Antibody chemical reactivity: Beneficial and pathogenic roles

Antibodies (Abs) to autoantigens and foreign antigens (Ags) mediate, respectively, various pathogenic and beneficial effects. Abs express enzyme-like nucleophiles that react covalently with electrophiles. A subpopulation of nucleophilic Abs expresses proteolytic activity, which can inactivate the Ag permanently. This thesis shows how the nucleophilicity can be exploited to inhibit harmful Abs or potentially protect against a virus. ^ Inactivation of pathogenic Abs from Hemophilia A (HA) patients by means of nucleophile-electrophile pairing was studied. Deficient factor VIII (FVIII) in HA subjects impairs blood coagulation. FVIII replacement therapy fails in 20-30% of HA patients due to production of anti-FVIII Abs. FVIII analogs containing electrophilic phosphonate group (E-FVIII and E-C2) were hypothesized to inactivate the Abs by reacting specifically and covalently with nucleophilic sites. Anti-FVIII IgGs from HA patients formed immune complexes with E-FVIII and E-C2 that remained irreversibly associated under conditions that disrupt noncovalent Ab-Ag complexes. The reaction induced irreversible loss of Ab anti-coagulant activity. E-FVIII alone displayed limited interference with coagulation. E-FVIII is a prototype reagent suitable for further development as a selective inactivator of pathogenic anti-FVIII Abs. ^ The beneficial function of Abs to human immunodeficiency virus type 1 (HIV-1) was analyzed. HIV-1 eludes the immune system by rapidly changing its coat protein structure. IgAs from noninfected subjects hydrolyzed gp120 and neutralized HIV-1 with modest potency by recognizing the gp120 421-433 epitope, a conserved B cell superantigenic region that is also essential for HIV-1 attachment to host cell CD4 receptors. An adaptive immune response to superantigens is generally prohibited due to their ability to downregulate B cells. IgAs from subjects with prolonged HIV-1 infection displayed improved catalytic hydrolysis of gp120 and exceptionally potent and broad neutralization of diverse CCR5-dependent primary HIV isolates attributable to recognition of the 421-433 epitope. This indicates that slow immunological bypass of the superantigenic character of gp120 is possible, opening the path to effective HIV vaccination. ^ My research reveals a novel route to inactivate pathogenic nucleophilic Abs using electrophilic antigens. Conversely, naturally occurring nucleophilic Abs may help impede HIV infection, and the Abs could be developed for passive immunotherapy of HIV infected subjects. ^

A critical review: Why isn't "cold pasteurization" being used widespread as a method to prevent food-related illnesses as a result of the consumption of ready-to-eat, fresh fruits, and vegetables

The Centers for Disease Control estimates that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year. The American public is becoming more health conscious and there has been an increase in the dietary intake of fresh fruits and vegetables. Affluence and demand for convenience has allowed consumers to opt for pre-processed packaged fresh fruits and vegetables. These pre-processed foods are considered Ready-to-Eat. They have many of the advantages of fresh produce without the inconvenience of processing at home. After seeing a decline in food-related illnesses between 1996 and 2004, due to an improvement in meat and poultry safety, tainted produce has tilted the numbers back. This has resulted in none of the Healthy People 2010 targets for food-related illness reduction being reached. Irradiation has been shown to be effective in eliminating many of the foodborne pathogens. The application of irradiation as a food safety treatment has been widely endorsed by many of the major associations involved with food safety and public health. Despite these endorsements there has been very little use of this technology to date for reducing the disease burden associated with the consumption of these products. A review of the available literature since the passage of the 1996 Food Quality Protection Act was conducted on the barriers to implementing irradiation as a food safety process for fresh fruits and vegetables. The impediments to adopting widespread utilization of irradiation food processing as a food safety measure involve a complex array of legislative, regulatory, industry, and consumer issues. The FDA’s approval process limits the expansion of the list of foods approved for the application of irradiation as a food safety process. There is also a lack of capacity within the industry to meet the needs of a geographically dispersed industry.^

