Biomedical subjects

J L Ericsson

Publications and source records attributed to J L Ericsson.

At least 37 records · Page 2Linked to original sources

PubMed1987

Biodegradable microspheres. V: Stimulation of macrophages with microparticles made of various polysaccharides.

The interaction between four different microparticulate drug carriers and macrophages was investigated in vitro. The microparticles, consisting of crosslinked starch (1,4-alpha-D-glucan with 1,6-alpha-branches), dextran (1,6-alpha-D-glucan with 1,3-alpha-branches), lichenan (1,3-beta-D-glucan), or mannan (1,6-alpha-D-mannan with 1,2-alpha- and 1,3-alpha-branches), were investigated for their macrophage stimulatory properties. Macrophage stimulation was assayed by the uptake of [14C]glucosamine and stimulatory indices were calculated. Microparticles made of crosslinked lichenan were most stimulatory, followed by the biologically inert mannan and dextran microparticles. Biodegradable starch microparticles were less stimulatory to the macrophages than the other microparticles. All microparticles were phagocytosed to the same extent and stimulated the macrophages to release oxygen radicals. Lichenan, mannan, and dextran microparticles induced morphological changes in the macrophages when given in nontoxic doses. No morphological changes were observed when the macrophages were exposed to starch microparticles or soluble polysaccharides.

Animals↗

PubMed1987

Macrophage stimulation with some structurally related polysaccharides.

The macrophage-stimulating properties of some structurally related polysaccharides were studied in vitro. When the polysaccharides were presented to the macrophages in a sterically fixed form, i.e. as microparticles, they induced the release of interleukin 1 (IL-1) from the macrophages. Microparticulate 1.3-beta-glucan (curdlan) induced nonspecific macrophage mediated tumour cell killing while 1.4-alpha-glucan (starch), 1.6-alpha-glucan (dextran), and 1.6-alpha-mannan were without effect. The corresponding soluble polysaccharides did not stimulate the macrophages. Kinetic studies showed that although IL-1 was released immediately after stimulation, the macrophages needed a time lag of several days to develop tumour cytotoxicity. The development of cytotoxicity paralleled binding of tumour cells to the macrophages. Resident and inflammatory peritoneal macrophages showed differences in their responses to the polysaccharides. Stationary, resident peritoneal macrophages stimulated by macroparticles secreted high levels of IL-1 but expressed a low cytotoxic activity, while newly recruited inflammatory macrophages released lower levels of IL-1 but readily killed the tumour cells. The influence of cyclo-oxygenase products on the IL-1 release and macrophage cytotoxicity was also investigated. When cyclo-oxygenase was blocked with indomethacin, a significantly higher release of IL-1, and then an increased cytotoxicity, were obtained with 1.3-beta-glucan stimulated macrophages. The results suggest that microparticulate polysaccharides may be useful for studies on the induction of macrophage differentiation and also for studies on nonspecific cellular immune responses in vitro and in vivo.

Animals↗

PubMed1987

Occupational risks for renal cancer in Sweden.

A systematic assessment was made of the occurrence of renal cancer among men by industrial and occupational classification using the Cancer-Environment Registry, which links cancer incidence (1961-79) and census data (1960) with industry and occupation for all employed individuals in Sweden. Data were analysed separately for cancers of the renal parenchyma and pelvis. Significantly increased risks for renal cell cancer were observed for several professional and white collar occupations, including physicians and others in the health care industry. By contrast, the risks for renal pelvis cancer tended to be higher among blue collar workers, especially in the machine industry. Deficits of both cancers occurred among farmers. The findings of the survey are considered as aetiological clues that may deserve further study, although some associations support observations in other countries.

Carcinoma, Renal Cell↗

PubMed1987

Peritoneal mesothelioma in the construction industry in Sweden.

As a follow-up to a recent examination of occupation and pleural mesothelioma in Sweden, we evaluated peritoneal mesothelioma using the Swedish Cancer-Environment Registry. There were 35 microscopically confirmed cases of peritoneal mesothelioma among employed men during the period 1961 to 1979. Almost 40% of cases were in the construction industry, with insulation workers at especially high risk (standardized incidence ratio = 163.9, 4 cases, P less than .001). Other groups such as textile and paper and pulp workers and painters showed nonsignificant increases in risk. These findings are consistent with previous studies in their countries, and demonstrate the usefulness of registry epidemiology in assessing occupational relationships to cancer.

