Design,synthesis, antibacterial activity and physicochemical parameters of novel N-4-piperazinyl derivatives of norfloxacin

We report herein the synthesis of some N-Mannich bases in addition to different N-4 substituents of norfloxacin. The antibacterial activities of the newly synthesized compounds were evaluated and correlated with their physicochemical properties. Results revealed that some of the tested compounds exhibited better inhibitory activities than the reference antibiotic norfloxacin against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus strains. Correlation results showed that there is no single physicochemical parameter that can determine the effect of N-4 piperazinyl group on the activity of these fluoroquinolones, where lipophilicity, molecular mass and electronic factors may influence the activity.     

Schistosoma haematobium (Egyptian strain): rate of development and effect of praziquantel treatment

This study investigates the development of the Egyptian strain of Schistosoma haematobium and the resultant immunohistopathology and biochemical changes in organs affected. In addition, the response of different developmental stages of S. haematobium worms to praziquantel (PZQ) was examined. Schistosoma haematobium-infected hamsters were classified into 4 groups and were treated at day 35, 55, 75, and 95 postinfection (PI), respectively. Each group was subdivided into 3 subgroups. Two of them were treated orally with PZQ (300 mg/kg or 500 mg/kg divided equally on 2 consecutive days), and the third group was left without treatment. Treated groups were killed 20 days posttreatment. Infection with S. haematobium became patent 73 days PI; tissue egg load and worm fecundity were higher at 95 days and maximal 115 days PI, with an oogram pattern comparable to that in Schistosoma mansoni infection. In the liver, small cellular granulomas were observed 75 days PI, with preponderance of CD4+ T-cell phenotypes. In the urinary bladder, only submucosal focal Brunn's-nest formation and angiogenesis without typical granulomas were observed. Ninety-five and 115 days PI, confluent granulomata with multiple eggs in the center were observed in the liver and urinary bladder, with a preponderance of CD8+ positive T cells in the liver and hyperplasia of the urinary bladder epithelium with cystitis cystica and papillae formation. One hundred percent worm eradication was recorded with the higher dose of PZQ in animals treated 75 and 95 days PI. In conclusion, in spite of the long prepatent period of the Egyptian strain of S. haematobium, sensitivity to PZQ was recorded soon after infection. Granulomata were similar to those of S. mansoni in the livers and urinary bladders, but they were confluent with multiple eggs in the centers, hyperplasia of the urinary bladder urothelium with cystitis cystica, papillae, and Brunn's-nest formation predictive of malignant changes with no hepatocyte dysplasia.     

<Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>, the Baker’s Yeast,suppresses the growth of Ehrlich carcinoma-bearing mice

This study was undertaken to evaluate the effectiveness and mechanisms of anti-tumor activity of Baker’s yeast, Saccharomyces cerevisiae, in immunocompetent mice. Swiss albino mice were inoculated intramuscularly in the right thigh with Ehrlich Ascites Carcinoma (EAC) cells. At day 8, mice bearing Solid Ehrlich Carcinoma tumor (SEC) were intratumorally (IT) injected with killed S. cerevisiae (10 × 10⁶ and 20 × 10⁶ cells) for 35 days. Histopathology of yeast-treated mice showed extensive tumor degeneration, apoptosis, and ischemic (coagulative) and liquefactive necrosis. These changes are associated with a tumor growth curve that demonstrates a significant antitumor response that peaked at 35 days. Yeast treatment (20 × 10⁶ cells) three times a week resulted in a significant decrease in tumor volume (TV) (67.1%, P < 0.01) as compared to PBS-treated mice. The effect was determined to be dependent on dose and frequency. Yeast administered three and two times per week induced significant decrease in TV as early as 9 and 25 days post-treatment, respectively. Administration of yeast significantly enhanced the recruitment of leukocytes, including macrophages, into the tumors and triggered apoptosis in SEC cells as determined by flow cytometry (78.6%, P < 0.01) at 20 × 10⁶ cells, as compared to PBS-treated mice (42.6%). In addition, yeast treatment elevated TNF-α and IFN-γ plasma levels and lowered the elevated IL-10 levels. No adverse side effects from the yeast treatment were observed, including feeding/drinking cycle and life activity patterns. Indeed, yeast-treated mice showed significant final body weight gain (+21.5%, P < 0.01) at day 35. These data may have clinical implications for the treatment of solid cancer with yeast, which is known to be safe for human consumption.     

