Objective To compare the effect and coverage of bacteriostasis of chitosan and sodium hyaluronate. Methods Each of the five bacteria, Proteus mirabilis, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus, was cultivated for 33 tubes of broth culture. Leaving three tubes each group as control group, ploidy diluted concentration of high relative molecular weight chitosan, low relative molecular weight chitosan and sodium hyaluronate were added respectively in the broth culture. All the tubes were cultivated for 18 hours at 37 ℃ with homeothermia. Then the growth of bacteria was observed. ResultsThe minimal inhibitory concentrations (MIC) of high relative molecular weight chitosan were : Proteus mirabilis 0.031%, Escherichia coli 0.063%, Candida albicans 0.063%, Pseudomonas aerugionosa 0.063%, Staphylococcus aureus 0.063%; and the MIC of low relative molecular weight chitosan were: Proteus mirabilis 0.125%, Escherichia coli 0.025%, Candida albicans 0.25%, Pseudomonas aeruginosa 0.25%, Staphylococcus aureus 0.125%; bacteria grew well in each tube of sodium hyaluronate group and control group. Conclusion The above results show that sodium hyaluronate has no bacteriostasis, while chitosan has bacteriostasison broad spectrum and high relative molecular weight chitosan has ber effect.
Yushu earthquake bettered a record all round in ability and speed about emergency command, provisioning, medical rescue, epidemic prevention, rebuilding and policy ensuring. The article compared the achievements in medical rescue of Yushu earthquake and Wenchuan earthquake from Ministry of Health and the hospitals who took part in medical rescue within 3 months after Yushu earthquake in order to summarize the experience, form the standard and provide decision-making references.
Objective To investigate the therapeutic effects of anterior approach set (AAS) versus posterior approach set (PAS) in treating multilevel cervical disc herniation of three or four segments. Methods Fifty-six cases of multilevel cervical disc herniation were retrospectively studied. Thirty-seven casesunderwent anterior approach, and discectomy, selectively partial corpectomy with bone grafting and plate fixing was performed (AAS group); 19 cases underwent posterior approach, and laminectomy with lateral cervical mass plate screw fixing was performed (PAS group).Results The followup periods were 6 months to 4 years and 5 months, averaging 2 years and 10 months in AAS group and 1 year and 5 months to 5 years and 1 month, averaging 3 years and 8 months in PAS group. JOA functional assessment and sagittal diameter of dural sac were not-statistically significant between two groups before operation (Pgt;0.05) andwere significantly larger in AAS group than in PAS group after operation (Plt;0.01). The improvement rate of AAS was significant higher than that of PAS (Plt;0.01). The number of complication in AAS were slight more than that in PAS.Conclusion AAS is obviously better than PAS in the therapeutic effects. The operation of anterior decompression with bone grafting and plate fixing is an indication of multilevel cervical disc herniation of three or four segments.
Objective To compare the effects of flap delay and vascular endothelial growth factor (VEGF) on the viability of the rat dorsal flap. Methods Thirty rats were divided into 3 groups: saline group, flap delay group and VEGF group. The rats in flap delay group underwent flap delay by keeping bipedicle untouched, and the cranial pedicle was cut 7 days later. The rats in VEGF group were given VEGF solution locally when the flaps were elevated in the operation. The ratsin saline group were given saline solution in the same way. Five days after thesingle pedicle flaps were performed, the flap survival rate was measured. Theflap tissues were collected to measure and analyze the microvascular density, diameter and sectional area by immunochemical method. Results The flap survival rate of flap delay group was similar to that of VEGF group andthere is no statistically significant difference(Pgt;0.05). The vascular diameter of flap delay group was much larger than that of saline group and VEGF group, showing statistically significant difference (Plt;0.05). The vascular density of VEGF group was much higher than that of saline group and flap delay group, showing statistically significant difference (Plt;0.05). The vascular sectional area of flap delay group was similar to that of VEGF group(Pgt;0.05). Conclusion The change in the flap after flap delayis manifested as obvious dilatation of microvessels, while the change in the flap after the injection of VEGF is manifested as obvious vascular proliferation. Both flap delay and VEGF can increase the vascular sectional area and the viability of the flap, but the mechanism is different.
