Chuog Shin

Microanatomy of the incisive canal using three-dimensional reconstruction of microCT images: An ex vivo study

OBJECTIVES The purpose of this study was to investigate the general structure of the incisive canal (IC) using 3-dimensional reconstruction and to classify into various types according to several criteria. STUDY DESIGN The materials used in the study were 56 anterior maxillae harvested from human cadavers. The specimens were scanned with microscopic computerized tomography (microCT), and the resulting microCT images were reconstructed in 3 dimensions. RESULTS Many ICs had 1 foramen inferiorly and 2 foramina superiorly, and the separating level was just beneath the nasal floor. The middle part of the IC was not always a single hollow canal. Single-channel, 2-channel, 3-channel, and even 4-channel ICs were observed. The ICs were classified into 4 types according to the lateral shape of the canal: vertical-straight, vertical-curved, slanted-straight, and slanted-curved. CONCLUSIONS This study disclosed the detailed morphologic features of the IC, which will be helpful in the placement of local anesthesia or implants.

A new model for the morphology of the arrector pili muscle in the follicular unit based on three‐dimensional reconstruction

In the classic model of the arrector pili (AP) muscle, each hair follicle is independently associated with a single AP muscle. Recently, new models have been proposed based on interpretations of serial histological cross‐sectional images. The purpose of this study was to confirm the morphology of the AP muscle in relation to the follicular unit (FU) using quantitative three‐dimensional (3D) reconstruction of serially sectioned images. Skin samples were obtained from the parietal region of the scalp, and processed using routine histological procedures. The serially sectioned slides were stained with Massons trichrome. All the hairs and hair follicles of the FU exhibited some degree of slanting, with the single AP muscle slanted in the same direction. The distal portion of the AP muscle was divided into branches, as in a bronchial tree. There was branching in the single AP muscle present in the FU, and it was inserted into all the hair follicles of the FU either tightly or loosely. We suggest that the classic anatomy of the AP muscle must be modified with this new model, now confirmed by computer‐based 3D reconstruction.

Spinal root origins and innervations of the suprascapular nerve

The suprascapular nerve branches provide efferent innervation to the supraspinatus and infraspinatus muscles as well as sensory innervation to the shoulder joint. This study was carried out to verify the spinal root origins and innervations of the suprascapular nerve. Fifty samples of the suprascapular nerve taken from 37 adult Korean cadavers were used in this study. The suprascapular nerve was found to comprise the ventral rami of the C5 and C6 in 76.0% of the fifty samples; C4, C5, and C6 nerves in 18.0%; and C5 nerve in only 6.0%. The C5 nerve was consistently shown to be the largest in mean diameter and was found to be a major contributor of nerve fibers leading to the suprascapular nerve. This study shows that the main spinal component of the suprascapular nerve is C5 nerve. In most cases, the rate of the involvement of the C4 and C6 nerves (18.0 and 94.0%, respectively) with the suprascapular nerve was less than that of C5 nerve. C4 and C5 nerves were shown to contribute nerve fibers to the supraspinatus and infraspinatus muscles and to both shoulder joints, whereas C6 nerve displayed variable patterns of innervation.

Quantitative Analysis of the Cochlea using Three-Dimensional Reconstruction based on Microcomputed Tomographic Images

The aim of this study was to provide data on various dimensions of the normal cochlea using three‐dimensional reconstruction based on high‐resolution micro‐CT images. The petrous parts of 39 temporal bones were scanned by micro‐computed tomography (CT) with a slice thickness of 35 μm. The micro‐CT images were used in reconstructing three‐dimensional volumes of the bony labyrinth using computer software. The volumes were used to measure 12 dimensions of the cochlea, and statistical analysis was carried out. The dimensions of cochleae varied widely between different specimens. The mean height and length of the cochlea were 3.8 and 9.7 mm, respectively. The angle between the basal and middle turns was slightly larger in males than in females, while none of the other 11 dimensions differed significantly between males and females. The cochlear accessory canals were observed in about half of the cases (51.3%). Correlation analysis among measured items revealed positive correlations among several of the measured dimensions. The present study could investigate the detailed anatomy of the normal cochlea using high‐resolution imaging technologies. The results of the present study could be helpful for the precise diagnosis of congenital cochlear malformations and for producing optimized cochlear implants. Anat Rec, 296:1083–1088, 2013.

Structural and optical properties in ZnTe/GaAs strained heterostructures grown by temperature‐gradient vapor transport deposition

A lattice‐mismatched ZnTe epilayer on a GaAs(100) substrate was grown by the simple method of temperature‐gradient vapor deposition. X‐ray diffractometry measurements were performed to investigate the structural properties of the ZnTe layer. Raman spectroscopy measurements showed that there was a lattice mismatch between the ZnTe epitaxial layer and the GaAs substrate. Reflectivity and photoreflectance measurements clearly revealed the splitting of the valence‐band maximum, and photoluminescence measurements showed several resonant excitations of the ZnTe. The binding energies of the light holes and heavy holes determined from the splittings are in reasonable agreement with the bulk values.

