First report of saxitoxin in Finnish lakes and possible associated effects on human health

This study is the first report of saxitoxin in cyanobacterial blooms in Finland. Bloom samples (n = 50) were collected from Finnish freshwater sites during summer months of 2002 and 2003. These samples were screened for the presence of paralytic shellfish toxins (PSTs) using the Jellett rapid PSP screening test. Samples testing positive for PSTs (n = 7) were further analyzed with saxiphilin- and voltage-gated sodium channel [(3)H]-STX-binding radioreceptor assays and liquid chromatography using fluorescence and mass spectrometric analysis. The results indicated that saxitoxin (STX) was the only PST analogue in the samples and that it was present in high concentrations, as much as 1 mg L(-1). Microscopic analysis revealed that 95%-100% of the phytoplankton in the positive samples consisted of Anabaena lemmermannii. The trophic status of lakes in which STX-containing blooms were found varied from oligotrophic to hypertrophic. All the lakes had high nitrogen-to-phosphorus ratios. In some instances, samples had been collected from sites where swimmers had reported adverse health effects, and in three such cases, reported adverse health effects were associated with sites from which samples testing positive for STX had been received. Symptoms of fever, eye irritation, abdominal pains, and skin rash were reported in children aged 2-10 years after exposure to the water. These were not the adverse human symptoms typical of STX poisoning; rather, they represented acute effects often reported following recreational exposure to cyanobacterial blooms.     

Motion detection and correction for dynamic 15O-water myocardial perfusion PET studies

Purpose Patient motion during dynamic PET studies is a well-documented source of errors. The purpose of this study was to investigate the incidence of frame-to-frame motion in dynamic ¹⁵O-water myocardial perfusion PET studies, to test the efficacy of motion correction methods and to study whether implementation of motion correction would have an impact on the perfusion results.Methods We developed a motion detection procedure using external radioactive skin markers and frame-to-frame alignment. To evaluate motion, marker coordinates inside the field of view were determined in each frame for each study. The highest number of frames with identical spatial coordinates during the study were defined as non-moved. Movement was considered present if even one marker changed position, by one pixel/frame compared with reference, in one axis, and such frames were defined as moved. We tested manual, in-house-developed motion correction software and an automatic motion correction using a rigid body point model implemented in MIPAV (Medical Image Processing, Analysis and Visualisation) software. After motion correction, remaining motion was re-analysed. Myocardial blood flow (MBF) values were calculated for both non-corrected and motion-corrected datasets.Results At rest, patient motion was found in 18% of the frames, but during pharmacological stress the fraction increased to 45% and during physical exercise it rose to 80%. Both motion correction algorithms significantly decreased (p<0.006) the number of moved frames and the amplitude of motion (p<0.04). Motion correction significantly increased MBF results during bicycle exercise (p<0.02). At rest or during adenosine infusion, the motion correction had no significant effects on MBF values.Conclusion Significant motion is a common phenomenon in dynamic cardiac studies during adenosine infusion but especially during exercise. Applying motion correction for the data acquired during exercise clearly changed the MBF results, indicating that motion correction is required for these studies.     

Automatic speaking valve in speech rehabilitation for laryngectomized patients

For speech rehabilitation after total laryngectomy, the Provox FreeHands Heat and Moisture Exchanger (FreeHands HME; Atos Medical AB, Hörby, Sweden) was compared with the Provox Heat and Moisture Exchanger (HME), and the patients Health-Related Quality of Life (HRQoL) was assessed. A review of the English literature was performed considering automatic speaking valves. The study design was a cohort study. Fourteen laryngectomized male patients who had used the HME successfully before receiving the FreeHands HME entered the study. An ENT specialist and a speech pathologist examined these patients. Data concerning voicing, breathing, skin adhesion, voice and speech quality, and HRQoL were collected by a structured questionnaire. Voice recordings were performed for evaluation of the quality of the voice. A computer-aided search of the MED-LINE database was conducted, supplemented by hand searches of key journals. Twelve patients had used the FreeHands HME on special social occasions and reported three main reasons why FreeHands HME was unsuitable for continuous use: heavier breathing, more difficult speaking, and worse subjective quality of voice. With HME, phonation time tended to be longer and the softest phonation softer ( P =0.034). The loudest phonation was louder with FreeHands HME ( P =0.015). Patients HRQoL assessed by the 15D profile was similar to that of the age- and sex-matched male Finnish general population (patients 0.877, population 0.884). A review of the literature showed few works dealing with automatic speaking valves. The FreeHands HME is a useful additional device in a selected group of laryngectomized patients. Total laryngectomy did not lower patients HRQoL notably.Some of these data were presented at the 16th Annual Meeting of the Scandinavian Society for Head and Neck Oncology, 24 April 2004, in Oulu, Finland.     

Association of serum lipid concentrations, insulin resistance index and catch-up growth with serum cortisol/cortisone ratio by liquid chromatography tandem mass spectrometry in children born small for gestational age

Intrauterine growth restriction (IUGR) may influence adrenocortical function, lipid metabolism and glucose tolerance in later life. Both cortisol (F) synthesis and metabolism contribute to serum F concentrations. 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) enzyme converts F to biologically inactive cortisone (E). Decreased 11beta-HSD2 activity has been suggested for a reason to IUGR and to its metabolic consequences. Our aim was to develop a specific liquid chromatography - tandem mass spectrometry (LC-MS/MS) method for analysing serum F and E concentrations, to determine the F/E ratios, and to correlate them with serum lipid concentrations, insulin resistance index (HOMA-IR), and catch-up growth in children born small for gestational age (SGA). The mean serum F and E concentrations, and F/E ratios did not differ between the SGA and their control children at 12 y age. The SGA children in the highest F/E ratio quartile had poorer gain in height between 0-12 y, and higher serum total and LDL cholesterol levels than those with lower F/E ratios. In logistic regression analysis, high LDL cholesterol, high HOMA-IR, and early pubertal stage associated with high F/E ratio in the SGA children. In conclusion, our LC-MS/MS method enables a reliable measurement of both F and E concentrations from a single serum sample. High serum F/E ratio may be associated with IUGR, its metabolic consequences, and poor catch-up growth in a subset of SGA children.