A new strategy for complete identification of sea buckthorn cultivars by using random amplified polymorphic DNA markers.

DNA fingerprinting is both a popular and important technique with several advantages in plant cultivar identification. However, this technique has not been used widely and efficiently in practical plant identification because the analysis and recording of data generated from fingerprinting and genotyping are tedious and difficult. We developed a novel approach known as a cultivar identification diagram (CID) strategy that uses DNA markers to separate plant individuals in a more efficient, practical, and referable manner. A CID was manually constructed and a polymorphic marker was generated from each polymerase chain reaction for sample separation. In this study, 67 important sea buckthorn cultivars cultivated in China were successfully separated with random amplified polymorphic DNA markers using the CID analysis strategy, with only seven 11-nucleotide primers employed. The utilization of the CID of these 67 sea buckthorn cultivars was verified by identifying 2 randomly chosen groups of cultivars among the 67 cultivars. The main advantages of this identification strategy include fewer primers used and separation of all cultivars using the corresponding primers. This sea buckthorn CID was able to separate any sea buckthorn cultivars among the 67 studied, which is useful for sea buckthorn cultivar identification, cultivar-right-protection, and for the sea buckthorn nursery industry in China.

Race Dynamics, Diversity, and Virulence Evolution in Puccinia striiformis f. sp. tritici, the Causal Agent of Wheat Stripe Rust in China from 2003 to 2007.

Stripe (or yellow) rust caused by Puccinia striiformis f. sp. tritici is the most destructive foliar disease of wheat in China. The pathogen populations were analyzed for virulence evolution, complexity, phenotypic dynamics, and diversity on temporal and spatial bases. A total of 41 races were identified and characterized from 4,714 stripe rust isolates collected during 2003 through 2007 from wheat growing areas in 15 provinces in China. The races were based on avirulence/virulence patterns to 19 differential host genotypes. Chinese stripe rust population exhibited high diversity with a complex virulence structure. Comparisons using the relative Shannon's index indicated that some differences in the richness and evenness of races were present in pathogen populations within years and between regions despite a national tendency to reduced diversity over time. A noticeably increased frequency of race CYR33 (Chinese yellow rust 33) with virulence for YrSu was the major virulence change recorded in this study compared to the results on an annual basis. Isolates of Puccinia striiformis f. sp. tritici from different regions showed differences in the composition of races, distribution frequency, and diversity. The uneven distribution of major races and comparatively greater diversity in the Northwest and Southwest regions than that in the Huang-Huai-Hai region suggest that long-distance migrations of the pathogen occur from one or more over-summering areas eastward into over-wintering areas. This supports the hypothesis that southern Gansu and northwestern Sichuan comprises a "center of origin for virulence". Mutation of virulence or avirulence for host resistance in the stripe rust fungus may be the basic cause of the occurrence of new virulent types. The subsequent dominance of certain races will vary with parasitic fitness and the opportunities to be selected through large-scale cultivation of varieties with matching resistance genes. Implications of the center of origin for virulence variation and diversity in the pathogen population and an alternative strategy for limiting virulence evolution are discussed.

[Chromosomal location and molecular marker of resistance gene to Puccinia striiformis west. in Leymus mollis Trin. Hara].

The hybrid wheat line, 93784 is a stable line selected from progenies of Leymus molli Trin. Hara x common wheat, which shows a very high level of resistance to yellow rust. The results of GISH using genomic DNA of Leymus mollis as probe indicated that the 93784 was a wheat-Leymus mollis small segment translocation line, and the translocated alien chromosome fragment were located on a pair of short arm terminals of what chromosomes. Using this translocation line, we established F2 segregation population and identified its yellow rust resistance in adult stage. Genetic analysis suggested that the yellow rust resistance of 93784 was controlled by a single gene. The gene was located on the translocated chromosome segments of Leymus mollis. We called it YrLm. By AFLP analysis with Taq I (T1-T4)/Pst I (P1-P6) primes in individuals of F2 segregation population and their susceptive and resistant parents, we screened a molecular marker that linked to yellow rust resistance gene YrLm. We also cloned and sequenced the molecular marker. The length of the marker is 205 bp, named P1T(3)205.

Effects of different kinds of stretch on voltage-dependent calcium current in antrial circular smooth muscle cells of the guinea-pig.

