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1.
Plant Biol (Stuttg) ; 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39284019

RESUMO

Increasing ant abundance associated with climate warming has been observed in temperate ecosystems. However, how enhanced ant activity affects plant development and phenology remains unclear. In this study, individuals of a perennial forb (Potentilla tanacetifolia) during flowering with and without an ant (Proformica) nest were marked to explore the impacts of ant nests on plant growth and phenology in a temperate steppe on the Mongolian Plateau. Ant nests delayed the start and end flowering dates simultaneously and, consequently, had no effect on flowering duration. However, presence of an ant nest postponed the fruiting date of individuals. Nests further increased numbers of aborted flowers and thus decreased fruit set. These observations suggest that the delayed flowering phenology disrupted synchrony between plant reproduction and pollinators and thus reduced pollination efficiency under ant nests. Given the increasing abundance of ants with rising temperatures under climate warming, plant delayed reproductive phenology and reduced reproductive output will potentially have negative consequences for plant fitness and plant-arthropod interactions, with consequent impacts on resistance and resilience of perennial species in temperate steppes under climate change.

2.
PLoS Biol ; 22(9): e3002809, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39264987

RESUMO

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins in Toxoplasma, IMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant invasion and replication but surprisingly minor effects on motility. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and 2 other cytoskeletal IMC proteins-IMC3 and ILP1. This provides direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.


Assuntos
Membrana Celular , Proteínas de Protozoários , Toxoplasma , Toxoplasma/metabolismo , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Membrana Celular/metabolismo , Citoesqueleto/metabolismo , Humanos , Domínios Proteicos , Animais , Ligação Proteica
3.
J Virol ; : e0064024, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39329471

RESUMO

Arenaviruses exist globally and can cause hemorrhagic fever and neurological diseases, exemplified by the zoonotic pathogen lymphocytic choriomeningitis virus (LCMV). The structures of individual LCMV proteins or their fragments have been reported, but the architectural organization and the nucleocapsid assembly mechanism remain elusive. Importantly, the in situ structure of the arenavirus fusion protein complex (glycoprotein complex, GPC) as present on the virion prior to fusion, particularly with its integral stable signal peptide (SSP), has not been shown, hindering efforts such as structure-based vaccine design. Here, we have determined the in situ structure of LCMV proteins and their architectural organization in the virion by cryogenic electron tomography. The tomograms reveal the global distribution of GPC, matrix protein Z, and the contact points between the viral envelope and nucleocapsid. Subtomogram averaging yielded the in situ structure of the mature GPC with its transmembrane domain intact, revealing the GP2-SSP interface and the endodomain of GP2. The number of RNA-dependent RNA polymerase L molecules packaged within each virion varies, adding new perspectives to the infection mechanism. Together, these results delineate the structural organization of LCMV and offer new insights into its mechanism of LCMV maturation, egress, and cell entry. IMPORTANCE: The impact of COVID-19 on public health has highlighted the importance of understanding zoonotic pathogens. Lymphocytic choriomeningitis virus (LCMV) is a rodent-borne human pathogen that causes hemorrhagic fever. Herein, we describe the in situ structure of LCMV proteins and their architectural organization on the viral envelope and around the nucleocapsid. The virion structure reveals the distribution of the surface glycoprotein complex (GPC) and the contact points between the viral envelope and the underlying matrix protein, as well as the association with the nucleocapsid. The morphology and sizes of virions, as well as the number of RNA polymerase L inside each virion vary greatly, highlighting the fast-changing nature of LCMV. A comparison between the in situ GPC trimeric structure and prior ectodomain structures identifies the transmembrane and endo domains of GPC and key interactions among its subunits. The work provides new insights into LCMV assembly and informs future structure-guided vaccine design.

