EDXRF quantitative analysis of chromophore chemical elements in corundum samples

Corundum is a crystalline form of aluminum oxide (Al(2)O(3)) and is one of the rock-forming minerals. When aluminum oxide is pure, the mineral is colorless, but the presence of trace amounts of other elements such as iron, titanium, and chromium in the crystal lattice gives the typical colors (including blue, red, violet, pink, green, yellow, orange, gray, white, colorless, and black) of gemstone varieties. The starting point for our work is the quantitative evaluation of the concentration of chromophore chemical elements with a precision as good as possible to match the data obtained by different techniques as such as optical absorption photoluminescence. The aim is to give an interpretation of the absorption bands present in the NIR and visible ranges which do not involve intervalence charge transfer transitions (Fe(2+) --> Fe(3+) and Fe(2+) --> Ti(4+)), commonly considered responsible of the important features of the blue sapphire absorption spectra. So, we developed a method to evaluate as accurately as possible the autoabsorption effects and the secondary excitation effects which frequently are sources of relevant errors in the quantitative EDXRF analysis.

The adenosine A2A receptor antagonist ZM241385 enhances neuronal survival after oxygen-glucose deprivation in rat CA1 hippocampal slices

BACKGROUND AND PURPOSE

Activation of adenosine A(2A) receptors in the CA1 region of rat hippocampal slices during oxygen-glucose deprivation (OGD), a model of cerebral ischaemia, was investigated.

EXPERIMENTAL APPROACH

We made extracellular recordings of CA1 field excitatory postsynaptic potentials (fepsps) followed by histochemical and immunohistochemical techniques coupled to Western blots.

KEY RESULTS

OGD (7 or 30 min duration) elicited an irreversible loss of fepsps invariably followed by the appearance of anoxic depolarization (AD), an unambiguous sign of neuronal damage. The application of the selective adenosine A(2A) receptor antagonist, ZM241385 (4-(2-[7-amino-2-{2-furyl}{1,2,4}triazolo{2,3-a}{1,3,5}triazin-5-ylamino]ethyl)phenol; 100-500 nmolxL(-1)) prevented or delayed AD appearance induced by 7 or 30 min OGD and protected from the irreversible fepsp depression elicited by 7 min OGD. Two different selective adenosine A(2A) receptor antagonists, SCH58261 and SCH442416, were less effective than ZM241385 during 7 min OGD. The extent of CA1 cell injury was assessed 3 h after the end of 7 min OGD by propidium iodide. Substantial CA1 pyramidal neuronal damage occurred in untreated slices, exposed to OGD, whereas injury was significantly prevented by 100 nmolxL(-1) ZM241385. Glial fibrillary acid protein (GFAP) immunostaining showed that 3 h after 7 min OGD, astrogliosis was appreciable. Western blot analysis indicated an increase in GFAP 30 kDa fragment which was significantly reduced by treatment with 100 nmolxL(-1) ZM241385.

CONCLUSIONS AND IMPLICATIONS

In the CA1 hippocampus, antagonism of A(2A) adenosine receptors by ZM241385 was protective during OGD (a model of cerebral ischaemia) by delaying AD appearance, decreasing astrocyte activation and improving neuronal survival.

A closer look at amphetamine-induced reverse transport and trafficking of the dopamine and norepinephrine transporters

Amphetamine (AMPH) and its derivatives are regularly used in the treatment of a wide array of disorders such as attention-deficit hyperactivity disorder (ADHD), obesity, traumatic brain injury, and narcolepsy (Prog Neurobiol 75:406-433, 2005; J Am Med Assoc 105:2051-2054, 1935; J Am Acad Child Adolesc Psychiatry 41:514-521, 2002; Neuron 43:261-269, 2004; Annu Rev Pharmacol Toxicol 47:681-698, 2007; Drugs Aging 21:67-79, 2004). Despite the important medicinal role for AMPH, it is more widely known for its psychostimulant and addictive properties as a drug of abuse. The primary molecular targets of AMPH are both the vesicular monoamine transporters (VMATs) and plasma membrane monoamine-dopamine (DA), norepinephrine (NE), and serotonin (5-HT)-transporters. The rewarding and addicting properties of AMPH rely on its ability to act as a substrate for these transporters and ultimately increase extracellular levels of monoamines. AMPH achieves this elevation in extracellular levels of neurotransmitter by inducing synaptic vesicle depletion, which increases intracellular monoamine levels, and also by promoting reverse transport (efflux) through plasma membrane monoamine transporters (J Biol Chem 237:2311-2317, 1962; Med Exp Int J Exp Med 6:47-53, 1962; Neuron 19:1271-1283, 1997; J Physiol 144:314-336, 1958; J Neurosci 18:1979-1986, 1998; Science 237:1219-1223, 1987; J Neurosc 15:4102-4108, 1995). This review will focus on two important aspects of AMPH-induced regulation of the plasma membrane monoamine transporters-transporter mediated monoamine efflux and transporter trafficking.

