A new threshold for kidney asymmetry improves association with abnormal renal-aortic ratio for diagnosis of renal artery stenosis.

BACKGROUND: Renal artery stenosis (RAS) reflects more widespread atherosclerosis deposition and is associated with high morbidity and mortality. According to the guidelines, a discrepancy in the size of the kidneys of over 15 mm found in an ultrasound should initiate the RAS diagnostic algorithm. This study aims to find the optimal threshold for renal asymmetry that better reflects the frequency of a significantly abnormal renal-aortic ratio (RAR), justifying further RAS diagnostic workup, than the currently used cut-off of 15 mm difference in renal diameters. METHODS: The analysis included 1175 patients (mean age: 52 years, IQR: 38-66, men/women: 597/578) who underwent Doppler ultrasonography screening of renal arteries with recorded kidney size and RAR calculation. Ultrasound features of RAS were defined as a RAR greater than 3.5 or signs of renal artery occlusion. Receiver operating characteristic (ROC) curves were created and analyzed for absolute differences in kidney size and abnormal RAR. We calculated the area under the curve (AUC) and optimal cut-off values for sensitivity and specificity analysis. RESULTS: The final analysis included 169 patients with a significant difference in renal dimension. RAS features were met in 61 patients. According to ROC curve analysis, the optimal index of renal asymmetry was 12 mm. The sensitivity and specificity for this method were 82.0% and 83.3%, respectively, and AUC was 86.3%. CONCLUSION: Changing the definition of a significant difference in kidney size from 15 mm to 12 mm increases sensitivity and specificity for abnormal RAR and this finding may accelerate the diagnosis of RAS.

The Regulator OmpR in Yersinia enterocolitica Participates in Iron Homeostasis by Modulating Fur Level and Affecting the Expression of Genes Involved in Iron Uptake.

In this study, we found that the loss of OmpR, the response regulator of the two-component EnvZ/OmpR system, increases the cellular level of Fur, the master regulator of iron homeostasis in Y. enterocolitica. Furthermore, we demonstrated that transcription of the fur gene from the YePfur promoter is subject to negative OmpR-dependent regulation. Four putative OmpR-binding sites (OBSs) were indicated by in silico analysis of the fur promoter region, and their removal affected OmpR-dependent fur expression. Moreover, OmpR binds specifically to the predicted OBSs which exhibit a distinct hierarchy of binding affinity. Finally, the data demonstrate that OmpR, by direct binding to the promoters of the fecA, fepA and feoA genes, involved in the iron transport and being under Fur repressor activity, modulates their expression. It seems that the negative effect of OmpR on fecA and fepA transcription is sufficient to counteract the indirect, positive effect of OmpR resulting from decreasing the Fur repressor level. The expression of feoA was positively regulated by OmpR and this mode of action seems to be direct and indirect. Together, the expression of fecA, fepA and feoA in Y. enterocolitica has been proposed to be under a complex mode of regulation involving OmpR and Fur regulators.

Age-related values of aortic pulse wave velocity in healthy subjects measured by Doppler echocardiography.

Aortic pulse wave velocity (aPWV) is a measure of aortic stiffness, which is an indicator of vascular aging and prognostic marker for cardiovascular complications. aPWV can be measured with various methods, but with different reference values depending on the technique used. Therefore, we decided to evaluate age-related values of aPWV, measured by Doppler echocardiography. We included 134 healthy adults (mean age 44.1 ± 13.2 years, 54% of females) divided into five groups based on age decades (D1 21-30 years, n = 29; D2 31-40 years, n = 24; D3 41-50 years, n = 34; D4 51-60 years, n = 25; and D5 61-70 years, n = 22). With the use of a cardiac probe and ECG tracing, ten Doppler waveforms were sequentially recorded, first in the distal aortic arch, and than in the left external iliac artery. Transit time was measured as a delay of the foot of the Doppler waveform in the distal, relative to the proximal location. The distance was measured over the body surface. aPWV was calculated as distance/transit time. Median aPWV in the whole group was 5.05 m/s [4.55-5.99] and did not differ according to sex (females, 5.28 m/s [4.50-6.1] vs. males, 4.95 m/s [4.59-5.77], p = 0.46). Mean aPWV values with 95% confidence intervals (95% CI) for each decade were as follows: D1, 4.54 m/s (4.37-4.72), D2, 4.61 m/s (4.36-4.87), D3, 5.11 m/s (4.89-5.33), D4, 6.04 m/s (5.63-6.45), and D5, 6.77 m/s (6.35-7.19). We report age-related values of aPWV, in a healthy population, measured by Doppler echocardiography. This may be helpful in future research exploring the associations between aortic stiffness, cardiac function, and cardiovascular risk.

Transcriptional Organization of the Stability Module of Broad-Host-Range Plasmid RA3, from the IncU Group.

