Spat production of the great scallop (Pecten maximus): a roller coaster1This review is part of a virtual symposium on current topics in aquaculture of marine fish and shellfish

The great scallop ( Pecten maximus (L., 1758)) has been of interest for aquaculture in Europe since the early 1970s. Since then, a large part of the research and development has focussed on reproduction and early life stages to support hatchery production of spat. Results from the last two decades show that production stability is lacking and have followed a roller-coaster trend. Production strategy varies, but in general, broodstock are collected from the wild and conditioned to gonad maturity sufficient for successful spawning. Natural reproduction cycle varies between populations, which is a challenge to hatcheries aiming at stable year-round production. Larval survival was for many years dependent on addition of antibiotics until a flow-through culture was established, and seasonal variation may be caused by variation in gamete or seawater quality. Settlement, metamorphosis, and spat growth depend on healthy larvae and appropriate culture environment. For efficient spat production, the use of land-based nurseries is promising. Results show that mean yield of spat from eggs is less than 1%. The review concludes that the gap between results obtained in hatchery production and in experiments shows a great potential for production increase.

Diagnosing intramammary infections: evaluation of definitions based on a single milk sample

Criteria for diagnosing intramammary infections (IMI) have been debated for many years. Factors that may be considered in making a diagnosis include the organism of interest being found on culture, the number of colonies isolated, whether or not the organism was recovered in pure or mixed culture, and whether or not concurrent evidence of inflammation existed (often measured by somatic cell count). However, research using these criteria has been hampered by the lack of a "gold standard" test (i.e., a perfect test against which the criteria can be evaluated) and the need for very large data sets of culture results to have sufficient numbers of quarters with infections with a variety of organisms. This manuscript used 2 large data sets of culture results to evaluate several definitions (sets of criteria) for classifying a quarter as having, or not having an IMI by comparing the results from a single culture to a gold standard diagnosis based on a set of 3 milk samples. The first consisted of 38,376 milk samples from which 25,886 triplicate sets of milk samples taken 1 wk apart were extracted. The second consisted of 784 quarters that were classified as infected or not based on a set of 3 milk samples collected at 2-d intervals. From these quarters, a total of 3,136 additional samples were evaluated. A total of 12 definitions (named A to L) based on combinations of the number of colonies isolated, whether or not the organism was recovered in pure or mixed culture, and the somatic cell count were evaluated for each organism (or group of organisms) with sufficient data. The sensitivity (ability of a definition to detect IMI) and the specificity (Sp; ability of a definition to correctly classify noninfected quarters) were both computed. For all species, except Staphylococcus aureus, the sensitivity of all definitions was <90% (and in many cases<50%). Consequently, if identifying as many existing infections as possible is important, then the criteria for considering a quarter positive should be a single colony (from a 0.01-mL milk sample) isolated (definition A). With the exception of "any organism" and coagulase-negative staphylococci, all Sp estimates were over 94% in the daily data and over 97% in the weekly data, suggesting that for most species, definition A may be acceptable. For coagulase-negative staphylococci, definitions B (2 colonies from a 0.01-mL milk sample) raised the Sp to 92 and 95% in the daily and weekly data, respectively. For "any organism," using definition B raised the Sp to 88 and 93% in the 2 data sets, respectively. The final choice of definition will depend on the objectives of study or control program for which the sample was collected.

Is neuropathic pain underdiagnosed in musculoskeletal pain conditions? The Danish PainDETECTive study

In all, 19-22% of the adult Danish population suffer from chronic pain - most frequently in the musculoskeletal system. Different pain management strategies depending on pain mechanism (neuropathic/nociceptive) make diagnosing the pain condition especially important.

OBJECTIVES

To investigate whether a validated, self-administered questionnaire (PainDETECT) helps specialists and general practitioners in Denmark identify patients with neuropathic pain components (NeP).

RESEARCH DESIGN AND METHODS

In a non-interventional study a sample of Danish specialists (rheumatologists and anaesthesiologists) and general practitioners used the PainDETECT questionnaire on 1322 chronic pain patients. PainDETECT was filled in by patients and scored by the physician. A PainDETECT score above 18 indicates the presence of NeP.