Finding of a bull with Y;17 translocation

A bull with a Y;17 translocation was found. This finding was examined by G banding, C banding, and studying the cytodensitometric profiles of G banding. The subject appeared phenotypically normal, with normal reproductive organs and testicular function (GnRH Test). There was a slight pathospermia (oligozoospermia and asthenozoospermia), therefore the portions of Y chromosome with TDF and AZF were not lost.

Tandem 3D-QSARs approach as a valuable tool to predict binding affinity data: design of new Gly/NMDA receptor antagonists as a key study

Quantitative structure-activity relationships (QSARs) represent a very well consolidated computational approach to correlate structural or property descriptors of chemical compounds with their chemical or biological activities. We have recently reported that autocorrelation Molecular Electrostatic Potential (autoMEP) vectors in combination to Partial Least-Square (PLS) analysis or to Response Surface Analysis (RSA) can represent an interesting alternative 3D-QSAR strategy. In the present paper, we would like to present how the applicability of in tandem linear and nonlinear 3D-QSAR methods (autoMEP/PLS&RSA) can help to predict binding affinity data of a new set of N-methyl-d-aspartate (Gly/NMDA) receptor antagonists.

Effect of nitric oxide on lymphocytes from sporadic amyotrophic lateral sclerosis patients: toxic or protective role?

Markers of oxidative and nitrosative stress have been found in spinal cord, cortex, cerebrospinal fluid and plasma of patients affected by amyotrophic lateral sclerosis (ALS), a fatal disorder characterised by progressive motor neuron degeneration. In this study, we investigated the effect of the NO-releasing agent, diethylamine NONOate (NONO), on lymphocytes from patients affected by the sporadic form of ALS (SALS) and controls by flow cytometry. In the same experimental conditions we investigated the expression of the antioxidant proteins, Bcl-2 and SOD1. Incubation with NONO induced cell damage in control lymphocytes but did not further damage the already affected untreated SALS lymphocytes. The incubation with NONO induced a time-dependent decrease of Bcl-2 and SOD1 in control lymphocytes. Surprisingly, in SALS lymphocytes the NONO treatment increased the expression of these proteins, which in basal conditions was depressed compared to control lymphocytes.

Dopamine transporter activity mediates amphetamine-induced inhibition of Akt through a Ca2+/calmodulin-dependent kinase II-dependent mechanism

The primary mechanism for clearance of extracellular dopamine (DA) is uptake mediated by the dopamine transporter (DAT), which is governed, in part, by the number of functional DATs on the cell surface. Previous studies have shown that amphetamine (AMPH) decreases DAT cell surface expression, whereas insulin reverses this effect through the action of phosphatidylinositol 3-kinase (PI3K). Therefore, it is possible that AMPH causes DAT cell surface redistribution by inhibiting basal insulin signaling. Here, we show in a heterologous expression system and in murine striatal synaptosomes that AMPH causes a time-dependent decrease in the activity of Akt, a protein kinase immediately downstream of PI3K. This effect was blocked by the DAT inhibitor cocaine, suggesting that AMPH must interact with DAT to inhibit Akt. We also showed that AMPH is able to stimulate Ca2+/calmodulin-dependent kinase II (CaMKII) activity, both in the heterologous expression system as well as in murine striatal synaptosomes. The ability of AMPH to decrease Akt activity was blocked by the CaMKII inhibitor 2-[N-(2-hydroxyethyl)]-N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine (KN93), but not by its inactive analog 2-[N-(4-methoxybenzenesulfonyl)]amino-N-(4-chlorocinnamyl)-N-methylbenzylamine (KN92). Furthermore, preincubation with KN93 prevented the AMPH-induced decrease in DAT cell surface expression. Thus, AMPH, but not cocaine, decreases Akt activity through a CaMKII-dependent pathway, thereby providing a novel mechanism by which AMPH regulates insulin signaling and DAT trafficking.

