Efficient total syntheses of natural pterin glycosides: limipterin and tepidopterin

The key, versatile precursors N-2-(N,N-dimethylaminomethylene)-1'-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]biopterin (29a) and its ciliapterin analog (29b) were prepared, respectively, from D-xylose (in 14 steps) and L-xylose (in 11 steps). Treatment of 29a and 29b with 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-beta-D-glucopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups, led to the first selective syntheses of limipterin (3) and tepidopterin (5), respectively

First Synthesis of Biopterin α-D-Glucoside

A novel glycosyl donor, 4,6-di-O-acetyl-2,3-di-O-(4-methoxy-benzyl)-α-D-glucopyranosy bromide (15) was efficiently prepared from D-glucose in 8 steps. The first synthesis of 2’-O-(α-D-glucopyranosyl)biopterin (2) was achieved by treatment of the key precursor, N(2)-(N,N-dimethylamino- methylene)-1’-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]biopterin (6) with 15 in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups

An Efficient Synthetic Route for a Versatile Ciliapterin Derivative and the First Ciliapterin D-Mannoside Synthesis

The key precursor, N(2)-(N,N-dimethylaminomethylene)-1’-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]ciliapterin (15) was efficiently prepared from D-xylose via an improved route. The first synthesis of 2’-O-(α-D-mannopyranosyl)ciliapterin (2c) was achieved by treatment of 15 with 2,3,4,6-tetra-O-benzoyl-α-D-mannnopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the protecting groups

Synthesis of 6-Hydroxymethylpterin α- and β-D-Glucosides

The key precursor, N(2)-(N,N-dimethylaminomethylene)-6-hydroxymethyl-3-[2-(4-nitrophenyl)ethyl]pterin (11) was efficiently prepared from 2,5,6-triamino-4-hydroxypyrimidine (8) in 5 steps. The first, unequivocal synthesis of 6-hydroxymethylpterin α-D-glucoside (6a) was achieved by treatment of 11 with 4,6-di-O-acetyl-2,3-di-O-(4-methoxybenzyl)-α-D-glucopyranosyl bromide (16) in the presence of tetraethylammonium bromide and N-ethyldiisopropylamine, followed by removal of the protecting groups, while 6-hydroxymethylpterin β-D-glucoside (6b) was prepared by means of selective glycosylation of 11 with 2,3,4,6-tetra-O-benzoyl-α-D-glucopyranosyl bromide (12) in the presence of silver triflate and tetramethylurea

The impact of apartment vacancies on nearby housing rents over multiple time periods: application of smart meter data

[Purpose] This study aims to explore the spatial externalities of apartment vacancy rates on housing rent by considering multiple vacancy durations. [Design/methodology/approach] This research uses smart meter data to measure unobservable vacant houses. This study made a significant contribution by applying building-level smart meter data to housing market analysis. It examined whether vacancy duration significantly affected apartment rent and whether the relationship between apartment rent and vacancy rate differed depending on the level of housing rent. [Findings] The primary finding indicates that there is a significant negative correlation between apartment rent and vacancy duration. Considering the spatial externalities of apartment vacancy rates, the apartment vacancy rates of surrounding buildings did not show any statistical significance. Moreover, quantile regression results indicate that although the bottom 10% of apartment rent levels showed a negative correlation with all vacancy durations, the top 10% showed no statistical significance related to vacancies. [Practical implications] This study measures the extent of spatial externalities that can differentiate taxation based on housing vacancies. [Originality/value] The findings indicate that landlords have asymmetric information about their buildings compared with the surrounding buildings, and the extent to which price adjusts for long-term vacancies differs depending on the level of apartment rent

Nasopharyngeal carcinoma presenting with rapidly progressive severe visual disturbance: a case report

