RESUMO
Objective: To analyse the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) with syndormic and non-syndormic short stature. Methods: The clinical data of 59 children born SGA who were diagnosed as short stature and admitted to the Center of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital from July 2012 to June 2021 were collected and analyzed. According to the 2019 consensus on short stature, they were divided into syndromic group and non-syndromic group. Before treatment and 6, 12, 18 and 24 months after treatment, height standard deviation score (Ht-SDS), difference of height standard deviation (∆Ht-SDS) and homeostasis model assessment-insulin resistance index (HOMA-IR) were compared between groups, while Ht-SDS and HOMA-IR were compared before and after treatment. Independent t test or Kruskal-Wallis test were used for comparison between the 2 groups, and paired t test or Mann-Whitney U test were used for the intra-group comparison. Results: Among the 59 cases, 37 were males and 22 females, aged (5.5±2.3) years. There was no significant difference in Ht-SDS after 12 months of treatment between 2 groups (0.9±0.4 vs. 1.2±0.4, t=1.68, P=0.104) or in height SDS after 24 months of treatment (1.4±0.7 vs. 1.9±0.5, t=1.52, P=0.151). After 12 months of treatment, the insulin resistance index of the non-syndromic group was significantly higher than that of the syndromic group (2.29 (1.43, 2.99) vs. 0.90 (0.55, 1.40), Z=-2.95, P=0.003). There were significant differences in Ht-SDS between 6 months and before treatment, 12 months and 6 months in syndromic type (Z=7.65, 2.83 P<0.001, P=0.020), but all were significant differences in non-syndromic type between 6 months and before treatment, 12 months and 6 months, 18 months and 12 months, 24 months and 18 months (Z=11.95, 7.54, 4.26, 3.83, all P<0.001). Conclusion: The efficacy of rhGH treatment in children born SGA is comparable between syndromic and non-syndromic short stature cases, but non-syndromic children treated with rhGH need more frequent follow-up due to the risk of insulin resistance.
Assuntos
Hormônio do Crescimento Humano , Resistência à Insulina , Criança , Feminino , Humanos , Masculino , Estatura , Idade Gestacional , Hormônio do Crescimento Humano/uso terapêutico , Recém-Nascido Pequeno para a Idade Gestacional , Insulina , Proteínas Recombinantes , Pré-EscolarRESUMO
Objective: To evaluate the effect of reducing-opioids on postoperative delirium (POD) incidence in elderly patients with gastric cancer surgery. Methods: From July 2016 to September 2021, 130 elderly patients undergoing scheduled gastric cancer surgery in Zhejiang Cancer Hospital were selected and divided into conventional opioid general anesthesia group (group A) and reducing-opioids general anesthesia group (group B) according to random number table. Postoperative analgesic pump formula: group A: 0.2% ropivacaine and 1 µg/ml sufentanil solution; Group B: 0.2% ropivacaine solution. POD assessment was performed once daily between 8 am and 8 pm for 3 days after surgery. The primary outcome measures were POD incidence 3 days after surgery, and the secondary outcome measures included anaesthesia related adverse events 3 days after surgery, such as nausea and vomiting, postoperative fever and fatigue. Results: Among the 130 patients, 7 patients were excluded because they did not comply with the POD test after operation. Finally, 123 elderly patients completed the study. There were 59 cases in group A, aged (73±5) years, including 45 males, and 64 cases in group B, aged (71±6) years, including 56 males. The incidence of total POD 3 days after surgery in group A and B was 30.5% (18/59) and 18.8% (12/64), respectively, with no statistical significance (P>0.05). However, POD incidence at 48 and 72 h after operation in group A [27.1% (16/59) and 16.9% (10/59)] was higher than that in group B [10.9% (8/64) and 4.7% (3/64), both P<0.05]. The incidence of nausea and vomiting in group A was higher than that in group B [15.3% (9/59) vs 1.6% (1/64), P<0.05]. Conclusion: Reducing-opioids consumption have no effect on the incidence of total POD 3 d after gastric cancer surgery in elderly patients, but can reduce the risk of POD 48-72 h after surgery.
