Biomedical subjects

E Jacobsen

Publications and source records attributed to E Jacobsen.

At least 19 recordsLinked to original sources

PubMed2005

Successful development of a shed-microspore culture protocol for doubled haploid production in Indonesian hot pepper (Capsicum annuum L.).

Various systems of anther and microspore cultures were studied to establish an efficient doubled haploid production method for Indonesian hot pepper (Capsicum annuum L.). A shed-microspore culture protocol was developed which outperformed all the previously reported methods of haploid production in pepper. The critical factors of the protocol are: selection of flower buds with more than 50% late unicellular microspores, a 1 day 4 degrees C pretreatment of the buds, followed by culture of the anthers in double-layer medium system for 1 week at 9 degrees C and thereafter at 28 degrees C in continuous darkness. The medium contained Nitsch components and 2% maltose, with 1% activated charcoal in the solid under layer and 2.5 muM zeatin and 5 muM indole-3-acetic acid in the liquid upper layer. All the ten genotypes of hot pepper tested, responded to this protocol. The best genotypes produced four to seven plants per original flower bud. This protocol can be used as a potential tool for producing doubled haploid plants for hot pepper breeding.

Capsicum↗

PubMed2004

Veterinary antimicrobial-usage statistics based on standardized measures of dosage.

In human medicine, the defined daily dose is used as a technical measure of drug usage, which is independent of the variations in the potency of the active compound and the formulation of the pharmaceutical product--therefore providing a measure of the relative importance of different drugs. A national system of animal defined daily doses (ADD) for each age-group and species has been defined in VetStat (the Danish national system monitoring veterinary therapeutic drug use). The usage is further standardized according to the number of animals in the target population, acquired from production data on the national level or on herd size by species and age in the Danish central husbandry register (CHR). Statistics based on standardized measures of VetStat data can be used for comparison of drug usage between different herds, veterinary practices, or geographic regions (allowing subdivision by animal species and animal production class, route of administration, disease categories, season and geographic location). Individual statistics are available as interactive reports to the control authorities, farmers and veterinary practitioners by a secure access to the database. The ADD also is used in pharmaco-epidemiogical research and to assist in the interpretation of resistance-surveillance data.

Animals↗

PubMed2004

Meiotic behaviour of individual chromosomes in allotriploid Alstroemeria hybrids.

Chromosome association and chiasma formation were studied in pollen mother cells at metaphase I of four allotriplod BC1 plants (2n=3x=24) obtained from the backcross of the hybrid Alstroemeria aurea x A. inodora with its parent A. inodora. We distinguished the chromosomes of both parental species by genomic in situ hybridization (GISH), whereas the individual chromosomes were identified on the basis of their multicolour FISH banding patterns obtained after a second hybridization with two species-specific satellite repeats as probes. All the four BC1 plants possessed two genomes of A. inodora and one of A. aurea. Variable numbers of recombinant chromosomes, resulting from meiotic recombination in the interspecific hybrid, were present in these plants. The homologous A. inodora chromosomes generally formed bivalents, leaving the homoeologous A. aurea chromosomes unassociated. High frequencies of trivalents were observed for the chromosome sets that contained recombinant chromosomes, even when the recombinant segments were small. Chromosome associations in the trivalents were restricted to homologous segments. The implications of the absence of homoeologous chromosome pairing on gamete constitution and prospects for introgression in Alstroemeria are discussed.

Alstroemeria↗

PubMed2003

VETSTAT-the Danish system for surveillance of the veterinary use of drugs for production animals.

The Danish Ministry of Food, Agriculture and Fisheries funds a monitoring system based on drug usage information collected at the herd level: VETSTAT. VETSTAT is constructed as a relational database and data originates from three sources: pharmacies, veterinarians and feed mills. All administration of drugs for use in animal production is reported on a monthly basis. Pharmacies provided 95% of the total weight antimicrobial compounds used in Denmark in 2001. More than 80% of the antimicrobial compounds reported by pharmacies were sold on prescription to end-users (owners) and included information on animal species, age-group and diagnostic grouping; >90% of the total amount of antimicrobials sold on prescription was used for pigs. In 2001, sales of 96,500 kg of antimicrobials were reported.

Animal Feed↗

PubMed2002

Evaluation of BC2 progenies derived from 3x-2x and 3x-4x crosses of Lilium hybrids: a GISH analysis.

