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1.
Work ; 74(4): 1199-1213, 2023.
Article in English | MEDLINE | ID: mdl-36938769

ABSTRACT

BACKGROUND: Post-exertional malaise (PEM) is the hallmark symptom of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) yet its diverse manifestations make it difficult to recognize. Brief instruments for detecting PEM are critical for clinical and scientific progress. OBJECTIVE: To develop a clinical prediction rule for PEM. METHOD: 49 ME/CFS and 10 healthy, sedentary subjects recruited from the community completed two maximal cardiopulmonary exercise tests (CPETs) separated by 24 hours. At five different times, subjects reported symptoms which were then classified into 19 categories. The frequency of symptom reports between groups at each time point was compared using Fisher's exact test. Receiver operating characteristics (ROC) analysis with area under the curve calculation was used to determine the number of different types of symptom reports that were sufficient to differentiate between ME/CFS and sedentary groups. The optimal number of symptoms was determined where sensitivity and specificity of the types of symptom reports were balanced. RESULTS: At all timepoints, a maximum of two symptoms was optimal to determine differences between groups. Only one symptom was necessary to optimally differentiate between groups at one week following the second CPET. Fatigue, cognitive dysfunction, lack of positive feelings/mood and decrease in function were consistent predictors of ME/CFS group membership across timepoints. CONCLUSION: Inquiring about post-exertional cognitive dysfunction, decline in function, and lack of positive feelings/mood may help identify PEM quickly and accurately. These findings should be validated with a larger sample of patients.


Subject(s)
Fatigue Syndrome, Chronic , Humans , Fatigue Syndrome, Chronic/complications , Fatigue Syndrome, Chronic/diagnosis , Emotions , Exercise Test , Affect
2.
J Palliat Med ; 26(6): 776-783, 2023 06.
Article in English | MEDLINE | ID: mdl-36577037

ABSTRACT

Background: End-stage liver disease (ESLD) patients carry heavy symptom burdens and risk receiving aggressive and sometimes unwanted care at end of life. Palliative care (PC), which aims to alleviate symptoms and facilitate goal-concordant care in serious illness, may offer substantial benefits for ESLD patients but is not widely provided. Objectives: To assess the impact of PC integrated within hepatology (PCIH) services on health care utilization, advance care planning (ACP), and hospice enrollment. Design: We compared patients who received PCIH (n = 55) to a retrospective cohort (n = 57) receiving usual care in an outpatient hepatology clinic. Setting/Subjects: From June 2016 to November 2017, we enrolled patients receiving care in a U.S. public hospital clinic who met the following inclusion criteria: (1) ESLD with a Model for End-Stage Liver Disease score ≥20, (2) hepatology approval for PC referral, and (3) at least one advanced complication of ESLD. Measurements: We assessed patient demographics, clinical information, health care insurance status, health care utilization, completion of psychosocial assessments, and ACP using two-sided Fisher's exact test and Mann-Whitney U tests. Results: Patients receiving PCIH more frequently had goals of care discussions (87.3% vs. 21.2% p ≤ 0.01), completed ACP documentation (56.4% vs. 7.0%, p ≤ 0.01), psychosocial assessments (98.2% vs. 35.1%, p ≤ 0.01), and hospice enrollment (25.5% vs. 7.0%, p = 0.01). Patients receiving PCIH who were hospitalized also had fewer mean hospitalization days (13 vs. 19.7 days, p ≤ 0.01). Conclusions: Embedding PC services in a hepatology clinic is a promising strategy to improve care for ESLD patients in public hospitals.


Subject(s)
Advance Care Planning , End Stage Liver Disease , Gastroenterology , Humans , Palliative Care , Pilot Projects , Retrospective Studies , Severity of Illness Index
3.
Healthcare (Basel) ; 9(10)2021 Oct 06.
Article in English | MEDLINE | ID: mdl-34683011

ABSTRACT

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) can cause a wide range of severity and functional impairment, leaving some patients able to work while others are homebound or bedbound. The most severely ill patients may need total care. Yet, patients with severe or very severe ME/CFS struggle to receive appropriate medical care because they cannot travel to doctors' offices and their doctors lack accurate information about the nature of this disease and how to diagnose and manage it. Recently published clinical guidance provides updated information about ME/CFS but advice on caring for the severely ill is limited. This article is intended to fill that gap. Based on published clinical guidance and clinical experience, we describe the clinical presentation of severe ME/CFS and provide patient-centered recommendations on diagnosis, assessment and approaches to treatment and management. We also provide suggestions to support the busy provider in caring for these patients by leveraging partnerships with the patient, their caregivers, and other providers and by using technology such as telemedicine. Combined with compassion, humility, and respect for the patient's experience, such approaches can enable the primary care provider and other healthcare professionals to provide the care these patients require and deserve.

