Atomic force microscopy analysis of Pel polysaccharide- and type IV pili-mediated adhesion of Pseudomonas aeruginosa PA14 to an abiotic surface.

Type IV pili (TFP) contribute to the ability of microbes such as Pseudomonas aeruginosa to engage with and move across surfaces. We reported previously that P. aeruginosa TFP generate retractive forces of ∼30 pN and provided indirect evidence that TFP-mediated surface attachment was enhanced in the presence of the Pel polysaccharide. Here, we use different mutants defective in flagellar, Pel production or TFP production - alone or in combination - to decipher the relative contribution of these biofilm-promoting factors for P. aeruginosa adhesion. By means of atomic force microscopy (AFM), we show that mutating the flagellum (ΔflgK mutant) results in an increase in Pel polysaccharide production, but this increase in Pel does not result in an increase in surface adhesive properties compared to those previously described for the WT strain. By blocking Pel production in the ΔflgK mutant (ΔflgKΔpel), we directly show that TFP play a major role in the adhesion of the bacteria to hydrophobic AFM tips, but that the adhesion force is only slightly impaired by the absence of Pel. Inversely, performing single-cell force spectroscopy measurements with the mutant lacking TFP (ΔflgKΔpilA) reveals that the Pel can modulate the attachment of the bacteria to a hydrophobic substrate in a time-dependent manner. Finally, little adhesion was detected for the ΔflgKΔpilAΔpelA triple mutant, suggesting that both TFP and Pel polysaccharide make a substantial contribution to bacteria-substratum interaction events. Altogether, our data allow us to decipher the relative contribution of Pel and TFP in the early attachment by P. aeruginosa.

Neuromuscular ultrasound findings in gunshot wounds.

INTRODUCTION/AIMS: A spectrum of peripheral nerve injuries is associated with gunshot wounds (GSWs). Due to Wallerian degeneration, distal nerve lesions may go undetected on electrodiagnostic (EDX) testing. In patients with GSW undergoing high-resolution ultrasound (HRUS) for evaluation of neurological deficits, we have observed distal nerve morphological changes, but these have not been systematically studied. The aim of this study was to characterize changes on HRUS in nerves at and distal to gunshot injuries and to identify the frequency with which these changes occur. METHODS: A retrospective cohort study was performed on patients referred for HRUS with peripheral nerve injuries from GSW. The primary injured nerve(s) were assessed along with distal segments of the same nerve and those of adjacent nerves. Findings were also compared to EDX studies. RESULTS: Twenty-two of the 28 nerves injured proximally by GSW were evaluated distally and of these, 68% showed abnormal ultrasound findings, including enlarged cross sectional area (59%), fascicular enlargement (50%), and decreased nerve echogenicity (59%). In 17 patients, adjacent nerves were evaluated and 8 of the patients (47%) showed abnormalities in at least one distal adjacent nerve, including enlarged cross sectional area (41%), fascicular enlargement (41%), and decreased nerve echogenicity (35%). DISCUSSION: This study demonstrated morphological changes at the site of the GSW but also in distal nerve segments including nerve enlargement, fascicular enlargement, and changes in nerve echogenicity. The complementary use of HRUS with EDX was highlighted in evaluation of GSW victims to assess the extent of peripheral nerve injury.

Anomalous Flexor Digitorum Superficialis Muscle Belly Associated with Carpal Tunnel Syndrome.

Anomalous muscle bellies in the forearm generally are asymptomatic and appreciated in an academic sense during cadaveric dissections. Few prior anatomic variations in muscle bellies have been described with symptoms, and are associated even more rarely with carpal tunnel syndrome (CTS). We discuss the evaluation and management of a case of CTS associated with a muscle belly of the flexor digitorum superficialis to the index within the carpal tunnel.

Association between diabetic peripheral neuropathy and sarcopenia: A systematic review and meta-analysis.

