Microglia may compensate for dopaminergic neuron loss in experimental Parkinsonism through selective elimination of glutamatergic synapses from the subthalamic nucleus.

Parkinson's disease (PD) symptoms do not become apparent until most dopaminergic neurons in the substantia nigra pars compacta (SNc) degenerate, suggesting that compensatory mechanisms play a role. Here, we investigated the compensatory involvement of activated microglia in the SN pars reticulata (SNr) and the globus pallidus (GP) in a 6-hydroxydopamine-induced rat hemiparkinsonism model. Activated microglia accumulated more markedly in the SNr than in the SNc in the model. The cells had enlarged somata and expressed phagocytic markers CD68 and NG2 proteoglycan in a limited region of the SNr, where synapsin I- and postsynaptic density 95-immunoreactivities were reduced. The activated microglia engulfed pre- and post-synaptic elements, including NMDA receptors into their phagosomes. Cells in the SNr and GP engulfed red fluorescent DiI that was injected into the subthalamic nucleus (STN) as an anterograde tracer. Rat primary microglia increased their phagocytic activities in response to glutamate, with increased expression of mRNA encoding phagocytosis-related factors. The synthetic glucocorticoid dexamethasone overcame the stimulating effect of glutamate. Subcutaneous single administration of dexamethasone to the PD model rats suppressed microglial activation in the SNr, resulting in aggravated motor dysfunctions, while expression of mRNA encoding glutamatergic, but not GABAergic, synaptic elements increased. These findings suggest that microglia in the SNr and GP become activated and selectively eliminate glutamatergic synapses from the STN in response to increased glutamatergic activity. Thus, microglia may be involved in a negative feedback loop in the indirect pathway of the basal ganglia to compensate for the loss of dopaminergic neurons in PD brains.

Miliary tuberculosis diagnosed by diffuse hepatic uptake on PET/CT and transjugular liver biopsy.

The patient was an 81-year-old man. In his 20s, he had been treated with pharmacotherapy for pulmonary tuberculosis for 1 year. He presented to the Department of Respiratory Medicine with a chief complaint of dyspnea. The possibility of respiratory disease appeared to be low, but hepatic impairment was detected. The patient was thus referred to our department. Though the cause of hepatic impairment was unknown, the soluble interleukin-2 receptor level was elevated, suggesting malignant lymphoma. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) revealed diffuse, homogenous, intense FDG uptake in the entire liver, and transjugular liver biopsy confirmed the diagnosis. Histopathological examination revealed an epithelioid granuloma, and auramine staining was positive for bacilli suggestive of tuberculosis. CT revealed diffuse micronodular shadows in the lung, yielding a diagnosis of miliary tuberculosis. Therefore, the patient was prescribed antituberculosis medication by the Department of Respiratory Medicine. His subsequent clinical course was good. The miliary (hepatic) tuberculosis was typical based on the diffuse, homogenous, intense FDG uptake throughout the liver observed on PET-CT.

Current treatment options for esophageal diseases.

Exciting new developments-pharmacologic, endoscopic, and surgical-have arisen for the treatment of many esophageal diseases. Refractory gastroesophageal reflux disease presents a therapeutic challenge, and several new options have been proposed to overcome an insufficient effectiveness of proton pump inhibitors. In patients with distal esophageal spasm, drugs and endoscopic treatments are the current mainstays of the therapeutic approach. Treatment with proton pump inhibitors (or antireflux surgery) should be considered in patients with Barrett's esophagus, since a recent meta-analysis demonstrated a 71% reduction in risk of neoplastic progression. Endoscopic resection combined with radiofrequency ablation is the standard of care in patients with early esophageal adenocarcinoma. Mucosal squamous cancer may also be treated endoscopically, preferably with endoscopic submucosal dissection. Patients with upper esophageal cancer often refrain from surgery. Robot-assisted, thoracolaparoscopic, minimally invasive esophagectomy may be an appropriate option for these patients, as the robot facilitates a good overview of the upper mediastinum. Induction chemoradiotherapy is currently considered as standard treatment for patients with advanced squamous cell carcinoma, while the role of neoadjuvant therapy for adenocarcinoma remains controversial. A system for defining and recording perioperative complications associated with esophagectomy has been recently developed and may help to find predictors of mortality and morbidity.