Several studies have indicated MUC to be an

Several studies have indicated MUC1 to be an effective marker for identifying various malignant tumors, such as gastric, breast, pancreatic, ovarian, gallbladder, uterus, lung, and prostate cancers, as well as for prognostic outcomes [16], [17], [18], [19], [20], [21], [22], [23]. Studies by Kaira et al. [10] confirmed MUC1 to be a useful marker for differentiating type B3 thymoma from thymic carcinoma. In their study, all the 5 patients with type B3 thymoma were MUC1-negative and 94% of the patients (16/17) with thymic carcinomas were MUC1-positive. They further concluded that MUC1 is feasible to use in small biopsy specimens, as 13 out of 16 patients in their group diagnosed by core needle biopsy have a positive MUC1 expression. By contrast, Kojika et al. [9] claimed that the low sensitivity of 33% in their study may not support the use of MUC1 in small biopsy specimen. In our current study, no core needle biopsy specimens were used, and the sensitivity and the specificity of MUC1 were 77.27% (17/22) and 89.47% (17/19), respectively. Thus, although MUC1 had a generally higher sensitivity for the identification of thymic carcinomas across different studies, its use in small biopsy specimens should be taken prudently. Noticeably, it would appear that MUC1 has a higher specificity (89.47%) across different studies. Among the four markers shown in Table 4, GLUT1 showed the highest sensitivity and MUC1 showed the highest specificity.
Introduction Brain endothelial cells, an essential element of the blood-brain barrier, express the glucose transporter (GLUT)-1 to uptake glucose from the blood circulation. In particular, the endothelium in the neonatal salvinorin a expresses more intensely monocarboxylate transporter (MCT)-1 than GLUT1 in order to respond to the special energy supply since neonates largely depend on monocarboxylates such as ketone bodies and lactate derived from milk to serve as energy sources (Gerhart et al., 1997, Pellerin et al., 1998). Actually, the concentration of ketone bodies and lactate in the brain circulation is high in rodents during the suckling period but lowers after the weaning period (Vannuci and Simpson, 2003). MCT1, the first identified member of the MCT family (Garcia et al., 1994), comprises membrane-bound channels that transport lactate, ketone bodies, and other monocarboxylates—along with protons (pH), down their concentration gradients (for review, Halestrap and Meredith, 2004, Halestrap, 2012, Halestrap, 2013). In adults, all of the blood-tissue barriers maintain the expression of both MCT1 and GLUT1, as represented by the retinal pigment epithelium and brain vascular endothelium (Iwanaga and Kishimoto, 2015). The ocular vascular system in developmental stages is characterized by the existence of the hyaloid vascular system, which regresses during the later developmental stages of the eyes. The hyaloid artery, a branch of the opthalamic artery, enters inside the fetal eyes through the optic disc, branches off, and runs toward the lens via two routes. A bundle of blood vessels that continues in a straight course from the hyaloid artery reaches the posterior pole of the lens to form the tunica vasculosa lentis (TVL) (Cairns, 1959, Hida, 1982). The vessels of TVL radiate spokewise and wholly cover the posterior surface of the lens. Another group of vessels branching at the proximal position extends in the vitreous along the internal surface of the retina to yield the vasa hyaloidea propria (VHP). The VHP nourish the avascular inner retina and produce the primary vitreous, but their regress is earlier than other hyaloid vascular systems (Jack, 1972, Hida, 1982, Ito and Yoshioka, 1999), the regression process coinciding with the development of the proper retinal vessels (Cairns, 1959, Ashton, 1968). Some branches of VHP anastomose with the TVL at the equator of the lens. In the later stages of ocular development, the central retinal artery radiates into six arterial branches to construct a permanent vascular system for directly supplying the blood to the inner retina. Sprouting angiogenesis is predominant as the mode of development of the retinal vasculature, though some studies opt for vasculogenesis with the formation of blood islands (McLeod et al., 2012; also see Saint-Geniez and D'Amore, 2004). The retinal vascular system provides a suitable sample for studies of angiogenesis or vasculogenesis, due to the easy preparation of whole mount preparations for overviewing. The hyaloid vessels possess tight junctions between endothelial cells that limit diffusion into the perivascular space (Braekevelt and Hollenberg, 1970, Townes-Anderson and Raviola, 1982), suggesting a need for transporters specific for each nutrient, like the blood-brain barrier. However, no information is available regarding the expression of MCTs and GLUTs in the angiogenesis of ocular tissues, and the question arises as to when predominant nutrient transporters switch during development. Studies on the retinal angiogenesis have focused on specific angiogenic molecules such as platelet-derived growth factor (PDGF) (Fruttiger et al., 1996) and vascular endothelial growth factor (VEGF) (Gerhardt et al., 2003), guidance by neuronal/glial elements (Fruttiger et al., 1996, Zhang and Stone, 1997), adhesion molecules including R-cadherin (Dorrell et al., 2002), and chemokines (Strasser et al., 2010).