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1.
Allergy ; 72(11): 1728-1736, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28439905

ABSTRACT

BACKGROUND: Dermatophagoides farinae is a source of airborne house dust mite (HDM) allergens. We elucidated IgE-reactive allergens from D. farinae by two-dimensional immunoblotting-based allergenome analysis, and identified one new allergen, named Der f 35, that possesses IgE-binding capacity comparable to that of Der f 2. The aim of this study was to clarify the allergenic capacity of new HDM allergen Der f 35. METHODS: We cloned der f 35 from D. farinae mRNA and produced recombinant Der f 35 in Escherichia coli. The IgE-binding capacity of Der f 35 and its cross-reactivity with group 2 allergens from D. farinae and Psoroptes ovis were determined by enzyme-linked immunosorbent assay (ELISA) and ELISA inhibition assays, respectively. RESULTS: The deduced amino acid sequence for der f 35, which possesses the MD-2-related lipid-recognition domain, showed higher identity with group 2 allergens from P. ovis (61.5%) and Blomia tropicalis (50.7%) than with Der f 2 (40.8%). Der f 35 showed IgE-binding frequencies of 77.5% (31/40) for the native form upon allergenome analysis and 51.4% (18/35) for recombinant structure by ELISA. Der f 35 showed cross-reactivity with Der f 2 and Pso o 2 in reaction with HDM-allergic patients' IgE by ELISA inhibition assay. CONCLUSION: Der f 35 is a candidate major allergen from D. farinae, which is more similar to group 2 allergens from sheep scab mite and storage mites. Der f 35 could be responsible for the cross-reactivity among group 2 mite allergens.


Subject(s)
Allergens/immunology , Antigens, Dermatophagoides/immunology , Cross Reactions/immunology , Mites/immunology , Animals , Arthropod Proteins/immunology , Dermatophagoides farinae/immunology , Immunoglobulin E/metabolism , Psoroptidae/immunology , Sequence Analysis, Protein , Sheep
2.
J Vet Cardiol ; 51: 24-34, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38071798

ABSTRACT

INTRODUCTION: Interventricular inflow time difference (IVID), which is defined as the time interval between the opening of the mitral valve and the opening of the tricuspid valve, hold prognostic value in human patients with heart failure. Few reports regarding IVID are available in dogs. ANIMALS: Ninety dogs with myxomatous mitral valve disease (MMVD) and 47 dogs without heart disease. Dogs with MMVD received unstandardized therapy based on the stage of disease. MATERIALS AND METHODS: This was a prospective cohort study. Dogs were classified into two groups based on IVID: tricuspid opening preceding mitral opening (TOP) and mitral opening preceding tricuspid opening (MOP). The potential influence of the MOP group at enrollment on the primary outcome (cardiac-related death) was determined by Kaplan-Meier analysis. RESULTS: Almost all dogs without heart disease (97.9%) were classified in the TOP group. Twenty-nine dogs (32.2%) were classified in the MOP group. Left heart size, transmitral early diastolic inflow velocity, and right ventricular Tei index were significantly greater in the MOP group compared to those in the TOP group. Cardiac-related death were observed in 34 dogs (40.5%). The dogs in the MOP group at initial examination had shorter survival times than those in the TOP group (586 days vs. >1,831 days; 95% confidence interval, 237-714 days vs. 1,037 days to >1,831 days; P<0.001). CONCLUSIONS: Interventricular inflow time difference is potentially useful for prognostic assessments in dogs with MMVD. Further prospective studies that quantify the repeatability and influence of therapy on IVID are needed.


Subject(s)
Dog Diseases , Heart Valve Diseases , Humans , Dogs , Animals , Mitral Valve/diagnostic imaging , Prospective Studies , Heart Valve Diseases/veterinary , Tricuspid Valve , Echocardiography, Doppler/veterinary , Dog Diseases/diagnostic imaging
3.
J Appl Microbiol ; 114(6): 1763-71, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23473548

