Glial Cells Shape Pathology and Repair After Spinal Cord Injury

Glial cell types were classified less than 100 years ago by del Rio-Hortega. For instance, he correctly surmised that microglia in pathologic central nervous system (CNS) were “voracious monsters” that helped clean the tissue. Although these historical predictions were remarkably accurate, innovative technologies have revealed novel molecular, cellular, and dynamic physiologic aspects of CNS glia. In this review, we integrate recent findings regarding the roles of glia and glial interactions in healthy and injured spinal cord. The three major glial cell types are considered in healthy CNS and after spinal cord injury (SCI). Astrocytes, which in the healthy CNS regulate neurotransmitter and neurovascular dynamics, respond to SCI by becoming reactive and forming a glial scar that limits pathology and plasticity. Microglia, which in the healthy CNS scan for infection/damage, respond to SCI by promoting axon growth and remyelination—but also with hyperactivation and cytotoxic effects. Oligodendrocytes and their precursors, which in healthy tissue speed axon conduction and support axonal function, respond to SCI by differentiating and producing myelin, but are susceptible to death. Thus, post-SCI responses of each glial cell can simultaneously stimulate and stifle repair. Interestingly, potential therapies could also target interactions between these cells. Astrocyte–microglia cross-talk creates a feed-forward loop, so shifting the response of either cell could amplify repair. Astrocytes, microglia, and oligodendrocytes/precursors also influence post-SCI cell survival, differentiation, and remyelination, as well as axon sparing. Therefore, optimizing post-SCI responses of glial cells—and interactions between these CNS cells—could benefit neuroprotection, axon plasticity, and functional recovery.     

Striatal creatine and glutamate/glutamine in attention-deficit/hyperactivity disorder

OBJECTIVE: The glutamatergic prefrontal-striatal pathway has been implicated previously in the neurobiology of attention-deficit/hyperactivity disorder (ADHD). We used short echo proton magnetic resonance spectroscopy (1H-MRS) to examine glutamate in the prefrontal cortex, left striatum, and, as a control area, the occipital lobe. METHOD: Thirteen treatment-na?ve ADHD children and 10 healthy comparison subjects participated. All were males between the ages of 6 to 11 years of age. Twelve ADHD subjects were scanned after 8 weeks of treatment. RESULTS: Striatal glutamate, glutamate/glutamine (Glx) and creatine concentrations were greater in the ADHD subjects at baseline as compared to controls. Only striatal creatine, not glutamate or Glx, was reduced after stimulant treatment in the ADHD patients. No significant differences between groups were noted in the remainder of the striatal metabolites or any of the occipital lobe or prefrontal cortex metabolites. CONCLUSIONS: These findings provide initial evidence of a striatal creatine/glutamatergic dysregulation in ADHD.     

Practical and technical considerations in establishing an intraoperative radiation therapy program in the community practice

The Radiation Oncology Center in Sacramento, California, has developed a procedure for establishing an intraoperative radiation therapy facility in a community practice. The logistics pertaining to personnel, equipment, physical measurements, and quality assurance are presented. Particular emphasis is given to the most effective means of acquiring the large quantity of data needed to ensure a program of acceptable quality.     

The epidemiology of gastric cancer

The epidemiology of gastric cancer is remarkable for both its dramatic decline in incidence over the past century and its continuing presence as the second leading cause of cancer deaths worldwide despite this decline. Factors including increased consumption of fruits and vegetables, and decreased intake of salty foods have largely been credited for the decline. Epidemiologic studies continue to provide data on other gastric cancer risk factors, including associations with Helicobacter pylori infection, as well as dietary factors, tobacco, and alcohol intake. In response to the opposing trends of decreasing distal gastric cancer and increasing gastric cardia adenocarcinoma, studies are beginning to identify gastric cancer risk factors separately by tumor subsite. Future epidemiologic studies that include information on site of origin as well as molecular markers promise to yield more homogeneous classification of case groups, which will enhance identification of underlying disease processes.     

Psoriasin expression in mammary epithelial cells in vitro and in vivo.

We determined, by serial analysis of gene expression (SAGE) analysis of normal and DCIS (ductal carcinoma in situ) mammary epithelial cells, that psoriasin and several other genes implicated in psoriasis are aberrantly expressed in high-grade, comedo DCIS. Real-time PCR, mRNA in situ hybridization, and immunohistochemical analysis of breast carcinomas confirmed that psoriasin is frequently overexpressed in estrogen receptor-negative tumors. To gain insight into regulatory pathways that control psoriasin expression, we developed polyclonal and monoclonal antibodies and investigated mechanisms that may account for elevated levels of psoriasin in DCIS. Here, we report that loss of attachment to extracellular matrix, growth factor deprivation, and confluent conditions dramatically up-regulate psoriasin expression in MCF10A mammary epithelial cells. All of these conditions are characteristic of high-grade DCIS and psoriatic skin lesions; therefore, the same mechanisms may be responsible for increased expression of psoriasin in vitro and in vivo.     

External Cephalic Version at Term

Summary: The case notes of women with singleton term (37 weeks' gestation and beyond) breech presentation and delivery were retrospectively reviewed. Thirty-two of the 72 women in the study group had attempted external cephalic version at term, with a success rate of 53% (17 women). The Caesarean section rate was significantly lower in the group which had attempted ECV compared to the group which did not.