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1.
Epidemiol Infect ; 144(13): 2732-42, 2016 Oct.
Article in English | MEDLINE | ID: mdl-26493730

ABSTRACT

During one week in July 2012, two patients from the same ward at the municipal hospital in Vaasa, Finland, were diagnosed with septicaemia caused by Listeria monocytogenes. An outbreak investigation revealed eight concomitant cases of febrile gastroenteritis caused by L. monocytogenes on the same ward. Median age of the cases was 82 years and median incubation time for listerial gastroenteritis was 21 h (range 9-107). An additional 10 cases of invasive listeriosis caused by the same outbreak strain were identified across the whole country during the summer of 2012. Environmental investigation at the affected municipal hospital ward revealed ready-sliced meat jelly as the suspected source of the infection. During inspection of the meat jelly production plant, one pooled sample taken from a floor drain and a trolley wheel in the food processing environment was positive for the outbreak strain of L. monocytogenes. After the producer stopped the production of meat jelly, no further cases of listeriosis with the outbreak strain were identified via nationwide surveillance.


Subject(s)
Cross Infection/microbiology , Food Microbiology , Foodborne Diseases/microbiology , Gastroenteritis/microbiology , Listeria monocytogenes/isolation & purification , Listeriosis/microbiology , Meat Products/microbiology , Aged , Aged, 80 and over , Animals , Female , Finland , Gelatin/analysis , Humans , Male , Middle Aged
2.
Diabetologia ; 53(8): 1709-13, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20454776

ABSTRACT

AIMS/HYPOTHESIS: We studied the impact of a family history of type 2 diabetes on physical fitness, lifestyle factors and diabetes-related metabolic factors. METHODS: The Prevalence, Prediction and Prevention of Diabetes (PPP)-Botnia study is a population-based study in Western Finland, which includes a random sample of 5,208 individuals aged 18 to 75 years identified through the national Finnish Population Registry. Physical activity, dietary habits and family history of type 2 diabetes were assessed by questionnaires and physical fitness by a validated 2 km walking test. Insulin secretion and action were assessed based upon OGTT measurements of insulin and glucose. RESULTS: A family history of type 2 diabetes was associated with a 2.4-fold risk of diabetes and lower physical fitness (maximal aerobic capacity 29.2 +/- 7.2 vs 32.1 +/- 7.0, p = 0.01) despite having similar reported physical activity to that of individuals with no family history. The same individuals also had reduced insulin secretion adjusted for insulin resistance, i.e. disposition index (p < 0.001) despite having higher BMI (27.4 +/- 4.6 vs 26.0 +/- 4.3 kg/m(2), p < 0.001). CONCLUSIONS/INTERPRETATION: Individuals with a family history of type 2 diabetes are characterised by lower physical fitness, which cannot solely be explained by lower physical activity. They also have an impaired capacity of beta cells to compensate for an increase in insulin resistance imposed by an increase in BMI. These defects should be important targets for interventions aiming at preventing type 2 diabetes in individuals with inherited susceptibility to the disease.


Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Life Style , Physical Fitness/physiology , Adolescent , Adult , Aged , Blood Glucose/metabolism , Body Composition , Diabetes Mellitus, Type 2/metabolism , Family , Female , Finland , Genetic Predisposition to Disease , Humans , Insulin Resistance , Insulin-Secreting Cells/metabolism , Male , Middle Aged , Prevalence , Registries , Regression Analysis , Risk Factors , Sex Factors , Surveys and Questionnaires
3.
Water Sci Technol ; 54(3): 23-8, 2006.
Article in English | MEDLINE | ID: mdl-17037128

ABSTRACT

The removal of cyanobacteria, hepatotoxins produced by them (microcystins), phytoplankton, heterotrophic bacteria and endotoxins were monitored at a surface water treatment plant with coagulation, clarification, sand filtration, ozonation, slow sand filtration and chlorination as the treatment process. Coagulation-sand filtration reduced microcystins by 1.2-2.4, and endotoxins by 0.72-2.01 log10 units. Ozonation effectively removed the residual microcystins. The treatment process reduced phytoplankton biomass by 2.2-4.6 and heterotrophic bacteria by 2.0-5.0 log10 units. In treated water, the concentration of microcystins never exceeded the WHO guide value (1 microg/L), but picoplankton and monad cells were often detected in high numbers. The heterotrophic bacterial isolates from the treated waters belonged to genera Sphingomonas, Pseudomonas, Bacillus, Herbaspirillum and Bosea.


