Heavy Metals in Fish from Lakes in Latvia: Concentrations and Trends of Changes

The purpose of this study was to evaluate the level of heavy metal contamination of perch (Perca fluviatilis) from inland waters in Latvia. The level of metal (Cd, Cu, Co, Pb, Ni, Mn, Zn, Fe) accumulation in fish tissues (muscle, liver, and gills) relative to contamination level, gender, age, and tissue type were studied in fish samples from 14 bog (dystrophic) lakes and 23 lakes of different trophic status. Samples from some sites in the vicinity of the largest cities had significantly increased metal levels. In contrast, fish tissues from bog lakes had very low metal levels, possibly because of the high concentrations of natural organic matter in these waters.     

Evaluation of the efficacy and safety of the Rift Valley Fever Clone 13 vaccine in sheep

The efficacy and safety of the naturally attenuated Rift Valley Fever (RVF) Clone 13 vaccine were evaluated in ovines in three different experiments involving 38 ewes at different stages of pregnancy, their offsprings and four rams. In Experiment 1, 4 rams and a total of 13 pregnant ewes were vaccinated and monitored during vaccination and after a challenge with a virulent RVF virus. The ewes were vaccinated at either 50 or 100 days of pregnancy and some were challenged after lambing. In Experiment 2, nine oestrus-synchronized ewes were vaccinated at 50 days of pregnancy and challenged at 100 days of pregnancy together with 5 unvaccinated ewes at the same stage of pregnancy. In Experiment 3, 16 oestrus-synchronized ewes were vaccinated with 3 different doses of the RVF Clone 13 vaccine and challenged together with unvaccinated pregnant ewes at either 30 or 50 days of pregnancy. The results from the three experiments indicated that the vaccine did not induce clinical manifestation of RVF such as abortion in pregnant ewes, teratogeny in their offsprings, or pyrexia in all vaccinated animals. Vaccination with RVF Clone 13 vaccine also prevented clinical RVF following virulent challenge at different stages of pregnancy while unvaccinated control ewes showed pyrexia, aborted or died of RVF. A vaccine dose–response effect was also observed.     

Water Quality and Trace Metal Distribution in a Pristine Lake in the Lake Basin in Kenya

Water and surface sediment samples taken from various locations within Lake Kanyaboli in the Lake Victoria basin were analysed to determine the concentration and distribution of heavy metals. There were wide ranges in concentrations of the metals among the sampling points analysed. Sediment concentrations (microg/g dry weight) ranged from n.d.-2.54 (Ag), 0.25-1.08 (Cd), 0.89-1.64 (Co), 3.7-7.73 (Cr), 1.80-30.27 (Cu), 1073-2627 (Mn), 22.61-55.60 (Ni), 11.42-153.9 (Pb), 40.46-154.7 (Sn) and 65.0-146.5 (Zn). Dissolved metal concentrations (microg/L) ranged from n.d.-9.22 (Ag), n.d.-5.54 (Cd), n.d.-8.30 (Co), 5.26-60.82 (Cr), 10.96-43.11 (Cu), 184.7-375.9 (Mn), 1.84-38.3 (Ni), 5.98-47.77 (Pb), n.d.-540.6 (Sn) and 14.5-55.9 (Zn). Compared with WHO standards and other freshwaters worldwide, this lake was found to be unpolluted, with all metals, except Mn, being detected at concentrations lower than the highest desirable levels and maximum permissible levels. Some of the toxic metals, Cu, Zn, Pb and Cd (in sediment) and Ag, Co and Pb (in water) were detected at lower concentrations than those found in the polluted Kisumu Pier in Winam Gulf in the Lake basin, which confirms the anthropogenic influence on the latter.     

