Variation in Weed Seed Fate Fed to Different Holstein Cattle Groups

Weed seeds may maintain their viability when passing through the digestive tract of cattle and can be therefore dispersed by animal movement or the application of manure. Whether different cattle types of the same species can cause differential weed seed fate is largely unknown to us particularly under non-grazed systems similar to Holstein-Friesian dairy farming. We investigated the effect on the seed survival of four weed species in the digestive tracts of four groups of Holstein cattle: lactating cows, feedlot male calves, dry cows and growing heifers. The weed species used were Cuscuta campestris, Polygonum aviculare, Rumex crispus and Sorghum halepense. Cattle excretion was sampled for recovery and viability of seeds at four 24 hourly intervals after seed intake. The highest seed recovery occurred two days after seed intake in all cattle groups. Averaged over weed species, dry and lactating cows had the lowest and highest seed recovery of 36.4% and 74.4% respectively. No significant differences were observed in seed recovery of the four weed species when their seeds were fed to dry cows. Based on a power model fitted to seed viability data, the estimated time to 50% viability loss after seed intake, over all cattle groups ranged from 65 h (R. crispus) to 76 h (P. aviculare). Recovered seeds from the dung of feedlot male calves showed the highest mortality among cattle groups. Significant correlation was found between seed viability and ruminal pH (r = 0.86; P<0.05). This study shows that management programs aiming to minimize weed infestation caused by livestock should account for the variation amongst cattle groups in seed persistence. Our findings can be used as a guideline for evaluating the potential risk of the spread of weeds via the application of cattle manure.     

Evaluating the bone regeneration in calvarial defect using osteoblasts differentiated from adipose-derived mesenchymal stem cells on three different scaffolds: an animal study

The aim of this study was to investigate the effect of three different scaffolds on the viability and differentiation of adipose-derived mesenchymal stem cells (ADMSCs) to osteoblast for bone regeneration of calvarial defect in rabbit model. Adipose was harvested from the nape of 12 rabbits by direct surgery or hollow-tip cannula. Two standardized circular calvarial defects (case and control), 8 mm in diameter each, were created in all the animals. The animals were divided into 3 different groups. In group 1 (G1), the defect was filled with polyamide + ADMSC. In group 2, poly lactic-co-glycolic acid + ADMSC was used. In group 3, decellularized amniotic membrane + ADMSC was applied. In the control defect, the non-seeded scaffolds were applied for filling the defect. Decellularized pericardial scaffolds were used as a membrane on the scaffolds. The animals were euthanized 2, 4, and 8 weeks of operation and new bone formation was assessed by different analyses. Immunohistochemical (IHC) staining with osteopontin and osteocalcin antibodies was also performed. After 2 weeks of wound healing, minimal bone regeneration was detected in all groups. Almost complete defect closure was observed in all experimental groups after 8 weeks of operation, with the greatest defect closure in the animals treated with polyamide scaffolds as compared to biopsies obtained from control defects and other experimental groups. The maximal tensile load was higher in G1, 4 and 8 weeks postoperatively, suggesting the usefulness of polyamide + ADMSC for bone regeneration in calvarial defects. Results of the IHC staining demonstrated a significant difference between seeded and non-seeded scaffold in both short- and long-term follow-ups (P < 0.05). In addition, a significant difference was observed in enhancement of IHC staining of both markers in polyamide group (seeded or non-seeded) 4 and 8 weeks postoperatively in comparison with other scaffolds. It was concluded that bone regeneration in critical calvarial defect was more successful in seeded polyamide.     

Structure of amplified DNA in different Syrian hamster cell lines resistant to N-(phosphonacetyl)-L-aspartate.

