[Sex difference of blood cadmium concentration in neonates].
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Adult↗
Biomedical subjects
X Kong
Publications and source records attributed to X Kong.
Structure of the E2 DNA-binding domain from human papillomavirus serotype 31 at 2.4 A.
The papillomaviruses are a family of small double-stranded DNA viruses which exclusively infect epithelial cells and stimulate the proliferation of those cells. A key protein within the papillomavirus life-cycle is known as the E2 (Early 2) protein and is responsible for regulating viral transcription from all viral promoters as well as for replication of the papillomavirus genome in tandem with another protein known as E1. The E2 protein itself consists of three functional domains: an N-terminal trans-activation domain, a proline-rich linker, and a C-terminal DNA-binding domain. The first crystal structure of the human papillomavirus, serotype 31 (HPV-31), E2 DNA-binding domain has been determined at 2.4 A resolution. The HPV DNA-binding domain monomer consists of two beta-alpha-beta repeats of approximately equal length and is arranged as to have an anti-parallel beta-sheet flanked by the two alpha-helices. The monomers form the functional in vivo dimer by association of the beta-sheets of each monomer so as to form an eight-stranded anti-parallel beta-barrel at the center of the dimer, with the alpha-helices lining the outside of the barrel. The overall structure of HVP-31 E2 DNA-binding domain is similar to both the bovine papillomavirus E2-binding domain and the Epstein-Barr nuclear antigen-1 DNA-binding domain.
Amino Acid Sequence↗
Nucleotide sequence homology to bovine viral diarrhea virus 2 (BVDV 2) in the 5' untranslated region of BVDVs from cattle with mucosal disease or persistent infection in Japan.
Cytopathogenic and non-cytopathogenic bovine viral diarrhea viruses (BVDVs) were isolated from cattle with mucosal disease or persistent infection in Japan. These isolates were compared for antigenic properties by cross-neutralization tests with Japanese reference strains of BVDV belonging to classical type 1. Significantly low cross-reactivity to reference strains was noted, indicating the viruses to possibly represent a new serotype in Japan. Thus, to determine the genotype of the isolates, nucleotide sequences of the 5' untranslated region were determined and compared with those of previously reported BVDV 1 and 2. The isolates were clearly shown to belong to BVDV 2, not to BVDV 1.
Animals↗
Gradient- and sensitivity-enhanced heteronuclear multiple-quantum correlation spectroscopy.
A gradient- and sensitivity-enhanced HMQC experiment has been developed. The sensitivity of the experiment is increased by factors of the square root of 2 and 2 over the conventional and gradient-enhanced HMQC experiments, respectively. This improvement is achieved by retaining both the x and the y magnetization components in the indirectly detected dimension. This experiment will be particularly useful in NMR studies of large biomolecules as the relaxation time of the multiple-quantum coherence is much longer than that of the single-quantum coherence in the slow motion limit.
Calmodulin↗
Identification of conserved amino acids in murine B7-1IgV domain critical for CTLA4/CD28:B7 interaction by site-directed mutagenesis: a novel structural model of the binding site.
The B7: CD28/CTLA4 interaction plays a major role in T cell responses. Immune intervention targeted at this interaction has demonstrated a vast potential in enhancing tumor immunity and blocking autoimmunity and transplant rejection. However, the structural basis for this interaction is unclear. While we and others have performed site-directed mutagenesis to define amino acids involved in binding CD28 and CTLA4, these residues are localized in different regions, and it is unlikely for all of them to be directly involved. In addition, the effect of the mutations on the overall conformation of B7 has not been systematically evaluated. In this study, we have carried out site-directed mutagenesis to define the amino acids within B7-1 IgV-like domain which participate B7:CD28/CTLA4 interaction. Four anti-B7-1 mAbs that recognize three independent antigenic epitopes on B7-1 were used to monitor the effect of mutations on the overall conformation of B7-1. Of the five mutations in the IgV domain that we have produced, D113 > A appears to interfere with cell surface expression and/or overall conformation of B7-1. while four others do not significantly affect the overall conformation and cell surface expression of B7-1. Among them, G115 > A and Y91 > A eliminated B7-1 binding to both CD28Ig and CTLA4Ig; our previously reported mutants L109 > A and W88 > A selectively affect the B7-1 binding to either CD28Ig or CTLA4Ig. Structural modeling of B7-1 based on the structure of immunoglobulin revealed that these four and other previously identified critical amino acids in both IgV- and IgC-like domains can form a localized structure.
