Sex Differences in the Serum Proteomic Profile During Acute Low Back Pain-A Preliminary Study of the Relationship to Future Low Back Pain

The molecular processes driving the transition from acute to chronic low back pain (LBP) remain poorly understood and are likely to be sexually dimorphic. This study aimed to explore sex differences in the serum proteomic profile of people experiencing an acute LBP episode and determine if serum protein concentrations were associated with three-month outcome. Serum samples were collected through venepuncture from 30 female and 29 male participants experiencing an acute LBP episode. Serum samples underwent trypsin digestion and fractionation using hydrophobic interaction chromatography and were then analysed using mass-spectrometry. Mass-spectrometry spectra were searched in the Swissprot database for protein identification. Sex differences in protein abundance changes were evident upon inspection of fold changes. Multivariable data analysis identified 21 serum proteins during the acute episode that correctly classified 93% of males and 23 serum proteins that correctly classified 90% of females with ongoing LBP at 3 months. Pathway analysis suggested the differentially expressed proteins during acute LBP were frequently involved in immune, inflammatory, complement, or coagulation responses. This data provides preliminary evidence that biological processes during an acute LBP episode may contribute to the resolution, or persistence, of LBP symptoms at 3 months, however, these processes differ between males and females. PERSPECTIVE: Differential expression of serum proteins was observed between male and female participants during an acute LBP episode. This preliminary work provides a foundation for future research targeting distinct immune system processes in males and females that may interfere with the transition from acute to chronic LBP.

Combined transcranial magnetic stimulation and electroencephalography reveals alterations in cortical excitability during pain

Transcranial magnetic stimulation (TMS) has been used to examine inhibitory and facilitatory circuits during experimental pain and in chronic pain populations. However, current applications of TMS to pain have been restricted to measurements of motor evoked potentials (MEPs) from peripheral muscles. Here, TMS was combined with electroencephalography (EEG) to determine whether experimental pain could induce alterations in cortical inhibitory/facilitatory activity observed in TMS-evoked potentials (TEPs). In Experiment 1 (n=29), multiple sustained thermal stimuli were administered to the forearm, with the first, second, and third block of thermal stimuli consisting of warm but non-painful (pre-pain block), painful (pain block) and warm but non-painful (post-pain block) temperatures, respectively. During each stimulus, TMS pulses were delivered while EEG (64 channels) was simultaneously recorded. Verbal pain ratings were collected between TMS pulses. Relative to pre-pain warm stimuli, painful stimuli led to an increase in the amplitude of the frontocentral negative peak ~45 ms post-TMS (N45), with a larger increase associated with higher pain ratings. Experiments 2 and 3 (n=10 in each) showed that the increase in the N45 in response to pain was not due to changes in sensory potentials associated with TMS, or a result of stronger reafferent muscle feedback during pain. This is the first study to use combined TMS-EEG to examine alterations in cortical excitability in response to pain. These results suggest that the N45 TEP peak, which indexes GABAergic neurotransmission, is implicated in pain perception and is a potential marker of individual differences in pain sensitivity.

[In vitro activity of β-lactamase inhibitors avibanvctam and relebactam in combination with β-lactams against multidrug-resistant Mycobacterium tuberculosis and mutations of resistance genes]

Objective: To evaluate the activity of six β-lactams in combination with three β-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro. Methods: A total of 105 multidrug-resistant tuberculosis (MDR-TB) strains from different regions of Henan province from January to September 2020 were included in this study. Drug activity of six β-lactams (biapenem, meropenem, imipenem, doripenem, ertapenem and tebipenem) alone or in combination with β-lactamase inhibitors (clavulanic acid, avibactam and relebactam) was examined by minimum inhibitory concentration method (MICs) against 105 clinical isolates. Mutations of blaC, ldtmt1 and ldtmt2 were analyzed by PCR and DNA sequencing. Chi-square test was used to compare the antimicrobial activities of different β-lactam drugs. Results: Out of the β-lactams used herein, tebipenem was the most effective against MDR-TB and had an MIC50 value of 8 mg/L(χ2=123.70,P=0.001). Besides, after the addition of β-lactamase inhibitors, the MICs of most β-lactam drugs were reduced more evidently in the presence of avibactam and relebactam compared to clavulanic acid.Especially, relebactam decreased both the MIC50 and MIC90 of telbipenem by 16-fold, and diluted the MIC of 23 (21.90%) and 41 (39.04%) isolatesby 32-fold and 16-fold.In addition, a total of 13.33% (14/105) of isolates harbored mutations in the blaC gene, with three different nucleotide substitutions: AGT333AGG, AAC638ACC and ATC786ATT. For the strains with Ser111Arg and Asn213Thr substitution in BlaC, the MIC values of the meropenem-clavulanate combination were reduced compared with a synonymous single nucleotide polymorphism (SNP) group. Conclusions: Both avibactam and relebactam had better synergistic effects on β-lactams than clavulanic acid. The combination of tebipenem and relebactam showed the most potent activity against MDR-TB isolates. In addition, the Ser111Arg and Asn213Thr substitution of BlaC may be associated with an increased susceptibility of MDR-TB isolates to meropenem in the presence of clavulanate.

Alterations in cortical excitability during pain: A combined TMS-EEG Study

Transcranial magnetic stimulation (TMS) has been used to examine inhibitory and facilitatory circuits during experimental pain and in chronic pain populations. However, current applications of TMS to pain have been restricted to measurements of motor evoked potentials (MEPs) from peripheral muscles. Here, TMS was combined with electroencephalography (EEG) to determine whether experimental pain could induce alterations in cortical inhibitory/facilitatory activity observed in TMS-evoked potentials (TEPs). In Experiment 1 (n = 29), multiple sustained thermal stimuli were administered to the forearm, with the first, second and third block of thermal stimuli consisting of warm but non-painful (pre-pain block), painful (pain block) and warm but non-painful (post-pain block) temperatures respectively. During each stimulus, TMS pulses were delivered while EEG (64 channels) was simultaneously recorded. Verbal pain ratings were collected between TMS pulses. Relative to pre-pain warm stimuli, painful stimuli led to an increase in the amplitude of the frontocentral negative peak ~45ms post-TMS (N45), with a larger increase associated with higher pain ratings. Experiments 2 and 3 (n = 10 in each) showed that the increase in the N45 in response to pain was not due to changes in sensory potentials associated with TMS, or a result of stronger reafferent muscle feedback during pain. This is the first study to use combined TMS-EEG to examine alterations in cortical excitability in response to pain. These results suggest that the N45 TEP peak, which indexes GABAergic neurotransmission, is implicated in pain perception and is a potential marker of individual differences in pain sensitivity.

Systemic pro- and anti-inflammatory profiles in acute non-specific low back pain: An exploratory longitudinal study of the relationship to six-month outcome

OBJECTIVES

Pro-inflammatory molecules are thought to underpin the development of chronic low back pain (LBP). Although research has begun to explore the association between pro-inflammatory molecules in acute LBP and long-term outcome, no study has explored the role of anti-inflammatory molecules. We aimed to explore whether levels of systemic pro- and anti-inflammatory molecules 1) changed over a period of six months from the onset of acute LBP; 2) differed between people who were recovered (N = 11) and unrecovered (N = 24) from their episode of LBP at six months; 3) baseline psychological factors were related to inflammatory molecule serum concentrations at baseline, three and six months.

METHODS

We retrospectively included participants with acute LBP included from a larger prospective trial and examined blood samples for the measurement of pro- and anti-inflammatory molecules and measures of pain, disability, and psychological factors at baseline, three and six months.

RESULTS

The serum concentrations of pro- and anti-inflammatory molecules did not differ over time when compared between participants who recovered and those who did not recover at six-month follow-up. At three months, the unrecovered group had higher interleukin (IL)-8 and IL-10 serum concentrations than the recovered group. Baseline psychological factors were not related to inflammatory molecules at any time point.