Safety and efficacy of Rift Valley fever Smithburn and Clone 13 vaccines in calves

Two modified live attenuated vaccines against the disease Rift Valley fever (RVF) have been tested for safety and efficacy in young calves. The RVF Smithburn vaccine produced in South Africa and used successfully to prevent and control the disease in endemic sub-Saharan countries was compared to the candidate vaccine RVF Clone 13. Five sero-negative calves per vaccine group were vaccinated with a single dose of each vaccine and tested for antibody response. All vaccinated calves were challenged with a highly virulent RVF virus together with five unvaccinated calves used as control of the challenge. Protection was confirmed in all vaccinated animals as they did not show any clinical signs typical of RVF. A good neutralizing antibody response was induced post-vaccination and no viraemia could be detected post-challenge in calves of both vaccine groups. All non-vaccinated control animals showed clinical symptoms of RVF, high viraemia and were euthanized. This study reported the first case of blindness in cattle resulting from virulent RVF virus infection in unvaccinated calves used as negative controls.     

Development of a Rift Valley fever virus viremia challenge model in sheep and goats

Rift Valley fever virus (RVFV), a member of the family Bunyaviridae, causes severe to fatal disease in newborn ruminants, as well as abortions in pregnant animals; both preventable by vaccination. Availability of a challenge model is a pre-requisite for vaccine efficacy trials. Several modes of inoculation with RVFV ZH501 were tested on goats and sheep. Differences in development of infectious viremia were observed between animals inoculated with RVFV produced in mosquito C6/36 cells compared to Vero E6 cell-produced inoculum. Only C6/36-RVFV inoculation led to development of viremia in all inoculated sheep and goats. The C6/36 cell-produced RVFV appeared to be more infectious with earlier onset of viremia, especially in sheep, and may also more closely represent a field situation. Goats were somewhat more resistant to the disease development with lower and shorter infectious virus viremia, and with only some animals developing transient increase in rectal temperature in contrast to sheep. In conclusion, a challenge protocol suitable for goat and sheep vaccine efficacy studies was developed using subcutaneous inoculation of 10⁷ PFU per animal with RVFV ZH501 produced in C6/36 cells.     

Heavy Metals in the Surface Sediments in Lanzhou Reach of Yellow River,China

The heavy metal pollution and their fractionations in the surface sediments of Yellow River in Lanzhou Reach was monitored for arsenic (As), lead (Pb), Zinc (Zn), chromium (Cr), copper (Cu) and manganese (Mn) with Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). The mean sediment concentrations (in μg/g dry weight) ranged from 13.68–48.11 (As), 26.39–77.66 (Pb), 89.80–201.88 (Zn), 41.49–128.30 (Cr), 29.72–102.22 (Cu), and 773.23–1459.69 (Mn). Spatial distribution showed that each heavy metal concentration remained almost constant in this reach. Correlation coefficients indicated that metals were not strongly associated with sediment sand content or organic carbon content (f_oc). Labile fractions (exchangeable + carbonate + Fe–Mn oxide) had no significant correlations with sand content or f_oc, either. Results from the present study are useful for understanding heavy metal distributions in a torrential river sediment environment.     

Stability of a formalin-inactivated Rift Valley fever vaccine: Evaluation of a vaccination campaign for cattle in Mozambique

In Africa and the Arabian Peninsula, outbreaks of Rift Valley fever (RVF) are characterized by abortions in gestating animals and high mortality rates among domestic ruminants. An immunization program using a formalin-inactivated vaccine was initiated in Mozambique in 2002 to control RVF in cattle. In this intervention, the vaccine must be transported for more than a week within the country before it can be administered to the animals, and it is practically impossible to maintain low storage temperatures during that time. Here, we evaluated the influence of transportation conditions on the efficacy of the vaccine. Sixty-three previously unvaccinated and RVF virus seronegative cattle were divided into four groups, which were given vaccine that had been stored for 1 week at 4 °C (n = 9, group A), at 25 °C (n = 8, group B), or alternating between 4 and 25 °C (n = 8, group C), or under the temperature conditions ordinarily occurring during transportation within Mozambique (n = 38, group D). The antibody responses induced were monitored for 6–9 months and in some animals up to 21 months. Two immunizations (3 weeks apart) with the formalin-inactivated vaccine induced a long-lasting neutralizing antibody response that was still detectable up to 21 months later. The antibody titers in the animals did not differ significantly between the temperature-assigned vaccine groups A, B, and C, whereas they were significantly higher in group D. These results show that the formalin-inactivated RVF virus vaccine is stable, and, importantly, it is not adversely affected by the variation in temperature that ordinarily occurs during transport within Mozambique.     