RESULTS

A total of 87-95% of the included chronic pain patients (702 by specialists (mean age: 56 years) and 620 by general practitioners (mean age: 55 years)) had musculoskeletal pain. In 39-43% of these patients NeP components were present as assessed by PainDETECT (score 21.1-21.7). One-third of the 540 NeP patients (31-36%) had their pain diagnosis reclassified from a non-NeP to a predominant/mixed NeP diagnosis after use of PainDETECT.

CONCLUSIONS

Neuropathic pain seems to be underdiagnosed in musculoskeletal pain conditions. Use of the PainDETECT instrument may be of help to general practitioners and specialists when diagnosing NeP in chronic pain patients. However, the fact that no neurologists were included, together with the limited sample size, with large variations in the number of patients each physician included, as well as the lack of a strict consecutive recruitment process are study limitations.

Aldosterone synthase (CYP11B2)­344T/C polymorphism and renoprotective response to losartan treatment in diabetic nephropathy

OBJECTIVE

It has been suggested that an aldosterone synthase gene polymorphism (CYP11B2 -344T/C) is predictive of the blood pressure lowering effect of angiotensin II receptor blockers in essential hypertension. We investigated whether this polymorphism is predictive of reductions in blood pressure and albuminuria and preservation of glomerular filtration rate (GFR) during short-term and long-term treatment with losartan in 57 hypertensive type-1 diabetic patients with diabetic nephropathy.

MATERIAL AND METHODS

After a 4-week washout period, patients received losartan (100 mg o.d.) and were followed for a mean follow-up of 36 months. At baseline, after 2 and 4 months, and every 6 months thereafter, GFR (51Cr-EDTA-clearance), albuminuria and 24-h blood pressure were determined. The CYP11B2 -344T/C polymorphism was determined by standard polymerase chain reaction (PCR).

RESULTS

The TT, CT and CC genotypes were found in 28 %, 58 % and 14 % of patients, respectively. At baseline albuminuria and blood pressure did not differ between genotype groups. Plasma aldosterone levels (geometric mean (95 % CI)) were similar at baseline: 87 (60-125), 77 (53-112), and 89 (49-161) pg mL(-1) and during follow-up (not significant). After initiation of losartan treatment, comparable mean (SE) reductions in blood pressure and albuminuria were seen in patients with TT, CT and CC genotypes (p >0.6 between groups). After long-term follow-up, there was a tendency towards a difference in systolic blood pressure reduction (p = 0.07, one-way ANOVA), suggesting a poorer response in patients with the CC genotype. No significant difference in rate of decline in GFR (median (range)) was seen between groups (TT, CT, CC): 4.2 (-1.0 to 16.0), 3.2 (-1.6 to 13.8) and 2.6 (-0.1 to 11.0) mL min(-1)year(-1), respectively (p = 0.5).

CONCLUSIONS

Compared to a previous smaller study of angiotensin II receptor blockade in essential hypertension, we could not confirm that CYP11B2 -344T/C genotypes contribute towards explaining the observed variability in response to treatment with angiotensin II receptor blockers, which could be due to lack of power.

Effect of haemodilution, acidosis, and hypothermia on the activity of recombinant factor VIIa (NovoSeven)

Background

A range of plasma volume expanders is used clinically, often in settings where haemostasis may already be impaired. The haemostatic agent, recombinant activated factor VII (rFVIIa, NovoSeven^®), may be used to improve haemostasis but potential interactions with different volume expanders are poorly understood.

Methods

Clot formation was measured by thromboelastography (TEG) using blood from healthy volunteers. In vitro effects of rFVIIa with haemodilution, acidosis, and hypothermia were examined. Conditions were induced by dilution with NaCl (0.9%), lactated Ringer's solution, albumin 5%, or hydroxyethyl starch (HES) solutions [MW (molecular weight) 130–670 kDa]; by adjusting pH to 6.8 with 1 M HEPES (N-2-hydroxyethylpiperazine-N′-2-ethanesulphonic acid) buffer; or by reducing temperature to 32°C. We also studied the effect of low vs high MW HES (MW 200 vs 600 kDa) and rFVIIa on in vivo bleeding time (BT) in rabbits.

Results

Haemodilution progressively altered TEG parameters. rFVIIa improved TEG parameters in the presence of acidosis, hypothermia or 20% haemodilution (P<0.05). At 40% haemodilution, the rFVIIa effect was diminished particularly with high MW HES. In vivo, rFVIIa shortened the BT (P<0.05) with low but not high MW HES.