DISCUSSION

This exploratory study showed that levels of systemic inflammatory molecules did not change over the course of LBP, irrespective of whether people were recovered or unrecovered at six months. There was no relationship between acute-stage psychological factors and systemic inflammatory molecules. Further investigation is needed to elucidate the contribution of pro- and anti-inflammatory molecules to long-term LBP outcome.

Human assumed central sensitization in people with acute non-specific low back pain: A cross-sectional study of the association with brain-derived neurotrophic factor, clinical, psychological and demographic factors

BACKGROUND

Early evidence suggests human assumed central sensitization (HACS) is present in some people with acute low back pain (LBP). Factors influencing individual variation in HACS during acute LBP have not been fully explored. We aimed to examine the evidence for HACS in acute LBP and the contribution of brain-derived neurotrophic factor (BDNF), clinical, psychological and demographic factors to HACS.

METHODS

Participants with acute LBP (<6 weeks after pain onset, N = 118) and pain-free controls (N = 57) from a longitudinal trial were included. Quantitative sensory testing including pressure and heat pain thresholds and conditioned pain modulation, BDNF serum concentration and genotype and questionnaires were assessed.

RESULTS

There were no signs of HACS during acute LBP at group level when compared with controls. Sensory measures did not differ when compared between controls and LBP participants with different BDNF genotypes. Two LBP subgroups with distinct sensory profiles were identified. Although one subgroup (N = 60) demonstrated features of HACS including pressure/heat pain hypersensitivity at a remote site and deficient conditioned pain modulation, pain severity and disability did not differ between the two subgroups. Variation in sensory measures (~33%) was partially explained by BDNF genotype, sex, age and psychological factors.

CONCLUSIONS

This study confirms that HACS is present in some people with acute LBP, but this was not associated with pain or disability. Further, no relationship was observed between BDNF and HACS in acute LBP. More research is needed to understand factors contributing to individual variation in sensory measures in LBP.

SIGNIFICANCE

Human assumed central sensitization (HACS) is present in acute low back pain (LBP) but factors contributing to individual variation are not fully explored. This study investigated the relationship between factors such as brain derived neurotrophic factor (BDNF) and HACS in acute LBP. Our findings indicate that HACS was present in specific LBP subgroups but BDNF was unrelated to HACS. Combinations of BDNF genotype, demographic and psychological factors explained a small proportion of the variation in sensory measures during acute LBP.

Unintrusive multi-cancer detection by circulating cell-free DNA methylation sequencing (THUNDER): development and independent validation studies

BACKGROUND

Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of ELSA-seq, a previously described cfDNA methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary and pancreas.

PATIENTS AND METHODS

A customized panel of 161,984 CpG sites was constructed and validated by public and in-house (cancer: n=249; non-cancer: n=288) methylome data, respectively. The cfDNA samples from 1,693 participants (cancer: n=735; non-cancer: n=958) were retrospectively collected to train and validate two multi-cancer detection blood test models (MCDBT-1/2) for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1,010 participants (cancer: n=505; non-cancer: n=505). Simulation using the cancer incidence in China was applied to infer stage-shift and survival benefits to demonstrate the potential utility of the models in the real world.

RESULTS

MCDBT-1 yielded a sensitivity of 69.1% (64.8%‒73.3%), a specificity of 98.9% (97.6%‒99.7%) and tissue origin accuracy of 83.2% (78.7%‒87.1%) in the independent validation set. For early stage (I‒III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%‒65.0%). In the real-world simulation, MCDBT-1 achieved the sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%‒46.4%, and increasing 5-year survival rate by 33.1%‒40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance.

CONCLUSION

In this large-scale clinical validation study, MCDBT-1/2 models showed a high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.

Relative and absolute reliability of somatosensory evoked potentials in response to non-noxious electrical stimulation of the paraspinal muscles in healthy participants at an interval of 3-months

BACKGROUND

Somatosensory evoked potentials (SEPs) are used extensively to quantify cortical activity in response to noxious and/or non-noxious sensory stimuli. However, data demonstrating the reliability of SEP measures in response to non-noxious stimulation over time are scarce.

AIM

We investigated the relative and absolute reliability, and the smallest detectable change at 95% confidence (SDC₉₅) for SEPs evoked by non-noxious electrical stimulation of the paraspinal muscles in thirty-nine healthy participants at a 3-month interval.

METHODS

SEPs were evoked at an intensity three-times that of each participant's perceptual threshold and recorded from a single electrode placed over the primary somatosensory cortex (S1).

RESULTS

Our analyses reveal that i) latency, as a measure of activity onset, has poor relative reliability but good absolute reliability; ii) area, as a measure of cortical activity, has good relative and absolute reliability (except for the N₁₅₀ component) and iii) perceptual threshold and stimulation intensity was not reliable over time.

CONCLUSION

These findings suggest that the area of the N₈₀ and P₂₆₀ SEP components, and the area of the N₈₀-N₁₅₀-P₂₆₀ SEP complex, can be utilised in future studies as reliable markers of cortical activity.

The effect of theta burst stimulation over the primary motor cortex on experimental hamstring pain: A randomised, controlled study

Theta burst stimulation (TBS) over the primary motor cortex (M1) is an emerging technique that may have utility in the treatment of musculoskeletal pain. However, previous work exploring the analgesic effects of noninvasive brain stimulation has been limited largely to the arm or hand, despite 80% of acute musculoskeletal injuries occurring in the lower limb. This is a pertinent point, given the functional and neurophysiological differences between upper and lower limb musculature, as well as evidence suggesting that reorganization of corticomotor pathways is region-specific. This study investigated the effect of excitatory TBS on pain, function, and corticomotor organization during experimentally induced lower limb pain. Twenty-eight healthy participants attended 2 experimental sessions. On Day 0, participants completed 10 sets of 10 maximal eccentric contractions of the right hamstring muscles to induce delayed onset muscle soreness. Four consecutive blocks of either active or sham TBS were delivered on Day 2. Measures of mechanical sensitivity, pain (muscle soreness, pain intensity, pain area) function (single-leg hop distance, maximum voluntary isometric contraction, lower extremity functional scale), and corticomotor organization were recorded before and after TBS on Day 2. Pain and function were also assessed daily from Days 2 to 10. Active TBS reduced mechanical sensitivity compared to sham stimulation (P = .01). Corticomotor organization did not differ between groups, suggesting that improvements in mechanical sensitivity were not mediated by changes in M1. Subjective reports of pain intensity and function did not change following active TBS, contrasting previous reports in studies of the upper limb. PERSPECTIVE: M1 TBS reduces mechanical sensitivity associated with experimentally induced hamstring pain. Though further work is needed, these findings may hold important implications for those seeking to expedite recovery or reduce muscle sensitivity following hamstring injury.

The Effect of Acute and Sustained Pain on Corticomotor Excitability: A Systematic Review and Meta-Analysis of Group and Individual Level Data

Pain alters motor function. This is supported by studies showing reduced corticomotor excitability in response to experimental pain lasting &lt;90 minutes. Whether similar reductions in corticomotor excitability are present with pain of longer durations or whether alterations in corticomotor excitability are associated with pain severity is unknown. Here we evaluated the evidence for altered corticomotor excitability in response to experimental pain of differing durations in healthy individuals. Databases were systematically searched for eligible studies. Measures of corticomotor excitability and pain were extracted. Meta-analyses were performed to examine: (1) group-level effect of pain on corticomotor excitability, and (2) individual-level associations between corticomotor excitability and pain severity. 49 studies were included. Corticomotor excitability was reduced when pain lasted milliseconds-seconds (hedges g's = -1.26 to -1.55) and minutes-hours (g's = -0.55 to -0.9). When pain lasted minutes-hours, a greater reduction in corticomotor excitability was associated with lower pain severity (g = -0.24). For pain lasting days-weeks, there were no group level effects (g = -0.18 to 0.27). However, a greater reduction in corticomotor excitability was associated with higher pain severity (g = 0.229). In otherwise healthy individuals, suppression of corticomotor excitability may be a beneficial short-term strategy with long-term consequences. PERSPECTIVE: This systematic review synthesised the evidence for altered corticomotor excitability in response to experimentally induced pain. Reduced corticomotor excitability was associated with lower acute pain severity but higher sustained pain severity, suggesting suppression of corticomotor excitability may be a beneficial short-term adaptation with long-term consequences.

