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Objective: To study the relationship between tibial plateau retroversion and medial meniscus injury, and further discuss and explore the abnormal anatomical factors. Methods: 36 patients who underwent knee surgery in overseas Chinese hospital from 2011 to 2022 were randomly selected and divided into groups A and B. Group A (28 cases) had definite medial meniscus injury, while group B (8 cases) had no medial meniscus injury and underwent other operations. All medial meniscus injuries met the diagnostic criteria and could be observed under arthroscopy. The tibial plateau caster angle (PTS) was measured on MRI, and the statistical significance was determined by two independent sample t-test and chi square test. The variables with statistical significance were analyzed by binary logistic regression. Finally, the independent risk factors of medial meniscus injury were determined, and the 0r value was calculated. P value 0.05). The main tear sites of medial meniscus were posterior horn tear (57,14%) and body tear (14.28%), and the tear types were complex tear (32.1%) and horizontal tear (21.4%). The average PTS of group A (8.69 °) was significantly higher than that of group B (6.22 °) (p

Background: The peculiarity and the lack of clinical studies of dual primary lung cancer (DPLC) led to limited knowledge about its clinical characteristics and prognosis. The current study performed a retrospective analysis and established a prognostic nomogram to assess the prognostic factors and clinical characteristics of DPLC.Methods: A total of 1419 DPLC patients with pathological confirmation from SEER were selected and analyzed by univariate and multivariable Cox regression analyses. The independent prognostic factors were included to establish a nomogram. The accuracy and reliability of prognostic model were evaluated by C-indexes, calibration plots, receiver operating characteristic (ROC) curves, decision curve analyses (DCA) and integrated discrimination improvement (IDI) scores. Chi-square test was used to assess the differences between DPLC and single primary lung cancer (SPLC) or synchronous DPLC (sDPLC) and metachronous DPLC (mDPLC).Results: Cox regression analysis showed that age, sex, histological type, stage, LN metastasis, surgery, chemotherapy were independent prognostic factors, we included these factors to establish a prognostic model. In the training cohort, the C-index was 0.690, and the area under curves (AUC) of 3- and 5-year survival time were 0.720 and 0.723. The calibration plots in training cohort and validation cohort were in excellent agreement. DCA and IDI showed that the predictive effect of the novel prognostic model was better than the model based on 8th AJCC TNM system. Chi-square test indicated that DPLC and SPLC had statistical differences on pathological and clinical features.Conclusions: The clinical and pathological characteristics of DPLC were different from the SPLC. The nomogram based on significant factors could provide accurate and individualized survival predictions for DPLC.

Background Lung cancer remains the leading cause of cancer death globally. In 2015, the cancer classification guidelines of the World Health Organization were updated. The term “invasive mucinous adenocarcinoma (IMA)” aroused people’s attention, while the clinicopathological factors that may influence survival were unclear. Methods Data of IMA patients was downloaded from SEER database. Kaplan-Meier methods and log-rank tests were used to compare the differences in OS and LCSS. The nomogram was developed based on the result of the multivariable analysis. The discrimination and accuracy were tested by Harrell’s concordance index (C-index), receiver operating characteristic (ROC) curve, calibration curve and decision curve analyses (DCA). Integrated discrimination improvement (IDI) index was used to evaluate the clinical efficacy. Results According to multivariate analysis, the prognosis of IMAs was associated with age, differentiation grade, TNM stage and treatments. Surgery might be the only way that would improve survival. Area under the curve (AUC) of the training cohort was 0.834and 0.830 for3-and 5-year OS, respectively. AUC for 3-and 5-year LCSS were separately 0.839 and 0.839. The new model was then evaluated by calibration curve, DCA and IDI index. Conclusion Based on this study, prognosis of IMAs was systematically reviewed, and a new nomogram was developed and validated. This model helps us understand IMA in depth and provides new ideas for IMA treatment.

The second messenger cyclic diguanylate (c-di-GMP) plays a prominent role in regulating flagellum-dependent motility in the single-flagellated pathogenic bacterium Pseudomonas aeruginosa. The c-di-GMP–mediated signaling pathways and mechanisms that control flagellar output remain to be fully unveiled. Studying surface-tethered and free-swimming P. aeruginosa PAO1 cells, we found that the overexpression of an exogenous diguanylate cyclase (DGC) raises the global cellular c-di-GMP concentration and thereby inhibits flagellar motor switching and decreases motor speed, reducing swimming speed and reversal frequency, respectively. We noted that the inhibiting effect of c-di-GMP on flagellar motor switching, but not motor speed, is exerted through the c-di-GMP–binding adaptor protein MapZ and associated chemotactic pathways. Among the 22 putative c-di-GMP phosphodiesterases, we found that three of them (DipA, NbdA, and RbdA) can significantly inhibit flagellar motor switching and swimming directional reversal in a MapZ-dependent manner. These results disclose a network of c-di-GMP–signaling proteins that regulate chemotactic responses and flagellar motor switching in P. aeruginosa and establish MapZ as a key signaling hub that integrates inputs from different c-di-GMP–signaling pathways to control flagellar output and bacterial motility. We rationalized these experimental findings by invoking a model that postulates the regulation of flagellar motor switching by subcellular c-di-GMP pools.

