Aim To study the mechanism of 8-isopro-pylaminomethyl hesperitin ( IPHP ) intestinal absorp-tion using Caco-2 cell lines. Methods Using Caco-2 cell lines as an intestinal epithelial cell model, the effects of drug concentration, temperature, pH, P-gly-coprotein ( P-gp) inhibitor verapamil and multidrug re-sistance protein 2 ( MRP2 ) inhibitors MK-571 or pro-benecid on IPHP transport across Caco-2 cell lines were all investigated. Results The transportation of IPHP was related to drug concentration. The Papp ( AP-BL) ( × 10 -5) was (2. 21 ± 0. 200) cm·s-1,(3. 56 ± 0. 306) cm·s-1,(3. 81 ± 0. 179) cm·s-1,(4. 23 ± 0. 229 ) cm · s-1 , ( 4. 17 ± 0. 262 ) cm · s-1 , re-spectively, and Papp(BL-AP) ( × 10 -5) was (3. 57 ±0. 209) cm·s-1,(4. 51 ± 0. 113) cm·s-1,(4. 97 ± 0. 229) cm·s-1,(5. 24 ± 0. 550) cm·s-1,(5. 07 ± 0. 557) cm·s-1,respectively. Efflux rate was 1. 61, 1. 26,1. 3,1. 23,1. 21,respectively. Temperature and pH both influenced the transport, While the P-gp in-hibitor verapamil had no effect on the transport of IPHP. MRP2 inhibitors MK-571 or probenecid led to an apparent decrease in the efflux of IPHP. Conclu-sion The results suggest that the transport of IPHP is mainly passive diffusion, and MRP2 but not P-gp may be involved in the transport of IPHP.

Objective:To investigate the effect of tourniquet-reperfusion augmented infrared thermography(TRAIRT) on locating the dominant perforator to assist design of free medial sural artery perforator flap.Methods:The data of patients with skin soft tissue defect of upper limb repaired by free medial sural artery perforator flap in Department of Hand Surgery, Ningbo Sixth Hospital from May 2019 to January 2022 were retrospectively analyzed. Color Doppler ultrasonography (CDU) and TRAIRT were used to locate the dominant perforator auxiliary flap design before surgery and after anesthesia. In the TRAIRT video, the hot spot with "early emergence, high brightness and fast expansion" was selected as the advantageous perforator. During the operation, the flap was elevated and transferred to the affected area to cover the defect wound according to the designed mark points, and fixed by the absorbable sutures with an interrupted suturing method, then end-to-end vascular anastomosis was performed successively. The donor area was sutured directly or sutured with full thickness skin grafts depending on the area of the wound. The donor and recipient areas of the flap were observed and the patients’ satisfaction was recorded. The gold standard was the actual location of the perforating vessel found during the operation. Compared with the gold standard, the location of the perforating vessel explored by TRAIRT and CDU was considered to be accurate (positive) if the distance was less than 10 mm. The sensitivity (accurate number of perforators/actual number of perforators during operation ×100%) and positive predictive value (accurate number of perforators/total number of perforators×100%) of the two methods were calculated, expressed as %, and the sensitivity of the two methods was compared by paired χ2 test. Kappa coefficient was used to analyze the consistency of the two methods to detect perforating vessels. The perforator detection time of TRAIRT and CDU were recorded, expressed as Mean±SD, and statistically analyzed by paired sample t-test. Results:A total of 23 patients were included, consisting of 14 males and 9 females, agd 21-70 years old, average age of 43 years old. The wounds were on forearm in 5 cases, wrist in 2 cases, and hand in 16 cases. The wound area was 4.5 cm × 5.5 cm-6.5 cm × 12.0 cm. Intraoperative flap incision area was 5.0 cm × 6.0cm-7.0 cm × 13.0 cm. After operation, 22 cases of flaps survived, 1 case had superficial necrosis at the distal end, which healed after repeated dressing change. The donor area of flaps healed well, with primary suture in 20 cases and full thickness skin grafting in 3 cases. Postoperative follow-up was 5-16 months (mean 8.4 months). The flaps had no bulge, swelling and abrasion. The texture and color were similar to the medial calf skin, and the scars in the donor and recipient areas were not obvious. The patients were satisfied with the recovery. Among the 23 patients, 49 perforators were found by TRAIRT, 50 perforators were found by CDU, and 53 perforators were found intraoperatively. The sensitivity of TRAIRT and CDU was 88.7% (47/53) and 90.6% (48/53), with no significant differences ( P>0.05), and the positive prediction value was 95.9% (47/49) and 96.0% (48/50) respectively. The Kappa coefficient was 0.89, indicating a good consistency between the two methods. The time required for TRAIRT to detect perforators was significantly shorter than that of CDU, with statistical significance [(6.52±2.02) min vs. (17.87±2.49) min, P<0.01]. Conclusion:TRAIRT has a good consistency with CDU in detection of medial sural artery perforator. The application of TRAIRT in designing medial sural artery perforator flap for wound repair is good, and it has advantages of short time taking, simple operation, economy and non-invasiveness.

