Psychiatric clinical profiles and pharmacological interactions in COVID-19 inpatients referred to a consultation liaison psychiatry unit

Introduction

The Coronavirus Disease 2019 (COVID-19) can affect mental health in different ways. There is little research about psychiatric complications in hospitalized patients with COVID-19.

Objectives

The aim of the study was to describe the psychiatric clinical profile and pharmacological interactions in COVID-19 inpatients referred to a Consultation-Liaison Psychiatry (CLP) unit.

Methods

This is a cross-sectional retrospective study, carried out at a tertiary hospital in Spain, in inpatients admitted because of COVID-19 and referred to our CLP Unit from March 17,2020 to April 28,2020. Clinical data were extracted from electronic medical records. The patients were divided in three groups depending on psychiatric diagnosis: delirium, severe mental illness (SMI) and non-severe mental illness (NSMI).

Results

Of 71 patients included (median [ICR] age 64 [54-73] years; 70.4% male), 35.2% had a delirium, 18.3% had a SMI, and 46.5% had a NSMI. Compared to patients with delirium and NSMI, patients with SMI were younger, more likely to be institutionalized and were administered less anti-COVID19 drugs. Mortality was higher among patients with delirium (21.7%) than those with SMI (0%) or NSMI (9.45%). The rate of side effects due to interactions between anti-COVID19 and psychiatric drugs was low, mainly drowsiness (4.3%) and borderline QTc prolongation (1.5%).

Conclusions

Patients affected by SMI were more often undertreated for COVID-19. However, the rate of interactions was very low, and avoidable with a proper evaluation and drug-dose adjustment. Half of the patients with SMI were institutionalized, suggesting that living conditions in residential facilities could make them more vulnerable to infection.

Disclosure

No significant relationships.

Azospirillum brasilense Az39, a model rhizobacterium with AHL quorum-quenching capacity

AIMS

The aim of this research was to analyse the quorum-sensing (QS) and quorum-quenching (QQ) mechanisms based on N-acyl-l-homoserine lactones (AHLs) in Azospirillum brasilense Az39, a strain with remarkable capacity to benefit a wide range of crops under agronomic conditions.

METHODS AND RESULTS

We performed an in silico and in vitro analysis of the quorum mechanisms in A. brasilense Az39. The results obtained in vitro using the reporter strains Chromobacterium violaceum and Agrobacterium tumefaciens and liquid chromatography coupled with mass-mass spectrometry analysis showed that although Az39 does not produce AHL molecules, it is capable of degrading them by at least two hypothetical enzymes identified by bioinformatics approach, associated with the bacterial cell. In Az39 cultures supplemented with 500 nmol l^-1 of the C3 unsubstituted AHLs (C4, C6, C8, C10, C12, C14), AHL levels were lower than in noninoculated LB media controls. Similar results were observed upon the addition of AHLs with hydroxy (OH-) and keto (oxo-) substitutions in C3. These results not only demonstrate the ability of Az39 to degrade AHLs. They also show the wide spectrum of molecules that can be degraded by this bacterium.

CONCLUSIONS

Although A. brasilense Az39 is a silent bacterium unable to produce AHL signals, it is able to interrupt the communications between other bacteria and/or plants by a QQ activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report confirming by unequivocal methodology the ability of A. brasilense, one of the most agriculturally used benefic bacteria around the world, to degrade AHLs by a QQ mechanism.

Abstract P4-21-16: Phase III trial to evaluate patient´s preference for subcutaneous versus intravenous trastuzumab administration in patients with HER2 positive advanced breast cancer (ABC) under IV trastuzumab (IV-t) treatment for at least 4 months. ChangHER-SC study (GEICAM/2012-07)

Background: Patients with HER2-positive ABC, receive anti-HER2 treatment for several months or even years. IV-t is administered weekly or 3-weekly, mandating patients to visit the hospital on a regular basis to receive infusions. This has inconveniences for patients and increase treatment costs. Subcutaneous administration could improve convenience of trastuzumab therapy. This study was designed to evaluate patient's preference for IV-t or SC trastuzumab (SC-t) in ABC patients.

