Biomedical subjects

F Iida

Publications and source records attributed to F Iida.

172 records · Page 10Linked to original sources

PubMedDate not supplied

Management of tracheal wall resection for thyroid carcinoma by tracheocutaneous fenestration and delayed closure using auricular cartilage.

BACKGROUND: In the case of advanced thyroid carcinoma invading the trachea, surgical procedures for tracheal resection are selected in relation to the degree of invasion. We created a tracheocutaneous fenestration that was later closed with a free auricular cartilage autograft. We present a simple and effective method for permanent closure of tracheostoma. METHODS: The surgical procedure for delayed closure consists of three steps: (1) preparing the hinge flap with additional undermining of the subcutaneous layer and the strap muscles; (2) removing a portion of the conchal cartilage from the auricle, which is easily performed with a semicircular skin incision along the anthelix of the ear; and (3) placing the conchal cartilage with its convex surface upward just over the sutured hinge flap layer. RESULTS: Under local anesthesia, we successfully employed this reconstructive procedure for 5 patients. Unfortunately, however, in one patient, we had to reopen the closed tracheocutaneous fenestration on the second postoperative day because of an acute problem that was independent of the closure surgery. Four patients remain in satisfactory condition for more than 2 years since the closure of tracheostoma. CONCLUSIONS: The auricular cartilage free graft is a relatively simple procedure which supplies tracheal wall skeletal support for the permanent closure of the tracheocutaneous fenestration.

Aged↗

PubMedDate not supplied

Clinical and pathologic properties of small differentiated carcinomas of the thyroid gland.

Ninety-one small differentiated thyroid carcinomas less than 10 mm in size treated during the last 33 years were subjected to clinical study. In 44 of the 91 cases, tumor was found incidentally at surgery, while in the remaining 47 a thyroid mass was palpable before operation. A preoperative diagnosis of carcinoma could not be made in nodules less than 5 mm in size. Ultrasonographic examination is now extending the limits of exact diagnosis. Metastasis was found in 16 of 33 patients who had lymph nodes dissected. Metastatic lymph nodes were distributed in the same sites as those with thyroid carcinomas larger than 10 mm. Pathologic examination was carried out in 108 small carcinomas including cases from an affiliated hospital. Histologically, all of them were papillary or follicular carcinomas. The growth pattern of the tumors was divided into 5 groups: 23 were nonencapsulated sclerosing type, 29 encapsulated type without capsule invasion, 48 encapsulated type with capsule invasion, 4 the infiltrative type, and 4 the round type. Lymph node metastasis and intraglandular dissemination were found most frequently in the infiltrative type, followed by the encapsulated type with invasion. The results suggest the necessity of lymph node dissection and lobectomy for patients with these histological types of small carcinomas who had only local removal of the tumor.

Adult↗

PubMedDate not supplied

Clinicopathologic characteristics and postoperative outcome in Japanese and Chinese patients with thoracic esophageal cancer.

We evaluated the clinicopathologic findings and surgical results of 140 patients with thoracic esophageal cancer treated at Shinshu University, Japan (Shinshu group), and compared them with those from 1164 patients treated at Hebei Medical College, China (Hebei group) to determine if the two groups showed any differences. The Shinshu group had significantly higher incidences of elderly patients (>70 years of age), male patients, and tumors located at the lower esophagus (p < 0.01). In the Hebei group, although the depth of tumor invasion was more advanced, the incidence of nodal metastasis was significantly lower (p < 0.01). Operative death and postoperative complications were more frequent in the Shinshu group. Comparison of the postoperative survival curves revealed significantly longer survival of patients with pT2 or pT3 tumor in the Hebei group (p < 0.01), but there were no significant differences between the two groups when the lesions were classified by pTNM stage. This study demonstrated several differences between the patients in the two areas in regard to the clinicopathologic characteristics of thoracic esophageal cancer. The most important characteristic of the esophageal cancer in the Hebei group appears to be the low incidence of nodal metastasis.

Adult↗

PubMedDate not supplied

Assessment of proliferative activity of glandular cells in hyperfunctioning parathyroid gland using flow cytometric and immunohistochemical methods.