Evaluating methodological quality of prognostic prediction models on patient reported outcome measurements after total hip replacement and total knee replacement surgery: a systematic review protocol

BACKGROUND

Prediction models for poor patient-reported surgical outcomes after total hip replacement (THR) and total knee replacement (TKR) may provide a method for improving appropriate surgical care for hip and knee osteoarthritis. There are concerns about methodological issues and the risk of bias of studies producing prediction models. A critical evaluation of the methodological quality of prediction modelling studies in THR and TKR is needed to ensure their clinical usefulness. This systematic review aims to (1) evaluate and report the quality of risk stratification and prediction modelling studies that predict patient-reported outcomes after THR and TKR; (2) identify areas of methodological deficit and provide recommendations for future research; and (3) synthesise the evidence on prediction models associated with post-operative patient-reported outcomes after THR and TKR surgeries.

METHODS

MEDLINE, EMBASE, and CINAHL electronic databases will be searched to identify relevant studies. Title and abstract and full-text screening will be performed by two independent reviewers. We will include (1) prediction model development studies without external validation; (2) prediction model development studies with external validation of independent data; (3) external model validation studies; and (4) studies updating a previously developed prediction model. Data extraction spreadsheets will be developed based on the CHARMS checklist and TRIPOD statement and piloted on two relevant studies. Study quality and risk of bias will be assessed using the PROBAST tool. Prediction models will be summarised qualitatively. Meta-analyses on the predictive performance of included models will be conducted if appropriate. A narrative review will be used to synthesis the evidence if there are insufficient data to perform meta-analyses.

DISCUSSION

This systematic review will evaluate the methodological quality and usefulness of prediction models for poor outcomes after THR or TKR. This information is essential to provide evidence-based healthcare for end-stage hip and knee osteoarthritis. Findings of this review will contribute to the identification of key areas for improvement in conducting prognostic research in this field and facilitate the progress in evidence-based tailored treatments for hip and knee osteoarthritis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42021271828.

Development of a micro-electrochemical machining nanosecond pulse power supply

Micro-electrochemical machining (micro-ECM) has been widely used for microscale and nanoscale processing of materials. The performance of the nanosecond pulse power supply is directly related to the precision of micro-ECM, which is one of the core technologies for micro-ECM. In this work, a nanosecond pulse power supply, with adjustable pulse frequency, duty cycle, and voltage, was designed with an STM32F103VET6 single-chip microcomputer as the control core and a metal-oxide-semiconductor field-effect transistor as the chopper switch component. The performance test has shown that the power supply can produce a continuous pulse with the highest frequency of 8 MHz, the shortest pulse width of 50 ns, the maximum peak current of 12 A, and the maximum voltage of 10 V. As compared with the power supply reported in the literature, the present power supply demonstrated the enhanced output current and improved waveform of the nanosecond pulse output, which could result in better machining accuracy and efficiency for micro-ECM.

The analgesic effect of electroencephalographic neurofeedback for people with chronic pain: A systematic review and meta-analysis

BACKGROUND

Electroencephalographic (EEG) neurofeedback has been utilized to regulate abnormal brain activity associated with chronic pain.

METHODS

In this systematic review, we synthesized the evidence from randomized controlled trials (RCTs) to evaluate the effect of EEG neurofeedback on chronic pain using random effects meta-analyses. Additionally, we performed a narrative review to explore the results of non-randomized studies. The quality of included studies was assessed using Cochrane risk of bias tools, and the GRADE system was used to rate the certainty of evidence.

RESULTS

Ten RCTs and 13 non-randomized studies were included. The primary meta-analysis on nine eligible RCTs indicated that although there is low confidence, EEG neurofeedback may have a clinically meaningful effect on pain intensity in short-term. Removing the studies with high risk of bias from the primary meta-analysis resulted in moderate confidence that there remained a clinically meaningful effect on pain intensity. We could not draw any conclusion from the findings of non-randomized studies, as they were mostly non-comparative trials or explorative case series. However, the extracted data indicated that the neurofeedback protocols in both RCTs and non-randomized studies mainly involved the conventional EEG neurofeedback approach, which targeted reinforcing either alpha or sensorimotor rhythms and suppressing theta and/or beta bands on one brain region at a time. A posthoc analysis of RCTs utilizing the conventional approach resulted in a clinically meaningful effect estimate for pain intensity.

CONCLUSION

Although there is promising evidence on the analgesic effect of EEG neurofeedback, further studies with larger sample sizes and higher quality of evidence are required.

Low Somatosensory Cortex Excitability in the Acute Stage of Low Back Pain Causes Chronic Pain

Determining the mechanistic causes of complex biopsychosocial health conditions such as low back pain (LBP) is challenging, and research is scarce. Cross-sectional studies demonstrate altered excitability and organization of the somatosensory and motor cortex in people with acute and chronic LBP, however, no study has explored these mechanisms longitudinally or attempted to draw causal inferences. Using sensory evoked potential area measurements and transcranial magnetic stimulation derived map volume we analyzed somatosensory and motor cortex excitability in 120 adults experiencing acute LBP. Following multivariable regression modelling with adjustment for confounding, we identified lower primary (OR = 2.08, 95% CI = 1.22-3.57) and secondary (OR = 2.56, 95% CI = 1.37-4.76) somatosensory cortex excitability significantly increased the odds of developing chronic pain at 6-month follow-up. Corticomotor excitability in the acute stage of LBP was associated with higher pain intensity at 6-month follow-up (B = -0.15, 95% CI: -0.28 to -0.02) but this association did not remain after confounder adjustment. These data provide evidence that low somatosensory cortex excitability in the acute stage of LBP is a cause of chronic pain. PERSPECTIVE: This prospective longitudinal cohort study design identified low sensorimotor cortex excitability during the acute stage of LBP in people who developed chronic pain. Interventions that target this proposed mechanism may be relevant to the prevention of chronic pain.

[Synchronous robotic resection for colorectal liver metastasis]

Surgical resection remains the only curative therapy for colorectal adenocarcinoma and liver metastasis. Synchronous robotic resection for colorectal liver metastasis (CRLM) offers the advantage of avoiding double surgical stress, while providing the benefits of small incision, quicker recovery, shorter hospital stay and faster postoperative adjuvant therapy. Compared with the laparoscopic approach, robotic approach is mostly suitable for rectal cancer liver metastasis, which is associated with low conversion rate, good nerve protection, high success rate for major hepatectomy and resection of difficult segments. Appropriately selected patients, multidisciplinary cooperation and skillful robotic surgeons are the key to success. Current data have demonstrated the feasibility and safety of synchronous robotic resection for CRLM. With the coming randomized controlled trial data and evolution of robotic surgical system, the future of synchronous robotic resection for colorectal liver metastasis is promising.

The Analgesic Effect of Electroencephalographic Neurofeedback for People With Chronic Pain: Protocol for a Systematic Review and Meta-analysis

Background

Chronic pain is a global health problem, affecting around 1 in 5 individuals in the general population. The understanding of the key role of functional brain alterations in the generation of chronic pain has led researchers to focus on pain treatments that target brain activity. Electroencephalographic neurofeedback attempts to modulate the power of maladaptive electroencephalography frequency powers to decrease chronic pain. Although several studies have provided promising evidence, the effect of electroencephalographic neurofeedback on chronic pain is uncertain.

Objective

This systematic review aims to synthesize the evidence from randomized controlled trials to evaluate the analgesic effect of electroencephalographic neurofeedback. In addition, we will synthesize the findings of nonrandomized studies in a narrative review.

