The Impact of Inflammation and General Anesthesia on Memory and Executive Function in Mice.

BACKGROUND: Perioperative neurocognitive disorders (PNDs) are complex, multifactorial conditions that are associated with poor long-term outcomes. Inflammation and exposure to general anesthetic drugs are likely contributing factors; however, the relative impact of each factor alone versus the combination of these factors remains poorly understood. The goal of this study was to compare the relative impact of inflammation, general anesthesia, and the combination of both factors on memory and executive function. METHODS: To induce neuroinflammation at the time of exposure to an anesthetic drug, adult male mice were treated with lipopolysaccharide (LPS) or vehicle. One day later, they were anesthetized with etomidate (or vehicle). Levels of proinflammatory cytokines were measured in the hippocampus and cortex 24 hours after LPS treatment. Recognition memory and executive function were assessed starting 24 hours after anesthesia using the novel object recognition assay and the puzzle box, respectively. Data are expressed as mean (or median) differences (95% confidence interval). RESULTS: LPS induced neuroinflammation, as indicated by elevated levels of proinflammatory cytokines, including interleukin-1ß (LPS versus control, hippocampus: 3.49 pg/mg [2.06-4.92], P < .001; cortex: 2.60 pg/mg [0.83-4.40], P = .010) and tumor necrosis factor-α (hippocampus: 3.50 pg/mg [0.83-11.82], P = .002; cortex: 2.38 pg/mg [0.44-4.31], P = .021). Recognition memory was impaired in mice treated with LPS, as evinced by a lack of preference for the novel object (novel versus familiar: 1.03 seconds [-1.25 to 3.30], P = .689), but not in mice treated with etomidate alone (novel versus familiar: 2.38 seconds [0.15-4.60], P = .031). Mice cotreated with both LPS and etomidate also exhibited memory deficits (novel versus familiar: 1.40 seconds [-0.83 to 3.62], P = .383). In the puzzle box, mice treated with either LPS or etomidate alone showed no deficits. However, the combination of LPS and etomidate caused deficits in problem-solving tasks (door open task: -0.21 seconds [-0.40 to -0.01], P = .037; plug task: -0.30 seconds [-0.50 to -0.10], P < .001; log values versus control), indicating impaired executive function. CONCLUSIONS: Impairments in recognition memory were driven by inflammation. Deficits in executive function were only observed in mice cotreated with LPS and etomidate. Thus, an interplay between inflammation and etomidate anesthesia led to cognitive deficits that were not observed with either factor alone. These findings suggest that inflammation and anesthetic drugs may interact synergistically, or their combination may unmask covert or latent deficits induced by each factor alone, leading to PNDs.

Inhibition of a tonic inhibitory conductance in mouse hippocampal neurones by negative allosteric modulators of α5 subunit-containing γ-aminobutyric acid type A receptors: implications for treating cognitive deficits.

BACKGROUND: Multiple cognitive and psychiatric disorders are associated with an increased tonic inhibitory conductance that is generated by α5 subunit-containing γ-aminobutyric acid type A (α5 GABAA) receptors. Negative allosteric modulators that inhibit α5 GABAA receptors (α5-NAMs) are being developed as treatments for these disorders. The effects of α5-NAMs have been studied on recombinant GABAA receptors expressed in non-neuronal cells; however, no study has compared drug effects on the tonic conductance generated by native GABAA receptors in neurones, which was the goal of this study. METHODS: The effects of five α5-NAMs (basmisanil, Ono-160, L-655,708, α5IA, and MRK-016) on tonic current evoked by a low concentration of GABA were studied using whole-cell recordings in cultured mouse hippocampal neurones. Drug effects on current evoked by a saturating concentration of GABA and on miniature inhibitory postsynaptic currents (mIPSCs) were also examined. RESULTS: The α5-NAMs caused a concentration-dependent decrease in tonic current. The potencies varied as the inhibitory concentration for 50% inhibition (IC50) of basmisanil (127 nM) was significantly higher than those of the other compounds (0.4-0.8 nM). In contrast, the maximal efficacies of the drugs were similar (35.5-51.3% inhibition). The α5-NAMs did not modify current evoked by a saturating GABA concentration or mIPSCs. CONCLUSIONS: Basmisanil was markedly less potent than the other α5-NAMs, an unexpected result based on studies of recombinant α5 GABAA receptors. Studying the effects of α5 GABAA receptor-selective drugs on the tonic inhibitory current in neurones could inform the selection of compounds for future clinical trials.

