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Biomedical subjects

A Wallin

Publications and source records attributed to A Wallin.

At least 109 records · Page 6Linked to original sources
PubMed1993

Concentration gradients for monoamine metabolites in lumbar cerebrospinal fluid.

Concentration gradients in lumbar cerebrospinal fluid (CSF) for the monoamine metabolites homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA) and 4-hydroxy-3-methoxyphenylglycol (HMPG) were studied in 9 healthy controls and 47 neuropsychiatric patients without diseases causing disturbed CSF circulation. In a serial sampling of the first 24 ml of CSF, steep concentration gradients between the first (0-4th ml) and last (21st-24th ml) portions of CSF were found for HVA (99 +/- 59% increase; p < 0.001) and 5-HIAA (88 +/- 54% increase; p < 0.001), while the concentration gradient was slight for HMPG (11 +/- 7% increase; p < 0.001). The existence of marked concentration gradients for the monoamine metabolites HVA and 5-HIAA gives further evidence for an active transport system for these metabolites and indicates that the lumbar CSF-HVA and 5-HIAA levels reflect the dopamine and serotonin metabolism in the brain. Moreover, the existence of pronounced concentration gradients for HVA and 5-HIAA stresses the importance of making analyses on a standardized volume of CSF.

Adolescent↗
PubMed1993

Interactive quantitative analysis of medical images on a PC- or workstation-based system.

Studies in clinical medicine often demand the quantitative analysis of digital CT and MRI cross-sectional images. In many instances, an important requirement is to perform the analysis on a stand-alone graphic workstation. This paper reports on a versatile image analysis software package which runs on several low-cost personal computers, as well as on high-end UNIX workstations. The software package contains basic display and analysis functions, including split-screen, zooming, and quantitative examination of pixels, density profiles, and regions of interest. It has been employed in a number of (foremost orthopaedic) studies.

Humans↗
PubMed1993

Cerebrospinal fluid monoamine metabolites in 114 healthy individuals 18-88 years of age.

Concentrations of the monoamine metabolites homovanillic acid (HVA), 5-hydroxy-indoleacetic acid (5-HIAA) and 4-hydroxy-3-methoxyphenylglycol (HMPG) were determined in lumbar cerebrospinal fluid (CSF) of 114 healthy individuals, 18-88 years of age, without histories, symptoms or signs of central nervous system dysfunction. The mean values (+/- SD) were 253 +/- 109 nmol/l for HVA, 125 +/- 54 nmol/l for 5-HIAA, 47 +/- 10 nmol/l for HMPG, and 2.10 +/- 0.52 for the HVA/5-HIAA ratio. Analyses of confounding factors revealed that all metabolites correlated negatively with body height, the values being lower in taller than in shorter individuals. This is probably attributable to a larger surface area for monoamine metabolite transport from the subarachnoid space in taller than in shorter individuals. These correlations make statistical adjustment for body height important in analyses of monoamine metabolite levels. Without considering body height, all monoamine metabolites showed a positive correlation with age, and higher levels of HVA and 5-HIAA were found in women than men. After statistical adjustment for the influence of body height, no differences in CSF monoamine metabolites levels were found between the sexes, and only 5-HIAA showed a positive correlation with age. There were no significant seasonal variations for any of the monoamine metabolites.

Adolescent↗
PubMed1993

Low blood pressure and blood glucose levels in Alzheimer's disease. Evidence for a hypometabolic disorder?

OBJECTIVE: To test possible differences between patients with Alzheimer's disease (AD) and patients with other forms of dementia and the healthy population concerning body composition, blood pressure, metabolic data and leukoaraiosis (LA). DESIGN: Retrospective study on data collected according to a predefined protocol. SETTING: A geriatric, neuropsychiatric diagnostic unit. SUBJECTS: Seventy-one consecutive patients with dementia. MAIN OUTCOME MEASURES: Body mass index, blood pressure, metabolism and LA in AD compared to other dementia forms. RESULTS: Mean blood pressure and fasting blood glucose levels were lower in patients with AD, 94 +/- 12 mmHg and 4.3 +/- 0.5 mmol l-1, compared to patients with unspecified dementia (NUD), 100 +/- 10 mmHg and 5.5 +/- 2.5 mmol l-1 (P < 0.05) and vascular dementia (VAD), 114 +/- 12 mmHg and 5.6 +/- 1.6 mmol l-1 (P < 0.001) and the age-matched healthy population. Body mass index, serum cholesterol and cortisol were similar in all groups of dementia patients whereas triglycerides were highest in the VAD group. No cases of diabetes or treatment for hypertension were found in the AD group while the prevalence was 21% and 36% for diabetes in the NUD and VAD groups and 8% in the population from the same region. There were 16% with antihypertensive treatment in dementia NUD, 50% in VAD, and 30% in the general population. Treated or newly detected hypothyreosis was present in 11% of the AD patients, none in the other dementia groups and 2% in the general population. Smoking was least common in AD. Degree of LA correlated with blood pressure and blood glucose levels. CONCLUSIONS: AD was clearly different to other dementia patients. They had lower blood pressure, blood glucose and higher prevalence of hypothyreosis than the healthy, age-matched population. These findings may indicate that AD could be a hypometabolic disorder.

