Aptamer-, heparin- or cocktail-based inhibition of S1-ACE2 protein complexes.

The Spike protein (S1) from the Severe acute respiratory syndrome 2 virus binds to angiotensin converting enzyme 2 (ACE2) receptor to initiate infection. Hence, antiviral therapeutic targeting the S1-ACE2 interface is of interest. Herein, we compare the inhibition efficacy of an aptamer to heparin or their cocktail, against wild-type (WT), Omicron, Delta, and Lambda S1-ACE2 complexes. The aptamer-protein complexes had the dissociation constant KD values in the 2-13 nM range. The aptamer half-maximal inhibitory concentration against WT S1-ACE was 17 nM, with the % inhibition in the 12-35% range. Several aptamer-S1 protein complexes were also stable at low pH with 60% inhibition. Despite the similarity in S1 sequences, the extent of inhibition (2-27%) with heparin was highly dependent on the type of S1 protein. More importantly, heparin did not inhibit the WT S1-ACE2 complex but was effective with mutants. The aptamer-heparin cocktail was less effective compared to aptamer or heparin, individually. Modelling data show that either a direct or proximal binding to RBD sites by aptamer or heparin prevents the ACE2 binding. Overall, heparin was as an effective inhibitor as aptamer against certain variants, and represents the more cost-effective neutralizing agent against emerging coronaviruses.

[Introduction to the hierarchical taxonomy of psychopathology]. / Introduction à la taxonomie hiérarchique de la psychopathologie.

INTRODUCTION: In clinical practice, the usefulness of diagnosis based on the Diagnostic or Statistical Manual of Mental Disorders (DSM) or the International Classification of Diseases, 11th edition, appears essential from a clinical, research, epidemiological, administrative, economic and political level. However, such diagnostic systems have shortcomings in terms of validity, little consideration of comorbidities and strong intra-class heterogeneity. On a structural level, the operationalization of its criteria is based on a reliability which has been defined a posteriori and which does not lead to improving the validity of the diagnosis but rather to the reification of the diagnostic categories. METHODS: First published in its current form in 2017, the Hierarchical Taxonomy of Psychopathology (HiTOP) constitutes a nosological alternative based on statistics. It conceptualizes psychopathology as a set of hierarchical dimensions, i.e. in "transdiagnostic" continua. The HiTOP is structured according to super-spectra, spectra, sub-factors, syndromes, components and symptoms. This comes from the current dimensional psychology and quantitative nosology. This article describes the basic principles of the HiTOP project and its potential to integrate into clinical and psychiatric research based on its advantages and limitations. RESULTS: Unlike the DSM, which is descriptive and categorical, the HiTOP is first a dimensional classification. This dimensionality describes psychiatric phenomena on continua, each dimension providing a diagnostic continuum to situate a clinical patient. This dimensionality avoids the reification of categories and it limits the dichotomy between normal and pathological. In addition, HiTOP shows a hierarchical structure: vertical refinement of dimensions allows to circumvent the problem of comorbidities, proposes a new conception of etiopathogenic mechanisms, and improves management of care. DISCUSSION: Thus, we provide an illustration of the applications of a dimensional and hierarchical classification in current clinical practice and scientific research, compared to traditional nosology. The challenges of the HiTOP arise in terms of validity, i.e. in the relation of dimensions with physiopathological mechanisms, in clinical terms, i.e. in the potential contribution of dimensions in relation to categories. Moreover, methodological challenges will be important given the inherent limitations of the HiTOP. CONCLUSION: The HiTOP allows to examine the conceptualization of psychiatric disorders, the search for explanatory mechanisms, and treatment from another perspective for psychiatry.

[Cohort study and multivariate analysis: an epistemological and historical analysis of the Framingham heart study]. / Enquête de cohorte et analyse multivariée : une analyse épistémologique et historique du rôle fondateur de l'étude de Framingham.

