[The anatomical feasibility analysis of posterior laminar screw fixation techniques in upper thoracic vertebrae].

OBJECTIVE: To investigate the anatomical feasibility and the technique of T(1)-T(3) crossing laminar screws fixation in the adult population. METHODS: There were 33 dry upper thoracic vertebras specimen which included respectively T(1), T(2), T(3) were studied. Spinous process height (Hs), bilateral laminar height (H), length of superior laminar screws (Ls), length of inferior laminar screws (Li), bilateral thickness of laminar (TL) and crossing angle the laminar (A) were measured. On the basis of modified Kretze's technique, T(1) crossing laminar screws implantation was performed under visual control. The crossing laminar screws position were evaluated by X-ray and visualizing. RESULTS: The mean Hs of T(1) was the highest which was (15.7 ± 1.6) mm; the mean H of T(3) was the highest which was (18.7 ± 1.1) mm; the TL and A of T(1) were (6.3 ± 0.9) mm and 101.8° ± 4.5°, that of T(2) were (6.9 ± 1.0) mm and 101.9° ± 4.3°, that of T(3) were (6.5 ± 0.9) mm and 102.9° ± 4.4°, respectively. There were no significant differences between the values of the H and TL on left and right sides (P > 0.05). The Ls of T(1), T(2), T(3) were shorter than Li of that [(31.7 ± 2.4) mm vs. (37.3 ± 2.3) mm, (25.8 ± 2.2) mm vs. (32.3 ± 2.7) mm, (25.3 ± 2.7) mm vs. (31.2 ± 2.9) mm, respectively]. There was significant statistically difference between the values of the Ls and Li on the same vertebra (P < 0.05). The mean TL of T(2) was the thickest, which was significant statistically thicker than that of T(1) (t = 8.876, P < 0.01), which was not significant statistically thicker than that of T(3) (t = 1.919, P > 0.05). The T(1) crossing laminar screws were successfully placed, without impingement of the spinal canal. CONCLUSIONS: It is feasible to place T(1), T(2), T(3) crossing laminar screws in most people. This study provides anatomic guidelines to allow for accurate screw selection and insertion.

[Effects of combined application of maize- and horsebean straws on the straws decomposition and soil nutrient contents].

A laboratory incubation experiment was conducted to study the straw decomposition and soil nutrient contents after single and combined applications of maize- and horsebean straws. With the single application of maize straw, the mineralization rates of the straw and soil organic C were lower, and the immobilization of soil mineral N sustained longest. Combined application of maize- and horsebean straws promoted the mineralization of the straws organic C and soil immobilized N. Both single and combined application of the straws increased the contents of soil microbial biomass C and N significantly. It was suggested that a combined application of gramineous and leguminous straws could promote the straws decomposition and harmonize the soil nutrient supply.

[Decomposition of different plant litters in Loess Plateau of Northwest China].

Taking the litters of species Hippophae rhamnoides, Medicago sativa, Populus simonii, Robinia pseudoacaci, Salix psammophila, and Stipa bungeana in the Loess Plateau of Northeast China as test objects, and by using mesh bags, this paper studied the dynamic changes of the litters mass, carbon, and nitrogen during decomposition after buried in the field in semiarid region. The litters buried were from one, two, or three of the plant species, and mixed thoroughly with equal proportion of masses. During decomposition, the mass loss rate, total carbon and nitrogen release rates, and total soluble carbon and nitrogen contents of different litters were higher at the early than at the later decomposition stage. After 412 d decomposition, the average mass loss rate of the litters was in the order of mixed litters of three plant species > mixed litters of two plant species > one plant species litter. By the end of this experiment, the average release rates of the litter total carbon and nitrogen ranked as one plant species litter > mixed litters of two plant species > mixed litters of three plant species, the litter soluble organic carbon content was mixed litters of two plant species > mixed litters of three plant species > one plant species litter, while the litter soluble total nitrogen content was mixed litters of three plant species > mixed litters of two plant species > one plant species litter. Correlation analysis showed that the litter mass loss rate had definite correlation with the litter soluble organic matter, especially soluble organic carbon. From the viewpoint of mass loss rate, the mixture of the litters of P. simonii, H. rhamnoide, and M. sativa was the optimum. It was suggested that in the process of returning farmland into forestland and grassland in the gully and valley region of Loess Plateau, it would be required to rationally increase plant species diversity to improve soil fertility.

