Synthesis and preliminary anticancer activity studies of C4 and C8-modified derivatives of catechin gallate (CG) and epicatechin gallate (ECG).

We have developed an improved and reliable method for stereoselective functionalization at C4 of naturally occurring (+)-catechin. Our method utilizes DDQ oxidation followed by trapping of the quinonemethide intermediate with allyl alcohol. The quinonemethide intermediate can be regenerated from the allyl ether by exposure to boron trifluoride diethyl etherate.

Gastrin - active participant or bystander in gastric carcinogenesis?

Gastrin is a pro-proliferative, anti-apoptotic hormone with a central role in acid secretion in the gastric mucosa and a long-standing association with malignant progression in transgenic mouse models. However, its exact role in human gastric malignancy requires further validation. Gastrin expression is tightly regulated by two closely associated hormones, somatostatin and gastrin-releasing peptide, and aspects of their interaction may be deregulated during progression to gastric adenocarcinoma.

Chemistry, photophysics, and ultrafast kinetics of two structurally related Schiff bases containing the naphthalene or quinoline ring.

The two structurally related Schiff bases, 2-hydroxynaphthylidene-(8-aminoquinoline) (HNAQ) and 2-hydroxynaphthylidene-1(')-naphthylamine (HNAN), were studied by means of steady-state and time resolved optical spectroscopies as well as time-dependent density functional theory (TDDFT) calculations. The first one, HNAQ, is stable as a keto tautomer in the ground state and in the excited state in solutions, therefore it was used as a model of a keto tautomer of HNAN which exists mainly in its enol form in the ground state at room temperature. Excited state intramolecular proton transfer in the HNAN molecule leads to a very weak (quantum yield of the order of 10(-4)) strongly Stokes-shifted fluorescence.

Sex differences in brain control of prosody.

Affective (emotional) prosody is a neuropsychological function that encompasses non-verbal aspects of language that are necessary for recognizing and conveying emotions in communication, whereas non-affective (linguistic) prosody indicates whether the sentence is a question, an order or a statement. Considerable evidence points to a dominant role for the right hemisphere in both aspects of prosodic function. However, it has yet to be established whether separate parts of the right hemisphere are involved in processing different kinds of emotional intonation.

Helicobacter pylori can induce heparin-binding epidermal growth factor expression via gastrin and its receptor.

Both gastrin and Helicobacter pylori have been shown capable of up-regulating gene expression and protein shedding of heparin-binding epidermal growth factor (HB-EGF). Furthermore, the bacteria have previously been shown to induce serum hypergastrinemia in infected individuals. The aim of this work was to assess the extent to which the ability of H.

Sex differences in perception of emotion intensity in dynamic and static facial expressions.

Most research on the perception of emotional expressions is conducted using static faces as stimuli. However, facial displays of emotion are a highly dynamic phenomenon and a static photograph is its very unnatural representation. The goal of the present research was to assess the role of stimuli dynamics as well as subjects' sex in the perception of emotional expressions.

Enol-keto tautomerism of aromatic photochromic Schiff base N,N'-bis(salicylidene)-p-phenylenediamine: ground state equilibrium and excited state deactivation studied by solvatochromic measurements on ultrafast time scale.

A photochromic symmetric Schiff base, N,N'-bis(salicylidene)-p-phenylenediamine, is proposed as a probe for the study of solvent dependent enol-keto tautomerism in the ground and excited states. The ground state equilibrium between the enol-keto tautomers is found to depend mainly not on polarity but on the proton donating ability of the solvent. Upon selective excitation of each of these tautomers, the same excited state of a keto tautomer is created: in enol, after the ultrafast excited state intramolecular proton transfer (ESIPT), reaction, and in keto tautomer, directly.

Gastrin enhances the angiogenic potential of endothelial cells via modulation of heparin-binding epidermal-like growth factor.

