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Biomedical subjects

P Kuusela

Publications and source records attributed to P Kuusela.

At least 37 records · Page 2Linked to original sources
PubMed1997

Adrenergic stimulation of lipoprotein lipase gene expression in rat brown adipocytes differentiated in culture: mediation via beta3- and alpha1-adrenergic receptors.

In order to investigate whether the positive effect of adrenergic stimulation on lipoprotein lipase (LPL) gene expression in brown adipose tissue is a direct effect on the brown adipocytes themselves, the expression of the LPL gene was investigated by measuring LPL mRNA levels in brown adipocytes, isolated as precursors from the brown adipose tissue of rats and grown in culture in a fully defined medium before experimentation. Addition of noradrenaline led to an enhancement of LPL gene expression; the mRNA levels increased as a linear function of time for at least 5 h and were finally approx. 3 times higher than in control cells, an increase commensurate with that seen in vivo in both LPL mRNA levels and LPL activity during physiological stimulation. The increase was dependent on transcription. The effect of noradrenaline showed simple Michaelis-Menten kinetics with an EC50 of approx. 11 nM. beta3-Agonists (BRL-37344 and CGP-12177) could mimic the effect of noradrenaline; the beta1-agonist dobutamine and the beta2-agonist salbutamol could not; the alpha1-agonist cirazoline had only a weak effect. The effect of noradrenaline was fully inhibited by the beta-antagonist propranolol and was halved by the alpha1-antagonist prazosin; the alpha2-antagonist yohimbine was without effect. An increase in LPL mRNA level similar to (but not significantly exceeding) that caused by noradrenaline could also be induced by the cAMP-elevating agents forskolin and cholera toxin, and 8-Br-cAMP also increased LPL mRNA levels. The increase in LPL gene expression was not mediated via an increase in the level of an intermediary proteinaceous factor. It is concluded that the physiologically induced increase in LPL gene expression is a direct effect of noradrenaline on the brown adipocytes themselves, mediated via a dominant beta3-adrenergic pathway and an auxiliary alpha1-adrenergic pathway which converge at a regulatory point in transcriptional control.

Adipose Tissue, Brown↗
PubMed1997

Plasma interleukin-8, interleukin-10, and E-selectin levels in neutropenic and non-neutropenic bacteremic patients.

Plasma interleukin-8 (IL-8) interleukin-10 (IL-10), and E-selectin concentrations were studied in 39 neutropenic and 30 non-neutropenic bacteremic patients; 54 nonbacteremic patients were analyzed as controls. Interleukin-8 concentrations were significantly higher in neutropenic than in non-neutropenic bacteremic patients (median 475 vs. 0 pg/ml, p < 0.0001). Median IL-8 and IL-10 levels were higher in bacteremic than in non-bacteremic patients (330 vs. 0 pg/ml, p < 0.0001 and 20 vs. 0 pg/ml, p = 0.04, respectively). In contrast, concentrations of IL-10 were similar in neutropenic and non-neutropenic patients. Median levels of E-selectin were not increased in any of the patient groups. Neutropenic bacteremic patients showed significantly lower concentrations of E-selectin than did non-neutropenic bacteremic patients (p < 0.0001). In conclusion, neutropenic bacteremic patients had significantly higher concentrations of IL-8 than non-neutropenic bacteremic patients. Levels of IL-10 were higher in bacteremic than in nonbacteremic patients, but neutropenic and non-neutropenic patients had similar levels of IL-10. Increased levels of E-selectin were not found in any of the patient groups, although neutropenic patients with bacteremia had lower concentrations than did non-neutropenic patients.

Adult↗
PubMed1996

Purification and characterisation of a plasmin-sensitive surface protein of Staphylococcus aureus.

