Desmettianosides A and B, bisdesmosidic furostanol saponins with molluscicidal activity from Yucca desmettiana

Bioactivity-guided separation of the aqueous methanolic extract of Yucca desmettiana leaves, which in a preliminary screening exhibited significant molluscicidal activity, led to the isolation and structure elucidation of two new steroidal saponins (1 and 2). The structures of desmettianosides A and B, identified as bisdesmosidic furostanol glycosides with six and five sugar units, respectively, were established by detailed spectroscopic analyses of their NMR and MS data. Compounds 1 and 2 exhibited high molluscicidal activity against Biomphalaria alexandrina snails with LC100 values of 6 and 11 mg/L, respectively.     

The use of phospholipid fatty acids (PL-FA) in the determination of rhizosphere specific microbial communities (RSMC) of two wheat cultivars

To determine differences in microbial community structure, phospholipid fatty acids (PL-FA) from rhizosphere bacteria of two different wheat cultivars Triticum aestivum L. (cv. Bohouth-6 and cv. Salamouni) were extracted and analyzed by gas chromatography. This approach was used to overcome the methodological underestimation of microbial densities obtained with isolation, culture techniques and microscopic observations. Our objective was to verify differences in PL-FA profiles from two wheat cultivars grown under controlled environmental conditions. Principal component analysis (PCA) and cluster analysis were used to detect dissimilarities between rhizosphere microbial communities of the two wheat cultivars and signature fatty acids (FA) were used to determine specific differences in the community structures. PCA of the two cultivars explained 79.18% of the variance on principal component 1 (PC1), which accounted for Bohouth-6 rhizosphere soil. The rhizosphere soil of Salamouni accounted for 11.66% of the variance on principal component 2 (PC2). The results demonstrated repeatedly the clustering of the samples into two distinct groups; each group belonging specifically to one of the two wheat cultivars. Profiles of Bohouth-6 showed higher amounts of cyclopropane acid 19:0cy and Sif 7 (Sum in feature 7) than Salamouni. Those FA are known as signature molecules for Gram-negative bacteria. This was also reflected by the higher bacterial counts (cfu g^–1 fresh root weight) of Gram-negative bacteria from the rhizosphere of the former than the latter. The results indicated that under controlled environmental conditions, wheat cultivars of different genotypes exhibit distinct microbial colonization in their rhizosphere.     

IL-8 secreted by tumor associated macrophages contribute to lapatinib resistance in HER2-positive locally advanced breast cancer via activation of Src/STAT3/ERK1/2-mediated EGFR signaling

Locally advanced breast cancer (LABC) is an aggressive disease characterized by late clinical presentation, large tumor size, treatment resistance and low survival rate. Expression of EGFR/HER2 and activation of intracellular tyrosine kinase domains in LABC are associated with poor prognosis. Thus, target therapies such as the anti-receptor tyrosine kinases lapatinib drug have been more developed in the past decade. The response to lapatinib involves the inhibition of RTKs and subsequently signaling molecules such as Src/STAT3/Erk1/2 known also to be activated by the cytokines in the tumor microenvironment (TME). The aim of the present study is to identify the major cytokine that might contribute to lapatinib resistance in EGFR+/HER2+ LABC patients. Indeed, tumor associated macrophages (TAMs) are the main source of cytokines in the TME. Herein, we isolated TAMs from LABC during modified radical mastectomy (MRM). Cytokine profile of TAMs revealed that IL-8 is the most prominent highly secreted cytokine by TAMs of LABC patients. Using in-vitro cell culture model we showed that recombinant IL-8 (50 and 100 ng/mL) at different time intervals interfere with lapatinib action via activation of Src/EGFR and signaling molecules known to be inhibited during treatment. We proposed that to improve LABC patients' response to lapatinib treatment it is preferred to use combined therapy that neutralize or block the action of IL-8.     

Survival ofXanthomonas campestris pv.vesictoria in pepper seeds and roots in symptomless and dry leaves in non-host plants and in the soil

Summary A population ofXanthomonas campestris pv.vesicatoria developed as endophytes in the leaves and rhizosphere of apparently symptomless plants grown under mist but not under dry conditions. The pathogen survired for long periods on, and could be isolated from, the surface of infested dried seeds, inoculated sandy loam soil, dried leaves, and the rhizosphere of pepper and of other non-host plants. In addition, small numbers of the pathogen survived for 18 months in a field previously cropped with pepper diseased with bacterial scab. Healthy nursery or mature plants developed symptoms while growing in soil containing infested leaves, either buried or placed on the soil surface.     

Mutations in exons 6 and 7 of TP53 gene correlate positively with serum tumor necrosis factor alpha independent of microsatellite instability in BAT26 gene in Egyptian patients with endometrial carcinoma

