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Biomedical subjects

A Fischer

Publications and source records attributed to A Fischer.

At least 901 records · Page 50Linked to original sources
PubMedDate not supplied

Gene therapy of severe combined immunodeficiencies.

Recent advances in gene transfer in human hematopoietic cells, combined with a better understanding of the genetic aspects of several immunodeficiencies, has offered new opportunities in the domain of gene therapy. Severe combined immunodeficiency (SCID) appear to represent a good model for the application of gene therapy, combining an expected selective advantage for transduced cells, an absence of immunological response to the vector and/or the therapeutic transgene, together with accessibility to hematopoietic stem cells (HSC). Ex vivo retroviral transduction of a therapeutic transgene in HSC prior to transplantation appears to be a particularly effective and long-lasting means of restoring the expression of a mutated gene in the lymphoid lineage. Furthermore, encouraging therapeutic benefits as a result of a gene therapy protocol for the treatment of X-linked severe combined immunodeficiencies (SCID-X1) invites many questions as to the reasons for this therapeutic benefit. This review outlines the results that have been achieved in gene therapy for SCID-X1, ADA-SCID as well as other types of SCID, and discusses the possible relationship between the physiopathology of each disease and the success of relevant trials.

Adenosine Deaminase↗
PubMedDate not supplied

Streptococcus pneumoniae peritonitis postpartum.

A peritonitis caused by an ascending infection is a rare complication postpartum. A 37-year-old woman presented with a secondary peritonitis due to Streptococcus pneumoniae. The patient had given birth to a healthy boy 4 weeks before and showed no symptoms of a bronchitis on admission. An operation was performed after the patient developed an acute abdomen, showing a diffuse peritonitis. High vaginal swabs and blood cultures taken on admission were positive for S. pneumoniae as well as the specimen taken during the operation. Thus we concluded that this was a case of an ascending infection. After antibiotic therapy with penicillin the patient could be discharged 8 days after the operation.

Abdomen, Acute↗
PubMedDate not supplied

Hyper-IgM syndrome.

Explore the source record for details and available documents.

CD40 Ligand↗
PubMedDate not supplied

The isolated perfused liver. a new model using autologous blood and porcine slaughterhouse organs.

INTRODUCTION: Current models of isolated and perfused livers are limited by nonphysiologic perfusates or the need for the use of high numbers of laboratory animals. The present study was performed in order to rectify these difficulties. METHODS: To establish a new isolated perfused liver model, a perfusion circuit was developed using normothermic, autologous hemoperfusion and organs obtained from a slaughterhouse. RESULTS: Stable organ function was maintained over 220 min. The organs displayed physiologic values for measured variables, including oxygen consumption which varied from 5.2+/-1.5 ml/min at 40 min to 5.2+/-2.4 ml/min at 220 min, and bile production (0.15-0.31 ml/min, respectively). DISCUSSION: The present studies demonstrate a new approach for experimental liver perfusion by combining the optimal perfusion medium of autologous blood and slaughterhouse organs as source material.

Alanine Transaminase↗
PubMedDate not supplied

Peripheral stem cells in bone marrow transplantation. Peripheral blood stem cell and gene therapy.

Mobilized peripheral blood stem cells characterized by sustained re-populating ability could be optimal target cells for ex-vivo gene transfer. In spite of very attractive preliminary results obtained in the murine studies, therapeutically efficient gene transfer and expression in human targeted cells must be proven. In recent years, effort has been spent on the identification of factors limiting gene transfer efficiency of haematopoietic stem cells. Increasing knowledge concerning haematopoiesis and gene transfer has helped in identifying a number of limiting factors. These factors as well as the strategies that showed increased retroviral infection of haematopoietic stem cells will be discussed. Finally, the results of the clinical trials will be reported.

Animals↗
PubMedDate not supplied

[Computer assisted production of individual anatomic endoprostheses].

