FOT Technique Applied for Monitoring of COVID-19 Pneumonia Reveals Small Airways Involvement.

The fact that some SARS-CoV-2 pneumonia patients benefit from changing body position, and some from continuous positive airways pressure (CPAP), indicates the functional character of hypoxia. We hypothesize that such effects could be explained by the closure of small airways. To prove the hypothesis, we evaluated the patency of small airways in 30 oxygen-dependent, spontaneously breathing patients with SARS-CoV-2 pneumonia during their hospital stay using the FOT method and then compared the results with data obtained three months later. During the acute period, total resistance (R5) and peripheral resistance (R5-20) rose above the upper limit of normal (ULN) in 28% and 50% of all patients, respectively. Reactance indices X5, AX and Fres exceeded ULN in 55%, 68% and 66% of cases. Significant correlations were observed between PaO2/FiO2, the time spent in the hospital and R5, X5, AX and Fres. After 3 months, 18 patients were re-examined. During the hospital stay, 11 of them had risen above the upper limit of normal (ULN), for both resistance (R5-20) and reactance (X5, AX) values. Three months later, ULN for R5-20 was exceeded in only four individuals, but ULN for X5 and AX was exceeded in five individuals. Lung function examination revealed a combined restrictive/obstructive ventilatory failure and reduced CO transfer factor. We interpret these changes as lung tissue remodeling due to the process of fibrosis. We conclude that during acute period of SARS-CoV-2 pneumonia, dilated pulmonary blood vessels and parenchymal oedema induce functional closure of small airways, which in turn induce atelectasis with pulmonary right-to-left shunting, followed by the resulting hypoxemia.

Nucleus accumbens D1-receptors regulate and focus transitions to reward-seeking action.

It is well established that dopamine transmission is integral in mediating the influence of reward expectations on reward-seeking actions. However, the precise causal role of dopamine transmission in moment-to-moment reward-motivated behavioral control remains contentious, particularly in contexts where it is necessary to refrain from responding to achieve a beneficial outcome. To examine this, we manipulated dopamine transmission pharmacologically as rats performed a Go/No-Go task that required them to either make or withhold action to gain either a small or large reward. D1R Stimulation potentiated cue-driven action initiation, including fast impulsive actions on No-Go trials. By contrast, D1R blockade primarily disrupted the successful completion of Go trial sequences. Surprisingly, while after global D1R blockade this was characterized by a general retardation of reward-seeking actions, nucleus accumbens core (NAcC) D1R blockade had no effect on the speed of action initiation or impulsive actions. Instead, fine-grained analyses showed that this manipulation decreased the precision of animals' goal-directed actions, even though they usually still followed the appropriate response sequence. Strikingly, such "unfocused" responding could also be observed off-drug, particularly when only a small reward was on offer. These findings suggest that the balance of activity at NAcC D1Rs plays a key role in enabling the rapid activation of a focused, reward-seeking state to enable animals to efficiently and accurately achieve their goal.

5-HT2C receptor perturbation has bidirectional influence over instrumental vigour and restraint.

The serotonin (5-HT) system, particularly the 5-HT2C receptor, has consistently been implicated in behavioural control. However, while some studies have focused on the role 5-HT2C receptors play in regulating motivation to work for reward, others have highlighted its importance in response restraint. To date, it is unclear how 5-HT transmission at this receptor regulates the balance of response invigoration and restraint in anticipation of future reward. In addition, it remains to be established how 5-HT2C receptors gate the influence of internal versus cue-driven processes over reward-guided actions. To elucidate these issues, we investigated the effects of administering the 5-HT2C receptor antagonist SB242084, both systemically and directly into the nucleus accumbens core (NAcC), in rats performing a Go/No-Go task for small or large rewards. The results were compared to the administration of d-amphetamine into the NAcC, which has previously been shown to promote behavioural activation. Systemic perturbation of 5-HT2C receptors-but crucially not intra-NAcC infusions-consistently boosted rats' performance and instrumental vigour on Go trials when they were required to act. Concomitantly, systemic administration also reduced their ability to withhold responding for rewards on No-Go trials, particularly late in the holding period. Notably, these effects were often apparent only when the reward on offer was small. By contrast, inducing a hyperdopaminergic state in the NAcC with d-amphetamine strongly impaired response restraint on No-Go trials both early and late in the holding period, as well as speeding action initiation. Together, these findings suggest that 5-HT2C receptor transmission, outside the NAcC, shapes the vigour of ongoing goal-directed action as well as the likelihood of responding as a function of expected reward.

