Decreased circulating dipeptidyl peptidase-4 enzyme activity is prognostic for severe outcomes in COVID-19 inpatients.

Aim: To investigate the serum circulating DPP4 activity in patients with COVID-19 disease. Materials & methods: Serum samples from 102 hospitalized COVID-19 patients and 43 post-COVID-19 plasma donors and 39 SARS-CoV-2 naive controls and their medical data were used. Circulating DPP4 activities according to different COVID-19 disease peak severity (WHO) groups at sampling and at peak were assessed. Results: A significant decrease (p < 0.0001) in serum DPP4 activity was found in study groups of higher disease severity. When the circulating DPP4 activity was assessed as a prognostic marker, the logistic regression (p = 0.0023) indicated that the enzyme activity is a predictor of mortality (median 9.5 days before death) with receiver operating characteristic area under the curves of 73.33% (p[area = 0.5] < 0.0001) as single predictor and 83.45% (p[area = 0.5] < 0.0001) in combination with age among hospitalized patients with COVID-19. Conclusion: Decreased circulating DPP4 activity is associated with severe COVID-19 disease and is a strong prognostic biomarker of mortality.

Polymethyl-methacrylate-sorbitol-based capsules as local drug delivery vehicles: an in vitro antibiotic elution study.

A PMMA (polymethyl-methacrylate)-sorbitol-based capsule system was recently developed, and the permeability of 16 types of capsules with different wall thicknesses and sorbitol contents tested. By optimizing these two parameters, we showed that capsule permeability could be controlled. Promising preliminary data obtained using BPB (Bromophenol Blue) as diffusion marker prompted us to further investigate the antibiotic release of capsules showing the most appropriate release characteristics. PMMA-sorbitol capsules were prepared with wall thickness of 0.5 or 0.6 mm and 60 or 70 w/w% (weight percent) of sorbitol content. In vitro gentamicin, amikacin, tobramycin releases were determined by using a microbiological agar plate diffusion assay. Capsules released 70-100% of their gentamicin load, substantially superior to Septopal, and showed preferable, extended release profiles when compared with the beads. The release kinetics of amikacin and tobramycin closely resembled those of gentamicin. PMMA-sorbitol capsules have been developed and tested, which make them promising devices for local antibiotic delivery.

Polymethyl-methacrylate-sorbitol-based capsules as local drug delivery vehicles: a preliminary study.

Local delivery of antibiotics via PMMA (polymethyl-methacrylate) has been widely used in the treatment of chronic osteomyelitis for over 40 years. Unfortunately, PMMA is water insoluble, which seriously limits antibiotic delivery. In addition, the polymerization temperature of PMMA is high, and consequently, only heat-stable antibiotics can be used. Therefore our aim has been to develop an effective antibiotic delivery system, which can be loaded with a wide variety of drugs and deliver the molecules in a predictable manner. Capsules with wall thicknesses of 0.3-0.6 mm from PMMA mixtures containing 40-70 w/w% (weight percent) of sorbitol were prepared and their permeability tested with BPB (Bromophenol Blue). Sorbitol content and wall thickness correlated with the BPB release. SEM (scanning electron microscopy) showed that the canalization of capsules also was well correlated with both sorbitol content and wall thickness. The PMMA-sorbitol-based capsule can potentially be a versatile tool in assuring effective delivery of antibiotics and other substances.

Osteoscopy for assessment of blood supply to the femoral head: a preliminary study.

OBJECTIVES: The aim of our study was to develop a minimally invasive endoscopic procedure (osteoscopy), which is capable of visualizing blood supply and quantitatively assessing circulation to the femoral head at the time of definitive surgery. METHODS: The new diagnostic technique was developed in animal experiments (four piglets) and was subsequently tested in nine consecutive patients requiring surgery for a femoral neck fracture. The direct visualization of the femoral head circulation was performed in the mortise prepared for the implant. The osteoscope optic fiber was placed at the orifice of the cavity created by the custom-made drill bit. The "mortise-sleeve-optic" system was connected to a manometer and a saline reservoir. The bleeding from the wall of bony cavity was observed, meanwhile the inner pressure of the "mortise-sleeve-optic" system was changed gradually. The pressure measurement at the first appearance of bleeding and the intraosseal pressure was recorded. RESULTS: The animal investigations demonstrated that the osteoscopy readily distinguished among diffuse bleeding, pulsatile bleeding, and the absence of bleeding in the femoral head. The human experiments proved that a different quality of the femoral head circulation can be observed during osteoscopy. CONCLUSIONS: Preliminary findings indicate that clinical osteoscopy may be a useful tool in the assessment of blood circulation to the femoral head.