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Biomedical subjects

A Nielsen

Publications and source records attributed to A Nielsen.

At least 19 recordsLinked to original sources

Effect of limited hydrolysis on the interfacial rheology and foaming properties of beta-lactoglobulin A.

Hydrolysis of beta-lactoglobulin (beta-Lg), genetic variant A, using a serine protease specific for glutamic and aspartic acid residues from Bacillus licheniformis (BLP), resulted in improved foam overrun and foam stability. Limited hydrolysis (19-26% hydrolysed beta-Lg) led to a more rapid increase in the viscoelastic properties of air/water interfacial films and a concomitant increase in foam overrun compared with intact beta-Lg, presumably due to increased exposure of hydrophobic areas. The increased exposure did not, however, cause formation of an interfacial layer with increased viscoelastic properties. More extended hydrolysis (86% hydrolysed beta-Lg) resulted in a higher initial overrun than the unhydrolysed sample and the best foam stability. The interfacial elasticity and viscosity, though, was the lowest observed. Thus, high maximum values of these interfacial properties are not necessary prerequisites for formation of a voluminous and stable foam.

Journal Article↗

Dampness in buildings and health. Nordic interdisciplinary review of the scientific evidence on associations between exposure to "dampness" in buildings and health effects (NORDDAMP).

Several epidemiological investigations concerning indoor environments have indicated that "dampness" in buildings is associated to health effects such as respiratory symptoms, asthma and allergy. The aim of the present interdisciplinary review is to evaluate this association as shown in the epidemiological literature. A literature search identified 590 peer-reviewed articles of which 61 have been the foundation for this review. The review shows that "dampness" in buildings appears to increase the risk for health effects in the airways, such as cough, wheeze and asthma. Relative risks are in the range of OR 1.4-2.2. There also seems to be an association between "dampness" and other symptoms such as tiredness, headache and airways infections. It is concluded that the evidence for a causal association between "dampness" and health effects is strong. However, the mechanisms are unknown. Several definitions of dampness have been used in the studies, but all seems to be associated with health problems. Sensitisation to mites may be one but obviously not the only mechanism. Even if the mechanisms are unknown, there is sufficient evidence to take preventive measures against dampness in buildings.

Air Pollution, Indoor↗

Concurrent therapies: a model for collaboration between psychoanalysts and other therapists.

Many psychoanalysts treat individuals who are simultaneously in couples therapy or whose partners are in individual therapy. If such cases stall, some analysts may seek consultation from a colleague, though most have accepted the tacit historical prohibition against communication between therapists treating members of the same family. Experience, however, suggests that a certain form of communication between such therapists can have a powerfully enhancing effect on the concurrent therapies. After a review of the literature, the advantages, disadvantages, and impediments to collaborative cross-communication are examined. A model is then presented for use in ongoing discussion between therapists, and is illustrated with two clinical examples. The proposed model centers on the transference-countertransference configurations within the therapeutic field, and serves as an organizer highlighting areas for discussion.

Adult↗

Fractures of the mandibular condyle. Part 1: patterns of distribution of types and causes of fractures in 348 patients.

This prospective study was designed to record relevant characteristics of mandibular condyle fractures and to evaluate the relationship between these. Data were recorded on sex, age, cause of trauma, level of fracture, dislocation of the mandibular head, dental state and associated fractures of all patients diagnosed in our hospital during the period 1984-1996 with mandibular condyle fractures. Data were analysed in our Computer Department. The sample comprised 348 patients with 444 fractures, and a male:female ratio of 2:1. Traffic accidents were the most common cause: 103 (41%) of the unilateral and 54 (56%) of the bilateral fractures, followed by alleged assault and falls. Low fractures were the most common -n = 314 of 444 (71%). The causes that involved considerable force (traffic accidents and falls) resulted in more dislocations of the mandibular head, more bilateral fractures, a tendency to fractures higher on the condyle and significantly more intracapsular fractures. Absence of molar occlusion also gave more high and fewer low fractures, but played no part in dislocation of the mandibular head from the glenoid fossa.

Adolescent↗

Fractures of the mandibular condyle. Part 2: results of treatment of 348 patients.

This study was designed to record the results of conservative treatment of condylar fractures and to find out if there were any variables that were predictive of complications. Data were analysed in our computer department. During the period 1984-1996, all patients who presented with a fracture of the mandibular condyle and who attended for control examination one year after treatment were recorded at the end of treatment and one year later. The ability to open the mouth, deviation and occlusion were recorded. After one year 45 of the 348 patients (13%) had minor physical complaints such as reduced ability to open the mouth, deviation, or dysfunction. Ten of them (3%) had pain in the joint or muscles or both. Eight patients (2%) had malocclusion, which in seven could be related to dislocation of the condylar head out of the fossa. Five of the eight patients had had bilateral fractures. We conclude that conservative treatment of condylar fractures is non-traumatic, safe, and reliable and in only a few cases may cause disturbances of function and malocclusion. The risk associated with the latter is greatest with bilateral fractures and dislocation of the condylar head from the fossa.

Adolescent↗

Methylmercury neurotoxicity in Amazonian children downstream from gold mining.