Methods

We will apply the search strategy in 5 electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycInfo, and CINAHL) for published studies and in clinical trial registries for completed unpublished studies. We will include studies that used electroencephalographic neurofeedback as an intervention for people with chronic pain. Risk-of-bias tools will be used to assess methodological quality of the included studies. We will include randomized controlled trials if they have compared electroencephalographic neurofeedback with any other intervention or placebo control. The data from randomized controlled trials will be aggregated to perform a meta-analysis for quantitative synthesis. The primary outcome measure is pain intensity assessed by self-report scales. Secondary outcome measures include depressive symptoms, anxiety symptoms, and sleep quality measured by self-reported questionnaires. We will investigate the studies for additional outcomes addressing adverse effects and resting-state electroencephalography analysis. Additionally, all types of nonrandomized studies will be included for a narrative synthesis. The intended and unintended effects of nonrandomized studies will be extracted and summarized in a descriptive table.

Results

Ethics approval is not required for a systematic review, as there will be no patient involvement. The search for this systematic review commenced in July 2020, and we expect to publish the findings in early 2021.

Conclusions

This systematic review will provide recommendations for researchers and health professionals, as well as people with chronic pain, about the evidence for the analgesic effect of electroencephalographic neurofeedback.

Trial Registration

International Prospective Register of Systematic Reviews (PROSPERO) CRD42020177608; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=177608

International Registered Report Identifier (IRRID)

PRR1-10.2196/22821

[Experience of teaching and training for medical students at gastrointestinal surgery department under COVID-19 epidemic situation]

In hospitals and medical schools as densely populated sites with high risk of coronavirus disease 2019 (COVID-19), it is vital to adjust the teaching and training strategy for medical students to ensure curriculum completion with safety. This article aims to introduce the experience of teaching and training for medical students under the epidemic situation at Department of Surgery, Shanghai Medical College, Fudan University and Zhongshan Hospital. The content includes exploring diversified online teaching models for undergraduate surgery courses and clinical practice, carrying out online graduate education and dissertation plans, and strengthening comprehensive education of medical humanity combined with knowledge of COVID-19 prevention. Through implementation of the above teaching strategies, scheduled learning plans of medical students can be well completed in an orderly, safe and quality-ensured manner. Our experience provides practical solution of medical teaching and could be advisable for other medical colleges and teaching hospitals.

[Risk factors of anastomotic leakage after robotic surgery for low and mid rectal cancer]

Objective: To investigate the risk factors associated with anastomotic leakage after robotic surgery in mid-low rectal cancer. Methods: A retrospective case-control study method was conducted. Inclusion criteria: (1) 18 to 80 years old; (2) pathologically confirmed rectal cancer; (3) distance <10 cm from tumor to anal margin; (4) robotic anterior rectal resection. Patients with previous history of colorectal cancer surgery, distant metastases or other malignant tumors, undergoing emergency surgery, with severe abdominal adhesions or those receiving combined organ resection were excluded. Based on the above criteria, 636 patients undergoing robotic radical sphincter-preserving surgery for mid-low rectal cancer in Zhongshan Hospital from January 2015 to December 2018 were included in this study, including 398 males (62.6%) and 238 females (37.4%) with a mean age of (61.9±11.3) years. Sixty-eight cases (10.7%) received neoadjuvant chemoradiotherapy. Amony the 636 included patients, 123(19.3%) underwent natural orifice specimen extraction surgery (NOSES) and 15 (2.3%) underwent preventive stoma. According to the cirteria developed by the International Rectal Cancer Research Group in 2010, the anastomotic leakage was classified as grade A (no requirement of intervention), B (requirement of intervention), and C (requirement of operation). Logistic regression was used to analyze the relationship between anastomotic leakage and clinicopathological factors. Factors in univariate analysis with P<0.05 were included in the multivariate analysis. Results: Anastomotic leakage occurred in 38 cases (6.0%). The grading of anastomotic leakage was grade A in 13 cases (2.0%), grade B in 19 cases (3.0%), and grade C in 6 cases (0.9%). The 3-year disease-free survival rate of patients with anastomotic leakage and without anastomotic leakage was 83.5% and 83.6% respectively (P=0.862); the 3-year overall survival rate of the two group was 85.1% and 87.5% respectively (P=0.296). The results of univariate logistic regression analysis showed that male (P=0.011), longer operation time (P=0.042), distance ≤5 cm from tumor to anal margin (P=0.012), more intraoperative blood loss (P=0.048) were associated with anastomotic leakage (all P<0.05). NOSES was not associated with anastomotic leakage (P=0.704). Multivariate analysis confirmed that male (OR=3.03, 95%CI: 1.37 to 7.14, P=0.010), operation time ≥180 minutes (OR=2.04, 95%CI: 1.03 to 3.99, P=0.040), distance ≤5 cm from tumor to anal margin (OR=2.56, 95%CI:1.28 to 5.26, P=0.008) were independent risk factors for anastomotic leakage. Conclusion: Male, short distance from tumor to anal margin, and long operation time are independent risk factors for anastomotic leakage in patients undergoing robotic mid-low rectal cancer radical surgeries. These patients need to be cautiously treated during surgery.

Is there a causal relationship between acute stage sensorimotor cortex activity and the development of chronic low back pain? a protocol and statistical analysis plan

INTRODUCTION

Why some people develop chronic pain following an acute episode of low back pain is unknown. Recent cross-sectional studies have suggested a relationship between aberrant sensorimotor cortex activity and pain persistence. The UPWaRD (Understanding persistent Pain Where it ResiDes) cohort study is the first prospective, longitudinal investigation of sensorimotor cortex activity in low back pain. This paper describes the development of a causal model and statistical analysis plan for investigating the causal effect of sensorimotor cortex activity on the development of chronic low back pain.

METHODS AND ANALYSIS

Sensorimotor cortex activity was assessed within 6 weeks of low back pain onset using somatosensory evoked potentials and transcranial magnetic stimulation mapping techniques. Chronic low back pain is defined as ongoing pain (Numerical Rating score ≥1) or disability (Roland Morris Disability Questionnaire score ≥3) at 6 months follow-up. Variables that could confound the relationship between sensorimotor cortex activity and chronic low back pain were identified using a directed acyclic graph and content expertise was used to specify known causal paths. The statistical model was developed 'a priori' to control for confounding variables identified in the directed acyclic graph, allowing an unbiased estimate of the causal effect of sensorimotor activity in acute low back pain on the development of chronic pain. The statistical analysis plan was finalised prior to follow-up of all participants and initiation of analysis.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Western Sydney University Human Research Ethics Committee (H10465) and from Neuroscience Research Australia (SSA: 16/002). Dissemination will occur through presentations at national and international conferences and publications in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000002189 (retrospectively registered).

Do sensorimotor cortex activity, an individual's capacity for neuroplasticity, and psychological features during an episode of acute low back pain predict outcome at 6 months: a protocol for an Australian, multisite prospective, longitudinal cohort study

INTRODUCTION

Low back pain (LBP) is the leading cause of disability worldwide, with prevalence doubling in the past 14 years. To date, prognostic screening tools display poor discrimination and offer no net benefit of screening over and above a 'treat all' approach. Characteristics of the primary sensory (S1) and motor (M1) cortices may predict the development of chronic LBP, yet the prognostic potential of these variables remains unknown. The Understanding persistent Pain Where it ResiDes (UPWaRD) study aims to determine whether sensorimotor cortex activity, an individual's capacity for plasticity and psychosocial factors in the acute stage of pain, predict LBP outcome at 6 months. This paper describes the methods and analysis plan for the development of the prediction model.

METHODS AND ANALYSIS

The study uses a multicentre prospective longitudinal cohort design with 6-month follow-up. 120 participants, aged 18 years or older, experiencing an acute episode of LBP (less than 6 weeks duration) will be included. Primary outcomes are pain and disability.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Western Sydney University Human Research Ethics Committee (H10465) and from Neuroscience Research Australia (SSA: 16/002). Dissemination will occur through presentations at national and international conferences and publications in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000002189; Pre-results.

