Diversity array technology markers: genetic diversity analyses and linkage map construction in rapeseed (Brassica napus L.)

We developed Diversity Array Technology (DArT) markers for application in genetic studies of Brassica napus and other Brassica species with A or C genomes. Genomic representation from 107 diverse genotypes of B. napus L. var. oleifera (rapeseed, AACC genomes) and B. rapa (AA genome) was used to develop a DArT array comprising 11 520 clones generated using PstI/BanII and PstI/BstN1 complexity reduction methods. In total, 1547 polymorphic DArT markers of high technical quality were identified and used to assess molecular diversity among 89 accessions of B. napus, B. rapa, B. juncea, and B. carinata collected from different parts of the world. Hierarchical cluster and principal component analyses based on genetic distance matrices identified distinct populations clustering mainly according to their origin/pedigrees. DArT markers were also mapped in a new doubled haploid population comprising 131 lines from a cross between spring rapeseed lines ‘Lynx-037DH’ and ‘Monty-028DH’. Linkage groups were assigned on the basis of previously mapped simple sequence repeat (SSRs), intron polymorphism (IP), and gene-based markers. The map consisted of 437 DArT, 135 SSR, 6 IP, and 6 gene-based markers and spanned 2288 cM. Our results demonstrate that DArT markers are suitable for genetic diversity analysis and linkage map construction in rapeseed.

{5-Chloro-2-[(2-hy-droxy-benzyl-idene)amino]-phen-yl}(phen-yl)methanone

The title Schiff base compound, C₂₀H₁₄ClNO₂, adopts an E configuration about the azomethine bond. The phenol and chloro­benzene rings form dihedral angles of 84.71 (9) and 80.70 (8)°, respectively, with the phenyl ring and are twisted by 15.32 (8)° with respect to one another. The mol­ecular conformation is stabilized by an intra­molecular O—H⋯N hydrogen bond, which forms an S(6) ring motif. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming columns parallel to the a axis.

{5-Chloro-2-[(4-nitro-benzyl-idene)amino]-phen-yl}(phen-yl)methanone

The mol­ecule of the title Schiff base compound, C₂₀H₁₃ClN₂O₃, assumes an E configuration about the C=N bond. The aromatic rings of the nitro­benzene and chloro­benzene groups are twisted by 13.89 (13)° and form dihedral angles of 76.38 (13) and 84.64 (13)°, respectively, with the phenyl ring. In the crystal, mol­ecules are linked into chains parallel to the b axis by C—H⋯π inter­actions.

Multifunctional alginate microspheres for biosensing, drug delivery and magnetic resonance imaging

This research aims to develop and investigate a multifunctional implantable system capable of biosensing, drug delivery and magnetic resonance imaging (MRI) for continuous monitoring, controlled anti-inflammatory drug delivery and imaging, respectively. A glucose biosensor, diclofenac sodium (Diclo) and magnetic nanoparticles (MNP) were used as the biosensor component, anti-inflammatory agent and MRI contrast agent, respectively. MNP were synthesized by the co-precipitation technique and loaded with the sensor and drug components into alginate microspheres using a commercial droplet generator. The multifunctional system was then characterized using optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, vibrating sample magnetometry (VSM) and MRI. The MNP were found to be in the size range of 5-15 nm. The final system, comprising the biosensor, drug and MNP loaded inside alginate microspheres, was found to be in the size range of 10-60 μm. Biosensing studies indicated an excellent glucose response curve, with a regression coefficient of 0.974 (0-10mM of glucose, response time: 4 min). In vitro Diclo release shows that MNP loading in alginate microspheres increases the burst release percentage by 11-12% in both 60 and 10 μm particles. However, the duration of release for 85% drug release decreases with MNP loading by 7 and 6 days for 39 the 60 and 10 μm particles, respectively. Super-paramagnetism was confirmed by VSM, with 2.09 and 1.368 emu g(-1), respectively, for the 60 and 10 μm particles, with no hysteresis. MRI showed significant contrast for both sizes. The particles showed an excellent biocompatibility (>80%) for all combinations of formulations. The system shows a great potential for biosensing with concurrent drug delivery and visualization for biomedical applications.

Specialty choices of medical students and house officers in Karachi, Pakistan

Unerstanding patterns of career choices inmedicine is importnat for educators and policy-makers to plan the supply of specialists. This study analysed the career choices made by medical students and house officers in 2 private and 2 public medical schools in Karachi, Pakistan. An anonymous, self-administered and gynaecology were the 4 highest ranked specialties, with internal medicine ranked top as both the 1st and 2nd choice. Internal medicine was the 1st choice for significantly more students in public than private medical colleges (22.2% versus 1l4.9%). Students from private medical institutions chose a wider range of specialties than those from publicly-funded colleges. A high proportion of medical students and graduates in Karachi favour the same medical specialties, which may lead to saturation in those areas of specialization.

