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Biomedical subjects

Hideaki Suzuki

Publications and source records attributed to Hideaki Suzuki.

At least 19 recordsLinked to original sources
PubMed2006

Association of verrucous carcinoma and inverted papilloma in the sinonasal tract.

It is well known that inverted papilloma (IP) is sometimes associated with malignancies; however, the association of IP with verrucous carcinoma (VC) is extremely rare. We herein report a case of IP in the nasal cavity with VC in the maxillary sinus. A 73-year-old Japanese woman presented with a 3-month history of right-sided nasal obstruction and repetitive epistaxis. A biopsy of the mass was performed and the pathological result proved to be IP. Computed tomography and magnetic resonance imaging revealed a moderately enhanced soft-tissue lesion filling the right nasal cavity and a ring-enhanced expansive lesion in the maxillary sinus. Under a tentative diagnosis of IP of the nasal cavity with maxillary empyema, she underwent right medial maxillectomy via a lateral rhinotomy approach, and a histopathological diagnosis of IP in the nasal cavity with VC in the maxillary sinus was obtained. Her postoperative clinical course was uneventful. She is currently free from symptoms, and there is no evidence of recurrence 5 months after surgery. The pathology, clinical manifestation, and treatment of VC associated with IP are reviewed from literature.

Aged↗
PubMed2006

Mathematical folding of node chains in a molecular network.

Under the framework of network artificial chemistry (NAC), a method to construct a phenotypic machine from genotypic information is proposed. The genotype is expressed as a sequence of nodes (a node chain) with symbol data. According to an implemented algorithm, a chain is agglomerated, tangled, and finally folded into a node cluster that works as a control-flow machine in the network. Two examples of control-flow clusters, splitase and replicase, are presented and their functionality is demonstrated. Several meanings and future research directions are discussed.

Algorithms↗
PubMed2006

Eikenella corrodens in head and neck infections.

BACKGROUND: Eikenella corrodens (E. corrodens) is a Gram-negative facultative anaerobic bacillus that originally was thought to be an attenuated and indigenous bacterium. In recent years, a number of reports have documented that E. corrodens can be a potential pathogen not only in immunocompromised patients but also in hosts with normal immunity. We herein study E. corrodens infections of the head and neck encountered in our department. METHODS: Twenty-two consecutive patients treated in our department for E. corrodens infections of the head and neck were retrospectively analyzed. Microbial specimens were subjected to light microscopic examination, aerobic culture using chocolate and sheep blood agar media, and anaerobic culture using Brucella HK agar medium. Cultured bacteria were subjected to antimicrobial susceptibility tests by means of the broth microdilution method. RESULTS: There were 16 males and 6 females with an average age of 29.9 years. Two patients had malignancy, while the other patients had no particular risk factors or underlying diseases. Infected sites were the ear in 6 cases, pharynx in 12 cases (tonsil in 10 cases), paranasal sinuses in 3 cases, and salivary gland in 1 case. Seventeen patients suffered polymicrobial infections. Staphylococcus and Streptococcus were the most frequently detected pathogens coexisting with E. corrodens, and mixed infections of E. corrodens and Streptococcus milleri group bacteria were prone to form abscesses. Isolated E. corrodens was susceptible to third-generation cephems (MIC90 = 0.15-0.25 microg/ml), carbapenems (MIC90 < or = 0.15 microg/ml), and new quinolones (MIC90 < or = 0.15 microg/ml), and resistant to oxacillin (MIC90 > 8 microg/ml), cefazolin (MIC90 > 4 microg/ml), macrolides (MIC90 = 4-8 microg/ml), and clindamycin (MIC90 > 4 microg/ml). CONCLUSIONS: E. corrodens infections of the head and neck occur most frequently in the tonsil even in hosts with normal immunity. Coexistence with Streptococcus milleri group bacteria and the use of ineffective antibiotics can be exacerbating factors. First-choice drugs for E. corrodens infections should be third-generation cephems, carbapenems, or new quinolones.

