Bacterial respiratory inhibition triggers dispersal of Pseudomonas aeruginosa biofilms.

Pseudomonas aeruginosa grows as a biofilm under many environmental conditions, and the bacterium can disperse from biofilms via highly regulated, dynamic processes. However, physiologic triggers of biofilm dispersal remain poorly understood. Based on prior literature describing dispersal triggered by forms of starvation, we tested bacterial respiratory inhibitors for biofilm dispersal in two models resembling chronic airway infections. Our underlying hypothesis was that respiratory inhibitors could serve as a model for the downstream effects of starvation. We used two experimental conditions. In the first condition, biofilms were grown and dispersed from the surface of airway epithelial cells, and the second condition was a model where biofilms were grown on glass in cell culture media supplemented with host-relevant iron sources. In both biofilm models, the respiratory inhibitors potassium cyanide and sodium azide each triggered biofilm dispersal. We hypothesized that cyanide-induced dispersal was due to respiratory inhibition rather than signaling via an alternative mechanism, and, indeed, if respiration was supported by overexpression of cyanide-insensitive oxidase, dispersal was prevented. Dispersal required the activity of the cyclic-di-GMP regulated protease LapG, reinforcing the role of matrix degradation in dispersal. Finally, we examined the roles of individual phosphodiesterases, previously implicated in dispersal to specific triggers, and found signaling to be highly redundant. Combined deletion of the phosphodiesterases dipA, bifA, and rbdA was required to attenuate the dispersal phenotype. In summary, this work adds insight into the physiology of biofilm dispersal under environmental conditions in which bacterial respiration is abruptly limited. IMPORTANCE The bacterium Pseudomonas aeruginosa grows in biofilm communities that are very difficult to treat in human infections. Growing as a biofilm can protect bacteria from antibiotics and the immune system. Bacteria can leave a biofilm through a process called "dispersal." Dispersed bacteria seed new growth areas and are more susceptible to killing by antibiotics. The triggers for biofilm dispersal are not well understood, and if we understood dispersal better it might lead to the development of new treatments for infection. In this paper, we find that inhibiting P. aeurginosa's ability to respire (generate energy) can trigger dispersal from a biofilm grown in association with human respiratory epithelial cells in culture. The dispersal process requires a protease which is previously known to degrade the biofilm matrix. These findings give us a better understanding of how the biofilm dispersal process works so that future research can discover better ways of clearing bacteria growing in biofilms.

The effect of a high-selenium lentil diet on cardiovascular risk markers in an arsenic-exposed population.

Chronic arsenic exposure is associated with a number of systemic diseases, including cardiovascular disease. Selenium has been shown to promote arsenic excretion from the body. We investigated if a high-selenium lentil diet has an effect on blood pressure and plasma lipid levels in an arsenic-exposed population by conducting a 6-month randomized controlled dietary intervention trial with 405 participants.

Spinal Anesthesia Using Ropivacaine Leads to Earlier Ambulation After Total Hip Arthroplasty.

Spinal anesthesia has grown in popularity for total hip arthroplasty (THA) due to its documented low complications. However, the use of a local anesthetic agent dictates the recovery of neuraxial blockade. Bupivacaine has emerged as the most popular choice, but its relatively long-acting effect limits its use with rapid recovery. Although not well studied, ropivacaine may offer a viable alternative with shorter-acting properties. Primary unilateral THA patients who received either ropivacaine or bupivacaine spinal anesthesia were retrospectively reviewed. These groups were compared for common demographics, such as age, sex, and body mass index. The primary outcomes included postoperative ambulation time and distance, post-anesthesia care unit transition time, and selective complications. Five hundred three patients were included. Of these, 227 received ropivacaine and 276 received bupivacaine. The ropivacaine group showed superior ambulation time and distance, quicker post-anesthesia care unit transition, and equivalent complications compared with the bupivacaine group. Ropivacaine shows a clear advantage over bupivacaine for spinal anesthesia during THA when considering rapid recovery. Its use should be strongly considered, especially in the ambulatory setting. [Orthopedics. 2021;44(3):e343-e346.].

Addressing Common Challenges in the Implementation of Collaborative Care for Mental Health: The Penn Integrated Care Program.

