223 research outputs found
Cdc4p, a contractile ring protein essential for cytokinesis in Schizosaccharomyces pombe, interacts with a phosphatidylinositol 4-kinase.
The proposed function of Cdc4p, an essential contractile ring protein in Schizosaccharomyces pombe, is that of a myosin essential light chain. However, five conditionally lethal cdc4 alleles exhibit complementation in diploids. Such interallelic complementation is not readily explained if the sole function of Cdc4p is that of a myosin essential light chain. Complementation of cdc4 alleles could occur only if different mutant forms can assemble into an active oligomeric complex or if Cdc4p has more than one essential function. To search for other proteins that may interact with Cdc4p, we performed a two-hybrid screen and identified two such candidates: one similar to Saccharomyces cerevisiae Vps27p and the other a putative phosphatidylinositol (PI) 4-kinase. Binding of Cdc4p to the latter and to myosin heavy chain (Myo2p) was confirmed by immunosorbent assays. Deletion studies demonstrated interaction between the Cdc4p C-terminal domain and the PI 4-kinase C-terminal domain. Furthermore, interaction was abolished by the Cdc4p C-terminal domain point mutation, Gly107 to Ser. This allele also causes failure of cytokinesis. Ectopic expression of the PI 4-kinase C-terminal domain caused cytokinesis defects that were most extreme in cells carrying the G107S allele. We suggest that Cdc4p plays multiple roles in cytokinesis and that interaction with a PI 4-kinase may be important for contractile ring assembly and/or function
Evaluation of Bone Remodeling in Hemodialysis Patients: Serum Biochemistry, Circulating Cytokines and Bone Histomorphometry
BACKGROUND: To optimize the noninvasive evaluation of bone remodeling, we evaluated, besides routine serum markers, serum levels of several cytokines involved in bone turnover.
METHODS: A transiliac bone biopsy was performed in 47 hemodialysis patients. Serum levels of intact parathyroid hormone (iPTH; 1-84), total alkaline phosphatases (tAP), calcium, phosphate and aluminum (Al) were measured. Circulating levels of interleukin-6 (IL-6), IL-1 receptor antagonist (IL-1Ra) and soluble IL-6 receptor (sIL-6r) were determined using ELISA. Circulating IL-1beta, IL-6, IL-8, IL-10, IL-12p70 and tumor necrosis factor-alpha (TNF-alpha) were simultaneously quantified by flow cytometric immunoassay.
RESULTS: Patients with low/normal bone formation rate (L/N-BFR) had significantly lower serum iPTH (p300 pg/mL in association with tAP >120 U/L showed low sensitivity (58.8%) and low negative predictive value (44.0%) for the diagnosis of high BFR disease. An iPTH <300 pg/mL in association with normal or low tAP, <120 U/L, was associated with low sensitivity (66.7%) but high specificity (97.1%) for the diagnosis of L/N-BFR. Serum IL-1, IL-6, IL-12p70 and TNF-alpha were positively correlated with BFR, serum IL1-Ra and IL-10 with bone area, and by multiple regression analysis, tAP and IL-6 were independently predictive of BFR.
