Multiplexed imaging in live cells using pulsed interleaved excitation spectral FLIM.

Multiplexed fluorescence detection has become increasingly important in the fields of biosensing and bioimaging. Although a variety of excitation/detection optical designs and fluorescence unmixing schemes have been proposed to allow for multiplexed imaging, rapid and reliable differentiation and quantification of multiple fluorescent species at each imaging pixel is still challenging. Here we present a pulsed interleaved excitation spectral fluorescence lifetime microscopic (PIE-sFLIM) system that can simultaneously image six fluorescent tags in live cells in a single hyperspectral snapshot. Using an alternating pulsed laser excitation scheme at two different wavelengths and a synchronized 16-channel time-resolved spectral detector, our PIE-sFLIM system can effectively excite multiple fluorophores and collect their emission over a broad spectrum for analysis. Combining our system with the advanced live-cell labeling techniques and the lifetime/spectral phasor analysis, our PIE-sFLIM approach can well unmix the fluorescence of six fluorophores acquired in a single measurement, thus improving the imaging speed in live-specimen investigation.

Tin(II) Chloride-Catalyzed Direct Esterification and Amidation of tert-Butyl Esters Using α,α-Dichlorodiphenylmethane Under Mild Conditions.

A practical one-pot synthesis of esters and amides from tert-butyl esters via acid chloride was developed. Reactions of tert-butyl esters with α,α-dichlorodiphenylmethane as the chlorinating agent and SnCl2 as catalyst-generated acid chloride intermediates in situ were subsequently used in reactions with a variety of alcohols and amines to afford the corresponding esters and amides in high yields under mild reaction conditions. This catalytic synthetic procedure offers an effective strategy for the facile esterification and amidation of tert-butyl esters.

Direct transformation of benzyl esters into esters, amides, and anhydrides using catalytic ferric(III) chloride under mild conditions.

A facile one-pot transformation of benzyl esters into esters, amides, and anhydrides is described. α,α-Dichlorodiphenylmethane and FeCl3 were employed as the chlorinating agent and catalyst respectively to convert benzyl esters into acid chloride intermediates, which directly reacted with alcohols, amines, and carboxylic acids. Various esters, amides, and anhydrides were readily obtained with high yields under mild conditions. This method is promising for the practical synthesis of esters, amides, and anhydrides from benzyl esters.

Filipendula glaberrima Nakai extract inhibits the bacterial infection by induction of HBD2 and HBD3 expression, and reduction of the inflammatory activity.

Defensins and inflammation are innate immune barriers of the body against infectious pathogens. Searching for a compound that can inhibit infectious diseases by affecting human ß-defensin (HBD) and proinflammatory cytokines is the new trend in research to control bacterial infection. The aim of this study is to provide a natural compound, Filipendula glaberrima Nakai extract (FGE), which is able to induce the expression of an antimicrobial defensin as well as reduce inflammation. FGE induced the expression of HBD2 and HBD3 through activating both p38 and NF-κB signaling pathways. Furthermore, FGE inhibited the expression of TNF-α and IL-6 via p38 and NF-κB pathways in Staphylococcus aureus-stimulated THP1 cells. Injection of FGE alleviated cutaneous erythema and swelling caused by S. aureus injection in mice ears. Taken together, FGE could reduce bacterial infection by inducing the expression of defensin and anti-inflammatory activity.

Recent Advances of 68Ga-Labeled PET Radiotracers with Nitroimidazole in the Diagnosis of Hypoxia Tumors.

Positron emission tomography (PET) is a noninvasive molecular imaging method extensively applied in the detection and treatment of various diseases. Hypoxia is a common phenomenon found in most solid tumors. Nitroimidazole is a group of bioreducible pharmacophores that selectively accumulate in hypoxic regions of the body. Over the past few decades, many scientists have reported the use of radiopharmaceuticals containing nitroimidazole for the detection of hypoxic tumors. Gallium-68, a positron-emitting radioisotope, has a favorable half-life time of 68 min and can be conveniently produced by 68Ge/68Ga generators. Recently, there has been significant progress in the preparation of novel 68Ga-labeled complexes bearing nitroimidazole moieties for the diagnosis of hypoxia. This review provides a comprehensive overview of the current status of developing 68Ga-labeled radiopharmaceuticals with nitroimidazole moieties, their pharmacokinetics, and in vitro and in vivo studies, as well as PET imaging studies for hypoxic tumors.

