Identification of a novel HLA-DRB allele, HLA-DRB1*1461

We describe the identification of a new DRB1*14 allele, DRB1*1461, found in a Chinese individual. The novel allele has been identified in routine polymerase chain reaction-sequence-specific oligonucleotide and sequence-based typing. The nucleotide sequence of DRB1*1461 is identical to DRB1*1404 except for a single substitution in codon 16 (TAT-->CAT), leading to a change from Tyr to His.

A novel allele, HLA-A*0128, identified by sequence-based typing in a Chinese individual

In this report, we describe the identification of a novel allele HLA-A*0128, which was found in a registered donor from China Marrow Donor Program. The A*0128 allele differs from the A*0113 by one nucleotide substitutions in exon 2 at position 282 (G-->C). The mutation results in a codon change: at codon 70 where a glutamine acid is substituted by a histidine acid.

Identification of a novel HLA-B allele, HLA-B*3713, in a Chinese individual

A novel human leukocyte antigen (HLA) class I allele, HLA-B*3713, has been identified in a Chinese individual. The HLA-B*3713 allele differs from the closest matching allele B*370101 by one nucleotide substitutions in exon 3 at nt 527(T-->A), resulting in an amino acid change from Val (GTG) to Glu (GAG) at codon 152.

Identification of 11 novel HLA alleles found during typing of unrelated registry donors in China

Eleven novel human leukocyte antigen (HLA) alleles were identified during routine sequence-specific oligonucleotide probe (SSOP) typing (LABType; One Lambda Inc., Los Angeles, CA) of volunteers for a hematopoietic stem cell registry in Beijing, China. The new alleles were detected when one or more probes gave an unexpected reactivity pattern.

Lattice Boltzmann models for nonideal fluids with arrested phase-separation

The effects of midrange repulsion in lattice Boltzmann models on the coalescence and/or breakup behavior of single-component, nonideal fluids are investigated. It is found that midrange repulsive interactions allow the formation of spraylike, multidroplet configurations, with droplet size directly related to the strength of the repulsive interaction. The simulations show that just a tiny 10% of midrange repulsive pseudoenergy can boost the surface:volume ratio of the phase-separated fluid by nearly two orders of magnitude. Drawing upon a formal analogy with magnetic Ising systems, a pseudopotential energy is defined, which is found to behave similar to a quasiconserved quantity for most of the time evolution. This offers a useful quantitative indicator of the stability of the various configurations, thus helping the task of their interpretation and classification. The present approach appears to be a promising tool for the computational modeling of complex flow phenomena, such as atomization, spray formation, microemulsions, breakup phenomena, and possibly glassylike systems as well.

Magnetic resonance microscopy and immunohistochemistry of the CNS of the mutant SOD murine model of ALS reveals widespread neural deficits

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily affects motor neurons and descending motor tracts of the CNS. We have evaluated the CNS of a murine model of familial ALS based on the over-expression of mutant human superoxide dismutase (mSOD; G93A) using magnetic resonance microscopy (MRM) and immunohistochemistry (IHC). Three-dimensional volumetric analysis was performed from 3D T2*-weighted images acquired at 17.6 T at isotropic resolutions of 40 mum. Compared to controls, mSOD mice had significant reductions in the volumes of total brain, substantia nigra, striatum, hippocampus, and internal capsule, with decreased cortical thickness in primary motor and somatosensory cortices. In the spinal cord, mSOD mice had significantly decreased volume of both the total grey and white matter; in the latter case, the volume change was confined to the dorsal white matter. Increased apoptosis, GFAP positive astrocytes, and/or activated microglia were observed in all those CNS regions that showed volume loss except for the hippocampus. The MRM findings in mSOD over-expressing mice are similar to data previously obtained from a model of ALS-parkinsonism dementia complex (ALS-PDC), in which neural damage occurred following a diet of washed cycad flour containing various neurotoxins. The primary difference between the two models involves a significantly greater decrease in spinal cord white matter volume in mSOD mice, perhaps reflecting variations in degeneration of the descending motor tracts. The extent to which several CNS structures are impacted in both murine models of ALS argues for a reevaluation of the nature of the pathogenesis of ALS since CNS structures involved in Parkinson's and Alzheimer's diseases appear to be affected as well.

