Asymmetric Cross-Coupling of Aldehydes with Diverse Carbonyl or Iminyl Compounds by Photoredox-Mediated Cobalt Catalysis.

The asymmetric cross-coupling of unsaturated bonds, hampered by their comparable polarity and reactivity, as well as the scarcity of efficient catalytic systems capable of diastereo- and enantiocontrol, presents a significant hurdle in organic synthesis. In this study, we introduce a highly adaptable photochemical cobalt catalysis framework that facilitates chemo- and stereoselective reductive cross-couplings between common aldehydes with a broad array of carbonyl and iminyl compounds, including N-acylhydrazones, aryl ketones, aldehydes, and α-keto esters. Our methodology hinges on a synergistic mechanism driven by photoredox-induced single-electron reduction and subsequent radical-radical coupling, all precisely guided by a chiral cobalt catalyst. Various optically enriched ß-amino alcohols and unsymmetrical 1,2-diol derivatives (80 examples) have been synthesized with good yields (up to 90% yield) and high stereoselectivities (up to >20:1 dr, 99% ee). Of particular note, this approach accomplishes unattainable photochemical asymmetric transformations of aldehydes with disparate carbonyl partners without reliance on any external photosensitizer, thereby further emphasizing its versatility and cost-efficiency.

Total Syntheses of Uncommon C30 Terpenoids: Chamaecydin and Isochamaecydin.

(-)-Chamaecydin and (-)-isochamaecydin, two uncommon C30 terpenoids comprising abietane-type diterpenes and thujane-type monoterpenes, were achieved from ß-pinene with (-)-sabinene in 18 and 20 steps, respectively. Key steps include a Claisen-Ireland rearrangement to establish the all-carbon quaternary center, a Rh catalyzed C-H bond insertion reaction to install a spiro-five-membered ring and a Lewis acid promoted cyclization of polyenes to construct the two six-membered rings.

Total Synthesis of Guajavadimer A via Lewis Acid-Catalyzed Cascade Double Hetero-Diels-Alder Reactions.

The first total synthesis of guajavadimer A, a dimeric caryophyllene-derived meroterpenoid featuring an unprecedented 4-9-6-6-6-9-4-fused ring system, is reported. Key to the approach is the construction of the pyrano[4,3,2-de]chromene core via a cascade of double hetero-Diels-Alder reactions. Practically, a 4-substituted-2,6-dihydroxybenzaldehyde dimethyl acetal serves as an effective surrogate for ortho-quinone methide, which is generated from the corresponding aldehyde and trimethyl orthoformate, with ß-caryophyllene undergoing cycloaddition to generate pyrano[4,3,2-de]chromene derivatives with excellent regioselectivity and stereoselectivity in one pot under mild conditions.

Risk factors of postoperative low back pain for low-grade isthmic spondylolisthesis: a retrospective study.

OBJECTIVE: To investigate the risk factors of postoperative low back pain (LBP) following posterior lumbar interbody fusion (PLIF) surgery for low-grade isthmic spondylolisthesis (IS). METHODS: This retrospective study enrolled patients with IS that underwent PLIF between January 2011 and January 2016. Demographic, clinical, surgical and radiological characteristics were analysed to determine associations between these characteristics and LBP as measured using a visual analogue scale (VAS) pain score. RESULTS: A total of 192 patients were enrolled in the study. The mean VAS pain score of LBP decreased significantly after surgery. The mean preoperative VAS pain score was significantly greater in patients with symptoms of ≤3 years duration compared with those with symptoms lasting >3 years. The postoperative VAS pain score was significantly lower in patients with grade 1 slippage compared with those with grade 2 slippage. There was a significant correlation between preoperative to postoperative change of VAS pain score and postoperative disc height (r = 0.99). CONCLUSION: PLIF significantly improved LBP in patients with low-grade IS, although patients still reported some postoperative LBP. The grade of slippage was a risk factor for postoperative LBP. Restoring the disc height appeared to improve LBP.

Development of nucleic acid isolation by non-silica-based nanoparticles and real-time PCR kit for edible vegetable oil traceability.

