Hepatitis C Virus Antiviral Drug Resistance and Salvage Therapy Outcomes Across Australia

Background

Hepatitis C virus (HCV) infection can now be cured with well-tolerated direct-acting antiviral (DAA) therapy. However, a potential barrier to HCV elimination is the emergence of resistance-associated substitutions (RASs) that reduce the efficacy of antiviral drugs, but real-world studies assessing the clinical impact of RASs are limited. Here, an analysis of the impact of RASs on retreatment outcomes for different salvage regimens in patients nationally who failed first-line DAA therapy is reported.

Methods

We collected data from 363 Australian patients who failed first-line DAA therapy, including: age, sex, fibrosis stage, HCV genotype, NS3/NS5A/NS5B RASs, details of failed first-line regimen, subsequent salvage regimens, and treatment outcome.

Results

Of 240 patients who were initially retreated as per protocol, 210 (87.5%) achieved sustained virologic response (SVR) and 30 (12.5%) relapsed or did not respond. The SVR rate for salvage regimens that included sofosbuvir/velpatasvir/voxilaprevir was 94.3% (n = 140), sofosbuvir/velpatasvir 75.0% (n = 52), elbasvir/grazoprevir 81.6% (n = 38), and glecaprevir/pibrentasvir 84.6% (n = 13). NS5A RASs were present in 71.0% (n = 210) of patients who achieved SVR and in 66.7% (n = 30) of patients who subsequently relapsed. NS3 RASs were detected in 20 patients (20%) in the SVR group and 1 patient in the relapse group. NS5B RASs were observed in only 3 patients. Cirrhosis was a predictor of relapse after retreatment, as was previous treatment with sofosbuvir/velpatasvir.

Conclusions

In our cohort, the SVR rate for sofosbuvir/velpatasvir/voxilaprevir was higher than with other salvage regimens. The presence of NS5A, NS5B, or NS3 RASs did not appear to negatively influence retreatment outcomes.

Detecting Pathogen Exposure During the Non-symptomatic Incubation Period Using Physiological Data: Proof of Concept in Non-human Primates

Background and Objectives: Early warning of bacterial and viral infection, prior to the development of overt clinical symptoms, allows not only for improved patient care and outcomes but also enables faster implementation of public health measures (patient isolation and contact tracing). Our primary objectives in this effort are 3-fold. First, we seek to determine the upper limits of early warning detection through physiological measurements. Second, we investigate whether the detected physiological response is specific to the pathogen. Third, we explore the feasibility of extending early warning detection with wearable devices.

Research Methods: For the first objective, we developed a supervised random forest algorithm to detect pathogen exposure in the asymptomatic period prior to overt symptoms (fever). We used high-resolution physiological telemetry data (aortic blood pressure, intrathoracic pressure, electrocardiograms, and core temperature) from non-human primate animal models exposed to two viral pathogens: Ebola and Marburg (N = 20). Second, to determine reusability across different pathogens, we evaluated our algorithm against three independent physiological datasets from non-human primate models (N = 13) exposed to three different pathogens: Lassa and Nipah viruses and Y. pestis. For the third objective, we evaluated performance degradation when the algorithm was restricted to features derived from electrocardiogram (ECG) waveforms to emulate data from a non-invasive wearable device.

Results: First, our cross-validated random forest classifier provides a mean early warning of 51 ± 12 h, with an area under the receiver-operating characteristic curve (AUC) of 0.93 ± 0.01. Second, our algorithm achieved comparable performance when applied to datasets from different pathogen exposures – a mean early warning of 51 ± 14 h and AUC of 0.95 ± 0.01. Last, with a degraded feature set derived solely from ECG, we observed minimal degradation – a mean early warning of 46 ± 14 h and AUC of 0.91 ± 0.001.

Conclusion: Under controlled experimental conditions, physiological measurements can provide over 2 days of early warning with high AUC. Deviations in physiological signals following exposure to a pathogen are due to the underlying host’s immunological response and are not specific to the pathogen. Pre-symptomatic detection is strong even when features are limited to ECG-derivatives, suggesting that this approach may translate to non-invasive wearable devices.

