Knowledge, Attitude and Practice of Undergraduate Medical Students of Bangladesh Regarding COVID-19 and its Vaccination.

Medical students are one of the socially active, reliable, and persuading population of information, prevention and control, and incentive of vaccination to stop the current pandemic situation. Consequently, knowing the status of medical students' knowledge, about symptoms, and transmission of disease, prevention of COVID-19 and their attitudes towards a vaccine is important. This multi-center cross-sectional descriptive study was one of the first ones in Bangladesh among the undergraduate medical students who completed pathology, microbiology, and pharmacology. The study was conducted from March to April 2021, using a convenience sampling method in twelve government and non-government medical colleges. Among 1132 who completed the questionnaire, and 15 students from different centers were excluded from the pre-testing and face validation. The age of the 1117 respondents were 22 to 23 years, of which the majority of the respondents were female 749 (67.0%), and 368 (33.0%) were male. Almost all participants had correct knowledge (84.1%) about the symptoms of COVID-19. But 59.2% had wrong knowledge about transmission of disease by an afebrile person. Above 60.0 % of the participants have worn a facial mask when contacting people, refrained from shaking hands, washed hands, avoided people with signs and symptoms suggestive of COVID-19, and avoided crowded places as a practice of prevention. 37.6% of medical students showed positive attitudes about the participation of management of a COVID-19 patient. Most of the participants' decided to have a vaccine depending on its availability. But 31.5% had trust in natural immunity rather than vaccination. Most undergraduate Medical college students understood the basic information, possessed a positive attitude, and presented good practice towards the COVID-19 and vaccination. They play a crucial role in motivation and acceptance of vaccines among the general citizen to fight back against the pandemic in the country with limited resources.

Biologically predisposed learning and selective associations in amygdalar neurons.

Modern views on learning and memory accept the notion of biological constraints-that the formation of association is not uniform across all stimuli. Yet cellular evidence of the encoding of selective associations is lacking. Here, conditioned stimuli (CSs) and unconditioned stimuli (USs) commonly employed in two basic associative learning paradigms, fear conditioning and taste aversion conditioning, were delivered in a manner compatible with a functional cellular imaging technique (Arc cellular compartmental analysis of temporal gene transcription by fluorescence in situ hybridization [catFISH]) to identify biological constraints on CS-US convergence at the level of neurons in basolateral amygdala (BLA). Results indicate coincident Arc mRNA activation within BLA neurons after CS-US combinations that yield rapid, efficient learning, but not after CS-US combinations that do not.

Visualizing stimulus convergence in amygdala neurons during associative learning.

A central feature of models of associative memory formation is the reliance on information convergence from pathways responsive to the conditioned stimulus (CS) and unconditioned stimulus (US). In particular, cells receiving coincident input are held to be critical for subsequent plasticity. Yet identification of neurons in the mammalian brain that respond to such coincident inputs during a learning event remains elusive. Here we use Arc cellular compartmental analysis of temporal gene transcription by fluorescence in situ hybridization (catFISH) to locate populations of neurons in the mammalian brain that respond to both the CS and US during training in a one-trial learning task, conditioned taste aversion (CTA). Individual neurons in the basolateral nucleus of the amygdala (BLA) responded to both the CS taste and US drug during conditioning. Coincident activation was not evident, however, when stimulus exposure was altered so as to be ineffective in promoting learning (backward conditioning, latent inhibition). Together, these data provide clear visualization of neurons in the mammalian brain receiving convergent information about the CS and US during acquisition of a learned association.

Efficacy of F-75 & F-100 Recipes in theTreatment of Severe Acute Malnutrition: A Randomized Controlled Trial.

