Cyclin D1 overexpression in multiple myeloma. A morphologic, immunohistochemical, and in situ hybridization study of 71 paraffin-embedded bone marrow biopsy specimens.

Cyclin D1 expression was evaluated by immunohistochemical analysis and biotin-labeled in situ hybridization (ISH) in a series of 71 decalcified, paraffin-embedded bone marrow biopsy specimens from patients with multiple myeloma (MM). Cyclin D1 messenger RNA (mRNA) overexpression was detected by ISH in 23 (32%) of 71 cases, whereas cyclin D1 protein was identified by immunohistochemical analysis in 17 (24%) of 71 specimens. All cases that were positive by immunohistochemical analysis also were positive by ISH. Statistically significant associations were found between cyclin D1 overexpression and grade of plasma cell differentiation and between cyclin D1 overexpression and extent of bone marrow infiltration. Our findings demonstrate the following: (1) ISH for cyclin D1 mRNA is a sensitive method for the evaluation of cyclin D1 overexpression in paraffin-embedded bone marrow biopsy specimens with MM. (2) ISH is more sensitive than immunohistochemical analysis in the assessment of cyclin D1 expression. (3) Cyclin D1 overexpression in MM is correlated positively with higher histologic grade and stage.

Drosophila integrin-linked kinase is required at sites of integrin adhesion to link the cytoskeleton to the plasma membrane.

Integrin-linked kinase (ILK) was identified by its interaction with the cytoplasmic tail of human beta1 integrin and previous data suggest that ILK is a component of diverse signaling pathways, including integrin, Wnt, and protein kinase B. Here we show that the absence of ILK function in Drosophila causes defects similar to loss of integrin adhesion, but not similar to loss of these signaling pathways. ILK mutations cause embryonic lethality and defects in muscle attachment, and clones of cells lacking ILK in the adult wing fail to adhere, forming wing blisters. Consistent with this, an ILK-green fluorescent protein fusion protein colocalizes with the position-specific integrins at sites of integrin function: muscle attachment sites and the basal junctions of the wing epithelium. Surprisingly, mutations in the kinase domain shown to inactivate the kinase activity of human ILK do not show any phenotype in Drosophila, suggesting a kinase-independent function for ILK. The muscle detachment in ILK mutants is associated with detachment of the actin filaments from the muscle ends, unlike integrin mutants, in which the primary defect is detachment of the plasma membrane from the extracellular matrix. Our data suggest that ILK is a component of the structure linking the cytoskeleton and the plasma membrane at sites of integrin-mediated adhesion.

Molecular heterogeneity of the glucose-6-phosphate dehydrogenase deficiency in the Hellenic population.

We report results from a systematic study to identify the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency on a sample of 299 male subjects from the Hellenic population. Our stepwise approach involved partial biochemical characterization and quantitation of the enzyme's activity, MboII restriction endonuclease digestion to identify the G6PD Mediterranean variant, which represents the most frequent G6PD variant in our population and a nonradioactive polymerase chain reaction-single-strand conformation polymorphism methodology for the detection of the underlying molecular defect(s) in the rest of the non-Mediterranean G6PD-deficient individuals. Through this approach, six different G6PD variants were identified (G6PD Mediterranean, G6PD Hermoupolis, G6PD Cassano, G6PD Seattle, G6PD Ierapetra and G6PD Acrokorinthos), two of which were new (G6PD Hermoupolis, G6PD Acrokorinthos). In essence, this study underlines the remarkable genetic heterogeneity of the G6PD deficiency in the Hellenic population, while the finding of the double mutant, G6PD Hermoupolis, may help to outline the relationship and evolution of mutations in the human G6PD locus.

Chelation therapy in patients with thalassemia using the orally active iron chelator deferiprone (L1).

BACKGROUND AND OBJECTIVE: Excessive hemosiderosis is the main reason for the multi-organ failure observed in multitransfused patients. Deferiprone (1,2-dimethyl-3-hydroxy-pyridine-4-one, L1) is an orally active iron chelator mainly excreted via urine. We conducted a study in order to determine the efficacy and safety of L1 in Greek thalassemic patients. DESIGN AND METHODS: A group of 11 thalassaemic patients entered the study; L1, the Cipla formulation for deferiprone, at a daily dose of 75-100 mg/kg bw t.i.d. was used. After giving informed consent all patients were subjected to clinical examination and biological tests. RESULTS: All patients tolerated the L1 well; there were no significant side effects (except for slight gastrointestinal disturbances for the first days). The net urinary iron excretion ranged from 6.96 to 26.1 mg/24h. Serum ferritin declined within 4-6 months in most of the patients. INTERPRETATION AND CONCLUSIONS: The results suggest that L1 is a rather safe drug which decreases iron overload without causing any considerable side-effects in Greek thalassemics.

Sjögren's syndrome in patients with newly diagnosed untreated non-Hodgkin's lymphoma.

