| 31. |
- Toma-Dasu, Iuliana, et al.
(författare)
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Theoretical simulation of oxygen tension measurement in the tissue using a microelectrode: II. Simulated measurements in tissues
- 2002
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Ingår i: Radiotherapy and Oncology. - 0167-8140 .- 1879-0887. ; 64:1, s. 109-118
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The objectives of this study were to make a computer simulation of tissues with different vascular structures and to simulate measurements of oxygen tension using an Eppendorf-like electrode in these tissues and to compare the response to radiation of the tissues with the real oxygen distributions (called input distribution) with the response to radiation of the tissues in which the oxygen distribution is given by the results of the simulated measurements (called output distribution).MATERIALS AND METHODS: The structure of various tissues and the measurements of oxygen tension using a microelectrode were simulated using a computer program. The mathematical model used combines the description of a gradient of tissue oxygenation and the electrode absorption process.RESULTS: We have compared the oxygen distributions resulting from diffusion (input) with those obtained from a simulation of measurements (output) for various tissues in the same points. Because the electrode measurement is an averaging process, the calculated oxygen distributions are different from the expected ones and the extreme high and low values are not detected. We have then calculated the survival curves describing the response to radiation if there is a small fraction of truly hypoxic cells (expected values) or a large fraction of cells at intermediate values (observed results) in order to determine the differences between them.CONCLUSIONS: The results of our study show that oxygen electrode measurements do not give the true distribution of pO(2) values in the tissue. However, our results do not contradict the numerous empirical correlations between the Eppendorf measurements of tumour oxygenation and the outcome of treatments. Measurement results will be misleading for modelling purposes since they do not reflect the actual distributions of oxygen tensions in the measured tissue. Decisions based on such modelling could be very dangerous, especially with respect to the clinical response of tumours to new treatments.
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| 32. |
- Wahlin, A, et al.
(författare)
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Reference values for serum levels of vitamin B12 and folic acid in a population-based sample of adults between 35 and 80 years of age
- 2002
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Ingår i: Public health nutrition. - : Cambridge University Press (CUP). - 1368-9800 .- 1475-2727. ; 5:3, s. 505-511
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Tidskriftsartikel (refereegranskat)abstract
- Objectives:To examine folic acid and vitamin B12status in a group of 1000 persons sampled from the community of Umeå, Sweden, and aged 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80 years. Reference data for folate and age-stratified reference data for vitamin B12are presented, together with an examination of potential confounders.Measurements:All subjects participated in extensive health examinations and interviews, and laboratory blood testing was performed.Results:A series of exclusion criteria were applied, and data from 961 subjects were analysed. Vitamin B12levels were found to decrease with increasing age, whereas folate levels remained constant across the age span studied. None of the vitamins was found to vary with sex, education, smoking or alcohol consumption, body mass index, prescription-free vitamin supplements, level of haemoglobin, or mean cell volume of erythrocytes. Further, none of these factors was associated with the age-related decrease of vitamin B12level.Conclusions:The offered reference ranges should be used only in order to rule out deficiency. For B12levels, the age of the subject should be considered such that, for elderly people in particular, values above the medians should be considered as indicative of normal vitamin status.
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| 33. |
- Jansson, Per-Anders, 1961, et al.
(författare)
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Endocrine abnormalities in healthy first-degree relatives of type 2 diabetes patients--potential role of steroid hormones and leptin in the development of insulin resistance.
- 2002
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Ingår i: European journal of clinical investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 32:3, s. 172-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: First-degree relatives of type 2 diabetes patients are at risk of developing diabetes and they display several metabolic and hormonal perturbations. The interplay between insulin resistance, steroid hormones and circulating leptin is, however, still not fully explored in this group. DESIGN: Thirty-three healthy first-degree relatives of type 2 diabetic patients (relatives; M/F 19/14) were compared to 33 healthy subjects without a family history of diabetes (controls) and the groups were matched for gender, age and body mass index (BMI). We performed euglycaemic hyperinsulinaemic clamps and blood was sampled for hormone analyses. RESULTS: Relatives exhibited decreased insulin sensitivity (index of metabolic clearance rate of glucose; MCRI) but when genders were analysed separately, this difference was significant only in males (11.3 +/- 1.3 vs. 15.0 +/- 1.5 units, means +/- SEM, P = 0.030). In male relatives morning cortisol and testosterone levels were lower, whereas leptin was higher than in male controls (P = 0.018, 0.008 and 0.063, respectively). In male relatives plasma testosterone levels were significantly associated with insulin sensitivity (r = 0.48, P = 0.040). Circulating leptin levels were inversely correlated with insulin sensitivity in all subject groups (r-values -0.49 to -0.66; P < 0.05, except in female control subjects P = 0.063). These associations were present also when age and BMI or waist:hip ratio were included in stepwise multiple regression analyses. CONCLUSION: Male subjects genetically predisposed for type 2 diabetes display several endocrine abnormalities including leptin, cortisol and testosterone levels. Dysregulation of these hormones may be important in the development of insulin resistance and type 2 diabetes.