Severe malnutrition is an important cause of death in children. According to new WHO-growth chart 2006, the proportion of children with severe wasting is 3.1% thus the total number being 4, 65000 (BDHS 2014). Overall risk of death among children with severe acute malnutrition (SAM) is 9 times more than well nourished children. The death rate among hospitalized children of SAM was as high as 15%. Once properly treated, severely malnourished children would grow up leading a normal life. Severe malnutrition in children can be successfully treated by using WHO guidelines that have been shown to be feasible and sustainable even in small district hospital with limited resources. A randomized controlled trial was conducted at department of Pediatrics, Dhaka Medical College Hospital, Dhaka, Bangladesh from July 2014 to September 2015. The trial enrolled 92 SAM patients (46 cases + 46 controls) aged 06 months to 59 months of either sex who meet the inclusion criteria consecutively. Enrolled children were randomized by lottery method into two groups, Group I and Group II. Patients in Group I was treated with F-75 and F-100 recipes and managed in two phases, initial stabilization phase with F-75 recipes then subsequently rehabilitation phase by F-100 recipes. Patients in Group II was treated with prepackaged F-75 & F-100 formulae and feeding was given in two phases i.e. initial stabilization phase and subsequently rehabilitation phase according to national guidelines for the management of severe malnourished children. Then play therapy was given for half an hour daily with red colored toy in Ashic play centre Dhaka Medical College Hospital for patients of both groups. The time (days) taken to return of appetite (mean±SD) was 5.1±1.16 and 4.8±1.34 in Group I and Group II respectively, disappearance of edema (mean±SD) 4.8±1.53 in and 4.9±1.05 for Group I Group II respectively, to gain target weight (mean±SD) 13.8±2.20 days and 13.5±1.74 days in Group I and Group II respectively, rate of weight gain (mean±SD) 17.70±7.07gm/kg/day for Group I and 16.20±4.63gm/kg/day for Group II. The side effects, diarrhea was equal in both group, vomiting was more in Group II, combined diarrhea and vomiting was more in Group I but the differences were not statistically significant. The treatment cost (mean±SD) was higher in Group II (97.2±78.24 BDT/child/day) than in Group I (58.5±54.36 BDT/child/day). Return of appetite and disappearance of oedema and target weight gain were similar in both groups but treatment cost was higher in Group II than Group I, which was statistically significant.

Stress-induced p38 mitogen-activated protein kinase activation mediates kappa-opioid-dependent dysphoria.

The molecular mechanisms mediating stress-induced dysphoria in humans and conditioned place aversion in rodents are unknown. Here, we show that repeated swim stress caused activation of both kappa-opioid receptor (KOR) and p38 mitogen-activated protein kinase (MAPK) coexpressed in GABAergic neurons in the nucleus accumbens, cortex, and hippocampus. Sites of activation were visualized using phosphoselective antibodies against activated kappa receptors (KOR-P) and against phospho-p38 MAPK. Surprisingly, the increase in P-p38-IR caused by swim-stress exposure was completely KOR dependent; P-p38-IR did not increase in KOR(-/-) knock-out mice subjected to the same swim-paradigm or in wild-type mice pretreated with the KOR antagonist norbinaltorphimine. To understand the relationship between p38 activation and the behavioral effects after KOR activation, we administered the p38 inhibitor SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfonylphenyl)-5-(4-pyridyl)-1H-imidazole (i.c.v.)] and found that it selectively blocked the conditioned place aversion caused by the kappa agonist trans-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-benzeneacetamide (U50488) and the KOR-dependent swim stress-induced immobility while not affecting kappa-opioid analgesia or nonselectively affecting associative learning. We found that the mechanism linking KOR and p38 activation in vivo was consistent with our previous in vitro data suggesting that beta-arrestin recruitment is required; mice lacking G-protein-coupled receptor kinase 3 also failed to increase p-p38-IR after KOR activation in vivo, failed to show swim stress-induced immobility, or develop conditioned place aversion to U50488. Our results indicate that activation of p38 MAPK signaling by the endogenous dynorphin-kappa-opioid system likely constitutes a key component of the molecular mechanisms mediating the aversive properties of stress.