Inhibiting α5 Subunit-Containing γ-Aminobutyric Acid Type A Receptors Attenuates Cognitive Deficits After Traumatic Brain Injury.

OBJECTIVES: Cognitive deficits after traumatic brain injury are a leading cause of disability worldwide, yet no effective pharmacologic treatments exist to improve cognition. Traumatic brain injury increases proinflammatory cytokines, which trigger excess function of α5 subunit-containing γ-aminobutyric acid type A receptors. In several models of brain injury, drugs that inhibit α5 subunit-containing γ-aminobutyric acid type A receptor function improve cognitive performance. Thus, we postulated that inhibiting α5 subunit-containing γ-aminobutyric acid type A receptors would improve cognitive performance after traumatic brain injury. In addition, because traumatic brain injury reduces long-term potentiation in the hippocampus, a cellular correlate of memory, we studied whether inhibition of α5 subunit-containing γ-aminobutyric acid type A receptors attenuated deficits in long-term potentiation after traumatic brain injury. DESIGN: Experimental animal study. SETTING: Research laboratory. SUBJECTS: Adult male mice and hippocampal brain slices. INTERVENTIONS: Anesthetized mice were subjected to traumatic brain injury with a closed-head, free-weight drop method. One week later, the mice were treated with L-655,708 (0.5 mg/kg), an inhibitor that is selective for α5 subunit-containing γ-aminobutyric acid type A receptors, 30 minutes before undergoing behavioral testing. Problem-solving abilities were assessed using the puzzle box assay, and memory performance was studied with novel object recognition and object place recognition assays. In addition, hippocampal slices were prepared 1 week after traumatic brain injury, and long-term potentiation was studied using field recordings in the cornu Ammonis 1 region of slices that were perfused with L-655,708 (100 nM). MEASUREMENTS AND MAIN RESULTS: Traumatic brain injury increased the time required to solve difficult but not simple tasks in the puzzle box assay and impaired memory in the novel object recognition and object place recognition assays. L-655,708 improved both problem solving and memory in the traumatic brain injury mice. Traumatic brain injury reduced long-term potentiation in the hippocampal slices, and L-655,708 attenuated this reduction. CONCLUSIONS: Pharmacologic inhibition of α5 subunit-containing γ-aminobutyric acid type A receptors attenuated cognitive deficits after traumatic brain injury and enhanced synaptic plasticity in hippocampal slices. Collectively, these results suggest that α5 subunit-containing γ-aminobutyric acid type A receptors are novel targets for pharmacologic treatment of traumatic brain injury-induced persistent cognitive deficits.

Reduced excitatory neurotransmission in the hippocampus after inflammation and sevoflurane anaesthesia.

