Pregnancy outcome in women with multiple sclerosis: results from a prospective nationwide study in Finland.

The majority of individuals obtaining the diagnosis of multiple sclerosis are women of childbearing age. They are naturally concerned as to how multiple sclerosis affects the course of pregnancy and the developing foetus. The objective of this study was to prospectively evaluate the incidence of pregnancy complications and delivery risks, and to follow the natural course of multiple sclerosis during and after pregnancy in a cohort of Finnish patients with multiple sclerosis. Sixty-one patients with multiple sclerosis who became pregnant during the years 2003-2005 were prospectively followed-up from early pregnancy until 6 months postpartum. Multiple sclerosis relapses, Expanded Disability Status Scale rates and obstetric details were recorded. The results were compared with the statistics obtained from Finnish Medical Birth Register from the year 2004. We found that patients with multiple sclerosis were no more likely to experience pregnancy complications than Finnish pregnant women generally, but they had a greater likelihood for a need of artificial insemination (4.9% vs. 0.9%; p = 0.0009). Subjects with multiple sclerosis were more likely to undergo assisted vaginal delivery than the at-large cohort (16.4% vs. 6.5%; p = 0.0017). We conclude that pregnancy does not seem to pose a woman with multiple sclerosis to a greater risk for pregnancy complications when compared with women in general. The potential need for instrumental delivery should, however, be taken into account when planning the delivery of a mother with multiple sclerosis.

Local inflammatory response in choriodecidua induced by Ureaplasma urealyticum.

Ureaplasma urealyticum is the bacterial species most often connected with preterm birth, although it often colonises the amniotic fluid without any adverse effects. The induction of preterm labour seems to depend on whether the bacteria produce an inflammatory reaction. In vitro stimulation of choriodecidual tissue with high amounts of U. urealyticum or with lipopolysaccharide induced a qualitatively similar inflammatory response detected by the production of tumour necrosis factor alpha, followed by secretion of anti-inflammatory cytokine interleukin-10 and of prostaglandin E2. Lower quantities of bacteria failed to induce any response.

Influence of film digitization on radiological interpretation.

Our objective was to evaluate the influence of changing from analogue to digital imaging on interobserver and intraobserver image interpretation. Three radiologists interpreted 96 three image series of occipitomental radiographs of paranasal sinuses from the films and from the corresponding digitized images from the screen. Images were classified according to degree of abnormality as either normal, with mucosal thickening of less than 5 mm, with mucosal thickening of 5 mm or more, total opacity, air-fluid level or polyp or cyst of maxillary sinuses. In the present study we found that there were more differences between two radiologist's interpretations with a single method than in a single radiologist's interpretations between the methods, although radiologists interpreted fewer pathological findings from the digitized images than from the corresponding films. Our data show that the results of image interpretation are preferentially dependent on the reader rather than on the method of reading.

High levels of dopamine activity in the basal ganglia of cigarette smokers.

OBJECTIVE: The authors' goal was to study presynaptic dopamine activity in smoking and nonsmoking human subjects in vivo. METHOD: [(18)F]Fluorodopa ([(18)F]DOPA) uptake K(i) values in the basal ganglia of nine smoking and 10 nonsmoking healthy men were measured with positron emission tomography. RESULTS: Significantly higher [(18)F]DOPA uptake was observed in both the putamen (average 17.3% higher) and the caudate (average 30.4% higher) of smokers than in those of nonsmokers. CONCLUSIONS: Smoking is related to greater dopamine activity in the human basal ganglia. Nicotine-induced dopamine activity may be a relevant mechanism in dependence on cigarette smoking.

Reduced brain creatine in gyrate atrophy of the choroid and retina with hyperornithinemia.

OBJECTIVE: To analyze in vivo brain creatine (Cr) content in gyrate atrophy of the choroid and retina with hyperornithinemia (GA). BACKGROUND: GA is caused by inherited deficiency of ornithine-delta-aminotransferase activity. Patients lose their vision by middle age and develop selective atrophy of type II skeletal muscle fibers. As demonstrated by MRS, the patients' skeletal muscles have diminished stores of high-energy Cr phosphate. Minor structural and electrophysiologic abnormalities in the brain of these patients also imply that the CNS may be affected. METHODS: The authors acquired proton MR spectra of the basal ganglia of 22 healthy control subjects and 20 GA patients. Nine patients received supplementary Cr or its precursors, and one child was on an arginine-restricted diet to normalize plasma ornithine concentration. The ratios of N-acetylaspartate (NAA) to Cr, NAA to choline (Cho), and Cho to Cr, and the ratios of NAA, Cho, and Cr to tissue water were calculated. RESULTS: NAA/Cr (Cho/Cr) in the untreated and treated patients and control subjects were (mean +/- SD) 3.3+/-0.4, 2.0+/-0.4, and 1.5+/-0.7 (1.9+/-0.3, 1.3+/-0.4, and 0.9+/-0.2), indicating that Cr content in untreated GA patients was proportionally and markedly diminished, and partially corrected by therapy (p < 0.0001). NAA/Cho was similar in all three groups. Cr/water in the untreated patients was only 46%, and increased to 75% of the control ratios in the treated patients (p < 0.0001). CONCLUSIONS: Hyperornithinemia-associated Cr deficiency in GA also affects the CNS, further supporting the possibility that Cr deficiency also has a pathogenetic role in the retina. The deficiency was partially corrected by Cr supplementation and an arginine-restricted diet.

