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1.
Am J Epidemiol ; 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38896063

RESUMO

Allostatic load (AL) is an intermediary outcome through which neighborhood drivers of health may impact cancer survivorship outcomes. We examined associations of neighborhood stressors and AL in 2,553 women with breast cancer recruited into the Pathways Study in 2006-2013. AL score was derived from biomarkers in the cardiovascular, metabolic, and immune domains of physiological stress measured within 3 years after baseline. Neighborhood data were appended to participants' geocoded baseline addresses. Odds ratios (OR) and 95% confidence intervals (CI) were used to estimate associations between neighborhood stressors and risk of higher AL score. Adjusting for age and stage, high AL was positively associated with low versus high neighborhood socioeconomic status (nSES; OR=2.24, 95% CI=1.61-3.12) and green space (OR=1.55, 95% CI=1.18-2.03); high versus low traffic (OR=1.32, 95% CI=1.01-1.72), crime (OR=1.32, 95% CI=1.05-1.67), and household crowding (OR=1.57, 95% CI=1.22-2.01); and more versus no fast-food restaurants (OR=1.50, 95% CI=1.21-1.84). Associations remained for nSES and fast-food restaurants after co-adjustment with other neighborhood stressors, and for fast-food restaurants after additional adjustment with individual sociodemographic and lifestyle factors. Our preliminary findings can inform further studies of the physiological effects of neighborhood stressors, which collectively may help improve survivorship outcomes for the growing population of breast cancer survivors.

2.
Int J Surg Case Rep ; 120: 109849, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38875824

RESUMO

INTRODUCTION: Tumours of salivary glands are rare and have various histo-pathological subtypes. Myoepitheliomas were first classified by Sheldon et al. and the criterion to classify or diagnose it was first defined by Barnes et al. and Sciubba and Brannon. Myoepithelioma accounts for less than 1 % of all salivary gland tumours, 40 % of these tumours occur in the parotid gland while 21 % occur in the minor salivary glands. A case of myoepithelioma of a minor salivary gland of the cheek is described, emphasizing the problems of the differential diagnosis. PRESENTATION OF THE CASE: A 40-year-old female reported to the department with a complaint of a cheek bite on her right side for a few months. The physical examination showed a presence of lobulated whitish mucosa on the right buccal mucosa at the level of the occlusal plane, on palpation it revealed a non-painful mass approximately 1.5 cm in radius, mobile to bimanual palpation. An excisional biopsy was performed under local anaesthesia. Microscopic and immunohistochemistry confirmed the tumour to be a myoepithelioma of a minor salivary gland with the absence of definitive features of malignancy. DISCUSSION: Due to their infrequency and multiplicity of histopathology, myoepitheliomas present difficulties in diagnosis. Cellular varieties can be misdiagnosed as malignancies. A key to determining diagnostic criteria for myoepitheliomas is to study cellular morphology, cytoplasmic filament expression, and ultrastructural features of the tumour and apply this information to defining myoepitheliomas. CONCLUSION: Myoepitheliomas are rare tumours, utilization of immunohistochemical staining and electron microscopy are useful tools for the diagnosis of myoepitheliomas to ensure proper treatment and follow-up.

3.
J Maxillofac Oral Surg ; 23(3): 597-607, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38911406

RESUMO

Introduction: A systematic review of the literature on the donor site morbidity in patients undergoing Maxillofacial reconstruction was performed. The two widely used flaps namely free fibula flap (FFF) and DCIA flap were compared to answer the following questions: (1) Is donor site morbidity significantly different in patients undergoing maxillofacial reconstruction with FFF and DCIA flap? (2) Should donor site morbidity be considered as the criteria for choosing the flap for reconstruction. Materials and methods: The search strategy was based on PRISMA guidelines. Various electronic databases were searched. On reviewing the seven articles included in our systematic review, we found out oral squamous cell carcinoma to be the most common pathology leading to the defects in head and neck region requiring reconstruction with free flaps. Results: A total of 531 participants were investigated who underwent maxillofacial reconstruction using FFF and DCIA flap. The study included both the genders. The participants were assessed for short- and long-term donor site morbidity after the microvascular surgery. Mean age is 45-60 years. Three out of seven studies showed DCIA to have lesser complications at donor site than fibula group. While other two studies proved FFF to be better than DCIA. One study proved low donor site morbidity with regard to both the flap. Conclusion: The free fibula being the flap of choice in head and neck reconstruction has a comparable donor site morbidity to DCIA. The advantages of the iliac artery flap include natural curvature, abundant vertical and horizontal bone height for bone contouring and osseointegration, hidden scar, low incidence of wound healing problems and minimal effect on function and quality of life at long-term follow-up. Thus, it makes it the free flap of choice that one cannot avoid. This systematic review was registered at PROSPERO (CRD42021268949).

