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Biomedical subjects

R Gottschalk

Publications and source records attributed to R Gottschalk.

At least 19 recordsLinked to original sources
PubMed2001

Effect of recombinant human erythropoietin and intravenous iron on anemia and disease activity in rheumatoid arthritis.

OBJECTIVE: To investigate whether treatment of anemia of chronic disease (ACD) in patients with rheumatoid arthritis (RA) with recombinant human erythropoietin (rHu-Epo) in combination with intravenous (i.v.) iron influences health related quality of life (HRQoL) and clinical outcome including disease activity. METHODS: Thirty patients with ACD and RA were treated with 150 IU/kg rHu-Epo twice weekly for 12 weeks. As well, in case of functional iron deficiency 200 mg of iron-sucrose per week was given intravenously. Vitality and fatigue as dimensions of HRQoL were evaluated by the vitality subscale of the Short Form-36 (SF-36-VT) and the Multidimensional Assessment of Fatigue (MAF). Muscle strength was measured by the Muscle Strength Index. RESULTS: All 28 patients completing the study responded to treatment; 23/28 patients developed functional iron deficiency and received i.v. iron (mean absolute dose 710 +/- 560 mg). Average hemoglobin concentration increased from 10.7 +/- 1.1 to 13.2 +/- 1.0 g/dl after a mean treatment period of 8.7 +/- 2.3 weeks. Muscle strength increased from 43.5 +/- 11.2 to 49.1 +/- 12.9 and SF-36-VT from 28.2% +/- 14.3% to 47.1% +/- 20.8%. while fatigue decreased (MAF from 34.7 +/- 9.3 to 25.0 +/- 11.3). Among the disease activity variables the number of swollen/tender joints, erythrocyte sedimentation rate, Disease Activity Score, and RA Disease Activity Index improved significantly during treatment. CONCLUSION: Treatment of ACD in RA patients with rHu-Epo and i.v. iron is safe and effective in correction of anemia, increases muscle strength. improves vitality, and lowers fatigue. In addition we observed a reduction of disease activity.

Adult↗
PubMed2000

Establishment of stable multilineage hematopoietic chimerism and donor-specific tolerance without irradiation.

BACKGROUND: Induction of tolerance to organ transplants will increase graft survival and decrease patient mortality and morbidity. Radiation-induced cytoreduction/ablation followed by donor hematopoietic cell reconstitution has been the most consistently successful approach to experimental tolerance induction. However, reluctance of clinicians to expose recipients to radiation has hampered its clinical application. METHODS: In the studies described, administration of polyclonal antilymphocyte serum (ALS), donor-specific bone marrow (DSBM) (150x10(6) cells), and sirolimus (24 mg/kg) in a completely mismatched murine model (B10.A donor, C57B/10 recipient) produced 100% indefinite (>250 days) skin graft survival. The level and character of donor-specific chimerism was evaluated with flow cytometry. RESULTS: Specific tolerance was confirmed by continued acceptance of primary and secondary donor-specific skin allografts and rejection of third-party grafts. The level and duration of chimerism induced was directly related to the dose of DSBM administered. Mice given 150x10(6) DSBM cells showed levels of 8-10% donor peripheral blood mononuclear cell chimerism by 30 days, and these levels persisted indefinitely (>250 days) in association with permanent tolerance of donor grafts. Eighty percent of donor chimeric cells were B lymphocytes (MHC class I and II positive, Fc receptor positive, CD45/B220 positive but negative for CD4, CD8 and Thy 1.2) and 20% were sorted in the macrophage monocyte population. CONCLUSIONS: These studies demonstrate for the first time that cytoreduction/ablation with ALS combined with sirolimus and reconstitution with donor bone marrow induces tolerance and chimerism in a completely mismatched murine combination. The use of ALS and sirolimus, currently employed therapies in clinical transplantation, and the lack of requirement for radiation make this tolerance protocol attractive for clinical application.

Animals↗
PubMed2000

Total iron-binding capacity and serum transferrin determination under the influence of several clinical conditions.

