Simultaneous determination of intracellular reduced and oxidized glutathiones by the König reaction.

The König reaction is commonly used for the detection of cyanide and its derivatives, including thiocyanate and selenocyanate. We found that this reaction can be used to quantify glutathione fluorometrically, and applied it to the simultaneous determination of reduced and oxidized glutathiones (GSH and GSSG) using a conventional LC system with isocratic elution. The limits of detection were 6.04 nM and 9.84 nM for GSH and GSSG, respectively, and the limits of quantification were 18.3 nM and 29.8 nM, respectively. We also determined GSH and GSSG levels in PC12 cells exposed to paraquat, an oxidative stressor, and observed a decrease in GSH/GSSG ratio, as expected. Total GSH levels quantified by this method and by the conventional colorimetric method with 5,5'-dithiobis(2-nitrobenzoic acid) were comparable. Our new application of the König reaction offers a reliable and useful method to simultaneously quantify intracellular GSH and GSSG.

Outcomes of combined gonioscopy-assisted transluminal trabeculotomy and goniosynechialysis in primary angle closure: a retrospective case series.

PURPOSE: To evaluate the additional intraocular pressure (IOP) lowering effect of gonioscopy-assisted transluminal trabeculotomy (GATT) to contemporary goniosynechialysis (GSL) in endeavouring to abolish subsequent occlusion after chronic iridotrabecular contact in primary angle closure (PAC) patients. METHODS: A retrospective case series of all PAC eyes underwent GATT + GSL with or without phacoemulsification and intraocular lens implantation (PEA + IOL) from December 2016 to May 2018 were recruited. IOP and the number of anti-glaucoma medications were compared pre- and post-operatively by Wilcoxon signed-rank test. Repeated measure ANOVA was used to evaluate the difference in IOP change after the operation between a subgroup of operations (GATT + GSL + PEA + IOL and GATT + GSL) and the arc of cutting of trabeculotomy. RESULTS: Thirty-nine eyes of 30 patients, 37 chronic angle closure glaucoma (CACG), 1 acute primary angle closure (APAC), and 1 plateau iris syndrome were recruited. Mean preoperative IOP was 21.8 ± 5.4 mmHg. Mean post-operative IOP was lowered to 15.1 ± 3.8 mmHg at 1 month, 14.4 ± 1.2 mmHg at 3 months, 14.8 ± 2.1 mmHg at 6 months, 14.5 ± 0.8 mmHg at 1 year, and 15 at 2 years (P < 0.001, P = 0.0012, P = 0.001, P = 0.028, and P = 0.317 (n = 1), consecutively). Mean of overall post-operative IOP at the last follow-up was 15.1 ± 4.4 mmHg (P < 0.001). Mean preoperative number of anti-glaucoma medications was 3.5 ± 1.4. Mean post-operative number of anti-glaucoma medications was reduced to 1.5 ± 1.4 at 1 month, 0.9 ± 0.9 at 3 months, 1.4 ± 1.4 at 6 months, 1.5 ± 0.5 at 1 year, and 2 at 2 years (P < 0.001, P = 0.01, P = 0.002, P = 0.028, and P = 0.317 (n = 1), respectively). Mean of overall post-operative number of anti-glaucoma medications was 1.1 ± 1.2 (P < 0.001). There was no significant difference found between the IOP lowering effect in subgroup analysis. CONCLUSION: GATT + GSL could significantly reduce IOP and number of anti-glaucoma medications from baseline compared to the last follow-up; however, there seemed not to be any superiority to the effects found in previous studies reported about GSL + PEA or PEA alone in PAC patients.

Identification of circadian clock modulators from existing drugs.

Chronic circadian disruption due to shift work or frequent travel across time zones leads to jet-lag and an increased risk of diabetes, cardiovascular disease, and cancer. The development of new pharmaceuticals to treat circadian disorders, however, is costly and hugely time-consuming. We therefore performed a high-throughput chemical screen of existing drugs for circadian clock modulators in human U2OS cells, with the aim of repurposing known bioactive compounds. Approximately 5% of the drugs screened altered circadian period, including the period-shortening compound dehydroepiandrosterone (DHEA; also known as prasterone). DHEA is one of the most abundant circulating steroid hormones in humans and is available as a dietary supplement in the USA Dietary administration of DHEA to mice shortened free-running circadian period and accelerated re-entrainment to advanced light-dark (LD) cycles, thereby reducing jet-lag. Our drug screen also revealed the involvement of tyrosine kinases, ABL1 and ABL2, and the BCR serine/threonine kinase in regulating circadian period. Thus, drug repurposing is a useful approach to identify new circadian clock modulators and potential therapies for circadian disorders.

Photoluminescent Detection of Nitrite with Carbon Nanodots Prepared by Microwave-assisted Synthesis.

