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Biomedical subjects

H Jacobsson

Publications and source records attributed to H Jacobsson.

At least 127 records · Page 7Linked to original sources
PubMed1982

Percutaneous bone biopsy with a simple punch instrument. Indications, results and complications.

A simple punch instrument for percutaneous bone biopsy with a large needle, developed and used at this hospital since 1964, is described. An analysis of 235 punctures of unclear lesions in vertebrae and pelvis, performed by radiologists guided by fluoroscopy, was made with regard to indications, results and complications. Most of the patients had metastatic disease. An average accuracy of 79 per cent was found. It is concluded that closed bone biopsy, instead of indirect delaying diagnostic techniques or open biopsy, should be performed at an early stage in the examination of obscure bone lesions.

Adolescent↗
PubMed1982

Fibrinolysis inhibition after a major standardized trauma.

The present investigation on 20 patients after total hip replacement surgery has confirmed that the posttraumatic increase of the fibrinolysis inhibition activity (FIA) in serum and plasminogen-depleted serum is due to the primary fibrinolysis inhibitor (PFI, alpha 2-antiplasmin). This protein exists in at least two forms and it was indicated that PFI alpha with affinity to immobilized plasminogen, is mainly responsible for the posttraumatic variations of the FIA in plasminogen-depleted serum. PFI beta, the major part of the PFI-related antigen, which has none or low such affinity, displayed weak FIA and relatively small increase after the surgical trauma. It was established that the posttraumatic increase of the FIA was not derived from the low molecular weight fraction in serum of those patients.

Aged↗
PubMed1982

Thrombectomy and arteriovenous fistula for iliofemoral venous thrombosis in fertile women.

Thirteen women of fertile age with left-sided iliofemoral venous thrombosis were treated with thrombectomy and a temporary arteriovenous fistula in the groin. In nine patients, the appearance of thrombosis could be related to pregnancy; in three of these, obstetric complications occurred. Diagnosis was obtained by antegrade and retrograde phlebography. After three months, the arteriovenous fistula was closed. Anticoagulant treatment was given from the time of diagnosis and for a total of six months. Patency of the iliac vein was determined by phlebography or venous occlusion plethysmography, or both. Based upon these findings, a short term patency rate of 85 per cent was achieved. Analysis of the material indicates a multifactorial pathogenic mechanism in the development of iliofemoral venous thrombosis. Important factors are pregnancy, obstetric complications, mechanical factors causing flow resistance in the iliac vein, hormonal factors and defective fibrinolysis.

Adult↗
PubMed1978

Induction of specific unresponsiveness against the C3H M1s=antigen in mice, increase of suppressive capacity of C3H X CBA F1-lymphocytes after sensitization against CBA lymphoid cells.

Injection of adult CBA mice with lymphocytes from C3H X CBA donors leads to a specific reduction of the MLC reactivity of the recipients' lymphocytes. This effect is mediated by a population of F1-lymphocytes which do not seem to possess the relevant MLC-stimulatory M1s-antigen. In this investigation we have shown that injection of C3H X CBA mice with CBA, but not C3H spleen cells enhances the 'tolerogenic' capacity of their thymocytes and lymph node cells. A similar enhancing effect was achieved by 'educating' C3H X CBA lymphocytes in irradiated CBA, but not C3H hosts. The results indicate that C3H X CBA lymphocytes reduce the MLC-reactivity by reacting immunologically against CBA T-cells which possess recognition structures for the relevant M1s antigen. Lymphocytes of C3H X CBA mice can be sensitized against such recognition structures which thus renders them more 'tolerogenic'.

Animals↗
PubMed1977

Activated mouse lymphocyte release factors which modulate the proliferative responses of other lymphocytes.

Supernatants of mouse lymphocyte cultures briefly exposed to phytomitogens or various antigens may contain factors---lymphokines--which are mitogenic for lymphocytes in the absence of any additional stimulatory agents. Whether such supernatants can modulate the proliferative responses of lymphocytes exposed to phytomitogens or allogeneic cells is the subject of the present investigation. Active supernatants were obtained from cultures of either mouse lymph node cells incubated with concanavalin A bound to Sepharose or allogeneic cells for 24 h. Both types of active supernatants reduced the 3H-thymidine uptakes of lymph node cells and cortisone-resistant--medullary--thymocytes in response to various phytomitogens and allogeneic cells. In contrast, normal suspensions of mouse thymocytes, containing both cortical and medullary lymphocytes, exhibited stimulations higher than anticipated. The results indicate that activated lymphocytes may release factors which reduce proliferative responses of some lymphocytes, presumably immunologically mature T cells, and enhance the responses of other lymphocytes which are relatively immature.

Animals↗
PubMed1976

Complex nature of the production of 'effector' cells and their interaction with target cells in the M-antigen system of the mouse.