Subject(s)
Bacteria/isolation & purification , Cyanobacteria/isolation & purification , Endotoxins/isolation & purification , Water Microbiology , Water Supply , Bacteria/classification , Species Specificity
4.
Amino Acids ; 28(3): 327-35, 2005 May.
Article in English | MEDLINE | ID: mdl-15789141

ABSTRACT

This study was designed to determine the responses of muscle protein, serum amino acids, and strength performance to bovine colostrum supplementation in physically active men. The rest (R) group (n = 6) and the exercise (E) group (n = 6) carried out twice a 2-week experiment randomly assigned in a double-blind fashion with either placebo (PLA; consuming daily 20 g maltodextrin) or bovine colostrum (COL; consuming daily 20 g colostrum supplement) treatment with one month between. On the test day after the treatment period the measurements were carried out in fasting conditions and E carried out a strength training session (STS). The methods involved the infusion of ring-(2)H(5)-phenylalanine, femoral arterial and venous blood sampling, and biopsies from the vastus lateralis muscle. Serum concentration of essential amino acids during recovery was greater (p < 0.05) in the COL groups compared with the PLA groups. Both muscle protein synthesis and breakdown increased (p < 0.05) with COL. There were no differences in phenylalanine net balance or strength performance between the PLA and COL groups. It was concluded that a 2-week supplementation with bovine colostrum in physically active men increases serum concentration of essential amino acids but has no effect either on strength performance or protein net balance in fasting conditions during recovery after STS.


Subject(s)
Amino Acids/blood , Colostrum , Dietary Supplements , Fasting/blood , Muscle Proteins/biosynthesis , Protein Biosynthesis/drug effects , Adult , Animals , Cattle , Humans , Male , Physical Fitness/physiology , Quadriceps Muscle/metabolism
5.
Water Sci Technol ; 50(1): 155-8, 2004.
Article in English | MEDLINE | ID: mdl-15318502

ABSTRACT

Artificial recharge of groundwater offers a semi-natural means to produce raw water for drinking-water plants. Surface water works are increasingly being replaced by artificial groundwater works in Finland. Two municipalities, one serving 30,000 and the other 170,000 inhabitants, have considered filtering river water through eskers for the production of potable water. In this study the removal of bacteriophages during infiltration of river water was estimated, for the evaluation of treatment adequacy in a field study. A 5-m-deep column of sand was constructed and used to mimic the percolating phase in infiltration. An artificial esker was constructed on the riverbank by isolating a 2-m-wide, 2-m-deep and 18-m-long bed of coarse sand with plastic. The sand bed represented the saturated zone. River water was pumped at a rate of 40 L/h to the sand column. The river water was spiked with F+ specific RNA phage MS2 by adding phage suspension during one week at an average concentration of 4.3 x 10(9) PFU/mL. Samples for phage assays were taken during one month, from four sampling sites, on the basis of detention time as estimated by a tracer experiment with sodium chloride. The median count of MS2 for percolated water was 2.4 x 10(5) PFU/mL, representing a 96.7% reduction. During the passage of 6 m in the saturated zone, a further reduction of 98.5% occurred. During the passage from 6 m to 12 m the additional reduction was 99.97%. The overall reduction was between 6 and 7 log10 units. The removal of MS2 phages was rather efficient, although the esker material was coarse, mainly sandy, gravel.


