The impact of expectancy on the efficacy of acupuncture treatment for postprandial distress syndrome: Secondary analysis of a randomized clinical trial

BACKGROUND

Expectancy is an important source of the placebo effect. However, it is unclear whether this has an effect on the efficacy of acupuncture and sham acupuncture in the treatment of postprandial distress syndrome (PDS).

AIM

To evaluate the effects of high expectancy (HE) and low expectancy (LE) on the efficacy of acupuncture and sham acupuncture in the treatment of PDS.

METHODS

This post hoc secondary analysis used data from our previous randomized controlled trial. Patients were, respectively, enrolled in the HE group and LE group according to expectancy assessments. The composite primary outcomes were the response rate and the elimination rate after 4 weeks of treatment. Expectancy was considered a factor affecting the efficacy of acupuncture treatment only if both primary outcomes achieved significance.

RESULTS

For the acupuncture group, the response rate was 84.5% in the HE group and 78.8% in the LE group (p = 0.458), and the elimination rate was 32.1% in the HE group and 21.2% in the LE group (p = 0.241). For the sham acupuncture group, the response rate at week 4 was 52.3% in the HE group and 53.1% in the LE group (p = 0.936), and the elimination rate at week 4 was 23.1% in the HE group and 10.6% in the LE group (p = 0.090).

CONCLUSION

In this study, the response rate and elimination rate were higher in the high-expectancy group, but no conclusive evidence was found for an association between expectancy and the efficacy of acupuncture and sham acupuncture.

Acupuncture for the Treatment of Diarrhea-Predominant Irritable Bowel Syndrome: A Pilot Randomized Clinical Trial

IMPORTANCE

Acupuncture is a promising therapy for irritable bowel syndrome (IBS), but the use of subjective scales as an assessment is accompanied by high placebo response rates.

OBJECTIVES

To preliminarily test the feasibility of using US Food and Drug Administration (FDA)-recommended end points to evaluate the efficacy of acupuncture in the treatment of IBS.

DESIGN, SETTING, AND PARTICIPANTS

This pilot, multicenter randomized clinical trial was conducted in 4 tertiary hospitals in China from July 1, 2020, to March 31, 2021, and 14-week data collection was completed in March 2021. Individuals with a diagnosis of IBS with diarrhea (IBS-D) were randomized to 1 of 3 groups, including 2 acupuncture groups (specific acupoints [SA] and nonspecific acupoints [NSA]) and a sham acupuncture group (non-acupoints [NA]) with a 1:1:1 ratio.

INTERVENTIONS

Patients in all groups received twelve 30-minute sessions over 4 consecutive weeks at 3 sessions per week (ideally every other day).

MAIN OUTCOMES AND MEASURES

The primary outcome was the response rate at week 4, which was defined as the proportion of patients whose worst abdominal pain score (score range, 0-10, with 0 indicating no pain and 10 indicating unbearable severe pain) decreased by at least 30% and the number of type 6 or 7 stool days decreased by 50% or greater.

RESULTS

Ninety patients (54 male [60.0%]; mean [SD] age, 34.5 [11.3] years) were enrolled, with 30 patients in each group. There were substantial improvements in the primary outcomes for all groups (composite response rates of 46.7% [95% CI, 28.8%-65.4%] in the SA group, 46.7% [95% CI, 28.8%-65.4%] in the NSA group, and 26.7% [95% CI, 13.0%-46.2%] in the NA group), although the difference between them was not statistically significant (P = .18). The response rates of adequate relief at week 4 were 64.3% (95% CI, 44.1%-80.7%) in the SA group, 62.1% (95% CI, 42.4%-78.7%) in the NSA group, and 55.2% (95% CI, 36.0%-73.0%) in the NA group (P = .76). Adverse events were reported in 2 patients (6.7%) in the SA group and 3 patients (10%) in NSA or NA group.