PURPOSE: We developed and implemented a new model of collaborative care that includes a triage and referral management system. We present initial implementation metrics using the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework. METHODS: Primary care clinicians in 8 practices referred patients with any unmet mental health needs to the Penn Integrated Care program. Assessments were conducted using validated measures. Patients were primarily triaged to collaborative care (26%) or specialty mental health care with active referral management (70%). We conducted 50 qualitative interviews to understand the implementation process and inform program refinement. Our primary outcomes were reach and implementation metrics, including referral and encounter rates derived from the electronic health record. RESULTS: In 12 months, 6,124 unique patients were referred. Assessed patients reported symptoms consistent with a range of conditions from mild to moderate depression and anxiety to serious mental illnesses including psychosis and acute suicidal ideation. Among patients enrolled in collaborative care, treatment entailed a mean of 7.2 (SD 5.1) encounters over 78.1 (SD 51.3) days. Remission of symptoms was achieved by 32.6% of patients with depression and 39.5% of patients with anxiety. Stakeholders viewed the program favorably and had concrete suggestions to ensure sustainability. CONCLUSIONS: The Penn Integrated Care program demonstrated broad reach. Implementation was consistent with collaborative care as delivered in seminal studies of the model. Our results provide insight into a model for launching and implementing collaborative care to meet the needs of a diverse group of patients with the full range of mental health conditions seen in primary care.

Chemical composition and cytotoxic properties of Clinacanthus nutans root extracts.

CONTEXT: Clinacanthus nutans Lindau (Acanthaceae) is a medicinal plant that has been reported to have anti-inflammatory, antiviral, antimicrobial and antivenom activities. In Malaysia, it has been widely claimed to be effective in various cancer treatments but scientific evidence is lacking. OBJECTIVE: This study investigates the chemical constituents, anti-proliferative, and apoptotic properties of C. nutans root extracts. MATERIALS AND METHODS: The roots were subjected to solvent extraction using methanol and ethyl acetate. The anti-proliferative effects of root extracts were tested at the concentrations of 10 to 50 µg/mL on MCF-7 and HeLa by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for 72 h. Morphological changes were observed under light microscope. Pro-apoptotic effects of root extracts were examined using flow cytometric analysis and RT-PCR. The chemical compositions of root extracts were detected using GC-MS. RESULTS: The proliferation of MCF-7 cells was inhibited with the IC50 values of 35 and 30 µg/mL, respectively, for methanol and ethyl acetate root extracts. The average inhibition of HeLa cells was ∼25%. Induction of apoptosis in MCF-7 was supported by chromatin condensation, down-regulation of BCL2 and unaltered expression of BAX. However, only ethyl acetate extract caused the loss of mitochondrial membrane potential. GC-MS analysis revealed the roots extracts were rich with terpenoids and phytosterols. DISCUSSION AND CONCLUSIONS: The results demonstrated that root extracts promote apoptosis by suppressing BCL2 via mitochondria-dependent or independent manner. The identified compounds might work solely or cooperatively in regulating apoptosis. However, further studies are required to address this.

Does the Chemical Diversity of the Order Haplosclerida (Phylum Porifera: Class Demospongia) Fit with Current Taxonomic Classification?

Sponges and their associated microbiota are well known to produce a large diversity of natural products, also called specialized metabolites. In addition to their potential use in the pharmaceutical industry, these rather species-specific compounds may help in the classification of some particular sponge groups. We review herein compounds isolated from haplosclerid sponges (Class Demospongia, Order Haplosclerida) in order to help in the revision of this large group of marine invertebrates. We focus only on 3-alkylpyridine derivatives and polyacetylenic compounds, as these two groups of natural products are characteristic of haplosclerid species and are highly diverse. A close collaboration between chemists and biologists is required in order to fully apply chemotaxonomical approaches, and whenever possible biological data should include morphological and molecular data and some insight into their microbial abundance.

The application of participatory ergonomics in a healthcare setting in Hong Kong.

BACKGROUND: Work-related musculoskeletal disorders (WRMDs) are recognized as a major source of significant pain and disability in the healthcare sector. However, they are preventable if appropriate surveillance and intervention programs are implemented. OBJECTIVE: The purpose of this paper is to describe the holistic ergonomic approach that was used to address the multifactorial problems encountered by healthcare workers in their daily work. METHODS: Using participatory ergonomics, healthcare workers in this study teamed up with management and staff with expertise in ergonomic analysis, design, and implementation of remedies. Selected participatory ergonomic intervention programs targeted at an organizational level are elaborated. Interventions included pre-work stretching, workplace surveillance at a psychiatric department, on-site ergonomic teaching for community nurses, and display screen equipment consultancy. DISCUSSIONS: Changes in workplace design, equipment re-arrangement, awareness of proper posture, and adoption of good work practices all play important roles in reducing musculoskeletal disorders among healthcare workers. Prompt occupational medicine and rehabilitation services were also provided to complement the work disability prevention process. The impact of the various intervention programs on staff health, costs and productivity of the organization are simultaneously discussed.

