Biomedical subjects

Anna Grabowska

Publications and source records attributed to Anna Grabowska.

15 recordsLinked to original sources

PubMed2006

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. The aim of this study was to answer this question. In addition, the issue of sex differences in the ability to understand prosody was considered. Fifty-two patients with damage to frontal, temporo-parietal or subcortical (basal) parts of the right hemisphere and 26 controls were tested for their ability to assess prosody information in normal (well-formed) sentences and in pseudo-sentences. General impairment of prosody processing was seen in all patient groups but the effect of damage was more apparent for emotional rather than linguistic prosody. Interestingly, appreciation of emotional prosody appeared to depend on the type of emotional expression and the location of the brain lesion. The patients with frontal damage were mostly impaired in comprehension of happy intonations; those with temporo-parietal damage in assessment of sad intonations, while subcortical lesions mostly affected comprehension of angry intonations. Differential effects of lesion location on the performance of men and women were also observed. Frontal lesions were more detrimental to women, whereas subcortical lesions led to stronger impairment in men. This suggests sex differences in brain organization of prosodic functions.

Affect↗

PubMed2006

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. pylori to up-regulate expression of HB-EGF can be attributed to its effect on gastrin. Gastric cells, transfected with either gastrin small interfering RNA or antisense plasmid or the gastrin/cholecystokinin-2 receptor (CCK-2R), were cultured for 24 hours with H. pylori(+/-), a CCK-2R antagonist. Gene expression levels were measured using reverse transcription-PCR, whereas protein changes were measured using ELISA, Western blotting, and immunofluorescence. H. pylori induced significantly higher levels of HB-EGF gene expression and ectodomain shedding in the CCK-2R-transfected cells than the vector control (P < 0.01). Addition of the CCK-2R inhibitor significantly decreased gene and shedding up-regulation. Gastrin down-regulation reduced the effect of the bacteria on HB-EGF gene and protein expression levels. Endogenous gastrin and CCK-2R expression were also found to be significantly up-regulated in all cell lines as a result of exposure to H. pylori (P < 0.02). Gastric mucosal tissue from H. pylori-infected individuals had significantly higher CCK-2R expression levels than noninfected (P < 0.003), and in hypergastrinemic mice, there was an increase in HB-EGF-expressing cells in the gastric mucosa and colocalization of HB-EGF with CCK-2R-positive enterochromaffin-like cells. In conclusion, gastrin and the CCK-2R play significant roles in the induction of HB-EGF gene and protein expression and ectodomain shedding by H. pylori.

Adenocarcinoma↗

PubMed2006

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. Matrix metalloproteinases MMP-2, MMP-3, and MMP-9 were assessed by Western blotting. Chick chorioallantoic membrane studies measured the in vivo angiogenic potential of gastrin and microvessel density (MVD) was assessed in large intestinal premalignant lesions of hypergastrinaemic APC(Min) mice. MVD was also examined in human colorectal tumor and resection margin normals and correlated with serum-amidated gastrin levels (via RIA) and HB-EGF protein expression (via immunohistochemistry). HUVEC cells showed increased tubule and node formation in response to G17 (186%, P < 0.0005) and GlyG17 (194%, P < 0.0005). This was blockaded by the cholecystokinin-2 receptor (CCK-2R) antagonists JB95008 and JMV1155 and by antiserum to gastrin and HB-EGF. Gastrin peptides increased HB-EGF gene expression/protein secretion in HUVEC and microvessel-derived endothelial cells and the levels of MMP-2, MMP-3, and MMP-9. G17 promoted angiogenesis in a chorioallantoic membrane assay, and MVD was significantly elevated in premalignant large intestinal tissue from hypergastrinaemic APC(Min) mice. In terms of the clinical situation, MVD in the normal mucosa surrounding colorectal adenocarcinomas correlated with patient serum gastrin levels and HB-EGF expression. Gastrin peptides, acting through the CCK-2R, enhance endothelial cell activity in models of angiogenesis. This may be mediated through enhanced expression and shedding of HB-EGF, possibly resulting from increased activity of matrix metalloproteinases. This proangiogenic effect translates to the in vivo and human situations and may add to the tumorigenic properties attributable to gastrin peptides in malignancy.