In this study TIBC and serum-transferrin concentrations were determined by immunochemical turbidimetry, immunochemical nephelometry and radial immunodiffusion under normal and pathological clinical conditions. A total of 246 (123 male/123 female) patients were included [iron deficiency: 60 (18/42), iron overload: 56 (39/17), chronic inflammation: 47 (23/24), undefined diseases: 35 (16/19), healthy volunteers 48 (27/21)]. The data show that determination of TIBC from conversion of transferrin values using a constant factor results in significantly higher values compared to conversion with a function of first degree. For clinical practice the influence of different diseases is negligible. This study indicates that it is not possible to develop a universal algorithm for the conversion of transferrin values into TIBC.

Adolescent↗
PubMed2000

Iron-overload and genotypic expression of HFE mutations H63D/C282Y and transferrin receptor Hin6I and BanI polymorphism in german patients with hereditary haemochromatosis.

Gene variations of HFE, a HLA-class I like molecule, are highly associated with hereditary haemochromatosis (HH). Functional as well as molecular studies of the HFE protein have indicated that the molecule is involved in iron metabolism and that the HFE gene variations observed among HH patients affect its interaction with the transferrin receptor (TfR). In the present study, we have therefore analysed the relationship between the HFE gene variants, C282Y and H63D, and body iron status among 85 German HH patients. In addition, two TfR gene polymorphism, TfR-Hin6I and TfR-BanI, were typed that have been reported to define ethnically distinct haplotypes. As controls we used 251/159 healthy German blood donors. Seventy-eight (92%) patients were C292Y homozygous, the H63D mutation was present in five (6%) patients with none of the patients being H63D homozygous. Serum transferrin, transferrin saturation and liver iron content were determined prior to therapeutic intervention. Among C282Y homozygous patients serum ferritin levels (2294 +/- 3174 vs. 463 +/- 224 microg L-1, P < 0.0001) and transferrin saturation (86 +/- 18% vs. 62 +/- 25%, P = 0.048) were elevated significantly compared with C282Y and/or H63D heterozygous patients. In addition, the liver iron content (291 +/- 165 vs. 138 +/- 95 micromol g-1, P = 0.028) and liver iron index (6.4 +/- 2.8 vs. 3.2 +/- 2.3, P = 0.019) were increased among C282Y homozygotes compared with C282Y heterozygotes. In contrast, no difference was observed between patients and controls regarding the distribution of TfR-Hin6I and TfR-BanI alleles. These data indicate that the iron intake is higher among C282Y homozygous patients compared with C282Y heterozygous or C282Y/H63D compound heterozygous individuals and supports the functional role of the HFE protein in iron metabolism whereas the TfR gene variants seem to have no influence on iron uptake.

Blood Donors↗
PubMed1999

Erythropoietin and iron.

Serum ferritin concentration is most informative in estimating the amount of storage iron available for a particular individual. The serum transferrin receptor concentration, in contrast to serum ferritin, provides direct information about any deficit in the adequacy of iron supply to the erythropoiesis. The combination of serum transferrin receptor and serum ferritin provides complete information about storage and functional iron compartments. Using this combination along with the hemoglobin concentration, it is possible to define the iron nutritional status completely. Inflammatory conditions as well as parenteral iron administration interfere, however, with the direct and quantitative ferritin to storage iron relationship and, therefore, have to be considered carefully with respect to diagnostic purposes. The diagnostic use of the serum transferrin receptor is presently limited because of limitations in methodology and definition (standardization) of reference ranges.

Anemia, Iron-Deficiency↗
PubMed1998

Determination of an improved sirolimus (rapamycin)-based regimen for induction of allograft tolerance in mice treated with antilymphocyte serum and donor-specific bone marrow.