AIM: The present study comprehensively investigated the relationship between diabetic peripheral neuropathy (DPN) and sarcopenia by identifying all eligible studies and summarizing their results. METHODS: Records were identified through MEDLINE and EMBASE database searching from inception to March 9, 2022. We included all cross-sectional studies investigating the association between DPN and sarcopenia among patients with diabetes. Data from eligible studies, including point estimates and standard errors, were pooled together using the generic inverse variance method. RESULTS: Of 2989 retrieved articles, five studies met the inclusion criteria and were allowed for meta-analysis. The pooled analysis found a significant association between DPN and sarcopenia with the pooled odds ratio of 1.62 (95% confidence interval: 1.30-2.02; I2 0%). The funnel plot was relatively symmetric and was not suggestive of the presence of publication bias. CONCLUSIONS: The current study discovered a significant association between DPN and sarcopenia in patients with diabetes. However, given summarized data from cross-sectional studies, the temporality between DPN and sarcopenia could not be established. Geriatr Gerontol Int 2022; 22: 785-789.

High-risk Disease and Poor Follow-up: The Importance of Renal Mass Biopsy in a Cohort of Veterans.

OBJECTIVE: To assess the clinical utility of renal mass biopsy (RMB) in our multistate system. RMB is useful in the management of masses ≤4 cm (T1a), but evaluation of RMB in the uniquely vulnerable Veteran population is lacking. METHODS: About 136 RMB in 130 patients performed between 06/2015 and 11/2020 were identified in this Quality Improvement analysis. Demographics, size, pathology, treatment, and biopsy complications were analyzed. Of 101 T1a masses, 89 were either diagnostic or not decompressed cysts and 77 met inclusion criteria for follow-up imaging compliance analysis. RESULTS: The median age was 66 years. The diagnostic rate was 94.1% (128/136) for all masses and 94.1% (95/101) for T1a renal masses, with a complication rate of 2.2%. Among solid T1a masses, unexpectedly aggressive lesions (Fuhrman Grade 4, Type 2 papillary or sarcomatoid features) were identified in 8/89 (9.0%). Fifty-seven (64%) patients were treated with cryoablation or surgery and 32 (36%) patients elected active surveillance (AS). A neoplastic finding (oncocytoma or renal cell carcinoma (RCC)) was present in 16 patients choosing AS (50%) compared to 52 patients choosing treatment (91%). Compliance with National Comprehensive Cancer Network-recommended imaging was 50% and 47% for AS and treatment groups, respectively. CONCLUSION: In this VA cohort, we found a significant incidence of high-risk lesions and poor compliance with follow-up imaging. Aggressive biopsy protocols with high consideration of treatment may be appropriate to limit risk in those lost to follow-up. Given that 9% of our small renal masses were highly aggressive, biopsy may be critical in the selection of AS candidates.

Nonmotile Subpopulations of Pseudomonas aeruginosa Repress Flagellar Motility in Motile Cells through a Type IV Pilus- and Pel-Dependent Mechanism.

The downregulation of Pseudomonas aeruginosa flagellar motility is a key event in biofilm formation, host colonization, and the formation of microbial communities, but the external factors that repress motility are not well understood. Here, we report that on soft agar, swarming motility can be repressed by cells that are nonmotile due to the absence of a flagellum or flagellar rotation. Mutants that lack either flagellum biosynthesis or rotation, when present at as little as 5% of the total population, suppressed swarming of wild-type cells. Non-swarming cells required functional type IV pili and the ability to produce Pel exopolysaccharide to suppress swarming by the flagellated wild type. Flagellated cells required only type IV pili, but not Pel production, for their swarming to be repressed by non-flagellated cells. We hypothesize that interactions between motile and nonmotile cells may enhance the formation of sessile communities, including those involving multiple genotypes, phenotypically diverse cells, and perhaps other species. IMPORTANCE Our study shows that, under the conditions tested, a small population of non-swarming cells can impact the motility behavior of a larger population. The interactions that lead to the suppression of swarming motility require type IV pili and a secreted polysaccharide, two factors with known roles in biofilm formation. These data suggest that interactions between motile and nonmotile cells may enhance the transition to sessile growth in populations and promote interactions between cells with different genotypes.