Subject(s)
RNA Phages/isolation & purification , Waste Disposal, Fluid/methods , Water Purification/methods , Filtration , Finland , Rivers , Soil
6.
Water Sci Technol ; 50(1): 179-83, 2004.
Article in English | MEDLINE | ID: mdl-15318506

ABSTRACT

A test was performed to evaluate the microbial and chemical purification capacity of nine portable, small-scale water purification filter devices with production capacity less than 100 L/h. The devices were tested for simultaneous removal capacity of bacteria (cultured Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae and Enterobacter cloacae), enteric protozoans (formalin-stored Cryptosporidium parvum oocysts), viral markers (F-RNA bacteriophages) and microcystins produced by toxic cyanobacterial cultures. In general, the devices tested were able to remove bacterial contaminants by 3.6-6.9 log10 units from raw water. Those devices based only on filtration through pores 0.2-0.4 microm or larger failed in viral and chemical purification. Only one device, based on reverse osmosis, was capable of removing F-RNA phages at concentrations under the detection limit and microcystins by 2.5 log10. The present study emphasised the need for evaluation tests of water purification devices from the public safety and HACCP (Hazard Analysis and Critical Control Point) points of view. Simultaneous testing for various pathogenic/indicator microbes and microcystins was shown to be a useful and practical way to obtain essential data on actual purification capacity of commercial small-scale drinking-water filters.


Subject(s)
Water Purification/instrumentation , Animals , Bacteria/isolation & purification , Cryptosporidium/isolation & purification , Oocysts , Osmosis , RNA Phages/isolation & purification , Water Microbiology
7.
Environ Toxicol ; 16(4): 330-6, 2001.
Article in English | MEDLINE | ID: mdl-11501282

ABSTRACT

There is only limited information about the accumulation of algal toxins in aquatic organisms in the Baltic Sea. In this study we measured total cyanobacterial hepatotoxin levels in blue mussel (Mytilus edulis) and flounderi (Platichthys flesus) tissues. Flounder were caught with gillnets from the western Gulf of Finland during July and August 1999. Blue mussels were collected from an enclosure at 3 m depth and from an artificial reef (wreck, 25-35 m depth) in the western Gulf of Finland between June and September 1999. Flounder liver and muscle samples and soft tissues of mussels were analyzed for the cyanobacterial hepatotoxins (nodularin, NODLN and/or microcystins, MCs) using an enzyme-linked immunosorbent assay (ELISA). Results showed a time-dependent accumulation of hepatotoxins in flounder and mussels. In flounder, the maximum concentration 399 +/- 5 (sd) ng NODLN or MC/g dry weight (dw) was found in the liver of specimens caught on 21 August 1999. No hepatotoxins were detected in muscle samples. The maximum concentration of 2150 ng +/- 60 (sd) ng hepatotoxin/g dw was found in the mussel soft tissues collected on 20 August 1999. Temporal NODLN or MC trends indicated depuration of cyanobacterial hepatotoxin from mussels at surface level and an increase in NODLN or MC concentrations in those from the sea bed. These studies showed that despite the low cyanobacteria cell numbers the cyanobacterial hepatotoxins can accumulate in flounder and mussels. This may allow the further transfer of cyanobacterial hepatotoxins in the food web.


Subject(s)
Bivalvia/physiology , Cyanobacteria/chemistry , Flounder/physiology , Peptides, Cyclic/pharmacokinetics , Animals , Body Weight , Enzyme-Linked Immunosorbent Assay , Kinetics , Liver/chemistry , Microcystins , Muscle, Skeletal/chemistry , Peptides, Cyclic/analysis , Seasons , Tissue Distribution
8.
Water Sci Technol ; 43(12): 225-8, 2001.
Article in English | MEDLINE | ID: mdl-11464762

ABSTRACT

Problems caused by cyanobacteria are common around the world and also in raw water sources of drinking water treatment plants. Strains belonging to genera Microcystis, Anabaena and Planktothrix produce potent hepatotoxins, the microcystins. Laboratory and pilot scale studies have shown that microcystins dissolved in water may pass the conventional surface water treatment processes. In 1998 the World Health Organization proposed a guide value of 1 microgram/L for microcystin-LR (MC-LR) in drinking water. The purpose of this research was to study the occurrence of microcystins in raw water sources of surface waterworks and in bank filtration plants and to evaluate the removal of microcystins in operating waterworks. Four bank filtration plants and nine surface waterworks using different processes for water treatment were monitored. Phytoplankton was identified and quantified, and microcystins analysed with sensitive immunoassay. Microcystin occurrence in selected water samples was verified with HPLC and a protein phosphatase inhibition method. Microcystins were detected sporadically in raw water sources of most of the waterworks. In two raw water supplies toxins were detected for several months. The highest microcystin concentrations in incoming raw water were approximately 10 micrograms/L MC-LR equivalents. In treated drinking water microcystins were detected occasionally but the concentrations were always below the guide value proposed by WHO.


