Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 185
Filter
1.
medRxiv ; 2023 May 10.
Article in English | MEDLINE | ID: mdl-37162985

ABSTRACT

Background: Congenital toxoplasmosis is a treatable, preventable disease, but untreated causes death, prematurity, loss of sight, cognition and motor function, and substantial costs worldwide. Methods/Findings: In our ongoing USA feasibility/efficacy clinical trial, data collated with other ongoing and earlier published results proved high performance of an Immunochromatographic-test(ICT) that enables accurate, rapid diagnosis/treatment, establishing new paradigms for care. Overall results from patient blood and/or serum samples tested with ICT compared with gold-standard-predicate-test results found ICT performance for 4606 sera/1876 blood, 99.3%/97.5% sensitive and 98.9%/99.7% specific. However, in the clinical trial the FDA-cleared-predicate test initially caused practical, costly problems due to false-positive-IgM results. For 58 persons, 3/43 seronegative and 2/15 chronically infected persons had false positive IgM predicate tests. This caused substantial anxiety, concerns, and required costly, delayed confirmation in reference centers. Absence of false positive ICT results contributes to solutions: Lyon and Paris France and USA Reference laboratories frequently receive sera with erroneously positive local laboratory IgM results impeding patient care. Therefore, thirty-two such sera referred to Lyon's Reference laboratory were ICT-tested. We collated these with other earlier/ongoing results: 132 of 137 USA or French persons had false positive local laboratory IgM results identified correctly as negative by ICT. Five false positive ICT results in Tunisia and Marseille, France, emphasize need to confirm positive ICT results with Sabin-Feldman-Dye-test or western blot. Separate studies demonstrated high performance in detecting acute infections, meeting FDA, CLIA, WHO ASSURED, CEMark criteria and patient and physician satisfaction with monthly-gestational-ICT-screening. Conclusions/Significance: This novel paradigm using ICT identifies likely false positives or raises suspicion that a result is truly positive, rapidly needing prompt follow up and treatment. Thus, ICT enables well-accepted gestational screening programs that facilitate rapid treatment saving lives, sight, cognition and motor function. This reduces anxiety, delays, work, and cost at point-of-care and clinical laboratories. Author's Summary: Toxoplasmosis is a major health burden for developed and developing countries, causing damage to eyes and brain, loss of life and substantial societal costs. Prompt diagnosis in gestational screening programs enables treatment, thereby relieving suffering, and leading to > 14-fold cost savings for care. Herein, we demonstrate that using an ICT that meets WHO ASSURED-criteria identifying persons with/without antibody to Toxoplasma gondii in sera and whole blood with high sensitivity and specificity, is feasible to use in USA clinical practice. We find this new approach can help to obviate the problem of detection of false positive anti- T.gondii IgM results for those without IgG antibodies to T.gondii when this occurs in present, standard of care, predicate USA FDA cleared available assays. Thus, this accurate test facilitates gestational screening programs and a global initiative to diagnose and thereby prevent and treat T.gondii infection. This minimizes likelihood of false positives (IgG and/or IgM) while maintaining maximum sensitivity. When isolated IgM antibodies are detected, it is necessary to confirm and when indicated continue follow up testing in ∼2 weeks to establish seroconversion. Presence of a positive ICT makes it likely that IgM is truly positive and a negative ICT makes it likely that IgM will be a false positive without infection. These results create a new, enthusiastically-accepted, precise paradigm for rapid diagnosis and validation of results with a second-line test. This helps eliminate alarm and anxiety about false-positive results, while expediting needed treatment for true positive results and providing back up distinguishing false positive tests.

