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Background: The presence of thigh muscle edema as characterized by increased signal intensity on MRI has been used to support the diagnosis of presumed local anesthetic-induced myotoxicity reported after total knee arthroplasty (TKA) with continuous adductor canal block (CACB). However, neither postoperative baseline imaging appearance nor muscle enzyme values have been described in conjunction with this clinical scenario. Thus, the usefulness of MRI or enzymatic biomarkers of muscle injury for supporting the diagnosis of local anesthetic myotoxicity is unknown., Methods: This descriptive case series documents postoperative MRI appearance of the ipsilateral upper leg, plus preoperative and postoperative creatine phosphokinase and aldolase values in volunteer patients who underwent uncomplicated TKA with CACB., Results: In 27 volunteer patients with no postsurgical evidence of clinically relevant myotoxicity, anterior thigh muscle edema was universally evident on imaging (n=12) and muscle enzyme values (n=19) were normal or only slightly elevated., Conclusions: The non-specificity of these findings suggests that MRI and near normal muscle enzyme levels are of limited diagnostic value when there is clinical suspicion of local anesthetic myotoxicity in the setting of TKA with CACB., Trial Registration Number: NCT04821245., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Articular cartilage injury and degeneration is a frequent occurrence in synovial joints. Treatment of these articular cartilage lesions are a challenge because this tissue is incapable of quality repair and/or regeneration to its native state. Nonoperative treatments endeavor to control symptoms, and include anti-inflammatory medication, viscosupplementation, bracing, orthotics, and activity modification. Techniques to stimulate the intrinsic repair (fibrocartilage) process include drilling, abrasion, and microfracture of the subchondral bone. Currently, the clinical biologic approaches to treat cartilage defects include autologous chondrocyte implantation, periosteal transfer, and osteochondral autograft or allograft transplantation. Newer strategies employing tissue engineering being studied involve the use of combinations of progenitor cells, bioactive factors, and matrices, and the use of focal synthetic devices. Many new and innovative treatments are being explored in this exciting field. However, there is a paucity of prospective, randomized controlled clinical trials that have compared the various techniques, treatment options, indications and efficacy.

Wind on Mars is a significant agent of contemporary surface change, yet the absence of in situ meteorological data hampers the understanding of surface-atmospheric interactions. Airflow models at length scales relevant to landform size now enable examination of conditions that might activate even small-scale bedforms (ripples) under certain contemporary wind regimes. Ripples have the potential to be used as modern 'wind vanes' on Mars. Here we use 3D airflow modelling to demonstrate that local dune topography exerts a strong influence on wind speed and direction and that ripple movement likely reflects steered wind direction for certain dune ridge shapes. The poor correlation of dune orientation with effective sand-transporting winds suggests that large dunes may not be mobile under modelled wind scenarios. This work highlights the need to first model winds at high resolution before inferring regional wind patterns from ripple movement or dune orientations on the surface of Mars today.

Mollusk shells provide a hard substrate for aquatic biofilm colonization. While most work has focused on bivalve shells and grazing, little work has focused on gastropod shells and the microbes growing on them. We sampled biofilms from 14 Pleuroceracanaliculatum and analyzed them using a metagenomic approach. Microbial diversity varied between individuals, and rarefaction suggested that 63 snails would need to be sampled to capture all of the estimated genus-level diversity. Cyanobacteria and species of Novosphingobium and Methylosoma were the most abundant taxa across all shells.

Recent much-publicized increases in pertussis case reports in some countries with high vaccine coverage have raised concerns about its current and future control. The ubiquity of this trend, however, remains unexamined. In an attempt to paint a global picture, we used case counts to determine which countries experienced statistically significant trends in incidence over the past two decades and to map changes in incidence during this period. These data reveal that pertussis resurgence is not a universal phenomenon. The heterogeneity in incidence trends, even in countries with superficially similar demography, socioeconomic conditions and vaccination programmes, is striking and requires explanation. In this opinion piece, we review and assess the multifaceted proposed explanations incorporating evolution, population dynamics, and the details of immunization programmes. While we do not solve the riddle that is pertussis epidemiology, we highlight critical aspects that are likely to hold the key to understanding its worldwide epidemiology.

1. Recurring insulin-induced hypoglycaemia (RIIH) often occurs during the therapeutic management of insulin-dependent diabetes mellitus. Controversy currently exists in the literature as to the ability of insulin and/or hypoglycaemia to promote hypertension. Could insulin and/or hypoglycaemia promote adverse pressor effects? If so, under what conditions and through what mechanism? Thus, the present study was performed to evaluate the hypothesis that RIIH produces hypertension via induction of heme oxygenase (HO)-1, promoting a significant increase in endogenous carbon monoxide (CO). 2. Male Sprague-Dawley rats were treated for 2 weeks with varying doses of insulin (1, 3, 5, 7 and 9 U/kg, s.c.) or vehicle and fed normal rat chow or a zinc diet (1 mmol/L) for 2 weeks. Tail-cuff blood pressure, food intake and blood glucose states were monitored daily. 3. A dose-dependent decrease in blood glucose was observed in insulin-treated rats. Blood pressure was significantly elevated in rats treated with 9 and 7 U/kg insulin compared with those treated with other doses of insulin. However, there was no change in urine output among the groups. Feeding of a high-zinc diet to rats treated with 7 U/kg insulin and treatment with the HO-1 inhibitor zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG; 20 mg/kg) after insulin injection resulted in a significant reduction in blood pressure compared with 7 U/kg insulin injection alone. In addition, HO-1 protein levels in the heart and kidney and endogenous CO levels were reduced in 7 U/kg insulin-treated rats fed the high-zinc diet compared with those treated with the same dose of insulin alone. 4. The results of the present study demonstrate that RIIH promotes hypertension and that restoration of normal CO levels with a high-zinc diet and ZnDPBG reduces blood pressure., (© 2013 Wiley Publishing Asia Pty Ltd.)