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G Harms

Publications and source records attributed to G Harms.

At least 19 recordsLinked to original sources
PubMed2006

Regulation of pri-microRNA BIC transcription and processing in Burkitt lymphoma.

BIC is a primary microRNA (pri-miR-155) that can be processed to mature miR-155. In this study, we show the crucial involvement of protein kinase C (PKC) and nuclear factor-kappaB (NF-kappaB) in the regulation of BIC expression upon B-cell receptor triggering. Surprisingly, Northern blot analysis did not reveal any miR-155 expression upon induction of BIC expression in the Burkitt lymphoma-derived Ramos cell line, whereas other microRNAs were clearly detectable. Ectopic expression of BIC in Ramos and HEK293 cells resulted in miR-155 expression in HEK293, but not in Ramos cells, suggesting a specific block of BIC to miR-155 processing in Ramos. In line with the results obtained with Ramos, lack of miR-155 expression after induction of BIC expression was also observed in other Burkitt lymphoma cell lines, indicating a generic and specific blockade in the processing of BIC in Burkitt lymphoma. In contrast, induction of BIC expression in normal tonsillar B cells resulted in very high levels of miR-155 expression and induction of BIC expression in Hodgkin's lymphoma cell lines. It also resulted in elevated levels of miR-155. Our data provide evidence for two levels of regulation for mature miR-155 expression: one at the transcriptional level involving PKC and NF-kappaB, and one at the processing level. Burkitt lymphoma cells not only express low levels of BIC, but also prevent processing of BIC via an, as yet, unknown mechanism.

Blotting, Northern↗
PubMed2006

Gene expression analysis of dendritic/Langerhans cells and Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is a neoplastic disorder that results in clonal proliferation of cells with a Langerhans cell (LC) phenotype. The pathogenesis of LCH is still poorly understood. In the present study, serial analysis of gene expression (SAGE) was applied to LCs generated from umbilical cord blood CD34+ progenitor cells to identify LC-specific genes and the expression of these genes in LCH was investigated. Besides the expression of several genes known to be highly expressed in LCs and LCH such as CD1a, LYZ, and CD207, high expression of genes not previously reported to be expressed in LCs, such as GSN, MMP12, CCL17, and CCL22, was also identified. Further analysis of these genes by quantitative RT-PCR revealed high expression of FSCN1 and GSN in all 12 LCH cases analysed; of CD207, MMP12, CCL22, and CD1a in the majority of these cases; and CCL17 in three of the 12 cases. Immunohistochemistry confirmed protein expression in the majority of cases. The expression of MMP12 was most abundant in multi-system LCH, which is the LCH type with the worst prognosis. This suggests that expression of MMP12 may play a role in the progression of LCH. These data reveal new insight into the pathology of LCH and provide new starting points for further investigation of this clonal proliferative disorder.

Antigens, CD↗
PubMed2005

Complement dependency of splenic localization of pneumococcal polysaccharide and conjugate vaccines.

The immune response to polysaccharides is initiated when polysaccharides bind complement factor C3d, and these polysaccharide-C3d complexes subsequently localize on splenic marginal zone B cells strongly expressing CD21 (complement receptor 2). Infants and children under the age of 2 years have low or absent expression of CD21 on their marginal zone B cells, and consequently do not adequately respond to polysaccharides. In contrast, polysaccharide-protein conjugate vaccines are able to induce antibodies at this young age. Conjugate vaccines apparently overcome the necessity for CD21-C3d interaction for an antipolysaccharide immune response. We demonstrate in a rat model that localization of pneumococcal polysaccharides on splenic marginal zone B cells indeed is complement dependent. We also show that pneumococcal conjugates do not specifically localize on splenic marginal zone B cells and that splenic localization of polysaccharide conjugates is independent of the presence of complement. Thus, the induction of antipolysaccharide antibodies by conjugate vaccines apparently can occur independently of CD21-C3d interaction. These basic findings may explain the effectiveness of conjugated vaccines in young children and may open the way for their application in other patient groups.

Animals↗
PubMed2005

High expression of Mcl-1 in ALK positive and negative anaplastic large cell lymphoma.