[Contents and biodegradation of soluble organic carbon in different plant residues from the Loess Plateau].

Soluble organic carbon (SOC) in plant residues extracted by water or different extractants is an active component, and has important roles in carbon and nitrogen biogeochemical process in soil ecosystem. Reestablishing the vegetation on the Loess Plateau is changing the types and amounts of the plant residues into soil ecosystem. Therefore, our objective was to evaluate the contents and biodegradation of SOC of residues of different species from this region. Six species of plant residues were sampled from Shenmu, North of the Loess Plateau, and the contents of SOC in two sizes residues (2 mm and 1 cm length) was extracted with two extractants (distilled water and 0.01 mol x L(-1) CaCl2). And a 7-day incubation experiment (25 degrees C) was conducted to compare the biodegradability of SOC of the different plant residues. The contents of SOC in the different plant species ranged from 4.21 g x kg(-1) to 76.25 g x kg(-1), and the rates of SOC to total carbon (SOC/TC) of the plant residues were in range of 0.99% and 19.84%. The order about the average content of SOC and SOC/TC of the different plant species was trees > shrubs > grasses. After 7-day of incubation, rates of biodegradation of SOC in different plant residues ranged from 34. 7% to 75. 1% (averaged 56.3%). The proportion of complex structure SOC increased significantly in solution at the end of incubation, indicated the rapid biodegradation of labile composition in the residues.

[Effects of Huoxue Zhitong decoration on transmembrane protein I and II induced apoptosis of signal transmission of the epidural scar tissue].

OBJECTIVES: To study the effect of Houxue Zhitong decoration on the expression of the mitochondria-initiated apoptosis pathway and transmembrane protein I an II of the epidural scar tissue. METHODS: A total of 60 New Zealand rabbits (weight: 2.5-3.0 kg) were randomly divided into four groups, sham operation group (D, n=15), control group (B, n=14), sodium hyaluronate group (C, n=15), Houxue Zhitong decoration group (D, n=15). Except for group A, 1.0 cm x 1.0 cm dura mater uncovered area laminectomy was performed at I (4) and I(5), covered with 0.5 ml sodium hyaluronate in group C, covered with same amount of saline in group B and D. First 2 weeks after operation, animals in group D were lavaged with 2.5 ml/kg Houxue Zhitong decoction by one a day for 14 days. Five rabbits of each group selected randomly were killed in the 2,4,8 weeks after laminectomy. The specimens were prepared for determination of the expression of Fas and FasL, at scar tissue by semiquantitative reserve transcription-polymerase chain reaction (RT-PCR). The degree of scar adhesion was evaluated according by Rydell method. RESULTS: The adhesion area in group B was larger than of group C and D in the 4th and 8th week. However, the number of fibroblasts and inflammantory cells in group D was the least among the three groups in the 8th week. At 2, 4, 8 weeks after operation, as compared with group B the expression of Fas, FasL of group C and D were decreased (P < 0.05). Especially, at 2 weeks, as compared with group B the expression of this two cytokines of group D was significant decreased (P < 0.05), too. In group C and D the duramater adhesion was decreased (P < 0.05). The proliferation of fibroblast and fibroblastic function were inhibited (P < 0.05). CONCLUSION: Huoxue Zhitong is able to down-regulated the expression of Fas, FasL, which inhibited the proliferation of fibroblast, the fibroblastic function and the synthesis of extracellular matrix in the epidural scar tissue. It is an effective way of reducing peridural scar formation and prevent the failed back surgery syndrome.

[Effects of Huoxuezhitong recipe on the pathway of mitochondrial apoptosis and the expression of related gene in epidural scar tissue].

