Clinical features of ocular sarcoidosis: severe, refractory, and prolonged inflammation.

PURPOSE: To clarify the proportion of ocular sarcoidosis with severe, refractory, and prolonged inflammation and their association with ocular complications and visual prognosis. STUDY DESIGN: Multicenter, retrospective, longitudinal cohort study. METHODS: Three hundred and twenty-three eyes of 164 patients (45 men; 119 women) with ocular sarcoidosis who visited Hokkaido University Hospital and Yokohama City University Hospital from 2010 to 2015. We newly defined severe, refractory, and prolonged inflammation in ocular sarcoidosis, and investigated their proportions, ocular complications and final visual acuity from medical records of our sarcoidosis patients. RESULTS: The eyes with severe inflammation numbered 72/323 (22.3%), with refractory inflammation, 80/323 (24.8%), and with prolonged inflammation, 91/323 (28.2%). The number of eyes having neither severe, refractory, nor prolonged inflammation (defined as none) was 114/323 (35.3%). The numbers of eyes that reached irreversible visual dysfunction were 6/72 (8.3%) of those with severe inflammation, 10/80 (12.5%) with refractory inflammation, 12/91 (13.2%) with prolonged inflammation, and 4/114 (6.2%) with none. As complications, cataract (62.2%), glaucoma (28.5%), epiretinal membrane (24.1%), cystoid macular edema (22.6%), vitreous hemorrhage (2.8%), choroidal atrophy (2.5%), macular degeneration (1.2%), macular hole (0.9%) and retinal detachment (0.3%) were identified. Among them, secondary glaucoma (16 eyes) and macular degeneration (4 eyes) were major complications related to irreversible visual dysfunction. CONCLUSIONS: Although most of the patients with ocular sarcoidosis had a relatively good visual prognosis, some developed severe, refractory, and/or prolonged inflammation related to the development of ocular complications, that resulted in poor visual prognosis.

An open-label, prospective, single-arm study of switching from infliximab to cyclosporine for refractory uveitis in patients with Behçet's disease in long-term remission.

PURPOSE: Although infliximab (IFX) decreases the risk of blindness due to refractory uveitis in patients with Behçet's disease (BD), there are no standard criteria for IFX switching or withdrawal. To evaluate the effect of IFX switching in patients with BD in long-term remission, a prospective, single-arm intervention trial was conducted, switching from IFX to cyclosporine A (CYA). STUDY DESIGN: A prospective open-label study. METHODS: Eligible patients met the following criteria: administration of IFX without concomitant immunosuppressants for more than 5 years with no episodes of ocular attacks, no retinal vasculitis on fluorescein fundus angiography, negative C-reactive protein in serum, and no extraocular lesions at the time of IFX withdrawal. CYA 5 mg/kg/day was administered from 6 weeks after IFX withdrawal. The primary outcome was the rate of readministration of tumor necrosis factor inhibitors at 1 year after IFX withdrawal. RESULTS: Three of 45 BD patients treated with IFX for refractory uveitis were included in the study. At 1 year after withdrawal of IFX, no patient had experienced any ocular attacks or needed readministation of IFX. However, extraocular lesions, such as recurrent oral ulcers, folliculitis, and recurrent fevers, occurred in all patients. Liver or renal dysfunction, which may have been caused by CYA, was also observed in all patients. CONCLUSIONS: Although no ocular attacks were observed for at least 1 year after IFX withdrawal, this prospective study indicates that IFX withdrawal should be considered carefully, even for patients in long term remission of ocular and extraocular lesions.

Asymmetric synthesis of tetrahydroisoquinolines by enzymatic Pictet-Spengler reaction.

Norcoclaurine synthase (NCS) catalyzes the stereoselective Pictet-Spengler reaction between dopamine and 4-hydroxyphenylacetaldehyde as the first step of benzylisoquinoline alkaloid synthesis in plants. Recent studies suggested that NCS shows relatively relaxed substrate specificity toward aldehydes, and thus, the enzyme can serve as a tool to synthesize unnatural, optically active tetrahydroisoquinolines. In this study, using an N-terminally truncated NCS from Coptis japonica expressed in Escherichia coli, we examined the aldehyde substrate specificity of the enzyme. Herein, we demonstrate the versatility of the enzyme by synthesizing 6,7-dihydroxy-1-phenethyl-1,2,3,4-tetrahydroisoquinoline and 6,7-dihydroxy-1-propyl-1,2,3,4-tetrahydroisoquinoline in molar yields of 86.0 and 99.6% and in enantiomer excess of 95.3 and 98.0%, respectively. The results revealed the enzyme is a promising catalyst that functions to stereoselectively produce various 1-substituted-1,2,3,4-tetrahydroisoquinolines.

Efficient synthesis of (R)-3-hydroxypentanenitrile in high enantiomeric excess by enzymatic reduction of 3-oxopentanenitrile.

(R)-3-Hydroxypentanenitrile (HPN) is an important intermediate in the synthesis of an immunosuppressive inosine 5'-monophosphate dehydrogenase inhibitor. An efficient enzymatic procedure for the synthesis of (R)-HPN with over 99 % enantiomeric excess using a novel acetoacetyl-CoA reductase (AdKR) from Achromobacter denitrificans was successfully established. Many microorganisms are known to reduce 3-oxopentannitrile (KPN) to (R)-HPN. An enzyme from A. denitrificans partially purified using ion exchange chromatography reduced KPN to (R)-HPN with high enantioselectivity. The AdKR gene was cloned and sequenced and found to comprise 738 bp and encode a polypeptide of 26,399 Da. The deduced amino acid sequence showed a high degree of similarity to those of other putative acetoacetyl-CoA reductases and putative 3-ketoacyl-ACP reductases. The AdKR gene was singly expressed and coexpressed together with a glucose dehydrogenase (GDH) as a coenzyme regenerator in Escherichia coli under the control of the lac promoter. (R)-HPN was synthesized with over 99 % e.e. using a cell-free extract of recombinant E. coli cells coexpressing AdKR and GDH.

