Development of infection prevention program standards for critical access hospitals.

Although critical access hospitals are small, the expected infection prevention activities remain extensive. Program standards, aligned with the Association for Professionals in Infection Control and Epidemiology infection prevention competency model domains, were developed and implemented in a midwestern health care system. Time estimates for completion of each activity were assigned and then extrapolated to offer guidance on necessary full-time equivalents for adequate staffing.

Outcomes of complex oncoplastic breast surgery in older women. Analysis of data from the Age Gap cohort study.

KEY WORDS: Breast cancer, mastectomy, breast conserving surgery, post-mastectomy reconstruction, older women, quality of life.

A Biopharmaceutical Perspective on Higher-Order Structure and Thermal Stability of mRNA Vaccines.

Preservation of the integrity of macromolecular higher-order structure is a tenet central to achieving biologic drug and vaccine product stability toward manufacturing, distribution, storage, handling, and administration. Given that mRNA lipid nanoparticles (mRNA-LNPs) are held together by an intricate ensemble of weak forces, there are some intriguing parallels to biologic drugs, at least at first glance. However, mRNA vaccines are not without unique formulation and stabilization challenges derived from the instability of unmodified mRNA and its limited history as a drug or vaccine. Since certain learning gained from biologic drug development may be applicable for the improvement of mRNA vaccines, we present a perspective on parallels and contrasts between the emerging role of higher-order structure pertaining to mRNA-LNPs compared to pharmaceutical proteins. In a recent publication, the location of mRNA encapsulated within lipid nanoparticles was identified, revealing new insights into the LNP structure, nanoheterogeneity, and microenvironment of the encapsulated mRNA molecules [Brader et al. Biophys. J. 2021, 120, 2766]. We extend those findings by considering the effect of encapsulation on mRNA thermal unfolding with the observation that encapsulation in LNPs increases mRNA unfolding temperatures.

A Systematic Review Examining the Experimental Methodology Behind In Vivo Testing of Hiatus Hernia and Diaphragmatic Hernia Mesh.

INTRODUCTION: Mesh implants are regularly used to help repair both hiatus hernias (HH) and diaphragmatic hernias (DH). In vivo studies are used to test not only mesh safety, but increasingly comparative efficacy. Our work examines the field of in vivo mesh testing for HH and DH models to establish current practices and standards. METHOD: This systematic review was registered with PROSPERO. Medline and Embase databases were searched for relevant in vivo studies. Forty-four articles were identified and underwent abstract review, where 22 were excluded. Four further studies were excluded after full-text review-leaving 18 to undergo data extraction. RESULTS: Of 18 studies identified, 9 used an in vivo HH model and 9 a DH model. Five studies undertook mechanical testing on tissue samples-all uniaxial in nature. Testing strip widths ranged from 1-20 mm (median 3 mm). Testing speeds varied from 1.5-60 mm/minute. Upon histology, the most commonly assessed structural and cellular factors were neovascularisation and macrophages respectively (n = 9 each). Structural analysis was mostly qualitative, where cellular analysis was equally likely to be quantitative. Eleven studies assessed adhesion formation, of which 8 used one of four scoring systems. Eight studies measured mesh shrinkage. DISCUSSION: In vivo studies assessing mesh for HH and DH repair are uncommon. Within this relatively young field, we encourage surgical and materials testing institutions to discuss its standardisation.

Encapsulation state of messenger RNA inside lipid nanoparticles.

Understanding the structure of messenger RNA (mRNA) lipid nanoparticles, and specifically the microenvironment of the mRNA molecules within these entities, is fundamental to advancing their biomedical potential. Here, we show that a permeating cationic dye, thionine, can serve as a cryogenic electron microscopy contrasting agent by binding selectively to encapsulated mRNA without disturbing lipid nanoparticle morphology. Cryo-electron microscopy images identify the mRNA location, revealing that mRNA may exist within solvent-filled cavities or may be substantially lipid associated.

Routine Intra-gastric Balloon Insertion in the Management of 'Super-Super-Obese' Patients: an Obituary?

