Twinkle-Catalyzed Toehold-Mediated DNA Strand Displacement Reaction.

Strand exchange between homologous nucleic acid sequences is the basis for cellular DNA repair, recombination, and genome editing technologies. Specialized enzymes catalyze cellular strand exchange; however, the reaction occurs spontaneously when a single-stranded DNA toehold can dock the invader strand on the target DNA to initiate strand exchange through branch migration. Due to its precise response, the spontaneous toehold-mediated strand displacement (TMSD) reaction is widely employed in DNA nanotechnology. However, enzyme-free TMSD suffers from slow rates, resulting in slow response times. Here, we show that human mitochondrial DNA helicase Twinkle can accelerate TMSD up to 6000-fold. Mechanistic studies indicate that Twinkle accelerates TMSD by catalyzing the docking step, which typically limits spontaneous reactions. The catalysis occurs without ATP, and Twinkle-catalyzed TMSD rates remain sensitive to base-pair mismatches. The simple catalysis, tunability, and speed improvement of the catalyzed TMSD can be leveraged in nanotechnology, requiring sensitive detection and faster response times.

Management and referral patterns for new-onset chronic cough in primary care patients.

Background: The diagnosis and management of chronic cough in primary care is challenging despite it being one of the most common chronic conditions. Objective: Clinical characterization of patients with new-onset chronic cough in the primary care setting. Methods: This was a retrospective study of adult patients (ages ≥ 18 years) with at least three visits with primary care providers (PCP) for new-onset cough, with at least 8 weeks between the first and third visits, within a tertiary-care center and affiliated clinics between January 1, 2010, and January 1, 2019 (N = 174). We calculated the frequency of primary care visits, diagnostic testing, specialist referrals, and prescribed medications up to 18 months after the third visit with a PCP for cough. Results: Of 174 patients who met the criteria of new-onset chronic cough, >50% had four or more primary care visits related to cough. Despite that, 91 (52.3%) did not receive a referral to a specialist, and 41 (23.5%) did not receive an order for a chest radiograph during the evaluation of the chronic cough. Antibiotics and systemic corticosteroids were prescribed to 106 (61%) and 63 (36%) of the patients, respectively, and 20% were prescribed opiates. No patients were prescribed central-neuromodulating agents, and angiotensin-converting enzyme inhibitors were discontinued in 48% of the patients who were taking them (12/25). Conclusion: We found considerable heterogeneity and discrepancies with clinical guideline recommendations in patients who presented with new chronic cough. There is a substantial unmet need to study chronic cough in the primary care setting to inform important stakeholders.

Quality of life is lower in adults labeled with childhood-onset food allergy than in those with adult-onset food allergy.

BACKGROUND: Immunoglobulin E-mediated food allergy (FA) affects children and adults with variable age of onset. Phenotype and quality of life (QoL) differences between childhood-onset FA (COFA) and adult-onset FA (AOFA) are not known. OBJECTIVE: To identify phenotypic and QoL differences between AOFA and COFA. METHODS: A cross-sectional study of adults (≥18 years old) seen at Northwestern Memorial HealthCare clinics between 2002 and 2017 with an International Classification of Diseases ninth and tenth revision diagnosis of FA. Subjects completed a FA history survey and a FA QoL questionnaire. FA characteristics and QoL scores were compared between groups. RESULTS: Among 294 consented subjects, 202 had a clinical history consistent with labeled immunoglobulin E-mediated FA. The onset of FA symptoms occurred before age 18 years (COFA) in 80 subjects and after age 18 years in 122 (AOFA) subjects. Shellfish reactions were most common in AOFA-labeled subjects (28%), whereas tree nut reactions were the most common in COFA-labeled subjects (55%) compared with other triggers. Hives (68% vs 52%, P = .03), facial swelling (69% vs 50%, P = .009), wheezing (56% vs 29%, P < .001), and vomiting (41% vs 22%, P = .005) were more often observed in COFA compared with AOFA. Total QoL was significantly reduced in COFA compared with AOFA (3.6 vs 3.0, P = .003) along with specific domains related to the following: allergen avoidance and dietary restriction (3.7 vs 3.1, P = .006), emotional impact (3.9 vs 3.2, P = .003), and risk of accidental exposure (3.6 vs 2.8, P = .001). CONCLUSION: There are differences in specific food triggers and symptoms in adult-onset and childhood-onset labeled FA. Adults labeled with childhood-onset FA have reduced QoL.

