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Biomedical subjects

L Andersson

Publications and source records attributed to L Andersson.

At least 91 records · Page 5Linked to original sources
PubMed2000

Palliation of bone metastases: a survey of patterns of practice among Canadian radiation oncologists.

BACKGROUND: Palliative radiotherapy constitutes nearly 50% of the workload in radiotherapy. Surveys on the patterns of practice in radiotherapy have been published from North America and Europe. Our objective was to determine the current pattern of practice of radiation oncologists in Canada for the palliation of bone metastases. METHOD: A survey was sent to 300 practicing radiation oncologists in Canada. Five case scenarios were presented. The first three were patients with a single symptomatic site: breast cancer patient with pelvic metastasis, lung cancer male with metastasis to L3 and L1, respectively. The last two were breast and prostate cancer patients with multiple symptomatic bone metastases. RESULTS: A total of 172 questionnaires were returned (57%) for a total of 860 responses. For the three cases with a single painful bone metastasis, over 98% would prescribe radiotherapy. The doses ranged from a single 8 to 30 Gy in ten fractions. Of the 172 respondents, 117 (68%) would use the same dose fractionation for all three cases, suggesting that they had a standard dose fractionation for palliative radiotherapy. The most common dose fractionation was 20 Gy in five fractions used by 84/117 (72%), and 8 Gy in one fraction by 19/117 (16%). In all five case scenarios, 81% would use a short course of radiotherapy (single 8 Gy, 17%; 20 Gy in five fractions, 64%), while 10% would prescribe 30 Gy in ten fractions. For the two cases with diffuse symptomatic bone metastases, half body irradiation (HBI) and radionuclides were recommended more frequently in prostate cancer than in breast cancer (46/172 vs. 4/172, P<0. 0001; and 93/172 vs. 10/172, P<0.0001, respectively). Strontium was the most commonly recommended radionuclide (98/103=95%). Since systemic radionuclides are not readily available in our health care system, 41/98 (42%) of radiation oncologists who would recommend strontium were not familiar with the dose. Bisphosphonates were recommended more frequently in breast cancer than in prostate cancer 13/172 (8%) vs. 1/172 (0.6%), P=0.001. CONCLUSION: Local field external radiotherapy remains the mainstay of therapy, and the most common fractionation for bone metastases in Canada is 20 Gy in five fractions compared with 30 Gy in ten fractions in the US. Despite randomized trials showing similar results for single compared with fractionated radiotherapy, the majority of us still advocate five fractions. The frequency of employing a single fractionation has not changed since the last national survey in 1992. Nearly 70% use a standard dose fractionation to palliate localized painful metastasis by radiotherapy, independent of the site of involvement or tumor type. The pattern of practice of palliative radiotherapy for bone metastases in Canada is different to that reported previously from the US. The reasons why the results of randomized studies on bone metastases have no impact on the patterns of practice are worth exploring.

Bone Neoplasms↗
PubMed2000

Utility of an intervention scoring system in documenting effects of changes in burn treatment.

The consequences of the introduction of a program of consistent use of topical antimicrobials and early aggressive excision of deep burn wounds by utilizing a comprehensive, computerized patient registry/therapeutic intervention scoring system, were investigated. Prospectively, the clinical course, mortality, outcome and hospital costs were compared for the year preceding (89 patients) and the 4 years following (226 patients) the introduction of the new treatment program. It was found that mortality decreased from 10.1 to 4.6% after change in therapy (P<0.001), despite an increase in mean burn extent. The length of hospital stay per % burn surface area declined from 1.2 to 1.0 days (P<0.001). The number and complexity of therapeutic interventions and the associated costs, also declined. Patients in the new treatment program had a better level of physical and psychosocial function at follow up. In conclusion, the introduction of a program of consistent use of topical antimicrobials and early, aggressive surgical excision was associated with an improved outcome at lesser cost. The combined registry-intervention scoring system permits ready analysis of results using data entered on a daily, near-real time basis.

