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2.
BackgroundThe human Torque Teno virus (TTV) causes persistent viremia in most immunocompetent individuals. Elevated TTV levels are observed after solid organ transplantation and are related to the extent of immunosuppression especially during the phase of maintenance immunosuppression. However, the extent to which the TTV increase in the early phase post-transplantation is associated with the patient’s immunosuppressive state is unclear. ObjectivesIn this study, we assessed the TTV increase dynamics in detail during the first three months after lung transplantation under a defined immunosuppressive regimen and in relation to the pre-transplant TTV level. Study DesignForty-six lung transplant recipients (LTRs) were included in this prospective longitudinal study. All received alemtuzumab induction combined with tacrolimus and corticosteroids immunosuppressive therapy. Plasma TTV DNA was monitored before transplantation and regularly within the first three months post-transplantation (n = 320 samples; mean sampling interval: 12.2 days). ResultsIn 43/46 LTRs (93%), TTV DNA was detectable before transplantation (median 4.4 log 10 copies/mL; range: 2.0–6.4). All 46 LTRs showed a TTV increase post-transplantation, which followed a sigmoidal-shaped curve before the median peak level of 9.4 log 10 copies/mL (range: 7.6–10.7) was reached at a median of day 67 (range: 41–92). The individual TTV DNA doubling times (range: 1.4–20.1 days) significantly correlated with the pre-transplant TTV levels calculated over 30 or 60 days post-transplantation (r = 0.61, 0.54, respectively; both P < 0.001), but did not correlate with the mean tacrolimus blood levels. Pre-transplant TTV levels were not associated with time and level of the patients’ post-transplant TTV peak load. ConclusionThe TTV level may be used to mirror the state of immunosuppression only after the patients’ initial peak TTV level is reached. 相似文献
4.
Polymorphisms in IL6, ACE and ATR genes are associated with obesity. Torque Teno virus (TTV) seems to be able to interfere with production of some proinflammatory cytokines associated with obesity and related phenotypes. The aim of this study was to test the potential association between obesity, TTV infection and the IL6 G-174C ( rs1800795), ACE I/D ( rs4646994), AT1R A1166C ( rs5186) polymorphisms. The polymorphisms and the presence of TTV were detected in blood samples from 150 obese and 150 normal-weight, healthy subjects using PCR based methods. IL6-174 CC genotype was more frequent in all obese patients (P=0.02) and in patients without TTV infections (P=0.03) than in controls. Obese women had more frequent TTV infections compared with normal-weight women (P=0.046). Obese subjects, regardless of gender (women P=0.03, men P=0.04), and healthy normal-weight men (P<0.01) carriers of AT1R C allele had higher triglycerides levels compared with non-carriers. The frequency of TTV in the control group (70.67%) was similar to data reported in other populations. The present study indicated that IL6-174 CC genotype and TTV infections in women could be associated with the common form of obesity. 相似文献
5.
利用PCR方法从输血传播性病毒 ( transfusiontransmittedvirus,TTV)阳性标本中获得不同长度且重叠覆盖TTV基因组的DNA片段。将PCR扩增片段克隆到pT Adv载体中 ,筛选获得阳性克隆。DNA序列测定结果表明所克隆的片段为TTV基因组序列。利用DNA片段中特有的限制性内切酶位点将TTV的DNA片段首尾相连 ,得到近全长的基因组克隆 ,命名为TTV0 2 1。对TTV0 2 1的核酸序列进行分析 ,TTV0 2 1长 3472nt,存在 2个阅读框架ORF1和ORF2 ,分别编码 785和 1 46个氨基酸。将TTV0 2 1与其它已知的TTV基因组全序列进行了同源性比较 ,并进行进化分析。结果表明 ,TTV0 2 1序列与TTV分离株CHN2、BDH1的遗传距离较近 ,而与其它分离株相对较远。 相似文献
6.