Certain methicillin-resistant Staphylococcus aureus strains contain a 230-kDa cell-wall protein which is not present on the surface of other staphylococci. The presence of this 230-kDa protein is associated with a negative test result in commercial assays designed to detect fibrinogen-binding proteins and/or protein A on the staphylococcal surface. We have purified and partially characterised the 230-kDa protein from a lysostaphin digest of a non-agglutinating methicillin-resistant S. aureus strain. Partial amino acid sequence data obtained from the purified protein did not reveal any significant similarities to known proteins which indicates that the protein is novel. The 230-kDa protein was very sensitive to proteolysis; soluble plasmin, or plasmin formed on the bacterial-cell surface, rapidly degraded the 230-kDa protein to a 175-kDa form. The finding that the 230-kDa protein bound to lectins allowed its purification by affinity chromatography on immobilised wheat germ agglutinin. Furthermore, the degradation of the 230-kDa protein was associated with an increased adherence of non-agglutinating methicillin-resistant S. aureus cells to solid-phase fibronectin, fibrinogen or IgG.

Agglutination↗
PubMed1996

Interaction of Haemophilus influenzae with the mammalian extracellular matrix.

The adhesiveness of 2 unencapsulated nonfimbriated strains of Haemophilus influenzae, 23459 and 23330, and the encapsulated fimbriated strain 770235 to extracellular matrix (ECM) and to its isolated components was studied, as was the potential of H. influenzae plasminogen receptors to enhance degradation of ECM and bacterial penetration through basement membrane. All strains exhibited efficient adhesiveness to reconstituted basement membrane and to ECM from cultured human endothelial cells. Strains 23459 and 23330 efficiently adhered to immobilized laminin, fibronectin, and various collagens. Strain 770235 adhered efficiently to fibronectin and type I and III collagens and with low efficiency to laminin. With all 3 strains, plasmin generated on H. influenzae plasminogen receptors degraded laminin and fibronectin as well as ECM from human endothelial cells. Plasmin bound on H. influenzae cells also potentiated penetration of bacteria through a basement membrane preparation reconstituted on membrane filters. These results give evidence for a role of ECM adherence and plasminogen activation in the spread of H. influenzae through tissue barriers.

Bacterial Adhesion↗
PubMed1995

Plasma endotoxin and cytokine levels in neutropenic and non-neutropenic bacteremic patients.

Plasma endotoxin, tumor necrosis factor-alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), interleukin 1 receptor antagonist (IL-1ra), and interleukin 6 (IL-6) concentrations in 69 bacteremic patients were compared with those in 54 nonbacteremic patients suffering from suspected bacterial infections. Only three (11%) of the 27 patients with gram-negative bacteremia showed detectable levels of endotoxin. TNF-alpha was detected in 6% of the bacteremic patients and in none of the nonbacteremic patients. Median IL-6 levels were significantly higher in bacteremic than in nonbacteremic patients (55 vs. 0 pg/ml, p = 0.0008). IL-6 concentrations were similar in neutropenic and non-neutropenic bacteremic patients (median 55 vs. 74 pg/ml). In contrast, neutropenic bacteremic patients had significantly lower concentrations of IL-1ra than non-neutropenic bacteremic patients (250 vs. 1,950 pg/ml, p < 0.0001). Patients with fatal bacteremia had significantly higher concentrations of IL-6 and IL-1ra than the survivors (median, 450 vs. 40, p = 0.012 and 7,600 vs. 420 pg/ml, p = 0.0075, respectively). Determinations of endotoxin or TNF-alpha in patients with suspected bacteremia failed to offer clinically relevant data on the prognosis of these patients. IL-6 levels correlated with both the presence of bacteremia and the risk of death. Granulocytopenic patients with bacteremia had lower levels of circulating IL-1ra than patients with normal granulocyte counts, and these levels correlated with poor outcome.

Adult↗
PubMed1995

Preoperative serum levels of CEA and CA 242 in colorectal cancer.