Efficient preparation of (R)-3-hydroxypentanenitrile with high enantiomeric excess by enzymatic reduction with subsequent enhancement of the optical purity by lipase-catalyzed ester hydrolysis.

An efficient chemo-enzymatic procedure for the synthesis of (R)-3-hydroxypentanenitrile (1) with over 99% enantiomeric excess using two enzymatic reactions was successfully established. Initial enantioselective enzymatic reduction of 3-oxopentanenitrile with reductase S1 gave (R)-1 with an 81.5% ee which was then converted to (R)-1-(cyanomethyl) propyl n-butyrate (3b). Subsequent lipase-catalyzed enantioselective hydrolysis of 3b gave (R)-1 in a high yield with over 99% ee.

Purification and characterization of a novel (S)-enantioselective transaminase from Pseudomonas fluorescens KNK08-18 for the synthesis of optically active amines.

Pseudomonas fluorescens KNK08-18, showing (S)-selective transaminase activity, was isolated from soil by an enrichment culture method using (S)-7-methoxy-2-aminotetraline as the main nitrogen source. A transaminase was purified from the strain to homogeneity in seven steps. The relative mass of the enzyme was estimated to be 53 kDa on SDS-polyacrylamide gel electrophoresis and 120 kDa by gel filtration, suggesting a homodimeric structure. The optimal pH and temperature for enzyme activity were about 8.0-8.5 and 40 °C. The purified enzyme produced (S)-7-methoxy-2-aminotetraline, (S)-SMA, from 7-methoxy-2-tetralone (SMT) with high enantioselectivity. Although (S)-1-phenylethylamine was the best amino donor, ß-alanine and 4-aminobutyric acid, which are good substrates for typical ω-amino acid transaminase (EC 2.6.1.18) and GABA transaminase (2.6.1.19), were not reacted. It aminated a broad range of carbonyl compounds containing aromatic, non-aromatic, and acidic and non-acidic substrates.

Cloning and overexpression of an NADH-dependent alcohol dehydrogenase gene from Candida maris involved in (R)-selective reduction of 5-acetylfuro[2,3-c]pyridine.

5-((R)-1-Hydroxyethyl)-furo[2,3-c]pyridine ((R)-FPH) is a useful chiral building block in the synthesis of pharmaceuticals. An NADH-dependent alcohol dehydrogenase (AFPDH) isolated from Candida maris catalyzed the reduction of 5-acetylfuro[2,3-c]pyridine (AFP) to (R)-FPH with 100% enantiomeric excess. The gene encoding AFPDH was cloned and sequenced. The AFPDH gene comprises 762 bp and encodes a polypeptide of 27,230 Da. The deduced amino acid sequence showed a high degree of similarity to those of other members of the short-chain alcohol dehydrogenase superfamily. The AFPDH gene was overexpressed in Escherichia coli under the control of the lac promoter. One L of the cultured broth of an E. coli transformant coexpressing AFPDH and the glucose dehydrogenase (GDH) gene reduced 250 g of AFP to (R)-FPH in an organic solvent two-phase system. Under coupling with NADH regeneration using 2-propanol, 1 L of the cultured broth of an E. coli transformant expressing the AFPDH gene reduced 150 g of AFP to (R)-FPH. The optical purity of the (R)-FPH formed was 100% enantiomeric excess under both reaction conditions.

Purification and characterization of an NADH-dependent alcohol dehydrogenase from Candida maris for the synthesis of optically active 1-(pyridyl)ethanol derivatives.

A novel (R)-specific alcohol dehydrogenase (AFPDH) produced by Candida maris IFO10003 was purified to homogeneity by ammonium sulfate fractionation, DEAE-Toyopearl, and Phenyl-Toyopearl, and characterized. The relative molecular mass of the native enzyme was found to be 59,900 by gel filtration, and that of the subunit was estimated to be 28,900 on SDS-polyacrylamide gel electrophoresis. These results suggest that the enzyme is a homodimer. It required NADH as a cofactor and reduced various kinds of carbonyl compounds, including ketones and aldehydes. AFPDH reduced acetylpyridine derivatives, ß-keto esters, and some ketone compounds with high enantioselectivity. This is the first report of an NADH-dependent, highly enantioselective (R)-specific alcohol dehydrogenase isolated from a yeast. AFPDH is a very useful enzyme for the preparation of various kinds of chiral alcohols.

Microbial enantioselective reduction of acetylpyridine derivatives.

The microbial enantioselective reduction of acetylpyridine derivatives was studied. Many microorganisms were found to reduce 5-acetylfuro[2,3-c]pyridine (AFP) to (S)-5-(1-hydroxyethyl)furo[2,3-c]-pyridine (FPH). Candida maris IFO10003 reduced AFP to (R)-FPH with high enantioselectivity. The microbial reduction reaction was optimized. The aeration conditions and glucose concentration affected the yield and stereoselectivity. The cells accumulated 17.5 g/l (107 mM) of (R)-FPH with a 99% yield and 97% enantiomeric excess (e.e.). A cell-free extract of C. maris accumulated 91.5 g/l (559 mM) with over 99% e.e. with enzymatic NADH regeneration. (R)-FPH is an important intermediate for the synthesis of HIV reverse-transcriptase inhibitor, and other optically active 1-(pyridyl)ethanol derivatives are versatile chiral building blocks for asymmetric synthesis.