Postoperative recovery of patients with differential requirements for sevoflurane after abdominal surgery: A prospective observational clinical study.

ABSTRACT: An association between animals and volatile anaesthetic requirements has been shown; however, evidence related to the postoperative outcome of human patients is lacking. Our aim was to investigate whether there is a difference in the requirement for sevoflurane among people undergoing gastrointestinal surgery.We observed 390 adult patients who underwent gastrointestinal surgery with an American Society of Anesthesiologists physical status of I or II with an expected surgery duration of > 2 hours. We used the bispectral index (BIS) to guide the regulation of end-tidal sevoflurane concentration (ETsevo). The mean ETsevo from 20 minutes after endotracheal intubation to 2 hours after the start of surgery was calculated for all patients. Differential sevoflurane requirements were identified according to ETsevo. The BIS, ETsevo, heart rate, mean arterial pressure, dose of sufentanil and cisatracurium, tracheal extubation time, incidence of intraoperative awareness, and incidence of postoperative nausea and vomiting were compared between patients with a low requirement for sevoflurane (group L) and patients with a high requirement for sevoflurane (group H).The mean ETsevo of the 390 patients was 1.55% ±â€Š0.26%. Based on our definition, patients with an ETsevo of < 1.29% were allocated to the low requirement group (group L; n = 69), while patients with an ETsevo of > 1.81% were allocated to the high requirement group (group H; n = 78). The ETsevo of group L was significantly lower than the ETsevo of group H (1.29% ±â€Š0.014% vs 1.82% ±â€Š0.017%, P < .001). There was no significant difference in the ETsevo, BIS, heart rate, mean arterial pressure, dose of sufentanil and cisatracurium, tracheal extubation time, incidence of intraoperative awareness, and incidence of postoperative nausea and vomiting. The tracheal extubation time in the L group was significantly shorter than that in the H group. No intraoperative awareness occurred.There was a significant difference in the requirement for sevoflurane in adult patients. The tracheal extubation time in group L was significantly shorter than that in group H.

[Inhibitory effect and significance of rapamycin on the mammalian target of rapamycin signaling pathway in osteosarcoma stem cells and osteosarcoma cells].

OBJECTIVE: To observe the effect of rapamycin on the MG-63 osteosarcoma cells (OC), osteosarcoma stem cells (OSC) and on mTOR signaling pathway, and explore the feasibility of rapamycin as a novel therapeutic measure in osteosarcoma chemotherapy regimens. METHODS: OC and OSC were cultured in vitro. Immunofluorescence assay was used to detect the expression of Nanog and Oct4 in OC and OSC. OC and OSC were treated with rapamycin in concentrations of 0, 20, 50 and 100 nmol/L. Semi-quantitative PCR and RT-PCR were used to detect the mTOR mRNA and CCK-8 assay was used to detect cell proliferation, and the cell morphology was observed under an inverted microscope. RESULTS: The cores of MG-63 cellular spheres exhibited embryonic stem cell characteristics such as Nanog and Oct4 expession. The mTOR pathway was activated in the OSC and the expression of mTOR mRNA was higher in OSC (0.761 ± 0.080) than that in OS (0.406 ± 0.090, P < 0.05) by semi-quantitative PCR. RT-PCR showed that the expression of mTOR mRNA was lower in OSCs treated with 100 nmol/L rapamycin (0.961 ± 0.060) than that with 0 nmol/L rapamycin (1.654 ± 0.246, P < 0.05). Cell counting kit-8 (CCK-8) assay showed that the proliferation of OC treated with 20, 50 and 100 nmol/L rapamycin was significantly inhibited, compared with that with 0 nmol/L rapamycin (P < 0.05). Compared with 0 nmol/L rapamycin, the proliferation of OSC treated with 20 and 50 nmol/L rapamycin was not significantly inhibited (P > 0.05), but that with 100 nmol/L rapamycin was significantly inhibited (P < 0.05). The invert microscopic observation revealed that rapamycin inhibited the formation of OSC spheres. CONCLUSIONS: Rapamycin can effectively inhibit cell proliferation and the ability of sphere formation of OSCs. It will provide a basis for a novel therapeutic approach in osteosarcoma chemotherapy regimens.

[In vitro and in vivo study of chondrogenesis on the hybrid scaffold from fibrin modified PLGA and adipose-derived stem cells].

