Survey of Flea Infestation in Dogs in Different Geographical Regions of Iran

Medically important arthropods, including fleas, play an important role in causing clinical disorders and disease in man and domestic animals. This study was conducted to determine the seasonal flea infestations for domestic dogs from different geographic regions of Iran. A total of 407 fleas, belonging to 5 different species, were recovered from 83 domestic dogs from 3 regions. There was a distinctive pattern of species distribution and infestations with the highest infestation rates observed in a temperate climate and higher rainfall. Additionally, fleas were observed over all seasons, except February and March, with the highest infestation rate observed in August (24.7%) and the lowest rate in January (1.7%). They also parasitize dogs with a different spectrum of species. The cat flea, Ctenocephalides felis (67.5%), exhibited the highest prevalence among all flea species found on dogs. Thus, climatic conditions and seasonal patterns impact on flea infestation and must be considered in developing control programs.     

Males Prefer Small Females in a Dichotomous Choice Test in the Poeciliid Fish Heterandria formosa

Male choice is expected to evolve when females differ in quality, even if male investment in each mating is low. The family Poeciliidae is an example of fishes in which males show little parental investment as they only provide sperm. Up until now, a preference for large females has been found in all species studied. Here we show that unexpectedly, males of the least killifish (Heterandria formosa) prefer to interact with small instead of large females in a dichotomous male choice test, even though large females are more fecund. During a free‐swimming choice experiment, males did not discriminate between females based on their size. We suggest that this unique preference for small females, or the lack of preference for large females, results from strong first male sperm precedence in this species. Smaller females are younger and therefore more likely to be virgin, which probably makes them more profitable mates for males. When presented with a virgin and a mated female of similar size, males showed no preference for either type. This suggests that males do not use pheromone cues to assess female mating status but that they are likely to use female size as a proxy for it.     

Highly efficient and selective methoxymethylation of alcohols and phenols catalyzed by high-valent tin(IV) porphyrin

An efficient and selective method for methoxymethylation of alcohols and phenols with formaldehyde dimethyl acetal (FDMA) catalyzed by electron deficient tin(IV)tetraphenylporphyrinato trifluoromethanesulfonate, [Sn^IV(TPP)(OTf)₂], is reported. A variety of primary, secondary and tertiary alcohols as well as phenols were converted to their corresponding methoxymethyl ethers with FDMA in the presence of a high-valent tin(IV) porphyrin. This catalyst can be used for selective methoxymethylation of primary, secondary and tertiary alcohols in the presence of phenols or tertiary alcohols. The present method offers several advantages such as short reaction times, high yields, simple procedure, selectivity and applicability for both alcohols and phenols.     

A minimal model for multiple epidemics and immunity spreading

Pathogens and parasites are ubiquitous in the living world, being limited only by availability of suitable hosts. The ability to transmit a particular disease depends on competing infections as well as on the status of host immunity. Multiple diseases compete for the same resource and their fate is coupled to each other. Such couplings have many facets, for example cross-immunization between related influenza strains, mutual inhibition by killing the host, or possible even a mutual catalytic effect if host immunity is impaired. We here introduce a minimal model for an unlimited number of unrelated pathogens whose interaction is simplified to simple mutual exclusion. The model incorporates an ongoing development of host immunity to past diseases, while leaving the system open for emergence of new diseases. The model exhibits a rich dynamical behavior with interacting infection waves, leaving broad trails of immunization in the host population. This obtained immunization pattern depends only on the system size and on the mutation rate that initiates new diseases.     

Efficacy and safety of rabeprazole, amoxicillin, and gatifloxacin after treatment failure of initial Helicobacter pylori eradication

OBJECTIVES: To evaluate the efficacy of a 7-day regimen of gatifloxacin (400 mg daily), amoxicillin (1 g twice a day), and rabeprazole (20 mg twice a day) in the secondary eradication of Helicobacter pylori infection. METHODS: Eligible patients with persistent infection following one or more conventional clarithromycin-containing triple therapies were enrolled in this open-label trial. Eradication of infection was documented by (14)C-urea breath test a minimum of 4 weeks after therapy and 2 weeks off any acid suppressive therapy. Culture of H. pylori and in vitro susceptibility testing to amoxicillin, clarithromycin, and gatifloxacin was done in cases of failed eradication. RESULTS: A total of 45 patients (22 females:23 males; mean age 44.5 +/- 13 years) were enrolled. Eradication occurred in 38 patients [both per-protocol (PP) and intention-to-treat analysis: 84.4%; 95% CI: 74-95%]. No significant adverse effects were reported. In vitro susceptibility testing showed no secondary resistance to gatifloxacin or amoxicillin in any of the seven nonresponders. Smoking, age, and sex were not predictors of potential eradication failure. CONCLUSIONS: A 7-day regimen of gatifloxacin, rabeprazole, and amoxicillin is effective after failed eradication therapy for H. pylori and does not appear to result in secondary resistance. This combination is simple, well tolerated, and may lead to higher compliance and lower costs.     

