Biomedical subjects

S Ikonen

Publications and source records attributed to S Ikonen.

At least 19 recordsLinked to original sources

PubMed2001

Endorectal magnetic resonance imaging of prostatic cancer: comparison between fat-suppressed T2-weighted fast spin echo and three-dimensional dual-echo, steady-state sequences.

The aim of this study was to develop an endorectal MRI strategy for prostatic cancer. We evaluated the MR images from 44 consecutive prostatic cancer patients treated by radical prostatectomy. Each sequence from every examination was assessed separately with a specific tumor map drawn. Tumor localization, capsular penetration, and seminal vesicle invasion were marked on maps on the basis of T2 and DESS (dual-echo steady-state) sequences. Thirty patients also had T1-weighted images, and these were assessed with regard to possible tumor outgrowth. The maps were compared with histopathological findings from radical prostatectomy specimens. According to our study, DESS equaled T2 in every respect. No statistically significant differences between the sequences were found with respect to detecting either tumor localization, outgrowth, or seminal vesicle invasion. DESS is a potential new sequence in prostatic MRI as it has been proven to parallel the routinely used T2-weighted imaging.

Aged↗

PubMed2001

Optimal timing of post-biopsy MR imaging of the prostate.

PURPOSE: To assess the quantity and frequency of hemorrhage after prostatic biopsy. As post-biopsy blood products may interfere with interpretation of MR images, we also investigated the optimal timing for MR examination after biopsy. MATERIAL AND METHODS: Fifteen patients scheduled for prostatic biopsies were imaged with endorectal MR before and after the procedure. In addition, MR studies of 42 patients with prostate cancer were retrospectively analyzed. The amount of post-biopsy blood product and the degree of its interference with image interpretation were assessed. RESULTS: Of a total of 57 patients, 44 (77%) had visible post-biopsy hemorrhage. However, the presence of blood products were considered to interfere with interpretation of the images in only 12 (21%) cases. This disturbing effect seems to diminish after 21 days from biopsy. The total amount of blood clearly decreased after 28 days. CONCLUSION: Deferring MR imaging for at least 3 weeks after prostatic biopsy is advisable. T1-weighted images are necessary to rule out false-positive findings caused by post-biopsy hemorrhage.

Aged↗

PubMed2001

Prostatic MR imaging. Accuracy in differentiating cancer from other prostatic disorders.

PURPOSE: We assessed the accuracy of MR imaging in differentiating between cancer and other prostatic disorders, and evaluated the diagnostic criteria for various prostatic diseases. MATERIAL AND METHODS: A total of 74 endorectal coil MR studies were performed on 72 patients. Twenty patients had prostatic cancer, 20 benign prostatic hyperplasia (BPH), 4 acute bacterial prostatitis, 5 chronic bacterial prostatitis (2 also belonging to the previous category), 19 chronic non-bacterial prostatitis/chronic pelvic pain syndrome, and 6 were symptomless voluntary controls. All studies were interpreted by two experienced radiologists in random order. Radiologists were blinded to all clinical data including the age of the patients. Based on MR findings, both radiologists filled in a form covering diagnostic criteria and diagnosis. RESULTS: Accuracy in diagnosing prostate cancer was 74%. Sensitivity was 50% and specificity 83%, and positive and negative predictive values were 53 and 82%, respectively. Bacterial prostatitis showed some features similar to carcinoma. Abundant BPH rendered cancer detection more difficult. No diagnostic criterion was clearly better than the others. Interobserver agreement on the MR diagnosis ranged from moderate to good. CONCLUSION: Without knowledge of accurate clinical data, MR seems to be too insensitive in detecting prostate cancer to be used as a primary diagnostic tool.

Aged↗

PubMed2001

Screening of rotavirus and adenovirus infections during prolonged hospitalization in a neonatal unit.

