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Biomedical subjects

A Lundin

Publications and source records attributed to A Lundin.

At least 55 records · Page 3Linked to original sources
PubMed1994

Dopamine D1 receptor number--a sensitive PET marker for early brain degeneration in Huntington's disease.

D1-dopamine receptor binding in the brain was determined by positron emission tomography (PET) in five patients with Huntington's disease, in one asymptomatic gene carrier and in five control subjects. [11C] SCH 23390 was used as the radioligand. Brain morphology was recorded by MRI. The patients who all had a mild to moderate functional impairment showed an almost 50% reduction of putamen volume as well as D1-dopamine receptor density as compared to the controls. The total D1-dopamine receptor number in the putamen was reduced by 75% in the patient group. A similar reduction was found for the caudate nucleus. The asymptomatic gene carrier had volume and density values in the lower range of the control subjects. In the frontal neocortex there also tended to be a reduced D1-dopamine receptor binding in the symptomatic patients. The results indicate that [11C] SCH 23390 binding in combination with MRI can be used as a sensitive marker for early brain degeneration in Huntington's disease. This marker may be useful to monitor the pathophysiological effect of the disease gene and also to follow therapeutic interventions aiming at preventing the degenerative process.

Adult↗
PubMed1994

Cognitive-behavioural treatment for workers with chronic spinal pain: a matched and controlled cohort study in Sweden.

An ambulatory multimodal cognitive-behavioural treatment programme (MMCBT) for Swedish workers with chronic spinal pain was formally evaluated. The design was a matched cohort study with three repeated measures done in two groups of 35 referred patients (one exposed to MMCBT and controls exposed to usual care). The MMCBT package includes standardised modules of physical treatment, cognitive-behavioural treatment, education of worker patients, and education of subjects' supervisors. The primary outcome variables assessed were absenteeism, disability, pain, and depression. Because of a change in Swedish sick leave compensation laws affecting records of absence during the study period, absenteeism could not be reliably measured among controls. The trend, however, suggested a reduction of absenteeism among the subjects in the MMCBT cohort. The findings for disability, pain, and depression all showed clinically important and significant beneficial changes (ANOVA for repeated measures: disability p = 0.05; pain p = 0.001; depression p = 0.01). The direction of the improvements and the size of effect were coherent and clinically plausible. The benefits were only among the women in the study. These comprised 74% of each group. Further research on larger sample sizes and in cohorts more representative of the whole country are needed to confirm these encouraging findings and to explore how the benefits might be extended to men.

Adult↗
PubMed1993

Comparison of a bioluminescence assay with differential staining cytotoxicity for cytostatic drug testing in vitro in human leukemic cells.

An ATP assay using bioluminescence was evaluated for its ability in determining the cytotoxic effect of antileukemic drugs. Leukemic cells from 32 patients with ANLL were used to compare the ATP assay with the differential staining cytotoxicity assay (DiSC). Cells were incubated with doxorubicin, daunorubicin, idarubicin, mitoxantrone and ara-C in conditions that were adapted to mimic the in vivo exposure of leukemic cells to cytostatic drugs. After incubation the cells were cultured in liquid medium for 4 days and then analyzed for ATP content using the firefly luciferase method in an automated procedure. The cytotoxic effect as measured by both methods correlated satisfactorily (r = 0.8). We conclude that the automated ATP assay can replace the more time consuming DiSC assay for in vitro drug testing in ANLL.

Adenosine Triphosphate↗
PubMed1993

Release of small amounts of free fatty acids from human adipocytes as determined by chemiluminescence.

A semiautomatic luminometric method for determination of small amounts of free fatty acids (FFA) released from human adipocytes in vitro is described. Bovine serum albumin (BSA) is used as acceptor of free fatty acids in the incubation medium of isolated fat cells. The assay involves pretreatment with the detergent sodium dodecyl sulfate (SDS) to liberate the free fatty acids from the bovine serum albumin before activation by acyl-CoA synthetase (ACS) (EC 6.2.1.3). This is followed by oxidation of the resulting thioesters by acyl-CoA oxidase (ACO). The H2O2 formed is subsequently measured in a horseradish peroxidase (HRP) (EC 1.11.1.7)-catalyzed luminol reaction. The assay is linear in the interval of 0.01-1 nmol in the cuvette corresponding to 2-200 microM in the sample, and 25 samples are automatically assayed in the luminometer within 75 min. FFA release could easily be studied in a small incubation volume (200 microliters) of very diluted (10(4) cells/ml) human adipocyte suspensions. Samples (25 microliters) containing 0.25% BSA from incubates of adipose tissue cells did not interfere with the standard curve. The analytical interference from different factors that could be used in studies of lipolysis was investigated. No interference was observed up to the following concentrations: 5 microM epinephrine, 5 microM norepinephrine, 80 microM isoproterenol, 1 mM insulin, 2.5 mM propranolol, 5 mM phentolamine, and 5 microM ascorbate. Results obtained with the present assay were highly correlated (r = 0.997) with those obtained by a 260-times less sensitive spectrophotometric kit method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1992

Topical retinoic acid treatment of photoaged skin: its effects on hyaluronan distribution in epidermis and on hyaluronan and retinoic acid in suction blister fluid.

