Biomedical subjects

Koichi Ito

Publications and source records attributed to Koichi Ito.

At least 19 recordsLinked to original sources

PubMed2025

Loss and Gain of Aqp10 Paralogs With Broad Solute Selectivity in Anguillid Eels.

Aquaporin (Aqp) 10 is a member of the aquaglyceriporin family, which transports small, uncharged solutes in addition to water. Although the solute selectivity of aquaglyceroporins varies, the mechanism of solute selectivity has not yet been fully elucidated. The common ancestor of ray-finned fish possessed two paralogous genes for aquaporin 10, aqp10.1 and aqp10.2, which produce Aqps with different solute selectivities. Most teleosts possess one or more ohnologs derived from aqp10.1 and aqp10.2; however, the common ancestor of Anguilliformes species lost all aqp10.1-derived ohnologs. Anguilliformes species, except Anguilla species, have one aqp10.2b, but recent tandem duplications in the European eel have generated three aqp10.2b paralogs (aqp10.2b1-aqp10.2b3), whose activities remain ambiguous. In this study, we found that the four sites forming the aromatic/arginine (ar/R) selectivity filter in European eel Aqp10.2b1 were identical to those in Aqp10.2b of other species. However, the Y residue at position 3 was replaced with G in the ar/R selectivity filter of Aqp10.2b2 and b3. When expressed in Xenopus oocytes, Aqp10.2b2 and b3 showed higher permeability to urea and boric acid than Aqp10.2b1, indicating that Aqp10.2b2 and b3 acquired broad solute selectivity similar to that of Aqp10.1, which was lost in the ancestral Anguilliformes species. Urea and boric acid permeabilities of Aqp10.2b1 increased when the Y residue at position 3 of the ar/R selectivity filter was replaced with G. Overall, our results outline the history of the loss and gain of Aqp10 paralogs with broad solute selectivity in anguillid eels.

Animals↗

PubMed2005

The effect of IL-1alpha on the expression of matrix metalloproteinases, plasminogen activators, and their inhibitors in osteoblastic ROS 17/2.8 cells.

Interleukin-1 (IL-1) plays key roles in altering bone matrix turnover. This turnover is regulated by matrix metalloproteinases (MMPs), tissue inhibitor of matrix metalloproteinases (TIMPs), and the plasminogen activation system, including tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA) , and plasminogen activator inhibitor type-1 (PAI-1). In this study, we examined the effect of IL-1alpha on the expression of the MMPs, TIMPs, tPA, uPA, and PAI-1 genes in osteoblasts derived from the rat osteosarcoma cell line ROS 17/2.8. The cells were cultured in alpha-minimum essential medium containing 10% fetal bovine serum with 0 or 100 U/ml of IL-1alpha for up to 14 days. The levels of MMPs, TIMPs, uPA, tPA, and PAI-1 expression were estimated by determining the mRNA levels using real-time RT-PCR and by determining protein levels using ELISA. In IL-1alpha cultures, the expression levels of MMP-1, -2, -3, -13, and -14 exceeded that of the control through day 14 of culture, and the expression of MMPs increased markedly from the proliferative to the later stages of culture. The TIMP-1, -2, and -3 expression levels increased from the initial to the proliferative stages of culture. The expression of tPA increased greatly during the proliferative stage of culture, and uPA expression increased throughout the culture period, increasing markedly from the proliferative to the later stages of culture. In contrast, PAI-1 expression decreased in the presence of IL-1alpha through day 14. These results suggest that IL-1alpha stimulate bone matrix turnover by increasing MMPs, tPA, and uPA production and decreasing PAI-1 production by osteoblasts, and incline the turnover to the resolution.

Animals↗

PubMed2005

Novel hydrogel membrane based on copoly(hydroxyethyl methacrylate/p-vinylbenzyl-poly(ethylene oxide)) for biomedical applications: properties and drug release characteristics.

