Biomechanical evaluation of a novel atlas polyaxial transverse connecting screw system, an in vitro human cadaveric study

PURPOSE

To introduce a novel transverse connecting screw system, and to evaluate the biomechanical stability of the novel screw system using human cadaveric specimens.

METHODS

Six fresh-frozen cadaveric upper cervical spines were used in our study. Every specimen was tested under 5 conditions: intact group; unstable group; C1 to C2 screw rod system group; C1 to C2 + crosslink system group; atlas polyaxial transverse connecting screw (APTCS) system.

RESULTS

Compared with the intact state, C1 to C2 screw rod system, C1 to C2 + CL system and APTCS showed statistically decrease range of motion in all directions except for the unstable group under posterior extension direction (P < .05). APTCS group has the least range of motion in all directions (P < .001).

CONCLUSION

The APTCS system was able to restore stability to the atlantoaxial joint. APTCS system has the advantages of easy installation, convenient bone grafting, and strong biomechanical strength.

[The effect of HOXC10 gene on biological behaviors of glioma cells and mechanism in tumor microenvironment]

Objective: To study the effects of Homeobox C10 (HOXC10) on biological characteristics such as migration, invasion and proliferation of glioma cancer cells and to explore the role of HOXC10 gene in glioma microenvironment. Methods: The expression level of HOXC10 in high grade glioma (glioblastoma) and low grade glioma and its effect on patient survival were analyzed by using The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) database. Hoxc10-siRNA-1, HOXC10-siRNA-2 and siRNA negative control (NC) were transfected into U251 cells according to the operation instructions of HOXC10-siRNA transfection. 100 ng/ mL recombinant protein chemokine ligand 2 (reCCL2) was added into the transfection group, and was labeled as HOXC10-siRNA-1+ reCCL2 and HOXC10-siRNA-2+ reCCL2 groups. The expressions of HOXC10 mRNA and target protein in each group was detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and western blot. The proliferation ability of cells in each group was detected by cell counting kit 8 (CCK8) method. The migration ability of cells was detected by Transwell assay and Nick assay, and cell apoptosis was detected by flow cytometry. The expression of chemokines in each group was detected by multiple factors. Co-incubation assays were performed to determine the role of HOXC10 and chemokine ligand 2 (CCL2) in recruiting and polarizing tumor-associated macrophages (M2-type macrophages). Results: The median expression level of HOXC10 in high grade gliomas was 8.51, higher than 1.00 in low grade gliomas (P<0.001) in TCGA database. The median expression level of HOXC10 in high grade gliomas was 0.83, higher than 0.00 in low grade gliomas (P=0.002) in CGGA database. The 5-year survival rate of patients with high HOXC10 expression in TCGA database was 28.2%, lower than 78.7% of those with low HOXC10 expression (P<0.001), and the 5-year survival rate of patients with high HOXC10 expression in CGGA database was 20.3%, lower than 58.0% of those with low HOXC10 expression (P<0.001). The numbers of cell migration in HOXC10-siRNA-1 group and HOXC10-siRNA-2 group were (45±3) and (69±4) respectively, lower than (159±3) in NC group (P<0.05). The cell mobility of HOXC10-siRNA-1 group and HOXC10-siRNA-2 group at 48 hours were (15±2)% and (28±4)% respectively, lower than (80±5)% of NC group (P<0.05). The expressions of vimentin in HOXC10-siRNA-1 group and HOXC10-siRNA-2 group were (141 740.00±34 024.56) and (94 655.00±5 687.97), N-cadherin were (76 810.00±14.14) and (94 254.00±701.45), β-catenin were (75 786.50±789.84) and (107 296.50±9 614.53), lower than (233 768.50±34 114.37), (237 154.50±24 715.50) and (192 449.50±24 178.10) of NC group (P<0.05). The A value of HOXC10-siRNA-1 group and HOXC10-siRNA-2 group were (0.44±0.05) and (0.32±0.02) at 96 hours, lower than 0.92±0.12 of NC group (P<0.05). The apoptosis rates of HOXC10-siRNA-1 group and HOXC10 siRNA-2 group were (10.23±1.24)% and (13.81±2.16)%, higher than (4.60±0.07)% of NC group (P<0.05). The expression levels of CCL2 in U251 cells in HOXC10-siRNA-1 and HOXC10-siRNA-2 groups were (271.63±44.27) and (371.66±50.21), lower than (933.93±29.84) in NC group (P<0.05). The expression levels of CCL5 (234.81±5.95 and 232.62±5.72), CXCL10 (544.13±48.14 and 500.87±15.65) and CXCL11 (215.75±15.30 and 176.18±16.49) in HOXC10-siRNA-1 and HOXC10-siRNA-2 groups were higher than those in NC group (9.98±0.71, 470.54±18.84 and 13.55±0.73, respectively, P<0.05). The recruited numbers of CD14(+) THP1 in HOXC10-siRNA-1 and HOXC10-siRNA-2 groups were (159.33±1.15) and (170.67±1.15), respectively, lower than (360.00±7.81) in NC group (P<0.05), while addition of reCCL2 promoted the recruitment of CD14(+) THP1 cells (287.00±3.61 and 280.67±2.31 in HOXC10-siRNA-1+ reCCL2 group and HOXC10-siRNA-2+ reCCL2 group, respectively, P<0.05). The expressions level of M2-type macrophage-related gene TGF-β in HOXC10-siRNA-1 group and HOXC10-siRNA-2 group were (0.30±0.02) and (0.28±0.02), respectively, lower than (1.06±0.10) in NC group (P<0.05). The expressions level of M1-related gene NOS2 in HOXC10-siRNA-1 and HOXC10-siRNA-2 were (11 413.95±1 911.85) and (5 894.00±945.21), respectively, higher than (13.39±4.32) in NC group (P<0.05). Conclusions: The expression of HOXC10 in glioma is high and positively correlated with the poor prognosis of glioma patients. Knockdown of HOXC10 can inhibit the proliferation, migration and metastasis of human glioma U251 cells. HOXC10 may play an immunosuppressive role in glioma microenvironment by promoting the expression of CCL2 and recruiting and polarizing tumor-associated macrophages (M2 macrophages).

Contralateral radiculopathy after unilateral transforaminal lumbar interbody fusion: causes and prevention

Background

Unilateral transforminal lumbar interbody fusion (TLIF) with a single cage can provide circumferential fusion and biomechanical stability. However, the causes and prevention of contralateral radiculopathy following unilateral TLIF remain unclear.

Methods

In total, 190 patients who underwent unilateral TLIF from January 2017 to January 2019 were retrospectively reviewed. Radiological parameters including lumbar lordosis, segmental angle, anterior disc height, posterior disc height (PDH), foraminal height (FH), foraminal width, and foraminal area (FA) were measured preoperatively and postoperatively. Preoperative and postoperative visual analog scale scores were also recorded.

Results

The incidence of contralateral radiculopathy after unilateral TLIF was 5.3% (10/190). The most common cause was contralateral foraminal stenosis. Unilateral TLIF could increase the lumbar lordosis, segmental angle, and anterior disc height but decrease the PDH, FA, and FH in patients with symptomatic contralateral radiculopathy. The intervertebral cage should be placed to cover the epiphyseal ring and cortical compact bone of the midline, and the disc height can be increased to enlarge the contralateral foramen.

Conclusion

The most common cause of contralateral radiculopathy is contralateral foraminal stenosis. Careful preoperative planning is necessary to achieve satisfactory outcomes. Improper unilateral TLIF will decrease the PDH, FA, and FH, resulting in contralateral radiculopathy.

[Treatment strategy and curative effect analysis of os odontoideum complicated with atlantoaxial joint dislocation]

OBJECTIVE

To explore the treatment strategy and clinical efficacy for os odontoideum complicated with atlantoaxial dislocation.

METHODS

The clinical data of 17 patients with os odontoideum complicated with atlantoaxial dislocation surgically treated from January 2006 to January 2015 were retrospectively analyzed, including 7 males and 10 females, aged 17 to 53 (43.1±11.3) years old;course of disease was 3 to 27(10.2±6.9) months. All patients received cranial traction before operation, 12 of 14 patients with reducible dislocation were treated by posterior atlantoaxial fixation and fusion, and 2 patients with atlantooccipital deformity were treated by posterior occipitocervical fixation and fusion;3 patients with irreducible alantoaxial dislocation were treated by transoral approach decompression combined with posterior atlantoaxial fixation and fusion. The operation time, intraoperative blood loss and perioperative complications were recorded. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the change of neck pain and neurological function. Atlantoaxial joint fusion rate was evaluated by CT scan.

RESULTS

The operation time of posterior fixation and fusion ranged from 86 to 170 (92.2±27.5) min, and the intraoperative blood loss was 200-350 (250.7±65.2) ml. No vertebral artery injury and spinal cord injury were recorded. Among the patients underwent atlantoaxial fixation and fusion, 1 patient with reducible dislocation fixed by C₂ laminar screw lost reduction after primary operation, and received anterior release again and finally occipitocervical fusion. All patients were followed up for 15 to 58 (32.0±12.2) months. VAS score was decreased from preoperative 4.2±0.9 to 1.3±0.7 at final follow up and the JOA score was improved from preoperative 11.2±1.2 to 16.9±0.8 at final follow-up. CT scan confirmed that the atlantoaxial or occipitocervical fusion wasgood, and the fusion time was 5 to 9 (6.7±0.6) months.