Assuntos
Delírio , Neoplasias Gástricas , Idoso , Analgésicos Opioides/uso terapêutico , Delírio/tratamento farmacológico , Delírio/epidemiologia , Humanos , Incidência , Masculino , Complicações Pós-Operatórias/epidemiologia , Neoplasias Gástricas/cirurgiaRESUMO
Objective: To investigate the incidence and treatment of perioperative anemia in patients with gastrointestinal neoplasms in Hubei Province. Methods: The clinicopathological data of 7 474 patients with gastrointestinal neoplasms in 62 hospitals in 15 cities (state) of Hubei Province in 2019 were collected in the form of network database. There were 4 749 males and 2 725 females. The median age of the patients was 62 years (range: 17 to 96 years). The hemoglobin value of the first time in hospital and the first day after operation was used as the criterion of preoperative anemia and postoperative anemia. Anemia was defined as male hemoglobin <120 g/L and female hemoglobin <110.0 g/L, mild anemia as 90 to normal, moderate anemia as 60 to <90 g/L, severe anemia as <60 g/L. The t test and χ2 test were used for inter-group comparison. Results: The overall incidence of preoperative anemia was 38.60%(2 885/7 474), and the incidences of mild anemia, moderate anemia and severe anemia were 25.09%(1 875/7 474), 11.37%(850/7 474) and 2.14%(160/7 474), respectively. The overall incidence of postoperative anemia was 61.40%(4 589/7 474). The incidence of mild anemia, moderate anemia and severe anemia were 48.73%(3 642/7 474), 12.20%(912/7 474) and 0.47%(35/7 474), respectively. The proportion of preoperative anemia patients receiving treatment was 26.86% (775/2 885), and the proportion of postoperative anemia patients receiving treatment was 14.93% (685/4 589). The proportions of preoperative anemia patients in grade â ¢A, grade â ¢B, and grade â ¡A hospitals receiving treatment were 26.12% (649/2 485), 32.32% (85/263), and 29.93% (41/137), and the proportions of postoperative anemia patients receiving treatment were 14.61% (592/4 052), 22.05% (73/331), and 9.71% (20/206). The proportion of intraoperative blood transfusion (16.74% (483/2 885) vs. 3.05% (140/4 589), χ²=434.555, P<0.01) and the incidence of postoperative complications (17.78% (513/2 885) vs. 14.08% (646/4 589), χ²=18.553, P<0.01) in the preoperative anemia group were higher than those in the non-anemia group, and the postoperative hospital stay in the preoperative anemia group was longer than that in the non-anemia group ((14.1±7.3) days vs. (13.3±6.2) days, t=5.202, P<0.01). Conclusions: The incidence of perioperative anemia in patients with gastrointestinal neoplasms is high. Preoperative anemia can increase the demand for intraoperative blood transfusion and affect the short-term prognosis of patients. At present, the concept of standardized treatment of perioperative anemia among gastrointestinal surgeons in Hubei Province needs to be improved.
Assuntos
Anemia , Neoplasias Gastrointestinais , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/epidemiologia , Transfusão de Sangue , Feminino , Neoplasias Gastrointestinais/complicações , Neoplasias Gastrointestinais/cirurgia , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
Carotid femoral pulse wave velocity (cfPWV) is the 'gold standard' for assessment of arterial stiffness. The reliability of cfPWV measurement depends on the estimation of pulse transit time (PTT). This study aimed to validate a region-matching method for determining PTT and cfPWV against the existing 'foot-to-foot' methods. A cohort of 81 subjects (33 males and 48 females) aged 25-80 (45.1±15.7 years) were studied. PTTs were estimated by the region matching and 'foot-to-foot' methods ('diastole minimum', 'maximum first derivative', 'maximum second derivative' and 'tangent intersection' methods) with manual identification as the reference method and were subsequently used to calculate cfPWV. In a subgroup of 30 individuals, the measurements were repeated after 1 h. There were excellent correlations between cfPWV obtained by the reference method and all the estimated methods (r>0.9, P<0.001 for all), except the diastole minimum method (r=0.793, P<0.001). The region-matching method yielded cfPWV with a better accuracy (mean difference=-0.161 m s(-1), limits of agreement: -0.79 to 0.46 m s(-1)) and repeatability (mean difference=-0.228 m s(-1), intraclass correlation coefficient=0.957) comparing with the 'foot-to-foot' methods. These results demonstrate that the proposed region-matching method is more accurate and suitable for PTT estimation and cfPWV measurement.
