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1.
A gene encoding the 27.3 kilodalton cytolytic protein toxin in the mosquitocidal isolate (PG-14) ofBacillus thuringiensis subsp.morrisoni (BTM) was cloned and sequenced, and compared with the homologous gene inB. thuringiensis subsp.israelensis (BTI). The BTM gene was determined to be located on a 140 kb plasmid by use of a synthetic 20-base nucleotide probe derived from the sequence of the BTI gene. A 9.4-kbHind III plasmid fragment containing the BTM cytolytic protein gene was cloned into the plasmid vector pUC12, and subsequently subcloned and sequenced. Comparison of the nucleotide sequence of the BTM gene with that of the homologous BTI gene revealed only a single base difference; the base at position 310 in BTM is guanine, whereas in BTI it is cytosine. This single base change results in the occurrence of alanine rather than proline at amino acid residue 82 in BTM. Analysis of the secondary structure and hydropathic profile of the BTM protein indicates that alanine at this position increases both the propensity to form an -helical structure and the hydrophobicity in the vicinity of this residue. Thus, the BTM toxin is potentially more cytolytic than the homologous protein of BTI.  相似文献   

2.
Biodehalogenation of 10(-5) M concentrations of bromotrichloromethane (BTM) and 1,2-dibromo-3-chloropropane (DBCP) was studied in static cultures of Pseudomonas putida PpG-786. The experimental cultures were prepared by growing P. putida on camphor, which is known to induce the synthesis of high concentrations of cytochrome P-450 in this bacterium. Measurements of bromide ion release were found to be approximately consistent with the amounts of halocarbon degraded. Gas chromatography/elctron capture detection (GC/ECD) measurements of hydrocarbon degradation products as a function of incubation time showed the transitory appearance of chloroform and bromodichloromethane from BTM and the transitory appearance of lower boiling but unidentified products from DBCP. The degradation of BTM to trihalomethanes and the halide ion is consistent with the enzymatic reductive dehalogenation by cytochrome P-450 reported by others. The dependence of initial conversion rates on halocarbon concentration (0.1-2 ppm) and cell mass concentration (1-28 g cell/L) was determined by measuring the decline of parent halocarbon in stirred batch cell suspensions. The rate of DBCP conversion was up to 10-fold higher than the rate of BTM conversion. When the intracellular, enzyme-catalyzed conversion BTM is analyzed by the effectiveness factor of heterogeneous catalysis, the initial conversion rates measured suggest that intrinsic enzyme kinetics, rather than halocarbon permeation of the cell membrane or other diffusive processes, is rate limiting.  相似文献   

3.
Occult hepatitis C virus (HCV) infection (OCI) is described as the presence of viral genome in both hepatocytes and peripheral blood mononuclear cells (PBMCs) despite constant negative results on serum HCV RNA tests. Beta-thalassemia major (BTM) describes a group of inherited blood diseases. Patients with BTM require repeated blood transfusions, increasing the risk of exposure to infectious agents. We aimed to assess the prevalence of OCI in Iranian BTM patients and to identify the role of host factors in OCI positivity. A total of 181 BTM patients with HCV negative markers were selected. HCV RNA was tested in PBMCs using nested polymerase chain reaction assay. The positive samples were then genotyped via restriction fragment-length polymorphism (RFLP) and 5′-untranslated region sequencing. Six (3.3%) out of 181 BTM patients had viral HCV genomes in PBMC samples. Three (50.0%), two (33.3%), and one (16.7%) out of these six patients were infected with HCV-1b, HCV-1a, and HCV-3a, respectively. OCI positivity was significantly associated with the serum level of uric acid (P = 0.045) and ABO blood group (P = 0.032). Also, OCI patients had unfavorable IFNL3 rs12979860 TT, IFNL3 rs8099917 GG, IFNL3 rs12980275 GG, and IFNL4 ss469415590 ∆G/∆G genotypes. In conclusion, we indicated the low frequency of OCI in BTM patients. Nevertheless, more attention is warranted considering the importance of this infection. Also, further studies are necessary to determine the actual prevalence of OCI among BTM patients in Iran.  相似文献   

