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1.
J Anim Sci ; 93(1): 433-41, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25568385

ABSTRACT

A survey was conducted from November 2009 to April 2010 to determine how importers of pork define 7 predetermined quality categories (food safety, customer service, eating quality, product specification, packaging, visual characteristics, and production history) and to estimate willingness-to-pay (WTP) and establish best-worst (B/W) scaling (rank) for the 7 quality categories. Interviews were conducted in Hong Kong/China (n = 83), Japan (n = 48), Mexico (n = 70) and Russia (n = 54) with importers of U.S. pork or those who had purchased U.S. pork from distributors in the last 3 yr. Interviews used dynamic routing software and were structured such that economic factors for purchase were addressed first, allowing all responses to focus on quality. Questions about WTP and B/W were asked and then each respondent was asked to define what each quality category meant to them. Generalized linear mixed models were used to analyze frequency data. Over 70% of interviewees in Hong Kong/China, Japan, and Mexico responded that purchase price was influential in deciding whether or not to purchase imported pork. This number was lower in Russia, where respondents stated tariff rates were also important, indicating market access was a larger issue in Russia. Food safety was the most important quality category (price was not included as a part of quality) for imported pork followed by specifications. Respondents indicated some form of government inspection was how they defined food safety, whereas product size, weight, and subcutaneous fat were all included in the definition of specifications. Interviewees were more likely to pay premiums for customer service and less likely to pay premiums for packaging (P < 0.05). The premiums that were willing to be paid for guarantees of quality for imported pork variety meats were numerically lower than for whole muscle cuts or processed products. A guarantee associated with food safety of processed pork products was found to be the quality attribute for which importers would be willing to pay the highest premium. Production history was found to be the least important quality attribute for importers of all types of U.S. pork, except those in Japan. Exporters could increase profitability if a guarantee of customer service was made. Price, tariffs, and exchange rates are important to pork importers; these results indicated that if certain quality attributes could be guaranteed, exporters could increase profitability.


Subject(s)
Commerce , Meat/economics , Meat/standards , Animals , Asia , Mexico , Swine , United States
2.
J Anim Sci ; 91(12): 5981-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24166999

ABSTRACT

Fifty-four stores in 30 U.S. cities were sampled from June 2011 through May 2012 to benchmark beef tenderness at retail, as assessed by Warner-Bratzler shear force (WBSF). Top loin (Longissimus dorsi; n = 980) and sirloin (Gluteus medius and Biceps femoris; n = 860) steaks were collected at random (Quality Grade and brand) and shipped via overnight delivery to Colorado State University. From June 2011 through November 2011, North American Beef Tenderness Survey (NABTS) Period 1, samples were shipped fresh and then frozen. Mean WBSF values during Period 1 were 2.9 and 3.5 kg for top loin and sirloin steaks, respectively. Frequencies of steaks classified as tough (WBSF ≥ 4.4 kg) were 8.6% and 17.7% for top loin and sirloin steaks, respectively. When shipped fresh, a disproportionately high frequency (16.9%) of top loin steaks had WBSF ≤ 2.0 kg, representing a deviation from previous works. Two trials were conducted to assess the effect of freezing, retail display, and shipping on WBSF and slice shear force (SSF) of beef top loin steaks. Freezing, retail display, and shipment reduced WBSF by 0.4, 0.3, and 0.0 kg during Trial 1, and by 0.4, 0.3, and 0.1 kg during Trial 2. Slice shear force was lower (P < 0.05) in steaks exposed to shipping conditions during Trial 1; however, this difference was not observed in Trial 2. Shipping decreased the frequency of steaks categorized as tough (SSF ≥ 20.0 kg) from 11.1 to 5.7% and from 30.5 to 28.6%, during Trial 1 and 2, respectively. During Trial 1, WBSF indicated that shipping increased incidence of tough samples from 0.0 to 3.8%, but this trend was reversed during Trial 2 when shipping reduced incidence of tough samples from 13.0 to 5.6%. Coefficients of variation for treatment effects suggested variance remained unchanged (± 2.0%), with respect to shear force values. However, mean values were reduced as a result of shipping conditions. These findings dictated a change in NABTS protocol from December 2011 through May 2012 (Period 2), during which time samples were shipped frozen. Mean WBSF values were 3.4 and 4.0 kg for top loin and sirloin samples, respectively. Frequencies of steaks classified as tough were 14% and 23.5% for top loin and sirloin steaks, respectively. These findings suggest that freezing samples before shipment may influence shear force of steaks collected at the retail level. These data should be considered when evaluating beef tenderness surveys and in the design of future works.