Impact of real time polymerase chain reaction technology on the therapeutic approach to treatment of staphylococcal infections

Can the early identification of the species of staphylococcus responsible for infection by the use of Real Time PCR technology influence the approach to the treatment of these infections? ^ This study was a retrospective cohort study in which two groups of patients were compared. The first group, ‘Physician Aware’ consisted of patients in whom physicians were informed of specific staphylococcal species and antibiotic sensitivity (using RT-PCR) at the time of notification of the gram stain. The second group, ‘Physician Unaware’ consisted of patients in whom treating physicians received the same information 24–72 hours later as a result of blood culture and antibiotic sensitivity determination. ^ The approach to treatment was compared between ‘Physician Aware’ and ‘Physician Unaware’ groups for three different microbiological diagnoses—namely MRSA, MSSA and no-SA (or coagulase negative Staphylococcus). ^ For a diagnosis of MRSA, the mean time interval to the initiation of Vancomycin therapy was 1.08 hours in the ‘Physician Aware’ group as compared to 5.84 hours in the ‘Physician Unaware’ group (p=0.34). ^ For a diagnosis of MSSA, the mean time interval to the initiation of specific anti-MSSA therapy with Nafcillin was 5.18 hours in the ‘Physician Aware’ group as compared to 49.8 hours in the ‘Physician Unaware’ group (p=0.007). Also, for the same diagnosis, the mean duration of empiric therapy in the ‘Physician Aware’ group was 19.68 hours as compared to 80.75 hours in the ‘Physician Unaware’ group (p=0.003) ^ For a diagnosis of no-SA or coagulase negative staphylococcus, the mean duration of empiric therapy was 35.65 hours in the ‘Physician Aware’ group as compared to 44.38 hours in the ‘Physician Unaware’ group (p=0.07). However, when treatment was considered a categorical variable and after exclusion of all cases where anti-MRS therapy was used for unrelated conditions, only 20 of 72 cases in the ‘Physician Aware’ group received treatment as compared to 48 of 106 cases in the ‘Physician Unaware’ group. ^ Conclusions. Earlier diagnosis of MRSA may not alter final treatment outcomes. However, earlier identification may lead to the earlier institution of measures to limit the spread of infection. The early diagnosis of MSSA infection, does lead to treatment with specific antibiotic therapy at an earlier stage of treatment. Also, the duration of empiric therapy is greatly reduced by early diagnosis. The early diagnosis of coagulase negative staphylococcal infection leads to a lower rate of unnecessary treatment for these infections as they are commonly considered contaminants. ^

Report on the practice based culminating experience as teaching assistant for "Pathology and Public Health" class taught at University of Texas School of Public Health, Houston

Objectives. The objectives of this report were to describe current best standards in online education, class competencies, class objectives, class activities and to compare the class competencies, objectives and activities undertaken with the current best practices in online teaching and to provide a list of recommendations based on the most efficacious practices. ^ Methods. Utilizing the key words- online teaching, national standards, quality, online courses, I: (1) conducted a search on Google to find the best standard for quality online courses; the search yielded National Standards for Quality Online Teaching as the gold standard in online course quality; (2) specified class objectives and competencies as well as major activities undertaken as a part of the class. Utilizing the Southern Regional Education Board evaluation checklist for online courses, I: (1) performed an analysis comparing the class activities, objectives, and competencies with the current best standards; (2) utilized the information obtained from the analysis and class experiences to develop recommendations for the most efficacious online teaching practices. ^ Results. The class met the criteria set by the Southern Regional Education Board for evaluating online classes completely in 75%, partially in 16% and did not meet the criteria in 9% cases. The majority of the parameters in which the class did not meet the standards (4 of 5) were due to technological reasons beyond the scope of the class instructor, teaching assistant and instructional design. ^ Discussion. Successful online teaching requires awareness of technology, good communication, methods, collaboration, reflection and flexibility. Creation of an online community, engaging online learners and utilizing different learning styles and assessment methods promote learning. My report proposes that online teaching should actively engage the students and teachers with multiple interactive strategies as evidenced from current best standards of online education and my “hands-on” work experience. ^ Conclusion. The report and the ideas presented are intended to create a foundation for efficacious practice on the online teaching platform. By following many of the efficacious online practices described in the report and adding from their own experiences, online instructors and teaching assistants can contribute to effective online learning. ^