Adolescent↗
PubMed2006

Human Shugoshin mediates kinetochore-driven formation of kinetochore microtubules.

The conserved protein Shugoshin (Sgo) plays a role in the maintenance of centromeric cohesion in mitosis and meiosis. Human Shugoshin (hSgo) was first identified as an overexpressed protein in breast cancers. Here we demonstrate that hSgo mediates kinetochore-driven formation of kinetochore -microtubules (MTs) during bipolar spindle assembly. The regulated overexpression of full-length hSgo, or of truncated proteins containing both the conserved N-terminal coiled-coil domain and C-terminal basic domain, resulted in hSgo localization at centromere at early mitosis and was associated with aberrant nucleation and formation of bundles of kinetochore-MTs. The mid-portion of hSgo, between the N- and C-terminal domains, includes both a functional domain for centromeric cohesion and a regulatory domain for spindle assembly. The cells overexpressing natural alternative splicing isoforms, which are almost completely defective for the mid-portion of the hSgo protein, showed premature centromere separation (PCS) and aberrant MT connections. These isoforms are mildly overexpressed in HEK293 cells. On the other hand, cells expressing a truncated protein, defective in the lysine-rich region of the mid-portion, arrested at mitosis due to persistent abnormal MT connections and not because of PCS. Aberrant MT connections were predominantly observed in spindle regions where chromosomes were clustered. Interestingly, we also found that hSgo is rapidly exchanged at kinetochores at early mitosis. Based on these results, we conclude that hSgo may be diffusible and have a role in proper kinetochores MTs attachment.

Cell Cycle Proteins↗
PubMed2006

Checkerboard-type charge-ordered state of a pressure-induced superconductor, beta-(meso-DMBEDT-TTF)2PF6.

To investigate the insulating state of the pressure-induced superconductor, beta-(meso-DMBEDT-TTF)2PF6, we have carried out X-ray analysis at 11.5 K. In an asymmetric unit, there exist two crystallographically independent donor molecules, caused by charge separation. In the column structure, the arrangement of the charge-rich (r) and -poor (p) donor molecules is as rrpprrpp, which affords "checkerboard"-type charge ordering.

Journal Article↗
PubMed2006

Hyalinizing clear cell carcinoma arising from the base of the tongue.

Hyalinizing clear cell carcinoma is a low-grade indolent and rare salivary gland tumor originally described by Milchgrub et al. in 1994. We herein report a case of this tumor of the base of the tongue. A 66-year-old Japanese woman presented with a large painless mass in the throat. Computed tomography and magnetic resonance imaging revealed a 40x30-mm well-defined ovoid tumor arising from the base of the tongue. She underwent tracheostomy followed by a resection of the tumor via the transmandibular approach combined with a right-sided supra-omohyoid neck dissection. Because the tumor invasion of the surrounding tissue was limited, the surgical defect at the base of the tongue was relatively small, and no reconstructive procedure needed to be performed. The tumor was histopathologically diagnosed as hyalinizing clear cell carcinoma of the minor salivary gland. Her postoperative clinical course was uneventful. No aspiration or difficulty upon deglutition was recognized when she started transoral ingestion on the eighth postoperative day. The patient is currently free from disease 21 months after surgery. The pathology, clinical characteristics, and treatment of hyalinizing clear cell carcinoma are bibliographically reviewed.

Adenocarcinoma, Clear Cell↗
PubMed2006

Functional inferior turbinosurgery (FITS) for the treatment of resistant chronic rhinitis.

