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1.
Am J Hum Genet ; 108(9): 1578-1589, 2021 09 02.
Article in English | MEDLINE | ID: mdl-34265237

ABSTRACT

Thoracic aortic aneurysm (TAA) is characterized by dilation of the aortic root or ascending/descending aorta. TAA is a heritable disease that can be potentially life threatening. While 10%-20% of TAA cases are caused by rare, pathogenic variants in single genes, the origin of the majority of TAA cases remains unknown. A previous study implicated common variants in FBN1 with TAA disease risk. Here, we report a genome-wide scan of 1,351 TAA-affected individuals and 18,295 control individuals from the Cardiovascular Health Improvement Project and Michigan Genomics Initiative at the University of Michigan. We identified a genome-wide significant association with TAA for variants within the third intron of TCF7L2 following replication with meta-analysis of four additional independent cohorts. Common variants in this locus are the strongest known genetic risk factor for type 2 diabetes. Although evidence indicates the presence of different causal variants for TAA and type 2 diabetes at this locus, we observed an opposite direction of effect. The genetic association for TAA colocalizes with an aortic eQTL of TCF7L2, suggesting a functional relationship. These analyses predict an association of higher expression of TCF7L2 with TAA disease risk. In vitro, we show that upregulation of TCF7L2 is associated with BCL2 repression promoting vascular smooth muscle cell apoptosis, a key driver of TAA disease.


Subject(s)
Aortic Aneurysm, Thoracic/genetics , Diabetes Mellitus, Type 2/genetics , Endothelial Cells/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Quantitative Trait Loci , Transcription Factor 7-Like 2 Protein/genetics , Aorta/metabolism , Aorta/pathology , Aortic Aneurysm, Thoracic/metabolism , Aortic Aneurysm, Thoracic/pathology , Case-Control Studies , Caspase 3/genetics , Caspase 3/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/pathology , Endothelial Cells/pathology , Gene Expression Regulation , Genome, Human , Genome-Wide Association Study , Humans , Introns , Michigan , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/pathology , Mutation , Proto-Oncogene Proteins c-bcl-2/metabolism , Transcription Factor 7-Like 2 Protein/metabolism , bcl-2-Associated X Protein/genetics , bcl-2-Associated X Protein/metabolism
2.
Emerg Radiol ; 30(3): 391-393, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37086336

ABSTRACT

Herein we share our preliminary experience with an ultrafast brain MRI technique for use in the ED consisting of axial T1-weighted (40 s), axial T2-weighted (62 s), axial diffusion-weighted (80 s), axial FLAIR (96 s), axial T2* (6 s), and axial susceptibility-weighted (108 s) imaging for a total scan time of 6 min and 53 s. Utilization of this ultrafast technique yields an efficient assessment of the brain, decreases ED length of stay and inpatient observation admissions, and may obviate the need for vascular imaging with either CTA or MRA in the ED.


Subject(s)
Brain , Magnetic Resonance Imaging , Humans , Magnetic Resonance Imaging/methods , Brain/diagnostic imaging , Emergency Service, Hospital
3.
High Educ Policy ; 35(3): 629-650, 2022.
Article in English | MEDLINE | ID: mdl-35765672

ABSTRACT

The study aims to examine how higher education institutions (HEIs) in three countries responded to the challenges of COVID-19 over a six-month period at the outbreak of the global pandemic. Employing document analysis, we examined 732 publicly available communications from 27 HEIs in Canada, China, and the USA. Through theoretical frameworks of crisis management and Situational Crisis Communication Theory (SCCT), we explore how HEIs respond to the pandemic and protect campus stakeholders. The study revealed common patterns in communication strategies during different stages of the pandemic that include accepting responsibility, emotional reassurance, and compensating victims. It also revealed key differences across social contexts and environments and distinct leadership styles. Findings offer insight into how HEIs communicated at the outset of the COVID-19 pandemic and inform the application of SCCT and crisis management theory to institutional behavior in the context of prolonged and intersecting disasters.

