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Biomedical subjects

S Berg

Publications and source records attributed to S Berg.

At least 73 records · Page 4Linked to original sources
PubMed1999

Color discrimination, color naming and color preferences in 80-year olds.

The aim of the present study was to investigate color discrimination, color naming and color preference in a random sample of 80-year-old men and women. Knowledge of color perception in old age can be of value when using color contrast, cues and codes in the environment to promote orientation and function. The color naming test indicated that the colors white, black, yellow, red, blue and green promoted recognition to the highest degree among all subjects. A gender-related difference, in favor of women, occurred in naming five of the mixed colors. Women also used more varied color names than men. Color discrimination was easier in the red and yellow area than in the blue and green area. This result correlates positively with visual function on far sight, and negatively with diagnosis of a cataract. The preference order for seven colors put blue, green and red at the top, and brown at the bottom, hence agreeing with earlier studies, and indicating that the preference order for colors remains relatively stable also in old age. This result should be considered when designing environments for old people.

Aged↗
PubMed1999

Colour discrimination, colour naming and colour preferences among individuals with Alzheimer's disease.

OBJECTIVE: To study the ability of colour naming, colour discrimination and colour preference in Alzheimer's disease (AD). DESIGN: Descriptive, consecutive sample. PARTICIPANTS: Fifty subjects >65 years with AD. INTERVENTIONS: Testing colour discrimination, colour naming and colour preferences. MAIN OUTCOME MEASURES: Ability to detect colour differences in the yellow, red, blue and green areas, ability to assign a name to 22 colour samples, ability to rank seven colours in order of preference. MAIN RESULTS: Discrimination ability was significantly better in the yellow and red area and for lightness variations. Cognitive decline had a significant impact on naming mixed colours and using elaborate colour names. Severity of dementia did not affect the preference rank order of colours. CONCLUSIONS: Ability to discriminate is affected in AD, with most errors in the blue and green area. Naming colours shows a cognitive decline. Preferences for colour are stable despite the disease.

Aged↗
PubMed1998

In-vivo three-dimensional ultrasound reconstructions of embryos and early fetuses.

BACKGROUND: Three-dimensional (3D) imaging of the living human embryo has become possible in the monitoring of embryological development, as described by classic human embryology. We aimed to create 3D images of organs in embryos on early pregnancy. METHODS: We used a specially developed 7.5 MHz annular array 3D transvaginal probe to examine embryos. We included 34 women at 7-10 weeks' gestation. We measured the crown-rump length (CRL) of the embryos and fetuses and transferred the 3D ultrasound data to an external computer for further processing to calculate volume. FINDINGS: The CRLs ranged from 9.3 mm to 39.0 mm. The quality of the images of the embryos and fetuses made it possible to outline in detail the outer contours and the contours of the brain cavities, and the calculated volumes corresponded well to the descriptions from classic human embryology. INTERPRETATION: Our 3D imaging system allowed visualisation of structures of less than 10 mm. Therefore, development and abnormal development of fetuses can be monitored.

Embryonic and Fetal Development↗
PubMed1998

Growth factor protection against cytokine-induced apoptosis in neonatal rat islets of Langerhans: role of Fas.

Treatment of neonatal rat islets of Langerhans with combined cytokines (interleukin-1beta 10(-10) M, tumour necrosis factor-alpha 10(-10) M, interferon-gamma 5 U/ml) led to extensive cell death, which was potentiated by Fas activation with the anti-Fas cytolytic antibody JO2. Pre-treatment with insulin (25 ng/ml) or insulin-like growth factor-1 (10(-8)M) gave only partial protection against cell killing, but prevented the Fas-mediated component. In the absence of cytokine treatment, Fas-mediated killing was not observed.

Animals↗
PubMed1998

[Genetic factors are often found inl Alzheimer disease. An extensive twin study to clarify the heredity-environment relationship].

