MICA intron 1 sequences of conserved extended HLA haplotypes: implications for sequencing-based typing

The human major histocompatibility complex (MHC) class I chain-related gene A (MICA) has a high degree of genetic diversity. Several methods have been used in MICA typing. Recent studies reported different results for the same reference cell lines typed by different methods. By searching the GenBank, we found an indel polymorphism in MICA intron 1 corresponding to the area where one of the sequencing-based typing primers used by others is located. We investigated this polymorphism in 43 reference samples by primer cycle sequencing. This approach revealed three haplotype-specific patterns of polymorphisms in intron 1. This study provided evidence that one of the primers commonly used in MICA typing may fail to amplify both alleles in certain heterozygous combinations. Our data showed a correlation between the three patterns in MICA intron 1 and exon 5 short tandem repeat (STR) alleles. Being neutral ones, the intron 1 and STR polymorphisms appeared to mark the ancestral lineages better than the coding region polymorphisms.

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Rho0 production and possible modification in Au+Au and p+p collisions at square root [sNN] = 200 GeV

We report results on rho(770)(0)-->pi(+)pi(-) production at midrapidity in p+p and peripheral Au+Au collisions at sqrt[s(NN)]=200 GeV. This is the first direct measurement of rho(770)(0)-->pi(+)pi(-) in heavy-ion collisions. The measured rho(0) peak in the invariant mass distribution is shifted by approximately 40 MeV/c(2) in minimum bias p+p interactions and approximately 70 MeV/c(2) in peripheral Au+Au collisions. The rho(0) mass shift is dependent on transverse momentum and multiplicity. The modification of the rho(0) meson mass, width, and shape due to phase space and dynamical effects are discussed.

Physiological and morphological effects of alendronate on rabbit esophageal epithelium

Alendronate, an aminobisphosphonate, produces as a side effect a topical (pill induced) esophagitis. To gain insight into this phenomenon, we assessed the effects of luminal alendronate on both esophageal epithelial structure and function. Sections of rabbit esophageal epithelium were exposed to luminal alendronate at neutral or acidic pH while mounted in Ussing chambers to monitor transmural electrical potential difference (PD), short-circuit current (I(sc)), and resistance (R). Morphological changes were sought by light microscopy in hematoxylin and eosin-stained sections. Impedance analysis was used for localization of alendronate-induced effects on ion transport. Luminal, but not serosal, alendronate (pH 6.9-7.2), increased PD and I(sc) in a dose- and time-dependent manner, with little change in R and mild edema of surface cell layers. The changes in I(sc) (and PD) were reversible with drug washout and could be prevented either by inhibition of Na,K-ATPase activity with serosal ouabain or by inhibition of apical Na channels with luminal acidification to pH 2.0 with HCl. An effect on apical Na channel activity was also supported by impedance analysis. Luminal alendronate at acidic pH was more damaging than either alendronate at neutral pH or acidic pH alone. These data suggest that alendronate stimulates net ion (Na) transport in esophageal epithelium by increasing apical membrane sodium channel activity and that this occurs with limited morphological change and no alteration in barrier function. Also alendronate is far more damaging at acidic than at neutral pH, suggesting its association with esophagitis requires gastric acid for expression. This expression may occur either by potentiation between the damaging effects of (refluxed) gastric acid and drug or by acid-induced conversion of the drug to a more toxic form.

Selective coactivation of estrogen-dependent transcription by CITED1 CBP/p300-binding protein