An allotriploid (ALA, 2n=3 x=36) BC(1) plant was obtained by backcrossing a diploid F(1) interspecific hybrid (LA, 2n=2 x=24), derived from a Lilium longiflorum (L genome) and an Asiatic hybrid (A genome), to the latter parent. This allotriploid was backcrossed to a diploid Asiatic hybrid (2n=2 x=24) and to an allotetraploid (LLAA, 2n=4 x=48) LA hybrid. A total of 25 plants of these crosses were examined for ploidy level, and 12 individuals were analyzed for their genome constitution through genomic in situ hybridization (GISH). In most cases the progenies from the triploid-diploid (3 x-2 x) crosses consisted of aneuploids. Further more, there was evidence for the formation of near-haploid (x=12+2) to triploid (3 x=36) gametes in the allotriploid BC(1) plant. The progenies of triploid-tetraploid (3 x-4 x) cross also consisted of mostly aneuploids but in this case the triploid female parent had contributed predominantly near-triploid (2n) gametes for the origin of BC(2) progenies. The different ploidy levels observed between 3 x-2 x and 3 x-4 x crosses are possibly caused by preferential fertilization or survival resulting in a different ratio of chromosome numbers between the embryo and endosperm. Though Lilium has a tetrasporic, eight-nucleate type of embryo sac formation (Fritillaria type), the observed difference between the progeny types in 3 x-2 x and 3 x-4 x crosses is comparable to that of observed in monosporic eight nucleate types (Polygonum type) that predominate in most genera of Angiosperms. An important feature of the genome constitution of the progenies was that the homoeologous recombinant chromosomes were transmitted intact from BC(1) to BC(2) progenies in variable numbers. In addition, there was evidence for the occurrence of new homoeologous recombinations in the triploid BC(1). Of the two euploid BC(2) plants one had originated through the parthenogenetic development of a 2n egg and the other had originated through indeterminate meiotic restitution (IMR).

Chimera↗

PubMed2002

Can the QTL for late blight resistance on potato chromosome 5 be attributed to foliage maturity type?

We investigated the association between late blight resistance and foliage maturity type in potato by means of molecular markers. Two QTLs were detected for foliage resistance against Phytophthora infestans (on chromosomes 3 and 5) and one for foliage maturity type (on chromosome 5). The QTL for resistance to late blight and the QTL for foliage maturity type on chromosome 5 appeared to be mapped on indistinguishable positions. We were interested whether this genetic linkage was due to closely linked but different genes, or due to one (or more) gene(s) with pleiotropic effects. We therefore developed an approach to detect QTLs, in which resistance to late blight was adjusted for foliage maturity type. This analysis revealed the same two QTLs for resistance against P. infestans, but the effect of the locus on chromosome 5 was reduced to only half the original effect. This is a strong indication that the two indistinguishable QTLs for foliage maturity type and for late blight resistance on chromosome 5 may actually be one gene with a pleiotropic effect on both traits. However, there was still a significant effect on resistance against P. infestans on the locus on chromosome 5 after adjusting for foliage maturity type. Therefore we cannot rule out the presence of two closely linked QTLs on chromosome 5: one with a pleiotropic effect on both late blight resistance and foliage maturity type, and another with merely an effect on resistance. In addition, the two QTLs for resistance to late blight showed an important epistatic interaction, suggesting that QTLs for resistance affect each other's expression.

Alleles↗

PubMed2001

[Air in the portal vein and necrosis of the ventricle].

BACKGROUND: Air in the portal vein is a serious sign, usually caused by enteric necrosis. METHODS: The case report presents a 69-year-old male who died shortly after arrival in our department. RESULTS: Abdominal CT scan showed hepatic portal venous gas, and thrombi in the superior mesenteric artery, the coeliac trunk and in the left iliac artery. Autopsy revealed a necrotic stomach but viable small bowel. INTERPRETATION: Differential diagnoses are discussed, and we conclude that the patient most probably died from ischaemic necrosis. In severely ill patients, hepatic portal venous gas is an indication for urgent laparotomy.

Aged↗

PubMed2001

Multiple allelism as a control mechanism in metabolic pathways: GBSSI allelic composition affects the activity of granule-bound starch synthase I and starch composition in potato.