Long-term anchorage of foreign material in vital bone has proven to be the main problem in endoprosthetics. In the authors opinion, modelling of an individual anatomic anchorange component is, at present, the best way to transmit stresses harmoniously in order to utilize functional adaptation of bone and to attain long-term function. The production of a true-to-scale joint model is possible with computer-assisted-tomography. This model of a joint surface or bone canal can be used to construct an individual endoprosthesis prior to surgery. Our procedure of manifactoring a hip stem and a knee-surface-prosthesis is described.

Computers↗
PubMedDate not supplied

Failure of hyperoxic gas to alter the arterial lactate anaerobic threshold.

PURPOSE: Oxygen-enriched gases enable patients and healthy individuals to exercise submaximally with reduced lactate concentration, lower minute ventilation (VE), and less subjective stress compared to normoxia. These findings suggest that hyperoxia may raise the lactate accumulation threshold, also known as the anaerobic threshold (AT). METHODS: This study measured the anaerobic threshold by gas exchange (Gx-AT) and arterial lactate (Lac-AT) methods in normoxia (FIO2 = 0.209) and the Lac-AT in hyperoxia (FIO2 = 0.40). Eight healthy males (age = 30.6 +/- 3.5 years; weight = 73.4 +/- 5.2 kg; VO2max = 41.3 +/- 6.6 mL/kg/min) worked incrementally (25 Watts [W] x 2 minutes) on a cycle ergometer with the legs on three occasions: once in normoxia, twice in hyperoxia. The latter situation enabled a reliability analysis of hyperoxic anaerobic threshold by arterial lactate methods that yielded a correlation coefficient (r) of 0.94 and nonsignificant paired t-ratio. Gas exchange and arterial lactate methods of detecting the anaerobic threshold in normoxia yielded nearly identical VO2 (21.8 +/- 5.4 mL/kg/min vs 21.5 +/- 5.5 mL/kg/min) with an r of 0.98. RESULTS: Contrary to the study's hypothesis, the normoxic Lac-AT (134.4 +/- 35.2 W), expressed in power output at which the lactate threshold occurred, was not significantly different with hyperoxic gas (128.1 +/- 32.7 W). Furthermore, arterial lactate concentration at the breakpoint in normoxia (1.74 +/- 0.50 mmol.l-1) was not significantly affected by hyperoxia (1.68 +/- 1.03 mmol.l-1) nor was it different between the two hyperoxic tests. No significant differences in VE, HR, or CO2-ventilation equivalent at Lac-AT were found between the two FIO2 conditions. CONCLUSIONS: The elevation of estimated PaO2 to 200 mm Hg does not alter the Lac-AT, compared to the normoxic condition, nor does it affect the arterial lactate concentration at its systematic break point in incremental cycling. Lac-AT is a reliable measurement and it can be estimated accurately using the VE/VO2 in conjunction with VE/VCO2.

Adult↗
PubMedDate not supplied

Isolation of the MHC genes encoding the tumour-specific class I antigens expressed on a murine fibrosarcoma.

The C3H UV-induced fibrosarcoma, 1591, is highly immunogenic and, therefore, is readily rejected when transplanted into immunocompetent syngeneic recipients. Previous analysis of 1591 with tumour-specific or H-2-reactive monoclonal antibodies revealed that this antigenicity might be due to the expression of two novel class I major histocompatibility complex (MHC) antigens. In this report we describe the molecular cloning and initial characterization of three genes which account for all of the unique serological class I reactivities observed on this tumour. These include two distinct, but highly conserved, H-2L-like genes, and a third gene the product of which bears determinants which are characteristic of both the tumour and of class I products of the H-2k haplotype. Moreover, each of these genes contains a polymorphic restriction enzyme fragment which is detected in the class I sequences of 1591 relative to normal C3H tissue. Since the expression of these polymorphic class I sequences is relevant to the immunogenicity of 1591, the mutational events by which these genes were generated may be significant to the immunobiology of this tumour.

Animals↗