A new ultrasonic technique for quantifying blood echogenicity.

The echogenicity of blood varies with the conditions of flow. This study introduces a new technique for quantifying blood echogenicity and includes digitalization of the signal from an A-mode ultrasound scanner, integration, subtraction, and computer analysis of the signal. Shear rate (directly proportional to velocity) had an inverse relationship to the blood echogenicity. Hemodilution with Ringer's solution and with low-molecular-weight dextran 1 decreased blood echogenicity, whereas the addition of a macromolecular protein (dextran 70) increased blood echogenicity. This technique makes possible a quantitative analysis of the factors affecting blood echogenicity.

Ultrasonic echoes registered from erythrocytes.

Erythrocytes at various concentrations were examined with a sensitive A-mode ultrasonic scanner; simultaneous measurements were made under light microscopic control. Individual erythrocytes caused weak (about 1 dB) echoes while erythrocyte aggregates (ten to 100 cells) produced stronger echoes (up to 15 dB), grossly proportional to the size of the aggregates. The latter type echoes were characteristic of higher erythrocyte concentrations (hematocrit 0.1 - 0.8). It is concluded that these echoes originate from red cell aggregates within the stagnant blood.

The effect of radiographic contrast media on ultrasonically detectable red blood cell aggregation in vitro.

We investigated the effect of radiographic contrast media (RCM) on red blood cell (RBC) aggregation by analyzing echogenicity of flowing blood before and after the addition of 2%, 20%, 50% or 95% volume of undiluted meglumine diatrizoate, iohexol, sodium meglumine ioxaglate, or iopamidol and equiosmolar volume concentration of saline. This was done both by stepwise increasing the concentration with minimal mixing and by stepwise decreasing the concentrations with more efficient mixing. All contrast media caused a drop in blood echogenicity after a proper mixing when compared with saline addition. After minimal stirring, both meglumine diatrozoate and iohexol caused a significant increase in blood echogenicity at volume concentrations over 50%. The paper demonstrates that earlier findings of both increased and decreased RBC aggregation following exposure to RCM can be reproduced and that the result depends on experimental setup. In diatrizoate and iohexol RBC aggregates disappear after mixing (increasing the shear rate) or when the RCM/blood mixture is diluted. After dispersement, the abnormal RBC aggregates will not reform.

The effects of the method of death and lapsed time on proton relaxation time T1 in autopsied muscle samples.

RATIONALE AND OBJECTIVES: The variation of measured magnetic resonance T1 relaxation times of autopsied human muscle samples is confusing. Hence, the authors studied rats' muscles to evaluate the effect of fiber type, the relative area of nonmyofiber space, fat and water content, cell death, and the mechanism of death on proton T1. METHODS: Rats were studied on a 0.1 T magnetic resonance device. We studied how death by cervical dislocation, pentobarbital injection, or a combination of these methods, as well as the amount of time lapsed after death, variably affected T1. RESULTS: Death itself did not affect T1, but the mechanism of death did: rats killed by cervical dislocation after ether anesthesia had longer T1 than those killed with an overdose of pentobarbital. T1 was significantly shorter 1 day after death than at 4 hours after and returned to baseline levels within 4 days after death. Repeated warming caused variation in T1 and obscured other possible changes. CONCLUSIONS: Investigation methods should be strictly controlled and standardized before measurements of the relaxation time, T1, of muscle tissue will provide consistent results.

Cell-mediated immunity in normal pregnancy and pre-eclampsia.

The in vitro responses of maternal lymphocytes to phytohaemagglutinin (PHA), concanavalin A (Con A) and purified protein derivative of tuberculin (PPD) were determined in uncomplicated and pre-eclamptic pregnancies and nongravid female controls. PHA, Con A and PPD responses were significantly lower in both pregnant groups compared to nongravid controls. No difference was observed in lymphocyte reactivity between women with pre-eclampsia or uncomplicated pregnancy. Both pregnant groups exhibited normal numbers of circulating T and B lymphocytes. The number of active E rosette-forming cells was significantly higher in peripheral blood of pre-eclamptic patients.

