A study of circulating anti-CD25 antibodies in non-small cell lung cancer

PURPOSE

Tumors can trigger specific immune response to tumor-associated antigens but the precise mechanism remains unclear. Since regulatory T-lymphocytes (Treg) play a crucial role in controlling autoimmune responses, the present work was undertaken to test whether dysfunction of Treg cells could be involved in developing autoimmunity in patients with lung cancer.

METHODS

In this study, we developed an in-house enzyme-linked immunosorbent assay to test circulating anti-CD25 autoantibodies among 272 patients with non-small cell lung cancer (NSCLC) and 226 control subjects matched in age, gender and smoking history.

RESULTS

Mann-Whitney U test showed that the anti-CD25 IgG level was significantly higher in patients with NSCLC than control subjects (Z = -7.48, P < 0.001) while the anti-CD25 IgA level was not significantly changed in the patient group as compared with the control group (Z = -1.34, P = 0.181). Spearman correlation analysis failed to reveal a significant correlation between the levels of anti-CD25 IgG and IgA either in patients with NSCLC (r = -0.034, P = 0.578) or in control subjects (r = 0.055, P = 0.429). ROC analysis showed an AUC of 0.70 for anti-CD25 IgG, in which NSCLC at stage III had the highest AUC (0.75). The sensitivity against a specificity of >90 % was 35.0 % for anti-CD25 IgG assay with an inter-assay deviation of 9.4 %, and 4.0 % for anti-CD25 IgA assay with an inter-assay deviation of 13.0 %.

CONCLUSIONS

Circulating anti-CD25 IgG antibody may be a useful biomarker for prognosis of lung cancer.

Human leukocyte antigen class I on peripheral blood mononuclear cells as a non-invasive biomarker for esophageal cancer

Esophageal cancer (EC) is a common malignant cancer threatening people's health. There are no universally accepted parameters for its early diagnosis. The aim of this study was to observe the expression of human leukocyte antigen class I (HLA-I) on peripheral blood mononuclear cells (PBMCs) of EC patients and in individuals of high-incidence area of EC so as to evaluate the feasibility of using this parameter as a potential non-invasive biomarker for the early diagnosis of EC. The present study enrolled 58 pathological confirmed EC patients, 46 patients with benign esophageal disease, and 65 healthy volunteers. Expression levels of HLA-I protein and mRNA on PBMCs were determined by flow cytometry and quantitative reverse transcriptase polymerase chain reaction, respectively. Then, 181 volunteers from Lijiadian, a village with high morbidity of EC, and 153 age- and gender-matched health volunteers were involved in this study to observe HLA-I expressions in individuals of high-incidence area of EC. Compared with benign esophageal disease and health volunteers, the expressions of HLA-I protein and mRNA on PBMCs of EC patients are significantly decreased, especially in patients with stage III and IV EC, but was not influenced by patient's age and gender. Furthermore, individuals of high-incidence area of EC also show downregulated HLA-I protein, but not mRNA, expression on PBMCs. Altogether, HLA-I expression on PBMCs of EC patients and individuals from high-incidence area of EC is downregulated, and this parameter might be used as a potential predictor of EC.

Deacetylation of FOXO3 by SIRT1 or SIRT2 leads to Skp2-mediated FOXO3 ubiquitination and degradation