Subject(s)
Meat/standards , Animals , Cattle , Food Handling/methods , Freezing , Shear Strength
3.
J Anim Sci ; 91(4): 1907-19, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23408805

ABSTRACT

The National Beef Quality Audit (NBQA)-2011 benchmarked the current status of and assessed progress being made toward quality and consistency of U.S. cattle, carcasses, and beef products after the completion of the first NBQA in 1991. Unlike previous NBQA, objectives of the 2011 Phase I study were to determine how each beef market sector defined 7 quality categories, estimate willingness-to-pay (WTP) for the same quality categories by market sector, and establish a best-worst (B/W) scaling for the quality categories. Structured face-to-face interviews were conducted and responses were recorded using dynamic routing software over an 11-mo period (February to December 2011) with decision makers in each of the following beef market sectors: Feeders (n = 59), Packers (n = 26), Food Service, Distribution, and Further Processors (n = 48), Retailers (n = 30), and Government and Allied Industries (n = 47). All respondents participated in a structured interview consisting of WTP and B/W questions that were tied to 7 quality categories and then were asked to "define" each of the 7 categories in terms of what the category meant to them, resulting in completely unbiased results. The 7 quality categories were a) how and where the cattle were raised, b) lean, fat, and bone, c) weight and size, d) cattle genetics, e) visual characteristics, f) food safety, and g) eating satisfaction. Overall, "food safety" and "eating satisfaction" were the categories of greatest and second most importance, respectively, to all beef market sectors except for Feeders. Feeders ranked "how and where the cattle were raised" and "weight and size" as the most important and second most important, respectively. Overall, "how and where the cattle were raised" had the greatest odds of being considered a nonnegotiable requirement before the raw material for each sector would be considered for purchase and was statistically more important (P < 0.05) as a requirement for purchase than all other categories except "food safety." When all market sectors were considered, "eating satisfaction" was shown to generate the greatest average WTP percentage premium (11.1%), but that WTP premium value only differed statistically (P < 0.05) from "weight and size" (8.8%). Most notably, when a sector said that "food safety" was a nonnegotiable requirement, no sector was willing to purchase the product at a discounted price if the "food safety" of the product could not be assured.


Subject(s)
Meat-Packing Industry/standards , Meat/standards , Animal Husbandry/economics , Animal Husbandry/standards , Animals , Cattle , Food Quality , Food-Processing Industry/economics , Food-Processing Industry/standards , Marketing/standards , Meat/economics , Meat-Packing Industry/economics , United States
4.
J Anim Sci ; 90(13): 5143-51, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952369

ABSTRACT

The 2011 National Beef Quality Audit (NBQA-2011) assessed the current status of quality and consistency of fed steers and heifers. Beef carcasses (n = 9,802), representing approximately 10% of each production lot in 28 beef processing facilities, were selected randomly for the survey. Carcass evaluation for the cooler assessment of this study revealed the following traits and frequencies: sex classes of steer (63.5%), heifer (36.4%), cow (0.1%), and bullock (0.03%); dark cutters (3.2%); blood splash (0.3%); yellow fat (0.1%); calloused rib eye (0.05%); overall maturities of A (92.8%), B (6.0%), and C or greater (1.2%); estimated breed types of native (88.3%), dairy type (9.9%), and Bos indicus (1.8%); and country of origin of United States (97.7%), Mexico (1.8%), and Canada (0.5%). Certified or marketing program frequencies were age and source verified (10.7%), ≤A(40) (10.0%), Certified Angus Beef (9.3%), Top Choice (4.1%), natural (0.6%), and Non-Hormone-Treated Cattle (0.5%); no organic programs were observed. Mean USDA yield grade (YG) traits were USDA YG (2.9), HCW (374.0 kg), adjusted fat thickness (1.3 cm), LM area (88.8 cm2), and KPH (2.3%). Frequencies of USDA YG distributions were YG 1, 12.4%; YG 2, 41.0%; YG 3, 36.3%; YG 4, 8.6%; and YG 5, 1.6%. Mean USDA quality grade (QG) traits were USDA quality grade (Select(93)), marbling score (Small(40)), overall maturity (A(59)), lean maturity (A(54)), and skeletal maturity (A(62)). Frequencies of USDA QG distributions were Prime, 2.1%; Choice, 58.9%; Select, 32.6%; and Standard or less, 6.3%. Marbling score distribution was Slightly Abundant or greater, 2.3%; Moderate, 5.0%; Modest, 17.3%; Small, 39.7%; Slight, 34.6%; and Traces or less, 1.1%. Carcasses with QG of Select or greater and YG 3 or less represented 85.1% of the sample. This is the fifth benchmark study measuring targeted carcass characteristics, and information from this survey will continue to help drive progress in the beef industry. Results will be used in extension and educational programs as teaching tools to inform beef producers and industry professionals of the current state of the U.S. beef industry.