4.
Mayo Clin Proc ; 96(11): 2861-2878, 2021 11.
Article in English | MEDLINE | ID: mdl-34454716

ABSTRACT

Despite myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) affecting millions of people worldwide, many clinicians lack the knowledge to appropriately diagnose or manage ME/CFS. Unfortunately, clinical guidance has been scarce, obsolete, or potentially harmful. Consequently, up to 91% of patients in the United States remain undiagnosed, and those diagnosed often receive inappropriate treatment. These problems are of increasing importance because after acute COVID-19, a significant percentage of people remain ill for many months with an illness similar to ME/CFS. In 2015, the US National Academy of Medicine published new evidence-based clinical diagnostic criteria that have been adopted by the US Centers for Disease Control and Prevention. Furthermore, the United States and other governments as well as major health care organizations have recently withdrawn graded exercise and cognitive-behavioral therapy as the treatment of choice for patients with ME/CFS. Recently, 21 clinicians specializing in ME/CFS convened to discuss best clinical practices for adults affected by ME/CFS. This article summarizes their top recommendations for generalist and specialist health care providers based on recent scientific progress and decades of clinical experience. There are many steps that clinicians can take to improve the health, function, and quality of life of those with ME/CFS, including those in whom ME/CFS develops after COVID-19. Patients with a lingering illness that follows acute COVID-19 who do not fully meet criteria for ME/CFS may also benefit from these approaches.


Subject(s)
Family Practice/standards , Fatigue Syndrome, Chronic/therapy , Physician-Patient Relations , Adult , Attitude of Health Personnel , COVID-19/epidemiology , Fatigue Syndrome, Chronic/diagnosis , Humans , Practice Patterns, Physicians'
5.
Healthcare (Basel) ; 9(6)2021 May 25.
Article in English | MEDLINE | ID: mdl-34070367

ABSTRACT

Adult patients affected by myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are at an increased risk of death by suicide. Based on the scientific literature and our clinical/research experiences, we identify risk and protective factors and provide a guide to assessing and managing suicidality in an outpatient medical setting. A clinical case is used to illustrate how information from this article can be applied. Characteristics of ME/CFS that make addressing suicidality challenging include absence of any disease-modifying treatments, severe functional limitations, and symptoms which limit therapies. Decades-long misattribution of ME/CFS to physical deconditioning or psychiatric disorders have resulted in undereducated healthcare professionals, public stigma, and unsupportive social interactions. Consequently, some patients may be reluctant to engage with mental health care. Outpatient medical professionals play a vital role in mitigating these effects. By combining evidence-based interventions aimed at all suicidal patients with those adapted to individual patients' circumstances, suffering and suicidality can be alleviated in ME/CFS. Increased access to newer virtual or asynchronous modalities of psychiatric/psychological care, especially for severely ill patients, may be a silver lining of the COVID-19 pandemic.

6.
Work ; 66(2): 265-275, 2020.
Article in English | MEDLINE | ID: mdl-32568143

ABSTRACT

BACKGROUND: Post-exertional malaise (PEM) is an exacerbation of symptoms that leads to a reduction in functionality. Recognition of PEM is important for the diagnosis and treatment of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). OBJECTIVE: Symptoms following cardiopulmonary exercise testing were compared between ME/CFS patients and healthy controls. METHODS: Open-ended questionnaires were provided to subjects following two maximal exercise tests, 24 hours apart. Subjects evaluated how they felt at five time points. Responses were classified into 19 symptom categories. RESULTS: ME/CFS subjects (n = 49) reported an average of 14±7 symptoms compared to 4±3 by controls (n = 10). During the seven days afterwards, ME/CFS subjects reported 4±3 symptoms. None were reported by controls. Fatigue, cognitive dysfunction, and sleep problems were reported with the greatest frequency. ME/CFS patients reported more symptom categories at higher frequencies than controls. The largest differences were observed in cognitive dysfunction, decrease in function, and positive feelings. CONCLUSIONS: A standardized exertional stimulus produced prolonged, diverse symptoms in ME/CFS subjects. This provides clues to the underlying pathophysiology of ME/CFS, leading to improved diagnosis and treatment.