Recent Advances in Synthetic Routes to Azacycles.

A heterocycle is an important structural scaffold of many organic compounds found in pharmaceuticals, materials, agrochemicals, and biological processes. Azacycles are one of the most common motifs of a heterocycle and have a variety of applications, including in pharmaceuticals. Therefore, azacycles have received significant attention from scientists and a variety of methods of synthesizing azacycles have been developed because their efficient synthesis plays a vital role in the production of many useful compounds. In this review, we summarize recent approaches to preparing azacycles via different methods as well as describe plausible reaction mechanisms.

MSF Enhances Human Antimicrobial Peptide ß-Defensin (HBD2 and HBD3) Expression and Attenuates Inflammation via the NF-κB and p38 Signaling Pathways.

Both defensin and inflammation are part of the human innate immune system that responds rapidly to pathogens. The combination of defensins with pro- or anti-inflammatory effects can be a potential research direction for the treatment of infection by pathogens. This study aimed to identify whether MSF (Miracle Synergy material made using Filipendula glaberrima), a probiotic lysate of Filipendula glaberrima extracts fermented with Lactiplantibacillus plantarum K8, activates the expression of human ß-defensin (HBD2 and HBD3) to protect the host against pathogens and inhibit inflammation caused by S. aureus, in vitro with Western blot analysis, qRT-PCR and in vivo studies with a mouse model were used to evaluate the effects of MSF. The MSF treatment induced HBD2 and HBD3 expression via the p38 and NF-κB pathways. Furthermore, MSF treatment significantly reduced the expression of pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6, and IL-8), also through p38 and NF-κB in S. aureus-induced inflammatory condition. MSF treatment remarkably reduced erythema in mice ears caused by the injection of S. aureus, while K8 lysate treatment did not initiate a strong recovery. Taken together, MSF induced the expression of HBD2 and HDB3 and activated anti-inflammatory activity more than the probiotic lysates of L. plantarum K8. These findings show that MSF is a potential defensin inducer and anti-inflammatory agent.

Streamlining a blood center and hospital transfusion service supply chain with an informatics vendor-managed inventory solution: development, implementation, and 3-month follow-up.

BACKGROUND: The ordering process at Stanford Health Care involved twice-daily shipments predicated upon current stock levels from the blood center to the hospital transfusion service. Manual census determination is time consuming and error prone. We aimed to enhance inventory management by developing an informatics platform to streamline the ordering process and reallocate staff productivity. STUDY DESIGN AND METHODS: The general inventory accounts for more than 50 product categories based on characteristics including component, blood type, irradiation status, and cytomegalovirus serology status. Over a 5-month calibration period, inventory levels were determined algorithmically and electronically. An in-house software program was created to determine inventory levels, optimize the electronic ordering process, and reduce labor time. A 3-month pilot period was implemented using this program. RESULTS: This system showed noninferiority while saving labor time. The average weekly transfused:stocked ratios for cryoprecipitate, plasma, and red blood cells, respectively, were 1.03, 1.21, and 1.48 before the pilot period, compared with 0.88, 1.17, and 1.40 during (p = 0.28). There were 27 (before) and 31 (during) average STAT units ordered per week (p = 0.86). The number of monthly wasted products due to expiration was 226 (before) and 196 (during) units, respectively (p = 0.28). An estimated 7 hours per week of technologist time was reallocated to other tasks. CONCLUSION: An in-house electronic ordering system can enhance information fidelity, reallocate and optimize valuable staff productivity, and further standardize ordering. This system showed noninferiority to the labor-intensive manual system while freeing up over 360 hours of staff time per year.

PITUITARY EVALUATION IN PATIENTS WITH LOW PROSTATE-SPECIFIC ANTIGEN.

