Investigation of the Entry Pathway and Molecular Nature of σ1 Receptor Ligands

The σ1 receptor (σ1-R) is an enigmatic endoplasmic reticulum resident transmembrane protein implicated in a variety of central nervous system disorders and whose agonists have neuroprotective activity. In spite of σ1-R’s physio-pathological and pharmacological importance, two of the most important features required to fully understand σ1-R function, namely the receptor endogenous ligand(s) and the molecular mechanism of ligand access to the binding site, have not yet been unequivocally determined. In this work, we performed molecular dynamics (MD) simulations to help clarify the potential route of access of ligand(s) to the σ1-R binding site, on which discordant results had been reported in the literature. Further, we combined computational and experimental procedures (i.e., virtual screening (VS), electron density map fitting and fluorescence titration experiments) to provide indications about the nature of σ1-R endogenous ligand(s). Our MD simulations on human σ1-R suggested that ligands access the binding site through a cavity that opens on the protein surface in contact with the membrane, in agreement with previous experimental studies on σ1-R from Xenopus laevis. Additionally, steroids were found to be among the preferred σ1-R ligands predicted by VS, and 16,17-didehydroprogesterone was shown by fluorescence titration to bind human σ1-R, with significantly higher affinity than the prototypic σ1-R ligand pridopidine in the same essay. These results support the hypothesis that steroids are among the most important physiological σ1-R ligands.

Arabidopsis thaliana sirtuins control proliferation and glutamate dehydrogenase activity

Sirtuins are part of a gene family of NAD-dependent deacylases that act on histone and non-histone proteins and control a variety of activities in all living organisms. Their roles are mainly related to energy metabolism and include lifetime regulation, DNA repair, stress resistance, and proliferation. A large amount of knowledge concerning animal sirtuins is available, but data about their plant counterparts are scarce. Plants possess few sirtuins that have, like in animals, a recognized role in stress defense and metabolism regulation. However, engagement in proliferation control, which has been demonstrated for mammalian sirtuins, has not been reported for plant sirtuins so far. In this work, srt1 and srt2 Arabidopsis mutant seedlings have been used to evaluate in vivo the role of sirtuins in cell proliferation and regulation of glutamate dehydrogenase, an enzyme demonstrated to be involved in the control of cell cycle in SIRT4-defective human cells. Moreover, bioinformatic analyses have been performed to elucidate sequence, structure, and function relationships between Arabidopsis sirtuins and between each of them and the closest mammalian homolog. We found that cell proliferation and GDH activity are higher in mutant seedlings, suggesting that both sirtuins exert a physiological inhibitory role in these processes. In addition, mutant seedlings show plant growth and root system improvement, in line with metabolic data. Our data also indicate that utilization of an easy to manipulate organism, such as Arabidopsis plant, can help to shed light on the molecular mechanisms underlying the function of genes present in interkingdom species.

Not just a matter of weight: A case report of ECMO treatment in a severely obese patient

The ELSO Guidelines list a BMI ≥ 40 kg/m² among the relative contraindications to give ECMO treatment in SARS – COV2 patients. We describe a case of a 52-year-old with BMI 50.21 kg/m², admitted to the intensive care unit (ICU) with severe respiratory conditions and successfully treated with extracorporeal membrane oxygenation (ECMO). The application of veno-venous (VV) ECMO will evolve as far as we understand the pathophysiology of the COVID-19 disease and will probably have a determinant role in management of patient with refractory hypoxemia, whose ventilation management is difficult, even in case of severe obesity.

Arabidopsis N-acetyltransferase activity 2 preferentially acetylates 1,3-diaminopropane and thialysine

Polyamine acetylation has an important regulatory role in polyamine metabolism. It is catalysed by GCN5-related N-acetyltransferases, which transfer acetyl groups from acetyl-coenzyme A to the primary amino groups of spermidine, spermine (Spm), or other polyamines and diamines, as was shown for the human Spermidine/Spermine N¹-acetyltransferase 1 (HsSSAT1). SSAT homologues specific for thialysine, a cysteine-derived lysine analogue, were also identified (e.g., HsSSAT2). Two HsSSAT1 homologues are present in Arabidopsis, namely N-acetyltransferase activity (AtNATA) 1 and 2. AtNATA1 was previously shown to be specific for 1,3-diaminopropane, ornithine, putrescine and thialysine, rather than Spm and spermidine. In the present study, in an attempt to find a plant Spm-specific SSAT, AtNATA2 was expressed in a heterologous bacterial system and catalytic properties of the recombinant protein were determined. Data indicate that recombinant AtNATA2 preferentially acetylates 1,3-diaminopropane and thialysine, throwing further light on AtNATA1 substrate specificity. Structural analyses evidenced that the preference of AtNATA1, AtNATA2 and HsSSAT2 for short amine substrates can be ascribed to different main-chain conformation or substitution of HsSSAT1 residues interacting with Spm distal regions. Moreover, gene expression studies evidenced that AtNATA1 gene, but not AtNATA2, is up-regulated by cytokinins, thermospermine and Spm, suggesting the existence of a link between AtNATAs and N¹-acetyl-Spm metabolism. This study provides insights into polyamine metabolism and structural determinants of substrate specificity of non Spm-specific SSAT homologues.