Subject(s)
Fatigue Syndrome, Chronic/complications , Fatigue Syndrome, Chronic/diagnosis , Healthy Volunteers/statistics & numerical data , Physical Exertion/physiology , Adult , Exercise Test/methods , Fatigue Syndrome, Chronic/physiopathology , Female , Humans , Male , Middle Aged , Physical Functional Performance , Surveys and Questionnaires , United States
7.
Work ; 66(2): 315-326, 2020.
Article in English | MEDLINE | ID: mdl-32568151

ABSTRACT

BACKGROUND: Today, 24% of college and university students are affected by a chronic health condition or disability. Existing support programs, including disability services, within colleges and universities are often unaccustomed to addressing the fluctuating and unpredictable changes in health and functioning faced by students with severe chronic illnesses. This situation is especially difficult for students with lesser-known, invisible diseases like Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a complex disease affecting up to 2.5 million Americans which often begins in late adolescence or young adulthood. OBJECTIVE: Educate occupational therapists (OTs) about ME/CFS and steps they can take to assist students. METHODS: This work is based on a review of the scientific literature and our collective professional/ personal experiences. RESULTS: ME/CFS' effects on multiple organ systems combined with the unusual symptom of post-exertional malaise frequently and substantially decrease function. Currently, no effective disease-modifying treatments have been established. Nevertheless, OTs can help student maximize their participation in university life by identifying potential obstacles, formulating practical solutions and negotiating with their institutions to implement reasonable, environmental accommodations. CONCLUSIONS: Through understanding this disease, being aware of possible support options, and recommending them as appropriate, OTs are in unique position to greatly improve these students' lives.


Subject(s)
Disabled Persons/education , Fatigue Syndrome, Chronic/complications , Students/psychology , Universities/trends , Adolescent , Fatigue Syndrome, Chronic/psychology , Humans , Professional-Patient Relations , Students/classification , Universities/organization & administration , Young Adult
8.
Front Pediatr ; 7: 12, 2019.
Article in English | MEDLINE | ID: mdl-30805319

ABSTRACT

Background: Epidemiologic studies of myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS) have examined different aspects of this disease separately but few have explored them together. Objective: Describe ME/CFS onset and course in one United States-based cohort. Methods: One hundred and fifty subjects fitting Fukuda 1994 CFS criteria completed a detailed survey concerning the initial and subsequent stages of their illness. Descriptive statistics, graphs, and tables were used to illustrate prevalence and patterns of characteristics. Results: The most common peri-onset events reported by subjects were infection-related episodes (64%), stressful incidents (39%), and exposure to environmental toxins (20%). For 38% of subjects, more than 6 months elapsed from experiencing any initial symptom to developing the set of symptoms comprising their ME/CFS. Over time, the 12 most common symptoms persisted but declined in prevalence, with fatigue, unrefreshing sleep, exertion-related sickness, and flu-like symptoms declining the most (by 20-25%). Conversely, cognitive symptoms changed the least in prevalence, rising in symptom ranking. Pregnancy, menopause, and menstrual cycles exacerbated many women's symptoms. Fatigue-related function was not associated with duration of illness or age; during the worst periods of their illness, 48% of subjects could not engage in any productive activity. At the time of survey, 47% were unable to work and only 4% felt their condition was improving steadily with the majority (59%) describing a fluctuating course. Ninety-seven percent suffered from at least one other illness: anxiety (48%), depression (43%), fibromyalgia (39%), irritable bowel syndrome (38%), and migraine headaches (37%) were the most diagnosed conditions. Thirteen percent came from families where at least one other first-degree relative was also afflicted, rising to 27% when chronic fatigue of unclear etiology was included. Conclusions: This paper offers a broad epidemiologic overview of one ME/CFS cohort in the United States. While most of our findings are consistent with prior studies, we highlight underexamined aspects of this condition (e.g., the evolution of symptoms) and propose new interpretations of findings. Studying these aspects can offer insight and solutions to the diagnosis, etiology, pathophysiology, and treatment of this condition.

