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Biomedical subjects

A Karadag

Publications and source records attributed to A Karadag.

6 recordsLinked to original sources
PubMed2004

Nephrolithiasis associated with ceftriaxone therapy: a prospective study in 51 children.

BACKGROUND: Ceftriaxone, a third generation cephalosporin, is widely used for treating infection during childhood. The kidneys eliminate approximately 33-67% of this agent, and the remainder is eliminated via the biliary system. Ceftriaxone may bind with calcium ions and form insoluble precipitate leading to biliary pseudolithiasis. The aim of this study was to assess whether ceftriaxone associated nephrolithiasis develops by the same mechanism, and whether this condition is dose related. METHODS: The study involved 51 children with various infections. Of these, 24 were hospitalized with severe infection and received 100 mg/kg/day ceftriaxone divided into two equal intravenous doses. The other 27 patients received a single daily intramuscular injection of 50 mg/kg/day. Serum and urine parameters were evaluated before and after treatment, and abdominal ultrasonographic examinations were also carried out before and after treatment. RESULTS: Serum urea, creatinine, and calcium levels were normal in all patients before and after treatment. Post-treatment ultrasound identified nephrolithiasis in four (7.8%) of the 51 subjects. The stones were all of small size (2 mm). Comparison of the groups with and without nephrolithiasis revealed no significant differences with respect to age, sex distribution, duration of treatment, or dose/route of administration of ceftriaxone. The renal stones disappeared spontaneously in three of the four cases, but were still present in one patient 7 months after ceftriaxone treatment. CONCLUSIONS: Conclusions: The study showed that children taking a 7 day course of normal or high dose ceftriaxone may develop small sized asymptomatic renal stones. The overall incidence of nephrolithiasis in this study was 7.8%.

Adolescent↗
PubMed2001

Elevated serum bone sialoprotein and osteopontin in colon, breast, prostate, and lung cancer.

PURPOSE: Histological studies have shown that the two sialoproteins, bone sialoprotein (BSP) and osteopontin (OPN), are induced in multiple types of cancer. We have recently found that these proteins are bound in serum to complement factor H and that the complex must be disrupted to generate free protein to measure their total levels. We hypothesized that measuring total BSP and OPN levels would provide informative markers for the detection of cancer. EXPERIMENTAL DESIGN: As a proof of concept study, serum from patients with diagnosed breast, colon, lung, or prostate cancer (n = 20 for each type) as well as normal serum (n = 77) were analyzed using competitive ELISAs developed for BSP and OPN. Sensitivity, specificity, as well as positive and negative predictive values were determined for each sialoprotein and cancer type. The relationship between sensitivity and specificity was profiled by receiver operating characteristic curves. RESULTS AND CONCLUSIONS: Determined values for serum BSP in ng/ml were 285 +/- 19 for prostate, 373 +/- 19 for colon, 318 +/- 18 for breast, 155 +/- 11 for lung cancer sera, and 154 +/- 13 for normal sera. Values of OPN in ng/ml were 653 +/- 39 for prostate, 449 +/- 22 for colon, 814 +/- 53 for breast, 724 +/- 33 for lung, and 439 +/- 30 for normal sera. The assays provide a high degree of sensitivity and specificity that enables the detection of colon, breast, prostate, and lung cancer.

Biomarkers, Tumor↗
PubMed2000

Human myeloma cells promote the production of interleukin 6 by primary human osteoblasts.

