Calcium Treatment Research Articles

Application of Calcium Treatment to Sulfur Gear Steel 20CrMo

Based on the thermodynamic calculation, the conditions of calcium treatment to sulfur gear steel are analyzed and the samples of rolled steel are studied. Results show that Calcium treatment to melting steel after RH refining can make the sulfide inclusions and calcium aluminates bind together and form the spindle shaped low melting compound inclusions. In the meanwhile, controlling of w (O) in steel below 0.0012% before calcium treatment is more beneficial to modify the Al2O3 and sulfide by the added calcium and to form the oxide-sulfide compound inclusions only if w (AlS) in steel is adjusted to 0.015%~0.025% before continuous casting. The Ca wire should also be fed at higher temperature.

Quality characteristics of fresh-cut ‘Fuji’ apple slices from 1-methylcyclopropene-, calcium chloride-, and rare earth-treated intact fruits

The residual influence of preservers on the subsequent fresh-cut fruit products has not been well studied. In order to investigate the quality maintenance of fresh-cut products, quality characteristics of fresh-cut ‘Fuji’ apple slices from 1-methylcyclopropene (1-MCP)-, calcium chloride-, or rare earth-treated intact fruits were studied by measuring ethylene production, respiration rate, weight loss, surface color, firmness, titratable acidity (TA), and sensory evaluation during storage. Rare earth pretreatment significantly reduced respiration rate, weight loss percentage, and softness of post-cutting pieces, as compared to control, and the reduced levels were similar to those of calcium treatment. 1-MCP was the most effective treatment in reducing respiration rate and ethylene production of apple slices during the whole storage period. However, rare earth pretreatment was found to be more effective in maintaining cut surface color and TA of post-cutting pieces when compared to calcium and 1-MCP. Rare earth and 1-MCP pretreated samples gave the higher scores of human sensory preference than calcium treated samples. The results suggest that rare earth, along with calcium and 1-MCP, can be used for intact fruits as a potentially promising preserver for better maintenance of firmness, surface color, and prolonged shelf life of fresh-cut fruits.

The roles of calcium-sensing receptor and calcium channel in osteogenic differentiation of undifferentiated periodontal ligament cells

Elevated extracellular calcium has been shown to promote the differentiation of osteoblasts. However, the way that calcium affects the osteogenic differentiation of human periodontal ligament stem/progenitor cells (PDLSCs) remains unclear. Our aim has been to investigate the proliferation and osteogenic differentiation of a calcium-exposed human PDLSC line (cell line 1-17) that we have recently established and to elucidate the roles of the calcium-sensing receptor (CaSR) and L-type voltage-dependent calcium channel (L-VDCC) in this process. Proliferation activity was investigated by WST-1 assay, and gene and protein expression was examined by quantitative reverse transcriptase plus the polymerase chain reaction and immunostaining, respectively. Calcification assay was performed by von Kossa and Alizarin red staining. Treatment with 5mM CaCl2 significantly induced proliferation, bone-related gene expression, and calcification in cell line 1-17. During culture with 5mM CaCl2, this cell line up-regulated the gene expression of CaSR, which was reduced after 7days. Simultaneous treatment with NPS2143, a CaSR inhibitor, and calcium significantly further increased bone-related gene expression and calcification as compared with CaCl2 exposure alone. The L-VDCC inhibitor, nifedipine, significantly suppressed osteogenic differentiation of cell line 1-17 treated with 5mM CaCl2 and promoted the expression of CaSR, as compared with calcium treatment alone. Thus, elevated extracellular calcium promotes the proliferation and osteogenic differentiation of a PDLSC line. Antagonizing CaSR further enhances the effect of calcium on osteogenic differentiation, with CaSR expression being regulated by L-VDCC under extracellular calcium. Extracellular calcium might therefore modulate the osteogenic differentiation of PDLSCs through reciprocal adjustments of CaSR and L-VDCC.