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| 34. |
- Tajsharghi, Homa, 1968, et al.
(författare)
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Myosin heavy chain IIa gene mutation E706K is pathogenic and its expression increases with age.
- 2002
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Ingår i: Neurology. - : Lippincott Williams & Wilkins. - 0028-3878 .- 1526-632X. ; 58:5, s. 780-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The authors recently described a new autosomal dominant myopathy (OMIM 605637 inclusion body myopathy 3) associated with a missense mutation in the myosin heavy chain (MyHC) IIa gene (MyHC IIa, Human Gene Map [HGM] locus MYH2). Young patients showed minor changes in their muscle biopsies, although dystrophic alterations and rimmed vacuoles with 15- to 20-nm tubulofilaments identical to those in sporadic inclusion body myositis (s-IBM) were observed in some of the adult (especially older) patients. The current study was undertaken to investigate the relation between expression of the mutant MyHC IIa and pathologic changes in muscle. METHODS: The expression of MyHC IIa in nine muscle specimens from six individuals carrying the mutation was analyzed by immunohistochemistry, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and a new reverse transcriptase--PCR method to measure the relative abundance of the various MyHC transcripts. RESULTS: Young patients with muscle weakness and minor pathologic changes in muscle expressed MyHC IIa at undetectable levels. MyHC IIa was expressed at high levels in adults with a progressive clinical course and dystrophic muscle changes. In these cases, a large number of muscle fibers were hybrids with expression of more than one MyHC isoform. Both MyHC IIa alleles were equally expressed. The relative level of MyHC IIa transcripts exceeded that of the corresponding protein, indicating an increased turnover of mutated protein. MyHC IIa expression was a consistent finding in muscle fibers with rimmed vacuoles. CONCLUSIONS: The clear correlation between pathologic changes and expression of MyHC IIa indicates that defects in MyHC may lead not only to muscle weakness but also to muscle degeneration. The consistent expression of MyHC IIa in muscle fibers with rimmed vacuoles indicates that the breakdown of sarcomeric proteins is a key element in the pathogenesis of rimmed vacuoles of s-IBM type.
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| 35. |
- Forslund, Ola, et al.
(författare)
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Population-based type-specific prevalence of high-risk human papillomavirus infection in middle-aged Swedish Women.
- 2002
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Ingår i: Journal of Medical Virology. - : Wiley. - 1096-9071 .- 0146-6615. ; 66:4, s. 535-541
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Tidskriftsartikel (refereegranskat)abstract
- Human papillomavirus (HPV) DNA testing can be used to identify women at risk of the development of cervical cancer. The cost-effectiveness of HPV screening is dependent on the type-specific HPV prevalence in the general population. The present study describes the prevalence and spectrum of high-risk HPV types found in a large real-life population-based HPV screening trial undertaken entirely within the cervical screening program offered to middle-aged Swedish women. Cervical brush samples from 6,123 women aged 32-38 years were analyzed using a general HPV primer (GP5(+)/6(+)) polymerase chain reaction-enzyme immunoassay (PCR-EIA) combined with reverse dot-blot hybridization for confirmation and HPV typing by a single assay. In this study, 6.8% (95% CI 6.2-7.5) (417/6,123) were confirmed as high-risk HPV positive. Infections with 13 different high-risk HPV types were detected, of which HPV 16 was the most prevalent type (2.1%; 128/6,123), followed by HPV 31 (1.1%; 67/6,123). Any one of the HPV types 18, 33, 35, 39, 45, 51, 52, 56, 58, 59, or 66 was detected in 3.6% (223/6,123) of the women. Infection with two, three, and five types simultaneously was identified in 32, 5, and 1 women, respectively. The combination of PCR-EIA as a screening test and reverse dot-blot hybridization as a confirmatory test, was found to be readily applicable to a real-life population-based cervical screening. The type-specific HPV prevalence found support in previous modeling studies suggesting that HPV screening may be a favorable cervical screening strategy.