马尾藻中几种金属元素含量及存在形态测定

以马尾藻为原料,采用不同的溶剂进行提取,分别得到脂溶性组分、水溶性组分、酸溶性组分、碱溶性组分和残渣组分;利用原子吸收分光光度法测定其中Ca、Zn、Mg、Pb、Cd等5种金属元素的含量。结果表明:所测定的5种元素中,Ca在马尾藻中含量最高,而Pb含量最低;上述金属元素在马尾藻中以多种形态共存。     

Immunogenicity and safety of an inactivated Rift Valley fever vaccine in a 19-year study

An investigational, formalin-inactivated Rift Valley fever (RVF) vaccine, known as The Salk Institute-Government Services Division (TSI-GSD) 200 vaccine, was administered to 1860 at-risk subjects (5954 doses) between 1986 and 2004 as a three-dose primary series (days 0, 7, and 28) followed by booster doses as needed for declining titers. An initial positive serological response (PRNT₈₀ ≥ 1:40) to the primary series was observed in 90% of subjects. Estimate of the PRNT₈₀ response half-life in initial responders to the primary series by Kaplan-Meier plot was 315 days after the primary series dose 3. Differences in a serological response were observed at 2 weeks after dose 3 of the primary series between vaccine lots and for gender (women > men); a trend was observed for age (<40 years). When response to the primary series was measured by PRNT₅₀ titer ≥1:40, nearly all subjects (99.1%) responded. In individuals not initially responding to the primary series (PRNT₈₀ < 1:40), a response was observed in most subjects after receiving only one booster dose. Immune response (all subjects) to subsequent booster doses for a declining titer (PRNT₈₀ < 1:40) was 98.4%. The vaccine was well-tolerated; vaccine-related adverse reactions were generally mild and self-limited. Differences in adverse events were observed with vaccine lot and sex. The data support the safety and immunogenicity of the inactivated RVF vaccine, and may serve as a standard of comparison for immunogenicity and safety for future RVF vaccines.     

Safety and immunogenicity of recombinant Rift Valley fever MP-12 vaccine candidates in sheep

The safety and immunogenicity of two authentic recombinant (ar) Rift Valley fever (RVF) viruses, one with a deletion in the NSs region of the S RNA segment (arMP-12ΔNSs16/198) and the other with a large deletion of the NSm gene in the pre Gn region of the M RNA segment (arMP-12ΔNSm21/384) of the RVF MP-12 vaccine virus were tested in crossbred ewes at 30–50 days of gestation. First, we evaluated the neutralizing antibody response, measured by plaque reduction neutralization (PRNT₈₀), and clinical response of the two viruses in groups of four ewes each. The virus dose was 1 × 10⁵ plaque forming units (PFU). Control groups of four ewes each were also inoculated with a similar dose of RVF MP-12 or the parent recombinant virus (arMP-12). Neutralizing antibody was first detected in 3 of 4 animals inoculated with arMP-12ΔNSm21/384 on Day 5 post inoculation and all four animals had PRNT₈₀ titers of ≥1:20 on Day 6. Neutralizing antibody was first detected in 2 of 4 ewes inoculated with arMP-12ΔNSs16/198 on Day 7 and all had PRNT₈₀ titers of ≥1:20 on Day 10. We found the mean PRNT₈₀ response to arMP-12ΔNSs16/198 to be 16- to 25-fold lower than that of ewes inoculated with arMP-12ΔNSm21/384, arMP-12 or RVF MP-12. No abortions occurred though a single fetal death in each of the arMP-12 and RVF MP-12 groups was found at necropsy. The poor PRNT₈₀ response to arMP-12ΔNSs16/198 caused us to discontinue further testing of this candidate and focus on arMP-12ΔNSm21/384. A dose escalation study of arMP-12ΔNSm21/384 showed that 1 × 10³ plaque forming units (PFU) stimulate a PRNT₈₀ response comparable to doses of up to 1 × 10⁵ PFU of this virus. With further study, the arMP-12ΔNSm21/384 virus may prove to be a safe and efficacious candidate for a livestock vaccine. The large deletion in the NSm gene may also provide a negative marker that will allow serologic differentiation of naturally infected animals from vaccinated animals.     

