Zooming in on size distribution patterns underlying species coexistence in Baltic Sea phytoplankton.

Scale is a key to determining which processes drive community structure. We analyse size distributions of phytoplankton to determine time scales at which we can observe either fixed environmental characteristics underlying communities structure or competition-driven size distributions. Using multiple statistical tests, we characterise size distributions of phytoplankton from 20-year time series in two sites of the Baltic Sea. At large temporal scales (5-20 years), size distributions are unimodal, indicating that fundamental barriers to existence are here subtler than in other systems. Frequency distributions of the average size of the species weighted by biovolume are multimodal over large time scales, although this is the product of often unimodal short-term (<1 year) patterns. Our study represents a much-needed structured, high-resolution analysis of phytoplankton size distributions, revealing that short-term analyses are necessary to determine if, and how, competition shapes them. Our results provide a stepping-stone on which to further investigate the intricacies of competition and coexistence.

The native bacterioplankton community in the central baltic sea is influenced by freshwater bacterial species.

The Baltic Sea is one of the largest brackish environments on Earth. Despite extensive knowledge about food web interactions and pelagic ecosystem functioning, information about the bacterial community composition in the Baltic Sea is scarce. We hypothesized that due to the eutrophic low-salinity environment and the long water residence time (>5 years), the bacterioplankton community from the Baltic proper shows a native "brackish" composition influenced by both freshwater and marine phylotypes. The bacterial community composition in surface water (3-m depth) was examined at a single station throughout a full year. Denaturing gradient gel electrophoresis (DGGE) showed that the community composition changed over the year. Further, it indicated that at the four extensive samplings (16S rRNA gene clone libraries and bacterial isolates from low- and high-nutrient agar plates and seawater cultures), different bacterial assemblages associated with different environmental conditions were present. Overall, the sequencing of 26 DGGE bands, 160 clones, 209 plate isolates, and 9 dilution culture isolates showed that the bacterial assemblage in surface waters of the central Baltic Sea was dominated by Bacteroidetes but exhibited a pronounced influence of typical freshwater phylogenetic groups within Actinobacteria, Verrucomicrobia, and Betaproteobacteria and a lack of typical marine taxa. This first comprehensive analysis of bacterial community composition in the central Baltic Sea points to the existence of an autochthonous estuarine community uniquely adapted to the environmental conditions prevailing in this brackish environment.

Fibrinogen and the early stages of polymerization to fibrin as studied by dynamic laser light scattering.

Human fibrinogen and the polymerization of fibrin after activation by the enzymes, thrombin and Batroxobin, were studied by means of dynamic laser light scattering (DLS). The apparent diffusion constant, D, for fibrinogen was measured and has a value of (1.80 +/- 0.42) X 10(-7) cm2 X s-1. D was found to contain contributions from the translational diffusion constant (Dt) as well as from the rotational diffusion constant (Dr). A comparison between experimental and calculated values of Dr and Dt suggests that fibrinogen in the absence of added Ca2+ expresses a certain degree of flexibility, while it is straightened in the presence of added Ca2+. The time dependence of D showed periodic oscillations, while the average D values decreased with time. Thrombin and Batroxobin caused similar behaviour of D. The period length was related to the enzyme concentration, clotting time (Ct) and the rate of release of fibrinopeptide A (FPA). No periodic oscillations were observed in experiments where the enzyme was replaced by saline, or in experiments using a dysfunctional fibrinogen (fibrinogen Aarhus) which displayed slow rates of FPA-release and polymerization. We propose that the periodic oscillations in a system far from equilibrium may be explained by conformational changes occurring in the fibrinogen molecule during enzyme activation and polymerization.

Differentiation and survival influences of growth factors in human neuroblastoma.

Human neuroblastoma cell lines are established from high-stage, highly malignant tumours. Despite this and the fact that these tumours are arrested at an early, immature stage, many cell lines have the capacity to undergo neuronal differentiation under proper growth conditions. One such cell line is the noradrenergic SH-SY5Y cell line. These cells can be induced to mature by a variety of modalities, resulting in different mature phenotypes. The use of this cell system as a model to study the stem cell character of neuroblastoma is reviewed and discussed. In particular, we focus on growth factor dependencies in the SH-SY5Y system, and compare that to the normal situation, i.e. growth factor control of sympathetic neuronal and neuroendocrine differentiation during human and rat embryogenesis.

Parallel DNA template preparation using a vacuum filtration sample transfer device.