AIM: To investigated the effect of the presence of fibrin in the PLGA scaffold on the differentiation of adipose-derived stem cell (ASCs) into chondrocytes in the chondrogenic media. METHODS: ASCs were prepared by colagenase I digestion of fat from rabbits. The PLGA scaffolds were prepared by LDM technology. The hybrid scaffold was fabricated by a freeze-drying method. Isolated ASCs were cultured in the PLGA without and with fibrin up to 14 days in specific chondrogenic medium. The surface property of the scaffold was observed by SEM. Cell attachment was evaluated, and glycoaminoglycans (GAGs) content was tested by biochemical method. RESULT: When ASCs were seeded within fibrin modified PLGA scaffold in vitro, enhanced cellular attachment and differentiation were observed compared to unmodified PLGA scaffold. The study from articular cartilage defect repaired showed that the group from the autologous ASCs seeded on fibrin-PLGA scaffold had better chondrocyte morphology, tissue integration, continuous subchondral bone, and much thicker newly formed cartilage layer as compared with other groups. CONCLUSION: Such modification of PLGA may ultimately enhance the efficacy of tissue engineered scaffolds for cartilage tissue engineering using ASCs.

Impact of leg lengthening on viscoelastic properties of the deep fascia.

BACKGROUND: Despite the morphological alterations of the deep fascia subjected to leg lengthening have been investigated in cellular and extracellular aspects, the impact of leg lengthening on viscoelastic properties of the deep fascia remains largely unknown. This study aimed to address the changes of viscoelastic properties of the deep fascia during leg lengthening using uniaxial tensile test. METHODS: Animal model of leg lengthening was established in New Zealand white rabbits. Distraction was initiated at a rate of 1 mm/day and 2 mm/day in two steps, and preceded until increases of 10% and 20% in the initial length of tibia had been achieved. The deep fascia specimens of 30 mmx10 mm were clamped with the Instron 1122 tensile tester at room temperature with a constant tensile rate of 5 mm/min. After 5 load-download tensile tests had been performed, the specimens were elongated until rupture. The load-displacement curves were automatically generated. RESULTS: The normal deep fascia showed typical viscoelastic rule of collagenous tissues. Each experimental group of the deep fascia after leg lengthening kept the properties. The curves of the deep fascia at a rate of 1 mm/day with 20% increase in tibia length were the closest to those of normal deep fascia. The ultimate tension strength and the strain at rupture on average of normal deep fascia were 2.69 N (8.97 mN/mm2) and 14.11%, respectively. The increases in ultimate tension strength and strain at rupture of the deep fascia after leg lengthening were statistically significant. CONCLUSION: The deep fascia subjected to leg lengthening exhibits viscoelastic properties as collagenous tissues without lengthening other than increased strain and strength. Notwithstanding different lengthening schemes result in varied viscoelastic properties changes, the most comparable viscoelastic properties to be demonstrated are under the scheme of a distraction rate of 1 mm/day and 20% increase in tibia length.

Treatment of nonunions of humeral fractures with interlocking intramedullary nailing.

OBJECTIVE: To introduce the experience of treating nonunions of humeral fractures with interlocking intramedullary nailing. METHODS: Twelve patients with humeral nonunions were treated with interlocking intramedullary nailing. The time interval between trauma and surgery was 10.5 months on average. Open reduction with anterograde approach was performed. Axial compression was specially applied to the fracture site with humeral nail holder after insertion of distal locked screws. Iliac bone grafting was added. RESULTS: The average follow-up period was 21 months (ranging 9-51 months). All patients achieved osseous union 5.8 months after treatment on average. Eleven patients had good functions of the shoulder joints and the upper extremities. No patient experienced any permanent neurological deficit. Refracture of the original ununited region occurred in one patient after removal of the internal fixator one year later, but union was achieved after closed re-intramedullary nailing fixation. CONCLUSION: Humeral interlocking intramedullary nailing is an effective alternative treatment for humeral nonunion.

The effect on the extracellular matrix of the deep fascia in response to leg lengthening.

BACKGROUND: Whereas the alterations of diverse tissues in cellular and molecular levels have been investigated during leg lengthening via microscopy and biochemical studies, little is known about the response of deep fascia. This study aims to investigate the changes of the extracellular matrix in deep fascia in response to leg lengthening. METHODS: Animal model of leg lengthening was established in New Zealand white rabbits. Distraction was initiated at a rate of 1 mm/day and 2 mm/day in two steps, and preceded until increases of 10% and 20% in the initial length of tibia had been achieved. Alcian blue stain and picrosirius-polarization method were used for the study of the extracellular matrix of deep fascia samples. Leica DM LA image analysis system was used to investigate the quantitative changes of collagen type I and III. RESULTS: Alcian blue stain showed that glycosaminoglycans of fascia of each group were composed of chondroitin sulphate and heparin sulphate, but not of keratan sulphate. Under the polarization microscopy, the fascia consisted mainly of collagen type I. After leg lengthening, the percentage of collagen type III increased. The most similar collagen composition of the fascia to that of the normal fascia was detected at a 20% increase in tibia length achieved via a distraction rate of 1 mm/d. CONCLUSION: The changes in collagen distribution and composition occur in deep fascia during leg lengthening. Although different lengthening schemes resulted in varied matrix changes, the most comparable collagen composition to be demonstrated under the scheme of a distraction rate of 1 mm/day and 20% increase in tibia length. Efficient fascia regeneration is initiated only in certain combinations of the leg load parameters including appropriate intensity and duration time, e.g., either low density distraction that persist a relatively short time or high distraction rates.

