Pentacyclic steroids,part XVI,studies on the total syntheses of racemic 1,6-dithiabenz[3,4]estra-3, 5(10),8,14-tetraen-17-one and its D-homo analogue

The total syntheses of racemic 1,6-dithiabenz[3,4]-estra-3,5(10), 8,14-tetraen-17-one [VII]and 1,6-dithiabenz-[3,4]-D-homoestra-3,5(10),8,14-tetraen-17a-one [IX]starting fron isothiochroman-4-one [I]are described.     

Reproductive strategies in female polar and deep-sea bobtail squid genera <Emphasis Type="Italic">Rossia</Emphasis> and <Emphasis Type="Italic">Neorossia</Emphasis> (Cephalopoda: Sepiolidae)

Female reproductive features have been investigated in five polar and deep-sea bobtail squid genera Rossia and Neorossia (R. macrosoma, R. moelleri, R. pacifica, N.c. caroli and N.c. jeannae). These species are characterized by asynchronous ovary maturation, very large eggs (>10% ML), fecundity of several hundred oocytes, very high reproductive output, and continuous spawning with low batch fecundity. This adaptive complex of reproductive traits evolved in these small animals as an optimum strategy for polar and deep-water habitats.     

Identification of carbonylated peptides by tandem mass spectrometry using a precursor ion-like scan in negative ion mode

Reactive oxygen species (ROS) can oxidize proteins at almost any amino acid residue. Whereas some modifications are reversible within the cells, the higher oxidation states are especially irreversible. These irreversible post translational modifications are widely used as biomarkers of oxidative stress, such as protein carbonylation, which refers to aldehydes, ketones and lactams as 'reactive carbonyl groups'. This study relied on a set of synthetic peptides containing a C-terminal aldehyde (arginal) or modification with pyruvic acid (ketone) or 4-hydroxynonenal (aldehyde) at lysine or histidine residues, as well as peptides containing pyroglutamic acid (oxidation product of proline) and 2-amino-3-butyric acid (oxidation product of threonine). The carbonylation sites were specifically derivatized with 2,4-dinitrophenylhydrazine (DNPH) and the fragmentation behavior of the products investigated in electrospray ionization (ESI-) MS. Importantly, the DNPH-labeled carbonylated peptides showed favorable ionization behaviors in negative ion mode ESI, providing a sensitive detection method. Regular peptides were mostly discriminated under these conditions. Among the fragmentation techniques tested for the negatively charged ions, pulsed Q dissociation provided three diagnostic ions at m/z values 152.0, 163.1 and 179.0, specific for DNPH-modified peptides. These marker ions were successfully applied to detect the carbonylated model peptides in a spiked tryptic digest of bovine serum albumin and a complex protein mixture obtained from HeLa cells.     

Impact of experimental trauma and niflumic acid administration on antimicrobials' concentration in serum and mandible of rats

Administration of antibiotics and analgesics in surgery or trauma is of great importance for an effective treatment. Trauma, as stress stimulus, causes alterations in various functions of the organism as well as in drug pharmacokinetics. The aim of this study was to determine the effect of trauma upon the serum and bone levels of the antimicrobial ampicillin and cefapirin, with and without co-administration of a non-steroidal anti-inflammatory analgesic (NSAIDs). Fifty-six male Wistar rats were divided into two groups A (control) and B (experimental). Each group consisted of 4 subgroups (n=7) receiving ampicillin, ampicillin with niflunic acid, cefapirin, and cefapirin with niflunic acid. In group B traumatic injury was performed by incision (7 mm length) in the right cheek. The levels of the antibiotics were estimated by the inhibition zone of B. subtilis. An increase in antibiotic levels was observed in group B, being statistically significant only for cefapirin level in the mandible. Upon niflumic acid co-administration a statistically significant rise in serum ampicillin and mandible cefapirin levels was observed in both control and experimental groups (student t-test). It can be concluded that the combination of antibiotics and non-steroid antiinflammatory drugs (NSAIDs) may enhance the antibacterial drug concentration.     

Effect of Trichodesma indicum extract on cough reflex induced by sulphur dioxide in mice.