The capacity of lymphocytes from mouse strain CBA to generate 'effector' cells against the H-2-compatible, M-antigen-incompatible strain C3H and their interaction with such target cells were investigated. It was observed that CBA lymphocytes injected in, and 5 days later obtained from, the spleens of irradiated C3H X CBA hybrids ('educated cells') could strongly inhibit the growth of C3H X CBA bone marrow cells but were almost nonresponsive to C3H X C57BI bone marrow targets (H-2-incompatible). CBA lymphocytes educated in irradiated C3H X C57BI hosts displayed reactivity against C3H X C57BI and CBA X C57BL but not against C3H X CBA bone marrow target cells. Additional tests indicated that the M antigen determined by C3H is expressed to approximately the same extent on C3H X CBA and C3H X C75BL cells and that the M antigen on C3H does not cross-react immunologically with antigens on C57BL cells. Moreover, it was observed that CBA X C57BI lymphocytes were triggered to cell proliferation by C3H antigens but were unable or had a highly reduced capacity to develop 'effector' cells in response to this antigenic stimulus. These results indicate that generation of 'effector' cells and their interaction with target cells are very complex processes.

Animals↗
PubMed1976

Partial tolerant state against H-2 disparate cells. No impaired specific reactivity in MLC, GVH, or antibody production.

Injection of CBA mice with H-2-compatible lymphoid cells from C3H hybrids induces a specific reduction of the mixed lymphocyte culture (MLC) response of their lymphoytes. This is not the case after injection of H-2-disparate C3H-hybrid cells, presumably because they are rapidly eliminated due to the immune response of the host. This investigation shows that CBA mice injected with CBA X C57Bl cells (H-2-disparate) at an age of 0-3 days, but not older, develop a specifically reduced MLC response after infusion of C3H X C57Bl cells as adults, indicating that they were tolerant to the C57Bl-determined antigens. However, lymphocytes from such mice showed a normal reactivity against C57Bl as assessed by MLC, graft-versus-host tests, and capacity to produce specific antibodies.

Age Factors↗
PubMed1975

Disappearance of specifically mlc-responsive lymphocytes in cba mice injected with cells from the h-2-compatible, m-antigen-incompatible strain c3h.

The mixed lymphocyte culture (MLC) response of lymphocytes from CBA mice injected with spleen cells from the H-2-compatible strain C3H was studied. The response of CBA lymphocytes against C3H cells was higher than that obtained against H-2-disparate strains. Intravenous injection of C3H cells resulted in a markedly increased MLC response in lymph nodes but not in the thymus during the first 1 to 3 days. Thereafter, the specific MLC response decreased drastically, far below that of nonimmunized animals. Reactivity was back to normal in the thymus after approximately 4 weeks but remained suppressed in lymph nodes for more than half a year. A decreased response was also noted in spleen, Peyer's patches, and the peripheral blood lymphocyte population. Such a state of relative unresponsiveness was achieved by injecting as few as 10-4 C3H spleen cells. This exhaustion of the specific MLC response could not be explained by production of blocking serum factors or of cells that can inhibit the MLC response. The strong MLC response obtained by lymphocytes from nonimmunized animals may be due to disparity at the newly detected M locus. This antigenic system is characterized by strong MLC stimulatory capacity and no detectable production of humoral antibodies or development of effector cells capable of killing M-antigen-bearing cells. A possible explanation of the results is that the CBA mice become chimaeric for a long time after injection of C3H cells. This prolonged exposure to a foreign transplantation antigen may lead to exhaustion of the specifically responsive lymphocytes.

Animals↗
PubMed1975

Specifically decreased MLC response of lymphocytes from CBA mice injected with cells from the H-2-compatible, M-antigen-incompatible strain C3H. Lack of such effect after injection of H-2-disparate C3H-hybrid cells.

The mixed lymphocyte culture (MLC) response of lymphocytes from CBA mice against C3H cells was studied after injection of spleen cells from C3H mice or C3H hybrids. Intravenous infusion of C3H cells resulted in a strongly suppressed specific MLC response, but this was not the case when cells from H-2-incompatible hybrids of C3H mice were injected. However, when mixtures of cells from the two parental strains--C3H cells and H-2-incompatible cells--were injected into CBA mice, there was a strongly suppressed MLC response to C3H cells. Mice that were hybrids between CBA and an H-2-disparate strain showed a depressed MLC response against C3H after injection of cells from hybrids between C3H and the same H-2-disparate strain. The results may indicate that a suppression of the MLC response to the strongly stimulatory non-H-2 antigen on C3H lymphocytes develops only when the immunizing cells can survive in the host for long periods, thus exhausting the pool of specifically responsive cells. The presence of another foreign transplantation antigen, such as H-2, on the same cells shortens the survival of the cells in the recipient.

Animals↗
PubMed1975

Reduced capacity to produce specific 'effector' cells after injection of CBA mice with C3H cells.

