Peculiar Mammographic and Ultrasonographic Findings of a Retained Silastic Drain in the Breast

Foreign bodies, such as surgical sponges or drains, are sometimes retained after surgical procedures.1 Retention of a drain in the breast tissue postoperatively is an unusual complication. This report describes two cases of characteristic sonographic findings related to retained silastic drains following breast surgery

Mesenchymal Stem Cell-Derived Extracellular Vesicle Therapy for Stroke: Challenges and Progress

Stroke is the leading cause of physical disability among adults. Stem cells such as mesenchymal stem cells (MSCs) secrete a variety of bioactive substances, including trophic factors and extracellular vesicles (EVs), into the injured brain, which may be associated with enhanced neurogenesis, angiogenesis, and neuroprotection. EVs are circular membrane fragments (30 nm−1 μm) that are shed from the cell surface and harbor proteins, microRNAs, etc. Since 2013 when it was first reported that intravenous application of MSC-derived EVs in a stroke rat model improved neurological outcomes and increased angiogenesis and neurogenesis, many preclinical studies have shown that stem cell-derived EVs can be used in stroke therapy, as an alternative approach to stem cell infusion. Although scientific research regarding MSC-derived EV therapeutics is still at an early stage, research is rapidly increasing and is demonstrating a promising approach for patients with severe stroke. MSC therapies have already been tested in preclinical studies and clinical trials, and EV-mediated therapy has unique advantages over cell therapies in stroke patients, in terms of biodistribution (overcoming the first pass effect and crossing the blood-brain-barrier), cell-free paradigm (avoidance of cell-related problems such as tumor formation and infarcts caused by vascular occlusion), whilst offering an off-the-shelf approach for acute ischemic stroke. Recently, advances have been made in the understanding of the function and biogenesis of EVs and EVs therapeutics for various diseases. This review presents the most recent advances in MSC-derived EV therapy for stroke, focusing on the application of this strategy for stroke patients

Sleep and vaccine administration time as factors influencing vaccine immunogenicity

The immunogenicity of vaccines is affected by host, external, environmental, and vaccine factors; in addition, sleep or circadian rhythms may also have effects. With the use of vaccines to mitigate the coronavirus disease 2019 (COVID-19) pandemic, research is underway to clarify what time of the day is optimal for COVID-19 vaccination and how disturbances of circadian rhythms will affect the immunogenicity of the vaccine in shift workers. Studies on the relationship between sleep time and the immunogenicity of vaccines for influenza and hepatitis have demonstrated that less sleep time and sleep deprivation tended to adversely affect immunogenicity. In some studies, there were even sex differences in these effects. When comparing shift workers with disturbances in their circadian rhythms and those who only worked during the day, one study found less antibody formation in shift workers; however, further studies on the relationship between shift work and the immunogenicity of vaccines are needed. Studies on the relationship between vaccine administration time and immunogenicity have shown different results according to age and sex. Therefore, future studies on vaccine administration time and immunogenicity may require an individualized approach for each vaccine and each population to be vaccinated. There is accumulating evidence on the effects of sleep and vaccine administration time on the immunogenicity of vaccines. However, further studies are needed to determine whether the association between immunogenicity and circadian rhythms and vaccine administration time can be used as a basis to increase the immunogenicity for individual vaccines

Prevalence and Genetic Structures of Streptococcus pneumoniae Serotype 6D, South Korea

To determine prevalence and genetic structures of new serotype 6D strains of pneumococci, we examined isolates from diverse clinical specimens in South Korea during 1991–2008. Fourteen serotype 6D strains accounted for 10.4% of serogroup 6 pneumococci from blood, sputum, nasopharynx, and throat samples. Serotype 6D strains consisted of 3 sequence types