Municipal landfill leachates induced chromosome aberrations in rat bone marrow cells

This study examined the potential mutagenic effects of raw and simulated leachates from Olushosun municipal solid waste (MSW) landfill using rat bone marrow chromosome aberration assay. Rawleachate obtained directly from the landfill and simulated leachate obtained via the American Society for Testing and Materials (ASTM) category-A extraction procedure were examined for their physical andchemical properties. Rats were intraperitoneally exposed to 1 - 25% concentrations of the leachates for 48 h. The erythroblasts of the bone marrow cells examined post treatment show structural chromosomalabnormalities such as breaks, gaps, rings and acentrics. The induction was dose dependent (r =0.80 and 0.85 for ORL and OSL, respectively). Physico-chemical and heavy metal analysis of the test samples showed that they contained high concentrations of toxic anions and cations that are capable of inducing mutation in living cells. The interaction of these constituents with the genetic material in the bone marrow cells of rat caused the observed chromosome aberrations. Our data indicate that MSW leachates can induce genotoxicity in rat and suggest potential health risk to human populations

Genotoxicity and mutagenicity of solid waste leachates: A review

Solid waste production is inevitable and its unsanitary disposal in the environment is of public and environmental health concern. Leachate, generated due to the infiltration of water/precipitation through the waste mass and the wastes biodegradation, is a mixture of dissolved organic matter, inorganic macro-components, heavy metals, xenobiotic organic compounds and microorganisms. Several studies have reported the acute toxicity of leachate using different end points, while evidences are accumulating on their potentials to induce genetic damage. In this wise, different short-term in vivo and in vitro bioassays are being utilized in the evaluations of genotoxicity and mutagenicity of leachates; and the possible mechanisms of genetic damage. This paper reviews reports on leachate-induced genetic damage. There is need for a shift from waste disposal to sustainable waste management. Awareness on possible health impacts or consequences of exposure to solid waste should also be created through health education.Keywords: Solid waste leachate, genotoxicity, mutagenicity, environmental pollutionAfrican Journal of BiotechnologyVol. 12(27), pp. 4206-422

Prevalence and gene frequencies of phenylthiocarbamide (PTC) taste sensitivity, ABO and Rhesus factor (Rh) blood groups, and haemoglobin variants among a Nigerian population

Background: Blood groups and phenylthiocarbamide (PTC) are the most studied genetic traits among human populations around the world. In most of these studies, PTC taste sensitivity was described as a bimodal autosomal trait inherited in a simple Mendelian recessive pattern.ABO blood group is the most studied blood groups followed by Rhesus factors (Rh) and haemoglobin variants. Information from the study of these traits is useful to biologists, geneticists, anthropologists and clinicians. No information on the prevalence and gene frequencies of thesetraits among a population from Nigeria. Aim: This study presents information on the prevalence and gene frequencies of PTC taste sensitivity, ABO blood group and Rhesus factor, and Haemoglobin variants from male and female Nigeriansexamined.Subjects and methods: A total of 232 (51.33%) male and 220 (48.67%) female Nigerians participated in this study. Filter paper impregnated with 81.25 mg/L of saturated solution of PTC wasused to determine PTC tasters, while blood group phenotypes, Rhesus factor and haemoglobintypes were determined by classical method. Hardy–Weinberg method was used to determine allelic frequencies and graphpad 5 computer software was used for the data processing.Results: The percentage frequency for non tasters of PTC was 29.42% with allele frequency t= 0.5424. There were more male (33.62%) non tasters than female (25.0%), but more female (75.0%) tasters than male (66.38%). This observation was statistically significant (p= 0.0444).Our findings support the bimodal inheritance of PTC taste sensitivity among Nigerians. Overall trend of ABO blood group was O > B >A > AB. This same trend was observed for females but differed for males (O> B = A> AB). O blood group was the highest while AB group was the least among studied Nigerians in both genders. The distribution pattern did not differ significantly (p= 0.1406) from those expected under Hardy–Weinberg Law. 93.14% of the studied population was Rh+ (DD and Dd) and there were more Rh+ males than females but more Rh females than males. The proportions and distributions of Rh factor amongstudied population did not show statistical significance (X2= 0.6047, df = 1, P = 0.4624). The overall allele frequency of the blood group as computed according to Hardy–Weinberg Law is r = 0.8201, q= 0.0977 and p= 0.0822. Similar trend in allele frequency was observed for both genders. The allele frequency for Rh+ (D) is 0.7381 and Rh (d)= 0.2619. This trend is also similar in both sexes. Among the six haemoglobin variants common to Nigerians CC was not detected in our study. The other five were observed in the order AA (76.55%)> AS (20.35%)> AC (1.99%) > SS (0.66%) >SC (0.44%). The overall allele frequency was A =0.8772, S =0.1106, C = 0.0122.Conclusion: The findings from this study provide information on the studied traits. It will provide background information for further studies and will be useful to clinicians, geneticists and anthropologists with respect to blood transfusion, marriage counseling and population studies

