Patient and operative factors influence delayed discharge following bariatric surgery in an enhanced recovery setting.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) programs have been widely adopted in bariatric surgery. However, not all patients are successfully managed in the ERAS setting and there is currently little way of predicting the patients who will deviate from the program. Early identification of these patients could allow for more tailored protocols to be implemented preoperatively to address the issues, thereby improving patient outcomes. OBJECTIVES: The aim of this study was to elucidate the factors which preclude discharge by comparing patients who were successfully discharged by the end of the first postoperative day (POD 0/1) to those who stayed longer, including revisional surgery in this analysis. SETTING: A tertiary, high-volume Bariatric Centre, United Kingdom. METHODS: A retrospective analysis was performed of all patients undergoing bariatric surgery in a single centre in 1 year. Multivariate analyses compared patient and operative variables between patients who were discharged on POD 0/1 and those who stayed longer. RESULTS: A total of 288 bariatric operations were performed: 78% of operations performed were laparoscopic Roux-en-Y gastric bypass; 22% laparoscopic sleeve gastrectomy. Of these cases, 13% were revisional operations. Four patients returned to theatre on the index admission. 81% of patients were discharged by POD 0/1. A re-presentation within 30 days was seen in 6% of patients. There was no significant difference in length of stay for the type of operation performed (P = .86). Patients who had a revisional procedure were not more likely to stay longer. Length of stay was also independent of age, BMI, and comorbidities. Caucasian patients were more likely to be discharged on POD 0/1 than those of other ethnicities (90% versus 78%; P = .02). Operations performed by trainee surgeons, under consultant supervision, were significantly more likely to be discharged on POD 0/1 (P = .03). However, a logistic regression analysis was unable to predict patients who had a prolonged stay. CONCLUSIONS: Patient length of stay is independent of BMI, operation, and comorbidities and these factors do not need special consideration in ERAS pathways. Patients undergoing revisional procedures can be managed in the same way as those having primary procedures, with a routine POD 0/1 discharge. However, the impact of individual patient factors, and their interaction, is complex and cannot predict overstay.

[Hyperbaric oxygen therapy in outpatient care]. / A túlnyomásos oxigénkezelés és helye az ambuláns ellátásban.

Hyperbaric oxygen therapy, or high pressure oxygen therapy, is a highly specialised branch of medicine. Applications and results date back to the 1960s and it has been used, researched and developed ever since. During the treatment, patients breathe 100% oxygen in a pressurised chamber. For clinical purposes, as defined, the pressure must equal or exceed 1.4 atmosphera absolute, most of the cases typically higher (2.0-2.5 atmosphera absolute). Oxygen dissolves by pressure in body fluids, transported by circulation to all tissues. Cellular regeneration and tissue processes are induced by both the increased oxygen supply and the intermittent change in tissue partial oxygen pressure associated with treatment. The effect can be used in the treatment of many diseases, usually as part of a complex treatment plan. Additional advantage is that it is a non-invasive and pain-free therapy. Evidence-based indications and general baseline usage are regulated by the European Underwater and Baromedical Society through the European Committee of Hyperbaric Medicine, in accordance with the principles of evidence-based medicine. The authors describe three cases in their publication where hyperbaric oxygen therapy significantly contributed to the success of overall treatment. Orv Hetil. 2023; 164(25): 993-996.

Molecular Dissection of DAAM Function during Axon Growth in Drosophila Embryonic Neurons.