Assuntos
Artérias Carótidas/fisiopatologia , Artéria Femoral/fisiopatologia , Doença Arterial Periférica/diagnóstico , Análise de Onda de Pulso/métodos , Rigidez Vascular , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Doença Arterial Periférica/fisiopatologia , Valor Preditivo dos Testes , Reprodutibilidade dos TestesRESUMO
In wastewater treatment plants (WWTPs), activated sludge is thickened in secondary settling tanks and recycled into the biological reactor to maintain enough biomass for wastewater treatment. Accurately estimating the activated sludge concentration in the lower portion of the secondary clarifiers is of great importance for evaluating and controlling the sludge recycled ratio, ensuring smooth and efficient operation of the WWTP. By dividing the overall activated sludge-thickening curve into a hindered zone and a compression zone, an empirical model describing activated sludge thickening in the compression zone was obtained by empirical regression. This empirical model was developed through experiments conducted using sludge from five WWTPs, and validated by the measured data from a sixth WWTP, which fit the model well (R² = 0.98, p < 0.001). The model requires application of only one parameter, the sludge volume index (SVI), which is readily incorporated into routine analysis. By combining this model with the conservation of mass equation, an empirical model for compression settling was also developed. Finally, the effects of denitrification and addition of a polymer were also analysed because of their effect on sludge thickening, which can be useful for WWTP operation, e.g., improving wastewater treatment or the proper use of the polymer.
Assuntos
Modelos Teóricos , Eliminação de Resíduos Líquidos , Águas Residuárias/química , Poluentes Químicos da Água/química , Biomassa , EsgotosRESUMO
To understand the clinical epidemiology and molecular characteristics of human bocavirus (HBoV) infection in children with diarrhoea in Guangzhou, South China, we collected 1128 faecal specimens from children with diarrhoea from July 2010 to December 2012. HBoV and five other major enteric viruses were examined using real-time polymerase chain reaction. Human rotavirus (HRV) was the most prevalent pathogen, detected in 250 (22·2%) cases, followed by enteric adenovirus (EADV) in 76 (6·7%) cases, human astrovirus (HAstV) in 38 (3·4%) cases, HBoV in 17 (1·5%) cases, sapovirus (SaV) in 14 (1·2%) cases, and norovirus (NoV) in 9 (0·8%) cases. Co-infections were identified in 3·7% of the study population and 23·5% of HBoV-positive specimens. Phylogenetic analysis revealed 14 HBoV strains to be clustered into species HBoV1 with only minor variations among them. Overall, the detection of HBoV appears to partially contribute to the overall detection gap for enteric infections, single HBoV infection rarely results in severe clinical outcomes, and HBoV sequencing data appears to support conserved genomes across strains identified in this study.
Assuntos
DNA Viral/análise , Diarreia/epidemiologia , Gastroenterite/epidemiologia , Bocavirus Humano/genética , Infecções por Parvoviridae/epidemiologia , RNA Viral/análise , Adenoviridae/genética , Infecções por Adenovirus Humanos/epidemiologia , Infecções por Adenovirus Humanos/virologia , Adolescente , Infecções por Astroviridae/epidemiologia , Infecções por Astroviridae/virologia , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Criança , Pré-Escolar , China/epidemiologia , Coinfecção/epidemiologia , Coinfecção/virologia , Estudos Transversais , Diarreia/virologia , Fezes/virologia , Feminino , Gastroenterite/virologia , Humanos , Lactente , Recém-Nascido , Masculino , Mamastrovirus/genética , Norovirus/genética , Infecções por Parvoviridae/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/genética , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Sapovirus/genéticaRESUMO
The aim of this study was to assess the effectiveness of early exploration of anterolateral thigh (ALT) free flap compromise in head and neck reconstruction and to correlate this with the salvage success rate. The perioperative data of 1051 patients with 1072 ALT flap reconstructions were reviewed retrospectively for the period January 2002 to December 2012. Outcome measures included ethnicity, defect type, incidence and timing of flap compromise, type of flap compromise, causes of vascular occlusion, and salvage rate. The success rate of free flap reconstruction was 97.3% (1043/1072). Of the 29 failures, 21 were complete and eight were partial failures (10-40% of the flap). Venous occlusions occurred in 39 flaps (83.0%) and arterial occlusions in five flaps (17.0%). Six cases were detected within 8h postoperatively, 13 at 8-16 h postoperatively, seven at 16-24h postoperatively, and 18 at 24-48 h postoperatively, with respective salvage rates of 66.7%, 61.5%, 28.6%, and 22.2%; three cases detected after 48 h failed. The salvage rate at ≤16 h (62.2%) was much higher than that at >16 h (21.4%, P=0.0039). Early detection, re-exploration, and effective handling of the flap crisis increases the rate of flap salvage tremendously.
Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Retalho Miocutâneo , Procedimentos de Cirurgia Plástica/métodos , Coxa da Perna , Adolescente , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Retalho Miocutâneo/irrigação sanguínea , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Fatores de Risco , Terapia de Salvação , Resultado do TratamentoRESUMO
Simultaneous procurement of the pancreas and liver necessitates division of vessels supplying both organs. The integrity of the pancreatic arterial supply appears to be related to surgical complications after pancreas transplantation. We have described herein three cases of gastroduodenal artery (GDA) reconstruction during pancreas transplantation, and reviewed other options for GDA reconstruction. These techniques performed safely during bench reconstruction can be applied to various clinical situations.
Assuntos
Duodeno/irrigação sanguínea , Duodeno/transplante , Transplante de Rim/métodos , Transplante de Fígado/métodos , Transplante de Pâncreas/métodos , Estômago/irrigação sanguínea , Procedimentos Cirúrgicos Vasculares , Adulto , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo , Resultado do TratamentoRESUMO
A biological microbeam for precisely positioned single-ion/single cell irradiation is built in the Institute of Modern Physics in Fudan University, Shanghai, China, based on the tandem accelerator (2 × 3MV) in the laboratory. In this paper, the developing progress of the FUDAN microbeam is reported, including the newly constructed beam line, the microbeam collimator, the ion detection system, and the cell-imaging and targeting systems. Statistical models are proposed for evaluating the spatial resolution and dosage precision of the microbeam. By taking the collimated ions as a Gaussian beam, the spatial resolution can be evaluated by the full width at half maximum of the 2-D Gaussian distribution, which is determined by fitting the proportions of peripheral pits outside specific radii in the pit clusters etched on ion track detectors to a 2-D Gaussian distribution. In the preset hitting of defined ion number, by taking the real delivered number of ions as an independent identically distributed random variable (iidrv), according to the Law of Large Numbers and Central Limit Theorem, the expected value µ and standard deviation σ of the real delivered ion number in a preset N-ion hitting can be determined by approaching the normal distribution of N (µ, σ (2)/n) with the proportions of the mean counts of pits in multiple pit clusters on ion track detectors. By the values of µ, σ and additional assumptions, statistical dosage precision evaluations can be made on the preset hitting. From the linear fit curve of µ(N) and the power function fit curve of σ(N) on different preset ion numbers, characteristic factors k, b, A, p can be extracted for a precision evaluation independent of the specific preset ion number.
Assuntos
Radiobiologia/instrumentação , Células/metabolismo , Células/efeitos da radiação , Imagem Molecular , Fenômenos Ópticos , Doses de RadiaçãoRESUMO
Cadmium (Cd) is the major component of polluted environment, which has numerous undesirable effects on health. Cd could induce apoptosis of HEK293 cells, and the mitochondria may play a key role. However, the mode of action is unclear. In the present study, we aimed to evaluate the ability of the Cd to induce dysfunction of mitochondria. We examined the effect of cadmium chloride (1, 5 and 10 µM) on mitochondrial membrane permeability and potential as well as oxidative stress markers in mitochondria isolated from HEK293 cells. We found that Cd could directly increase in permeability and decrease in membrane potential of mitochondria, even resulted in mitochondrial swelling, and that Cd could inhibit the activities of ATPase, lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), enhanced the levels of reactive oxygen species (ROS) and lipid peroxidation (LPO). On the whole, the results show that Cd can directly lead to mitochondrial dysfunction of HEK293 cells, including increased permeability, inhibiting respiration and evoking oxidative stress. Thus, for the first time, this paper makes an overall analysis of Cd-induced changes of structure and function of isolated mitochondria. Our findings may also have general implications in Cd-induced apoptosis by mitochondria pathway.