Impact of the pericapsular nerve group (PENG) block on postoperative analgesia and functional recovery following total hip arthroplasty: a randomised, observer-masked, controlled trial

The pericapsular nerve group (PENG) block is a novel regional anaesthesia technique that aims to provide hip analgesia with preservation of motor function, although evidence is currently lacking. In this single-centre, observer-masked, randomised controlled trial, patients undergoing total hip arthroplasty received pericapsular nerve group block or no block (control group). Primary outcome measure was maximum pain scores (0-10 numeric rating scale) measured in the first 48 h after surgery. Secondary outcomes included postoperative opioid consumption; patient mobilisation assessments; and length of hospital stay. Sixty patients were randomly allocated equally between groups. The maximum pain score of patients receiving the pericapsular nerve group block was significantly lower than in the control group at all time-points, with a median (IQR [range]) of 2.5 (2.0-3.7 [0-7]) vs. 5.5 (5.0-7.0 [2-8]) at 12 h; 3 (2.0-4.0 [0-7]) vs. 6 (5.0-6.0 [2-8]) at 24 h; and 2.0 (2.0-4.0 [0-5]) vs. 3.0 (2.0-4.7 [0-6]) at 48 h; all p < 0.001. Moreover, the pericapsular nerve group showed a significant reduction in opioid consumption, better range of hip motion and shorter time to ambulation. Although no significant difference in hospital length of stay was detected, our results suggest improved postoperative functional recovery following total hip arthroplasty in patients who received pericapsular nerve group block.

Genome-Wide Identification and Bioinformatics Characterization of Superoxide Dismutases in the Desiccation-Tolerant Cyanobacterium Chroococcidiopsis sp. CCMEE 029

A genome-wide investigation of the anhydrobiotic cyanobacterium Chroococcidiopsis sp. CCMEE 029 identified three genes coding superoxide dismutases (SODs) annotated as MnSODs (SodA2.1 and SodA2.2) and Cu/ZnSOD (SodC) as suggested by the presence of metal-binding motifs and conserved sequences. Structural bioinformatics analysis of the retrieved sequences yielded modeled MnSODs and Cu/ZnSOD structures that were fully compatible with their functional role. A signal-peptide bioinformatics prediction identified a Tat signal peptide at the N-terminus of the SodA2.1 that highlighted its transport across the thylakoid/cytoplasmic membranes and release in the periplasm/thylakoid lumen. Homologs of the Tat transport system were identified in Chroococcidiopsis sp. CCMEE 029, and the molecular docking simulation confirmed the interaction between the signal peptide of the SodA2.1 and the modeled TatC receptor, thus supporting the SodA2.1 translocation across the thylakoid/cytoplasmic membranes. No signal peptide was predicted for the MnSOD (SodA2.2) and Cu/ZnSOD, thus suggesting their occurrence as cytoplasmic proteins. No FeSOD homologs were identified in Chroococcidiopsis sp. CCMEE 029, a feature that might contribute to its desiccation tolerance since iron produces hydroxyl radical via the Fenton reaction. The overall-overexpression in response to desiccation of the three identified SOD-coding genes highlighted the role of SODs in the antioxidant enzymatic defense of this anhydrobiotic cyanobacterium. The periplasmic MnSOD protected the cell envelope against oxidative damage, the MnSOD localized in the thylakoid lumen scavengered superoxide anion radical produced during the photosynthesis, while the cytoplasmic MnSOD and Cu/ZnSOD reinforced the defense against reactive oxygen species generated at the onset of desiccation. Results contribute to decipher the desiccation-tolerance mechanisms of this cyanobacterium and allow the investigation of its oxidative stress response during future space experiments in low Earth orbit and beyond.