Resting CD4+ effector memory T cells are precursors of bystander-activated effectors: a surrogate model of rheumatoid arthritis synovial T-cell function

Background

Previously we described a system whereby human peripheral blood T cells stimulated for 8 days in a cytokine cocktail acquired effector function for contact-dependent induction of proinflammatory cytokines from monocytes. We termed these cells cytokine-activated (Tck) cells and found that the signalling pathways elicited in the responding monocytes were identical whether they were placed in contact with Tck cells or with T cells isolated from rheumatoid arthritis (RA) synovial tissue.

Methods

Here, using magnetic beads and fluorescence-activated cell sorting, we extensively phenotype the Tck effector cells and conclude that effector function resides within the CD4⁺CD45RO⁺, CCR7^-, CD49d^high population, and that these cells are derived from the effector memory CD4⁺ T cells in resting blood.

Results

After stimulation in culture, these cells produce a wide range of T-cell cytokines, undergo proliferation and differentiate to acquire an extensively activated phenotype resembling RA synovial T cells. Blocking antibodies against CD69, CD18, or CD49d resulted in a reduction of tumour necrosis factor-α production from monocytes stimulated with CD4⁺CD45RO⁺ Tck cells in the co-culture assay. Moreover, blockade of these ligands also resulted in inhibition of spontaneous tumour necrosis factor-α production in RA synovial mononuclear cell cultures.

Conclusion

Taken together, these data strengthen our understanding of T-cell effector function, highlight the multiple involvement of different cell surface ligands in cell-cell contact and, provide novel insights into the pathogenesis of inflammatory RA disease.     

Keratinophilic Fungi Recovered from Muddy Soil in Cairo Vicinities,Egypt

One hundred samples of muddy soil were collected from seven areas in the vicinity of Cairo and screened for the presence of keratinophilic fungi by using hair baiting isolation technique. Forty isolates of keratinophilic fungi were recovered and identified by recognition of their cultures, macro- and micromorphological features. Their physiological and molecular characteristics were studied by determination of their ubiquinone (Coenzyme Q) composition and DNA sequences of (ITS1-5.8S-ITS2) and 18S rRNA region sequences. The Keratinophilic isolates were identified as Chrysosporium carmichaelii, C. queenslandicum, C. zonatum, C. indicum, Aphanoascus mephitalis, and Uncinocarpus reesii. Chrysosporium zonatum was the most prevalent species and represented 42.5% of the total number of isolates. Each of C. carmichaelii and C. queenslandicum were equal in their prevalence and represented 15%. C. indicum comes next constituting 12.5%; followed by Uncinocarpus reesii which represented 10%. The least prevalent species in our study was Aphanoascus mephitalis, which was represented only 5% of the total keratinophilic isolates.     

The role of cryptochrome 2 in flowering in Arabidopsis

We have investigated the genetic interactions between cry2 and the various flowering pathways in relation to the regulation of flowering by photoperiod and vernalization. For this, we combined three alleles of CRY2, the wild-type CRY2-Landsberg erecta (Ler), a cry2 loss-of-function null allele, and the gain-of-function CRY2-Cape Verde Islands (Cvi), with mutants representing the various photoreceptors and flowering pathways. The analysis of CRY2 alleles combined with photoreceptor mutants showed that CRY2-Cvi could compensate the loss of phyA and cry1, also indicating that cry2 does not require functional phyA or cry1. The analysis of mutants of the photoperiod pathway showed epistasis of co and gi to the CRY2 alleles, indicating that cry2 needs the product of CO and GI genes to promote flowering. All double mutants of this pathway showed a photoperiod response very much reduced compared with Ler. In contrast, mutations in the autonomous pathway genes were additive to the CRY2 alleles, partially overcoming the effects of CRY2-Cvi and restoring day length responsiveness. The three CRY2 alleles were day length sensitive when combined with FRI-Sf2 and/or FLC-Sf2 genes, which could be reverted when the delay of flowering caused by FRI-Sf2 and FLC-Sf2 alleles was removed by vernalization. In addition, we looked at the expression of FLC and CRY2 genes and showed that CRY2 is negatively regulated by FLC. These results indicate an interaction between the photoperiod and the FLC-dependent pathways upstream to the common downstream targets of both pathways, SOC1 and FT.     

Assessment of the presence of Salmonella spp. in Egyptian dairy products using various detection media

AIMS: To make a preliminary assessment of the incidence of Salmonella in Egyptian dairy products, and to investigate the effectiveness of various protocols for the detection of the pathogen in these products. METHODS AND RESULTS: Samples of milk and related dairy products were randomly collected from local markets and examined for the presence of Salmonella. While most samples were free of the organism, isolates of Salmonella enterica subsp. enterica serovar Typhimurium PT 8 could be recovered from 'matared' cream specimens. These isolates were susceptible to antibiotics usually used to challenge infections caused by Salmonella. A combination of buffered peptone water, Muller-Kauffman tetrathionate broth, and brilliant green phenol red agar gave the best results for the detection of the pathogen. Selenite-cystine broth and Hektoen enteric agar were ineffective as an enrichment and a plating medium, respectively, in the isolation of Salmonella. A modified identification strategy that reduces the burden of serological testing of presumptive isolates is proposed. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: 'Matared' cream could be a vehicle for transmitting Salmonella. Using the above combination of media, beside the suggested modified confirmatory procedure, should increase the effectiveness and ease of the detection of Salmonella in milk and dairy products.     

