Mindfulness-based online intervention on mental health among undergraduate nursing students during coronavirus disease 2019 pandemic in Beijing, China: A randomized controlled trial.

Objective: To evaluate the effect of mindfulness intervention on improving mental health among undergraduate nursing students during the coronavirus disease 2019 (COVID-19) pandemic in China. Methods: An online mindfulness intervention course named Mindfulness Living With Challenge (MLWC) was developed by the research team, and a randomized controlled trial using MLWC among Chinese undergraduate nursing students was carried out. A total of 120 undergraduate nursing students were randomized into control (60 students) and intervention groups (60 students) via a WeChat mini program. Self-administered questionnaire surveys were conducted at pre- and post-intervention, measuring depression, anxiety, stress, mindfulness, and perceived social support. After intervention, the acceptance of the online mindfulness course among participants was assessed by employing the theory of technology acceptance model (TAM). Results: Among the enrolled 120 participants, 86.67% (52/60) and 93.33% (56/60) of the intervention and control groups remained completed the trial and the questionnaire surveys. Compared with the control group, the reduction of anxiety and stress symptoms, as well as the improvement of mindfulness level and perceived social support in the MLWC intervention group were statistically significant (P < 0.05), while the change in depression was not statistically significant. The scores of the four dimensions in TAM ranged from (5.88 ± 0.94) to (5.91 ± 0.97). Conclusion: Online mindfulness intervention implemented in this study is effective in improving mental health among undergraduate nursing students, and they were interested in this intervention. Clinical trial registration: [www.ClinicalTrials.gov], identifier [ChiCTR2 200058103].

Stress and Coping in Nurses Taking Care of People Living with HIV in Hunan, China: A Descriptive Qualitative Study.

BACKGROUND/PURPOSE: Nurses engaged in the care of people living with HIV (PLWH) are commonly exposed to workplace stress. This study aimed to explore the stress experiences and coping strategies among nurses taking care of PLWH in China. METHODS: Nurses were recruited from the AIDS department of a public, general, third-grade class-A hospital, which has the largest HIV care department in the Hunan Province of China. Thirty-three nurses working in the AIDS Department were recruited in this qualitative study. Eight nurses participated in a focus group and 25 nurses underwent in-depth individual interviews aimed at characterizing the nurse's feelings and struggles with stress during caregiving for PLWH. The interviews were audio-recorded, transcribed verbatim, anonymized, and imported into NVivo 8.0 software. The data were coded and subjected to thematic analysis. RESULTS: Concerns about occupational exposure, heavy workload, mental health problems and risk behaviors of patients, and discrimination towards nurses caring for PLWH were the four main sources of stress. The negative impact of stress included problems with emotion regulation, somatic health and sleep, and work performance. Some participants also reported a positive impact of work stress on their mental health. Using personality strengths, problem-solving, help-seeking, concealing and avoiding/suppression were common coping strategies employed by nurses caring for PLWH. CONCLUSION: Our findings help characterize the stress experienced by nurses caring for PLWH in the Chinese cultural context, and may inform specific interventions to help manage stress and promote mental health of nurses.

Childhood trauma and current depression among Chinese university students: a moderated mediation model of cognitive emotion regulation strategies and neuroticism.

BACKGROUND: Childhood trauma (CT) is considered as a highly risk factor for depression. Although the pathway of CT to depression, especially the mediating or moderating effects of cognitive emotion regulation strategies (CERS) or neuroticism, have investigated by several studies, the results were inconsistent and there is a paucity of full models among these interactive factors. This study aims to examine the relationships among CT, adaptive / maladaptive CERS, neuroticism, and current depression symptoms in university students. METHODS: We recruited 3009 freshman of 2019, aged averagely 18.00 (SD = 0.772) years, from universities in Hunan province in 2019. A moderated mediation model was built to examine the relationships among CT, CERS, neuroticism, and current depression using the SPSS PROCESS 3.5 macro. We conducted bootstrapping of regression estimates with 5000 samples and 95% confidence interval. RESULTS: Results revealed that the significant mediating effects of adaptive CERS (ß = 0.012; 95% CI: 0.006 to 0.018) and maladaptive CERS (ß = 0.028; 95% CI: 0.016 to 0.040) between CT and depression were observed, accounting for 5.69% and 13.52% of the total effect respectively. Then, moderated mediation analyses results showed that neuroticism simultaneously moderated the direct effect of CT on current depression (ß = 0.035; 95% CI: 0.001 to 0.009), and the indirect effects of CT on current depression through adaptive CERS (adaptive CERS - current depression: ß = - 0.034; 95% CI: - 0.007 to - 0.001) and maladaptive CERS (maladaptive CERS - current depression: ß = 0.157; 95% CI: 0.017 to 0.025). However, the moderating effects of neuroticism in the indirect paths from CT to adaptive CERS (ß = 0.037; 95% CI: 0.000 to 0.014) and maladaptive CERS (ß = - 0.001; 95% CI: - 0.006 to 0.005) were not significant. CONCLUSIONS: This study provides powerful evidences through a large university students sample for the mediating role of adaptive / maladaptive CERS and the moderating role of neuroticism between CT and current depression. This manifests that cognitive emotion regulation may be a vital factor for people who suffered from CT and current depression. Furthermore, the influence of neuroticism in this process cannot be ignored.