Conclusions

Efficacy of rFVIIa was affected by the degree of haemodilution and type of volume expander, but not by acidosis or hypothermia.

Multiple cytokine and acute-phase protein gene transcription in West Greenland sledge dogs (Canis familiaris) dietary exposed to organic environmental pollutants

Exposure levels of persistent organic pollutants, such as polychlorinated biphenyls and DDTs, are high in Arctic apex predators and Inuit peoples and are suspected to have negative impacts on their immune systems. We conducted a controlled generational study on liver tissue and ethylenediaminetetraacetic acid blood cytokine and acute-phase protein (APP) mRNA expressions using reverse transcriptionase-polymerase chain reaction in West Greenland sledge dogs (Canis familiaris); contaminated minke whale (Balaenoptera acutorostrata) blubber serves as dietary pollutant source. Two of seven blood cytokine expressions (IL-6 and IL-12) and three of five APP expressions (haptoglobin [HP], heat shock protein, and fatty acid-binding protein [FABP]) were lowest in the exposed group, whereas the remaining five blood cytokine expressions (IL-2, IL-10, IFN-gamma, TNF-alpha, and TGF-beta) and two APP expressions (MT1 and MT2) were highest in the exposed group. In liver tissue, three cytokine expressions (IL-10, IFN-gamma, and TNF-alpha) and two APP expressions (MT1 and MT2) were highest in the exposed group, and the remaining cytokine and APP expressions were lowest in the exposed group. Of these, the liver tissue expression of HP and FABP was significantly lowest in the exposed group (both p < 0.05). As a consequence of our findings, we suggest that a daily intake of 50 to 200 g polluted whale blubber is associated with a genotoxic decrease in HP and FABP gene expression in the liver of sledge dog and possibly of other top mammalian marine predators and consumers in the Arctic, indicating a restricted acute-phase reaction and insufficient immune response. Finally, HP and FABP liver expression appear to be new and sensitive biomarkers of organohalogen compound exposure.

Feature-selective attention enhances color signals in early visual areas of the human brain

We used an electrophysiological measure of selective stimulus processing (the steady-state visual evoked potential, SSVEP) to investigate feature-specific attention to color cues. Subjects viewed a display consisting of spatially intermingled red and blue dots that continually shifted their positions at random. The red and blue dots flickered at different frequencies and thereby elicited distinguishable SSVEP signals in the visual cortex. Paying attention selectively to either the red or blue dot population produced an enhanced amplitude of its frequency-tagged SSVEP, which was localized by source modeling to early levels of the visual cortex. A control experiment showed that this selection was based on color rather than flicker frequency cues. This signal amplification of attended color items provides an empirical basis for the rapid identification of feature conjunctions during visual search, as proposed by "guided search" models.

Cold adaptation and thyroid hormone metabolism

Resting oxygen consumption and energy expenditure is sensitive to slight alterations in thyroid function. This means that timing and magnitude of cold adaptation would to some extent depend on thyroid function. Local thyroid hormone metabolism is important for energy expenditure and dissipation of heat in special tissues. Recruitment of brown adipocytes and upregulation of uncoupling protein 1 in mitochondria depends on high tissue T3 concentrations. Most of this T3 is derived from local 5' deiodination of T4. Brown fat is vital for cold exposed mice and rats, and may be important for temperature adaptation in human neonates. The role of thyroid hormone metabolism in adult human cold adaptation has not been finally clarified. Hypothetically, cold exposure may enhance T3 production by deiodination of T4 in skeletal muscle, which may enhance heat production in muscle via a change in muscle fiber type. Another hypothetical possibility is recruitment of brown adipocytes embedded in white adipose tissue in human adults. Understanding cold adaptation in human adults may lead to development of new drugs against obesity.

Aldosterone escape during blockade of the renin-angiotensin-aldosterone system in diabetic nephropathy is associated with enhanced decline in glomerular filtration rate

AIMS/HYPOTHESIS

It has been suggested that aldosterone plays a role in the initiation and progression of renal disease independently of arterial blood pressure and plasma angiotensin II levels. We evaluated the influence of plasma aldosterone levels on progression of diabetic nephropathy during long-term blockade of the renin-angiotensin-aldosterone system.

