Genetic aspects underlying the normocalcemic and hypercalcemic phenotypes of primary hyperparathyroidism

PURPOSE

Hypercalcemic primary hyperparathyroidism (PHPT) is a common endocrine disorder that has been very well characterized. In contrast, many aspects of normocalcemic primary hyperparathyroidism (NPHPT) such as natural history, organ damage, and management are still matter of debate. In addition, both the pathophysiology and molecular basis of NPHPT are unclear. We investigated whether PHPT and NPHPT patient cohorts share the same pattern of genetic variation in genes known to be involved in calcium and/or bone metabolism.

RESEARCH DESIGN AND METHODS

Genotyping for 9 single nucleotide polymorphisms (SNPs) was performed by Real-Time PCR (TaqMan assays) on 27 NPHPT and 31 PHPT patients evaluated in a tertiary referral Center. The data of both groups were compared with 54 in house-controls and 503 subjects from the 1000 Genomes Project. All groups were compared for allele/haplotype frequencies, on a single locus, two loci and multi-locus basis.

RESULTS

The NPHPT group differed significantly at SNPs in OPG and ESR1. Also, the NPHPT cohort was peculiar for pairwise associations of genotypes and for the overrepresentation of unusual multilocus genotypes.

CONCLUSIONS

Our NPHPT patient set harbored a definitely larger quota of genetic diversity than the other samples. Specific genotypes may help in defining subgroups of NPHPT patients which deserve ad hoc clinical and follow-up studies.

Prolonged cytotoxic effect of aqueous extracts from dried viscum album on bladder cancer cells

Aqueous extracts from whole dried mistletoe (Viscum album L., Iscucin) are often used in anti-cancer treatment. We studied the effect of extracts obtained from mistletoe bushes that grew on different host trees on bladder cancer cells by means of MTT-colorimetric cell proliferation/survival assays. The extracts possessed concentration-dependent cytotoxic properties whose extent varied with the host tree, but did not always correlate with the corresponding mistletoe lectin content. A 2-hours treatment of bladder cancer cells triggered a later, strong cytotoxic effect. This prolonged effect suggests that instillation with Iscucin has therapeutic potential for bladder cancer patients.

Paediatric medulloblastoma cells are susceptible to Viscum album (Mistletoe) preparations

BACKGROUND

Medulloblastoma constitute more than 20% of all paediatric brain tumours and are the most common malignant brain tumours in children. Adjuvant chemotherapy has seen a strong increase in the use of complementary medicine for cancer treatment. Evidence for cytotoxic and apoptotic effects of Viscum album (Mistletoe) in vitro is available, however, no data concerning paediatric tumours, especially paediatric brain tumours, has been provided so far.

MATERIALS AND METHODS

In order to compare the receptiveness of medulloblastoma cells to different Viscum album preparations, in vitro cytotoxic effects of eight Viscum album extracts on four different paediatric medulloblastoma cell lines were analysed by MTT-Tests. Lectin contents of the extracts were determined to correlate them with the mitochondrial activity of mistletoe-treated cells. Flowcytometric analyses with Annexin V-FITC staining were carried out to quantify the amount of apoptotic cells compared to necrotic and viable cells.

RESULTS

Data obtained with the medulloblastoma cell lines, Daoy, D342, D425 and UW-288-2, treated with Viscum album preparations from eight dissimilar host trees (Iscucin Abietis, Pini, Populi, Mali, Salicis, Crataegi, Quercus and Tiliae), indicated a significant growth-inhibition of all cell lines, yet the cell susceptibility was dissimilar against the different extracts. The decrease in mitochondrial activity and increase in apoptosis correlated with the lectin content of the used preparation in a dose-dependent manner.

CONCLUSION

These in vitro results show that paediatric medulloblastoma cells respond to Viscum album preparations, by undergoing cell death through apoptosis and that this growth-inhibition correlates with the lectin content of the used preparation.

Human cancer cells exhibit in vitro individual receptiveness towards different mistletoe extracts

