Erythrocyte redox status in streptozotocin diabetic rats: effect of Casearia esculenta root extract

The present study was aimed to investigate the effect of Casearia esculenta root extract on erythrocyte lipid peroxidation and to assess the status of antioxidants in red blood cells of streptozotocin (STZ) diabetic rats. The study showed a significant elevation (p < 0.05) of erythrocyte thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation and significant reduction (p < 0.05) in reduced glutathione (GSH), ascorbic acid (vitamin C), alpha-tocopherol (vitamin E), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in the STZ diabetic rats. The study also observed significant reduction in membrane cholesterol and phospholipid content in STZ diabetic rats. By oral administration of C. esculenta (200 and 300 mg/kg body wt.) for 45 days to the diabetic rats these values approached almost normal levels. A dose of 300 mg/kg body weight C. esculenta extract showed better antioxidant effects than 200 mg/kg body weight.     

An optimum pH for the demonstration of chitin in Periplanata americana using Lugol's iodine.

Modification of chitosan test of Campbell is suggested with a controlled procedure involving heating with saturated potassium hydroxide at 160 degrees C for a period of 45 min and subsequent washing of the deacetylated chitin in running water and application of Lugol's iodine solution (1:2:300, w/w/v) at a pH range of 1.4 to 4.0, thus replacing the use of dilute sulphuric acid. Consistent results were obtained not only with the cuticle of Periplanata americana but also with the cuticle of Emerita asiatica (crustacea).     

Urinary L-lactate excretion is increased in renal Fanconi syndrome.

BACKGROUND: Measurement of l-lactate in body fluids is an established clinical tool to identify disorders of cellular respiration. However, there is very little known about the clinical value of urinary lactate measurements. We investigated urinary lactate excretion in children with renal Fanconi syndrome. METHODS: Freshly voided urine samples were obtained from children with Fanconi syndrome and controls both with and without renal disease. Urine lactate was estimated by conversion to pyruvate in the presence of lactate dehydrogenase and NAD. The NADH produced was measured photometrically. Urine lactate was factored for urine creatinine. RESULTS: Children with Fanconi syndrome had a significantly higher urine lactate/creatinine ratio [mean: 84 x 10(-2) mmol/mmol; 95% confidence interval (CI): 40.8-127.1 x 10(-2) mmol/mmol] than healthy controls (mean: 1.3 x 10(-2) mmol/mmol; CI: 1.1-1.5 x 10(-2) mmol/ mmol) and those with a variety of renal diseases (mean: 3.1 x 10(-2) mmol/mmol; CI: 1.8-4.5 x 10(-2) mmol/mmol). CONCLUSIONS: Urinary lactate is increased in Fanconi syndrome. The increase is likely to be due to reduced lactate co-transport in the proximal tubule. Urinary lactate/creatinine has clinical utility as a sensitive test of disordered proximal renal tubular function.     

Synthesis of aryl semicarbazones as potential anticonvulsant agents.

A series of 4-ethoxyphenyl semicarbazones (1-10) have been synthesized using an appropriate synthetic route and characterized by elemental analyses and spectral data. The anticonvulsant activity of all the synthesized compounds was evaluated against maximal electroshock induced seizures (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure models in mice. The neurotoxicity was assessed using the rotorod method. All the test compounds were administered at doses of 30, 100, and 300 mg/kg body weight and the anticonvulsant activity was noted at 0.5 and 4 h time intervals after the drug administration. Among the compounds tested, compounds except 3, 4 and 10 showed protection from seizures in both the animal models. Compounds 6 and 8 were found to increase gamma-aminobutyric acid (GABA) levels in the medulla oblongata region of the rat brain.     

Studies on metachromasia. III. Toluidine blue-substrate interaction and metachromasia.