Subject(s)
Body Composition , Cattle/physiology , Marketing , Meat-Packing Industry/standards , Meat/standards , Analysis of Variance , Animals , Cattle/anatomy & histology , Female , Least-Squares Analysis , Male , United States
5.
J Anim Sci ; 90(13): 5135-42, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22952370

ABSTRACT

The National Beef Quality Audit-2011 (NBQA-2011) was conducted to assess targeted characteristics on the harvest floor that affect the quality and value of cattle, carcasses, and byproducts. Survey teams evaluated approximately 18,000 cattle/carcasses between May and November 2011 in 8 beef processing facilities. Cattle identification methods were lot visual tags (85.7%), individual visual tags (50.6%), electronic tags (20.1%), metal-clip tags (15.7%), other (5.3%), none (2.5%), and wattles (0.5%). Hide colors or breed types were black (61.1%), red (12.8%), yellow (8.7%), Holstein (5.5%), brown (5.0%), gray (5.0%), white (1.4%), and brindle (1.0%). Brand frequencies were none (55.2%), 1 (40.4%), 2 (4.4%), and 3 or more (0.04%) brands, and brands were located on the butt (35.2%), side (9.0%), and shoulder (2.5%). Hide locations of mud or manure were no mud/manure (49.2%), legs (36.8%), belly (23.7%), side (14.9%), top-line (11.0%), and tail region (13.7%). There were 76.2% of cattle without horns, and the majority of those with horns (71.6%) were between 0 cm and 12.7 cm in length. Permanent incisor numbers were zero (87.3%), 1 (1.4%), 2 (8.0%), 3 (0.9%), 4 (1.9%), 5 (0.3%), 6 (0.2%), 7 (0.1%), and 8 (0.02%). Most carcasses (77.0%) were not bruised, 18.7% had 1 bruise, 3.4% had 2 bruises, 0.6% had 3 bruises, and 0.3% had more than 3 bruises. Bruise locations were loin (50.1%), rib (21.3%), chuck (13.8%), round (7.3%), and brisket/flank/plate (7.5%). Condemnation item and incidence were whole carcass (none recorded), liver (20.9%), lungs (17.3%), tongue (10.0%), viscera (9.3%), and head (7.2%). Compared with the NBQA-2005, the NBQA-2011 had an increased percentage of black-hided cattle (56.3 vs. 61.1%), more cattle with brands (38.7 vs. 44.8%), and more cattle with some form of identification (93.3 vs. 97.5%). In addition, there was a lesser percentage of carcasses with bruising in 2011 (23.0%) than in 2005 (35.2%), as well as a smaller percentage of carcasses with more than 1 bruise (2005 = 9.4% vs. 2011 = 4.2%). Compared with the 2005 audit, a similar percentage of the cattle were deemed 30 mo of age or older using dentition (2005 = 2.7% vs. 2011 = 3.3%). The information from NBQA-2011 helps the beef industry measure progress against previous NBQA assessments and provides a benchmark for future educational and research activities.


Subject(s)
Body Composition , Cattle/physiology , Meat-Packing Industry/standards , Meat/standards , Analysis of Variance , Animal Identification Systems , Animals , Cattle/anatomy & histology , Female , Least-Squares Analysis , Male , Manure/analysis , Meat Products/standards , United States
6.
J Anim Sci ; 89(3): 792-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21346138

ABSTRACT

Anabolic steroid implants are commonly used to increase growth performance and carcass leanness. The objective of this study was to determine the effects of various trenbolone acetate implants on Warner-Bratzler shear force (WBSF), slice shear force, and consumer palatability ratings for USDA Choice and Select beef strip steaks aged for 14 and 21 d from cattle implanted before slaughter. Beef steers (n = 1,740) were subjected to the following treatments: 1) nonimplanted control (CON); 2) Revalor-IS on d 0 and Revalor-S on d 70 (IS/S); or 3) Revalor-XS (RXS) on d 0, and were randomly assigned to pens within blocks. A subsample of USDA Choice (n = 82) and USDA Select (n = 81) carcasses was selected. Strip loins from these carcasses were collected, and steaks measuring 2.54 cm were fabricated and aged for 14 or 21 d postmortem. Select steaks aged 14 d from RXS cattle had decreased (P < 0.05) WBSF values compared with IS/S steaks, but CON steaks did not differ from either implant treatment. Warner-Bratzler shear force did not differ among treatments (P > 0.05) from USDA Choice steaks aged 14 and 21 d or from Select steaks aged 21 d. Consumer scores for flavor and overall liking for USDA Choice 14-d aged RXS steaks were less (P < 0.05) than CON steaks; however, there were no differences between RXS, IS/S, and CON for tenderness or juiciness, or for tenderness and overall acceptability. Select steaks aged 14 d from IS/S cattle had less (P < 0.05) tenderness, tenderness acceptability, overall acceptability, overall liking, juiciness, and flavor scores than RXS and CON steaks; however, consumers also rated RXS steaks less for tenderness, juiciness, and tenderness acceptability when compared with CON steaks. Consumer scores for overall liking, flavor, and tenderness for USDA Choice steaks aged 21 d from RXS, IS/S, and CON did not differ. However, implant affected (P < 0.05) overall liking, flavor, juiciness, and tenderness for USDA Select steaks aged 21 d. Even so, there were no differences between RXS, IS/S, and CON steaks for tenderness or overall acceptability for steaks aged 21 d, regardless of quality grade. Results indicated that tenderness differences exist among implant strategies when strip steaks were aged 14 d; however, tenderness and overall consumer acceptability were only influenced by implant in Select steaks aged 14 d. Furthermore, aging for 21 d can minimize and even eliminate implant differences in WBSF and slice shear force, as well as tenderness and overall consumer acceptability.