4.
BMC Med Inform Decis Mak ; 21(1): 195, 2021 06 21.
Article in English | MEDLINE | ID: mdl-34154570

ABSTRACT

BACKGROUND: Prescribing error represent a significant source of preventable harm to patients. Prescribing errors at discharge, including omission of pre-admission medications (PAM), are particularly harmful as they frequently propagate following discharge. This study assesses the impact of an educational intervention and introduction of an electronic patient record (EPR) in the same centre on omission of PAM at discharge using a pragmatic design. A survey of newly qualified doctors is used to contextualise findings. METHODS: Discharge prescriptions and discharge summaries were reviewed at discharge, and compared to admission medicine lists, using a paper-based chart system. Discrepancies were noted, using Health Information and Quality Authority guidelines for discharge prescribing. An educational intervention was conducted. Further review of discharge prescriptions and discharge summaries took place. Following introduction of an EPR, review of discharge summaries and discharge prescriptions was repeated. A survey was administered to recently qualified doctors (interns), and analysed using descriptive statistics and thematic analysis. RESULTS: Omission of PAM as prescribed or discontinued items at discharge occurs frequently. An educational intervention did not significantly change prescribing error rates (U = 1255.5, p = 0.206). EPR introduction did significantly reduce omission of PAM on discharge prescribing (U = 694, p < 0.001), however there was also a reduction in the rate of deliberate discontinuation of PAM at discharge (U = 1237.5, p = 0.007). Survey results demonstrated that multiple sources are required to develop a discharge prescription. Time pressure, access to documentation and lack of admission medicine reconciliation are frequently cited causes of discharge prescribing error. CONCLUSION: This study verified passive educational interventions alone do not improve discharge prescribing. Introduction of EPR improved discharge prescribing, but negatively impacted deliberate discontinuation of PAM at discharge. This is attributable to reduced access to key sources of information used in formulating discharge prescriptions, and separation of the discontinuation function from the prescribing function on the EPR discharge application.


Subject(s)
Electronic Health Records , Electronic Prescribing , Documentation , Drug Prescriptions , Humans , Medication Errors/prevention & control , Patient Discharge , Tertiary Care Centers
5.
Molecules ; 26(23)2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34885939

ABSTRACT

Hypervalent iodine heterocycles represent one of the important classes of hypervalent iodine reagents with many applications in organic synthesis. This paper reports a simple and convenient synthesis of benziodazolones by the reaction of readily available iodobenzamides with m-chloroperoxybenzoic acid in acetonitrile at room temperature. The structure of one of these new iodine heterocycles was confirmed by X-ray analysis. In combination with PPh3 and pyridine, these benziodazolones can smoothly react with alcohols or amines to produce the corresponding esters or amides of 3-chlorobenzoic acid, respectively. It was found that the novel benziodazolone reagent reacts more efficiently than the analogous benziodoxolone reagent in this esterification.

6.
Environ Monit Assess ; 193(7): 440, 2021 Jun 24.
Article in English | MEDLINE | ID: mdl-34164717

ABSTRACT

A multi-analytical geochemical investigation of Pb-contaminated collocated road dust and soils, at two size fractions, was performed in Fishtown, Philadelphia, PA, USA. The combinations of methods employed in this case study were chosen to better characterize the contamination, enhance identification of pollution sources, improve understanding of the impact of former Pb smelters, and to study the relationships between two media and between two size fractions. High concentrations of Cu and Sn were observed in both bulk and finer road dust, whereas large concentrations of Zn and Pb were found in both bulk and finer soil samples, implying pollution. There were no obvious associations between Pb soil concentrations and former smelter locations. Therefore, the primary source of the high mean Pb content in bulk (595 ppm) and fine soils (687 ppm) was likely legacy lead paint and/or leaded-gasoline products. Using electron microscopy, we found that Pb particles were mainly 0.1-10 µm in diameter and were ubiquitous in both soil and dust samples. Two-way analysis of variance tests revealed that, for most chemical elements explored here, there were statistically significant differences in concentrations based on media and size fractions, with finer sizes being more polluted than the bulk. The mineralogical composition and the sources of several pollutant elements (Cr, Cu, Zn, Pb), however, were similar for both soil and dust, pointing to material exchange between the two media. We suggest that future investigations of collocated road dust and soils in urban environments use the methodologies applied in this study to obtain detailed insights into sources of roadside pollution and the relationships between neighboring media.