2.
Exp Physiol ; 105(9): 1440-1443, 2020 09.
Article in English | MEDLINE | ID: mdl-32648363

ABSTRACT

NEW FINDINGS: What is the topic of this review? The review discusses how eosinophils can contribute to the function of perivascular adipose tissue and explores the mechanisms involved. What advances does it highlight? Understanding the communication between the cell populations that constitute perivascular adipose tissue function is important for exploring therapeutic options in the treatment of obesity-related cardiovascular complications. This article highlights that eosinophils are able to contribute directly to healthy perivascular adipose tissue function. These immune cells contribute to adrenergic signalling and nitric oxide- and adiponectin-dependent mechanisms in perivascular adipose tissue. ABSTRACT: Perivascular adipose tissue is a heterogeneous tissue that surrounds most blood vessels in the body. This review focuses on the contribution of eosinophils located within the adipose tissue to vascular contractility. A high-fat diet reduces the number of these immune cells within perivascular adipose tissue, and this loss is linked to an increase in vascular contractility and hypertension. We explored the mechanisms by which eosinophils contribute to this function using genetically modified mice, ex vivo assessment of contractility and pharmacological tools. We found that eosinophils contribute to adrenergic signalling and nitric oxide- and adiponectin-dependent mechanisms in perivascular adipose tissue. It is now important to explore whether manipulation of these pathways in obesity can alleviate cardiovascular complications, in order to determine whether eosinophils are a valid target for obesity-related disease.


Subject(s)
Adipose Tissue/metabolism , Eosinophils/metabolism , Obesity/metabolism , Adiponectin/metabolism , Animals , Diet, High-Fat , Hypertension/physiopathology , Mice , Nitric Oxide/metabolism , Signal Transduction
3.
HNO ; 68(7): 534-538, 2020 Jul.
Article in German | MEDLINE | ID: mdl-31758201

ABSTRACT

Schwannomas of the eighth cranial nerve are benign tumours commonly found in the internal auditory meatus or in the cerebellopontine angle. In most cases, they arise from the inferior or vestibular portion of the vestibular nerve. Rarely, these tumours present in the inner ear and are then called intralabyrinthine schwannomas. Bilateral schwannomas are known in neurofibromatosis type 2 (NF2). Bilateral and ipsilateral, multilocular sporadic schwannomas of the eighth cranial nerve have been described as extremely rare findings. This report describes the first case of bilateral sporadic intracochlear schwannomas in a patient with no genetic or clinical features of NF2.


Subject(s)
Neurilemmoma , Neurofibromatosis 2 , Neuroma, Acoustic , Cerebellopontine Angle , Humans , Neurilemmoma/complications , Neurilemmoma/diagnosis , Neurofibromatosis 2/complications , Neurofibromatosis 2/diagnosis , Neuroma, Acoustic/complications , Neuroma, Acoustic/diagnosis , Vestibular Nerve
4.
HNO ; 68(Suppl 1): 60-64, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31598774

ABSTRACT

Schwannomas of the eighth cranial nerve are benign tumours commonly found in the internal auditory meatus or in the cerebellopontine angle. In most cases, they arise from the inferior or vestibular portion of the vestibular nerve. Rarely, these tumours present in the inner ear and are then called intralabyrinthine schwannomas. Bilateral schwannomas are known in neurofibromatosis type 2 (NF2). Bilateral and ipsilateral, multilocular sporadic schwannomas of the eighth cranial nerve have been described as extremely rare findings. This report describes the first case of bilateral sporadic intracochlear schwannomas in a patient with no genetic or clinical features of NF2.


Subject(s)
Neurilemmoma , Neurofibromatosis 2 , Neuroma, Acoustic , Female , Humans , Middle Aged , Neurilemmoma/complications , Neurofibromatosis 2/complications , Neuroma, Acoustic/complications , Vestibular Nerve
5.
Vet Comp Oncol ; 15(2): 441-449, 2017 Jun.
Article in English | MEDLINE | ID: mdl-26762869

ABSTRACT

Experimental toxicological studies in laboratory animals and epidemiological human studies have reported a possible association between water fluoridation and osteosarcoma (OSA). To further explore this possibility, a case-control study of individual dogs evaluated by the UC Davis Veterinary Medical Teaching Hospital was conducted using ecologic data on water fluoridation based on the owner's residence. The case group included 161 dogs with OSA diagnosed between 2008-2012. Two cancer control groups included dogs diagnosed with lymphoma (LSA) or hemangiosarcoma (HSA) during the same period (n = 134 and n = 145, respectively). Dogs with OSA were not significantly more likely to live in an area with optimized fluoride in the water than dogs with LSA or HSA. Additional analyses within OSA patients also revealed no significant differences in age, or skeletal distribution of OSA cases relative to fluoride status. Taken together, these analyses do not support the hypothesis that optimal fluoridation of drinking water contributes to naturally occurring OSA in dogs.


