The effect of respiratory activity,non-invasive respiratory support and facemasks on aerosol generation and its relevance to COVID-19

Respirable aerosols (< 5 µm in diameter) present a high risk of SARS-CoV-2 transmission. Guidelines recommend using aerosol precautions during aerosol-generating procedures, and droplet (> 5 µm) precautions at other times. However, emerging evidence indicates respiratory activities may be a more important source of aerosols than clinical procedures such as tracheal intubation. We aimed to measure the size, total number and volume of all human aerosols exhaled during respiratory activities and therapies. We used a novel chamber with an optical particle counter sampling at 100 l.min^-1 to count and size-fractionate close to all exhaled particles (0.5–25 µm). We compared emissions from ten healthy subjects during six respiratory activities (quiet breathing; talking; shouting; forced expiratory manoeuvres; exercise; and coughing) with three respiratory therapies (high-flow nasal oxygen and single or dual circuit non-invasive positive pressure ventilation). Activities were repeated while wearing facemasks. When compared with quiet breathing, exertional respiratory activities increased particle counts 34.6-fold during talking and 370.8-fold during coughing (p < 0.001). High-flow nasal oxygen 60 at l.min^-1 increased particle counts 2.3-fold (p = 0.031) during quiet breathing. Single and dual circuit non-invasive respiratory therapy at 25/10 cm.H₂O with quiet breathing increased counts by 2.6-fold and 7.8-fold, respectively (both p < 0.001). During exertional activities, respiratory therapies and facemasks reduced emissions compared with activities alone. Respiratory activities (including exertional breathing and coughing) which mimic respiratory patterns during illness generate substantially more aerosols than non-invasive respiratory therapies, which conversely can reduce total emissions. We argue the risk of aerosol exposure is underappreciated and warrants widespread, targeted interventions.     

Three-year outcomes from the CRADLE study in de novo pediatric kidney transplant recipients receiving everolimus with reduced tacrolimus and early steroid withdrawal

CRADLE was a 36-month multicenter study in pediatric (≥1 to <18 years) kidney transplant recipients randomized at 4 to 6 weeks posttransplant to receive everolimus + reduced-exposure tacrolimus (EVR + rTAC; n = 52) with corticosteroid withdrawal at 6-month posttransplant or continue mycophenolate mofetil + standard-exposure TAC (MMF + sTAC; n = 54) with corticosteroids. The incidence of composite efficacy failure (biopsy-proven acute rejection [BPAR], graft loss, or death) at month 36 was 9.8% vs 9.6% (difference: 0.2%; 80% confidence interval: −7.3 to 7.7) for EVR + rTAC and MMF + sTAC, respectively, which was driven by BPARs. Graft loss was low (2.1% vs 3.8%) with no deaths. Mean estimated glomerular filtration rate at month 36 was comparable between groups (68.1 vs 67.3 mL/min/1.73 m²). Mean changes (z-score) in height (0.72 vs 0.39; P = .158) and weight (0.61 vs 0.82; P = .453) from randomization to month 36 were comparable, whereas growth in prepubertal patients on EVR + rTAC was better (P = .050) vs MMF + sTAC. The overall incidence of adverse events (AEs) and serious AEs was comparable between groups. Rejection was the leading AE for study drug discontinuation in the EVR + rTAC group. In conclusion, though AE-related study drug discontinuation was higher, an EVR + rTAC regimen represents an alternative treatment option that enables withdrawal of steroids as well as reduction of CNIs for pediatric kidney transplant recipients. ClinicalTrials.gov: NCT01544491.     

Analysis of Treatment Results for Floor‐of‐Mouth Cancer

Objective This study reports the results of treating floor‐of‐mouth cancer with five different treatment modalities with long‐term follow‐up. Study Design Retrospective study of 280 patients with floor‐of‐mouth cancer treated in the Department of Otolaryngology—Head and Neck Surgery at Washington University Medical School (St. Louis, MO) from 1960 to 1994. Methods Patients with biopsy‐proven squamous cell carcinoma of the floor of mouth who were previously untreated were treated with curative intent by one of five modalities and were all eligible for 5‐year follow‐up. The treatment modalities included local resection alone, composite resection alone (with neck dissection), radiation therapy alone, local resection with radiation therapy, and composite resection with radiation therapy. Multiple diagnostic, treatment, and follow‐up parameters were studied using standard statistical analysis to determine statistical significance. Results The overall 5‐year disease‐specific survival (DSS) was 56% with death due to tumor in 44% of patients. The 5‐year cumulative disease‐specific survival (CDSS) was 0.61 (Kaplan‐Meier probability) with a mean of 8.3 years and a median of 9.7 years. The DSS by treatment modality included local resection (76%), composite resection (63%), radiation therapy (43%), local resection with radiation therapy (61%), and composite resection with radiation therapy (55%). Overall, there was no significant difference in DSS by treatment modality. Recurrence at the primary site (41%) was the most common site of treatment failure. Nineteen percent of patients had recurrence in the neck. Eighty‐eight percent of initial recurrences occurred within 60 months after the onset of treatment. Metastasis to a distant site occurred in 30% of patients. Twenty percent of these patients had second primary cancers, and 53% of these patients died of their second primary cancers. Conclusions Significantly improved 5‐year DSS was seen in the patients with clear margins, early clinical tumor stage, and negative nodes. Significantly decreased 5‐year survival was seen in the patients with involved margins, advanced clinical tumor stage, positive nodes, and tumor recurrence. Patients with no clinically positive nodes (cN0) can be observed safely for regional nodal disease and subsequent positive nodes can be treated as they occur with no adverse affect on survival. Because of high recurrence rates at the primary site and neck, and an increased rate of both distant metastasis and the development of second primary cancers, patients should be monitored closely for a minimum of at least 5 years.     

