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1.
Vaccine ; 27(6): 803-14, 2009 Feb 05.
Article in English | MEDLINE | ID: mdl-19071179

ABSTRACT

An international meeting on Bordetella pertussis assay standardization and harmonization was held at the Centers for Disease Control and Prevention (CDC), Atlanta, GA, 19-20 July 2007. The goal of the meeting was to harmonize the immunoassays used for pertussis diagnostics and vaccine evaluation, as agreed upon by academic and government researchers, regulatory authorities, vaccine manufacturers, and the World Health Organization (WHO). The primary objectives were (1) to provide epidemiologic, laboratory, and statistical background for support of global harmonization; (2) to overview the current status of global epidemiology, pathogenesis and immunology of pertussis; (3) to develop a consensus opinion on existing gaps in understanding standardization of pertussis assays used for serodiagnosis and vaccine evaluation; and (4) to search for a multicenter process for addressing these priority gaps. Presentations and discussions by content experts addressed these objectives. A prioritized list of action items to improve standardization and harmonization of pertussis assays was identified during a group discussion at the end of the meeting. The major items included: (1) to identify a group that will organize, prepare, maintain, and distribute proficiency panels and key reagents such as reference and control sera; (2) to encourage the development and identification of one or more reference laboratories that can serve as an anchor and resource for other laboratories; (3) to define a performance-based assay method that can serve as a reference point for evaluating laboratory differences; (4) to develop guidance on quality of other reagents, e.g., pertussis toxin and other antigens, and methods to demonstrate their suitability; (5) to establish an international working group to harmonize the criteria to evaluate the results obtained on reference and proficiency panel sera; (6) to create an inventory to determine the amount of appropriate and well-characterized sera that are available globally to be used as bridging reagents for vaccine licensure; and (7) to seek specific guidance from regulatory authorities regarding the expectations and requirements for the licensure of new multicomponent pertussis vaccines.


Subject(s)
Bordetella pertussis/immunology , Clinical Laboratory Techniques/standards , Whooping Cough/diagnosis , Whooping Cough/prevention & control , Centers for Disease Control and Prevention, U.S. , Humans , United States , Whooping Cough/epidemiology , Whooping Cough/immunology
2.
Am J Transplant ; 8(4): 832-8, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18261175

ABSTRACT

Routine versus selective predonation liver biopsy (LBx) remains controversial for assuring the safety of right hepatic lobe live donor (RHLD). Between December 1999 and March 2007, 403 potential RHLD were evaluated; 142 donated. Indications for selective LBx were: abnormal liver function tests or imaging studies, body mass index (BMI) >28, history of substance abuse or family history of immune mediated liver disease. All donors had a LBx at the time of surgery. Of 403 potential RLD, 149(36.9%) were accepted as donors, 25(6.3%) had their recipient receive a deceased donor graft, 94(23.4%) were rejected, 52(12.9%) stopped the evaluation process, 76(18.8%) withdrew from the process and 7(1.7%) are currently completing evaluation. Eighty-seven (21.5%) met criteria and were biopsied. Seventy-three (83.9%) had either normal (n = 24) or macrosteatosis <10% (n = 49); 51 of these donated. Abnormal LBx eliminated 15 potential donors. No significant abnormalities were found in donation biopsies of donors not meeting algorithm criteria. Three of 87 (3.4%) had complications requiring overnight admission (2 for pain, 1 for bleeding; transfusion not required). Use of this algorithm resulted in 78% of potential donors avoiding biopsy and potential complications. No significant liver pathology was identified in donors not meeting criteria for evaluation LBx. Routine predonation LBx is unnecessary in potential RHLD.


