Biomedical subjects

F Suwa

Publications and source records attributed to F Suwa.

At least 19 recordsLinked to original sources

PubMed2002

Facial subdermal vascular network flap: anatomic study and clinical application.

Despite the numerous flaps for facial reconstruction that have been described, the search for the ideal flap with good color matching and minimal donor-site morbidity continues. In the past 3 years we have repaired 13 facial defects with success using the lateral genicervical flap - a type of facial subdermal vascular network flap (SVNF) - with a pedicle located on the preauricular region. An anatomic study of the facial SVNF, including blood supply and vascular distribution of the face and anatomic characteristics of facial vessels, based on 14 cadaver dissections, was carried out. The blood supply of the facial skin basically originated from the branches of the facial, superficial temporal and infraorbital arteries. The lateral genicervical skin was supplied basically by the branches of the facial, superficial temporal and occipital arteries, but also by the terminal branches of the superior thyroid artery. The branches diverging from these arteries became superficial and formed a subcutaneous arterial network. The arterioles from the network went to the corium layer and formed a subdermal arterial network whose arterioles anastomosed with each other in a honeycomb-like structure. The vascular distribution presented certain directivity on different areas. The blood supply of the pedicle originated from the subdermal vascular network formed by the perforator branches of these arteries. The arterioles from the facial and superficial temporal arteries anastomosed in the lateral genicervical region. From the anatomic study, we think that the viability of the facial SVNF depends basically on the subdermal vascular network formed by the perforator branches of the pedicle, and that the anastomoses between the facial and superficial temporal arteries provide a solid anatomic basis to the lateral genicervical flap. The clinical data also indicated that this flap is a useful alternative for facial, especially superficial temporal, defects. But the directivity must be taken into account in its clinical application.

Adolescent↗

PubMed2001

The laminar structure of the common opossum masseter (Didelphis marsupialis).

Using three heads of the common opossum (Didelphis marsupialis), which may be considered to have a primitive mammalian form and therefore be appropriate for this study, the laminar structure of the masseter was investigated. We also attempted a comparative anatomical study of the relationships of food habits to the laminar structures of the masseter, zygomatic arch and mandibular ramus. In the common opossum masseter, a total of six layers, the primary and secondary sublayers of the superficial layer, the intermediate layer, and the primary, secondary and third sublayers of the deep layer as a proper masseter, were observed. These layers showed a typical reverse laminar structure, with the layers of tendons and muscles alternating. The maxillomandibularis and zygomaticomandibularis muscles were observed in one layer each, as an improper masseter. The laminar structure of the common opossum masseter was shown to be more similar to that of carnivorous placental animals than that of the herbivorous red kangaroo, a similar marsupial. In regard to the number of layers in the laminar structure of the masseter, the results of both this study and those of our predecessors' showed that differences in food habits affect the deep layer in the proper masseter of marsupials and placental mammals, and that of the maxillomandibularis muscle of placental mammals in the improper masseter.

Adaptation, Physiological↗

PubMed2001

Alteration of apoptosis in cleft palate formation and ectomesenchymal stem cells influenced by retinoic acid.

It has been shown that apoptosis is involved in normal embryonic development. The aim of the present study was to elucidate the role and alteration of apoptosis in the pathogenesis of cleft palate induced by retinoic acid (RA) and the ectomesenchymal stem (EMS) cells influenced by RA. RA was administered by gavage to pregnant C57BL/6N strain mice in the experimental group, and the control group received oil alone. Pregnant mice were killed at set periods of time thereafter and histologically analyzed. EMS cells explanted from the palatal shelves of embryonic mice were cultured and characterized by immunohistochemistry, growth curves and population-doubling time. The alterations of apoptosis of EMS cells and developing palatal shelves influenced by RA were evaluated by the terminal deoxynucleotidyl transferase-mediated UTP-biotin nick end-labeling (TUNEL) method. RA-treated mice showed formation of cleft palates resulted from the small size of the palatal shelves and their failure to lift. TUNEL staining showed that the number of apoptotic mesenchymal cells in palatal shelves in the RA-treated mice was increased significantly when compared with the control group. The primary culture of EMS cells proceeded successfully. The population-doubling time of RA-treated cells was much longer compared with non-treated EMS cells. RA also dramatically increased the number of apoptotic cells in EMS cells in vitro. We concluded that EMS cells are the crucial cells in palate development. RA could inhibit the proliferation and induced the apoptosis of EMS cells. The inhibition of growth and excess apoptosis of EMS cells may contribute to the formation of cleft palate and other orofacial congenital malformations.