4.
Viruses ; 16(9)2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39339924

RESUMO

Rabies virus (RABV) is among the first recognized viruses of public health concern and has historically contributed to the development of viral vaccines. Despite these significances, the three-dimensional structure of the RABV virion remains unknown due to the challenges in isolating structurally homogenous virion samples in sufficient quantities needed for structural investigation. Here, by combining the capabilities of cryogenic electron tomography (cryoET) and microscopy (cryoEM), we determined the three-dimensional structure of the wild-type RABV virion. Tomograms of RABV virions reveal a high level of structural heterogeneity among the bullet-shaped virion particles encompassing the glycoprotein (G) trimer-decorated envelope and the nucleocapsid composed of RNA, nucleoprotein (N), and matrix protein (M). The structure of the trunk region of the virion was determined by cryoEM helical reconstruction, revealing a one-start N-RNA helix bound by a single layer of M proteins at an N:M ratio of 1. The N-M interaction differs from that in fellow rhabdovirus vesicular stomatitis virus (VSV), which features two layers of M stabilizing the N-RNA helix at an M:N ratio of 2. These differences in both M-N stoichiometry and binding allow RABV to flex its N-RNA helix more freely and point to different mechanisms of viral assembly between these two bullet-shaped rhabdoviruses.


Assuntos
Microscopia Crioeletrônica , Vírus da Raiva , Vírion , Vírus da Raiva/ultraestrutura , Vírus da Raiva/química , Vírion/ultraestrutura , Animais , RNA Viral/genética , RNA Viral/metabolismo , Tomografia com Microscopia Eletrônica , Modelos Moleculares , Nucleocapsídeo/ultraestrutura , Nucleocapsídeo/metabolismo , Nucleocapsídeo/química , Raiva/virologia , Proteínas da Matriz Viral/química , Proteínas da Matriz Viral/metabolismo , Proteínas da Matriz Viral/ultraestrutura , Proteínas da Matriz Viral/genética
5.
Res Sq ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39281863

RESUMO

Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis (Tv) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv-DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, such as TvFAP40 and TvFAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of TvFAP40 and has characteristics of a drug molecule. This first atomic model of the Tv-DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform rational design of therapeutics.

6.
Zhonghua Yi Xue Za Zhi ; 104(34): 3221-3227, 2024 Sep 03.
Artigo em Chinês | MEDLINE | ID: mdl-39193607

RESUMO

Objective: To compare the safety and short-term efficacy of robotic-assisted thoracic surgery(RATS) and video-assisted thoracoscopic surgery(VATS) in patients with non-small cell lung cancer (NSCLC). Methods: A retrospective analysis of the clinical data of 2 058 NSCLC patients who underwent RATS and VATS from January 2021 to December 2022 in Xiangya Hospital of Central South University was conducted, including 1 006 males and 1 052 females, with the age of (57.3±9.9) years. According to the surgical approach, the patients were divided into RATS group (n=1 190) and VATS group (n=868). The nearest neighbor matching method was used to perform 1∶1 propensity score matching (PSM). A comparison was made about the intraoperative conditions and postoperative complication rates between the RATS and VATS groups before and after PSM. Furthermore, after PSM, a stratified analysis was conducted based on surgical approach, separately comparing the intraoperative conditions and postoperative complication rates between the VATS and RATS groups among patients who underwent lobectomy and segmentectomy, respectively. Results: After PSM, a total of 1 692 patients were included, with 846 patients in both the VATS and RATS groups. After stratification based on surgical approach, there were 503 patients in the RATS group and 548 patients in the VATS group for lobectomy, and 338 patients in the RATS group and 298 patients in the VATS group for segmentectomy. Before PSM, statistically significant differences were observed between the RATS and VATS groups in terms of intraoperative conversion to open thoracotomy, number of lymph node dissection/sampling stations, extubation time, total length of hospital stay, and total hospitalization costs (all P<0.001). After PSM, compared with the VATS group, the RATS group had a lower intraoperative conversion rate to open surgery [1.2% (10/846) vs 5.1% (43/846)], less intraoperative blood loss [(73.6±77.4) ml vs (112.6±239.3) ml], a greater number of sampled/dissected lymph node stations [(4.8±2.0) vs (3.7±1.8)], a shorter duration of drainage tube placement [(3.6±2.7) d vs (4.1±2.5) d], and a higher postoperative drainage volume [(273.9±183.0) ml vs (256.5±168.7) ml] (all P<0.001). There was no statistically significant difference in the incidence of postoperative complications between the two groups (P=0.108). The results of the surgical stratification analysis showed statistically significant differences between the two groups in terms of intraoperative blood loss, number of lymph node dissection/sampling stations, extubation time, and total hospitalization costs for both lobectomy and segmentectomy surgeries (all P<0.001). In lobectomy surgeries, the RATS group had a lower rate of intraoperative conversion to open thoracotomy than that of VATS group [1.6% (8/503) vs 7.7% (42/548), P<0.001]. In segmentectomy surgeries, the RATS group had more postoperative drainage volume than that of VATS group [(249.8±151.5) ml vs (218.7±132.9) ml, P=0.023]. There was no statistically significant difference in the incidence of surgical complications between the two groups for both lobectomy and segmentectomy surgeries (both P>0.05). Conclusion: In the surgical management of NSCLC, RATS offers more advantages over VATS in reducing conversion rates to open surgery, minimizing perioperative adverse events, and facilitating faster patient recovery postoperatively.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Pneumonectomia , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Robóticos , Cirurgia Torácica Vídeoassistida , Masculino , Neoplasias Pulmonares/cirurgia , Humanos , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Pessoa de Meia-Idade , Feminino , Cirurgia Torácica Vídeoassistida/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Estudos Retrospectivos , Pneumonectomia/métodos , Resultado do Tratamento , Pontuação de Propensão
7.
Nat Commun ; 15(1): 7057, 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39152109

