Adipose-derived stem cells: An appropriate selection for osteogenic differentiation

Mesenchymal stem cells (MSCs) are a major component of various forms of tissue engineering. MSCs have self-renewal and multidifferential potential. Osteogenic differentiation of MSCs is an area of attention in bone regeneration. One form of MSCs are adipose-derived stem cells (ASCs), which can be simply harvested and differentiated into several cell lineages, such as chondrocytes, adipocytes, or osteoblasts. Due to special properties, ASCs are frequently used in vitro and in vivo bone regeneration. Identifying factors involved in osteogenic differentiation of ASCs is important for better understanding the mechanism of osteogenic differentiation. Different methods are used to stimulate osteogenesis of ASCs in literature, including common osteogenic media, growth factors, hormones, hypoxia, mechanical and chemical stimuli, genetic modification, and nanotechnology. This review article provides an overview describing the isolation procedure, characterization, properties, current methods for osteogenic differentiation of ASCs, and their basic biological mechanism.     

Prevalence of Pulmonary Hypertension in the General Population: The Rotterdam Study

Background

Pulmonary hypertension is characterized by increased pulmonary artery pressure and carries an increased mortality. Population-based studies into pulmonary hypertension are scarce and little is known about its prevalence in the general population. We aimed to describe the distribution of echocardiographically-assessed pulmonary artery systolic pressure (ePASP) in the general population, to estimate the prevalence of pulmonary hypertension, and to identify associated factors.

Methods

Participants (n = 3381, mean age 76.4 years, 59% women) from the Rotterdam Study, a population-based cohort, underwent echocardiography. Echocardiographic pulmonary hypertension was defined as ePASP>40 mmHg.

Results

Mean ePASP was 26.3 mmHg (SD 7.0). Prevalence of echocardiographic pulmonary hypertension was 2.6% (95%CI: 2.0; 3.2). Prevalence was higher in older participants compared to younger ones (8.3% in those over 85 years versus 0.8% in those between 65 and 70), and in those with underlying disorders versus those without (5.9% in subjects with COPD versus 2.3%; 9.2% in those with left ventricular systolic dysfunction versus 2.3%; 23.1% in stages 3 or 4 left ventricular diastolic dysfunction versus 1.9% in normal or stage 1). Factors independently associated with higher ePASP were older age, higher BMI, left ventricular diastolic dysfunction, COPD and systemic hypertension.

Conclusion

In this large population-based study, we show that pulmonary hypertension as measured by echocardiography has a low prevalence in the overall general population in the Netherlands, but estimates may be higher in specific subgroups, especially in those with underlying diseases. Increased pulmonary arterial pressure is likely to gain importance in the near future due to population aging and the accompanying prevalences of underlying disorders.     

Robust and stable feature selection by integrating ranking methods and wrapper technique in genetic data classification

High dimensional data increase the dimension of space and consequently the computational complexity and result in lower generalization. From these types of classification problems microarray data classification can be mentioned. Microarrays contain genetic and biological data which can be used to diagnose diseases including various types of cancers and tumors. Having intractable dimensions, dimension reduction process is necessary on these data. The main goal of this paper is to provide a method for dimension reduction and classification of genetic data sets. The proposed approach includes different stages. In the first stage, several feature ranking methods are fused for enhancing the robustness and stability of feature selection process. Wrapper method is combined with the proposed hybrid ranking method to embed the interaction between genes. Afterwards, the classification process is applied using support vector machine. Before feeding the data to the SVM classifier the problem of imbalance classes of data in the training phase should be overcame. The experimental results of the proposed approach on five microarray databases show that the robustness metric of the feature selection process is in the interval of [0.70, 0.88]. Also the classification accuracy is in the range of [91%, 96%].     

Sperm status and DNA dose play key roles in sperm/ICSI‐mediated gene transfer in caprine

