Quantum chemical study in the direction to design efficient donor-bridge-acceptor triphenylamine sensitizers with improved electron injection

The ground state geometries have been computed by using density functional theory. The excitation energies for dye sensitizers were performed by using time dependant density functional theory. The polarizable continuum model (PCM) has been used for evaluating bulk solvent effects at all stages. The calculations have been carried out in methanol according to the experimental set up. The long-range-corrected functional (PCM-TD-LC-BLYP) underestimate the absorption spectrum of parent molecule while PCM-TDBHandHLYP is in good agreement with the experimental data. The highest occupied molecular orbital (HOMO) is delocalized on TPA moiety while lowest unoccupied molecular orbital (LUMO) is localized on anchoring group, conjugated chain and the benzene ring near to the anchoring group. The LUMO energies of all the investigated dyes are above the conduction band of TiO(2), HOMOs are below the redox couple and HOMO-LUMO energy gaps of studied dyes are smaller compared to TC4. The 1 and 3 are 7 and 12?nm blue shifted while 2 and 4 are 25 and 22?nm red shifted, respectively compared to TC4. The trend of electron injection (ΔG(inject)), relative electron injection (ΔG (r) (inject) ()), and electronic coupling constant (|VRP|) has been observed as 3?>?1?>?4?>?2?>?TC4. The improved ΔG(inject), |VRP| and light harvesting efficiency (LHE) of new designed sensitizers revealed that these materials would be excellent sensitizers. The broken coplanarity between the benzene near anchoring group having LUMO and the last benzene attached to TPA unit in 1-4 consequently would hamper the recombination reaction.     

Expression and identification of folate-sensitive fragile sites in British Suffolk sheep (<Emphasis Type="Italic">Ovis aries</Emphasis>)

An investigation to understand the dynamics and biological significance of fragile site expression, and identification of 5-fluorodeoxyuridine (FUdR) induced chromosomal gaps/breaks, were carried out in an experimental flock of 45 Suffolk sheep. The statistical comparison revealed, highly significant variation in the frequency of chromosomal fragile site expression between control and FUdR cultures. Mean (± S.D.) values for cells with gaps and breaks, or aberrant cell count (AC), and the number of aberrations (NoA) per animal were 2.02 ± 0.34, 2.42 ± 0.48, 13.26 ± 0.85 and 21.87 ± 1.88 (P < 0.01) in control and FUdR cultures, respectively. The comparison of age revealed nonsignificant variation between control and FUdR cultures. The G-band analysis of fragile site data revealed gaps in 29 autosomal and two X-chromosomal bands in the control cultures, whereas FUdR treated cultures scored 78 unstable bands in autosomes of which 56 were significantly fragile. X-chromosomes expressed breaks and gaps in six G-negative bands and five of them (Xq13, Xq15, Xq17, Xq24 and Xq26) were significantly fragile. The distribution comparison of autosomal fragile sites between sex groups did not reveal any significant variation. Female X-chromosomes were significantly more fragile than the male X-chromosomes. The distribution comparison for age groups (lambs versus adults) revealed significantly higher number of fragile bands in adults. Comparison of published data on reciprocal translocations in sheep with the fragile-site data obtained in this study indicated that the break sites of both phenomena were correlated. Similarities were also found between fragile sites and breakpoints of evolutionary significance in family Bovidae.     

Infection of myeloid dendritic cells with Listeria monocytogenes leads to the suppression of T cell function by multiple inhibitory mechanisms

Myeloid dendritic cells (DC) and macrophages play an important role in pathogen sensing and antimicrobial defense. In this study we provide evidence that myeloid DC respond to infection with Listeria monocytogenes with simultaneous induction of multiple stimulatory and inhibitory molecules. However, the overall impact of infected DC during T cell encounter results in suppression of T cell activation, indicating that inhibitory pathways functionally predominate. Inhibitory activity of infected DC is effected mainly by IL-10 and cyclooxygenase 2-mediated mechanisms, with soluble CD25 acting as an IL-2 scavenger as well as by the products of tryptophan catabolism. These inhibitory pathways are strictly TNF-dependent. In addition to direct infection, DC bearing this regulatory phenotype can be induced in vitro by a combination of signals including TNF, TLR2, and prostaglandin receptor ligation and by supernatants derived from the infected cells. Both infection-associated DC and other in vitro-induced regulatory DC are characterized by increased resistance to infection and enhanced bactericidal activity. Furthermore, myeloid DC expressing multiple regulatory molecules are identified in vivo in granuloma during listeriosis and tuberculosis. Based on the in vivo findings and the study of in vitro models, we propose that in granulomatous infections regulatory DC may possess dual function evolved to protect the host from disseminating infection via inhibition of granuloma destruction by T cells and control of pathogen spreading.     

