Potent Rifampicin derivatives can clear MRSA infections at single low doses when concomitantly dosed with Vancomycin.

For a number of years, antimicrobial resistance (AMR) has been a critical issue for humanity. Drug discovery efforts have been very limited and the spread of bacterial pathogens has over-run our traditional arsenal of antibiotics. Bacteria can involve to evade compounds that can halt their rapid growth. The authors have discovered a potent macrocycle derivative that when dosed concomitantly with the standard of care (SOC) antibiotic vancomycin, can clear methicillin resistant Staphylococcus aureus (MRSA) infections. In addition, we have probed the lead compounds in Salmonella typhimurium bacterial strains. In vitro, in vivo, and ADME data have been included to stress the virtues of this new antibiotic.

Amino acid-mediated negatively charged surface improve antifouling and tribological characteristics for medical applications.

To prevent infections associated with biomedical catheters, various antimicrobial coatings have been investigated. However, those materials do not provide consistent antibacterial effects or biocompatibility, generally, due to degradation of the coating materials, in vivo. Additionally, biomedical catheters must have low surface friction to reduce tribological damage. In this study, we developed an antifouling surface composed of biocompatible amino acids (leucine, taurine, and aspartic acid) on polyimide, via modification using a series of facile immersion steps with waterborne reactions. The naturally derived amino acid could be formed highly biostable amide bonds on the polyimide surface like peptides. The amino acid-modified surface formed a water layer with antifouling performance through the hydrophilic properties of amino acids. Amino acid-mediated modification reduced adhesion up to 84.45% and 94.81% against Escherichia coli and Staphylococcus epidermidis, respectively, and exhibited an excellent prevention to adhesion against the proteins, albumin and fibrinogen. Evaluation of the surface friction of the catheter revealed a dramatic reduction in the tribological force after amino acid modification on polyimide that of 0.81 N to aspartic acid of 0.44 N. These results clearly demonstrate a reduced occurrence of infections, thrombi and tribological damage following the relatively facile surface modification of catheters. The proposed modification method can be used in a continuous manufacturing process via using the same time of modification steps for the easy producing the product. Moreover, the method uses biocompatible naturally derived materials and can be applied to medical equipment that requires biocompatibility and biofunctionality with polyimide surfaces.

Therapeutic Efficacy of Autologous Platelet Concentrate Injection on Macular Holes with High Myopia, Large Macular Holes, or Recurrent Macular Holes: A Multicenter Randomized Controlled Trial.

We aimed to evaluate the anatomical and functional outcomes of pars-plana vitrectomy (PPV) with or without autologous platelet concentrate (APC) injection in patients with recurrent macular holes (MHs), large MHs, or MHs with high myopia. This multicenter, prospective, interventional randomized controlled trial was conducted from March 2017 to April 2020. Participants were randomly allocated to a PPV group or a PPV+APC group. All participants underwent standard 25-gauge PPV, and eyes in the PPV+APC group underwent PPV with intravitreal APC injection before air-gas exchange. A total of 117 patients were enrolled (PPV group: n = 59, PPV+APC group: n = 58). Hole closure was achieved in 47 participants (79.7%) in the PPV group and 52 participants (89.7%) in the PPV+APC group. There were no between-group differences in the anatomical closure rate or functional outcomes including best-corrected visual acuity, metamorphopsia, pattern-reversal visual evoked potential, or Visual Function Questionnaire-25 score. The use of APC injection does not improve the anatomical and functional outcomes of surgery for large MHs, recurrent MHs, or MHs with high myopia. The adjunctive use of APC can be considered in selected cases because it is not inferior to conventional MH surgery, is relatively simple to perform, and is not affected by the surgeon's skill.

The efficacy of selective retina therapy for diabetic macular edema based on pretreatment central foveal thickness.

