Understanding and setting up the process for health equity
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Journal Article↗
Biomedical subjects
Y Liu
Publications and source records attributed to Y Liu.
Expression of myosin heavy chain isoforms in skeletal muscle of patients with peripheral arterial occlusive disease.
PURPOSE: Peripheral arterial occlusive diseases (PAODs) not only compromise blood flow but lead to a series of subsequent metabolic and structural changes in the relevant muscles. Changes in myofibrillar proteins (eg, of myosin heavy chain [MHC] isoforms), one of the determinants of muscle structure as well as of muscular function, have not been reported in patients with PAOD and were therefore the aim of this study. METHODS: Thirteen consecutive patients with PAOD were examined (clinical stage according to Fontaine II, three patients; III, three patients, and IV, seven patients) and compared with five age-matched control patients who had been in traffic accidents. A calf muscle sample (gastrocnemius muscle) in the ischemic region was taken for MHC isoform analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver stain, and the relative content of MHC isoforms was measured. RESULTS: Compared with the control patients, there was no significant change of MHC isoforms in patients with PAOD II. In patients with PAOD III, MHC IIb decreased significantly (P <.05) although MHC IIa remained unchanged; in patients with PAOD IV, both MHC IIa and IIb decreased significantly (P <.05). Accordingly, there was a progressive increase of the relative amount of MHC I with more critical ischemia in PAOD. CONCLUSION: In patients with PAOD, the content of MHC II decreased with a higher grade of ischemia. That seems to be consistent with an increased resistance to ischemia for myosin isoforms in the order of I more than in IIa more than IIb. Whether the decrease of MHC II in patients with PAOD is related to atrophy of muscle fibers or to muscle-fiber transition must be investigated further.
Aged↗
Antisense IGF and antisense IGF-IR therapy of malignancy.
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Animals↗
Association analysis of variants in the core promoter region of angiotensinogen gene with essential hypertension in Tibetan population.
OBJECTIVE: To detect the variants in the core promoter region of angiotensinogen(AGT) gene, and to analyse the relationship between the AGT gene polymorphisms and essential hypertension in Tibetan population. METHODS: This is a case-control study consisting of 103 essential hypertensive subjects and 82 normotensive controls matched by age and sex. The variants in the AGT gene core promoter region were screened by polymerase chain reaction/single strand conformation polymorphism(PCR/SSCP) and further identified by automated sequencing. The A(-6)G polymorphism was determined in DNA extracted from leucocytes by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). RESULTS: (1) There were two different electrophoresis band patterns in PCR/SSCP analysis. PCR product direct sequencing showed that the two band patterns represented the AA, AC genotypes in the (-20) site of AGT gene respectively. The distribution of A(-20)C genotype was almost identical in essential hypertensive and normotensive groups (P>0.8). The A allele frequency was very high in both groups (control: 0.9175, hypertensive: 0.9124). (2)Distribution of genotype in the (-6) site of AGT gene was much different between the patient group and control group (P<0.005). The frequency of G allele was statistically higher in the patient group than in controls (0.374 vs 0.220, P<0.025). CONCLUSION: Both Tibetan hypertensives and normotensives have higher frequency of A allele in AGT gene (-20) site. The higher frequency of G allele in the AGT gene (-6) site in Tibetan hypertension patients suggests that this allele may be the genetic susceptibility factor in the proceeding of essential hypertension in the Tibetan population.
Angiotensinogen↗
Human papillomavirus type 16 E6 and HPV-16 E6/E7 sensitize human keratinocytes to apoptosis induced by chemotherapeutic agents: roles of p53 and caspase activation.
