A multimodal pathway including the basal ganglia in the feline brain.

The purpose of this paper is to give an overview of our present knowledge about the feline tecto-thalamo-basal ganglia cortical sensory pathway. We reviewed morphological and electrophysiological studies of the cortical areas, located in ventral bank of the anterior ectosylvian sulcus as well as the region of the insular cortex, the suprageniculate nucleus of the thalamus, caudate nucleus, and the substantia nigra. Microelectrode studies revealed common receptive field properties in all these structures. The receptive fields were extremely large and multisensory, with pronounced sensitivity to motion of visual stimuli. They often demonstrated directional and velocity selectivity. Preference for small visual stimuli was also a frequent finding. However, orientation sensitivity was absent. It became obvious that the structures of the investigated sensory loop exhibit a unique kind of information processing, not found anywhere else in the feline visual system.

Extrafoveally applied flashing light affects contrast thresholds of achromatic and S-cone isolating, but not L-M cone modulated stimuli.

Flashing light stimulation is often used to investigate the visual system. However, the magnitude of the effect of this stimulus on the various subcortical pathways is not well investigated. The signals of conscious vision are conveyed by the magnocellular, parvocellular and koniocellular pathways. Parvocellular and koniocellular pathways (or more precisely, the L-M opponent and S-cone isolating channels) can be accessed by isoluminant red-green (L-M) and S-cone isolating stimuli, respectively. The main goal of the present study was to explore how costimulation with strong white extrafoveal light flashes alters the perception of stimuli specific to these pathways. Eleven healthy volunteers with negative neurological and ophthalmological history were enrolled for the study. Isoluminance of L-M and S-cone isolating sine-wave gratings was set individually, using the minimum motion procedure. The contrast thresholds for these stimuli as well as for achromatic gratings were determined by an adaptive staircase procedure where subjects had to indicate the orientation (horizontal, oblique or vertical) of the gratings. Thresholds were then determined again while a strong white peripheral light flash was presented 50 ms before each trial. Peripheral light flashes significantly (p < 0.05) increased the contrast thresholds of the achromatic and S-cone isolating stimuli. The threshold elevation was especially marked in case of the achromatic stimuli. However, the contrast threshold for the L-M stimuli was not significantly influenced by the light flashes. We conclude that extrafoveally applied light flashes influence predominantly the perception of achromatic stimuli.

VEP and PERG in patients with multiple sclerosis, with and without a history of optic neuritis.

PURPOSE: Visual electrophysiology is routinely used to detect the visual complications of multiple sclerosis, but the analysis mostly focuses on visual evoked potential (VEP) and especially the P100 component. Our goal was to analyze the components and waveform alterations of VEPs and pattern electroretinograms (PERGs) in patients with multiple sclerosis (MS) with good vision. METHODS: The main VEP and PERG components of 85 patients with MS were analyzed in two groups: 38 patients who had optic neuritis in their history (ON group) and 47 patients who had never had optic neuritis (MS group). The results were compared against a control group of 47 healthy subjects. RESULTS: Both VEP and PERG alterations occurred in a greater number of patients than expected, and these alterations were not necessarily linked to ON in the history or a deterioration of visual acuity. CONCLUSIONS: Both VEP and PERG can detect dysfunction in the visual system in MS, even if the patient has no subjective symptoms. Even if PERG is not routinely used in neuro-ophthalmology, the results suggest that PERG assessment may provide useful information describing the retinal defect in MS.

Smoking and Psoriasis as Synergistic Risk Factors in Periodontal disease.

In the literature both smoking and psoriasis are discussed as predisposing factors for chronic periodontal disease. It is also known that smoking leads to deterioration in both psoriasis and periodontal disease. However, up to now, the only study to address the question what effect the co-occurrence of psoriasis and smoking has on the periodontal status of the individual, was a previous study of ours. In the present study, we repeated our measurements in an extended sample. 82 psoriatic patients and 117 controls participated, who all received a full-mouth examination so that their periodontal status could be determined. The analysis was aimed at finding out about to what extent the individual risk factors (i.e. smoking and psoriasis) increased the chance of the occurrence of the advanced stages of periodontal disease. The odds ratio for smoking was 1,32 (p = 0,465), and 1,85 for psoriasis (p = 0,163). In those patients who smoked, the odds ratio was 6,22 (p < 0,001), which is three times higher than the simple combination of odds. This suggests that the risk factors are in a synergistic relationship.