In vitro cytotoxic effects of three aqueous mistletoe extracts on cell physiology against different human tumor cell lines and primary cancer cells were investigated in order to compare the receptiveness of different cancer cells against different mistletoe products. Therefore cell proliferation (BrdU-incorporation assay), mitochondrial activity (MTT-testing) and necrotic cell toxicity (LDH assay) were assayed over serial dilutions of the test products. Data obtained with HELA-S3, MOLT-4, MFM-223, COR-L51, KPL-1 and VM-CUB1 tumor cell lines and Iscador M (20 mg/ml), Iscador Q (20 mg/ml) and Abnobaviscum Fraxini -2 (20 mg/ml) indicated significant growth-inhibition of all cell lines, but also different cell susceptibilities against the different extracts. These variations were not only monitored on established cell lines but also on primary mamma carcinoma cells from surgical resectates. Concerning cell proliferation and mitochondrial activity Abnobaviscum Fraxini exhibits stronger inhibitory effects compared to products from the Iscador series. In case the evaluation was standardized on the active contents of VAA-I within the different products, the Iscador extracts possess higher cytotoxic activity. Pure viscotoxins and mistletoe lectins exhibited less effects than the extracts. The simultaneous presence of pure mistletoe lectins and mistletoe polysaccharides diminished the VAA-mediated cytotoxic effects. The presence of fetal calf serum (FCS) in cultivation media during in vitro testing diminished the cytotoxic effects of mistletoe extracts. It was shown that in vivo application of mistletoe preparations led to the formation of antibodies against unknown compounds of the extracts, diminishing the cytotoxic effect.

Virtual CT intravascular endoscopy of the aorta: pierced surface and floating shape thresholding artifacts

Two types of artifacts may appear in virtual computed tomographic endoscopic views of the aorta rendered at different threshold levels: pierced surface and floating shape artifacts. A positive correlation was found between mean attenuation of the aorta and the threshold levels at which these artifacts appeared. The correlation was statistically significant (0.71 < or = r < or = 0.86) for floating shape. An artifact-free threshold range can be predicted on the basis of aortic enhancement.

Detection of accessory renal arteries with virtual vascular endoscopy of the aorta

PURPOSE

To evaluate the diagnostic accuracy of virtual vascular endoscopy (VVE) in the detection of accessory renal arteries.

METHODS

We retrospectively reviewed the CT angiography data sets of 67 patients (29 male and 38 female; age range 17-72 years, mean age 53 years) imaged for the study of the renal arteries, and affected by renovascular hypertension. All patients also had intraarterial digital subtraction angiography (DSA). CT angiography data sets were processed to obtain maximum intensity projection (MIP) and surface-rendered VVE of the aorta. Axial images, MIP, and VVE were evaluated separately and in combination in the detection of accessory renal arteries. Their results in terms of sensitivity and specificity were then compared with DSA.

RESULTS

Axial images had a sensitivity of 88% and specificity of 94% for accessory renal artery detection, MIP had a sensitivity of 88% and specificity of 98%, and VVE had a sensitivity of 63% and a specificity of 88% (p < 0.05 vs DSA), but these increased to 88% and 98% respectively if endoscopic views were integrated with the other display techniques.

CONCLUSION

VVE based on surface rendering does not add substantial benefits to CTY angiography; by contrast MIP is the most accurate display technique for the detection of accessory renal arteries.

Epoxide hydrolase activity in small biopsy samples of preneoplastic and neoplastic rat liver

Epoxide hydrolase (EH) activity was measured in serial fine-needle aspiration biopsy (FNAB) samples of male rats chronically treated with the hepatocarcinogen, N-nitrosomorpholine (NNM, 10 mg/100 ml drinking water). The development of neoplasia was confirmed histopathologically at the end of the experiment. The enzyme activity was significantly increased after 2 days of NNM administration and reached a 3 to 4-fold increase after 2 weeks that remained stable throughout the experiment. Although EH is not related to the metabolism of NNM, the induction of enzyme as readily recognized with the FNAB method might be a useful marker in the attempt to characterize hepatocarcinogenic substances in rats.

Modulation of the in vivo covalent binding of the carcinogen benzo(a)pyrene to rat liver DNA by selective induction of microsomal and nuclear aryl hydrocarbon hydroxylase activity

The influence of microsomal (mAHH) and nuclear (nAHH) aryl hydrocarbon hydroxylase activity on the covalent binding of tritiated benzo(a)pyrene to rat liver DNA was evaluated in vivo. Induction of mAHH was obtained after phenobarbitone treatment (180% of control), which increased DNA binding to 210%, but left the nAHH unchanged. mAHH and nAHH were slightly induced with dieldrin (130% and 120%), but the binding remained unchanged. The increasing effect of mAHH as well as the possibly decreasing effect of nAHH induction on the binding became obvious when the data of 11 individual rats were used to solve the equation Binding = aX(mAHH) + bX(nAHH) + c. Multiple linear regression analysis resulted in positive values for a and c, a negative value for b, and a multiple correlation coefficient R = 0.82. An influence of other enzymes involved in the metabolism of benzo(a)pyrene cannot be excluded. The study shows clearly that the binding of a foreign compound to DNA in vivo is not only dependent on microsomal enzyme activities but also on nuclear activities even if the latter are considerably lower than those of microsomes.