PubMed Health⌕ Search

Biomedical subjects

P Riikonen

Publications and source records attributed to P Riikonen.

At least 19 recordsLinked to original sources
PubMed2003

Effects of gestational age and prenatal and perinatal events on the coagulation status in premature infants.

OBJECTIVE: To study prospectively the effects of prematurity and perinatal events on the coagulation status of premature infants. PATIENTS AND MAIN OUTCOME MEASURES: Blood samples from premature infants born before 37 gestational weeks were taken for analysis of coagulation factors II, V, VII, and X and platelet count. RESULTS: A total of 125 premature infants, 71 boys, were studied at the median postnatal age of 40 minutes (range 12-100). The lowest median activities of coagulation factors II, V, VII, and X and the platelet count were observed, as expected, in infants (n = 21) born at 24-27 weeks gestation. Twin B (n = 14) had lower median activities of coagulation factors II, V, VII, and X than twin A. Infants with evidence of mild asphyxia (Apgar score at 5 minutes < 7 or cord pH < 7.26) had significantly (p < 0.05) lower levels of coagulation factors II, V, VII, and X and platelet counts than infants without asphyxia. Infants who were small for gestational age (SGA) had significantly (p < 0.05) lower levels of coagulation factors V and VII and platelet counts than infants of appropriate size for gestational age. Other prenatal and perinatal variables examined (sex, maternal hypertension and/or pre-eclampsia, antenatal steroid use, mode of delivery, Apgar scores) did not show any significant associations with coagulation status, which may be explained by the small number of infants studied. CONCLUSIONS: The data strongly suggest that there are distinct differences in specific coagulation tests in different patient populations, which could assist in the identification of extremely preterm, SGA, or asphyxiated preterm infants who may be susceptible to haemorrhagic problems perinatally.

Asphyxia Neonatorum↗
PubMed2001

Both normal and leukemic B lymphocytes express multiple isoforms of the human Aiolos gene.

Aiolos is a chromatin remodeling transcription regulator that plays an antiproliferative role in B lymphocyte function. In contrast to the related Ikaros factors, mammalian Aiolos has not been reported to generate splice variants. In addition, although human leukemic lymphoblasts express non-DNA-binding Ikaros isoforms with potential dominant negative effect on other interacting factors,the role of Aiolos in human lymphoid disorders has remained obscure. To address the question, why Aiolos should delineate from Ikaros in such a marked way, we have here analyzed whether also human Aiolos could generate alternate isoforms. According to the results obtained, both normal and neoplastic B lineage cells were found to express at least five novel Aiolos variants. Also structurally dominant negative variants with less than three DNA-binding domains were identified. In conclusion, given the multiplicity of also human Aiolos isoforms and thereby the evidently more intricate contribution of Aiolos to the chromatin remodeling machinery, it is suggested, that not only Ikaros, but also Aiolos could participate in a more versatile manner in the regulation of B lymphocyte function.

Alternative Splicing↗
PubMed2001

Loss at 12p detected by comparative genomic hybridization (CGH): association with TEL-AML1 fusion and favorable prognostic features in childhood acute lymphoblastic leukemia (ALL). A multi-institutional study.

BACKGROUND: Genetic aberrations provide prognostic information in childhood ALL. The proportion of patients with detectable aberrations can be increased by combining G-banding with comparative genomic hybridization (CGH). PROCEDURE: We studied 79 children with ALL by CGH and G-banding, and explored the relationship of these findings to clinical features and outcome. RESULTS: CGH revealed DNA copy number changes in 57 patients (72%), 9 of whom had normal karyotype by G-banding. Gains were more frequent than losses, and changes of whole chromosomes more frequent than partial aberrations. Two frequent partial losses were found; at 9p and 12p. The 9 patients with loss at 12p were studied for the deletion of TEL (ETV6) gene and the fusion of TEL and AML1 genes by fluorescent in situ hybridization (FISH). Eight out of the 9 children with loss at 12p harbored the TEL-AML1 translocation and all 9 had the deletion of a nontranslocated TEL allele. All 9 had precursor-B phenotype and L1 morphology, and 8/9 had WBC below 50 x 10(9)/liter. All children were treated according to Nordic ALL protocols, had a good response to treatment based on day 15 bone marrow morphology, and 7 out of the 9 survived in continuous complete remission (median follow-up 74 months). CONCLUSIONS: CGH is a valuable tool in screening for genetic aberrations in childhood ALL. DNA copy number losses detected at 12p associate with TEL-AML1 fusion as well as with favorable prognostic features.

