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Biomedical subjects

Masanobu Uchiyama

Publications and source records attributed to Masanobu Uchiyama.

At least 19 recordsLinked to original sources
PubMed2026

[A Case of Stage Ⅳ Lung Adenocarcinoma with Bilateral Breast Metastases Mimicking Inflammatory Breast Cancer].

Breast metastases from primary lung cancers with inflammatory breast cancer (IBC)-like features are rare. Here, we report a patient with bilateral breast metastases from an advanced lung adenocarcinoma that mimicked IBC. A 67-year-old woman was diagnosed with right middle lobe lung adenocarcinoma with pleural and peritoneal dissemination (cT2aN2M1c, cStage ⅣB) and received systemic therapy. Twenty-nine months later, skin erythema and edema appeared in both breasts, suggesting bilateral IBC. Core needle biopsies of both breasts revealed atypical carcinomas without intraductal or lobular in situ components. Immunohistochemistry showed thyroid transcription factor-1 and Napsin A positivity and GATA3 negativity, supporting the diagnosis of metastatic lung adenocarcinoma of the breasts. Comprehensive genomic profiling of the breast specimen revealed an EGFR exon 19 deletion, and osimertinib achieved disease control within 1 year. This report highlights a diagnostic pitfall in which lung adenocarcinoma metastasis to the breast mimics IBC and underscores the importance of biopsy, an appropriate immunohistochemical panel, and molecular testing to establish a correct diagnosis and guide optimal systemic therapy.

Humans↗
PubMed2025

Vinigrol Tricyclic Scaffold Biosynthesis Employs an Atypical Terpene Cyclase and a Multipotent Cyclization Cascade.

Vinigrol (1) is a fungal diterpenoid consisting of a decahydro-1,5-butanonaphthalene ring system with no analogs in nature. Despite immense efforts in synthetic studies, the vinigrol biosynthesis pathway remains largely unknown. Herein, we identified a biosynthetic gene cluster for 1 and fully elucidated the biosynthetic pathway. By employing an AlphaFold-generated model structure, we identified the possible catalytic residues of the noncanonical terpene cyclase and analyzed their function by site-directed mutagenesis. We found that the G340A mutation opened a cryptic pathway for an unprecedented tetracyclic diterpene, defined here as virgarene. Retro-biosynthetic theoretical analysis provided a solid foundation for the complex cyclization pathway for the vinigrol scaffold, its chemical transformation to a structurally distinct bonnadiene, and redirection of the enzymatic cyclization cascade to virgarene. Close inspection of the terpene cyclization pathway via integrated experimental and theoretical approaches would allow efficient exploration of novel terpenoid chemistries.

Cyclization↗
PubMed2006

Regiocontrolled intramolecular cyclizations of carboxylic acids to carbon-carbon triple bonds promoted by acid or base catalyst.

We systematically investigated, for the first time, the relationship between regioselectivity and acid/base effects in the cyclization reactions between carboxylic acids and carbon-carbon triple bonds. We found novel acid- and base-promoted cyclizations to selectively give isocoumarin or pyran-2(2H)-one and phthalide or furan-2(5H)-one skeletons, respectively, and established a catalytic version of regioselective heterocyclic ring synthesis. Density functional theory calculations and application to a short route to thunberginol A were also described. [reaction: see text].

Anti-Bacterial Agents↗
PubMed2006

Spontaneous resolution of aromatic sulfonamides: effective screening method and discrimination of absolute structure.

An effective screening method combining parallel synthesis and solid-state CD measurements was established to identify achiral aromatic sulfonamides that show spontaneous resolution with rapidity. We found that 4 of the 12 achiral sulfonamides crystallized as chiral crystals through this method. The chirality of each sulfonamide was discriminated by solid-state CD spectra and Flack parameter in an X-ray analysis. Correspondence between the observed Cotton effect and the absolute configuration could be confirmed by time-dependent DFT calculations. [structure: see text]

Chemistry, Organic↗
PubMed2006

Structure and reaction pathway of TMP-Zincate: amido base or alkyl base?

The novel directed ortho metalation (DoM) reagents for functionalized aromatic rings, TMP-Zn-ates (R2Zn(TMP)Li (R = Me, 1; tBu, 2)), have been reported to be synthetically useful for the chemo- and regioselective construction of multi-functionalized aromatic compounds. Here, we present the first comprehensive structural and mechanistic investigation by means of X-ray, NMR, and DFT studies on the DoM reaction employing our original TMP-Zn-ate base. The structures of TMP-Zn-ates in solution and in the solid state were determined. The DFT study strongly suggested that the deprotonation involving the TMP ligand on the TMP-Zn-ate is kinetically more favorable than that involving the alkyl ligand, and this view was supported by monitoring of the 13C NMR spectrum of the reaction mixture.