Known Drugs Identified by Structure-Based Virtual Screening Are Able to Bind Sigma-1 Receptor and Increase Growth of Huntington Disease Patient-Derived Cells

Huntington disease (HD) is a devastating and presently untreatable neurodegenerative disease characterized by progressively disabling motor and mental manifestations. The sigma-1 receptor (σ1R) is a protein expressed in the central nervous system, whose 3D structure has been recently determined by X-ray crystallography and whose agonists have been shown to have neuroprotective activity in neurodegenerative diseases. To identify therapeutic agents against HD, we have implemented a drug repositioning strategy consisting of: (i) Prediction of the ability of the FDA-approved drugs publicly available through the ZINC database to interact with σ1R by virtual screening, followed by computational docking and visual examination of the 20 highest scoring drugs; and (ii) Assessment of the ability of the six drugs selected by computational analyses to directly bind purified σ1R in vitro by Surface Plasmon Resonance and improve the growth of fibroblasts obtained from HD patients, which is significantly impaired with respect to control cells. All six of the selected drugs proved able to directly bind purified σ1R in vitro and improve the growth of HD cells from both or one HD patient. These results support the validity of the drug repositioning procedure implemented herein for the identification of new therapeutic tools against HD.

Bioinformatics analysis of Ras homologue enriched in the striatum, a potential target for Huntington's disease therapy

Huntington's disease (HD) is a lethal neurodegenerative disorder for which no cure is available yet. It is caused by abnormal expansion of a CAG triplet in the gene encoding the huntingtin protein (Htt), with consequent expansion of a polyglutamine repeat in mutated Htt (mHtt). This makes mHtt highly unstable and aggregation prone. Soluble mHtt is linked to cytotoxicity and neurotoxicity, whereas mHtt aggregates are thought to be neuroprotective. While Htt and mHtt are ubiquitously expressed throughout the brain and peripheral tissues, HD is characterized by selective degradation of the corpus striatum, without notable alterations in peripheral tissues. Screening for mRNAs preferentially expressed in rodent striatum led to the discovery of a GTP binding protein homologous to Ras family members. Due to these features, the newly discovered protein was termed Ras Homolog Enriched in Striatum (RHES). The aetiological role of RHES in HD has been ascribed to its small ubiquitin-like modifier (SUMO)-E3 ligase function. RHES sumoylates mHtt with higher efficiency than wild-type Htt, thereby protecting mHtt from degradation and increasing the amounts of the soluble form. Although RHES is an attractive target for HD treatment, essential information about protein structure and function are still missing. With the aim of investigating RHES 3D structure and function, bioinformatic analyses and molecular modelling have been performed in the present study, based on which, RHES regions predicted to be involved in the interaction with mHtt or the SUMO-E2 ligase Ubc9 have been identified. These regions have been used to design peptides aimed at inhibiting RHES interactions and, therefore, mHtt sumoylation; in turn, these peptides will be used to develop small molecule inhibitors by both rational design and virtual screening of large compound libraries. Once identified, RHES sumoylation inhibitors may open the road to the development of therapeutic agents against the severe, and currently untreatable, HD.

D.M.R. ("Double Reasoned Maturing"): innovative technique of agronomic ecologic control of grey mould on grapevine. trials and various considerations

A study was carried out in order to identify agronomic ecologic solutions in the indirect grey mould control on grapevine. These specific trials started since 1990 and, after years of validation, now they are applied by the entrepreneur to the business practice in the different pedological and climatic area and on different cultivars and forms of growing. The technique of "Doppia Maturazione Ragionata" (D.M.R.) ("Doubles Reasoned Maturing") consists of far "completing" the maturing of the grape for wilting on the plant through the reasoned cut of the heads to fruit e/o of shoots. The application of D.M.R., besides determining valid and important technical and qualitative (organoleptic, economic and social quality) improvements on the product, is particularly effective in the indirect grey mould control on grapevine. Such technique, in fact, allows us to vintage the grape during the business demands and not when imposed by Botrytis cinerea; it has been possible, in some cases, to vintage in December and over, without problems of B. cinerea. The trials have shown the technical, economic, social sustainability of D.M.R. application. This paper reports all trials that have brought, by now from years, to apply in the practice DMR (Double Reasoned Maturing).

"Minimum pruning", "minimal pruning" and "physiological pruning" as new techniques in grey mould agronomic eco-compatible (natural) control. Researches and considerations

The aim of this work was to find agronomic eco-compatible ("natural") control solutions against grey mould of grapevine too. Our researches about "minimum pruning", "minimal pruning" and "physiological pruning" started in 1980, and in 1983 with specific relation to grey mould on vines of Merlot, Cabernet sauvignon and Chardonnay previously set in vegetative and productive growth balance. These researches were conducted to verify the affordability of innovative winter pruning techniques like "minimum pruning", "minimal pruning" and the so called 'physiological pruning", in the natural agronomic eco-compatible grey mould control. As a result we found that the new techniques contribute to limit the incidence of grey mould; especially "physiological pruning" followed by "minimal pruning" and 'minimum pruning". The best results were observed on Chardonnay, followed by Merlot and Cabernet sauvignon.

