[Research progress on the burden of respiratory syncytial virus infection in the elderly].

Human Respiratory Syncytial Virus (HRSV) is a serious threat to the population health. The elderly are one of the susceptible populations. The prevalence of HRSV in the elderly is generally higher than that in other age groups except children, which has gradually attracted attention in recent years. This paper reviewed the prevalence, common complications and major complications of HRSV in the elderly, briefly expounded the economic burden of HRSV infection, and proposed that attention should be paid to the disease burden of the elderly after HRSV infection, timely treat common complications, so as to reduce the occurrence of adverse survival outcomes and provide scientific evidence for the prevention and control of HRSV infection in the elderly.

[Evaluation of the psychological feature and quality of life in outpatients with somatic symptoms disorder in a general hospital].

Objective: To explore the psychological features and quality of life in outpatients with somatic symptoms disorder in a general hospital. Methods: This cross-sectional study was conducted from 2014-05 to 2015-06. Patients diagnosed with major depressive disorder (MDD) and somatic symptoms disorder (SSD) were recruited from psychological outpatient department, and patients with peptic ulcer (PU) / reflux esophagitis (RE) were recruited from Gastroenterology. Depression scale of the patient health questionnaire (PHQ-9), Generalized Anxiety Disorder 7-item scale (GAD-7), Toronto Alexithymia scale (TAS), 12-item Short Form Health Survey (SF-12), items from Somatoform Disorder Screening Questionnaire were employed to evaluate the severity of depression, anxiety, alexithymia, quality of life, health care use and subjective feelings. Results: Scores of PHQ-9 (10±6), GAD-7 (8±5), TAS (74±7) in patients with SSD were significantly higher than PU/RE patients (5±4, 5±4, 71±8, respectively), and the physical component summary (PCS) (40±8) and mental component summary (MCS) (37±10) of SSD patients were much lower than PU/RE (PCS 45±6, MCS 47±9) (P<0.01). No significant difference was found in the scores of PHQ-9, GAD-7, MCS-12, TAS between SSD and MDD group, but PCS-12 score of SSD group was much lower than that of MDD (P=0.017). Patients of SSD had more visits, more impact on life and longer duration of disorder. Multiple linear regression found that PHQ-9 score, subject feeling that life quality was affected were significant influential factors of PCS (F=14.600, P=0.001), and PHQ-9 score, occupation and ability to distinct emotion and physical feelings were significant influential factors of MCS (F=28.022, P=0.001). Conclusions: The SSD patients in a general hospital suffer from somatic symptoms and emotional distress, and quality of life is affected significantly. Clinicians should thoroughly evaluate patients according to bio-psycho-social aspects and give intervention individually.

Parental influences on weight-related health behaviors in western and eastern cultures.

BACKGROUND: Excessive bodyweight contributes to a myriad of risk factors for chronic diseases, and multiple reports have demonstrated that parents influence the development of their children's behaviors that contribute to bodyweight. However, studies that include considerations for cultural influences are limited, and methodology that considers direct reports from young adults and their parents across cultures does not exist. METHODS: A sample of young adults (N = 327) and their parents in the U.S. and in China were recruited and completed a series of questionnaires in two cycles (2010 and 2014). With correlation and multiple regression analyses, parents' characteristics, behaviors, and parental authority styles were examined and compared to weight-related health behaviors and bodyweight of their young-adult children. Additionally, similarities and differences of parental influences between the two cultures were explored. RESULTS: Parents' body mass indexes (BMIs) and dietary behaviors were positively associated with those of their young adult children in the mixed-culture sample (P < .001 for both). When controlling for gender, at high levels of authoritarian and permissive parental authority, the relationships between young adults' and their parents' BMIs were negative for U.S. participants and positive for Chinese participants (P < .05 for both). Further, at high levels of authoritarian parenting, the relationship between young adults' and their parents' dietary consumption behaviors was negative for U.S. participants and positive for Chinese participants (P < .001). CONCLUSIONS: This study provides evidence that the development of life-long health behaviors that contribute to BMI are significantly influenced by parents' behaviors and parenting styles. Moreover, an interaction of parental characteristics and cultural norms is indicated.