Topical treatment with retinoic acid (tretinoin, vitamin A acid) has been reported to partly reverse signs of photodamage. To determine whether the histochemical distribution of hyaluronan (hyaluronic acid, HYA) in the epidermis and dermis and the amounts of HYA and retinoic acid in suction blister fluid were influenced by such topical treatment, 14 subjects healthy apart from moderate photodamage were instructed to treat the lateral forearm with 0.01-0.05% retinoic acid cream for 6 months. In a study of the short-term effects, another six subjects applied 0.05% retinoic acid cream for 2 weeks. After 6 months the thickness of the vital epidermis had increased by 23%. The HYA staining was based on a specific immunohistochemical method in which hyaluronan-binding protein is used. Before treatment HYA was seen as a meshwork around the cells in the upper half of the stratum spinosum. After 6 months of treatment this meshwork had increased in thickness by 31% compared with pretreatment specimens. The HYA staining was already intense in the papillary dermis before treatment and no difference was observed after 6 months' treatment. The mean concentration of HYA in blister fluid had increased significantly (43%) after 2 weeks of treatment whereas after 6 months there was no significant difference in this respect between the treated and untreated arm. The increase in the thickness of the epidermal HYA meshwork after 6 months and the blister fluid HYA after 2 weeks may indicate that HYA is involved in the epidermal change induced by topical retinoic acid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1992

Digital luminescence radiography using a chest phantom. Comparison between radiographs displayed on monitor and hard-copy.

Ninety-eight digital radiographs of a chest phantom with simulated tumors in the mediastinum and left lung and a pneumothorax-simulation in the right hemithorax were compared with the corresponding examinations saved on optical disk and viewed on a 1,000-line monitor. The examinations were reviewed by 7 radiologists with different experience, and receiver operating characteristic (ROC) curves were constructed. There was no significant difference between the hard-copy and the monitor results. A significant interobserver difference was seen only with the low attenuating 6 mm "tumor" and then only between the observer with the highest and the one with the lowest scores.

Humans↗
PubMed1991

Evaluation of the adenosine triphosphate test in the diagnosis of urinary tract infection.

Determination by bioluminescence of the bacterial adenosine triphosphate (ATP) level in urine was evaluated as a method for detection of bacteriuria in 1126 women with symptoms of UTI and 530 attending for follow-up. Conventional urine culture was used as reference method. The criterion for bacteriuria was growth of greater than or equal to 10(5) cfu/ml, giving a prevalence of 0.60. ATP levels of less than 10 nmol/l and greater than 50 mmol/l indicated abacteriuria and bacteruiria, respectively, whereas intermediate concentrations required culture if the nitrite test was negative. With this diagnostic strategy the sensitivity and specificity was 0.96 and 0.90 at the first visit and 0.90 and 0.98 at follow-up. With some methodological improvement the ATP test could be useful in medium-sized and small laboratories.

Adenosine Triphosphate↗
PubMed1991

Glucose determination in samples taken by microdialysis by peroxidase-catalyzed luminol chemiluminescence.

An automatic, luminometric assay of glucose in samples of the extracellular water space obtained by microdialysis is described. The assay involves oxidation by glucose oxidase (EC 1.1.3.4) and mutarotation of glucose by aldose mutarotase (EC 5.1.3.3.). The H2O2 formed is subsequently determined in a reaction catalyzed by horseradish peroxidase (EC 1.11.1.7) using luminol as electron donor. The assay is linear between 0.01 and 1 nmol in the cuvette. The detection limit, defined as 3 standard deviations of the reagent blank, was 0.008 mumol/liter in the cuvette. A complete oxidation of glucose is obtained within 4 min and 25 samples are automatically assayed within 75 min. Addition of microdialysate sample obtained from human adipose tissue in vivo did not interfere with the standard curves. Glucose added to microdialysate resulted in a complete recovery compared to a H2O2 standard. Analytical interference from different factors was investigated. No interference was observed up to the following concentrations: 5 mumol/liter epinephrine, 1 mumol/liter norepinephrine, 100 mumol/liter insulin, 500 mumol/liter pyruvate, 50 mmol/liter lactate, and 1 mumol/liter ascorbate. The glucose values with the present method correlated strongly (r = 0.984) with values obtained using a routine method involving glucose oxidase and peroxidase.