In a time of cholera.

INTRODUCTION: Dr. Nathaniel Alcock in his book A treatise on cholera described 22 cases of cholera that he treated in 1832. Blood-letting, either by leeches or venesection, was an essential part of the treatment. RATIONALE: The belief was that reducing the blood volume would relieve stress on the heart and lungs allowing for better function. The receipts of the Townsend Street Cholera Hospital where Dr. Alcock worked show how extensive the practice was. Outside Dublin, local Boards of Health dealt with the cholera epidemic. Various public measures such as street cleaning and removal of patients to temporary hospitals were undertaken and various cures were tried. OUTCOME: The overall mortality rate from cholera in Ireland during the epidemic was 38 %, but in some areas much higher. CONCLUSION: Even as cholera was spreading in the 1830s, a number of doctors were showing that intravenous fluids could dramatically alter the course of the disease. Unfortunately, their work was ignored and blood-letting continued to be a major component of the treatment of cholera for another 55 years.

Comparing biofeedback with active exercise and passive treatment for the management of work-related neck and shoulder pain: a randomized controlled trial.

OBJECTIVES: To compare the effects of biofeedback with those of active exercise and passive treatment in treating work-related neck and shoulder pain. DESIGN: A randomized controlled trial with 3 intervention groups and a control group. SETTING: Participants were recruited from outpatient physiotherapy clinics and a local hospital. PARTICIPANTS: All participants reported consistent neck and shoulder pain related to computer use for more than 3 months in the past year and no severe trauma or serious pathology. A total of 72 potential participants were recruited initially, of whom a smaller group of individuals (n=60) completed the randomized controlled trial. INTERVENTIONS: The 3 interventions were applied for 6 weeks. In the biofeedback group, participants were instructed to use a biofeedback machine on the bilateral upper trapezius (UT) muscles daily while performing computer work. Participants in the exercise group performed a standardized exercise program daily on their own. In the passive treatment group, interferential therapy and hot packs were applied to the participants' necks and shoulders. The control group was given an education booklet on office ergonomics. MAIN OUTCOME MEASURES: Pain (visual analog scale), neck disability index (NDI), and surface electromyography were assessed preintervention and postintervention. Pain and NDI were reassessed after 6 months. RESULTS: Postintervention, average pain and NDI scores were reduced significantly more in the biofeedback group than in the other 3 groups, and this was maintained at 6 months. Cervical erector spinae muscle activity showed significant reductions postintervention in the biofeedback group, and there were consistent trends of reductions in the UT muscle activity. CONCLUSIONS: Six weeks of biofeedback training produced more favorable outcomes in reducing pain and improving muscle activation of neck muscles in patients with work-related neck and shoulder pain.

Occupational rehabilitation in Singapore and Malaysia.

INTRODUCTION: Asia is the new and favored magnet of economic attention and foreign investments after it made an almost uneventful rebound from the depths of financial crisis of 2008/2009. Not many Western observers fully understand the diversity that is Asia other than perhaps its 2 growing economic giants of China and India. Indeed many smaller countries like Singapore and Malaysia in South East Asia along with Australia and Hong Kong (a Special Administrative Region within China) look to symbiotic relationships with these two economic giants. The purpose of this discussion paper is to examine the current issues related to the development and provision of occupational rehabilitation services in Singapore and Malaysia with a forward-looking view of how Asia's different developing societies could potentially benefit from better alignment of occupational rehabilitation practices and sharing of expertise through international collaboration and dialogue platforms. METHODS: Seven therapists and one physician who are frequently involved in occupational rehabilitation services in their home countries critically reviewed the current issues in Singapore and Malaysia which included analysis of the prevalence and cost of occupational injury; overview of workers' compensation system; current practices, obstacles, and challenges in providing occupational rehabilitation and return to work practices. They also offered opinions about how to improve the occupational rehabilitation programs of their two home countries. CONCLUSION: Even though Malaysia and Singapore are two different countries, in many ways their current provision of occupational rehabilitation services and the problems they face with are very similar. There is a lot of room for systemic improvements that require government support and action. Most prominently, the training of more healthcare professionals in the assessment and rehabilitation of the injured worker should be encouraged. There could be better liaison between the many stakeholders and more funding made available to develop resources and to jump start strategic programs. As these two countries are witnessing rapid economic growth, more resources should be allocated to establish holistic care of the injured workers emphasizing early interventions and prevention of chronic disabilities.