Methods:This is a phase III, open label, multicenter study inpatients with HER2 positive ABC, receiving IV-t for at least 4 months and without evidence of disease progression. Patients received 600 mg of SC-t, either from a vial or from a single injection device (SID), every 3 weeks for 4 cycles. Before starting SC-t, patients received an additional IV-t cycle. Patients were randomized 1:1 to arm A, receiving 2 cycles of SC-t with vial followed by 2 cycles with SID or arm B, receiving the opposite sequence. After cycle 4, patients decided to continue with IV-t or SC-t till disease progression. Stratification criteria were the associated therapy (Chemotherapy, Hormone-therapy or none) and its administration route (IV, oral or none). Patients completed a questionnaire of experiences and preferences at three time points: before starting SC-t, after cycle 2 and after cycle 4. Health Care Professionals completed a satisfaction questionnaire every 5 patients. The primary objective was to evaluate patient´s preference for IV-t or SC-t (after cycle 2) and, secondary objectives were, to evaluate patient´s preference between the two SC-t administrations (vial or SID) after cycle 4, Health Care Professional satisfaction, associated costs of the administration options (Time and Motion pharmacoeconomic study) and safety.

Results: From September-13 to July-15, 166 patients were randomized (81 arm A, 85 arm B) in 26 Spanish sites from GEICAM. Median age was 60 years (35-93), 88% of patients were postmenopausal and 123 and 42 had an ECOG PS of 0 and 1, respectively. The median duration of prior IV-t for ABC was 1.8 years (range: 0.3-14). Patients received a median of 2 previous lines of Chemotherapy and/or Hormone-therapy (range: 1-9). Twenty patients were receiving pertuzumab at inclusion. According to patient questionnaires completed after cycle 2, 137 patients preferred the SC-t (66 arm A, 71 arm B), 11 the IV-t (6 arm A, 5 arm B), 11 didn't have a preference (4 arm A, 7 arm B), and 7 didn't answer (3 progressed, 2 withdrew participation before cycle 2 and 2 unknown reason). Three of the 11 patients choosing IV-t were receiving IV treatment as accompanying therapy; after cycle 4 five of these 11 patients finally continued with SC-t, 5 with IV-t and 1 progressed. From the 11 patients without any preference 7 received SC-t, 2 receive IV-t and 2 progressed; from the 137 patients preferring SC-t, 125 actually received it, 3 received IV-t and 9 progressed.

Conclusions: Our study shows that 82.5% of patients preferred the SC-t over the IV-t. Treatment choice was not influenced by the accompanying therapy.

Citation Format: Ciruelos EM, Montaño Á, Rodríguez CA, González-Flores E, Lluch A, Garrigós L, Quiroga V, Antón A, Malón D, Chacón JI, Velasco M, Gonzalez-Cortijo L, Jolis L, Pascual T, Amigo Y, Casas M, Cámara MC, Carrasco E, Casas A. Phase III trial to evaluate patient´s preference for subcutaneous versus intravenous trastuzumab administration in patients with HER2 positive advanced breast cancer (ABC) under IV trastuzumab (IV-t) treatment for at least 4 months. ChangHER-SC study (GEICAM/2012-07) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-16.

In vitro assessment of potential intestinal absorption of some phenolic families and carboxylic acids from commercial instant coffee samples

Coffee is a source of flavors and bioactive compounds with wide differences in their bioaccesibility.

Abstract P3-15-02: A prospective, open label, non-comparative trial to determine the incidence of chemotherapy-induced nausea and vomiting associated with the docetaxel-cyclophosphamide regimen in early breast cancer patients. Results from the GEICAM 2009-02 study

Background: Docetaxel-Cyclophosphamide (TC) has become a common chemotherapy regimen for moderate-high risk Early Breast Cancer (EBC) patients. The incidence of chemotherapy induced nausea and vomiting (CINV) with TC together with an adequate standard anti-emetic therapy with 5-HT3 antagonist and corticosteroids are unknown. This study investigates the incidence of emesis control (complete response), defined as no vomiting (any grade of NCI CTCAE version 4.0) and no use of rescue treatment within 120 hours after the first cycle of TC. Secondary objective evaluates the efficacy of Aprepitant in non-responding patients.