Subject(s)
Estrogens/pharmacology , Food Handling/methods , Meat/standards , Trenbolone Acetate/pharmacology , Animals , Cattle , Consumer Behavior , Delayed-Action Preparations , Drug Implants , Estrogens/administration & dosage , Humans , Time Factors , Trenbolone Acetate/administration & dosage
7.
Nig Q J Hosp Med ; 20(4): 181-5, 2010.
Article in English | MEDLINE | ID: mdl-21913525

ABSTRACT

BACKGROUND: There has been considerable escalation in the incidence of HIV infection in Papua New Guinea since the first cases have been reported in 1987. OBJECTIVES: The study was to identify the genetic subtype in HIV infected patients in Papua New Guinea. It is believed that the result will not only assist in tracing and tracking the sources of the infection, but will also help to evaluate the impact of the genotypes on the natural history of HIV in Papua New Guinea. METHODS: Plasma samples from eighty patients were definitively tested for HIV antibodies at PNG Central Public Health Laboratory using Welcome ELISA, Serodia, Immuno Comb and Hexagon. The samples were also tested for Hepatitis B (HBsAG and HBcAG) and Hepatitis C virus antibodies. The HIV positive samples were reconfirmed by the Western Blot analysis; RNA isolation and reverse transcription. DNA sequencing and phylogenetic analysis and determination of HIV subtypes were determined by using representative sequences A-H, J, N and 0 in the Los Alamos Database. RESULTS: The total number of HIV-1 positive patients' samples was 20 (5 females and 15 males) Out of this, 11 (all males) were successfully subtyped as c (91%) and b (9%) showing the predominant type to be subtype C. Nine isolates were designated not typable. This is attributable to either low viral load or new emerging strains that could not be detected by the database used in phylogenetic analysis. CONCLUSION: Data predicts that there is possible emergence of BC circulating recombinant form (CRF) because we also identified subtype B. We suggest that as subtype C remains a guide for tracking the sources of infection in PNG that both subtypes C and B (and any other subtypes that may be identified in future) be included in the future vaccine for use in Papua New Guinea since some potential vaccines work only against particular subtypes assuming that nearly all subtypes identified so far are responsive to ant-retroviral drugs.


Subject(s)
DNA, Viral/genetics , HIV Infections/genetics , HIV-1/genetics , HIV-1/isolation & purification , Adolescent , Adult , Base Sequence , Child , DNA, Viral/analysis , Female , Genotype , HIV Infections/epidemiology , HIV Infections/virology , HIV-1/classification , Humans , Incidence , Male , Middle Aged , Molecular Sequence Data , Papua New Guinea/epidemiology , Phylogeny , Polymerase Chain Reaction , Population Surveillance , Reverse Transcription , Socioeconomic Factors , Viral Load , Young Adult
8.
J Biol Chem ; 276(16): 13025-33, 2001 Apr 20.
Article in English | MEDLINE | ID: mdl-11278876

ABSTRACT

The ferric siderophore transporters of the Gram-negative bacterial outer membrane manifest a unique architecture: Their N termini fold into a globular domain that lodges within, and physically obstructs, a transmembrane porin beta-barrel formed by their C termini. We exchanged and deleted the N termini of two such siderophore receptors, FepA and FhuA, which recognize and transport ferric enterobactin and ferrichrome, respectively. The resultant chimeric proteins and empty beta-barrels avidly bound appropriate ligands, including iron complexes, protein toxins, and viruses. Thus, the ability to recognize and discriminate these molecules fully originates in the transmembrane beta-barrel domain. Both the hybrid and the deletion proteins also transported the ferric siderophore that they bound. The FepA constructs showed less transport activity than wild type receptor protein, but the FhuA constructs functioned with turnover numbers that were equivalent to wild type. The mutant proteins displayed the full range of transport functionalities, despite their aberrant or missing N termini, confirming (Braun, M., Killmann, H., and Braun, V. (1999) Mol. Microbiol. 33, 1037-1049) that the globular domain within the pore is dispensable to the siderophore internalization reaction, and when present, acts without specificity during solute uptake. These and other data suggest a transport process in which siderophore receptors undergo multiple conformational states that ultimately expel the N terminus from the channel concomitant with solute internalization.