Objective To study the influence of the pedicle length on the perforator flaps in hemodynamics. Methods Four mature swine (2 males, 2 females; weight, 23.0±2.0 kg) were applied to the experiment.Two transverse abdominal skin flaps, based on the superior epigastric pedicle orits rectus abdominal muscle perforators, were designed; each swine was used as its own control. At 2 hours and 1, 2, 3 weeks postoperatively, the skin paddle perfusion and the blood stream velocity in the superior epigastric artery were measured by the Laser Doppler Flowmeter and the Color Doppler Ultrasound, respectively. Flap survival percentages were calculated by the grid method at 1 week postoperatively. The swine were euthanatized, and they underwent angiography at 3 weeks postoperatively. Results At 2 hours and 1 week after operation, edema of the perforator flaps with the superior epigastric pedicle was more severe than that of the skin flaps with the rectus abdominal muscle perforator, and the skin perfusion had a statistical difference between the two kindsof flaps (Plt;0.05). The skin paddle viability and the skin perfusion had nostatistical difference after the first week postoperatively (Pgt;0.05). At 2hours and 1 week after operation, the blood stream velocity in the superior epigastric artery in the perforator flap with the superior abdominal artery pediclewas reduced, and there was a statistical difference between the two kinds of flaps (Plt;0.05); however, the velocity was almost the same after the first week postoperatively. Conclusion The excessively long pedicle of the perforator skin flap may have an unfavorable influence on the flap perfusion,especially during the first week after operation, because of the vascular compromise during the dissection of the long pedicle. The blood vessel anastomosis atthis level of the blood vessels may have no relationship with the perforator flap in hemodynamics. This study can also indicate that the ligation of the branches in the recipient vessels cannot make the perforator flaps overperfused.
Rolling enrollment is a common method for participant recruitment in medical practice. In the longitudinal data, where researchers are often interested in outcomes occurring after a certain period of treatment, the definition of causal effects differs from that in the cross-sectional data. It poses new challenges for the application of matching methods in the longitudinal studies. Longitudinal matching is an extension of matching methods in longitudinal studies involving static interventions such as rolling enrollment. Currently, longitudinal matching methods are widely applied in the comparative effectiveness research. This article elucidates the fundamental principles, applicable conditions, code implementation, and application instances of four longitudinal matching methods through theoretical discussions and empirical illustrations. It provides methodological references for estimating causal effects in longitudinal data analysis.
Objective To compare the outcomes of two operative methods, the anterior decompression in subsection and the anterior decompression in one section, which were used to treat multilevel cervical spondylotic myelopathy (CSM). Methods Data of multilevel CSM undergoing the anterior decompression in subsection (33 cases, the subsection group) and the anterior decompression in one section (19 cases, the one section group) from July 1999 to January 2004 were retrospectively analyzed. The- incidence of perioperative complications and the rate of fusion were evaluated by the postoperative X-ray and MRI examinations, and improvement of the neurological function was evaluated by the JOA score.Results The incidence of perioperative complications was 36.8%in the one section group, mainly including immigration of the plate and grafts,which was settled by the revision surgery; while the incidence of perioperative compilcations was 12.1% in the subsection group, mainly including the immigration of the titanium mesh. There was a significant difference between the two groups (Plt;0.05). 84.2％ of the patients in the one section group and 81.8％ of the patients in the subsection group developed bony fusion by the end of the follow-up (9-31 mon, averaged 112 mon), and there was no significant differencebetween the two groups (Pgt;0.05). According to the JOA score, the ratio of the improvement in the neurological function was 70.4% in the subsection group and 64.4% in the one section group. There was no significant difference between the two groups (Pgt;0.05). Conclusion The anterior decompression in subsection is more rational for the surgical treatment on the multilevel CSM than the anterior decompression in one section. It can provide an equal decompressive effect but a more stable local mechanical environment right after the surgery and can maintain it well, which is critical for the bony fusion.
