3,742 research outputs found
Stability of sorbitol dehydrogenase activity in bovine and equine sera
No full textSerum sorbitol dehydrogenase (SDH) activities in 10 cows and nine horses were measured using an automated clinical analyzer. The serum samples were divided into aliquots that were stored at room temperature (21 degrees C), refrigerated (0-5 degrees C), or frozen (-30 degrees C). The stability of the SDH activity was monitored at various intervals. SDH activity in bovine sera remained stable for at least 5 hours at room temperature, 24 hours refrigerated, and 72 hours frozen without any significant (p < 0.05) differences from the initial serum values. In equine sera, SDH activity remained stable for at least 5 hours at room temperature and 48 hours frozen. The activity of the refrigerated equine sera was stable for at least 5 hours but less than 24 hours. An evaluation of fresh bovine serum and heparinized plasma samples indicated that there was no significant difference (p < 0.05) between the two sampling methods and that either may be employed for automated measurement of SDH activity following the established protocol. Sample type comparison indicated that there was a small but statistically significant (p < 0.05) difference between the results obtained comparing fresh serum and heparinized plasma samples for the horse. A reference range for Holstein cows was established using sera from 71 clinically healthy cattle (mean -/+ 2 SD = 32 -/+ 26 U/L)
Effects of peroxides and preeclamptic sera on prostaglandin release by perfused human umbilical cord vein
No full textObjective
This study was performed to evaluate the prostaglandin secretion rates in human umbilical vein with preeclamptic sera and peroxide perfusion.
Study design
Isolated human umbilical cords(n=10) were perfused for 30-minute intervals with cord buffer, 15% normal pregnant sera and preeclamptic patient sera, 100 mol/L t-butyl hydroperoxide alone, and after perfusion with low-dose aspirin(5×10( )mol/L). Cord buffer gassed with 95% oxygen and 5% carbon dioxide and warmed to 37℃ was used for the perfusion buffer. Effluent flow rates were measured during each experimental treatment. Effluent samples were measured for 6-keto prostaglandin Flα and thromboxane B( ) by enzyme immunoassays.
Results
The concentrations of 6-keto prostaglandin F( )α in preeclamptic sera were significantly higher than those in normal pregnant sera.(989.3849 ± 1602.927 vs. 1.3116 ± 1.22085 ng/ml, mean ± SD, p<0.01). However, the concentrations of thromboxane B( ) were not different between normal pregnant sera and preeclamptic sera. The secretion rate of 6-keto-prostaglandin F( )α in human umbilical endothelial cells was not significantly different(p=0.77) between two groups. Comparing to normal pregnant sera, the secretion rate of thromboxane B( ) was significantly increased(p<0.01) after preeclamptic sera perfusion. The secretion rate of 6-keto-prostaglandin F( ) was significantly increased(p<0.01) following peroxide perfusion and that was significantly decreased by aspirin. The secretion rate of thromboxane B( ) was not significantly different between preeclamptic sera and peroxide alone or subsequent perfusion with aspirin.
Conclusions
(1) Preeclamptic sera stimulate thromboxane production rather than prostacyclin production by endothelial cells of human umbilical vein in vitro. (2) Peroxide stimulates the secretion of both prostacyclin and thromboxane, and low dose aspirin mitigates hydroperoxide-induced prostacyclin secretion. We confirmed that thromboxane secretion is stimulated by preeclamptic sera and the role of peroxide in prostaglandin secretion. We established the perfusion system using human umbilical vein through this study. This perfusion system may be useful to understand the pathophysiology of preeclampsia.Objective
This study was performed to evaluate the prostaglandin secretion rates in human umbilical vein with preeclamptic sera and peroxide perfusion.
Study design
Isolated human umbilical cords(n=10) were perfused for 30-minute intervals with cord buffer, 15% normal pregnant sera and preeclamptic patient sera, 100 mol/L t-butyl hydroperoxide alone, and after perfusion with low-dose aspirin(5×10( )mol/L). Cord buffer gassed with 95% oxygen and 5% carbon dioxide and warmed to 37℃ was used for the perfusion buffer. Effluent flow rates were measured during each experimental treatment. Effluent samples were measured for 6-keto prostaglandin Flα and thromboxane B( ) by enzyme immunoassays.