ABSTRACT

AIMS: To determine whether the carotenoid production improves stress tolerance of lactic acid bacteria, the cloned enterococcal carotenoid biosynthesis genes were expressed in Lactococcus lactis ssp. cremoris MG1363, and the survival rate of carotenoid-producing engineered MG1363 strain under stress condition was investigated. METHODS AND RESULTS: We cloned carotenoid biosynthesis genes from yellow-pigmented Enterococcus gilvus. The cloned genes consisted of crtN and crtM and its promoter region were inserted into the shuttle vector pRH100, and the resulting plasmid was named pRC. The cloned crtNM was expressed using pRC in noncarotenoid-producing L. lactis ssp. cremoris MG1363. The expression of crtNM led to the production of C30 carotenoid 4,4'-diaponeurosporene. After exposure to 32 mmol l(-1) H2 O2 , low pH (1.5, acidified with HCl), 20% bile acid and 12 mg ml(-1) lysozyme, the survival rates of the MG1363 strain harbouring pRC were 18.7-, 6.8-, 8.8- and 4.4-fold higher, respectively, than those of MG1363 strain harbouring the empty vector pRH100. CONCLUSIONS: The expression of carotenoid biosynthesis genes from Ent. gilvus improves the multistress tolerance of L. lactis. SIGNIFICANCE AND IMPACT OF THE STUDY: First report of the improvement of multistress tolerance of lactic acid bacteria by the introduction of genes for carotenoid production.


Subject(s)
Carotenoids/biosynthesis , Enterococcus/genetics , Lactococcus lactis/genetics , Base Sequence , Gene Expression , Genes, Bacterial , Lactococcus lactis/metabolism , Microbial Viability , Molecular Sequence Data , Stress, Physiological , Triterpenes
4.
J Appl Microbiol ; 112(1): 138-46, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22040451

ABSTRACT

AIMS: To develop an in vivo system that could quantitatively evaluate the therapeutic effects of antifungal drugs using a silkworm infection model with Cryptococcus neoformans. METHODS AND RESULTS: Silkworms reared at 37°C died after an injection of viable serotype A C. neoformans fungus into the haemolymph. The serotype A C. neoformans, which is known to have higher mammal pathogenicity than the serotype D, was also more virulent against the silkworm. Furthermore, the deletion mutants of genes gpa1, pka1 and cna1, which are genes known to be necessary for the pathogenesis in mammals, showed an increase in the number of fungal cells necessary to kill half of the silkworm population (LD(50) value). Antifungal drugs, amphotericin B, flucytosine, fluconazole and ketoconazole, showed therapeutic effects in silkworms infected with C. neoformans. However, amphotericin B was not therapeutically effective when injected into the silkworm intestine, comparable to the fact that amphotericin B is not absorbed by the intestine in mammals. CONCLUSIONS: The silkworm-C. neoformans infection model is useful for evaluating the therapeutic effects of antifungal drugs. SIGNIFICANCE AND IMPACT OF THE STUDY: The silkworm infection model has various advantages for screening antifungal drug candidates. We can also elucidate the cryptococcal pathogenesis and evaluate the in vivo pharmacokinetics and toxicity of each drug.


Subject(s)
Antifungal Agents/pharmacology , Bombyx/microbiology , Cryptococcus neoformans/drug effects , Cryptococcus neoformans/physiology , Microbial Sensitivity Tests/methods , Animals , Cryptococcus neoformans/genetics , Cryptococcus neoformans/pathogenicity , Temperature
5.
Kyobu Geka ; 65(5): 347-52; discuaaion 352-6, 2012 May.
Article in Japanese | MEDLINE | ID: mdl-22569490

ABSTRACT

BACKGROUND: Aortic root replacement (ARR) combined with aortic arch replacement (AAR) is an invasive procedure even in elective cases. Nevertheless, such combined operations are often mandatory in acute type A aortic dissection. We examined whether emergency operation might have further incremental risks compared with elective surgery in this type of operations. METHODS: Forty-six cases of ARR combined with AAR were divided into 2 groups, the emergency (EM) group and the elective (EL) group. The EM group consisted of 10 cases of acute type A aortic dissection, whereas the EL group of 36:23 of chronic aortic dissection and 13 of true aneurysm. RESULTS: There were no statistical differences between the 2 groups in the durations of aortic crossclamp, selective cerebral perfusion and cardiopulmonary bypass. The incidences in the EM and EL groups were as follows:in-hospital death; 0 vs 3( 8%), respiratory failure; 4 (40%) vs 14 (39%), renal failure; 0 vs 6 (17%), IABP requirement; 1 (10%) vs 3 (8%), and cerebral infarction; 0 vs 1 (3%), respectively. CONCLUSION: Early surgical results of emergency ARR combined with AAR were almost equal to those in elective surgery.


Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm/surgery , Aortic Dissection/surgery , Elective Surgical Procedures , Emergencies , Humans
6.
J Vet Cardiol ; 35: 8-13, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33789182

ABSTRACT

A 6-month-old, female, domestic shorthair cat weighing 1.8 kg presented with cardiomegaly seen on radiographs taken at a primary care veterinary center. Echocardiography revealed a single enlarged vessel overriding a ventricular septal defect and severe hypertrophy of the right ventricular free wall. There was no evidence of a pulmonary arterial trunk originating from the heart. The blood flow through the ventricular septal defect exhibited right-to-left shunting. The cat suddenly experienced dyspnea and died at home, and a postmortem examination was performed. A single large vessel was noted leaving the heart, from which the right and left pulmonary arteries arose separately; a main pulmonary artery was absent. There was only one single anomalous coronary ostium that arose from the brachiocephalic artery and divided into two branches. The walls of the extracardiac coronary artery were thick, but neither infarcts nor narrowing was observed within the coronary arteries. There were no abnormalities in the intracardiac coronary artery. These findings revealed a persistent truncus arteriosus with an anomalous coronary artery. A combination of these anomalies might have contributed to the early death of the cat.


Subject(s)
Coronary Vessel Anomalies , Heart Septal Defects, Ventricular , Truncus Arteriosus, Persistent , Animals , Cats , Coronary Vessel Anomalies/diagnostic imaging , Coronary Vessel Anomalies/veterinary , Coronary Vessels , Female , Heart Septal Defects, Ventricular/veterinary , Pulmonary Artery/diagnostic imaging , Truncus Arteriosus, Persistent/diagnostic imaging , Truncus Arteriosus, Persistent/veterinary
7.
Vet Anim Sci ; 14: 100222, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34917853

ABSTRACT

High-yield dairy cows need high energy feed during periods of increased milk production. The transitional feeding to high energy feed increases the risk of developing a variety of metabolic disorders. Here, five Holstein cows were fed a four-stage feeding protocol (3 weeks for each stage) ranging from 54.9 to 73.7% total digestive nutrients (TDN). The purpose of the study was to investigate the effect of lactic acid bacteria on high-energy-fed cows associated with transitional feeding, and to evaluate the effects of probiotics on intestinal bacterial changes and inflammatory responses. Three feed transition periods were established for five cows, and Lactobacillus plantarum RGU-LP1 (LP1) was fed as a probiotic during the high-energy feeding period. The number of lymphocyte subsets such as CD3-, CD4-, and CD8 positive cells decreased in response to the high energy feed. Lipopolysaccharide (LPS)-induced cytokine (IL-1ß and IL-2) gene expression in peripheral blood mononuclear cells (PBMCs) was shown to increase in those animals receiving the high energy feed. However, supplementation with LP1 resulted in an increase in the number of lymphocyte subsets and the expression of IL-1ß and IL-2 were returned to the level at low energy diet. These results suggest that high energy diets induce inflammatory cytokine responses following LPS stimulation, and that the addition of LP1 mitigates these results by regulating the LPS-induced inflammatory reaction. Therefore, the functional lactic acid bacteria LP1 is expected to regulate inflammation resulting from high energy feeding, and this probiotic could be applied to support inflammatory regulation in high-yield dairy cows.

8.
J Food Prot ; 73(4): 752-7, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20377967

ABSTRACT

The majority of the seed sprout-related outbreaks have been associated with Escherichia coli O157:H7 and Salmonella. Therefore, an effective method for inactivating these organisms on the seeds before sprouting is needed. The current pasteurization method for mung beans in Japan (hot water treatment at 85 degrees C for 10 s) was more effective for disinfecting inoculated E. coli O157:H7, Salmonella, and nonpathogenic E. coli on mung bean seeds than was the calcium hypochlorite treatment (20,000 ppm for 20 min) recommended by the U.S. Food and Drug Administration. Hot water treatment at 85 degrees C for 40 s followed by dipping in cold water for 30 s and soaking in chlorine water (2,000 ppm) for 2 h reduced the pathogens to undetectable levels, and no viable pathogens were found in a 25-g enrichment culture and during the sprouting process. Practical tests using a working pasteurization machine with nonpathogenic E. coli as a surrogate produced similar results. The harvest yield of the treated seed was within the acceptable range. These treatments could be a viable alternative to the presently recommended 20,000-ppm chlorine treatment for mung bean seeds.


Subject(s)
Disinfectants/pharmacology , Fabaceae/microbiology , Food Contamination/analysis , Food Handling/methods , Seeds/microbiology , Calcium Compounds/pharmacology , Chlorine/pharmacology , Colony Count, Microbial , Consumer Product Safety , Escherichia coli/drug effects , Escherichia coli/growth & development , Escherichia coli O157/drug effects , Escherichia coli O157/growth & development , Fabaceae/growth & development , Food Contamination/prevention & control , Food Microbiology , Germination , Hot Temperature , Humans , Japan , Microbial Viability , Salmonella/drug effects , Salmonella/growth & development , Seeds/physiology , Time Factors
9.
J Vet Cardiol ; 32: 16-27, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33080489