Treatment of ipsilateral femoral neck and shaft fractures.

OBJECTIVE: To investigate the clinical characteristics, treatment options and causes of misdiagnosis of ipsilateral femoral neck and shaft fractures. METHODS: Among 20 patients with ipsilateral femoral neck and shaft fractures, 19 were treated operatively and 1 was treated conservatively. Sixteen cases of femoral shaft fractures were treated by open reduction and internal fixation with compressive plate, and 2 cases were treated with interlocking intramedullary nailing. Eighteen femoral neck fractures were treated with cannulated screws. Another patient was treated with proximal femoral nail to fix both the neck and shaft. Delayed diagnosis for femoral neck fractures occurred in 2 cases preoperatively. RESULTS: A total of 19 patients were followed up. The follow up period ranged from 5 to 48 months with an average of 15 months. All the fractures were healed. CONCLUSION: For case of femoral shaft fracture caused by high energy injury, an AP pelvic film should be routinely taken. Once the femoral neck fracture is recognized, operative reduction and fixation should be performed in time. Femoral neck and shaft fractures should be fixed separately.

Collagen I gel can facilitate homogenous bone formation of adipose-derived stem cells in PLGA-beta-TCP scaffold.

Cell-based tissue engineering is thought to be a new therapy for treatment of bone defects and nonunions after trauma and tumor resection. In this study, we explore the in vitro and in vivo osteogenesis of a novel biomimetic construct fabricated by using collagen I gel to suspend rabbit adipose-derived stem cells (rASCs) into a porous poly(lactic-co-glycolic)acid-beta-tricalcium phosphate (PLGA-beta-TCP) scaffold (rASCs-COL/PLGA-beta-TCP). In vitro and in vivo studies of the rASCs-COL/PLGA-beta-TCP composite (group A) were carried out compared with the single combination of rASCs and PLGA-beta-TCP (rASCs/PLGA-beta-TCP; group B), the combination of acellular collagen I gel and PLGA-beta-TCP (COL/PLGA-beta-TCP; group C), and the PLGA-beta-TCP scaffold (group D). Composites of different groups were cultured in vitro for 2 weeks in osteogenic medium and then implanted into the autologous muscular intervals for 8 weeks. After 2 weeks of in vitro culture, alkaline phosphatase activity and extracellular matrix mineralization in group A were significantly higher than in group B (p < 0.01, n = 4). In vivo osteogenesis was evaluated by radiographic and histological analyses. The calcification level was radiographically evident in group A, whereas no apparent calcification was observed in groups B, C and D (n = 4). In group A, woven bone with a trabecular structure was formed, while in group B, only osteoid tissue was observed. Meanwhile, the bone-forming area in group A was significantly higher than in group B (p < 0.01, n = 4). No bone formation was observed in groups C or D (n = 4). In conclusion, by using collagen I gel to suspend rASCs into porous PLGA-beta-TCP scaffold, osteogenic differentiation of rASCs can be improved and homogeneous bone tissue can be successfully formed in vivo.

The matrix metalloproteinases as pharmacological target in osteoarthritis: statins may be of therapeutic benefit.

Osteoarthritis (OA) is a common joint disease; however, current pharmacologic agents for OA are only symptomatic and they can not prevent the disease progression. Matrix metalloproteinases (MMPs) produced by chondrocytes play an important role in the development of cartilage destruction in OA, and agents that can target against MMPs activity may be of therapeutical value. There were reports that statins can inhibit the secretion of MMPs in vitro and in vivo, which were believed to account for the plaque stabilizing effects of statins in the treatment of atherosclerosis. We based our hypothesis on that atherosclerosis possesses some aspects that are similar to that of osteoarthritis, such as inflammation and matrix degradation. Since statins have displayed great benefits in modifying the progression of atherosclerosis via anti-inflammatory and matrix-stabilizing mechanisms, it is conceivable that statins may also prevent the disease progression of osteoarthritis. Further work are needed to verify if statins can protect cartilage from destruction through inhibition of MMP secretion by chondrocytes, and their potential to be used as therapeutic agents in OA should be investigated.