The efficacy of ground Ricinus communis fruit, with and without Bacillus species, was tested on suppression of Meloidogyne incognita, growth of tomato, soil electrical conductivity (EC) and soil pH. At harvest, 85 days after applying Ricinus organic amendment, Ricinus and initial population nematode density (P i), accounted for 64–74% of the total treatment variation (TTV) in final population nematode density (P f) and 53–89% of the TTV in dry shoot weight. Ricinus, P i and electrical conductivity accounted for 49–69% of the TTV in fresh fruit weight, whereas Ricinus, P i and Bacillus accounted for 65–82% of the TTV in plant height. Because Bacillus× Ricinus interaction was not significant (P > 0.05) for any variable measured, the efficacy of Ricinus fruit meal was independent of microbial activities. 相似文献
7.
Many aspects of the life cycle of torquetenoviruses (TTVs) are essentially unexplored. In particular, it is still a matter of speculation which cell type(s) replicates the viruses and maintains the generally high viral loads found in the blood of infected hosts. In this study, we sequentially measured the TTV loads in the plasma of four TTV-positive leukemia patients who were strongly myelosuppressed and then transplanted with haploidentical hematopoietic stem cells. The findings provide clear quantitative evidence for an extremely important role of hematopoietic cells in the maintenance of TTV viremia.Torquetenoviruses (TTVs) are small naked DNA viruses distinguished by a circular single-stranded DNA genome of only 3.8 kb, classified within the newly established family Anelloviridae ( 7). TTVs have been found in several animal species but do not appear capable of interspecies transmission. Due to their extensive genetic heterogeneity, human TTVs have been operatively subdivided into 5 genogroups and more than 40 genotypes ( 4). A remarkable feature of these TTVs is their presence in the plasma of nearly all people, regardless of geographical origin, age, and health status, raising many questions about their life cycle and possible pathological implications ( 2, 5). Plasma loads of TTVs vary extensively in both healthy and diseased individuals, usually ranging between 10 3 and 10 7 DNA copies per ml of plasma. However, some patients, including those with selected inflammatory or neoplastic disorders, transplant recipients, and human immunodeficiency virus-infected individuals, have a tendency to carry especially high burdens of TTVs ( 1, 6, 13, 22- 24).By studying the dynamics of TTV viremia in individuals treated with alpha interferon for hepatitis C, the kinetics of virus replication was found to be quite high, with numbers of virions released into plasma and cleared from it daily on the same order of magnitude as other chronic plasma viremia-inducing viruses, such as the hepatitis B, hepatitis C, and human immunodeficiency viruses ( 16). Yet, due to considerable difficulties encountered in propagating TTVs in culture and in distinguishing the virions passively adsorbed onto the cells from the ones replicating inside cells, the tissue or tissues where these large numbers of TTV virions originate have yet to be established. Given that the amino acid compositions of the capsid protein believed to mediate viral adsorption to cells are quite diverse in different TTVs ( 2, 3, 9), it is also possible that permissive cells vary depending on the TTV considered. Relevant studies are limited. Short-term cultures of phytohemagglutinin-stimulated peripheral lymphocytes, but not resting lymphocytes were found to permit a measurable level of TTV replication ( 15, 18), indicative of at least a moderate degree of lymphotropism. On the other hand, the detection of replicative forms of TTV DNA in several tissues, including bone marrow, peripheral blood mononuclear cells, and liver, has suggested that TTVs might be polytropic in nature ( 2, 21).In 1999, Kanda et al. ( 10), researching TTV plasma of bone marrow transplant recipients with a qualitative PCR, noticed that 5 out of 6 previously positive patients tested negative in a sampling collected during the myelosuppressed period and became positive again after graft reconstitution, leading them to suggest that TTV might replicate mainly in hematopoietic cells. In the present study, we further developed this observation by measuring the TTV load in sequential