Caring for Diverse and High-Risk Patients: Surgeon, Health System, and Patient Integration.

Access and outcome disparities exist in hip and knee arthroplasty care. These disparities are associated with race, ethnicity, and social determinants of health such as income, housing, transportation, education, language, and health literacy. Additionally, medical comorbidities affecting postoperative outcomes are more prevalent in underresourced communities, which are more commonly communities of color. Navigating racial and ethnic differences in treating our patients undergoing hip and knee arthroplasty is necessary to reduce inequitable care. It is important to recognize our implicit biases and lessen their influence on our healthcare decision-making. Social determinants of health need to be addressed on a large scale as the current inequitable system disproportionally impacts communities of color. Patients with lower health literacy have a higher risk of postoperative complications and poor outcomes after hip and knee replacement. Low health literacy can be addressed by improving communication, reducing barriers to care, and supporting patients in their efforts to improve their own health. High-risk patients require more financial, physical, and mental resources to care for them, and hospitals, surgeons, and health insurance companies are often disincentivized to do so. By advocating for alternative payment models that adjust for the increased risk and take into account the increased perioperative work needed to care for these patients, surgeons can help reduce inequities in access to care. We have a responsibility to our patients to recognize and address social determinants of health, improve the diversity of our workforce, and advocate for improved access to care to decrease inequity and outcomes disparities in our field.

Use of tranexamic acid results in decreased blood loss and decreased transfusions in patients undergoing staged bilateral total knee arthroplasty.

BACKGROUND: Tranexamic acid (TXA) is an antifibrinolytic that reduces blood loss and transfusion rates in total joint arthroplasty. Blood loss and allogenic transfusion rates have not been well studied in patients receiving TXA and undergoing bilateral staged total knee arthroplasty (TKA). The purpose was to evaluate the effect of TXA on blood loss, hemoglobin (Hb) changes, and transfusion in patients undergoing staged bilateral TKA. STUDY DESIGN AND METHODS: The authors compared 51 patients undergoing staged bilateral TKA who received TXA (2 g; subjects) with 70 who did not (controls). There were no significant differences between the groups in terms of demographics or preoperative Hb. For each TKA, 1 g of TXA was administered intravenously 15 minutes before incision and 1 g was administered intravenously at tourniquet release. Blood loss, Hb levels, and transfusions were recorded. Statistical analyses were performed using computer software. Significance was set at 0.05. RESULTS: Subjects had a significantly lower (p < 0.001) mean (±SD) blood loss (373.8 ± 264.6 mL vs. 871.6 ± 457.7 mL), significantly higher (p < 0.005) Hb levels on Postoperative Days 1 and 2, and a significantly lower (p < 0.001) mean (±SD) number of transfused allogenic blood units (0.60 ± 0.84 units vs. 1.53 ± 1.30 units). CONCLUSIONS: TXA reduces blood loss, improves postoperative Hb, and decreases the allogenic blood transfusion requirements for patients undergoing bilateral staged TKA. TXA is an option for patients choosing bilateral staged TKA to decrease the risks associated with blood transfusion or when autologous blood is not available.

All-polyethylene tibial components in obese patients are associated with low failure at midterm followup.

BACKGROUND: In the United States, the obese population has increased markedly over the last four decades, and this trend continues. High patient weight places additional stress on TKA components, which may lead to increased polyethylene wear, osteolysis, radiolucencies, and clinical failure. Metal-backed tibial components and all-polyethylene tibial components in the general population have comparable osteolysis and failure, but it is unclear whether these components yield similar osteolysis and failure in obese patients. QUESTIONS/PURPOSES: We therefore determined the (1) function, (2) occurrence of osteolysis, and (3) complications in a cohort of obese patients receiving all-polyethylene tibial components. PATIENTS AND METHODS: Between September 17, 1996, and December 19, 2002, we implanted all-polyethylene tibial components in 90 obese patients (125 knees); 24 patients (33 knees) died and 13 patients (17 knees) were lost to followup, leaving 53 patients (59%) with 75 knees. All surgeries were cruciate-retaining, tricompartmental TKAs. We evaluated patients with Knee Society Scores and serial radiographs. Minimum followup was 7 years (mean, 10.4 years; range, 7-14 years). RESULTS: At latest followup, mean Knee Society Score was 92 points. There were five tibial radiolucencies, all less than 1 mm and characterized as nonprogressive. We observed minimal, nonprogressive osteolysis in one knee. One patient required reoperation after a traumatic event. There were no implant-related failures and no implants at risk of failure. CONCLUSIONS: At an average 10-year followup, all-polyethylene tibial components were functioning well in this obese group. These findings confirm the effectiveness of all-polyethylene tibial components in obese patients.

Diversity of virus-host systems in hypersaline Lake Retba, Senegal.