UNLABELLED: Rotavirus and adenovirus infections in 308 infants hospitalized for longer than 1 wk, and cases with necrotizing enterocolitis, were screened in a neonatal unit during a 15 mo period, covering two rotavirus epidemics in the community. Altogether, 1020 stool samples were collected weekly until hospital discharge, and in necrotizing enterocolitis cases at the onset of symptoms, and tested for rotavirus and adenovirus by means of enzyme-linked immunosorbent assay. The positive samples were further analysed by polymerase chain reaction. Enzyme-linked immunosorbent assay revealed five adenovirus-positive cases, which were tested negative by polymerase chain reaction. Out of 16 necrotizing enterocolitis cases, one was adenovirus- and another rotavirus positive when tested by polymerase chain reaction, the latter having a concomitant Candida albicans septicaemia. CONCLUSION: Routine rotavirus and adenovirus screening in hospitalized neonates seems to be unnecessary. Viral diagnostic examinations should be considered in patients with necrotizing enterocolitis.

Adenoviridae Infections↗

PubMed2001

Renal follow up of premature infants with and without perinatal indomethacin exposure.

AIMS: To evaluate early childhood renal growth, structure, and function in children born at less than 33 weeks gestation and to investigate possible independent effects of perinatal indomethacin exposure. METHODS: A total of 66 children born at less than 33 weeks gestation, 31 of them with perinatal indomethacin exposure (study group) and 35 without (control group), were examined at 2-4 years of age. Serum cystatin C and protein; plasma creatinine, sodium, and potassium; urine protein, calcium:creatinine ratios, and alpha(1) microglobulin; and glomerular filtration rate (GFR) were determined. Renal sonography examinations were performed. RESULTS: The mean serum cystatin C concentrations were slightly higher in the control group than in the study group. Mean values of serum protein, and plasma creatinine and sodium did not differ between the groups, neither did median plasma potassium concentrations and urine protein:creatinine and calcium:creatinine ratios. None had tubular proteinuria. Abnormal GFR (<89 ml/min/1.73 m(2)) was found in one case in each group and renal structural abnormalities in five in each group. In logistic regression analysis the duration of umbilical artery catheter (UAC) use and furosemide treatment emerged as the significant independent risk factors for renal structural abnormalities. Furosemide treatment and assisted ventilation remained the risk factors associated with renal abnormalities in general-that is, functional and/or structural abnormal findings. CONCLUSION: Perinatal indomethacin does not seem to affect long term renal growth, structure, or function in children born at less than 33 weeks gestation. Duration of UAC use, furosemide treatment, and assisted ventilation may be correlated with later renal structural and functional abnormalities.

Blood Proteins↗

PubMed2001

A national short-term follow-Up study of extremely low birth weight infants born in Finland in 1996-1997.

