Radiosensitivity of human biliary tract cancer cell lines in vitro

The prognosis of biliary tract cancer is still poor. Although a number of clinical studies have suggested a role for radiation therapy in advanced biliary tract cancer, its value remains controversial. Moreover, the intrinsic radiosensitivity of bile duct cancer cell lines has not been described, and the molecular basis for the response of these tumors to ionizing radiation is poorly understood. The present study was designed to examine the intrinsic radiation sensitivity of human biliary tract cancer cells and its relationship to p53 status. Radiation response expressed by the parameters n, D-0, D-10, alpha, beta, (D) over bar (mean inactivation dose), and SF, of seven cell lines derived from gallbladder and bile duct cancers was determined. The results suggest that biliary tract cancer cell lines as a group are relatively radioresistant. The mean X-ray survival parameters for these seven cancer cell lines were D-0=2.13+/-0.29 Gy, D-10=5.73+/-0.59 Gy, (D) over bar=2.76+/-0.25 Gy, alpha=0.25+/-0.03, and SF2=0.54+/-0.05. One of the seven lines was more radiosensitive than the others (D-0=0.77+/-0.02 Gy, D-10=2.95+/-0.06 Gy, (D) over bar=1.57 Gy, alpha=0.35, SF2=0.35+/-0.03). Five of six lines examined expressed mutant p53 including the radiosensitive line; one radioresistant line expressed wild-type p53. Thus, although loss of wild-type p53 expression occurred frequently in these biliary cancer cell lines, radiosensitivity did not correlate with p53 status. In view of the intrinsic radioresistance of this type of tumor cell coupled with the poor tolerance of surrounding normal tissues, maximal surgical debulking and intraoperative radiation therapy may contribute to increased local control over resection and/or conventional fractionated radiotherapy.

Iron chelators for the treatment of cancer

The study of iron chelators as anti-tumor agents is still in its infancy. Iron is important for cellular proliferation and this is demonstrated by observations that iron-depletion results in cell cycle arrest and also apoptosis. In addition, many iron chelators are known to inhibit ribonucleotide reductase, the iron-containing enzyme that is the rate-limiting step for DNA synthesis. Desferrioxamine is a well known chelator used for the treatment of iron-overload disease, but it has also been shown to possess anti-cancer activity. Another class of chelators, namely the thiosemicarbazones, have been shown to possess anti-cancer activity since the 1950's, although their mechanism(s) of action have only recently been more comprehensively elucidated. In fact, the redox activity of thiosemicarbazone iron complexes is thought to be important in mediating their potent cytotoxicity. Moreover, unlike typical iron chelators which simply act to deplete tumors of iron, several thiosemicarbazones (i.e., Bp44mT and Dp44mT) do not induce this effect, their anti-cancer efficacy being due to other mechanisms e.g., redox activity. Other reports have also shown that some thiosemicarbazones inhibit topoisomerase IIα, demonstrating that this class of agents have multiple molecular targets and act by various mechanisms. The most well characterized thiosemicarbazone iron chelator in terms of its assessment in humans is 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP). Observations from these clinical trials highlight the less than optimal activity of this ligand and several side effects related to its use, including myelo-suppression, hypoxia and methemoglobinemia. The mechanisms responsible for these latter effects must be elucidated and the design of the ligand altered to minimize these problems and increase efficacy. This review discusses the development of chelators as unique agents for cancer treatment.

Association of CD14-260 polymorphisms, red-complex periodontopathogens and gingival crevicular fluid cytokine levels with cyclosporine A-induced gingival overgrowth in renal transplant patients

BACKGROUD AND OBJECTIVE: Genetic factors may influence the colonization of pathogenic bacteria, therefore increasing the risk for the initiation and development of periodontal disease. The present study was carried out to investigate the association of CD14-260 polymorphisms, subgingival microbiota, and gingival crevicular fluid (GCF) cytokine levels with cyclosporine A (CsA)-induced gingival overgrowth (GO) in renal transplant patients.

MATERIAL AND METHODS

A total of 204 patients were dichotomized into two groups: 124 with GO and 80 without GO. The CD14-260 polymorphisms were measured using an allele-specific PCR method. The levels of periodontal pathogens were determined by real-time PCR of subgingival samples. GCF levels of IL-1β and sCD14 were detected by ELISA.