Background: Inflammation and general anaesthesia likely contribute to perioperative neurocognitive disorders, possibly by causing a neuronal imbalance of excitation and inhibition. We showed previously that treatment with lipopolysaccharide (LPS) and sevoflurane causes a sustained increase in a tonic inhibitory conductance in the hippocampus; however, whether excitatory neurotransmission is also altered remains unknown. The goal of this study was to examine excitatory synaptic currents in the hippocampus after treatment with LPS and sevoflurane. Synaptic plasticity in the hippocampus, a cellular correlate of learning and memory, was also studied. Methods: Mice were injected with vehicle or LPS (1 mg kg-1 i.p.), and after 24 h they were then exposed to vehicle or sevoflurane (2.3%; 2 h). Hippocampal slices were prepared 48 h later. Excitatory synaptic currents were recorded from pyramidal neurones. Long-term potentiation (LTP) and long-term depression (LTD) were studied in the Schaffer collateral-cornu ammonis 1 pathway. Results: The amplitude of miniature excitatory postsynaptic currents (EPSCs) was reduced after LPS+sevoflurane (P<0.001), whereas that of spontaneous EPSCs was unaltered, as evidenced by cumulative distribution plots. The frequency, area, and kinetics of both miniature and spontaneous EPSCs were unchanged, as were LTP and LTD. Conclusions: The reduced amplitude of miniature EPSCs, coupled with the previously reported increase in tonic inhibition, indicates that the combination of LPS and sevoflurane markedly disrupts the balance of excitation and inhibition. Restoring this balance by pharmacologically enhancing excitatory neurotransmission and inhibiting the tonic current may represent an effective therapeutic option for perioperative neurocognitive disorders.

Cell-surface biotinylation of GABAA receptors in mouse hippocampal slices after sevoflurane anesthesia.

Here, we present a protocol for studying the cell-surface proteins in hippocampal slices after in vivo administration of sevoflurane, an inhaled general anesthetic drug, to mice. We describe steps for anesthetic delivery, hippocampal slice preparation, and cell-surface biotinylation. We then detail the isolation of surface proteins and their quantification through Western blotting. This protocol can be adapted to study changes in other surface proteins following exposure to various general anesthetic drugs. For complete details on the use and execution of this protocol, please refer to Wang et al. (2012),1 Zurek et al. (2014),2 and Yu et al. (2019).3.

GABAA Receptors in Astrocytes Are Targets for Commonly Used Intravenous and Inhalational General Anesthetic Drugs.

Background: Perioperative neurocognitive disorders (PNDs) occur commonly in older patients after anesthesia and surgery. Treating astrocytes with general anesthetic drugs stimulates the release of soluble factors that increase the cell-surface expression and function of GABAA receptors in neurons. Such crosstalk may contribute to PNDs; however, the receptor targets in astrocytes for anesthetic drugs have not been identified. GABAA receptors, which are the major targets of general anesthetic drugs in neurons, are also expressed in astrocytes, raising the possibility that these drugs act on GABAA receptors in astrocytes to trigger the release of soluble factors. To date, no study has directly examined the sensitivity of GABAA receptors in astrocytes to general anesthetic drugs that are frequently used in clinical practice. Thus, the goal of this study was to determine whether the function of GABAA receptors in astrocytes was modulated by the intravenous anesthetic etomidate and the inhaled anesthetic sevoflurane. Methods: Whole-cell voltage-clamp recordings were performed in astrocytes in the stratum radiatum of the CA1 region of hippocampal slices isolated from C57BL/6 male mice. Astrocytes were identified by their morphologic and electrophysiologic properties. Focal puff application of GABA (300 µM) was applied with a Picospritzer system to evoke GABA responses. Currents were studied before and during the application of the non-competitive GABAA receptor antagonist picrotoxin (0.5 mM), or etomidate (100 µM) or sevoflurane (532 µM). Results: GABA consistently evoked inward currents that were inhibited by picrotoxin. Etomidate increased the amplitude of the peak current by 35.0 ± 24.4% and prolonged the decay time by 27.2 ± 24.3% (n = 7, P < 0.05). Sevoflurane prolonged current decay by 28.3 ± 23.1% (n = 7, P < 0.05) but did not alter the peak amplitude. Etomidate and sevoflurane increased charge transfer (area) by 71.2 ± 45.9% and 51.8 ± 48.9% (n = 7, P < 0.05), respectively. Conclusion: The function of astrocytic GABAA receptors in the hippocampus was increased by etomidate and sevoflurane. Future studies will determine whether these general anesthetic drugs act on astrocytic GABAA receptors to stimulate the release of soluble factors that may contribute to PNDs.

