Iron and iron/manganese ratio in forage from Icelandic sheep farms: relation to scrapie.

This study was undertaken in order to examine whether any connection existed between the amounts of iron in forage and the sporadic occurrence of scrapie observed in certain parts of Iceland. As iron and manganese are considered antagonistic in plants, calculation of the Fe/Mn ratios was also included by using results from Mn determination earlier performed in the same samples. Forage samples (n = 170) from the summer harvests of 2001-2003, were collected from 47 farms for iron and manganese analysis. The farms were divided into four categories: 1. Scrapie-free farms in scrapie-free areas (n = 9); 2. Scrapie-free farms in scrapie-afflicted areas (n = 17); 3. Scrapie-prone farms (earlier scrapie-afflicted, restocked farms) (n = 12); 4. Scrapie-afflicted farms (n = 9). Farms in categories 1 and 2 are collectively referred to as scrapie-free farms. The mean iron concentration in forage samples from scrapie-afflicted farms was significantly higher than in forage samples from farms in the other scrapie categories (P = 0.001). The mean Fe/Mn ratio in forage from scrapie-afflicted farms was significantly higher than in forage from scrapie-free and scrapie-prone farms (P < 0.001). The results indicated relative dominance of iron over manganese in forage from scrapie-afflicted farms as compared to farms in the other categories. Thus thorough knowledge of iron, along with manganese, in soil and vegetation on sheep farms could be a pivot in studies on sporadic scrapie.

Polybrominated diphenyl ethers: occurrence, dietary exposure, and toxicology.

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5--30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970--1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972--1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 microg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs). In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 10(6) separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future.

Persistent organochlorine levels in six prey species of the gyrfalcon Falco rusticolus in Iceland.

Our previous investigations have revealed very high levels of organochlorines (OCs) in the Icelandic gyrfalcon Falco rusticolus, a resident top predator. We now examine six potential prey species of birds, both resident and migratory, in order to elucidate the most likely route of the OCs to the gyrfalcon. The ptarmigan Lagopus mutus, the most important prey of the gyrfalcon, contained very low levels of OCs. Bioaccumulation of polychlorinated biphenyls (PCBs) and DDTs in mallards Anas platyrhynchos, tufted ducks Aythya fuligula, golden plovers Pluvialis apricaria, purple sandpipers Calidris maritima, and black guillemots Cepphus grylle reflected their position in the foodchain. The differences in OC-levels seem nevertheless too high just to reflect the different food-chain levels of these species in Iceland. The winter grounds of the migratory golden plovers and tufted ducks appear to be more contaminated than the Icelandic terrestrial habitat of ptarmigans or the freshwater habitat as reflected in mallards, both resident species. However, spending the winter on the coast in Iceland, results in high levels of contaminants in purple sandpipers and black guillemots. Our results indicate OC contamination of the marine ecosystem in Iceland while the terrestrial and freshwater ecosystems are little affected. It is postulated that gyrfalcons receive the major part of the observed contamination from prey other than ptarmigan, especially birds associated with the marine ecosystem and also from migratory birds.

Copper, ceruloplasmin and superoxide dismutase (SOD1) in patients with Down's syndrome.