Assuntos
Apoptose/efeitos dos fármacos , Cloreto de Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Mitocôndrias/efeitos dos fármacos , Adenosina Trifosfatases/metabolismo , Técnicas de Cultura de Células , Células HEK293 , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Proteínas Mitocondriais/metabolismo , Dilatação Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismoRESUMO
A biological system is often more efficient when it takes advantage of the regularities in its environment. Like other terrestrial creatures, our spatial sense relies on the regularities associated with the ground surface. A simple, but important, ecological fact is that the field of view of the ground surface extends upwards from near (feet) to infinity (horizon). It forms the basis of a trigonometric relationship wherein the further an object on the ground is, the higher in the field of view it looks, with an object at infinity being seen at the horizon. Here, we provide support for the hypothesis that the visual system uses the angular declination below the horizon for distance judgement. Using a visually directed action task, we found that when the angular declination was increased by binocularly viewing through base-up prisms, the observer underestimated distance. After adapting to the same prisms, however, the observer overestimated distance on prism removal. Most significantly, we show that the distance overestimation as an after-effect of prism adaptation was due to a lowered perceived eye level, which reduced the object's angular declination below the horizon.
Assuntos
Percepção de Distância/fisiologia , Acomodação Ocular , Escuridão , Humanos , Iluminação , Modelos Neurológicos , Visão Binocular/fisiologiaRESUMO
In four experiments, the effects of sequential priming on the perceptual organization of complex three-dimensional (3-D) displays were examined. Observers were asked to view stereoscopic arrays and to search an embedded subset of items for an odd-colored target while 3-D orientation of the stimuli was varied randomly between trials. Search times decreased reliably when 3-D stimulus orientation was unchanged on consecutive trials, indicating substantial sequential priming by 3-D stimulus layout. The priming was nonsensory and was independent of priming by additional stimulus characteristics. Finally, priming by 3-D layout was unaffected by observers' foreknowledge of display orientation. Results indicate that perceptual organization of 3-D stimuli is guided by a short-term trace of 3-D spatial relationships between stimuli.
Assuntos
Atenção , Percepção de Cores , Percepção de Profundidade , Área de Dependência-Independência , Reconhecimento Visual de Modelos , Adulto , Feminino , Humanos , Masculino , Rememoração Mental , Orientação , PsicofísicaRESUMO
BACKGROUND: Sensory eye dominance is revealed in tasks like the Red Lens test and binocular rivalry. To understand its neural basis, we used a new protocol based on binocular rivalry to quantify its consequent interocular imbalance. Then we investigated whether the extent or sign of interocular imbalance is correlated with the difference in monocular contrast responses at threshold and suprathreshold and with the observer's motor eye dominance. METHODS: To evaluate sensory eye dominance, the stimulus intensity in each eye during rivalry was adjusted to achieve equal predominance. The difference in stimulus intensity constitutes the interocular imbalance. Standard procedures were used to measure monocular spatial contrast sensitivity, suprathreshold brightness judgment, and motor eye dominance. RESULTS: There was no positive correlation between interocular imbalance (sensory eye dominance) and motor eye dominance. No systematic correlation was found between interocular imbalance and monocular contrast sensitivities at 1 and 3 cycles/degree. Correlation coefficient between interocular imbalance and monocular suprathreshold brightness judgment was close to significant, suggesting that a difference in monocular brightness percept might (in part) account for interocular imbalance. But this explanation is only partial, since the difference in the monocular brightness percept was too small to account for the interocular imbalance. CONCLUSIONS: Interocular imbalance is a sensory eye dominance that cannot be equated with motor eye dominance. It manifests largely as a binocular phenomenon, which bears little relationship with the monocular neural mechanisms of contrast detection and brightness perception.
