Photocatalytic Functionalization of Dehydroalanine-Derived Peptides in Batch and Flow

Unnatural amino acids, and their synthesis by the late-stage functionalization (LSF) of peptides, play a crucial role in areas such as drug design and discovery. Historically, the LSF of biomolecules has predominantly utilized traditional synthetic methodologies that exploit nucleophilic residues, such as cysteine, lysine or tyrosine. Herein, we present a photocatalytic hydroarylation process targeting the electrophilic residue dehydroalanine (Dha). This residue possesses an α,β-unsaturated moiety and can be combined with various arylthianthrenium salts, both in batch and flow reactors. Notably, the flow setup proved instrumental for efficient scale-up, paving the way for the synthesis of unnatural amino acids and peptides in substantial quantities. Our photocatalytic approach, being inherently mild, permits the diversification of peptides even when they contain sensitive functional groups. The readily available arylthianthrenium salts facilitate the seamless integration of Dha-containing peptides with a wide range of arenes, drug blueprints, and natural products, culminating in the creation of unconventional phenylalanine derivatives. The synergistic effect of the high functional group tolerance and the modular characteristic of the aryl electrophile enables efficient peptide conjugation and ligation in both batch and flow conditions.

Impact of Cancer in Patients Undergoing Transcatheter Aortic Valve Replacement: A Single-Center Study

Background

The use of transcatheter aortic valve replacement (TAVR) in cancer survivors and patients with active cancer (AC) in cancer survivors and patients with active cancer (AC) is expanding, suggesting a need to adjust the indications and risk assessment pre-TAVR.

Objectives

The purpose of this study was to determine the impact of cancer on peri-procedural complications and survival in a long-term, single-center cohort of patients treated with TAVR.

Methods

Patients treated with TAVR between January 2006 and December 2018 were grouped as follows: controls (patients without cancer), stable cancer (SC), and AC. The primary endpoints were peri-procedural complications and 30-day survival. A secondary endpoint was 10-year survival.

Results

A total of 1,088 patients (age 81 ± 5 years, 46.6% men) treated with transfemoral TAVR were selected: 839 controls, 196 SC, and 53 AC. Predominant malignancies were breast, gastrointestinal, and prostate cancer. No differences were observed between patients with cancer and controls regarding peri-procedural complications. Patients with AC had similar 30-day survival compared with controls and SC (94.3% vs. 93.3% vs. 96.9%, p = 0.161), but as expected, reduced 10-year survival. AC was associated with a 1.47 (95% CI 1.16 to 1.87) fold increased risk of all-cause 10-year mortality in multivariable adjusted models.

Conclusions

TAVR should be performed in patients with cancer when indicated, considering that patients with cancer have similar periprocedural complications and short-term survival compared with control patients. However, patients with AC have worse 10-year survival. Future studies are needed to define cancer-specific determinants of worse long-term survival.

Comparing skin characteristics and molecular markers of xerotic foot skin between diabetic and non-diabetic subjects: An exploratory study

BACKGROUND

Xerosis cutis of the feet is one of the most common skin conditions among type 2 diabetics. Whether skin dryness among diabetic patients is different from 'general' skin dryness is unclear. The overall aim was to compare the structure, function and molecular markers of dry and cracked foot skin between diabetics and non-diabetics.

METHODS

The foot skin of 40 diabetics and 20 non-diabetics was evaluated. A clinical assessment of skin dryness was performed and transepidermal water loss, stratum corneum hydration, skin surface pH, epidermal thickness, skin roughness, elasticity and structural stiffness were measured. Ceramides, natural moisturizing factors, histamines, proteins and molecular markers of oxidative stress were analyzed based on a non-invasive sampling method for collection of surface biomarkers.

RESULTS

The mean number of superficial fissures in the diabetic group was nearly three times higher than in the non-diabetic group (11.0 (SD 6.2) vs. 3.9 (SD 4.2)). The skin stiffness was higher in the diabetic group and the values of almost all molecular markers showed considerably higher values compared to non-diabetics. Malondialdehyde and glutathione were lower in the diabetic sample.

CONCLUSIONS

The high number of superficial fissures may be based on an increased stiffness of dry diabetic foot skin combined with different concentrations of molecular markers in the stratum corneum compared to dry foot skin of non-diabetics.

Correction: Prevalence and associated factors of skin cancer in aged nursing home residents: A multicenter prevalence study

[This corrects the article DOI: 10.1371/journal.pone.0215379.].

Prevalence and associated factors of skin cancer in aged nursing home residents: A multicenter prevalence study

Non-melanoma-skin cancer is an emerging clinical problem in the elderly, fair skinned population which predominantly affects patients aged older than 70 years. Its steady increase in incidence rates and morbidity is paralleled by related medical costs. Despite the fact that many elderly patients are in need of care and are living in nursing homes, specific data on the prevalence of skin cancer in home care and the institutional long-term care setting is currently lacking. A representative multicenter prevalence study was conducted in a random sample of ten institutional long-term care facilities in the federal state of Berlin, Germany. In total, n = 223 residents were included. Actinic keratoses, the precursor lesions of invasive cutaneous squamous cell carcinoma were the most common epithelial skin lesions (21.1%, 95% CI 16.2 to 26.9). Non-melanoma skin cancer was diagnosed in 16 residents (7.2%, 95% CI 4.5 to 11.3). None of the residents had a malignant melanoma. Only few bivariate associations were detected between non-melanoma skin cancer and demographic, biographic and functional characteristics. Male sex was significantly associated with actinic keratosis whereas female sex was associated with non-melanoma skin cancer. Smoking was associated with an increased occurrence of non-melanoma skin cancer. Regular dermatology check-ups in nursing homes would be needed but already now due to financial limitations, lack of time in daily clinical practice and limited number of practising dermatologists, it is not the current standard. With respect to the worldwide growing aging population new programs and decisions are required. Overall, primary health care professionals should play a more active role in early diagnosis of skin cancer in nursing home residents. Dermoscopy courses, web-based or smartphone-based applications and teledermatology may support health care professionals to provide elderly nursing home residents an early diagnosis of skin cancer.

[The Epidemiology of Pressure Ulcer in Germany: Systematic Review]

BACKROUND

Pressure ulcers are considered as indicators of the quality of care. The aim of this study was to provide a systematic review of the incidence and prevalence of pressure ulcers in Germany between 2010 and 2015.

METHODS

The databases PubMed, CINAHL, DIMDI, Web of Science, LIVIVO, Google, Google Scholar, as well as the publishers Springer and the Thieme were searched until the end of February 2016. The extracted data were monitored by two reviewers. A risk of bias assessment was conducted.

RESULTS

219 epidemiologic figures were found in 67 studies and documents. Most data were identified for the hospital setting. The majority of figures in long-term care was based on primary research. Considering sources of high methodological quality, prevalence in long-term care varied between 2% and 5% and between 2% to 4% in hospitals (category 2 and above). Routine data collections showed heterogeneous results from the hospital settings with prevalence from 0.07% to 4.37%. No incidence figures and no routine data collections were identified for ambulatory settings. Prevalence varied between 2 and 4% (including category 1).

CONCLUSION

Review results indicate that pressure ulcers are frequent within all health care settings in Germany. Disregarding methodological limitations, pressure ulcer prevalence is between 2% and 5% in long-term care patients. Due to the heterogeneity of the available data, generalizable statements are not possible for the hospital settings. Pressure ulcer prevalence is most likely at least 2%. Results indicate that pressure ulcer preventive measures need to be improved in Germany.