Excitation functions of α-particle induced reactions on enriched 123Sb and (nat)Sb for production of 124I

Excitation functions of (α,xn) reactions on 98.28% enriched (123)Sb and on (nat)Sb were measured from 9 to 40 MeV. The data could be described well in terms of statistical and precompound models using the code TALYS. The discrepancies in the literature data for the formation of (125)I and (126)I were solved. The nuclear reaction (123)Sb(α,3n)(124)I on an enriched target appears to be interesting for the production of (124)I (T(1/2)=4.18 d) over the energy range E(α)=42→32 MeV, its yield being 11.7 MBq/μAh. The levels of the radionuclidic impurities (125)I and (126)I amount to 1.8% and 0.6%, respectively. The use of (nat)Sb as target material for (124)I production is unsuitable due to the high level of (123)I impurity.

Evaluation of excitation functions of proton and deuteron induced reactions on enriched tellurium isotopes with special relevance to the production of iodine-124

Cross-section data for the production of medically important radionuclide (124)I via five proton and deuteron induced reactions on enriched tellurium isotopes were evaluated. The nuclear model codes, STAPRE, EMPIRE and TALYS, were used for consistency checks of the experimental data. Recommended excitation functions were derived using a well-defined statistical procedure. Therefrom integral yields were calculated. The various production routes of (124)I were compared. Presently the (124)Te(p,n)(124)I reaction is the method of choice; however, the (125)Te(p,2n)(124)I reaction also appears to have great potential.

Transient hypoxia induces ERK-dependent anti-apoptotic cell survival in endothelial cells

Ischemia-induced apoptosis of endothelial cells may contribute to tissue injury, organ failure, and transplantation rejection. However, little is known about survival mechanisms capable to counteract endothelial apoptosis. This study investigated the potential role of an endogenous anti-apoptotic response elicited by transient hypoxia, capable to avert ongoing apoptosis in endothelial cells. Experiments were carried out in three different types of cultured endothelial cells (human umbilical vein, pig aorta, and from rat coronary microvasculature). As a pro-apoptotic challenge endothelial cells were cultured in serum-free medium and subjected to hypoxia for 2 h. We found that transient hypoxia reduced caspase 3 activation within 1 h of hypoxia. Accordingly, the number of apoptotic cells was reduced after 24 h of reoxygenation. This was true for all three cell types analyzed. Analysis of Akt and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways revealed that hypoxia induced a transient activation of ERK 2 but not of Akt. ERK 2 phosphorylation preceded the phosphorylation of pro-apoptotic molecule Bad at Ser112, an inhibitory phosphorylation site specific for ERK. The protective effects of hypoxia regarding Bad phosphorylation, caspase 3 activation, and apoptosis were abolished by MEK 1/2 inhibitors, PD98059 or UO126, as well as by antisense oligonucleotides directed against ERK 1/2. Furthermore, inhibition of this pathway inhibited hypoxia-induced increase in mitochondrial membrane potential. The present study demonstrates that transient hypoxia induces a novel survival mechanism that protects endothelial cells against apoptosis. This endogenous process involves MEK/ERK-mediated inhibition of the pro-apoptotic molecule Bad and caspase 3.

Estimation of genetic distance between 10 maize accessions with varying response to different levels of soil moisture

Ten maize accessions (NC-9, A50-2, M-14, B-42, NC-3, T-7, N-48-1, B-34, USSR, and WFTMS) were studied to estimate the genetic distance on molecular level by random amplified polymorphic DNA. These accessions were selected on the basis of their variable responses against different levels of moisture. Twenty-five primers were used to test genetic diversity, of which 14 were observed to be polymorphic. Ninety-three loci were amplified; among these, 77 showed polymorphism and the other 16 were monomorphic. Primers A-13 and C-02 gave the most polymorphic bands, while primers A-01 and C-06 gave the fewest polymorphic bands. The genetic similarities of the 10 maize accessions ranged from 82.8 to 54.8%. Accessions USSR and WFTMS showed greatest similarity, and accessions M-14 and B-42 were found more dissimilar than the other accessions. On the basis of cluster analysis, these 10 accessions were classified in two major groups, A and B, and than further divided into sub-groups. The cluster analysis showed that accessions in the same group as well as in the sub-groups were similar in their physical and morphological characters, since the characters are controlled genetically.

Charged particle induced reaction cross section data for production of the emerging medically important positron emitter64Cu: A comprehensive evaluation

The radionuclide64Cu (T1/2=12.7 h) is an important non-standard positron emitter, suitable for combining PET imaging and targeted therapy. Its production in no-carrier-added form is doneviacharged particle induced reactions, and considerable amount of cross section data are available in the literature. We evaluated seven reactions, namely64Ni(p,n)64Cu,64Ni(d, 2n)64Cu,68Zn(p, αn)64Cu,66Zn(p, 2n)64Cu,64Zn(d, 2p)64Cu,66Zn(p, α)64Cu andnatZn(d,x)64Cu. Data analysis was generally limited up to about 25 MeV and the consistency check of experimental data was carried out using the nuclear model codes STAPRE, EMPIRE and TALYS. In a few cases experimental data were available up to 100 MeV; the consistency check in the high energy region was done only using the code TALYS. A statistical procedure (supported by nuclear model calculations) was then used to fit the data. The derived recommended sets of data, together with 95% confidence limits, are reported. The integral yields calculated from those data are also given. A critical comparison of the various production routes of64Cu is presented. The64Ni(p,n)64Cu reaction, utilizing a highly enriched target, is the method of choice.

