<Emphasis Type="Italic">Huffmanela lata</Emphasis> n. sp. (Nematoda: Trichosomoididae: Huffmanelinae) from the shark <Emphasis Type="Italic">Carcharhinus amblyrhynchos</Emphasis> (Elasmobranchii: Carcharhinidae) off New Caledonia

Huffmanela lata n. sp. is described from eggs only, which were found in a small black spot on the skin near the gill opening of a shark, Carcharhinus amblyrhynchos, caught off Nouméa, New Caledonia, South-West Pacific. The eggs are 77–88 (mean 84) μm in length and 52–63 (mean 57) μm in width, with a thick (6–8 μm) shell, apparently spinose. Mobile larvae, 200–250 μm in length, were visible in the eggs. The species is distinguished from other members of the genus by the dimensions and shape of its eggs, which are the broadest ever reported. This is the second species of Huffmanela described from a shark, after H. carcharhini (MacCallum, 1925), to which it appears closely related in terms of its site in the skin and the nature of the egg surface.     

A strategy to profile prime and non-prime proteolytic substrate specificity

A strategy was developed to determine the prime and non-prime substrate specificity of serine, threonine and cysteine proteases. ACC positional scanning technology was employed to determine the P4-P1 non-prime site substrate specificity. The data was used to synthesize biased donor-quencher positional scanning libraries to profile the P1'-P4' prime site substrate specificity. Directed sorting using the Irori Nanokan system allowed for the archiving of multiple P1'-P4' positional scanning libraries. From these libraries focused donor-quencher libraries incorporating P4-P1 data for each protease under study could be rapidly prepared. The profiling of thrombin and caspase-3 P4-P4' substrate specificity, comparison of the library specificity data to single substrates, and the analysis of physiological cleavage sites are described.     

Suppression of generalized seizures activity by intrathalamic 2-chloroadenosine application

In the present study, we investigated the effects of micro-injecting 2-chloroadenosine (2-CADO; an adenosine receptor agonist) into the thalamus alone and with theophylline (a nonspecific adenosine receptor antagonist) pretreatment on pentylenetetrazol (PTZ)-induced tonic-clonic seizures in male Wistar albino rats. Following intrathalamic 2-CADO injection alone or theophylline pretreatment, 50 mg kg(-1) PTZ was given ip after 1 and 24 hrs. The duration of epileptic seizure activity was recorded by cortical electroencephalogram (EEG), and seizure severity was behaviorally scored. Intrathalamic 2-CADO administration induced significant decreases in both seizure duration and seizure severity scores at 1 and 24 hrs, but the effects were more abundant on the seizures induced after 24 hrs. On the other hand, pretreatment with theophylline prevented the inhibitor effect of 2-CADO on seizure activity and increased both seizure duration and seizure scores. Present results suggest that the activation of adenosine receptors in the thalamus may represent another anticonvulsant/modulatory site of adenosine action during the course of the PTZ-induced generalized tonic-clonic seizures and provide additional data for the involvement of the adenosinergic system in the generalized seizures model.     

Type II Fatty Acid Biosynthesis, a New Approach in Antimalarial Natural Product Discovery

Malaria, one of the most problematic infectious diseases worldwide, is on the rise. The absence of an effective vaccine and the spread of drug-resistant strains of Plasmodium clearly indicate the necessity for the development of new chemotherapeutic agents and the identification of novel targets. The recent discovery of a relict, non-photosynthetic plastid-like organelle, the so-called apicoplast, in Plasmodium has opened up new avenues in malaria research. It also initiated the Plasmodium falciparum genome sequencing project, which revealed a number of biochemical pathways previously unknown to Plasmodium, i.e. cytosolic shikimate pathway, apicoplastic type II fatty acid, non-mevalonate isoprene and haem biosyntheses. Since these vital biosynthetic processes are absent in humans or fundamentally different from those found in humans, they represent excellent targets for pharmaceutical interventions. We are interested in the type II fatty acid synthase (FAS II) system of malaria parasite and focus on the FabI enzyme, the only known enoyl-ACP reductase in Plasmodium involved in the final reduction step of the fatty acid chain elongation cycle. Here we describe the general aspects of fatty acid biosynthesis, its essentiality to the malaria parasite and our continuing efforts to discover in Turkish medicinal plants natural antimalarial agents, which specifically target the plasmodial FabI enzyme.Phytochemical Society of Europe (PSE)-Pierre Fabre Prize 2004 Lecture     