AIM: To gain more insight into the genes involved in the aetiology and pathogenesis of anaplastic large cell lymphoma (ALCL). METHODS: Serial analysis of gene expression (SAGE) was undertaken on the CD4+ALK+ (anaplastic lymphoma kinase positive) ALCL derived cell line Karpas299 and as comparison on CD4+ T cells. Quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were performed on five ALCL derived cell lines and 32 tissue samples to confirm the SAGE data. RESULTS: High expression of Mcl-1 was seen in the Karpas299 cell line, whereas the two other antiapoptotic Bcl-2 family members, Bcl-2 and Bcl-X(L), were not detected in the SAGE library. Quantitative RT-PCR confirmed the high expression of Mcl-1 mRNA and low expression of Bcl-2 and Bcl-X(L) in Karpas299 and in four other ALCL cell lines. To expand on these initial observations, primary tissue samples were analysed for Mcl-1, Bcl-X(L), and Bcl-2 by immunohistochemistry. All 23 ALK+ and nine ALK- ALCL cases were positive for Mcl-1. Bcl-2 and Bcl-X(L) were expressed infrequently in ALK+ ALCL cases, but were present in a higher proportion of ALK- ALCL cases. CONCLUSION: The consistent high expression of Mcl-1 in ALK+ and ALK- ALCL suggests that Mcl-1 is the main antiapoptotic protein in this disease. The high frequency of Mcl-1, Bcl-2, and Bcl-X(L) positive ALCL cases in the ALK- group compared with the ALK+ group indicates that ALK induced STAT3 activation is not the main regulatory pathway in ALCL.

Anaplastic Lymphoma Kinase↗
PubMed2003

[Progress in the early diagnosis of breast carcinoma during the years 1981-1990. Results of a longitudinal study].

BACKGROUND AND OBJECTIVE: Current meta-analyses have left in doubt whether general breast screening increases survival rate. This study investigated whether efforts at early diagnosis of cancer in the 1980s have had an effect on average tumor size at first diagnosis and on survival rate. PATIENTS AND METHODS: From 1981 to 1990, 1656 consecutive patients (average age 56.6 years) at the I. Women's Clinic at the Ludwig-Maximilian University of Munich and the Women's Clinic Berlin-Charlottenburg were operated on for primary breast cancer. In a retrospective analysis, average tumor size at the primary operation and survival rate were determined for two periods: 1981-1985 (n=849) and 1986-1990. Mean follow-up time was 63 months. RESULTS: There was no difference between the two cohorts regarding age (p = 0.77) and axillary node status (p = 0.14). During the follow-up period there was a gradual decrease in the tumor size at first diagnosis. (Pearson's correlation coefficient: -0.79, p < 0.001). Average tumor size in those operated on was 25 mm up to 1985, and 21 mm after 1986 (p < 0.001). Until 1985, the initial reason for mammography was the planned subsequent operation in 19% of patients (n = 164), and in 27% (n = 215; p < 0.001) since 1986. But there was no statistically significant rise in disease-specific survival rate (log rank, p=0.48). Multivariate analysis confirmed the conventional prognostic parameters, such as tumor size (relative risk 2.21) and axillary lymph node metastases (relative risk 3.57), but not the period of follow-up (p=0.90). CONCLUSION: During the stated periods of follow-up there was a significant decrease in average tumor size at initial diagnosis. But this did not result in any demonstrably better disease-specific survival rate.

Breast Neoplasms↗
PubMed2003

[HIV positive patient with pancytopenia and massive splenomegaly].

A 30-year-old homosexual man presented with anemia and a several months history of recurrent fever, night sweats and weakness. His travel history included several stays in mediterranean countries during the recent years. Abdominal ultrasound showed massive splenomegaly, hepatomegaly and abdominal lymphadenopathy. A bone marrow aspirate revealed the presence of numerous Leishmania amastigotes, and bone marrow culture and polymerase chain reaction were also positive for Leishmania. In this case report epidemiological, immunological, diagnostic and therapeutic aspects of HIV-Leishmania coinfection are discussed with special emphasis on the impact of liposomal amphotericin B and highly active antiretroviral therapy on the treatment of HIV-leishmania-coinfection.