Haematological evaluation of Wistar rats exposed to chronic doses of cadmium, mercury and combined cadmium and mercury

Cadmium and mercury present in the environment, cause blood disorders. This study was conducted to evaluate the influence of cadmium, mercury and their combination on hematological parameters of Wistar rats. For this purpose, two different doses of each metal and their combination were administered orally for 28 days to six groups of five rats each. Two groups (A and B) were respectively exposed to CdCl2 (0.25 and 2.5 mg/kg), two other groups (C and D) respectively received HgCl2 (0.12 and 1.2 mg/kg) and the last two groups (E and F) were respectively treated with the combination of these two metals: (0.25 mg/kg Cd + 0.12 mg/kg Hg) and (2.5 mg/kg Cd + 1.2 mg/kg Hg). The control group (G) received the same volume of distilled water. At the end of exposure, bodies of rats were weighed and the whole blood was collected by retro-orbital sinus method for analysis of hematological parameters. The results of this study show a significant decrease (p<0.05) in white blood cells (WBC) in the lot treated with the combination (0.25 mg/kg Cd + 012 mg/kg Hg) and also indicate a significant decrease (p<0.05) in WBC, red blood cells (RBC), hemoglobin concentration (HGB) and the mean corpuscular hemoglobin concentration (MCHC) with high levels of mercury (2.5 mg/kg) and the combination (2.5 mg/kg Cd + 1.2 mg/kg Hg). An increase in the number of platelet count (PLT) in all intoxicated lots was observed.Keywords: Cadmium, mercury, hematology, blood parameters, ratsAfrican Journal of BiotechnologyVol. 12(23), pp. 3731-373

Genotoxicity assessment of a pharmaceutical effluent using four bioassays

Pharmaceutical industries are among the major contributors to industrial waste. Their effluents when wrongly handled and disposed of endanger both human and environmental health. In this study, we investigated the potential genotoxicity of a pharmaceutical effluent, by using the Allium cepa, mouse- sperm morphology, bone marrow chromosome aberration (CA) and micronucleus (MN) assays. Some of the physico-chemical properties of the effluent were also determined. The A. cepa and the animal assays were respectively carried out at concentrations of 0.5, 1, 2.5, 5 and 10%; and 1, 5, 10, 25 and 50% of the effluent. There was a statistically different (p < 0.05), concentration-dependent inhibition of onion root growth and mitotic index, and induction of chromosomal aberrations in the onion and mouse CA test. Assessment of sperm shape showed that the fraction of the sperm that was abnormal in shape was significantly (p < 0.05) greater than the negative control value. MN analysis showed a dose-dependent induction of micronucleated polychromatic erythrocytes across the treatment groups. These observations were provoked by the toxic and genotoxic constituents present in test samples. The tested pharmaceutical effluent is a potentially genotoxic agent and germ cell mutagen, and may induce adverse health effects in exposed individuals

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency–Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research

Absorption and bioaccumulation of heavy metals in giant African land snails (Archachatina marginata)

Interest in the production of micro-livestock to supply the required protein has resulted in the intensive production of Snails. Wild and domesticated snails fed on contaminated feed may accumulate heavy metals which may be injurious to the consumers. Although toxicity and the resulting threat to human health of any contaminant are, of course, a function of concentration, it is well-known that chronicexposure to heavy metals and metalloids at relatively low levels can cause adverse effects. This study aimed at investigating the ability and effects (if any) of heavy metal accumulation in Giant African Land Snails (Archachatina marginata). 120 A. marginata growers were randomly allotted to 2 feed treatments (T1: Heavy metal contaminated pawpaw fruits and leaves; and T2: Heavy metal free pawpaw fruits and leaves) in a Completely Randomized Design. Each treatment has 4 replicates containing 15 snails per replicate. The experimental diets were fed ad libitum for the period of 12 weeks during which recommended management practices were strictly adhered to. Data were collected on shell length, shell width, and live weight. Resultsobtained revealed that giant land snails possess the ability to bio-accumulate heavy metals in their tissues and this accumulation could have a reducing effect on all studied parameters, caused pathological lesions of the edible foot and mortality. It was thus recommended that feeds given to caged snails, and even other animals, should be ascertained heavy metals free before offered.Keywords: Heavy metals, Bioaccumulation, Giant Land Snails, Contamination, Food safety