Biomedical subjects

Hideo Nakajima

Publications and source records attributed to Hideo Nakajima.

16 recordsLinked to original sources

PubMed2005

Is the platysma flap musculocutaneous? Angiographic study of the platysma.

BACKGROUND: The platysma flap has often been used for reconstructions of the head and neck, but the arterial anatomy of the platysma itself has not been clarified. METHODS: The anterolateral neck skin in five sides of four fresh cadavers that had been injected systemically with a lead oxide-gelatin mixture was elevated and divided into three layers: the skin with adipofascial tissue over the platysma, the platysma, and the adipofascial tissue under the platysma. Radiographs were taken of each specimen using the soft x-ray system. RESULTS: The anterolateral neck skin was chiefly supplied by branches of the submental, facial, superior thyroid, transverse cervical, and occipital arteries, and it was found that the vasculature of the arterial branches can be classified into three groups. In all of the groups, the arterial branches penetrated the platysma and did not run long in the platysma layer. The platysma was supplied by only small vessels from the arterial branches. Furthermore, there was little connection between the vascular plexus of the platysma and that of the skin layer with adipofascial tissue above the platysma and the platysma located in the subcutaneous tissue. CONCLUSIONS: The platysma flap should be considered fasciocutaneous rather than musculocutaneous. Therefore, the platysma flap should usually be elevated with the deep adipofascial tissue under the platysma. Flap survival is threatened if it is elevated without the adipofascial tissue under the muscle as with a usual musculocutaneous flap.

Humans↗

PubMed2005

The fetal dermal but not loose fascial mesenchymal cells possess regenerative activity of dermal structure.

Fetal skin possesses a regenerative activity until certain developmental stages. However, the origin of cells that regenerate dermis after wounding has not been clarified yet. In the present study we located the origin of cells that reconstruct fetal dermal structure by histological examination and by marking cells in the loose fascia. Next we evaluated the regenerative activity of fetal dermal mesenchymal cells by cotransplanting with fetal epidermal cells onto the skin defect of scid mice. We conclude that fetal dermal mesenchymal cells but not loose fascial cells possess regenerative activity even on the environment in scid mice.

Animals↗

PubMed2005

[Molecular events associated with Barrett's oesophagus].

The development and progression of Barrett's epithelium are accompanied with the acquisition of many molecular changes of the oesophageal mucosa. Gastro-oesophageal reflux and inflammation cause the oxidative stress and free-radical generations, which result in the expression of oxidative-stress-related genes and the induction of DNA damage. The development of Barrett's epithelium follows a metaplasia-dysplasia-adenocarcinoma sequence, characterized by the accumulation of many genetic and epigenetic alterations, which are seen in carcinogenesis. Abnormalities in the expression of tumor suppressor genes, such as p53, p16, APC, and a number of molecules involved in cell proliferation, apoptosis or angiogenesis are observed. These genetic alterations affecting the cancer hallmarks provide a better understanding of the etiology and pathogenesis of the disease.

Adenocarcinoma↗

PubMed2004

Water-swellable polyelectrolyte microgels polymerized in an inverse microemulsion using a nonionic surfactant.

A series of poly(dimethylacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid) microgels slightly crosslinked by methylene-bis-acrylamide (MBA) were polymerized in a novel inverse microemulsion polymerization (IMEP) system. To determine a suitable composition of the IMEP system, the phase diagram of a pseudoternary system was made. The pseudoternary polymerization system consisted of n-hexane, a nonionic surfactant (polyoxyethylene oleyl ether, C18En), and an aqueous monomer solution. Polymerization was performed in a single-phase reversed micelle solution. The reversed micelles were about 50 nm in diameter, as determined by FF-TEM. The viscometric characteristics of the polymers extracted from the IMEP system were studied in 3 mM sodium chloride aqueous solution. The intrinsic viscosity values for the noncrosslinked and crosslinked (0.1 mol% MBA was incorporated) samples were 25 and 7.4 dl/g, respectively. The overlap concentration (c*) of crosslinked polymer microgel occurred at c[eta] = 1 in the solvent. When the volume fraction (phi) of the microgel was 0.7, the value of the apparent yield stress of the microgel solution was observed. These results show that the microgel has a significant thickening effect above c* due to friction between the microgel particles. It is assumed that the microgels polymerized in a confined space retain the shape or size of the nanosized reactor with a diameter on the order of 50 nm.

Cross-Linking Reagents↗

PubMed2004

Arterial anatomy of the lower lip.

