Effect of air pollution-controlled residue of a sewage sludge incinerator on the drying shrinkage and the pore structure of alkali-activated materials

Recycling air pollution-controlled residues (APCR) generated from sewage sludge incinerators can be used for waste management, but the leaching of potentially toxic heavy metals from APCR poses environmental and human health issues. The present paper describes a procedure using APCR to produce alkali-activated materials and thereby realize their disposal. The effect of APCR on the compressive strength and drying shrinkage of the alkali-activated slag/glass powder was investigated. The pore structure characteristics were analyzed for clarifying its relationship with drying shrinkage. The results indicated that the drying shrinkage of the alkali-activated material was related to the mesopore volume. The drying shrinkage was slightly increased after the incorporation of the 10 % APCR, which was likely attributed to the high volume of mesopores compared to the 20 % APCR that lowered the drying shrinkage and compressive strength. This decrease in drying shrinkage was due to the recrystallization of sodium sulfate in the pore solution that can act as expansive agents and aggregates. The growth stress of the crystalline sodium sulfate within the matrix can offset the tension stress caused by the water loss. In addition, leaching studies using the SW-846 Method 1311 showed that recycling APCR into the alkali-activated system did not present a toxicity leaching risk or release unacceptable concentrations of heavy metals. The incorporation of waste APCR and waste glass can make AAMs a very promising and safe environmental technology.

The injury patterns, management and outcomes of retroperitoneal haemorrhage caused by lumbar arterial bleeding at a Level-1 Trauma Centre: A 10-year retrospective review

PURPOSE

Haemorrhagic shock remains a leading preventable cause of death amongst trauma patients. Failure to identify retroperitoneal haemorrhage (RPH) can lead to irreversible haemorrhagic shock. The arteries of the middle retroperitoneal region (i.e., the 1st to 4th lumbar arteries) are complicit in haemorrhage into the retroperitoneal space. However, predictive injury patterns and subsequent management implications of haemorrhage secondary to bleeding of these arteries is lacking.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients diagnosed with retroperitoneal haemorrhage who presented to our Level-1 Trauma Centre (2009-2019). We described the associated injuries, management and outcomes relating to haemorrhage of lumbar arteries (L1-4) from this cohort to assess risk and management priorities in non-cavitary haemorrhage compared to RPH due to other causes.

RESULTS

Haemorrhage of the lumbar arteries (LA) is associated with a higher proportion of lumbar transverse process (TP) fractures. Bleeding from branches of these vessels is associated with lower systolic blood pressure, increased incidence of massive transfusion, higher shock index, and a higher Injury Severity Score (ISS). A higher proportion of patients in the LA group underwent angioembolisation when compared to other causes of RPH.

CONCLUSION

This study highlights the injury patterns, particularly TP fractures, in the prediction, early detection and management of haemorrhage from the lumbar arteries (L1-4). Compared to other causes of RPH, bleeding of the LA responds to early, aggressive haemorrhage control through angioembolisation. These injuries are likely best treated in Level-1 or Level-2 trauma facilities that are equipped with angioembolisation facilities or hybrid theatres to facilitate early identification and management of thoracolumbar bleeds.

Advances in the use of recycled non-ferrous slag as a resource for non-ferrous metal mine site remediation

The growing global demand for non-ferrous metals has led to serious environmental issues involving uncovered mine site slag dumps that threaten the surrounding soils, surface waters, groundwater, and the atmosphere. Remediation of these slags using substitute cement materials for ordinary Portland cement (OPC) and precursors for alkali-activated materials (AAMs) can convert hazardous solid wastes into valuable construction materials, as well as to attain the desired solidification and stabilization (S/S) of heavy metal(loid)s (HM). This review discusses the current research on the effect of non-ferrous slags on the reaction mechanisms of the OPC and AAM. The S/S of HM from the non-ferrous slags in AAM and OPC is also reviewed. HM can be stabilized in these materials based on the complex salt effect and isomorphic effects. The major challenges faced in AAMs and OPC for HM stabilization include the long-term durability of the matrix (e.g., sulfate attack, stability of volume). The existing knowledge gaps and future trends for the sustainable application of non-ferrous slags are also discussed.

Muscle specific kinase protects dystrophic mdx mouse muscles from eccentric contraction-induced loss of force-producing capacity

KEY POINTS

Adeno-associated viral vector was used to elevate the expression of muscle specific kinase (MuSK) and rapsyn (a cytoplasmic MuSK effector protein) in the tibialis anterior muscle of wild-type and dystrophic (mdx) mice. In mdx mice, enhanced expression of either MuSK or rapsyn ameliorated the acute loss of muscle force associated with strain injury. Increases in sarcolemmal immunolabelling for utrophin and β-dystroglycan suggest a mechanism for the protective effect of MuSK in mdx muscles. MuSK also caused subtle changes to the structure and function of the neuromuscular junction, suggesting novel roles for MuSK in muscle physiology and pathophysiology.

ABSTRACT

Muscle specific kinase (MuSK) has a well-defined role in stabilizing the developing mammalian neuromuscular junction, but MuSK might also be protective in some neuromuscular diseases. In the dystrophin-deficient mdx mouse model of Duchenne muscular dystrophy, limb muscles are especially fragile. We injected the tibialis anterior muscle of 8-week-old mdx and wild-type (C57BL10) mice with adeno-associated viral vectors encoding either MuSK or rapsyn (a cytoplasmic MuSK effector protein) fused to green fluorescent protein (MuSK-GFP and rapsyn-GFP, respectively). Contralateral muscles injected with empty vector served as controls. One month later mice were anaesthetized with isoflurane and isometric force-producing capacity was recorded from the distal tendon. MuSK-GFP caused an unexpected decay in nerve-evoked tetanic force, both in wild-type and mdx muscles, without affecting contraction elicited by direct electrical stimulation of the muscle. Muscle fragility was probed by challenging muscles with a strain injury protocol consisting of a series of four strain-producing eccentric contractions in vivo. When applied to muscles of mdx mice, eccentric contraction produced an acute 27% reduction in directly evoked muscle force output, affirming the susceptibility of mdx muscles to strain injury. mdx muscles overexpressing MuSK-GFP or rapsyn-GFP exhibited significantly milder force deficits after the eccentric contraction challenge (15% and 14%, respectively). The protective effect of MuSK-GFP in muscles of mdx mice was associated with increased immunolabelling for utrophin and β-dystroglycan in the sarcolemma. Elevating the expression of MuSK or rapsyn revealed several distinct synaptic and extrasynaptic effects, suggesting novel roles for MuSK signalling in muscle physiology and pathophysiology.

