[Changes in the expression of large-conductance calcium-activated potassium channels in dorsal root ganglion neurons after electrical injury in rats’ sciatic nerves and its influence on sensory conduction function].

By Kamruz Zaman
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[Changes in the expression of large-conductance calcium-activated potassium channels in dorsal root ganglion neurons after electrical injury in rats’ sciatic nerves and its influence on sensory conduction function].

Zhonghua Shao Shang Za Zhi. 2016 Jun;32(6):363-9

Authors: Wang G, Li X, Xu X, Ren P

Abstract
OBJECTIVE: To study the changes in the expression of large-conductance calcium-activated potassium (BKCa) channels in dorsal root ganglion (DRG) neurons after electrical injury in rats’ sciatic nerves and its influence on sensory conduction function.
METHODS: One-hundred and thirty-six adult SD rats were divided into normal control group, sham electrical injury group, and 75, 100, 125 V electrical injury groups according to the random number table, with 8 rats in normal control group and 32 rats in each of the rest 4 groups. Rats in normal control group were routinely fed without any treatment. Blunt dissection of the sciatic nerves of left hind leg of rats was performed in sham electrical injury group, while sciatic nerves of left hind leg of rats in electrical injury groups were electrically injured with corresponding voltage. Eight rats of normal control group fed for one week, and 8 rats from each of the rest four groups on post injury day (PID) 3 and in post injury week (PIW) 1, 2, 3 respectively were collected to detect the paw withdrawal mechanical threshold (PWMT). In addition, rats of 100 V electrical injury group in PIW 1 were collected and intrathecally injected with NS1619 after former PWMT detection, and PWMT was detected per 30 minutes within three hours post injection. The rats in each group at each time point were sacrificed after PWMT detection. The DRG of L4 to L6 segments of spinal cord was sampled to observe the BKCa channels distribution with immunohistochemical staining and to detect the protein and mRNA expressions of BKCa channels with Western blotting and reverse transcription-polymerase chain reaction respectively. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test.
RESULTS: (1) The PWMT values of rats in 75 and 100 V electrical injury groups on PID 3 and in PIW 1, 2, 3 were (5.8±0.6), (5.0±0.8), (4.2±0.3), (5.9±1.1) g; (5.3±1.3), (5.9±2.0), (4.5±2.7), (4.3±1.3) g, respectively, which were significantly lower than the value (s) in normal control group [(11.2±2.0) g] and sham electrical injury group [respectively (11.3±2.1), (12.0±2.0), (11.1±1.6), (10.3±2.1) g, with P values below 0.05]. The PWMT values of rats in 125 V electrical injury group decreased obviously on PID 3 and in PIW 1 [(6.1±1.6) and (5.7±1.7) g] as compared with the value (s) in normal control group and sham electrical injury group, and they were obviously increased in PIW 2 and 3 [(26.7±3.3) and (21.7±3.4) g] as compared with the value (s) of the rest 4 groups (with P values below 0.05). The PWMT of 100 V electrical injury group in PIW 1 firstly increased and then decreased within three hours post injection, which increased significantly at post injection minutes 30, 60, 90, 120 as compared with that before intervention [respectively (8.5±0.8), (9.7±1.2), (11.0±1.5), (8.6±0.8) g, with P values below 0.05]. (2) The positive expression of BKCa channels in large amount was observed in the cytoplasm and cytomembrane of neurons on the DRG of rats in normal control group and sham electrical injury group at each time point. The positive expression of BKCa channels in the cytoplasm and cytomembrane of neurons on the DRG of rats decreased over time in electrical injury groups, which was most obvious in 125 V electrical injury group. (3) There were no statistically significant differences in the protein expression of BKCa channels in DRG of rats among the five groups on PID 3 (with P values above 0.05). Compared with those in normal control group (0.477±0.027, 0.521±0.034, 0.475±0.022) and sham electrical injury group (0.511±0.025, 0.489±0.025, 0.483±0.032) in PIW 1, 2, 3, the protein expressions of BKCa channels in DRG of rats in 75, 100, 125 V electrical injury groups were decreased significantly (0.274±0.026, 0.202±0.019, 0.285±0.033; 0.253±0.022, 0.233±0.024, 0.203±0.017; 0.092±0.017, 0.095±0.021, 0.087±0.016, with P values below 0.05). The protein expressions of BKCa channels in DRG of rats in 125 V electrical injury group in PIW 1, 2, 3 were obviously lower than those in 75 and 100 V electrical injury groups (with P values below 0.05). (4) The mRNA expression levels of BKCa channels in DRG of rats in 75, 100, 125 V electrical injury groups on PID 3 and in PIW 1, 2, 3 were 0.326±0.021, 0.238±0.019, 0.291±0.022, 0.364±0.018; 0.264±0.020, 0.293±0.017, 0.243±0.023, 0.295±0.021; 0.134±0.023, 0.089±0.017, 0.074±0.018, 0.087±0.020, respectively, significantly decreased as compared with the level (s) in normal control group (0.581±0.051) and sham electrical injury group (0.603±0.045, 0.586±0.032, 0.614±0.045, 0.572±0.038), with P values below 0.05. The mRNA expression levels of BKCa channels in DRG of rats in 125 V electrical injury group at each time point were lower than those in 75 and 100 V electrical injury groups (with P values below 0.05).
CONCLUSIONS: The electrical injury in sciatic nerves results in reduction of the BKCa channels expression in rat’s DRG of corresponding spinal segments, which plays a role in the pathological process of sensory conduction dysfunction.