Subject(s)
Metals, Heavy , Soil Pollutants , Dust/analysis , Environmental Monitoring , Lead , Metals, Heavy/analysis , Philadelphia , Soil , Soil Pollutants/analysis
7.
Eur J Clin Microbiol Infect Dis ; 39(4): 735-739, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31838607

ABSTRACT

Infectious endocarditis is a highly morbid infection that requires coordination of care across medical and surgical specialties, often through the use of a multidisciplinary team model. Multiple studies have demonstrated that such conferences can improve clinical outcomes. However, little is known about physicians' impressions of these groups. We surveyed 126 (response rate of 30%) internal medicine, infectious diseases, cardiology, and cardiac surgery providers 1 year after the implementation of an endocarditis team at the University of Michigan. Ninety-eight percent of physicians felt that the endocarditis team improved communication between specialties. Additionally, over 85% of respondents agreed that the group influenced diagnostic evaluation, reduced management errors, increased access to surgery, and decreased in-hospital mortality for endocarditis patients. These results suggest that multidisciplinary endocarditis teams are valued by physicians as a tool to improve patient care and serve an important role in increasing communication between providers.


Subject(s)
Attitude of Health Personnel , Endocarditis , Patient Care Team , Physicians/psychology , Humans , Interdisciplinary Communication , Surveys and Questionnaires
8.
Molecules ; 24(5)2019 Mar 11.
Article in English | MEDLINE | ID: mdl-30862025

ABSTRACT

A new practical procedure of imination for sulfide has been developed. The treatment of (N-tosylimino)-phenyl-λ³-iodane, PhINTs, with various sulfides in the presence of a catalytic amount of I2 under metal-free conditions affords the corresponding N-tosylsulfilimine compounds with moderate to good yields. This facile transfer procedure of the sulfonylimino group can also be applied to triphenylphosphine to produce the respective iminotriphenylphosphoranes in high yields. According to the reaction mechanism studies, the process of imination from (N-tosylimino)-phenyl-λ³-iodane to sulfide under the conditions may involve radical steps within the reaction mechanism.


Subject(s)
Imines/chemistry , Iodine/chemistry , Catalysis , Metals/chemistry , Sulfides/chemistry
9.
Beilstein J Org Chem ; 14: 1016-1020, 2018.
Article in English | MEDLINE | ID: mdl-29977373

ABSTRACT

A new bicyclic organohypervalent iodine heterocycle derivative of benziodazole was prepared by oxidation of 2-iodo-N,N'-diisopropylisophthalamide with m-chloroperoxybenzoic acid under mild conditions. Single crystal X-ray crystallography of this compound revealed a five-membered bis-heterocyclic structure with two covalent bonds between the iodine atom and the nitrogen atoms. This novel benziodazole is a very stable compound with good solubility in common organic solvents. This compound can be used as an efficient reagent for oxidatively assisted coupling of carboxylic acids with alcohols or amines to afford the corresponding esters or amides in moderate yields.

10.
Chemistry ; 23(3): 691-695, 2017 01 12.
Article in English | MEDLINE | ID: mdl-27794175

ABSTRACT

New pseudocyclic benziodoxole tosylates were prepared by the treatment of 1-hydroxybenziodoxolones with p-toluenesulfonic acid or via ligand transfer reaction between PhI(OH)OTs (Koser's reagent) and substituted 2-iodobenzoic acids under mild condition. Single crystal X-ray crystallography of these compounds revealed a pseudocyclic structure with a short intramolecular interaction of 2.362 Šbetween oxygen and iodine in the iodoxole ring. Pseudocyclic benziodoxole tosylates readily react with various organic substrates as electrophiles or oxidants to afford the corresponding iodonium salts or the products of oxidation. Furthermore, these compounds can be used as efficient recyclable hypervalent iodine reagents. The reduced form of a pseudocyclic benziodoxole tosylate, 2-iodobenzoic acid, can be efficiently recovered from the reaction mixture by a simple acid-base liquid-liquid biphasic procedure.

