Ultrastructure of spermiogenesis and mature spermatozoon of Skrjabinoporus merops (Cyclophyllidea, Metadilepididae)

The ultrastructure of the mature spermatozoon and the spermiogenesis of a cestode belonging to the family Metadilepididae is described for the first time. The mature spermatozoon of Skrjabinoporus merops is characterized by twisted peripheral microtubules, the presence of a single crested body, periaxonemal sheath and electron-dense rods, and the absence of intracytoplasmic walls and inclusions (glycogen or proteinaceous granules); no peripheral microtubules where nucleus contacts the external plasma membrane. Four morphologically distinct regions of the mature spermatozoon are differentiated. The proximal part (Region I) contains a single crested body, periaxonemal sheath is absent in some (proximal) sections and is present in others situated closer to the nucleus. The central Region II is nucleated, and is followed by Region III that contains a periaxonemal sheath. The distal pole, Region IV, is characterized by disintegration of the axoneme. Spermiogenesis follows the type III pattern (Ba and Marchand 1995) although in S. merops a slight flagellar rotation is observed. The differentiation zone is characterized by the absence of striated roots and intercentriolar body; two centrioles are present, one of which gives rise to a free flagellum. The latter rotates and undergoes proximodistal fusion with the cytoplasmic protrusion of the differentiation zone. Spermiological characters of S. merops are similar to those of the families Taeniidae and Catenotaeniidae. The mature spermatozoon differs from those of the Dilepididae (where the metadilepidid species have previously been classified) by the lack of glycogen.     

Measures of anxiety, retention and stress in the rat following treatment with the diterpene sclareol glycol

In a punished drinking test in rats sclareol glycol (SG) decreased the number of punished responses ("proconflict response") while diazepam had the opposite effect; SG antagonized the "anticonflict response" of diazepam. Post-training administration of SG in rats enhanced retention in active avoidance task evaluated 24 h later. SG produced an increase in plasma ACTH and corticosterone levels in unstressed rats. The stress-induced increase in ACTH and corticosterone secretion was potentiated by SG. All these data suggest that SG behaves as an anxiogenic, memory-facilitator and perhaps adaptogenic agent. The effects of SG may be mediated by different mechanisms of action (stimulation of adenylate cyclase, interaction with GABA-ergic and dopaminergic transmitter mechanisms).     

In vivo metabolism of nociceptin/orphanin FQ in rat hippocampus

The in vivo metabolism of the newly identified endogenous ligand for the ORL1 receptor, the opioid-like peptide nociceptin (orphanin FQ) in rat hippocampus was studied using size-exclusion chromatography linked to electrospray ionization mass spectrometry. The results show that nociceptin is metabolized step-wise in vivo into fragments (1-13) and (14-17) as well as (1-9) and (10-13), respectively. Interestingly, the (1-13) and (1-9) fragments have the same C-terminus, Arg-Ala-Lys, suggesting that this is a motif recognized by an enzyme which fragments the peptide in two consecutive steps. Injection of the (1-13) fragment into rat hippocampus had no effect on spatial learning or motor function under conditions where nociceptin is active, showing that this metabolic conversion reduces affinity for the ORL-1-receptor.     

The Intracellular Environment of Human Macrophages That Produce Nitric Oxide Promotes Growth of Mycobacteria

Nitric oxide (NO) is a diffusible radical gas produced from the activity of nitric oxide synthase (NOS). NOS activity in murine macrophages has a protective role against mycobacteria through generation of reactive nitrogen intermediates (RNIs). However, the production of NO by human macrophages has remained unclear due to the lack of sensitive reagents to detect NO directly. The purpose of this study was to investigate NO production and the consequence to mycobacteria in primary human macrophages. We found that Mycobacterium bovis BCG or Mycobacterium tuberculosis infection of human macrophages induced expression of NOS2 and NOS3 that resulted in detectable production of NO. Treatment with gamma interferon (IFN-γ), l-arginine, and tetrahydrobiopterin enhanced expression of NOS2 and NOS3 isoforms, as well as NO production. Both of these enzymes were shown to contribute to NO production. The maximal level of NO produced by human macrophages was not bactericidal or bacteriostatic to M. tuberculosis or BCG. The number of viable mycobacteria was increased in macrophages that produced NO, and this requires expression of nitrate reductase. An narG mutant of M. tuberculosis persisted but was unable to grow in human macrophages. Taken together, these data (i) enhance our understanding of primary human macrophage potential to produce NO, (ii) demonstrate that the level of RNIs produced in response to IFN-γ in vitro is not sufficient to limit intracellular mycobacterial growth, and (iii) suggest that mycobacteria may use RNIs to enhance their survival in human macrophages.     

Subtraction procedure for powerline interference removing from ECG: improvement for non-multiple sampling

This paper presents an improvement of the subtraction procedure for interference cancellation in ECG. In contrast to the well-known hardware and software filters, the procedure does not affect the signal frequency components around the rated powerline frequency. Originally, the procedure was developed for multiplicity between the sampling rate and the interference frequency. We analysed and improved the procedure structure in cases of non-multiple sampling, introducing a set of specially designed filters. Thus the implementation of the subtraction procedure is extended to almost all possible cases of sampling rate and interference frequency variation. The procedure has been adapted for online implementation. The research was initially carried out in a MATLAB environment. Further, programmes have been written in C^?+?+ language for digital signal processors and personal computers. The results obtained with real ECG signals show high efficiency of the interference cancellation.     