Sex ratio determination in bovine semen: A new approach by quantitative real time PCR

Sex preselection of livestock offspring in cattle represents, nowadays, a big potential for genetic improvement and market demand satisfaction. Sperm sorting by flow cytometer provides a powerful tool for artificial insemination and production of predefined sexed embryos but, an accurate verification of the yield of sperm separation remains essential for a field application of this technique or for improvement and validation of other related semen sexing technologies. In this work a new method for the determination of the proportion of X- and Y-bearing spermatozoa in bovine semen sample was developed by real time PCR. Two sets of primers and internal TaqMan probes were designed on specific X- and Y-chromosome genes. To allow a direct quantification, a standard reference was established using two plasmid cDNA clones (ratio 1:1) for the specific gene targets. The method was validated by a series of accuracy, repeatability and reproducibility assays and by testing two sets of sorted and unsorted semen samples. A high degree of accuracy (98.9%), repeatability (CV=2.58%) and reproducibility (CV=2.57%) was shown. The results of X- and Y-sorted semen samples analysed by real time PCR and by flow cytometric reanalysis showed no significant difference (P>0.05). The evaluation of X-chromosome bearing sperms content in unsorted samples showed an average of 51.11+/-0.56% for ejaculates and 50.17+/-0.58% for the commercial semen. This new method for quantification of the sexual chromosome content in spermatozoa demonstrated to be rapid and reliable, providing a valid support to the sperm sexing technologies.

Antineoplastic effects of rosiglitazone and PPARgamma transactivation in neuroblastoma cells

Neuroblastoma (NB) is the most common extracranial solid tumour in infants. Unfortunately, most children present with advanced disease and have a poor prognosis. In the present study, we evaluated the role of the peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone (RGZ) in two NB cell lines (SK-N-AS and SH-SY5Y), which express PPARγ. Rosiglitazone decreased cell proliferation and viability to a greater extent in SK-N-AS than in SH-SY5Y. Furthermore, 20 μM RGZ significantly inhibited cell adhesion, invasiveness and apoptosis in SK-N-AS, but not in SH-SY5Y. Because of the different response of SK-N-AS and SH-SY5Y cells to RGZ, the function of PPARγ as a transcriptional activator was assessed. Noticeably, transient transcription experiments with a PPARγ responsive element showed that RGZ induced a three-fold increase of the reporter activity in SK-N-AS, whereas no effect was observed in SH-SY5Y. The different PPARγ activity may be likely due to the markedly lower amount of phopshorylated (i.e. inactive) protein observed in SK-N-AS. To our knowledge, this is the first demonstration that the differential response of NB cells to RGZ may be related to differences in PPARγ transactivation. This finding indicates that PPARγ activity may be useful to select those patients, for whom PPARγ agonists may have a beneficial therapeutic effect.

A randomized phase III study: comparison between intravenous and intraarterial ACNU administration in newly diagnosed primary glioblastomas

BACKGROUND

In this randomized phase III study, the effectiveness as well as the side-effects of intraarterial [i.a.] (17 patients) versus intravenous [i.v.] (16 patients) ACNU [Nimustine] administration in newly diagnosed glioblastoma, were compared.

PATIENTS AND METHODS

All patients undenwent extensive surgical resection, and both groups were homogeneous for the other known risk factors. Thirty-three patients with glioblastoma were treated with ACNU at the dose of 80-100 mg/m2. Treatment was repeated every 5-8 weeks for a minimum of 2 and maximum of 14 cycles. Total survival time (TST) and to time to progression were chosen as outcome variables.

RESULTS AND CONCLUSION

No significant differences in systemic and hematological toxicity between the i.a. and iv. ACNU administration routes were detected. In both groups, tolerance of the procedure was excellent. Analysis of the main outcome measured showed no significant differences between i.a. and i.v. ACNU administration: time to progression was 6 months for i.a. ACNU and 4 months for i.v. ACNU and total survival time was 17 months for i.a. ACNU and 20 months for i.v. ACNU. In spite of ACNU dose incrementation, obtained through i.a. route administration, and subsequent higher concentration in the tumor bed, no improvement could be achieved in effectiveness.

Evolution of HVR-1 Quasispecies after 1-Year Treatment in HIV/HCV-Coinfected Patients According to the Pattern of Response to Highly Active Antiretroviral Therapy

Hepatitis C virus (HCV) variability is mainly attributed to the ability of the virus to respond to host immune pressure, acting as a driving force for the evolution of quasispecies. This study was aimed at studying the changes in HVR-1 heterogeneity and the evolution of HCV quasispecies in HIV/HCV-coinfected patients according to the pattern of response to highly active antiretroviral therapy (HAART).

Sixteen HIV/HCV-coinfected patients harbouring HCV genotype 1 and who had been on HAART for at least 1 year, 8 showing increasing CD4+T-cell counts (immunological responders) and 8 showing a stable or decreasing CD4+ T-cell counts (immunological non-responders), were selected from a prospective cohort study.

