Trace Element Profiles in Single Strands of Human Hair Determined by HR-ICP-MS

Trace element analysis of human hair has the potential to reveal retrospective information about an individual's nutritional status and exposure. As trace elements are incorporated into the hair during the growth process, longitudinal segments of the hair may reflect the body burden during the growth period. We have evaluated the potential of human hair to indicate exposure or nutritional status over time by analysing trace element profiles in single strands of human hair. The hair strands from five healthy and occupationally unexposed subjects were cut into 1-cm long segments starting from the scalp. By using high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), we achieved profiles of 12 elements in single strands of human hair, namely, Ag, As, Au, Cd, Cu, Hg, Fe, Pb, Se, Sr, U and Zn. We have shown that trace element analysis along single strands of human hair can yield information about essential and toxic elements, and for some elements, can be correlated with seasonal changes in diet and exposure. The information obtained from the trace element profiles of human hair in this study substantiates the potential of hair as a biomarker.     

Reduced connectivity in the self-processing network of schizophrenia patients with poor insight

Lack of insight (unawareness of illness) is a common and clinically relevant feature of schizophrenia. Reduced levels of self-referential processing have been proposed as a mechanism underlying poor insight. The default mode network (DMN) has been implicated as a key node in the circuit for self-referential processing. We hypothesized that during resting state the DMN network would show decreased connectivity in schizophrenia patients with poor insight compared to patients with good insight. Patients with schizophrenia were recruited from mental health care centers in the north of the Netherlands and categorized in groups having good insight (n = 25) or poor insight (n = 19). All subjects underwent a resting state fMRI scan. A healthy control group (n = 30) was used as a reference. Functional connectivity of the anterior and posterior part of the DMN, identified using Independent Component Analysis, was compared between groups. Patients with poor insight showed lower connectivity of the ACC within the anterior DMN component and precuneus within the posterior DMN component compared to patients with good insight. Connectivity between the anterior and posterior part of the DMN was lower in patients than controls, and qualitatively different between the good and poor insight patient groups. As predicted, subjects with poor insight in psychosis showed decreased connectivity in DMN regions implicated in self-referential processing, although this concerned only part of the network. This finding is compatible with theories implying a role of reduced self-referential processing as a mechanism contributing to poor insight.     

Nucleoplasmin facilitates reprogramming and in vivo development of bovine nuclear transfer embryos

Successful cloning by somatic cell nuclear transfer (NT) involves an oocyte-driven transition in gene expression from an inherited somatic pattern, to an embryonic form, during early development. This reprogramming of gene expression is thought to require the remodeling of somatic chromatin and as such, faulty and/or incomplete chromatin remodeling may contribute to the aberrant gene expression and abnormal development observed in NT embryos. We used a novel approach to supplement the oocyte with chromatin remodeling factors and determined the impact of these molecules on gene expression and development of bovine NT embryos. Nucleoplasmin (NPL) or polyglutamic acid (PGA) was injected into bovine oocytes at different concentrations, either before (pre-NT) or after (post-NT) NT. Pre-implantation embryos were then transferred to bovine recipients to assess in vivo development. Microinjection of remodeling factors resulted in apparent differences in the rate of blastocyst development and in pregnancy initiation rates in both NPL- and PGA-injected embryos, and these differences were dependent on factor concentration and/or the time of injection. Post-NT NPL-injected embryos that produced the highest rate of pregnancy also demonstrated differentially expressed genes relative to pre-NT NPL embryos and control NT embryos, both of which had lower pregnancy rates. Over 200 genes were upregulated following post-NT NPL injection. Several of these genes were previously shown to be downregulated in NT embryos when compared to bovine IVF embryos. These data suggest that addition of chromatin remodeling factors to the oocyte may improve development of NT embryos by facilitating reprogramming of the somatic nucleus.     

Production of cloned pigs from in vitro systems

Here we describe a procedure for cloning pigs by the use of in vitro culture systems. Four healthy male piglets from two litters were born following nuclear transfer of cultured somatic cells and subsequent embryo transfer. The initiation of five additional pregnancies demonstrates the reproducibility of this procedure. Its important features include extended in vitro culture of fetal cells preceding nuclear transfer, as well as in vitro maturation and activation of oocytes and in vitro embryo culture. The cell culture and nuclear transfer techniques described here should allow the use of genetic modification procedures to produce tissues and organs from cloned pigs with reduced immunogenicity for use in xenotransplantation.     