Care planning priorities of older patients with advanced bladder cancer.

OBJECTIVES: Advanced bladder cancer (ABC) disproportionately affects older adults, and little is known about older patients' priorities for care planning in advanced cancer. Patient-centered communication remains crucial to shared decision-making between patients, families, and providers. Yet, older patients with cancer may not always know how to express their preferences, and oncologists do not always review patients' informational needs. This study aimed to understand preferences of older patients with ABC related to their communication with providers and navigation of care planning. MATERIALS AND METHODS: This qualitative descriptive study involved in-depth interviews and focus groups with older patients with ABC and their care partners, which explored their priorities for care planning and communication with providers, decision-making processes, and valued traits in ABC care. Data were analyzed using thematic analysis. RESULTS: Ten participants attended focus groups or interviews. Seven patients were male and three care partners were female. The mean age was 74. Time since ABC diagnosis ranged from three to seventeen months. Four key themes illustrate participants' priorities in their ABC care as older adults: 1. The significance of key phrasing in communication from oncologists, 2. The need for clear expectation-setting about prognosis and treatment, 3. The role of others in patient care decisions, and 4. Valued traits in care communication. CONCLUSION: Older patients with ABC and their care partners are active participants in their care. Oncologists should prioritize setting clear expectations for treatment, involving family in care planning, and communicating honestly about expected changes to quality of life and functional status.

Residual symptoms and long-term outcomes after all-cause autoimmune encephalitis in adults.

BACKGROUND AND OBJECTIVES: To evaluate residual symptoms after all-cause autoimmune encephalitis in a real-life outpatient setting and compare long-term outcome measures. A secondary objective was to identify correlates of poor outcomes. METHODS: We analyzed patients referred to the Neuroimmunology clinic for evaluation of autoimmune encephalitis for whom standardized data were collected. We compared the prevalence of symptoms at the latest follow-up to presentation and calculated symptom improvement rates. We compared the Modified Rankin Scale (mRS) to the Clinical Assessment Scale for Autoimmune Encephalitis (CASE). Non-parametric Wilcoxon rank sum tests and Fisher's exact tests were used to compare clinical attributes between patients with and without poor outcomes. RESULTS: We evaluated 54 patients from 2017 to 2021 of whom 33 met inclusion criteria (average age 47±20 years, 57% females, 55% seropositive). By latest follow-up, 94% improved compared to presentation but six patients (18%) had poor outcomes as defined by an mRS ≥3. The most common residual symptoms were cognitive and mood dysfunction. The highest improvement rates were in alertness and psychosis while the lowest were in motor function and ataxia. CASE had moderate correlation with mRS (r2 = 0.53 [95%CI:0.23,0.74, p = 0.0015) but it captured more nuances than mRS at both presentation and follow-up. Older age and higher post-treatment CASE score correlated with poor outcomes. DISCUSSION: Most autoimmune encephalitis patients experience symptom improvement post-treatment. The CASE score was more representative of the wide symptomatic spectrum of autoimmune encephalitis and correlated with poor outcomes. However, CASE did not capture patients with dysautonomia, sleep dysfunction, or death.

Removal of Toxic Volatile Compounds in Batch Culture Prolongs Stationary Phase and Delays Death of Escherichia coli.