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| 36. |
- Oberg, M, et al.
(författare)
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Subchronic toxicity of Baltic herring oil and its fractions in the rat I: Fractionation and levels of organohalogen pollutants
- 2002
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Ingår i: Pharmacology and Toxicology. - : Wiley. - 1600-0773 .- 0901-9928. ; 91:5, s. 220-231
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Tidskriftsartikel (refereegranskat)abstract
- Baltic herring (Clupea harengus) oil was extracted and fractionated. To examine the contribution to toxicity and biological effects of different halogenated organic pollutants, the herring oil and the fractions were mixed into pelleted food and given to Sprague-Dawley female rats at three levels, corresponding to a human intake of 1.6, 8.2 and 34.4 kg fish per week. Herring oil, its fractions, as well as liver tissues from exposed rats, were analyzed for: eight chlorinated biphenyls, all 2,3,7,8-substituted chlorinated dibenzo-p-dioxins and dibenzofurans, hexachlorocyclohexanes, hexachlorobenzene, 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), DDT-metabolites, three brominated diphenylethers as well as extractable organically bound chlorine and halogenated fatty acids. A bioassay (EROD) was used for measuring the dioxin-like enzyme induction activity. Nordic Sea lodda (Mallotus villosus) oil was used as a nutritionally equivalent control, with much lower levels of halogenated organic pollutants. A full toxicological subchronic examination is reported in the following paper (Stern et al. 2002). In this study, we report that the fractionation procedure resulted in a substantial reduction of most of the pollutants in the triacylglycerol fraction, and a pronounced enrichment of most of the pollutants into the two other fractions. However, all contaminants were present at some levels in all of the fractions. The concentrations of organoltalogens found in this study were representative for Baltic herring during the mid-1990s. Rat liver tissue showed similar residue patterns as the diet, with the exception of chlorinated dibenzo-p-dioxin and dibenzofuran congeners that had a higher liver retention than pesticides, chlorinated biphenyls and brominated diphenylethers.
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| 37. |
- Carlsson, Lena, et al.
(författare)
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Cytoskeletal derangements in hereditary myopathy with a desmin L345P mutation
- 2002
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Ingår i: Acta Neuropathologica. - : Springer. - 0001-6322 .- 1432-0533. ; 104:5, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- Patients with abnormal accumulations of desmin have been described in myopathies with or without cardiac involvement. Desmin deposits were sometimes associated with abnormal aggregates of other cytoskeletal proteins. In the present study we present how the cytoskeletal organisation of desmin, nestin, synemin, paranemin, plectin and alphaB-crystallin is altered in skeletal muscles from a patient with a L345P mutation in the desmin gene. In general, accumulations of desmin together with synemin, nestin, plectin and alphaB-crystallin were present between myofibrils and beneath the sarcolemma. However, as the biopsy samples were very myopathic, large variability in fibre size and fibre maturation was seen, thus the myofibrillar content and the cytoskeletal organisation varied considerably. In cultured satellite cells from the patient, desmin aggregates were not observed in initial passages, but occurred over time in culture in the form of perinuclear, peripheral or cytoplasmic deposits. Nestin colocalised to the abnormal desmin deposits to a larger extent than did vimentin. alphaB-Crystallin was only present in cells with a disrupted desmin network. Plectin was altered in a subset of cells with a disrupted desmin network, whereas synemin and paranemin were not detected. We conclude that the L345P desmin mutation has a profound influence on the cytoskeletal organisation both in vivo and in vitro, which reflects the pathogenesis of the desmin myopathy.
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| 38. |
- De Leo, D, et al.
(författare)
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Repetition of suicidal behaviour in elderly Europeans : a prospective longitudinal study.