COVID-19 vaccine-related presumed allergic reactions and second dose administration by using a two-step graded protocol.

Background: Acute allergic reactions to messenger RNA (mRNA) vaccines are rare but may limit public health immunization efforts. Objectives: To characterize suspected allergic reactions to the first dose of coronavirus disease 2019 (COVID-19) mRNA vaccine and to assess the safety and utility of a two-step graded-dose protocol for the second dose of the Pfizer-BioNTech vaccine in patients with a history of low suspicion of anaphylaxis to their first dose. Methods: This was a retrospective evaluation of referrals to the allergy and immunology clinic for a presumed allergic reaction to the first dose of the COVID-19 mRNA vaccine (Pfizer-BioNTech or Moderna) between December 17, 2020, and February 28, 2021. Recommendations for the second dose and outcomes were evaluated by trained board-certified allergists. Results: Seventy-seven patients presented with a Pfizer-BioNTech reaction (56 [72.7%]) or with a Moderna reaction (21 [27.3%]). Most patients (69.7%) had symptom onset within 4 hours. Most commonly reported symptoms were cutaneous (51.9%), cardiovascular (48.1%), and respiratory (33.8%) symptoms. Recommendations included to proceed with the single dose (70.1%), two-step graded dose (19.5%), or deferral (10.4%). Twelve of 15 patients completed the second dose with a graded-dose protocol. Of these patients, five reported at least one or more similar symptoms as experienced with their first dose. Conclusion: Of the patients with presumed allergic reactions to their first dose of COVID-19 mRNA vaccine, most were able to safely receive the second dose. For those with a low suspicion of anaphylaxis, the two-step graded protocol with the Pfizer-BioNTech vaccine was well tolerated. A graded-dose protocol could be an effective strategy for second-dose vaccination in those who may otherwise defer the second dose.

Impact of type 2 targeting biologics on acute exacerbations of chronic rhinosinusitis.

Background: Acute exacerbations of chronic rhinosinusitis (AECRS) are associated with significant morbidity and decreased quality of life. There are sparse data assessing the real-world impact of biologics on AECRS. Objectives: We sought to determine the impact of type 2-targeting biologics on the frequency of medication use for AECRS episodes. Methods: Antibiotic and/or systemic corticosteroid courses for AECRS were identified in a retrospective study from November 2015 to February 2020, at a single academic health system. The estimated yearly rates for antibiotic and corticosteroid courses were evaluated before and after initiation of type 2 biologics. Results: One-hundred and sixty-five patients with chronic rhinosinusitis (CRS) had received either omalizumab (n = 12), mepolizumab (n = 42), benralizumab (n = 44), dupilumab (n = 61), or reslizumab (n = 6). Seventy percent had CRS with nasal polyps, and 30% had CRS without nasal polyps. All the patients had asthma. When all the biologics were combined, the estimated yearly rate for antibiotics for AECRS decreased from 1.34 (95% confidence interval [CI], 1.12-1.59) to 0.68 (95% CI, 0.52-0.88) with biologic use (49% reduction, p < 0.001). Those with frequent AECRS (three or more courses of antibiotics in the 1 year before biologic use) had a larger degree of reduction, with an estimated yearly rate of 4.15 (95% CI, 3.79-4.55) to 1.58 (95% CI, 1.06-2.35) with biologic use (n = 27; 62% reduction; p < 0.001). Within the total cohort, the estimated yearly rate for systemic corticosteroids for AECRS decreased from 1.69 (95% CI, 1.42-2.02) to 0.68 (95% CI, 0.53-0.88) with biologic use (60% reduction; p < 0.001). Conclusion: Type 2-targeting biologics reduced medication use for AECRS. This suggested that biologics may be a therapeutic option for patients with frequent AECRS.