The aim of this study was to synthesize and characterize a novel biocompatible polymeric membrane system and demonstrate its potential use in various biomedical applications. Synthetic hydrogels based on poly(hydroxyethyl methacrylate), poly(HEMA), have been widely studied and used in biomedical fields. A novel copolymer hydrogel was prepared in the membrane form using 2-hydroxyethyl methacrylate monomer (HEMA) and a macromonomer p-vinylbenzyl-poly(ethylene oxide) (V-PEO) via photoinitiated polymerization. A series of poly(HEMA/V-PEO) copolymer membranes with different compositions was prepared. The membranes were characterized using infrared, thermal and SEM analysis. The thermal stabilities of the copolymer membranes were found to be lowered by an increase in the ratio of macromonomer (V-PEO) in the membrane structure. Because of the incorporation of PEO segments, the copolymers exhibited significantly higher hydrophilic surface properties than pure poly(HEMA), as demonstrated by contact angle measurements. Equilibrium swelling studies were conducted to investigate the swelling behavior of the membranes. The equilibrium water uptake was reached in about 4 h. Moreover, the blood protein adsorption and platelet adhesion were significantly reduced on the surface of the PEO containing copolymer membranes compared to control pure poly(HEMA). Drug release experiments were performed in a continuous release system using model drug (vancomycin) loaded copoly(HEMA/V-PEO) membranes. A specific poly(HEMA/V-PEO) membrane formulation possessing the highest PEO content (with a HEMA:V-PEO (mmol:mmol) feed ratio of 112:1 and loaded with 40 mg antibiotic/g polymer) released about 81% of the total loaded drug in 24 h at pH 7.4. This membrane composition provided the best results and can be considered as a potential candidate for a transdermal antibiotic carrier and various biomedical and biotechnological applications.

Anti-Bacterial Agents↗

PubMed2005

Divergent pharmacological activity of novel marine-derived excitatory amino acids on glutamate receptors.

Kainate receptors show a particular affinity for a variety of natural source compounds, including dysiherbaine (DH), a potent agonist derived from the marine sponge Dysidea herbacea. In this study, we characterized the pharmacological activity and structural basis for subunit selectivity of neodysiherbaine (neoDH) and MSVIII-19, which are natural and synthetic analogs of DH, respectively. NeoDH and MSVIII-19 differ from DH in the composition of two functional groups that confer specificity and selectivity for ionotropic glutamate receptors. In radioligand binding assays, neoDH displayed a 15- to 25-fold lower affinity relative to that of DH for glutamate receptor (GluR)5 and GluR6 kainate receptor subunits but a 7-fold higher affinity for kainate (KA)2 subunits, whereas MSVIII-19 displaced [(3)H]kainate only from GluR5 subunits but not GluR6 or KA2 subunits. NeoDH was an agonist for kainate and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in patch-clamp recordings; in contrast, MSVIII-19 acted as a potent antagonist for homomeric GluR5 receptor currents with weaker activity on other kainate and AMPA receptors. Neither neoDH nor MSVIII-19 activated group I metabotropic GluRs. Homology modeling suggests that two critical amino acids confer the high degree of selectivity between the dysiherbaine analogs and the GluR5 and KA2 subunits. In summary, these data describe the pharmacological activity of two new compounds, one of which is a selective GluR5 receptor antagonist that will be of use for understanding native receptor function and designing more selective ligands for kainate receptors.

Alanine↗

PubMed2005

IL-1 alpha stimulates the formation of osteoclast-like cells by increasing M-CSF and PGE2 production and decreasing OPG production by osteoblasts.