9.
PLoS One ; 13(6): e0197811, 2018.
Article in English | MEDLINE | ID: mdl-29856774

ABSTRACT

BACKGROUND: Post-exertional malaise (PEM) is considered to be the hallmark characteristic of myalgic encephalomyelitis/ chronic fatigue syndrome (ME/CFS). Yet, patients have rarely been asked in formal studies to describe their experience of PEM. OBJECTIVES: To describe symptoms associated with and the time course of PEM. METHODS: One hundred and fifty subjects, diagnosed via the 1994 Fukuda CFS criteria, completed a survey concerning 11 symptoms they could experience after exposure to two different types of triggers. We also inquired about onset and duration of PEM and included space for subjects to write in any additional symptoms. Results were summarized with descriptive statistics; McNemar's, paired t-, Fisher's exact and chi-square goodness-of-fit tests were used to assess for statistical significance. RESULTS: One hundred and twenty-nine subjects (90%) experienced PEM with both physical and cognitive exertion and emotional distress. Almost all were affected by exertion but 14 (10%) reported no effect with emotion. Fatigue was the most commonly exacerbated symptom but cognitive difficulties, sleep disturbances, headaches, muscle pain, and flu-like feelings were cited by over 30% of subjects. Sixty percent of subjects experienced at least one inflammatory/ immune-related symptom. Subjects also cited gastrointestinal, orthostatic, mood-related, neurologic and other symptoms. Exertion precipitated significantly more symptoms than emotional distress (7±2.8 vs. 5±3.3 symptoms (median, standard deviation), p<0.001). Onset and duration of PEM varied for most subjects. However, 11% reported a consistent post-trigger delay of at least 24 hours before onset and 84% endure PEM for 24 hours or more. CONCLUSIONS: This study provides exact symptom and time patterns for PEM that is generated in the course of patients' lives. PEM involves exacerbation of multiple, atypical symptoms, is occasionally delayed, and persists for extended periods. Highlighting these characteristics may improve diagnosis of ME/CFS. Incorporating them into the design of future research will accelerate our understanding of ME/CFS.


Subject(s)
Fatigue Syndrome, Chronic/complications , Fatigue Syndrome, Chronic/physiopathology , Physical Exertion , Surveys and Questionnaires , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged
10.
Ann Intern Med ; 167(6): 447-448, 2017 09 19.
Article in English | MEDLINE | ID: mdl-28975326
11.
Proc Natl Acad Sci U S A ; 114(34): E7150-E7158, 2017 08 22.
Article in English | MEDLINE | ID: mdl-28760971

ABSTRACT

Although some signs of inflammation have been reported previously in patients with myalgic encephalomyelitis or chronic fatigue syndrome (ME/CFS), the data are limited and contradictory. High-throughput methods now allow us to interrogate the human immune system for multiple markers of inflammation at a scale that was not previously possible. To determine whether a signature of serum cytokines could be associated with ME/CFS and correlated with disease severity and fatigue duration, cytokines of 192 ME/CFS patients and 392 healthy controls were measured using a 51-multiplex array on a Luminex system. Each cytokine's preprocessed data were regressed on ME/CFS severity plus covariates for age, sex, race, and an assay property of newly discovered importance: nonspecific binding. On average, TGF-ß was elevated (P = 0.0052) and resistin was lower (P = 0.0052) in patients compared with controls. Seventeen cytokines had a statistically significant upward linear trend that correlated with ME/CFS severity: CCL11 (Eotaxin-1), CXCL1 (GROα), CXCL10 (IP-10), IFN-γ, IL-4, IL-5, IL-7, IL-12p70, IL-13, IL-17F, leptin, G-CSF, GM-CSF, LIF, NGF, SCF, and TGF-α. Of the 17 cytokines that correlated with severity, 13 are proinflammatory, likely contributing to many of the symptoms experienced by patients and establishing a strong immune system component of the disease. Only CXCL9 (MIG) inversely correlated with fatigue duration.


