Prolonged injury symptoms and later visits to psychiatric care after mild traumatic brain injury in school-age.

OBJECTIVE: To investigate demographic and pre-injury factors in Finnish school-aged children admitted to pediatric neurology services after mild traumatic brain injury (mTBI). The relation of these factors to prolonged injury symptoms and later visits into psychiatric care was assessed. METHODS: Demographic information, pre-injury learning status, and neuropsychological test results of 120 patients aged 7-16 years were retrospectively collected from the hospital medical records. Data were compared with self- or parent-reported injury symptoms at 1-3 months post-injury and later visits to psychiatric care. RESULTS: According to medical records, 14.2% of the children with mTBI had a diagnosed neurobehavioral or psychiatric condition pre-injury. Additionally, 53.3% of the children had some neurobehavioral or psychiatric concerns or traits prior to the injury. Over half (56.7%) of the children studied were symptomatic at 1-3 months following the injury. Female gender and presence of prolonged symptoms were predictive for later visit into psychiatric care. CONCLUSIONS: Pre-injury neurobehavioral or psychiatric problems may predict prolonged injury symptoms following pediatric mTBI. In this retrospective patient series, prolonged symptoms and female gender seem to predict the need for later psychiatric care. Monitoring the recovery of children with mTBI and pre-injury risk factors is important for timely interventions.

Medical surveillance for occupational asthma-how are cases detected?

BACKGROUND: In Finland, medical surveillance, including spirometry, is periodically performed for workers who are exposed to agents capable of causing occupational asthma (OA). Although it has been shown that surveillance can detect OA at an early stage, few studies have assessed its benefits or the role of surveillance spirometry. AIMS: To assess the role of surveillance and spirometry in detecting OA and to evaluate the quality of spirometry. METHODS: We retrospectively reviewed the medical files of patients in health surveillance programmes who were diagnosed with sensitizer-induced OA at the Finnish Institute of Occupational Health in 2012‒14. We collected information on work exposure, respiratory symptoms, healthcare visits that initiated the diagnostic process, first spirometry and other diagnostic tests. RESULTS: Sixty files were reviewed. Medical surveillance detected 11 cases (18%) and 49 cases (82%) were detected at doctors' appointments that were not related to surveillance. The median delay from the onset of asthma symptoms to diagnosis was 2.2 years. Delay did not differ between these groups. No cases were detected on the basis of abnormal spirometry without respiratory symptoms. However, five patients (8%) initially reported solely work-related rhinitis symptoms. Spirometry was normal in half of the cases and quality criteria were fulfilled in 86% of the tests. CONCLUSIONS: Fewer than one in five OA cases were detected through medical surveillance. Investigations were initiated by respiratory symptoms. No asymptomatic worker was referred because of abnormal spirometry. Our results highlight the importance of work-related nasal symptoms in detecting OA.

Effect of probiotic supplementation on total lactobacilli, bifidobacteria and short chain fatty acids in 2-5-year-old children.

​Background: Consumption of Lactobacillus paracasei Lpc-37 or Bifidobacterium lactis HN019 by 2-5-year-old children was found to reduce risk for diarrhoea and fever during the rainy season. Objective: Can changes in faecal short chain fatty acids (SCFAs) or branched chain fatty acids (BCFAs) explain the observed positive influence of probiotics and their role on nutritional status and diarrhoea risk? Design: Faecal samples were analysed for SCFAs and BCFAs and correlated to Bifidobacterium and Lactobacillus levels; both at the start and after nine months' consumption of either of the two probiotic strains, or placebo. Results: No differences in SCFAs, BCFAs, Lactobacillus or Bifidobacterium levels were found between boys and girls. Severely underweight children were observed to have the highest Lactobacillus levels. Probiotic intervention was found to be associated with higher levels of selected SCFAs and BCFAs in subjects who had experienced diarrhoea. Treatment with either of the probiotics led to changes in SCFAs and BCFAs. SCFAs, acetate, propionate and butyrate, were found to correlate with each other. Likewise, BCFAs isobutyrate, 2-methylbutyrate and isovalerate correlated with each other. After the intervention, L. paracasei Lpc-37 correlated positively with total Bifidobacterium counts and isovalerate levels. B. lactis HN019 counts were found to correlate positively with total bacterial counts and negatively with propionate levels. Conclusions: ​Nutritional status was associated with higher levels of faecal lactobacilli; the meaning of this requires further investigation. The intervention with the two probiotics was observed to influence the levels of faecal SCFAs and BCFAs and there is a differential response in those who developed diarrhoea and those who did not. It is, however, not clear to what extent this is a mechanism that explains the earlier observed effect the strains had on diarrhoea risk.