Effectiveness of Calcium Chloride and Calcium Lactate on Maintenance of Textural and Sensory Qualities of Fresh‐Cut Mangos

The effects of calcium chloride (CaCl2 ) and calcium lactate on maintaining textural and sensory quality of fresh-cut "Kent" and "Tommy Atkins" mangos and determination of treatments preferred by consumers were investigated. Mango cubes (1.5 × 1.5 × 1.5 cm) were subjected to different CaCl2 and calcium lactate concentrations (0 M, 0.068 M, 0.136 M, 0.204 M) and dip times (0, 1, 2.5, 5 min). Instrumental quality parameters (firmness, color, soluble solids, titratable acidity) were analyzed periodically during 9 d of storage at 5 °C. Tommy Atkins mango cubes became more orange, but also had more browning than Kent mango cubes during storage at 5 °C. Firmness retention during storage was greater with mangos cubes treated with CaCl2 than with calcium lactate, therefore we focused our instrumental analysis only on CaCl2 -treated cubes. The firmness of Tommy Atkins mango cubes was higher than Kent. Soluble solids content (SSC), titratable acidity (TA), and SSC/TA were higher in fresh-cut Kent mango cubes. Mangos treated with CaCl2 showed retarded softening during storage, and the retardation was greater at higher calcium concentrations. A consumer test was conducted to cluster consumers based on mango preference in order to correlate consumer liking and calcium treatments, as well as to uncover consumer intentions for in-store fresh-cut mango purchases. Treatment at 10 °C with 0.136 M CaCl2 for 2.5 min for Tommy Atkins mangos and 1 min for Kent mangos was effective in retaining firmness during storage at 5 °C and was also not disliked by consumers. A cluster analysis divided consumers into 2 preference groups, with Kent mangos significantly preferred over Tommy Atkins. Fresh-cut mangos often develop tissue softening and discoloration during storage. Short dips (1 to 3 min) in either CaCl2 or calcium lactate effectively improve fresh-cut mango firmness and color retention after cutting. Mango samples treated with CaCl2 had higher liking scores compared to those treated with calcium lactate. "Kent" mango variety is more suitable than "Tommy Atkins" for fresh-cut processing in terms of less tissue browning and higher consumer liking.

There is still a care gap in osteoporosis management for patients with rheumatoid arthritis

ObjectivesTo assess compliance rates with the current Canadian osteoporosis guidelines and whether the Fracture Risk Assessment Tool score in patients with rheumatoid arthritis correlated with the likelihood of receiving osteoporosis treatment and having a bone mineral density test. MethodsCharts of serial outpatients with rheumatoid arthritis were reviewed to collect bone mineral density test data and patients’ use of calcium, vitamin D, and osteoporosis treatment. Odds ratios (OR) were calculated to determine if a higher Fracture Risk Assessment Tool score increased the likelihood of osteoporosis treatment or having a bone mineral density test. ResultsUsing the Fracture Risk Assessment Tool, the 10-year risk of major osteoporotic fracture was high in 92 (12.5%), moderate in 216 (29.3%), and low in 429 (58.2%) patients. Compared to those at low risk, patients identified as high risk were more likely to receive osteoporosis treatment (OR 16.31, 95% CI 9.45–28.13, P<0.001); calcium (OR 3.89, 95% CI 2.43–6.25, P<0.001); vitamin D (OR 3.46, 95% CI 2.12–5.64, P<0.001); and to have had a bone mineral density test (OR 10.22, 95% CI 5.50–18.96, P<0.001). Among 124 patients currently taking prednisone, half (46.8%) were prescribed a bisphosphonate. ConclusionsAlthough compliance with current osteoporosis guidelines remains low among all patients with rheumatoid arthritis, higher risk patients were more likely to have a bone mineral density test and receive treatment for osteoporosis, as indicated by the clear dose response seen along the 10-year fracture risk from low to high-risk groups.