CITED1, a CBP/p300-binding nuclear protein that does not bind directly to DNA, is a transcriptional coregulator. Here, we show evidence that CITED1 functions as a selective coactivator for estrogen-dependent transcription. When transfected, CITED1 enhanced transcriptional activation by the ligand-binding/AF2 domain of both estrogen receptor-alpha (ERalpha) and ERbeta in an estrogen-dependent manner, but it affected transcriptional activities of other nuclear receptors only marginally. CITED1 bound directly to ERalpha in an estrogen-dependent manner through its transactivating domain, and this binding activity was separable from its p300-binding activity. CITED1 was strongly expressed in nulliparous mouse mammary epithelial cells and, when expressed in ER-positive MCF-7 breast cancer cells by transduction, exogenous CITED1 enhanced sensitivity of MCF-7 cells to estrogen, stabilizing the estrogen-dependent interaction between p300 and ERalpha. The estrogen-induced expression of the transforming growth factor-alpha (TGF-alpha) mRNA transcript was enhanced in the CITED1-expressing MCF-7 cells, whereas estrogen-induced expression of the mRNA transcripts for progesterone receptor or pS2 was not affected. Chromatin immunoprecipitation assay revealed that endogenous CITED1 is recruited to the chromosomal TGF-alpha promoter in MCF-7 cells in an estrogen-dependent manner but not to the pS2 promoter. These results suggest that CITED1 may play roles in regulation of estrogen sensitivity in a gene-specific manner.

[Intratumoral injection of macroaggragated albumin and colloidal 32P for the treatment of hepatocellular carcinoma]

OBJECTIVE

To study the tumor deposition and systemic distribution of colloidal (32)P in single colloidal (32)P injection and macroaggragated albumin (MAA) injection followed by colloidal (32)P and to evaluate their clinical effects and side effects for the treatment of hepatocellular carcinoma.

METHODS

H(22) hepatocellular cancer cells were inoculated subcutaneously in the right fore leg of Balb/c mice. When the tumors reached to 1.0 cm in diameter about 10 days postinjection, the mice were divided into two groups randomly. In the first group, the tumors were only injected with 1.85 MBq of colloidal (32)P; while in the second group, with 1 +/- 10(5) particles of MAA followed by 1.85 MBq of colloidal (32)P. The radioactivity in the tumor, blood, heart, liver, kidney, spleen, and bone of each animal was determined at 30min, 24 h, 48 h, 8 d, and 16 d postinjection. Histopathology of tumors was observed at 16 d and 1 month postinjection. The ultrasound-guided intratumoral injection of MAA and colloidal (32)P was performed on 30 patients with hepatocellular cancer. The evaluation of efficacy and side effects was made on the basis of clinical manifestations, histopathological changes, variations in tumor size, serum AFP, the functions of heart, liver, kidney, blood routine, and immune functions before and after the treatment.

RESULTS

Intratumoral injection of colloidal (32)P resulted in necrosis and fibrosis of the tumor cells. Pretreatment with MAA before administration of colloidal (32)P effectively decreased the diffusion of colloidal (32)P from the tumor to blood, and led to retention of colloidal (32)P in the tumor for a longer time. After treatment, a significant shrinkage of the tumor size was seen in all cases with the average shrinkage rate of 53.25%. Serum AFP values decreased remarkably. Clinical symptoms alleviated. The survival rate of 1, 2, and 3 years was 90%, 76.67%, 43.33%. No side effect was found.

CONCLUSIONS

Intratumoral injection of MAA and colloidal (32)P is a simple, safe, and effective alternative for the treatment of hepatocellular cancer.

CCR2 and CCR5 receptor-binding properties of herpesvirus-8 vMIP-II based on sequence analysis and its solution structure

Human herpesvirus-8 (HHV-8) is the infectious agent responsible for Kaposi's sarcoma and encodes a protein, macrophage inflammatory protein-II (vMIP-II), which shows sequence similarity to the human CC chemokines. vMIP-II has broad receptor specificity that crosses chemokine receptor subfamilies, and inhibits HIV-1 viral entry mediated by numerous chemokine receptors. In this study, the solution structure of chemically synthesized vMIP-II was determined by nuclear magnetic resonance. The protein is a monomer and possesses the chemokine fold consisting of a flexible N-terminus, three antiparallel beta strands, and a C-terminal alpha helix. Except for the N-terminal residues (residues 1-13) and the last two C-terminal residues (residues 73-74), the structure of vMIP-II is well-defined, exhibiting average rmsd of 0.35 and 0.90 A for the backbone heavy atoms and all heavy atoms of residues 14-72, respectively. Taking into account the sequence differences between the various CC chemokines and comparing their three-dimensional structures allows us to implicate residues that influence the quaternary structure and receptor binding and activation of these proteins in solution. The analysis of the sequence and three-dimensional structure of vMIP-II indicates the presence of epitopes involved in binding two receptors CCR2 and CCR5. We propose that vMIP-II was initially specific for CCR5 and acquired receptor-binding properties to CCR2 and other chemokine receptors.