OBJECTIVE: To evaluate pituitary function in men with a low screening prostate-specific antigen (PSA) of ≤0.1 ng/mL and test the hypothesis that low PSA is associated with hypogonadism alone or other hormone deficiency. METHODS: This was a case-control study evaluating the rates of hypogonadism and low insulin-like growth factor (IGF)-1 in a cohort of men with low or normal screening PSA level. Sixty-four men >40 years old without known prostate disease were divided into a low-PSA group (PSA ≤0.1 ng/mL) and normal-PSA group (PSA 1 to 4 ng/mL). Hormonal evaluation included total testosterone, prolactin, luteinizing hormone, follicle-stimulating hormone, IGF-1, growth hormone, thyroid-stimulating hormone, free thyroxine, morning cortisol, and adrenocorticotropic hormone. The difference between each patient's observed IGF-1 and the IGF-1 age-specific lower limit was calculated. The odds ratios (ORs) for having hypogonadism and associated 95% confidence intervals (CIs) were calculated using the Cochran-Mantel-Haenszel test. RESULTS: The rate of hypogonadism was significantly higher in the low-PSA group (n = 44) compared with the normal-PSA control group (n = 20) (45.5% vs. 15.0%; OR, 4.7; 95% CI, 1.2 to 18.4; P = .027). The total testosterone in the low-PSA group was significantly lower compared with the control group (181.7 ng/dL vs. 263.7 ng/dL; P = .008). IGF-1 values were below their lower bound in 18.6% of subjects in the low-PSA group, compared with 0% in the control group. CONCLUSION: Men with low PSA have significantly higher rates of hypogonadism and low IGF-1 compared with those with normal PSA. In such men, we recommend hormonal evaluation to exclude associated pituitary dysfunction. ABBREVIATIONS: BMI = body mass index; GH = growth hormone; IGF-1 = insulin-like growth factor 1; MRI = magnetic resonance imaging; PSA = prostate-specific antigen; T2DM = type 2 diabetes mellitus; VA-NWIHCS = VA-Nebraska Western Iowa Health Care System.

Challenges in detection and treatment of multidrug resistant tuberculosis patients in Vietnam.

BACKGROUND: Vietnam is ranked 14(th) among 27 countries with high burden of multidrug-resistant tuberculosis (MDR-TB). In 2009, the Vietnamese government issued a policy on MDR-TB called Programmatic Management of Drug-resistant Tuberculosis (PMDT) to enhance and scale up diagnosis and treatment services for MDR-TB. Here we assess the PMDT performance in 2013 to determine the challenges to the successful identification and enrollment for treatment of MDR-TB in Vietnam. METHODS: In 35 provinces implementing PMDT, we quantified the number of MDR-TB presumptive patients tested for MDR-TB by Xpert MTB/RIF and the number of MDR-TB patients started on second-line treatment. In addition, existing reports and documents related to MDR-TB policies and guidelines in Vietnam were reviewed, supplemented with focus group discussions and in-depth interviews with MDR-TB key staff members. RESULTS: 5,668 (31.2 %) of estimated 18,165 MDR-TB presumptive cases were tested by Xpert MTB/RIF and second-line treatment was provided to 948 out of 5100 (18.7 %) of MDR-TB patients. Those tested for MDR-TB were 340/3224 (10.5 %) of TB-HIV co-infected patients and 290/2214 (13.1 %) of patients who remained sputum smear-positive after 2 and 3 months of category I TB regimen. Qualitative findings revealed the following challenges to detection and enrollment of MDR-TB in Vietnam: insufficient TB screening capacity at district hospitals where TB units were not available and poor communication and implementation of policy changes. Instructions for policy changes were not always received, and training was inconsistent between training courses. The private sector did not adequately report MDR-TB cases to the NTP. CONCLUSIONS: The proportion of MDR-TB patients diagnosed and enrolled for second-line treatment is less than 20 % of the estimated total. The low enrollment is largely due to the fact that many patients at risk are missed for MDR-TB screening. In order to detect more MDR-TB cases, Vietnam should intensify case finding of MDR-TB by a comprehensive strategy to screen for MDR-TB among new cases rather than targeting previously treated cases, in particular those with HIV co-infection and contacts of MDR-TB patients, and should engage the private sector in PMDT.

Photocatalytic degradation of p-chlorophenol by hybrid H2O2 and TiO2 in aqueous suspensions under UV irradiation.

