A combined cumulative threshold spectra and digital reconstruction analysis reveal structural alterations of microglia within the prefrontal cortex following low-dose LPS administration.

Sickness behaviors have become the focus of great interest in recent years as they represent a clear case of how peripheral disturbances in immune signaling can disrupt quite complex behaviors. In the current study, we were interested in examining whether we could identify any significant morphological disturbances in microglia associated with these sickness-like behaviors in adult male Sprague-Dawley rats. We chose lipopolysaccharide (LPS 100 µg/kg/i.p.), to induce sickness-like behaviors as it is the most well-validated approach to do so in rodents and humans. We were particularly interested in examining changes in microglia within the prefrontal cortex (PFC) as several recent neuroimaging studies have highlighted significant functional changes in this region following peripheral LPS administration. Paraformaldehyde-fixed tissue was collected from animals 24h post LPS administration and labeled immunohistochemically with an antibody directed to bind to Iba-1, a protein known to be involved in the structural remodeling of microglia. To analyze changes, we have made use of two recently described image analysis procedures. The first is known as cumulative threshold spectra (CTS) analysis. The second involves the unsupervised digital reconstruction of microglia. We undertook these complementary analysis of microglial cells in the both the pre- and infralimbic divisions of the PFC. Our results indicated that microglial soma size was significantly enlarged, while cell processes had contracted slightly following LPS administration. To our knowledge this study is to first to definitely demonstrate substantial microglial disturbances within the PFC following LPS delivered at a dose that was sufficient to induce significant sickness-like behavior.

Spontaneous Regression of a Carcinoid Tumor following Pregnancy.

We present a case of spontaneous regression of a neuroendocrine tumor following pregnancy in the absence of chemotherapy, radiotherapy, or alternative medicine (including herbal medicine). The diagnosis of a nonsecretory carcinoid tumor was confirmed using CT imaging, octreotide scan, and histology. Furthermore, serial imaging has demonstrated spontaneous regression of the carcinoid suggesting that pregnancy did not worsen the course of the disease but instead may have contributed to tumour regression. We discuss mechanisms underlying tumour regression and the possible effect of pregnancy on these processes.

Myxoglobulosis, a rare variant of appendiceal mucocele, occurring secondary to an occlusive membrane.

A 77-year-old man presented with altered bowel habit and episodic right lower abdominal discomfort. A barium enema showed a large smooth filling defect in the caecum and at operation his appendix was seen to be hugely distended. Pathological examination showed myxoglobulosis, a rare variant of mucocele of the appendix. The appendiceal orifice was completely occluded by an imperforate membrane with no communication between the appendix and caecum. This is the first published report in the English language of appendiceal myxoglobulosis in association with such an occlusive membrane.

Chronic peripheral nerve pain treated with direct electrical nerve stimulation.

Chronic somatic peripheral nerve pain was treated prospectively in 24 nonrandomized patients by a program of direct electrical nerve stimulation. Patients qualified for the program if anesthetic (lidocaine) nerve block of the involved cutaneous zone of the peripheral nerve relieved symptoms and transcutaneous electrical nerve stimulation transiently improved and did not exacerbate somatic pain. Results were judged according to a pain score. Patients noted improved sleep and complete absence of the need for narcotic pain medication. On the basis of subjective and objective criteria, 18 patients had good or excellent results and 6 had implant failures. Of the six patients with failures, three failed the trial period and did not have implantation, and three had no significant pain relief and were judged as treatment failures. Three patients had late equipment failure after initial good results. Most patients had some relief of pain, which increased their quality of life and eliminated the need for narcotic analgesia. Direct electrical nerve stimulation should be considered for somatic peripheral nerve pain that has not been ameliorated with other methods. It will reduce, although not necessarily eliminate, pain and pain behavior in most patients.