Interleukin-6 (IL-6) is an important growth and survival factor for myeloma cells. However, the identity of the cells producing IL-6 in vivo remains unclear. Myeloma cells are found closely associated with sites of active bone turnover, and cells of the osteogenic lineage, including bone marrow osteoprogenitors, osteoblasts and bone lining cells, may therefore be ideally placed to synthesize IL-6. We have examined the possibility that human osteogenic cells may produce IL-6 in response to stimulation by myeloma cells. Primary human osteoblasts (hOBs) were isolated from normal donors, co-cultured with the human myeloma cell lines, JJN-3, RPMI-8226 and NCI-H929, and the amount of IL-6 released was determined by enzyme-linked immunosorbent assay (ELISA). All myeloma cells stimulated a significant increase in the production of IL-6 when cultured with hOBs (P < 0.05). Prior fixation of hOBs completely abrogated release of IL-6 in the co-cultures. In contrast, fixed myeloma cells retained the ability to induce IL-6 production, suggesting that hOBs were the principal source of IL-6. Physical separation of myeloma cells from hOBs using transwell inserts caused a partial inhibition of IL-6 release (P < 0.05), whereas the addition of media conditioned by myeloma cells to cultures of hOBs stimulated a significant increase in IL-6 production (P < 0.05). hOBs secreted greater amounts of IL-6 than human bone marrow stromal cells (hBMSCs) (2.2- to 3.5-fold, P < 0.05), but incubating hBMSCs with dexamethasone to stimulate osteoblastic differentiation resulted in an increase in their ability to produce IL-6 (1.7- to 4. 8-fold, P < 0.05) and to respond to myeloma cells (P < 0.05). These data clearly indicate that cells of the osteoblast lineage release significant amounts of IL-6 in response to stimulation by myeloma cells and may contribute to the IL-6 that promotes the proliferation and survival of myeloma cells in vivo.

Cell Communication↗
PubMed2000

trans-Bis(diethanolamine)bis(isothiocyanato)nickel(II)

In the neutral title complex, trans-bis(2,2'-iminodiethanol-N, O)bis(isothiocyanato)nickel(II), [Ni(NCS)(2)(C(4)H(11)NO(2))(2)], the isothiocyanate ions and the diethanolamine molecules act as monodentate and bidentate ligands, respectively. The Ni(II) ion exhibits a distorted octahedral configuration with crystallographically imposed inversion symmetry and N(NCS)-Ni-N(amine) and N(NCS)-Ni-O(amine) bond angles of 88.78 (10) and 89.44 (10) degrees, respectively. The Ni-N bond distances are in the range 2.069 (3)-2.096 (2) A. The molecules are linked by hydrogen bonds to form a three-dimensional infinite lattice.

Journal Article↗
PubMed2000

Human myeloma cells promote the recruitment of osteoblast precursors: mediation by interleukin-6 and soluble interleukin-6 receptor.

Multiple myeloma is associated with the development of osteolytic bone disease characterized by a disruption to normal bone resorption and bone formation. Although studies have shown that myeloma cells produce factors that promote bone resorption little data are available examining the mechanism of decreased bone formation or the factors that mediate this effect. In the present study we describe a novel in vitro coculture system in which to investigate the effect of myeloma cells on osteoblast recruitment and differentiation. Under appropriate conditions mesenchymal stem cells were shown to differentiate into colonies of cells, a proportion of which show characteristics of osteoblasts, in that they express alkaline phosphatase activity and stain positively for collagen and calcium. The addition of the human myeloma cells JJN-3, RPMI-8226, or NCI-H929 to these cultures stimulated a significant increase in the total number of colonies (p < 0.005) and the proportion of osteoblastic colonies (p < 0.005). Media conditioned by these cells also were able to promote the formation of both total and osteoblastic colonies (p < 0.005). The addition of an antibody against the interleukin-6 receptor (IL-6R) blocked myeloma cell and myeloma cell-conditioned media induced osteoblast recruitment (p < 0.01). Furthermore, media conditioned by myeloma cells incubated with phorbol ester, which promotes IL-6R shedding, or a metalloproteinase inhibitor, which inhibits IL-6R shedding, were able to stimulate (p < 0.005) and inhibit osteoblast recruitment (p < 0.005), respectively. In addition, soluble IL-6R (sIL-6R) and IL-6 together, but not alone, were able to promote osteoblastic colony formation (p < 0.01). Taken together these data show that myeloma cells promote osteoblast recruitment by release of sIL-6R from myeloma cells.

Alkaline Phosphatase↗