ABSTRACT

INTRODUCTION: Pulmonary hypertension (PH) is a progressive and potentially life-threatening disease. Several drugs are used for the treatment of dogs with precapillary PH. Pimobendan is an inotropic drug with phosphodiesterase 3 inhibitory and calcium-sensitizing effects. Pimobendan administration improved right ventricular (RV) function and lowered pulmonary arterial pressure in some human patients with precapillary PH. However, the efficacy of pimobendan in dogs with precapillary PH is unknown. ANIMALS, MATERIAL, AND METHODS: An implantable port device was percutaneously placed in the cranial vena cava of five laboratory beagles. Chronic embolic precapillary PH was induced via the repeated injection of microspheres every 1-2 days. Microsphere injection was continued until systolic pulmonary arterial pressure reached 50 mmHg. Right heart catheterization and echocardiography were performed at baseline and after injections of placebo and pimobendan (0.15 mg/kg). RESULTS: Repeated injections of microspheres caused an increase in pulmonary vascular resistance, a decrease in stroke volume, RV dilation, left ventricular (LV) and RV dysfunction, and RV dyssynchrony as assessed using echocardiography. Compared with placebo, pimobendan improved LV and RV function based on the LV Tei index from 0.48 to 0.38 (p=0.002) and the RV Tei index from 0.76 to 0.61 (p=0.008), as well as the stroke volume index from 29.4 to 36.7 ml/m2 (p=0.012), respectively. CONCLUSIONS: In dog models of chronic PH, intravenous pimobendan effectively improved RV and LV function and increased stroke volume. However, pimobendan administration did not decrease pulmonary arterial pressure or produce hypotension.


Subject(s)
Cardiotonic Agents/therapeutic use , Dog Diseases/drug therapy , Hypertension, Pulmonary/veterinary , Pyridazines/therapeutic use , Ventricular Dysfunction, Right/veterinary , Animals , Cardiotonic Agents/administration & dosage , Cardiotonic Agents/pharmacology , Dog Diseases/diagnostic imaging , Dog Diseases/physiopathology , Dogs , Echocardiography/veterinary , Hypertension, Pulmonary/drug therapy , Infusions, Intravenous , Male , Models, Animal , Prospective Studies , Pyridazines/administration & dosage , Pyridazines/pharmacology , Treatment Outcome , Ventricular Dysfunction, Right/drug therapy , Ventricular Function, Right/drug effects
10.
Diagn Interv Imaging ; 101(9): 555-564, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32278586

ABSTRACT

PURPOSE: The purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: Eighty-nine patients with AIP (65 men, 24 women; mean age, 59.7±13.9 [SD] years; range: 21-83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1±12.3 [SD] years; range: 36-86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5mm thickness/increment) were compared with thick-slices images (3 or 5mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing. RESULTS: The pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8-100%), 83.9% (52:67; 95% CI: 74.7-93.0%) and 77.4% (48/62; 95% CI: 67.0-87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6-100%) and 100% specificity (33/33; 95% CI: 93-100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8-100%) and area under the curve of 0.975 (95% CI: 0.936-1.0). CONCLUSIONS: Radiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.


Subject(s)
Autoimmune Diseases , Autoimmune Pancreatitis , Pancreatic Neoplasms , Pancreatitis , Aged , Autoimmune Diseases/diagnostic imaging , Diagnosis, Differential , Female , Humans , Male , Middle Aged , Pancreatic Ducts , Pancreatic Neoplasms/diagnostic imaging , Pancreatitis/diagnostic imaging , Retrospective Studies , Tomography, X-Ray Computed
11.
Diagn Interv Imaging ; 101(1): 35-44, 2020 01.
Article in English | MEDLINE | ID: mdl-31358460

ABSTRACT

PURPOSE: The purpose of this study was to report procedures developed to annotate abdominal computed tomography (CT) images from subjects without pancreatic disease that will be used as the input for deep convolutional neural networks (DNN) for development of deep learning algorithms for automatic recognition of a normal pancreas. MATERIALS AND METHODS: Dual-phase contrast-enhanced volumetric CT acquired from 2005 to 2009 from potential kidney donors were retrospectively assessed. Four trained human annotators manually and sequentially annotated 22 structures in each datasets, then expert radiologists confirmed the annotation. For efficient annotation and data management, a commercial software package that supports three-dimensional segmentation was used. RESULTS: A total of 1150 dual-phase CT datasets from 575 subjects were annotated. There were 229 men and 346 women (mean age: 45±12years; range: 18-79years). The mean intra-observer intra-subject dual-phase CT volume difference of all annotated structures was 4.27mL (7.65%). The deep network prediction for multi-organ segmentation showed high fidelity with 89.4% and 1.29mm in terms of mean Dice similarity coefficients and mean surface distances, respectively. CONCLUSIONS: A reliable data collection/annotation process for abdominal structures was developed. This process can be used to generate large datasets appropriate for deep learning.


