Invertebrate predation and trophic cascades in a pelagic food web : The multiple roles of Chaoborus flavicans (Meigen) in a clay-turbid lake

In lake ecosystems, both fish and invertebrate predators have dramatic effects on their prey communities. Fish predation selects large cladocerans while invertebrate predators prefer prey of smaller size. Since invertebrate predators are the preferred food items for fish, their occurrence at high densities is often connected with the absence or low number of fish. It is generally believed that invertebrate predators can play a significant role only if the density of planktivorous fish is low. However, in eutrophic clay-turbid Lake Hiidenvesi (southern Finland), a dense population of predatory Chaoborus flavicans larvae coexists with an abundant fish population. The population covers the stratifying area of the lake and attains a maximum population density of 23000 ind. m-2. This thesis aims to clarify the effects of Chaoborus flavicans on the zooplankton community and the environmental factors facilitating the coexistence of fish and invertebrate predators. In the stratifying area of Lake Hiidenvesi, the seasonal succession of cladocerans was exceptional. The spring biomass peak of cladocerans was missing and the highest biomass occurred in midsummer. In early summer, the consumption rate by chaoborids clearly exceeded the production rate of cladocerans and each year the biomass peak of cladocerans coincided with the minimum chaoborid density. In contrast, consumption by fish was very low and each study year cladocerans attained maximum biomass simultaneously with the highest consumption by smelt (Osmerus eperlanus). The results indicated that Chaoborus flavicans was the main predator of cladocerans in the stratifying area of Lake Hiidenvesi. The clay turbidity strongly contributed to the coexistence of chaoborids and smelt at high densities. Turbidity exceeding 30 NTU combined with light intensity below 0.1 μE m-2 s-1provides an efficient daytime refuge for chaoborids, but turbidity alone is not an adequate refuge unless combined with low light intensity. In the non-stratifying shallow basins of Lake Hiidenvesi, light intensity exceeds this level during summer days at the bottom of the lake, preventing Chaoborus forming a dense population in the shallow parts of the lake. Chaoborus can be successful particularly in deep, clay-turbid lakes where they can remain high in the water column close to their epilimnetic prey. Suspended clay alters the trophic interactions by weakening the link between fish and Chaoborus, which in turn strengthens the effect of Chaoborus predation on crustacean zooplankton. Since food web management largely relies on manipulations of fish stocks and the cascading effects of such actions, the validity of the method in deep clay-turbid lakes may be questioned.

Adaptation of the Australian core food groups to enable planning of vegan and lactovegetarian diets

This work demonstrates how the Australian core food groups system can be modified to enable the planning of vegan and lactovegetarian diets as well as omnivorous diets. In the modified version the cereals, vegetables and fruits groups remain the same as in the core food groups system, while the meat group is replaced with legumes, soya products, nuts and seeds. The milk group becomes milk or fortified soya milk, to allow for both lactovegetarian and vegan diets. The core food groups standard of 70% of the recommended dietary intake was adopted as a target for determining recommendations on the minimum number of serves from each food group. As found in the development of the core food groups system, zinc was the most limiting nutrient. Vitamin B 12 and calcium were other limiting nutrients in the vegan and lactovegetarian guides. The number of serves from each group required to meet 70% of the applicable recommended dietary intake has been calculated for children from four years old, adult men and women and pregnant and lactating women. It was found that the number of serves from each food group required in the vegan and lactovegetarian planning guides was in most cases similar to the number of serves of corresponding core food groups specified for a particular population group. This suggests that the vegan and lactovegetarian planning guides could be incorporated into a modified core food groups planning guide. Such a guide would cater for the general omnivorous population as well as for those seeking to avoid meat and/or dairy products. (Aust J Nutr Diet 1999:56:22-30) Key words: vegan, vegetarian, food guide, food groups, dietary planning.