Analysis of Several Heavy Metals in Wild Edible Mushrooms from Regions of China

The metal (Cu, Ni, Cd, Hg, As, Pb) contents in wild edible mushrooms collected from three different sites in China were determined by atomic absorption spectrometry and atomic fluorescence spectrometry. All element concentrations were determined on a dry weight basis. A total of 11 species was studied, five being from the urban area and six from rural areas in China. The As content ranged from 0.44 to 1.48 mg/kg. The highest As content was seen in Macrolepiota crustosa from the urban area, and the lowest in Russula virescens from rural areas. A high Ni concentration (1.35 mg/kg) was found in Calvatia craniiformis from the urban area. The lowest Ni level was 0.11 mg/kg, for the species R. virescens and Cantharellus cibarius. The Cu content ranged from 39.0 to 181.5 mg/kg. The highest Cu content was seen in Agaricus silvaticus and the lowest in C. cibarius. The Pb content ranged from 1.9 to 10.8 mg/kg. The highest Pb value was found in C. craniiformis. The Cd content ranged from 0.4 to 91.8 mg/kg. The highest Cd value was found in M. crustosa. The Hg content ranged from 0.28 to 3.92 mg/kg. The highest Hg level was found in Agaricus species. The levels of the heavy metals Cd, Pb, and Hg in the studied mushroom species from urban area can be considered high. The metal-to-metal correlation analysis supported they were the same source of contamination. High automobile traffic was identified as the most likely source of the contamination. Based upon the present safety standards, consumption of those mushrooms that grow in the polluted urban area should be avoided.     

入境船舶压舱水中重金属元素监测初报

〔目的〕了解入境船舶载自境外的压舱水中重金属元素污染情况。〔方法〕无菌采集入境船舶载自境外的压舱水样本,送实验室进行包括镉、铬、铅、汞、砷、铜、镍、锌等重金属元素检测。〔结果〕从河北三个港口入境船舶36艘次采集样本36份,进行重金属检测。其中检出铅1艘次,船舶压舱水阳性率为2.78%(1/36);检出锌36艘次,船舶压舱水阳性率为100.00%(36/36);检出镍16艘次,船舶压舱水阳性率为44.44%(16/36);检测铜8艘次,7艘次为阳性,船舶压舱水阳性率为87.50%(7/8)。铬、镉、汞、砷未检出。〔结论〕入境船舶载自境外的压舱水重金属污染非常严重,应引起相关部门的高度重视。     

Rift Valley Fever and a New Paradigm of Research and Development for Zoonotic Disease Control

Although Rift Valley fever is a disease that, through its wider societal effects, disproportionately affects vulnerable communities with poor resilience to economic and environmental challenge, Rift Valley fever virus has since its discovery in 1931 been neglected by major global donors and disease control programs. We describe recent outbreaks affecting humans and animals and discuss the serious socioeconomic effects on the communities affected and the slow pace of development of new vaccines. We also discuss the mixed global response, which has largely been fueled by the classification of the virus as a potential bioterrorism agent and its potential to migrate beyond its traditional eastern African boundaries. We argue for a refocus of strategy with increased global collaboration and a greater sense of urgency and investment that focuses on an equity-based approach in which funding and research are prioritized by need, inspired by principles of equity and social justice.     

基于中国居民疾病发病和死亡情况的环境重金属污染健康风险评估标准探讨

重金属污染日趋严峻,严重影响了人们的生活质量,而健康风险评估可有效地应用于环境管理决策.基于健康风险评估标准制定的原则,通过结合中国居民慢性病的患病率和死亡率现状,参照不同国家的健康风险评估标准,对适合中国人群的环境重金属污染健康风险评估标准进行探讨.     

