Diagnostic value of blink reflex in multisystem atrophy, progressive supranuclear palsy and Parkinson disease

Abnormal blink reflex (BR) is a result of reticular brainstem pathways dysfunction and seems to be one of the features of brain degenerative disorders. The aim of the study was to estimate the diagnostic value of blink reflex in neurodegenerative diseases such as: multisystem atrophy (MSA), progressive supranuclear palsy (PSP) and Parkinson disease (PD). Material consisted of 99 patients with clinically probable MSA (51), PSP (28) and PD (20). MSA patients were divided into two subgroups, with dominant cerebellar (MSA-C) and parkinsonian signs (MSA-P). The mean age of patients was 64.9 years (47–79 years); males – 55.3%. Blink reflex was obtained in a typical way. Results The significant differences in mean values of blink reflex latencies between PD and other subgroups (MSA-P, MSA-C, PSP) were found, but all of them were in normal range. In individual patients with PD and PSP (50% and 18%, respectively) delayed R2 latencies were recorded. Conclusions The most frequently abnormal blink reflexes, comparing the MSA, PSP and PD groups, were present in PD patients. We postulate that this may be explained by pathological influence of nigrostriatal pathway on the circuit linking the basal ganglia, cerebellum and brainstem

Molecular Factors and Mechanisms Driving Multidrug Resistance in Uropathogenic Escherichia coli—An Update

The rapid emergence of multidrug-resistant (MDR) bacteria indisputably constitutes a major global health problem. Pathogenic Escherichia coli are listed among the most critical group of bacteria that require fast development of new antibiotics and innovative treatment strategies. Among harmful extraintestinal Enterobacteriaceae strains, uropathogenic E. coli (UPEC) pose a significant health threat. UPEC are considered the major causative factor of urinary tract infection (UTI), the second-most commonly diagnosed infectious disease in humans worldwide. UTI treatment places a substantial financial burden on healthcare systems. Most importantly, the misuse of antibiotics during treatment has caused selection of strains with the ability to acquire MDR via miscellaneous mechanisms resulting in gaining resistance against many commonly prescribed antibiotics like ampicillin, gentamicin, cotrimoxazole and quinolones. Mobile genetic elements (MGEs) such as transposons, integrons and conjugative plasmids are the major drivers in spreading resistance genes in UPEC. The co-occurrence of various bacterial evasion strategies involving MGEs and the SOS stress response system requires further research and can potentially lead to the discovery of new, much-awaited therapeutic targets. Here, we analyzed and summarized recent discoveries regarding the role, mechanisms, and perspectives of MDR in the pathogenicity of UPEC

A Novel Mutator of Escherichia coli Carrying a Defect in the dgt Gene, Encoding a dGTP Triphosphohydrolase▿

A novel mutator locus in Escherichia coli was identified from a collection of random transposon insertion mutants. Several mutators in this collection were found to have an insertion in the dgt gene, encoding a previously characterized dGTP triphosphohydrolase. The mutator activity of the dgt mutants displays an unusual specificity. Among the six possible base pair substitutions in a lacZ reversion system, the G·C→C·G transversion and A·T→G·C transition are strongly enhanced (10- to 50-fold), while a modest effect (two- to threefold) is also observed for the G·C→A·T transition. Interestingly, a two- to threefold reduction in mutant frequency (antimutator effect) is observed for the G·C→T·A transversion. In the absence of DNA mismatch repair (mutL) some of these effects are reduced or abolished, while other effects remain unchanged. Analysis of these effects, combined with the DNA sequence contexts in which the reversions take place, suggests that alterations of the dGTP pools as well as alterations in the level of some modified dNTP derivatives could affect the fidelity of in vivo DNA replication and, hence, account for the overall mutator effects

Diagnostic and Clinical Value of Specific Autoantibodies against Kelch-like 12 Peptide and Nuclear Envelope Proteins in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the presence of antimitochondrial and antinuclear antibodies in patients’ serum. Here, we analyzed the reactivity of autoantibodies against a novel autoantigen, kelch-like 12 (KLHL12) protein, in a cohort of 138 PBC and 90 non-PBC patients. Additionally, we compared the reactivity of KLHL12 with antinuclear envelope antibodies: anti-gp210, anti-p62, and anti-LBR. Commercially available kits and an ‘in-house’ ELISA were used in the studies. Antinuclear envelope antibodies were detected in 65% of PBC patients and the presence of these antibodies was observed more frequently in patients diagnosed with later stages (III/IV) of PBC, according to Ludwig’s classification (p < 0.05) and were found to correlate with a higher concentration of bilirubin. Overall, anti-KLHL12 antibodies were found more frequently in PBC patients than in non-PBC controls (p < 0.001). Anti-KLHL12 antibodies were detected in 36% of the tested PBC cohort, including PBC patients negative for antimitochondrial antibodies. Presence of anti-KLHL12 was also associated with a higher concentration of bilirubin and correlated with fibrosis (p < 0.05). Anti-KLHL12 antibodies were detected in 30% of PBC individuals positive for antinuclear envelope antibodies, while anti-KLHL12 and antinuclear envelope antibodies were found in 17% of all PBC cases. Concluding, our data confirm that antibodies against the KLHL12 protein are highly specific for PBC and when used in combination with other markers, may significantly increase the diagnosis of PBC

