Analysis of HIV-1 CRF07_BC gag p6 sequences indicating novel deletions in the central region of p6

We amplified gag sequences from 66 individuals infected with HIV-1 CRF07_BC during 2003-2005 in the Xinjiang region of China. A novel deletion of 7aa (including a KELY motif) in the central region of the CRF07_BC gag p6 domain was detected, which has not been reported in other HIV-1 subtypes. Further deletions of up to 13aa (including KQE and KELY motifs) was also found in this domain, representing the biggest natural deletion up to now. Moreover, the CD4+ count and viral load level indicated that 1-13aa deletions in CRF07_BC gag p6 do not have a significant effect on viral replication and fitness.

Genetic analysis of the LKB1/STK11 gene in hepatocellular carcinomas

The tumour suppressor gene, LKB1/STK11, has been mapped to chromosome 19p13, a region showing frequent allelic loss in various human cancers, including hepatocellular carcinoma (HCC). Additionally, LKB1 physically associates with p53 and regulates p53-dependent apoptotic pathways. To investigate whether genetic alterations of LKB1 could be involved in the tumorigenesis of HCC, we analysed the genetic alterations of the LKB1 and p53 genes in seven dysplastic nodules and 80 HCCs. We found one LKB1 missense mutation, CCG-->CTG (Pro-->Leu) at codon 281 within the kinase domain. We also found allelic loss in six of 27 (22%) informative HCC cases and all of them were HBV-positive cases. In addition, we detected seven missense, one nonsense and one silent mutations (nine of 80, 11%) of p53 in HCCs only. These results suggest that genetic alterations of the LKB1 or p53 genes may play an important role in tumour development or progression of a sub-set of HCCs, and may also provide alternative mechanisms to protect the HCC cell from p53-dependent apoptosis.

The microtubule lattice--dynamic instability of concepts

In the February 1995 issue of trends in CELL BIOLOGY, Linda Amos presented her view of our current understanding of the lattice structure of microtubules, 20 years after publication of the original paper describing the A- and B-lattices for flagellar microtubules. However, the question of the lattices of flagellar and cytoplasmic microtubules remains a matter for debate. In this article, Eckhard Mandelkow, Young-Hwa Song and Eva-Maria Mandelkow argue that the B-lattice is predominant, implying structural asymmetry for most microtubules.

Mobile e-Health: The Unwired Evolution of Telemedicine

The movement of telemedicine from desktop platforms to wireless and mobile configurations may have a significant impact on future health care. This paper reviews some of the latest technologies in wireless communication and their application in health care. The new technologies can make the remote medical monitoring, consulting, and health care more flexible and convenient. But, there are challenges for successful wireless telemedicine, which are addressed in this paper.

Association between HLA-DR B1 and clinical features of adult onset Still's disease in Korea

OBJECTIVE

To determine whether HLA-DR alleles are associated with the development and clinical features of Adult Onset Still's Disease (AOSD) in Korea.

METHODS

Forty-seven patients (41 women, 6 men, mean age at diagnosis 31.6 yr) meeting Yamaguchi's criteria for AOSD and 144 healthy controls were enrolled in this study. The patients with AOSD were subdivided into groups according to their chronicity: monocyclic systemic, polycyclic systemic, and chronic destructive type, and were furthermore classified as non-articular, oligoarticular or polyarticular types (having arthritis involving 5 or more joints) according to the extent of articular involvement. HLA-DRB1 genotypes were assessed by PCR-SSOP.

RESULTS

Patients with AOSD had more frequent DRB1*12 (p = 0.028, relative risk (RR) = 2.27, 95% confidence interval (CI): 1.08-4.80) and DRB1*15 (p = 0.013, RR = 2.16, 95% CI: 1.17-4.00). They had less frequent DRB1*04 (p = 0.006, RR = 0.35, 95% CI: 0.16-0.75) compared to controls. DRB1*14 (p = 0.011, RR = 3.80, 95% CI: 1.27-11.31) were associated with the monocyclic systemic type.

