[Clinical study of digital six-axis external fixation frame based on CT data for tibiofibular fractures]

Objective: To investigate the clinical effect of applying the digital six-axis external fixation frame based on CT data in the treatment of tibiofibular fractures. Methods: The clinical data of 43 patients with tibiofibular fractures treated by the self-developed digital six-axis external fixation frame based on CT data at Integrated Orthopedic Department of Traditional Chinese Medicine (TCM) and Western Medicine,HongHui Hospital from January 2018 to January 2021 were retrospective analysis.There were 27 males and 16 females,aged (36.0±9.4) years(range:25 to 50 years).AO classification:15 cases of 42A,11 cases of 42B, and 17 cases of 42C.There were 7 open fractures and Gustilo fracture classification:2 cases of type Ⅰ,4 cases of type Ⅱ,and 1 case of type Ⅲ.The two or three plane rings were connected with six connecting rods to form a complete six-axis external fixation frame,and the distal and proximal fracture blocks were connected to the distal and proximal rings by fixation pins,and the lengths of the six connecting rods needed to be adjusted were calculated by using the supporting software according to the CT data after surgery,and then the lengths of the connecting rods were adjusted one by one to complete the reduction of the fracture. The reduction accuracy of this six-axis external fixation brace was evaluated by measuring postoperative radiographs; postoperative recovery and complications were collected,the time of brace removal was recorded,and the function of the affected limb was evaluated according to the Johner-Wruhs score at the final follow-up. Results: Postoperative radiographs showed that all patients achieved satisfactory reduction with lateral displacement(M(IQR)) of 2.3(2.5) mm (range:0.3 to 7.3 mm),anteroposterior displacement of 2.1 (2.4) mm (range:0.3 to 5.7 mm),anteroposterior angulation of 2.5(2.4)°(range:0 to 5°),internal and external angulation of 2.1(1.5)°(range:0 to 4°), and no significant internal or external rotational deformity was detected on the exterior.On the second postoperative day,all patients were able to walk with partial weight-bearing on crutches. All 43 patients were followed up for more than 6 months,with a follow-up period of (33.3±7.3) weeks (range:24 to 42 weeks).The external fixation frame was removed after the fracture healed.The external frame was removed at 20(3)weeks (range:18 to 25 weeks) postoperatively. Up to the final follow up, no secondary fracture occurred in any of them.The Johner-Wruhs score of the affected limb at the last follow-up was excellent in 39 cases and good in 4 cases. Conclusion: The digital six-axis external fixator based on CT data for tibiofibular fractures has the advantages of precise reduction,firm fixation,simple operation,rapid fracture healing,and minimal trauma, which is a minimally invasive method for treating tibiofibular fractures,especially suitable for patients with poor skin and soft tissue conditions such as open injuries.

The pharmacokinetics of nitazoxanide active metabolite (tizoxanide) in goats and its protein binding ability in vitro

The pharmacokinetics of tizoxanide (T), the active metabolite of nitazoxanide (NTZ), and its protein binding ability in goat plasma and in the solutions of albumin and alpha-1-acid-glycoprotein were investigated. The plasma and protein binding samples were analyzed using a high-performance liquid chromatography (HPLC) assay with UV detection at 360 nm. The plasma concentration of T was detectable in goats up to 24 h. Plasma concentrations vs. time data of T after 200 mg/kg oral administration of NTZ in goats were adequately described by one-compartment open model with first order absorption. As to free T, the values of t(1/2Ka), t(1/2Ke), T(max), C(max), AUC, V/F((c)), and Cl((s)) were 2.51 +/- 0.41 h, 3.47 +/- 0.32 h, 4.90 +/- 0.13 h, 2.56 +/- 0.25 microg/mL, 27.40 +/- 1.54 (microg/mL) x h, 30.17 +/- 2.17 L/kg, and 7.34 +/- 1.21 L/(kg x h), respectively. After beta-glucuronidase hydrolysis to obtain total T, t(1/2ke), C(max), T(max), AUC increased, while the V/F((c)) and Cl((s)) decreased. Study of the protein binding ability showed that T with 4 microg/mL concentration in goat plasma and in the albumin solution achieved a protein binding percentage of more than 95%, while in the solution of alpha-1-acid-glycoprotein, the percentage was only about 49%. This result suggested that T might have much more potent binding ability with albumin than with alpha-1-acid-glycoprotein, resulting from its acidic property.