Objective To compare the clinical effect of reamed and nonreamed intramedullary interlocking nails on treating open tibial fractures. Methods From February 2002 to February 2004, 92 cases of open tibial fractures (86 patients) were treated with intramedullary interlocking nails. Of the 86 patients, 65 were male and 21 were female. Their age ranged from 18 to 68 years (36.5 on average). Of the 92 cases, 54 were in the reamed group and 38 in the nonreamed group. Patients moved with the support of crutch after their wounds were healed. Results All patients were followed up regularly for 6 to 24months. Infection rate in the reamed group and nonreamed group was 20.3% and 5.3% respectively, and there was significant difference between them (Ｐlt;0.05). The averagehealing time of the fractures was 22.5 weeks in reamed group and 19 weeks in nonreamed group, and there was no significant difference between them (Ｐ＞0.05). Delayed unions occurred in 8 cases and 3 cases in reamed group and nonreamed group respectively. Conclusion Compared with reamed group, nonreamed intramedullary interlocking nails have lowerinfection rate and fewer delayed unions and ununions.
Objective To compare the cl inical effects of indirect decompression versus open decompression to vertebral canal in treatment of thoracolumbar burst fractures without neurologic deficit. Methods From April 2004 to June 2008, 52 cases of thoracolumbar burst fracture without neurologic deficit underwent posterior exposition, reduction and fixation with Atlas Fixator (AF) instrumentation. There were 34 males and 18 females with an average age of 43.1 years (range, 31-63 years). The affectd locations were T11 in 5 cases, T12 in 24 cases, L1 in 16 cases, and L2 in 7 cases. The time from injury to operation was 3-8 days (4.4 days on average). All cases were devided into indirect decompression group (group A) and open decompression group (group B). There were no statistically significant differences (P gt; 0.05) in sex, age, affect site, and disease course between two groups. The operative time, blood loss were recoded. Preoperatively, immediately postoperstively and at last follow-up, the height of the fracture vertebra and the Cobb angle were obtained from X-ray pictures and were statistically analysed. Radiographic parameters on computed tomography (CT) pictures were used to get the encroachment rate of vertebral canal. Results The operative time was (87.3 ± 7.9) minutes and (125.3 ± 13.6) minutes, and the blood loss was (273.7 ± 23.4) mL and (512.6 ± 37.7) mL in groups A and B, respectively; showing statistically significant differences (P lt; 0.05). The average follow-up time was 17.4 months (range, 11-31 months) in group A and 19.9 months (range, 12-33 months) in group B. All wounds achieved primary heal ing postoperatively without deaths and spinal cord injuries. Postoperative compl ications in group B included 3 cases of screws loosening, 1 case of screw breakage, and 3 cases of low back pain, and were given symptomatic management. There were no statistically significant differences (P gt; 0.05) in the height of the fracture vertebra, the Cobb angle andthe encroachment rate of vertebral canal preoperatively or postoperstively between two groups. There were statistically significant differences (P lt; 0.05) in the above three parameters between preoperation and postoperation in two groups, but there were no statistically significant differences (P gt; 0.05) in the spinal correction between two groups. The losing-rate of spinal correction of the height of the fracture vertebra and the Cobb angle of group A was lower than group B, showing statistically significant differences (P lt; 0.05). Conclusion The short-term results of two decompression styles in treatment of thoracolumbar burst fractures without neurologic deficit were satisfactory, but indirect decompression has more merits than open decompression: shorter operative time, less blood loss, lower losing-rate of spinal correction, and better stabil ization of vertebral column.
Objective To investigate the clinical effect of vascularized and non-vascularized full-length phrenic nerve transfer on treating brachial plexus injury. Methods From August 1999 to March 2000, full-length phrenic nerve transfer to musculocutaneous nerve was conducted with the technique of Video-AssistedThoracic-Surgery in 15 patients（M 13, F 2）that all suffered from avulsion. Threekinds of procedures were carried out. The first was retaining initial point of phrenic nerve and dissecting full-length distal nerve (group A). The second waskeeping cervical segment and isolating thoracic segment of phrenic nerve (group B). The last was vascularized phrenic nerve transfer (group C). All these phrenic nerves were sutured to musculocutaneous nerves. The results of electrophysiology and function of biceps brachii muscle were compared. Results The lengthof the dissecting full-length distal nerves in group A, group B and group C compared with that of conventional operation increased by 17.8±1.1 cm, 10.2±1.0 cm and 8.8±0.5 cm respectively. There was significant difference when group A was compared with group B and group C, when group B was compared with group C. All three procedures had no significant difference and led to the same function recovery of biceps brachii muscle to grade Ⅲ about 6 months later. Conclusion There is no difference in treating effect between vascularized and non-vascularized full-length phrenic nerve transfer, when the recipientbed has normal vascularity.