For efficient extraction of amplifiable DNA from edible vegetable oils, we developed a novel DNA extraction approach based on the non-silica-based dipolar nanocomposites. The nanoparticle comprises a hydrophilic polymethyl methacrylate core with abundant capillaries, hydrophilic vesicles decorated with molecules having DNA affinity and a coating hydrophobic polystyrene layer. The nanoparticles are soluble in oil, adsorb the DNA from the aqueous phase and gave a high DNA recovery ratio. All DNA extracts from fully refined vegetable oil soybean, peanut, rapeseed, and cottonseed oils, including their blends, were sufficiently pure to be amplified by real-time PCR targeting the chloroplast ribulose-1,5-bisphosphate gene (rbcL), therefore, the species of origin and their ratios in mixed vegetable oils blended from two or three oil-species could be determined. These results indicate that the novel DNA isolation and real-time PCR kit is a simple, sensitive and efficient tool for the species identification and traceability in refined vegetable oils.

Risk Factors of Postoperative Sacroiliac Joint Pain for Posterior Lumbar Surgery: ≥2-Year Follow-up Retrospective Study.

PURPOSE: A retrospective study was conducted to clarify the risk factors of postoperative sacroiliac joint pain (SIJP) for posterior open lumbar surgery. PATIENTS AND METHODS: A total of 472 patients who underwent posterior lumbar surgery between January 2011 and December 2014 were included in this analysis. We recorded basic characteristics, surgical characteristics, and SIJP information for each patient. RESULTS: The incidence of postoperative SIJP is 13.8% in our study. Comparison of the incidence of SIJP between diskectomy and posterior lumbar interbody fusion indicated that SIJP incidence tended to be higher in posterior lumbar interbody fusion patients (P = 0.029). Compared with the single-segment group, SIJP occurred more frequently in the multiple operative segments group (P = 0.025). Comparing the incidence of SIJP among different types of lumbar diseases, SIJP incidence is significantly higher in the lumbar stenosis group (P = 0035). CONCLUSION: Lumbar fusion surgery and multiple operative segments are interdependent risk factors for the postoperative SIJP. The incidence of postoperative SIJP also increases in patients with lumbar stenosis compared with lumbar disk herniation and lumbar spondylolisthesis.

Risk Factors of Postoperative Low Back Pain for Low-Grade Degenerative Spondylolisthesis: An At Least 2-Year Follow-Up Retrospective Study.

OBJECTIVE: A retrospective study was conducted to clarify the risk factors of postoperative low back pain (LBP) for low-grade degenerative spondylolisthesis. PATIENTS AND METHODS: A total of 239 patients who underwent posterior lumbar fusion between January 2011 and January 2015 were included in this analysis. We investigated patient characteristics, surgical characteristics, and radiographic characteristics. RESULTS: The mean visual analog scale (VAS) score of LBP decreased dramatically after the operation. The mean preoperative VAS score was greater in patients with severe lumbar multifidus (LM) intramuscular adipose tissue (IMAT). The postoperative VAS score was dramatically lower in patients with shorter symptom duration. Postoperative LBP disappeared more often in patients with shorter symptom duration. LBP VAS changing showed significant differences in different symptom duration groups and LM IMAT groups. CONCLUSIONS: LM IMAT and symptom duration were risk factors for postoperative LBP. Patients with severe LM IMAT reported more severe LBP before the operation. Postoperative LBP disappeared more often in patients with shorter symptom duration.

Risk Factors of Postoperative Low Back Pain for Lumbar Spine Disease.

PURPOSE: A retrospective study was conducted to clarify the risk factors of postoperative low back pain (LBP) for lumbar spine disease. PATIENTS AND METHODS: A total of 401 patients who underwent lumbar operation between January 2011 and December 2011 were included in this analysis. We investigated patient characteristics and surgical approaches and also compared the radiographic characteristics. RESULTS: The mean visual analogue scale (VAS) score decreased dramatically after the operation. The mean preoperative VAS score was greater in patients underwent posterior lumbar interbody fusion (PLIF) with longer duration of symptoms, longer operation time, and severe lumbar multifidus (LM) intramuscular adipose tissue (IMAT). The preoperative VAS score was dramatically lower in patients with lumbar herniation. The postoperative VAS score was dramatically lower in patients who underwent PLIF with longer operation time and mild LM IMAT. Postoperative LBP disappeared more often in patients who underwent PLIF with longer operation times. The number of operative levels and type of lumbar spine disease also were associated with postoperative LBP. CONCLUSION: Type of surgery, operation time, number of operative level, and type of disease were risk factors for the postoperative LBP. Patients underwent PLIF with shorter symptom duration, longer operation time severe LM IMAT, and lumber spondylolisthesis reported more severe LBP before the operation. Patients underwent discectomy with shorter operation times.