BACKGROUND: Begun in 1947 and still ongoing, the epidemiological study of heart disease known as the Framingham study was one of the first prospective studies based on a large cohort and has rapidly been considered as the prototype and model for the cohort study. Nevertheless, an examination of its history reveals that the protocol does not at all correspond to today's standards for this type of study. How, then, can we account for the remarkable reputation of this study? METHODS: This paper consists in an epistemological and historical analysis of the Framingham study that provides some of the answers to this question. In my treatment of the study's methodology, I focus on the issue of how the study population was constituted, and the manner in which the multiple factor analyses were conducted, two issues that are now central to cohort studies and more generally to analytic epidemiology. RESULTS: I show how the study population of Framingham and its long-term follow-up have contributed significantly to the interpretation of the cohort as a sort of "population-laboratory". The data generated by this study, which have been very widely used by epidemiologists and other researchers, are unparalleled in terms of the amount of detailed clinical information available for such a long follow-up period. Furthermore, multivariate statistical modelling, which has become a standard statistical tool for clinical as well as epidemiological studies was introduced in the context of this study to improve the identification of significant factors in the simultaneous analysis of multiple correlations. Multivariate analysis has since proved crucial in shaping the epidemiological concept of "risk factor" and in analysing multifactorial diseases. Indeed, I suggest that the modern idea of multifactorial diseases depends on the adaptation of this statistical method. CONCLUSION: Thus, the Framingham study played a leading role not only in remodelling epidemiology after Second World War, in particular because of its contribution to the establishment of the cohort study as a standard method of investigation in etiological research, but also in constituting the "risk factor approach" to disease.

Clostridiopeptidase B inhibition by plasma marcroglobulins and microbial antiproteases.

Clostridiopeptidase B (EC 3.4.22.8) was not inhibited by stoichiometric amounts of lima bean trypsin inhibitor, ovomucoid trypsin inhibitor, Kuntiz bovine trypsin inhibotor, Kunitz soybean trypsin inhibitor or ovoinhibitor. Activity was diminished at relatively high concentrations of the three latter inhibitors. Human plasma alpha 2-macroglobulin inhibited both the amidase and protease activity of the enzyme. Rat and dog plasmas contained high molecular weight inhibitors, presumably macroglobulins as well. Inhibition by this component was greater in rat plasma than in dog plasma, which may be related to the observation that clostridiopeptidase B-induced generation of kinin activity is indirect in the former plasma, but direct in the later. Leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal) and antipain ([S)-1-carboxy-2-phenylethyl] carbamoyl-L-arginyl-L-valyl-L-argininal) inhibited clostridiopeptidase B (Ki of 2 . 10(-8) and 3 . 10(-8) M, respectively). They were potent inhibitors of clostridiopeptidase B-induced kinin release in dog plasma.

Evidence for an active T-state pig kidney fructose 1,6-bisphosphatase: interface residue Lys-42 is important for allosteric inhibition and AMP cooperativity.

During the R-->T transition in the tetrameric pig kidney fructose-1,6-bisphosphatase (Fru-1,6-P2ase, EC 3.1.3.11) a major change in the quaternary structure of the enzyme occurs that is induced by the binding of the allosteric inhibitor AMP (Ke HM, Liang JY, Zhang Y, Lipscomb WN, 1991, Biochemistry 30:4412-4420). The change in quaternary structure involving the rotation of the upper dimer by 17 degrees relative to the lower dimer is coupled to a series of structural changes on the secondary and tertiary levels. The structural data indicate that Lys-42 is involved in a complex set of intersubunit interactions across the dimer-dimer interface with residues of the 190's loop, a loop located at the pivot of the allosteric rotation. In order to test the function of Lys-42, we have replaced it with alanine using site-specific mutagenesis. The kcat and K(m) values for Lys-42-->Ala Fru-1,6-P2ase were 11 s-1 and 3.3 microM, respectively, resulting in a mutant enzyme that was slightly less efficient catalytically than the normal pig kidney enzyme. Although the Lys-42-->Ala Fru-1,6-P2ase was similar kinetically in terms of K(m) and kcat, the response to inhibition by AMP was significantly different than that of the normal pig kidney enzyme. Not only was AMP inhibition no longer cooperative, but also it occurred in two stages, corresponding to high- and low-affinity binding sites. Saturation of the high-affinity sites only reduced the activity by 30%, compared to 100% for the wild-type enzyme. In order to determine in what structural state the enzyme was after saturation of the high-affinity sites, the Lys-42-->Ala enzyme was crystallized in the presence of Mn2+, fructose-6-phosphate (Fru-6-P), and 100 microM AMP and the data collected to 2.3 A resolution. The X-ray structure showed the T state with AMP binding with full occupancy to the four regulatory sites and the inhibitor Fru-6-P bound at the active sites. The results reported here suggest that, in the normal pig kidney enzyme, the interactions between Lys-42 and residues of the 190's loop, are important for propagation of AMP cooperativity to the adjacent subunit across the dimer-dimer interface as opposed to the monomer-monomer interface, and suggest that AMP cooperativity is necessary for full allosteric inhibition by AMP.

