Although it has been accepted that depression and pain are common comorbidities, their interaction is not fully understood. The present study was aimed to investigate the effects of depression on both evoked pain behavior (thermal induced nociception and hyperalgesia) and spontaneous pain behavior (formalin pain) in rats. An unpredictable chronic mild stress (UCMS) paradigm was employed to develop a classical depression. The emotional behaviors were assessed by sucrose preference test, open field test, and elevated plus-maze test. The results showed that the depressed rats always exhibited stronger tolerance to noxious thermal stimulation under both normal and complete Freund's adjuvant (CFA)-induced chronic pain conditions, when compared to non-depressed animals. Interestingly, the spontaneous nociceptive behaviors induced by formalin injection were significantly enhanced in rats exposed to UCMS in comparison to those without UCMS. Systemic administration of antidepressant fluoxetine significantly restored the nociceptive behaviors to normal level in depressed animals. An additional finding was that the inflammatory rats tended to display depressivelike behaviors without being exposed to UCMS. These results demonstrated that depression can have different effects on stimulus-evoked pain and spontaneous pain, with alleviation in the former while aggravation in the latter. Perspective:The present study provides evidence that depression can have divergent effects on stimulus-evoked and spontaneous pain by confirming that rats exposed to chronic mild stress tend to exhibit decreased pain sensitivity to experimental stimuli but increased intensity of ongoing pain. This may contribute to further understanding of the perplexing relationship between clinical depression and chronic pain.

Both PCT and CRP are useful markers and should be used to evaluate SBIs with fever of unknown origin.

Clinical observations suggest that depressed patients were less sensitive to experimental pain than healthy subjects. However, few animal studies are reported concerning the association of depression and pain. The purpose of this study was to investigate the effects of unpredictable chronic mild stress (UCMS) induced depression on the perceived intensity of painful stimulation in rats. We measured the thermal and mechanical paw withdrawal thresholds (PWT) of normal and spinal nerve ligated (SNL) rats using hot plate test and von Frey test, respectively. The results showed that rats exposed to UCMS exhibited significantly higher thermal and mechanical pain thresholds in comparison to the non-depressed controls. In particular, the PWT of the SNL group was restored to nearly normal level after three weeks of UCMS, and even comparable to that of the control group. These results strongly suggest that the depressed subjects have decreased sensitivity to externally applied noxious stimulation, which is consistent with our previous findings. Research Highlight ▶ Unpredictable chronic mild stress (UCMS) induces depressive behaviors in rats ▶ UCMS elevates contact heat paw withdrawal threshold in normal rats ▶ UCMS elevates mechanical paw withdrawal threshold in normal rats ▶ UCMS elevates mechanical paw withdrawal threshold in SNL rats

Rationale:Longitudinally extensive transverse myelitis (LETM) is characterized by contiguous inflammatory lesions of spinal cord extending to ≥3 vertebral segments. The etiology of LETM is complicated, including various infection, autoimmune disease, and so on. Neuromyelitis optic spectrum disorder (NMOSD) is the most common cause of LETM. Several case reports have suggested the associations between NMOSD and pulmonary tuberculosis (PTB).Patient concerns:Patient 1, a 20-year-old woman who had a past history of PTB, presented with weakness, numbness, and pain in the limbs. The serum anti-aquaporin-4 antibody (AQP4-Ab) was strongly positive, and the magnetic resonance imaging (MRI) scan of cervical and thoracic spinal cord after admission to the hospital revealed hyperintensity lesions extending from C3 to T8 on T2-weighted (T2W) image, T1-weighted (T1W) image, and fluid-attenuated inversion recovery (FLAIR) image. Patient 2, a 21-year-old woman who had a past medical history of PTB without receiving any treatment, presented for numbness in bilateral lower limbs and in the chest. The anti-AQP4-Ab was negative both in the serum and in the cerebral spinal fluid (CSF) of the patient. The MRI scan during hospitalization of cervical and thoracic spinal cord revealed diffuse hyperintense signal extending C3 to T11 on T2W and FLAIR images and hypointense signal on T1W image.Diagnosis:The first patient was diagnosed with anti-AQP4-Ab positive NMOSD, while the second case was an anti-AQP4-Ab negative LETM patient.Interventions:Both of the patients received a combination of corticosteroid and anti-tuberculosis (isonicotinyl hydrazide 0.3 g/d, rifampin 0.45 g/d, pyrazinamide 1 g/d, and ethambutol 1 g/d) treatment.Outcomes:The patients were followed up for up to 1 year. The Expanded Disability Status Scale (EDSS) of both patients were decreased and the lesion size in the spinal cord was significantly reduced at the time point of the follow-up.Lessons:Combination of anti-tuberculosis and corticosteroid treatment may have better prognosis for patient of LETM with PTB.

Objective: To summarize the characteristics of muscle-specific receptor tyrosine kinase antibody-positive myasthenia gravis (MuSK-MG) in Northeast China. Methods: We retrospectively collected 183 confirmed MG patients and divided them into three groups based on the type of serum antibodies: MuSK-MG (14 cases), acetylcholine receptor (AChR)-MG (130 cases), and double-seronegative (DSN)-MG (39 cases). The clinical, diagnostic, therapeutic, and prognosis data were analyzed. Results: MuSK antibody was detected in 26.7% of seronegative MG. The mean age of onset in MuSK-MG was 53.2 ± 13.6 years. Fifty percent of MuSK-MG patients with an onset symptom of pure ocular muscle weakness. The time from onset to other muscle groups' involvement and the time from onset to myasthenic crisis had no significant difference among the three groups ( P > 0.05). The proportion of Osserman classification I in MuSK-MG group was lower than that in DSN-MG group. The proportion of Osserman classification IV in MuSK-MG group was higher than that in the other two groups. The incidences of other coexisting autoimmune diseases in MuSK-MG group were higher. Prognosis after the treatment of steroid combined with tacrolimus for MuSK-MG was similar to AChR-MG treated with steroid combined with an immunosuppressant agent ( P > 0.05). Conclusion: Patients with MuSK-MG in Northeast China have a modestly later onset age and a proportion of patients may have a mild form of the disease with delayed disease progression. We confirmed the existence of a rare ocular MuSK-MG phenotype, a high proportion of coexisting with other autoimmune diseases, and a good response to steroids combined with tacrolimus for our MuSK-MG series.