Subject(s)
Cytokines/blood , Fatigue Syndrome, Chronic/blood , Adult , Aged , Biomarkers/blood , Case-Control Studies , Chemokine CXCL1/blood , Chemokine CXCL1/immunology , Chemokine CXCL10/blood , Chemokine CXCL10/immunology , Cytokines/immunology , Fatigue Syndrome, Chronic/immunology , Female , Humans , Male , Middle Aged , Severity of Illness Index , Transforming Growth Factor beta1/blood , Transforming Growth Factor beta1/immunology
12.
Anal Chem ; 89(6): 3562-3567, 2017 03 21.
Article in English | MEDLINE | ID: mdl-28199092

ABSTRACT

A significant challenge of traditional glycan mapping techniques is that they do not provide site-specific glycosylation information. Therefore, for proteins containing multiple glycosylation sites, the individual glycan species present at a particular site cannot be differentiated from those species present at the other glycosylation sites on the molecule. Quantification of glycoform has previously been demonstrated using a multiattribute method (MAM), which can quantify multiple post-translational modifications including deamidation, oxidation, glycosylation variants, and fragmentation ( Rogers, R. S.; Nightlinger, N. S.; Livingston, B.; Campbell, P.; Bailey, R.; Balland, A. MAbs 2015 , 7 , 881 - 890 ; ref 1). In this paper we describe the application of an MAM based method for site specific quantification of N-linked glycan heterogeneity present on an IgG1 mAb molecule containing two distinct N-linked glycosylation sites: one present on the heavy chain (HC) variable region (Fab) and the other present on the conserved HC constant region (Fc). MAM is a peptide mapping method utilizing mass spectrometry to detect and quantify specific peptides of interest. The ionization properties of the glycopeptides with different classes of glycan structural variants, including high mannose, sialylated, and terminal galactosylated species were studied in detail. Our results demonstrate that MAM quantification of individual glycan species from both the Fab and Fc N-Linked glycosylation sites is consistent with quantification using the traditional hydrophilic interaction liquid chromatography (HILIC) analysis of enzymatically released and fluorescently labeled glycans. Furthermore, no significant impact from the glycoform on the ionization properties of the glycopeptide is observed. Our work demonstrates that the MAM method is a suitable approach for providing quantitative, site-specific glycan information for profiling of N-linked glycans on immunoglobulins.


Subject(s)
Antibodies, Monoclonal/immunology , Polysaccharides/analysis , Antibodies, Monoclonal/metabolism , Chromatography, Liquid , Glycosylation , Polysaccharides/immunology , Polysaccharides/metabolism , Protein Processing, Post-Translational , Tandem Mass Spectrometry
14.
Prev Vet Med ; 120(3-4): 349-56, 2015 Jul 01.
Article in English | MEDLINE | ID: mdl-25962956

ABSTRACT

BACKGROUND: Chagas disease, a vector-borne disease transmitted by triatomine bugs and caused by the parasite Trypanosoma cruzi, affects millions of people in the Americas. In Arequipa, Peru, indoor residual insecticide spraying campaigns are routinely conducted to eliminate Triatoma infestans, the only vector in this area. Following insecticide spraying, there is risk of vector return and reinitiation of parasite transmission. Dogs are important reservoirs of T. cruzi and may play a role in reinitiating transmission in previously sprayed areas. Dogs may also serve as indicators of reemerging transmission. METHODS: We conducted a cross-sectional serological screening to detect T. cruzi antibodies in dogs, in conjunction with an entomological vector collection survey at the household level, in a disease endemic area that had been treated with insecticide 13 years prior. Spatial clustering of infected animals and vectors was assessed using Ripley's K statistic, and the odds of being seropositive for dogs proximate to infected colonies was estimated with multivariate logistic regression. RESULTS: There were 106 triatomine-infested houses (41.1%), and 45 houses infested with T. cruzi-infected triatomine insects (17.4%). Canine seroprevalence in the area was 12.3% (n=154); all seropositive dogs were 9 months old or older. We observed clustering of vectors carrying the parasite, but no clustering of seropositive dogs. The age- and sex-adjusted odds ratio between seropositivity to T. cruzi and proximity to an infected triatomine (≤50m) was 5.67 (95% CI: 1.12-28.74; p=0.036). CONCLUSIONS: Targeted control of reemerging transmission can be achieved by improved understanding of T. cruzi in canine populations. Our results suggest that dogs may be useful sentinels to detect re-initiation of transmission following insecticide treatment. Integration of canine T. cruzi blood sampling into existing interventions for zoonotic disease control (e.g., rabies vaccination programs) can be an effective method of increasing surveillance and improving understanding of disease distribution.