Assuntos
Fenômenos Fisiológicos Oculares , Percepção Visual/fisiologia , Adulto , Sensibilidades de Contraste/fisiologia , Movimentos Oculares/fisiologia , Humanos , Variações Dependentes do Observador , Músculos Oculomotores/fisiologia , Estimulação Luminosa , Valores de Referência , Limiar Sensorial/fisiologia , Disparidade Visual/fisiologia , Visão Binocular/fisiologiaRESUMO
Exogenous acetaldehyde infusion can induce pancreatitis-like injury of the pancreas in some isolated pancreas models, whereas in vivo such treatment has failed to induce pancreatitis. In vivo exogenous acetaldehyde may not be effective because it is rapidly metabolized. The aim of this study was to investigate whether endogenous acetaldehyde accumulates in the pancreas after ethanol feeding when acetaldehyde metabolism is blocked by disulfiram, and whether this treatment can induce pancreatitis-like injury in the rat. The liver was studied for comparison. In part I of the experiment, adult male Wistar rats were given water (n = 24), ethanol (n = 24), disulfiram (n = 24), and ethanol plus disulfiram for 1 week (n = 24) or 3 weeks (n = 24) and for 3 weeks with (n = 6) and without (n = 6) hypovolemia. In part II of the experiment, rats were given water (n = 6), ethanol (n = 6), and high-dose disulfiram (n = 6) and ethanol plus high-dose disulfiram (n = 6). Ethanol and acetaldehyde concentrations in blood, liver, and pancreas were measured. Animal behavior was monitored, and weight changes, plasma amylase activity, water content, and histomorphology of the pancreas and liver were studied without knowing the group. No increases in plasma amylase activity and no histomorphologic changes in the pancreas were observed under light or electron microscopy in part I of the experiment. In part II, treatment with ethanol induced acetaldehyde accumulation in the liver (33.6 +/- 2.6 micromol/L), but to a lesser degree in the blood (9.6 +/- micromol/L) and pancreas (5.0 +/-.2 micromol/L). Ethanol plus disulfiram induced marked accumulation of acetaldehyde in the liver (83.2 +/- 15.9 micromol/L), blood (280.0 +/- 47.4 micromol/L), and pancreas (43.6 +/- 4.7 micromol/L). When tissue acetaldehyde levels reached 30 to 40 micromol/L, we found a decrease in zymogen granules along with formation of small intracytoplasmic vacuolizations in the acinar cells and accumulation of lipid droplets in the hepatocytes, whereas physiologic signs of pancreatitis (hyperamylasemia, edema) or increases in liver enzymes did not develop. High levels of acetaldehyde accumulate in the liver and pancreas with the treatment described. Although this was accompanied by lipid degeneration of the hepatocytes and some subcellular changes in the acinar cells, physiologic signs of pancreatitis did not develop. Thus acetaldehyde accumulation alone, or in combination with hypovolemia, is not responsible for the induction of acute pancreatitis.
Assuntos
Acetaldeído/metabolismo , Dissulfiram/farmacologia , Etanol , Pâncreas/metabolismo , Animais , Comportamento Animal , Hepatócitos/ultraestrutura , Metabolismo dos Lipídeos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Microscopia Eletrônica , Pâncreas/efeitos dos fármacos , Pâncreas/ultraestrutura , Ratos , Ratos WistarRESUMO
Attneave (1954) and Barlow (1961) proposed that the visual system might increase efficiency of representation by preferentially encoding spatiotemporally redundant patterns of the external world. The present experiments tested the application of this principle to three-dimensional (3-D) perceptual organization, capitalizing on the ecological constraint that human observers must frequently interact with objects arranged on the ground or on a surface parallel to it (Gibson, 1950). Observers performed a task that required them to perceptually segregate and search multiple items distributed in depth and embedded within a larger, 3-D array of distractors. Stimulus displays were organized to globally recede top-away in depth, as if attached to an underlying ground-like surface, or bottom-away, as if attached to an overhanging ceiling-like surface; ground-like and ceiling-like displays differed only in the direction of disparity gradient within the displays. Primary findings revealed superior performance with ground-like displays, suggesting that spatially and stereoscopically distributed items are more easily organized to represent an ecologically representative pattern, even when no inherent physical regularities favor that pattern.