Genetic and environmental risk factors are central concerns in dementia research. Through twin studies one can study the relative importance of genetic and environmental risk factors. One such study, based on the Swedish Twin Registry, shows that genetic effects are of considerable importance for developing Alzheimer's disease, even late in life, but that environmental factors are also important. For vascular dementia, the results indicate that non-genetic factors are of primary importance.

Aged↗
PubMed1998

(R)-(+)-2-[[[3-(Morpholinomethyl)-2H-chromen-8-yl]oxy]methyl] morpholine methanesulfonate: a new selective rat 5-hydroxytryptamine1B receptor antagonist.

In the search for new 5-hydroxytryptamine (5-HT) receptor antagonists it was found that the compound (R)-(+)-2-[[[3-(morpholinomethyl)-2H-chromen-8-yl]oxy] methyl] morpholine methanesulfonate, (R)-25, is a selective rat 5-hydroxytryptamine1B (r5-HT1B) receptor antagonist. The binding profile showed a 13-fold preference for r5-HT1B (Ki = 47 +/- 5 nM; n = 3) vs bovine 5-HT1B (Ki = 630 nM; n = 1) receptors. The compound had very low affinity for other monoaminergic receptors examined. The r5-HT1B receptor antagonism was demonstrated by the potentiation of the K+-stimulated release of [3H]-5-HT from superfused rat brain slices in vitro, an effect that was antagonized by addition of 5-HT to the superfusion fluid. (R)-25 at 20 mg/kg sc enhanced the 5-HT turnover in four rat brain regions (hypothalamus, hippocampus, striatum, and frontal cortex) with about 40% measured as the 5-HTP accumulation after decarboxylase inhibition with 3-hydroxybenzylhydrazine. At 3 mg/kg sc (R)-25 produced a significant increase in the number of wet dog shakes in rats, a 5-HT2A/5-HT2C response that was abolished by depletion of 5-HT after pretreatment with the tryptophan hydroxylase inhibitor p-chlorophenylalanine. These observations show that (R)-25, by inhibiting terminal r5-HT1B autoreceptors, increases the 5-HT turnover and the synaptic concentration of 5-HT.

Animals↗
PubMed1998

Effect of TGF-beta 1 on PDGF receptors expression in human scar fibroblasts.

This study examined the effect of exogenous TGF -beta1 on platelet derived growth factor alpha and beta (PDGF-alpha, beta) receptor expression in human dermal fibroblasts derived from both normal cutaneous tissues (normal skin [NSk]) and (normal scar [NSc]) and abnormal scar (keloid). TGF-beta and PDGF are present in the early phases of wound healing and are implicated in tissue fibrosis. In this study, replicate samples of NSk, NSc and keloid fibroblasts were grown to subconfluency in DMEM/10% FBS followed by replacement of media with DMEM/0.1%FBS for 24 hrs. One group of cells (NSk, NSc and keloid) were exposed to 10 ng/mL of exogenous TGF-beta1 for 24 hours, while the other group was used as control with no exposure to exogenous TGF-beta1. RadioImmunoBinding assays, Western and Northern blot analysis were performed to examine both PDGF-alpha and PDGF-beta receptor expression at the transcriptional and post-transcriptional levels. cDNA receptor probes were synthesized using polymerase chain reaction (PCR) with selected primer sets derived from published sequences. Beta-actin probe was used as a control to confirm that the same quantity of RNA was used for each experimental condition. TGF-beta1 was found to upregulate the expression of PDGF-alpha receptor for keloid fibroblasts but not for NSk or NSc fibroblasts. No effect was observed for TGF-beta 1 on PDGF-beta receptor expression for any of the cell lines examined.

Blotting, Northern↗
PubMed1998

Cognitive function in 70-year-old men and women. A 16-year cohort difference population study.