In widespread informal gold mining in the Amazon Basin, mercury is used to capture the gold particles as amalgam. Releases of mercury to the environment have resulted in the contamination of freshwater fish with methylmercury. In four comparable Amazonian communities, we examined 351 of 420 eligible children between 7 and 12 years of age. In three Tapajós villages with the highest exposures, more than 80% of 246 children had hair-mercury concentrations above 10 microg/g, a limit above which adverse effects on brain development are likely to occur. Neuropsychological tests of motor function, attention, and visuospatial performance showed decrements associated with the hair-mercury concentrations. Especially on the Santa Ana form board and the Stanford-Binet copying tests, similar associations were also apparent in the 105 children from the village with the lowest exposures, where all but two children had hair-mercury concentrations below 10 microg/g. Although average exposure levels may not have changed during recent years, prenatal exposure levels are unknown, and exact dose relationships cannot be generated from this cross-sectional study. However, the current mercury pollution seems sufficiently severe to cause adverse effects on brain development.

Adult↗

Symbiotic mutants deficient in nodule establishment identified after T-DNA transformation of Lotus japonicus.

Nitrogen-fixing root nodules develop on legumes as a result of an interaction between host plants and soil bacteria collectively referred to as rhizobia. The organogenic process resulting in nodule development is triggered by the bacterial microsymbiont, but genetically controlled by the host plant genome. Using T-DNA insertion as a tool to identify novel plant genes that regulate nodule ontogeny, we have identified two putatively tagged symbiotic loci, Ljsym8 and Ljsym13, in the diploid legume Lotus japonicus. The sym8 mutants are arrested during infection by the bacteria early in the developmental process. The sym13 mutants are arrested in the final stages of infection, and ineffective nodules are formed. These two plant mutant lines were identified in progeny from 1112 primary transformants obtained after Agrobacterium tumefaciens T-DNA-mediated transformation of L. japonicus and subsequent screening for defects in the symbiosis with Mesorhizobium loti. Additional nontagged mutants arrested at different developmental stages were also identified and genetic complementation tests assigned all the mutations to 16 monogenic symbiotic loci segregating recessive mutant alleles. In the screen reported here independent symbiotic loci thus appeared with a frequency of approximately 1.5%, suggesting that a relatively large set of genes is required for the symbiotic interaction.

Crosses, Genetic↗

Localisation of the classical DNA satellites on human chromosomes as determined by primed in situ labelling (PRINS).

The chromosomal localisation and relative amounts in humans of the classical DNA satellites I, II and III have been determined by using the primed in situ labelling reaction with a variety of oligonucleotide primers. The centromeres of seven of the human chromosomes, viz. nos 6, 8, 11, 12, 18, 19 and X, are not identifiably marked by any of the primers. A possible phylogenetic explanation of this is suggested and the possible relationship of the classical satellites to the function of the centromere is discussed.

Chromosome Mapping↗

Immediate obturation of the surgical defect after partial maxillectomy in the endentulous patient.

Closure of the surgical defect immediately after partial maxillectomy is the treatment of choice. The advantages are: maintaining facial contour, rapid re-establishment of speech, swallowing and mastication. A number of methods for the fixation of the immediate obturator in patients without teeth have been described. A new technique is reported where a transnasal wire holds the existing denture in position after partial maxillectomy. The method has been carried out on 7 patients with sino-nasal cancer during the period 1978-1994. The advantages of the technique are that the wire acts as an axis of rotation which together with the sponge in the cavity provide good stability of the denture. There is minimal preoperative laboratory work and simplification in replacing the surgical dressing.

Humans↗

Isolation and measurement of the endogenous cannabinoid receptor agonist, anandamide, in brain and peripheral tissues of human and rat.

Anandamide (arachidonylethanolamide) is a novel lipid neurotransmitter first isolated from porcine brain which has been shown to be a functional agonist for the cannabinoid CB1 and CB2 receptors. Anandamide has never been isolated from human brain or peripheral tissues and its role in human physiology has not been examined. Anandamide was measured by LC/MS/MS and was found in human and rat hippocampus (and human parahippocampal cortex), striatum, and cerebellum, brain areas known to express high levels of CB1 cannabinoid receptors. Significant levels of anandamide were also found in the thalamus which expresses low levels of CB1 receptors. Anandamide was also found in human and rat spleen which expresses high levels of the CB2 cannabinoid receptor. Small amounts of anandamide were also detected in human heart and rat skin. Only trace quantities were detected in pooled human serum, plasma, and CSF. The distribution of anandamide in human brain and spleen supports its potential role as an endogenous agonist in central and peripheral tissues. The low levels found in serum, plasma, and CSF suggest that it is metabolized in tissues where it is synthesized, and that its action is probably not hormonal in nature.

Animals↗

Partial deletion 11q: report of a case with a large terminal deletion 11q21-qter without loss of telomeric sequences, and review of the literature.

We describe the cytogenetic findings and the dysmorphic features in a stillborn girl with a large de novo terminal deletion of the long arm of chromosome 11. The karyotype was 46,XX,del(11)(q21qter). By reviewing previous reports of deletion 11q, we found that cleft lip and palate are most frequently seen in proximal 11q deletions involving 11q21. Telomeric staining using the PRINS technique demonstrated normal telomeric sequences in the deleted chromosome 11.