Subject(s)
Bone Neoplasms/veterinary , Dog Diseases/chemically induced , Fluoridation/adverse effects , Osteosarcoma/veterinary , Animals , Bone Neoplasms/chemically induced , Bone Neoplasms/epidemiology , Case-Control Studies , Dog Diseases/epidemiology , Dogs , Female , Incidence , Male , Osteosarcoma/chemically induced , Osteosarcoma/epidemiology
6.
Vet Comp Oncol ; 15(3): 1087-1100, 2017 Sep.
Article in English | MEDLINE | ID: mdl-27333821

ABSTRACT

Adjuvant chemotherapy improves survival time in dogs receiving adequate local control for appendicular osteosarcoma, but most dogs ultimately succumb to metastatic disease. The fluoroquinolone antibiotic enrofloxacin has been shown to inhibit survival and proliferation of canine osteosarcoma cells in vitro. Others have reported that fluoroquinolones may modulate cellular responses to DNA damaging agents and that these effects may be differentially mediated by p53 activity. We therefore determined p53 status and activity in three canine osteosarcoma cell lines and examined the effects of enrofloxacin when used alone or in combination with doxorubicin or carboplatin chemotherapy. Moresco and Abrams canine osteosarcoma cell lines contained mutations in p53, while no mutations were identified in the D17 cells or in a normal canine osteoblast cell line. The addition of enrofloxacin to either doxorubicin or carboplatin resulted in further reductions in osteosarcoma cell viability; this effect was apparent regardless of p53 mutational status or downstream activity.


Subject(s)
Antineoplastic Agents/therapeutic use , Bone Neoplasms/veterinary , Dog Diseases/drug therapy , Fluoroquinolones/therapeutic use , Osteosarcoma/veterinary , Tumor Suppressor Protein p53/genetics , Animals , Antineoplastic Agents/administration & dosage , Bone Neoplasms/drug therapy , Bone Neoplasms/genetics , Carboplatin/administration & dosage , Carboplatin/therapeutic use , Cell Line, Tumor , Chemotherapy, Adjuvant/veterinary , Dog Diseases/genetics , Dogs , Doxorubicin/administration & dosage , Doxorubicin/therapeutic use , Enrofloxacin , Fluoroquinolones/administration & dosage , Osteosarcoma/drug therapy , Osteosarcoma/genetics
7.
Phytopathology ; 106(10): 1105-1116, 2016 10.
Article in English | MEDLINE | ID: mdl-27314624

ABSTRACT

Advances in next-generation sequencing (NGS) allow for rapid development of genomics resources needed to generate molecular diagnostics assays for infectious agents. NGS approaches are particularly helpful for organisms that cannot be cultured, such as the downy mildew pathogens, a group of biotrophic obligate oomycetes that infect crops of economic importance. Unlike most downy mildew pathogens that are highly host-specific, Pseudoperonospora cubensis causes disease on a broad range of crops belonging to the family Cucurbitaceae. In this study, we identified candidate diagnostic markers for P. cubensis by comparing NGS data from a diverse panel of P. cubensis and P. humuli isolates, two very closely related oomycete species. P. cubensis isolates from diverse hosts and geographical regions in the United States were selected for sequencing to ensure that candidates were conserved in P. cubensis isolates infecting different cucurbit hosts. Genomic regions unique to and conserved in P. cubensis isolates were identified through bioinformatics. These candidate regions were then validated using PCR against a larger collection of isolates from P. cubensis, P. humuli, and other oomycetes. Overall seven diagnostic markers were found to be specific to P. cubensis. These markers could be used for pathogen diagnostics on infected tissue, or adapted for monitoring airborne inoculum with real-time PCR and spore traps.