The aim of this study was primarily to investigate whether similar signs of copper dyshomeostasis occur in dementia with age in Down's syndrome as previously found in Alzheimer's disease. Copper was accordingly determined in plasma, ceruloplasmin concentration in serum, ceruloplasmin oxidative activity and ceruloplasmin specific oxidative activity (activity related to mass) in serum, and superoxide dismutase (SOD1) in erythrocytes in 35 (27 males, 8 females) 18-53 years old (average 37 years) patients with Down's syndrome (Down's patients) and their age- and gender-matched controls. SOD1 activity was on an average almost 50% higher in the patients than in their controls but the evidence of a causal relationship between increased SOD1 activity and Down's syndrome appears at best equivocal. Copper and ceruloplasmin levels and ceruloplasmin activities were similar in the patients and their controls. Ceruloplasmin and copper levels increased significantly with age in the patients but not in the controls. Ceruloplasmin activities or SOD1 activity did not change significantly with age, neither in the patients nor in the controls as whole groups. When SOD1 activity and ceruloplasmin activities of the oldest in the patients group (40 years or older) were compared with those of the younger patients, respectively, SOD1 activity and specific oxidative activity, but not ceruloplasmin oxidative activity were found to decrease significantly with age. The results thus suggest that development of dementia in Down's patients with age is paralleled with decrease in SOD1 activity and specific oxidative activity but not with decrease in ceruloplasmin oxidative activity itself as was also found in Alzheimer's patients.

Copper, ceruloplasmin and superoxide dismutase (SOD) in amyotrophic lateral sclerosis.

In two previous studies we found copper dyshomeostasis in patients with Alzheimer's disease and in patients with Parkinson's disease. In this study, the levels of copper in plasma, of ceruloplasmin in serum, ceruloplasmin oxidative activity, ceruloplasmin specific oxidative activity (activity related to mass) as well as superoxide dismutase (SOD) activity in erythrocytes have been determined in 14 patients with amyotrophic lateral sclerosis and their healthy age- and gender-matched controls. Three of the patients had a familial form of the disease or were suspected of having it. The mean values of all parameters were found not to differ significantly between the patients and their controls (Student's t-test; P>0.05). By testing the equality of variances (F distribution) we found that the variances of individual results for ceruloplasmin specific oxidative activity and SOD activity differed significantly between the patients group and the controls group (P= 0.021 and P=0.003), but the individual results of these two activities were not correlated (P>0.05). We conclude that disturbances in ceruloplasmin specific oxidative activity and SOD activity could contribute to motor neurone death in amyotrophic lateral sclerosis, and since the two enzyme activities are not correlated it is uncertain which one is more closely related to the pathology of the disease.

The effect of irregular feeding times on the behaviour and growth of dairy calves.

The objective of this study was to examine the effects of predictable vs. unpredictable management routines on the behaviour, production and health of dairy calves. Three different feeding schedules for milk-fed dairy calves were compared. All calves received milk twice a day, and had free access to concentrate, hay and water. Three groups of 12 calves (divided on two trials) were exposed to one of the following treatments from the age of 5 days to 9 weeks: group C (control) received milk at the same time every day, at 0700 and 1400. Group OD (occasional deviation) received the milk at the same time every day except on treatment days, one in week 5 and one in week 8, where they were fed 3 h later. Group IR (irregular schedule) received milk at irregular times throughout the experimental period. The first daily feeding took place between 0600 and 1300 and the second one between 1300 and 2100. When the calves were 5 and 8 weeks old, the behaviour of eight calves from each group was videorecorded for two days (48 h). The following behaviour was recorded: frequency and duration of lying bouts and frequency of comfort behaviour (defined as licking or scratching own body), eating, drinking, other oral behaviour and extending the head through the feeding barrier (HTB). The milk and concentrate consumption of the calves was measured and the calves were weighed weekly. Diseases were recorded.The results showed that at the age of 5 weeks, the calves in group IR differed from the control group C by performing more eating behaviour both on the control day (27.5 vs. 15.5; p<0.05) and the treatment day (28.8 vs. 18.3; p<0.05). At the age of 8 weeks, no differences were found in the behaviour between groups IR and C. When the OD calves were 5 weeks old, they responded to the delayed feeding by increasing drinking behaviour (14.5 vs. 9.0; p<0.05). When they were 8 weeks old, they showed increased frequency of comfort (195 vs. 122; p<.05), eating (37.5 vs. 27.9; p<0.05) and HTB behaviour (19.8 vs. 7.4; p<0.001) on the treatment day compared to the control day. The IR group did not respond to the same treatment except for a slight increase in drinking behaviour (9.6 vs. 6.5; p<0.05) at the age of 8 weeks. No differences were observed in the frequency or length of lying bouts, nor health or production parameters between the three groups.It is concluded that a predictable feeding schedule may not be very important for milk-fed dairy calves. However, when the calves are customised to predictable feeding times, occasional deviations from that schedule may cause frustration when their expectations are not fulfilled.