Methods: EBC patients with no prior moderate-high risk CINV were included. Patients received Docetaxel 75 mg/m2 plus Cyclophosphamide 600 mg/m2 IV every three weeks. Antiemetic treatment consisted of oral Dexamethasone (D) 8 mg (at night) on day 0; oral D 8 mg x 3 (in the morning, 1 hour before chemotherapy and at night) plus 5-HT3 antagonists on day 1; and oral D 8 mg x 2 (in the morning and at night) on days 2 and 3. Non-responding patients (vomiting or need of rescue therapy in the first cycle) were offered participation in the efficacy phase (Aprepitant 125mg day 1 and 80 mg days 2 and 3 added to the standard antiemetic therapy in cycle 2). In addition to the standard NCI-CTCAE adverse event collection, a patient´s diary (from day 1 to 6) and the FLIE (Functional Living Index-Emesis questionnaire) were used. Assuming a 25% (+/- 6%) of patients resistant to standard antiemetic therapy, 212 patients were estimated.

Results: From May-11 to March-13, 212 EBC patients were included. Median age was 57 years (range 34-82), 29.3% were premenopausal. Twenty-seven patients were excluded from the main analysis because of major protocol violations (25) or consent withdrawal (2). Twenty-four patients (13%; IC95%: 8.2 – 17.8) did not respond to standard antiemetics and entered the efficacy phase with Aprepitant. From these 24 patients, 14 (56%; IC95%: 36.5 – 75.5) achieved a complete response on cycle 2. No adverse events related to Aprepitant were observed.

Conclusions: Proper use of standard antiemetic therapy for early breast cancer patients treated with TC provides a high control rate (87%). Among no responding patients, about half of them were rescued with Aprepitant. Identification of the non-responding patients could lead to a better antiemetic control with Aprepitant from the first cycle.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-15-02.

Fatty acids profiles of some Spanish wild vegetables

Polyunsaturated fatty acids play an important role in human nutrition, being associated with several health benefits. The analyzed vegetables, in spite of its low fat content, lower than 2%, present a high proportion of polyunsaturated fatty acids of n-3, n-6 and n-9 series, such as α-linolenic, linoleic and oleic acids, respectively. Wild edible plants contain in general a good balance of n-6 and n-3 fatty acids. The present study tries to contribute to the preservation and valorization of traditional food resources, studying the fatty acids profile of 20 wild vegetables by gas-liquid chromatography with flame ionization detection. Results show that species in which leaves are predominant in their edible parts have in general the highest polyunsaturated fatty acid/saturated fatty acid ratios: Rumex pulcher (5.44), Cichorium intybus (5.14) and Papaver rhoeas (5.00). Due to the low n-6/n-3 ratios of the majority of the samples, they can be considered interesting sources of n-3 fatty acids, especially those with higher total fat amount, such as Bryonia dioica, Chondrilla juncea or Montia fontana, with the highest contents of α-linolenic acid (67.78, 56.27 and 47.65%, respectively). The wild asparaguses of Asparagus acutifolius and Tamus communis stand out for their linoleic acid content (42.29 and 42.45%, respectively). All these features reinforce the interest of including wild plants in diet, as an alternative to the variety of vegetables normally used.

HIV/STI co-infection among men who have sex with men in Spain

In Spain, neither the HIV nor the STI national surveillance systems collect information on HIV/STI co-infection. However, there are two networks based on HIV/STI clinics which gather this data. We describe HIV prevalence in men who have sex with men (MSM) diagnosed with infectious syphilis and/or gonorrhoea in 15 STI clinics; and concurrent diagnoses of STI in MSM newly diagnosed with HIV in 19 HIV/STI clinics. In total, 572 MSM were diagnosed with infectious syphilis and 580 with gonorrhoea during 2005-2007. HIV prevalence among syphilis and gonorrhoea cases was 29.8% and 15.2% respectively. In the multivariate analysis, HIV/syphilis co-infection was associated with being Latin American; having a history of STI; reporting exclusively anal intercourse; and having sex with casual or several types of partners. HIV and gonorrhoea co-infection was associated with age older than 45 years; having no education or only primary education completed; and having a history of STI. In total, 1,462 HIV infections were newly diagnosed among MSM during 2003-2007. Of these, 31.0% were diagnosed with other STI at the same time. Factors associated with STI co-infection among new HIV cases in MSM were being Latin American; and having sex with casual partners or with both steady and casual partners. In Spain, a considerable proportion of MSM are co-infected with HIV and STI.