Animals↗

PubMed2001

Transcriptional mRNA of bone morphogenetic proteins 2, 3, 4, and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors.

Bone morphogenetic proteins (BMPs) have been shown to play an important role in cell growth and differentiation. BMPs, a rapidly expanding family closely related to transforming growth factor-beta (TGF-beta) superfamily, have been proven recently to possess a regulatory role and neurotrophic capacity in neurogenesis. The aim of the present study is to reveal the relationship among BMPs, peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP 2, 3, 4 and 5 in 12 cases of schwannoma, four cases of malignant schwannoma and three cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of schwann cell from the peripheral neuroectomy of trigeminal neuralgia were positively expressing mRNA of BMP-2, 3, 4 and 5. However, the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. Except for the BMP-4 mRNA, the expression signals of BMP-2, 3 and 5 mRNA in malignant schwannoma were relatively lower than in benign lesions. On the basis of the findings, we concluded that selected members of BMPs existed in the peripheral nerves and might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Moreover, the effects of BMP-2, 3, 4 and 5 on peripheral nerve system and its neoplastic transformation might be widespread, diverse and antagonistic.

Adult↗

PubMed1998

SEM study on microvascular changes following implantation of bone morphogenetic protein combined with hydroxyapatite into experimental bone defects.

BMP-HAP complex was implanted into a bone defect in the femur of Wistar-strain rats, and animals were allowed to heal for one to 8 weeks prior to sacrifice. Similar bone defects without BMP-HAP complex served as controls. Osseous healing and microvascular changes, as revealed by plastic microcorrosion castings, were subsequently examined under a scanning electron microscope. One week after implantation, sproutings and congregate sinusoidal capillary plexuses and primary bone trabeculae (woven bone) were observed around and between the BMP-HAP complexes. Control specimens revealed a fine and immature sinusoidal capillary plexus arising from sproutings and elongations of pre-existing blood vessels, but bone formation was not observed. At two weeks, newly-formed trabeculae were observed around and on the surface of the HAPs, and a network of thick, newly-formed vessels was observed in intervening space. At three weeks, networks of newly-formed vessels were observed on the surface of the HAPs, and surrounding newly-formed trabeculae had become thickened. At four weeks, bone defects were filled, and HAP was completely embedded in new bone. At eight weeks, the HAP was fused with new bone, and the boundary between the HAP and new bone was unclear. In comparison with comparable surgically created control bone defects without implanted BMP-HAP complex, BMP apparently stimulates new vascularization. Further, implanted BMP-HAP apparently stimulates undifferentiated mesenchymal cells to differentiate into angioblasts and osteoblasts, or vice versa (dedifferentiation).

Animals↗

PubMed1996

Experimental ligation versus embolization of the external carotid artery: a comparative hemodynamics study.

Patterns of collateral vascularization were investigated by SEM evaluation of microvascular corrosion casts following either ligation or embolization of the external carotid artery in the rabbit. Results indicated that rich collateral channels were established soon after ligation of this artery, and blood supply to the lesional area was never cut off. In contrast, embolization effectively obstructed blood supply by reducing collateral branches. We concluded that for purposes of controlling blood loss, it is more helpful to employ external carotid embolization rather than ligation for oral maxillofacial lesions with a rich blood supply.