Maximal exercise hemodynamics and risk of mortality in apparently healthy men and women

The use of exercise electrocardiography (ECG) to detect latent coronary heart disease (CHD) is discouraged in apparently healthy populations because of low sensitivity. These recommendations however, are based on the efficacy of evaluation of ischemia (ST segment changes) with little regard for other measures of cardiac function that are available during exertion. The purpose of this investigation was to determine the association of maximal exercise hemodynamic responses with risk of mortality due to all-causes, cardiovascular disease (CVD), and coronary heart disease (CHD) in apparently healthy individuals. Study participants were 20,387 men (mean age = 42.2 years) and 6,234 women (mean age = 41.9 years) patients of a preventive medicine center in Dallas, TX examined between 1971 and 1989. During an average of 8.1 years of follow-up, there were 348 deaths in men and 66 deaths in women. In men, age-adjusted all-cause death rates (per 10,000 person years) across quartiles of maximal systolic blood pressure (SBP) (low to high) were: 18.2, 16.2, 23.8, and 24.6 (p for trend $<$0.001). Corresponding rates for maximal heart rate were: 28.9, 15.9, 18.4, and 15.1 (p trend $<$0.001). After adjustment for confounding variables including age, resting systolic pressure, serum cholesterol and glucose, body mass index, smoking status, physical fitness and family history of CVD, risks (and 95% confidence interval (CI)) of all-cause mortality for quartiles of maximal SBP, relative to the lowest quartile, were: 0.96 (0.70-1.33), 1.36 (1.01-1.85), and 1.37 (0.98-1.92) for quartiles 2-4 respectively. Similar risks for maximal heart rate were: 0.61 (0.44-0.85), 0.69 (0.51-0.93), and 0.60 (0.41-0.87). No associations were noted between maximal exercise rate-pressure product mortality. Similar results were seen for risk of CVD and CHD death. In women, similar trends in age-adjusted all-cause and CVD death rates across maximal SBP and heart rate categories were observed. Sensitivity of the exercise test in predicting mortality was enhanced when ECG results were evaluated together with maximal exercise SBP or heart rate with a concomitant decrease in specificity. Positive predictive values were not improved. The efficacy of the exercise test in predicting mortality in apparently healthy men and women was not enhanced by using maximal exercise hemodynamic responses. These results suggest that an exaggerated systolic blood pressure or an attenuated heart rate response to maximal exercise are risk factors for mortality in apparently healthy individuals. ^

Infectious diseases, immune status, and health insurance among child care providers in Houston, Texas

The objectives of this study were to compare female child-care providers with female university workers and with mothers of children in child-care centers for: (1) frequency of illness and work loss days due to infectious diseases, (2) prevalence of antibodies against measles, rubella, mumps, hepatitis B, hepatitis A, chickenpox and cytomegalovirus (CMV), and (3) status regarding health insurance and job benefits.^ Subjects from twenty child-care centers and twenty randomly selected departments of a university in Houston, Texas were studied in a cross-sectional fashion.^ A cluster sample of 281 female child-care providers from randomly selected child-care centers, a cluster sample of 286 university workers from randomly selected departments and a systematic sample of 198 mothers of children from randomly selected child-care centers.^ Main outcome measures were: (1) self-reported frequency of infectious diseases and number of work-days lost due to infectious diseases; (2) presence of antibodies in blood; and (3) self-reported health insurance and job benefits.^ In comparison to university workers, child-care providers reported a higher prevalence of infectious diseases in the past 30 days; lost three times more work-days due to infectious diseases; and were more likely to have anti-core antibodies against hepatitis B (odds ratio = 3.16 95% CI 1.27-7.85) and rubella (OR 1.88, 95% CI 1.02-3.45). Child-care providers had less health insurance and job-related benefits than mothers of children attending child-care centers.^ Regulations designed to reduce transmission of vaccine and non-vaccine preventable diseases in child-care centers should be strictly enforced. In addition policies to improve health insurance and job benefits of child-care providers are urgently needed. ^

