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Biomedical subjects

W Ryd

Publications and source records attributed to W Ryd.

At least 55 records · Page 3Linked to original sources
PubMed1984

The elimination of i. v.-injected tumor cells. Studies with 125IUDR labelled cells in 4 syngeneic murine tumor systems.

We have studied the elimination of radiolabelled (125IUDR) i.v. injected tumor cells. We have used four different murine tumors with different abilities to metastasize and with different metastasis patterns. The elimination of the tumor cells was determined by gamma-countings from different organs. The results were compared with the elimination of heat killed and x-ray sterilized tumor cells. We found a poor correlation between on the one hand the clearance of tumor cells from the blood and distribution of radiolabelled cells and on the other hand the ability of the tumors to metastasize and the metastasis distribution upon i.v. injection. The radioactivity outside the first capillary bed seemed mainly to come from dead cells.

Animals↗
PubMed1983

Local tumour cell seeding by fine-needle aspiration biopsy. A semiquantitative study.

We have performed fine-needle biopsies from solid or ascites-growing mouse tumours. The biopsies were taken via striated muscle or the peritoneal cavity of healthy mice syngeneic with the tumours and the tumour-bearing animals. The incidence of tumour takes in these new mice were compared with the intramuscular or intraperitoneal transplantability of the tumours. In order to estimate more accurately the number of seeded cells, we also performed aspiration biopsy through the leg muscles of healthy animals into ascites-growing tumours labelled with 125IUDR. The resulting radioactivity in the leg muscle was compared with the radioactivity of the ascites tumour cells. The studies indicate that one may seed 10(3)-10(4) cells, and sometimes more, into the needle track with fine-needle aspiration biopsy from extremely cellular and dedifferentiated tumors.

Animals↗
PubMed1982

125IUDR labelling efficiency and cytotoxicity for murine tumours in vivo and in vitro.

We have reviewed the literature on 125IUDR (5-iodo-2-deoxyuridine), the DNA label of choice for cell distribution studies. In previous studies, the cytotoxicity in relation to labeling efficiency has often been inadequately investigated or reported. We have studied four syngeneic mouse tumours and compared in vitro with in vivo labelling procedures. Ascites tumours could be effectively labelled in vivo by IP injections of 60-80 muCi per mouse during 24 h, without apparent cytotoxicity. Comparable in vitro labelling was also effective, but caused a dose-related cytotoxicity, as measured by growth rate and transplantability. Comparison with 'cold' IUDR disclosed that the toxicity was not chemical, but radiological. Our attempt to label a solid lymphoma in vivo was unsuccessful, obviously because the tumour grows too slowly. We conclude that 125IUDR-labelling is suitable for cell distribution studies, but in view of labelling efficiency versus cytotoxicity the procedure has to be adjusted to each new tumour individually.

Animals↗
PubMed1981

Alteration of a tumor cell distribution pattern by cytochalasin B.

Cytochalasin B pretreatment of tumor cells alters the distribution pattern of metastases after i.v. injection. We now have studied Cytochalasin B cell pretreatment affects the i.v. distribution and elimination of 125IUDR-labeled TA3-Ha tumor cells. We found no differences between control and CB-treated cells in their initial distribution. but 4-8 hours after the injection, in the redistribution phase, there were more CB cells than control cells extrapulmonally. Rather than a consequence of CB paralysis, we interpret the results in terms of altered surface properties of CB cells during their recovery.

Animals↗
PubMed1981

Histological studies of small-intestinal biopsies from infants with low rate of weight gain.

Eighty-one children aged 4-18 months with unsatisfactory weight gain were investigated for organic diseases; the investigation included small-intestinal biopsy. Sixteen had total villous atrophy, in most cases due to gluten intolerance. Transient disease, e.g. cow's milk protein intolerance, was probable in 7 children with subtotal atrophy. In 18 children the only abnormal finding was an increased number of inflammatory cells in the mucosa, a finding which was probably of no clinical significance. Planimetric measurement showed good agreement between the mucosal surface/volume ratio and an ordinary histological grouping of the mucosa. A significant correlation was found between the rate of weight gain during the period preceding investigation and mucosal surface/volume ratio.

Biopsy↗
PubMed1980

Adhesion of metastatic and non-metastatic carcinoma cells to glass surfaces.

Adhesion in vitro is described in cells from a tumor pair originating from a single methylcholanthrene-induced mouse carcinoma. One member of this tumor pair shows a high incidence of metastases while the other does not metastasize. Cells from the non-metastasizing carcinoma were found to form close and focal contacts with a glass substrate consecutively, as do normal mouse kidney epithelial cells. Cells from the metastasizing carcinoma, however, had only limited areas of close contact and generally failed to form focal contacts. It is suggested that this alteration in cell-substrate adhesion contributes to the release and mobility of metastatic cells.

Animals↗
PubMed1979

Ascites tumors in CBA mice. Characterization of two new tumors, a carcinoma and a sarcoma in solid and ascites form, with regard to cell surface properties and transplantability.

Two ascites tumors in syngeneic CBA mice are described, viz., MCB 21-AA and MCB 31-AA, with their solid progenitors: A sarcoma (MCB 21-SS) and a squamous cell carcinoma (MCB 31-SC), induced by gastric feeding of 20-methylcholanthrene. The ascites tumor cells have certain characteristics in common, which they do not share with either cells from the solid tumors or even with cells from solid ascites tumors (-21-AS and -31-AS=ascites tumor transplanted s.c.). Presumably some of these differences, for instance, in PAS stainability, electrophoretic mobility and lectin agglutinability, are due to enzyme treatment required to bring solid tumors into suspension. Between the two ascites tumors there are certain differences in cell size, aggregability, and growth rate. They are similar, however, in requiring large cell doses for transplantation in syngeneic animals, which is also true for the solid (SS and SC) tumors. MCB 21 and -AA even required fewer cells for transplantation in allogeneic A mice than in syngeneic CBA mice. MCB 31-AA is also allotransplantable. The pattern of spread, after i.v. cell injection, is almost exclusively to the lungs for all tumor lines.