Multiple allelism in heterozygous autopolyploid species like potato not only occurs for genes that affect morphological characteristics but also for genes involved in metabolic pathways. Based on a combination of Southern and PCR analyses, at least eight alleles encoding granule-bound starch synthase I (GBSSI), which is responsible for amylose biosynthesis, have been identified in potato. These alleles were grouped into four classes, distinguishable by Southern analysis, and subdivided based on PCR. Despite the heterozygous and polyploid character of potato it was possible to assign variation in GBSSI activity to the allelic composition at the GBSSI loci within a large population of Solanum tuberosum cultivars and Solanum breeding lines. Moreover, the availability of an amf allele made it possible to reduce heterogeneity and enabled us to demonstrate an effect of GBSSI allelic composition on amylose content. The major difference between the alleles identified was the absence or presence of a 140-bp fragment at a site 0.5 kb upstream of the ATG start codon of the gene for GBSSI. The absence of this 140-bp fragment had a major effect on GBSSI activity and amylose content, while the presence of small deletions and simple sequence repeats had no obvious effect.

Algorithms↗

PubMed2001

Cranial nerve clock. Part 1. A declarative memory paradigm.

RATIONALE AND OBJECTIVES: The authors performed this study to compare a declarative memory paradigm developed to help teach medical students about the cranial nerves with a traditional text-based approach. MATERIALS AND METHODS: The authors designed a clock-based paradigm to help medical students learn about the cranial nerves. To enhance memorization and related brain activation, the paradigm uses visual, spatial, and word associations in the context of an analog clock face. Twenty-one undergraduate students were randomly divided into two groups. Group T viewed traditional text slides, and group C viewed text slides followed by the corresponding cranial clock slides. Subjects were tested before and after these sessions. RESULTS: Group C performed significantly better than group T in learning the names of the cranial nerves and their correct order (P < .011). Recall of name, number, and function was better for 11 of 12 cranial nerves, with statistical significance reached for nerves III (P = .005), V (P = .04), and X (P = .03). CONCLUSION: Alternative teaching strategies may help improve declarative memory.

Cranial Nerves↗

PubMed2001

Molecular characterization of transgenic shallots (Allium cepa L.) by adaptor ligation PCR (AL-PCR) and sequencing of genomic DNA flanking T-DNA borders.

Genomic DNA blot hybridization is traditionally used to demonstrate that, via genetic transformation, foreign genes are integrated into host genomes. However, in large genome species, such as Allium cepa L., the use of genomic DNA blot hybridization is pushed towards its limits, because a considerable quantity of DNA is needed to obtain enough genome copies for a clear hybridization pattern. Furthermore, genomic DNA blot hybridization is a time-consuming method. Adaptor ligation PCR (AL-PCR) of genomic DNA flanking T-DNA borders does not have these drawbacks and seems to be an adequate alternative to genomic DNA blot hybridization. Using AL-PCR we proved that T-DNA was integrated into the A. cepa genome of three transgenic lines transformed with Agrobacterium tumefaciens EHA 105 (pCAMBIA 1301). The AL-PCR patterns obtained were specific and reproducible for a given transgenic line. The results showed that T-DNA integration took place and gave insight in the number of T-DNA copies present. Comparison of AL-PCR and previously obtained genomic DNA blot hybridization results pointed towards complex T-DNA integration patterns in some of the transgenic plants. After cloning and sequencing the AL-PCR products, the junctions between plant genomic DNA and the T-DNA insert could be analysed in great detail. For example it was shown that upon T-DNA integration a 66 bp genomic sequence was deleted, and no filler DNA was inserted. Primers located within the left and right flanking genomic DNA in transgenic shallot plants were used to recover the target site of T-DNA integration.

Base Sequence↗

PubMed2001

Genomic in situ hybridization analysis of a trigenomic hybrid involving Solanum and Lycopersicon species.

A 4x potato (+) tomato fusion hybrid (2n = 4x = 48) was successfully backcrossed with a diploid Lycopersicon pennellii (2n = 2x = 24). Genomic in situ hybridization (GISH) on somatic and meiotic chromosomes confirmed that the progenies were triploids (2n = 3x = 36) and possessed three different genomes: potato, tomato, and L. pennellii. Therefore, they have been called trigenomic hybrids. Total genomic probes of both Lycopersicon species were found to hybridize mutually, whereas the potato genome was clearly differentiated. During metaphase I, bivalents were formed predominantly between tomato and L. pennellii chromosomes and the univalents of potato chromosomes were most common. Trivalents in all cases included homoeologous chromosomes of potato, tomato, and L. pennellii. However, the triploids were totally sterile as determined from extensive crossing. On chromosome doubling of triploids by shoot regeneration from callus, hexaploids (2n = 6x = 72) were obtained. Despite exhibiting clear allohexaploid behaviour by forming 36 bivalents at meiosis, these were also completely sterile like their triploid counterparts. In spite of this drawback, the prospects of chromosome pairing between potato L. pennellii and Solanum genomes does open the possibilities for bringing the two genera close.

