A Systematic Review of Direct Outputs from the Cerebellum to the Brainstem and Diencephalon in Mammals

The cerebellum is involved in many motor, autonomic and cognitive functions, and new tasks that have a cerebellar contribution are discovered on a regular basis. Simultaneously, our insight into the functional compartmentalization of the cerebellum has markedly improved. Additionally, studies on cerebellar output pathways have seen a renaissance due to the development of viral tracing techniques. To create an overview of the current state of our understanding of cerebellar efferents, we undertook a systematic review of all studies on monosynaptic projections from the cerebellum to the brainstem and the diencephalon in mammals. This revealed that important projections from the cerebellum, to the motor nuclei, cerebral cortex, and basal ganglia, are predominantly di- or polysynaptic, rather than monosynaptic. Strikingly, most target areas receive cerebellar input from all three cerebellar nuclei, showing a convergence of cerebellar information at the output level. Overall, there appeared to be a large level of agreement between studies on different species as well as on the use of different types of neural tracers, making the emerging picture of the cerebellar output areas a solid one. Finally, we discuss how this cerebellar output network is affected by a range of diseases and syndromes, with also non-cerebellar diseases having impact on cerebellar output areas.

Expression profiling of extramedullary acute myeloid leukemia suggests involvement of epithelial-mesenchymal transition pathways

Extramedullary (EM) colonization is a rare complication of acute myeloid leukemia (AML), occurring in about 10% of patients, but the processes underlying tissue invasion are not entirely characterized. Through the application of RNAseq technology, we examined the transcriptome profile of 13 AMLs, 9 of whom presented an EM localization. Our analysis revealed significant deregulation within the extracellular matrix (ECM)-receptor interaction and focal-adhesion pathways, specifically in the EM sites. The transcription factor TWIST1, which is known to impact on cancer invasion by dysregulating epithelial-mesenchymal-transition (EMT) processes, was significantly upregulated in EM-AML. To test the functional impact of TWIST1 overexpression, we treated OCI-AML3s with TWIST1-siRNA or metformin, a drug known to inhibit tumor progression in cancer models. After 48 h, we showed downregulation of TWIST1, and of the EMT-related genes FN1 and SNAI2. This was associated with significant impairment of migration and invasion processes by Boyden chamber assays. Our study shed light on the molecular mechanisms associated with EM tissue invasion in AML, and on the ability of metformin to interfere with key players of this process. TWIST1 may configure as candidate marker of EM-AML progression, and inhibition of EMT-pathways may represent an innovative therapeutic intervention to prevent or treat this complication.

The integrated brain network that controls respiration

Respiration is a brain function on which our lives essentially depend. Control of respiration ensures that the frequency and depth of breathing adapt continuously to metabolic needs. In addition, the respiratory control network of the brain has to organize muscular synergies that integrate ventilation with posture and body movement. Finally, respiration is coupled to cardiovascular function and emotion. Here, we argue that the brain can handle this all by integrating a brainstem central pattern generator circuit in a larger network that also comprises the cerebellum. Although currently not generally recognized as a respiratory control center, the cerebellum is well known for its coordinating and modulating role in motor behavior, as well as for its role in the autonomic nervous system. In this review, we discuss the role of brain regions involved in the control of respiration, and their anatomical and functional interactions. We discuss how sensory feedback can result in adaptation of respiration, and how these mechanisms can be compromised by various neurological and psychological disorders. Finally, we demonstrate how the respiratory pattern generators are part of a larger and integrated network of respiratory brain regions.

Prevalence and features of delirium in older patients admitted to rehabilitation facilities: a multicenter study

BACKGROUND

Delirium is thought to be common across various settings of care; however, still little research has been conducted in rehabilitation.

AIM

We investigated the prevalence of delirium, its features and motor subtypes in older patients admitted to rehabilitation facilities during the three editions of the "Delirium Day project".

METHODS

We conducted a cross-sectional study in which 1237 older patients (age ≥ 65 years old) admitted to 50 Italian rehabilitation wards during the three editions of the "Delirium Day project" (2015 to 2017) were included. Delirium was evaluated through the 4AT and its motor subtype with the Delirium Motor Subtype Scale.

RESULTS

Delirium was detected in 226 patients (18%), and the most recurrent motor subtype was mixed (37%), followed by hypoactive (26%), hyperactive (21%) and non-motor one (16%). In a multivariate Poisson regression model with robust variance, factors associated with delirium were: disability in basic (PR 1.48, 95%CI: 1.17-1.9, p value 0.001) and instrumental activities of daily living (PR 1.58, 95%CI: 1.08-2.32, p value 0.018), dementia (PR 2.10, 95%CI: 1.62-2.73, p value < 0.0001), typical antipsychotics (PR 1.47, 95%CI: 1.10-1.95, p value 0.008), antidepressants other than selective serotonin reuptake inhibitors (PR 1.3, 95%CI: 1.02-1.66, p value 0.035), and physical restraints (PR 2.37, 95%CI: 1.68-3.36, p value < 0.0001).