The effect of methanol extract of whole plants of Trichodesma indicum R. Br. has been investigated on sulphur dioxide (SO2) induced cough reflex in Swiss albino mice. The extract has demonstrated significant (p < 0.001) inhibition in frequency of cough in all the tested doses when compared with untreated control group. The effect persisted up to 90 min of its oral administration and also comparable to that of the effect exhibited by the standard drug (Codeine phosphate). This study confirmed the traditional use of this plant in the treatment of cough. Determination of underlying mechanism of beneficial effect is major topic requiring further comprehensive investigation.     

Delay of Membrane Lipid Degradation by Calcium Treatment during Cabbage Leaf Senescence

Cabbage leaf discs (Brassica oleracea L., Capitata group) were floated adaxial side up in 0, 0.05, or 0.25 m CaCl₂ solutions at 15°C for 14 d in the dark. To assess whether the delay of senescence by calcium treatment involved protection of membrane lipids, chlorophyll and protein content and the lipid composition of the membranes were determined during incubation. Chlorophyll and protein content decreased with time, in correlation with a reduction in the amount of phospholipids. The degree of unsaturation of phospholipids and free fatty acids decreased, whereas the ratio of sterol to phospholipid increased. The proportions of phospholipid classes did not change during senescence. The catabolism of phospholipids was delayed by 0.05 m calcium, but accelerated by 0.25 m, as compared to the untreated control. Based on the levels of the lipid intermediates, phospholipase D, phosphatidic acid phosphatase, lipolytic acyl hydrolase, and lipoxygenase appeared to be involved in the breakdown of phospholipids during senescence. Phospholipase D and phosphatidic acid phosphatase may be directly influenced by calcium. The calcium treatment apparently did not affect the activity of acyl hydrolase. Lipoxygenase, responsible for the peroxidation of the polyunsaturated fatty acids, was probably indirectly influenced by calcium. We conclude that the delay of senescence of cabbage leaf discs by calcium treatment involved protection of membrane lipids from degradation.     

Digital video combined with conventional radiography creates an excellent high-speed X-ray video system

Analysing rapid internal movement in animals requires high-speed X-ray imaging to visualise motion of bony and soft body structures. The frame rate of X-ray cinematic camera is limited to 200 frames s(-1) with a shutter speed of 1/3000s, due to the low X-ray kV, required for small animals. These rates are often too slow for analysing the rapid accelerations of which small animals are capable. Here, we present three alternative digital-video systems that can be combined with a conventional X-ray intensifier to yield excellent slow-motion images of internal body parts of small animals. Each system shows high performance for different requirements of radiographic motion analysis.     

On-Line Optical and Morphological Studies of Silver Nanoparticles Growth Formed by Nanosecond Laser Irradiation of Silver-Exchanged Silicate Glass

Silver-exchanged silicate glass has been irradiated by 532-nm pulsed Nd:YAG laser in order to locally form metallic nanoparticles. The particular interest of this process is to locally control the silver nanoparticles (NPs) growth. Silver ions are exchanged with sodium ions near the glass surface after dumping of a silicate glass few minutes in silver and sodium nitrates molten salt. A low-energy density laser exposure (0.239 J/cm²) chosen at the ablation threshold allows to observe the kinetics of the silver NPs growth according to the increasing shots number. An on-line optical measurement is carried out after each shot to identify the most important steps during the irradiation process. According to this measurement, we have determined four steps highlighted by UV/Visible spectrophotometry and we have identified the influence of located surface plasmon resonance. Three combined material analysis methods were used to understand the glass/laser interaction mechanism: we outlined the material volume variations by profilometric method, the element distribution by scanning electron microscopy and finally the structural distribution of the irradiated region by a local infrared investigation. The trend for NPs formation revealed by the UV/Visible spectrophotometry is thus explained by the formation of a ring expelled from a central hole. We highlight that the on-line extinction measurement can be used to data process the NPs evolution.     

Selective growth of malignant cells by in vitro incubation on Teflon

The selective growth of malignant cells on non-adhesive Teflon substrates is reported. Neoplastically transformed cell lines of human and murine origin proliferated on Teflon whereas similarly seeded normal non-tumorigenic cells were unable to undergo cell division and subsequent growth. This substrate should be especially useful in establishing primary cultures from human tumor material.