Microbial responses to soil cooling might explain increases in microbial biomass in winter.

In temperate, boreal and arctic soil systems, microbial biomass often increases during winter and decreases again in spring. This build-up and release of microbial carbon could potentially lead to a stabilization of soil carbon during winter times. Whether this increase is caused by changes in microbial physiology, in community composition, or by changed substrate allocation within microbes or communities is unclear. In a laboratory incubation study, we looked into microbial respiration and growth, as well as microbial glucose uptake and carbon resource partitioning in response to cooling. Soils taken from a temperate beech forest and temperate cropland system in October 2020, were cooled down from field temperature of 11 °C to 1 °C. We determined microbial growth using 18O-incorporation into DNA after the first two days of cooling and after an acclimation phase of 9 days; in addition, we traced 13C-labelled glucose into microbial biomass, CO2 respired from the soil, and into microbial phospholipid fatty acids (PLFAs). Our results show that the studied soil microbial communities responded strongly to soil cooling. The 18O data showed that growth and cell division were reduced when soils were cooled from 11 to 1 °C. Total respiration was also reduced but glucose uptake and glucose-derived respiration were unchanged. We found that microbes increased the investment of glucose-derived carbon in unsaturated phospholipid fatty acids at colder temperatures. Since unsaturated fatty acids retain fluidity at lower temperatures compared to saturated fatty acids, this could be interpreted as a precaution to reduced temperatures. Together with the maintained glucose uptake and reduced cell division, our findings show an immediate response of soil microorganisms to soil cooling, potentially to prepare for freezing events. The discrepancy between C uptake and cell division could explain previously observed high microbial biomass carbon in temperate soils in winter. Supplementary Information: The online version contains supplementary material available at 10.1007/s10533-023-01050-x.

The hybrid approach for reconstruction of severely destructed lower eyelids: combination of skin grafting, temporary tarsorrhaphy, and autologous fat grafting for cicatricial ectropion after injection of commercial grade silicone.

BACKGROUND: Although silicone injections for permanent soft tissue augmentation were popular in the past, their use has become unduly controversial because of severe complications, mainly caused by injection of illegal silicones by unlicensed practitioners. The delicate local anatomy of the lower eyelid region makes this region particularly susceptible for complications after silicone augmentation including local inflammation, tissue retraction, and consecutive cicatricial ectropion leading to lagophthalmus and ocular surface irritation. CLINICAL REPORT: This is a case of a 47-year-old patient demonstrating severe lower eyelid destruction with consecutive ectropion after injection of commercial grade silicone in Thailand 5 years prior, leading to chronic granulomatous infections requiring multiple surgical interventions.Our hybrid approach included radical debridement with complete elimination of silicone residues, lateral canthopexy, reconstruction of the entire lower eyelid esthetic unit using a supraclavicular full-thickness skin graft, and temporary tarsorrhaphy followed by 2 sessions of autologous fat graft injections.Although many previous publications mainly focus on individual aspects of lower eyelid reconstruction, we describe a staged reconstructive approach for correction of severely destructed lower eyelid defects with consecutive lower eyelid ectropion. CONCLUSIONS: The hybrid approach presented here has proven to be a viable surgical strategy for lower eyelid reconstruction, with esthetically appealing results.

Functional characterization of cultured keratinocytes after acute cutaneous burn injury.

BACKGROUND: In addition to forming the epithelial barrier against the outside environment keratinocytes are immunologically active cells. In the treatment of severely burned skin, cryoconserved keratinocyte allografts gain in importance. It has been proposed that these allografts accelerate wound healing also due to the expression of a favourable--keratinocyte-derived--cytokine and growth factor milieu. METHODS: In this study the morphology and cytokine expression profile of keratinocytes from skin after acute burn injury was compared to non-burned skin. Skin samples were obtained from patients after severe burn injury and healthy controls. Cells were cultured and secretion of selected inflammatory mediators was quantified using Bioplex Immunoassays. Immunohistochemistry was performed to analyse further functional and morphologic parameters. RESULTS: Histology revealed increased terminal differentiation of keratinocytes (CK10, CK11) in allografts from non-burned skin compared to a higher portion of proliferative cells (CK5, vimentin) in acute burn injury. Increased levels of IL-1α, IL-2, IL-4, IL-10, IFN-γ and TNFα could be detected in culture media of burn injury skin cultures. Both culture groups contained large amounts of IL-1RA. IL-6 and GM-CSF were increased during the first 15 days of culture of burned skin compared to control skin. Levels of VEGF, FGF-basic, TGF-ß und G-CSF were high in both but not significantly different. Cryoconservation led to a diminished mediator synthesis except for higher levels of intracellular IL-1α and IL-1ß. CONCLUSION: Skin allografts from non-burned skin show a different secretion pattern of keratinocyte-derived cytokines and inflammatory mediators compared to keratinocytes after burn injury. As these secreted molecules exert auto- and paracrine effects and subsequently contribute to healing and barrier restoration after acute burn injury therapies affecting this specific cytokine/growth factor micromilieu could be beneficial in burned patients.

Laparoscopic sleeve gastrectomy: a guide to postoperative anatomy and complications.

The purpose of this pictorial essay is to review the surgical technique, postoperative anatomy, and potential complications of the laparoscopic sleeve gastrectomy. As the laparoscopic sleeve gastrectomy becomes an increasingly popular bariatric surgery, it is important for radiologists to familiarize themselves with the procedure and possible complications.