Presynaptic localization of a truncated isoform of the type 2 corticotropin releasing factor receptor in the cerebellum

It is now well established that corticotropin releasing factor is present in two major excitatory afferent systems to the cerebellum, namely climbing fibers and mossy fibers. Two major classes of corticotropin releasing factor receptors, each with unique binding characteristics, have been identified as type 1 and type 2. In this study we used an antibody made to the n-terminus of the type 2 corticotropin releasing factor receptor. Characterization of this antibody showed that it strongly labeled a protein with a molecular weight of 16-32 kDa and only faintly labels a 62-83 kDa protein. The lower molecular weight protein corresponds to the weight of a recently described truncated isoform of this receptor that is designated corticotropin releasing factor-type 2alpha-truncated isoform. We carried out transfection paradigms using corticotropin releasing factor-type 2alpha-truncated isoform constructs and confirmed that the antibody recognized the truncated isoform of the type 2 corticotropin releasing factor receptor. Further, light and electron microscopic studies were carried out in mice and rats to define the distribution of the truncated receptor. Immunoreactivity is evident in the basal region of many, but not all Purkinje cell bodies and their initial axonal segments, as well as the initial axonal segments of isolated Golgi cells, and cerebellar nuclear neurons. In addition, punctate elements in the molecular layer were immunolabeled. The localization of the receptor to the initial segment of Purkinje cells was confirmed with electron microscopy. Further, the punctate labeling in the molecular layer was localized to parallel fibers and their terminals. In conclusion, evidence has been presented to show that distinct isoforms of the corticotropin releasing factor receptor are present in the cerebellum. The complex interactions between corticotropin releasing factor and other members of the corticotropin releasing factor family of peptides with both pre- and postsynaptic receptors support a growing concept that corticotropin releasing factor plays an important role in modulating activity in cerebellar circuits and ultimately in controlling motor behavior.

Effects of human soluble BAFF synthesized in Escherichia coli on CD4+ and CD8+ T lymphocytes as well as NK cells in mice

B cell-activating factor belonging to the TNF family (BAFF, also called BLyS, TALL-1, zTNF-4, or THANK) is an important survival factor for B lymphocytes. In this study, we injected mouse abdominal cavity with human soluble BAFF (hsBAFF, 0.01, 0.1, 0.5, 2 mg/kg body mass) synthesized in Escherichia coli. On the 8th day after injection, we investigated the effects of hsBAFF on immune functional activities of splenic B lymphocytes, CD4(+) and CD8(+) T lymphocytes and natural killer (NK) cells in mice. The results showed that B lymphocyte proliferation significantly increased in hsBAFF-treated groups with dosages of 0.1 mg/kg (p<0.05), 0.5 and 2 mg/kg (p<0.01). We observed a dose-dependent increase of CD4(+) T lymphocyte percentage and significantly higher values in 0.5 and 2 mg/kg hsBAFF-treated groups (p<0.05 and p<0.001, respectively) compared to control group, but CD8(+) T lymphocyte percentage remained unchanged. The ratio of CD4(+) to CD8(+) T lymphocytes rose with increasing hsBAFF dosage (p<0.05 for 2 mg/kg hsBAFF vs. control). Significantly stronger NK cell activities were found in 0.5 and 2 mg/kg hsBAFF-treated groups (p<0.05). The main finding of this study is that the hsBAFF can enhance immune responses in the body by increasing B lymphocyte and CD4(+) T lymphocyte function as well as elevating NK cell activity.

Increased phospho-adducin immunoreactivity in a murine model of amyotrophic lateral sclerosis