Adolescent↗
PubMed2001

BioWAP, mobile Internet service for bioinformatics.

UNLABELLED: We have developed a new Internet service, which provides mobile access to bioinformatics databases and software tools. The BioWAP service facilitates access to basic bioinformatics databases and analysis tools from everywhere without a PC or a laptop computer. Both open source bioinformatics program suites and Internet services, which are not designed for mobile Internet access, were utilized in the BioWAP service. AVAILABILITY: The BioWAP service starting page can be browsed with any WAP terminal from http://bioinf.uta.fi/wml/welcome.wml.

Computational Biology↗
PubMed2000

Novel immunodeficiency data servers.

The Internet contains scientific information in increasing amounts. It is possible to obtain the latest information, and Web services can easily be maintained and updated. We have set up three Internet services on immunodeficiencies. Immunodeficiency-related mutation infor mation is available in immunodeficiency mutation databases (IDbases). Currently 14 registries are distributed, including information about Bloom syndrome (BLMbase), X-linked agammaglobulinemia (BTKbase), X-linked and autosomal recessive chronic granulomatous diseases (CYBBbase for X-linked CGD, CYBAbase for p22(phox) deficiency, NCF1base for p47(phox) deficiency, NCF2base for p67(phox) deficiency), CD3gamma and CD3epsilon deficiencies (CD3Gbase, CD3Ebase), X-linked hyper-IgM syndrome (CD40Lbase), T-B+ severe combined immunodeficiency (JAK3base), V(D)J recombination defects (RAG1base, RAG2base), X-linked lymphoproliferative syndrome (SH2D1Abase), and ZAP-70 deficiency (ZAP70base). Information on laboratories analysing the genetic defects is collected to IDdiagnostics registry. Due to the rareness of immunodeficiencies there are very few laboratories performing genetic diagnostics. Such laboratories are listed in IDdiagnostics and physicians can use the registry to find a suitable laboratory for their diagnostic needs. Immunodeficiency Resource (IDR) is a comprehensive integrated knowledge base for all the information on immunode ficiencies, including clinical, biochemical, genetic, structural and computational data and analyses. All three services are available at http: //www.uta.fi/imt/bioinfo/.

Artificial Intelligence↗
PubMed2000

Cost analysis of the treatment of acute childhood lymphocytic leukaemia according to Nordic protocols.

Some attempts have been made to reduce the costs incurred in the therapy of leukaemia, but no studies are available regarding costs of the entire treatment in children with acute lymphocytic leukaemia (ALL). We analysed all the direct costs of treatment of 11 children with ALL diagnosed and treated in Kuopio University Hospital. The follow-up continued from diagnosis until the end of treatment for each patient. Patient treatment on the ward lasted for 84-210 d and in the outpatient clinic for 24-66 d, depending on the risk group. From 11-54 of the inpatient days were required for the treatment of infections. Total mean cost of the entire treatment was US $103250 (US $55196-166039) per patient, 53% of which were basic hospital costs and 47% patient-specific costs. Laboratory tests and radiology accounted for 18% of all direct costs and cytostatic drugs for 13%, but blood products accounted for only 4% of the total. Infections were the most important extra cause of costs, accounting for 18% of the mean total costs per patient. The complete treatment of a child with ALL came to a total of US $103250. However, since 80% of children with ALL are long-term survivors, the cost must be regarded as a good investment.

Adolescent↗
PubMed1999

Prospective and randomized comparison of early versus delayed prophylactic administration of granulocyte colony-stimulating factor (filgrastim) in children with cancer.