Cohort differences in cognitive functioning were studied in two 70-year-old samples born 16 years apart, 1906/07 and 1922, and living in Göteborg, Sweden. Psychometric tests measuring verbal ability, inductive reasoning, spatial ability, perceptual speed, secondary memory, and primary memory were used. All tests showed significantly better results in the latter 70-year-old cohort. Longer education and better living conditions in this cohort help to explain the results. Differences in somatic health could not explain the cognitive differences in this population. If biological age is defined as inversely related to the remainder of an individual's life span, the increasing life expectancy also means that the 70-year olds in 1992 are biologically younger than their 1976/77 counterparts.

Aged↗
PubMed1998

Antibodies to group B streptococci in neonates and infants.

UNLABELLED: Invasive group B streptococcal (GBS) infections are common in neonates but are rare after the 1st month of life. It is not known why GBS infections have this age distribution which differs from that of invasive infections caused by other encapsulated bacteria. The aim of this study was to test the possibility that serum antibodies against the GBS capsular polysaccharides (CPS) are acquired during the first months of life thereby preventing infections after the neonatal period. Cord sera were collected from 321 healthy term newborns. A second blood sample was collected at 2, 4, 8, 13 or 26 weeks of age. IgG CPS antibodies (measured by ELISA) against serotypes Ia, II and III were present in 98%-100% of all cord sera and decreased continuously during the first 6 months of life. No IgM antibodies against serotype III CPS were present in cord sera. Only 16%-17% of the children acquired IgM antibodies against serotype III CPS at 3 and 6 months of age. CONCLUSION: Early acquisition of IgG or IgM antibodies against CPS of the most common GBS serotypes was not demonstrated and cannot explain the rare occurrence of invasive GBS infections in children after the 1st month of life.

Age Factors↗
PubMed1998

A twin study of mortality after spousal bereavement.

BACKGROUND: Previous research has shown an increased risk of mortality after spousal bereavement, with the highest risk in the first weeks or months closest to the loss. One difficult issue in these designs is appropriate covariates and control groups. METHOD: This study is based on 1993 pairs of twins discordant for marital status and on 35860 married individuals from the Swedish Twin Registry born between 1886 and 1958 and followed for marital and vital status between 1981 and 1993. RESULTS: Spousal bereavement was a risk factor for mortality for both men and women using the still married co-twin as a control to the widowed proband, and controlling for earlier health status and health-related risk factors. The mortality risk was higher for young-old (under 70 years) individuals, and for recently widowed than for longer-term widowed. Young-old women had a pattern with increased mortality risk during the first years after bereavement, but also a markedly decreased risk if they survived 4 years after bereavement, as compared to married women. CONCLUSIONS: The results support a causal effect of bereavement on mortality. The decrease in risk for long-term young-old women is congruent with reports by widows of psychological growth after bereavement, involving increased sense of mastery and competence after learning to live in new sets of circumstances following the loss of their husband.

Adult↗
PubMed1998

Adult day care for dementia: a comparison of programs in Sweden and the United States.

Adult day care is regarded as an important respite service to family caregivers of dementia patients to assist the patient to remain in the community. This study includes 178 Swedish and 86 American day care centers serving cognitively impaired clients. Client, staff and organizational characteristics were surveyed. Although the two countries have quite different systems of elder care, client characteristics were similar, suggesting that adult day care centers are a convergent solution to a common problem of supporting disabled elderly. Differences were found between the USA and Sweden in the staff, structure, and services of the programs. The study raises questions about day care centers' goals and organization. Results provide a clearer understanding of the optimal role and function of adult day care centers.

Journal Article↗
PubMed1998

Impaired platelet function correlates with multi-organ dysfunction. A study of patients with sepsis.