12.
Optom Vis Sci ; 94(3): 436-442, 2017 03.
Article in English | MEDLINE | ID: mdl-27870777

ABSTRACT

PURPOSE: To present a case of minocycline-induced blue scleral pigmentation and discuss the pathophysiology and differential diagnoses. The uses, mechanisms, and other adverse effects of minocycline will also be highlighted. CASE REPORT: An elderly Caucasian male patient presented for routine ocular examination complaining of blue discoloration to the whites of his eyes. He was found to have bilateral blue scleral pigmentation and blue discoloration to various other dermal areas of his body. The blue pigmentation was also visible in the posterior segment within a scleral crescent around his right optic nerve. This pigmentation was determined to be caused by long-term use of oral minocycline. CONCLUSIONS: Long-term minocycline use may induce scleral, dermal, and organ hyperpigmentation, typically blue or black in coloration. The pigmentation may reverse with discontinuation of the medication, but can also be permanent. The exact mechanism of pigment deposition remains uncertain, but several theories have been proposed. While the cosmetic appearance may be dramatic, this side effect is not known to cause any systemic or ocular morbidity.


Subject(s)
Anti-Bacterial Agents/adverse effects , Hyperpigmentation/chemically induced , Minocycline/adverse effects , Scleral Diseases/chemically induced , Skin Pigmentation/drug effects , Aged, 80 and over , Diagnosis, Differential , Humans , Hyperpigmentation/diagnosis , Male , Sclera/drug effects , Scleral Diseases/diagnosis
13.
Biochemistry ; 54(2): 490-6, 2015 Jan 20.
Article in English | MEDLINE | ID: mdl-25486106

ABSTRACT

The sodium-pumping NADH:ubiquinone oxidoreductase (Na(+)-NQR) is a bacterial respiratory enzyme that obtains energy from the redox reaction between NADH and ubiquinone and uses this energy to create an electrochemical Na(+) gradient across the cell membrane. A number of acidic residues in transmembrane helices have been shown to be important for Na(+) translocation. One of these, Asp-397 in the NqrB subunit, is a key residue for Na(+) uptake and binding. In this study, we show that when this residue is replaced with asparagine, the enzyme acquires a new sensitivity to K(+); in the mutant, K(+) both activates the redox reaction and uncouples it from the ion translocation reaction. In the wild-type enzyme, Na(+) (or Li(+)) accelerates turnover while K(+) alone does not activate. In the NqrB-D397N mutant, K(+) accelerates the same internal electron transfer step (2Fe-2S → FMNC) that is accelerated by Na(+). This is the same step that is inhibited in mutants in which Na(+) uptake is blocked. NqrB-D397N is able to translocate Na(+) and Li(+), but when K(+) is introduced, no ion translocation is observed, regardless of whether Na(+) or Li(+) is present. Thus, this mutant, when it turns over in the presence of K(+), is the first, and currently the only, example of an uncoupled Na(+)-NQR. The fact the redox reaction and ion pumping become decoupled from each other only in the presence of K(+) provides a switch that promises to be a useful experimental tool.


Subject(s)
Electron Transport Complex I/genetics , Electron Transport Complex I/metabolism , Potassium/metabolism , Sodium/metabolism , Vibrio cholerae/enzymology , Vibrio cholerae/genetics , Cations, Monovalent/metabolism , Electron Transport , Electrons , Ion Transport , Mutation , Quinone Reductases/metabolism , Vibrio cholerae/metabolism
14.
Adv Exp Med Biol ; 846: 201-20, 2015.
Article in English | MEDLINE | ID: mdl-25472540

ABSTRACT

Elevated exposure to prolactin (PRL) is epidemiologically associated with an increased risk of aggressive ER+ breast cancer. To understand the underlying mechanisms and crosstalk with other oncogenic factors, we developed the NRL-PRL mouse. In this model, mammary expression of a rat prolactin transgene raises local exposure to PRL without altering estrous cycling. Nulliparous females develop metastatic, histotypically diverse mammary carcinomas independent from ovarian steroids, and most are ER+. These characteristics resemble the human clinical disease, facilitating study of tumorigenesis, and identification of novel preventive and therapeutic approaches.