Axonal growth is mediated by coordinated changes of the actin and microtubule (MT) cytoskeleton. Ample evidence suggests that members of the formin protein family are involved in the coordination of these cytoskeletal rearrangements, but the molecular mechanisms of the formin-dependent actin-microtubule crosstalk remains largely elusive. Of the six Drosophila formins, DAAM was shown to play a pivotal role during axonal growth in all stages of nervous system development, while FRL was implicated in axonal development in the adult brain. Here, we aimed to investigate the potentially redundant function of these two formins, and we attempted to clarify which molecular activities are important for axonal growth. We used a combination of genetic analyses, cellular assays and biochemical approaches to demonstrate that the actin-processing activity of DAAM is indispensable for axonal growth in every developmental condition. In addition, we identified a novel MT-binding motif within the FH2 domain of DAAM, which is required for proper growth and guidance of the mushroom body axons, while being dispensable during embryonic axon development. Together, these data suggest that DAAM is the predominant formin during axonal growth in Drosophila, and highlight the contribution of multiple formin-mediated mechanisms in cytoskeleton coordination during axonal growth.

A Comparative Study of the Role of Formins in Drosophila Embryonic Dorsal Closure.

Dorsal closure is a late embryogenesis process required to seal the epidermal hole on the dorsal side of the Drosophila embryo. This process involves the coordination of several forces generated in the epidermal cell layer and in the amnioserosa cells, covering the hole. Ultimately, these forces arise due to cytoskeletal rearrangements that induce changes in cell shape and result in tissue movement. While a number of cytoskeleton regulatory proteins have already been linked to dorsal closure, here we expand this list by demonstrating that four of the six Drosophila formin type actin assembly factors are needed to bring about the proper fusion of the epithelia. An analysis of the morphological and dynamic properties of dorsal closure in formin mutants revealed a differential contribution for each formin, although we found evidence for functional redundancies as well. Therefore, we propose that the four formins promote the formation of several, and only partly identical, actin structures each with a specific role in the mechanics of dorsal closure.

Formin 3 directs dendritic architecture via microtubule regulation and is required for somatosensory nociceptive behavior.

Dendrite shape impacts functional connectivity and is mediated by organization and dynamics of cytoskeletal fibers. Identifying the molecular factors that regulate dendritic cytoskeletal architecture is therefore important in understanding the mechanistic links between cytoskeletal organization and neuronal function. We identified Formin 3 (Form3) as an essential regulator of cytoskeletal architecture in nociceptive sensory neurons in Drosophila larvae. Time course analyses reveal that Form3 is cell-autonomously required to promote dendritic arbor complexity. We show that form3 is required for the maintenance of a population of stable dendritic microtubules (MTs), and mutants exhibit defects in the localization of dendritic mitochondria, satellite Golgi, and the TRPA channel Painless. Form3 directly interacts with MTs via FH1-FH2 domains. Mutations in human inverted formin 2 (INF2; ortholog of form3) have been causally linked to Charcot-Marie-Tooth (CMT) disease. CMT sensory neuropathies lead to impaired peripheral sensitivity. Defects in form3 function in nociceptive neurons result in severe impairment of noxious heat-evoked behaviors. Expression of the INF2 FH1-FH2 domains partially recovers form3 defects in MTs and nocifensive behavior, suggesting conserved functions, thereby providing putative mechanistic insights into potential etiologies of CMT sensory neuropathies.

The Drosophila actin nucleator DAAM is essential for left-right asymmetry.

Left-Right (LR) asymmetry is essential for organ positioning, shape and function. Myosin 1D (Myo1D) has emerged as an evolutionary conserved chirality determinant in both Drosophila and vertebrates. However, the molecular interplay between Myo1D and the actin cytoskeleton underlying symmetry breaking remains poorly understood. To address this question, we performed a dual genetic screen to identify new cytoskeletal factors involved in LR asymmetry. We identified the conserved actin nucleator DAAM as an essential factor required for both dextral and sinistral development. In the absence of DAAM, organs lose their LR asymmetry, while its overexpression enhances Myo1D-induced de novo LR asymmetry. These results show that DAAM is a limiting, LR-specific actin nucleator connecting up Myo1D with a dedicated F-actin network important for symmetry breaking.

Nanoscopy reveals the layered organization of the sarcomeric H-zone and I-band complexes.