CONCLUSION

Korean AOSD patients had more frequent DRB1*12 and DRB1*15, and less frequent HLA-DRB1*04. The patients with the monocyclic systemic type had more frequent DRB1*14 alleles. This study suggests that Korean AOSD patients have distinct immunogenetic profiles, and that it would be valuable to assess the relationships between HLA-DRB1 genes and polymorphisms of proinflammatory cytokines in the pathogenesis of AOSD.

Preparation and characterisation of polyaluminium silicate chloride coagulant

To improve the coagulation efficiency for water treatment purposes, a composite aluminium-silicon coagulant, the polyaluminium silicate chloride was prepared and characterised. The preparation process included the preparation of polyaluminium chloride and polysilicic acid followed by the compounding of the two solutions. The prepared polyaluminium silicate chloride coagulant solution had an aluminium concentration of 0.10 mole per litre, hydroxyl to aluminium molar ratios between 0.5 and 2.0, and silicon to aluminium molar ratios between 0.075 and 0.075. Aluminium-27 nuclear magnetic resonance spectroscopy, photon correlation spectroscopy, streaming current measurement, jar tests and pilot-scale coagulation tests were employed to study the aluminium speciation, particle size distribution, electrokinetic and coagulation properties of this composite coagulant. In comparison with polyaluminium chloride, polyaluminium silicate chloride contains less polynuclear aluminium [AlO4Al12(OH)24(H2O)12]7+ and shows smaller charge neutralisation capacity. However, its particle size shows a significant increase, which enhances the coagulation efficiency. The results show that polyaluminium silicate chloride is an efficient composite coagulant for water treatment.

Production of duck-chicken chimeras by transferring early blastodermal cells

Duck blastodermal cells isolated from Stage X embryos of Maya ducks were injected into subgerminal cavity of recipient Stage X chicken embryos treated with gamma-irradiation or untreated. Eleven somatic chimeras were obtained based on plumage color and were raised to sexual maturity. To test for germline chimerism, progeny tests were performed by mating the chimeras with Maya ducks. A total of 622 eggs was collected and incubated. Fertility rate and hatchability were 2.9% (18/622) and 1.0% (6/622), respectively. The six duck hatchlings were from Chimera 9801 and were considered to be derived from the germ cells developed from the donor Maya blastodermal cells, indicating that Chimera 9801 is a germline chimera.

Dynamics and cooperativity of microtubule decoration by the motor protein kinesin

We describe a theoretical and experimental analysis of the interaction between microtubules and dimeric motor proteins (kinesin, NCD), with special emphasis on the stoichiometry of the interaction, cooperative effects, and their consequences for the interpretation of biochemical and image reconstruction results. Monomeric motors can bind equivalently to microtubules without interference, at a stoichiometry of one motor head per tubulin subunit (alphabeta-heterodimer). By contrast, dimeric motors can interact with stoichiometries ranging between one and two heads per tubulin subunit, depending on binding constants of the first head and the subsequent binding of the second head, and the concentration of dimers in solution. Further, we show that an attractive interaction between the bound motor molecules can explain the higher periodicities observed in decorated microtubules (e.g. 16 nm periodicity), and the non-uniform decoration of a population of microtubules and give an estimate of the strength of this interaction.

BRCA1 and GADD45 mediated G2/M cell cycle arrest in response to antimicrotubule agents