Sirtuin deacetylases and FOXO (Forkhead box, class O) transcription factors have important roles in many biological pathways, including cancer development. SIRT1 and SIRT2 deacetylate FOXO factors to regulate FOXO function. Because acetylation and ubiquitination both modify the ɛ-amino group of lysine residues, we investigated whether FOXO3 deacetylation by SIRT1 or SIRT2 facilitates FOXO3 ubiquitination and subsequent proteasomal degradation. We found that SIRT1 and SIRT2 promote FOXO3 poly-ubiquitination and degradation. Proteasome-inhibitor treatment prevented sirtuin-induced FOXO3 degradation, indicating that this process is proteasome dependent. In addition, we demonstrated that E3 ubiquitin ligase subunit Skp2 binds preferentially to deacetylated FOXO3. Overexpression of Skp2 caused poly-ubiquitination of FOXO3 and degradation, whereas knockdown of Skp2 increased the amount of FOXO3 protein. We also present evidence that SCF-Skp2 ubiquitinates FOXO3 directly in vitro. Furthermore, mutating four known acetylated lysine residues (K242, K259, K290 and K569) of FOXO3 into arginines to mimic deacetylated FOXO3 resulted in enhanced Skp2 binding but with inhibition of FOXO3 ubiquitination; this suggests that some or all of these four lysine residues are likely the sites for ubiquitination. In the livers of mice deficient in SIRT1, we detected increased expression of FOXO3, indicating SIRT1 regulates FOXO3 protein levels in vivo. Furthermore, we found that the elevation of SIRT1 and Skp2 expression in malignant PC3 and DU145 prostate cells is responsible for the downregulation of FOXO3 protein levels in these cells. Taken together, our data support the notion that deacetylation of FOXO3 by SIRT1 or SIRT2 facilitates Skp2-mediated FOXO3 poly-ubiquitination and proteasomal degradation.

CD34 positive cells seeded on small caliber man-made vascular grafts exhibit increased antithrombogenic property compared with unfractioned mononuclear cells

AIM

The aim of this study was to compare the therapeutic potential of purified CD34+ cells with that of unfractioned mononuclear cells (MNCs) for the antithrombogenic property after seeding on the small caliber man-made grafts.

METHODS

Unfractioned MNCs and CD34+ cells were isolated from canine bone marrow. Differentiation of CD34 cells and unfractioned MNCs into endothelial cells were examined by CD31and vWF immunohistochemistry or immunofluorescence stain, endothelial cell function were evaluated via low-density lipoprotein (ac-LDL) - DiL incorpration and in vitro angiogenesis assay. Platelet adhesion assay was performed to determine antiplatelet adhesion property of the cells in vitro. Equal number of both cells were seeded onto the luminal surface of small caliber man-made grafts and implanted to replace a segment of common carotid artery. At different time points (24 h, 72 h, and 1 week) the grafts were retrieved. HE staining and SEM exam were performed.

RESULTS

CD34+ cells acquired significantly more CD31 and VWF expression, increased angiogenic potential and low-density lipoprotein (ac-LDL) incorporation compared to unfractioned MNCs under the induction of VEGF. More platelets were found to adhere to the surface of unfractioned MNCs group than to the CD34+ cell group. In vivo study demonstrated that more platelet adhesion and thrombus formation were observed in the unfractioned MNCs group rather than the CD34+ group. All the grafts in both groups were patent after implantation, except one graft seeded with unfractioned MNCs, occluded at 1 week. Statistically lower ratio of thrombi was found in the CD34+ cell seeding group at 24 h and 1 week after implantation, compared with the unfractioned MNCs one (P<0.05).

CONCLUSION

CD34+ cell exerted better antithrombogenic property than unfractioned MNCs after seeding onto the small caliber vessel grafts.

Identification of two auto-cleavage products of nonstructural protein 1 (nsp1) in porcine reproductive and respiratory syndrome virus infected cells: nsp1 function as interferon antagonist

The porcine reproductive and respiratory syndrome virus nsp1 is predicted to be auto-cleaved from the replicase polyprotein into nsp1alpha and nsp1beta subunits. In infected cells, we detected the actual existence of nsp1alpha and nsp1beta. Cleavage sites between nsp1alpha/nsp1beta and nsp1beta/nsp2 were identified by protein microsequencing analysis. Time course study showed that nsp1alpha and nsp1beta mainly localize into the cell nucleus after 10 h post infection. Further analysis revealed that both proteins dramatically inhibited IFN-beta expression. The nsp1beta was observed to significantly inhibit expression from an interferon-stimulated response element promoter after Sendai virus infection or interferon treatment. It was further determined to inhibit nuclear translocation of STAT1 in the JAK-STAT signaling pathway. These results demonstrated that nsp1beta has ability to inhibit both interferon synthesis and signaling, while nsp1alpha alone strongly inhibits interferon synthesis. These findings provide important insights into mechanisms of nsp1 in PRRSV pathogenesis and its impact in vaccine development.