The mechanisms controlling entry into and exit from the death phase in the bacterial life cycle remain unclear. Although bacterial growth studies in batch cultures traditionally focus on the first three phases during incubation, two additional phases, the death phase and the long-term stationary phase, are less understood. Although there are a number of stressors that arise during long-term batch culture, including nutrient depletion and the accumulation of metabolic toxins such as reactive oxidative species, their roles in cell death are not well-defined. By manipulating the environmental conditions of Escherichia coli incubated in long-term batch culture through chemical and mechanical means, we investigated the role of volatile metabolic toxins in modulating the onset of the death phase. Here, we demonstrate that with the introduction of substrates with high binding affinities for volatile compounds, toxic by-products of normal cell metabolism, into the headspace of batch cultures, cells display a prolonged stationary phase and delayed entry into the death phase. The addition of these substrates allows cultures to maintain a high cell density for hours to days longer than cultures incubated under standard growth conditions. A similar effect is observed when the gaseous headspace in culture flasks is continuously replaced with sterile air, mechanically preventing the accumulation of metabolic by-products in batch cultures. We establish that toxic compound(s) are produced during the exponential phase, demonstrate that buildup of toxic by-products influence entry into the death phase, and present a novel tool for improving high-density growth in batch culture that may be used in future research or industrial or biotechnology applications. IMPORTANCE Bacteria, such as Escherichia coli, are routinely used in the production of biomaterials because of their efficient and sustainable capacity for synthesis of bioproducts. Industrial applications of microbial synthesis typically utilize cells in the stationary phase, when cultures have the greatest density of viable cells. By manipulating culture conditions to delay the transition from the stationary phase to the death phase, we can prolong the stationary phase on a scale of hours to days, thereby maintaining the maximum density of cells that would otherwise quickly decline. Characterization of the mechanisms that control entry into the death phase for the model organism E. coli not only deepens our understanding of the bacterial life cycle but also presents an opportunity to enhance current protocols for batch culture growth and explore similar effects in a variety of widely used bacterial strains.

Prostate Cancer in Older Adults: Risk of Clinically Meaningful Disease, the Role of Screening and Special Considerations.

PURPOSE OF REVIEW: Prostate cancer is the second most common cancer in men in the USA and several studies suggest more aggressive disease in older patients. However, screening remains controversial, especially in the older patient population. RECENT FINDINGS: Aggressive prostate cancers are more common in older men. Screening trial results are conflicting but data suggest an improvement in prostate cancer mortality and increased detection of metastatic disease with screening. When PSA is utilized with multiparametric MRI and biomarker assays, patients at significant risk of clinically meaningful prostate cancer can be appropriately selected for biopsy. A thoughtful and individualized approach is central when considering prostate cancer screening in older men. This approach includes life expectancy estimation, use of appropriate geriatric assessment tools, use of multiparametric MRI and biomarkers in addition to PSA, and most importantly shared decision-making with patients.

Treating Elderly Patients With Muscle-Invasive Bladder Cancer.

Bladder cancer is an extremely common cancer that primarily affects individuals aged >65 years. In caring for patients with bladder cancer, clinicians must also consider care of older persons in general. Management of muscle-invasive bladder cancer (MIBC) involves multidisciplinary treatment planning, because curative-intent therapy includes either surgery or radiation, with consideration of the role of systemic therapy. As clinicians develop a treatment plan, considering a geriatric oncology perspective may enhance patient care and influence outcomes for this large and growing population. Similarly, treatment plan development must also consider aspects unique to an older patient population, such as altered organ function, increased comorbidity, decreased functional reserve, and perhaps altered goals of treatment. Thus a thorough evaluation inclusive of disease assessment and geriatric assessment is essential to care planning. Population-based data show that as patients with MIBC age, use of standard therapies declines. Given the complexities of coordinating a multidisciplinary care plan, as well the complexities of treating a heterogeneous and potentially vulnerable older patient population, clinicians may benefit from upfront assessments to inform and guide the process. This review highlights the unique treatment planning considerations for elderly patients diagnosed with MIBC.

Adaptation of Escherichia coli to Long-Term Serial Passage in Complex Medium: Evidence of Parallel Evolution.