BRCA1 is a tumour suppressor gene implicated in the predisposition to early onset breast and ovarian cancer. We have generated cell lines with inducible expression of BRCA1 to evaluate its role in mediating the cellular response to various chemotherapeutic drugs commonly used in the treatment of breast and ovarian cancer. Induction of BRCA1 in the presence of Taxol and Vincristine resulted in a dramatic increase in cell death; an effect that was preceded by an acute arrest at the G2/M phase of the cell cycle and which correlated with BRCA1 mediated induction of GADD45. A proportion of the arrested cells were blocked in mitosis suggesting activation of both a G2 and a mitotic spindle checkpoint. In contrast, no specific interaction was observed between BRCA1 induction and treatment of cells with a range of DNA damaging agents including Cisplatin and Adriamycin. Inducible expression of GADD45 in the presence of Taxol induced both G2 and mitotic arrest in these cells consistent with a role for GADD45 in contributing to these effects. Our results support a role for both BRCA1 and GADD45 in selectively regulating a G2/M checkpoint in response to antimicrotubule agents and raise the possibility that their expression levels in cells may contribute to the toxicity observed with these compounds.

Systemic lupus erythematosus presenting earlier as retinal vaso-occlusion

Retinal vascular lesions are the most common ophthalmologic manifestation of systemic lupus erythematosus (SLE), occurring in 3% to 29% of cases, generally late in the disease. More rare is the severe vaso-occlusive disease, often termed "retinal vasculitis", which includes central retinal artery occlusion, multifocal arteriolar occlusions, extensive capillary nonperfusion and central venous occlusion. Patients with SLE and raised serum concentrations of anticardiolipin antibodies (ACA) have a higher risk of developing occlusive ocular vascular disease. We report a case in which retinal involvement was an earlier manifestation of SLE in a patient without ACA.

Effects of liposome-mediated gene transfer of VEGF in ischemic rat gracilis muscle

The purpose of the current study was to determine the effects of vascular endothelial growth factor (VEGF) on muscle flap survival and vascularity in a rat gracilis ischemia-reperfusion model. A total of 12 adult male Wistar rats were divided into two groups (n = 6). The experimental group received the plasmid encoding VEGF(165) cDNA plus lipofectamine (cationic liposome) injected directly to the gracilis muscle following 4 h of ischemia. The control group received lipofectamine only. The viability and vascularity of the flaps were evaluated after 7 days of reperfusion. The data demonstrated that the VEGF plasmid- and lipofectamine-treated muscle flaps had significantly greater total survival and capillary count 7 days after reperfusion compared with the flaps treated only with lipofectamine. These results indicate that VEGF exerts a protective effect on ischemic skeletal muscle flaps.

SPIN90 (SH3 protein interacting with Nck, 90 kDa), an adaptor protein that is developmentally regulated during cardiac myocyte differentiation

In the yeast two-hybrid screening, we have isolated a cDNA clone from a human heart library using Nck Src homology 3 (SH3) domains as bait. The full-length cDNA, which encoded 722 amino acids, was identified as a VIP54-related gene containing an SH3 domain, proline-rich motifs, a serine/threonine-rich region, and a long C-terminal hydrophobic region. We refer to this protein as SPIN90 (SH3 Protein Interacting with Nck, 90 kDa). The amino acid sequence of the SH3 domain has the highest homology with those of Fyn, Yes, and c-Src. SPIN90 was broadly expressed in human tissues; in particular, it was highly expressed in heart, brain, and skeletal muscle, and its expression was developmentally regulated during cardiac myocyte differentiation. SPIN90 is able to bind to the first and third SH3 domains of Nck, in vitro, and is colocalized with Nck at sarcomere Z-discs within cardiac myocytes. Moreover, treatment with antisera raised against SPIN90 disrupted sarcomere structure, suggesting that this protein may play an important role in the maintenance of sarcomere structure and/or in the assembly of myofibrils into sarcomeres.