'Mindfulness Living with Insomnia': an mHealth intervention for individuals with insomnia in China: a study protocol of a randomised controlled trial.

INTRODUCTION: Insomnia has a remarkably negative effect on the work, quality of life and psychosomatic health of individuals, and imposes a substantial economic burden on society. Mindfulness-based interventions (MBIs) have proven beneficial in the treatment of insomnia. However, the effect of mobile or online-based (mHealth) MBIs requires further verification. This study will evaluate the effectiveness of an mHealth MBI, 'Mindful Living with Insomnia' (MLWI), relative to that of mHealth cognitive behavioural therapy for insomnia (CBT-I). METHODS AND ANALYSIS: The study is an mHealth, randomised controlled trial. Two hundred and fifty participants will be allocated randomly and equally to either the MLWI or CBT-I group. The intervention will involve 12 sessions over a 6-week course, with 2, 30 min sessions per week. The primary outcomes are sleep quality, severity of insomnia symptoms and sleep activity, according to the Pittsburgh Sleep Quality Index, Insomnia Severity Index and sleep tracker Mi Smart Band, respectively. The secondary outcomes are perceived stress, anxiety, depression and mindfulness. Outcomes will be evaluated at the baseline, end of the intervention period and at the 3-month follow-up. Data analyses will include covariance, regression analysis, χ2, t-test and Pearson's correlations. Participants will be recruited from January to June 2022, or until the recruitment process is complete. The follow-up will be completed in December 2022. All trial results should be available by the end of December 2022. ETHICS AND DISSEMINATION: Full approval for this study has been obtained from the Ethics Committee at The Third Xiangya Hospital, Central South University, Changsha, China (21010). Study results will be disseminated via social media and peer-reviewed publications. TRIAL REGISTRATION NUMBER: NCT04806009.

High-dose gatifloxacin-based shorter treatment regimens for MDR/RR-TB.

SETTING: The shorter treatment regimen (STR) for multidrug- or rifampicin-resistant tuberculosis (MDR/RR-TB) has achieved successful outcomes in many countries. However, there are few studies on high-dose gatifloxacin-based STR with adverse drug reactions (ADRs) and management. DESIGN: A prospective observational study was conducted with MDR/RR-TB patients who were treated with a standardized 9 or 12 - month regimen: including gatifloxacin (Gfx), clofazimine (Cfz), ethambutol (EMB), and pyrazinamide (PZA), and supplemented by amikacin (Am), isoniazid (INH), and prothionamide (Pto) during an intensive phase of 4 or 6 - month. Monitored ADRs monthly until treatment completion and then followed up every three months for one year. RESULTS: Among the 42 eligible patients, 35 (83.3%) completed treatment successfully, 1 (2.4%) lost to follow-up (LTFU), and 6 (14.3%) failed due to ADRs, with no death. The most important ADR was drug-induced liver damage, which occurred in 24 out of 42 (57.1%) patients and resulted in 4 (9.5%) failed treatments and 4 (9.5%) adjusted treatments. QT interval prolongation occurred in 17 out of 42 (40.5%) patients, 9 (21.4%) of them with the corrected QT interval according to Fridericia (QTcF) > 500 ms resulting in 7 (16.7%) adjusted treatments. CONCLUSIONS: This study confirmed the effectiveness of the high-dose gatifloxacin-based STR but severe ADRs, especially hepatotoxicity and QT interval prolongation should never be ignored.