Solid-phase techniques have facilitated the handling of biochemical analytes. This has stimulated the development of systems by which large sample panels can be analyzed with high levels of security and quality. We describe a sample transfer device based on the principle of vacuum filtration, which enables parallel handling of 96 samples of analytes bound to Sepharose beads. The tool was employed for strand separation of DNA samples, by attracting the beads to filter probes while passing them between the reagent solutions. The samples were analyzed using Pyrosequencing technology and proved to yield genotyping results of high quality. The presented sample preparation procedure provides an important link in the development of integrated systems for rapid genetic analysis at a low cost. In addition, the same filter could be reused extensively with very low risk for detectable cross-contamination between assays and without any reduction in processing capacity, thus further reducing the cost per analyzed sample.

Structure-function relationships of human factor VIII complex studied by thioredoxin dependent disulfide reduction.

A highly purified, multimeric factor VIII complex composed of VIII: vWF and some factor VIII: C contained about 100 disulfides per subunit of Mr 260,000. Limited reduction of disulfide bonds in this complex by NADPH, thioredoxin reductase and thioredoxin leads to partial disaggregation of the multimeric VIII:vWF with concomitant loss of its platelet agglutinating activity in the presence of ristocetin, and with dissociation of factor VIII:C from the complex. During this event, no Mr 260,000 subunit of VIII:vWF is discernible. However, prolonged reduction results in the appearance of different multimers, and of some Mr 260,000 subunits. An N-terminal amino acid sequence for VIII:vWF was deduced. Two half-cystine residues in this sequence were shown to be involved in the reaction with thioredoxin. It appears possible that the thioredoxin system or other redox systems may play a role in regulation of factor VIII activities and of hemostatic processes in vivo.

Patient-doctor communication on smoking and drinking: lifestyle in medical consultations.

Lifestyles of groups and individuals are significant determinants of the health status of a population. Behaviour with respect to such areas as alcohol, food, drugs, tobacco, physical exercise, etc., correlates with medical and social well-being and are thus on the agenda for modern health care. The present article reports a study of how such lifestyle habits, notably alcohol and tobacco consumption, are addressed in medical consultations. The results indicate that the areas of smoking and drinking are sensitive and that specific communicative strategies are used for introducing these topics and for eliciting information. Smoking habits are addressed in 75% of the consultations and alcohol habits in 30%. In most cases, the information exchanged is shallow and gives only a fragmentary picture of patients' habits. There is little evidence of attempts to influence patients' attitudes and behaviours and the physicians do not contextualise possible relationships between such lifestyle habits and health in the light of their medical knowledge. In this sense, a potentially very influential face-to-face encounter is not used as a vehicle for attempting to eliminate such significant causes of poor health.

Lifestyle discussion in the provision of health care. An empirical study of patient-physician interaction.

The main issue explored is how patients and physicians communicate about lifestyle in the clinical encounter and what role this talk plays in terms of the outcome of the consultation. The data, collected at two primary health care centers, consist of 42 audiorecorded consultations. The analyses are based on these transcribed dialogues. Our study shows that communication about lifestyle issues is used as a source for determining what health care measures are relevant. Physicians provided a variety of types of information and explicit connections were made between lifestyle and the medical problem by physicians as well as patients. Within the process of reaching decisions on advice or treatment, two forms of interaction appeared referred to here as "paternalism" and "mutuality". In general, the results show that the physicians are very cautious about making explicit medical inferences concerning specific issues of the individual's lifestyle.

Patient involvement in decision-making in surgical and orthopaedic practice: the Project Perioperative Risk.

As part of the Project Perioperative Risk (PROPER), which is a clinical and epidemiological study of surgical complications, patient involvement in the decision to operate was evaluated by means of a questionnaire. The sample of 666 patients, on the waiting list for an operation, received a questionnaire on a broad range of issues concerning their involvement in the decision-making process one week before the operation. The results show that 41% regarded the decision to have an operation as a joint patient-doctor decision, in 29% of the cases the doctor advocated an operation and in 8% the patient asked to be operated. A clear majority, 73% felt involved in the decision-making as much as they wished. Two groups--women and immigrants from non-European countries--were least satisfied with their involvement and they also found the decision more difficult to make. In the discussion, it is argued that the comparatively high degree of patient satisfaction with involvement in the decision-making process cannot be taken as evidence of a high level of influence in an absolute sense. In a normative perspective--and considering the fact that the increased responsibility of the health sector is aimed at involving patients in decision-making in health matters--patient satisfaction can just as well be understood as resulting from low expectations with respect to one's own influence. The results also indicate that patient's information needs when facing surgery relate to three issues; possible complications, precise nature of the operation as such, and nature and consequences of anaesthetic procedures.

Addressing life style in primary health care.

