Renal responses to acute lead waterborne exposure in the freshwater rainbow trout (Oncorhynchus mykiss)

The possible nephrotoxic effects of waterborne lead exposure (as Pb(NO₃)₂) were investigated in the freshwater rainbow trout (Oncorhynchus mykiss). Kidney lead accumulation was time-dependent, increasing upon exposure to 0.57 ± 0.01 mg dissolved Pb L⁻¹ for up to 96 h with a significantly higher burden occurring in the posterior kidney compared to the anterior segment. Urine analyses in trout exposed to 1.20 ± 0.09 mg dissolved Pb L⁻¹ revealed a significant increase in urinary lead excretion rate throughout 96 h of exposure. Urine flow rate and glomerular filtration rate (GFR) were not impacted with the exception of a significant decrease in GFR from 84 to 96 h in lead-exposed trout. Urine pH decreased significantly over time in lead-exposed fish. Correspondingly, urine ammonia excretion rate showed a marked increase from 48 h onwards. In experimental fish, urine glucose excretion was significantly greater by 96 h while urine lactate, urea and protein excretion were not significantly altered by lead exposure. The urine excretion rate of Ca²⁺ increased significantly by approximately 43% after only 24 h of lead exposure, and was maintained at a higher rate than controls for up to 96 h. Magnesium excretion increased in a time-dependent fashion, reaching a two- to three-fold rise by 96 h. In contrast, rates of Na⁺ and Cl⁻ excretion were decreased in experimental fish by approximately 30% by 48 h, this trend continuing for the duration of lead-exposure. There were no changes in any of these parameters in similarly treated control fish. Clearance ratio analyses indicated progressive decreases in the net reabsorption efficiencies of the renal system for Ca²⁺, Mg²⁺, Pb, and glucose, suggesting that the active tubular transport mechanisms for these substances were inhibited by lead exposure, while Na⁺, K⁺, Cl⁻, lactate, and protein reabsorptions were unaffected. Net ammonia secretion increased. We conclude that changes in renal function both reflect and help to minimize some of the associated disturbances in systemic physiology. Lead-induced ionoregulatory toxicity in rainbow trout, particularly the disturbance of Ca²⁺ homeostasis, is not exclusively a branchial phenomenon, but is in part a result of disruption of ionoregulatory mechanisms at the kidney. This action of lead outside the gills is critical to consider when developing guidelines for water quality.     

Toxicological effects of clofibric acid and diclofenac on plasma thyroid hormones of an Indian major carp,Cirrhinus mrigala during short and long-term exposures

In the present investigation, the toxicity of most commonly detected pharmaceuticals in the aquatic environment namely clofibric acid (CA) and diclofenac (DCF) was investigated in an Indian major carp Cirrhinus mrigala. Fingerlings of C. mrigala were exposed to different concentrations (1, 10 and 100 μg L⁻¹) of CA and DCF for a period of 96 h (short term) and 35 days (long term). The toxic effects of CA and DCF on thyroid hormones (THs) such as thyroid stimulating hormone (TSH), thyroxine (T₄) and triiodothyronine (T₃) levels were evaluated. During the short and long-term exposure period TSH level was found to be decreased at all concentrations of CA (except at the end of 14^th day in 1 and 10 μg L^−l and 21^st day in 1 μg L^−l) whereas in DCF exposed fish TSH level was found to be increased when compared to control groups. T₄ level was found to be decreased at 1 and 100 μg L^−l of CA exposure at the end of 96 h. However, T₄ level was decreased at all concentrations of CA and DCF during long-term (35 days) exposure period. Fish exposed to all concentrations of CA and DCF had lower level of T₃ in both the treatments. These results suggest that both CA and DCF drugs induced significant changes (P < 0.01 and P < 0.05) on thyroid hormonal levels of C. mrigala. The alterations of these hormonal levels can be used as potential biomarkers in monitoring of pharmaceutical drugs in aquatic organisms.     

