Bone tissue reconstruction using titanium fiber mesh combined with rat bone marrow stromal cells

The study aim was to evaluate the effect of bone marrow stromal cells (BMSCs) cultured in titanium fiber mesh and implanted in a rat cranial defect. A total of 24 titanium meshes were placed in a tube containing 10 ml BMSC suspension (3 x 10(6)cells/ml) and the tube was rotated on a rotation plate (2 rpm) during 3 h. Thereafter, meshes with cells were subcultured for 1 day under standard conditions. Cell-loaded implants and non-cell-loaded controls were placed in a 8 mm cranial defect and retrieved after 3, 15 and 30 days of implantation. Histology showed that after 3 days of implantation, the mesh porosity of both implant groups was mainly invaded with blood cells. On the other hand, at 15 days of implantation, the cell-loaded implants were filled for 15 +/- 10% of their volume with bone, while the controls showed 1.5 +/- 3.5% of bone. The 30-day cell-loaded implants showed 40 +/- 12.5% of bone and the 30-day control implants 17 +/- 14.5%. At both implantation times the differences were statistically significant. Therefore, we conclude that inoculation of titanium fiber mesh with BMSCs can improve the bone healing capacity of this material.     

Clinical effectiveness of a mite allergen-impermeable bed-covering system in asthmatic mite-sensitive patients

BACKGROUND: Exposure to allergens plays a role in the development of bronchial hyperresponsiveness and in the chronic inflammatory response seen in asthmatic patients. House dust mites (HDMs) are an important source of allergen. Reduction of these allergens might lead to better lung function and reduction of asthma symptoms. OBJECTIVE: The effect of HDM-impermeable covers on HDM allergen levels, peak flow values, and asthma symptoms were measured. Therefore a randomized clinical trial was carried out. METHODS: Fifty-two allergic asthmatic patients were randomly allocated to use the HDM-impermeable or placebo covers. During the study period, daily peak flow and asthma symptom scores were recorded. Dust samples were taken from the mattresses. RESULTS: We observed a significant reduction in HDM allergen levels on the mattresses after encasing them with HDM-impermeable covers (reduction of 87% of Der p 1 in micrograms per gram of dust; P <.001). Baseline symptoms were so low that no improvement could be established. Morning peak expiratory flow is significantly higher in the intervention group compared with that seen in the placebo group during the study period (beta=20.2; P <.01). CONCLUSIONS: HDM-impermeable covers significantly decreased the level of HDM allergens. Furthermore, morning peak flow was significantly increased during the intervention period. This study indicates that HDM allergen-avoidance measures might have beneficial effects on allergen reduction and asthma outcome.     

Structure and genomic sequence of the myotonic dystrophy (DM kinase) gene

The mutation causing myotonic dystrophy (DM) has recently beenidentified as an unstable CTG trinucleotide repeat located inthe 3' untranslated region of a gene encoding for a proteinwith putative serine-threonine protein kinase activity. In thisreport we present the genomic sequences of the human and murineDM kinase gene. A comparison of these sequences with each otherand with known cDNA sequences from both species, led us to predicta translation initiation codon, as well as determine the organizationof the DM kinase gene. Several polymorphisms within the humanDM kinase gene have been identified, and PCR assays to detecttwo of these are described. The complete sequence and characterizationof the structure of the DM kinase gene, as well as the identificationof novel polymorphisms within the gene, represent an importantstep in a further understanding of the genetics of myotonicdystrophy and the molecular biology of the gene.     

Influence of deposition parameters on chemical properties of calcium phosphate coatings prepared by using electrostatic spray deposition

The electrostatic spray deposition (ESD) technique offers the possibility of depositing calcium phosphate (CaP) coatings onto various substrate materials with defined chemical and morphological properties. The relationship between physical, apparatus-related deposition parameters, and the chemical characteristics of ESD coatings was investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive spectroscopy to be able to deposit CaP coatings with tailored chemical properties. The results showed that the chemical characteristics of CaP coatings, deposited with use of the ESD technique, were strongly dependent on the deposition temperature, the nozzle-to-substrate distance, the liquid flow rate, and the geometry of the spraying nozzle. By investigating the influence of the deposition temperature, information could be obtained on the formation mechanism of CaP coatings-and specifically the biologically interesting carbonate apatite phase-using the ESD technique. CaP coatings were not formed merely because of solvent evaporation; a chemical reaction was needed to synthesize the coatings. This reaction involved thermal decomposition of the organic solvent butyl carbitol into carbonate ions via formation of intermediate oxalate ions. The amount of carbonate incorporation, and consequently, the Ca/P ratios of the deposited coatings, was shown 1) to decrease with increasing nozzle-to-substrate distance, 2) to decrease with increasing liquid flow rate, and 3) to decrease by making use of a novel two-component nozzle geometry.     

In vivo magnetic resonance imaging explorative study of ectopic bone formation in the rat

In animal studies of tissue engineering of bone, histology remains the standard for assessing bone formation. As longitudinal studies with this method are feasible only at the cost of large numbers of animals, we looked for an alternative. Therefore, demineralized bone matrix (DBM) and inactivated demineralized bone matrix (iDBM) implants were subcutaneously implanted in a rat. At 1, 3, 5, and 7 weeks postimplantation soft X-ray and magnetic resonance imaging (MRI) were done to monitor bone formation in the implants. At 7 weeks, the animal was killed and the implants were retrieved for histology. Our results showed that in vivo MRI is well suited to assess bone formation larger than 0.5 mm in diameter and to monitor the complete three-dimensional shape of the newly formed bone noninvasively and longitudinally. The MRI results matched well with the histology results obtained at 7 weeks. In contrast, X-ray imaging appeared inappropriate to monitor the bone formation process in DBM.     

Autoradiographic localisation of NMDA, quisqualate and kainic acid receptors in human spinal cord.

The phencyclidine (PCP) binding site of the N-methyl-D-aspartate receptor, the kainic acid (KA) receptor and the quisqualate (QA) receptor were visualised, using autoradiography in the human spinal cord and the distributions compared with that of benzodiazepine (BDZ) receptors and substance P (SP). All of the receptor types, and SP, were concentrated in lamina II of the dorsal horn, consistent with physiological data indicating that glutamate is a neurotransmitter of primary afferent terminals in the spinal cord.