In relation to the growing recent interest in the establishment of sperm‐mediated gene transfer (SMGT) technology as a convenient and effective method for the simple production of transgenic animals, in this study the possibility of using SMGT to produce transgenic caprine embryos was investigated for the first time. Buck sperm were directly incubated with different concentrations (0–500 ng) of pcDNA/his/Lac‐Z plasmid and used for IVF or ICSI. Sperm used for ICSI were categorized into motile or live‐immotile group before being injected into oocytes. In a separate experiment, dead sperm prepared by repeated freezing/thawing were used for DNA‐incubation before ICSI. Sham injection was carried out by intracytoplasmic injection of approximately the same volume of media containing different doses of DNA using an ICSI needle. Transgene expression and transmission were detected by X‐Gal staining and PCR analysis of developed embryos, respectively. A reasonable blastocyst rate was observed in all the groups. Only embryos in the sham group were negative for transgene transmission. Transgene expression was completely dependent on the delivery technique and status of sperm, and was only observed in the live‐immotile and dead ICSI groups. The results of this study showed that the technique (IVF vs. ICSI vs. sham injection), sperm status (motile vs. live‐immotile vs. dead) and to some extent DNA concentration affect embryo development, transgene transmission and expression. Mol. Reprod. Dev. 77:868–875, 2010. © 2010 Wiley‐Liss, Inc.     

Shotgun strategy-based proteome profiling analysis on the head of silkworm Bombyx mori

Insect head is comprised of important sensory systems to communicate with internal and external environment and endocrine organs such as brain and corpus allatum to regulate insect growth and development. To comprehensively understand how all these components act and interact within the head, it is necessary to investigate their molecular basis at protein level. Here, the spectra of peptides digested from silkworm larval heads were obtained from liquid chromatography tandem mass spectrometry (LC–MS/MS) and were analyzed by bioinformatics methods. Totally, 539 proteins with a low false discovery rate (FDR) were identified by searching against an in-house database with SEQUEST and X!Tandem algorithms followed by trans-proteomic pipeline (TPP) validation. Forty-three proteins had the theoretical isoelectric point (pI) greater than 10 which were too difficult to separate by two-dimensional gel electrophoresis (2-DE). Four chemosensory proteins, one odorant-binding protein, two diapause-related proteins, and a lot of cuticle proteins, interestingly including pupal cuticle proteins were identified. The proteins involved in nervous system development, stress response, apoptosis and so forth were related to the physiological status of head. Pathway analysis revealed that many proteins were highly homologous with the human proteins which involved in human neurodegenerative disease pathways, probably implying a symptom of the forthcoming metamorphosis of silkworm. These data and the analysis methods were expected to be of benefit to the proteomics research of silkworm and other insects.     

Fatty acid composition of canola (Brassica napus L.), as affected by agronomical,genotypic and environmental parameters

Vegetable oils with a high relative amount of unsaturated fatty acids are of great significance for human health. There is not any data on the effects of tillage practices on fatty acid composition of canola (Brassica napus L.). Hence, in a 2-year split plot experiment, the effects of different tillage systems (no (NT), minimum (MT) and conventional tillage (CT)), canola genotypes (Hyola 401 (V1) and PF (V2)) and sowing dates (including Sep. 8, 23 and Oct. 7) on the fatty acid composition of canola were evaluated. Tillage practices and the combination of canola genotypes and sowing dates were randomized to the main and sub-plots, respectively. The highest oleic acid content was the result of combining NT, V1 and Sep. 23, and the lowest was related to the combination of CT, V2 and Oct. 7. While the combination of NT, V1 and D1 resulted in the highest amount of unsaturated fatty acids, this amount was the lowest for the combination of CT, V2 and Sep. 23. For the selection of an appropriate canola producing strategy, all these parameters must be taken into account. The combination of NT, V1 and Sep. 23 may be the most favorable cropping strategy for canola production under a Mediterranean climate.     

Bioprocess engineering of <Emphasis Type="Italic">Echium italicum</Emphasis> L.: induction of shikonin and alkannin derivatives by two-liquid-phase suspension cultures

An in vitro cell suspension culture of Echium italicum was established and assayed for the production of shikonin and alkannin derivatives. Callus tissues were induced from cotyledon explants of the plant incubated onto the solidified B5 medium. A two-liquid-phase system suspension culture was then established to elicit pigments of shikonin and alkannin derivatives using liquid paraffin. The presence of liquid paraffin efficiently induced production of pigments in cultured cells. The production and/or accumulation of these compounds in the E. italicum cells was examined using fluorescence microscopy as the naphthoquinone molecules display autofluorescent properties. Phytochemical analysis of the n-hexane extract of the medium was also carried out using preparative HPLC. The chemical structure of shikonin and alkannin derivatives were characterized by UV, 1H-NMR, and 13C-NMR techniques. Based on our findings, this bioprocess engineering approach resulted in induction of shikonin and alkannin derivatives, whereupon it may be recruited for production of these important secondary metabolites.     