plasma samples obtained from four TTV-positive leukemia patients undergoing hematopoietic stem cell transplantation. This procedure basically consists of a myeloablative conditioning regimen (chemotherapy plus radiotherapy) followed by reinfusion of a positively selected CD34 + stem cell population. The findings are of interest because, in addition to confirming the decrease of TTV load observed by Kanda et al., they shed light on the kinetics of the effect, thus providing a better insight onto the role of hematopoietic cells in the maintenance of TTV viremia and on the life cycle of TTV in general.Table summarizes the main characteristics of the patients selected for the study. They were treated with 10 Gy total-body irradiation (TBI) on day 0 and received 5 mg/kg/day thiotepa on days 2 and 3, 40 mg/m 2/day fludarabine on days 3 to 7, and 1.2 mg/kg/day antithymocyte globulin on days 4 to 8, and then, on day 10, they received the indicated numbers of positively selected CD34 + hematopoietic stem cells from HLA-haploidentical donors. Peripheral blood samples were collected for TTV studies immediately before TBI and at selected times for the next 30 days, and plasma was stored in aliquots at −80°C until DNA extraction. The assay used for TTV quantification was a previously described highly sensitive TaqMan real-time PCR having the potential to detect and quantitate all hitherto recognized genetic forms of the virus ( 15, 16). All samples from each patient were assayed in a single run and in triplicate, and at least two independent DNA extractions for each sample were examined. The DNA extracts obtained at time zero were also typed with a previously described panel of five distinct PCR assays ( 12), each specific for one of the genogroups into which TTVs are subdivided. At the start of the study, the patients had viral loads ranging from 4.7 to 6.8 log copies per ml of plasma and harbored between 1 and 3 TTV genogroups (Table ). In particular, all carried genogroup 1, which is highly represented in our area ( 12), and two carried one or two further genogroups. Consistent with previous findings ( 12), the patient who harbored three genogroups was the one with the highest viral load. As shown by Fig. , in all four patients, TBI was followed by a steady decline of TTV viremia that continued for at least 22 days and progressively brought the virus to levels very close to the detection limit of the detection/quantitation method used, corresponding to values ranging between 0.003 (patient 3) and 0.00009 (patient 1) of the loads present prior to TBI. However, in no instance did the viral loads go below the limit of sensitivity of the assay (2 × 10 2 TTV DNA copies per ml of plasma). Although the size of the study does not permit firm conclusions on this aspect, it is noteworthy that the extent of decline was unrelated to the type and number of infecting TTV genogroup(s) originally present in the patients. Open in a separate windowPlasma TTV loads and WBC counts in the peripheral blood of the 4 patients (Pt. 1 to 4) enrolled in the study. The arrow indicates the day the patients were infused with CD34 + hematopoietic stem cells from HLA-haploidentical donors. The horizontal broken line represents the lower limit of sensitivity of the TTV detection method used. TABLE 1.Relevant parameters of the patients enrolled Patient | Age in yr (sex) | Clinical diagnosisa | No. of CD34 cells grafted (106 cells/kg) | Survival (days) | TTV in plasma
|
---|
Pre-TBI
| Post-TBI
|
---|
No. of copies/ml | Genogroup(s) | No. of copies/mlb | Genogroup(s) |
---|
1 | 54 (male) | T-ALL | 23.60 | 30 | 6.8 | 1, 3, 5 | NDc | ND | 2 | 47 (female) | ALL | 9.41 | 174 | 4.7 | 1, 4 | 5.4 (day 80) | 1, 3, 4, 5 | 3 | 41 (female) | B-ALL | 11.70 | 111 | 5.3 | 1 | 4.2 (day 30) | 3 | 4 | 58 (female) | AML | 5.90 | 267 | 5.0 | 1 | 7.0 (day 110) | 1, 3, 4, 5 | Open in a separate windowaT-ALL, T-cell acute lymphoblastic leukemia; B-ALL, B-cell acute lymphoblastic leukemia; AML, acute myeloid leukemia. bThe day post-TBI when TTV loads and genogroups were determined is shown in parentheses. cND, not determined.The viral loads observed during the phase of maximum decline (days 0 to 12) were then exploited to investigate the dynamics of TTV infection in the patients by using the mathematical model originally developed by Neumann et al. ( 20). The results of this analysis are shown in Table . The mean clearance rate of circulating TTVs was 3.8 days −1. The half-life of plasma TTVs ranged between 3.6 and 4.8 h, with a mean of 4.3 h, which is a little shorter than previously calculated in patients treated with alpha interferon ( 16), possibly due to the fact that TBI may have led to a more complete block of viral replication. Overall, however, these values coupled with the calculated numbers of virions produced per day (Table ) are a further demonstration that TTV infection is highly dynamic. TABLE 2.TTV dynamics in the patients enrolled Patient | Viral parameter