A retrospective screening and epidemiological study of oncological and other diseases in the oral and maxillofacial region at the University of Szeged, Department of Oral Medicine (1960-2014).

The Department of Oral Medicine at the University of Szeged was responsible for the stomato-oncological care of the population of three counties (with a population of 1,7 M at an average) in the period 1960-201 4. The present report summarizes the incidence of oral medicine diseases during this period. The overall number of new out-patients at the Department of Oral Surgery between 1960 and 2014 was 338,200. These patients were dental and oral surgical patients who presented spontaneously or were referred from the general practice, or stomato-oncological patients referred from general dental practices in-the three counties. Of the 338,200 new cases, 9,482 (2.8%) were benign tumors, 5438 (1.6%) premalignancies and 5,145 (1.5%) malignant tumors. This means a total of 20,065 tumor cases (5.9%) in the examined period, of which 10,579 (3.1 %) were premalignancies and malignancies. 14,446 patients presented with other diseases of the oral mucous membrane (5.8%, data available from 1974). Data on the number of stomato-oncological control patients in any given year are available from 1970 on. In the period 1970-2014, the total number of check-up patients was 117,268, this is the 76,97% of the departments overall number of patients. As for the tendencies, in the representative period of 1960-2004, the number of new benign tumors 15-fold, premalignancies 30-fold, and malignant tumors exhibited an 25-fold increase, while the number of other conditions affecting the oral mucosa showed a 14-fold increase.

Caries and ABO secretor status in a Hungarian population of children and adolescents: an exploratory study.

ABO blood group antigen (ABGA) secretion into the saliva and other body fluids is a well-known phenomenon, and there is evidence to suggest a link between secretor status and the appearance of caries. It has been proposed that secretion of these antigens into the saliva might be caries-preventive, however, this proposition is still a matter of debate. Our aim was to examine the relationship between caries experience and secretor status in a group of Hungarian children and adolescents in a cross-sectional study. Altogether 130 children and adolescents participated in the study (aged 6-18 years). Participants were divided into two groups according to dentition (i.e. mixed and permanent). ABGA were determined from saliva. The DMF-T and dmf-t (decayed, missing, and filled) indices were calculated, as well as the oral health hygiene index-simplified plaque index. Association of these indices with secretor status was examined. In mixed dentition, the mean dmf-t values were significantly lower in the secretor group (2.1 ± 0.52 SEM), as compared to the nonsecretor group (3.8 ± 0.93 SEM; p < 0.05, Mann-Whitney U test). The finding that children of mixed dentition are apparently better protected against caries suggests that the assumed protective effect might be associated with deciduous teeth, but given the general paucity of knowledge about this topic, further research is indicated.

Co-oscillation and synchronization between the posterior thalamus and the caudate nucleus during visual stimulation.

Recent results suggest significant cross-correlation between the spike trains of the suprageniculate nucleus (SG) of the posterior thalamus and the caudate nucleus (CN) during visual stimulation. In the present study visually evoked local field potentials (LFPs) were recorded simultaneously in the CN and the SG in order to investigate the coupling between these structures at a population level. The effect of static and dynamic visual stimulation was analyzed in 55 SG-CN LFP pairs in the frequency range 5-57Hz. Statistical analysis revealed significant correlation of the relative powers of each investigated frequency band (5-8Hz, 8-12Hz, 12-35Hz and 35-57Hz) during both static and dynamic visual stimulation. The temporal evolution of cross-correlation showed that in the majority of the cases the SG was activated first, and in approximately one third of the cases, the CN was activated earlier. These observations suggest a bidirectional information flow. The most interesting finding of this study is that different frequency bands exhibited significant cross-correlation in a stimulation paradigm-dependent manner. That is, static stimulation usually increased the cross-correlation of the higher frequency components (12-57Hz) of the LFP, while dynamic stimulation induced changes in the lowest frequency band (5-8Hz). This suggests a parallel processing of dynamic and static visual information in the SG and the CN. To our knowledge we are the first to provide evidence on the co-oscillation and synchronization of the CN and the SG at a population level upon visual stimulation, which suggests a significant cooperation between these structures in visual information processing.

A video feedback-based tobacco cessation counselling course for undergraduates-preliminary results.

