Biomedical subjects

U Stauffer

Publications and source records attributed to U Stauffer.

7 recordsLinked to original sources

PubMed2005

Early peritoneal macrophage function after laparoscopic surgery compared with laparotomy in a mouse mode.

BACKGROUND: The authors previously demonstrated postoperative preservation of the immune function measured by delayed-type skin reaction and tumor growth after laparoscopic surgery, as compared with laparotomy. For further elucidation of the origin of the demonstrated immune preservation, peritoneal macrophage (PMo) function was investigated 1 h after different surgical procedures. METHODS: Female NMRI mice were divided into five groups: anesthesia only, abdominal skin incision, laparotomy, peritoneal carbon dioxide (CO2) insufflation, and peritoneal air insufflation. Escherichia Coli phagocytosis, tumor necrosis factor-alpha (TNF-alpha), transforming growth factor-beta1 (TGF-beta1), and interleukin-10 (IL-10) release of isolated PMo were investigated. RESULTS: All invasive interventions reduced the PMo phagocytosis by factors of approximately 2 to 4.7, as compared with the sham control group. Spontaneous ex vivo TNF-alpha release was significantly increased whenever the abdominal cavity was exposed to ambient air. The macrophage's ability to release TNF-alpha after E. coli exposure was diminished in the abdominal air exposure groups, as compared with the CO2 insufflation group. CONCLUSION: Reduced phagocytosis 1 h after surgical interventions suggests a contribution of PMo to the altered immune function. When exposed to CO2, PMo show a decreased basal TNF-alpha release. However, PMo also show an increased TNF-alpha release after a second immune stimulation (E. coli), suggesting a greater competency of interaction in an immune defense reaction after CO2 exposure.

Animals↗

PubMed1999

Long term substitution and specific immune responses after transfer of bovine peripheral blood lymphocytes into severe combined immunodeficient mice.

The long term immune responsiveness of bovine peripheral blood lymphocytes engrafted into severe combined immunodeficient mice (bovine PBL SCID mice) was analyzed. After intraperitoneal transfer (i.p.) of 2x10(7) bovine PBL into SCID mice, FACS analysis revealed successful engraftment of bovine CD4 and CD8+ T cells in the peritoneal cavity, the peripheral blood, spleen, lymph nodes, bone marrow, and thymus of reconstituted mice for up to 13 weeks. As shown by immunocytochemistry in sections of spleens from SCID mice 16 weeks after substitution, bovine T and B cells were localized perivasculary forming pseudofollicular structures. Nevertheless, histopathology of spleen and liver from bovine PBL SCID mice revealed pathological alterations indicating rejection of xenogenic cells or graft versus host disease (GVHD). On the functional level, i.p. transfer of bovine PBL into SCID mice induced increasing levels of bovine IgM and IgG in the sera of recipients. Bovine Ig could be detected up to 20 weeks. Immunization of SCID mice reconstituted with PBL of normal donors with dinitrophenol (DNP)-edestin induced a weak specific bovine antibody response in recipient mice. In contrast, a secondary specific bovine IgG response was observed after antigen restimulation of SCID mice reconstituted with PBL from calves preimmunized either with DNP-edestin or keyhole limpet hemocyanin (KLH) showing functional T cell-independent and -dependent antibody responses of bovine PBL SCID mice. Our data demonstrate that transfer of bovine PBL into SCID mice leads to a long term engraftment of bovine cells in lymphatic and non-lymphatic organs inducing a functional substitution of T and B cell immune response of SCID mice. Therefore, bovine PBL SCID chimera can serve as a small animal model for the analysis of bovine lymphopoiesis and infectious diseases of cattle.

Animals↗

PubMed1997

Primary resection of soft-tissue sarcomas: yes and no.

UNLABELLED: The primary tumour site is the most common origin in relapses of soft-tissue sarcomas (75%). Therefore, prevention of a relapse depends mainly on local tumour control in the primary therapeutic regimen. There are three modalities of treating children with sarcomas: surgical removal, radiation therapy and systemic chemotherapy. The aim is to reach a complete removal of the primary tumour and to preserve all vital and functionally useful structures. Under this aspect we evaluated the results of 22 patients, treated for soft-tissue sarcoma at the University Children's Hospital, Zurich, between 1989 and 1995. The age of the patients ranged between 3 and 16 years. The tumours of 11 patients were primarily resected, but in 9 patients the removal was incomplete (7 microscopically, Z macroscopically). Only 2 patients had a complete primary removal of their tumours, both being paratesticular sarcomas. In 11 patients an incisional biopsy was performed. Two of these patients had stage IV initially. Two tumours were removed completely in a second operation. Six patients did not need any further resections because of a very good response to chemotherapy. In 1 patient with unresectable tumour it was possible to remove the tumour almost completely after primary chemotherapy. CONCLUSIONS: Our experience with primary chemotherapy in soft tissue sarcomas showed the following advantages: 1. The low morbidity after biopsy allows a rapid beginning of the treatment. 2. In case of a very good response to chemotherapy it is possible to avoid a second operation. 3. The information of a poor response to chemotherapy makes the decision for an extensive surgery easier. 4. The possibility of a delayed, but complete removal of a primarily unresectable tumour will be more likely after chemotherapy. 5. Only a small group of tumours should be considered for removal during a primary surgical procedure.