Remarkable morphological diversity of virus-like particles was observed by transmission electron microscopy in a hypersaline water sample from Lake Retba, Senegal. The majority of particles morphologically resembled hyperthermophilic archaeal DNA viruses isolated from extreme geothermal environments. Some hypersaline viral morphotypes have not been previously observed in nature, and less than 1% of observed particles had a head-and-tail morphology, which is typical for bacterial DNA viruses. Culture-independent analysis of the microbial diversity in the sample suggested the dominance of extremely halophilic archaea. Few of the 16S sequences corresponded to known archeal genera (Haloquadratum, Halorubrum and Natronomonas), whereas the majority represented novel archaeal clades. Three sequences corresponded to a new basal lineage of the haloarchaea. Bacteria belonged to four major phyla, consistent with the known diversity in saline environments. Metagenomic sequencing of DNA from the purified virus-like particles revealed very few similarities to the NCBI non-redundant database at either the nucleotide or amino acid level. Some of the identifiable virus sequences were most similar to previously described haloarchaeal viruses, but no sequence similarities were found to archaeal viruses from extreme geothermal environments. A large proportion of the sequences had similarity to previously sequenced viral metagenomes from solar salterns.

Evidence of two genetic clusters of manatees with low genetic diversity in Mexico and implications for their conservation.

The Antillean manatee (Trichechus manatus manatus) occupies the tropical coastal waters of the Greater Antilles and Caribbean, extending from Mexico along Central and South America to Brazil. Historically, manatees were abundant in Mexico, but hunting during the pre-Columbian period, the Spanish colonization and throughout the history of Mexico, has resulted in the significantly reduced population occupying Mexico today. The genetic structure, using microsatellites, shows the presence of two populations in Mexico: the Gulf of Mexico (GMx) and Chetumal Bay (ChB) on the Caribbean coast, with a zone of admixture in between. Both populations show low genetic diversity (GMx: N(A) = 2.69; H(E) = 0.41 and ChB: N(A) = 3.0; H(E) = 0.46). The lower genetic diversity found in the GMx, the largest manatee population in Mexico, is probably due to a combination of a founder effect, as this is the northern range of the sub-species of T. m. manatus, and a bottleneck event. The greater genetic diversity observed along the Caribbean coast, which also has the smallest estimated number of individuals, is possibly due to manatees that come from the GMx and Belize. There is evidence to support limited or unidirectional gene flow between these two important areas. The analyses presented here also suggest minimal evidence of a handful of individual migrants possibly between Florida and Mexico. To address management issues we suggest considering two distinct genetic populations in Mexico, one along the Caribbean coast and one in the riverine systems connected to the GMx.

Seven-coordinate anion complex with a tren-based urea: binding discrepancy of hydrogen sulfate in solid and solution states.

Structural characterization of a hydrogen sulfate complex with a tren-based urea suggests that the anion is coordinated with six NH···O bonds (d(N···O) = 2.857 (3) to 3.092 (3) Å) and one OH···O bond (d(O···O) = 2.57 (2) Å) from three receptors; however, in solution the anion is bound within the pseudo-cavity of one receptor.

When can I drive?: brake response times after contemporary total knee arthroplasty.

BACKGROUND: After right total knee arthroplasty (TKA), patients are usually eager to return to driving. Previous studies suggest 6 weeks postsurgery is a safe time. However, recent advances in surgical technique, pain management, and rehabilitation have theoretically improved recovery after TKA. QUESTIONS/PURPOSES: We therefore determined if (1) the timeframe for return to driving, as determined by attainment of preoperative braking levels, would be shorter after contemporary right TKA than that reported previously for a traditional TKA; and (2) gender or age influence recovery of baseline response time. METHODS: Brake response times for all 29 patients undergoing right-sided TKA between January 17, 2008, and January 29, 2009, were scheduled to be measured by a trained occupational therapist before surgery and at 4, 6, and 8 weeks after surgery. For each patient, testing was discontinued once the preoperative level was achieved. RESULTS: All patients returned to baseline braking levels by 4 weeks after surgery. Gender and age did not influence recovery times. CONCLUSIONS: If other requirements for driving are met, surgeons may consider allowing patients treated with contemporary right TKAs to drive 4 weeks after surgery.

A Creative Model for an Interdisciplinary Approach to Service-Learning.