CONCLUSIONS AND RELEVANCE

In this pilot randomized clinical trial, acupuncture in both the SA and NSA groups showed clinically meaningful improvement in IBS-D symptoms, although there were no significant differences among the 3 groups. These findings suggest that acupuncture is feasible and safe; a larger, sufficiently powered trial is needed to accurately assess efficacy.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2000030670.

[Application of "patient and public involvement" in acupuncture clinical research]

In order to explore the application of "patient and public involvement" (PPI) in acupuncture clinical research, the connotation, reporting standards and research status of PPI at home and abroad are collated, and the key problems of PPI encountered in acupuncture clinical research are deeply considered and summarized. It is suggested that the short-form checklist of the Guidance for Reporting Involvement of Patients and the Public (GRIPP) of the 2nd edition should be applied to acupuncture clinical research. PPI provides a new perspective for acupuncture clinical research. It is beneficial for each stage of research, contributes to the improvement of acupuncture medical service mode and increases the success rate and cost-effectiveness of research so that the innovation and development of acupuncture science can be promoted.

[Research progress of acupuncture for peripheral inflammatory response]

Acupuncture can regulate peripheral inflammatory response mainly through somatosensory-vagal/sympathetic nerve-splenic/adrenal/local reflex pathway. Besides, acupuncture may also play an anti-inflammatory role through gut microbiota and neuro-endocrine pathway. The effects of acupuncture have acupoint specificity and time window effect, and are influenced by voltage, current and frequency of electroacupuncture. Future research should focus on the connection and interaction of multiple targets, pathways and mechanisms in the brain, and clarify the multi-target advantages of acupuncture anti-inflammatory.

Effect of acupuncture for diarrhea-predominant irritable bowel syndrome: study protocol for a randomized clinical trial

Background

Diarrhea-predominant irritable bowel syndrome (IBS-D) is the most common subtype of IBS. Acupuncture is commonly used to treat IBS-D, but its effect is uncertain because of the poor quality of prior studies. This trial aims to evaluate the efficacy and safety of acupuncture treatment for IBS-D through comparisons with sham acupuncture.

Methods/design

This is a large-scale, multi-center, randomized, two-arm interventional clinical trial. Participants will take part in a total of 20 weeks of study, which contained 3 phases: 2-week screening, 6-week treatment, and 12-week follow-up. Based on the composite response rate of the primary endpoint in our pilot study (a sham acupuncture response rate of 27% and a true acupuncture of approximately 45%), 280 randomly allocated participants were planned. Eligible participants will be randomly assigned to the true acupuncture group and sham acupuncture group according to a ratio of 1:1, and a total of 15 sessions of treatment overall 6-week treatment period will be brought. The primary endpoint is a composite response rate at week 6, and the responder is defined as who responses in both abdominal pain intensity and stool consistency. Furthermore, composite response rates at other weeks, IBS Symptom Severity Scale, IBS Quality of Life, Adequate Relief scale, and individual IBS symptoms (abdominal pain, bloating, stool frequency) are chosen as secondary endpoints.

Discussion

This trial may provide high-quality evidence for the efficacy and safety of acupuncture in the treatment of IBS-D. The results of this study will be published in peer-reviewed journals.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2100044762. Registered on 26 March 2021.

[Research progress on mechanism of acupuncture and moxibustion in treatment of irritable bowel syndrome]

The current clinical evidence and underlying mechanisms of acupuncture and moxibustion in the treatment of irritable bowel syndrome (IBS) were summarized, so as to better optimize clinical treatment. The relevant articles of acupuncture and moxibustion in the treatment of IBS in recent years were retrieved and summarized. We found that the clinical efficacy of acupuncture and moxibustion in the treatment of IBS was relatively reliable. However, the mutual relationships among various mechanisms of action such as abnormal gastrointestinal motility, high visceral sensitivity, intestinal microenvironment disorders, and abnormal intestinal-brain interactions need to be further explored. The authors believe that in-depth explorations of the bidirectional regulation of "gut-brain axis", the law of changes in the abundance and diversity of intestinal flora, and the establishment of a more ideal animal model of TCM syndrome differentiation are useful ideas for subsequent research.

