Postmortem Changes in Catecholamines, Indoleamines, and Their Metabolites in Rat Brain Regions: Prevention with 10-kW Microwave Irradiation

Postmortem changes in catecholamines, indoleamines, and their metabolites in rat brain regions following decapitation were determined by LCEC. In the three regions studied neurotransmitter levels declined after decapitation, whereas the metabolite levels increased. Microwave irradiation at 10 kW rapidly inactivated brain enzymes and thus prevented the postmortem changes.     

Introducing novel potent anticancer agents of 1H-benzo[f]chromene scaffolds,targeting c-Src kinase enzyme with MDA-MB-231 cell line anti-invasion effect

In our effort to develop novel and powerful agents with anti-proliferative activity, two new series of 1H-benzo[f]chromene derivatives, 4a–h and 6a–h, were synthesised using heterocyclocondensation methodologies under microwave irradiation condition. The structures of the target compounds were established on the basis of their spectral data, IR, ¹H NMR, ¹³?C NMR, ¹³?C NMR-DEPT/APT, and MS data. The new compounds have been examined for their anti-proliferative activity against three cancer cell lines, MCF-7, HCT-116, and HepG-2. Vinblastine and Doxorubicin have been used as positive controls in the viability assay. The obtained results confirmed that most of the tested molecules revealed strong and selective cytotoxic activity against the three cancer cell lines. Moreover, these molecules exhibited weak cytotoxicity on the HFL-1?line, which suggested that they might be ideal anticancer candidates. The SAR study of the new benzochromene compounds verified that the substituents on the phenyl ring of 1H-benzo[f]chromene nucleus, accompanied with the presence of bromine atom or methoxy group at the 8-position, increases the ability of these molecules against the different cell lines. Due to their high anti-proliferative activity, compounds 4c and 6e were selected to be examined their proficiency to inhibit the invasiveness of the highly sensitive and invasive breast cancer cell line, MDA-MB-231. The anti-invasion behaviour of these molecules against the highly sensitive, non-oestrogen, and progesterone MDA-MB-231 cell line gave rise to their decreasing metastatic effect compared to the reference drug. Furthermore, this report explores the apoptotic mechanistic pathway of the cytotoxicity of the target compounds and reveals that most of these compounds enhance the Caspase 3/7 activity that could be considered as potential anticancer agents.     

Microwave Resonant Sensor for Non-invasive Characterization of Biological Tissues

Context

Microwave sensing appears to be an open wide field to investigate medical applications, such as monitoring of vital signs (temperature, arterial pressure, …), following different kinds of pathologies (cancer, glucose level …) and aid for medical diagnosis. It offers an alternative to determine the dielectric properties of biological tissues through the development of local non-invasive and/or embedded sensors, giving thus a kind of imaging by the dielectric contrast. Moreover, RF communications links between several sensors can be developed to realize “Body Area Networks”.

微波处理修复抗原后免疫组织化学方法效果的比较研究

冰冻切片经微波处理进行抗原修复后,免疫组织化学方法的敏感性明显提高,显色效果明显增强。提出了冰冻切片在免疫组织化学显色前进行抗原修复的必要性     

A simple and efficient synthesis of novel inhibitors of alpha-glucosidase based on benzimidazole skeleton and molecular docking studies

A novel series of benzimidazole derivatives were prepared starting from o-phenylenediamine and 4-nitro-o-phenylenediamine with iminoester hydrochlorides. Acidic proton in benzimidazole was exchanged with ethyl bromoacetate, then ethyl ester group was transformed into hydrazide group. Cyclization using CS₂/KOH leads to the corresponding 1,3,4-oxadiazole derivative, which was treated with phenyl isothiocyanate resulted in carbothioamide group, respectively. As the target compounds, triazole derivative was obtained under basic condition and thiadiazole derivative was obtained under acidic condition from cyclization of carbothioamide group. Most reactions were conducted using both the microwave and conventional methods to compare yields and reaction times. All compounds obtained in this study were investigated for α-glucosidase inhibitor activity. Compounds 6a, 8a, 4b, 5b, 6b and 7b were potent inhibitors with IC₅₀ values ranging from 10.49 to 158.2 μM. This has described a new class of α-glucosidase inhibitors. Molecular docking studies were done for all compounds to identify important binding modes responsible for inhibition activity of α-glucosidase.     