|
---|
Clearance rate (c [days−1]) | Virion half-life (days)a | Minimal input and clearance of plasma virions/dayb |
---|
1 | 3.8 | 0.18 | 7.8 × 1010 | 2 | 4.5 | 0.15 | 6.7 × 109 | 3 | 3.7 | 0.19 | 2.1 × 109 | 4 | 3.5 | 0.20 | 9.6 × 108 | Mean ± SE | 3.8 ± 0.2 | 0.18 ± 0.01 | 2.0 × 1010 ± 1.0 × 1010 | Open in a separate windowaCalculated by the equation ln (2)/ c. bDaily production of plasma virions was calculated from c multiplied by the pre-TBI viremia load value and by extracellular body fluid volume , which was arbitrarily set at 3.0 × 10 3 ml.One patient died of multiorgan failure a few h after the 30-day sampling point without noticeable changes in either TTV viremia and white blood cell (WBC) counts. The other patients, starting from day 26, showed a generally moderate but consistent increase of TTV viremia, so that by the end of the 30-day observation period their viral loads were still somewhat to considerably lower than at baseline (Fig. ). Interestingly, the increase paralleled the reappearance of WBCs in peripheral blood, a clear indicator of substantial engraftment. For two patients, we could also examine plasma samples collected at days 50, 80, and 110. As shown by the inserts in Fig. , at these times both patients exhibited plasma TTV loads higher than at baseline, indicating that TTV shedding into plasma had resumed and was as abundant as or even more abundant than that at the start of the study. Interestingly, the spectrum of TTV genogroups detected in plasma at this time differed substantially from pre-TBI (Table ), indicating that the patients were now replicating newly acquired TTVs, most likely transmitted by the graft or blood component transfusions required to sustain the procedure.Collectively, these findings provide solid quantitative evidence that hematopoietic stem cells represent by far the most important, if not the only source of the generally high TTV burdens found in the blood of infected individuals. The alternative explanation that hematopoietic cells or cytokines produced by them might stimulate other cells to replicate TTV seems less likely. Not only did plasma TTV loads fall dramatically during the myelosuppressed period, but also graft reconstitution was accompanied by a parallel return to high TTV loads. That TTVs have a preference for a highly cycling cell compartment is consistent with the well-established notion that single-stranded DNA viruses, including parvoviruses and circoviruses, have a marked preference for or replicate exclusively in DNA-synthesizing cells ( 14). The minimal levels of viremia that persisted during myelosuppression might suggest that some TTV replication takes place as well outside the hematopoietic compartment. However, since posttransplant the viral genogroups harbored by the patients were at least partly different from the ones harbored pretransplant, it is also possible that such low viral loads were generated by the hematopoietic cells infused into the patients.The viruses that lack an external lipid envelope are usually cytolytic for the cells in which they replicate. Future studies should therefore focus on clarifying which specific cell type or types within the hematopoietic cell compartment support TTV replication. A preferential replication within the lymphoid cell lineage might explain some of the immunomodulating properties attributed to the TTVs ( 6, 14, 17), while a preference for the erythroid lineage might explain the cases of aplastic anemia that have been associated with TTV infection ( 8, 11, 19). On the other hand, the circumstance that the great majority of TTV infections do not emerge clinically is most likely explained by the large regenerative potential of the hematopoietic compartment. 相似文献
8.