CONCLUSION

Surgical treatment of os odontoideum complicated with atlantoaxial dislocation can achieve satisfactory results, improve the patient's neurological function and improve the quality of life, however the surgical options needs to be individualized.

[Minimally invasive direct lateral approach debridement, interbody bone grafting, and interbody fusion combined with posterior percutaneous pedicle screw fixation for lumbar spinal tuberculosis]

OBJECTIVE

To investigate the clinical efficacy and superiority of direct lateral interbody fusion combined with posterior percutaneous screw fixation in the treatment of lumbar tuberculosis.

METHODS

From June 2013 to August 2016, the clinical data of 83 patients with lumbar tuberculosis were retrospectively analyzed, including 55 males and 28 females, aged from 27 to 72 (49.5±13.5) years. These 83 patients were divided into two groups according to different operation methods, 35 cases in group A were treated with direct lateral interbody fusion combined with posterior percutaneous screw fixation;48 cases in group B were treated with anterior traditional extraperitoneal debridement combined with posterior internal fixation. After operation, regular quadruple antituberculosis drugs were continued for 18 months. The operation time, intraoperative blood loss, hospital stay, bone graft fusion time and complications were compared between the two groups. Visual analogue score (VAS) of lumbar pain, Oswestry Disability Index (ODI), sagittal Cobb angle, erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP) values before and after operation were analyzed.

RESULTS

The operation was successfully completed in both groups, and the operation mode was not changed during operation. The operation time, intraoperative blood loss and hospital stay were (149.4±13.3) min, (354.3±69.0) ml, (9.4±1.6) d in group A and(116.8±10.0) min, (721.9±172.3) ml, (11.8±1.7) d in group B, respectively, with significant difference between the two groups (P<0.05). The follow up time was (24.2±5.1) months in group A and (24.0±5.0) months in group B, there was no significant difference between two groups (P>0.05). At the follow-up of 4 months after operation, one patient in group A was found to have enlarged psoas major abscess on the contralateral side, and was cured after secondary operation. No sinus formation, cerebrospinal fluid leakage, internal fixation loosening, fracture or distal junction kyphosis were found during follow-up. The fusion time was (5.1±1.6) months in group A and (5.1± 1.7) months in group B, there was no significant difference between two groups (P>0.05). The VAS, ODI score, sagittal Cobb angle, ESR and CRP value of the lesion segment at the last follow-up of the two groups were significantly improved (P<0.05), but there was no significant difference between two groups (P>0.05).

CONCLUSION

The two kinds of operation can obtain satisfactory clinical effect. Direct lateral interbody fusion combined with posterior percutaneous screw fixation can reduce intraoperative blood loss and hospital stay, which is conducive to early rehabilitation of patients.

[Comparison of the effects of injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty in the treatment of osteoporotic thoracolumbar burst fractures]

OBJECTIVE

To assess the curative effects of injured vertebra pedicle fixation combined with vertebroplasty and short-segment pedicle screw fixation combined with vertebroplasty in treatment of osteoporotic thoracolumbar burst fractures.

METHODS

Seventy patients with osteoporotic thoracolumbar burst fractures who met the inclusion criteria were collected in the study from January 2015 to December 2017. Among them, 35 patients were treated with injured vertebra pedicle fixation combined with vertebroplasty (group A), including 20 males and 15 females, aged from 55 to 74 years with an average of (64.03± 7.82) years. Twenty-six cases were type A3 and 9 cases were type A4 according to the AO typing;another 35 patients were treated with short segment pedicle screw fixation combined with vertebroplasty (group B), including 18 males and 17 females, aged from 54 to 72 years with an average of (62.78±6.40) years. Twenty-eight cases were type A3 and 7 cases were type A4 according to AO typing. Operation length, intraoperative bleeding volume, complication, imaging parameters and clinical effects were compared between the two groups.

RESULTS

All the patients were followed up for at least 12 months. There were no significant differences in gender, age, injury site, preoperative VAS, Cobb angle, and injured vertebral height before surgery. There were no significant differences in operation length, intraoperative bleeding volume between two groups. In terms of VAS scores before surgery, 1 week after surgery, and at the final follow up, group A was 5.5 ±2.5, 1.8 ±0.8, 0.9 ±0.4, group B was 5.4 ± 2.3, 1.7±0.6, 1.2±1.8, respectively;injured vertebral height was (40.4±8.8)%, (92.0±4.9)%, (87.1±3.8)% in group A, and (41.2±6.6)%, (93.2±4.6)%, (80.0±4.3)% in group B;Cobb angle was (18.4±6.9) °, (2.8±2.2) °, (4.2±2.6) ° in group A, and (16.8±7.2) °, (2.7±2.5) °, (6.0±2.4) ° in group B. There were significant differences in the 3 parameters above before the operation and at the final follow up in all groups (P<0.05). There were significant differences in the Cobb angle and injured vertebral height between 1 week after operation and at the final follow up (P<0.05). At the final follow up, injured vertebral height in group A was obviously better than that in group B (P<0.05). Internal fixation failure occurred in 2 cases from the group A, and occurred in 4 cases from the group B. There were no neurological complications in both groups.

CONCLUSION

For osteoporotic thoracolumbar vertebral burst fractures, injured vertebra pedicle fixation combined with vertebroplasty and vertebra pedicle screw fixation combined with vertebroplasty can achieve good clinical effects. However, injured vertebra pedicle fixation combined with vertebroplasty is better at maintaining postoperative vertebral height and sagittal arrangement, and reducing internal fixation related complications. The treatment strategy is worthy of application and promotion.

Population Structure and Genetic Diversity of Fungi Causing Rice Seedling Blight in Northeast China Based on Microsatellite Markers

Rice seedling blight, which is caused by diverse pathogenic microorganisms, occurs worldwide and is the most important seedling disease affecting rice production in Northeast China. To further characterize the population structure and genetic diversity of the fungi responsible for rice seedling blight in Northeast China, 225 fungal strains were isolated from diseased rice seedlings collected from various rice-producing areas. The isolated strains included Fusarium oxysporum (48.0%), F. verticillioides (11.6%), F. tricinctum (8.0%), F. redolens (6.7%), F. equiseti (6.2%), F. solani (6.2%), Rhizoctonia solani (6.7%), Alternaria alternata (4.0%), and Curvularia coatesiae (2.7%). F. oxysporum was the dominant fungal species causing rice seedling blight, with most isolates exhibiting moderate pathogenicity. Moreover, to our knowledge, this is the first study to identify A. alternata and C. coatesiae as causal agents of rice seedling blight in Northeast China. None of the F. oxysporum isolates were sensitive to 10 μg/ml of carbendazim, implying that carbendazim is ineffective for controlling rice seedling blight in Northeast China. The F. oxysporum isolates were divided into nine groups based on a simple sequence repeat analysis involving 14 primer pairs. In addition, an analysis of molecular variance revealed a significant correlation between the F. oxysporum population and geographical location, which had a significant effect on the differentiation of the dominant isolate population. The results of this study provide insights into the genetic diversity of F. oxysporum strains causing rice seedling blight and may be useful for selecting isolates to screen for disease-resistant rice varieties, evaluating fungicide efficacy, and developing effective disease management strategies.

[Effect of posterior osteotomy on the sagittal parameters of the spinopelvis in patients with lumbar degenerative kyphosis]

OBJECTIVE

To investigate the influence of posterior osteotomy on spinopelvic parameters in lumbar degenerative kyphosis (LDK) patients.

METHODS

The clinical data of 21 patients with lumbar degenerative kyphosis who underwent osteotomy from January 2012 to December 2015 were retrospectively analyzed. There were 5 males and 16 females, aged from 55 to 76 years with an average of (66.24±5.13) years. All patients had taken preoperative and postoperative full length spinal X-ray, analyzing the spinopelvic parameters as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS).

RESULTS

All operations were successful, the average operative time was 190 min (160 to 220 min) and intraoperative blood loss was 1 000 ml (800 to 1900 ml). Parameters of the patients between preoperative and period 1-year follow-up were as follows : preoperative TK increased from (31.67±21.13) ° to (34.67±11.60) °, LL corrected from (4.76±3.17) ° to (37.41±6.28) °, PT reduced from (33.94±5.01) ° to (20.12±5.36) °, and SS improved from (18.47±2.60) ° to (31.71±4.30) °, SVA restored from (13.24±3.60) cm to (2.82±1.33) cm. There were significant differences of spinopelvic parameters between preoperation and postoperation (P<0.05).

CONCLUSION

Posterior osteotomy can effectively reconstruct the sagittal balance of spinopelvis in patients with lumbar degenerative kyphosis. The recovery of lumbar lordosis and sacral slope is closely related to the reconstruction of sagittal balance.

[Value of detection of extracellular vesicles in the diagnosis of nonalcoholic fatty liver disease]

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells, and hence participate in the variety of diseases including the occurrence and development of liver diseases. In recent years, the prevalence of nonalcoholic fatty liver disease (NAFLD) has increased. Currently there is no reliable method except invasive liver biopsy for the diagnosis of liver inflammation or fibrosis staging. Therefore, the search for the corresponding markers of noninvasive circulation continues to be active, and extracellular vesicles are one of the most concerned. To this end, we reviewed current knowledge about the physical characteristics, biological components, and isolation methods of extracellular vesicles, and introduced the concept of using circulating cell-derived vesicles as a new diagnostic marker for nonalcoholic fatty liver disease.

Population structure and genetic diversity of Setosphaeria turcica from corn in Heilongjiang province, China

AIM

The aims of this study were to identify races and mating types of Setosphaeria turcica causing northern corn leaf blight in Heilongjiang province of China and analyse the genetic diversity of S. turcica isolates using SSR markers.