Crystallography, X-Ray↗
PubMed2006

Toward a protecting-group-free halogen-metal exchange reaction: practical, chemoselective metalation of functionalized aromatic halides using dianion-type zincate, tBu4ZnLi2.

A versatile preparation method for aromatic zincate compounds through a halogen-zinc exchange reaction using dilithium tetra-tert-butylzincate (tBu4ZnLi2) has been developed. This reagent permits efficient preparation of highly functionalized aromatic zincates, particularly, those with electrophilic functional groups, such as ester, amide, alcohol, and phenol. Halogen-zinc exchange reactions followed by electrophilic trapping (with allyl bromide or benzaldehyde) proved to be a powerful tool for C-C bond formation on functionalized aromatic rings. The functionalized aromatic zincate intermediate was also found to undergo copper- and palladium-catalyzed C-C bond-forming reactions with good yields and high chemoselectivity.

Anions↗
PubMed2006

The influence of gender, athletic events, and athletic experience on the subjective dominant hand and the determination of the dominant hand based on the laterality quotient (LQ) and the validity of the LQ.

This study aimed to reveal the influence of gender, athletic events and athletic experience on the subjective dominant hand and the dominant hand based on the laterality quotient (LQ). It also aimed to examine the validity of the Edinburgh Inventory (Oldfield, 1971). Males and females (n=3,726) living in 7 prefectures in Japan (age: 16-45 yrs) participated in this survey. Analysis was performed on 3,557 separate datasets with high reliability. The reliability of the survey was examined using a test-retest method consisting of 100 people selected randomly from all participants. All participants provided the same answers for each question. The influence of gender, event and experience was examined for the subjective and LQ-based dominant hands. In addition, concordance rates of the subjective dominant hand and the LQ-based dominant hand and both dominant hands were examined. Differences of concordance rates between hands used in the 10 movement questions of the Inventory and the subjective dominant hand were tested using the chi(2) test. The frequency differences among items were tested using Ryan's method (multiple comparisons). Significant gender differences were found between rates of the LQ-based dominant hand (males: 94.4%; females: 96.6%) and the subjective dominant hand (males: 91.6%; females: 94.0%), but the degree was only 2.0-4.0%. Insignificant differences were found among athletic events, two groups of different athletic experience, and gender according to each athletic event. The subjective dominant hand almost always agreed with the LQ-based dominant hand (complete concordance rate=0.96, kappa=0.67). Of the 10 question items, inexperienced answers were found only in the item "Knife (without fork)". The "Toothbrush", "Broom (upper hand)", and "Opening box (lid)" items had significantly lower correspondence with the subjective dominant hand (79.7-87.0%) than the other items (92.1-95.7%). In conclusion, athletic experience appears to have little influence on handedness, although there is a slight gender difference. The subjective dominant hand almost always agrees with the dominant hand based on the Inventory. A more efficient handedness inventory may be constructed by excluding the above 4 items.

Adolescent↗
PubMed2006

An examination of practice and laterality effects on the Purdue Pegboard and Moving Beans with Tweezers.

The purpose of this study was to examine the relation of practice or learning and laterality on the Purdue Pegboard and the Moving Beans with Tweezers test. The subjects were 30 right-handed, healthy young male adults (age: M = 21.1, SD = 1.9 yr.). The subjects performed both tests five times with each hand. A two-way analysis of variance (hand x trial) for scores on the Purdue Pegboard showed that Trial 1 had a significantly lower mean than Trials 4 and 5 with the dominant hand, and scores on Trials 1 and 3 were lower than that on Trial 5 for the nondominant hand. For the Moving Beans with Tweezers test, Trial 1 had a significantly lower score than Trial 5 with the nondominant hand. The dominant hand produced significantly higher values on all trials of both tests. Intraclass correlation coefficients of Trials 2 and 3 were high, and means were significantly higher for the dominant hand. A correlation between other tests was not high (r = .37-.46) for both hands. All correlations among five trials on both tests were significant and high (Purdue Pegboard-Dominant: average r =.72, [r] = .60-.80, Purdue Pegboard-Nondominant: average r = .59, [r] = .43-.76), (Moving Beans-Dominant: average r = .74, [r] = .57-.81, Moving Beans-Nondominant: average r =.71, [r] = .55-.87). Correlations among five trials for the ratio of dominant:nondominant hand on both tests were significant and moderate (Moving Beans: average r = .28, [r] = .08-.57, Purdue Pegboard: average r = .41, [r] = .19.56). Performance with the dominant hand is superior to that of the nondominant hand on both tests. Practice effects are found for both tests across five trials. The Moving Beans with Tweezers test also showed laterality of practice effects. The two tests may measure different abilities.