Limited use of cyclosporin A in skeletal muscle ischemia--reperfusion injury

Reperfusion injury is propagated by an inflammatory-mediated tissue edema and damage after reestablishment of vascular flow following an initial ischemic insult. In the field of transplantation, cyclosporin A(CsA) provides protection against chronic graft rejection through lymphocyte immunosuppression. Evidence for an independent protective effect of CsA against ischemia-reperfusion (IR) injury during organ transfer has prompted studies showing the benefit of CsA in various ischemia-exposed visceral organs. The authors hypothesized that CsA administration may similarly benefit IR injury after skeletal muscle amputations. To determine the effects of CsA on IR injury the authors induced 4 hours of ischemia on the gracilis muscle in a rat model. CsA (15 mg per kilogram orally) was administered in two experimental groups: (1) preischemic (N = 6): 48, 24, and 3 hours before ischemia; and (2) postischemic (N = 6): 30 minutes after induction of ischemia. The effects of CsA on IR muscle injury were observed in each of the experimental groups as well as a control group (N = 6) exposed to similar ischemia and administered a saline vehicle. Muscle viability (nitro blue tetrazolium staining) and muscle edema (wet-to-dry weight ratio) were assessed 24 hours after reperfusion. The preischemic CsA-treated gracilis muscle group demonstrated improved muscle viability (39.1 +/- 4.8%) when compared with the ischemic control muscle group (23.8 +/- 7.1%; p = 0.039). Furthermore, the preischemic CsA-treated muscle group demonstrated decreased edema (1.137 +/- 0.095 times the contralateral nonischemic muscle) when compared with the control ischemic muscle group (1.248 +/- 0.045 times the contralateral nonischemic muscle; p = 0.011). Although a trend toward improved muscle viability (32.1 +/- 4.2%) and decreased edema formation (1.200 +/- 0.062 times the contralateral nonischemic muscle) was observed in the peri-ischemic CsA-treated group when compared with the control ischemic muscle group, these differences were not significant. These observations confirm the beneficial effects of preischemic CsA therapy observed in organ transplantation research and suggest limited clinical use of peri-ischemic CsA therapy for patients with musculoskeletal amputations.

Wegener's granulomatosis presenting as mediastinal soft tissue mass invading the tracheal wall

Wegener's granulomatosis (WG) is a clinicopathologic entity of unknown cause characterised by a necrotising granulomatous vasculitis affecting multiple organs, especially the upper and lower respiratory tracts, lung and kidney. The lung is the most frequently, and sometimes the only involved organ. Single or multiple nodules, with or without cavitation, are the most common pulmonary manifestations in WG, but mediastinal involvement is atypical. The sole tracheal involvement is rare and hilar and mediastinal involvement has been thought not to be part of the clinical feature. We experienced a rare case of WG presenting as paratracheal mediastinal lesions with tracheal wall invasion, which responded dramatically to corticosteroid treatment. We present this case with a review of the literature.

Pro-apoptotic function of calsenilin/DREAM/KChIP3

Apoptotic cell death and increased production of amyloid b peptide (Ab) are pathological features of Alzheimer's disease (AD), although the exact contribution of apoptosis to the pathogenesis of the disease remains unclear. Here we describe a novel pro-apoptotic function of calsenilin/DREAM/KChIP3. By antisense oligonucleotide-induced inhibition of calsenilin/DREAM/KChIP3 synthesis, apoptosis induced by Fas, Ca2+-ionophore, or thapsigargin is attenuated. Conversely, calsenilin/DREAM/KChIP3 expression induced the morphological and biochemical features of apoptosis, including cell shrinkage, DNA laddering, and caspase activation. Calsenilin/DREAM/KChIP3-induced apoptosis was suppressed by caspase inhibitor Z-VAD and by Bcl-XL, and was potentiated by increasing cytosolic Ca2+, expression of Swedish amyloid precursor protein mutant (APPSW) or presenilin 2 (PS2), but not by a PS2 deletion lacking its C-terminus (PS2/411stop). In addition, calsenilin/DREAM/KChIP3 expression increased Ab42 production in cells expressing APPsw, which was potentiated by PS2, but not by PS2/411stop, which suggests a role for apoptosis-associated Ab42 production of calsenilin/DREAM/KChIP3.

