Predictors of fibrogenesis in children with JIA: a single-center pilot study.

BACKGROUND: Patients with rheumatological diseases are at high risk of developing irreversible fibrotic changes, both articular and extra-articular, as a result of tissue damage caused by the chronic phase of persistent inflammation. Thus, our purpose was to study early markers of fibrosis formation in children with juvenile idiopathic arthritis (JIA). METHODS: Seventy patients with juvenile idiopathic arthritis, namely, polyarthritis (64.29%) and oligoarthritis (35.71%) variant JIA (mean age 13.3 years, 64.29% girls, 35.71% boys), were included in this 4-year prospective study. Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) levels were determined by ELISA kits. RESULTS: We evaluated bFGF (mean: 7478.21 pg/ml; min: 4171.56 pg/ml; max: 18,011.25 pg/ml) and VEGF (mean: 342.47 pg/ml; min: 23.68 pg/ml; max: 2158.91 pg/ml) levels in children with JIA. Children with JIA had a higher VEGF level when JIA onset occurred after 15 years of age and they had a high disease activity; additionally, a higher bFGF level was observed in children older than 14 years and in those with a JIA onset after 15 years of age, the oligoarticular variant, a moderate disease activity and regardless of MTX administration but more often when MTX was administered at a dosage from 10 to 12.5 mg/m2/week. CONCLUSIONS: Laboratory screening of fibrosis formation predictors could help identify patients who may be at greater risk of adverse outcomes. Children with JIA had higher bFGF and VEGF levels when JIA onset occurred after 15 years of age, depending on disease activity.

Mitochondrial peptide Mtln contributes to oxidative metabolism in mice.

Mitoregulin (Mtln) is a recently identified 56 amino acid long mitochondrial peptide conserved in vertebrates. Mtln is known to enhance function of respiratory complex I, which is likely mediated by modulation of lipid composition. To address an influence of Mtln gene on the metabolism we created knockout mice deficient in Mtln gene. In line with accumulation of triglycerides observed earlier on a model of Mtln knockout cell lines, we observed Mtln KO mice to develop obesity on a high fat diet. An increased weight gain could be attributed to enhanced fat accumulation according to the magnetic resonance live imaging. In addition, Mtln KO mice demonstrate elevated serum triglycerides and other oxidation substrates accompanied by an exhaustion of tricarboxylic acids cycle intermediates, suggesting suboptimal oxidation of respiration substrates by mitochondria lacking Mtln.

Treatment of spinal deformity with diastematomyelia type I: one-stage, two-stage surgery and new technique (vertebral column resection through wide bony septum).

STUDY DESIGN: Case series, literature review, and technical note. OBJECTIVES: To compare two different approaches to treat the spinal deformity with split cord malformation type I (SCM I). To present a new method of one-stage surgical treatment of congenital spinal deformity with wide bony septum (SCM I). METHODS: Analysis of the literature on the different types of combined surgical treatment of spinal deformities with SCM I was performed. We have provided our own data on 27 patients treated for congenital spinal deformity and SCM I, one of which underwent Schwab IV type osteotomy at the apex of the deformity through the bony septum and pedicles. Inclusion criteria were presence of spinal deformity in combination with SCM 1, performed surgery to correct spinal deformity, and follow-up period of at least 2 years. RESULTS: The result of the literature review was controversial and requires additional research. The average age of patients was 8.8 ± 6.6 years old. One-stage treatment of SCM I and spinal deformity was performed in 10 patients (group I) and two-stage in 14 patients (group II). Three patients with severe myelodysplasia, SCM I, and congenital kyphoscoliosis underwent correction of spinal deformity without SCM I removing (group III). The group I had the longest surgery duration (mean 289 ± 75 min) and largest blood loss (mean 560 ± 386 ml), a high percentage of deformity correction (mean 69.6%), and the highest rate of complications (60%). The most optimal was the two-stage treatment with the mean surgery duration 191 ± 137 min, mean blood loss 339 ± 436 ml, mean correction rate 63%, and frequency of complications 21%. The average follow-up time was 6.0 ± 2.6 years. CONCLUSIONS: One stage surgery associated with a large surgical invasion and a large number of complications. It can be used in some cases, for example when the wide bony septum (SCM I) is localized at the apex of the congenital scoliosis or kyphosis. In all other cases, it is worth adhering to a two-stage treatment. Many new works demonstrate the relative safety and effectiveness of deformity correction without removing the SCM. In our opinion, indications for treatment of spinal deformity without SCM I removing can be the need to perform a shortening ostetomy outside the SCM zone. The remaining cases require a thorough assessment and a balanced decision.