Inclusion Evolution and Estimation during Secondary Refining in Calcium Treated Aluminum Killed Steels

The objective of this study was to investigate the evolution of inclusions during secondary refining in aluminum killed steels. As calcium treatment is also used to modify solid alumina inclusions to liquid or partially liquid calcium aluminates for keeping free from nozzle clogging, a thermodynamic model has been calculated using Factsage to predict the type of calcium aluminates and sulfides present in the steel. The results showed that alumina generated from deoxidation had transformed to MgOAl2O3 spinel with a small amount of CaO by using high basicity and high Al2O3 slag during ladle furnace (LF) refining. Though soft blowing after LF refining is benefit for the removal of inclusions by floatation, vigorous stirring which may make slag layer exposing an “eye” to air reoxidation should be avoided. After calcium treatment, the inclusions were restricted mainly to globular calcium aluminates and the sulfur in the steel was associated with these inclusions as calcium sulfide. The ND (number density) of inclusions seems to appear a similar tendency to the size distribution of smaller inclusions, and the similar change between the AF (area fraction) of inclusions and the total oxygen content of the steel can be also found by careful comparison. Predicted inclusion type in the steel were validated with measurement based on samples collected from industrial heats and a reasonable range of Ca content was also given for the experimental steel.

Inclusion of calcium during isolation of high-density lipoprotein from plasma maintains antioxidant function

We investigated how inclusion of calcium during isolation of high-density lipoprotein (HDL) affected its antioxidant function. Following isolation, HDL was dialyzed against 0.154M NaCl without or with added calcium (1mM). HDL’s paraoxonase 1 activity was unaffected by calcium treatment (87±11% of normal vs. 89±16% of normal, P=0.826). In contrast, whereas HDL dialyzed with calcium inhibited oxidation of low-density lipoprotein (LDL) by 87±10%, HDL dialyzed without calcium inhibited oxidation by only 58±19% (P=0.004). Thus, inclusion of calcium during isolation is important for maintaining HDL’s antioxidant function.

High calcium concentration in bones promotes bone metastasis in renal cell carcinomas expressing calcium-sensing receptor

BackgroundThe prognosis for renal cell carcinoma (RCC) is related to a high rate of metastasis, including 30% of bone metastasis. Characteristic for bone tissue is a high concentration of calcium ions. In this study, we show a promoting effect of an enhanced extracellular calcium concentration on mechanisms of bone metastasis via the calcium-sensing receptor (CaSR) and its downstream signaling molecules.MethodsOur analyses were performed using 33 (11/category) matched specimens of normal and tumor tissue and 9 (3/category) primary cells derived from RCC patients of the 3 categories: non-metastasized, metastasized into the lung and metastasized into bones during a five-year period after nephrectomy. Expression of CaSR was determined by RT-PCR, Western blot analyses and flow cytometry, respectively. Cells were treated by calcium and the CaSR inhibitor NPS 2143. Cell migration was measured in a Boyden chamber with calcium (10 μM) as chemotaxin and proliferation by BrdU incorporation. The activity of intracellular signaling mediators was quantified by a phospho-kinase array and Western blot.ResultsThe expression of CaSR was highest in specimens and cells of patients with bone metastases. Calcium treatment induced an increased migration (19-fold) and proliferation (2.3-fold) exclusively in RCC cells from patients with bone metastases. The CaSR inhibitor NPS 2143 elucidated the role of CaSR on the calcium-dependent effects. After treatment with calcium, the activity of AKT, PLCγ-1, p38α and JNK was clearly enhanced and PTEN expression was almost completely abolished in bone metastasizing RCC cells.ConclusionsOur results indicate a promoting effect of extracellular calcium on cell migration and proliferation of bone metastasizing RCC cells via highly expressed CaSR and its downstream signaling pathways. Consequently, CaSR may be regarded as a new prognostic marker predicting RCC bone metastasis.

Legislation allowing dairy farmers to treat milk fever with intravenous calcium results in more treatments and lower case fatality

Until recently, Danish dairy farmers have not been allowed to treat their own dairy cows suffering from milk fever using intravenous infusions of calcium. Such treatments could only be performed...