With salts as substrates the metachromatic responses of the thiazine dye, Toluidine blue are studied. It is found that generally salts produce a gamma-metachromatic response. The substrate-dye interaction is studied in detail and the results are discussed in the light of various interpretations of previous workers. It is suggested that toluidine blue may have two sites that are responsible for the exhibition of green and red metachromatic responses. The influence of water on metachromasia has been studied and is reported to bring about an oscillation of spectral colours. Spectrophotometric studies were also carried out.     

Acceptability and Utility of the mySentry Remote Glucose Monitoring System

Background

The mySentry system (Medtronic Inc.) is the first to amplify and relay continuous glucose monitoring (CGM) and insulin pump data to a remote site within the house. Its usability and acceptability were evaluated in families having a child with type 1 diabetes.

Methods

Each enrolled family included a child (age 7–17 years) who used a Paradigm REAL-Time Revel sensor-augmented insulin pump (Medtronic). After a 1-week run-in phase, families set up and used the mySentry system for a 3-week study phase. Opinion surveys were completed by parents, and pump and CGM data were collected and analyzed retrospectively. No formal hypothesis testing was performed, and the study was not powered to detect changes in nocturnal glycemia.

Results

Thirty-five families completed the study. Enrolled children (61.1% female) had a mean (± standard deviation) age of 11.9 ± 2.70 years and a mean age at initiation of pump therapy of 7.1 ± 3.19 years. Baseline survey results indicated that most parents were fearful of their unawareness of their children’s nocturnal glucose excursions. The mySentry system met the predefined acceptability criteria for general experience, product usability, and training materials. There were no unanticipated device-related adverse effects. Among children who experienced nocturnal hypo- or hyperglycemic episodes in both phases of the study, there was a trend toward less frequent and less prolonged episodes during mySentry use.

Conclusions

The mySentry system met all predefined criteria for acceptability and did not demonstrate safety issues. Alerting parents to abnormal glucose values or trends may attenuate nocturnal hypoglycemia and hyperglycemia by prompting appropriate and timely intervention.     

A partial failure of membrane protein turnover may cause Alzheimer's disease: a new hypothesis

The amyloid hypothesis has dominated the thinking in our attempts to understand, diagnose and develop drugs for Alzheimer's disease (AD). This article presents a new hypothesis that takes into account the numerous familial AD (FAD) mutations in the amyloid precursor protein (APP) and its processing pathways, but suggests a new perspective beyond toxicity of forms of the amyloid beta-peptide (Abeta). Clearly, amyloid deposits are an invariable feature of AD. Moreover, although APP is normally processed to secreted and membrane-bound fragments, sAPPbeta and CTFbeta, by BACE, and the latter is subsequently processed by gamma-secretase to Abeta and CTFgamma, this pathway mostly yields Abeta of 40 residues, and increases in the levels of the amyloidogenic 42-residue Abeta (Abeta42) are seen in the majority of the mutations linked to the disease. The resulting theory is that the disease is caused by amyloid toxicity, which impairs memory and triggers deposition of the microtubule associated protein, Tau, as neurofibrillary tangles. Nevertheless, a few exceptional FAD mutations and the presence of large amounts of amyloid deposits in a group of cognitively normal elderly patients suggest that the disease process is more complex. Indeed, it has been hard to demonstrate the toxicity of Abeta42 and the actual target has been shifted to small oligomers of the peptide, named Abeta derived diffusible ligands (ADDLs). Our hypothesis is that the disease is more complex and caused by a failure of APP metabolism or clearance, which simultaneously affects several other membrane proteins. Thus, a traffic jam is created by failure of important pathways such as gamma-secretase processing of residual intramembrane domains released from the metabolism of multiple membrane proteins, which ultimately leads to a multiple system failure. In this theory, toxicity of Abeta42 will only contribute partially, if at all, to neurodegeneration in AD. More significantly, this theory would predict that focussing on specific reagents such as gamma-secretase inhibitors that hamper metabolism of APP, may initially show some beneficial effects on cognitive performance by elimination of acutely toxic ADDLs, but over the longer term may exacerbate the disease process by reducing membrane protein turnover.