Clinicopathologic correlation of vitamin D receptor expression with retinoid X receptor and MIB-1 expression in primary and metastatic osteosarcoma.

Vitamin D, in addition to its effects on bone, is important in cell cycle regulation. Vitamin D receptor (VDR) has been identified in breast, prostate, and colon cancers, as well as in canine and human osteosarcoma (OS) cell lines; however, it has not been well investigated in human OS-archived specimens. We correlated VDR, retinoid X receptor (RXR), and MIB-1 (Ki-67) expression in 110 archived OS cases with several clinicopathologic parameters including patient's age, sex, tumor location, tumor grade, and type and metastatic status. The expression of VDR and RXR was identified in human OS tissue obtained from primary and metastatic OS archival tissue. No statistically significant difference was found in VDR expression in relation with tumor grade, type, age, sex, or location. The expression of RXR was highest in higher-grade (P = .0006) and metastatic tumors but remained unchanged when correlated with tumor type, age, sex, or location. The expression of MIB-1 was statistically elevated in higher-grade tumors (P = .001), patients 25 years or younger (P = .04), tumors located in extremities (P = .005), and metastatic lesions, but was not impacted by tumor type or patient's sex. Proliferative activity was significantly reduced after treatment, as the mean MIB-1 expression dropped from 11% in primary biopsy samples to 6% in resection specimens. There appears to be a relationship between proliferative tumor activity and tumor grade, location, and metastasis. Additional studies on the analysis of the effects of vitamin D and RXR on OS proliferation, apoptosis, and differentiation are critical to further evaluate their potential role in OS treatment.

Effect of Maternal Cigarette Smoking on Newborn Iron Stores.

BACKGROUND: Maternal smoking has been known to have a negative impact on the well being of the developing fetus. Prenatal smoking has been associated with premature births, low birth weight and with certain birth defects. Small research studies have also found a negative correlation between maternal smoking and neonatal body iron. OBJECTIVES: To study and compare the relationship between maternal and infants' body iron in smokers and non-smokers in a large matched-pair cohort. METHODS: This was a prospective cohort study involving 144 mothers - 72 smokers and 72 non-smokers and their respective infants. Samples were obtained from maternal and infants' cord blood at delivery for Serum transferrin receptor (sTfR) and ferritin levels. Serum TfR and ferritin were measured by RAMCO ELISA and RIA assays. Total Body Iron (TBI) was calculated using the sTfR/ferritin ratio in a previously described formula by Cook et al. RESULTS: Women who smoked had lower sTfR, higher ferritin and higher body iron compared to nonsmoking women. In contrast to their respective mothers, we found a small, but statistically significant negative correlation between smoking and infants' total body iron. The number of packs per day smoked was also negatively correlated with infants' ferritin and total body iron. Lower birth weight was noted in babies of smokers compared to nonsmokers (mean /- SD =3270 +/-475 vs. 3393 g +/- 475 g, p=0.03). CONCLUSION: Women who smoked during pregnancy had higher iron stores but their newborn infants had lower iron stores than those of non-smoking mothers. The more packs per day (PPD) and more days smoked during pregnancy led to lower total body iron of the babies. There may be a negative dose-dependent response between fetal smoke exposure and infant iron stores.

Effect of 25-hydroxyvitamin D3 and 1 α,25 dihydroxyvitamin D3 on differentiation and apoptosis of human osteosarcoma cell lines.

