Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Cogn Emot ; 31(4): 699-711, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27053147

RESUMO

The way our brain processes emotional stimuli has been studied intensively. One of the main issues still under debate is the laterality of valence processing. Herein, we employed the fact that pupil size increases under conditions of higher mental effort and during emotional processing, in order to contrast three proposed hypotheses in the field. We used different manual response mapping for emotional stimuli: Participants responded with their right hand for positive and with their left hand for negative facial expressions, or vice versa. The hands position was either regular (Experiment 1) or crossed (Experiment 2) in order to rule out a "spatial-valence association" alternate explanation. A third experiment was conducted by employing a passive viewing procedure of peripheral emotional stimuli. In the first two experiments, pupil size was larger when participants responded to positive stimuli with their left hand and to negative with their right hand, compared with the opposite mapping. Results of Experiment 3 strengthen the findings of Experiments 1 and 2. These findings provide significant psychophysiological evidence for the valence hypothesis: Processing positive stimuli involves the left hemisphere, while processing negative stimuli involves the right hemisphere. These results are discussed in relation to contemporary theories of emotion processing.


Assuntos
Pupila/fisiologia , Dilatação , Emoções/fisiologia , Expressão Facial , Lateralidade Funcional/fisiologia , Mãos , Humanos , Estimulação Luminosa
2.
Psychon Bull Rev ; 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38351255

RESUMO

Mechanisms of object-based attention (OBA) are commonly associated with the cerebral cortex. However, less is known about the involvement of subcortical visual pathways in these processes. Knowledge of the neural mechanisms subserving OBA can provide insight into the evolutionary trajectory of attentional selection. In the current study, the classic double-rectangle cueing task was implemented using a stereoscope in order to differentiate between the involvement of lower (monocular) and higher (binocular) visual pathways in OBA processes. We found that monocular visual pathways are involved in two main aspects of OBA: exogenous orienting towards a cued object (Experiment 1; N =33) and attentional deployment within a cued object (Experiment 2; N =23); this is evident by the presence of OBA only when both the cue and target were presented to the same eye. Thus, these results indicate that monocular (mostly subcortical) visual regions are not simply passing information to higher cortical areas but have a functional computational role in OBA. These findings emphasize the importance of lower regions in attentional processes and, more specifically, in OBA.

3.
Br J Oral Maxillofac Surg ; 59(2): 197-201, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33349493

RESUMO

We describe a novel technique for the insertion of a vacuum drain, in an outpatient setting, for persistent seroma post-parotidectomy. This is a retrospective case series of a single academic centre. The complete medical records of all patients who underwent parotidectomy between 2014 and 2019 were reviewed. Data regarding demographics, comorbidities, and intraoperative and postoperative courses were extracted for patients for whom a vacuum drain was inserted due to persistent seroma. A size 8 Fr drain was inserted using a novel approach through the parotidectomy incision using 'Biovac' (Biometrix) 50ml, Trocar kit, that had been adjusted and modified for this purpose. Two hundred and eighteen patients had had parotidectomy during the study period. Eight patients (3.6%) underwent insertion of the drain due to persistent seroma. In three patients (37.5%) no drain was inserted during the initial surgery. The mean (SD) time between surgery and insertion of the outpatient vacuum drain was 10 (5) days. All drain insertions were uneventful and no complications were noted. The mean (SD) time for outpatient vacuum drain removal was 12.75 (4.3) days. A single patient (12.5%) underwent additional needle aspiration of 5cc few days following removal of the drain. Persistent seromas may be managed in an outpatient clinic with good results and a high safety profile.


Assuntos
Pacientes Ambulatoriais , Seroma , Drenagem , Feminino , Humanos , Complicações Pós-Operatórias , Gravidez , Estudos Retrospectivos , Seroma/etiologia , Vácuo
4.
Cognition ; 195: 104108, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31805469

RESUMO

Cognitive processes are traditionally studied in individual settings, while the possible effect of the social context is ignored. The present study focuses on the social inhibition of return effect (SIOR; Welsh et al., 2005). According to it, observation of another person's action at a specific location initiates an inhibitory process in the observer at that location. The aim of the present study was to investigate which processes are influenced by the social context (e.g. action representation, attention, etc.) and whether this effect is elicited only in a social context. In a series of four experiments we examined the SIOR effect by developing a dyadic computerized task in which each participant, in turn, responded to a peripherally presented target in two successive trials. The first trial was performed after the other participant had responded and was designed to examine SIOR. The second trial was aimed at studying self-induced IOR. The first two experiments replicated and extended previous findings by demonstrating that information regarding the counterpart's response location was sufficient to produce SIOR. In the third experiment the participants performed the same task but without a counterpart so that SIOR was eliminated. The fourth experiment demonstrated that believing there is a co-actor is enough to elicit the SIOR effect. These findings suggest that knowing that a location was acted upon before by another person (by observation or by prior knowledge) is the minimal condition for the SIOR effect to be evoked.