Subject(s)
Breast Neoplasms/pathology , Mammary Neoplasms, Experimental/pathology , Prolactin/physiology , Animals , Breast Neoplasms/genetics , Estradiol/metabolism , Estrogen Receptor alpha/metabolism , Female , Humans , Mammary Neoplasms, Experimental/genetics , Mice , Mice, Transgenic , Prolactin/blood , Prolactin/genetics , Rats , Receptor Cross-Talk/physiology
15.
J Biol Chem ; 288(43): 31241-9, 2013 Oct 25.
Article in English | MEDLINE | ID: mdl-24030824

ABSTRACT

The Na(+)-pumping NADH:quinone complex is found in Vibrio cholerae and other marine and pathogenic bacteria. NADH:ubiquinone oxidoreductase oxidizes NADH and reduces ubiquinone, using the free energy released by this reaction to pump sodium ions across the cell membrane. In a previous report, a conserved aspartic acid residue in the NqrB subunit at position 397, located in the cytosolic face of this protein, was proposed to be involved in the capture of sodium. Here, we studied the role of this residue through the characterization of mutant enzymes in which this aspartic acid was substituted by other residues that change charge and size, such as arginine, serine, lysine, glutamic acid, and cysteine. Our results indicate that NqrB-Asp-397 forms part of one of the at least two sodium-binding sites and that both size and charge at this position are critical for the function of the enzyme. Moreover, we demonstrate that this residue is involved in cation selectivity, has a critical role in the communication between sodium-binding sites, by promoting cooperativity, and controls the electron transfer step involved in sodium uptake (2Fe-2S → FMNC).


Subject(s)
Bacterial Proteins/metabolism , Quinone Reductases/metabolism , Sodium/metabolism , Vibrio cholerae/enzymology , Amino Acid Substitution , Aspartic Acid/chemistry , Aspartic Acid/genetics , Aspartic Acid/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Binding Sites , Electron Transport/physiology , Ion Transport/physiology , Mutation, Missense , Quinone Reductases/chemistry , Quinone Reductases/genetics , Sodium/chemistry , Vibrio cholerae/genetics
16.
Environ Sci Technol ; 48(24): 14300-8, 2014 Dec 16.
Article in English | MEDLINE | ID: mdl-25377868

ABSTRACT

Pentachlorophenol and other chlorinated phenols are highly toxic ubiquitous environmental pollutants. Using gas chromatographic analysis we determined that Dehalococcoides mccartyi strain JNA in pure culture dechlorinated pentachlorophenol to 3,5-dichlorophenol (DCP) via removal of the ortho and para chlorines in all of the three possible pathways. In addition, JNA dechlorinated 2,3,4,6-tetrachlorophenol via 2,4,6-trichlorophenol (TCP) and 2,4,5-TCP to 2,4-DCP and 3,4-DCP, respectively, and dechlorinated 2,3,6-TCP to 3-chlorophenol (CP) via 2,5-DCP. JNA converted 2,3,4-TCP to 3,4-DCP and 2,4-DCP by ortho and meta dechlorination, respectively. 2,3-DCP was dechlorinated to 3-CP, and, because cultures using it could be transferred with a low inoculum (0.5 to 1.5% vol/vol), it may act as an electron acceptor to support growth. Using PCR amplification with targeted and degenerate primers followed by cloning and sequencing, we determined that JNA harbors at least 19 reductive dehalogenase homologous (rdh) genes including orthologs of pcbA4 and pcbA5, pceA, and mbrA, but not tceA or vcrA. Many of these genes are shared with D. mccartyi strains CBDB1, DCMB5, GT, and CG5. Strain JNA has previously been shown to extensively dechlorinate the commercial polychlorinated biphenyl (PCB) mixture Aroclor 1260. Collectively the data suggest that strain JNA may be well adapted to survive in sites contaminated with chlorinated aromatics and may be useful for in situ bioremediation.