Osteosarcoma (OS) is a malignant bone tumor predominantly affecting children and adolescents. OS has a 60% survival rate with current treatments; hence, there is a need to identify novel adjuncts to chemotherapeutic regimens. In this pilot study, we investigated the dose-response to 1α,25-dihdroxyvitamin D(3) (1,α 25(OH)(2) D(3)) and 25-hydroxyvitamin D(3) (25(OH)D(3)) by human OS cell lines, SaOS-2, and 143B. We hypothesized that 1,α 25(OH)(2) D(3) and 25(OH)D(3) would stimulate differentiation and induce apoptosis in OS cells in a dose-dependent manner. Human OS cell lines, SaOS-2, and 143B, were treated with 1,α 25(OH)(2)D(3) or 25(OH)D(3) or an ethanol control, respectively, at concentrations ranging from 1 to 1,000 nM. Ki67 (a marker of cellular proliferation) immunocytochemistry revealed no significant changes in the expression of Ki-67 or MIB-1 in 1α,25(OH)(2)D(3) or 25(OH)D(3) treated SaOS-2 or 143B cells. Both control and 1α,25(OH)(2) D(3) treated SaOS-2 and 143B cells expressed vitamin D receptor (VDR). Markers of osteoblastic differentiation in 143B cells and SaOS-2 cells were induced by both 25(OH)D(3) and 1α,25(OH)(2) D, and evident by increases in alkaline phosphatase (ALP) activity, osteocalcin (OCN) mRNA expression, and mineralization of extra-cellular matrix (ECM) by alizarin red staining. An increasing trend in apoptosis in response to 25(OH)D(3), in both SaOS-2 and 143B cells was detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining. With 1α,25(OH)(2)D(3) treatment, apoptosis was evident at higher concentrations only. These preliminary findings suggest that OS cells express VDR and respond to 25(OH)D(3) and 1α,25(OH)(2)D(3) by undergoing differentiation and apoptosis.

Acute immune thrombocytopenic purpura in children and adolescents in South Dakota 1998-2004.

Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura, is a rare bleeding disorder caused by increased peripheral platelet destruction. The laboratory and clinical criteria for establishing the diagnosis of acute ITP in children and adolescents are widely accepted. Treatment options for ITP remain controversial. Retrospective data analysis of patients with acute ITP referred to the pediatric Hematology/Oncology Clinic at Sioux Valley Children's Specialty Clinic, seen from August 1998 to December 2004. Fourteen patients out of 25 presented with acute ITP, and had platelet count < or = 10 x 10(9)/L. Life threatening hemorrhage did not occur with any of these patients. Eleven of the analyzed 25 (44%) patients had thrombocytopenia resolve within six months of diagnosis. Nine patients (9/25, 36%) continue to be thrombocytopenic at one year from diagnosis, but without significant bleeding episodes. The clinical presentation, duration and severity of disease in patients with acute ITP seen in our Center are similar to those described in recently published studies. Our approach to treatment differed when compared with other studies. The difference in treatment may be due to patients' significant geographic distance from a tertiary care center, combined with unavailability of necessary treatment in local health institutions.

Management of coagulopathy with recombinant factor VIIa in a neonate with echovirus type 7.

A 5-day-old newborn presented with neonatal enteroviral infection. The patient's hospital course was complicated by acute liver dysfunction, renal insufficiency, fluid overload, respiratory failure, hypertension, catheter related thrombosis, Klebsiella pneumoniae sepsis, intracerebral and intraventricular hemorrhage, and disseminated intravascular coagulation (DIC). Administration of fresh frozen plasma (FFP) and cryoprecipitate failed to control the patient's hemostasis and led to significant fluid overload. Recombinant activated factor VII (rFVIIa, Novoseven NovoNordisk, Bagsvaerd, Denmark) was given to the neonate as a bolus (rFVIIa at 60-80 microg/kg body weight), followed by a continuous infusion (2.5-16 microg/kg/hr). Recombinant activated factor VII controlled hemostasis, until the patient's liver function recovered. The patient's blood product requirement significantly decreased and his fluid overload resolved. Administration of rFVIIa appears to have stabilized the coagulation process. The patient appears to have fully recovered from the infection's complications.

Gene expression and biological significance of hexokinase in erythroid cells.

Red blood cells (RBCs) express two hexokinase (HK) isoforms, HK-I and HK-R. Both isozymes are generated from the HK-I gene by use of an alternate promoter. Gene structure and exon-intron organization of the HK-I gene have been elucidated from a sequence of three contiguous genomic clones localized at human chromosome 10. The sequence spans about 131 kb, and consists of 25 exons, which include 6 testis- and 1 erythroid-specific exons. HK-R has been shown as an erythroid-specific isozyme whose expression is turned on in the early erythroid-progenitors and is significantly induced during their differentiation. HK-R unfolds major HK activity in immature RBCs and is rapidly degraded during the maturation process. HK-I has a porin-binding domain in its N-terminus. Recent studies have shown that HK isozymes with a porin-binding domain play a role in mitochondrial integrity, suggesting that HK-I-deficient erythroid cells might be eliminated by apoptosis. It is most likely that RBCs are most labile as a result of HK-I/R deficiency since the HK-I gene but not the other isozyme genes are expressed in fetal and adult RBCs.