End-of-life care of patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive disease with median survival from 2 to 7 years. Palliative care is an important part of patients´ care as lung transplantation is not an option for the majority of patients. The aim of this study was to describe treatment practices, decision-making and symptoms during end-of-life care of IPF patients. METHODS: We identified 59 deceased patients from a national prospective IPF cohort study (FinnishIPF) and analyzed retrospectively their health care documentation during the 6 months that preceded death. RESULTS: Hospital was the place of death for 47 patients (80 %). A majority of the patients (93 %) were hospitalized for a mean of 30 days (range 1-96 days) during the last 6 months of their life. Altogether, patients spent 15 % of their last 6 months of life in a hospital. End-of-life decisions and do not resuscitate (DNR) orders were made for 19 (32 %) and 34 (57 %) of the patients, respectively, and 22 (42 %) of these decisions were made ≤ 3 days prior to death. During the final hospital stay, antibiotics were given to 79 % and non-invasive ventilation to 36 % of patients. During the last 24 h of life, radiologic imaging or laboratory tests were taken in 19 % and 53 % of the hospitalized patients, respectively. These tests and life prolonging therapies were more common in tertiary hospitals compared to other places of death. Dyspnea (66 %) and pain (31 %) were the most common symptoms recorded. Opioids were prescribed to 71 % of the patients during the last week before death. CONCLUSIONS: The majority of IPF patients died in a hospital with ongoing life-prolonging procedures until death. The frequent use of opioids is an indicator of an intention to relieve symptoms, but end-of-life decisions were still made very late. Early integrated palliative care with advance care plan could improve the end-of-life care of dying IPF patients.

Early seroconversion and rapidly increasing autoantibody concentrations predict prepubertal manifestation of type 1 diabetes in children at genetic risk.

AIMS/HYPOTHESIS: The aim of the study was to investigate the timing of the appearance of autoantibodies associated with type 1 diabetes between birth and puberty, the natural fate of these autoantibodies and the predictive power of autoantibody concentrations for early progression to clinical diabetes. METHODS: Children were recruited to the Type 1 Diabetes Prediction and Prevention Project, an ongoing study based on HLA-conferred genetic risk. Autoantibodies against islet cells, insulin, GAD65 and islet antigen 2 were analysed at 3-12 month intervals, starting from birth. RESULTS: During the follow-up, 1,320 children (18.4% of the cohort of 7,165 children) were autoantibody positive in at least one sample. Altogether, 184 autoantibody-positive children progressed to type 1 diabetes. Seroconversion occurred at an early age in the progressors (median 1.5 years), among whom 118 (64%) and 150 (82%) seroconverted to autoantibody positivity before the age of 2 and 3 years, respectively. The incidence of seroconversion peaked at 1 year of age. Compared with other autoantibody-positive children, the median autoantibody levels were already markedly higher 3 to 6 months after the seroconversion in children who later progressed to diabetes. CONCLUSIONS/INTERPRETATION: Early initiation of autoimmunity and rapid increases in autoantibody titres strongly predict progression to overt diabetes before puberty, emphasising the importance of early life events in the development of type 1 diabetes.

Dietary and lifestyle counselling reduces the clustering of overweight-related cardiometabolic risk factors in adolescents.

AIM: The aim of this study was to evaluate the impact of individualised dietary and lifestyle counselling, primarily aimed to decrease serum low-density lipoprotein cholesterol, on the clustering of overweight-related cardiometabolic risk factors in children. DESIGN AND PARTICIPANTS: The 7-month-old study children were randomized either to counselling (n = 540) or control group (n = 522). MAIN OUTCOME MEASURES: The 5- to 15-year-old participants who fulfilled the international criteria were classified as overweight. Being in the highest [lowest for high-density lipoprotein (HDL) cholesterol] age- and gender-specific quintile of body mass index (BMI), blood pressure, serum triglycerides, HDL cholesterol or glucose was considered a risk factor. A cluster was defined as having high BMI and > or = 2 other risk factors. RESULTS: The counselling did not reduce the prevalence of overweight in 5- to 15-year-old participants. From age 7 onwards, the proportion of children with > or = 2 risk factors was lower in the intervention than in the control group (p = 0.005). At the age of 15 years, 13.0% of girls and 10.8% of boys in the intervention group and 17.5% of girls and 18.8% of boys in the control group had the risk factor cluster (p = 0.046 for main effect of the study group). Having even one risk factor at the age of 5 years predicted the clustering of risk factors at the age of 15 years (OR: 3.8, p < 0.001). CONCLUSION: Repeated, individualized dietary and lifestyle counselling may reduce the clustering of overweight-related cardiometabolic risk factors in adolescents even though the counselling is not intense enough to prevent overweight.