Lymphocytes from mice of strain CBA are strongly MLC-responsive to lymphocytes from the H-2-compatible but M-antigen-incompatible strain C3H. This strong reactivity disappears after infusion of CBA mice with C3H lymphocytes. This study shows that the host-versus-graft reactivity (swelling of local lymph node after antigen injection) is specifically reduced after injection of CBA mice with C3H times CBA spleen cells. However, lymphocytes from such mice showed a specifically increased GVH reactivity (inhibition of erythroid cell growth) compared with lymphocytes from unimmunized mice. Lymphocytes from normal CBA mice showed a high proliferative rate in the spleens of irradiated C3H times CBA mice. Such 'educated' cells showed strongly increased specific GVH reactivity. Lymphocytes from CBA mice previously injected with C3H times CBA cells showed reduced capacity to proliferate when injected into irradiated C3H times CBA hybrids and a poor capacity to develop new 'effector' cells reactive against C3H times CBA bone marrow target cells. The results indicate that the presence of specifically 'MLC-responsive' lymphocytes in a lymphoid cell population is a prerequisite of its production of 'effector' cells able to respond in this GVH assay.

Animals↗
PubMed1975

Evidence of different cell populations in the mouse thymus releasing and responding to mitogenic factor.

The thymocyte population of mice treated with cortisone was examined at various times with respect to its relative capacity to be triggered to DNA synthesis by soluble phytomitogens or mitogenic factors (MF) released by lymph node cells exposed to phytomitogens. The capacity of the thymocyte population to produce MF in response to phytomitogen exposure was also examined. We found that the relative blastogenic activity of both phytomitogens and MF on thymocytes increased as the cell number of the thymus was reduced by the cortisone treatment. However, the reactivity to phytomitogens increased to a higher extent. During the subsequent regeneration of the organ the stimulability of the cells by phytomitogen decreased far below that of MF. The relative capacity of thymocytes to produce MF seemed to parallel their phytomitogen reactivities. One possible explanation of the results is that there exists one subpopulation of cells in the thymus more responsive to phytomitogens than to MF and another more responsive to MF than to phytomitogen. It is possible that the cells that are phytomitogen-responsive are those that can produce MF.

Animals↗
PubMed1975

Release of mitogenic factor by mouse lymph node cells stimulated with PHA in vitro. Inhibition of this phenomenon by the addition of thymocytes.

Thymidine uptakes of mouse lymph node cells and thymocytes in response to phytomitogen lectins were investigated in vitro. It was observed that mixtures of lymph node cells and thymocytes yielded higher 3H-TdR incorporations than expected when exposed to concanavalin A (Con A) or pokeweed mitogen (PWM), but lower incorporations than anticipated with phytohemagglutinin (PHA) as a stimulant. The observed enhancement of the response could be explained by factors which are stimulatory for thymocytes released by the lymph node cells. However, such mitogenic factors (MF) were released not only by Con A and PWM exposed cells but also by PHA expose lymph node cells. Further experiments showed that the admixture of thymocytes inhibited the release of MF by lymph node cells exposed to PHA but not to Con A or PWM. Since medullary thymocytes did not exhibit any inhibitory activity, it is likely that cortical thymocytes are responsible for this effect. The mechanism by which thymocytes inhibit MF production of lymph node cells exposed to PHA is not clear. MF was efficiently produced by lymph node cells cultured with PHA in "thymocyte-conditioned" medium and the MF activity was only marginally decreased by absorption with thymocytes. The results are discussed in the light of recent findings showing that thymocytes may both enhance and depress the immune response of other lymphocytes.

Animals↗
PubMed1975

Characterization of mouse cells releasing or responding to mitogenic factor induced by phytomitogens in vitro.

Mouse lymphocyte populations exposed to mitogen were tested for their capacity to release factors that stimulate other lymphocytes to synthesize DNA or enhance their response to mitogens in vitro. The target lymphocyte for this mitogenic factor(s) (MF) was also characterized. The results showed that lymph node and spleen cells release more MF than thymocytes upon exposure to Con A, PHA or PWM in vitro. The T cells were found to be largely responsible for MF production, since cell suspensions depleted of phagocytic cells did not exhibit any decreased ability to produce MF and spleen cells from congenitally athymic (nude) mice produced no detectable MF activity. The MF stimulated thymocytes, lymph node cells, and spleen cells to synthesize DNA. Spleen cells from nude mice were also stimulated. The MF released by lymphocytes in response to Con A was found to induce DNA synthesis of lymphocytes in itself and did not require the presence of mitogen. It is concluded that phytomitogen lectins stimulate T cells to synthesize DNA and to release soluble factor(s) which are mitogenic for both T and B cells. The latter cells may thus be unresponsive to the phytomitogen, but still undergo blast transformation.

Animals↗