牛体外受精胚胎衍生干细胞能力影响因素的研究

以牛卵巢卵母细胞体外受精获取囊胚期胚胎，比较体外受精牛胚胎不同获取内细胞团的方法和不同培养液对体外培养胚胎干细胞能力的影响。结果表明，囊胚期胚胎不除去透明带而直接培养产生胚胎干细胞，初次克隆率为55％；胰酶法去透明带分离的内细胞团（ICM）培养产生胚胎干细胞，初次克隆率为90％。免疫外科法去透明带分离的ICM在4种不同的培养液中，初次克隆率分别为16．4％、11．5％、21．8％、18．2％，但是其分离的ICM经传代后形成的衍生细胞不易发生分化，经过4～6代的传代，仍然保持其完整的形态，说明免疫外科法是一种理想的牛ICM分离法，培养液为D20＋LIF（40ng／mL）可用于牛胚胎干细胞培养。     

Viruses of pome fruit trees in Syria

A survey was conducted to evaluate the sanitary status of pome fruit trees in Syria during spring 2003 and 2004 in 6 governorates: Damascus, Al-Qunaitara and Al-Sweida (Southern region), Homs and Hama (Central region) and Latakia (Costal Western region), as the main production areas of pome fruits. Leaf samples from 1077 apples, 54 pears and 14 quince were collected and tested for the presence of Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) and Apple mosaic virus (ApMV) in 70 commercial orchards and 3 varietal collections by ELISA. Results showed that the virus infection rates were 34 and 2% in apple and pear, respectively. Quince trees were found to be virus tested free. ACLSV was prevailing on apple with 34%, whereas ASGV and ApMV were found in 2 and 0.2% of tested trees, respectively. Pear trees were infected only with ACLSV (2%). 21 apples and 15 pears representative budwood samples were indexed by grafting on the following indicators: (i) Malus pumila cvs. Virginia Crab and Radiant for apple and (ii) M. pumila cv. V. Crab and Pyrus communis cv. Nouveau Poiteau for pear. The virus infection rates by woody indexing were much higher than ELISA, Apple stem pitting virus (ASPV) and ASGV were found in 86 and 82% of apple tested samples, whereas they were 80 and 60% of pear tested samples, respectively. Additional RT-PCR testing carried out for a limited number of samples confirmed the high incidence of ACLSV ASPV, ASGV and the presence of ApMV. This is the first report on pome fruit viruses in Syria, indicating an unsatisfactory sanitary status of the industry. As a consequence, a certification program is recommended for producing locally healthy propagating material.     

Partial characterization of phytoplasmas associated with lettuce and wild lettuce phyllodies in Iran

Phytoplasmas associated with lettuce phyllody (LP) and wild lettuce phyllody (WLP) in southern Iran were partially characterized by molecular analyses and host-range studies. Agents of both diseases were transmitted by Neoaliturus fenestratus , a leafhopper colonizing lettuce and wild lettuce, to lettuce, wild lettuce, sowthistle and periwinkle, but not to safflower, sunflower, calendula and sesame. Both phytoplasmas induced bud proliferation, virescence, phyllody and witches' broom in infected plants. Total DNA extracted from infected lettuce and wild lettuce or from vector tissues was subjected to PCR using phytoplasma-specific primer pair P1/P7 or nested PCR using P1/P7 followed by R16F2n/R16R2. PCR product of nested PCR (1·2 kbp) was subjected to restriction fragment length polymorphism (RFLP). RFLP analysis of nested PCR product identified the LP, WLP and N. fenestratus -associated phytoplasmas as members of the pigeon pea witches' broom group, 16SrIX. Phylogenetic analysis of the 16S rRNA gene sequence also clustered LP and WLP phytoplasmas with other known members of the 16SrIX group. While no significant differences could be detected between LP and WLP phytoplasmas, both isolates differed from Lebanese wild lettuce phyllody in molecular properties.     

Concentrations of constitutive alk(en)ylresorcinols in peel of commercial mango varieties and resistance to postharvest anthracnose