Animals↗

PubMed1995

Induction of reparative dentin formation in dogs by bovine bone morphogenetic protein bound to ceramic dentin.

Bone morphogenetic protein (BMP) refers to a group of bone-inducing growth factors used to enhance experimental osseous repair. Previous studies have indicated that BMP promotes the proliferation and differentiation of fibroblasts from human dental pulp both in vitro and in vivo. Furthermore, when BMP is used as a pulp capping agent, it has ability to induce the formation of both osteodentin and tubular dentin. In this study, we sought to explore whether or not BMP, complexed to ceramic dentin (BMP/CD), would constitute a more effective pulp capping agent than BMP alone. Experimental pulp exposures were created in dogs, and BMP/CD was placed on the surface of the exposed dental pulp. The inductive effect of such stimulation on reparative dentin formation was observed morphologically. Results showed that two weeks after exposure, some osteodentinal matrix was formed in the space surrounding the implanted BMP/CD particles while the remainder of the space was occupied by proliferating fibroblasts. At 4 weeks postoperatively, the dential bridge was complete. When ceramic dentin without BMP was used, there was minimal bone-like matrix formed even at 4 weeks postoperatively. These results suggest that the BMP/CD complex is effective as a stimulant of reparative dentin formation and shows potential as a therapeutically useful pulp-capping agent in a clinical setting.

Animals↗

PubMed1994

Changes in histological structure and microvasculature of the rat tongue after transection of the hypoglossal nerve.

This investigation was made on sequential changes in the tongue caused by unilateral transection of the hypoglossal nerve in the rat. These changes were examined on the basis of gross inspection of the lingual dorsal surface, histological aspects of the intrinsic muscle and interstitial tissues, morphological changes in the capillary loops of the filiform papillae utilizing plastic microcorrosion casts, and blood flux and number of erythrocytes in the lingual dorsum as determined by laser Doppler flowmetry. The period of examination following denervation of the hypoglossal nerve was divided into 3-5 days, 1, 2-3, 4-5, 6-7 and 66 weeks. The initial sign of histological change was an edematous change that later developed to atrophic change of the muscular element. This pathological change caused a change in volume on the lesion side of the tongue and finally formed a depression on the dorsal surface and a scallop-like lateral margin. Four to five weeks after denervation, the lesion half swelled, and its lingual apex elongated forward with a coving of the lingual median groove. The filiform papillae showed decreased keratinization, and interpapillary intervals were somewhat widened. Capillary loops in the papillae began to change, showing slight twistings at the tips of loops. Additionally, bulging, coiling and tortuosity were observed on both crura. The loops showed more complicated transformation, and little recovery was observed even 66 weeks after denervation. Blood flux in the dorsal mucosa decreased very slowly after a slight increase. This process seemed to be in proportion to the transformational complexity of the capillary loops in the filiform papillae. In conclusion, unilateral transection of the hypoglossal nerve, which is composed almost entirely of efferent neurons, caused edema and atrophic change in the intrinsic lingual muscle fibers with interstitial fibrosis in the lesion half of the tongue. Capillary loops in the filiform papillae were transformed markedly and successively by transection of the hypoglossal vasomotor neuron together with a slight decrease in blood flow in the dorsal mucosa. None of these changes recovered even at 66 weeks after transection.

Animals↗

PubMed1994

[The evaluation of the anti-shivering effect of tramadol during epidural anesthesia].

