Insertion of an immunodominant T helper cell epitope within the Group A Streptococcus M protein promotes an IFN-γ-dependent shift from a non-protective to a protective immune response

The common pathogen Group A Streptococcus (GAS, Streptococcus pyogenes) is an extracellular bacterium that is associated with a multitude of infectious syndromes spanning a wide range of severity. The surface-exposed M protein is a major GAS virulence factor that is also target for protective antibody responses. In this study, we use a murine immunization model to investigate aspects of the cellular and molecular foundation for protective adaptive immune responses generated against GAS. We show that a wild type M1 GAS strain induces a non-protective antibody response, while an isogenic strain carrying the immunodominant 2W T helper cell epitope within the M protein elicits an immune response that is protective against the parental non-recombinant M1 GAS strain. Although the two strains induce total anti-GAS IgG levels of similar magnitude, only the 2W-carrying strain promotes elevated titers of the complement-fixing IgG2c subclass. Protection is dependent on IFN-γ, and IFN-γ-deficient mice show a specific reduction in IgG2c levels. Our findings suggest that inclusion of the 2W T cell epitope in the M protein confers essential qualitative alterations in the adaptive immune response against GAS, and that sparsity in IFN-γ-promoting Th cell epitopes in the M protein may constitute an immune evasion mechanism, evolved to allow the pathogen to avoid attack by complement-fixing antibodies.

Multi-objective home health care routing: a variable neighborhood search method

Health and convenience are two indispensable indicators of the society promotion. Nowadays, to improve community health levels, the comfort of patients and those in need of health services has received much attention. Providing Home Health Care (HHC) services is one of the critical issues of health care to improve the patient convenience. However, manual nurse planning which is still performed in many HHC institutes results in a waste of time, cost, and ultimately lower efficiency. In this research, a multi-objective mixed-integer model is presented for home health care planning so that in addition to focusing on the financial goals of the institution, other objectives that can help increase productivity and quality of services are highlighted. Therefore, four different objectives of the total cost, environmental emission, workload balance, and service quality are addressed. Taking into account medical staff with different service levels, and the preferences of patients in selecting a service level, as well as different vehicle types, are other aspects discussed in this model. The epsilon-constraint method is implemented in CPLEX to solve small-size instances. Moreover, a Multi-Objective Variable Neighborhood Search (MOVNS) composed of nine local neighborhood moves is developed to solve the practical-size instances. The results of the MOVNS are compared with the epsilon-constraint method, and the strengths and weaknesses of the proposed algorithm are demonstrated by a comprehensive sensitivity analysis. To show the applicability of the algorithm, a real example is designed based on a case study, and the results of the algorithm over real data are evaluated.

Effects of carotenoid pigmentation in salmon on antibiotic extraction recovery, matrix effects and accuracy of quantification by ultrahigh performance liquid chromatography coupled to tandem mass spectrometry

Carotenoid pigmentation in salmon may interfere with the accuracy of antibiotic analysis with ultra-high pressure liquid chromatography coupled to tandem spectrometry (UPLC-MS/MS) by causing matrix effects or affecting the recovery of compounds during extraction. In the present study, we used both pigmented and non-pigmented salmon to understand the role pigments play on antibiotic analysis, and tested whether clean-up of the extract with dispersive solid phase extraction (dSPE) or hydrophilic-lipophilic balance (HLB) SPE clean-up reduces matrix effects. Thirty antibiotics and their respective class-specific surrogate standards were measured in Sockeye (pigmented), King (pigmented) and Ivory King (non-pigmented) salmon extracted using the QUEChERS method, or a modified QUEChERS method involving dSPE or HLB SPE clean-up (for Sockeye salmon only). Significant matrix effects and lower percent recoveries of spiked antibiotics were observed in pigmented versus non-pigmented salmon extracted with the QUEChERS method. Dispersive SPE clean-up did not improve extraction recoveries or matrix effects. However, SPE clean-up with HLB columns improved matrix effects for several antibiotics but reduced the percent recovery to < 30%. Across all types of salmon analyzed, the accuracy of quantitation was minimally impacted, likely due to similar behavior of the surrogate standards tagged to each antibiotic class during extraction. Our results demonstrate that carotenoids in salmon are associated with significant matrix effects and low extraction recoveries, but do not impact accuracy.

Chronic exposure to traffic-related air pollution reduces lipid mediators of linoleic acid and soluble epoxide hydrolase in serum of female rats

Chronic exposure to traffic-related air pollution (TRAP) is known to promote systemic inflammation, which is thought to underlie respiratory, cardiovascular, metabolic and neurological disorders. It is not known whether chronic TRAP exposure dampens inflammation resolution, the homeostatic process for stopping inflammation and repairing damaged cells. In vivo, inflammation resolution is facilitated by bioactive lipid mediators known as oxylipins, which are derived from the oxidation of polyunsaturated fatty acids. To understand the effects of chronic TRAP exposure on lipid-mediated inflammation resolution pathways, we measured total (i.e. free+bound) pro-inflammatory and pro-resolving lipid mediators in serum of female rats exposed to TRAP or filtered air (FA) for 14 months. Compared to rats exposed to FA, TRAP-exposed rats showed a significant 36-48% reduction in fatty acid alcohols, specifically, 9-hydroxyoctadecadienoic acid (9-HODE), 11,12-dihydroxyeicosatetraenoic acid (11,12-DiHETE) and 16,17-dihydroxydocosapentaenoic acid (16, 17-DiHDPA). The decrease in fatty acid diols (11,12-DiHETE and 16, 17-DiHDPA) corresponded to a significant 34-39% reduction in the diol to epoxide ratio, a marker of soluble epoxide hydrolase activity; this enzyme is typically upregulated during inflammation. The findings demonstrate that 14 months exposure to TRAP reduced pro-inflammatory 9-HODE concentration and dampened soluble epoxide hydrolase activation, suggesting adaptive immune changes in lipid mediator pathways involved in inflammation resolution.