Adult↗
PubMed2000

Mapping quantitative trait loci for principal components of bone measurements and osteochondrosis scores in a wild boar x large white intercross.

Data on osteochondrosis and femur dimensions from 195 F2 pigs from a wild boar x Large White intercross were analysed with the aim of detecting quantitative trait loci (QTLs) for normal and disturbed bone formation. The information from numerous recorded traits was summarized by principal component analysis and analysed by least-squares interval mapping. An increase in the proportion of wild boar alleles across the genome increased length versus width of femur and reduced the prevalence of osteochondrosis. The presence of QTLs with an impact on femur dimensions was indicated on chromosomes 2, 4, 16 and 17 and on osteochondrosis on chromosomes 5, 13 and 15. A substantial effect of the chromosome 5 QTL calls for further studies within commercial populations to evaluate whether marker-assisted selection could be used to reduce the prevalence of osteochondrosis.

Alleles↗
PubMed2000

Expression of different phenotypes in cell lines from canine mammary spindle-cell tumours and osteosarcomas indicating a pluripotent mammary stem cell origin.

Mammary spindle-cell tumours and sarcomas seem to be restricted to dogs and humans. Two cell lines from spontaneous primary canine mammary spindle-cell tumours (CMT-U304 and CMT-U309) and two cell lines from spontaneous primary canine mammary osteosarcomas (CMT-U334 and CMT-U335) were established to study the mesenchymal phenotypes of mammary tumours in the female dog. The cells from the spindle-cell tumours expressed cytokeratin, vimentin and smooth muscle actin filaments. When these cells were inoculated subcutaneously into female and male nude mice they formed different types of mesenchymal tumours such as spindle-cell tumours, fibroma and rhabdomyoid tumours (n = 6/8). The cells from the osteosarcomas expressed vimentin filaments and also formed different types of mesenchymal tumours such as chondroid, rhabdomyoid, smooth muscle-like and spindle-cell tumours (n = 6/10). The cell lines CMT-U304, CMT-U309 and CMT-U335 had receptors for progesterone but none of the four cell lines had receptors for estrogen. All four cell lines and their corresponding primary tumours showed identical allelic patterns in microsatellite analysis. By in situ hybridization with genomic DNA we could verify that all formed tumours but one were of canine origin. Our results support the hypothesis that canine mammary tumours are derived from pluripotent stem cells.

Animals↗
PubMed2000

Direct and indirect time spent on care of dental trauma: a 2-year prospective study of children and adolescents.

The aim was to account for the total time spent by professional care-givers (direct time) and by patients and companions engaged as support and help (indirect time) to treat and otherwise attend to children and adolescents with dental trauma to primary and permanent teeth. The study was based on a random sample of 192 children and adolescents with dental traumas reported to an insurance company and prospectively followed up by telephone interviews over a period of 2 years after the trauma episode. On average, direct time represented 16% of total time for all visits for dental trauma to permanent teeth and 11% for trauma to primary teeth. The most extensive type of indirect time was transport time, which took up 30% of the total time spent on injuries to permanent teeth and 36% for injuries to primary teeth. Multiple regression analysis of the impact of dental and demographic injury variables on the time variables showed that complicated trauma was associated with extended time, direct as well as indirect, for permanent and primary teeth injuries. Our estimate of the average relative increase in total time spent by patients and companions in cases of complicated injury to permanent teeth was 117% (95% confidence interval [CI], 52-211) for patients and 112% (95% CI, 42-217) for companions. For transport time a strong predictor was access to a dental clinic near the place of residence. Lack of access could extend the average transport time by 180% (95% CI, 80-335) for patients and 163% (95% CI, 67-317) for their companions in cases of injuries to primary teeth.

Absenteeism↗
PubMed2000

Mapping quantitative trait loci for stress induced alterations in porcine leukocyte numbers and functions.