Syrian hamster cell lines selected in multiple steps for resistance to high levels of N-(phosphonacetyl)-L-aspartate (PALA) contain many copies of the gene coding for the pyrimidine pathway enzyme CAD. Approximately 500 kilobases of additional DNA was coamplified with each copy of the CAD gene in several cell lines. To investigate its structure and organization, we cloned ca. 162 kilobases of coamplified DNA from cell line 165-28 and ca. 68 kilobases from cell line B5-4, using a screening method based solely on the greater abundance of amplified sequences in the resistant cells. Individual cloned fragments were then used to probe Southern transfers of genomic DNA from 12 different PALA-resistant mutants and the wild-type parents. A contiguous region of DNA ca. 44 kilobases long which included the CAD gene was amplified in all 12 mutants. However, the fragments cloned from 165-28 which were external to this region were not amplified in any other mutant, and the external fragments cloned from B5-4 were not amplified in two of the mutants. These results suggest that movement or major rearrangement of DNA may have accompanied some of the amplification events. We also found that different fragments were amplified to different degrees within a single mutant cell line. We conclude that the amplified DNA was not comprised of identical, tandemly arranged units. Its structure was much more complex and was different in different mutants. Several restriction fragments containing amplified sequences were found only in the DNA of the mutant cell line from which they were isolated and were not detected in DNA from wild-type cells or from any other mutant cells. These fragments contained novel joints created by rearrangement of the DNA during amplification. The cloned novel fragments hybridized only to normal fragments in every cell line examined, except for the line from which each novel fragment was isolated or the parental population for that line. This result argues that "hot spots" for forming novel joints are rare or nonexistent.     

Transplantation of stem cells from human exfoliated deciduous teeth for bone regeneration in the dog mandibular defect

AIM: To investigate the effect of stem cells from human exfoliated deciduous teeth(SHED) transplanted for bone regeneration in the dog mandibular defect.METHODS: In this prospective comparative study, SHEDs had been isolated 5 years ago from human exfoliated deciduous teeth. The undifferentiated stem cells were seeded into mandibular bone through-andthrough defects of 4 dogs. Similar defects in control group were filled with cell-free collagen scaffold. After 12 wk, biopsies were taken and morphometric analysis was performed. The percentage of new bone formation and foreign body reaction were measured in each case. The data were subject to statistical analysis using the Mann-Whitney U and Kruskalwalis statistical tests. Differences at P 0.05 was considered as significant level.RESULTS: There were no significant differences between control and SHED-seeded groups in connective tissue(P = 0.248), woven bone(P = 0.248) and compact bone(P = 0.082). There were not any side effects in transplanted SHED group such as teratoma or malignancy and abnormalities in this period.CONCLUSION: SHEDs which had been isolated and characterized 5 years ago and stored with cryopreservation banking were capable of proliferation and osteogenesis after 5 years, and no immune response was observed after three months of seeded SHEDs.     

Angiogenesis Is Induced and Wound Size Is Reduced by Electrical Stimulation in an Acute Wound Healing Model in Human Skin

Angiogenesis is critical for wound healing. Insufficient angiogenesis can result in impaired wound healing and chronic wound formation. Electrical stimulation (ES) has been shown to enhance angiogenesis. We previously showed that ES enhanced angiogenesis in acute wounds at one time point (day 14). The aim of this study was to further evaluate the role of ES in affecting angiogenesis during the acute phase of cutaneous wound healing over multiple time points. We compared the angiogenic response to wounding in 40 healthy volunteers (divided into two groups and randomised), treated with ES (post-ES) and compared them to secondary intention wound healing (control). Biopsy time points monitored were days 0, 3, 7, 10, 14. Objective non-invasive measures and H&E analysis were performed in addition to immunohistochemistry (IHC) and Western blotting (WB). Wound volume was significantly reduced on D7, 10 and 14 post-ES (p = 0.003, p = 0.002, p<0.001 respectively), surface area was reduced on days 10 (p = 0.001) and 14 (p<0.001) and wound diameter reduced on days 10 (p = 0.009) and 14 (p = 0.002). Blood flow increased significantly post-ES on D10 (p = 0.002) and 14 (p = 0.001). Angiogenic markers were up-regulated following ES application; protein analysis by IHC showed an increase (p<0.05) in VEGF-A expression by ES treatment on days 7, 10 and 14 (39%, 27% and 35% respectively) and PLGF expression on days 3 and 7 (40% on both days), compared to normal healing. Similarly, WB demonstrated an increase (p<0.05) in PLGF on days 7 and 14 (51% and 35% respectively). WB studies showed a significant increase of 30% (p>0.05) on day 14 in VEGF-A expression post-ES compared to controls. Furthermore, organisation of granulation tissue was improved on day 14 post-ES. This randomised controlled trial has shown that ES enhanced wound healing by reduced wound dimensions and increased VEGF-A and PLGF expression in acute cutaneous wounds, which further substantiates the role of ES in up-regulating angiogenesis as observed over multiple time points. This therapeutic approach may have potential application for clinical management of delayed and chronic wounds.     