Subject(s)
Cucurbitaceae/parasitology , Genomics , High-Throughput Nucleotide Sequencing/methods , Oomycetes/isolation & purification , Plant Diseases/parasitology , Genetic Markers/genetics , Host Specificity , Oomycetes/genetics , Plant Leaves/parasitology , Real-Time Polymerase Chain Reaction , Sequence Analysis, DNA , Species Specificity
8.
Chem Commun (Camb) ; 52(51): 7943-6, 2016 Jun 28.
Article in English | MEDLINE | ID: mdl-27253678

ABSTRACT

Mono-, di- and trisaccharide derivatives of 1,2-unsaturated N-acetyl-d-glucal have been synthesized and shown to function as tight-binding inhibitors/slow substrates of representative hexosaminidases. Turnover is slow and not observed in the thioamide analogue, allowing determination of the 3-dimensional structure of the complex. Inhibition is insensitive to pH and to mutation of key catalytic residues, consistent with the uncharged character of the inhibitor. These properties could render this inhibitor class less prone to development of resistance.


Subject(s)
Deoxyglucose/analogs & derivatives , Enzyme Inhibitors/pharmacology , Hexosaminidases/antagonists & inhibitors , Binding Sites/drug effects , Biocatalysis , Deoxyglucose/chemical synthesis , Deoxyglucose/chemistry , Deoxyglucose/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Hexosaminidases/metabolism , Hydrogen-Ion Concentration , Models, Molecular , Molecular Structure
9.
Chem Commun (Camb) ; 51(14): 2933-5, 2015 Feb 18.
Article in English | MEDLINE | ID: mdl-25587931

ABSTRACT

Mechanism-based inhibition of influenza neuraminidases by difluorosialic acids (DFSA) is not only rendered highly specific by incorporation of 4-amino or 4-guanidine substituents but also the half-life for reactivation is greatly increased. Measurement of rate constants for spontaneous hydrolysis of a series of such substituted DFSAs reveals, surprisingly, that inherent inductive effects play very little role in this rate reduction and that interactions with the enzyme are more important.


Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Neuraminidase/antagonists & inhibitors , Orthomyxoviridae/enzymology , Sialic Acids/chemistry , Sialic Acids/pharmacology
10.
Vet Comp Oncol ; 13(3): 157-65, 2015 Sep.
Article in English | MEDLINE | ID: mdl-23489591

ABSTRACT

Paraneoplastic hypertrophic osteopathy (pHO) is known to occur in both canine and human cancer patients. While the pathology of pHO is well-described in the dog, very little information exists regarding the true clinical presentation of dogs affected with pHO. The primary objective of this study was to provide a more comprehensive clinical picture of pHO. To this end, we retrospectively identified 30 dogs and recorded data regarding presenting complaints and physical examination (PE) findings on the date of pHO diagnosis. As a secondary objective, any blood test results were also collected from the computerized records. The most common clinical signs included leg swelling, ocular discharge and/or episcleral injection, lameness, and lethargy. The most common haematological and serum biochemical abnormalities included anaemia, neutrophilia and elevated alkaline phosphatase. In addition to presenting a more detailed clinical description of pHO in the dog, these data support the previously described haematological, serum biochemical and PE abnormalities published in individual case reports.


Subject(s)
Dog Diseases/diagnosis , Osteoarthropathy, Secondary Hypertrophic/veterinary , Paraneoplastic Syndromes/veterinary , Animals , Autopsy/veterinary , California , Dog Diseases/blood , Dog Diseases/diagnostic imaging , Dogs , Electronic Health Records , Female , Lameness, Animal/complications , Lung Neoplasms/complications , Lung Neoplasms/veterinary , Male , Neoplasms/complications , Osteoarthropathy, Secondary Hypertrophic/blood , Osteoarthropathy, Secondary Hypertrophic/diagnosis , Paraneoplastic Syndromes/blood , Paraneoplastic Syndromes/diagnosis , Radiography , Retrospective Studies , Schools, Veterinary
11.
Science ; 344(6179): 90-3, 2014 Apr 04.
Article in English | MEDLINE | ID: mdl-24700858