To evaluate the efficacy of selective retina therapy (SRT) in patients with diabetic macular edema (DME) based on pretreatment central foveal thickness (CFT). Seventy-two eyes of 63 patients with DME who had previously undergone SRT were included. Patients were divided into two groups based on the CFT at baseline. Group 1 was composed of 35 eyes with CFT < 400 µm and group 2 was composed of 37 eyes with CFT ≥ 400 µm. Changes in best corrected visual acuity (BCVA) and CFT were measured at baseline, 3 and 6 months after SRT. A single-session retreatment was performed at 3-month posttreatment if there was no reduction in CFT. Rescue treatment with intravitreal anti-VEGF injections was performed if persistent DME or vision loss of 1 ≥ logMAR VA line was observed by 6 months after initial SRT. Six months after SRT, group 1 showed reduction of 45.9 µm in mean CFT (P < 0.001) and gain of 0.13 logMAR in mean BCVA (P < 0.001), whereas group 2 experienced no significant change in CFT or BCVA. In group 1, retreatments were performed in 6 eyes (17.1%), and rescue treatment was performed in 1 eye (2.9%), whereas in group 2, retreatment was performed in 17 eyes (45.9%), and rescue treatments were administered in 27 eyes (73%) during a 6-month follow-up. Although SRT had limited effects as a treatment for severe DME, SRT monotherapy for mild DME was effective in improving BCVA and reducing CFT during a 6-month follow-up period.

Diabetic Nephropathy in Type 2 Diabetic Retinopathy Requiring Panretinal Photocoagulation.

PURPOSE: To investigate the risk factors of diabetic nephropathy in patients with diabetic retinopathy requiring panretinal photocoagulation (PRP) and the visual prognosis. METHODS: A retrospective review of electronic medical records was conducted at Seoul St. Mary's Hospital, comprising 103 patients with type 2 diabetes mellitus and diabetic retinopathy who underwent PRP from 1996 to 2005. Patients with type 1 diabetes mellitus, non-diabetic renal disease, non-diabetic retinal disease, visually significant ocular disease, high-risk proliferative diabetic retinopathy, and advanced diabetic retinopathy were excluded. The patients were divided into three groups: no nephropathy (group 1, n = 45), microalbuminuria (group 2, n = 16), and advanced nephropathy (group 3, n = 42). Duration of diagnosis of retinopathy and nephropathy, glycosylated hemoglobin, visual acuity, complications, and treatment history were investigated. RESULTS: The mean glycosylated hemoglobin of group 3 (8.4 ± 1.2) was higher than that of group 1 (7.7 ± 1.0) or group 2 (7.7 ± 1.0) (p = 0.04). Mean interval from PRP to diagnosis of nephropathy was 8.8 ± 6.0 years in group 2 and 8.7 ± 4.9 years in group 3. The significant decrease in visual acuity in group 3 (28 eyes, 35.9%) was significantly higher than that in group 1 (15 eyes, 18.1%, p = 0.01) or group 2 (6 eyes, 20.7%, p = 0.03). Only vitreous hemorrhage showed a significantly higher incidence in groups 2 and 3 than in group 1 (p = 0.02). Multivariate regression analysis revealed that female sex and lower glycosylated hemoglobin were significantly associated with a protective effect on development of nephropathy. CONCLUSIONS: In the clinical setting, many patients with PRP-requiring diabetic retinopathy develop nephropathy an average of 8 to 9 years after PRP. Male sex and higher glycosylated hemoglobin could be risk factors of nephropathy.

Quantitative analysis of retinal and choroidal microvascular changes in patients with diabetes.

The relationship between choroidal and retinal microvascular changes has not yet been well described, and there were limited data on diagnostic ability of optical coherence tomography (OCT)-derived vascular parameters for determining diabetic retinopathy (DR) progression. We quantitatively analyzed OCT-derived vascular parameters at superficial (SCP) and deep retinal capillary plexus (DCP), and choroid. We assessed foveal avascular zone (FAZ), vessel density, vessel length density, and choroidal vascularity index in conjunction with DR stage. In this study, patients with diabetes and healthy controls were retrospectively analyzed. One-hundred seventy-four eyes were divided into six groups as follows: Healthy controls, no DR, mild non-proliferative DR (NPDR), moderate NPDR, severe NPDR, and proliferative DR. There were significant quantitative changes in retinal and choroidal vascular parameters with DR progression. The FAZ area and perimeter correlated positively with worsening DR severity; the FAZ circularity index, retinal vessel density, retinal vessel length density, and choroidal vascularity index correlated negatively with worsening severity. Among these, FAZ circulatory index demonstrated good diagnostic performance for DR. Our results cautiously suggest that functional circulatory disturbances in retinal and choroidal vasculatures occur before DR presents. As DR progresses, DCP retinal microvasculature changes precede SCP changes.