We and others have previously reported that human papillomavirus (HPV)-16 E6 protein expression sensitizes certain cell types to apoptosis. To confirm that this sensitization occurred in HPV's natural host cells, and to explore the mechanism(s) of sensitization, we infected human keratinocytes (HKCs) with retroviruses containing HPV-6 E6, HPV-16 E6, HPV-16 E7, or HPV-16 E6/E7. Apoptosis was monitored by DNA fragmentation gel analysis and direct observation of nuclei in cells stained with DAPI. Exposure of HKCs to etoposide, cisplatin, mitomycin C (MMC), atractyloside, and sodium butyrate, resulted in a time and dose-dependent induction of apoptosis. Expression of HPV-16 E6 and HPV-16 E6/E7, but not HPV-6 E6 or HPV-16 E7, enhanced the sensitivity of HKCs to cisplatin-, etoposide- and MMC-, but not atractyloside- or sodium butyrate-induced apoptosis. Expression of both HPV-16 E6 and HPV-16 E6/E7 decreased, but did not abolish, p53 protein levels relative to normal HKCs, and resulted in cytoplasmic localization of wt p53. P53 induction occurred in HPV-16 E6 and HPV-16 E6/E7 expressing cells after exposure to cisplatin or MMC, though never to levels found in normal untreated HKCs. P21 levels were decreased in HPV-16 E6 and HPV-16 E6/E7 expressing HKCs, and no induction of p21 was seen in these cells following exposure to cisplatin or MMC. Caspase-3 activity was found to be elevated in HPV-16 E6-expressing HKCs following exposure to cisplatin and MMC as documented by fluorometric and Western Blot analysis. Expression of wt CrmA or treatment of HPV-16 E6 expressing HKCs with the caspase-3 inhibitor DEVD.fmk prevented HPV-16 E6-induced sensitization in HKCs. These results suggest that HPV-16 E6 and HPV-16 E6/E7 expression sensitizes HKCs to apoptosis caused by cisplatin, etoposide and MMC, but not atractyloside or sodium butyrate. The data also suggest that wt p53 and caspase-3 activity are required for HPV-16 E6 and HPV-16 E6/E7-induced sensitization of HKCs to DNA damaging agents.
Apoptosis↗
Brain activation in the processing of Chinese characters and words: a functional MRI study.
Functional magnetic resonance imaging was used to identify the neural correlates of Chinese character and word reading. The Chinese stimuli were presented visually, one at a time. Subjects covertly generated a word that was semantically related to each stimulus. Three sorts of Chinese items were used: single characters having precise meanings, single characters having vague meanings, and two-character Chinese words. The results indicated that reading Chinese is characterized by extensive activity of the neural systems, with strong left lateralization of frontal (BAs 9 and 47) and temporal (BA 37) cortices and right lateralization of visual systems (BAs 17-19), parietal lobe (BA 3), and cerebellum. The location of peak activation in the left frontal regions coincided nearly completely both for vague- and precise-meaning characters as well as for two-character words, without dissociation in laterality patterns. In addition, left frontal activations were modulated by the ease of semantic retrieval. The present results constitute a challenge to the deeply ingrained belief that activations in reading single characters are right lateralized, whereas activations in reading two-character words are left lateralized.
Adult↗
Ex vivo expansion of megakaryocytic cells.
The use of platelet transfusion to ensure the recovery of thrombopoiesis in patients constitutes high-cost support. The identification and cloning of recombinant human thrombopoietin (TPO) and the development of efficient methods of purification of hematopoietic stem cells and progenitor cells have ameliorated the development of strategies of ex vivo expansion of megakaryocyte (MK) progenitor cells and mature MKs. Synergistic combinations of cytokines including TPO, interleukin (IL)-1, IL-3, IL-11, stem cell factor, and FLT-3 ligand induce the ex vivo expansion of colony-forming unit-MK progenitors and MKs from cytokine-mobilized peripheral blood cells, bone marrow, and cord blood CD34+ cells. Depending on the various culture conditions, i.e., combinations of growth factors, initial concentration of CD34+, serum or serum-free cultures, and/or oxygen tensions, the expansion-fold of MKs and their progenitor cells vary greatly. The clinical applications of the reinfusion of ex vivo-generated MK cells have been investigated successfully in cancer patients following high-dose chemotherapy. This review reports the latest information concerning ex vivo expansion of MKs and the current status of clinical trials.
Cell Culture Techniques↗
Pharmacokinetics and hepatic disposition of bis[1-(ethoxycarbonyl)propyl]5-acetylamino-2,4,6-triiodoisophthalate in rats and isolated perfused rat livers.
Bis[1-(Ethoxycarbonyl)propyl]5-acetylamino-2,4,6- triiodoisophthalate+ (NC 68183) was designed as a new computed tomography imaging agent. The purpose of this study was to determine the pharmacokinetics and metabolism of NC 68183 in conscious rats and in the isolated perfused rat liver. Animals were i.v. dosed at 69 and 690 mg of iodine/kg. Blood samples were collected at 5, 15, 30, and 60 min, and 7 days after dosing. Tissue samples (liver, kidney, and spleen) were taken at 60 min and 7 days after dosing. NC 68183 was cleared from blood in first order kinetics following an i.v. administration of 69 mg I/kg. The volume of distribution (Vss) at steady state and elimination half-life (t(1/2)) were estimated as 24 ml and 11 min. The clearance of NC 68183 from blood was changed to zero-order kinetics following administration of 690 mg/kg, and its elimination rate was 16 microg I/ml.min. The liver and spleen were the only tissues to have the nanoparticle residue at day 7 following administration. NC 68183 (75 mg of agent, 35 mg of I) was injected into the isolated perfused rat liver system. Bile flow increased from 1.0 to 1.3 microl/min/g liver following administration. The biliary excretion rate maximum was estimated as 11 microg/min/g liver. The metabolite was identified using liquid chromatography/mass spectrometry as a monocarboxylic acid product, which exclusively excreted into the bile in a soluble iodinated metabolite. Pharmacokinetics data suggested that NC 68183 primarily resides in the blood pool following an i.v. administration with a plasma half-life appropriate for blood pool imaging.