Adducins alpha, beta and gamma are proteins that link spectrin and actin in the regulation of cytoskeletal architecture and are substrates for protein kinase C and other signaling molecules. Previous studies have shown that expressions of phosphorylated adducin (phospho-adducin) and protein kinase C are increased in spinal cord tissue from patients who died with amyotrophic lateral sclerosis, a neurodegenerative disorder of motoneurons and other cells. However, the distribution of phospho-adducin immunoreactivity has not been described in the mammalian spinal cord. We have evaluated the distribution of immunoreactivity to serine/threonine-dependent phospho-adducin at a region corresponding to the myristoylated alanine-rich C kinase substrate-related domain of adducin in spinal cords of mice over-expressing mutant human superoxide dismutase, an animal model of amyotrophic lateral sclerosis, and in control littermates. We find phospho-adducin immunoreactivity in control spinal cord in ependymal cells surrounding the central canal, neurons and astrocytes. Phospho-adducin immunoreactivity is localized to the cell bodies, dendrites and axons of some motoneurons, as well as to astrocytes in the gray and white matter. Spinal cords of mutant human superoxide dismutase mice having motoneuron loss exhibit significantly increased phospho-adducin immunoreactivity in ventral and dorsal horn spinal cord regions, but not in ependyma surrounding the central canal, compared with control animals. Increased phospho-adducin immunoreactivity localizes predominantly to astrocytes and likely increases as a consequence of the astrogliosis that occurs in the mutant human superoxide dismutase mouse with disease progression. These findings demonstrate increased immunoreactivity against phosphorylated adducin at the myristoylated alanine-rich C kinase substrate domain in a murine model of amyotrophic lateral sclerosis. As adducin is a substrate for protein kinase C at the myristoylated alanine-rich C kinase substrate domain, the increased phospho-adducin immunoreactivity is likely a consequence of protein kinase C activation in neurons and astrocytes of the spinal cord and evidence for aberrant phosphorylation events in mutant human superoxide dismutase mice that may affect neuron survival.

Isomer formation and other issues in the substitution reactions of oxorhenium(V) complexes of 2,2'-bipyridine and related ligands

Two new oxorhenium(V) compounds were prepared and characterized: MeReO(mtp)(Me(2)Bpy) and MeReO(mtp)(dppb), where mtpH(2) is 2-(mercaptomethyl)thiophenol, Me(2)Bpy is 4,4'-dimethyl-2,2'-bipyridine, and dppb is 1,2-(Ph(2)P)(2)C(6)H(4). The more stable geometric isomer of MeReO(mtp)X forms MeReO(mtp)Y (X, Y = PR(3), NC(5)H(4)R) in two steps, both of which show a first-order dependence on [Y], proceeding through the metastable geometric isomer MeReO(mtp)Y. When Y = PR(3), no MeReO(mtp)Y was detected at equilibrium; with NC(5)H(4)R, however, both isomers were detected. The values of K(PyPy) were 8.5-9.8, largely irrespective of R; for NC(5)H(5), DeltaH degrees = -4.47 +/- 0.29 kJ and DeltaS degrees = 3.9 +/- 1.0 J K(-1). For the more symmetric edt ligand, geometric isomers do not exist, but enantiomers do. The rate of racemization of MeReO(edt)(NC(5)H(4)R) was proportional to [Py]. Values of k(rac) for 16 compounds span the range 135-370 L mol(-1) s(-1) in C(6)H(6) at 25 degrees C (rho = -0.39 +/- 0.07). In toluene-d(8), k(rac) for 4-picoline has DeltaH = 28.9 +/- 0.4 kJ, DeltaS() = -103.6 +/- 0.9 J K(-1). A common mechanism applies to ligand substitution (mtp) and racemization (edt). MeReO(dithiolate)Py complexes react with Bpy, Me(2)Bpy, Phen, and Me(2)Phen to form six-coordinate chelates, with rate constants 0.024-0.74 L mol(-1) s(-1) at 25 degrees C, some 10(3) times smaller than with pyridines, no doubt owing to the bulk of the bidentates. Values of DeltaS are -86 to -138 J K(-1), reflecting substantial orientational barriers as well as the inherent contribution of the associative mechanism. The product is MeReO(mtp)(Me(2)Bpy). The formation of the metastable isomer is consistent with the mechanism assigned to the ligand substitution and racemization reactions. Such compounds, once formed, no longer participate in ligand substitution reactions at reasonable rates. The formation of the metastable isomer is consistent with the mechanism assigned to the ligand substitution and racemization reactions.