Baseline urinary phytoestrogen levels and the natural history of untreated, localised prostate cancer in a British population.

AIM: To determine whether urinary concentrations of phytoestrogens are associated with the rate of disease progression in men with untreated, localised prostate cancer. PATIENTS AND METHODS: Patients with untreated, localised prostatic adenocarcinoma on a prospective clinical study of active surveillance had urine samples collected at baseline. Patients underwent monitoring with serial PSA levels and repeat octant prostate biopsies. Disease progression was defined as either adverse histology on repeat biopsy (primary Gleason grade >or= 4, or >50% positive cores) or radical treatment for PSA velocity >1 ng/mL/year. Time to disease progression was analysed with respect to baseline urinary levels of genistein, enterolactone, daidzein and equol, assayed using liquid chromatography/tandem mass spectrometry. RESULTS: 191 patients were evaluable, with a median follow-up of 2.5 years. 71 patients experienced disease progression. No significant association was seen between time to disease progression and baseline urinary levels of daidzein (p=0.85), genistein (p=0.81), enterolactone (p=0.085) or equol (p=0.33). No significant association was seen between adverse histology on repeat biopsy and urinary levels of either daidzein (p=0.85), genistein (p=0.58), enterolactone (p=0.88) or equol (p=0.71). There was no significant correlation between PSA velocity and urinary levels of daidzein (p=0.90), genistein (p=0.98), enterolactone (p=0.10) or equol (p=0.60). CONCLUSION: These data do not support the hypothesis that phytoestrogens prevent disease progression in men with localised prostate cancer.

Hyperbaric oxygen inhibits benign and malignant human mammary epithelial cell proliferation.

BACKGROUND: Hyperbaric oxygenation (HBO) therapy is the administration of 100%-inhaled oxygen to patients at increased atmospheric pressure. MATERIALS AND METHODS: We used an in vitro model to examine the effects of HBO on mammary cell proliferation. Normal mammary epithelia, primary tumor and metastatic tumor cells derived from the same patient and immortalized by transfection with the human papilloma virus E6 oncogene, as well as the MCF7 human mammary adenocarcinoma cell line, were studied. RESULTS: HBO (97.9% O2, 2.1% CO2, 2.4 atmospheres absolute) inhibited the proliferation of all 4 cell types as measured by light microscopy, [3H]thymidine uptake, a tetrazolium-based colorimetric assay and a clonogenicity assay. The anti-proliferative effect of HBO was time-dependent (p < 0.01 for all 4 cell types). Hyperoxia alone (95% O2, 5% CO2, 1 atmosphere absolute) and increased atmospheric pressure alone (8.75% O2, 2.1% CO2, 2.4 atmospheres absolute) also inhibited proliferation, but their effects were not as profound as HBO (p < 0.01 when either hyperoxia or increased pressure was compared to HBO for all 4 cell types). HBO enhanced the anti-proliferative effects of melphalan (p < 0.05), gemcitabine (p < 0.001) and paclitaxel (p < 0.001). The clonogenicity assay demonstrated that the effects of HBO were still evident 2 weeks after the exposure (p < 0.01 for all 4 cell types). Experiments using Hoechst-propidium iodide or annexin V-propidium iodide staining showed no HBO-induced increases in necrosis or apoptosis. CONCLUSION: HBO inhibits benign and malignant mammary epithelial cell proliferation, but does not enhance cell death.

Concomitant clotrimazole therapy more than doubles the relative oral bioavailability of tacrolimus.

The purpose of this pharmacokinetic study was to determine whether the relative oral bioavailability of tacrolimus is increased with concomitant administration of clotrimazole. Pharmacokinetic studies were conducted in 6 adult kidney transplant patients receiving tacrolimus therapy. Pharmacokinetic profiling was performed by blood sampling over 12 hours before and after the administration of a 5-day course of clotrimazole. Tacrolimus whole-blood concentrations were determined by microparticle enzyme immunoassay. Noncompartmental pharmacokinetic analysis was conducted using WinNonLin, Standard Edition, Version 1.1. Concomitant administration of clotrimazole more than doubled the relative oral bioavailability of tacrolimus. The mean AUC0-12 of tacrolimus was increased 250% with clotrimazole (467.0 +/- 170.0 ng.h/mL versus 188.7 +/- 50.2 ng.h/mL; P = 0.002). Tacrolimus blood trough concentrations also more than doubled with coadministration of clotrimazole (27.7 +/- 10.4 ng/mL versus 11.6 +/- 4.0 ng/mL; P = 0.003). Mean Cmax was significantly increased with clotrimazole (70.7 +/- 34.7 ng/mL versus 27.4 +/- 11.1 ng/mL, P = 0.01). Tmax decreased from 3.2 +/- 1.6 hours to 1.9 +/- 1.0 hours (P = NS). In addition, the apparent oral clearance decreased 60% with coadministration of clotrimazole (median oral clearance 0.16 L/h/kg versus 0.40 L/h/kg; P = 0.03). Thus, clotrimazole causes a significant increase in the relative oral bioavailability, Tmax, and trough concentration of tacrolimus. Tacrolimus levels should be monitored following initiation or discontinuation of clotrimazole to minimize toxicity or precipitation of an acute rejection episode due to subtherapeutic levels.