Potential Mechanisms of Acupuncture for Functional Dyspepsia Based on Pathophysiology

Functional dyspepsia (FD), a common disorder of gastrointestinal function, originated from the gastroduodenum. Although the therapeutic effect of acupuncture has been investigated by various high-quality randomized controlled trials, the potential mechanisms showed obvious heterogeneity. This review summarized the potential mechanisms of acupuncture on FD in order to guide for future laboratory and clinical studies. Here, we argued that the primary cause of FD was gastroduodenal low-grade inflammation and acid exposure, which impaired mucosal integrity, caused brain-gut axis dysfunction, and impaired brain network connectivity, all of which generated various symptom patterns. Overall the clinical studies indicated that acupuncture was a promising treatment to alleviate symptoms in FD patients, whose efficacy was influenced by acupoints and individual variance. Mechanistically, studies with animal models of FD and patients have shown that acupuncture, a non-invasive strategy for nerve stimulation, may have the potential to control intestinal inflammation and suppress acid-secretion via different somatic autonomic reflex pathways, regulate the brain-gut axis through intestinal microbiota, and has the potential to ameliorate FD-symptoms. The cumulative evidence demonstrated that acupuncture is a promising treatment to alleviate symptoms of FD patients.

Is acupuncture effective for knee osteoarthritis? A protocol for a systematic review and meta-analysis

INTRODUCTION

Knee osteoarthritis (KOA) is one of the leading causes of disability. The effectiveness of acupuncture for treating KOA remains controversial. This protocol describes the method of a systematic review and meta-analysis evaluating the effectiveness and safety of acupuncture for treating KOA.

METHODS AND ANALYSIS

Four English databases (PubMed, Embase, Cochrane Library databases and Web of Science) and four Chinese databases (China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP Database for Chinese Technical Periodicals, and Wanfang) will be searched from the database inception to 1 September 2021. All randomised controlled trials related to acupuncture for KOA will be included. Extracted data will include publication details, basic information, demographic data, intervention details and patient outcomes. The primary outcome will be pain intensity. Risk of bias will be assessed using the Cochrane Collaboration's tool for assessing risk of bias. Article selection, data extraction and risk of bias assessment will be performed in duplicate by two independent reviewers. If the meta-analysis is precluded, we will conduct a descriptive synthesis using a best-evidence synthesis approach. The strength of recommendations and quality of evidence will be assessed using the Grading of Recommendations Assessment Development and Evaluation working group methodology.

ETHICS AND DISSEMINATION

Ethics approval is not required because individual patient data are not included. This protocol was registered in the international Prospective Register of Systematic Reviews on 25 February 2021. The systematic review and meta-analysis will be submitted for publication in a peer-reviewed journal. The findings will also be disseminated through conference presentations.

TRIAL REGISTRATION NUMBER

CRD42021232177.

[Optimization and implementation of clinical trial of acupuncture: reflection on the successful case of acupuncture for postprandial distress syndrome]

Taking the clinical trial of acupuncture in treatment of postprandial distress syndrome as an example, this paper proposes that the acupuncture clinical trial protocol should be optimized in view of acupuncture prescription, acupuncture frequency and outcomes. Besides, the data quality of acupuncture clinical trial should be improved in consideration of data sharing and electronic data capture so as to provide a reference for the majority of researchers to optimize and implement acupuncture clinical trial.

Electroacupuncture for postoperative ileus after laparoscopic surgery on colorectal cancer: study protocol for a randomized controlled trial

Background

Postoperative ileus (POI) occurs in almost all patients after abdominal laparoscopic surgery, resulting in complications and increasing the length of hospitalization. Electroacupuncture has been used as an alternative therapy for gastrointestinal dysfunction, but its efficacy for POI is inconclusive. The study is designed to determine whether electroacupuncture can accelerate recovery from POI.