Subject(s)
Liver Transplantation/pathology , Liver/cytology , Living Donors , Adult , Algorithms , Biopsy/adverse effects , Fatty Liver/epidemiology , Fatty Liver/pathology , Humans , Liver/anatomy & histology , Liver/pathology , Patient Selection , Postoperative Complications/pathology , Reproducibility of Results , Safety , Treatment Outcome
3.
Endoscopy ; 37(6): 594-6, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15933938

ABSTRACT

Capsule endoscopy is a new technology developed to investigate diseases of the small intestine. It has been shown to be superior to current modalities such as small-bowel radiography and enteroscopy. We describe a patient with long-standing celiac disease who presented with abdominal pain, diarrhea, and weight loss, after many years on a gluten-free diet. The symptom complex and results from small-bowel radiography and computerized tomography raised concern about progression to lymphoma, and ultimately a laparoscopy and small-bowel resection were done for diagnosis. A capsule endoscopy was performed to assess the extent of the patient's enteropathy-type intestinal T-cell lymphoma after three cycles of chemotherapy. We report the first use of capsule endoscopy in the setting of celiac disease associated enteropathy-type intestinal T-cell lymphoma. These endoscopic findings are correlated with those from gross and microscopic pathology and barium small-bowel radiography.


Subject(s)
Celiac Disease/diagnosis , Endoscopy, Digestive System/methods , Jejunal Neoplasms/diagnosis , Lymphoma, T-Cell/diagnosis , Miniaturization/instrumentation , Biopsy , Celiac Disease/complications , Diagnosis, Differential , Humans , Intestinal Mucosa/pathology , Jejunal Neoplasms/complications , Lymphoma, T-Cell/complications , Male , Middle Aged , Radiography, Abdominal , Tomography, X-Ray Computed
4.
Liver Transpl ; 7(7): 637-42, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11460232

ABSTRACT

Life-threatening hypophosphatemia (phosphorus < 1.0 mg/dL) has been reported only once after liver resection for tumor and was associated with a significant increase in postoperative complications. Hypophosphatemia is associated with reversible cardiac dysfunction, hypoventilation, and impaired immunity. The purpose of this study was to determine the incidence of hypophosphatemia after elective right hepatic lobectomy for live donor adult liver transplantation (LDALT), investigate the associated complication rate and surgical outcome of live liver donors, and determine the efficacy of prospective treatment with phosphate repletion as part of total parenteral nutrition (TPN). Evaluation of 30 donors who provided 30 right-lobe grafts between December 1998 and January 2000 was performed. Of the initial 18 live liver donors (group 1), 10 donors were treated with TPN that contained slightly more (35 +/- 8 mmol/d) than the recommended daily allowance (RDA) of phosphorus (30 mmol/d) starting on postoperative day 1. The last 12 donors (group 2) were prospectively studied and administered similar TPN with 2 times the RDA for phosphorus (60 mmol/d). All donors in group 1 developed hypophosphatemia that was either life threatening (phosphorus < 1.0 mg/dL) in 70% or severely depleted (phosphorus, 1.5 to 1.1 mg/dL) in 30%. With more aggressive phosphate repletion (group 2), only 8% developed life-threatening (phosphorus < 1.0 mg/dL) hypophosphatemia and 30% developed severe (phosphorus, 1.1 to 1.5 mg/dL) hypophosphatemia. Results suggest that hypophosphatemia is a universal event after LDALT and may have contributed to the observed complications in this study. Repletion of phosphorus at twice the RDA abrogates the incidence of hypophosphatemia and may reduce donor morbidity. Institutions performing LDALT should carefully monitor live liver donors for hypophosphatemia and correct abnormal phosphate levels. Additional studies are needed to determine whether more aggressive parenteral repletion can prevent postoperative hypophosphatemia and thus improve outcomes.


Subject(s)
Hepatectomy/adverse effects , Hypophosphatemia/etiology , Living Donors , Adult , Female , Humans , Hypophosphatemia/therapy , Male , Parenteral Nutrition, Total , Prospective Studies , Retrospective Studies
5.
Arch Surg ; 136(4): 425-33, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11296114