[Studies of the determination of glycyrrhizin acid kali salt by HPLC and the pharmacokinetics]

To find a practive and quick method determining GK concentration in blood by HPLC and to study its pharmacokinetics. GK from Glycyrrhiza uralensis Fisch was extracted and purified. GK were administered to mice by i.v. and ig. The Concentration of GK in blood at expected time was determined by HPLC. The data was dealed with by 3 P 87 programe. The concentration-time curve of i.v. 0.1% GK 40 mg/kg is in accordance with tow-compartment model. t1/2 alpha = 5.128 min, t1/2 beta = 51.196 min, AUC = 7477.642 (micrograms/ml).min, Cl(s) = 0.0956 microgram/min(microgram/ml). The c-t curve of ig. 2.2% GK 500 mg/kg is in accordance with tow compartment model, t1/2 alpha = 15.97 min, t1/2 beta = 200.05 min, AUC = 2453.96(micrograms/ml).min, Cl(s) = 3.642 micrograms/min(micrograms/ml). HPLC is a quick and practive method to determin the concentration of GK in blood.

Resorbable plate fixation in pediatric craniofacial surgery: long-term outcome

OBJECTIVE

To determine the long-term efficacy of resorbable plate fixation in pediatric patients undergoing craniofacial surgery for congenital anomalies, traumatic deformities, or skull base tumors.

DESIGN

Retrospective case review.

MATERIALS AND METHODS

Medical records of 57 consecutive cases using resorbable plates and screws for craniofacial fixation in patients younger than 18 years were analyzed.

MAIN OUTCOME MEASURES

The status of bone healing postoperatively (anatomical union, malunion, delayed union, or nonunion) and any complications or adverse effects (hardware visibility or palpability, plate extrusion, or infection) were noted.

RESULTS

In midfacial and upper face procedures (54 patients) anatomical union and uncomplicated bone healing occurred in 52 (96%) of the patients. In this same group, complications (plate extrusion) occurred in 2 patients (3.7%) and were resolved using conservative treatment without untoward sequelae. These outcomes are comparable to results using metal osteosynthesis in similar situations. Costs of resorbable hardware are similar to existing metal fixation systems.

CONCLUSIONS

Our data support the use of bioresorbable plate fixation in pediatric craniofacial surgery as a means of avoiding the potential and well-documented problems with rigid metal fixation. Indications include fractures and segmental repositioning in low-stress non-load-bearing areas of the middle and upper craniofacial skeleton. Although there is an initial learning curve in using this technology, we believe the benefits are well worth the effort and represent a major advance in pediatric craniofacial surgery.

The biology of acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a disease associated with fusion oncoproteins invariably involving the retinoic acid receptor (Raralpha). Retinoic acid induces differentiation in APL cells and is successfully used in conjunction with chemotherapy to treat and cure a significant percentage of patients with APL. APL is also a model for disruption of normal retinoid-mediated transcription resulting in blocked differentiation. The study of the molecular mechanisms of APL oncogenesis has revealed novel interactions between fusion oncoproteins and transcriptional coregulators, already leading to new treatment strategies.