Luminol chemiluminescence in unbuffered solutions with a cobalt(II)-ethanolamine complex immobilized on resin as catalyst and its application to analysis

Using a heterogeneous catalyst, Co(II)-ethanolamine complex sorbed on Dowex-50W resin, the chemiluminescence (CL) of luminol in unbuffered or weakly acidic solution was studied in the presence of H2O2. The maximum luminol CL wavelength at pH 5.7 was 448 nm, 23 nm longer than that in a basic solution (pH 10.5). Three different ligands, mono-, di-, and triethanolamine, and six transition metal ions, Co(II), Cu(II), Ni(II), Mn-(II), Fe(II), and Fe(III) were compared by CL measurements. The CL intensity decreased in the order mono- > di- > triethanolamine and Co(II) > Cu(II) > Ni(II) > Fe-(III) > Mn(II) > Fe(II). This heterogeneous CL system was developed as H2O2 and glucose flow-through sensors. Detection limits (S/N = 3) of H2O2 and glucose using Dowex-50W-X4-Co(II)-monoethanolamine as catalyst are 1 x 10(-7) M and 1 x 10(-6) M, respectively. On the basis of the studies of the CL, fluorescence, UV-vis and ESCA spectra and the effect of dissolved oxygen in luminol solution, a mechanism for CL emission in unbuffered solution was considered as the formation of a superoxide radical ion during the decomposition of H2O2 catalyzed by the Co(II)-ethanolamine immobilized resin. Then the superoxide radical ion acted on luminol and the CL was emitted. The applications of the proposed method to determine H2O2 in rainwater without any special pretreatment and glucose in human urine and orange juice samples give satisfactory results.

Zap-70-independent Ca(2+) mobilization and Erk activation in Jurkat T cells in response to T-cell antigen receptor ligation

The tyrosine kinase ZAP-70 has been implicated as a critical intermediary between T-cell antigen receptor (TCR) stimulation and Erk activation on the basis of the ability of dominant negative ZAP-70 to inhibit TCR-stimulated Erk activation, and the reported inability of anti-CD3 antibodies to activate Erk in ZAP-70-negative Jurkat cells. However, Erk is activated in T cells receiving a partial agonist signal, despite failing to activate ZAP-70. This discrepancy led us to reanalyze the ZAP-70-negative Jurkat T-cell line P116 for its ability to support Erk activation in response to TCR/CD3 stimulation. Erk was activated by CD3 cross-linking in P116 cells. However, this response required a higher concentration of anti-CD3 antibody and was delayed and transient compared to that in Jurkat T cells. Activation of Raf-1 and MEK-1 was coincident with Erk activation. Remarkably, the time course of Ras activation was comparable in the two cell lines, despite proceeding in the absence of LAT tyrosine phosphorylation in the P116 cells. CD3 stimulation of P116 cells also induced tyrosine phosphorylation of phospholipase C-gamma1 (PLCgamma1) and increased the intracellular Ca(2+) concentration. Protein kinase C (PKC) inhibitors blocked CD3-stimulated Erk activation in P116 cells, while parental Jurkat cells were refractory to PKC inhibition. The physiologic relevance of these signaling events is further supported by the finding of PLCgamma1 tyrosine phosphorylation, Erk activation, and CD69 upregulation in P116 cells on stimulation with superantigen and antigen-presenting cells. These results demonstrate the existence of two pathways leading to TCR-stimulated Erk activation in Jurkat T cells: a ZAP-70-independent pathway requiring PKC and a ZAP-70-dependent pathway that is PKC independent.

Uptake and distribution of rare earth elements in rice seeds cultured in fertilizer solution of rare earth elements

The uptake behavior of rare earth elements (REEs) under pot conditions using deionized water and a REE fertilizer solution as the culture media as well as the distribution of REEs in rice proteins were studied. The uptake of REEs in rice seeds increased dramatically after a lag period of approximately three days. Roots can accumulate a much higher content of REEs than germs and the resting seeds. The REE content in each water-soluble (albumin) and salt-soluble (globulin) component of the rice seeds accounted for 5-8% and 4-6% of the total REEs, respectively. However, there are less than 1.5% of the total REEs were found in the alcohol-soluble (prolamin) and acetic acid-soluble (glutelin) components. The high performance liquid chromatography (HPLC) in the gel permeation and the reserved-phase were used to monitor changes in the molecular weight distribution changes of the soluble proteins of rice seeds during germination after having been cultured in the same solution for seven days. No changes occurred in the prolamin, while a slight change occurred in the albumin, globulin and glutelin. Fractionation of the albumin of rice seeds cultured in a REE fertilizer solution on the Sephadex G-100 column indicated that REEs, especially Ce, La, Pr and Nd, were associated mainly with biological compounds of a molecular weight between 10,000 and 12,000.