ABSTRACT

HYPOTHESIS: Live donor adult liver transplantation (LDALT) is a safe and efficacious treatment for patients with end-stage liver disease. DESIGN: Case-control study. SETTING: Hepatobiliary surgery and liver transplantation unit. PATIENTS: From December 10, 1998, through April 10, 2000, a single team performed 15 LDALT procedures with 2 simultaneous living donor kidney transplants. During this period, 66 potential donors were screened and evaluated. INTERVENTIONS: Potential donors were evaluated with 3-dimensional helical computed tomographic scan, including volume renderings for hepatic lobar volume, vascular anatomy, virtual resection planes, and morphologic features. Suitable donors undergo complete medical and psychiatric evaluation and preoperative arteriography. MAIN OUTCOME MEASURES: Donor demographics, evaluation data, operative data, hospital length of stay, and morbidity. RESULTS: A total of 38 men (58%) and 28 women (42%) were evaluated with 15 donors participating in LDALT. Two additional donors provided kidney grafts for simultaneous transplantation at the time of LDALT. Thirty-two donors (48%) were rejected for either donor or recipient reasons, and 10 patients (15%) elected not to participate after initial screening. Three-dimensional volume renderings by helical computed tomographic scan predicted right lobe liver volume within 92% of actual graft volume. Donor morbidity, including all complications, was 67% with no mortality. Residual liver regenerated to approximately 70% of initial volume within 1 week and 80% within 1 month after surgery. CONCLUSIONS: Donor evaluation is an important component of LDALT. Significant donor morbidity is encountered even with careful selection. To minimize donor morbidity, groups considering initiating living donor programs should have expertise in hepatic resection and vena cava preservation using the "piggyback" technique during liver transplantation.


Subject(s)
Liver Diseases/surgery , Liver Transplantation/methods , Living Donors , Adolescent , Adult , Case-Control Studies , Female , Humans , Liver/diagnostic imaging , Liver Regeneration , Male , Middle Aged , Tomography, X-Ray Computed
6.
Vaccine ; 19(23-24): 3248-52, 2001 Apr 30.
Article in English | MEDLINE | ID: mdl-11312021

ABSTRACT

Because of recent concern that whole-cell pertussis vaccination can drive antigenic divergence of circulating isolates of Bordetella pertussis, we compared 12 clinical isolates of B. pertussis collected in Japan, the first country to introduce acellular pertussis vaccines, with the vaccine strain. We used pulsed-field gel electrophoresis, sequencing of ptx and prn genes and expression of fimbriae. Most of the isolates collected before or after introduction of acellular vaccine possess similar restriction patterns. They contain ptx genes and prn alleles similar to the vaccine strain and to European isolates collected before the introduction of vaccination. Two recently collected isolates exhibiting a different pulsed-field gel electrophoresis pattern possess ptxS1 and prn alleles similar to the alleles harbored by European isolates circulating currently. Our preliminary results suggest that, if acellular pertussis vaccine-induced antigenic divergence exists, it is likely to be a slow or rare process.


Subject(s)
Bordetella pertussis/isolation & purification , Pertussis Vaccine/pharmacology , Antigenic Variation , Antigens, Bacterial/genetics , Antigens, Bacterial/isolation & purification , Bordetella pertussis/genetics , Bordetella pertussis/immunology , DNA, Bacterial/genetics , DNA, Bacterial/isolation & purification , Electrophoresis, Gel, Pulsed-Field , Europe , Genes, Bacterial , Humans , Japan , Pertussis Vaccine/immunology , Selection, Genetic , Vaccines, Acellular/immunology , Vaccines, Acellular/pharmacology
8.
Infect Immun ; 68(7): 4049-54, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10858221

ABSTRACT

We examined the structural components of pertussis toxin that are required for efficient export from Bordetella pertussis via the Ptl system, a member of the type IV family of macromolecular transporters. First, we constructed a strain of B. pertussis that contains a functional Ptl system but does not produce pertussis toxin. Plasmids which express either the S1 subunit or the B oligomer were then introduced into this strain. We found that the B oligomer of the toxin is not secreted in the absence of the S1 subunit. Conversely, the S1 subunit is also not secreted by a Ptl-mediated mechanism in the absence of the B oligomer. Thus, an assembled holotoxin is required for Ptl-mediated export of pertussis toxin from B. pertussis.