Crystal structures of the active site mutant (Arg-243-->Ala) in the T and R allosteric states of pig kidney fructose-1,6-bisphosphatase expressed in Escherichia coli.

The active site of pig kidney fructose-1,6-bisphosphatase (EC 3.1.3.11) is shared between subunits, Arg-243 of one chain interacting with fructose-1,6-bisphosphate or fructose-2,6-bisphosphate in the active site of an adjacent chain. In this study, we present the X-ray structures of the mutant version of the enzyme with Arg-243 replaced by alanine, crystallized in both T and R allosteric states. Kinetic characteristics of the altered enzyme showed the magnesium binding and inhibition by AMP differed slightly; affinity for the substrate fructose-1,6-bisphosphate was reduced 10-fold and affinity for the inhibitor fructose-2,6-bisphosphate was reduced 1,000-fold (Giroux E, Williams MK, Kantrowitz ER, 1994, J Biol Chem 269:31404-31409). The X-ray structures show no major changes in the organization of the active site compared with wild-type enzyme, and the structures confirm predictions of molecular dynamics simulations involving Lys-269 and Lys-274. Comparison of two independent models of the T form structures have revealed small but significant changes in the conformation of the bound AMP molecules and small reorganization of the active site correlated with the presence of the inhibitor. The differences in kinetic properties of the mutant enzyme indicate the key importance of Arg-243 in the function of fructose-1,6-bisphosphatase. Calculations using the X-ray structures of the Arg-243-->Ala enzyme suggest that the role of Arg-243 in the wild-type enzyme is predominantly electrostatic in nature.

Synthesis of peptidyl fluoromethyl ketones and peptidyl alpha-keto esters as inhibitors of porcine pancreatic elastase, human neutrophil elastase, and rat and human neutrophil cathepsin G.

Comparison of MeO-Suc-Val-Pro-Phe-CO2Me (29) and MeO-Suc-Ala-Ala-Pro-Phe- CO2Me (25) with their corresponding trifluoromethyl ketones 9a and 9b, respectively, in rat and human neutrophil cathepsin G assays showed the alpha-keto esters to be more potent inhibitors. Likewise, Ac-Pro-Ala-Pro-Ala-CO2Me (21) was more potent than its corresponding trifluoromethyl ketone (9c) in both porcine pancreatic elastase and human neutrophil elastase assays. Within a set of Ala-Ala-Pro-Val-CF3 elastase inhibitors, the carbobenzyloxy (Cbz) N-protecting group conferred greater potency as a P5 site recognition unit for elastase than did dansyl, methoxysuccinyl, or tert-butyloxycarbonyl. Initial inhibition of elastase was greater when trifluoromethyl ketone 9f was added from a stock solution of dimethyl sulfoxide than when it had been buffer-equilibrated prior to assay, which suggests that the nonhydrated ketone is the more effective form of the inhibitor. The most potent elastase inhibitor we report is Na-(Ad-SO2)-N epsilon-(MeO-Suc)Lys-Pro-Val-CF3 (16) which has a Ki of 0.58 nM.

Copper and zinc ion binding by bovine, dog, and rat serum albumins.

An ultrafiltration technique was used to study stripping by glycine of the first copper and zinc ion equivalents bound by bovine, dog, and rat serum albumins at pH 7.5. Affinity of dog serum albumin for copper was poorer than for the other albumins, consistent with the absence in the former albumin of the copper binding site present at the amino terminus of the latter albumins. Affinities of all three proteins for zinc were similar, suggesting that the albumin amino terminus is not the primary zinc ion binding site.