Patients with sepsis often suffer from haemostatic disturbances such as haemorrhage and disseminated intravascular coagulation (DIC). Considering the pivotal role of platelets in haemostasis, we have investigated platelet function by flow cytometry in 16 patients with sepsis for a better understanding of their haemostatic function. We have also investigated whether platelet function correlates with the severity of disease assessed by multiple organ dysfunction (MOD) score and patient outcome. The platelet response ex vivo after stimulation with agonists, measured as platelet fibrinogen, binding was low in comparison with healthy volunteers ( n = 30). This could reflect a previous response to agonists in vivo , which lead to platelet activation and consumption and formation of microthrombi that could then participate in the development of M OD. The platelets that remain in the circulation might be the result of a selection process where the most active platelets have already been consumed, and the remaining population consists of less active platelets. Another explanation might be desensitization of the remaining platelets because of exposure to agonists in vivo . Platelet activation with the agonists ADP and arachidonic acid were predictive of subsequent development of MOD and final patient outcome.

Journal Article↗
PubMed1998

The effect of genetic factors for longevity: a comparison of identical and fraternal twins in the Swedish Twin Registry.

BACKGROUND: The relative importance of genetic influences on longevity was studied on data from the population-based Swedish Twin Registry. METHODS: A sample of 3,656 identical and 6,849 like-sexed fraternal twin pairs was studied regarding mortality rates and within-pair similarity for age at death. Genetic and environmental contributions to variation in longevity, expressed by integrated mortality rates, were estimated from a subsample of 1,734 twin pairs reared together and 130 twin pairs reared apart from the cohorts born 1886 to 1900. RESULTS: The intraclass correlation coefficients suggested that the genetic effect was small, and, for males, perhaps absent. Among pairs in which both twins died relatively young and among pairs in which both twins lived until very old age, the variance in age at death seemed to have no genetic component. Model fitting procedures based on twins reared apart and twins reared together indicated that most of the variance in longevity was explained by environmental factors. CONCLUSIONS: Over the total age range examined, a maximum of around one third of the variance in longevity is attributable to genetic factors, and almost all of the remaining variance is due to nonshared, individual specific environmental factors. The evidence that genetic factors play a minor role depending upon age at death merits further examination.

Adult↗
PubMed1998

Combined overdose with verapamil and atenolol: treatment with high doses of adrenergic agonists.

A 55-year-old man was admitted following an overdose of sustained-release verapamil (calcium channel blocker) and ordinary-release atenolol (beta-1 blocker). At admission, there was extreme bradycardia (20-25 beats min-1) and hypotension (systolic arterial pressure 40-50 mm Hg). To counteract the cardiovascular depression, prenalterol, dopamine, dobutamine, isoprenaline, adrenaline and noradrenaline were used. A satisfactory state was obtained with adrenaline, noradrenaline and dopamine infused at high rates. Cardiac output was then more than 101 min-1, with a very low total peripheral resistance. The infusion of the adrenergic agonists could be interrupted on day 3. Prolonged ventilator treatment was necessary but the patient recovered without sequelae. Treatment options for similar cases are outlined.

Adrenergic Agonists↗
PubMed1997

Purification of a phosphatase which hydrolyzes phosphatidic acid, a key intermediate in glucolipid synthesis in Acholeplasma laidlawii A membranes.

A phosphatidic acid phosphatase (PAP; EC 3.1.3.4.), dephosphorylating phosphatidic acid (PA) to diacylglycerol (DAG), was identified and purified from the plasma membrane of Acholeplasma laidlawii A. After four purification steps, including membrane preparation, Tween 20 solubilization, preparative gel electrophoresis and electro-elution, PAP was purified about 400 times to near homogeneity. The molecular weight of PAP was according to SDS-polyacrylamide gel electrophoresis approximately 25 kDa and the enzyme was a stable and integral membrane protein. It is proposed to catalyze the first enzymatic step in the important glucolipid pathway of A. laidlawii. No essential cofactors or activator lipids were found. However, some divalent cations and phosphate analogues were potent inhibitors. Beside the in vivo substrate (PA), PAP was found to dephosphorylate p-nitrophenylphosphate. This less stringent specificity makes alternative in vivo functions for PAP plausible, the importance which is discussed.