The proliferative activity of epithelial cells in hyperfunctioning parathyroid glands was estimated by flow cytometric and immunohistochemical procedures. A total of 30 parathyroid glands, 29 hyperfunctioning glands, and 1 normal gland were studied. The pathology of the 29 glands was determined to be hyperplasia in 19 and adenoma in 10. The S-phase cell population was expressed in terms of the S-phase fraction (%SPF) calculated from the histogram by DNA flow cytometry and in terms of the BrdU immunostaining labeling index (BrdU LI). Cells in all stages of the cell cycle were studied by Ki-67 immunostaining and expressed in terms of the labeling index (Ki-67 LI). Both BrdU LI and Ki-67 LI values were low, ranging from 0% to 0.58% and from 0.21% to 2.62%, respectively. The BrdU LIs were lower than the Ki-67 LIs, ranging from one-sixth to one-twelfth of the values depending on the disease. There were significant correlations between the two indices (p < 0.001). The %SPF determined by flow cytometry was consistently higher than both the BrdU LI and the Ki-67 LI. This discrepancy cannot be explained precisely, and further improvements are required for the flow cytometric analysis of %SPF. The cell cycle study by BrdU and Ki-67 immunohistochemistry suggested that the glandular cells of the hyperfunctioning parathyroid were characterized by low proliferative activity. No evidence of rapid cell turnover rate assumed from the flow cytometric study could be observed in the hyperfunctioning parathyroid gland.

Adenoma↗

PubMedDate not supplied

Photoinduced prevention of tissue adhesion.

Postoperative tissue adhesion causes retarded wound healing and the need for reoperation; it can even be life threatening. In this report, the authors present prototype materials and performance of newly developed tissue adhesion prevention technology based on photocurable polysaccharides. Polysaccharides used were hyaluronic acid and chondroitin sulfate, both of which were partially derived with photoreactive groups such as cinnamoyl, coumarin, and thymine. Photoreactive hyaluronic acids with low degrees of derivatization were soluble in water. Films of cinnamated hyaluronic acid or an aqueous solution of cinnamated chondroitin sulfate were photocured by ultraviolet irradiation, resulting in water adsorbable films or water swollen gels, respectively. Gelation was due to intermolecular dimerization between cinnamoyl groups. The authors provide two potentially applicable examples: 1) a photocured, water swollen hydrogel film, and 2) a photocurable chondroitin sulfate buffer solution. The authors used hydrogel films to cover the peritoneum after mechanically injuring its surface. Histologic examination showed neither tissue nor cell adhesion, and only a minimal inflammatory response. When tissues were coated with a photocurable chondroitin sulfate solution, the viscous solution was converted to a hydrogel upon ultraviolet irradiation, resulting in in situ tissue covering. Although an optimal molecular design has not yet been found, unique features of mucopolysaccharides (e.g., high water uptake; biodegradability and bioresorbability; and nontoxicity of photodimerizable groups) may result in the development of photoinduced tissue adhesion prevention technology.

Animals↗

PubMedDate not supplied

Improved patency of an elastomeric vascular graft by hybridization.

A newly devised hybrid graft with high antithrombogenicity for small caliber vascular grafts was developed. The design concept was based on the incorporation of a compliant open cell structured graft, autogenous endothelial cells (ECs), and artificial basement membrane. The latter, a gel complex of type I collagen and dermatan sulfate that showed enhanced adhesion and growth of ECs but reduced platelet adhesion, was coated onto a microporous polyurethane graft (internal diameter, 3 mm; length, 4.5 cm), with near-natural compliance. Ten seeded grafts were implanted bilaterally into the carotid arteries of dogs; anticoagulant or antiplatelet therapy was not administered. This hybrid graft showed a marked improvement in patency at 1 month compared with that of simply preclotted grafts (control specimens). This result was explained by the almost complete endothelialization when the graft was implanted, a high degree of adherent strength resistance to shear stress, and a high proliferative potential. Thus, this approach of combining biomechanical and cellular engineering designs may lead to an important functional small caliber graft.

Animals↗

PubMedDate not supplied

Thyroid carcinoma associated with hot nodule diagnosed by ultrasonography.

A patient with thyroid carcinoma showing a hot nodule on radioiodine scintigraphy was examined by ultrasonography and was revealed to have occult carcinoma co-existing with adenomatous goiter. Ultrasonography should be performed to establish the diagnosis even if radioiodine scintigraphy reveals a hot nodule, as should fine-needle aspiration biopsy.

Adult↗

PubMedDate not supplied

Development of a hierarchically structured hybrid vascular graft biomimicking natural arteries.

