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A pharmacist-driven protocol for methicillin-resistant Staphylococcus aureus nares screening and empiric vancomycin discontinuation was instituted in a community healthcare system utilizing a tele-antimicrobial stewardship program to reduce inappropriate use of vancomycin. The protocol and associated intervention resulted in a significant decrease in both vancomycin utilization and the rate of acute kidney injury.
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INTRODUCTION: To analyze healthcare resource utilization (HRU) and healthcare costs in men with metastatic castration-resistant prostate cancer (mCRPC) in the US Medicare population. METHODS: A published claims-based algorithm was used to identify men with mCRPC in the fee-for-service Medicare population between January 1, 2014, and December 31, 2019. Unadjusted all-cause HRU (days) and healthcare costs paid by Medicare (medical and pharmacy) per patient per year (PPPY) are described for the periods before mCRPC diagnosis, after diagnosis, and from the start of first-line (1L), second-line (2L), and third-line (3L) therapy with mCRPC life-prolonging treatments to the start of subsequent therapy or end of follow-up/death. RESULTS: A total of 14,780 men with mCRPC were identified. After mCRPC diagnosis, 11,528 men initiated 1L mCRPC therapy, 6275 initiated 2L, and 2945 initiated 3L. All-cause medical HRU (days PPPY) increased after mCRPC diagnosis and from 1L through 3L treatment, particularly for outpatient care (pre-diagnosis, 10.4; 1L, 16.2; 2L, 18.9; 3L, 22.0) and physician/other visits (pre-diagnosis, 30.1; 1L, 46.5; 2L, 50.2; 3L, 56.9). Similarly, mean all-cause healthcare costs PPPY were $27,468 in the year before mCRPC diagnosis and increased over four fold to $124,379 after mCRPC diagnosis and continued to rise from start of 1L ($148,325) to 2L ($160,118) to 3L ($165,186) therapy. CONCLUSION: HRU and healthcare costs increased substantially following mCRPC diagnosis, and continued to increase even further through progression from 1L through 3L mCRPC therapy. These findings help to quantify the economic burden of mCRPC and to contextualize the economic value of treatments that delay disease progression.
Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Aged , United States , Prostatic Neoplasms, Castration-Resistant/pathology , Retrospective Studies , Medicare , Health Care Costs , Patient Acceptance of Health CareABSTRACT
Triazole antifungals (i.e., fluconazole, itraconazole, voriconazole, posaconazole, and isavuconazole) are commonly used in clinical practice to prevent or treat invasive fungal infections. Most triazole antifungals require therapeutic drug monitoring (TDM) due to highly variable pharmacokinetics, known drug interactions, and established relationships between exposure and response. On behalf of the Society of Infectious Diseases Pharmacists (SIDP), this insight describes the pharmacokinetic principles and pharmacodynamic targets of commonly used triazole antifungals and provides the rationale for utility of TDM within each agent.
Subject(s)
Communicable Diseases , Mycoses , Humans , Antifungal Agents/therapeutic use , Antifungal Agents/pharmacokinetics , Drug Monitoring , Pharmacists , Mycoses/drug therapy , Triazoles/therapeutic use , Voriconazole/therapeutic use , Communicable Diseases/drug therapyABSTRACT
BACKGROUND: Isavuconazole and posaconazole are commonly used for both prophylaxis and treatment of invasive fungal infections. These agents are formulated for oral administration as a capsule and delayed release (DR) tablet or suspension, respectively. In patients unable to swallow, alternative means of administration, such as crushing posaconazole DR tablets and opening isavuconazole capsules, may be used to avoid IV administration or use of posaconazole suspension, which often produces subtherapeutic concentrations. OBJECTIVES: To assess the feasibility of achieving target plasma drug concentrations with enteral feeding tube (EFT) administration of crushed posaconazole DR tablets and opened isavuconazole capsules. METHODS: We retrospectively reviewed pharmacy records to identify patients receiving EFT administration of posaconazole or isavuconazole with concurrent therapeutic drug monitoring from October 2019 to June 2021. Plasma concentrations of either agent as well as clinical outcomes were documented. RESULTS: We identified 37 patients receiving 38 courses of EFT isavuconazole or posaconazole. The majority of patients received primary prophylaxis following lung transplantation (64.9%). Plasma concentrations upon first assessment were therapeutic in the majority of patients (posaconazole 71.5%, isavuconazole 83.3%) with a mean level of 1.61 ± 0.77â mg/L for posaconazole and 2.07 ± 1.1â mg/L for isavuconazole. Of those that were subtherapeutic on initial assessment, all but one subsequently achieved target levels upon dose titration. Standard maintenance doses were used in all isavuconazole and most posaconazole patients. CONCLUSIONS: Our case series demonstrates that isavuconazole and posaconazole can be administered via EFT with concurrent therapeutic drug monitoring to achieve target plasma concentrations in the majority of patients.