Zinc treatment increases the titre of 'Candidatus Liberibacter asiaticus' in huanglongbing-affected citrus plants while affecting the bacterial microbiomes.

AIMS: Huanglongbing (HLB)-affected citrus often display zinc deficiency symptoms. In this study, supplemental zinc was applied to citrus to determine its effect on Candidatus Liberibacter asiaticus (Las) titre, HLB symptoms, and leaf microbiome. METHODS AND RESULTS: HLB-affected citrus were treated with various amounts of zinc. The treatments promoted Las growth and affected microbiomes in citrus leaves. Phylochip(™) -based results indicated that 5475 of over 50 000 known Operational Taxonomic Units (OTUs) in 52 phyla were detected in the midribs of HLB-affected citrus, of which Proteobacteria was the most abundant, followed by Firmicutes and Actinobacteria. In comparison, the microbiomes of zinc-treated diseased plants had overall more OTUs with higher amounts of Proteobacteria, but decreased percentages of Firmicutes and Actinobacteria. In addition, more OTUs of siderophore-producing bacteria were present. Only zinc-sensitive Staphylococcaceae had higher OTU's in the diseased plants without zinc treatments. CONCLUSIONS: Although HLB-affected citrus appear zinc deficient, zinc amendments increased the pathogen levels and shifted the microbiome. SIGNIFICANCE AND IMPACT OF THE STUDY: HLB is currently the most devastating disease of citrus worldwide. Zinc is often applied to HLB-affected citrus due to zinc deficiency symptoms. This study provided new insights into the potential effects of zinc on HLB and the microbial ecology of citrus.

Characterization and Antibacterial Activity of Oil-In-Water Nano-Emulsion Formulation Against Candidatus Liberibacter asiaticus.

Nano-emulsion is a promising delivery system for increasing pesticide use and enhancing the therapeutic efficiency against pathogens. The pathogen Candidatus Liberibacter asiaticus (Las) that causes destructive citrus huanglongbing (HLB) resides in citrus phloem, which makes it difficult to treat with chemicals. Based on various physiochemical characteristics of oils, surfactants, and organic solvents, an oil-in-water (O/W) nano-emulsion formulation was developed and optimized to combat citrus HLB. The nano-emulsion was formulated through a spontaneous emulsification method for efficient delivery of ampicillin into the citrus phloem using bark application. The nano-emulsion that was prepared from Cremophor EL (viscous oil), acetone (water miscibility organic solvent), and Span 80/Tween 80 (surfactant) formed a small droplet size (17.33 ± 0.52 nm) and exhibited an improved absorption rate. Peak concentration was detected at 2 days posttreatment and the maximum concentration (Cmax) and relative bioavailability (RBA) of ampicillin in HLB-affected citrus were 71.86 ± 35.38 ng/g and 267.25% ± 44.1%, respectively. The peak concentration of Amp appeared at 6 days posttreatment in the citrus trees that were treated with Amp alone and their Cmax and RBA were 56.44 ± 32.59 ng/g and 100%, respectively. The same nano-emulsion was used to deliver five different antimicrobials to control citrus HLB through bark application. We found that the droplet size of the antimicrobials in the nano-emulsion was significantly reduced and the nano-emulsion also enhanced the therapeutic efficiency of validoxylamine A alone and in combination with actidione as well as sulfadimoethoxine sodium against Las. Therefore, this study provides an efficient bark application nano-emulsion formulation for citrus HLB control.

Translocation of active mitochondria during buffalo (Bubalus bubalis) oocytes in vitro maturation, fertilization and preimplantation embryo development.

Mitochondria are energy-supplying organelles, whose distribution and functional integrity are necessary for cell survival and development. In this study, the mitochondrial distribution pattern and activity during buffalo oocyte in vitro maturation, fertilization and preimplantation embryo development were revealed using a fluorescent dye and confocal laser scanning microscopy. Distribution of active mitochondria changed during buffalo oocyte in vitro maturation. Active mitochondria were transferred from the outer to inner and perinuclear cytoplasm as oocytes matured in vitro and aggregated around the pronuclei in the fertilized eggs. Active mitochondria were also observed in preimplantation embryos. In the two-cell stage, they were distributed throughout the cytoplasm. From four-cell to the spherical embryonic stages, active mitochondria translocated to the perinuclear and the periphery of the cytoplasm. These results confirm that mitochondria play an important role in oocyte and embryo. The distribution of active mitochondria might be a marked feature of buffalo oocyte maturation, fertilization and preimplantation embryo development in vitro.