Results of in vitro test-KRAStissue reagent kit test to determine indications for target therapy of patients diagnosed with colorectal cancer.

As subjects of the clinical trial, 44 samples of paraffin-fixed tissue were used from patients diagnosed with "colorectal cancer." In the course of clinical trials, 44 samples of paraffin-fixed tissue were analyzed in two series of experiments, that is, 88 clinical-laboratory experiments were carried out, of which 48 experiments with genomic DNA samples with the established negative status of the presence of KRAS gene mutations and 40 experiments with genomic DNA samples with the established positive status of the presence of KRAS gene mutations. Analysis and evaluation of the results of clinical laboratory tests of the medical product "Kit of Reagents for Determination of the Status of KRAS Gene Mutations by PCR-RV Method in a Sample of Human Genomic DNA from Samples of Paraffin-Fixed Tissue (Test-KRAS-tissue) according to TU 21.20.23-006-97638376-2016 "confirmed that it allows to carry out qualitative determination of the status of six mutations of the twelfth codon (Gly12Asp, Gly12Ala, Gly12Arg, Gly12Val, Gly12Ser, Gly12Cys) and one mutation of the thirteenth codon (Gly13Asp) the KRAS gene by real-time allele-specific PCR in human genomic DNA sample from paraffin-fixed tissue samples, with high diagnostic sensitivity rates of 90.9% and diagnostic specificity of 95.0% with a confidence probability of 90%. Reproducibility of results is 100%, which confirms the high reliability of the set.

Three-dimensional fast single-point macromolecular proton fraction mapping of the human brain at 0.5 Tesla.

Fast single-point macromolecular proton fraction (MPF) mapping is a recent magnetic resonance imaging (MRI) method enabling quantitative assessment of myelin content in neural tissues. To date, the reported technical implementations of MPF mapping utilized high-field MRI equipment (1.5 T or higher), while low-field applications might pose challenges due to signal-to-noise ratio (SNR) limitations and short T1 . This study aimed to evaluate the feasibility of MPF mapping of the human brain at 0.5 T. The three-dimensional MPF mapping protocol was implemented according to the single-point synthetic-reference method, which includes three spoiled gradient-echo sequences providing proton density, T1 , and magnetization transfer contrast weightings. Whole-brain MPF maps were obtained from three healthy volunteers with spatial resolution of 1.5×1.5×2 mm3 and the total scan time of 19 minutes. MPF values were measured in a series of white and gray matter structures and compared with literature data for 3 T magnetic field. MPF maps enabled high contrast between white and gray matter with notable insensitivity to paramagnetic effects in iron-rich structures, such as globus pallidus, substantia nigra, and dentate nucleus. MPF values at 0.5 T appeared in close agreement with those at 3 T. This study demonstrates the feasibility of fast MPF mapping with low-field MRI equipment and the independence of brain MPF values of magnetic field. The presented results confirm the utility of MPF as an absolute scale for MRI-based myelin content measurements across a wide range of magnetic field strengths and extend the applicability of fast MPF mapping to inexpensive low-field MRI hardware.