Circulating immune complexes in hypertensive disorders of pregnancy.

Circulating immune complexes (CICs) were measured in sera of pregnant women with pre-eclampsia and other hypertensive disorders of pregnancy and pregnant women with renal disease, using four different CIC assays: platelet 125I-labelled staphylococcal protein A test ( PIPA ), conglutinin-binding ELISA, C1q-binding ELISA and rheumatoid factor binding inhibition ELISA. CICs were shown to be present in the sera of 47% of women with severe pre-eclampsia, in 20% with mild pre-eclampsia and in 18% of women with normal pregnancy using the PIPA test. The PIPA test was capable of discriminating between patients with renal disease, which were all positive, and women with uncomplicated hypertension, which were all negative. All patients positive in the PIPA test, and most patients with a positive RFbI -ELISA test, had various amounts of proteinuria. Although half of the women with severe pre-eclampsia showed the presence of CICs in the PIPA test, the amount of these complexes was low and not constant in serial samples from the same patient.

Alpha-naphthyl acetate esterase activity in human foetal lymphocytes.

Human foetal mononuclear cells from thymus, spleen, liver, bone marrow and peripheral blood at 8-24 weeks of gestation were examined for cytochemical evidence of acid alpha-naphthyl acetate esterase (ANAE) activity. The focal brownish-red ANAE reaction product (T cell staining pattern) was observed in counterstained cytocentrifuged cell smears in the cytoplasm. ANAE-positive lymphoid cells were first observed in the thymus at 9 weeks of gestation. A gradual increase in frequency of ANAE-positive cells in foetal thymus was observed, from about 10% at 14-15 weeks to about 20% at 22-24 weeks of gestation. By 14 weeks of foetal age, spleen and liver contained a few ANAE-positive cells and after 15 weeks of gestation consistent occurrence of ANAE-positive cells was observed in foetal bone marrow and peripheral blood. These results demonstrate that ANAE-positive lymphocytes first appear in the foetal thymus and are subsequently found in the foetal liver, spleen, bone marrow and peripheral blood.

Deficient natural killer cell function in preeclampsia.

Natural killer cell activity of peripheral blood lymphocytes was measured against K-562 target cells with a 4-hour 51Cr release assay in 15 primigravid women with preeclamptic symptoms. Nineteen primigravid women with an uncomplicated pregnancy and 18 nonpregnant women served as controls. The natural killer cell activity of preeclamptic women was observed to be significantly lower than that of both control groups. Natural killer cells in preeclamptic women responded normally to augmentation caused by interferon. These findings give further evidence for the participation of the maternal immune system in this pregnancy disorder.

Diurnal fluid changes of lumbar discs measured indirectly by magnetic resonance imaging.

The feasibility of magnetic resonance imaging and the magnetization transfer technique for measurement of diurnal fluid changes in lumbar discs was studied with the use of 13 healthy subjects. The diurnal height loss of the subjects ranged from 13 to 21 mm. The disc signal in T2-weighted magnetic resonance imaging increased as much as 25% after overnight bed rest, presumably due to the enhanced influx of water. The change in magnetization transfer parameters also suggested increased hydration of the disc after bed rest. Magnetic resonance imaging techniques can be used for indirect measurement of the changes in fluid content and the interaction of water with macromolecules in the disc.

Determination of fat content of burbot (Lota lota) liver with low field MR imaging (0.04 T).

A reconstructed separate fat image was used for studying the fat content of the liver of 12 dead and six living fasting burbots (Lota lota) in a 0.04 T magnetic field with olive oil as a reference. The correlation between the MR intensities and the results of the cytological, histological and chemical fat measurements, as well as chemically measured water, collagen and total protein contents were examined. The MR signal intensity in reconstructed fat images correlated well with the changes in fat content of the liver in living fish (r = 0.69, P = 0.0014). Also the contents of water (r = -0.66, P = 0.003) and total protein (r = -0.91, P = 0.013) correlated significantly with the MR signal intensity. The reconstructed fat image is thus a reliable method for following the changes in tissue fat content. The living burbot is an applicable test animal for studying the hepatic fat content with MR.

Preoperative tissue characterization with chemical shift imaging: a case report of an epidermal cyst.

We introduce here a case of an epidermal cyst, which was preoperatively examined with chemical shift MR imaging at 0.1-T magnetic field. The case shows that fat/water separation method can be successfully used in tissue characterization.

Effect of fasting and food intake on magnetization transfer of human liver tissue.