Economic assessment of commercial hatchery production of milkfish (Chanos chanos Forsskal) fry

The economic viabilities of two types of commercial hatchery milkfish ( Chanos chanos Forsskal) fry operations were assessed and compared. Based on the actual cost of input, the physical facilities, and the potential production yields, four commercial hatcheries previously used for shrimp ( Penaeus monodon Fabricius) fry production were classified as either large- or small-scale operations. Cost–return analysis revealed high profits for both types of operation. The return on investment (54–61%) and the payback period (≈ 1.5 years) were comparable between the two types, although a large-scale operation (476%) had double the working capital return of a small-scale hatchery (221%). Benefit–cost analysis over a 5-year period also revealed positive and above-baseline discounted economic indicators [net current value = 0.2–2.2 million Philippine Pesos (1 US Dollar = 25 Philippine Pesos); internal rate of return = 88–107%]. The net benefit–cost ratio of a large-scale operation (2.0) was higher than that of a small-scale hatchery (1.4), suggesting a slight edge in the investment viability of a large-scale hatchery. Compared with a large-scale operation, a small-scale hatchery was more sensitive to changes in the acquisition price of eggs or newly-hatched larvae and in the price of selling hatchery fry. Both types of operation are viable nonetheless when the acquisition cost is P6000 per million eggs or larvae and hatchery fry are sold at P0.50 each. Together, profit and investment in milkfish hatchery fry production appear viable, making milkfish an alternative commodity for production in many abandoned shrimp hatcheries. The limited availability of spawned eggs and larvae for rearing and the quality of hatchery fry are issues requiring urgent attention.     

Induction of Systemic Resistance to Tobacco Powdery Mildew by Tobacco Mosaic Virus, Tobacco Necrosis Virus or Ethephon

Local infections of either TMV or TNV in tobacco plants cv. Havana 425 (hypersensitive to TMV) proved effective in inducing systemic resistance to subsequent inoculation with the powdery mildew fungus Erysiphe cichoracearum DC. The proportion of leaf surface invaded by this pathogen and the amount of conidia it produced were both significantly lower in virus inoculated plants than in non-inoculated controls. However, the decrease in sporulation rate was less regularly observed than the reduction in leaf area infected. TMV was more effective than TNV in protecting tobacco plants from powdery mildew. E. cichoracearum is thus added to the list of challenge pathogens to which TMV or TNV are known to induce resistance in the host plants. Necrotic lesions caused to the leaves by local treatment with Ethephon (an ethylene-releasing compound) also conferred to tobacco some degree of systemic resistance to the same fungal pathogen, more frequently visible as a reduction of leaf area invaded. The protection due to the Ethephon lesions was in present experiments less marked than that of TMV. No effects against subsequent powdery mildew infection were obtained when point freeze necrotic lesions were provoked on the plants.     

Can browsing by deer in winter induce defence responses in bilberry (<Emphasis Type="Italic">Vaccinium myrtillus</Emphasis>)?

Wild ungulates are key determinants in shaping boreal plant communities, and may also affect ecosystem function through inducing the plant defence systems of key plant species. We examined whether winter browsing by deer could increase the resistance of bilberry (Vaccinium myrtillus). We used three indicators of induced bilberry defence: reduced growth (a), reduced reproduction (b) and decreased insect herbivory (c) in focal plants. In a field experiment, using a randomised block design, we exposed half of plants twice in winter to exogenously applied methyl jasmonate (MeJA) and crossed this factor with randomly selecting browsed and unbrowsed plants. We predicted that MeJA-plants would have significant lower growth, reproduction and insect herbivory than Control plants. We also expected that Browsed plants would experience similar negative effects and that there would be an interaction between MeJa and Browsed indicating a possible additive effect. Growth, flowering and insect herbivory were significantly lower in MeJA than in Control, as expected. We did not find the same reduction for Browsed and no significant interaction between factors. The combined treatment, unexpectedly, flowered more and showed higher levels of insect herbivory than MeJA. Our study showed that defence responses of bilberry may be induced by exogenously-applied MeJA in winter. Our study could not confirm whether winter browsing by deer can induce the same defence responses.     