Lactobacillus bacteremia, with special focus on the safety of probiotic Lactobacillus rhamnosus GG

Lactobacilli are gram positive rods, which belong to normal oropharyngeal, gastrointestinal and urogenital flora. They are widely used in food industry and as food additives. Although their virulence is presumed to be very low, opportunistic bacteremic infections, especially in immunocompromised hosts, have been detected. In the present study, the possible effects of increasing probiotic use of Lactobacillus rhamnosus GG (LGG) on the occurrence of bacteremia due to lactobacilli was evaluated on population level. In Finland, 90 Lactobacillus bacteremia cases were reported to the National Infectious Disease Register maintained by National Public Health Institute, during 1995-2000. Their proportion of all bacteremia cases was on average 0.24%, corresponding to 0.3 cases/100 000 inhabitants annually. In the Helsinki University Central Hospital district the corresponding proportion of all bacteremia cases was observed during 1990-2000. Despite LGG intake increased six folded no increasing trend in the occurrence of lactobacilli bacteremia was seen. A total of 85 Lactobacillus sp. blood isolates collected from different human bacteremic cases were characterised and compared with the commercial probiotic LGG strain. In species characterisation 46 L. rhamnosus strains, 12 L. fermentum and L. casei strains each, three each of L. gasseri, L. salivarius and L. jensenii species, two L. curvatus, and one each of L. plantarum, L. sakei, L. zeae and L. reuteri species were detected. Nearly half of the L. rhamnosus findings turned out to be indistinguishable from the probiotic LGG strain. Common predisposing factors to Lactobacillus bacteremia were immunosuppression, prior prolonged hospitalisation and prior surgical interventions. Severe or fatal comorbidities were found in 82% of the patients. Mortality at one month was 26% and severe underlying diseases were a significant predictor of death (OR 15.8). Antimicrobial susceptibility of Lactobacillus strains was species dependent. The Lactobacillus isolates were generally susceptible to imipenem, piperacillin-tazobactam, clindamycin and erythromycin, whereas all other than L. gasseri and L. jensenii species were not at all susceptible to vancomycin. The susceptibility to cephalosporin varied greatly even within species why they might not be recommended for treatment of Lactobacillus infections. The effect and safety of probiotic LGG preparation in amelioration of gastric symptoms and diarrhea in HIV-infected patients was evaluated. No significant differences in gastrointestinal symptoms or diarrhoea in LGG treated patients compared to placebo could be found. LGG was well tolerated with no adverse effects including bacteremic outbreaks could be observed. The use of probiotic LGG can be regarded safe in this immunocompromised patient group.

Hospital-related fears and coping strategies in 4-6-year-old children

There is only little information available on the 4-6-year-old child s hospital-related fears, and on the coping with such fears, as expressed by the children themselves. However, previous data collected from parents and hospital personnel indicate that hospitalization is an anxiety-producing experience for young children. The purpose of this study was to describe the experience of hospital-related fears and the experience of coping with hospital-related fears of 4-6-year-old children. The aim of this study was to form a descriptive model of the subjective experience of hospital-related fears and coping strategies of 4-6-year old children. The data were collected by interviewing 4-6-year-old children from a hospital and kindergarten settings in Finland from 2004 to 2006. Ninety children were interviewed in order to describe the hospital-related fear and the experience of fear, and 89 to describe their coping with the fear and the experience of coping. The children were chosen through purposive sampling. The data were gathered by semi-structured interview, supported by pictures. The data about hospital-related fears and on strategies for coping with hospital-related fears were reviewed by qualitative and quantitative methods. The experience of hospital-related fears and coping with these fears were analyzed using Colaizzi s Method of Phenomenological Analysis. The results revealed that more than 90 % of the children said they were afraid of at least one thing in hospital. Most of the fears could be categorized as nursing interventions, fears of being a patient, and fears caused by the developmental stage of the child. Children interviewed in the hospital expressed substantially more fears than children interviewed in kindergarten. Children s meanings of hospital-related fears were placed into four main clusters: 1) insecurity, 2) injury, 3) helplessness, 4) and rejection. The results also showed that children have plenty of coping strategies, to deal with their fears, especially such strategies in which the children themselves play an active role. Most often mentioned coping strategies were 1) the presence of parents and other family members, 2) the help of the personnel, 3) positive images and humour, 4) play, and 5) the child s own safety toy. The children interviewed in the hospital mentioned statistically significantly more often play, positive imagination and humour as their coping strategy than children interviewed in kindergarten. The meaning of coping with hospital fears consisted of six clusters: pleasure, security, care, understanding the meaning of the situation participating, and protecting oneself. Being admitted to a hospital is an event which may increase the fears of a 4-6-year-old child. Children who have personal experience of being admitted to a hospital describe more fears than healthy children in kindergarten. For young children, hospital-related fear can be such a distressing experience that it reflects on their feelings of security and their behaviour. Children can sometimes find it difficult to admit their fear. Children need the help of adults to express their hospital-related fears, the objects of the fears, and to cope with the fears. Personnel should be aware of children s fears and support them in the use of coping strategies. In addition to the experiences of security and care, pre-school-aged children need active coping strategies that they can use themselves, regardless of the presence of the parents or nurses. Most of all, children need the possibility to play and experience pleasure. Children can also be taught coping strategies which give them an active, positive role.