CONCLUSION

This multicenter study reports that 2 out 10 patients admitted to rehabilitations had delirium on the index day. Mixed delirium was the most prevalent subtype. Delirium was associated with unmodifiable (dementia, disability) and modifiable (physical restraints, medications) factors. Identification of these factors should prompt specific interventions aimed to prevent or mitigate delirium.

The association between low skeletal muscle mass and delirium: results from the nationwide multi-centre Italian Delirium Day 2017

Introduction

Delirium and sarcopenia are common, although underdiagnosed, geriatric syndromes. Several pathological mechanisms can link delirium and low skeletal muscle mass, but few studies have investigated their association. We aimed to investigate (1) the association between delirium and low skeletal muscle mass and (2) the possible role of calf circumference mass in finding cases with delirium.

Methods

The analyses were conducted employing the cross-sectional “Delirium Day” initiative, on patient 65 years and older admitted to acute hospital medical wards, emergency departments, rehabilitation wards, nursing homes and hospices in Italy in 2017. Delirium was diagnosed as a 4 + score at the 4-AT scale. Low skeletal muscle mass was operationally defined as calf circumference ≤ 34 cm in males and ≤ 33 cm in females. Logistic regression models were used to investigate the association between low skeletal muscle mass and delirium. The discriminative ability of calf circumference was evaluated using non-parametric ROC analyses.

Results

A sample of 1675 patients was analyzed. In total, 73.6% of participants had low skeletal muscle mass and 24.1% exhibited delirium. Low skeletal muscle mass and delirium showed an independent association (OR: 1.50; 95% CI 1.09–2.08). In the subsample of patients without a diagnosis of dementia, the inclusion of calf circumference in a model based on age and sex significantly improved its discriminative accuracy [area under the curve (AUC) 0.69 vs 0.57, p < 0.001].

Discussion and conclusion

Low muscle mass is independently associated with delirium. In patients without a previous diagnosis of dementia, calf circumference may help to better identify those who develop delirium.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40520-021-01950-8.

Input and output organization of the mesodiencephalic junction for cerebro-cerebellar communication

Most studies investigating the impact of the cerebral cortex (CC) onto the cerebellum highlight the role of the pons, which provides the mossy fibers to the cerebellum. However, cerebro‐cerebellar communication may also be mediated by the nuclei of the mesodiencephalic junction (MDJ) that project to the inferior olive (IO), which in turn provides the climbing fibers to the molecular layer. Here, we uncover the precise topographic relations of the inputs and outputs of the MDJ using multiple, classical, and transneuronal tracing methods as well as analyses of mesoscale cortical injections from Allen Mouse Brain. We show that the caudal parts of the CC predominantly project to the principal olive via the rostral MDJ and that the rostral parts of the CC predominantly project to the rostral medial accessory olive via the caudal MDJ. Moreover, using triple viral tracing technology, we show that the cerebellar nuclei directly innervate the neurons in the MDJ that receive input from CC and project to the IO. By unraveling these topographic and prominent, mono‐ and disynaptic projections through the MDJ, this work establishes that cerebro‐cerebellar communication is not only mediated by the pontine mossy fiber system, but also by the climbing fiber system.

Case-matched Comparison of Postoperative Outcomes Following Surgery for Inflammatory Bowel Disease After Exposure to Vedolizumab vs Other Biologics

BACKGROUND AND AIM

The effects of vedolizumab [VEDO] exposure on perioperative outcomes following surgery for inflammatory bowel disease [IBD] remain controversial. The aim of our study was to compare postoperative morbidity of IBD surgery following treatment with VEDO vs other biologics or no biologics.

METHODS

An institutional review board-approved, prospectively collected database was queried to identify all patients undergoing abdominal surgery for IBD between August 2012 and May 2017. The impact of VEDO within 12 weeks preoperatively on postoperative morbidity was initially assessed with univariate and multivariable analyses on all patients. A case-matched analysis was then carried out comparing patients exposed to VEDO vs other biologic agents, based on gender, age ± 5 years, diagnosis, date of surgery ± 2 years, and surgical procedure.

