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Biomedical subjects

A Ohlsson

Publications and source records attributed to A Ohlsson.

At least 73 records · Page 4Linked to original sources
PubMed2000

The influence of potato fibre on exocrine pancreatic secretions and on plasma levels of insulin, secretin and cholecystokinin in growing pigs.

The effect of a potato fibre preparation on exocrine pancreatic secretions and on gastrointestinal hormone levels in plasma was studied in three 8 weeks old piglets that were surgically fitted with a jugular vein catheter for blood sampling, a pancreatic duct catheter and a T-shaped duodenal cannula for collection of pancreatic juice. The animals were fed for 2 weeks a control diet (experimental period 1), thereafter for 2 weeks the control diet supplemented with 2% potato fibre (experimental period 2) and for another 2 weeks the control diet again (experimental period 3). Additionally, intraduodenal (i.d.) infusions of the experimental diet, the control diet and potato fibre as well as i.v. infusions of a solution containing cholecystokinin (CCK) and secretin were administered. Potato fibre in the diet evoked in tendency an increase in the volume of secretion of pancreatic juice and a significant increase both in the mean values of the total protein content and total activities of lipase, trypsin and alpha-amylase when compared to the control diet. The i.d. infusion of the control diet, experimental diet and fibre infusate as well as the i.v. administration of the hormone infusate led to a spontaneous secretory response of the exocrine pancreas. Besides gastrointestinal hormones, such as CCK, other factors such as short chain fatty acids may be involved in the regulation of the exocrine pancreas.

Animals↗
PubMed2000

Assessing residual renal function and efficiency of hemodialysis--an application for urographic contrast media.

BACKGROUND: In patients on hemodialysis with end-stage renal disease there is an increasing interest in measuring both residual renal function (RRF) and quantity and quality of dialysis because insufficient dialysis gives higher mortality. For that purpose we have measured clearances of two urographic iodine (I) contrast media (CM) with different molecular masses (iohexol 821 u and iodixanol 1, 550 u). These CM are filtered through glomeruli and dialysis membranes and have higher molecular masses than urea and creatinine and might represent the dialyzability of the hypothetic uremic toxins with a molecular mass of 300-5,000 u. METHODS: Thirteen patients (8 of them were anuric) immediately after hemodialysis received 15 ml iohexol (300 mg I/ml i.v.) and 2 weeks later in the same way 15 ml iodixanol (320 mg I/ml). Nine other patients (2 anuric) received CM after only one dialysis; 8 got iohexol and 1 got iodixanol. After the CM injections the iodine concentrations were measured with X-ray fluorescence in blood and, when available, urine during the following 2 days including both the start and end of the next dialysis. Eighteen patients after two dialysis sessions, 2 weeks apart, received 10 ml iohexol i.v., and a single blood sample was taken at the start of the next dialysis 2 days later to determine RRF alone. RESULTS: In the 10 anuric patients the extrarenal clearances (mean +/- SD) were 2.5 +/- 1.1 and 2.7 +/- 1.1 ml/min/1.73 m(2) for iohexol and iodixanol, respectively. In patients with RRF good correlations were demonstrated between body clearance, based on two blood samples, and renal clearance of CM. Good correlations (r(2) = 0.853 for iohexol, r(2) = 0.933 for iodixanol) were noted between two-sample and single-sample body clearances. Repeated single sample iohexol clearances gave a coefficient of variation of 15%. During dialysis the clearances of iohexol and iodixanol were, respectively, 69 +/- 16 and 58 +/- 11 ml/min/1.73 m(2) when calculated from a single-pool model (hemodialysis clearance of CM from plasma). A median increase (rebound) of CM concentrations in plasma 45 min dialysis was 8% for iodixanol and 18% for iohexol. When the CM concentration 45 min after dialysis was used, the clearance values were by 8-10% lower and represented the hemodialysis clearance of CM from the extracellular compartments. The dialysis eliminations of iohexol and iodixanol were similar to that of urea, measured as percentage reduction of serum levels during dialysis. CONCLUSIONS: A single injection of CM at the end of dialysis followed by a single blood sample at the start of the next dialysis gives total body clearance, i.e., an estimation of the RRF. An additional blood sample at the end of the next dialysis gives dialysis efficiency.

Adult↗
PubMed2000

Variations in practice and outcomes in the Canadian NICU network: 1996-1997.