Subject(s)
Abdomen/diagnostic imaging , Deep Learning , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies , Young Adult
12.
J Cell Biol ; 112(5): 915-24, 1991 Mar.
Article in English | MEDLINE | ID: mdl-1999462

ABSTRACT

Two different mRNAs encoding two different nonmuscle myosin heavy chains (MHCs) of approximately 200 kD have been identified in chicken nonmuscle cells, in agreement with the results of Katsuragawa et al. (Katsuragawa, Y., M. Yanagisawa, A. Inoue, and T. Masaki. 1989. Eur. J. Biochem. 184:611-616). In this paper, we quantitate the content of mRNA encoding the two MHCs in a number of different tissues using RNA blot analysis with two specific oligonucleotide probes. Our results show that the relative content of mRNA encoding MHC-A and MHC-B differs in a tissue-dependent manner. Thus the ratio of mRNA encoding MHC-A versus MHC-B varies from greater than 9:1 in spleen and intestinal epithelial cells, to 6:4 in kidney and 2:8 in brain. The effect of serum on MHC mRNA expression was studied in serum-starved cultures of chick embryo fibroblasts. Serum stimulation results in a threefold increase in the mRNA encoding MHC-A and a threefold decrease in mRNA encoding MHC-B. Using SDS polyacrylamide gels, we have separated two nonmuscle MHC isoforms (198 and 196 kD) that can be distinguished from each other by two-dimensional peptide mapping of chymotryptic digests. We provide preliminary evidence that the MHC-A mRNA encodes the 196-kD polypeptide and that the MHC-B mRNA encodes the 198-kD polypeptide.


Subject(s)
Gene Expression , Myosins/genetics , RNA, Messenger/analysis , Animals , Base Sequence , Blood , Blotting, Northern , Blotting, Southern , Brain Chemistry , Cells, Cultured , Chick Embryo , Chickens , Culture Media , Intestines/chemistry , Kidney/chemistry , Molecular Sequence Data , Myosins/metabolism , Oligonucleotide Probes , Organ Specificity/genetics , Peptide Mapping , RNA, Messenger/genetics , Spleen/chemistry
13.
J Cell Biol ; 149(2): 411-22, 2000 Apr 17.
Article in English | MEDLINE | ID: mdl-10769032

ABSTRACT

Axonal growth cone collapse is accompanied by a reduction in filopodial F-actin. We demonstrate here that semaphorin 3A (Sema3A) induces a coordinated rearrangement of Sema3A receptors and F-actin during growth cone collapse. Differential interference contrast microscopy reveals that some sites of Sema3A-induced F-actin reorganization correlate with discrete vacuoles, structures involved in endocytosis. Endocytosis of FITC-dextran by the growth cone is enhanced during Sema3A treatment, and sites of dextran accumulation colocalize with actin-rich vacuoles and ridges of membrane. Furthermore, the Sema3A receptor proteins, neuropilin-1 and plexin, and the Sema3A signaling molecule, rac1, also reorganize to vacuoles and membrane ridges after Sema3A treatment. These data support a model whereby Sema3A stimulates endocytosis by focal and coordinated rearrangement of receptor and cytoskeletal elements. Dextran accumulation is also increased in retinal ganglion cell (RGC) growth cones, in response to ephrin A5, and in RGC and DRG growth cones, in response to myelin and phorbol-ester. Therefore, enhanced endocytosis may be a general principle of physiologic growth cone collapse. We suggest that growth cone collapse is mediated by both actin filament rearrangements and alterations in membrane dynamics.


Subject(s)
Actins/physiology , Glycoproteins/pharmacology , Nerve Growth Factors/pharmacology , Nerve Tissue Proteins/physiology , Neurons/cytology , Neurons/physiology , Actins/drug effects , Animals , Cell Adhesion Molecules/physiology , Cell Membrane/drug effects , Cell Membrane/physiology , Cell Membrane/ultrastructure , Chick Embryo , Endocytosis/drug effects , Endocytosis/physiology , Ganglia, Spinal/cytology , Microscopy, Interference/methods , Nerve Tissue Proteins/drug effects , Neurons/ultrastructure , Neuropilin-1 , Receptors, Cell Surface/physiology , Retina/embryology , Semaphorin-3A , Signal Transduction , rac1 GTP-Binding Protein/physiology
14.
J Food Prot ; 72(3): 631-6, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19343955