深圳某海鲜市场所售牡蛎体内重金属含量及评价

目的了解深圳某海鲜市场所售牡蛎中重金属含量,以便更好地开展卫生质量监控。方法采集深圳某海鲜市场中牡蛎,测定牡蛎中5种重金属（Pb、Cd、Cr、Hg及无机As）含量,根据无公害食品水产品有毒有害物质标准限量对牡蛎的食用安全性进行评估。结果所检牡蛎中Cd含量均高于无公害水产品质量安全标准,含量范围在1．04～2．24mg／kg之间,而Pb、Cr、无机As、Hg4种重金属的含量均低于安全标准。结论深圳某海鲜市场所售牡蛎重金属Cd含量均超标,卫生质量欠佳。     

Safety and immunogenicity of a mutagenized,live attenuated Rift Valley fever vaccine,MP-12, in a Phase 1 dose escalation and route comparison study in humans

Rift Valley fever (RVF) poses a risk as a potential agent in bioterrorism or agroterrorism. A live attenuated RVF vaccine (RVF MP-12) has been shown to be safe and protective in animals and showed promise in two initial clinical trials. In the present study, healthy adult human volunteers (N = 56) received a single injection of (a) RVF MP-12, administered subcutaneously (SQ) at a concentration of 10^4.7 plaque-forming units (pfu) (SQ Group); (b) RVF MP-12, administered intramuscularly (IM) at 10^3.4 pfu (IM Group 1); (c) RVF MP-12, administered IM at 10^4.4 pfu (IM Group 2); or (d) saline (Placebo Group). The vaccine was well tolerated by volunteers in all dose and route groups. Infrequent and minor adverse events were seen among recipients of both placebo and RVF MP-12. One subject had viremia detectable by direct plaque assay, and six subjects from IM Group 2 had transient low-titer viremia detectable only by nucleic acid amplification. Of the 43 vaccine recipients, 40 (93%) achieved neutralizing antibodies (measured as an 80% plaque reduction neutralization titer [PRNT₈₀]) as well as RVF-specific IgM and IgG. The highest peak geometric mean PRNT₈₀ titers were observed in IM Group 2. Of 34 RVF MP-12 recipients available for testing 1 year following inoculation, 28 (82%) remained seropositive (PRNT₈₀ ≥ 1:20); this included 20 of 23 vaccinees (87%) from IM Group 2. The live attenuated RVF MP-12 vaccine was safe and immunogenic at the doses and routes studied. Given the need for an effective vaccine against RVF virus, further evaluation in humans is warranted.     

Heavy Metals in Water and Surface Sediments in Winam Gulf of Lake Victoria, Kenya

No abstract available.     

Concentrations and Distribution of Mercury and Other Heavy Metals in Surface Sediments of the Yatsushiro Sea including Minamata Bay, Japan

The concentrations and distribution of heavy metals, such as mercury, zinc, copper, lead, and iron in surface sediments from 234 stations of the Yatsushiro Sea including Minamata bay were investigated. High concentrations of mercury were found in sediments from Minamata bay and its vicinity, but the levels decreased gradually with distance from the bay. The concentrations of mercury in sediments decreased gradually from south to north of the Yatsushiro Sea. These imply the lack of movement of mercury from Minamata bay to the northern Yatsushiro Sea. The geographical profiles of zinc and copper were contrary to that found for mercury, indicating the presence of natural and anthropogenic sources of copper and zinc in the northern Yatsushiro Sea.     

Rift Valley fever virus: A review of diagnosis and vaccination,and implications for emergence in Europe

Rift Valley fever virus (RVFV) is a mosquito-borne virus, and is the causative agent of Rift Valley fever (RVF), a zoonotic disease characterised by an increased incidence of abortion or foetal malformation in ruminants. Infection in humans can also lead to clinical manifestations that in severe cases cause encephalitis or haemorrhagic fever. The virus is endemic throughout much of the African continent. However, the emergence of RVFV in the Middle East, northern Egypt and the Comoros Archipelago has highlighted that the geographical range of RVFV may be increasing, and has led to the concern that an incursion into Europe may occur. At present, there is a limited range of veterinary vaccines available for use in endemic areas, and there is no licensed human vaccine. In this review, the methods available for diagnosis of RVFV infection, the current status of vaccine development and possible implications for RVFV emergence in Europe, are discussed.