Eiko Murata

Unilateral anomalous left common carotid artery; a case report.

An anomaly of the left common carotid artery was observed in a Japanese male cadaver during an anatomy class at the Saitama Medical School in 1995. The superior thyroid, lingual and facial arteries arose from the common carotid artery, and the posterior auricular, maxillary and superficial temporal arteries arose from the common carotid artery by a common trunk. The occipital and ascending pharyngeal arteries arose from the internal carotid artery. The left carotid body (glomus caroticum) was observed to be slightly below the lingual artery, behind the common carotid artery, and it was located at the level of the intervertebral disk between C2 and C3 or at the same level as the right carotid body. The carotid body was richly innervated by a branch of the glossopharyngeal nerve and by a plexus of sympathetic fibers from the vagus and glossopharyngeal nerves. We assumed that the artery above the level of the carotid body was the internal carotid artery; there was no specific external carotid artery and all branches of the external carotid artery arose from the internal carotid artery.

ROLES OF MACROPHAGES IN PROGRAMMED CELL DEATH AND REMODELING OF TAIL AND BODY MUSCLE OF XENOPUS LAEVIS DURING METAMORPHOSIS

Abstract Examination was made of the involvement of macrophage phagocytosis in programmed cell death of tail and body muscle of the frog, Xenopus laevis, during metamorphosis by electron microscopy and immunohistochemical analysis. Electron microscopic observation revealed that macrophages were often found to be present in body and tail muscles at the most active stage of metamorphosis and to actively phagocytose apoptotic muscle fragments. Developmental changes in macrophages were examined using the macrophage-specific antibody, HAM56. Macrophages initially appeared in the early climax stage (stage 59), when the triiodothyronine (T3) level was high, increased rapidly during the process of muscle cell death, and assumed their greatest number at the late climax stage (stage 63/64). They decreased after stage 65/66, with a decrease in T3. Distribution and change in the number of macrophages were the same as those of muscle apoptotic bodies (sarcolytes) during metamorphosis, which suggests an interactive mechanism between macrophages and dying muscle cells. For clarification of this, study was made of the expression of HAM 56 antigens that were X. laevis homologs of mouse attachmin, non-specific adhesion proteins in macrophages. The expression of HAM56 antigens in macrophages was found to increase with macrophage phagocytosis at the late climax stage, thus, macrophage differentiation would appear to take place during metamorphosis and HAM56 antigens may be essential for macrophage–dying muscle cell interactions.

Suppression of BMP-Smad signaling axis-induced osteoblastic differentiation by small C-terminal domain phosphatase 1, a Smad phosphatase.

Bone morphogenetic proteins (BMPs) induce osteoblastic differentiation in myogenic cells via the phosphorylation of Smads. Two types of Smad phosphatases--small C-terminal domain phosphatase 1 (SCP1) and protein phosphatase magnesium-dependent 1A--have been shown to inhibit BMP activity. Here, we report that SCP1 inhibits the osteoblastic differentiation induced by BMP-4, a constitutively active BMP receptor, and a constitutively active form of Smad1. The phosphatase activity of SCP1 was required for this suppression, and the knockdown of SCP1 in myoblasts stimulated the osteoblastic differentiation induced by BMP signaling. In contrast to protein phosphatase magnesium-dependent 1A, SCP1 did not reduce the protein levels of Smad1 and failed to suppress expression of the Id1, Id2, and Id3 genes. Runx2-induced osteoblastic differentiation was suppressed by SCP1 without affecting the transcriptional activity or phosphorylation levels of Runx2. Taken together, these findings suggest that SCP1 may inhibit the osteoblastic differentiation induced by the BMP-Smad axis via Runx2 by suppressing downstream effector(s).

Reorganized small intestine from fetal mouse as an in vitro wound healing model

Background. We developed a method for reorganizing the mouse small intestine. In the present study, we investigated whether the reorganized small intestine was morphologically and histochemically differentiated. We also evaluated the reorganized small intestine as an in vitro wound healing model. Methods. Fetal mouse small intestines were dispersed into single cells, which were then cultured to a high density. Newly formed small intestine-like organs on a membrane filter were observed by light and electron microscopy. Alkaline phosphatase (ALPase) activity of the epithelium was analyzed. To evaluate the reorganized small intestine as an in vitro wound healing model, a scalpel was used to cut the reorganized intestine on a membrane, and the healing process was morphologically and immunohistochemically examined. Results. After 6 days in culture, the surface was almost completely coveed with epithelial cells, and villus-like structures were observed. These epithelial cells formed microvilli, and in parallel with this development, ALPase activity of the microvilli increased (from day 4). Twenty-four hours after the cutting, the wound surface was almost completely covered with undifferentiated epithelial cells. The number of acetylated low-density lipoprotein labeled with 1,1,dioctadecyll,3,3,3,3, tetramethyl-indocarbocyanine perchlorate (DiI-Ac-LDL)-positive macrophages increased after cutting. Platelet-derived growth factor (PDGF)-, basic fibroblast growth factor (bFGF)-, matrix metalloproteinase-1 (MMP-1)-positive cells were detected by immunohistochemical staining. Conclusions. The reorganized small intestine had a morphologically and histochemically differentiated organoid structure, and was useful as an in vitro model for investigating the process of wound healing.

Immuno-electron-microscopic application of antiserum against elastin

The antiserum against insoluble elastin from human aorta was applied to immuno-electron microscopy. In the preembedding method, only the outer surface of the amorphous component (elastin) of elastic fibers showed a positive reaction. A major problem encountered with the preembedding method is associated with the penetration of either the primary antiserum or the secondary antibody into the tissue and, in particular, into elastin. On the contrary, a positive reaction was observed inner zones of elastin in the postembedding method. While the postembedding method employed here has limitations with nonspecific binding to the embedding medium, the postembedding method offers a decided advantage over the preembedding method.

A New Method Using a Modified Mayer's Hemalum at pH 6 for Demonstrating Mucous Neck Cells

The mucous neck cells of gastric glands were stained with a modified Mayers hemalum adjusted to pH 6 with saturated aqueous lithium carbonate. One gram of hematoxylin was dissolved in 1000 ml distilled water and 200 mg sodium iodate, 3 g potassium alum, 50 g chloral hydrate and 1 g citric acid were added to the solution. Prior to staining, the solution was adjusted to pH 6 with saturated aqueous lithium carbonate. Bromine oxidation and urea abolished the alum hematoxylin reactivity of the mucous neck cells.