Subject(s)
Peptides, Cyclic/analysis , Water Purification/methods , Water Supply , Chromatography, High Pressure Liquid , Environmental Monitoring , Filtration , Finland , Humans , Microcystins
9.
J Appl Microbiol ; 90(6): 850-8, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11412314

ABSTRACT

AIMS: Enumeration of coliform bacteria and Escherichia coli is the most widely used method in the estimation of hygienic quality of drinking water. The yield of target bacteria and the species composition of different populations of coliform bacteria may depend on the method.Three methods were compared. METHODS AND RESULTS: Three membrane filtration methods were used for the enumeration of coliform bacteria in shallow well waters. The yield of confirmed coliform bacteria was highest on Differential Coliform agar, followed by LES Endo agar. Differential Coliform agar had the highest proportion of typical colonies, of which 74% were confirmed as belonging to the Enterobacteriaceae. Of the typical colonies on Lactose Tergitol 7 TTC agar, 75% were confirmed as Enterobacteriaceae, whereas 92% of typical colonies on LES Endo agar belonged to the Enterobacteriaceae. LES Endo agar yielded many Serratia strains, Lactose Tergitol 7 TTC agar yielded numerous strains of Rahnella aquatilis and Enterobacter, whereas Differential Coliform agar yielded the widest range of species. CONCLUSION: The yield of coliform bacteria varied between methods. Each method compared had a characteristic species distribution of target bacteria and a typical level of interference of non-target bacteria. Identification with routine physiological tests to distinct species was hampered by the slight differences between species. High yield and sufficient selectivity are difficult to achieve simultaneously, especially if the target group is diverse. SIGNIFICANCE AND IMPACT OF THE STUDY: The results showed that several aspects of method performance should be considered, and that the target group must be distinctly defined to enable method comparisons.


Subject(s)
Bacteriological Techniques , Enterobacteriaceae/classification , Enterobacteriaceae/isolation & purification , Water Microbiology , Water Supply , Bacterial Typing Techniques , Colony Count, Microbial , Drinking , Reference Standards , Reproducibility of Results , Specimen Handling
10.
MAGMA ; 12(2-3): 88-91, 2001 May.
Article in English | MEDLINE | ID: mdl-11390261

ABSTRACT

Preliminary results on MS-325 versus ProHance enhanced magnetic resonance angiography (MRA) at low field strength in a rabbit model are reported. MS-325-enhanced images were acquired in vivo and compared with pre-contrast as well as conventional contrast-enhanced images. Visual image quality observations correlated with measurements of signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). While published in vitro data show 7-fold greater relaxivity for MS-325 compared with conventional contrast agents, we observed an even greater effect here due, presumably, to better matching of the longer vascular lifetime with longer scan time in this study. In addition, overall vessel clarity improved significantly throughout all the phases of the experiment in MS-325-enhanced images when compared with conventional contrast-enhanced images.


Subject(s)
Magnetic Resonance Angiography/instrumentation , Abdomen , Animals , Blood Vessels/anatomy & histology , Contrast Media , Magnetic Resonance Angiography/methods , Models, Animal , Rabbits , Reproducibility of Results , Sensitivity and Specificity
11.
Environ Toxicol ; 16(2): 121-6, 2001.
Article in English | MEDLINE | ID: mdl-11339711