Abnormalities in the TP53 gene are the most frequent genetic alterations in human cancers. The role and mechanism of TP53 mutations have been well studied in many types of human cancer. Similarly, the presence of microsatellite instability (MSI) in the DNA mismatch repair system (hMSH2) may provide evidence of faulty DNA mismatch repair. One of the most important locations of MSI is the BAT26 gene. In addition, deranged serum cytokines, especially elevated levels of the tumor necrosis factor (TNF) alpha, have been found in many gynecological conditions. AIMS: The current study aimed at evaluating mutations in exons 6 and 7 of TP53 and the presence of microsatellite instability in BAT26 of the hMSH2 system in Egyptian patients with endometrial carcinoma. The study also evaluated whether there was a correlation between any of these genetic mutations/instability and the tissue expression of estrogen and progesterone receptors and the serum TNF-alpha level. PATIENTS AND METHODS: The current study included 2 groups: a control group comprising 20 healthy women aged 52.21 +/- 5.80 years attending the clinic for routine checkups and 40 patients with endometrial cancer aged 55.30 +/- 6.21 years. Mutations in TP53 and BAT26 were evaluated using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) and automated sequencing while serum TNF-alpha was measured using an ELISA technique. Estrogen and progesterone receptor expression in biopsy tissue was evaluated using immunohistochemical staining. RESULTS: Seven of the 40 patients (17.5%) were positive for TP53 gene alterations in exon 6, while 9 patients (22.5%) were positive for TP53 alterations in exon 7. Cases positive for TP53 mutations had higher tumor stages. Ten patients (25%) showed MSI in BAT26. Nearly all patients with mutations in BAT26 had a strong family history for endometrial cancer (chi2=13.33, p<0.05). There was no positive correlation between the presence of MSI in the BAT26 gene and mutations in the TP53 gene or high serum TNF-alpha levels. Cases positive for TP53 mutations had a significantly higher level of TNF-alpha than cases negative for TP53 mutations (p<0.05). Cases showing mutations in exon 6 or 7 of TP53 showed a significantly higher intensity of immunohistochemical staining for estrogen and progesterone receptor expression in biopsy tissue than cases negative for mutations. (chi2=8.11, p<0.05). CONCLUSION: Our results suggest that the development of endometrial carcinoma is probably mediated through a multi-step carcinogenesis pathway and mutation of TP53 does not necessarily result from the presence of microsatellite instability in BAT26. The high serum TNF-alpha levels detected in our patients may represent an immunological antitumor response that was particularly evident in cases positive for TP53 mutations.     

Inhibition of mammalian aspartate transcarbamylase by quinazolinone derivatives

Quinazolinone derivatives have been studied as both in vitro and in vivo inhibitors of aspartate transcarbamylase (ATCase). In vitro treatment of mammalian ATCase with four compounds revealed that they inhibited enzyme activity and that 2-phenyl-1,3-4(H)benzothiazin-4-thione was the most potent one. This compound acts as a noncompetitive inhibitor towards both aspartate and carbamoyl phosphate. The values of the inhibition constant (K_i) indicate that this compound exerts a potent inhibitory effect upon ATCase activity. Moreover, in vivo treatment with different doses of these derivatives showed also an inhibitory effect upon ATCase, the relative activity being decreased by 40%–58% with a 1 mg dose. These data support the inhibition of ATCase by quinazolinone derivatives as a new type of inhibitor for the enzyme.     

Protective and Anti-Pathology Effects of Sm Fructose-1,6-Bisphosphate Aldolase-Based DNA Vaccine against Schistosoma mansoni by Changing Route of Injection

This study aimed to evaluate the efficacy of fructose-1,6-bis phosphate aldolase (SMALDO) DNA vaccination against Schistosoma mansoni infection using different routes of injection. The SMALDO has been cloned into the eukaryotic expression vector pcDNA3.1/V5-His TOPO-TA and was used in injecting Swiss albino mice intramuscularly (IM), subcutaneously (SC), or intraperitoneally (IP) (50 µg/mouse). Mice vaccinated with non-recombinant pcDNA3.1 served as controls. Each group was immunized 4 times at weeks 0, 2, 4, and 6. Two weeks after the last booster dose, all mice groups were infected with 80 S. mansoni cercariae via tail immersion. At week 8 post-infection, animals were sacrificed for assessment of parasitological and histopathological parameters. High anti-SMALDO IgG antibody titers were detected in sera of all vaccinated groups (P<0.01) compared to the control group. Both the IP and SC vaccination routes resulted in a significant reduction in worm burden (46.2% and 28.9%, respectively, P<0.01). This was accompanied by a significant reduction in hepatic and intestinal egg counts (41.7% and 40.2%, respectively, P<0.01) in the IP group only. The number of dead eggs was significantly increased in both IP and IM groups (P<0.01). IP vaccination recorded the highest significant reduction in granuloma number and diameter (54.7% and 29.2%, respectively, P<0.01) and significant increase in dead miracidia (P<0.01). In conclusion, changing the injection route of SMALDO DNA vaccination significantly influenced the efficacy of vaccination. SMALDO DNA vaccination via IP route could be a promising protective and anti-pathology vaccine candidate against S. mansoni infection.     

Age-related differences in the morphology of microdamage propagation in trabecular bone

Microdamage density has been shown to increase with age in trabecular bone and is associated with decreased fracture toughness. Numerous studies of crack propagation in cortical bone have been conducted, but data in trabecular bone is lacking. In this study, propagation of severe, linear, and diffuse damage was examined in trabecular bone cores from the femoral head of younger (61.3±3.1 years) and older (75.0±3.9 years) men and women. Using a two-step mechanical testing protocol, damage was first initiated with static uniaxial compression to 0.8% strain then propagated at a normalized stress level of 0.005 to a strain endpoint of 0.8%. Coupling mechanical testing with a dual-fluorescent staining technique, the number and length/area of propagating cracks were quantified. It was found that the number of cycles to the test endpoint was substantially decreased in older compared to younger samples (younger: 77,372±15,984 cycles; older: 34,944±11,964 cycles, p=0.06). This corresponded with a greater number of severely damaged trabeculae expanding in area during the fatigue test in the older group. In the younger group, diffusely damaged trabeculae had a greater damage area, which illustrates an efficient energy dissipation mechanism. These results suggest that age-related differences in fatigue life of human trabecular bone may be due to differences in propagated microdamage morphology.