OBJECTIVES: The aims of this prospective nationwide investigation were to establish the birth rate, mortality, and morbidity of extremely low birth weight (ELBW) infants in Finland in 1996-1997, and to analyze risk factors associated with poor outcome. PARTICIPANTS AND METHODS: The study population included all stillborn and live-born ELBW infants (birth weight: <1000 g; gestational age: at least 22 gestational weeks [GWs]), born in Finland between January 1, 1996 and December 31, 1997. Surviving infants were followed until discharge or to the age corresponding with 40 GWs. National ELBW infant register data with 101 prenatal and postnatal variables were used to calculate the mortality and morbidity rates. A total of 32 variables were included in risk factor analysis. The risk factors for death and intraventricular hemorrhage (IVH) of the live-born infants as well as for retinopathy of prematurity (ROP) and oxygen dependency of the surviving infants were analyzed using logistic regression models. RESULTS: A total of 529 ELBW infants (.4% of all newborn infants) were born during the 2-year study. The perinatal mortality of ELBW infants was 55% and accounted for 39% of all perinatal deaths. Of all ELBW infants, 34% were stillborn, 21% died on days 0 through 6, and 3% on days 7 though 28. Neonatal mortality was 38% and postneonatal mortality was 2%. Of the infants who were alive at the age of 4 days, 88% survived. In infants surviving >12 hours, the overall incidence of respiratory distress syndrome (RDS) was 76%; of blood culture-positive septicemia, 22%; of IVH grades II through IV, 20%; and of necrotizing enterocolitis (NEC) with bowel perforation, 9%. The rate of IVH grades II through IV and NEC with bowel perforation decreased with increasing gestational age, but the incidence of RDS did not differ significantly between GWs 24 to 29. A total of 5 infants (2%) needed a shunt operation because of posthemorrhagic ventricular dilatation. Two hundred eleven ELBW infants (40% of all and 60% of live-born infants) survived until discharge or to the age corresponding with 40 GWs. The oxygen dependency rate at the age corresponding to 36 GWs was 39%, and 9% had ROP stage III-V. Neurological status was considered completely normal in 74% of the surviving infants. The proportions of infants born at 22 to 23, 24 to 25, 26 to 27, and 28 to 29 GWs with at least one disability (ROP, oxygen dependency, or abnormal neurological status) at the age corresponding to 36 GWs were 100%, 62%, 51%, and 45%, respectively. Birth weight <600 g and gestational age <25 GWs were the independent risks for death and short-term disability. The primary risk factor for IVH grades II through IV was RDS. Low 5-minute Apgar scores predicted poor prognosis, ie, death or IVH, and antenatal steroid treatment to mothers with threatening premature labor seemed to protect infants against these. Some differences were found in the mortality rates between the 5 university hospital districts: neonatal mortality was significantly lower (25% vs 44%) in one university hospital area and notably higher (53% vs 34%) in another area. Furthermore, significant differences were also found in morbidity, ie, oxygen dependency and ROP rates. Differences in perinatal (79% vs 45%) and neonatal (59% vs 32%) mortality rates were found between secondary and tertiary level hospitals. CONCLUSION: Our study shows that even with modern perinatal technology and care, intrauterine and early deaths of ELBW infants are common. The outcome of infants born at 22 to 23 GWs was unfavorable, but the prognosis improved rapidly with increasing maturity. The clear regional and hospital level differences detected in survival rates and in short-term outcome of ELBW infants emphasizes that the mortality and morbidity rates should be continuously followed and that differences should be evaluated in perinatal audit procedures. (ABSTRACT TRUNCATED)

Adult↗

PubMed2000

Magnetic resonance imaging of prostatic cancer: does detection vary between high and low gleason score tumors?

BACKGROUND: Both Gleason score and prostate-specific antigen (PSA) concentration are prognostic factors for prostate cancer. We assessed our ability to localize cancer lesions based on Gleason scores and PSA values by endorectal coil magnetic resonance imaging (MRI). We also evaluated whether the size of the prostate affects tumor detectability. METHODS: We compared the findings of MRI and histopathological results of radical prostatectomy specimens from 63 patients; they were divided into four groups, based on Gleason score and also on serum PSA concentration. Furthermore, the possible effect of prostatectomy specimen weight on MRI interpretation was examined. RESULTS: A highly significant difference appeared in detection of cancer lesions based on their differentiation grade. No statistically significant difference existed between PSA groups in detection of tumors, but the large size of the prostate seemed to render image interpretation more difficult. CONCLUSIONS: Endorectal MRI detects poorly differentiated prostate cancer lesions more accurately than clinically insignificant tumors.

Aged↗

PubMed2000

Perinatal indomethacin treatment and neonatal complications in preterm infants.