Subject(s)
Bacterial Outer Membrane Proteins/chemistry , Bacterial Outer Membrane Proteins/metabolism , Carrier Proteins/chemistry , Carrier Proteins/metabolism , Escherichia coli Proteins , Escherichia coli/metabolism , Porins/metabolism , Receptors, Cell Surface , Receptors, Virus/chemistry , Receptors, Virus/metabolism , Enterobactin/metabolism , Escherichia coli/genetics , Ferrichrome/metabolism , Genotype , Kinetics , Ligands , Models, Molecular , Polymerase Chain Reaction , Porins/chemistry , Protein Structure, Secondary , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/metabolism , Sequence Deletion
9.
Nihon Koshu Eisei Zasshi ; 47(5): 421-9, 2000 May.
Article in Japanese | MEDLINE | ID: mdl-10860388

ABSTRACT

The present study was undertaken to develop a self-scoring system which can be used by a resident to check lifestyle. The oral health scoring system which we used in Tobishima village, Aichi-ken, was named SAWAYAKA score. A total of 777 subjects were examined. The subjects responded to a questionnaire regarding their past individual lifestyles and dietary habits. Oral health conditions were also examined by dentists. The odds ratio and 95% confidence interval were calculated both from retained tooth numbers and the questionnaire. Questions with significant odds ratio were selected and the partial regression coefficients of quantification II method by Hayashi were calculated. The results are as follows; 1) Eleven questions showed a significant odds ratio between retained tooth numbers and past lifestyle and dietary habits. The questions involved the frequency of snack intake, tooth brushing frequency, having own tooth brush, smoking, drinking, having a hobby, having a family dentist, consulting a dentist before a problem got serious, gum bleeding, swollen gums and toothache caused by sensitivity to cold water. 2) The eleven items were analysed by using Hayashi's quantification II method. 3) The results showed that unswollen gums affected the retention of teeth by the range of 1.240. Toothache caused by sensitivity to cold water affected the retention of teeth by the range of 0.765. Having a hobby affected the retention of teeth by the range of 0.691. 4) The "SAWAYAKA" score was used to select important items, excluding drinking. 5) When results were analysed with the SAWAYAKA score, an average of 9.6 was obtained. It was concluded that the scoring list could be used for checking resident's lifestyles, and for promoting the preservation of more than 20 teeth at the age of 80.


Subject(s)
Oral Health , Adult , Aged , Feeding Behavior , Female , Humans , Life Style , Male , Middle Aged , Surveys and Questionnaires
10.
Mol Microbiol ; 32(6): 1153-65, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10383757

ABSTRACT

The siderophore ferric enterobactin enters Escherichia coli through the outer membrane (OM) porin FepA, which contains an aqueous transmembrane channel that is normally occluded by other parts of the protein. After binding the siderophore at a site within the surface loops, FepA undergoes conformational changes that promote ligand internalization. We assessed the participation of different loops in ligand recognition and uptake by creating and analysing a series of deletions. We genetically engineered 26 mutations that removed 9-75 amino acids from nine loops and two buried regions of the OM protein. The mutations had various effects on the uptake reaction, which we discerned by comparing the substrate concentrations of half-maximal binding (Kd) and uptake (Km): every loop deletion affected siderophore transport kinetics, decreasing or eliminating binding affinity and transport efficiency. We classified the mutations in three groups on the basis of their slight, strong or complete inhibition of the rate of ferric enterobactin transport across the OM. Finally, characterization of the FepA mutants revealed that prior experiments underestimated the affinity of FepA for ferric enterobactin: the interaction between the protein and the ferric siderophore is so avid (Kd < 0.2 nM) that FepA tolerated the large reductions in affinity that some loop deletions caused without loss of uptake functionality. That is, like other porins, many of the loops of FepA are superficially dispensable: ferric enterobactin transport occurred without them, at levels that allowed bacterial growth.


Subject(s)
Bacterial Outer Membrane Proteins/metabolism , Carrier Proteins/metabolism , Enterobactin/metabolism , Receptors, Cell Surface/metabolism , Amino Acid Sequence , Bacterial Outer Membrane Proteins/genetics , Bacterial Outer Membrane Proteins/physiology , Biological Transport , Carrier Proteins/genetics , Carrier Proteins/physiology , Colicins/metabolism , Molecular Sequence Data , Mutagenesis, Site-Directed , Receptors, Cell Surface/genetics , Receptors, Cell Surface/physiology , Sequence Deletion
11.
ASDC J Dent Child ; 65(5): 330-4, 355, 1998.
Article in English | MEDLINE | ID: mdl-9795737

ABSTRACT

This study was undertaken to clarify whether the salivary fluoride concentration on the anterior and premolar teeth, released from an orthodontic bonding material, differed between openbite and non-openbite patients. Using fluoride-releasing bonding materials, brackets were bonded to the teeth in openbite and in non-openbite patients. Saliva films on the tooth surfaces near the brackets were collected with filter paper and fluoride concentrations in the saliva were determined by using a fluoride electrode technique. Saliva was collected and analyzed at different periods after the bonding. Fluoride concentrations in the saliva increased sharply immediately after bonding, decreased gradually thereafter, then leveled off. Fluoride concentrations in the saliva on the tooth surfaces were higher in openbite patients for one day to as long as one week. The results of the two-way analysis (ANOVA) showed that the differences in the overbite factor (openbite, non-openbite) contributed to the variances the most (p < 0.001; contribution, 59.50 percent after one day and p < 0.01; contribution, 49.63 percent after 3 days). In conclusion, the fluoride released from the bonding materials on the tooth surfaces was retained more in openbite than in non-openbite patients, suggesting their lower flow rate of saliva.