Subject(s)
Drug Monitoring , Enteral Nutrition , Administration, Oral , Antifungal Agents/therapeutic use , Capsules , Humans , Nitriles , Pyridines , Retrospective Studies , Suspensions , Tablets , TriazolesABSTRACT
Mounting evidence suggests that pregnant people have an elevated risk of severe COVID-19-related complications compared with their non-pregnant counterparts, underscoring the need for effective prevention and treatment strategies. However, despite progress in innovative and flexible trial designs during the COVID-19 pandemic, regressive policies excluding pregnant and breastfeeding people from biomedical research persist. Remdesivir, a broad-spectrum antiviral, was the first drug licensed for the treatment of COVID-19, based on data showing it reduced the time to recovery in hospitalized patients. Pregnant and breastfeeding people were specifically excluded from all clinical trials of remdesivir in COVID-19, but data are accumulating from post-marketing registries, compassionate use programmes and case series/reports. In this review we synthesize these data and highlight key knowledge gaps to help inform clinical decision-making about its use in pregnancy and lactation.
Subject(s)
COVID-19 Drug Treatment , Pregnancy Complications, Infectious , Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Alanine/therapeutic use , Antiviral Agents/therapeutic use , Breast Feeding , Female , Humans , Lactation , Pandemics , Pregnancy , Pregnancy Complications, Infectious/drug therapy , SARS-CoV-2ABSTRACT
Coccidioidal meningitis (CM) is a life-threatening infection with limited treatment options. Small series have reported success with isavuconazole; however, limited data exist on cerebrospinal fluid (CSF) penetration. Paired plasma and CSF isavuconazole concentrations were measured. Eleven CSF levels were tested, (7 ventricular, 4 lumbar) in three CM patients. Ventricular CSF levels were undetectable despite detectable plasma levels. All lumbar CSF levels were detectable (mean 1.00 µg/ml). Three pairs of lumbar CSF/plasma concentrations taken within 1 h of each other yielded a mean CSF/plasma ratio of 0.31. Isavuconazole was detectable in lumbar but not ventricular CSF in three patients treated for refractory CM. LAY SUMMARY: Isavuconazole is a triazole antifungal that has been used as salvage therapy in the treatment of coccidioidal meningitis (CM). Few data exist characterizing its concentration in the cerebrospinal fluid (CSF). We report tandem plasma and CSF concentrations of isavuconazole in three patients with CM.
Subject(s)
Antifungal Agents/therapeutic use , Cerebrospinal Fluid/drug effects , Coccidioidomycosis/drug therapy , Meningitis, Fungal/drug therapy , Plasma/drug effects , Pyridines/therapeutic use , Triazoles/therapeutic use , Adult , Aged , Antifungal Agents/pharmacokinetics , Drug Monitoring , Female , Humans , Male , Nitriles/blood , Nitriles/cerebrospinal fluid , Nitriles/pharmacokinetics , Nitriles/therapeutic use , Pyridines/blood , Pyridines/cerebrospinal fluid , Treatment Outcome , Triazoles/blood , Triazoles/cerebrospinal fluid , Young AdultABSTRACT
BACKGROUND: Posaconazole-induced pseudohyperaldosteronism (PIPH) has been associated with elevated posaconazole serum concentrations. Clinicians are faced with the difficult task of managing patients with PIPH while maintaining the efficacy of antifungal therapy. Commonly, modifications to posaconazole therapy are utilized in managing PIPH, including dosage reduction of posaconazole or switch to an alternative antifungal. OBJECTIVES: To characterize the management of patients diagnosed with PIPH and their response to various therapeutic interventions. METHODS: We retrospectively reviewed 20 consecutive adult patients diagnosed with PIPH. Patient data collected included blood pressure, electrolytes, endocrine laboratory values and posaconazole serum concentrations collected before and after therapeutic intervention. RESULTS: Of 20 patients included, 17 patients (85%) underwent therapeutic modification, with posaconazole dose reduction (n = 11) as the most common change. Other modifications included discontinuation (n = 3), switch to an alternative antifungal (n = 2) and addition of spironolactone (n = 1). Clinical improvement (decrease in systolic blood pressure and increase in serum potassium) was observed in 9 of 17 patients (52.9%). An average decrease in systolic blood pressure of 7.1 mmHg and increase in serum potassium of 0.22 mmol/L was observed following therapeutic modification. CONCLUSIONS: We report our experience with PIPH management, for which there is no universally effective strategy. We utilized a stepwise approach for management, starting with posaconazole dose reduction and repeat assessment of clinical and laboratory parameters. If resolution of PIPH is not achieved, an alternative triazole antifungal or the addition of an aldosterone antagonist are additional potential interventions. It is possible for PIPH to persist after therapeutic modification despite these interventions. Thus, early diagnosis and continuous monitoring is warranted.