ABSTRACT

Redesigning lignin, the aromatic polymer fortifying plant cell walls, to be more amenable to chemical depolymerization can lower the energy required for industrial processing. We have engineered poplar trees to introduce ester linkages into the lignin polymer backbone by augmenting the monomer pool with monolignol ferulate conjugates. Herein, we describe the isolation of a transferase gene capable of forming these conjugates and its xylem-specific introduction into poplar. Enzyme kinetics, in planta expression, lignin structural analysis, and improved cell wall digestibility after mild alkaline pretreatment demonstrate that these trees produce the monolignol ferulate conjugates, export them to the wall, and use them during lignification. Tailoring plants to use such conjugates during cell wall biosynthesis is a promising way to produce plants that are designed for deconstruction.


Subject(s)
Acyltransferases/chemistry , Acyltransferases/genetics , Lignin/chemistry , Lignin/metabolism , Populus/genetics , Populus/metabolism , Acyltransferases/isolation & purification , Angelica sinensis/enzymology , Angelica sinensis/genetics , Cell Wall/chemistry , Cell Wall/metabolism , Coumaric Acids/metabolism , Genes, Plant , Molecular Structure , Plant Roots/enzymology , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Populus/growth & development , Trees/genetics , Trees/metabolism
12.
Case Rep Pediatr ; 2014: 417147, 2014.
Article in English | MEDLINE | ID: mdl-24592350

ABSTRACT

We describe a neonate of 38-week and 6-day gestation born by lower uterine cesarean section for breech presentation, where it was evident on delivery that there was significant edema of the right arm from the deltoid to the distal tips of the fingers. Doppler flow ultrasound revealed extensive arterial thromboembolus. Intravenous heparin was prescribed for three days at a dose of 27.5 U/kg/h, targeting an activated partial thromboplastin time (APTT) of 60-75 seconds, followed by a course of subcutaneous enoxaparin at a dose of 1.8 mg/kg and then 2 mg/kg twice daily, titrated to a factor Xa level of 0.5-1.0 U/mL for another three days. Significant clinical improvement occurred and the child was eventually, discharged on subcutaneous enoxaparin. Magnetic resonance imaging showed multiple intracranial abnormalities. At five months increased upper limb tone, brisk reflexes, and small head circumference were noted. At one year, increased tone and increased paucity of movement on the right side persisted, and some speech delay and visual inattention were noted. Recent follow-up at 16.5 months of age demonstrated a right sided hemiplegia with increased tone and brisk reflexes. We describe the case in detail and review current knowledge regarding the management of arterial thrombosis in the neonate.

13.
Org Biomol Chem ; 12(16): 2592-5, 2014 Apr 28.
Article in English | MEDLINE | ID: mdl-24618676

ABSTRACT

2-Deoxy-2-fluoroglycosides bearing dibenzyl phosphate and phosphonate aglycones were synthesised and tested as covalent inactivators of several retaining α- and ß-glycosidases. ß-d-Gluco-, -manno- and -galacto-configured benzyl-benzylphosphonate derivatives efficiently inactivated ß-gluco-, ß-manno- and ß-galactosidases, while α-gluco- and α-manno-configured phosphate and phosphonate derivatives served instead as slow substrates.


Subject(s)
Deoxy Sugars/pharmacology , Esterases/chemistry , Glycoside Hydrolases/antagonists & inhibitors , Organophosphonates/chemistry , Sugar Phosphates/pharmacology , Deoxy Sugars/chemical synthesis , Deoxy Sugars/chemistry , Esterases/metabolism , Glycoside Hydrolases/chemistry , Glycoside Hydrolases/metabolism , Kinetics , Organophosphonates/metabolism , Structure-Activity Relationship , Sugar Phosphates/chemical synthesis , Sugar Phosphates/chemistry
14.
Plant Dis ; 98(7): 1009, 2014 Jul.
Article in English | MEDLINE | ID: mdl-30708904

