Pneumothorax with Bullous Lesions as a Late Complication of Covid-19 Pneumonia: A Report on Two Clinical Cases.

BACKGROUND: Coronavirus-19 disease (COVID-19) primarily affects the respiratory tract, causing viral pneumonia with fever, hypoxemia, and cough. Commonly observed complications include acute respiratory failure, liver or kidney injury, and cardiovascular or neurologic symptoms. In some patients, inflammatory damage results in long-term complications, such as pulmonary fibrosis, chronic pulmonary thrombotic microangiopathy, or neurologic symptoms. The development of spontaneous pneumothorax is reported as a rare complication mainly in consequence to mechanic ventilation in the criticall ill. CASE REPORT: We report 2 cases of patients with COVID-19 pneumonia complicated by spontaneous pneumothorax and bullous lesions of the lung. Bilateral giant bullae were observed in 1 of the cases. This complication occurred after an initial resolvement of respiratory symptoms (day 16 and day 29 after COVID-19 treatment was started). Initially, both patients had shown a rather mild course of COVID-19 pneumonia and no mechanical ventilatory support had been necessary. Why Should an Emergency Physician Be Aware of This?: In both cases, COVID-19 caused alveolar damage and the formation of thoracic bullae with consequent spontaneous pneumothorax as a serious complication. Emergency physicans must be aware of this complication even if the initial COVID-19 symptoms have resolved. © 2021 Elsevier Inc.

Coronavirus disease (COVID-19): observations and lessons from primary medical care at a German community hospital.

The pandemic outbreak of COVID-19 challenges medical care systems all around the world. We here describe our experiences during the treatment of COVID-19 patients (n = 42) treated from 2 March 2020 to 16 April 2020 at a German district hospital. Forty-two COVID-19 patients were hospitalized and five patients developed a severe disease, requiring intensive care. Overall, 11 out of 42 hospitalized patients died. COVID-19 caused lymphocytopenia, as well as increased d-dimer, c-reactive protein and creatine kinase, and lactate dehydrogenase levels. These changes were mostly pronounced in patients that developed a severe disease course. Radiologic findings included ground-glass opacity, bilateral/multilobular involvement, consolidation, and posterior involvement. We compared COVID-19 patients to an average population of 'non-COVID' patients. Interestingly, no laboratory or radiologic finding was specific for COVID-19 when standing alone, as comorbidities of 'non-COVID' patients certainly can mimic similar results. In common praxis, the diagnosis of COVID-19 is based on a positive PCR result. However, a false-negative result causes problems for the workflow of an entire hospital. In our clinic, the consequences of a false assumption of SARS-CoV-2 negativity in four cases had dramatic consequences, as contact persons had to be quarantined. To avoid this, a comprehensive view of lab-results, radiology, clinical symptoms and comorbidities is necessary for the correct diagnosis or exclusion of COVID-19.

In vitro reaction of human osteoblasts on alumina-toughened zirconia.

OBJECTIVES: Alumina toughening enhances the mechanical properties of zirconia ceramics but the biocompatibility of this material has rarely been addressed. In this study, we examined the osteoblast response to alumina-toughened zirconia (ATZ) with different surface topographies. MATERIAL AND METHODS: Human osteoblasts isolated from maxillary biopsies of four patients were cultured and seeded onto disks of the following substrates: ATZ with a machined surface, airborne-particle abraded ATZ, airborne-particle abraded and acid etched ATZ. Airborne-particle abraded and acid etched titanium (SLA) and polystyrene disks served as a reference control. The surface topography of the various substrates was characterized by profilometry (R(a), R(p-v)) and scanning electron microscopy (SEM). Cell proliferation, cell-covered surface area, alkaline phophatase (ALP) and osteocalcin production were determined. The cell morphology was analyzed on SEM images. RESULTS: The surface roughness of ATZ was increased by airborne-particle abrasion, but with the R(a) and R(p-v) values showing significantly lower values compared with SLA titanium (Mann-Whitney U-test P<0.05). The proliferation assay revealed no statistically significant differences between the ATZ substrates, SLA titanium and polystyrene (Kruskal-Wallis test, P>0.05). All substrates were densely covered by osteoblasts. ALP and osteocalcin production was similar on the examined surfaces. Cell morphology analysis revealed flat-spread osteoblasts with cellular extensions on all substrates. CONCLUSIONS: These results indicate that ATZ may be a viable substrate for the growth and differentiation of human osteoblasts. Surface modification of ATZ by airborne-particle abrasion alone or in combination with acid etching seems not to interfere with the growth and differentiation of the osteoblasts.

Comparative in vitro study of the proliferation and growth of ovine osteoblast-like cells on various alloplastic biomaterials manufactured for augmentation and reconstruction of tissue or bone defects.

In this in vitro study ovine osteoblast-like cells were cultured on seven different alloplastic biomaterials used for augmentation and for reconstruction of bone defects in dental and craniomaxillofacial surgery. The aim of this study was to examine the growth behaviour (viability, cell density and morphology) of ovine osteoblast-like cells on the investigated biomaterials to get knowledge which biomaterial is qualified to act as a cell carrier system in further in vivo experiments. The biomaterials were either synthetically manufactured or of natural origin. As synthetically manufactured biomaterials Ethisorb, MakroSorb, PalacosR, and PDS film were used. As biomaterials of natural origin BeriplastP, Bio-Oss and Titanmesh were investigated. The cell proliferation and cell colonization were analyzed by a proliferation assay and scanning electron microscopy. Osteoblast-like cells proliferated and attached on all biomaterials, except on Beriplast. On Ethisorb the highest cell proliferation rate was measured followed by PalacosR. Both biomaterials offer suitable growth and proliferation conditions for ovine osteoblast-like cells. The proliferation rates of Bio-Oss, MakroSorb, PDS-film and Titanmesh were low and SEM examinations of these materials showed less spread osteoblast-like cells. The results showed that ovine osteoblast-like cells appear to be sensitive to substrate composition and topography. This in vitro study provides the basis for further in vivo studies using the sheep model to examine the biocompatibility and the long-term interaction between the test material and tissue (bone regeneration).