The sequence of the human genome

A 2.91-billion base pair (bp) consensus sequence of the euchromatic portion of the human genome was generated by the whole-genome shotgun sequencing method. The 14.8-billion bp DNA sequence was generated over 9 months from 27,271,853 high-quality sequence reads (5.11-fold coverage of the genome) from both ends of plasmid clones made from the DNA of five individuals. Two assembly strategies-a whole-genome assembly and a regional chromosome assembly-were used, each combining sequence data from Celera and the publicly funded genome effort. The public data were shredded into 550-bp segments to create a 2.9-fold coverage of those genome regions that had been sequenced, without including biases inherent in the cloning and assembly procedure used by the publicly funded group. This brought the effective coverage in the assemblies to eightfold, reducing the number and size of gaps in the final assembly over what would be obtained with 5.11-fold coverage. The two assembly strategies yielded very similar results that largely agree with independent mapping data. The assemblies effectively cover the euchromatic regions of the human chromosomes. More than 90% of the genome is in scaffold assemblies of 100,000 bp or more, and 25% of the genome is in scaffolds of 10 million bp or larger. Analysis of the genome sequence revealed 26,588 protein-encoding transcripts for which there was strong corroborating evidence and an additional approximately 12,000 computationally derived genes with mouse matches or other weak supporting evidence. Although gene-dense clusters are obvious, almost half the genes are dispersed in low G+C sequence separated by large tracts of apparently noncoding sequence. Only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA. Duplications of segmental blocks, ranging in size up to chromosomal lengths, are abundant throughout the genome and reveal a complex evolutionary history. Comparative genomic analysis indicates vertebrate expansions of genes associated with neuronal function, with tissue-specific developmental regulation, and with the hemostasis and immune systems. DNA sequence comparisons between the consensus sequence and publicly funded genome data provided locations of 2.1 million single-nucleotide polymorphisms (SNPs). A random pair of human haploid genomes differed at a rate of 1 bp per 1250 on average, but there was marked heterogeneity in the level of polymorphism across the genome. Less than 1% of all SNPs resulted in variation in proteins, but the task of determining which SNPs have functional consequences remains an open challenge.

Multiple histidine kinases regulate entry into stationary phase and sporulation in Bacillus subtilis

Protein homology studies identified five kinases potentially capable of phosphorylating the Spo0F response regulator and initiating sporulation in Bacillus subtilis. Two of these kinases, KinA and KinB, were known from previous studies to be responsible for sporulation in laboratory media. In vivo studies of the activity of four of the kinases, KinA, KinC, KinD (ykvD) and KinE (ykrQ), using abrB transcription as an indicator of Spo0A approximately P level, revealed that KinC and KinD were responsible for Spo0A approximately P production during the exponential phase of growth in the absence of KinA and KinB. In vitro, all four kinases dephosphorylated Spo0F approximately P with the production of ATP at approximately the same rate, indicating that they possess approximately equal affinity for Spo0F. All the kinases were expressed during growth and early stationary phase, suggesting that the differential activity observed in growth and sporulation results from differential activation by signal ligands unique to each kinase.

Ligand-inducible interaction of the DRIP/TRAP coactivator complex with retinoid receptors in retinoic acid-sensitive and -resistant acute promyelocytic leukemia cells

Retinoic acid (RA) signaling is mediated by its nuclear receptors RXR and RAR, which bind to their cognate response elements as a heterodimer, RXR/RAR, and act in concert with coregulatory factors to regulate gene transcription on ligand binding. To identify specific cofactors that interact with the RXR/RAR heterodimer in acute promyelocytic leukemia (APL) cells, a double cistronic construct was used that allowed coexpression of the RXR LBD (ligand binding domain) with the RAR LBD as an affinity matrix to pull down interacting proteins from nuclear extracts prepared from a human APL cell line, NB4. A group of proteins was detected whose interaction with RXR/RAR is ligand inducible. The molecular weight pattern of these proteins is similar to that of a complex of proteins previously identified as DRIP or TRAP, which are ligand-dependent transcription activators of VDR and TR, respectively. The RXR/RAR-interacting proteins from NB4 were confirmed to be identical to the DRIP subunits by comparative electrophoresis, Western blot analysis, and in vitro protein interaction assay. In addition to RXR/RAR, the DRIP component can interact directly with the APL-specific PML-RARalpha fusion protein. The same DRIP complex is present in RA-resistant APL cells and in a variety of cancer cell lines, supporting its global role in transcriptional regulation.

