavior dropped, their school records improved, and the rate of appearance of soft neurotic signs lowered, all three changes being significant, giving a total effectiveness rate of 84.8%. After the treatment, examination of the 24-hour urine showed significant increases in its content of norepinephrine (NE), dopamine (DA), 3-4 dihydroxy phenylacetic acid (DOPAC), cyclic adenosine monophosphate (cAMP), and creatinine (Cr).
The double-stranded replicative form of dengue 2 virus (DEN-2) RNA (Tonga strain) was used as a substrate to produce DNA clones of the NS1-NS2A genes via reverse transcriptase synthesis of full length cDNA followed by polymerase chain reaction amplification of the NS1-NS2A region. Products were cloned into pTZ18R for sequencing and into baculovirus for expression studies. The deduced amino acid sequence of the NS1-NS2A was almost identical to that of the S1 attenuated strain of DEN-2 Puerto Rico 159, differing in only four amino acids. The NS1 protein expressed in insect cells [Spodoptera frugiperda (Sf-9)] from the baculovirus recombinant was indistinguishable from authentic NS1 of DEN-infected Aedes albopictus cells in glycosylation, dimerization, cellular presentation and antigenicity. Mice injected with the expressed protein developed NS1-specific complement-fixing antibodies and were partially protected against neurological residua after intracranial challenge. The protective effect was mouse strain- and gender-specific.
A method is described for cloning large fragments (1.5 kb to 2 kb) of dengue virus cDNA from replicative-form viral RNA. Aedes albopictus cells (C6/36 clone) infected with dengue virus contain double-stranded, replicative-form RNA molecules which were used as a template for an initial reverse transcription using a primer containing sequence homologous to regions of the genome at or near the 3' end of the gene being studied. The product was then used as a template for polymerase chain reaction (PCR) amplification using the same 3' primer and a second which hybridized to a region at the 5' end of the sequence to be cloned. Both primers were engineered to contain specific restriction enzyme cutting sites which enabled the PCR product to be cut and cloned directly into plasmids for sequencing and expression studies. We have used this method to construct clones of the envelope glycoprotein gene (E) and the non-structural genes 1 and 2a (NS1/2a) and 3 (NS3) of dengue type 2, Tonga 1974 strain, and E and NS1/2a from dengue type 3, H-87 strain, either as discrete genes or as constructs with long and short leader sequences, with or without anchor sequences. The method could be applied to the cloning of any gene from any flavivirus, directly from infected cell extracts, without the necessity for tedious virus purification steps.
Various mechanical forces produce a variable stimulus intensity on bone and have different effects on its growth and development. The aim of this project was to study the effects of a variety of mechanical forces on human humerus morphology. This was investigated by measuring the cortical thickness (cm) and diameter (cm) of the humerus at its proximal, middle and distal thirds from radiographs. The humerus of each of 46 men (five controls, six swimmers, eight gymnasts, seven javelin throwers, nine discus throwers and 11 weightlifters) was radiographed on both right and left sides. The humerus size variation among the participants, in order of increasing size, was found to be as follows: gymnasts, controls, swimmers, javelin throwers, weightlifters and discus throwers respectively. The humeral cortex was largest in the weightlifters, being significantly (P less than 0.05) thicker at distal, medial and proximal sites. The proximal and distal humeral sites in javelin and discus throwers were significantly thicker than those of the control subjects. From the results, static load would seem to provide a higher stimulus to bone than dynamic loading.
Neutrophils are one of the weapons of host defenses against microbial infection. Their ability to kill the invading microorganisms depends on two principle mechanisms. One depends on production of reactive oxygen intermediates (ROI) by stimulated neutrophils, and the other depends on the delivery of antimicrobial contents of the neutrophils' cytoplasmic granules, oxygen-independent. The defensins have the highest concentration in the neutrophils, and the broadest antimicrobial spectrum, being capable of killing gram-positive and gram-negative bacteria, fungi and some envelope viruses. We purified human defensins from the neutrophils' granules by gel permeation chromatography and SDS-preparative acrylamide gel electrophoresis. The molecular weight of human defensins is between 3,000-4,000 daltons. After testing, C. neoformans was susceptible to these defensins. Under condition of 37 degrees C, pH 7.4 and low ionic strength, antifungal activity by human defensins was related to its concentration and incubating time. All of these illustrate that nonoxidative killing mechanism of neutrophils, especially the function of defensins is very important in host defenses.