Antibiotic standards stored as a mixture in water: methanol are unstable at various temperatures irrespective of pH and glass container silanization

It is well-established that antibiotics stored individually at their optimal pH and in appropriate solvents are stable over time. However, limited information exists on the stability of antibiotics from multiple classes when prepared and stored as a mixture prior to multiresidue analysis by mass spectrometry. This study tested the stability of antibiotic standard mixtures from eight classes [amphenicols, tetracyclines, sulfonamides, quinolones, macrolides, β-lactams, lincosamides and miscellaneous (i.e., trimethoprim)] in relation to the water:methanol ratio, presence of sodium hydroxide base (to solubilise quinolones), storage temperature, and container type including plain and silanized glass vials. Antibiotics were analysed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. Several antibiotics, mainly quinolones, tetracyclines and macrolides, were unstable when stored as mixtures for one week regardless of the water:methanol ratio, storage temperature (4, -20 or -80 °C) and presence/absence of sodium hydroxide. Silanization of glassware improved the storage stability of quinolones and macrolides but reduced the stability of tetracyclines and other antibiotics including florfenicol amine, penicillin G, erythromycin and sulfadiazine. Our results show that several antibiotics in water:methanol are unstable when stored as a mixture and suggest a limited advantage of using base or silanized glass vials for the preparation and storage of antibiotic standards mixed together. Freshly prepared antibiotic standard mixtures are recommended for multi-residue quantitation of antibiotics.Abbreviations AMOX: amoxicillin; AMP: ampicillin; AZ: azithromycin; CAP: chloramphenicol; CE: collision energy; CTC: chlortetracycline; CIP: ciprofloxacin; DOX: doxycycline; ENO: enoxacin; ENRO: enrofloxacin; ERYTH: erythromycin; FF: florfenicol; FFA: florfenicol amine; FLU: flumequine; HDPE: high-density polyethylene; LC-MS/MS: liquid chromatography-tandem mass spectrometry; LIN: lincomycin; MRM: multiple reaction monitoring; NOR: norfloxacin; OFL-D3: ofloxacin-D3; OXO: oxolinic acid; OTC: oxytetracycline; PEN-G: penicillin G; PEN-V: penicillin V; ROX: roxithromycin; SDM: sulfadimethoxine; SDZ: sulfadiazine; SMX: sulfamethoxazole; SMZ-D4: sulfamethazine-D4; SSZ: sulfasalazine; TC: tetracycline; TAP: thiamphenicol; TILM: tilmicosin; TRIM: trimethoprim; TL: tolerance limit; VIRG: virginiamycin; UPLC-MS/MS: ultra-high pressure liquid chromatography-tandem mass spectrometry.

Quantification of Nonpersistent Pesticides in Small Volumes of Human Breast Milk with Ultrahigh Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

Existing methods for the analysis of pesticides in human breast milk involve multiple extraction steps requiring large sample and solvent volumes, which can be a major obstacle in large epidemiologic studies. Here, we developed a simple, low-volume method for extracting organophosphates, pyrethroids, carbamates, atrazine, and imidacloprid from 100 to 200 μL of human breast milk. Multiple extraction protocols were tested including microwave-assisted acid/base digestion and double-solvent extraction with 2 or 20 mL of 2:1 (v/v) dichloromethane/hexane, with or without subsequent solid-phase extraction (SPE) cleanup. Samples were analyzed by liquid chromatography tandem mass spectrometry. Analyte recoveries and reproducibility were highest when 100-200 μL of milk were extracted with 2 mL of dichloromethane/hexane without subsequent SPE steps. Analysis of 79 breast milk samples using this method revealed the presence of carbamates, organophosphates, pyrethroids, and imidacloprid at detection frequencies of 79-96, 53-90, 1-7, and 61%, respectively. This study demonstrates the feasibility of a simple low-volume extraction method for measuring pesticides in human breast milk.

Triacylglycerols are preferentially oxidized over free fatty acids in heated soybean oil

In oil, free fatty acids (FFAs) are thought compared the efficiency of hydrolysis wto be the preferred substrate for lipid oxidation although triacylglycerols (TAGs) are the predominant lipid class. We determined the preferential oxidation substrate (TAGs versus FFAs) in soybean oil heated at 100 °C for 24 h, after validating a method for quantifying esterified and free lipid oxidation products (i.e., oxylipins) with mass-spectrometry. Reaction velocities and turnover (velocity per unit substrate) of FFA, and free and TAG-bound (esterified) oxylipins were determined. FFA hydrolysis rate and turnover were orders of magnitude greater (16-4217 fold) than that of esterified and free oxylipin formation. The velocity and turnover of TAG-bound oxylipins was significantly greater than free oxylipins by 282- and 3-fold, respectively. The results suggest that during heating, TAGs are preferentially oxidized over FFAs, despite the rapid hydrolysis and availability of individual FFAs as substrates for oxidation. TAG-bound oxylipins may serve as better markers of lipid oxidation.

Linoleic acid-derived 13-hydroxyoctadecadienoic acid is absorbed and incorporated into rat tissues

Linoleic acid (LNA)-derived 13-hydroxyoctadecadienoic acid (13-HODE) is a bioactive lipid mediator that regulates multiple signaling processes in vivo. 13-HODE is also produced when LNA is oxidized during food processing. However, the absorption and incorporation kinetics of dietary 13-HODE into tissues is not known. The present study measured unesterified d4-13-HODE plasma bioavailability and incorporation into rat liver, adipose, heart and brain following gavage or intravenous (IV) injection (n = 3 per group). Mass spectrometry analysis revealed that d4-13-HODE was absorbed within 20 min of gavage, and continued to incorporate into plasma esterified lipid fractions throughout the 90 min monitoring period (incorporation half-life of 71 min). Following IV injection, unesterified d4-13-HODE was rapidly eliminated from plasma with a half-life of 1 min. Analysis of tracer incorporation kinetics into rat tissues following IV injection or gavage revealed that the esterified tracer preferentially incorporated into liver, adipose and heart compared to unesterified d4-13-HODE. No tracer was detected in the brain. This study demonstrates that dietary 13-HODE is absorbed, and incorporated into peripheral tissues from esterified plasma lipid pools. Understanding the chronic effects of dietary 13-HODE exposure on peripheral tissue physiology and metabolism merits future investigation.