Prevalence and characterization of asthma in hospitalized and nonhospitalized patients with COVID-19.

BACKGROUND: The Centers for Disease Control and Prevention advises that patients with moderate to severe asthma belong to a high-risk group that is susceptible to severe coronavirus disease 2019 (COVID-19). However, the association between asthma and COVID-19 has not been well-established. OBJECTIVE: The primary objective was to determine the prevalence of asthma among patients with COVID-19 in a major US health system. We assessed the clinical characteristics and comorbidities in asthmatic and nonasthmatic patients with COVID-19. We also determined the risk of hospitalization associated with asthma and/or inhaled corticosteroid use. METHODS: Medical records of patients with COVID-19 were searched by a computer algorithm (March 1 to April 15, 2020), and chart review was used to validate the diagnosis of asthma and medications prescribed for asthma. All patients had PCR-confirmed COVID-19. Demographic and clinical features were characterized. Regression models were used to assess the associations between asthma and corticosteroid use and the risk of COVID-19-related hospitalization. RESULTS: Of 1526 patients identified with COVID-19, 220 (14%) were classified as having asthma. Asthma was not associated with an increased risk of hospitalization (relative risk, 0.96; 95% CI, 0.77-1.19) after adjusting for age, sex, and comorbidities. The ongoing use of inhaled corticosteroids did not increase the risk of hospitalization in a similar adjusted model (relative risk, 1.39; 95% CI, 0.90-2.15). CONCLUSIONS: Despite a substantial prevalence of asthma in our COVID-19 cohort, asthma was not associated with an increased risk of hospitalization. Similarly, the use of inhaled corticosteroids with or without systemic corticosteroids was not associated with COVID-19-related hospitalization.

Generalized Anxiety Disorder.

Generalized anxiety disorder (GAD) is a common and disabling illness that is often underdiagnosed and undertreated. Patients with GAD are at increased risk for suicide as well as cardiovascular-related events and death. Most patients can be diagnosed and managed by primary care physicians. Symptoms include chronic, pervasive anxiety and worry accompanied by nonspecific physical and psychological symptoms (restlessness, fatigue, difficulty concentrating, irritability, muscle tension, or sleep disturbances). Effective treatments include psychotherapy (often cognitive behavioral therapy) and pharmacotherapy, such as selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors.

Structural basis for processivity and antiviral drug toxicity in human mitochondrial DNA replicase.

The human DNA polymerase gamma (Pol γ) is responsible for DNA replication in mitochondria. Pol γ is particularly susceptible to inhibition by dideoxynucleoside-based inhibitors designed to fight viral infection. Here, we report crystal structures of the replicating Pol γ-DNA complex bound to either substrate or zalcitabine, an inhibitor used for HIV reverse transcriptase. The structures reveal that zalcitabine binds to the Pol γ active site almost identically to the substrate dCTP, providing a structural basis for Pol γ-mediated drug toxicity. When compared to the apo form, Pol γ undergoes intra- and inter-subunit conformational changes upon formation of the ternary complex with primer/template DNA and substrate. We also find that the accessory subunit Pol γB, which lacks intrinsic enzymatic activity and does not contact the primer/template DNA directly, serves as an allosteric regulator of holoenzyme activities. The structures presented here suggest a mechanism for processivity of the holoenzyme and provide a model for understanding the deleterious effects of Pol γ mutations in human disease. Crystal structures of the mitochondrial DNA polymerase, Pol γ, in complex with substrate or antiviral inhibitor zalcitabine provide a basis for understanding Pol γ-mediated drug toxicity.

Skin testing in allergy.