RESULTS

The frequency of CD14-260 genotype CT + TT was found to be similar in both groups. Patients with GO presented increased prevalence of Pg, Td, and Tf (red complex) and significantly higher levels of interleukin -1β than those without GO. Patients with GO carrying CT + TT genotypes were found to have higher frequencies of Pg, Td, and Tf than those carrying the CC genotype. Furthermore, in the presence of red complex, CT + TT genotypes were associated with higher interleukin -1β levels and severe GO. Multiple logistic regression analysis demonstrated that the severity of GO is not dependent on age, gender and pharmacological variables, being only associated with CD14-260 genotype and red complex periodontopathogens.

CONCLUSION

No association between CD14-260 polymorphisms and the prevalence of GO was revealed in renal transplant patients administered CsA. However, CD14-260 CT + TT genotypes are associated with the prevalence of red complex periodontopathogens in patients with GO, and may thus play some role in the development of severe CsA-induced GO.

Reduced soluble receptor for advanced glycation end-products (sRAGE) scavenger capacity precedes pre-eclampsia in Type 1 diabetes

OBJECTIVE

Increased advanced glycation end-products (AGEs) and their soluble receptors (sRAGE) have been implicated in the pathogenesis of pre-eclampsia (PE). However, this association has not been elucidated in pregnancies complicated by diabetes. We aimed to investigate the serum levels of these factors in pregnant women with Type 1 diabetes mellitus (T1DM), a condition associated with a four-fold increase in PE.

DESIGN

Prospective study in women with T1DM at 12.2 ± 1.9, 21.6 ± 1.5 and 31.5 ± 1.7 weeks of gestation [mean ± standard deviation (SD); no overlap] before PE onset.

SETTING

Antenatal clinics.

POPULATION

Pregnant women with T1DM (n = 118; 26 developed PE) and healthy nondiabetic pregnant controls (n = 21).

METHODS

Maternal serum levels of sRAGE (total circulating pool), N(ε)-(carboxymethyl)lysine (CML), hydroimidazolone (methylglyoxal-modified proteins) and total AGEs were measured by immunoassays.

MAIN OUTCOME MEASURES

Serum sRAGE and AGEs in pregnant women with T1DM who subsequently developed PE (DM PE+) versus those who remained normotensive (DM PE-).

RESULTS

In DM PE+ versus DM PE-, sRAGE was significantly lower in the first and second trimesters, prior to the clinical manifestation of PE (P < 0.05). Further, reflecting the net sRAGE scavenger capacity, sRAGE:hydroimidazolone was significantly lower in the second trimester (P < 0.05) and sRAGE:AGE and sRAGE:CML tended to be lower in the first trimester (P < 0.1) in women with T1DM who subsequently developed PE versus those who did not. These conclusions persisted after adjusting for prandial status, glycated haemoglobin (HbA1c), duration of diabetes, parity and mean arterial pressure as covariates.

CONCLUSIONS

In the early stages of pregnancy, lower circulating sRAGE levels, and the ratio of sRAGE to AGEs, may be associated with the subsequent development of PE in women with T1DM.

Novel single nucleotide polymorphisms of the bovine methyltransferase 3b gene and their association with meat quality traits in beef cattle

DNA methylation is essential for adipose deposition in mammals. We screened SNPs of the bovine DNA methyltransferase 3b (DNMT3b) gene in Snow Dragon beef, a commercial beef cattle population in China. Nine SNPs were found in the population and three of six novel SNPs were chosen for genotyping and analyzing a possible association with 16 meat quality traits. The frequencies of the alleles and genotypes of the three SNPs in Snow Dragon beef were similar to those in their terminal-paternal breed, Wagyu. Association analysis disclosed that SNP1 was not associated with any of the traits; SNP2 was significantly associated with lean meat color score and chuck short rib score, and SNP3 had a significant effect on dressing percentage and back-fat thickness in the beef population. The individuals with genotype GG for SNP2 had a 25.7% increase in lean meat color score and a 146% increase in chuck short rib score, compared with genotype AA. The cattle with genotype AG for SNP3 had 35.7 and 24% increases in dressing percentage and 28.8 and 29.2% increases in back-fat thickness, compared with genotypes GG and AA, respectively. Genotypic combination analysis revealed significant interactions between SNP1 and SNP2 and between SNP2 and SNP3 for the traits rib-eye area and live weight. We conclude that there is considerable evidence that DNMT3b is a determiner of beef quality traits.