The incidence of necrotizing changes in adults with pneumococcal pneumonia

Background. Necrotizing pneumonia is generally considered a rare complication of pneumococcal pneumonia in adults. We systematically studied the incidence of necrotizing changes in adult patients with pneumococcal pneumonia, and examined the severity of infection, the role of causative serotype and the association with bacteremia. ^ Methods. We used a data base of all pneumococcal infections identified at our medical center between 2000 and 2010. Original readings of chest X-rays (CXR) and computerized tomography (CT) were noted. All images were then reread independently by 2 radiologists. The severity of disease was assessed using the SMART-COP scoring system. ^ Results. There were 351 cases of pneumococcal pneumonia. Necrosis was reported in no original CXR readings and 6 of 136 (4.4%) CTs. With re-reading, 8 of 351 (2.3%) CXR and 15 of 136 (11.0%) CT had necrotizing changes. Overall, these changes were found in 23 of 351 (6.6%, 95% CI 4.0 - 9.1) patients. The incidence of bacteremia and the admitting SMART-COP scores were similar in patients with and without necrosis (P=1.00 and P=0.32, respectively). Type 3 pneumococcus was more commonly isolated from patients with than from patients without necrotizing pneumonia (P=0.05), but a total of 10 serotypes were identified among 16 cases in which the organism was available for typing. ^ Conclusions. Necrotizing changes in the lungs were seen in 6.6% (95% CI 4.0 - 9.1) of a large series of adults with pneumococcal pneumonia. Patients with necrosis were not more likely to have bacteremia or more severe disease. Type 3 pneumococcus was commonly implicated, but 9 other serotypes were also identified.^

Prevalence of symptoms of neurotoxicity and potential occupational pesticide and solvent exposures among high school students in Starr County, Texas: A pilot study

Numerous harmful occupational exposures affect working teens in the United States. Teens working in agriculture and other heavy-labor industries may be at risk for occupational exposures to pesticides and solvents. The neurotoxicity of pesticides and solvents at high doses is well-known; however, the long term effects of these substances at low doses on occupationally exposed adolescents have not been well-studied. To address this research gap, a secondary analysis of cross-sectional data was completed in order to estimate the prevalence of self-reported symptoms of neurotoxicity among a cohort of high school students from Starr County, Texas, a rural area along the Texas-Mexico border. Multivariable linear regression was used to estimate the association between work status (i.e., no work, farm work, and non-farm work) and symptoms of neurotoxicity, while controlling for age, gender, Spanish speaking preference, inhalant use, tobacco use, and alcohol use. The sample included 1,208 students. Of these, the majority (85.84%) did not report having worked during the prior nine months compared to 4.80% who did only farm work, 6.21% who did only non-farm work, and 3.15% who did both types of work. On average, students reported 3.26 symptoms with a range from 0-16. The most commonly endorsed items across work status were those related to memory impairment. Adolescents employed in non-farm work jobs reported more neurotoxicity symptoms than those who reported that they did not work (Mean 4.31; SD 3.97). In the adjusted multivariable regression model, adolescents reporting non-farm work status reported an average of 0.77 more neurotoxicity symptoms on the Q16 than those who did not work (P = 0.031). The confounding variables included in the final model were all found to be factors significantly associated with report of neurotoxicity symptoms. Future research should examine the relationship between these variables and self-report of symptoms of neurotoxicity.^