Skin tests are used in addition to a directed history and physical examination to exclude or confirm immunoglobulin E (IgE) mediated diseases, such as allergic rhinitis, asthma, and anaphylaxis, to aeroallergens, foods, insect venoms, and certain drugs. There are two types of skin testing used in clinical practice: percutaneous testing (prick or puncture) and intracutaneous testing (intradermal). Prick testing involves introducing a needle into the upper layers of the skin through a drop of allergen extract that has been placed on the skin and gently lifting the epidermis up. Various devices are available for prick testing. Intracutaneous (intradermal) testing involves injecting a small amount of allergen into the dermis. The release of preformed histamine from mast cells causes increased vascular permeability via smooth-muscle contraction and development of a wheal; inflammatory mediators initiate a neural reflex, which causes vasodilatation, which leads to erythema (the flare). Prick testing methods are the initial technique for detecting the presence of IgE. These may correlate better with clinical sensitivity and are more specific but less sensitive than intradermal testing. Sites of skin testing include the back and the volar aspect of the arm. By skin testing on the arm, the patient can witness the emergence and often sense the pruritus of the skin test reaction. Because more patients are sensitized (have IgE antibodies and positive skin test reactions) than have corresponding symptoms, the diagnosis of allergy can be made only by correlating skin testing results with the presence of clinical symptoms.

Allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) occurs in patients with asthma or cystic fibrosis, and results in pulmonary infiltrates, tenacious mucus plugs that harbor hyphae of Aspergillus fumigatus, elevations of total serum immunoglobulin E concentration and peripheral blood and sputum eosinophilia. Bronchiectasis is an irreversible complication of ABPA. The key to early diagnosis is to consider ABPA in anyone with asthma or cystic fibrosis and with a positive skin test result for Aspergillus, and/or recurrent infiltrates on radiographs. The differential diagnosis for ABPA in patients with asthma includes diseases in which there is an overlap of asthma, peripheral blood eosinophilia, and radiographic infiltrates. Examples include chronic eosinophilic pneumonia, Churg-Strauss syndrome, drug-induced pulmonary infiltrates, infection with a parasite, asthma with atelectasis, and lymphoma. Mucus plugging that causes a "tree in bud" pattern on computerized tomography examination of the lungs may be from ABPA or other conditions, such as nontuberculous (atypical) mycobacteria (Mycobacteria avium-Mycobacteria intracellulare complex). Prednisone is indicated to clear pulmonary infiltrates, and a usual course is for 3 months. Itraconazole and voriconazole are adjunctive, and drug-drug interactions must be considered because azoles decrease elimination of various medications. Although not familial in most patients, presentation of Aspergillus fumigatus f1 (Asp f1) antigen is restricted to specific major histocompatibility complex (MHC) class II molecules, Human Leukocyte Antigen-DR2 (HLA-DR2), and HLA-DR5. There is an increased number of CD4+ T-helper type 2 lymphocytes in bronchoalveolar lavage, and A. fumigatus can serve as a growth factor of eosinophils potentiating the effects of interleukin (IL) 3, IL-5, and Granulocyte-colony stimulating factor (G-CSF). Eosinophils interact directly with A. fumigatus spores and generate extracellular traps, which can injure the bronchial epithelium.

Hereditary and acquired angioedema.

Hereditary angioedema (HAE) is an autosomal dominant disorder defined by a deficiency of functional C1 esterase inhibitor (C1-INH). Acquired angioedema is due to either consumption (type 1) or inactivation (type 2) of CI-INH. Both HAE and acquired angioedema can be life-threatening. Of the three types of HAE, type 1 is most common, occurring in approximately 85% of patients and characterized by decreased production of C1-INH, which results in reduced functional activity to 5-40% of normal. Type 2 occurs in 15% of cases; C1-INH is detectable in normal or elevated quantities but is dysfunctional. Also, HAE with normal CI-INH (previously called type 3 HAE) is rare and characterized by normal complement studies. Specific genetic mutations have been linked to factor XII, angiopoietin-1, and plasminogen gene. Patients with unknown mutations are classified as unknown. The screening test for types 1 and 2 is complement component C4, which is low to absent at times of angioedema and during quiescent periods. A useful test to differentiate HAE from acquired angioedema is C1q protein, which is normal in HAE and low in acquired angioedema. The management of HAE has been transformed with the advent of disease-specific therapies. On-demand therapy options include plasma and recombinant C1-INH for intravenous infusion; ecallantide, an inhibitor of kallikrein; and icatibant, a bradykinin ß2 receptor antagonist, both administered subcutaneously. For long-term prophylaxis, intravenous or subcutaneous C1-INH enzyme replacement and lanadelumab, a monoclonal antibody against kallikrein that is administered subcutaneously, are effective agents.