[Clinical study of Astragalus injection plus ligustrazine in protecting myocardial ischemia reperfusion injury]

OBJECTIVE

To investigate the mechanism of Astragalus injection plus ligustrazine in preventing the occurrence of myocardial ischemia reperfusion injury (MIRI) during open heart surgery of cardiopulmonary bypass, and the treating principle of MIRI in TCM.

METHODS

Twenty-four patients suffering from either valvular heart diseases or congenital ventricular septal defect were randomly divided into three treated groups (Astragalus, ligustrazine, Astragalus plus ligustrazine) and the control group, 6 in each group. Blood samples were taken via subclavian central vein at the time before anesthesia (T1), 10 minutes of occlusion of aorta (T2), 10 minutes (T3) and 30 minutes (T4) after the release, and the end of operation (about 180 minutes after release, T5) respectively; EKG was observed, and the levels of asparate aminotransferase (AST), lactate dehydrogenase (LDH), creatine kinase (CK), MB isoenzyme of CK (CK-MB), malondialdehyde (MDA) and the activity of superoxide dismutase (SOD), nitric oxide (NO), nitric oxide synthetase (NOS) were determined.

RESULTS

The treated groups could reduce the levels of AST, LDH, CK, CK-MB, MDA, SOD compared with the control group, particularly Astragalus plus ligustrazine, there had significant difference (P < 0.05, P < 0.01). In NO activity improvement, Astragalus plus ligustrazine won the best effect, Astragalus group the next.

CONCLUSIONS

The mechanism of MIRI is Qi deficiency and blood stasis in TCM, its treating principles should be promoting Qi and removing the blood stasis. According to the authors' study, Astragalus plus ligustrazine could effectively protect against MIRI, which is better than using the 2 medicines separately.

Aplastic anemia is associated with HLA-DRB1*1501 in northern Han Chinese

It has been reported that aplastic anemia (AA) is more common in HLA-DR2-positive individuals than in the general population. We investigated the frequency of some HLA loci of 102 Northern Han Chinese patients with AA and 105 healthy control subjects. Polymerase chain reaction and sequence specific oligonucleotide probe hybridization were used to determine HLA-DR- and HLA-DR2-related DRB1 alleles. The frequency of DR2 is increased in AA patients; the relative risk (RR) was 2.86, and the difference was significant (chi 2 = 11.1, P = .004). The RR of HLA-DRB1*1501 was 3.07, and the difference was significant (chi 2 = 9.42, P = .008). The above results suggest that HLA-DR2 is significantly associated with AA in Northern Han Chinese. HLA-DRB1*1501 is the main subtype of HLA-DR2, and may be the susceptibility gene of AA.

A novel putative transcription factor protein MYT2 that preferentially binds supercoiled DNA and induces DNA synthesis in quiescent cells

Myelin transcription factor 2 (MYT2), a putative transcription factor found in the human central nervous system, was cloned from an expression cDNA library from human T-cells. MYT2 shares weak similarity to bacterial type I topoisomerases and shares 63% sequence identity to a replicase from Leuconostoc mesenteroides. MYT2 preferentially binds supercoiled DNA (scDNA). Incubation of MYT2 and scDNA at or above equal molar ratios generated topoisomer-like patterns that were abolished by deproteination. Thus, MYT2 appears to relax scDNA via a non-enzymatic mechanism. The banding pattern of MYT2-scDNA complexes was shown to be quantisized, saturable and sequence-independent. Microinjection of MYT2 mRNA induced G(o) growth-arrested NIH 3T3 cells to enter the S phase of the cell cycle.