BACKGROUND: The prophylactic use of hematopoietic growth factors has been shown to reduce the duration of neutropenia and related complications encountered after anticancer chemotherapy. However, the optimal timing for initiation of granulocyte colony-stimulating factor (G-CSF) has not been established. PROCEDURE: We evaluated the clinical parameters of the early versus delayed start (+1 day vs. +5 days postchemotherapy) of filgrastim (G-CSF; 5 micrograms/kg) after 36 courses of anticancer chemotherapy in 18 children with cancer in randomized fashion. Each child received two identical anticancer chemotherapeutic courses followed by one early (group 1) and one delayed (group 2) administration of G-CSF. Filgrastim was administered until absolute neutrophil count (ANC) exceeded 1.0 x 10(9)/l. RESULTS: The mean duration of G-CSF therapy was 8.6 (range, 5-14) days in group 1 and 5.4 (range, 3-10) days in group 2 (P = 0.001). The mean duration of neutropenia (ANC < 1.0 x 10(9)/l) did not differ between the study groups (7.8 vs. 8.2 days). Seven infection episodes occurred in group 1 and eight in group 2, respectively. The mean number of hospital days on broad-spectrum antibiotics was 2.3 (range, 0-8) in group 1 and 3.3 (range, 0-11) in group 2 (ns). CONCLUSIONS: We conclude that the delayed start of filgrastim reduced the costs of this treatment, but was not followed by more prolonged neutropenia or febrile neutropenias.

Adolescent↗
PubMed1999

Acquired X-chromosome aneuploidy in children with acute lymphoblastic leukemia.

BACKGROUND: A cytogenetic study of 75 consecutive children with ALL revealed a normal karyotype, a low hyperdiploid karyotype (including 47-50 chromosomes), and a high hyperdiploid karyotype (including > 50 chromosomes) in 10, 12, and 33 patients, respectively. An acquired extra X-chromosome was detected at diagnosis by conventional cytogenetics in 29 (88%) of 33 children with a high hyperdiploid karyotype and in 4 (33%) of 12 children with a low hyperdiploid karyotype. X-chromosome aneuploidy was retrospectively studied by fluorescence in situ hybridization (FISH) in eight and 20 patients with a normal and a hyperdiploid karyotype, respectively. PROCEDURE: A classical cytogenetic study was performed according to standard methods. FISH with the centromeric probe specific to X-chromosome was used to study interphase cells of bone marrow or blood samples. RESULTS: An extra X-chromosome was found by FISH in all 13 patients with a high hyperdiploid or tetraploid, in 6 of 7 patients with a low hyperdiploid, and in none with a normal karyotype. Two children with a normal karyotype displayed monosomy X. Altogether, 57.3% of newly diagnosed children displayed X-chromosome aneuploidy. CONCLUSIONS: Out study indicates that X-chromosome aneuploidy may be the most common chromosome abnormality in childhood ALL. It can be detected in nearly all children with a high hyperdiploid karyotype and up to one-half of the patients with a low hyperdiploid karyotype. FISH with an X-chromosome centromeric probe is a rapid and simple tool to detect an abnormal clone at diagnosis in the majority of children with ALL and is useful in confirming remission in these patients.

Adolescent↗
PubMed1999

Reemphasis on lymphoblast L2 morphology as a poor prognostic factor in childhood acute lymphoblastic leukemia.

BACKGROUND: In childhood acute lymphoblastic leukemia (ALL), the relationship between lymphoblast L1/L2 morphology and prognosis is controversial. According to some studies L2 morphology is associated with poor prognosis, whereas in others the association disappears after adjustment for other known risk factors. PROCEDURE: We investigated the prognostic importance of lymphoblast L1/L2 morphology in childhood ALL treated with current Nordic ALL protocols in Finland. From the routine bone marrow (BM) aspirate and biopsy slides of 251 children with ALL diagnosed in 1990-1995, the blast cell morphology and early treatment responses were assessed blindly in a central review, using French-American-British (FAB) criteria with the Children's Cancer Group (CCG) modification. RESULTS: L1 morphology (>90% L1) was found in 197 (80%) children and L2 (>/=10% L2) in 49 (20%). Early treatment response was poorer in L2 than in L1: >5% blasts in the marrow on day 15 were seen in 27% of L2 as opposed to 12% of L1 (P = 0.048). The 6-year event-free survival (EFS) in the study population was 75%, 76% in L1 and 70% in L2 (P = 0.34). In the group with white blood cell count (WBC) below 50 x 10(9)/liter at diagnosis, the L2 morphology was associated with inferior survival: 6-year EFS 74% in L2 and 84% in L1 (P = 0.07), with 6-year overall survival (OS) 81% vs. 91% (P = 0.035), respectively. L2 morphology was not associated with any other adverse prognostic factor analyzed. CONCLUSIONS: With the intensive Nordic ALL protocols, lymphoblast L2 morphology is an independent poor prognostic factor, influencing both the early response to treatment and, in the low-WBC group, the ultimate outcome, and should be reemphasized in risk categorization of childhood ALL.