Stem cell fate specification is known to be regulated by mechanical cues such as cell–cell interaction and the rigidity of the extracellular matrix (ECM). At present, spheroid cultures of stem cell...

Additional file 1: Figure S1. Flow sheet of eligible patients included in the study. Figure S2. OS for IMA patients stratified by (A) Race, p = 0.772; (B) Marital status, p = 0.226. Figure S3. LCSS for IMA patients stratified by (A) Race, p = 0.959; (B) Marital status, p = 0.267. Figure S4. (A. B) ROC curves for 3- and 5-year OS based on the validation cohort data. The AUC was 0.813 and 0.840, respectively; (C. D) ROC curves for 3- and 5-year LCSS. The AUC was 0.836 and 0.857, respectively. Figure S5. (A. B) Calibration plots for 3- and 5-year OS in the validation cohort; (C. D) Calibration plots for 3- and 5-year LCSS in the validation cohort. Figure S6. Frequency of IMAs in SEER database between 2000 and 2015.

Additional file 2: Table S1. Characteristics of the training and validation cohort.

Studying the swimming behaviour of bacteria in 3 dimensions (3D) allows us to understand critical biological processes, such as biofilm formation. It is still unclear how near wall swimming behaviour may regulate the initial attachment and biofilm formation. It is challenging to address this as visualizing the movement of bacteria with reasonable spatial and temporal resolution in a high-throughput manner is technically difficult. Here, we compared the near wall (vertical) swimming behaviour of P. aeruginosa (PAO1) and its mutants ΔdipA (reduced in swarming motility and increased in biofilm formation) and ΔfimX (deficient in twitching motility and reduced in biofilm formation) using our new imaging technique based on light sheet microscopy. We found that P. aeruginosa (PAO1) increases its speed and changes its swimming angle drastically when it gets closer to a wall. In contrast, ΔdipA mutant moves toward the wall with steady speed without changing of swimming angle. The near wall behavior of ΔdipA allows it to be more effective to interact with the wall or wall-attached cells, thus leading to more capture events and a larger biofilm volume during initial attachment when compared with PAO1. Furthermore, we found that ΔfimX has a similar near wall swimming behavior as PAO1, however, it has a higher dispersal frequency and smaller biofilm formation when compared with PAO1 which can be explained by its poor twitching motility. Together, we propose that near wall swimming behavior of P. aeruginosa plays an important role in the regulation of initial attachment and biofilm formation.ImportanceBacterial biofilm is a community of bacteria on surfaces which leads to serious problems in medical devices, food industry, and aquaculture. The initial attachment and subsequent microcolony formation play critical roles in bacterial biofilm formation. However, it is unclear how the initial attachment is regulated, in particular, on a vertical surface. To study this, we have developed a novel imaging technique based on light sheet microscopy, which overcame the limitations of other imaging techniques, to understand how 3D bacterial motility near a wall may regulate initial attachment during biofilm formation. Using our technique, we discovered that near wall swimming behavior of the bacteria, P. aeruginosa, plays an important role in the regulation of biofilm formation during initial attachment.

Objectives The rarity of atypical carcinoid (AC) of lung and the lack of prospective clinical trials lead to limited knowledge of its biology, treatment information and prognosis. The current study analyzed AC patients from the Surveillance, Epidemiology, and End Results (SEER) database to better understand the clinical characteristics of this disease and build a prognostic nomogram for clinical practice. Materials and methods A total of 507 AC patients with pathological confirmation from SEER database were performed with univariate Cox regression analyses for both overall survival (OS) and lung cancer specific survival (LCSS) analyses. Of the 507 observations, 464 were used in the multivariable Cox proportional hazards model as training cohort of new nomogram. A new nomogram was constructed based on the training cohort and validated by an external validation cohort to predict the 3-, 5- and 10-year OS of ACs. The accuracy and clinical practicability were separately tested by Harrell's C-indexes, calibration plots and decision curve analyses (DCA). Results Lobectomy and segmental resection were found to be protective factors for AC patients. Age, primary tumor size, N stage, M stage, surgery and regional lymph nodes examination were shown as significant prognostic factors in Cox regression analyses and included in the nomogram as predictors. The C-index in the training cohort for 3-, 5-, and 10-year OS were 0.722, 0.737 and 0.712, respectively. The internal and external calibration plots for predictions of the 3-, 5-, and 10-year OS were in excellent agreement. An online webserver was built based on the proposed nomogram for convenient clinical use. Conclusion AC patients with lobectomy or segmental resection tended to have better OS and LCSS. A nomogram was constructed and validated to predict the OS for AC patients and to provide accurate and individualized survival predictions.