Sensorimotor Cortical Activity in Acute Low Back Pain: A Cross-Sectional Study

Sensorimotor cortical activity is altered in both the immediate acute and chronic stages of musculoskeletal pain. However, these changes are opposite, with decreased cortical activity reported in experimentally induced acute pain (lasting minutes to hours), and increased cortical activity in chronic, clinical pain (lasting >6 months). It is unknown whether sensorimotor cortical activity is altered in acute, clinical musculoskeletal pain (lasting <4 weeks). In 36 individuals with acute, nonspecific, clinical low back pain (LBP) and 36 age- and sex-matched, pain-free controls, we investigated the processing of non-noxious afferent inputs using sensory evoked potentials (SEPs), as well as corticomotor excitability and organization of the primary motor cortex using transcranial magnetic stimulation. Processing of non-noxious sensory inputs was lower (smaller area of the N₈₀-N₁₅₀-P₂₆₀ SEP complex) in acute LBP (F_1,70 = 45.28, P < .01). The examination of specific SEP components revealed a smaller area of the N₁₅₀ and P₂₆₀ SEP components in acute LBP, although interindividual variability was high. Motor cortical map volume was lower in acute LBP (F_1,70 = 5.61, P = .02). These findings demonstrate that acute LBP is characterized by lower sensorimotor cortical activity at the group level. However, individual variation was high, suggesting individual adaptation of cortical plasticity in acute pain. PERSPECTIVE: This is the first study to examine sensorimotor cortical activity in the acute stage of clinical LBP. This information is critical for understanding the neurophysiology of acute LBP.

[Sub-health status of middle school teachers and its correlation analysis with occupational stress]

Objective: To study the distribution of sub-health and occupational stress as well as their correlation among middle school teachers in Tianjin, then provide evidences for prevention and control of the status of sub-health. Methods: A total of 3 522 middle school teachers from six districts of Tianjin were recruited with stratified cluster sampling strategy for the investigation of Sub-Health Measurement Scale version 1.0 (SHMS V1.0) and Occupational Stress Inventory-Revised Edition (OSI-R) . Results: Detection rate of sub-health status among Tianjin middle school teachers was 58.55%. Men had significantly lower sub-health detection rate (55.19%) than women (59.71%) . Sub-health detection rate increased with age (P<0.05) , the sub-health detection rate among middle school teachers more than 50 years old was the highest (66.84%) . The mean score of OSI-R was 403.18±41.80 with the scores of 176.00±21.05, 103.17±17.53, and 124.02±20.28 for ORQ, PSQ, PRQ, respectively, which showed significantly difference compared with the occupational stress norm of China (P<0.001) . The mean scores of OSI-R, ORQ, PSQ, PRQ in different health status were significantly different (P<0.001) . The partial correlation analysis between the scores of sub-health and occupational stress of middle school teachers showed that the scores of occupational role and personal strain were negatively correlated with the scores of sub-health state (P< 0.001) , while, there was significantly positive correlation between the scores of personal resource and the scores of sub-health state (P<0.001) . Conclusion: Sub-health detection rate of middle school teachers in Tianjin is higher. Effective measures should be taken to appropriately mitigate the occupational stress level of middle school teachers, increase personal resources, and scientific and effective health guidance and education should be strengthened.

The role of psychosocial stress in the development of chronic musculoskeletal pain disorders: protocol for a systematic review and meta-analysis

BACKGROUND

Psychosocial factors play an important role in chronic musculoskeletal pain disorders. Although psychosocial stress is likely to contribute to the development of chronic musculoskeletal pain, investigations are limited to work-related stress or examination of specific conditions such as upper limb pain. The purpose of this review is to assess the evidence for an aetiological role of psychological stress in chronic musculoskeletal pain disorders.

METHODS

A systematic review and meta-analysis will be conducted. Electronic databases will be searched using predefined search terms to identify relevant studies. Data will be extracted by two independent reviewers, and disagreement will be resolved by a third reviewer. Only prospective longitudinal studies that assess psychosocial stress at baseline will be included. The population of interest will be inception cohorts or cohorts of people who have not yet developed chronic musculoskeletal pain disorders. The primary outcome measure will be the onset of chronic musculoskeletal pain.

DISCUSSION

To our knowledge, this review will be the first to systematically explore the available evidence on the aetiological role of psychosocial stress for the development of chronic musculoskeletal pain disorders. This review has the capacity to inform clinical practice on the importance of an early identification and, consequently, treatment of individuals who present with acute musculoskeletal disorders accompanied by a high level of stress.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017059949.

Safety and feasibility of transcranial direct current stimulation (tDCS) combined with sensorimotor retraining in chronic low back pain: a protocol for a pilot randomised controlled trial

INTRODUCTION

Chronic low back pain (LBP) is a common and costly health problem yet current treatments demonstrate at best, small effects. The concurrent application of treatments with synergistic clinical and mechanistic effects may improve outcomes in chronic LBP. This pilot trial aims to (1) determine the feasibility, safety and perceived patient response to a combined transcranial direct current stimulation (tDCS) and sensorimotor retraining intervention in chronic LBP and (2) provide data to support a sample size calculation for a fully powered trial should trends of effectiveness be present.

METHODS AND ANALYSIS

A pilot randomised, assessor and participant-blind, sham-controlled trial will be conducted. Eighty participants with chronic LBP will be randomly allocated to receive either (1) active tDCS + sensorimotor retraining or (2) sham tDCS + sensorimotor retraining. tDCS (active or sham) will be applied to the primary motor cortex for 20 min immediately prior to 60 min of supervised sensorimotor retraining twice per week for 10 weeks. Participants in both groups will complete home exercises three times per week. Feasibility, safety, pain, disability and pain system function will be assessed immediately before and after the 10-week intervention. Analysis of feasibility and safety will be performed using descriptive statistics. Statistical analyses will be conducted based on intention-to-treat and per protocol and will be used to determine trends for effectiveness.

ETHICS AND DISSEMINATION

Ethical approval has been gained from the institutional human research ethics committee (H10184). Written informed consent will be provided by all participants. Results from this pilot study will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12616000624482.

LITAF, HHEX, and DUSP1 expression in mesenchymal stem cells from patients with psoriasis

Psoriasis is a common chronic relapsing inflammatory skin disease, in which mesenchymal stem cells (MSCs) have been hypothesized to play an important role in abnormal localized inflammation and vascular proliferation observed in skin lesions. Previous studies have revealed abnormal gene expression patterns, DNA methylation status, and cytokine secretion of MSCs in psoriatic skin lesions, as well as some gene expression abnormalities related to inflammation and angiogenesis. We further verified the gene and protein expressions of inflammation-related lipopolysaccharide-induced tumor necrosis factor-alpha transcription factor (LITAF), dual-specificity protein phosphatase 1 (DUSP1), and angiogenesis-related hematopoietically expressed homeobox (HHEX) in MSCs derived from the skin lesions of psoriasis patients. The gene expression of LITAF, DUSP1, and HHEX in dermal MSCs was measured at the mRNA level using reverse transcription-polymerase chain reaction and the corresponding protein expression levels were analyzed by western blotting analysis. The gene and protein expression levels of LITAF, HHEX, and DUSP1 in dermal MSCs were significantly lower in psoriasis patients compared to controls. Amplification and western blotting results were consistent with our previously reported gene chip data. Our results suggest that dermal MSCs in psoriatic skin lesions may be involved in the development, progression, and regulation of localized inflammatory abnormalities by reducing the expression of LITAF, HHEX, and DUSP1, which are related to inflammation and angiogenesis.

Organisation and function of the primary motor cortex in chronic pain: protocol for a systematic review and meta-analysis

INTRODUCTION

Primary motor cortical (M1) adaptation in the form of altered organisation and function is hypothesised to underpin motor dysfunction observed in chronic pain. The aim of this review is to assess the evidence for altered M1 organisation and function in chronic pain.

