Effects of modafinil on working memory processes in humans

Rationale Modafinil is a well-tolerated psychostimulant drug with low addictive potential that is used to treat patients with narcolepsy or attention deficit disorders and to enhance vigilance in sleep-deprived military personal. So far, understanding of the cognitive enhancing effects of modafinil and the relevant neurobiological mechanisms are incomplete.Objectives The aim of this study was to investigate the effects of modafinil on working memory processes in humans and how they are related to noradrenergic stimulation of the prefrontal cortex.Methods Sixteen healthy volunteers (aged 20–29 years) received either modafinil 200 mg or placebo using a double blind crossover design. Two computerized working memory tasks were administered, a numeric manipulation task that requires short-term maintenance of digit-sequences and different degrees of manipulation as well as delayed matching task that assesses maintenance of visuo-spatial information over varying delay lengths. The battery was supplemented by standardized paper pencil tasks of attentional functions.Results Modafinil significantly reduced error rates in the long delay condition of the visuo-spatial task and in the manipulation conditions, but not in the maintenance condition of the numeric task. Analyses of reaction times showed no speed-accuracy trade-off. Attentional control tasks (letter cancellation, trail-making, catch trials) were not affected by modafinil.Conclusions In healthy volunteers without sleep deprivation modafinil has subtle stimulating effects on maintenance and manipulation processes in relatively difficult and monotonous working memory tasks, especially in lower performing subjects. Overlapping attentional and working memory processes have to be considered when studying the noradrenergic modulation of the prefrontal cortex.     

Long-term prognostic significance of HER-2/<Emphasis Type="Italic">neu</Emphasis> in untreated node-negative breast cancer depends on the method of testing

Introduction  

The prognostic significance of HER-2/neu in breast cancer is a matter of controversy. We have performed a study in 101 node-negative breast cancer patients with long-term follow-up not treated in the adjuvant setting, and analysed the prognostic significance of immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH), both separately and in combination, in comparison with traditional prognostic factors.     

Different proliferative and apoptotic activity in peripheral versus central parts of human uterine leiomyomas

OBJECTIVE: To determine whether there are differences in proliferative and apoptotic activity and in expression of sex steroid receptors between central and peripheral parts of human uterine leiomyomas in different menstrual cycle phases. METHODS: Biopsy specimens of the myometrium and peripheral and central parts of uterine leiomyomas were obtained from 15 women in the proliferative phase and 8 women in the secretory phase. Mitotic cells were detected by immunohistochemical staining for Ki67. Apoptotic cells were detected by the TUNEL method. Mitotic and apoptotic indexes were calculated. Tissue levels of oestrogen and progesterone receptors were measured using a commercial monoclonal receptor enzyme immunoassay kit. RESULTS: During the secretory phase the mitotic index was significantly higher in the peripheral than in the central parts of the leiomyomas. During the proliferative phase the apoptotic index was significantly higher in the peripheral compared with the central parts. These differences were not reflected by differences in receptor expression. CONCLUSIONS: The results of this study suggest that the growth of a human uterine leiomyoma mainly occurs in the peripheral parts of the tumour, during the secretory phase of the menstrual cycle. The findings emphasise the importance of being consistent when taking samples for research work.     

Postsynaptic application of a cAMP analogue reverses long-term potentiation in hippocampal CA1 pyramidal neurons

The molecular mechanisms that underlie the maintenance of long-term potentiation (LTP) remain unclear. We have examined the influence of postsynaptic cAMP-dependent processes on LTP maintenance in CA1 hippocampal cells. After LTP induction, drugs affecting cAMP-dependent processes were perfused into the cell through a patch pipette. A cAMP analogue, Rp-cAMPS (4 mM), dramatically decreased the amplitude of potentiated synaptic responses. The amplitude of responses in the control pathway was also decreased but to a lesser extent, indicating a specific effect on the potentiation process. This specific effect was not due to the larger amplitude of potentiated responses, was not use-dependent and, unlike other factors that affect LTP maintenance, did not depend on the delay (2, 10, or 25 min) of drug application after LTP induction. Lower concentrations of Rp-cAMPS (1.0 and 0.4 mM) also produced an inhibitory effect but reduced the LTP and control pathways comparably. One possible action of Rp-cAMPS is competitive inhibition of protein kinase A (PKA). Surprisingly, a potent and noncompetitive PKA inhibitor, regulatory type II subunit of PKA, produced only a weak depression of potentiated and control responses indicating there must be other targets for Rp-cAMPS. Moreover, Sp-8-OH-cAMPS, which is an activator of PKA, and Rp-8-OH-cAMPS, which is a weak inhibitor of PKA, both produced effects similar to those of Rp-cAMPS. We conclude that there are postsynaptic cyclic nucleotide-dependent processes that can specifically alter the mechanisms that maintain LTP and that are not primarily dependent on PKA.     

Invasive and non-invasive monitoring of hepatitis C virus-induced liver fibrosis: alternatives or complements?