Methods/design

This study is a three-arm, randomized controlled trial. A total of 105 patients will be randomized into a group receiving electroacupuncture at Tianshu (ST25), a group receiving electroacupuncture at Zusanli (ST36), or a control group in a 1:1:1 ratio. Patients in the electroacupuncture groups will receive electroacupuncture treatment for 4 days from the first day after surgery. The primary outcome consists of the time to first flatus and the time to first defecation. Secondary outcomes include the time to first tolerance of liquid and semiliquid food; the length of the hospital stay; postoperative pain, nausea, and vomiting; abdominal distension; the time to first get out of bed; and postoperative complications. The outcomes will be assessed by the patients themselves every day during hospitalization. Surgeons, nurses, assessors, and statisticians will be blinded to the group assignments. Patients in the two electroacupuncture groups, but not in the control group, will be blinded to the group assignments. The acupuncturists will not be blinded.

Discussion

The aim of this trial is to provide a nonpharmacological therapy for POI and may provide evidence of the effect of electroacupuncture at ST25 or ST36 on POI.

Trial registration

Chinese Clinical Trial Registry ChiCTR1900027466. Registered on 14 November 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05564-3.

Standardizing and optimizing acupuncture treatment for irritable bowel syndrome: A Delphi expert consensus study

BACKGROUND

Acupuncture has been widely utilized for irritable bowel syndrome (IBS). However, heterogeneity is large among therapeutic strategies and protocols. The aim of this study was to propose some down-to-earth recommendations and establish an optimized protocol for acupuncture practice in IBS.

METHODS

A panel of 74 traditional Chinese medicine (TCM) acupuncturists participated in clinical issue investigation. Subsequently, systematic reviews concerning acupuncture for IBS were screened within 3 databases. An initial consensus questionnaire was formed from the results of clinical issue investigation and literature review. Ultimately, a Delphi vote was carried out to determine these issues. 30 authoritative experts with extensive experience were requested to respond with agreement, neutrality, or disagreement for the items. Consensus achievement on a given item was defined as greater than 80% agreement.

RESULTS

Following a 2-round Delphi survey, there were 19 items reaching consensus; of which 5 items (26.32%) achieved thorough consensus, and significant agreement was reached for the other 14 items. These items can be classified into the 3 major domains: 1) clinical outcomes that acupuncture can bring for favorable intervention population (5 items), 2) suitable therapeutic principles and parameters of acupuncture (13 items), 3) possible adverse events in the treatment (1 item).

CONCLUSION

Without any ready-made guidelines and lacking of homogeneity in the published literatures, such expert consensus could be valuable for TCM acupuncturists in daily practice and patients with IBS to obtain appropriate and standardized acupuncture treatment. In addition, it also points out the clinical focus which need to be further explored in future trials.

[Improvement in dyspepsia related symptoms treated with acupuncture in 278 patients with postprandial distress syndrome: a secondary analysis of a multi-center randomized controlled trial]

OBJECTIVE

To evaluate the clinical effect of acupuncture for the improvements in various dyspeptic symptoms of postprandial distress syndrome.

METHODS

The secondary analysis on the data of a multi-center randomized controlled trial (RCT) was conducted. 278 patients with postprandial distress syndrome were randomized into an acupuncture group (138 cases) and a sham-acupuncture group (140 cases). In the acupuncture group, acupuncture was applied to Baihui (GV 20), Danzhong (CV 17), Zhongwan (CV 12), Qihai (CV 6), Neiguan (PC 6), Zusanli (ST 36), etc. In the sham-acupuncture group, 6 sites, neither located on meridians nor belonged to meridian acupoints, were selected and punctured shallowly. The duration of treatment was 20 min each time, 3 times a week, for 4 weeks totally in the two groups. The follow-up visit lasted for 12 weeks. The scores of dyspeptic symptoms were compared between the two groups before treatment, during treatment (in week 1, 2, 3 and 4) and during follow-up (in week 8, 12 and 16) separately.