Adolescent↗
PubMed1999

Disturbance in bone turnover in children with a malignancy at completion of chemotherapy.

BACKGROUND: Osteoporosis and pathological fractures have been observed in children with a malignancy. The mechanisms of osteopenia in childhood malignancies have not been well established. The purpose of the present study was to evaluate changes in bone turnover and in bone hormonal metabolism in children with a malignancy at completion of their chemotherapy. PROCEDURE: Serum levels of human intact osteocalcin, type I collagen carboxyterminal propeptide (PICP), type I collagen carboxyterminal telopeptide (ICTP), 25-hydroxyvitamin D [25-(OH)-D], 1,25-dihydroxyvitamin D [1, 25-(OH)(2)-D], intact parathyroid hormone, insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), alkaline phosphatase, calcium, and phosphate were analyzed in 22 children with acute lymphoblastic leukemia and in 26 children with other malignancies. Results were expressed as Z-scores [mean (95% confidence intervals)] relative to healthy Caucasian-children. RESULTS: The marker of collagen degradation (ICTP) was significantly increased [1.43 (1.10-1.76), P < 0.0001] compared to reference values, whereas the markers of bone formation (PICP, osteocalcin) were not changed [0.07 (-0.55 to 0.49), 0.35 (-0.05 to 0.74), respectively, NS]. Serum 25-(OH)-D, 1,25-(OH)(2)-D, and calcium were significantly reduced [-0.65 (-0.87 to -0.42), -0.68 (-0.92 to -0. 42), -1.42 (-1.80 to -1.04), P < 0.0001, respectively]. CONCLUSIONS: Disturbance in bone turnover with low serum 25-(OH)-D, 1, 25-(OH)(2)-D, and calcium was observed in children with a malignancy at completion of their chemotherapy. A controlled study determining the possible benefits of vitamin D and calcium supplementation on bone turnover could be considered in these patients.

Adolescent↗
PubMed1999

Clinically symptomatic central venous catheter-related deep venous thrombosis in newborns.

The objective of this study was to evaluate the incidence of clinically symptomatic central venous catheter (CVC)-related deep venous thrombosis (DVT) in newborns and small infants and to try to identify clinical and genetic risk factors for catheter-related DVT among children with thrombotic complications. CVC was inserted in 44 consecutive infants (age range 0-90 d) during the period January 1990 to December 1995 in the neonatal intensive care unit (NICU) of Kuopio University Hospital in Kuopio. The symptoms of DVT were: syndrome of superior vena cava in 2, swelling at the CVC puncture site in 6 and repeated CVC obstructions in 2. The formation of DVT was verified by venography. Children with DVT (n = 10) had 26 (10-365, in total 623) catheter days compared with 9 d (1-155, in total 591) in patients without DVT (n = 26) (p < 0.005). The median (range) number of days from catheter insertion to diagnosis of DVT was 19 (7-210). CVC had to be removed from 11 (25%) children due to various complications. There was no DVT-related mortality. A positive family history with thromboembolic episodes at a young age was found in 3 of 10 families with a child suffering CVC-related DVT. The levels of coagulation inhibitors were evaluated at the age of 9-69 mo in all 10 (23%) children with CVC-related DVT. We detected no deficiencies in protein S, protein C or antithrombin III. One child was heterozygous for the point mutation (R506Q) in the factor V gene known to cause activated protein C resistance (APCR). We conclude that newborns with CVC are at great risk of DVT and that the aetiology of DVT can rarely be identified via measurements of coagulation inhibitors.