PMID: 27321491 [PubMed – indexed for MEDLINE]

Acute and chronic injuries among senior international rowers: a cross-sectional study.

By London Spine
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Acute and chronic injuries among senior international rowers: a cross-sectional study.

Int Orthop. 2015 Jan 22;

Authors: Smoljanovic T, Bohacek I, Hannafin JA, Terborg O, Hren D, Pecina M, Bojanic I

Abstract
PURPOSE: The aim of the study was to define the types of musculoskeletal injuries present in senior international rowers. According to the literature, no such study has been performed in this group.
METHODS: Injury data were obtained from a total of 634 rowers (33 % female, 67 % male) who completed a 12-month retrospective questionnaire on injury incidence while participating in the Senior World Rowing Championships in Munich, Germany, in 2007.
RESULTS: The mean injury rate per one year was 0.92 injuries per rower (1.75 injuries per 1,000 training sessions per rower). The vast majority of self-reported injuries were chronic injuries (acute vs chronic ratio was 1:2.63), and the majority of reported injuries did not result in loss of time from training or competition. Of all acute injuries, 58.1 % were sustained during rowing-specific training, with 20.6 % injuries sustained in the gym and 21.3 % during cross-training. The most common site of injury was the low back followed by the knee and the chest/thoracic spine. Senior open weight rowers who sustained chronic injuries achieved significantly better final ranking at the 2007 Senior World Rowing Championships compared to the same group of rowers who did not sustain any injury.
CONCLUSION: Senior international rowers participating in World Rowing Championships sustained predominantly chronic (overuse) injuries during the rowing season studied. Those were mainly low severity injuries, with the low back being the most frequently injured site. This study may will help in prevention and early diagnosis of eventual injuries in top-level rowers.

PMID: 25603972 [PubMed – as supplied by publisher]

[Comparison of anterior lumbar fusion rates after circumferential fusion using beta-tricalcium phosphate (Cerasorb) versus autologous iliac crest spongiosa]

By London Spine

AIM: The aim of this prospective clinical trial was to analyse the ventral fusion rate following circumferential fusion for degenerative spine disease using a radiolucent carbon fibre cage (Brantigan, Fa. DePuy-Acromed) loaded with either autogeneous bone graft (iliac crest) or with the tricalcium phosphate Cerasorb with PRP (Curasan AG, Kleinostheim, Deutschland). METHODS: In 26 patients…

The epidemiology of Schmorl’s nodes and their correlation to radiographic degeneration in 4,151 subjects.