Assuntos
Percepção de Profundidade , Área de Dependência-Independência , Orientação , Reconhecimento Visual de Modelos , Adulto , Feminino , Humanos , Masculino , Psicofísica , Disparidade VisualRESUMO
BACKGROUND: Apoptosis may be involved in the mechanism of acinar cell injury in acute experimental pancreatitis. AIM: This study was to investigate whether apoptosis also is involved in human acute pancreatitis. METHOD: A needle biopsy pancreatic specimen was obtained from a patient with acute oedematous pancreatitis. The specimen was stained with In Situ Cell Death Detection Kit. Similar specimen from a patient undergoing pancreatoduodenectomy for bile duct cancer served as a control. RESULTS: Extended acinar cell apoptosis was found in the pancreatitis specimen. No single apoptotic cell was found in the control pancreas. CONCLUSION: Apoptosis probably is involved not only in acute experimental pancreatitis but also in human acute oedematous pancreatitis. The induction and role of apoptosis in pancreatis is discussed based on literature.
Assuntos
Apoptose , Pancreatite/fisiopatologia , Doença Aguda , Adulto , Biópsia por Agulha , Humanos , Masculino , Pancreatite/patologiaRESUMO
BACKGROUND AND AIMS: This study was to assess whether the tissue obtained with an ultrathin cutting needle, that is as thin as used for aspiration cytology and bacteriology, can give enough material to diagnose acute pancreatitis in rat model and in a human case. METHODS: Wistar rats were randomly allocated into control group (n = 6), cerulein group (n = 6), ligation group (n = 6) and bile salt group (n = 6). In the cerulein, ligation and bile salt groups acute pancreatitis was induced by cerulein intraperitoneal injections, low ligation of common biliopancreatic duct and sodium taurodeoxycholate intraductal injection, respectively. Serum amylase activity was measured and a large cut specimen and two ultrathin needle biopsy specimens were obtained from the pancreas for light microscopic histology. Oedema, acinar cell necrosis, haemorrhage or fat necrosis, and leukocyte infiltration were evaluated semiquantitatively and compared with large cut specimens. RESULTS: The pancreatitis groups revealed different severity in oedema, acinar cell necrosis, haemorrhage or fat necrosis, and leukocyte infiltration. The needle biopsy showed 100% sensitivity and 100% specificity in the diagnosis of acute pancreatitis. The histopathologic scores showed a good and significant correlation between ultrathin biopsy and large cut specimens in all the four histologic parameters, especially in oedema and acinar cell necrosis. A human case is presented, whose percutaneous ultrathin needle biopsy histology was successfully applied for diagnosing acute pancreatitis. CONCLUSIONS: The ultrathin needle biopsy histology can give enough material for the diagnosis of acute pancreatitis. Further studies with ultrasonography guided percutanous or endosonography guided transduodenal technique will be needed to assess the role of tissue sampling in acute pancreatitis.
Assuntos
Biópsia por Agulha , Pancreatite/patologia , Doença Aguda , Adulto , Animais , Biópsia , Edema/patologia , Desenho de Equipamento , Humanos , Masculino , Necrose , Ratos , Ratos Wistar , Índice de Gravidade de DoençaRESUMO
A common surface is a spatial regularity of our terrestrial environment. For instance, we walk on the common ground surface, lay a variety of objects on the table top, and display our favorite paintings on the wall. It has been proposed that the visual system utilizes this regularity as a reference frame for coding objects' distances. Presumably, by treating the common surface as such--i.e. an anticipated constant--the visual system can reduce its coding redundancy, and divert its resources to representing other information. For intermediate-distance space perception, it has been found that absolute distance judgment is most accurate when a common ground surface is available. Here we explored if the common surface also serves as the reference frame for the processing of binocular-disparity information, which is a predominant cue for near-distance space perception. We capitalized on an established observation where the perceived slant of a surface with linear binocular-disparity gradient is underestimated. Clearly, if the visual system utilizes this incorrectly represented slant surface as a reference frame for coding the objects' locations, the perceived depth separation between the objects will be adversely affected. Our results confirm this, by showing that the depth judgment of objects (two laterally separated vertical lines) on, or in the vicinity of, the surface is underestimated. Furthermore, we show that the impact of the common surface on perceived depth separation most likely occurs at the surface-representation level where the visual surface has been explicitly delineated, rather than at the earlier disparity-processing level.