RESUMO

Due to envelope differences between Gram-positive and Gram-negative bacteria, engineering precision bactericidal contractile nanomachines requires atomic-level understanding of their structures; however, only those killing Gram-negative bacteria are currently known. Here, we report the atomic structures of an engineered diffocin, a contractile syringe-like molecular machine that kills the Gram-positive bacterium Clostridioides difficile. Captured in one pre-contraction and two post-contraction states, each structure fashions six proteins in the bacteria-targeting baseplate, two proteins in the energy-storing trunk, and a collar linking the sheath with the membrane-penetrating tube. Compared to contractile machines targeting Gram-negative bacteria, major differences reside in the baseplate and contraction magnitude, consistent with target envelope differences. The multifunctional hub-hydrolase protein connects the tube and baseplate and is positioned to degrade peptidoglycan during penetration. The full-length tape measure protein forms a coiled-coil helix bundle homotrimer spanning the entire diffocin. Our study offers mechanical insights and principles for designing potent protein-based precision antibiotics.


Assuntos
Antibacterianos , Bacteriocinas , Clostridioides difficile , Bacteriocinas/química , Bacteriocinas/metabolismo , Bacteriocinas/farmacologia , Clostridioides difficile/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/química , Modelos Moleculares , Bactérias Gram-Positivas/efeitos dos fármacos , Peptidoglicano/metabolismo , Peptidoglicano/química , Cristalografia por Raios X
8.
J Dairy Sci ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-39004121