Experimental evolution of bacterial populations in the laboratory has led to identification of several themes, including parallel evolution of populations adapting to carbon starvation, heat stress, and pH stress. However, most of these experiments study growth in defined and/or constant environments. We hypothesized that while there would likely continue to be parallelism in more complex and changing environments, there would also be more variation in what types of mutations would benefit the cells. In order to test our hypothesis, we serially passaged Escherichia coli in a complex medium (Luria-Bertani broth) throughout the five phases of bacterial growth. This passaging scheme allowed cells to experience a wide variety of stresses, including nutrient limitation, oxidative stress, and pH variation, and therefore allowed them to adapt to several conditions. After every ~30 generations of growth, for a total of ~300 generations, we compared both the growth phenotypes and genotypes of aged populations to the parent population. After as few as 30 generations, populations exhibit changes in growth phenotype and accumulate potentially adaptive mutations. There were many genes with mutant alleles in different populations, indicating potential parallel evolution. We examined 8 of these alleles by constructing the point mutations in the parental genetic background and competed those cells with the parent population; five of these alleles were found to be adaptive. The variety and swiftness of adaptive mutations arising in the populations indicate that the cells are adapting to a complex set of stresses, while the parallel nature of several of the mutations indicates that this behavior may be generalized to bacterial evolution. IMPORTANCE With a growing body of work directed toward understanding the mechanisms of evolution using experimental systems, it is crucial to decipher what effects the experimental setup has on the outcome. If the goal of experimental laboratory evolution is to elucidate underlying evolutionary mechanisms and trends, these must be demonstrated in a variety of systems and environments. Here, we perform experimental evolution in a complex medium allowing the cells to transition through all five phases of growth, including death phase and long-term stationary phase. We show that the swiftness of selection and the specific targets of adaptive evolution are different in this system compared to others. We also observe parallel evolution where different mutations in the same genes are under positive natural selection. Together, these data show that while some outcomes of microbial evolution experiments may be generalizable, many outcomes will be environment or system specific.

The Human Experience with Intravenous Levodopa.

OBJECTIVE: To compile a comprehensive summary of published human experience with levodopa given intravenously, with a focus on information required by regulatory agencies. BACKGROUND: While safe intravenous (IV) use of levodopa has been documented for over 50 years, regulatory supervision for pharmaceuticals given by a route other than that approved by the U.S. Food and Drug Administration (FDA) has become increasingly cautious. If delivering a drug by an alternate route raises the risk of adverse events, an investigational new drug (IND) application is required, including a comprehensive review of toxicity data. METHODS: Over 200 articles referring to IV levodopa were examined for details of administration, pharmacokinetics, benefit, and side effects. RESULTS: We identified 142 original reports describing IVLD use in humans, beginning with psychiatric research in 1959-1960 before the development of peripheral decarboxylase inhibitors. At least 2760 subjects have received IV levodopa, and reported outcomes include parkinsonian signs, sleep variables, hormone levels, hemodynamics, CSF amino acid composition, regional cerebral blood flow, cognition, perception and complex behavior. Mean pharmacokinetic variables were summarized for 49 healthy subjects and 190 with Parkinson's disease. Side effects were those expected from clinical experience with oral levodopa and dopamine agonists. No articles reported deaths or induction of psychosis. CONCLUSION: At least 2760 patients have received IV levodopa with a safety profile comparable to that seen with oral administration.

Spiral and vestibular ganglion estimates in archival temporal bones obtained by design based stereology and Abercrombie methods.

The objective of this study was to make direct comparisons of the estimates of spiral and vestibular neuronal number in human archival temporal bone specimens using design-based stereology with those using the assumption-based Abercrombie method. Archival human temporal bone specimens from subjects ranging in age from 16 to 80 years old were used. The number of spiral and vestibular ganglia neurons within the counting areas was estimated using the stereology-optical disector technique and compared with estimates obtained using the assumption-based Abercrombie method on the same specimens. Using the optical disector method, there was an average of 41,480 (coefficient of variation=0.12) spiral ganglia neurons and 28,930 (coefficient of variation=0.15) vestibular ganglia neurons. The mean coefficient of error was 0.076 for the spiral ganglion estimates, and 0.091 for the vestibular ganglion estimates. Using the Abercrombie correction method of two-dimensional analysis, an average of 23,110 (coefficient of variation of 0.08) spiral ganglia neurons, and 16,225 vestibular ganglia neurons (coefficient of variation of 0.15) was obtained. We found that there was a large disparity between the estimates with a significant 44% underestimation of the spiral and vestibular ganglion counts obtained using the Abercrombie method when compared with estimates using the optical disector method.