Aged↗
PubMed1993

Low frequency of post-lumbar puncture headache in demented patients.

The frequency of post-lumbar puncture headache (PLPH) was registered prospectively in 395 consecutive demented patients at a dementia diagnostic unit. The incidence of PLPH was low, occurring in only 8 patients (2.0%), the severity was mild, and the duration was less than 2 days in all cases but one. The reasons for this low frequency of PLPH in patients with dementia disorders may include disease- and/or age-related low pain sensitivity, rigid dural fibres and arteriosclerotic vessels, and large CSF space due to cerebral atrophy. Analysis of CSF is essential to identify secondary causes of dementia, preferentially chronic infections. The low frequency and severity of PLPH found in the present study shows that, with low risk of complications, lumbar puncture can be included in the routine clinical examination of demented patients.

Adult↗
PubMed1993

Time course and duration of bronchodilatation with formoterol dry powder in patients with stable asthma.

BACKGROUND: Formoterol, a new beta 2 agonist, is long and fast acting when given as an aerosol. The aim was to determine the onset and duration of bronchodilatation with formoterol as a dry powder compared with salbutamol dry powder and with placebo. METHODS: Fifteen patients with stable asthma with a reversibility of 15% or more participated in a double blind, within patient study. On five different days the patients received formoterol 6 micrograms, 12 micrograms, or 24 micrograms, salbutamol 400 micrograms, or placebo in random order. Forced expiratory volume in one second (FEV1) was measured 10 minutes before, 30 minutes after, and then every hour for up to 12 hours after treatment. Specific airway resistance (sRaw) and specific airway conductance (sGaw) were measured immediately before and one, three, five, 10, 15, and 30 minutes after treatment. RESULTS: Formoterol 12 micrograms and 24 micrograms caused bronchodilatation as rapidly as salbutamol 400 micrograms. Peak values were not significantly different in the active treatments. The duration of action, calculated as median time with 20% or more of the maximum achieved increase in FEV1, was sustained for 9 hours and 16 minutes with salbutamol 400 micrograms, for 9 hours and 45 minutes with formoterol 6 micrograms, for 11 hours and 22 minutes with formoterol 12 micrograms, and for 11 hours and 42 minutes with formoterol 24 micrograms. CONCLUSIONS: Formoterol as a dry powder at doses of 12 micrograms and 24 micrograms produces a rapid onset of action and has a bronchodilator effect comparable with salbutamol 400 micrograms as a dry powder. The bronchodilatation was sustained for 11-12 hours. Formoterol 6 micrograms caused similar bronchodilatation but more slowly and for a shorter time.

Administration, Inhalation↗
PubMed1993

Quantitative MR imaging of lumbar intervertebral disks and vertebral bodies: influence of diurnal water content variations.

The influence of diurnal water content variation on T1 and T2 and relative proton density (Nr) in intervertebral disks and vertebral bodies was studied in 10 healthy adult volunteers. T1, T2, and Nr were calculated from a set of 20 images obtained at 1.5 T with five single-section, multiecho sequences at different repetition times. Volunteers were randomized into study (one measurement in the morning and one in the evening) and control (two consecutive measurements in the morning) groups. In the study group, evening mean T1 and Nr in intervertebral disks and in vertebral bodies were significantly (P < .001) less than measured in the morning. Mean T2 in vertebral bodies significantly (P < .05) increased between morning and evening measurements. Diurnal variations were significantly less pronounced in degenerative than in normal intervertebral disks. No significant changes occurred in the control group. Relaxation time and Nr measurements allow sufficiently accurate estimation of diurnal water content variation in cohorts of vertebral bodies and intervertebral disks.