[The impact of persistent high ambient fine particulate matters exposures on mortality in the 40 districts/counties of China, 2013-2015]

Objective: To investigate the impact of persistent high ambient fine particulate matters (PM(2.5)) exposures on mortality in the polluted areas of 40 districts/counties in China. Methods: Using a convenient sampling method, we selected 40 districts/counties as research sites from the Beijing-Tianjin-Hebei Metropolitan Region, the Yangtze River Delta, the Pearl River Delta, and Heilongjiang, Shanxi, and Sichuan province. The daily concentrations of PM(2.5), meteorological data and population death data from January 1, 2013 to December 31, 2015 were collected. The six persistent PM(2).5 pollution episode scenarios were defined by the average daily concentration of PM(2.5) (75 μg/m(3), P(75) and P(90) of the average daily concentration of each district/county respectively) and the duration (≥2 days or 3 days). Generalized linear models and meta analyses were used to explore the impact of PM(2.5) pollution episodes on mortality in 40 districts/counties. Results: The mean±SD and P(50) (P(25), P(75)) of average daily temperature, relative humidity and PM(2.5) were (15.26±10.48) ℃, 17.20 (7.50, 23.70) ℃, (67.31±19.26)%, 72.00% (57.00%, 81.00%), (72.81±60.93) μg/m(3) and 55.38 (33.77, 91.45) μg/m(3), respectively in 40 districts/counties during 2013-2015. The average number of non-accidental, cardiovascular and cerebrovascular diseases deaths per day were (12±7), (5±4) and (2±2) in each district/county, respectively. When the daily concentrations of PM(2.5) were ≥75 μg/m(3) (≥2 days), ≥P(75) (≥2 days), ≥P(90) (≥2 days), ≥75 μg/m(3) (≥3 days), and ≥P(75) (≥3 days), the excess risk (95%CI) of the total non-accidental deaths and cardiovascular diseases deaths were 1.77% (0.89%,2.66%), 2.69% (1.06%,4.35%), 1.67% (0.59%,2.76%), 2.31% (0.67%, 3.97%), 0.71% (-0.75%, 2.20%), 1.95% (0.08%, 3.86%), 1.15% (0.12%, 2.18%), 1.85% (0.25%, 3.47%), 1.39% (0.15%, 2.64%), 2.29% (0.39%, 4.23%), respectively. Conclusion: Persistently high PM(2.5) exposures were associated with total non-accidental deaths and cardiovascular disease deaths.

Acute effect of multiple ozone metrics on mortality by season in 34 Chinese counties in 2013-2015

BACKGROUND

Although numerous multicentre studies have estimated the association between ozone exposure and mortality, there are currently no nationally representative multicentre studies of the ozone-mortality relationship in China.

OBJECTIVE

To investigate the effect on total (nonaccidental) and cause-specific mortality of short-term exposure to ambient ozone, and examine different exposure metrics.

METHODS

The effects of short-term exposure to ozone were analysed using various metrics (daily 1-h maximum, daily 8-h maximum and daily average) on total (nonaccidental) and cause-specific (circulatory and respiratory) mortality from 2013 to 2015 in 34 counties in 10 cities across China. We used distributed lag nonlinear models for estimating county-specific relative risk of mortality and combined the county-specific relative rates by conducting a random-effects meta-analysis.

RESULTS

In all-year analyses, a 10 μg m^-3 increase in daily average, daily 1-h maximum and daily 8-h maximum ozone at lag02 corresponded to an increase of 0.6% (95% CI: 0.33, 0.88), 0.26% (95% CI: 0.12, 0.39) and 0.37% (95% CI: 0.2, 0.55) in total (nonaccidental) mortality, 0.66% (95% CI: 0.28, 1.04), 0.31% (95% CI: 0.11, 0.51) and 0.39% (95% CI: 0.16, 0.62) in circulatory mortality, and 0.57% (95% CI: -0.09, 1.23), 0.11% (95% CI: -0.22, 0.44) and 0.22% (95% CI: -0.28, 0.72) in respiratory mortality, respectively. These estimates had a different seasonal pattern by cause of death. In general, the seasonal patterns were consistent with the times of year when ozone concentrations are highest.

CONCLUSIONS

Our findings suggest that in China, the acute effects of ozone are more closely related to daily average exposure than any other metric.

Combined Treatment of 4′-EPI-Doxorubicin and Radiation on Hamster Lung Cells

The purpose of this study was to test the type and the degree of cytotoxic effects of epirubicin and radiation in combined treatment on Chinese hamster lung cells in vitro. Experiments were performed with proliferating tissue culture cells. Cell kill was determined by colony-forming ability. The maximum killing effects were obtained when simultaneous action of drug treatment and irradiation occurred. Their interaction was synergistic. Synergism depended on time of drug incubation (epirubicin present for 1 h). Slight antagonism was noted after prolonged drug action (24 h).

[A review on the research progress related to ambient air pollution and depression]

It is reported that depression has caused heavy disease burden across the world, with an possible association between ambient air pollution and depressive symptoms. In this paper, we reviewed relative literature in this field and summarized the research events on association between ambient air pollution and depression, both in China and abroad and found that the results of the existed studies were inconsistent, with most studies showing that there existed a positive correlation between the exposure of air pollution and depression, but few studies showing the negative correlation or no correlation between the two.