Adult↗
PubMed2006

Influence of differences of visual acuity in various visual field conditions on spectral characteristics of the center of pressure sway.

This study examined the influence of visual acuity and visual field on the spectral characteristics of the center of pressure during standing. 17 men and 20 women participated in High and Low visual acuity groups. Both groups underwent center of pressure measurements under three visual field conditions: No vision: subjects were given no visual information, Central vision: they were given only central visual field information, and Full vision: they were given full visual information. To assess the spectral characteristics of center of pressure, mean power frequency and frequency of maximal power were calculated from medial-lateral and anterior-posterior center of pressure directions. The Friedman test and Scheffé pairwise comparison tests showed that frequency of maximal power was higher in the No vision than in the Central and Full vision conditions in the High visual acuity group. In conclusion, people with high visual acuity are more susceptible to visual field conditions than those with low visual acuity. It is suggested that postural control characteristics differ with visual acuity or resolution in the central visual field.

Adult↗
PubMed2005

Cp2TiCl2-catalyzed regio- and chemoselective one-step synthesis of gamma-substituted allylsilanes from terminal alkenes using dianion-type zincate (SiSiNOL-Zn-ate).

A regio-/chemoselective silylation reaction of various functionalized terminal alkenes in the presence of titanocene dichloride, based on a newly designed dianion-type zincate, was developed. The present silylation of terminal alkenes is a powerful tool for the one-pot generation of regiocontrolled functionalized allysilanes, which are available for various transformation reactions, such as hydroxyalkylation, epoxidation, and hydroboration.

Alkenes↗
PubMed2005

Inductive effect-assisted chain-growth polycondensation. synthetic development from para- to meta-substituted aromatic polyamides with low polydispersities.

The polycondensation of m-(octylamino)benzoic acid esters (1) with base was investigated in order to extend the synthesis of well-defined condensation polymers from para-substituted polymers to meta-substituted ones. We expected that the aminyl anion of 2 would deactivate the ester moiety at the meta position of 2 owing to the strong inductive effect of the anion, resulting in, not self-polycondensation, but chain-growth polycondensation. The methyl ester monomer 1a polymerized with lithium hexamethyldisilazide (LiHMDS) in the presence of phenyl benzoate (3a) as an initiator at 0 degrees C to afford a polymer with a low polydispersity, but the product contained a small amount of self-condensation polymer. On the other hand, the polymerization of the ethyl ester monomer (1b) with phenyl 4-methylbenzoate (3b) proceeded through chain polymerization without self-polycondensation. The Mn values of the polymers increased linearly in proportion to the [1b]0/[3b]0 ratio, and the Mw/Mn ratios remained narrow over the entire [1b]0/[3b]0 range. Furthermore, a block copolymer of N-alkylated poly(m-benzamide) and poly(p-benzamide) with a low polydispersity was synthesized by the monomer addition method under this polymerization condition.

Journal Article↗
PubMed2005

Helical structures of N-alkylated poly(p-benzamide)s.

Poly(p-benzamide)s 1 bearing a chiral side chain on the nitrogen atom were synthesized by chain-growth polycondensation methodology. The polyamides exhibited well-defined molecular weights with narrow polydispersities. Solutions of the polyamides in several organic solvents (CH(3)CN, CHCl(3), and CH(3)OH) showed dispersion type CD signals characteristic of coupled-oscillator and much larger as compared with the corresponding monomer. The CD signals were dependent on the temperature and molecular weight of the polyamides but independent of the solvent, as far as examined. An exciton model analysis of the absorption and CD spectra provided a clear-cut picture for the secondary structure of these polyamides in solution that the N-alkylated poly(p-benzamide)s possess a right-handed helical conformation ((P)-helix). In the solid states, the results of X-ray crystallographic analysis of 4-(methylamino)benzoic acid oligomers substantiated that they have a helical conformation with three monomer units per turn.

Journal Article↗
PubMed2005

Definitive assignments of the visible-near-IR bands of porphyrin-naphthalocyanine rare-earth sandwich double- and triple-decker compounds by magnetic circular dichroism spectroscopy.

A series of heteroleptic rare-earth sandwich complexes [M(Nc)(OEP)] (M = La, Nd, Eu, Dy, and Lu; Nc = 2,3-naphthalocyaninate; OEP = octaethylporphyrinate) have been investigated by electronic absorption and magnetic circular dichroism (MCD) spectroscopy. The electronic absorption spectra of the neutral forms showed two characteristic transitions (bands I and II) in the near-IR region, both of which were systematically shifted depending on the size of their central metal. In the MCD spectra, a relatively intense Faraday A term and a significantly weak Faraday B term have been observed corresponding to bands II and I, respectively. The spectral features were successfully interpreted using a simple MO model by considering the relevant interactions of Gouterman's four orbitals of the constituent chromophores. The model succeeded in assigning the MCD spectra of the related compounds, the oxidized and reduced forms of the dimer ([M(Nc)(OEP)]+ and [M(Nc)(OEP)]-), and neutral forms of the triple-decker compounds (M2(Nc)(OEP)2, M = Nd, Eu). DFT calculations of the dimers supported the validity of this model.