Preliminary findings of quorum signal molecules in clinically stable lung allograft recipients

BACKGROUND

Infection with bacteria such as Pseudomonas is common in lung allograft recipients, particularly during chronic rejection. Analysis of sputum samples from patients with cystic fibrosis infected with Pseudomonas aeruginosa or Burkholderia cepacia has indicated the presence of bacterial N-acylhomoserine lactones (AHLs) quorum sensing signalling molecules. AHLs not only control the expression of bacterial virulence genes but are also involved in stimulating the maturation of antibiotic resistant biofilms and host chemokine release. It was hypothesised that AHLs may be detected even in clinically stable lung transplant recipients free of clinical infection or rejection.

METHODS

Three 60 ml samples of bronchoalveolar lavage (BAL) fluid were taken from nine stable lung transplant recipients 3-12 months after transplantation. Detection of AHLs was carried out on dichloromethane extracted supernatants using the bioluminescence based AHL reporter plasmid pSB1075. This responds to the presence of AHLs with long acyl chains (C10-C14), generating light. Synthetic AHLs were included as positive controls.

RESULTS

Five of the nine BAL fluid supernatants exhibited AHL activity, suggesting the presence of AHLs with long N-acyl chains. There was no correlation between the levels of AHLs detected or their absence and BAL fluid microbiology or diagnosis before transplantation.

CONCLUSIONS

This is the first evidence for the presence of AHL quorum sensing signals in human lung allograft recipients, even in subjects with no rejection or apparent infection. Further longitudinal follow up of these preliminary findings is required to elucidate potential links with infection, rejection, and allograft deterioration.

The global posttranscriptional regulator RsmA modulates production of virulence determinants and N-acylhomoserine lactones in Pseudomonas aeruginosa

Posttranscriptional control is known to contribute to the regulation of secondary metabolism and virulence determinants in certain gram-negative bacteria. Here we report the isolation of a Pseudomonas aeruginosa gene which encodes a global translational regulatory protein, RsmA (regulator of secondary metabolites). Overexpression of rsmA resulted in a substantial reduction in the levels of extracellular products, including protease, elastase, and staphylolytic (LasA protease) activity as well as the PA-IL lectin, hydrogen cyanide (HCN), and the phenazine pigment pyocyanin. While inactivation of rsmA in P. aeruginosa had only minor effects on the extracellular enzymes and the PA-IL lectin, the production of HCN and pyocyanin was enhanced during the exponential phase. The influence of RsmA on N-acylhomoserine lactone-mediated quorum sensing was determined by assaying the levels of N-(3-oxododecanoyl)homoserine lactone (3-oxo-C12-HSL) and N-butanoylhomoserine lactone (C4-HSL) produced by the rsmA mutant and the rsmA-overexpressing strain. RsmA exerted a negative effect on the synthesis of both 3-oxo-C12-HSL and C4-HSL, which was confirmed by using lasI and rhlI translational fusions. These data also highlighted the temporal expression control of the lasI gene, which was induced much earlier and to a higher level during the exponential growth phase in an rsmA mutant. To investigate whether RsmA modulates HCN production solely via quorum-sensing control, hcn translational fusions were employed to monitor the regulation of the cyanide biosynthesis genes (hcnABC). RsmA was shown to exert an additional negative effect on cyanogenesis posttranscriptionally by acting on a region surrounding the hcnA ribosome-binding site. This suggests that, in P. aeruginosa, RsmA functions as a pleiotropic posttranscriptional regulator of secondary metabolites directly and also indirectly by modulating the quorum-sensing circuitry.