First Report of Damping-Off on Basella rubra Caused by Rhizoctonia solani Anastomosis Group 4 in Florida.

Indian spinach (Basella rubra L.) is a red stem species of Basella that is cultivated worldwide as an ornamental and the aerial parts are also consumed as a vegetable. In May of 2011, symptoms of damping-off were observed on approximately 10% of the plants at the stem base around the soil line of seedlings in a greenhouse in Homestead, FL. Lesions were initially water soaked, grayish to dark brown, irregular in shape, and sunken in appearance on large plants, causing the infected seedlings to collapse and eventually die. Symptomatic stem tissue was surface sterilized with 0.6% sodium hypochlorite, rinsed in sterile distilled water, air dried, and plated on potato dextrose agar (PDA). Plates were incubated at 25°C in darkness for 3 to 5 days. A fungus was isolated in all six isolations from symptomatic tissues on PDA. Fungal colonies on PDA were light gray to brown with abundant growth of mycelia, and the hyphae tended to branch at right angles when examined under a microscope. A septum was always present in the branch of hyphae near the originating point and a slight constriction at the branch was observed. Neither conidia nor conidiophores were found from the cultures on PDA. The characteristics of hyphae, especially the right angle branching of mycelia, indicate close similarity to those of Rhizoctonia solani (2,3). The internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced (GenBank Accession No. JN545836). Subsequent database searches by the BLASTN program indicated that the resulting sequence had a 100% identity over 472 bp with the corresponding gene sequence of R. solani anastomosis group (AG) 4 (GenBank Accession No. JF701752.1), a fungal pathogen reported to cause damping-off on many crops. Pathogenicity was confirmed through inoculation of healthy India spinach plants with the hyphae of isolates. Four 4-week-old plants were inoculated with the isolates by placing a 5-mm PDA plug of mycelia at the stem base and covering with a thin layer of the soil. Another four plants treated with sterile PDA served as a control. After inoculation, the plants were covered with plastic bags for 24 h and maintained in a greenhouse with ambient conditions. Four days after inoculation, water-soaked, brown lesions, identical to the symptoms described above, were observed on the stem base of all inoculated plants, whereas no symptoms developed on the control plants. The fungus was isolated from affected stem samples, and the identity was confirmed by microscopic appearance of the hyphae and sequencing the ITS1/ITS4 intergenic spacer region, fulfilling Koch's postulates. This pathogenicity test was conducted twice. R. solani has been reported to cause damping-off of B. rubra in Ghana (1) and Malaysia (4). To our knowledge, this is the first report of damping-off caused by R. solani AG-4 on Indian spinach in Florida and the United States. With the increased interest in producing Asian vegetables for food and ornamental purposes, the occurrence of damping-off on Indian spinach needs to be taken into account when designing programs for disease management in Florida. References: (1) H. A. Dade. XXIX. Bull. Misc. Inform. 6:205, 1940. (2) J. R. Parmeter et al. Phytopathology 57:218, 1967. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St Paul, MN, 1991. (4) T. H. Williams and P. S. W. Liu. Phytopathol. Pap. 19:1, 1976.

Genetic diversity and host range variation of Ralstonia solanacearum strains entering North America.