UNLABELLED: To evaluate the incidence of neonatal complications among infants exposed to indomethacin antenatally, postnatally or both ante-and postnatally (combined), the records of 240 infants of gestational ages between 23 to 32 weeks were analysed retrospectively. Antenatal indomethacin treatment for longer than 2 days with a daily or cumulative dosage >/=150 mg correlated with a significantly higher incidence of grade I-II intraventricular haemorrhage. Combined exposure, cumulative antenatal exposure >/=150 mg and duration of antenatal exposure of more than 2 days was associated with necrotising enterocolitis and a cumulative exposure with sepsis. There was no independent association between indomethacin exposure and pneumothorax, bronchopulmonary dysplasia or respiratory distress syndrome. CONCLUSION: Preterm infants with exposure to antenatal indomethacin might be at increased risk of grade I and II intraventricular haemorrhage and those with both ante- and postnatal exposure at an increased risk of necrotising enterocolitis and sepsis.

Cerebral Hemorrhage↗

PubMed2000

Randomized trial comparing natural and synthetic surfactant: increased infection rate after natural surfactant?

The efficacy of a natural porcine surfactant and a synthetic surfactant were compared in a randomized trial. In three neonatal intensive care units, 228 neonates with respiratory distress and a ratio of arterial to alveolar partial pressure of oxygen <0.22 were randomly assigned to receive either Curosurf 100 mgkg-1 or Exosurf Neonatal 5 ml.kg-1. After Curosurf, the fraction of inspired oxygen was lower from 15 min (0.45 +/- 0.22 vs 0.70 +/- 0.22, p = 0.0001) to 6 h (0.48 +/- 0.26 vs 0.64 +/- 0.23, p = 0.0001) and the mean airway pressure was lower at 1 h (8.3 +/- 3.2 mm H20 vs 9.4 +/- 3.1 mm H20, p = 0.01). Thereafter the respiratory parameters were similar. The duration of mechanical ventilation (median 6 vs 5 d) and the duration of oxygen supplementation (median 5 vs 4 d) were similar for Curosurf and Exosurf. After Curosurf, C-reactive protein value over 40 mg l-1 occurred in 45% (vs 12%; RR 3.62, 95%CI 2.12-6.17, p = 0.001), leukopenia in 52% (vs 28%; RR 1.85, 95% CI 1.31-2.61, p = 0.001) and bacteraemia in 11% (vs 4%; RR 3.17, 95% CI 1.05-9.52, p < 0.05). We conclude that when given as rescue therapy Curosurf had no advantage compared with Exosurf in addition to the more effective initial response. Curosurf may increase the risk of infection.

Biological Products↗

PubMed2000

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Journal Article↗

PubMed1999

Effects of apamin on memory processing of hippocampal-lesioned mice.

We investigated the effects of acute i.p. injections of the Ca(2+)-dependent K(+) channel blocker, apamin, on water maze spatial navigation and radial arm maze performance in mice with partial hippocampal-lesions. In the radial arm maze, apamin 0.06 and 0.2 mg/kg dose-dependently reversed the lesion-induced defect. In the water maze, apamin 0.2 mg/kg alleviated the defect, but a lower dose 0.06 mg/kg was ineffective. At a higher dose, 0.4 mg/kg, apamin impaired the water maze performance. These results suggest that Ca(2+)-dependent K(+) channel blockers can alleviate the spatial reference memory and working memory impairment induced by partial hippocampal lesions.

Animals↗

PubMed1999

Characterization of learning and memory behaviors and the effects of metrifonate in the C57BL strain of mice.

In the near future, a number of transgenic mouse models with neuropathological characteristics of Alzheimer's disease are expected to become widely available. It will be important to characterize their behavior in models for learning and memory. As a first step, we have characterized normal, medial septal-lesioned and hippocampal-lesioned C57BL mice, in different behavioral tests, i.e., water maze spatial navigation, Y-maze and passive avoidance behavior. These experiments were complemented by an investigation of the effects of acute treatment with an acetylcholinesterase inhibitor, metrifonate, in these behavioral tests. Normal C75BL mice perform very well in the water maze and the Y-maze, but suboptimally in the passive avoidance task. Lesioning of the medial septum or the dorsal hippocampus clearly impaired the performance of the mice. In medial septal-lesioned mice, metrifonate stimulated spatial navigation and alleviated the loss of activity in the Y-maze and passive avoidance. In hippocampal-lesioned mice, metrifonate had no effect on spatial navigation. It is concluded that C75BL mice are useful for testing in classical models for learning and memory, and that septohippocampal pathology is very likely to induce cognitive deficits in some of these models.