Translation of evidence into policy to improve clinical practice: the development of an emergency department rapid response system

BACKGROUND

Undetected clinical deterioration is a major cause of high mortality events in Emergency Department (ED) patients. Yet, there is no known model to guide the recognition and response to clinical deterioration in the ED, integrating internal and external resources.

METHODS

An integrative review was firstly conducted to identify the critical components of recognising and responding to clinical deterioration in the ED. Components identified from the review were analysed by clinical experts and informed the development of an ED Clinical Emergency Response System (EDCERS).

RESULTS

Twenty four eligible studies were included in the review. Eight core components were identified: 1) vital sign monitoring; 2) track and trigger system; 3) communication plan; 4) response time; 5) emergency nurse response; 6) emergency physician response; 7) critical care team response; and 8) specialty team response. These components informed the development of the EDCERS protocol, integrating responses from staff internal and external to the ED.

CONCLUSIONS

EDCERS was based on the best available evidence and considered the cultural context of care. Future research is needed to determine the useability and impact of EDCERS on patient and health outcomes.

Sociotechnical Requirements Analysis for Clinical Systems

Objective: We explore sociotechnical requirements by examining the use of a computerized patient record system in an intensive care unit of a U.S. hospital and present two sociotechnical requirements, awareness and coordination, embedded in the users’ work.

Method: The study is based on observation during seven months of the use of a computerized patient record system in a surgical intensive care unit. During that period semi-formal interviews, informal interviews were held.

Results and Conclusions: A key step in the design of clinical systems is the development and analysis of requirements. However, traditional requirements analysis is based on a set of assumptions that break down in the highly collaborative, exception-filled clinical domain. Sociotechnical requirement analysis enabled the designers to gather a much richer description of the environment surrounding the computer system, highlighting awareness and coordination, embedded in the users’ work.

A double-blind randomized controlled trial of ibuprofen compared to placebo for uncomplicated cellulitis of the upper or lower limb

OBJECTIVES

Cellulitis is a common skin infection resulting in inflammation that may take weeks to resolve despite appropriate antibiotics. It is unclear whether the adjunctive use of nonsteroidal anti-inflammatory drugs hastens the resolution of inflammation in patients with cellulitis.

METHODS

We conducted a double-blind, randomized controlled trial comparing ibuprofen 400 mg three times daily for 5 days with identical placebo in adults with uncomplicated cellulitis of the upper or lower limb who were treated with intravenous cefazolin via an outpatient parenteral antibiotic treatment service at one of two Australian hospitals. Participants were assessed twice daily by a study nurse. The primary outcome measure was the proportion of patients with regression of inflammation 48 hours after the first effective dose of parenteral antibiotics (trial registration ANZCTR 12611000515998).

RESULTS

Fifty-one patients were enrolled; 48 had sufficient data available to be included in the modified intention-to-treat analysis. Inflammation had begun to regress at 48 hours in 20 participants (80%) in the ibuprofen group compared to 15 (65%) in the placebo group (absolute risk difference +15%; 95% confidence interval -10 to +40; p >0.05). There was no significant difference in any secondary outcome. Ibuprofen appeared safe, with no patients developing renal impairment or necrotizing fasciitis.

CONCLUSIONS

This trial demonstrated no significant benefit of adjunctive ibuprofen in adults with uncomplicated cellulitis. The trial was powered to detect a large effect, and hence it is unclear whether the 15% absolute increase in the primary end point in the ibuprofen group was attributable to chance.

Uninsurance, underinsurance, and health care utilization in Mexico by US border residents

Using data from the 2008 Cross-Border Utilization of Health Care Survey, we examined the relationship between United States (US) health insurance coverage plans and the use of health care services in Mexico by US residents of the US-Mexico border region. We found immigrants were far more likely to be uninsured than their native-born counterparts (63 vs. 27.8 %). Adults without health insurance coverage were more likely to purchase medications or visit physicians in Mexico compared to insured adults. However, adults with Medicaid coverage were more likely to visit dentists in Mexico compared to uninsured adults. Improving health care access for US residents in the southwestern border region of the country will require initiatives that target not only providing coverage to the large uninsured population but also improving access to health care services for the large underinsured population.