Effective wastewater treatment using microbial fuel cells (MFCs) will require a better understanding of how operational parameters
and solution chemistry affect treatment efficiency, but few studies have examined power generation using actual wastewaters.
The efficiency of wastewater treatment of a beer brewery wastewater was examined here in terms of maximum power densities,
Coulombic efficiencies (CEs), and chemical oxygen demand (COD) removal as a function of temperature and wastewater strength.
Decreasing the temperature from 30°C to 20°C reduced the maximum power density from 205 mW/m 2 (5.1 W/m 3, 0.76 A/m 2; 30°C) to 170 mW/m 2 (20°C). COD removals ( R
COD) and CEs decreased only slightly with temperature. The buffering capacity strongly affected reactor performance. The addition
of a 50-mM phosphate buffer increased power output by 136% to 438 mW/m 2, and 200 mM buffer increased power by 158% to 528 mW/m 2. In the absence of salts (NaCl), maximum power output varied linearly with wastewater strength (84 to 2,240 mg COD/L) from
29 to 205 mW/m 2. When NaCl was added to increase conductivity, power output followed a Monod-like relationship with wastewater strength.
The maximum power ( P
max) increased in proportion to the solution conductivity, but the half-saturation constant was relatively unaffected and showed
no correlation to solution conductivity. These results show that brewery wastewater can be effectively treated using MFCs,
but that achievable power densities will depend on wastewater strength, solution conductivity, and buffering capacity. 相似文献
9.
A new green microalgal species was isolated, identified and investigated for its biomass production and nutrient removal efficiency in dairy and winery wastewater in this study. The 18S rRNA-based phylogenetic analysis revealed that this new strain is a Diplosphaera sp. and was designated strain MM1. The growth of this strain was evaluated in different diluted dairy and winery wastewaters. The highest algal biomass production (up to 2.3 g L ?1) was obtained in dairy wastewater (D3; dairy wastewater 1:2 deionised water) after 14 days of culture. However, for winery wastewater, the highest algal biomass production (up to 1.46 g L ?1) was obtained in wastewater combination W2 (winery wastewater 1:1 deionised water) after 14 days of culture. Turbid dairy wastewater with high concentration of nitrogen and phosphorous slowed down the initial growth of the alga. However, at the end of day 14, biomass production was nearly twofold higher than that of winery wastewater. The findings from both types of wastewater suggest that Diplosphaera sp. MM1 has potential for its application in generating biomass with simultaneous remediation of nutrient-rich wastewater. 相似文献
10.
When TT virus (TTV) DNA was quantitated in whole blood and plasma aliquots from 27 viremic individuals by real-time detection PCR that can detect essentially all TTV genotypes, the TTV load was 6.9 +/- 3.5 (mean +/- standard deviation)-fold higher in the whole blood than in the plasma samples [P < 0.002 (paired t test)]. To clarify the reason for this difference, peripheral blood cells of various types including red blood cells, granulocytes (CD15+), B cells (CD19+), T cells (CD3+), monocytes (CD14+), and NK cells (CD3-/CD56+) were separated at a purity of 95.4-99.5% from each of three infected individuals with relatively high TTV viremia, and their TTV viral loads were determined. Red blood cells were uniformly negative, but the other cell types were positive for TTV DNA at various titers. In all three patients, the highest TTV load was found in granulocytes (4.2 x 10(4)-3.1 x 10(5) copies/10(6) cells), followed by monocytes (1.4-2.2 x 10(4) copies/10(6) cells) and NK cells (5.4-6.5 x 10(3) copies/10(6) cells); B and T cells were positive, with a low viral load (6.7 x 10(1)-2.7 x 10(3) copies/10(6) cells). These results indicate that TTV is distributed in various peripheral blood cell types at distinct levels, with the highest viral load in granulocytes, and that a significant proportion of the TTV DNA in peripheral blood is not identified by the standard plasma/serum DNA detection methods. 相似文献
11.