Each year, large volumes of ornamental and food plant propagative stock are imported into the North America; occasionally, Ralstonia solanacearum is found systemically infecting this plant material. In this study, 107 new R. solanacearum strains were collected over a 10-year period from imported propagative stock and compared with 32 previously characterized R. solanacearum strains using repetitive polymerase chain reaction (rep-PCR) element (BOX, ERIC, and REP) primers. Additional strain comparisons were made by sequencing the endoglucanase and the cytochrome b561 genes. Using rep-PCR primers, populations could be distinguished by biovar and, to a limited extent, country of origin and original host. Similarity coefficients among rep-PCR clusters within biovars were relatively low in many cases, indicating that disease outbreaks over time may have been caused by different clonal populations. Similar population differentiations of R. solanacearum were obtained when comparing strain sequences using either the endoglucanase or cytochrome b561 genes. We found that most of the new biovar 1 strains of R. solanacearum entering the United States were genetically distinct from the biovar 1 strains currently found infecting vegetable production. These introduced biovar 1 strains also had a broader host range and could infect not only tomato, tobacco, and potato but also anthurium and pothos and cause symptoms on banana. All introductions into North America of race 3, biovar 2 strains in the last few years have been linked to geranium production and appeared to be clonal.

Effect of sildenafil on acrolein-induced airway inflammation and mucus production in rats.

Airway inflammation with mucus overproduction is a distinguishing pathophysiological feature of many chronic respiratory diseases. Phosphodiesterase (PDE) inhibitors have shown anti-inflammatory properties. In the present study, the effect of sildenafil, a potent inhibitor of PDE5 that selectively degrades cyclic guanosine 3',5'-monophosphate (cGMP), on acrolein-induced inflammation and mucus production in rat airways was examined. Rats were exposed to acrolein for 14 and 28 days. Sildenafil or distilled saline was administered intragastrically prior to acrolein exposure. Bronchoalveolar lavage fluid (BALF) was acquired for cell count and the detection of pro-inflammatory cytokine levels. Lung tissue was examined for cGMP content, nitric oxide (NO)-metabolite levels, histopathological lesion scores, goblet cell metaplasia and mucin production. The results suggested that sildenafil pretreatment reversed the significant decline of cGMP content in rat lungs induced by acrolein exposure, and suppressed the increase of lung NO metabolites, the BALF leukocyte influx and pro-inflammatory cytokine release. Moreover, sildenafil pretreatment reduced acrolein-induced Muc5ac mucin synthesis at both mRNA and protein levels, and attenuated airway inflammation, as well as epithelial hyperplasia and metaplasia. In conclusion, sildenafil could attenuate airway inflammation and mucus production in the rat model, possibly through the nitric oxide/cyclic guanosine 3',5'-monophosphate pathway, and, thus, might have a therapeutic potential for chronic airway diseases.

Bacterial Brown Leaf Spot of Citrus, a New Disease Caused by Burkholderia andropogonis.

A new bacterial disease of citrus was recently identified in Florida and is here named bacterial brown leaf spot (BBLS) of citrus. BBLS-infected citrus leaves from the field displayed circular, brownish, flat lesions with slightly raised and water-soaked margins surrounded by a chlorotic halo. Based on Biolog carbon source metabolic "fingerprinting", fatty acid analysis, and sequence analysis of partial 16S rDNA, gyrB, and rpoD genes, the causal agent of the disease was identified as Burkholderia andropogonis. Pathogenicity of these B. andropogonis isolates taken from multiple citrus leaves with BBLS was tested by various inoculation methods on three species of citrus as well as on carnation, corn, and sorghum. All isolates infected carnation, corn, and sorghum with varying degrees of pathogenicity. Variation among citrus isolates in pathogenicity was also observed in high titer (108 CFU/ml) inoculations of citrus leaves, ranging from a hypersensitive-like response to canker-like lesions. When the inoculum concentration was low (106 CFU/ml), only necrotic spots or small lesions slowly developed with all strains. Growth of B. andropogonis in citrus was relatively slow, tissue wounding appeared necessary for symptom appearance with many isolates, and field samples were recovered only after severe storms, indicating that this wide-host-range bacterium is a weak, opportunistic pathogen of citrus.

First Report of Dodder Transmission of 'Candidatus Liberibacter asiaticus' to Tomato (Lycopersicon esculentum).