CONCLUSIONS: Significant associations were found between several circulating cytokines and bone histomorphometry in dialysis patients. The usefulness of these determinations in the noninvasive evaluation of bone remodeling needs to be confirmed in larger dialysis populations
Accommodating heterogeneous missing data patterns for prostate cancer risk prediction
Objective: We compared six commonly used logistic regression methods for
accommodating missing risk factor data from multiple heterogeneous cohorts, in
which some cohorts do not collect some risk factors at all, and developed an
online risk prediction tool that accommodates missing risk factors from the
end-user. Study Design and Setting: Ten North American and European cohorts
from the Prostate Biopsy Collaborative Group (PBCG) were used for fitting a
risk prediction tool for clinically significant prostate cancer, defined as
Gleason grade group greater or equal 2 on standard TRUS prostate biopsy. One
large European PBCG cohort was withheld for external validation, where
calibration-in-the-large (CIL), calibration curves, and
area-underneath-the-receiver-operating characteristic curve (AUC) were
evaluated. Ten-fold leave-one-cohort-internal validation further validated the
optimal missing data approach. Results: Among 12,703 biopsies from 10 training
cohorts, 3,597 (28%) had clinically significant prostate cancer, compared to
1,757 of 5,540 (32%) in the external validation cohort. In external validation,
the available cases method that pooled individual patient data containing all
risk factors input by an end-user had best CIL, under-predicting risks as
percentages by 2.9% on average, and obtained an AUC of 75.7%. Imputation had
the worst CIL (-13.3%). The available cases method was further validated as
optimal in internal cross-validation and thus used for development of an online
risk tool. For end-users of the risk tool, two risk factors were mandatory:
serum prostate-specific antigen (PSA) and age, and ten were optional: digital
rectal exam, prostate volume, prior negative biopsy,
5-alpha-reductase-inhibitor use, prior PSA screen, African ancestry, Hispanic
ethnicity, first-degree prostate-, breast-, and second-degree prostate-cancer
family history
To defer or not to defer? A German longitudinal multicentric assessment of clinical practice in urology during the COVID-19 pandemic
Introduction After the outbreak of COVID-19 unprecedented changes in the healthcare systems worldwide were necessary resulting in a reduction of urological capacities with postponements of consultations and surgeries. Material and methods An email was sent to 66 urological hospitals with focus on robotic surgery (RS) including a link to a questionnaire (e.g. bed/staff capacity, surgical caseload, protection measures during RS) that covered three time points: a representative baseline week prior to COVID-19, the week of March 16th-22nd and April 20th-26th 2020. The results were evaluated using descriptive analyses. Results 27 out of 66 questionnaires were analyzed (response rate: 41%). We found a decrease of 11% in hospital beds and 25% in OR capacity with equal reductions for endourological, open and robotic procedures. Primary surgical treatment of urolithiasis and benign prostate syndrome (BPS) but also of testicular and penile cancer dropped by at least 50% while the decrease of surgeries for prostate, renal and urothelial cancer (TUR-B and cystectomies) ranged from 15 to 37%. The use of personal protection equipment (PPE), screening of staff and patients and protection during RS was unevenly distributed in the different centers\u2013however, the number of COVID-19 patients and urologists did not reach double digits. Conclusion The German urological landscape has changed since the outbreak of COVID-19 with a significant shift of high priority surgeries but also continuation of elective surgical treatments. While screening and staff protection is employed heterogeneously, the number of infected German urologists stays low
Use of 16S rRNA Gene Based Clone Libraries to Assess Microbial Communities Potentially Involved in Anaerobic Methane Oxidation in a Mediterranean Cold Seep
This study provides data on the diversities of bacterial and archaeal communities in an active methane seep at the Kazan mud volcano in the deep Eastern Mediterranean sea. Layers of varying depths in the Kazan sediments were investigated in terms of (1) chemical parameters and (2) DNA-based microbial population structures. The latter was accomplished by analyzing the sequences of directly amplified 16S rRNA genes, resulting in the phylogenetic analysis of the prokaryotic communities. Sequences of organisms potentially associated with processes such as anaerobic methane oxidation and sulfate reduction were thus identified. Overall, the sediment layers revealed the presence of sequences of quite diverse bacterial and archaeal communities, which varied considerably with depth. Dominant types revealed in these communities are known as key organisms involved in the following processes: (1) anaerobic methane oxidation and sulfate reduction, (2) sulfide oxidation, and (3) a range of (aerobic) heterotrophic processes. In the communities in the lowest sediment layer sampled (22–34 cm), sulfate-reducing bacteria and archaea of the ANME-2 cluster (likely involved in anaerobic methane oxidation) were prevalent, whereas heterotrophic organisms abounded in the top sediment layer (0–6 cm). Communities in the middle layer (6–22 cm) contained organisms that could be linked to either of the aforementioned processes. We discuss how these phylogeny (sequence)-based findings can support the ongoing molecular work aimed at unraveling both the functioning and the functional diversities of the communities under study