4.
bioRxiv ; 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38496420

RESUMO

Bacteria can tolerate antibiotics despite lacking the genetic components for resistance. The prevailing notion is that tolerance results from depleted cellular energy or cell dormancy. In contrast to this view, many cells in the tolerant population of Escherichia coli can exhibit motility - a phenomenon that requires cellular energy, specifically, the proton-motive force (PMF). As these motile-tolerant cells are challenging to isolate from the heterogeneous tolerant population, their survival mechanism is unknown. Here, we discovered that motile bacteria segregate themselves from the tolerant population under micro-confinement, owing to their unique ability to penetrate micron-sized channels. Single-cell measurements on the motile-tolerant population showed that the cells retained a high PMF, but they did not survive through active efflux alone. By utilizing growth assays, single-cell fluorescence studies, and chemotaxis assays, we showed that the cells survived by dynamically inhibiting the function of existing porins in the outer membrane. A drug transport model for porin-mediated intake and efflux pump-mediated expulsion suggested that energetic tolerant cells withstand antibiotics by constricting their porins. The novel porin adaptation we have uncovered is independent of gene expression changes and may involve electrostatic modifications within individual porins to prevent extracellular ligand entry.

5.
Cancer Epidemiol Biomarkers Prev ; 33(5): 703-711, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38372643

RESUMO

BACKGROUND: Ultrafine particles (UFP) are unregulated air pollutants abundant in aviation exhaust. Emerging evidence suggests that UFPs may impact lung health due to their high surface area-to-mass ratio and deep penetration into airways. This study aimed to assess long-term exposure to airport-related UFPs and lung cancer incidence in a multiethnic population in Los Angeles County. METHODS: Within the California Multiethnic Cohort, we examined the association between long-term exposure to airport-related UFPs and lung cancer incidence. Multivariable Cox proportional hazards regression models were used to estimate the effect of UFP exposure on lung cancer incidence. Subgroup analyses by demographics, histology and smoking status were conducted. RESULTS: Airport-related UFP exposure was not associated with lung cancer risk [per one IGR HR, 1.01; 95% confidence interval (CI), 0.97-1.05] overall and across race/ethnicity. A suggestive positive association was observed between a one IQR increase in UFP exposure and lung squamous cell carcinoma (SCC) risk (HR, 1.08; 95% CI, 1.00-1.17) with a Phet for histology = 0.05. Positive associations were observed in 5-year lag analysis for SCC (HR, 1.12; 95% CI, CI, 1.02-1.22) and large cell carcinoma risk (HR, 1.23; 95% CI, 1.01-1.49) with a Phet for histology = 0.01. CONCLUSIONS: This large prospective cohort analysis suggests a potential association between airport-related UFP exposure and specific lung histologies. The findings align with research indicating that UFPs found in aviation exhaust may induce inflammatory and oxidative injury leading to SCC. IMPACT: These results highlight the potential role of airport-related UFP exposure in the development of lung SCC.