Cocaine withdrawal enhances long-term potentiation in rat hippocampus via changing the activity of corticotropin-releasing factor receptor subtype 2

The neural plasticity mechanisms that underlie learning and memory may also be engaged when drug addiction occurs. It was reported that long-lasting neuroadaptations induced by cocaine use and withdrawal require the participation of hippocampus. However, the role of corticotrophin-releasing factor receptors in this process remains unclear. In the present study, the effects of chronic cocaine treatment (a 14-day cocaine administration, 20 mg/kg i.p., daily) and short-term cocaine withdrawal (a 3-day cocaine extinction following a 14-day cocaine administration) on long-term potentiation (LTP), one prominent cellular mechanism for learning and memory, were assessed in the CA1 region of the rat hippocampal slices. We found that cocaine withdrawal, but not the chronic cocaine administration itself, significantly enhanced the magnitude of LTP in hippocampal slices, as compared with that in saline controls. Selective blockade of corticotrophin-releasing factor receptor subtype 1 (CRF(1)) with the specific antagonist NBI 27914 (100 nM in vitro) attenuated the magnitude of LTP in hippocampal slices from cocaine withdrawal rats, and intriguingly, also from saline control rats, while specific blockade of corticotrophin-releasing factor receptor subtype 2 (CRF(2)) with astressin2-B (100 nM in vitro) selectively attenuated the magnitude of LTP in hippocampal slices from cocaine withdrawal rats. Our data suggest that short-term cocaine withdrawal treatment may cause synaptic plasticity in hippocampus partially via changing the activity of CRF(2) in the hippocampus.

Mitochondrial DNA-based analysis of genetic variation and relatedness among Sri Lankan indigenous chickens and the Ceylon junglefowl (Gallus lafayetti)

Indigenous chickens (IC) in developing countries provide a useful resource to detect novel genes in mitochondrial and nuclear genomes. Here, we investigated the level of genetic diversity in IC from five distinct regions of Sri Lanka using a PCR-based resequencing method. In addition, we investigated the relatedness of IC to different species of junglefowls including Ceylon (CJF; Gallus lafayetti), a subspecies that is endemic to Sri Lanka, green (Gallus varius), grey (Gallus sonneratii) and red (Gallus gallus) junglefowls. A total of 140 birds including eight CJF were used to screen the control region of the mitochondrial DNA sequence for single nucleotide polymorphisms (SNPs) and other variants. We detected and validated 44 SNPs, which formed 42 haplotypes and six haplogroups in IC. The SNPs observed in the CJF were distinct and the D-loop appeared to be missing a 62-bp segment found in IC and the red junglefowl. Among the six haplogroups of IC, only one was region-specific. Estimates of haplotype and nucleotide diversities ranged from 0.901 to 0.965 and from 0.011 to 0.013 respectively, and genetic divergence was generally low. Further, variation among individuals within regions accounted for 92% of the total molecular variation among birds. The Sri Lankan IC were more closely related to red and grey junglefowls than to CJF, indicating multiple origins. The molecular information on genetic diversity revealed in our study may be useful in developing genetic improvement and conservation strategies to better utilize indigenous Sri Lankan chicken resources.

A novel member of the Rhomboid family, RHBDD1, regulates BIK-mediated apoptosis

Rhomboid family members are widely conserved and found in all three kingdoms of life. They are serine proteases and serve important regulatory functions. In the present study, a novel gene highly expressed in the testis, RHBDD1, is shown to be a new member of the Rhomboid family, participating in the cleavage of BIK, a proapoptotic member of the Bcl-2 family. The RHBDD1-involved proteolytic modification is upstream of the BIK protein degradation pathway. Mutagenesis studies show that the amino acid residues glycine142 and serine144 of RHBDD1 are crucial for its activity in cleaving BIK at a site located in the transmembrane region. Overexpression or knock-down of RHBDD1 in HEK 293T cells can reduce or enhance BIK-mediated apoptosis, respectively. The present findings suggest that, by acting as a serine protease, RHBDD1 modulates BIK-mediated apoptotic activity.