METHODS AND ANALYSIS

Systematic review and meta-analysis. We will search electronic databases with predetermined search terms to identify relevant studies and evaluate the studies for inclusion and risks of bias. Two independent reviewers will extract data. Any disagreement will be resolved through a third reviewer. Cross-sectional or prospective studies published in English before May 2015 that investigate M1 organisation and function in chronic pain will be included if they meet the eligibility criteria. Primary outcomes will include M1 cortical excitability, spatial cortical representation, the function of inhibitory and facilitatory intracortical networks, cortical reactivity and cortical glucose metabolism. Clinical measures such as pain and disability will be included where the correlation with the primary outcomes of M1 organisation and function were investigated in the included studies.

ETHICS AND DISSEMINATION

This systematic review does not require ethical approval. The results of this review will be submitted for peer-reviewed publication regardless of outcome and will be presented at relevant conferences.

TRIAL REGISTRATION NUMBER

Our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42015014823).

Combined exercise and transcranial direct current stimulation intervention for knee osteoarthritis: protocol for a pilot randomised controlled trial

INTRODUCTION

Osteoarthritis (OA) is a major health problem and a leading cause of disability. The knee joint is commonly affected, resulting in pain and physical dysfunction. Exercise is considered the cornerstone of conservative management, yet meta-analyses indicate, at best, moderate effect sizes. Treatments that bolster the effects of exercise, such as transcranial direct current stimulation (tDCS), may improve outcomes in knee OA. The aims of this pilot study are to (1) determine the feasibility, safety and perceived patient response to a combined tDCS and exercise intervention in knee OA, and (2) provide data to support a sample size calculation for a fully-powered trial should trends of effectiveness be present.

METHODS AND ANALYSIS

A pilot randomised, assessor-blind and participant-blind, sham-controlled trial. 20 individuals with knee OA who report a pain score of 40 or more on a 100 mm visual analogue scale on walking, and meet a priori selection criteria will be randomly allocated to receive either: (1) active tDCS plus exercise, or (2) sham tDCS plus exercise. All participants will receive 20 min of either active or sham tDCS immediately prior to 30 min of supervised muscle strengthening exercise twice a week for 8 weeks. Participants in both groups will also complete unsupervised home exercises twice per week. Outcome measures of feasibility, safety, pain, disability and pain system function will be assessed immediately before and after the 8-week intervention. Analyses of feasibility and safety will be performed using descriptive statistics. Statistical analyses will be used to determine trends of effectiveness and will be based on intention-to-treat as well as per protocol.

ETHICS AND DISSEMINATION

This study was approved by the institutional ethics committee (H10184). Written informed consent will be obtained from all participants. The results of this study will be submitted for peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ANZCTR365331.

Liver cancer stem cells are selectively enriched by low-dose cisplatin

Accumulating evidence has indicated the importance of cancer stem cells in carcinogenesis. The goal of the present study was to determine the effect of low-dose cisplatin on enriched liver cancer stem cells (LCSCs). Human hepatoblastoma HepG2 cells were treated with concentrations of cisplatin ranging from 1 to 5 μg/mL. Cell survival and proliferation were evaluated using a tetrazolium dye (MTT) assay. LCSCs were identified using specific markers, namely aldehyde dehydrogenase-1 (ALDH1) and CD133. The percentage of ALDH1+ or CD133+ cells was examined by flow cytometric analysis. The expression of ALDH1 and/or CD133 in HepG2 cells was determined by immunocytochemical analysis. Low-dose cisplatin treatment significantly decreased cell survival in HepG2 cells after 24 or 72 h. However, the percentage of LCSCs in the surviving cells was greatly increased. The percentage of ALDH1+ or CD133+ cells was increased in a time- and dose-dependent manner after treatment with 1-4 μg/mL cisplatin, whereas 5 μg/mL cisplatin exposure slightly reduced the number of positive cells. These findings indicate that low-dose cisplatin treatment may efficiently enrich the LCSC population in HepG2 cells.

Prospective analysis of quality of life in elderly patients treated with adjuvant chemotherapy for non-small-cell lung cancer

BACKGROUND

Given the more comorbidities with a decline in physiologic reserve, it can be challenging to make appropriate treatment decisions in the elderly.

PATIENTS AND METHODS

Here, we prospectively evaluated and compared the health-related quality of life (HRQOL) of patients aged ≥ 65 with aged <65 who were treated with a postoperative chemotherapy for completely resected stage Ib, II or IIIa non-small-cell lung cancer (NSCLC). Either four cycles of paclitaxel (Taxol)-carboplatin (PC) or vinorelbine-cisplatin (NP) was used. The HRQOL was assessed with EORTC QLQ-C30 and EORTC QLQ-LC13.

RESULTS

Between October 2008 and October 2011, a total of 139 patients (aged <65, n = 73; ≥ 65, n = 66) were enrolled, and 127 (91.4%) completed the questionnaire. Overall, the quality of life (QOL) in elderly patients did not significantly deteriorate with adjuvant chemotherapy and the time trend of QOL in elderly patients was similar to that of younger patients. Although the elderly suffered from increased treatment-related adverse events involving sore mouth, peripheral neuropathy and alopecia compared with the baseline, the same time trends were also observed in younger group. The mean dose intensities (MDIs) for PC and NP regimen were not significantly different between the two age groups.

CONCLUSIONS

Postoperative chemotherapy did not substantially reduce HRQOL in elderly NSCLC patients, and HRQOL during and after adjuvant chemotherapy did not significantly differ by age.

Reductions in the effects of damping on stress concentration in premolars by post-endodontic restorations: a non-linear finite element study

The aim of this study was to measure the structural damping constants of premolars after treatment with a cast Co-Cr post-core system or permanent root filling, and to evaluate the stress damping effects of these restored premolars. Both the damping ratio and the natural frequency (NF) of the cast Co-Cr post-core restored premolars and the permanent root-filled premolars were detected by in-vitro NF testing experiments. Unprepared premolars served as the control. The damping constants beta of the samples were calculated from the measured damping ratios and natural frequencies. The measured damping constants beta of the test premolars were then used for dynamic finite element (FE) analyses. Stress contours and damping effects of stresses in each treated type of premolar were computed and compared using ANSYS. The measured damping constants beta were 0.75 x 10(-5) for the unprepared premolars, 0.69 x 10(-5) for the root-filled premolars with coronal restoration, and 0.72 x 10(-5) for the cast Co-Cr post-core restored premolars. The unprepared intact premolars demonstrated the highest stress dissipation effects with a ratio of 29.3 per cent at the middle root opposite to the loading side. However, no stress dissipation effects were found in the premolars that had been restored with the cast Co-Cr post-core system. The FE analysis showed that metallic post treatment attenuated the damping properties of the premolar. The effects of damping on stress concentration were significantly lower in restored premolars than in untreated vital premolars. These findings suggest that future research on post material should take the damping property into consideration.

Electronic structure of pyrochlore Cd(2)Re(2)O(7)

Detailed band structure calculations have been performed for Cd(2)Re(2)O(7) in high-, middle- and low-temperature (T) phases. The calculations are based on the observed lattice structures from x-ray diffraction measurements. The spin-orbit interaction is incorporated self-consistently in both the generalized gradient approximation (GGA) and the GGA plus Hubbard U (GGA+U) approaches. It is found that the on-site U has negligible effects on the Re 5d band structures; therefore both the GGA and GGA+U Re 5d band energies agree well with the observed O K-edge x-ray absorption spectroscopy (XAS) spectrum, whereas the Cd 4d band energy observed from photoemission spectroscopy can only be correctly reproduced by GGA+U calculations, indicating the relatively itinerant Re 5d and localized Cd 4d electrons. On the other hand, the spin-orbit coupling gives rise to nontrivial spin and orbital magnetic moments for the middle- T phase. Most unexpectedly, we found that the low- T phase exhibits quasi-two-dimensional Fermi surfaces. The calculated carrier numbers for the three phases are, at least qualitatively, consistent with the measured Hall coefficient.