Therapeutic hypothermia after cardiac arrest : Studies on neurological and cardiological outcome and prediction of outcome in hypothermia-treated patients resuscitated from out-of-hospital cardiac arrest

The outcome of the successfully resuscitated patient is mainly determined by the extent of hypoxic-ischemic cerebral injury, and hypothermia has multiple mechanisms of action in mitigating such injury. The present study was undertaken from 1997 to 2001 in Helsinki as a part of the European multicenter study Hypothermia after cardiac arrest (HACA) to test the neuroprotective effect of therapeutic hypothermia in patients resuscitated from out-of-hospital ventricular fibrillation (VF) cardiac arrest (CA). The aim of this substudy was to examine the neurological and cardiological outcome of these patients, and especially to study and develop methods for prediction of outcome in the hypothermia-treated patients. A total of 275 patients were randomized to the HACA trial in Europe. In Helsinki, 70 patients were enrolled in the study according to the inclusion criteria. Those randomized to hypothermia were actively cooled externally to a core temperature 33 ± 1ºC for 24 hours with a cooling device. Serum markers of ischemic neuronal injury, NSE and S-100B, were sampled at 24, 36, and 48 hours after CA. Somatosensory and brain stem auditory evoked potentials (SEPs and BAEPs) were recorded 24 to 28 hours after CA; 24-hour ambulatory electrocardiography recordings were performed three times during the first two weeks and arrhythmias and heart rate variability (HRV) were analyzed from the tapes. The clinical outcome was assessed 3 and 6 months after CA. Neuropsychological examinations were performed on the conscious survivors 3 months after the CA. Quantitative electroencephalography (Q-EEG) and auditory P300 event-related potentials were studied at the same time-point. Therapeutic hypothermia of 33ºC for 24 hours led to an increased chance of good neurological outcome and survival after out-of-hospital VF CA. In the HACA study, 55% of hypothermia-treated patients and 39% of normothermia-treated patients reached a good neurological outcome (p=0.009) at 6 months after CA. Use of therapeutic hypothermia was not associated with any increase in clinically significant arrhythmias. The levels of serum NSE, but not the levels of S-100B, were lower in hypothermia- than in normothermia-treated patients. A decrease in NSE values between 24 and 48 hours was associated with good outcome at 6 months after CA. Decreasing levels of serum NSE but not of S-100B over time may indicate selective attenuation of delayed neuronal death by therapeutic hypothermia, and the time-course of serum NSE between 24 and 48 hours after CA may help in clinical decision-making. In SEP recordings bilaterally absent N20 responses predicted permanent coma with a specificity of 100% in both treatment arms. Recording of BAEPs provided no additional benefit in outcome prediction. Preserved 24- to 48-hour HRV may be a predictor of favorable outcome in CA patients treated with hypothermia. At 3 months after CA, no differences appeared in any cognitive functions between the two groups: 67% of patients in the hypothermia and 44% patients in the normothermia group were cognitively intact or had only very mild impairment. No significant differences emerged in any of the Q-EEG parameters between the two groups. The amplitude of P300 potential was significantly higher in the hypothermia-treated group. These results give further support to the use of therapeutic hypothermia in patients with sudden out-of-hospital CA.