Myriophyllum elatinoides was reported to effectively treat wastewater by removing nitrogen (N) and phosphorus (P). However, little is known about the abundance and community structure of ammonia-oxidizing microorganisms associated with M. elatinoides purification systems. The objective of this research was to characterize the abundance and community structure of ammonia-oxidizing microorganisms in swine wastewater and determine the main nitrogen removal pathways. In this study, five different waters were treated by M. elatinoides in microcosms for one month. The five waters included tap water (Control), swine wastewater (SW), 50% diluted swine wastewater (50% SW), and two synthetic wastewaters: 200 mg NH 4
+-N L −1 (200 NH 4
+-N) and 400 mg NH 4
+-N L −1 (400 NH 4
+-N). The most dramatic changes were in NH 4
+-N and total N (TN) concentrations, with average removal rates of 84% and 90%, respectively, in the treatments containing swine wastewater. On days 7, 14, and 28, the dissolved oxygen (DO) increased by 81.8%, 210.4% and 136.5%, respectively, compared with on day 0, in the swine wastewater. The results also showed that the bacterial amoA (AOB) copy numbers in the sediments of the treatments were significantly higher than those of archaeal amoA (AOA) copy numbers ( p = 0.015). In addition, the high DO concentrations in swine wastewater responded well to the high abundance of AOB. The AOA and AOB community distributions were positively related with NO 3
-N and were negatively related with DO in swine wastewater treatments. In summary, our experimental results suggested that the M. elatinoides purification system could improve the activity of ammonia-oxidizing microorganisms and consequently might contribute to the significant N removal from the swine wastewater. 相似文献
12.
Aims: Torque teno virus (TTV) is a human DNA virus chronically infecting most healthy individuals worldwide and can be transmitted by faecal–oral route. The occurrence of TTV was evaluated in the streams crossing the city of Manaus (Brazilian Amazon) over a 1-year period, four times a year. Methods and Results: Fifty-two water samples were collected from 13 different locations. Viruses were concentrated from two litres of water by adsorption to negative membrane filters followed by ultrafiltration. TTV DNA was detected by PCR assays designed to detect all five TTV genomic groups. By conventional PCR, 19/52 (37%) samples were positive. By real-time PCR, TTV DNA could be detected in 48/52 (92%) samples. Viral loads ranged from 1300 to 746 000 genome equivalent per 100 ml of river water. Eleven distinct nucleotide sequences were obtained. Conclusions: Our results show the wide distribution and diversity of TTV among Manaus urban micro basins. Significance and Impact of the Study: The data presented here may contribute to substantiate TTV as a sensitive indicator of human contamination. 相似文献
13.
TT virus(TTV)DNA was tested by nested-PCR from sera of hepatitis patients and volunteer blood donors in Minnan area. The amplified segment was a 189 base pair region in TTV ORF2. A total of six sequences were obtained from three non-A to G hepatits patients and two from volunteer blood donors. The sequences were found to be with 82.9% to 99.3% homology to TTV Japanese strain and Chinese strain. The divergence of sequence in these six segments varied from 0.7% to 17.1%, which indicated that the TTV had been existing for a long time in this area. In the serum of a non-A to G hepatitis patient who was negative for TTV DNA in the 14th day of disease course turned to be positive in the 30th day, two TTV sequences were obtained which showed 92.1% nucleotide homology. It indicated that different TTV strains can co exist in the same person. This patient's blood had been transfused ten times between the collection of his TTV negative sample and his positive serum sample. Seven of the blood donors were traced and sampled for sera, of which three were positive for TTV. For all 161 patients tested, the history of exposure to blood products was associated with an increased risk of TTV infection(relative risk, 3.0; 95% confidence intervals, 1.89~4.81). 相似文献
14.