Interleukin-1alpha (IL-1alpha) is one of the most potent bone-resorbing factors involved in the bone loss that is associated with inflammation. We examined the effect of the inflammatory mediator IL-1alpha on the expression of macrophage colony-stimulating factor (M-CSF), osteoprotegerin (OPG), and prostaglandin E2 (PGE2) in rat osteoblasts, and the indirect effect of IL-1alpha on the formation of osteoclast-like cells. Osteoblasts were cultured in alpha-minimum essential medium containing 10% fetal bovine serum with or without 100 units/ml of IL-1alpha for up to 14 days. The gene and protein expression of M-CSF and OPG were estimated by determining mRNA levels using the real-time polymerase chain reaction and protein levels using Western blot analysis. PGE2 expression was determined using an enzyme-linked immunosorbent assay. The formation of osteoclast-like cells was estimated using tartrate-resistant acid phosphatase (TRAP) staining of osteoclast precursors in culture with conditioned medium from IL-1alpha-treated osteoblasts and the soluble receptor activator of NF-kappaB ligand (RANKL). M-CSF and PGE2 expression in osteoblasts increased markedly in cells cultured with IL-1alpha, whereas OPG expression decreased. The conditioned medium containing M-CSF and PGE2 produced by IL-1alpha-treated osteoblasts and soluble RANKL increased the TRAP staining of osteoclast precursors. These results suggest that IL-1alpha stimulated the formation of osteoclast-like cells via an increase in M-CSF and PGE2 production, and a decrease in OPG production by osteoblasts.

Animals↗

PubMed2005

Enamel matrix derivative is a potent inhibitor of breast cancer cell attachment to bone.

This study examined whether enamel matrix derivative (EMD) inhibits the adhesion of cancer cells to bone. A typical breast cancer cell line, MCF-7, was used. Conditioned human osteosarcoma cell (Saos-2) medium was used as extracellular bone matrix (ECBM) to measure cell attachment. MCF-7 cells were incubated on ECBM-coated culture plates with or without soluble EMD, Arg-Gly-Asp (RGD) sequence blocking peptides, recombinant bone sialoprotein (rBSP), or specific integrin antibodies, and the attached cells were quantified using toluidine blue staining. EMD markedly reduced the attachment of MCF-7 cells to ECBM in a dose-dependent manner. An RGD peptide (GRGDSP) and recombinant BSP inhibited cell attachment to the same degree as EMD. Similarly, anti-alphavbeta3 integrin antibody strongly reduced cell attachment, whereas anti-alphavbeta5 and anti-beta1 integrin antibodies had less marked effects on cell attachment. These results show that EMD inhibits MCF-7 cell attachment to a bone matrix and that it might be useful as an anti-adhesive agent for breast cancer cells to bone in vivo.

Antibodies, Monoclonal↗

PubMed2005

Relationship between plasma concentration levels of risperidone and clinical effects in the treatment of delirium.

The present study aimed to examine the relationship between plasma concentration levels of risperidone and clinical effects in the treatment of delirium. We conducted a prospective, open-label, flexible-dose study of risperidone oral solution. Ten patients with delirium were assessed using Delirium Rating Scales. Plasma concentration levels of risperidone were measured 30 min after the first administration of a 0.5 mg dose. Two patients with high plasma levels had adverse effects and one patient with the lowest plasma level did not achieve remission; the remaining seven patients achieved remission without any adverse effects. A highly significant negative correlation was observed in these responders without adverse effects between the plasma levels and durations of treatment until remission (r=-0.861, P=0.0095). The plasma concentration level of risperidone at 30 min after the first 0.5 mg dose may be a favourable response predictor in the treatment of delirium. Further studies in larger samples are needed to verify this preliminary finding.

Administration, Oral↗

PubMed2005

Heterologous expression of Aquifex aeolicus ribosome recycling factor in Escherichia coli is dominant lethal by forming a complex that lacks functional co-ordination for ribosome disassembly.