Mutations in the regulatory domain of cystathionine beta synthase can functionally suppress patient-derived mutations in cis

Human cystathionine beta--synthase (CBS) is an S-adenosylmethionine-regulated enzyme that plays a key role in the metabolism of homocysteine. Mutations in CBS are known to cause homocystinuria, an inborn error in metabolism. We previously developed a yeast functional assay for CBS and used it to characterize mutations found in homocystinuric patients. We discovered that many patient-derived mutations are functionally suppressed by deletion of the C-terminal 142 amino acids, which contain a 53 amino acid motif known as the CBS domain. This domain is found in a wide variety of proteins of diverse biological function. Here we have used a genetic screen to identify missense mutations in the C-terminal region of CBS that can suppress the most common patient mutation, I278T. Seven suppressor mutations were identified, four of which map to the CBS domain. When combined in cis with another pathogenic mutation, V168M, six of seven of the suppressor mutations rescued the yeast phenotype. Enzyme activity analyses indicate that the suppressors restore activity from <2% to 17--64% of the wild-type levels. Analysis of the suppressor mutations in the absence of the pathogenic mutation shows that six of the seven suppressor alleles have lost enzymatic responsiveness to S-adenosylmethionine. Using homology modeling, we show that the suppressor mutations appear to map on one face of the CBS domain. Our results indicate that subtle changes to the C-terminus of CBS can restore activity to mutant proteins and provide a rationale for screening for compounds that can activate mutant CBS alleles.

[Detection of TT virus DNA and sequence analysis of TTV gene in sera from young children in Nanjing]

OBJECTIVE

To investigate the prevalence of TTV genomes in young children from Nanjing and establish the PCR method for detecting TTV DNA.

METHODS

A hemi-nested polymerase chain reaction (PCR) assay was established to detect TTV DNA in 110 young children and two PCR-amplified products were sequenced and the data were analyzed with the computer programs.

RESULTS

TTV DNA was detected in 14 out of 110 children, and 222 bp sequences of 2 isolates from the children were analyzed. Compared with representative of published isolates, they have the nucleotide identity of 93.7%-98.6% with TX011.

CONCLUSIONS

The infection rate of TTV in children is 12.73%, and 2 isolates from children belong to subgroup G1b. Our results indicates that TTV could be transmitted via other pathway besides hematogenous one, and TTV could be carried by healthy population.

A role for Drosophila Drac1 in neurite outgrowth and synaptogenesis in the giant fiber system

Recent studies have shown the small GTPases, Rac1, Rho, and CDC42, to have a role in axon guidance. To assess their participation in synapse assembly and function we have expressed various forms of Drac1 in the giant fiber system of Drosophila. Overexpression of wild-type Drac1 in the giant fiber (GF) lead to a disruption in axonal morphology; axons often terminate prematurely in a large swelling in the target area but lack the normal lateral bend where the synapse with the jump motor neuron would normally be found. Electrophysiological assays revealed longer latencies and lowering following frequencies indicating defects in the synapse between the GF and the tergotrochanteral motor neuron (TTMn). Thickened abnormal GF dendrites were also observed in the brain. Overexpression of the dominant-negative form of Drac1, (N17), resulted in axons that produced extra branches in the second thoracic neuromere (T2); however, the synaptic connection to the TTMn was present and functioned normally. Conversely, expression of the constitutively active form, Drac1(V12), resulted in a complete lack of neurite outgrowth and this was also seen with overexpression of Dcdc42(V12). In the absence of a GF, these flies showed no response in the jump (TTM) or flight (DLM) muscles upon brain stimulation. Taken together these results show that the balance of actin polymerization and depolymerization determines local process outgrowth and thereby synapse structure and function.

Relations of tumor suppressor gene p16 and RB to early diagnosis of lung cancer

OBJECTIVES

To study the incidence and mechanism of the tumor suppressor gene p16 and RB inactivation in lung cancer, and to investigate their relations to biological characteristics, clinical pathological diagnosis and gene classification.