OBJECTIVE: To study the effect of Huoxuezhitong recipe on the pathway of mitochondrial apoptosis and the expression of related gene (Caspase-3, -9, Bax, Bcl-2) in epidural scar tissue. METHODS: A total of 60 New Zealand rabbits, ranging in weight from 2.5 to 3.0 kg, were randomly divided into sham operative group (group A), control group (group B), sodium hyaluronate group (group C), Huoxuezhitong recipe group (group D, included Danggui 20 g, Chishao 20 g, Honghua 20 g, Ruxiang 15 g, Myrrh 15 g etc.) with 15 rabbits in each group. Except for group A, L4,5 vertebral plate were resected leading to 1.0 cm x 1.0 cm dura mater exposed area, which were covered with 0.5 ml sodium hyaluronate in group C, covered with same amount of saline in group B and D. At 2 weeks after operation, the rabbits of group D were administered with Huoxuezhitong recipe (2.5 ml/kg, once a day, continuous 14 d). Five rabbits of each group were selected randomly and were killed at 2, 4 and 8 weeks after operation; and the expression of Caspase-3, -9, Bax, Bcl-2 in scar tissue were surveyed by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The results by RT-PCR showed significant different in expressions of Caspase-3, -9, Bax, Bcl-2 of group A and others groups at each period (P < 0.01). At 2, 4, 8 weeks after operation, compared with group B, the expressions of Caspase-3, -9, Bcl-2 in group C and D were decreased (P < 0.05), but the expression of Bax in group C and D were increased (P < 0.05). At 8 weeks after operation, the expressions of Caspase-3, -9, Bax, Bcl-2 in group D was significant decreased compared with group C (P < 0.05). CONCLUSION: Huoxuezhitong recipe can regulate the levels of expression of Caspase-3, -9, Bax, Bcl-2 mRNA and further induce the pathway of mitochondrial apoptosis, thereby, achieve the effect of prophylaxis for the proliferation and conglutination of epidural scar tissue.

[MRI finding of the lumbar foraminal stenosis and its clinical significance].

OBJECTIVE: To observe morphological changes of lumbar intervertebral foramen and pathologic changes around the nerve root and to explore the main evaluation index for lumbar foraminal stenosis (LPS) in parasaggital MRI finding. METHODS: From Jan. 2007 to Aug. 2009, MRI finding in 35 patients with the LPS that were confirmed by surgery was retrospectively analyzed. This group including 27 males, 8 females; aged from 35 to 82 years with the mean of 54.5 years; the course was from 4 months to 8 years with the mean of 32 months. At the same time compared with another group including 37 cases whose MRI finding of foramen were normal. To find out the differences between two groups in effective foraminal height, effective superior foraminal width, the effective ratio of nerve root cross-sectional area and foramen cross-sectional area by analyzing the parasaggital MRI finding of L4.5 or L5S1 foramen. To analyze the main factors that included LPS. RESULTS: Effective foraminal height and effective superior foraminal width in L(4,5) or L5S1 foramen in LPS group was smaller than that of control group (P < 0.01). The effective ratio in LPS group was larger than that of control group (P < 0.01). A variety of interacting factor were included LPS. Degeneration of the vertebral disk and hypertrophic ligamentum flavum were the main factors of soft tissue. Hypertrophy of the articular process and osteophyte on border of the vertebral body were the main factors of bone tissue. The edema and adhesion of nerve root with adjacent tissue were the main factors of nerve root. CONCLUSION: The compound factors of soft tissue, bone tissue and nerve root resulted in LPS. MRI can adequately demonstrate anatomic structure of the foramen and pathologic changes of LPS. Effective foraminal height, effective superior foraminal width and the effective ratio can regard as the main evaluation index for LPS in parasaggital MRI finding.

Treatment of lumbar and lumbosacral spinal tuberculosis with minimally invasive surgery.