RESULTS

Out of 980 patients, 141 received VEDO. The majority of patients [59%] underwent surgery involving end or diverting ostomy creation. The initial multivariate analysis conducted on all patients indicated that VEDO use was independently associated with increased overall morbidity [p <0.001], but not infectious morbidity [p = 0.30]. However, the case-matched comparison of 95 VEDO-treated patients vs 95 patients treated with adalimumab or infliximab did not indicate any difference in overall morbidity [p = 0.32], infectious complications [p = 0.15], or surgical site infections [p = 0.12].

CONCLUSIONS

In a study population having a high rate of surgery involving ostomy creation, the exposure to preoperative VEDO was not associated with an increased morbidity rate when compared with other biologics.

A novel technique for enterotomy closure in stapled laparoscopic intracorporeal anastomosis

AIM

The proximal edge of the enterotomy in a side-to-side anastomosis has been shown to be the site at highest risk of leakage. Several methods have been described to overcome this vulnerability. The technical challenge of intra-corporeal anastomosis (ICA) is to re-create angles between tissues and instruments, similar to those in an open anastomosis. The axis between the suture line and the needle driver is paramount and this angle should be < 45°.

METHOD

The crotch stitch of the enterotomy is difficult because of the narrow space between the loops and the depth of the anastomosis. The usual technique is suturing right-handed, 'out-in and in-out', colonic edge first to small bowel. The risk of suture misplacement (e.g. 'out-in/out-in' or 'out-out') is similar to open procedures but laparoscopically the second bite is challenging, due to the straight needle-driver. This may lead to asymmetrical closure of the corner resulting in a slightly larger angle on the bowel side and a potential postoperative leak/fistula. Rotating the small bowel loop to counterbalance this issue, risks tearing of the staple line. The rationale is that starting with a back-handed stitch and taking the small bowel edge first would allow the necessary acute angled bite to be achieved. Subsequently, mounting the needle right-handed for taking the colonic edge also allows achievement of an acute angled bite.

RESULTS

Our novel technique, named the 'back-handed, left-to-right stitch' technique, is intended to achieve symmetrical approximation of the ileal and colonic edges during laparoscopy, with an optimal closure of the deepest extremity of the enterotomy. Such a stitch, used in a series of 10 patients, may be useful to avoid leaving an opening within this angle and/or to avoid potential technical pitfalls when closing the deepest apex of the enterotomy.

CONCLUSION

This 'back-handed, left-to-right' stitch described here allows a properly angled closure of the proximal edge of the enterotomy and a safe approximation of the corner of the enterotomy in a side-to-side ICA.

Impact of omega-3 polyunsaturated fatty acids on vascular function and blood pressure: Relevance for cardiovascular outcomes

AIMS

To overview the effects of omega-3 polyunsaturated fatty acids (PUFA) on blood vessels and blood pressure (BP) and their relevance for cardiovascular prevention.

DATA SYNTHESIS

The importance of omega-3 PUFA for the cardiovascular system has come under the spotlight during the last decades. These fatty acids are present in variable amounts in cell membranes of mammal species, and their content affects a variety of cellular functions. Evidence obtained in animal and human studies suggests that omega-3 PUFA affect many steps of the atherosclerotic process. In blood vessels, omega-3 PUFA improve endothelial function; promote vasodilatation through relaxation of smooth muscle cells; exert antioxidant, anti-inflammatory, and antithrombotic actions; delay development of plaques and increase their stability; and decrease wall stiffening. Omega-3 PUFA might affect BP, and studies conducted with ambulatory monitoring suggest that supplementation with these fatty acids decreases the average 24-h BP levels. This effect on BP is related to the pretreatment membrane content of omega-3 PUFA, and this might explain some inconsistencies among intervention trials. Meta-analyses indicate that omega-3 PUFA have a mild but significant BP lowering effect. While encouraging results were initially obtained with the use of omega-3 PUFA supplements in secondary prevention trials, meta-analyses have not confirmed the ability of these fatty acids to decrease the risk of coronary heart and cerebrovascular disease.

CONCLUSIONS

Omega-3 PUFA are associated with significant improvement in vascular function and lowering of BP. However, the evidence currently supporting the role of these fatty acids in cardiovascular prevention is weak and needs further investigation.

Aldosterone and Left Ventricular Remodeling

Experimental and clinical evidence obtained in the last 2 decades clearly indicates that protracted exposure to inappropriately elevated aldosterone levels causes significant changes in left ventricular structure and function. Animal studies have demonstrated that aldosterone induces myocardial inflammatory changes and fibrosis in the presence of a high salt diet. Moreover, the effects of aldosterone on the heart have been investigated in different clinical conditions. These conditions include systolic and diastolic heart failure, essential hypertension, and primary aldosteronism that offers a unique clinical model to study the cardiac effects of excess aldosterone because these effects are isolated from those of the renin-angiotensin axis. A relatively clear picture is emerging from these studies with regard to aldosterone-related changes in left ventricular mass and geometry. Conversely, no direct effect of aldosterone on left ventricular diastolic function can be demonstrated and improvement of diastolic function obtained in some studies that have employed mineralocorticoid receptor blockers could result from left ventricular mass reduction. Animal experiments demonstrate that effects of aldosterone on the left ventricle require high salt intake to occur, but the evidence of this contribution of salt to aldosterone-induced cardiac changes in humans remains weaker and needs further research. The article reviews the results of clinical studies addressing the role of aldosterone in regulation of LV remodeling and diastolic function, and focuses on the possible relevance of salt intake.