Molecular epidemiology of penicillin resistantStreptococcus pneumoniae strains in Turkey. A multicenter study

A total of 539 isolates recovered from various clinical sites were collected from 13 hospitals from different regions of Turkey between 1999 and 2002. Susceptibility to penicillin and cefotaxime was determined by the E-test and the remaining antimicrobials were evaluated by disk diffusion tests. Penicillin resistant and intermediate isolates were serotyped and PFGE patterns were analysed. Overall 16 isolates (3%) were resistant to penicillin, and 143 (26.5%) were intermediate. Resistance and intermediate rates were 3.1% and 29.0% respectively in respiratory tract isolates. Multiple resistance (resistance to ≥3 antibiotics) occurred in 81.8% of the penicillin resistant isolates and the most frequent resistance phenotype was penicillin+trimethoprim/sulphamethoxazole (37.7%). Minimum inhibitory concentrations of cefotaxime were lower than 1 mg/ml for all the isolates. The highest rate of resistance was observed for trimethoprim/ sulphamethoxazole (26.6%) followed by doxycycline (12.6%). Resistance to erythromycin was 10.1%, clindamycin 9.9%, chloramphenicol 4.3%, ofloxacin 5.0% and levofloxacin 0.2%. There was no resistance to vancomycin. Resistant isolates belonged to serogroups 9, 23, and 6. The most frequent serogroups among intermediate isolates were 23, 19, 14, 1, 9, and 6. Five distinct PFGE patterns were observed among penicillin resistant isolates. There was no distinct clustering of specific PFGE patterns in the study centres. No correlation between serotypes, resistance and PFGE patterns was found. There seems to be genetic heterogeneity inStreptococccus pneumoniae isolates in Turkey.     

From gene expression analysis to tissue microarrays: a rational approach to identify therapeutic and diagnostic targets in lymphoid malignancies

Mantle cell lymphoma (MCL) is an aggressive lymphoid malignancy for which better treatment strategies are needed. To identify potential diagnostic and therapeutic targets, a signature consisting of MCL-associated genes was selected based on a comprehensive gene expression analysis of malignant and normal B cells. The corresponding protein epitope signature tags were identified and used to raise monospecific, polyclonal antibodies, which were subsequently analyzed on paraffin-embedded sections of malignant and normal tissue. In this study, we demonstrate that the initial selection strategy of MCL-associated genes successfully allows identification of protein antigens either uniquely expressed or overexpressed in MCL compared with normal lymphoid tissues. We propose that genome-based, affinity proteomics, using protein epitope signature tag-induced antibodies, is an efficient way to rapidly identify a number of disease-associated protein candidates of both previously known and unknown identities.     

Genetic relationships among NE Turkish Lilium L. (Liliaceae) species based on a random amplified polymorphic DNA analysis

Random amplified polymorphic DNA (RAPD) fingerprinting was used to study species boundaries in six closely related NE Turkish Lilium (Liliaceae) taxa of the section Liriotypus. The investigated taxa were L. ciliatum, L. akkusianum, L. ponticum, L. kesselringianum, L. armenum, and L. szovitsianum. Of the 108 primers screened, 11 provided polymorphic and reproducible bands. A total of 93 polymorphic bands were scored for 122 individuals from 18 populations of the six Lilium taxa and principle coordinate analysis and neighbour-joining cluster analysis based on these RAPD profiles were performed. The results demonstrate a clear distinction between the two species L. ciliatum and L. akkusianum, and the other four species. While populations of the two species groups are found to be allopatrically distributed, the two species groups overlap in their geographical ranges. Analysis of molecular variance (AMOVA) indicated that nearly half of the total molecular variance is found within the individual populations and that the molecular variance among species is as high as the variance within the individual species, indicating that genetic differentiation of the species is rather weak.     