Ocular Manifestations of Biopsy-Proven Pulmonary Sarcoidosis in Korea.

PURPOSE: To investigate the clinical features and ocular manifestations of biopsy-proven pulmonary sarcoidosis in Korea. METHODS: 55 patients diagnosed with pulmonary sarcoidosis by bronchoscopic or excisional biopsy were included. By retrospective clinical chart review, we investigated features of uveitis, ocular and systemic treatments, visual acuity, angiotensin-converting enzyme level, chest radiography, and pulmonary function tests. Clinical features were analyzed by presence of uveitis, site of biopsy, and first manifested sign of sarcoidosis. RESULTS: The group with uveitis (n = 39) presented with higher systemic (71.8%) and immunosuppressive treatment rates (35.9%) than the group without uveitis (31.3%, 0%, resp.) (P = 0.007, P = 0.005, resp.). There were no significant differences in clinical features, including systemic treatment rate, by type of biopsy. Of 39 patients with uveitis, the group with ocular manifestation as a first sign of sarcoidosis showed higher systemic and immunosuppressive treatment rates (88.9%, 55.6%) compared to the group with pulmonary manifestation as a first sign (57.1%, 19.0%) (P = 0.037, P = 0.018, resp.). CONCLUSIONS: In patients with biopsy-proven pulmonary sarcoidosis, the presence of ocular involvement and uveitis as a first sign could be significant factors associated with higher systemic treatment rate, especially with immunosuppressive agents. Biopsy site determined by location and size had no influence on clinical features.

Patterns of ocular toxoplasmosis presenting at a tertiary eye care center in Korean patients.

The objective of this study was to describe demographic and clinical features of ocular toxoplasmosis (OT) in Korean patients compared to those in other countries.This retrospective study comprised 46 patients diagnosed with OT. All participants were recruited at the uveitis clinic in Seoul St. Mary's Hospital.The mean age of patients was 54 years. Of 46 patients, 31 (67.4%) were females. Of all patients, 24 (52.2%) had definite eating history of wild boar meat or deer blood while 5 (10.9%) had history of close contact with cats. The most common forms of OT were vitritis (91.3%) combined with retinochoroiditis (65.2%). Active retinochoroidal lesion was located at the peripheral retina in 18 (39.1%) patients, central retina in 8 (17.4%) patients, and peripapillary retina in 4 (8.7%) patients. Seven (15.2%) cases were clinically diagnosed with typical OT without serologic evidence. Thirty-nine (84.8%) had serum IgG for toxoplasmosis. However, only 8 (17.4%) had serum IgM. In 65.2% of patients, there was no complication after treatment. The most common ocular complication was macular scar (8.7%).The present study provides demographic and clinical characteristics of OT in Korea, a low endemic area of Toxoplasma gondii. Acquired infection is the major cause of OT in Korea. Even though Korea is a low endemic area of Toxoplasma gondii, OT is a preventable and common cause of acquired infectious uveitis.

Scleral Buckling under a Slit-lamp Illumination System with a Contact Wide-angle Viewing Lens Compared with an Indirect Ophthalmoscope.