Effects of β-alanine treatment on the taurine and DNA content of the rat heart and retina

Experimental evidence has suggested that the high endogenous levels of taurine found in the rat heart and retina are maintained to a large extent by transport processes out of the blood, rather than by endogenous biosynthesis. When these high levels are depleted, dysfunction ensues. In vitro studies have shown that -alanine is a good antagonist of these transport processes. The current studies were done to evaluate the feasibility of depleting heart and retinal taurine levels in vivo through treatment of adult rats either orally or with injections of -alanine. None of the treatments had significant effects on retinal taurine content; ventricular taurine was reduced in some situations, but the effects were not maintained, nor as large as with another transport antagonist. No functional changes were observed. Oral treatment with -alanine had fewer obvious side effects than injections, but all treated rats had body weights less than age-matched controls.     

N-3 HUFAs affect fat deposition,susceptibility to oxidative stress,and apoptosis in Atlantic salmon visceral adipose tissue

We have investigated how n-3 highly unsaturated fatty acids (HUFAs) in the diet affect fatty acid (FA) utilization, fat storage and oxidative stress (OS) in Atlantic salmon (Salmo salar) white adipose tissue (WAT). Four groups of Atlantic salmon were fed for 21 weeks on one of the four diets supplemented with 23% (of dry matter) lipid. Docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels increased from 10% of total FAs in the rapeseed oil (RO) diet, to 20% in the fish oil (FO) diet, and to 50% and 55% in the DHA-enriched and EPA-enriched diets, respectively. Increased dietary levels of n-3 HUFAs resulted in lower fat percentage in WAT. Furthermore, mitochondrial FA β-oxidation activity was higher in the FO group than it was in the RO group. The relative levels of DHA and EPA in phospholipids (PLs) from WAT and mitochondrial membranes increased with the increasing dietary levels of these HUFAs. In general, the mitochondrial membrane PLs were characterised by lower relative levels of n-3 HUFAs and higher relative levels of linoleic acid (LA; 18:2 n-6) than WAT membrane PLs. The predominance of LA relative to n-3 HUFAs in mitochondrial membrane PLs may help to protect these PLs from peroxidation. Cytochrome c oxidase measurements revealed higher incidence of disrupted mitochondrial membranes in the DHA and EPA dietary groups than in the FO and RO dietary groups. This disruption further affected the mitochondrial function, resulting in a marked reduction in FA β-oxidation capacities. The reduction in mitochondrial function and the increase in the activity of superoxide dismutase (SOD) in the DHA and EPA groups showed that high dietary dose of DHA and EPA resulted in oxidative stress (OS). The increased activity of caspase 3 in the high n-3 HUFA groups suggested the induction of apoptosis and increased incidence of cell death in WAT, which may be one of the factors explaining the lower fat percentage found in these groups.     

Fluctuations in pO2 in irradiated human melanoma xenografts

Several studies have demonstrated that untreated tumors may show significant fluctuations in tissue oxygen tension (pO(2)). Radiation treatment may induce changes in the tumor microenvironment that alter the pO(2) fluctuation pattern. The purpose of the present study was to investigate whether pO(2) fluctuations may also occur in irradiated tumors. A-07 human melanoma xenografts were irradiated with single doses of 0, 5 or 10 Gy. Fluctuations in pO(2) were recorded with OxyLite probes prior to irradiation and 24 and 72 h after the radiation exposure. Radiation-induced changes in the tumor microenvironment (i.e. blood perfusion and extracellular volume fraction) were assessed by dynamic contrast-enhanced magnetic resonance imaging. Seventy-two hours after 10 Gy, tumor blood perfusion had decreased to approximately 40% of that prior to irradiation, whereas the extracellular volume fraction had increased by approximately 25%. Fluctuations in pO(2) were seen in most tumors, irrespective of radiation dose and time after irradiation. The mean pO(2), the number of fluctuations around the mean pO(2), the number of fluctuations around threshold pO(2) values of 1, 2, 3, 5, 7 and 10 mmHg, and the amplitude of the fluctuations were determined for each pO(2) trace. No significant differences were detected between irradiated and unirradiated tumors. The results showed that pO(2) fluctuations may occur in irradiated tumors and that the pO(2) fluctuation pattern in A-07 tumors exposed to 5 or 10 Gy is similar to that in untreated tumors. Consequently, these doses did not induce changes in the tumor microenvironment that were sufficient to cause detectable alterations in the pO(2) fluctuation pattern.