Chronic hepatitis C virus (HCV) infection results in the development of liver fibrosis and cirrhosis in 20 to 25% of patients. The main task of the physician when examining a patient with a verified HCV infection is to identify the activity of inflammatory and necrotic processes in the liver, as well as the stage of fibrosis, and the reversibility of detected changes. Along with other clinical and laboratory parameters, this plays a major role in forecasting the course of hepatitis, as well as determines the therapeutic approach in each specific case. Liver biopsy remains the best way to assess the severity of chronic hepatitis C. The risk of developing cirrhosis depends on the stage (degree of fibrosis) and the grade (degree of inflammation and necrosis) observed in the initial liver biopsy. Non-invasive diagnostic approaches attempt to evaluate the serum markers of fibrogenesis. Biochemical markers of fibrosis scoring include thrombocyte counts, the prothrombin time, ratio of alaninaminotransferase (ALT) and aspartataminotransferase (AST) levels, the level of g-glutamyl transferase and the quantity of blood serum albumin. Another set of markers is based on the detection of molecular junctions that activate fibrosis, or participate in the generation of the liver extracellular matrix. The most applicable include hyaluronic acid (HA), type IV collagen (IV-C), N-terminal propeptide of type III procollagen (PIIIP), metalloproteinases (MMP), inhibitors of metalloproteinases (TIMP), and growth-transforming factor betta (GTFbeta). The review discusses the clinical significance of each of the criteria and possibility of their combination in the non-invasive monitoring of liver fibrosis.     

The Aging Males' Symptoms (AMS) scale: Update and compilation of international versions

Background

The interest of clinical research in aging males increased in recent years and thereby the interest to measure health-related quality of life (HRQoL) and symptoms of aging men. The Aging Males' Symptoms scale (AMS) became the most commonly used scale to measure HRQoL and symptoms in aging males in many countries worldwide. The aim of this paper is to review the current state of the instrument particularly concerning versions of the scale in different languages in the light of the quality of the translation process.

AMS versions available

Most of the translations were performed following international methodological recommendations for linguistic & cultural adaptation of HRQoL instruments. Mainly the English version was used as source language for the translation into Dutch, Spanish, Portuguese, Italian, Swedish, and Japanese (attached as additional PDF-files). Preliminary versions that were derived only from forward translations are of secondary quality and available in Finnish, Flemish, and Russian. It is recommended to complete the translation process for the latter languages before using them in international studies.

Translations in process

The AMS scale is in the process of consensus finding of two existing French versions, and the versions in the Korean, Thai, and Indonesian languages have not yet been completed in the translation process.

Conclusion

The AMS scale is obviously a valuable tool for assessing health related quality of life in aging men, because it is used worldwide. It is a standardized scale according to psychometric norms. Most of the currently available language versions were translated following international standards for linguistic and cultural translation of quality of life scales. Assistance is offered to help interested parties in the translation process.     

New lupane derived compounds with pro-apoptotic activity in cancer cells: synthesis and structure-activity relationships

Cellular screening of various synthetic triterpenoid compounds formally derived from lupane has identified a number of analogues as potential anticancer drug candidates. Here we describe the synthesis and structure-activity relationships of betulin and betulinic acid derivatives containing an E-ring modified with different oxygen functions. Thus compounds containing the lup-18-en-21-one, lup-18-ene-21,22-dione, 18,19-secolupane, and the highly oxygenated 18,19-secolupane systems, as well as des-E-lupane derivatives, were prepared from the readily available natural pentacyclic triterpene betulin using oxidative procedures. These compounds were named betulinines. We demonstrate that only selected compounds, particularly those containing a lupane E-ring-derived unsaturated ketone or diketone function, possessed in vitro cytotoxic activity against tumor cell lines, suggesting a structure-activity relationship.     

Interplay between high energy impulse noise (blast) and antioxidants in the lung

High-energy impulse noise (BLAST) is a physical event characterized by an abrupt rise in atmospheric pressure above ambient lasting for a very short period, but potentially causing significant material and biological damage. Exposure to high-level BLAST can be destructive and lethal. Low-level BLAST similar to what is encountered repeatedly by military personnel during training and combat from detonation of munitions and firing of large caliber weapons, and during occupational use of explosives and some heavy machinery, can also cause significant injury. Globally, civilians are increasingly exposed to BLAST resulting from terrorist bombings or abandoned unmarked mines following numerous wars and conflicts. We have shown previously in several animal models that exposure to non-lethal BLAST results in pathological changes, mostly to the hollow organs characterized in the lungs, the most sensitive organ, by rupture of alveolar septa, and pulmonary hemorrhage and edema. These events potentially can cause alveolar flooding, respiratory insufficiency and adult respiratory distress syndrome (ARDS), leading to varying degrees of hypoxia, antioxidant depletion and oxidative damage. We have also observed progressive formation of nitric oxide in blood and other tissues. The totality of these observations supports our general hypothesis that exposure to BLAST can lead to antioxidant depletion and oxidative damage. Understanding the mechanism(s) of BLAST-induced oxidative stress may have important implications that include a potential beneficial role for antioxidants as a prophylaxis or as secondary treatment of injury after exposure alongside other protective and therapeutic modalities. In addition, it suggests a role for endogenous nitric oxide in the injury. This report reviews experimental evidence of BLAST-induced antioxidant depletion, and the potential benefit from antioxidant supplementation before exposure.