BACKGROUND: Posttransplant donor-specific bone marrow (BM) infusion in mice treated with antilymphocyte serum (ALS) induces specific unresponsiveness (tolerance) to skin allografts, which can be augmented by the adjuvant administration of chemotherapeutic immunosuppressive agents. The purpose of this study was to determine the optimal dose and timing of administration of sirolimus (rapamycin) to induce maximal skin allograft survival in ALS-treated, BM-infused recipients. METHODS: DBA/2 donor skin grafts were placed on B6AF1 recipients (class I- and II-disparate). Groups of recipient mice (n=10 each) received combinations of the following treatment protocols: ALS, 0.5 ml on days -1 and 2; BM, 25x10(6) donor-specific cells on day 7; sirolimus, 6, 12, 18, or 24 mg/kg at times indicated; and cyclosporine, 50 mg/kg at times indicated. The immune status of putatively tolerant animals was examined with mixed lymphocyte cultures, cell-mediated lympholysis assays (CML), and limiting dilution analyses. RESULTS: When administered in conjunction with ALS/BM, a single dose of sirolimus (6 mg/kg) on days 21, 18, 14, 10, or 7 resulted in median skin graft survival times of 35, 26, 40, 46, and 103 days, respectively, versus a median survival of 27 days in mice given ALS and BM alone. The addition of cyclosporine to sirolimus (6 mg/kg) given on day 7 or days 7 and 10 did not significantly increase graft survival over that achieved with sirolimus alone. A single dose (18 or 24 mg/kg) of sirolimus administered on day 7 to ALS/BM-treated recipients resulted in 100% 200-day skin graft acceptance. Tolerant mice demonstrated nonspecific suppression of the mixed lymphocyte culture assays at 90 and 200 days and a nonspecific reduction of the CML assay at 50 days. By 200 days, the third-party CML response was restored, whereas donor-specific cell-mediated cytotoxicity remained suppressed. There was a donor-specific reduction in the number of alloreactive cytotoxic T lymphocyte clones by limiting dilution assay at 120 days. In vivo specificity of immunosuppression induced with this protocol was demonstrated by indefinite survival of second donor-specific skin grafts placed on putatively tolerant mice at day 90, whereas third-party skin grafts were rejected in 14 days. CONCLUSION: A single dose of sirolimus (18-24 mg/kg) administered on day 7, within the context of an ALS/BM immunosuppressive regimen, reliably induces permanent skin allograft acceptance in this model. In vitro measures of immunocompetence demonstrated an early nonspecific suppression of the recipients immune status and later recovery of third-party immunoreactivity. In vivo testing indicates an operationally tolerant state that is donor-specific 90 days after treatment.

Animals↗
PubMed1998

Use of pharmacologic immunosuppression to augment the specific unresponsiveness (tolerance) to skin allografts induced by donor-specific bone marrow in antilymphocyte serum-treated mice: the unique effect of sirolimus.

Tolerance produced with ALS treatment, DSBM, and sirolimus involves multiple mechanisms of a specific and nonspecific nature. In eventual clinical application for tolerance induction, sirolimus (rapamycin) has great potential for augmenting the tolerogenicity of the ALS/BM regimen.

Animals↗
PubMed1998

HFE codon 63/282 (H63D/C282Y) dimorphism in German patients with genetic hemochromatosis.

Genetic hemochromatosis (GH) is closely associated with genes of the major histocompatibility complex (MHC) on chromosome 6. Recently, a candidate gene for GH, with structural similarities to MHC class I genes, designated HLA-H and presently named HFE, has been cloned. The HFE gene is localized telomeric to the MHC and several reports have indicated that the HFE gene is mutated in GH patients. In the present study we have analyzed the relationship of HFE gene variants and disease manifestation in GH patients and family members. Fifty-seven patients with GH, 73 family members and 153 healthy blood donors were studied for the amino acid dimorphism at codon 63 (His63Asp=H63D) and codon 282 (Cys282Tyr= C282Y) of the HFE gene. The codon 63 and 282 dimorphism were defined by PCR amplification of genomic DNA samples and restriction enzyme digestion using RsaI/SnaBI for C282Y and BclI/MboI for H63D. Ferritin, transferrin serum levels and total iron-binding capacity were determined prior to therapeutic intervention. The Tyr-282 substitution occurred in 53 (93%) of patients compared with 8 (5.2%) of controls (OR=169, P<0.0001). Fifty-one (90%) patients were Tyr-282 homozygous. In contrast, the Asp-63 substitution was present in 5 (8.8%) of the patients compared with 34 (22%) of controls (OR=0.39, P=NS) with none of the patients being homozygous. In Tyr-282 homozygous GH patients serum ferritin levels, transferrin saturation, liver iron and liver iron index were elevated significantly compared to Tyr-282-negative patients, whereas no difference was observed between Tyr/Cys-282 heterozygous and Tyr-282-negative patients.

