Astrocytes in the damaged brain: Molecular and cellular insights into their reactive response and healing potential

Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.     

Is uterine artery embolization for cervical ectopic pregnancy always safe?

The study objective was to assess the feasibility and the efficacy of bilateral uterine artery embolization (BUAE) for the treatment of cervical pregnancy. The design was a series of 3 cases of viable cervical pregnancy diagnosed by transvaginal ultrasonography and treated by means of BUAE and subsequent uterine curettage. Three women with viable cervical pregnancy underwent BUAE and subsequent uterine curettage in the department of obstetrics and gynecology, High Risk Pregnancy Center, University "Federico II" of Naples. Measurements included surgical outcomes and preservation of fertility. The treatment was effective in all cases. Two patients resumed normal menstruation about 1 month after the procedure, whereas 1 patient underwent a hysterectomy 2 weeks after embolization because of acute ischemic degeneration of a concomitant myoma. The conservative management of cervical pregnancy with angiographic BUAE is a feasible and effective option, even if subsequent hysterectomy may be required. Counseling is necessary.     

A new familial sclerosing bone dysplasia

Osteoscleroses are a heterogeneous group of bone remodeling disorders characterized by an increase in bone density. Here we report on a consanguineous Lebanese family in which two sisters, aged 39 and 36 years, exhibit a severe genu varum, a square‐face appearance, high forehead, slight proptosis of the eyes, symmetric enlargement of the jaw, protruding chin, and short stature. Bone X‐rays showed the presence of hyperostosis of the cranial base and vault with increased density of the orbits, hyperostosis of the bones, thickening of the cortices, diaphyseal modeling defects, cortical thickening of the medullary cavity, mild enlargement of the medullary cavity of the short long bones, short femoral necks, increased width of the ribs, and narrow interpedicular distances of the lower lumbar spine. Osteodensitometry showed values 200% to 300% above values for age. A cervical MRI revealed the presence of a diffuse osteosclerosis with calcification of the posterior vertebral ligament and a narrow canal between C2 and T2. Blood test results were unremarkable. Serum osteocalcin levels were in the normal range, whereas high values of serum C ‐ telopeptide were noted. A bone biopsy showed only the presence of compact bone and did not allow for histomorphometric analysis. Molecular studies excluded genes known to be involved in sclerosing bone dysplasias as the cause of this condition. In vitro analysis of osteoclast function indicated that contrary to most cases of autosomal recessive osteopetrosis, osteoclasts both formed and resorbed but exhibited a small decrease in resorptive activity compared with osteoclasts generated from normal control individuals. Differential diagnoses are discussed, and the possibility that this may be a novel clinical entity is raised. © 2010 American Society for Bone and Mineral Research.     

Transepidermal Water Loss in Newborns Within the First 24 Hours of Life: Baseline Values and Comparison with Adults

The measurement of transepidermal water loss (TEWL) is important for evaluating the integrity of the barrier function of the stratum corneum. Normal TEWL values in healthy adults and in children ages 2 and older are well known, but few studies have been performed in infants and neonates. TEWL in healthy neonates younger than 24 hours old was assessed and compared with that of an adult study population. We also studied possible correlations between this parameter, gestational age, and mode of delivery. A prospective study was conducted in healthy newborns. The areas tested were the volar forearm and the popliteal fossa. Ninety‐nine healthy newborns were enrolled and 33 healthy adults were analyzed as controls. Statistically significant differences were noted between newborns and adults in TEWL (p < 0.01). Newborns had a much higher mean TEWL than adults. Differences in the morphology and physiology between newborn and mature skin can explain the higher TEWL in newborns. Higher TEWL could also be due to the sudden functional adaptation of the skin immediately after delivery, when the newborn transits from a liquid to the dry, gaseous extrauterine environment. Functional evaluation of the neonatal skin barrier is important mainly because maintaining skin integrity facilitates cutaneous adaptation.     

Physical Activity in Liver Transplantation: A Patient's and Physicians’ Experience

Liver transplantation has become a highly standardized, acceptable option for selected patients with end-stage liver disease and/or hepatocellular carcinoma in the setting of cirrhosis. Both conditions are associated with loss of skeletal muscle mass (sarcopenia) and physical deconditioning. Both conditions result in a dramatic decrease in the patients’ quality of life, negatively impacting on the pre- and post-transplant prognosis. In this context, awareness of the advantages of physical activity in both the pre- and post-transplant setting is key. However, the importance of regular, individualized and patient-adapted physical activity is still understudied and underestimated. This article describes a three-sided perspective on the importance of physical activity in the setting of liver transplantation, including a patient's, transplant surgeon's and hepatologist’s point of view.