Proapoptotic effects of tau cleavage product generated by caspase-3

Using an in vitro translation assay to screen a human brain cDNA library, we isolated the microtubule-associated protein Tau and determined it to be a caspase-3 substrate whose C-terminal cleavage occurred during neuronal apoptosis. DeltaTau, the 50-kDa cleavage product, was detected by Western blot in apoptotic cortical cells probed with anti-PHF-1 and anti-Tau-5 antibodies, but not anti-T-46 antibody which recognizes the C-terminus. Overexpression of DeltaTau in SK-N-BE2(C) cells significantly increased the incidence of cell death. Staurosporine-induced Tau cleavage was blocked by 20 microM z-Asp-Glu-Val-Asp-chloromethylketone, a caspase-3 inhibitor, and in vitro, Tau was selectively cleaved by caspase-3 or calpain, a calcium-activated protease, but not by caspases-1, -8, or -9. (D421E)-Tau, a mutant in which Asp421 was replaced with a Glu, was resistant to cleavage by caspase-3 and tended to suppress staurosporine-induced cell death more efficiently than did wild-type Tau in both transient and stable expression systems. Finally, the incidence of DeltaTau-induced cell death was augmented by expression of Abeta precursor protein (APP) or Swedish APP mutant. Taken together, these results suggest that the caspase-3 cleavage product of Tau may contribute to the progression of neuronal cell death in Alzheimer's disease.

[Determination of cholesterol in lipoprotein fractions by agarose gel electrophoresis]

OBJECTIVE

To evaluate a single step electrophoresis for quantitative determination of cholesterol of high-, low-, very-low-density lipoprotein(HDL, LDL, VLDL) and fast pre-beta lipoprotein [lipoprotein (a), Lp(a)].

METHODS

Quantification of lipoprotein cholesterol was performed by enzymatic staining of cholesterol in a new agarose gel electrophoresis method that allows the separation of LDL, VLDL, HDL, and Lp(a) by Helena REP system. The results of electrophoresis method were compared with those by traditional method like PTA-Mg2+ precipitation method for HDL-C, PVS precipitation method for LDL-C, and Immunoturbidimetric assay(ITA) method for Lp(a).

RESULTS

Within-runs CV were 5.16%-7.46%, 1.26%-3.28% and 3.78%-5.86% for VLDL-C, LDL-C and HDL-C, respectively. Between-runs CV were 8.35%-11.25%, 2.78%-4.08% and 4.23%-6.36%, respectively. The linearity of this method was up to 10.35 mmol/L total cholesterol. The recoveries were 90.3%, 94.3% and 89.6%, respectively. No interference were observed when bilirubin(< 342 mumol/L), hemoglobin(< 20 g/L) or triglyceride(< 11.0 mmol/L) were added to pooled serum, respectively. There was good agreement between methods, with r = 0.9557 for HDL-C(electrophoresis method vs PTA-Mg2+ precipitation method), r = 0.9609 for LDL-C(electrophoresis method vs PVS precipitation method) and r = 0.9235 for Lp(a)-C (electrophoresis method) vs Lp(a) (ITA method).

CONCLUSIONS

The electrophoresis method offers a simple and inexpensive means of simultaneously measuring HDL-C, VLDL-C, Lp(a)-C and LDL-C.

Inactivation of farnesyltransferase and geranylgeranyltransferase I by caspase-3: cleavage of the common alpha subunit during apoptosis