Animals↗
Analysis of human immunodeficiency virus type 1 gp160 sequences from a patient with HIV dementia: evidence for monocyte trafficking into brain.
Towards understanding the pathogenesis of HIV dementia, we molecularly cloned and sequenced human immundeficiency virus type 1 (HIV-1) gp160 genes from uncultured post-mortem tissues collected from a patient with HIV dementia. Sequences from bone marrow, lymph node, lung, and four regions of brain - the deep white matter, head of caudate, choroid plexus and meninges - were compared. Also included were gp160 sequences recovered from blood monocytes collected 5 months prior to death. Phylogenetic analyses showed that the sequences from deep white matter were more closely related to those from bone marrow, than to those from the other tissues, and moreover, were most closely related to sequences from the blood monocytes. These findings suggest trafficking of bone marrow-derived monocytes into the deep white matter during this late stage of infection. Another cluster included sequences from choroid plexus, meninges and lymph node, and interestingly, identical patterns of four or nine stop codons were shared among these tissues. These mutations appear to be the consequence of G-->A hypermutation, and could reflect independent events, or the movement of virions or infected cells, from the choroid plexus into the cerebrospinal fluid and ultimately, into the lymph node. We propose that a critical step towards the development of HIV dementia is an increase in monocyte trafficking into the brain, and that this process is either initiated and/or accelerated during late-stage infection, which could explain why dementia occurs primarily during this time.
AIDS Dementia Complex↗
[Research on the parameters of Mark V injector].
This study sought to correctly preset the parameters of Mark v injection. The emphasis was laid on the flow rate in that, it ought to be set more carefully and more accurately for ensuring success in angiography. The authors analyzed the influential factors of flow rate and the relationship between flow rate and pressure limiting and hence proposed a set of typical presetting injection parameters. Experimental results demonstrated that with the contrast media concentration around 75%, high quality images could be obtained by setting the pressure limiting within 2068-5515 kPa.
Coronary Angiography↗
Expression of human single-chain variable fragment antibody against non-structural protein 3 of hepatitis C virus antigen in e.coli.
OBJECTIVE: To express human single-chain variable fragment (ScFv) antibody against non-structural protein 3 (NS(3)) of hepatitis C virus in E.coli. METHODS: The recombinant phages were panned by NS(3) antigen which was coated in a microtiter plate. After five rounds of biopanning, 66 clones were identified specific to NS(3) antigen. E.coli host XL(1)-Blue was transformed and induced by IPTG. The specificity of ScFv was evaluated by ELISA and dot blot hybridization. RESULTS: ScFv-NS(3) DNA digestion and sequencing data showed that the ScFv gene was composed of 750bp. ELISA and dot blot hybridization demonstrated that the soluble human single-chain Fv antibody to hepatitis C virus NS(3) antigen could combine different origins of NS(3) antigen. CONCLUSION: NS(3)-ScFv antibody expressed by E.coli host XL(1)-Blue has the activity and specificity to combine different origins of HCV NS(3) antigen.
Escherichia coli↗
[The role of membrane-type 1 matrix metalloproteinase in the invasion and metastasis of hepatocellular carcinoma].
OBJECTIVE: To study the role of membrane-type 1 matrix metalloproteinase (MT(1)-MMP) in the invasion and metastasis of hepatocellular carcinoma (HCC), and find a method to judge the invasion and metastasis of HCC through MT(1)-MMP. METHODS: RT-PCR was used to study the expression of MT(1)-MMP mRNA in the HCC and in HCC nude mice model with higher metastasis potential (LCI-D20) and lower metastasis potential (LCI-35), and statistical methods were used to analyse the association between the expression of MT(1)-MMP mRNA and the pathological indexes of HCC. RESULTS: MT(1)-MMP mRNA was expressed by all the normal liver tissue (1.12 +/- 0.73), HCC (3.51 +/- 0.97), surrounding liver parenchyma (1.19 +/- 0.57), tumor embolus, and HCC nude mice model with LCI-D20, LCI-D35. The overexpression of MT(1)-MMP mRNA in HCC, embolus, LCI-D20 was related to the invasion and metastasis of HCC. The expression of MT(1)-MMP mRNA in HCC being higher than that in surrounding liver parenchyma was an important index to judge the invasion and metastasis of the HCC. CONCLUSION: MT(1)-MMP is related to the invasion and metastasis of HCC. The expression of MT(1)-MMP mRNA in HCC being higher than that in surrounding liver parenchyma could be acted as an important index to judge the invasion and metastasis of HCC.