To identify quantitative trait loci (QTLs) with effects on 'stress' induced alterations of porcine immune functions, a number of immune capacity traits were analysed in the F2 generation of a Wild Boar--Yorkshire intercross. All traits were measured prior, and one day after, exposure to experimental 'stress' (mixing and transport). The 'stress' protocol induced a decrease in numbers of circulating neutrophils and in spontaneous proliferation in vitro, whereas phagocytic capacity, mitogen induced proliferation and spontaneous IL-2 activity increased. The IFN-alpha production tended to decrease, although the individual variation was pronounced. More than 200 genetic markers have been scored in the entire pedigree and were used to trace the inheritance of individual chromosome segments. Wild Boar alleles were on average associated with higher mitogen induced IL-2 activity and a slightly lower decrease in IFN-alpha production after mixing and transport. Four QTLs with significant effects were identified; one influencing 'stress' induced alteration in numbers of neutrophils (chromosome 8), one influencing spontaneous proliferation after 'stress' (chromosome 2), one influencing mitogen induced IL-2 activity after 'stress' (chromosome 6) and one influencing 'stress' induced alterations in mitogen induced IL-2 activity (chromosome 12). In addition, several suggestive QTLs were indicated.

Animals↗
PubMed2000

Detection of the causal mutation for canine leukocyte adhesion deficiency (CLAD) using pyrosequencing.

A missense mutation in the ITGB2 gene causes canine leukocyte adhesion deficiency (CLAD) in Irish setters. We constructed a diagnostic test to identify heterozygous CLAD carriers based on a newly developed technology termed pyrosequencing. Although primarily designed for high-speed generation of DNA sequence in a gel-free system, the technology can be applied to rapid single-nucleotide polymorphism analysis in a clinical setting. The testing of 339 dogs originating from a total of 10 countries was conducted and CLAD carriers were identified within every country where more than one sample was analysed. This indicates that the CLAD mutation is widespread and that there is a strong need for a robust diagnostic test.

Animals↗
PubMed2000

Tumor necrosis factor-alpha and transforming growth factor-beta1 in chronic periapical lesions.

OBJECTIVE: Proinflammatory cytokines are involved in the pathogenesis of periapical lesions. The purpose of this study was to evaluate the presence of the cytokines tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta(1) (TGF-beta(1)) in periapical pathosis and to determine their relationship to the size of the lesions. STUDY DESIGN: One tooth from each of 25 patients was root-end resected, and the periapical lesion was collected. The amounts of TNF-alpha and TGF-beta(1) were assessed by enzyme-linked immunosorbent assay. RESULTS: TGF-beta(1) was detected in 21 of 25 lesions. In samples with scar tissue, no TGF-beta(1) activity was detected. A statistically significant correlation was found between TGF-beta(1) per milligram of tissue and the diameter of the lesions. TNF-alpha was detected in only 2 samples. CONCLUSIONS: TGF-beta(1) was present in periapical granulomas and cysts but not in lesions with scar tissue. The correlation between the amount of TGF-beta(1) per milligram of tissue and the size of the lesion was significant.

Adult↗
PubMed2000

Carcinoma in situ in the testis.

Carcinoma in situ (CIS) of the testis is a common precursor of germ-cell tumours in adults and adolescents, with the exception of spermatocytic seminoma. This article reviews existing knowledge on the pathobiology, genetic aspects and epidemiology of CIS, discusses current hypotheses concerning pathogenesis and invasive progression of germ-cell neoplasms and provides guidelines for diagnosis and clinical management of CIS.

Adolescent↗
PubMed2000

The origin of the domestic pig: independent domestication and subsequent introgression.

The domestic pig originates from the Eurasian wild boar (Sus scrofa). We have sequenced mitochondrial DNA and nuclear genes from wild and domestic pigs from Asia and Europe. Clear evidence was obtained for domestication to have occurred independently from wild boar subspecies in Europe and Asia. The time since divergence of the ancestral forms was estimated at approximately 500,000 years, well before domestication approximately 9,000 years ago. Historical records indicate that Asian pigs were introduced into Europe during the 18th and early 19th centuries. We found molecular evidence for this introgression and the data indicated a hybrid origin of some major "European" pig breeds. The study is an advance in pig genetics and has important implications for the maintenance and utilization of genetic diversity in this livestock species.