The determination and application of (87) Sr/(86) Sr ratio in verifying geographical origin of wheat

As ⁸⁷ Sr/⁸⁶ Sr ratio plays a significant role in authenticating the geographical origin of foodstuff, it is important to identify where the ⁸⁷ Sr/⁸⁶ Sr signature in food comes from, and the methods of ⁸⁷ Sr/⁸⁶ Sr ratio analysis in food and environmental samples. Wheat with three genotypes, soil and groundwater samples were collected from three regions of China during harvest time of 2014. The ⁸⁷ Sr/⁸⁶ Sr ratios in the samples were determined by thermal ionization mass spectrometer in order to investigate the possible source of ⁸⁷ Sr/⁸⁶ Sr in wheat, and the concentrations of Rb and Sr in wheat and soils were also detected by inductively coupled plasma mass spectrometry and combined with ⁸⁷ Sr/⁸⁶ Sr ratio in order to trace the geographical origin of wheat. The ⁸⁷ Sr/⁸⁶ Sr ratio, the contents Rb and Sr, and Rb/Sr ratio of wheat and soil samples showed significant differences among three regions. The ⁸⁷ Sr/⁸⁶ Sr ratios and the concentrations of Rb and Sr in soils were higher than those in corresponding wheat. The ⁸⁷ Sr/⁸⁶ Sr ratio in wheat was identical to that corresponding soil NH₄ NO₃ extracts (labile fraction of soil) and groundwater. Wheat uptake more Rb than Sr. 3D distribution of ⁸⁷ Sr/⁸⁶ Sr, Rb and Sr could identify wheat samples from different regions clearly. The ⁸⁷ Sr/⁸⁶ Sr ratio of wheat reflects the ⁸⁷ Sr/⁸⁶ Sr ratio of the associated environment including soil and groundwater. It is expected that the use the parameters of ⁸⁷ Sr/⁸⁶ Sr ratio, the contents of Rb and Sr will allow to trace geographical origin of wheat. Copyright © 2017 John Wiley & Sons, Ltd.

Nitric oxide participates in IFN-gamma-induced HUVECs hyperpermeability

The endothelial barrier function is tightly controlled by a broad range of signaling cascades including nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. It has been proposed that disturbances in NO and cGMP production could interfere with proper endothelial barrier function. In this study, we assessed the effect of interferon-gamma (IFN-gamma), a pro-inflammatory cytokine, on NO and cGMP levels and examined the mechanisms by which NO and cGMP regulate the IFN-gamma-mediated HUVECs hyperpermeability. The flux of fluorescein isothiocyanate-labeled dextran across cell monolayers was used to study the permeability of endothelial cells. Here, we found that IFN-gamma significantly attenuated basal NO concentration and the increased NO levels supplied by a NO donor, sodium nitroprusside (SNP). Besides, application of IFN-gamma also significantly attenuated both the basal cGMP concentration and the increased cGMP production donated by a cell permeable cGMP analogue, 8-bromo-cyclic GMP (8-Br-cGMP). In addition, exposure of the cell monolayer to IFN-gamma significantly increased HUVECs basal permeability. However, L-NAME pretreatment did not suppress IFN-gamma-induced HUVECs hyperpermeability. L-NAME pretreatment followed by SNP or SNP pretreatment partially reduced IFN-gamma-induced HUVECs hyperpermeability. Pretreatment with a guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY83583), led to a further increase in IFN-gamma-induced HUVECs hyperpermeability. The findings suggest that the mechanism underlying IFN-gamma-induced increased HUVECs permeability is partly related to the inhibition of NO production.

A comparison of computer- and hand-generated clinical dental notes with statutory regulations in record keeping

INTRODUCTION

Dental patient records should be of high quality, contain information to allow for good continuity of care and clinical defence (should the need ever arise) and, ideally, facilitate clinical audit. Handwritten dental records have been assessed for their compliance to statutory regulations, but the same cannot be levelled at computer-generated notes. This study aimed to compare and analyse the compliance of both methods of data recording with statutory regulations.

METHOD

Fifty consecutive sets of handwritten notes and 50 sets of computer-generated notes were audited for compliance with a number of legal requirements and desirable characteristics for dental records and the results compared. The standard set for compliance with all characteristics was 100%.

RESULTS

The computer-generated notes satisfied the set standard for 8 of the 11 legal requirements and three of six desirable characteristics. The handwritten notes satisfied the set standard for 1 of 11 legal requirements and none of the desirable characteristics. A statistical difference (using a 95% confidence interval) between the two methods was observed in 5 of 11 legal characteristics and three of six desirable characteristics, all of which were in favour of computer-generated notes.

CONCLUSIONS

Within the limitations of this study, computer-generated notes achieved a much higher compliance rate with the set parameters, making defence in cases of litigation, continuity of care and clinical audit easier and more efficient.

Hsa-mir-145 is the top EWS-FLI1-repressed microRNA involved in a positive feedback loop in Ewing's sarcoma

EWS-FLI1 is a chromosome translocation-derived chimeric transcription factor that has a central and rate-limiting role in the pathogenesis of Ewing's sarcoma. Although the EWS-FLI1 transcriptomic signature has been extensively characterized on the mRNA level, information on its impact on non-coding RNA expression is lacking. We have performed a genome-wide analysis of microRNAs affected by RNAi-mediated silencing of EWS-FLI1 in Ewing's sarcoma cell lines, and differentially expressed between primary Ewing's sarcoma and mesenchymal progenitor cells. Here, we report on the identification of hsa-mir-145 as the top EWS-FLI1-repressed microRNA. Upon knockdown of EWS-FLI1, hsa-mir-145 expression dramatically increases in all Ewing's sarcoma cell lines tested. Vice versa, ectopic expression of the microRNA in Ewing's sarcoma cell lines strongly reduced EWS-FLI1 protein, whereas transfection of an anti-mir to hsa-mir-145 increased the EWS-FLI1 levels. Reporter gene assays revealed that this modulation of EWS-FLI1 protein was mediated by the microRNA targeting the FLI1 3'-untranslated region. Mutual regulations of EWS-FLI1 and hsa-mir-145 were mirrored by an inverse correlation between their expression levels in four of the Ewing's sarcoma cell lines tested. Consistent with the role of EWS-FLI1 in Ewing's sarcoma growth regulation, forced hsa-mir-145 expression halted Ewing's sarcoma cell line growth. These results identify feedback regulation between EWS-FLI1 and hsa-mir-145 as an important component of the EWS-FLI1-mediated Ewing's sarcomagenesis that may open a new avenue to future microRNA-mediated therapy of this devastating malignant disease.