Quantitation of Oxylipins in Fish and Algae Oil Supplements Using Optimized Hydrolysis Procedures and Ultra-High Performance Liquid Chromatography Coupled to Tandem Mass-Spectrometry

Fish and algae oil supplements are enriched with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are precursors to oxidized fatty acids, known as oxylipins. Here, we optimized a base hydrolysis method for measuring oxylipins in oil with ultrahigh-performance liquid chromatography coupled to tandem mass-spectrometry (UPLC-MS/MS) and quantified them in fish and algae oil supplements. Hydrolysis of 2 μL of oil with sodium carbonate resulted in greater oxylipin concentrations and minimal matrix effects, compared to higher oil volumes (10, 20, and 30 μL). Oxylipin yield was higher when oil was hydrolyzed in methanol containing 0.1% acetic acid and 0.1% butylated hydroxytoluene, compared to no methanol, and using sodium hydroxide versus sodium carbonate. Oxylipins extracted from 2 μL of oil using sodium hydroxide in solvent showed that EPA-derived oxylipins were most abundant in fish oil (84-87%), whereas DHA-oxylipins were abundant in algae oil (83%). This study shows that fish and algae oils are direct sources of EPA- and DHA-derived oxylipins.

Permeability and Line-Tension-Dependent Response of Polyunsaturated Membranes to Osmotic Stresses

The lipidome of plant plasma membranes-enriched in cellular phospholipids containing at least one polyunsaturated fatty acid tail and a variety of phytosterols and phytosphingolipids-is adapted to significant abiotic stresses. But how mesoscale membrane properties of these membranes such as permeability and deformability, which arise from their unique molecular compositions and corresponding lateral organization, facilitate response to global mechanical stresses is largely unknown. Here, using giant vesicles reconstituting mixtures of polyunsaturated lipids (soy phosphatidylcholine), glucosylceramide, and sitosterol common to plant membranes, we find that the membranes adopt "janus-like" domain morphologies and display anomalous solute permeabilities. The former textures the membrane with a single sterol-glucosylceramide-enriched, liquid-ordered domain separated from a liquid-disordered phase consisting primarily of soy phosphatidylcholine. When subject to osmotic downshifts, the giant unilamellar vesicles (GUVs) respond by transiently producing well-known swell-burst cycles. In each cycle, the influx of water swells the GUV, rendering the membrane tense. Subsequent rupture of the membrane through transient poration, which localizes in the liquid-disordered phase or at the domain boundaries, reduces the osmotic stress by expelling some of the excess osmolytes (and solvent) before sealing. When subject to abrupt hypertonic stress, they deform by nucleating buds at the domain phase boundaries. Remarkably, this incipient vesiculation is reversed in a statistically significant fraction of GUVs because of the interplay with solute permeation timescales, which render osmotic stresses short-lived. This, then, suggests a novel control mechanism in which an interplay of permeability and deformability regulates osmotically induced membrane deformation and limits vesiculation-induced loss of membrane material. Interestingly, recapitulation of such dynamic morphological reconfigurability-switching between budded and nonbudded morphologies-due to the interplay of membrane permeability, which temporally reverses the osmotic gradient, and domain boundaries, which select modes of deformations, might prove valuable in endowing synthetic cells with novel morphological responsiveness.

Molecular dynamics simulations of ternary lipid bilayers containing plant sterol and glucosylceramide

An atomic-level molecular dynamics simulation was carried out to study the effects of a plant sterol (sitosterol) and glucosylceramide (GlcCer) on a 1,2-dilinoleoylposphocholine (DLiPC) membrane. Initially, a membrane containing 50mol% sitosterol was compared with that containing the same ratio of cholesterol. These simulations showed differential condensing and ordering effects of sitosterol and cholesterol, with cholesterol being slightly more efficient than sitosterol in packing the membrane more tightly to a liquid ordered phase. By incorporation of 9.3% GlcCer on DLiPC/sterol membrane no notable change was observed in terms of area per lipid, bilayer thickness, order parameter and lateral diffusion. Some clusters of GlcCer/sterol were observed at higher ratio of GlcCer (15.5%), supporting the existence of GlcCer/sitosterol-enriched L_o-domains on the nanometer scale in the plant lipid mixture.

Antibiotic Resistance Pattern and Distribution of pslA Gene Among Biofilm Producing Pseudomonas aeruginosa Isolated From Waste Water of a Burn Center

BACKGROUND

Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa.

OBJECTIVES

The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran.

MATERIALS AND METHODS

Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates.

RESULTS

Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15).

CONCLUSIONS

The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.

