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Biomedical subjects

L Jacobsson

Publications and source records attributed to L Jacobsson.

261 records · Page 15Linked to original sources
PubMedDate not supplied

Tumour adjacent macrophage function in experimental tumours.

This study describes in vivo methodology for evaluating whole body and Tumour Adjacent Macrophage (TAM) phagocytic function in tumour-bearing rats. 29 Wistar rats were inoculated with 1 x 5 mm cylinders of syngeneic NGW-adenocarcinoma im in the right hind leg. 10 rats were given iv zymosan (3mg/100 g b.w.) for systemic activation of macrophages, 9 rats were given intratumour injection of zymosan (3mg/100g b.w.) for local activation and 10 rats were untreated controls. 10 days after tumour inoculation whole body phagocytic rate was estimated with dynamic liver RES scintigraphy. Tumour and blood radionuclide activity was measured. Dynamic liver RES scintigraphy measures whole body macrophage phagocytic rate (k) of iv 99Tcm Nanocoll albumin test colloid. TAM phagocytic rate is calculated from the final uptake in tumor/injected dose x k. Systemic macrophage activation caused a significant increase in liver and spleen weight and whole body phagocytic rate (0.65 +/- 0.02 versus 0.56 +/- 0.03% s-1). The TAM phagocytic rate was significantly elevated in tumors treated by local macrophage activation (0.003 +/- 0.00 versus 0.001 +/- 0.00% s-1). This study suggests that the TAM phagocytic rate is a sensitive indication of local macrophage activity.

Adenocarcinoma↗
PubMedDate not supplied

Renal function measured by x-ray fluorescence analysis. A comparison between contrast medium clearance and non-simultaneous 51Cr-EDTA clearance.

In twenty-six patients injected with metrizoate during urography, plasma was analyzed for iodine concentration using x-ray fluorescence analysis, and total plasma clearance of contrast medium was calculated. Total plasma clearance of 51Cr-EDTA was also determined, but not simultaneously, in order to find out if the urographic procedure would influence the kidneys to such an extent that the contrast medium clearance value would differ much from the 51Cr-EDTA clearance value. The errors in the method were assessed and the total error of the contrast medium clearance determination was calculated. When comparing 51Cr-EDTA and metrizoate clearance a correlation of 0.94 and a mean ratio of 1.046 (SD 0.138) was found. The assessable errors cannot fully explain the standard deviation, which might indicate a transient change in kidney function related to elements of the urographic procedure such as laxation with possible dehydration and/or the contrast medium dose.

Adult↗
PubMedDate not supplied

Glomerular filtration rate estimated after multiple injections of contrast medium during angiography.

In twenty-six patients referred for angiography, clearance of contrast medium was determined with x-ray fluorescence analysis after multiple injections of contrast medium. A formula for correction of the injected amount, which takes into consideration the different times of contrast medium injections, approximating the total injected amount into one injection, was used. A single injection clearance of 51Cr-EDTA was determined at the same time. The results showed a good correlation between the clearance of contrast medium after multiple injections and the 51Cr-EDTA clearance after a single injection (r = 0.945). The correlation between contrast medium clearance calculated without correction for the different injection times, and 51Cr-EDTA clearance was the same (r = 0.946), due to short angiography time and rather low clearance values in our patients. It is concluded that total plasma clearance of contrast medium can easily be estimated after multiple injections. In this way patients with a risk of developing post-angiographic renal failure can be found.

Adult↗
PubMedDate not supplied

RES-macrophage stimulation and liver tumour growth in rats; evaluation with dynamic liver RES scintigraphy.

Dynamic liver RES scintigraphy with Nanocoll (99Tcm albumin colloid - 50 nm diameter) assessing RES-macrophage phagocytic function was performed in 40 control, 73 RES-stimulated non-tumour-bearing and 59 tumour-bearing Wistar/FU rats in vivo. Tumour-bearing rats were inoculated with 10(6) x 1.0 cells of a syngeneic nitrosoguanidine-induced colonic carcinoma in the liver. Twenty-eight of these rats had been treated one day previously with Zymosan (3 mg x 100 g-1 i v) as a RES stimulant. The clearance/uptake rate (k) of Nanocoll was calculated from dynamic liver images by the slope in the plot 1n [1 - U(t)/U] versus t where t is time and U liver uptake. k-value in control animals was 0.45 +/- 0.01.10(-2) x s-1 Zymosan injection in non-tumour-bearing rats caused stati-stically significant higher clearance/uptake rate on day 1, through 8 after treatment compared to that of controls. On day 8 k-value was 0.64 +/- 0.04. In tumour-bearing rats the uptake rate (k) was on day 8 0.66 +/- 0.03, while in RES-stimulated tumour-bearing rats it was 0.64 +/- 0.03. Survival was 22 +/- 1 days in tumour bearing rats and 37 +/- 4 days in RES stimulated tumour-bearing rats. The average tumour volume after one week was 132 +/- 24 mm3 in non-stimulated rats and 20 +/- 5 mm3 in RES stimulated rats. There was a negative correlation between uptake rate and tumour volume and a positive correlation between uptake rate and survival on day 8 in non-stimulated tumour-bearing rats. Dynamic liver RES scintigraphy with small size 99Tcm albumin colloid (Nanocoll) can be used to measure RES phagocytic function and the effect of liver tumour growth on RES.