CONCLUSIONS: Modified vidian neurectomy combined with inferior turbinoplasty provided an optimal surgical outcome as a treatment for intractable chronic rhinitis as evidenced by a relatively long-term follow-up. OBJECTIVE: The study was designed to determine the efficacy of submucosal reduction of the inferior turbinate and resection of the posterior nasal nerve for the treatment of resistant chronic rhinitis. PATIENTS AND METHODS: Fifty-six consecutive patients (37 males and 19 females; mean+/-SD age, 26+/-11 years) with resistant allergic rhinitis or nonallergic rhinitis with eosinophilia syndrome despite medical treatment. Symptomatic improvement including nasal obstruction, nasal discharge, sneezing, smell perception, and quality of life and objective evaluation of nasal airway resistance and nasal provocation test before and after surgery were investigated. RESULTS: The patients showed a remarkable improvement of > or = 80%, with the exception of two patients who had an approximately 50% reduction of the total symptomatic scores. Four of eight patients with anosmia subjectively improved whereas the other four patients felt unchanged. All patients who underwent rhinomanometry (n=15) and nasal provocation testing (n = 15) both before and after surgery showed a significant improvement. There were no intraoperative complications. Postoperative epistaxis occurred in one patient. One patient complained of a transient hypesthesia of the soft palate and dry eye. Nasal mucosal tears were observed in approximately 30% of the patients who otherwise showed no severe synechia or persistent crusting.

Adolescent↗
PubMed2006

Relationships among nasal obstruction, daytime sleepiness, and quality of life.

OBJECTIVES: There has been growing awareness that nasal obstruction may impair various daily and social activities. We performed a questionnaire survey on a working population to clarify the relationships among nasal obstruction, daytime sleepiness, and quality of life (QOL). METHODS: Seven thousand nine hundred eighty daytime workers were asked to complete questionnaires, and the data from 7,180 subjects without any missing answers were finally analyzed (90.0% of the total participants). The severity of nasal obstruction was graded into the following three categories: never/rarely, sometimes, and always/often. Daytime sleepiness and QOL were assessed by the Epworth Sleepiness Scale and the Medical Outcomes Study 36-Item Short-Form Health Survey, respectively. RESULTS: Younger subjects reported a higher degree of nasal obstruction. Subjects who reported a higher degree of nasal obstruction had higher daytime sleepiness and lower quality of life. Subjects with higher daytime sleepiness had lower quality of life. The degree of nasal obstruction was not associated with body mass index. CONCLUSIONS: Taking into account the impact of nasal airway resistance on sleep-disordered breathing, the present results suggest that chronic nasal obstruction impairs QOL, at least partially, through excessive daytime sleepiness possibly caused by sleep-disordered breathing. We stress that sufficient and appropriate rhinologic treatment may improve the quality of daily and social activities of individuals with sinonasal diseases.

Adult↗
PubMed2006

Novel missense mutation of the DNA topoisomerase I gene in SN-38-resistant DLD-1 cells.

Irinotecan hydrochloride, a camptothecin derivative, is one of the most effective drugs for colorectal cancer, and SN-38 is its main active metabolite. Development of resistance is a major obstacle to the clinical application of this drug. We established an SN-38-resistant subline from DLD-1 human colon cancer cells by continuous exposure to SN-38 and studied the mechanisms of resistance. The resistant subline (designated as DLDSNR6) had 10- to 100-fold higher resistance to camptothecin derivatives but showed no cross-resistance to doxorubicin, mitomycin C, and etoposide. DLDSNR6 cells carried a missense mutation in one allele of the DNA topoisomerase I gene that substituted glycine for serine at amino acid residue 365 accompanied by loss of the latter part of the remaining wild-type allele. Topoisomerase I expression was equal in DLDSNR6 and DLD-1 cells, but the nuclear extract of DLDSNR6 cells showed lower topoisomerase I catalytic activity. Moreover, exposure to camptothecin caused less accumulation of topoisomerase I-DNA complexes in DLDSNR6 cells than in DLD-1 cells. These findings suggest that the mutation interfered with both the catalytic activity of topoisomerase I and the stability of the ternary complex between topoisomerase I, DNA, and SN-38. This SN-38-resistant DLDSNR6 cell line may be useful for understanding the mechanisms of topoisomerase I function and drug-enzyme interactions.

Amino Acid Substitution↗
PubMed2006

Chemical genetic algorithms--evolutionary optimization of binary-to-real-value translation in genetic algorithms.