PURPOSE: To investigate the outcomes of scleral buckling surgery performed under a slit-lamp illumination system (Visulux) with a contact wide-angle viewing lens (Mini Quad) in patients with rhegmatogenous retinal detachment (RRD) and to compare these outcomes with those of surgery performed under an indirect ophthalmoscope. METHODS: By retrospective review of electronic medical records, patients with RRD who had undergone scleral buckling surgery were identified. Scleral buckling surgeries were performed with two illumination instruments, a slit-lamp (SL group) and an indirect ophthalmoscope (IO group). Subretinal fluid drainage, cryopexy, and intravitreal gas injection were performed optionally. At 6 months after surgery, anatomical and functional outcomes were evaluated and compared between the two groups. Operation time was also compared between the two groups. RESULTS: Of the 45 total patients (45 eyes), 28 were included in the SL group, and 17 were included in the IO group. In the SL and IO groups, the primary anatomical success rate was 89.3% and 88.2%, respectively (p = 0.92). The logarithm of the minimal angle of resolution change, which reflects improvement in best-corrected visual acuity after surgery, was -0.19 ± 0.38 in the SL group and -0.21 ± 0.63 in the IO group; this difference was not statistically significant (p = 0.91). The mean operation time was significantly shorter in the SL group (78.9 ± 11.8 minutes) than in the IO group (100.0 ± 13.9 minutes, p < 0.001), especially for patients who underwent additional procedures such as subretinal fluid drainage and cryopexy (81.4 ± 12.9 and 103.5 ± 12.3 minutes, respectively, p < 0.001). CONCLUSIONS: Scleral buckling surgery performed under a slit-lamp illumination system yielded a similar anatomical success rate and similar functional improvement in RRD compared with surgery performed under an indirect ophthalmoscope. The slit-lamp system could save time, especially in bullous RRD, which requires additional subretinal fluid drainage.

Potential predictors for frequent relapse in human leukocyte antigen-B27-associated uveitis.

PURPOSE: To identify potential predictors for frequent relapse in a cohort of patients with human leukocyte antigen (HLA)-B27-associated uveitis in a tertiary referral center at the initial visit. METHODS: This retrospective cohort study comprised 130 patients diagnosed with HLA-B27-associated uveitis. Subjects were divided into two groups according to the frequency of uveitis attacks (number/year): frequent relapse (FR) (who relapsed more than twice a year, 38) and infrequent relapse (IR) group (who relapsed twice or less than twice a year, 92). RESULTS: The FR group presented more often with hypopyon or posterior synechiae at the initial presentation. Interestingly, posterior segment involvements including vitritis, vasculitis, or cystoid macular edema were not significantly different between the groups. In terms of laboratory findings, the erythrocyte sedimentation rate (ESR) was higher in the FR group. Multivariate Cox hazards analysis showed male sex, the presence of hypopyon, and ESR to be potential predictive factors for frequent relapse. CONCLUSION: We found that male sex, hypopyon at presentation, and high ESR are potential predictors for frequent relapse in HLA-B27-associated uveitis. Identifying patients at higher risk of relapse could provide important information for patients, allowing patients to understand their condition and increase their acceptance of strict management.

Administration of oral fluoroquinolone and the risk of rhegmatogenous retinal detachment: A nationwide population-based study in Korea.

PURPOSE: To investigate the association between oral fluoroquinolones (FQ) and the risk of rhegmatogenous retinal detachment (RRD) using a nationwide population-based study in Korea, designed to control for time-related bias. METHODS: As a nested case-control study within a cohort, the KNHIS-NSC 2002-2013 (Korean National Health Insurance Service National Sample Cohort) data used for the investigation. The subjects who visited an ophthalmologist were included in a cohort. Subjects with infectious ocular diseases, severe ocular trauma, and congenital diseases were excluded. Within the cohort, subjects who underwent surgery for RRD were defined as cases, and controls were matched by age group, sex, and cohort entry date using an incidence density sampling method. After investigating the exposure to oral FQ, the odds ratio was calculated by the FQ exposure rate of both groups and adjusted by the confounding factors of demography, health service utilization, and comorbidities. RESULTS: A total of 1,151 subjects in the case group and 11,470 subjects in the control group were included. There were intergroup differences in household income, numbers of ophthalmologic visits and drug prescriptions, events of intraocular surgeries, and prevalence of diabetes and degenerative myopia (all P's<0.05). The crude odds ratio of the total group was 1.06 (P = 0.53, 95% CI 0.88-1.28), and the odds ratio adjusted for all pre-defined confounders was 1.00 (P = 0.99, 95% CI 0.81-1.24). The crude and adjusted odds ratios were not showed statistical significance (all P's>0.05). CONCLUSIONS: By the nested case-control design, this study showed that oral administration of FQ was not associated with the increased risk of development of RRD.