Preoperative serum levels of CEA and CA 242 were determined in 260 patients with colorectal cancer and in 92 patients with benign colorectal diseases. The overall sensitivity of the CEA test was 43% and of the CA 242 test 39%. The corresponding specificities were 90% and 87% respectively, using 5 ng ml-1 as cut-off level for CEA and 20 U ml-1 for CA 242. The sensitivity of CEA was 26%, 32%, 38% and 77% for Dukes A, B, C and D colorectal cancer, and the sensitivity of CA 242 was 26%, 26%, 40% and 67%, respectively. The correlation between CEA and CA 242 was low. Concomitant elevation of both markers was seen in 5%, 12%, 18% and 59% of patients with Dukes A, B, C and D colorectal cancer, respectively. Of all the patients, 23% showed elevation of both the CEA and the CA 242 level, whereas CEA alone was elevated in 20% and CA 242 alone in 15% of the patients with colorectal cancer. Combined use of both markers raised the overall sensitivity from 43% to 58%, but reduced the specificity from 90% to 80%. The increase in sensitivity by combining the two markers was most marked in Dukes A, B and C colorectal cancer. Either or both of the markers were elevated in 46%, 46% and 60% of the patients respectively. The clinical value of combining CEA and CA 242 seems very promising and should be further investigated in prospective studies.

Adenoma↗
PubMed1995

Bacterial plasminogen receptors: in vitro evidence for a role in degradation of the mammalian extracellular matrix.

The potential of bacterium-bound plasmin to degrade mammalian extracellular matrix and to enhance bacterial penetration through basement membrane was assessed with the adherent strain SH401-1 of Salmonella enterica serovar Typhimurium. Typhimurium SH401-1 was able to bind plasminogen and to enhance the tissue-type plasminogen activator-mediated activation of the single-chain plasminogen to the two-chain plasmin. The end product, the enzymatically active, bacterium-bound plasmin activity, was also formed in a normal human plasma milieu in the presence of exogenous tissue-type plasminogen activator, indicating that plasmin was protected from the plasminogen activator inhibitors and plasmin inhibitors of plasma. Plasmin bound on Typhimurium cells degraded 125I-labeled laminin as well as 3H-labeled extracellular matrix prepared from the human endothelial cell line EA.hy926. The degradations were not seen with Typhimurium cells without plasminogen and were inhibited by the low-molecular-weight plasmin inhibitor aprotinin. Plasmin bound on Typhimurium cells also potentiated penetration of bacterial cells through the basement membrane preparation Matrigel reconstituted on membrane filters. The results give in vitro evidence for degradation of the mammalian extracellular matrix by bacterium-bound plasmin and for a pathogenetic role for bacterial plasminogen receptors.

Extracellular Matrix↗
PubMed1995

Tumor markers CA 125 and CA 19-9 in cord blood and during infancy: developmental changes and use in pediatric germ cell tumors.

Tumor markers CA 125 and CA 19-9 are elevated in a variety of malignancies in adult patients, but only little is known of their biology during gestation or infancy. We have addressed the developmental pattern of these carbohydrate antigens in pediatric patients by measuring their serum levels in 133 cord blood samples from the second through third trimester of gestation and in 39 infants aged less than 1.5 y. The serum concentrations of both markers revealed developmental changes, the levels being higher at earlier gestation (wk 24 through 37) than at term or during infancy. The clinical value of the markers was evaluated by monitoring 26 children with germ cell tumors; 14 benign and 2 immature teratomas, and 11 malignant germ cell tumors. Patients with immature sacrococcygeal teratomas showed constant and prolonged elevations of serum CA 125 and CA 19-9. In contrast, all but two children with mature teratomas had normal marker levels; these two patients with abnormally high serum CA 125 and CA 19-9 values for the first 4 postoperative weeks had a benign ovarian and ventricular teratoma, respectively. Of the 11 children with malignant germ cell tumors, serum CA 125 or CA 19-9 concentration was elevated in four patients at diagnosis and declined to normal within 2 wk after institution of therapy. Malignant recurrence in two patients was not associated with a reelevation of the CA 125 level. Taken together, our results demonstrate a developmentally regulated pattern of serum CA 125 and CA 19-9. The carbohydrate markers were usually inferior to alpha-fetoprotein in monitoring of germ cell tumors, but may be a useful adjunct in the follow-up of immature teratomas.

CA-125 Antigen↗
PubMed1994

CA 242, a new tumour marker for pancreatic cancer: a comparison with CA 19-9, CA 50 and CEA.