Citrus huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. The disease is associated with three different species of fastidious α-proteobacteria, namely 'Candidatus Liberibacter asiaticus', Ca. L. americanus, and Ca. L. africanus (1). 'Ca. L. asiaticus' was first detected in South Florida in 2005 and has spread throughout the citrus-growing areas of Florida. 'Ca. L. asiaticus' is transmitted naturally by the Asian citrus psyllid, Diaphorina citri, and can also be transmitted by graft propagation and via various species of dodder (Cuscuta). HLB affects most if not all citrus and citrus relatives within the family Rutaceae (2), including the ornamental shrub Murraya paniculata (4). In addition, 'Ca. L. asiaticus' and 'Ca. L. americanus' can infect tobacco (Nicotiana xanthi) and periwinkle (Catharanthus roseus) (1,4). Here we report that 'Ca. L. asiaticus' can infect tomato (Lycopersicon esculentum) cvs. Manapal and FL47. Manapal and FL 47 plants grown from seed were placed adjacent to 'Ca. L. asiaticus'-infected sweet orange (Citrus sinensis) plants with dodder (Cuscuta pentagona) already well established on them. Young dodder shoots still connected to the citrus were draped over the tomato plants and subsequently also became attached to the tomato stems. After 1 month, the tomato plants were detached from the citrus and most of the dodder removed. One month later, these tomato plants started to show vein clearing and subsequently the mature leaves became thicker and leathery. Some leaves showed blotchy mottle symptoms and some fruits became lopsided in a manner similar to HLB symptom expression on citrus. PCR amplification of the 'Ca. L. asiaticus' 16S rDNA with primers OI1/OI2c and the ß-operon with primers A2/J5 (1) revealed the presence of 'Ca. L. asiaticus' DNA. Sequence analysis confirmed that the sequences of the cloned amplicons were identical to those from the HLB-infected citrus source plant. Both conventional and quantitative real-time PCR (3) revealed a much lower abundance of 'Ca. L. asiaticus' DNA in tomato as compared with 'Ca. L. asiaticus'-infected citrus or periwinkle, indicating that 'Ca. L. asiaticus' bacteria multiplied at a lower titer in these tomato cultivars. References: (1) J. M. Bové, J. Plant Pathol. 88:7, 2006. (2) S. E. Halbert et al. Fla. Entomol. 87:330, 2004. (3) W. Li et al. J. Microbiol. Methods 66:104, 2006. (4) L. Z. Zhou et al. Plant Dis. 91:227, 2007.

First Report of Dodder Transmission of Huanglongbing from Naturally Infected Murraya paniculata to Citrus.

Huanglongbing (HLB) or "greening" disease of citrus is caused by phloem-limited, uncultured bacteria in the genus "Candidatus Liberibacter". HLB is one of the most destructive diseases of citrus worldwide and is considered so dangerous to a U.S. citrus production that the USDA has listed "Ca. Liberibacter species" as a Select Agent. HLB is spread by the Asian citrus psyllid, Diaphorina citri, which was intercepted 40 times by APHIS/PPQ at U.S. ports between 1985 and 1998, became established in Florida by 1998, and more recently in Texas (1). HLB was first detected in the United States near Miami, FL during August 2005, and to date has been confirmed to have spread to 12 Florida counties. In addition to citrus, Murraya paniculata (orange jasmine) is a preferred host of D. citri, and retail trade in this ornamental shrub is strongly implicated in the distribution of D. citri (1). M. paniculata is reported to be a cryptic or largely asymptomatic host of "Ca. Liberibacter" (4), but another report concludes that the bacteria cannot replicate in M. paniculata (2). The epidemiological significance of murraya as a host for the HLB pathogen is therefore unclear. We report here the transmission of "Ca. Liberibacter asiaticus" from M. paniculata to citrus. Two M. paniculata plants, suspected of harboring "Ca. Liberibacter" because of their proximity to HLB-infected citrus and infested with D. citri, were removed from the field, treated with insecticide, and transferred to a quarantine facility. Both plants tested positive for "Ca. Liberibacter" by nested PCR using primers OI1 and OI2 (3) as the first set and primers CGO3F (RGG GAA AGA TTT TAT TGG AG) and CGO5R (GAA AAT AYC ATC TCT GAT ATC GT) as the second set. Two, young, sweet orange plants (Citrus sinensis) grown and maintained in psyllid-free greenhouses in Gainesville, FL were infected by dodder (Cuscuta pentagona) grown from seed. After the dodder had become well established on the orange plants, the orange plants were moved adjacent to the two murraya plants and the dodder from the citrus was draped over the murraya. Coinfection of murraya by dodder occurred within a few days. Sixty days later, both murraya plants, both sweet orange plants, and the connecting dodder all repeatedly tested positive for "Ca. Liberibacter" by nested PCR. Beginning 2 weeks later, the orange plants tested positive by standard PCR using primer set OI1 and OI2 or CGO3F and CGO5R, but remained without typical greening symptoms. Sequencing of the PCR products confirmed amplification of "Ca. L. asiaticus" DNA. We conclude that M. paniculata can serve as an infection source of a Select Agent since it can host the HLB pathogen for at least 2 months and the HLB pathogen can be transmitted to sweet orange during this time. References: (1) S. E. Halbert and K. L. Manjunath. Florida Entomol. 87:330, 2004. (2) T. H. Hung et al. J. Phytopathol. 148:321, 2000. (3) S. Jagoueix et al. Mol. Cell Probes 10:43, 1996. (4) T. Li and C. Ke. Acta Phytophylacica Sin. 29:31, 2002.