Subject(s)
Chagas Disease/veterinary , Dog Diseases/epidemiology , Endemic Diseases/veterinary , Insect Vectors/parasitology , Sentinel Surveillance/veterinary , Triatoma/parasitology , Trypanosoma cruzi/isolation & purification , Animals , Antibodies, Protozoan/blood , Chagas Disease/epidemiology , Chagas Disease/parasitology , Chagas Disease/transmission , Cross-Sectional Studies , Dog Diseases/parasitology , Dog Diseases/transmission , Dogs , Female , Male , Peru/epidemiology , Prevalence , Seroepidemiologic Studies , Spatial Analysis
15.
J Transl Med ; 11: 93, 2013 Apr 09.
Article in English | MEDLINE | ID: mdl-23570606

ABSTRACT

BACKGROUND: Chronic fatigue syndrome (CFS) is a debilitating disorder characterized by persistent fatigue that is not alleviated by rest. The lack of a clearly identified underlying mechanism has hindered the development of effective treatments. Studies have demonstrated elevated levels of inflammatory factors in patients with CFS, but findings are contradictory across studies and no biomarkers have been consistently supported. Single time-point approaches potentially overlook important features of CFS, such as fluctuations in fatigue severity. We have observed that individuals with CFS demonstrate significant day-to-day variability in their fatigue severity. METHODS: Therefore, to complement previous studies, we implemented a novel longitudinal study design to investigate the role of cytokines in CFS pathophysiology. Ten women meeting the Fukuda diagnostic criteria for CFS and ten healthy age- and body mass index (BMI)-matched women underwent 25 consecutive days of blood draws and self-reporting of symptom severity. A 51-plex cytokine panel via Luminex was performed for each of the 500 serum samples collected. Our primary hypothesis was that daily fatigue severity would be significantly correlated with the inflammatory adipokine leptin, in the women with CFS and not in the healthy control women. As a post-hoc analysis, a machine learning algorithm using all 51 cytokines was implemented to determine whether immune factors could distinguish high from low fatigue days. RESULTS: Self-reported fatigue severity was significantly correlated with leptin levels in six of the participants with CFS and one healthy control, supporting our primary hypothesis. The machine learning algorithm distinguished high from low fatigue days in the CFS group with 78.3% accuracy. CONCLUSIONS: Our results support the role of cytokines in the pathophysiology of CFS.


Subject(s)
Cytokines/metabolism , Fatigue Syndrome, Chronic/metabolism , Fatigue/metabolism , Leptin/metabolism , Adult , Algorithms , Biomarkers/metabolism , Body Mass Index , Case-Control Studies , Fatigue/diagnosis , Fatigue Syndrome, Chronic/diagnosis , Female , Humans , Inflammation , Leptin/blood , Longitudinal Studies , Middle Aged , Reproducibility of Results , Treatment Outcome
17.
Glycobiology ; 22(2): 221-34, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21930650

ABSTRACT

Glycation of immunoglobulin G (IgG) can result from incubation with a reducing sugar in vitro or during circulation in vivo. Upon injection of a recombinantly produced human therapeutic IgG into humans, changes in the glycation levels could be observed as a function of circulation time. Mass changes on the individual IgG polypeptide chains as the results of glycation were determined using reversed-phase liquid chromatography/mass spectrometry. Changes to the light and heavy chains were low but easily detectable at 0.00092 and 0.0021 glucose (Glc) additions per chain per day, respectively. Levels of glycation found on the Fc portion of IgG isolated from healthy subjects, using a similar analytical approach, were on average 0.045 Glc molecules per fragment. In vivo glycation rates could be approximated in vitro by modeling the physiological glycation reaction with a simplified incubation containing physiological Glc concentrations, pH and temperature but with a high concentration of a single purified IgG. To test the impact of glycation on IgG function, highly glycated IgG1 and IgG2 were prepared containing on average 42-49 Glc molecules per IgG. Binding to FcγIIIa receptors, neonatal Fc receptor or protein A was similar or identical to the non-glycated IgG controls. Although the modifications were well distributed throughout the protein sequence, and at high enough levels to affect the elution position by size-exclusion chromatography, no changes in the tested Fc functions were observed.


