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K Dittmar

Publications and source records attributed to K Dittmar.

At least 19 recordsLinked to original sources
PubMed2004

Paleoparasitological analysis of coprolites from K2, an Iron Age archaeological site in South Africa: the first finding of Dicrocoelium sp. eggs.

Until now, Dicrocoelium sp. eggs have only been recorded from European and 1 North American archaeological sites. We present evidence for the first record of Dicrocoelium sp. from an African archaeological site. A paleoparasitological study was conducted on 7 coprolite samples from K2, a Late Iron Age site on the farm Greefswald, in the Northern Province of South Africa. Standard parasitological analysis revealed the presence of Dicrocoelium sp. and Trichuris sp. eggs. Today, the parasite does not occur in this region. Trichurid eggs are a relatively common find in paleoparasitological analysis. The presence of Dicrocoelium sp. provides new clues about the antiquity of this parasite, as well as aspects of ancient environment, climate, and interactions among humans, animals, and parasites.

Animals↗
PubMed2003

Techniques of DNA-studies on prehispanic ectoparasites (Pulex sp., Pulicidae, Siphonaptera) from Animal mummies of the Chiribaya culture, southern Peru.

During a paleoparasitological survey of several animal mummies (Cavia aperea f. porcellus and Canis familiaris) from Chiribaya Baja, an archaeological site in Southern Peru, an unexpected find was made. In the well preserved fur, large numbers of mummified fleas (Pulex simulans/irritans) that parasitized the animals during life were encountered. Due to the relative recent event of the host mummification and the outstanding preservation of the fleas, an attempt for the retrieval of DNA was made. A DNA extraction and sequencing protocol for archaeological ectoparasitic remains has been established, taking additional studies for tissue and protein preservation into account. Tissue preservation was assessed with transmission electron microscopy and the protein preservation was tested through the racemisation ratios of aspartic acid. Regions of the 28S rDNA gene were successfully amplified and sequenced. Further research perspectives are outlined.

Animals↗
PubMed2003

The presence of Fasciola hepatica (liver-fluke) in humans and cattle from a 4,500 year old archaeological site in the Saale-Unstrut valley, Germany.

During an excavation of a site of the corded ware culture in the Saale-Unstrut-Valley (ca. 3000 BC) in Germany, a soil sample from the pelvis of a human skeleton was studied under palaeoparasitological aspects. Eggs of the trematode Fasciola hepatica and of the nematode genus Capillaria were found. This is the first case of a direct association of a F. hepatica-infestation to both a prehistoric human skeleton and domesticated animal remains. Sheep and cattle bones were present at the same site and F. hepatica eggs were found in bovine samples. This strongly points toward an existing infection cycle, involving humans as a final host.

Animals↗
PubMed2003

Assessment of the relative number of copies of the gene encoding human neutrophil antigen-2a(HNA-2a), CD177, and a homologous pseudogene by quantitative real-time PCR.

Human neutrophil antigen-2a (HNA-2a; NB1) is located on the 58-64 kD NB1 glycoprotein (GP) and is encoded by the gene CD177. Searches of human genome databases have revealed that a pseudogene highly homologous to exons 4-9 of CD177 is located adjacent to CD177 on chromosome 19. The purpose of this study was to document the presence of the pseudogene and determine whether the polymorphic expression of NB1 GP is due to CD177 gene deletions and duplications. Genomic DNA was isolated from leukocytes of 12 subjects. The number of copies of exon 2 of CD177, an exon that is unique to this gene, and the number of copies of exon 9, an exon that is found in both CD177 and the pseudogene, was assessed with quantitative real-time PCR. The ratio of the number of copies of sequences homologous to CD177 exon 9 to the number of copies of exon 2 was 1.5 or greater in 7 of the 12 subjects, suggesting that both CD177 and the homologous pseudogene were present. The ratio of exon 9 to exon 2 in the other 5 subjects ranged from 1 to 1.25, suggesting that the pseudogene was not present in these subjects. However, results of assays were variable and we could not exclude the possibility that all subjects carried the pseudogene. These studies confirmed the presence of the pseudogene homologous to CD177, but quantitative real-time PCR was not precise enough to detect CD177 duplications or deletions.

Journal Article↗
PubMed2002

Crab louse infestation in pre-Columbian America.

Until now, Pthirus pubis infestation in ancient human populations had only been recorded in the Old World. We found crab lice on South American mummified bodies from the Atacama Desert region. Crab louse eggs were found attached to the pubic hairs of a 2,000-yr-old Chilean mummy. Well-preserved adults were found in sediment and clothing from a Peruvian mummy dated 1,000 yr ago. Paleoparasitological evidence expands the knowledge of the distribution of this ectoparasite in ancient populations. As with many other parasites, pubic lice recorded in Andean populations show the antiquity of this parasite in the New World. It is likely that P. pubis entered the continent with early human migration to the New World.

