Increased numbers of cytokeratin-positive interstitial reticulum cells (CIRC) in reactive,inflammatory and neoplastic lymphadenopathies: hyperplasia or induced expression?

A total of 291 enlarged lymph nodes showing a range of reactive-inflammatory processes, primary and metastatic neoplasms were studied to determine the distribution and immunoprofile of their cytokeratin-positive interstitial reticulum cells (CIRC) in comparison with normal nodes. In 258/291 nodes (89%), CIRC numbers were distinctly increased in the subcapsular, paracortical and, occasionally, in the medullary zones; often, these increased CIRC formed networks around follicles, sinuses and vessels. CIRC had comparatively small, irregularly shaped bodies and dendritic processes; occasionally, giant forms were noted. CIRC contained cytokeratins (CK) 8 and 18 but not 19, as shown by immunohistochemistry, and by gel electrophoresis with subsequent immunoblotting. They co-expressed vimentin consistently, alpha-smooth-muscle actin frequently, and desmin less frequently. They did not contain desmoplakins, Factor VIII, S-100, LCA, B and T lymphocyte- and macrophage-associated antigens, chromogranin A, synaptophysin or the A-80 glycoprotein. We found no clear correlation between the increased CIRC and given nodal disease processes. However, CIRC were most abundant in nodes free of but draining malignant tumours; bizarre CIRC assemblies were noted in HIV lymphadenopathy. CIRC appear to represent a subset of the so-called fibroblastic reticulum cells of lymph nodes. Their function remains undetermined; their increase in diverse lymphadenopathies suggests that they partake in nodal reactions to injury. It remains unclear whether the increase in CIRC relative number is due to proliferation or to CK gene induction processes but their presence and potential capability to undergo hyperplasia with dysplastic forms should alert pathologists to possible diagnostic pitfalls. In addition, we discuss that CIRC may undergo transformation and represent the cell of origin of certain CK-positive tumours restricted to lymph nodes.     

Synaptophysin: A reliable marker for medulloblastomas

Summary Synaptophysin is an acidic, integral membrane glycoprotein (M_r 38000) of presynaptic vesicles in various neurons and neuroendocrine cells, and in tumours derived from such cells. By indirect immunofluorescence microscopy of cryostat sections, using the monoclonal antibody SY 38 to synaptophysin, a consistent positive immunoreactivity was observed in all medulloblastomas (n= 6) and neuroblastomas (n=3) as well as a ganglioneuroma and a glioneuronal hamartoma. The presence of synaptophysin in medulloblastomas was confirmed biochemically by immunoblotting experiments. For purpose of comparison, the expression of intermediate-sized filament (IF) proteins was also examined. While neurofilament proteins were consistently expressed in the neuroblastomas (3/3), the ganglioneuroma and the glioneuronal hamartoma, IF distribution in medulloblastomas was variable. A neurofilament-positive type of tumour (1/6) could be distinguished from vimentin-expressing neoplasms (4/6) by immunocytochemistry. These data indicate that synaptophysin is a reliable marker for medulloblastomas as well as other differentiated and undifferentiated neuronal tumours and in this respect is superior to the more heterogeneous expression patterns of IF proteins in these tumours.     

Primitive neuroectodermal tumors of the central nervous system. Patterns of expression of neuroendocrine markers, and all classes of intermediate filament proteins

Snap-frozen samples from 22 primitive neuroectodermal tumors (PNETs) primary in the central nervous system were studied with antibodies to synaptophysin, bombesin, somatostatin, substance P, vasoactive intestinal polypeptide, all classes of intermediate filaments, and desmoplakins I and II. Frozen sections were immunostained by the avidin-biotin peroxidase complex and indirect immunofluorescence microscopy methods. Selected cases were also studied by double and triple label immunofluorescence microscopy, and by two-dimensional gel electrophoresis and immunoblot analysis. We found that all 22 PNETs expressed synaptophysin extensively. Focal expression of 2 or more neuropeptides was noted in 10 samples studied. All PNETs expressed vimentin, 21 of 22 expressed glial filament protein (GFP), 16 of 22 expressed neurofilament proteins (NFP), 4 of 22 expressed desmin, and 3 of 22 expressed cytokeratins. In only one case were focal and questionable reactions with desmoplakin antibodies seen. Immunoblots confirmed the presence of desmin. Double and triple immunofluorescence revealed a number of antigenic coexpressions in individual cells including: synaptophysin with vimentin, GFP, NFP and desmin, vimentin-GFP, vimentin-NFP, vimentin-cytokeratin, vimentin-desmin and desmin-NFP; similarly, combinations of vimentin-GFP-NFP, vimentin-GFP-desmin, and vimentin-GFP-cytokeratin were found. The consistent expression of synaptophysin and 2 or more neuropeptides indicates that central nervous system PNETs have significant phenotypic features in common with neuroendocrine tumors. Their complex and variable intermediate filament complement patterns combined with their consistent expression of specific neuroendocrine differentiation markers, suggest that central nervous system PNETs comprise a distinct, albeit heterogeneous group of neoplasms.     