RESUMO

Reduced liver function, increased oxidative stress, and inflammation in early lactation negatively impact lactation performance and health of fresh cows. Previous findings from our group demonstrated that branched-chain amino acids (BCAA) infusion improved lactation performance and branched-chain ketoacids (BCKA) infusion decreased liver triglyceride (TG) in fresh cows. The objectives of this study were to determine the effect of BCAA and BCKA on blood and liver biomarkers of liver function, oxidative stress, and inflammation as well as expression of genes regulating inflammation and antioxidant metabolism in the liver. Thirty multiparous Holstein cows were used in a randomized block design receiving continuous abomasal infusion for 21 d after parturition. Treatments (10 cows each) were control (CON), cows abomasally infused with 0.9% saline; BCA, cows abomasally infused with BCAA (67 g valine, 50 g leucine, and 34 g isoleucine); and BCK, cows abomasally infused with BCKA (77 g ketovaline, 57 g ketoleucine, and 39 g ketoisoleucine). All cows were randomly assigned to treatments after parturition and received the same diet throughout the experimental period. Blood was collected at 3, 7, 14, and 21 d postpartum for liver function, oxidative stress, and inflammation biomarker profiling. Liver was also harvested on 7, 14, and 21 d postpartum for quantification of glutathione, protein carbonylation, and expression of genes. ANOVA was conducted for all data using PROC GLIMMIX in SAS. No treatment differences were observed for liver function biomarkers (bilirubin, gamma-glutamyl transferase, and aspartate aminotransferase). Cows receiving BCAA had lower blood NO2- and NO3- concentrations compared with CON. A tendency for lower advanced oxidized protein products was also observed in BCA cows compared with CON. Additionally, on d 7, BCA cows had lower protein carbonylation in the liver compared with CON. In contrast, BCK cows had higher plasma thiol and albumin, as well as liver reduced and total glutathione compared with CON cows. Compared with CON, BCK cows had higher expression glutathione reductase in the liver. Overall, these results suggest favorable alterations in oxidative stress and inflammation status in fresh cows receiving BCAA or BCKA infusion during the first 3 weeks of lactation, which likely contributed to previously-observed changes in lactation performance and liver TG concentrations. Future work is required to evaluate the interrelated metabolism of BCAA and BCKA to better understand their effects on oxidative and immune metabolism.

9.
bioRxiv ; 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-39026688

RESUMO

Many protein-protein interactions behave differently in biochemically purified forms as compared to their in vivo states. As such, determining native protein structures may elucidate structural states previously unknown for even well-characterized proteins. Here we apply the bottom-up structural proteomics method, cryoID , toward a model methanogenic archaeon. While they are keystone organisms in the global carbon cycle and active members of the human microbiome, there is a general lack of characterization of methanogen enzyme structure and function. Through the cryoID approach, we successfully reconstructed and identified the native Methanosarcina acetivorans pyridoxal 5'-phosphate (PLP) synthase (PdxS) complex directly from cryogenic electron microscopy (cryoEM) images of fractionated cellular lysate. We found that the native PdxS complex exists as a homo-dodecamer of PdxS subunits, and the previously proposed supracomplex containing both the synthase (PdxS) and glutaminase (PdxT) was not observed in cellular lysate. Our structure shows that the native PdxS monomer fashions a single 8α/8ß TIM-barrel domain, surrounded by seven additional helices to mediate solvent and interface contacts. A density is present at the active site in the cryoEM map and is interpreted as ribose 5-phosphate. In addition to being the first reconstruction of the PdxS enzyme from a heterogeneous cellular sample, our results reveal a departure from previously published archaeal PdxS crystal structures, lacking the 37 amino acid insertion present in these prior cases. This study demonstrates the potential of applying the cryoID workflow to capture native structural states at atomic resolution for archaeal systems, for which traditional biochemical sample preparation is nontrivial.