Validation of the Committed Action Questionnaire-8 and Its Mediating Role Between Experiential Avoidance and Life Satisfaction Among Chinese University Students.

Background: Committed action is one of the core processes of psychological flexibility derived from acceptance and commitment therapy. It has not been widely investigated in mainland China as appropriate measures are lacking. The current study aimed to validate a Chinese (Mandarin) version of the Committed Action Questionnaire (CAQ-8) in a non-clinical college sample and to explore whether committed action would have a mediating effect in the association between experiential avoidance (EA) and life satisfaction. Methods: We translated the CAQ-8 into Chinese (Mandarin). A total of 913 Chinese undergraduates completed a set of questionnaires measuring committed action, EA, mindful awareness, anxiety, depression, stress, and life satisfaction. For test-retest reliability, 167 respondents completed the CAQ-8 again 4 weeks later. Results: The entire scale of CAQ-8 (Mandarin) and two subscales showed adequate internal consistency and acceptable test-retest reliability. Confirmatory factor analyses confirmed the two-factor structure and the convergent and criterion validity were acceptable. Committed action was correlated with less EA, more mindful awareness, less depressive symptoms, less anxiety, less stress, and more life satisfaction. In bootstrap mediation analyses, committed action partially mediated the association between EA and life satisfaction. Conclusion: The results suggest that the CAQ-8 (Mandarin) is a brief, psychometrically sound instrument to investigate committed action in Chinese populations, and the relationship between EA and life satisfaction was partially explained by committed action. This study provides new information about the usefulness of CAQ-8 and supports the assumption that committed action may be considered a promising factors for improving life satisfaction who have involved in EA among an educated non-clinical population.

Mindfulness-based online intervention on mental health and quality of life among COVID-19 patients in China: an intervention design.

BACKGROUND: COVID-19 can lead to increased psychological symptoms such as post-traumatic stress disorder (PTSD), depression, and anxiety among patients with COVID-19. Based on the previous mindfulness-based interventions proved to be effective, this protocol reports a design of a randomized controlled trial aiming to explore the efficacy and possible mechanism of a mindful living with challenge (MLWC) intervention developed for COVID-19 survivors in alleviating their psychological problems caused by both the disease and the pandemic. METHODS: In April 2021, more than 1600 eligible participants from Hubei Province of China will be assigned 1:1 to an online MLWC intervention group or a waitlist control group. All participants will be asked to complete online questionnaires at baseline, post-program, and 3-month follow-up. The differences of mental health status (e.g. PTSD) and physical symptoms including fatigue and sleeplessness between the COVID-19 survivors who receiving the online MLWC intervention and the control group will be assessed. In addition, the possible mediators and moderators of the link between the MLWC intervention and target outcomes will be evaluated by related verified scales, such as the Five Facets Mindfulness Questionnaire. Data will be analyzed based on an intention-to-treat approach, and SPSS software will be used to perform statistical analysis. DISCUSSION: The efficacy and potential mechanism of MLWC intervention in improving the quality of life and psychological status of COVID-19 survivors in China are expected to be reported. Findings from this study will shed light on a novel and feasible model in improving the psychological well-being of people during such public health emergencies. Trial registration Chinese Clinical Trial Registry (ChiCTR), ChiCTR2000037524; Registered on August 29, 2020, http://www.chictr.org.cn/showproj.aspx?proj=60034 .

Mindfulness-Based Intervention For Nurses In AIDS Care In China: A Pilot Study.

