Methemoglobinemia and hemolytic anemia after COVID-19 infection without identifiable eliciting drug: A case-report.

We report a second case of methemoglobinemia and non-autoimmune hemolytic anemia after contracting the SARS-CoV-2 infection in the absence of an identifiable eliciting drug. A 35-year old male without previous known comorbidities was admitted after he was diagnosed with the COVID-19 infection and had large pulmonary involvement. Seven days later, he desaturated but was without any signs of respiratory distress. A check of arterial blood gas revealed normal partial pressure of oxygen and follow-up tests confirmed a methemoglobinemia diagnosis. Over the next few days, hemolysis was established after decreased levels of hemoglobin and increased levels of indirect bilirubin and lactate dehydrogenase. A hemolytic anemia investigation panel came back normal, including G6PD. A second G6PD test was ordered at the 5-month follow-up appointment and revealed decreased levels. Clinicians should thus be aware of possible false negative tests when testing for G6PD during hemolytic crisis. In addition, whether the COVID-19 infection alone would be responsible for this chain of events remains a challenging question.

Randomized clinical trial of four adhesion strategies in posterior restorations-18-month results.

PURPOSE: To evaluate the 18-month clinical performance of four adhesive strategies in posterior composite restorations placed in private practice. MATERIALS AND METHODS: Upon approval by an institutional review board, 144 restorations were inserted in 45 subjects (average age = 32.6) to treat caries lesions or to replace existing restorations in vital molars and premolars. The adhesives OptiBond FL (three-step etch-and-rinse), OptiBond SOLO Plus (two-step etch-and-rinse), OptiBond XTR (two-step self-etch), and OptiBond All-in One (one-step self-etch) were applied as per manufacturer's (Kerr Co.) instructions followed by a nanofilled resin composite (Filtek Z350XT, 3M ESPE) under rubber dam isolation. Restorations were evaluated at baseline and at 18 months using United States Public Health Service (USPHS)-modified criteria and high-resolution digital photographs. Statistical analyses included the McNemar and the Mann-Whitney non-parametric tests (p < 0.05). RESULTS: A total of 137 restorations were evaluated after 18 months. The number of alfa ratings did not change significantly from baseline to 18 months for any of the adhesion strategies. When the 18-month evaluation criteria were pooled by pairs of adhesives, none of the adhesives resulted in a significantly different number of alfa ratings for any of the criteria compared with the other adhesives. CONCLUSION: Bonding strategy did not influence the clinical performance of posterior composite restorations under the clinical conditions used in this study. CLINICAL SIGNIFICANCE: When used in ideal clinical conditions, the composition of current dentin adhesives may be more clinically relevant than their adhesion strategy.

Purification of capsular polysaccharide from Streptococcus pneumoniae serotype 23F by a procedure suitable for scale-up.

Streptococcus pneumoniae is a pathogenic encapsulated bacterium, which causes pneumonia, bacteraemia and meningitis. Capsular polysaccharide conjugated to a carrier protein has been widely used as a vaccine antigen. Serotype 23F is one of the prevalent worldwide pneumococci. A simple and efficient method for capsular polysaccharide serotype 23F purification that can easily be scaled-up was developed. This method consisted of using culture broth obtained by tangential microfiltration through a 0.22 microm membrane, broth microfiltrate concentration by tangential ultrafiltration in a 30 kDa spiral membrane, fractional ethanol precipitation (28-60%), nuclease and proteinase treatment, and concentration/diafiltration in a 30 kDa cassette membrane. The final polysaccharide recovery was 89%. The final protein and nucleotide contamination was 1.5% (w/w) and 0.3% (w/w) respectively. The final pure polysaccharide meets the requirements of the World Health Organization and residual proteinase was not found in the final product.