METHODS

Immunohistochemistry, double in situ hybridization, PCR, PCR-SSCP, and sequencing were used to study the changes in the p16 and RB genes in 106 patients with lung cancer. The specimen of normal lung tissue from the patients with lung cancer and specimens of the 23 patients with benign lung diseases were studied in contrast to those of the same patients.

RESULTS

The total expression rate of the p16 and RB genes in the lung cancer tissues of the 106 patients was lower than that in normal lung tissues and tissues of benign lung diseases and was specially related to histological type, metastasis, and clinical stage of lung cancer. In stage I and II lung cancer, the obvious inactivation rate of the tumor suppressor gene p16 or RB was 32.6% or 28.3%. The p16 inactivation appeared largely in non-small cell lung cancer (50.1%), and the RB inactivation largely in small cell lung cancer (88.2%). Homozygous deletion, methylation, and mutation were three mechanisms for the p16 gene inactivation. The deletion rate of the p16 exon 1 and/or exon 2 was 25.8% in the patients with non-small cell lung cancer. Fifteen patients (16.9%) showed methylation at the SmaI sites of CpG island of the p16 gene. PCR-SSCP and sequencing revealed p16 gene mutation in 9 of the 106 patients with lung cancer.

CONCLUSIONS

The p16 and RB genes may play an important role in genesis and progression of lung cancer. The inactivation of the p16 or RB gene may be an early sign of lung canceration, that is important for the early diagnosis. A new gene classification model for lung cancer diagnosis would be set up based on the research of the p16 and RB genes.

Deficiency of PTEN in Jurkat T cells causes constitutive localization of Itk to the plasma membrane and hyperresponsiveness to CD3 stimulation

Pleckstrin homology (PH) domain binding to D3-phosphorylated phosphatidylinositides (PI) provides a reversible means of recruiting proteins to the plasma membrane, with the resultant change in subcellular localization playing a key role in the activation of multiple intracellular signaling pathways. Previously we found that the T-cell-specific PH domain-containing kinase Itk is constitutively membrane associated in Jurkat T cells. This distribution was unexpected given that the closely related B-cell kinase, Btk, is almost exclusively cytosolic. In addition to constitutive membrane association of Itk, unstimulated JTAg T cells also exhibited constitutive phosphorylation of Akt on Ser-473, an indication of elevated basal levels of the phosphatidylinositol 3-kinase (PI3K) products PI-3,4-P(2) and PI-3,4,5-P(3) in the plasma membrane. Here we describe a defect in expression of the D3 phosphoinositide phosphatase, PTEN, in Jurkat and JTAg T cells that leads to unregulated PH domain interactions with the plasma membrane. Inhibition of D3 phosphorylation by PI3K inhibitors, or by expression of PTEN, blocked constitutive phosphorylation of Akt on Ser-473 and caused Itk to redistribute to the cytosol. The PTEN-deficient cells were also hyperresponsive to T-cell receptor (TCR) stimulation, as measured by Itk kinase activity, tyrosine phosphorylation of phospholipase C-gamma1, and activation of Erk compared to those in PTEN-replete cells. These data support the idea that PH domain-mediated association with the plasma membrane is required for Itk activation, provide evidence for a negative regulatory role of PTEN in TCR stimulation, and suggest that signaling models based on results from Jurkat T-cell lines may underestimate the role of PI3K in TCR signaling.

Syntheses and structures of rhenium(IV) and rhenium(V) complexes with ethanedithiolato ligands

A novel dimeric rhenium(IV) complex, [Re2(SCH2CH2S)4], and a monomeric methyloxorhenium(V) complex, [CH3ReO(SCH2CH2S)PPh3], were synthesized from methyloxorhenium(V) complexes and characterized crystallographically. The structure of [Re2(SCH2CH2S)4], the formation reaction of which showed surprising demethylation conceivably through the homolytic cleaveage of the rhenium-carbon bond, features distorted trigonal prismatic coordination of sulfurs around the metal center and a rhenium-rhenium triple bond. A revised structure, [Tc2(SCH2CH2S)4], is proposed for a related technetium complex, originally identified as [Tc2(SCH2CH2S)2(SCH=CHS)2] (Tisato et al. Inorg. Chem. 1993, 32, 2042). Additionally, a new compound, CH3Re(O)(SPh)2PPh3, was prepared.