Inhibitory effect of Rosa damascena Mill flower essential oil, geraniol and citronellol on rat ileum contraction

Flower of Rosa damascena Mill is widely used in Iran for gastrointestinal (GI) disorders. However, its pharmacological action on ileum contraction has not been studied. In this research we have investigated ileum motility effect of essential oil of flower petals of R. damascena growing in Kashan, Iran, and two of its constituents. The essential oils obtained by hydrodistillation were investigated by a combination of GC and GC/MS. More than 34 compounds have been identified. The main constituents of the essential oil were β-citronellol (23%), nonadecane (16%), geraniol (16%) and heneicosane (5%). A portion of rat isolated ileum was suspended under 1g tension in Tyrode's solution at 37°C and gassed with O2. Effect of the R. damascena essential oil (2.5-160 μg/ml), geraniol (0.2-3.2 μg/ml) and citronellol (0.8-6.4 μg/ml) were studied on ileum contractions induced by KCl, acetylcholine (ACh) and electrical field stimulation (EFS) and compared with standard drugs atropine and loperamide. The contractile response of EFS was mediated mainly through the intramural nerve plexuses, because its response was inhibited by loperamide and partially reduced by atropine. The essential oil concentration dependently inhibited the response to KCl (IC50=67 ± 8.4μg/ml) and EFS (IC50=47 ± 10.6 μg/ml). Geraniol (IC50=1.7 ± 0.15 μg/ml for KCl) and citronellol (IC50=2.9 ± 0.3 μg/ml for KCl) also had inhibitory effect of ileum contraction and both were more potent than the essential oil. It was concluded that R. damascena essential oil mainly had an inhibitory effect on ileum contractions and geraniol and citronellol had a major role in inhibitory effect of the essential.

Effect of Rosa damascena Mill. flower extract on rat ileum

Rosa damascena flower is widely used for gastrointestinal (GI) disorders. However, its pharmacological action on isolated ileum has not been studied. In this research, the effect of extract of flower petals of R. damascena Mill. growing in Kashan, Iran, on ileum motility was investigated. Hydroalcoholic extract was prepared by percolation method. A section of rat ileum was suspended in an organ bath containing Tyrode's solution. The tissue was stimulated with electrical field stimulation (EFS), KCl and acetylcholine (ACh). The tissue was kept under 1g tension at 37°C and continuously gassed with O2. Effect of the R. damascena extract was studied on ileum contractions induced by EFS, KCl and ACh and compared with that of atropine. R. damascena extract (10-100 mg/ml) induced a contraction in rat isolated ileum while at 1mg bath concentration it had relaxant effect on rat ileum. Hydroalcoholic extract of R. damascena (1-8 mg/ml) concentration dependently inhibited ileum contraction induced by KCl (IC50=3.3 ± 0.9 mg/ml), ACh (IC50=1.4 ± 0.1 mg/ml) and EFS (IC50=1.5 ± 0.3 mg/ml). The vehicle had no significant effect on ileum contractions. From this experiment it was concluded that R. damascena extract at microgram concentrations had stimulatory effect on ileum smooth muscle. However, at milligram concentrations, it shows an inhibitory effect. This is most likely due to presence of different components in the extract. The stimulatory effect of the extract confirms its benefits for the treatment of constipation. Therefore, separation and identification of active components is recommended.

Quality of Life Assessment in Patients with Multiple Sclerosis Receiving Interferon Beta-1a: A Comparative Longitudinal Study of Avonex and Its Biosimilar CinnoVex

Background. Multiple sclerosis (MS) is an autoimmune inflammatory disease of central nervous system (CNS). MS affects quality of Life (QOL) due to physical disability and other associated problems. Disease-modifying agents like interferon beta (IFNB) have been widely utilized in this patient population; however, their frequency, route of administration, side effects, high cost, and also the question of whether they are truly beneficial for longer-term outcomes and QOL need to be further investigated. Objectives. To assess QOL in patients with multiple sclerosis receiving interferon beta-1a (Avonex or CinnoVex) and in order to compare QOL in groups receiving Avonex and CinnoVex, respectively, also, to evaluate whether the more cost-effective biosimilar form of IFNB (CinnoVex) has the same effect on QOL and can be substituted for Avonex. Methods. We conducted a 30-month, nonrandomized longitudinal study and recruited a total of 92 patients diagnosed with relapsing-remitting MS. The patients were distributed in Avonex and CinnoVex groups with 46 patients in each group. Quality of life was assessed by means of MSQOL-54 questionnaire, four times a year, at baseline and at months 4, 8, and 12 of the study. Results. Mean age ± SD was 30.5 ± 8.9 and 32.3 ± 9.0 years in Avonex and CinnoVex groups, respectively, and P value of gender was different (P value : 0.036). The physical health composite scores were 61.8 and 59.8 (P values 0.677 and 0.884) for Avonex and CinnoVex groups, in that order. The results of the study revealed no significant difference between the two groups with regard to physical health, health perception, energy, and role limitations due to physical problems, pain, sexual and social function, and physical health distress scores. Further, interferon therapy did not significantly impact patients' QOL after a year of treatment with either Avonex or CinnoVex. Conclusions. According to the present study, treatment with IFNB (Avonex or CinnoVex) did not affect QOL during a year of therapy. Further studies with longer follow-up periods are required to assess the value of interferons on long-term outcomes and patient's QOL.

Interplay between p53-family, their regulators, and PARPs in DNA repair

Abnormalities of the p53 tumor suppressor gene are among the most frequent molecular events in human neoplasia. p53 is consequently one of the most studied proteins, and is the subject of over 55,500 scientific papers. In this review, attention is focused on the functions of p53 in DNA repair. We highlight the recent progress in the analysis of protein signals to p53, including PARPs, and ubiquitination cascade proteins MDM2, CRM1, USP10 and 14-3-3σ.

Induction of the adenoma-carcinoma progression and Cdc25A-B phosphatases by the trefoil factor TFF1 in human colon epithelial cells

TFF1 is overexpressed in inflammatory diseases and human cancers of the digestive and urogenital systems. To examine the transforming potential of TFF1 in human colon epithelial cells, premalignant PC/AA/C1 adenoma cells (PC) derived from a patient with familial adenomatous polyposis (FAP) were transformed by the TFF1 cDNA and used as a model of the adenoma-carcinoma transition. Constitutive expression of TFF1 increased anchorage-independent cell growth in soft agar, and induced or potentiated the growth of colon PC-TFF1 and kidney MDCKts.src-TFF1 tumor xenografts in athymic mice. This resulted in reduction of thapsigargin-induced apoptosis and promotion of collagen type I invasion through several oncogenic pathways. Using the differential display approach to identify TFF1 target genes, we found that the dual specific phosphatases Cdc25A and B implicated in cell cycle transitions are strongly upregulated under active forms in both PC-TFF1 and HCT8/S11-TFF1 colon cancer cells. Accordingly, TFF1 expression is absent in normal human colon crypts but is induced in correlation with Cdc25a and b transcript levels and tumor grade in familial and sporadic colon adenomas and carcinomas. We propose that TFF1 and Cdc25A-B cooperate with other dominant oncogenic pathways to induce the adenoma and adenocarcinoma transitions. Agents that target TFF1/Cdc25 signaling pathways may be useful for treating patients with TFF1-positive solid tumors.