Removal of silver and antimony radionuclides from low-level liquid radioactive waste of a research reactor through different scavenging precipitations

After upgrading the Pakistan Research Reactor-1, the amount of liquid waste and its increased radioactivity content necessitated a pre-disposal treatment to bring the activity down to disposal limits. Amongst several radionuclides in the waste, 110mAg and to some extent 124Sb were of our concern due to their higher production rate. Different possible treatment processes were considered for the treatment of low-salt, low-level liquid waste of the institute. Making use of insolubilities and scavenging properties of certain precipitates of metal ions, some experiments on the actual waste samples were performed for the decontamination of the piled up waste effluent. Suitable reagent(s) and the optimum doses were to be investigated for the treatment and conditioning of the wastewater. Different scavenging agents like ferric chloride, ferrous sulfate, stannous chloride, in situ precipitated manganese hydroxide and lanthanum nitrate were studied for the removal of these two radionuclides. Selectivity of Fe2+ and Fe3+ as scavengers for silver and antimony was investigated. Excellent Decontamination Factors (>1000) were obtained very cost effectively with some of the reagents tried. Based on these experiments, a working procedure making use of Fe(II) hydrous oxide scavenging precipitation for the chemical treatment of the waste effluent was optimized. These experiments are presented.

Effect of pesticide residues on health and blood parameters of farm workers from rural Gadap, Karachi, Pakistan

The samples were collected from 83 persons on 1 day (reading-I), 7 days (reading-II) and 30 days (reading-III) engaged in pesticide spraying in fourteen different fruit and vegetable farm stations located in the orchards of Gadap (rural area), Karachi-Pakistan. In the present study 26 workers out of 83 who were exposed to different pesticides (ie., cypermethrin, deltamethrin, polytrin-C, diazninon, monocrotophos, DDT and DDE) were compared with 25 healthy control persons. Different blood parameters were determined in comparison to control subjects. The results indicate some alterations in blood indices in allthe pesticide exposed persons, and only two persons from two different stations were affected severely and therefore their Hb, MCV MCHC, TLC, monocyte and neutrophil counts increased significantly. High lymphocyte count was noted in almost all the exposed persons. Platelets count was also found high in few persons but Hb, MCV, MCH, TLC, RBC and neutrophil counts significantly decreased in such persons. Exposure of multiple pesticides for prolong period has also affected the health of exposed persons and produced dermatological, hepatic, nephritic, respiratory and other clinical disorders reflecting the toxic effects of pesticides. Our findings indicate that indiscriminate use of pesticides in farming environments must be regularly assessed and farm workers must be trained for safe use of pesticides.

Genetic characterization of spoilage pseudomonads isolated from retail-displayed beef

AIM

This study genetically characterized Pseudomonas isolated from beef using the random amplification of polymorphic DNA (RAPD) method and correlate predominant genotypes with spoilage changes.

METHODS AND RESULTS

Pseudomonads were recovered from beef loins and steaks on days 0, 2, 4, 6, 8 and 10. A total of 309 pseudomonads were grouped into 50 RAPD types (>85% similarity). One major RAPD type contained 45% of the isolates comprising 71%, 45%, 31%, 35%, 50% and 37% of isolates from days 0, 2, 4, 6, 8 and 10, respectively, from steaks and 48% of the isolates recovered from beef loins. Nineteen RAPD types consisted of isolates that were shared between more than two sampling times, whereas the remaining 31 types were unique to one particular time.

CONCLUSIONS

A genetically diverse Pseudomonas population was present on the loins and steaks at each sampling time. Although pseudomonads associated with beef loins were transferred to the steaks prepared from it, a genetically diverse Pseudomonas population emerged during the retail display.

SIGNIFICANCE AND IMPACT OF THE STUDY

Information about the heterogeneous nature of Pseudomonas recovered from meat would help understanding the spoilage owing to predominant strains. The meat industry can use the knowledge to develop control strategies for prevalent spoilage strains.

Nanoscale assembly of amine functionalized colloidal iron oxide

We demonstrate a single-step facile approach for highly water stable assembly of amine-functionalized Fe(3)O(4) nanoparticles using thermal decomposition of Fe-chloride precursors in ethylene glycol medium in the presence of ethylenediamine. The average size of nanoassemblies is 40±1 nm, wherein the individual nanoparticles are about 6 nm. Amine functionalized properties are evident from FTIR, thermal and elemental analysis. The saturation magnetization and spin-echo r(2) of the nanoassemblies were measured to be 64.3 emu/g and 314.6 mM(-1)s(-1), respectively. The higher value of relaxivity ratio (r(2)/r(1)=143) indicates that nanoassemblies are a promising high efficiency T2 contrast agent platform.