Subject(s)
Adhesives/chemistry , Cariostatic Agents/chemistry , Dental Bonding , Dental Cements/chemistry , Fluorides/chemistry , Malocclusion/therapy , Orthodontic Brackets , Analysis of Variance , Cariostatic Agents/analysis , Child , Female , Fluorides/analysis , Follow-Up Studies , Humans , Ion-Selective Electrodes , Male , Mandible , Maxilla , Mouth Breathing/physiopathology , Saliva/chemistry , Saliva/metabolism , Secretory Rate , Time Factors
12.
J Biol Chem ; 272(35): 21950-5, 1997 Aug 29.
Article in English | MEDLINE | ID: mdl-9268330

ABSTRACT

The Escherichia coli FepA protein is an energy- and TonB-dependent, ligand-binding porin that functions as a receptor for the siderophore ferric enterobactin and colicins B and D. We characterized the kinetic and thermodynamic parameters associated with the initial, energy-independent steps in ligand binding to FepA. In vivo experiments produced Kd values of 24, 185, and 560 nM for ferric enterobactin, colicin B, and colicin D, respectively. The siderophore and colicin B bound to FepA with a 1:1 stoichiometry, but colicin D bound to a maximum level that was 3-fold lower. Preincubation with ferric enterobactin prevented colicin B binding, and preincubation with colicin B prevented ferric enterobactin binding. Colicin B release from FepA was unexpectedly slow in vivo, about 10-fold slower than ferric enterobactin release. This slow dissociation of the colicin B.FepA complex facilitated the affinity purification of FepA and FepA mutants with colicin B-Sepharose. Analysis of a fluorescent FepA derivative showed that ferric enterobactin and colicin B adsorbed with biphasic kinetics, suggesting that both ligands bind in at least two distinct steps, an initial rapid stage and a subsequent slower step, that presumably establishes a transport-competent complex.


Subject(s)
Bacterial Outer Membrane Proteins/metabolism , Carrier Proteins/metabolism , Ion Channels/metabolism , Iron/metabolism , Receptors, Cell Surface/metabolism , Binding, Competitive , Chromatography, Affinity , Colicins/metabolism , Detergents , Enterobactin/metabolism , Kinetics , Ligands , Octoxynol , Protein Binding
13.
Proc Natl Acad Sci U S A ; 94(9): 4560-5, 1997 Apr 29.
Article in English | MEDLINE | ID: mdl-9114029

ABSTRACT

Siderophores and colicins enter bacterial cells through TonB-dependent outer membrane proteins. Using site-directed substitution mutagenesis, we studied ligand recognition by a prototypic Escherichia coli siderophore receptor, FepA, that binds the iron chelate ferric enterobactin and colicins B and D. These genetic experiments identified a common binding site for two of the three ligands, containing multiple positive charges, within cell surface residues of FepA. Elimination of single residues in this region did not impair the adsorption or transport of ferric enterobactin, but double mutagenesis in the charge cluster identified amino acids (Arg-286 and Arg-316) that participate in siderophore binding and function in FepA-mediated killing by colicins B and D. Ferric enterobactin binding, furthermore, prevented covalent modification of FepA within this domain by either a fluorescent probe or an arginine-specific reagent, corroborating the involvement of this site in ligand recognition. These results identify, for the first time, residues in a TonB-dependent outer membrane protein that participate in ligand binding. They also explain the competition between ferric enterobactin and the colicins on the bacterial cell surface: all three ligands interact with the same arginine residues within FepA during their penetration through the outer membrane.