Axenic cultivation of biocontrol fungus Trichoderma viride was conducted on a synthetic medium and different wastewaters and wastewater sludges in shake flasks to search for a suitable
raw material resulting in higher biocontrol activity. Soluble starch based synthetic medium, dewatered municipal sludge, cheese
industry wastewater sludge, pre-treated and untreated pulp and paper industry wastewater and slaughter house wastewater (SHW)
were tested for T. viride conidia and protease enzyme production. The maximum conidia production followed the order, soluble starch medium (>10 9 c.f.u./mL), untreated pulp and paper industry wastewater (4.9 × 10 7 c.f.u./mL) > cheese industry wastewater (1.88 × 10 7 c.f.u./mL) ≈ SHW (1.63 × 10 7 c.f.u./mL) > dewatered municipal sludge (3.5 × 10 6 c.f.u./mL) > pre-treated pulp and paper industry wastewater (1.55 × 10 6 c.f.u./mL). The protease activity of T. viride was particularly higher in slaughterhouse wastewater (2.14 IU/mL) and dewatered municipal sludge (1.94 IU/mL). The entomotoxicity
of soluble starch based synthetic medium was lower (≈6090 SBU/μL) in contrast to other raw materials. The entomotoxicity inversely
decreased with carbon to nitrogen ratio in the growth medium and the conidia concentration and protease activity also contributed
to the entomotoxicity. The residual c.f.u./g formulation of T. viride conidia were up to approximately, 90% after 1 month at 4 ± 1 °C and about 70% after 6 months at 25 ± 1 °C. Thus, production
of T. viride conidia would help in marketability of low cost biopesticide from the sludge and safe reduction of pollution load. 相似文献
15.
Viruses resembling human TT virus (TTV) were searched for in sera from nonhuman primates by PCR with primers deduced from well-conserved areas in the untranslated region. TTV DNA was detected in 102 (98%) of 104 chimpanzees, 9 (90%) of 10 Japanese macaques, 4 (100%) of 4 red-bellied tamarins, 5 (83%) of 6 cotton-top tamarins, and 5 (100%) of 5 douroucoulis tested. Analysis of the amplification products of 90 to 106 nucleotides revealed TTV DNA sequences specific for each species, with a decreasing similarity to human TTV in the order of chimpanzee, Japanese macaque, and tamarin/douroucouli TTVs. Full-length viral sequences were amplified by PCR with inverted nested primers deduced from the untranslated region of TTV DNA from each species. All animal TTVs were found to be circular with a genomic length at 3.5 to 3.8 kb, which was comparable to or slightly shorter than human TTV. Sequences closely similar to human TTV were determined by PCR with primers deduced from a coding region (N22 region) and were detected in 49 (47%) of the 104 chimpanzees; they were not found in any animals of the other species. Sequence analysis of the N22 region (222 to 225 nucleotides) of chimpanzee TTV DNAs disclosed four genetic groups that differed by 36.1 to 50.2% from one another; they were 35.0 to 52.8% divergent from any of the 16 genotypes of human TTV. Of the 104 chimpanzees, only 1 was viremic with human TTV of genotype 1a. It was among the 53 chimpanzees which had been used in transmission experiments with human hepatitis viruses. Antibody to TTV of genotype 1a was detected significantly more frequently in the chimpanzees that had been used in transmission experiments than in those that had not (8 of 28 [29%] and 3 of 35 [9%], respectively; P = 0.038). These results indicate that species-specific TTVs are prevalent in nonhuman primates and that human TTV can cross-infect chimpanzees. 相似文献
16.