Abatacept↗
[Effects of excessive zinc in fodder on brain development and abilities of learning and memory and their mechanisms in young rats].
OBJECTIVE: To study the effects of excessive zinc in fodder on brain development and abilities of learning and memory and to explore their mechanisms in young rats. METHODS: Animal models with excessive zinc were established in young Wistar rats during their lactation period. Rats were divided into five groups, Groups ZE1 and ZE2 were fed with excessive zinc, Group AL was freely fed with Flanagna fomula fodder added with zinc sulfate, Group PF was matched pair of Group ZE2 and Group ZE2R was fed with fodder same as Group AL after weaning. Ultrastructure was observed with electron microscopy, their free amino acids, nitrous oxide and somatostatin were measured with neurobiochemical methods, and their abilities to learn and memorize were examined. RESULTS: Weight of cerebrum and hippocampus in the rats reduced and zinc levels in their serum and hippocampus raised with the increase of zinc content in their fodder. Acute avoidance response (AAR) and movement in the young rats fed with excessive zinc in Groups ZE1 and ZE2 were obviously lower than in Groups AL and PF. AAR was significantly lower in Group ZE2R than that in Groups AL and PF, but significantly higher than that in Group ZE2. There was no significant difference in AAR between Groups PF and AL, but more movement was observed in them. Nitrous oxide in hippocampus raised and somatostatin decreased in Group ZE2, and total amount of excitatory and inhibitory amino acids in brain tissues raised, especially for glutamic acid. Neurones, gliocytes and organella in the CA1 region of hippocampus in the Group ZE2 showed degeneration, necrosis and rupture of synaptic bolus to varied extent. CONCLUSION: Excessive zinc in fodder could significantly affect brain development and functions in young rats with multiple mechanisms.
Animals↗
TCM treatment of chemotherapy-induced fever in leukemia patients.
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Adolescent↗
[The study of radioresistance of BHRF1 gene].
In order to learn relationship between the expression of BHRF1 gene and radiative sensitivity of cells of nasopharyngeal carcinoma. High BHRF1 expressive vector was set up and transfected in the cell line of nasopharyngeal carcinoma, CNE2. Then the cells were radiated to test its ability of clone formation in nude mice. The results showed that the tumors formed by BHRF1-CNE2 cells were lighter before radiation and weighter after radiation (P < 0.01), and apoptotic index of BHRF1-CHE2 was less than control groups (P < 0.01). So, it suggests that the BHRF1 expression could prevent apoptosis by enhancing the resistibility of the tumor cells to radiation.
Animals↗
[Study of the etiologic pathogenesis of multiple myeloma].
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Humans↗
[Effects of ligustrazine on myocardium and coronary artery].
OBJECTIVE: To study the effects of ligustrazine on mechanical electricity in guinea pig ventricular papillary muscles and on contraction of pig coronary artery. METHOD: Standard glass microelectrode technology; electrophysiological method; and blood vessel perfusion were used. RESULT: 1. ligustrazine(3-100 mumol/L) suppressed the action potential duration (APD) and the force of contraction (FC) of the fast action potentials (FAP), as well as the action potential amplitude (APA), APD, FC and the maximal upstroke velocity(Vmax) of the slow action potentials (SAP). 2. ligustrazine (3.0 mmol/L) induced SAP and contraction, but failed in beta-adrenoreceptor blocked muscles. Elevation of[Ca2+]o increased the action potential amplitude (APA). 3. ligustrazine(10(-5)-5 x 10(-3) mol/L) decreased the contractile response to high KCl in pig coronary artery. CONCLUSION: Ligustrazine might affect the inward current of myocardial cells through beta-adrenoreceptor, and the diastolizing effect of ligustrazine on coronary artery might have nothing to do with the exciting beta-adrenoreceptor.
Action Potentials↗
[Multilocular cyst of kidney].