In order to elucidate the effect of membrane stretch on ionic currents, we employed the whole-cell patch-clamp technique to investigate the effects of different kinds of stretch on voltage-dependent calcium currents in antrial circular smooth muscle cells of the guinea-pig. The membrane stretch induced by superfusing the smooth muscle cells with hyposmotic bath solution enhanced voltage-operated calcium current and activated inward holding current. The increase in calcium current occurred within 1 minute of superfusion and the sustained inward holding current was slowly activated after prominent cell swelling. Voltage-dependent calcium currents (Ica) were significantly increased by membrane stretch which was induced by cell swelling and cell inflation, but was not affected by direct longitudinal stretch (110 130%) using two electrodes. The results suggest that the cell membrane stretch can increase voltage-dependent calcium channel activity and the effect of stretch on calcium channels was related to the membrane tension and/or the direction of membrane stretch.

Therapy of pediatric AIDS.

Therapy of pediatric AIDS utilizes antiretroviral compounds; antibiotic, antifungal, and antiparasitic agents; and both active and passive immunization in a multifactorial approach. Currently, newly diagnosed pediatric AIDS cases are acquired predominantly through vertical transmission from HIV-infected mothers. Pediatric AIDS research is focused on strategies to prevent vertical transmission of HIV infection as well as therapy against opportunistic and progressive HIV disease. Zidovudine remains first-choice therapy for HIV infection and can reduce the rate of vertical transmission of HIV. Didanosine is also approved to treat HIV infection in pediatric AIDS. Other reverse transcriptase inhibitors are under investigation as alternative or combination therapies because of HIV resistance to zidovudine and didanosine. Alternative therapies for opportunistic infections are being investigated. Passive immunity with intravenous immunoglobulin is being reevaluated to determine efficacy in combination with other therapies. Finally, vaccination against usual childhood diseases with standard immunization schedules produces limited immunity, and alternative vaccination protocols warrant further investigation.

[IgE and IgE-mediated immunoreaction in the pathogenesis of human cysticercosis].

Total IgE, specific IgE and histamine in sera from 35 documented cases of cysticercosis and 30 transfusion donors were measured and mast cell degranulation test was performed. Total IgE levels (730.61 U/ml), the positive rate of specific IgE (85.7%), histamine levels (5.3 micrograms/ml) and the positive rate of mast cell degranulation (42.9%) of the patients were found to be significantly higher than those of the normal group (P less than 0.01). The results suggested that the antigen of Cysticercus cellulosae could induce IgE production and mast cell degranulation, resulting in the release of histamine. It was, therefore, deemed that the IgE and IgE-mediated immunoreaction might be involved in the pathogenesis of human cysticercosis.

The effect of a telephone family assessment intervention on the functional health of patients with elevated family stress.

A randomized trial of a telephone family assessment intervention was conducted during a 2.5 month period on 224 ambulatory primary care patients, aged 18-49 years, who were selected according to self-report of elevated family stress levels. Family physicians conducted telephone interviews to collect information from patients on their supportive and stressful family members. The working hypothesis was that this process would lead to reduction in the patient's family stress and to improvement in family support and personal health status. Patients reported that the intervention caused them to think about their family support and helped them to feel better. Comparison of family factor and functional health scores before and after intervention also indicated a limited beneficial effect, but only for a small subset of black patients. These results suggest that the telephone family assessment alone is inadequate as an intervention and should be strengthened to include professional assistance to patients for the family problems that are identified by the assessment.

Associations among family support, family stress, and personal functional health status.

The self-reported family support and stress of 249 ambulatory adult patients, aged 18-49 years, were studied relative to their self-reported functional health. Support from family members was found to be related positively with emotional function. Stress from family members was associated negatively with symptom status, physical function, and emotional function. Patients' severity of illness was related negatively to their symptom status, physical function, and social function, but not to their emotional function. During the study a new self-report instrument, the Duke Social Support and Stress Scale (DUSOCS), was developed to measure family and non-family support and stress. Also, a new chart audit methodology, the Duke Severity of Illness Scale (DUSOI), was designed to assess severity in the ambulatory setting. Reliability and validity of the DUSOCS and the DUSOI were supported. The importance of the patient's perception of health and its family determinants is emphasized.

Treatment of lower urinary tract infections with single-dose trimethoprim-sulfamethoxazole.

Two hundred three women from a primary care medical practice with symptoms of lower urinary tract infection and positive urine cultures were treated with trimethoprim-sulfamethoxazole. One hundred eleven women received a single dose and 92 were treated for ten days. Cure rates were 87 percent and 89 percent, respectively, one week after therapy. A narrow 95 percent confidence interval for the difference between the two cure rates (.02 +/- .09) suggests the treatments are equally effective. Patients were followed by chart audit and a self-reporting questionnaire. No difference in recurrence rates was found between the two groups six months after therapy. Single-dose trimethoprim-sulfamethoxazole is as effective as ten-day treatment in women with symptoms suggestive of lower urinary tract infection and has no greater relapse rate.