The immune response after stroke is known to play a major role in ischemic brain pathobiology. The inflammatory signals released by immune mediators activated by brain injury sets off a complex series of biochemical and molecular events which have been increasingly recognized as a key contributor to neuronal cell death. The primary immune mediators involved are glial cells and infiltrating leukocytes, including neutrophils, monocytes and lymphocyte. After ischemic stroke, activation of glial cells and subsequent release of pro- and anti-inflammatory signals are important for modulating both neuronal cell damage and wound healing. Infiltrated leukocytes release inflammatory mediators into the site of the lesion, thereby exacerbating brain injury. This review describes how the roles of glial cells and circulating leukocytes are a double-edged sword for neuroinflammation by focusing on their detrimental and protective effects in ischemic stroke. Here, we will focus on underlying characterize of glial cells and leukocytes under inflammation after ischemic stroke.

With regard to the outcome of intensive neonatal care, one of the most important concerns in neonatology is the mortality rate of very low birth weight infants (VLBWI; birth weight < 1,500 g) and extremely low birth weight infants (ELBWI; birth weight < 1,000 g). The present study was conducted to analyze and compare the mortality of VLBWI and ELBWI and neonatal care among Korean, Japanese, and American newborns. In Korea, the survival rates of VLBWI have increased significantly; they were 31.8% in the early 1960s, 65.8% in the early 1990s, 77.5% in 2002, 84.7% in 2007, and 85.7% in 2009. The survival rates of ELBWI have also increased; they were 8.2% in the early 1960s, 37.4% in the early 1990s, 56.1% in 2002, 67.7% in 2007, and 71.8% in 2009. The survival rates of VLBWI and ELBWI have significantly improved over the past 50 yr in Korea. However, the Korean survival rates of VLBWI and ELBWI are still lower than for similar groups in Japan and the USA. To achieve better outcomes that reach the level of these countries, the organization of perinatal care centers, nationwide neonatal perinatal research networks, and regionalization are needed in Korea.

Neonatal mortality rate (NMR) and infant mortality rate (IMR) are two of the most important indices reflecting the level of public health of a country. In this review, we investigated changes in NMR and IMR in Korea and compared the results with those of Japan, USA, and OECD nations. During the past 20 yr, NMR and IMR have lowered remarkably from 6.6 and 9.9 in 1993 to 1.7 and 3.2 in 2009, respectively, in Korea. It is an impressive finding that Korean IMR (3.2 in 2009) is lower than the average of OECD nations (4.7 in 2008), and USA (6.3 in 2009), although higher than Japanese IMR (2.8 in 2009). The proportion of NMR among the IMR calculation decreased from 66.7% in 1993 to 53.1% in 2009. The reason the value of Korea was higher than Japan but lower than USA was speculated to be an aspect of the health care service system. Several suggestions in perinatal, neonatal and infantile health care such as establishment of perinatal care center, research network system, regionalization, and new policies for care of pre-term and high risk pregnancy, are elucidated to achieve further improvement on NMR and IMR in Korea.

The aim of this study was to survey multiple birth data and to analyze the recent trends of multiple births and its consequences on perinatal problems in Korea from 1991 to 2008. Data were obtained from the Korean Statistical Information Service. The total number of multiple births showed increasing trends. The multiple birth rate was maintained within less than 10.0 for the decade from 1981 to 1990. However, it increased gradually to reach 27.5 in 2008. The maternal age for multiple births was higher than for total live births. The mean birth weight of the total live births was 3.23 kg; for the multiple births it was 2.40 kg in 2008. The incidence of low birth weight infants (LBWI) among total live births was 3.8% in 2000 and 4.9% in 2008. For multiple births it was 49.2% and 53.0% during the same years. The incidence of preterm births among total live births was 3.8% in 2000 and 5.5% in 2008; for the multiple births it was 38.3% and 51.5% during the same years. The incidence of multiple births and its consequences on perinatal problems (preterm, LBWI, and advanced-maternal age) have been increased steadily over the last two decades in Korea.

The immune response following neuroinflammation is a vital element of ischemic stroke pathophysiology. After the onset of ischemic stroke, a specialized vasculature system that effectively protects central nervous system tissues from the invasion of blood cells and other macromolecules is broken down within minutes, thereby triggering the inflammation cascade, including the infiltration of peripheral blood leukocytes. In this series of processes, blood-derived monocytes have a significant effect on the outcome of ischemic stroke through neuroinflammatory responses. As neuroinflammation is a necessary and pivotal component of the reparative process after ischemic stroke, understanding the role of infiltrating monocytes in the modulation of inflammatory responses may offer a great opportunity to explore new therapies for ischemic stroke. In this review, we discuss and highlight the function and involvement of monocytes in the brain after ischemic injury, as well as their impact on tissue damage and repair.