Biomedical subjects

B Nilsson

Publications and source records attributed to B Nilsson.

At least 145 records · Page 8Linked to original sources

PubMed1997

HLA class II genes in Latvian patients with juvenile rheumatoid arthritis.

PCR-based HLA genotyping was used to analyze the association of HLA-DR and -DQ genes in 127 juvenile rheumatoid arthritis patients and 111 population-based controls from Latvia. The results show DQA1*03 to be positively associated in overall patients and DRB1*01-DQA1*0101-DQB1*0501 to be negatively associated with JRA in overall patients and in polyarthritis patients compared to controls. These data indicate the immunogenetic heterogeneity in the JRA patients, in the disease subgroups and in different ethnic groups. Rheumatoid factor (RF) was assayed in patients (n = 119) and controls (n = 98). RF was present in patients (7/119, 6%) compared to controls (5/98, 5%). None of the DQA1, DQB1 alleles, DQ and DR-DQ haplotypes was associated in seropositive patients compared to seropositive controls. DR1-DQ5 (DQA1*0101-B*0501) was decreased in seronegative patients (11/111, 10%) compared to seronegative controls (24/105, 23%), but the difference was not significant after correction of the p value.

Alleles↗

PubMed1997

Phenotypic alterations in circulating monocytes induced by open heart surgery using heparinized and nonheparinized cardiopulmonary bypass systems.

In this study of 31 patients with coronary bypass surgery, we used flow cytometry to compare heparin-coated and noncoated cardiopulmonary bypass systems on leukocyte activation. We found significant differences between the groups during bypass, with activation of the complement system, measured as elevated levels of C3a desArg, upregulation of granulocyte beta2 integrin (CD11b), and a loss of circulating monocytes when noncoated systems were used. In both groups an early increase in the monocyte cell surface CD62L expression was obvious while the percentage of human leukocyte antigen (HLA)-DR positive monocytes did not alter. The morning after the operation, leukocytosis was present, together with a highly significant reduction in the monocyte expression of CD11b and HLA-DR, indicating the recruitment to the peripheral blood of cells with altered phenotypes. This alteration in phenotype on potent inflammatory cells may be one part of the impaired function of the immunological system reported after major surgery.

Adult↗

PubMed1997

Cancer survival in Estonian migrants to Sweden.

OBJECTIVE: To quantify the eventual extra loss of life incurred to cancer patients in Estonia compared with those in Sweden that was possibly attributable to differences in society. DESIGN: Population based survival of cancer patients in Estonia was compared with that of Estonian immigrants to Sweden and that of all cancer patients in Sweden. The cancer sites studied were female breast and ovary, male lung and prostate, and male and female stomach and colon. SETTING: Data on incident cases of cancer were obtained from the population based Swedish and Estonian cancer registries. PARTICIPANTS: Data from Estonian patients in Sweden, Estonian patients in Estonia, and patients from the total Swedish population were included in the study. MAIN RESULTS: Differences in survival among the three populations, controlling for follow-up time and age at diagnosis, were observed in breast, colon, lung, ovarian, and prostate cancers. The survival rates of Estonians living in Sweden and the total population of Sweden were better than that of the Estonians living in Estonia. For cancers of the breast and prostate, the excess mortality in the older age group (75 and above) was much greater in Estonia than in the other populations. CONCLUSIONS: Most differences in cancer survival between Estonian and Swedish populations studied could be attributed to a longer delay in diagnosis, and also to inferior treatment (including access to treatment) in Estonia compared with Sweden. Estonia's lag in socioeconomic development, particularly in its public health organisation and funding, is probably the main source of the differences observed.

Adolescent↗

PubMed1997

Multicenter evaluation of the Micral-Test II test strip, an immunologic rapid test for the detection of microalbuminuria.

OBJECTIVE: To assess the performance of the Micral-Test II immunologic test strip for the detection of microalbuminuria, a multicenter evaluation in eight European study sites was performed. RESEARCH DESIGN AND METHODS: Using both the Micral-Test II test strip and the routine method for the determination of albumin concentration, we investigated 2,228 urine samples from diabetic patients. Additionally, interperson variability, color stability, and possible interfering factors (temperature, pH, leucocyturia, erythrocyturia, and drugs) were tested. RESULTS: For a cutoff concentration of 20 mg/l with respect to the routine methods, a sensitivity of 96.7% and a specificity of 71% were calculated for the Micral-Test II test strip. The negative predictive value was 0.95, and the positive predictive value was 0.78, with a prevalence of positive samples (laboratory method) of 52%. The interperson variability of color interpretation showed 93% concordant readings. The interference study showed an influence of oxytetracycline, leading to higher readings. There was no interference from pH. A sample temperature of < 10 degrees C led to lower readings. In the case of samples with massive leucocyturia and erythrocyturia that may delete the chromatographic process, waiting an additional 1-2 min is needed before reading. CONCLUSIONS: The results of the multicenter evaluation show that the Micral-Test II test strip permits an immediate and reliable semiquantitative determination of low albumin concentrations in urine samples with an almost user-independent color interpretation.