Intercellular mediators in bone remodeling regulation in the experimental renal pathology / Mediadores intercelulares de la regulación de la remodelación ósea en un modelo experimental de patología renal

Bone metabolism disorders are characterized by an imbalance of bone resorption and formation in the bone remodeling process. Glucocorticoids that are used to treat kidney diseases exacerbate these disorders. P-selectin and galectin-3 are molecules involved in the sclerotic process in kidney, whereas bone resorption is regulated by the interaction between the nuclear factor activator kappa b receptor (RANK), its ligand (RANKL) and the RANKL decoy receptor osteoprotegerin (OPG). The aim of this study was to investigate the cellular and molecular mechanisms of disruption of bone remodeling regulation processes, reflected by intercellular mediators (RANKL, OPG, P-selectin and galectin-3) in chronic kidney disease experimental model treated with glucocorticoids. Rats were divided into four groups of 10 animals each. The first group, the control group, included intact animals. The second group consisted of rats with impaired bone remodeling resulting from chronic kidney disease (experimental group (CKD). The third group was a group of animals with impaired bone remodeling due to exposure to glucocorticoids (experimental group (GCs)). The fourth group consisted of rats with impaired bone remodeling in chronic kidney disease, followed by exposure to glucocorticoids (experimental group (CKD + GCs)). The effects of CKD and glucocorticoid were evaluated biochemically, histologically and by measuring bone density. An enzymelinked immunoassay was used to measure intercellular mediator levels in the serum. The bone density in the experimental groups was reduced compared to the control group. RANKL levels in animals of three experimental groups were higher than in intact animals. Serum levels of OPG were higher in CKD and GCs groups than in intact animals. At the same time, in the animals' blood serum of the CKD + GCs group, the levels of OPG were lower, than those in animals from the control group. The levels of galectin-3 in the serum of the experimental groups GCs and CKD + GCs were lower than in intact animals. The serum levels of galectin-3 in animals of the CKD group were higher than those in animals from the control group. The levels of P-selectin were lower in the serum of the GCs group than in intact animals. At the same time, the levels of P-selectin were higher in the CKD and CKD + GCs groups, than those in animals from the control group. In conclusion, the study of the complex system of bone remodeling regulation, which includes many factors and their interactions, may lead to the development of new methods for treating patients with chronic kidney disease in order to prevent osteoporosis in the future. (AU)

Las enfermedades metabólicas óseas se caracterizan por un desequilibrio en el proceso de remodelación ósea en los que participan mediadores tales como receptor del activador del factor nuclear- kappa- b (RANK), su ligando (RANKL) y la osteoprotegerina (OPG). Los glucocorticoides, recuentemente empleados en el tratamiento de la enfermedad renal crónica, exacerban este desequilibrio. En la enfermedad esclerótica renal, las moléculas de adhesión celular P-selectina and galectina-3 tienen un rol fundamental. El objetivo de esta trabajo fue estudiar las alteraciones en los mediadores de la remodelación ósea (RANKL, OPG, P-selectina and galectina-3) en un modelo de enfermedad renal crónica con tratamiento glucocorticoideo. Ratas Wistar hembras fueron divididos en 4 grupos: control (C); enfermedad renal crónica con afección de la remodelación ósea (ERC); animales con afección de la remodelación ósea expuestos a glucocorticoides (GC); enfermedad renal crónica con afección de la remodelación ósea tratados con glucocorticoides (ERC+GC). Los efectos de la ERC y los GC fueron evaluados bioquímicamente, histológicamente y por medición de la densidad ósea. RANKL, OPG, Pselectina and galectina-3 se cuantificaron en muestras de sangre venosa empleando enzimoinmuno análisis. En los 3 grupos experimentales la densidad ósea se evidenció reducida y los niveles séricos de RANKL elevados respecto al grupo control. Los niveles de OPG en los grupos ERC y GC fueron superiores mientras que en el grupo ERC+GC menores respecto a los animales controles. Galectina 3 plasmática en GC y ERC+GC se encontró reducida y aumentada en los animales ERC, en comparación con los animales controles. La concentración sérica de P-selectina sérica fue mayor en los grupos ERC y ERC+GC, y menor en los animales GC respecto a los niveles plasmáticos de los animales intactos. El avance del conocimiento sobre la regulación de la remodelación ósea a través de la interacción de mediadores sistémicos, en un futuro, puede conducir al desarrollo de nuevas estrategias terapéuticas para la prevención de la osteoporosis en pacientes con enfermedad renal crónica. (AU)

The Managment of cervical spine abnormalities in children with spondyloepiphyseal dysplasia congenita: Observational study.