10.
bioRxiv ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-39026862

RESUMO

Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) are classified into the gammaherpesvirus subfamily of Herpesviridae , which stands out from its alpha- and betaherpesvirus relatives due to the tumorigenicity of its members. Although structures of human alpha- and betaherpesviruses by cryogenic electron tomography (cryoET) have been reported, reconstructions of intact human gammaherpesvirus virions remain elusive. Here, we structurally characterize extracellular virions of EBV and KSHV by deep learning-enhanced cryoET, resolving both previously known monomorphic capsid structures and previously unknown pleomorphic features beyond the capsid. Through subtomogram averaging and subsequent tomogram-guided sub-particle reconstruction, we determined the orientation of KSHV nucleocapsids from mature virions with respect to the portal to provide spatial context for the tegument within the virion. Both EBV and KSHV have an eccentric capsid position and polarized distribution of tegument. Tegument species span from the capsid to the envelope and may serve as scaffolds for tegumentation and envelopment. The envelopes of EBV and KSHV are less densely populated with glycoproteins than those of herpes simplex virus 1 and human cytomegalovirus, representative members of alpha- and betaherpesviruses, respectively. This population density of glycoproteins correlates with their relative infectivity against HEK293T cells. Also, we observed fusion protein gB trimers exist within triplet arrangements in addition to standalone complexes, which is relevant to understanding dynamic processes such as fusion pore formation. Taken together, this study reveals nuanced yet important differences in the tegument and envelope architectures among human herpesviruses and provides insights into their varied cell tropism and infection. Importance: Discovered in 1964, Epstein-Barr virus (EBV) is the first identified human oncogenic virus and the founding member of the gammaherpesvirus subfamily. In 1994, another cancer-causing virus was discovered in lesions of AIDS patients and later named Kaposi's sarcoma-associated herpesvirus (KSHV), the second human gammaherpesvirus. Despite the historical importance of EBV and KSHV, technical difficulties with isolating large quantities of these viruses and the pleiomorphic nature of their envelope and tegument layers have limited structural characterization of their virions. In this study, we employed the latest technologies in cryogenic electron microscopy (cryoEM) and tomography (cryoET) supplemented with an artificial intelligence-powered data processing software package to reconstruct 3D structures of the EBV and KSHV virions. We uncovered unique properties of the envelope glycoproteins and tegument layers of both EBV and KSHV. Comparison of these features with their non-tumorigenic counterparts provides insights into their relevance during infection.

11.
Artigo em Chinês | MEDLINE | ID: mdl-39075003

RESUMO

Objective: To investigate the relationship between ankle stability and associated muscle load around the ankle and the effect of a parachute ankle brace (PAB) on ankle inversion and associated muscle load around the ankle during landing through the simulated paratrooper semi-squat landing field experiment. Methods: In August 2021, 37 male paratroopers were randomly selected as the study objects to perform parachute landing training in the semi-squat posture on the 1.5 m and 2.0 m jump platforms with or without PAB, respectively. The coronal plane tilt angle of ankle joint and the percentage of maximum voluntary contraction (MVC%) of associated muscles around ankle joint during the process were measured and correlation analysis was conducted. And the effect of wearing PAB on the coronal plane tilt angle of ankle joint and the associated muscles around the ankle joint was analyzed. Results: During the semi-squat landing, the MVC% of the tibialis anterior muscle, lateral gastrocnemius muscle and peroneus longus muscle were positively correlated with the ankle coronal plane tilt angle in paratroopers wearing and without wearing PAB, and the correlations were statistically significant (P<0.05). At the same height, compared with those without PAB, the coronal plane tilt angle of the ankle joint decreased during semi-squat landing in paratroopers PAB, and the differences were statistically significant (P<0.05). At the landing moment of the same height, compared with those without PAB, the MVC% of lateral gastrocnemius muscle decreased and the MVC% of peroneus longus muscle increased in paratroopers wearing PAB, and the differences were statistically significant (P<0.05). After the landing moment until the standing stage (100-200 ms) at 1.5 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the differences were statistically significant (P<0.05). In the post-standing stage (200 ms) at 2.0 m height, the MVC% of the tibialis anterior muscle decreased in paratroopers wearing PAB compared with those without PAB, and the difference was statistically significant (P<0.05) . Conclusion: Wearing PAB can reduce the ankle coronal plane tilt angle, improve ankle stability, reduce the muscle load of the lateral gastrocnemius muscle at the moment of landing, and reduce the load of the tibialis anterior muscle after landing, but increase the peroneus longus muscle load at the moment of landing.