RESULTS

Besides the scores of early satiety and vomiting in the sham-acupuncture group in week 1, the scores of the other dyspepsia symptoms during treatment and follow-up were all reduced in the two groups as compared with those before treatment (P<0.05). In week 2 and 3, the score of early satiety in the acupuncture group was lower than that in the sham-acupuncture group (P<0.05). In week 3, the scores of postprandial fullness, upper abdominal bloating and belching in the acupuncture group were lower than those in the sham-acupuncture group (P<0.05). In week 4 and during follow-up, the scores of postprandial fullness, early satiety, upper abdominal bloating and belching in the acupuncture group were all lower than those in the sham-acupuncture group (P<0.05).

CONCLUSION

Acupuncture remarkably relieves postprandial fullness, early satiety, upper abdominal bloating and belching in patients with postprandial distress syndrome.

Acupuncture for the treatment of diarrheal-predominant irritable bowel syndrome: study protocol for a pilot randomized controlled trial

BACKGROUND

Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal diseases. Although acupuncture has become a common alternative therapy for IBS, there is insufficient evidence for its effectiveness. This study was designed to assess the efficacy and feasibility of acupuncture in the treatment of IBS.

METHODS/DESIGN

This is a multicenter randomized controlled clinical trial. According to the ratio of 1:1:1, 90 patients with irritable bowel syndrome will be randomly divided into specific acupoints (SA) group, non-specific acupoints (NSA) group, and non-acupoints (NA) group. All patients will be treated with acupuncture 12 times within 4 weeks and followed up for 8 weeks. The primary outcome is the response rate, the percentage of patients whose average value of worst abdominal pain is 30% better and the days of loose stool is 50% less than the baseline, at week 4 after randomization. The secondary outcomes include the response rates at other time points, IBS Symptom Severity Scale (IBS-SSS), Patient Health Questionnaire-9 depression scale (PHQ-9), IBS-Quality of Life scale (IBS-QOL), IBS Adequate Relief (IBS-AR), Abdominal Pain Score, Abdominal Bloating Score, Bristol Stool Score (BBS), blinding assessment, and credibility evaluation. Adverse events will be monitored and recorded during the trial.

TRIAL REGISTRATION

Chictr.org.cn ChiCTR2000030670. Registered on 9 March 2020.

[Current status of registered drug and vaccine pediatric clinical trials in China]

Objective: To evaluate the current status of the registered pediatric drug or vaccine clinical trials in China for the purpose of providing a reference for the development of pediatric clinical trials in China. Methods: We collected the data about registered pediatric clinical trials that were conducted from September 6, 2013(Mandatory registration start date) to September 6, 2019 (Cut-off date) at Chinadrugtrials.org.cn platform. The survey items included trial name and number, drug classification, sponsor's information, current trial status, completion status, etc. The clinical trials were categorized by drug group (includes chemical medicine, traditional Chinese medicine and natural medicine, biological products) and by vaccine group. Results: During the six years 349 pediatric clinical trials were registered on the platform, including 162 pediatric drug trials and 187 vaccine trials. The numbers of chemical drugs and biological products registered in 2018 were 23 and 11, respectively, the highest in the history. The number of pediatric clinical trials of traditional Chinese medicine and natural medicine was 11 in 2014, but from 2015 to 2018 only 2 to 4 trials were registered each year. The overall completion rates of the registered drug and vaccine clinical trials were 22.8% (37/162) and 41.7%(78/187), respectively. Only 42 international multicenter pediatric clinical trial projects were registered on the platform. The numbers of drug and vaccine phase Ⅰ clinical trials were 4 and 46, respectively. Thirty-six pediatric endocrine system agent clinical trials were carried out, with the largest number of all the drug categories registered on the platform. Conclusions: In recent years the number of registered pediatric drug and vaccine clinical trials increased in China. However, the number is still very limited. It is urgent to further promote the development of pediatric clinical trials.