In this morphological study of the effects of training on myocardial capillaries, four week old Wistar rats were selected to accept four months of treadmill training. The rats were then sacrificed for morphological study of myocardial capillaries by means of perfused Chinese ink, AKP stain and ultrathin section methods. The results showed that the number of capillaries in trained rats was increased markedly by 14.8 per cent (P less than 0.05) in the outer layer and 13.7 per cent (P less than 0.05) in the inner layer. The ratio of capillaries to myocardial fibres was increased by 17.6 per cent and 13.7 per cent (P less than 0.05) respectively. The area and girth of capillaries in the trained rats were increased by 25 per cent and 26 per cent (P less than 0.01) respectively. Collateral branches in the trained rats were also increased and were more irregular in shape or appeared locally expanding and tortuous. Unopened capillaries were often observed in the control rats, while in the trained rats, no unopened capillaries were observed. In addition, the small vacuoles in the cytoplasm of endothelial cells were also increased.
"In this paper, I will undergo an analytical research of the vagueness of the process of marriage and marital age parameters. Consequently, I will deduce from this research a fuzzy mathematical model of the distribution of first marriage age....I intend to bring to light a general rule followed by marital age relations and, therefore, enable its simple and precise application to quantitative analysis and theoretical studies." The geographical focus is on China.
Explore the source record for details and available documents.
OBJECTIVE: To investigate the interaction of dexamethasone and interleukin-1beta (IL-1beta) on the expression of cytosolic phospholipase A(2) (cPLA(2)), the enzyme catalyzing the first reaction in the formation of prostaglandins, in cultured primary human amnion fibroblasts. DESIGN AND METHODS: Human amnion fibroblasts were prepared from fetal amnion collected at term and were treated with dexamethasone with or without interleukin-1beta for 24h. Prostaglandin E(2) (PGE(2)) output and cPLA(2) expression in cultured amnion fibroblasts were measured with radioimmunoassay, quantitative real-time polymerase chain reaction, Western blotting and cPLA(2) promoter-driven luciferase reporter gene activity. RESULTS: Both dexamethasone and IL-1beta caused a significant increase in prostaglandin E(2) output, cPLA(2) mRNA and protein expression in cultured human amnion fibroblasts. Both dexamethasone and IL-1beta stimulated cPLA(2) promoter-driven luciferase reporter gene activity. There was no obvious antagonistic or synergistic effect of combined treatment of dexamethasone and IL-1beta on PGE(2) output, cPLA(2) expression or cPLA(2) promoter-driven luciferase reporter gene activity in cultured human amnion fibroblasts. CONCLUSION: The above findings suggest that paradoxically dexamethasone is a stimulator for both prostaglandin synthesis and cPLA(2) expression in human amnion fibroblasts. The interaction between dexamethasone and IL-1beta on prostaglandin synthesis and cPLA(2) expression is neither synergistic nor conventionally antagonistic.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Arsenic trioxide (As(2)O(3)), has been used for centuries in traditional Chinese medicine; it has considerable efficacy in the treatment of relapsed acute promyelocytic leukemia, inducing partial differentiation and promoting apoptosis of malignant promyelocytes. Although a number of studies have demonstrated that As(2)O(3) has potent activity against cell growth in a series of leukemia cell lines, little information is available regarding this compound's effect on cell growth in solid tumor cell lines. In this study, we investigated the effects of As(2)O(3)in vitro on ovarian cancer cell lines sensitive (3AO) and resistant (3AO/CDDP) to cisplatin. The 3-(4,5-dimethy-thiazoyl-2-yl)-2,5-diphenyl-tetrazolium bromide assay was used to evaluate cytotoxicity. Flow cytometric analysis was used to determine the apoptosis, cell cycle distribution. We clearly demonstrated that As(2)O(3) induced cell apoptosis and inhibition of cell growth in both the cell lines. Furthermore, we identified that As(2)O(3)-induced apoptosis involved Fas pathway. As(2)O(3) is an active agent against ovarian cancer cells and could be effective in the clinical treatment of ovarian cancer.
Because the efficacy of genetic prodrug activation therapy (GPAT) using herpes simplex virus thymidine kinase (tk)/ganciclovir (GCV) or Escherichia coli cytosine deaminase (cd)/5-fluorocytosine (5-FC) is not satisfied in early clinical trials and the mechanism of both the GPATs have been shown to lead to the activation of cell apoptotic pathway, we hypothesized that coexpression of procaspase-3, a central downstream executioner of apoptotic pathways, with cd-tk gene leads to enhanced cell death in ovarian cancer cells in vitro. Following transfection with the vectors encoding cd and tk, 5-FC and GCV treatments lead to greater cell death in procaspase-3-expressing clones of 3AO (3AO-caspase-3) than control cells (3AO-pcDNA3), as well as more rapid activation of caspase-3 and more rapid cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP). There is a greater degree of cell apoptotic rate in the procaspase-3-expressing clones than in control cells following the treatment with cd-tk/5-FC + GCV, and apoptosis is the main cell death form. None of these effects is seen following transfection with a control vector that does not encode tk and cd (pBTdel-279). The results strongly suggest that coexpression of procaspase-3 may lead to a significant enhancement of the efficacy of cd-tk/5-FC + GCV, and this strategy would be a novel and promising approach for the treatment of ovarian cancer.