Subject(s)
Antifungal Agents , Triazoles , Adult , Antifungal Agents/adverse effects , Humans , Retrospective Studies , Triazoles/adverse effectsABSTRACT
BACKGROUND: Isavuconazole is a triazole antifungal available in IV and capsule formulation. Prescribing information states that capsules should not be chewed, crushed, dissolved or opened because the drug was not studied in this manner. However, considering the pharmacokinetics of the capsules, we theorized opening and sprinkling the contents into an enteral feeding tube (EFT) would result in adequate absorption and systemic concentrations of isavuconazole. OBJECTIVES: To determine whether patients receiving isavuconazonium sulphate capsules via EFT would achieve clinical blood concentrations of isavuconazole. METHODS: Nineteen solid organ and HCT recipients receiving isavuconazole via EFT for prevention or treatment of invasive fungal infection (IFI) were prospectively identified at four academic medical centres in the USA. Patients were included in this evaluation if they received isavuconazole via EFT for at least 5 days and therapeutic drug monitoring (TDM) was performed. RESULTS: TDM was performed after a median of 7 days (range 6-17) following EFT administration and 15 days (range 7-174) of isavuconazole therapy overall. Median isavuconazole concentration was 1.8 µg/mL (range 0.3-5.2). Median isavuconazole concentrations in patients with or without prior IV administration were 1.8 µg/mL (range 0.3-5.2) and 2.2 µg/mL (range 0.8-3.6; P = 0.896), respectively. Concentrations achieved with the EFT route were similar to or greater than the corresponding concentrations via the IV route in six patients who had TDM performed during both routes of administration. CONCLUSIONS: It is reasonable to consider opening isavuconazonium sulphate capsules and administering the contents enterally for prevention and treatment of IFI.
Subject(s)
Enteral Nutrition , Transplant Recipients , Antifungal Agents/therapeutic use , Capsules , Humans , Nitriles , Pyridines , TriazolesABSTRACT
Remdesivir is a nucleoside antiviral recently studied in several randomized trials for treatment of COVID-19. The available observational and prospective data are conflicting, requiring clinicians to critically evaluate and reconcile results to determine patient populations that may optimally benefit from remdesivir therapy, especially while drug supply is scarce. In this review, we analyze pertinent clinical remdesivir data for patients with COVID-19 from January 1, 2020, through May 31, 2020.
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Biologic therapies including monoclonal antibodies, tyrosine kinase inhibitors, and other agents represent a notable expansion in the pharmacotherapy armamentarium in treatment of a variety of diseases. Many of these therapies possess direct or indirect immunosuppressive and immunomodulatory effects, which have been associated with bacterial, viral, and fungal opportunistic infections. Careful screening of baseline risk factors before initiation, targeted preventive measures, and vigilant monitoring while on active biologic therapy mitigate these risks as use of biologics becomes more commonplace. This review compiles reported evidence of fungal infections associated with these agents with a focus on the tumor necrosis factor-α inhibitor class.