The purpose of the study was to detect cases of Sjögren's syndrome among newly diagnosed untreated patients with non-Hodgkin's lymphoma and, furthermore, to identify in such cases clinical and serologic features known to occur more frequently in Sjögren's syndrome patients who evolve into lymphoma. Accordingly, thirty-three cases of newly diagnosed non-Hodgkin's lymphoma, prior to any treatment administration, were thoroughly studied for evidence of Sjögren's syndrome. Immunophenotyping for T and B cells and kappa and lambda light chains was concomitantly performed on both lymphomatous tissues and minor salivary glands. There were 5 patients with T cell and 28 with B cell lymphoma of various histologic subtypes and grades. Two of the latter (7.1%) had a positive for Sjögren's syndrome minor labial salivary gland biopsy, positive responses to the specific questionnaires for both eye and mouth dryness and abnormal Schirmer's and rose Bengal eye tests, substantiating the diagnosis of Sjögren's syndrome. Both were male with lung and stomach non-Hodgkin's lymphoma respectively, enlargement of the lacrimal glands, monoclonal gammapathy of the IgM kappa type and, one of them had high titer and of fine speckled pattern positive antinuclear antibodies and anti-Ro(SSA) and anti-La(SSB) antibodies in his serum. A monotypic infiltrate with kappa light chain restriction, identical to that in the lymphomatous tissue of these two patients, was present in their minor salivary gland biopsy as well. Such a finding was not encountered in any of the remaining patients. Although our sample is relatively small, our results confirm the relationship between Sjögren's syndrome and non-Hodgkin's lymphoma, looked at from the opposite direction. Obviously, studies involving larger populations would be more definitive, regarding the issue of what percentage of this lymphoma patients originates from Sjögren's syndrome.

Hemocyte surface phenoloxidase (PO) and immune response to lipopolysaccharide (LPS) in Ceratitis capitata.

Bacterial lipopolysaccharide (LPS) attachment at the hemocyte surface is based on the crosslinking of surface associated p47 to LPS, via the intermediacy of tyrosine derivatives generated by the action of phenoloxidase (PO). This attachment is an initial step for LPS internalization from hemocytes (Charalambidis et al., 1996). The results presented clearly show the critical role of hemocyte associated PO activity in the above processes. Biochemical and immunofluorescent analysis demonstrated unambiguously the presence of prophenoloxidase (proPO) on the hemocyte surface. The cell-surface expression of proPO appeared to be LPS-independent, whereas its activation was LPS-dependent. The activation of cell surface proPO involves a limited proteolysis, since upon activation with chymotrypsin proPO is converted to a set of smaller molecular weight proteins with PO activity. The activation appears to be due to enzyme activators, serine proteases, released upon LPS-stimulation. This hypothesis was supported from the activation of membrane proPO by the culture medium of hemocytes which have been triggered with LPS. In addition, proPO, activation was abolished by inhibitors of secretion and PMSF. The release of proPO activators upon LPS-stimulation is mediated via protein tyrosine phosphorylation, as genistein inhibited proPO activation, a situation similar to that reported by us for the release of the effector protein p47 (Charalambidis et al., 1995). The LPS-stimulated activation of cell-surface proPO is a prerequisite for LPS (either cell associated or cell free) internalization, as judged by the resistance of LPS binding to dissociation by proteinase K.

Soluble interleukin-6 receptor (sIL-6R), a new prognostic factor in multiple myeloma.

sIL-6R is a 55 kD soluble molecule mediating the interleukin-6 (IL-6) signal through the IL-6 receptor-associated transmembrane signal transducer, gp130. It has recently been suggested that sIL-6R serum levels may reflect disease severity in multiple myeloma (MM). We determined sIL-6R serum levels in 25 normal controls (NC) and in 80 MM patients at diagnosis and during the course of the disease. Measurements were done by ELISA. In NC, sIL-6R levels ranged from 14 to 40 ng/ml (median 28 ng/ml) whereas in MM patients the range was 10-200 ng/ml (median 38 ng/ml) (P<0.01). 61 patients entered remission and 19 were resistant. Median sIL-6R value at diagnosis was 36 ng/ml (10-120) in responding patients, and 82 ng/ml (20-200) in non-responding patients (P<0.001). During a follow-up from 12 to 89 months, sIL-6R values remained more or less stable in most patients. High sIL-6R levels correlated with poor survival.

Immune response in insects: the role of phenoloxidase in defense reactions in relation to melanization and sclerotization.