The effect of feeding essential oils on broiler performance and gut microbiota.

1. In this study the effect of a blend of essential oils (EO) comprising 15 g/tonne thymol and 5 g/tonne cinnamaldehyde on the performance and intestinal microbiota of broilers was investigated. 2. A total of 720 male Ross broilers were divided into two dietary treatments with 12 replicate pens per treatment. Broilers were given a control soybean-wheat-based diet with or without added EO in two diet phases (0-21 d and 22-42 d). 3. The blend of EO increased body weight gain of broilers from 0 to 42 d by 45%. 4. Caecal microbiota were affected by the EO blend; in particular increases in the proportions of Lactobacillus and Escherichia coli at 41 d was observed. 5. The EO blend had major effects on caecal metabolites. The proportion of caecal butyrate at 20 and 41 d of age increased, whereas the proportion of caecal acetic acid at 20 d, and propionic acid and isovaleric acid at 41 d, decreased with the EO blend. In addition, the caecal proportion of spermine increased and tyramine decreased at 41 d of age with the EO treatment. 6. The present study shows that EO supplementation exerts a positive effect on intestinal microbiota with a concomitant enhancement in growth performance. The study suggests that modulation of broiler gut microbiota composition and activity through the administration of EO offers an effective means for improving broiler performance.

Dental patient education: a survey from the perspective of dental hygienists.

OBJECTIVES: The aim of this study was to describe the current patient education practices of dental hygienists by exploring their views concerning their skills and knowledge related to patient education and by determining the implementation of patient education in their work, with regard to both method and content. METHODS: The target group consisted of 416 dental hygienists (n = 222, 53%) The research strategy used was a survey. The material was gathered using questionnaire. RESULTS: According to the dental hygienists, their skills and knowledge about patient education were good. However, the implementation of education was not in line with these assessments. The content of the education given focused mostly on the functional dimension. Little use was made of various educational methods, and the dental hygienists felt that they were not in good enough command of the methods. The patient's expectations and learning were not assessed systematically. The education provided and the assessment of the need for education often focused on the professional him/herself and the standpoint of the patient empowerment was disregarded. CONCLUSIONS: These results lay the foundation for additional research aimed at developing the patient education given by these professionals and making it support the empowerment of each patient.

Probiotic or synbiotic alters the gut microbiota and metabolism in a randomised controlled trial of weight management in overweight adults.

The gut microbiota contributes to host energy metabolism, and altered gut microbiota has been associated with obesity-related metabolic disorders. We previously reported that a probiotic alone or together with a prebiotic controls body fat mass in healthy overweight or obese individuals in a randomised, double-blind, placebo controlled clinical study (ClinicalTrials.gov NCT01978691). We now aimed to investigate whether changes in the gut microbiota may be associated with the observed clinical benefits. Faecal and plasma samples were obtained from a protocol compliant subset (n=134) of participants from a larger clinical study where participants were randomised (1:1:1:1) into four groups: (1) placebo, 12 g/d microcrystalline cellulose; (2) Litesse® Ultra™ polydextrose (LU), 12 g/day; (3) Bifidobacterium animalis subsp. lactis 420™ (B420), 1010 cfu/d in 12 g microcrystalline cellulose; (4) LU+B420, 1010 cfu/d of B420 in 12 g/d LU for 6 months of intervention. The faecal microbiota composition and metabolites were assessed as exploratory outcomes at baseline, 2, 4, 6 months, and +1 month post-intervention and correlated to obesity-related clinical outcomes. Lactobacillus and Akkermansia were more abundant with B420 at the end of the intervention. LU+B420 increased Akkermansia, Christensenellaceae and Methanobrevibacter, while Paraprevotella was reduced. Christensenellaceae was consistently increased in the LU and LU+B420 groups across the intervention time points, and correlated negatively to waist-hip ratio and energy intake at baseline, and waist-area body fat mass after 6 months treatment with LU+B420. Functional metagenome predictions indicated alterations in pathways related to cellular processes and metabolism. Plasma bile acids glycocholic acid, glycoursodeoxycholic acid, and taurohyodeoxycholic acid and tauroursodeoxycholic acid were reduced in LU+B420 compared to Placebo. Consumption of B420 and its combination with LU resulted in alterations of the gut microbiota and its metabolism, and may support improved gut barrier function and obesity-related markers.