A small nuclear RNA, hdm365, is the major processing product of the human mdm2 gene

mdm2 encodes for an E3 ubiquitin ligase targeting constitutively expressed p53 for proteasomal degradation. Several protein isoforms have been described for human MDM2 (HDM2), some of which may correspond to splicing variants detectable by RT-PCR in many tumors. Upon cellular stress, p53 becomes resistant to MDM2 and, in a feedback loop, up-regulates mdm2 transcription. The physiological relevance of stress-induced mdm2 gene activity is not well understood. We describe a small nuclear RNA of 365 bases comprised of the first five hdm2 exons and lacking polyadenylation. hdm365 precedes full-length hdm2 RNA expression after induction by p53 and accumulates to significant levels in the nucleus, detectable at the site of hdm2 transcription and processing only. Considering a 10-fold lower stability and high steady-state levels of the novel RNA species, hdm365 appears to be the major processing product of hdm2 transcripts. hdm365 induction was observed after ectopic expression of p53 and after DNA damaging treatment of tumor cell lines, primary fibroblasts and lymphocytes, and was not related to apoptosis. Corresponding truncated transcripts were observed in hdm2 amplified cells. High stress-inducible expression levels, absence of a corresponding protein, and nuclear localisation of hdm365 suggest a novel RNA-based function for hdm2.

Alternative splicing of caspase-8 mRNA during differentiation of human leukocytes

Caspase-8 is a key initiator of death receptor-induced apoptosis. Here we provide evidence that caspase-8 expression is subject to posttranscriptional regulation in human leukocytes. Resting peripheral blood lymphocytes preferentially use a distant splice donor site at the 3'-end of caspase-8 exon 8 to generate mRNAs with a truncated open reading frame. When lymphocytes were activated, the expression of caspase-8 variants was shifted to caspase-8/a and b which lack the extension of exon 8. The opposite change of the splicing pattern was found in a neutrophil differentiation model. Promyelocytic HL-60 cells mainly expressed caspase-8 mRNAs with the normal exon 8, but the splicing pattern was changed to the distant exon 8 splice site during DMSO-induced differentiation of HL-60 cells. In spite of the presence of these novel mRNAs, the corresponding translation products were not detectable in either cell type. Our findings suggest that leukocyte differentiation and alternative splicing of caspase-8 pre-mRNA are inter-dependent processes.

Terminal differentiation of human keratinocytes and stratum corneum formation is associated with caspase-14 activation

Programmed cell death of epidermal keratinocytes (KC) results in the formation of cornified cells, which constitute the outermost skin layer, the stratum corneum. Here we show by reverse transcription-polymerase chain reaction, western blot, and immunohistochemistry that epidermal KC express caspase-14, a member of the caspase family of pro-apoptotic proteases, in a tissue-specific manner. Caspase-14 protein abundance strongly increases during terminal differentiation of KC in vivo and in vitro. Under conditions that lead to stratum corneum formation caspase-14 cleavage products, which indicate proenzyme activation, appeared in the KC lysates. Cleavage of the enzyme was also detected in lysates from normal human epidermis and in extracts of stratum corneum. Our findings demonstrate that caspase-14 is activated during KC differentiation and strongly suggest that it is involved in the formation of the human skin barrier.J Invest Dermatol 115:1148-1151 2000

Molecular mechanisms involved in the antiproliferative action of protein tyrosine phosphatase inhibitor potassium bisperoxo(1,10-phenanthroline)oxovanadate

Potassium bisperoxo(1,10-phenanthroline)oxovanadate, bpV(phen), a powerful protein phosphotyrosine phosphatase inhibitor and a potent insulinomimetic, influenced three fundamental cellular processes in HL-60 human leukemic cells: 1) inhibition of proliferation, 2) induction of differentiation and 3) apoptotic cell death. In the presence of micromolar concentrations of bpV(phen) cell number and DNA synthesis decreased progressively with time of incubation. A single treatment with bpV(phen) (3 microM) activated a differentiation program; after 6 days of incubation 82% of cells were differentiated, but differentiation started already within the first 24 h. Concentrations of 5-10 microM bpV(phen) caused the characteristic DNA ladder pattern, starting after 4.5 h. Differentiation in HL-60 cells appear to be associated with activation of extracellular signal-regulated kinase while apoptosis is connected with phosphorylation and activation of both extracellular signal-regulated kinase and c-Jun N-terminal kinase in a concentration and time-dependent manner. The antiproliferative and apoptotic action of bpV(phen) could be exploited in combination chemotherapy in leukemia.

Caspase-14: analysis of gene structure and mRNA expression during keratinocyte differentiation

Caspase-14 is expressed in a tissue-specific manner in mouse skin. Here we determined the complete caspase-14 cDNA sequence of human caspase-14 by rapid amplification of cDNA ends. Sequence comparison with a cosmid clone containing genomic DNA revealed that the human caspase-14 gene comprises seven exons. Facultative utilization of a cryptic splice acceptor site within intron 5 leads to the formation of two mRNA species. In situ hybridization of human skin showed that caspase-14 is expressed in the uppermost layer of living epidermal cells, i.e., the granular layer, in hair follicles and sebaceous glands. In vitro caspase-14 transcription was low in subconfluent cultures but strongly increased when keratinocyte differentiation was simulated by maintaining cells at confluence for several days. This transcriptional upregulation was suppressed in the presence of a high extracellular calcium concentration. Our findings show that caspase-14 is regulated at the level of transcription during keratinocyte differentiation in vitro and in vivo.