[Aspirin. Acetylsalicylic acid and aspirinlike drugs. A review.].

In this review acetylsalicylic acid and aspirin with little "a" are considered as synonyms. A short acount is given of the history preceeding the synthesis of acetylsalicylic acid from salicylic acid by Felix Hoffmann in 1897 and its marketing in 1899 as Aspirin(R) by the Bayer Company. Aspirin was originally considered a prodrug to salicylic acid since it was at that time thought to have the same pharmacodynamic effects as salicylic acid and is rapidly transformed to it in vivo. Later aspirin was also found to be effective in its own right. During the years aspirin has gradually become the standard drug among an increasing number of aspirinlike drugs having similar effects as aspirin and often collectively, and somewhat misleading, named "nonsteroidal antiinflammatory drugs" (NSAIDs). The seminal work of John Vane and his colleagues in the 1970s and later has irrefutably tied the effects and side effects of aspirin and aspirinlike drugs to blocking of cyclooxigenase activity and therefore to reduced production of prostaglandins and related biogenic lipids. The anticoagulant effect, where aspirin itself is the cardinal drug, is thus due to decreased synthesis of thromboxan, whereas the antipyretic effect is due to reduced synthesis of prostaglandins in the central nervous system. The analgesic effect is obviously both related to decreased synthesis of prostaglandins in the central nervous system and outside it. On the other hand the antiinflammatory effect is seemingly mostly due to blocking inflammatory phenomena, without involvement of cyclooxigenase, in the walls of vessels although blocking the synthesis of prostaglandins also has a role. All aspirinlike drugs have until quite recently been mixed blockers of cyclooxigenases (COX 1 and COX 2) with aspirin itself being the most outstanding COX 1 blocker. New aspirinlike drugs with selective COX 2 blocking effect are apparently not any better on classical indications than the older drugs with mixed COX 1 and COX 2 blocking effect and their use might moreover be limited by some severe side effects. These drugs might, however, become of value for use on new indications.

Copper, ceruloplasmin, superoxide dismutase and iron parameters in Parkinson's disease.

In a previous study we found copper dyshomeostasis in patients with Alzheimer's disease. In this study, levels of copper in plasma, of ceruloplasmin in serum and ceruloplasmin oxidative activity as well as superoxide dismutase (SOD) activity in erythrocytes were determined in 40 patients with Parkinson's disease and their healthy age- and gender-matched controls. Copper concentrations did not differ significantly in the two groups, whereas both ceruloplasmin concentrations and ceruloplasmin oxidative activity were significantly lower in the patients, also relative to ceruloplasmin mass. SOD activity was not significantly different in the two groups but decreased significantly with the duration of disease. The same was found for ceruloplasmin oxidative activity. Ceruloplasmin oxidative activity and SOD activity did not decrease with age. Levels of serum iron, serum ferritin and total iron binding capacity were determined in about 30 of the patients and an equal number of controls and were not found to differ. Transferrin levels were significantly lower in the patients than in their controls but, conversely, the transferrin saturation was significantly higher in the patients. The results indicate that patients with Alzheimer's disease and Parkinson's disease have defective ceruloplasmin and SOD activities in common and that these defects are not necessarily associated with major disturbances in iron homeostasis.

Congenital variant Rett syndrome in a girl with terminal deletion of chromosome 3p.

A girl fulfilling four/five of six inclusion criteria and eight/nine of 11 supportive criteria for atypical Rett syndrome had a cytogenetic deletion of chromosome 3p, del(3)(pter-->3p25.1 approximately 25.2). The deletion was situated on the maternally derived chromosome and by molecular analysis the deletion breakpoint was shown to be between DNA markers D3S3589 and D3S1263.