Prolonging the interval from ovarian hyperstimulation to laparoscopic ovum pick-up improves oocyte yield, quality, and developmental competence in goats

The objective was to evaluate the effect of the interval between ovarian hyperstimulation and laparoscopic ovum pick-up (LOPU) on quality and developmental competence of goat oocytes before and after in vitro maturation (IVM) and intracytoplasmic sperm injection (ICSI). Estrus was synchronized with an intravaginal insert containing 0.3g progesterone (CIDR) for 10d, combined with a luteolytic treatment of 125 microg cloprostenol 36 h prior to CIDR removal. Ovaries were hyperstimulated with 70 mg FSH and 500 IU hCG given im 36, 60, or 72 h prior to LOPU (n=15, 16, and 7 does, respectively). For these groups, oocyte retrieval rates (mean+/-S.E.M.) were 24.7+/-2.9, 54.5+/-4.7, and 82.8+/-4.6% (P<0.001), and the proportions of cumulus-oocyte complexes (COC) with more than five layers of cumulus cells were 29.7+/-8.3, 37.6+/-6.9, and 37.3+/-7.0% (P<0.001). The proportion of IVM oocytes was highest at 72 h (82.1+/-2.8%; P<0.05), with no significant difference between 36 and 60 h (57.3+/-8.9% and 69.0+/-8.4%). Cleavage rates of ICSI embryos were 4.2+/-4.2, 70.9+/-8.4, and 78.9+/-8.2% with LOPU 36, 60, and 72 h post FSH/hCG (P<0.01), with a lower proportion of Grade-A embryos (P<0.05) following LOPU at 36 h compared to 60 and 72 h (29.7+/-8.3%, 37.6+/-6.9%, and 37.3+/-7.0%). In summary, a prolonged interval from FSH/hCG to LOPU improved oocyte retrieval rate and oocyte quality. Therefore, under the present conditions, LOPU 60 or 72 h after FSH/hCG optimized yields of good-quality oocytes for IVM and embryo production in goats.     

Increased Oxidant Stress and Decreased Antioxidant Status in Erythrocytes of Rats Fed with Zinc-deficient Diet

The aim of this study was to evaluate the lipid peroxidation, nitric oxide (NO), and free radical scavenging enzyme activities in erythrocytes of zinc (Zn)-deficient rats and to investigate the relationship among these parameters in either group. Sixteen male rats with a weight of 40-50 g were used for the experiment. The rats were divided into control (n = 8) and Zn-deficient groups. At the end of the experiment, the animals were anesthetized with ketamine-HCl (Ketalar, 20 mg/kg(-1), i.p.), and the blood was collected by cardiac puncture after thoracotomy. Blood samples were collected in vacutainer tubes without and with K(3)-EDTA as anticoagulant. Erythrocyte catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GRD), glutathione-S-transferase (GST), superoxide dismutase (SOD) activities, total (enzymatic plus nonenzymatic) superoxide scavenger activity (TSSA), nonenzymatic superoxide scavenger activity (NSSA), antioxidant potential (AOP), and serum zinc (Zn) values in the Zn-deficient group were significantly lower than those of the control group, whereas NO and malondialdehyde (MDA) levels were significantly higher than those of the control group. The results show that Zn deficiency causes a decrease in antioxidant defense system and an increase in oxidative stress in erythrocyte of rats.     