The serum expression of a novel tumour marker, CA 242, defined by monoclonal antibody C 242, was studied in 179 patients with pancreatic cancer. The results were compared with CA 19-9, CA 50 and CEA. CA 242 is a carbohydrate closely related, but not identical, to CA 19-9 and CA 50. The overall sensitivity of the CA 242 assay was 74%: 55% in stage I, 83% in stage II-III and 78% in stage IV disease. The specificity calculated from 112 patients with benign diseases was 91%. CA 19-9 had a higher sensitivity of 83%, but the specificity was only 81%. When comparing the markers by receiver operating characteristic analysis, the sensitivities were almost identical at all specificity levels. The CA 242 level was elevated in 7%, 15% and 7% of patients with benign pancreatic, biliary and liver disease respectively. The corresponding figures for CA 19-9 were 19%, 28% and 15% respectively. The sensitivity of CA 242 was higher than that of CA 50 and CEA at all specificity levels. In conclusion, tumour marker CA 242 seems to be a useful diagnostic tool for the diagnosis of pancreatic cancer, and is an alternative to CA 19-9. The advantage of CA 242 over CA 19-9 is its higher specificity when using the recommended cut-off levels of the assays.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

The prognostic value of preoperative serum levels of CA 19-9 and CEA in patients with pancreatic cancer.

The prognostic value of preoperative serum levels of CA 19-9 and CEA was evaluated in 160 patients with pancreatic cancer. The survival of patients whose tumour marker value was below a certain cut-off level was compared with the survival of those with a higher value using the log-rank test. The lowest cut-off level dividing patients into groups with significant difference in survival (P < 0.05) was determined by graphical analysis of chi-square values at different cut-off levels. If stage of disease was not taken into account, there was a significant difference in survival between patients with low vs high preoperative CA 19-9 and CEA levels. When patients were classified according to stage, a difference was found for CA 19-9 in stage II-III patients. Patients with preoperative CA 19-9 below 370 U ml-1 had a significantly better prognosis than those with a higher level (P < 0.05). In stage I and stage IV patients, no significant difference was found between the groups at any cut-off level. The analysis of CEA showed a significant difference in survival only in stage IV patients, with CEA above 15 ng ml-1 being associated with shorter survival. In conclusion, in patients with stage II-III disease, particularly in patients with a non-resectable tumour, in whom the exact spread of the disease may be difficult to evaluate even at operation, the preoperative CA 19-9 level seems to have a prognostic value.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

Rapid detection of methicillin-resistant Staphylococcus aureus strains not identified by slide agglutination tests.

Seventy-nine methicillin-resistant Staphylococcus aureus (MRSA) strains, isolated during 1980 to 1990, were classified as MRSA Aggl- (14 strains) and MRSA Aggl+ (65 strains) strains on the basis of test results in slide agglutination assays designed to detect fibrinogen-binding protein (clumping factor) and protein A on the staphylococcal surface. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that lysostaphin digests of MRSA Aggl- strains contained a high-molecular-weight protein which was not detected in digests of MRSA Aggl+ strains. Immunization of rabbits with an MRSA Aggl- strain produced an antiserum which agglutinated all MRSA Aggl- strains and also 64 of 65 MRSA Aggl+ strains. Only 1 of 68 coagulase-negative staphylococci showed agglutination in this assay. The anti-MRSA Aggl- antiserum reacted mainly with a 230-kDa staphylococcal surface protein but also with a 175-kDa protein, probably formed by proteolysis of the former and a few slightly smaller proteins. These could not be immunologically detected in lysostaphin digests of MRSA Aggl+ strains. Purified antibodies reacting with the 230-kDa protein agglutinated all MRSA Aggl- strains, indicating that the protein is located on the surfaces of staphylococci. The results suggest a tentative role for the 230-kDa protein or its fragments as a novel target to develop more efficient rapid identification methods for S. aureus, including MRSA.

Agglutination Tests↗
PubMed1994

Serum levels of oncofetal markers CA 125, CA 19-9, and alpha-fetoprotein in children with hereditary tyrosinemia type I.