Albuminuria↗

PubMed1997

Biochemical aspects of H. pylori adhesion.

In analogy with Vibrio cholerae and other toxigenic enteropathogens such as Yersinia enterocolitica it seems most likely today that H. pylori by specific surface proteins binds to epithelial cell receptors (Table 1) allowing the pathogen to deliver urease, vacuolating toxin and other toxic metabolites to cause tissue damage and inflammation (1-3). H. pylori as well as animal gastric pathogens as H. mustelae and H. felis have developed an efficient flagellar apparatus allowing rapid and efficient penetration of the gastric mucus layer (3). Most interestingly, flagellae seems to be synthesized in the late stage of growth before the switch of spiral-shaped organisms to coccoidal forms in a liquid medium.

Bacterial Adhesion↗

PubMed1996

Near tetraploid prostate carcinoma. Methodologic and prognostic aspects.

BACKGROUND: The clinical value of DNA ploidy analysis in prostate carcinoma has been an issue for investigation for more than 2 decades. In general, diploid or pseudodiploid tumors are associated with a favorable prognosis and aneuploid tumors with an unfavorable prognosis, irrespective of type of treatment. Tumors with DNA values in the tetraploid region (around 4c) present a diagnostic problem. Such DNA distributions may clearly represent aneuploid tumors with an unfavorable prognosis. However, a 4c distribution may conversely represent a tetraploid tumor (possibly a polyploid variant of the diploid tumor) with a favorable prognosis. Previous data from our laboratory indicate the existence of such a tetraploid subgroup. The goal of the current study was to investigate the diagnostic problem of 4c tumors in greater detail. METHODS: Ploidy classification of cytologic smears by image cytometry was performed in a retrospective study of 334 patients with hormonally treated prostate carcinoma. Follow-up time was 30 years or until death. RESULTS: Three ploidy types were defined: near-diploid (D type), near-tetraploid (T type), and highly aneuploid (A type). Tumors with a modal value within the tetraploid region were found in 27% (92 cases) of the total material. Of these, 9% were defined as T type and 18% as A type. Overall, 37% of the tumors were classified as D type, 9% as T type, and 54% as A type. Of the A type tumors, one-third had modal DNA values in the tetraploid (4c) region. Multivariate analysis showed a statistically significant difference between A type tumors and D and T type, but not between D type and T type. Both D and T type tumors progressed slowly and killed the patients 5 to 30 years after diagnosis, whereas A type tumors progressed rapidly and killed the patients within 6 years of diagnosis. CONCLUSIONS: By image cytometry, prostate carcinoma can be divided into three ploidy types: D, T, and A type. Biologically, however, the tumors fall into only two groups: low grade malignant, pseudodiploid tumors of D or T type, and high grade malignant, highly aneuploid tumors of A type.

Carcinoma↗

PubMed1996

Sympathetic and VIP-ergic control of calcium and bicarbonate transport in the feline gall bladder mucosa in vivo.

The regulation of calcium ion absorption by the gall bladder mucosa may be important for gall stone formation but this process is poorly understood. In this study performed in anaesthetized cats, the gail bladder lumen was perfused by a buffer equilibrated with 4% CO2 in air. During basal conditions, the pH and the [Ca2+] x [CO3(2-)] ion product decreased in the buffer when passing through the gall bladder lumen. The net absorption of calcium ions and fluid was significantly enhanced by stimulation of the splanchnic nerves. Intravenous infusion of vasoactive intestinal peptide (VIP) increased pH and the [Ca2+] x [CO3(2-)] ion product significantly in the buffer during the passage through the gall bladder lumen. Moreover, the basal fluid absorption was reversed to a net fluid secretion. In view of the presence of noradrenergic and VIP-immunoreactive nerve fibres in the gall bladder wall, and VIP-receptors on the gall bladder epithelial cells, the study suggests the existence of neural control mechanisms influencing the transport of Ca2+ by the gall bladder mucosa. These may be important to reduce potential calcium lithogenicity in the gall bladder lumen.

