Rates of intercalator-driven platination of DNA determined by a restriction enzyme cleavage inhibition assay

A restriction enzyme cleavage inhibition assay was designed to determine the rates of DNA platination by four non-cross-linking platinum–acridine agents represented by the formula [Pt(am₂)LCl](NO₃)₂, where am is a diamine nonleaving group and L is an acridine derived from the intercalator 1-[2-(acridin-9-ylamino)ethyl]-1,3-dimethylthiourea (ACRAMTU). The formation of monofunctional adducts in the target sequence 5′-CGA was studied in a 40-base-pair probe containing the EcoRI restriction site GAATTC. The time dependence of endonuclease inhibition was quantitatively analyzed by polyacrylamide gel electrophoresis. The formation of monoadducts is approximately 3 times faster with double-stranded DNA than with simple nucleic acid fragments. Compound 1 (am₂ is ethane-1,2-diamine, L is ACRAMTU) reacts with a first-order rate constant of k _obs = 1.4 ± 0.37 × 10⁻⁴ s⁻¹ (t _1/2 = 83 ± 22 min). Replacement of the thiourea group in ACRAMTU with an amidine group (compound 2) accelerates the rate by fourfold (k _obs = 5.7 ± 0.58 × 10⁻⁴ s⁻¹, t _1/2 = 21 ± 2 min), and introduction of a propane-1,3-diamine nonleaving group results in a 1.5-fold enhancement in reactivity (compound 3, k _obs = 2.1 ± 0.40 × 10⁻⁴ s⁻¹, t _1/2 = 55 ± 10 min) compared with the prototype. Derivative 4, containing a 4,9-disubstituted acridine threading intercalator, was the least reactive compound in the series (k _obs = 1.1 ± 0.40 × 10⁻⁴ s⁻¹, t _1/2 = 104 ± 38 min). The data suggest a correlation may exist between the binding rates and the biological activity of the compounds. Potential pharmacological advantages of rapid formation of cytotoxic monofunctional adducts over the common purine–purine cross-links are discussed.     

Does a MediDiet With Additional Extra Virgin Olive Oil and Pistachios Reduce the Incidence of Gestational Diabetes?

ObjectiveThe present study aimed to evaluate gestational diabetes mellitus (GDM) incidence in pregnant women following the Mediterranean diet (MedDiet) with the addition of extra virgin olive oil (EVOO) and pistachios.MethodsA total of 560 pregnant patients were enrolled in the present study. The MedDiet was introduced in both the interventional group (IG) and the control group. The women in the IG received 40 mL of EVOO every day along with 25 to 30 g of roasted pistachios. The incidence of GDM was recorded along with specific maternal and neonatal outcomes.ResultsThe nutritional scores and MedDiet adherence screener scores were not statistically different between the groups at baseline, but the difference was statistically significant and higher in the IG at 24 to 28 weeks (P = .001) and at 36 to 38 weeks (P = .001). GDM was diagnosed in 51 (20.4%) women in the control group and 34 (13.6%) women in the IG. The MedDiet significantly reduced GDM incidence (P = .02) after adjusting for confounding factors.ConclusionThe present study shows that dietary intervention in pregnant women, including a MedDiet and increased consumption of EVOO and pistachios, decreases the incidence of GDM.     

Ultrastructural observation on the rat supraoptic neurons following acute operative stress

The response of the SON to various forms of stress is well documented. However, the effect of operative stress, which is a common and important clinical event requiring the mediation of vasopressin, has largely escaped attention. The present report describes the ultrastructural changes in the neurons of the caudal (retrochiasmatic) part of the SON following a deepseated linear incision on the dorsum of the rat. The observations were confirmed to the first forty-eight hours after trauma. At 24-hours post-operatively, a marked depletion of the neurosecretory granules was observed. This was associated with a proliferation of the granular and smooth endoplasmic reticulum, Golgi cisternae and ribosomes. A few of the neurosecretory granules were seen to lie in the close vicinity of the Golgi complexes. At 48-hours after trauma, these features persisted. In addition, an accumulation of neurosecretory granules was conspicuous in some axon pre-terminals. From the above findings, it is suggested that an increased demand for vasopressin during the early postoperative period is met by the supraoptic neurons by a liberation of their neurosecretory contents. An attempt at replenishment of the latter is evidenced by a proliferation in the membrane components and ribosomes. The pooling of neurosecretory granules in occasional axon pre-terminals may indicate an imbalance in the synthesis-secretion coupling of vasopressin.     

Cellular and chloroplast lipid composition of the leaves of Mimosa pudica

Cellular and chloroplast lipids of the leaves of Mimosa pudica have been analysed. Qualitatively the total lipid composition of this plant is similar to that reported for the photosynthetic tissues of other plants. Chloroplast lipids show some resemblance to those of algae. The cerebroside fraction of both leaves and chloroplasts contains a polyunsaturated fatty acid (20:4ω3) and a long chain sphingosine base whose R_f value coincides with that from ox brain cerebroside and not with that of phytosphingosine from spinach.     

Benthic isopods (Crustacea,Malacostraca) from the Ross Sea,Antarctica: species checklist and their zoogeography in the Southern Ocean

In this study isopod species of the Ross Sea were investigated. Literature until May 2008 was checked to provide an overview of all known and described species in the Ross Sea. This species checklist was then enlarged through material of the 19th Italica expedition in 2004. During this expedition for the first time a small mesh net (500 μm) was used. Nine thousand four hundred and eighty one isopod specimens were collected during this expedition. Through this material the number of isopod species in the Ross Sea increased from 42 to 117 species, which belong to 20 families and 49 genera. Fifty-six percentage of the isopods species collected during the Italica expedition are new to science. The zoogeography of the 117 species was investigated. A non-transformed binary presence-absence data matrix was constructed using the Bray–Curtis coefficient. The results were displayed in a cluster analysis and by nonmetric multidimensional scaling (MDS). This paper gives a first insight into the occurrence and distribution of the isopod species of the Ross Sea.     

The small intestine can both absorb and glucuronidate luminal flavonoids.

We have studied the perfusion of the jejunum and ileum in an isolated rat intestine model with flavonoids and hydroxycinnamates and the influence of glycosylation on the subsequent metabolism. Flavone and flavonol glucosides and their corresponding aglycones are glucuronidated during transfer across the rat jejunum and ileum and this glucuronidation occurs without the need for gut microflora. Furthermore, this suggests the presence of glycosidases as well as UDP-glucuronyl transferase in the jejunum. In contrast, quercetin-3-glucoside and rutin are mainly absorbed unmetabolised. The results suggest that the more highly reducing phenolics are absorbed predominantly as glucuronides (96.5%+/-4.6) of the amount absorbed, whereas monophenolic hydroxycinnamates and monophenolic B-ring flavonoids are less predisposed to glucuronidation and higher levels of aglycone (88.1%+/-10.1) are detected on absorption through both the jejunum and ileum.     

Body size,fitness and compatibility in Barnacle Geese Branta leucopsis

Large-sized Barnacle Geese Branta leucopsis of both sexes had a higher probability of breeding successfully in any particular year and produced more goslings than did smaller birds. Large females paired at an earlier age, suggesting that they were preferred as mates and were likely to have entered the breeding population earlier. The relative sizes of the pair bond members also affected fitness. Most birds were able to maximize their breeding performance by mating with relatively similar sized partners; the greater the size disparity of mates, the lower the breeding performance. This supports the idea that compatibility of mates may be important in determining fitness of the pair. The success of different pair types was also affected by environmental conditions, with certain size combinations doing better in some years and poorly in other years.