Recycling the post-termination ribosomal complex requires the co-ordinated effort of the ribosome, ribosome recycling factor (RRF) and elongation factor EF-G. Although Aquifex aeolicus RRF (aaRRF) binds Escherichia coli ribosomes as efficiently as E. coli RRF, the resulting complex is non-functional and dominant lethal in E. coli, even in the presence of homologous A. aeolicus EF-G. These findings suggest that the E. coli post-termination ribosomal complex with aaRRF lacks functional co-ordination with EF-G required for ribosome recycling. A chimeric EF-G (E. coli domains I-III, A. aeolicus domains IV-V) or an A. aeolicus EF-G with distinct mutations in the domain I-II interface could activate aaRRF. Furthermore, novel mutations that localize to one surface of the L-shape structure of aaRRF restored activity in E. coli. These aaRRF mutations are spatially distinct from mutations previously described and suggest a novel active centre for coupling EF-G's G domain motor action to ribosome disassembly.

Amino Acid Sequence↗

PubMed2005

Three-dimensional evaluation for augmented bone using guided bone regeneration.

OBJECTIVE: This study evaluated new bone regeneration beyond the skeletal envelope within an occlusive titanium cap on rabbit calvaria using microfocus computed tomography images. METHODS: In 10 rabbits, the calvaria was exposed and a circular groove was prepared. After penetrating the marrow, a standard hemispherical titanium cap was placed in the groove and covered with a cutaneous flap. After 1 or 3 months, the animals were killed and the calvariae and titanium caps were dissected. After taking microfocus computed tomography images of the specimens, histological sections were made. The specimens were observed using three-dimensional images constructed from the microfocus computed tomography images, and the histological sections were examined to compute bone parameters. RESULTS: The three-dimensional images and histological specimens showed that new bone formed in flat, cup-like, and dome shapes. The bone parameters trabecular thickness and the proportion of marrow space to the capacity of the titanium cap increased, whereas bone density decreased, and there were significant differences between the 1- and 3-month groups. DISCUSSION: First, a cylinder of new bone formed from the existing bone. Gradually, bone formed along the cap wall and the new tissue formed in a crater indented centrally. Finally, the new tissue formed in the shape of a dome. CONCLUSION: Trabecular bone formed along the wall of the titanium cap, and bone filled the inside of the cap within 3 months.

Animals↗

PubMed2005

Inhibitory effects of a super pulsed carbon dioxide laser at low energy density on periodontopathic bacteria and lipopolysaccharide in vitro.

OBJECTIVE AND BACKGROUND: Previous studies have described the effect of irradiation by a carbon dioxide (CO2) laser at high energy density on oral bacteria, and various side-effects have also been observed. However, no published studies have examined the effect of irradiation by a CO2 laser at low energy density on oral bacteria. The purpose of this study was to investigate the effects of super pulsed CO2 laser irradiation on periodontopathic bacteria and lipopolysaccharide (LPS). METHODS: Bacterial suspensions of two species of periodontopathic bacteria received laser irradiation at energy densities of 0-12.5 J/cm2. The suspensions were then spread over agar plates and incubated anaerobically. The bactericidal effects were evaluated based on colony formation. Samples of LPS were laser-irradiated at energy densities of 0-12.5 J/cm2. The biological activity was measured, and LPS was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS: The irradiation at low energy densities of 7.5 and 12.5 J/cm2 killed more than 99.9 and 99.999% of Porphyromonas gingivalis and more than 99% of Actinobacillus actinomycetemcomitans was sterilized by the irradiation at 7.5 J/cm2. LPS biological activity was significantly decreased by laser irradiation at energy densities of more than 7.5 J/cm2 (p < 0.05), and the components of LPS analyzed by SDS-PAGE was diminished non-specifically. CONCLUSION: The results indicate that CO2 laser irradiation at low power is capable of bactericidal effect on periodontopathic bacteria and decreasing LPS activity.

Aggregatibacter actinomycetemcomitans↗

PubMed2005

A cavernous haemangioma of the thyroid gland.