ABSTRACT

In this study, the effectiveness of prolonged dry-heat treatment (50 degrees C) alone or in combination with chemical treatments (1% oxalic acid, 0.03% phytic acid, 50% ethanol, electrolyzed acidic water, and electrolyzed alkaline water) in eliminating Escherichia coli O157:H7 on laboratory-inoculated alfalfa, radish, broccoli, and mung bean seeds was compared with that of dry-heat treatment in combination with irradiation treatment. Dry-heat treatment for 17 or 24 h alone could reduce E. coli O157:H7 numbers to below detectable levels in radish, broccoli, and alfalfa seeds, but was unable to reduce the pathogen numbers to below the detectable level in mung bean seeds. In addition, dry-heat treatment for 17 h plus sanitizer treatments were effective in greatly reducing pathogen populations on radish, broccoli, and alfalfa seeds, without compromising the quality of the sprouts, but these treatments did not eliminate the pathogen from radish and alfalfa seeds. Seventeen hours of dry heat followed by a 1.0-kGy dose of irradiation completely eliminated E. coli O157:H7 from radish and mung bean seeds, whereas only a minimum radiation dose of 0.25 kGy was required to completely eliminate the pathogen from broccoli and alfalfa seeds. Dry heat in combination with radiation doses of up to 1.0 kGy did not negatively impact the seed germination rate or length of alfalfa, broccoli, and radish seeds or the length of alfalfa, broccoli, and radish sprouts, but did decrease the length of mung bean sprouts.


Subject(s)
Disinfectants/pharmacology , Escherichia coli O157/drug effects , Food Contamination/analysis , Food Irradiation , Hot Temperature , Vegetables/microbiology , Brassica/microbiology , Colony Count, Microbial , Consumer Behavior , Consumer Product Safety , Dose-Response Relationship, Radiation , Escherichia coli O157/growth & development , Fabaceae/microbiology , Food Microbiology , Germination , Humans , Medicago sativa/microbiology , Raphanus/microbiology , Time Factors , Vegetables/standards
15.
J Food Prot ; 72(4): 860-5, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19435239

ABSTRACT

We investigated the heat resistance of a four-strain mixture of Escherichia coli O157:H7 in raw ground beef in both the absence and presence of white and green tea powders and an apple skin extract. Inoculated meat was cooked using the sous-vide technique, i.e., the meat was packaged in sterile bags and completely immersed in a circulating water bath at low temperature for a period of time. The bags were cooked for 1 h to an internal temperature of 55, 58, 60, or 62.5 degrees C, and then held from 240 min at 55 degrees C to 10 min at 62.5 degrees C. The surviving bacteria were enumerated by spiral plating onto tryptic soy agar overlaid with sorbitol-MacConkey agar. Inactivation kinetics of the pathogens deviated from first-order kinetics. D-values (time, in minutes, required for the bacteria to decrease by 90%) in the control beef ranged from 67.79 min at 55 degrees C to 2.01 min at 62.5 degrees C. D-values determined by a logistic model ranged from 36.22 (D1, the D-value of a major population of surviving cells) and 112.79 (D2, the D-value of a minor subpopulation) at 55 degrees C to 1.39 (D1) and 3.00 (D2) at 62.5 degrees C. A significant increase (P < 0.05) in the sensitivity of the bacteria to heat was observed with the addition of 3% added antimicrobials. D-value reductions of 62 to 74% were observed with apple powder and 18 to 58% with tea powders. Thermal death times from this study will assist the retail food industry to design cooking regimes that ensure the safety of beef contaminated with E. coli O157:H7.


Subject(s)
Camellia sinensis , Cooking/methods , Escherichia coli O157/physiology , Malus , Meat/microbiology , Plant Leaves/chemistry , Animals , Cattle , Food Microbiology , Fruit , Hot Temperature , Plant Extracts
16.
J Food Prot ; 72(11): 2407-12, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19903409

ABSTRACT

The behavior of high hydrostatic pressure-injured Escherichia coli O157:H7 cells (strain SEA13B88 and a strain from the June-July 1999 Oklahoma juice outbreak) in tomato juice (pH 4.1) and phosphate-buffered saline (PBS; pH 7.2) at final concentrations of 8.4 to 8.8 log CFU/ml, respectively, and treated at 400, 500, and 600 MPa for 40 min at 25 and 35 degrees C with storage at 5 and 23 degrees C for 1,800 min was investigated. Immediately after treatment and every 3 h for 24 h of storage, an aliquot (0.1 ml) was plated on Trypticase soy agar and sorbitol MacConkey agar to determine the percentage of injured population. Leakage of UV materials and possible recovery from injury were investigated. Pressure (600-MPa) treatment at 35 degrees C for 40 min caused a higher percentage of bacterial injury than for 10 min of treatment. A higher percentage of injured population was found among the Oklahoma strain cells than among strain SEA13B88 cells, and differences in viability loss for bacterial strains were determined. The viability loss determined in PBS was 4.8 log for SEA13B88 cells and 5.2 log for Oklahoma cells, while losses of 5.4 and 5.7 log were determined in tomato juice for SEA13B88 and Oklahoma cells, respectively. The leakage of intracellular materials of injured Oklahoma cells was higher than that observed for SEA13B88 cells, but injured Oklahoma cells recovered faster in PBS. However, injured and healthy populations for both strains were below detection in tomato juice stored at 5 degrees C for 1,440 min.