The biological sciences are inherently interdisciplinary and important advances in biology cannot be made without collaboration. Despite the increasing emphasis on interdisciplinarity in higher education, science courses only rarely extend to content outside of the STEM discipline. Classes are typically taught by one faculty member in one discipline. To demonstrate relevance while addressing genuine community needs, faculty can use service-learning in their courses. Service-learning is an experiential learning strategy where students learn course content and additional relevant skills through completing service with a community partner. Community needs are frequently beyond the scope of a single course or discipline. In order to better meet community needs, an interdisciplinary collaboration provides a more comprehensive experience that highlights the application and interconnection of course content. This article presents a generalisable model for successful interdisciplinary collaborations. While the nature of course scheduling, academic department structure, and faculty workload can be barriers to collaboration between faculty, they are not insurmountable and accomplishable within this framework. The benefits to the students and the community far outweigh navigating these challenges. Using an interdisciplinary approach in teaching will not only enrich course content and expand student learning in multiple areas, but also increase collaboration within the academy while better meeting community needs.

Biology Beyond the Classroom: Experiential Learning Through Authentic Research, Design, and Community Engagement.

This paper introduces the collection of manuscripts from the symposium, "Biology Beyond the Classroom: Experiential Learning through Authentic Research, Design, and Community Engagement," presented at the 2021 annual meeting of the Society for Integrative and Comparative Biology. The following papers showcase innovative approaches for engaging undergraduate students in experiential science learning experiences. Specifically, we focus on three high-impact practices that allow students to take their learning outside of the classroom for increased relevance and authenticity: (1) Course-Based Undergraduate Research, (2) Digital Fabrication in Makerspaces, and (3) Service or Community-based Learning Opportunities. Although each topic is unique, all provide an alternative approach to the traditional lecture and have proven effective at appealing to diverse groups of students who are traditionally underrepresented in the Science, Technology, Engineering, and Mathematics workforce.

A Multicenter, double-blind trial of a high-dose caspofungin treatment regimen versus a standard caspofungin treatment regimen for adult patients with invasive candidiasis.

BACKGROUND: The standard caspofungin treatment regimen (50 mg/day after a 70-mg dose on day 1) is effective and well tolerated for the treatment of invasive candidiasis, but experience with higher doses of caspofungin is limited. We evaluated the safety and efficacy of caspofungin at 3 times the standard dosing regimen. METHODS: Patients with proven invasive candidiasis were randomized to receive a standard or high-dose (150 mg/day) caspofungin treatment regimen. Safety was assessed in all patients as treated. Efficacy was assessed as a secondary objective in a full-analysis-set population. A favorable overall response was defined as symptom resolution and microbiological clearance at the end of caspofungin therapy. RESULTS: A total of 204 patients were included in the safety analysis (104 received the standard regimen, and 100 received the high-dose regimen), and 197 were included in the efficacy analysis (102 and 95 in the standard and high-dose treatment groups, respectively). Patient demographic characteristics, neutropenia status (6.7% and 8.0% had neutropenia, respectively), and Acute Physiology and Chronic Health Evaluation II scores (mean, 16.5 and 17, respectively) were similar between treatment groups. Significant drug-related adverse events occurred in 1.9% of patients receiving the standard regimen and 3.0% of patients receiving the high-dose regimen (difference, 1.1%; 95% confidence interval, -4.1% to 6.8%). The most-common drug-related adverse events in the standard and high-dose treatment groups were phlebitis (3.8% and 2.0%, respectively), increased alkaline phosphatase level (6.9% and 2.0%, respectively), and increased aspartate transaminase level (4.0% and 2.0%, respectively). Overall, 71.6% of patients who received the standard regimen and 77.9% of patients who received the high-dose regimen had favorable overall responses (difference, 6.3%; 95% confidence interval, -5.9% to 18.4%; not statistically significant). Mortality at 8 weeks after therapy was similar between groups. CONCLUSIONS: Both caspofungin dosing regimens were effective and well tolerated in patients with invasive candidiasis. No safety concerns were found for caspofungin at a dosage of 150 mg/day.

Results of 20 consecutive patients treated with the Repiphysis expandable prosthesis for primary malignant bone.

Limb-salvage for primary malignant bone tumors in pediatric patients presents a unique challenge when resection includes an active physis. Early expandable prostheses required open surgical procedures to achieve lengthening. Newer prostheses are capable of achieving expansion without open procedures through the use of an electromagnetic field. This study reports our results with 90 consecutive expansion procedures using the Repiphysis(®) prosthesis. We retrospectively reviewed the records of 20 patients (22 limbs) who underwent limb-salvage using the Repiphysis(®) prosthesis from 2003 to 2015. There were 9 males and 11 females with a mean age of 9 years and 9 months (6-16 years). Reconstruction included the distal femur in 11 cases, total femur in four, proximal tibia in three, proximal humerus in three, and total humerus in one. Complications were reviewed and functional scores were recorded using the MSTS/ISOLS system. Five patients had a second prosthesis implanted during the course of the study for a total of 27 prostheses. The mean follow-up was 57 (6-148) months. Four patients have not been expanded: three due to death prior to lengthening, and one patient who has not yet developed a leg length discrepancy. Ninety consecutive expansion procedures were performed in 18 limbs in 16 patients. A mean of 9 (5-20) mm was gained per expansion and 4.8 cm per patient who has undergone expansion to date. Seven patients have reached skeletal maturity and have been converted to an adult endoprosthesis. These patients averaged 8 expansions per patient and a mean of 7.4 (1.8-12.9) cm in length gained. There were 15 complications in 11 patients including one dislocation, one contracture, four cases of aseptic loosening, five structural failures (three expansion mechanism failures and two tibial fractures), three deep infections, and one case of local recurrence. The mean MSTS score was 80 % (37-97 %) and the limb retention rate was 95 %. The results of this study are comparable to previous studies involving non-invasive prostheses. This study hopefully provides additional data for clinicians to consider when faced with limb threatening sarcomas in the immature skeleton.