[Hemorrhoidectomy with ropivacaine (Naropin) local anesthesia. Preliminary experience]

BACKGROUND

The use of local anesthesia in non-septic anal surgery is now well established. Tolerance to local injection, duration of local effect and the risk of local or systemic complications still represent unsolved issues. Ropivacaine, a new local anesthetic, seems particularly indicated for this kind of surgery because of its pharmacologic properties which reduce patient's discomfort during infiltration and provide good antalgic coverage in the first hours following the operation.

METHODS

The first 20 consecutive cases operated with local anesthesia by ropivacaine have been prospectively studied. All patients have been given an 11-point box VAS scale which is used for subjective evaluation of pain.

RESULTS

Mean pain score resulted 1.1, 1.6 and 1.4 at 1, 2 and 3 postoperative hours, respectively. Thirty percent of patients subsequently required pain medication up to the first bowel movement. No complications related to the use of ropivacaine has been observed.

CONCLUSIONS

This new drug can be safely used in the outpatient or Day-Surgery treatment of hemorrhoids.

[A case of loco-regional recurrence of carcinoma of the male breast]

The case of a 47-year-old man surgically treated with Halsted mastectomy for breast cancer and submitted to Tamoxifen therapy for more than four years is reported. A loco-regional recurrence following withdrawal of oestrogen antagonist therapy was observed and surgically treated by local excision. Normal karyotype analysis of peripheral leucocytes, normal male phenotype of the patient, his height and the lack of family history for breast cancer, as well as a possible dysfunction of the endocrine system were considered in the aetiopathogenesis of the disease.

[A case of anaplastic carcinoma of the thyroid. Clinico-pathological and therapeutic aspects and review of the literature]

A case of anaplastic carcinoma of the thyroid observed in a 72-year-old female patient, admitted with previous diagnosis of Riedel's thyroiditis, is reported. Clinicopathologic features and management of this rare neoplasm are discussed and Literature is reviewed. Anaplastic cancer is a locally and systemically aggressive histologic type, occurring more frequently in older patients and in those with a history of benign and/or malignant thyroid disease. Because long-term survival was seen most commonly in well-localized anaplastic tumors, a more aggressive approach to thyroid lesions, especially in the elderly, may be warranted to improve early diagnosis and effectiveness of therapy of this nearly always lethal neoplasm. Although patients can rarely be cured, efforts should be made to control the disease locally by combined treatment including surgery and radiochemotherapy, which is found to be, at times, a national palliative therapeutic approach despite patient's advanced age.

[Use of human fibrin glue (Tissucol) in the treatment of recurrent fistulas]

In this study, the treatment of either primitive or secondary abdominal relapsed fistulas with Human Fibrin Glue (Tissucol) is reported. Twelve patients with different types of fistulas were treated in day hospital with the above mentioned procedure. Apart from two patients, the good percentage of success obtained in a short period of time is stressed. Results show that such a technique may be favourably adopted, nevertheless a correct first surgical procedure is recommended.

[Tietze's syndrome in the elderly: description of a case and review of the literature]

A case of Tietze's syndrome in a 62-year-old man and a critical up-to-date review of the literature are reported. Although the etiology of the disease is unknown, it has been suggested that recurrent microtrauma of the anterior chest wall may be implied in the development of characteristic degenerative changes involving single or multiple upper costochondral junction. The syndrome described by Tietze has been more commonly found in older people than previously reported and it seems to be no sex or side prevalence. Because of the benign nature of this disease and its excellent prognosis, the treatment is usually symptomatic. The accumulated data stress the importance of a thorough clinical investigation and the need to exclude severe and lifethreatening conditions in the elderly.

[The clinico-diagnostic and therapeutic considerations in carcinoma of the male breast]

Three cases of male breast cancer, observed during the last 10 years at the III Surgical Department of the University of Rome "La Sapienza", out of a total of 282 operations performed for mammary carcinoma are reported. In agreement to what reported in the literature the M/F ratio was 1:100. It is pointed out how male breast cancer compared to the female one, involves older subjects. Furthermore, since the disease in males reaches its most advanced stages quite rapidly a radical surgical treatment such as the traditional Halsted operation is mandatory. The prevalence of the histopathological form of invasive ductal carcinoma and the high frequency of intratumoral estradiol and progesterone receptors are confirmed. The latter in many cases allows for adjuvant hormonal therapy and represents, in association with polychemotherapy, a valid alternative to traditional endocrino-surgical therapy, both in terms of long term prognosis and quality of life.