Antituberculosis agents. III. In vitro evaluation of antimycobacterial activity and cytotoxicity of some N-piperazinyl quinolone derivatives

A series of N-[2-oxo-2-(4-substitutedphenyl)ethyl]piperazinyl quinolones(1a-e,2a-e and 3a-c) and N-[2-hydroxyimino-2-(4-substitutedphenyl)ethyl]piperazinyl quinolones(1f-j,2f-j and 3d-f) were evaluated for antituberculosis activity against Mycobacterium tuberculosis H37R, using the BACTEC 460 radiometric system and BACTEC 12B medium. Active compounds were also screened by serial dilution to assess toxicity to a VERO cell line. Nine compounds were efficient antimycobacterial agents showing MIC values ranging from 0.78 to 6.25 micrograms/ml. Generally, ciprofloxacin derivatives were more active than norfloxacin and enoxacin derivatives and the oxime analogues were less active than corresponding ketones. The most selective and less toxic compound 1a was tested for efficacy in vitro in TB-infected macrophage model (EC90 = 3.68 micrograms/ml, EC99 = 9.18 micrograms/ml).

Synthesis and antibacterial activity of some novel N-substituted piperazinyl-quinolones

A series of N-substituted-piperazinyl-quinolones were synthesized and evaluated for in vitro antibacterial activity. Compounds with a 2-(2,4-dichlorophenyl)-2-oxoethyl group attached to the piperazine ring (5a-c) had similar antibacterial activity to the reference drugs, ciprofloxacin, norfloxacin and enoxacin against both Gram-positive and Gram-negative bacteria. The oximes 6a-c and 6g-i were almost less active than corresponding ketones against the tested microorganisms, however the 2,4-difluorophenyl analogues (6g-i) were more active than 2,4-dichlorophenyl derivatives (6a-c). If the hydrogen of oxime is replaced with a benzyl group (6d-f & 6j-l), in-vitro antibacterial activity was decreased against both Gram-positive and Gram-negative bacteria. Generally ciprofloxacin derivatives were more active than norfloxacin and enoxacin derivatives.

Suppression of cellular invasion by activated G-protein subunits Galphao, Galphai1, Galphai2, and Galphai3 and sequestration of Gbetagamma

It was shown previously that platelet-activating factor receptors (PAF-Rs) inhibit invasiveness of colonic and kidney epithelial cells induced by the src and Met oncogenes via a pertussis toxin-sensitive mechanism. Therefore, Madin-Darby canine kidney (MDCKts.src) cells were stably transfected with constitutively activated forms of Galphao, Galphai1, Galphai2, Galphai3 (AGalphao/i), two Gbetagamma sequestering proteins [C-terminal end of beta-adrenergic receptor kinase (ct-betaARK) and the Galphat subunit of retinal G-protein transducin], and Gbeta1-Ggamma2 subunits alone or in combination. Cellular invasion induced by src, Met, and leptin was abrogated by the AGalphao/i, ct-betaARK, and Galphat-positive clones, but was induced by coexpression of Gbeta1gamma2. In contrast, invasion stimulated by the trefoil factors (TFFs) pS2 and intestinal trefoil factor in MDCKts.src cells or human colonic epithelial cells PCmsrc and HCT8/S11 was insensitive to PAF, AGalphao, AGalphai1, and AGalphai2, but was abolished by AGalphai3 and the protease-activated receptor-1 (PAR-1) agonist thrombin receptor-activating peptide. Depletion of free Gbetagamma heterodimers by ct-betaARK resulted in a remarkable decrease of cellular adhesion and spreading on collagen matrix. Our data demonstrate the following: 1) PAF-Rs impair cellular invasion induced by src, Met, and leptin via the activation of Galphao and Galphai1 to -3; 2) invasion induced by TFFs is selectively inhibited by PAR-1 receptors and Galphai3 activation; and 3) Gbetagamma dimers are required as positive effectors of invasion pathways induced by oncogenes and epigenetic factors. Thus, redistribution of Galphao/Galphai and Gbeta/gamma heterotrimeric G-proteins by PAF-R and PAR-1 exert differential functions on positive and negative signaling pathways involved in cellular invasion and may serve as potential targets for anticancer therapy.

Activation of cellular invasion by trefoil peptides and src is mediated by cyclooxygenase- and thromboxane A2 receptor-dependent signaling pathways

We have investigated the possible functional relationships between cellular invasion pathways induced by trefoil factors (TFFs), src, and the cyclooxygenases COX-1 and COX-2. Pharmacological inhibitors of the Rho small GTPase (C3 exoenzyme), phospholipase C (U-73122), cyclooxygenases (SC-560, NS-398), and the thromboxane A2 receptor (TXA2-R) antagonist SQ-295 completely abolished invasion induced by intestinal trefoil factor, pS2, and src in kidney and colonic epithelial cells MDCKts.src and PCmsrc. In contrast, invasion was induced by the TXA2-R mimetic U-46619, constitutively activated forms of the heterotrimeric G-proteins Galphaq (AGalphaq), Galpha12, Galpha13 (AGalpha12/13), which are signaling elements downstream of TXA2-R. Ectopic overexpression of pS2 cDNA and protein in MDCKts.src-pS2 cells and human colorectal cancer cells HCT8/S11-pS2 initiate distinct invasion signals that are Rho independent and COX and TXA2-R dependent. We detected a marked induction of COX-2 protein and accumulation of the stable PGH2/TXA2 metabolite TXB2 in the conditioned medium from cells transformed by src. This led to activation of the TXA2-R-dependent invasion pathway, which is monitored via a Rho- and Galpha12/Galpha13-independent mechanism using the Galphaq/PKC signaling cascade. These findings identify a new intracrine/paracrine loop that can be monitored by TFFs and src in inflammatory diseases and progression of colorectal cancers.

