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L X Cao

Publications and source records attributed to L X Cao.

17 recordsLinked to original sources
PubMed2001

X-ray standing wave analysis of the effect of isotopic composition on the lattice constants of Si and Ge.

The x-ray standing wave (XSW) technique is used to measure the isotopic mass dependence of the lattice constants of Si and Ge. Backreflection allows substrates of moderate crystallinity to be used while high order reflection yields high accuracy. The XSW, generated by the substrate, serves as a reference for the lattice planes of an epilayer of different isotopic composition. Employing XSW and photoemission, the position of the surface planes is determined from which the lattice constant difference Deltaa is calculated. Scaled to DeltaM = 1 amu we find (Deltaa/a) of -0.36x10(-5) and -0.88x10(-5) for Ge and -1.8x10(-5) and -3.0x10(-5) for Si at 300 and 30 K, respectively.

Journal Article↗
PubMed1999

Human factor VIII can be packaged and functionally expressed in an adeno-associated virus background: applicability to haemophilia A gene therapy.

Adeno-associated virus (AAV) is a single-stranded DNA parvovirus displaying several attractive features applicable to haemophilia A gene therapy, including nonpathogenicity and potential for long-term transgene expression from either integrated or episomal forms. We have generated and characterized two B-domain-deleted (BDD) fVIII mutants, deleted in residues Phe756 to Ile1679 (fVIIIdelta756-1679) or Thr761 to Asn1639 (fVIIIdelta761-1639). [35S]metabolic labelling experiments and immunoprecipitation demonstrated intact BDD-fVIII of the predicted size in both lysates and supernatants (Mr approximately 155 kD for fVIIIdelta756-1679 and Mr approximately 160 kD for fVIIIdelta761-1639) after transient transfection into COS-1 cells. Functional fVIII quantification appeared maximal using fVIIIdelta761-1639, as evaluated by Coatest and clotting assay (98+/-20mU/ml/1x10(6) cells and 118+/-29 mU/ml/1x10(6) respectively, collection period 48 h). To bypass potential size limitations of rAAV/fVIII vectors, we expressed fVIIIdelta761-1639 using a minimal human 243 bp cellular small nuclear RNA (pHU1-1) promoter, and demonstrated VIII activity approximately 30% of that seen using CMV promoter. This BDD-fVIII (rAAV(pHU1-1) fVIIIdelta761-1639) can be efficiently encapsidated into rAAV (107% of wild type), as demonstrated by replication centre and DNAase sensitivity assays. A concentrated recombinant viral stock resulted in readily detectable factor VIII expression in COS-1 cells using a maximally-achievable MOI approximately 35 (Coatest 15 mU/ml; clotting assay 25+/-20 mU/ml/1x10(6) cells). These data provide the first evidence that rAAV is an adaptable virus for fVIII delivery, and given the recent progress using this virus for factor IX delivery in vivo, provide a new approach towards definitive treatment of haemophilia A.

Cells, Cultured↗
PubMed1999

Asian Pacific cooperative study of allogeneic bone marrow transplantation.

The first cooperative study of the Asian Pacific bone marrow transplantation group included 75 patients with early leukemia who received human leukocyte antigen-matched sibling bone marrow transplants and were randomized into granulocyte colony-stimulating factor and control groups. The selected patients were registered from 10 centers in six countries and areas within Asia (Beijing, Taipei, Hong Kong, Japan, Korea, and Malaysia). The incidence of grades II-IV acute graft-vs.-host disease was 22.2%, and the 2-year survival rate was 62.7%. The period of protective isolation (27.1-66.7 days), period of hospitalization (38.6-130.5 days), and medical costs for 4 months (US $10,300-US $80,803) varied considerably. Good cooperation, i.e., low rate of protocol violation or rapid and precise presentation of case reports, was obtained.

Bone Marrow Transplantation↗
PubMed1998

Intracerebroventricularly injected L-arginine-induced vasopressin release is mediated by cGMP in rats.