Detection and characterization of Pasteuria 16S rRNA gene sequences from nematodes and soils.

Various bacterial species in the genus Pasteuria have great potential as biocontrol agents against plant-parasitic nematodes, although study of this important genus is hampered by the current inability to cultivate Pasteuria species outside their host. To aid in the study of this genus, an extensive 16S rRNA gene sequence phylogeny was constructed and this information was used to develop cultivation-independent methods for detection of Pasteuria in soils and nematodes. Thirty new clones of Pasteuria 16S rRNA genes were obtained directly from nematodes and soil samples. These were sequenced and used to construct an extensive phylogeny of this genus. These sequences were divided into two deeply branching clades within the low-G + C, Gram-positive division; some sequences appear to represent novel species within the genus Pasteuria. In addition, a surprising degree of 16S rRNA gene sequence diversity was observed within what had previously been designated a single strain of Pasteuria penetrans (P-20). PCR primers specific to Pasteuria 16S rRNA for detection of Pasteuria in soils were also designed and evaluated. Detection limits for soil DNA were 100-10,000 Pasteuria endospores (g soil)(-1).

[Non-anthraquinone constituents from Rheum sublanceolatum C. Y. Cheng et Kao].

OBJECTIVE: Study on the non-anthraquinone constituents from rhizoma and radix of Rheum sublanceolatum. METHOD: The constituents were isolated through column chromatography and identified on the basis of their physiochemical and spectral data. RESULT: Six non-anthraquinone constituents were isolated and identified as n-octacosanic acid, sitosterol, daucosterol, 2-methyl-5-carboxymethyl-7-hydroxychromone, piceatannol and 6-hydroxymusizin-8-O-beta-D-glucopyranoside. CONCLUSION: All these compounds were firstly isolated from R. sublanceolatum.

Characterization of the naphthalene-degrading bacterium, Rhodococcus opacus M213.

Bacterial strain M213 was isolated from a fuel oil-contaminated soil in Idaho, USA, by growth on naphthalene as a sole source of carbon, and was identified as Rhodococcus opacus M213 by 16S rDNA sequence analysis and growth on substrates characteristic of this species. M213 was screened for growth on a variety of aromatic hydrocarbons, and growth was observed only on simple 1 and 2 ring compounds. No growth or poor growth was observed with chlorinated aromatic compounds such as 2,4-dichlorophenol and chlorobenzoates. No growth was observed by M213 on salicylate, and M213 resting cells grown on naphthalene did not attack salicylate. In addition, no salicylate hydroxylase activity was detected in cell free lysates, suggesting a pathway for naphthalene catabolism that does not pass through salicylate. Enzyme assays indicated induction of catechol 1,2-dioxygenase and catechol 2,3-dioxygenase on different substrates. Total DNA from M213 was screened for hybridization with a variety of genes encoding catechol dioxygenases, but hybridization was observed only with catA (encoding catechol 1,2-dioxygenase) from R. opacus 1CP and edoD (encoding catechol 2,3-dioxygenase) from Rhodococcus sp. I1. Plasmid analysis indicated the presence of two plasmids (pNUO1 and pNUO2). edoD hybridized to pNUO1, a very large (approximately 750 kb) linear plasmid.