The alpha1-adrenergic receptor not the DA(1)-dopaminergic receptor mediates cyclosporine-SKF38393 renovascular interaction

In this study, we investigated the effect of acute exposure to cyclosporine A (CyA) on renal vasodilations evoked by the DA(1) dopaminergic agonist SKF38393 and whether dopamine DA(1) receptors are directly involved in the interaction. Changes evoked by CyA in SKF38393 vasodilations were evaluated in phenylephrine-preconstricted isolated perfused rat kidneys in the absence and presence of SCH23390, a DA(1) receptor antagonist. SKF38393 (3 x 10(-8) to 3 x 10(-6) mol) produced dose-dependent reductions in the renal perfusion pressure that were significantly attenuated in tissues pretreated with SCH23390 or CyA. Unlike SKF38393, the vasodilatory action of sodium nitroprusside, a nitrovasodilator, was not altered by CyA. The attenuating effect of CyA on SKF38393 vasodilations was preserved in preparations pretreated with SCH23390, suggesting that sites other than DA(1) receptors may be involved in CyA-SKF38393 interaction. The study was then extended to investigate the possible involvement of renal alpha1-adrenoceptors in the interaction. Blockade of alpha(1)-adrenoceptors by prazosin (30 nmol/L) significantly reduced the vasodilatory effect of SKF38393 and virtually abolished the CyA-induced attenuation of SKF38393 responses. Further, CyA failed to alter SKF38393 vasodilations when the renal tone was raised with prostaglandin F2alpha (PGF2alpha), a vasoconstrictor whose effect is independent of alpha(1)-adenoceptors. Together, these findings support earlier reports that both DA(1) and alpha(1)-receptors mediate the renal vasodilatory action of SKF38393 and suggest that CyA interacts selectively with the alpha(1)-receptor component to compromise SKF38393 responses.     

Peripheral interleukin-6 administration increases extracellular concentrations of serotonin and the evoked release of serotonin in the rat striatum

Previous studies have indicated that peripheral administration of interleukin-6 (IL-6) increases brain concentrations of tryptophan and 5-hydroxyindoleacetic acid (5-HIAA), the major catabolite of serotonin (5-HT). To determine whether these changes were related to increased synaptic release of 5-HT, we studied the responses to peripheral administration of IL-6 by in vivo microdialysis and in vivo amperometry. Intraperitoneal injection of recombinant IL-6 resulted in an elevation of microdialysate concentrations of 5-HT in the rat striatum. Also, amperometric measurements indicated that i.p. IL-6 enhanced the 5-HT-like signal obtained from the striatum following electrical stimulation of the dorsal raphe nucleus. These results indicate that the increases in brain concentrations of 5-HIAA observed in earlier studies indeed reflect increased synaptic release of 5-HT.     

Hydroferrate Fluid,MRN-100, Provides Protection against Chemical-Induced Gastric and Esophageal Cancer in Wistar Rats

In the current study, we examined the protective effect of hydroferrate fluid MRN-100 against the carcinogen methylnitronitrosoguanidine (MNNG)-induced gastric and esophageal cancer in rats. MRN-100 is an iron-based compound composed of bivalent and trivalent ferrates. At 33 weeks post treatment with MNNG, rats were killed and examined for the histopathology of esophagus and stomach; liver, spleen, and total body weight; and antioxidant levels in the blood and stomach tissues. Results showed that 17/20 (85%) gastroesophageal tissues from carcinogen MNNG-treated rats developed dysplasia and cancer, as compared to 8/20 (40%) rats treated with MNNG plus MRN-100. In addition, MRN-100 exerted an antioxidant effect in both the blood and stomach tissues by increasing levels of GSH, antioxidant enzymes SOD, CAT, and GPx, and total antioxidant capacity (TAC) level. This was accompanied by a reduction in the total free-radical and malondialdehyde levels. Furthermore, MRN-100 protected against body and organ weight loss. Thus, MRN-100 exhibited significant cancer chemopreventive activity by protecting tissues against oxidative damage in rats, which may suggest its effectiveness as an adjuvant for the treatment of gastric/esophageal carcinoma.