Subject(s)
Beverages/microbiology , Escherichia coli O157/growth & development , Food Handling/methods , Food Preservation/methods , Solanum lycopersicum , Colony Count, Microbial , Consumer Product Safety , Humans , Hydrogen-Ion Concentration , Hydrostatic Pressure , Temperature , Time Factors
17.
J Food Prot ; 71(4): 830-4, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18468042

ABSTRACT

The majority of the seed sprout-related outbreaks have been associated with Escherichia coli O157:H7 and Salmonella. Therefore, an effective method is needed to inactivate these organisms on the seeds before they are sprouted. This study was conducted to assess the effectiveness of various hot water treatments to inactivate E. coli O157:H7 and Salmonella populations on mung beans seeds intended for sprout production and to determine the effect of these treatments on seed germination after the seeds were dipped in chilled water for 30 s. Mung bean seed inoculated with four-strain cocktails of E. coli O157:H7 and Salmonella were soaked into hot water at 80 and 90 degrees C with shaking for various periods and then dipped in chilled water for 30 s. The treated seeds were then assessed for the efficacy of the treatment for reducing populations of the pathogens and the effects of the treatment on germination. After inoculation and air drying, 6.08 +/- 0.34 log CFU/g E. coli O157:H7 and 5.34 +/- 0.29 log CFU/g Salmonella were detected on the seeds. After hot water treatment at 90 degrees C for 90 s followed by dipping in chilled water for 30 s, no viable pathogens were found and no survivors were found in the enrichment medium and during the sprouting process. The germination yield of the seed was not affected significantly. Therefore, hot water treatment followed by dipping in chilled water for 30 s could be an effective seed decontamination method for mung bean seeds intended for sprout production.


Subject(s)
Escherichia coli O157/growth & development , Fabaceae/microbiology , Hot Temperature , Salmonella/growth & development , Seeds/microbiology , Colony Count, Microbial , Consumer Product Safety , Disease Outbreaks/prevention & control , Escherichia coli O157/drug effects , Food Contamination/prevention & control , Food Microbiology , Germination , Humans , Salmonella/drug effects , Seeds/physiology , Time Factors , Water
18.
Foodborne Pathog Dis ; 5(2): 175-82, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18377201

ABSTRACT

Eggs and egg-containing foods contaminated with bacterial human pathogens have been implicated in numerous foodborne outbreaks leading to costly recalls. Research was undertaken to investigate the use of high pressure-pulse treatment to inactivate Salmonella Enteritidis inoculated in liquid egg. Liquid egg was inoculated with Salmonella Enteritidis (8.0 log colony-forming units [CFU]/mL) and exposed to hydrostatic pressures (300-400 MPa) and pressure (350 MPa) pulsing at 25 degrees C, 40 degrees C, and 50 degrees C for up to 40 minutes to determine the maximum allowable pressure that can inactivate the Salmonella with minimal injury. Pressure treatments (350 and 400 MPa) at 25 degrees C for up to 40 minutes reduced the population of Salmonella Enteritidis by approximately 4.8 and 6.0 log(10) CFU/mL, respectively. High pressure (350 MPa) treatment at 50 degrees C and 2-minute pulses at four cycles for a total of 11.4 minutes, including the come-up and come-down times, led to a significant (p < 0.05) inactivation of Salmonella Enteritidis in liquid egg without causing coagulation. However coagulation occurred in the liquid egg at 400 MPa pressure treatment for 10 minutes at 50 degrees C. No Salmonella population was recovered in this liquid egg stored at 4 degrees C, 25 degrees C, and 37 degrees C for 24 hours suggesting that 350 MPa hydrostatic pressure and pulsing treatment is a better alternative for inactivation of Salmonella in liquid egg than continuous pressure treatment.