Use of onyx for transarterial balloon-assisted embolization of traumatic carotid cavernous fistulas: a report of 23 cases

BACKGROUND AND PURPOSE

TCCFs are a common complication following craniofacial trauma and are usually treated by coils or detachable balloons. The use of the liquid embolic agent Onyx as the sole agent for the treatment of TCCFs has been rarely reported. Herein, we summarized the preliminary experience and effectiveness of treating TCCFs with Onyx in 23 patients.

MATERIALS AND METHODS

From the 36 type A CCFs treated in our department between September 2005 and March 2011, a total of 23 posttraumatic direct CCFs were treated by using Onyx only via transarterial approach.

RESULTS

Immediate postprocedural angiograms demonstrated complete occlusion in all patients. All the patients underwent a single procedure except 1 with bilateral TCCFs. Up to 24-month clinical and 3-month angiographic follow-ups revealed an ongoing complete occlusion without any complications.

CONCLUSIONS

In this series, the use of Onyx for the transarterial embolization of TCCFs was feasible and effective. Associated adverse events were rare.

Bp44mT: an orally active iron chelator of the thiosemicarbazone class with potent anti-tumour efficacy

BACKGROUND AND PURPOSE

Our previous studies demonstrated that a thiosemicarbazone iron chelator (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone; Dp44mT) possesses potent and selective anti-cancer activity but led to cardiotoxicity at non-optimal doses. In this study, we examined the in vivo anti-tumour efficacy and tolerability of a new-generation 2-benzoylpyridine thiosemicarbazone iron chelator (2-benzoylpyridine-4,4-dimethyl-3-thiosemicarbazone; Bp44mT) administered via the oral or i.v. routes.

EXPERIMENTAL APPROACH

BpT chelators were tested in vitro against human lung cancer cells (DMS-53) and in vivo in DMS-53 tumour xenografts in mice. The toxicity of Bp44mT in vivo and its effects on the expression of iron-regulated molecules involved in growth and cell cycle control were investigated.

KEY RESULTS

Administration of Bp44mT by either route resulted in marked dose-dependent inhibition of tumour growth. When administered at 50 mg·kg(-1) via oral gavage three times per week for 23 days, the net xenograft growth was inhibited by 75%, compared with vehicle-treated mice. Toxicological examination showed reversible alterations including slight reduction of RBC count, with a decrease of liver and splenic iron levels, which confirmed iron chelation in vivo. Importantly, in contrast to Dp44mT, the chelator-treated mice did not show cardiac histological abnormalities. There was also no significant weight loss in mice, suggesting oral administration of Bp44mT was well tolerated.

CONCLUSIONS AND IMPLICATIONS

This is the first study to show that Bp44mT can be given orally with potent anti-tumour efficacy. Oral administration of a novel and effective chemotherapeutic agent provides the benefits of convenience for chronic dosing regimens.

SU-E-I-08: KV XVI Cone Beam-CT Dose Measurement Using Gafchromic XRQA2 Film

PURPOSE

To study the effect of different filters on the dose response curves of the Gafchromic XRQA2 film. To measure the kV XVI cone-beam CT (CBCT) surface dose received during 3D and 4D imaging protocols in three body regions (head and neck, chest and pelvis).

METHODS

GafChromic XR- QA2 film (International Specialty Products, Wayne, NJ) dose response curves were generated for three irradiation settings: 100 kVp S20/F0; 120 kVp S20/F0 and 120 kVp S20/F1(F1 is a Bowtie filter). Film pieces were irradiated in air by the X-ray Volume Imager (XVI) mounted on the Elekta Synergy linear accelerator (Elekta, Crawley, UK) and their responses were correlated to air kerma measurements. To measure the CBCT surface dose, film pieces were taped on the surface of a male Alderson Rando Phantom (Alderson Research Laboratories, Inc., Long Island City, New York) at four different places (Anterior, Posterior, Right Lateral, Left Lateral).