4.
The brown tail moth (BTM) Euproctis chrysorrhoea (Linnaeus 1758) (Lepidoptera: Erebidae) is a forest and ornamental pest in Europe and the United States. Its extreme polyphagy, and documented phenological shift associated with host use suggest the presence of distinct host-races. To test this hypothesis, we sampled BTM infesting different host species in several locations along its distribution, and used DNA sequence data (a total of 1,672 bp from cytochrome c oxidase subunit I, elongation factor 1-alpha, and wingless) to produce haplotype networks and reconstruct the phylogenetic relationships between individuals. Population genetic diversity indices pointed out a higher genetic diversity in Europe, particularly in the samples from southern Spain and southern England. Lower F ST values were found between geographically closer populations when compared to more distant ones, but analyses of molecular variance and Mantel tests failed to reveal geographically associated genetic differentiation. However, haplotype networks and phylogenetic reconstructions revealed a previously unknown genetic differentiation within the BTM, with one lineage circumscribed to southern Europe. Although BTM haplotypes did not cluster according to their host plant, host-associated haplotypes were observed within certain geographic regions. Hence, our data support the existence of host-races of BTM within southern Spain and southern England, where populations from different hosts occur in sympatry.  相似文献   

5.

Objectives

Thrombotic episodes occurred frequently in beta-thalassemia major (BTM) patients, leading to hypercoagulability of plasma. Protein Z (PZ) is a vitamin-K-dependent anti-coagulation factor that plays a role in the human homeostatic process. The objective of the current study is to investigate the distribution pattern of PZ plasma concentrations between BTM patients and the normal population in Ahvaz city, the center of Khuzestan province, southwest of Iran.

Material and Methods

Forty confirmed BTM patients and 40 healthy volunteers were evaluated for complete blood count (CBC) indices and PZ plasma levels. CBC samples were measured using an automated cell counter, and PZ was assayed with an immunoassay method. Statistical analysis was conducted using SPSS software. The ROC curve and binary logistic regression estimated the sensitivity, specificity, and Odd’s ratio for PZ measurement.

Results

The mean±SD of the PZ plasma level in normal individuals was 1.68±0.63 μg/mL, and in BTM patients, it was 1.10±0.52 μg/mL. This shows a significant reduction of PZ in BTM patients statistically (CI = 0.99; p<0.001). Further, the mean±SD of the PZ plasma levels in BTM patients who received washed red blood cells was not significantly different from that of patients undergoing packed red blood cell therapy (CI = 0.95; p = 0.320). The area under the curve (AUC) for PZ was 0.759 (p = 0.00). The cut-off value = 1.4 μg/mL of the PZ plasma level had at least 70% sensitivity and specificity in BTM patients.

Discussion

Several epidemiologic studies have shown thromboembolism episodes in BTM patients. In the current study, PZ was reduced significantly in BTMs.

Conclusion

We noticed that BTMs have lower plasma PZ concentration might be predisposed to BTM.
  相似文献   

6.
Different tests performed on bulk tank milk samples (BTM) are available to determine the C. burnetii status of herds. However, these tests, which are based on the detection of either antibodies directed against C. burnetii (ELISA) or bacterial DNA (PCR), have limitations. A currently disease-free herd infected in the past may continue to test positive with ELISA due to the persistence of antibodies in animals that were infected and that subsequently cleared the infection. Infectious herds can also be misclassified using PCR because of the absence of bacteria in the BTM when the test is performed. Recently, PCR has been used for bacterial DNA detection in the farm environment, which constitutes the main reservoir of C. burnetii. The objectives of this study were to assess and compare the sensitivities and specificities of one commonly used PCR test in BTM (PCR BTM) and of a PCR applied to environmental samples (PCR DUST) in dairy cattle farms. BTM and dust samples were collected (using environmental swabs) in 95 herds. The evaluation of the performance of the 2 tests was conducted using latent class models accounting for within herd disease dynamics. Parameter estimation was carried out using MCMC, within a Bayesian framework. Two types of priors were used for the specificity of PCR DUST. A model with a uniform prior on 0–1 fitted the data better than a model with a uniform prior on 0.95–1. With the best model PCR DUST had a lower sensitivity than PCR BTM (0.75 versus 0.83) and a specificity of 0.72. The moderately low value for the specificity of PCR DUST suggests that the presence of bacteria on farm is not always associated with persistent infections and shedding of bacteria in milk.  相似文献   