AIDS-Related Opportunistic Infections↗
PubMed2003

Molecular assessment of ammonia- and nitrite-oxidizing bacteria in full-scale activated sludge wastewater treatment plants.

Nitrification was assessed in two full-scale wastewater treatment plants (WWTPs) over time using molecular methods. Both WWTPs employed a complete-mix suspended growth, aerobic activated sludge process (with biomass recycle) for combined carbon and nitrogen treatment. However, one facility treated primarily municipal wastewater while the other only industrial wastewater. Real time PCR assays were developed to determine copy numbers for total 16S rDNA (a measure of biomass content), the amoA gene (a measure of ammonia-oxidizers), and the Nitrospira 16S rDNA gene (a measure of nitrite-oxidizers) in mixed liquor samples. In both the municipal and industrial WWTP samples, total 16S rDNA values were approximately 2-9 x 10(13) copies/L and Nitrospira 16S rDNA values were 2-4 x 10(10) copies/L. amoA gene concentrations averaged 1.73 x 10(9) copies/L (municipal) and 1.06 x 10(10) copies/L (industrial), however, assays for two distinct ammonia oxidizing bacteria were required.

Ammonia↗
PubMed2002

Epidemiology and clinical features of imported dengue fever in Europe: sentinel surveillance data from TropNetEurop.

Travelers have the potential both to acquire and to spread dengue virus infection. The incidence of dengue fever (DF) among European travelers certainly is underestimated, because few centers use standardized diagnostic procedures for febrile patients. In addition, DF is currently not reported in most European public health systems. Surveillance has commenced within the framework of a European Network on Imported Infectious Disease Surveillance (TropNetEurop) to gain information on the quantity and severity of cases of dengue imported into Europe. Descriptions of 294 patients with DF were analyzed for epidemiological information and clinical features. By far the most infections were imported from Asia, which suggests a high risk of DF for travelers to that region. Dengue hemorrhagic fever occurred in 7 patients (2.4%) all of whom recovered. Data reported by member sites of the TropNetEurop can contribute to understanding the epidemiology and clinical characteristics of imported DF.

Adolescent↗
PubMed2002

[Infections and diseases after travelling].

BACKGROUND AND OBJECTIVE: With intensifying international travel numbers of travel associated infections and diseases will increase. Systematic studies on infections and diseases with regard to the travel destination in tropical and subtropical areas are scarce in Germany. PATIENTS AND METHODS: Data regarding travel destination, reason, type and duration of travel, symptoms, clinical findings, laboratory results as well as diagnoses of 2024 patients (male 1010, mean age 35 years; female 1014, mean age 33 years) presenting at the outpatient clinic of the Institute of Tropical Medicine Berlin after returning from travel to tropical or subtropical areas were assessed. RESULTS: The most frequent reasons for consultation were diarrhea (33 %), fever (17 %) and skin affections (14 %). A definitive diagnosis was established in 31 % (635). Significant differences were found for prevalences of infectious diseases with regard to travel destinations. 1.5 % of the travellers had contracted malaria. Only 34% of the returnees from malaria-endemic areas had taken chemoprophylaxis; in case of travel to Africa and Asia, chemoprophyplaxis corresponded to international standards in only 48 % and 23%, respectively. Giardia lamblia was the most frequently detected intestinal pathogen. Blastocystis hominis was found to be significantly associated with diarrhea. CONCLUSIONS: Most of the travel-associated infections are self-limited. In case of fever, malaria and potentially hemorrhagic fever should be excluded and be followed by a stepwise investigation on the cause of fever. In case of diarrhea, parasitologic investigations should be performed by an experienced laboratory and fresh stool samples should be used. Intensive co-operation will be necessary between physician, pharmacists and others active in the field of travel medicine in order to address the shortcomings in chemoprophylaxis for malaria. An increasing need for expertise in tropical and travel medicine, especially among private physicians is expected.

Adult↗
PubMed2002

Imported Falciparum malaria in Europe: sentinel surveillance data from the European network on surveillance of imported infectious diseases.