60 patients (except parturients) suffering from shivering after receiving epidural anesthesia were randomly divided into 2 equal groups. In order to evaluate the effect of Tramadol on the shivering, i.v. Tramadol (1 mg/Kg), in contrast to distilled water (20 ml) for the control group, was administered to the patients in the experimental group. We compared the arrest time between the two groups in addition to systolic blood pressure, diastolic blood pressure, heart rate, arterial O2 saturation, respiratory rate and body surface temperature. Furthermore, the degree of shivering was also compared sequentially. The systolic pressure of the control group declined significantly in the first 30 minutes (P < 0.05). The other data, including the diastolic pressure, heart rate, arterial O2 saturation, respiratory rate and body surface temperature, showed no significant difference (P > 0.05). The arrest time in the experimental group was 179 +/- 71.25 seconds in contrast to 2790 +/- 440.23 seconds in the control group, a large significant difference (P < 0.001). 10% of the patients in the experimental group experienced nausea or vomiting and 6.67% of the patients showed sedation which did not disturb consciousness level of psychomotor status. Since the exact mechanism of shivering during epidural anesthesia is not established, we sincerely hope more information about the effect to Tramadol on shivering can be uncovered.

Adult↗

PubMed1993

Development and histology of fibrous architecture of the fetal temporomandibular joint.

The developmental history of the temporomandibular joint (TMJ) was investigated in 10 fetuses of 4 to 10 months of gestational age. The S-type structure of the disc is formed by the following bases: 1) the flat upper and concave lower surfaces of the disc; 2) thinner intermediate zone and thicker anterior and posterior bands; 3) the projection of the articular tuberculum and superoposterior growth of the condyle. The posterolateral part of the disc was the thickest and the corresponding part of the fossa was the deepest. The condyle was originally positioned beneath the part of disc that was considered the main force-bearing area. The distribution and arrangement of elastic and collagen fibers in the disc was proportional to disc function. Gross elastic fibers in the posterolateral part of the posterior band were connected with the upper head of the pterygoideus lateralis muscle fibers running medioanteriorly. They were indicated to be antagonistic with each other. At 4 months of gestational age, a few elastic fibers appeared in the bilaminar region and began to form bundles as the fetus grew. At full-term dense elastic fibers were found in the upper stratum of the bilaminar region.

Gestational Age↗

PubMed1993

Ability of hydroxyapatite-bone morphogenetic (corrected from morphologenetic) protein (BMP) complex to induce dentin formation in dogs.

This histological investigation examined the formation and differentiation of pulp cells under the influence of HAP/BMP complex. HAP/BMP complex was implanted in exposed pulp of the mandibular premolars and alveolar bone defect in the dog. Sequential changes in these areas were examined mainly under a light microscope and partly under a scanning electron microscope. Two weeks after the operation, fibroblast-like cells proliferated right beneath the implanted complex, and after 3 weeks, dentin including dentin tubules grew in the pulp. After four weeks a dentin bridge composed of osteoid dentin was found, and after 8 weeks this dentin calcified and covered the defective surface of the root and adhered to new bone surrounding the HAP granules. The results indicated that the dentin induced by HAP/BMP complex may be of two types: tubular dentin and osteodentin. This complex exhibited outstanding ability to induce dentinogenesis and osteogenesis.

Animals↗

PubMed1992

Development of collagen fibers and vasculature of the fetal TMJ.

Using 12 human fetuses, histological development and changes in connective fiber structure and fine vascular patterns have been investigated in various fetal gestational stages by light and scanning electron microscopy. The main arterial supply of the articular disc was from the bilaminar region and pterygoideus lateralis muscle. The vascular network on the disc surface was related with fluid secretion. When the bilaminar region was compressed, it caused ischemia and fibrosis as the main pathological changes in TMJ derangement. A decrease in fluid from blood vessels might occur in TMJ degeneration. Collagen fibers in the disc passed mainly anteroposteriorly. In the anterior and posterior bands, muscular tendon fibers came from the pterygoideus lateralis muscle and superior stratum of the bilaminar region. In the posterior band three-dimensional structures of collagen fibers suitable for load bearing were observed. The compass network and process on the disc showed the normal structure that is formed gradually and has functions including dispersion, pressure bearing, friction-proofing and storage of the synovial fluid. Attachments of the disc were suitable for disc function. Large elastic fibers in the posterolateral part of the superior stratum of the bilaminar region may be antagonistic to the upper head of the pterygoideus lateralis muscle fibers passing medioanteriorly, indicating that this antagonism is available for disc function.