Animals↗
PubMed2000

Combined analyses of data from quantitative trait loci mapping studies. Chromosome 4 effects on porcine growth and fatness.

For many species several similar QTL mapping populations have been produced and analyzed independently. Joint analysis of such data could be used to increase power to detect QTL and evaluate population differences. In this study, data were collated on almost 3000 pigs from seven different F(2) crosses between Western commercial breeds and either the European wild boar or the Chinese Meishan breed. Genotypes were available for 31 markers on chromosome 4 (on average 8.3 markers per population). Data from three traits common to all populations (birth weight, mean backfat depth at slaughter or end of test, and growth rate from birth to slaughter or end of test) were analyzed for individual populations and jointly. A QTL influencing birth weight was detected in one individual population and in the combined data, with no significant interaction of the QTL effect with population. A QTL affecting backfat that had a significantly greater effect in wild boar than in Meishan crosses was detected. Some evidence for a QTL affecting growth rate was detected in all populations, with no significant differences between populations. This study is the largest F(2) QTL analysis achieved in a livestock species and demonstrates the potential of joint analysis.

Adipose Tissue↗
PubMed2000

The use of a genetic algorithm for simultaneous mapping of multiple interacting quantitative trait loci.

Here we describe a general method for improving computational efficiency in simultaneous mapping of multiple interacting quantitative trait loci (QTL). The method uses a genetic algorithm to search for QTL in the genome instead of an exhaustive enumerative ("step-by-step") search. It can be used together with any method of QTL mapping based on a genomic search, since it only provides a more efficient way to search the genome for QTL. The computational demand decreases by a factor of approximately 130 when using genetic algorithm-based mapping instead of an exhaustive enumerative search for two QTL in a genome size of 2000 cM using a resolution of 1 cM. The advantage of using a genetic algorithm increases further for larger genomes, higher resolutions, and searches for more QTL. We show that a genetic algorithm-based search has efficiency higher than or equal to a search method conditioned on previously identified QTL for all epistatic models tested and that this efficiency is comparable to that of an exhaustive search for multiple QTL. The genetic algorithm is thus a powerful and computationally tractable alternative to the exhaustive enumerative search for simultaneous mapping of multiple interacting QTL. The use of genetic algorithms for simultaneous mapping of more than two QTL and for determining empirical significance thresholds using permutation tests is also discussed.

Algorithms↗
PubMed2000

Evolution of the neuropeptide Y receptor family: gene and chromosome duplications deduced from the cloning and mapping of the five receptor subtype genes in pig.

Neuropeptide Y (NPY) receptors mediate a variety of physiological responses including feeding and vasoconstriction. To investigate the evolutionary events that have generated this receptor family, we have sequenced and determined the chromosomal localizations of all five presently known mammalian NPY receptor subtype genes in the domestic pig, Sus scrofa (SSC). The orthologs of the Y(1) and Y(2) subtypes display high amino acid sequence identities between pig, human, and mouse (92%-94%), whereas the Y(4), Y(5), and y(6) subtypes display lower identities (76%-87%). The lower identity of Y(5) is due to high sequence divergence in the large third intracellular loop. The NPY1R, NPY2R, and NPY5R receptor genes were localized to SSC8, the NPY4R to SSC14, and NPY6R to SSC2. Our comparisons strongly suggest that the tight cluster of NPY1R, NPY2R, and NPY5R on human chromosome 4 (HSA4) represents the ancestral configuration, whereas the porcine cluster has been split by two inversions on SSC8. These 3 genes, along with adjacent genes from 14 other gene families, form a cluster on HSA4 with extensive similarities to a cluster on HSA5, where NPY6R and >13 other paralogs reside, as well as another large cluster on HSA10 that includes NPY4R. Thus, these gene families have expanded through large-scale duplications. The sequence comparisons show that the NPY receptor triplet NPY1R-NPY2R-NPY5R existed before these large-scale duplications.