InGen of creative production in the health sciences: A workbook companion to innovation generation

InGen of Creative Production in the Health Sciences is a compendium of innovative thinking exercises for individuals and groups, derived from an eclectic array of practical guides for professionals in a variety of fields. Segmented into five subcategories across twenty two chapters, the effort seeks to make techniques for increasing innovative problem solving more accessible to a diverse audience of problem solvers. The chapters of Roberta Ness. Innovation Generation (2012, Oxford University Press) provide the themes for each of the chapters in the workbook. It is intended that those who read Ness. Innovation Generation will benefit from practicing the constructs of innovative thinking exemplified in each exercise.^ The methods used to gather data, in this case mostly innovative thinking exercises, included literature reviews of existing innovative thinking tools, classroom materials, and theory-driven exploration of exercises to fill in gaps in extant materials. Specifically, Google.com and Amazon.com searches were conducted using the terms “innovation,” “innovative,” “innovator,” “creative,” “novelty,” “thinking,” together with some variance of “book,” “workbook,” and “exercise.” The results were sorted thematically to show correspondence with the themes in Ness (2012) and compared to suggested best practices of 50 years of scientific research on innovative thinking. Where themes were suggested by Ness (2012) and peer-reviewed research on innovation but unavailable in published innovation thinking workbooks, new exercises were developed. The five type subcategories into which these results were organized are: individual direct, individual indirect, group direct, group indirect and probing question. It is anticipated that the five type subcategories and spectrum of themes will equip problem solvers in a variety of capacities.^

The relationship between obesity, autoimmune disease, and C-reactive protein: A secondary data analysis of the National Health and Nutrition Examination Survey (NHANES) 2009--2010

Autoimmune diseases are a group of inflammatory conditions in which the body's immune system attacks its own cells. There are over 80 diseases classified as autoimmune disorders, affecting up to 23.5 million Americans. Obesity affects 32.3% of the US adult population, and could also be considered an inflammatory condition, as indicated by the presence of chronic low-grade inflammation. C-reactive protein (CRP) is a marker of inflammation, and is associated with both adiposity and autoimmune inflammation. This study sought to determine the cross-sectional association between obesity and autoimmune diseases in a large, nationally representative population derived from NHANES 2009–10 data, and the role CRP might play in this relationship. Overall, the results determined that individuals with autoimmune disease were 2.11 times more likely to report being overweight than individuals without autoimmune disease and that CRP had a mediating affect on the obesity-autoimmune relationship. ^

Occupational health and safety among commercial sex workers in Ghana

The topic of occupational health and safety (OHS) has been investigated for many years and continues to be a concept often researched today. Generally speaking OHS research has been centered around food safety, construction safety, transportation safety, fire safety, drug and alcohol testing, health and medical management, and industrial hygiene to name a few. However, the concept of OHS concerning female commercial sex workers (FCSWs) has rarely been investigated, often neglected, seldom discussed and is lacking in sound research. Although regarded as the "oldest profession", commercial sex work (CSW) has consistently been ignored, disregarded and under-researched due to the illegality and stigmatization of prostitution. This paper reviews occupational safety and health issues faced by FCSWs in Tema and Accra, Ghana, through in-depth interviews, visits to women's homes, field work, informal conversations and participant observations with FCSWs over a period of two months. Facets of OHS that emerged among FCSWs included sexually transmissible infections, risks associated with harassment and violence from police and clients, alcohol and drug use, irregular hospital visits and/or lack of hospital visits, immigration issues, legal and policing risks. We argue that CSW be viewed as an occupation in great need of interventions to reduce workplace risks and improve the health and safety of FCSWs^

Calmodulin -regulated processes and intracellular calcium in the heat stress response of mammalian cells