Keratinocytes express the CD146 (Muc18/S-endo) antigen in tissue culture and during inflammatory skin diseases

The CD146 (or MUC18/MEL-CAM) antigen is a cell adhesion molecule of the immunoglobulin superfamily. Besides in melanoma, expression of CD146 antigen has been demonstrated in breast epithelia and hair follicles. We studied its expression by human keratinocytes in culture as well as in neoplastic and inflammatory skin diseases. Staining of primary cultured keratinocytes revealed expression of CD146 on the cell membrane, preferentially on cell-cell contact sites. Western blot analysis of keratinocytes detected a band of approximately 113 kDa, corresponding to the CD146 protein. In contrast to primary keratinocytes, neither CD146 protein nor mRNA expression was found in the keratinocyte-derived cell lines A431 and HaCaT. Treatment of keratinocytes with the proinflammatory cytokines interleukin-1 and interleukin-6, tumor necrosis factor-alpha, and interferon-gamma, resulted in no change of CD146 expression and incubation with phorbol 12-myristate 13-acetate led to a reduction of CD146 on keratinocytes. By contrast, when culturing keratinocytes in medium devoid of growth supplements, a distinct upregulation was observed as compared with culture in fully supplemented medium. In normal human epidermis expression of the CD146 antigen was not detectable. It was strongly upregulated, however, on suprabasal keratinocytes in psoriasis, in lichen planus, in the epidermis overlying skin neoplasms, and in viral warts. In squamous cell carcinomas and basal cell carcinomas only a minority of tumor cells expressed CD146. Our findings suggest that the CD146 antigen represents an activation marker of keratinocytes and may be involved in cutaneous inflammatory tissue reaction.

Melanin binds reversibly to thermostable DNA polymerase and inhibits its activity

We found that both RNA and cDNA preparations derived from melanocytes contain a RT-PCR inhibitor that copurified with nucleic acids. Investigation of the candidate inhibitor melanin revealed that it potently blocks PCR at concentrations below 200 ng/ml, whereas 100 microg/ml melanin was required to inhibit reverse transcription. Melanin and thermostable DNA polymerase preferentially formed a distinct complex with reduced migration velocity as compared to pure polymerase in nondenaturating polyacrylamide gel electrophoresis. The inhibition of the enzyme by melanin could be reversed by diluting solutions of preformed complexes or by adding excess amounts of other proteins such as bovine serum albumin or dry milk. Our findings demonstrate that melanin is a potent inhibitor of thermostable DNA polymerase in vitro and that the inhibitory effect is conferred by a direct and reversible polymerase-melanin interaction.

Characterization of a cDNA clone, encoding a 70 kDa heat shock protein from the dermatophyte pathogen Trichophyton rubrum

Trichophyton rubrum is an anthropophilic fungus causing up to 90% of chronic cases of dermatophytosis. To characterize T. rubrum proteins at the molecular level, we established a cDNA library of this pathogen. Here we describe a recombinant cDNA clone identical to eukaryotic 70kDa heat-shock proteins (HSPs). Western blot analysis using an anti HSP70 monoclonal antibody detected a recombinant fusion protein in Escherichia coli transformed with the expression vector containing the cloned cDNA insert. Southern blot analysis of T. rubrum genomic DNA detected no other members of the HSP70 gene family. Further analysis revealed the presence of two introns within the ORF of the HSP70 gene. In Northern blot analysis, the cDNA clone was hybridized to a RNA species of about 3.5kb which was constitutively expressed by cells cultured at 27 degrees C and was strongly up-regulated after culture at 37 degrees C. In summary, we have cloned the first member of the HSP family of dermatophytes and characterized it as a member of the Dnak subfamily of 70kDa HSPs.

The human homologue of the bovine leukemia virus receptor BLVRcp1 is the delta-subunit of adaptor-related AP-3 protein that does not bind the BVLgp51

The relationship between the putative bovine leukemia virus receptor gene (BVLRcp) and the susceptibility of human cells to BLV infection was studied. Three cDNA clones encoding different portions of the human equivalent of bovine BLVRcp1 were isolated by DNA-DNA hybridization by comparison of the human cDNA clones to bovine BLVRcp1. Amino acid sequence indicated that the human sequence encodes the delta subunit of the AP-3 adaptor-related protein. When the recombinant human homologue BLVRcp2 was expressed in E. coli, it failed to bind the BLVgp51. However, the BVLVgp51 binding ability was restored when the chimerical BLVRcp molecule was prepared by exchanging 5' ends between bovine and human BLVRcp cDNAs. This finding implies that this BLVgp51 binding site is present only on the bovine BLVRcp and therefore its human homologue cannot be recognized by BLVgp51. This might also explain the resistance of human cells to BLV infection.

The cell death regulatory protein bak is expressed in endothelial cells in inflamed tissues and Is induced by IFN-gamma in vitro

In the present report, we examined the endothelial expression of the anti- and pro-apoptotic proteins Bcl-2 and Bak in situ and in vitro. Endothelial cells (EC) in regular tissue of the bowel and the skin were essentially negative for both Bcl-2 and Bak. In contrast, EC within the walls of fistulas and abscesses in these organs stained distinctly for Bak, but remained Bcl-2-negative. In tissue culture both unstimulated human dermal microvascular endothelial cells (HDMEC) and human umbilical vein endothelial cells (HUVEC) expressed Bcl-2 and Bak constitutively. Exposure of EC to 200-1000 IU IFN-gamma downregulated Bcl-2 but upregulated Bak. This opposing regulation of Bcl-2 and Bak in vitro and the expression of Bak in EC adjacent to necrotic tissue areas suggests that this pro-apoptotic protein may play a decisive role in regulation of EC survival in vivo.

