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Timothy P. Hughes

Other affiliations: University of Colorado Denver
Bio: Timothy P. Hughes is an academic researcher from University of Maryland, Baltimore. The author has contributed to research in topics: ABO blood group system & Vaccination. The author has an hindex of 7, co-authored 9 publications receiving 1410 citations. Previous affiliations of Timothy P. Hughes include University of Colorado Denver.

Papers
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Journal ArticleDOI
TL;DR: Two strains of Campylobacter jejuni ingested by 111 adult volunteers, in doses ranging from 8 x 10(2) to 2x 10(9) organisms, caused diarrheal illnesses that indicates that the pathogenesis of C.Jejuni infection includes tissue inflammation.
Abstract: Two strains of Campylobacter jejuni ingested by 111 adult volunteers, in doses ranging from 8 x 10(2) to 2 x 10(9) organisms, caused diarrheal illnesses. Rates of infection increased with dose, but development of illness did not show a clear dose relation. Resulting illnesses with strain A3249 ranged from a few loose stools to dysentery, with an average of five diarrheal stools and a volume of 509 mL. Infection with strain 81-176 was more likely to cause illness, and these illnesses were more severe, with an average of 15 stools and 1484 mL of total stool volume. All patients had fecal leukocytes. The dysenteric nature of the illness indicates that the pathogenesis of C. jejuni infection includes tissue inflammation. Ill volunteers developed a serum antibody response to the C. jejuni group antigen and were protected from subsequent illness but not infection with the same strain.

1,129 citations

Journal ArticleDOI
TL;DR: While no correlation was found between HLA type and severity of cholera, these results do support the claims of other investigators that blood group O is found more frequently in patients with severe cholERA than in the normal population.
Abstract: In the course of studies of immunity to experimental cholera in man, 10(5) or 10(6) Vibrio cholerae were given to 66 college students and other community volunteers under quarantine in an isolation ward. HLA antigen and blood group determinations were carried out to test the hypothesis that severity of clinical cholera is dependent in part upon genetically-determined host susceptibility. Fifty-five volunteers developed diarrhoea; 38 had mild illness and 17 had severe cholera (stool volume greater than or equal to 5.0 litres). HLA antigens were found in similar frequency in volunteers with severe, mild or no diarrhoea; antigen A1, A2, A3 and B7 were most common. Blood group O, however, was found in 64% of persons with severe cholera versus 36-38% of volunteers with mild or absent illness. Thus, while no correlation was found between HLA type and severity of cholera, these results do support the claims of other investigators that blood group O is found more frequently in patients with severe cholera than in the normal population.

79 citations

Journal ArticleDOI
TL;DR: Seven enterotoxigenic and three enteropathogenic strains of E. coli that have been used in volunteer challenge studies were tested for CFA/I, C FA/II, and type 1 somatic pili after culture on solid agar and in broth and it was found that none of them caused diarrhea in humans.
Abstract: Controversy exists as to whether all strains of enterotoxigenic Escherichia coli must possess colonization factor antigen pili I or II (CFA/I, CFA/II) in order to be virulent for humans. Failure to detect CFA/I or CFA/II in enterotoxigenic strains from human diarrhea has been explained by some as due to plasmid loss and by others as evidence that CFA/I and CFA/II pili are not prerequisites for human virulence in all enterotoxigenic strains of E. coli. Seven enterotoxigenic and three enteropathogenic strains of E. coli that have been used in volunteer challenge studies were tested for CFA/I, CFA/II, and type 1 somatic pili after culture on solid agar and in broth. Six of the seven enterotoxigenic and two of the three enteropathogenic strains caused diarrhea in humans. Of these eight virulent strains, one produced CFA/I, and one had CFA/II. Threre remained four enterotoxigenic and two enteropathogenic strains that unequivocally caused diarrhea while lacking CFA/I or CFA/II. In such strains other organelles or surface properties must be operative to promote adhesion to and colonization of small intestinal mucosa. CFA/I and CFA/II are not prerequisites of virulence for all E. coli strains that cause diarrhea in humans.

66 citations

Journal ArticleDOI
TL;DR: The hyperkalemia reported by Kahn and Blum may have resulted from excessive GES administration, without a source of free water, to infants having few diarrheal stools, irrespective of etiology.