Real-time feedback on nonverbal clinical communication. Theoretical framework and clinician acceptance of ambient visual design

INTRODUCTION

This article is part of the focus theme of Methods of Information in Medicine on "Pervasive Intelligent Technologies for Health".

BACKGROUND

Effective nonverbal communication between patients and clinicians fosters both the delivery of empathic patient-centered care and positive patient outcomes. Although nonverbal skill training is a recognized need, few efforts to enhance patient-clinician communication provide visual feedback on nonverbal aspects of the clinical encounter.

OBJECTIVES

We describe a novel approach that uses social signal processing technology (SSP) to capture nonverbal cues in real time and to display ambient visual feedback on control and affiliation--two primary, yet distinct dimensions of interpersonal nonverbal communication. To examine the design and clinician acceptance of ambient visual feedback on nonverbal communication, we 1) formulated a model of relational communication to ground SSP and 2) conducted a formative user study using mixed methods to explore the design of visual feedback.

METHODS

Based on a model of relational communication, we reviewed interpersonal communication research to map nonverbal cues to signals of affiliation and control evidenced in patient-clinician interaction. Corresponding with our formulation of this theoretical framework, we designed ambient real-time visualizations that reflect variations of affiliation and control. To explore clinicians' acceptance of this visual feedback, we conducted a lab study using the Wizard-of-Oz technique to simulate system use with 16 healthcare professionals. We followed up with seven of those participants through interviews to iterate on the design with a revised visualization that addressed emergent design considerations.

RESULTS

Ambient visual feedback on non- verbal communication provides a theoretically grounded and acceptable way to provide clinicians with awareness of their nonverbal communication style. We provide implications for the design of such visual feedback that encourages empathic patient-centered communication and include considerations of metaphor, color, size, position, and timing of feedback.

CONCLUSIONS

Ambient visual feedback from SSP holds promise as an acceptable means for facilitating empathic patient-centered nonverbal communication.

Rural-urban differences in health services utilization in the US-Mexico border region

PURPOSE

Evaluate the association between driving distance to the US-Mexico border and rural-urban differences in the use of health services in Mexico by US border residents from Texas.

METHODS

Data for this study come from the Cross-Border Utilization of Health Care Survey, a population-based telephone survey conducted in the Texas border region in spring 2008. Driving distances to the border were estimated from the nearest border crossing station using Google Maps. Outcome measures included medication purchases, physician visits, dentist visits, and inpatient care in Mexico during the 12 months prior to the survey. A series of adjusted logit models were estimated after controlling for relevant confounding factors.

FINDINGS

The average driving distance to the nearest border crossing station among rural respondents was 4 times that of urban respondents (42.0 miles vs 10.3 miles [P < .001]). Rural respondents were more likely to be dissatisfied than urban respondents with the health care provided on the US side of the border, yet they were less likely to use health services in Mexico. Driving distance to the border largely explained the observed rural-urban differences in medication purchases from Mexico. In the case of inpatient care, however, rural respondents reported a higher utilization rate than urban respondents and this rural-urban difference became more pronounced after adjusting for the effect of driving distance to the border.

CONCLUSIONS

Dissatisfaction with US health care services in rural communities in the US-Mexico border region seems to be compounded by the lack of access to health care services in Mexico due to travel distance constraints.

Anti-vector immunity following vaccination with Venezuelan equine encephalitis replicon filovirus vaccine (113.1)

The Venezuelan equine encephalitis replicon (VRP) is the lead candidate for development as the DoD filovirus vaccine platform. One concern regarding this vaccine candidate focuses on the need to vaccinate individuals that have been pre-exposed to the VRP through previous vaccinations. To address this concern, cohorts of nonhuman primates (NHPs) were vaccinated with VRP expressing alphavirus proteins and VRP expressing Ebola virus Zaire (EBOV) glycoprotein either concurrently or sequentially. These NHPs were challenged with either 1000pfu of EBOV or 10^8 pfu of Venezuelan equine encephalitis virus (VEEV). Animals that were vaccinated with both vaccinations independent of sequence or co-administration were protected from each challenge. This data indicates that anti-vector immunity is not a concern with the VRP vaccine candidate as the product transitions into phase 1 clinical trials.

