The protein N-glycosylation in plants

In plants, most of the extracellular compartment and the endomembrane system are glycosylated by N-linked oligosaccharides. The N-glycosylation of proteins has a great impact both on their physicochemical properties and on their biological functions. Over the last ten years, a number of laboratories have contributed considerably to the structure, the biosynthesis and the function of plant N-linked glycans. In this review, data on this domain will be summarized and the recent results on the N-glycosylation of a vacuolar lectin, the bean phytohaemagglutinin (PHA) will also be included. This PHA, used as a model glycoprotein, was expressed in different plant systems and the N-glycosylation patterns of different recombinant PHA were compared. In addition to this study on plant-specific glycosylation, the same model glycoprotein was used to investigate whether or not N-glycosylation and N-glycan maturation is organ-specific in plants.Keywords: N-linked oligosaccharide, biosynthesis and function, phytohaemagglutinin.      

Serum proinflammatory mediators at different periods of therapy in patients with multiple myeloma

Multiple myeloma (MM) is a malignant disease characterized by the clonal proliferation of plasma cells within the bone marrow. Several cytokines have been demonstrated to be involved in the control of growth, progression, and dissemination of MM. We determined serum levels of interleukin-1beta (IL-1beta), soluble interleukin-2 receptor (sIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP) in 14 newly diagnosed MM patients. The median age of the patients was 63.4 +/- 10.8 years and all of the patients were stage III (classified according to the Durie-Salmon classification). The same parameters were measured in 15 healthy controls. In addition, we also examined the effects of vincristine-adriamycin-dexamethasone (VAD) therapy on the same parameters and mediators as well as the relationship among the parameters in the same patient groups. The serum concentrations of TNF-alpha, IL-1beta, sIL-2R, IL-6, IL-8, and CRP (18.6 +/- 3.7 pg/mL, 10.1 +/- 2.8 pg/mL, 730 +/- 220 U/mL, 11.4 +/- 3.3 pg/mL, 23.9 +/- 8.3 pg/mL, and 49.9 +/- 19.5 mg/dL, resp) were significantly higher in newly diagnosed MM patients than in healthy controls (P < .0001). All of the parameters were found to be significantly reduced after chemotherapy. In conclusion, we found that after the VAD therapy, the level of these cytokines which are thought to play an important role in the pathogenesis of MM was significantly suppressed. This is the first study demonstrating strong impact of VAD treatment on circulating mediators of sIL-2R and IL-8 levels parameters.     

Serum protein changes in cafeteria mice induced by starvation

Serum protein changes in cafeteria and control mice induced by starvation have been studied. Animals were subjected to food deprivation at 0, 3, 6, 9, 12, 18, 24 or 36 hours. Results show a more stabilized situation in cafeteria mice than controls particularly in protein metabolism. Serum protein composition changed very little during starvation, suggests a lower protein and amino acid catabolism induced by the high adaptation to consume lipids.     

DC in multiple myeloma immunotherapy

Therapy for patients with multiple myeloma (MM) is currently unsatisfactory and most patients eventually succumb to relapsed disease. DCs are a subset of leukocytes with the capacity to initiate and control the adaptive immune response against many cancers, including MM. In MM patients, in vivo DC function is often abnormal, however, it appears that it can be restored by in vitro manipulation. This has led to the development of DC immunotherapy for MM patients. We review the background research leading to the recognition of an anti-MM immune response, and discuss abnormalities in DC function, potential tumor-associated Ags, and the results of clinical trials of DC immunotherapy in MM patients.     

Intracytoplasmic immunofluorescence in multiple myeloma

A new intracytoplasmic immunofluorescence staining procedure has been investigated to detect and quantify myeloma cells by means of flow cytometry. Freshly harvested bone marrow aspirations from 12 patients with multiple myeloma were treated with collagenase and Triton X-100, and incubated with different specimens of fluoro-isothiocyanate-marked antihuman immunoglobulins. DNA-staining was then done with propidium iodide. Biparametric evaluation in a cytofluorograph 6300A/FC 200 showed a characteristic cluster distribution of normal and pathological immunoglobulin-producing cells. This intracytoplasmic fluorochromic staining procedure may be significant for the specific identification of nonsecretive immunocytomas, which cannot be detected by serodiagnostic methods.