A chemical genetic algorithm (CGA) in which several types of molecules (information units) react with each other in a cell is proposed. Not only the information in DNA, but also smaller molecules responsible for the transcription and translation of DNA into amino acids, are adaptively changed during evolution, which optimizes the fundamental mapping from binary substrings in DNA ( genotype) to real values for a parameter set (phenotype). Through the struggle between cells containing a DNA unit and small molecular units, the codes (DNA) and the interpreter (the small molecular units) coevolve, and a specific output function, from which a cell's fitness is evaluated, is optimized. To demonstrate the effectiveness of the CGA, it is applied to a set of variable-separable and variable-inseparable problems, and it is shown that the CGA can robustly solve a wide range of optimization problems regardless of their fitness characteristics. To ascertain the optimization of the genotype-to-phenotype mapping by the CGA, we also conduct analytical experiments for some problems while observing the basin size of a global optimum solution in the binary genotype space. The results show that the CGA effectively augments the basin size, makes it easier for evolution to find a path to the global optimum solution, and enhances the GA's evolvability during evolution.

Algorithms↗
PubMed2006

Blockade of the renin-angiotensin system attenuates sarcolemma and sarcoplasmic reticulum remodeling in chronic diabetes.

Although the defects in the sarcolemma (SL) and sarcoplasmic reticulum (SR) membranes are known to be associated with cardiac dysfunction in chronic diabetes, very little information regarding the mechanisms of these membrane abnormalities is available in the literature. For this reason, rats were treated daily for 8 weeks with and without enalapril, an angiotensin-converting enzyme inhibitor, or losartan, an angiotensin receptor antagonist, 3 days after inducing diabetes with an injection of streptozocin. Treatment of diabetic animals with both enalapril and losartan attenuated alterations in cardiac function and the left ventricular redox potential without any changes in the increased plasma glucose or reduced plasma insulin levels. The SL Na+-K+ ATPase, Ca2+ pump, Na+-dependent Ca2+-uptake, Ca2+-channel density, and low-affinity Ca2+-binding activities were depressed whereas Ca2+ ecto-ATPase activity was increased in the diabetic heart. Furthermore, the SR Ca2+-release and Ca2+-pump activities in the diabetic hearts were decreased without any changes in the Mg2+-ATPase activity. These alterations in SL and SR membranes in diabetic animals were partly prevented by treatments with enalapril and losartan. The results suggest that the activation of the renin-angiotensin system plays an important role in diabetes-induced changes in SL and SR membranes as well as cardiac function.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2006

[Survey of nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae in infants at day care centers].

Infants at day care centers tend to contract repetitive upper respiratory infections and prolonged otitis media. The increase in antimicrobial-resistant bacteria, particularly in infants, has given rise to a stubborn therapeutic problem. We studied the nasopharyngeal carriage and drug resistance to Haemophilus influenzae (H. influenzae) and Streptococcus pneumoniae (S. pneumoniae), the most common pathogens of upper respiratory infections, in infants at day care centers. Nasopharyngeal cultures of infants between the ages of 0 and 6 years were conducted at two day care centers in July 2004 ("summer"; n=183), and in February 2005 ("winter"; n=182). Isolated H. influenzae and S. pneumoniae were subjected to antibiotic susceptibility tests by broth microdilution. We also conducted an otolaryngological examination and a survey on past and life histories. H. influenzae in summer (38.3%) increased significantly in winter (57.7%). Beta-lactamase-negative and positive ampicillin-resistant H. influenzae (BLNAR+ BLPAR) in summer decreased significantly in winter. S. pneumoniae did not differ in summer (42.1%) or in winter (43.4%). Penicillin-resistant and intermediate S. pneumoniae (PRSP+PISP) was 41.3% in summer and decreased significantly to 19.0% in winter. BLNAR + BLPAR and PRSP + PISP differed with the day care center. In otolaryngological examination, rhinosinusitis was commonest (28.4% in summer and 30.8% in winter), followed by allergic rhinitis (8.7% in summer and 6.0% in winter) and otitis media (8.2% in summer and 6.0% in winter). Tonsillitis was minor (0.5% in both seasons). Rhinosinusitis in winter was significantly higher in carriers of H. influenzae and/or S. pneumoniae than in non carriers (36.4% versus 16.0%). Breast-fed infants tended to have less otitis media than bottle-fed infants (38.2% versus 52.9%). H. influenzae and/or S. pneumoniae plateaued (75-80%) after 12 months in day care centers. These results suggest that infants attending day care centers are immediately colonized by H. influenzae and S. pneumoniae in the nasopharynx after entering the centers. Nasopharyngeal drug-resistant H. influenzae and S. pneumoniae varied during the seasons and between day care centers. Further prospective studies are needed to determine upper respiratory tract infection in infants at day care centers and to evaluate carriage, epidemiology, and the drug-resistance rates of these pathogens.