Journal Article↗
PubMed2005

Magnetic circular dichroism study of directly fused porphyrins.

The magnetic circular dichroism (MCD) spectra of doubly and triply linked fused bisporphyrins (2MD and 2MT, M = Ni, Zn, Cu, Pd, and H2) and triply linked higher oligomers (3ZnT and 4ZnT) have been measured, and their Q-bands assigned based on the results of INDO/s calculations. In contrast to the Faraday A term observed for the Q(0,0) band of Ni(II) tetraphenylporphyrin, a single positive Faraday B term was observed for the lowest energy transition of the fused systems. The calculations indicated that the molecular orbitals (MOs) of the directly fused porphyrins consist of linear combinations of the constituent monomeric MOs, and that the effect of lowering the symmetry is always larger on the lowest unoccupied molecular orbital (LUMO) than on the highest occupied molecular orbital (HOMO). On the basis of Michl's perimeter model, these features can be correlated with the observed positive MCD signs in the near infrared region. A weak absorption band at 600-700 nm for the fused dimers can be assigned to a short-axis polarized Q transition.

Journal Article↗
PubMed2005

Effect of Japanese sitting style (seiza) on the center of foot pressure after standing.

Seiza is one of the most commonly used sitting postures in various enrichment lessons of Japanese origin. It is reported that Seiza with large knee flexion produces harmful effects on the cartilage of knee joints and hemodynamics of the lower legs. This study aimed at examining the influence of Seiza on tissue oxygenation kinetics of the lower limbs, plantar somatic and cutaneous sensation, and the center of foot pressure (COP) sway using 10 young adults. COP sway was measured for 1 min just after sitting on a chair for 10 min (pre-test), after 30-min Seiza (post-test 1), and 5 min after Seiza (post-test 2). To evaluate the COP sway, we used 4 body sway factors; unit time sway factor (F1), front-back sway factor (F2), left-right sway factor (F3) and high frequency band power spectrum factor (F4). Physiological parameters (i.e., tissue oxygenation kinetics in the lower legs and sensation on the sole) were measured during 30-min Seiza (continuously on tissue oxygenation, and at 1 min intervals on sensation), and for 1 min just before each COP test (pre-test, post-test 1 and 2). Oxygenated hemoglobin/myoglobin (Hb/Mb) concentration decreased markedly and deoxygenated Hb/Mb concentration increased markedly, resulting in reaching a plateau state at around 7 min. Tissue Hb/Mb index changed little during Seiza. Proprioceptive perception thresholds increased rapidly about 17 min after Starting Seiza. Means of 3 COP sway factors of F1, F2 and F4 were significantly higher in post-test 1 than in pre-test and post-test 2. In conclusion, a marked decrease in tissue oxygen concentration of the lower legs within 4-5 min, and an increase of proprioceptive perception thresholds in the sole at about 17 min are induced by Seiza. Although wiggle and quick body sway in the antero-posterior axis increases markedly in an upright posture just after maintaining Seiza for 30 min, sway recovers after sitting on a chair for 5 min.

Adult↗
PubMed2005

The practice effect and its difference of the pursuit rotor test with the dominant and non-dominant hands.

The purpose of this study was to examine the practice effect and what difference it makes in the pursuit rotor test for the dominant and non-dominant hands in 30 right-handed Japanese male adults aged 18 to 23 years (Age 20.8+/-1.4 yrs). The subjects performed the pursuit rotor test for 1 min in 20 trials with a 1-min interval alternately using the dominant and non-dominant hands. After continuing for 10 trials, a 5-min rest was taken. The measurement order was randomly assigned. Contact time of a steel pen and a target was measured in units of 1/10 sec. The measurements showed a constant increasing tendency at every trial until the 6th trial in both hands. Significant linear regressions were identified, but the increase-rate of the dominant hand was significantly larger. Individual differences showed a decreasing tendency at every trial in the dominant hand, but in the non-dominant hand it increased until the 4th trial then decreased. The relationships between measurements of the 1st and 10th trials in both hands and both hands in the 1st or 10th trial were not high. The performance of the pursuit rotor test improves at every trial in both hands, but the improvement rate decreases after the 7th trial. The improvement rate of the dominant hand is high. The change in individual differences differs in both hands and the relationship between the measurements is not high. It can be judged that the practice effect of the pursuit rotor test differs in the dominant and non-dominant hands.

Adolescent↗