The arterial anatomy of the lower lip was investigated in 12 sides of six fresh cadavers that had been injected systemically with a lead oxide and gelatin mixture. We found that the blood supply of the lower lip was derived from the facial artery and three dominant labial arteries: the inferior labial artery, the horizontal labiomental artery, and the vertical labiomental artery. The inferior labial artery was derived from the facial artery or superior labial artery, and ran through the submucous tissue horizontally. The horizontal labiomental artery arising from the facial artery was located between the depressor labii inferioris muscle and orbicularis oris muscle. The vertical labiomental artery arose from the submental artery. These three arteries provided small vessels that traversed vertically. These small vessels and the small branches of the facial artery, that run superficial and deep to the orbicularis oris muscle, formed a vascular network in subcutaneous and submucous tissues and minute vessels branched off to the skin, mucosa, and muscles.

Angiography↗

PubMed2004

Anatomical study of subcutaneous adipofascial tissue: a concept of the protective adipofascial system (PAFS) and lubricant adipofascial system (LAFS).

The subcutaneous adipofascial tissue over the entire body was radiographically and macroscopically investigated in 20 fresh and embalmed cadavers. The subcutaneous adipofascial tissue was made up of two adipofascial layers. Because the superficial layer forms a solid structure and is thought to protect against external forces, the adipofascial system formed by the solid structure was named the "protective adipofascial system (PAFS)". Because the deep layer forms a mobile layer and is thought to lubricate musculoskeletal movement, the adipofascial system formed by the mobile structure was named "lubricant adipofascial system (LAFS)". By classifying subcutaneous adipofascial tissue by its functional characteristics, we found we could understand the subcutaneous adipofascial structure over the entire body well.

Adipose Tissue↗

PubMed2004

Comparison of three different supercharging procedures in a rat skin flap model.

A significant clinical problem in reconstructive surgery is partial loss of a pedicled flap. To resolve this problem, various methods of vascular augmentation have been developed; "supercharging" is one of those techniques. A new rat flap model was developed for investigation of the supercharging procedure, and the efficacy of the arterial supercharging method was examined. The purpose of this study was to investigate how an arterial supercharging procedure could generate large flap survival areas with different supercharging positions in rats. On the basis of the vascular anatomical features of rats, a circumferential skin flap from the lower abdomen to the back, measuring 4 x 12 cm, was marked. The flap was divided along the dorsal midline. Forty rats were divided into four experimental groups, as follows: group 1 (control), flaps based only on the deep circumflex iliac artery and vein; group 2, flaps supercharged with the ipsilateral superficial inferior epigastric artery; group 3, flaps supercharged with the contralateral superficial inferior epigastric artery; group 4, flaps supercharged with the contralateral deep circumflex iliac artery. On the fourth postoperative day, the flaps were evaluated with measurements of necrosis and survival areas. Microfil (Flow Tech, Inc., Carver, Mass.) was then injected manually throughout the body, and the vascular changes produced by supercharging were angiographically evaluated. Compared with group 1 (control), the flap survival areas were significantly greater in distally supercharged flaps in groups 3 and 4 (mean flap survival, 91.2 +/- 5.2 percent and 90.5 +/- 10.6 percent, respectively; p < 0.001) and in proximally supercharged flaps in group 2 (45.9 +/- 4.1 percent, p < 0.05). Angiographic assessment of the flaps that survived completely revealed marked dilation of the choke veins among the territories and reorientation of dilated veins along the axes of the flaps. This study suggests that distal arterial supercharging (contralateral superficial inferior epigastric artery or contralateral deep circumflex iliac artery) is more effective than proximal arterial supercharging (ipsilateral superficial inferior epigastric artery) in increasing flap survival. Although the rat skin flap may not be analogous to human flaps, distal arterial supercharging might have useful therapeutic potential in increasing flap survival in clinical practice.

Angiography↗

PubMed2004

Arterial anatomical features of the upper palpebra.

The arterial anatomical features of the upper palpebra were examined in both sides of seven fresh cadavers that had been systemically injected with a lead oxide/gelatin mixture. All specimens were stereoscopically radiographed for analysis of the three-dimensional structure of the arteries and were macroscopically dissected for observation of the relationships between the arteries and the other tissues. Cross-sections were prepared from one specimen and examined histologically. In all cases, there were four arterial arcades in the upper palpebra, namely, the marginal, peripheral, superficial orbital, and deep orbital arcades. Each arcade provided small vertical branches. The vertical branches coursed on both sides of the orbicularis oculi muscle and on both sides of the tarsal plate. From these small vertical branches, fine vessels branched off to the skin, muscle, and tarsal plate. These findings are important for avoiding complications such as bleeding and are useful for designing local flaps, such as switch flaps, for reconstructive surgical procedures.

Angiography↗

PubMed2004

Vascular anatomy of the anterolateral thigh flap.

