PubMed Health⌕ Search

Biomedical subjects

S Berg

Publications and source records attributed to S Berg.

At least 37 records · Page 2Linked to original sources
PubMed2001

Health locus of control in late life: a study of genetic and environmental influences in twins aged 80 years and older.

The factor structure of health locus of control (Form A; K. A. Wallston, B. S. Wallston, & R. DeVellis, 1978) was examined in 420 octogenarians (M age = 83.2 years), and the contributions of genetic and environmental factors to health-control beliefs in 141 octogenarian twin pairs (71 identical, 70 same-sex fraternal) were estimated. Factor analyses reproduced previously proposed factors (Internal, Chance, and Powerful Others). Associations between health-control beliefs and life satisfaction, depression, and other health-related measures (e.g., self-rated health, outpatient contacts, and hospitalization), were modest. Quantitative genetic analyses revealed significant shared environmental influence on the Chance subscale, and significant familiality (attributable to a combination of genetic and shared environmental influences) on the Powerful Others subscale; there was no evidence of familiality on the Internal subscale.

Aged↗
PubMed2001

A randomized controlled trial oftransfusion-related acute lung injury: is plasma from multiparous blood donors dangerous?

BACKGROUND: Transfusion-related acute lung injury (TRALI) and other posttransfusion reactions may be caused by granulocyte and/or HLA antibodies, which are often present in blood from multiparous donors. The purpose of this study was to compare the effects of plasma from multiparous donors with those of plasma from donors with no history of transfusion or pregnancy (control plasma) in a prospective, randomized, double-blind, crossover study. STUDY DESIGN AND METHODS: Intensive care patients, judged to need at least 2 units of plasma, were randomly assigned to receive a unit of control plasma and, 4 hours later, a plasma unit from a multiparous donor (> or = 3 live births) or to receive the plasma units in opposite order. The patients were closely monitored, and body temperature, blood pressure, and heart rate were recorded. Blood samples for analysis of blood gases, TNFalpha, IL-1 receptor antagonist, soluble E selectin, and C3d complement factor were collected at least on four occasions (before and after the transfusion of each unit). RESULTS: Transfusion of plasma from multiparous donors was associated with significantly lower oxygen saturation and higher TNFalpha concentrations than transfusion of control plasma. The mean arterial pressure increased significantly after the transfusion of control plasma, whereas plasma from multiparous donors had no effect on it. Five posttransfusion reactions were observed in 100 patients, in four cases after the transfusion of plasma from multiparous donors. CONCLUSION: Plasma from multiparous blood donors may impair pulmonary function in intensive care unit patients.

Acute Disease↗
PubMed2001

Increased plasma hyaluronan in severe pre-eclampsia and eclampsia.

Pre-eclampsia is a serious multi-system disorder with general endothelial disease, often with a component of hepatic dysfunction. The pathogenesis of preeclampsia is not fully understood, and no specific diagnostic tests are available for early and reliable diagnosis, or for monitoring of the disease process. Hyaluronan is an extracellular matrix polysaccharide present at low concentrations in plasma. Normally, it is rapidly eliminated from the blood by the liver. Increased concentrations of circulating hyaluronan are seen in conditions with impaired hepatic function such as liver cirrhosis, and hyaluronan concentrations have previously been used to evaluate hepatic function in other diseases. In the present study, 11 pregnant women admitted to the intensive care unit with severe pre-eclampsia or eclampsia were studied. As control 31 healthy pregnant women, 18 undergoing vaginal delivery and 13 caesarean section, were included. Plasma hyaluronan was measured before and after delivery. Increased concentrations of plasma hyaluronan were found in the pre-eclampsia group both before (171 (75-586) microg/L (p<0.01)) and after delivery (215 (124-768) microg/L (p<0.001)) (median and inter-quartile range), as compared to both caesarean section (13 (7-28) microg/L before and 28 (18-48) microg/L after delivery) and vaginal delivery healthy controls (12 (8-24) microg/L before and 30 (13 63) microg/L after delivery). In the control groups, a small increase in plasma hyaluronan was seen after delivery, after both caesarean section (p<0.05) and vaginal delivery (p<0.01). In conclusion, plasma hyaluronan is increased in severe pre-eclampsia and eclampsia. The cause of the increase is unknown.