Polycose taste pre-exposure fails to influence behavioral and neural indices of taste novelty.

Taste novelty can strongly modulate the speed and efficacy of taste aversion learning. Novel sweet tastes enhance c-Fos-like immunoreactivity (FLI) in the central amygdala and insular cortex. The present studies examined whether this neural correlate of novelty extends to different taste types by measuring FLI signals after exposure to novel and familiar polysaccharide (Polycose) and salt (NaCl) tastes. Novel Polycose not only failed to elevate FLI expression in central amygdala and insular cortex, but also failed to induce stronger taste aversion learning than familiar Polycose. Novel NaCl, on the other hand, showed patterns of FLI activation and aversion learning similar to that of novel sweet tastes. Possible reasons for the resistance of Polycose to typical pre-exposure effects are discussed.

Functional imaging of stimulus convergence in amygdalar neurons during Pavlovian fear conditioning.

BACKGROUND: Associative conditioning is a ubiquitous form of learning throughout the animal kingdom and fear conditioning is one of the most widely researched models for studying its neurobiological basis. Fear conditioning is also considered a model system for understanding phobias and anxiety disorders. A fundamental issue in fear conditioning regards the existence and location of neurons in the brain that receive convergent information about the conditioned stimulus (CS) and unconditioned stimulus (US) during the acquisition of conditioned fear memory. Convergent activation of neurons is generally viewed as a key event for fear learning, yet there has been almost no direct evidence of this critical event in the mammalian brain. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used Arc cellular compartmental analysis of temporal gene transcription by fluorescence in situ hybridization (catFISH) to identify neurons activated during single trial contextual fear conditioning in rats. To conform to temporal requirements of catFISH analysis we used a novel delayed contextual fear conditioning protocol which yields significant single- trial fear conditioning with temporal parameters amenable to catFISH analysis. Analysis yielded clear evidence that a population of BLA neurons receives convergent CS and US information at the time of the learning, that this only occurs when the CS-US arrangement is supportive of the learning, and that this process requires N-methyl-D-aspartate receptor activation. In contrast, CS-US convergence was not observed in dorsal hippocampus. CONCLUSIONS/SIGNIFICANCE: Based on the pattern of Arc activation seen in conditioning and control groups, we propose that a key requirement for CS-US convergence onto BLA neurons is the potentiation of US responding by prior exposure to a novel CS. Our results also support the view that contextual fear memories are encoded in the amygdala and that the role of dorsal hippocampus is to process and transmit contextual CS information.

5-HT(1B) receptors in nucleus accumbens efferents enhance both rewarding and aversive effects of cocaine.

Whether serotonin-1B (5-HT(1B)) receptor activation enhances or diminishes the reinforcing properties of psychostimulants remains unclear. We have previously shown that increased expression of 5-HT(1B) receptors in nucleus accumbens (NAcc) shell neurons sensitized rats to the locomotor-stimulating and rewarding properties of cocaine. In this study we further examined the contribution of 5-HT(1B) receptors on the effect of cocaine under conditions intended to selectively influence either conditioned place preference or avoidance (CPP or CPA, respectively). Viral-mediated gene transfer techniques were used to overexpress 5-HT(1B) receptors in medial NAcc shell medium spiny neurons projecting to the ventral tegmental area. Animals were then conditioned to associate place cues with the effects of either a low (5 mg/kg) or moderately high (20 mg/kg) dosage of cocaine immediately or 45 min after intraperitoneal cocaine administration. Animals with increased 5-HT(1B) expression showed cocaine-induced CPP immediately after administration of the low 5 mg/kg dose of cocaine, but a CPA 45 min after administration of the high 20 mg/kg dose. Control animals showed no preference at the 5 mg/kg dose and a significant preference at 20 mg/kg. Given this, we believe that increased 5-HT(1B) receptor activation in NAcc shell projection neurons intensifies both the rewarding and negative properties of cocaine use.