Sarcomeres are extremely highly ordered macromolecular assemblies where structural organization is intimately linked to their functionality as contractile units. Although the structural basis of actin and Myosin interaction is revealed at a quasiatomic resolution, much less is known about the molecular organization of the I-band and H-zone. We report the development of a powerful nanoscopic approach, combined with a structure-averaging algorithm, that allowed us to determine the position of 27 sarcomeric proteins in Drosophila melanogaster flight muscles with a quasimolecular, ∼5- to 10-nm localization precision. With this protein localization atlas and template-based protein structure modeling, we have assembled refined I-band and H-zone models with unparalleled scope and resolution. In addition, we found that actin regulatory proteins of the H-zone are organized into two distinct layers, suggesting that the major place of thin filament assembly is an M-line-centered narrow domain where short actin oligomers can form and subsequently anneal to the pointed end.

Drosophila Atg9 regulates the actin cytoskeleton via interactions with profilin and Ena.

Autophagy ensures the turnover of cytoplasm and requires the coordinated action of Atg proteins, some of which also have moonlighting functions in higher eukaryotes. Here we show that the transmembrane protein Atg9 is required for female fertility, and its loss leads to defects in actin cytoskeleton organization in the ovary and enhances filopodia formation in neurons in Drosophila. Atg9 localizes to the plasma membrane anchor points of actin cables and is also important for the integrity of the cortical actin network. Of note, such phenotypes are not seen in other Atg mutants, suggesting that these are independent of autophagy defects. Mechanistically, we identify the known actin regulators profilin and Ena/VASP as novel binding partners of Atg9 based on microscopy, biochemical, and genetic interactions. Accordingly, the localization of both profilin and Ena depends on Atg9. Taken together, our data identify a new and unexpected role for Atg9 in actin cytoskeleton regulation.

Toll and Toll-like receptor signalling in development.

The membrane receptor Toll and the related Toll-like receptors (TLRs) are best known for their universal function in innate immunity. However, Toll/TLRs were initially discovered in a developmental context, and recent studies have revealed that Toll/TLRs carry out previously unanticipated functions in development, regulating cell fate, cell number, neural circuit connectivity and synaptogenesis. Furthermore, knowledge of their molecular mechanisms of action is expanding and has highlighted that Toll/TLRs function beyond the canonical NF-κB pathway to regulate cell-to-cell communication and signalling at the synapse. Here, we provide an overview of Toll/TLR signalling and discuss how this signalling pathway regulates various aspects of development across species.

Microtubule organization in presynaptic boutons relies on the formin DAAM.

Regulation of the cytoskeleton is fundamental to the development and function of synaptic terminals, such as neuromuscular junctions. Despite the identification of numerous proteins that regulate synaptic actin and microtubule dynamics, the mechanisms of cytoskeletal control during terminal arbor formation have remained largely elusive. Here, we show that DAAM, a member of the formin family of cytoskeleton organizing factors, is an important presynaptic regulator of neuromuscular junction development in Drosophila We demonstrate that the actin filament assembly activity of DAAM plays a negligible role in terminal formation; rather, DAAM is necessary for synaptic microtubule organization. Genetic interaction studies consistently link DAAM with the Wg/Ank2/Futsch module of microtubule regulation and bouton formation. Finally, we provide evidence that DAAM is tightly associated with the synaptic active zone scaffold, and electrophysiological data point to a role in the modulation of synaptic vesicle release. Based on these results, we propose that DAAM is an important cytoskeletal effector element of the Wg/Ank2 pathway involved in the determination of basic synaptic structures, and, additionally, that DAAM may couple the active zone scaffold to the presynaptic cytoskeleton.

Kek-6: A truncated-Trk-like receptor for Drosophila neurotrophin 2 regulates structural synaptic plasticity.