A review of technological approaches to venous ulceration.

Leg ulceration is a chronic condition affecting about 1-2% of the adult population. The main causes of leg ulceration are venous hypertension, arterial insufficiency, diabetes, or a combination of these aetiologies (causes) or malignancy. Venous ulcers account for approximately 80% of all leg ulcers and are a result of venous hypertension. The current mainstay of treatment of venous ulcers is the application of graduated compression bandaging to the limb. In spite of the application of the best evidence-based therapy, healing rates for venous leg ulcers remain disappointing, at 50-70% after 12 weeks of treatment, depending on initial size and chronicity of the ulcer. Thus, a large number of ulcers are unhealed by this time, and many patients suffer from long-term leg ulceration, some remaining for years, and those that heal often recur. There is an obvious need to develop new treatments that would improve healing rates. This review provides a complete overview of the anatomy of venous circulation and the physiology pertaining to it, the pathophysiology of venous disease, the pathogenesis of ulceration, and a review of treatments currently employed in healing venous leg ulcers and their supporting evidence. The aim of this article is to encourage a fresh look at this chronic problem and stimulate ideas on how healing rates can be improved.

An investigation of the effect of electrode size and electrode location on comfort during stimulation of the gastrocnemius muscle.

The use of surface neuromuscular electrical stimulation (SNMES) in medicine is well established. However, discomfort has been identified as limiting the use of SNMES in these applications. This pilot study investigated the influence of various electrode sizes and their positioning on perceived pain and discomfort during neuromuscular electrical stimulation (NMES) of the gastrocnemius muscle using surface electrodes. This study formed part of a research project to develop a therapeutic device for calf muscle blood flow assist applications. Twelve healthy subjects (n=12) participated in this pilot study. Each participant attended the trial centre for testing which consisted of SNMES to four different electrode stimulation sites using two electrode sizes (round with areas 19.63 and 38.48 cm2). Comfort was assessed by asking the subjects to indicate the stimulation amplitude corresponding to the onset of discomfort (pain threshold) and the amplitude at which the discomfort became unbearable (pain tolerance). Of the four stimulation sites tested, two were deemed unsuccessful as it was very difficult to obtain a muscle contraction using these sites, while the remaining two sites elicited good muscle contraction. The most comfortable stimulation was achieved by placing the cathode electrode high on the calf, below the proximal end of the muscle heads and the anode electrode towards the end of the muscle belly and when the 19.63 cm2 electrodes were used at these sites (p=<0.001).

Quadro clínico e classificação das dissecções aórticas / Aortic dissection: clinical picture and classification

Os autores fazem uma revisão da apresentação clínica da dissecção aórtica aguda, enfatizando a presença quase uniforme de dor precordial intensa. Na maioria dos casos os indivíduos afetados têm história de hipertensão arterial sistêmica. A presença concomitante de sinais ou sintomas diversos, como isquemia cerebral, mesentérica ou periférica, síncope, insuficiência aórtica e assimetria de pulsos, auxilia no encaminhamento diagnóstico. Apesar da intensidade da dor precordial, o eletrocardiograma pode ser normal ou demonstrar apenas sobrecarga ventricular esquerda com alterações secundárias de repolarização. Comparando os dados de uma população brasileira com os de Dublin (Irlanda) e do Registro Internacional de Dissecção Aórtica, verifica-se que, em nosso meio, a média de idade dos indivíduos acometidos de dissecção é significantemente menor, assim como é significantemente maior a prevalência de hipertensão arterial. As classificações dividem a dissecção em aguda (inferior a duas semanas) ou crônica no aspecto duração da doença, e em tipo A (envolvimento da aorta ascendente) ou B (envolvimento da aorta descendente) no aspecto anatômico. Essas classificações são práticas e objetivas por conciliarem aspectos diagnósticos, prognósticos e de conduta.