Three approaches were used to examine the role of Ca$\sp{2+}$- and/or calmodulin (CaM)-regulated processes in the mammalian heat stress response. The focus of the first approach was on the major Ca$\sp{2+}$-binding protein, CaM, and involved the use of CaM antagonists that perturbed CaM-regulated processes during heat stress. The second approach involved the use of a cell line and its BPV-1 transformants that express increased basal levels of CaM, or parvalbumin--a Ca$\sp{2+}$-binding protein not normally found in these cells. The last approach used Ca$\sp{2+}$ chelators to buffer Ca$\sp{2+}$-transients.^ The principle conclusions resulting from these three experimental approaches are: (1) CaM antagonists cause a temperature-dependent potentiation of heat killing, but do not inhibit the triggering and development of thermotolerance suggesting some targets for heat killing are different from those that lead to thermotolerance; (2) Members of major HSP families (especially HSP70) can bind to CaM in a Ca$\sp{2+}$-dependent manner in vitro, and HSP have been associated with events leading to thermotolerance. But, because thermotolerance is not affected by CaM antagonists, and antagonists should interfere with HSP binding to CaM, the events leading to triggering or developing thermotolerance were not strongly dependent on HSP binding to CaM; (3) CaM antagonists can also bind to HSP70 (and possibly other HSP) suggesting an alternative mechanism for the action of these agents in heat killing may involve direct binding to other proteins, like HSP70, whose function is important for survival following heating and inhibiting their activity; and (4) The signal governing the rate of synthesis of another major HSP group, the HSP26 family, can be largely abrogated by elevated Ca$\sp{2+}$-binding proteins or Ca$\sp{2+}$ chelators without significantly reducing survival or thermotolerance suggesting if the HSP26 family is involved in either end point, it may function in (Ca$\sp{2+}$) $\sb{\rm i}$ homeostasis. ^

Evidence that lymphokine -activated killer (LAK) cell function is regulated by both serine and tyrosine kinase pathways

Signal transduction pathways operative in lymphokine activated killer (LAK) cells during execution of cytolytic function have never been characterized. Based on ubiquitous involvement of protein phosphorylation in activation of cytolytic mechanisms used by CTL and NK cells, it was hypothesized that changes in protein phosphorylation should occur when LAK encounter tumor targets. It was further hypothesized that protein kinases would regulate LAK-mediated cytotoxicity. Exposure to either SK-Mel-1 (melanoma) or Raji (lymphoma) targets consistently led to increased phosphorylation of two 65-kD LAK proteins pp65a and -b, with isoelectric points (pI) of 5.1 and 5.2 respectively. Increased p65 phosphorylation was initiated between 1 and 5 min after tumor coincubation, occurred on Ser residues, required physical contact between LAK and tumors, correlated with target recognition, and also occurred after crosslinking Fc$\gamma$RIIIA in the absence of tumors. Both pp65a and -b were tentatively identified as phosphorylated forms of the actin-bundling protein L-plastin, based on pI, molecular weight, and cross-reactivity with specific antiserum. The known biochemical properties of L-plastin suggest it may be involved in regulating adhesion of LAK to tumor targets. The protein tyrosine kinase-specific inhibitor Herb A did not block p65 phosphorylation, but blocked LAK killing of multiple tumor targets at a post-binding stage. Greater than 50% inhibition of cytotoxicity was observed after a 2.5-h pretreatment with 0.125 $\mu$g/ml Herb A. Inhibition occurred over a period in pretreatment which LAK were not dependent upon IL-2 for maintenance of killing activity, supporting the conclusion that the drug interfered with mobilization of cytotoxic function. Granule exocytosis measured by BLT-esterase release from LAK occurred after coincubation with tumors, and was inhibited by Herb A LAK cytotoxicity was dependent upon extracellular calcium, suggesting that granule exocytosis rather than Fas ligand was the principal pathway leading to target cell death. The data indicate that protein tyrosine kinases play a pivotal role in LAK cytolytic function by regulating granule exocytosis, and that tumor targets can activate an adhesion dependent Ser kinase pathway in LAK resulting in phosphorylation of L-plastin. ^