METHODS AND RESULTS

Based on gene-for-gene interactions, 13 races of S. turcica (races 0, 1, 2, 3, 12, 13, 23, 123, N, 1N, 12N, 3N and 23N) were isolated from infected corn plants in Heilongjiang province. Races 0 and 1 were the predominant races, and race 23N was identified for the first time in the region. Using two pairs of specific primers, three mating types, 'a', 'Aa' and 'A', were identified, with 'a' being the predominant mating type. SSR markers were used to analyse genetic diversity of 60 S. turcica isolates. Five SSR primers were polymorphic, which resulted in 45 reproducible bands with 2-15 bands for each primer. Cluster analysis separated the isolates into five groups at a similarity coefficient of 0·84. Analysis of molecular variance showed that there was significant correlation between SSR groups and mating type of the isolates. No significant correlation was found between SSR groups and physiological races or geographical location of the isolates.

CONCLUSIONS

The work reported that races 0 and 1 were the predominant races, and race 23N was identified for the first time in Heilongjiang province with 'a' being the predominant mating type. There was significant correlation between SSR groups and mating type of S. turcica isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide information on population structure and genetic diversity of S. turcica causing Northern corn leaf blight, which will facilitate the development of effective disease management programs.

[Efficacy of bilateral sagittal cross percutaneous kyphoplasty for preventing recurrent fracture of the cemented vertebrae]

OBJECTIVE

To explore the efficacy of bilateral sagittal cross percutaneous kyphoplasty(PKP) for preventing recurrent fracture of the cemented vertebrae.

METHODS

From January 2017 to June 2017, 85 patients with single-segment osteoporotic vertebral compression fractures(OVCFs) were treated by bilateral sagittal cross PKP(cross group). There were 35 males and 50 females with an average age of (70.1±8.3) years old in cross group. Another 85 patients with single-segment OVCFs were treated by traditional PKP (traditional group). There were 37 males and 48 females with an average age of (73.3±9.5) years old in traditional group. The cement distribution condition, recurrent fracture of the cemented vertebrae, the anterior vertebral body height and sagittal Cobb angle, visual analogue scale(VAS) were observed in two groups.

RESULTS

All patients underwent operation successfully. The follow-up time were (11.8±4.5) months in cross group and (12.1±3.7) months in traditional group. In cross group, all patients' bone cement touched the upper and lower endplates of the vertebral body while 67 cases (78.8%) in traditional group did with significant difference between two groups (P<0.05). No patient in cross group suffered recurrent fracture of the cemented vertebrae while 10 cases (11.8%) in traditional group did with significant difference between two groups(P<0.05). The anterior vertebral body height, sagittal Cobb angle and VAS in both groups were obvious improved at 2 days after operation (P<0.05) and there were no significant difference between two groups at 2 days after operation and the final follow-up(P>0.05).

CONCLUSIONS

Bilateral sagittal cross PKP was a simple, safe and effective technique which can make bone cement distribute in the fractured vertebral body and contact the upper and lower endplates of the vertebral body, thus preventing the recurrent fracture of the cemented vertebrae.

[One stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers]

OBJECTIVE

To assess the clinical results of one stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers.

METHODS

From February 2009 to April 2015, 19 teenagers with Grauer type IIB dens fractures not amenable to anteiror screw fixation were enrolled and treated using one stage temporary atlantoaxial segmental fixation and reduction without fusion. There were 14 males and 5 females, aged from 14 to 32 years with an average of (24.6±5.0 ) years. The internal fixation was removed after bone healing confirmed by CT scan. At the last follow-up (at least 1 year after internal fixation removal), dynamic CT was used to assess the atlantoaxial rotation activity. Visual analogue scale (VAS) was recorded before the first operation, before the second operation (removal of internal fixation) and at the last follow-up. Neck Disability Index(NDI) was used to evaluate the efficacy before the second operation (removal of internal fixation) and the last follow-up.

RESULTS

After operation, 2 patients developed the symptoms of occipital nerve stimulation such as numbness and pain in the occipitocervical region, and were treated with drugs such as dehydration and neurotrophic drugs, and the symptoms were relieved after 1 to 2 months. All the internal fixations were removed and all the patients were followed up more than 1 year, with time ranging from 18 to 25 months and an average of (21.47±2.41) months. The time of bone fusion after operation was 6 to 10 months with the mean of(8.21±1.27) months. Secondary surgical removal of internal fixation were performed immediately after fracture healing without internal fixation failure. The symptoms of neck pain improved significantly after operation, VAS score decreased from 6.74±0.65 before operation to 0.42±0.51 at the last follow-up after the second operation (removal of internal fixation), with statistically significant differences(P<0.01). The NDI value decreased from (10.58±2.04)% before the second operation (removal of internal fixation) to (3.79±2.23)% at the last follow-up after the second operation (removal of internal fixation), with statistically significant difference(P<0.01). At the last follow-up after the second operation (removal of internal fixation), dynamic CT showed that the unilateral rotation of the atlantoaxial spine reached (15.73±5.57)° to the left, (15.55±5.78)° to the right, and the overall rotation of the atlantoaxial spine was (31.28±10.71)°.

CONCLUSIONS

One stage temporary atlantoaxial segmental fixation and reduction for the treatment of Grauer type IIB dens fractures not amenable to anteiror screw fixation in teenagers can avoid the loss of atlantoaxial rotation function caused by atlantoaxial fusion, and to some extent retain the rotation activity of atlanto-axial joint.

[Treatment of senile spinal tuberculosis with posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement]

OBJECTIVE

To explore the short-term efficacy of posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement in treating senile spinal tuberculosis.

METHODS

The clinical data of 19 senile patients with spinal tuberculosis underwent surgical treatment from January 2015 to September 2016 were retrospectively analyzed. There were 13 males and 6 females, aged from 60 to 73 years old with an average of (66.2±4.0) years. All patients have been diagnosed with spinal tuberculosis prior to hospitalization with abscess, dead bone formation but no sinus, neurological symptoms, open surgical indications. All patients were treated with posterior percutaneous screw fixation combined with local percutaneous endoscopic debridement, and were given appropriate chemotherapy for 3 weeks preoperatively. Pre-and post-operative visual analogue score (VAS), Oswestry Disability Index (ODI), sagittal Cobb angle of lesion segment, erythrocyte sedimentation rate(ESR), C-reactive protein(CRP) were analyzed.

RESULTS

All the 19 patients successfully completed the operation and passed through the perioperative period safely. The operation method was unchanged during the operation. The average operation time was (153.2±14.0) min. Except for 1 patients who had delayed incision healing, other patients healed at I stage within 2 weeks after operation. All patients were followed up for 15 to 26 months with an average of (19.6±3.2) months.VAS, ODI, sagittal Cobb angle of lesion segment, ESR, CRP were decreased from preoperative(5.9±1.1) points, (80.9±4.0)%, (30.8±5.5)°, (79.6±14.4) mm/h, (56.9±9.5) mg/L to(1.8±0.9) points, (66.4±5.4)%, (15.9±2.5)°, (20.4±4.6) mg/L, (32.0±8.1) mm/h at final follow-up(P<0.05).

CONCLUSIONS

Senile spinal tuberculosis have more complications and poor general body condition. Posterior percutaneous pedicle screw fixation combined with local percutaneous endoscopic debridement in treating the patients can reduce trauma, got satisfactory effect.

[Case-control study of pedicle screw fixation combined with vertebroplasty and injured vertebra pedicle fixation in treatment of osteoporotic thoracolumbar burst fractures]

OBJECTIVE

To compare the curative effect of short-segment pedicle screw fixation combined with vertebroplasty and injured vertebra pedicle fixation in treating osteoporotic thoracolumbar burst fractures.

METHODS

A retrospective study was performed for 52 patients with thoracolumbar burst fractures from August 2010 to August 2015. Among them, 27 patients(group A) were treated with short-segment pedicle screw fixation combined with vertebroplasty, including 17 males and 10 females, aged from 54 to 68 years old with an average of(61.01±5.41) years, 16 cases were type A3 and 11 cases were type A4 according the new AO typing. Other 25 patients (group B) were treated with short-segment pedicle screw fixation combined with injured vertebra pedicle fixation, including 12 males and 13 females, aged from 55 to 66 years old with an average of (59.28±6.12) years, 18 cases were type A3 and 7 cases were type A4 according the new AO typing. Operation time, intraoperative bleeding volume, complication, image data and clinical effect were compared between two groups.

RESULTS

All the patients were followed up for 12 to 15 months with an average of (12.4±2.1)months. There was no significant difference in general data(including gender, age, injured site, preoperative VAS score, Cobb angle, injured vertebral anterior border height) between two groups. There was no significant differences in operation time, intraoperative bleeding volume between two groups. Preoperative, one week after operation and final follow-up, VAS scores were 5.2±0.5, 1.2±0.2, 0.8±0.1 respectively in group A and 5.0±0.6, 2.5±0.4, 1.3±0.2 in group B; injured vertebral anterior border height were (49.4±6.8)%, ( 94.5±1.2)%, ( 94.1±3.7)% respectively in group A and (48.2±7.0)%, ( 94.3±4.1)%, ( 90.0±2.3)% in group B;Cobb angles were (20.4±5.2) °, (2.5±1.8) °, (4.4±1.7)° respectively in group A and (19.8±6.8)°, (2.4±1.7)°, (7.0±1.2)° in group B. At final follow-up, VAS, Cobb angle, injured vertebral anterior border height in two groups were obviously improved(P<0.05). Postoperative at 1 week and final follow-up, VAS score of group A was lower than that of group B(P<0.05);and there was no significant difference in Cobb angle between two groups(P>0.05); there was significant difference in injured vertebral anterior border height between two groups(P<0.05). The complication of internal fixation failure had 1 case in group A and 4 cases in group B.