Assuntos
Percepção de Profundidade/fisiologia , Visão Binocular/fisiologia , Sinais (Psicologia) , Humanos , Estimulação Luminosa/métodos , Disparidade Visual/fisiologiaRESUMO
BACKGROUND AND AIMS: Multiorgan function failures are the major fatal complications in acute pancreatitis. In this experiment, we studied 1) the manifestation and time course of extrapancreatic organ damage in an acute pancreatitis model and 2) whether the obstructive liver damage in this model is caused by the obstruction of common biliopancreatic duct compressed by oedematous pancreas. MATERIAL AND METHODS: 80 male Wistar rats were divided into two groups: control and caerulein groups (five subgroups in each group). In the caerulein group, the acute pancreatitis was induced by caerulein intraperitoneal injections. In the controls equal volume of saline was injected. Two subgroups, one in caerulein and one in control groups, had an intrapancreatic bile duct stent inserted transduodenally before the injections. The pancreas, liver, lung and kidney tissues and blood samples were obtained for the measurement or analysis of interstitial oedema, plasma amylase, alanine aminotransferase, bilirubin, urea, creatinine, alkaline phosphatase, lactate dehydrogenase, blood gas and electron microscopy at 1, 6, 12 and 24 hours after the last injection in unstented animals, and at 6 hours in stented animals. RESULTS: Lungs and kidney remained unchanged. Liver damage was found during the first 6-12 hours, manifest as increased plasma alanine aminotransferase and bilirubin and dilatation of bile canaliculi and hepatocyte damage in electron microscopy. The intrapancreatic bile duct stent did not resolve these changes. CONCLUSIONS: The liver may be the first evolved extrapancreatic organ in the early stage in this mild oedematous pancreatitis model and the hepatocyte damage is not caused by the obstruction of common biliopancreatic duct compressed by the oedematous pancreas.
Assuntos
Ceruletídeo/toxicidade , Colestase Extra-Hepática/induzido quimicamente , Fármacos Gastrointestinais/toxicidade , Pancreatite/induzido quimicamente , Animais , Colestase Extra-Hepática/patologia , Ducto Colédoco/efeitos dos fármacos , Ducto Colédoco/patologia , Injeções Intraperitoneais , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Microscopia Eletrônica , Insuficiência de Múltiplos Órgãos/induzido quimicamente , Insuficiência de Múltiplos Órgãos/patologia , Pâncreas/efeitos dos fármacos , Pâncreas/patologia , Pancreatite/patologia , Ratos , Ratos Wistar , StentsRESUMO
When the right eye and the left eye view dissimilar scenes, the observer does not experience a stable superimposed percept of the images presented to the two eyes, but instead perceives an alternation between the images seen by each eye. A critical question confronting this robust and intriguing phenomenon of binocular rivalry is how the visual system selects the image to be perceived (dominant). The current main-stream literature emphasizes a bottom-up explanation in which the rivalry stimulus with the higher contour strength has the advantage, and becomes dominant in rivalry. Nevertheless, some workers in the past have favored an attention-selection explanation for binocular rivalry. We investigated the role of attention in binocular rivalry by employing novel psychophysical paradigms which capitalized on several established phenomena (e.g. the Cheshire Cat effect, attention cueing, pop-out effect). Our results revealed two major aspects of attention modulation in binocular rivalry. We found that a dominant image is less likely to be suppressed when voluntary attention is directed to it. This suggests the role of voluntary attention in retaining the dominant image in visual awareness. Second, a rivalry stimulus is more likely to become dominant if accompanied by a pop-out cue (in the same eye and proximity). Since a pop-out cue attracts involuntary attention to its location/eye, this result suggests that cue-mediated involuntary attention can promote the ability of a rivalry stimulus to reach visual awareness.