A study of genotoxicity and oxidative stress induced by mercuric chloride in the marine polychaete Perinereis aibuhitensis

The marine polychaete worm Perinereis aibuhitensis was used to study the genotoxic effects of mercuric chloride by means of the comet assay and micronucleus (MN) test. P. aibuhitensis was subjected in vivo to two different concentrations of mercuric chloride (0.05 mg L⁻¹ and 0.5 mg L⁻¹) for 96 h. The comet assay of coelomocytes demonstrated that TailDNA% values increased with extended exposure to or increased concentrations of HgCl₂ (p < 0.01). The frequency of MNs was the highest in the treatment with 96 h of exposure at all concentrations (p < 0.01). The genotoxic effect of HgCl₂ was both dose- and time-dependent in exposed P. aibuhitensis. The activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidases (GPx) were also estimated. Significant variations in antioxidant enzyme activities depended on the sampling time and the concentrations of mercuric chloride. Compared with the control, the activities of the antioxidant enzymes (SOD and GPx) were elevated at the lower concentration of mercuric chloride (0.05 mg L⁻¹) (p < 0.05) for shorter exposure periods (24 h and 72 h). At the higher concentration of mercury (0.5 mg L⁻¹), the activities of GPx and SOD were inhibited; no variation was observed. These results proved that the use of the comet assay and MN test in coelomocytes of P. aibuhitensis is appropriate for determining the levels of DNA damage and that P. aibuhitensis is a species that is sensitive to mercury pollutants. This species may be considered a suitable candidate for monitoring marine heavy metal pollution.     

In vivo effects of deoxynivalenol (DON) on innate immune responses of carp (Cyprinus carpio L.)

Deoxynivalenol (DON) is one of the most important members of Fusarium toxins since it often can be found in relevant concentrations in animal feeds. The effects of this group of toxins on fish are mostly unknown. The present study shows results from a feeding trial with carp (Cyprinus carpio L.) using three different concentrations of DON (352 μg kg⁻¹, 619 μg kg⁻¹, and 953 μg kg⁻¹ final feed, respectively) which are comparable to levels found in commercial fish feeds. Effects on growth and mass of fish were not observed during this 6 weeks lasting experiment. Only marginal DON concentrations were found in muscle and plasma samples. Blood parameters were not influenced although smaller erythrocytes occurred in fish treated with 352 μg kg⁻¹ DON. Analysis of antioxidative enzymes in erythrocytes showed increased superoxid dismutase and catalase activities in fish fed the low-dose feed. Immunosuppressive effects of DON were confirmed whereby cytotoxic effects on immune cells only partly explained the impairment of innate immune responses. Exact polarization of the immune system into pro-inflammatory or anti-inflammatory responses due to DON exposure should be clarified in further experiments, especially since the current results raise concern about impaired immune function in fish raised in aquaculture.     

Oxidative stress responses in zebrafish Danio rerio after subchronic exposure to atrazine

Atrazine is one of the most used pesticides all over the world and it is frequently detected in surface water. The aim of this study was to investigate if zebrafish exposure to atrazine could induce oxidative stress and changes in detoxifying system. Juvenile fish were exposed to sublethal concentrations of 0.3, 3, 30, or 90 μg L⁻¹ for 28 days. The level of oxidized lipids increased in experimental groups exposed to atrazine at 30 and 90 μg L⁻¹ compared to control. Activity of glutathione S-transferase decreased in group with the highest concentration compared to control. A significant decline was observed in catalase activity in all experimental groups compared to control. Activity of superoxide dismutase increased only in experimental group exposed to atrazine at 30 μg L⁻¹ compared to control. Activity of glutathione peroxidase and reductase (GR) increased in experimental groups exposed to atrazine at 0.3 (only for GR activity) and 90 μg L⁻¹ compared to control. Our results showed that atrazine exposure had profound influence on the oxidative stress markers and detoxifying enzyme of the exposed zebrafish. The changes in antioxidant enzyme activities could be an adaptive response to protect the fish from the atrazine-induced toxicity.     