Subject(s)
Bordetella pertussis/metabolism , Pertussis Toxin , Virulence Factors, Bordetella/metabolism , Base Sequence , Biological Transport, Active , Bordetella pertussis/genetics , Bordetella pertussis/pathogenicity , DNA Primers/genetics , Genes, Bacterial , Plasmids/genetics , Protein Structure, Quaternary , Sequence Deletion , Virulence , Virulence Factors, Bordetella/chemistry , Virulence Factors, Bordetella/genetics
9.
Infect Immun ; 68(6): 3763-7, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10816544

ABSTRACT

Recently, concern has been voiced about the potential effect that antigenic divergence of circulating strains of Bordetella pertussis might have on the efficacy of pertussis vaccines. In order to model antigenic drift of pertussis toxin, a critical component of many pertussis vaccines, and to examine the effects of such drift on antibody neutralization, we engineered a strain of B. pertussis to produce a variant pertussis toxin molecule that contains many of the amino acid changes found in the toxin encoded by Bordetella bronchiseptica ptx genes. This altered form of the toxin, which is efficiently secreted by B. pertussis and which displays significant biological activity, was found to be neutralized by antibodies induced by vaccination as readily as toxin produced by wild-type B. pertussis. These findings suggest that significant amino acid changes in the pertussis toxin sequence can occur without drastically altering the ability of antibodies to recognize and neutralize the toxin molecule.


Subject(s)
Antibodies, Bacterial/immunology , Antigens, Bacterial/immunology , Bordetella/immunology , Pertussis Toxin , Pertussis Vaccine/immunology , Virulence Factors, Bordetella/immunology , Amino Acid Sequence , Antigens, Bacterial/genetics , Bordetella/genetics , Bordetella bronchiseptica/genetics , Bordetella bronchiseptica/immunology , Bordetella pertussis/genetics , Bordetella pertussis/immunology , Genes, Bacterial , Genetic Variation , Humans , Molecular Sequence Data , Neutralization Tests , Pertussis Vaccine/genetics , Pertussis Vaccine/therapeutic use , Virulence Factors, Bordetella/genetics , Whooping Cough/prevention & control
10.
Kidney Int Suppl ; 69: S119-24, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10084295

ABSTRACT

Parenteral iron dextran is efficacious and safe for iron repletion in patients with iron-deficiency anemia. The risk for developing reactions to parenteral iron infusion can be attenuated if patients are carefully selected. Patients with underlying autoimmune disease, malnutrition with indolent infection, and risk for iron overload syndromes should be carefully monitored for complications. Further, the rate of infusion and the route of administration of iron dextran play roles in the risk of adverse reactions. The purpose of this review is to identify and elucidate the mechanisms of the acute and chronic toxicities associated with parenteral iron dextran use.


Subject(s)
Anemia, Iron-Deficiency/drug therapy , Iron-Dextran Complex/administration & dosage , Iron-Dextran Complex/adverse effects , Anemia, Iron-Deficiency/etiology , Anemia, Iron-Deficiency/metabolism , Autoimmune Diseases/etiology , Humans , Infections/etiology , Infusions, Parenteral , Iron/metabolism , Iron Deficiencies , Iron Overload/etiology , Muscular Diseases/etiology
11.
Curr Opin Microbiol ; 2(1): 25-9, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10047550

ABSTRACT

In the past year, our knowledge of type IV transporters of Gram-negative bacteria has further expanded. Advances include the discovery of additional members of this family of proteins, increased knowledge of the morphologies of type IV transporters, and a better understanding of the mechanisms by which macromolecules are exported by these systems.


Subject(s)
Bacterial Proteins/chemistry , Caenorhabditis elegans Proteins , Carrier Proteins/chemistry , Virulence Factors , Agrobacterium tumefaciens/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bordetella pertussis/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Conjugation, Genetic/physiology , DNA, Bacterial/metabolism , DNA-Binding Proteins/genetics , Helicobacter pylori/metabolism , Legionella pneumophila/metabolism , Microtubule-Associated Proteins/metabolism
12.
Infect Immun ; 67(2): 754-9, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9916087

ABSTRACT

PtlC is a member of a set of proteins necessary for the secretion of pertussis toxin (PT) from Bordetella pertussis. Using polyclonal antibodies specific for PtlC, we identified PtlC as a protein with an apparent molecular weight of 85,000 that localizes to the membrane fraction of bacterial cell extracts. We found that a mutant strain of B. pertussis that contains an in-frame deletion in ptlC is unable to secrete PT and that PT secretion is fully restored by expressing ptlC in trans, indicating that PtlC is essential for transport of PT across the bacterial membrane(s). PT secretion was inhibited in wild-type B. pertussis after introduction of a plasmid expressing a mutant ptlC altered in the putative nucleotide-binding region, suggesting that this region of PtlC is essential for proper function. Moreover, the observed dominant negative phenotype suggests that PtlC either functions as a multimer or interacts with some other component(s) necessary for secretion of PT.