Construction Materials↗

PubMed1987

Occupational risks for intracranial gliomas in Sweden.

With the use of the Cancer-Environment Registry, which links cancer incidence for the years 1961-79 with 1960 census information on occupation for all employed individuals in Sweden, a systematic population-based assessment according to employment classifications was made of the occurrence of intracranial gliomas. Statistically significant (P less than .05) increases in the incidence of intracranial gliomas were observed among several professional and white-collar occupations, possibly due in part to higher levels of diagnosis and reporting of this particular neoplasm. Significantly elevated rates were noted among male dentists, agricultural research workers, and public prosecutors and among female physicians and employees in the health care industry. For blue-collar workers, significant excesses were found among welders and metal cutters; glass, porcelain, or ceramic workers; cellulose plant employees; brick and tile workers; and women employed in the wool industry. Several findings of this survey may represent new clues to the etiology of intracranial gliomas, while other findings support observations reported in previous studies.

Brain Neoplasms↗

PubMed1987

Occupational risks for meningiomas of the CNS in Sweden.

Using the Cancer-Environment Registry of Sweden, which links cancer incidence (1961 to 1979) with census information (1960) for all employed individuals in Sweden, a systematic, population-based assessment was made of the occurrence of meningiomas of the CNS according to industrial and occupational classifications. Statistically significant standardized incidence ratios (SIR) between 5 and 6 for meningioma were observed among glass, porcelain, or ceramic workers of both sexes. SIRs of similar magnitude were also found for men employed in the headwear fabrication and book publishing industries. Significantly elevated two- to three-fold risks were observed for men employed in health care, railroad and trolley construction, sheet and plate metal fabrication, and as moving equipment operators. Some of the findings of this descriptive survey may have arisen as a result of multiple comparisons, but several are consistent with earlier observations for brain cancer from other countries and deserve further study.

Central Nervous System Diseases↗

PubMed1986

Biliary tract cancer and occupation in Sweden.

Using the Cancer-Environment Registry, which links the incidence of cancer (1961-79) and the 1960 census data on industry and occupation for all employed individuals in Sweden, the occurrence of biliary tract cancer (ICD 7th rev 155.1-.9) was systematically assessed according to occupational and industrial classifications. Data are presented separately for cancer of the gall bladder (ICD 155.1) and other cancers of the biliary tract (ICD 155.2-.9) including cancers of the extrahepatic bile ducts, ampulla of Vater, and unspecified bile passages. Statistically significant increased risks for cancer of the gall bladder were observed for men employed in petroleum refining, papermills, chemical processing, shoemaking, and repairing, and for both men and women employed in textile work. A significant increase in the incidence of other cancers of the biliary tract (mostly cancers of the bile duct) was found for such asbestos related employment as shipbuilding and in the wholesale construction materials industry and among insulation workers. These findings should be considered only as clues to aetiological factors, although several are consistent with earlier observations from other countries.

Biliary Tract Neoplasms↗

PubMed1986

Ultrastructural localization of serotonin and polypeptide YY (PYY) in endocrine cells of the human rectum.

This study was performed with the aim of ultrastructurally localizing serotonin and polypeptide YY (PYY) in the endocrine cells of the human rectum. Existing basic methods for immunolocalization of antigenic sites in ultrathin sections were tested and modified to allow reproducible results with distinct localization of marker (colloidal gold probes coupled either to IgG or protein A). Probes signifying presence of serotonin were distinctly localized over all heteromorphous granules in argentaffin cells and, in addition, over some of the more monomorphous, rounded granules in a second cell type whose granules all were covered by probes showing localization of the PYY antigen. The results suggest that serotonin in endocrine cells of the gut is not confined to the enterochromaffin type but may also be present in trace amounts in non-enterochromaffin endocrine cells storing peptide hormones. Since probes marking sites of PYY were deposited over some heteromorphous granules in enterochromaffin cells, the evidence obtained also suggests that PYY may occur in low concentration in these cells. The distribution of probes in the sections indicated that antigenic sites were confined to granules in the cells.

Cell Nucleus↗

PubMed1986

Human osteogenic sarcoma: fine structural localization of adenosine triphosphatase.