ABSTRACT

The brackish water cyanobacterium Nodularia spumigena regularly forms waterblooms in the Baltic Sea. Many N. spumigena strains can produce nodularin, a hepatotoxic penta-peptide, which has caused several animal poisonings in the Baltic Sea area. To improve our understanding of nodularin bioaccumulation in aquatic organisms this study measured nodularin in flounder and cod caught from the Baltic Sea. Flounders were collected from the western Gulf of Finland in July 1996, September 1997, and September 1998, and from the Gulf of Bothnia in August 1997 and September 1998. Flounders were also collected from the coastal areas of Sweden in the Baltic Proper during September 1998. Cod were caught from the southern Baltic Sea in August 1998. Livers and muscles of the 1997 fish were isolated, extracted, and analysed for nodularin using high-performance liquid chromatography (HPLC) and enzyme-linked immunosorbent assay (ELISA) and protein phosphatase 1 (PP1) inhibition assay. Approximately 30-70 ng of nodularin/g dry weight (maximum value 140 ng/g) were found in the liver tissue samples by ELISA and PP1 inhibition. These concentrations were below the detection limit of HPLC. PP1 assay showed inhibition also in muscle samples, but this may due to other compounds present in the muscle extracts rather than NODLN or due to matrix interference. The recovery of nodularin from liver tissue with ELISA and PP1 assays was about 30%. Nodularin concentrations in samples are not corrected for recovery. Although the concentrations of nodularin found in this study are low further studies of nodularin are needed to assess possible bioaccumulation in brackish water food webs.


Subject(s)
Cyanobacteria , Environmental Monitoring , Fishes , Marine Toxins/analysis , Peptides, Cyclic/analysis , Water Pollution , Animals , Chromatography, High Pressure Liquid , Enzyme-Linked Immunosorbent Assay , Finland , Seawater
12.
Diabetes Care ; 24(4): 683-9, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11315831

ABSTRACT

OBJECTIVE: To estimate the prevalence of and the cardiovascular risk associated with the metabolic syndrome using the new definition proposed by the World Health Organization RESEARCH DESIGN AND METHODS: A total of 4,483 subjects aged 35-70 years participating in a large family study of type 2 diabetes in Finland and Sweden (the Botnia study) were included in the analysis of cardiovascular risk associated with the metabolic syndrome. In subjects who had type 2 diabetes (n = 1,697), impaired fasting glucose (IFG)/impaired glucose tolerance (IGT) (n = 798) or insulin-resistance with normal glucose tolerance (NGT) (n = 1,988), the metabolic syndrome was defined as presence of at least two of the following risk factors: obesity, hypertension, dyslipidemia, or microalbuminuria. Cardiovascular mortality was assessed in 3,606 subjects with a median follow-up of 6.9 years. RESULTS: In women and men, respectively, the metabolic syndrome was seen in 10 and 15% of subjects with NGT, 42 and 64% of those with IFG/IGT, and 78 and 84% of those with type 2 diabetes. The risk for coronary heart disease and stroke was increased threefold in subjects with the syndrome (P < 0.001). Cardiovascular mortality was markedly increased in subjects with the metabolic syndrome (12.0 vs. 2.2%, P < 0.001). Of the individual components of the metabolic syndrome, microalbuminuria conferred the strongest risk of cardiovascular death (RR 2.80; P = 0.002). CONCLUSIONS: The WHO definition of the metabolic syndrome identifies subjects with increased cardiovascular morbidity and mortality and offers a tool for comparison of results from diferent studies.


Subject(s)
Cardiovascular Diseases/epidemiology , Diabetes Mellitus, Type 2/epidemiology , Insulin Resistance/physiology , Adult , Age Factors , Aged , Albuminuria/epidemiology , Blood Glucose/metabolism , Cardiovascular Diseases/mortality , Cholesterol/blood , Cholesterol, HDL/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/complications , Family , Female , Finland/epidemiology , Glucose Intolerance/blood , Glucose Intolerance/complications , Glucose Intolerance/epidemiology , Glycated Hemoglobin/analysis , Humans , Hyperlipidemias/blood , Hypertension/epidemiology , Male , Middle Aged , Morbidity , Obesity/epidemiology , Prevalence , Risk Factors , Sex Factors , Sweden/epidemiology , Triglycerides/blood
13.
Magn Reson Med ; 41(2): 412-6, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10080292

ABSTRACT

Changes in cortical activity during foot shock were assessed under conscious and propofol-anesthetized conditions using functional magnetic resonance imaging (fMRI). Increases in signal intensity were observed in the contralateral somatosensory cortex in response to electrical shock of the hindpaw under both conditions. These increases in cortical signal ranged from 6% to 26% while awake and from 1% to 6% under propofol anesthesia. In each of the six animals studied, the largest increase in blood oxygenation level-dependent (BOLD)-based signal intensity was observed during consciousness. In three of six animals, propofol anesthesia depressed signal intensity by as much as 10-fold, showing that the level of cortical activity during foot shock is dampened by anesthesia. These results indicate it would be advantageous to use fully conscious animals to maximize BOLD-based MRI signal in certain behavioral studies using MR spectrometers with modest field strengths (1.0-2.0 T).