It is well known that activated prophenoloxidase (proPO) plays an important role in cuticular melanization and sclerotization. In addition, studies dealing with immune response of insects suggest that phenoloxidase (PO) is also critical in the defense reactions of insects against invaders. proPO is activated by elicitors derived from microbial cell wall components such as peptidoglycan, beta-1,3-glucan, and lipopolysaccharide (LPS). According to our recent studies we proposed a model clarifying the role of PO in both cellular and humoral immune responses. LPS triggers Ceratitis capitata hemocytes via induced protein tyrosine phosphorylation to release biologically active molecules, including p47 and proPO-activators. Furthermore, hemocytes in response to LPS facilitate clearance of LPS from the hemocoel of medfly. The effector molecules involved in the LPS clearance are hemocyte surface-associated p47 (mp47), soluble p47 (sp47), activated proPO, and tyrosine. A similar LPS clearance system in the integument of medfly in vitro was also demonstrated. According to our data, the proposed mechanism for LPS clearance from hemocoel and from integument is the crosslinking of LPS to p47 or certain integumental proteins via the intermediacy of reactive tyrosine derivatives generated by PO activity, as is the case for cuticular protein-chitin crosslinks during sclerotization. We also demonstrated that metabolites of the eumelanin biosynthesis and not melanin itself or N-acetyldopamine (NADA), the key precursor of sclerotizing agent, were necessary for the immune responses by hemocytes and integument.

Baker's cyst in rheumatoid arthritis: an ultrasonographic study with a high resolution technique.

OBJECTIVE: To determine the prevalence of popliteal cyst (Baker's cyst) in rheumatoid arthritis (RA), through the use of a very sensitive and non-invasive method, high resolution ultrasonography. The present is the first such report in the literature. METHODS: Ninety-nine unselected consecutive patients with RA, after undergoing routine clinical and laboratory evaluation, had knee radiographs and ultrasound examinations of both knees, the popliteal fossae and calves, using an Ultramark 9ATL apparatus with a 3 MHz curved array and 10 MHz linear array heads and color doppler ability. RESULTS: A Baker's cyst was detected in 47 patients (47.5%) and in a total of 67 out of the 198 knees (33.8%). Four of the 67 cysts were ruptured. Only 29 of the 67 cysts (43.3%) had been diagnosed clinically. A statistically significant correlation was found between the presence of a Baker's cyst and clinical and radiologic involvement of the knee by rheumatoid arthritis (p < 0.025, and p < 0.05 respectively). There was a highly significant correlation between the presence of a cyst and ultrasonographically demonstrated joint effusion (p < 0.001). CONCLUSION: Baker's cyst is very common in RA but it may escape clinical detection. High resolution ultrasound scanning of the area is a simple, highly sensitive and non-invasive technique able to overcome this problem. Therefore, it should be more widely employed by clinicians in the diagnosis of popliteal cysts, which may sometimes be accompanied by significant morbidity.

Lipopolysaccharide-stimulated exocytosis of nonself recognition protein from insect hemocytes depend on protein tyrosine phosphorylation.

Insect hemocytes (blood cells) synthesize the major nonself recognition protein (47 kDa) during 3rd instar larvae (V.J. Marmaras, S. Tsakas, Dev. Biol. 129, 294-303 (1988)). In this study we show the presence of the 47 kDa protein in plasmatocytes (main hemocyte type) and prohemocytes. In plasmatocytes this protein appears to be localized both in vesicles and in the cell surface. The cell surface-associated 47 kDa protein was released from membrane fraction by 1 M NaCl, indicating that it is not tightly bound. Bacterial lipopolysaccharide (LPS) can function on isolated hemocytes from Ceratitis capitata larvae, inducing their spreading and degranulation. During degranulation (exocytosis) the plasmatocytes release the 47 kDa protein, among others. This protein could not be normally traced in serum, nor is it released by basal secretion. The secretion of the 47 kDa protein was found to be LPS-dependent, whereas its presence on plasmatocyte surface is LPS independent. LPS-stimulated exocytosis of the 47 kDa protein appears to be dependent on protein tyrosine phosphorylation. We have now demonstrated that LPS increases tyrosine phosphorylation of 19 and 22 kDa polypeptides in C. capitata hemocytes. Inhibition of the LPS-induced tyrosine phosphorylation mediated by tyrosine kinase inhibitor, genistein, was accompanied by the inhibition of the secretion of the 47 kDa protein. These results support the hypothesis that tyrosine protein phosphorylation is a signal reaction in hemocytes after LPS exposure. These LPS responses of insect plasmatocytes show strong similarities to mammalian macrophages (S. Weinstein et al., J. Immunol. 151, 3829-3838 (1993)). In a model we propose that the LPS-independent cell surface-associated 47 kDa protein is responsible for the phagocytosis and for the formation of nodules and capsules, whereas the LPS-dependent secreting counterpart is responsible for the extracellular killing of bacteria.

HLA antigens in Burger's disease.

The HLA A and B types of 20 Greek patients with thromboangiitis obliterans (TAO) were studied and compared with a panel of 400 controls. A nonstatistically significant increase in the frequencies of HLA B5, B7 and A9 antigens was found. These antigens were found to be associated with a relative risk of 3.47, 3.24 and 2.07 respectively. These findings are partially in agreement with those of a joint English-Swiss study which also found a negative association with B12 antigens; in the Greek population, also of European origin, a negative association was observed with the B8 antigen.