Arterial and venous anatomy and their relation to the anterolateral thigh flap were examined in 10 specimens of six fresh cadavers in which radiopaque materials were injected into both the arterial and venous systems. Territories and positions of individual perforating arteries were measured, and the venous drainage pathway of the flap was analyzed. All specimens were radiographed stereoscopically to observe the three-dimensional structure of the arteries and veins. The territory of each perforating artery was smaller than expected. Most of the venous blood that had perfused the dermis was considered to pool in a polygonal venous network located in the skin layer and to enter the descending branch of the lateral circumflex femoral artery through large descending veins. The venous territories were considered different from the arterial territories. The findings in this study suggest that the design of the anterolateral thigh flap should be based on the venous architecture rather than on the arterial architecture and that the flap survival rate might be improved if thinning is performed appropriately.

Angiography↗

PubMed2003

Transcriptional regulation of ILT family receptors.

Ig-like transcripts (ILT/leukocyte Ig-like receptor/monocyte/macrophage Ig-like receptor or CD85) are encoded on human chromosome 19q13.4, designated the human leukocyte receptor complex, and are predominantly expressed on myeloid lineage cells. We investigated the transcriptional regulation of ILT1, ILT2, and ILT4 genes to elucidate control mechanisms operating on the specific expression of ILT receptors. Inhibitory ILT2 and ILT4 both have a similar genomic structure, in which the approximately 160-bp 5'-flanking regions function as core promoters with critically important PU.1 binding sites. However, an Sp1 family-binding GC-box is more influential in trans-activation of ILT2 than ILT4. Additionally, ILT4 transcription is tightly regulated by chromatin modifications accompanied by histone acetylation, which strictly controls expression within myeloid lineage cells. Activating ILT1 carries a core promoter corresponding to the intronic region of ILT2 and ILT4, where PU.1 and Runx1 binding sites are essential, but a downstream heat shock element also augments promoter activity. Thus, each ILT is regulated by a distinct transcriptional mechanism, although PU.1 acts as a common trans-acting factor. We also found that human CMV infection strongly trans-activates inhibitory ILT2 and ILT4 genes through the expression of immediate-early proteins.

Antigens, CD↗

PubMed2003

Expression of bone morphogenetic proteins during mandibular distraction osteogenesis in rabbits.

PURPOSE: We examined the expression pattern of bone morphogenetic proteins (BMPs) during mandibular distraction osteogenesis in rabbits and also investigated the mechanism of membranous bone distraction. MATERIALS AND METHODS: Twenty-three rabbits underwent mandibular distraction (protocol; no latency period, a 1-week distraction at 0.5 mm/d, and a 2-week consolidation period). Samples were collected at 3, 5, and 7 days of distraction and at 1-week and 2-week consolidation. We prepared undecalcified fresh-frozen sections and immunohistochemically evaluated the expression of BMPs 2 through 8. RESULTS: Both endochondral ossification and intramembranous ossification were observed. The expression of BMPs 2, 4, 5, and 6 was observed continuously from the beginning of distraction. BMP-7 was expressed weakly. The expression of BMP-3 was not observed conspicuously during distraction but was strongly expressed at 1- and 2-week consolidation. CONCLUSION: The expression pattern of BMPs during membranous bone distraction was similar to that during long bone distraction, but it differed from the expression pattern of long bone distraction in that the expression of BMPs was maintained for 2 weeks after the completion of distraction.

Animals↗

PubMed2003

Dramatic increase of telomerase activity during dendritic cell differentiation and maturation.

Telomerase, the reverse transcriptase that maintains telomere DNA, is usually undetectable in most adult tissues but is positive in embryonic tissues and in cancers. In addition, freshly islolated or in vitro-activated lymphocytes were shown to express high levels of telomerase activity, although its expression in myeloid cells including dendritic cells (DCs) is largely unknown. Here, we investigated telomerase activity during the differentiation and maturation process of DCs. In vitro culture of bone marrow (BM) cells with granulocyte macrophage-colony stimulating factor and interleukin-4 induced a dramatic increase of telomerase activity accompanied with their differentiation into DCs. Furthermore, stimulation with microbial components such as lipopolysaccharide (LPS), which triggers maturation of DCs, augmented the activity. In vivo responses of telomerase activity were also observed in splenic DCs by injection of LPS intraperitoneally. It is interesting that in old mice, telomerase activity of splenic DCs was significantly higher than young mice but rather decreased after LPS stimulation. By measuring expression of cell-surface activation markers, splenic DCs of old mice responded poorly to LPS stimulation. Such poor responses to LPS were also observed in BM-derived DCs. These different features of DCs between young and old mice may contribute to a pathogenesis to microbial infections.

Animals↗

PubMed2003

Transplanted endothelial progenitor cells augment the survival areas of rat dorsal flaps.