Aspartic Acid↗
PubMed1998

Clinical trial on the effect of regular tea drinking on iron accumulation in genetic haemochromatosis.

BACKGROUND: Black tea is known to be a potent inhibitor of intestinal absorption of non-haem iron at least in healthy subjects. AIMS: To investigate this effect in patients with genetic haemochromatosis, and, more importantly, the effect of regular tea drinking on the accumulation of storage iron in these patients over one year. PATIENTS: Investigations were carried out on 18 patients with clinically proven genetic haemochromatosis. For the study of storage iron accumulation, they were separated into a group instructed to drink a particularly tannin rich tea regularly with meals and a control group. METHODS: Intestinal iron absorption from a test meal was measured using whole body counting. Body iron stores were evaluated quantitatively by exhaustive phlebotomy, using haemoglobin, saturation of serum iron binding capacity, and serum ferritin for the assessment of body iron status. RESULTS: A significant reduction in iron absorption was observed when the test meal was accompanied by drinks of tea instead of water. In the tea drinking group, the increase in storage iron was reduced by about one third compared with that of the control group. CONCLUSIONS: Regular tea drinking with meals reduces the frequency of phlebotomies required in the management of patients with haemochromatosis.

Adult↗
PubMed1998

Hepatic and portal vein flow pattern in correlation with intrahepatic fat deposition and liver histology in patients with chronic hepatitis C.

OBJECTIVE: The flow pattern in hepatic veins depends on cardiac physiology and liver histology. The aim of our study was to determine the dependence of the flow pattern of hepatic and portal veins in relation to histologic features in patients with chronic hepatitis C. SUBJECTS AND METHODS: In 135 patients with chronic hepatitis C, the Doppler sonography spectrum of the right hepatic vein was classified as triphasic, biphasic, or monophasic. The flow of the portal vein was characterized according to the undulation (velocity(max,min)). A liver biopsy was performed during sonography, and biopsy specimens were semiquantitatively evaluated on a histologic activity index and a score of the hepatic fat content. Multiple logistic regression analysis was used to identify the histologic features that might contribute to the type of flow pattern. RESULTS: The hepatocyte fat content was the only variable associated with an independent effect on the type of flow pattern (monophasic versus triphasic; odds ratio, 16.26; 95% confidence interval, 6.38-41.45; p < .0001). A pronounced undulation in the portal vein was associated with portal inflammation but not with other parameters of the histologic activity index or the intrahepatic fat deposition. CONCLUSION: On sonography, the normal flow pattern in the right hepatic vein is triphasic. The monophasic flow pattern in the right hepatic vein is mainly caused by intrahepatic fat deposition and occasionally by inflammatory or fibrotic changes. Conversely, the flow pattern of the portal vein is mainly influenced by portal inflammation.

Adult↗
PubMed1997

[Sonographic detection of lymph nodes in the hepatoduodenal ligament].

BACKGROUND AND OBJECTIVE: In patients with chronic inflammatory liver disease modern methods of ultrasound can visualize enlarged lymph nodes in the porta hepatis. Number, size and total volume of lymph nodes in the hepatoduodenal ligament in healthy subjects and in patients with chronic viral hepatitis without cirrhotic changes were investigated. PATIENTS AND METHODS: Sonographic localization of the perihepatic lymph nodes was validated at post-mortem and intraoperatively. Following this, 92 healthy persons (57 men, 35 women; average age 33 +/- 9 years) and 48 patients (30 men, 18 women; average age 35 +/- 8 years) with serologically and histologically confirmed chronic viral hepatitis (30 with hepatitis C, 18 with hepatitis B) were investigated by abdominal ultrasound (Acuson 128, 3.5 and 5 MHz). The hepatoduodenal ligament was assessed according to a standardized procedure with demonstration of the lymph node positions ventral to the portal vein and between the portal vein and the inferior vena cava. RESULTS: Satisfactory imaging of the hepatoduodenal ligament was achieved in 83 of the 92 healthy persons (90.2%) and in 44 of the 48 patients with chronic viral hepatitis (91.7%). Lymph nodes were demonstrated in 60 of the 83 healthy subjects (72.3%) and in 43 of 44 patients with chronic hepatitis (97.7%). The mean perihepatic lymph node volume was 2.8 +/- 2.6 cm3 (0-9.7 cm3) and was thus significantly smaller (P = 10(-9)) than in the patients with chronic viral hepatitis (19.8 +/- 15.7 cm3 [0-62.4 cm3]). There was no significant difference in lymph node volume between patients with hepatitis B and those with hepatitis C (23.1 +/- 14.9 cm3 vs 18.9 +/- 15.6 cm3; P = 0.16). CONCLUSIONS: With adequate ultrasound technique enlarged lymph nodes can be demonstrated in the porta hepatis of almost all patients with chronic hepatitis B or C. Lymph nodes of normal size can often be imaged also in healthy persons if their localization is known. The demonstration of lymph nodes in the hepatoduodenal ligament in the area of the porta hepatis and the determination of their volume can be helpful in the diagnosis of chronic inflammatory liver disease.