Urocortin ameliorates diabetic nephropathy in obese db/db mice

BACKGROUND AND PURPOSE

Hyperglycaemia induces overproduction of mitochondrial reactive oxygen species (ROS) in endothelial cells, which is believed to be a major molecular mechanism underlying complications of diabetes, including diabetic nephropathy. Impairment of endothelium-dependent vasodilatation is found in type 2 diabetes. Urocortin is a 40 amino-acid peptide related to the corticotrophin-releasing factor (CRF) family, which suppresses production of ROS in endothelial cells and sustains endothelium-dependent relaxations of rat coronary artery. However, it is not clear if urocortin has any effect on diabetic nephropathy.

EXPERIMENTAL APPROACH

Possible mechanisms underlying the effects of urocortin on diabetic nephropathy were investigated in db/db mice and cultured rat mesangial cells.

KEY RESULTS

Urocortin decreased body weight, plasma levels of advanced glycation end-products, blood urea nitrogen and creatinine levels. However, food intake, plasma insulin and glucose levels remained unaffected. Superoxide dismutase activity was increased markedly, whereas malonaldehyde levels in kidney homogenate and sorbitol concentrations in red blood cells were decreased significantly in urocortin-treated mice. Urocortin significantly decreased glomerular extracellular matrix expansion and accumulation in kidney. Moreover, urocortin inhibited the overexpression of transforming growth factor-beta 1 and connective tissue growth factor in rat mesangial cells induced by 25 mM glucose. All the effects of urocortin, except sorbitol accumulation, were abolished by the non-selective CRF receptor blocker, astressin.

CONCLUSION AND IMPLICATIONS

Urocortin could significantly ameliorate diabetic nephropathy and this effect was mediated via the CRF receptor.

Role of erythropoietin in cancer-related anaemia: a double-edged sword?

Anaemia often occurs in cancer patients and its origin is multifactorial, resulting from either bone marrow infiltration of cancer cells or cytotoxic effects produced by chemotherapy and radiotherapy. Anaemia impacts significantly on quality of life and appears markedly to limit disease control. Erythropoietin stimulates erythrocyte formation and the human recombinant form is useful in treating anaemia in cancer patients. Over the past decade erythropoietin has been associated with amelioration of anaemia and reduced need for blood transfusions. Nevertheless, several pre-clinical and clinical trials, employing relatively high doses of erythropoietin, have been halted recently following increased mortality and morbidity, primarily due to thrombotic events and possible tumour growth stimulation. It is, therefore, too early to know whether erythropoietin is useful in controlling morbidity and mortality in cancer-related anaemia. The risk-benefit of erythropoietic agents should be studied in carefully controlled trials. This review discusses prevalent issues and addresses key questions concerning the use of erythropoietic agents for the treatment of cancer-related anaemia.

Automated synthesis and composition of taskblocks for control of manufacturing systems

Automated control synthesis methods for discrete-event systems promise to reduce the time required to develop, debug, and modify control software. Such methods must be able to translate high-level control goals into detailed sequences of actuation and sensing signals. In this paper, we present such a technique. It relies on analysis of a system model, defined as a set of interacting components, each represented as a form of condition system Petri net. Control logic modules, called taskblocks, are synthesized from these individual models. These then interact hierarchically and sequentially to drive the system through specified control goals. The resulting controller is automatically converted to executable control code. The paper concludes with a discussion of a set of software tools developed to demonstrate the techniques on a small manufacturing system.

A novel Bacillus thuringiensis strain LLB6, isolated from bryophytes, and its new cry2Ac-type gene

AIMS

To isolate and characterize the novel Bacillus thuringiensis strains from bryophytes collected from Wuyi Mountain, Fujian Province of China, and identify new B. thuringiensis strains and toxins active against mosquitoes.

