G-Trisomie bei akuter Erythroleukämie

Zusammenfassung Es wird über einen Fall akuter Erythroleukämie mit G-Trisomie berichtet und die mögliche Bedeutung hereditärer Faktoren für die Manifestation akuter Leukämien diskutiert.

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Summary The cytogenetic analyses of direct bone marrow preparations in a 53 years old male with acute erythroleukaemia of 9 months disease history, revealed persistently a G-trisomy in a dominant cell line with 47 chromosomes. The peripheral blood culture preparations with phytohaemagglutinin exhibited normal diploid cell line.The frequent occurrence of akute leukaemia in Down's syndrome tempts to implicate that leukaemia with G-Trisomy having no signs of Down's syndrome is a somatic mutation initiated by some unknown hereditary recessive genes mechanisms.

     

Removal of the circumsporozoite protein (CSP) glycosylphosphatidylinositol signal sequence from a CSP DNA vaccine enhances induction of CSP-specific Th2 type immune responses and improvesprotection against malaria infection

The C terminus of the circumsporozoite protein (CSP) is anchored to the parasite cell membrane by a glycosylphosphatidylinositol (GPI) glycolipid. This GPI signal sequence functions poorly in heterologous eukaryotic cells, causing CSP retention within internal cell organelles during genetic immunization. Cellular location of antigen has quantitative and qualitative effects on immune responses induced by genetic immunization. Removal of the GPI signal sequence had a profound effect on induction and efficacy of CSP-specific immune response after genetic immunization of BALB/c mice with a gene gun. The CSP produced from the plasmid lacking the GPI anchor signal sequence (CSP-A) was secreted and soluble, but that produced by the CSP+A plasmid was not. The CSP-A plasmid induced a highly polarized Th2 type response, in which the CSP-specific IgG antibody titer was three- to fourfold higher, and the protective effect was significantly greater than that induced by the CSP+A plasmid. Thus, these two physical forms of CSP induced quantitatively and qualitatively different immune responses that also differed in protective efficacy. Engineering plasmid constructs for proper cellular localization of gene products is a primary consideration for the preparation of optimally efficacious DNA vaccines.     

nm23-H1 suppresses invasion of oral squamous cell carcinoma-derived cell lines without modifying matrix metalloproteinase-2 and matrix metalloproteinase-9 expression

nm23-H1 is a candidate gene for the suppression of cancer metastasis. Several studies on human breast, hepatocellular, gastric, ovarian, and colon carcinomas and melanomas have shown that reduced nm23-H1 expression was closely related to metastatic progression with poor prognosis. However, the biochemical mechanism by which nm23-H1 suppresses the metastasis has yet to be elucidated. In this study, we analyzed the correlation between nm23 expression, cell motility, and the invasive abilities of six different oral squamous cell carcinoma cell lines (HSC2, HSC3, HSC4, KB, OSC19, and OSC20). Reduced mRNA/protein expression of the nm23-H1 was observed in three cell lines (HSC2, HSC3, and HSC4). These cell lines exhibited increased cell motility and an invasive character on organotypic raft culture. On the other hand, the cell lines (KB, OSC19, and OSC20) that showed a higher expression of nm23-H1 exhibited a threefold to fivefold reduced motility and also reflected fewer invasions compared to the former three cell lines. Because the HSC3 cells demonstrated the lowest nm23-H1 expression with the highest cell motility and invasive character, we established nm23-H1-transfected HSC3 cell lines to investigate whether exogenous nm23-H1 protein could inhibit cell migration and invasive activity. These transfectants showed a significant reduction in cell motility with exogenous nm23-H1 in a dose-dependent manner, and exhibited a noninvasive character. An immunofluorescence study demonstrated a distinct stress-fiber distribution at peripheral region of these transfectants. However, no significant difference of matrix metalloproteinase (MMP)-2 and MMP-9 expression was observed between mock transfectant and nm23-H1-transfected cells. These findings suggest that nm23-H1 inhibits the invasive activity of oral squamous cell carcinoma by suppression of cell motility without altering the MMP-2 and MMP-9 status.     

Adrenal pseudocysts: Evidence of their posthemorrhagic nature

Hemorrhagic adrenal pseudocysts are uncommon nonneoplastic lesions that have been reported as secondary to intraparenchymal hemorrhage or alternatively related to endothelial (vascular) cysts. Ultrastructural and immunohistochemical evidence in support of the latter has been presented, but the exact nature of hemorrhagic adrenal pseudocysts remains poorly defined. We evaluated six surgical specimens of hemorrhagic adrenal pseudocysts using immunohistochemical staining for CD31 and CD34, as well as conventional histochemistry. All six cases had hemorrhagic contents within a wall of variable thickness possessing focal areas of linear, disrupted elastin, and smooth muscle. Three cases demonstrated extensive thrombosis with organization, including papillary endothelial hyperplasia, simulating angiosarcoma. In these cases, CD31 and CD34 staining decorated areas of papillary endothelial hyperplasia as well as foci of the internal cyst lining, whereas the other cases were negative for both antibodies. Of interest is the history of FNA prior to surgical resection in three cases of hemorrhagic adrenal pseudocysts, two of which showed papillary endothelial hyperplasia. The presence of papillary endothelial hyperplasia and our immunohistochemical findings support, the conclusion that adrenal pseudocysts are posthemorrhagic and derive from vascular disruption. Furthermore, FNA or other interventional studies may be associated with papillary endothelial hyperplasia in hemorrhagic adrenal pseudocysts.     

Emblica officinalis Gaertn and serum cholesterol level in experimental rabbits.