Crosses, Genetic↗

PubMed2001

Karyotype analysis of Lilium longiflorum and Lilium rubellum by chromosome banding and fluorescence in situ hybridisation.

Detailed karyotypes of Lilium longiflorum and L. rubellum were constructed on the basis of chromosome arm lengths, C-banding, AgNO3 staining, and PI-DAPI banding, together with fluorescence in situ hybridisation (FISH) with the 5S and 45S rDNA sequences as probes. The C-banding patterns that were obtained with the standard BSG technique revealed only few minor bands on heterologous positions of the L. longiflorum and L. rubellum chromosomes. FISH of the 5S and 45S rDNA probes on L. longiflorum metaphase complements showed overlapping signals at proximal positions of the short arms of chromosomes 4 and 7, a single 5S rDNA signal on the secondary constriction of chromosome 3, and one 45S rDNA signal adjacent to the 5S rDNA signal on the subdistal part of the long arm of chromosome 3. In L. rubellum, we observed co-localisation of the 5S and 45S rDNA sequences on the short arm of chromosomes 2 and 4 and on the long arms of chromosomes 2 and 3, and two adjacent bands on chromosome 12. Silver staining (Ag-NOR) of the nucleoli and NORs in L. longiflorum and L. rubellum yielded a highly variable number of signals in interphase nuclei and only a few faint silver deposits on the NORs of mitotic metaphase chromosomes. In preparations stained with PI and DAPI, we observed both red- and blue-fluorescing bands at different positions on the L. longiflorum and L. rubellum chromosomes. The red-fluorescing or so-called reverse PI-DAPI bands always coincided with rDNA sites, whereas the blue-fluorescing DAPI bands corresponded to C-bands. Based on these techniques, we could identify most of chromosomes of the L. longiflorum and L. rubellum karyotypes.

Chromosome Banding↗

PubMed2000

Genetic diversity of Chilean and Brazilian alstroemeria species assessed by AFLP analysis.

One to three accessions of 22 Alstroemeria species, an interspecific hybrid (A. aurea x A. inodora), and single accessions of Bomarea salsilla and Leontochir ovallei were evaluated using the AFLP-marker technique to estimate the genetic diversity within the genus Alstroemeria. Three primer combinations generated 716 markers and discriminated all Alstroemeria species. The dendrogram inferred from the AFLP fingerprints supported the conjecture of the generic separation of the Chilean and Brazilian Alstroemeria species. The principal co-ordinate plot showed the separate allocation of the A. ligtu group and the allocation of A. aurea, which has a wide range of geographical distribution and genetic variation, in the middle of other Alstroemeria species. The genetic distances, based on AFLP markers, determined the genomic contribution of the parents to the interspecific hybrid.

Brazil↗

PubMed2000

Home mechanical ventilation in Sweden, with reference to Danish experiences. Swedish Society of Chest Medicine.

The Swedish Society of Chest Medicine has started a national register of patients on home mechanical ventilation, to establish reliable national prevalence data and to accurately document patient and treatment characteristics to enable a scientific evaluation of this treatment. In this first collection of retrospective register data, covering patients on home mechanical ventilation at the register start on 1 January 1996, we found 541 patients, corresponding to 6.1/100000 inhabitants, using home mechanical ventilation. Non-invasive ventilation, night-time ventilation and volume controlled ventilation dominated. We found four diagnosis categories of approximately equal size, namely post-polio, chest wall deformities, neuromuscular diseases and 'other diseases'. The age distribution was bimodal, with one small peak in the 20-29 year group and a large peak in the 60-69 year group. A survey of Danish patients on home mechanical ventilation showed that they were considerably younger and that almost half of them suffered from neuromuscular diseases. Further work will be done to follow the situation in Sweden and in Denmark to elucidate the obvious differences in the selection of patients for home mechanical ventilation.