The broad-host-range (BHR) conjugative plasmids have developed diverse adaptive mechanisms defining the range of their promiscuity. The BHR conjugative RA3 plasmid, the archetype of the IncU group, can transfer between, replicate in, and be maintained in representatives of Alpha-, Beta-, and Gammaproteobacteria Its stability module encompasses ten open reading frames (ORFs) apparently organized into five operons, all transcribed in the same direction from several strong promoters that are tightly regulated either by autorepressors or by global plasmid-encoded regulators. In this paper, we demonstrate that owing to an efficient RNA polymerase (RNAP) read-through, the transcription from the first promoter, orf02p, may continue through the whole module. Moreover, an analysis of mRNA produced from the wild-type (WT) stability module and its deletion variants deprived of particular internal transcription initiation sites reveals that in fact each operon may be transcribed from any upstream promoter, giving rise to multicistronic transcripts of variable length and creating an additional level of gene expression control by transcript dosage adjustment. The gene expression patterns differ among various hosts, indicating that promoter recognition, regulation, and the RNAP read-through mechanisms are modulated in a species-specific manner.IMPORTANCE The efficiently disseminating conjugative or mobilizable BHR plasmids play key roles in the horizontal spread of genetic information between closely related and phylogenetically distant species, which can be harmful from the medical, veterinary, or industrial point of view. Understanding the mechanisms determining the plasmid's ability to function in diverse hosts is essential to help limit the spread of undesirable plasmid-encoded traits, e.g., antibiotic resistance. The range of a plasmid's promiscuity depends on the adaptations of its transfer, replication, and stability functions to the various hosts. IncU plasmids, with the archetype plasmid RA3, are considered to constitute a reservoir of antibiotic resistance genes in aquatic environments; however, the molecular mechanisms determining their adaptability to a broad range of hosts are rather poorly characterized. Here, we present the transcriptional organization of the stability module and show that the gene transcript dosage effect is an important determinant of the stable maintenance of RA3 in different hosts.

A very rare origin of a tumor in the right atrium.

Primary cardiac tumors are extremely uncommon but metastases can result from direct invasion from the mediastinum, hematogenous spread or extension of the tumor into the vena cava and the right atrium. A CASE REPORT: A 37-year-old male with no previous history of chronic diseases was admitted to the hospital due to non-specific chest discomfort, non-productive cough and weakness lasting for several weeks. Physical examination was unremarkable except for tachycardia and bibasal rales. Chest radiogram revealed multiple pulmonary lesions suggesting metastases. A mass in the right adrenal gland was found on abdominal ultrasound and CT scan. In addition, a pathological lesion in the inferior vena cava extending to the right atrium was detected. Echocardiography revealed a pedunculated mass measuring 2.3x1.5 cm, located in the right atrium, which originated from the inferior vena cava. During the diastole, it prolapsed to the right ventricle but did not significantly affect blood flow through the tricuspid valve. Adrenal tumor biopsy revealed adrenocortical cancer and treatment with mitotane was started. After a seizure episode, brain MRI was performed and showed metastases surrounded by edema. Due to the patient's poor general condition and progression of the disease during mitotane treatment was later withdrawn and the patient was referred for the hospice care where he died 2 months later. CONCLUSIONS: Adrenocortical cancer is a rare malignant neoplasm with an estimated annual incidence of 4-12 cases per 1,000,000. It is characterized by a tendency for local invasion and multiple metastases to the lungs, liver and bones. In the literature, there are only a few cases of adrenocortical cancer directly extending from the inferior vena cava to the right atrium.

OmpR-Mediated Transcriptional Regulation and Function of Two Heme Receptor Proteins of Yersinia enterocolitica Bio-Serotype 2/O:9.

We show that Yersinia enterocolitica strain Ye9 (bio-serotype 2/O:9) utilizes heme-containing molecules as an iron source. The Ye9 genome contains two multigenic clusters, hemPRSTUV-1 and hemPRST-2, encoding putative heme receptors HemR1 and HemR2, that share 62% amino acid identity. Expression of these proteins in an Escherichia coli mutant defective in heme biosynthesis allowed this strain to use hemin and hemoglobin as a source of porphyrin. The hemPRSTUV-1 and hemPRST-2 clusters are organized as operons, expressed from the phem-1 and weaker phem-2 promoters, respectively. Expression of both operons is negatively regulated by iron and the iron-responsive transcriptional repressor Fur. In addition, OmpR, the response regulator of two component system (TCSs) EnvZ/OmpR, represses transcription of both operons through interaction with binding sequences overlapping the -35 region of their promoters. Western blot analysis of the level of HemR1 in ompR, fur, and ompRfur mutants, showed an additive effect of these mutations, indicating that OmpR may regulate HemR expression independently of Fur. However, the effect of OmpR on the activity of the phem-1 promoter and on HemR1 production was observed in both iron-depleted and iron-replete conditions, i.e., when Fur represses the iron-regulated promoter. In addition, a hairpin RNA thermometer, composed of four uracil residues (FourU) that pair with the ribosome-binding site in the 5'-untranslated region (5'-UTR) of hemR1 was predicted by in silico analysis. However, thermoregulated expression of HemR1 could not be demonstrated. Taken together, these data suggest that Fur and OmpR control iron/heme acquisition via a complex mechanism based on negative regulation of hemR1 and hemR2 at the transcriptional level. This interplay could fine-tune the level of heme receptor proteins to allow Y. enterocolitica to fulfill its iron/heme requirements without over-accumulation, which might be important for pathogenic growth within human hosts.