A photoluminescent detection method for nitrite with high selectivity and sensitivity using carbon nanodots (CNDs) is demonstrated. The selectivity of nitrite is accomplished by a highly specific diazotization reaction between nitrite and p-phenylenediamine (p-PDA). In the presence of nitrite, p-PDA easily reacts to form the diazonium cation in the acidic aqueous solution. By alkalization of the reaction mixture, diazonium cation of p-PDA was converted to an aryl radical to form aggregated CNDs, which causes the change in the photoluminescent intensity of CNDs. In the present method, nitrite can be selectively detected down to 1 µM over several anions, such as nitrate, perchlorate, sulfate, fluoride, chloride, and bromide at mM levels.

Morphological and histopathological changes in orofacial structures of experimentally developed acromegaly-like rats: an overview.

Tongue enlargement and mandibular prognathism are clinically recognized in almost all patients with acromegaly. An acromegaly-like rat model recently developed by exogenous administration of insulin-like growth factor I (IGF-I) was used to investigate morphological and histopathological changes in orofacial structures and to clarify whether these changes were reversible. Exogenous administration of IGF-I evoked specific enlargement of the tongue with identifiable histopathological changes (increased muscle bundle width, increased space between muscle bundles, and increased epithelial thickness), elongation of the mandibular alveolar bone and ascending ramus, and lateral expansion of the mandibular dental arch. Regarding histopathological changes in the mandibular condyle, the cartilaginous layer width, bone matrix ratio, and number of osteoblasts were all significantly greater in this rat model. After normalization of the circulating IGF-I level, tongue enlargement and histopathological changes in the tongue and mandibular condyle were reversible, whereas morphological skeletal changes in the mandible remained.

Evaluation of superior BACE1 cleavage sequences containing unnatural amino acids.

A recombinant form of BACE1 (ß-site amyloid precursor protein cleaving enzyme-1) corresponding to positions 46-454 of the extracellular domain of the original membrane enzyme was prepared. The recombinant BACE1 (rBACE1) had the kinetic parameters K(m)=5.5µM and k(cat)=1719s(-1). Using several libraries of substrates containing unnatural amino acids, the specificity of rBACE1 was evaluated. LC/MS of digests derived from the libraries clarified that a dodecapeptide containing unnatural amino acids at P(2) to [Formula: see text] was a superior cleavage sequence.

Patient perceptions of different lancing sites for self-monitoring of blood glucose: a comparison of fingertip site with palm site using the OneTouch Ultra Blood Glucose Monitoring System.

BACKGROUND: Alternate-site testing (AST) for self-monitoring of blood glucose leads to improved glycemic control for treatment of diabetes mellitus. The aim of this randomized, open-label, two-period, crossover study was to compare the comfort of two different lancing sites, fingertip and palm sites, for AST in diabetes patients. METHODS: Patients injected insulin four times a day. Self-monitoring of blood glucose was carried out more than thrice daily with fingertip measurements for at least three months using apparatuses except the OneTouch Ultra Blood Glucose Monitoring System (OneTouch) before examination. The comfort of two lancing sites using OneTouch were compared. In two randomized groups that used one fingertip lancing site for one week followed by the alternate lancing site for another week, patients completed 11-item questionnaires assessing usability of the site before and after each week. Each item was scored on a visual analogue scale from -100 (most negative) to +100 (most positive). RESULTS: Most patients desired to continue AST, which was insignificantly different between the two lancing sites (fingertip and palm AST) in 43 diabetes patients aged 57.3 +/- 13.8 years, body mass index of 23.1 +/- 2.5 kg/m(2), diabetes duration of 19.6 +/- 9.7 years, and hemoglobin A1c of 7.4 +/- 1.1%. However, patients were less (p < .01) satisfied with using the palm lancing site as compared to the fingertip lancing site because of difficulties in inserting the needle, drawing blood samples, and applying enough blood into the test strip. CONCLUSIONS: These results suggest that patients desire to use the palm for AST, but more technological advances in AST of a palm site is required to reduce patient discomfort.

Excessive lateral dental arch expansion in experimentally developed acromegaly-like rats.

OBJECTIVE: To investigate morphological changes in the dental arches of acromegaly-like rats recently developed by means of exogenous IGF-I administration. DESIGN: Human recombinant IGF-I (640microg/day) was continuously administered subcutaneously for 4 weeks by osmotic mini-pumps to 10-week-old male rats (n=6). Control animals were injected with saline alone (n=6). After administration, all the rats were housed for 4 more weeks. Arch width (W), length (L) and angle (theta) in the mandible and maxilla were measured once a week during and after IGF-I administration. RESULTS: The concentration of circulating IGF-I, and W and theta in the mandible were significantly increased as compared with the control rats. Although the mandibular dental arch stopped expanding once administration ended, it did not return to the control size. CONCLUSIONS: In our acromegaly-like rat model, mandibular dental arch growth is greater in the lateral than antero-posterior direction during and after IGF-I administration.