BACKGROUND/PURPOSE: Workplace stress among nurses providing care for people living with human immunodeficiency virus is a serious problem in China that may increase rates of job burnout and affect quality of care. Mindfulness-based intervention has been shown to be effective in relieving stress and burnout in nurses. Therefore, we designed a mixed-method pilot study to evaluate a mindfulness-based intervention for nurses providing care for people living with human immunodeficiency virus. METHODS: Twenty nurses caring for people living with human immunodeficiency virus in the First Hospital of Changsha, China participated in a mindfulness-based intervention for 2 hr sessions weekly for 6 weeks. The Perceived Stress Scale, Maslach Burnout Inventory, Five Facets Mindfulness Questionnaire, State-Trait Anxiety Inventory, and the Beck Depression Inventory were used to collect data before and after the mindfulness-based intervention. Participants were invited to attend an in-depth interview 1 week after the end of the mindfulness-based intervention to give feedback. RESULTS: The quantitative analyses revealed a significant change in Five Facets Mindfulness Questionnaire scores. There were no significant differences between pre- and post-intervention measures of any other variables. Qualitative results showed nurses experienced a decrease in work and daily life pressures; improvements in communications with patients, colleagues and families, with better regulation of negative emotions, and acceptance of other people and attention. CONCLUSION: This study supports the acceptability and potential benefits of the mindfulness-based intervention in helping nurses caring for people living with human immunodeficiency virus to manage stress and emotions, and improve their acceptance of others and attention. A larger study with a randomized controlled trial design is warranted to confirm the effectiveness of this mindfulness-based intervention.

Efficacy of mindfulness-based intervention ('mindfulness-based joyful sleep') in young and middle-aged individuals with insomnia using a biomarker of inflammatory responses: a prospective protocol of a randomised controlled trial in China.

INTRODUCTION: Insomnia is a prevalent and significant public health concern. Insomnia can lead to increased inflammatory markers associated with chronic diseases such as cardiovascular disease, diabetes and cancer. Studies suggest that mindfulness-based interventions (MBIs) are more easily delivered within the community than cognitive behavioural therapy for insomnia (CBT-I) which was recommended as the preferred non-pharmacological treatment by the American Academy of Sleep Medicine, are effective in insomnia treatment and can reduce inflammatory markers level in older individuals with insomnia. This study aims to compare the effectiveness of an MBI to CBT-I in young and middle-aged individuals with insomnia disorder and explore its effect on nuclear factor kappa B (NF-κB), a transcription factor that controls the expression of genes involved in inflammation. METHODS AND ANALYSIS: This report describes a protocol for a randomised controlled trial. Seventy eligible participants will be assigned to mindfulness-based joyful sleep or CBT-I for 2-hour sessions weekly for 8 weeks. The primary outcome is sleep quality assessed by the Pittsburgh Sleep Quality Index, severity of insomnia symptoms assessed by the Insomnia Severity Index and sleep parameters recorded using sleep diary and polysomnography. Secondary outcomes include perceived stress, anxiety and depression. The exploratory outcome is serum level of NF-κB. Outcomes will be evaluated at baseline, the end of the ntervention period and at a 3 month follow-up. Data will be analysed using general linear models, specifically analysis of covariance and analysis of variance will be used. ETHICS AND DISSEMINATION: Full ethical approval for this study has been obtained from the Ethics Committee of the Third Xiangya Hospital, Central South University, Changsha, China (2018-S236). If Mindfulness-Based Joyful Sleep is proven effective, its dissemination will help bridge the gap between the unmet need and the demand for insomnia interventions in China. TRIAL REGISTRATION NUMBER: NCT03268629; Pre-results.

Can Verona Coding Definitions of Emotional Sequences (VR-CoDES) be applied to standardized Chinese medical consultations? - A reliability and validity investigation.

OBJECTIVE: To investigate the reliability and validity of the Chinese version of VR-CoDES. METHODS: The VR-CoDES was translated into Chinese, and a focus group was held to discuss its cultural adaptation. Video consultations between 75 fourth-year medical students and 2 standardized patients (SPs) were coded by two raters with the Chinese VR-CoDES. Inter-rater reliability was tested by using ICC. To obtain validity, the SPs reviewed the video consultations to confirm the cues and concerns. RESULTS: ICC was 0.79. Specificity and sensitivity were 0.99 and 0.96 respectively. The SPs expressed considerably more cues (mean = 7.00) than concerns (mean = 0.32). Half of the responses of medical students were explicit reducing space. Focus group participants raised some cultural considerations, and some interactions were difficult to code due to cultural differences. CONCLUSION: The Chinese VR-CoDES obtained good reliability and validity. Due to differences in the expression of emotions and other differences such as different medical systems between China and Western countries, the Chinese VR-CoDES needs further cultural adaptation. PRACTICE IMPLICATION: More consultations in real clinical settings need to be gathered to further support the Chinese VR-CoDES both on validation and cultural adaptation.

[Alexithymia and negative emotions in cancer patients: Mediating effects of intrusive thoughts].