Effects of pinealectomy and exogenous melatonin on ghrelin and peptide YY in gastrointestinal system and neuropeptide Y in hypothalamic arcuate nucleus: immunohistochemical studies in male rats

It is reported that the pineal gland and its main hormone melatonin may have a role in the regulation of ghrelin synthesis in the brain. Stomach is the place where ghrelin is predominantly expressed and secreted. One aim of this study was to investigate possible effects of pinealectomy and melatonin treatment on gastric ghrelin amount. The studies on the effects of the pineal gland on leptin and ghrelin arises the question whether the pineal gland has also effects on the other energy-regulatory peptides such as peptide YY (PYY) and neuropeptide Y (NPY). Therefore, we also aimed to investigate the changes in the immunohistochemical staining of intestinal PYY and hypothalamic NPY following pinealectomy and melatonin treatment. Serum PYY levels were also investigated. Sprague-Dawley rats were divided into four groups as sham-operated (SHAM), sham-operated with melatonin treatment (SHAM-MT), pinealectomised (PNX) and melatonin-treated PNX (PNX-MT) groups. The cells immunostained for ghrelin were abundant throughout the gastric mucosa in all the groups. Neither pinealectomy nor exogenous melatonin affected significantly immunohistochemical staining of ghrelin in stomach. Pinealectomy resulted in a significant increase in immunohistochemical staining of PYY in ileum. The results of serum PYY measurement corresponded closely to the data obtained by immunohistochemical analysis of PYY in ileum, being significantly lower and higher in SHAM and PNX groups, respectively. Pinealectomy caused a decrease in NPY synthesis in ARC as understood from low immunohistochemical staining of NPY. Melatonin treatment increased NPY synthesis in SHAM rats and restored reduction in NPY synthesis caused by pinealectomy. In conclusion, the pineal gland and its main hormone melatonin can be suggested to have a role in the regulation of NPY synthesis in ARC and PYY in gastrointestinal system.     

Fungal root endophytes from natural vegetation in Mediterranean environments with special reference to Fusarium spp

Surveys (in 2002 and 2003) were performed for fungal endophytes in roots of 24 plant species growing at 12 sites (coastal and inland soils, both sandy soils and salt marshes) under either water or salt stress in the Alicante province (Southeast Spain). All plant species examined were colonized by endophytic fungi. A total of 1830 fungal isolates were obtained and identified by morphological and molecular [internal transcribed spacer (ITS) and translation elongation factor-1alpha gene region (TEF-1alpha) sequencing] techniques. One hundred and forty-two fungal species were identified, belonging to 57 genera. Sterile mycelia were assigned to 177 morphospecies. Fusarium and Phoma species were the most frequent genera, followed by Aspergillus, Alternaria and Acremonium. Fungal root endophytic communities were influenced by the soil type where their respective host plants grew, but not by location (coastal or inland sites). Fusarium oxysporum, Aspergillus fumigatus and Alternaria chlamydospora contributed most to the differences found between endophytic communities from sandy and saline soils. Host preference was found for three Fusarium species studied. Fusarium oxysporum and Fusarium solani were especially isolated from plants of the family Leguminosae, while Fusarium equiseti showed a preference for Lygeum spartum (Gramineae). In some cases, specificity could be related to intra-specific variability as shown by sequencing of the TEF-1alpha in the genus Fusarium.     

Morphological and Inter Simple Sequence Repeat (ISSR) Markers Analyses of Corynespora cassiicola Isolates from Rubber Plantations in Malaysia

Morphological features and Inter Simple Sequence Repeat (ISSR) polymorphism were employed to analyse 21 Corynespora cassiicola isolates obtained from a number of Hevea clones grown in rubber plantations in Malaysia. The C. cassiicola isolates used in this study were collected from several states in Malaysia from 1998 to 2005. The morphology of the isolates was characteristic of that previously described for C. cassiicola. Variations in colony and conidial morphology were observed not only among isolates but also within a single isolate with no inclination to either clonal or geographical origin of the isolates. ISSR analysis delineated the isolates into two distinct clusters. The dendrogram created from UPGMA analysis based on Nei and Li's coefficient (calculated from the binary matrix data of 106 amplified DNA bands generated from 8 ISSR primers) showed that cluster 1 encompasses 12 isolates from the states of Johor and Selangor (this cluster was further split into 2 sub clusters (1A, 1B), sub cluster 1B consists of a unique isolate, CKT05D); while cluster 2 comprises of 9 isolates that were obtained from the other states. Detached leaf assay performed on selected Hevea clones showed that the pathogenicity of representative isolates from cluster 1 (with the exception of CKT05D) resembled that of race 1; and isolates in cluster 2 showed pathogenicity similar to race 2 of the fungus that was previously identified in Malaysia. The isolate CKT05D from sub cluster 1B showed pathogenicity dissimilar to either race 1 or race 2.     