Adult↗
PubMed2001

Symptoms of depression in the oldest old: a longitudinal study.

This study examined depressive symptoms in a population-based, longitudinal sample of people aged 80 and older to determine initial prevalence of depressive symptoms and changes over time. Depressive symptomatology was assessed with the Center for Epidemiologic Studies-Depression scale (CES-D). The sample was drawn from the OCTO-Twin study, which examined 702 Swedish twins over age 80 in which both members of the pair were still surviving. For the present study, one member of each twin pair was randomly selected, resulting in a sample of 351. A comprehensive biobehavioral assessment was conducted at three time points over 4 years. Depressive symptoms were initially relatively low and decreased significantly between Wave 1 and Wave 2. At Wave 3, depressive symptoms increased slightly but not significantly. Participants who received a dementia diagnosis at some point in the study did not differ significantly on initial CES-D scores when compared to those participants who never received such a diagnosis. Lack of well-being, as opposed to negative affect, was the biggest contributor to the overall depression score at each of the three waves of measurement. Predictors of negative affect for this sample included activities of daily living, subjective health, and performance on the cognitive test, block design. None of these predictors were significant for lack of well-being.

Activities of Daily Living↗
PubMed2001

Education and the risk of Alzheimer's disease: findings from the study of dementia in Swedish twins.

The association between dementia and education was studied in 143 twin pairs discordant for dementia, using a matched-pair design, and in 221 dementia cases and 442 unrelated controls from the same twin registry, using a case-control design. Low education was defined as 6 years or less of schooling. Case-control analyses with prevalent cases showed low education to be a risk for Alzheimer's disease but not dementia in general. Low education did not significantly predict incident cases. In the matched-pairs analysis, which controls for genetic and other familial influences, differences in education between demented twins and twin partners were not statistically significant. However, for Alzheimer's disease, odds ratios resulting from matched pairs and case-control analyses were similar. Twins' comparative reports about intellectual involvement earlier in their lives suggest a long-standing difference on this dimension, with less involvement by the twin who became demented.

Aged↗
PubMed2001

Deficits in controlled processing may predict dementia: a twin study.

This study tested for differential patterns of cognitive decline in 33 twin pairs for which both were nondemented, but 1 member of the pair went on to develop dementia. Compared with their nondemented twin partners, twins who later developed dementia already showed poorer performance on tests of memory and attention, visuospatial-reasoning skills, and perceptual speed and the Mini-Mental State Examination (MMSE). The authors suggest that this cluster of tests reflects deficits in controlled rather than automatic cognitive processes. Nondemented twin partners of the twins who became demented were also compared with 33 matched controls selected from pairs in which both members remained nondemented. Nondemented twin partners scored lower than matched controls on tests of verbal ability, memory and attention, and perceptual speed and the MMSE. This finding indicates that nondemented twin partners of demented twins are at elevated risk themselves for becoming demented, and further suggests that certain areas of cognition are compromised prior to diagnosis of dementia.

Aged↗
PubMed2001

Treatment controversies in medulloblastoma.

Medulloblastoma, the most common primary malignant brain tumor in children, is a radiosensitive and chemosensitive tumor. Nevertheless, medulloblastoma remains a management challenge for the clinical oncologist, because the optimal sequence and dosage for each treatment modality has not yet been defined. In addition, effective management strategies for medulloblastoma may result in profound neuroendocrine and neuropsychologic sequelae. In this article, we review the clinical and biologic prognostic factors for classifying medulloblastoma, current strategies for the management of this disease, and potential strategies to prevent or minimize long-term treatment sequelae.

Cerebellar Neoplasms↗
PubMed2001

Increased incidence of a midline brain anomaly in patients with nonsyndromic clefts of the lip and/or palate.

