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Purpose: To determine if the corneas of naive mice contain resident CD4+ and CD8+ T cells., Methods: The presence of T cells in the corneas of naive BALB/c, C57BL/6, and SCID mice was determined by immunostaining with anti-CD4 (clone RM4-5) and anti-CD8 (clone 5H10-1) monoclonal antibodies. Immunostained corneal sections were examined by light microscopy, and immunostained intact corneas were examined by confocal microscopy. The levels of CD4 and CD8 mRNA transcripts in the corneas were determined by TaqMan reverse-transcriptase polymerase chain reaction (RT-PCR) analysis and compared with the expression of these transcripts in the corneas of HSV-1 infected mice. Finally, the number of CD4+ and CD8+ T cells in the cornea of BALB/c, C57BL/6, and ICR mice was determined by cell sorting., Results: Both light microscopic examination of corneal sections and confocal microscopic examination of intact corneas revealed the presence of CD4+ and CD8+ cells in the central and peripheral regions of the corneas of BALB/c and C57BL/6 mice. Stained cells were not detected in corneas of control SCID mice. CD4 and CD8 mRNA transcripts were detected in corneas of BALB/c and C57BL/6 mice while there were markedly lower levels of transcripts in SCID mice. The number of CD4 transcripts was lower than the number of CD8 transcripts in the corneas of both BALB/c and C57BL/6 mice. Finally, cell sorting showed the presence of both CD4+ and CD8+ T cells in corneas of BALB/c, C57BL/6, and ICR mice., Conclusions: CD4+ and CD8+ T cells are present in corneas of naive C57BL/6, BALB/c, and ICR mice.

Mouse embryos were explanted at 11.5 days of gestation and cultured for periods of 6, 12, 18, 24, 30, 36, 42 and 48 hours using the whole embryo culture system. A continuous flow of gas (5% CO2+95%O2) was maintained through the culture bottles during the culture periods. The cultured embryos were morphologically and histologically examined at the end of the designated periods. The growth of the embryos was depressed after about 36 hours, and differentiation was retarded as the culture time increased. General development had ceased almost completely by 42-48 hours. At 18-36 hours, the external auditory canal and pinna, which are not developed in 11.5 day embryos, could be observed clearly on the surface of the head. After 42 hours, the facial features including the external ear were similar to those of 13 day in vivo embryos. Serial sections of the ear region of cultured embryos showed that development of the inner and middle ear structures up to 42 hours was the same as that seen from 11.5 to 13 days in vivo. In the inner ear, the otocyst had developed into the vestibule, cochlea and semicircular canals by 12-30 hours. In the middle ear, the stapedial anlage appeared and its circular shape became clear between 0 and 12 hours. Subsequently, the medial portion of the stapedial anlage grew until it was adjacent to the developing otic capsule, and the anlages of other ossicles were also recognizable after 18 hours. Differentiation of the horizontal portion of the facial nerve was noted at the same time that stapedial anlage and otic capsule were developing.(ABSTRACT TRUNCATED AT 250 WORDS)

The intestinal Peyer's patches (PP) were significantly different in distribution and fine morphology between Mongolian gerbils and mice. The PP of gerbils were evenly distributed from the duodenum to ileum, whereas the PP of mice were more densely distributed in the lower ileum than other parts of the intestine. In gerbils, each PP had a much greater number of lymphoid follicles than in mice, although the total number of PP was smaller. Electron microscopy revealed that the PP dome of gerbils was covered with two types of epithelial cells, one with shorter microvilli and the other with longer ones, whereas the epithelial cells of the murine PP dome was uniform-shaped with numerous medium-sized microvilli. Some dome absorptive cells of gerbils were morphologically similar to poorly differentiated crypt cells of mice, suggesting to be immature M cells.

This study provides new information concerning the distribution of cartilage collagens in neonatal mammalian condylar cartilage. It became apparent that young cartilage cells contain pro-Type I collagen as well as pro-Type II collagen. The mature molecule of Type I collagen appears only in the extracellular matrix of the mineralisation zone close to the ossification front. Type II collagen, on the other hand, is apparent throughout the extracellular matrix as soon as the chondroprogenitor cells have differentiated into chondroblasts. In addition, Type II collagen is noticed in the core of the newly formed bone trabeculae within the primary spongiosa. Type IX collagen was found to be co-distributed with Type II collagen in cartilage and bone. Hypertrophic chondrocytes within the mineralisation zone, but in no other zone, demonstrate an intense reactivity for Type X collagen. Mild reactivity throughout the condylar process is encountered with regard to Type VI collagen. Perichondrium but not cartilage reacts positively for Type III collagen.