METHODS AND RESULTS

Twelve novel B. thuringiensis strains were isolated from 76 bryophyte samples. According to the results of this preliminary screening, LLB6 was the most toxic to Aedes albopictus. Then phase-contrast as well as scanning electron microscopy, bioassays, cloning, sequencing and expression were performed to characterize the novel isolate LLB6 and its new gene cry2Ac5.

CONCLUSIONS

Bacillus thuringiensis occurred naturally on bryophytes. LLB6 isolated from Physcomitrium japonicum was toxic to A. albopictus. A new cry2Ac5 gene of LLB6 was detected, cloned and expressed successfully. Bioassays on A. albopictus showed that the expressed Cry2Ac5 was also toxic to the third instar larvae.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of B. thuringiensis strains isolated from bryophytes. It represents a specific source of new B. thuringiensis strains and is of great importance for the knowledge of the ecology of B. thuringiensis. Novel LLB6 harboring the new gene cry2Ac5 and its expressed Cry2Ac5 protein revealed activity against A. albopictus and became a new member of B. thuringiensis toxins.

Comparison of Plasma Uric Acid Levels in Five Varieties of the Domestic Turkey, Meleagris gallopavo

Plasma uric acid (PUA) is a consensus physiological biomarker for many phenotypes in vertebrates because it is a reliable indicator for processes such as oxidative stress and tubular function. In birds, it is considered a major antioxidant and is also the primary endproduct of nitrogen metabolism. Despite this importance, knowledge of baseline levels of PUA in physiologically normal birds, including the turkey, Meleagris gallopavo, is limited. Here, we compared PUA levels in a total of 106 apparently normal male and female birds at 8 and 32 wk of age from 5 strains of the domestic turkey, including Bourbon Red, Narragansett, Blue Slate, Royal Palm, and Spanish Black. Though differences in PUA were not significant at 8 and 32 wk of age, BW, variety, and sex effects were highly significant. When adjusted for BW, female birds had, on average, a higher PUA per kilogram of BW than male birds. When adjusted for both sex and BW, Royal Palm birds had the lowest average PUA, and Blue Slate had the highest PUA. Results of these investigations represent the first comparative analysis of PUA in physiologically normal turkey varieties. They suggest that differences in basal plasma levels of uric acid in physiologically normal turkeys are influenced by sex, weight, and genetic background but may be independent of age.

Dietary protein concentration affects plasma arteriovenous difference of amino acids across the porcine mammary gland1

The objective of this study was to determine whether the porcine mammary gland responds to increasing dietary CP concentration through changes in AA arteriovenous difference (a-v). Sixteen Landrace x Yorkshire lactating sows were provided ad libitum access to one of four isocaloric diets varying in CP concentration (7.8, 13.0, 18.2, and 23.5 %; as-fed basis). Litters were adjusted to 11 pigs within 48 h of birth. Sows were fitted with catheters in the carotid artery and main mammary vein on d 4. On d 10, 14, 18, and 22 of lactation, arterial and venous blood samples were obtained every 30 min over 6 h. Milk yield was estimated on d 11 and 21 using the D2O dilution technique. Final litter sizes on d 21 were 10.3, 11, 9.5, and 11 piglets for sows fed the 7.8, 13.0, 18.2, and 23.5% CP diets, respectively. Piglet ADG tended (P = 0.088) to increase with increasing dietary CP concentration and were 186, 221, 220, and 202 g for sows fed the 7.8, 13.0, 18.2, and 23.5% CP diet, respectively. Daily total milk yield on d 21 (kg milk/d) tended (P = 0.099) to increase, and average milk yield per nursed piglet (kg of milk-pig(-1)d(-1)) increased (P < 0.05) with increasing CP concentration and were, on a per-piglet basis, 0.95, 1.19, 1.14 and 1.13 kg of milk/d for the 7.8, 13.0, 18.2, and 23.5% CP diets, respectively. As dietary CP increased from 7.8 to 23.5%, isoleucine and leucine a-v increased linearly only (linear, P < 0.01); all other AA a-v increased, reached a maximum in sows fed 18.2% CP, and decreased thereafter in sows fed 23.5% CP (quadratic, from P = 0.10 to P < 0.05). Amino acid uptake by the entire udder and by each gland increased (linear, P < 0.05) with increasing dietary CP. Arteriovenous differences response to increasing day of lactation varied among AA, from no change for histidine, isoleucine, lysine, methionine, tryptophan, and valine, to a linear trend increase for arginine (P = 0.055), leucine (P = 0.064), phenylalanine (P = 0.101), and threonine (P = 0.057). In summary, for the majority of AA, a-v increased with increasing dietary CP concentration from 7.8 to 18.2%, but decreased when CP concentration exceeded 18.2%. In contrast, mammary AA uptake, piglet ADG and milk yield per pig increased linearly with increasing dietary CP, suggesting a coordinated regulation between AA delivery and transport to meet the demand for milk yield.