UVA and UVB radiation differentially regulate vascular endothelial growth factor expression in keratinocyte-derived cell lines and in human keratinocytes

Vascular endothelial growth factor (VEGF) is a central regulator of neoangiogenesis in inflammatory and neoplastic conditions. Ultraviolet irradiation is one of the mainstays of dermatological therapy for various inflammatory skin diseases. In the present study we have compared the effects of UV irradiation on the production of VEGF by keratinocytes (KC) and by the KC-derived cell lines A431 and HaCaT. Irradiation of A431 and HaCaT cells with both UVA (10 J/cm2 and 20 J/cm2) and UVB (8 mJ/cm2 and 16 mJ/cm2) led to strong upregulation of VEGF mRNA and protein. Induction of VEGF by UVA and UVB in these cells was mediated by different pathways, i.e. the generation of free radicals and the secretion of (a) soluble factor(s), respectively. Unlike KC-derived cell lines, no increase in VEGF production was observed in KC in primary culture after irradiation with the same UV doses. Increasing the irradiation dose in these cells of UVA to 40 J/cm2 led to a marked decrease in soluble VEGF, whereas doses as high as 32 mJ/cm2 UVB only minimally affected VEGF levels. Reduction of VEGF production by KC might contribute to the effect of UVA irradiation in inflammatory skin diseases. The differential response of primary KC and autonomously growing KC-derived cell lines to the induction of VEGF by UV light could favor neoangiogenesis in the vicinity of epidermal tumor cells in vivo, thereby endowing them with a growth advantage over normal cells.

Activation of MAPK by potassium bisperoxo(1,10-phenanthroline)oxovanadate (V)

Potassium bisperoxo(1,10-phenantroline)oxovanadate (V) [bpV(phen)] is a potent protein tyrocine phosphatase inhibitor which mediates a variety of biological effects. The aim of these studies was to examine the role(s) of mitogen activated protein kinase (MAPK) pathways in PC12 cell proliferation and toxicity by bpV(phen). BpV(phen) exerts a bimodal effect in PC12 cells: proliferation at low and cell death at higher micromolar concentrations. Activation of MAPK by bpV(phen) depends on time and concentration. The phosphorylation pattern of extracellular regulated kinases (ERK 1/2), c-jun N-terminal activated kinases (JNK) and p38 in PC12 cells is strikingly different. Activation of JNK is sustained in PC12 cells. In contrast, ERK 1/2 activation is transient and treatment with PD98059 indicates that ERK activation by bpV(phen) is partly independent from the ras-MEK pathway. Stability studies of bpV(phen) in DMEM and PBS showed linear relationship with T1/2 about 6 h and 10 days in DMEM and PBS, respectively. Comparison between the time courses of MAPK activation and kinetics of bpV(phen) decomposition as assessed by 51V-NMR analysis show that the initial and maximal phosphorylation signals are produced in the presence of the complex bpV(phen) and not caused by the decomposition products of bpV(phen).

Reverse transcription-polymerase chain reaction products of alternatively spliced mRNAs form DNA heteroduplexes and heteroduplex complexes

Reverse transcription-polymerase chain reaction (RT-PCR) is frequently used to simultaneously detect mRNA isoforms, which are generated by alternative splicing. Here we characterize two previously unrecognized RT-PCR products of vascular endothelial growth factor (VEGF) RNA. DNA products with apparent sizes of 600 and 1200 base pairs (bp) were detected at high cycle numbers. Heat denaturation of the smaller product and subsequent reannealing revealed that it was a heteroduplex consisting of two different DNA strands. These were identified by DNA sequencing as the amplification products of two VEGF transcripts, i.e. VEGF121 and VEGF165, which differ by the presence of one exon. S1 nuclease analysis showed that this exon is bulged out as a single-stranded loop. Purified heteroduplexes in solution were found to form a 1200-bp DNA product which could be reconverted into 600-bp DNA heteroduplexes by mild denaturation at 70 degreesC. These findings suggest that this product is formed by base pairing of complementary heteroduplex loops and represents a novel four-stranded DNA structure.

Identification of a human cDNA encoding a novel Bcl-x isoform

Alternative splicing has been shown to generate two isoforms of the apoptosis regulator bcl-x, Bcl-xL and Bcl-xS, in humans. Here we describe the identification and characterization of a third splice variant of the human bcl-x gene. It differs from previously described bcl-x transcripts in two respects: (1) a novel facultative intron is spliced out at the 5' untranslated region and (2) the open reading frame arises from a continuous genomic sequence extending over the splice donor sites utilized by the bcl-xL and bcl-xS transcripts. Since the resulting molecule has an organisation homologous to mouse and rat Bcl-x beta we suggest calling this novel protein human Bcl-x beta. Northern blot analysis revealed that bcl-x beta mRNA is expressed in numerous cell lines. Like Bcl-xL, h-Bcl-x binds to the pro-apoptotic protein Bax, suggesting a functional activity in vivo.

Polyclonal bovine sera but not virus-neutralizing monoclonal antibodies block bovine leukemia virus (BLV) gp51 binding to recombinant BLV receptor BLVRcp1

Bovine leukemia virus (BLV), a transactivating lymphotropic retrovirus, is the etiologic agent of enzootic lymphosarcoma or leukemia in cattle. Sera from BLV-infected animals possess high BLV-neutralizing antibody titres. The availability of the recombinant BLV receptor candidate, BLVRcp1, allowed us to determine a mechanism of virus neutralization by polyclonal sera and monoclonal antibodies (MAbs). Bovine sera from animals naturally infected with BLV blocked gp51 binding to recombinant BLVRcp1. In contrast, virus-neutralizing MAbs specific for gp51 F, G, and H epitopes did not prevent gp51-receptor attachment. Furthermore, gp51 neutralization epitopes F, G, and H were accessible to antibodies following gp51 attachment to BLVRcp1. This finding implies that virus neutralization by MAbs to defined BLV gp51 epitopes can occur subsequent to virus engagement of the receptor while polyclonal sera can specifically block virus attachment to the receptor. In conclusion, these data suggest that cell infection by BLV is a multistep process requiring receptor binding (inhibited by polyclonal sera) followed by a second, postbinding event(s) at the cell membrane (inhibited by anti-gp51 MAbs).

Chromosomal localization of the BLV receptor candidate gene in cattle, sheep, and goat

The BLV receptor candidate gene has been localized precisely on cattle, goat, and sheep chromosomes using nonradioactive in situ hybridization and simultaneous fluorescent R-banding. The probe, a whole plasmid containing a 2.3-kb bovine cDNA fragment encoding part of this gene, was nick-translated in the presence of biotin-11-dUTP. It hybridized on band q15 of cattle chromosome 7, goat chromosome 7, and sheep chromosome 5, thus confirming the homoeology based on banding patterns among the chromosomes of these three species.

