Molecular analysis of the MVK and TNFRSF1A genes in patients with a clinical presentation typical of the hyperimmunoglobulinemia D with periodic fever syndrome: A low‐penetrance TNFRSF1A variant in a heterozygous MVK carrier possibly influences the phenotype of hyperimmunoglobulinemia D with periodic fever syndrome or vice versa

Objective

To describe biochemical findings and the spectrum of mevalonate kinase (MVK) gene mutations as well as an associated TNFRSF1A low‐penetrance variant in a series of patients with clinical features of the hyperimmunoglobulinemia D with periodic fever syndrome (HIDS).

Methods

The MVK gene was sequenced in 8 children and 1 adult (including 2 siblings) fulfilling the clinical criteria for HIDS. In addition, sequencing of exons 2, 3, 4, and 6 of the TNFRSF1A gene was performed in patients with only one or no MVK mutation. Mevalonate kinase (MK) enzyme activity in leukocytes and renal excretion of mevalonic acid were also measured.

Results

Mutations in the coding region of the MVK gene were detected in 6 patients, and the most common mutation was V377I. Among these patients were 2 novel mutations, both of which were located in exon 6. These novel mutations resulted in the substitution of tryptophan (TGG) by a stop codon (TGA) at amino acid position 188 (W188X) and in the exchange of valine (GTG) for alanine (GCG) at amino acid position 203 (V203A). In 1 patient, a combination of one MVK (V377I) mutation and one TNFRSF1A (R92Q) mutation was present. The patient's clinical phenotype resembled a mixture of variant‐type HIDS and tumor necrosis factor receptor–associated periodic syndrome (TRAPS). Her IgD values varied between normal and slightly increased, and the MK activity was in the low‐normal range, while urinary mevalonate concentrations were always normal.

Conclusion

The genotype findings indicate that a relatively small number of genes may be involved in the clinical manifestation of HIDS, with low‐penetrance TNFRSF1A variants possibly influencing the HIDS phenotype or MVK mutations contributing to TRAPS.

     

Response of rat bone marrow cells to differently roughened titanium discs

The purpose of the present in vitro study was to examine the effect of surface roughness on the behaviour of osteoblast-like cells. Rat bone marrow (RBM) cells were cultured on commercially pure titanium discs. The discs were used as machined (Ti M) or ground with 4000 (Ti 4000) or 320 (Ti 320) grit paper. Proliferation rate and alkaline phosphatase activity were determined, and morphology of the cells was studied with scanning electron microscopy (SEM). Besides, fluorescent markers, energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) were used to obtain quantitative and compositional information about the produced calcified extracellular matrix (ECM). Results demonstrated after 2 days of incubation no significant difference in the percentage of attached cells to all substrates. At 5 days, Ti 320 surfaces showed significantly lower (P < 0.05) cell attachment percentages compared with Ti M and Ti 4000 surfaces. At 8 days, Ti 320 surfaces showed significantly more (P < 0.05) cell attachment than the other surfaces. The Ti 4000 surfaces showed after 8 days significantly (P < 0.05) higher alkaline phosphatase activity compared to both other surfaces. At 15 days of incubation, the alkaline phosphatase activity on Ti 4000 substrates was significantly lower (P < 0.05) than on the other substrates. No significant difference in mineralized ECM formation was observed on the ground substrate compared to the machined substrates. Physicochemical analysis confirmed the apatite-like nature of the deposited ECM on all substrates. On the basis of these findings, we concluded that our in vitro study could not clearly confirm the effect of surface roughness on the proliferation, differentiation and calcification of rat bone marrow cells.     

Content and stability of B complex vitamins in commercial cosmetic products

Background

Individual B vitamins have many favorable effects on the skin and are common cosmetic ingredients. However, their formulation is demanding due to stability issues, which consequently affect the products’ quality.

Aims

We aimed to determine the quality (labeling accuracy, content determination, and content-related quality control) and stability under long-term and accelerated storage conditions of a representative sample of commercial cosmetics containing the most common B vitamins – nicotinamide, dexpanthenol, pyridoxine, and cyanocobalamin.

Methods

Cyanocobalamin was determined by a previously published stability-indicating HPLC– diode array detector (DAD) method for the simultaneous determination of all hydrophilic vitamins. This method was additionally simplified and adjusted for the time-effective analysis of nicotinamide, dexpanthenol, and pyridoxine. Both methods were properly validated.

Results

All labeled B vitamins were present in the 36 tested products, mostly in contents, reported effective on the skin. Thus, a straightforward correlation between vitamin contents and product prices were not observed. The content-related quality control of eight products, which quantitively specify their content, revealed significantly lower nicotinamide contents (47% and 57%) in two products and appropriate or higher nicotinamide (102%–112%) and dexpanthenol (100%–104%) contents than declared in the remaining products. The 6-month long-term and accelerated stability studies demonstrated the products’ physical stability, but also revealed dexpanthenol, pyridoxine, and cyanocobalamin degradation, while nicotinamide was mostly stable in the tested products.

Conclusions

The obtained results provide an inside into the quality of commercial vitamin B cosmetics and highlight the importance of stability testing in the formulation of quality, efficient, and safe cosmetics.     