OBJECTIVE: To explore associations of negative emotions with alexithymia and intrusive thoughts in cancer patients.
 Methods: A total of 115 cancer patients were assessed by Impact of Event Scale-Revised, the 20-item Toronto Alexithymia Scale, the Center for Epidemiological Studies Depression Scale, and the state anxiety subscales of State-Trait Anxiety Inventory.
 Results: Negative emotions were positively correlated with alexithymia and the intrusive thoughts (r 0.251 to 0.600, P<0.01). Intrusive thoughts were significantly associated with the total score of alexithymia, difficulty in identifying feelings, and difficulty in describing feelings (r 0.261 to 0.430, P<0.01). The relation between alexithymia and negative emotions was partially mediated by intrusive thoughts, accounting for 40.71% of the alexithymia in total negative emotions.
 Conclusion: Intrusive thoughts play a role, at least partially in mediation of alexithymia and negative emotions.

[Research progress of depression and the application of esketamine].

OBJECTIVE: The pathogenesis and etiology of still remain unknown. Current evidence suggests that the occurrence of depression may be related to a reduced secretion of neurotransmitters, neuronal apoptosis, inflammation, intestinal flora and other factors. Although the commonly used antidepressants such as SSRIs, SNRIs, NaSSA, and SARIs produce some therapeutic effects, they fail to relieve the full spectrum of the symptoms of depression. In recent years, esketamine was found to produce a potent and a long-lasting antidepressant effect by acting on the NMDA receptors. Herein the authors review the progress in the study of the pathogenesis and drug therapies of depression, the efficacy of esketamine treatment and the underlying mechanism, and the prospect of esketamine treatment. Currently the mechanism of the antidepressant effect of esketamine remains indeterminate and its clinical application is limited, but its effect in rapidly alleviating the symptoms of depression suggests its bright prospect for clinical applications.

COMT gene haplotypes are closely associated with postoperative fentanyl dose in patients.

BACKGROUND: Fentanyl's analgesic efficacy varies widely among individuals. The single-nucleotide polymorphisms (SNPs) of catechol-O-methyltransferase (COMT) modulate sensitivity to pain. It remains unclear, however, whether COMT genetic variability affects postoperative fentanyl analgesia in patients undergoing radical gastrectomy. METHODS: One hundred fifteen patients, ASA physical status I-III, who were scheduled for radical gastrectomy under general anesthesia, were enrolled in this study. Patient-controlled IV analgesia with fentanyl was administered during the first 48 hours after surgery. Visual analog scale score for patients' pain was maintained at ≤30 mm. The amount of fentanyl consumed and side effects were recorded for the first 24 and 48 hours postoperatively. The SNPs of COMT (rs6269, rs4633, rs4818, and rs4680) of all patients were screened by DNA sequence analysis of polymerase chain reaction-amplified DNA or polymerase chain reaction-restriction fragment length polymorphism. RESULTS: There were no significant differences in the doses of fentanyl used among patients possessing different SNPs of COMT rs6269, rs4633, rs4818, and rs4680 at 24 (all P > 0.207) and 48 (all P > 0.148) hours after surgery. COMT gene haplotypes combined by COMT rs6269, rs4633, rs4818, and rs4680, however, significantly affected fentanyl consumption at 24 (P = 0.029) and 48 (P = 0.032) hours after surgery. Among the haplotypes of COMT gene, patients with haplotype ACCG consumed more fentanyl than GCGG and ATCA haplotypes during the first 24 and 48 hours (all P < 0.042) after surgery. No significant differences were found in the incidence of nausea, vomiting, and dizziness among the 4 SNPs of COMT gene (all P > 0.079) and their haplotypes (all P > 0.482). CONCLUSIONS: COMT gene haplotype constructed by rs6269, rs4633, rs4818, and rs4680 contributes to the individual variation of postoperative analgesia with fentanyl. Patients carrying the COMT gene haplotype ACCG consumed the most drug during the first 24 and 48 hours postoperatively.

Brain response during visual emotional processing: an fMRI study of alexithymia.