Symptoms in children of British and of Bangladeshi parents measured by the Rutter B2 questionnaire

Objectives. Bangladeshi children are less frequently referred to a child psychiatric clinic than their British peers. This study aimed to ascertain if teachers observed less psychological symptoms in Bangladeshi than British children.

Method. Teachers completed a Rutter B2 Scale on samples of 113 ‘Bangladeshi’ and 61 British children aged between 5 and 11 years.

Results. Teachers recognised less symptomatology in the Asian children than their British peers. This trend was significant in children under the age of 8, but there was no significant difference in those aged 8–11 years. Only 13% of Bangladeshi children were fully fluent in English.

Conclusions. Two alternate hypotheses are put forward to explain these findings: (a) because more of the younger children could not speak English and communicate freely with their teachers, their symptoms were not noted by teachers; (b) the symptoms of the older children were a response to the pressures both the children and families faced as new immigrants. This study clearly needs to be replicated with a larger sample and also with interviews with both children and parents in order to validate the Rutter B2 questionnaires as an appropriate measure of disturbance in Bangladeshi children. It should be replicated with validated assessments of the children's fluency in English. It is also important to discuss with Bangladeshi parents what support they would like from both the school and from child psychiatric services, to promote their children's psychological health.     

Cannabis laws: an analysis of costs

There is evidence that the use of cannabis is increasing in Australia, with stable black-market prices, despite the 9-year National Campaign Against Drug Abuse, increasing expenditure to enforce the laws against cannabis use, and the seizure of large plantations of cannabis plants. Recent government data are used to estimate the conservative cost of drug-law enforcement against cannabis use as being $329m in 1991-92. Alternatives to the existing regime are examined, including expiation, decriminalization, and legalization.     

Intussusception of the catheter sheath: A nonemergency

Percutaneous balloon dilatation angioplasty is a common therapeutic modality in patients with congenital heart disease. We report three cases of the catheter sheath telescoping into the hub of the sheath after removal of the balloon catheter. Although initially it appeared as though the sheath was torn, in actuality it was intact. We report this problem so others can avoid needless searching and concern for the missing catheter tip.     

Treatment of infected left ventricular assist device using antibiotic-impregnated beads

There is no well-established therapy for treating infections of heart-assist or artificial heart devices, a serious problem with life-threatening consequences. We used a promising new approach in which antibiotic-impregnated polymethylmethacrylate beads were placed around an implanted left ventricular assist device to control an external blood pump infection in a bridge-to-transplant patient. In this case report, we describe the potential of antimicrobial-impregnated polymethylmethacrylate beads for in situ control of infections involving external surfaces of cardiovascular devices.     

Papillary clear cell adenocarcinoma of the groin arising from endometriosis

A 67-year-old woman presented with rapidly enlarging right anterior thigh mass. Clinical impression was of a primary sarcoma, but the histologic analysis of an incisional biopsy specimen showed adenocarcinoma with clear cell differentiation. Initially thought to be a metastasis, the malignant tumor appears to have arisen from extraabdominal endometriosis of the right groin. This case shows clinical, radiographic, and histologic findings that may help the orthopaedic surgeon recognize an unusual complication of extrapelvic endometriosis.     

Long-term effects of finasteride on prostate tissue composition

OBJECTIVES: To determine the long-term effects of finasteride treatment on prostate tissue composition; to relate these effects to clinical outcomes; and to test the hypothesis that finasteride exerts a selective or preferential action on the transition zone. METHODS: Nineteen men with symptomatic benign prostatic hyperplasia (BPH) who completed a 6-month double-blind trial of finasteride were enrolled in a 24-month open-label extension study of drug responders. Magnetic resonance imaging and prostate biopsy for morphometric analysis were performed together 70 times: at baseline (n = 19), after treatment periods of intermediate duration (6 to 18 months, n = 32), and after long-term drug treatment (24 to 30 months, n = 19). At baseline, prostate volume averaged 51 cc, of which 57% was transition zone. RESULTS: Decreases in symptom score, dihydrotestosterone and prostate-specific antigen levels, and prostate volume occurred at 6 months (P <0.01), stabilized, and were maintained without further long-term decreases. Prostate epithelium contracted progressively from baseline (19.2% tissue composition; 6.0-cc volume; 3.2 stroma/epithelial ratio) to intermediate (12.5%, 3.3 cc, and 5.6, respectively) to long-term treatment (6.4%, 2.0 cc, and 17.4, respectively, P <0.01 for all). Percent epithelial contraction was similar in the peripheral and transition zones (P = NS). The transition zone remained a relatively constant proportion (53% to 58%) of whole-prostate volume from baseline to long-term observation. CONCLUSIONS: Long-term finasteride treatment (24 to 30 months) results in a marked involution of the prostate epithelium, which continues to progress for many months after clinical effects stabilize. The effect on the epithelium is similar in the peripheral and transition zones for both morphometric and volumetric changes. Progressive contraction of the prostate epithelium appears to constitute the underlying mechanism for sustained action of finasteride.