Adolescent↗

PubMed1993

The level of N-region diversity in T cell receptors is not pre-ordained in the stem cell.

The alpha beta T cell repertoires of adults and neonates are distinctly different. For example, T cell receptors (TcR) from adult animals have substantial N-nucleotide addition at their V-D-J junctions while those from neonatal animals do not. This dichotomy reflects a rather abrupt change in expression of the terminal deoxynucleotidyl transferase (TdT) gene in thymocytes on day 4 after birth. We have asked whether this change is due to the differentiation of successive waves of stem cells harboring different potentials for TdT expression, a scenario like the one proposed to explain developmental regulation of gamma delta T cell repertoires. Reconstitution of adult severe combined immunodeficiency mice with either fetal liver or adult bone marrow precursors gave rise to T cells with substantial N-region diversity in their TcR, even at the earliest points of reconstitution. It is most likely, then, that the abrupt change in TdT gene expression in day 4 thymocytes is due to an environmentally induced switch-on.

Animals↗

PubMed1982

Cellular response and resistance to the primary infection of rats and mice with Nematospiroides dubius.

LEWIS rats, in contrast to NMRI mice, have been found to be resistant to an oral infection with Nematospiroides dubius (Baylis, 1926). Comparative studies of the peritoneal response to infection showed a strong increase in the cell number predominantly of eosinophilic and neutrophilic granulocytes in rats, whereas in mice only a weak reaction occurred. As shown by the chemiluminescence response to either antibody--or complement-coated larvae, the granulocyte reaction caused an increased production of toxic oxygen species by the peritoneal cells. Purified granulocytes from rats or mice showed about a ten-fold higher oxidant generation than macrophages. The higher metabolic activity of granulocytes of either species resulted in rapid and strong killing of antibody or complement-coated infective larvae by granulocytes of either species, whereas macrophages failed to express a significant larvicidal potency. From these results we concluded that the activated oxygen species derived from the metabolic burst of granulocytes are essential for an effective control of the primary infection with N. dubius. This suggests that the rapid and strong granulocyte response may form the basis of the resistance in rats. Thus, in mice, the ability of N. dubius to prevent the granulocyte response may serve as an escape mechanism of the parasite.

Animals↗

PubMed1980

Childhood urolithiasis.

59 children with urolithiasis were seen between 1969 and 1977 (8 1/2 years). Calculi from 50 patients were analyzed by X-ray diffraction. Half of the patients were 0-4 years old, and in this age group males greatly predominated (76%). Calculi in 26 patients were of infectious, and in 15 patients of metabolic origin (cystinuria 7, idiopathic hypercalciuria 5, primary hyperoxaluria 3), whereas 18 were idiopathic. Most infectious stones contained struvite, and most idiopathic stones contained calcium oxalate. An infectious etiology was observed in 55% of the 0-5-year-old children (n = 33), but in only 20% of the 10-16-year-old ones. In contrast, the percentage of idiopathic stones rose from 18% in the youngest to 70% in the oldest age group, although the absolute numbers were similar in all age groups, Childhood urolithiasis in Switzerland is thus primarily observed in young male patients and is usually secondary to a definable cause.

Adolescent↗

PubMed1979

Relationship between histocompatibility antigens, other surface determinants and the IgE receptor on rat mast cells.

Rat alloantibodies recognizing classical transplantation antigens (CTA) or non-H-1 determinants were able to compete effectively with monomeric IgE or IgG-coated sheep erythrocytes for receptor sites on the rat mast cell surface. Inhibitory capacity, however, was entirely confined to anti-CTA antibodies of the IgG2a subclass, whereas IgG1 antibodies lacked this ability. Analogously, F(ab')2 fragments of anti-CTA antibody consistently failed to affect IgE binding, but exposure of cell-bound F(ab')2 to anti-rat IgG restored its inhibitory capacity. From these results it was concluded that receptor sites recognizing the Fc portion of the anti-CTA molecule are involved in the inhibition process. Based on a cytotoxicity assay and on comparative absorption studies on alloantisera, the existence and relative amount of CTA and I region-associated antigens on purified rat mast cells and lymph node cells were analyzed. Whereas the CTA concentration per unit surface area on both cell types was very similar, rat mast cells consistently lacked Ia antigens.

Absorption↗