Subject(s)
Bacterial Outer Membrane Proteins/metabolism , Carrier Proteins/metabolism , Colicins/metabolism , Enterobactin/metabolism , Receptors, Cell Surface/metabolism , Siderophores/metabolism , Amino Acid Sequence , Arginine/genetics , Bacterial Outer Membrane Proteins/genetics , Binding Sites/genetics , Biological Transport , Carrier Proteins/genetics , DNA Mutational Analysis , Molecular Sequence Data , Mutagenesis, Site-Directed , Receptors, Cell Surface/genetics , Sequence Homology, Amino Acid
14.
P N G Med J ; 39(3): 181-2, 1996 Sep.
Article in English | MEDLINE | ID: mdl-9795559

ABSTRACT

PIP: By mid-1995, a total of 308 HIV cases had been reported in Papua New Guinea. The majority (74%) of these cases were diagnosed in Port Moresby. This article describes the clinical characteristics of HIV infection in 67 adults who presented to Port Moresby General Hospital in 1990-95. The median age at presentation was 27 years in men and 28 years in women, with an equal distribution of cases by sex. The major presenting symptoms were wasting and weight loss exceeding 10% of body weight (94%), chronic diarrhea (47%), prolonged fever (77%), and oropharyngeal candidiasis (66%). Pulmonary tuberculosis was diagnosed on the basis of chest X-ray and history in 37 patients (56%), but only 3 had sputum positive for acid-fast bacilli. Anemia was present in 75%. 65 patients (97%) fulfilled the World Health Organization criteria for AIDS. The inpatient mortality rate in this series was 43%, and 13 of these 29 patients died within a month of their first presentation.^ieng


Subject(s)
HIV Infections/diagnosis , Acquired Immunodeficiency Syndrome/diagnosis , Acquired Immunodeficiency Syndrome/epidemiology , Adolescent , Adult , Black People , Female , HIV Infections/epidemiology , Humans , Incidence , Male , Papua New Guinea/epidemiology , Risk Factors
15.
Trans R Soc Trop Med Hyg ; 90(1): 57-60, 1996.
Article in English | MEDLINE | ID: mdl-8730314

ABSTRACT

Eleven cases of cryptococcal meningitis were diagnosed and biotyped from September 1991 to August 1992 in Papua New Guinea (PNG). Seven isolates were Cryptococcus neoformans var. gattii from paediatric and adult patients, one with diabetes mellitus and 4 were C. neoformans var. neoformans from adults, of whom 2 had human immunodeficiency virus type 1 (HIV-1) infection, and one each had tuberculosis and Plasmodium vivax malaria. Significant clinical findings were headache, fever, meningism, vomiting, photophobia, papilloedema and cranial nerve lesions. Five patients (45.5%) died; 3 of these were adults with var. gattii and 2 were men with both var. neoformans and HIV-1 infections. This prospective tropical study documents the emergence of C. neoformans var. neoformans in patients with HIV-1 infection in a country where previously var. gattii had predominated in the immunocompetent. There has been no earlier report of cryptococcosis in an HIV-1 seropositive patient in PNG. Despite presumed exposure to both varieties of C. neoformans, var. gattii infections had been most frequent. As HIV-1 spreads, the proportion of hosts infected with var. neoformans may rise. The course of meningitis caused by the 2 varieties of C. neoformans may differ, with mortality in the tropics remaining particularly high. In PNG the environmental source of C. neoformans remains elusive.


Subject(s)
Cryptococcosis/complications , Meningitis/microbiology , Adolescent , Adult , Amphotericin B/adverse effects , Amphotericin B/therapeutic use , Antifungal Agents/adverse effects , Antifungal Agents/therapeutic use , Child , Cryptococcosis/drug therapy , Female , Flucytosine/adverse effects , Flucytosine/therapeutic use , Humans , Male , Meningitis/complications , Meningitis/drug therapy , Papua New Guinea , Treatment Outcome
16.
P N G Med J ; 38(3): 163-71, 1995 Sep.
Article in English | MEDLINE | ID: mdl-9522855

ABSTRACT

A clinico-sociodemographic and microbiological survey was carried out at the Port Moresby General Hospital Antenatal Clinic to determine the prevalences of bacterial vaginosis, Trichomonas vaginalis and Candida albicans vaginal infections in pregnancy and to examine if the infections had any association with some suspected sociodemographic risk factors. The study was carried out between December 1990 and January 1991. Of 206 consecutive subjects surveyed, 79 (38%) had symptomatic infection. However, on speculum examination, abnormal discharge was seen in 188 (91%). 118 (57%) had microbiologically confirmed infection. The prevalences of the individual infections were T. vaginalis 19%, C. albicans 23% and bacterial vaginosis 23%. Combined infection, i.e. two infections occurring together in the same subject, was uncommon. None of the infections had an association with any of the sociodemographic characteristics studied. Of the 118 positive subjects, 52 (44%) complained of vaginal discharge and 55 (47%) complained of pruritus.


PIP: The prevalences of vaginal infections with Trichomonas vaginalis, bacterial vaginosis, and Candida albicans were investigated in 206 consecutive pregnant women presenting to Port Moresby (Papua New Guinea) General Hospital in 1990-91 for their first antenatal visit. Bacteriologic investigation identified Candida in 48 women (23%), T. vaginalis in 39 (19%), and bacterial vaginosis in 48 (23%). Overall, 118 women (57%) were bacteriologically positive for at least one infection. 79 (38%) of the infected women complained of a vaginal discharge and 78 (38%) reported vulvar irritation; however, vaginoscopy revealed abnormal discharge in 188 (91%) of women with an infection. Infection was not associated with gestational age or any of the sociodemographic variables examined (age, parity, ethnic group, residence, husband's education). The fact that the majority of pregnant women in this series had a vaginal infection is alarming in light of the hypothesized association of such infections with intra-amniotic infection, endometritis, premature rupture of the membranes, preterm labor or birth, and low birth weight. A randomized, controlled prospective study is needed to assess the extent to which, if any, these infections are related to the high perinatal morbidity and mortality from low birth weight at Port Moresby General Hospital.