Animals↗
PubMed1979

Discrepant effects of interferon murine syngeneic ascites tumors and their solid metastasizing counterparts.

The effects of interferon on mice with syngeneic tumors growing either intraperitoneally or as solid tumors were analyzed. The same dose that depressed the growth of ascites tumors, enhanced growth and in one case metastasizability of the corresponding solid tumors. The possibility that this was due to some host reaction is discussed. It seems important to develop animal models for analyzing interferon effects before treatment is initiated in human tumor disease.

Animals↗
PubMed1979

Ascites tumors in CBA mice. 2. Ultrastructural aspects on ascites conversion.

We have studied four syngeneic murine tumors, a fibrosarcoma, a squamous cell carcinoma and their two ascites-converted counterparts, by transmission electron microscopy. The ascites tumors were investigated both as cell suspensions (AA-tumor) and as solid tumor (AS-tumor). We have also studied the ascites tumors, enzymatically produced cell suspensions of the AS-tumors and solid original tumors by scanning electron microscopy. The two ascites tumors are totally de-differentiated and lack intercellular junctions. This, we think, is a prerequisite for ascites growth. But the ascites tumors show no peculiar ultrastructural features in comparison with other undifferentiated malignant tumors. We found no morphological cell alternations by the enzymatical dissociation procedure used to bring the solid tumors into suspension. Differences between the AS and AA tumors can be ascribed to differences in proliferation rates.

Animals↗
PubMed1978

Metastasis spread from syngeneic murine tumours. Establishment of a test protocol for comparisons between ascites tumours and their progenitors.

We have transformed two new MC-induced tumours, a sarcoma (MCB31-SC), into ascites form. When transplanted s.c. these ascites tumours grow as solid, quite undifferentiated tumours, (AS = ascites solid tumours). We compared the metastasizibility of the AS tumours with that of the parent tumours. In doing so, we used both the tail and the hind leg as transplantation sites. The tumours can be radically removed from both sites by amputation, which prolongs the survival time of the animals and permits metastases to grow into detectable sizes. As registered grossly and by microscopy, the AS tumours have a greater tendency of spread than the parent (SS/SC) tumours. MCB-21 AS grows quicker than 21-SS and gives rise to more lymph node metastases. When transplanted to the tail the AS tumour also gives a higher incidence of lung metastases. We detected no such difference by leg-transplanted tumours. MCB31-SC did not produce any detectable metastases at all, while 31-AS, particularly from the tail, gave rise to numerous lymph node and lung metastases. There were no differences in tumour size or growth rate to account for this difference. Thus ascites conversion has changed the carcinoma MCB31-SC into an undifferentiated, metastasizing tumour, as detected by our procedure. The design of test protocols to detect metastasizibility is discussed.

Animals↗
PubMed1977

Tumor cell locomotion--a factor in metastasis formation? Influence of cytochalasin B on a tumor dissemination pattern.

The influence of Cytochalasin B (CB) on TA3 ascites tumor cells was studied in vivo in order to assess whether CB-induced cell paralysis would affect the transplanation behavior of the cells and in particular tumor distribution after IV cell infusion ("experimental metastases"). Tumor cell pre-treatment with CB (1 mug/ml) did not alter the SC or IV transplantability of TA3 cells. Pre-treatment with 10 mug/ml CB, in contrast, consistently increased the incidence and number of extra-pulmonary tumor takes from IV transfused cells. The amount of pulmonary tumors was not significantly altered. SC transplantability was not affected by 10 mug/ml CB. The importance of cell mobility and cell surface topography for tumor cell nidation in vessels is discussed.

Animals↗
PubMed1977

In vitro effects of Cytochalasin B on TA3 tumor cells.

We studied the effect of Cytochalasin B (CB) on two lines of the ascites tumor TA3 by microcinematography and scanning electron microscopy. CB induces a dose dependent and reversible cell paralysis. One microgram CB/ml causes a pronounced but incomplete paralysis. The cells retain their general shape but develop numerous blebs. Ten microgram CB/ml causes a complete cell paralysis and a retraction of pseudopods and microvilli. When CB is removed, the cells rapidly regain their original form and motility. The recovery process starts within minutes after CB removal and is almost completed in 15 min.

Animals↗
PubMed1977

Site dependency of TA3 Ha allotransplantability.

An ascites tumor line, TA3 Ha, is allotransplantable i.p. while a sister line, TA3 St, has retained its strain specificity. This study shows that the allotransplantability of TA3 Ha, with very few exceptions, is restricted to the peritoneal cavity and is not operative s.c. or i.v.

Animals↗
PubMed1977

Effect of cell aggregation on intravenous tumor transplantation.

We have studied how the presence of cell aggregates affects the pattern of intravenously induced "experimental metastases" from two syngeneic murine tumors. Aggregates were produced mechanically by centrifugation, or chemically by a lectin (wheat-germ agglutinin). Compared to well-dissociated suspensions, aggregated suspensions tended to give a greater total metastasis volume in the lungs of recipient mice. Disaggregated suspensions, on the other hand, gave rise to more extrapulmonary metastases. Presumably, aggregates are preferentially retained in lung vessels, while single cells are let through to other sites. Nor are aggregates superior to single cells in producing tumor growth when the total metastasis yield is considered.

Abdominal Neoplasms↗