Molecular and functional characterization of the extracellular calcium-sensing receptor in human colon cancer cells

Presence of a functional extracellular calcium-sensing receptor (CaR) is of particular relevance for the growth-inhibitory action of Ca2+ on human colon carcinoma cells. In order to detect CaR gene alterations that may have occurred during the tumorigenic process, we applied Southern blot, DNA sequence, and RT-PCR analysis to DNA from normal human colon mucosa and from cancerous lesions of different grading, as well as from primary cultured and established colonic carcinoma cell lines (e.g., Caco-2). No evidence was obtained for mutations or other sequence alterations in the CaR gene in any of the colon carcinoma cells analyzed. Only a differential expression of two splice variants of the CaR gene, which are generated by usage of different promoters in the 5'-untranslated region, was detected in colon carcinomas of different grade. From Western blot analysis a tendency towards lower CaR protein levels in carcinoma cells in parallel with tumor progression became apparent. Activation of the CaR by extracellular Ca2+ or by specific receptor agonists resulted in substantial growth inhibition in Caco-2 cells. Activation of the CaR was transduced into inhibition of phospholipase A2-mediated arachidonic acid formation, but also into increased production of cAMP and IP3. This provides evidence for a cell type-specific function of the CaR in human colonocytes. We conclude that neoplastic colon epithelial cells can respond to antimitogenic signals generated by activation of the CaR as long as they express sufficient amounts of the CaR protein. This provides a rationale for the use of calcium in chemoprevention of colon tumor development.     

Intraoperative radiotherapy for head and neck and skull base cancer

BACKGROUND: The purpose of this study was to evaluate the use of intraoperative electron beam radiotherapy (IORT) as an adjuvant modality in the treatment of advanced head and neck and skull base cancer. METHODS: Between 1991 and 1996, 34 patients with squamous cell carcinoma (SCCA) and 10 patients with non-SCCA were enrolled in this prospective nonrandomized clinical trial. Most patients had been previously treated with combinations of surgery, external beam radiotherapy, and chemotherapy. The most frequent sites treated were the skull base (56%) and the neck (44%). IORT was delivered in a dedicated operating room suite with energies of 6 to 15 MeV (6 MeV most commonly used) at doses of 12.5 to 22.5 Gy. RESULTS: At 2 years overall and disease-free survival was 32% and 21%, respectively, for the SCCA patients and 50% and 40%, respectively, for the non-SCCA patients. Tumor control rates at 2 years in the IORT field were 46% for the SCCA patients and 52% for the non-SCCA patients. For squamous cell histology, survival in patients with microscopic residual tumor did not differ from those with no residual tumor, but they both had significantly longer disease-free survival than those patients with gross residual at the time of IORT (p =.03), with a trend toward longer overall survival (p =.09). The only complication directly attributable to IORT was a neuropathy in a patient who received an IORT dose of 22.5 Gy (cumulative dose 130.1 Gy). CONCLUSIONS: IORT at a dose of 12.5 Gy is safe and produces tumor control and survival for patients likely to have microscopic residual disease in sites difficult to resect such as the skull base.     

Biomarker risk assessment and bladder cancer detection in a cohort exposed to benzidine

BACKGROUND: Cancer screening with highly sensitive, specific biomarkers that reflect molecular phenotypic alterations is an attractive strategy for cancer control. We examined whether biomarker profiles could be used for risk assessment and cancer detection in a cohort of Chinese workers occupationally exposed to benzidine and at risk for bladder cancer. METHODS: The cohort consisted of 1788 exposed and 373 nonexposed workers, followed from 1991 through 1997. We assayed urothelial cells from voided urine samples for DNA ploidy (expressed as the 5C-exceeding rate [DNA 5CER]), the bladder tumor-associated antigen p300, and a cytoskeletal protein (G-actin). Workers were stratified into different risk groups (high, moderate, and low risk) at each examination based on a predefined biomarker profile. For workers who developed bladder cancer, tumor risk assessment was analyzed from samples collected 6-12 months before the cancer diagnosis. The associations between risk group and subsequent development of bladder cancer were analyzed by Cox proportional hazards regression analysis and logistic analysis, after adjustment. All statistical tests were two-sided. RESULTS: Twenty-eight bladder cancers were diagnosed in exposed workers and two in nonexposed workers. For risk assessment, DNA 5CER had 87.5% sensitivity, 86.5% specificity, an odds ratio (OR) of 46.2 (95% confidence interval [CI] = 8.1 to 867.0), and a risk ratio (RR) of 16.2 (95% CI = 7.1 to 37.0); p300 had 50.0% sensitivity, 97.9% specificity, an OR of 40.0 (95% CI = 9.0 to 177.8), and an RR of 37.9 (95% CI = 16.8 to 85.3). The risk of developing bladder cancer was 19.6 (95% CI = 8.0 to 47.9) times higher in workers positive for either the DNA 5CER or p300 biomarkers than in workers negative for both biomarkers and 81.4 (95% CI = 33.3 to 199.3) times higher in workers positive for both biomarkers. G-actin was a poor marker of individual risk. CONCLUSIONS: Occupationally exposed workers at risk for bladder cancer can be individually stratified, screened, monitored, and diagnosed based on predefined molecular biomarker profiles.     