BACKGROUND: Previous reports of variations in outcomes among neonatal intensive care units (NICUs) examined only specific subpopulations of interest (eg, very low birth weight [VLBW] infants <1500 g of birth weight [BW]). OBJECTIVES: We report on current practice and outcomes variations in a population-based national study of Canadian NICUs from January 8, 1996 to October 31, 1997. METHOD: Information on 20 488 admissions to 17 tertiary level NICUs across Canada was prospectively collected by trained abstractors using a standard manual of operations and definitions. Data were verified and analyzed in concert with a steering committee comprising experienced researchers and neonatologists. Patient information included demographic information, antenatal history, mode of delivery, problems at delivery, status of infant and problems at birth, illness severity (Clinical Risk Index for Babies, Score for Neonatal Acute Physiology, Score for Neonatal Acute Physiology-Version II), therapeutic intensity (Neonatal Therapeutic Intensity Scoring System [NTISS]), selected NICU practices and procedures, use of technology and resources, and selected patient outcomes. Patients were tracked until death or discharge home. RESULTS: The mean number of annual admissions to an NICU was 657, with 26% outborn infants. Fifty-three percent were <2500 g BW, 20% were <1500 g BW (VLBW), and 65% were preterm (<38 weeks' gestational age [GA]). Only 2% of mothers received no prenatal care. Antenatal steroids were given to 58%, but there was wide variation in use (23%-76%). Congenital anomalies were present in 14%, and 4% were small for GA (less than the third percentile). Admission illness severity was lowest among infants 33 to 37 weeks of GA and correlated with risk of death. Ninety-six percent of patients survived until discharge, but fewer survived at lower GA. No infant <22 weeks' GA survived. Seven percent of infants had at least 1 episode of infection, but 75% received antibiotics in the NICU. Forty-three percent received respiratory support, and 14% received surfactant. Nitric oxide was given to 150 term infants and to 102 preterm infants. Selected outcomes of VLBW infants were: survival rate (87%); chronic lung disease (26%); >/=stage 3 retinopathy of prematurity (ROP; 11%); >/=grade 3 intraventricular hemorrhage (IVH; 10%); nosocomial infection (22%); necrotizing enterocolitis (NEC; 7%). Sixty-nine percent of VLBW infants survived without major morbidity (>/=grade 3 IVH, chronic lung disease, NEC, >/=grade 3 ROP). The mean duration of NICU stay was 19 days. Forty-seven percent of infants were discharged from the hospital, and 43% were retrotransferred to a community facility before discharge home. Significant variation in practices and outcomes were observed in all aspects of NICU care. CONCLUSION: This study provides population-based information about NICU outcomes. Significant variation in NICU practices and outcomes was observed despite Canada's universal health insurance system. This national database provides valuable information for planning research, allocating resources, designing health and public policy, and serving as a basis for longitudinal studies of NICU care in Canada.

Birth Weight↗
PubMed2000

[Multicenter randomized trial of amnioinfusion].

Meconium staining of the amniotic fluid in labor is a frequent problem that is associated with an increase in the risk of neonatal and maternal morbidity. Amnioinfusion is a simple technique that is designed to prevent neonatal and maternal morbidity associated with meconium. Preliminary studies indicate that amnioinfusion is a promising approach to the prevention of such complications of labor. However, further research is required. The primary objective of this multi-centre randomized controlled study is to determine if amnioinfusion for thick meconium stained amniotic fluid results in a reduction in perinatal death or moderate to severe meconium aspiration syndrome. We will also assess the effects of amnioinfusion on other indicators of neonatal morbidity and on cesarean section. The study includes an evaluation of womens views on their childbirth experience and an economic evaluation of a policy of amnioinfusion The study will be achieved with the collaboration of approximately 50 obstetrical centres from across Canada, US, Europe, South America and South Africa. This multicentre trial will provide urgently needed information on the efficacy and effectiveness of amniofusion for the indication of meconium stained amniotic fluid.

Amniotic Fluid↗
PubMed1999

A patent ductus arteriosus is associated with reduced middle cerebral artery blood flow velocity.

UNLABELLED: The study objective was to determine the effect of a patent ductus arteriosus (PDA) on cerebral blood flow velocity in ventilated, very low birth weight neonates, in the first 5 days of life. Sonography of the right middle cerebral artery and ductus arteriosus was performed using a colour Doppler technique. Statistical analysis was by stepwise regression. Thirty-one neonates without and 43 with a PDA, mean (SD) birth weight 1004 g +/- 192 and 1071 g +/- 227 respectively, were studied. The end diastolic and mean velocities were reduced (P = 0.008 and P = 0.129) and the resistive index was increased (P = 0.047) by a PDA. pH was inversely related to end diastolic and mean velocities (P = 0.015 and P = 0.003), suggesting that low pH may increase cerebral artery blood flow velocity. CONCLUSION: A patent ductus arteriosus reduces middle cerebral artery blood flow velocity in very low birth weight neonates.