Small molecule inhibitors of α-synuclein oligomers identified by targeting early dopamine-mediated motor impairment in C. elegans.

BACKGROUND: Parkinson's disease is a disabling neurodegenerative movement disorder characterized by dopaminergic neuron loss induced by α-synuclein oligomers. There is an urgent need for disease-modifying therapies for Parkinson's disease, but drug discovery is challenged by lack of in vivo models that recapitulate early stages of neurodegeneration. Invertebrate organisms, such as the nematode worm Caenorhabditis elegans, provide in vivo models of human disease processes that can be instrumental for initial pharmacological studies. METHODS: To identify early motor impairment of animals expressing α-synuclein in dopaminergic neurons, we first used a custom-built tracking microscope that captures locomotion of single C. elegans with high spatial and temporal resolution. Next, we devised a method for semi-automated and blinded quantification of motor impairment for a population of simultaneously recorded animals with multi-worm tracking and custom image processing. We then used genetic and pharmacological methods to define the features of early motor dysfunction of α-synuclein-expressing C. elegans. Finally, we applied the C. elegans model to a drug repurposing screen by combining it with an artificial intelligence platform and cell culture system to identify small molecules that inhibit α-synuclein oligomers. Screen hits were validated using in vitro and in vivo mammalian models. RESULTS: We found a previously undescribed motor phenotype in transgenic α-synuclein C. elegans that correlates with mutant or wild-type α-synuclein protein levels and results from dopaminergic neuron dysfunction, but precedes neuronal loss. Together with artificial intelligence-driven in silico and in vitro screening, this C. elegans model identified five compounds that reduced motor dysfunction induced by α-synuclein. Three of these compounds also decreased α-synuclein oligomers in mammalian neurons, including rifabutin which has not been previously investigated for Parkinson's disease. We found that treatment with rifabutin reduced nigrostriatal dopaminergic neurodegeneration due to α-synuclein in a rat model. CONCLUSIONS: We identified a C. elegans locomotor abnormality due to dopaminergic neuron dysfunction that models early α-synuclein-mediated neurodegeneration. Our innovative approach applying this in vivo model to a multi-step drug repurposing screen, with artificial intelligence-driven in silico and in vitro methods, resulted in the discovery of at least one drug that may be repurposed as a disease-modifying therapy for Parkinson's disease.

Evaluation the Effects of Eucalyptus Essential Oil and Hypertonic Saline as Scolicidal Agents in Induction of Sclerosing Cholangitis in Rabbits.

BACKGROUND: There are several scolicidal agents for inactivation of hydatid cyst protoscolices during surgery, but most of them are associated with adverse side effects such as sclerosing cholangitis (SC) and liver necrosis. The present study aimed to evaluate the adverse effects of Eucalyptus essential oil to induce SC in animal models. MATERIALS AND METHODS: Eighteen rabbits weighting 2000-3500 g were included in three groups for this study. About 0.3 ml of Eucalyptus essential oil (1%), or 5% hypertonic saline, or normal saline was injected for 5 min in the gallbladder. After 4 months, the liver, common bile duct, and duodenum were resected and immediately sent for cholangiography and pathologic studies. RESULTS: According to pathological studies, inflammation is more common in Eucalyptus and hypertonic saline groups. Due to cholangiographic studies, stricture was slightly higher in the hypertonic saline group than the Eucalyptus group. CONCLUSION: Thus, 1% Eucalyptus essential oil is at least as safe as 5% hypertonic saline, but for clinical uses, it must be confirmed with further studies.

Diagnosing Myocardial Contusion after Blunt Chest Trauma.