Caspase plays an important role in apoptosis. We report here that farnesyltransferase/geranylgeranyltransferase (FTase/GGTase)-alpha, a common subunit of FTase (alpha/beta(FTase)) and GGTase I (alpha/beta(GGTase)), was cleaved by caspase-3 during apoptosis. FTase/GGTase-alpha (49 kDa) was cleaved to 35 kDa (p35) in the Rat-2/H-ras, W4 and Rat-1 cells treated with FTase inhibitor (LB42708), anti-Fas antibody and etoposide, respectively. This cleavage was inhibited by caspase-inhibitors (YVAD-cmk, DEVD-cho). Serial N-terminal deletions and site-directed mutagenesis showed that Asp59 of FTase/GGTase-alpha was cleaved by caspase-3. The common FTase/GGTase-alpha subunit, but not the beta subunits, of the FTase or GGTase I protein complexes purified from baculovirus-infected SF-9 cells was cleaved to be inactivated by purified caspase-3. In contrast, FTase mutant protein complex [(D(59)A)alpha/beta(FTase)] was resistant to caspase-3. Expression of either the cleavage product (60-379) or anti-sense of FTase/GGTase-alpha induced cell death in Rat-2/H-ras cells. Furthermore, expression of (D(59)A)FTase/GGTase-alpha mutant significantly desensitized cells to etoposide-induced death. Taken together, we suggest that cleavage of prenyltransferase by caspase contributes to the progression of apoptosis.

Serine phosphorylation of p60 tumor necrosis factor receptor by PKC-delta in TNF-alpha-activated neutrophils

Tumor necrosis factor-alpha (TNF-alpha) triggers degranulation and oxygen radical release in adherent neutrophils. The p60TNF receptor (p60TNFR) is responsible for proinflammatory signaling, and protein kinase C (PKC) is a candidate for the regulation of p60TNFR. Both TNF-alpha and the PKC-activator phorbol 12-myristate 13-acetate triggered phosphorylation of p60TNFR. Receptor phosphorylation was on both serine and threonine but not on tyrosine residues. The PKC-delta isotype is a candidate enzyme for serine phosphorylation of p60TNFR. Staurosporine and the PKC-delta inhibitor rottlerin inhibited TNF-alpha-triggered serine but not threonine phosphorylation. Serine phosphorylation was associated with receptor desensitization, as inhibition of PKC resulted in enhanced degranulation (elastase release). After neutrophil activation, PKC-delta was the only PKC isotype that associated with p60TNFR within the correct time frame for receptor phosphorylation. In vitro, only PKC-delta, but not the alpha-, betaI-, betaII-, or zeta-isotypes, was competent to phosphorylate the receptor, indicating that p60TNFR is a direct substrate for PKC-delta. These findings suggest a selective role for PKC-delta in negative regulation of the p60TNFR and of TNF-alpha-induced signaling.

Surface topography of microtubule walls decorated with monomeric and dimeric kinesin constructs

The surface topography of opened-up microtubule walls (sheets) decorated with monomeric and dimeric kinesin motor domains was investigated by freeze-drying and unidirectional metal shadowing. Electron microscopy of surface-shadowed specimens produces images with a high signal/noise ratio, which enable a direct observation of surface features below 2 nm detail. Here we investigate the inner and outer surface of microtubules and tubulin sheets with and without decoration by kinesin motor domains. Tubulin sheets are flattened walls of microtubules, keeping lateral protofilament contacts intact. Surface shadowing reveals the following features: (i) when the microtubule outside is exposed the surface relief is dominated by the bound motor domains. Monomeric motor constructs generate a strong 8 nm periodicity, corresponding to the binding of one motor domain per alpha-beta-tubulin heterodimer. This surface periodicity largely disappears when dimeric kinesin motor domains are used for decoration, even though it is still visible in negatively stained or frozen hydrated specimens. This could be explained by disorder in the binding of the second (loosely tethered) kinesin head, and/or disorder in the coiled-coil tail. (ii) Both surfaces of undecorated sheets or microtubules, as well as the inner surface of decorated sheets, reveal a strong 4 nm repeat (due to the periodicity of tubulin monomers) and a weak 8 nm repeat (due to slight differences between alpha- and beta-tubulin). The differences between alpha- and beta-tubulin on the inner surface are stronger than expected from cryo-electron microscopy of unstained microtubules, indicating the existence of tubulin subdomain-specific surface properties that reflect the surface corrugation and hence metal deposition during evaporation. The 16 nm periodicity visible in some negatively stained specimens (caused by the pairing of cooperatively bound kinesin dimers) is not detected by surface shadowing.