In this study, TiO2 particles were used as photocatalysts for the degradation of aqueous p-chlorophenol (p-CP) under UV irradiation. The effect of TiO2 dose (0-3 g/L), initial p-CP concentration, H2O2 concentration (2-45 mM), solution pH (4.6-9.5), and UV light intensity on the degradation of p-CP were examined. Four oxidative degradation processes, which utilized UV alone (direct photolysis), H2O2/UV, TiO2/UV, and H2O2/TiO2/UV, were compared in a batch photoreactor with a 100-W high-pressure mercury lamp. The photodegradation of p-CP could be described by the pseudo-first-order kinetics according to the Langmuir-Hinshelwood model. Moreover, the apparent degradation rate constants increased considerably from 3.5 × 10(-)(3) min(-)(1) (direct photolysis) to 19.9 × 10(-)(3) min(-)(1) (H2O2/TiO2/UV system).

Anxiety on the internet: Describing person, provider, and organization online posts.

Anxiety is a pervasive phenomenon in contemporary society. With increased internet use in recent years, more people in the general population are seeking and providing help and participating in community online. The goal of our study was to evaluate the content of internet narratives among those who post about anxiety and determine what stakeholder groups are saying online. We used the bifurcated method; it is a multi-method (qualitative) approach with inductive, thematic analyses, and with quantification of content-related words via a computer program that crawls websites and counts the occurrences of specified terms (for cross-checking purposes). Themes of posts and webpages about anxiety were: using/reporting treatment strategies (83.3% saturation), providing help (77.8% saturation), telling personal stories (72.2% saturation), seeking help (61.1% saturation), and illustrating interpersonal impact (50% saturation). We argue that anxiety stakeholders may take part in health co-inquiry online (i.e., cooperating with others) in many of the same ways that they might collaborate in person. We recommend that clinicians query their clients about use of the internet in ways related to their anxiety (e.g., seeking information/treatment strategies, offering help to others, telling their personal stories, etc.) so that they might help them process what they experience online.

In the COVID-19 era, anxiety has increased in the general population (Shigemura, Ursano, Morganstein, Kurosawa, & Benedek, 2020; Wang et al., 2020).Daily use of the internet in the general population is extensive (Gangamma et al., 2022).Clients in therapy may use the internet in ways that interact with their clinical conditions, e.g., finding information, seeking support, providing others with information, searching/accessing services/treatment.It is vital for therapists to inquire in ways that improve their understanding of their clients' uses of the internet.

An Unidentified Infiltrative Etiology of Spinal Cord Compression: A Case Report and Literature Review.

Spinal cord compression is a neurosurgical emergency. Symptoms of this disorder are highlighted as back pain, ambulatory difficulties, and bladder/bowel incontinence. Diagnostic imaging is not indicated in many circumstances of nonspecific back pain; however, the addition of neurologic deficits in the setting of back pain justifies radiologic imaging. Various pathologies can cause constriction of the spinal cord due to the delicate nature of spinal cord anatomy. Etiologies may include trauma, neoplasms, and infections. In this report, we present an unusual case of a 31-year-old male who presented to the emergency department with a history of chronic back pain accompanied by neurological deficits, ataxia, and bladder dysfunction. Contrast-enhanced MRI imaging heightened the suspicion of a neoplastic etiology; however, neuropathology revealed a non-neoplastic nature with abnormal lymphohistiocytic infiltrate suspicious for Langerhans cell histiocytosis or infectious etiology. A second opinion was provided by Mayo Clinic Laboratories, resulting in the definitive conclusion that the mass was non-neoplastic and tested negative for SD1a and Langerhin, biomarkers used to diagnose Langerhans cell histiocytosis. This unusual non-neoplastic lesion exemplifies one of many diverse and multifaceted pathologies that can precipitate spinal cord compression. Additionally, these findings underscore the importance of considering both neoplastic and non-neoplastic causes in the differential diagnosis of spinal cord compression, thereby enhancing clinical vigilance and improving patient outcomes for underlying spinal conditions.

Two-photon autofluorescence lifetime assay of rabbit photoreceptors and retinal pigment epithelium during light-dark visual cycles in rabbit retina.

