Molecular mechanisms and promising role of dihydromyricetin in cardiovascular diseases.

Vine tea, a Chinese herbal medicine, is widely used in traditional Asian medicine to treat common health problems. Dihydromyricetin (DMY) is the main functional flavonoid compound extracted from vine tea. In recent years, preclinical studies have focused on the potential beneficial effects of dihydromyricetin, including glucose metabolism regulation, lipid metabolism regulation, neuroprotection, and anti-tumor effects. In addition, DMY may play a role in cardiovascular disease by resisting oxidative stress and participating in the regulation of inflammation. This review is the first review that summaries the applications of dihydromyricetin in cardiovascular diseases, including atherosclerosis, myocardial infarction, myocardial hypertrophy, and diabetic cardiomyopathy. We also clarified the underlying mechanisms and signaling pathways involved in the above process. The aim of this review is to provide a better understanding and quick overview for future researches of dihydromyricetin in the field of cardiovascular diseases, and more detailed and robust researches are needed for evaluation and reference.

Free flap reconstruction in paediatric patients with head and neck cancer: clinical considerations for comprehensive care.

Free flap reconstruction after resection in paediatric patients with head and neck cancer (HNC) has various clinical challenges, which have not yet been fully investigated. This retrospective study was implemented to investigate these factors. Paediatric patients (≤14 years old) who underwent free flap reconstructions following surgery for HNC at a tertiary referral centre during the years 2009-2018 were included. Clinical, pathological, and imaging data were collected and analysed. Overall, 47 patients were included, 26 male and 21 female. Thirty-four patients were ASA status I and 13 were ASA status II. The median operative time was 415 minutes, while the median intraoperative blood loss was 500 ml. Seventeen patients had a tracheotomy. Fourteen medical complications (six pulmonary infection, six diarrhoea, two pulmonary aspiration) and six surgical complications (one haematoma beneath flap, two wound dehiscence, one salivary fistula, one effusion, one tracheotomy haemorrhage) were observed. Tracheotomy was associated with medical complications (P = 0.003) and total complications (P = 0.024). It was confirmed that microvascular reconstruction can be adopted in paediatric HNC patients, while tracheotomy and nasal feeding tubes should be used with caution. Comprehensive preoperative assessment, gentle handling of the tissues during operative procedures, and appropriate postoperative management will reduce the risk of complications.

Free flap reconstruction for patients aged 85 years and over with head and neck cancer: clinical considerations for comprehensive care.

We aimed to identify and evaluate the clinical challenges involved in microvascular flap reconstructions of defects caused by resection of head and neck cancer among patients aged 85 and over. We designed a retrospective study of patients who were treated in the head and neck department of a tertiary referral centre from 2005 to 2015, and all patients aged 85 years and over who had reconstructions with microvascular flaps for head and neck cancer were entered into the study. A total of 24 patients fulfilled the criteria, of whom 15 were men and nine were women. The median (range) duration of stay in hospital was 23 (14-59) days. Eighteen patients had an American Society of Anesthesiologists (ASA) score grade II and six patients grade III. The median (range) operating time was 420 (310-705)minutes, and operative blood loss 550 (200-1500)ml. Sixteen patients had prophylactic tracheostomies, nine of whom developed postoperative surgical complications, seven associated with the tracheostomy (p=0.005). Resections of head and neck cancer and microvascular reconstructions in patients aged 85 and over are associated with a high incidence of postoperative complications. Medical complications tend to be associated with the tracheostomy while surgical complications are potentially associated with the ASA score. Although the morbidity is high, complex resections and microvascular reconstructions are successful with optimum recovery, and age did not seem to influence the outcome. However, it is necessary to avoid prophylactic tracheostomy if possible in these patients.

Lys91 and His90 of the alpha-subunit are crucial for receptor binding and hormone action of follicle-stimulating hormone (FSH) and play hormone-specific roles in FSH and human chorionic gonadotropin.

Glycoprotein hormones, FSH, LH, CG, and TSH, consist of a common alpha-subunit and a hormone-specific beta-subunit. Both subunits are thought to interact with the hormone receptors. Although several C-terminal residues of hCG alpha are known to contact the LH/CG receptor, little is known about the roles of individual C-terminal residues of FSH alpha. In this report, substitutions of various amino acids for the penultimate Lys91 and the upstream His90 of the alpha-subunit demonstrate that these two residues of FSH alpha are important for high affinity receptor binding and hormone action to induce cAMP production. In contrast, the same residues of hCG alpha are more important for cAMP induction than for high affinity receptor binding. Some substitutions significantly improved receptor binding of FSH and hCG, whereas others were detrimental. Some had the same effect on both hormones, and others impacted differently. Particularly, the substitution of Val for alpha Lys91 resulted in an improved receptor binding of and a loss of cAMP induction by FSH and hCG. On the other hand, the substitution of Arg or Pro for alpha His90 abolished receptor binding of FSH, but not of hCG. These results allowed us to generate an antagonist to FSH. Our results indicate that alpha His90 and alpha Lys91 play roles in receptor binding and cAMP induction of FSH and hCG in strikingly different ways. They will be useful to elucidate the underlying mechanisms for the interaction of FSH and hCG with their complementary receptors as well as for receptor activation.