Spondyloepiphyseal dysplasia congenita (SEDC) is an autosomal dominant disorder, characterized by disproportionate dwarfism with short spine, short neck associated with variable degrees of coxa vara. Cervical cord compression is the most hazardous skeletal deformity in patients with SEDC which requires special attention and management.Ten patients with the clinical and the radiographic phenotypes of spondyloepiphyseal dysplasia congenita have been recognized and the genotype was compatible with single base substitutions, deletions or duplication of part of the COL2A1 gene (6 patients out of ten have been sequenced). Cervical spine radiographs showed apparent atlantoaxial instability in correlation with odontoid hypoplasia or os-odontoideum.Instability of 8 mm or more and or the presence of symptoms of myelopathy were the main indications for surgery. Posterior cervical fusion from the occiput or C1-3, decompression of C1-2 and application of autorib transfer followed by halo vest immobilization have been applied accordingly.Orthopedic management of children with spondyloepiphyseal dysplasia congenita (SEDC) should begin with the cervical spine to avoid serious neurological deficits and or mortality.

Anomaly-Related Pathologic Atlantoaxial Displacement in Pediatric Patients.

OBJECTIVE: To analyze clinical and radiologic features of pathologic atlantoaxial displacement (PAAD) in pediatric patients and to compose a treatment algorithm for anomaly-related PAAD. BACKGROUND: Criteria of different types of PAAD and treatment algorithms have been widely reported in the literature but are difficult to apply to patients with odontoid abnormalities, C2-C3 block, spina bifida C1, and children. METHODS: We evaluated results of treatment of 29 pediatric patients with PAAD caused by congenital anomalies of the craniovertebral junction (CVJ), treated in Ilizarov Center in 2009-2017, including 20 patients with atlantoaxial displacement (AAD) and 9 patients with atlantoaxial rotatory fixation. RESULTS: There were 14 males (48.3%) and 15 females (51.7%). We singled out 3 groups of patients: nonsyndromic (6 patients, 20.7%), Klippel-Feil syndrome (13 patients, 44.8%), and syndromic (10 patients, 34.5%). Odontoid abnormalities and C1 dysplasia were widely represented in the syndromic group. Local symptoms predominated in the nonsyndromic and KFS groups. In the syndromic group, all patients had AAD and myelopathy. A pronounced decrease of space available for chord C1 and increase of anterior atlantodental interval were noted compared with other groups. CONCLUSIONS: We present a unified treatment algorithm of pediatric anomaly-related PAAD. Syndromic AAD are often accompanied by anterior and central dislocation and myelopathy and atlantooccipital dissociation. These patients require early aggressive surgical treatment. Nonsyndromic and Klippel-Feil syndrome AAD, atlantoaxial subluxation, and atlantoaxial fixation often manifest by local symptoms and need to eliminate CVJ instability. Existing classifications of symptomatic atlantoaxial displacement are not always suitable for patients with CVJ abnormalities.

Surgical Management of Myelomeningocele-Related Spinal Deformities.