Predictors of Surgical Outcome in Acute Spinal Cord Injury Patients with Cervical Ossification of the Posterior Longitudinal Ligament.

OBJECTIVE: A retrospective study was conducted to clarify the predictors of the operation results for ossification of the posterior longitudinal ligament (OPLL) patients with acute spinal cord injury (SCI). Detailed analyses of surgical outcomes of OPLL patients with SCI have been rare because most surveys have aimed to investigate OPLL or SCI, but not both. PATIENTS AND METHODS: A total of 36 patients who underwent operation for OPLL between January 2011 and December 2011 were included in this analysis. We investigated the patients' characteristics and surgical approaches and compared the radiographic characteristics of OPLL patients with SCI. RESULTS: The mean modified Japanese Orthopaedic Association (mJOA) score improved dramatically after operation (P = 0.006). The mean preoperative mJOA score was greater in patients with Nurick 3 than in patients with Nurick 4 and 5 (P = 0.041). The preoperative mJOA score was dramatically lower in patients caused by traffic accident and in patients with segmental OPLL lesion (P < 0.05). The postoperative mJOA score was dramatically lower in patients with continuous OPLL lesion than in the segmental OPLL lesion (P = 0.028). Changing in mJOA score was significantly different between the patients with high-intensity zone (HIZ) and without HIZ on magnetic resonance imaging. CONCLUSIONS: HIZ on magnetic resonance imaging was significantly related to the surgical outcomes, which should be highlighted in the preoperative communication with patients. Patients with lower Nirick grade and segmental OPLL would show better symptom before the operation. In addition, SCI caused by slipping or falling showed better symptoms before the operation. Patients with segmental OPLL should show better resolution of symptoms after the operation.

Predictors of surgical outcome in ossification of the posterior longitudinal ligament.

STUDY DESIGN: A retrospective study. OBJECTIVE: To clarify the predictors of the operation results for ossification of the posterior longitudinal ligament (OPLL). SUMMARY OF BACKGROUND DATA: Detailed analyses of surgical outcomes of OPLL have been rare because most survey aimed to investigate cervical spondylotic myelopathy. METHODS: All patients who underwent cervical operation for OPLL between January 2011 and December 2011 were included in this analysis. We investigated the patients' characteristics and surgical approaches, and compared the radiographical characteristics of OPLL. RESULTS: The mean mJOA score improved from 8.312 ± 3.021 points preoperatively to 11.24 ± 3.43 points at 24 months after operation (P<0.001). The average change in mJOA score was significantly greater in patients with a higher Nirik score than in those with lower Nirik scores (P<0.0001). The average change in mJOA score was also significantly different in patients with trauma history (P<0.0001). The average recovery ratio was 42 ± 26.3% in young patients and 30 ± 31.6% in the group older than 50 years (P=0.012). The average recovery ratio in patients with acute and chronic symptoms was 48 ± 22.9% and 26 ± 33.9%, respectively. There was great difference between the two groups. CONCLUSION: OPLL patients with myelopathy would receive good result after the operation. Age and symptom duration are related to the surgical outcomes. Patients with lower Nirick grade and without trauma history would receive better results before and after the operation.

Extensor tendon injury due to repetitive wrist dorsiflexion: morphological study of extensor retinaculum and extensor tendon.