Immunohistochemical diagnosis of mouse hepatitis virus and mycoplasma pulmonis infection with murine antiserum

This study established a modified alkaline phosphatase-labelled avidin-biotin-complex (ABC-AP) method for diagnosis of mouse hepatitis virus (MHV) and Mycoplasma pulmonis infection from formalin-fixed, paraffin wax-embedded sections, murine antibody-positive serum being used as the primary reagent. With this method, MHV antigen in cAnNCrj.Cg-Foxn1(nu)/Foxn1(nu) mice and M. pulmonis antigen in Wistar rats were immunolabelled in tissue sections. MHV antigen was clearly detected in samples of liver, stomach, caecal and colonic mucosa, and spleen. M. pulmonis antigen was demonstrated on the luminal surface of bronchiolar epithelial cells. This method may prove useful in diagnosis when commercial antisera are unavailable or when immunosuppression prevents serological diagnosis.

The sequence-specific DNA binding of NF-kappa B is reversibly regulated by the automodification reaction of poly (ADP-ribose) polymerase 1

Recent studies suggest that the synthesis of protein-bound ADP-ribose polymers catalyzed by poly(ADP-ribose) polymerase-1 (PARP-1) regulates eucaryotic gene expression, including the NF-kappaB-dependent pathway. Here, we report the molecular mechanism by which PARP-1 activates the sequence-specific binding of NF-kappaB to its oligodeoxynucleotide. We co-incubated pure recombinant human PARP-1 and the p50 subunit of NF-kappaB (NF-kappaB-p50) in the presence or absence of betaNAD+ in vitro. Electrophoretic mobility shift assays showed that, when PARP-1 was present, NF-kappaB-p50 DNA binding was dependent on the presence of betaNAD+. DNA binding by NF-kappaB-p50 was not efficient in the absence of betaNAD+. In fact, the binding was not efficient in the presence of 3-aminobenzamide (3-AB) either. Thus, we conclude that NF-kappaB-p50 DNA binding is protein-poly(ADP-ribosyl)ation dependent. Co-immunoprecipitation and immunoblot analysis revealed that PARP-1 physically interacts with NF-kappaB-p50 with high specificity in the absence of betaNAD+. Because NF-kB-p50 was not an efficient covalent target for poly(ADP-ribosyl)ation, our results are consistent with the conclusion that the auto-poly(ADP-ribosyl)ation reaction catalyzed by PARP-1 facilitates the binding of NF-kappaB-p50 to its DNA by inhibiting the specific protein.protein interactions between NF-kappaB-p50 and PARP-1. We also report the activation of NF-kappaB DNA binding by the automodification reaction of PARP-1 in cultured HeLa cells following exposure to H(2)O(2). In these experiments, preincubation of HeLa cells with 3-AB, prior to oxidative damage, strongly inhibited NF-kappaB activation in vivo as well.

Natural frequency analysis of periodontal conditions in human anterior teeth

The purpose of this study was to evaluate the possibility of using natural frequency (NF) analysis to detect the attachment loss of periodontal tissue. In this study, 698 anterior teeth were examined by a conventional probing method and also by NF analysis. The teeth were triggered to vibrate with an impulse hammer, and the vibrational response was detected by an acoustic sensor. Our results demonstrate no significant difference in NF values between the upper-lower/left-right quadrants of the tested teeth, although the mean natural frequency value of central incisors with periodontal disease was found to be 1.24 +/- 0.11 kHz which is significantly lower than that of teeth in a healthy condition (1.34 +/- 0.20kHz; p < 0.01). On the other hand, the mean frequency for periodontal disease involving canines (1.28 +/- 0.09 kHz) was also significantly lower than the corresponding value for healthy analogs (1.35 +/- 0.17 kHz; p < 0.05). These results suggest that NF analysis appears to be an effective method for assessing the periodontal condition of anterior teeth. Moreover, since this method is noninvasive, nondestructive, and necessitates minimal tooth contact, it can serve as an effective method for the early quantifiable testing and prevention of periodontal disease.

Cytotoxic flavonoids with isoprenoid groups from Morus mongolica

A new pyranoflavanone, sanggenol L (1), a Diels-Alder type adduct regarded as a cycloaddition product of a dehydrogeranylflavanone and a prenylchalcone, sanggenol M (2), along with four new 2-arylbenzofurans with isoprenoid units, mulberrofurans W-Z (3-6), were isolated together with 10 known flavonoids from Chinese Morus mongolica. The structures of these novel compounds were elucidated by spectroscopic methods. All flavanones investigated here showed higher cytotoxicity against human oral tumor cell lines (HSC-2 and HSG) than against normal human gingival fibroblasts (HGF). Among them, the cytotoxicity of compound 2 and the Diels-Alder type flavanone sanggenon C (7) isolated from Morus cathayana were the most potent. On the other hand, seven 2-arylbenzofurans exhibited lower cytotoxicity and tumor specificity as compared with flavanones.

Red blood cell osmotic fragility in chronically hemodialyzed patients

Chronic renal failure induces anemia and a short erythrocyte life span. Red blood cell (RBC) osmotic fragility is the resistance of RBC hemolysis to osmotic changes that is used to evaluate RBC friability. To find the cause of shortened red cell survival in uremic patients, we evaluated the RBC osmotic fragility in 57 chronic hemodialyzed patients. Each patient had received 12 h of dialysis per week continuously prior to being enrolled in the study. Nineteen healthy volunteers served as a control group. Biochemistry, hemoglobin, electrolyte, osmolarity, beta2-microglobulin, and intact parathyroid hormone were examined before and after the dialysis session. To evaluate the osmotic fragility of RBC, blood samples were collected in heparinized test tubes. Fifty microliters of the RBC of each individual was then incubated in solutions containing a series of various concentrations of NaCl ranging from 0 to 0.6%. The concentration of NaCl at which 50% of RBCs were lysed was considered the median osmotic fragility (MOF). The results showed that the MOF was significantly greater in hemodialyzed patients before dialysis than in the control group (0.41 +/- 0.03 vs. 0.39 +/- 0.02%). The osmotic resistance to hemolysis was also recorded after dialysis (MOF 0.38 +/- 0.03%). Correlation analysis showed that the MOF was significantly correlated with urea nitrogen, serum osmolarity, and intact parathyroid hormone level. In addition, the osmotic fragility was higher in patients who had a predialysis intact parathyroid hormone level > 100 pg/dl. In conclusion, hemodialysis can improve the osmotic fragility. The mechanism underlying this improvement may be the removal of low molecular weight uremic toxins, resulting in normalization of serum osmolarity. Our results indicate that parathyroid hormone is probably a major factor influencing RBC osmotic fragility in chronic renal failure.

Diagnosis and management of allergic fungal sinusitis with orbital involvement

PURPOSE

Allergic fungal sinusitis (AFS) is a noninvasive disease characterized by recurrent sinusitis. This condition is commonly treated with surgical debridement and several months of systemic corticosteroids. The treatment of AFS is examined in this study.

METHODS

A retrospective case series of three patients with AFS.

RESULTS

All three patients were treated with surgical debridement and less than one month of systemic corticosteroids. The patients then were treated with intranasal corticosteroids and monitored closely. Antifungal therapy was not used. All three patients remained disease-free during follow-up ranging from 12 months to 36 months.

CONCLUSIONS

Surgical debridement and systemic corticosteroids for less than four weeks followed by intranasal corticosteroids may provide long-term control of AFS. Additional study is recommended to examine further the optimal treatment for AFS.

The effects of two different cisplatin-based chemotherapy regimens on advanced non-small cell lung cancer

BACKGROUND

Many different cisplatin-based regimens have been used on advanced non-small cell lung cancer (NSCLC) in previous studies but there have been few such references in Taiwan. In this study, we evaluated the efficacy and toxicity of two different regimens including 5-Fluorouracil, Leucovorin, Etoposide and cisPlatin (FLEP) and cisPlatin, Etoposide and Mitomycin (PEM) in the treatment of patients with advanced NSCLC.

METHODS

We retrospectively analyzed the records of 44 patients with NSCLC who met the selection criteria from February 1995 through April 1998. All of them were confirmed, using histologic tests, that they were in advanced stages, i.e. stage IIIB or IV. Twenty-two patients received FLEP and 22 patients received PEM.