Blood Flow Velocity↗
PubMed1999

Tocolytics for preterm labor: a systematic review.

OBJECTIVE: To examine the effectiveness of any tocolytic compared with a placebo or no tocolytic for preterm labor. DATA SOURCES: We checked MEDLINE (1966-1998) and the Cochrane Controlled Trials Register for articles, using the search terms "randomized controlled trial" (RCT), "preterm labor," "tocolysis," "betamimetics," "ritodrine," "terbutaline," "hexaprenaline," "isoxuprine," "prostaglandin synthetase inhibitors," "indomethacin," "sulindac," "calcium channel blockers," "nifedipine," "oxytocin receptor blockers," "atosiban," "nitroglceride," and "magnesium sulfate." METHODS OF STUDY SELECTION: We included all RCTs that compared effect of a tocolytic with a placebo or no tocolytic in women in preterm labor, and reported perinatal, neonatal, or maternal outcomes. Studies were excluded if loss to follow-up exceeded 20% of those originally enrolled, or if data were not reported on a per-patient-treated basis. Eighteen of 76 articles retrieved met the inclusion criteria. TABULATION, INTEGRATION, AND RESULTS: Two authors independently reviewed the articles and abstracted the data. Discrepancies were resolved by consensus. Meta-analyses (odds ratio [OR] and 95% confidence interval [CI]) were done for each outcome for all trials and for specific types of tocolytic therapy when possible. Tocolytics decreased the risk of delivery within 7 days (OR 0.60, 95% CI 0.38, 0.95). Betamimetics, indomethacin, atosiban, and ethanol, but not magnesium sulfate, were associated with significant prolongations in pregnancy. Tocolytics were not associated with improved perinatal outcomes. Maternal side effects significantly associated with tocolytic use were palpitations, nausea, tremor, chorioamnionitis, hyperglycemia, hypokalemia, and need to discontinue treatment. CONCLUSION: Although tocolytics prolong pregnancy, they have not been shown to improve perinatal or neonatal outcomes and have adverse effects on women in preterm labor.

Clinical Trials as Topic↗
PubMed1999

The effect of indomethacin tocolysis in preterm labour on perinatal outcome: a randomised placebo-controlled trial.

OBJECTIVE: To determine whether indomethacin tocolysis in preterm labour is associated with a better perinatal outcome than placebo. DESIGN: A randomised placebo-controlled trial. SETTING: Two university teaching hospitals with level three neonatal intensive care units. POPULATION: Women in preterm labour with intact membranes between 23 and 30 weeks of gestation. METHODS: Random allocation to tocolysis with indomethacin (50 mg followed by 25 mg 6 hourly for 48 hours) or placebo in a double-blind fashion. MAIN OUTCOME MEASURES: The primary outcome, perinatal mortality or severe neonatal morbidity, was defined as perinatal death, necrotising enterocolitis, bronchopulmonary dysplasia, intraventricular haemorrhage or peri-ventricular leucomalacia. Data were analysed using odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: Between March 1995 and February 1996, 34 women (39 babies) were recruited. The baseline characteristics of the two groups were similar. No patient was lost to follow up. In the indomethacin group, gestation was prolonged by > 48 hours in 13/16 (81%) of women vs 10/18 (56%) in the placebo group. The incidence of perinatal mortality or severe neonatal morbidity was not significantly different between the groups, but occurred in twice as many babies in the indomethacin group as in the placebo group--6/19 (32%) vs 3/20 (15%) OR (95% CI) 2.62 (0.44-18.8). There was one perinatal death, of a baby delivered at 24 weeks of gestation. This occurred in the indomethacin group. CONCLUSION: There is no evidence that indomethacin tocolysis is beneficial, and further trials are needed to assess the impact of indomethacin tocolysis in preterm labour.

Adult↗
PubMed1999

Does endothelin-1 reduce superior mesenteric artery blood flow velocity in preterm neonates?