Declining trend in the incidence of biopsy-verified coeliac disease in the adult population of Finland, 2005-2014.

BACKGROUND: The frequency of coeliac disease (CD) has been on the rise over the past decades, especially in Western Europe, but current trends are unclear. AIM: To research the recent temporal changes in the incidence of adult, biopsy-verified coeliac disease and dermatitis herpetiformis (DH) in Finland, a country with a high frequency of coeliac disease. METHODS: All coeliac disease and DH cases diagnosed at age 20-79 years during 2005-2014 were retrieved from a nationwide database documenting all applicants for monthly compensation to cover the extra cost of maintaining a gluten-free diet. This benefit is granted on the basis of histology, not socioeconomic status. Temporal trends in the annual incidences were estimated using Poisson regression analyses. RESULTS: The total incidence of coeliac disease decreased from 33/100 000 during the years 2005-2006 to 29/100 000 during 2013-2014. The mean annual incidence of coeliac disease was nearly twice as high among women as among men, 42 vs 22 per 100 000, respectively. For middle- and old-aged women, the average rate of decrease in incidence was 4.8% (95% CI 3.9-5.7) per year and for men 3.0% (1.8-4.1) (P for linear trend <.001, for both). Similarly, the annual incidence of DH declined. For young adults, the rate of change remained low and nonsignificant throughout the period 2005-2014. CONCLUSIONS: Although the awareness of coeliac disease has increased during the past decades, the incidence of biopsy-verified diagnoses is not increasing, which suggests that exposure to yet unidentified triggering factors for coeliac disease has plateaued among the Finnish adult population.

Crystal structure of thioredoxin-2 from Anabaena.

BACKGROUND: Thioredoxins are ubiquitous proteins that serve as reducing agents and general protein disulfide reductases. The structures of thioredoxins from a number of species, including man and Escherichia coli, are known. Cyanobacteria, such as Anabaena, contain two thioredoxins that exhibit very different activities with target enzymes and share little sequence similarity. Thioredoxin-2 (Trx-2) from Anabaena resembles chloroplast type-f thioredoxin in its activities and the two proteins may be evolutionarily related. We have undertaken structural studies of Trx-2 in order to gain insights into the structure/function relationships of thioredoxins. RESULTS: Anabaena Trx-2, like E. coli thioredoxin, consists of a five-stranded beta sheet core surrounded by four alpha helices. The active site includes a conserved disulfide ring (in the sequence 31WCGPC35). An aspartate (E. coli) to tyrosine (Trx-2) substitution alters the position of this disulfide ring relative to the central pleated sheet. However, loss of this conserved aspartate does not affect the disulfide geometry. In the Trx-2 crystals, the N-terminal residues make extensive contacts with a symmetry-related molecule with hydrogen bonds to residues 74-76 mimicking thioredoxin-protein interactions. CONCLUSIONS: The overall three-dimensional structure of Trx-2 is similar to E. coli thioredoxin and other related disulfide oxido-reductases. Single amino acid substitutions around the protein interaction area probably account for the unusual enzymatic activities of Trx-2 and its ability to discriminate between substrate and non-substrate peptides.

Crystal structure of Arabidopsis thaliana NADPH dependent thioredoxin reductase at 2.5 A resolution.