OBJECTIVE: Multilocular cyst of kidney is a rare, unique and characteristic renal lesion with benign biologic behavior. We report a case of the disease. METHODS: It was confirmed by operation and pathology. RESULTS: It is difficult to distinguish radiologically multilocular cyst of kidney from cystic renal carcinoma and wilms tumor. CONCLUSION: Surgical intervention is the only effective treatment and method to differentiate multilocular cyst of kidney from a malignant lesion of the kidney.
Adult↗
[Primary epididymal tumors].
OBJECTIVE: To improve the diagnosis of primary epididymal tumors. METHOD: In 23 primary epididymal tumors (22 benign and 1 malignant), 14 were adenomatoid tumors, 6 were leiomyomas, 1 was multiple fibrous pseudomonas and 1 was sclerosing hemangioma. Epididymal adenocarcinoma was seen in a 57-year-old man. RESULT: Epididymal tumors might be easily misdiagnosed as epididymal tuberculosis, chronic epididymis and spermatocele. Apart from certain benign clinical characteristics, benign epididymal tumors could be diagnosed by B-ultrasonography and aspiration biopsy. Most malignant tumors of epididymis presented as rapidly growing scrotal masses and cured by the removal of tumors or the whole epididymis of the same side. 19 of 22 cases were free from recurrence. CONCLUSION: Malignant epididymal tumors should be treated as malignant tumors of testis and their prognosis is extremely poor.
Adenocarcinoma↗
[Low semi-cystectomy in treating trigone of bladder neck carcinoma].
OBJECTIVE: To resect the tumor in trigone and bladder neck and remain urination function. METHOD: A new procedure low segmental-cystectomy which includes resection of the trigone of bladder, prostate, seminal vesicles, extremity of ureter, was performed on 8 patients aged 28 to 57 years. RESULT: The patients were followed up for 6 months to 3 years. No recurrent tumor and metastasis were found, and urination function was normal. CONCLUSION: This procedure is superior to Bricker's operation, Kock pouch bladder and ileal neo-bladder. The patients enjoy good life quality after operation.
Adult↗
[Apoptosis of renal cell carcinoma and apoptotic related genes bcl-2 and bax].
OBJECTIVE: To explore the mechanism of renal cell carcinoma (RCC). METHOD: We detected the apoptotic status and the expression of apoptotic related gene bcl-2 and bax protein in 48 cases of RCC with TdT-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistochemistry methods. RESULT: 22 cases showed low expression of bcl-2 protein with an average apoptotic index (AI) of 1.35 and 26 cases had high expression of bcl-2 with an AI of 1.04 (P < 0.05). 34 cases showed low expression of bax protein with average AI of 1.03 and 14 cases had high expression of bax protein with an average AI of 1.63 (P < 0.01). The stronger bcl-2 expression, the weaker bax expression and the less number of apoptotic cells. CONCLUSION: both bcl-2 and bax take part in the occurrence and progression of RCC.
Adolescent↗
[Expression and significance of Fas/APO-1 and bcl-2 protein in renal cell carcinoma].
OBJECTIVE: To investigate the role of Fas/APO-1 and bcl-2 in occurrence and progression of renal cell carcinoma. METHOD: Immunohistochemistry method was used to detect the expression of Fas/APO-1 and bcl-2 protein in 35 cases of renal cell carcinoma tissues and 26 cases of normal renal tissues. RESULT: The expression rate of Fas/APO-1 protein in renal cell carcinoma tissues was 57.14%, significantly lower than that in normal renal tissues (84.62%) (P < 0.05), and the intensity of expression was also lower. The expression rate of bcl-2 protein reached 80.00%, much higher than that in normal renal tissues (53.85%) (P < 0.05). CONCLUSION: Both Fas/APO-1 and bcl-2 take part in the occurrence and progression of renal cell carcinoma.
Adult↗
Regulation of classic and alternative bile acid synthesis in hypercholesterolemic rabbits: effects of cholesterol feeding and bile acid depletion.