Electroacupuncture ameliorates intestinal inflammation by activating α7nAChR-mediated JAK2/STAT3 signaling pathway in postoperative ileus

Inflammatory cytokines produced by muscularis macrophages largely contribute to the pathological signs of postoperative ileus (POI). Electroacupuncture (EA) can suppress inflammation, mainly or partly via activation of vagal efferent. The goal of this study was to investigate the mechanisms by which EA stimulation at an hindlimb region ameliorates inflammation in POI.

Methods: Intestinal motility and inflammation were examined after 24 h after intestinal manipulation (IM)-induced POI in mice. Local immune response in the intestinal muscularis, expression of macrophages, α7 nicotinic acetylcholine receptor (α7nAChR), Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) were determined by flow cytometry, Western Blot, qPCR and immunofluorescence. The effects of α7nAChR antagonists (methyllycaconitine and α-bungarotoxin) and JAK2/STAT3 inhibitors (AG490 and WP1066) were also administered in a subset of mice prior to EA. In the parasympathetic pathways, intestinal motility and inflammation were determined after cervical vagotomy and sub-diaphragmatic vagotomy. The expression of gamma absorptiometry aminobutyric acid (GABA_A) receptor in dorsal motor nucleus of vagal (DMV) cholinergic neurons was assessed by immunofluorescence and the response to DMV microinjection of bicuculine (antagonist of GABA_A receptor) or muscimol (agonist of GABA_A receptor) were assessed.

Results: EA suppressed intestinal inflammation and promoted gastrointestinal motility. Mechanistically, EA activated the α7nAChR-mediated JAK2/STAT3 signaling pathway in macrophages which reduced the production of inflammatory cytokines. Furthermore, we also demonstrated that hindlimb region stimulation drove vagal efferent output by inhibiting the expression of GABA_A receptor in DMV to ameliorate inflammation.

Conclusions: The present study revealed that EA of hindlimb regions inhibited the expression of GABA_A receptor in DMV neurons, whose excited vagal nerve, in turn suppressed IM-induced inflammation via activation of α7nAChR-mediated JAK2/STAT3 signaling pathway.

[Construction of swept source optical coherence tomography imaging system for root canal endoscopy and application in diagnosis of root fractures]

OBJECTIVE

To construct swept source optical coherence tomography (SS-OCT) imaging system for root canal endoscopy, and to evaluate the accuracy of diagnosing artificial root fractures.

METHODS

An ultra-high-speed (40 kHz) swept laser source was developed based on the piezoelectric tuning filter and the Fourier domain mode locking (FDML) swept laser technology (patent number: 200620135940.2). Ultra-miniature gradient index lens technology (patent number: 201320241218.7) was used to create a thin endoscopic probe with a diameter of 0.86 mm for real-time image transmission. The SS-OCT light source had a wavelength of 1 310 nm and a bandwidth of 100 nm. The axial and transverse image resolutions were 15 μm and 25 μm, respectively. Artificial fractures were created on human mandibular premolars with single root and the premolar roots were prepared to 41 horizontal sections (1 mm thick). 27 root sections with fractures (width: 52-284 μm) and 14 the sections without fractures were observed under an optical stereomicroscope with a cold light source as the gold standard. The horizontal root sections were scanned by self-developed SS-OCT imaging system for root canal endoscopy with a central wavelength of 1 310 nm and bandwidth of 100 nm. The data were reconstructed with 30 μm thick slices at an interval of 30 μm. Two observers, a radiologist and an endodontist, were trained and independently evaluated all the reconstructed images blindly. The diagnostic performance of SS-OCT imaging system was calculated, and statistical analysis was performed.

RESULTS

SS-OCT root canal endoscopic imaging system composed of high-speed swept laser source, fiber coupler, endoscopic probe, reference arm and differential detector. Root sections could be scanned by SS-OCT and imaged in realtime at a depth of 1 to 2 mm. The kappa value for interobserver agreement was 0.792, and the intraobserver agreement was 1.000 and 0.709 for two observers respectively. All of 27 fractured root sections and 12 of 14 root sections without fractures were accurately diagnosed while 2 unfractured root sections were misdiagnosed. The sensitivity was 1.000 and the specificity was 0.857 for diagnosis of artificial root fractures by SS-OCT. The positive predictive value (PPV), negative predictive value (NPV) and the overall accuracy rate were 0.931, 1.000 and 0.951 respectively.