Management of patients who opt for radical prostatectomy during the COVID‐19 pandemic: An International Accelerated Consensus Statement
BACKGROUND: Coronavirus disease-19 (COVID-19) pandemic caused delays in definitive treatment of patients with prostate cancer. Beyond the immediate delay a backlog for future patients is expected. Such delays can lead to disease progression. OBJECTIVE: We aimed to develop guidance on criteria for prioritization for surgery and reconfiguring management pathways for non-metastatic stage of prostate cancer who opt for surgical treatment. A second aim was to identify the infection prevention and control (IPC) measures to achieve low likelihood of COVID-19 hazard if radical prostatectomy was to be carried out during the outbreak and whilst the disease is endemic. DESIGN, SETTING AND PARTICIPANTS: An accelerated consensus process and systematic review. We conducted a systematic review of the evidence on COVID-19 and reviewed international guidance on prostate cancer. These were presented to an international prostate cancer expert panel (n=34) through an online meeting. The consensus process underwent three rounds of survey in total. Additions to the second- and third-round surveys were formulated based on the answers and comments from the previous rounds. OUTCOME MEASURES: Consensus opinion was defined as ≥80% agreement, which were used to reconfigure the prostate cancer pathways. RESULTS: Evidence on the delayed management of patients with prostate cancer is scarce. There was 100% agreement that prostate cancer pathways should be reconfigured and develop measures to prevent nosocomial COVID-19 for patients treated surgically. Consensus was reached on prioritization criteria of patients for surgery and management pathways for those who have delayed treatment. IPC measures to achieve a low likelihood of nosocomial COVID-19 were coined as "COVID-19 cold sites". CONCLUSION: Re-configuring management pathways for prostate cancer patients is recommended if significant delay (>3-6 months) in surgical management is unavoidable. The mapped pathways provide guidance for such patients. The IPC processes proposed provide a framework for providing radical prostatectomy within an environment with low COVID-19 risk during the outbreak or when the disease remains endemic. The broader concepts could be adapted to other indications beyond prostate cancer surgery
A four-kallikrein panel for the prediction of repeat prostate biopsy: data from the European Randomized Study of Prostate Cancer Screening in Rotterdam, Netherlands
Background: Most men with elevated levels of prostate-specific antigen (PSA) do not have prostate cancer, leading to a large number of unnecessary biopsies. A statistical model based on a panel of four kallikreins has been shown to predict the outcome of a first prostate biopsy. In this study, we apply the model to an independent data set of men with previous negative biopsy but persistently elevated PSA. Methods: The study cohort consisted of 925 men with a previous negative prostate biopsy and elevated PSA (≥3 ng ml-1), with 110 prostate cancers detected (12%). A previously published statistical model was applied, with recalibration to reflect the lower positive biopsy rates on rebiopsy. Results: The full-kallikrein panel had higher discriminative accuracy than PSA and DRE alone, with area under the curve (AUC) improving from 0.58 (95% confidence interval (CI): 0.52, 0.64) to 0.68 (95% CI: 0.62, 0.74), P<0.001, and high-grade cancer (Gleason 7) at biopsy with AUC improving from 0.76 (95% CI: 0.64, 0.89) to 0.87 (95% CI: 0.81, 0.94), P<0.003). Application of the panel to 1000 men with persistently elevated PSA after initial negative biopsy, at a 15% risk threshold would reduce the number of biopsies by 712; would miss (or delay) the diagnosis of 53 cancers, of which only 3 would be Gleason 7 and the rest Gleason 6 or less. Conclusions: Our data constitute an external validation of a previously published model. The four-kallikrein panel predicts the result of repeat prostate biopsy in men with elevated PSA while dramatically decreasing unnecessary biopsies
Additives for vaccine storage to improve thermal stability of adenoviruses from hours to months
Up to 80% of the cost of vaccination programmes is due to the cold chain problem (that is, keeping vaccines cold). Inexpensive, biocompatible additives to slow down the degradation of virus particles would address the problem. Here we propose and characterize additives that, already at very low concentrations, improve the storage time of adenovirus type 5. Anionic gold nanoparticles (10(-8)-10(-6) M) or polyethylene glycol (PEG, molecular weight similar to 8,000 Da, 10(-7)-10(-4) M) increase the half-life of a green fluorescent protein expressing adenovirus from similar to 48 h to 21 days at 37 degrees C (from 7 to >30 days at room temperature). They replicate the known stabilizing effect of sucrose, but at several orders of magnitude lower concentrations. PEG and sucrose maintained immunogenicity in vivo for viruses stored for 10 days at 37 degrees C. To achieve rational design of viral-vaccine stabilizers, our approach is aided by simplified quantitative models based on a single rate-limiting step
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