Assuntos
Aeroportos , Neoplasias Pulmonares , Material Particulado , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/etiologia , Masculino , Feminino , Material Particulado/efeitos adversos , Material Particulado/análise , Pessoa de Meia-Idade , Idoso , Fatores de Risco , Estudos de Coortes , Poluentes Atmosféricos/efeitos adversos , Estudos Prospectivos , Exposição Ambiental/efeitos adversos , Incidência , Etnicidade/estatística & dados numéricos , Los Angeles/epidemiologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-38048436

RESUMO

Helicobacter pylori infections are a major cause of peptic ulcers and gastric cancers. The development of robust inflammation in response to these flagellated, motile bacteria is correlated with poor prognosis. Chemotaxis plays a crucial role in H. pylori colonization, enabling the bacteria to swim toward favorable chemical environments. Unlike the model species of bacterial chemotaxis, Escherichia coli, H. pylori cells possess polar flagella. They run forward by rotating their flagella counterclockwise, whereas backward runs are achieved by rotating their flagella clockwise. We delve into the implications of certain features of the canonical model of chemotaxis on our understanding of biased migration in polarly flagellated bacteria such as H. pylori. In particular, we predict how the translational displacement of H. pylori cells during a backward run could give rise to chemotaxis errors within the canonical framework. Also, H. pylori lack key chemotaxis enzymes found in E. coli, without which sensitive detection of ligands with a wide dynamic range seems unlikely. Despite these problems, H. pylori exhibit robust ability to migrate toward urea-rich sources. We emphasize various unresolved questions regarding the biophysical mechanisms of chemotaxis in H. pylori, shedding light on potential directions for future research. Understanding the intricacies of biased migration in H. pylori could offer valuable insights into how pathogens breach various protective barriers in the human host. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering , Volume 15 is June 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

7.
Saudi Dent J ; 35(7): 841-844, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38025593

RESUMO

Background: Traditionally bur has been used to carry out osteotomy. In a developing country like India, the cost of surgical treatment is the important factor in determining treatment plan. Although the use of bur is cost-effective and efficient, with the advent of newer technology, it is getting replaced with a saw. Aim: To evaluate and compare the use of reciprocating saw and bur in Le Fort I Osteotomy for superior repositioning of the maxilla. Materials and Methods: Patients referred from the Department of Orthodontics for the surgical correction of vertical maxillary excess (VME). They were divided into two groups. In group I, osteotomy was performed with Synthes Reciprocating Saw and in group II, bur was used. The parameters recorded in both the groups were time required for the completion of down-fracture, precision of the osteotomy cut (margins of the cut), and ease of superior repositioning. Data was collected from both the groups for comparison. Results: A total of 14 patients with VME were included in the study. They were divided into two groups. Seven study participants were allotted to each group. In group I, Synthes Reciprocating Saw was used while in group II, a bur was used to carry out the osteotomy cut. In group I, the average time required to complete the down-fracture of the maxilla was 3.5-4 min while in group II it was more than 8 min. The margins of the osteotomy cut were smooth and regular and there was bone-to-bone contact during superior repositioning in Group I. Conclusion: The combination of the use of a saw for inferior osteotomy and a bur for the superior cut would be more beneficial in the superior repositioning of the maxilla.

8.
Antimicrob Resist Infect Control ; 12(1): 115, 2023 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-37858209

RESUMO

BACKGROUND: Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak. METHODS: We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 h after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression. RESULTS: Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001). CONCLUSION: We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli. These findings may help better tailor clinical treatment of patients with recurrent urinary tract infections after an initial episode caused by ESBL-E. coli.


Assuntos
Bacteriúria , Infecções por Escherichia coli , Infecções Urinárias , Humanos , Escherichia coli , Bacteriúria/epidemiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/tratamento farmacológico , Fatores de Risco , São Francisco , beta-Lactamases/genética , Infecções Urinárias/epidemiologia , Infecções Urinárias/tratamento farmacológico , Hospitais , Análise por Conglomerados
9.
Int J Surg Case Rep ; 112: 108983, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37883872

RESUMO

INTRODUCTION: Autotransplantation technique involves extraction of tooth from the recipient site and donor tooth without damage, placing and stabilizing donor tooth within same individual. The use of autogenous bone combined with platelet rich fibrin (PRF) and platelet rich plasma (PRP) seems to be favorable to achieve stable alveolar bone. Thus we provide an innovative adjuvant method for enhancing bone formation using PRF and inter-radicular bone with PRP as autogenous graft. PRESENTATION OF CASE: A 26 year old healthy female individual reported university teaching hospital to outpatient department of oral and maxillofacial surgery, with complain of decayed tooth. On clinical and radiographic examination it was diagnosed was chronic irreversible pulpitis with to left maxillary first molar. Looking at clinical profile, age and health status an autogenous tooth transplant was advised. DISCUSSION: Periodontal ligament, interradicular bone autografts, PRF and PRP has potential to induce formation of alveolar bone and is recommended in cases of atrophy of alveolar process. CONCLUSION: The solution mentioned can be hypothesized to improve - quantity and quality of bone formed, reduce the chances of ankylosis of the tooth, bone loss, sinus perforation.