CONCLUSION

The swept source optical coherence tomography imaging system for root canal endoscopy is a promising imaging method for observing root fractures．.

[Detection of root cracks after root canal preparation using rotary NiTi systems by optical coherence tomography (OCT) scan]

OBJECTIVE

To evaluate the accuracy of optical coherence tomography (OCT) in detecting root cracks after root canal instrumentation using histological gold standard.

METHODS

Twenty complete extracted human mandibular incisors that were free of caries, calculus, and root treatment were chosen and accessed coronally with a diamond bur, then mounted in resin blocks with alginate impression material using simulated periodontal ligaments, and the apex was exposed 3 mm. The teeth were stored in water at room temperature. Then the teeth were then instrumented to the major apical foramen (AF) at #30/0.09 using ProTaper Universal rotary nickel titanium system (Dentsply Maillefer, Ballaigues, Switzerland), irrigation with 1% sodium hypochlorite (NaOCl) by using a 26-gauge needle followed after each instrument. The apical root was scanned with 360° of rotation by Swept-Source Optical Coherence Tomography (SS-OCT) (wavelength: 1 310 nm, scan rate: 20 kHz, axial resolution: 16 μm) with driving device (stepper motor and lifting platform). The reconstruction images of axial planes 1, 2 and 3 mm from the apex were examined and the root cracks were blindly diagnosed by two observers. The horizontal section was performed at 1, 2 and 3 mm from the apex using low speed disc saw (Leica SP1600, Wetzlar, Germany). The presence of cracks was noted under an optical stereomicroscope (ZOOM-630E) with a cold light source using as gold standard to evaluate the accuracy of OCT in detecting root cracks after root canal instrumentation.

RESULTS

After canals instrumentation with ProTaper Universal rotary nickel titanium system to #30/0.09, root cracks were detected in 9 of 20 teeth by histological examination. Crack lines were observed on 13 of 60 horizontal sections and cracks on 12 of the 13 sections were detected by OCT. No cracks were observed in the other 47 of the 60 horizontal sections,none of which was misdiagnosed by OCT. The overall accuracy rate for detection of root cracks with OCT was 0.983, the sensitivity was 0.923, the specificity was 1.000, the positive predictive value (PPV) was 1.000 and the negative predictive value (NPV) was 0.979.

CONCLUSION

OCT may be a promising nondestructive imaging method for diagnosing root canal cracks after canal instrumentation.

In vivo distribution of opioid receptors in man in relation to the cortical projections of the medial and lateral pain systems measured with positron emission tomography

In vivo opioid receptor binding in the cortical projections of the medial (cingulate and prefrontal cortex) and lateral pain system (primary somatosensory cortex) in male volunteers has been quantitated using [11C]diprenorphine and positron emission tomography. High levels of opioid receptor binding were seen in the cortical projections of the medial pain system in the cingulate and prefrontal cortex as has previously been observed in post-mortem studies. However, a focal reduction of opioid receptor binding was observed and quantitated in the primary motor/sensory strip when compared to surrounding parietal cortex. This new finding suggests that the medial pain system is likely to be more susceptible to exogenous and endogenous opioid neuromodulation than the so-called lateral pain system.

Cortical and subcortical localization of response to pain in man using positron emission tomography

A quantitative study of the regional cerebral responses to non-painful and painful thermal stimuli in six normal volunteers has been done by monitoring serial measurements of regional blood flow measured by positron emission tomography (PET). In comparison to a baseline of warm stimulation no statistically significant changes in blood flow were seen in relation to increasing non-painful heat. However, highly significant increases in blood flow were seen in response to painful heat in comparison to non-painful heat. These changes were in the contralateral cingulate cortex, thalamus and lenticular nucleus. These findings are discussed in relation to previous physiological observations of responses to nociceptive stimuli in man and primates.