Haemangioma of the thyroid gland is extremely rare. We report a case of a cavernous haemangioma of the neck that was located both inside and outside the thyroid gland of a 21-year-old man. Ultrasonography of the neck revealed numerous calcified nodules. Computed tomography (CT) showed a large calcified soft tissue mass in the right lobe of the thyroid. Based on the imaging findings a papillary thyroid carcinoma was suspected, but examination of the surgical specimen revealed a huge cavernous haemangioma containing numerous phleboliths.

Adult↗

PubMed2005

Ratio of serum free triiodothyronine to free thyroxine in Graves' hyperthyroidism and thyrotoxicosis caused by painless thyroiditis.

The serum T3 to T4 ratio is a useful indicator for differentiating destruction-induced thyrotoxicosis from Graves' thyrotoxicosis. However, the usefulness of the serum free T3 (FT3) to free T4 (FT4) ratio is controversial. We therefore systematically evaluated the usefulness of this ratio, based on measurements made using two widely available commercial kits in two hospitals. Eighty-two untreated patients with thyrotoxicosis (48 patients with Graves' disease and 34 patients with painless thyroiditis) were examined in Kuma Hospital, and 218 patients (126 with Graves' disease and 92 with painless thyroiditis) and 66 normal controls were examined in Ito Hospital. The FT3 and FT4 values, as well as the FT3/FT4 ratios, were significantly higher in the patients with Graves' disease than in those with painless thyroiditis in both hospitals, but considerable overlap between the two disorders was observed. Receiver operating characteristic (ROC) curves for the FT3 and FT4 values and the FT3/FT4 ratios of patients with Graves' disease and those with painless thyroiditis seen in both hospitals were prepared, and the area under the curves (AUC), the cut-off points for discriminating Graves' disease from painless thyroiditis, the sensitivity, and the specificity were calculated. AUC and sensitivity of the FT(3)/FT(4) ratio were smaller than those of FT(3) and FT(4) in both hospitals. The patients treated at Ito hospital were then divided into 4 groups according to their FT4 levels (A: < or =2.3, B: >2.3 approximately < or =3.9, C: 3.9 approximately < or =5.4, D: >5.4 ng/dl), and the AUC, cut-off points, sensitivity, and specificity of the FT(3)/FT(4) ratios were calculated. The AUC and sensitivity of each group increased with the FT4 levels (AUC: 57.8%, 72.1%, 91.1%, and 93.4%, respectively; sensitivity: 62.6%, 50.0%, 77.8%, and 97.0%, respectively). The means +/- SE of the FT3/FT4 ratio in the Graves' disease groups were 3.1 +/- 0.22, 3.1 +/- 0.09, 3.2 +/- 0.06, and 3.1 +/- 0.07, respectively, versus 2.9 +/- 0.1, 2.6 +/- 0.07, 2.5 +/- 0.12, and 2.3 +/- 0.15, respectively, in the painless thyroiditis groups. In the painless thyroiditis patients, the difference in the FT3/FT4 ratio between group A and group D was significant (p<0.05). Thus, the FT3/FT4 ratio in patients with Graves' disease likely remains unchanged as the FT4 level rises, whereas this ratio decreases as the FT4 level rises in patients with painless thyroiditis. In conclusion, the FT3/FT4 ratios of patients with painless thyroiditis overlapped with those of patients with Graves' disease. However, this ratio was useful for differentiating between these two disorders when the FT4 values were high.

Adult↗

PubMed2005

Enamel matrix derivative stimulates core binding factor alpha1/Runt-related transcription factor-2 expression via activation of Smad1 in C2C12 cells.