Chemometrics models for overcoming high between subject variability: applications in clinical metabolic profiling studies

In human metabolic profiling studies, between-subject variability is often the dominant feature and can mask the potential classifications of clinical interest. Conventional models such as principal component analysis (PCA) are usually not effective in such situations and it is therefore highly desirable to find a suitable model which is able to discover the underlying pattern hidden behind the high between-subject variability. In this study we employed two clinical metabolomics data sets as the testing grounds, in which such variability had been observed, and we demonstrate that a proper choice of chemometrics model can help to overcome this issue of high between-subject variability. Two data sets were used to represent two different types of experiment designs. The first data set was obtained from a small-scale study investigating volatile organic compounds (VOCs) collected from chronic wounds using a skin patch device and analysed by thermal desorption-gas chromatography-mass spectrometry. Five patients were recruited and for each patient three sites sampled in triplicate: healthy skin, boundary of the lesion and top of the lesion, the aim was to discriminate these three types of samples based on their VOC profile. The second data set was from a much larger study involving 35 healthy subjects, 47 patients with chronic obstructive pulmonary disease and 33 with asthma. The VOCs in the breath of each subject were collected using a mask device and analysed again by GC–MS with the aim of discriminating the three types of subjects based on breath VOC profiles. Multilevel simultaneous component analysis, multilevel partial least squares for discriminant analysis, ANOVA-PCA, and a novel simplified ANOVA-PCA model—which we have named ANOVA-Mean Centre (ANOVA-MC)—were applied on these two data sets. Significantly improved results were obtained by using these models. We also present a novel validation procedure to verify statistically the results obtained from those models.     

Monitoring of arsenic in drinking water of high schools and assessment of carcinogenic health risk in Multan,Pakistan

Abstract

This study was performed to measure arsenic (As) contents in groundwater/drinking water of high schools and its effects on human health. Chronic daily intake, hazardous quotient (HQ), carcinogenic risk (CR), hazardous index (HI), and carcinogenic indices (CI) for oral and dermal exposure to arsenic were calculated. Samples were taken from high schools in four tehsils of Multan. As contents ranged from 3.25 to 184?µg/l and 99% samples exceeded World Health Organization safe limit (10?µg/l). HQ for Multan city (1.70) and for Multan Saddar (1.38) exceeded USEPA permissible toxic risk value (1.0). CR in four tehsils for oral (0.0001–0.0003) and dermal exposure (0.0000049–0.000011) exceeded USEPA limit (10^?6). HI for tehsil Multan city (1.75) and Multan Saddar (1.42) exceeded the limit (1.0). CI for four tehsils ranged from 0.00022 to 0.0008 exceeding USEPA limit (10^?6) indicating high chronic and carcinogenic health risk to exposed population. Results indicated that groundwater of district Multan is not fit for human consumption due to excessive arsenic contamination. It invites attention of water supplying agency and educational authorities to take steps for provision of arsenic free safe drinking water to students and local area peoples.