Development of cortical interneurons continues until the end of human pregnancy. Premature birth deprives the newborns from the supply of maternal estrogen and a secure intrauterine environment. Indeed, preterm infants suffer from neurobehavioral disorders. This can result from both preterm birth and associated postnatal complications, which might disrupt recruitment and maturation of cortical interneurons. We hypothesized that interneuron subtypes, including parvalbumin-positive (PV), somatostatin-positive (SST), calretinin-positive (CalR), and neuropeptide Y-positive (NPY) interneurons, were recruited in the upper and lower cortical layers in a distinct manner with advancing gestational age. In addition, preterm birth would disrupt the heterogeneity of cortical interneurons, which might be reversed by estrogen treatment. These hypotheses were tested by analyzing autopsy samples from premature infants and evaluating the effect of estrogen supplementation in prematurely delivered rabbits. The PV and CalR neurons were abundant, whereas SST and NPY neurons were few in cortical layers of preterm human infants. Premature birth of infants reduced the density of PV or GAD67 neurons and increased SST interneurons in the upper cortical layers. Importantly, 17 β-estradiol treatment in preterm rabbits increased the number of PV neurons in the upper cortical layers relative to controls at postnatal day 14 (P14) and P21 and transiently reduced SST population at P14. Moreover, protein and mRNA levels of Arx, a key regulator of cortical interneuron maturation and migration, were higher in estrogen-treated rabbits relative to controls. Therefore, deficits in PV and excess of SST neurons in premature newborns are ameliorated by estrogen replacement, which can be attributed to elevated Arx levels. Estrogen replacement might enhance neurodevelopmental outcomes in extremely preterm infants. Premature birth often leads to neurodevelopmental delays and behavioral disorders, which may be ascribed to disturbances in the development and maturation of cortical interneurons. Here, we show that preterm birth in humans is associated with reduced population of parvalbumin-positive (PV) neurons and an excess of somatostatin-expressing interneurons in the cerebral cortex. More importantly, 17 β-estradiol treatment increased the number of PV neurons in preterm-born rabbits, which appears to be mediated by an elevation in the expression of Arx transcription factor. Hence the present study highlights prematurity-induced reduction in PV neurons in human infants and reversal in their population by estrogen replacement in preterm rabbits. Because preterm birth drops plasma estrogen level 100-fold, estrogen replacement in extremely preterm infants might improve their developmental outcome and minimize neurobehavioral disorders.
Generic DAAs are effective and safe in TM adolescents with HCV.
Prematurely born infants are deprived of maternal hormones and cared for in the stressful environment of Neonatal Intensive Care Units (NICUs). They suffer from long-lasting deficits in learning and memory. Here, we show that prematurity and associated neonatal stress disrupt dentate gyrus (DG) development and induce long-term cognitive deficits and that these effects are mediated by insulin growth factor-1 (IGF1). Nonmaternal care of premature rabbits increased the number of granule cells and interneurons and reduced neurogenesis, suggesting accelerated premature maturation of DG. However, the density of glutamatergic synapses, mature dendritic spines, and synaptic transmission were reduced in preterm kits compared with full-term controls, indicating that premature synaptic maturation was abnormal. These findings were consistent with cognitive deficits observed in premature rabbits and appeared to be driven by transcriptomic changes in the granule cells. Preterm kits displayed reduced weight, elevated serum cortisol and growth hormone, and higher IGF1 expression in the liver and DG relative to full-term controls. Importantly, blocking IGF-1 receptor in premature kits restored cognitive deficits, increased the density of glutamatergic puncta, and rescued NR2B and PSD95 levels in the DG. Hence, IGF1 inhibition alleviates prematurity-induced cognitive dysfunction and synaptic changes in the DG through modulation of NR2B and PSD95. The study identifies a novel strategy to potentially rescue DG maldevelopment and cognitive dysfunction in premature infants under stress in NICUs.
A 33-year-old man of a Middle Eastern origin presented to us with abdominal pain and distension secondary to refractory ascites of 1-month duration. The patient had a history of taking oral retinoic acid 25 mg for 4 months for mycosis fungoides. Investigations revealed thrombosis of hepatic veins with extensive thrombosis of the porto-mesenteric axis. A combination of transjugular intrahepatic portosystemic shunt, balloon angioplasty and thrombolysis with recombinant tissue plasminogen activator was successfully used to treat his condition.
Spondyloarthritis presents in various and occasionally unusual ways that imitates other diseases. Without forthcoming risk factors, such atypical presentation may elude diagnosis for months. The case presented here of a child, aged 4 years, who is negative for human leukocyte antigen B27 (HLA-B27) and with no family history of HLA-B27 related disease, who developed torticollis with neck pain and lymphadenopathy, highlights the necessity of continually evaluating a diagnosis, especially when treatment fails to produce expected results. Painful torticollis in a child with adenopathy often is infectious in nature or potentially due to Griesel syndrome when persistent. Chronic arthritis of the cervical spine may enter the differential diagnosis when torticollis is persistent, and early recognition and aggressive treatment is necessary to prevent permanent functional impairment.
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