Assuntos
Articulação do Tornozelo , Músculo Esquelético , Humanos , Masculino , Articulação do Tornozelo/fisiologia , Músculo Esquelético/fisiologia , Adulto Jovem , Postura/fisiologia , Adulto , Braquetes , Fenômenos Biomecânicos , Suporte de Carga/fisiologia , Tornozelo/fisiologia
12.
bioRxiv ; 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38915691

RESUMO

Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis ( Tv ) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv- DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, like Tv FAP40 and Tv FAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of Tv FAP40 and has characteristics of a drug molecule. This first atomic model of the Tv -DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform the rational design of therapeutics.

13.
Biol Imaging ; 4: e7, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38828212

RESUMO

Cryogenic electron tomography (cryoET) is capable of determining in situ biological structures of molecular complexes at near-atomic resolution by averaging half a million subtomograms. While abundant complexes/particles are often clustered in arrays, precisely locating and seamlessly averaging such particles across many tomograms present major challenges. Here, we developed TomoNet, a software package with a modern graphical user interface to carry out the entire pipeline of cryoET and subtomogram averaging to achieve high resolution. TomoNet features built-in automatic particle picking and three-dimensional (3D) classification functions and integrates commonly used packages to streamline high-resolution subtomogram averaging for structures in 1D, 2D, or 3D arrays. Automatic particle picking is accomplished in two complementary ways: one based on template matching and the other using deep learning. TomoNet's hierarchical file organization and visual display facilitate efficient data management as required for large cryoET datasets. Applications of TomoNet to three types of datasets demonstrate its capability of efficient and accurate particle picking on flexible and imperfect lattices to obtain high-resolution 3D biological structures: virus-like particles, bacterial surface layers within cellular lamellae, and membranes decorated with nuclear egress protein complexes. These results demonstrate TomoNet's potential for broad applications to various cryoET projects targeting high-resolution in situ structures.

14.
J Hosp Infect ; 150: 40-50, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38823643

RESUMO

BACKGROUND: Antimicrobial-coated sutures are one of the strategies to avoid surgical site infection (SSI) caused by microbial colonization on the surface of surgical sutures. AIM: To investigate the effectiveness of antimicrobial-coated sutures in reducing SSI and develop the latest systematic evaluation evidence for clinical SSI prevention and the use of antimicrobial-coated sutures. METHODS: The databases of MEDLINE, Embase, CINAHL, Cochrane, African Index Medicus, and WHO Global Health were searched from October 10th, 1990 to March 3rd, 2023 with language restricted to English, Spanish, and French. Meta-analysis was used to evaluate the impact of antimicrobial-coated sutures on SSI and whether their effectiveness is influenced by the type of sutures or wounds. Subgroup analyses were conducted based on type of sutures and wounds. Finally, quality of the retrieved evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). FINDINGS: Twenty-six randomized control trials (RCTs) and nine observational studies (OBSs) met the inclusion criteria. Antimicrobial sutures significantly reduced SSI risk (RCTs: odds ratio: 0.74; 95% confidence interval: 0.63-0.87; P = 0.0002; OBSs: OR: 0.61; 95% CI: 0.48-0.76; P < 0.0001). Only subgroup analysis of Polydioxanone Suture (PDS) Plus vs PDS, Vicryl Plus vs Vicryl and mixed wounds revealed consistent results in favour of antimicrobial-coated sutures. According to GRADE, the quality of RCT evidence is moderate, while that of OBS evidence is low. CONCLUSION: Antimicrobial-coated sutures are effective in reducing the risk of postoperative SSI among a large number of surgical patients. However, the available evidence is of moderate/low quality and many studies had conflicts of interest.