A comparison of the adhesion of mammalian cells and Staphylococcus epidermidis on fibronectin-modified polymer surfaces

The modification of polymer surfaces to mimic the extracellular matrix, and therefore, stimulate cell growth via receptor-mediated interactions, is one approach used to promote the integration of tissue-engineering scaffolds and biomaterials into the body. However, by optimizing surfaces for tissue integration it is likely that bacterial adhesion may also be affected, resulting in a greater risk of biomaterial-related infection. This could be detrimental to both the implant and the patient because biomaterial related infections are particularly resistant to host defenses and antibiotics. In this study, we analyzed the adhesion of a Staphylococcus epidermidis clinical isolate and 3T3 rat fibroblasts to tissue culture plastic coated with varying concentrations of fibronectin (Fn). Bacterial adhesion was always lower than tissue culture plastic and appeared to decrease with increasing Fn concentrations. Mammalian cell adhesion to Fn exceeded adhesion to tissue culture plastic but did not differ significantly over the range of protein concentrations or between 1 and 4 h of incubation. In most cases, the total surface coverage did not vary with time or Fn concentration, indicating that maximal cell adhesion and spreading occurred rapidly and at low protein concentrations. This study suggests that, by controlling the density of proteins or ligands on a surface, we can potentially optimize mammalian cell adhesion without stimulating bacterial adhesion, hence reducing the likelihood of infection.

The LuxM homologue VanM from Vibrio anguillarum directs the synthesis of N-(3-hydroxyhexanoyl)homoserine lactone and N-hexanoylhomoserine lactone

Vibrio anguillarum, which causes terminal hemorrhagic septicemia in fish, was previously shown to possess a LuxRI-type quorum-sensing system (vanRI) and to produce N-(3-oxodecanoyl)homoserine lactone (3-oxo-C10-HSL). However, a vanI null mutant still activated N-acylhomoserine lactone (AHL) biosensors, indicating the presence of an additional quorum-sensing circuit in V. anguillarum. In this study, we have characterized this second system. Using high-pressure liquid chromatography in conjunction with mass spectrometry and chemical analysis, we identified two additional AHLs as N-hexanoylhomoserine lactone (C6-HSL) and N-(3-hydroxyhexanoyl)homoserine lactone (3-hydroxy-C6-HSL). Quantification of each AHL present in stationary-phase V. anguillarum spent culture supernatants indicated that 3-oxo-C10-HSL, 3-hydroxy-C6-HSL, and C6-HSL are present at approximately 8.5, 9.5, and 0.3 nM, respectively. Furthermore, vanM, the gene responsible for the synthesis of these AHLs, was characterized and shown to be homologous to the luxL and luxM genes, which are required for the production of N-(3-hydroxybutanoyl)homoserine lactone in Vibrio harveyi. However, resequencing of the V. harveyi luxL/luxM junction revealed a sequencing error present in the published sequence, which when corrected resulted in a single open reading frame (termed luxM). Downstream of vanM, we identified a homologue of luxN (vanN) that encodes a hybrid sensor kinase which forms part of a phosphorelay cascade involved in the regulation of bioluminescence in V. harveyi. A mutation in vanM abolished the production of C6-HSL and 3-hydroxy-C6-HSL. In addition, production of 3-oxo-C10-HSL was abolished in the vanM mutant, suggesting that 3-hydroxy-C6-HSL and C6-HSL regulate the production of 3-oxo-C10-HSL via vanRI. However, a vanN mutant displayed a wild-type AHL profile. Neither mutation affected either the production of proteases or virulence in a fish infection model. These data indicate that V. anguillarum possesses a hierarchical quorum sensing system consisting of regulatory elements homologous to those found in both V. fischeri (the LuxRI homologues VanRI) and V. harveyi (the LuxMN homologues, VanMN).

Mucinous appendicular cystadenocarcinoma and pregnancy

Primary appendicular adenocarcinoma is rare. We report an unusual mucinous appendicular adenocarcinoma during pregnancy. To our knowledge, this is the second reported case in the literature. A mucinous appendicular cystoadenocarcinoma was discovered unexpectedly and coincidentally during a cesarean section performed in term pregnancy. An appendectomy was simultaneously performed, followed by a right hemicolectomy. Given the exceptionally low incidence tumors co-existing with pregnancy, we recommend a careful and complete appendix examination during cesarean and postpartum sterilization, and subsequent removal of tumors should they exist.

Doppler-derived gradients in normally functioning Monostrut Björk-Shiley prostheses

In summary, reference values of Doppler gradients obtained in a large number of patients with normal-functioning mitral and aortic Monostrut Björk-Shiley prostheses are reported. It is shown that the value of the transprosthetic gradient increases with decreasing valve size in patients with aortic prostheses. No individual significant variations of the transprothetic Doppler gradient during a 3-year follow-up were observed.