Vergleichende Untersuchung von niedermolekularem Dextranoder Hydroxyäthylstärkelösungen als Volumenersatzmittel bei Hämodilutionstherapie

Summary Rheological therapy, as an immediate treatment in conjunction with physical therapy and the removal of risc factors, plays a significant role in the management of patients with peripheral vascular disease experiencing reduced walking tolerance. An essential element of rheological therapy is hemodilution. Currently, is still uncertain which plasma substitute solution would be the most appropriate in such cases. This study compared the effectiveness of low molecular hydroxyethyl starch to low molecular dextran during a 16-day hemodilution in combination to physical therapy. The clinical improvement observed with both plasma substitute solutions was comparable, yet in view of the cardiac volume overload, dextran demonstrates greater circulatory stress due to the transient pressure increase and more side effects. For this reason, we prefer to administer low or middle molecular hydroxyethyl starch in the dilution treatment of peripheral arterial occlusive disease as a chronic degenerative vascular disease.

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Abkürzungen A2M Alpha-2-Makroglobulin - D0 Meßzeitpunkt 0 der später mit Dextran behandelten Gruppe - D1 Meßzeitpunkt 1 der Dextran-Gruppe - D2 Meßzeitpunkt 2 der Dextran-Gruppe - Dextran 40 kleinmolekulares Dextran (mittleres Molekulargewicht 40000 Dalton) - ETA Plasmaviskosität - Fib Fibrinogen - Geh Gehstrecke - H0 Meßzeitpunkt 0 der später mit Hydroxyäthylstärke behandelten Gruppe - H1 Meßzeitpunkt 1 der HAES-Gruppe - H2 Meßzeitpunkt 2 der HAES-Gruppe - HAES 40 kleinmolekulare Hydroxyäthylstärke (mittleres Molekulargewicht 40000 Dalton) - Hkt Hämatokrit - LZ Leukozyten-Zahl - Pro Gesamteiweiß - SEA Erythrozyten-Aggregationsindex - SER Erythrozyten-Rigiditätsindex - TY Fließschubspannung - TZ Thrombozyten-Zahl     

Cytokeratins in normal and malignant transitional epithelium. Maintenance of expression of urothelial differentiation features in transitional cell carcinomas and bladder carcinoma cell culture lines.

The pattern of cytokeratins expressed in normal urothelium has been compared with that of various forms of transitional cell carcinomas (TCCs; 21 cases) and cultured bladder carcinoma cell lines, using immunolocalization and gel electrophoretic techniques. In normal urothelium, all simple-epithelium-type cytokeratins (polypeptides 7, 8, 18, 19) were detected in all cell layers, whereas antibodies to cytokeratins typical for stratified epithelia reacted with certain basal cells only or, in the case of cytokeratin 13, with cells of the basal and intermediate layers. This pattern was essentially maintained in low-grade (G1, G1/2) TCCs but was remarkably modified in G2 TCCs. In G3 TCCs simple-epithelial cytokeratins were predominant whereas the amounts of component 13 were greatly reduced. Squamous metaplasia was accompanied generally by increased or new expression of some stratified-epithelial cytokeratins. The cytokeratin patterns of cell culture lines RT-112 and RT-4 resembled those of G1 and G2 TCCs, whereas cell line T-24 was comparable to G3 carcinomas. The cell line EJ showed a markedly different pattern. The results indicate that, in the cell layers of the urothelium, the synthesis of stratification-related cytokeratins such as component 13 is inversely oriented compared with that in other stratified epithelia where these proteins are suprabasally expressed, that TCCs retain certain intrinsic cytoskeletal features of urothelium, and that different TCCs can be distinguished by their cytokeratin patterns. The potential value of these observations in histopathologic and cytologic diagnoses is discussed.     