Global Transcriptional Regulation of Backbone Genes in Broad-Host-Range Plasmid RA3 from the IncU Group Involves Segregation Protein KorB (ParB Family).

The KorB protein of the broad-host-range conjugative plasmid RA3 from the IncU group belongs to the ParB family of plasmid and chromosomal segregation proteins. As a partitioning DNA-binding factor, KorB specifically recognizes a 16-bp palindrome which is an essential motif in the centromere-like sequence parSRA3, forms a segrosome, and together with its partner IncC (ParA family) participates in active DNA segregation ensuring stable plasmid maintenance. Here we show that by binding to this palindromic sequence, KorB also acts as a repressor for the adjacent mobC promoter driving expression of the mobC-nicoperon, which is involved in DNA processing during conjugation. Three other promoters, one buried in the conjugative transfer module and two divergent promoters located at the border between the replication and stability regions, are regulated by KorB binding to additional KorB operators (OBs). KorB acts as a repressor at a distance, binding to OBs separated from their cognate promoters by between 46 and 1,317 nucleotides. This repressor activity is facilitated by KorB spreading along DNA, since a polymerization-deficient KorB variant with its dimerization and DNA-binding abilities intact is inactive in transcriptional repression. KorB may act as a global regulator of RA3 plasmid functions in Escherichia coli, since its overexpression in transnegatively interferes with mini-RA3 replication and stable maintenance of RA3.

Mobility and generation of mosaic non-autonomous transposons by Tn3-derived inverted-repeat miniature elements (TIMEs).

Functional transposable elements (TEs) of several Pseudomonas spp. strains isolated from black shale ore of Lubin mine and from post-flotation tailings of Zelazny Most in Poland, were identified using a positive selection trap plasmid strategy. This approach led to the capture and characterization of (i) 13 insertion sequences from 5 IS families (IS3, IS5, ISL3, IS30 and IS1380), (ii) isoforms of two Tn3-family transposons--Tn5563a and Tn4662a (the latter contains a toxin-antitoxin system), as well as (iii) non-autonomous TEs of diverse structure, ranging in size from 262 to 3892 bp. The non-autonomous elements transposed into AT-rich DNA regions and generated 5- or 6-bp sequence duplications at the target site of transposition. Although these TEs lack a transposase gene, they contain homologous 38-bp-long terminal inverted repeat sequences (IRs), highly conserved in Tn5563a and many other Tn3-family transposons. The simplest elements of this type, designated TIMEs (Tn3 family-derived Inverted-repeat Miniature Elements) (262 bp), were identified within two natural plasmids (pZM1P1 and pLM8P2) of Pseudomonas spp. It was demonstrated that TIMEs are able to mobilize segments of plasmid DNA for transposition, which results in the generation of more complex non-autonomous elements, resembling IS-driven composite transposons in structure. Such transposon-like elements may contain different functional genetic modules in their core regions, including plasmid replication systems. Another non-autonomous element "captured" with a trap plasmid was a TIME derivative containing a predicted resolvase gene and a res site typical for many Tn3-family transposons. The identification of a portable site-specific recombination system is another intriguing example confirming the important role of non-autonomous TEs of the TIME family in shuffling genetic information in bacterial genomes. Transposition of such mosaic elements may have a significant impact on diversity and evolution, not only of transposons and plasmids, but also of other types of mobile genetic elements.

Revealing properties of the KfrA plasmid protein via combined DLS, AFM and electrokinetic measurements.

Physicochemical characteristics of the plasmid KfrA protein in electrolyte solutions were done using a combination of dynamic light scattering (DLS), atomic force microscopy (AFM) and electrokinetic methods. The size of the protein was determined via the diffusion coefficient measurements using DLS. It was revealed from these measurements that the protein exists in an aggregated state composed of four molecules. The size of the protein was also determined via AFM imaging of single molecules adsorbed on mica from dilute solutions at pH=3.5. It was 10.6 nm in accordance with the value predicted for an aggregate composed of four monomers in a hexagonal configuration. The aggregation number was also confirmed by kinetics measurements carried out under diffusion controlled transport using AFM imaging of proteins. Further characteristics were acquired via KfrA adsorption on polystyrene latex particles (average size of 820 nm). The electrophoretic mobility of the latex and its zeta potential were determined as a function of the coverage of the protein. The maximum monolayer coverage for pH=3.5 was 1.2 mgm(-2). Additionally, from these measurements the effective charge of KfrA tetramer equal to 12 e (elementary charges) was predicted. The KfrA monolayer on latex was used to determine the isoelectric point of the protein, which was pH=4.5. As concluded, the procedures used in our work proved advantageous for a direct determination of aggregation processes and the effective charge if minor amounts of a protein are available.