Adipose Tissue↗
PubMed1991

Histochemical localization of hyaluronan in psoriasis, allergic contact dermatitis and normal skin.

In suction blister fluid from active psoriatic lesions we have previously found elevated concentrations of hyaluronan. The aim of this investigation was to study the localization of hyaluronan with a histochemical method, in biopsy specimens from lesions of 13 patients with progressive psoriasis. Ten normal subjects and seven patients with allergic contact dermatitis were also studied. In normal epidermis the highest intensity of hyaluronan staining was found in the intercellular spaces in the middle and upper spinous layer, whereas the staining was much weaker in the basal layer. No hyaluronan was detected in the granular layer or in the orthokeratotic stratum corneum. In the dermis there was pronounced staining of the papillary dermis and around the sebaceous glands, sweat glands, hair follicles and blood vessels. In six of the 16 specimens from psoriatic lesions the normal epidermal meshwork of hyaluronan was partly absent and replaced by diffuse staining of both the spinous and the basal layer. In the remaining ten of these 16 specimens the same type of meshwork was found in stratum spinosum as in normal skin. The parakeratotic stratum corneum contained hyaluronan, in contrast to the normal stratum corneum, where no hyaluronan was present. The pattern of hyaluronan staining in the dermis of the psoriatic lesions did not differ from that in normal dermis. In the majority of the allergic patch test reactions the junction was less distinct than in normal skin between dermis and epidermis and the normal hyaluronan pattern of the basal layer was abolished and replaced by a diffuse staining throughout the layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Efficacy of inverted digital luminescence radiography in evaluating chest neoplasms.

Inverted (positive) digital chest radiographs of patients with lung tumors were compared with commonly used (negative) digital images, consisting of one simulated normal and one contrast enhanced image. The first part of the material consisted of 80 patients of whom 40 had tumors and 40 were normal. Five radiologists with different experience reviewed the examinations. From their answers, ROC curves were constructed. The second part of the material consisted of 100 chest phantom examinations with a simulated tumor in the mediastinum (45 examinations) and/or the left lung (46 examinations). In 31 exposures there was no abnormality. These were reviewed by 3 observers and performed as an ROC study as well. There was no statistical difference between the different types of images or between the observers in the 2 studies.

Adult↗
PubMed1991

Digital luminescence radiography in interstitial lung disease. A receiver operating characteristics (ROC) analysis.

The subtle changes often found in interstitial lung disease can be difficult to evaluate at conventional radiography. In order to define the information obtained with digital radiography, it is particularly important to find out to what extent interstitial lung disease can be observed with this technique. Ninety-one patients, 56 with interstitial lung disease and 35 with normal lungs, were examined both with a digital system and with conventional film-screen technique. The examinations were reviewed independently by 4 radiologists with different experience and receiver operating characteristics (ROC) curves were constructed. The 2 systems were equal in diagnostic performance with no statistic difference between the conventional radiographs, the 2 digital images reviewed together or the 2 digital images reviewed separately. There was a significant difference between the 2 observers with the highest and the one with the lowest score only in the review of digital unsharp mask images, but otherwise no differences statistically. A lower number of false negatives and a higher number of false positives were seen with the digital unsharp mask image, producing a higher sensitivity and lower specificity.

Adult↗
PubMed1990

A sensitive method for measuring ATP-formation in rat muscle mitochondria.

A sensitive method for the measurement of the ATP production rate in isolated skeletal muscle mitochondria is presented. Mitochondrial suspensions were prepared by differential centrifugation from approximately 80 mg of soleus muscle. ATP production rates were measured luminometrically, utilizing a reagent based upon firefly luciferase, which emits light proportional to the ATP concentration. In a group of 10 rats the ATP production rates were measured with the following substrate combinations: pyruvate + malate, palmitoyl-L-carnitine + malate, alpha-ketoglutarate, succinate + rotenone and succinate alone. The variance of the method including tissue preparation, protein determination and the luminometric determination of ATP production was estimated to be 10-14% for the various substrates. Compared to values in the literature, the present results show a good agreement for the substrates pyruvate + malate and palmitoyl-L-carnitine + malate, but lower rates were obtained in our study for alpha-ketoglutarate and succinate + rotenone. The advantage of the luminometric method is its high sensitivity. Only 30-40 mg of tissue is required for a complete determination, compared to 1-2 g for a similar assay of oxygen consumption. The method is intended for use in human subjects and will facilitate studies of mitochondrial respiration both in patients of different age groups and in healthy subjects.

Adenosine Triphosphate↗
PubMed1990

Efficacy of single-dose versus seven-day trimethoprim treatment of cystitis in women: a randomized double-blind study.