Results
The concentrations of 6-keto prostaglandin F( )α in preeclamptic sera were significantly higher than those in normal pregnant sera.(989.3849 ± 1602.927 vs. 1.3116 ± 1.22085 ng/ml, mean ± SD, p<0.01). However, the concentrations of thromboxane B( ) were not different between normal pregnant sera and preeclamptic sera. The secretion rate of 6-keto-prostaglandin F( )α in human umbilical endothelial cells was not significantly different(p=0.77) between two groups. Comparing to normal pregnant sera, the secretion rate of thromboxane B( ) was significantly increased(p<0.01) after preeclamptic sera perfusion. The secretion rate of 6-keto-prostaglandin F( ) was significantly increased(p<0.01) following peroxide perfusion and that was significantly decreased by aspirin. The secretion rate of thromboxane B( ) was not significantly different between preeclamptic sera and peroxide alone or subsequent perfusion with aspirin.
Conclusions
(1) Preeclamptic sera stimulate thromboxane production rather than prostacyclin production by endothelial cells of human umbilical vein in vitro. (2) Peroxide stimulates the secretion of both prostacyclin and thromboxane, and low dose aspirin mitigates hydroperoxide-induced prostacyclin secretion. We confirmed that thromboxane secretion is stimulated by preeclamptic sera and the role of peroxide in prostaglandin secretion. We established the perfusion system using human umbilical vein through this study. This perfusion system may be useful to understand the pathophysiology of preeclampsia
Polarographic Studies of Human Pregnant Sera
No full textThe important rôle of the sulfhydryl group in metabolic processes has long been recognized. It is suggested the possibility that toxemias of pregnancy may be related to the sulfhydryl contents in sera. Therefore, the sulfhydryl activity in sera was measured in normal and toxemic pregnant women. The author has carried out experiments according to Brdicka's polarographic method on sera from 43 pregnant women. Summary 1 The free sulfhydryl group in sera was estimated by a Brdicka's method. 2 Among normal non-pregnant women, the sulfhydryl content expressed as a wave height on polarogram were nearly uniform. 3 Sulfhydryl activities of pregnant women in the last trimester show values about 21.8% lower than non-pregnant women. 4 Sera obtained from pregnant women with marked edema showed a significant reduction in the sulfhydrylcontent and markedly in women with eclampsia. 5 The application of serial serum sulfhydryl determinations in pregnant women may be of value for study on toxemias of pregnancy
Pseudomonas syringae pv. actinidiae Type III Effectors Localized at Multiple Cellular Compartments Activate or Suppress Innate Immune Responses in Nicotiana benthamiana
No full textBacterial phytopathogen type III secreted (T3S) effectors have been strongly implicated in altering the interaction of pathogens with host plants. Therefore, it is useful to characterize the whole effector repertoire of a pathogen to understand the interplay of effectors in plants. Pseudomonas syringae pv. actinidiae is a causal agent of kiwifruit canker disease. In this study, we generated an Agrobacterium-mediated transient expression library of YFP-tagged T3S effectors from two strains of Psa, Psa-NZ V13 and Psa-NZ LV5, in order to gain insight into their mode of action in Nicotiana tabacum and N. benthamiana. Determining the subcellular localization of effectors gives an indication of the possible host targets of effectors. A confocal microscopy assay detecting YF-tagged Psa effectors revealed that the nucleus, cytoplasm and cell periphery are major targets of Psa effectors. Agrobacterium-mediated transient expression of multiple Psa effectors induced HR-like cell death (HCD) in Nicotiana spp., suggesting that multiple Psa effectors may be recognized by Nicotiana spp.. Virus-induced gene silencing (VIGS) of several known plant immune regulators, EDS1, NDR1, or SGT1 specified the requirement of SGT1 in HCD induced by several Psa effectors in N. benthamiana. In addition, the suppression activity of Psa effectors on HCD-inducing proteins and PTI was assessed. Psa effectors showed differential suppression activities on each HCD inducer or PTI. Taken together, our Psa effector repertoire analysis highlights the great diversity of T3S effector functions in planta.112Ysciescopu