Objective:To investigate the effect of tourniquet-reperfusion augmented infrared thermography(TRAIRT) on locating the dominant perforator to assist design of free medial sural artery perforator flap.Methods:The data of patients with skin soft tissue defect of upper limb repaired by free medial sural artery perforator flap in Department of Hand Surgery, Ningbo Sixth Hospital from May 2019 to January 2022 were retrospectively analyzed. Color Doppler ultrasonography (CDU) and TRAIRT were used to locate the dominant perforator auxiliary flap design before surgery and after anesthesia. In the TRAIRT video, the hot spot with "early emergence, high brightness and fast expansion" was selected as the advantageous perforator. During the operation, the flap was elevated and transferred to the affected area to cover the defect wound according to the designed mark points, and fixed by the absorbable sutures with an interrupted suturing method, then end-to-end vascular anastomosis was performed successively. The donor area was sutured directly or sutured with full thickness skin grafts depending on the area of the wound. The donor and recipient areas of the flap were observed and the patients’ satisfaction was recorded. The gold standard was the actual location of the perforating vessel found during the operation. Compared with the gold standard, the location of the perforating vessel explored by TRAIRT and CDU was considered to be accurate (positive) if the distance was less than 10 mm. The sensitivity (accurate number of perforators/actual number of perforators during operation ×100%) and positive predictive value (accurate number of perforators/total number of perforators×100%) of the two methods were calculated, expressed as %, and the sensitivity of the two methods was compared by paired χ2 test. Kappa coefficient was used to analyze the consistency of the two methods to detect perforating vessels. The perforator detection time of TRAIRT and CDU were recorded, expressed as Mean±SD, and statistically analyzed by paired sample t-test. Results:A total of 23 patients were included, consisting of 14 males and 9 females, agd 21-70 years old, average age of 43 years old. The wounds were on forearm in 5 cases, wrist in 2 cases, and hand in 16 cases. The wound area was 4.5 cm × 5.5 cm-6.5 cm × 12.0 cm. Intraoperative flap incision area was 5.0 cm × 6.0cm-7.0 cm × 13.0 cm. After operation, 22 cases of flaps survived, 1 case had superficial necrosis at the distal end, which healed after repeated dressing change. The donor area of flaps healed well, with primary suture in 20 cases and full thickness skin grafting in 3 cases. Postoperative follow-up was 5-16 months (mean 8.4 months). The flaps had no bulge, swelling and abrasion. The texture and color were similar to the medial calf skin, and the scars in the donor and recipient areas were not obvious. The patients were satisfied with the recovery. Among the 23 patients, 49 perforators were found by TRAIRT, 50 perforators were found by CDU, and 53 perforators were found intraoperatively. The sensitivity of TRAIRT and CDU was 88.7% (47/53) and 90.6% (48/53), with no significant differences ( P>0.05), and the positive prediction value was 95.9% (47/49) and 96.0% (48/50) respectively. The Kappa coefficient was 0.89, indicating a good consistency between the two methods. The time required for TRAIRT to detect perforators was significantly shorter than that of CDU, with statistical significance [(6.52±2.02) min vs. (17.87±2.49) min, P<0.01]. Conclusion:TRAIRT has a good consistency with CDU in detection of medial sural artery perforator. The application of TRAIRT in designing medial sural artery perforator flap for wound repair is good, and it has advantages of short time taking, simple operation, economy and non-invasiveness.

Objective : The purpose of this study was to investigate the effect of different exposure sequence and interval on the post-antibiotic effect(PAE) and 24-hour time-kill produced by linezolid and fosfomycin in combination againstStaphylococcus aureus(S.aureus). Methods: PAEs were evaluated by exposingS.aureusto linezolid and fosfomycin individually and simultaneously for 1 h.Further assess of PAEs with the organism exposed first to linezolid for 1 h, followed by a second 1 h fosfomycin exposure at the beginning(Tb),middle(Tm)and end(Te) of the PAE phase induced by linezolid.The next study was similar to the above, but with the sequence of the two antibiotics reversed, i.e.fosfomycin then linezolid.The 24-hour time-kill studies were performed with three exposure regimens: simultaneous exposure of the two antibiotics; first exposure to linezolid for 1 h and then combined with fosfomycin, and first exposure to fosfomycin for 1 h and then combined with linezolid to draw the sterilized curve. Results: Compared with the PAE of individual antibiotics [ linezolid(1.2±0.1) h, fosfomycin(1.6±0.1) h],the PAE produced by simultaneous exposure of the combination(2.9±0.1) h presented additive interaction.However, the PAE of fosfomycin decreased or even disappeared(-0.3 h for Tb, 0 h for Tm and 0.9 h for Te) during the PAE phase of linezolid, and with a stronger antagonism at the beginning.Differently, an additive interaction was observed again when the test organism was exposed to fosfomycin first.In the 24-hour time-kill assays, the antibacterial effect of the first exposure to fosfomycin regimens was significantly stronger(difference of 1 log10)than that of the simultaneous exposure and the first exposure to linezolid, while the latter two were similar. Conclusion The pharmacodynamic behaviour of linezolid combined with fosfomycin againstS.aureuswas influenced by exposure regimen.The first exposure to fosfomycin regimens rather than simultaneous exposure may exert the optimal antibacterial activity.Therefore, the exposure regimen is one of the important factors to be considered for the clinical application of this combination.