Mature green mango fruits of commercially important varieties were screened to investigate the levels of constitutive antifungal compounds in peel and to assess anthracnose disease after inoculation with Colletotrichum gloeosporioides. High-pressure liquid chromatography was used to quantify the levels of 5-n-heptadecenylresorcinol and 5-n-pentadecylresorcinol in the peel extracts. The fruit peel of the varieties ‘Kensington Pride’ and ‘Keitt’ were observed to have the highest levels of both 5-n-heptadecenylresorcinol (107.3–123.7 and 49.9–61.4 μg/g FW, respectively) and 5-n-pentadecylresorcinol (6.32–7.99 and 3.30–6.05 μg/g FW, respectively), and the fruits of the two varieties were found to have some resistance to postharvest anthracnose. The varieties ‘Kent’, ‘R2E2’, ‘Nam Doc Mai’, ‘Calypso’ and ‘Honey Gold’ contained much lower concentrations of resorcinols in their peel and three of these varieties were found to be more susceptible to anthracnose. Concentrations of 5-n-heptadecenylresorcinol were significantly lower at the ‘sprung’ and ‘eating ripe’ stages of ripening compared to levels at harvest. Concentrations of 5-n-pentadecylresorcinol did not differ significantly across the three stages of ripening. The levels of these two resorcinols were found to be strongly inter-correlated (P<0.01, r²=0.71), with concentrations of 5-n-heptadecenylresorcinol being an average 18 times higher than those of 5-n-pentadecylresorcinol. At the ‘eating ripe’ stage, significant relationships were observed between the concentrations of each type of alk(en)ylresorcinol and anthracnose lesion areas following postharvest inoculation, P<0.001, r²= 0.69 for 5-n-pentadecylresorcinol, and P<0.001, r²= 0.44 for 5-n-heptadecenylresorcinol.     

Pharmacokinetics and tissue residues of kitasamycin in healthy and diseased broilers

The pharmacokinetics of kitasamycin after intravenous and oral administration in a dose of 300 mg/kg b.wt. was studied in 18 healthy and 18 Salmonella gallinarum naturally infected chickens. The tissue residue of the studied antibiotic was estimated in 36 normal chickens when it was given orally for 7 successive days. Therapeutic level of kitasamycin was achieved after 15 minutes and persisted for 20-22 hours after its oral administration. Higher serum kitasamycin concentrations were recorded in Salmonella gallinarum infected chickens. The elimination half-life of kitasamycin calculated after single intravenous injection was 9.03 hours in diseased chickens corresponding to 3.74 hours in healthy birds. The body clearance was significantly reduced in diseased chickens (23.86 ml/kg/min) when compared to that in normal ones (62.03 ml/kg/min). Kitasamycin treated broilers should not be slaughtered before 3 days from the last dose as it was detected only in bile and caecum at that time but not in edible tissues.     

Pathogenicity of peste des petits ruminants virus isolated from Egyptian goats in Egypt

2 Egyptian goats and Boscat rabbits were experimentally inoculated with peste des petits ruminants (PPR) local Egyptian strain (PPR, Egypt 87). The inoculated animals contracted the disease with minor clinical manifestations, accompanied by rise of neutralizing antibodies to PPR virus. Virus was isolated from ocular and nasal secretions, buffy coat, spleen, and liver. No contact infection was observed between inoculated and healthy goats.     

Polyhydric alcohol liquefaction of some lignocellulosic agricultural residues

Liquefaction of bagasse and cotton stalks was conducted by using polyhydric alcohols (polyethylene glycol PEG#400 and glycerin) in the presence of sulfuric acid (SA) as a catalyst. The effects of different liquefaction conditions, such as ratio raw material/liquefying solvent, effect of PEG#400/glycerin, acid concentration, liquefaction temperature and time on the liquefaction yield have been investigated. The hydroxyl and acid numbers for some liquefied samples were also determined. The results showed that the minimum residue content was obtained at 1/5 raw material to liquefying solvent. PEG#400 alone is not favoured as liquefying solvent as it gives ∼19% residual content for bagasse and ∼22% for cotton stalks at the optimum studied reaction conditions. Replacing 10% of PEG#400 with glycerin as well as increasing the SA concentration, liquefaction temperature or time, decreased the amount of residue for both bagasse and cotton stalks to less than 10%. The hydroxyl number of the produced polyols slowly decreased from 253 to 223 mg KOH/g on extending the reaction time till 120 min and the residual polyols prevented re-condensation of the liquefied components. It seems that this system can be applied on various types of lignocellulosic agricultural residues.     

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Mycological studies on the wood-borerstromatium fulvum vill. (Col., cerambycidae) infestingcasuarina glauca (casuarinaceae) III. Effect of inoculation with the fungal isolates on lignin and extractive content of wood

Wood specimens of Casuarina glauca were inoculated withChaetomium spp. andTrichoderma spp., alone or in combination in the presence or abscence of larvae ofStromatium fulvum. All fungal inoculates caused deterioration to the lignin of the wood specimens. The infestation with larvae alone caused the same. The extractive content decreased to a little extent.

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Zusammenfassung Bäume von Casuarina glauca wurden mitChaetomium spp. undTrichoderma spp. inokuliert, allein oder in Kombination sowie in Abwesenheit oder Gegenwart der Larven vonStromatium fulvum. Alle Pilz-Inokulate verusachten einen Abbau von Lignin in den Bäumen. Denselben Effekt hatte die Tätigkeit vonStromatium-Larven ohne Pilz-Inokulation. Der extraktive Anteil verminderte sich nur wenig.

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