Subject(s)
Glucose/chemistry , Immunoglobulin Fc Fragments/chemistry , Immunoglobulin G/chemistry , Protein Processing, Post-Translational , Chromatography, Reverse-Phase , Glycosylation , Histocompatibility Antigens Class I/chemistry , Histocompatibility Antigens Class I/metabolism , Humans , Hydrogen-Ion Concentration , Immunoglobulin G/metabolism , Mass Spectrometry , Peptide Mapping , Receptors, Fc/chemistry , Receptors, Fc/metabolism , Staphylococcal Protein A/chemistry , Staphylococcal Protein A/metabolism , Temperature
18.
PLoS Negl Trop Dis ; 5(2): e970, 2011 Feb 22.
Article in English | MEDLINE | ID: mdl-21364970

ABSTRACT

BACKGROUND: The history of Chagas disease control in Peru and many other nations is marked by scattered and poorly documented vector control campaigns. The complexities of human migration and sporadic control campaigns complicate evaluation of the burden of Chagas disease and dynamics of Trypanosoma cruzi transmission. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional serological and entomological study to evaluate temporal and spatial patterns of T. cruzi transmission in a peri-rural region of La Joya, Peru. We use a multivariate catalytic model and Bayesian methods to estimate incidence of infection over time and thereby elucidate the complex history of transmission in the area. Of 1,333 study participants, 101 (7.6%; 95% CI: 6.2-9.0%) were confirmed T. cruzi seropositive. Spatial clustering of parasitic infection was found in vector insects, but not in human cases. Expanded catalytic models suggest that transmission was interrupted in the study area in 1996 (95% credible interval: 1991-2000), with a resultant decline in the average annual incidence of infection from 0.9% (95% credible interval: 0.6-1.3%) to 0.1% (95% credible interval: 0.005-0.3%). Through a search of archival newspaper reports, we uncovered documentation of a 1995 vector control campaign, and thereby independently validated the model estimates. CONCLUSIONS/SIGNIFICANCE: High levels of T. cruzi transmission had been ongoing in peri-rural La Joya prior to interruption of parasite transmission through a little-documented vector control campaign in 1995. Despite the efficacy of the 1995 control campaign, T. cruzi was rapidly reemerging in vector populations in La Joya, emphasizing the need for continuing surveillance and control at the rural-urban interface.


Subject(s)
Chagas Disease/epidemiology , Chagas Disease/transmission , Communicable Disease Control/history , Communicable Disease Control/methods , Adolescent , Adult , Antibodies, Protozoan/blood , Chagas Disease/drug therapy , Child , Cross-Sectional Studies , Female , History, 20th Century , History, 21st Century , Humans , Insect Control/history , Male , Middle Aged , Peru/epidemiology , Recurrence , Rural Population , Seroepidemiologic Studies , Time Factors , Topography, Medical , Trypanosoma cruzi/immunology , Young Adult
19.
Curr Pharm Biotechnol ; 9(6): 447-67, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19075685

ABSTRACT

This article provides an overview of the upstream technologies used in the industrial production of therapeutic monoclonal antibodies (mAbs) based on the cultivation of mammalian cells. More specifically, in a first section, after a short discussion of relevant biochemical characteristics of antibodies, we review the cell lines currently employed in commercial production and the methods of constructing and isolating production clones. This is followed with a review of the most current methods of commercial scale production and their associated technologies. Selected references and short discussions pertaining to emerging and relevant technologies have been embedded throughout the text in order to give a sense of the overall direction the field is taking.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Cells, Cultured/immunology , Drug Design , Drug Industry/trends , Protein Engineering/trends , Technology, Pharmaceutical/trends , Animals , Forecasting , Humans , Immunotherapy/methods , Immunotherapy/trends , Mammals
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