Choroidal vascularity index in type-2 diabetes analyzed by swept-source optical coherence tomography.

The relationships between changes in choroidal vasculature and the severity of diabetic retinopathy (DR) remain unclear. We assessed choroidal changes in diabetic patients by measuring choroidal vascularity index (CVI) in conjunction with DR stage. In this study, patients with diabetes and healthy controls were retrospectively analyzed. Subjects were divided into seven groups as follows: Healthy controls, no DR, mild/moderate non-proliferative DR (NPDR), severe NPDR, proliferative DR (PDR), panretinal photocoagulation-treated DR, and clinically significant macular edema. The mean CVI values in the above groups were 69.08, 67.07, 66.28, 66.20, 63.48, 65.38, and 66.28, respectively. The eyes of diabetic patients exhibited a significantly lower CVI value than those of healthy controls even without DR. The PDR group exhibited a significantly lower CVI value than the healthy control, no DR, and mild/moderate NPDR groups. Age, sex, disease duration, glycated hemoglobin, fasting blood sugar, or intraocular pressure had no correlation with CVI. In multivariate regression analysis, thicker subfoveal choroid and thinner central retina were significantly associated with higher CVI values. These findings carefully suggest that changes in choroidal vasculature could be the primary event in diabetes even where there is no DR.

Analysis of choroidal and central foveal thicknesses in acute anterior uveitis by enhanced-depth imaging optical coherence tomography.

BACKGROUND: Currently, there are a limited number of reports of structural changes in the retina and choroid in acute anterior uveitis (AAU). The aim of this study was to evaluate choroidal and central foveal thicknesses during episodes of AAU. METHODS: The medical records of 120 patients with AAU and 120 healthy subjects matched for age, sex, and spherical equivalent of refractive error were reviewed. Subjects were divided into group 1 (AAU-affected eyes), 2 (unaffected fellow eyes), and 3 (healthy control eyes). RESULTS: In the uveitis group, etiologic diagnoses included human leukocyte antigen (HLA)-B27-associated (n = 71) and idiopathic (n = 49) AAU. The mean subfoveal choroidal thicknesses (SFCTs) in groups 1-3 were 326.7 ± 64.2, 296.1 ± 66.6, and 294.9 ± 41.7 µm, respectively. The corresponding mean central foveal thicknesses (CFTs) were 273.5 ± 29.3, 264.4 ± 24.6, and 263.0 ± 30.8 µm, respectively. The AAU group exhibited a significantly greater SFCT than the control groups (P < .001). Relative to the control group, while eyes with idiopathic AAU exhibited a significantly greater CFT, those with HLA-B27-associated AAU exhibited no such significant difference. Anterior chamber cell grade was not associated with SFCT or CFT. CONCLUSIONS: The SFCT increased significantly during AAU. This indicates the importance of OCT examination for detection of subclinical choroidal and retinal changes in all types of AAU.

Comparison of outcomes of scleral fixation with and without pars plana vitrectomy for the treatment of dislocated intraocular lens.