OBJECTIVE: To evaluate the optimal timing and type of surgical treatment of myelomeningocele (MMC)-related spinal deformities and long-term follow-up of surgical treatment. METHODS: We reviewed and presented clinical pictures, treatment strategies and results of 20 patients with MMC-related spinal deformities treated at our center between 2010 and 2017. RESULTS: The average patient age was 6.3 years. The average preoperative neurologic status according to a modified Japan Orthopedic Association (mJOA) scale was 7.3 points (Benzel's modification). Average functional status was 41 points according to a functional independent measure scale (FIM). The average angle of kyphosis was 83.7°, that of scoliosis was 36.7°, and that of lordosis was 67° (Cobb angles). The average duration of surgery was 234 minutes, and the average total blood loss was 175 mL. The average angle of kyphosis correction was 61°, that of scoliosis correction was 25°, and that of lordosis correction was 25° (Cobb angles). The average duration of hospitalization was 16.6 days, and the average follow-up was 34.5 months. The total number of complications was 13. Reoperation was required in 9 cases. Neurologic status according to the mJOA scale improved by 0.6 point on average. Functional status according to the FIM increased by 6.6 points on average. CONCLUSIONS: Early surgical correction of MMC-related spinal deformities improves body balance and quality of life. The dual growing rod technique is safe and effective in cases of moderate neuromuscular spinal deformities at an early age. Kyphectomy is a challenging procedure with high complication rates, especially skin problems, but there are no alternative procedures for cases of heavy rigid kyphosis.

Surgical Treatment of Thoracolumbar Segmental Spinal Dysgenesis: Optimal Type of Fusion.

OBJECTIVES: We sought to evaluate long-term results of surgical treatment of thoracolumbar segmental spinal dysgenesis (SSD). METHODS: We analyzed 8 patients with thoracolumbar SSD treated in our institution. Each case was evaluated for specific clinical and radiologic criteria and types and outcomes of treatment. RESULT: The average age of primary surgery was 3.4 years (median 3.4 years, range 1.7-7 years). The average correction of kyphosis was 49.3° (mean 45°, from 25°-75°) and scoliosis 10.6° (mean 10°, from 0°-25°). Average follow-up time was 3.2 years (mean 2.6 years, from 1.8-5.6 years). Neurologic improvement was also achieved in all patients. The Japanese Orthopaedic Association scale score (Benzel's modification) was increased by 2.5 points on average (mean 2.5 points, from 2-5 points). One patient had complications: pseudarthrosis and rod fracture followed by refusion. CONCLUSIONS: Our treatment strategy provides favorable deformity correction and neurologic improvement. It is limited by immature vertebral structures in newborns and infants, who should be carefully monitored from birth with braces until they reach the age when a fixing tool can be used.

The Ability of Microbial Community of Lake Baikal Bottom Sediments Associated with Gas Discharge to Carry Out the Transformation of Organic Matter under Thermobaric Conditions.

The ability to compare the composition and metabolic potential of microbial communities inhabiting the subsurface sediment in geographically distinct locations is one of the keys to understanding the evolution and function of the subsurface biosphere. Prospective areas for study of the subsurface biosphere are the sites of hydrocarbon discharges on the bottom of the Lake Baikal rift, where ascending fluxes of gas-saturated fluids and oil from deep layers of bottom sediments seep into near-surface sediment. The samples of surface sediments collected in the area of the Posolskaya Bank methane seep were cultured for 17 months under thermobaric conditions (80°C, 5 MPa) with the addition of complementary organic substrate, and a different composition for the gas phase. After incubation, the presence of intact cells of microorganisms, organic matter transformation and the formation of oil biomarkers was confirmed in the samples, with the addition of Baikal diatom alga Synedra acus detritus, and gas mixture CH4:H2:CO2. Taxonomic assignment of the 16S rRNA sequence data indicates that the predominant sequences in the enrichment were Sphingomonas (55.3%), Solirubrobacter (27.5%) and Arthrobacter (16.6%). At the same time, in heat-killed sediment and in sediment without any additional substrates, which were cultivated in a CH4 atmosphere, no geochemical changes were detected, nor the presence of intact cells and 16S rRNA sequences of Bacteria and Archaea. This data may suggest that the decomposition of organic matter under culturing conditions could be performed by microorganisms from low-temperature sediment layers. One possible explanation of this phenomenon is migration of the representatives of the deep thermophilic community through fault zones in the near surface sediment layers, together with gas-bearing fluids.

Horizontal gene transfer from genus agrobacterium to the plant linaria in nature.