Isolation of the missing 5'-end of the encoding region of the bovine leukemia virus cell receptor gene

The missing 5'-end of the encoding region of the bovine leukemia virus (BLV) cell receptor gene (BLVRcp1/5') was isolated from a lambda gt11 cDNA library using the 32P-labeled EcoRI-SamI fragment corresponding to the 5'-end of a 2.3 kbp cDNA fragment encoding the binding domain of the bovine leukemia virus cell receptor gene (BLVRcp1). The nucleotide and amino acid sequence analysis of the BLVRcp1/5' cDNA revealed that the 1058 bp EcoRI fragment at its 5'-end contained a new 114 amino acid long sequence, and at its 3'-end contained a completely identical 88 amino acid overlapping region with the 5'-end of the BLVRcp1 cDNA. The combined sequences of both cDNAs represent the whole encoding region of the BLV cell receptor gene. The longest open reading frame of the BLV cell receptor gene encodes a protein containing 843 amino acids with a calculated molecular mass of 94.2 kDa which concurs with experimentally detected native BLV receptor protein. Search for homology has shown that about 250 bp of the BLV cell receptor gene is highly homologous to Venter's tag sequences of an unidentified gene from the human brain library.

Isolation and characterization of a 2.3-kilobase-pair cDNA fragment encoding the binding domain of the bovine leukemia virus cell receptor

An immunoscreening strategy was used to isolate a cDNA clone encoding the binding domain for the external glycoprotein gp51 of the bovine leukemia virus (BLV). Three recombinant phages demonstrating BLV binding activity and containing 2.3-kbp cDNA inserts with identical nucleotide sequences were isolated from a lambda gt11 cDNA library of bovine kidney cells (MDBK). One clone, BLVRcp1, hybridized with a 4.8-kb mRNA from cells of bovine origin and was also found to be conserved as a single-copy gene in murine, bovine, ovine, primate, canine, feline, and porcine DNAs. The same gene is amplified in caprine DNA isolated from a BLV-induced tumor. The longest open reading frame of BLVRcp1 encodes a protein fragment of 729 amino acids with a putative receptor structure. BLVRcp1 cDNA was cloned in the eucaryotic expression vector pXT-1 and transfected into murine NIH 3T3 and human HEp-2 cells. Cells expressing BLVRcp1 mRNA became susceptible to BLV infection. BLVRcp1 has no known physiological function and has no significant homology with sequences registered in the GenBank and EMBL data libraries (31 July 1992). Expression of deleted constructs of BLVRcp1 indicates that the BLV binding region is encoded at the 5' side of the receptor clone.

Two immunodominant regions revealed by monoclonal antibodies on the main structural protein p24 of bovine leukemia virus

Eleven different monoclonal antibodies (Mabs) directed against the main structural protein p24 of bovine leukemia virus (BLV) were prepared. All Mabs reacted with p24 in Western blot and in radioimmunoprecipitation. Competition antibody binding assays with the prepared Mabs distinguished three independent groups of Mabs. Two immunodominant regions (IDRs) of p24 BLV were defined by these Mabs. The Mabs were induced preferentially against two immunodominant regions on the native form of p24 BLV (BLVp24 IDR-1 and BLVp24 IDR-2). Mab of the third group was directed against a different immunogenic epitope of p24 BLV. A model of the IDRs based on the differences in the fine epitope specificity of Mabs defining these immunodominant regions is proposed.

Evaluation of DNA probe removal from nylon membrane

Genetic fingerprinting is one of the most challenging applications of any hybridization membranes. Forensic DNA fingerprinting typically uses samples in the range of 100-400 ng of genomic DNA. To ensure the ability to successfully reprobe the samples, it is imperative that repeated stripping of sample DNA be minimized while stripping of the probe DNA be maximized. By using standard dilutions of K562 cell line, we compared the following three stripping techniques: NaOH at 25 degrees C, formamide (HCONH2) at 65 degrees C and 0.1 x standard saline citrate and 0.1% sodium dodecyl sulfate at 95 degrees C (high-temperature stripping). The largest amount of genomic DNA was stripped from the membrane with NaOH, with the other two techniques removing less. Formamide and high-temperature procedures resulted in a loss of approximately 5-10 ng of DNA per strip. In contrast, the NaOH resulted in a loss of approximately 10-20 ng per strip.

Mapping of sequential epitopes recognized by monoclonal antibodies on the bovine leukaemia virus external glycoproteins expressed in Escherichia coli by means of antipeptide antibodies

A lambda gt11 cDNA library prepared from bovine leukaemia virus (BLV)-producing ovine cells was screened with a cocktail of anti-BLV gp51 monoclonal antibodies (MAbs). Four recombinant phages with inserts of about 2-5 kbp were isolated. One, lambda BLV-gp51-1, was sequenced and shown to encode the C-terminal part of gp51 and all of gp30. This insert was subcloned into pEV-vrf1 and expressed in Escherichia coli N-4830-1 cells. The BLV product and a series of antipeptide antibodies were used to localize the sequential epitopes defined on BLV envelope glycoprotein gp51 by their reactivity with MAbs. Epitope B was localized to amino acids 180 to 205, B' to residues 195 to 205, D and D' to residues 218 to 237, and A to amino acids 249 to 260. All the mapped sequential epitopes were localized in the C-terminal half of BLV gp51. The results of epitope mapping with bacterially produced gp51 confirm the map obtained using native viral glycoprotein.

Synergistic action of tiazofurin and difluorodeoxycytidine on differentiation and cytotoxicity

Tiazofurin (TR), an inhibitor of IMP dehydrogenase, causes remissions and induced differentiation in human leukemia through lowering the concentrations of GTP and dGTP. A deoxycytidine analog, difluorodeoxycytidine (DFDC), is an anti-tumor agent phosphorylated by deoxycytidine kinase, resulting in decreased concentration of dCTP, leading to inhibition of DNA synthesis. In HL-60 cells DFDC induced differentiation and inhibited proliferation in a dose-dependent manner (IC50 = 4 nM); TR provided synergism with DFDC. DFDC inhibited proliferation in OVCAR-5 human ovarian carcinoma cells (IC50 = 25 nM) and colony formation in PANC-1 human pancreatic carcinoma cells (IC50 = 2 nM) and rat hepatoma 3924A cells (IC50 = 22 nM). TR and DFDC are synergistically cytotoxic in hepatoma cells and additive in PANC-1 cells. The two drugs together should be helpful in treating leukemias and solid tumors in humans.