Adolescent↗
PubMed1993

Protein analyses in cerebrospinal fluid. I. Influence of concentration gradients for proteins on cerebrospinal fluid/serum albumin ratio.

Concentration gradients in lumbar cerebrospinal fluid (CSF) for albumin and IgG were studied in 8 healthy individuals and 44 neuropsychiatric patients by serial sampling of 6 successive portions of CSF, each containing 4 ml, in all 24 ml. Significant and identical decreases between the first (0-4th ml) and the last (21st-24th ml) portions were found for CSF-albumin (21% decrease, p < 0.0001) and CSF-IgG (21% decrease, p < 0.0001). Therefore, the CSF/serum albumin ratio also showed a significant gradient with a 21% decrease (p < 0.0001), while no gradients were found to the IgG index. These results imply that analyses of proteins in the CSF should be performed on a standardized volume of CSF, preferably the first 12 ml, to allow comparisons of scientific results between various patient groups and controls and between different laboratories and to increase the validity of protein analyses in clinical practice.

Adolescent↗
PubMed1993

Protein analysis in cerebrospinal fluid. II. Reference values derived from healthy individuals 18-88 years of age.

Analyses of the cerebrospinal fluid (CSF) to determine the blood-CSF barrier function and to detect intrathecal IgG production are used in the diagnosis of neurological and psychiatric diseases. Therefore, accurate reference values for these parameters are of utmost importance. However, current reference values are based on 'reference groups' consisting of patients with psychiatric and/or neurological symptoms but without positive clinical findings and on groups of young students. The present study presents reference values for CSF proteins in a large sample (n = 105) of healthy individuals, with a large age-span (18-88 years of age). The parameter for the determination of the blood CSF barrier function, the CSF/serum (CSF/S) albumin ratio, was found to show an increasing variability in individuals over 45 years of age, suggesting a less stable blood-CSF barrier function than in younger individuals. The upper reference limit for the CSF/S albumin ratio was 6.8 for individuals under 45 years of age and 10.2 for individuals over 45 years of age. The IgG index, a dimensionless quotient for the determination of intrathecal IgG production, showed only a minor correlation with age and had an upper reference limit of 0.63.

Adolescent↗
PubMed1993

Protein analysis in cerebrospinal fluid. III. Relation to blood-cerebrospinal fluid barrier function for formulas for quantitative determination of intrathecal IgG production.

To examine the possible influence of the blood-CSF barrier function on mathematical formulas for estimating intrathecal IgG production (IgG index, Tourtellotte's formula [TOURT], Schuller and Sagar's formula [Schull], and Reiber and Felgenhauer's formula [IgG(loc)]), we analysed serum and CSF samples from 105 healthy individuals, aged 18-88 years, and 816 consecutive patients without oligoclonal IgG bands (OCBs) in the CSF, aged 18-91 years. In healthy individuals there was no significant correlation between the CSF/serum (S) albumin ratio (i.e. blood-CSF barrier function) and the IgG index, a dimensionless quotient for determining intrathecal IgG production, and only a small correlation (r = -0.08, p < 0.05) in patients without OCBs. However, significant dependence on the blood-CSF barrier function was found, in both healthy individuals and patients without OCBs, for the formulas determining intrathecal IgG production in milligrams (per litre CSF or per day), i.e. for TOURT, SCHULL and IgG(loc). Therefore, we propose a new formula for the quantitative determination of intrathecal IgG production in mg/l, the IGGPROD, which is calculated as: CSF-IgG -[(0.51 x CSF-Alb x S-IgG)/S-Alb]. IGGPROD is an empirical formula, based on findings in 105 healthy individuals 18-88 years of age, and does not depend on the blood CSF barrier function.

Adolescent↗
PubMed1993

Extra-articular augmentation for residual hip dysplasia. Radiological assessment after Chiari osteotomies and shelf procedures.