CONCLUSIONS

For the treatment of single osteoporotic thoracolumbar burst fractures, short-segment pedicle screw fixation combined with vertebroplasty is better than combined with injured vertebra pedicle fixation in clinical effect, it can relieve pain, maintain injured vertebral height and sagittal alinement, reduce the complications associated with internal fixation, and be worth spread in clinic.

[Percutaneous pedicle screw fixation combined with limited-open decompression technique for thoracolumbar fractures with neurologic deficit]

OBJECTIVE

To evaluate the clinical effects of percutaneous pedicle screw fixation combined with limited open decompression technique for the treatment of thoracolumbar fractures with neurologic deficit.

METHODS

The clinical data of 76 patients with thoracolumbar fractures with neurologic deficit underwent percutaneous pedicle screw fixation combined with limited open decompression technique from June 2010 to June 2014 were retrospectively analyzed. There were 45 males and 31 femals, aged from 17 to 56 years with an average of 32.5 years old. According to the classification of Denis, 33 cases were type A, 26 cases were type B, 17 cases were type C. According to the criterion of American Spinal Injury Association(ASIA), 13 cases were grade A, 9 cases were grade B, 21 cases were grade C, 33 cases were grade D. The operative time, intraoperative blood loss, postoperative internal fixation lossening and breakage were recorded. The informations of the Cobb angle, the anterior height of injured vertebra, canal stenosis were observed before operation, 3 days after operation, and the final follow-up. The improvement of neurologic function were analyzed at final follow-up.

RESULTS

All the patients were followed up from 13 to 47 months with an average of 32.1 months. The mean operative time was 159 min (136 to 218 min) and the intraoperative blood loss was 225 ml(150 to 360 ml). The anterior height of injured vertebra was increased from (52.0±5.9)% before operation to (87.2±1.8)% at 3 days after operation, and (86.1±1.5)% at final follow-up (F=45.27, P=0.000); the Cobb angle was decreased from (29.7±8.2)° before operation to (5.7±2.9)° at 3 days after operation, and (5.9±3.6)° at final follow-up (F=34.62, P=0.000); the canal stenosis was decreased from (37.5±7.2)% before operation to (12.3±3.3)% at 3 days after operation, and (11.9±3.1)% at final follow-up(F=37.02, P=0.000); there was no significant differences between postoperative 3 days and the final follow-up about the above parametres(P>0.05). According to ASIA criterion, the spinal cord function was classified as grade A in 13 cases, grade B in 0 cases, grade C in 10 cases, grade D in 21 cases and grade E in 32 cases at final follow-up. Internal fixation lossening and breakage occurred in 2 cases.

CONCLUSIONS

Percutaneous pedicle screw fixation combined with limited open decompression technique can obtain satisfactory clinical effect for patients with thoracolumbar fractures with neurologic deficit, and have a good recovery of nerve function can be observed.

Establishing a comprehensive genetic diagnosis strategy for hemophilia B and its application in Chinese population

INTRODUCTION

To reduce the incidence of hemophilia B (HB) which with no complete cure currently, prenatal diagnosis and preimplantation genetic diagnosis (PGD) are effective and feasible means. However, previous studies about genetic diagnosis in HB mostly just focused on the detection of patients and carriers. Here, we established a comprehensive genetic diagnosis strategy for HB and worked it out in Chinese population. The strategy includes the detection of patients and carriers, prenatal diagnosis, and PGD.

METHODS

Seven unrelated HB families from Chinese population involved in this study. Firstly, probands and available members were carried out coagulation laboratory assays, and the clinical information has been recorded. Secondly, we used DNA direct sequencing to screen the whole FIX gene of them. The pathogenicity of novel mutations was verified according to 2015 ACMG-AM guidelines. For prenatal diagnosis, a mix of DNA direct sequencing and STR linkage analysis was employed. To explore a better PGD protocol, Karyomapping was first applied in PGD of HB, comparing with conventional PCR-based methods.

RESULTS

Six different pathogenic mutations including 1 novel duplication (c.660_661dup ATCA) were identified. The results of prenatal diagnosis were consistent with birth outcomes. In the PGD case, 4 of 11 embryos were confirmed to be normal and one of them was transferred and led to a healthy birth.

CONCLUSIONS

The established genetic diagnosis strategy for HB in our study was comprehensive and well applied in clinic practice. Besides, we recommended that DNA direct sequencing combined with Karyomapping was a better PGD protocol.

[French door segmented laminectomy decompression for severe cervical ossification of posterior longitudinal ligament complicated with spinal cord injury]

OBJECTIVE

To evaluate the clinical effects of French door segmented laminectomy decompression for severe cervical OPLL complicated with spinal cord injury.

METHODS

The clinical data of 38 patients with serious cervical OPLL complicated with spinal cord injury were retrospectively analyzed and these patients were treated with French door segmented laminectomy decompression and internal fixation from June 2012 to June 2014. There were 25 males and 13 females, aged from 42 to 78 years with an average of 58.2 years. Of them, 35 cases suffered from aggravating neurological symptoms with a definite precipitating factor. Spinal cord injury was related to minor injury of the neck, such as hyperextension of the neck in 3 cases. Preoperative Japanese Orthopaedic Score (JOA) was 8.1±1.7 and Neck Disability Index (NDI) was 19.8±4.4. Preoperative CT scans showed the range of OPLL was more than three segments. The spinal canal was occupied 50% to 85% with an average of 70.7%.

RESULTS

All the patients were followed up for 10 to 24 months with an average of 15.6 months. The operative time was 90 to 150 min with an average of 120 min and blood loss was 300 to 800 ml with an average of (480±80) ml. At final follow-up, NDI and JOA were 7.5±2.5 and 13.5±2.0, respectively, and they were obviously improved compared with preoperation. Preoperative cervical Cobb angle was (8.10±2.70)° and at final follow-up was (15.60±1.80)°, and there was significant difference between preoperative and postoperative (P<0.05). Deep infection occurred in 1 case, epidural hematoma in 1 case, C₅ nerve root palsy in 3 cases, and axial symptom in 8 cases after operation. No serious complications, such as vertebral artery injury, cerebrospinal fluid leakage, deterioration of neurological dysfunction, or internal fixation failure was found.

CONCLUSIONS

French door segmented laminectomy decompression is safe and feasible for severe cervical OPLL complicated with spinal cord injury, and it is worth to be popularized in future.

[The shor-term clinical outcomes and safety of extreme lateral interbody fusion combined with percutaneous pedicle screw fixation for the treatment of degenerative lumbar disease]

OBJECTIVE

To evaluate the early efficacy and safety of extreme lateral interbody fusion (XLIF) combined with percutaneous pedicle screw fixation for lumbar degenerative disease.

METHODS

From January 2013 to June 2014, 13 patients with degenerative lumbar disease were treated with XLIF combined with percutaneous pedicle screw fixation, including 8 cases of lumbar instability, 5 cases of mild to moderate lumbar spondylolisthesis;there were 5 males and 8 females, aged from 56 to 73 years with an average of 62.1 years. All patients were single segment fusion. Operation time, perioperative bleeding and perioperative complications were recorded. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were used to evaluate the clinical efficacy. Interbody fusion rate was observed and the intervertebral foramen area changes were compared preoperation and postoperation by X-rays and CT scanning.

RESULTS

The mean operation time and perioperative bleeding in the patients respectively was(62.8±5.2) min and(82.5±22.6) ml. One case occurred in the numbness of femoribus internus and 1 case occurred in the muscle weakness of hip flexion after operation, both of them recovered within 2 weeks. All the patients were followed up from 12 to 19 months with an average of 15.6 months. VAS was decreased from preoperative 7.31±0.75 to 2.31±0.75 at final follow-up(P<0.05); ODI was decreased from preoperative (42.58±1.55)% to (12.55±0.84)% at final follow-up(P<0.05). At final follow-up, CT scanning confirmed 8 cases completely fused and 5 cases partly fused;the intervertebral foramen area was increased from preoperative (94.86±2.44)mm2 to (150.70±7.02)mm2(P<0.05).

CONCLUSIONS

Extreme lateral interbody fusion combined with percutaneous pedicle screw fixation is an ideal method and can obtain early good clinical effects in treating lumbar degenerative disease.

[Effect of reduction on spino-pelvic parameters in treating high-grade lumbar spondylolisthesis]

OBJECTIVE

To explore the effect of reduction on spino-pelvic balance in treating high-grade lumbar spondylolisthesis.

METHODS

From Augest 2008 to Augest 2011, the data of 16 patients with high-grade lumbar spodylolisthesis (Meyerding grade III or more than grade III) underwent reduction treatment through posterior approach were retrospectively analyzed. There were 9 males and 7 females, aged from 24 to 65 years old with an average of 44 years. Preoperative, postoperative at 2 weeks and final follow-up, spino-pelvic parameters of all patients were measured and compared by total legth lateral X-rays, and spino-pelvic parameters included sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL) and sagittal vertical axis (SVA); the informations of intervertebral bone fusion was observed by CT and postoperative complications were recorded; clinical effects were assessed according to clinical Oswestry score (CODI).

