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C Mueller

Publications and source records attributed to C Mueller.

At least 145 records · Page 8Linked to original sources
PubMed1991

Granzyme A and perforin as markers for rejection in cardiac transplantation.

The use of granzyme A and perforin as markers for rejection after cardiac transplantation has been investigated. Using in situ hybridization we have detected lymphocytes expressing granzyme A and perforin RNA that are infiltrating the donor heart after transplantation. A total of 29 different biopsies from 17 different patients who had undergone cardiac transplantation were examined. Twelve biopsies classified by conventional histological criteria as showing evidence of rejection were found to contain lymphocytes expressing granzyme A and perforin. Seven biopsies classified as showing no histological evidence of rejection infiltrating lymphocytes were found not to be expressing granzyme A or perforin. However, in 10 other biopsies from 5 different patients that had been classified as showing no evidence of rejection by the conventional grading system, lymphocytes expressing granzyme A and perforin were detected. In six of these cases the patient was found to have undergone a subsequent rejection episode. In the other four cases the biopsies were either taken at a very early stage after transplantation and the high doses of immunosuppression used routinely at that stage are likely to have averted any rejection episodes, or it was not possible to follow subsequent rejection episodes. These results, which are statistically significant (p = 0.06), demonstrate that granzyme A- and perforin-expressing lymphocytes can be identified in rejecting biopsies before histological damage is seen. The identification of perforin and granzyme A expression in vivo suggest a possible role for these proteins in the cytolysis that occurs during transplantation rejection. Furthermore, the data presented here suggest that it may be possible to use granzyme A and perforin as early predictive markers of transplantation rejection.

Biopsy↗
PubMed1991

Expression of perforin and granzymes in vivo: potential diagnostic markers for activated cytotoxic cells.

Perforin and granzymes are considered to be instrumental in cell-mediated cytolysis by cytotoxic T cells and natural killer cells. Here, Gillian Griffiths and Christoph Mueller describe the expression of perforin and granzymes, emphasizing studies in vivo, and discuss the possibility that these proteins are useful diagnostic markers for immune responses involving cytolytic cells.

Animals↗
PubMed1991

Standardizing nursing-home admission dates for short-term hospital stays.

In the Institutional Population Component of the 1987 National Medical Expenditure Survey, the definition of a nursing home admission was standardized to ignore the readmission of patients discharged for short-term hospital care. Approximately one out of six persons residing in nursing homes on the survey reference date (January 1, 1987) had been readmitted for this reason. The effect of the standardization was to increase the average length of stay of residents prior to the reference date by approximately 5 months. The percentage of long-stay residents, those living in the facility for more than three years, increased from 31% to 36%. The percentage admitted from the community during the previous year increased from 32% of those admitted in 1986 to 41%.

Aged↗
PubMed1991

Expression of the protease gene HF as a marker in rejecting allogeneic murine heart transplants.

Phenotypic characterization of the inflammatory infiltrate often provides very little information about the fate of a transplant. Therefore we decided to look for functional markers, characteristic for activated effector cells involved in the rejection of primarily vascularized MHC-mismatched heart transplants in mice. Infiltrating cells in the interstitium of eventually rejected allogeneic heart transplants were found to express the gene for the serine esterase HF (granzyme A) in high numbers already on day 2 following transplantation, whereas HF mRNA positive cells were absent, or only rarely found, in syngeneic nonrejecting transplants throughout the entire observation period of 10 days after transplantation. These findings could also become of importance for the prediction of the outcome of organ transplants in humans.

Animals↗
PubMed1991

Expression of adhesion molecules in leprosy lesions.

Leprosy presents as a clinical spectrum that is precisely paralleled by a spectrum of immunological reactivity. The disease provides a useful and accessible model, in this case in the skin, in which to study the dynamics of cellular immune responses to an infectious pathogen, including the role of adhesion molecules in those responses. In lesions characterized by strong delayed-type hypersensitivity against Mycobacterium leprae (tuberculoid, reversal reaction, and Mitsuda reaction), the overlying epidermis exhibited pronounced keratinocyte intracellular adhesion molecule 1 (ICAM-1) expression and contained lymphocytes expressing the ICAM-1 ligand, LFA-1. Conversely, in lesions in which delayed-type hypersensitivity was lacking (lepromatous), keratinocyte ICAM-1 expression was low and LFA-1+ lymphocytes were rare. Expression of these adhesion molecules on the cells within the dermal granulomas was equivalent throughout the spectrum of leprosy. The percentage of lymphocytes in these granulomas containing mRNA coding for gamma interferon and tumor necrosis factor alpha, synergistic regulators of ICAM-1 expression, paralleled epidermal ICAM-1 expression. In lesions of erythema nodosum leprosum, a reactional state of lepromatous leprosy thought to be due to immune complex deposition, keratinocyte ICAM-1 expression and gamma interferon mRNA+ cells were both prominent. Antibodies to LFA-1 and ICAM-1 blocked the response of both alpha beta and gamma delta T-cell clones in vitro to mycobacteria. Overall, the expression of adhesion molecules by immunocompetent epidermal cells, as well as the cytokines which regulate such expression, correlates with the outcome of the host response to infection.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Effects of glucosamine on lysis, glycerol formation, and sporulation in Myxococcus xanthus.

Glucosamine (GlcN), which has previously been shown to rescue fruiting body formation, lysis, and sporulation in a developmental mutant (G. Janssen and M. Dworkin, Dev. Biol. 112:194-202, 1985), induced lysis in vegetative and developing wild-type cells and inhibited fruiting body formation. It also resulted in a transient, intracellular increase in the concentration of glycerol, a known sporulation inducer, and sporulation of the surviving cells. Phospholipase activity, which was shown to be normally developmentally regulated, increased 7.6-fold after treatment of vegetative cells with 50 mM GlcN. Likewise, autocidal activity, which normally increased 18 to 24 h after the initiation of development, increased 20% when vegetative or developing cells were exposed to GlcN. Two mutants resistant to GlcN-induced lysis (MD1021 and MD1022) were isolated and showed neither an increase in autocide production nor an increase in phospholipase activity in response to added GlcN. MD1021 was developmentally deficient, and GlcN rescued fruiting body formation as well as phospholipase activity and autocide production. We propose that GlcN exerts its lytic effect by regulating the activity of phospholipase enzymes that release autocides, compounds that are believed to be responsible for developmental autolysis. GlcN-induced sporulation was found to depend on several factors: the initial cell density, the amount of lysis induced by GlcN, and the presence of tan-phase variants. An initial cell density of greater than 2 x 10(5) cells per ml was required to support GlcN-induced sporulation, and sporulation did not occur unless 50 to 75% of these cells had lysed. Mutants that were resistant to GlcN-induced lysis also did not sporulate in the presence of GlcN. The effects of GlcN on developing cells depended on the concentration of GlcN added; the addition of low concentrations of GlcN resulted in enhancement of sporulation, while higher concentrations resulted in the inhibition of sporulation. The ultrastructure of GlcN-induced spores resembled that of spores induced by the exogenous addition of glycerol, in contrast to spores isolated from mature fruiting bodies. A model by which GlcN may regulate both lysis and sporulation is presented.

Drug Resistance, Microbial↗
PubMed1991

Most CD8+ cells in skin lesions of CD3+ CD4+ mycosis fungoides are CD3+ T cells that lack CD11b, CD16, CD56, CD57, and human Hanukah factor mRNA.

To define further the characteristics of CD8+ cells in skin lesions of CD3+ CD4+ mycosis fungoides (MF), the authors used single- and double-label immunohistologic techniques and in situ hybridization to detect antigens and transcripts associated with certain types of cytotoxic or suppressor function. The cytotoxic markers included CD16, CD56, CD57, and an anti-sense probe for human Hanukah factor (HuHf) mRNA. Analysis of 23 cases demonstrated that lesional CD8+ cells were CD3+ T cells that generally lacked expression of any of the cytotoxic markers studied. Analysis of another 10 cases confirmed the CD3+ T-cell lineage of lesional CD8+ cells and demonstrated that these cells also lacked expression of the suppressor-associated marker, CD11b. In aggregate, these results indicate that most CD8+ cells in CD3+ CD4+ MF skin lesions are of T-cell rather than NK-cell differentiation. Their overall phenotype suggests that they may be major histocompatibility complex (MHC)-restricted cytotoxic T cells lacking appreciable levels of HuHF serine protease. Because the induction of CD8+ suppressor T cells is mediated by CD4+ T cells expressing the CD45RA+ RO- phenotype, CD45 epitope expression was studied in 15 MF cases. The vast majority (13/15) contained CD3+ CD4+ tumor cells that were CD45+ RA- RB+ RO+ 2B11+. This phenotype is consistent with memory T cells rather than suppressor-inducer T cells, and correlates with the paucity of phenotypically defined suppressor T cells in CD3+ CD4+ MF skin lesions.

Antigens, CD↗
PubMed1990

Impaired production of tumor necrosis factor in breast cancer.

Spontaneous and lipopolysaccharide (LPS)-induced production of tumor necrosis factor (TNF) by peripheral blood macrophages was investigated in breast cancer. Whereas spontaneous TNF production by macrophages derived from patients with breast cancer was comparable with the one found in healthy controls (P greater than 0.1), LPS-stimulated macrophages derived from patients in the disease-free interval as well as with metastatic breast cancer were found to produce significantly lower amounts of TNF, as compared with macrophages derived from healthy control individuals (P less than 0.0005). However, the production of TNF did not significantly differ between the two patient populations (P greater than 0.05). The impairment of LPS-induced TNF production did not depend upon such characteristics of the primary tumor as size, axillary lymph node and estrogen receptor status, or upon the fact of administration of adjuvant chemotherapy and, in patients with metastatic disease, hormone treatment. To further investigate cytokine production by macrophages, spontaneous and LPS-induced interleukin-1 (IL-1) production was investigated also. However, no difference was found between patients and controls concerning IL-1 generation. The authors thus conclude that LPS-induced TNF production was impaired in breast cancer independent of the presence of detectable metastatic disease, whereas IL-1 production remained unimpaired.

Antineoplastic Agents↗
PubMed1990

A ubiquitous CCAAT factor is required for efficient in vitro transcription from the mouse albumin promoter.

Among the various factors binding to DNA elements within the mouse albumin promoter, NF-Y is the only one present at identical concentrations in the nuclei of all examined tissues. NF-Y binds to albumin promoter element C, which contains the sequence CCAAT. To determine whether this factor augments in vitro transcription from the albumin promoter, an extensive point-mutation analysis was performed within the promoter element C. In liver extracts, six out of the ten mutations result in a strong inhibition of NF-Y binding and in a concomitant decrease in promoter activity. Two mutations that increase the affinity of the C-element for NF-Y also augment the transcription efficiency from the albumin promoter. A similarly strong correlation of NF-Y-binding with transcription efficiency has also been observed in spleen nuclear extracts. The liver-enriched CCAAT and enhancer binding factor C/EBP also recognizes the C element. In contrast to NF-Y, no correlation between the affinity of mutant C-elements for C/EBP and transcriptional activity could be observed in liver nuclear extracts.

Animals↗
PubMed1990

Expression of T cell receptor genes in the thymus: localization of transcripts in situ and comparison of mature and immature subsets.

We have analyzed the expression of T cell receptor (TcR) genes in the thymus using in situ RNA hybridizations with probes to the constant regions of the TcR alpha, beta, gamma and delta chains. Localization of transcripts revealed low TcR alpha mRNA levels in the thymus cortex and very low levels in the subcapsular region. In contrast, TcR beta message was very abundant in the cortex. TcR gamma or delta mRNA+ thymocytes showed a scattered, predominantly cortical localization. In contrast to gamma, TcR delta transcripts were abundant in the subcapsular region. Control experiments with sorted TcR alpha/beta or gamma/delta cells revealed a detection efficiency of 75%-85% for the respective TcR mRNA and data on TcR gene expression in mature, CD3+ thymocytes were consistent with previous reports. The analysis of immature, CD3- thymocyte subsets, however, revealed a virtual absence of TcR alpha transcripts and an unexpectedly high proportion of cells (14%-29%) expressing the gene for the TcR delta chain. The data are discussed in view of current models of lineage relationships in the thymus.

Animals↗
PubMed1990

Sequential high-dose methotrexate, 5-fluorouracil, and doxorubicin for treatment of advanced pancreatic cancer.

A phase II trial of sequential high-dose methotrexate, 1500 mg/m2, and 5-fluorouracil, 1500 mg/m2 intravenously on day 1, plus doxorubicin, 30 mg/m2 i.v. on day 14, has been undertaken in patients with locally advanced or metastatic adenocarcinoma of the pancreas. Of 25 evaluable patients there were 1 complete response and 3 partial responses for an overall response rate of 16% (95% confidence interval 5%-36%). The median survival of all patients was 6.7 months (range 1-17 months). There was one treatment-related death due to pancytopenia and sepsis. In all other patients therapy was generally well-tolerated. We conclude that this combination protocol has only modest activity in the treatment of advanced pancreatic cancer.

Adult↗
PubMed1990

Genes encoding tumor necrosis factor alpha and granzyme A are expressed during development of autoimmune diabetes.

Progressive destruction of the insulin-producing beta cells in nonobese diabetic mice is observed after infiltration of the pancreas with lymphocytes [Makino, S., Kunimoto, K., Muraoka, Y., Mizushima, Y., Katagiri, K. & Tochino, Y. (1980) Exp. Anim. (Tokyo) 29, 1-13]. We show that the genes for tumor necrosis factor alpha and granzyme A, a serine protease associated with cytoplasmic granules of cytotoxic cells, are expressed during the development of spontaneous diabetes mellitus in the nonobese diabetic mouse. Granzyme A-positive cells are found both in and surrounding the islets, implying induction prior to islet infiltration. Tumor necrosis factor alpha expression is exclusively observed in the intra-islet infiltrate, predominantly in lymphocytes adjacent to insulin-producing beta cells, the targets of the autoimmune destruction, implying that tumor necrosis factor alpha expression is induced locally--i.e., in the islet. A considerable portion of cells expressing tumor necrosis factor alpha appear to be CD4+ T cells. This T-cell subset was previously shown to be necessary for development of the disease. Thus, these findings may be important for understanding the pathogenesis of autoimmune diabetes mellitus and potentially also for that of other T-cell-mediated autoimmune diseases.

Animals↗
PubMed1990

Expression of genes encoding cytotoxic cell-associated serine proteases in thymocytes.

A family of homologous serine esterases designated granzyme A-H and the pore-forming protein perforin are present in cytoplasmic granules of mature peripheral cytolytic T lymphocytes and natural killer cells. In vivo, the majority of cytotoxic T cells containing these granule-associated proteins are of the CD4-CD8+ phenotype. It is generally assumed that these cells are derived from immature CD4-CD8- thymocytes. However, the precise intrathymic differentiation steps leading to functionally mature cytotoxic T cells are unclear. Thus we decided to analyze the expression of genes in the thymus which are preferentially expressed in mature cytotoxic cells, i.e. granzyme A, granzyme B, and perforin. In situ hybridization on tissue sections revealed the expression of genes coding for granzyme A and granzyme B in the thymus. No evidence was found, however, for thymocytes expressing the perforin gene. Granzyme A and granzyme B mRNA positive cells in the thymus are almost exclusively CD4-CD8- thymocytes, particularly of the CD3- IL2R- phenotype.

Animals↗
PubMed1990

Effects of immunoneutralization of corticotropin-releasing hormone on ultradian rhythms of plasma adrenocorticotropin.

ACTH, like other anterior pituitary peptide hormones, is secreted episodically and demonstrates both circadian and ultradian rhythms. CRH is the major regulator of ACTH release from the pituitary corticotroph. To determine the dependence of ACTH ultradian rhythms on CRH, passive immunoneutralization was used to block the activity of endogenous CRH in rats with indwelling venous catheters. Blood was sampled at 2- and 15-min intervals while blood volume was replaced. Plasma ACTH was measured by RIA. Time-series analysis of plasma ACTH concentrations was performed with PULSAR and Cluster Analysis. The 2 min data demonstrated secretory bursts approximately every 20 min. CRH immunoneutralization had no effect on the frequency of these pulses, but significantly reduced their amplitude. This was the case for raw data as well as data in which lower frequency variation had been filtered out. The 15 min data demonstrated pulsatile secretion, with a secretory episode approximately every 100 min. This lower frequency rhythm was also observed when high frequency components were filtered out of the 2 min data series. Analysis of the 15 min and the filtered 2 min time series showed this rhythm to be almost totally ablated by CRH immunoneutralization. These results suggest that CRH is responsible for amplitude modulation of an underlying CRH-independent rhythm and that through intermittent amplitude modulation of this rhythm a lower frequency rhythm is generated. Comparison between treatment groups of pulses identified by PULSAR or Cluster Analysis yielded similar results, but the programs were discordant with each other. This is the first in vivo evidence of pulsatile ACTH secretion independent of CRH, the first report demonstrating that different ultradian rhythms of ACTH may be regulated by different mechanisms, and the first comparison of PULSAR and Cluster Analysis on plasma ACTH time series.

Activity Cycles↗
PubMed1990

T-cell activation in Crohn's disease. Increased levels of soluble interleukin-2 receptor in serum and in supernatants of stimulated peripheral blood mononuclear cells.

Serum levels of soluble interleukin-2 receptor were determined in 29 patients with active and quiescent Crohn's disease. In addition, the ability of peripheral blood mononuclear cells of 23 of these patients to generate soluble interleukin-2 receptor following mitogenic stimulation was studied in vitro. Serum soluble interleukin-2 receptor concentrations of patients with active Crohn's disease (n = 19) were significantly elevated (757 +/- 438 U/ml) compared with levels in patients with inactive disease (n = 10; 412 +/- 120 U/ml) and healthy control individuals (n = 40; 375 +/- 102 U/ml; p less than 0.003 and p less than 0.0005, respectively). Serial determinations of serum soluble interleukin-2 receptor concentration in a follow-up of 11 hospitalized patients treated for highly active disease showed a decrease from 1252 +/- 494 U/ml to 527 +/- 193 U/ml (p less than 0.004) that corresponded to clinical improvement, as assessed by Crohn's disease activity index and a reduction of inflammatory parameters. In vitro phytohemagglutinin stimulation of peripheral blood mononuclear cells derived from patients with Crohn's disease resulted in elevated soluble interleukin-2 receptor production not only in patients with active disease (3987 +/- 2439 U/ml), but also in patients with inactive disease (3297 +/- 2282 U/ml), compared with the amount of soluble interleukin-2 receptor produced by mononuclear cells of healthy individuals (1523 +/- 1152 U/ml; p less than 0.005 and p less than 0.02, respectively). In addition, cultivation of mononuclear cells without mitogen resulted in higher soluble interleukin-2 receptor production in patients with active disease than in patients with inactive disease (p less than 0.02). However, patients suffering from active ulcerative colitis also had significantly increased serum levels of soluble interleukin-2 receptor (1080 +/- 400 U/ml) compared with the levels in patients with chronic disease (455 +/- 140 U/ml; p less than 0.0025). In addition, peripheral blood mononuclear cells derived from patients with ulcerative colitis produced significantly more soluble interleukin-2 receptor upon mitogenic stimulation with phytohemagglutinin (2314 +/- 936 U/ml), than cells from healthy controls (1523 +/- 1152 U/ml; p less than 0.05). The finding of elevated soluble interleukin-2 receptor serum levels in patients with active Crohn's disease and its increased production by mononuclear cells of patients with both active and inactive disease is a further example of an alteration of the immune system in this condition; however, this alteration can also be found in other inflammatory bowel diseases.

Adult↗
PubMed1989

Analysis of naturally occurring delayed-type hypersensitivity reactions in leprosy by in situ hybridization.

Analysis of tissue lesions of the major reactional states of leprosy was undertaken to study the immune mechanisms underlying regulation of cell-mediated immunity and delayed-type hypersensitivity (DTH) in man. In situ hybridization hybridization of reversal reaction biopsy specimens for INF-gamma mRNA expression revealed a 10-fold increase in specific mRNA-containing cells over that observed in unresponsive lepromatous patients. Expression of huHF serine esterase, a marker for T cytotoxic cells, were fourfold increased in reversal reaction and tuberculoid lesions above that detected in unresponsive lepromatous individuals. Immunohistology of reversal reactions confirmed a selective increase of Th and T cytotoxic cells in the cellular immune response. Of interest, the microanatomic location of these serine esterase mRNA-containing cells was identical to the distribution of CD4+ cells. Analysis of erythema nodosum leprosum (ENL) lesions revealed differences in the underlying immune processes in comparison with reversal reaction lesions. Although phenotypic Th cells predominated in ENL lesions, IFN-gamma and serine esterase gene expression were markedly reduced. We suggest that reversal reactions represent a hyperimmune DTH response characterized by a selective increase of CD4+ IFN-gamma producing cells and T cytotoxic cells, which result in the clearing of bacilli and concomitant tissue damage. In contrast, ENL reactions may be viewed as a transient diminution of Ts cells and activity leading to a partial and transient augmentation in cell-mediated immunity, perhaps sufficient to result in antibody and immune complex formation, but insufficient to clear bacilli from lesions.

Esterases↗