Increased concentrations of the oxidative DNA adduct 7, 8-dihydro-8-oxo-2-deoxyguanosine in the germ-line of men with type 1 diabetes

The effects of diabetes mellitus on male reproductive health have not been clearly defined. A previous publication from this group reported significantly higher levels of nuclear DNA fragmentation and mitochondrial DNA deletions in spermatozoa from men with type 1 diabetes. This study compared semen profiles, sperm DNA fragmentation and levels of oxidative DNA modification in spermatozoa of diabetic and non-diabetic men. Semen samples from 12 non-diabetic, fertile men and 11 type 1 diabetics were obtained and subjected to conventional light microscopic semen analysis. Nuclear DNA fragmentation was assessed using an alkaline Comet assay and concentrations of 7,8-dihydro-8-oxo-2-deoxyguanosine (8-OHdG), an oxidative adduct of the purine guanosine, were assessed by high-performance liquid chromatography. Conventional semen profiles were similar in both groups, whilst spermatozoa from type 1 diabetics showed significantly higher levels of DNA fragmentation (44% versus 27%; P < 0.05) and concentrations of 8-OHdG (3.6 versus 2.0 molecules of 8-OHdG per 105 molecules of deoxyguanosine; P < 0.05). Furthermore, a positive correlation was observed between DNA fragmentation and concentrations of 8-OHdG per 105 molecules of deoxyguanosine (rs = 0.7, P < 0.05). The genomic damage evident in spermatozoa of type 1 diabetics may have important implications for their fertility and the outcome of pregnancies fathered by these individuals.

Ionic liquid salt-induced inactivation and unfolding of cellulase from Trichoderma reesei

The potential for performing cellulase-catalyzed reactions on cellulose dissolved in 1-butyl-3-methylimidazolium chloride ([bmim] Cl) has been investigated. We have carried out a systematic study on the irreversible solvent and ionic strength-induced inactivation and unfolding of cellulase from Trichoderma reesei ( E.C.#3.2.1.4). Experiments, varying both cellulase and IL solvent concentrations, have indicated that [bmim] Cl, and several other ILs, as well as dimethylacetamide-LiCl (a well-known solvent system for cellulose), inactivate cellulase under these conditions. Despite cellulase inactivity, results obtained from this study led to valuable insights into the requirements necessary for enzyme activity in IL systems. Enzyme stability was determined during urea, NaCl, and [bmim] Cl-induced denaturation observed through fluorescence spectroscopy. Protein stability of a PEG-supported cellulase in [bmim] Cl solution was investigated and increased stability/activity of the PEG-supported cellulase in both the [bmim] Cl and citrate buffer solutions were detected.

Selection of an analytical method for evaluating bovine serum albumin concentrations in pharmaceutical polymeric formulations

Bovine serum albumin (BSA) is a commonly used model protein in the development of pharmaceutical formulations. In order to assay its release from various dosage forms, either the bicinchoninic acid (BCA) assay or a more specific size-exclusion high performance liquid chromatography (SE-HPLC) method are commonly employed. However, these can give erroneous results in the presence of some commonly-used pharmaceutical excipients. We therefore investigated the ability of these methods to accurately determine BSA concentrations in pharmaceutical formulations that also contained various polymers and compared them with a new and compared with a new reverse-phase (RP)–HPLC technique. We found that the RP-HPLC technique was the most suitable method. It gave a linear response in the range of 0.5 -100 µg/ml with a correlation coefficient of 0.9999, a limit of detection of 0.11 µg/ml and quantification of 0.33 µg/ml. The performed ‘t’ test for the estimated and theoretical concentration indicated no significant difference between them providing the accuracy. Low % relative standard deviation values (0.8-1.39%) indicate the precision of the method. Furthermore, the method was used to quantify in vitro BSA release from polymeric freeze-dried formulations.

No clear evidence of an association between plasma concentrations of n-3 long-chain polyunsaturated fatty acids and depressed mood in a non-clinical population

Previous research suggests that low n-3 long-chain polyunsaturated fatty acid (n-3PUFA) status is associated with higher levels of depression in clinical populations. This analysis aimed to investigate the relationship between depressed mood and n-3PUFA status in a non-clinical population. The analysis was conducted on data collected as part of a large randomized controlled trial investigating the impact of n-3PUFA supplementation on depressed mood in a community-based population. On entry into the trial, data on depressed mood were collected using the Depression, Anxiety and Stress Scales (DASS) and the Beck Depression Inventory (BDI). Plasma concentrations of various n-3PUFAs and n-6 long-chain polyunsaturated fatty acids (n-6PUFAs) were obtained from fasting venous blood samples, and various demographics were also measured. Using regression, there was no evidence of an association between either measure of depressed mood and any of the measures of n-3PUFA status or of n-6PUFA: n-3PUFA ratios. Clear associations were also not found when demographic factors were included in the analyses. These findings suggest that n-3PUFAs may not have a role in the aetiology of minor depression. This is also consistent with the results of other studies that have not demonstrated an association between depressed mood and n-3PUFA status in non-clinical populations and epidemiological studies that have not demonstrated an association between depressed mood and n-3PUFA intake in these populations. (C) 2008 Elsevier Ltd. All rights reserved.

Changes in antibiotic susceptibility in staphylococci habituated to sub-lethal concentrations of tea tree oil (Melaleuca alternifolia)

Aims: To investigate the effect of sub-lethal challenge with tea tree oil (TTO) on the antibiotic resistance profiles of staphylococci.

Leptin concentrations in maternal serum and cord blood in diabetic and nondiabetic pregnancy

OBJECTIVE: The purpose of this study was to examine the relationships between maternal and cord leptin concentrations, maternal and neonatal outcomes, and measures of glycemic control in diabetic and nondiabetic pregnancy.