The problem studied concerns how patients and physicians talk about and make use of information regarding patient life style in the daily practice of primary health care. The study has been carried out at two primary health care centers in central Sweden. Transcribed dialogues between 42 patients and 12 physicians have been used as a data corpus. The analyses concern the interactional patterns in the dialogues between patient and physician, how the interlocutors address life style and for what purposes. The results show a similarity between patients and physicians with respect to the extent to which they use the discourse space. However, salient differences were found in the following way: the physicians not only introduced and closed life style topics more frequently than the patients did, they also used what is referred to as an agenda driven strategy to introduce them. The patients, on the other hand, used an interactively anchored strategy. The patients, by taking the reference in the life world and by making use of the life style topics, present and articulate their identity. The physicians subsume life style issues under a medical framing of the patients' problem and they mainly address life style in order to construe a proto-typical patient rather than an individual.

Lifestyle in primary health care discourse.

This study is the first part of the project "Lifestyle Questions in Primary Health Care". The study aims at exploring how lifestyle enters into the health care discourse and what significance such factors are given in the clinical work. The particular problem thus concerns the extent to which lifestyle issues are brought up and attended to in the clinical encounters as well as in the medical records. The study was performed at two primary health care centres in central Sweden. The analyses are based on 42 transcribed consultations and on the medical records produced on the basis of these dialogues. The results show that lifestyle issues are given considerable attention in the primary health care encounter. Roughly one third of the discourse space is devoted to these kinds of topics, and the patients and doctors share the discourse space equally between them. There is also a high consistency between topics given space in the discussion and those that are entered into the medical records. The results also point to what could be conceived as a common discursive code between the health centres studied, indicating that there are similar communicative strategies for discussing lifestyle issues.

Partial amputation of the foot for diabetic or arteriosclerotic gangrene. Results and factors of prognostic value.

One hundred and eighty-three conservative amputations of some part of the foot in 161 patients with gangrene from diabetes or arteriosclerosis have been studied retrospectively. They constituted 48 per cent of all amputations in one orthopaedic service over a period of twelve years, during which the minimal feasible procedure was always chosen. Sixty per cent healed soundly, but in over a third of these cases at least one revision to a higher level on the foot had been required. Factors that significantly influenced the outcome of the initial operation were the level of amputation, the age of the patient, the interval between the onset of gangrene and operation, anaemia and pyrexia.

An interview study of men discovering testicular cancer.

Testicular cancer affects men between 15 and 45 years old. The aim of this study was to show how men with testicular cancer discover their cancer, react to physical changes, and take action. In the follow-up phase, 21 who had undergone surgery for testicular cancer were interviewed. The results show clearly that the men focus on their physical pain. The progress from the discovery of changes in the testicular glands to medical care can be divided into three phases. In the first phase, "something has happened," the men consider the changes and try to define the reasons. In the second phase, "facing the situation," they consider the situation and decide whether to talk to someone. In the third phase, "seeking medical help," it is a question of seeking help and being confronted by the medical diagnosis. In terms of time, the progression in the current study took from 1 day to 1 year. The men sought help when complications arose that made normal daily functions difficult. Six of the men suspected that the cause of their problems was cancer. Almost half of the participants in this study, including the six who suspected cancer, did not talk to anyone before they decided to seek medical help. The men who did talk to other people did not seek medical help any more quickly than the other men. None of the men routinely inspected their bodies.

Intravenous hydroxyethylrutosides combined with long-term oral anticoagulation in atherosclerotic nonreconstructable critical leg ischemia: a retrospective study.

OBJECTIVE: To evaluate in a group of seriously diseased patients with nonreconstructable chronic critical leg ischemia (CLI), treated by a combination of i.v. hydroxyethylrutosides (HR)* and oral anticoagulation (AC) by warfarin, the short-term effects on the cutaneous microvascular blood perfusion of the soles of feet and especially the long-term clinical outcome in terms of amputation and death. DESIGN: A retrospective comparison between two groups of patients, HR + AC and a comparable reference group, fulfilling the same inclusion and exclusion criteria corresponding to the definition of CLI according to the Second European Consensus Document (1991). Clinical follow-up in both groups was made after 1, 3, 6, 12, and 24 months. SETTING: Patients were examined at university departments of clinical physiology with special interest in peripheral vascular disease, in cooperation with colleagues at university departments of surgery, internal medicine and dermatology of Karolinska Hospital, Södersjukhuset and Huddinge Hospital. PATIENTS: A total of seventy patients with CLI according to the definition of the Second European Consensus Document, 1991, ie, besides severe rest pain or ischemic lesions also a toe blood pressure < 30 mg Hg. Group with HR + anticoagulation (AC): 42 patients (19 diabetics, 23 nondiabetics). Reference group: 28 patients (18 diabetics, 10 nondiabetics). For distribution of age and toe blood pressure at baseline, see Table I. INTERVENTIONS: Therapy group: besides ordinary standard therapy, daily HR infusions for a mean period of 3.6 weeks + oral anticoagulation continued to the end of the study at 24 months. A comparable reference group on the same basic therapy but without the combination HR + AC. PARAMETERS IN EVALUATION: Short-term parameters: clinical data, skin temperature, and fluorescein imaging. Long-term outcome: amputation or death. RESULTS: Short-term and long-term results with HR + AC indicated that patients with severe CLI and very poor prognosis benefited in terms of survival and limb salvage from initial therapy with HR infusion combined with long-term oral anticoagulation. Results of this combined treatment seem at least comparable with those with i.v. prostacyclin analogies.