Twelve albino rabbits of either sex weighing 1.0-1.25 kg were fed a standard laboratory diet of green grass and sattu (roasted Bengal gram). After a 2-week run-in period their serum cholesterol levels were estimated. All animals were now fed 0.5 g cholesterol and 1.0 g clarified butter daily and were not divided into 3 groups of 4 animals each. While all received the standard cholesterol-rich diet, Group A animals received no additional substances, animals in Group B were each fed 10 mg vitamin C daily, while those in Group C were each given 1.0 g fresh Amla (Emblica officinalis Gaertn). Mean serum cholesterol levels in all three groups rose to significantly higher levels by the end of the second week. There was a further rise by the end of the third and fourth weeks in Groups A and B. However, animals in Group C (i.e. those given Amla) showed significantly lower mean serum cholesterol levels at the end of the second week than their counterparts in Groups A and B. At the end of the third and fourth weeks the differences were even more pronounced.     

Serious complications of vascular catheter-relatedStaphylococcus aureus bacteremia in cancer patients

Over the period 1986 to 1989, 53 cancer patients were identified with catheter-relatedStaphylococcus aureus bacteremia at the University of Texas M.D. Anderson Cancer Center. Septic thrombosis was diagnosed in 12 (23 %) patients and was suspected in another 3 (6 %). Of the 12 patients, five developed deep-seated infections (septic emboli, endocarditis, meningitis, abscess), compared with 2 of the 38 other patients with no septic thrombosis (p<0.01). Fever persisted for more than three days after antibiotic initiation in 52 % of the patients with complications (septic thrombosis and/or deep-seated infections), compared with 19 % of those without complications (p<0.02). Of the three patients with complications who were treated for 14 days with intravenous antistaphylococcal antibiotics, two relapsed; in contrast, all of the nine patients with complications who were treated for more than 14 days (mean 4 weeks) were cured, and none relapsed (p<0.05). Of the nine patients with complications who were treated with a long course of therapy, only one required surgery. The possibility of septic thrombosis and/or deep-seated infections should be considered in all cancer patients with catheter-relatedStaphylococcus aureus bacteremia, and if present, the condition should be treated with appropriate intravenous antibiotics for at least four weeks.     

Molecular characterization of a complex translocation in a newborn infant

A newborn infant was referred because of low-set ears, mild downward slant of the palpebral fissues, micrognathia with higharched palate, a flat midface, small mouth, and thin upper lip with cupid bow configuration. To some extent her cry resembled that associated with cri du chat syndrome. Cytogenetic findings with G- and Q-banding alone failed to characterize precisely the complex translocations. By the chromosome in situ suppression (CISS) hybridization technique using whole chromosome specific probes, a complex 4 breakpoint rearrangement involving both arms of a single chromosome 1 with the long arms of chromosome 5 and 11 was disclosed, i.e., 46,XX, der(1),t(1;5) t(1;11) (5qter→5q31::1p31.3→1q44::11q23→11qter;5pter→5q31::1p31.3→1pter;11pter→11q23::1q44→1qter). Gene deregulation and position effect may explain the multiple anomalies in individuals with apparently balanced translocations may shed some light towards unveiling the clinical consequences associated with aberrations which are presumably balanced. © 1993 Wiley-Liss, Inc.     

Distinct types of T-cell help for the induction of a humoral immune response to Streptococcus pneumoniae

Studies have indicated that purified soluble polysaccharide antigens can elicit T cell-independent Ig responses in vivo, although these responses can be modulated by T cells in a noncognate manner. Relatively little is known, however, concerning the parameters that regulate polysaccharide-specific, as well as protein-specific, Ig isotype responses to an intact extracellular bacterium. Using the murine in vivo humoral response to intact Streptococcus pneumoniae as a model it can be shown that CD4+ T-cell receptor alphabeta+ T cells deliver help for both polysaccharide- and protein-specific Ig responses. However, these responses differ fundamentally in their mechanism of action.     

Ultrastructural comparison between regenerating and developing hindlimbs of Xenopus laevis tadpoles

Hindlimbs of Xenopus laevis tadpoles at stages 50 to 55 of embryonic development were amputated in order to study the fine structure associated with ontogenetic decline in regenerative ability of this anuran. Regenerating hindlimbs were compared with their contralateral developing limb so as to determine the similarities and differences in ectodermal-mesenchymal ultrastructural relationships in these systems. Prior to stage 53, mesenchymal cells in regenerating limbs, as well as mesenchyme cells in developing limbs appear undifferentiated; the cells are not visibly different. However, at stage 54 muscle and cartilage differentiation in the developing foot is distinct. Furthermore, in all larvae with regenerates at stages 50 to 52 the basal lamina is not evident subjacent to the apical tip of the epithelium which covers the amputation surface. A distinct basal lamina is present, however, beneath the epidermis in all embryonic limbs examined, including the apical tip, as well as in regenerates of stages 53 to 55 tadpoles. Also, a greater apical accumulation of extracellular matrix (ECM) and organized collagen is observed among the mesenchymal cells in regenerates of stages 53 to 55 tadpoles, and among the mesenchyme cells in developing limbs of stages 50 to 55, compared with pre-stage 53 regenerates. In cases in which an embryonic limb bud is composed of relatively undifferentiated cells (stages 50 to 52), events following amputation result in the complete regeneration of a limb. However, when amputated embryonic limbs contain differentiating tissues, (e.g., muscle and cartilage) only selective tissues undergo regeneration resulting in malformed (heteromorphic) regenerates.(ABSTRACT TRUNCATED AT 250 WORDS)