Glucocorticoid receptor enhances involucrin expression of keratinocyte in a ligand-independent manner

In this study, we investigated the role of glucocorticoid receptor (GR) in epidermal keratinocytes. In adult normal human skin, GR was highly expressed in the upper layers of the epidermis. Consistent with normal skin, GR expression was increased after calcium treatment of HaCaT keratinocytes cultured in vitro, suggesting that GR is involved in keratinocyte differentiation process. Overexpression of GR using an adenovirus showed that expression of involucrin, an early differentiation marker of keratinocytes, was markedly increased due to GR overexpression. However, treatment with dexamethasone, a GR agonist, did not increase involucrin expression. Overexpression of GR led to phosphorylation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinases (ERK) in the absence of glucocorticoid, suggesting that the GR effect on involucrin expression is related to activation of intracellular signaling cascades. This idea was supported by the fact that GR-mediated involucrin induction was abolished after treatment with JNK and ERK inhibitors. In addition, GR mutants lacking the ligand-binding domain increased involucrin expression concomitantly with increase of ERK phosphorylation. Together, these results suggest that GR modulates involucrin expression of keratinocytes by regulating the intracellular signaling network in a ligand-independent manner.

RNA-seq Analysis of Host and Viral Gene Expression Highlights Interaction between Varicella Zoster Virus and Keratinocyte Differentiation

Varicella zoster virus (VZV) is the etiological agent of chickenpox and shingles, diseases characterized by epidermal skin blistering. Using a calcium-induced keratinocyte differentiation model we investigated the interaction between epidermal differentiation and VZV infection. RNA-seq analysis showed that VZV infection has a profound effect on differentiating keratinocytes, altering the normal process of epidermal gene expression to generate a signature that resembles patterns of gene expression seen in both heritable and acquired skin-blistering disorders. Further investigation by real-time PCR, protein analysis and electron microscopy revealed that VZV specifically reduced expression of specific suprabasal cytokeratins and desmosomal proteins, leading to disruption of epidermal structure and function. These changes were accompanied by an upregulation of kallikreins and serine proteases. Taken together VZV infection promotes blistering and desquamation of the epidermis, both of which are necessary to the viral spread and pathogenesis. At the same time, analysis of the viral transcriptome provided evidence that VZV gene expression was significantly increased following calcium treatment of keratinocytes. Using reporter viruses and immunohistochemistry we confirmed that VZV gene and protein expression in skin is linked with cellular differentiation. These studies highlight the intimate host-pathogen interaction following VZV infection of skin and provide insight into the mechanisms by which VZV remodels the epidermal environment to promote its own replication and spread.

Effect of Al Content on the Characteristics of Inclusions in Al–Ti Complex Deoxidized Steel with Calcium Treatment

Effect of Al Content on the Characteristics of Inclusions in Al–Ti Complex Deoxidized Steel with Calcium Treatment

S100A14, a Member of the EF-hand Calcium-binding Proteins, Is Overexpressed in Breast Cancer and Acts as a Modulator of HER2 Signaling

HER2 is overexpressed in 20–25% of breast cancers. Overexpression of HER2 is an adverse prognostic factor and correlates with decreased patient survival. HER2 stimulates breast tumorigenesis via a number of intracellular signaling molecules, including PI3K/AKT and MAPK/ERK.S100A14,one member of the S100 protein family, is significantly associated with outcome of breast cancer patients. Here, for the first time, we show that S100A14 and HER2 are coexpressed in invasive breast cancer specimens,andthere is a significant correlation between the expression levels of the two proteins by immunohistochemistry. S100A14 and HER2 are colocalized in plasma membrane of breast cancer tissue cells and breast cancer cell lines BT474 and SK-BR3. We demonstrate that S100A14 binds directly to HER2 by co-immunoprecipitation and pull-down assays. Further study shows that residues 956–1154 of the HER2 intracellular domain and residue 83 of S100A14 are essential for the two proteins binding.Moreover,we observe a decrease of HER2 phosphorylation, downstream signaling, and HER2-stimulated cell proliferation in S100A14-silenced MCF-7, BT474, and SK-BR3 cells. Our findings suggest that S100A14 functions as a modulator of HER2 signaling and provide mechanistic evidence for its role in breast cancer progression.