Blood Coagulation Disorders↗
PubMed1999

MUTbase: maintenance and analysis of distributed mutation databases.

MOTIVATION: To develop tools for the submission of mutations to databases and maintenance of locus-specific mutation databases. Advanced, integrated computer systems are needed to store and organize the increasing mutation information. RESULTS: The MUTbase program suite provides an easy, interactive and quality-controlled submission of information to mutation databases. For further study of the databases on the World Wide Web, a number of tools are provided. The program package also writes and updates a large number of Web pages, e.g. about the distribution and statistics of disease-causing mutations, and changes in restriction patterns.

Algorithms↗
PubMed1999

Reduced bone density at completion of chemotherapy for a malignancy.

OBJECTIVES: Osteoporosis and pathological fractures occur occasionally in children with malignancies. This study was performed to determine the degree of osteopenia in children with a malignancy at completion of chemotherapy. METHODS: Lumbar spine (L2-L4) bone mineral density (BMD; g/cm2) and femoral neck BMD were measured by dual energy x ray absorptiometry in 22 children with acute lymphoblastic leukaemia (ALL), and in 26 children with other malignancies. Apparent volumetric density was calculated to minimise the effect of bone size on BMD. Results were compared with those of 113 healthy controls and expressed as age and sex standardised mean Z scores. RESULTS: Patients with ALL had significantly reduced lumbar volumetric (-0.77) and femoral areal and volumetric BMDs (-1.02 and -0.98, respectively). In patients with other malignancies, femoral areal and apparent volumetric BMDs were significantly decreased (-0.70 and -0.78, respectively). CONCLUSIONS: The results demonstrate that children with a malignancy are at risk of developing osteopenia. A follow up of BMD after the completion of chemotherapy should facilitate the identification of patients who might be left with impaired development of peak bone mass, and who require specific interventions to prevent any further decrease in their skeletal mass and to preserve their BMD.

Absorptiometry, Photon↗
PubMed1999

Alterations in bone turnover and impaired development of bone mineral density in newly diagnosed children with cancer: a 1-year prospective study.

In the present study, longitudinal changes in bone mineral density, bone turnover, and bone hormonal metabolism were evaluated in newly diagnosed children with cancer. Lumbar spine (L2-L4) and femoral neck bone mineral densities (grams per cm2) were measured by dual energy x-ray absorptiometry in 28 children (age, 2.9-16.0 yr; median, 8.0 yr; 10 acute lymphoblastic leukemias, 18 solid tumors) at diagnosis and after a 1-yr follow-up. Apparent volumetric density (grams per cm3) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxyl-terminal propeptide (PICP), and type I collagen carboxyl-terminal telopeptide were measured serially during the study. Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, insulin-like growth factor I (IGF-I), and IGF-binding protein-3 were analyzed at diagnosis and at 1-yr follow-up. A significant decrease in femoral bone mineral density and apparent volumetric density was observed during the year after diagnosis [(mean (SD), -10.1% (8.8%) and -11.3% (8.1%) respectively; P < 0.01], whereas age- and sex-matched controls showed annual increments of +5.4% (7.7%; P < 0.01) and +0.7% (5.7%; P = NS) respectively. The markers of bone formation (PICP and OC) were significantly decreased at diagnosis. By the end of the follow-up, PICP and OC were normalized, whereas the marker of bone resorption (type I collagen carboxyl-terminal telopeptide) was significantly increased. Reduced levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and IGF-binding protein-3 were observed during the study. To conclude, increased bone resorption and impaired development of femoral bone density were observed in children with cancer during chemotherapy. Deficient accumulation of bone mass may lead to impaired development of peak bone mass and predispose children with cancer to increased risk of osteoporosis and diminished skeletal resistance to fractures later in life.

Absorptiometry, Photon↗
PubMed1999

Impaired development of bone mineral density during chemotherapy: a prospective analysis of 46 children newly diagnosed with cancer.