Staphylococcal cassette chromosome mec (SCCmec) characterization and panton-valentine leukocidin gene occurrence for methicillin-resistant Staphylococcus aureus in Turkey, from 2003 to 2006

Methicillin-resistant Staphylococcus aureus (MRSA) cause serious community-acquired and nosocomial diseases all over the world. We determined the SCCmec types and occurrence of the PVL gene by using TaqMan real-time PCR method, and correlated these with phenotypic antibiotic susceptibility patterns for MRSA strains collected from Gulhane Military Medical Academy Hospital (GMMAH) during 4 years study period. To our knowledge, this is the first report from Turkey of molecular SCCmec typing analysis of MRSA stains. A total of 385 clinical MRSA isolates collected in the clinical and Microbiology Laboratory at GMMAH between 2003 and 2006 were included in the study. Overall, SCCmec types-I, II, III, IV, V, nontypeable and PVL occurrence were detected in 11 (2.8%), 3 (0.8%), 316 (82.1%), 20 (5.1%), 20 (5.1%), 15 (3.9%) and 5 (1.3%) isolates, respectively. A total of 330 (85.5%) were SCCmec-I/II/III and 40 (10.3%) were SCCmec IV/V. SCCmec-I/II/III isolates were recovered more from patients with serious infections in surgical departments especially those with intensive care units than the SCCmec-IV/V isolates (χ² = 13.560, P < 0.001). SCCmec-I/II/III MRSA strains were predominantly recovered from blood stream (53.0%, P = 0.014), while SCCmec-IV/V strains were predominately isolated from skin and soft tissue and abscess (55.0%, P < 0.001). The PVL gene was detected in 10.0% of SCCmec-IV/V isolates in contrast to 0.3% in SCCmec-I/II/III (χ² = 25.164, P < 0.001). SCCmec-I/II/III MRSA strains were more resistant to clindamycin (χ² = 5.078, P = 0.024), amoxicillin-clavulanate (χ² = 84.912, P < 0.001), erythromycin (χ² = 4.651, P = 0.031), gentamicin (χ² = 24.869, P < 0.001), and rifampin (χ² = 18.878, P < 0.001) than SCCmec-IV/V MRSA strains. This data indicates that SCCmec-III MRSA strains that do not carry the PVL gene are the predominant MRSA strains in our hospital setting in Ankara, capital of Turkey and that SCCmec-I/II/III MRSA strains may cause serious infections in surgical departments especially those with intensive care units.     

Anopheles gambiae cadherin AgCad1 binds the Cry4Ba toxin of Bacillus thuringiensis israelensis and a fragment of AgCad1 synergizes toxicity

A midgut cadherin AgCad1 cDNA was cloned from Anopheles gambiae larvae and analyzed for its possible role as a receptor for the Cry4Ba toxin of Bacillus thuringiensis strain israelensis. The AgCad1 cadherin encodes a putative 1735-residue protein organized into an extracellular region of 11 cadherin repeats (CR) and a membrane-proximal extracellular domain (MPED). AgCad1 mRNA was detected in midgut of larvae by polymerase chain reaction (PCR). The AgCad1 protein was localized, by immunochemistry of sectioned larvae, predominately to the microvilli in posterior midgut. The localization of Cry4Ba binding was determined by the same technique, and toxin bound microvilli in posterior midgut. The AgCad1 protein was present in brush border membrane fractions prepared from larvae, and Cry4Ba toxin bound the same-sized protein on blots of those fractions. The AgCad1 protein was expressed transiently in Drosophila melanogaster Schneider 2 (S2) cells. 125I-Cry4Ba toxin bound AgCad1 from S2 cells in a competitive manner. Cry4Ba bound to beads extracted 200 kDa AgCad1 and a 29 kDa fragment of AgCad1 from S2 cells. A peptide containing the AgCad1 region proximal to the cell (CR11-MPED) was expressed in Escherichia coli. Although Cry4Ba showed limited binding to CR11-MPED, the peptide synergized the toxicity of Cry4Ba to larvae. AgCad1 in the larval brush border is a binding protein for Cry4Ba toxin. On the basis of binding results and CR11-MPED synergism of Cry4Ba toxicity, AgCad1 is probably a Cry4Ba receptor.