Analysis of Autoantibodies against Promyelocytic Leukemia Nuclear Body Components and Biochemical Parameters in Sera of Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by immune-mediated destruction of intrahepatic bile ducts and the presence of specific antibodies. The aim of the study was to examine the diagnostic significance of antibodies against promyelocytic leukemia nuclear body (PML NB) components such as Sp100, Sp140, and PML in a cohort of PBC patients and compare the results with biochemical and histological parameters. Serum samples were collected from 93 PBC patients. Anti-Sp100 and anti-PML antibodies were assessed using commercially available kits, anti-Sp140 using developed “in-house” ELISA test. Anti-Sp140, anti-Sp100, and anti-PML antibodies were present in 25 (27%), 37 (40%), and 29 (31%) PBC patients, respectively. Anti-PML NB positive patients also showed increased concentration of bilirubin and alkaline phosphatase (p < 0.05). In the group with the presence of at least two types of these antibodies, more frequent deaths or transplantations were observed. A correlation between the presence of antibodies and histological grade (OR = 2.55 p = 0.039) was established. Patients with bilirubin > 1.1 mg/dL at the time of diagnosis had a significantly shorter time of survival than patients with bilirubin ≤ 1.1 mg/dL (HR 5.7; 95% C.I., 2.7, 12.3; p < 0.001). Our data confirm very high specificity of anti-PML NB antibodies, which can expand the laboratory diagnostic capabilities of PBC. We found an association between positive reactivity of autoantibodies directed against components of PML nuclear bodies and higher concentrations of bilirubin and alkaline phosphatase, but the main prognostic marker of survival remains serum bilirubin

Resolving the role of podoplanin in the motility of papillary thyroid carcinoma-derived cells using RNA sequencing

The intracellular level of podoplanin (PDPN), a transmembrane protein of still unclear function, is frequently altered in metastatic tumors. High expression of PDPN is frequently observed in papillary thyroid cancer (PTC) specimens. Similarly, PTC-derived cell lines (BCPAP and TPC1, harboring the BRAF V600E mutation and RET/PTC1 fusion, respectively), also present enhanced PDPN yield. We previously reported that depletion of PDPN impairs migration of TPC1 cells, but augments metastasis of BCPAP cells. Interestingly, this phenomenon stays in contrast to the migratory pattern observed for wild-type cells, where TPC1 exhibited higher motility than BCPAP cells. Here, we aimed to elucidate the potential role of PDPN in regulation of molecular mechanisms leading to the diverse metastatic features of the studied PTC-derived cells. We consider that this phenomenon may be caused by alternative regulation of signaling pathways due to the presence of the mutated BRAF allele or RET/PTC1 fusion. The high-throughput RNA sequencing (RNA-seq) technique was used to uncover the genes and signaling pathways affected in wild-type and PDPN-depleted TPC1 and BCPAP cells. We found that changes in the expression of various factors of signaling pathways, like RHOA and RAC1 GTPases and their regulators, are linked with both high PDPN levels and presence of the BRAF V600E mutation. We imply that the suppressed motility of wild-type BCPAP cells results from overactivation of RHOA through natively high PDPN expression. This process is accompanied by inhibition of the PI3K kinase and consequently RAC1, due to overactivation of RAS-mediated signaling and the PTEN regulator

dnaX36 Mutator of Escherichia coli: Effects of the τ Subunit of the DNA Polymerase III Holoenzyme on Chromosomal DNA Replication Fidelity ▿

The Escherichia coli dnaX36 mutant displays a mutator effect, reflecting a fidelity function of the dnaX-encoded τ subunit of the DNA polymerase III (Pol III) holoenzyme. We have shown that this fidelity function (i) applies to both leading- and lagging-strand synthesis, (ii) is independent of Pol IV, and (iii) is limited by Pol II