Animals↗

PubMed1999

Tetrahydroaminoacridine and D-cycloserine fail to alleviate the water maze spatial navigation defect induced by hippocampal inactivation.

The present study examined the efficacy of single and combined treatment with an anticholinesterase, tetrahydroaminoacridine (i.p.), and a glycine-B site partial agonist, D-cycloserine (i.p.; a positive allosteric modulator of NMDA receptors), in alleviating the deficit in water maze spatial navigation induced by electrolytic lesion of the medial septum or lidocaine infusion into the dorsal hippocampi. In medial septum-lesioned rats, a combination of tetrahydroaminoacridine 3 mg kg(-1) and D-cycloserine 10 mg kg(-1) facilitated acquisition of the water maze test more effectively than either of the drugs alone. Single or combined treatment with tetrahydroaminoacridine 3 mg kg(-1) and D-cycloserine 10 mg kg(-1) had no effect on the water maze deficit induced by hippocampal lidocaine infusion. These results suggest that combined treatment with tetrahydroaminoacridine and D-cycloserine can effectively stimulate water maze spatial navigation, and that functioning of the hippocampus is a prerequisite for this effect.

Anesthetics, Local↗

PubMed1999

Short versus prolonged indomethacin therapy for patent ductus arteriosus in preterm infants.

OBJECTIVE: To evaluate whether a prolonged low-dose course of indomethacin would produce an improved closure rate and have fewer side effects compared with a short standard dosage schedule in the management of patent ductus arteriosus (PDA) in preterm infants. STUDY DESIGN: Sixty-one infants of gestational ages 24 to 32 weeks with a PDA confirmed with echocardiography were randomized to receive 0.2 to 0.1 to 0.1 mg/kg indomethacin in 24 hours (short course, n = 31) or 0.1 mg/kg every 24 hours 7 times (long course, n = 30). Echocardiography was done 3, 9, and 14 days after the treatment was started, and side effects were monitored. RESULTS: Primary PDA closure occurred more often in the short course group (94% vs 67%, P =.011), but the sustained closure rates were not different (74% vs 60%). Surgical PDA ligations were less frequent in the short course group than in the long course group. The short course group had a shorter duration of oxygen supplementation, less frequent symptoms of necrotizing enterocolitis, and a lower rate of urea retention. Mortality and other neonatal morbidity rates were similar. CONCLUSION: A prolonged low-dosage indomethacin regimen offers no advantage compared with a standard-dosage short course in the management of a hemodynamically significant PDA in preterm infants.

Cyclooxygenase Inhibitors↗

PubMed1999

Frequency and risk factors in bronchopulmonary dysplasia in a cohort of very low birth weight infants.

Frequency and perinatal risk factors in bronchopulmonary dysplasia (BPD) were retrospectively evaluated in a cohort of 242 infants with birth weights less than 1501 g born in one hospital in 1990-1994. At 28 days' postnatal age, 30.7% (59/192) of the infants alive received oxygen supplementation and showed typical radiological changes in chest X-rays. At 36 weeks' corrected gestation, 13.0% (24/184) of the survivors fulfilled these criteria. In multivariate analysis, low birth weight and gestational age, male sex, packed red cell infusions and long duration of ventilator therapy were correlated with an increased risk of BPD at 28 days' postnatal age. Only 49% of the infants with BPD had had respiratory distress syndrome, and 49% of them recovered from BPD by 36 weeks' corrected gestational age. Preeclampsia, low birth weight, rapid birth weight recovery, packed red cell infusions, long duration of ventilator therapy, patent ductus arteriosus and hyperoxia were associated with BPD beyond 36 weeks' corrected gestation. No infant born small for gestational age recovered from BPD before 36 weeks' corrected gestation. The frequency of BPD at 28 days' postnatal age seems to be increasing, but half of the patients recover before term. Factors other than respiratory distress syndrome, especially small birth weight, early weight gain and possibly intrauterine growth retardation are becoming more important risk factors of BPD beyond 36 weeks' corrected gestation.