BACKGROUND: Although enamel matrix derivative (EMD) can promote osteogenic differentiation of the pluripotent mesenchymal precursor cell line, C2C12, the molecular mechanism that underlies this phenomenon is unclear. The purpose of this study was to determine which molecules in EMD stimulate osteogenic differentiation. METHODS: C2C12 cells were cultured in 5% serum-containing medium to induce differentiation, either with or without the addition of EMD. The expression of core binding factor alpha1/runtrelated transcription factor-2 (Cbfa1/Runx2) was measured using Northern blot, Western blot, and/or real-time polymerase chain reaction (R-PCR) analysis. Phosphorylation of mothers against decapentaplegic homolog 1 (Smad1) and bone morphogenetic protein (BMP)-like molecules in EMD was determined by Western blot. RESULTS: EMD increased Cbfa1/Runx2 mRNA and protein expression substantially. EMD also induced phosphorylation of Smad1. Noggin inhibited the EMD-induced phosphorylation of Smad1 markedly, and also partially blocked EMD-induced Cbfa1/ Runx2 mRNA expression. In the Western blot analysis, single bands that corresponded to approximately 15 and approximately 17.5 kDa proteins were recognized in EMD by anti-BMP-2/4 and anti-BMP-7 antibodies, respectively. CONCLUSIONS: Our study demonstrates that EMD stimulates Cbfa1/Runx2 expression and the phosphorylation of Smad1, and that both of these processes can be blocked by noggin. Therefore, the osteogenic activity of EMD may be mediated by BMPlike molecules in EMD.

Animals↗

PubMed2005

Periodic exacerbation of gingival inflammation during the menstrual cycle.

Sex hormones are believed to be a risk factor for periodontitis because of their ability to proliferate specific periodontal microorganisms and affect host immunologic response. In this case report, gingival redness and swelling occurred during the menstrual cycle, although the patient maintained good oral hygiene during periodontal treatment. Medical history revealed that exacerbation of gingival inflammation corresponded to the menstrual cycle and occurred during the ovulation period, when estrogen levels are high. Mean bleeding index of the ovulation period (18.9%) showed higher levels than that during the menstrual phase (5.3%). This case indicates that frequent and effective maintenance should be provided while considering the influence of the menstrual cycle, as sex hormones may be involved in exacerbating gingival inflammation.

Adult↗

PubMed2005

A marker of oxidative stress in saliva: association with periodontally-involved teeth of a hopeless prognosis.

The aim of this study was to determine the association between levels of a marker of oxidative stress, 8-hydroxydeoxyguanosine (8-OHdG), in saliva and the presence of teeth with a hopeless prognosis as a result of advanced periodontitis. Thirty-four periodontitis patients were divided into two groups based on the presence or absence of periodontally-involved teeth of hopeless prognosis. Salivary levels of 8-OHdG in those with were significantly higher than in subjects without periodontally-involved teeth of hopeless prognosis (4.78 +/- 0.14 ng/ml and 2.35 +/- 0.18 ng/ml, respectively). We also evaluated 8-OHdG levels in gingival crevicular fluid (GCF) of teeth with advanced periodontal destruction (mean probing depth = 7.2). In this case, 8-OHdG was detected only from those periodontally-involved teeth of hopeless prognosis, and only in some cases (8 out of 18 samples). These data suggest that periodontally-involved teeth of hopeless prognosis are a major source of salivary 8-OHdG. Measurement of salivary 8-OHdG levels may prove to be useful in identifying patients with teeth of hopeless prognosis.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2005

[Confirmation of non-permitted dyes detected in Akasu (red vinegar) by LC/MS].

Suitable liquid chromatography/mass spetrometry (LC/MS) conditions were examined for Amaranth, Red 2G (R2G), Azo Rubine (Azo), Fast Red E (FRE) and Brilliant Blue FCF, which were detected in Akasu, a red vinegar made in Hong Kong from sake lees, on both thin layer chromatography (TLC) and photodiode array high-performance liquid chromatography (PDA-HPLC). Molecular-related ions for each dye were detected with excellent sensitivity by LC/MS using electro-spray ionization with negative ion mode, capillary voltage 3.00 kV, cone voltage 50 V and desolvation temperature 400 degrees C. LC/MS analysis of refined Akasu under these conditions enabled us to obtain clear mass spectra of R2G, Azo and FRE, which were present at trace levels in the Akasu. The results were consistent with those from TLC and PDA-HPLC. These experiments suggested that LC/MS analysis is applicable for confirmation of dyes in food.