Genes can be transferred horizontally between prokaryotes and eukaryotes in nature. The best-studied examples occur between Agrobacterium rhizogenes and certain Nicotiana spp. To investigate possible additional cases of horizontal gene transfer in nature between Agrobacterium and plants, a real-time polymerase chain reaction-based approach was employed to screen 127 plant species, belonging to 38 families of Dicotyledones, for the presence of oncogenes homologous to the transfer DNA fragments (T-DNA) from both A. tumefaciens and A. rhizogenes. Among all of the analyzed plant species, we found that only Linaria vulgaris contained sequences homologous to the T-DNA of A. rhizogenes. All screened L. vulgaris plants from various parts of Russia contained the same homologous sequences, including rolB, rolC, ORF13, ORF14, and mis genes. The same opine gene is found in the species of Nicotiana which contain genes of A. rhizogenes. In L. vulgaris, there are two copies of T-DNA organized as a single tandem imperfect direct repeat. The plant DNA sequence of the site of integration shows similarity to a retrotransposon. This site is most likely silent, suggesting that the T-DNA is not expressed. Attempts to demonstrate expression of the T-DNA genes were negative. Our study indicates that the frequency of gene transfer and fixation in the germline from Agrobacterium to plant hosts is rare in the natural environment.

Quantitative assessment of regulatory proteins in blood as markers of radiation effects in the late period after occupational exposure.

The objective of this research was quantitative assessment of serum and membrane regulatory proteins in blood from nuclear workers as markers of radiation-induced alterations in immune homeostasis in the late period after protracted exposure of nuclear workers with different doses. The effector and regulatory lymphocytes were measured using a flow cytofluorometer in workers from the main facilities of the Mayak PA (aged ∼60 y up to 80 y) in the late period after combined exposure to external gamma-rays and internal alpha-radiation from incorporated 239Pu. The control group included non-occupationally exposed members of the Ozyorsk population matched by gender and age to the group of Mayak workers. Thirty serum proteins involved in regulation of immune homeostasis, such as growth factors, multifunctional interleukins, pro- and anti-inflammatory cytokines, and their receptors, were measured using ELISA in blood serum specimens from the Radiobiology Human Tissue Repository. The dosimetry estimates were obtained using Doses-2005. The correlation analysis revealed a statistically significant direct relationship of T-killers and plutonium body burden and a decreasing level of T-helpers with accumulated external dose in exposed individuals. There were differences in expression of membrane markers in young regulatory cells (double null T-lymphocytes, NKT-lymphocytes, regulatory T-cells, and an increase of activated forms of T-lymphocytes), which indicated an active role of regulatory cells in maintaining immune homeostasis in terms of protracted exposure. The assessment of regulatory proteins in blood indicated that growth factors (EGF, TGF-ß1, PDGF), multifunctional interleukins (IL-17A, IL-18), and pro-inflammatory cytokines (IL-1ß and INF-γ) could be potential markers of radiation-induced alterations in protein status. An imbalance of pro- and antiinflammatory proteins in blood and variations of protein profiles at the lower exposure levels (gamma-ray dose <1 Gy, plutonium body burden <0.74 kBq) in the late period after protracted exposure were less pronounced than at the higher exposure levels, which was probably explained by compensatory-adaptive responses in the late period among senile individuals with polypathology.

Immunolocalization of an alternative respiratory chain in Antonospora (Paranosema) locustae spores: mitosomes retain their role in microsporidial energy metabolism.