PURPOSE: To prospectively evaluate the feasibility of single-stage bariatric surgery in patients with super-super obesity and compare their outcomes with patients undergoing intra-gastric balloon insertion as a bridging device prior to definitive surgery. MATERIALS AND METHODS: Data from 42 patients with BMI 60-75 kg/m2 who underwent either intra-gastric balloon insertion followed by sleeve gastrectomy (two-stage group); or attempted bariatric surgery as a single-stage procedure were compared. RESULTS: All patients in the single-stage group underwent successful bariatric surgery. Length of hospital stay after definitive bariatric surgery (3.3 ± 1.9 vs 2.2 ± 0.6 days, p = 0.005) and overall complication rates were significantly higher in the two-stage group. CONCLUSIONS: Routine use of an intra-gastric balloon in super-super obese patients is not required and may be associated with poorer peri-operative outcomes and delayed weight loss.

Risk Factors for Delirium in Older Medical Inpatients in Tanzania.

BACKGROUND: The risk factors for prevalent delirium in older hospitalised adults in Sub-Saharan Africa (SSA) remain poorly characterised. METHODS: A total of 510 consecutive admissions of adults aged ≥60 years to acute medical wards of Kilimanjaro Christian Medical Centre in northern Tanzania were recruited. Patients were assessed within 24 h of admission with a risk factor questionnaire, physiological observations, neurocognitive assessment, and informant interview. Delirium and dementia diagnoses were made according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM V) and DSM IV respectively, by an expert panel. RESULTS: Being male, current alcohol use, dementia, and physiological markers of illness severity were significant independent risk factors for delirium on multivariable analysis. CONCLUSIONS: The risk factors for prevalent delirium in older medical inpatients in SSA include pre-existing dementia, and are similar to those identified in high-income countries. Our data could help inform the development of a delirium risk stratification tool for older adults in SSA.

Increasing the strength and bioactivity of collagen scaffolds using customizable arrays of 3D-printed polymer fibers.

Tendon is a highly aligned connective tissue which transmits force from muscle to bone. Each year, people in the US sustain more than 32 million tendon injuries. To mitigate poor functional outcomes due to scar formation, current surgical techniques rely heavily on autografts. Biomaterial platforms and tissue engineering methods offer an alternative approach to address these injuries. Scaffolds incorporating aligned structural features can promote expansion of adult tenocytes and mesenchymal stem cells capable of tenogenic differentiation. However, appropriate balance between scaffold bioactivity and mechanical strength of these constructs remains challenging. The high porosity required to facilitate cell infiltration, nutrient and oxygen biotransport within three-dimensional constructs typically results in insufficient biomechanical strength. Here we describe the use of three-dimensional printing techniques to create customizable arrays of acrylonitrile butadiene styrene (ABS) fibers that can be incorporated into a collagen scaffold under development for tendon repair. Notably, mechanical performance of scaffold-fiber composites (elastic modulus, peak stress, strain at peak stress, and toughness) can be selectively manipulated by varying fiber-reinforcement geometry without affecting the native bioactivity of the collagen scaffold. Further, we report an approach to functionalize ABS fibers with activity-inducing growth factors via sequential oxygen plasma and carbodiimide crosslinking treatments. Together, we report an adaptable approach to control both mechanical strength and presence of biomolecular cues in a manner orthogonal to the architecture of the collagen scaffold itself. STATEMENT OF SIGNIFICANCE: Tendon injuries account for more than 32 million injuries each year in the US alone. Current techniques use allografts to mitigate poor functional outcomes, but are not ideal platforms to induce functional regeneration following injury. Tissue engineering approaches using biomaterial substrates have significant potential for addressing these defects. However, the high porosity required to facilitate cell infiltration and nutrient transport often dictates that the resultant biomaterials has insufficient biomechanical strength. Here we describe the use of three-dimensional printing techniques to generate customizable fiber arrays from ABS polymer that can be incorporated into a collagen scaffold under development for tendon repair applications. Notably, the mechanical performance of the fiber-scaffold composite can be defined by the fiber array independent of the bioactivity of the collagen scaffold design. Further, the fiber array provides a substrate for growth factor delivery to aid healing.