Mobility of sulfate in forest soils: kinetic modeling

Understanding sulfate transport and retention dynamics in forest soils is a prerequisite in predicting SO4 concentration in the soil solution and in lake and stream waters. In this study forest soil samples from the Gårdsjön catchments, Sweden, were used to study SO4 transport in soil columns from the upper three soil horizons (E, Bs, and BC). The columns were leached using a sequential leaching technique. The input solutions were CaSO4 equilibrated with forest floor material. Leaching behavior of SO4 and concentration in the effluent were measured from columns from individual horizons. Sulfate was always retained in the Bs and BC horizons, while the pattern for the E horizon varied. Attempts were also made to model SO4 breakthrough results based on miscible displacement approaches and solute convection-dispersion equation (CDE) in porous media. Several retention mechanisms were incorporated into the CDE to account for possible reversible and irreversible SO4 reactions in individual soil layers. Our modeling efforts were inadequate in describing the mobility of SO4 in the top (E) horizon. Moreover, a linear equilibrium approach was generally inadequate for describing SO4 sorption during transport in the Bs and BC horizons. In contrast, we found that the model provided good descriptions of all breakthrough results when SO4 reactivity was accounted for based on nonlinear equilibrium or first-order kinetic processes. Moreover, based on model parameter estimates, the reactivity or retention of SO4 during transport is concentration dependent. We conclude that sulfate retention during transport in this forest soil is most likely controlled by kinetic reactivity of SO4 of the reversible and irreversible mechanisms.

Comparative analyses of multi-species sequences from targeted genomic regions

The systematic comparison of genomic sequences from different organisms represents a central focus of contemporary genome analysis. Comparative analyses of vertebrate sequences can identify coding and conserved non-coding regions, including regulatory elements, and provide insight into the forces that have rendered modern-day genomes. As a complement to whole-genome sequencing efforts, we are sequencing and comparing targeted genomic regions in multiple, evolutionarily diverse vertebrates. Here we report the generation and analysis of over 12 megabases (Mb) of sequence from 12 species, all derived from the genomic region orthologous to a segment of about 1.8 Mb on human chromosome 7 containing ten genes, including the gene mutated in cystic fibrosis. These sequences show conservation reflecting both functional constraints and the neutral mutational events that shaped this genomic region. In particular, we identify substantial numbers of conserved non-coding segments beyond those previously identified experimentally, most of which are not detectable by pair-wise sequence comparisons alone. Analysis of transposable element insertions highlights the variation in genome dynamics among these species and confirms the placement of rodents as a sister group to the primates.