Birth Weight↗

PubMed1999

Cord blood concentrations of vitamin A in preterm infants.

Plasma vitamin A concentrations were measured in cord blood samples from 56 infants of gestational ages < 33 weeks. Outcome was followed prospectively. Mothers' dietary habits and use of multivitamins during pregnancy were evaluated by means of a questionnaire. Vitamin A concentrations less than 1.05 micromol/l (low) were measured in 22, but levels below 0.7 micromol/l (deficient) only in two cases. The concentrations were not correlated with the infants' gestational ages. Infants with low concentrations were significantly more often multiplets compared to those with normal levels and the vitamin A concentrations of the multiplets were significantly lower than those of the singletons. The outcome measures used and the mothers' dietary habits and multivitamin use were similar in cases with low and normal vitamin A concentrations. Multiple gestation seems to be correlated with low plasma vitamin A concentrations in preterm infants at birth, and a complete assessment of vitamin A status to detect possible deficiency might be indicated in these cases.

Adult↗

PubMed1999

Very low birthweight, bronchopulmonary dysplasia and health in early childhood.

The impact of very low birthweight (<1500g) and bronchopulmonary dysplasia (BPD) on respiratory morbidity, on need of medical resources and rehabilitation at 2-8 y of age, and on the everyday life of the child's family was evaluated by means of a questionnaire addressed to parents of 143 very low birthweight children, 36 of whom had had BPD at 28 d postnatal age, and 131 term controls. In the preceding year, respiratory symptoms provoked by exercise, use of inhaled medications, regular follow-up visits and hospitalizations, need for physiotherapy, occupational therapy, technical aids and financial support from society had been more common in the very low birthweight groups compared to children born at term. Children with BPD suffered respiratory infections and needed antibiotic courses more frequently than term controls. Repeated antibiotic courses, physiotherapy and occupational therapy were more common among very low birthweight children with BPD than among those without. Concern for the child and the impact of the child's health on his or her everyday life and the parents' work and education were more often reported in target families than in term controls. Compared to term families, more parents in the BPD group felt that the child's health affected the pasttimes of other family members. To the families concerned, very low birthweight and BPD constitute a significant burden far beyond the neonatal period. Validated scales for the assessment of their quality of life are needed to develop supportive measures and to evaluate the effects of such interventions.

Adult↗

PubMed1998

D-cycloserine, a partial NMDA receptor-associated glycine-B site agonist, enhances reversal learning, but a cholinesterase inhibitor and nicotine has no effect.

The present study examined the efficacy of single and combined treatments with an anticholinesterase, tetrahydroaminoacridine, nicotine and a glycine-B site partial agonist, D-cycloserine, in alleviating the water maze reversal learning defect induced by a medial septal lesion. D-cycloserine (3 and 10 mg/kg) improved reversal learning. Tetrahydroaminoacridine (1 and 3 mg/kg) and nicotine (0.1 and 0.3 mg/kg) had no effect on reversal learning. A combination of tetrahydroaminoacridine 3 mg/kg or nicotine 0.3 mg/kg and D-cycloserine 10 mg/kg was not more effective than D-cycloserine 10 mg/kg alone in improving reversal learning. This suggests that stimulation of NMDA mechanisms may more effectively improve in medial septal-lesioned rats reversal learning processes than stimulation of cholinergic activity.

Alzheimer Disease↗