Mineralocorticoid Receptor Antagonists and Clinical Outcomes in Primary Aldosteronism: As Good as Surgery?

Primary aldosteronism (PA) is detected with increasing frequency in hypertensive patients and is associated with excess cardiovascular, renal, and metabolic complications. For these reasons, appropriate choices for treatment of this endocrine condition are mandatory. Adrenalectomy is safely performed in PA patients when adrenal venous sampling (AVS) demonstrates lateralized aldosterone secretion. AVS, however, is a complex procedure and even among worldwide referral centers there are substantial discrepancies for interpretation of results. Also, in the majority of PA patients with lateralized aldosterone secretion, hypertension may persist after adrenalectomy requiring use of additional antihypertensive agents. Treatment with mineralocorticoid receptor antagonists (MRAs) is currently recommended for PA patients with bilateral adrenal disease, but these agents effectively decrease blood pressure also in patients with unilateral disease, although concern remains for possible sex-related side effects. Prospective studies indicate that MRAs have therapeutic values comparable to surgery in the long-term, inasmuch as they effectively correct metabolic abnormalities and subclinical organ damage and reduce the risk of cardiovascular events and renal disease progression. This article overviews the clinical outcomes obtained in patients with PA with use of MRAs.

Simple-sequence repeat markers of Cattleya coccinea (Orchidaceae), an endangered species of the Brazilian Atlantic Forest

Microsatellite markers were developed for the endangered Brazilian orchid species Cattleya coccinea to describe its genetic diversity and structure and to support conservation studies. Nine microsatellite loci were isolated and characterized using an enriched genomic library. All loci are polymorphic at least in the 2 populations sampled, except for loci Cac05 and Cac09 for the Petrópolis population. The mean number of alleles per locus was 8.8 between populations. The mean values of the observed and expected heterozygosities were 0.541 (ranging from 0 to 1) and 0.639 (ranging from 0 to 0.9), respectively. Cross-amplifications were performed in 7 additional Epidendroideae species, and at least 2 loci were successful in 3 additional Cattleya species, Epidendrum secundum, and Brasiliorchis gracilis. All markers described herein will be useful in further studies evaluating the genetic diversity, population dynamics, and conservation genetics of C. coccinea and related species.

Relationship of plasma renin with a prothrombotic state in hypertension: relevance for organ damage

BACKGROUND

Components of the renin-angiotensin-aldosterone system (RAAS) and a prothrombotic state are predictors of cardiovascular events in hypertensive patients. A relationship between the RAAS and the coagulation/fibrinolytic systems has been demonstrated, but its clinical relevance in hypertension is unclear. We investigated the relationships of the RAAS and the hemostatic system with hypertensive organ damage.

METHODS

Plasma components of the RAAS and parameters that directly assess the activation of coagulation and fibrinolysis were measured in 247 essential hypertensive patients in whom the extent of organ damage had been characterized at the cardiac, renal, and vascular level.

RESULTS

Positive association with increasing plasma renin activity (PRA) was demonstrated for plasma fibrinogen, D-dimer, and plasminogen activator inhibitor-1 (PAI-1) levels. PRA was directly correlated with plasma aldosterone, fibrinogen, d-dimer, and PAI-1. The relationship of PRA with fibrinogen and PAI-1 remained significant after correction for age, gender, duration of hypertension, and smoking status. Plasma aldosterone levels were directly correlated with fibrinogen, D-dimer, and PAI-1, whereas plasma angiotensin-converting enzyme was not related with any of the coagulation parameters. Elevated PRA, aldosterone, fibrinogen, D-dimer, prothrombin fragment 1+2, and PAI-1 levels were associated with clinical and/or instrumental evidence of hypertension-related cardiac and renal damage. Both fibrinogen and PAI-1 were independent predictors of the presence of organ damage and their inclusion in a multivariate model eliminated PRA and aldosterone as independent predictors.

CONCLUSIONS

A strong and independent association exists between renin, aldosterone, and markers of a prothrombotic state in essential hypertension. This relationship might contribute to the development of hypertensive organ damage.