10.
J Maxillofac Oral Surg ; : 1-22, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-37362874

RESUMO

Introduction: Mucormycosis emerged as a wildfire in post-covid-19 infected patients. Most frequently involved sites of mucormycosis are rhino-orbital, rhino-sinusal and rhino-orbito-cerebral. The hallmark sign of mucormycosis is tissue necrosis, which is often a late sign. The fatality rate of mucormycosis is 46% globally. Despite early aggressive combined surgical and medical therapy, the prognosis of mucormycosis is poor. Methods: We searched the electronic database of PubMed, web of science, Embase, Scopus and Google Scholar from Jan 2020 until December 2021 using keywords. We retrieved all the granular details of original research articles, case reports/series of patients with rhino-orbito-cerebral mucormycosis (ROCM), and COVID-19 reported worldwide. Subsequently, we analyzed the patient characteristics, associated comorbidities, location of mucormycosis, treatment given and its outcome in people with COVID-19. (Prospero registration-CRD42021256830, June 4, 2021). Results: Overall, 544 rhino-orbito-cerebral mucormycosis patients were included in our review with a history of Covid-19 infection. Out of which 410 patients had diabetes mellitus which has proven to be major contributing immunocompromised disease. Other diseases like hypertension, chronic kidney diseases, hypothyroidism, etc., were also attributed as an immunocompromised disease causing increased number of covid associated mucormycosis cases. We found out that total number of patients alive after taking only antifungal drug treatment were 25 in number, whereas total number of patients alive when antifungal drugs were combined with surgical intervention were 428 which was significantly higher. Conclusion: Our systematic review concluded that surgical debridement should be performed whenever feasible in parallel to antifungal treatment in order to reduce the mortality rate of COVID-19 associated rhino-orbito-cerebral mucormycosis patients.

11.
Res Sq ; 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37292942

RESUMO

Background: Urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) may occur as outbreaks due to common-source exposures. Yet, it is currently unknown if they cluster geographically as would be expected as part of an outbreak. Methods: We collected electronic health record data on all patients living in San Francisco with culture-documented community-onset E. coli bacteriuria in a safety-net public healthcare system from January 2014 to March 2020 (diagnosed < 48 hours after hospital admission or in outpatient clinical settings without a hospitalization in the past 90 days). We assessed the presence of spatial clusters of (1) ESBL-E. coli bacteriuria episodes, and (2) individuals with any ESBL-E. coli bacteriuria episode, with Global and Local Moran's I. We evaluated differences in prevalence of bacteriuria recurrence by ESBL-production by Poisson regression. Results: Out of 4,304 unique individuals, we identified spatial clusters of ESBL-E. coli bacteriuria episodes (n = 461) compared to non-ESBL-E. coli bacteriuria episodes (n = 5477; Global Moran's p < 0.001). Spatial clusters of individuals with any bacteriuria caused by ESBL-E. coli were not identified (p = 0.43). Bacteriuria recurrence was more likely to occur with ESBL-E. coli (odds ratio [OR] 2.78, 95% confidence interval [95% CI] 2.10, 3.66, p < 0.001), particularly after an initial ESBL-E. coli bacteriuria episode (OR 2.27, 95% CI 1.82, 2.83, p < 0.001). Conclusion: We found spatial clusters of ESBL-E. coli bacteriuria episodes. However, this was partly explained by clustering within individuals more than between individuals, as having an ESBL-E. coli bacteriuria was associated with recurrence with ESBL-E. coli.