A myocardial contusion refers to a bruise of the cardiac muscle, the severity of which can vary depending on the severity of the injury and when the injury occurs. It is a major cause of rapid death which happens after blunt chest trauma and should be suspected at triage in the emergency department. We demonstrated that suspected myocardial contusion patients who have normal electrocardiograms (ECGs) and biomarker tests can be safely discharged. However, if the test results are abnormal, the next steps should be echocardiography and more advanced measures. Diagnosing myocardial contusion is very difficult because of its nonspecific symptoms. If a myocardial contusion happens, cardiogenic shock or arrhythmia must be anticipated, and the patient must be carefully monitored.

Outcome of Fecal Incontinence in Patients with Rectal Prolapse Undergoing the Altemeier Procedure with or without Posterior Levatorplasty / Desfecho de incontinência fecal em pacientes com prolapso retal submetidos ao procedimento de Altermeier com ou sem levatorplastia posterior

Abstract Objective To compare the fecal incontinence status of patients submitted to theAltemeier procedure with or without posterior levatorplasty. Materials and Methods Medical records of the patients who underwent the Altemeier procedure at Shahid Faghihi Hospital (in Shiraz, Iran) from 2014 to 2018 were retrospectively studied. Patients older than 17 years of age who underwent the Altemeier procedure due to complete rectal prolapse were considered. In some cases, the operation was performed with posterior levatorplasty. Rectal prolapse due to collagen or connective tissue disorders, anal/sacral anomalies, immunodeficiency, history of rectal surgery, and pelvic radiotherapy were the exclusion criteria of the present study. In addition to the demographics (including age, gender, and body mass index), the fecal incontinence status of each case was determined through theWexner scale preoperatively and 12 months after the surgery. The incontinence scores were then compared against the baseline values of the two groups of patients: those with and those without posterior levatorplasty. The statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS, IBM Corp., Armonk, NY, US), software, version 21. Results In total, 53 patients (17 men and 36 women) with a mean age of 55.23 ± 18.24 years were analyzed. The comparison of the pre- and postoperative scores on theWexner scale between the two groups revealed no statistically significant difference (p >0.05). Conclusion Posterior levatorplasty during the Altemeier procedure did not result in significant improvement of the fecal incontinence outcome of the patients.

Resumo Objetivo Comparar o status de incontinência fecal de pacientes após o procedimento de Altemeier com e sem levatorplastia posterior. Materiais e métodos Os prontuários médicos dos pacientes submetidos ao procedimento de Altemeier no Shahid Faghihi Hospital (em Shiraz, Irã) entre 2014 e 2018 foram avaliados retrospectivamente. Pacientes com idade superior a 17 anos submetidos ao procedimento de Altemeier devido a prolapso retal completo foram considerados. Em alguns casos, a operação foi realizada com levatorplastia posterior. Prolapso retal devido a distúrbios de colágeno ou do tecido conjuntivo, anomalias anais/sacrais, imunodeficiência, histórico de cirurgia retal, e radioterapia pélvica foram os critérios de exclusão deste estudo. Além dos dados demográficos (incluindo idade, sexo, e índice de massa corporal), o status da incontinência fecal de cada caso foi determinado por meio da escala de Wexner antes e doze meses após a cirurgia. Então, as pontuações de incontinência foram comparadas aos valores de referência dos dois grupos de pacientes: com e sem levatorplastia posterior. A análise estatística foi feita usandose o programa Statistical Package for the Social Sciences (SPSS, IBM Corp., Armonk, NY, EUA), versão 21. Resultados No total, 53 pacientes (17 homens e 36 mulheres) com idade média de 55.23 ± 18.24 anos foramavaliados. A comparação entre os grupos das pontuações na escala de Werner no pré e pós-operatório não revelou diferença estatisticamente significativa (p>0.05). Conclusão Levatorplastia superior durante o procedimento de Altemeier não resultou em melhora significativa do desfecho da incontinência fecal dos pacientes.