Malaria continues to have a high morbidity rate associated among European travelers. Thorough recording of epidemiological and clinical aspects of imported malaria has been helpful in the detection of new outbreaks and areas of developing drug resistance. Sentinel surveillance of data collected prospectively since 1999 has begun within TropNetEurop, a European network focusing on imported infectious diseases. TropNetEurop appears to cover approximately 10% of all patients with malaria seen in Europe. Reports of 1659 immigrants and European patients with Plasmodium falciparum malaria were analyzed for epidemiological information and data on clinical features. Regional data were quite diverse, reflecting local patterns of immigration and international travel. By far, the most infections were imported from West Africa. Europeans had more clinical complications; consequently, all deaths occurred in this group. Compared with European standards, the mortality rate was low (0.6% in Europeans). Data from TropNetEurop member sites can contribute to our understanding of the epidemiological and clinical findings regarding imported falciparum malaria.

Adolescent↗
PubMed2002

Analysis of in vivo endothelial cell activation applying RT-PCR following endothelial cell isolation by laser dissection microscopy.

Laser dissection microscopy was applied to isolate endothelial cells from tumors obtained from mice treated with TNF-alpha. RNA integrity was demonstrated from whole sections and dissected cells after acetone fixation and hematoxylin staining. RT-PCR for GAPDH, CD31, VCAM-1, ICAM-1, and E-selectin was successfully performed on these samples. These data demonstrate the feasibility of analyzing local endothelial cell responses in diseased tissues at the level of gene expression.

Animals↗
PubMed2001

Identification of nucleolin as a new L-selectin ligand.

Apart from leucocyte-endothelial interactions, the adhesion molecule L-selectin mediates the homotypic adhesion of leucocytes during recruitment at sites of acute inflammation, as well as intercellular adhesion of haematopoietic progenitor cells during haematopoiesis. There is evidence that, in addition to P-selectin glycoprotein ligand-1, other as-yet-unidentified proteins function as L-selectin ligands on human leucocytes and haematopoietic progenitor cells. In the present study, we show: (i) by affinity chromatography on L-selectin-agarose; (ii) by protein identification using MS; and (iii) by covalent cell-surface labelling with sulphosuccinimidyl-2-(biotinamido)ethyl-1,3-dithiopropionate that the multifunctional nuclear protein nucleolin is partly exposed on the cell surface, and is a ligand of L-selectin in human leucocytes and haematopoietic progenitor cells.

Amino Acid Sequence↗
PubMed2001

Localized lymphadenopathy due to leishmanial infection.

A 25-year-old female patient presented with an isolated cervical lymph node enlargement several months after having returned from Spain and Latin America. She had no other signs or symptoms of disease. Leishmania infantum/chagasi was identified as the causative agent. With extended travel activities localized lymph node enlargement due to leishmanial infection should be included in the differential diagnosis of lymphadenopathy of unknown origin.

Adult↗
PubMed2001

Evaluation of a dipstick test for the rapid diagnosis of imported malaria among patients presenting within the network TropNetEurop.

Lack of experience on the part of involved laboratory personnel frequently complicates swift diagnosis of imported falciparum malaria in non-endemic areas. Diagnostic tools based on the dipstick principle for the detection of plasmodial histidine-rich protein 2 have been marketed for several years and have been extensively evaluated. Recently, a test kit capable of detecting antigen of Plasmodium falciparum and P. vivax has been introduced. In order to evaluate this newly available tool, specimens from 664 patients were screened during the course of a prospective multicentre study within the European Network on Imported Infectious Disease Surveillance (TropNetEurop). Among the screened specimens, samples from 82 patients (12.3%) were positive for falciparum malaria using expert microscopy. A further 17 samples were positive for vivax malaria. The evaluated test kit performed with a sensitivity of 87.8% and a specificity of 99% for detection of falciparum malaria. Respective values for vivax malaria were 76.5% and 100%. Dipstick tests have the potential of improving the speed and accuracy of the diagnosis of falciparum malaria, especially if non-specialized laboratories are involved. However, decreased values of sensitivity and specificity, in comparison with expert microscopy, still impose a clear limit on the usefulness of the currently available kits.