Glucagon-like peptide 2 function in domestic animals

Glucagon-like peptide 2 (GLP-2) is a member of family of peptides derived from the proglucagon gene expressed in the intestines, pancreas and brain. Tissue-specific posttranslational processing of proglucagon leads to GLP-2 and GLP-1 secretion from the intestine and glucagon secretion from the pancreas. GLP-2 and GLP-1 are co-secreted from the enteroendocrine L-cells located in distal intestine in response to enteral nutrient ingestion, especially carbohydrate and fat. GLP-2 secretion is mediated by direct nutrient stimulation of the L-cells and indirect action from enteroendocrine and neural inputs, including GIP, gastrin-releasing peptide (GRP) and the vagus nerve. GLP-2 is secreted as a 33-amino acid peptide and is rapidly cleaved by dipeptidylpeptidase IV (DPP-IV) to a truncated peptide which acts as a weak agonist with competitive antagonistic properties. GLP-2 acts to enhance nutrient absorption by inhibiting gastric motility and secretion and stimulating nutrient transport. GLP-2 also suppresses food intake when infused centrally. The trophic actions of GLP-2 are specific for the intestine and occur via stimulation of crypt cell proliferation and suppression of apoptosis in mucosal epithelial cells. GLP-2 reduces gut permeability, bacterial translocation and proinflammatory cytokine expression under conditions of intestinal inflammation and injury. The effects of GLP-2 are mediated by a G-protein-linked receptor that is localized to the intestinal mucosa and hypothalamus. The intestinal localization of the GLP-2R to neural and endocrine cells, but not enterocytes, suggests that its actions are mediated indirectly via a secondary signaling mechanism. The implications of GLP-2 in domestic animal production are largely unexplored. However, GLP-2 may have therapeutic application in treatment of gastrointestinal injury and diarrheal diseases that occur in developing neonatal and weanling animals.

Whole-cell biosensing of 3-chlorocatechol in liquids and soils

A rapid and sensitive technique is needed to analyze water and soils for chlorocatechols, common environmental pollutants produced from wood pulp chlorination and other processes. The soil bacteria Pseudomonas putida, harboring plasmid pSMM50R-B', selectively express beta-galactosidase in response to 3-chlorocatechol in pure water samples. The objective of the study was to determine whether background matrices in fresh water, sea water, soils, and organic solvents interfered with 3-chlorocatechol analysis by use of a bacteria-sensing system and by high-performance liquid chromatography (HPLC). Although 3-chlorocatechol detection by HPLC was not substantially affected by the background composition of aqueous or organic solvents, HPLC was ineffective in the analysis of contaminated soils due to irreversible contaminant sorption. Whereas detection by the bacteria-sensing system was reduced in the presence of aqueous and organic solvents, interferences could be reduced by sample dilution. 3-Chlorocatechol was detected when the bacteria were added directly to contaminated soils, suggesting that the organism enhanced desorption or had access to the sorbed compounds. Results indicate that the bacteria-sensing system has wide application for detection of 3-chlorocatechols in environmental samples, especially in soils where extraction and HPLC analysis are not efficient due to extensive contaminant sorption.

Effects of tumors on inhaled pharmacologic drugs: II. Particle motion

Computer simulations were conducted to describe drug particle motion in human lung bifurcations with tumors. The computations used FIDAP with a Cray T90 supercomputer. The objective was to better understand particle behavior as affected by particle characteristics, airflow conditions, and disease-modified airway geometries. The results indicated that increases in particle sizes, breathing intensities and tumor sizes could enhance drug deposition on the tumors. The modeling suggested that targeted drug delivery could be achieved by regulating breathing parameters and designing (selecting physical features of) aerosolized drugs. We present the theoretical work as a step towards improving aerosol therapy protocols. Since modeling describes factors affecting dose, it is complementary to considerations of the molecular aspects of drug formulation and pharmacokinetics.

Effects of tumors on inhaled pharmacologic drugs: I. Flow patterns

Lung carcinomas are now the most common form of cancer. Clinical data suggest that tumors are found preferentially in upper airways, perhaps specifically at carina within bifurcations. The disease can be treated by aerosolized pharmacologic drugs. To enhance their efficacies site-specific drugs must be deposited selectively. Since inhaled particles are transported by air, flow patterns will naturally affect their trajectories. Therefore, in Part I of a systematic investigation, we focused on tumor-induced effects on airstreams, in Part II (the following article [p. 245]), particle trajectories were determined. To facilitate the targeted delivery of inhaled drugs, we simulated bifurcations with tumors on carinas using a commercial computational fluid dynamics (CFD) software package (FIDAP) with a Cray T90 supercomputer and studied effects of tumor sizes and ventilatory parameters on localized flow patterns. Critical tumor sizes existed; e.g., tumors had dominant effects when r/R > or = 0.8 for bifurcation 3-4 and r/R > or = 0.6 for bifurcation 7-8 (r = tumor radius and R = airway radius). The findings suggest that computer modeling is a means to integrate alterations to airway structures caused by diseases into aerosol therapy protocols.