Cadmium Toxicity in Spermatogenesis and Protective Effects of <Emphasis Type="SmallCaps">l</Emphasis>-Carnitine in Adult Male Rats

In this study, the effects of cadmium toxicity and the protective effects of l-carnitine on spermatogenesis in Sprague–Dawley rat were evaluated. Animals were subdivided into five groups. Cadmium chloride (1-mg/kg body weight) was injected intraperitoneally during 16 days at intervals of 48 h between subsequent treatments. l-Carnitine (500 mg/kg b.w., IP) was pretreated in both of control and cadmium-injected rats. Animals were killed on day 17 after the first treatment. The left cauda epididymis was removed and immediately immersed into Hank’s balanced salt solution for evaluation of sperm count and viability. Following contamination with cadmium, a decrease in the number and viability of cauda epididymis sperm, the number of cell proliferation, and Johnsen Scores in the seminiferous tubules was observed. Consequently, l-carnitine treatment caused an increase in the number and viability of cauda epididymis sperm, the number of cell proliferation, and Johnsen Scores in the cadmium-induced group.     

Exposure to Leishmania major modulates the proportion of CD4+ T cells without affecting cellular immune responses

The immune responses of individuals exposed to Leishmania major were evaluated and compared with those of non-exposed volunteers. Forty-one patients with active lesion(s), 43 healed individuals, 15 vaccinees 1 month or 1 year post vaccination, and 15 non-exposed volunteers were studied. Leishmanin skin test (LST) response, proliferative response of lymphocyte (PRL) to L. major antigen, IFN-gamma and IL-4 production, and percentage of L. major-specific CD4+, CD8+ and CD16+/CD56+ cells in peripheral blood mononuclear cells were assessed. Data showed positive LST (>5 mm) in 92% of patients, 98% of healed, and 80% or 43% of vaccinees 1 month and 1 year post vaccination, respectively. Positive PRL (SI>2.5) was displayed in 90%, 84%, 46% and 7% of patients, healed, vaccinated (post 1 year) and non-exposed donors, respectively. The mean +/-S.E. of IFN-gamma was 924 +/- 149, 1,278 +/- 185, 470 +/- 282 or 258 +/- 82 pg/ml in patients, healed cases and vaccinees after 1 month or 1 year, respectively. Positive IFN-gamma responders (>300 pg/ml) were shown in 72% of patients, 81% of healed cases, 31% or 39% of vaccinees and 0% of non-exposed donors. A reduced percentage of CD4+ T-cells and an increased percentage of NK cells were found in exposed individuals compared to non-exposed donors. The data indicated that exposure to L. major modulates the proportion of CD4+ T cells and increases NK cells percentage. However, the cellular immune responses including induction of LST, and IFN-gamma production are increased in exposed individuals.     

Development of modified microdosimetric kinetic model for relative biological effectiveness in proton therapy

To predict the biological effects of ionising radiation, the quantity of biological dose is introduced instead of the physical absorbed dose. In proton therapy, a constant relative biological effectiveness (RBE) of 1.1 is usually applied clinically as recommended by the International Commission of Radiation Units and Measurements. This study presents a new model, based on the modified microdosimetric kinetic model (MMKM), for calculating variable RBE values based on experimental data on the induction of DNA double-strand breaks (DSBs) within cells. The MMKM was proposed based on experimental data for the yield of DSBs in mammalian cells, which allows modification of the yield of primary lesions in the MKM. In this approach, a unique function named f(LET), which describes the relation between RBE and linear energy transfer (LET), was considered for charged particles. In the presented model (DMMKM), the MMKM approach was developed further by considering different f(LET)s for different relevant ions involved in energy deposition events in proton therapy. Although experimental data represent the dependence of the yield of primary lesions on the ion species, the DSB yield (assumed as the main primary lesion) is assumed independent of the ion species in the MMKM. In the DMMKM, by considering the yield of primary lesions as a function of the ion species, the α and β values are in better agreement with the experimental data as compared to those of the MKM and MMKM approaches. The biological dose in the DMMKM is predicted to be lower than that in the MMKM. Further, in the proposed model, the variation of the β parameter is higher than the constant value assumed in the MKM, at the distal end of the spread-out Bragg peak (SOBP). Moreover, the level of cell death estimated by the MMKM at the SOBP region is higher than that obtained based on the DMMKM. It is concluded that considering modified f(LET)s in the model developed here is more consistent with experimental results than when MMKM and MKM approaches are considered. The DMMKM examines the biological effects with full detail and will, therefore, be effective in improving proton therapy.