Acholeplasma laidlawii↗
PubMed1997

Diabetes and hypertension in rodent models.

As shown by ourselves and others, animals models closely resembling human complex diseases like IDDM in BB/OK and hypertension in SHR/Mol rats can be used to dissect a complex disease into discrete genetic factors as has been done for hypertension in (BB/OK x SHR/Mol) cross hybrids. Discrete genetic factors, so-called QTLs, were detected on chromosomes 1, 10, 18, 20, and X. To gain additional information about the physiologic effect of the mapped blood pressure QTLs, genetically defined regions of the SHR rat were transferred onto the genetic background of diabetes-prone BB/OK rats. Four new congenic BB.SHR rats named BB.Sa, BB.Bp2, BB.1K, and BB.Xs were generated and characterized telemetrically for blood pressure, heart rate, and motor activity. The data demonstrate clearly that each single blood pressure QTL of the SHR rat causes a significant increase of the systolic blood pressure and has a different influence on diastolic blood pressure, heart rate, and motor activity. The effects were modified differently by the diabetic state in BB.Sa, BB.Bp2, and BB.Xs rats carrying all diabetogenic genes of the BB/OK rats. The results demonstrate that these newly established congenic strains are a unique tool to study the physiological control of blood pressure by a single blood pressure QTL on the one hand and their interaction with hyperglycemia on the other. It is well within the bounds of possibility that diabetic congenics reflect the diabetic hypertension seen in diabetic patients. Because of the synteny conservation in gene order between different mammals, genes of the appropriate human region could therefore be candidate genes for hypertension in diabetics. Furthermore, these congenic strains can also be used to study interactions between a blood pressure QTL and various selected environmental conditions. In this way, one could learn which QTL can be influenced by environmental factors and to what extent. Another point is the study of gene interactions. Because congenics are genetically identical except for the defined transferred region, congenics can be crossed to investigate the interaction between two or three blood pressure QTLs selected by the investigator and not by nature. These QTL combinations can be studied in the nondiabetic as well as diabetic state. Although the advantage of congenic strains has been shown, the transferred chromosomal regions are too large to pinpoint the gene responsible for the phenotypic change. Therefore, regions on each chromosome must be systematically whittled down, which can be done by crossing the congenics with BB/OK rats and intercrossing their progeny to generate recombinants. These can then be used for the creation of new congenic lines carrying a much smaller region of the SHR/Mol rat. This has been started for the region on chromosome 1 spanning a 16-cM region from the Sa to the Igf2 gene. BB.Sa rats were therefore backcrossed onto BB/OK rats and the resulting progeny were intercrossed. The aim will be to create at least three new congenic BB.Sa rat strains homozygous for the SHR alleles of Sa, Lsn, or Igf2 genes. However, new problems will emerge with these new congenics. To genetically define small regions requires more dense polymorphic markers than are currently available. Dense polymorphic markers will also be necessary to split the other regions on chromosomes 10, 18, 20, and X. We expect that in the near future it will be possible using this approach to define small regions of < 0.5 cM. The recent progress in gene mapping in the rat gives hope that the use of such congenic lines will allow the identification and recovery of the blood pressure genes in the near future.

Animals↗
PubMed1997

Substantial genetic influence on cognitive abilities in twins 80 or more years old.

General and specific cognitive abilities were studied in intact Swedish same-sex twin pairs 80 or more years old for whom neither twin had major cognitive, sensory, or motor impairment. Resemblance for 110 identical twin pairs significantly exceeded resemblance for 130 fraternal same-sex twin pairs for all abilities. Maximum-likelihood model-fitting estimates of heritability were 62 percent for general cognitive ability, 55 percent for verbal ability, 32 percent for spatial ability, 62 percent for speed of processing, and 52 percent for memory. There was also evidence for the significant influence of idiosyncratic experience as the environmental component that most determines individual differences in cognitive abilities late in life.

Aged↗