Induction of scattering and cellular invasion by trefoil peptides in src- and RhoA-transformed kidney and colonic epithelial cells

Trefoil factors (TFFs) are protease-resistant peptides that promote epithelial cell migration and mucosal restitution during inflammatory conditions and wound healing in the gastrointestinal tract. To date, the molecular mechanism of TFFs action and their possible role in tumor progression are unclear. In the present study, we observed that premalignant human colonic PC/AA/C1 and canine kidney MDCK epithelial cells are not competent to invade collagen gels in response to exogenously added TFFs (pS2, spasmolytic polypeptide, and intestinal trefoil factor). In contrast, activated src and RhoA exert permissive induction of invasion by the TFFs that produce similar parallel dose-response curves in src-transformed MDCKts.src and PCmsrc cells (EC50=20-40 nM). Cell scattering is also induced by TFFs in MDCKts.src cells. Stable expression of the pS2 cDNA promotes constitutive invasiveness in MDCKts.src-pS2 cells and human colonic HCT8/S11-pS2 cells established from a sporadic tumor. Furthermore, we found that TFF-mediated cellular invasion is dependent of several signaling pathways implicated in cell transformation and survival, including phosphoinositide PI3'-kinase, phospholipase C, protein kinase C, and the rapamycin target TOR. Constitutive and intense expression of pS2 was revealed by Western blot analyses and immunohistochemistry in human colorectal tumors and their adjacent control mucosa during the neoplastic progression, from the adenoma to the liver metastases. Our studies indicated that TFFs can be involved in cell scattering and tumor invasion via autocrine loops and may serve as potential targets in the control of colon cancer progression.

Phenotypic and functional characterization of human thymic stromal cell lines

To establish new tools for studying human thymic stromal cells, we transfected adherent cells from a human postnatal thymus using a plasmid encoding SV40 large T antigen. Among the cell lines obtained, we characterized four epithelial cell lines (LT-TEC1 to LT-TEC4) and one thymic myoid cell line (MITC). Several morphological, functional and phenotypic differences were observed between these 2 cell types. Epithelial cells were heterogeneous and larger than myoid cells. Untreated LT-TEC lines expressed MHC class I, ICAM-1 and LFA-3 antigens and not MHC class II antigens, similarly to primary thymic epithelial cells (PTEC), while MITC line expressed only class I and LFA-3 antigens. After IFN-gamma treatment, MHC class II and ICAM-1 antigens were markedly upregulated in LT-TEC lines but not in MITC, indicating the absence or a dysfunction of regulatory factors in MITC line. Myoid cells expressed mRNA for all the subunits of the acetylcholine receptor (AChR) while epithelial cells expressed only the alpha, beta and epsilon subunits. Strikingly, LT-TEC produced much more C-C chemokines and IL-6 than MITC cells, while these latter produced higher levels of IL-8 and TNF-alpha. Altogether, these results reveal phenotypic and functional differences between these two stromal cell types, suggesting a potential involvement of myoid cells in the thymic function.

Impaired contractile performance of cultured rabbit ventricular myocytes after adenoviral gene transfer of Na(+)-Ca(2+) exchanger

Na(+)-Ca(2+) exchanger (NCX) gene expression is increased in the failing human heart. We investigated the hypothesis that upregulation of NCX can induce depressed contractile performance. Overexpression of NCX was achieved in isolated rabbit ventricular myocytes through adenoviral gene transfer (Ad-NCX). After 48 hours, immunoblots revealed a virus dose-dependent increase in NCX protein. Adenoviral beta-galactosidase transfection served as a control. The fractional shortening (FS) of electrically stimulated myocytes was analyzed. At 60 min(-1), FS was depressed by 15.6% in the Ad-NCX group (n=143) versus the control group (n=163, P:<0.05). Analysis of the shortening-frequency relationship showed a steady increase in FS in the control myocytes (n=26) from 0.027+/-0.002 at 30 min(-1) to 0. 037+/-0.002 at 120 min(-1) (P:<0.05 versus 30 min(-1)) and to 0. 040+/-0.002 at 180 min(-1) (P:<0.05 versus 30 min(-1)). Frequency potentiation of shortening was blunted in NCX-transfected myocytes (n=27). The FS was 0.024+/-0.002 at 30 min(-1), 0.029+/-0.002 at 120 min(-1) (P:<0.05 versus 30 min(-1), P:<0.05 versus control), and 0. 026+/-0.002 at 180 min(-1) (NS versus 30 min(-1), P:<0.05 versus control). Caffeine contractures, which indicate sarcoplasmic reticulum Ca(2+) load, were significantly reduced at 120 min(-1) in NCX-transfected cells. An analysis of postrest behavior showed a decay of FS with longer rest intervals in control cells. Rest decay was significantly higher in the Ad-NCX group; after 120 seconds of rest, FS was 78+/-4% in control and 65+/-3% in the Ad-NCX group (P:<0.05) relative to steady-state FS before rest (100%). In conclusion, the overexpression of NCX in rabbit cardiomyocytes results in the depression of contractile function. This supports the hypothesis that upregulation of NCX can result in systolic myocardial failure.