Structure and Phase Transformations in Thermoelastic Ni(1−x)TiCux) Thin Films Prepared by D.C. Magnetron Sputtering

The intermetallic compound NiTi and its copper containing variants, Ni(1−x)TiCu(x), are capableof stress induced displacive tansformations which give rise to superelasticity and shape-memory effects. Thin films of these alloys, which may find use as sensors, microactuators, or as protective surface microalloys, are of increasing interest. In this study, thin films in the Ni(1−x)TiCUx) system, ranging in thickness from 250 nm to 5 μm, were prepared with a triode-type D.C. magnetron sputtering apparatus using a ternary alloy target. Both homogeneous films and periodic multilayer structures (with interspersed Ti-rich layers) were fabricated. of particular interest were shifts in composition with respect to the target, and the structural and phase transformation characteristics of the sputtered films. These phenomena were examined using transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray microanalysis. Transformation temperatures and enthalpies were determined by differential scanning calorimetry and confirmed by 4-point D.C. resistivity measurements. The as-sputtered films were amorphousbut crystallized during annealing at 923K. Electron diffraction and XPS data suggested the presence of oxygen. Single layer film compositions were shifted to slightly lower Ti fractions which depressed the onset of the transformation sequence by ˜35K and degraded phase stability during annealing. It was possible, however, to produce periodic multilayer films which showed evidence of thermoelastic phase transformations during DSC, resistivity, and in-situ TEM experiments. These films were stable with respect to vacuum annealing at 923 K for 6 h.

Hallucinogens and Drosophila: linking serotonin receptor activation to behavior

The similarity of mode of action, behavior, and gene response between Drosophila melanogaster and mammalian systems, combined with the power of genetics, have recently made the fly an attractive system to study underlying mechanisms of drug abuse, addiction, and mental disorders. The present studies define the behavioral and molecular effects of the powerful hallucinogen lysergic acid diethylamide in Drosophila. Pharmacological activation of serotonin receptors in the fly by lysergic acid diethylamide induces behaviors not unlike those observed in mammalian systems. These include alterations in visual processing abilities, reduced locomotor activity, and altered gene expression within the brain. Many of these effects are due to activation of the same serotonin receptor subtypes that are thought to be the primary mediators of hallucinogenic drug effects in humans as well as the acute symptoms of schizophrenia.We suggest that Drosophila can be used as a genetically tractable model system to define the molecular events leading from serotonin receptor activation to behavior, possibly revealing new targets for hallucinogenic agents and for the treatment of neuropsychiatric disorders such as schizophrenia.

Sociotechnical requirements analysis for clinical systems

OBJECTIVE

We explore sociotechnical requirements by examining the use of a computerized patient record system in an intensive care unit of a U.S. hospital and present two sociotechnical requirements, awareness and coordination, embedded in the users' work.

METHOD

The study is based on observation during seven months of the use of a computerized patient record system in a surgical intensive care unit. During that period semi-formal interviews, informal interviews were held.

RESULTS AND CONCLUSIONS

A key step in the design of clinical systems is the development and analysis of requirements. However, traditional requirements analysis is based on a set of assumptions that break down in the highly collaborative, exception-filled clinical domain. Sociotechnical requirement analysis enabled the designers to gather a much richer description of the environment surrounding the computer system, highlighting awareness and coordination, embedded in the users' work.