Homologous DNA strand exchange activity of the human mitochondrial DNA helicase TWINKLE.

A crucial component of the human mitochondrial DNA replisome is the ring-shaped helicase TWINKLE-a phage T7-gene 4-like protein expressed in the nucleus and localized in the human mitochondria. Our previous studies showed that despite being a helicase, TWINKLE has unique DNA annealing activity. At the time, the implications of DNA annealing by TWINKLE were unclear. Herein, we report that TWINKLE uses DNA annealing function to actively catalyze strand-exchange reaction between the unwinding substrate and a homologous single-stranded DNA. Using various biochemical experiments, we demonstrate that the mechanism of strand-exchange involves active coupling of unwinding and annealing reactions by the TWINKLE. Unlike strand-annealing, the strand-exchange reaction requires nucleotide hydrolysis and greatly stimulated by short region of homology between the recombining DNA strands that promote joint molecule formation to initiate strand-exchange. Furthermore, we show that TWINKLE catalyzes branch migration by resolving homologous four-way junction DNA. These four DNA modifying activities of TWINKLE: strand-separation, strand-annealing, strand-exchange and branch migration suggest a dual role of TWINKLE in mitochondrial DNA maintenance. In addition to playing a major role in fork progression during leading strand DNA synthesis, we propose that TWINKLE is involved in recombinational repair of the human mitochondrial DNA.

ATP-induced helicase slippage reveals highly coordinated subunits.

Helicases are vital enzymes that carry out strand separation of duplex nucleic acids during replication, repair and recombination. Bacteriophage T7 gene product 4 is a model hexameric helicase that has been observed to use dTTP, but not ATP, to unwind double-stranded (ds)DNA as it translocates from 5' to 3' along single-stranded (ss)DNA. Whether and how different subunits of the helicase coordinate their chemo-mechanical activities and DNA binding during translocation is still under debate. Here we address this question using a single-molecule approach to monitor helicase unwinding. We found that T7 helicase does in fact unwind dsDNA in the presence of ATP and that the unwinding rate is even faster than that with dTTP. However, unwinding traces showed a remarkable sawtooth pattern where processive unwinding was repeatedly interrupted by sudden slippage events, ultimately preventing unwinding over a substantial distance. This behaviour was not observed with dTTP alone and was greatly reduced when ATP solution was supplemented with a small amount of dTTP. These findings presented an opportunity to use nucleotide mixtures to investigate helicase subunit coordination. We found that T7 helicase binds and hydrolyses ATP and dTTP by competitive kinetics such that the unwinding rate is dictated simply by their respective maximum rates V(max), Michaelis constants K(M) and concentrations. In contrast, processivity does not follow a simple competitive behaviour and shows a cooperative dependence on nucleotide concentrations. This does not agree with an uncoordinated mechanism where each subunit functions independently, but supports a model where nearly all subunits coordinate their chemo-mechanical activities and DNA binding. Our data indicate that only one subunit at a time can accept a nucleotide while other subunits are nucleotide-ligated and thus they interact with the DNA to ensure processivity. Such subunit coordination may be general to many ring-shaped helicases and reveals a potential mechanism for regulation of DNA unwinding during replication.

Coordinating DNA replication by means of priming loop and differential synthesis rate.