Hereditary tyrosinemia type I (HTT-I) is an inherited metabolic disorder with severe liver disease and a high risk for hepatic malignancy. Patients with HTT-I are monitored with repeated analyses of serum amino acids, urine succinylacetone, and serum alpha-fetoprotein (AFP). Oncofetal markers CA 125 and CA 19-9 are elevated in serum of patients with various gastrointestinal diseases and malignancy. To study the biology of oncofetal antigens in tyrosinemia and to assess the possible usefulness of these markers in HTT-I, we studied serum concentrations of CA 125 (n = 160) and CA 19-9 (n = 188), together with AFP (n = 337), in serial samples from 10 patients. At early stages of the disease, most children with an acute type of disease had a remarkably elevated serum CA 125 concentration (153-1560 IU/L) that normalized gradually after the institution of therapy. Serum CA 125 levels may thus reflect acute metabolic imbalance in fulminant HTT-I. The patients with a chronic type of disease showed CA 125 levels within the normal range at diagnosis that slowly increased as the liver condition worsened. These concentrations, however, never reached values seen in acute HTT-I. Serum concentration CA 19-9 in HTT-I was mostly normal. Serum AFP levels fluctuated in all patients and positively correlated with tests for metabolic state and biliary function. A distinct increase in the serum AFP level was recorded in association with the detection of massive hepatocellular carcinoma and also preceded metabolic imbalance leading to porphyria crises.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Metabolism, Inborn Errors↗
PubMed1993

Immobilization of plasminogen on Escherichia coli flagella.

The interaction of plasminogen with flagella of Escherichia coli was investigated. Plasminogen bound to flagella purified from E. coli LE392, a commonly used cloning host, and E. coli IH3069, an O25H1 strain isolated from a case of newborn bacteremia. The binding was inhibited by the lysine analog epsilon-aminocaproic acid, suggesting involvement of the lysine-binding Kringle domains of plasminogen in the binding. Purified flagella enhanced the formation of plasmin activity in the presence of tissue-type plasminogen activator; a similar enhancement was observed with flagella-expressing LE392 cells.

Binding Sites↗
PubMed1993

Poor prognosis associated with elevated serum CA 19-9 level in advanced colorectal carcinoma, independent of DNA ploidy or SPF.

DNA ploidy, S-phase fraction (SPF) for the tumours, serum tumour markers such as carcinoembryonic antigen (CEA) and serum CA 19-9 and major clinical parameters were analysed as prognostic factors in 105 patients with advanced colorectal carcinoma. All 105 were treated with a three-drug schedule including low dose epirubicin and sequential methotrexate, 5-fluorouracil, followed by leucovorin rescue. In univariate analysis, gender, Karnofsky index, extent of metastases, presence of abdominal metastases, CEA and CA 19-9 correlated with survival. Age, presence of liver or of lung metastases, DNA ploidy or SPF were not significantly associated with survival. In stepwise multivariate analysis an elevated serum CA 19-9 level, a poor Karnofsky index and multiple sites of metastases were independent adverse prognostic factors. Based on the multivariate analysis, patients were grouped in three categories. Group 1 consisted of 32 patients with Karnofsky > or = 80, with a normal serum CA 19-9 level and a single site of metastases. Group 2 consisted of 48 patients with Karnofsky > or = 80 and with an elevated serum CA 19-9 level or multiple sites of metastases. Group 3 consisted of 14 patients with Karnofsky < or = 70. This classification gave a highly significant correlation with survival (chi 2 = 45.52, P < 0.001, log rank test). The median survival in group 1, group 2 and group 3 was 30.1 months, 13.5 months and 3.9 months, respectively. Based on these results we suggest that trials involving advanced colorectal cancer should include the measurement of serum CA 19-9 levels as one of the most important prognostic factors, but also include documentation of other independent prognostic factors.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1993

Hydrophobic domains affect the collagen-binding specificity and surface polymerization as well as the virulence potential of the YadA protein of Yersinia enterocolitica.