RESULTS

All patients were followed up from 12 to 24 months with an average of 18 months. Four cases reduced anatomically, 8 cases reduced to grade I .4 cases reduced to grade II. There was statistically significant differences in sacral slope (SS), pelvic tilt (PT), lumbar lordosis angle (LL) and sagittal vertical axis (SVA) between before operation and two weeks after operation (P < 0.05), while pelvic incidence (PI) no statistically significant differences was found between before operation and two weeks after operation (P > 0.05). There was no statistically significant differences in SS, PT, LL, SVA, PI between two weeks after operation and final follow-up (P > 0.05). CODI had decreased from preoperative 36.6 ± 4.2 to 14.7 ± 4.0 at final follow-up (P < 0.05). One year after operation, all patients obtained bone fusion and can find the union of bone trabeculae by three-dimensional reconstruction CT. Three cases occurred transient nerve root pain, and recovered after medicinal treatment. No infection and internal fixation loosening and breakage were found.

CONCLUSION

Surgical reduction for high-grade lumbar spondylolisthesis can improve spino-pelvic balance and acquire satisfactory outcomes.

[Asymmetrical osteotomy for elderly degenerative lumbar kyphoscoliosis]

OBJECTIVE

To investigate the safety and efficacy of asymmetrical osteotomy in treating elderly degenerative lumbar kyphoscoliosis.

METHODS

From January 2010 to June 2012,17 elder patients with degenerative lumbar kyphoscoliosis were treated with asymmetrical osteotomy,their data were retrospectively analyzed. There were 6 males and 11 females with an average age of 61 years old (57 to 72). Total length spinal X-ray was performed for all patients before operation,and sagittal and coronal balance were analyzed. The follow-up time was 1 year at least. VAS score, thoracolumbar Cobb angle and pelvic parameters were analyzed.

RESULTS

All patients were operated successfully. The average operation time was 210 min (180 to 260) and intraoperative blood loss was 1,100 ml (750 to 2 200). At 1 year after operation, VAS score decreased from preoperative 7.0 +/- 1.5 to 1.1 +/- 0.6; lumbar lordosis (LL) corrected from (1.9 +/- 9.6) degrees to (35.2 +/- 6.7) degrees; thoracic kyphosis (TK) increased from (26.3 +/- 9.7) degrees to (32.5 +/- 11.2) degrees; lumbar scoliosis decreased from (25.1 +/- 11.0) degrees to (7.9 +/- 3.6) degrees; pelvic tilt (PT) restored from (33.0 +/- 10.1) degrees to (25.3 +/- 8.9) degrees; sacral slope (SS) increased from (13.9 +/- 9.7) degrees to (27.2 +/- 11.0) degrees; sagittal balance improved from (10.3 +/- 8.1) cm to (3.1 +/- 4.2) cm,and coronal balance improved from (3.5 +/- 2.1) cm to (1.3 +/- 1.1) cm. There was statistically significant difference above data between preoperation and postoperation.

CONCLUSION

Asymmetrical osteotomy can not only correct scoliosis deformity, but also restore lumbar lordosis, and may safely and effectively solve the problem of elderly degenerative lumbar kyphoscoliosis.

[The design and application of anterior cervical pedicle screw-plate system in lower cervical spine]

OBJECTIVE

To explore the applied feasibility of the anterior cervical pedicle screw-plate system in lower cervical spine,in order to provide basic data for clinical application.

METHODS

Total thirty-two units (functional spinal unit, FSU) were got randomly from 16 cervical speciments, 8 units in each group of C3,4, C4,5, C5,6 and C6,7. The anterior cervical pedicle screw-plate system was implanted to reconstruct the stability of FSU after discectomy and bone graft. The adaptability was measured between the screw-plate system and vertebral body. X-ray and CT were used to evaluate the accuracy of anterior cervical pedicle screws. The subject will be dissected to identify the situation of involvement if screw perforating the pedicle.

RESULTS

Sixty-four anterior pedicle screws were inserted smoothly in the 32 units. The screw and the plate were harmonious locked in the system. The position and length of all screws were satisfactory through X-ray views. However,6 screws perforated the transpedicular (degree 1) according to CT axial views,2 internally cortex and 4 laterally cortex. None perforation was degree 2 or more. None cervical sac compression and nerve root injury was observed in two internal perforation cadavers. One vertebral vein involvement was found in the four lateral perforation screws. The vertebral artery was not pinched though one screw near to the artery.

CONCLUSION

The anterior cervical pedicle screw-plate system is adapted to reconstruct in lower cervical spine and it deserved to be used for clinical application.

[Clinical application of anterior transpediclar screw reconstruction in treating lower cervical spine fracture and dislocation]

OBJECTIVE

To investigate the clinical effects of anterior transpediclar screw (ATPS) fixation in treating lower cervical spine fracture and dislocation.

METHODS

From January 2009 to December 2011, 18 patients with lower cervical spine fracture and dislocation were treated with ATPS technique, including 12 males and 6 females, aged from 17 to 47 years old with an average of 38.2 years. Severity score of lower cervical spine injuries (SLIC) ranged from 6 to 9 points with an average of 7.5 points. According to ASIA grade of spinal cord injury, 2 cases were classified in grade A, 8 cases in grade B, 6 cases in grade C and 2 cases in grade D. X-ray and CT scan were done after surgery in order to evaluate the safety of ATPS and observe the stability and fusion of injured segment. Spinal cord function was evaluated according to ASIA grade at 3 months after operation and last follow-up.

RESULTS

All patients were followed up for 6 to 15 months with an average of 9.5 months. Three months after operation, in aspect of spinal cord function, 8 cases improved 1 grade, 2 cases improved 2 grades; and at final follow-up, 7 cases improved 1 grade, 4 cases improved 2 grades. All patients obtained bony fusion 6 to 8 months after operation with an average of 6.5 months. After operation, 1 case had transient hoarseness and recovered 2 months later;2 cases felt swallowing discomfort, but the symptoms disappeared after about 3 weeks by inhalation. No internal fixation breakage and loosening as well as nerve, blood vessel and esophageal injuries were found.

CONCLUSION

As for three columns injury caused by lower cervical spine fracture and dislocation, treatment with anterior transpediclar screw reconstruction can achieve the effect of decompression thoroughly and restore the cervical spine height and physiological curvature. Moreover, this kind of treatment has good stability and can create the favorable conditions for the recovery of spinal cord function.

[Comparison of statics characteristics between anterior transpedicular screws system and vertebral body screws system in lower cervical spine]

OBJECTIVE

To compare statics characteristics between anterior transpedicular screws (ATPS) system and vertebral body screws (VBS) system in lower cervical spine.

METHODS

Sixteen fresh cervical specimens were collected and dissected into 32 different units (functional spinal unit, FSU), 8 units in C3,4, C4,5, C5,6 and C6,7 each. The subjects were randomly divided into group A and B. The anterior transpedicular screw-plate system and anterior vertebral body screw-plate system were implanted separately in group A and B. Then, the maximum axial pull out strength was tested and compared between two fixation system.

RESULTS

Maximum pull out strength was (604.68 +/- 48.76) N in group A and (488.24 +/- 32.42) N in group B, and there was significant difference between two groups (t = 2.147, P < 0.05). There was no statistically significant difference in all FSU between anterior transpedicular screws system and vertebral body screws system (F(A) = 2.27, F(B) = 2.05, P > 0.05).

CONCLUSION

The pull out strength of anterior transpedicular screws system is better than vertebral body screws system, and the anterior transpedicular screws has the biomechanical feasibility in clinic.

[Treatment of flexion-distraction thoracolumbar fractures by postural reduction with instrumental reduction]

OBJECTIVE

To study the curative effect of postural reduction with instrumental reduction in treatment of flexion-distraction thoracolumbar fractures.

METHODS

A retrospective study was performed on 43 patients with single thoracolumbar flexion-distraction fractures admitted from August 2009 to August 2011, included 28 males and 15 females with an average age of 44 years old (34 to 56 years old). All patients were treated with postural reduction with instrumental reduction. The kyphosis (Cobb angle) recovery of injured vertebral height and complication were analyzed. The visual analogue scale(VAS) and com-plications were followed up and recorded.

RESULTS

There was no difference in recovery of injured vertebral posterior height among preoperative, 1 week and 1 year after operation (P > 0.05). There were significantly difference in kyphosis (Cobb angle) and recovery of injured vertebral anterior height between preoperative and postoperative at 1 week (P < 0.05). There was no difference in kyphosis (Cobb angle) and recovery of injured vertebral anterior height between 1 week and 1 year after operation (P > 0.05). VAS significantly improved from preoperative (7.2 +/- 1.2) to (0.8 +/- 0.7) at 1 year after operation (t = 18.47, P < 0.001).

CONCLUSION

Postural reduction with instrumental reduction is effective for thoracolumbar flexion-distraction fractures and it is beneficial to the recovery of vertebral height and saggital alignment.

[Case-control study on injured vertebra pedicle instrumentation and injured vertebra bone grafting for the treatment of thoracolumbar fractures]

OBJECTIVE

To compare the clinical effects of injured vertebra pedicle instrumentation and injured vertebra bone grafting in treating thoracolumbar fractures.