Oxidative stress responses in gills of goldfish,Carassius auratus,exposed to the metribuzin-containing herbicide Sencor

Metribuzin belongs to the family of asymmetrical triazine compounds and is an active ingredient in many commercial herbicides including Sencor. Effects on goldfish (Carassius auratus L.) of exposure for 96 h to 7.14, 35.7 or 71.4 mg L⁻¹ Sencor 70 WG (corresponding to 5, 25 and 50 mg L⁻¹ of metribuzin) were examined by evaluating oxidative stress markers and activities of antioxidant and associated enzymes in gills. Fish exposed to the lowest Sencor concentration (7.14 mg L⁻¹) showed a 94% increase in levels of protein carbonyls in gills as well as 45% and 144% increases in the activities of glutathione peroxidase and glutathione-S-transferase. Exposure to the highest Sencor concentration (71.4 mg L⁻¹) resulted in reduced levels of protein carbonyls by 56% and lipid peroxides by 40%, as compared with controls, but enhanced levels of low and high molecular mass thiols by 71% and 36%, respectively. The activities of superoxide dismutase, glutathione peroxidase and glutathione-S-transferase were increased in gills of goldfish exposed to 71.4 mg L⁻¹ Sencor. At any concentration tested, Sencor did not affect the activities of glutathione reductase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase or acetylcholine esterase in gills. The results of this study indicate that acute exposure of goldfish to Sencor had effect on free radical processes in gills and glutathione-dependent antioxidants effectively protect proteins and lipids from oxidation.     

Urinary analysis reveals high deoxynivalenol exposure in pregnant women from Croatia

In this pilot survey the levels of various mycotoxin biomarkers were determined in third trimester pregnant women from eastern Croatia. First void urine samples were collected and analysed using a “dilute and shoot” LC–ESI–MS/MS multi biomarker method. Deoxynivalenol (DON) and its metabolites: deoxynivalenol-15-glucuronide and deoxynivalenol-3-glucuronide were detected in 97.5% of the studied samples, partly at exceptionally high levels, while ochratoxin A was found in 10% of the samples. DON exposure was primarily reflected by the presence of deoxynivalenol-15-glucuronide with a mean concentration of 120 μg L⁻¹, while free DON was detected with a mean concentration of 18.3 μg L⁻¹. Several highly contaminated urine samples contained a third DON conjugate, tentatively identified as deoxynivalenol-7-glucuronide by MS/MS scans. The levels of urinary DON and its metabolites measured in this study are the highest ever reported, and 48% of subjects were estimated to exceed the provisional maximum tolerable daily intake (1 μg kg⁻¹ b.w.).     

In vivo sustained dermal delivery and pharmacokinetics of interferon alpha in biphasic vesicles after topical application

Biphasic vesicles, a novel nanostructured lipid-based delivery system show potential for topical application of interferon alpha (IFN α) for the treatment of human papillomavirus (HPV) infections (anogenital warts). Dermal delivery of IFN α encapsulated in biphasic vesicles (BPV-IFN α), applied topically to the skin, was characterized in a guinea pig model.BPV-IFN α (1 g, 2 MIU/g) was topically applied either as a single or multiple treatments on the skin of guinea pigs. As a comparison with currently used regimens, IFN α solution was administered intravenously or intradermally. Skin and serum samples were collected over 96 h, IFN α levels were determined by an antiviral assay, and half-life (t_1/2) and elimination (k) rates were calculated.Topical BPV-IFN α treatment resulted in maximum skin levels (about 100,000 U/100 cm²) of IFN α within 6 h and maintained for 72–96 h. Clearance from the skin after intradermal injections was initially fast (t_1/2 0.62 h, k 1.1179 h⁻¹), followed by a slower steady decrease after 6 h. After intravenous and intradermal administration, IFN α was rapidly cleared from the serum, t_1/2 0.75 h, k 0.9271 h⁻¹ and t_1/2 1.28 h, k 0.5421 h⁻¹, respectively, whereas after topical application, IFN α levels remained below 100 U/mL. Topical application of BPV- IFN α resulted in sustained delivery of biologically active IFN α locally into skin with minimal systemic exposure.     