The effect of cholesterol feeding (3 g/day) on bile acid synthesis was examined in 10 New Zealand white rabbits (NZW), 8 Watanabe heterozygous and 10 homozygous rabbits with partial and complete deficiencies of LDL receptors. After 10 days of cholesterol feeding, bile fistulas were constructed and bile acid pool sizes were measured. Cholesterol feeding increased plasma and hepatic cholesterol levels in all rabbit groups. Baseline bile acid pool sizes were smaller (P < 0.01) in heterozygotes (139 +/- 3 mg) and homozygotes (124 +/- 30 mg) than NZW rabbits (254 +/- 44 mg). After feeding cholesterol, bile acid pool sizes doubled with increased cholic acid synthesis in NZW and, to a lesser extent, in Watanabe heterozygous rabbits but not in homozygotes. Baseline cholesterol 7alpha-hydroxylase activity in NZW and heterozygotes declined 69% and 53% (P < 0.001), respectively, after cholesterol feeding. Sterol 27-hydroxylase activity reflecting alternative bile acid synthesis increased 66% (P < 0.01) in NZW and 37% in Watanabe heterozygotes but not in homozygotes after feeding cholesterol. Bile fistula drainage stimulated cholesterol 7alpha-hydroxylase activity but not sterol 27-hydroxylase activity in all three rabbit groups. These results demonstrated that dietary cholesterol increased hepatic sterol 27-hydroxylase activity and alternative bile acid synthesis to expand the bile acid pool and inhibited cholesterol 7alpha-hydroxylase in NZW and in Watanabe heterozygous rabbits but not in homozygotes with absent hepatic LDL receptor function. Thus, in rabbits, sterol 27-hydroxylase is up-regulated by the increased hepatic cholesterol that enters the liver via LDL receptors whereas cholesterol 7alpha-hydroxylase is controlled by the circulating hepatic bile acid flux.
Animals↗
Antigenic and genetic comparisons of Japanese and Australian Simbu serogroup viruses: evidence for the recovery of natural virus reassortants.
The antigenicity and RNA genome structures of five Simbu serogroup bunyaviruses isolated in Japan and Australia were analyzed using monoclonal antibodies (Mabs) raised to Akabane (AKA) virus and oligonucleotide fingerprinting. The virion surface glycoprotein (G1) and the nucleocapsid (N) protein of heterologous viruses showed no reactivity to the Mabs, while the AKA-derived anti-G1 Mab (2F1) reacted with Peaton virus and all three AKA anti-N Mabs reacted with Tinaroo (TIN) virus at almost the same antibody titers as the homologous virus. Oligonucleotide fingerprinting analyses indicated that the three RNA species of all the viruses were unique and distinguishable. However, AKA and TIN viruses exhibited very similar S RNA oligonucleotide fingerprints, while the L and M RNA fingerprints were quite different. The S RNA sequence of TIN virus has been determined and compared with that of AKA and Aino viruses. The results revealed 95.1% S sequence homology between the AKA and TIN viruses. The antigenic and genetic comparisons of AKA and TIN viruses suggest that the two viruses may represent naturally occurring reassortant viruses.
Amino Acid Sequence↗
Complete regression of established murine hepatocellular carcinoma by in vivo tumor necrosis factor alpha gene transfer.
BACKGROUND & AIMS: Although tumor necrosis factor (TNF)-alpha possesses a potent antitumor activity, systemic administration of TNF-alpha causes severe side effects. To circumvent this, the efficacy of tumor cell-targeted TNF-alpha gene therapy was investigated. METHODS: Murine hepatocellular carcinoma (HCC) cells were infected with MNSM-Alb e/p-TNF-alpha retroviruses carrying the murine TNF-alpha gene under the transcriptional control of the murine albumin gene promoter, and antitumor effects induced by TNF-alpha gene transfer were examined in vitro and in vivo. RESULTS: Although MNSM-Alb e/p-TNF-alpha retrovirally infected HCC cells showed the same in vitro cell growth as parental HCC cells, they lost their tumorigenicity when implanted in syngeneic mice and induced tumor immunity against parental HCCs. The retrovirally infected HCC cells also significantly inhibited the tumorigenicity of previously implanted parental HCCs. Furthermore, intratumoral administration of MNSM-Alb e/p-TNF-alpha retroviruses showed the antitumor effect against established HCCs, resulting in significantly prolonged survival periods. Most importantly, intratumoral implantation of MNSM-Alb e/p-TNF-alpha retroviral-producing cells completely abrogated established HCCs in mice. CONCLUSIONS: These results indicate the potential efficacy of transferring the TNF-alpha gene via retroviral vectors directly into tumors for gene therapy against HCCs.
Animals↗