AIM: To study the possible role of cGMP in the effect of L-arginine-induced arginine-vasopressin (AVP) release. METHODS: In anesthetized rats, saline, L-arginine, 8-Br-cGMP, L-arginine + methylene blue (an inhibitor of guanylyl cyclase) were injected intracerebroventricularly (icv) and the plasma vasopressin level was detected with radioimmunoassay. RESULTS: Both 8-Br-cGMP 2.53 g.L-1 and L-arginine 100 g.L-1 increased plasma AVP level [from (2.6 +/- 0.3) to (6.6 +/- 0.4) ng.L-1, and from (3.2 +/- 0.5) to (5.8 +/- 1.4) ng.L-1, respectively; P < 0.01] 5 min after the icv injection; methylene blue (3.74 g.L-1) + L-arginine (100 g.L-1) did not change plasma AVP level. CONCLUSION: cGMP was a mediator of the effect of L-arginine-induced AVP release.

Animals↗
PubMed1997

Implication of a new molecule IK in CD34+ hematopoietic progenitor cell proliferation and differentiation.

HLA-DR is one of the markers associated with hematopoietic cell differentiation, since expression of this molecule is modulated throughout hematopoiesis. We have previously described and cloned the gene encoding factor IK, which inhibits both interferon gamma (IFN-gamma)-induced and constitutive HLA-DR expression. The current study demonstrates that IK gene transcripts are present in CD34+ cells purified from human umbilical cord blood. IK expression increased and was therefore inversely correlated with the gradual loss of HLA-DR during growth factor-induced CD34+ cell proliferation and differentiation. To study the possible role of IK in hematopoiesis, antisense probes were used. IK expression was specifically inhibited by an antisense oligodeoxynucleotide containing two phosphorothioate internucleotide linkages at each of the 3' and 5' ends and corresponding to the initiation site of IK mRNA. A control oligonucleotide was also tested in parallel. A specific decrease of IK transcripts was correlated with an increase of HLA-DR antigen expression level. In colony-forming assays, IK antisense oligonucleotide inhibited colony formation by multilineage early erythroid and granulomonocytic CD34+ progenitors. The mean colony size was decreased 70% by IK antisense oligonucleotide in comparison to controls. These results provide evidence that the IK molecule participates in the regulation of HLA-DR expression on hematopoietic cells and plays a role in growth factor-dependent CD34+ cell proliferation and differentiation by modulating HLA-DR expression.

Antigens, CD34↗
PubMed1994

[Cytokine production by MTSC 4 cells, an established mouse thymic dendritic cell line].

The cytokine production by MTSC 4 cells, a murine thymic dendritic cell line established in our laboratory, has been investigated. Without exogenous stimulation, the MTSC 4 cells constitutively produce multiple types of cytokines, including IL-1, IL-6, IL-7, CSF, IFN and Chemotactic factor (CF). Of which, IL-6 and IFN were abundant: IL-1 and Chemokine, moderate: IL-7 and CSF at low level. MTSC4 cells could not produce detectable either IL-3 of TNF alpha. The establishment of MTSC 4 may be useful in the analysis of the mechanism of thymus selection, and in the study of the network regulation of autocrined cytokines.

Animals↗
PubMed1993

[Characterization of morphologic, cytochemical and immunological features in myeloperoxidase negative acute myeloid leukaemia].

Ten cases of acute myeloperoxidase-negative myeloid leukaemia (AML) were reported. They had no typical mopholocid negative for lymphocic features and were negative antigens. However 5 cases were positive for NSE/NaF stain. 9 of the 10 cases expressed more than one myeloid antigens. The authors are of the opinion that it is very difficult to diagnose myeloperoxidase-negative AML and combination of cytochemical and immunological techniques is recommended in this respect.

Adolescent↗
PubMed1992

HSV-1-inducible proteins bind to NF-kappa B-like sites in the HSV-1 genome.

Several putative NF-kappa B-binding sites in the ICP0 and Vmw65 herpes simplex virus type-1 (HSV-1) genes have been identified. Oligonucleotides encoding some of these sites bind specifically to purified NF-kappa B protein and an NF-kappa B-like protein in nuclear extracts of phorbol ester- or cycloheximide-induced human embryonic lung (HEL) cells. HSV-1 infection of HEL cells induced a nuclear factor that binds specifically to kappa B sites in the ICP0 and Vmw65 gene regions and comigrates with complexes formed by purified NF-kappa B. The HSV-1-inducible nuclear factor bound to the authentic immunoglobulin (Ig) kappa B site. Transient expression of chloramphenicol acetyltransferase (CAT) plasmids containing two copies of the Ig kappa B site upstream of the c-fos promoter (kappa B2-CAT) showed activity in HEL cells. HSV-1 infection of kappa B2-CAT-transfected HEL cells, however, induced a dramatic increase in CAT activity; mutation in the NF-kappa B-binding site of kappa B2-CAT abolished the inducibility of CAT gene expression. Our results demonstrate that the HSV-1 ICP0 and Vmw65 gene regions contain binding sites for NF-kappa B, and that HSV-1-inducible proteins bind to NF-kappa B-like sites in the HSV-1 genome.