Influence of experimentally induced fever on the disposition of cefpirome in buffalo calves

The influence of Escherichia coli endotoxin-induced fever on the disposition of cefpirome was investigated in five male buffalo calves following a single intravenous dose of 10 mg kg⁻¹. Blood samples were collected from 1 min to 24 h of drug administration. The drug concentration in plasma was estimated by microbiological assay using E. coli as a test organism. The disposition of cefpirome followed two-compartment open model and the drug was detected above the minimum inhibitory concentration in plasma up to 12 h. The Vd_area and AUC were 0.75 ± 0.01 L kg⁻¹ and 35.1 ± 0.46 μg ml⁻¹ h, respectively. The elimination half-life of 1.81 ± 0.009 h and Cl_B of 0.29 ± 0.004 L kg⁻¹ h⁻¹ reflected rapid elimination and body clearance of cefpirome in febrile buffalo calves. Based on the results, a satisfactory dosage regimen of cefpirome in febrile buffalo calves was calculated to be 6 mg kg⁻¹ to be repeated at 8 h intervals.     

The oxidative stress response of oxytetracycline in the ciliate Pseudocohnilembus persalinus

Oxytetracycline (OTC) is commonly employed in fish farms to prevent bacterial infections in China, and because of their widely and intensive use, the potential harmful effects on organisms in aquatic environment are of great concern. Ciliates play an important role in aquatic food webs as secondary producers, and Pseudocohnilembus persalinus, is one kind of them which are easily found in fish farms, surviving in polluted water. Therefore, using P. persalinus as experimental models, this study investigated the effects of oxytetracycline (OTC) on the growth, antioxidant system and morphological damage in pollution-resistant ciliates species. Our results showed that the 96-h EC₅₀ values for OTC of P. persalinus was 21.38 mg L⁻¹. The increased level of SOD and GSH during 96 h OTC stress was related to an adaptive response under oxidative stress induced in ciliates. Additionally, sod1, sod2 and sod3 exhibited a significant increased expression level compared to control group at 24 h treatment, indicating a promoting of dense system in ciliates at this exposure time. However, only sod1 and sod2 showed raised expression level at 48 h stress, showing the different sensitive of gene isoforms to some extent. With OTC treatment, damage of regular wrinkles, shrunk, twisted on the cell surface, even forming cyst of scuticociliatid ciliate cells were firstly observed by SEM (scanning electron microscope) in this study. Overall, physiological, molecular and morphological information on the toxicological studies of ciliates and more information on possibility of ciliates as indicators of contamination were provided in this study.     

Silver nanoparticle induced toxicity to human sperm by increasing ROS(reactive oxygen species) production and DNA damage

Silver nanoparticles (AgNPs) have been used in medical products and industrial coatings, due to their antimicrobial properties. Excessive use of AgNPs can have adverse effects on the human body, however, their toxicity characteristics to human sperm and the potential mechanisms are not entirely clear. In this study, we exposed human sperm to different doses of AgNPs (0, 50 μg ml⁻¹, 100 μg ml⁻¹, 200 μg ml⁻¹ or 400 μg ml⁻¹) for various times (15 min, 30 min, or 60 min), followed by analyses of the sperm viability, motility and the ratio of abnormal to normal sperm.Then, transmission electron microscopy(TEM) was used to explore the sperm ultrastructural characteristics. Reactive oxygen species production and DNA fragmentation were tested using standard kits and the sperm chromatin dispersion method, respectively. The results showed a dose- and time-dependent decline in sperm viability and motility and an increased ratio of abnormal to normal sperm after 30 min and 60 min of exposure to AgNPs at 200 μg ml⁻¹ and 400 μg ml⁻¹. The most common abnormalities were sperm heads with disrupted chromatin or absent acrosomes, bent tails, and curved mid-pieces. The ultrastructural characteristics of AgNP-treated sperm included disrupted, swollen, granular and vacuolar defects of the chromatin. In addition, ROS(reactive oxygen species)production and DNA fragmentation were markedly increased after 60 min of exposure to AgNPs at 200 μg ml⁻¹ and 400 μg ml⁻¹. Our results indicated that AgNPs caused detrimental changes in human sperm characteristics, and the excessive use of AgNPs should be carried out with caution.     

