The course of toxicity in the pregnant mouse after exposure to the cyanobacterial toxin cylindrospermopsin: clinical effects, serum chemistries, hematology, and histopathology

Cylindrospermopsin (CYN) is a toxin produced by a variety of fresh-water cyanobacterial species worldwide and induces significant adverse effects in both livestock and humans. This study investigated the course of CYN-induced toxicity in pregnant mice exposed daily during either the period of major organogenesis (gestation days [GD] 8-12) or fetal growth (GD13-17). Endpoints include clinical signs of toxicity, serum analyses to evaluate hepatic and renal function, histopathology of liver and kidney, and hematology. Study animals were administered 50 μg/kg CYN once daily by ip route and euthanized 24 h after 1, 2, 3, 4, or 5 consecutive doses, or 6 or 13 d after the dosing period. The course of the CYN-induced effects was determined at all euthanasia times for the endpoints just outlined. Results indicated that CYN is a toxin, producing lethality in dams during the early part of gestation, significant weight loss, and bleeding in the gastrointestinal tract, tail tip, and peri-orbital tissues. Effects also included alterations in serum markers for liver function, histopathological changes in liver and kidney tissues, electrolyte abnormalities, leukocytosis, and posttreatment thrombocytopenia and reticulocytosis. The onset of symptoms was rapid, producing reductions in weight gain in GD8-12 animals, bleeding in the vaginal area in GD13-17 animals, and significant increases in sorbitol dehydrogenase (SDH) in both groups after a single dose. Although the GD8-12 dams displayed a 50% lethality, in GD13-17 animals only a single death occurred. Alterations seen in hepatic and renal function or histopathology do not appear to be of sufficient severity to produce death. Evidence indicates that bleeding may play a critical role in the onset of symptoms and eventually, in the observed lethality.

Toxicity and recovery in the pregnant mouse after gestational exposure to the cyanobacterial toxin, cylindrospermopsin

Cylindrospermopsin (CYN) is a tricyclic alkaloid toxin produced by fresh water cyanobacterial species worldwide. CYN has been responsible for both livestock and human poisoning after oral exposure. This study investigated the toxicity of CYN to pregnant mice exposed during different segments of gestation. The course of recovery and individual responses to the toxin were evaluated. Adverse effects of CYN were monitored up to 7 weeks post-dosing by clinical examination, histopathology, biochemistry and gene expression. Exposure on gestational days (GD) 8-12 induced significantly more lethality than GD13-17 exposure. Periorbital, gastrointestinal and distal tail hemorrhages were seen in both groups. Serum markers indicative of hepatic injury (alanine amino transferase, aspartate amino transferase and sorbitol dehydrogenase) were increased in both groups; markers of renal dysfunction (blood urea nitrogen and creatinine) were elevated in the GD8-12 animals. Histopathology was observed in the liver (centrilobular necrosis) and kidney (interstitial inflammation) in groups exhibiting abnormal serum markers. The expression profiles of genes involved in ribosomal biogenesis, xenobiotic and lipid metabolism, inflammatory response and oxidative stress were altered 24 h after the final dose. One week after dosing, gross, histological and serum parameters had returned to normal, although increased liver/body weight ratio and one instance of gastrointestinal bleeding was found in the GD13-17 group. Gene expression changes persisted up to 2 weeks post-dosing and returned to normal by 4 weeks. Responses of individual animals to CYN exposure indicated highly significant inter-animal variability within the treated groups.

The cyanobacterial toxin, cylindrospermopsin, induces fetal toxicity in the mouse after exposure late in gestation

Cylindrospermopsin (cyn) is a cyanobacterial toxin implicated in human and wildlife poisonings. We have completed studies investigating the potential of purified cyn to induce developmental toxicity in mammals. The teratology study involved intraperitoneal injections (8.0-128 microg kg(-1)) on gestational days (GD) 8-12 with subsequent examination of term fetuses for viability, weight and morphological anomalies. Cyn was lethal to a significant portion of the dams receiving > or = 32 microg kg(-1). Surviving pregnant females were killed and fetuses removed for examination. Analysis indicates no adverse effects on litter size, fetal weight, or incidence of anomalies. Subsequently, 50 microg kg(-1) cyn was administered on GD 8-12 or 13-17. Animals were allowed to give birth and litters monitored for growth and viability. A reduction in litter size occurred in treated groups. Avg. pup wt. was only affected in the GD 13-17 group. GD 13-17 dams did not exhibit the toxicity noted in the GD 8-12 group but gave birth significantly earlier than controls. There was a significant number of dead GD 13-17 pups and incidences of blood in the gastrointestinal tract and hematomas in the tips of the tails in survivors. Pups were cross-fostered to control mothers in litters of 10. On postnatal days (PND) 5-6 there were no significant differences in weight gain or viability in GD 8-12 litters, while GD 13-17 litters had significantly reduced weight gain and viability. GD 13-17 exposed male pups still weighed significantly less than the controls after 15 months.

Round atelectasis in an elderly man: the role of thoracotomy

In summary, a case of round atelectasis appearing subsequent to a pleural effusion in an elderly man 6 months after open heart surgery is reported. Although plain roentgenograms and linear and computerized tomography could help the physician make the diagnosis with confidence, a needle biopsy of the lesion at the very least or exploratory thoracotomy may sometimes still be justified for the properly selected patient.

Mass spectrometric analyses and characterization of Kepone in environmental and human samples

A specific portion of our environment has been contaminated with Kepone, or chlordecone. Additionally, some specific human exposures to high concentrations of Kepone have been confirmed. Gas chromatography mass spectrometry involving chemical ionization and high resolution mass spectrometry were used to detect, identify and confirm the presence of Kepone, Kepone photoproducts and a reduction product of Kepone in environmental and human samples. Field desorption, field ionization and electron impact mass spectrometric methods, as well as infrared and nuclear magnetic resonance techniques were used to characterize and identify Kepone hydrate and hemiketal in benzene and methanol solutions, respectively.