Chromosome Banding↗

Staining of human telomeres with primed in situ labeling (PRINS).

As described, the PRINS method is a very rapid and reliable way of staining human telomeres. To obtain the maximum frequency of stained telomeres, the primer (CCCTAA)7 should be used, although the average frequency never quite reaches 100%. The frequency is strongly dependent on the age of the individual, being significantly higher in children and newborns than in adults. A difference between the (CCCTAA)7 primer and the complementary primer is demonstrated and a possible explanation is proposed, namely, that gaps in the C-rich strand cause chain elongation termination after the addition of only one dTTP molecule.

Adult↗

[Electromagnetic fields from high-voltage installations and cancer in childhood].

The objective of this population-based case-control study has been to investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field. One thousand seven hundred and seven children under the age of 15 with either leukaemia, a tumour of the central nervous system, or malignant lymphoma diagnosed in 1968-86 were identified in the Danish Cancer Registry and matched with 4788 population controls. Measures of exposure were proximity before and after birth to existing or former 50-400 kV electrical transmission connections and substations and associated historical electromagnetic fields calculated on the basis of current load on line, phase ordering of line, and distance from the dwelling. A significant association was seen between all major types of childhood cancer combined and exposure to magnetic fields from high voltage installations of > or = 0.4 microT (odds ratio 5.6). At > or = 0.25 microT no significant association was seen (odds ratio 1.5). A possible association was also seen with cases of Hodgkin's disease separately at > or = 0.1 microT. On the basis of these results and additional descriptive data on electricity consumption and incidence of childhood cancer in Denmark since the 1940s it was concluded that the proportion of childhood cancer possibly caused by 50 Hz electromagnetic fields must be small.

Central Nervous System Neoplasms↗

Epidemiology of pertussis in Denmark: the impact of herd immunity.

BACKGROUND: An evaluation is presented of the Danish pertussis immunization programme, which consists of three injections of plain whole-cell pertussis vaccine given alone at ages 5 weeks, 9 weeks, and 10 months. DATA: The incidence of pertussis in vaccinated and unvaccinated children since the start of vaccination was obtained from the notification system for infectious diseases. Data for vaccination coverage were obtained from the National Social Security. The data for 1980-1986 were supplemented with data from culture-verified cases and hospitalized cases. RESULTS: Compared with other countries using four injections, incidence rates in Denmark are high, especially in pre-school years, leaving infants at a relatively high risk for contracting pertussis from siblings. However, compared with the era before general vaccination, the incidence of pertussis has fallen to one-sixteenth of its former levels. Today, only one in 20 vaccinated, and one in six unvaccinated children develop pertussis before the age of 15 years. This considerable fall, which has also occurred among unvaccinated children, is used to elucidate the importance of herd immunity, which, with the relatively high vaccination coverage in Denmark, was found to play a major role. CONCLUSIONS: The importance of herd immunity is stressed, and it is recommended that a fourth injection of pertussis vaccine is introduced to bring incidence rates down to the very low values found in countries with more intensive vaccination programmes.

Adolescent↗

[Epidemiology of infectious diseases--analysis of an increase of infectious hepatitis in Hamburg].

In Hamburg, the incidence of reported cases of infectious hepatitis more than doubled from 1990 to 1991. The increase refers to hepatitis A, B and other forms of hepatitis. The seven public health offices and the local ministry for health, works and social affairs in Hamburg have analysed the development in a computer-based retrospective study comparing the 1990 and 1991 data. The predominantly affected age group of hepatitis A shifted from childhood to young adulthood. The importance of travelling to acquire hepatitis A was less than expected. In all forms of hepatitis the large number of IV-drug users and prisoners was striking.

Adolescent↗

Residence near high voltage facilities and risk of cancer in children.

OBJECTIVE: To investigate whether residence before and after birth near 50 Hz high voltage installations increases a child's risk of cancer and whether risk correlates with the strength of the magnetic field. DESIGN: A population based case-control study. SETTING: Denmark. SUBJECTS: 1707 children under the age of 15 with leukaemia, tumour of the central nervous system, or malignant lymphoma diagnosed in 1968-86 and 4788 children taken from the central population register. MAIN OUTCOME MEASURES: Proximity before and after birth to existing or former 50-400 kV electrical transmission connections and substations and associated historical electromagnetic fields calculated on the basis of current load on line, phase ordering of line, and distance from the dwelling. RESULTS: A significant association was seen between all major types of childhood cancer combined and exposure to magnetic fields from high voltage installations of > or = 0.4 microT (odds ratio 5.6). At > or = 0.25 microT no significant association was seen (odds ratio 1.5). A possible association was also seen with cases of Hodgkin's disease separately at > or = 0.1 microT. CONCLUSIONS: On the basis these results and additional descriptive data on electricity consumption and incidence of childhood cancer in Denmark since the 1940s it was concluded that the proportion of childhood cancer possibly caused by 50 Hz electromagnetic fields must be small.

Adolescent↗