The two-exon gene of the human forkhead transcription factor FREAC-2 (FKHL6) is located at 6p25.3.

The gene for the human transcription factor forkhead related activator 2 (FREAC-2; HGMW-approved symbol FKHL6) has been characterized and found to consist of two exons separated by an intron of 3.6 kb. The first exon encodes the forkhead DNA-binding domain and one of the transcriptional activation domains, AD2. The second exon contains the coding sequence corresponding to the C-terminal activation domain AD1. The full-length FREAC-2 protein is predicted to be 444 amino acids, which adds 39 amino acids to the previously published partial cDNA sequence. A 2-kb CG island is centered around the 5' end of the FREAC-2 gene. Fluorescence in situ hybridization was used to localize the human FREAC-2 gene to chromosomal position 6p24-p25, and the localization was further refined by radiation hybrid mapping to 6p25.3.

Copper, ceruloplasmin and superoxide dismutase in patients with Alzheimer's disease . a case-control study.

The copper-containing enzyme superoxide dismutase (SOD) is a key enzyme in suppressing the amounts of superoxide anion radicals. Ceruloplasmin, the copper-transporting protein in plasma, also possesses an important redox capacity. In this study the levels of copper and ceruloplasmin as well as SOD-activity and ceruloplasmin oxidative activity were analyzed in order to throw some light on possible defects in copper mechanisms in patients diagnosed with Alzheimer's disease (AD). The study included 44 patients with AD and their healthy age- and gender-matched controls. No difference of significance was seen when comparing the copper or ceruloplasmin concentration in plasma of AD patients to that of their paired controls. The SOD activity in red blood cells was significantly lower in the patients than in their controls (p = 0.019). The ceruloplasmin oxidative activity in plasma of Alzheimer's patients was greatly reduced as compared to that of age- and gender-matched controls and the difference was highly significant (p = 0.0005). Ceruloplasmin activity and SOD activity were not found to be intrinsically correlated. It was postulated that reduced oxidative activity of ceruloplasmin in plasma might be either a cause or a consequence of AD and that reduced SOD activity might further add to the oxidative disturbances in AD due to defective ceruloplasmin activity.

Complex chromosome rearrangement involving chromosomes 1, 4 and 16 revealed by fluorescence in situ hybridization.

A 7-year-old boy with mental retardation had apparently balanced reciprocal translocations, involving the telomeric regions of chromosomes 1p and 4q, which was detected by routine chromosome analysis. Fluorescence in situ hybridization (FISH) was used and also revealed the telomeric region of chromosome 16p to be involved in a still apparently balanced translocation-complex, impossible to discover with classical cytogenetic analysis. We want to emphasize the importance of FISH in detecting small chromosomal aberrations. We discuss whether the abnormal phenotype is caused by unbalanced karyotype with cryptic undetected translocations or small deletions or mutations in the translocation-breakpoints.

Further studies on a male monozygotic triplet with schizophrenia: cytogenetical and neurobiological assessments in the patients and their parents.

We previously described a Swedish set of male schizophrenic monozygotic triplets. In this study the patients as well as their parents were further characterized. By high-resolution chromosomal analysis an extra band at chromosome 15p was found in all the triplets and the father. Microdissection, degenerate oligonucleotide-primed PCR (DOP-PCR) amplification and reverse painting indicates that the extra band probably contains only repetitive DNA sequences with no known effect on the phenotype. Magnetic resonance imaging (MRI) showed similar borderline ventricular enlargement and widened subarachnoid spaces over frontoparietal and basal regions as well as around the pituitary gland (empty sella) in all the triplets. The father also had widened subarachnoid spaces over the frontal and basal regions. The mother had an empty sella indicating widened subarachnoid spaces. All the boys also had a right-sided conductive hearing defect, probably due to malformation and fixation of the ossicular chain. The parents did not present any otological abnormalities. Neuropsychological assessment demonstrated similar marked reductions of attentional, mnestic, and executive functions in all the triplets, but the mother showed a normal pattern. Possible joint etiological mechanisms for the psychological and somatic abnormalities recorded in the triplets are discussed.