A hierarchically structured hybrid vascular graft, resembling the layered structure of the intima and the media of a natural artery, is expected to exhibit structural stability and function similar to those of an artery. Two models of hybrid vascular grafts were constructed on knitted Dacron grafts (internal diameter, 4 mm; length, 6 cm; Golaski Laboratories, Inc., Philadelphia, PA) in vitro. The model I graft consisted of only an endothelial cell (EC) monolayer, and the model II graft was hierarchically structured with an EC monolayer and smooth muscle cell (SMC) multilayers embedded in a mixed gel of type I collagen and dermatan sulfate. Both models were implanted bilaterally in carotid arteries of 11 dogs for up to 12 weeks without anticoagulant. All grafts were patent after the implantation. There was a marked difference in the formation of the neomedia between the two models at 2 weeks: only a collagenous layer was observed beneath the EC monolayer in model I grafts, whereas the reconstructed neomedia consisting of proliferating SMCs and extracellular matrix was observed in model II grafts. In model I grafts at 2 weeks, the luminal surface with a wavelike form, along with crimps of the vascular graft, was almost endothelialized, but EC orientation was disorganized at the troughs of the crimps. Leukocyte adhesion on ECs and migration into their interstices were observed in some areas. Such events were infrequent in model II grafts at 2 weeks. Model II grafts at 12 weeks had an integrated neomedia comparable to that of a natural artery: SMCs exhibited dense accumulation and circumferential orientation.(ABSTRACT TRUNCATED AT 250 WORDS)

Actins↗

PubMedDate not supplied

Newly designed tissue adhesion prevention technology based on photocurable mucopolysaccharides. In vivo evaluation.

Tissue adhesion after surgery occasionally causes serious complications. The authors have been developing photocurable mucopolysaccharides for a tissue adhesion prevention material that meets requirements such as nonadherent surface characteristics, biocompatibility, biodegradability in accordance with the wound healing rate, and nontoxicity. Mucopolysaccharides (hyaluronic acid and chondroitin sulfate) partially derived with photoreactive groups, such as cinnamate or thymine, were subjected to ultraviolet (UV) irradiation to produce water insoluble gels via intermolecular photodimerization of photoreactive groups. Photocured films that covered injured liver surfaces of rats were implanted for as long as 4 weeks and histologically evaluated. In vivo performance, including tissue adhesion prevention, biodegradability, and mechanical flexibility of the films, was found to be controlled by the type of mucopolysaccharides, the type of photoreactive groups, and their degrees of substitution (DS). Photocured films with lower DS, which had high water swellability and flexibility, prevented tissue adhesion and exhibited enhanced biodegradability. As an increase in DS occurred, tissue adhesion prevention, biodegradability, and mechanical flexibility were reduced. Control of the biodegradation rate was feasible. Minimum inflammatory reaction was noticed.

Animals↗

PubMedDate not supplied

An in vitro endothelialized compliant vascular graft minimizes anastomotic hyperplasia.

The authors developed a hybrid vascular graft consisting of three components: a polyurethane (PU) graft (internal diameter = 3 mm; length: 5 cm) with a compliance similar to that of natural arteries; an artificial basement membrane composed of a complex gel of Type I collagen and dermatan sulfate; and an autogenous endothelial cell (EC) monolayer constructed before implantation. As a continuation of their previous study that focused on antithrombogenicity for as long as 1 month after implantation, the authors evaluated the antihyperplastic characteristics of their hybrid vascular graft for longer implantation periods. The hybrid grafts were implanted bilaterally into carotid arteries of dogs without anticoagulant or anti-platelet agents. The implantation period ranged from 6 to 26 weeks. The overall patency rate observed in this study was 70%. Histologic evaluation of grafts revealed that luminal surfaces of the arteries and grafts joined uniformly and smoothly. The mean initimal thickness of grafts was approximately 80 microns at 12 weeks; there was no statistically significant difference in the thickness between portions of the graft. Little additional increase was observed at 26 weeks. The intimal thickness of adjacent arteries was small. Thus, anastomotic hyperplasia was considered minimized. These encouraging results were explained in terms of synergistic activities of the compliant PU graft and durable EC monolayer as follows. The PU graft, which was fabricated to have the same compliance as that of natural arteries, minimized the compliance mismatch at the anastomoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