Single-dose trimethoprim treatment of cystitis was compared with 7-day treatment in a randomized double-blind study in primary health care. Consecutive female patients (613) with symptoms of lower urinary tract infection (UTI) and positive bacteriuria screening tests were enrolled. In 502 cases UTI was confirmed by urine culture. Follow-up was performed twice, after 2-3 and 5-6 weeks. Short-term efficacy could be evaluated in 425 cases and accumulated efficacy in 344. Short-term efficacy was 82% for single-dose and 94% for 7-day treatment (P less than .001). Accumulated efficacy was 71% for single-dose and 87% for 7-day therapy (P less than .001). Fewer adverse reactions were noted with single-dose therapy (not significant). The cure rate for UTI caused by P-fimbriated Escherichia coli was not different from that of other E. coli infections. Infections with Staphylococcus saprophyticus showed a lower cure rate than E. coli infections with the single-dose regimen (P less than .05 for short-term efficacy).

Adolescent↗
PubMed1990

The eosinophil granulocyte in psoriasis.

The presence of eosinophils and eosinophil cationic protein (ECP) in the involved and non-involved skin in patients with psoriasis was studied using a polyclonal antibody specific for ECP and a monoclonal antibody (EG2) specific for activated eosinophils and secreted ECP. ECP immunoreactive eosinophils were found in all the specimens from involved psoriatic skin. In new lesions in patients with rapidly progressive disease, intense ECP immunoreactivity was detected both intra- and extracellularly, particularly in the upper third of the epidermis and usually in association with granulocytes. In stable or slowly progressive lesions, less ECP was observed. The EG2-immunoreactivity was positive in the same areas. ECP was also determined in suction-blister fluid from lesional and non-involved skin in psoriasis patients and in healthy subjects. The ECP concentration was greatly elevated in the fluid from lesions in patients with more acute and progressive disease.

Adolescent↗
PubMed1990

Female urinary tract infection in primary health care: bacteriological and clinical characteristics.

Female patients with symptoms of urinary tract infection (n = 1136) were studied in primary health care with respect to (a) clinical symptoms as predictors of bacteriuria; (b) relation between aetiological agent and clinical picture, especially for P-fimbriated Escherichia coli; and (c) clinical findings in cases with 10(2)- less than 10(5) CFU/ml of E. coli. Prevalence of bacteriuria (greater than or equal to 10(5) CFU/ml) was 61%. Concurrence of urgency/frequency and dysuria, short duration of symptoms and hematuria increased the probability of bacteriuria and were also significantly more frequent among cases with low counts of E. coli (10(2) less than 10(5) CFU/ml in pure culture or mixed flora) than among cases with sterile urine, indicating an aetiological role of E. coli in many of those cases. Infections with P-fimbriated E. coli were as benign as the P-fimbriae-negative. The rate of P-fimbriation was 29% in specimens containing greater than or equal to 10(5) CFU/ml of E. coli, 30% among specimens with less than 10(5) CFU/ml in pure culture and 10% in specimens containing less than 10(5) CFU/ml of E. coli in mixed culture. Patients infected with Klebsiella, Enterobacter or Proteus did not show a higher rate of previous urinary tract disease or anomalies.

Adolescent↗
PubMed1990

Effects of UVB treatment on neutrophil function in psoriatic patients and healthy subjects.

To evaluate if whole body UVB irradiation has effects on the neutrophil function, eleven patients with mild to moderate psoriasis and 14 healthy subjects were treated with whole body UVB irradiation 3 times weekly for 4 weeks. Eight healthy untreated subjects served as controls. After 2 weeks of treatment the individual change of phagocytosis measured by the ingestion of IgG-coated particles was related to the pre-treatment value both in the psoriatic patients and healthy subjects (p less than 0.05 and p less than 0.001, respectively). Similar results were obtained for ingestion of IgG-C3b-coated particles. Thus, the change in phagocytic rate seemed to be dependent on the functional activity before treatment. UV irradiation of PMNs in vitro did not influence the phagocytic rate. After 4 weeks of UV treatment the healthy subjects showed a significant decrease in the rate of phagocytosis of IgG-C3b particles (p less than 0.02) and of the serum chemokinetic activity (p less than 0.01). In the psoriatic patients the mean chemokinetic activity in heated sera was decreased after 2 weeks (p less than 0.02). There appeared to be no relation between improvement of psoriasis and changes in PMN function. In an untreated group of healthy subjects no significant changes in neutrophil function were found. The results indicate that there is a change in PMN function during UVB treatment. The degree of change seems to vary, not only between individuals but possibly also between groups, e.g. healthy subjects compared with psoriatic patients.

Adult↗