Synthesis of Niobium-Alumina Composite Aggregates and Their Application in Coarse-Grained Refractory Ceramic-Metal Castables

Niobium-alumina aggregate fractions with particle sizes up to 3150 µm were produced by crushing pre-synthesised fine-grained composites. Phase separation with niobium enrichment in the aggregate class 45–500 µm was revealed by XRD/Rietveld analysis. To reduce the amount of carbon-based impurities, no organic additives were used for the castable mixtures, which resulted in water demands of approximately 27 vol.% for the fine- and coarse-grained castables. As a consequence, open porosities of 18% and 30% were determined for the fine- and coarse-grained composites, respectively. Due to increased porosity, the modulus of rupture at room temperature decreased from 52 MPa for the fine-grained composite to 11 MPa for the coarse-grained one. However, even the compressive yield strength decreased from 49 MPa to 18 MPa at 1300 °C for the fine-grained to the coarse-grained composite, the latter showed still plasticity with a strain up to 5%. The electrical conductivity of fine-grained composite samples was in the range between 40 and 60 ^S/cm, which is fifteen magnitudes above the values of pure corundum.     

Treatment with potentially hepatotoxic drugs and the risk of hepatocellular carcinoma: results of a european case – control study

Some toxicological data and case reports have suggested that patients taking potentially hepatotoxic drugs may have an increased risk of benign and malignant liver tumours. Pharmacoepidemiological studies on this issue are sparse, most of them focusing on the association between hepatocellular carcinoma (HCC) and the use of oral contraceptives (OC). The objectives of our study were to examine the risk of HCC in patients taking the drugs mentioned in these case reports and toxicological studies. We used data from an international case – control study which had investigated the risk of HCC in women taking OC including 317 cases of HCC and 1060 frequency age‐matched hospital controls. We investigated the risk for oral antidiabetic and immunosuppressive drugs, methyldopa, nitrofurantoin and clofibrate using unconditional logistic regression analysis. The analysis was adjusted for age, hepatitis B, hepatitis C, alcohol abuse and other risk factors of HCC. The adjusted odds ratios for ever‐use of the investigated drugs varied between 0.67 and 1.64, none of them being statistically significant. There was equally no significantly increased risk for long‐term use of these drugs. Altogether there is no evidence for an increased risk of HCC in patients taking the drugs investigated, however, the relatively small statistical power for certain drugs with a low exposure prevalence has to be taken into account. Copyright © 2000 John Wiley & Sons, Ltd.     

Isolation and analysis of two strongly transforming isoforms of the Epstein-Barr-virus(EBV)-encoded latent membrane protein-1 (LMP1) from a single Hodgkin's lymphoma

Two genes encoding the latent membrane protein 1 (LMP1) of the Epstein-Barr virus (EBV) were isolated from a single case of Hodgkin's disease (HD) and were tested for their biological activities. The LMP1 gene from the Reed-Sternberg cells contained point mutations relative to the prototype LMP1 gene, leading to amino-acid exchanges. The LMP1 gene from passenger lymphocytes showed identical point mutations, but also had an in-frame insertion of 132 base pairs within the 33-bp repeat region. This insert encoding 44 amino acids contained the sequence PSQQS, corresponding to the potential TRAF-binding motif PXQXT/S. When compared to the B95.8 gene, both HD-derived LMP1 genes showed an increase in the transformation of Rat-1 rodent fibroblasts. The transforming ability of the LMP1 gene with the insertion was greater than that of the other HD-derived LMP1, and was comparable with the highly transforming LMP1-Cao gene derived from a nasopharyngeal carcinoma. The HD-derived genes stimulated expression of the cell-surface markers, CD40 and CD54, similarly to the LMP1-B95.8 gene, while the LMP1-Cao gene had a significantly reduced ability to induce these proteins. In contrast, the LMP1-Cao transactivated an NF-κB-response element more efficiently than did the HD-derived genes. Transfer of the 132-bp insert alone into the B95.8 gene did not increase its transforming activity to the LMP1-Cao level, indicating that additional mutations in the LMP1 gene are necessary for modulating this function. Int. J. Cancer 76:194–200, 1998.© 1998 Wiley-Liss, Inc.     

Bone mineral density and bone metabolism of prepubertal children with asthma after long-term treatment with inhaled corticosteroids

Little is known about the effect of long-term treatment with inhaled corticosteroids (ICS) on bone mineral density (BMD) in asthmatic children. In the present cross-sectional study BMD, bone metabolism, height, body composition, and bone age were evaluated in 40 prepubertal children (21 boys) with asthma, treated with a moderate to high dose of ICS over a period of 3 to 8 years. Body composition and BMD of the lumbar spine and total body were measured by Dual Energy X-ray Absorptiometry. BMD results were compared with 148 prepubertal healthy children of the same population. Blood samples were taken for the determination of biochemical bone parameters. The asthmatic children had decreased height, lean tissue mass and fat mass, and a delay of bone maturation, indicating growth retardation. ICS-treated asthma was negatively correlated with total body BMD in a multiple regression model with adjustment for age, gender, height and weight (P = 0.01). Duration of ICS therapy correlated negatively with total body BMD when it was added to the model (P = 0.01). Lumbar spine BMD was not affected by ICS in children with ICS-treated asthma. If age of the asthmatic children was replaced by their bone age in the model, no significant correlation was found between ICS-treated asthma and total body or lumbar spine BMD. The biochemical parameters of bone metabolism were within normal limits. In conclusion, children with asthma who have used ICS daily for 3 to 8 years had lower total body BMD than healthy controls. Long-term longitudinal studies are needed to investigate whether these children attain a normal peak bone mass. Pediatr. Pulmonol. 1997; 24:379–384. © 1997 Wiley-Liss, Inc.