The YadA surface protein of enteropathogenic Yersinia species contains two highly hydrophobic regions: one close to the amino terminal, and the other at the carboxy-terminal end of the YadA polypeptide. To study the role of these hydrophobic regions, we constructed 66 bp deletion mutants of the yadA genes of Yersinia enterocolitica serotype O:3 strain 6471/76 (YeO3) and of O:8 strain 8081 (YeO8). The mutant proteins, YadAYeO3-delta 83-104 and YadAYeO8-delta 8O-101, lacked 22 amino acids from the amino-terminal hydrophobic region, formed fibrillae and were expressed on the cell surface. Bacteria expressing the mutated protein lost their auto-agglutination potential as well as their collagen-binding property. Binding to fibronectin and laminin was affected differently in the YeO3 and the YeO8 constructs. The deletion did not influence YadA-mediated complement inhibition. Loss of the collagen-binding property was associated with loss of virulence in mice. We also constructed a number of YadAYeO3 deletion mutants lacking the hydrophobic carboxy-terminal end of the protein. Deletions ranging from 19 to 79 amino acids from the carboxy terminus affected polymerization of the YadA subunits, and also resulted in the loss of the YadA expression on the cell surface. This suggests that the carboxy terminus of YadA is involved in transport of the protein to the bacterial outer surface.

Adhesins, Bacterial↗
PubMed1993

Proteolytic activity in leg ulcer exudate.

Twenty-five leg ulcer exudate samples from 17 patients with chronic non-healing venous leg ulcer were analyzed for proteolytic activity using radial caseinolysis procedures and zymographic analysis, and for fibronectin fragmentation using immunoblotting technology. Caseinolytic activity was detected in 21 of the 25 samples. A minority of them were inhibited (3 were totally, 6 partially inhibited) by aprotinin, a serine proteinase inhibitor, suggesting that proteinase(s) other than plasmin were also responsible for the caseinolysis. In zymographic analysis, 23 of the 25 samples showed positive reactions for enzyme activities comigrating with plasmin and urokinase-type plasminogen activator. Fibronectin fragmentation, another sign of proteolytic activity, was seen in all but 2 ulcers. No correlation was seen between bacterial infection or inflammatory cells and the above parameters in the wound fluid. Acute wound fluid collected from the donor sites of patients undergoing split skin grafting was used as a control. In the control specimens no proteolytic activity was found during the days following operation. These results show that there is proteolytic activity in the chronic ulcer exudate and support the possibility that the proteolytic activity and consequent fibronectin fragmentation may be related to the retarded epithelization and ulcer healing.

Adult↗
PubMed1992

Elevated CA19-9 as the most significant prognostic factor in advanced colorectal carcinoma.

Tumor markers such as carcinoembryonic antigen (CEA) and CA19-9 were analyzed as response indicators and prognostic factors in advanced colorectal carcinoma. Eighty-five patients participated in a phase II chemotherapy study from October 1984 to July 1990. A three-drug schedule was administered including low dose epirubicin and sequential methotrexate 5-fluorouracil, followed by leucovorin rescue. Serum specimens for CEA and CA19-9 were obtained prior to the initiation of chemotherapy, and subsequently at 4-6 weeks' intervals. In univariate analysis Karnofsky, the site of the primary tumor, the extent of metastases, the presence of abdominal or liver metastases, serum CEA (cut-off of 20 micrograms/l), and CA19-9 levels correlated with survival. In stepwise multivariate analysis an elevated CA19-9 level, a poor Karnofsky, and the presence of liver metastases were independent adverse prognostic factors. Tumors originating from the left colon had a better prognosis than the others. This was related to a higher response rate in this patient group. Serum CA19-9 level was the most significant prognostic factor whether it was entered as a continuous or as a dichotomized variable into the model. The median survival of patients with a normal CA19-9 level was 30.0 months (lower 95% confidence interval: 16.4 months; upper limit was not calculable), and with an elevated CA19-9 value 10.3 months (8.0-12.6 months, 95% confidence interval). Five of 85 patients had a complete response and 20 a partial response, the overall response rate being 29%. When compared with tumor shrinkage, "CEA response" and "CA19-9 response" had a sensitivity of 84% and 88% and specificity of 77% and 67%, respectively. In conclusion, serum CEA value seems to be the best tumor marker for response prediction, while CA19-9 level is one of the best available prognostic indicators in advanced colorectal carcinoma.

Adult↗