Damaged chromatin does not prevent the exit from metaphase I in fused mouse oocytes

The presence of checkpoint mechanisms which are able to recognize damaged chromatin and thereafter to prevent exit from metaphase I has been investigated in giant mouse oocytes produced by fusion of a normal metaphase I oocyte with an equivalent oocyte with damaged chromatin. The presence of damaged chromatin did not prevent the onset of anaphase I in both sets of chromatin in the fused cells. Interestingly, fused or unfused cells containing only damaged chromatin failed to enter anaphase and persisted instead in a metaphase-like state. These results demonstrate the fragility of checkpoint controls in mammalian female germ cells.      

Respiratory effects in two-dimensional Fourier transform MR imaging

Respiratory and other regular motions during two-dimensional Fourier transform magnetic resonance imaging produce image artifacts consisting of local blurring and more or less regularly spaced "ghost" images propagating along the direction of the phase-encoding magnetic field gradient. The patterns of these ghost artifacts can be understood in terms of the technique of image production and basic properties of the discrete Fourier transform. This understanding permits, without respiratory gating, production of images of improved quality in body regions in which there is significant respiratory motion. In particular, the ghosts can be maximally separated from the primary image by choosing intervals between phase-encoding gradient pulse increments that are equal to one-half the respiratory period; they can be minimally separated by choosing an interval equal to the respiratory period. Increasing the number of signal averages between each phase-encoding increment decreases the intensity of the ghosts.     

End products and enzyme levels of aerobic glucose fermentation in trypanosomatids

Trypanosoma cruzi (epimastigotes), Crithidia fasciculata and Leishmania mexicana (promastigotes) were grown in a brain-heart-tryptose medium supplemented with heat-inactivated fetal calf serum. T. cruzi and C. fasciculata utilized glucose completely during the log phase of growth, whereas L. mexicana used significant amounts of the carbohydrate only at the end of the log phase and at the beginning of the stationary phase. In all cases glucose consumption resulted in excretion of succinate, and much smaller amounts of acetate. C. fasciculata and L. mexicana produced very small amounts of pyruvate. C. fasciculata produced ethanol, which was taken up again and metabolysed after glucose was exhausted. Lactate and malate were not produced. The cells were disrupted by sonic disintegration, and the activities of some key enzymes of carbohydrate and amino acid catabolism were assayed in the whole homogenates. Phosphoenolpyruvate carboxykinase was present in the three organisms; L. mexicana presented the highest specific activity. The activity of this enzyme was maximal during glucose consumption, and slightly decreased after glucose was exhausted. This suggests that the role played by the enzyme is glycolytic and not gluconeogenic; the latter is the case in most higher organisms. Hexokinase and pyruvate kinase presented their highest levels in C. fasciculata and T. cruzi during glucose consumption. L. mexicana, which was in active glycolysis during the whole experimental period, presented the highest specific activities of both enzymes. Citrate synthase, on the other hand, increased in C. fasciculata and, to a lesser extent, in T. cruzi, after glucose was exhausted; the enzyme could not be detected in L. mexicana. The NAD-linked glutamate dehydrogenase increased considerably in C. fasciculata and T. cruzi after glucose was exhausted, suggesting a catabolic role for the enzyme. This increase coincided with an increase in NH3 production by both organisms after glucose consumption. The NADP-linked glutamate dehydrogenase, on the other hand, presented a maximum about the time when glucose was exhausted, and then decreased again, which suggests a catabolic role for the enzyme. Both glutamate dehydrogenases had low activities in L. mexicana; this fits in well with the low NH3 production throughout the culture of this organism. The results are in good agreement with current ideas on the mechanism of aerobic glucose fermentation by trypanosomatids, and suggest that, under the experimental conditions used, both T. cruzi and C. fasciculata used glucose perferentially over amino acids for growth.