Experimental and Theoretical Studies on the Pharmacodynamics of Cisplatin in Jurkat Cells

For Jurkat cells in culture exposed to cisplatin (1), we measured the number of platinum adducts on DNA and showed that it is proportional to the AUC, the area under the concentration vs time curve, for cisplatin. The number of platinum-DNA adducts is measured immediately following exposure to drug. The AUC is calculated either as the product of the initial cisplatin concentration and the exposure time or as the integral under the concentration vs time curve for the unreacted dichloro species, which decreases exponentially. We also show that the number of adducts correlates with decreases in respiration, with the amount of DNA fragmentation, and with cell viability, all measured 24 h after exposure to the drug. To study the reactions of cisplatin at concentrations approaching clinical relevance (65 microM), we use two-dimensional [1H15N]HSQC NMR and the 15N-labeled form of the drug, cis-Pt(15NH3)2Cl2, 1. In the absence of cells, 1 reacts with components of the growth medium and also transforms slowly (k(h) = 0.205 h-1 at 37 degrees C) into the chloro-aquo species, cis-[Pt(15NH3)2Cl(H2O)]+ (2), which at the pH of the medium (pH 7.15), is mainly in the deprotonated chloro-hydroxy form, cis-Pt(15NH3)2Cl(OH) (4). The concentration of 2 (4), as measured by HSQC NMR, decreases due to reaction with components of the medium. In the presence of 5 million or more cells, the concentration of 1 decreases with time, but the NMR signal for 2 (4) is not seen because it is rapidly removed from solution by the cells, keeping its concentration very low. These experiments confirm that the species preferentially removed from the medium by cells is 2 (4) and not 1. Our findings are discussed in the context of a kinetic model for platination of nuclear DNA by cisplatin, which includes aquation of cisplatin outside the cell, passage of 2 (4) through the cell membrane, reaction of reactive platinum species (RPS) in the cytosol with thiols, formation of adducts between RPS and accessible sites on genomic DNA, and removal of platinum from DNA by repair. Some of the rate constants involved are measured, but others can only be estimated. Calculations with this model show that little of the platinum reacts with intracellular thiols before reaching the nuclear DNA, indicating that binding to thiols is not important in cisplatin resistance. The model also predicts the circumstances under which the amount of platination of nuclear DNA is proportional to AUC

Nutritional Composition and Bioactivity of Salicornia europaea L. Plants Grown in Monoculture or Intercropped with Tomato Plants in Salt-Affected Soils

The increasing salinization of agricultural soils urges us to find alternative and sustainable farming systems in order to allow the exploitation of areas that are otherwise becoming less suitable for conventional crops. Thanks to their adaptation to extreme saline conditions, halophytes are promising plants for resilient farming systems, such as intercropping with glycophytes, to ameliorate their productivity in saline soils. This research aimed to evaluate whether the nutritional profile and the content of some health-promoting compounds of the edible portion of Salicornia europaea were influenced by its cultivation in consociation with tomato plants. Moreover, the antioxidant, antibacterial, and anti-inflammatory properties of S. europaea were studied to characterize its bioactivity. The farming system did not influence the concentration of nutrients and bioactive compounds, except for flavonoids. The antimicrobial and anti-inflammatory properties of Salicornia extract suggested the importance of this halophyte for animal and human health

The structure of the ternary Eg5–ADP–ispinesib complex

The human kinesin Eg5 is responsible for bipolar spindle formation during early mitosis. Inhibition of Eg5 triggers the formation of monoastral spindles, leading to mitotic arrest that eventually causes apoptosis. There is increasing evidence that Eg5 constitutes a potential drug target for the development of cancer chemotherapeutics. The most advanced Eg5-targeting agent is ispinesib, which exhibits potent antitumour activity and is currently in multiple phase II clinical trials. In this study, the crystal structure of the Eg5 motor domain in complex with ispinesib, supported by kinetic and thermodynamic binding data, is reported. Ispinesib occupies the same induced-fit pocket in Eg5 as other allosteric inhibitors, making extensive hydrophobic interactions with the protein. The data for the Eg5-ADP-ispinesib complex suffered from pseudo-merohedral twinning and revealed translational noncrystallographic symmetry, leading to challenges in data processing, space-group assignment and structure solution as well as in refinement. These complications may explain the lack of available structural information for this important agent and its analogues. The present structure represents the best interpretation of these data based on extensive data-reduction, structure-solution and refinement trials