METHODS

A retrospective study was performed on 48 patients with single thoracolumbar fractures (type A3) from August 2008 to August 2010. Twenty-four patients were treated with injured vertebra pedicle instrumentation (group A) and 24 were treated with injured vertebra bone grafting (group B). There were 14 males and 10 females with an average age of (44.0 +/- 7.4) years old (34 to 56) in group A and there were 13 males and 11 females with an average age of (42.5 +/- 7.1) years(ranged, 31 to 54) in group B. Operation time, volume of blood loss, complications and the relative parameter of imageology were compared between two groups.

RESULTS

There was no significant difference in gender,age, position of injury, volume of blood loss between two groups. Operation time of group A was shorter than that of group B. Cobb angle and injured vertebral height obviously improved at the immediately postoperatively between two groups; there was no significant difference in group A between the immediately and three months postoperatively, but there was significant difference in group B; there was no significant difference between three months and one year postoperatively in two groups. The failure rate of group B was significantly higher than that of group A.

CONCLUSION

Pedicle screw fixation in the injured vertebrae has advantage of short operation time,can obtain satisfactory effects and is better than injured vertebra bone grafting in maintaining the reduction in treating single thoracolumbar fractures.

[Progress on cervical anterior transpedicular screw fixators for lower cervical vertebrae]

Compared with the traditional anterior and posterior operation,anterior transpedicular screw fixation (ATPS) has many advantages of hiomechanics, relative safety. Both problems of decompression and reconstruction can be resolved only through an anterior approach. A rather peculiar anatomic channel was used in ATPS, but no special tools was used in system supporting for anterior pedicle screw to place,so the indications of ATPS of lower cervical vertebrae is relatively narrow,it cannot replace of traditional anterior and posterior surgery. Problems of accurately inserting screws and the development of internal fixation device about ATPS is a hot spot of current research and a future direction. In recent years,many scholars have systematically studied the technique, and applied it in clinic gradually and achieved good effects. In order to improve the level of application,recent articles were analyzed retrospectively in this paper,and the studies of anatomy,biomechanical and clinical application of ATPS were reviewed.

Somatometric measurements, and clinical chemistry and hematology parameters in Tibetan macaque (Macaca thibetana)

BACKGROUND

Limited physiological data for Tibetan macaques are available at present. This study will provide more rationale for evaluating this species.

METHODS

Thirty-seven Tibetan macaques (15 males and 22 females) were used in this study. Somatometric measurements, clinical chemistry and hematology parameters, insulin, and C-peptide were analyzed.

RESULTS

Females had higher values of waist and waist hip ratio (WHR) than males in somatometric measurements. There were no significant differences between the two genders in hematology. Significant differences between males and females were only found for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in biochemistry testing. In addition, females had higher fasting insulin and C-peptide than males. There was a strongly positive correlation between age and some somatometric parameters.

CONCLUSIONS

These physiological data will provide veterinarians and researchers with baseline values to evaluate experimental results using Tibetan macaques.

[Radiological studies on the best entry point and trajectory of anterior cervical pedicle screw in the lower cervical spine]

OBJECTIVE

To explore the best entry point and trajectory of anterior cervical screw in the cervical screw by radiological studies, and provide reference for clincal application.

METHODS

From January 2008 to December 2010,50 patients were scanned by cervical CT and confirmed no obvious defect of lower cervical spine. Of them, 27 cases were males and 23 were females, ranged the age from 38 to 83 years ( mean 58.5 years). On horizontal axis, the camber angle of C3-C7 anterior lower cervical pedicle of vertebral arch axis (alpha) and distance between (axial length, AL) of anterior cervical pedicle axial line was measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch intersert into vertebral were recorded. On sagittal view, the head or tail angle (beta) and length (sagittal length, SL) of anterior cervical pedicle axial line was also measured from C3 to C7. Vertebral were divided into four areas, and from measured side of pedicle of vertebral began to record, orderly 1 to 4, the area of pedicle vertebral arch arch intersert into vertebral were recorded. The above data were statistically analyzed to find the best entry point and trajectory of anterior cervical screw in the cervical screw and insert pedicle screw.

RESULTS

The lateral angle of lower cervical spine was 38 degrees to 45 degrees on transverse plane, C3 to C5 increasing gradually, C5 to C7 decreasing. On sagittal view, C3,C4 pedicle were head tulting, C5 were basic level, C6,C7 were tail. C3 to C5 decreasing gradually, C5 to C7 increasing gradually. C3 to C7 in AL and SL increased gradually. On horizontal axis, the intersection of C3,C4 and C5 were in the second area, the number of C6 in the second and third area were the same, but C7 were in the third area. The intersection in the first and forth area were less. On sagittal view,the intersection of C3,C4 and C5 were in the first area,the number of C6 in third and forth area were less. Six pedicle screws of 3 cases were insert into lower cervical spine, and obtained good effects, no complications occurred.

CONCLUSION

The best entry point of C3,C4 and C5 were located in the center line and slightly to opposite vertebral body side and upper 1/4 area; C7 were located the vertebral body side and upper 2/4 area; C6 were located between them. The best insertion point were extraversion 38 degrees to 45 degrees, C3 to C5 increased graduallly, C5 to C7 decreased on horizontal axis; On sagittal view, C3,C4 for head 5 degrees to 10 degrees, C5 were basic level, C6,C7 for tail 5 degrees to 10 degrees. The anterior cervical pedicle screw for lower cervial spine is a good and feasible internal fixation.

Field assessment of Bt cry1Ah corn pollen on the survival, development and behavior of Apis mellifera ligustica

Honeybees may be exposed to insecticidal proteins from transgenic plants via pollen. An assessment of the impact of such exposures on the honeybee is an essential part of the risk assessment process for transgenic Bacillus thuringiensis corn. A field trial was conducted to evaluate the effect of transgenic Bt cry1Ah corn on the honeybee Apis mellifera ligustica. Colonies of honeybees were moved to Bt or non-Bt corn fields during anthesis and then sampled to record their survival, development and behavior. No differences in immature stages, worker survival, bee body weight, hypopharyngeal gland weight, colony performance, foraging activity or olfactory learning abilities were detected between colonies that were placed in non-Bt corn fields and those placed in Bt corn fields. We conclude that cry1Ah corn carries no risk for the survival, development, colony performance or behavior of the honeybee A. mellifera ligustica.

Biomechanical comparison of cervical transfacet pedicle screws versus pedicle screws

BACKGROUND

Transfacet pedicle screws provide another alternative for standard pedicle screw placement for plate fixation in the lumbar spine. However, few studies looking at transfacet pedicle screw fixation in the cervical spine are available. Therefore, cervical transfacet pedicle screw fixation and standard pedicle screw fixation techniques were biomechanically compared in this study.

METHODS

Ten fresh human cadaveric cervical spines were harvested. On one side, transfacet pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels. On the other side, pedicle screws were placed at the C3, C5, and C7 levels. The screw insertion technique at each level was randomized for right or left. The starting point for the transfacet pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees toward the midline in the axial plane. Screws were placed from the inferior articular process, across the facet complex and the pedicle into the body of the caudal vertebra. The entry point for the pedicle screw was located at the midpoint of the superolateral quadrant of the lateral mass, and the direction of the screw was about 45 degrees toward the midline in the axial plane and toward the upper third of the vertebral body in the sagittal plane. After screw placement we performed axial pullout testing.

RESULTS

All the cervical transfacet pedicle screws and the pedicle screws were inserted successfully. The mean pullout strength for the transfacet pedicle screws was 694 N, while for the pedicle screws 670 N (P=0.013). In all but six instances (10%), the pedicle screw pullout values exceeded the values for the transfacet pedicle screws; this occurred three times at the C3/C4 level, twice at the C5/C6 level and once at the C7/T1 level. The greatest pullout strength difference at a single level was observed at the C5/C6 level, with a mean difference of 38 N (t=-1.557, P=0.154). The C7/T1 level had a mean difference of 26 N and the C3/C4 level had a mean difference of 14 N.

CONCLUSIONS

Cervical transfacet pedicle screws exhibited higher pullout strength than pedicle screws. Posterior transfacet pedicle screw fixation in the cervical spine may afford an alternative to standard screw placement for plate fixation and cervical stabilization.

[All pedicle screws technique applied to the treatment of idiopathic scoliosis]

OBJECTIVE

To Analyze the therapeutic efficacy of all pedicle screws technique applied to the treatment of idiopathic scoliosis and evaluate its safety.

METHODS

From June 2002 to October 2005, 56 patients with idiopathic scoliosis were treated with all pedicle screws technique, including 11 males and 45 females, ranging in age from 8 to 22 years. According to Lenke classification, 29 patients were Type 1, 6 patients were Type 2, 8 patients were Type 3, 2 patients were Type 4, 8 patients were Type 5, and 3 patients were Type 6. Cobb angles ranged from 45 degrees to 85 degrees (mean 62.45 degrees).

RESULTS

The mean operation time was 3 hours and 20 minutes, and the average amount of bleeding was 600 ml. There were 425 pedicle screws inserted including 244 in thoracic, and 181 in lumbar, the positions of which were evaluated by CT. Nine screws were inserted with perforating through the medial wall of the pedicles. All the patients were followed up for 5 to 40 months (mean 22.5 months). The mean Cobb angle was corrected from 62 degrees preoperatively to 18 degrees postoperatively,and the average correction rate was 72.5%. No spinal nerves injury was found after operation, and superficial infection occurred in 2 patients but recovered after dressing change. All the patients got satisfactory spinal fusion and remained partly spinal mobility with fewer complications.

CONCLUSION

The application of all pedicles screws technique with familar with pedicular anatomy of scoliosis by imaging examination could gain a satisfactory effect of correction with less complications.