By London Spine
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The epidemiology of Schmorl’s nodes and their correlation to radiographic degeneration in 4,151 subjects.

Eur Spine J. 2013 Mar 16;

Authors: Sonne-Holm S, Jacobsen S, Rovsing H, Monrad H

Abstract
PURPOSE: Schmorl’s nodes (SNs) are commonly seen in vertebral imaging of the normal adult population referred for different reasons and are duly noted by the radiologist. However, little is known about their etiology: either SNs are perceived as largely inert developmental or congenital herniations of disc tissue into weak areas of the vertebral end-plates, or they are perceived as a common pathological pathway of different adverse and general factors such as malignancy, trauma, infection, osteoporosis, Paget’s disease and so forth. A commonly accepted morphological definition of what precisely constitute SNs does not exist, and consequently prevalences vary wildly in the literature. In the present study of 4,151 standardized lateral radiographs of the lumbar spine in an adult, Caucasian population between 22 and 93 years (median age 63 years, M 1,533, W 2,618). METHODS: We investigated prevalence, distribution and epidemiologic relationships of SNs. RESULTS: SNs occur primarily in the upper part of the lumbar spine, and usually there are multiple lesions in the same individual. We could not establish any significant correlation between SNs and gender, age, BMI, height, weight or occupational exposure for heavy lifting. The overall prevalence was 3.8 %. We did not find any significant correlations between SNs and overall degeneration of the lumbar spine. CONCLUSION: We found a prevalence of SNs in the lower end of the spectrum than hitherto reported.

PMID: 23503898 [PubMed – as supplied by publisher]

Sustained Effectiveness of 10?kHz High-Frequency Spinal Cord Stimulation for Patients with Chronic, Low Back Pain: 24-Month Results of a Prospective Multicenter Study.

By London Spine
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Sustained Effectiveness of 10 kHz High-Frequency Spinal Cord Stimulation for Patients with Chronic, Low Back Pain: 24-Month Results of a Prospective Multicenter Study.

Pain Med. 2013 Dec 5;

Authors: Al-Kaisy A, Van Buyten JP, Smet I, Palmisani S, Pang D, Smith T

Abstract
OBJECTIVE: The aim of this study was to investigate the long-term efficacy and safety of paresthesia-free high-frequency spinal cord stimulation (HF10 SCS) for the treatment of chronic, intractable pain of the low back and legs.
DESIGN: Prospective, multicenter, observational study.
METHOD: Patients with significant chronic low back pain underwent implantation of a spinal cord stimulator capable of HF10 SCS. Patients’ pain ratings, disability, sleep disturbances, opioid use, satisfaction, and adverse events were assessed for 24 months.
RESULTS: After a trial period, 88% (72 of 82) of patients reported a significant improvement in pain scores and underwent the permanent implantation of the system. Ninety percent (65 of 72) of patients attended a 24-month follow-up visit. Mean back pain was reduced from 8.4 ± 0.1 at baseline to 3.3 ± 0.3 at 24 months (P < 0.001), and mean leg pain from 5.4 ± 0.4 to 2.3 ± 0.3 (P < 0.001). Concomitantly to the pain relief, there were significant decreases in opioid use, Oswestry Disability Index score, and sleep disturbances. Patients’ satisfaction and recommendation ratings were high. Adverse Events were similar in type and frequency to those observed with traditional SCS systems.
CONCLUSIONS: In patients with chronic low back pain, HF10 SCS resulted in clinically significant and sustained back and leg pain relief, functional and sleep improvements, opioid use reduction, and high patient satisfaction. These results support the long-term safety and sustained efficacy of HF10 SCS.

PMID: 24308759 [PubMed – as supplied by publisher]