This study examined whether gastrin modulates endothelial cell activity via heparin-binding epidermal growth factor-like growth factor (HB-EGF) expression. Human umbilical vascular endothelial cells (HUVEC) were assessed for tubule formation in the presence of amidated gastrin-17 (G17) and glycine-extended gastrin-17 (GlyG17) peptides. HB-EGF gene and protein expressions were measured by quantitative reverse transcription-PCR, immunocytochemistry, and Western blotting, and HB-EGF shedding by ELISA.

Latencies of stimulus-driven eye movements are shorter in dyslexic subjects.

Eye movements latencies toward peripherally presented stimuli were measured in 10-year-old dyslexic and control children. Dyslexic subjects, previously found to be oversensitive to stimulation of the magnocellular channel, showed reduced latencies as compared to normally reading controls. An attention shifting task was also used which showed no group differences in latencies of eye movements.

Tagged polymerase chain reaction subtractive hybridization for the enrichment of phage display random peptide libraries.

Affinity selection of phage display peptide libraries is routinely used for isolating peptides capable of binding a range of molecules, including antibodies and receptors. This process is most successful when the selecting molecule is relatively pure, for example, a monoclonal antibody. However, isolation of peptides able to bind to target molecules present in a complex mixture is more difficult because the affinity selection process isolates peptides capable of binding to all molecules present in the mixture.

The cloning of sequences differentially transcribed during the induction of somatic embryogenesis in cucumber (Cucumis sativus L.).

Somatic embryogenesis in cucumber cell suspension culture is a convenient tool to study differential gene expression, particularly during the early stages of this process. In this study, we used the cucumber somatic embryogenesis system to detect genes that were differentially transcribed during the induction of embryo development. We identified and cloned 120 candidate cDNA fragments from differential display gels.

The biological and therapeutic importance of gastrin gene expression in pancreatic adenocarcinomas.

The gastrin gene is expressed widely in pancreatic adenocarcinomas and the study aimed to assess its role in both the resistance of cancer cells to apoptosis and the sensitivity of cells to chemotherapeutic agents. Two human pancreatic cell lines, PAN1 and BXPC3, expressed gastrin at both the RNA and protein levels and are shown to be representative of human pancreatic adenocarcinomas in terms of gastrin expression. Inhibition of endogenous gastrin production by tumor cells was achieved with neutralizing gastrin antiserum and transfection with a gastrin antisense plasmid.

Attentional deficit in dyslexia: a general or specific impairment?

Dyslexic and control children were tested in a visuomotor attentional task, which provides independent measures of the alerting, orienting and conflict components of the attentional system. Our results show that dyslexics are impaired with respect to controls in the attentional conflict component (resolution of conflict of incongruent peripheral information), while the alerting and orienting components remain preserved. It excludes an overall attentional impairment and points to more specific attentional processing difficulty i.

The role of the human ventromedial prefrontal cortex in memory for contextual information.

There is a growing body of evidence that the ventromedial prefrontal cortex (VMPFC) is implicated in the new learning of visual items. Little is known, however, as to the involvement of that portion of the prefrontal cortex in the learning of temporal and spatial relationship of those items. The aim of the present study, therefore, was to investigate the role of the VMPFC in memory for temporal and spatial order.

[The effect of estrogen on cognitive processing].

The so-called female sex hormone, estrogen, is best known for its crucial involvement in reproductive cycle. Recent research revealed that estrogen also plays a significant neuromodulatory and neuroprotective role. Evidence from clinical and experimental studies show that estrogen modulates specific cognitive functions such as memory and learning.

[Vascular flow in patients with retinal detachment in the color Doppler's ultrasonography].

Unlabelled: For many years now Doppler's ultrasonography has been broadly applied in ophthalmology. Recently it has been communicated, that there is a possibility of assessing the disorders of retinal circulation in the process of retinal detachment.

Purpose: Our research had to establish, whether after the scleral buckling treatments executed due to the retinal detachment, there is a change in the blood flow in the vessels of the eyeballs.

Memory for object and object-location after lesions to the ventromedial prefrontal cortex in humans.