Genomic DNA is replicated by two DNA polymerase molecules, one of which works in close association with the helicase to copy the leading-strand template in a continuous manner while the second copies the already unwound lagging-strand template in a discontinuous manner through the synthesis of Okazaki fragments. Considering that the lagging-strand polymerase has to recycle after the completion of every Okazaki fragment through the slow steps of primer synthesis and hand-off to the polymerase, it is not understood how the two strands are synthesized with the same net rate. Here we show, using the T7 replication proteins, that RNA primers are made 'on the fly' during ongoing DNA synthesis and that the leading-strand T7 replisome does not pause during primer synthesis, contrary to previous reports. Instead, the leading-strand polymerase remains limited by the speed of the helicase; it therefore synthesizes DNA more slowly than the lagging-strand polymerase. We show that the primase-helicase T7 gp4 maintains contact with the priming sequence during ongoing DNA synthesis; the nascent lagging-strand template therefore organizes into a priming loop that keeps the primer in physical proximity to the replication complex. Our findings provide three synergistic mechanisms of coordination: first, primers are made concomitantly with DNA synthesis; second, the priming loop ensures efficient primer use and hand-off to the polymerase; and third, the lagging-strand polymerase copies DNA faster, which allows it to keep up with leading-strand DNA synthesis overall.

Hematologic cancer diagnosis and classification using machine and deep learning: State-of-the-art techniques and emerging research directives.

Hematology is the study of diagnosis and treatment options for blood diseases, including cancer. Cancer is considered one of the deadliest diseases across all age categories. Diagnosing such a deadly disease at the initial stage is essential to cure the disease. Hematologists and pathologists rely on microscopic evaluation of blood or bone marrow smear images to diagnose blood-related ailments. The abundance of overlapping cells, cells of varying densities among platelets, non-illumination levels, and the amount of red and white blood cells make it more difficult to diagnose illness using blood cell images. Pathologists are required to put more effort into the traditional, time-consuming system. Nowadays, it becomes possible with machine learning and deep learning techniques, to automate the diagnostic processes, categorize microscopic blood cells, and improve the accuracy of the procedure and its speed as the models developed using these methods may guide an assisting tool. In this article, we have acquired, analyzed, scrutinized, and finally selected around 57 research papers from various machine learning and deep learning methodologies that have been employed in the diagnosis of leukemia and its classification over the past 20 years, which have been published between the years 2003 and 2023 by PubMed, IEEE, Science Direct, Google Scholar and other pertinent sources. Our primary emphasis is on evaluating the advantages and limitations of analogous research endeavors to provide a concise and valuable research directive that can be of significant utility to fellow researchers in the field.

Cutting-edge Advances in Nanocarrier-Facilitated Topical Drug Delivery Systems for Targeted Skin Cancer Therapy: A Comprehensive Review.

Skin cancer is one of the most common and complex types of the disease, resulting in a high mortality rate worldwide. Skin cancer can be treated with chemotherapy, surgery, radiotherapy, etc. In most cases, a patient's condition and the type of skin cancer determine the recommended treatment options. As a result of poor penetration of the drug into stratum corneum or lesions, low efficacy, and higher concentrations of active pharmaceutical ingredients required to achieve a therapeutic effect, the efficacy of skin cancer therapy has been limited. The high dose requirement, as well as poor bioavailability at the site of action, causes skin inflammation, which greatly hinders drug absorption. This review mainly focuses on research on nanocarriers for sitespecific and controlled delivery of therapeutics for skin cancer treatment. The information related to various nanocarriers systems for skin cancer will be illustrated. This also focused on patents, clinical trials, and research carried out in the field of liposomes, niosomes, ethosomes, nanoparticles, microemulsion, nanoemulsions, gels, nanogels, hydrogels, dendrimers, and nanofibers for treating skin cancer. Nanotechnology-based therapy has shown great promise in controlling skin cancer and can be used to deliver drugs more effectively.

Evaluating a promising methylcellulose hydrogel for enhanced diabetic foot ulcer therapy through comprehensive preclinical studies.

The present research focuses on formulating and evaluating hydrogels modified with crosslinking agents using methylcellulose to treat diabetic foot ulcers (DFU). Methylcellulose hydrogels are prepared and characterized for their crosslinking capacity through FTIR and degradation studies. The optimized hydrogel is further assessed for viscosity, gel strength, contact angle, in-vitro biodegradation, water-vapor transmission rate, anti-bacterial activity, and in-vivo efficacy. The results demonstrate that the developed hydrogel exhibits promising properties for DFU treatment, including increased wound healing percentage, improved ulcer morphology, reduced levels of proinflammatory cytokines, and enhanced tissue characteristics. These findings suggest that the novel hydrogel composition could serve as a viable alternative to existing dressings for DFU management.