Cow’s milk related gastrointestinal symptoms in adults

The purpose of this study was to evaluate subjective food-related gastrointestinal symptoms and their relation to cow’s milk by determining the genotype of adult-type hypolactasia, measuring antibodies against milk protein, and screening the most common cause for secondary hypolactasia, namely coeliac disease. The whole study group comprised 1900 adults who gave a blood sample for the study when they attended a health care centre laboratory for various reasons. Of these 1885 (99%) completed a questionnaire on food-related gastrointestinal symptoms. Study No. I evaluated the prevalence of adult-type hypolactasia and its correlation to self-reported milk induced gastrointestinal symptoms. The testing for hypolactasia was done by determination of the C/T-13910 genotypes of the study subjects. The results show that patients with the C/C-13910 genotype associated with adult type hypolactasia consume less milk than those with C/T-13910 and T/T-13910 genotypes. Study No. II evaluated the prevalence and clinical characteristics of undiagnosed coeliac disease in the whole study population with transglutaminase and endomysium antibodies and their correlation with gastrointestinal symptoms. The prevalence of coeliac disease was 2 %, which is surprisingly high. Serum transglutaminase and endomysium antibodies are valuable tools for recognising an undiagnosed coeliac disease in outpatient clinics. In the study No. III the evaluation of milk protein IgE related hypersensitivity was carried out by stratifying all 756 study subjects with milk related problems and randomly choosing 100 age and sex matched controls with no such symptoms from the rest of the original study group. In the study No. IV 400 serum samples were randomly selected for analyzing milk protein related IgA and IgG antibodies and their correlation to milk related GI-symptoms. The measurement of milk protein IgA, IgE or IgG (studies No. III and IV) did not correlate clearly to milk induced symptoms and gave no clinically significant information; hence their measurement is not encouraged in outpatient clinics. In conclusion, adult type hypolactasia is often considered the reason for gastrointestinal symptoms in adults and determination of the C/T-13910 genotypes is a practical way of diagnosing adult type hypolactasia in an outpatient setting. Undiagnosed coeliac disease, should be actively screened and diagnosed in order to apply a gluten free diet and avoid the GI-symptoms and nutritional deficiencies. Cow’s milk hypersensitivity in the adult population is difficult to diagnose since the mechanism in which it is mediated is still unclear. Measuring of cow’s milk protein specific antibodies IgE, IgA or IgG do not correlate with subjective milk-related GI-symptoms.

Early life determinants of atopy : A 20-year prospective follow-up study on unselected, healthy newborns

Atopy-related allergic diseases, i.e. allergic rhinoconjunctivitis, atopic dermatitis and asthma, have increased in frequency in the industrialized countries. In order to reverse this trend, effective preventive strategies need to be developed. This requires a better understanding of the early-life events leading to the expression of the atopic phenotype. The present study has aimed at defining early-life factors and markers associated with the subsequent development of allergic diseases in a cohort of 200 healthy, unselected Finnish newborns prospectively followed up from birth to age 20 years. Their mothers were encouraged to start and maintain exclusive breastfeeding as long as it was nutritionally sufficient for the infant. Consequently, all the infants received some duration of exclusive breastfeeding, 58% of the infants were on exclusive breastfeeding for the first 6 months of life, and 18% received this feeding at least for the first 9 months. Of the infants, 42% had a family history of allergy. After the first year of follow-up, the children were re-assessed at ages 5, 11 and 20 years with clinical examination, skin prick testing, and parental and personal interviews. Exclusive breastfeeding for over 9 months was associated with atopic dermatitis and symptoms of food hypersensitivity at age 5 years, and with symptoms of food hypersensitivity at age 11 years in the children with a familial allergy. Subjects with allergic symptoms or a positive skin prick test in childhood or adolescence had lower retinol concentrations during their infancy and childhood than others. An elevated cord serum immunoglobulin E concentration predicted subsequent atopic manifestations though with modest sensitivity. Children and adolescents with allergic symptoms, skin prick test positivity and an elevated IgE had lower total cholesterol levels in infancy and childhood than the nonatopic subjects. In conclusion, prolonging strictly exclusive breastfeeding for over 9 months of age was not of help in prevention of allergic symptoms; instead, it was associated with increased atopic dermatitis and food hypersensitivity symptoms in childhood. Due to the modest sensitivity, cord serum IgE is not an effective screening method for atopic predisposition in the general population. Retinol and cholesterol concentrations in infancy were inversely associated with the subsequent development of allergic symptoms. Based on these findings, it is proposed that there may be differences in the inborn regulation of retinol and cholesterol levels in children with and without a genetic susceptibility to atopy, and these may play a role in the development of atopic sensitization and allergic diseases.