BACKGROUND: Hungary has one of the highest rates of tobacco use and decayed, missing and filled teeth in Europe, and the number of lung cancer-related deaths per annum is amongst the highest globally. As it is estimated that the rate of smokers who see their dentist or physician annually is about 70%, to involve all healthcare providers in tobacco intervention seems to be a promising strategy to reduce tobacco use in countries like Hungary. Such an intervention should obviously include the dental health team. It has already been suggested by experts on this topic that instruction in tobacco use prevention and cessation counselling for dental professionals and students of dentistry should be included in under- and postgraduate curricula. OBJECTIVES: To present a novel, video feedback-based undergraduate cessation counselling programme, which has recently been introduced to the dental curriculum at the Faculty of Dentistry, Szeged, Hungary. METHODS: Applying a problem-based learning approach, the programme consists of three main activities: a small-group interactive training session led by a faculty member, where students learn about the basic science and clinical aspects of tobacco use, including counselling skills; student interactions with professional actors (i.e. standardised patients) simulating real-life dental situations, which are recorded for post hoc evaluation; and finally an evaluation of the recorded performance of each student, with the participation of the actor, the student and a faculty member. RESULTS: With the help of this new approach, students had the chance to learn about and develop a deeper understanding of tobacco-related professional dental communication in realistic, case-based dental scenarios. Students have reported increased confidence in tobacco counselling after having participated in this programme. Furthermore, this method appears to be an ideal tool for the evaluation of both verbal and non-verbal tobacco counselling skills. CONCLUSION: To our knowledge, we are the first to have applied video feedback combined with behavioural modification methods in the teaching of tobacco cessation counselling. We conclude that teaching method can help dentists better understand smokers, gain confidence in tobacco cessation counselling and become more effective promoters of a smoke-free lifestyle. In addition, this method can be easily adapted to other healthcare educational settings, including other oral health training programmes.

Haemodynamic parameters and cognitive function during modeled acute volume loss.

PURPOSE: The purpose of the present study was to find a noninvasive way of detecting even smaller volume loss which is easier to carry out and possibly more precise than the currently used (mostly sphygmomanometer-based) methods. Haemodynamic and EEG measurements were carried out in simulated volume loss, involving blood donation and orthostatic challenges to assess adaptive responses and cognitive performance. Cognitive performance was assessed in an oddball task and changes of the evoked potential P300 were analyzed. Both haemodynamic and cognitive parameters were recorded in 'pre-donation' and 'post-donation' conditions for purposes of comparison. RESULTS: Cognitive performance (as reflected by P300 changes) was found to be a poor marker of volume loss. Difference between the two conditions in none of the parameters reached the level of statistical significance (defined as p < 0.05) RR mean, baroreceptor sensitivity and pulse pressure were rather sensitive to the relatively mild volume loss (p < 0.01 between pre- and post-conditions). CONCLUSION: Our study indicates that traditional sphygmomanometer based values can safely be replaced by values yielded by finger plethysmography, combined with brief orthostatic challenges and that P300 as a cognitive marker cannot be used to assess volume loss.

Neuronal code of spatial visual information in the caudate nucleus.

Earlier reports described huge overlapping visual receptive fields and the absence of retinotopic organization in the dorsolateral, caudal part of the caudate nucleus. In the present study we suggest a possible alternative mechanism for the coding of spatial visual information. Extracellular microelectrode recordings were carried out in halothane-anesthetized, immobilized, artificially ventilated cats. In order to investigate the responsiveness of the single neurons to visual information arriving from different sites of the receptive field, we divided the visual fields to 20 parts of equal size and stimulated the individual parts one-by-one. We found that each single visual caudate nucleus (CN) neuron can carry information about stimulus locations throughout the whole physically approachable visual field of the investigated eye. A large majority (85%) of these neurons exhibited significantly different responses to stimuli appearing in different regions of their huge receptive field. Thus these neurons appear to have the ability to provide information on the site of the stimulus via their discharge rate. The huge receptive fields in combination with the spatial selectivity suggest that these caudate nucleus neurons may serve as panoramic localizers. On the population level, the sites of maximal responsiveness of the visual neurons are distributed over the whole extent of the receptive fields. We argue that groups of these panoramic localizer neurons with different locations of maximal stimulus preference should have the ability to accurately code the locations of visual stimuli. We propose this distributed population code of visual information as an alternative information processing mechanism.

The primary structure of the hemoglobin from the lobe-lipped bat (Chalinolobus morio, Microchiroptera).