Fibrin gels as biological filters and interfaces.

We present data which show that fibrin gels are ordered network structures, the porosity of which is determined by the amount of thrombin being present during the activation step preceding gelation. On activation of fibrinogen, fibrinopeptides are released and simultaneously polymers are formed, obeying apparent first order kinetics. The pore size of the network is inversely related to the rate of polymer formation. It is proposed that at the time of gelation the polymers form an ordered lattice structure, which in the organism may serve as a biological interface.

Nitrogen and the Baltic Sea: managing nitrogen in relation to phosphorus.

The Baltic is a large, brackish sea (4 x 10(5) km2) extending from 54N to approximately 66N, with a fourfold larger drainage area (population 8 x 10(7). Surface salinity (2 to 8 PSU) and hence biodiversity is low. In the last century, annual nutrient loads increased to 10(6) metric tons N and 5 x 10(4) ton P. Eutrophication is evident in the N-limited south, where cyanobacteria fix 2 to 4 x 10(5) ton N each summer, Secchi depths have been halved, and O2-deficient bottom areas have spread. Production remains low in the P-limited north. In nutrient-enriched coastal areas, phytoplankton blooms, toxic at times, and filamentous macroalgae reduce amenity values. Loads need to be reduced of both N, to reduce production, and P, to limit N-fixing cyanobacterial blooms. When large N-load reductions have been achieved locally, algal biomass has declined. So far, P loads have been reduced more than N loads. If this continues, a P-limited Baltic proper may result, very different from previous N-limited conditions. Reaching the management goal of halved anthropogenic N and P loads at minimum cost will require better understanding of biogeochemical nutrient cycles, economic evaluation of proposed measures, and improved stakeholder participation.

Rehabilitation of long-term sick-listed patients in Sweden through techniques of sports medicine.

Sweden has seen a sharp increase in sick-listing recently. A new rehabilitation programme was tested for patients with musculoskeletal pain applying the experiences from sports injury rehabilitation. In this programme, the danger of inactivity was emphasised, and the staff accepted that the process of restoring physical fitness may be accompanied by a temporary increase in pain. During an 11 month period, 101 patients began a 4-week rehabilitation programme. This programme was in action 5 days a week from 9AM to 4PM. Six patients broke off the programme. The remainder were called back for a follow-up 6 months later, a total of 83 patients attending. This follow-up showed that only 22% benefit. Significantly more men than women returned to work. After rehabilitation the patients perceived better health and their living habits normalized. In patients sick-listed for long periods, an intensive period of exercise based largely on sports medicine can lead to return-to-work, also in Sweden.

Age and gender differences in VO2max in Swedish obese children and adolescents.

AIM: To describe age and gender differences in estimated maximum oxygen uptake (VO2max) and participation in organized physical activity in Swedish obese children and adolescents, and compare the results with an age-matched reference group representative of the general population. METHODS: Two hundred and nineteen obese children (102 boys, 117 girls, aged 8-16 years, Body Mass Index (BMI) 24.3-57.0 kg.m-2) performed a submaximal bicycle ergometry test and an interview concerning participation in organized physical activity. RESULTS: The obese children had lower relative VO2max (p<0.001) than the reference group. In contrast to the reference group no age or gender differences were detected in the obese children aged 11-13 years and 14-16 years. With increased age (after 11 years) the obese children participated less in organized physical activity than the reference group (p<0.001). In obese adolescents, participation in organized physical activity in leisure time explained 7% and BMI 45% of the variance in relative VO2max. CONCLUSION: The obese children had lower relative VO2max, and participated less in organized physical activity than the reference group. The variance in relative VO2max was primarily explained by BMI. Obese adolescents, especially boys, were found to be at risk of physical inactivity.