Multiphase porous media model for Intermittent Microwave Convective Drying (IMCD) of food

Intermittent microwave convective (IMCD) drying is an advanced drying technology that improves both energy efficiency and food quality during the drying of food materials. Despite numerous experimental studies available for IMCD, there is no complete multiphase porous media model available to describe the process. A multiphase porous media model considering liquid water, gases and the solid matrix inside the food during drying can provide in depth understanding of IMCD. In this article, firstly a multiphase porous media model was developed for IMCD. Then the model is validated against experimental data by comparing moisture content and temperature distributions after each heating and tempering periods. The profile of vapour pressures and evaporation during IMCD are presented and discussed. The relative contribution of water and vapour fluxes due to gas pressure and diffusion demonstrated that the fluxes due are relatively higher in IMCD compared to convection drying and this makes the IMCD faster.

Healing gardens in the Lady Cilento Children’s Hospital: Reflections on benefits, preferences and design from bench diaries

Background Interest in the use of healing gardens in healthcare settings to provide therapeutic benefits is increasing, however insight is needed to determine whether patients, patient families and friends, and staff who spend time in these gardens use these in the manner for which they were designed, and experience the benefits suggested by broader research in this field. Objective(s) Visitors to four of the LCCH gardens have left comments in ‘bench diaries’ (visitors books). Analysis of these comments yields valuable insights into the use of the gardens, enabling reflection on the design intent and outcomes and guidance regarding how the gardens might be better utilised, as well as a basis for further investigation into the use and value of the gardens. Method(s) Comments have been coded and analysed using a thematic analysis approach to identify patterns relating to the reasons for which people appear to come to the healing gardens; benefits they appear to receive from spending time there; and features and aspects of the gardens that they appear to appreciate in particular. Only comments related to the gardens have been used in this analysis, with all comments being deidentified. Outcome/Conclusion Comments left in the Adventure Garden and Secret Garden bench diaries were used for the analysis, as Staff Garden and Babies Garden bench diary comments did not relate to the garden. There were no negative comments relating to the gardens, other than one comment requesting additional benches. The vast majority of comments expressed gratitude for the space. The four most frequently observed themes from the comments left in the Secret Garden Bench Diary indicated that they were seeking ‘time out’ from their experiences of being at the hospital, a desire for a ‘dose of nature’ (greenery, beautiful garden, etc), and fresh air, and that the garden space provided a restorative experience to them in some manner. Comments in the Adventure Garden Bench Diary related predominately to the view. Analysis of the comments emphasises the importance of gardens providing multi-sensory experiences that significantly differentiate the space from the hospital ward and provide visitors with a sense of being away, of peacefulness, and of familiarity with the outside world. Positioning gardens with prospect, and solar aspect, appears important in these regards, as does the presence of visible greenery. Adequate seating in locations that provide pleasing views appears particularly important for staff and adult visitors. Whilst comments in the Bench Diaries did not indicate direct awareness of the stress and anxiety-reducing effects that research elsewhere has found from viewing plants and nature, however these effects may underpin many of these experiences that visitors did share.