METHODS

A total of 63 hypertensive patients with type 1 diabetes and diabetic nephropathy were treated with losartan, 100 mg once daily, for a mean follow-up period of 35 months. Plasma aldosterone, GFR, albuminuria and 24-h blood pressure were determined at baseline and at regular intervals during the study.

RESULTS

Patients were divided according to their increasing or decreasing levels of plasma aldosterone during long-term losartan treatment in an escape group (n=26) and a non-escape group (n=37). In the escape group, aldosterone levels increased from (geometric mean [95% CI]) 57 pg/ml (43-76 pg/ml) at 2 months, to 102 pg/ml (78-134 pg/ml) at the end of the study (p<0.01). The corresponding levels in the non-escape group were 83 pg/ml (69-102 pg/ml) and 49 pg/ml (40-60 pg/ml; p<0.01). The median rate of decline in GFR was 5.0 ml.min(-1).year(-1) (range 0.4-15.9 ml.min(-1).year(-1)) in the escape group, compared with 2.4 ml.min(-1).year(-1) (-1.6 to 11.0 ml.min(-1).year(-1)) in the non-escape group (p<0.005). The increase in plasma aldosterone correlated with the rate of decline in GFR (r(2)=0.19, p<0.001), corresponding to a decline in GFR of 1.5 ml.min(-1).year(-1) for every two-fold increase in plasma aldosterone. Pre-treatment and treatment values of plasma aldosterone were not related to albuminuria or to changes in albuminuria during the study.

CONCLUSIONS/INTERPRETATION

Our data suggest that aldosterone escape during long-term blockade of the renin-angiotensin-aldosterone system is associated with an enhanced decline in GFR in patients with type 1 diabetes and diabetic nephropathy.

Respiratory syncytial virus infection--risk factors for hospital admission: a case-control study

Most infants are infected with respiratory syncytial virus (RSV) during the first 2 y of life. The majority have only a mild upper respiratory tract infection, but 1-2% develop a more severe illness and are admitted to hospital.

AIM

To carry out a study of risk factors for hospital admission because of RSV infection in Denmark in children aged less than 2 y of age.

METHODS

The study population included all 1252 children admitted to hospital with verified RSV infection in two Danish counties during the 5-y period 1990-1994. The investigation comprised a retrospective case-control study with five matched controls per case. In a multivariate analysis the risk factors included medical and demographic variables, and in infants <3 mo of age at hospitalization, two aspects of innate immunity: mannose-binding lectin (MBL) concentration and maternal RSV serum antibody titre, measured on eluates from stored dried blood from the infants' 4th day of life. The effect of each risk factor is expressed as an odds ratio, corresponding to the relative risk of being a case rather than a control if the risk factor is present.

RESULTS

The following independent risk factors were identified: age, sex, month of birth, gestational age, birthweight, presence of a sibling, up to 5 y older than the case, and maternal smoking during pregnancy. There was a marginal effect of maternal RSV antibody levels, but no effect of neonatal serum MBL concentration or of crowding in the household.

CONCLUSIONS

Ninety percent of cases and 80% of controls had one or more risk factors. Even though several factors were found to increase the risk for hospitalization for RSV disease, all the effects were small and no single specific factor could be identified to explain the hospitalization of the minority of children with RSV infection.

Inuit health in Greenland: a population survey of life style and disease in Greenland and among Inuit living in Denmark

During 1997-2001 a population survey was carried out amongst Greenland Inuit living in Denmark and West Greenland (Nuuk, Sisimiut, Qasigiannguit and four villages in Uummannaq municipality). Data collection comprised an interview, a questionnaire, clinical examinations and sampling of biological specimens (blood, urine, subcutaneous fat tissue). The clinical examinations included anthropometric measurements, an oral glucose tolerance test, ECG, ultrasound of thyroid gland and carotid arteries, a skin prick test, and lung function. The data collection areas in Greenland ranged from the westernized capital of Nuuk (pop. app. 13,000) to small fishing and hunting villages (pop. app. 250). A total of 4,162 persons aged 18+ participated in the study; clinical examinations were performed on 2,056 of these, 739 from Denmark and 1317 from Greenland. Some of the above mentioned procedures were performed on a subset of the participants. The participation rate was 62%. We provide an overview of the background of the study and a detailed description of the methods employed for the data collection. A set of standard tables are provided for the indigenous population of Greenland. These cover statistics for selected variables by gender and ten-year age groups.