Animals↗
PubMed2001

Comparison of DATs using traditional tube agglutination to gel column and affinity column procedures.

BACKGROUND: Detection of immunoglobulin or complement bound to RBCs by using the DAT is valuable in the diagnosis of immune-mediated hemolytic anemia. Traditionally, the DAT has been performed by tube agglutination using anti-IgG or anti-C3d. The purpose of this study was to compare the tube agglutination DAT to gel microcolumn, affinity microcolumn, and flow cytometric DATs on RBCs coated in vitro and on patient RBC samples. STUDY DESIGN AND METHODS: RBCs from 84 patients were assessed by tube agglutination DAT, one gel microcolumn DAT, and two affinity microcolumn DATs. One affinity microcolumn assay was unmodified and one was modified by the addition of polyspecific antiglobulin or anti-IgG as a secondary antibody. RBCs from 15 of the 84 patients underwent analysis by flow cytometry with fluorescence-labeled anti-IgG. The assays were also compared by using D+ RBCs sensitized with serially adjusted concentrations of anti-D. RESULTS: Both tube agglutination and gel microcolumn DATs were positive in 49 patient samples; both assays were negative in 20 samples, and the results were discordant in 15. Gel microcolumn DATs were more likely than were tube agglutination DATs to detect IgG on RBCs. Affinity microcolumn DATs were less likely than gel microcolumn or tube agglutination DATs to detect IgG on RBCs. Flow cytometry results were the same as gel microcolumn results in 12 of 15 patient samples and the same as tube agglutination results in 13 of 15. Tube agglutination and both affinity microcolumn assays reacted with RBCs coated with anti-D that was diluted 1-in-100. The gel microcolumn and flow cytometry assays reacted with RBCs coated with anti-D diluted 1-in-400. There was no correlation between tube agglutination and gel microcolumn DATs in detecting bound C3d. CONCLUSION: Detection of IgG bound to RBCs was not consistent with the methods described. Gel microcolumn DATs were more sensitive than tube agglutination and affinity microcolumn DATs. Given the varied results of these assays, reference laboratories should not rely on a single method for DATs. More comprehensive testing should be performed when the tube agglutination DAT is negative in a patient with suspected immune-mediated hemolytic anemia. Further comparisons are necessary to determine the proficiency of flow cytometric assays.

Agglutination Tests↗
PubMed1999

Ig V gene mutation status and CD38 expression as novel prognostic indicators in chronic lymphocytic leukemia.

Cellular immunophenotypic studies were performed on a cohort of randomly selected IgM(+) B-chronic lymphocytic leukemia (B-CLL) cases for which Ig V(H) and V(L) gene sequences were available. The cases were categorized based on V gene mutation status and CD38 expression and analyzed for treatment history and survival. The B-CLL cases could be divided into 2 groups. Those patients with unmutated V genes displayed higher percentages of CD38(+) B-CLL cells (>/=30%) than those with mutated V genes that had lower percentages of CD38(+) cells (<30%). Patients in both the unmutated and the >/=30% CD38(+) groups responded poorly to continuous multiregimen chemotherapy (including fludarabine) and had shorter survival. In contrast, the mutated and the <30% CD38(+) groups required minimal or no chemotherapy and had prolonged survival. These observations were true also for those patients who stratified to the Rai intermediate risk category. In the mutated and the <30% CD38(+) groups, males and females were virtually equally distributed, whereas in the unmutated and the >/=30% CD38(+) groups, a marked male predominance was found. Thus, Ig V gene mutation status and the percentages of CD38(+) B-CLL cells appear to be accurate predictors of clinical outcome in B-CLL patients. These parameters, especially CD38 expression that can be analyzed conveniently in most clinical laboratories, should be valuable adjuncts to the present staging systems for predicting the clinical course in individual B-CLL cases. Future evaluations of new therapeutic strategies and drugs should take into account the different natural histories of patients categorized in these manners.

Antigens, CD↗
PubMed1999

Cytoplasmic localization of the trypanothione peroxidase system in Crithidia fasciculata.

Tryparedoxin I (TXNI) and tryparedoxin peroxidase (TXNPx), novel proteins isolated from Crithidia fasciculata, have been reported to reconstitute a trypanothione peroxidase activity in vitro (Nogoceke, E.; Gommel, D. U.; Kiess, M.; Kalisz, H. M.; Flohé, L. Biol. Chem. 378:827-836; 1997). Combined with trypanothione reductase, they may form an NADPH-fueled trypanothione-mediated defense system against hydroperoxides in the trypanosomatids. In situ confocal microscopy of antibody-stained TXNI and TXNPx and electron microscopy of the immunogold labeled proteins revealed their colocalization in the cytosol. Insignificant amounts of the enzymes were detected in the nucleus and vesicular structures, whereas the kinetoplast and the mitochondrion are virtually free of any label. Comparison of the PCR product sequences obtained with genomic and cDNA templates rules out any editing typical of kinetoplast mRNA. Sequence similarities with any of the established maxicircle genes of trypanosomatids were not detectable. It is concluded that both, TXNI as well as TXNPx are encoded by nuclear DNA and predominantly, if not exclusively localized in the cytosol. Working in concert with trypanothione reductase, they can function as an enzymatic system that reduces hydroperoxides at the expense of NADPH without any impairment of the flux of reduction equivalents by cellular compartmentation.