The localization of ATPases in 7 osteogenic sarcomas of osteoblastic, chondroblastic and fibroblastic type was investigated at the fine structural level using two types of substrates: one with lead as capturing ion and one with strontium (the latter presumed to reveal sites of Na+-K+-dependent transport ATPase). Reaction product with the lead-ATP medium was located on the plasma membrane and the membranes bordering subjacent vesicles and vacuoles in all the various types of osteoblastlike and fibroblastlike cells and also in types 1 and 3 chondroblastlike cells, and multinucleated giant cells believed to be neoplastic. Furthermore, deposits of reaction product were demonstrated in lysosomelike organelles in all the aforementioned cells. Except in the case of chondroblastlike cells, precipitates marking the localization of enzyme were confined to areas of the plasma membrane where adjacent cells were closely applied (the free surface lacked precipitates). In chondroblastlike cells the reaction product was usually deposited along the whole plasma membrane. Presence of L-Homoarginine or L-Tetramisole in the incubation medium in concentrations that have been shown to completely abolish alkaline phosphatase activity did not affect the occurrence of the reaction product with ATP as substrate indicating that the enzyme hydrolysing ATP was substrate-specific. Reaction product marking sites of Na+-K+-dependent ATPase was confined to plasma membranes and lysosomes of cells in vessel walls. The observations strengthen the notion obtained in studies on the localization of alkaline phosphatase, namely that osteoblastlike, chondroblastlike, and fibroblastlike cells in osteogenic sarcomas are histogenetically related to one another and to those multinucleated giant cells that presumably are of a neoplastic nature.

Adenosine Triphosphatases↗

PubMed1986

Quantitation of the nuclear DNA content in tissue prepared for electron microscopy.

The possibility of determining the cellular DNA content in tissue prepared for electron microscopy (EM) was investigated. Comparative cell population DNA analyses of deparaffinized and Epon-embedded sections of equal thickness (2 micron) from the same tumor (osteosarcoma) showed almost identical DNA distribution curves. The methodologic prerequisites for both EM and DNA analyses of identical cells was then investigated. Using a special technique involving consecutive sections of 500-600 A and 2-micron thickness for EM morphology and Feulgen staining, respectively, nuclear parts of identical cells could be identified in both types of sections. Thus, cells selected in ultrathin sections could be identified in corresponding Feulgen-stained Epon-embedded sections for cytophotometric DNA analysis. All normal cells (lymphocytes, fibroblasts, macrophages), as defined and selected at the ultrastructural level, proved to be diploid (with normal DNA content) as determined in the corresponding Feulgen-stained Epon-embedded sections, whereas all analyzed osteosarcoma cells, except one, were aneuploid. The results indicate that 2-micron thick Feulgen-stained, Epon-embedded specimens from osteosarcoma, previously fixed in glutaraldehyde and OsO4, may be used for cytophotometric DNA measurements. Since aneuploidy is almost exclusively found in malignant cells, this criterion may serve as a marker for such cells. Consequently, whenever it is questionable whether in a mixed population a given cell selected for ultrastructural study is malignant or not, DNA cytophotometry may give decisive information, provided aneuploidy can be demonstrated.

Bone Neoplasms↗

PubMed1985

Human osteogenic sarcoma: fine structure of hard tissue areas.

The structure of hard tissue areas (with osteoid and calcified matrix) in 10 osteoblastic, chondroblastic, and fibroblastic osteogenic sarcomas was studied in the electron microscope. Neoplastic cells commonly associated with these areas and presumably actively involved in the production of hard tissue were osteoblast-like cells types 1 and 3, chondroblast-like cells type 1, and fibroblast-like cells, as defined and characterized in previous studies. The cells differed from those in soft tissue areas of osteogenic sarcomas in but one respect: they usually showed presence of irregular extrusions at their surfaces. Other types of osteoblast-like and chondroblast-like cells occurred rarely or not at all. Two types of multinucleated giant cells were recognized in these areas, one showing a fine structure reminiscent of that in osteoclasts, the other probably being of a neoplastic nature and engaged in the production of the calcifying matrix. The evidence suggested that neoplastic osteoblast-like, chondroblast-like, and fibroblast-like cells as well as certain multinucleated giant cells might all be involved in the mineralization process and/or the formation of osteoid in osteogenic sarcomas. Although phenotypically of highly variable appearance, all these different cells may thus functionally (and probably histogenetically) be closed related. The mineralization process in the tumor tissue appeared to be a modification of what occurs in normal ossification, possibly with an alternative or complementary pathway involving the production of spherical bodies with layered contents.

