Chronological changes of serum exosome in preterm infants: A prospective study.

BACKGROUND: Exosomes, which are observed in all human fluid, including serum, are nanosized extracellular vesicles with a mechanism of intercellular communication. Potential clinical applications of exosomes in neonatal diseases have recently been discussed. However, the characteristics of exosomes in serum during early infancy is unclear. METHODS: In this prospective study, we evaluated the chronological changes in the concentration of serum-derived exosomes of 20 infants for 12 months after birth. RESULTS: The average concentration of serum-derived exosomes was 4.6 × 1010 particles/mL at birth and increased significantly until the age of 48 weeks. There was a moderate correlation between the gestational age and the concentration of serum-derived exosomes both at birth (r = 0.54, P = 0.01) and during the 8 weeks after birth (r = 0.48, P < 0.001). A multivariable analysis showed that gestational age at birth was associated with the concentration of serum-derived exosomes at birth (partial regression coefficient, 0.86; 95% confidence interval, 0.37-1.37; P = 0.002). CONCLUSIONS: The concentration of serum-derived exosomes in preterm infants increased both chronologically and by gestational age after birth. These basic data may help to further understand physiology of exosomes in preterm infants.

Cyclo-oxygenase-1 and -2 expression in human oral mucosa, dysplasias and squamous cell carcinomas and their pathological significance.

Cyclo-oxygenase (COX) is a key enzyme in the conversion of arachidonic acid to prostanoids. The expression of its isoforms, COX-1 and -2 is found in many human malignancies. This study analyzed the correlation between COX expression and the pathobiological nature of human oral mucosa, dysplasias and squamous cell carcinomas (SCCs). We examined 9 specimens of normal oral epithelia, 65 lesions with dysplasias and 50 SCCs. Labeling indices (LIs) for COX-1, COX-2, Ki-67 and P53, microvessel density (MVD) and apoptotic index (AI) were evaluated using immunohistochemistry and TUNEL methods. Western blot analysis of COX-1 and -2 was performed on four human oral SCC cell lines, all of which showed expression. The LIs for COX-1 and -2 were higher for the dysplasias than the SCCs. LIs of COX-2 but not COX-1 correlated with the histological grade of dysplasia, being highest for the severe dysplasias (p < 0.05). In contrast, the COX-2 LIs as well as COX-1 were significantly (p < 0.05) inversely correlated with the histological differentiation of the SCCs. COX-2 expression was significantly correlated with LIs of COX-1 for dysplasia (p < 0.05), but not for the SCCs. In addition no significant relationship was noted between COX-2 expression and the Lis of Ki-67, P53, AI as well as MVD for the dysplasias and SCCs. The expression of COX-1 and -2 is correlated with early stage tumorigenesis and cellular differentiation of SCCs in the oral dysplasia-carcinoma sequence.