[Persistent organochlorines in Icelandic breast milk.].

Persistent organochlorines are passed from a mother to her offspring and can affect his or her growth and development. The levels of persistent organochlorines in breast milk from 22 Icelandic women (18 primiparae and four bisparae) were investigated during the summer of 1993. The samples were collected at the Maternity Department of Landspitalinn, the University Hospital in Reykjavik. Dichloro-diphenyl-dichlorethene (DDE), hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs), were found in all samples but not hexachlorocyclohexane (HCH). No statistical difference was found between primi- and bisparae mothers. The levels found were similar to what has been reported for breast milk in neighbouring countries in recent years and lower than was found in France, Germany, Italy and among Inuits of arctic Canada but higher than was found in mothers from South-Canada and Great Britain. The levels, however, were well below estimated risk levels for infants.

Maternal origin of inv dup(15) chromosomes in infantile autism.

Six male patients with infantile autism and an extra inverted duplicated chromosome 15[inv dup(15)] were reported in a previous study. These patients had four copies of the chromosome region 15pter-q13, or an inv dup(15)(pter-->q13; q13-->pter). In this new study, DNA from the families of four of the patients were analysed using Southern based RFLPs and microsatellite polymorphisms from the region. In all four cases the inv dup(15) chromosome was of maternal origin. Furthermore, the data suggests that it originated in the maternal meiotic process rather than in an early mitosis in the developmental process of the embryo. The extra chromosome contained material from both of the maternally derived 15-chromosomes. Based on the molecular data presented here, a model for the origin of chromosome markers of this type is proposed.

Pharmacokinetics of lignocaine in Icelandic horses after infiltration anaesthesia.

The pharmacokinetics of lignocaine was studied in four Icelandic horses after infiltration anaesthesia. A total of 240 mg of the drug was injected on either side of the left foreleg, over the medial and lateral branches of the palmar nerve. Blood samples were collected up to seven hours after injection and the concentrations of the drug in plasma were determined by gas chromatography/mass spectrometry. The results showed that lignocaine was rapidly absorbed. A mean maximum concentration of 232 ng/ml was observed after 20 minutes. In three of the horses the decline in the plasma concentration of the drug with time was best described by the sum of two exponential terms, but in one of the horses the decline was monoexponential. The mean half-life of the distribution phase (alpha) was 9.8 minutes and that of the elimination phase (beta) 48.4 minutes. In all the horses the plasma concentration was below the limit of detection (2 ng/ml) six hours after injection. Anaesthesia was tested in one horse and lasted for one hour.

The effects of nicotine in dermal plaster on cognitive functions in patients with Alzheimer's disease.

Eighteen patients with probable Alzheimer's disease (NINCDS/ADRDA criteria) participated in a placebo-controlled, double-blind study, with a crossover design. The patients had mild or moderate dementia (MMSE = 20.3 +/- 4.6, range 12-28). The trial consisted of two 4-week periods with a 2-week washout period in between. Nicotine was given in the form of dermal plasters. Most of the patients tolerated the highest doses of 21 mg nicotine/24 h, but some received 14 mg/24 h. The effect was monitored with tests of short-term memory, verbal fluency, attention and psychomotor speed. Nicotine was also determined in the blood. Short-term memory improved significantly after 4 weeks of treatment, both on nicotine and placebo (p < 0.05/p < 0.01). The results of our study thus do not indicate that nicotine applied in the form of dermal plasters is of any significance in the treatment of memory deficits in patient with Alzheimer's disease.