Base Sequence↗
PubMed1991

[Allogeneic bone marrow transplantation in the treatment of leukemia: analysis of 10 cases].

Ten leukemic patients were treated with allogeneic bone marrow transplantation (BMT). The diagnosis were ANLL in 6 cases, CML in 3 and ALL in one. Pretransplant immuno suppressive measures including total body irradiation cyclophosphamide and daunorubicin were given. All the patients were infused with health stem cell preparation, so that the hemopoietic function was restored. Graft versus-host disease of grade I to II was present in 5 of the patients. Leukemia recurred 76 days after BMT in one patient who received the procedure during a relapse of the disease, while in the remaining 9 patients disease-free survival from 1 to 23 months has been observed.

Adolescent↗
PubMed1991

[Effect of shen-qian gu-jing granule on fibrin degradation products in serum and menstrual fluid of patients with menorrhagia].

Shen-Qian Gu-Jing granule was used in the treatment of the menorrhagia in 72 cases including idiopathic menorrhagia 28, uterine myoma 29, endometriosis 7, intrauterine device 5, postpartum and post induced abortion 3 cases. The amount of menstrual blood loss (MBL) and the fibrin degradation products (FDP) level in menstrual fluid and peripheral blood were measured before and after treatment. 87.5% of all cases showed a significant decrease in MBL (P less than 0.05). The local FDP level significantly decreased parallel to effectiveness of MBL. The results suggested that the function of this Chinese herbs complex in menorrhagia was related to the regulation of FDP level.

Adult↗
PubMed1989

[Some difficult problems in the classification of acute leukemia].

The authors presented 5 cases of ANLL and 6 cases of ALL according to FAB classification and further classified them with leukemic cell morphology, cytochemistry and immunophenotyping. Five cases of them belonged to low grade peroxidase ANLL (LP-ANLL), 4 to hybrid acute leukemia (HAL) and 2 to acute undifferentiated leukemia (AUL). The importance of immunophenotyping of leukemic cells in classification of acute leukemia was emphasized and the criteria for diagnosis of LP-ANLL, HAL and AUL discussed. The authors are of the opinion that the diagnosis of these three kinds of acute leukemia is difficult and the prognosis is serious.

Acute Disease↗
PubMed1984

Semisynthetic deoxyharringtonine for treating leukemia in mice and humans.

The effects of two varieties of semisynthetic deoxyharringtonine on the tumor mass and survival time of mice with murine leukemia were evaluated. Compared to untreated control mice, the survival time of those with murine leukemia increased by 146% (L7212) and 68% (L615) after treatment. The LD50 for deoxyharringtonine variants DH4.8 and DH was determined to be 322 +/- 9 mg/kg and 71 +/- 1 mg/kg, respectively. Seventeen patients were then treated with either DH or DH4.8; 11% achieved complete remission, 23% achieved partial remission, and an additional 35% had markedly lower leukocyte levels after treatment. Side effects were minimal. It was concluded that deoxyharringtonine is an effective anti-leukemic agent.

Adult↗
PubMedDate not supplied

Multiple types of cytokines constitutively produced by an established murine thymic epithelial cell line.

An untransformed murine thymic epithelial cell line (MTEC1) has been established. Without exogenous stimulation, the MTEC1 cells constitutively produced multiple types of cytokines, including IL-1, IL-6, IL-7, GM-CSF and chemotactic factor(s). Of which, IL-6, GM-CSF and chemotactic factor(s) were abundant; IL-1, moderate; and IL-7 at low level. MTEC1 cells neither produced detectable IL-3 nor TNF alpha. Thus, the MTEC1 cells may be useful not only in the evaluation of the signals required for thymic selection in vitro, but also useful in the analysis of the endogenous regulation of the autocrine cytokine production cascade.

Animals↗