The oligosaccharides in a recombinant hepatitis B virus surface antigen (HBsAg) carrying the pre-S2 region derived from yeast

The N- and O-linked oligosaccharides in a yeast-derived HBsAg M protein (pre-S2 + S) were analyzed. Two major structures of the N-linked oligosaccharides bound to residue Asn4 were determined to be high-mannose type oligosaccharides, Man7GlcNAc2 and Man8GlcNAc2, by two-dimensional sugar mapping of the corresponding pyridylamino oligosaccharides. Peptide mapping of the M protein, sequence analysis of the glycopeptides after beta-elimination under reducing conditions and sugar-composition analysis revealed that the O-linked oligosaccharides were composed solely of mannose and bound to residue Ser5, Thr6, Thr7, Ser27, Ser28, Ser29 and Thr31 in the pre-S2 region.

[Oncogenes and growth factors in human epithelial tumors: their importance in diagnosis and prognosis]

The accumulation of the genetic alterations, the activation of oncogenes and the inactivation of tumor suppressor genes, play a critical role in the induction of the malignant tumours. In human solid tumors, oncogenes and growth factors are found at any of the different stages in carcinogenesis. The clinical results of these observations are the demonstration of some relations between activation and expression of the oncogenes and growth factors and clinical features or prognosis. Furthermore, they seem to permit definition of premalignant conditions or populations of high risk of disease.

Protective vaccination against bovine leukaemia virus infection by means of cell-derived vaccine

Tests were performed to determine whether live mammalian cells producing env gene glycoproteins and main structural protein p24 of bovine leukaemia virus (BLV), heterologous to bovine species, could serve as an immunogen in cattle to prevent induction of bovine leukaemia. Ovine virus-non-producing clonal cells NP-2 were used as the immunogen. The NP-2 cells synthesized only the env gene products--glycoprotein gp51 and gp30 and main structural protein p24 of BLV. The NP-2 cells, inoculated into rats, induced an antibody response directed against envelope glycoproteins of BLV. The antibodies neutralized the infectivity of BLV as determined by the VSV/BLV pseudotype neutralization test. Similar results were obtained by vaccination of cattle with these cells. A dose of less than or equal to 2 x 10(6) live cells inoculated subcutaneously induced an antibody response in cattle, while a high dose of killed cells was ineffective. The antibodies in cattle were directed against env products of BLV. A group of 92 cows was vaccinated and followed up for 4 years. The antibody levels fluctuated slightly during the 4-year observation period, generally decreasing with time, but revaccination always increased the antibody titre. No transfer of seropositivity was observed to seronegative animals which were kept in contact with vaccinated ones. In a separate experiment a group of young heifers, after repeated vaccination, were challenged with a high dose of infectious virus and/or virus-producing cells. The response to BLV infection was followed by syncytial induction assay after co-cultivation of white blood cells with indicator cells CC81.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of monoclonal antibodies in an ELISA for the diagnosis of bovine leukaemia virus infection

An ELISA diagnostic test for detection of bovine leukaemia virus (BLV) infected animals was developed. The test is based on the use of a mixture of monoclonal antibodies (MAbs) against envelope glycoprotein and against viral structural protein p24. The sensitivity and specificity of the test were found to be dependent on the relative proportions of MAbs of the appropriate epitope specificity. Polystyrene microtitre plates, wells or sticks were firstly coated with a mixture of purified MAbs and then non-purified viral antigens were adsorbed from tissue culture fluid obtained from BLV-producing cells. The optimal conditions for adsorption of MAbs and viral antigens as well as for the ELISA procedure were established. The test is more sensitive and cheaper (no need for virus antigen purification) than the routinely used ELISA using purified virus antigens. The assay is highly specific, rapid, practical and could be easily automated. It is suitable for the detection of BLV-antibodies in blood serum or milk in the large-scale screening programs for BLV-infected animals.

Induction of immune deficiency syndrome in rabbits by bovine leukaemia virus

Newborn rabbits were inoculated with bovine leukaemia virus (BLV). The majority of infected rabbits produced antiviral antibodies. All the seroconverted animals developed symptoms resembling AIDS and died several months after inoculation. The course of experimental infection of rabbits with BLV resembled in many respects the broad spectrum of clinical disorders associated with AIDS induced by HIV. Antibody response to virus proteins was followed by immune deficiency and signs of neuropathy, and the animals subsequently died of opportunistic infections. Virus transmission from infected babies to the mothers by contact was also observed. In some cases the virus was salvaged from lymphocytes of rabbits with the immune deficiency syndrome. The virus-specific sequences were found to be integrated at random in the DNA of haematopoietic cells and of some organs. Slight expression of viral RNAs in lymphocytes was found. Experimental infection of rabbits with BLV can be used in experiments to understand AIDS induction.

Bovine leukaemia virus packaging cell line for retrovirus-mediated gene transfer

Retroviral packaging cell lines were constructed by using the gag-pol gene of spleen necrosis virus, the gag-pol gene of Moloney murine leukaemia virus and the env gene of bovine leukaemia virus. The plasmids containing the gag-pol genes and the plasmid containing the env gene were cotransfected into NIH/3T3 and D17 cells. The cells containing the helper virus constructs were tested for their ability to package replication-defective murine leukaemia and avian reticuloendotheliosis retrovirus vectors. The titre of vector virus produced by each of the retroviral packaging cell lines was about 10(2) colony-forming units per ml of medium. Tests for events that might result in intact replication-competent retroviruses showed no evidence for the generation of such viruses. The vector viruses were able to infect dog and rat cells. Bovine cells were infected only after their cocultivation with the retroviral packaging cell lines producing murine leukaemia virus vectors, perhaps as a result of a low concentration of receptors.