Improved mucosal protection against Venezuelan equine encephalitis virus is induced by the molecularly defined, live-attenuated V3526 vaccine candidate

The genetically engineered, live-attenuated Venezuelan equine encephalitis (VEE) virus vaccine candidate, V3526, was evaluated as a replacement for the TC-83 virus vaccine. Protection from lethal subcutaneous or aerosol challenge was evaluated in vaccinated mice clinically and immunohistochemically. Subcutaneous administration of V3526 induced systemic and mucosal protection more efficiently than did the TC-83 vaccine. The bronchial IgA responses induced in mice by subcutaneous administration of vaccines significantly corresponded to the ability to survive aerosol challenge with virulent virus. Furthermore, V3526 delivered by aerosol induced more complete mucosal protection than either vaccine administered subcutaneously. The ability of V3526 to induce protection in mice warrants its consideration for further testing as a potential vaccine candidate for human use.

QueryCat: automatic categorization of MEDLINE queries

A searcher's inability to formulate an appropriate query can result in an overwhelming number of retrieved documents. Our approach to this problem is to use information about common types or categories of queries to (1) reformulate the user's initial query and (2) create an informative organization of the retrieved documents from the reformulated query. To achieve these goals, we first must identify which common categories or types of queries are the best abstraction of the user's specific query. In this paper, we describe a system that performs this first step of categorizing the user's query. Our system uses a two-phased approach: a lexical analysis phase, and a semantic analysis phase. An evaluation of our system demonstrates that its query categorization corresponds reasonably well to the query categorizations by medical librarians and physicians.

Multiple categorization of search results

The number of publications available to physicians and patients is increasing at an alarming rate. Although users can use tools to assist in reformulating their query, this approach is ineffective when their information needs are imprecise or many documents are relevant. The ranked list presentation of documents provides little or no information relating documents to the initial query or to each other. We argue that information overload can be reduced if documents are placed in categories that (a) relate to the initial query and (b) contain a manageable number of documents. Dynamic Categorization is a knowledge-based approach that satisfies (a), however the number of documents in a category may still be large. We demonstrate that using the same approach to re-categorize the documents in large categories reduces the number of documents in the subcategory, and maintains a clear relationship to the initial query.

The usefulness of dynamically categorizing search results

OBJECTIVE

The authors' goal was to determine whether dynamic categorization, a new technique for organizing search results, is more useful than the two existing organizational techniques: relevance ranking and clustering. They define a useful tool as one that helps users learn about the kinds of information that pertain to their query, find answers to their questions efficiently and easily, and feel satisfied with their search experience.

DESIGN

Fifteen patients with breast cancer and their family members completed query-related tasks using all three tools. The authors measured the time it took the subjects to accomplish their tasks, the number of answers to the query that the subjects found in four minutes, and the number of new answers that they could recall at the end of the study. Subjects also completed a user-satisfaction questionnaire.

RESULTS

The results showed that patients with breast cancer and their family members could find significantly (P: < 0.05) more answers in a fixed amount of time and were significantly (P: < 0.05) more satisfied with their search experience when they used the dynamic categorization tool than when they used either the cluster tool or the ranking tool. Subjects indicated that the dynamic categorization tool provided an organization of search results that was more clear, easy to use, accurate, precise, and helpful than those of the other tools.

CONCLUSION

The experiments indicate that dynamic categorization is an effective and useful approach for organizing search results. Tools that use this technique will help patients and their families gain quick and easy access to important medical information.

A microsatellite within the MUC1 locus at 1q21 is altered in the neoplastic cells of breast cancer patients

Paired DNA samples from the neoplastic and nonneoplastic cells of 118 patients with the sporadic, nonfamilial form of breast cancer were analyzed for evidence of genetic alteration at a polymorphic microsatellite mapped to intron 6 within the MUC1 gene at 1q21. Two other microsatellite loci, D1S104 and APO-A2, which also map to 1q21, were analyzed as well. The frequency of alteration at the microsatellite within the MUC1 locus was significantly higher than D1S104 or APO-A2 (P < 0.001). Analysis by Southern blotting of the VNTR region of the MUC1 gene revealed an amplification of one allele in 34 of 54 informative cases (63%). There was no significant association between these alterations and alterations of the microsatellite within the same locus, suggesting independent mechanisms were responsible for the genetic changes. Microsatellite loci D17S579 at 17q21, the site of the BRCA1 gene, and D18S34 at 18q21-qter, the deleted in colorectal cancer locus, were also analyzed by PCR. Alterations at D17S579 and D18S34 were detected in 18.8% and 6.2% of patients, respectively (P < 0.001, and P < 0.1 relative to the frequency of alteration at D1S104 or APO-A2). A previously described polymorphism of hMSH2 was altered in 16.4% of cases.