RESULTS

The dose response curves of XRQA2 film generated with F1 and F0 filters were found to differ by 5 to 7% when the air kerma changed between 2 and 5 cGy. This was less than the observed difference (more than 15%, especially at low air kerma) in the dose response curves when different energies (100 and 120 kVp) and same filter were used. Surface dose ranged between 0.02 cGy and 4.99 cGy. The lowest average surface dose (0.05 cGy) was observed when the fast head and neck protocol was used, whilst the highest average surface dose (3.06 cGy) was noticed when the chest m² 0 protocol was used.

CONCLUSIONS

Filters seem to have less effect on the dose response of the film compared with energy. Gafchromic XRQA2 film was used successfully to measure the XVI CBCT surface dose. The dose was found to vary from one imaging protocol to another, with 4D protocols not necessarily delivering more doses.

SU-E-T-222: How to Define and Manage Quality Metrics in Radiation Oncology

PURPOSE

Since the 2001 IOM Report Crossing the Quality Chasm: A New Health System for the 21st Century, the need to provide quality metrics in health care has increased. Quality metrics have yet to be defined for the field of radiation oncology. This study represents one institutes initial efforts defining and measuring quality metrics using our electronic medical record and verify system(EMR) as a primary data collection tool. This effort began by selecting meaningful quality metrics rooted in the IOM definition of quality (safe, timely, efficient, effective, equitable and patient-centered care) that were also measurable targets based on current data input and workflow.

METHODS

Elekta MOSAIQ 2.30.04D1 was used to generate reports on the number of Special Physics Consults(SPC) charged as a surrogate for treatment complexity, daily patient time in department(DTP) as a measure of efficiency and timeliness, and time from CT-simulation to first LINAC appointment(STL). The number of IMRT QAs delivered in the department was also analyzed to assess complexity.

RESULTS

Although initial MOSAIQ reports were easily generated, the data needed to be assessed and adjusted for outliers. Patients with delays outside of radiation oncology such as chemotherapy or surgery were excluded from STL data. We found an average STL of six days for all CT-simulated patients and an average DTP of 52 minutes total time, with 23 minutes in the LINAC vault. Annually, 7.3% of all patient require additional physics support indicated by SPC.

CONCLUSIONS

Utilizing our EMR, an entire year's worth of useful data characterizing our clinical experience was analyzed in less than one day. Having baseline quality metrics is necessary to improve patient care. Future plans include dissecting this data into more specific categories such as IMRT DTP, workflow timing following CT-simulation, beam-on hours, chart review outcomes, and dosimetric quality indicators.

Novel NaPi-IIc mutations causing HHRH and idiopathic hypercalciuria in several unrelated families: long-term follow-up in one kindred

Homozygous and compound heterozygous mutations in SLC34A3, the gene encoding the sodium-dependent co-transporter NaPi-IIc, cause hereditary hypophosphatemic rickets with hypercalciuria (HHRH), a disorder characterized by renal phosphate-wasting resulting in hypophosphatemia, elevated 1,25(OH)(2) vitamin D levels, hypercalciuria, rickets/osteomalacia, and frequently kidney stones or nephrocalcinosis. Similar albeit less severe biochemical changes are also observed in heterozygous carriers, which are furthermore indistinguishable from those encountered in idiopathic hypercalciuria (IH). We now searched for SLC34A3 mutations (exons and introns) in two previously not reported HHRH kindreds, which resulted in the identification of three novel mutations. The affected members of kindred A were compound heterozygous for two different mutations, c.1046_47del and the intronic mutation c.560+23_561-42del, while the index case in kindred B was homozygous for the nonsense SLC34A3 mutation c.1764C>G (p.Y588X). The patient in kindred C was diagnosed with IH because of bilateral medullary nephrocalcinosis, suppressed PTH levels, and hypercalciuria; she was found to have a novel heterozygous c.1571_1880del mutation. The HHRH patients in kindred A were treated for up to 7years with oral phosphate, which led to reversal of hypophosphatemia, hypercalciuria, and prevention or healing of the mild bone abnormalities. PTH levels were normal throughout the observation period, while 1,25(OH)(2) vitamin D levels remained elevated and may thus be helpful for assessing treatment efficacy and patient compliance in HHRH.