Most etiological studies of extensor tendon injury were based on the normal anatomy of extensor tendon and extensor retinaculum of the wrist. Further understanding of the morphological changes of the extensor tendon and extensor retinaculum during wrist dorsiflexion might contribute to improved and more accurate understanding of the etiology. The morphology of the extensor tendon of the mid-finger and the fourth compartment of the wrist extensor retinaculum was studied by sonography, and the anatomy was studied in 15 extremities from 11 young male cadavers. Compared with anatomical images, ultrasonography provides similar morphological observations of the extensor retinaculum of the wrist and extensor tendon. Ultrasonography findings revealed that as the dorsiflexion angle changed, the extensor retinaculum of the wrist formed different shaped trochleas. The trochlea guides the rotation of the extensor tendon at the wrist, but it does not form a sharp corner with the extensor tendon; thus, the extensor tendon is not compressed. As the dorsiflexion angle increased from 0° to 60°, the length of the trochlea gradually decreases. The shortening of the trochlea length will lead to a smaller frictional contact area between the extensor tendon and the extensor retinaculum. Consequently, the friction is centralized. During wrist dorsiflexion, the extensor retinaculum provides a trochlea for the extensor tendon. Extensor tendon injury of repetitive wrist dorsiflexion might be caused by centralized friction at the small contact area.

[Clinical application of a novel posterior lumbar fusion method and the short-term observation of its effect].

OBJECTIVE: To increase local blood supply of bone graft, a novel posterior lumbar spine fusion method with orthotopic paraspinal muscle-pediculated bone flaps was constructed, and the fusion rate and clinical effect.were observed. METHODS: From June 2007 to December 2010, 117 patients of lumbar spinal stenosis or lumbar destabilization treated with the novel posterior lumbar fusion method were studied, 49 males and 68 females, aged from 40 to 77 years, average 61.5 years. Clinical effect was evaluated by JOA and VAS score preoperatively and postoperatively, and the fusion result was evaluated by three-dimensional CT reconstruction postoperatively. RESULTS: Seventeen cases lost of follow up, the rest were followed up from 7 to 38 months, average 19 months. There was significant difference between pre- and postoperative JOA and VAS score (P < 0.01), the preoperative JOA score was 10.3 ± 1.9, and 25.4 ± 4.2 at the latest follow-up, the improvement rate was 81.0% ; the preoperative VAS score was 8.5 ± 0.8, and 2.3 ± 0.4 at the latest follow-up. The three-dimensional CT reconstruction showed that 126 of the 133 segments formed solid fusion in 100 patients who completed the follow-up, the fusion rate was 94.7%. CONCLUSION: The novel posterior lumbar fusion method make the bone graft position more precise, stable and increases the fusion rate, which can effectively reduce pseudarthrosis and have a promising clinical effect.

Cinnamtannin B-1 regulates cell proliferation of spinal cord astrocytes and protects the cell from oxygen-glucose-serum deprivation/reoxygenation-induced apoptosis.

Astrocytes are important for protecting neurons in the central nervous system. It has been reported that some antioxidants could protect astrocytes from ischemia/reperfusion-induced dysfunction. Cinnamtannin B-1 is a naturally occurring A-type proanthocyanidin that exhibits anti-oxidant properties. In this study, we investigated the effects of cinnamtannin B-1 on spinal cord astrocytes. Astrocytes were subjected to oxygen-glucose-serum deprivation for eight hours followed by reoxygenation with or without cinnamtannin B-1. We found that cinnamtannin B-1 protected astrocytes from oxygen-glucose-serum deprivation and reoxygenation-induced apoptosis. Concurrently, cinnamtannin B-1 promoted the proliferation of astrocytes whereas the extracellular regulated protein kinase (ERK) inhibitor reversed this effect. The results indicated that cinnamtannin B-1 protects astrocytes from oxygen-glucose-serum deprivation/reoxygenation-induced apoptosis by promoting astrocyte proliferation via an ERK pathway. Therefore, as an anti-oxidant, cinnamtannin B-1 might provide extra benefit for astrocyte protection during ischemia/reperfusion in the central nervous system.

Viability inhibition effect of gambogic acid combined with cisplatin on osteosarcoma cells via mitochondria-independent apoptotic pathway.