Animals↗

PubMed1996

C-erb-b2/int-2 amplification appears faster in breast-cancer patients receiving second-line endocrine treatment.

We have examined the appearance of c-erb-b2 and int-2 amplification in 2 different groups of breast-cancer patients. The groups differed with regard to their clinical status in that one group was receiving first-line endocrine treatment (tamoxifen) whereas the second was receiving second-line endocrine treatment (after failing on tamoxifen). The latter group of patients showed clinicallya a more advanced disease (higher frequency of stage-IV as compared to stage-III disease). Consecutive tumor samples were obtained using fine-needle biopsies from individual tumor lesions of each patient every second or third month. Median time from diagnosis to the last biopsy for patients receiving tamoxifen was 25 months and, for patients receiving second-line treatment, 55 months. The presence of amplification was determined using semi-quantificative PCR. We found that both genes developed amplification during tumor progression. The appearance of amplification was more pronounced in the clinically more advanced patients receiving second-line treatment (p = 0.018).

Aged↗

PubMed1996

[A small-group center. A model trial for activities of a center for rare diseases and syndromes at the National Hospital].

The Centre for Rare Disorders at the National Hospital is a trial project in connection with the Government's Plan of Action for the disabled. The intention is to establish nationwide facilities which in cooperation with local resources can provide both medical, pedagogical and social services for persons with rare disorders and their families. The work at the centre is based on a life span perspective and the goal is improved coping, independence and better quality of life. The centre gathers, adapts and spreads information on 15 rare disorders. Representatives from the user organisations ensure that the users have a strong influence on the management of the centre. It is hoped that systematic evaluation of the centre's activities will give an answer to the Government and to the host hospital as to whether the intentions and goals will be fulfilled or not during the project period.

Adolescent↗

PubMed1996

The mechanism of binding staphylococcal protein A to immunoglobin G does not involve helix unwinding.

Structural changes in staphylococcal protein A (SpA) upon its binding to the constant region (Fc) of immunoglobulin G (IgG) have been studied by nuclear magnetic resonance and circular dichroism (CD) spectroscopy. The NMR solution structure of the engineered IgG-binding domain of SpA, the Z domain (an analogue of the B domain of SpA), has been determined by simulated annealing with molecular dynamics, using 599 distance and dihedral angle constraints. Domain Z contains three alpha-helices in the polypeptide segments Lys7 to His18 (helix 1), Glu25 to Asp36 (helix 2), and Ser41 to Ala54 (helix 3). The overall chain fold is an antiparallel three-helical bundle. This is in contrast to the previously determined X-ray structure of the similar SpA domain B in complex with Fc, where helix 3 is not observed in the electron density map [Deisenhofer, J. (1981) Biochemistry 20, 2361-2370], but similar to the solution NMR structure of domain B, which is also a three-helical bundle structure [Gouda, H., et al. (1992) Biochemistry 31, 9665-9672]. In order to characterize possible secondary structural changes associated with IgG binding, far-UV CD spectra were collected for the Z domain, an engineered repeat of this molecule (ZZ), recombinant Fc from IgG subclass 1 (Fc1), recombinant Fc from IgG subclass 3 (Fc3), and mixtures of Z/Fc1, Z/Fc3, ZZ/Fc1, and ZZ/Fc3. Fc3 was included as a control for possible changes of the CD spectrum in the mixture of noncomplexed molecules, since SpA is known not to bind Fc3. From these CD spectra, it was concluded that the third alpha-helix in Z is not disrupted in its complexes with Fc1. Similar results were obtained for the ZZ molecule. However, in both Z and ZZ there are some perturbations in CD spectra at high energy wavelengths (i.e., lambda < 215 nm) accompanying complex formation. On the basis of the combined CD and NMR results, as well as previously described binding studies of Z mutant proteins to Fc1, we conclude that the Z domain maintains its three-helical bundle structure in the Z-Fc complex, though there may be a small structural change involved in the binding mechanism.

Amino Acid Sequence↗

PubMed1996

The serum albumin-binding domain of streptococcal protein G is a three-helical bundle: a heteronuclear NMR study.