Field demonstration of pervaporation for the separation of volatile organic compounds from a surfactant-based soil remediation fluid.

As part of a Department of Defense project, the US Environmental Protection Agency was responsible for designing, building and field operating a pilot-scale pervaporation unit. The field site was an active dry cleaning facility on the grounds of Marine Corps Base Camp Lejeune in Jacksonville, NC. The overall goal of the project was to remove tetrachloroethylene (PCE) from the soil beneath the dry cleaning shop using a surfactant-based soil remediation fluid and to recycle/reuse the surfactant. In order to reinject the recovered surfactant, the pervaporation unit was required to achieve an average 95% removal of contaminants from the extracted fluid over the duration of the test period. PCE removal averaged 95.8% during peak surfactant levels and exceeded 99.9% in the absence of surfactant, thereby meeting the reinjection requirement. Removal of a group of secondary contaminants at the site, termed Varsol compounds, was monitored via concentrations of three Varsol marker compounds: decane, undecane and 1,3,5-trimethylbenzene. The pervaporation system processed 100,000 gal of groundwater and surfactant solution over a period of 70 days. In order to evaluate and validate process performance, a variety of process variables and properties were monitored over the course of the demonstration. Pervaporation costs are projected to be on the order of $20 per 1000 gal of surfactant solution treated for a moderate size system (10 gpm).

Consecutive zinc balance trials in growing rats.

Rats were fed a purified egg white-based diet containing 5 ppm Cu and 2, 14, or 57 ppm Zn. Zinc and copper balances were determined for eight consecutive weekly trial periods. The zinc-deficient group almost ceased to gain weight and was in slightly negative zinc balance. Groups of rats fed 14 and 57 ppm Zn gained weight at equal rates. These groups were in strongly positive zinc balance for four weeks; thereafter, they fed 57 ppm Zn retained about two times as much zinc as did the group fed the diet containing 14 ppm Zn. All groups were in null or slightly negative copper balance throughout the trial. These results suggest that zinc accumulation may be homeostatically controlled to a level in excess of that needed for maximum growth.

Tissue-and metal-specific effects of thiolacrylic acids in rats.

Kidney copper increased 12- to 18-fold above the normal level in rats administered alpha-mercapto-beta-(2-furyl)acrylic acid (MFA). Kidney zinc increased twofold; plasma zinc increased more than 10-fold and liver zinc increased 30-50%. No other changes in copper, iron, and zinc concentrations were found in these tissues or in bone, brain, heart, lung, skeletal muscle, spleen, or testis. Related compounds produced similar effects, although MFA and its disulfide were the most potent of the compounds tested. These increases in tissue copper and zinc were largely complete after 2-5 d of daily administration of compound. Increased plasma zinc returned toward normal with a half-life of 1.0 d for the process, after dosing was ended; albumin was identified as the species binding the excess zinc in plasma. Kidney copper and zinc, which had increased in the ratio of 3 Cu/Zn, returned to normal levels after dosing was stopped with half-lives of 2.1-2.5 d. Consistent with the observations of highly tissuespecific effects of MFA, copper and zinc balances over 8 weeks of trials were found to be not greatly affected by administration of the compound. Thus, it was not established whether excess metal in affected organs derived from enhanced retention of dietary metal or redistribution from other tissues. Kidney copper and zinc and serum zinc increased even in zinc-deficient rats administered MFA.

Ipsilateral omovertebral bones in the levator scapulae muscle and the rhomboid muscle in a Sprengel deformity: case report.

Our interest was stimulated by the uncommon case of a 4-year-old girl who presented a Sprengel deformity associated with two omovertebral bones on the same side. The first omovertebral bone was situated in the levator scapulae muscle and the second omovertebral bone was lying in the rhomboid muscle. The removal of these two bones was combined with a Woodward procedure to obtain a good correction.

[Anterior spinal fusion by thoracoscopy. A non-traumatic technique]. / La spondylodèse antérieure sous thoracoscopie: une technique atraumatique.