Subject(s)
Bacteria/enzymology , Bacteria/genetics , Chlorophenols/metabolism , Bacteria/metabolism , Biodegradation, Environmental , Chlorophenols/chemistry , DNA Primers/metabolism , Environmental Pollutants/metabolism , Gene Expression Regulation, Bacterial/physiology , Molecular Structure , Polymerase Chain Reaction/methods
17.
Am Heart J Plus ; 382024 Feb.
Article in English | MEDLINE | ID: mdl-38434252

ABSTRACT

Objective: Patients who survive critical illness endure complex physical and mental health conditions, referred to as post-intensive care syndrome (PICS). The University of Michigan's post-intensive cardiac care outpatient long-term outreach (PICCOLO) clinic is designed for patients recently admitted to the coronary care unit (CCU). The long-term goal of this clinic is to understand post-CCU patients' needs and design targeted interventions to reduce their morbidity and mortality post-discharge. As a first step toward this goal, we aimed to define the post-discharge needs of CCU survivors. Design setting particpants: We retrospectively reviewed case-mix data (including rates of depression, PTSD, disability, and cognitive abnormalities) and health outcomes for patients referred to the PICCOLO clinic from July 1, 2018, through June 30, 2021 at Michigan Medicine. Results: Of the 134 referred patients meeting inclusion criteria, 74 (55 %) patients were seen in the PICCOLO clinic within 30 days of discharge. Patients seen in the clinic frequently screened positive for depression (PHQ-2 score ≥3, 21.4 %) and cognitive impairment (MOCA <26, 38.8 %). Further, patients also reported high rates of physical difficulty (mean WHODAS 2.0 score 28.4 %, consistent with moderate physical difficulty). Consistent with medical intensive care unit (ICU) patients, CCU survivors experience PICS. Conclusion: This work highlights the feasibility of an outpatient care model and the need to leverage information gathered from this care model to develop treatment strategies and pathways to address symptoms of PICS in CCU survivors, including depression, cognitive impairment, and physical disability.

18.
Nat Commun ; 15(1): 4857, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849365

ABSTRACT

Reticulocyte-binding protein homologue 5 (RH5), a leading blood-stage Plasmodium falciparum malaria vaccine target, interacts with cysteine-rich protective antigen (CyRPA) and RH5-interacting protein (RIPR) to form an essential heterotrimeric "RCR-complex". We investigate whether RCR-complex vaccination can improve upon RH5 alone. Using monoclonal antibodies (mAbs) we show that parasite growth-inhibitory epitopes on each antigen are surface-exposed on the RCR-complex and that mAb pairs targeting different antigens can function additively or synergistically. However, immunisation of female rats with the RCR-complex fails to outperform RH5 alone due to immuno-dominance of RIPR coupled with inferior potency of anti-RIPR polyclonal IgG. We identify that all growth-inhibitory antibody epitopes of RIPR cluster within the C-terminal EGF-like domains and that a fusion of these domains to CyRPA, called "R78C", combined with RH5, improves the level of in vitro parasite growth inhibition compared to RH5 alone. These preclinical data justify the advancement of the RH5.1 + R78C/Matrix-M™ vaccine candidate to Phase 1 clinical trial.