Antibodies, Protozoan↗
PubMed1999

Anaerobic oxidation of the aromatic plant hydrocarbon p-cymene by newly isolated denitrifying bacteria.

The capability of nitrate-reducing bacteria to degrade alkyltoluenes in the absence of molecular oxygen was investigated with the three isomers of xylene, ethyltoluene, and isopropyltoluene (cymene) in enrichment cultures inoculated with freshwater mud. Denitrifying enrichment cultures developed most readily (within 4 weeks) with p-cymene, a natural aromatic hydrocarbon occurring in plants, and with m-xylene (within 6 weeks). Enrichment of denitrifiers that utilized m-ethyltoluene and p-ethyltoluene was slow (within 8 and 12 weeks, respectively); no enrichment cultures were obtained with the other alkylbenzenes within 6 months. Anaerobic degradation of p-cymene, which has not been reported before, was studied in more detail. Two new types of denitrifying bacteria with oval cells, strains pCyN1 and pCyN2, were isolated; they grew on p-cymene (diluted in an inert carrier phase) and nitrate with doubling times of 12 and 16 h, respectively. Strain pCyN1, but not strain pCyN2, also utilized p-ethyltoluene and toluene. Both strains grew with some alkenoic monoterpenes structurally related to p-cymene, e.g., alpha-terpinene. In addition, the isolates utilized p-isopropylbenzoate, and mono- and dicarboxylic aliphatic acids. Determination of the degradation balance of p-cymene and growth with acetate and nitrate indicated the capacity for complete oxidation of organic substrates under anoxic conditions. Adaptation studies with cells of strain pCyN1 suggest the existence of at least two enzyme systems for anaerobic alkylbenzene utilization, one metabolizing p-cymene and p-ethyltoluene, and the other metabolizing toluene. Excretion of p-isopropylbenzoate during growth on p-cymene indicated that the methyl group is the site of initial enzymatic attack. Although both strains were facultatively aerobic, as revealed by growth on acetate under air, growth on p-cymene under oxic conditions was observed only with strain pCyN1. Strains pCyN1 and pCyN2 are closely related to members of the Azoarcus-Thauera cluster within the beta-subclass of the Proteobacteria, as revealed by 16S rRNA gene sequence analysis. This cluster encompasses several described denitrifiers that oxidize toluene and other alkylbenzenes.

Anaerobiosis↗
PubMed1999

Spleen autotransplantation provides restoration of functional splenic lymphoid compartments and improves the humoral immune response to pneumococcal polysaccharide vaccine.

After splenectomy, patients have an increased risk of overwhelming post-splenectomy infection (OPSI) or sepsis involving encapsulated bacteria such as pneumococcus. The value of spleen autotransplantation after splenectomy because of trauma has long been questioned. Much attention has been given to the restoration of mononuclear phagocyte system (MPS) function, which appeared to be similar to that of splenectomized individuals. The presence of specific anti-pneumococcal antibodies may enhance phagocytosis of opsonized bacteria by other parts of the MPS, as present in the liver. Therefore, in the present study we have evaluated the restoration of the humoral immune response after spleen autotransplantation, especially to pneumococcal capsular polysaccharides (PPS). Wistar rats were divided into three groups which were operated as follows: splenectomy, splenectomy followed by autotransplantation, and sham operation. After 12 weeks the rats were vaccinated with 23-valent pneumococcal vaccine. Blood samples were taken after 3 days, 3 and 6 weeks for anti-PPS IgM and IgG ELISA against types 3, 4, 6, 9, 14 and 23. In addition, immunohistological studies were performed on the autotransplants. Significant antibody titre rises were found in a main proportion of the autotransplanted rats, comparable to sham-operated rats. Splenectomized rats showed as well a significantly lower increase in immunoglobulin levels, as significant differences in the proportion of rats showing a minimum two-fold increase of antibody level, considered to represent an adequate response. The titres were highest 3 days after vaccination. Immunohistochemical studies demonstrated structurally functional autotransplants, including an intact marginal zone. Considering this significant anti- pneumococcal antibody response, spleen autotransplants can be expected to enable an improved humoral response to PPS, and to contribute to protection against OPSI after splenectomy.

Animals↗