Subject(s)
Bacterial Proteins/metabolism , Bacterial Toxins , Bordetella pertussis/metabolism , Pertussis Toxin , Virulence Factors, Bordetella/metabolism , Animals , Bacterial Proteins/genetics , Binding Sites , Bordetella pertussis/genetics , Female , Mice , Mice, Inbred BALB C , Mutagenesis
14.
J Bacteriol ; 179(23): 7577-80, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9393726

ABSTRACT

PtlH is a member of a specialized set of transport proteins that is essential for secretion of pertussis toxin (PT) from Bordetella pertussis. Previously, PtlH was shown to contain a consensus nucleotide-binding motif. Here, we demonstrate that introduction of plasmids containing mutant forms of ptlH, altered in the putative nucleotide-binding region, into a wild-type strain of B. pertussis resulted in inhibition of PT secretion. Thus, this region of PtlH appears to be essential for protein function. Moreover, the observed dominant negative phenotype suggests that PtlH either functions as a multimer or interacts with another component necessary for secretion of PT.


Subject(s)
Bacterial Proteins , Bordetella pertussis/metabolism , Carrier Proteins/metabolism , Membrane Transport Proteins , Pertussis Toxin , Virulence Factors, Bordetella/metabolism , Binding Sites , Biological Transport , Bordetella pertussis/genetics , Carrier Proteins/genetics , Cloning, Molecular , Consensus Sequence , Mutagenesis, Site-Directed , Nucleotides/metabolism
15.
Infect Immun ; 65(12): 4904-8, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9393774

ABSTRACT

Using a mouse model of Bordetella pertussis infection, we have analyzed the role of gamma interferon (IFN-gamma) in bacterial clearance from the respiratory tract. Adult BALB/c mice began to clear a respiratory infection within 3 weeks postinfection, with complete resolution of infection 6 to 8 weeks postinfection. In contrast, neither adult SCID mice (which lack mature B and T lymphocytes) nor adult nude mice (which lack mature T lymphocytes) controlled B. pertussis infection, and both strains died within 3 to 5 weeks postinfection. Short-term T-cell lines generated from the draining lymph nodes of the lungs of infected BALB/c mice were found to be CD4+ and produced IFN-gamma but no detectable interleukin-4. Analyses of IFN-gamma mRNA induction in the lungs of mice following B. pertussis infection showed that in both BALB/c and C57BL/6 mice, IFN-gamma mRNA levels increased sharply by 1 week postinfection and then subsequently declined. Further exploration of a potential role for IFN-gamma demonstrated that infection of adult BALB/c mice depleted of IFN-gamma in vivo with anti-IFN-gamma monoclonal antibodies resulted in greater numbers of bacteria recovered from the lungs than in infected, control BALB/c mice, although IFN-gamma-depleted mice could subsequently clear the infection. Infection of mice which have a disrupted IFN-gamma gene resulted in bacterial clearance with a time course similar to those seen with IFN-gamma-depleted mice. These results indicate that IFN-gamma plays a role in controlling B. pertussis infection.


Subject(s)
Bordetella pertussis/immunology , Interferon-gamma/immunology , Whooping Cough/immunology , Animals , B-Lymphocytes/immunology , Immunity, Cellular , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, SCID , T-Lymphocytes/immunology
16.
J Clin Microbiol ; 35(6): 1550-5, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9163480

