Haematoxylin and eosin staining identifies medium to large bacterial aggregates with a reliable specificity: A comparative analysis of follicular bacterial aggregates in axillary biopsies using peptide nucleic acid-fluorescence in situ hybridization and haematoxylin and eosin staining

Combined therapeutic use of umbilical cord blood serum and amniotic membrane in diabetic wounds

Diabetic wounds are hard-to-heal due to complex multifactorial dysregulation within the micro-environment, necessitating the development of novel regenerative approaches to stimulate healing. This study investigated whether the combined therapeutic application of two novel cellular tissue products, namely a decellularized collagen-rich amniotic membrane (AmR) and growth factor-rich umbilical cord blood serum (UCBS) could have a positive synergistic effect on long-term healing outcomes by stimulating both superficial wound closure and wound bed regeneration. Full thickness excisional wounds were induced on obese diabetic mice (B6.Cg-lepob/J, ob/ob, n = 23) and treated with either: 1) Standard wound care (control); 2) UCBS; 3) AmR or 4) UCBS + AmR. Macroscopic wound closure was assessed on days 0, 3, 7, 10 and 14 post wounding. To determine the potential impact on wound recurrence, endpoint analysis was performed to determine both the overall quality of healing histologically as well as the molecular state of the wounds on day 14 via proteomic analysis. The data demonstrated the presence of both healers and non-healers. Re-epithelization took place in the healers of all treatment groups, but underlying tissue regeneration was far more pronounced following application of the combined treatment (UCBS + AmR), suggesting improved quality of healing and potentially a reduced change of recurrence long term. In non-healers, wounds failed to heal due to excessive slough formation and a reduction in LTB4 expression, suggesting impaired antimicrobial activity. Care should thus be taken since the cellular tissue product therapy could pose an increased risk for infection in some patients.

Fresh Hemorrhages in Intestinal Resection Margins Are Associated with Unfavorable Clinical Outcomes in Preterm Infants with Necrotizing Enterocolitis with Surgical Intervention

BACKGROUND

Necrotizing enterocolitis (NEC) is a common disease in premature infants. If conservative treatment does not respond, surgical removal of the necrotic section of bowel is common practice. This study investigates whether there is a correlation between the histopathological findings and the postoperative clinical course of the children who have undergone surgery. To date, only a few detailed studies on a possible correlation have been published.

METHODS

The surgical specimens of 49 infants diagnosed with NEC in the years 2010-2019 were re-evaluated. The histologic specimens were examined for tissue viability and hemorrhage of the resection margins, peritonitis or perforation of the central resection segment. The groups were divided according to the clinical outcome: death, postoperative complications and patients without complications.

RESULTS

5 of 49 (10.2%) children died, 22 children (44.9%) required reoperation, while 22 (44.9%) had no complications. Univariate and multivariate analyses showed a significant association between fresh hemorrhage in the resection margins and postoperative outcome. In our data, correlation between the vitality of the resection margins or the extent of necrosis and the postoperative course was not seen.

CONCLUSION

This retrospective study shows a significant correlation between a fresh hematoma in the tissue of the resection margin and the clinical prognosis. Fresh bleeding in the resection margins was associated with increased morbidity with stenosis and possibly another surgical intervention. In contrast, no further correlation was found between the vitality of the tunica mucosae, the tunica muscularis or peritonitis in the resection margin or central part of the NEC specimen and the clinical course. In summary, it can be said that the presence of a fresh hematoma at the resection margin is significantly linked to a poorer clinical outcome for the infants with NEC surgery. Other histopathological findings of the surgical specimen with regard to the clinical course show now significant correlation and, therefore, the histological examination mainly serves the medico-legal documentation and quality assurance of the NEC operation.

Versatile Mechanically Tunable Hydrogels for Therapeutic Delivery Applications

Hydrogels provide a versatile platform for biomedical material fabrication that can be structurally and mechanically fine-tuned to various tissues and applications. Applications of hydrogels in biomedicine range from highly dynamic injectable hydrogels that can flow through syringe needles and maintain or recover their structure after extrusion to solid-like wound-healing patches that need to be stretchable while providing a selective physical barrier. In this study, a toolbox is designed using thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) polymeric matrices and nanocelluloses as reinforcing agent to obtain biocompatible hydrogels with altering mechanical properties, from a liquid injectable to a solid-like elastic hydrogel. The liquid hydrogels possess low viscosity and shear-thinning properties at 25 °C, which allows facile injection at room temperature, while they become viscoelastic gels at body temperature. In contrast, the covalently cross-linked solid-like hydrogels exhibit enhanced viscoelasticity. The liquid hydrogels are biocompatible and are able to delay the in vitro release and maintain the bioactivity of model drugs. The antimicrobial agent loaded solid-like hydrogels are effective against typical wound-associated pathogens. This work presents a simple method of tuning hydrogel mechanical strength to easily adapt to applications in different soft tissues and broaden the potential of renewable bio-nanoparticles in hybrid biomaterials with controlled drug release capabilities.

Differential mobility spectrometry classification of bacteria

Aim: Rapid identification of bacteria would facilitate timely initiation of therapy and improve cost–effectiveness of treatment. Traditional methods (culture, PCR) require reagents, consumables and hours to days to complete the identification. In this study, we examined whether differential mobility spectrometry could classify most common bacterial species, genera and between Gram status within minutes. Materials & methods: Cultured bacterial sample gaseous headspaces were measured with differential mobility spectrometry and data analyzed using k-nearest-neighbor and leave-one-out cross-validation. Results: Differential mobility spectrometry achieved a correct classification rate 70.7% for all bacterial species. For bacterial genera, the rate was 77.6% and between Gram status, 89.1%. Conclusion: Largest difficulties arose in distinguishing bacteria of the same genus. Future improvement of the sensor characteristics may improve the classification accuracy.