We previously demonstrated that gambogic acid (GA) is a promising chemotherapeutic compound for human osteosarcoma treatment. The aim of this study was to detect whether the combination of lower-dose GA (0.3 mg/L) and cisplatin (CDDP) (1 mg/L) could perform a synergistic effect on inhibiting tumor in four osteosarcoma cell lines. Our results showed that the combination between GA at lower dose and CDDP significantly exerts a synergistic effect on inhibiting the cellular viability in MG63, HOS, and U2OS cells. In contrast, an antagonistic character was detected in SAOS2 cells exposed to the combined use of lower-dose GA (0.3 mg/L) and CDDP (1 mg/L). Then, analysis of cell cycle showed the combination of both drugs significantly induced the G2/M phase arrest, without any difference relative to GA treatment alone, in MG63 cells. Flow-cytometric analysis of cell apoptosis displayed that the apoptotic rate in the combination group is higher than that in GA treatment alone in MG63, HOS, and U2OS cells. The combined use of both drugs had no effect on mitochondrial membrane potential, but promoted the apoptosis-inducing function through triggering of CDDP in the three cell lines. By measurement of mitochondrial membrane potential, the activity of caspase-3 and the expressions of caspase-8 and caspase-9, it was showed that the apoptosis-promoting effect of the combined use of both drugs could be dependent on the death receptor apoptosis pathway, not dependent on the mitochondria apoptosis mechanism. This research, for the first time, demonstrates that GA could increase the chemotherapeutic effect of CDDP in human osteosarcoma treatment through inducing the cell cycle arrest and promoting cell apoptosis.

Activation of satellite cells in the dorsal root ganglia in a disc-punctured rat model.

BACKGROUND: The neural mechanisms underlying discogenic low back pain caused by disc degeneration remain unclear. Previous studies demonstrated that satellite cells (SC) play an important role in neuropathic pain. METHODS: Twenty adult female Sprague-Dawley rats were used. The rats were divided into two groups: a nucleus pulposus (NP) group whose discs were punctured to expose the NP (n = 10) and a sham-operated group whose annulus fibrosus surface was scratched superficially (n = 10). In this study, we investigated the expression and cellular distribution of glial fibrillary acidic protein (GFAP, a marker of SC activation) in the dorsal root ganglia (DRG) innervating the intervertebral discs using a retrograde tracing method and immunohistochemistry in a disc-punctured rat model. RESULTS: In the sham-operated group, GFAP-immunoreactive (IR) SCs were not detected. In the NP group, GFAP-IR SC became evident, and 49 ± 13% of neurons innervating the punctured discs were surrounded by GFAP-positive SCs. CONCLUSIONS: Our results were the first to provide evidence for a potential role of SCs in the neural mechanisms of discogenic low back pain caused by disc degeneration.

Contralateral neuropathology in dorsal root ganglia in a rat model of noncompressive disc herniation.

Some cases of lumbar disc herniation with contralateral radiculopathy have been reported. Many investigators explained this clinical syndrome from several aspects. However, to our best knowledge, there is no explanation on the basis of molecular changes in the contralateral dorsal root ganglia (DRG) until now. We firstly explored the expression of activating transcription factor 3 (ATF3, a marker of nerve injury), glial fibrillary acidic protein (GFAP, a marker of satellite cells activation) in bilateral L5 DRG and spinal cord using immunohistochemistry after nucleus pulposus (NP) application onto the left L5 DRG exposed by unilateral facetectomy. Immunoblotting was used to detect the expression of tumor necrosis factor-alpha (TNF-alpha) in bilateral L5 DRG. We tested that ATF3-immunoreactive (IR) neurons, GFAP-IR satellite cells and TNF-alpha expression in the contralateral DRG increased significantly after NP application. In the spinal cord, ATF3-IR motor neurons increased significantly after surgery, but GFAP-IR astrocytes were not significant. These results suggested that NP application on the unilateral DRG could induce nerve injury, satellite cells activation and upregulation of TNF-alpha expression in the contralateral DRG. In addition, our results indicated that motor neurons injury might play a significant role in contralateral changes.

The influence of orthotopic paraspinal muscle-pediculated bone flaps on posterior spinal fusion in a canine model.