Subject(s)
Anesthesia, General , Cerebrovascular Circulation , Consciousness/physiology , Evoked Potentials, Somatosensory , Magnetic Resonance Imaging , Oxygen/blood , Anesthetics, Intravenous , Animals , Electric Stimulation , Hindlimb , Male , Motor Cortex/anatomy & histology , Motor Cortex/physiology , Propofol , Rats , Rats, Sprague-Dawley , Somatosensory Cortex/anatomy & histology , Somatosensory Cortex/physiology
14.
Diabetes ; 48(1): 150-7, 1999 Jan.
Article in English | MEDLINE | ID: mdl-9892237

ABSTRACT

The aim of the study was 1) to establish the prevalence of GAD antibodies (GADab) in a population-based study of type 2 diabetes in western Finland, 2) to genetically and phenotypically characterize this subgroup, and 3) to provide a definition for latent autoimmune diabetes in adults (LADA). The prevalence of GADab was 9.3% among 1,122 type 2 diabetic patients, 3.6% among 558 impaired glucose tolerance (IGT) subjects, and 4.4% among 383 nondiabetic control subjects. Islet antigen 2 antibodies (IA2ab) or islet cell antibodies were detected in only 0.5% of the GADab- patients. The GADab+ patients had lower fasting C-peptide concentrations (median [interquartile range]: 0.46 [0.45] vs. 0.62 [0.44] nmol/l, P = 0.0002) and lower insulin response to oral glucose compared with GADab- patients. With respect to features of the metabolic syndrome, the GADab+ patients had lower systolic (140 [29.1] vs. 148 [26.0] mmHg, P = 0.009) and diastolic (79.2 [17.6] vs. 81.0 [13.1] mmHg, P = 0.030) blood pressure values, as well as lower triglyceride concentrations (1.40 [1.18] vs. 1.75 [1.25] mmol/l, P = 0.003). GADab+ men had a lower waist-to-hip ratio compared with GADab- patients. Compared with GADab- patients and control subjects, the GADab+ patients had an increased frequency HLA-DQB1*0201/0302 (13 vs. 4%; P = 0.002) and other genotypes containing the *0302 allele (22 vs. 12%; P = 0.010). However, the frequency of these high-risk genotypes was significantly lower in GADab+ type 2 patients than in type 1 diabetes of young or adult onset (0201/0302 or 0302/X: 36 vs. 66 vs. 64%, P < 0.001). The GADab+ type 2 group did not differ from control subjects with respect to genotypes containing the protective DQB1-alleles *0602 or *0603, nor with respect to the type 1 high-risk genotype in the IDDM1 (Hph1 +/+). We conclude that GADab+ patients differ from both GADab- type 2 diabetic patients and type 1 diabetic patients with respect to beta-cell function, features of the metabolic syndrome, and type 1 diabetes susceptibility genes. Further, we propose that LADA be defined as GADab positivity (>5 relative units) in patients older than 35 years at onset of type 2 diabetes.


Subject(s)
Autoantibodies/analysis , Diabetes Mellitus, Type 2/immunology , Diabetes Mellitus, Type 2/physiopathology , Glutamate Decarboxylase/immunology , Alleles , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/physiopathology , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/genetics , Female , Genotype , Glucose Intolerance/physiopathology , HLA-DQ Antigens/genetics , HLA-DQ beta-Chains , Humans , Hypoglycemic Agents/therapeutic use , Insulin/genetics , Insulin/therapeutic use , Male , Middle Aged , Polymorphism, Genetic/genetics , Polymorphism, Restriction Fragment Length , Reference Values
15.
J Neurosci Methods ; 82(1): 75-83, 1998 Jul 01.
Article in English | MEDLINE | ID: mdl-10223517