Effects of Diabetes Prevention Education Program for Overweight and Obese Subjects with a Family History of Type 2 Diabetes Mellitus: A Pilot Study from the United Arab Emirates

Objectives: The association of obesity and family history of type 2 diabetes mellitus (T2DM) provides an opportunity for risk stratification and prevention, as these two conditions are the most well-known risk factors for T2DM. We aimed to test the feasibility and effects of a diabetes mellitus prevention education program designed for overweight and obese Emirati people with at least one parent with T2DM. Methods: We conducted a pilot study using a pre-post design without a control arm at the Diabetes Center at Tawam Hospital in Al Ain, UAE. Overweight and obese subjects with at least one parent with T2DM were invited to participate. Three study assessments were conducted at baseline, three months, and six months including a questionnaire, anthropometry, and laboratory assessments. Interventions included three individualized or family-engaged counseling sessions based on the DiAlert protocol. The study outcomes included awareness of risks and prevention opportunities to T2DM, behavior changes in nutrition and exercise, decreased waist-circumference, and clinical/metabolic/inflammatory markers. Pre-post changes were analyzed using repeated-measures analysis of variance. Results: One hundred twenty-two overweight or obese individuals were approached. Forty-four individuals met the eligibility criteria, and 32 individuals (35.0±9.0 years; 75.0% female) completed the study. At six months, there were significant improvements in the glycated hemoglobin levels (p = 0.007), high-density lipoprotein (p < 0.049), serum creatinine (p < 0.025), estimated glomerular filtration rate (p = 0.009), and adiponectin levels (p < 0.024). Sixteen of 32 participants had ≥ 2 cm reduction in waist circumference. They demonstrated notable physical and laboratory improvements in moderate-vigorous activity, average activity counts per day, tumor necrosis factor-alpha, and interleukin-6 total cholesterol, triglyceride, and low-density lipoprotein. Conclusions: Offering family-oriented diabetes education to people at risk for T2DM is well received and has favorable effects on relevant risk factors. Better testing with large-scale randomized controlled studies is needed, and implementing similar educational programs for the Emirati population seems warranted

A phase II irinotecan–cisplatin combination in advanced pancreatic cancer

We report a cisplatin and irinotecan combination in patients with biopsy-proven advanced pancreatic adenocarcinoma. Patients were selected from a specialist centre and required good performance status (KPS&gt;70%), measurable disease on CT scan, and biochemical and haematological parameters within normal limits. Based on a two-stage phase II design, we aimed to treat 22 patients initially. The study was stopped because of the death of the 19th patient during the first treatment cycle, with neutropenic sepsis and multiorgan failure. A total of 89 treatments were administered to 17 patients. Serious grade 3/4 toxicities were haematological (neutropenia) 6%, diarrhoea 6%, nausea 7% and vomiting 6%. Using the clinical benefit response (CBR) criteria, no patients had an overall CBR. For responses confirmed by CT examination, there was one partial response (5%), three stable diseases lasting greater than 6 weeks (16%), with an overall 22% with disease control (PR+SD). The median progression-free and overall survival was 3.1 months (95% CI: 1.3-3.7) and 5.0 (95% CI: 3.9-10.1) months, respectively. Although this synergistic combination has improved the response rates and survival of other solid tumours, we recommend caution when using this combination in the palliation of advanced pancreatic cancer, because of unexpected toxicity