ABSTRACT

During a surveillance program associated with the Italian clinical trial for the evaluation of new acellular pertussis vaccines, two bacterial isolates were obtained in cultures of samples from immunocompetent infants who had episodes of cough. Both clinical isolates were identified as Bordetella bronchiseptica by biochemical criteria, although both strains agglutinated with antisera specific for Bordetella parapertussis, suggesting that the strains exhibited some characteristics of both B. bronchiseptica and B. parapertussis. Both children from whom these strains were isolated exhibited an increase in serum antibody titer to pertussis toxin (PT), a protein that is produced by Bordetella pertussis but that is not thought to be produced by B. bronchiseptica. We therefore examined whether the clinical isolates were capable of producing PT. Neither strain produced PT under laboratory conditions, although both strains appeared to contain a portion of the ptx region that encodes the structural subunits of PT. In order to determine whether the ptx genes may encode functional proteins, we inserted an active promoter directly upstream of the ptx region of one of these strains. Biologically active PT was produced, suggesting that this strain contains the genetic information necessary to encode an active PT molecule. Sequence analysis of the ptx promoter region of both strains indicated that, while they shared homology with the B. bronchiseptica ATCC 4617 sequence, they contained certain sequence motifs that are characteristic of B. parapertussis and certain motifs that are characteristic of B. pertussis. Taken together, these findings suggest that variant strains of B. bronchiseptica exist and might be capable of causing significant illness in humans.


Subject(s)
Bordetella Infections/microbiology , Bordetella bronchiseptica/genetics , Bordetella bronchiseptica/isolation & purification , Cough/microbiology , Pertussis Toxin , Virulence Factors, Bordetella/analysis , Acute Disease , Adenylyl Cyclases/analysis , Adhesins, Bacterial/analysis , Base Sequence , Bordetella bronchiseptica/chemistry , Bordetella bronchiseptica/drug effects , Clinical Trials as Topic , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Flagellin/analysis , Gene Expression Regulation, Bacterial/genetics , Genes, Bacterial/genetics , Genetic Variation/genetics , Hemagglutinins/analysis , Humans , Immune Sera , Infant , Molecular Sequence Data , Pertussis Vaccine , Promoter Regions, Genetic/genetics , Sequence Analysis, DNA , Virulence Factors, Bordetella/genetics
17.
Pediatr Nurs ; 23(1): 73-5; discussion 76-8, 86, 1997.
Article in English | MEDLINE | ID: mdl-9137025

ABSTRACT

Perinatal substance abuse causes a host of problems including physical and psychological impairments to a developing fetus. However, responding to the needs of pregnant women who use drugs and their children poses an additional challenge in this already deplorable situation. Foster care, adoption, criminalization, and reunification are all possibilities as intervention options in this dilemma. Each of these options prompts additional problems for mother, child, and provider. What was once uncommon or uncontroversial for public health nursing is now bringing a new wave of discussions in the health system and nurses need to be cognizant of the ramifications of delivering care to perinatal substance abusing mothers and their families. Assessment, planning, intervention, and evaluation--the nursing process--emerges as an invaluable tool.


Subject(s)
Ethics, Nursing , Neonatal Screening/legislation & jurisprudence , Pregnant Women , Substance Abuse Detection/legislation & jurisprudence , Substance-Related Disorders/prevention & control , Decision Making , Female , Humans , Infant, Newborn , Neonatal Nursing/legislation & jurisprudence , Pregnancy , Resource Allocation , United States
18.
J Biol Chem ; 271(49): 31643-9, 1996 Dec 06.
Article in English | MEDLINE | ID: mdl-8940184

ABSTRACT

The pertussis toxin secretion system of Bordetella pertussis initially was thought to comprise eight proteins, PtlA-PtlH. We have investigated the existence of another protein, PtlI, encoded by a putative gene located between ptlD and ptlE. A B. pertussis strain expressing a ptlI::phoA translational fusion possessed alkaline phosphatase activity, suggesting that ptlI encodes a protein. In B. pertussis, a protein with an apparent molecular weight of approximately 5,200 (similar to that predicted by the ptlI sequence) was immunoreactive with an antibody raised to a PtlI-maltose-binding protein fusion protein. PtlE expression in a mutant sustaining an in-frame deletion in ptlI indicated that ptlE starts further downstream than initially predicted. PtlF, not detected in the ptlI deletion mutant, was restored partially by expressing ptlI in trans. A 36-kDa species, consistent with a PtlI-PtlF complex, was immunoreactive with antibodies to PtlI and PtlF in nonreduced cell extracts of a Bordetella bronchiseptica strain which overexpresses the Ptl proteins. Upon dithiothreitol treatment, the 36-kDa species was diminished greatly or undetectable. In B. pertussis, PtlI and PtlF co-precipitated with antibody to PtlF. These findings demonstrate the existence of PtlI and a PtlI-PtlF complex, providing the first description of an interaction between Ptl proteins.