AIM: To compare plasma endothelin-1 (ET-1) concentrations in preterm neonates from pre-eclamptic and normal mothers; and to evaluate whether ET-1 has a role in altered arterial blood flow velocity. METHODS: Umbilical arterial blood and neonatal arterial blood were sampled on days 1 and 3 for gas analysis and measurement of plasma ET-1. Doppler ultrasonography of the middle cerebral, renal, and superior mesenteric arteries (SMA) was performed. RESULTS: Neonates in the pre-eclampsia (n = 18) and control (n = 18) groups had mean (SD) gestational ages of 31.1 (2.5) weeks and 30.4 (2.1) weeks; their birth-weights were 1432 (SD 676) g and 1692 (SD 500) g, respectively. In the pre-eclampsia group mean umbilical arterial PO2 was lower--1.88 (0.75) kPa compared with 3.27 (1.41) kPa (p < 0.01)--and mean plasma ET-1 concentration was higher in the umbilical artery--40.6 (SD 15.0) compared with 30.5 (SD 13.8) pg/ml (p = 0.04) and day 1 blood--54.9 (35.0) pg/ml compared with 33.6 (14.6) pg/ml (p = 0.03). Middle cerebral artery peak systolic velocity was higher and SMA time averaged, peak systolic, and mean peak velocities were lower in the pre-eclampsia group. SMA time averaged velocity was inversely related to plasma ET-1 concentration. CONCLUSION: The association between increased production of ET-1 and reduction in SMA time averaged velocity suggests a possible mechanism for hypoperfusion of the intestinal wall in neonates.

Blood Flow Velocity↗
PubMed1999

Prediction of perinatal outcome in fetuses suspected to have intrauterine growth restriction: Doppler US study of fetal cerebral, renal, and umbilical arteries.

PURPOSE: To determine and compare the diagnostic performance of fetal middle cerebral (MCA), renal (RA), and umbilical (UA) arterial Doppler ultrasonography (US) for prediction of adverse perinatal outcome in suspected intrauterine growth restriction (IUGR). MATERIALS AND METHODS: Two hundred ninety-three small-for-gestational age fetuses (24-39 weeks at recruitment and US-estimated weight or abdominal circumference below 10th percentile) were prospectively examined with Doppler US of the UA, MCA, and RA. Clinicians were blinded to MCA and RA Doppler measurements. RESULTS: Seventy-six fetuses (25.9%) had at least one major or minor adverse perinatal outcome. Major outcomes included stillbirth, neonatal death, neurologic complication, and necrotizing enterocolitis. The MCA pulsatility index (PI), compared with the UA PI and RA PI, was more sensitive (72.4% vs 44.7% and 8.3%) but less specific (58.1% vs 86.6% and 92.6%) in predicting adverse outcome. The UA PI had the highest positive likelihood ratio (ratio, 3.3); the MCA PI had the lowest negative likelihood ratio (ratio, 0.48). When gestational age at the first Doppler US examination was less than 32 weeks, the MCA PI had a sensitivity of 95.5% and negative predictive value of 97.7% for major adverse outcome (negative likelihood ratio, 0.10). CONCLUSION: In suspected IUGR, while an abnormal UA PI is a better predictor of adverse perinatal outcome than an abnormal MCA or RA PI, a normal MCA PI may help to identify fetuses without major adverse perinatal outcome, especially before 32 weeks gestational age.

Brain↗
PubMed1999

Antenatal steroids to prevent respiratory distress syndrome: multiple gestation as an effect modifier.

BACKGROUND: To determine the effect of antenatal steroids on the incidence of respiratory distress syndrome and the need for surfactant in low-birth-weight infants (501-1500 grams). METHODS: A 6 year cohort of 946 infants (396 received complete steroids and 550 received no steroids) was studied for the occurrence of respiratory distress syndrome and the need for surfactant following antenatal steroid therapy. A stratified analysis identified confounding baseline characteristics or effect modifiers. The covariates used were multiple birth, maternal race, sex, mode of delivery, Apgar score <7 at 5 minutes, birth weight and gestational age. A multivariate logistic regression model was used to adjust odds ratios simultaneously for all statistically significant covariates. RESULTS: Multiple gestation and race were effect modifiers. The reduction in RDS was greatest among singleton infants of black mothers with no significant reduction for multiple gestation white infants. The need for surfactant following steroids was reduced only in the group of singletons of other race (not black or white). CONCLUSION: In this retrospective analysis of cohort data collected prospectively antenatal steroid therapy did not reduce the incidence of RDS in multiple gestation white infants.

Betamethasone↗
PubMed1998

Determinants of preterm birth rates in Canada from 1981 through 1983 and from 1992 through 1994.

