Primary tumor cells of myeloma patients induce interleukin-6 secretion in long-term bone marrow cultures

Long-term bone marrow cultures (LTBMC) from patients with multiple myeloma (MM) and normal donors were analyzed for immunophenotype and cytokine production. Both LTBMC adherent cells from myeloma and normal donor origin expressed CD10, CD13, the adhesion molecules CD44, CD54, vascular cell adhesion molecule 1, very late antigen 2 (VLA-2), and VLA- 5, and were positive for extracellular matrix components fibronectin, laminin, and collagen types 3 and 4. LTBMC from myeloma patients and normal donors spontaneously secreted interleukin-6 (IL-6). However, levels of IL-6 correlated with the stage of disease; highest levels of IL-6 were found in LTBMC from patients with active myeloma. To identify the origin of IL-6 production, LTBMC from MM patients and normal donors were cocultured with BM-derived myeloma cells and cells from myeloma cell lines. IL-6 was induced by plasma cell lines that adhered to LTBMC such as ARH-77 and RPMI-8226, but not by nonadhering cell lines U266 and FRAVEL. Myeloma cells strongly stimulated IL-6 secretion in cocultures with LTBMC adherent cells from normal donors and myeloma patients. When direct cellular contact between LTBMC and plasma cells was prevented by tissue-culture inserts, no IL-6 production was induced. This implies that intimate cell-cell contact is a prerequisite for IL-6 induction. Binding of purified myeloma cells to LTBMC adherent cells was partly inhibited by monoclonal antibodies against adhesion molecules VLA-4, CD44, and lymphocyte function-associated antigen 1 (LFA-1) present on the plasma cell. Antibodies against VLA-4, CD29, and LFA-1 also inhibited the induced IL-6 secretion in plasma cell-LTBMC cocultures. In situ hybridization studies performed before and after coculture with plasma cells indicated that LTBMC adherent cells produce the IL-6. These results suggest that the high levels of IL-6 found in LTBMC of MM patients with active disease are a reflection of their previous contact with tumor cells in vivo. These results provide a new perspective on tumor growth in MM and emphasize the importance of plasma cell-LTBMC interaction in the pathophysiology of MM.     

Early degradation of type IX and type II collagen with the onset of experimental inflammatory arthritis

OBJECTIVE: To determine whether following the onset of intraarticular inflammation, there is early damage to articular cartilage, specifically to types II and IX collagen, and the proteoglycan (PG) aggrecan, and whether measurement of the degradation products of these molecules in synovial fluid (SF) and serum may permit the detection of cartilage damage. METHODS: A rabbit model of rheumatoid arthritis, antigen (ovalbumin)-induced arthritis, was studied. Articular cartilage samples were analyzed by immunoassays for total type II collagen content, its denaturation and cleavage by collagenases, and for type IX collagen content. PG content was determined by colorimetric assay. In serum and SF, total PG content and collagenase-generated peptides of type II collagen were measured. RESULTS: After 6 days, both the PG content and the NC4 domain of type IX collagen were reduced in femoral and tibial cartilage, concomitant with the onset of arthritis. In only the tibial cartilage did this reduction in PG persist up to day 20. However, denatured type II collagen was increased in all cartilage samples, but only on day 20. In SF, the PG content was significantly reduced on day 20, and products of type II collagen cleavage by collagenase were significantly increased on both day 6 and day 20. CONCLUSION: This study, which is the first of its kind examining changes in both types II and IX collagen and PG content, reveals early damage to both types of collagen as well as to PG in articular cartilage samples following induction of joint inflammation. SF analyses reveal this early damage and may be of value in the study and treatment of inflammatory arthritic diseases such as rheumatoid arthritis.     

A review of novel technologies and techniques associated with identification of bloodstream infection etiologies and rapid antimicrobial genotypic and quantitative phenotypic determination

Introduction: The antimicrobial aspect of management of patients with blood stream infections (BSI) and sepsis is time critical. In an era of increasing antimicrobial resistance, rapid detection and identification of bacteria with antimicrobial susceptibility is crucial to direct therapy early in the course of illness. Molecular techniques offer a potential solution to this.

Areas covered: In the present review the authors have discussed a number of novel solutions utilizing a variety of molecular techniques for pathogen detection, identification and antimicrobial susceptibility. The review is not designed to be an exhaustive literature review covering all diagnostic solutions ever developed, instead the authors have focused on what they have had experience using, evaluating or currently view as new and exciting with potential to revolutionize BSI diagnosis.

The authors searched PubMed (Medline) and Google Scholar with terms: BSI, Bacteraemia, Candidaemia, Diagnostics, AST, Rapid, AMR, Novel and Blood Culture. The authors attended recent clinical microbiology technology congresses.

Expert commentary: There are multiple exciting novel technologies at differing stages of development with potential to revolutionize diagnosis of BSI. More work is needed as well as a standardized assessment of different platforms in order to better understand the clinical and financial impacts these will have in clinical microbiology laboratories.     

Antiviral Therapies for Herpesviruses: Current Agents and New Directions

Purpose

The objective of this review was to summarize the recent literature describing the current burden of disease due to herpesviruses in the antiviral and transplant era; describe mechanisms of action of antiviral agents and the development of resistance; summarize the literature of recent antiviral agents brought to market as well as agents under development; and to present literature on future strategies for herpesvirus therapeutics.