Adolescent↗

PubMed1985

Human osteogenic sarcoma: fine structural localization of alkaline phosphatase.

The localization of alkaline phosphatase in eight osteogenic sarcomas of osteoblastic. chondroblastic, and fibroblastic type was investigated at the fine structural level using beta-glycerophosphate as substrate and lead as capturing ion. Final product marking localization of alkaline phosphatase was deposited over plasma membranes and associated subplasmalemmal vesicles and vacuoles in various types of osteoblastlike, chondroblastlike, and fibroblastlike cells as well as certain multinucleated giant cells. Presence of L-homoarginine or L-tetramisole in the incubation medium, and incubation at 65 degrees C, prevented the deposition of final product, suggesting that the enzyme studied was "bone specific." The evidence obtained was compatible with the notion that the different cells showing presence of reaction product were functionally and histogenetically closely related and all were likely to be capable of bone production.

Adolescent↗

PubMed1984

Levels of malondialdehyde production in rat liver following loading and unloading with iron.

Rats were given daily injections of an iron sorbitol citric acid complex in a total dose of 50 mg Fe3+/100 g of body weight and either killed immediately after iron loading, or investigated 2 months later. Among the latter animals, one group was subjected to weekly phlebotomies in order to mobilize iron from the stores, while another group was not further treated. Quantitation of iron and malondialdehyde production was performed on homogenates of liver, kidney and spleen from controls and rats in the different experimental groups, and the distribution of iron in granular form was studied in the livers by means of electron microscopy. The results showed substantially increased amounts of iron in the organs studied after iron-loading and also augmented malondialdehyde production in the liver and kidney (but not in the spleen). A decreased malondialdehyde production was recorded two months after iron-loading in the kidney and spleen of non-bled animals; this decrease was exaggerated in the same organs from bled animals. The production of malondialdehyde as well as the iron content in the livers of both bled and non-bled rats 2 months after iron loading was higher than in the controls. The evidence obtained suggested that the accumulation of iron in the liver was causally related to increased lipid peroxidation. Judging from the morphological appearances this change did not result in cell damage, the only pertinent morphologic alteration being the occurrence of iron particles in the lysosomal vacuome and the cell sap.

Animals↗

PubMed1984

Human osteogenic sarcoma: fine structure of the chondroblastic type.

The fine structure of representative regions of four chondroblastic osteogenic sarcomas was studied. These regions contained four morphologically distinguishable subtypes of chondroblastlike cells. In addition, multinucleated giant cells, fibroblastlike cells, and macrophagelike cells were present, along with small populations of unclassifiable cells forming at least two subgroups of cells likely to be of a neoplastic nature. With only one exception, all types of chondroblastlike cells were separated by wide zones of extracellular matrix. The large multinucleated cells showed a fine structure that differed from that seen in multinucleated giant cells of other tissues. The evidence suggested that the multinucleated cells in the chondroblastic osteogenic sarcomas were active in phagocytic functions. It is not clear whether or not they are neoplastic in nature. Osteoblastlike cells were not encountered in the chondroid areas of the osteogenic sarcomas studied. On the basis of the findings it is concluded that the observed fine structural polymorphism of the chondroblastlike cells may reflect differences in maturation and differentiation among these cells. The most well-differentiated cells (type 1) appear to be able to exert secretory functions.

Adolescent↗

PubMed1984

Human osteogenic sarcoma: fine structure of the fibroblastic type.

The fine structure of representative regions of nine fibroblastic osteogenic sarcomas was studied. As judged by light microscopic criteria, the tumors represented both highly malignant (grades 3-4) and less malignant (grade 2) varieties. By electron microscopy, six basic cell types were found in the selected regions (fibroblastlike, histiocytelike, and myofibroblastlike cells, along with xanthoma cells, multinucleated giant cells, and undifferentiated cells). In addition, occasional osteoblastlike cells were encountered. Fibroblastlike cells in general, and especially in grade 2 tumors, showed a fine structure, enabling differentiation from osteoblastlike cells. Multinucleated giant cells were of two morphologic types, and the fine structure appeared to be related to the malignancy potential and differentiation of the tumors. Many multinucleated giant cells in grade 2 tumors had a ruffled border and appeared to be highly active in digestive events (especially phagocytosis of whole cells and portions of cells). Accumulation of variable amounts of lipid in droplet form was common in the various types of cells present in the tissues. The observations were discussed with particular emphasis on the interrelationships and functional roles of the cells.

