Stimulation of MCM helicase activity by a Cdc6 protein in the archaeon Thermoplasma acidophilum

Replicative DNA helicases are ring-shaped hexamers that play an essential role in chromosomal DNA replication. They unwind the two strands of the duplex DNA and provide the single-stranded (ss) DNA substrate for the polymerase. The minichromosome maintenance (MCM) proteins are thought to function as the replicative helicases in eukarya and archaea. The proteins of only a few archaeal organisms have been studied and revealed that although all have similar amino acid sequences and overall structures they differ in their biochemical properties. In this report the biochemical properties of the MCM protein from the archaeon Thermoplasma acidophilum is described. The enzyme has weak helicase activity on a substrate containing only a 3′-ssDNA overhang region and the protein requires a forked DNA structure for efficient helicase activity. It was also found that the helicase activity is stimulated by one of the two T.acidophilum Cdc6 homologues. This is an interesting observation as it is in sharp contrast to observations made with MCM and Cdc6 homologues from other archaea in which the helicase activity is inhibited when bound to Cdc6.publishedVersio

A proof‐of‐concept pilot randomized comparative trial of brief Internet‐based compassionate mind training and cognitive‐behavioral therapy for perinatal and intending to become pregnant women

Depression is a prevalent and costly mental health problem that affects women as well as their larger communities, with substantial impacts on mother and infant during childbearing years. Face‐to‐face care has not adequately addressed this global concern due to difficulties in scaling these resources. Internet interventions, which can provide psychological tools to those lacking adequate access, show promise in filling this void. We conducted a 2‐condition proof‐of‐concept pilot randomized trial comparing brief Internet‐based cognitive behavioural therapy (CBT) and brief Internet‐based compassionate mind training (CMT) for women who are currently pregnant, became pregnant within the last year, and intend to become pregnant in the future. We found that, although CMT and CBT demonstrated near equivalence in improving affect, self‐reassurance, self‐criticism, and self‐compassion, CMT showed superiority to CBT in reducing depression and anxiety symptoms. These findings provide a compelling initial argument for the use of CMT as an avenue for addressing problems associated with negative affect. Implications, limitations, and future directions along this line of research will also be discussed.Campus Research Board at Palo Alto University Elton C and Joan R Waelde Meditation Fellowshi

Comparing brief internet-based compassionate mind training and cognitive behavioral therapy for perinatal women: Study protocol for a randomized controlled trial.

Background Depression that occurs during the perinatal period has substantial costs for both the mother and her baby. Since in-person care often falls short of meeting the global need of perinatal women, Internet interventions may function as an alternate to help women who currently lack adequate access to face-to-face psychological resources. However, at present there are insufficient empirically supported Internet-based resources for perinatal women.N/

Malignancy risk analysis in patients with inadequate fine needle aspiration cytology (FNAC) of the thyroid

Background Thyroid fine needle aspiration cytology (FNAC) is the standard diagnostic modality for thyroid nodules. However, it has limitations among which is the incidence of non-diagnostic results (Thy1). Management of cases with repeatedly non-diagnostic FNAC ranges from simple observation to surgical intervention. We aim to evaluate the incidence of malignancy in non-diagnostic FNAC, and the success rate of repeated FNAC. We also aim to evaluate risk factors for malignancy in patients with non-diagnostic FNAC. Materials and Methods Retrospective analyses of consecutive cases with thyroid non diagnostic FNAC results were included. Results Out of total 1657 thyroid FNAC done during the study period, there were 264 (15.9%) non-diagnostic FNAC on the first attempt. On repeating those, the rate of a non-diagnostic result on second FNAC was 61.8% and on third FNAC was 47.2%. The overall malignancy rate in Thy1 FNAC was 4.5% (42% papillary, 42% follicular and 8% anaplastic), and the yield of malignancy decreased considerably with successive non-diagnostic FNAC. Ultrasound guidance by an experienced head neck radiologist produced the lowest non-diagnostic rate (38%) on repetition compared to US guidance by a generalist radiologist (65%) and by non US guidance (90%). Conclusions There is a low risk of malignancy in patients with a non-diagnostic FNAC result, commensurate to the risk of any nodule. The yield of malignancy decreased considerably with successive non-diagnostic FNAC

Vaccinia Virus G8R Protein: A Structural Ortholog of Proliferating Cell Nuclear Antigen (PCNA)