Microsporidia are a group of fungus-related intracellular parasites with severely reduced metabolic machinery. They lack canonical mitochondria, a Krebs cycle, and a respiratory chain but possess genes encoding glycolysis enzymes, a glycerol phosphate shuttle, and ATP/ADP carriers to import host ATP. The recent finding of alternative oxidase genes in two clades suggests that microsporidial mitosomes may retain an alternative respiratory pathway. We expressed the fragments of mitochondrial chaperone Hsp70 (mitHsp70), mitochondrial glycerol-3-phosphate dehydrogenase (mitG3PDH), and alternative oxidase (AOX) from the microsporidium Antonospora (Paranosema) locustae in Escherichia coli. Immunoblotting with antibodies against recombinant polypeptides demonstrated specific accumulation of both metabolic enzymes in A. locustae spores. At the same time comparable amounts of mitochondrial Hsp70 were found in spores and in stages of intracellular development as well. Immunoelectron microscopy of ultrathin cryosections of spores confirmed mitosomal localization of the studied proteins. Small amounts of enzymes of an alternative respiratory chain in merogonial and early sporogonial stages, alongside their accumulation in mature spores, suggest conspicuous changes in components and functions of mitosomes during the life cycle of microsporidia and the important role of these organelles in parasite energy metabolism, at least at the final stages of sporogenesis.

Ultrastructure and molecular phylogeny of Anisofilariata chironomi g.n. sp.n. (Microsporidia: Terresporidia) from Chironomus plumosus L. (Diptera: Chironomidae).

Larvae of Chironomus plumosus, collected in North-Western Russia in September 2008, were infected with a microsporidium possessing broadly oval uninucleate spores in sporophorous vesicles. Sporogony and spore ultrastructure of this microsporidium differed from that of known microsporidian species, suggesting establishment of a new species, Anisofilariata chironomi, being a type species of a new genus. Sporogony di-, tetra-, octo-, and 16-sporoblastic. Fixed and stained spores are 4.7-6.8 x 3.4-5.4 microm in size, the spore measurements varying depending upon the number of spores in the sporophorous vesicle. The polaroplast is bipartite, with anterior and posterior parts composed of very thin and thick lamellae, respectively, and occupies the major volume of the spore. The polar filament is anisofilar, with two broad proximal and 10-13 narrow distal coils arranged in 2-4 layers. The sporophorous vesicle is bounded by a thin membrane and contains multiple tubular structures. Small subunit ribosomal DNA phylogeny showed basal position of the new microsporidium to a cluster uniting microsporidia infecting ciliates (Euplotespora binucleata), microcrustaceans (Glugoides intestinalis, Mrazekia macrocyclopis), lepidopteran insects (Cystosporogenes spp., Endoreticulatus spp.) and human (Vittaforma corneae), nested within Clade IV sensu Vossbrinck and Debrunner-Vossbrinck (2005 Folia Parasitol 52:131-142). No close phylogenetic relationships were found between A. chironomi and microsporidia from other dipteran hosts.

Greater nicotinic acetylcholine receptor density in smokers than in nonsmokers: a PET study with 2-18F-FA-85380.

UNLABELLED: Assays of human postmortem brain tissue have revealed that smokers have greater densities of high-affinity nicotinic acetylcholine receptors (nAChRs) in several brain regions than do nonsmokers or exsmokers. Quantitative PET imaging of nAChRs in humans has recently been reported using the alpha4beta2* subtype-specific radioligand 2-(18)F-FA-85380 (2FA). METHODS: We used PET and 2FA to measure total volumes of distribution corrected for the free fraction of 2FA in plasma (V(T)/f(P)) in 10 nonsmokers and 6 heavy smokers (>14 cigarettes/d; abstinent for >36 h). Dynamic PET scans were performed over 8 h, commencing immediately after a bolus injection of 2FA. Anatomic sampling was performed on PET images that were coregistered to MR images acquired from each volunteer. Data were analyzed by Logan plots and by 1- and 2-tissue-compartment models using unbound, unmetabolized arterial 2FA concentration as the input function. RESULTS: All modeling methods yielded similar results. V(T)/f(P) was significantly higher in smokers than in nonsmokers in all brain regions tested, except the thalamus. We used measures of V(T)/f(P) and estimates of nondisplaceable volume of distribution and found 25%-200% higher values in smokers than in nonsmokers for the volume of distribution for the specific binding compartment in the frontal cortex, midbrain, putamen, pons, cerebellum, and corpus callosum. These findings were consistent with voxel-based analysis using statistical parametric mapping. CONCLUSION: Our findings suggest that PET with 2FA can be used to study the role of nicotine-induced upregulation of nAChRs in active smokers and during smoking cessation.