INTRODUCTION: Nasopharyngeal carcinoma is one of the most difficult tumors to diagnose correctly at the initial phase because of the occasional lack of nasal symptoms. The perineural spread of the trigeminal nerve is one of the most common and important routes in the intracranial paracavernous extension of nasopharyngeal carcinoma, but visual loss is very rare. CASE PRESENTATION: We report the case of a 54-year-old Japanese man with nasopharyngeal carcinoma, who presented with rapid and severe disturbance of left monocular visual acuity and eye movement with a 10-month history of ipsilateral otitis media and facial pain. Magnetic resonance imaging revealed a lesion in the left fossa of Rosenmüller, pterygopalatine fossa, sphenoid and ethmoid sinus, and the left cavernous sinus extending to the orbital apex through the superior orbital fissure. The histopathological diagnosis was nonkeratinizing undifferentiated nasopharyngeal carcinoma. Epstein–Barr virus was detected by in situ hybridization. Although focal radiotherapy induced remarkable tumor shrinkage and relieved ocular motor disturbance and facial pain, his visual acuity did not improve. CONCLUSION: The awareness of cranial nerves in addition to intracranial and orbital apex involvement, as in this case, is important for appropriate diagnosis and treatment planning of nasopharyngeal carcinoma

Nitric Oxide Regulates Growth Factor Signaling in Pancreatic Cancer Cells

Non

Synthetic studies on pterin glycosides: the first synthesis of 2′-O-(α-d-glucopyranosyl)biopterin

L-Rhamnose was led, in a 14-step-sequence, to N2-(N,N-dimethylaminomethylene)-1′-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]biopterin (23), an appropriately protected precursor for 2′-O-glycosylation, while 4,6-di-O-acetyl-2,3-di-O-(4-methoxybenzyl)-α-d-glucopyranosyl bromide (32), a novel glycosyl donor, was efficiently prepared from d-glucose in 8 steps. The first synthesis of 2′-O-(α-d-glucopyranosyl)biopterin (2a) was achieved by treatment of the key intermediate 23 with 32 in the presence of silver triflate and tetramethylurea, followed by successive removal of the protecting groups

<原著>副腎腫瘤の臨床的検討

We reviewed the records of 13 patients with adrenal masses operated on over a ten-year period to clarify clinical characteristics of adrenal tumors. Tumors were found incidentally in seven of nine patients with primary adrenal tumors (78%); however, three of these seven patients (43%) proved to have shown symptoms related to adrenal hyperfunction when re-e、raluated. Other adrenal tumors (metastatic in three patients and inflammatory in one) were found without any symptoms referable to the tumors. In nine of 13 patients (69%), tumors were discovered by computerized tomography (CT). All patients with primary tumors have been gotten free of disease postoperatively. In contrast, although all three patients with metastatic adrenal tumors underwent resection of all known disease tissue, they died of the recurrence of malignancies within 10 months. This study suggests that a number of functional adrenal tumors are possibly left undiagnosed until found incidentally, and that CT is the most powerful tool to detect adrenal tumors. Our data did not support surgical intervention in cases of metastatic adrenal tumors.副腎腫瘤の臨床的特徴を明らかにするために過去10年間に当科で手術された13例を検討した. 原発性腫瘍9例中2例は臨床症状より原発性アルドステロン症を疑われ副腎腫瘍を発見されているが, 残りの7例(78%)は偶然腫瘍が発見された, いわゆる incidentaloma であった. しかしながら, retrospective にみるとこの7例中3例(43%)で副腎機能亢進によると考えられる症状を呈していた. 転移性腫瘍3例, histoplasma による肉芽腫1例は全て無症状であった. 13例中9例(69%)はCTにより, 2例は超音波, 1例は血管造影, 1例は scintigraphy によりそれぞれ病変を発見され, CT で副腎腫瘤を指摘できなかったのは1例のみであった. 13例中11例は経腹的に, 2例 は開胸開腹で手術されたが, 術後合併症は1例に創感染を認めたのみであった. 原発性腫瘍例は全例術後再発を認めていないが, 転移性腫瘍の3例は全例, 術後10ヶ月以内に再発死した. 以上の結果は機能性副腎腫瘍でも偶然発見されるまで診断されない場合が多いことを示唆しており, 臨床症状を注意深く検討し常に副腎腫瘍の可能性を考慮にいれることが肝要であると考えられる. また, 今回の結果より CT が副腎腫瘤の診断において重要な位置を占めるものと考えられた. なお, 転移性副腎腫瘍に対する手術療法は今回の検討ではそれを積極的に支持する結果は得られず, 今後さらに検討を要する問題と思われる