Adenocarcinoma↗
PubMedDate not supplied

Cardiac output determination during intravenous cardioangiography using x-ray fluorescence analysis.

Cardiac output was determined with an indicator dilution technique during digital venous angiography of the left ventricle in 11 patients. The contrast medium injected into the right atrium was used as indicator. During and after the injection of contrast medium one blood sample per second was obtained through a catheter placed in the descending aorta. The samples were analyzed for iodine content with x-ray fluorescence analysis and cardiac output determined ad modum Stewart-Hamilton. Thermodilution was used as a reference method. The results indicate that the indicator dilution method with the use of contrast medium might be used for calibration of videodensitometric methods for blood flow measurements.

Adult↗
PubMedDate not supplied

CD4+ T-lymphocytopenia without HIV infection: increased prevalence among patients with primary Sjögren's syndrome.

OBJECTIVE: Primary Sjögren's syndrome (1 degree SS) is an autoimmune disease, usually accompanied by manifest immune hyperactivity. In some cases the disease converts to malignant neoplasia. On the other hand, there are clinical similarities to HIV infection. Since the rare phenomenon of persistent depletion of CD4+ T-lymphocytes in peripheral blood without HIV infection was recently defined as idiopathic CD4+ T-lymphocytopenia (ICL), we have used the ICL criteria to investigate the prevalence of this phenomenon among 1 degree SS patients. METHODS: During the period 1988-94, 115 caucasian patients (10 males), mean age 57.8 (range 19-82) years, with 1 degree SS were prospectively studied. Lymphocyte subsets were investigated by means of monoclonal antibodies and flow cytometry. For the detection of HIV and HTLV antibodies, we used an enzyme immunoassay (for HIV-1 and HIV-2), Western blot techniques (HIV-1, HIV-2, HTLV-I and HTLV-II), and the polymerase chain reaction procedure (HIV-1, HTLV-I and HTLV-II). HIV antigens were tested for with the HIV-1 p-24 Ag test. RESULTS: Six patients with 1 degree SS fulfilled the criteria for ICL. While the clinical condition of 5 of those six patients remained stable, one patient developed malignant lymphoma three years after her disease was classified as a case of ICL. The prevalence of ICL among our 115 patients with 1 degree SS was 5.2%, which is significantly higher than the rates reported for any other patient or population group. We have estimated the relative risk of ICL in 1 degree SS patients to vary from 3.4 to 6,000 (P values of 0.0001-0.025). CONCLUSION: We suggest that subjects with ICL should be carefully examined for 1 degree SS and, if its presence is confirmed, that they should be followed with regard to the possible complications of this disease, including the development of malignant lymphoma.

Adult↗
PubMedDate not supplied

Sjögren's syndrome: terminology.

In spite of our continuously improved pathobiological understanding, there is still no consensus on terminology and disease criteria in Sjögren's syndrome (SS). This survey points out discrepencies in the current description of the syndrome, and argues for a new classification model. We suggest that the present nomenclatures for the global disease (Sjögren's disease) and disease subsets (primary and secondary SS) be retained until additional pathobiological insights give rise to new and descriptive terms. We do find evidence, however, to support a new terminology and classification of the main immunoinflammatory manifestations of primary SS. Accordingly, three "exocrine" and four "non-exocrine" subgroups of disease manifestations are here defined. The usefulness of the proposed model should be evaluated in clinical studies and in a debate engaging all of the medical specialities involved.

Autoimmune Diseases↗
PubMedDate not supplied

Effects of the alpha-particle emitter At-211 and low-dose-rate gamma-radiation on the human cell line Colo-205 as studied with a growth assay.

BACKGROUND: The aim of this study was to investigate the biological effect of the alpha-particle-emitting isotope astatine-211 on the human cell line Colo-205 and to compare it with that of low-dose-rate gamma-radiation. MATERIALS AND METHODS: Plastic (PMMA) rotating phantoms were constructed, allowing precise dosimetry on a cellular level for both types of radiation. Growth assays using 96-well plates were used to estimate apparent cell survival for the two types of radiation. From this, the relative biological effect (RBE) could be estimated. RESULTS: Irradiation of the cells with 211At resulted in an RBE of 25.1 +/- 6.7 at 37% survival, and 17.3 +/- 2.5 at 10% survival, when compared with low-dose-rate gamma-irradiation. The absorbed dose at 37% survival, 0.12 Gy, corresponds to 2.2 traversals of alpha-particles through the cell nuclei. For cells irradiated with gamma-radiation (1 and 2 Gy), an apparent cell survival above unity was observed up to 50 hours post-irradiation, indicating a possible radiation hormesis effect. CONCLUSIONS: The RBE of 211At found in this growth-assay study was significantly higher than previously presented values. The difference might be due to the use of low-dose-rate gamma-radiation as reference. The RBE presented here could prove valuable when evaluating 211At-labelled compounds for radiotherapy.

Alpha Particles↗