Astrocyte phenotypes and their relationship to myelination

Astrocytes are one of the major glial cell types that maintain homeostasis in the undamaged CNS. After injury and disease, astrocytes become reactive and prevent regeneration; however, it has also been suggested that astrocytes can become activated and promote regeneration. Thus, it is hypothesised that astrocytes have an important role in modulating CNS repair. This review will focus on the variable phenotypic state of astrocytes that range from inactive/quiescent to reactive, and relate these to their ability to influence myelination. Using myelinating cultures plated on astrocytes we propose a possible mechanism for oligodendrocyte precursor cell interaction with the axon, leading to myelination. The phenotypic status of astrocytes is an intriguing and widely discussed issue, which is critical for understanding the mechanisms involved in CNS injury and its subsequent repair.     

Antipsychotic use and diagnosis of delirium in the intensive care unit

ABSTRACT: INTRODUCTION: Delirium is an independent risk factor for prolonged hospital length of stay (LOS) and increased mortality. Several antipsychotics have been studied for the treatment of intensive care unit (ICU) delirium that has led to a high variability in prescribing patterns for these medications. We hypothesize that in clinical practice the documentation of delirium is lower than the incidence of delirium reported in prospective clinical trials. The objective of this study was to document the incidence of delirium diagnosed in ICU patients and to describe the utilization of antipsychotics in the ICU. METHODS: This was a retrospective, observational, cohort study conducted at 71 United States academic medical centers that reported data to the University Health System Consortium Clinical Database/Resource Manager. It included all patients 18 years of age and older admitted to the hospital between 1 January 2010 and 30 June 2010 with at least one day in the ICU. RESULTS: Delirium was diagnosed in 6% (10,034 of 164,996) of hospitalizations with an ICU admission. Antipsychotics were administered to 11% (17,764 of 164,996) of patients. Of the antipsychotics studied, the most frequently used were haloperidol (62%; n = 10,958) and quetiapine (31%; n = 5,448). Delirium was associated with increased ICU LOS (5 vs. 3 days, P < 0.001) and hospital LOS (11 vs. 6 days, P < 0.001), but not in-hospital mortality (8% vs. 9%, P = 0.419). Antipsychotic exposure was associated with increased ICU LOS (8 vs. 3 days, P < 0.001), hospital LOS (14 vs. 5 days, P < 0.001) and mortality (12% vs. 8%, P < 0.001). Of patients with antipsychotic exposure in the ICU, absence of a documented mental disorder (32%, n = 5,760) was associated with increased ICU LOS (9 vs. 7 days, P < 0.001), hospital LOS (16 vs. 13 days, P < 0.001) and in-hospital mortality (19% vs. 9%, P < 0.001) compared to patients with a documented mental disorder (68%, n = 12,004). CONCLUSIONS: The incidence of documented delirium in ICU patients is lower than that documented in previous prospective studies with active screening. Antipsychotics are administered to 1 in every 10 ICU patients. When administration occurs in the absence of a documented mental disorder, antipsychotic use is associated with an even higher ICU and hospital LOS, as well as in-hospital mortality.     

Medulloblastoma in a child with fragile X syndrome

Fragile X syndrome is the most common cause of inherited intellectual impairment and has been associated with decreased incidence of cancer. We present the case of an 11-year-old boy with a diagnosis of fragile X syndrome who presented with gait imbalance, headache, and episodes of vomiting. Radiological investigation revealed the presence of a posterior fossa tumor. The patient was operated upon and the tumor proved to be a medulloblastoma (MB). To the best of our knowledge this is the first reported case of MB in a child with fragile X syndrome.     

A case of autophagia: a man who was mutilating his fingers by biting them

Self-mutilating behaviors could be minor and benign, but more severe cases are usually associated with psychiatric disorders or with acquired nervous system lesions and could be life-threatening. The patient was a 66-year-old man who had been mutilating his fingers for 6 years. This behavior started as serious nail biting and continued as severe finger mutilation (by biting), resulting in loss of the terminal phalanges of all fingers in both hands. On admission, he complained only about insomnia. The electromyography showed severe peripheral nerve damage in both hands and feet caused by severe diabetic neuropathy. Cognitive decline was not established (Mini Mental State Examination score, 28), although the computed tomographic scan revealed serious brain atrophy. He was given a diagnosis of impulse control disorder not otherwise specified. His impulsive biting improved markedly when low doses of haloperidol (1.5 mg/day) were added to fluoxetine (80 mg/day). In our patient's case, self-mutilating behavior was associated with severe diabetic neuropathy, impulsivity, and social isolation. The administration of a combination of an antipsychotic and an antidepressant proved to be beneficial.     