Acute Appendicitis as Complication of Colon Transit Time Study; A Case Report.

Colon transit time study with radio opaque markers is a simple method for assessment of colon motility disorder in patients with chronic idiopathic constipation. We report a case of acute appendicitis that was induced by impaction of radio opaque markers after colon transit time study. We think that this case report is first significant complication of colon transit time study until now.

Laparoscopic pelvic organ suspension with mesh: a modified technique and primary results / Suspensão laparoscópica de órgão pélvico com malha: uma técnica modificada e resultados primários

Abstract Background: Pelvic organ prolapse recurrence rate is an important issue which impacts the patient's quality of life and results in a new surgical procedure. We use a new technique of laparoscopic pelvic organ suspension (rectal suspension) for pelvic organ prolapse treatment in our center. We evaluated the results of this technique, three months after surgery and at the time of study reporting. Methods: All patients with pelvic organ prolapse for whom laparoscopic pelvic organ prolapse had been done were evaluated. Data were collected from the patient's charts and their short term follow up 3 months after the surgery and their last follow up visit. Demographic, history, physical examination, Wexner's fecal incontinence score and Altomare's Obstructed Defecation Syndrome score, post-operation complications and patient's satisfaction were analyzed, retrospectively. Results: All patients were female with a mean age of 57 ± 11.43 years (range 32-86 years). Mean BMI was 26.1 ± 3.73. Nine patients had rectal bleeding (31%), 18 had prolonged or difficult defecation (62%), 16 had rectal prolapse (55.2%), 11 had gas incontinence (37.9%), 9 had liquid stool incontinence (31%), 5 had stool incontinence (17.2%), 9 had vaginal prolapse (31%), 23 had constipation (79.3%), 9 complaint of pelvic pain (31%), 9 had urge or stress urinary incontinence (31%) and 13 had dyspareunia (44.8%). Conclusions: In conclusion, we believe this procedure has good results in short term follow up (3 months after surgery), but a high recurrence rate in the middle term follow up. Therefore, this procedure is no longer recommended.

Resumo Introdução: A taxa de recorrência do prolapso de órgãos pélvicos é uma questão importante que afeta a qualidade de vida do paciente, resultando em um novo procedimento cirúrgico. Os autores adotaram uma nova técnica de suspensão laparoscópica de órgãos pélvicos (suspensão retal) no tratamento de prolapso de órgãos pélvicos. Os resultados dessa técnica foram avaliados três meses após a cirurgia e no momento do relato do estudo. Métodos: Todos os pacientes com prolapso de órgão pélvico submetidos a suspensão laparoscópica foram avaliados. Os dados foram coletados do prontuário do paciente, na visita de acompanhamento três meses após a cirurgia e na última visita de acompanhamento. Os dados demográficos, histórico médico, avaliação física, escore de incontinência fecal de Wexner, escore da síndrome da defecação obstruída de Altomare, complicações pós-operatórias e satisfação do paciente foram analisados retrospectivamente. Resultados: Todos os pacientes eram do sexo feminino, com média de idade de 57 ± 11,43 anos (variação de 32 a 86 anos). O índice de massa corporal médio foi de 26,1 ± 3,73. Nove (31%) pacientes apresentaram sangramento retal; 18 (62%), defecação prolongada ou difícil; 16 (55,2%), prolapso retal; 11 (37,9%), incontinência gasosa; nove (31%), incontinência fecal líquida, cinco (17,2%), incontinência fecal; nove (31%), prolapso vaginal; 23 (79,3%), constipação; nove (31%), queixa de dor pélvica; nove (31%), incontinência urinária de urgência ou esforço e 13 (44,8%), dispareunia. Conclusões: Os autores acreditam que este procedimento apresenta bons resultados no seguimento de curto prazo (três meses após a cirurgia), mas uma alta taxa de recorrência no acompanhamento a médio prazo. Portanto, esse procedimento não é mais recomendado.