Magnetization transfer (MT) technique is a promising method in differential diagnosis of diseases in parenchymal tissues. Basic knowledge about circumstances and elementary factors that influence MT and its parameters is still insufficient, however. Having a meal before the magnetic resonance (MR) examination could change liver MT parameters compared to fasting state through alteration in liver perfusion, blood flow, and content of portal blood (proteins and other derivates from a meal). If MT parameters can be altered by a meal, then MR liver studies should always be performed after fasting. Before MRI examinations we examined three healthy volunteers after a high-fat meal with Doppler ultrasound technique to find out duration and magnitude of changes in portal blood flow. Duration of > or = 50% increased peak-flow value compared to fasting state in portal vein was > 90 min, which is enough for our MR examination. With a low-field 0.1-T MR imager we examined 10 healthy volunteers after a short (range from 3 h 45 min to 17 h 30 min) fast and also immediately after a high-fat meal. Magnetization transfer parameters, magnetization transfer ratio (MTR) and magnetization transfer rate Rwm of liver tissue were determined. MTR changed significantly (Student paired two-tailed t-test, p = .0044) after a meal, but Rwm did not (p = .0952). We recommend a 4 h fast before MR examination that aims to determine the MTR of liver tissue.

Low field T1rho imaging of myositis.

The purpose of this study was to evaluate 1/T1rho in relation to 1/T1 and 1/T2 in characterizing normal and diseased muscle. We measured the muscle relaxation rates 1/T1 and 1/T2 at 0.1 T and 1/T1rho at on-resonance locking fields B1 between 10 and 160 microT in myositis patients and normal volunteers. 1/T2 and 1/T1rho of muscle were lower in the patients than in the volunteers, whereas there was no difference in the 1/T1 values. The lower relaxation rates 1/T2 and 1/T1rho in the diseased muscle may be due to fat and connective tissue infiltrations and edema. 1/T1rho contrast between muscle and subcutaneous fat was higher than 1/T2 and 1/T1 contrast. This may be explained by the different B1 dispersion behavior of these two tissue types. 1/T1rho of fat is B1 field independent, whereas 1/T1rho of muscle decreases clearly with increasing B1 field. In conclusion, 1/T1rho provides a useful tool in manipulating contrast in magnetic resonance imaging of diseased muscle.

Tissue characterization by image processing subtraction: windowing of specific T1 values.

A method for windowing specific T1 values is presented. A 1.0 T imager with two routine pulse sequences was employed: A T1-weighted spin echo (SE) sequence and a short tau inversion recovery STIR sequence (fat-suppressed IR). A T1 window for fat was obtained by subtracting the STIR image from the SE image. Negative values were coded black. The method was tested on a normal human thigh, on a human liver with confirmed fatty infiltration, and on the livers of four live burbots. The fat-containing tissues of the two human volunteers were well depicted. The differences in fat concentration among the burbot livers were also clearly shown. The fat intensity seen in the images correlated well with the chemically measured fat concentration. This subtraction method for windowing T1 values proved feasible for fat. The method could be used for tissues with other short T1 values as well.

Validity of ultrasonography in diagnosis of acute maxillary sinusitis.

BACKGROUND: Accurate diagnosis of maxillary sinusitis is difficult on the basis of clinical examination only because the signs and symptoms of sinusitis are nonspecific. A simple, rapid, and readily available method for diagnosing maxillary sinusitis in primary care would increase the accuracy of the diagnoses and thus reduce unnecessary antibiotic treatment. OBJECTIVE: To investigate the validity of ultrasonography compared with radiography and magnetic resonance imaging (MRI) in detection of maxillary sinusitis. DESIGN: Ultrasonography and plain-film radiography of the paranasal sinuses were performed on all patients and MRI was performed on 40 randomly selected patients on day 7 of the study. SETTING: Study office at the Department of Pediatrics of Turku University Hospital, Turku, Finland. PATIENTS: One hundred ninety-seven young adults who contacted the study office within 48 hours of the onset of symptoms of the common cold. MAIN OUTCOME MEASURES: Detection rates of maxillary sinusitis by ultrasonography, radiography, and MRI. RESULTS: Acute maxillary sinusitis was diagnosed in 24% of the sinuses by radiography and in 28% by MRI. Compared with MRI findings, the sensitivity of ultrasonography for detection of maxillary sinusitis was 64% (specificity, 95%). Using a 2-step diagnostic approach in which radiological findings were additionally considered in cases of negative ultrasound findings, a sensitivity of 86% (specificity, 95%) was observed. CONCLUSIONS: The high specificity of ultrasonography indicates that a positive ultrasound finding can be regarded as evidence of maxillary sinusitis. The addition of plain-film radiography in cases of negative ultrasound findings increases the diagnostic sensitivity to clinically acceptable levels without loss in specificity. Active use of ultrasonography would substantially decrease the need for radiological imaging of the sinuses and also help reduce unnecessary antibiotic treatment in primary care. Arch Otolaryngol Head Neck Surg. 2000;126:1482-1486