ABSTRACT

In August of 2013, garlic bulbs (Allium sativum) of the variety Chesnok Red grown and stored under dry conditions by a commercial producer in Buncombe County showed water-soaked, tan to salmon-pink lesions. Lesions on cloves became soft over time, slightly sunken, and had mycelium near the center of the bulb, which is characteristic of Fusarium rots on garlic (1,2). Approximately 10 to 20% of the bulbs inspected in the drying storage room were affected. Surface-sterilized tissue was excised from the margin of lesions on eight bulbs, plated onto acid potato dextrose agar (APDA), and incubated in the dark at room temperature (21°C). White to light pink colonies with abundant aerial mycelium and a purple pigment were obtained from all samples after 2 to 3 days of incubation. Inspection of colony morphology and reproductive structures under a microscope revealed that isolate characteristics were consistent with Fusarium proliferatum (Matsushima) Nirenberg. Microscopic morphological characteristics of the isolate included hyaline, septate hyphae; slender, slightly curved macroconidia with three to five septae produced in sporodochia; curved apical cell; and club-shaped, aseptate microconidia (measuring 3.3 to 8.3 × 1.1 to 1.3 µm) produced in chains by mono and polyphyalides. To further define the identity of the isolate, the beta-tubulin (Btub), elongation factor 1a (EF1a), and internal transcribed spacer (ITS) regions were amplified and sequenced (3). The resulting sequences were compared against the GenBank nucleotide database by using a BLAST alignment, which revealed that the isolate had 100% identity with F. proliferatum for the Btub, EF1a, and ITS regions (GenBank Accession Nos. AF291055.1, JX118976.1, and HF930594.1, respectively). Sequences for the isolate were deposited in GenBank under accessions KJ128963, KJ128964, and KJ128965. While there have been other reports of F. proliferatum causing bulb rot of garlic in the United States (1), to our knowledge, this is the first report in North Carolina. The finding is significant since F. proliferatum can produce a broad range of mycotoxins, including fumonisins, when infecting its host, which is a concern for food safety in Allium crops. References: (1) F. M. Dugan et al. Plant Pathol. 52:426, 2003. (2) L. J. du Toit and F. M. Dugan. Page 15 in: Compendium of Onion and Garlic Diseases and Pests. H. F. Schwartz and S. K. Mohan, eds. The American Phytopathological Society, St. Paul, MN, 2008. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.

15.
Placenta ; 34(1): 82-4, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23195572

ABSTRACT

An adequate blood supply is essential for the maintenance of uterine function and fetal health during parturition. However, labouring uterine contractions will impart compressive forces on small uterine arteries (SUA). We demonstrate that isolated, pressurised rat SUA arteries, pre-constricted with arginine vasopressin or high potassium solution, exhibit regulatory responses to elevations in extravascular pressure (EVP) which maintain internal diameter constant at EVPs of 0-40 mm Hg. This response is endothelium independent and is not modulated by pregnancy. No regulation was observed in calcium free solution. SUA myogenic responses to elevated EVP likely represents a mechanism for limiting reductions in uterine blood flow during uterine contraction.


Subject(s)
Pressure , Uterine Artery/cytology , Uterine Artery/physiology , Animals , Blood Pressure/physiology , Cell Separation , Cells, Cultured , Female , Muscle, Smooth, Vascular/physiology , Organ Culture Techniques , Pregnancy , Primary Cell Culture , Rats , Rats, Sprague-Dawley , Uterine Artery/metabolism , Uterine Contraction/physiology , Uterus/blood supply
16.
Cochlear Implants Int ; 12(2): 124-6, 2011 May.
Article in English | MEDLINE | ID: mdl-21756505

ABSTRACT

OBJECTIVE: This paper reports a case of a patient who has had bilateral cochlear implants that have been manufactured by different cochlear implant companies (Cochlear Corporation and Med-El). METHOD: Comparison of speech perception tests following single implant insertion and bilateral insertion (3 and 12 months). The patient was also interviewed to obtain a subjective opinion on their quality of hearing. RESULTS: The patient reported that their Med-El implant had better sound quality than their Cochlear Corporation implant. The speech perception tests however failed to show any difference. CONCLUSION: Despite no difference found with the objective tests hearing is very subjective and therefore the patient's opinion on the quality of sound is important. It is only a matter of time before other patients are fitted with bilateral cochlear implants from different companies and this information should be collated to allow comparison between manufacturers.