Endothelial progenitor cells (EPCs) have been identified in peripheral blood, and have been reported to be incorporated into ischemic regions such as the ischemic hindlimb. In this study, we examined whether or not transplantation of EPCs is useful for salvaging surgical flaps in vivo. At the same time, we quantitatively compared the neovascularization ability of transplanted EPCs and that of mature endothelial cells (ECs). ECs obtained from the aorta of rats by explantation and passaged several times were used in the present study. EPCs were obtained from the blood of rat hearts. The blood samples were separated by density gradient centrifugation. Light-density mononuclear cells (MNCs) were collected and cultured on plastic plates coated with rat plasma vitronectin. Cells attached at day 7 of culture were deemed to be EPCs. Then PBS (control), ECs, or EPCs (3.0 x 10(5) suspended in 1.0 ml PBS) were injected at the middle of a flap. Seven days after surgery, the survival lengths of the flaps were evaluated. EPC-transplanted groups revealed statistically significant augmentation of survival length compared with the other two groups (p < 0.003). EPC-transplanted groups had significantly more angiographically detectable blood vessels (p < 0.003) and significantly higher capillary density (p < 0.03) than the other two groups. Confocal microscopy revealed that EPCs were incorporated into enhanced neovascularization. These results suggest that transplantation of EPCs may be useful for salvaging surgical flaps, and EPCs are superior to ECs in neovascularization ability.

Animals↗

PubMed2002

Facial artery in the upper lip and nose: anatomy and a clinical application.

Twenty-five facial arteries were examined radiographically in 19 fresh cadavers that had been injected systemically with a lead oxide-gelatin mixture. Major branches of the facial artery in the upper lip and nose were investigated, and the anatomical variations were classified into three types on the basis of the anatomy of the lateral nasal artery, which was determined as an artery running toward the alar base. In 22 cases (88 percent), the facial artery bifurcated into the lateral nasal artery and superior labial artery at the angle of the mouth. In two cases (8 percent), the facial artery became an angular artery after branching off into the superior labial artery and the lateral nasal artery sequentially. In one case (4 percent), the facial artery became an angular artery after branching off into the superior labial artery, and the lateral nasal artery then branched off from the superior labial artery. Branches from the lateral nasal and superior labial arteries were observed stereographically. Vascular anastomoses between those branches were created in the upper lip, columella base, and nasal tip, and an intimate vascular network was formed. With a vascular network in the mucosa of the upper lip, a bilobed upper-lip flap was created for a clinical case with a full-thickness defect of the ala.

Arteries↗

PubMed2002

Venous drainage architecture of the temporal and parietal regions: anatomy of the superficial temporal artery and vein.

Anatomy of the superficial temporal artery and vein was analyzed with arteriograms, venograms, and arteriovenograms of fresh cadavers that had been injected with contrast medium. The superficial temporal artery always divided into two major branches: the frontal and parietal branches. However, the superficial temporal vein divided into one, two, or three major branches. The distribution area of the major branches of the superficial temporal vein was larger than that of major branches of the superficial temporal artery, and arteriovenograms clearly demonstrated that, except for its proximal portion, the superficial temporal vein was independent of the superficial temporal artery. The frontal and parietal branches of the superficial temporal artery had thin venae comitantes that originated from the proximal portion of the superficial temporal vein, and the venae comitantes gave off branches toward the skin and the underlying soft tissue. Branches to the skin anastomosed with a superficial venous network in the skin layer, which was formed by ramifications of the superficial temporal vein. The venous architecture of the temporal and parietal regions consisted of cutaneous veins and venae comitantes and was basically similar to that of the forearm and scapular region.

Humans↗

PubMedDate not supplied

Mutual dependence of murine fetal cutaneous regeneration and peripheral nerve regeneration.

Mammalian fetal cutaneous wounds made at certain developmental stages show complete regeneration. It is reported that wound healing in both adult and fetal skin is disrupted by denervation. Furthermore, fetal cutaneous regeneration has unique aspects such as epidermal wrinkle texture regeneration and dermal regeneration that depend on developmental stage. Therefore, we have examined the relationship of fetal cutaneous regeneration with denervation. We made cutaneous wounds on fetal mice at various developmental time points including embryonic days (E)13, E15, and E17, and compared the regenerating patterns of peripheral nerves in the skin. We found that when the fetuses are wounded at an early stage of development, peripheral nerves regenerate quicker than at later stages of development when peripheral nerve regeneration is delayed. Next, we denervated the intercostal nerves and made wounds at the denervated sites on E13 and E15. We found that epidermal wrinkling and dermal regeneration were disrupted by denervation. These findings indicate that components of fetal cutaneous regeneration and peripheral nerve regeneration are mutually dependent.

Animals↗