Applications in environmental risk assessment of biochemical analysis on the Indian fresh water fish,Labeo rohita exposed to monocrotophos pesticide

Pesticides are widely used in modern agriculture to aid in the production of high quality food. However, some pesticides have the potential to cause serious health and environmental damage. Repeated exposure to sub-lethal doses of pesticides can cause physiological and behavioral changes in fish that reduce populations such as abandonment of nests and broods, decreased immunity to disease and increased failure to avoid predators. Monocrotophos is one of the organophosphorus pesticide used in this study. The median lethal concentration (LC₅₀) of Monocrotophos to fish L. rohita for 96 h was found to be 45.1 ppm. In sublethal concentration (1/10th of LC₅₀ 96 h value, 4.51 ppm) fishes were exposed for 24, 48, 72, 96 h and 10, 20 and 30 days. Organs of fishes were sacrificed and tested for biochemical analysis. A significant decrease in protein, carbohydrate and lipids were observed throughout the study period when compared to the control. It is essential for assessing the ecological risk of these pesticides.     

Benzo(a)pyrene induces interleukin (IL)-6 production and reduces lipid synthesis in human SZ95 sebocytes via the aryl hydrocarbon receptor signaling pathway

In this study, we determined the effects of benzo(a)pyrene (BaP) on the expression of aryl hydrocarbon receptor (AhR) and cytochrome P450 1A1 (CYP1A1), and assessed the action of BaP on inflammatory cytokine expression and lipid synthesis in SZ95 sebocytes in vitro. BaP (10⁻⁸, 10⁻⁷, 10⁻⁶ and 10⁻⁵ M) was not cytotoxic for SZ95 sebocytes after 24 h exposure. Expression of AhR was promoted in mRNA lever, while was inhibited in protein lever after BaP (10⁻⁵ M) exposure. CYP1A1 expression was up-regulated in both mRNA and protein levels. BaP (10⁻⁵ M) exerted a stimulatory action on interleukin (IL)-6 secretion, while a dose-dependently inhibitory effect on lipid synthesis from 10⁻⁸ M to 10⁻⁵ M in SZ95 sebocytes. Both actions were partly antagonized in AhR-knockdowned SZ95 sebocytes. This study demonstrates that BaP can activate AhR signaling pathway, and exhibits pro-inflammatory effects and inhibitory effects on sebum production in human sebocytes.     

Toxicological effects of phenol on four marine microalgae

The toxic effects of phenol on four marine microalgae (Dunaliella salina, Platymonas subcordiformis, Phaeodactylum tricornutum Bohlin, and Skeletonema costatum) were evaluated. The 96 h EC₅₀ values were 72.29, 92.97, 27.32, and 27.32 mg L⁻¹, respectively, which were lower than those values of freshwater microalgae reported in the literature. During a 96-h exposure to a sub-lethal concentration of phenol (1/2 96 h EC₅₀) with green alga (D. salina) and diatom (S. costatum), reactive oxygen species (ROS) accumulation, and chlorophyll a (Chl a) content decrease were simultaneously observed in diatom cells after 48 h treatment. On the contrary, other chlorophylls in both algae were unaffected. Under transmission electron microscopy (TEM), the phenol-induced ultrastructure alterations included disappearance, or shrinkage, of nucleolus and enlargement of vacuoles, which may result in programmed cell death (PCD). The increase in number of lipid droplets may be related to phenol detoxification. These results indicate that the sensitivity of marine microalgae to phenol was dependent on some biotic factors such as cell size, ROS production, and phenol degradation ability in algal cells.     

Subchronic,reproductive, and maternal toxicity studies with tertiary butyl acetate (TBAC)

Tertiary-butyl acetate (TBAC) was tested for subchronic toxicity in rats and mice and reproductive toxicity in rats at inhalation concentrations of 0, 100, 400 or 1600 ppm. An oral maternal toxicity study was conducted in rats at dose levels of 0, 400, 800, 1000 and 1600 mg kg⁻¹ d⁻¹. In the inhalation studies, hematology, clinical chemistry, urinalysis, gross pathology and the majority of body weight and feed consumption values were unaffected. Exposure to TBAC at concentrations of 400 ppm and higher caused transient hyperactivity in mice and some evidence of increased motor activity counts in male rats at the 1600 ppm exposure level. TBAC caused α₂u-globulin accumulation in male rat kidneys from all exposure groups and increased liver weights in 1600 ppm rats and mice. Levels of thyroxin were decreased in male mice exposed to 1600 ppm TBAC for 4 weeks but otherwise thyroid endpoints were unaffected in rats and mice at either the 4 or 13 weeks time points. There was no evidence or immunotoxicity or reproductive toxicity in rats. Pregnant rats receiving 1000 mg kg⁻¹ d⁻¹ TBAC exhibited severe signs of acute neurotoxicity and decreased feed consumption and body weight gain. Fetal viability and growth were unaffected.     