Assuntos
Infecção da Ferida Cirúrgica , Suturas , Infecção da Ferida Cirúrgica/prevenção & controle , Humanos , Suturas/microbiologia , Anti-Infecciosos/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Materiais Revestidos Biocompatíveis
15.
Nature ; 630(8017): 613-618, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38811737

RESUMO

A large qubit capacity and an individual readout capability are two crucial requirements for large-scale quantum computing and simulation1. As one of the leading physical platforms for quantum information processing, the ion trap has achieved a quantum simulation of tens of ions with site-resolved readout in a one-dimensional Paul trap2-4 and of hundreds of ions with global observables in a two-dimensional (2D) Penning trap5,6. However, integrating these two features into a single system is still very challenging. Here we report the stable trapping of 512 ions in a 2D Wigner crystal and the sideband cooling of their transverse motion. We demonstrate the quantum simulation of long-range quantum Ising models with tunable coupling strengths and patterns, with or without frustration, using 300 ions. Enabled by the site resolution in the single-shot measurement, we observe rich spatial correlation patterns in the quasi-adiabatically prepared ground states, which allows us to verify quantum simulation results by comparing the measured two-spin correlations with the calculated collective phonon modes and with classical simulated annealing. We further probe the quench dynamics of the Ising model in a transverse field to demonstrate quantum sampling tasks. Our work paves the way for simulating classically intractable quantum dynamics and for running noisy intermediate-scale quantum algorithms7,8 using 2D ion trap quantum simulators.

16.
Virology ; 596: 110115, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38805802

RESUMO

Human cytomegalovirus (HCMV) replication relies on a nucleocapsid coat of the 150 kDa, subfamily-specific tegument phosphoprotein (pp150) to regulate cytoplasmic virion maturation. While recent structural studies revealed pp150-capsid interactions, the role of specific amino-acids involved in these interactions have not been established experimentally. In this study, pp150 and the small capsid protein (SCP), one of pp150's binding partners found atop the major capsid protein (MCP), were subjected to mutational and structural analyses. Mutations to clusters of polar or hydrophobic residues along the pp150-SCP interface abolished viral replication, with no replication detected in mutant virus-infected cells. Notably, a single amino acid mutation (pp150 K255E) at the pp150-MCP interface significantly attenuated viral replication, unlike in pp150-deletion mutants where capsids degraded outside host nuclei. These functionally significant mutations targeting pp150-capsid interactions, particularly the pp150 K255E replication-attenuated mutant, can be explored to overcome the historical challenges of developing effective antivirals and vaccines against HCMV infection.


Assuntos
Proteínas do Capsídeo , Citomegalovirus , Fosfoproteínas , Replicação Viral , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/química , Humanos , Citomegalovirus/genética , Citomegalovirus/fisiologia , Citomegalovirus/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Fosfoproteínas/química , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismo , Proteínas da Matriz Viral/química , Ligação Proteica , Mutagênese , Mutação , Linhagem Celular , Modelos Moleculares
17.
Zhonghua Xue Ye Xue Za Zhi ; 45(3): 215-224, 2024 Mar 14.
Artigo em Chinês | MEDLINE | ID: mdl-38716592

RESUMO

Objective: To retrospectively analyze the treatment status of tyrosine kinase inhibitors (TKI) in newly diagnosed patients with chronic myeloid leukemia (CML) in China. Methods: Data of chronic phase (CP) and accelerated phase (AP) CML patients diagnosed from January 2006 to December 2022 from 77 centers, ≥18 years old, and receiving initial imatinib, nilotinib, dasatinib or flumatinib-therapy within 6 months after diagnosis in China with complete data were retrospectively interrogated. The choice of initial TKI, current TKI medications, treatment switch and reasons, treatment responses and outcomes as well as the variables associated with them were analyzed. Results: 6 893 patients in CP (n=6 453, 93.6%) or AP (n=440, 6.4%) receiving initial imatinib (n=4 906, 71.2%), nilotinib (n=1 157, 16.8%), dasatinib (n=298, 4.3%) or flumatinib (n=532, 7.2%) -therapy. With the median follow-up of 43 (IQR 22-75) months, 1 581 (22.9%) patients switched TKI due to resistance (n=1 055, 15.3%), intolerance (n=248, 3.6%), pursuit of better efficacy (n=168, 2.4%), economic or other reasons (n=110, 1.6%). The frequency of switching TKI in AP patients was significantly-higher than that in CP patients (44.1% vs 21.5%, P<0.001), and more AP patients switched TKI due to resistance than CP patients (75.3% vs 66.1%, P=0.011). Multi-variable analyses showed that male, lower HGB concentration and ELTS intermediate/high-risk cohort were associated with lower cytogenetic and molecular responses rate and poor outcomes in CP patients; higher WBC count and initial the second-generation TKI treatment, the higher response rates; Ph(+) ACA at diagnosis, poor PFS. However, Sokal intermediate/high-risk cohort was only significantly-associated with lower CCyR and MMR rates and the poor PFS. Lower HGB concentration and larger spleen size were significantly-associated with the lower cytogenetic and molecular response rates in AP patients; initial the second-generation TKI treatment, the higher treatment response rates; lower PLT count, higher blasts and Ph(+) ACA, poorer TFS; Ph(+) ACA, poorer OS. Conclusion: At present, the vast majority of newly-diagnosed CML-CP or AP patients could benefit from TKI treatment in the long term with the good treatment responses and survival outcomes.