Subject(s)
Consumer Product Safety , Eggs/microbiology , Food Handling/methods , Hydrostatic Pressure , Salmonella enteritidis/growth & development , Colony Count, Microbial , Food Contamination/prevention & control , Humans , Temperature , Time Factors
19.
J Clin Invest ; 105(5): 663-71, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10712438

ABSTRACT

Complete ablation of nonmuscle myosin heavy chain II-B (NMHC-B) in mice resulted in cardiac and brain defects that were lethal during embryonic development or on the day of birth. In this paper, we report on the generation of mice with decreased amounts of NMHC-B. First, we generated B(DeltaI)/B(DeltaI) mice by replacing a neural-specific alternative exon with the PGK-Neo cassette. This resulted in decreased amounts of NMHC-B in all tissues, including a decrease of 88% in the heart and 65% in the brain compared with B(+)/B(+) tissues. B(DeltaI)/B(DeltaI) mice developed cardiac myocyte hypertrophy between 7 months and 11 months of age, at which time they reexpressed the cardiac beta-MHC. Serial sections of B(DeltaI)/B(DeltaI) brains showed abnormalities in neural cell migration and adhesion in the ventricular wall. Crossing B(DeltaI)/B(DeltaI) with B(+)/B(-) mice generated B(DeltaI)/B(-) mice, which showed a further decrease of approximately 55% in NMHC-B in the heart and brain compared with B(DeltaI)/B(DeltaI) mice. Five of 8 B(DeltaI)/B(-) mice were born with a membranous ventricular septal defect. Moreover, 5 of 5 B(DeltaI)/B(-) mice developed myocyte hypertrophy by 1 month; B(DeltaI)/B(-) mice also reexpressed the cardiac beta-MHC. More than 60% of B(DeltaI)/B(-) mice developed overt hydrocephalus and showed more severe defects in neural cell migration and adhesion than did B(DeltaI)/B(DeltaI) mice. These data on B(DeltaI)/B(DeltaI) and B(DeltaI)/B(-) mice demonstrate a gene dosage effect of the amount of NMHC-B on the severity and time of onset of the defects in the heart and brain.


Subject(s)
Brain/pathology , Gene Dosage , Myocardium/pathology , Myosin Heavy Chains/genetics , Animals , Cell Size , Heart Septal Defects/genetics , Histocytochemistry , Hydrocephalus/genetics , Kanamycin Kinase/genetics , Magnetic Resonance Imaging , Mice , Myosin Heavy Chains/deficiency , Phenotype , Phosphoglycerate Kinase/genetics
20.
J Food Prot ; 70(6): 1429-33, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17612073

ABSTRACT

We investigated the inhibition of Clostridium perfringens spore germination and outgrowth by two green tea extracts with low (green tea leaf powder [GTL]; 141 mg of total catechins per g of green tea extract) and high (green tea leaf extract [GTE]; 697 mg of total catechins per g of extract) catechin levels during abusive chilling of retail cooked ground beef, chicken, and pork. Green tea extracts were mixed into the thawed beef, chicken, and pork at concentrations of 0.5, 1.0, and 2.0% (wt/ wt), along with a heat-activated (75 degrees C for 20 min) three-strain spore cocktail to obtain a final concentration of approximately 3 log spores per g. Samples (5 g) of the ground beef, chicken, and pork were then vacuum packaged and cooked to 71 degrees C for 1 h in a temperature-controlled water bath. Thereafter, the products were cooled from 54.4 to 7.2 degrees C in 12, 15, 18, or 21 h, resulting in significant increases (P < 0.05) in the germination and outgrowth of C. perfringens populations in the ground beef, chicken, and pork control samples without GTL or GTE. Supplementation with 0.5 to 2% levels of GTL did not inhibit C. perfringens growth from spores. In contrast, the addition of 0.5 to 2% levels of GTE to beef, chicken, and pork resulted in a concentration-and time-dependent inhibition of C. perfringens growth from spores. At a 2% level of GTE, a significant (P < 0.05) inhibition of growth occurred at all chill rates for cooked ground beef, chicken, and pork. These results suggest that widely consumed catechins from green tea can reduce the potential risk of C. perfringens spore germination and outgrowth during abusive cooling from 54.4 to 7.2 degrees C in 12, 15, 18, or 21 h of cooling for ground beef, chicken, and pork.


Subject(s)
Clostridium perfringens/physiology , Food Handling/methods , Food Preservatives/pharmacology , Meat Products/microbiology , Plant Extracts/pharmacology , Tea , Animals , Cattle , Chickens , Clostridium perfringens/drug effects , Clostridium perfringens/growth & development , Colony Count, Microbial , Consumer Product Safety , Cooking , Dose-Response Relationship, Drug , Food Microbiology , Food Preservation/methods , Humans , Spores, Bacterial/growth & development , Swine , Tea/chemistry , Temperature , Time Factors
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