Age Factors↗
PubMed2006

[Clinical and MRI findings of patients with internuclear ophthalmoplegia].

Internuclear ophthalmoplegia (INO) is a distinctive ocular motor disorder resulting from dysfunction of the medial longitudinal fasciculus, which lies in the pontine tegmentum. We retrospectively analyzed clinical and magnetic resonance imaging (MRI) findings for four consecutive patients with internuclear ophthalmoplegia who were treated in our hospital. The causes of the disease were cerebral infarction in three cases and multiple sclerosis in one case. Vertigo and facial nerve palsy were associated in three cases and one case, respectively. MRI studies visualized an ischemic lesion in the responsible portion of the brainstem in one patient but failed to reveal responsible lesions in the other three patients. All the patients completely recovered in 1 to 22 days, with an average recovery period of 9.3 days. The etiology, diagnosis and management of INO were bibliographically reviewed.

Adolescent↗
PubMed2006

[Intraoperative brain surface blood flow monitoring using IRIS V thermographic imaging system in patients with Moyamoya disease].

Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving CBF. But little is known about the changes of intraoperative cerebral hemodynamics and its effect on postoperative neurological status including symptomatic cerebral hyperperfusion. To address this issue, we applied a novel infrared camera system (IRIS-V thermographic system) for real-time, visual monitoring of surface CBF during surgery in patients with moyamoya disease. Seven patients (8 sides, male:female= 3:4, 7-62 years old) with moyamoya disease were included in the study. After STA-MCA anastomosis, STA were occluded transiently and recanalized, and whole sequence was recorded by IRIS-V system. Correlation between clinical, radiological findings and infrared imaging were investigated. Patency of bypass was confirmed by this camera during surgery in all cases. The intraoperative imaging patterns were divided into two groups. Group A: Change of brain surface color (++) (3 cases). Group B: Change of brain surface color (-) (4 cases). Transient symptomatic hyperperfusion occurred in all patients in Group A, whereas all patients in Group B showed non-symptomatic transient focal hyperperfusion on SPECT. No patient suffered permanent neurological deterioration compared to preoperative status. Characteristic pattern of the intraoperative cerebral hemodynamics as delineated by IRIS-V could be the optimal predictor for postoperative transient symptomatic hyperperfusion after direct bypass in patients with moyamoya disease.

Adult↗
PubMed2005

Adenoviral infection of survivin antisense sensitizes prostate cancer cells to etoposide in vivo.

BACKGROUND: We aimed to investigate whether use of a survivin antisense fragment carried by an adenovirus vector (Ad.survivin-AS) could enhance the therapeutic efficacy of chemotherapy for androgen-independent prostate cancer. METHODS: We used Ad.survivin-AS to promote apoptosis through inhibition of survivin expression. Recombinant adenoviruses alone or in combination with chemotherapeutic agents were tested for anti-cancer activity both in vitro and in vivo. RESULTS: Infection with Ad.survivin-AS strongly inhibited survivin expression in a dose- and time-dependent manner, resulting in significant antitumor activity in vitro and in vivo. Downregulation of survivin expression potentiated induction of apoptosis by the chemotherapeutic agents docetaxel and etoposide in DU145 cells. In particular, the combination of etoposide and Ad.survivin-AS demonstrated dramatic growth inhibition with no tumor regrowth being observed during the experimental period. CONCLUSIONS: The prominent synergy of this combination may provide a basis for clinical application of Ad.survivin-AS as a chemosensitizer of etoposide.