7.
Bulk tank milk (BTM) samples were collected from 81 sheep flocks in the Basque Country, Spain, in 2015 and were analysed for antibodies against Coxiella burnetii by ELISA and for C. burnetii DNA by real-time PCR. Thirty-two percent of the flocks had BTM antibodies against C. burnetii. Presence of C. burnetii DNA in BTM was detected in 23% of the flocks, suggesting recent C. burnetii infections. Retrospective data of BTM samples obtained from 154 sheep flocks investigated in 2005 in the same geographic area were compiled to assess temporal changes in C. burnetii infection. The overall percentage of infected sheep flocks did not significantly change after the 10-year period. Among the 46 flocks sampled in both periods, 11 flocks that were negative in 2005 were positive in 2015, 18 maintained their initial status (positive or negative), and 17 positive flocks were negative in 2015. These findings indicate that C. burnetii infection is a dynamic process in dairy sheep in northern Spain. Single nucleotide polymorphism (SNP) genotyping of positive samples identified three genotypes, SNP1 being the most prevalent in 2015 and SNP8 in 2005; SNP4 was only detected once in 2005. These results suggest possible changes in the pattern of genotype infection over time.  相似文献   

8.
Serum procollagen type I N-propeptide (PINP) is designated the reference marker of bone formation in osteoporosis; the reference marker for resorption is C-terminal telopeptide of type I collagen (CTX). PINP has very low circadian and biological variation, is not affected by food intake, and is very stable in serum after venepuncture. The two automated commercial assays for PINP provide similar results in subjects with normal renal function, allowing reference intervals to be used interchangeably. Bone turnover markers (BTM) are currently not recommended for fracture risk assessment and therefore not included in fracture risk calculators. In the management of osteoporosis, the main utility of BTM including PINP is for monitoring therapy, both antiresorptive as well as anabolic agents; monitoring is thought to help improve adherence. PINP as well as CTX may also be used in assessing offset of drug action following a pause in bisphosphonate therapy, to help decide when to re-instate therapy, or following cessation of denosumab therapy to assess efficacy of follow-on bisphosphonate therapy. PINP may also be used in the diagnosis of Paget’s disease of bone as well as in monitoring response to therapy and for recurrence. Although BTM other than bone alkaline phosphatase are currently not recommended for use in metabolic bone disease of chronic kidney disease, PINP measured by assays specific to the intact molecule has potential in this condition. Further studies are needed to examine this area, as well as in malignant bone disease.  相似文献   

9.
10.
The potential association between hygienic conditions in the environment of lactating cows and the presence of gliotoxinogenic Aspergillus fumigatus strains was studied. Milk samples (individual cow’s milk [ICM], bulk tank milk [BTM]) from 44 dairy farms were sampled. In ICM samples, eight different species of Aspergillus were identified. A. flavus and A. fumigatus were predominant, with 37.8 % and 26.1 % relative densities, respectively. A. fumigatus strains were isolated from 61.4 % of the BTM samples, and 34 % of these strains were able to produce gliotoxin. Principal component analysis was used to associate the presence of A. fumigatus with some hygienic and sanitary practices. A significant and positive correlation was observed between dry cow therapy and forestripping. The presence of A. fumigatus gliotoxin producers in milk was associated with high somatic cells count (SCC) samples. Good hygienic and sanitary practices were associated with absence of A. fumigatus and relatively low SCCs of <250,000 cells/ml. In general, a high percentage of dairy farms were positive for A. fumigatus in BTM samples. This is the first work that indicates the positive effects of adequate hygienic and sanitary practices in dairy herds on the control of A. fumigatus and related species. By reducing the frequency of Aspergillus spp. in the dairy environment, the risk of farm handlers’ exposure and the risk of intramammary fungal infections would also be reduced.  相似文献   