Alexithymia is found in up to 10% of the general population and is associated with lower quality of life. Alexithymia is a major risk factor for a range of medical and psychiatric problems. Although a deficit involving the anterior cingulate cortex (ACC) deficit is thought to offer the most promising neurobiological model of alexithymia, current studies have yielded inconsistent findings. In this study, neural activity was investigated in well-controlled alexithymic individuals subjected to emotional stimuli. Fifteen individuals with high Toronto Alexithymia Scale (TAS-20) scores (high-alexithymic group) and 15 individuals with low TAS-20 scores (low-alexithymic group) were screened from 432 female college students. Depressive and anxious behaviors were scored using self-rating depression scale (SDS) and self-rating anxiety scale (SAS) questionnaires, respectively. Emotional stimuli consisted of pictures with positive, negative, or neutral pleasantness and high or low arousal of emotional intensity. Regional cerebral activation was measured by functional magnetic resonance imaging (fMRI). The anterior cingulate, mediofrontal cortices, insula and temporal lobe were significantly activated by intense emotional stimuli (negative or positive pictures) in high-alexithymic individuals compared to low-alexithymic individuals. Conversely, high-alexithymic and low-alexithymic individuals showed similar brain activity when subjected to neutral stimuli. Alexithymia is associated with activation in anterior cingulate and mediofrontal cortices during emotional stimuli processing. Therefore, our findings support the hypothesis that altered ACC function may be implicated in alexithymia.

The cultural shaping of alexithymia: values and externally oriented thinking in a Chinese clinical sample.

OBJECTIVE: Alexithymia is a multi-faceted personality construct characterized by difficulties in identifying and describing emotional states. Originally based on observations of American psychosomatic patients, the construct is now studied in a variety of cultural contexts. However, few studies have critically examined alexithymia from a cultural perspective. Dere et al. [1] recently found support for the hypothesis that one alexithymia component - externally oriented thinking (EOT) - is linked to cultural values, among Euro-Canadian and Chinese-Canadian students. The current study examines this association in a Chinese clinical sample. METHODS: Outpatients presenting at three hospital-based psychology clinics in Hunan province, China (N=268) completed a structured clinical interview and self-report measures of alexithymia and cultural values. All participants endorsed clinically significant levels of depressed mood, anhedonia, and/or fatigue. RESULTS: As expected, EOT was negatively predicted by Modernization and Euro-American values. Two other alexithymia components, difficulty identifying feelings and difficulty describing feelings, were unrelated to cultural values. CONCLUSION: These findings suggest that cultural variations in the importance placed on emotional experience must be taken into account in cross-cultural alexithymia research. Such studies should also consider separately the specific components of alexithymia; failure to do so can lead to overestimation of alexithymia in groups where scores are driven by culturally-promoted EOT.

Pain-related mediators underlie incision-induced mechanical nociception in the dorsal root ganglia.

Approximately 50-70% of patients experience incision-induced mechanical nociception after surgery. However, the mechanism underlying incision-induced mechanical nociception is still unclear. Interleukin-10 and brain-derived neurotrophic factor are important pain mediators, but whether interleukin-10 and brain-derived neurotrophic factor are involved in incision-induced mechanical nociception remains uncertain. In this study, forty rats were divided randomly into the incision surgery (n = 32) and sham surgery (n = 8) groups. Plantar incision on the central part of left hind paw was performed under anesthesia in rats from the surgery group. Rats in the sham surgery group received anesthesia, but not an incision. Von Frey test results showed that, compared with the sham surgery group, incision surgery decreased the withdrawal threshold of rats at 0.5, 3, 6 and 24 hours after incision. Immunofluorescence staining in the dorsal root ganglia of the spinal cord (L3-5) showed that interleukin-10 and brain-derived neurotrophic factor were expressed mainly on small- and medium-sized neurons (diameter < 20 µm and 20-40 µm) and satellite cells in the dorsal root ganglia of the spinal cord (L3-5) in the sham surgery group. By contrast, in the surgery group, high expression of interleukin-10 and brain-derived neurotrophic factor appeared in large-sized neurons (diameter > 40 µm) at 6 and 24 hours after incision surgery, which corresponded to the decreased mechanical withdrawal threshold of rats in the surgery group. These experimental findings suggest that expression pattern shift of interleukin-10 and brain-derived neurotrophic factor induced by incision surgery in dorsal root ganglia of rats was closely involved in lowering the threshold to mechanical stimulus in the hind paw following incision surgery. Pain-related mediators induced by incision surgery in dorsal root ganglia of rats possibly underlie mechanical nociception in ipsilateral hind paws.