Neoadjuvant chemoradiotherapy for locally advanced low-lying rectal cancer

e15095

Objective: The aim of this trial was to explore the possibility of further improvement of efficacy in neoadjuvant chemoradiation for the treatment of locally advanced low-lying rectal cancer and the management of patients with clinical complete regression. Methods: 192 cases with locally advanced low-lying rectal cancer (T3/T4 or N+) received preoperative radiotherapy comprising 40–46 Gy/20–23 fractions and concomitant oral capecitabine 625 mg/m2 bid for 10 weeks prior to surgery. Curative resection with TME was carried out 6 weeks after the end of radiation. Results: Patients (pts) were recruited from May 2001 through August 2007. Overall, 117 pts (60.9%) experienced adverse events but only 2 suffered from grade 3 hand-foot syndrome. 17 pts (8.9%) had clinical complete tumor regression without surgery, 175 pts underwent curative resection including of 134 pts with low anterior resection (LAR), 32 pts with ultra-low anterior resection with Parks’ coloanal anastomosis and among them 6 pts with diverting temporary colostomy and 9 pts with APR. Sphincter preservation was achieved in 95.3%. Pathologically, 24 pts (12.5%) showed CR together with 17 pts with clinical CR; the overall CR rate was 21.4%. According to the pathological staging: T0N0 41 cases, T2N0 43 cases, T3N0 77 cases, T4N0 5 cases, T2N1 11 cases, T3N1 13 cases, T4N0 5 cases, and T4N1 2 cases; in semiquantitative Dworak's tumor regression grade, TRG0 8 pts,TRG1 32, TRG2 28,TRG3 83 and TRG4 41 with an overall tumor downstaging of 79.2%. There were no operative deaths, 5 pts suffered from rectovaginal fistulas and 4 anastomotic leakages with an overall anastomotic leakage rate of 5.1% (9/175) and all recovered without further events. All patients have been followed up for a median of 46 months (range 12–87). During the time, 11 pts had lung metastases, 6 liver metastases and 7 had local recurrences. The 3-year disease-free survival was 86.6% and overall survival was 92.6%. Conclusions: Neoadjuvant chemoradiotherapy has high efficacy resulting in tumor down-staging, increased resectability and sphincter preservation, and a reduction in local recurrences. Meanwhile those patients with clinical complete response can be followed up closely and safely without surgery.

No significant financial relationships to disclose.

Adsorption and recovery of Cu (II) with polysulphone microcapsules containing chitosan gel

Polysulphone (PSF) microcapsules (PSF-CTS) containing chitosan gel with higher mechanical stability and anti-biodegradability were prepared using a novel surface coating method. The thickness and microstructures of the polysulphone coating layer were analysed by SEM. The experiments to examine the mechanical improvement of the encapsulated gel beads were carried out. The adsorption for Cu2+ and regeneration properties of unencapsulated and encapsulated gel beads were also tested. The results showed that the mechanical strength of the encapsulated gel beads was significantly enhanced. However, this improvement led to a decrease of the adsorption kinetics due to the increase of the mass transfer resistance. The potentially available methods are suggested to reduce mass transport resistance through the PSF coating layer.

[A comparative study on wound healing treated by different doses of bovine basic fibroblast growth factor (bFGF)]

OBJECTIVE

To explore the optimal dosage and method of bFGF application on surgical wound for accelerating its healing.

METHODS

Laceration wounds on the extremities of 73 patients were served as the target. The wounds were applied with three different doses of bFGF (75 Au/cm(2), 150 Au/cm(2), 300 Au/cm(2)) and with three application methods, i.e. once a day, three times a day and once a day with moistening. Normal saline with 0.5% metronidazol was employed as control agents. The wound healing time in every groups was recorded in days and compared with each other.

RESULTS

When compared to each other, the wound healing time (day) was much shorter (P < 0.05) with bFGF application in dose of 75 similar 300 Au/cm(2). There were also obvious differences in wound healing time among groups treated with the same dose but with different methods (P < 0.01). In addition, three times a day and once a day with moistening of bFGF application could further shorten the wound healing time.

CONCLUSION

Compared to the dosage of the agent, the frequency and method of bFGF application seemed more important for its optimal effects. In view of the convenience, feasibility and economy, once a day with moistening was recommended for clinical application.

Synthesis and structure-activity relationships of 2-pyrazinylcarboxamidobenzoates and beta-ionylideneacetamidobenzoates with retinoidal activity

The structure-activity relationships of two series of novel retinoids (2-pyrazinylcarboxamidobenzoates and beta-ionylideneacetamidobenzoates) have been investigated by evaluating their ability to induce differentiation in both human promyelocytic leukemia (HL60) cells and mouse embryonal carcinoma (P19) cells. The most active compound (ED50 = 8.3 x 10(-9) M) of the 2-pyrazinylcarboxamidobenzoates is 4-[2-(5,6,7,8-tetrahydro-5,5,8, 8-tetramethylquinoxalyl)carboxamido]benzoic acid (9u), while the most active analogue of the beta-ionylideneacetamidobenzoates is 4-[3-methyl-5-(2',6',6'-trimethyl-1'-cyclohexen-1'-yl)-(2E, 4E)-pentadienamido]benzoic acid (10a, ED50 = 3.2 x 10(-8) M). Our studies identify an absolute requirement for the carboxylic acid moiety on the aromatic ring to be para relative to the amide linkage for activity. Benzoate substitutions in the ortho position relative to the terminal carboxylate (9d,k,r) are well-tolerated; however, a methoxy substituent meta relative to the terminal carboxylate gives rise to only weakly active analogues (9x). Conformational studies (NMR, X-ray crystallography) of the 2-pyrazinylcarboxamidobenzoates indicate that the preferred conformation exhibits a trans-amide bond and an internal hydrogen bond between the quinoxaline N1 and HN amide which locks the torsional angle between C2 and CO in the s-trans conformation. N-Methylation (9y) results in loss of activity. Studies indicate that there is now a cis-amide bond present which redirects the carboxylate toward the pharmacophoric gem-dimethyl groups. The distance between the gem-dimethyl group and the terminal carboxylate appears to be too short to activate the retinoid receptor. N-Methylation in the beta-ionylideneacetamidobenzoate series (10c) also results in the formation of a cis-amide bond and loss of activity.

