Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial.

BACKGROUND: Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade. METHODS: Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 µg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 µg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded. RESULTS: The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007). CONCLUSIONS: Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied. TRIAL REGISTRATION: This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Effect of dorsal nerve fascial island flap on repairing distal soft tissue defects at the proximal segment of the index, middle, ring, and little fingers.

BACKGROUND: To investigate the effect of the dorsal nerve fascial island (DNFI) flap on repairing finger soft tissue defects at the distal segments. METHODS: Fifty patients with distal soft tissue defects at the index, middle, ring, or little fingers were treated with a DNFI flap at the proximal phalanx between February 2008 and May 2018. The nutrient vascular chain around the dorsal branch of the proper palmar digital nerves served as the flap axis. The dorsal branch of the proper palmar digital arteries provided blood supply. The fascia pedicle served as the venous system. All patients were followed for 6 months. RESULTS: All 50 flaps survived. The appearance, color, and texture of the skin returned to normal. The sensory function was partially restored. The two-point discrimination of the finger flap was 7-10 mm. CONCLUSIONS: The DNFI flap at the proximal phalanges of the index, middle, ring, and little fingers is an effective surgical option. The technique has a high flap survival rate and long pedicle, which can repair different parts of the finger. The flap also restores the sensory function of the finger without damaging the main nerves or blood vessels. The flap treatment is an optimal option for finger soft tissue defects at the distal segments.

miR­144 promotes the proliferation and differentiation of bone mesenchymal stem cells by downregulating the expression of SFRP1.

Osteoporosis (OP) seriously affects the health and quality of life of elderly individuals and postmenopausal women, and the need to identify drugs that can prevent or treat OP remains urgent. Recently, several miRNAs have been reported to be involved in the differentiation of mesenchymal stem cells and osteoblasts; however, the role of miRNA (miR)­144 in regulating OP remains to be elucidated. In the present study, the expression levels of miR­144, secreted frizzled­related protein 1 (Sfrp1) and TNF­α in clinical samples were detected by the reverse transcription­quantitative polymerase chain reaction analysis and ELISA, respectively. 5­Ethynyl­2'­deoxyuridine staining, Hoechst 33258 staining, flow cytometry, a clone formation assay and Alizarin red staining were used to assess the effects of miR­144 combined with or without Sfrp1 small interfering RNA on the proliferation, apoptosis and osteoblastic differentiation of primary mesenchymal stem cells isolated from rats. Western blot assays were performed to assess the relevant mechanisms, and a dual luciferase reporter assay was used to detect the interaction between miR­144 and Sfrp1. The results showed that the levels of miR­144, Sfrp1 and TNF­α in clinical serum samples obtained from patients with postmenopausal OP were higher than those in serum samples obtained from postmenopausal women with normal bone density. There was a significant positive correlation between miR­144 and Sfrp1. Functional experiments demonstrated that miR­144 promoted proliferation, inhibited apoptosis and induced the osteoblastic differentiation of bone marrow­derived mesenchymal stem cells by targeting Sfrp1. It was also shown that miR­144 may help regulate OP by activating the Wnt/ß­catenin pathway. These data suggest miR­144 as a novel target for preventing and treating OP.

[Influence of platform switching on crest bone maintenance around implants: a radiographic investigation in dogs].

PURPOSE: To evaluate and compare the dynamic changes in functional loading or non-functional loading with platform-switching (PLS) implants and butt-joint implants,and to refine the factors leading to marginal bone loss around PLS. METHODS: Six adult dogs were selected and numbered randomly.The second,third and fourth premolars in bilateral mandible of each dog were extracted. After 3 months, the implantation operation was carried out. There were 3 kinds of implants, 36 implants in total, which were divided in to 3 groups: Group A,Group G and Group U. In particular order, A, G and U were placed on each side of every dog. Three months later, the 2nd surgery was begun. At the 4th month from the 1st surgery, for each dog, on the right side only, the abutments were installed and impression was taken. Then, after 2 weeks, the dental prostheses were put on. All dogs were executed at the end of the 12th month. X-ray film was taken at the 3rd, 6th, 9th and 12th month and the moment of the 1st surgery (baseline). Measurements were made between the implant shoulder (IS),the most coronal level of bone in contact with implant (CLB), and the level of alveolar bone crest (BC). According to the different groups of implants (A, G, U), all records were analyzed with paired and Wilcoxon's signed rank test using SPSS11.5 software package. RESULTS: The mean IS-CLB and IS-BC values of group A, G were significantly different with those of group U at the 6th, 9th and 12th month, while there was no significant difference between group A and G. No matter they were loading or not, the self-comparison of each kind of implant presented no significant difference. There was no significant difference between every kind of implant on their self-comparison during the first three months; while, the differences were significant during the next 9 months. CONCLUSIONS: The most significant changes in the absorption of marginal bone around two stage submerged implant can be observed after 3 months of implanting. The bone absorption was not related to functional loading or not.