Assuntos
Dasatinibe , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , China , Dasatinibe/uso terapêutico , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Pirimidinas/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento , /uso terapêutico
19.
J Endocrinol Invest ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602658

RESUMO

PURPOSE: Living with type 1 diabetes requires burdensome and complex daily diabetes self-management behaviors. This study aimed to determine the association between integrated behavior performance and HbA1c, while identifying the behavior with the most significant impact on HbA1c. METHODS: A simple and feasible questionnaire was used to collect diabetes self-management behavior in patients with type 1 diabetes (n = 904). We assessed six dimensions of behavior performance: continuous glucose monitor (CGM) usage, frequent glucose testing, insulin pump usage, carbohydrate counting application, adjustment of insulin doses, and usage of apps for diabetes management. We evaluated the association between these behaviors and HbA1c. RESULTS: In total, 21.3% of patients performed none of the allotted behavior, while 28.5% of patients had a total behavior score of 3 or more. 63.6% of patients with a behavior score ≥ 3 achieved HbA1c goal, contrasting with only 30.4% of patients with a behavior score of 0-1. There was a mean 0.54% ± 0.05% decrease in HbA1c for each 1-unit increase in total behavior score after adjustment for age, family education and diabetes duration. Each behavior was independently correlated with a lower HbA1c level, with CGM having the most significant effect on HbA1c levels. CONCLUSIONS: Six optimal self-management behaviors, especially CGM usage, were associated with improved glycemic control, emphasizing the feasibility of implementing a simplified version of DSMES in the routine clinical care. REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT03610984.

20.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(3): 585-593, 2024 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-38597451

RESUMO

OBJECTIVE: To develop a multi-modal deep learning method for automatic classification of immune-mediated glomerular diseases based on images of optical microscopy (OM), immunofluorescence microscopy (IM), and transmission electron microscopy (TEM). METHODS: We retrospectively collected the pathological images from 273 patients and constructed a multi-modal multi- instance model for classification of 3 immune-mediated glomerular diseases, namely immunoglobulin A nephropathy (IgAN), membranous nephropathy (MN), and lupus nephritis (LN). This model adopts an instance-level multi-instance learning (I-MIL) method to select the TEM images for multi-modal feature fusion with the OM images and IM images of the same patient. By comparing this model with unimodal and bimodal models, we explored different combinations of the 3 modalities and the optimal methods for modal feature fusion. RESULTS: The multi-modal multi-instance model combining OM, IM, and TEM images had a disease classification accuracy of (88.34±2.12)%, superior to that of the optimal unimodal model [(87.08±4.25)%] and that of the optimal bimodal model [(87.92±3.06)%]. CONCLUSION: This multi- modal multi- instance model based on OM, IM, and TEM images can achieve automatic classification of immune-mediated glomerular diseases with a good classification accuracy.


Assuntos
Glomerulonefrite por IGA , Levamisol/análogos & derivados , Humanos , Estudos Retrospectivos , Microscopia de Fluorescência , Microscopia Eletrônica de Transmissão
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