11.
Hepcidin is a key iron-regulatory hormone, the production of which is controlled by iron stores, inflammation, hypoxia and erythropoiesis. The regulation of iron by hepcidin is of clinical importance in thalassemia patients in which anemia occurs along with iron overload. The present study aimed to evaluate the correlation between serum hepcidin and ferritin levels in thalassemia patients. This cross-sectional study investigated 64 patients with thalassemia; 16 β-thalassemia major (BTM), 31 β-thalassemia/hemoglobin (Hb) E (BE), and 17 Hb H + AE Bart’s disease (Hb H + AE Bart’s). The levels of serum hepcidin and ferritin, and Hb of the three groups were measured. The median values of serum ferritin and Hb were significantly different among the three groups, whereas serum hepcidin values were not observed to be significantly different. The correlation of the serum hepcidin and ferritin levels was not statistically significant in any of the three groups of thalassemia patients with BTM, BE, or Hb H + AE Bart’s (r = −0.141, 0.065 and −0.016, respectively). In conclusion, no statistically significant correlations were observed between serum hepcidin with any variables including serum ferritin, Hb, age, labile plasma iron (LPI), and number of blood transfusion units among the three groups of thalassemia patients. Likely, the regulation of hepcidin in thalassemia patients is affected more by erythropoietic activity than iron storage.  相似文献   

12.
This study was designed to monitor the presence of Mycoplasma agalactiae and Mycoplasma mycoides subsp. capri (Mmc) in 66 dairy goat herds of a genetic improvement programme in a region of Spain where contagious agalactia is endemic. Over a whole lactation period, 300 bulk tank milk and 381 milk samples from goats with clinical mastitis were subjected to polymerase chain reaction (PCR) to detect the two mycoplasma species. The presence of mycoplasmas (either species or both) was detected in 66.7% of the herds and M. agalactiae was identified in 95.45% of these positives herds. In a given infected herd, mycoplasmas were not continuously detected over the whole study period. Our findings indicate that in an endemic area, M. agalactiae and Mmc can be monitored through PCR analysis of mastitic milk and bulk tank milk (BTM) samples. Over a lactation period we recommend testing multiple BTM samples on a herd. No relationship was observed between the use of inactivated mycoplasma vaccines and the PCR detection of both mycoplasmas.  相似文献   

13.

Introduction

The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-α) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with ankylosing spondylitis (AS).

Methods

This is a prospective cohort study of 111 consecutive AS outpatients who started TNF-α blocking therapy. Clinical assessments and BTM were assessed at baseline, three and six months, as well as at one, two, and three years. Z-scores of BTM were calculated to correct for age and gender. Bone mineral density (BMD) was assessed yearly.

Results

After three years, 72 patients (65%) were still using their first TNF-α blocking agent. In these patients, TNF-α blocking therapy resulted in significantly increased bone-specific alkaline phosphatase, a marker of bone formation; decreased serum collagen-telopeptide (sCTX), a marker of bone resorption; and increased lumbar spine and hip BMD compared to baseline. Baseline to three months decrease in sCTX Z-score (HR: 0.394, 95% CI: 0.263 to 0.591), AS disease activity score (ASDAS; HR: 0.488, 95% CI: 0.317 to 0.752), and physician''s global disease activity (HR: 0.739, 95% CI: 0.600 to 0.909) were independent inversely related predictors of time to treatment discontinuation because of inefficacy or intolerance. Early decrease in sCTX Z-score correlated significantly with good long-term response regarding disease activity, physical function and quality of life.

Conclusions

Three years of TNF-α blocking therapy results in a bone turnover balance that favors bone formation, especially mineralization, in combination with continuous improvement of lumbar spine BMD. Early change in sCTX can serve as an objective measure in the evaluation of TNF-α blocking therapy in AS, in addition to the currently used more subjective measures.  相似文献   