Adenoviridae↗
PubMed2005

Pathological alterations of strial capillaries in dominant white spotting W/Wv mice.

Dominant white spotting W/W(v) and W(v)/W(v) mice are well-known mutants that lack strial intermediate cells in their cochlea and manifest hereditary sensorineural hearing loss. We recently reported marked thickening of and IgG deposition on the basement membrane of strial capillaries in W/W(v) mutant mice, similar to observations made in aged animals and in animals with autoimmune sensorineural hearing loss. The present study aimed to clarify the age-dependent changes in these pathological findings of strial capillaries in the W/W(v) mice. Male WBB6F1 +/+ and dominant white spotting W/W(v) mutant mice were sacrificed by transcardiac perfusion with paraformaldehyde solution. The cochlear ducts were isolated and subjected to light- and electron-microscopy, immunohistochemistry, immunoelectron microscopy. Alternatively, lanthanum chloride tracer examination in the isolated cochlear ducts was performed in order to compare the permeability of the strial capillaries between +/+ and W/W(v) mice. In the W/W(v) mice, thickening of and IgG deposition on the basement membrane of strial capillaries were observed as early as 1 week after birth and became more noticeable with age. Deposited IgG was preferentially localized to the thickened basement membrane and was also observed in partially the intercellular space between adjacent of endothelial cells. In addition, pinocytotic vesicles both in the apical and basal lesions of such cells also showed IgG deposition. Lanthanum chloride was retained along apical plasma membrane of the endothelial cells in the +/+ mice but penetrated through the endothelial layer in the W/W(v) mice. These results indicate that active transport via pinocytotic vesicles as well as increased permeability of strial capillaries in the W/W(v) mice occur in the early stage after birth, resulting in the morphological alterations in the strial capillaries of these mice.

Aging↗
PubMed2005

Effects of activation of central nervous histamine receptors in cardiovascular regulation; studies in H(1) and H(2) receptor gene knockout mice.

To elucidate the central roles of histamine receptors in cardiovascular regulatory system, systolic, mean, and diastolic blood pressures (BPs) and heart rate (HR) were examined in conscious H(1) receptor gene knockout (H(1)KO) mice, H(2) receptor gene knockout (H(2)KO) mice, H(1) and H(2) receptor gene double knockout (DKO) mice, and their respective control mice by the tail-cuff system. Histamine, histamine-trifluoromethyl-toluidine derivative (HTMT, an H(1) agonist), dimaprit (an H(2) agonist), and immepip (an H(3) agonist) were intrathecally administered to these KO mice and control mice. Basal BPs and HR were not different among these three KO mice and their control or wild-type mice. Intrathecal administration of histamine significantly increased BPs and decreased HR in control mice. The increases in BPs were produced by histamine in H(1)KO and H(2)KO mice and by HTMT and dimaprit in C57BL mice. The pressor responses by HTMT and dimaprit in C57BL mice were greater than those by histamine in H(1)KO and H(2)KO mice, although the same decreases in HR were induced by histamine in C57BL and H(1)KO mice and by dimaprit in C57BL mice. The selective stimulation of H(3) receptors by immepip produced a consistent decrease in BPs in control mice. These results obtained with the exogenous selective agonists of three histamine receptors suggest that the pressor responses to histamine are mediated through the stimulation of both H(1) and H(2) receptors, whereas the atropine-sensitive decrease in heart rate is mainly due to H(2) receptors which activate the vagal output to the heart.

Animals↗