- 2002
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Ingår i: Journal of Affective Disorders. - 0165-0327 .- 1573-2517. ; 72:3, s. 291-5
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess any predictive factors for repeated attempted suicide and completed suicide in a 1-year follow-up on a sample of elderly European suicide attempters (60 years and over). From 1990 to 1993, 63 subjects completed the first interview and were recontacted after 1 year. At follow-up, eight subjects (12.7%) had taken their lives and seven (11.1%) had repeated at least one suicide attempt. On comparison of repeaters and non-repeaters, differences emerged in terms of death of the father in childhood and for mean Suicidal Intent Score. At the end of follow-up period, repeaters reported a more frequent desire to repeat suicidal behaviour and judged their mental health and social assistance received to be worse. Suicides and non-repeaters differed especially in relation to death of father during childhood and number of contacts with General Practitioner. Interpretation of the results must take into account the smallness of the test sample, the difficulties in obtaining complete data for the follow-up interview, the lack of a control group and a diagnosis formulated in a hospital consultation setting. The study confirms, however, the high risk of repetition of suicidal behaviour in the elderly. In old age suicidal ideation is often sustained over long periods of time and requests for help are addressed to relatives and GPs. An interesting finding is the more frequent death of the father during childhood among repeaters.
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| 39. |
- Hertegård, Stellan, et al.
(författare)
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Cross-linked hyaluronan used as augmentation substance for treatment of glottal insufficiency : safety aspects and vocal fold function
- 2002
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Ingår i: The Laryngoscope. - : Wiley. - 0023-852X .- 1531-4995. ; 112:12, s. 2211-2219
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To examine safety aspects and vocal fold function after vocal fold augmentation with a cross-linked hyaluronan derivative (hylan B gel) as compared with bovine collagen. STUDY DESIGN; A prospective, randomized trial. METHODS: Eighty-three patients with glottal insufficiency were treated with injection augmentation with hylan B gel and bovine collagen and were examined at 1, 6, and 12 months after treatment. Seventy patients with unilateral vocal fold paresis (n = 35) or atrophy (n = 35) were randomly assigned to receive either hylan B gel (n = 47) or collagen (n = 23) injections into one vocal fold. Thirteen patients with glottal insufficiency caused by scar defects or paresis resulting from malignant disease were included in a nonrandomized group and were treated only with hylan B gel. Evaluations were made from patients' subjective ratings (visual analogue scales), digitized videostroboscopic measurements, phonetograms, maximum phonation time, and phonation quotients. RESULTS: Twelve months after injections, the patients' self-ratings were significantly improved for both the hylan B gel and the collagen groups. In addition, the videostroboscopic measurements showed significantly improved glottal closure for both groups. However, for the hylan B gel group, vibration amplitude and glottal area variations were preserved, and this group showed significantly less resorption at the injected vocal fold edge. Furthermore, maximum phonation time had increased significantly for the hylan B gel patients (collagen, nonsignificant). No serious adverse events were observed; three patients injected with hylan B gel had temporary inflammation at the injection site, which resolved without sequelae. CONCLUSIONS: The results showed that both hylan B gel and collagen can be safely used for injection treatment of glottal insufficiency. Both treatments resulted in significantly improved voice as rated by the patients. However, the patients treated with hylan B gel showed better vocal fold status and longer maximum phonation time at 12 months after treatment as compared with patients treated with collagen.
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| 40. |
- Kaati, Gunnar, 1940-, et al.
(författare)
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Cardiovascular and diabetes mortality determined by nutrition during parents' and grandparents' slow growth period
- 2002
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Ingår i: European Journal of Human Genetics. - : Nature Publishing Group. - 1018-4813 .- 1476-5438. ; 10:11, s. 682-688
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Tidskriftsartikel (refereegranskat)abstract
- Overfeeding and overeating in families are traditions that are often transferred from generation to generation. Irrespective of these family traditions, food availability might lead to overfeeding, in its turn leading to metabolic adaptations. Apart from selection, could these adaptations to the social environment have transgenerational effects? This study will attempt to answer the following question: Can overeating during a child's slow growth period (SGP), before their prepubertal peak in growth velocity influence descendants' risk of death from cardiovascular disease and diabetes? Data were collected by following three cohorts born in 1890, 1905 and 1920 in Överkalix parish in northern Sweden up until death or 1995. The parents' or grandparents' access to food during their SGP was determined by referring to historical data on harvests and food prices, records of local community meetings and general historical facts. If food was not readily available during the father's slow growth period, then cardiovascular disease mortality of the proband was low. Diabetes mortality increased if the paternal grandfather was exposed to a surfeit of food during his slow growth period. (Odds Ratio 4.1, 95% confidence interval 1.33-12.93, P=0.01). Selection bias seemed to be unlikely. A nutrition-linked mechanism through the male line seems to have influenced the risk for cardiovascular and diabetes mellitus mortality.
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