Decreasing overweight and central fat patterning with Westernization among the Inuit in Greenland and Inuit migrants

OBJECTIVE

To analyse overweight, obesity and central fat patterning among the Inuit of Greenland and Inuit migrants in Denmark and their relation to Westernization.

DESIGN

Cross-sectional, population-based epidemiological study.

SUBJECTS

A total of 2046 adult Greenlanders (Inuit), 61% of those invited to participate, living in three areas of Greenland and in Denmark.

MEASUREMENTS

Height, weight, waist and hip circumferences were measured and body mass index (BMI in kg/m(2)) and waist-hip ratio calculated. Sociocultural information was obtained by questionnaire and interview. Westernization was estimated by language and place of residence.

RESULTS

The prevalence of obesity (>or=30 kg/m(2)) was 16 and 22% among men and women in Greenland (P=0.004), and 12 and 11%, respectively, in Denmark (NS). Westernization was accompanied by a decrease in the proportion of obese people, in particular among women. Adjusted for BMI, age and Inuit heritage waist circumference decreased with Westernization (among women), while hip circumference did not change. The differences were particularly pronounced for migrants compared with residents of Greenland.

CONCLUSION

BMI and central fat patterning decrease with Westernization among Greenland Inuit women contrary to most studies of migrants. The changes were less prominent among men. This suggests a reduced cardiovascular risk profile with Westernization among Greenland Inuit.

Properties and functions of human uracil-DNA glycosylase from the UNG gene

The human UNG-gene at position 12q24.1 encodes nuclear (UNG2) and mitochondrial (UNG1) forms of uracil-DNA glycosylase using differentially regulated promoters, PA and PB, and alternative splicing to produce two proteins with unique N-terminal sorting sequences. PCNA and RPA co-localize with UNG2 in replication foci and interact with N-terminal sequences in UNG2. Mitochondrial UNG1 is processed to shorter forms by mitochondrial processing peptidase (MPP) and an unidentified mitochondrial protease. The common core catalytic domain in UNG1 and UNG2 contains a conserved DNA binding groove and a tight-fitting uracil-binding pocket that binds uracil only when the uracil-containing nucleotide is flipped out. Certain single amino acid substitutions in the active site of the enzyme generate DNA glycosylases that remove either thymine or cytosine. These enzymes induce cytotoxic and mutagenic abasic (AP) sites in the E. coli chromosome and were used to examine biological consequences of AP sites. It has been assumed that a major role of the UNG gene product(s) is to repair mutagenic U:G mispairs caused by cytosine deamination. However, one major role of UNG2 is to remove misincorporated dUMP residues. Thus, knockout mice deficient in Ung activity (Ung-/- mice) have only small increases in GC-->AT transition mutations, but Ung-/- cells are deficient in removal of misincorporated dUMP and accumulate approximately 2000 uracil residues per cell. We propose that BER is important both in the prevention of cancer and for preserving the integrity of germ cell DNA during evolution.

Ethical guidance on human embryonic and fetal tissue transplantation: a European overview

This article presents an overview of regulations, guidelines and societal debates in eight member states of the EC about a) embryonic and fetal tissue transplantation (EFTT), and b) the use of human embryonic stem cells (hES cells) for research into cell therapy, including 'therapeutic' cloning. There appears to be a broad acceptance of EFTT in these countries. In most countries guidance has been developed. There is a 'strong' consensus about some of the central conditions for 'good clinical practice' regarding EFTT. International differences concern, amongst others, some of the informed consent issues involved, and the questions whether an intermediary organisation is necessary, whether the methods of abortion may be influenced by the possible use of EFT, and whether EFTT should only be used for the experimental treatment of rare disorders. The potential use of hES cells for research into cell therapy has given a new impetus to the debate about (human) embryo research. The therapeutic prospects with regard to the retrieval and research use of hES cells appear to function as a catalyst for the introduction of less restrictive regulations concerning research with spare embryos, at least in some European countries. It remains to be seen whether the prospect of treating patients suffering from serious disorders with transplants produced by therapeutic cloning will decrease the societal and moral resistance to allowing the generation of embryos for 'instrumental' use.