Subject(s)
Biological Products/adverse effects , Mycoses/chemically induced , Adenine/adverse effects , Adenine/analogs & derivatives , Antigens, CD/drug effects , Biological Products/pharmacology , Clinical Trials as Topic , Humans , Mycoses/immunology , Piperidines/adverse effects , Tumor Necrosis Factor-alpha/adverse effects , Tumor Necrosis Factor-alpha/antagonists & inhibitorsABSTRACT
BACKGROUND: Posaconazole tablets are well tolerated and efficacious in the prophylaxis and treatment of aspergillosis, mucormycosis, and other invasive fungal infections. There have been case reports of posaconazole-induced pseudohyperaldosteronism (PIPH); however, its occurrence and association with serum posaconazole drug levels have not previously been investigated. METHODS: In this single-center, retrospective, observational study, we examined the occurrence of PIPH in outpatients newly starting posaconazole and evaluated differences in serum posaconazole concentrations and clinical characteristics between those with and without this syndrome. RESULTS: Sixty-nine patients receiving posaconazole were included, of whom 16 (23.2%) met the definition of PIPH. Patients with PIPH were significantly older (61.1 vs 44.7 years, P = .007) and more frequently had hypertension prior to starting posaconazole (68.8% vs 32.1%, P = .009). Patients with PIPH had a significantly higher median serum posaconazole level than those without PIPH (3.0 vs 1.2 µg/mL, P ≤ .0001). There was a positive correlation between serum posaconazole levels and changes in systolic blood pressure (r = .37, P = .01), a negative correlation between serum posaconazole levels and changes in serum potassium (r = -.39, P = .006), and a positive correlation between serum posaconazole levels and serum 11-deoxycortisol (r = .69, P < .0001). CONCLUSIONS: Posaconazole is associated with secondary hypertension and hypokalemia, consistent with pseudohyperaldosteronism, and development is associated with higher serum posaconazole concentrations, older age, and baseline hypertension.
Subject(s)
Antifungal Agents , Invasive Fungal Infections , Aged , Antifungal Agents/adverse effects , Humans , Invasive Fungal Infections/drug therapy , Retrospective Studies , Triazoles/adverse effectsABSTRACT
BACKGROUND: Fluconazole is a commonly prescribed first-generation triazole antifungal. Although the toxicity profile of fluconazole has been evaluated in clinical trials, there are scant data regarding its tolerability with long-term therapy. Treatment guidelines for coccidioidomycosis recommend fluconazole therapy and severe or disseminated infections can require lifelong treatment. OBJECTIVES: To assess the prevalence of long-term fluconazole adverse effects, their consequences for antifungal therapy, time to adverse effects and the association between dosing regimen or fluconazole serum level and adverse effect status. METHODS: We conducted a single-centre, retrospective study of adult patients (≥18 years) with proven or probable coccidioidomycosis receiving long-term fluconazole therapy for an intended duration of ≥28 days. RESULTS: Out of 124 patients included, 64 (51.6%) experienced adverse effects. The most common adverse effects were xerosis (16.9%), alopecia (16.1%) and fatigue (11.3%). Of the 64 patients experiencing adverse effects, 42 (65.6%) required a therapeutic intervention such as dose reduction, discontinuation or switch to a new antifungal. Patients experiencing adverse effects were prescribed higher total daily fluconazole doses (6.7 versus 5.7 mg/kg; P < 0.01). The median therapeutic drug levels did not differ significantly between patients who experienced adverse effects and those who did not (36.1 versus 28.1 mg/L; P = 0.35). CONCLUSIONS: A significant number of patients receiving long-term fluconazole therapy for coccidioidomycosis experienced adverse effects. Of these, around two-thirds required a therapeutic change. We believe these findings are representative of the adverse effect profile of long-term fluconazole therapy as it is used in clinical practice for coccidioidomycosis as opposed to use in clinical trials.
Subject(s)
Antifungal Agents/adverse effects , Antifungal Agents/therapeutic use , Coccidioidomycosis/drug therapy , Fluconazole/adverse effects , Fluconazole/therapeutic use , Adult , Antifungal Agents/administration & dosage , Coccidioidomycosis/microbiology , Drug-Related Side Effects and Adverse Reactions/diagnosis , Drug-Related Side Effects and Adverse Reactions/etiology , Female , Fluconazole/administration & dosage , Humans , Male , Retrospective Studies , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND: Women with uterine fibroids (UF) may undergo less invasive procedures than hysterectomy, including myomectomy, endometrial ablation (EA), and uterine artery embolization (UAE); however, long-term need for reintervention is not well characterized. We estimated reintervention rates for 5 years and identified predictors of reintervention. MATERIALS AND METHODS: A longitudinal retrospective cohort study was conducted in women in MarketScan® Commercial Claims and Encounters (Truven Health Analytics) aged 18-49 years with UF diagnosis before myomectomy, EA, or UAE from 2008 to 2014. Patients were categorized by initial procedure (index date) and required to have ≥12 months of continuous coverage before and after. Kaplan-Meier analyses and Cox proportional hazard models were used to estimate survival without reintervention and hazard of reintervention for 5 years. RESULTS: The study included 35,631 women with myomectomy (n = 13,804: 8,018 abdominal, 941 hysteroscopic, and 4,845 laparoscopic), EA (n = 17,198), and UAE (n = 4,629). Myomectomy had the lowest 12-month reintervention rate (4.2%), followed by UAE (7.0%), then EA (12.4%; both p < 0.001 relative of myomectomy). Estimates of 5-year reintervention rates were 19% for myomectomy (17%, 28%, and 20% for abdominal, hysteroscopic, and laparoscopic, respectively), 33% for EA, and 24% for UAE. EA and UAE had adjusted hazard ratios of 2.63 (95% confidence interval [CI], 2.44-2.83) and 1.56 (95% CI, 1.42-1.72). Prior anemia, bleeding, pelvic inflammatory disease, and abdominal and pelvic pain increased the hazard of reintervention. CONCLUSION: Reintervention rate estimates ranged from 17% to 33% for 5 years after myomectomy, EA, and UAE for patients with UF. Risk of requiring reintervention should be considered during treatment selection.