ABSTRACT

Functional magnetic resonance imaging (fMRI) in humans has helped improve our understanding of the neuroanatomical organization of behavior. Unfortunately, fMRI in animal studies has not kept pace with the human work. Experiments are limited because animals must be anesthetized to prevent motion artifacts, precluding most studies involving neuroimaging of brain activity during behavior. The present study tested a newly developed head and body holder for performing fMRI in fully conscious animals. Significant changes in signal intensities were observed in the somatosensory cortex of conscious rats in response to electrical shock of the hindpaw. These changes in evoked signal ranged between 4 and 19% and were accompanied by significant increases in local cerebral blood flow. The fMRI study was performed with a 2.0-Tesla spectrometer. Using this non-invasive method of imaging brain activity in conscious animals, it is now possible to perform developmental studies in animal models of neurological and psychiatric disorders.


Subject(s)
Brain/anatomy & histology , Magnetic Resonance Imaging/methods , Animals , Artifacts , Electroshock , Male , Motion , Rats , Rats, Sprague-Dawley , Restraint, Physical , Somatosensory Cortex/anatomy & histology
17.
Lett Appl Microbiol ; 21(2): 109-14, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7639991

ABSTRACT

Simple and easy-to-use bioassays with Artemia salina (brine shrimp) larvae, luminescent bacteria and Pseudomonas putida were evaluated for the detection of toxicity due to cyanobacterial hepato- and neurotoxins. The hepatotoxins and a neurotoxin, anatoxin-a, were extracted from laboratory-grown cultures and natural bloom samples by the solid phase fractionation method and dissolved in diluent for different bioassays. The toxin concentration of cyanobacterial extracts was determined with HPLC. The Artemia biotest appeared to be quite sensitive to cyanobacterial hepatotoxins, with LC 50 values of 3-17 mg l-1. The Artemia test was also shown to be of value for the detection of toxicity caused by anatoxin-a. The fractionated extract of anatoxin-a was not lethal to Artemia but it disturbed the ability of the larvae to move forwards. Filtered cyanobacterial cultures with anatoxin-a, on the other hand, caused mortality of Artemia larvae at concentrations of 2-14 mg l-1. With the solid phase fractionation of cyanobacterial samples, no non-specific toxicity due to compounds other than hepato- and neurotoxins was observed. In the luminescent bacteria test, the inhibition of luminescence did not correlate with the abundance of hepatotoxins or anatoxin-a. The growth of Ps. putida was enhanced, rather than inhibited by cyanobacterial toxin fractions.


Subject(s)
Artemia/drug effects , Bacterial Toxins/toxicity , Cyanobacteria/chemistry , Marine Toxins/toxicity , Animals , Bacterial Toxins/isolation & purification , Cyanobacteria Toxins , Marine Toxins/isolation & purification , Microcystins , Peptides, Cyclic/isolation & purification , Peptides, Cyclic/toxicity , Photobacterium/drug effects , Pseudomonas putida/drug effects , Tropanes , Vibrio/drug effects
18.
Lett Appl Microbiol ; 19(6): 423-8, 1994 Dec.
Article in English | MEDLINE | ID: mdl-7765705

ABSTRACT

Cyanobacterial hepatotoxins and anatoxin-a, a neurotoxin, were shown to be degraded when crude extracts of lysed toxic laboratory strains of cyanobacteria were exposed to natural populations of micro-organisms from lakes. While anatoxin-a decayed equally fast with all the inocula from lake sediment and water, the degradation rate of hepatotoxins was higher with inocula from places at which cyanobacterial water blooms had occurred than with inocula from places with no known mass occurrences of cyanobacteria. Degradation was slowest when an inoculum from a humic lake was used. A part of the loss of the toxins was shown to be due to adsorption on lake sediments.


Subject(s)
Bacterial Toxins/metabolism , Cyanobacteria/chemistry , Marine Toxins/metabolism , Water Microbiology , Adsorption , Biodegradation, Environmental , Cytotoxins/metabolism , Fresh Water , Liver/drug effects , Microcystins , Neurotoxins/metabolism , Peptides, Cyclic/metabolism , Soil Microbiology
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