Skin diseases in Greek and immigrant children in Athens

Objectives This study aimed to characterize the spectrum of skin diseases affecting children in Greece. Methods We retrospectively studied data for 4071 children, aged 0–12 years, who were examined and diagnosed with dermatoses at the outpatient clinic of a university dermatological hospital between December 2005 and August 2007. To evaluate changes in disease patterns, these data were compared with data for a cohort of 12,700 children diagnosed with skin diseases at the same clinic two to three decades earlier (in 1977, 1980, and 1983). Results The most frequent disease was dermatitis/eczema (34.7%), with atopic dermatitis found in 20.7% of children, contact dermatitis in 6.9%, pityriasis alba in 2.1%, and seborrheic dermatitis in 1.8%. Infections (19.3%), nevi (5.6%), scabies (4.8%), and insect bites (4.3%) followed. More viral (12%) than bacterial (3.7%) and fungal (3.6%) infections were noted. Warts constituted 53.2% of viral infections. Immigrants had an increased risk for bacterial infections and scabies. Conclusions Children diagnosed with skin diseases 24–30 years earlier were younger; exhibited lower prevalences of dermatitis/eczema (P = 0.01), viral infections (P < 0.001) and nevi (P < 0.001); higher prevalences of bacterial and fungal infections (P < 0.001) and insect bites (P < 0.01); and similar rates of scabies (P = 0.17). This study documents the high prevalence of atopic dermatitis in the region, the increasing incidence of viral infections and nevi, and the continuing problem of scabies, especially in immigrants.     

Portal hypertension caused by acute cytomegalovirus infection with liver involvement in an immunocompetent patient

Primary infection by cytomegalovirus in immunocompetent patients is usually unapparent. We report a case of severe acute cytomegalovirus infection in a young immunocompetent male with pulmonary and hepatic involvement and portal hypertension who recovered without specific antiviral therapy with complete resolution of sonographic signs of portal hypertension after 6 months.     

Pituitary volume in unaffected relatives of patients with schizophrenia and bipolar disorder

BACKGROUND: Hypothalamic-pituitary-adrenal (HPA) axis hyperactivity has been demonstrated in both schizophrenia and bipolar disorder, but the mechanisms underlying this abnormality are still unclear. Enlarged pituitary volume has been recently reported in patients with first episode psychosis and been interpreted as a consequence of an increased activation of the HPA axis. The aim of this study was to assess the contribution of familial liability to pituitary volume in schizophrenia and bipolar disorder. Pituitary volume may be an indirect measure of HPA axis activity. METHODS: MRI brain scans and measurements of pituitary volumes were obtained for 183 subjects: 26 patients with established schizophrenia or schizoaffective disorder, 44 of their unaffected first-degree relatives (22 familial schizophrenia, 22 non-familial schizophrenia), 29 patients with established bipolar disorder, 38 of their unaffected first-degree relatives, and 46 healthy comparison subjects. RESULTS: We found a significantly larger pituitary volume (effect size=0.7) in unaffected relatives of patients with schizophrenia compared with controls (p=0.002); the pituitary was even larger in relatives of patients with familial schizophrenia (effect size=0.8, p=0.005). We did not find a significant difference in pituitary volume when comparing the relatives of bipolar patients with controls. Among patients, those with schizophrenia who were receiving prolactin-elevating antipsychotics had an increased pituitary volume compared with controls (effect size=1.0, p=0.006). CONCLUSIONS: These results suggest that the larger pituitary volume previously reported in first episode schizophrenia could be partly due to a genetic susceptibility to over-activate the HPA axis.     

Combined acute effects of red wine consumption and cigarette smoking on haemodynamics of young smokers

OBJECTIVE: Red wine seems to improve haemodynamic variables, while smoking provokes adverse effects. The haemodynamic effects of their combined use is unknown. The purpose of the present study was to examine the acute effects of red wine and its constituents, in combination with the smoking of one cigarette, on haemodynamic parameters, such as blood pressure and wave reflections, in a group of smokers. METHODS: Twenty smokers (12 males, eight females) participated in a double-blind, crossover study comprised of 3 study days. All subjects either smoked one cigarette, or smoked and drank 250 ml of red wine, or 250 ml of de-alcoholized red wine (containing the same type and similar concentration of antioxidants). Applanation tonometry and generalized transfer functions were used to estimate aortic pressure waveforms at baseline and 30, 60 and 90 min after each trial. The augmentation index (AIx) was used to express wave reflections. RESULTS: Smoking increased peripheral systolic blood pressure (P < 0.005) 30 min later, but simultaneous consumption of either type of red wine caused no such effect. Additionally, smoking caused no overall effect on AIx, while smoking and drinking either regular or de-alcoholized red wine reduced AIx (P < 0.001). The reduction of AIx after red wine consumption was significantly greater than the respective reduction after de-alcoholized red wine (P = 0.004). CONCLUSION: Antioxidant substances in red wine counteracted the smoking-induced increase in peripheral systolic blood pressure. Both alcohol and antioxidants in red wine decrease wave reflections in uncomplicated habitual smokers postprandially, indicating an additional favourable effect of red wine.