Neurotrophism, structural plasticity, learning and long-term memory in mammals critically depend on neurotrophins binding Trk receptors to activate tyrosine kinase (TyrK) signaling, but Drosophila lacks full-length Trks, raising the question of how these processes occur in the fly. Paradoxically, truncated Trk isoforms lacking the TyrK predominate in the adult human brain, but whether they have neuronal functions independently of full-length Trks is unknown. Drosophila has TyrK-less Trk-family receptors, encoded by the kekkon (kek) genes, suggesting that evolutionarily conserved functions for this receptor class may exist. Here, we asked whether Keks function together with Drosophila neurotrophins (DNTs) at the larval glutamatergic neuromuscular junction (NMJ). We tested the eleven LRR and Ig-containing (LIG) proteins encoded in the Drosophila genome for expression in the central nervous system (CNS) and potential interaction with DNTs. Kek-6 is expressed in the CNS, interacts genetically with DNTs and can bind DNT2 in signaling assays and co-immunoprecipitations. Ligand binding is promiscuous, as Kek-6 can also bind DNT1, and Kek-2 and Kek-5 can also bind DNT2. In vivo, Kek-6 is found presynaptically in motoneurons, and DNT2 is produced by the muscle to function as a retrograde factor at the NMJ. Kek-6 and DNT2 regulate NMJ growth and synaptic structure. Evidence indicates that Kek-6 does not antagonise the alternative DNT2 receptor Toll-6. Instead, Kek-6 and Toll-6 interact physically, and together regulate structural synaptic plasticity and homeostasis. Using pull-down assays, we identified and validated CaMKII and VAP33A as intracellular partners of Kek-6, and show that they regulate NMJ growth and active zone formation downstream of DNT2 and Kek-6. The synaptic functions of Kek-6 could be evolutionarily conserved. This raises the intriguing possibility that a novel mechanism of structural synaptic plasticity involving truncated Trk-family receptors independently of TyrK signaling may also operate in the human brain.

The formin DAAM is required for coordination of the actin and microtubule cytoskeleton in axonal growth cones.

Directed axonal growth depends on correct coordination of the actin and microtubule cytoskeleton in the growth cone. However, despite the relatively large number of proteins implicated in actin-microtubule crosstalk, the mechanisms whereby actin polymerization is coupled to microtubule stabilization and advancement in the peripheral growth cone remained largely unclear. Here, we identified the formin Dishevelled-associated activator of morphogenesis (DAAM) as a novel factor playing a role in concerted regulation of actin and microtubule remodeling in Drosophilamelanogaster primary neurons. In vitro, DAAM binds to F-actin as well as to microtubules and has the ability to crosslink the two filament systems. Accordingly, DAAM associates with the neuronal cytoskeleton, and a significant fraction of DAAM accumulates at places where the actin filaments overlap with that of microtubules. Loss of DAAM affects growth cone and microtubule morphology, and several aspects of microtubule dynamics; and biochemical and cellular assays revealed a microtubule stabilization activity and binding to the microtubule tip protein EB1. Together, these data suggest that, besides operating as an actin assembly factor, DAAM is involved in linking actin remodeling in filopodia to microtubule stabilization during axonal growth.

The activities of the C-terminal regions of the formin protein disheveled-associated activator of morphogenesis (DAAM) in actin dynamics.

Disheveled-associated activator of morphogenesis (DAAM) is a diaphanous-related formin protein essential for the regulation of actin cytoskeleton dynamics in diverse biological processes. The conserved formin homology 1 and 2 (FH1-FH2) domains of DAAM catalyze actin nucleation and processively mediate filament elongation. These activities are indirectly regulated by the N- and C-terminal regions flanking the FH1-FH2 domains. Recently, the C-terminal diaphanous-autoregulatory domain (DAD) and the C terminus (CT) of formins have also been shown to regulate actin assembly by directly interacting with actin. Here, to better understand the biological activities of DAAM, we studied the role of DAD-CT regions of Drosophila DAAM in its interaction with actin with in vitro biochemical and in vivo genetic approaches. We found that the DAD-CT region binds actin in vitro and that its main actin-binding element is the CT region, which does not influence actin dynamics on its own. However, we also found that it can tune the nucleating activity and the filament end-interaction properties of DAAM in an FH2 domain-dependent manner. We also demonstrate that DAD-CT makes the FH2 domain more efficient in antagonizing with capping protein. Consistently, in vivo data suggested that the CT region contributes to DAAM-mediated filopodia formation and dynamics in primary neurons. In conclusion, our results demonstrate that the CT region of DAAM plays an important role in actin assembly regulation in a biological context.

