Real-time deformability cytometry: on-the-fly cell mechanical phenotyping.

We introduce real-time deformability cytometry (RT-DC) for continuous cell mechanical characterization of large populations (>100,000 cells) with analysis rates greater than 100 cells/s. RT-DC is sensitive to cytoskeletal alterations and can distinguish cell-cycle phases, track stem cell differentiation into distinct lineages and identify cell populations in whole blood by their mechanical fingerprints. This technique adds a new marker-free dimension to flow cytometry with diverse applications in biology, biotechnology and medicine.

Immunity Against SARS-CoV-2 in the German Population.

BACKGROUND: Early during the SARS-CoV-2 pandemic, national population-based seroprevalence surveys were conducted in some countries; however, this was not done in Germany. In particular, no seroprevalence surveys were planned for the summer of 2022. In the context of the IMMUNEBRIDGE project, the GUIDE study was carried out to estimate seroprevalence on the national and regional levels. METHODS: To obtain an overview of the population-wide immunity against SARS-CoV-2 among adults in Germany that would be as statistically robust as possible, serological tests were carried out using self-sampling dried blood spot cards in conjunction with surveys, one by telephone and one online. Blood samples were analyzed for the presence of antibodies to the S and N antigens of SARS-CoV-2. RESULTS: Among the 15 932 participants, antibodies to the S antigen were detected in 95.7%, and to the N antigen in 44.4%. In the higher-risk age groups of persons aged 65 and above and persons aged 80 and above, anti-S antibodies were found in 97,4% and 98.8%, respectively. Distinct regional differences in the distribution of anti-S and anti-N antibodies emerged. Immunity gaps were found both regionally and in particular subgroups of the population. High anti-N antibody levels were especially common in eastern German states, and high anti-S antibody levels in western German states. CONCLUSION: These findings indicate that a large percentage of the adult German population has formed antibodies against the SARS-CoV-2 virus. This will markedly lower the probability of an overburdening of the health care system by hospitalization and high occupancy of intensive care units due to future SARS-CoV-2 waves, depending on the viral characteristics of then prevailing variants.

[Recommendation for standardized medical care for children and adolescents with long COVID]. / Einheitliche Basisversorgung von Kindern und Jugendlichen mit Long COVID: Stellungnahme einer multidisziplinären Arbeitsgruppe der DGKJ-Konvent-Gesellschaften (Stand: Februar 2022).

This current consensus paper for long COVID complements the existing AWMF S1 guidelines for long COVID with a detailed overview on the various clinical aspects of long COVID in children and adolescents. Members of 19 different pediatric societies of the DGKJ convent and collaborating societies together provide expert-based recommendations for the clinical management of long COVID based on the currently available but limited academic evidence for long COVID in children and adolescents. It contains screening questions for long COVID and suggestions for a structured, standardized pediatric medical history and diagnostic evaluation for patients with suspected long COVID. A time and resource-saving questionnaire, which takes the clinical complexity of long COVID into account, is offered via the DGKJ and DGPI websites as well as additional questionnaires suggested for an advanced screening of specific neurocognitive and/or psychiatric symptoms including post-exertional malaise (PEM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). According to the individual medical history as well as clinical signs and symptoms a step by step diagnostic procedure and a multidisciplinary therapeutic approach are recommended.

Clinical Practice Guideline: Sore Throat.

BACKGROUND: Sore throat is a common reason for consultation of primary care physicians, pediatricians, and ENT specialists. The updated German clinical practice guideline on sore throat provides evidence-based recommendations for treatment in the German healthcare system. METHODS: Guideline revision by means of a systematic search of the literature for international guidelines and systematic reviews. All recommendations resulted from interdisciplinary cooperation and were agreed by formal consensus. The updated guideline applies to patients aged 3 years and over. RESULTS: In the absence of red flags such as immunosuppression, severe comorbidity, or severe systemic infection, acute sore throat is predominantly self-limiting. The mean duration is 7 days. Chronic sore throat usually has noninfectious causes. Laboratory tests are not routinely necessary. Apart from non-pharmacological self-management, ibuprofen and naproxen are recommended for symptomatic treatment. Scores can be used to assess the risk of bacterial pharyngitis: one point each is assigned for tonsil lesions, palpable cervical lymph nodes, patient age, disease course, and elevated temperature. If the risk is low (<3 points), antibiotics are not indicated; if at least moderate (3 points), delayed prescribing is recommended; if high (>3 points), antibiotics can be taken immediately. Penicillin remains the first choice, with clarithromycin as an alternative for those who do not tolerate penicillin. The antibiotic should be taken for 5-7 days. CONCLUSION: After the exclusion of red flags, antibiotic treatment is unnecessary in many cases of acute sore throat. If administration of antibiotics is still considered in spite of consultation on the usual course of tonsillopharyngitis and the low risk of complications, a risk-adapted approach using clinical scores is recommended.

Cell Mechanics Based Computational Classification of Red Blood Cells Via Machine Intelligence Applied to Morpho-Rheological Markers.

Despite fluorescent cell-labelling being widely employed in biomedical studies, some of its drawbacks are inevitable, with unsuitable fluorescent probes or probes inducing a functional change being the main limitations. Consequently, the demand for and development of label-free methodologies to classify cells is strong and its impact on precision medicine is relevant. Towards this end, high-throughput techniques for cell mechanical phenotyping have been proposed to get a multidimensional biophysical characterization of single cells. With this motivation, our goal here is to investigate the extent to which an unsupervised machine learning methodology, which is applied exclusively on morpho-rheological markers obtained by real-time deformability and fluorescence cytometry (RT-FDC), can address the difficult task of providing label-free discrimination of reticulocytes from mature red blood cells. We focused on this problem, since the characterization of reticulocytes (their percentage and cellular features) in the blood is vital in multiple human disease conditions, especially bone-marrow disorders such as anemia and leukemia. Our approach reports promising label-free results in the classification of reticulocytes from mature red blood cells, and it represents a step forward in the development of high-throughput morpho-rheological-based methodologies for the computational categorization of single cells. Besides, our methodology can be an alternative but also a complementary method to integrate with existing cell-labelling techniques.

A standardized microdilution susceptibility test to determine the resistance capacity of human pathogenic bacteria towards hydrogen peroxide.

The susceptibility protocol established in this study takes into account that complex media are capable to buffer H2O2 which otherwise may adulterate test results. Furthermore, we demonstrate that clinical isolates of Staphylococcus aureus showed a higher resistance against H2O2 than Streptococcus pyogenes after 30 mins of incubation but not after 24 h.