[Valve replacement in children]

We report 27 children aged 2-14 years underwent valve replacement. Twelve patients underwent mitral valve replacement, 11 tricuspid valve replacement, and 4 aortic valve replacement. Of them, 16(59.3%) were associated with cardiac malformation, 23 were in NYHA functional class III and IV in preoperation. 13 patients required additional procedures. There were 3 hospital deaths (11.1%), 4 late deaths (16.6%), and 2 reoperation. Our experiment suggested that the greater type of mechanical valve be essential for valve replacement in children, but suture technique be modified for the children with small valvular ring. After replacement of mechanical valve, low concentration anticoagulation therapy is considered as a safe and reliable method.

[Surgical treatment of ventricular septal defect in 2,169 patients]

From June 1964 to June 1993, 2,169 patients with ventricular septal defect (VSD) including perimembranous VSD (1520), subpulmonary (VSD), VSD beneath tricuspid septal leaflet in 249 patients:muscular VSD(5), left ventricle-right artrium canal VSD(7), multiple VSD(8) underwent surgical treatment. Of 271 patients associated with serious pulmonary hypertension, 51 patients had pulmonary tissue biopsy during operation and pulmonary vessels were graded. Indications for the operation of VSD, prevention of complication and management of associated lesions were discussed.

[Heparin-induced thrombocytopenia: review of the literature and description of 2 clinical cases]

We present a literary review regarding heparin-induced thrombocytopenia and we report two cases. The first case regards a female patient with a suspect pulmonary embolism and deep vein thrombosis. Low platelet count was observed already during sub-cutaneous heparin therapy but was aggravated by subsequent intra-venous treatment. The second patient developed thrombocytopenia only after intra-venous heparin infusion while previous sub-cutaneous heparin prophylaxis had not caused low platelet count. In both patients platelet counts normalized rapidly only a few hours after withdrawal of heparin treatment. We therefore point out the importance of the correct monitoring of platelet counts for a timely detection and prevention of heparin-induced thrombocytopenia, and possible consequent paradoxical thrombosis.

[Analysis of 65 cases of abruptio placenta]

From Jan 1, 1971 to Dec 12, 1990, 65 cases of abruptio placenta were admitted to our hospital. The incidence was 0.19%. Among them, thirty were complicated by pregnancy induced hypertension (46.2%). The perinatal fetal mortality was 19.7%; perinatal death occurred mostly in the premature group. All babies survived except two abnormalities. Cesarean section rate was 32.3%. All postpartum hemorrhage 29.2%. Couvelaire uterus 6.2%, were cured by conservative treatment. There was neither stillbirth nor newborn death in the thirty three cases treated expectant, but a newborn asphyxia rate of 6.1% and a cesarean section rate of 15.1%. Analysis showed that abruptio placentae should be suspected in cases with abnormal fetal heart rate of unknown cause accompanying signs of labor, premature labor of unknown cause, uterine tongue, ultrasonically visualized liquid from dark area behind the placenta, besides classical signs of abdominal pain and vaginal bleeding. Expectant treatment is appropriate if gestational age is small and no acute symptoms exists so as to minimize the perinatal mortality and cesarean section rate.

The re-expression of two myosin heavy chains in regenerated rat muscle spindles

The vascular supply and tendons of the extensor digitorum longus (EDL) muscles of two adult rats were unilaterally severed and the muscles were allowed to regenerate for 40 days. Serial frozen sections of muscle grafts were cut and stained for enzymes that delineated fiber type, sensory endings and motor endings. MF30 and ALD58, two antibodies which react only to intrafusal fibers in normal rat muscle, were reacted against sections of nerve-intact muscle grafts. Data were compared to that from muscles of normal rats. Encapsulated fibers devoid of sensory innervation and some extrafusal fibers in muscle grafts had a weak to moderate reaction to MF30, but no reaction to ALD58. Regenerated, encapsulated fibers with sensory innervation bound both MF30 and ALD58. These data indicate that afferents which reinnervate regenerated spindles retain the capacity to induce expression of spindle-specific myosin isoforms in rats.