Three-tier regulation of cell number plasticity by neurotrophins and Tolls in Drosophila.

Cell number plasticity is coupled to circuitry in the nervous system, adjusting cell mass to functional requirements. In mammals, this is achieved by neurotrophin (NT) ligands, which promote cell survival via their Trk and p75NTR receptors and cell death via p75NTR and Sortilin. Drosophila NTs (DNTs) bind Toll receptors instead to promote neuronal survival, but whether they can also regulate cell death is unknown. In this study, we show that DNTs and Tolls can switch from promoting cell survival to death in the central nervous system (CNS) via a three-tier mechanism. First, DNT cleavage patterns result in alternative signaling outcomes. Second, different Tolls can preferentially promote cell survival or death. Third, distinct adaptors downstream of Tolls can drive either apoptosis or cell survival. Toll-6 promotes cell survival via MyD88-NF-κB and cell death via Wek-Sarm-JNK. The distribution of adaptors changes in space and time and may segregate to distinct neural circuits. This novel mechanism for CNS cell plasticity may operate in wider contexts.

[Stereotactic radiosurgery of abdominal cancer metastases. Report on the first successful extracranial radiosurgical intervention in Hungary]. / Hasüregi daganatáttétek stereotaxiás sugárkezelése egy ülésben. Beszámoló az elso hazai, koponyán kívüli sugársebészeti beavatkozásról.

Due to the development and increasing effectiveness of novel cancer therapies, the role of local treatments in metastatic diseases have been increasing in the last decades. The aim of the authors was to present the first successful extracranial stereotactic radiosurgical intervention in Hungary. A 58-year-old male patient with gastric adenocarcinoma underwent surgery and adjuvant chemotherapy. Later, surgical removal of suprarenal gland metastases and first line chemotherapy were carried out. Four years after the first surgery a follow up computed tomographic scan revealed bifocal peritoneal metastases caudally from the edge of the liver and the left kidney with diameters of 2 cm in size. Definitive stereotactic body radiosurgery of 12 Gy single dose was performed using cone beam computed tomography image guidance and intensity modulated arc therapy with two pairs of arcs. The total duration of the procedure was only 25 min and early or late side effects were not observed. Follow up computed tomography scans performed 3 and 7 months after the intervention showed complete regression of the metastases. The authors conclude that stereotactic body radiosurgery can be a safe and effective alternative of metastasis surgery in case of slow growing oligo-metastases.

Toll-6 and Toll-7 function as neurotrophin receptors in the Drosophila melanogaster CNS.

Neurotrophin receptors corresponding to vertebrate Trk, p75(NTR) or Sortilin have not been identified in Drosophila, thus it is unknown how neurotrophism may be implemented in insects. Two Drosophila neurotrophins, DNT1 and DNT2, have nervous system functions, but their receptors are unknown. The Toll receptor superfamily has ancient evolutionary origins and a universal function in innate immunity. Here we show that Toll paralogs unrelated to the mammalian neurotrophin receptors function as neurotrophin receptors in fruit flies. Toll-6 and Toll-7 are expressed in the CNS throughout development and regulate locomotion, motor axon targeting and neuronal survival. DNT1 (also known as NT1 and spz2) and DNT2 (also known as NT2 and spz5) interact genetically with Toll-6 and Toll-7, and DNT1 and DNT2 bind to Toll-6 and Toll-7 promiscuously and are distributed in vivo in domains complementary to or overlapping with those of Toll-6 and Toll-7. We conclude that in fruit flies, Tolls are not only involved in development and immunity but also in neurotrophism, revealing an unforeseen relationship between the neurotrophin and Toll protein families.