Thioredoxin exists in all organisms and is responsible for the hydrogen transfer to important enzymes for ribonucleotide reduction and the reduction of methionine sulphoxide and sulphate. Thioredoxins have also been shown to regulate enzyme activity in plants and are also involved in the regulation of transcription factors and several other regulatory activities. Thioredoxin is reduced by the flavoenzyme thioredoxin reductase using NADPH. We have now determined the first structure of a eukaryotic thioredoxin reductase, from the plant Arabidopsis thaliana, at 2.5 A resolution. The dimeric A. thaliana thioredoxin reductase is structurally similar to that of the Escherichia coli enzyme, and most differences occur in the loops. Because the plant and E. coli enzymes have the same architecture, with the same dimeric structure and the same position of the redox active disulphide bond, a similar mechanism that involves very large domain rotations is likely for the two enzymes. The subunit is divided into two domains, one that binds FAD and one that binds NADPH. The relative positions of the domains in A. thaliana thioredoxin reductase differ from those of the E. coli reductase. When the FAD domains are superimposed, the NADPH domain of A. thaliana thioredoxin reductase must be rotated by 8 degrees to superimpose on the corresponding domain of the E. coli enzyme. The domain rotation we now observe is much smaller than necessary for the thioredoxin reduction cycle.

Crystallographic investigation of the dependence of calcium and phosphate ions for notexin.

The crystal structure of the neurotoxic phospholipase A2, notexin, revealed three binding sites for sulphate ions which were suggested to be phosphate binding sites of importance for the activity of the toxin. The present investigation shows that the sulphate ion bound to the major binding site alters the structure of residues 60-75. In the absence of sulphate and phosphate, the structure of this loop has a conformation which partly resembles the non-neurotoxic PLA2s. The affinity of notexin for phosphate is 17 microM, as measured by the increase in fluorescence at 345 nm. Since the concentrations of phosphate and sulphate ions in blood plasma are 3 and 1 mM, respectively, the binding site must be occupied under physiological conditions. This major sulphate/phosphate binding site explains the specific affinity labelling by pyridoxal phosphate. Pyridoxal phosphate binds to this anion binding site which allows the reaction with Lys-88 or Lys-89. The structure of notexin in the presence and absence of Ca2+ shows only small local structural differences.

Acute appendicitis not associated with social class among children.

Acute appendicitis has previously been found to be associated with social class. In an attempt to confirm this, 125 patients with histologically verified acute appendicitis were compared with 1802 control children, randomly selected from the schools of the City of Helsinki. Social class determination was based on father's occupation in families with two parents, and on mother's occupation in single provider families. No association with social class was found. The proportion of single provider families was around 25% among both cases and controls. Appendicitis patients are one potential source of control groups in epidemiological studies.

Survival and degradation of Salmonella enterica serotype Enteritidis in intestinal epithelial cells in vitro.

The survival and fate of Salmonella enterica serotype Enteritidis in Henle-407 human intestinal epithelial cells was investigated during prolonged incubation to evaluate the persistence of causative microbes and the relationship to patients developing reactive arthritis. Most of the bacteria were killed and degraded quite soon after infection of the cells, but there were still live bacteria inside the cells for up to 14 days. These results suggest that in patients developing reactive arthritis the salmonellae could persist in the epithelial cells and spread within the host to the joint and be present there at the time of the inflammatory response. Production of marked amounts of nitric oxide was observed as a novel response to salmonella infection in human intestinal epithelial cells. The present experimental procedure appears to be a suitable model to further investigate host-bacteria interaction in HLA-B27 positive cells from patients developing reactive arthritis.

The three-dimensional structures of two toxins from snake venom throw light on the anticoagulant and neurotoxic sites of phospholipase A2.

The three-dimensional structures of the class II anticoagulant phospholipase A2 (PLA2) toxin RVV-VD from the venom of Russell's viper, Vipera russelli russelli, and the class I neurotoxic PLA2 Notechis II-5 from the, Australian tiger snake, Notechis scutatus scutatus, were determined to 2.2 A and 3.0 A resolution, respectively. Both enzymes are monomeric and consist of 121 and 119 residues, respectively. A comparison of ten class I/II PLA2 structures showed, among other differences, that the beta-sheet of these enzymes (residues 76-83) is about 90 degrees less twisted in class I than in class II PLA2s. This, along with the insertion of some residues in the region 57-59 in class I enzymes (the elapid loop), could be the main reason for the significant difference in the anticoagulant and (presynaptic) neurotoxic properties between the two classes of PLA2. It seems apparent from sequence and structural comparisons that the toxic site of PLA2 responsible for the strong anticoagulancy of these toxins consists of a negatively charged part, Glu53, together with a positively charged ridge of lysine residues free for intermolecular interactions. These lysines differ between the two classes of PLA2.

Rate effect and mismatch responses in the somatosensory system: ERP-recordings in humans.

