Neurosyphilis is a group of clinical syndromes caused by treponema pallidum invading the central nervous system and causing varying degrees of damage to the brain parenchyma, brain (spinal) membrane or spinal cord. Cerebral syphilitic gumma is the rarest form of neurosyphilis, and its clinical manifestations lack specificity, which is easily confused with other intracranial space occupying lesions on imaging. In this article, a patient with cognitive dysfunction, intracranial hypertension, and imaging findings similar to multicentric glioma was diagnosed as cerebral syphilitic gumma by serology, cerebrospinal fluid test and brain histopathology. The symptoms basically disappeared after treatment with standard penicillin. This report aims to raise awareness of cerebral syphilitic gumma in order to reduce missed diagnosis and misdiagnosis.

Neurosyphilis is a group of clinical syndromes caused by treponema pallidum invading the central nervous system and causing varying degrees of damage to the brain parenchyma, brain (spinal) membrane or spinal cord. Cerebral syphilitic gumma is the rarest form of neurosyphilis, and its clinical manifestations lack specificity, which is easily confused with other intracranial space occupying lesions on imaging. In this article, a patient with cognitive dysfunction, intracranial hypertension, and imaging findings similar to multicentric glioma was diagnosed as cerebral syphilitic gumma by serology, cerebrospinal fluid test and brain histopathology. The symptoms basically disappeared after treatment with standard penicillin. This report aims to raise awareness of cerebral syphilitic gumma in order to reduce missed diagnosis and misdiagnosis.

Objective To observe the effect of stress on the rapid component of delayed rectifier potassium current (IKr) in rat cardiomyocytes. Methods Forty male SD rats were randomly divided into four groups (10 each): control group (Ctrl), exhaustive group (ES), noise group (WN) and composite group (ES+WN). Stress animal models were prepared as follows: Rats in ES group were undergoing exhaustive swimming as the stress factor, in WN group undergoing white noise and in ES+WN group undergoing exhaustive swimming + white noise as the stress factor. Langendorff device was used to reversely perfuse collagenase for isolating the rat's ventricular myocytes. The effect of stress on IKr current and gating mechanism of single ventricular myocyte was recorded by whole-cell patch clamp technique. Results Compared with the Ctrl group, the tail current density of IKr (IKr,tail) of ventricular myocytes increased significantly in ES group and WN group (P<0.01). The IKr,tail current density of the ventricular myocytes in ES+WN group was significantly higher than that in ES group and WN group (P<0.01), and the effect was voltage dependent. Gating mechanism revealed that the half inactivation voltage of IKr,tail (V1/2,inact) can be shifted to the right in ES group, WN group and ES+WN group when compared with the Ctrl group, and the recovery time constant shortened after inactivation (P<0.01). However, the steady-state activation, fast inactivation constant and voltage dependence of IKr,tail were not statistically significant in ES group, WN group and ES+WN group when compared with the Ctrl group. Conclusion Stress increases the IKr current in rat cardiomyocytes, suggesting it be one of the electrophysiological bases of stress-induced arrhythmia.