Animals↗

PubMed2006

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. Then some part (<30%) of excited molecules are transferred to the photochromic form in its ground state. The evidence of another ultrafast deactivation channel in the excited enol tautomer competing with ESIPT has been found. The solvent does not influence the ESIPT dynamics nor the efficiency of the creation of the photochrome.

Journal Article↗

PubMed2006

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. In the experiment, subjects rated the intensity of expressions of anger and happiness presented as photographs (static stimuli) and animations (dynamic stimuli). The impact of both stimulus dynamics and emotion type on the perceived intensity was observed. The emotions on 'angry faces' were judged as more intense than on 'happy faces' and the intensity ratings were higher in the case of animation rather than photography. Moreover, gender differences in the rated intensity were found. For male subjects higher intensity ratings for dynamic than for static expressions were noted in the case of anger, whereas in the case of happiness, no differences were observed. For female subjects, however, differences for both anger and happiness were significant. The results suggest that the dynamic characteristic of facial display is an important factor in the perception of the intensity of emotional expressions. Its effect, however, depends on the subjects' sex and emotional valence.

Adult↗

PubMed2005

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. The data are discussed in terms of the hypothesis of magnocellular system alteration and attention dysfunction in dyslexia. Additionally, sex differences in eye movement latencies were found and are discussed.

Attention↗

PubMed2004

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.e. distributed attention strategy. Generally, results of dyslexic boys are within the range of the control group, while reaction times of dyslexic girls are significantly slower than that of all other groups.

Analysis of Variance↗

PubMed2004

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. Patients who had undergone surgery of the anterior communicating artery aneurysm, and normal control subjects (C), participated in the study. The patients were subdivided into three groups: with resection of the left (LGR+) or right (RGR+) gyrus rectus, and without such a resection (GR-). Subjects were presented with two memory tests: a temporal order (TO) test and a spatial order (SO) test. In the TO test, the LGR+ and RGR+ groups performed worse than the C group, while the GR- group did not differ significantly from the C group. In the SO test, the LGR+ and RGR+ groups did not differ significantly from the C and GR- groups. However, the trend appears to be the same for both tests, although only the TO test provides statistically significant group differences. Our results thus suggest that the VMPFC is involved in memory for contextual information. Together with previous findings, the data suggest that the learning of the relationship between items as well as the learning of those items are mediated by overlapping areas of the VMPFC.

Aneurysm, Ruptured↗

PubMed2003

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. Subjects were presented with two memory tests, that required remembering either simultaneously presented visual stimuli (object memory test; OMT) or locations of the stimuli (location memory test; LMT). In the OMT, patients with resection of the gyrus rectus were impaired in comparison to patients without resection and normal control subjects. In the LMT, the three groups did not differ from each other. Our results suggest that the ventromedial prefrontal cortex is specifically involved in memory for objects.

Adult↗

PubMed2003

[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. MATERIAL AND METHODS: The observations were conducted in 30 eyes of 15 people, who were diagnosed with opening-related retinal detachment. The colour Doppler's ultrasonography was performed by using ATL Ultramark 9HDI apparatus with a linear sound of the frequency range from 7.5 to 10 MHz. The anatomic structures of the eye socket in the transverse and arrow plane were assessed. The flow spectrum was measured according to the PD method (pulsating Doppler) in the central artery of the retina at the distance of approximately 2-4 mm from the optic disc and in the ophthalmic artery. The analysis of the spectrum allowed one to determine the values of the pulsation indexes-PI, and resistance indexes-RI, in the ophthalmic artery and in the central artery of the retina of the healthy eye, and of the eye with detached retina 2-3 days before and in 5-7 days after the operative procedure. RESULTS: After radial and circumferential buckling treatments, the conducted research found no increased resistance of the flow in the arteries, namely: the central artery of the retina and the ophthalmic artery. The condition for the maintenance of the correct parameters of the blood flow was the intraocular pressure. At the same time, in the eyes with detached retina, the decrease in the resistance of the flow in the ophthalmic artery was observed, which was being brought back to normal after the operative treatment.

Adult↗

PubMed2003

[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. There are also data suggesting its positive role for the prevention and treatment of dementia and Alzheimer's disease. The present paper presents a review of research in these fields.

Alzheimer Disease↗

PubMed2002

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). Significant group differences were found for luminance contrast, with a higher sensitivity in dyslexics. No group differences were obtained for chromatic contrast. High luminance contrast sensitivity correlated with low reading and writing skills. The typical finding of an increase contrast sensitivity to low spatial frequency gratings, due to their dynamic presentations, was absent in dyslexics. The results provide support for the magnocellular deficit hypothesis. The pattern of this deficit, however, is much more complex than that emerging from previous research.