Streptococcal protein G (SPG) is a cell surface receptor protein with a multiple domain structure containing tandem repeats of serum albumin-binding domains (ABD) and immunoglobulin-binding domains (IgBD). In this paper, we have analysed the fold of ABD. Far-UV circular dichroism analysis of ABD indicates high helical content (56%). Based on an analysis of nuclear magnetic resonance 13C secondary chemical shifts, sequential and short-range NOEs, and a few key nuclear Overhauser effects, we conclude that the ABD is a three-helix bundle. The structure of the ABD is, thus, quite different from the IgBD of protein G [Gronenborn, A.M. et al. (1991) Science 253, 657-661]. This strongly suggests that the ABD and the IgBD of SPG have evolved independently from each other. However, the fold of ABD is similar to that of the IgBD of staphylococcal protein A, possibly indicating a common evolutionary ancestor, despite the lack of sequence homology.

Amino Acid Sequence↗

PubMed1996

Higher frequency of gene amplification in breast cancer patients who received adjuvant chemotherapy.

BACKGROUND: Amplification of certain genes is involved in resistance to chemotherapy. The development of such amplification in patients by drug treatment has not yet been established. We have assessed the appearance of gene amplification in breast cancer patients with recurrent disease. One group of patients had previously received adjuvant chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil [CMF]) after surgery. The second group had not. All of these patients had developed recurrent disease and were receiving first-line endocrine treatment (tamoxifen). METHODS: Tumor cells were obtained from the recurrent carcinoma using fine-needle biopsies. Gene copy number was determined for dihydrofolate reductase and thymidylate synthase with semiquantitative polymerase chain reaction. Dihydrofolate reductase is involved in resistance to methotrexate (M) and thymidylate synthetase in resistance to 5-fluoropyrimidines (F), two targets for the CMF regime. RESULTS: We found that amplification of the examined genes develops in higher frequency among patients who previously received chemotherapy (p = 0.002). CONCLUSIONS: These findings provide strong evidence for gene amplification induced by drug treatment.

Adult↗

PubMed1996

Transient rise in intact parathyroid hormone concentration after surgery for primary hyperparathyroidism.

Two-site immunometric assays for determination of the level of intact parathyroid hormone (PTH) in serum have enabled detailed clinical studies of PTH secretion. Fifty-one patients with primary hyperparathyroidism were studied before surgery and 2 years after operation. PTH levels dropped to low values after operation. A rebound increase in PTH concentration occurred from 10 days to 3 months after surgery. Abnormally raised postoperative PTH concentrations were noted in 31 per cent of the patients, who had lower serum concentrations of ionized calcium (Ca2+) than the rest (P < 0.003). Before operation these patients had a more pronounced hyperparathyroidism than the others. At 2 years after surgery there was still a positive correlation between PTH concentrations before and after surgery (P < 0.001). The rebound increase in the level of PTH was a general phenomenon probably caused by low Ca2+ concentrations at the time of remineralization of bone. This phenomenon was transient. The positive correlation between preoperative and postoperative PTH concentrations shows that effects of hyperparathyroidism can remain for a long time after surgical cure.

Adult↗

PubMed1996

Frequency of radiographic procedures in an urban 62-year-old population in relation to general health, body build, bone mineral content, locomotor discomfort, occupational work load and socio-economic factors.

For 830 62-year-old residents of the city of Malmö records of radiographic examinations made over a period of 40 years at the Radiological Department of Malmö General Hospital and/or over 20-30 years at two private radiological departments in the city were reviewed. Radiographic examination had been undertaken in 92% of the residents, with on an average 16 examinations per resident. The most common examinations were of the chest in 63% of the residents followed by lower limb (58%) and spine (52%) examinations. In men the total number of radiographic examinations were negatively correlated to income, intelligence test results and social network and job satisfaction. Men with monotonous work and a more restricted latitude for decision-making at work, as well as men who were smokers had also had significantly more radiographic examinations. Single civil status and occupational work load had in men a positive correlation with the total number of radiographic examinations, as well as with serum levels of glutamyltransferase and uric acid levels. In women there was a negative correlation between radiographic examinations and teachers' rating of intelligence in childhood and bone mineral content, whereas job satisfaction, life success and triceps skinfold index (= subcutaneous fat tissue thickness) had a positive correlation with the total number of radiographic examinations. Women who took regular exercise (every week) had had significantly fewer radiographic examinations. Men and women with locomotor discomfort had a significantly higher consumption of not only musculoskeletal radiographic examinations but also other radiographic examinations.

Confidence Intervals↗

PubMed1996

High-level production of uniformly ¹⁵N- and ¹³C-enriched fusion proteins in Escherichia coli.