Subject(s)
Endometrial Ablation Techniques/adverse effects , Leiomyoma/surgery , Postoperative Complications , Reoperation/statistics & numerical data , Uterine Artery Embolization/adverse effects , Uterine Myomectomy/adverse effects , Uterine Neoplasms/surgery , Adult , Endometrial Ablation Techniques/methods , Endometrial Ablation Techniques/statistics & numerical data , Female , Humans , Leiomyoma/epidemiology , Leiomyoma/pathology , Middle Aged , Outcome and Process Assessment, Health Care , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/surgery , United States/epidemiology , Uterine Artery Embolization/methods , Uterine Artery Embolization/statistics & numerical data , Uterine Myomectomy/methods , Uterine Myomectomy/statistics & numerical data , Uterine Neoplasms/epidemiology , Uterine Neoplasms/pathologyABSTRACT
Purpose: The purpose of this study was to quantify the biomechanical response of human posterior ocular tissues from donors of various racioethnic groups to better understand how differences in these properties may play a role in the racioethnic health disparities known to exist in glaucoma. Methods: Sequential digital image correlation (S-DIC) was used to measure the pressure-induced surface deformations of 23 normal human posterior poles from three racioethnic groups: African descent (AD), European descent (ED), and Hispanic ethnicity (HIS). Regional in-plane principal strains were compared across three zones: the optic nerve stump (ONS), the peripapillary (PP) sclera, and non-PP sclera. Results: The PP scleral tensile strains were found to be lower for ED eyes compared with AD and HIS eyes at 15 mm Hg (P = 0.024 and 0.039, respectively). The mean compressive strains were significantly higher for AD eyes compared with ED eyes at 15 mm Hg (P = 0.018). We also found that the relationship between tensile strain and pressure was significant for those of ED and HIS eyes (P < 0.001 and P = 0.004, respectively), whereas it was not significant for those of AD (P = 0.392). Conclusions: Our results suggest that, assuming glaucomatous nerve loss is caused by mechanical strains in the vicinity of the optic nerve head, the mechanism of increased glaucoma prevalence may be different in those of AD versus HIS. Our ONS strain analysis also suggested that it may be important to account for ONS geometry and material properties in future scleral biomechanical analysis.
Subject(s)
Axons/pathology , Black People , Glaucoma/ethnology , Hispanic or Latino , Optic Disk/pathology , Optic Nerve Diseases/ethnology , White People , Aged , Aged, 80 and over , Female , Glaucoma/physiopathology , Humans , Intraocular Pressure/physiology , Male , Middle Aged , Optic Nerve Diseases/physiopathology , Sclera , Tissue DonorsABSTRACT
To investigate the effects of two different dosages of sildenafil on patients with erectile dysfunction (ED), a total of 3,674 patients with ED were recruited to answer questionnaires designed specifically for this study. There were 977 patients in the 50 mg group and there were 2,697 patients in the 100 mg group. Both 50 mg and 100 mg of sildenafil therapy increased the ED patients' average monthly frequency of sexual intercourse, improved erectile function state in self-assessment, and elevated sexual satisfaction and enjoyment. Despite a higher rate of concomitant diseases, patients in the higher dosage of sildenafil group had a better outcome in the average monthly frequency of sexual intercourse and sexual enjoyment compared with those in the lower dosage. Such a study might be helpful for health care providers to choose sildenafil dosage for patients with ED.