Subject(s)
Cochlear Implantation , Cochlear Implants/classification , Deafness/surgery , Audiometry, Pure-Tone , Cochlear Implants/standards , Deafness/etiology , Deafness/physiopathology , Deafness/psychology , Female , Hearing , Humans , Middle Aged , Speech Perception , Usher Syndromes/complications
17.
Genes Immun ; 11(5): 374-83, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20535134

ABSTRACT

Congenital Toxoplasma gondii infection can result in intracranial calcification, hydrocephalus and retinochoroiditis. Acquired infection is commonly associated with ocular disease. Pathology is characterized by strong proinflammatory responses. Ligation of ATP by purinergic receptor P2X(7), encoded by P2RX7, stimulates proinflammatory cytokines and can lead directly to killing of intracellular pathogens. To determine whether P2X(7) has a role in susceptibility to congenital toxoplasmosis, we examined polymorphisms at P2RX7 in 149 child/parent trios from North America. We found association (FBAT Z-scores +/-2.429; P=0.015) between the derived C(+)G(-) allele (f=0.68; OR=2.06; 95% CI: 1.14-3.75) at single-nucleotide polymorphism (SNP) rs1718119 (1068T>C; Thr-348-Ala), and a second synonymous variant rs1621388 in linkage disequilibrium with it, and clinical signs of disease per se. Analysis of clinical subgroups showed no association with hydrocephalus, with effect sizes for associations with retinal disease and brain calcifications enhanced (OR=3.0-4.25; 0.004

Subject(s)
Chorioretinitis/genetics , Genetic Predisposition to Disease/genetics , Receptors, Purinergic P2/genetics , Toxoplasmosis, Congenital/genetics , Adult , Brazil , Child, Preschool , Chorioretinitis/etiology , Female , Genome-Wide Association Study , Haplotypes/genetics , Humans , Inheritance Patterns/genetics , Linkage Disequilibrium , Logistic Models , Male , North America , Polymorphism, Single Nucleotide/genetics , Receptors, Purinergic P2X7 , Toxoplasmosis, Congenital/complications
18.
Placenta ; 30(6): 529-35, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19427692

ABSTRACT

Pregnancy-induced changes in uterine artery function play a critical role in ensuring adequate placental perfusion. Responses of these vessels to pressure (myogenic responsiveness) may contribute to this. The overall myogenic properties of uterine arteries may depend upon the integration of a number of different factors, including effects of pre-constrictor stimuli, and should be considered in terms of both initial and stable diameters both of which may be modulated by pregnancy. This study thus investigated the effects of pre-constriction, the endothelium and pregnancy on responses of isolated rat uterine arteries to changes in intravascular pressure (IvP). The effects on both the immediate transient diameter changes and stable diameters (myogenic tone) were studied. Isolated 3rd order uterine arteries from non-pregnant and days 19-21 pregnant Sprague-Dawley rats were mounted on a pressure myograph and responses to changes in IvP (20-120 mm Hg) examined. Arteries did not exhibit active responses to pressure in the absence of stimulation, however, all showed active myogenic constriction when pre-constricted by depolarization (30 or 60mM KCl) or arginine vasopressin (AVP). Pregnancy enhanced stable levels of myogenic tone with AVP, but not depolarization. This difference was not dependent upon the endothelium. Initial peak diameters were enhanced in arteries from pregnant rats due to endothelium-dependent mechanisms. Thus, both the peak and stable response of isolated rat uterine arteries to pressure can be differentially regulated and thus must both be considered when considering the influence of pressure on uterine artery reactivity during pregnancy.