RESULTS

Three patients with FLEP therapy and 3 patients with PEM therapy had partial response. No patient had complete response. The response rate was 13.6% in both groups, respectively. The median survival was 160 +/- 30 (median + SD) days for patients with FLEP therapy and 263 +/- 104 days for patients with PEM therapy. The factors that were associated with longer survival in all patients included response (Stable Disease vs Disease Progression p = 0.004, Partial Response vs Disease Progression p = 0.047) and regimen of chemotherapy (PEM vs FLEP p = 0.008). The major clinically significant toxicity was myelosupression.

CONCLUSION

The responses to regimens, FLEP and PEM, were low in our study groups that might be due to the low dose of cisplatin and etoposide in our regimens. The patients with response to chemotherapy and PEM therapy had longer median survival than those who underwent FLEP therapy.

Periocular atypical mycobacterial infections

OBJECTIVE

To examine the clinical characteristics and management of periocular infections caused by atypical mycobacteria.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

Six patients were identified with periocular atypical mycobacterial infections: four with Mycobacterium chelonae and two with Mycobacterium fortuitum.

INTERVENTION

The treatment of these infections included removal of the foreign bodies with debridement of the lesions. Specimens were sent for histopathologic examination, routine cultures, and fresh tissue for culture after homogenization.

MAIN OUTCOME MEASURES

A retrospective review of culture-proven atypical mycobacterial infections involving the periocular tissues was performed. Charts were reviewed for age, gender, infectious organism, medical history, surgical history, presenting symptoms, clinical features, and treatment.

RESULTS

Four associations with infection were identified in these patients: immunosuppression, nasolacrimal duct obstruction, the presence of a foreign body, and a history of recent surgery. All six of the patients had at least one of these associations and five of the patients had at least two. Clinical characteristics that may distinguish atypical mycobacterial infections from acute bacterial infections include subacute presentation, firm nodular lesions, mild erythema, mild tenderness, and minimal purulent discharge. All patients had resolution of their infections after debridement and several weeks of systemic antibiotic therapy guided by susceptibility testing.

CONCLUSIONS

Periocular atypical mycobacterial infections are uncommon. The clinical history and examination can raise the suspicion of this infection by revealing the clinical characteristics of these infections. Treatment includes removal of foreign bodies, debridement, and long-term systemic antibiotic therapy.

Skeletal muscle contractions stimulate cGMP formation and attenuate vascular smooth muscle myosin phosphorylation via nitric oxide

Nitric oxide generated by neuronal nitric oxide synthase in contracting skeletal muscle fibers may regulate vascular relaxation via a cGMP-mediated pathway. Neuronal nitric oxide synthase content is greatly reduced in skeletal muscles from mdx mice. cGMP formation increased in contracting extensor digitorum longus muscles in vitro from C57 control, but not mdx mice. The increase in cGMP content was abolished with NG-nitro-L-arginine. Sodium nitroprusside treatment increased cGMP levels in muscles from both C57 and mdx mice. Skeletal muscle contractions also inhibited phenylephrine-induced phosphorylation of smooth muscle myosin regulatory light chain. Arteriolar dilation was attenuated in contracting muscles from mdx but not C57 mice. NO generated in contracting skeletal muscle may contribute to vasodilation in response to exercise.

Delay of estradiol-induced surge secretion of LH in gilts by intracerebroventricular injection of morphine

In Experiment 1, ovariectomized (OVX) gilts, 143 d old and 58.5 +/- 1.8 kg BW, received 10 micrograms estradiol benzoate (EB)/kg BW i.m. and either 500 micrograms of the endogenous opioid peptide (EOP) agonist, morphine (MOR), in saline (SAL; n = 5), or SAL (n = 4) intracerebro-ventricularly at 40 and 48 hr after EB. With the exception of one MOR-treated gilt, which was deleted from Experiment 1, LH secretion was suppressed for at least 50 hr in all gilts. Timing of the LH surge was similar among gilts. However, total LH secreted was greater (P < 0.05) after SAL than MOR. The experiment was repeated at 179 d of age and 78.6 +/- 1.2 kg BW, except that treatments were reversed among gilts. Emergence of the LH surge was delayed (P < 0.005) by 10.8 hr and time to maximum LH concentration (P < 0.05) by 6.8 hr after MOR than after SAL. Magnitude and total LH secreted were not different among gilts. In Experiment 2, gilts which had displayed estrous cycles of 18-22 d were OVX and treated as in Experiment 1, except MOR (n = 3) or SAL (n = 4) were injected 10 hr later than in Experiment 1, i.e., at 50 and 58 hr after EB. Secretion of LH was suppressed for at least 60 hr in both groups. Time to emergence of the LH surge was delayed by 27 hr (P < 0.05) after MOR compared to after SAL. However, other parameters of the surge were not different among gilts. Thus, EOP modulate LH surge secretion negatively in the pig.

A color Doppler analysis of nifedipine-induced posterior ocular blood flow changes in open-angle glaucoma

PURPOSE

This pilot study used color Doppler imaging to investigate the effects of nifedipine on the posterior ocular blood flow of patients with glaucoma progression at normal intraocular pressures.

PATIENTS AND METHODS

Eighteen patients, 11 men and seven women with a median age of 61.7 years, were imaged before and 6 weeks after the initiation of 30 mg of sustained-release nifedipine (Procardia XL; produced by either Pfizer or Pratt) daily.

RESULTS

There was no statistically significant change in the blood velocity of the ophthalmic artery, central retinal artery, and main nasal and temporal short posterior ciliary arteries after treatment with nifedipine.

CONCLUSION

The routine use of nifedipine in patients with normal tension glaucoma progression is not supported by this study.

Plasma spraying of zirconia-reinforced hydroxyapatite composite coatings on titanium: part II: dissolution behaviour in simulated body fluid and bonding degradation

The change of phase, morphology and bond strength of plasma sprayed hydroxyapatite (HA) coating and ZrO2/HA composite coatings immersed in simulated body fluid (SBF) for various periods of time was studied. X-ray diffractometry (XRD) and scanning electron microscopy (SEM) were used to identify the phase and observe the morphology of the coating surface before and after immersion. In addition, inductively coupled plasma emission spectroscopy (ICP) was used to measure the ion release rate of coatings in SBF for various periods of time. Observation of the morphology by SEM shows that the composite coating with the addition of ZrO2 in HA significantly reduced the dissolution rate of impurity phases in simulated body fluid. The argument was supported by measurement of Ca2+ ion concentration in SBF. During plasma spraying, less OH- ions were lost in a ZrO2-containing composite coating. This factor, together with the reduced effective surface of the ZrO2-containing HA coating, were attributed to the reduced dissolution rate of the composite coatings. All the plasma sprayed coatings degraded after immersion in SBF owing to dissolution of constituents in the coating, however, the addition of ZrO2 in HA improved the bonding strength of HA coating after immersion in SBF.

Plasma spraying of zirconia-reinforced hydroxyapatite composite coatings on titanium: part I: phase, microstructure and bonding strength

Plasma-sprayed hydroxyapatite (HA) coatings applied to metal substrates can induce a direct chemical bond with bone and hence achieve biological fixation of the implant. However, the poor bonding strength between HA and substrate has been of concern to orthopaedists. In this study, two submicrometre ZrO2 powders stabilized with both 3 and 8 mol% Y2O3 (TZ3Y and TZ8Y, respectively) were incorporated in a plasma-sprayed HA coating on Ti-6Al-4V substrate to investigate the change in phase, microstructure and bonding strength. The results show that ZrO2 composite coatings contain more unmelted particles and greater porosity. During plasma spraying, ZrO2 reacts with the CaO in HA to form CaZrO3 and accelerates HA decomposition to alpha-TCP and Ca4P2O9. Nevertheless, bonding strength increases with increase of ZrO2 content in the range 0 to 10 wt% studied. The higher Y2O3-containing TZ8Y apparently exerts a greater strengthening effect than the lower Y2O3-containing TZ3Y.