The Lbc Rho Guanine Nucleotide Exchange Factor/α-Catulin Axis Functions in Serotonin-induced Vascular Smooth Muscle Cell Mitogenesis and RhoA/ROCK Activation

Serotonin (5-hydroxytryptamine, 5-HT) is mitogenic for several cell types including pulmonary arterial smooth muscle cells (PASMC), and is associated with the abnormal vascular smooth muscle remodeling that occurs in pulmonary arterial hypertension. RhoA/Rho kinase (ROCK) function is required for 5-HT-induced PASMC mitogenesis, and 5-HT activates RhoA; however, the signaling steps are poorly defined. Rho guanine nucleotide exchange factors (Rho GEFs) transduce extracellular signals to Rho, and we found that 5-HT treatment of PASMC led to increased membrane-associated Lbc Rho GEF, suggesting modulation by 5-HT. Lbc knockdown by siRNA attenuated 5-HT-induced thymidine uptake in PASMC, indicating a role in PASMC mitogenesis. 5-HT triggered Rho-dependent serum response factor-mediated reporter activation in PASMC, and this was reduced by Lbc depletion. Lbc knockdown reduced 5-HT-induced RhoA/ROCK activation, but not p42/44 ERK MAP kinase activation, suggesting that Lbc is an intermediary between 5-HT and RhoA/ROCK, but not ERK. 5-HT stimulation of PASMC led to increased association between Lbc, RhoA, and the α-catulin scaffold. Furthermore, α-catulin knockdown attenuated 5-HT-induced PASMC thymidine uptake. 5-HT-induced PASMC mitogenesis was reduced by dominant-negative G_q protein, suggesting cooperation with Lbc/α-catulin. These results for the first time define a Rho GEF involved in vascular smooth muscle cell growth and serotonin signaling, and suggest that Lbc Rho GEF family members play distinct roles. Thus, the Lbc/α-catulin axis participates in 5-HT-induced PASMC mitogenesis and RhoA/ROCK signaling, and may be an interventional target in diseases involving vascular smooth muscle remodeling.     

The effect of cysteine and glutathione on sperm and oxidative stress parameters of post-thawed bull semen

The aim of this study was to determine the effects of antioxidants such as reduced glutathione (GSH) and cysteine in Laiciphose® extender on semen parameters, fertilizing ability, lipid peroxidation (LPO) level and glutathione peroxidise (GPx) activity of post-thawed bull semen. Totally 54 ejaculates of three bulls were used in the study. Five groups, namely; GSH (0.5 and 2 mM), cysteine (5 and 10 mM) and control group, were conducted to test the antioxidants in Laiciphose®. Insemination doses were processed that each 0.25-mL straw contained 15 × 10⁶ sperm. The addition of antioxidants did not present any significant effect on the percentages of post-thaw sperm morphology (acrosome and total abnormalities), subjective, CASA and progressive motilities, as well as sperm motility characteristics (VAP, VSL, VCL, LIN and ALH), compared to the control groups (P > 0.05). GSH 0.5 mM (55.5 ± 7.38%) and cysteine 10 mM (48 ± 5.65%) led to lower rates of DNA damage, compared to control (P < 0.05). As regards to MDA level, cysteine at 10 mM dose gave the highest level (4.99 ± 0.44 nmol/L) (P < 0.001). GPx activity was demonstrated to be higher level upon the addition of 5 mM cysteine when compared to the other groups (P < 0.05). With respect to fertility results based on 60-day non-returns, the supplementation of antioxidants did not present significant differences (P > 0.05). The results of this study may provide an useful information for the future studies in this area. So, further studies could be suggested to achieve better information in terms of the DNA damage and fertilizing capacity of bull sperm frozen with effective antioxidants.