Child↗

PubMed2002

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. On a masculinity scale, MF transsexuals rated themselves significantly lower than CM, but at a level comparable to CF. The comparison of FM transsexuals and controls showed that, on a masculinity scale, transsexuals scored higher than CF but were not different from CM. On the femininity scale, FM transsexuals rated themselves in between the two control groups: lower than CF but slightly higher than CM. The relations of secondary transsexuals' scores to CF and CM scores, on both masculine and feminine scales, were in the same direction as the primary transsexuals' scores. Secondary transsexuals rated themselves very similarly to their primary counterparts (the exception was a much higher score of MF-primary transsexuals than MF-secondary transsexuals on the femininity scale). Our study revealed that transsexualism does not imply a simple inversion of sex-role patterns: transsexuals differ not only from nontranssexual individuals of the same anatomical sex but also from those of the opposite sex. Moreover, MF transsexualism is not a mirror image of FM transsexualism: it constitutes a more extreme condition in the identification with feminine versus masculine personality traits. These differences seem to be universal for different countries and regions. The diagnostic value of our findings is discussed.

Adult↗

PubMed2002

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. Results of treatment of these patients with interferon therapy have been disappointing, since relapse of the viraemia and subsequent relapse of the renal disease are major problems. Combination of interferon with ribavirin in patients with chronic liver disease has been shown to increase the rate of sustained response. METHODS: In this work, 20 patients with HCV-associated glomerulopathy were subjected to an in-depth evaluation of their kidney lesions and HCV involvement. Laboratory, histopathological, immunohistochemical, and electron-microscopy techniques were used. The patients received interferon therapy for 12 months; in interferon-resistant subjects, interferon was combined with ribavirin. RESULTS: MPGN was the commonest kidney lesion, being reported in 85% of these cases, followed by MN and mesangioproliferative glomerulonephritis (10 and 5% respectively). Mixed cryoglobulinaemia was encountered in 60% of the cases. Twelve months' anti-viral treatment resulted in aviraemia in 25% of cases, while liver enzymes were normalized in 75%, 24-h proteinuria significantly decreased (from median 4 g to 1.10 g, P=0.001), serum albumin increased (from median 2.50 to 3.55 g/dl, P=0.012), lower viral titres (from median 1.15 to 0.53 mega-Eq/ml, P=0.049), and C3 and C4 concentrations returned to normal. Basal serum creatinine and viral titres were important determinants of response to treatment. CONCLUSION: This study supports the relationship between HCV and glomerulonephritis, especially MPGN, and the use of a combination of interferon and ribavirin in the treatment of selected cases of HCV-related glomerulopathy.

Adult↗

PubMed2002

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. With that in mind, we have studied a population of Egyptian HCV-positive patients with associated GN in an attempt to detect viral particles, antigens or RNA within their kidneys. METHODS: Fifty patients were found to be HCV positive out of 303 who presented with a glomerulopathy between 1998 and 1999 at the Mansoura Urology and Nephrology Center, Egypt. Comprehensive investigations of these 50 patients were undertaken including an evaluation of their clinical, biochemical, histological, virological and immunological parameters. In addition, their kidney biopsy material was analysed by electron microscopy (EM) to detect viral particles, by immunohistochemistry to detect a viral core antigen and by RT-PCR to detect RNA. This was compared with 50 HCV-negative controls. RESULTS: Positivity for HCV antibodies was higher among patients with GN (38%) compared with healthy blood donors (16%). Genotype 4 was sequenced in 70% of the HCV-positive samples examined. MPGN was the most common type of GN accounting for 54% of patients. Extrarenal manifestations were absent in the majority (80%) of patients even though 54% had cryoglobulinaemia. EM revealed virus-like particles in 50% of biopsies. Immunohistochemistry failed to reveal HCV-related antigens in kidney sections. HCV RNA was detected in the cryoprecipitates in 66% of patients and 22% of frozen renal sections. Control sections were negative. CONCLUSION: Our findings suggest a causal link between HCV and GN based on the observation of virus-like particles as well as viral RNA within the kidney sections of patients with HCV-associated glomerulopathies.

Antibodies, Viral↗