Fine mapping and genetic heterogeneity in the pure form of autosomal dominant familial spastic paraplegia

We evaluated seven families segregating pure, autosomal dominant familial spastic paraplegia (SPG) for linkage to four recently identified SPG loci on chromosomes 2q (1), 8q (2), 12q (3), and 19q (4). These families were previously shown to be unlinked to SPG loci on chromosomes 2p, 14q, and 15q. Two families demonstrated linkage to the new loci. One family (family 3) showed significant evidence for linkage to chromosome 12q, peaking at D12S1691 (maximum lod=3.22). Haplotype analysis of family 3 did not identify any recombinants among affected individuals in the 12q candidate region. Family 5 yielded a peak lod score of 2.02 at marker D19S868 and excluded linkage to other known SPG loci. Haplotype analysis of family 5 revealed several crossovers in affected individuals, thereby potentially narrowing the SPG12 candidate region to a 5-cM region between markers D19S868 and D19S220. Three of the families definitively excluded all four loci examined, providing evidence for further genetic heterogeneity of pure, autosomal dominant SPG. In conclusion, these data confirm the presence of SPG10 (chromosome 12), potentially reduce the minimum candidate region for SPG12 (chromosome 19q), and suggest there is at least one additional autosomal dominant SPG locus. Electronic Publication     

Measurement of both protein-bound and total S-2-(3-aminopropylamino)ethanethiol (WR-1065) in blood by high-performance liquid chromatography

A high-performance liquid chromatographic method for automated analysis of both protein-bound and total S-2-(3-aminopropylamino)ethanethiol (WR-1065) in blood has been developed in our laboratory. WR-1065 is the active thiol metabolite of the radio- and chemo-protector drug amifostine (WR-2721). Using WR-1065 quality control levels over the experimental range: 7.0, 45.0 and 85.0 micromol/l spiked into plasma, method validation for total WR-1065 included between-run assessment of imprecision (SD/C.V.%: 1.11/16.7%, 6.58/15.5% and 9.24/11.3%, respectively) and % accuracy (94.7, 106.0 and 97.2%).     

Renal nursing education: an innovative difference

The purpose of this paper is to describe the Master of Nursing (Renal) course that is offered to internal and distance education nephrology nurses in Australia. The challenging demand of offering this innovative curriculum will be discussed, and analysis of the first cohort of students will be made. Finally, future directions for renal nursing education will be discussed.     

Predictors of subclinical nodal involvement in clinical stages I and II non-small cell lung cancer: implications in the inoperable and three-dimensional dose-escalation settings

Purpose: When mediastinal lymph nodes are clinically uninvolved in the setting of inoperable non-small cell lung cancer, whether conventional radiation techniques or three-dimensional dose-escalation techniques are used, the benefit of elective nodal irradiation is unclear. Inclusion of the clinically negative mediastinum in the radiation portals increases the risk of lung toxicity and limits the ability to escalate dose. This analysis represents an attempt to use clinical characteristics to estimate the risk of subclinical nodal involvement, which may help determine which patients are most likely to benefit from elective nodal irradiation.

Methods: From 1987 to 1990, 346 patients undergoing complete resection of non-small cell lung cancer underwent a preoperative computed tomographic scan revealing no clinical evidence of N2/N3 involvement. Multivariate regression and regression tree analyses attempted to define which patients were at highest risk for subclinical mediastinal involvement (N2) and which patients were at highest risk for subclinical N1 and/or N2 involvement (N1/N2). Immunohistochemical data suggest that the conventional histopathologic techniques used during this study somewhat underestimate the true degree of lymph node involvement; therefore, a third end point was also evaluated: N1 involvement and/or N2 involvement and/or local-regional recurrence (N1/N2/LRR).

Results: Regression analyses revealed that the following factors were independently associated with a high risk of more advanced disease: positive preoperative bronchoscopy (N2, p = 0.02; N1/N2, p < 0.0001; N1/N2/LRR, p < 0.001) and tumor grade 3/4 (N1/N2/LRR, p < 0.01). A regression tree analysis was then used to separate patients into risk groups with respect to N1/N2/LRR.

Conclusion: In inoperable non-small cell lung cancer, the patients for whom mediastinal radiation therapy may most likely be indicated are those with a positive preoperative bronchoscopy, especially with large (> 3 cm) primary tumors.     

蛇胆汁中牛磺胆酸含量测定方法的比较研究

目的：比较分析了３种测定蛇胆汁中主要成分牛磺胆酸含量的方法,制定科学合理统一的质量标准。方法：用薄层层析－磷钼酸比色法、薄层扫描法及高效液相色谱法对蛇胆汁中主要成分牛磺胆酸进行测定,并将结果进行比较分析。结果：薄层层析－磷钼酸比色法、薄层扫描法及高效液相色谱法的含量测定结果有一定差异,平均回收率分别为９７．４８％,９８．５１％和１００．３４％,ＲＳＤ分别为４．６％,４．３％和１．５％。结论：高效液     

Sensitivity to etoposide of human malignant glioma cell lines. Mechanisms of action]

AIM OF THE STUDY: Etoposide, a Topoisomerase II inhibitor agent, is currently being explored as a therapeutic agent for brain tumors. The aim of this experimental study was to compare the in vitro etoposide sensitivity of human glioma cells vs human squamous cell carcinoma (SCC) cells. MATERIAL AND METHODS: Twelve human cell lines (six malignant glioma cell lines and six head and neck SCC cell lines) were used for this comparative study. A standard colony formation assay was used to assess cell survival. Since Topoisomerase II is the critical target for etoposide, it was of interest to determine Topoisomerase II activity and etoposide induced inhibition of Topoisomerase II activity for the glioma cells vs the SCC cells. RESULTS: Except for etoposide-induced inhibition of Topoisomerase II activity, no difference was found for etoposide sensitivity and Topoisomerase II activity between the both type of cells. CONCLUSION: These results suggested that the Topoisomerase II reactive agents may prove to be clinically a useful drug for patients presenting with malignant gliomas.