BACKGROUND: Eukaryotic DNA replication involves the synthesis of both a DNA leading and lagging strand, the latter requiring several additional proteins including flap endonuclease (FEN-1) and proliferating cell nuclear antigen (PCNA) in order to remove RNA primers used in the synthesis of Okazaki fragments. Poxviruses are complex viruses (dsDNA genomes) that infect eukaryotes, but surprisingly little is known about the process of DNA replication. Given our previous results that the vaccinia virus (VACV) G5R protein may be structurally similar to a FEN-1-like protein and a recent finding that poxviruses encode a primase function, we undertook a series of in silico analyses to identify whether VACV also encodes a PCNA-like protein. RESULTS: An InterProScan of all VACV proteins using the JIPS software package was used to identify any PCNA-like proteins. The VACV G8R protein was identified as the only vaccinia protein that contained a PCNA-like sliding clamp motif. The VACV G8R protein plays a role in poxvirus late transcription and is known to interact with several other poxvirus proteins including itself. The secondary and tertiary structure of the VACV G8R protein was predicted and compared to the secondary and tertiary structure of both human and yeast PCNA proteins, and a high degree of similarity between all three proteins was noted. CONCLUSIONS: The structure of the VACV G8R protein is predicted to closely resemble the eukaryotic PCNA protein; it possesses several other features including a conserved ubiquitylation and SUMOylation site that suggest that, like its counterpart in T4 bacteriophage (gp45), it may function as a sliding clamp ushering transcription factors to RNA polymerase during late transcription

MCM2 - a promising marker for premalignant lesions of the lung: a cohort study

BACKGROUND: Because cells progressing to cancer must proliferate, marker proteins specific to proliferating cells may permit detection of premalignant lesions. Here we compared the sensitivities of a classic proliferation marker, Ki-67, with a new proliferation marker, MCM2, in 41 bronchial biopsy specimens representing normal mucosa, metaplasia, dysplasia, and carcinoma in situ. METHODS: Parallel sections were stained with antibodies against MCM2 and Ki-67, and the frequencies of staining were independently measured by two investigators. Differences were evaluated statistically using the two-sided correlated samples t-test and Wilcoxon rank sum test. RESULTS: For each of the 41 specimens, the average frequency of staining by anti-MCM2 (39%) was significantly (p < 0.001) greater than by anti-Ki-67 (16%). In metaplastic lesions anti-MCM2 frequently detected cells near the epithelial surface, while anti-Ki-67 did not. CONCLUSIONS: We conclude that MCM2 is detectable in 2-3 times more proliferating premalignant lung cells than is Ki-67. The promise of MCM2 as a sensitive marker for premalignant lung cells is enhanced by the fact that it is present in cells at the surface of metaplastic lung lesions, which are more likely to be exfoliated into sputum. Future studies will determine if use of anti-MCM2 makes possible sufficiently early detection to significantly enhance lung cancer survival rates

Comprehensive In&nbsp;Vivo Interrogation Reveals Phenotypic Impact of Human Enhancer Variants

Establishing causal links between non-coding variants and human phenotypes is an increasing challenge. Here, we introduce a high-throughput mouse reporter assay for assessing the pathogenic potential of human enhancer variants in&nbsp;vivo and examine nearly a thousand variants in an enhancer repeatedly linked to polydactyly. We show that 71% of all rare non-coding variants previously proposed as causal lead to reporter gene expression in a pattern consistent with their pathogenic role. Variants observed to alter enhancer activity were further confirmed to cause polydactyly in knockin mice. We also used combinatorial and single-nucleotide mutagenesis to evaluate the in&nbsp;vivo impact of mutations affecting all positions of the enhancer and identified additional functional substitutions, including potentially pathogenic variants hitherto not observed in humans. Our&nbsp;results uncover the functional consequences of hundreds of mutations in a phenotype-associated enhancer and establish a widely applicable strategy for systematic in&nbsp;vivo evaluation of human enhancer variants

Extremophiles in a changing world

Extremophiles and their products have been a major focus of research interest for over 40 years. Through this period, studies of these organisms have contributed hugely to many aspects of the fundamental and applied sciences, and to wider and more philosophical issues such as the origins of life and astrobiology. Our understanding of the cellular adaptations to extreme conditions (such as acid, temperature, pressure and more), of the mechanisms underpinning the stability of macromolecules, and of the subtleties, complexities and limits of fundamental biochemical processes has been informed by research on extremophiles. Extremophiles have also contributed numerous products and processes to the many fields of biotechnology, from diagnostics to bioremediation. Yet, after 40 years of dedicated research, there remains much to be discovered in this field. Fortunately, extremophiles remain an active and vibrant area of research. In the third decade of the twenty-first century, with decreasing global resources and a steadily increasing human population, the world’s attention has turned with increasing urgency to issues of sustainability. These global concerns were encapsulated and formalized by the United Nations with the adoption of the 2030 Agenda for Sustainable Development and the presentation of the seventeen Sustainable Development Goals (SDGs) in 2015. In the run-up to 2030, we consider the contributions that extremophiles have made, and will in the future make, to the SDGs.Open access funding provided by University of Pretoria.http://link.springer.com/journal/792hj2024BiochemistryGeneticsMicrobiology and Plant PathologySDG-03:Good heatlh and well-beingSDG-07:Affordable and clean energySDG-09: Industry, innovation and infrastructureSDG-12:Responsible consumption and productionSDG-14:Life below waterSDG-15:Life on lan