PURPOSE: To investigate the surgical outcomes of scleral fixation with either pars plana vitrectomy (ppV) or anterior vitrectomy (AV) for the treatment of dislocated intraocular lens (IOL). METHODS: By retrospective review of electronic medical records, patients with in-the-bag spontaneous IOL dislocation who underwent IOL exchange with scleral fixation were included and grouped according to the vitrectomy method: ppV (group 1) and AV (group 2). Post-operative surgical outcomes including visual acuity (log MAR), spherical equivalent, and surgically induced astigmatism (SIA) and complications were investigated and analyzed. RESULTS: After 6 months, post-operative measurements showed an average visual acuity of 0.16 ± 0.20, spherical equivalent of -1.48 ± 1.53D (diopters), and refractive shift of -0.19 ± 0.44D in group 1 (n = 19). There was no statistically significant difference between the measurements of group 1 and group 2 (n = 20) (0.10 ± 0.12, -2.00 ± 1.71D, -0.39 ± 0.57D, respectively) (p = 0.51, p = 0.29, p = 0.16, respectively). When analyzed by the algebraic and vector methods, group 1 did show a higher magnitude of surgically induced astigmatisms (1.61 ± 1.50D, 2.10 ± 1.03D, respectively) than did group 2 (0.49 ± 1.02D, 1.31 ± 0.83D respectively) (both p's = 0.01). There was no significant difference in the incidence of complications except for vitreoretinal complications, which were higher in group 2 (25%), compared with group 1 (0%) (p = 0.047). CONCLUSIONS: Both ppV and AV are appropriate options in patients who need IOL exchange with scleral fixation based on visual outcomes, refractive shifts, and complication rates. In terms of managing astigmatism, the AV procedure may be the better option.

Anti-TNFα Treatment for HLA-B27-Positive Ankylosing Spondylitis-Related Uveitis.

PURPOSE: To assess the long-term efficacy of the most widely used anti-tumor necrosis factor alpha (TNFα) agents for treatment of HLA-B27-positive ankylosing spondylitis (AS)-related uveitis. DESIGN: Retrospective cohort study. METHODS: The medical records of 143 patients with HLA-B27-positive AS who visited Seoul St. Mary's Hospital and were taking an anti-TNFα agent for at least 1 year were studied. Subjects were divided into 3 groups according to anti-TNFα treatment: Group 1 (infliximab, 66), Group 2 (adalimumab, 45), and Group 3 (etanercept, 32). RESULTS: Mean age was 41.0 ± 13.0 years, and 97 patients (67.8%) were male. Mean follow-up period was 70.6 ± 37.9 months. In cases of active ocular inflammation at the onset of anti-TNFα treatment, patients showed improved activity of uveitis after 24.0 ± 15.0 days (Group 1), 17.9 ± 6.0 days (Group 2), and 25.9 ± 18.0 days (Group 3). After the anti-TNFα treatment, 71 of 94 patients (32 [76.2%] in Group 1, 26 [78.8%] in Group 2, and 13 [68.4%] in Group 3) remained without uveitis relapse. A reduction in the number of systemic medications was achieved in 129 patients (90.2%). Twenty-eight cases of minor side effects were observed, and 4 cases were tuberculosis leading to discontinuation of anti-TNFα treatment. CONCLUSIONS: Infliximab, adalimumab, and etanercept were effective for treating and reducing the number of uveitis relapses in HLA-B27-positive AS. However, the risk of serious infections was noted, so ophthalmologists should consider the possibility that prolonged use of biologic agents may result in systemic side effects.

The Ability of 10-2 Short-Wavelength Perimetry in Detecting Functional Loss of the Macular Area in Preperimetric Glaucoma Patients.

