Relationship between Rate of Force Development of Tongue Pressure and Physical Performance.

In the assessment of skeletal muscle strength, rate of force development (RFD) is clinically identified as a functional index that reflects the effects of aging, but there are few reports on RFD of the tongue. The purpose of this study was to examine the relationship between RFD of tongue pressure (RFD-TP) and oral and whole-body physical performance in older adults, and to clarify its characteristics. We enrolled adults aged ≥65 years with pathological occlusal contact in premolar and molar regions of teeth in the Tamba-Sasayama area, Japan, from 2017 to 2018. Maximum tongue pressure (MTP) and the speed to reach the maximum tongue pressure (RFD-TP) were evaluated as measures of tongue function. Oral functions related to objective measures of tongue function, such as repetitive saliva swallowing test, oral diadochokinesis, and physical status or performance, such as mini mental state examination, body mass index, skeletal mass index, knee extension force, one-leg standing time, grip strength, walking speed, timed up-and-go test, and five-time chair stand speed was evaluated. No significant correlation was found between MTP and age, but RFD-TP had a significant negative correlation with age. Neither RFD-TP nor MTP showed a significant correlation with oral function. RFD-TP was associated with physical performance, such as knee extension force and one-leg standing time. RFD-TP is more sensitive to aging than MTP. In addition, RFD-TP is related to physical performance and may be useful for the early detection of frailty.

Change in Nutritional Status and Dysphagia after Resection of Head and Neck Cancer.

Nutritional status is well-known to influence patient recovery after resection of head and neck cancer (HNC). The influence of preoperative nutritional status on dysphagia was assessed in patients who underwent surgical resection of HNC along with the assessment of nutritional status during the acute and subacute phases. Eighty-six patients underwent surgical resection and dysphagia assessments (repetitive saliva-swallowing test, water-swallowing test, and functional oral intake scale) and had their tongue pressure assessed five times (before surgery, after 1-2 weeks, and 1, 2, and 3 months after surgery). The nutritional status was assessed according to the body mass index, total protein, and albumin. The prognostic nutritional index was calculated from preoperative data, and the subjects were classified into three groups: Low-risk, Attention and High-risk groups. After surgery, the nutritional status index values were low, and the High-risk group showed significantly lower values in comparison to the other two groups. The water-swallowing test and functional oral intake scale findings were worse than they had been preoperatively until 2 months after surgery, and a significant correlation was noted between the postoperative nutritional status and the presence of dysphagia. The results indicated that the preoperative nutritional status of HNC patients influenced their ability to ingest/swallow, which in turn influenced their nutritional status after HNC resection.

Identification of Protease Specificity Using Biotin-Labeled Substrates.

BACKGROUND: Proteolysis constitutes a major post-translational modification. For example, proteases regulate the activation or inactivation of various proteins, such as enzymes, growth factors, and peptide hormones. Proteases have substrate specificity, and protease expression regulates the specific and regional activation or inactivation of several functional proteins. METHODS: We demonstrate a novel method for determining protease specificity through the use of MALDI-TOF mass spectrometry with biotin-labeled substrates. RESULTS: This method was able to determine the specificity of TPCK-trypsin, V8 protease, elastase and cyanogen bromide cleavage, and the results were similar to previous reports. In addition, the method can be used to measure crude samples, such as tumor extracts. CONCLUSION: We demonstrated that this method could identify protease specificity after simple processing, even for crude samples.