OBJECTIVE: To evaluate the outcome of computed tomography (CT)-guided percutaneous puncture and local chemotherapy for tuberculosis (TB) of the lumbar or lumbosacral spine. METHODS: From January 2002 to August 2006, 49 patients with lumbar or lumbosacral spinal TB in whom conservative treatment had failed were treated by minimally invasive surgery. There were 21 female and 28 male patients. The mean age of the patients was 47 ± 18 years (range from 12 to 78 years). There were 40 cases with lumbar TB, and 9 with lumbosacral TB. From L(1) to S(1), the involved vertebral numbers were 8, 26, 19, 19, 21 and 10, respectively. In 3 patients the spinal TB involved a single vertebra, in 39 patients two, in 6 patients three and in only one case four vertebrae. According to the Frankel scale, three patients had grade E incomplete paralysis preoperatively. The outcome, after treatment by CT-guided percutaneous puncture and local chemotherapy, was retrospectively analyzed according to the preoperative and postoperative kyphotic angles and the Oswestry disability index (ODI). RESULTS: Forty-nine patients were followed up for from one year to 5 years and 8 months (average 35 months). All cases recovered, and there was no recurrence. Preoperatively, the kyphotic angle was 16.47°± 8.74°, and it had decreased to 13.35°± 8.02° by the final follow-up (t= 5.79, P < 0.001). The average ODI score had improved from 70.12 ± 22.24 to 12.72 ± 8.62 (t= 21.42, P < 0.001). CONCLUSION: The majority of cases of lumbar and lumbosacral spinal TB can achieve satisfactory results with minimally invasive surgery. Its clinical application is therefore strongly recommended.

[Soluble organic carbon in plant litters on Loess Plateau: content and biodegradability].

The litters of eight plant species from the Loess Plateau were cut into pieces with 2 mm and 1 cm in size, and extracted with distilled water and 0.01 mol x L(-1) CaCl2 to determine the soluble organic carbon (SOC) content. In the meantime, a 7-day indoor incubation test was conducted at (25 +/- 3) degrees C to investigate their biodegradability. The SOC content and the ratio of SOC to total carbon (SOC/TC) in the litters were 18.20-156.82 g x kg(-1) and 4.21%-32.84%, respectively. Shrub litter had a slightly higher SOC content than tree litter, while grass litter had the lowest SOC content. After 7-day incubation, the biodegradation rate of SOC in the plant litters ranged from 44.5% to 80.6% (62.9% on average), and decreased in the order of shrub > tree > grass. By the end of the incubation, the proportion of soluble organic matter in solution had a significant increasing trend, which was related to the rapid biodegradation of labile composition in the litters. The higher content and higher biodegradation rate of SOC in plant litters might play important roles in nutrient cycling and energy flow during the vegetation restoration on Loess Plateau.

[Progress of lumbar interspinous process spacer].

Lumbar interspinous process spacer, as a important aspect of dynamic stabilization system,through implant a spacer into interspinous process, which can limit the extension of the pathological segment, reserves the physiological activities basically, increases the volume of the spinal canal and intervertebral foramina, decreases the loading of the posterior of disc, and it doesn't affect the motion and the loading of the adjacent segment significantly. From the available documentary, the biomechanical and clinical results of various lumbar interspinous process spacers were optimistically. The purpose of this paper is to review these investigations in respect of lumbar interspinous process spacers.

[Comparison of penetration and obturation density using nickel-titanium and stainless-steel spreader in curved canals].

OBJECTIVE: To compare the initial penetration depth of nickel-titanium (NiTi) and stainless-steel (SS) spreader during lateral compaction and the quality of the seal in curved canals. METHODS: Forty extracted mandibular premolars with a single curved canal were divided into two groups: no more than 20 degrees and more than 20 degrees based on degree of curvature. All canals were instrumented using a rotary instrumentation technique. NiTi and SS spreaders were used to obturate the canals containing a master cone while the penetration depths were measured. Horizontal sections were cut in 2 and 4 mm from the apex and photographed under stereomicroscope. The percentage of gutta-percha-filled are (PGP) of cross-sections was measured using an image analysis program. RESULTS: In canals of more than 20 degrees, the penetration depths and PGP of 2 mm from the apex of NiTi spreaders were higher than SS spreader. In canals of no more than 20 degrees, there were no significant difference between them (P > 0.05). At 4 mm from the apex, there was no significant difference between two groups. CONCLUSION: NiTi spreaders has a higher penetrated depth and obturation density than SS spreaders in severed curved canals.