In the first experiment, somatosensory event-related potentials (SERPs) were recorded to tactile pulses and vibration bursts applied to the left middle finger in trains of 4-8 stimuli with 1 s intervals. In addition to the negative N140 deflection, also the positive P50, P100 and P300 waves attenuated in amplitude with stimulus repetition. These decreases were immediate, there being no marked further amplitude attenuation after the second stimulus. The locus of this rate effect appears not to be the primary SI or SII, but rather prefrontal cortices or some deeper structures. In the second experiment, vibratory stimuli of different frequencies or at different skin sites were presented using the oddball paradigm. When the deviant stimulus was a high-frequency vibration burst, it elicited a distinct N250 deflection, probably analogous to the auditory N2b. When the deviation was a change in the stimulation site, no N250 deflection but instead an extra negativity between 100-200 ms latency, probably analogous to the auditory mismatch negativity, was observed.

Culture in the rotating-wall vessel affects recombinant protein production capability of two insect cell lines in different manners.

The production of recombinant secreted alkaline phosphatase protein in virally infected insect cells was studied in shaker flask and high aspect rotating-wall vessel (HARV) culture. Two commonly used cell lines, Spodoptera frugiperda Sf-9 (Sf-9) and a nonaggregating isolate of the Trichoplusia ni BTI-Tn-5B1-4 (Tn-5B1-4) cell line, Trichoplusia ni Tn-5B1-4-NA (Tn-5B1-4-NA), were used and monitored for 120-h postinfection. Different responses to culture in the HARV were seen in the two cell lines. While the Sf-9 cell line was able to produce slightly greater amounts of recombinant protein in the HARV than in shaker flask controls, the Tn-5B1-4-NA cell line produced significantly lesser amounts in the HARV than in the shaker flasks. Both cell lines exhibited longer life spans and longer periods of protein production in HARV culture than in shaker flask culture, presumably due to lower levels of shear encountered in the HARV. The important difference was in the protein production rate responses of the two cell lines. While the protein production rates of Sf-9 cells were comparable in both HARV and shaker flask cultures, the protein production rates of Tn-5B1-4-NA cells were much lower in HARV culture than in shaker flask cultures. The conclusion is drawn that cell line-specific adaptation to the HARV strongly influences recombinant protein production.

A novel method to analyze betaine in chicken liver: effect of dietary betaine and choline supplementation on the hepatic betaine concentration in broiler chicks.

Betaine was measured from liver tissue by a high-performance liquid chromatographic (HPLC) method developed for this study. The method involves homogenization of liver in acetate buffer at pH 6 and precipitation of protein with trichloroacetic acid, which was removed by diethyl ether extraction. Betaine was separated using a cation exchange column in Ca(2+) form and detected with a refractive index detector. This method also allows the determination of S-adenosylmethionine (S-AM) from the same liver extract but with different HPLC conditions. Broiler chicks were fed with experimental diets supplemented with four different doses of betaine or choline ranging from 0 to 5 mol equiv. After a 3 week feeding period, the livers were analyzed for betaine and S-AM. Dietary betaine was twice as efficient in increasing the hepatic betaine concentration as dietary choline. The hepatic S-AM concentrations were similar in all dietary treatments.

Aspects of the ecology and natural history of Paraergasilus rylovi (Copepoda, Ergasilidae) parasitic in unionids of Finland.

The distribution of Paraergasilus rylovi in 17 populations of unionids was investigated. In 1 unionid population, the parasite was studied regarding host age, size, sex, and the reproductive period (occurrence of egg sacs). Results from pooled material from the years 1987--1989 and 1996 (southern Finland, 11 populations) indicated that Anodonta piscinalis (n = 1,359) is the main host (total mean prevalence 71% and intensity +/-SE of infection 16.4+/-0.6). Pseudanodonta complanata (n = 106) was infected occasionally (3% and 1.3+/-0.3), whereas Unio pictorum (n = 108) and U. tumidus (n = 17) were not infected. Results from 17 A. piscinalis populations showed that P. rylovi occurs in southern Finland but not in northern Finland. In A. piscinalis, the mean intensity of infection was higher in lake populations than in river populations. Both host age and length had a negative relationship with the intensity of P. rylovi infection. Host sex did not affect the intensity of infection. Egg sacs of P. rylovi were found from June to August. There was a tendency for higher intensities of infection in autumn. Infection by the digenean Rhipidocotyle fennica had no effect on the intensity of P. rylovi infection.