BACKGROUND AND PURPOSE: Nonsyndromic clefts of the lip and palate (CLP) are developmental craniofacial abnormalities that are often associated with cognitive dysfunction. This study was designed to evaluate, in patients with CLP, the presence of a specific midline brain anomaly (enlarged cavum septi pellucidi [CSP]) that has been shown in other developmental syndromes to be related to poor cognitive function. METHODS: Brain images were obtained using magnetic resonance imaging on 49 adult men with CLP and 75 healthy controls. Size of CSP was measured using consecutive coronal images. RESULTS: The incidence of large CSP in the CLP group was 8% (4 of 49), significantly higher than that found in the control group. In 2 of these 4 subjects, the anomaly was complete nonfusion of the septal leaflets, known as a combined CSP and cavum vergae. Furthermore, there was a significant inverse relationship of IQ and CSP in CLP patients that was not present in controls. That is, in individuals with CLP, the larger the CSP, the lower the IQ. CONCLUSIONS: Adult men with CLP have an increased prevalence of enlarged CSP. Moreover, this anomaly is directly related to cognitive deficits. This study provides further evidence that the development of the face and the development of the brain are intimately related and that defects in craniofacial development are most likely associated with defects in brain development.

Adult↗
PubMed2001

Upper airway pressures in snorers and nonsnorers during wakefulness and sleep.

OBJECTIVE: To compare upper airway pressures in snorers and nonsnorers during sleep and wakefulness. DESIGN: Case series of snorers and nonsnoring controls. SETTING: Sleep clinic of a university hospital. METHODS: We used open catheters to measure differential nasopharyngeal and hypopharyngeal pressures in 8 nonapneic snorers with excessive daytime tiredness and 10 healthy nonsnoring controls. Measurements were performed during sleep (with the mouth taped to ensure exclusively nasal breathing) and wakefulness. When awake, the subjects were either seated (with the head neutral, flexed, extended, or rotated) or recumbent (dorsal and lateral positions). MAIN OUTCOME MEASURES: Comparison of pressures within the group as a function of body position and between the groups as a function of snoring. RESULTS: Differential nasal and pharyngeal pressures were similar in seated snorers and nonsnorers independently of head position. Assumption of recumbency resulted in significantly increased pharyngeal pressures in nonsnorers (26 +/- 18 Pa seated vs. 52 +/- 46 Pa recumbent, p < .05) and snorers (50 +/- 35 Pa seated vs. 93 +/- 38 recumbent, p < .01). The increase was higher in snorers than nonsnorers. During snoring, sleep differential pharyngeal pressures in snorers were markedly increased compared to quiet sleep (567 +/- 450 Pa during snoring epochs vs. 117 +/- 82 Pa during nonsnoring epochs, p < .01). CONCLUSIONS: Compared to nonsnorers, recumbent nonapneic snorers have elevated differential pharyngeal pressures indicative of increased upper airway resistance and reduced airway patency; this is present during wakefulness and sleep.

Adult↗
PubMed2000

Human immunodeficiency virus type 1 quasi species that rebound after discontinuation of highly active antiretroviral therapy are similar to the viral quasi species present before initiation of therapy.

In an effort to identify the sources of the viruses that emerge after discontinuation of therapy, analyses of human immunodeficiency virus (HIV) quasi species were done for 3 patients with sustained levels of HIV RNA of <50 copies/mL for 1-3 years. The sequences found in the rebounding plasma virus were closely related to those of the actively replicating form of viruses present before the initiation of combination therapy. All quasi species found in the rebounding plasma virus were also present in proviral DNA, cell-associated RNA in peripheral blood mononuclear cells (PBMC), and virion RNA derived from PBMC coculture during periods when plasma HIV RNA levels were <50 copies/mL. These findings suggest that the rapid resurgence of plasma viremia observed after discontinuation of therapy and the viruses cocultured from PBMC are derived from a relatively stable pool of the replicating form of virus rather than from activation of a previously latent pool.

Adult↗
PubMed2000

Ambipolar pentacene field-effect transistors and inverters.

Organic field-effect transistors based on pentacene single crystals, prepared with an amorphous aluminum oxide gate insulator, are capable of ambipolar operation and can be used for the preparation of complementary inverter circuits. The field-effect mobilities of carriers in these transistors increase from 2.7 and 1.7 square centimeters per volt per second at room temperature up to 1200 and 320 square centimeters per volt per second at low temperatures for hole and electron transport, respectively, following a power-law dependence. The possible simplification of the fabrication process of complementary logic circuits with these transistors, together with the high carrier mobilities, may be seen as another step toward applications of plastic electronics.

Journal Article↗
PubMed2000

Accuracy of in-vitro volume estimation of small structures using three-dimensional ultrasound.