Venezuelan equine encephalitis virus vaccines induce mucosal IgA responses and protection from airborne infection in BALB/c, but not C3H/HeN mice

Immunization with either a live-attenuated (TC-83) or formalin-inactivated (C-84) vaccine for Venezuelan equine encephalitis (VEE) virus protected BALB/c mice from lethal VEE infection acquired subcutaneously or by aerosol. While vaccinated C3H/HeN mice were also protected from parenteral infection, neither vaccine protected these mice from an aerosol infection. The apparent vaccine failures in C3H/HeN mice could not be attributed to deficiencies in virus-neutralizing antibodies in serum, as these responses were typically of equal or higher titer than those observed in protected BALB/c mice before challenge. IgG subclass analysis offered no facile explanation: profiles of IgG2 alpha dominance were observed in C3H/HeN mice given either vaccine and in BALB/c mice given the live-attenuated vaccine, whereas BALB/c antibody responses shifted toward IgGl dominance after immunization with the killed C-84 vaccine. Data from immunized congenic mice showed that the H-2 genes from the C3H/He mice were not singularly responsible for the inability of these mice to resist aerosol infection with VEE virus. VEE virus-specific IgA responses were detected more frequently in respiratory and vaginal secretions obtained from the protected BALB/c mice.

Dynamic organization of search results using the UMLS

When people search the medical literature, they often are overwhelmed by the large number of documents retrieved. Many systems try to solve this problem by helping the user formulate a more specific search strategy. However, when users do not have a more specific question, they need tools to help them explore and understand the results, rather than to eliminate a portion of those results. This paper describes an approach that addresses this need by automatically grouping the results of a broad search into meaningful categories based on the user's query. This approach combines the main benefit of clustering techniques with the main benefit of classification techniques by taking advantage of the domain knowledge present in the UMLS. I present a preliminary evaluation that demonstrates that a categorization produced by this approach corresponds reasonably well to a physician's categorization.

A web-based architecture for a medical vocabulary server

For health care providers to share computing resources and medical application programs across different sites, those applications must share a common medical vocabulary. To construct a common vocabulary, researchers must have an architecture that supports collaborative, networked development. In this paper, we present a web-based server architecture for the collaborative development of a medical vocabulary: a system that provides network services in support of medical applications that need a common, controlled medical terminology. The server supports vocabulary browsing and editing and can respond to direct programmatic queries about vocabulary terms. We have tested the programmatic query-response capability of the vocabulary server with a medical application that determines when patients who have HIV infection may be eligible for certain clinical trials. Our emphasis in this paper is not on the content of the vocabulary, but rather on the communication protocol and the tools that enable collaborative improvement of the vocabulary by any network-connected user.

Surgical planning using three-dimensional imaging and computer modeling

The acquisition, processing, and use of three-dimensional (3D) imaging provide new insights into normal and abnormal craniofacial anatomy. In this article, characteristics of CT and MRI scanning are reviewed along with the methods used to delineate tissues and produce 3D patient displays, including contouring, shaded surface, and volumetric processing. The use of 3D model fabrication for surgical planning is discussed with examples of the production of a custom CT-based auricle model and the use of rapid prototyping technology to create models for custom alloplastic implant surgery. The review concludes with some speculation about the future of 3D medical imaging as it will influence surgical training and practice over the coming decades.

Regional localization of the intestinal mucin gene MUC3 to chromosome 7q22

The gene MUC3 which codes for a mucin expressed in intestine (Gum et al. 1990) has previously been mapped, using somatic cell hybrids, to chromosome 7. We describe here the regional localization of MUC3 to chromosome 7q22 by in situ hybridization. Preliminary linkage analysis using CEPH (Centre d'Etude du Polymorphisme Humain) families supports this assignment and places MUC3 in the same linkage group as COL1A2 and CFTR.