The Chiari osteotomy and various shelf procedures are used to augment the weight-bearing area in dysplastic acetabula. The new articular surface derives by metaplasia from the acetabular rim and joint capsule, and is therefore of poorer quality than congruous hyaline cartilage. We reviewed 32 patients after augmentation procedures, using conventional radiographs and three-dimensional reconstruction from CT scans. We showed that Chiari osteotomy and shelf procedures generally achieve less than complete cover, especially over the posterolateral quadrant of the femoral head. Our results suggest that alternative methods which reorientate the whole of the acetabulum are the treatment of choice. Augmentation procedures remain as a salvage option when reorientation is inappropriate or the original hyaline cartilage surface is absent, as in subluxed joints with a secondary acetabulum. Computerised assessment is recommended before operation to assess existing cover and the possible extent of provision of new cover.

Adolescent↗
PubMed1992

Sulfatide as a biochemical marker in cerebrospinal fluid of patients with vascular dementia.

The myelin-associated glycosphingolipid sulfatide in cerebrospinal fluid (CSF) was investigated in 20 patients with vascular dementia (VAD), 43 with Alzheimer's disease (AD) and 20 age-matched controls. The sulfatide concentration in the VAD group (307 +/- 118 nmol/l) was significantly (p less than 0.0001) higher than that in controls (145 +/- 86 nmol/l) and the AD group (178 +/- 79 nmol/l). Among the VAD patients, 8/20 had a significantly increased concentration of sulfatide (greater than mean + 2 S.D.), as compared with controls, while only 2/43 of the AD patients had a sulfatide concentration above this level. It is suggested that the elevated concentration of sulfatide in CSF from VAD patients reflects demyelination. Furthermore, sulfatide determinations, when combined with clinical findings, may be of diagnostic value, for discriminating between VAD and AD.

Aged↗
PubMed1992

Vitamin B12 in CSF: reduced CSF/serum B12 ratio in demented men.

Vitamin B12 concentrations were determined in serum and cerebrospinal fluid (CSF) of 32 controls and 102 patients with dementia. The dementias were classified as Alzheimer's disease (AD), senile dementia of Alzheimer type (SDAT) and multi-infarct dementia (MID). A substantial number of patients (n = 42) could not be assigned to any of these diagnostic groups, as their dementias were of non-AD/SDAT and non-MID types. They were instead assigned to a group called non ultra descriptum (NUD). CSF B12 correlated significantly with serum B12. There were no statistically significant differences in serum B12 levels between the groups. Although with considerable overlap, CSF B12 concentrations and CSF/serum B12 ratios were significantly lower in the NUD group than in the control group. The NUD group had significantly lower CSF/serum B12 ratios than the group of patients with AD/SDAT. There was significant male predominance in the group of demented patients that had low CSF/serum B12 ratios outside the bivariate reference region. CSF and serum B12 levels appear insufficient as measures of the true brain vitamin B12 status. It may be a more dynamic approach to use the CSF/serum B12 ratio as an indication of transport function across the blood brain barrier, and possibly also across the CSF brain cell barrier.

Aged↗
PubMed1992

Differences in cerebrospinal fluid gangliosides between "probable Alzheimer's disease" and normal aging.

The four major brain gangliosides, GM1, GD1a, GD1b, and GT1b, were determined in cerebrospinal fluid (CSF) of 43 patients with "probable Alzheimer's disease (AD)" and 40 healthy controls without psychiatric or neurological disorders. The total concentration of the four gangliosides did not differ significantly between "probable AD" group (116 +/- 58 nmol/L) and controls (92 +/- 31 nmol/L), but the proportion between the gangliosides was changed. In the "probable AD" group compared with the age-matched control group, there was an increase in both the GM1 (22.6 +/- 9.3% vs 12.6 +/- 4.1%; p < 0.0001) and GD1a (32.1 +/- 9.8% vs 23.3 +/- 5.7%; p < 0.0005) proportion, and a decrease in the GD1b (20.0 +/- 6.6% vs 23.8 +/- 6.0%; p < 0.05) and GT1b (25.3 +/- 7.9 vs 40.3 +/- 9.3%; p < 0.0001) proportion. The proportion of GM1 showed a positive correlation with age in the control group (r = 0.45; p < 0.01), but a negative correlation with age in the "probable AD" group (r = -0.37; p < 0.05). Thus, although the increase in proportion GM1 in the "probable AD" group was preferentially found in younger "probable AD" patients, it was not caused by age differences. While the pathogenetic mechanism for these changes in CSF-gangliosides in "probable AD" remains to be established, it may reflect the degeneration of nerve cells and synapses.

Adolescent↗
PubMed1992

Mechanism of the nephrogenic repair response. Studies on proliferation and vimentin expression after 35S-1,2-dichlorovinyl-L-cysteine nephrotoxicity in vivo and in cultured proximal tubule epithelial cells.