Two-photon excited fluorescence (TPEF) is a powerful technique that enables the examination of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle. Although previous intensity-based TPEF studies in non-human primates have successfully imaged several classes of retinal cells and elucidated aspects of both rod and cone photoreceptor function, fluorescence lifetime imaging (FLIM) of the retinal cells under light-dark visual cycle has yet to be fully exploited. Here we demonstrate a FLIM assay of photoreceptors and retinal pigment epithelium (RPE) that reveals key insights into retinal physiology and adaptation. We found that photoreceptor fluorescence lifetimes increase and decrease in sync with light and dark exposure, respectively. This is likely due to changes in all-trans-retinol and all-trans-retinal levels in the outer segments, mediated by phototransduction and visual cycle activity. During light exposure, RPE fluorescence lifetime was observed to increase steadily over time, as a result of all-trans-retinol accumulation during the visual cycle and decreasing metabolism caused by the lack of normal perfusion of the sample. Our system can measure the fluorescence lifetime of intrinsic retinal fluorophores on a cellular scale, revealing differences in lifetime between retinal cell classes under different conditions of light and dark exposure.

A Clinical Suspicion of Quetiapine-Induced Psychosis: A Case Report and Literature Review.

Quetiapine, a pharmacological agent within the class of atypical antipsychotics, is characterized by its efficacy in mood stabilization and its role in the modulation of serotonergic and dopaminergic pathways. Its therapeutic utility is broad, encompassing the management of acute psychotic episodes, schizophrenia, bipolar disorder, and treatment-resistant depressive states. Quetiapine's effectiveness extends to depressive disorders that do not exhibit classic psychotic features, with a side effect profile that is less burdensome than many alternative psychotropic medications. Its versatility in addressing a range of psychiatric conditions is useful in the psychopharmacological management of mood and thought disorders. However, like all drugs, quetiapine may have different effects relative to the individual. It is imperative to approach the administration of quetiapine carefully, ensuring any adverse effects are ameliorated for beneficial therapeutic outcomes. In this case report, we present a psychosis-naive 42-year-old male who developed psychotic symptoms after beginning a quetiapine regimen in order to manage major depressive disorder with suicidal ideation. Clinical suspicion of quetiapine-induced psychosis was a diagnosis considered due to symptom remission secondary to ziprasidone in the place of quetiapine. The determination of a suspected adverse drug reaction can utilize the Naranjo scale to demonstrate the likelihood of an adverse drug reaction. This patient scored a three on the Naranjo scale, indicating a possible adverse effect from quetiapine. Other potential etiologies of psychosis include medication-induced psychosis, major depressive disorder exacerbation, cocaine use/withdrawal, and brief psychotic disorder. Quetiapine-induced psychosis has not been described in the current literature, and therefore, this case report is solely based on clinical evaluation and is intended for educational purposes due to possible confounding factors and etiologies.

A non-FRET DNA reporter that changes fluorescence colour upon nuclease digestion.

Fluorescence resonance energy transfer (FRET) reporters are commonly used in the final stages of nucleic acid amplification tests to indicate the presence of nucleic acid targets, where fluorescence is restored by nucleases that cleave the FRET reporters. However, the need for dual labelling and purification during manufacturing contributes to the high cost of FRET reporters. Here we demonstrate a low-cost silver nanocluster reporter that does not rely on FRET as the on/off switching mechanism, but rather on a cluster transformation process that leads to fluorescence color change upon nuclease digestion. Notably, a 90 nm red shift in emission is observed upon reporter cleavage, a result unattainable by a simple donor-quencher FRET reporter. Electrospray ionization-mass spectrometry results suggest that the stoichiometric change of the silver nanoclusters from Ag13 (in the intact DNA host) to Ag10 (in the fragments) is probably responsible for the emission colour change observed after reporter digestion. Our results demonstrate that DNA-templated silver nanocluster probes can be versatile reporters for detecting nuclease activities and provide insights into the interactions between nucleases and metallo-DNA nanomaterials.

Preference and retention of daily and event-driven pre-exposure prophylaxis for HIV prevention: a prospective cohort in Can Tho city, Viet Nam.