Drug resistance mutations can effect dimer stability of HIV-1 protease at neutral pH

The monomer-dimer equilibrium for the human immunodeficiency virus type 1 (HIV-1) protease has been investigated under physiological conditions. Dimer dissociation at pH 7.0 was correlated with a loss in beta-sheet structure and a lower degree of ANS binding. An autolysis-resistant mutant, Q7K/L33I/L63I, was used to facilitate sedimentation equilibrium studies at neutral pH where the wild-type enzyme is typically unstable in the absence of bound inhibitor. The dimer dissociation constant (KD) of the triple mutant was 5.8 microM at pH 7.0 and was below the limit of measurement (approximately 100 nM) at pH 4.5. Similar studies using the catalytically inactive D25N mutant yielded a KD value of 1.0 microM at pH 7.0. These values differ significantly from a previously reported value of 23 nM obtained indirectly from inhibitor binding measurements (Darke et al., 1994). We show that the discrepancy may result from the thermodynamic linkage between the monomer-dimer and inhibitor binding equilibria. Under conditions where a significant degree of monomer is present, both substrates and competitive inhibitors will shift the equilibrium toward the dimer, resulting in apparent increases in dimer stability and decreases in ligand binding affinity. Sedimentation equilibrium studies were also carried out on several drug-resistant HIV-1 protease mutants: V82F, V82F/I84V, V82T/I84V, and L90M. All four mutants exhibited reduced dimer stability relative to the autolysis-resistant mutant at pH 7.0. Our results indicate that reductions in drug affinity may be due to the combined effects of mutations on both dimer stability and inhibitor binding.

[Observation of preventing and treating effect of Salvia miltiorrhiza composita on patients with ischemic coronary heart disease undergoing non-heart surgery]

OBJECTIVE

To observe the preventing and treating effect of Salvia miltiorrhiza composita (SMC) on patients with ischemic coronary heart disease (CHD) undergoing non-heart surgery.

METHODS

The 108 patients were randomly divided into the control group and treatment group. In the treatment group, each patient of 54 were administered SMC intravenously during the operation. ECG, HR, MAP and SpO2 were observed and bleeding quantity was measured perioperatively.

RESULTS

Effective rate of ECG in treatment group was 90.7% (49/54 cases) and the control group was 35.2% (19/54 cases). There was significant difference between the two groups (P < 0.01). HR of the treatment group was no great flutter but control group became faster (P < 0.05). MAP and SpO2 of the two groups were no significant difference perioperatively. There was no significant difference to bleeding quantity between the two groups.

CONCLUSIONS

SMC could effectively improve and protect myocardial ischemia in patients with CHD undergoing non-heart surgery, and no side effect was found.

Accessibility of selenomethionine proteins by total chemical synthesis: structural studies of human herpesvirus-8 MIP-II

The determination of high resolution three-dimensional structures by X-ray crystallography or nuclear magnetic resonance (NMR) is a time-consuming process. Here we describe an approach to circumvent the cloning and expression of a recombinant protein as well as screening for heavy atom derivatives. The selenomethionine-modified chemokine macrophage inflammatory protein-II (MIP-II) from human herpesvirus-8 has been produced by total chemical synthesis, crystallized, and characterized by NMR. The protein has a secondary structure typical of other chemokines and forms a monomer in solution. These results indicate that total chemical synthesis can be used to accelerate the determination of three-dimensional structures of new proteins identified in genome programs.

A 60 kd MDM2 isoform is produced by caspase cleavage in non-apoptotic tumor cells

The MDM2 oncogene product is a regulator of the p53 tumor suppressor. MDM2 is cleaved by Caspase 3 (CPP32) during apoptosis after aspartic acid-361, generating a 60 kd fragment. Here we report that human tumor cell lines often express high levels of a 60 kd MDM2 isoform (p60) in the absence of apoptosis. We demonstrate that p60 is a product of caspase cleavage of full length MDM2 after residue 361. The protease that cleaves MDM2 in non-apoptotic cells appears to be distinct from the apoptosis-specific Caspase 3, since Caspase 3 substrate poly(ADP-ribose) polymerase (PARP) is not cleaved in cells producing p60. The p60 form of MDM2 is a significant fraction of the p53-bound MDM2 protein in certain tumor cells, suggesting that it functions in the regulation of p53. p60 is also detected in breast tumors overexpressing MDM2. These observations suggest that MDM2 is regulated by caspase processing in non-apoptotic cells, and may account for the MDM2 proteins of similar mobility seen in tumors and other cell lines.