PURPOSE: To better understand functional loss in the macular area of preperimetric glaucoma patients exhibiting structural loss by exploring correlations between parameters of the ganglion cell-inner plexiform layer (GCIPL) and 10-2 short-wavelength perimetry (SWAP). METHODS: One hundred thirty-four patients underwent 10-2 SWAP and conventional 24-2 visual field (VF) testing using a Humphrey field analyzer and macular scanning via Cirrus optical coherence tomography (OCT). Correlations between GCIPL thickness (GCIPLT) and the mean sensitivity (MS) of topographically corresponding areas explored in various VF tests were calculated. Correlations between GCIPL parameters and MS of the VF, in terms of the asymmetries of various VF sectors, were also determined. RESULTS: Glaucoma patients, preperimetric by standard 24-2 VF analysis but exhibiting GCIPL thinning, had lower MS in 10-2 SWAP and central 24-2 VF analyses. The correlations between average GCIPLT and the corresponding MS were significant for both 10-2 SWAP (r = 0.291, P = 0.018) and 24-2 standard automated perimetry (r = 0.235, P = 0.029). The associations between sectoral GCIPLT and the corresponding 10-2 SWAP MS were significant for all sectors, with the highest correlation evident in the inferotemporal (r = 0.324, P = 0.009) and the lowest in the superonasal GCIPL sectors (r = 0.214, P = 0.043). Asymmetric relationships between GCIPLT and 10-2 SWAP MS exhibited similar yet stronger correlations. CONCLUSIONS: Preperimetric glaucoma patients exhibiting structural loss in the macula also had functional loss revealed by 10-2 SWAP, which was less prominent in conventional 24-2 VF. Therefore, if structural abnormality is evident in the macular area, the central VF areas should be further examined even if the standard 24-2 data appear to be normal.

Automatic generation of nursing narratives from entity-attribute-value triplet for electronic nursing records system.

The aim of this study is to develop and evaluate a natural language generation system to populate nursing narratives using detailed clinical models. Semantic, contextual, and syntactical knowledges were extracted. A natural language generation system linking these knowledges was developed. The quality of generated nursing narratives was evaluated by the three nurse experts using a five-point rating scale. With 82 detailed clinical models, in total 66,888 nursing narratives in four different types of statement were generated. The mean scores for overall quality was 4.66, for content 4.60, for grammaticality 4.40, for writing style 4.13, and for correctness 4.60. The system developed in this study generated nursing narratives with different levels of granularity. The generated nursing narratives can improve semantic interoperability of nursing data documented in nursing records.

Development of Detection Methods for Cellulolytic Activity of Auricularia auricula-judae.

To obtain basic information on the detection of cellulolytic activity in Auricularia auricula-judae, the influences of dye reagent, pH, and temperature were assessed. Chromogenic dye (congo red, phenol red, remazol brilliant blue, and trypan blue) was individually incorporated into a medium containing either carboxymethyl-cellulose, Avicel, or D-cellobiose as a polysaccharide carbon substrate. The other assessments utilized pHs ranging from 4.5 to 8.0 and temperatures from 15~35℃. Overall, when A. auricula-judae species were transferred onto media contained Congo red and adjusted pH 7.0 and then incubated at 25℃ for 5 days, the clear zone indicative of cellulolytic activity was more pronounced.

Absolute Rate Constants for alpha-Amide Radical Reactions.

The 1-(diethylcarbamoyl)-6,6-diphenyl-5-hexenyl radical (4a), the 1-(diethylcarbamoyl)-7,7-diphenyl-6-heptenyl radical (4b), and the 1-(diethylcarbamoyl)-1-methyl-6,6-diphenyl-5-hexenyl radical (4c) were produced from the corresponding PTOC esters (anhydrides of the carboxylic acid and N-hydroxypyridine-2-thione) by laser flash photolysis methods. The kinetics of cyclizations of radicals 4a and 4b were measured at various temperatures, and that of cyclization of 4c was measured at ambient temperature. Radicals 4a and 4b were employed as radical clocks in indirect kinetic studies to determine rate constants for reaction of secondary alpha-amide radicals with Bu(3)SnH. The calibrated tin hydride trapping reaction was then employed to determine rate constants for cyclization of the 1-(diethylcarbamoyl)-5-hexenyl radical (12). The rate constants for 5-exo cyclizations of secondary alpha-amide radicals are similar to those of their isostructural alkyl radical analogues. The rate constants for the 5-exo cyclization of tertiary alpha-amide radical 4c and the 6-exo cyclization of the secondary alpha-amide radical 4b are smaller than those of the analogous alkyl radicals and alpha-ester substituted radicals, apparently due to steric effects. The rate constants for tin hydride trapping of secondary alpha-amide radicals are similar to those for reactions with secondary alpha-ester radicals.