Delayed Cerebroventricular Metabolism of [125I]Angiotensins in the Spontaneously Hypertensive Rat

This study was designed to evaluate the hypothesis that impaired brain angiotensin signal termination contributes to the sustained blood pressure elevations noted in the genetically hypertensive rat model of human essential hypertension. A technique that combined the intracerebroventricular injection of [125I]angiotensins, followed by focused microwave fixation to stop all peptidase activity and subsequent HPLC analyses, was used for determining half-lives of [125I]angiotensin II and [125I]angiotensin III in the ventricular space. The results indicate that the spontaneously hypertensive rat evidenced significantly longer half-lives for intracerebroventricularly injected [125I]angiotensin II over those measured for the Wistar-Kyoto and Sprague-Dawley normotensive rat strains: 45.0, 27.2, and 25.0 s, respectively. This was also true for intracerebroventricularly administered [125I]angiotensin III: 19.5, 11.4, and 9.0 s, respectively. These results support the notion that a dysfunction in central aminopeptidase activity in the spontaneously hypertensive rat may result in prolonged half-lives of endogenously synthesized angiotensins II and III, which are known to serve as ligands at central angiotensin receptors responsible for the control of cardiovascular function. The extended half-lives of these ligands may contribute to the sustained elevations in blood pressure observed in this animal model.     

Cerebroventricular and Intravascular Metabolism of [125I]Angiotensins in Rat

This study compared the metabolism of [125I]angiotensin II (AII), [125I]angiotensin III (AIII), and [125I]Sar1,Ile8-AII (SI-AII) in the vascular and cerebroventricular compartments. Using HPLC methods to monitor degradation the following t1/2 values were established in the vascular compartment: AII, 12.7 +/- 1.4 s; AIII, 16.3 +/- 0.7 s; and SI-AII, 100.7 +/- 7.3 s. HPLC analysis also revealed that [125I]AII is converted in an obligatory manner to [125I]AIII during its degradation sequence. Cerebrospinal fluid contained no degradative capacity for [125I]AII but exhibited a significant capacity to degrade [125I]AIII. A technique that combined the intra-cerebroventricular injection of [125I]angiotensins followed by focused microwave fixation to stop all peptidase activity was used to determine the half-life of [125I]angiotensins in the ventricular space. Results indicated very rapid metabolism of angiotensins with the following t1/2 values: AII, 23.0 s; and AIII, 7.7 s. This extremely rapid, differential, and sequential metabolism of AII and AIII in two relevant body fluid compartments underscores the need for caution when interpreting data derived from intravascular and intracerebroventricular application of angiotensins. In addition the faster metabolism of AIII than AII in the ventricular space indicates that the actual potency of AIII at central angiotensin receptors is being underestimated.     

Oxygen consumption and flight muscle activity during heating in workers and drones of Apis mellifera

Summary Instantaneous oxygen consumption, muscle potential frequency, thoracic and ambient temperature were simultaneously measured during heating in individual workers and drones of honey bees. Relationships between these parameters and effects of thoracic temperature on power input and temperature elevation were studied. Oxygen consumption increased above basal levels only when flight muscles became active. Increasing muscle potential frequencies correlated with elevated oxygen consumption and raised thoracic temperature. The difference between thoracic and ambient temperature and oxygen consumption were linearly related. Oxygen consumption per muscle potential (l O₂ · g _–1 ^thorax · MP^–1) was two-fold higher in drones than in workers. However, oxygen consumption for heating the thorax (l O₂ · g _–1 ^thorax · (T_th-T_a) · °C^–1) was nearly the same in workers and drones. Thoracic temperature affected the amount of oxygen consumed per muscle potential (R₁₀=1.5). Achieved temperature elevation per 100 MP was more temperature sensitive in drones (R₁₀=6–10) than in workers (R₁₀=3.6). Q₁₀ values for oxygen consumption were 3 in workers and 4.5–6 in drones. Muscle potential frequency decreased with a Q₁₀=1.8 in workers and 2.7 in drones. Heating behaviour of workers and drones was different. Drones generated heat less continuously than workers, and showed greater interindividual variability in predilection to heat. However, the maximal difference between ambient and thoracic temperature observed was 22 °C in drones and 14 °C in workers, indicating greater potential for drones.Abbreviations DL dorsal-longitudinal muscle - DV dorsoventral muscle - MP muscle potential - T _a ambient temperature - T _th thoracic temperature     

Effect of microwave radiation on permeability of liposomes. Evidence against non-thermal leakage

The effect of 2.45 GHz microwave radiation on the permeability of unilamellar phosphatidylcholine liposomes has been studied. Leakage of 5(6)-carboxyfluorescein from the liposomes was measured using spectrofluorimetry after exposure to either microwaves or thermal heating for 5–20 min intervals. The exposure temperature, 37.6 ± 0.5°C, was well above the phase transition temperature of the lipid membrane. The microwave exposure did not result in any non-thermal increase in permeability above that produced by thermal heating. This study refutes the results reported by Saalman et al. [1] in which an increased liposome permeability due to microwave exposure was reported. The refined analysis in the present study shows that this increased liposome permeability was not a non-thermal microwave effect.