Destination of the C4 component of the prefixed brachial plexus.

This study was carried out to elucidate the destination of the C4 ventral ramus that forms the prefixed brachial plexus. A total of 43 sides of Korean adults (male, 22; female, 18; unknown: 3 and right, 23; left, 20) were investigated. The various C4 destinations and their frequencies were as follows: suprascapular nerve, 97.7% (42/43); musculocutaneous nerve, 79.1% (34/43); the axillary nerve, 48.8% (21/43); and the nerve to subclavius, 16.2% (7/43). The mean quantity of nerve fibers destined to the suprascapular, musculocutaneous, and axillary nerves and the nerve to subclavius was 441.8 ± 316.5 (Mean ± S.D.), 298.2 ± 209.8, 245.8 ± 239.0, and 66.4 ± 17.2, respectively. The mean nerve fibers number of C4 contributing to the brachial plexus was 983.6 ± 618.0 (range: 100–1729). The main component that contributes to the terminal nerves (suprascapular, musculocutaneous, axillary nerves, and nerve to subclavius) is C5. These results may be useful to surgeons and clinicians dealing with terminal nerves of the brachial plexus, especially the suprascapular, musculocutaneous, and axillary nerves. Clin. Anat. 24:717–720, 2011.

An abnormal muscle in the superficial region of the popliteal fossa

An abnormal muscle was observed in the superficial region of the popliteal fossa during a dissection procedure conducted for medical students. This abnormal muscle originated from the biceps femoris tendon and inserted into the medial head of the gastrocnemius muscle. The innervating nerve branched from the lateral sural cutaneous nerve. The distributing artery arose from a branch of the sural artery. This abnormal muscle mostly comprised one sheet of muscle mass (not tendon type) and ran transversely.

Note: A PCR-Based Analysis of Hox Genes in an Earthworm, Eisenia andrei (Annelida: Oligochaeta)

Homeobox-containing genes consist of a large family of genes encoding transcription factor proteins. A motif of 60 amino acids termed the homeodomain (homeobox at the nucleotide level) has been intensively studied in order to elucidate the molecular mechanism of the specification of body pattern during normal development, differentiation, as well as regeneration (Gehring et al., 1990; Scott et al., 1989). One family of homeobox-containing genes (the Hox genes) plays a pivotal role in the determination of the axial properties in many animal species. Since amino acid sequences within the homeodomain proteins are highly conserved through evolution and are distributed over a wide phylogenetic spectrum, the reconstruction of the evolution of Hox gene organization would provide valuable information on animal phylogeny. In annelids, Hox genes of the leech have been most extensively investigated. The identification, expression pattern, and possible function of the Hox genes of the leech have been demonstrated (Irvine and Martindale, 1996; Shankland et al., 1997). In polychaete, another annelid, it has been suggested that Hox cluster genes are expressed in set-aside cells from which the adult body plan is derived (Peterson et aI., 2000). The expression patterns of posterior as well as anterior

A new earthworm cellulase and its possible role in the innate immunity.

ABSTRACT A new endogenous cellulase (Ean‐EG) from the earthworm, Eisenia andrei and its expression pattern are demonstrated. Based on a deduced amino acid sequence, the open reading frame (ORF) of Ean‐EG consisted of 1368 bps corresponding to a polypeptide of 456 amino acid residues in which is contained the conserved region specific to GHF9 that has the essential amino acid residues for enzyme activity. In multiple alignments and phylogenetic analysis, the deduced amino acid sequence of Ean‐ EG showed the highest sequence similarity (about 79%) to that of an annelid (Pheretima hilgendorfi) and could be clustered together with other GHF9 cellulases, indicating that Ean‐EG could be categorized as a member of the GHF9 to which most animal cellulases belong. The histological expression pattern of Ean‐EG mRNA using in situ hybridization revealed that the most distinct expression was observed in epithelial cells with positive hybridization signal in epidermis, chloragogen tissue cells, coelomic cell‐aggregate, and even blood vessel, which could strongly support the fact that at least in the earthworm, Eisenia andrei, cellulase function must not be limited to digestive process but be possibly extended to the innate immunity. HighlightsA new endogenous earthworm cellulase, Ean‐EG, and its expression pattern are demonstrated.Deduced amino acid sequence comprises the conserved region specific to GHF9 containing the essential amino acid residues for enzyme activity.Ean‐EG expression was observed in epidermis, chloragogue tissue cells, coelomic cell‐aggregate, and even blood vessel.Cellulase function could not be limited to digestive process but be possibly extended to the innate immunity.