Osteopenia and osteoporosis are becoming increasingly recognized in children with cancer, though reasons for these changes are poorly understood. The purpose of the present study was to evaluate longitudinal changes in bone mineral density (BMD) and bone turnover in newly diagnosed children with a malignancy. Lumbar spine (L2-L4) and femoral neck bone mineral density (BMDareal, g/cm2) was measured by dual-energy X-ray absorptiometry in 46 children (age 2.9-16.0, median 8.0 years; 15 leukemias, 12 lymphomas, 19 solid tumors) at diagnosis, and after 6 months from the baseline. The apparent volumetric bone mineral density (BMDvol) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxy-terminal propeptide (PICP), and type I collagen carboxy-terminal telopeptide (ICTP) were analyzed at diagnosis, and during a 6-month follow-up. A significant decrease in lumbar BMDvol (-2.1%, p < 0.05), and in femoral BMDareal (-9.9%, p = 0.0001) and BMDvol (-8.5%, p = 0.0001) was observed after 6 months when compared with baseline measurements. The markers of bone formation (PICP, OC) were significantly decreased, and the marker of bone resorption (ICTP) was significantly increased at diagnosis as compared with normal values. By the end the follow-up, the levels of PICP and OC were normalized, whereas the level of ICTP continued to increase indicating that there was a negative balance in bone turnover. A deficient accumulation of bone mass might predispose children with a malignancy to impaired development of peak bone mass. A controlled study determining the benefits of an early intervention on bone turnover should be considered in these patients.

Adolescent↗
PubMed1998

BTKbase, mutation database for X-linked agammaglobulinemia (XLA).

X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by mutations in the gene coding for Bruton's agammaglobulinemia tyrosine kinase (BTK). A database (BTKbase) of BTK mutations has been compiled and the recent update lists 463 mutation entries from 406 unrelated families showing 303 unique molecular events. In addition to mutations, the database also lists variants or polymorphisms. Each patient is given a unique patient identity number (PIN). Information is included regarding the phenotype including symptoms. Mutations in all the five domains of BTK have been noticed to cause the disease, the most common event being missense mutations. The mutations appear almost uniformly throughout the molecule and frequently affect CpG sites that code for arginine residues. The putative structural implications of all the missense mutations are given in the database. The improved version of the registry having a number of new features is available at http://www. helsinki.fi/science/signal/btkbase.html

Agammaglobulinaemia Tyrosine Kinase↗
PubMed1998

Serum N-terminal atrial natriuretic peptide (NT-ANP) in the cardiac follow-up in children with cancer.

BACKGROUND: We studied serum N-terminal atrial natriuretic peptide (NT-ANP) in children during and after chemotherapy for cancer to determine its applicability in detecting cardiac dysfunction. Forty-three patients were receiving chemotherapy for malignancy. Forty-eight patients were off chemotherapy and survived between 0.9 and 13 (median 5) years after the diagnosis, receiving cumulative anthracycline doses between 0 and 600 (median 225) mg/m2. PROCEDURE AND RESULTS: Cardiac evaluation of the patients included measurement of serum NT-ANP, recording of ECG, and assessment of systolic and diastolic function of the heart by echocardiography. During chemotherapy, serum NT-ANP levels were higher than in controls but varied markedly in the same individuals. Serum NT-ANP levels showed no consistent increase in the weeks following anthracycline administration. In late follow-up, serum NT-ANP levels were higher than in age-matched controls (median (range), 0.22 (0.06-0.47) vs. 0.14 (0.06-0.27) nmol/l, respectively, P < .001). The subgroup of patients with bone marrow transplantation and/or cardiac irradiation had the highest NT-ANP concentrations (0.30 (0.20-0.45) nmol/l). CONCLUSIONS: Thus, serum NT-ANP measurements seemed to represent a useful contribution in the long-term cardiac follow-up of children after cancer. This blood test can readily be included to laboratory follow-up, is reasonably inexpensive and may decrease the need for more laborious tests of cardiac function. When there is ongoing chemotherapy, NT-ANP levels are influenced by a variety of factors that invalidate its routine use during this period.

Adolescent↗