12.
Am J Obstet Gynecol ; 229(4): 366-376.e8, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37116824

RESUMO

Ovarian cancer is the fifth leading cause of cancer-associated mortality among US women with survival disparities seen across race, ethnicity, and socioeconomic status, even after accounting for histology, stage, treatment, and other clinical factors. Neighborhood context can play an important role in ovarian cancer survival, and, to the extent to which minority racial and ethnic groups and populations of lower socioeconomic status are more likely to be segregated into neighborhoods with lower quality social, built, and physical environment, these contextual factors may be a critical component of ovarian cancer survival disparities. Understanding factors associated with ovarian cancer outcome disparities will allow clinicians to identify patients at risk for worse outcomes and point to measures, such as social support programs or transportation aid, that can help to ameliorate such disparities. However, research on the impact of neighborhood contextual factors in ovarian cancer survival and in disparities in ovarian cancer survival is limited. This commentary focuses on the following neighborhood contextual domains: structural and institutional context, social context, physical context represented by environmental exposures, built environment, rurality, and healthcare access. The research conducted to date is presented and clinical implications and recommendations for future interventions and studies to address disparities in ovarian cancer outcomes are proposed.


Assuntos
Etnicidade , Neoplasias Ovarianas , Humanos , Feminino , Fatores Socioeconômicos , Classe Social , Neoplasias Ovarianas/terapia , Meio Social , Disparidades em Assistência à Saúde
13.
Int J Surg Case Rep ; 105: 108039, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36965445

RESUMO

INTRODUCTION AND IMPORTANCE: Temporomandibular joint (TMJ) ankylosis triad includes TMJ ankylosis, micrognathia, and obstructive sleep apnea (OSA) which is common in long-standing cases of TMJ ankylosis. Unilateral long-standing cases of TMJ ankylosis also result in a severe discrepancy in the midline of the chin. CASE PRESENTATION: A young adult female presented with restricted mouth opening and daylight sleepiness. Her AHI was mild and there was excessive facial disfigurement. Right-side TMJ ankylosis was diagnosed with compromised posterior airway space and Ramal height was also short on the affected side. Chin has severely deviated to the affected side. CLINICAL DISCUSSION: Treatment protocols for TMJ ankylosis are different for different case scenarios. A proper protocol derivation is a must looking into the clinical and radiographical examination of the patient. As mentioned in previous literature, anti-Kaban's protocol has been shown to provide good results. A genioplasty improves the chin midline deviation. CONCLUSION: A careful assessment and a proper treatment plan should be selected for the management and early relief of the symptoms of the patient. Thorough knowledge and update should be available to the operating surgeon to choose the correct treatment plan for the management of a triad patient.

14.
mBio ; 14(1): e0238422, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36598258

RESUMO

Bacterial infections that are difficult to eradicate are often treated by sequentially exposing the bacteria to different antibiotics. Although effective, this approach can give rise to epigenetic or other phenomena that may help some cells adapt to and tolerate the antibiotics. Characteristics of such adapted cells are dormancy and low energy levels, which promote survival without lending long-term genetic resistance against antibiotics. In this work, we quantified motility in cells of Escherichia coli that adapted and survived sequential exposure to lethal doses of antibiotics. In populations that adapted to transcriptional inhibition by rifampicin, we observed that ~1 of 3 cells continued swimming for several hours in the presence of lethal concentrations of ampicillin. As motility is powered by proton motive force (PMF), our results suggested that many adapted cells retained a high PMF. Single-cell growth assays revealed that the high-PMF cells resuscitated and divided upon the removal of ampicillin, just as the low-PMF cells did, a behavior reminiscent of persister cells. Our results are consistent with the notion that cells in a clonal population may employ multiple different mechanisms to adapt to antibiotic stresses. Variable PMF is likely a feature of a bet-hedging strategy: a fraction of the adapted cell population lies dormant while the other fraction retains high PMF to be able to swim out of the deleterious environment. IMPORTANCE Bacterial cells with low PMF may survive antibiotic stress due to dormancy, which favors nonheritable resistance without genetic mutations or acquisitions. On the other hand, cells with high PMF are less tolerant, as PMF helps in the uptake of certain antibiotics. Here, we quantified flagellar motility as an indirect measure of the PMF in cells of Escherichia coli that had adapted to ampicillin. Despite the disadvantage of maintaining a high PMF in the presence of antibiotics, we observed high PMF in ~30% of the cells, as evidenced by their ability to swim rapidly for several hours. These and other results were consistent with the idea that antibiotic tolerance can arise via different mechanisms in a clonal population.