Assuntos
Inibição Psicológica , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Interação Social , Percepção Espacial/fisiologia , Adulto , Feminino , Humanos , Tempo de Reação/fisiologia , Adulto Jovem
5.
Psychoneuroendocrinology ; 102: 9-15, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30481725

RESUMO

Socially anxious individuals show increased sensitivity toward social threat signals, including cues of dominance. This sensitivity may account for the hypervigilance and gaze avoidance commonly reported in individuals with social anxiety. This study examines visual scanning behavior in response to androstadienone (androsta-4,16,-dien-3-one), a putative chemosignal of dominance. We tested whether exposure to androstadienone would increase hypervigilance and gaze avoidance among individuals with high social anxiety. In a double-blind, placebo-controlled, within-subject design, 26 participants with high social anxiety and 26 with low social anxiety were exposed to androstadienone and a control solution on two separate days. On each day, an eye-tracker recorded their spontaneous scanning behavior while they viewed facial images of men depicting dominant and neutral poses. The results indicate that among participants with high social anxiety, androstadienone increased gaze avoidance by reducing the percentage of fixations made to the eye-region and the total amount of time spent gazing at the eye-region of the faces. Participants with low social anxiety did not show this effect. These findings indicate that androstadienone serves as a threatening chemosignal of dominance, further supporting the link between hypersensitivity toward social threat cues and the perpetuation of social anxiety.


Assuntos
Androstadienos/metabolismo , Androstadienos/farmacologia , Ansiedade/metabolismo , Adulto , Ira , Ansiedade/fisiopatologia , Sinais (Psicologia) , Método Duplo-Cego , Movimentos Oculares , Expressão Facial , Medo , Fixação Ocular/efeitos dos fármacos , Humanos , Masculino , Odorantes , Feromônios Humano/metabolismo , Predomínio Social , Percepção Social
6.
Genetics ; 75(3): 485-95, 1973 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-4204549

RESUMO

Recombination at the Bar locus in Drosophila melanogaster was investigated in an inverted attached-X system which enhanced the frequency of homozygosis for the Bar region. Females among the progeny of homozygous B mothers were searched for changes of B to BB and to B(+). Marker genes were followed and exceptional half-tetrads were analyzed in regard to two hypotheses: that of exchange between obliquely synapsed members of the duplication, which is associated with exchange of outside markers, and that of intrachromosomal exchange, which does not involve recombination of markers.-Recombinant exceptions of B(+) /BB genotype, carrying the outside marker combinations predicted on the hypothesis of exchange between obliquely synapsed duplication members, were encountered repeatedly. It is established that B(+) and BB strands are reciprocal products of the same event.-Twelve nonrecombinant exceptional strands were isolated; ten of these were B(+) and two were BB. Only one of the nonrecombinant half-tetrads offered the opportunity to test the prediction of reciprocity of the intrachromosomal event. Analysis showed the exceptional female to be of the constitution BB/B, a type not expected on the hypothesis. While it could have arisen through some kind of copy error in the repair of a chromatid break, a valid test of the hypothesis of intrachromosomal exchange must rest on the isolation and analysis of more cases of the appropriate exceptional genotype.-In several cases Bar changes were found to be associated with aberrations; all but one of these involved spontaneous, cytologically identifiable deletions.


Assuntos
Recombinação Genética , Cromossomos Sexuais , Animais , Aberrações Cromossômicas , Troca Genética , Drosophila melanogaster , Olho , Feminino , Genótipo , Masculino
7.
Invest Ophthalmol Vis Sci ; 29(4): 528-33, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3356511

RESUMO

The copper vapor laser is a pulsed gas laser which emits energy in two wavelengths simultaneously: 510.6 nm (green) and 578.2 nm (yellow). Each pulse has a duration of 15 nsec, maximal energy of 3 mJ and a peak power of more than 100 kW. It is a variably high repetition rate laser, in the range between 1 kHz and more than 20 kHz. We studied its interaction with the rabbit retina, while using two different repetition rates, 4 kHz and 18 kHz. The histological analysis of the lesion produced by 4 kHz repetition rate showed undesired retinal effects, similar to those caused by other pulsed lasers. On the other hand, the histological examination of the lesion produced by the 18 kHz repetition rate showed a desired coagulation effect, limited to the outer retinal layers, and comparable to a lesion produced by a continuous wave (CW) laser.