Diversity of environmental single-stranded DNA phages revealed by PCR amplification of the partial major capsid protein.

The small single-stranded DNA (ssDNA) bacteriophages of the subfamily Gokushovirinae were traditionally perceived as narrowly targeted, niche-specific viruses infecting obligate parasitic bacteria, such as Chlamydia. The advent of metagenomics revealed gokushoviruses to be widespread in global environmental samples. This study expands knowledge of gokushovirus diversity in the environment by developing a degenerate PCR assay to amplify a portion of the major capsid protein (MCP) gene of gokushoviruses. Over 500 amplicons were sequenced from 10 environmental samples (sediments, sewage, seawater and freshwater), revealing the ubiquity and high diversity of this understudied phage group. Residue-level conservation data generated from multiple alignments was combined with a predicted 3D structure, revealing a tendency for structurally internal residues to be more highly conserved than surface-presenting protein-protein or viral-host interaction domains. Aggregating this data set into a phylogenetic framework, many gokushovirus MCP clades contained samples from multiple environments, although distinct clades dominated the different samples. Antarctic sediment samples contained the most diverse gokushovirus communities, whereas freshwater springs from Florida were the least diverse. Whether the observed diversity is being driven by environmental factors or host-binding interactions remains an open question. The high environmental diversity of this previously overlooked ssDNA viral group necessitates further research elucidating their natural hosts and exploring their ecological roles.

Diversity and distribution of single-stranded DNA phages in the North Atlantic Ocean.

Knowledge of marine phages is highly biased toward double-stranded DNA (dsDNA) phages; however, recent metagenomic surveys have also identified single-stranded DNA (ssDNA) phages in the oceans. Here, we describe two complete ssDNA phage genomes that were reconstructed from a viral metagenome from 80 m depth at the Bermuda Atlantic Time-series Study (BATS) site in the northwestern Sargasso Sea and examine their spatial and temporal distributions. Both genomes (SARssφ1 and SARssφ2) exhibited similarity to known phages of the Microviridae family in terms of size, GC content, genome organization and protein sequence. PCR amplification of the replication initiation protein (Rep) gene revealed narrow and distinct depth distributions for the newly described ssDNA phages within the upper 200 m of the water column at the BATS site. Comparison of Rep gene sequences obtained from the BATS site over time revealed changes in the diversity of ssDNA phages over monthly time scales, although some nearly identical sequences were recovered from samples collected 4 years apart. Examination of ssDNA phage diversity along transects through the North Atlantic Ocean revealed a positive correlation between genetic distance and geographic distance between sampling sites. Together, the data suggest fundamental differences between the distribution of these ssDNA phages and the distribution of known marine dsDNA phages, possibly because of differences in host range, host distribution, virion stability, or viral evolution mechanisms and rates. Future work needs to elucidate the host ranges for oceanic ssDNA phages and determine their ecological roles in the marine ecosystem.

Characterization of highly informative cross-species microsatellite panels for the Australian dugong (Dugong dugon) and Florida manatee (Trichechus manatus latirostris) including five novel primers.

The Australian dugong (Dugong dugon) and Florida manatee (Trichechus manatus latirostris) are threatened species of aquatic mammals in the order Sirenia. Sirenian conservation and management actions would benefit from a more complete understanding of genetic diversity and population structure. Generally, species-specific microsatellite markers are employed in conservation genetic studies; however, robust markers can be difficult and costly to isolate. To increase the number of available markers, dugong and manatee microsatellite primers were evaluated for cross-species amplification. Furthermore, one manatee and four dugong novel primers are reported. After polymerase chain reaction optimization, 23 (92%) manatee primers successfully amplified dugong DNA, of which 11 (48%) were polymorphic. Of the 32 dugong primers tested, 27 (84%) yielded product in the manatee, of which 17 (63%) were polymorphic. Dugong and manatee primers were compared and the most informative markers were selected to create robust and informative marker-panels for each species. These cross-species microsatellite marker-panels can be employed to assess other sirenian populations and can provide beneficial information for the protection and management of these unique mammals.