Changes in the concentration of 17 alpha,20 alpha-dihydroxypregn-4-en-3-one during pregnancy, labor, and delivery and the effect of dexamethasone treatment during the third trimester of pregnancy

To study whether an alteration of placental steroid metabolism occurs during human pregnancy similar to that in the ewe, we measured the concentration of 17 alpha,20 alpha-dihydroxypregn-4-en-3-one (17,20 alpha-OHP) in peripheral plasma. As the pregnant ewe nears term, the utero-ovarian venous concentrations of 17,20 alpha-OHP increase, suggesting induction of placental 17 alpha-hydroxylase. The mean plasma concentration of 17,20 alpha-OHP measured by RIA in normal menstruating women was 1.1 +/- 0.12 (+/- SE) ng/ml. Similar values were found in plasma from ovariectomized women. In the first and second trimesters of pregnancy, the plasma values of 17,20 alpha-OHP were not significantly different from those in the nonpregnant women, while in the third trimester, the mean plasma concentration was significantly increased (mean +/- SE, 2.6 +/- 0.3 ng/ml). The plasma concentration of 17,20 alpha-OHP was studied in 15 women in late pregnancy, during labor, at delivery, and postpartum. The concentration increased during labor as delivery approached and reached a maximum at the time of delivery, ranging from 4.1-11.2 ng/ml, followed by a significant decrease within 1-4 h postpartum. The mean (+/- SE) 17,20 alpha-OHP concentrations in the venous and arterial cord blood were 8.7 +/- 1.6 and 5.8 +/- 2.0 ng/ml, respectively. To study the effect of increased circulating level of corticosteroids on the serum concentration of progestins, 74 women with premature labor with or without premature rupture of membranes were treated with either placebo or 4 im injections of dexamethasone phosphate (5 mg each) at 12-h intervals. Blood samples were drawn at 0, 14, 26, and 46 h, approximately 2 h after each dexamethasone dose. Plasma progesterone, 17 alpha-hydroxyprogesterone (17-OHP), and 17,20 alpha-OHP values at zero time were 140 +/- 15.8 (+/- SE; n = 21), 7.8 +/- 1.5 ng/ml (n = 16), and 2.3 +/- 0.3 ng/ml (n = 20), respectively. In patients treated with dexamethasone, the plasma progesterone values tended to increase at 14, 20, and 46 h, but 17-OHP and 17,20 alpha-OHP values decreased significantly compared to levels in placebo-treated patients. In conclusion, the concentration of plasma 17,20 alpha-OHP increased during the third trimester of pregnancy, and the increment continued through labor and delivery. During antenatal dexamethasone administration, progesterone in the maternal circulation tended to increase, while 17-OHP and 17,20 alpha-OHP decreased significantly. In the human, in contrast to the ewe, dexamethasone treatment in the third trimester does not appear to stimulate placental 17 alpha-hydroxylase activity.     

Sezary cell morphology induced in peripheral blood lymphocytes: re- evaluation

In this study we examined the effect of mitogens and epidermal cells in inducing a Sezary cell morphology in normal peripheral blood lymphocytes. Peripheral blood mononuclear cells from six healthy volunteers were stimulated with the mitogens phytohemaglutinin and concanavalin A, and also cocultivated with human epidermal cell cultures. Incubation times with mitogens and epidermal cells were four days and stimulation of the lymphocytes by mitogens was confirmed by standard 3H-thymidine uptake. Standard transmission electron microscopy showed that in the mitogen-driven system 20% to 60% (33 +/- 15%) and in the epidermal cell-driven system 5% to 15% (8 +/- 4%) of the lymphoid cells exhibited mild to moderate indentation of the nuclei with nuclear contour indices (NCI) of 4.6 to 6.5 but no Sezary cells were observed (cells with NCI greater than 6.5 and up to 19.2). In the mitogen- stimulated preparation 2% to 5% (3 +/- 1%) of the lymphoid cells showed nuclear multilobulation resembling the cells seen in adult T cell lymphoma/leukemia. Incubation of mononuclear cells for longer periods of up to 4 weeks with mitogens and exogenous IL-2 resulted in no further morphologic changes. Using an indirect immunogold technique at the electron microscopic level, the cells showing nuclear indentation or lobulation were shown to bear both T helper (CD4) and T suppressor (CD8) cell phenotypes in a similar ratio to the total numbers of T helper and T suppressor cells present. Mitogens and epidermal cells are thus not able to induce a morphologic change to Sezary cells in normal peripheral blood lymphocytes.     

Differential matrix degradation and turnover in early cartilage lesions of human knee and ankle joints

OBJECTIVE: To determine whether there are differences in matrix turnover within early cartilage lesions of the ankle (talocrural) joint compared with the knee (tibiofemoral) joint that may help explain differences in the prevalence of osteoarthritis in these 2 joints. METHODS: Cartilage removed from lesions of the tali and femoral condyles was analyzed for type IIB collagen messenger RNA, C-terminal type II procollagen propeptide (CPII), the collagenase cleavage neoepitope (Col2-3/4C(short)), and the denaturation epitope (Col2-3/4m). The content of collagen, glycosaminoglycan, and epitope 846 of aggrecan was quantitated. RESULTS: In ankle lesions, there was an up-regulation of markers of synthesis (CPII [P = 0.07]; epitope 846 [P < or = 0.0001]), but these were down-regulated in the knee (CPII [P = 0.1]; epitope 846 [P = 0.004]). In lesions of the knee, but not the ankle, there was an up-regulation of collagen degradation markers (P = 0.008). On a molar basis, there was 24 times more cleavage epitope than denaturation epitope in knee lesions compared with ankle lesions. CONCLUSION: The up-regulation of matrix turnover that is seen in early cartilage lesions of the ankle would appear to represent an attempt to repair the damaged matrix. The increase in collagen synthesis and aggrecan turnover seen in ankle lesions is absent from knee lesions. Instead, there is an increase in type II collagen cleavage. Together with the differences in collagen denaturation, these changes point to an emphasis on matrix assembly during early lesion development in the ankle and to degradation in the knee, resulting in fundamental differences in matrix turnover in these lesions.