Electrospun nanofibers as advanced wound dressing materials: comparative analysis of single-layered and multilayered nanofibers containing polycaprolactone, methylcellulose, and polyvinyl alcohol.

The dressing materials that provide surface protection, bacteriostatic activities, and tissue regeneration are important for the treatment and management of complex wounds. This study aimed to evaluate the wound-healing properties of electrospun nanofibers containing a blend of methylcellulose (MC) and polyvinyl alcohol (PVA). The nanofibers were tested in single-layered (S-NFs) and multilayered (M-NFs) forms (PCL/MC-PVA/PCL). In vitro scratch assay using L929 cells and in vivo experiments on Wistar rats were conducted. The results showed that both S-NFs and M-NFs significantly accelerated wound closure by promoting cell migration. M-NFs demonstrated superior wound healing activity compared to S-NFs. Additionally, M-NFs exhibited faster skin epithelization compared to S-NFs. Histopathological evaluation confirmed the absence of irritation or lesions on the healed wound surface. Overall, the study concluded that these polymeric nanofibers have the potential to be used as self-wound healing dressings. They are safe, non-toxic, biodegradable, and biocompatible.

Patient-reported experiences with refractory or unexplained chronic cough: a qualitative analysis.

BACKGROUND: Chronic cough, defined as a cough lasting 8 or more weeks, affects up to 10% of adults. Refractory chronic cough (RCC) is a cough that is uncontrolled despite comprehensive investigation and treatment of comorbid conditions while unexplained chronic cough (UCC) is a cough with no identifiable cause despite extensive evaluation of comorbid conditions. RCC and UCC are often poorly controlled. Understanding individuals' lived experience of the symptoms and impacts of these conditions may guide therapeutic strategies. OBJECTIVES: The primary objectives of this study were to assess respondents' perceptions of the key symptoms of RCC and UCC and the impacts of RCC and UCC and their symptoms on well-being, health-related quality of life, work productivity, and social relationships. DESIGN: Qualitative study. METHODS: This study enrolled 30 adults with physician-diagnosed RCC or UCC. Two trained qualitative researchers conducted individual, in-depth telephone interviews using a semi-structured interview guide. Interviews were audio-recorded, transcribed, coded, and systematically analyzed to identify content themes. RESULTS: A total of 15 respondents with RCC and 15 with UCC were included in the study. Many respondents had RCC or UCC for a long duration (median 9 years, range: 0-24). Half of the respondents reported having a coughing episode at least once daily. Only 40% of respondents reported that medication had improved their symptoms. In over half of the respondents, RCC or UCC hindered communication, caused embarrassment, frustration, and worry, and lowered quality of life. Perceptions of meaningful treatment benefits in RCC or UCC varied widely across respondents. CONCLUSION: RCC and UCC remained poorly managed in many individuals and were associated with a wide range of symptoms and cough triggers that hindered daily activities and reduced emotional well-being. Understanding individuals' lived experiences may inform the development of RCC and UCC therapeutic strategies.

Patient-reported experiences with refractory or unexplained chronic cough: a qualitative analysisChronic cough, particularly refractory and unexplained chronic cough, remain poorly managed in many individuals and are associated with a wide range of symptoms and cough triggers that hinder daily activities and reduce emotional well-being. Currently there are no US Food and Drug Administration-approved treatments for refractory or unexplained chronic cough. Understanding the experience and treatment preferences of individuals with these conditions may help inform the development of new therapies and clarify the potential impact of such therapies on the lives of individuals with chronic cough. Using in-depth interviews, the present study comprehensively evaluated individuals' experience with refractory or unexplained chronic cough and treatment priorities, a research area that has not been well-studied. This study detailed broad-ranging physical, behavioral, and emotional impacts of chronic cough, which hindered individuals' social well-being.