Animals↗
PubMed1996

Examples of in vivo isotype class switching in IgM+ chronic lymphocytic leukemia B cells.

Chronic lymphocytic leukemia (CLL) usually involves the expansion of a clone of CD5+ B cells synthesizing IgM antibodies. These B cells appear to be blocked at the antigen receptor-expressing stage of B cell differentiation and are thought not to undergo an isotype class switch to IgG or IgA production. In vivo and in vitro studies suggest, however, that in some instances terminal differentiation and isotype switching can occur. To test the hypothesis that in vivo isotype class switching occurs in IgM+ B-type CLL cells, we analyzed the PBMC of 19 CLL patients for the presence of transcripts encoding the rearranged CLL V(H)DJ(H) associated with either gamma or alpha H chains. The molecular data indicate that approximately 50% of B-CLL patients have amplifications of IgM+ B cells that undergo an isotype class switch. Switching to IgA appears to occur more often than to IgG; also, switching can involve different IgG subclasses in individual patients. In many instances, these CLL-related gamma and alpha transcripts are much more plentiful than those of normal B cells that produce the same isotype. These switched transcripts do not reveal evidence for the accumulation of significant numbers of new V(H) gene mutations. The cellular data indicate that B cells with lesser amounts of surface membrane IgD and higher IgM/IgD ratios are more likely to undergo this switching process. Furthermore, B cells expressing IgG and IgA of the same idiotype or V(H) family and the same CDR3 length as those of the CLL IgM+ clone can be identified in the blood of patients studied using multiparameter immunofluorescence analyses. Collectively, these data suggest that not all members of a B-CLL clone are frozen at the surface membrane Ig-expressing stage of B cell maturation, and that some members can switch to the production of non-IgM isotypes. The occurrence of switching without the accumulation of V gene mutations indicates that the processes of differentiation and diversification are not linked.

Adult↗
PubMed1996

Relationship between hairy cell leukemia variant and splenic lymphoma with villous lymphocytes: presentation of a new concept.

An unusual case of low-grade B-cell lymphoproliferative disorder with peripheral lymphocytosis and splenomegaly followed for 4 1/2 years is reported. During this period, the phenotype of the tumor cells in the blood changed from that of hairy cell leukemia (HCL)/chronic lymphocyte leukemia (CLL) to HCL/prolymphocytic leukemia (PLL), to PLL. The lymphoid population in the blood showed a mixture of hairy cells, villous lymphocytes, small lymphocytes, and prolymphocytes, corresponding to the phenotypes at various stages. Although relatively specific markers for CLL, HCL, and PLL, such as CD5, CD11c, CD22, CD25, and FMC-7, were positive at various stages, all these markers have also been demonstrated in a large study series of splenic lymphoma with villous lymphocytes (SLVL). In addition, the histologic pattern of the bone marrow biopsy and splenectomy specimen were not typical for HCL. This case can therefore be classified either as HCL variant or as SLVL. As SLVL assumes various cytologic and histologic patterns, which overlap with different lymphoproliferative disorders, especially HCL variants, this entity appears to represent a heterogeneous group of lymphomas/leukemias that may evolve into each other. The absence of activation of c-myc and bc1-2 oncogenes as well as mutation of p53 tumor suppressor gene, together with the presence of only one single rearranged band for both heavy chain and kappa light chain genes in our case suggest that these morphologically different lymphoid tumors may belong to the same family.

Antigens, CD↗
PubMed1995

Spot synthesis of overlapping peptides on paper membrane supports enables the identification of linear monoclonal antibody binding determinants on morbillivirus phosphoproteins.

In order to map antigenic domains on the P-protein of morbillivirus, a series of overlapping peptides, representing the P-protein sequences of phocid distemper virus strain 2558/Han88 and canine distemper virus strain Onderstepoort, were synthesized on a paper support by the spot-technique. The reactivity of six monoclonal antibodies with the peptides was tested in an enzyme immunoassay and compared to their reactivity in Western blots and in an ELISA using detergent extracts from virus-infected cells. Three linear determinants could be localized on the P-protein. Two antibody-binding sites were delineated within the C-terminal (between amino acids 307-322 and 382-400, respectively), and a third one was located on the N-terminal part (amino acids 13-31) of the protein. Fine mapping of this binding site revealed that this was a part of an antigenic domain. In Western blots, the monoclonal antibodies reacting with this domain also reacted with a second protein which was possibly the V-protein.