A catalytic antibody produces fluorescent tracers of gap junction communication in living cells

The antibody 38C2 efficiently catalyzed a retro-Michael reaction to convert a novel, cell-permeable fluorogenic substrate into fluorescein within living cells. In vitro, the antibody converted the substrate to fluorescein with a k(cat) of 1.7 x 10(-5) s(-1) and a catalytic proficiency (k(cat)/k(uncat)K(m)) of 1.4 x 10(10) m(-1) (K(m) = 7 microm). For hybridoma cells expressing antibody or Chinese Hamster Ovarian (CHO) cells injected with antibody, incubation of the substrate in the extracellular medium resulted in bright intracellular fluorescence distinguishable from autofluorescence or noncatalyzed conversion of substrate. CHO cells loaded with antibody were 12 times brighter than control cells, and more than 85% of injected cells became fluorescent. The fluorescein produced by the antibody traveled into neighboring cells through gap junctions, as demonstrated by blocking dye transfer using the gap junction inhibitor oleamide. The presence of functional gap junctions in CHO cells was confirmed through oleamide inhibition of lucifer yellow transfer. These studies demonstrate the utility of the intracellular antibody reaction, which could generate tracer dyes in specific cells within complex multicellular environments simply by bathing the system in substrate.

Estradiol (E2) elicits SRC phosphorylation in the mouse neocortex: the initial event in E2 activation of the MAPK cascade?

In neocortical explants, E2 activates various signaling components of the MAPK cascade, including B-Raf and MAPK kinase-dependent ERK, suggesting a possible role in the differentiative actions of E2 in the brain. To further characterize the signaling pathways activated by E2, we determined whether c-Src, a member of the Src family of nonreceptor tyrosine kinases and an important modulator of both the MAPK cascade and neuronal differentiation, may play a role in E2 signaling. The present studies show for the first time in the brain that E2 elicits phosphorylation of c-Src on three functionally critical tyrosine residues (Y220, Y423, and Y534), and that this phosphorylation occurs despite disruption of ER alpha (in ER knockout mice). PP2, a Src family kinase inhibitor, suppressed not only E2-induced phosphorylation of c-Src, but ERK phosphorylation as well, suggesting that c-Src may be an upstream regulator of E2 signaling. E2-induced phosphorylation of c-Src is associated with increased tyrosine phosphorylation of Shc, increased association of Shc with Grb2, and induction of Ras, but not Rap1, activation. Together, these data provide evidence that E2 activates a novel c-Src-dependent signal transduction pathway in the developing brain.

Effect of batroxobin on expression of neural cell adhesion molecule in temporal infarction rats and spatial learning and memory disorder

The effect of Batroxobin expression of neural cell adhesion molecule (NCAM) in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemical methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats and at the same time NCAM expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of NCAM immune reactive cells of Batroxobin-treated rats was more than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats and the regulation of the expression of NCAM is probably related to the neuroprotective mechanism.

[Optimization of synthetic culture condition on lignin biodegradation ability of alkaliphilic ligninolytic bacteria using orthogonal experimental design]

The effects of seven single culture factors on lignin biodegradation ability of alkaliphilic ligninolytic bacteria strain 6 in alkaline liquid medium (pH approximately 10.5) with compounded carbons were optimized using orthogonal experiments. The result showed the seven single culture factors promote the activities of Laccase and MnP and the degradation rate of wheat straw lignin in varying degrees. The synthetic result was analysised. The optimal synthetic condition was static culture (10 days culture period), 37 degrees C, the initial pH10.6, 1 g/L sugar (the starting carbons), wheat straw lignin (the second carbons, wheat straw powder 20 g/L, added into on the fourth day after inoculation), 1.2 g/L NH4NO3 (nitrogen), 0.3% detergent T-80, 70 ml medium/250 ml flask.