Solution structure of murine macrophage inflammatory protein-2

The solution structure of murine macrophage inflammatory protein-2 (MIP-2), a heparin-binding chemokine that is secreted in response to inflammatory stimuli, has been determined using two-dimensional homonuclear and heteronuclear NMR spectroscopy. Structure calculations were carried out by means of torsion-angle molecular dynamics using the program X-PLOR. The structure is based on a total of 2390 experimental restraints, comprising 2246 NOE-derived distance restraints, 44 distance restraints for 22 hydrogen bonds, and 100 torsion angle restraints. The structure is well-defined, with the backbone (N, Calpha, C) and heavy atom atomic rms distribution about the mean coordinates for residues 9-69 of the dimer being 0.57 +/- 0.16 A and 0.96 +/- 0.12 A, respectively. The N- and C-terminal residues (1-8 and 70-73, respectively) are disordered. The overall structure of the MIP-2 dimer is similar to that reported previously for the NMR structures of MGSA and IL-8 and consists of a six-stranded antiparallel beta-sheet (residue 25-29, 39-44, and 48-52) packed against two C-terminal antiparallel alpha-helices. A best fit superposition of the NMR structure of MIP-2 on the structures of MGSA, NAP-2, and the NMR and X-ray structures of IL-8 are 1.11, 1.02, 1.27, and 1.19 A, respectively, for the monomers, and 1.28, 1.10, 1.55, and 1.36 A, respectively, for the dimers (IL-8 residues 7-14 and 16-67, NAP-2 residues 25-84). At the tertiary level, the main differences between the MIP-2 solution structure and the IL-8, MGSA, and NAP-2 structures involve the N-terminal loop between residues 9-23 and the loops formed by residues 30-38 and residues 53-58. At the quaternary level, the difference between MIP-2 and IL-8, MGSA, or NAP-2 results from differing interhelical angles and separations.

Long-term cytokine alterations following allogeneic blood transfusion

BACKGROUND

Allogeneic blood transfusion is associated with an increased risk of infection and higher cancer recurrence rates. Previous research has shown that blood transfusion results in multiple immune effects, including cytokine alterations. The purpose of this study was to measure the long term kinetics of splenocyte cytokine production in transfused mice.

METHODS

Balb/c mice received either syngeneic transfusion (Syn-BT) or allogeneic transfusion (Allo-BT) from C3H-HeN mice. Splenocyte production of IL-2, IL-6, IL-10, and IFN-gamma was quantitated by ELISA on post-transfusion days 5, 10, 21, and 30.

RESULTS

Both Allo-BT and Syn-BT produced significant alterations in cytokine production, but Allo-BT produced the most dramatic and enduring effects as summarized: IL-2: Production of IL-2 was suppressed at day 5, (p < 0.0001), but then rose, peaking at day 21, 30% greater than control values (p < 0.05). IL-6: Allo-BT mice showed suppression of IL-6 throughout the study period (p < 0.005 vs controls, each time point). IL-10: A 5-fold increase in IL-10 production was seen at day 5 after Allo-BT (p < 0.0001 vs control). Production of IL-10 was suppressed at days 10 and 21 (p < 0.001), but returned to control levels by day 30, gamma-IFN: At day 5 post Allo-BT, gamma-IFN was 4 x greater than controls (p < 0.0001). Gamma-IFN production was suppressed at day 10, but then rose at days 21 and 30 to nearly 3 x control levels (p < 0.0001).