Acetic Acid↗

PubMed2005

[Structural analysis of unknown dyes detected in hajikami (ginger pickled in vinegar)].

Hajikami (ginger pickled in vinegar) is often used as a relish for grilled fish, and it often contains coloring agents. We detected Rose Bengal (R105) and two unknown dyes in some Hajikami by thin layer chromatography. In this study, we tried to characterize these unknown dyes by HPLC with photodiode array detection (PDA-HPLC), liquid chromatography/mass spectrometry (LC/MS) and nuclear magnetic resonance (NMR). PDA-HPLC analysis showed that the spectra of the unknown dyes resembled that of R105, suggesting the molecular structures of these two dyes are similar to that of R105. Furthermore, LC/MS analysis suggested that the these dyes are R105 in which one or two iodines are replaced by hydrogen. Finally, the two dyes were determined by 1H-NMR and 13C-NMR to be 4,5,6,7-tetrachloro-3',6'-dihydroxy-2',7'-diiodo spiro[isobenzofuran- 1 (3H),9'-[9H]xanthen]-3-one disodium salt and 4,5,6,7-tetrachloro-3',6'-dihydroxy-2',7'-diiodo spiro[isobenzofuran-1(3H),9'[9H]xanthen]-3-one disodium salt.

Chromatography, High Pressure Liquid↗

PubMed2004

Clinical evaluation of color Doppler imaging for the differential diagnosis of thyroid follicular lesions.

Ultrasonography (US) of the thyroid gland has recently proved to be a useful clinical diagnostic method, and the newly developed high-resolution US with a color Doppler flow mapping function can reveal fine details of the thyroid gland and the hemodynamic features of a thyroid neoplasm. US can yield a diagnostic accuracy of more than 90% for thyroid carcinoma, especially papillary carcinoma. However, neither conventional B-mode US imaging nor aspiration biopsy cytology has delivered satisfactory results for follicular carcinoma. The aim of this study was to evaluate the clinical usefulness of color Doppler imaging for the differential diagnosis of thyroid follicular lesions. A color Doppler scan was performed in 310 patients with a solitary cold nodule, and a combination of B-mode US and color Doppler findings, including tumor vascularity and results of a fast Fourier transform (FFT) analysis were used to create the following diagnostic grading system for differential diagnosis of follicular lesions: grade 1, benign follicular lesion [no color flow mapping (CFM) inside the nodule]; grade 2, benign peripheral type [CFM only in peripheral area, pulsatility index (PI) < 1.0]; grade 3, suspected follicular carcinoma (penetrating CFM, vascularity moderate); grade 4, follicular carcinoma (high-velocity penetrating CFM, PI = 1.0). All patients were subjected to surgical resection, and histologic examination was used to confirm the diagnosis. The grades of the 177 adenomatous nodules were as follows: grade 1, 46.9%; grade 2, 48.0%; grade 3, 5.1%; grade 4, 0%. The corresponding percentages for the 89 follicular adenomas were 16.9%, 49.4%, 30.3%, and 3.4%; and for the 44 follicular carcinomas they were 0%, 13.6%, 45.5%, and 40.9%. On the assumption that grade 1 and 2 lesions are benign and grade 3 and 4 lesions are malignant, 38 of the 44 follicular carcinomas and 227 of the 266 benign tumors had been accurately diagnosed, yielding a sensitivity of 88.9%, a specificity of 74.2%, and an accuracy of 81.0% for the grading system. Color Doppler imaging of 310 follicular tumors has revealed that high-velocity pulsatile blood flow penetrating the tumor is a characteristic finding of follicular carcinoma and is a new diagnostic criterion for performing color Doppler imaging. The differential diagnostic grading scores for color Doppler examinations and the results of FFT analysis demonstrate that US with the color Doppler function can play an important role in the differential diagnosis of thyroid tumors.

Adenoma↗