OBJECTIVE: Pre-exposure prophylaxis (PrEP) was introduced in Viet Nam in 2017, but data on oral PrEP preference and effective use beyond 3 months are limited. We aimed to evaluate PrEP preferences for PrEP, factors influencing uptake, choice and effective use, as well as barriers to PrEP. METHODS: This is a prospective cohort study in Can Tho, Viet Nam. Participants who were eligible for PrEP and provided informed consent were interviewed at baseline on demographic information, willingness to pay, reasons for choosing their PrEP regimen and the anticipated difficulties in taking PrEP and followed up at 3 months, 6 months and 12 months after PrEP initiation. FINDINGS: Between May 2020 and April 2021, 926 individuals at substantial risk for HIV initiated PrEP. Of whom 673 (72.7%) choose daily PrEP and 253 (27.3%) choose event-driven (ED)-PrEP. The majority of participants were men (92.7%) and only 6.8% were women and 0.5% were transgender women. Median participant age was 24 years (IQR 20-28) and 84.7% reported as exclusively same-sex relationship. The three most common reasons for choosing daily PrEP were effectiveness (24.3%) and unplanning for sex (22.9%). Those opting for ED-PrEP also cited effectiveness (22.7%), as well as convenience (18.0%) and easier effective use (12.0%). Only 7.8% of PrEP users indicated they were unwilling to pay for PrEP and 76.4% would be willing to pay if PrEP were less than US$15 per month. The proportion of user effectively using PrEP at 12 months was 43.1% and 99.2% in daily PrEP and ED-PrEP users, respectively. CONCLUSIONS: ED-PrEP was preferred by more than a quarter of 23.5% of the participants and there was little concern about potential adverse events. High rates of effective use were reported by ED-PrEP users. Future research to inform implementation of PrEP in Viet Nam is needed to develop ways of measuring adherence to ED-PrEP more accurately and to understand and address difficulties in taking daily PrEP use.

Recent Developments in PET and SPECT Radiotracers as Radiopharmaceuticals for Hypoxia Tumors.

Hypoxia, a deficiency in the levels of oxygen, is a common feature of most solid tumors and induces many characteristics of cancer. Hypoxia is associated with metastases and strong resistance to radio- and chemotherapy, and can decrease the accuracy of cancer prognosis. Non-invasive imaging methods such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) using hypoxia-targeting radiopharmaceuticals have been used for the detection and therapy of tumor hypoxia. Nitroimidazoles are bioreducible moieties that can be selectively reduced under hypoxic conditions covalently bind to intracellular macromolecules, and are trapped within hypoxic cells and tissues. Recently, there has been a strong motivation to develop PET and SPECT radiotracers as radiopharmaceuticals containing nitroimidazole moieties for the visualization and treatment of hypoxic tumors. In this review, we summarize the development of some novel PET and SPECT radiotracers as radiopharmaceuticals containing nitroimidazoles, as well as their physicochemical properties, in vitro cellular uptake values, in vivo biodistribution, and PET/SPECT imaging results.

Visible-light-mediated synthesis of oxime esters via multicomponent reactions of aldehydes, aryl amines, and N-hydroxyphthalimide esters.

Oxime esters are useful scaffolds in many organic chemistry transformations. Herein, a novel visible-light-mediated three-component reaction for synthesis of oxime esters is reported. Aldehydes, aniline, and N-hydroxyphthalimide (NHPI) esters were used as substrates in this three-component reaction, and eosin Y was used as a crucial photocatalyst for the reaction. Wide ranges of aldehydes and NHPI esters were well tolerated in this reaction method, generating various oxime esters with high efficiency under mild reaction conditions. This visible-light-mediated methodology will be a promising approach to synthesize useful oxime esters in a single step.

Esophageal Dilation: A Cross-Sectional Analysis of Patient Information.

Objective Complications of esophageal strictures have decreased in recent years due to evolved endoscopic methods. This has primarily been through esophageal dilation. This study examines the level of readability of patient information on esophageal dilation across 40 websites found via internet search. Methods In this cross-sectional readability study, the content of the first 40 websites about "esophageal dilation" and "upper GI endoscopy" found via Google search was analyzed using WebFX (Harrisburg, PA), an established readability tool. Five readability indices, each having a unique mathematical formula, were used to analyze online material. Outputs were then scored and averaged together. Results The aggregate readability of online esophageal dilation was found to be 9.2, corresponding to a ninth-grade reading level. This average was found based on 38 unique, non-duplicated websites evaluated. Conclusions The information currently available on the internet regarding esophageal dilation is considered to be at a difficult reading level for an average patient. There remains a significant amount of development required in the domain of information accessibility to enhance the patient comprehension of invasive procedures they are poised to undergo. It is imperative to refine the articulation of complex procedures further to prepare patients for forthcoming medical procedures.