14.
以拟水狼蛛为研究对象,采用原子吸收光谱法测定了不同生境汞在土壤和蜘蛛体内的含量,研究了不同生境汞对拟水狼蛛抗氧化酶的影响.结果 表明:4个采集样点(S1、S2、S3和S4)拟水狼蛛体内重金属汞的含量差异显著(P<0.05).在重金属胁迫下,重金属汞含量高(S1、S2和S3)的拟水狼蛛体内GSH含量显著高于对照组(S4),是对照组的2.4~3.8倍.GSH含量与重金属汞含量显著正相关(r2=0.9624,P<0.01).对于GST、CAT和SOD,重金属汞含量高则酶活性低,GST、CAT和SOD酶活性与重金属汞含量显著负相关.因此检测拟水狼蛛体内的酶活性变化即可知环境中重金属汞的污染程度,提示拟水狼蛛可以作为重金属污染的重要监测指示生物.  相似文献   

15.
The parasporal body of the mosquitocidal isolate (PG-14) of Bacillus thuringiensis subsp. morrisoni (BTM) contains five major proteins with molecular masses of, respectively, 27.3, 65, 128, 135, and 144 kDa. Proteins corresponding in mass to the first four of these also occur in the mosquitocidal strain, B. thuringiensis subsp. israelensis (BTI), and it is thought therefore that the mosquitocidal activity of both strains is due to these four proteins. In other studies it has been shown that each of these proteins exhibits from moderate to high toxicity to mosquitoes, though the specific toxicity of the 144 kDa protein in PG-14 to mosquitoes remains unknown. In the present study, two parasporal body mutants (M146 and M242) of PG-14 were developed growing the wild-type strain at 42 degrees C. The parasporal body of M146 contained less of the 65-kDa protein and was less toxic (LC50 = 108 ng/ml) to mosquitoes than the wild-type strain (LC50 = 8.3 ng/ml). The parasporal body of M242 consisted of a bipyramidal crystal composed of a 144-kDa protein that was not toxic to the mosquito, Aedes aegypti, but exhibited substantial toxicity (LC50 = 2.5 micrograms/ml) to the lepidopteran. Trichoplusia ni. Because the parasporal bodies of BTI and BTM PG-14 are similar in mosquitocidal toxicity on a weight basis, the latter results suggest the 144-kDa protein, though not mosquitocidal alone, can contribute to mosquitocidal, activity when in the presence of other mosquitocidal proteins.  相似文献   

16.
We have investigated different dialysis strategies for the refolding of recombinant streptavidin, and present a novel dialysis setup featuring gradual dilution dialysis and continuous protein feeding into a dialysis sack. A denaturing dialysis buffer is exchanged gradually by dilution with refolding buffer and it is demonstrated that the refolding yield can be increased from 45 to 75% by lowering the dilution rate. In addition, continuous feeding of protein to the dialysis sack increases the yield by 5 to 10%. The principle of gradual dilution dialysis is amenable to stringent regulation and we suggest it to be applied for other insoluble protein targets.  相似文献   

17.
张征田  夏敏  彭宇  杜瑞卿 《昆虫学报》2009,52(9):994-999
为了探明重金属含量对拟水狼蛛Pirata subpiraticus生物学特性的影响, 本研究于2008年7月在河南南阳地区5种不同生境下, 共采集50份土壤样本和150头拟水狼蛛样本, 采用原子吸收光谱法测定了5种不同生境下雌拟水狼蛛体内重金属含量, 并测定了雌蛛头胸甲宽、体重、卵袋重量、卵数目和卵体积等生物学指标。结果表明:不同样点拟水狼蛛重金属含量与土壤重金属含量显著正相关, 4个重金属污染区与宝天曼自然保护区(Baotianman, BTM)拟水狼蛛体内Cd、Cu和Zn的含量差异极显著(P<0.001), 桐柏铜矿(Tongbai Tongkuang, TBTK)和南阳油田(Nanyang Youtian, NYYT) 的Pb含量与BTM的差异极显著(P<0.001), 主成分分析表明Cd、Cu和Zn是反应重金属污染的主要指标。在重金属胁迫下, 4个重金属污染区与保护区的拟水狼蛛头胸甲宽、雌体重量、卵袋重量、卵数目和卵体积差异均达到极显著(P<0.001)或显著水平(P<0.05), 主成分分析表明背胸甲宽、卵袋重量和卵体积是重要生物学指标。 拟水狼蛛的背胸甲宽、卵袋重量和卵的体积与重金属含量显著相关, 重金属含量高的地方拟水狼蛛背胸甲宽较小, 雌性体重、卵袋重量和卵数目较小, 卵的体积大, 因此说明拟水狼蛛处在逆环境中时, 动物为保持总的繁殖力不变的前提下, 后代个体的大小与数目间满足某种平衡, 即达到协同进化的目的, 拟水狼蛛可以作为重金属污染的监测指示生物。  相似文献   