BACKGROUND: The rates of preterm birth have increased in many countries, including Canada, over the past 20 years. However, the factors underlying the increase are poorly understood. METHODS: We used data from the Statistics Canada live-birth and stillbirth data bases to determine the effects of changes in the frequency of multiple births, registration of births occurring very early in gestation, patterns of obstetrical intervention, and use of ultrasonographic dating of gestational age on the rates of preterm birth in Canada from 1981 through 1983 and from 1992 through 1994. All births in 9 of the 12 provinces and territories of Canada were included. Logistic-regression analysis and Poisson regression analysis were used to estimate changes between the two three-year periods, after adjustment for the above-mentioned determinants of the likelihood of preterm births. RESULTS: Preterm births increased from 6.3 percent of live births in 1981 through 1983 to 6.8 percent in 1992 through 1994, a relative increase of 9 percent (95 percent confidence interval, 7 to 10 percent). Among singleton births, preterm births increased by 5 percent (95 percent confidence interval, 3 to 6 percent). Multiple births increased from 1.9 percent to 2.1 percent of all live births; the rates of preterm birth among live births resulting from multiple gestations increased by 25 percent (95 percent confidence interval, 21 to 28 percent). Adjustment for the determinants of the likelihood of preterm birth reduced the increase in the rate of preterm birth to 3 percent among all live births and 1 percent among singleton births. CONCLUSIONS: The recent increase in preterm births in Canada is largely attributable to changes in the frequency of multiple births, obstetrical intervention, and the use of ultrasound-based estimates of gestational age.

Birth Rate↗
PubMed1998

International multicenter term PROM study: evaluation of predictors of neonatal infection in infants born to patients with premature rupture of membranes at term. Premature Rupture of the Membranes.

OBJECTIVE: Our objective was to determine significant predictors for the development of neonatal infection in infants born to patients with premature rupture of membranes at term. STUDY DESIGN: Multivariate analysis was used to determine the significant predictors of neonatal infection in infants born to women with premature rupture of the membranes who were enrolled in the Term PROM Study. In a randomized, controlled trial, the Term PROM Study recently compared induction of labor with expectant management for premature rupture of membranes at term. RESULTS: The following variables were identified as independent predictors of neonatal infection: clinical chorioamnionitis (odds ratio 5.89, P < .0001), positive maternal group B streptococcal status (vs negative or unknown, odds ratio 3.08, P < .0001), 7 to 8 vaginal digital examinations (vs 0 to 2, odds ratio 2.37, P = .04), 24 to < 48 hours from membrane rupture to active labor (vs < 12 hours, odds ratio 1.97, P = .02), > or = 48 hours from membrane rupture to active labor (vs < 12 hours, odds ratio 2.25, P = .01), and maternal antibiotics before delivery (odds ratio 1.63, P = .05). CONCLUSIONS: Among infants born to patients with premature rupture of membranes at term, clinical chorioamnionitis and maternal colonization with group B streptococci are the most important predictors of subsequent neonatal infection.

Adult↗
PubMed1998

Continuous ambulatory haemodynamic monitoring with an implantable system. The feasibility of a new technique.

AIMS: This study evaluates the feasibility and safety of a completely implantable system for long-term ambulatory monitoring of important haemodynamic parameters in patients with severe cardiopulmonary disease. METHODS: The design of the implantable monitoring system is similar to a conventional single lead pacemaker. A lead with incorporated biosensors for the continuous recording of pressure and oxygen saturation signals is positioned in the right ventricle and connected to a monitor and memory device subcutaneously implanted like an ordinary pacemaker can. RESULTS: Five patients with implanted haemodynamic monitoring systems have been followed for from 7 to 16 months. Continuous measurements of activity, heart rate, mixed venous oxygen saturation and estimated pulmonary artery diastolic pressure were registered with variable resolution during daily living and predefined provocations. The memory covered a maximum of 3 weeks at low resolution. The monitored parameters showed an adequate and significant response to various haemodynamic situations. Except for the demand of recalibration of two oxygen sensors, there were no technical problems and the quality of data were excellent. CONCLUSION: Long-term ambulatory haemodynamic monitoring is feasible and potentially useful for the management of patients with severe cardiopulmonary disease.

Activities of Daily Living↗
PubMed1998

Stability of sulphonamide drugs in meat during storage.

Incurred samples from a pig treated with sulphamethazine and spiked samples of the same concentration were compared during frozen storage. The contents of sulphamethazine in the different types of samples decreased similarly to about 50% after 15 months. When the samples were heat treated before analysis the sulphamethazine concentration did not change over time. Samples of bovine and porcine muscle were spiked with five different sulphonamide drugs and stored frozen for 3 months. Twenty-four hours at room temperature or 1 week at -20 degrees C did not affect the drug levels but after 1 month of frozen storage the levels in bovine and porcine muscle had decreased significantly. After 3 months the average decrease was 35% in bovine and 55% in porcine muscle.

Animals↗