Major histocompatibility complex in sheep (ola). I. Production of typing sera from parous dams of spanish merino sheep
No full textSera from 122 parous Merino sheep were screened for cytotoxic antibodies against sheep lymphocytes. Twenty antisera were selected. These sera were subjected to cluster analysis, and six specifities, designated M1—M6 were detected.Sueros procedentes de 122 ovejas paridas, de raza merina, han sido analizados en cuanto a su capacidad citotóxica contra antígenos linfocitarios ovinos. Se han encontrado 20 sueros positivos, los cuales han sido agrupados, por medio de un análisis de agrupamiento (clúster), en seis especificidades llamadas M1—M6
Evaluation of the enzyme-linked immunosorbent: assay (elisa) test for the detection of leptospiral antibodies in bovine sera, 1979
No full textThe Micro-Enzyme-Linked Immunosorbent Assay (ELISA) test was evaluated as a presumptive test for the diagnosis of bovine lepto�spirosis. Disposable flat bottom Micro-ELISA plates were utilized as antigen carriers and test vehicles. The antigen was prepared from a soluble alcohol extract of serovars, hardjo, Hardjoprajitno and ill ini, 3055 and stored at -70 C until ready for use in the test. Serology on each bovine serum sample was performed by using the Microscopic Agglutination Test (MA), the Indirect Hemagglutination Test (IHA), and the Enzyme-Linked Immunosorbent Assay (ELISA) Test. The comparison of the ELISA test with the MA and IHA was done with coded sera, randomized as to order of testing and stored at -20 C. A total of 142 different bovine serum samples was tested for the presence of 1eptospiral antibodies, using antigens serovar hardjo (a pathogen) and serovar ill ini (a saprophyte). Reproducibility was checked by duplicating 83 serum samples and triplicating 58 serum samples, resulting in a final total of 482 bovine serum samples being tested. All sera were tested by MA, IHA, and ELISA tests before being decoded for comparison of results. The total agreement of hardjo sera for both positive and negative sera was 48% among all 3 test procedures, whereas the total agreement of ill ini sera for both positive and negative sera was 92% among all 3 test procedures. The test was safer to perform since there was no need to use live antigens in the test; the test did not require pretreatment of sera; the test was read visually, and the test was a simple and rapid procedure. The sensitivity and specificity appear to have been low; however, in order to obtain further definitive results regarding the specificity, sensitivity, and the role of the ELISA test in the detection of 1eptospiral antibodies in bovine sera, other investigations will be needed in the future
A well-conserved Plasmodium falciparum var gene shows an unusual stage-specific transcript pattern
No full textThe var multicopy gene family encodes Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variant antigens, which, through their ability to adhere to a variety of host receptors, are thought to be important virulence factors. The predominant expression of a single cytoadherent PfEMP1 type on an infected red blood cell, and the switching between different PfEMP1 types to evade host protective antibody responses, are processes thought to be controlled at the transcriptional level. Contradictory data have been published on the timing of var gene transcription. Reverse transcription-polymerase chain reaction (RT-PCR) data suggested that transcription of the predominant var gene occurs in the later (pigmented trophozoite) stages, whereas Northern blot data indicated such transcripts only in early (ring) stages. We investigated this discrepancy by Northern blot, with probes covering a diverse var gene repertoire. We confirm that almost all var transcript types were detected only in ring stages. However, one type, the well-conserved varCSA transcript, was present constitutively in different laboratory parasites and does not appear to undergo antigenic variation. Although varCSA has been shown to encode a chondroitin sulphate A (CSA)-binding PfEMP1, we find that the presence of full-length varCSA transcripts does not correlate with the CSA-binding phenotype