Cow's milk allergy and the development of tolerance

Aims: To gain insight on the immunological processes behind cow’s milk allergy (CMA) and the development of oral tolerance. To furthermore investigate the associations of HLA II and filaggrin genotypes with humoral responses to early oral antigens. Methods: The study population was from a cohort of 6209 healthy, full-term infants who in a double-blind randomized trial received supplementary feeding at maternity hospitals (mean duration 4 days): cow’s milk (CM) formula, extensively hydrolyzed whey formula or donor breast milk. Infants who developed CM associated symptoms that subsided during elimination diet (n=223) underwent an open oral CM challenge (at mean age 7 months). The challenge was negative in 112, and in 111 it confirmed CMA, which was IgE-mediated in 83. Patients with CMA were followed until recovery, and 94 of them participated in a follow-up study at age 8-9 years. We investigated serum samples at diagnosis (mean age 7 months, n=111), one year later (19 months, n=101) and at follow-up (8.6 years, n=85). At follow-up, also 76 children randomly selected from the original cohort and without CM associated symptoms were included. We measured CM specific IgE levels with UniCAP (Phadia, Uppsala, Sweden), and β-lactoglobulin, α-casein and ovalbumin specific IgA, IgG1, IgG4 and IgG levels with enzyme-linked immunosorbent assay in sera. We applied a microarray based immunoassay to measure the binding of IgE, IgG4 and IgA serum antibodies to sequential epitopes derived from five major CM proteins at the three time points in 11 patients with active IgE-mediated CMA at age 8-9 years and in 12 patients who had recovered from IgE-mediated CMA by age 3 years. We used bioinformatic methods to analyze the microarray data. We studied T cell expression profile in peripheral blood mononuclear cell (PBMC) samples from 57 children aged 5-12 years (median 8.3): 16 with active CMA, 20 who had recovered from CMA by age 3 years, 21 non-atopic control subjects. Following in vitro β-lactoglobulin stimulation, we measured the mRNA expression in PBMCs of 12 T-cell markers (T-bet, GATA-3, IFN-γ, CTLA4, IL-10, IL-16, TGF-β, FOXP3, Nfat-C2, TIM3, TIM4, STIM-1) with quantitative real time polymerase chain reaction, and the protein expression of CD4, CD25, CD127, FoxP3 with flow cytometry. To optimally distinguish the three study groups, we performed artificial neural networks with exhaustive search for all marker combinations. For genetic associations with specific humoral responses, we analyzed 14 HLA class II haplotypes, the PTPN22 1858 SNP (R620W allele) and 5 known filaggrin null mutations from blood samples of 87 patients with CMA and 76 control subjects (age 8.0-9.3 years). Results: High IgG and IgG4 levels to β-lactoglobulin and α-casein were associated with the HLA (DR15)-DQB1*0602 haplotype in patients with CMA, but not in control subjects. Conversely, (DR1/10)-DQB1*0501 was associated with lower IgG and IgG4 levels to these CM antigens, and to ovalbumin, most significantly among control subjects. Infants with IgE-mediated CMA had lower β -lactoglobulin and α-casein specific IgG1, IgG4 and IgG levels (p<0.05) at diagnosis than infants with non-IgE-mediated CMA or control subjects. When CMA persisted beyond age 8 years, CM specific IgE levels were higher at all three time points investigated and IgE epitope binding pattern remained stable (p<0.001) compared with recovery from CMA by age 3 years. Patients with persisting CMA at 8-9 years had lower serum IgA levels to β-lactoglobulin at diagnosis (p=0.01), and lower IgG4 levels to β-lactoglobulin (p=0.04) and α-casein (p=0.05) at follow-up compared with patients who recovered by age 3 years. In early recovery, signal of IgG4 epitope binding increased while that of IgE decreased over time, and binding patterns of IgE and IgG4 overlapped. In T cell expression profile in response to β –lactoglobulin, the combination of markers FoxP3, Nfat-C2, IL-16, GATA-3 distinguished patients with persisting CMA most accurately from patients who had become tolerant and from non-atopic subjects. FoxP3 expression at both RNA and protein level was higher in children with CMA compared with non-atopic children. Conclusions: Genetic factors (the HLA II genotype) are associated with humoral responses to early food allergens. High CM specific IgE levels predict persistence of CMA. Development of tolerance is associated with higher specific IgA and IgG4 levels and lower specific IgE levels, with decreased CM epitope binding by IgE and concurrent increase in corresponding epitope binding by IgG4. Both Th2 and Treg pathways are activated upon CM antigen stimulation in patients with CMA. In the clinical management of CMA, HLA II or filaggrin genotyping are not applicable, whereas the measurement of CM specific antibodies may assist in estimating the prognosis.