The Expression of Involucrin, Loricrin, and Filaggrin in Cultured Sebocytes

Dear Editor: It is well established that a complex interplay of corneocytes and intercellular lipids in the stratum corneum of the skin is responsible for the skin barrier against environmental factors. A cornified cell envelope, which is composed of involucrin, loricrin, filaggrin, and other proteins, is a component of fully differentiated epidermal keratinocytes and corneocytes, and it is important in the skin barrier1. Although sebaceous gland sebocytes are considered to originate from the same stem cells as epidermal keratinocyte, it is not clear whether the keratinocyte differentiation markers are expressed in the sebocytes or not2. Because the transfollicular route has been known as a major route for drug delivery, more information is required to investigate the expression of the markers in the sebaceous gland sebocytes. A primary culture of human scalp sebocytes was performed with Dulbecco's modified Eagle's medium (DMEM; Gibco BRL, Grand Island, NY, USA) and Epilife (MEPI500CA; Gibco BRL) according to a method described previously3. Sebocytes were cultured at various concentrations of calcium (0.25, 0.5, 1, and 1.2 mM), or treated with vitamin D (10-10, 10-9, 10-8, 10-7, and 10-6 M). Reverse transcription polymerase chain reaction (RT-PCR) for involucrin, loricrin, and filaggrin was conducted in triplicate using the first strand cDNA synthesis kit (Promega, Madison, WI, USA) and oligonucleotide primers (Genotech, Daejeon, Korea). RT-PCR amplification was conducted using the GoTaq Flexi DNA Polymerase: involucrin for 34 cycles at 59℃, loricrin 34 cycles at 69℃, and filaggrin for 30 cycles at 58℃. Immunocytofluorescence for involucrin, loricrin, and filaggrin (Sigma-Aldrich, St. Louis, MO, USA) was also performed on cultured sebocytes. In this study, it was revealed that the expression of involucrin, loricrin, and filaggrin in cultured sebocytes was very weak (Fig. 1, ​,2).2). In addition, their expression in cultured sebocytes was not changed according to calcium concentration or after treatment with vitamin D (Fig. 2). Fig. 1 The expression of involucrin (A), loricrin (B), and filaggrin (C) was very weak in the cytoplasm of cultured sebocytes in immunocytofluorescence. (D) Control (A~D: ×200). Fig. 2 Gene expression of involucrin (A), loricrin (B), and filaggrin (C) in cultured sebocytes after treatment with calcium and VitD (vitamin D), respectively. Cont: control. Sebocytes are highly specialized, lipid-producing epithelial cells that release their contents by a rupture of the cell membrane and cellular degradation during differentiation4. Keratinocyte differentiating markers, including involucrin, loricrin, and filaggrin, provide structural support to the cell. Although sebocytes originate from the same stem cells as keratinocytes, it is thought that there are many differences in the expression of keratinocyte differentiating markers in sebocytes. In addition, it is recognized by our previous study (not published) that sebaceous gland sebocytes in vivo, both basal proliferating cells and central differentiating cells, show little expression of involucrin, loricrin, and filaggrin. Doran et al.5 reported that sebocytes did not produce cornified envelopes in vitro and could only be induced to produce small quantities (less than 5%) of envelopes with a calcium ionophore. However, Lo Celso et al.6 observed the presence of cornifin and involucrin positive immortalized sebocytes. This study showed very weak expression of involucrin, loricrin, and filaggrin in the cytoplasm of cultured sebocytes. Like cultured epidermal keratinocytes, proliferation and differentiation of cultured sebocytes are influenced by extracellular calcium concentration. Vitamin D also induces time- and dose-dependent modulation of cell proliferation and lipid content in cultured sebocytes through binding to vitamin D receptors. Nevertheless, this study showed that both extracellular calcium concentration and treatment with vitamin D did not affect the expression of involucrin, loricrin, and filaggrin in cultured sebocytes. In conclusion, cultured sebocytes showed little expression of keratinocyte differentiation markers. Weak physical barrier in the sebaceous gland may cause much better transfollicular drug delivery.