An approach to produce 13C- and 15N-enriched proteins is described. The concept is based on intracellular production of the recombinant proteins in Escherichia coli as fusions to an IgG-binding domain, Z, derived from staphylococcal protein A. The production method provides yields of 40-200 mg/l of isotope-enriched fusion proteins in defined minimal media. In addition, the Z fusion partner facilitates the first purification step by IgG affinity chromatography. The production system is applied to isotope enrichment of human insulin-like growth factor II (IGF-II), bovine pancreatic trypsin inhibitor (BPTI), and Z itself. High levels of protein production are achieved in shaker flasks using totally defined minimal medium supplemented with 13C(6)-glucose and (15NH4)2SO4 as the only carbon and nitrogen sources. Growth conditions were optimized to obtain high protein production levels and high levels of isotope incorporation, while minimizing 13C(6)-glucose usage. Incorporation levels of 13C and/or 15N isotopes in purifies IGF-II, BPTI, and Z were confirmed using mass spectrometry and NMR spectroscopy. More than 99% of total isotope enrichment was obtained using a defined isotope-enriched minimal medium. The optimized systems provide reliable, high-level production of isotope-enriched fusion proteins. They can be used to produce 20-40 mg/l of properly folded Z and BPTI proteins. The production system of recombinant BPTI is state-of-the-art and provides the highest known yield of native refolded BPTI.

Animals↗

PubMed1996

Histo-blood group p: biosynthesis of globoseries glycolipids in EBV-transformed B cell lines.

The genetic and biosynthetic basis of the histo-blood group P-system is not fully understood. Individuals with the rare p phenotype do not express the three glycolipid antigens (Pk, P and P1) of this system, probably because of deficiencies in glycosyltransferases involved in their biosynthesis. Iiuka et al. [Iiuka S, Chen SH, Yoshida A (1986) Biochem Biophys Res Commun 137: 1187-95], however, previously reported that detergent extracts from an EBV-transformed B cell line derived from a p individual did express the glycosyltransferase activity (Pk transferase) assumed to be missing in this blood group status. Here, we have reinvestigated the antigen expression and glycosyltransferase activities in two p individuals by analysing EBV-transformed cell lines as well as erythrocytes to confirm the blood group P status. The thin layer chromatography glycolipid profile of extracts from erythrocytes and EBV-transformed B cell lines showed characteristic accumulation of lactosylceramide and absence of Pk and P antigens. Glycosyltransferase activities of the B cell lines were analysed using glycolipid substrates and both extracts were found to contain lactosylceramide synthetase and P transferase activities but to be completely devoid of Pk transferase activity. The presented data indicate that p individuals, in contrast to previous reports, do not express a functional Pk glycosyltransferase.

Antigens, Surface↗

PubMed1996

Adhesion of Helicobacter pylori strains to alpha-2,3-linked sialic acids.

Helicobacter pylori is a human pathogen associated with gastritis and peptic ulcer. Adhesion properties of H. pylori to various structures have been described in the literature, including evidence for sialic acid-binding. To study the specificity and frequency of sialic acid-binding, fourteen H. pylori strains were investigated using haemagglutination with derivatized erythrocytes carrying sialic acids only on defined glycans and using haemagglutination inhibition assays. From these studies H. pylori strains can be grouped into sialic acid-dependent and sialic acid-independent classes. The sialic acid-dependent strains require alpha-2,3-linked sialic acid for haemagglutination. The potential roles of sialic acid-dependent adhesions for H. pylori-related infections are discussed.

Asialoglycoproteins↗

PubMed1996

Endotoxemia and complement activation after severe burn injuries--effects on leukocytes, soluble selectins, and inflammatory cytokines.

In this study we followed the development of an inflammatory response in a group of patients the first week after a burn injury. We detected elevated plasma endotoxin levels, on at least one occasion, in 6 of 8 patients. No endotoxin was detected in the two patients with the lowest total burned surface area (< or = 30%). We found evidence of complement activation as increased C3a levels, in parallel with a production of inflammatory cytokines (TNF-alpha, IL-6). The TNF-alpha levels increased significantly during the observation period, while the IL-6 levels were elevated already at admission, and remained so. Elevated levels of soluble E-selectin were detected, indicating endothelial cell activation. Despite the inflammatory response and a loss of inflammatory cells during the first days of the monitoring period, we found no evidence of cellular activation measured as increased expression of beta 2 integrin CD11b, nor increased plasma levels of soluble L-selectin.

Adolescent↗