Association of the X-linked lymphoproliferative disease gene product SAP/SH2D1A with 2B4, a natural killer cell-activating molecule, is dependent on phosphoinositide 3-kinase

Natural killer (NK) cells express an activating receptor, 2B4, that enhances cellular cytotoxicity. Upon NK cell activation by ligation of 2B4, the intracellular domain of 2B4 associates with the X-linked lymphoproliferative disease (XLP) gene product, signaling lymphocytic activation molecule-associated protein/SH2D1A (SAP/SH2D1A). Defective intracellular association of 2B4 with mutated SAP/SH2D1A is likely to underlie the defects in cytotoxicity observed in NK cells from patients with XLP. We report here a role for phosphoinositide 3-kinase (PI3K) in the recruitment and association of SAP/SH2D1A to 2B4 in human NK cells. The activation of normal NK cells by ligation of 2B4 leads to the phosphorylation of 2B4, recruitment of SAP/SH2D1A, and association of the p85 regulatory subunit of PI3K. The inhibition of PI3K enzymatic activity with either wortmannin or LY294002 prior to 2B4 ligation does not alter the association of 2B4 with the p85 subunit but prevents the recruitment of SAP/SH2D1A to 2B4. In addition, PI3K inhibitors significantly diminish the cytotoxic function of primary NK cells. This observed inhibition of cytotoxicity, present in normal NK cells, was less apparent or absent in NK cells derived from a patient with XLP. These data indicate that the cytotoxicity of activated NK cells is mediated by the association of 2B4 and SAP/SH2D1A, and that this association is dependent upon the activity of PI3K.     

Investigation of Microstructure and Corrosion of TiNbTaZrMo High-Entropy Alloy in the Simulated Body Fluid

Microstructures and corrosion of TiNbTaZrMo(Ti₂₀Nb₂₀Ta₂₀Zr₂₀Mo₂₀)High-Entropy Alloy(HEA)were investigated in the Simu-lated Body Fluid(SBF).Microstructure of this alloy was investigated by X-Ray Difiraction(XRD)and Scanning Electron Microscopy(SEM)techniques.Our observations confirmed the presence of two bcc phases as the major matrix as well as another minor phase in themicrostructure of the alloy.Concentration of some elements,such as tantalum,niobium,and molybdenum in the dendritic branches and thepresence of zirconium and titanium in the inter-dendritic branches were clearly evidenced by Energy Dispersive X-ray(EDX)analysis.Given importance of corrosion of implant alloys in the human's body,elctrochemical impedance and cyclic polarization tests werepcerformed on the alloy in SBF.Through the corrosion tests,corrosion potential,current,and resistance were obtained as E_corr=-0.42 V,i_corr=0.34μA·cm^-2,and R_p=27.44 k ohm·cm²,respectively.The results revealed that the rate of corrosion in TiNbTaZrMo HEA is about 26 times better than that of Ti₆Al₄V alloy.Also,both alloys had no pitting corrosion in the SBF solution.     

Measurement of menadione in urine by HPLC

Menadione is a metabolite of vitamin K that is excreted in urine. A high performance liquid chromatography (HPLC) method using a C₃₀ column, post-column zinc reduction and fluorescence detection was developed to measure urinary menadione. The mobile phase was composed of 95% methanol with 0.55% aqueous solution and 5% DI H₂O. Menaquinone-2 (MK-2) was used as an internal standard. The standard calibration curve was linear with a correlation coefficient (R²) of 0.999 for both menadione and MK-2. The lower limit of quantification (LLOQ) was 0.3 pmole menadione/mL urine. Sample preparation involved hydrolysis of menadiol conjugates and oxidizing the released menadiol to menadione. Using this method, urinary menadione was shown to increase in response to 3 years of phylloquinone supplementation. This HPLC method is a sensitive and reproducible way to detect menadione in urine.     

Rapid and efficient oxidative decarboxylation of carboxylic acids with sodium periodate catalyzed by manganese (III) Schiff base complexes

Rapid and efficient oxidative decarboxylatoin of alpha-aryl carboxylic acids was observed. In the chemical system containing Mn(III)-salophen complex as catalyst, carboxylic acids are converted efficiently to the corresponding carbonyl derivatives with sodium periodate. The ability of various Schiff base complexes in the oxidative decarboxylation of carboxylic acids was also investigated.