Studies were performed in vivo using 35S-(1,2-dichlorovinyl)-L-cysteine, a nephrotoxin that damages the S3 segment of the proximal tubule after metabolism to a reactive intermediate. Initiation of damage (35S covalent binding) was complete by 6 hour, and an early proliferative response was observed by 24 hour in the S2 or S3C segments. Necrosis in the S3M and increased blood urea nitrogen were maximal at 48 hours and were accompanied by an increase in proliferation of cells at the wound site. Regeneration was marked by the appearance of vimentin expressing cells that lacked brush border enzymes. The loss of differentiated character in the regenerative epithelium persisted after the proliferation (bromodeoxyuridine incorporation) had stopped; redifferentiation occurred between days 5 and 13. Much of the process was reproduced by culturing rat kidney proximal tubule epithelial cells in defined medium. As growth increased, the cells expressed vimentin and lost brush border marker enzymes. However, as the cells reached high density and stopped dividing there was an increase in brush border markers, as was seen in vivo. Vimentin expression did not decrease, however. The data support a mechanism for damage and nephrogenic repair composed of 1) interaction of the toxin with the target cells, 2) necrosis and exfoliation, 3) loss of differentiation and cell growth, 4) recovery of the damaged area and cessation of cell growth, and 5) differentiation of the quiescent cells. Nephrogenic repair may have similarities with the differentiation of the tubular epithelium during development.

Alkaline Phosphatase↗
PubMed1991

Gangliosides in cerebrospinal fluid in 'probable Alzheimer's disease'.

The concentrations of the four major brain gangliosides--GM1, GD1a, GD1b, and GT1b--were determined in cerebrospinal fluid from 43 patients with "probable Alzheimer's disease" and 19 healthy controls. Alzheimer's disease was divided into type I (with the memory disturbances and predominant cortical parietal symptoms that are characteristic of Alzheimer's disease) and type II (with general cognitive and mild confusional symptoms, with or without only mild parietal symptoms). The GM, concentration was significantly higher in patients with Alzheimer's disease type I than in those with Alzheimer's disease type II and age-matched controls, but did not differ significantly between patients with Alzheimer's type II and age-matched controls. As gangliosides are enriched in nerve cell membranes, preferentially in synapses, the findings suggest more severe degeneration of cortical nerve cells in patients with Alzheimer's disease type I than in those with Alzheimer's disease type II.

Aged↗
PubMed1991

Regulation of rat proximal tubule epithelial cell growth by fibroblast growth factors, insulin-like growth factor-1 and transforming growth factor-beta, and analysis of fibroblast growth factors in rat kidney.

Growth factors may play an important role in regulating the growth of the proximal tubule epithelium. To determine which growth factors could be involved, we have investigated the mitogenicity of various purified factors in rat kidney proximal tubule epithelial (RPTE) cells cultured in defined medium. Fibroblast growth factors, aFGF (acidic FGF) and bFGF (basic FGF), stimulate DNA synthesis in a dose-dependent manner, with ED50 values of 4.5 and 3.2 ng/ml, respectively; their effects are not additive. With cholera toxin in the medium, both aFGF and bFGF can replace insulin or epidermal growth factor (EGF) to attain the maximum level of cell growth, but they cannot replace cholera toxin. Cholera toxin specifically potentiates the effects of FGFs on DNA synthesis. At high cell density, both insulin and insulin-like growth factor 1 (IGF-1) induce DNA synthesis more effectively than EGF, FGFs and cholera toxin. The high concentration (0.2-1.0 microgram/ml) of insulin required for cell growth can be replaced by a low concentration of IGF-1 (10-20 ng/ml), indicating that insulin probably acts through a low affinity interaction with the IGF-1 receptor. Transforming growth factor-beta 1 (TGF-beta 1) inhibits DNA synthesis induced by individual factors and combinations of factors in a concentration-dependent manner. Northern blot analysis shows that mRNA for TGF-beta 1, IGF-1, and aFGF, but not bFGF are present in rat kidney. Western blot analysis and bioassay data confirmed that the majority of FGF-like protein in rat kidney is aFGF. The data suggest that in addition to EGF, IGFs, and TGF-beta, FGFs may also be important kidney-derived regulators of proximal tubule epithelial cell growth in vivo and in vitro.

Animals↗