Activity of the enzymes of the antioxidative system in cadmium-treated Oxya chinensis (Orthoptera Acridoidae)

One purpose in this research was to determine the toxic effects of Cd on antioxidant enzymes of Oxya chinensis (Orthoptera: Acridoidae). Changes in the activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPx) were measured in O. chinensis insects injected with Cd²⁺. Fifth-nymphs of O. chinensis insects were injected with Cd²⁺ at different concentrations (0, 0.55 × 10⁻⁴, 1.10 × 10⁻⁴, 1.65 × 10⁻⁴, 2.20 × 10⁻⁴, and 2.75 × 10⁻⁴ g g⁻¹). An increase in SOD activity in O. chinensis was observed at 1.10 × 10⁻⁴ to 2.75 × 10⁻⁴ g g⁻¹ Cd²⁺. The SOD activity was lower at 2.20 × 10⁻⁴and 2.75 × 10⁻⁴ g g⁻¹ than that at 1.10 × 10⁻⁴ and 1.65 × 10⁻⁴ g g⁻¹. It appears that SOD had a positive protective effect at low Cd²⁺ concentrations, and that this effect disappeared at high Cd²⁺ concentrations. CAT activity was accelerated to varying degrees at 1.10 × 10⁻⁴ to 2.75 × 10⁻⁴ g g⁻¹ for males and at 1.10 × 10⁻⁴, 2.20 × 10⁻⁴, and 2.75 × 10⁻⁴g g⁻¹ for females. CAT showed a strong detoxification effect with all treatments. GPx activity decreased with increasing Cd²⁺ concentration with all treatments for males and at 2.20 × 10⁻⁴ and 2.65 × 10⁻⁴g g⁻¹ for females. We showed that GPx activity had a weak detoxification function with all treatments for males and at high Cd²⁺ for females. Thus, CAT had a strong detoxification effect, whereas SOD had a medium and GPx had a weak detoxification effect. Among the three enzymes, CAT played an important role in the damaging mechanisms of reactive oxygen species in O. chinensis insects. Alterations of the antioxidant enzyme level under environmental stresses are suggested as indicators of biotic and abiotic stress.     

Ecotoxicity of veterinary enrofloxacin and ciprofloxacin antibiotics on anuran amphibian larvae

The ecological risks posed by two β-diketone antibiotics (DKAs, enrofloxacin, ENR and ciprofloxacin, CPX), characterized by their long persistence in aqueous environments and known deleterious effect on model organisms such as zebrafish were analysed using Rhinella arenarum larvae. Sublethal tests were conducted using environmentally relevant concentrations of both ENR and CPX (1–1000 μg L⁻¹) under standard laboratory conditions for 96 h. Biological endpoints and biomarkers evaluated were body size, shape, development and growth rates, and antioxidant enzymes (glutathione-S-transferase, GST; Catalase, CAT). Risk assessment was analysed based on ration quotients (RQ). The size and shape measurements of the larvae exposed to concentrations greater than 10 μg L⁻¹ of CPX were lower compared to controls (Dunnett post hoc p < 0.05) and presented signs of emaciation. Concentrations of 1000 μg L⁻¹of CPX induced GST activity, in contrast with inhibited GST and CAT of larvae exposed to ENR. Risk assessments indicated that concentrations greater than or equal to10 μg L⁻¹ of CPX and ENR are ecotoxic for development, growth, detoxifying, and oxidative stress enzymes. It is suggested that additional risk assessments may provide evidence of bioaccumulation of CPX and ENR in tissues or organs of amphibian larvae by mesocosm sediment test conditions. Finally, intestinal microbiome studies should be considered to establish the mechanisms of action of both antibiotics.     