18.
We examined the impact of intracellular dialysis on fluorescence detection of neuronal intracellular Zn2+ accumulation. Comparison between two dialysis conditions (standard; 20 min, brief; 2 min) by standard whole‐cell clamp revealed a high vulnerability of intracellular Zn2+ buffers to intracellular dialysis. Thus, low concentrations of zinc‐pyrithione generated robust responses in neurons with standard dialysis, but signals were smaller in neurons with short dialysis. Release from oxidation‐sensitive Zn2+ pools was reduced by standard dialysis, when compared with responses in neurons with brief dialysis. The dialysis effects were partly reversed by inclusion of recombinant metallothionein‐3 in the dialysis solution. These findings suggested that extensive dialysis could be exploited for selective detection of transmembrane Zn2+ influx. Different dialysis conditions were then used to probe responses to synaptic stimulation. Under standard dialysis conditions, synaptic stimuli generated significant FluoZin‐3 signals in wild‐type (WT) preparations, but responses were almost absent in preparations lacking vesicular Zn2+ (ZnT3‐KO). In contrast, under brief dialysis conditions, intracellular Zn2+ transients were very similar in WT and ZnT3‐KO preparations. This suggests that both intracellular release and transmembrane flux can contribute to intracellular Zn2+ accumulation after synaptic stimulation. These results demonstrate significant confounds and potential use of intracellular dialysis to investigate intracellular Zn2+ accumulation mechanisms.  相似文献   

19.
The uptake of copper and zinc by patients undergoing regular haemodialysis has been assessed by measuring the dialysis fluid for copper and zinc concentration, and the blood entering and leaving the dialysis coil for red cell copper, plasma free copper, and plasma zinc levels during priming of the coil and subsequent haemodialysis, and by in-vitro studies.Red cells avidly removed copper from dialysis fluid when mixed with saline during priming, but did not take up copper during the haemodialysis. At both these stages plasma actively took up both copper and zinc from dialysis fluid, even against a concentration gradient, so that loss of these metals from plasma to dialysis fluid did not occur.In the dialysis systems investigated the sources of the copper in the dialysis fluid were the copper plumbing of the tap-water and the dialysis coil, and the major source of zinc was the zinc oxide of the adhesive plaster around the dialysis coil.  相似文献   

20.

Objective:

We investigated acute bone turnover marker (BTM) responses to high-intensity resistance exercise with and without whole-body vibration (WBV) in young men (n=10).

Methods:

In this randomized crossover study, subjects performed 2 protocols separated by 2-week wash out periods: 1) resistance exercise only (RE) (3 sets 10 repetitions 80% 1RM for 9 exercises); and 2) WBV + RE (side-alternating vibration platform 5 intermittent, 1-minute bouts 20 Hz, 3.38 mm peak-to-peak displacement followed by RE). Fasting morning blood draws were taken before RE or WBV (PRE), immediately post RE (IP), and 30 minutes post RE (30P). WBV + RE also had a blood draw after the WBV exposure (POST WBV). Blood samples were analyzed for lactate, hematocrit, bone-specific alkaline phosphatase (Bone ALP, U/L), C-terminal telopeptide of type I collagen (CTX-I, ng/mL) and tartrate-resistant acid phosphatase 5b (TRAP5b, U/L).

Results:

Lactate, hematocrit, and Bone ALP significantly increased (p<0.05) IP for both protocols. Bone resorption markers did not change during RE only. CTX-I significantly decreased POST WBV. TRAP5b increased POST WBV, then significantly decreased at 30P.

Conclusions:

Generally, BTM changes to RE only were not significant when adjusted for hemoconcentration. The WBV stimulus altered bone resorption marker but not bone formation marker responses.  相似文献   

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