Amino Acid Sequence↗
PubMed1994

Splenic lymphoma with circulating villous lymphocytes: report of seven cases and review of the literature.

Splenic lymphoma with villous lymphocytes (SLVL) is a relatively new entity with only a few reports published. We report seven cases of SLVL with detailed clinicopathologic and comprehensive immunophenotypic studies to further characterize this lymphoma, which is frequently confused with hairy cell leukemia and other low-grade B-cell lymphoid neoplasms. The diagnostic criteria we used include 1) prominent splenomegaly, 2) insignificant or no lymphadenopathy, 3) lymphocytosis without leukopenia, 4) presence of circulating villous lymphocytes, 5) characteristic cytologic and histologic features, and 6) specific phenotypic and cytochemical findings. Our studies show that SLVL does not represent a pure entity but rather a morphologically heterogeneous group of low-grade lymphomas with various cytologic and histologic features. Although immunophenotyping is helpful in differential diagnosis, multiparameter studies are necessary to confirm the diagnosis. In our series, only two patients died of SLVL, who probably developed transformation to a higher-grade lymphoma.

Aged↗
PubMed1993

RNA insertions and gene duplications in the nonstructural protein p125 region of pestivirus strains and isolates in vitro and in vivo.

Sixteen cytopathogenic (cp) bovine viral diarrhea virus (BVDV) strains/isolates were screened for the existence of RNA insertions in the p125 gene region and/or for p80 gene duplications using the polymerase chain reaction after reverse transcription. Three strains/isolates were shown to contain insertions, and in three others gene duplications were demonstrated. One strain was shown to contain a gene duplication in addition to an insertion. Insertions or duplications were absent in the genomes of 10 non-cp BVD virus strains/isolates, in 4 hog cholera (HC) virus strains, and in 9 of the 16 cp BVD virus strains/isolates analyzed. These results indicate that RNA insertions and gene duplications, although significant, are not the only mechanism contributing to cytopathogenicity in vitro. The RT-PCR was also applied to RNA isolated from tissues of a calf suffering from mucosal disease. Insertion-containing amplification products could be demonstrated in an organ-specific pattern.

Animals↗
PubMed1992

Phenotyping and genotyping of composite lymphoma with Ki-1 component.

A case of composite lymphoma consisting of an anaplastic large-cell Ki-1 lymphoma and a small-cell follicular lymphoma was found in the splenic hilar lymph node of a 66-year-old woman. The Ki-1 lymphoma showed monoclonal IgM-lambda and CD 20, CD 74, and CDw 75 antigens by immunostaining and CD 19, CD 20, CD 22, and lambda antigens by flow cytometry. The follicular lymphoma also showed monoclonal IgM-lambda, and CD 20 and CDw 75 antigens but not CD 74 and CD 30 (Ki-1) by immunostaining. Flow cytometric analysis of the follicular lymphoma component was not conclusive, as it was impossible to separate the neoplastic from the normal small B lymphocytes. Ki-1 lymphoma usually is seen in childhood and is mostly of T cell origin. It is, therefore, unusual to find Ki-1 antigen component in a composite lymphoma of B-cell origin in an adult. However, there has been evidence to suggest that B-cell Ki-1 lymphoma may be related to follicular lymphoma. Thus, our case may represent a follicular lymphoma transforming into a Ki-1 lymphoma. Immunogenotyping in this case revealed that the two components were probably of the same clonal origin, as they seemed to share the same light chain gene. The presence of rearrangement in the switch region of the IgH in our case without the actual occurrence of heavy chain switching may have triggered somatic recombination in the IgH complex. This series of events may have led to the transformation of a low-grade lymphoma into a high-grade lymphoma, accounting for the two morphologic patterns seen in our bimorphic lymphoma.

Aged↗
PubMed1991

Extramedullary blast crisis in chronic myelogenous leukemia. Demonstration of T-cell lineage and Philadelphia chromosome in a paraspinal tumor.

A case of chronic myelogenous leukemia (CML) with penetrance of the Ph1 molecular alteration into the T-cell lineage of a paraspinal tumor is reported. The T-cell nature of the paraspinal tumor was documented by immunochemical study and genotyping. The Philadelphia chromosome was also detected by genotyping in the same tumor cell population. To the authors' knowledge, this is the first case of extramedullary T-cell blast crisis in CML demonstrated in an extranodal tumor. The clinical significance of detecting extramedullary blast crisis, and the theories for the scarcity of T-cell transformation in CML are discussed.

Blast Crisis↗