After 1 year of HAART, 11 patients showed HIV viral load <2.6 log10 cp/ml (virological responders), and 5 showed HIV viral load above this value (virological non-responders). Plasma samples, collected before starting therapy and after 1 year of HAART, underwent clonal sequence analysis for HVR-1 region of HCV. Non-synonymous/synonymous substitutions ratio (Ka/Ks), aminoacidic complexity (normalized Shannon entropy) and diversity (p-distance), were considered as parameters of quasispecies heterogeneity. After 1 year of HAART, heterogeneity of HVR-1 quasispecies significantly decreased in virological non-responders, whereas the heterogeneity tended to increase in virological responders. The differences in the evolution were less stringent, when considering immunological response. On the other hand, profound qualitative modifications of HVR-1 quasispecies were observed only in patients with both immunological and virological HAART response.

On the whole, these findings suggest that, in patients undergoing HAART, the extent of HCV variability and the evolution of HVR-1 quasispecies is influenced by the pattern of response to antiretroviral therapy.

The dopamine transporter: a vigilant border control for psychostimulant action

Neurotransmission within the mesocorticolimbic dopamine system has remained the central focus of investigation into the molecular, cellular and behavioral properties of psychostimulants for nearly three decades. The primary means by which dopamine transmission in the synapse is terminated is via the dopamine transporter (DAT), the presynaptic plasmalemmal protein that is responsible for the reuptake of released dopamine. Numerous abused as well as clinically important drugs have important pharmacological interactions with DAT. In general, these compounds fall into two categories: those that block dopamine transport (e.g., cocaine, methylphenidate) and those that serve as substrates for transport [e.g., dopamine, amphetamine and 3,4-methylenedioxymethamphetamine (MDMA or "ecstasy")]. Recent data from in vitro and in vivo studies have suggested that DAT, like other biogenic amine transporters, share several characteristics with classical ligand-gated ion channels. In addition, substrates for transport promote redistribution of DAT away from the plasma membrane, while transport inhibitors such as cocaine disrupt this process. In addition, presynaptic autoreceptors for dopamine have been implicated in the modulation of DAT surface expression and function. The present chapter summarizes some of the recent discoveries pertaining to the electrogenic properties of DAT and their potential relevance to the effects of amphetamine-like stimulants on DAT function. Although there are a number of intracellular and extracellular modulatory influences on dopamine clearance that may play particular roles in psychostimulant action, we specifically focus on the differential direct modulation of DAT function by transport substrates and inhibitors, and we also discusses the role of presynaptic D2 receptors in transport regulation.

Laparoscopic repair of strangulated hernias

BACKGROUND

Although laparoscopic transabdominal preperitoneal polypropylene (TAPP) hernia repair is now a recognized procedure for groin hernia repair in patients undergoing elective surgery, there is a scarcity of data on TAPP repair in emergency situations such as those involving strangulated hernias.

METHODS

Unless contraindicated, the authors' department considers laparoscopic TAPP repair the procedure of choice for all strangulated hernias. A prospective database of 1,532 consecutive hernia repairs performed between May 1998 and April 2004 was reviewed.

RESULTS

A total of 28 irreducible strangulated hernias were observed and repaired through laparoscopic TAPP. There were three conversions (10.7%): one because of extensive adhesions and two because of bowel distention. Resection became necessary in 9 (36%) of the 25 cases involving effective TAPP repair of strangulated hernias. The mean operation time, with and without resection, was 103 and 55 min, respectively. The rate of postoperative morbidity was 4% because of one inguinal hematoma case. During a mean follow-up period of 340 days, there were no recurrences after TAPP repair.

CONCLUSIONS

For selected patients, the TAPP approach appears to be a good therapeutic option for strangulated hernias.

Natural Killer-Cell Cytotoxicity in HIV-Positive and HIV-Negative Patients with and Without Severe Course of Hepatitis B Virus Infection

Natural killer (NK) cells represent the first line of defence against viral infections but, in the case of hepatitis B virus (HBV), may also be involved in liver injury. We here compared NK-cell activity of 11 patients with acute HBV infection, either HIV-positive or HIV-negative, with that of 11 healthy subjects. One of the HIV-positive patients, characterized by a severe immunodeficiency, died 3 weeks after hospitalization for HBV-related fulminant hepatitis (FH). He displayed a remarkable NK-cell cytotoxicity against both cell lines and autologous dendritic cells, whereas the NK-cell activity of the remaining patients was significantly reduced as compared with healthy individuals. Our findings suggest that NK-cell-mediated cytotoxicity could contribute to the development of HBV-related acute liver failure in HIV-positive patients with severe immunodeficiency. An immunopathological model of FH in immunocompromised patients was proposed.