The hemoglobin of the lobe-lipped bat (Chalinolobus morio, Vespertilionidae) is composed of 45% HbI and 55% HbII. Both components show identical alpha-chains but differ at the following three positions of their beta-chains: beta I/beta II 21: Glu/Asp, 70: Ser/Ala, and 135: Gln/Leu. High performance liquid chromatography revealed pure alpha-chains and a mixture of only partly separated beta-chains. Based on this material, the primary structures of all three globin chains could be achieved by automatic Edman degradation of the whole chains and peptides obtained by trypsin hydrolysis. Compared to human hemoglobin, Chalinolobus shows 17 replacements in the alpha-chains and 24/22 in the beta-chains. A sequence comparison of the globin chains from the three vespertilionid bats Chalinolobus morio and Myotis velifer (Vespertilioninae) as well as Antrozous pallidus (Nyctophilinae) supports a close relationship of the former only for the beta-chains. Molecular modeling showed that the replacements involved in three alpha 1/beta 1 and one alpha 1/beta 2 subunit interface contacts do not cause any interruption. All phosphate binding sites and amino acid residues responsible for the Bohr effect are unchanged. Thus normal physiological properties should be expected for Chalinolobus morio hemoglobin.

The primary structure of the hemoglobin from the tomb bat (Taphozous georgianus, Microchiroptera).

The primary structures of the alpha- and beta-chains of the single hemoglobin component from the tomb bat (Taphozous georgianus, Microchiroptera) are presented. After chain separation by reversed-phase HPLC the sequences could be determined by automatic gas and liquid phase Edman degradation of the chains and their tryptic peptides. The alpha- and beta-chains differ from human hemoglobin by 14 and 18 replacements, respectively. Compared to the total number of amino-acid exchanges, the exchange rate in the interhelical regions of the alpha-chains is surprisingly high (25%). It seems unlikely that substitutions at contact positions affect the oxygen binding properties of the hemoglobin.

Carnivora: the primary structure of the major hemoglobin component from adult European lynx (Lynx lynx, Felidae).

The complete primary structure of the major hemoglobin component from the adult European lynx (Lynx lynx) is presented. Presence of two hemoglobin components and three chains, beta A, beta B, and alpha, identified by gel electrophoresis. The purification of the globin chains achieved by ion-exchange chromatography. The globin chains were digested with trypsin. The peptide generated were purified by reversed-phase HPLC. Sequencing of the native chains up to 42 cycles and of the tryptic peptides were deduced by Edman degradation in liquid- and gas-phase sequencer. The primary structure established aligned with those of human Hb-A. The comparison of lynx globin chains with other representatives of the Felidae, lion, tiger, jaguar, leopard, and cat revealed high homology.

The primary structure of the hemoglobin from the Australian ghost bat (Macroderma gigas, Microchiroptera).

The Australian ghost bat (Macroderma gigas, Microchiroptera) has two hemoglobin components in the ratio 3:2. They share identical beta-chains and differ by three replacements in the alpha-chains. The primary structures of all three chains are presented. They could be separated by high-performance liquid chromatography. The sequences were determined by automatic liquid and gas phase Edman degradation of the chains and their tryptic peptides. The two alpha-chains show 18 and 19 and the beta-chains 15 exchanges compared to human alpha- and beta-chains, respectively. The divergent evolution of Macroderma gigas and Megaderma lyra, two representatives of the family Megadermatidae, is discussed. An influence of replacements at functionally important positions on the hemoglobin oxygen affinity seems unlikely.

Primary structure and oxygen-binding properties of the hemoglobin from the lesser hedgehog tenrec (Echinops telfairi, Zalambdodonta). Evidence for phylogenetic isolation.

The primary structures of the alpha- and beta-hemoglobin chains of the lesser hedgehog tenrec (Echinops telfairi, Zalambdodonta) are presented. Chain separation was performed by carboxymethyl-cellulose chromatography. The peptides, obtained by tryptic digestion of the oxidized chains, were prefractionated by gel chromatography and isolated by reversed-phase HPLC. For sequence analysis gas and liquid phase sequencers were employed. The tenrec hemoglobin consists of one alpha- and two beta-chains the latter occurring in a 1:1 ratio and differing in beta 16 Gly/Cys and beta 118 Phe/Leu. Two external cysteine residues at beta 16 and beta 52 cause reversible polymerization to octamers and most likely irreversible formation of higher polymers. A comparison of the whole chains and certain positions of tenrec hemoglobin with those of Insectivora sensu strictu, Scandentia and Proto- and Metatheria corroborates a long and independent evolution of tenrec and its phylogenetic isolation from the Insectivora s.str. (hedgehog, musk shrew and mole). Replacements at positions involved in heme and subunit interface contacts are discussed. Compared to human hemoglobin the tenrec pigment shows a low intrinsic oxygen affinity as well as lower chloride and temperature sensitivities, a reduced Bohr effect and a strong response to 2,3-DPG. The possible adaptive significance of these properties is discussed in relation to the large diurnal body temperature variations seen in tenrecs.