Subject(s)
Arteries/physiology , Blood Pressure/physiology , Endothelium, Vascular/physiology , Uterus/blood supply , Vasoconstriction/physiology , Animals , Arteries/cytology , Cell Separation , Female , Muscle Contraction/physiology , Pregnancy , Rats , Rats, Sprague-Dawley
19.
Annu Rev Biochem ; 77: 521-55, 2008.
Article in English | MEDLINE | ID: mdl-18518825

ABSTRACT

Glycosyltransferases catalyze glycosidic bond formation using sugar donors containing a nucleoside phosphate or a lipid phosphate leaving group. Only two structural folds, GT-A and GT-B, have been identified for the nucleotide sugar-dependent enzymes, but other folds are now appearing for the soluble domains of lipid phosphosugar-dependent glycosyl transferases. Structural and kinetic studies have provided new insights. Inverting glycosyltransferases utilize a direct displacement S(N)2-like mechanism involving an enzymatic base catalyst. Leaving group departure in GT-A fold enzymes is typically facilitated via a coordinated divalent cation, whereas GT-B fold enzymes instead use positively charged side chains and/or hydroxyls and helix dipoles. The mechanism of retaining glycosyltransferases is less clear. The expected two-step double-displacement mechanism is rendered less likely by the lack of conserved architecture in the region where a catalytic nucleophile would be expected. A mechanism involving a short-lived oxocarbenium ion intermediate now seems the most likely, with the leaving phosphate serving as the base.


Subject(s)
Glycosyltransferases/chemistry , Glycosyltransferases/physiology , Animals , Bacillus subtilis/metabolism , Carbohydrates/chemistry , Enzymes/chemistry , Evolution, Molecular , Genomics , Glycomics , Glycosylation , Humans , Ions , Molecular Conformation , Protein Conformation , Protein Folding , Protein Structure, Secondary
20.
Ultrasound Obstet Gynecol ; 29(2): 170-7, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17221944

ABSTRACT

OBJECTIVE: To describe prenatal ultrasound and autopsy findings in fetuses with OEIS (omphalocele, bladder exstrophy, imperforate anus, spina bifida) complex. METHODS: This was a retrospective study of the nine cases with OEIS complex diagnosed at our center using detailed fetal ultrasound during the last 10 years. We summarized the fetal ultrasound findings that led to the diagnosis and compared them with the autopsy results. RESULTS: All affected fetuses were diagnosed using detailed fetal ultrasound after 16 weeks' gestation. The main prenatal findings were omphalocele, skin-covered lumbosacral neural tube defect, non-visualized bladder and limb defects. Prenatal sonography failed to detect the abnormal genitalia, bladder exstrophy and anal atresia. All cases had abnormalities in a 'diaper distribution', which helped in making the prenatal diagnosis. Eight of the nine couples chose to terminate the pregnancies following multidisciplinary counseling. The pregnancy that was continued was a case with dizygotic twins discordant for OEIS, and the affected fetus died in utero. CONCLUSIONS: The combination of the following ultrasound findings: ventral wall defect, spinal defect and a non-visualized bladder with or without limb defects, are characteristic of OEIS complex. Diagnosis can be made with confidence as early as 16 weeks' gestation, although earlier diagnosis may be possible.


Subject(s)
Abnormalities, Multiple , Anus, Imperforate , Bladder Exstrophy , Hernia, Umbilical , Spinal Dysraphism , Abnormalities, Multiple/diagnostic imaging , Abnormalities, Multiple/pathology , Abortion, Induced , Adult , Anus, Imperforate/diagnostic imaging , Anus, Imperforate/pathology , Autopsy , Bladder Exstrophy/diagnostic imaging , Bladder Exstrophy/pathology , Diseases in Twins/diagnostic imaging , Diseases in Twins/pathology , Female , Hernia, Umbilical/diagnostic imaging , Hernia, Umbilical/pathology , Humans , Pregnancy , Pregnancy Trimester, Second , Retrospective Studies , Spinal Dysraphism/diagnostic imaging , Spinal Dysraphism/pathology , Ultrasonography, Prenatal/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...