Analysis of exome sequence in 604 trios for recessive genotypes in schizophrenia

Genetic associations involving both rare and common alleles have been reported for schizophrenia but there have been no systematic scans for rare recessive genotypes using fully phased trio data. Here, we use exome sequencing in 604 schizophrenia proband–parent trios to investigate the role of recessive (homozygous or compound heterozygous) nonsynonymous genotypes in the disorder. The burden of recessive genotypes was not significantly increased in probands at either a genome-wide level or in any individual gene after adjustment for multiple testing. At a system level, probands had an excess of nonsynonymous compound heterozygous genotypes (minor allele frequency, MAF ⩽1%) in voltage-gated sodium channels (VGSCs; eight in probands and none in parents, P=1.5 × 10⁻⁴). Previous findings of multiple de novo loss-of-function mutations in this gene family, particularly SCN2A, in autism and intellectual disability provide biological and genetic plausibility for this finding. Pointing further to the involvement of VGSCs in schizophrenia, we found that these genes were enriched for nonsynonymous mutations (MAF ⩽0.1%) in cases genotyped using an exome array, (5585 schizophrenia cases and 8103 controls), and that in the trios data, synaptic proteins interacting with VGSCs were also enriched for both compound heterozygosity (P=0.018) and de novo mutations (P=0.04). However, we were unable to replicate the specific association with compound heterozygosity at VGSCs in an independent sample of Taiwanese schizophrenia trios (N=614). We conclude that recessive genotypes do not appear to make a substantial contribution to schizophrenia at a genome-wide level. Although multiple lines of evidence, including several from this study, suggest that rare mutations in VGSCs contribute to the disorder, in the absence of replication of the original findings regarding compound heterozygosity, this conclusion requires evaluation in a larger sample of trios.     

CHEK2 gene alterations independently increase the risk of death from breast cancer in Bulgarian patients

Checkpoint kinase 2 (CHEK2) is a?DNA damage-activated protein kinase implicated in cell cycle checkpoint control. The significance of CHEK2 alterations for breast cancer incidence and clinical behavior is not clear. In this study we determined the mutational spectrum and the level of promoter hypermethylation of CHEK2 gene in a?group of 145 Bulgarian patients with breast cancer. A?special emphasis was put on the clinical impact of CHEK2 alterations for breast cancerogenesis.PCR-SSCP-sequencing analysis of the entire coding sequence of CHEK2 gene was performed to estimate the mutational profile of tumor samples. Methylation-sensitive SSCP was applied to determine the methylation status in CpG clusters implicated in CHEK2 silencing. Clinical significance of CHEK2 alterations was evaluated using standard statistical methods.Mutations in CHEK2 were identified in 9.65 % of the patients. Two novel missense substitutions Thr476Met (C >T) and Ala507Gly (C>G), and a?novel silent variant Glu79Glu (A>G) were registered. However, hypermethylation was not found in any of the studied cases. Comparison with clinical characteristics showed that CHEK2 positive women have predominantly lobular type of breast carcinoma (р=0.04) and PR+ status (p=0.092). CHEK2 mutations correlated significantly with ATM+ status (p=0.046). All patients with the Glu79Glu variant were progesterone receptor positive (p=0.004). A?decrease in overall survival (p = 0.6301) and a?threefold increased independent risk of death (HR = 3.295, 95%CI 0.850-12.778, p?= 0.085) in CHEK2+patients was found.Our data indicate the significance of CHEK2 gene alterations in contrast to promoter hypermethylation in breast cancerogenesis. Specificity of CHEK2 mutational profile for the Bulgarian population was found. Though CHEK2 mutational status correlated with more favorable clinical characteristics, including positive progesterone receptor and lobular histological type, it independently increased the risk of death in these patients. Keywords: breast cancer, CHEK2, mutation, hypermethylation, clinico-pathological characteristics, overall survival.     

Nanometers-Thick Ferromagnetic Surface Produced by Laser Cutting of Diamond

In this work, we demonstrate that cutting diamond crystals with a laser (532 nm wavelength, 0.5 mJ energy, 200 ns pulse duration at 15 kHz) produced a ≲20 nm thick surface layer with magnetic order at room temperature. We measured the magnetic moment of five natural and six CVD diamond crystals of different sizes, nitrogen contents and surface orientations with a SQUID magnetometer. A robust ferromagnetic response at 300 K was observed only for crystals that were cut with the laser along the (100) surface orientation. The magnetic signals were much weaker for the (110) and negligible for the (111) orientations. We attribute the magnetic order to the disordered graphite layer produced by the laser at the diamond surface. The ferromagnetic signal vanished after chemical etching or after moderate temperature annealing. The obtained results indicate that laser treatment of diamond may pave the way to create ferromagnetic spots at its surface.