PURPOSE OF THE STUDY: Video assisted thoracic surgery (VATS) is a new modality which allows visualization of, and access to the intrathoracic organs without thoracotomy. Recently, this technique has been used for anterior thoracic spine approach to perform surgery which previously required standard postero-lateral thoracotomy. The authors report their initial experience of anterior spinal fusion using thoracoscopy and give a detailed description of their surgical procedure. MATERIAL AND METHODS: This technique, started on June 1993, was performed only in one level 1 in 10 patients who had thoracic spine trauma with fracture or luxation. The procedure was performed in the lateral decubitus position. The patient was prepared in the standard manner for a full thoracotomy. Surgical instruments that are needed for conversion to an open procedure must be in the operative room. Ventilation was stopped to the ipsilateral lung. Lung's collapse of the surgical side was obtained with a double lumen tube. Carbon dioxide (CO2) insufflation was used to further collapse. The first thoracoscopic portal was placed through the sixth or seventh intercostal space in the posterior axillary line, which was the safest place. All subsequent portals were placed under thoracoscopic visualization, in a triangular way as recommended by Landreneau (1992). Only open trocars were used to avoid complication of CO2 insufflation. Once the target level has been defined, a needle was placed into the disc space and roentgenographic confirmation obtained. The parietal pleura was then divided using monopolar electrocautery. Segmental vessels of the operation field lied transversely across the midportion of the vertebral body. They were mobilised and systematically ligated with endoscopic clip to simplify the procedure. Then the intervertebral space was opened and bone and disc were removed, restricted to the anterior and middle third. The graft was placed into the thoracic cavity by using a high density calcium hydroxyapatite ceramic block. Peroperative radiologic control ascertained the good position of the implant. At the end of the procedure a chest tube was placed through the lower trocar site and the lung re-expanded. A post operative CT Scan controlled good position of the graft and complete lung expansion. Contra-indications for VATS are previous surgical procedures or empyema causing extensive pleural adhesions. Procedures not appropriate for VATS approach are some that require anterior instrumentation for stabilisation, burst fracture, or fracture with posterior wall involved. RESULTS: The planned procedure was accomplished in all but one patient who required conversion to an open procedure because of segmental artery bleeding. Mean operative time was 1 h 45 mm, and mean estimated blood loss was 650 cc. There was no complication from CO2 insufflation neither postoperative complication. With an average of 2 years follow up, anterior grafting is as good as an open technique, radiologic evaluation according to Uchida (1990) showed good incorporation of each block without any radiolucent line or displacement. DISCUSSION: According to literature this technique was performed safely in 10 cases, especially without any respiratory complications and chronic pain (impairement of pulmonary function, re-expansion failure, incisional complications, rib fractures, chronic pain and malfunction of the chest wall, limitation of shoulder girdle motion) which are considered to be the main disadvantage of traditional thoracotomy. Many authors previously used VATS for multi level thoracic discectomy for correction of spinal deformities (Mack 1995), spinal reconstructive surgery (Mac Afee 1995) or removal of protrude thoracic disc (Rosenthal 1994). CONCLUSION: This original technique demonstrates that thoracoscopy for anterior thoracic surgery is better for the patients, reducing surgical trauma of the chest wall and to the lung parenchyma (in term of post operative comfort, sh

[The outpatient clinic's role : port of entrance and dispatching centre ?]. / La clinique externe : comment peut-elle prétendre aux rôles de porte d'entrée et de plaque tournante?

This article presents an overview of the plan of transformation of services adopted in 1998 at Louis-H. Lafontaine Hospital. The authors present the history, principles and models, the role played by outpatients clinics as well as the challenges related to the implementation of this new plan.

[Risk factors and the issue of the boundary between the normal and the pathological: an epistemological analysis]. / Les facteurs de risque et le problème de la démarcation entre le normal et le pathologique : une analyse épistémologique.

The fact that numerous risk factors are continuous raises the problem of the boundary between the normal and the pathological states. Moreover, a risk factor approach to disease deeply calls into question the relevance of these concepts. In this paper, I propose an epistemological analysis of the notion of "continuity" as it is used in the context of "risk factor epidemiology".