Animals↗
Demonstration of the medullary lamellae of the human red nucleus with high-resolution gradient-echo MR imaging.
BACKGROUND AND PURPOSE: The human red nucleus is not a uniform structure. It is composed of caudally located magnocellular and rostrally located parvicellular subnuclei. In fact, the latter forms the bulk of the human red nucleus and can be subdivided histologically by two medullary lamellae into three parts. Because iron is deposited in the human red nucleus and gradient-echo sequences are more sensitive than spin-echo sequences in the detection of iron, a high-resolution gradient-echo MR sequence was used in this study to determine whether the medullary lamellae of the normal human red nucleus could be detected in vivo. METHODS: Ten healthy volunteers (seven men and three women, 27-48 years old) were examined with a high-resolution T2-weighted gradient-echo MR sequence using a 1.9-T MR imager. The scanning parameters were 60/40/15 (TR/TE/excitations) with a flip angle of 20 degrees , a pixel size of 1 x 1 mm, and a slice thickness of 5 mm. RESULTS: The medullary lamellae were depicted in all subjects in three imaging planes: coronal, oblique axial, and oblique sagittal. The signal intensity of the lamellae was consistently higher than that of other parts of the red nucleus on all images. With the lamellae, the parvicellular subnucleus of the human red nucleus can be divided into its subdivisions. CONCLUSION: High-resolution gradient-echo MR imaging is capable of depicting the medullary lamellae of the normal human red nucleus in vivo.
Adult↗
Surgical treatment for peroneal nerve palsy.
BACKGROUND: Peroneal nerve palsy is the most frequently encountered mononeuropathy of the lower extremities. Although many studies advocated spontaneous resolution of peroneal nerve palsy, more recent studies confirmed obvious improvement with surgical treatment techniques. METHODS: This study reviewed the results obtained from surgically treated peroneal nerve palsy in 14 patients who were admitted to our hospital between 1990 and 1996. The patients consisted of 12 males and two females with an average age of 31 years (range, 12-68 years). Peroneal nerve palsy in these patients was caused by direct or indirect injury, as confirmed by clinical examination and electromyography. The status of the nerve was observed for at least 4 months and explored when the nerve failed to reveal evidence of recovery. The nerve was decompressed, repaired or reconstructed by nerve grafting, according to the status of the injury. Weber scales were used to assess the peripheral neuropathies preoperatively and postoperatively. RESULTS: At a mean of 23 months (range, 11-61 months), nerve palsy scores improved from an average of 5 points to 3.14 points. Despite the small number of patients, our results indicated that the time interval between onset of injury and date of surgical treatment (p < 0.05) was the most significant factor to influence the prognosis of surgery. Results obtained from surgery were not related to the method of treatment, length of nerve graft or mechanism of injury. CONCLUSIONS: Because peroneal nerve palsy does not always resolve spontaneously, this study favored early surgical exploration for peroneal nerve dysfunction, based on at least 4 months of follow-up.
Adolescent↗
Homeobox genes in the genetic control of eye development.
Vertebrate eye formation is a complex process which involves early specification of the prospective eye territory, induction events, patterning along the polarity axes and regional specification, to bring about the proper morphogenetic movements, cell proliferation, cell differentiation and neural connections allowing visual function. The molecular machinery underlying such complex developmental events is presently under an intense research scrutiny and many associated genetic factors have been isolated and characterized. These studies produced striking knowledge in the field, especially with respect to uncovering the role of key genes and their possible evolutionary conservation. Presently, a major task is to define the complex interactions connecting the multiplicity of molecular players that regulate eye development. We recently identified two homeobox genes, Xrx1 and Xvax2, and studied their function by using the Xenopus embryo as a developmental model system. Xrx1 and Xvax2 control key aspects of eye development. In particular, Xrx1 appears to play a role in the early specification of anterior neural regions fated to give rise to retina and forebrain structures, and in promoting cell proliferation within these territories. On the other hand, Xvax2 is involved in regulating the eye proximo-distal and/or dorsoventral polarity, and the morphogenetic movements taking place during formation of the optic stalk and cup. Here we review the experimental results addressing the roles of Xrx1 and Xvax2 and their vertebrate orthologues, and discuss their relationship with other molecules also playing a related function in eye development.