A neuraminidase from Streptococcus pneumoniae has the features of a surface protein

A gene from Streptococcus pneumoniae (nanA), with features entirely consistent with a neuraminidase gene, has been sequenced. High levels of neuraminidase activity were obtained after cloning of this gene, without flanking sequences, into a high-expression vector. RNA hybridization studies have shown that the gene is transcribed by a virulent pneumococcus strain. The predicted molecular weight of the protein and certain amino acid sequences are typical of other neuraminidases. NanA contains the four copies of the sequence SXDXGXTW that is present in all the bacterial neuraminidases previously described. Kyte and Doolittle analysis showed that NanA is a hydrophilic protein with hydrophobic domains at the N terminus and the C terminus. A putative signal peptide was found in the N terminus of this protein, indicating that the protein is exported from the pneumococcus. The C terminus has the features of the anchor motif found in other surface proteins from gram-positive bacteria. Electron microscopy studies showed the presence of neuraminidase associated with the cell surface of the pneumococcus.

Expression of adhesion molecules by endothelial cells of early human decidua

The expression of adhesion molecules by endothelial cells (EC) of early human decidua was studied with monoclonal antibodies and the immunoperoxidase technique. Although E-selectin, INCAM-110 and VCAM-1 were poorly detected on decidual EC, ICAM-1, P-selectin and DR antigens were highly expressed by these cells, some of which showed high endothelial venule-like morphology. Our results suggest that decidual EC are activated, and are probably involved in the active recruitment of leucocytes.

Expression of class II HLA molecules by endothelial cells of human decidua

Many authors have documented a high level of expression of class II HLA molecules by decidua. Although macrophages appear to be responsible for this, we show in this article that endothelial cells (EC) of the venules and capillaries of human decidua also strongly express class II molecules, whereas EC of chorionic villi do not. We discuss this finding in the context of the maternal-fetal immune interaction.

Prenatal ultrasound semiography of anencephaly: sonographic-pathological correlations

A better understanding of the ultrasound findings in each of the different types of fetal anencephaly can help to reduce the number of false-negative diagnoses of this condition during the prenatal period. Errors in the estimation of the remaining cerebral tissue (angiomatous stroma, area cerebrovasculosa) can cause false-negative diagnoses or diagnostic confusion with cases of microcephaly or incomplete ossification of the cranial vault. In a retrospective study, 30 fetuses with anencephaly (diagnosed at 13-38 weeks of gestation) were grouped, in terms of their ultrasound results, according to the Nanagas classification. The ultrasound diagnoses were then correlated with those found through autopsy, to identify any errors in the ultrasound classification.

Hypoglycemic action of Salvia lavandulifolia Vahl. spp. oxyodon:a contribution to studies on the mechanism of action

Having previously demonstrated the hypoglycemic action of Salvia lavandulifolia Vahl, subspecies oxyodon, the mechanism of action was further investigated. The hypoglycemic action may be the result of several synchronous mechanisms: a) potentiation of insulin release induced by glucose, b) increased peripheral uptake of glucose, c) decreased intestinal absorption of glucose and d) hyperplasia of the pancreatic islet beta cells (seen after chronic treatment).

[Malignant astrocytic glioma of the brain in adults: histologic criteria determining its classification, diagnosis and prognosis]

Eighty-three malignant supratenorial astrocytic gliomas in adult patients were evaluated. The patients underwent surgery and radiotherapy. To establish their influence on survival, 10 histological variables were evaluated (degree of cellularity, polymorphism, predominant cell type, nuclear atypia, mitotic index, vascular proliferation, endothelial hyperplasia, glomeruloid formations, lymphocytic infiltration, necrosis and pseudofences). Two definite levels of aggressivity were found (anaplastic astrocytoma and multiform glioblastoma) with statistically significant differences in survival (p less than 0.025). They were diagnosed on the basis of the presence or absence of necrosis. In the absence of this parameter, vascular phenomena, cellularity and nuclear atypia were found to be valid for the differentiation of the two mentioned groups.

"Shoehorn technique" for inserting Ionescu-Shiley valves in the mitral position

A technique is described for safer and easier insertion of the Ionescu-Shiley valves at the mitral level by using the same principle that applies in the use of a shoehorn.