STUDY DESIGN: An experimental animal study with randomized, control design was conducted using a dog model. OBJECTIVE.: To construct a novel posterior lumbar spine fusion model with orthotopic paraspinal muscle-pediculated bone flaps and to compare with the conventional posterolateral lumbar intertransverse process fusion. SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated that paraspinal musculature provided important vascular ingrowth into the fusion mass. However, the blood supply of paraspinal muscles was still not sufficiently used in spinal fusion. In this study, we assessed the significant role of orthotopic paraspinal muscle-pediculated bone flaps in the healing of bone graft in spinal fusion. METHODS: Thirty-two mongrel dogs were randomly assigned to 2 groups to undergo either posterior spinal fusion with orthotopic paraspinal muscle-pediculated bone flaps (treatment group) or posterolateral intertransverse process fusion (control group) at L5-L6 segment. All the fusions used an autologous bone graft obtained from bilateral posterior iliac crests. The animals were killed at 8 weeks or 16 weeks after surgery. The lumbar spines were evaluated by radiology, histology, and biomechanics. RESULTS: Treatment groups showed an increasing trend on radiographic grades, manual palpation, and biomechanical stiffness compared with control groups at 8 and 16 weeks. Histologic analysis revealed that there was more mature woven bone in the treatment group than the controls at both points. At 8 weeks, the histologic fusion rate was 21.4% in the treatment group, 50% in the control group (P < 0.05); and at 16 weeks the fusion rate was 50% and 87.5% in the control group and the treatment group, respectively (P < 0.05). CONCLUSION: The use of orthotopic paraspinal musclepediculated bone flaps increased the rate and quality of fusion in the experimental spinal fusion model. This suggested that the novel posterior spinal fusion could be further developed for clinical application.

[In vitro study of combination rhOPG-Fc and alendronate on inhibition osteoclast].

OBJECTIVE: To study the effect of combination rhOPG-Fc and alendronate on mature osteoclasts. METHODS: Recombinant human osteoprotegerin secretory expression in P. pastoris was performed. Osteoblasts were got from new born mouse skeletal bone and proved by ALP staining and incubated together with osteoclasts precursor cell line Raw 264.7 in 96 well plate. After 9 d, 10 micromol/L ALN, 10(-5) g/L rhOPG-Fc, 10 micromol/L ALN + 10(-5) g/L rhOPG-Fc, 5 micromol/L ALN + 5 x 10(-6) g/L rhOPG-Fc were added to these coculture systems. Osteoblasts cultured without the drugs mentioned above served as controls. TRAP stain positive cells counting and cortical bone pit formation counting were preformed in the following the 3rd and 7th d. RESULTS: SDS-PAGE and Western blot showed that molecular weight of the expressed protein was about 55 KD, and it could reach specifically with anti-IgG antibody. Many multi-nuclear TRAP stain positive cells were found in the coculture control group after 9 d incubation, and proved to be mature osteoclasts by TRAP stain. In the 3rd and 7th d after the addition of rhOPG-Fc, ALN or both, TRAP stain positive cells counting and cortical bone pit formation counting decreased significantly in the rhOPG-Fc, ALN or both groups than in the control group, and the combine group (10(-5) g/L rhOPG-Fc + 10 micromol/L ALN) decreased most significantly when compared with rhopG-FC or ALN single. CONCLUSIONS: rhOPG-Fc can decrease the number of osteoclasts and inhibit their function. The combination of both rhOPG-Fc and ALN shows the significant inhibition effect on mature osteoclasts.

The relationship between bone-loss of steroid-induced osteonecrosis and local expression of OPG/OCIF.

OBJECTIVE: To probe the relationship between the osteoprotegerin/osteoclastogenesis inhibitory factor (OPG/OCIF) expression of bone and the relative bone-loss. METHODS: Steroid-induced osteonecrosis-model was reproduced in thirty-one new Zealand hares, and 24 ones were alive 3 days after administration of endotoxin and methylprednisolone. The alive creatures were divided into control group and trial groups randomly. After the creatures being executed, bone-density measurement of the femurs, HE staining, Ca(+ +) staining and OPG/OCIF immunohistochemistry staining were performed, followed by image processing and statistical analysis. RESULTS: In the early period of steroid-induced osteonecrosis, the local OPG/OCIF expression significantly decreased, with a large number of osteoclasts in the local medulla, followed by a progressively bone-loss. CONCLUSION: Corticosteroid could inhibit OPG/OCIF expression in the bone, increase the activity and differentiation of osteoclast relatively, and worsen bone-loss in steroid-induced osteonecrosis.