Treatment with convalescent plasma in solid organ transplant recipients with COVID-19: Experience at large transplant center in New York City

Solid organ transplant (SOT) recipients may be at higher risk for poor outcomes with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Convalescent plasma is an investigational therapy that may benefit immunosuppressed patients by providing passive immunity. Convalescent plasma was administered to hospitalized patients with coronavirus disease-2019 (COVID-19) at an academic transplant center in New York City. Eligible patients were hospitalized and required to have positive nasopharyngeal polymerase chain reaction (PCR) diagnosis of SARS-CoV-2 infection, be at least 18 years old, and have either dyspnea, blood oxygen saturation ≤ 93% on ambient air, respiratory frequency ≥ 30 breaths/min, partial pressure of arterial oxygen to fraction of inspired oxygen ratio < 300, or lung infiltrates > 50%. Thirteen SOT recipients received convalescent plasma from April 9, 2020, to May 17, 2020. The median time from symptom onset to plasma infusion was 8 days. Eight of 13 patients (62%) had de-escalating oxygenation support by day 7 post-convalescent plasma. Nine (69%) patients were discharged, 1 (7%) patients remain hospitalized, and 3 (23%) patients died. This series supports the need for additional studies on convalescent plasma use in SOT recipients with COVID-19 to better determine efficacy and identify patients who are likely to benefit.     

Mersacidin eradicates methicillin-resistant Staphylococcus aureus (MRSA) in a mouse rhinitis model

OBJECTIVES: Methicillin-resistant Staphylococcus aureus (MRSA) often colonize the anterior nares, and nasal carriage remains the main source of bacterial dissemination. The aim of this study was to assess the in vivo activity of the lantibiotic mersacidin against MRSA colonizing nasal epithelia. METHODS: The efficiency of mersacidin in the eradication of MRSA was tested employing mice pre-treated with hydrocortisone and inoculated intranasally either three or six times with a bacterial suspension. RESULTS: In mersacidin-treated animals, pre-colonized with MRSA, bacteria could not be detected in blood, lungs, liver, kidney, spleen or nasal scrapings and there were no lesions manifested after intraperitoneal drug application. Blood samples from infected mice obtained 2 h after mersacidin therapy revealed anti-MRSA activity in a serum bactericidal test. Moreover, elevated interleukin-1beta and tumour necrosis factor-alpha titres were noticed in the pre-infected but not in cured animals. In contrast, mersacidin did not induce differences in the cytokine profiles of treated uninfected control mice. CONCLUSIONS: In the mouse rhinitis model, mersacidin was able to eradicate MRSA colonization. The site of action (epithelium versus blood) of mersacidin needs to be further explored.     

Optical mechanisms regulating emmetropisation and refractive errors: evidence from animal models

Our current understanding of emmetropisation and myopia development has evolved from decades of work in various animal models, including chicks, non-human primates, tree shrews, guinea pigs, and mice. Extensive research on optical, biochemical, and environmental mechanisms contributing to refractive error development in animal models has provided insights into eye growth in humans. Importantly, animal models have taught us that eye growth is locally controlled within the eye, and can be influenced by the visual environment. This review will focus on information gained from animal studies regarding the role of optical mechanisms in guiding eye growth, and how these investigations have inspired studies in humans. We will first discuss how researchers came to understand that emmetropisation is guided by visual feedback, and how this can be manipulated by form-deprivation and lens-induced defocus to induce refractive errors in animal models. We will then discuss various aspects of accommodation that have been implicated in refractive error development, including accommodative microfluctuations and accommodative lag. Next, the impact of higher order aberrations and peripheral defocus will be discussed. Lastly, recent evidence suggesting that the spectral and temporal properties of light influence eye growth, and how this might be leveraged to treat myopia in children, will be presented. Taken together, these findings from animal models have significantly advanced our knowledge about the optical mechanisms contributing to eye growth in humans, and will continue to contribute to the development of novel and effective treatment options for slowing myopia progression in children.     

Analysis of failure and clinical outcome after unsuccessful medial patellofemoral ligament reconstruction in young patients

Purpose

Reconstruction of the medial patellofemoral ligament (MPFL) has become a popular procedure for patients with patellofemoral instability. Nevertheless, complication rates of up to 26 % have been reported. This study presents the analysis of failure and clinical outcome of subsequent revision surgery in young patients following unsuccessful medial patellofemoral ligament reconstruction.

Methods

Nineteen consecutive patients with unsuccessful MPFL reconstruction underwent revision surgery. Pre-operative assessment included physical examination, radiographs and magnetic resonance imaging to assess the MPFL graft, trochlear dysplasia, tibial tubercle–trochlear groove (TT-TG) distance, patella alta and femoral tunnel positioning. Evaluation also included the detection of cartilage injuries as well as visual analog scale (VAS), knee function scores and patient satisfaction. Each complication was analysed and an appropriate revision procedure was performed according to the identified technical or untreated anatomical risk factor.

Results

The average age at the time of the index operation was 20.2 years (range, 16–27 years). The average age at the time of the primary MPFL reconstruction was 18.4 years (range, 15–25). Three main reasons for failure after MPFL reconstruction could be identified: failure to consider additional risk factors, intra-operative technical errors and inappropriate patient selection. In five patients severe trochlear dysplasia and in two patients concomitant excessive femoral anteversion as additional risk factors were detected. Seven patients experienced medial retinacular pain with limited flexion due to technical errors caused in three patients by anterior placement of the femoral tunnel and in four others by overtensioning of the MPFL graft. Four patients with patellofemoral pain were found to have ICRS grade III or IV cartilage injuries. The median postoperative Kujala scores improved from 57 (34 – 73) pre-operatively to 83 (49 – 94), the median knee function improved from 5 (range, 2 – 6) pre-operatively to 8 (range, 3 – 10). Median VAS scores improved from 4 (2 – 7) to 2 (0 – 5). A total of 78.9 % of patients were satisfied or very satisfied, 15.8 % were partially satisfied and one patient (5.3 %) was not satisfied with the result after revision surgery.

Conclusion

Failure to consider additional risk factors, technical intra-operative errors and inappropriate patient selection were identified as reasons for revision surgery after MPFL reconstruction. Identifying the potential causes of failure can help to treat and possibly prevent future complications.