Isolation and characterization of toxins from the phytoflagellate Prymnesium parvum

Toxic strains of Prymnesium parvum were isolated from fish ponds with blooms of a toxigenic flagellate P. parvum and high fish mortality. The pure culture was successfully achieved in laboratory. Culture of P. parvum grew well in medium of artificial sea water medium (Salinity, 12-16 permill ) and natural sea water at 23 degree C and 600-800 1x illumination. Haemolytic activity appeared during the stationary phase of the exponential growth phase and maximized at the latter stationary phase. Two kinds of toxins, i. e. hemolysin and ichthyotoxin were extracted from Prymnesium cells as well as from extracellular medium. The activity of P. parivum haemolysin and ichthyotoxin was detected respectively using bovine erythrocytes and Poecilia reticulata. The dependence of P. parvum ichthyotoxin on various co-factors was also studied. The major component of a homolysin was identified being a glycolipid

Seven microcystins from Microcystis waterbloom in Lake Dalai, China

Seven types of microcystins, isolated from Microcystis waterbloom in Lake Dalai, were characterized. The major toxins: MCYST-LR, MCYST-RR, (D-Asp-3) MCYST-LR and (Dha-7) MCYST-LR were identified by high performance liquid chromatography (HPLC), as compared with the authentic microcystins. The minor toxins: MCYST FR, CL-Mser-7) MCYST-LR and an unknown MCYST which was most likely to be MCYST-(H-4) YR were identified with fritfast atom bombardment liquid chromatography/mass spectrometry (Frit-FAB LC/MS) and amino acid analysis. The toxigenic diversity in blue-green algae (cyanobacteria) was discussed

Postoperative Cognitive Dysfunction is Correlated with Urine Formaldehyde in Elderly Noncardiac Surgical Patients

Post-operative cognitive dysfunction (POCD), especially in elderly patients, has been reported in many studies. Although increasing age, duration of anesthesia, postoperative infections, and respiratory complications were regarded as the risk factors for POCD, no extracerebral diagnostic biomarkers have been identified as indicators of POCD. Ninety-five patients, ages 65-80 years, scheduled for major orthopedic or abdominal surgery were enrolled. Twenty-two patients aged between 20 and 40 years undergoing the same procedures served as controls. Subjects received neuropsychological tests one-day prior and one week post procedure. To determine the presence of POCD, the criteria were used as described in most previous studies. Morning urine samples were obtained one day before surgery and on day 1, day 2 and day 7 post operatively. Urine formaldehyde was determined with high-performance liquid chromatography. The urine formaldehyde level of all patients with and without POCD increased on the first 2 days after surgery. But the formaldehyde concentration (on day 7) in patients with POCD was significantly higher than that in patients without POCD (p < 0.01). In the young control group, no patient was diagnosed with POCD. Although the changes in urine formaldehyde of young patients during perioperative period were similar to those in elderly patients without POCD, the formaldehyde concentrations measured at four time points were all significantly lower than those in elderly patients (p < 0.05). Levels of urine formaldehyde were elevated in the perioperative period, with the highest levels at day 7 in patients with POCD. This suggests that the increase on day 7 may provide a new physiologic marker along with neuropsychological assessments to assist in the diagnosis of POCD