Effects of glyphosate exposure on sperm concentration in rodents: A systematic review and meta-analysis

BackgroundCorrelation between exposure to glyphosate and sperm concentrations is important in reproductive toxicity risk assessment for male reproductive functions. Many studies have focused on reproductive toxicity on glyphosate, however, results are still controversial. We conducted a systematic review of epidemiological studies on the association between glyphosate exposure and sperm concentrations of rodents. The aim of this study is to explore the potential adverse effects of glyphosate on reproductive function of male rodents.MethodsSystematic and comprehensive literature search was performed in MEDLINE, TOXLINE, Embase, WANFANG and CNKI databases with different combinations of glyphosate exposure and sperm concentration. 8 studies were eventually identified and random-effect model was conducted. Heterogeneity among study results was calculated via chi-square tests. Ten independent experimental datasets from these eight studies were acquired to synthesize the random-effect model.ResultsA decrease in sperm concentrations was found with mean difference of sperm concentrations(MDsperm) = −2.774 × 10⁶/sperm/g/testis(95%CI = −0.969 to −4.579) in random-effect model after glyphosate exposure. There was also a significant decrease after fitting the random-effect model: MDsperm = −1.632 × 10⁶/sperm/g/testis (95%CI = −0.662 to −2.601).ConclusionsThe results of meta-analysis support the hypothesis that glyphosate exposure decreased sperm concentration in rodents. Therefore, we conclude that glyphosate is toxic to male rodent’s reproductive system.     

Assessment of fetal exposure risk following seminal excretion of a therapeutic IgG4 (T-IgG4) monoclonal antibody using a rabbit model

Studies were conducted in New Zealand White rabbits to assess the seminal transfer, vaginal absorption, and placental transfer of a therapeutic monoclonal antibody (T-IgG4). T-IgG4 was administered by intravenous injection (IV) in males and by IV and intravaginal routes in females. Low levels of T-IgG4 were excreted into seminal plasma (100- to 370-fold lower than serum concentrations) and absorbed following vaginal dosing (three orders of magnitude lower than IV administration). On gestation day 29 (GD29), fetal serum T-IgG4 levels were 1.5-fold greater than maternal levels following IV dosing. The fetal T-IgG4 exposure ratio for seminal transfer vs. direct maternal IV dosing was estimated to be 1.3 × 10⁻⁸. Applying human serum T-IgG4 exposure data to the model, the estimated human T-IgG4 serum concentration from seminal transfer was 3.07 × 10⁻⁷ μg/mL, an exposure level at least 1000-fold lower than the T-IgG4-ligand dissociation constant (K_d) and at least seven orders of magnitude lower than the in vivo concentration producing 20% inhibition of the target (EC₂₀). These data indicate that excretion of a T-IgG4 into semen would not result in a biologically meaningful exposure risk to the conceptus of an untreated partner.     

Distribution,fate and histopathological effects of ethion insecticide on selected organs of the crayfish,Procambarus clarkii

This study aims to investigate the fate and histopathological effects of ethion on selected organs of the crayfish, Procamabrus clarkii. Crayfish were exposed to 1 mg l^{−1 14}C-ethion and the concentrations of ethion and its possible degradation products were measured in water and different organs of the crayfish over both the exposure and recovery periods. Chromatographic analysis revealed that ethion was degraded into ethion monooxon, ethion dioxon, O,O-diethyl phosphorothioate, O-ethyl phosphorothioate and one unknown compound. At the end of exposure period, ethion was accumulated in different organs of the crayfish especially in the hepatopancreas and gills. Following the transfer of crayfish to clean water for seven days, the concentration of insecticide residues were decreased in both the hepatopancreas and gills suggesting that these organs play an important role in elimination of ethion. On the other hand, the exposure of the crayfish to ¼ 96 h-LC₅₀ (0.36 mg l⁻¹) of ethion caused extensive ultrastructural alterations to both hepatopancreas and gill epithelial cells. In the hepatopancreas, the most notable pathological features included vacuolation, degradation and distinct cell lysis. In the gill epithelium, the histopathological alterations included infiltration of hemocytes, cytoplasmic vacuolation and a decrease in the number of basal plasma membrane infoldings.