Proteome-wide study of endoplasmic reticulum stress induced by thapsigargin in N2a neuroblastoma cells.

Disturbances in intraluminal endoplasmic reticulum (ER) Ca(2+) concentration leads to the accumulation of unfolded proteins and perturbation of intracellular Ca(2+) homeostasis, which has a huge impact on mitochondrial functioning under normal and stress conditions and can trigger cell death. Thapsigargin (TG) is widely used to model cellular ER stress as it is a selective and powerful inhibitor of sarcoplasmic/endoplasmic reticulum Ca(2+) ATPases. Here we provide a representative proteome-wide picture of ER stress induced by TG in N2a neuroblastoma cells. Our proteomics study revealed numerous significant protein expression changes in TG-treated N2a cell lysates analysed by two-dimensional electrophoresis followed by mass spectrometric protein identification. The proteomic signature supports the evidence of increased bioenergetic activity of mitochondria as several mitochondrial enzymes with roles in ATP-production, tricarboxylic acid cycle and other mitochondrial metabolic processes were upregulated. In addition, the upregulation of the main ER resident proteins confirmed the onset of ER stress during TG treatment. It has become widely accepted that metabolic activity of mitochondria is induced in the early phases in ER stress, which can trigger mitochondrial collapse and subsequent cell death. Further investigations of this cellular stress response in different neuronal model systems like N2a cells could help to elucidate several neurodegenerative disorders in which ER stress is implicated.

Intraneuronal ß-amyloid and its interactions with proteins and subcellular organelles.

Amyloidogenic aggregation and misfolding of proteins are linked to neurodegeneration. The mechanism of neurodegeneration in Alzheimer's disease, which gives rise to severe neuronal death and memory loss, is not yet fully understood. The amyloid hypothesis remains the most accepted theory for the pathomechanism of the disease. It was suggested that ß-amyloid accumulation may play a key role in initiating the neurodegenerative processes. The recent intracellular ß-amyloid (iAß) hypothesis emphasizes the primary role of iAß to initiate the disease by interaction with cytoplasmic proteins and cell organelles, thereby triggering apoptosis. Sophisticated methods (proteomics, protein microarray, and super resolution microscopy) have been used for studying iAß interactions with proteins and membraneous structures. The present review summarizes the studies on the origin of iAß and the base of its neurotoxicity: interactions with cytosolic proteins and several cell organelles such as endoplasmic reticulum, endosomes, lysosomes, ribosomes, mitochondria, and the microtubular system.

Proteomic study of the toxic effect of oligomeric Aß1-42 in situ prepared from 'iso-Aß1-42'.

Alzheimer's disease (AD) is the most prevalent form of neurodegenerative disorders even so the exact pathomechanism is still unclear. Recently, it is widely accepted that amyloid-beta peptide (Aß) toxicity is positively linked to Aß oligomers, which may be responsible for the initiation of AD. For this reason, AD research requires well defined aggregation state and structure of Aß. Precursor peptide 'iso-Aß1-42' makes it possible to use Aß1-42 with well- defined aggregation state for in vitro and in vivo experiments. The aim of this study was to identify protein expression changes from differentiated SH-SY5Y neuroblastoma cells after treatment with oligomeric Aß1-42 prepared in situ from 'iso-Aß1-42'. In our experiment, a cell viability assay revealed a strong and time-dependent toxic effect of oligomeric Aß1-42 which was supported by dramatic morphological changes. Our proteomics study also revealed numerous significant protein expression changes (22 proteins down- and 25 proteins up-regulated) after comparison of the untreated and Aß1-42-treated cell lysates by two-dimensional electrophoresis. From the functional classification of the identified proteins, we found deregulations of proteins involved in metabolic processes, cytoskeleton organisation and protein biosynthesis and a huge number of up-regulated stress proteins displayed oligomeric Aß1-42-induced cell stress.