The aim of the present study was to investigate the effect of small unilateral lesions to the ventromedial portion of the prefrontal cortex on two memory functions: memory for objects and memory for object locations. Patients, who had undergone surgery of the anterior communicating artery aneurysm, and normal control subjects, participated in the study. The patients were subdivided into two groups: with and without unilateral resection of the gyrus rectus.

Luminance and chromatic contrast sensitivity in dyslexia: the magnocellular deficit hypothesis revisited.

The hypothesis of a magnocellular channel deficit in dyslexia was tested. Subjects were 10-year-old dyslexics and normal readers. Psychophysical thresholds for luminance and chromatic contrasts were estimated using black and white and red and green sinusoidal gratings of various spatial frequencies, presented in static and dynamic conditions (drift and reversal).

Masculinity, femininity, and transsexualism.

This study examined the relationship between sex role and gender identity in a Polish transsexual population where, unlike in Western countries, male-to-female (MF) transsexualism is much less common than female-to-male (FM) transsexualism. One hundred and three FM (82 primary, 21 secondary) and 29 MF (16 primary, 13 secondary) transsexuals plus 135 control males (CM) and 303 control females (CF) completed a Sex Role Inventory, which measures sex-role identification, that is, the degree to which one self-identifies with masculine and feminine characteristics. Data obtained from primary transsexuals revealed that, on a femininity scale, MF transsexuals scores exceeded not only CM but also CF.

Effect of combination therapy (ribavirin and interferon) in HCV-related glomerulopathy.

Background: Hepatitis C virus (HCV) is a major cause of acute and chronic hepatitis throughout the world. Several extrahepatic manifestations, including glomerulonephritis, have been reported to be associated with this type of infection. Cryoglobulinaemic and non-cryoglobulinaemic membranoproliferative glomerulonephritis (MPGN) and membranous nephropathy (MN) are the commonest lesions associated with HCV.

A comprehensive study of the association between hepatitis C virus and glomerulopathy.

Background: Hepatitis C virus (HCV)-related infection is commonly associated with a wide range of glomerulonephritides (GN) including membranoproliferative glomerulonephritis (MPGN). The causal link between HCV infection and renal disease has been postulated through the induction of cryoglobulinaemia and secondary GN. However, the detection of viral particles or genomes within the kidneys of HCV-infected patients has proved to be difficult.

Evolutionary trends of the first hypervariable region of the hepatitis C virus E2 protein in individuals with differing liver disease severity.

Hepatitis C virus (HCV) exists as a complex swarm of genetically related viruses known as a quasispecies. Recent work has shown that quasispecies complexity and evolutionary rates are associated with the outcome of acute infection. Knowledge of how the virus population evolves at different stages of chronic infection is less clear.

Direct ex vivo comparison of the breadth and specificity of the T cells in the liver and peripheral blood of patients with chronic HCV infection.

The role of intrahepatic lymphocytes in the control of hepatitis C virus (HCV) infection and the pathology associated with it is not understood; most studies of the immunology of this infection use peripheral blood lymphocyte populations. To address this further, we examined in detail the IHL from HCV-infected patients and controls, focusing on the antigen-specific CD8(+) T lymphocyte component. Individual T cells from needle liver biopsies and peripheral blood were isolated from patients with chronic HCV infection and examined directly ex vivo.

Subjective contour illusion: sex-related effect of unilateral brain damage.

The aim of the study was to investigate the effect of unilateral brain lesions on the perception of subjective contours. Brain damage resulted in a reduced ability to perceive the illusion. The effect, however, was hemisphere and sex dependent.

Evidence for the involvement of the ventro-medial prefrontal cortex in a short-term storage of visual images.

The purpose of this study was to clarify the role of the ventro-medial prefrontal cortex in short-term visual memory. Patients with focal lesions to the right gyrus rectus were impaired on a size judgement task, which required short-term retention of laterally presented visual patterns. The impairment was most evident when the stimuli were addressed to the damaged hemisphere (left visual field presentations) and when separated by very short (50-500 ms) intervals.