Lesiones orales de sífilis secundaria limitada a la cavidad oral: informe de un caso / Oral lesions of secondary syphilis restricted to the oral cavity: report of a case

Objetivo: Describir un caso clínico de sífilis secundaria localizada en cavidad oral. Caso clínico: Un paciente masculino de 24 años, proveniente de Joaquín V. González, provincia de Salta, fue derivado a Unidad de Estomatología del Hospital Señor del Milagro, con manifestaciones orales de una semana de evolución. Clínicamente, se observaron lesiones blancas opalinas, indoloras, compatibles con pápulas sifilíticas, en diferentes ubicaciones orales. Se realizaron estudios serológicos que confirmaron el diagnóstico de sífilis secundaria. El paciente fue derivado al Servicio de Infectología, donde recibió tratamiento con una dosis de penicilina G benzatínica 2.400.000 UI intramuscular, con repuesta clínica favorable. Conclusión: El conocimiento de las manifestaciones orales puede llevar al diagnóstico clínico de la sífilis secundaria por parte del odontólogo, lo cual, junto con su tratamiento oportuno, puede evitar la transmisión de la enfermedad. El diagnóstico precoz es la mejor manera de ayudar al paciente y de prevenir las complicaciones (AU)

Neurocomputational mechanisms underlying subjective valuation of effort costs.

In everyday life, we have to decide whether it is worth exerting effort to obtain rewards. Effort can be experienced in different domains, with some tasks requiring significant cognitive demand and others being more physically effortful. The motivation to exert effort for reward is highly subjective and varies considerably across the different domains of behaviour. However, very little is known about the computational or neural basis of how different effort costs are subjectively weighed against rewards. Is there a common, domain-general system of brain areas that evaluates all costs and benefits? Here, we used computational modelling and functional magnetic resonance imaging (fMRI) to examine the mechanisms underlying value processing in both the cognitive and physical domains. Participants were trained on two novel tasks that parametrically varied either cognitive or physical effort. During fMRI, participants indicated their preferences between a fixed low-effort/low-reward option and a variable higher-effort/higher-reward offer for each effort domain. Critically, reward devaluation by both cognitive and physical effort was subserved by a common network of areas, including the dorsomedial and dorsolateral prefrontal cortex, the intraparietal sulcus, and the anterior insula. Activity within these domain-general areas also covaried negatively with reward and positively with effort, suggesting an integration of these parameters within these areas. Additionally, the amygdala appeared to play a unique, domain-specific role in processing the value of rewards associated with cognitive effort. These results are the first to reveal the neurocomputational mechanisms underlying subjective cost-benefit valuation across different domains of effort and provide insight into the multidimensional nature of motivation.

Action initiation shapes mesolimbic dopamine encoding of future rewards.

It is widely held that dopamine signaling encodes predictions of future rewards and such predictions are regularly used to drive behavior, but the relationship between these two is poorly defined. We found in rats that nucleus accumbens dopamine following a reward-predicting cue was attenuated unless movement was correctly initiated. Our results indicate that dopamine release in this region is contingent on correct action initiation and not just reward prediction.

The role of cognitive effort in subjective reward devaluation and risky decision-making.

Motivation is underpinned by cost-benefit valuations where costs-such as physical effort or outcome risk-are subjectively weighed against available rewards. However, in many environments risks pertain not to the variance of outcomes, but to variance in the possible levels of effort required to obtain rewards (effort risks). Moreover, motivation is often guided by the extent to which cognitive-not physical-effort devalues rewards (effort discounting). Yet, very little is known about the mechanisms that underpin the influence of cognitive effort risks or discounting on motivation. We used two cost-benefit decision-making tasks to probe subjective sensitivity to cognitive effort (number of shifts of spatial attention) and to effort risks. Our results show that shifts of spatial attention when monitoring rapidly presented visual stimuli are perceived as effortful and devalue rewards. Additionally, most people are risk-averse, preferring safe, known amounts of effort over risky offers. However, there was no correlation between their effort and risk sensitivity. We show for the first time that people are averse to variance in the possible amount of cognitive effort to be exerted. These results suggest that cognitive effort sensitivity and risk sensitivity are underpinned by distinct psychological and neurobiological mechanisms.

Satisfacción en la comunicación del personal de enfermería / Satisfaction in the communication among the nursing staff

En la presente investigación se trató de conocer el grado de satisfacción del cliente interno de enfermería, según la comunicación con distintos actores involucrados con la realidad del Servicio de Maternidad de un hospital público de la provincia argentina de Catamarca. Se pudo concluir que hay una relación inversamente proporcional, entre la satisfacción y los niveles de conducción de enfermería. Es decir que a medida que se eleva el grado de conducción disminuye el de satisfacción y, por ende, se eleva el de insatisfacción. Sólo la comunicación con el paciente y la familia, y entre pares, fue reconocida por el personal como satisfactoria

Satisfacción en la comunicación del personal de enfermería / Satisfaction in the communication among the nursing staff

En la presente investigación se trató de conocer el grado de satisfacción del cliente interno de enfermería, según la comunicación con distintos actores involucrados con la realidad del Servicio de Maternidad de un hospital público de la provincia argentina de Catamarca. Se pudo concluir que hay una relación inversamente proporcional, entre la satisfacción y los niveles de conducción de enfermería. Es decir que a medida que se eleva el grado de conducción disminuye el de satisfacción y, por ende, se eleva el de insatisfacción. Sólo la comunicación con el paciente y la familia, y entre pares, fue reconocida por el personal como satisfactoria (AU)