Aspartyl-tRNA synthetase is the target of peptide nucleotide antibiotic Microcin C.

Microcin C is a ribosome-synthesized heptapeptide that contains a modified adenosine monophosphate covalently attached to the C-terminal aspartate. Microcin C is a potent inhibitor of bacterial cell growth. Based on the in vivo kinetics of inhibition of macromolecular synthesis, Microcin C targets translation, through a mechanism that remained undefined. Here, we show that Microcin C is a subject of specific degradation inside the sensitive cell. The product of degradation, a modified aspartyl-adenylate containing an N-acylphosphoramidate linkage, strongly inhibits translation by blocking the function of aspartyl-tRNA synthetase.

In vitro characterization of 6-[18F]fluoro-A-85380, a high-affinity ligand for alpha4beta2* nicotinic acetylcholine receptors.

Nicotinic acetylcholine receptors are involved in tobacco dependence and several other neuropathologies (e.g., Alzheimer's disease, Parkinson's disease), as well as in attention, learning, and memory. Performing in vivo imaging of these receptors in humans holds great promise for understanding their role in these conditions. Recently, three radiohalogenated analogs of 3-(2(S)-azetidinylmethoxy)pyridine (A- 85380) were used successfully for the in vivo visualization of alpha4beta2* nicotinic receptors in the human brain with PET/SPECT. Herein, we present the results of the in vitro characterization of one of these radioligands, 6-[18F]fluoro-3-(2(S)-azetidinylmethoxy)-pyridine (6-[18F]fluoro-A-85380), which is a fluoro-analog of the potent nonopioid analgesic ABT-594. In human postmortem cortical tissue, 6-[18F]fluoro-A-85380 reversibly binds with high affinity to a single population of sites (Kd = 59 pM at 37 degrees C, Bmax = 0.7 pmol/g tissue). The binding is fully reversible and is characterized at 37 degrees C by T(1/2assoc) = 2.2 min (at a ligand concentration of 39 pM) and by T(1/2dissoc) = 3.6 min. 6-Fluoro-A-85380 exhibits clear selectivity for alpha4beta2* over the other major mammalian nicotinic receptor subtypes: alpha7, alpha3beta4, and muscle-type. These results suggest that 6-[18F]fluoro-A-85380 is a promising radioligand for in vivo imaging of brain alpha4beta2* nicotinic receptors.

2-[18F]F-A-85380: PET imaging of brain nicotinic acetylcholine receptors and whole body distribution in humans.

Noninvasive imaging of nicotinic acetylcholine receptors (nAChRs) in the human brain in vivo is critical for elucidating the role of these receptors in normal brain function and in the pathogenesis of brain disorders. Here we report the first in vivo visualization of human brain areas containing nAChRs by using PET and 2-[18F]fluoro-3-(2(S)azetidinylmethoxy)pyridine (2-[18F]FA). We acquired scans from six healthy non-smoking volunteers after i.v. bolus administration of 2-[18F]FA (1.6 MBq/kg or 0.043 +/- 0.002 mCi/kg). This dose was sufficient for visualizing nAChRs in the thalamus up to 5 h after injection. There were no adverse effects associated with administration of no-carrier-added 2-[18F]FA (1.3-10 pmol/kg). Consistent with the distribution of nAChRs in human brain, accumulated radioactivity was greatest in thalamus, intermediate in the midbrain, pons, cerebellum, and cortex; and least in white matter. As approximately 90% of the injected radioactivity was eliminated via the urine (biological half-life ca. 4 h), the urinary bladder wall received the highest radiation dose. The estimate of radiation dose equivalent to the urinary bladder wall (ca. 180 +/- 30 mSv/MBq or 0.7 rem/mCi with a 2.4 h void interval) suggests that multiple studies could be performed in a single subject. The results predict that quantitative PET imaging of nAChRs in human brain with 2-[18F]FA is feasible.