Animals↗
Artificial trachea and long term follow-up in carinal reconstruction in dogs.
We have already reported successful carinal reconstruction of the trachea with an observation period of 1 - 2 years. In this study, we evaluate the long-term safety and efficacy of the reconstruction after 5-years of follow-up. The Y-shaped Marlex mesh tube was reinforced with a polypropylene spiral and coated with atelocollagen made from porcine skin. The prosthesis was 60 mm long with an outer diameter of 18 mm. Replacement of the tracheobronchial bifurcation was preformed through a right thoracotomy in a beagle dog. Bronchoscopical examination and sampling of the tracheal epithelium was performed periodically to check the function of cilia. The implanted prothesis was promptly infiltrated by the surrounding connective tissue and completely incorporated by the host trachea and bronchus. Bronchoscopically, sufficient epithelization was confirmed from the upper to the lower site of anastomosis. After 5 years neither stenosis nor dehiscence was observed. In spite of there being mesh-exposure at the luminal surface, the dog had no clinical symptoms until sacrifice for pathological examination. The bent frequency of the cilia was maintained within the normal range, indicating functional recovery of the regenerating airway. Our tracheal prosthesis is promising for clinical repair of the tracheobronchial bifurcation.
Animals↗
[Analyses on the association of CA-repeat polymorphism and A1166-->C variant in the 3'-flanking region of AT(1)R gene with essential hypertension in Tibetans].
OBJECTIVE: To investigate whether CA-repeat polymorphism and A1166 --> C variant in the 3n-flanking region of AT(1)R gene are in association with the genetic susceptibily to essential hypertension (EH) in Tibetans. METHODS: A case-control study was carried out. Sibpair analysis and family linkage analysis were conducted. The CA-repeat polymorphism of AT &(1) R gene was identified by polymerase chain reaction(PCR) with fluorescence labeled dCTP as substrate and by semi-automatic sequence technology. The A1166 -->C variant was detected by PCR-RFLP. RESULTS: Association of AT&(1)R gene locus with EH was confirmed through the case-control study in well-characterized group of 113 Tibetan EH patients and 131 normotensives(chi(2)=26.44, P<0.001). A closer examination of this gene locus found 11 alleles from Tibetan population; allele A7 (138 bp) was more frequent in both the patients and the controls. Allele A8(140 bp) was in strong positive association with genetic susceptibility to EH in Tibetans. Frequency of allele A8 was 20.5% in EH and 7.3% in normotensives. The difference of allele frequencies between the groups was significant (chi(2)=9.64, P=0.002, OR=3.46, 95% CI 1.44-8.51). Affected sibpair analysis showed chi(2)=3.85, P=0.025; family linkage analysis gave Lod score of 0.80. No association between A1166 --> C variant in AT(1)R gene and EH in Tibetans was observed (P>0.05). CONCLUSION: The result suggests that CA-repeat polymorphism of AT(1)R gene be in association with EH in Tibetans, which implicates that AT(1)R gene may be in linkage disequilibrium with the causative genes of EH.
Adult↗
[Is Gly460Trp variant of alpha-adducin associated with essential hypertension in the Hans of Chinese population].
OBJECTIVE: To determine whether the variant of adducin alpha subunit (alpha-adducin) is in association with essential hypertension in the Hans of Chinese population. METHODS: One hundred and eighty-three patients with essential hypertension and 129 normotensive subjects were included in this study. Genomic DNA was isolated from 3 ml of whole blood. Polymerase chain reaction, single-strand conformational polymorphism and DNA sequencing analysis techniques were used to detect the variant in the exon 10 of alpha-adducin gene. The clinical data of height, weight and blood pressure were also measured in all subjects. RESULTS: A G-->T substitution at nucleotide 614 in exon 10 of alpha-adducin gene which resulted in the Gly460Trp variant was found in the Hans. The distribution of Gly/Gly, Gly/Trp and Trp/Trp genotypes was coincident with Hardy-Weinberg equilibrium and there were no statistical differences in the three genotypes and Trp allele frequencies between hypertensive and normotensive subjects (P>0.05). The variant of alpha-adducin genotypes was not associated with any significant differences in age, body mass index and blood pressure. CONCLUSION: A G-->T substitution at nucleotide 614 in exon 10 of alpha-adducin gene is found, but there is lack of the association between the variant of alpha-adducin gene and essential hypertension in the Hans of Chinese population.
Adult↗