Comparative Toxicological Studies between Amikacin and Tobramycin Given Alone or with Calcium Gluconate in Rabbits

This study consists of two experiments conducted to explore a toxicological comparison between tobramycin sulphate and amikacin sulphate, and to explore the role of calcium gluconate in antagonizing or reducing the main toxic side effects of tobramycin and amikacin like nephrotoxicity, ototoxicity and neuromuscular blockade.The first experiment was designed to study and measure the acute toxicity of these drugs by using the Up and Down method, which showed that the value of intravenous LD50 of both drugs increased almost twice as much from 154.8 to 294.8 mg/kg for tobramycin and from 437.1 to 737.1 mg/kg for amikacin after the pretreatment with calcium gluconate.The second experiment was performed on rabbits injected with selected toxic dose considered as LD50 of tobramycin and amikacin given by intravenous IV route for the observation of the neurotoxicity signs and recording their appearance time, until the observation of certain definite neurotoxic signs such as loss of righting reflex. At that time, calcium gluconate was given by slow intravenous infusion (over 5-10 minutes) at a high range of therapeutic dose 45mg/kg and the time of disappearance of neuromuscular blockade signs with the number of life and dead animal were recorded for each treatment.The results of this experiment showed that although tobramycin was more potent in inducing neurotoxic effects according to the dose used but amikacin is seems to be more efficacious in developing neurotoxic signs response according to it is short appearance and disappearance time of toxic signs after amikacin and calcium treatment, in comparison with that of tobramycin and calcium treatment.

Oral vitamin D3 supplementation reduces monocyte-derived dendritic cell maturation and cytokine production in Crohn’s disease patients

Low serum vitamin D levels may provoke or aggravate Crohn's disease (CrD). Vitamin D3 is a well-known immune modulator that affects immune functions in vitro and may prevent CrD flares. Dendritic cells (DC) are key mediators of vitamin D3 effects. In this study, we describe changes in monocyte-derived DC (mo-DC) maturation marker expression and cytokine production following 26 weeks of oral vitamin D3 supplementation in CrD patients. Ten CrD patients who had increased serum 25-hydroxy vitamin D levels after oral vitamin D3 and calcium treatment and ten seasonally matched placebo-treated patients were selected for this study. Mo-DC were generated before and after the 26 weeks and induced to mature upon lipopolysaccharide (LPS) stimulation. Maturation marker expression and cytokine production were analysed. Mo-DC function was analysed in a mixed leucocyte reaction (MLR). Compared with baseline values, LPS-matured mo-DC exhibited reduced expression of CD80 and reduced production of the cytokines IL-10, IL-1β, and IL-6 following 26 weeks of oral vitamin D3 supplementation. Mo-DC performance in an allogeneic MLR was unchanged after vitamin D3 supplementation. Treatment with the placebo did not affect maturation markers, cytokine production, or the MLR. Vitamin D3 treatment in CrD patients led to hypo-responsive LPS-stimulated mo-DC. This finding indicates that vitamin D3 levels have an impact on the monocytic precursors of mo-DC in vivo and may explain the positive effects of vitamin D3 supplementation on CrD patients. Alternatively, CrD patients with high serum vitamin D3 levels may represent a subgroup with low disease activity.

Calcium electroporation in three cell lines: a comparison of bleomycin and calcium, calcium compounds, and pulsing conditions

BackgroundElectroporation with calcium (calcium electroporation) can induce ATP depletion-associated cellular death. In the clinical setting, the cytotoxic drug bleomycin is currently used with electroporation (electrochemotherapy) for palliative treatment of tumors. Calcium electroporation offers several advantages over standard treatment options: calcium is inexpensive and may readily be applied without special precautions, as is the case with cytostatic drugs. Therefore, details on the use of calcium electroporation are essential for carrying out clinical trials comparing calcium electroporation and electrochemotherapy. MethodsThe effects of calcium electroporation and bleomycin electroporation (alone or in combination) were compared in three different cell lines (DC-3F, transformed Chinese hamster lung fibroblast; K-562, human leukemia; and murine Lewis Lung Carcinoma). Furthermore, the effects of electrical pulsing parameters and calcium compound on treatment efficacy were determined. ResultsElectroporation with either calcium or bleomycin significantly reduced cell survival (p<0.0001), without evidence of a synergistic effect. Cellular death following calcium or bleomycin treatment occurred at similar applied voltages, suggesting that similar parameters should be applied. At equimolar concentrations, calcium chloride and calcium glubionate resulted in comparable decreases in cell viability. ConclusionsCalcium electroporation and bleomycin electroporation significantly reduce cell survival at similar applied voltage parameters. The effect of calcium electroporation is independent of calcium compound. General significanceThis study strongly supports the use of calcium electroporation as a potential cancer therapy and the results may aid in future clinical trials.