Decreased ADP-ribosylation of the Galpha(olf) and Galpha(s) subunits by high glucose in pancreatic B-cells

In HIT-T15 insulinoma B-cells incubated in presence of [(32)P]NAD, we identified by autoradiography and immunoblotting ADP-ribosylation (ADP-R) of the trimeric G-protein Galpha(s) and Galpha(olf) subunits (45 kDa) induced by cholera toxin in M1 (120,000g) and M2 (70,000g) subcellular fractions containing plasma membranes, insulin granules, and mitochondria. This ADP-R indicates that these two fractions contain functionally competent Galpha subunits for adenylyl cyclase activation. Prolonged exposure of HIT-T15 cells to high glucose (25 mM instead of 6 mM) specifically reduced the ADP-R in Galpha(s) and Galpha(olf) subunits in the M1 fraction only, despite the clear increase of their accumulation in this compartment. A similar alteration in the ADP-R of the M1-associated Galpha(s) and Galpha(olf) subunits was observed in pancreatic islets isolated from fasted and fed rats. These results may explain, at least in part, the undesirable effects of sustained hyperglycemia on the cAMP-dependent process of insulin secretion in diabetes.

Cellular and subcellular expression of Golf/Gs and Gq/G11 alpha-subunits in rat pancreatic endocrine cells

We studied the cellular and subcellular localization of Galpha-subunits in pancreas by immunocytochemistry. Golfalpha and G11alpha were specifically localized in islet insulin B-cells and glucagon A-cells, respectively. Gsalpha and Gqalpha labeling was more abundant in B-cells. The presence of Golfalpha in B-cells was confirmed by in situ hybridization. In B-cells, Golfalpha and Gsalpha were found in the Golgi apparatus, plasma membrane (PM) and, remarkably, in mature and immature insulin secretory granules, mainly at the periphery of the insulin grains. Gqalpha was detected on the rough endoplasmic reticulum (RER) near the Golgi apparatus. In A-cells, the Galpha-subunits were mostly within the glucagon granules: G11alpha gave the strongest signal, Gsalpha less strong, Gq was scarce, and Golf was practically absent. Gqalpha and Gsalpha immunoreactivity was detected in acinar cells, although it was much weaker than that in islet cells. The cell-dependent distribution of the Galpha-subunits indicates that the stimulatory pathways for pancreatic function differ in acinar and in islet B- and A-cells. Furthermore, the G-protein subunits in islet cell secretory granules might be functional and participate in granule trafficking and hormone secretion.

Bone marrow stromal cell-mediated gene therapy for hemophilia A: in vitro expression of human factor VIII with high biological activity requires the inclusion of the proteolytic site at amino acid 1648

To evaluate the potential of the ex vivo bone marrow stromal cell (BMSC) system as a gene therapy for hemophilia A, we studied the in vitro expression of human factor VIII (hFVIII) in canine BMSCs following transfection with plasmid vectors and transduction with retroviral vectors. Vectors were composed of B domain-deleted forms of hFVIII that either retain or delete the proteolytic site at amino acid 1648. On transfection of BMSCs, vectors supported expression and secretion of similar levels of up to 386 mU/10(6) cells/24 hr, even though only 3-9% of the cells expressed hFVIII while 42-48% of transfected cells harbored plasmid vector. Much higher percentages (approximately 70%) of cells expressing hFVIII were achieved when BMSCs were transduced by retroviral vectors, resulting in expression and secretion as high as 1000-4000 mU/10(6) cells/24 hr. Western analysis demonstrated that the B domain-deleted forms possessing the proteolytic site were secreted predominantly as heavy and light chain heterodimers that resemble native forms found in plasma. In contrast, the hFVIII lacking the proteolytic site was expressed mostly as unprocessed, single heavy-light chains. Both hFVIII forms were correctly cleaved and activated by thrombin. The proteolyzed hFVIII form possessed > or = 93% normal biological activity while the unproteolyzed form possessed consistently less than 55% normal biological activity and was therefore considered less suitable for therapeutic application. These results demonstrate that the BMSC system has potential utility in gene therapy for hemophilia A and stress the importance of selecting the appropriate hFVIII structure for prospective clinical use.

Stimulatory transducing systems in pancreatic islet cells

We have determined the cellular distribution of different alpha subtypes of G proteins and adenylyl cyclase (AC) isoforms in endocrine, exocrine, and established pancreatic cell lines. VIP, PACAP, and tGLP-1 receptor proteins are expressed to varying extents in A and B cells, whereas the expression of G alpha subunits is cell specific. Thus, G(olf) alpha is detected in normal rodent B cells and immortalized pancreatic B cell lines, whereas Gs alpha is more ubiquitously expressed. The cellular density of AC isoforms labeling (I, II, III, IV, V/VI) is also islet cell-specific and their distribution is age- and species-dependent. The identification of numerous signaling molecule subtypes, together with the discovery of their specific subcellular distribution, will help the functional characterization of their intraregulatory pathways, leading to the extrusion of insulin or glucagon secretory granules, and those leading to differentiation and apoptosis of islet cells.

Effect of blood on rapid urease testing of gastric mucosal biopsy specimens

BACKGROUND

The effect of blood on rapid urease tests is uncertain. We assessed the effect of soaking gastric biopsy specimens in blood on the results of both agar gel (CLOtest) and strip (Pyloritek) rapid urease tests.

METHODS

One hundred patients undergoing endoscopy had four adjacent biopsy specimens taken from normal appearing mucosa in the antrum. Two biopsies were soaked in blood for 1 minute; one specimen was placed on a CLOtest and one on a Pyloritek. The other two biopsy specimens were placed on CLOtest and Pyloritek without soaking in blood. The same process was performed with four adjacent biopsy specimens from the gastric body. CLOtests were read at 1, 4, and 24 hours; Pyloritek results were read at 1 hour.

RESULTS

The number of positive tests for the blood-soaked and standard biopsy specimens were comparable at all times for both rapid urease tests. Discordant results between the blood-soaked and standard specimens were seen in 17 of 400 test comparisons (4%): in 8 of these only the blood-soaked specimen was positive, and in 9 only the standard specimen was positive.