The topography of the extracellular substrate provides physical cues to elicit specific downstream biophysical and biochemical effects in cells. An example of such a topographical substrate is periodic gratings, where the dimensions of the periodic gratings influence cell morphology and directs cell differentiation. We first develop a novel sample preparation technique using Spurr’s resin to allow for cross-sectional transmission electron microscopy imaging of cells on grating grooves, and observed that the plasma membrane on the basal surface of these cells can deform and bend into grooves between the gratings. We postulate that such membrane bending is an important first step in eliciting downstream effects. Thus, we use a combination of image analysis and mathematical modeling to explain the extent of bending of basal membrane into grooves. We show that the extent to which the basal membrane bends into grooves depends on both groove width and angle of the grating ridge. Our model predicts that the basal membrane will bend into grooves when they are wider than 1.9 µm in width. The existence of such a threshold may provide an explanation for how the width of periodic gratings may bring about cellular downstream effects, such as cell proliferation or differentiation.

The bacterial second messenger cyclic di-GMP (c-di-GMP) has emerged as a prominent mediator of bacterial physiology, motility, and pathogenicity. c-di-GMP often regulates the function of its protein targets through a unique mechanism that involves a discrete PilZ adaptor protein. However, the molecular mechanism for PilZ protein–mediated protein regulation is unclear. Here, we present the structure of the PilZ adaptor protein MapZ cocrystallized in complex with c-di-GMP and its protein target CheR1, a chemotaxis-regulating methyltransferase in Pseudomonas aeruginosa. This cocrystal structure, together with the structure of free CheR1, revealed that the binding of c-di-GMP induces dramatic structural changes in MapZ that are crucial for CheR1 binding. Importantly, we found that restructuring and repositioning of two C-terminal helices enable MapZ to disrupt the CheR1 active site by dislodging a structural domain. The crystallographic observations are reinforced by protein–protein binding and single cell–based flagellar motor switching analyses. Our studies further suggest that the regulation of chemotaxis by c-di-GMP through MapZ orthologs/homologs is widespread in proteobacteria and that the use of allosterically regulated C-terminal motifs could be a common mechanism for PilZ adaptor proteins. Together, the findings provide detailed structural insights into how c-di-GMP controls the activity of an enzyme target indirectly through a PilZ adaptor protein. ASTAR (Agency for Sci., Tech. and Research, S’pore) MOE (Min. of Education, S’pore) Published version

Phototunable supersoft elastomers were prepared by photo-cross-linking molecular bottlebrushes with poly(n-butyl acrylate) (PBA) side chains. Bottlebrushes were synthesized by atom transfer radical polymerization (ATRP) and Br-chain end functionalities were replaced by photo-cross-linkable coumarin units. Photo-cross-linking and photoscission of molecular bottlebrushes resulted in tunable elastomeric behavior quantified by dynamic mechanical analysis. The cell–substrate interactions, tuned by UV-light, depended on surface morphology and softness that could be as low as several kilopascals.

The bacterial messenger cyclic diguanylate monophosphate (c-di-GMP) binds to various effectors, the most common of which are single-domain PilZ proteins. These c-di-GMP effectors control various cellular functions and multicellular behaviors at the transcriptional or posttranslational level. We found that MapZ (methyltransferase-associated PilZ; formerly known as PA4608), a single-domain PilZ protein from the opportunistic pathogen Pseudomonas aeruginosa, directly interacted with the methyltransferase CheR1 and that this interaction was enhanced by c-di-GMP. In vitro assays indicated that, in the presence of c-di-GMP, MapZ inhibited CheR1 from methylating the chemoreceptor PctA, which would be expected to increase its affinity for chemoattractants and promote chemotaxis. MapZ localized to the poles of P. aeruginosa cells, where the flagellar motor and other chemotactic proteins, including PctA and CheR1, are also located. P. aeruginosa cells exhibit a random walk behavior by frequently switching the direction of flagellar rotation in a uniform solution. We showed that binding of c-di-GMP to MapZ decreased the frequency of flagellar motor switching and that MapZ was essential for generating the heterogeneous motility typical of P. aeruginosa cell populations and for efficient surface attachment during biofilm formation. Collectively, the studies revealed that c-di-GMP affects flagellar motor output by regulating the methylation of chemoreceptors through a single-domain PilZ adaptor protein.

Circular dorsal ruffles (CDRs) are transient actin structures which have been linked to cell motility but the exact mechanism is still unclear. CDRs appear and grow in size after cells are stimulated with growth factors, such as the platelet-derived growth factor, eventually disappearing tens of minutes after stimulation. The role of CDR formation in cell motility is investigated for NIH 3T3 fibroblasts seeded on compliant polyacrylamide substrates. We found that CDR formation increases cell migration directional persistency but did not affect the migration speed. Furthermore, an increase in the localization of lamellipodial protrusion at the cell edge in the vicinity of the CDRs was observed. Relocalization of lamellipodia occured 1 to 6 min after CDR formation at the cell edge closest to the site of CDR formation. The time lag between peak CDR formation and the peak lamellipodial protrusion is then correlated with the spatial distance between the CDR and the lamellipodia; this time scale is consistent with the diffusive time scale of cytosolic globular actin (G actin). Using green to red photoswitchable Dendra2-conjugated actin, we photoconverted CDR actin from green to red and observed the subsequent appearance of red fluorescent actin in the lamellipodia at the cell leading edge. These findings help shed light on the interconversions between mesoscopic actin structures in cell behavior.