Adult↗

PubMed2000

The use of somatic embryogenesis for plant propagation in cassava.

In cassava, somatic embryogenesis starts with the culture of leaf explants on solid Murashige and Skoog-based medium supplemented with auxins. Mature somatic embryos are formed within 6 wk. The cotyledons of the primary somatic embryos are used as explants for a new cycle of somatic embryogenesis. The cotyledons undergo secondary somatic embryogenesis on both liquid and solid Murashige and Skoog-based medium supplemented with auxins. Depending on the auxin, new somatic embryos are formed after 14-30 d after which they can be used for a new cycle of somatic embryogenesis. In liquid medium, more than 20 secondary somatic embryos are formed per initial cultured embryo. In both primary and secondary somatic embryogenesis, the somatic embryos originate directly from the explants. Transfer of clumps of somatic embryos to a Gresshoff and Doy-based medium supplemented with auxins results in indirect somatic embryogenesis. The direct form of somatic embryogenesis has a high potential for use in plant propagation, whereas the indirect has a high potential for use in genetic modification of cassava. Mature somatic embryos germinate into plants after desiccation and culture on a Murashige and Skoog-based medium supplemented with benzylaminopurine (BA). Depending on the used BA concentration, plants can either be transferred either directly to the greenhouse or after using standard multiplication protocols.

Culture Media↗

PubMed1999

[Decompression sickness after diving and following flying].

A case of delayed symptoms of decompression sickness (DCS) after diving and flying is reported. The diver presented with classical signs of type 2 DCS, probably caused by air travel 16 hours after SCUBA diving. Treatment with hyperbaric oxygen (HBO) in a decompression chamber was successful. Guidelines to prevent DCS for recreational divers who plan to fly after diving are presented.

Adult↗

PubMed1999

[Anesthesiologic aspects in patients with HIV infections].

A review of anaesthesia for patients with HIV-infection is given. The use of new antiretroviral drug combinations to treat HIV-infection may result in longer survival, and therefore more cases of HIV-positive patients who undergo surgery and require anaesthetic services. Clinical manifestations of the HIV infection in humans can be seen in almost every organ. The anaesthetist must have an understanding of the many manifestations of the syndrome. Physical examination and preoperative preparation is essential. Considerations for the anaesthetist include: the effects of medications and possible drug interactions, organ dysfunction, altered metabolism and choice of anaesthetic technique for the HIV-positive patient. Anaesthetists and other health care professionals must know about the manifestations of HIV-infection in order to provide competent and compassionate care.

Anesthesia↗

PubMed1999

The extent and position of homoeologous recombination in a distant hybrid of Alstroemeria: a molecular cytogenetic assessment of first generation backcross progenies.

To estimate the extent and position of homoeologous recombination during meiosis in an interspecific hybrid between two distantly related Alstroemeria species, the chromosome constitution of six first generation backcross (BC1) plants was analysed using sequential fluorescent in situ hybridization (FISH) and genomic in situ hybridization (GISH) analysis. Four different probes were used for the FISH analysis: two species-specific and two rDNA probes. The six BC1 plants were obtained from crosses between the hybrid A. aurea x A. inodora with its parent A. inodora. GISH clearly identified all chromosomes of both parental genomes as well as recombinant chromosomes. The sequential GISH and FISH analysis enabled the accurate identification of all individual chromosomes in the BC1 plants, resulting in the construction of detailed karyotypes of the plants. The identification of the recombinant chromosomes provided evidence which chromosomes of the two species are homoeologous. Two of the BC1 plants were aneuploid (2n=2x+1=17) and four triploid (2n=3x=24), indicating that both n and 2n gametes were functional in the F1 hybrid. Using GISH, it was possible to estimate homeologous recombination in two different types of gametes in the F1 hyrid. The positions of the crossover points ranged from highly proximal to distal and the maximum number of crossover points per chromosome arm was three. Compared with the aneuploid plants, the triploid plants (which received 2n gametes) clearly possessed fewer crossovers per chromosome, indicating reduced chromosome pairing/recombination prior to the formation of the 2n gametes. Besides homeologous recombination, evidence was found for the presence of structural rearrangements (inversion and translocation) between the chromosomes of the parental species. The presence of the ancient translocation was confirmed through FISH analysis of mitotic and meiotic chromosomes.

Aneuploidy↗