Adult↗
PubMed1997

Use of CTLA4-Ig in combination with conventional immunosuppressive agents to prolong allograft survival.

BACKGROUND: The objective of our study was to determine the effectiveness of CTLA4-Ig, a novel immunosuppressive agent, in augmenting allograft survival when combined with either cyclosporine, sirolimus, donor-specific bone marrow alone (BM), or bone marrow in conjunction with antilymphocyte serum (ALS). METHODS: Full-thickness skin allografts were used in C3H to B6AF1 (class I mismatch) and AKR to C57BL/6 (complete mismatch) models. Groups of mice (n=6-14) were treated with various combinations of the following treatment protocols: murine CTLA4-Ig, L-6 control Ig, sirolimus, cyclosporine, ALS, or ALS/BM. RESULTS: In the class I mismatch model, L-6 control Ig had no effect whereas use of CTLA4-Ig alone resulted in a doubling of the median graft survival compared with controls. The addition of either sirolimus or cyclosporine to CTLA4-Ig increased graft survival over that achieved with CTLA4-Ig alone. CTLA4-Ig demonstrated no efficacy when used in combination with BM, ALS, or ALS/BM. CTLA4-Ig was clearly less effective in the complete mismatch model. CONCLUSION: These data suggest that CTLA4-Ig may be effective clinically in combination with cyclosporine or sirolimus but offers no additional effectiveness in combination with antilymphocyte serum with or without donor-specific bone marrow.

Abatacept↗
PubMed1997

Superiority of sirolimus (rapamycin) over cyclosporine in augmenting allograft and xenograft survival in mice treated with antilymphocyte serum and donor-specific bone marrow.

BACKGROUND: Sirolimus is a potent immunosuppressive agent with great therapeutic potential. The objective of our study was to evaluate the efficacy of sirolimus versus cyclosporine in augmenting the unresponsiveness induced by an antilymphocyte serum (ALS)/donor-specific bone marrow (BM)-based regimen across three levels of histoincompatibility: class I and II disparate (DBA/2 to B6AF1), complete mismatch (AKR to C57BL/6), and xenograft (ACI rat to B6AF1). METHODS: Full-thickness skin grafts were taken from donors and placed on recipients in standard fashion. Seven groups of recipient mice (n=10-28) received various combinations of the following treatment protocols: sirolimus, 1.5 mg/kg (3.0 mg/kg for xenografts) every other day from day 0 to day 12; cyclosporine, 50 mg/kg every other day from day 10 through 22; ALS, 0.5 ml on days -1 and 2 for allografts and days -1, 2, and 4 for xenografts; and BM, 25 million donor-specific cells IV on day 7. RESULTS: The administration of ALS or ALS/BM resulted in modest but significant prolongation of skin graft survival in all combinations tested. Cyclosporine combined with ALS or ALS/BM significantly extended allograft survival compared with ALS or ALS/BM alone (P<0.05) but had no effect on xenograft survival. In contrast, the combination of sirolimus with ALS or ALS/BM resulted in a two- to threefold increase in allograft survival and over a fourfold increase in xenograft survival when compared with the comparable cyclosporine-based regimen. Additionally, lymphocytes isolated from class I and II incompatible mice with skin grafts surviving >100 days demonstrated markedly reduced interleukin 2 and interferon-gamma secretion in response to irradiated donor-specific lymphocytes in culture. CONCLUSIONS: In the regimens tested, sirolimus was superior to cyclosporine in augmenting donor BM-induced skin graft prolongation in ALS-treated mice across all levels of histoincompatibility.