A bacterial acetyltransferase triggers immunity in Arabidopsis thaliana independent of hypersensitive response
No full textType-III secreted effectors (T3Es) play critical roles during bacterial pathogenesis in plants. Plant recognition of certain T3Es can trigger defence, often accompanied by macroscopic cell death, termed the hypersensitive response (HR). Economically important species of kiwifruit are susceptible to Pseudomonas syringae pv. actinidiae (Psa), the causal agent of kiwifruit bacterial canker. Although Psa is non-pathogenic in Arabidopsis thaliana, we observed that a T3E, HopZ5 that is unique to a global outbreak clade of Psa, triggers HR and defence in Arabidopsis accession Ct-1. Ws-2 and Col-0 accessions are unable to produce an HR in response to Pseudomonas-delivered HopZ5. While Ws-2 is susceptible to virulent bacterial strain Pseudomonas syringae pv. tomato DC3000 carrying HopZ5, Col-0 is resistant despite the lack of an HR. We show that HopZ5, like other members of the YopJ superfamily of acetyltransferases that it belongs to, autoacetylates lysine residues. Through comparisons to other family members, we identified an acetyltransferase catalytic activity and demonstrate its requirement for triggering defence in Arabidopsis and Nicotiana species. Collectively, data herein indicate that HopZ5 is a plasma membrane-localized acetyltransferase with autoacetylation activity required for avirulence. ? 2017 The Author(s).115Ysciescopu
Convalescent sera, but not IgM-depleted sera, inhibited bacterial adhesion to intestinal epithelial cells.
No full textHT-29 cells (2 × 105 cells/ml) were cultured in a 24-well plate for 8 days until cells reached confluence. V. cholerae O1 Inaba (1 x 106 CFU/ml) was incubated with serially diluted convalescent sera (A) or antibody isotypes-depleted sera (B) for 1 h at 4°C and added to HT-29 cells. After additional 1 h incubation at room temperature with gentle shaking, HT-29 cells were washed with PBS followed by treatment with 0.2% TritonX 100. Adherent bacteria were cultured overnight on LB agar plates and counted. Values are mean ± standard deviation of triplicate samples.</p
Detection of antibodies to West Nile virus in equine sera using microsphere immunoassay
No full textOne hundred and ninety-one sera from horses that recently were exposed to West Nile virus (WNV) by either vaccination or natural infection or that were not vaccinated and remained free of infection were used to evaluate fluorescent microsphere immunoassays (MIAs) incorporating recombinant WNV envelope protein (rE) and recombinant nonstructural proteins (rNS1, rNS3, and rNS5) for detection of equine antibodies to WNV. The rE MIA had a diagnostic sensitivity and specificity, respectively, of 99.3% and 97.4% for detection of WNV antibodies in the serum of horses that were recently vaccinated or naturally infected with WNV, as compared to the plaque reduction neutralization test (PRNT). The positive rE MIA results were assumed to be WNV-specific because of the close agreement between this assay and the PRNT and the fact that unvaccinated control horses included in this study were confirmed to be free of exposure to the related St Louis encephalitis virus. The NS protein-based MIA were all less sensitive than either the rE MIA or PRNT (sensitivity 0-48.0), although the rNSI MIA distinguished horses vaccinated with the recombinant WNV vaccine from those that were immunized with the inactivated WNV vaccine (P < 0.0001) or naturally infected with WNV (P < 0.0001). The rE MIA would appear to provide a rapid, convenient, inexpensive, and accurate test for the screening of equine sera for the presence of antibodies to WNV.Accession Number: 16921881. Language: English. Language Code: eng. Date Revised: 20071114. Date Created: 20060822. Date Completed: 20061006. Update Code: 20111122. Publication Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't. Journal ID: 9011490. Publication Model: Print. Cited Medium: Print. NLM ISO Abbr: J. Vet. Diagn. Invest. Linking ISSN: 10406387. Subset: IM. Date of Electronic Publication: 20060701; ID: 16921881Source type: Electronic(1)http://search.ebscohost.com/login.aspx?direct=true&db=cmedm&AN=16921881&site=eds-liv
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