[A static mechanical comparison between two transarticular internal fixation techniques in the lower cervical spine]

OBJECTIVE

To compare static mechanical difference between two transarticular internal fixation techniques in the lower cervical spine.

METHODS

Ten fresh human cadaveric cervical spines were harvested. On one side, transarticular pedicle screws were placed at the C3-4, C5-6, and C7-T1 levels, and transarticular screws were placed on the other side. The screw insertion technique at each level was randomized for right or left. The starting point for transarticular pedicle screw insertion was located at the midpoint of the inferolateral quadrant of the lateral mass and the direction of the screw was about 50 degrees caudally in the sagittal plane and about 45 degrees medially in the axial plane, and the starting point for transarticular screw insertion was 1 mm medial to the midpoint of the lateral mass, aiming in a 15 - 20 degrees caudally and 35 - 40 degrees lateral position. After screw placement, each set of vertebral bodies were mounted in a custom jig for axial pullout testing using a servohydraulic testing machine. The load-displacement curves were obtained for each screw pullout.

RESULTS

The mean pullout strength for the transarticular pedicle screws was 668 N. This compares with 414 N for the transarticular screws (P < 0.05), but there was not significant difference statistically between different cervical levels (P > 0.05).

CONCLUSION

The static mechanical strength of transarticular pedicle screws is superior to the transarticular screws, and the transarticular pedicle screw fixation has the biomechanical feasibility of clinical application.

Mast cell density and IL-8 expression in nonlesional and lesional psoriatic skin

BACKGROUND

An important cellular aberration at sites of psoriatic inflammation is an increase in the number of dermal mast cells. Being multifactorial immune effector cells, it is believed that mast cells play an essential role in perpetuating the inflammatory process of psoriasis. However, factors responsible for the infiltration and accumulation of mast cells in psoriatic lesions are largely unknown. Recent studies have demonstrated that Interleukin-8 (IL-8) exerts strong chemotactic effects on mast cells in vitro. Overexpression of IL-8 has also been reported in psoriatic lesions. In this study, we have found a correlation between the expression of IL-8 and dermal mast cell density in lesional psoriatic skin as compared to nonlesional psoriatic skin.

METHODS

Four-mm punch biopsies were taken from 14 psoriatic patients and eight healthy volunteers. Using immunohistochemical techniques, 8 microm sections of lesional psoriatic, nonlesional psoriatic, and normal control samples were evaluated for dermal mast cell density and the density of IL-8 expressing keratinocytes.

RESULTS

It was found that dermal mast cell density in lesional psoriatic, nonlesional psoriatic, and normal skin was 105.4 +/- 71.2, 42.3 +/- 30.1, and 47.5 +/- 32.5 mast cells/mm(2), respectively. IL-8+ keratinocyte density in lesional psoriatic, non lesional psoriatic, and normal skin was 171.5 +/- 67.1, 25.4 +/- 14.9 and 20.6 +/- 8.7 IL-8+ Keratinocytes/mm(2), respectively.

CONCLUSIONS

The results of this study suggest that increased levels of IL-8 in the keratinocytes of psoriatic plaques play a contributing role in the migration of mast cells to lesion sites.

Cellular localization of fractalkine at sites of inflammation: antigen-presenting cells in psoriasis express high levels of fractalkine

BACKGROUND

Chemokines play a key role in cell trafficking at sites of inflammation. The fractalkine CX3C chemokine is unique in several aspects. Fractalkine is expressed on activated endothelial cells and exists in two forms, either membrane anchored or in a soluble form. The soluble form is a potent chemotactic agent for T cells/monocytes and the anchored form functions as an adhesion molecule. In view of these specific functions fractalkine is capable of controlling the key regulatory mechanisms of cell trafficking at sites of inflammation.

OBJECTIVES

Little is known about the significance of this important molecule in inflammatory diseases. We undertook this study to elucidate the role of fractalkine in inflammatory diseases of the skin.

METHODS

We used a polyclonal antifractalkine antibody (immunoperoxidase and immunofluorescence stainings) in cryosections obtained from tissues of normal skin and that of selected cutaneous inflammatory diseases (psoriasis, lichen planus, eczema).

RESULTS

Increased expression of fractalkine was observed in the dermal blood vessels of lichen planus, eczema and psoriasis tissues. The most striking finding was that the dermal dendrocytes in the papillary dermis of psoriasis tissues expressed high levels of fractalkine. Compared with 186.64 +/- 51.69 fractalkine positive dermal dendrocytes per mm2 of the upper dermis of psoriatic tissue, the number of positive cells in lichen planus, eczema, and normal skin were 17.29 +/- 12.50, 12.50 +/- 6.75 and 5.93 +/- 3.53, respectively. We also performed double label immunofluorescence staining with nerve growth factor receptor (NGF-R) antibody and fractalkine antibody. NGF-R-positive terminal cutaneous nerves were in close contact with the fractalkine-positive dermal dendrocytes in psoriatic lesions.

CONCLUSIONS

The results of this study confirm that fractalkine is upregulated at sites of inflammation. Thus, it is likely that this molecule plays a key part in cell trafficking. An increased expression of fractalkine at the dermal papillae provides a plausible explanation for the migration and accumulation of T cells at these sites in psoriasis. Earlier studies have reported an increased number of dermal dendrocytes in psoriatic tissue; however, the functional role of these cells in the pathogenesis of psoriasis is largely unknown. Expression of fractalkine on the surface of dermal dendrocytes suggests an active role for these cells in localization and activation of lesional T cells.

[Study on modulation effect of qi regulating and blood activating drugs on mechanism of immunity and hemorrheology in stressed rats]

OBJECTIVE

To explore the modulation effect of Chinese herbal medicines for Qi regulating and blood activating (QRBA) on mechanism of immunity and hemorrheology in stressed rats.

METHODS

The influence of QRBA on plasma noradrenaline (NA), proliferation of splenic cells and hemorrheologic properties were observed in stressed rats.

RESULTS

The Chinese herbal medicines for soothing Liver to regulate Qi, activating blood circulation to remove stasis and QRBA drugs could antagonize in various degrees the changes caused by stress. Among them QRBA drugs was the best, it could reduce the level of plasma NA (P < 0.01), modulate the blood hyperviscosity induced by exogenous NA (P < 0.05) and enhance proliferation of splenic cells (P < 0.01) in rats.

CONCLUSION

QRBA drugs strengthen immune function and restore hemorrheologic properties by reducing NA content in organism.

Upregulation of RANTES in psoriatic keratinocytes: a possible pathogenic mechanism for psoriasis

Intraepidermal collections of neutrophils and lymphocytes are unique features of the inflammatory reaction of psoriasis. Migration of leukocytes from dermis to the epidermis suggests a role for chemotactic agent(s). In recent years, increased levels of chemokines such as IL-8 , GRO-a and MCP-1 have been reported in the keratinocytes of psoriatic tissue. IL-8 and GRO-alpha belong to a subfamily (C x C) class and MCP-1 is a beta chemokine. In this study, we investigated RANTES, which is a beta chemokine (C-C class); RANTES has been found to be associated with various cell-mediated hypersensitive disorders. We obtained eight skin biopsies from chronic psoriatic plaques, and five biopsies each from non-lesional psoriatic skin, lichen planus, eczematous dermatitis and skin from healthy controls. Snap-frozen samples were cut into 7 microm cryosections and stained with 6 mg/ml of monoclonal anti-RANTES mouse IgG (DNAX, Palo Alto, CA). Standard immunohistochemistry techniques were applied. RANTES was detected only in the keratinocytes. The number of keratinocytes in per mm2 of epidermis stained for RANTES were 116.79+/-98.42 in psoriatic tissues compared to 32.00+/-46.05 (p<0.05), 6.39+/-3.59 (p<0.01), 2.64 +/-1.15 (p<0.01) and 3.53+/-5.26 (p<0.01), respectively, in the non-lesional, lichen planus, eczematous lesions and normal skin. This is the first study to report that the keratinocytes of psoriatic tissue express high levels of RANTES compared to the controls. IL-8 and related molecules (C x C class) are predominantly chemotactic for neutrophils and MCP-1 is a strong chemotactic factor for monocytes. In contrast, RANTES is chemotactic for memory T cells and activated naive T cells. Increased amounts of RANTES as reported here provide an explanation for migration of the activated T cells to the epidermis of the psoriatic lesions. In addition, RANTES activates T cells. These results suggest that RANTES may have a significant role in the inflammatory process of psoriasis. Our findings further substantiate a regulatory role for keratinocytes in the inflammatory process of psoriasis.

Double-labeled immunofluorescence study of cutaneous nerves in psoriasis

BACKGROUND AND OBJECTIVE

In recent years, many reports have suggested an active role of neuropeptides in the pathogenesis of psoriasis. Increased numbers of neuropeptide-containing nerves positive for substance P (SP), vasoactive intestinal polypeptide (VIP), and calcium gene-related peptide (CGRP) have been reported in psoriatic tissue. As psoriatic epidermis has a larger mass/volume, however, it is expected to have more nerves and a higher number of neuropeptergic fibers. Therefore, instead of demonstrating a larger number of neuropeptergic fibers, a more significant study is to investigate whether the neuropeptergic fibers are denser in psoriatic tissue. In this study, we applied a double labeled immunofluorescence technique. This method allows the identification of the total number of nerve fibers and the number of nerves positive for specific neuropeptides.