Tunable, Photoreactive Hydrogel System To Probe Synergies between Mechanical and Biomolecular Cues on Adipose-Derived Mesenchymal Stem Cell Differentiation.

The incorporation of the photoreactive molecule benzophenone into polyacrylamide hydrogels, allowing for orthogonal control over spatial incorporation of biomolecules and selective modulation of matrix stiffness, is described. Adipose-derived mesenchymal stem cells were cultured on matrices whose elastic moduli are tuned to ∼5, ∼14, and ∼37 kPa combined with an immobilized growth factor, bone morphogenic protein 2 (BMP-2), and their lineage differentiation was determined. BMP-2 was observed to have the most pronounced effect at the intermediate stiffness, while the lowest and highest stiffness hydrogels are directed by elasticity alone. Together, this approach describes a facile platform for fundamental studies of cell fate decisions in the context of both mechanical and biochemical cues and may lead to improved insight and effectiveness of stem cell therapies.

Collagen scaffold arrays for combinatorial screening of biophysical and biochemical regulators of cell behavior.

Arrays of 3D macroporous collagen scaffolds with orthogonal gradations of structural and biomolecular cues are described. Gradient maker technology is applied to create linear biomolecular gradients within microstructurally distinct sections of a single CG scaffold array. The array set up is used to explore cell behaviors including proliferation and regulation of stem cell fate.

The combined effects of matrix stiffness and growth factor immobilization on the bioactivity and differentiation capabilities of adipose-derived stem cells.

Biomaterial designs are increasingly incorporating multiple instructive signals to induce a desired cell response. However, many approaches do not allow orthogonal manipulation of immobilized growth factor signals and matrix stiffness. Further, few methods support patterning of biomolecular signals across a biomaterial in a spatially-selective manner. Here, we report a sequential approach employing carbodiimide crosslinking and benzophenone photoimmobilization chemistries to orthogonally modify the stiffness and immobilized growth factor content of a model collagen-GAG (CG) biomaterial. We subsequently examined the singular and combined effects of bone morphogenetic protein (BMP-2), platelet derived growth factor (PDGF-BB), and CG membrane stiffness on the bioactivity and osteogenic/adipogenic lineage-specific gene expression of adipose derived stem cells, an increasingly popular cell source for regenerative medicine studies. We found that the stiffest substrates direct osteogenic lineage commitment of ASCs regardless of the presence or absence of growth factors, while softer substrates require biochemical cues to direct cell fate. We subsequently describe the use of this approach to create overlapping patterns of growth factors across a single substrate. These results highlight the need for versatile approaches to selectively manipulate the biomaterial microenvironment to identify synergies between biochemical and mechanical cues for a range of regenerative medicine applications.

Bromelain decreases neutrophil interactions with P-selectin, but not E-selectin, in vitro by proteolytic cleavage of P-selectin glycoprotein ligand-1.

Stem bromelain, a cysteine protease isolated from pineapples, is a natural anti-inflammatory treatment, yet its mechanism of action remains unclear. Curious as to whether bromelain might affect selectin-mediated leukocyte rolling, we studied the ability of bromelain-treated human neutrophils to tether to substrates presenting immobilized P-selectin or E-selectin under shear stress. Bromelain treatment attenuated P-selectin-mediated tethering but had no effect on neutrophil recruitment on E-selectin substrates. Flow cytometric analysis of human neutrophils, using two antibodies against distinct epitopes within the P-selectin glycoprotein ligand-1 (PSGL-1) active site, revealed that bromelain cleaves PSGL-1 to remove one of two sites required for P-selectin binding, while leaving the region required for E-selectin binding intact. These findings suggest one molecular mechanism by which bromelain may exert its anti-inflammatory effects is via selective cleavage of PSGL-1 to reduce P-selectin-mediated neutrophil recruitment.