Assuntos
Lasers , Retina/efeitos da radiação , Animais , Cobre , Terapia a Laser , Fotocoagulação , Oftalmologia/instrumentação , Células Fotorreceptoras/patologia , Células Fotorreceptoras/efeitos da radiação , Células Fotorreceptoras/ultraestrutura , Epitélio Pigmentado Ocular/patologia , Epitélio Pigmentado Ocular/ultraestrutura , Retina/patologia
8.
Am J Ophthalmol ; 107(1): 47-51, 1989 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-2643332

RESUMO

We used the 193-nm argon-fluoride excimer laser to cut plano corneal lenticules from fresh corneal tissue for lamellar keratoplasty. The laser was used to cut away all corneal tissue outside a specially designed mold, which was developed to obtain a corneal lenticule of 10 mm in diameter and a constant thickness of 0.3 mm. The surface topography of the excimer laser-cut corneal lenticule was smoother and more regular on scanning electron microscopy than a hand-cut corneal lenticule, and the thickness was constant around the surface. No thermal or mechanical damage to the cornea was observed on light microscopy in the area adjacent to the cut.


Assuntos
Transplante de Córnea , Terapia a Laser , Córnea/ultraestrutura , Humanos , Terapia a Laser/instrumentação
9.
Anticancer Res ; 17(5A): 3409-23, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9413180

RESUMO

The antitumor effects of "half-mustard type" phenothiazines were studied on 57 different tumor cell lines, including leukemias, non-small lung cancer, colon, central nervous system, ovarian, renal, breast, and prostate cancer, as well as melanoma cell cultures. Alkyl-urea derivatives of phenothiazines displayed in vitro antitumor activity. The phenothiazine phthalimido derivatives (1-6) were not active on the majority of cancer cell cultures. In contrast, propylureas (9, 11) were active against some leukemia cell types. Only two compounds with the butylene [(CH2)4] linker (10, 12) were active against non-small lung cancer cells. Compounds containing the propylene linker were less effective. On colon cancer lines, tumor cells from the central nervous system and on melanoma cells the same compounds were effective, however, having substituents at the 2-position of phenothiazine seems to be important. Surprisingly, the majority of ovarian cancer cell lines (except one type, IGROVI) and five of eight renal cancer lines were not sensitive to these phenothiazine derivatives. The two butylene linked phenothiazine ureas (10, 12) had moderate antiproliferative action on two renal cancer cell lines. The prostate cancer and some breast cancer cell lines were not sensitive. Nevertheless some breast cancer cell lines were apparently sensitive to CF3-substituted phenothiazine alkylureas. On the basis of these experiments one may postulate that in the case of insensitive cells an mdr-gene encoded multidrug resistance efflux pump is responsible for the resistance. The selectivity or organ cell specificity of the effective phenothiazines will be targeted for improvement in further studies, in order to avoid the general cytotoxic effects of "half mustard type" phenothiazines.


Assuntos
Antineoplásicos , Fenotiazinas/farmacologia , Ftalimidas/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Ureia/análogos & derivados , Divisão Celular/efeitos dos fármacos , Feminino , Humanos , Neoplasias Renais/tratamento farmacológico , Leucemia/tratamento farmacológico , Masculino , Compostos de Mostarda Nitrogenada/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias da Próstata/tratamento farmacológico , Relação Estrutura-Atividade , Ureia/farmacologia
10.
Anticancer Res ; 17(5A): 3425-9, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9413181