Assuntos
Antibacterianos , Força Próton-Motriz , Antibacterianos/farmacologia , Escherichia coli/genética , Resistência Microbiana a Medicamentos , Ampicilina/farmacologia
15.
ACS ES T Water ; 3(9): 2938-2947, 2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-38204756

RESUMO

The current methods used to study photocatalysis-assisted water disinfection at a laboratory scale may not lead to process scale-up for large-scale implementation. These methods do not capture the process complexity and address all the factors underlying disinfection kinetics, including the physical characteristics (e.g., shape and size) of the photocatalyst, the light intensity, the form of the catalyst (e.g., free-floating and immobilized), and the photocatalyst-microorganism interaction mode (e.g., collision mode and constant contact mode). This drawback can be overcome using in situ methods to track the interaction between the photocatalysts and the microorganisms (e.g., Escherichia coli) and thereby engineering the resulting disinfection kinetics. Contextually, this study employed microscopy and particle-tracking algorithms to quantify in situ cell motility of E. coli undergoing titanium dioxide (TiO2) nanowire-assisted photocatalysis, which was observed to correlate with cell viability closely. This experimentation also informed that the E. coli bacterium interacted with the photocatalysts through collisions (without sustained contact), which allowed for phenomenological modeling of the observed first-order kinetics of E. coli inactivation. Addition of fluorescent-tagging assays to microscopy revealed that cell membrane integrity loss is the primary mode of bacterial inactivation. This methodology is independent of the microorganism or the photocatalyst type and hence is expected to be beneficial for engineering disinfection kinetics.

17.
Front Microbiol ; 13: 928408, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35875555

RESUMO

The evolution of the bacterial flagellum gave rise to motility and repurposing of a signaling network, now termed the chemotaxis network, enabled biasing of cell movements. This made it possible for the bacterium to seek out favorable chemical environments. To enable chemotaxis, the chemotaxis network sensitively detects extracellular chemical stimuli and appropriately modulates flagellar functions. Additionally, the flagellar motor itself is capable of detecting mechanical stimuli and adapts its structure and function in response, likely triggering a transition from planktonic to surface-associated lifestyles. Recent work has shown a link between the flagellar motor's response to mechanical stimuli and the chemotactic output. Here, we elaborate on this link and discuss how it likely helps the cell sense and adapt to changes in its swimming speeds in different environments. We discuss the mechanism whereby the motor precisely tunes its chemotaxis output under different mechanical loads, analogous to proprioception in higher order organisms. We speculate on the roles bacterial proprioception might play in a variety of phenomena including the transition to surface-associated lifestyles such as swarming and biofilms.

18.
PLoS Med ; 19(6): e1004031, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35727819

RESUMO

BACKGROUND: Cardiovascular disease (CVD) disproportionately affects Black adults in the United States. This is increasingly acknowledged to be due to inequitable distribution of health-promoting resources. One potential contributor is inequities in educational opportunities, although it is unclear what aspects of education are most salient. School racial segregation may affect cardiovascular health by increasing stress, constraining socioeconomic opportunities, and altering health behaviors. We investigated the association between school segregation and Black adults' CVD risk. METHODS AND FINDINGS: We leveraged a natural experiment created by quasi-random (i.e., arbitrary) timing of local court decisions since 1991 that released school districts from court-ordered desegregation. We used the Panel Study of Income Dynamics (PSID) (1991 to 2017), linked with district-level school segregation measures and desegregation court order status. The sample included 1,053 Black participants who ever resided in school districts that were under a court desegregation order in 1991. The exposure was mean school segregation during observed schooling years. Outcomes included several adult CVD risk factors and outcomes. We fitted standard ordinary least squares (OLS) multivariable linear regression models, then conducted instrumental variables (IV) analysis, using the proportion of schooling years spent in districts that had been released from court-ordered desegregation as an instrument. We adjusted for individual- and district-level preexposure confounders, birth year, and state fixed effects. In standard linear models, school segregation was associated with a lower probability of good self-rated health (-0.05 percentage points per SD of the segregation index; 95% CI: -0.08, -0.03; p < 0.001) and a higher probability of binge drinking (0.04 percentage points; 95% CI: 0.002, 0.07; p = 0.04) and heart disease (0.01 percentage points; 95% CI: 0.002, 0.15; p = 0.007). IV analyses also found that school segregation was associated with a lower probability of good self-rated health (-0.09 percentage points; 95% CI: -0.17, -0.02, p = 0.02) and a higher probability of binge drinking (0.17 percentage points; 95% CI: 0.04, 0.30, p = 0.008). For IV estimates, only binge drinking was robust to adjustments for multiple hypothesis testing. Limitations included self-reported outcomes and potential residual confounding and exposure misclassification. CONCLUSIONS: School segregation exposure in childhood may have longstanding impacts on Black adults' cardiovascular health. Future research should replicate these analyses in larger samples and explore potential mechanisms. Given the recent rise in school segregation, this study has implications for policies and programs to address racial inequities in CVD.


Assuntos
Consumo Excessivo de Bebidas Alcoólicas , Doenças Cardiovasculares , Segregação Social , Adulto , População Negra , Doenças Cardiovasculares/epidemiologia , Humanos , Instituições Acadêmicas , Estados Unidos/epidemiologia
19.
Adv Sci (Weinh) ; 9(23): e2201248, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35712768

RESUMO

Migrating cells must deform their stiff cell nucleus to move through pores and fibers in tissue. Lamin A/C is known to hinder cell migration by limiting nuclear deformation and passage through confining channels, but its role in nuclear deformation and passage through fibrous environments is less clear. Cell and nuclear migration through discrete, closely spaced, slender obstacles which mimic the mechanical properties of collagen fibers are studied. Nuclei bypass slender obstacles while preserving their overall morphology by deforming around them with deep local invaginations of little resisting force. The obstacles do not impede the nuclear trajectory and do not cause rupture of the nuclear envelope. Nuclei likewise deform around single collagen fibers in cells migrating in 3D collagen gels. In contrast to its limiting role in nuclear passage through confining channels, lamin A/C facilitates nuclear deformation and passage through fibrous environments; nuclei in lamin-null (Lmna-/- ) cells lose their overall morphology and become entangled on the obstacles. Analogous to surface tension-mediated deformation of a liquid drop, lamin A/C imparts a surface tension on the nucleus that allows nuclear invaginations with little mechanical resistance, preventing nuclear entanglement and allowing nuclear passage through fibrous environments.


Assuntos
Núcleo Celular , Lamina Tipo A , Núcleo Celular/metabolismo , Colágeno , Lamina Tipo A/metabolismo , Membrana Nuclear/metabolismo , Tensão Superficial
20.
PNAS Nexus ; 1(2)2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35719892

RESUMO

Indole is a major component of the bacterial exometabolome, and the mechanisms for its wide-ranging effects on bacterial physiology are biomedically significant, although they remain poorly understood. Here, we determined how indole modulates the functions of a widely conserved motility apparatus, the bacterial flagellum. Our experiments in Escherichia coli revealed that indole influences the rotation rates and reversals in the flagellum's direction of rotation via multiple mechanisms. At concentrations higher than 1 mM, indole decreased the membrane potential to dissipate the power available for the rotation of the motor that operates the flagellum. Below 1 mM, indole did not dissipate the membrane potential. Instead, experiments and modeling indicated that indole weakens cooperative protein interactions within the flagellar complexes to inhibit motility. The metabolite also induced reversals in the rotational direction of the motor to promote a weak chemotactic response, even when the chemotaxis response regulator, CheY, was lacking. Experiments further revealed that indole does not require the transporter Mtr to cross the membrane and influence motor functions. Based on these findings, we propose that indole modulates intra- and inter-protein interactions in the cell to influence several physiological functions.

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