Subject(s)
Dose-Response Relationship, Drug , Erectile Dysfunction/drug therapy , Sildenafil Citrate/administration & dosage , Vasodilator Agents/administration & dosage , Adult , Age Distribution , Humans , Male , Middle Aged , Surveys and QuestionnairesABSTRACT
BACKGROUND: Interleukin-32 (IL-32) is a recently recognized intracellular, proinflammatory cytokine which may play a role in cancer metastasis and patient survival. The role of IL-32 in cancer, especially its direct effect on cancer cells, is not well understood. MATERIAL AND METHODS: Clonogenic assay, PCNA staining, Quick Cell Proliferation assay, TUNEL staining, and caspase-3 activity assay were used to investigate the in vitro role for IL-32α in human melanoma growth. We further investigated the possible molecular mechanisms using RT-PCR and immunohistochemical staining. RESULTS: Exogenous administration of IL-32α inhibited proliferation of the HTB-72 human melanoma cell line, but had little effect on other melanoma cell lines. Inhibition of proliferation in HTB-72 correlated with increased expression of p21 and p53. IL-32α administration also increased apoptosis in HTB-72. This finding correlated with increased expression of TRAILR1. CONCLUSIONS: The data presented suggest a direct effect of IL-32α on the growth of human melanoma and give some insight into the mechanisms which may in part govern this effect. J. Surg. Oncol. 2016;113:364-369. © 2016 Wiley Periodicals, Inc.
Subject(s)
Interleukins/pharmacology , Melanoma/drug therapy , Apoptosis/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p21/biosynthesis , Humans , Immunohistochemistry , Melanoma/metabolism , Melanoma/pathology , Receptors, TNF-Related Apoptosis-Inducing Ligand/biosynthesis , Tumor Suppressor Protein p53/biosynthesisABSTRACT
Davis, MR, Easter, RL, Carlock, JM, Weiss, LW, Longo, EA, Smith, LM, Dawes, JJ, and Schilling, BK. Self-reported physical tasks and exercise training in Special Weapons and Tactics (SWAT) teams. J Strength Cond Res 30(11): 3242-3248, 2016-Little research has been done examining the most physically demanding tasks a SWAT officer may perform in the line of duty. Our objective was to analyze the rankings of tasks by SWAT officers based on frequency, difficulty, and importance and assess if training is addressing traits needed for successful task completion. A survey was designed using Qualtrics (Qualtrics Labs Inc). The survey had a demographics section, performance section, and training section. Officers were contacted by phone or e-mail and asked about interest in participating. Officers who agreed were sent the survey. Our results found a strong correlation between frequency of task and importance (r = 0.69, p = 0.001), and a moderate correlation was found between task difficulty and importance (r = 0.37, p = 0.005). Task rankings were averaged across the 3 domains to assess "overall" importance, and the top 3 tasks were assessed for necessary traits for successful performance. Power and strength were determined to be the most important traits for successful performance. Officers ranked the top 2 focuses of their training program in the training section as stamina/muscular endurance and cardiovascular/respiratory endurance. Training programs for SWAT officers should be developed to improve performance of the tasks with the highest "overall" importance. Therefore, a training program should emphasize strength and power improvements while not neglecting other measures of fitness.
Subject(s)
Military Personnel , Needs Assessment , Physical Conditioning, Human , Adult , Humans , Muscle Strength , Physical Endurance , Self Report , United StatesABSTRACT
Cation-π interactions are common in biological systems, and many structural studies have revealed the aromatic box as a common motif. With the aim of understanding the nature of the aromatic box, several computational methods were evaluated for their ability to reproduce experimental cation-π binding energies. We find the DFT method M06 with the 6-31G(d,p) basis set performs best of several methods tested. The binding of benzene to a number of different cations (sodium, potassium, ammonium, tetramethylammonium, and guanidinium) was studied. In addition, the binding of the organic cations NH4(+) and NMe4(+) to ab initio generated aromatic boxes as well as examples of aromatic boxes from protein crystal structures were investigated. These data, along with a study of the distance dependence of the cation-π interaction, indicate that multiple aromatic residues can meaningfully contribute to cation binding, even with displacements of more than an angstrom from the optimal cation-π interaction. Progressive fluorination of benzene and indole was studied as well, and binding energies obtained were used to reaffirm the validity of the "fluorination strategy" to study cation-π interactions in vivo.