ABSTRACT
Chronic wounds are with characteristics of long last time and cannot heal in time, which is a problem in clinic. Wound pH value plays an important role in the process of healing of chronic wounds. In this paper, we review the relative researches on wound pH value and wound microenvironment, summarize the potential relationship between wound pH value and healing of chronic wounds, as well as the method to change pH value of chronic wounds, thereby to provide theoretical basis for the treatment of chronic wounds in clinic.
ABSTRACT
Objective@#To explore the expression levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein and the change of MMP-9/TIMP-1 ratio in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers during wound healing.@*Methods@#From July 2017 to July 2018, 30 patients with stage Ⅲ pressure ulcers [30 wounds, 16 males and 14 females, aged (65±10) years] and 34 patients with stage Ⅳ pressure ulcers [50 wounds, 17 males and 17 females, aged (65±9) years] admitted to Hebei General Hospital who met the inclusion criteria were enrolled in this prospective cohort study. According to the principle of wound treatment and the characteristics and needs of wound in different periods, individualized intervention measures were formulated for patients and appropriate dressings were selected. At the time of admission and on 7, 14, 21, 28 days of treatment, the healing of pressure ulcer wounds was evaluated by Pressure Ulcer Healing Scale. Afterwards, the wound exudate was collected at each time point to detect the expression levels of MMP-9 and TIMP-1 protein by enzyme-linked immunosorbent assay, and the MMP-9/TIMP-1 ratio was calculated. Data were processed with analysis of variance for repeated measurements of single group and linear trend test.@*Results@#(1) There were significantly statistical differences in wound healing scores of patients with stages Ⅲ and Ⅳ pressure ulcers among the time of admission and on 7, 14, 21, 28 days of treatment within each stage (F=145.382, 153.234, P<0.01), and they all showed a gradually decreasing trend (F=170.466, 284.585, P<0.01). (2) At the time of admission and on 7, 14, 21, 28 days of treatment, the expression levels of MMP-9 protein in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers were (171±104), (138±88), (110±70), (85±55), (62±41) ng/L and (193±107), (173±104), (139±83), (114±70), (89±56) ng/L, respectively. There were significantly statistical differences within each stage (F=58.007, 111.680, P<0.01), and they all showed a gradually decreasing trend (F=62.901, 134.628, P<0.01). At the time of admission and on 7, 14, 21, 28 days of treatment, the expression levels of TIMP-1 protein in wound exudates of patients with stages Ⅲ and Ⅳ pressure ulcers were (6.2±3.9), (5.6±3.4), (5.1±3.1), (4.4±2.5), (3.8±2.3) ng/L and (4.8±2.5), (4.7±2.6), (4.4±2.6), (4.6±2.7), (4.1±2.4) ng/L, respectively. There were significantly statistical differences within each stage (F=25.479, 7.778, P<0.01), and there was a gradually decreasing trend in stage Ⅲ (F=62.901, P<0.01) and a decreasing trend in stage Ⅳ (F=134.628, P<0.01). At the time of admission, the expression levels of MMP-9 and TIMP-1 in wound exudates of patients with stage Ⅲ pressure ulcers were similar to those of patients with stage Ⅳ pressure ulcers (t=-1.03, 1.47, P>0.05). (3) At the time of admission and on 7, 14, 21, 28 days of treatment, the MMP-9/TIMP-1 ratios in the wound exudates of patients with pressure ulcers of stages Ⅲ and Ⅳ were 30±13, 25±9, 22±9, 20±8, 17±6 and 43±19, 37±13, 32±10, 26±9, 22±9, respectively. There were significantly statistical differences within each stage (F=37.173, 97.191, P<0.01), and they all showed a gradually decreasing trend (F=54.183, 130.088, P<0.01). At the time of admission, the MMP-9/TIMP-1 ratio in wound exudates of patients with stage Ⅳ pressure ulcers was significantly higher than that of patients with stage Ⅲ pressure ulcers (t=-3.42, P<0.01).@*Conclusions@#During the wound healing process of patients with stages Ⅲ and Ⅳ pressure ulcers, the expression levels of MMP-9 and TIMP-1 protein and the MMP-9/TIMP-1 ratio in wound exudates show a decreasing trend. The stage of wound healing can be predicted according to the expression level of MMP-9 protein and the MMP-9/TIMP-1 ratio.
ABSTRACT
An analytical method was developed for the simultaneous extraction and determination of three quaternary ammonium compouds ( QACs) in soil samples using ultrasonic extraction and gas chromatography-mass spectrometry( GC-MS) . The qualitative and quantitative analysis of the three analytes dodecyltrimethyl ammonium chloride ( DTAC) , cetyltrimethyl ammonium bromide ( CTAB) and didodecyldimethyl ammonium chloride ( DDAC) were conducted by application of EI mass spectra and selected ion monioring ( SIM ) . Characteristic ions of the QACs were m/z 58 ( DTAC and CTAB) and m/z 212 ( DDAC) . To achieve optimum extraction efficiency, several impact factors including types of extractants, pH of extraction, concentration of linear alkylbenzene sulfonates ( LAS) , extraction times and content of purification column were investigated. Methanol with pH 3. 5 and 40 μg/L LAS solution were selected as extractant. Soil sample was extracted by treated methanol each 10 mL for 20 min every time. Extract of the soil sample was purified by neutral alumina column with 4 cm in length and 1cm in diameter, and then was determineted by GC-MS. Good linear relationships of all the three QACs were obtained in the range of 0. 02-2. 0 mg/L. The limits of determination (LOD, S/N=3) was 1. 2-4. 5 μg/kg. The method was used to analyse real soil samples ( paddy soil, lateritic red soil, and ore tailings) collected from a mining district in south China. Results of determination exhibited the concerntrations of the three analytes in real soil samples ranged from 0 . 24 mg/kg to 0. 41 mg/kg, and their recoveries ranged from 76% to 113% with relative standard deviations ( RSD) of 1. 1%-12. 9% in three different spiked concentrations of 0. 2, 0. 5 and 1. 0 mg/kg.