Collagen↗

PubMed1991

On the facial artery of the raccoon dog (Nyctereutes procyonoides viverrinus Temminck).

Detailed observations were made of the facial artery in 20 raccoon dogs (Nyctereutes procyonoides viverrinus Temminck) utilizing the plastic injection method. The findings obtained were discussed in comparison with the facial artery of carnivorae. The facial artery diverged anterolaterally from the external carotid artery independently at a position between the origins of the lingual and the posterior auricular arteries when the external carotid bent laterally in front of the tympanic bulla. This artery, immediately after giving off the styloglossal branch, passed forwards superomedial to the digastricus muscle and medial to the insertion of the pterygoideus medialis muscle up to the posterolateral end of the mylohyoideus muscle, where the submental artery was derived. The submental ran forwards, giving off the digastric, the mylohyoid, the sublingual and the cutaneous branches, down to the posterolateral end of the intermandibular symphysis, where it anastomosed with the opposite fellow. The facial artery bent inferolaterally and passed laterally giving off the pterygoid and the inferior masseteric branches, and then emerged out onto the face through the facial vascular notch located inferoanterior to the angular process, which was extremely well developed in this species. The main stream of the artery ran anterosuperiorly at about 40 degrees to the horizontal plane along the anterior margin of the masseter muscle, since the notch was located on a projected level posterior to the middle of the zygomatic arch, giving rise en route to the anterior masseteric, the mandibular marginal, the buccal and the cutaneous branches. The artery finally divided into the inferior and superior labial arteries at the inferior margin of the mandibular origin of the buccalis muscle in the angle of the mouth. The facial artery of the raccoon dog was thus similar in its origin to that in the dog, cat and lion, but notably different in the short course of its submandibular region, and the nearly horizontal passage of the main route in the face, without the mandibular glandular branch. Additionally an extremely well developed angular process, a submandibular lobe and fairly posterior position of the vascular notch were found.

Animals↗

PubMed1991

On the laminar formation of the masseter muscle in the lion (Panthera leo).

An investigation was made of the laminar structure of the masseter muscle in 3 lions (Panthera leo s. Felis leo), and the findings obtained were evaluated in comparison with those in some other carnivora. Although the general aspect of the masseter of the lion resembled that of the cat, there was no close similarity or analogy between them. The construction of the masseter in the lion was as follows. The superficial layer consisted of primary and secondary sublayers, the intermediate layer was composed of anterior and posterior portions, and the deep layer also had anterior and posterior portions. Among these three layers (the masseter proper muscle), the superficial layer was extremely well developed as a characteristic feature of this species. The maxillomandibularis muscle was developed in a muscular element of its origin and had its tendinous insertion on the anteroinferior margin of the masseteric fossa. The zygomaticomandibularis muscle was also fairly well developed in the form of two muscular bundles which originated from the temporal crest, a shelf forming a lateral protrusion on the basis of the zygomatic process, and its posterior surface. Both muscles were also well developed as the masseter improper. Such a huge and complicated laminar pattern of the masseter muscle in the lion should be sufficient to exert a strong force as a predatory animal.

Animals↗

PubMed1990

Plastic injection method for preparing microvascular corrosion casts for SEM and its practical application.

This paper examines the application of the acryl plastic injection to the preparation of vascular corrosion microcasts for scanning electron microscopy (SEM). The original injection method using acryl plastic was described by Taniguchi, Ohta et al. in 1952 and 1955, under the title of "New improved method for injection of acrylic resin". Three dimensional observations were undertaken in our laboratory on the angiology at the macro- and microscopic levels of various organs from various mammals employing the original method. Based on this extensive experience, an injection method for preparing corrosion microcasts for use in SEM was devised in our laboratory. Microcasts prepared by the present method were able to demonstrate the fine vascular architecture of each organ. In general, although applications for preparing vascular microcasts of isolated and parenchymal organs are not so difficult, the method can be used to be applicable for demonstrating the fine vascular architecture related to or within hard tissues, as well as for investigating the morphological relations between changes of vascular patterns and restorative changes in the surrounding tissues affected by experimental operations. SEM microphotographs are also presented to illustrate actual practical applications.