This study concerned the anaerobic treatment of five different industrial wastewaters with a diverse and complex chemical composition. The kinetics of biotransformation of this wastewater at different chemical oxygen demand (COD) were studied in a batch reactor. Wastewater from an amino acid producing industry (Fermex) and from a tank that received several types of wastewaters (collector) contained 0.83 g l−1 and 0.085 g l−1 sulfate, respectively. During the study period of 20 days, methane formation was observed in all types of wastewaters. Studies on COD biodegradation showed the reaction velocity was higher for Fermex wastewater and lower for collector wastewater, with values of 0.0022 h−1 and 0.0011 h−1, respectively. A lower methanogenic activity of 0.163 g CH4 day−1 g−1 volatile suspended solids (VSS) and 0.20 g CH4 day−1 g−1 VSS, respectively, was observed for paper producing and brewery wastewater. Adapted granular sludge showed the best biodegradation of COD during the 20-day period. The sulfate-reducing activity in pharmaceutical and collector wastewater was studied. A positive effect of sulfate-reducing activity on methanogenic activity was noted for both types of wastewaters, both of which contained sulfate ions. All reactions of methane generation for the tested industrial wastewaters were first-order. The results of this study suggest that the tested wastewaters are amenable to anaerobic treatment. 相似文献
17.
Newly discovered TT virus (TTV) is widely distributed in human populations. To understand more about the relationship between TTV and its hosts, we tested 400 sera from various nonhuman primates for the presence of TTV DNA by PCR assay. We collected serum samples from 24 different species of nonhuman primates. TTV DNA was determined by PCR with primers designed from the 5'-end region of the TTV genome. Nucleotide sequencing and phylogenetic analysis of viral genomes were also performed. TTV DNA was detected in 87 of 98 (89%) chimpanzees and 3 of 21 (14%) crab-eating macaques. Nucleotide sequences of the PCR products obtained from both animals were 80 to 100% identical between two species. In contrast, the sequences differed from TTV isolates in humans by 24 to 33% at the nucleotide level and 36 to 50% at the amino acid level. Phylogenetic analysis demonstrated that all TTV isolates obtained from simians were distinct from the human TTV isolates. Furthermore, TTV in simians, but not in humans, was classified into three different genotypes. Our results indicate that TTV in simians represents a group different from, but closely related to, TTV in humans. From these results, we tentatively named this TTV simian TTV (s-TTV). The existence of the s-TTV will be important in determining the origin, nature, and transmission of human TTV and may provide useful animal models for studies of the infection and pathogenesis of this new DNA virus. 相似文献
18.
Sphingomonas cloacae S-3 T, a nonylphenol (NP)-degrading bacterium, was evaluated for its utility in the remediation of NP-contaminated wastewater. In flask-scale experiments, S-3 T cells immobilized on porous polypropylene carriers (beads) efficiently degraded NP to concentrations routinely measured in aquatic environments [a few parts per billion (ppb), or micrograms per liter). Therefore, we constructed and evaluated a laboratory-scale wastewater treatment system with a 3-l carrier-filled column. The system worked properly and consistently removed several hundred ppb of NP to ecologically safe concentrations of less than 10 ppb in industrial wastewater without the addition of nutrients. The effect of wastewater pH on the system performance was also evaluated; and wastewater samples with pH values of 6 or 8 were treated efficiently without pH adjustment. These results suggest that a biotreatment system using NP-degrading bacteria can efficiently remediate industrial wastewater and contribute to the preservation of aquatic environments. 相似文献
20.
Response surface methodology was used to optimize spray drying process for producing biopesticide powders of Bacillus thuringiensis by using fermented broth of starch industry wastewater and wastewater sludge. Analysis of variance was carried out using
number of viable spores in the powder as dependent variable. The determination coefficients of models were 92 and 94% for
fermented broth of starch industry wastewater and wastewater sludge, respectively. Under the optimal conditions of the operational
parameters of spray drying, the numbers of viable spores were 2.2 × 10 8 and 1.3 × 10 8 CFU/mg in the dry powders for starch industry wastewater and wastewater sludge respectively, with a loss of viable spores
of 18 and 13% when compared with their respective fermented broths. The entomotoxicity (measured by the bioassay method) of
the powders obtained under optimal conditions showed a loss of 28 and 18% when compared with the fermented broth of starch
industry wastewater and wastewater sludge, respectively. The optimized results of spray drying were used for field application
calculations. The volume of fermented broth required to produce powder formulated product when compared with the volume required
for liquid formulation product in order to treat 1 ha of balsam fir was less and offered several advantages. 相似文献
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