Subject(s)
Antibodies, Monoclonal , Antibodies, Protozoan , Antigens, Protozoan , Malaria Vaccines , Malaria, Falciparum , Plasmodium falciparum , Protozoan Proteins , Malaria Vaccines/immunology , Malaria Vaccines/administration & dosage , Animals , Plasmodium falciparum/immunology , Protozoan Proteins/immunology , Female , Malaria, Falciparum/prevention & control , Malaria, Falciparum/immunology , Malaria, Falciparum/parasitology , Antigens, Protozoan/immunology , Rats , Antibodies, Protozoan/immunology , Antibodies, Monoclonal/immunology , Humans , Epitopes/immunology , Carrier Proteins/immunology , Carrier Proteins/metabolism
19.
J Biol Chem ; 287(45): 37949-63, 2012 Nov 02.
Article in English | MEDLINE | ID: mdl-22984267

ABSTRACT

The malaria parasite replicates within an intraerythrocytic parasitophorous vacuole (PV). The PV and host cell membranes eventually rupture, releasing merozoites in a process called egress. Certain inhibitors of serine and cysteine proteases block egress, indicating a crucial role for proteases. The Plasmodium falciparum genome encodes nine serine-repeat antigens (SERAs), each of which contains a central domain homologous to the papain-like (clan CA, family C1) protease family. SERA5 and SERA6 are indispensable in blood-stage parasites, but the function of neither is known. Here we show that SERA6 localizes to the PV where it is precisely cleaved just prior to egress by an essential serine protease called PfSUB1. Mutations that replace the predicted catalytic Cys of SERA6, or that block SERA6 processing by PfSUB1, could not be stably introduced into the parasite genomic sera6 locus, indicating that SERA6 is an essential enzyme and that processing is important for its function. We demonstrate that cleavage of SERA6 by PfSUB1 converts it to an active cysteine protease. Our observations reveal a proteolytic activation step in the malarial PV that may be required for release of the parasite from its host erythrocyte.


Subject(s)
Cysteine Proteases/metabolism , Plasmodium falciparum/enzymology , Protozoan Proteins/metabolism , Subtilisins/metabolism , Amino Acid Sequence , Binding Sites/genetics , Blotting, Western , Cysteine Proteases/genetics , Enzyme Activation , Erythrocytes/parasitology , Host-Parasite Interactions , Malaria, Falciparum/blood , Malaria, Falciparum/parasitology , Microscopy, Immunoelectron , Molecular Sequence Data , Mutation , Plasmodium falciparum/genetics , Plasmodium falciparum/physiology , Proteolysis , Protozoan Proteins/genetics , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Substrate Specificity , Subtilisins/genetics , Vacuoles/enzymology , Vacuoles/ultrastructure
20.
Am J Kidney Dis ; 61(4): 608-11, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23219109

ABSTRACT

Transplanting a kidney from a hepatitis B surface antigen (HBsAg)-positive donor to an HBsAg-negative recipient who is naturally immune has been successful in countries endemic for hepatitis B virus (HBV). However, in most of these cases, the donors were deceased. We present a report of a successful HBsAg-discordant kidney transplantation in the United States; in this case, a living donor kidney was transplanted to a vaccinated recipient. The wife of a 58-year-old HBsAg-negative man volunteered to donate a kidney to her husband. She had chronic hepatitis B but undetectable HBV DNA. She tested positive for HBsAg and antibody to hepatitis B core antigen, but hepatitis B e antigen was undetectable. The recipient failed to develop an antibody response to 3 doses of intramuscular recombinant HBV vaccine given in consecutive months. Immunity was induced by using biweekly intradermal vaccine. However, antibody titer tapered to <10 mIU/mL over 14 months. An intramuscular booster vaccine resulted in a prolonged anamnestic response, allowing for successful living unrelated donor transplantation. During the 10 years since transplantation, the patient has continued to have normal liver function, with undetectable HBsAg and HBV DNA. Antibody titers to HBsAg slowly decreased to 5.8 mIU/mL during the 10 years. Transplant function has been well preserved. This approach to inducing long-term immunity for transplantation merits further study in the United States.


Subject(s)
Adaptive Immunity , Hepatitis B Antibodies/immunology , Hepatitis B Surface Antigens/immunology , Hepatitis B Vaccines/administration & dosage , Kidney Transplantation/immunology , Living Donors , Humans , Immunization, Secondary , Injections, Intradermal , Male , Middle Aged
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