Subject(s)
Candidiasis, Vulvovaginal/epidemiology , Pregnancy Complications, Infectious/epidemiology , Pregnancy Complications, Parasitic/epidemiology , Trichomonas Vaginitis/epidemiology , Vaginosis, Bacterial/epidemiology , Adult , Animals , Candida albicans/isolation & purification , Colposcopy , Comorbidity , Demography , Female , Gestational Age , Hospitals, General , Humans , Papua New Guinea/epidemiology , Pregnancy , Prenatal Care , Prevalence , Pruritus Vulvae/epidemiology , Risk Factors , Socioeconomic Factors , Trichomonas vaginalis/isolation & purification , Vaginal Discharge/epidemiology
17.
Trans R Soc Trop Med Hyg ; 88(5): 565-8, 1994.
Article in English | MEDLINE | ID: mdl-7992341

ABSTRACT

Reversible cerebellar dysfunction has been described in association with typhoid fever by a number of authors. Ataxia and tremors are relatively common manifestations of typhoid fever in Papua New Guinea. A series of 14 patients with typhoid fever and ataxia was compared with non-ataxic typhoid patients. Hyponatraemia and hypoalbuminaemia were common in both groups and more severe in the ataxic group. Hypotension was also more common in the ataxic group. These features may reflect more severe disease. All isolates of Salmonella typhi, from both ataxic and non-ataxic patients, were phage type D2 which is endemic around Port Moresby. Tests for autoantibodies cross-reacting with cerebellar tissue were negative. It is possible that cerebellar dysfunction in typhoid fever is more common in association with phage type D2.


Subject(s)
Cerebellar Ataxia/etiology , Typhoid Fever/complications , Adolescent , Adult , Autoantibodies/analysis , Cerebellar Ataxia/blood , Cerebellar Ataxia/immunology , Female , Humans , Hypotension/complications , Male , Middle Aged , Purkinje Cells/immunology , Serum Albumin/metabolism , Sodium/blood , Typhoid Fever/blood , Typhoid Fever/immunology
18.
Postgrad Med J ; 69(812): 466-8, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8208644

ABSTRACT

Shigella infections are usually restricted to the intestine. There are few reports of Shigella isolated from the blood and most of these are from children, usually in neonates and the malnourished. In the small number of adult cases of Shigella bacteraemia which have been reported, there appears to be an association with underlying disease and immunosuppression including acquired immunodeficiency syndrome. We report three adult cases in which Shigella were isolated from blood. Two of these patients made an uneventful recovery whilst the third died. An underlying cause of immunosuppression was suspected in this patient but unproven.


Subject(s)
Bacteremia , Dysentery, Bacillary , Adult , Bacteremia/complications , Bacteremia/diagnosis , Dysentery, Bacillary/complications , Dysentery, Bacillary/diagnosis , Humans , Male , Shigella/isolation & purification
19.
Diagn Cytopathol ; 8(4): 392-3, 1992.
Article in English | MEDLINE | ID: mdl-1638940

ABSTRACT

A case of nodular lesion of the breast in a 37 year old female caused by filariasis is described. The case is instructive since the diagnosis was made by fine-needle aspiration cytology.


Subject(s)
Breast Diseases/parasitology , Elephantiasis, Filarial/pathology , Wuchereria bancrofti/isolation & purification , Adult , Animals , Biopsy, Needle , Breast Diseases/pathology , Female , Humans
20.
J Trop Pediatr ; 36(3): 101-3, 1990 06.
Article in English | MEDLINE | ID: mdl-2362308

ABSTRACT

Bacterial examination of stools of children with diarrhoea was carried out at Port Moresby, Papua New Guinea, where little information is available concerning the causative bacteria of diarrhoea. Shigellae, enterotoxigenic Escherichia coli, Bacillus cereus, Staphylococcus aureus, Campylobacter jejuni, and Aeromonas hydrophila were isolated with the decreasing frequency in that order. Among these, enterotoxigenic E. coli and C. jejuni were isolated for the first time in this country. Although Vibrio parahaemolyticus was recovered from sea water, no cases suffering from this organism were found.


Subject(s)
Bacterial Infections , Diarrhea, Infantile/etiology , Bacterial Infections/epidemiology , Child , Child, Preschool , Diarrhea, Infantile/epidemiology , Humans , Infant , Papua New Guinea/epidemiology
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