Roman Hauser

Bio: Roman Hauser is an academic researcher from Gdańsk Medical University. The author has contributed to research in topics: Nitric oxide synthase & Prefrontal cortex. The author has an hindex of 10, co-authored 24 publications receiving 418 citations.

Improving the resolution of neuropeptides in rat brain with on-line HILIC-RP compared to on-line SCX-RP.

Abstract: Our two already established on-line 2-D LC systems, a strong cation exchange-RP chromatography (SCX-RP) system and a hydrophilic interaction LC (HILIC)-RP 2-D LC system, were compared to explore which system is best suited for our further studies of differences in cerebral neuropeptide expression as a function of hypoxia-caused stress The same mass spectrometer and database search parameters were applied in both systems In total, 19 first dimension fractions were collected with the novel on-line HILIC-RP system, including a Hypercarb SPE column that was applied to trap the compounds not retained on a Kromasil C18 enrichment column In contrast, six fractions were collected in the SCX-RP method, due to practical limitations of this traditional on-line 2-D LC system With the on-line HILIC-RP system three times more peaks were detected It was observed that most of the compounds eluted in the first two fractions in the SCX-RP method, while in the 2-D HILIC-RP method there seemed to be no correlation between peaks detected and fraction number Thus, from this systematic study it seems that on-line HILIC-RP chromatography is the method of choice for comparative “peptidomics” of cerebral neuropeptides in future studies

Verification of the exponential model of body temperature decrease after death in pigs

Abstract: The authors have conducted a systematic study in pigs to verify the models of post-mortem body temperature decrease currently employed in forensic medicine. Twenty-four hour automatic temperature recordings were performed in four body sites starting 1.25 h after pig killing in an industrial slaughterhouse under typical environmental conditions (19.5-22.5 degrees C). The animals had been randomly selected under a regular manufacturing process. The temperature decrease time plots drawn starting 75 min after death for the eyeball, the orbit soft tissues, the rectum and muscle tissue were found to fit the single-exponential thermodynamic model originally proposed by H. Rainy in 1868. In view of the actual intersubject variability, the addition of a second exponential term to the model was demonstrated to be statistically insignificant. Therefore, the two-exponential model for death time estimation frequently recommended in the forensic medicine literature, even if theoretically substantiated for individual test cases, provides no advantage as regards the reliability of estimation in an actual case. The improvement of the precision of time of death estimation by the reconstruction of an individual curve on the basis of two dead body temperature measurements taken 1 h apart or taken continuously for a longer time (about 4 h), has also been proved incorrect. It was demonstrated that the reported increase of precision of time of death estimation due to use of a multiexponential model, with individual exponential terms to account for the cooling rate of the specific body sites separately, is artifactual. The results of this study support the use of the eyeball and/or the orbit soft tissues as temperature measuring sites at times shortly after death. A single-exponential model applied to the eyeball cooling has been shown to provide a very precise estimation of the time of death up to approximately 13 h after death. For the period thereafter, a better estimation of the time of death is obtained from temperature data collected from the muscles or the rectum.

Differences between unipolar and bipolar I depression in the quantitative analysis of glutamic acid decarboxylase-immunoreactive neuropil

Abstract: Alterations in GABAergic neurotransmission are assumed to play a crucial role in the pathophysiology of mood disorders. Glutamic acid decarboxylase (GAD) is the key enzyme in GABA synthesis. This study aimed to differentiate between unipolar and bipolar I depression using quantitative evaluation of GAD-immunoreactive (GAD-ir) neuropil in several brain regions known to be involved in the pathophysiology of mood disorders. Immunohistochemical staining of GAD 65/67 was performed in the orbitofrontal, anterior cingulate and dorsolateral prefrontal cortex (DLPFC), the entorhinal cortex, the hippocampal formation and the medial dorsal and lateral dorsal (LD) thalamic nuclei, with a quantitative densitometric analysis of GAD-ir neuropil. The study was performed on paraffin-embedded brains from 9 unipolar and 12 bipolar I depressed patients (8 and 6 suicidal patients, respectively) and 18 matched controls. In unipolar patients, compared with controls, only the increased relative density of GAD-ir neuropil in the right LD was different from the previous results in depressed suicides from the same cohort (Gos et al. in J Affect Disord 113:45–55, 2009). On the other hand, the left DLPFC was the only area where a significant decrease was observed, specific for bipolar I depression. Significant differences between both diagnostic groups were found in these regions. By revealing abnormalities in the relative density of GAD-ir neuropil in brain structures, our study suggests a diathesis of the GABAergic system in mood disorders, which may differentiate the pathophysiology of unipolar from that of bipolar I depression.

Circadian patterns of gene expression in the human brain and disruption in major depressive disorder

Abstract: A cardinal symptom of major depressive disorder (MDD) is the disruption of circadian patterns. However, to date, there is no direct evidence of circadian clock dysregulation in the brains of patients who have MDD. Circadian rhythmicity of gene expression has been observed in animals and peripheral human tissues, but its presence and variability in the human brain were difficult to characterize. Here, we applied time-of-death analysis to gene expression data from high-quality postmortem brains, examining 24-h cyclic patterns in six cortical and limbic regions of 55 subjects with no history of psychiatric or neurological illnesses (“controls”) and 34 patients with MDD. Our dataset covered ∼12,000 transcripts in the dorsolateral prefrontal cortex, anterior cingulate cortex, hippocampus, amygdala, nucleus accumbens, and cerebellum. Several hundred transcripts in each region showed 24-h cyclic patterns in controls, and >100 transcripts exhibited consistent rhythmicity and phase synchrony across regions. Among the top-ranked rhythmic genes were the canonical clock genes BMAL1(ARNTL), PER1-2-3, NR1D1(REV-ERBa), DBP, BHLHE40 (DEC1), and BHLHE41(DEC2). The phasing of known circadian genes was consistent with data derived from other diurnal mammals. Cyclic patterns were much weaker in the brains of patients with MDD due to shifted peak timing and potentially disrupted phase relationships between individual circadian genes. This transcriptome-wide analysis of the human brain demonstrates a rhythmic rise and fall of gene expression in regions outside of the suprachiasmatic nucleus in control subjects. The description of its breakdown in MDD suggests potentially important molecular targets for treatment of mood disorders.

What Else Does Your Biometric Data Reveal? A Survey on Soft Biometrics

Abstract: Recent research has explored the possibility of extracting ancillary information from primary biometric traits viz., face, fingerprints, hand geometry, and iris. This ancillary information includes personal attributes, such as gender, age, ethnicity, hair color, height, weight, and so on. Such attributes are known as soft biometrics and have applications in surveillance and indexing biometric databases. These attributes can be used in a fusion framework to improve the matching accuracy of a primary biometric system (e.g., fusing face with gender information), or can be used to generate qualitative descriptions of an individual (e.g., young Asian female with dark eyes and brown hair). The latter is particularly useful in bridging the semantic gap between human and machine descriptions of the biometric data. In this paper, we provide an overview of soft biometrics and discuss some of the techniques that have been proposed to extract them from the image and the video data. We also introduce a taxonomy for organizing and classifying soft biometric attributes, and enumerate the strengths and limitations of these attributes in the context of an operational biometric system. Finally, we discuss open research problems in this field. This survey is intended for researchers and practitioners in the field of biometrics.