We describe an ultrasound probe for three-dimensional transvaginal imaging. The transducer was an annular array with a center frequency of 7.5 MHz which was rotated with an internal stepper motor. The probe had no external moving parts, and the total volume covered by a full rotation defined a half sphere. The raw digital data from the scanner were transferred to an external PC for three-dimensional reconstruction. We evaluated the three-dimensional imaging system by measuring the volumes of phantoms (range 24.8-3362.5 mm(3)) in a water tank, and found good correlation with true volumes (two observers' measurements gave a linear regression with a slope of 1. 010 and R(2) = 0.993, and a slope of 0.956 and R(2) = 0.993, respectively). The size of the point-spread function was used in the calculations to eliminate the effect of under- or overestimation due to the limited ultrasound beam resolution. An example of data acquisition, volume estimation and imaging of an embryo less than 8 weeks old in vivo with the brain cavities and body is given. We conclude that the three-dimensional reconstruction and volume estimation were accurate and repeatable.

Embryo, Mammalian↗
PubMed2000

Volumetric blood flow measurement with the use of dynamic 3-dimensional ultrasound color flow imaging.

We describe a new method for measuring blood volume flow with the use of freehand dynamic 3-dimensional echocardiography. During 10 to 20 cardiac cycles, the ultrasonographic probe was slowly tilted while its spatial position was continuously recorded with a magnetic position sensor system. The ultrasonographic data were acquired in color flow imaging mode, and the separate raw digital tissue and Doppler data were transferred to an external personal computer for postprocessing. From each time step in the reconstructed 3-dimensional data, one cross-sectional slice was extracted with the measured and recorded velocity vector components perpendicular to the slice. The volume flow rate through these slices was found by integrating the velocity vector components, and was independent of the angle between the actual flow direction and the measured velocity vector. Allowing the extracted surface to move according to the movement of anatomic structures, an estimate of the flow through the cardiac valves was achieved. The temporal resolution was preserved in the 3-dimensional reconstruction, and with a frame rate of up to 104 frames/s, the reconstruction jitter artifacts were reduced. Examples of in vivo blood volume flow measurement are given, showing the possibilities of measuring the cardiac output and analyzing blood flow velocity profiles.

Aorta↗
PubMed2000

Serotypes and clinical manifestations of group B streptococcal infections in western Sweden.

OBJECTIVES: To study the serotype distributions of group B streptococci (GBS) isolated from blood and cerebrospinal fluid and from the genital tract of pregnant women and to investigate any possible relation between serotype, age and clinical manifestation. METHODS: Invasive strains were collected from 1988 to 1997 and genital strains from 1995 to 1996. Strains of GBS were serotyped with coagglutination. Clinical data were obtained from hospital notes. RESULTS: A total of 144 invasive strains, 78 from neonates and infants and 66 from adults, were serotyped. The most common isolates from neonates and infants were types III (62%), Ia (18%), and V (9%). The most common isolates from adults were types III (29%), Ib (23%), V (21%) and II (15%). A majority of the adults (94%) had an underlying medical condition. The most common serotypes of the 114 strains isolated from the genital tract of pregnant women were types III (32%), V (22%), Ia (13%), Ib (13%) and II (11%). CONCLUSIONS: Serotype III was the single most frequent GBS isolate from infants and adults. Serotype V, which appeared first in 1992, was the third most frequent isolate. A vaccine containing five GBS capsular polysaccharides appears to be appropriate for the Swedish population.

Adult↗
PubMed2000

Three-dimensional fetal ultrasound.

Three-dimensional (3D) imaging by ultrasound was proposed in the 1950s. Since the end of the 1980s, 3D ultrasound has become a major field of research in obstetrics and gynaecology. The technique of acquiring 3D data involves making a set of consecutive 2D ultrasound slices by moving the transducer and continuously storing the images. These ultrasound data must be converted into a regular cubic representation before presentation in different 3D visualization modes. The creation of new ultrasound sections from the 3D block and also the surface shading of a structure of interest promise improvement in the diagnosis of congenital anomalies and dysmorphology. In addition, the possibility of volume calculation by 3D ultrasound has to be considered as a clear innovation. At present, almost all of the diagnoses illustrated by 3D ultrasound can be made by 2D ultrasound, and this will continue to be so in the foreseeable future.

Echocardiography, Three-Dimensional↗