Adjuvants, Immunologic↗
PubMed1996

PGG-glucan, a leukocyte-specific immunostimulant, does not potentiate GVHD or allograft rejection.

PGG-glucan is an immunomodulator which can enhance the host response to infection. Phase I/II clinical trials have documented the safety and potential efficacy of this compound to reduce postoperative infectious complications in high risk surgical patients. Organ transplant recipients may benefit from this drug due to their high rates of postoperative infectious complications. A rat cardiac rejection model (ACI --> Lew) and a mouse skin graft model (C3H/HeJ --> B6AF1/J) were used with four treatment arms (control, Cyclosporine A (CsA), antilymphocyte serum (ALS), and CsA + ALS with and without PGG-glucan). Small intestinal allografts (Lew --> LBNF1) were performed in rats to evaluate GVHD. In the mouse GVHD model, donor splenocytes were given to irradiated recipients (C57BL/6 --> B6AF1), with and without PGG-glucan treatment. There was no difference in survival between PGG-glucan treatment and placebo for the control, CsA, and CsA + ALS groups in rat cardiac recipients. Recipients receiving ALS and treated with PGG-glucan survived a median of 42.5 days versus 63.5 days for those ALS-treated animals not receiving PGG-glucan (P = 0.045). In the remaining groups there was no difference in survival between PGG-glucan-treated groups and the control groups. PGG-glucan did not shorten survival in three of four treatment groups in the rat cardiac rejection model. High dose ALS with PGG-glucan did result in a marginal decrease in survival in cardiac allograft recipients. If the one outlying animal with indefinite survival is excluded, the difference is not statistically significant (P = 0.098). These results show that even though PGG-glucan has immunostimulatory properties, it does not significantly potentiate rejection or GVHD in these animal models. This preliminary work may be important in determining whether PGG-glucan can be safely given to immunosuppressed organ transplant recipients to reduce postoperative infectious complications.

Adjuvants, Immunologic↗
PubMed1996

Increased pigmentation in scleroderma.

OBJECTIVE: Increased pigmentation is found in patients with scleroderma (systemic sclerosis, SSc) even in areas that have never clinically been involved with skin thickening. We wanted to determine if the pigmentation is due to subclinical sclerodermatous changes, or a systemic factor such as an increase in adrenocorticotropic hormone (ACTH). METHODS: To determine if clinically uninvolved skin that is pigmented differs from nonpigmented skin, skin biopsies were taken from patients with scleroderma from 2 different sites: (1) from pigmented but otherwise clinically normal skin, and (2) from nonpigmented clinically normal skin adjacent to the first site. Biopsies were examined by a dermatopathologist for evidence of dermal and epidermal changes. Cosyntropin stimulation tests were performed after baseline cortisol and ACTH samples were obtained. RESULTS: Six patients with diffuse SSc (dSSc) and 4 with limited SSc (ISSc) had skin biopsies. Patients with dSSc were more likely than those with ISSc to have increased pigmentation in uninvolved skin. Pigmented skin specimens had either a higher content of epidermal melanin and/or a more severe degree of pigmentary incontinence with a higher number of dermal melanophages in the superficial dermis. The cosyntropin stimulation tests were normal and there were no differences between subjects with diffuse and limited SSc or between those with and without increases in pigmentation. CONCLUSION: Clinically uninvolved skin in many of these patients with SSc was abnormal, and subtle changes of SSc were present, especially in the pigmented biopsies. There was no evidence of adrenal deficiency in these patients. It is difficult pathologically to differentiate the changes in pigmented compared to unpigmented skin in patients with SSc, except for changes of increased melanin and pigmentary incontinence.

Adrenocorticotropic Hormone↗