CONCLUSIONS

"Contamination" of biopsy specimens with blood does not alter rapid urease test results.

Randomized comparison of ranitidine bismuth citrate-based triple therapies for Helicobacter pylori

OBJECTIVES

In an attempt to increase the efficacy and simplicity of FDA-approved regimens for Helicobacter pylori, we studied (1) addition of an inexpensive antibiotic (amoxicillin) to twice-daily ranitidine bismuth citrate (RBC)-clarithromycin dual therapy, and (2) substitution of RBC for bismuth subsalicylate + H2-receptor antagonist in bismuth-based triple therapy.

METHODS

Subjects with previously untreated Helicobacter pylori infection documented by 13C-urea breath test plus either endoscopic biopsy or serology were randomly assigned to a 2-wk course of (1) RBC 400 mg b.i.d., amoxicillin 1 g b.i.d., and clarithromycin 500 mg b.i.d. (RAC), or (2) RBC 400 mg b.i.d., metronidazole 250 mg t.i.d., and tetracycline 500 mg t.i.d. (RMT). Repeat breath test was performed 4 wk after the completion of therapy.

RESULTS

Intent-to-treat and per-protocol cure rates for RAC were 46 of 50 patients (92%) and 45 of 47 patients (96%); for RMT they were 40 of 50 patients (80%) and 37 of 42 patients (88%). Study drugs were stopped due to side effects in three patients (6%) taking RAC and six patients (12%) taking RMT.

CONCLUSIONS

Twice-daily RBC-based triple therapy with clarithromycin and amoxicillin produces Helicobacter pylori eradication rates over 90%, which is comparable to rates seen with proton pump inhibitor-based triple therapies. RBC also may be substituted for bismuth subsalicylate and an + H2-receptor antagonist in standard bismuth-based triple therapy.

Enhanced growth of canine bone marrow stromal cell cultures in the presence of acidic fibroblast growth factor and heparin

The ex vivo establishment, expansion, transduction, and reintroduction of autologous bone marrow stromal cells offers a potential efficacious system for somatic cell gene therapy. It is likely that any ex vivo system will require the use of large numbers of cells which express high levels of transgene products. We present a method for routine expansion of canine bone marrow stromal cells, established from initial 10-20 ml marrow aspirates, to greater than 10(9) cells. This high level expansion of cell cultures uses the stimulatory effect of acidic fibroblast growth factor (aFGF) and heparin. In the absence of these factors, stromal cell cultures grow actively for only 1 to 2 passages, become flattened in morphology, and expand to only 10(8) cells. In the presence of heparin (5 U/ml), aFGF exerts its effect over a wide range of concentrations (0.1-10 ng/ml) in a dose-dependent manner. The stimulatory effect is dependent on the presence of both aFGF and heparin. Immunocytochemical and cytochemical analyses phenotypically characterize these stromal cells as bone marrow stromal myofibroblasts. Stromal cells grown in the presence of aFGF and heparin grow actively and maintain a fibroblast-like morphology for a number of passages, transduce efficiently with a human growth hormone (hGH) expression vector, and express and secrete high levels of hGH. Human marrow stromal cells were also established and expanded by the same culture method. This culture method should be of great value in somatic cell gene therapy for the delivery of secreted gene products to the plasma of large mammals.

Systemic delivery of human growth hormone or human factor IX in dogs by reintroduced genetically modified autologous bone marrow stromal cells

Canine bone marrow stromal cells were expanded to numbers in excess of 10(9) cells from the initial 10-20 ml of marrow aspirates and transfected to express high levels of human growth hormone (hGH) in vitro. Ex vivo-modified marrow stromal cells were used in a gene therapy model system for the systemic delivery of transgene products in dogs. Adherent bone marrow stromal cell cultures, established and expanded from iliac crest marrow aspirates from each of 8 dogs, were transfected with a hGH gene plasmid expression vector and shown to express from 0.54-3.84 micrograms/10(6) cells per 24 hr hGH in vitro. The transfected plasmid vector does not possess a eukaryotic origin of replication nor does it possess sequences required for efficient integration into the host cell genome. As such, expression was expected to be transient. Transfected cells were autologously reintroduced into each dog by either infusion into a foreleg vein or directly into iliac crest marrow. In two cases, the stromal cells were cryopreserved following transfection, and subsequently thawed and infused. In one case, the expanded stromal cells were first cryopreserved, and then thawed, recultured, transfected, and infused. Reintroduced cell numbers ranged from 2.2 x 10(7) to 2.6 x 10(9), with total hGH expression capacities ranging from 62 to 1,400 micrograms/24 hr. Plasma of each of the dogs contained detectable hGH for a mean of 3.1 days (SD +/- 0.8 day) ranging from 2 to 5 days following reinfusion of cells. Peak plasma levels ranged from 0.10 to 1.76 ng/ml. Similar hGH expression values, based upon total expression capacity of the cells infused and dog body weight, were obtained for all dogs. Vector-modified stromal cells were detectable, by polymerase chain reaction (PCR) analysis, in the peripheral circulation following reinfusion in all 4 dogs analyzed. In 3 of the dogs, modified stromal cells were detected for 8.5-15 weeks. In addition, modified stromal cells were detected in iliac crest marrow of 2 dogs for 9 and 13 weeks, respectively, following reinfusion. In another experiment, cultured bone marrow stromal cells were transfected with a human factor IX (hFIX) plasmid vector. Modified cells (5.57 x 10(8)), with a total hFIX expression capacity of 281 micrograms/24 hr, were reinfused, resulting in detectable hFIX in plasma continuously for 9 days with a peak level of 8 ng/ml on day 1. These results demonstrate that the ex vivo bone marrow stromal cell system is a potentially powerful method by which to deliver secreted transgene product to the systemic circulation of large animals.