Bacteriuria and antibiotic resistance in catheter urine specimens following radical prostatectomy.

OBJECTIVE: There are increasing reports of infectious complications following prostate biopsy due to fluoroquinolone resistance. To determine infectious complications at catheter removal following radical prostatectomy (RP), another setting in daily urological practice where fluoroquinolone prophylaxis is frequently used. MATERIALS AND METHODS: We prospectively examined urine culture results collected from 334 RP patients immediately prior to catheter removal. Patients received prophylactic antibiotics 1 day before, the day of, and for 5 days after catheter removal. Culture results were reviewed for bacterial species and antimicrobial susceptibilities. Patients with positive urine cultures resistant to the prophylactic antibiotic were switched to culture-specific antibiotic therapy and underwent follow-up culture. The frequency of urinary tract infection (UTI), complications, additional antibiotic therapy, and repeat urine cultures was determined within 60 days. RESULTS: Of the 334 patients identified, 203 (61%) had cultures with no bacterial growth, and 48 (14%) had colony counts of <1,000 bacteria or Candida albicans and received no further antibiotics. The remaining 83 (25%) had positive culture results, of which 7% were resistant to ciprofloxacin. Twenty-four bacterial species were identified, with Pseudomonas aeruginosa (5%) Escherichia coli (4%), and Staphylococcus epidermidis (3%) being the most frequent. Only two (0.6%) men developed clinical symptoms consistent with UTI (i.e., suprapubic pain, fever) prior to catheter removal, and no serious complications occurred. CONCLUSIONS: A substantial proportion of RP patients have positive urine cultures at the time of catheter removal, despite the administration of prophylactic fluoroquinolone antibiotics. Potentially virulent organisms are commonly cultured, and ciprofloxacin resistance is frequent. However, outcomes are favorable when culture-specific oral antibiotic therapy is initiated.

Association of prostate cancer risk alleles with unfavourable pathological characteristics in potential candidates for active surveillance.

OBJECTIVE: • To assess whether the carrier status of 35 risk alleles for prostate cancer (CaP) is associated with having unfavourable pathological features in the radical prostatectomy specimen in men with clinically low risk CaP who fulfil commonly accepted criteria as candidates for active surveillance. PATIENTS AND METHODS: • We studied men of European ancestry with CaP who fulfilled the commonly accepted clinical criteria for active surveillance (T1c, prostate-specific antigen <10 ng/mL, biopsy Gleason ≤6, three or fewer positive cores, ≤50% tumour involvement/core) but instead underwent early radical prostatectomy. • We genotyped these men for 35 CaP risk alleles. We defined 'unfavourable' pathological characteristics to be Gleason ≥7 and/or ≥ pT2b in their radical prostatectomy specimen. RESULTS: • In all, 263 men (median age 60 [46-72] years) fulfilled our selection criteria for active surveillance, and 58 of 263 (22.1%) were found to have 'unfavourable' pathological characteristics. • The frequencies of three CaP risk alleles (rs1447295 [8q24], P= 0.004; rs1571801 [9q33.2], P= 0.03; rs11228565 [11q13], P= 0.02) were significantly higher in men with 'unfavourable' pathological characteristics. • Two other risk alleles were proportionately more frequent (rs10934853 [3q21], P= 0.06; rs1859962 [17q24], P= 0.07) but did not achieve nominal statistical significance. • Carriers of any one of the significantly over-represented risk alleles had twice the likelihood of unfavourable tumour features (P= 0.03), and carriers of any two had a sevenfold increased likelihood (P= 0.001). • Receiver-operator curve analysis demonstrated an area under the curve of 0.66, suggesting that the number of single nucleotide polymorphisms carried provided discrimination between men with 'favourable' and 'unfavourable' tumour features in their prostatectomy specimen. CONCLUSION: • In potential candidates for active surveillance, certain CaP risk alleles are more prevalent in patients with 'unfavourable' pathological characteristics in their radical prostatectomy specimen.