MATERIALS AND METHODS

We obtained biopsies from nine lesional and seven non-lesional psoriatic skins and six normal controls. Biopsies were snap frozen and then cut into 14 microm cryosections. The tissues were first treated with anti-microtubule associated protein (MAP)2 antibody to stain the nerves. This was followed by a second set of stainings for SP, VIP, and CGRP. Primary antibodies were used in dilutions of 1:200 for anti-MAP2, 1:200 for anti-SP, 1:800 for anti-VIP, and 1:400 for anti-CGRP.

RESULTS

We found that the percentage of SP-positive fibers was twofold greater and the percentage of CGRP-positive fibers was 2.5 times greater in the psoriatic epidermis than in the epidermis of normal skin. Psoriatic epidermis had 30.1 +/- 3.9% SP-positive nerve fibers compared with 15.7 +/- 3.7% in the normal control. The corresponding values for CGRP-positive nerve fibers were 30.1 +/- 3.9% and 12.0 +/- 4.2%.

CONCLUSIONS

The results of our study suggest that SP- and CGRP-containing neuropeptide nerve fibers are more dense in the psoriatic epidermis. Both SP and CGRP are chemotactic to neutrophils and mitogenic to keratinocytes and endothelial cells. In addition, SP activates T lymphocytes and induces adhesion molecules on the endothelial cells. Our observations suggest that neuropeptides may play a significant role in the inflammatory and proliferative process of psoriasis.

Psoriatic keratinocytes express high levels of nerve growth factor

Many investigators have reported proliferation of terminal cutaneous nerves and upregulation of various neuropeptides (substance P, vasoactive intestinal polypeptide, calcitonin gene-related peptide) in psoriatic lesions. Nerve growth factor promotes growth of nerves and causes upregulation of neuropeptides like substance P and calcitonin gene-related peptide. In this study we investigated the expression of nerve growth factor in psoriatic lesions, non-lesional psoriatic skin, lichen planus and normal control skin. Immunoperoxidase staining was applied on cryosections prepared from snap-frozen biopsy specimens. The primary antibody used was a polyclonal anti-NGF-beta antibody. Nerve growth factor was detected only in the keratinocytes. In psoriatic tissue the number of keratinocytes per square millimeter of epidermis positive for nerve growth factor was 84.7 +/- 46.3 compared to 44.8 +/- 29.9, 18.9 +/- 11.8 and 7.5 +/- 16.9, respectively, in non-lesional psoriatic skin, normal skin and lichen planus. Increased expression of nerve growth factor substantiates larger numbers of terminal cutaneous nerves and upregulations of substance P and calcitonin gene-related peptide in psoriatic lesions. In addition, nerve growth factor is mitogenic to keratinocytes, activates T-lymphocytes and can induce migration of inflammatory cellular infiltrates, histological features characteristic of psoriasis.

[Expression and biochemical characterization of human G6PD gene 1376 and 1388 mutation in G6PD-deficient Escherichia coli]

Nine types of human G6PD gene mutated at the positions of nt 1376 and nt 1388 by site-directed mutagenesis were transformed into the strain of G6PD dificent E. coli HB 351(DE3). The mutated gene was expressed successfully and the enzyme kinetic studies undertaken according to WHO standardization. The results showed that the arginine residues at the positions of 459 and 463 of G6PD gene play an important role in maintaining activity of the enzyme. The amino acid structure, polarity, and electronic property may be responsible for it. The arginine residues at the positions of 459 and 463 are also important for the enzyme-NADP+ binding, but it was not interfered by the lysine-arginine substitution. By inducing a non-sense mutation, it was further demonstrated that the amino acids residueds behind the position of 459 were extremely significant for G6PD activity.

Intraepidermal nerve fiber expression of calcitonin gene-related peptide, vasoactive intestinal peptide and substance P in psoriasis

In order to evaluate more fully the role of neuropeptides in the pathogenesis of psoriasis, skin biopsies were obtained from 36 patients with psoriasis to identify substance P (SP), vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP). Lesional and nonlesional skin was examined from these biopsies and the results compared with those from biopsies taken from patients with a variety of other inflammatory dermatoses, including lichen planus, lichen simplex chronicus, spongiotic dermatitis, and seborrheic dermatitis. Also studied was a series of nine biopsies taken from patients with no known skin disorders. We found an increase in the number of SP-positive nerve fibers within the epidermis in biopsies from lesional skin of psoriasis patients (8.4 nerves per 3-mm biopsy) compared with nonlesional psoriatic skin (2.6 nerves per 3-mm biopsy) and normal skin (2.0 nerves per 3 mm biopsy). Other inflammatory disorders also demonstrated fewer SP-positive nerves than lesional psoriatic skin; lichen planus (0 nerves per 3 mm biopsy) and lichen simplex chronicus (1.3 nerves per 3 mm biopsy). The difference in SP-positive nerve expression between lesional psoriatic skin and the group comprising nonlesional skin, normal skin, lichen planus, and lichen simplex chronicus attained statistical significance (P < 0.013). SP-positive intraepidermal nerve fibers in lesional psoriatic specimens were fewer than in spongiotic dermatitis (17.4 nerves per 3 mm biopsy). There was no significant difference in numbers of VIP- or CGRP-immunopositive intraepidermal nerve fibers between psoriatic skin and the group comprising all other material tested. However, in five patients with psoriasis, there was a marked increase in the expression of intraepidermal CGRP (up to 10.7 nerves per 3-mm biopsy) and VIP (up to 8.3 nerves per 3-mm biopsy) which was not observed in control groups. These findings suggest that neuropeptides SP, CGRP, and VIP play a role in the pathogenesis of psoriasis.

Corporate values as related to occupation, gender, age, and company size

A mail survey was used to study the perceived importance of 15 corporate values among advertising personnel, CPAs, and business school professors. Excellent customer service, ethical behavior, and product quality were perceived as highly important by all groups. Political activity and contribution to the community were seen as relatively unimportant. There was general agreement that it was more important to make a fair profit than to maximize profits. A number of corporate values were significantly related to occupational group, gender, age, and company size.

[Mechanism of tonifying kidney and removing blood stasis recipe in modulation of immune senescence]

This experiment was from 3 aspects to study the relationship between modulating immune senescence and the improvement of free radical metabolism by the recipe of Baweidankun decoction (BWDKD). The results showed that the production of IL-2 decreased, the content of LPO increased and the activity of catalase (CAT) declined in old mice. After medication of BWDKD the above-mentioned indices were modulated. The ozone inhaled mice revealed similar changes of aging in the above indices. After BWDKD administration, the content of LPO decreased, meanwhile, the activity of CAT and IL-2 were strengthened and showed linear correlation. It was discovered that the production of IL-2 decreased significantly after adding H2O2 into the culture of splenic lymphocytes, but when BWDKD was added simultaneously, the IL-2 production was restored to the level of control group, in which no H2O2 was added. The results suggested that the modulating effect of BWDKD on immune senescence was closely related with the improvement of free radical metabolism, and it provided a partial evidence for the viewpoint of "Vitality deficiency with blood stasis is the principal mechanism of senescence".

Liver cirrhosis deaths within occupations and industries in the California occupational mortality study

Mortality rates were drawn from the California Occupational Mortality Study (COMS) to analyze liver cirrhosis deaths within occupations and industries from 1979 to 1981. Age-adjusted Standardized Mortality Rates (SMRs) were made available by the State of California for separate analyses of women, men, blacks and whites. Rankings of occupations with narrow confidence intervals were strikingly similar for blacks and whites. Within occupations, the highest female SMRs were for waitresses, telephone operators, cosmetologists, dress makers, hospital orderlies, textile workers, and laborers. The lowest female SMRs were for skilled crafts workers and teachers. High male occupations included water transportation workers, bartenders, loggers, laborers, roofers, construction workers, farm workers, iron workers, and painters. Low male occupations included teachers, physicians and dentists, managers, factory supervisors, business sales workers, heavy equipment operators, and other professionals. High female industries included eating and drinking places, laundry/dry cleaning, nursing and personal care facilities, aerospace, beauty shops, and entertainment. Low female industries included wholesale trades and education. High male industries included water transportation, military, guard services, eating and drinking places, iron and steel mills, and railroads. Low male industries included research/engineering labs, education, and computer manufacturing. This study was descriptive. It remains unknown whether certain jobs cause excessive drinking and cirrhosis, or whether people who are prone to develop cirrhosis select certain jobs.

A synergetic theory of quadrupedal gaits and gait transitions

We present a theoretical analysis of the patterns of interlimb co-ordination in the gaits of quadrupedal locomotion. Introducing as collective variables a set of relative phases that describe the co-ordination patterns, we classify gaits by their symmetry properties, which can be expressed as invariances under groups of transformations. We define dynamics of the collective variables, on which we impose symmetry restrictions. The stable observable gait patterns correspond to atractors of these dynamics. A non-trivial consequence of this theoretical viewpoint is that gait transitions can take the form of non-equilibrium phase transitions that are accompanied by loss of stability. We show how various types of such phase transitions involving hysteresis, slowing down and fluctuation enhancement can occur. Also the difference between smooth and abrupt transitions is given theoretical foundation. While existing experimental evidence is consistent with the theory developed here, we propose new experimental measures that can serve to test the present theoretical framework. Finally, the influence of underlying symmetries of the dynamics on the nature of the gait patterns and their stability is analyzed. For example, breaking of a front-hind symmetry can lead to a change from absolute to relative co-ordination in the sense of von Holst (1939, Ergebnisse der Physiologie 42, 228). Also, differential stability of straight and reverse gaits results from thus lowering the symmetry.