Subject(s)
Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bordetella pertussis/genetics , Membrane Proteins/metabolism , Pertussis Toxin , Virulence Factors, Bordetella/metabolism , Base Sequence , Bordetella pertussis/metabolism , Dithiothreitol/pharmacology , Electrophoresis, Polyacrylamide Gel , Immunosorbent Techniques , Molecular Sequence Data , Molecular Weight
19.
Infect Immun ; 64(10): 4020-6, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8926063

ABSTRACT

Bordetella pertussis is the only bacteria] species which is known to produce pertussis toxin (PT); however, both Bordetella bronchiseptica and Bordetella parapertussis contain regions homologous to the ptx genes of B. pertussis that encode the toxin subunits. After finding that several children with B. parapertussis infections exhibited modest antibody titers to PT, we examined the ptx genes of both B. parapertussis and B. bronchiseptica to determine whether they would encode stable, functional proteins even though their promoters are thought to be inactive under the conditions that have been examined. We inserted a functional promoter directly upstream of the ptx-ptl region of both species and examined culture supernatants of the resulting strains for PT activity. Biologically active PT was found in the culture supernatants of both engineered species. The toxin encoded by the B. parapertussis ptx genes appeared more labile in culture supernatants than did toxin produced by either B. pertussis or the engineered strain of B. bronchiseptica. This lability might be due to the lack of a full-length S2 subunit. We also investigated the ptl genes of these species, which are necessary for the secretion of this toxin, and found that both B. bronchiseptica and B. parapertussis contain at least certain of these genes, including ptlE and ptlF. Moreover, B. bronchiseptica appeared to contain all essential ptl genes since the introduction of a functional promoter directly upstream of the ptx-ptl region resulted in both production and efficient secretion of toxin. These results indicate that despite a number of amino acid changes in the sequences of the toxins, the toxins encoded by B. bronchiseptica and B. parapertussis are active.


Subject(s)
Bordetella bronchiseptica/genetics , Bordetella/genetics , Genes, Bacterial , Pertussis Toxin , Virulence Factors, Bordetella/genetics , Animals , Base Sequence , CHO Cells , Cricetinae , Molecular Sequence Data , Virulence Factors, Bordetella/chemistry , Virulence Factors, Bordetella/immunology
20.
Nutrition ; 12(6): 411-5, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8875535

ABSTRACT

Iron deficiency anemia is common among hospitalized patients, and blood losses from diagnostic phlebotomy increase the likelihood of a negative iron balance. The role for iron supplementation of total parenteral nutrition (TPN) in these patients is unclear. Twenty-three patients with iron deficiency anemia were identified. Twelve patients were randomized to receive TPN without iron (group 1) and 11 received TPN supplemented with 10 mg of iron as iron dextran daily (group 2). Both groups were matched for age, serum iron studies, red cell indices, and hemogram. After a 7-d period, the mean serum iron in group 2 increased from 10 to 26 micrograms/dL, with an increased transferrin saturation from 7.3 to 15.3% (each, p < 0.05). No changes in total iron binding capacity, ferritin, reticulocyte count, hemoglobin, hematocrit, or mean corpuscular volume were observed in the two groups. The incidence of infectious complications was not different between both groups. We conclude that iron supplementation of TPN appears safe and is effective in increasing serum iron levels. The use of iron-supplemented short-term TPN needs to be further studied given no change in red cell indices, hemoglobin, hematocrit, or transfusion requirement.


Subject(s)
Anemia, Iron-Deficiency/therapy , Iron/administration & dosage , Parenteral Nutrition, Total , Adult , Aged , Aged, 80 and over , Anemia, Iron-Deficiency/complications , Erythrocyte Indices , Female , Ferritins/blood , Hematocrit , Hemoglobins/analysis , Humans , Infections/complications , Iron/blood , Male , Middle Aged , Protein Binding , Reticulocyte Count , Transferrin/metabolism
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