Animals↗

PubMed1990

On the arteria maxillaris which passes medial to the pterygoideus lateralis muscle of the Japanese--patterns of origin of the inferior alveolar, the masseteric and the posterior temporal arteries.

Variations in the patterns of origin of the inferior alveolar, the posterior deep temporal and the masseteric arteries when the maxillary artery passed medial to the pterygoideus lateralis muscle on 30 sides of 24 heads (10.8%) among a total of 278 sides of 139 heads of the Japanese, were investigated. The results obtained may be summarized as follows: 1. The maxillary artery gave off a common trunk between the inferior alveolar and the posterior deep temporal (76.7%), the latter distal to the former (16.7%) and in contact with their origins (6.7%). The masseteric artery always arose from the posterior deep temporal in 24 heads. 2. The above-mentioned common trunk was observed in 52.1% of males and 47.9% of females, as well as on 56.5% of left sides and 43.5% of right sides. 3. It can be said that the maxillary artery always passed medial to the pterygoideus lateralis, when the inferior alveolar arose in common with the posterior deep temporal.

Adult↗

PubMed1989

[The submental artery of the cat].

This study was made on the origin, ramifications and distribution features of the submental artery in 50 adult cats utilizing acryl plastic injection method, with discussion about the comparative angiology of the maxillo-facial region. The submental artery of the cat arose from the facial artery at the posterolateral margin of the mylohyoideus muscle in an aspect of a course continuation of the facial artery. But the submental artery in one case arose directly from the external carotid artery at the same portion as the usual origin of the facial artery. The submental artery passed anteroinferomedially between the insertion of the digastricus and the origin of the mylohyoideus muscle with the mylohyoid nerve up to the anterolateral end of the mylohyoideus muscle, where it gave rise to the sublingual artery. The submental artery continued towards the inferoposterior end of the intermandibular synchondrosis beneath the genioglossus muscle originating from the inferior border of the mandible, where it became the median branch by anastomosing with the opposite fellow at the median region. Principal ramifications were observed as follows: the sublingual artery, the premasseteric, the digastric, the mylohyoid, the cutaneous, the genioglossal and the median branches. The general angiological aspect of the submental artery in the cat was similar to that in the dog, except its peripheral ramifications. Lingual gingivae of the lower incisors of the cat were supplied by the median branch of the submental artery, but those of the dog by the sublingual artery. Anastomoses between the bilateral submental arteries were found in many cases of the cat, while unilaterally between the submental and the sublingual arteries in the dog.

Animals↗

PubMed1987

Microvascularization of gingival wound healing using corrosion casts.

The healing process in a wound induced by removal of 6 X 6 mm of gingiva and periosteum from the maxillary attached gingiva of 48 adult mongrel dogs was observed to investigate the potential blood supply for grafts placed on denuded bone. Three-dimensional observations were performed over 12 weeks by scanning electron microscopy (SEM) following the manufacture of corrosion capillary casts by acrylic resin injection. Revascularization in the gingival wound was mainly through formation of new capillaries from those existing below the surrounding epithelium with little new capillary formation from the Volkmann canals. Moreover, the periodontium contributed greatly to the vascularization, which was fastest from the gingival margin. Further, simplification of new capillary loops was also fastest from this direction. Regeneration of the periosteum and periosteal vascular plexus was slow, taking about twice the time of connective tissue and capillaries below the epithelium. The results indicated that blood supply to grafts on denuded bone in the early postgraft period would mainly be provided by capillaries below the epithelium surrounding the recipient bed.

Acrylic Resins↗