Animals↗
PubMed2000

Oral health care--a low priority in nursing. In-depth interviews with nursing staff.

In this study we examined how nursing home staff experienced assisting patients with oral health care. The results of a previous questionnaire indicated that oral health care is a low priority in nursing. The 22 in-depth interviews administered in this study showed that the quality of the oral health care received by the patients depended on several factors. It was found that often there were no specific routines for assisting oral health care in the nursing homes and that other activities were given higher priority. Assisting oral health care was described as passing a barrier, where the main problem was to gain access to the oral cavity. It was concluded that nursing staff working with geriatric patients need to be better educated in oral health care and should be seen by themselves and others as part of a team, where oral health care is clearly defined and included among other daily nursing activities.

Aged↗
PubMed1999

Increased cerebrospinal fluid protein tau concentration in neuro-AIDS.

OBJECTIVES: Assessment of cerebrospinal fluid (CSF) levels of protein tau in human immunodeficiency virus type 1 (HIV-1) infection. MATERIAL AND METHODS: CSF tau levels were analyzed in 52 HIV-1-infected patients, 37 of whom had no neurological symptoms, eight had aquired immunodeficiency syndrome (AIDS) dementia complex (ADC), and seven had AIDS with other neurological complications. RESULTS: A significantly higher mean CSF tau concentration was found in patients with ADC (380 pg/ml) compared with patients with neuroasymptomatic HIV-1 infection (120 pg/ml, P<0.01) and HIV-negative controls (150 pg/ml, P<0.05). No difference in CSF tau levels was found between patients with ADC and patients with AIDS with other neurological complications. CONCLUSION: CSF tau might be used as a biochemical marker for axonal degeneration and might be of use to identify HIV-1-infected patients with ADC and other neurological complications, but it cannot discriminate between ADC and other neurological complications in HIV-1-infection.

AIDS Dementia Complex↗
PubMed1999

A missense mutation in the beta-2 integrin gene (ITGB2) causes canine leukocyte adhesion deficiency.

Canine leukocyte adhesion deficiency (CLAD) is a fatal immunodeficiency disease found in Irish setters. The clinical manifestations of CLAD are very similar to LAD in humans and BLAD in cattle, which are both caused by mutations in ITGB2 encoding the leukocyte integrin beta-2 subunit (CD18). Sequence analysis of the ITGB2 coding sequence from a CLAD dog and a healthy control revealed a single missense mutation, Cys36Ser. This cysteine residue is conserved among all beta integrins, and the mutation most likely disrupts a disulfide bond. The mutation showed a complete association with CLAD in Irish setters and was not found in a sample of dogs from other breeds. The causative nature of this mutation was confirmed by transduction experiments using retroviral vectors and human LAD EBV B-cells. The normal canine CD18 formed heterodimers with the human CD11 subunit, whereas gene transfer of the mutant CD18 resulted in very low levels of CD11/CD18 expression. The identification of the causative mutation for CLAD now makes it possible to identify carrier animals with a simple diagnostic DNA test, and it forms the basis for using CLAD as a large animal model for the development and evaluation of clinical treatments for human LAD.

Amino Acid Sequence↗
PubMed1999

Cytotoxicity testing of a new caprolactone-coated self-expanding bioabsorbable self-reinforced poly-L-lactic acid urethral stent.

Forty to 75% of strictures recur within 2 years of urethrotomy and the essential problem remains how to prevent the edges of the cut stricture from adhering to each other and the scar from shrinking. To solve this problem different kinds of urethral stents have been used. Recently a new bioabsorbable self-expanding urethral stent was developed by our group. The core consists of self-reinforced (SR) poly-L-lactic acid (PLLA) and the coating is made of an amorphous copolymer of caprolactone and D,L-lactic acid [P(epsilon-CL/ D,L-LA)]. The aim of our present study was to test the cytotoxicity of the new material used to coat the SR-PLLA urethral stent utilizing the thymidine incorporation method (DNA synthesis inhibition test). The new materials showed no acute toxicity and can be regarded as biocompatible in medical devices.

Animals↗