RESUMO

Twelve different "half-mustard type" phenothiazines were newly synthesized and tested on seven AIDS-related lymphoma (ARL) tumor cell lines, one leukemia CCRF-CEM cell culture and five different lymphoma lines; RL, KD-488, AS283, PA682 and SU-DHL-7 cell lines. The alkylene-urea substituted phenothiazines affected the growth and inhibited the growth rate of AIDS-related lymphoma cells. The Cl-substituent at the 2-position was more effective than the CF3 substitution. In AIDS-related leukemia also the compounds with Cl at the 2-position with propylene or butylene linkers, -(CH2)3- and -(CH2)4-, respectively, were more effective than the CF3 substituted compounds. Two of the six phenothiazine-substituted alkyl-urea derivatives, i.e., 1-(2-chloroethyl)-3-(2-chloro-10H-phenothiazin-10-yl)propyl-l-urea (9, GI50 = -5.66, TGI = -5.04) and 1-(2-chloroethyl)- 3-(2-chloro-10H-phenothiazin-10-yl)butyl-1-urea (10, GI50 = -5.61, TGI = -5.12) exhibited antitumor activity for AIDS-related leukemia and five AIDS-related lymphomas. The trifluoromethyl-substituted derivatives were not as effective on AIDS-related tumor cell lines. Apparently, the substituent at the 2-position on the phenothiazine and the alkylene number of the linker attached to the nitrogen of the phenothiazine ring have an important role in the compound's antitumor effects on AIDS-related leukemia and lymphomas.


Assuntos
Antineoplásicos , Linfoma Relacionado a AIDS/tratamento farmacológico , Fenotiazinas/farmacologia , Ftalimidas/farmacologia , Ureia/análogos & derivados , Humanos , Leucemia/tratamento farmacológico , Linfoma/tratamento farmacológico , Compostos de Mostarda Nitrogenada/farmacologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Ureia/farmacologia
11.
Anticancer Res ; 18(1A): 337-48, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9568100

RESUMO

Some new phenothiazines have been synthesized on the basis of previous studies. The anticancer activity of "half-mustard type" phenothiazines was investigated on sixty different cancer cell lines in vitro. The percentage of growth (PG), 50% inhibition of growth (GI50), the tumor growth inhibition (TGI) and the concentration required for 50% lethality of cells (IC50) were examined and calculated in the presence of various (from 10(-4) to 10(-8) M) concentrations of phenothiazine alkylurea derivatives. The following cell lines were involved in the study: 6 leukemia, 9 non-small-cell lung cancer, 7 colon cancer, 6 central nervous system cancer, 8 melanoma, 6 ovarian cancer, 8 renal cancer, 2 prostate and 8 breast cancer cell lines. The antileukemic activity of four chloroethyl-substituted phenothiazine-alkylureas was shown by considerable growth inhibition, in the 10(-5) M range, of the six different leukemia cell lines. The 50% inhibition of growth was nearly the same for the four compounds on all cell lines. Tumor growth inhibition (TGI) and IC50 value to cells varied from -4.0 to -4.66. The two derivatives with the butylene bridge were more effective than propylene linked compounds against the CCRP-CEM, HL60 (TB), K-562 and MOLT-4 cell lines. However, the anti-leukemic activity of the derivatives was nearly the same for RPMT 8226 and SR cell lines. The substituent at the 2- position of phenothiazine ring and the length of the linker between the side chain nitrogen and the phenothiazine ring system are apparently important for antileukemic activity. Four of the 9 non-small-cell lung cancer cell lines were sensitive, while the other 5 cell lines were not. The compounds had a slight growth inhibitory effect on colon cell carcinoma and melanoma cells in which case the butylene linker seemed to be more effective than the propylene linker. At the same time, all of the compounds were weak or mostly inactive on cancer cells from the central nervous system. One ovarian cancer line of the 6, the IGROVI was sensitive to butylurea phenothiazines, however, the other five were not sensitive at all. The difference in the sensitivity of various renal cell carcinomas was significant: 5 lines were not sensitive, three of them (786-0, RXF-393 and TK-10) were sensitive to only butylene-substituted phenothiazine-ureas, propylene substitution resulted in ineffective compounds. The compounds were not able to inhibit the 2 prostate and 4 breast cancer cell lines, even at 10(-4) M. It was interesting that propylene-linked ureas were more effective than butylene-linked derivatives on MCF-7, but butylene-linked derivatives were more effective than propylene-linked compounds on MDA MB-231 and MDA-N. In addition, MDA MB 435 was more sensitive to the trifluoromethyl derivatives than the compounds without this substituent. Since the phthalimido-alkyl phenothiazines were not active at the first level of prescreen, these compounds were omitted from this study. The drug sensitivity of some cancer cell lines was not uniform for the different groups, therefore we postulate that the resistance can be related to some kind of (existing) drug-efflux mechanism. Apparently, the tumor specificity of phenothiazine alkylureas is more related to the leukemia specificity of alkylureas than to any CNS or lung specificity of phenothiazines.


Assuntos
Antineoplásicos/farmacologia , Inibidores do Crescimento/farmacologia , Fenotiazinas/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa