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G Harms

Publications and source records attributed to G Harms.

At least 55 records · Page 3Linked to original sources
PubMed1992

Immunopathology of alkaline phosphatase-induced granulomatous hepatitis in rats.

Granulomatous inflammation is a specific type of chronic inflammation in which macrophages and T-cell-mediated immunity to the inciting agent play a pivotal role. In the present study, granulomatous hepatitis was induced in rats by the administration of a single intravenous dose of porcine intestinal alkaline phosphatase. The cellular composition of the hepatic granulomas was analyzed in-situ with a number of recently developed mouse anti-rat monoclonal antibodies to cells of the monocyte-macrophage lineage and lymphocyte subsets. Well-developed granulomas consisted of aggregates of macrophages with central modification into epithelioid cells, a peripheral rim of T- and B-lymphoid cells, including considerable numbers of immunoblasts and plasma cells. In addition, the periphery of the granulomas contained many fat storing cells, a sinusoidal cell type thought to play a central role in hepatic fibrosis. Moreover, intense immunostaining for the extracellular matrix proteins fibronectin and collagen type III was observed at the periphery of the lesions. The granulomas persisted for long periods without eliciting liver cirrhosis. Alkaline phosphatase induced hepatic granulomas in the rat may help to elucidate the contribution of cells of the B-lineage to chronic granulomatous inflammation.

Adipose Tissue↗
PubMed1991

Formaldehyde treated albumin contains monomeric and polymeric forms that are differently cleared by endothelial and Kupffer cells of the liver: evidence for scavenger receptor heterogeneity.

Formaldehyde treated albumin (F-HSA) was found to consist of a monomeric and a polymeric fraction. Both fractions were primarily endocytosed by rat liver sinusoidal cells. However, immunohistochemical staining of endocytosed material showed that the relative contribution of the endothelial and Kupffer cells in uptake of the monomer and the polymer differed significantly, with the monomer mainly having an endothelial cell- and the polymer predominantly having a Kupffer cell pattern of distribution. To directly confirm these heterogeneous patterns, we injected in vivo the 125I-labeled F-HSA fractions and isolated the endothelial and Kupffer cells by centrifugal elutriation. 73.7% of the monomeric F-HSA was found in endothelial cells and only 14.9% was found in Kupffer cells. In contrast, the polymeric F-HSA (1500 kD) was mainly endocytosed by Kupffer cells (71%), whereas the endothelial cells contributed only for 24% in hepatic uptake. In vivo studies and isolated perfused rat liver experiments showed that endocytosis of both monomer and polymer was inhibited by co-administration of polyinosinic acid, a well known inhibitor for scavenger receptors, indicating that these receptors on endothelial and Kupffer cells are mainly involved in this uptake process.

Animals↗
PubMed1991

Hepatic endocytosis of various types of mannose-terminated albumins. What is important, sugar recognition, net charge, or the combination of these features.

We synthesized several para-aminophenyl (pap-) mannose-terminated albumins with varying sugar density (Man7-HSA, Man22-HSA, and Man40-HSA) and compared hepatic uptake with (thio-)mannose-terminated bovine serum albumin (Man-43-AI-BSA) The rate of uptake in isolated perfused rat livers was found to be positively correlated with the sugar density (Man40-HSA = Man22-HSA greater than Man7-HSA greater than HSA). Immunohistochemical staining of liver sections showed for both types of neoglycoproteins that uptake occurred in nonparenchymal cells only. Competition experiments with a 500-fold excess of mannan, a known ligand for the mannose/N-acetylglucosamine receptor, that is predominantly localized in endothelial cells, showed complete inhibition of the (thio-)Man43-AI-BSA uptake. In the case of (pap-)mannose-terminated albumins, however, the extent of inhibition by mannan was moderate and decreased markedly with increasing sugar density, being only 20% for (pap-)Man40-HSA. Therefore, we hypothesized that one or more additional removal systems contributed to the clearance of these (pap-)mannose glycoproteins. We found that net negative charge of the (pap-)mannose albumins clearly increased with increasing sugar density, as shown on fast protein liquid chromatography anion-exchange chromatograms. To determine whether the scavenger receptor system that is also mainly present on endothelial cells is involved, we performed competition studies with strongly negatively charged substrates, such as dextran sulfate and formaldehyde-treated human serum albumin (fHSA). An excess of dextran sulfate (500 kDa), indeed blocked the (pap-)mannose-albumin uptake for more than 95%. Dextran sulfate completely inhibited the hepatic uptake of mannan as well, indicating that the polyanion does not discriminate between the scavenger system and the mannose receptor system and should be regarded as an aspecific inhibitor of receptor-mediated endocytotic pathways. Surprisingly, a 500-fold excess of fHSA only moderately (20%) inhibited the clearance of (pap-)Man40-HSA in spite of its high affinity for the scavenger receptor. However, a combination of mannan and fHSA strongly inhibited the uptake of (pap-)Man22-HSA (90%) and to a lesser extent (pap-)Man40-HSA (80%), indicating that a third uptake mechanism may exist that recognizes both mannose groups (or other sugars) and net negative charge. This so far unnoticed receptor system apparently is strongly affected by dextran sulfate and, as shown by immunohistochemistry, is mainly localized on Kupffer cells rather than on the endothelial cells of the liver.

Albumins↗
PubMed1991

Interferon-gamma treatment in mice experimentally infected with Trichinella spiralis.

Interferon-tau (IFN-tau) treatment of Trichinella spiralis-infected BALB/c mice was investigated. The therapeutic regimen consisted of daily intraperitoneal injection of 10(4) U murine IFN-tau for 7 days, starting at 2 weeks post-infection. Striated muscle samples (diaphragm, thigh) were collected at 4, 8 and 12 weeks after infection. The muscle larval burden, the degree of encystation and the digestion of T. spiralis larvae were investigated. Furthermore, immunohistochemical studies of the inflammatory cell infiltrate around encysted larvae were performed. The results demonstrated an influence of IFN-tau treatment on the CD4+ and CD8+ subset distribution during the immune response but revealed no difference in the degree of encystation or digestion of encapsulated larvae as compared with control values.

Animals↗
PubMed1991

Generation of cytokines in human visceral leishmaniasis: dissociation of endogenous TNF-alpha and IL-1 beta production.

The role of TNF-alpha in visceral leishmaniasis is ambivalent, the eventual outcome of this infection, cure or generalization, being determined by the relative amounts of cytokines produced in vivo. Since release, by monocytes/macrophages, of TNF-alpha and interleukins 1 beta (IL-1 beta) and IL-6 is important in both the induction and effector phases of the immune responses, these mediators were determined in sera and cell culture supernatants of seventeen L. donovani infected patients in Brazil. The results are compared to those of a local control group. Circulating immunoreactive TNF-alpha in patients (median, 140 pg ml-1) was increased ten-fold over controls (median 16 pg ml-1, p less than or equal to 0.0001). In contrast, serum IL-1 beta was less than 20 pg ml-1 in all patients, although detectable in sera of 3/16 Brazilian controls (chi 2 = 3.5, p less than 0.1). Mitogen induced in vitro release of IL-1 beta and IL-6 by patients' circulating mononuclear cells was significantly reduced, and the capacity of patients' peripheral monocytes for H2O2 generation in response to opsonized zymosan was significantly diminished. In the patients, serum TNF-alpha levels were inversely related to IL-1 beta release in vitro (rho = -0.57, p less than or equal to 0.01).

Adolescent↗
PubMed1990

Glycosyl receptors in macrophage subpopulations of rat spleen and lymph node. A comparative study using neoglycoproteins and monoclonal antibodies ED1, ED2 and ED3.

We have developed an immunohistochemical method for the in vivo and in vitro detection of glycosyl receptors in rat spleen and lymph nodes by using neoglycoproteins. The receptor in both organs recognized mannose coupled to bovine serum albumin (mannose-BSA), fucose-BSA, N-acetylglucosamine-BSA and to a lesser extent glucose-BSA, but not galactose-BSA or N-acetyl-galactosamine-BSA. In vitro neoglycoprotein-receptor binding was Ca2+ dependent and could be inhibited by mannan but not by mannose. Simultaneous staining with the monoclonal antibodies ED1, ED2 or ED3 revealed that only ED1- and ED3-positive macrophages were involved in the binding of neoglycoproteins. In the spleen, the marginal-zone macrophages and a subpopulation of the marginal metallophils possess glycosyl-binding receptors. In the lymph nodes, the medullary sinus macrophages and a subpopulation of the outer-cortex macrophages are able to bind neoglycoproteins.

Animals↗
PubMed1990

Determinants of the immune response in visceral leishmaniasis: evidence for predominance of endogenous interleukin 4 over interferon-gamma production.

Accumulating evidence points toward an antagonism between TH1 and TH2 focused immune responses decisive for the outcome of parasitic infections with leishmaniae. Interferon-gamma (IFN-gamma) and interleukin 4 (IL4), the principal cytokines involved in these pathways, as well as IgE and the IgG subclasses differentially modulated by these cytokines, were therefore assessed in 18 Brazilian patients with visceral leishmaniasis. The results are compared to those of a local control group. IL4 was detected in all patient sera but in only one control. Low concentrations of IFN-gamma where detectable in 50% of the Brazilian controls but in only two patients. While group medians of mitogen-induced in vitro synthesis of IL4 and IFN-gamma were similar, release of these lymphokines correlated inversely in patients (Spearman's rho = -0.84). Elevations of serum IgE complement the lymphokine data to indicate prominent TH2 type responses in clinical infections with Leishmania donovani.

Adolescent↗
PubMed1990

Re-infection in human schistosomiasis mansoni: a prospective field study 18 months after praziquantel therapy.

Twenty-eight Zairean patients with Schistosoma mansoni infection were investigated and treated with praziquantel. Of these, 22 were re-examined 18 months later and 13 were found to be re-infected. Eighteen uninfected Zaireans were monitored concurrently to control for variations unrelated to schistosomiasis. Pathophysiological changes related to liver fibrosis were assessed by the determination of serum cholylglycine and procollagen-III-peptide. Circulating T-cell subsets were quantitated, and shedded T-cell antigens were measured in sera. In patients initially presenting with hepatomegaly, the biochemical indicators for egg-induced immunopathology became normal after therapy and remained normal even after re-infection, when the parasite load attained about 50% of the pretreatment level. Among T-cell phenotypes, CD4+ cells transiently increased by three months after treatment, but after 18 months the CD4/CD8 ratios both in patients then re-infected and in those not re-infected had reverted to the respective balances which had been observed at the start of the investigation. Both soluble CD8 antigen and interleukin 2 receptor in patients' sera were significantly elevated throughout the study period. The results indicate a dissociation of factors regulating fibrogenesis and immunomodulation after treatment and re-infected.

Adolescent↗
PubMed1990

Proliferation rate of colonic mucosa in normal subjects and patients with colonic neoplasms: a refined immunohistochemical method.

An increased colonic epithelial proliferation rate and an increase of the cryptal proliferative zone are probable markers of increased susceptibility to colonic cancer. In this study an immunohistochemical method using 5-bromo-deoxyuridine (BrdUrd) to measure the proliferation rate of colonic mucosa in vitro was used. Fresh endoscopic colonic biopsy specimens were incubated with BrdUrd and then processed for immunohistochemistry using a monoclonal antibody. Essential procedures with respect to the equal distribution of nuclei stained with BrdUrd in the biopsy specimens proved to be the cutting of the specimens before incubation and the use of a microwave oven at the beginning of incubation. The use of the procedure of the running average showed that 12 length cut crypts are sufficient to determine reliably the proliferation rate, expressed as the labelling index (LI). This was determined in the biopsy specimens of 10 subjects without organic colonic disease, eight patients with adenomatous colonic polyps, and in six patients with (recent) colonic carcinoma. Mean LI in the controls was significantly lower than in patients with colonic polyps and in those with colon cancer. It is concluded that this method is promising for screening persons at risk for colon cancer and will be of great potential in performing dietary intervention studies in these subjects.

Adolescent↗
PubMed1989

Effects of intradermal gamma-interferon in cutaneous leishmaniasis.

The clinical and immunological evolution of lesions in cutaneous leishmaniasis was assessed after treatment with human recombinant gamma interferon (rIFN-gamma). 3 weeks after rIFN-gamma treatment of lesions due to Leishmania braziliensis guyanensis, 12/13 had become smaller compared with 6/13 control lesions; only 4 treated lesions were free of parasites. 9 of 13 L tropica lesions treated with rIFN-gamma resolved completely within 4-8 weeks of treatment. An acute inflammatory reaction around treated lesions was more common in lesions due to L tropica. There were no other local or systemic adverse reactions. Histological and immunohistochemical studies indicate that local application of rIFN-gamma enhances cell-mediated immune responses and thus promotes healing of cutaneous leishmaniasis.

Acute Disease↗
PubMed1989

T cell phenotype alterations in hepatosplenic schistosomiasis mansoni normalize after chemotherapy.

Peripheral blood T cell phenotypes, CD3-induced mitogenesis and soluble IL 2 receptor and CD8 in sera were studied in intestinal and hepatosplenic Schistosomiasis mansoni before and three to six months after therapy with praziquantel. Fifteen pairs matched for intensity of infection were analyzed and compared with local, non-infected age-matched controls. CD3+ cell counts were lower in untreated hepatosplenic schistosomiasis (median 1040 cells/microliters; 95% confidence interval 608-1269) compared to controls (1534; 1264-1620). This difference was largely accounted for by immature CD1+/CD3-cells circulating in these patients (median 388/microliters, 252-474). The frequency of CD1+ T cells in circulation decreased drastically after chemotherapy. Similar, but less marked, alterations were seen in intestinal schistosomiasis. Lymphocyte proliferation initiated by agonistic anti-CD3 monoclonal antibody was severely impaired in hepatosplenic patients, who had suffered haemorrhagic complications, but not in the cases of incipient hepatomegaly. Soluble CD8 antigen circulated in increased amounts in hepatosplenic schistosomiasis. Remarkably, a negative correlation between CD3-induced mitogenesis and circulating levels of CD8 was noted in these patients. Whereas CD3-induced mitogenesis in hepatosplenic schistosomiasis normalized after therapy, circulating IL 2R and CD8 antigen in hepatosplenic patients still exceeded control levels. The results demonstrate disturbances of CD3 and CD8 expression and/or T cell maturation in hepatosplenic schistosomiasis. Imbalanced CD4/CD8 ratios and an increased IL 2R/CD8 turnover may reflect an inhibitory circuit within the T cell compartment.

Adolescent↗
PubMed1989

Specific demonstration of ribonucleic acid by chemical bromination and immunohistochemistry.

In this report we describe a specific staining procedure for detection of ribonucleic acid (RNA), based on bromination of uracil and subsequent immunohistochemical visualization of 5-bromouracil in RNA. This method is applicable for both cryostat and glycol methacrylate (GMA)-embedded sections. Cryostat sections must be fixed in formaldehyde, whereas tissue pieces to be embedded in GMA are fixed in cold acetone. Before bromination, sections must be treated with trypsin. Bromination was performed in a solution of bromine in potassium bromide. After bromination, excess bromine was removed with sodium bisulfite. The monoclonal antibody MoBu-1 specifically bound to brominated RNA. Ribonuclease digestion, in contrast to deoxyribonuclease digestion, abolished staining. This method makes possible precise localization of RNA, especially well demonstrated in plastic-embedded sections.

Animals↗
PubMed1988

Immunohistochemical antigen demonstration in plastic-embedded lymphoid tissue.

We describe a method for post-embedding immunohistochemical demonstration of a wide range of antigens in glycol methacrylate-embedded tissue. Rat spleen and thymus tissues were fixed by immersion in fixatives containing different concentrations of paraformaldehyde, washed in sucrose phosphate buffer, dehydrated in acetone, infiltrated in a glycol methacrylate mixture in which the commonly used softener 2-butoxyethanol was replaced by butaandiol monoacrylate, and embedded. Trypsin was used to re-expose the masked antigenicity. Excellent results were obtained with a panel of monoclonal antibodies (MoAbs) directed against T-cells, B-cells, Ia-positive cells, macrophages, follicular dendritic cells, and leucocyte common antigen-bearing cells. The method described combines exact localization of antigens with optimal tissue morphology.

Acrylates↗
PubMed1988

Liver involvement in human schistosomiasis mansoni. Regression of immunological and biochemical disease markers after specific treatment.

Peripheral blood cholyglycine and procollagen-III-peptide were measured in 22 Zairean patients with hepatomegaly caused by S. mansoni before and after treatment with praziquantel. Circulating T-cell subsets and cutaneous in vivo delayed type hypersensitivity were assessed; serum neopterin and beta 2-microglobulin served as indicators for macrophage/lymphocyte activation. The results were compared to age and sex matched patients with S. mansoni infection limited to the intestinal tract and schistosomiasis free controls with equal socioeconomic background. Abnormal serum cholyglycine and neopterin levels and alterations of circulating T-cell subset frequencies were associated with hepatomegaly in schistosomiasis. Normalization of these parameters reflected a regression of egg-induced immunopathology as early as two months after specific chemotherapy. Serum procollagen-III-peptide concentrations rose significantly after treatment, suggesting release of propeptide previously incorporated without cleavage into tissue collagen. The combination of these biochemical and immunological parameters may allow assessment of the pathophysiological mechanisms responsible for liver disease in individual patients.

Adolescent↗
PubMed1988

[The use of UV rays for the disinfection of water. I. Microbiologic studies of drinking water].

As a physical disinfection method without chemicals required the ultraviolet irradiation was tested for disinfection of drinking water. The survival was measured as a function of exposure to radiation for S. enteritidis, E. cloacae, C. freundii, S. marcescens, E. coli, K. pneumoniae und S. faecium. The bacteria were grown in trypton soya broth until they were well into the exponential phase. Two different UV-disinfection units were tested. Both consist of cylindrical shaped chambers with one low-pressure mercury-discharge lamp with their longitudinal axis parallel to the chambers. With 10(6) cfu/ml the experiments were done with three different rates of flow of 7,2 m3/h, 4,0 m3/h and 2,0 m3/h. The minimum exposures to radiation necessary to cause a 99.999% reduction were 10-86 mWs/cm2 depending on the test bacterium and on the UV-disinfection unit. The minimum doses ranged for S. enteritidis up to 13 mWs/cm2, for E. coli up to 21 mWs/cm2, for K. pneumoniae up to 39 mWs/cm2, for S. faecium up to 42 mWs/cm2, for E. cloacae up to 43 mWs/cm2, for C. freundii up to 72 mWs/cm2, and for S. marcescens up to 86 mWs/cm2.

Bacteria↗
PubMed1988

Interleukin 2 receptor in patients with localized and systemic parasitic diseases.

An enzyme-linked immunosorbent assay was used to quantify soluble interleukin 2 receptor (IL-2R) in the serum of patients with helminthic and protozoal infections. The results demonstrated that levels of IL-2R were normal in patients with helminthic infections limited to the intestinal tract (ascariasis, trichuriasis), but significantly elevated in patients with systemic or long-lasting infections (strongyloidiasis, schistosomiasis, fascioliasis, opisthorchiasis). In patients infected with Schistosoma mansoni levels of IL-2R were higher in those with the hepatosplenic than in those with the intestinal form of the disease. Patients with malaria also showed increased serum levels of IL-2R, irrespective whether the infection was caused by Plasmodium falciparum or P. vivax. No difference was observed between patients with acute or history of malaria. The highest levels of IL-2R were observed in patients with visceral leishmaniasis. Interestingly, in these patients the concentration of IL-2R correlated to specific antibody titre. The results are discussed in the context of preferential activation of T lymphocytes, B lymphocytes and/or macrophages during the course of the different parasitic infections investigated.

Enzyme-Linked Immunosorbent Assay↗
PubMed1988

Double immunohistochemical demonstration of antigen expression and DNA-incorporated 5-bromodeoxyuridine in frozen and plastic embedded sections.

In this study a double immunohistochemical staining procedure is described for the simultaneous visualization of antigen expressing cells and replicating cells. Cell surface antigen expression was marked with a monoclonal antibody against I a (His 19) or a monoclonal antibody against a membrane component of the cells of the monocyte-macrophage lineage (ED2). Replicating cells were detected by the incorporation of 5-bromodeoxyuridine. The method was applied sequentially. On frozen sections two peroxidase labeled reagents were used with two different substrates yielding a red and a dark-blue black reaction product. On plastic-embedded sections a peroxidase and an alkaline phosphatase labeled reagent were applied resulting in a brown and a blue reaction product.

Animals↗