Adaptation of bird hemoglobins to high altitudes: demonstration of molecular mechanism by protein engineering.

Of two closely related species of geese, one, the greylag goose, lives in the Indian plains all year round, while the other, the bar-headed goose, lives at the Tibetan lakes and migrates across the Himalayas to winter in India. Another species, the Andean goose, lives in the High Andes all year round. Possession of a Hb with high oxygen affinity helps to adapt bar-headed and Andean geese to high altitudes. The Hb amino acid sequences of the bar-headed and the greylag geese differ by four substitutions, of which only one is unique among bird sequences: Pro-119 alpha (H2)----Ala. Perutz proposed that the two-carbon gap left by this substitution at the alpha 1 beta 1 contact raises the oxygen affinity, because it relaxes the tension in the deoxy or T structure [Perutz, M. F. (1983) Mol. Biol. Evol. 1, 1-28]. It was later found that the Hb of the Andean goose has a gap in the same position, due to the complementary substitution Leu-55 beta (D6)----Ser. We have tested Perutz's hypothesis by introducing each of these substitutions into human globin synthesized in Escherichia coli. The reconstituted Hbs combine cooperatively with oxygen. Their oxygen affinities exceed that of normal human Hb by an even larger factor than that found between the high-flying geese and the greylag goose. The mutant Hb Met-55 beta (D6)----Ser was crystallized. Its structure is the same as that of HbA, except in the immediate environment of the gap left by the substitution of the serine for the methionine side chain, which evidently causes the increased oxygen affinity of this Hb.

Primary structure of hemoglobin from monitor lizard (Varanus exanthematicus albigularis--Squamata).

The primary structure of the major hemoglobin component from the Monitor Lizard Varanus exanthematicus albigularis is presented. The polypeptide subunits were separated by reversed-phase high-performance liquid chromatography on Nucleosil C-4 column. The amino-acid sequence was established by automatic Edman degradation of the native polypeptide and its tryptic and hydrolytic cleavage products in a spinning cup sequencer. The structural data are discussed with reference to other reptiles.

The complete primary structure of the marine Carnivora, galapagoes fur seal (Arctocephalus galapagoensis, Otariidae) hemoglobins.

The complete primary structure of the two hemoglobin components of the fur seal (Arctocephalus galapagoensis) is presented. The two components (HbI and HbII) occur in nearly equal amounts and have identical beta-chains; whereas the two alpha-chains (alpha I/alpha II) differ by six exchanges Ile/Val, Met/Thr, Ser/Ala, Pro/His, Lys/Gly, and Thr/Ala at positions 10, 34, 35, 50, 78, and 131, respectively. The components were isolated by DEAE-Sephacel chromatography and were separated into the globin chains by RP-HPLC on a column of Nucleocil-C4. The sequences have been determined by Edman degradation in liquid- and gas-phase sequencer, using the native chains and tryptic peptides. The sequences compared with those of other Carnivora species and an adult human globin chains. An identical beta-chain is found in fur seal and walrus, whereas larger differences were found between alpha I and alpha II compared to beta-chains.

The primary structure of the hemoglobin from the aardwolf (Proteles cristatus, Hyaenidae).

The hemoglobin of the aardwolf (Proteles cristatus) contains only one component. In this paper, we are presenting its primary structure. The globin chains were separated by high-performance liquid chromatography and the sequences determined by automatic liquid and gas-phase Edman degradation of the chains and their tryptic peptides. The alpha- as well as the beta-chains show 20 exchanges compared with the corresponding human chains. The difference to the masked palm civet (Paguma larvata) and the spotted hyaena (Crocuta crocuta) is marked by 16 and 4 replacements in the alpha-chains and by 10 and 1 in the beta-chains, thus supporting the hyaenid character of the aardwolf. The exchanges at contact positions are shared by other carnivoran hemoglobins.