Adolescent↗

PubMed1983

An electron microscopic study of the post-partum involution of the rat uterus. With a note on apparent crinophagy of collagen.

During pregnancy the increase in mass of the rat uterus has been accounted for mainly by hypertrophy rather than hyperplasia of the smooth muscle cells and by an increase in collagen content. Following parturition the rat uterus regains its non-pregnant weight within little more than a week. Autophagy is a likely mechanism for the reduction in size of the smooth muscle cells. However, many previous investigations have failed to demonstrate an extensive lysosomal apparatus in uterine smooth muscle cells, a morphologically detectable prerequisite for augmented autophagy. The superfluous collagen has been assumed to be digested by macrophages. In the present electron microscopical study the involution of the rat uterus was followed at various time points post-partum. The results indicated that three pathways were involved namely, autophagocytosis, heterophagocytosis and crinophagy. Autophagocytosis was noted in smooth muscle cells--apparently a means to reduce their size. In some instances extensive autophagy appeared to lead to cell death. Macrophages and also to some extent fibroblasts have the ability to endocytose collagen and cell debris including split off portions of smooth muscle cell cytoplasm. The evidence obtained suggested that at the time of parturition the (pro)collagen synthesized but not yet secreted was retained within the fibroblasts and degraded by means of crinophagy.

Animals↗

PubMed1983

Effect of iron on the stability of macrophage lysosomes.

Mouse peritoneal macrophages exposed to 60 microM Fe3+ in culture showed a pronounced decline in survival rate and an enhanced capacity for lipid peroxidation, as estimated by the formation of malondialdehyde. The iron-exposed cells contain secondary lysosomes loaded with iron as demonstrated by transmission electron microscopy, energy dispersive X-ray micro-analysis and the sulphide-silver method. The macrophages concentrated within their lysosomes the weak base acridine orange (AO) when the latter was added to the medium in a low concentration (1:10(5)). When cells were viewed under continuous illumination with short wave blue light in a fluorescence microscope, AO-exposed cells initially showed a brilliant red granular fluorescence and subsequently a progressive redistribution of AO into the cell sap and the nucleus with resultant green fluorescence. This redistribution of AO was associated with the disappearance of the normal granular reaction product pattern of the lysosomal marker enzyme acid phosphatase (AP), as demonstrated with a Gomori-type reaction, and later with cell death. The redistribution of AO and AP from the lysosomal vacuome to the cell sap under the influence of blue light occurred markedly more rapidly in macrophages containing iron loaded lysosomes than in control cells. The findings indicate that the presence of iron in lysosomes decreases the proton-retaining ability of their bordering membranes, possibly by way of enhanced metal (iron) catalyzed lipid peroxidation. It appears that leakage of AO signifies destabilization of the lysosomal membrane.

Animals↗

PubMed1983

Human osteogenic sarcoma: fine structure of the osteoblastic type.

The fine structure of representative regions of 13 osteoblastic osteogenic sarcomas was studied. These regions contained four morphologically distinguishable subtypes of osteoblastlike cells. In addition, fibroblastlike and chondroblastlike cells were present, along with multinucleated giant cells, leukocytes, macrophagelike cells, and small populations of histogenetically unclassifiable (but probably neoplastic) cells. The morphologic evidence was compatible with the view that the variations in appearance among the subgroups of osteoblastlike cells reflected differences in maturation and differentiation of these cells. In at least one subgroup, the morphologic findings suggested that the cells were capable of manufacturing a secretory product. The multinucleated giant cells occurring in genuine tumor areas appeared to be closely related to neoplastic osteoblasts. The presence of chondroblastlike cells in the tissues illustrates that cells with a diverging differentiation can occur in an osteoblast-dominated cell population. This agrees with the view that the neoplastic cells originate from a mesenchymal stem cell with potential for multifaceted differentiation.

Adolescent↗