Castability of molten steel and cleanliness of slab for high strength low alloy steel without calcium treatment

Calcium treatment is an important parameter in solving nozzle clogging during continuous casting of Al containing steel. In this study, the process of slag washing was optimised in order to control the compositions of the refining slag. The results showed that the total oxygen (T[O]) content in the casting slab could be controlled to 13–23 ppm and the nitrogen ([N]) content to 21–47 ppm. The total number of macroinclusions in the slab was also reduced to 9·82 mg 10 kg−1 of steel. The typical size of microinclusions in the steel without calcium treatment was <5 μm in the MgO–Al2O3, SiO2–Al2O3 systems, and only a small amount of Al2O3 was found. The rolled metals therefore met the quality and performance requirements of a high strength low alloy steel for engineering applications. Thus, by eliminating the need for calcium treatment, production costs could be reduced significantly, and the cleanliness of the molten steel could be improved.

Adverse Mandibular Bone Effects Associated with Kidney Disease Are Only Partially Corrected with Bisphosphonate and/or Calcium Treatment

Background/Aims: Patients with chronic kidney disease (CKD) have a high prevalence of periodontal disease that may predispose to tooth loss and inflammation. The goal of this study was to test the hypotheses that a genetic rat model of progressive CKD would exhibit altered oral bone properties and that treatment with either bisphosphonates or calcium could attenuate these adverse changes. Methods: At 25 weeks of age, rats were treated with zoledronate (ZOL), calcium gluconate, or their combination for 5 or 10 weeks. Mandible bone properties were assessed using micro-computed tomography to determine bone volume (BV/TV) and cementum-enamel junction to alveolar crest distance (CEJ-AC). Results: Untreated CKD animals had significantly lower BV/TV at both 30 (-5%) and 35 (-14%) weeks of age and higher CEJ-AC (+27 and 29%) compared to normal animals. CKD animals had a significantly higher parathyroid hormone (PTH) compared to normal animals, yet similar levels of C-reactive protein (CRP). ZOL treatment normalized BV/TV over the first 5 weeks but this benefit was lost by 10 weeks. Calcium treatment, alone or in combination with ZOL, was effective in normalizing BV/TV at both time points. Neither ZOL nor calcium was able to correct the higher CEJ-AC caused by CKD. Calcium, but not ZOL, significantly reduced serum PTH, while neither treatment affected CRP. Conclusions: (i) This progressive animal model of CKD shows a clear mandibular skeletal phenotype consistent with periodontitis, (ii) the periodontitis is not associated with systemic inflammation as measured by CRP, and (iii) reducing PTH has positive effects on the mandible phenotype.

Influence of Reoxidation in Tundish on Inclusion for Ca‐Treated Al‐Killed Steel

Reoxidation usually happens during steelmaking, especially in tundish. Severe reoxidation contaminates the steel cleanliness, and detrimentally affects the steel quality and performance. The purpose of this study is to highlight the adverse effect of reoxidation in tundish on non‐metallic inclusion in liquid steel and the end product for Ca‐treated Al‐killed steel. Inclusions of RH refining, tundish, slab, and plate were investigated on API‐X70 pipeline steel. To get a more reliable result, automatic scanning electron microscopy ASPEX PSEM EXPLORER was employed to analyze the inclusion with a much larger scan area. It was found that reoxidation in tundish converted the well‐modified liquid calcium aluminates into solid Al2O3‐rich inclusions, which are more likely to cause nozzle clogging than pure Al2O3, and the inclusion number dramatically increased form 2.8 µm−2 after RH treatment to 13.5 µm−2 in tundish, further decreased to about 6.0 µm−2 in slab and plate. It indicated that reoxidation in tundish put the calcium treatment and strong capacity of inclusion removal during RH treatment in vain. The ratio of liquid inclusions was proportional to average CaO/Al2O3 in inclusions. Big aggregates and stringer shaped inclusions with CaO/Al2O3 locating between 0.08 and 0.13 were found at the 1/2 and 1/4 slab and plate thickness. The stringer shaped inclusions in the plate were the product of big aggregates in the slab after rolling, and made the plate fail to pass ultrasonic testing.