CONCLUSION

Allo-BT produced multiple cytokine alterations that were of prolonged duration. These results provide a theoretic explanation for the multiple, long-term immunomodulating effects seen in patients who have received transfusions.

Role of the histone deacetylase complex in acute promyelocytic leukaemia

Non-liganded retinoic acid receptors (RARs) repress transcription of target genes by recruiting the histone deacetylase complex through a class of silencing mediators termed SMRT or N-CoR. Mutant forms of RARalpha, created by chromosomal translocations with either the PML (for promyelocytic leukaemia) or the PLZF (for promyelocytic leukaemia zinc finger) locus, are oncogenic and result in human acute promyelocytic leukaemia (APL). PML-RARalpha APL patients achieve complete remission following treatments with pharmacological doses of retinoic acids (RA); in contrast, PLZF-RARalpha patients respond very poorly, if at all. Here we report that the association of these two chimaeric receptors with the histone deacetylase (HDAC) complex helps to determine both the development of APL and the ability of patients to respond to retinoids. Consistent with these observations, inhibitors of histone deacetylase dramatically potentiate retinoid-induced differentiation of RA-sensitive, and restore retinoid responses of RA-resistant, APL cell lines. Our findings suggest that oncogenic RARs mediate leukaemogenesis through aberrant chromatin acetylation, and that pharmacological manipulation of nuclear receptor co-factors may be a useful approach in the treatment of human disease.

Arsenic trioxide as an inducer of apoptosis and loss of PML/RAR alpha protein in acute promyelocytic leukemia cells

BACKGROUND

Retinoids, which are derivatives of vitamin A, induce differentiation of acute promyelocytic leukemia (APL) cells in vitro and in patients. However, APL cells develop resistance to retinoic acid treatment. Arsenic trioxide (As2O3) can induce clinical remission in patients with APL, including those who have relapsed after retinoic acid treatment, by inducing apoptosis (programmed cell death) of the leukemia cells. In this study, we investigated the molecular mechanisms by which As2O3 induces apoptosis in retinoic acid-sensitive NB4 APL cells, in retinoic acid-resistant derivatives of these cells, and in fresh leukemia cells from patients.

METHODS

Apoptosis was assessed by means of DNA fragmentation analyses, TUNEL assays (i.e., deoxyuridine triphosphate labeling of DNA nicks with terminal deoxynucleotidyl transferase), and flow cytometry. Expression of the PML/RAR alpha fusion protein in leukemia cells was assessed by means of western blotting, ligand binding, and immunohistochemistry. Northern blotting and ribonuclease protection assays were used to evaluate changes in gene expression in response to retinoic acid and As2O3 treatment.

RESULTS AND CONCLUSIONS

As2O3 induces apoptosis without differentiation in retinoic acid-sensitive and retinoic acid-resistant APL cells at concentrations that are achievable in patients. As2O3 induces loss of the PML/RAR alpha fusion protein in NB4 cells, in retinoic-acid resistant cells derived from them, in fresh APL cells from patients, and in non-APL cells transfected to express this protein. As2O3 and retinoic acid induce different patterns of gene regulation, and they inhibit the phenotypes induced by each other. Understanding the molecular basis of these differences in the effects of As2O3 and retinoic acid may guide the clinical use of arsenic compounds and provide insights into the management of leukemias that do not respond to retinoic acid.

[Study of the inclusion compound of rutin with beta-cyclodextrin]

In order to improve the solubility of Rutin in aqueous solution and the stability, the inclusion compound of Rutin with beta-CD was manufacted by saturated aqueous solution method. The formation of the inclusion compound was confirmed by IR spectroscopy and differential scauning calorimetry. The content of Rutin in inclusion compound was determined by UV. The results indicated that the inclusion compound of Rutin with beta-CD was formed. Quantitative analysis demmonstrated that the molecular ratio of Rutin to beta-CD in the complex was 1:1 with the inclusion constant of 283.79 L/mol at 30 degrees C. The dissolubility of Rutin in water has added to 643.19 mg/L (20 degrees C).