65 citations

Journal ArticleDOI
TL;DR: The formalin-inactivated vaccine provided only partial protection against Rocky Mountain spotted fever but ameliorated the illness.
Abstract: A new formalin-inactivated vaccine prepared by sucrose density gradient centrifugation of tissue culture-grown Rickettsia rickettsii was evaluated for safety and immunogenicity in a placebo-controlled, double-blind study. Most of the 52 seronegative adult vaccinees, 88% after the first and 66% after the second dose, experienced brief, mild (mostly local) reactions, but only 50% exhibited a systemic immune response to vaccination. Six unvaccinated volunteers (controls) and 16 of these vaccinees were challenged with R rickettsii one month after vaccination. Vaccine efficacy was 25%; all six controls and 12 of 16 vaccinees developed typical Rocky Mountain spotted fever. The incubation period was longer, the duration of constitutional symptoms shorter, and the height of fever lower in ill vaccinees than in controls. The vaccine provided only partial protection against Rocky Mountain spotted fever but ameliorated the illness.

40 citations


Cited by
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Journal ArticleDOI
TL;DR: Concepts and methodologies concerning, and guidelines for measuring, social class and other aspects of socioeconomic position (e.g. income, poverty, deprivation, wealth, education) are discussed.
Abstract: Increasing social inequalities in health in the United States and elsewhere, coupled with growing inequalities in income and wealth, have refocused attention on social class as a key determinant of population health. Routine analysis using conceptually coherent and consistent measures of socioeconomic position in US public health research and surveillance, however, remains rare. This review discusses concepts and methodologies concerning, and guidelines for measuring, social class and other aspects of socioeconomic position (e.g. income, poverty, deprivation, wealth, education). These data should be collected at the individual, household, and neighborhood level, to characterize both childhood and adult socioeconomic position; fluctuations in economic resources during these time periods also merit consideration. Guidelines for linking census-based socioeconomic measures and health data are presented, as are recommendations for analyses involving social class, race/ethnicity, and gender. Suggestions for research on socioeconomic measures are provided, to aid monitoring steps toward social equity in health.

2,490 citations

Book
01 Jan 1993
TL;DR: In this article, the authors investigated the effect of nutrition on stress and immunity in dairy cows and discussed the potential applications of GM technology on pig performance and piglet starter feeding in a changing business environment, with special emphasis on tryptophan and valine.
Abstract: Preface * Fatty acids and fertility in dairy cows * Environmental and genetic influences on successful heifer rearing * Reducing dietary phosphorus inputs within dairy systems * Practical aspects of feeding grass to dairy cows * Practical considerations of feed evaluation systems for dairy cows * Adapting livestock production systems to climate change * Legislation affecting animal production systems * Mycotoxin issues in farm animals and strategies to reduce mycotoxins in animal feeds * The effect of nutrition on stress and immunity * Potential applications of GM technology * Influence of feed processing technology on pig performance * Piglet starter feeding in a changing business environment * Organic acids in pig diets * Amino acid requirements in piglets with special emphasis on tryptophan and valine * Factors affecting pork quality * List of participants * Index

1,592 citations

Journal ArticleDOI
TL;DR: Infection with Campylobacter jejuni is one of the most common causes of gastroenteritis worldwide; it occurs more frequently than do infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7.
Abstract: Infection with Campylobacter jejuni is one of the most common causes of gastroenteritis worldwide; it occurs more frequently than do infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7. In developed countries, the incidence of Campylobacter jejuni infections peaks during infancy and again during early adulthood. Most infections are acquired by the consumption and handling of poultry. A typical case is characterized by diarrhea, fever, and abdominal cramps. Obtaining cultures of the organism from stool samples remains the best way to diagnose this infection. An alarming recent trend is the rapid emergence of antimicrobial agent--resistant Campylobacter strains all over the world. Use of antibiotics in animals used for food has accelerated this trend. It is fortunate that complications of C. jejuni infections are rare, and most patients do not require antibiotics. Guillain-Barre syndrome is now recognized as a post-infectious complication of C. jejuni infection, but its incidence is <1 per 1000 infections. Careful food preparation and cooking practices may prevent some Campylobacter infections.

1,165 citations

Journal ArticleDOI
TL;DR: Foodborne outbreaks associated with fresh produce in the United States have increased in absolute numbers and as a proportion of all reported foodborne outbreaks, and Cyclospora and Escherichia coli O157:H7 were newly recognized as causes of foodborne illness.

1,061 citations