Phenotypic variation in transgenic tobacco expressing mutated geminivirus movement/pathogenicity (BC1) proteins.

Tobacco plants were transformed with the movement protein (pathogenicity) gene (BC1) from tomato mottle geminivirus (TMoV), using Agrobacterium-mediated transformation. Different transgenic tobacco lines that expressed high levels of the BC1 protein had phenotypes ranging from plants with severe stunting and leaf mottling (resembling geminivirus symptoms) to plants with no visible symptoms. The sequence data for the BC1 transgene from the transgenic plants with the different phenotypes indicated an association of spontaneously mutated forms of the BC1 gene in the transformed tobacco with phenotype variations. One mutated transgene associated with an asymptomatic phenotype had a major deletion at the C terminus of 119 amino acid residues with a recombination resulting in the addition of 26 amino acid residues of unidentified origin. This asymptomatic, mutated BC1 attenuated the phenotypic expression of the symptomatic BC1 in a tobacco line containing both copies of the BC1 gene. Another mutated form of the BC1 gene amplified from an asymptomatic, multicopy transgenic tobacco plant did not induce symptoms when transiently expressed in tobacco via a virus vector. The symptom attenuation in the transgenic tobacco by the asymptomatic BC1 may involve trans-dominant negative interference.

Cataractogenesis and lipid peroxidation in newborn rats treated with buthionine sulfoximine: preventive actions of melatonin.

The purpose of this study was to examine the influence of exogenously administered melatonin on cataract formation and lipid peroxidation in newborn rats treated with buthionine sulfoximine (BSO), a drug which inhibits the rate-limiting enzyme in glutathione (GSH) synthesis, gamma-glutamylcysteine synthase, thereby depleting animals of their stores of the important intracellular antioxidant, GSH. BSO (3 mmol/kg BW) was given for three consecutive days beginning on postnatal day 2; melatonin (4 mg/kg) was injected daily beginning on postnatal day 2 and continuing until the animals were killed (either day 9 or day 17 after birth). None of the control animals (rats treated with neither BSO nor with melatonin) developed lenticular opacification during the observation period. In the BSO-treated rats, 16 of 18 animals (89%) had observable cataracts when they were examined. In rats that received both BSO and melatonin, the incidence of cataracts was highly significantly decreased, i.e., only 3 of 18 rats (7%) had observable cataracts. In addition to cataracts, the level of lipid peroxidation products (malondialdehyde (MDA) and 4-hydroxyalkenals (4-HDA)) was examined in the lens, brain, liver, lung, and kidney of control and experimental animals. In BSO-treated rats, the lens, kidney, and lung exhibited increased levels of MDA plus 4-HDA relative to those measured in the control rats; these increases were reversed in the BSO-treated rats who were injected with melatonin daily. While BSO administration did not increase basal levels of MDA plus 4-HDA in either the brain or liver, melatonin reduced levels of lipid peroxidation products below those measured in the control rats (at 17 days after birth). The changes induced by melatonin are consistent with the free-radical scavenging and antioxidative properties of this indole.

Cloning and Characterization of a Member of the Xanthomonas avr/pth Gene Family That Evades All Commercially Utilized Cotton R Genes in the United States.

ABSTRACT The highly virulent African strains of Xanthomonas campestris pv. malvacearum are quarantined pathogens in the United States and can evade or overcome all commercially utilized resistance (R) genes in cotton grown in the United States including the entire set of host differential lines used to distinguish 19 races of the pathogen. Nevertheless, the African strains carry multiple DNA fragments that strongly hybridize with members of the Xanthomonas avirulence (avr)/pathogenicity (pth) gene family. Since all previously tested members of the gene family confer avirulence against one or more R genes in cotton, strains carrying multiple members might not be expected to evade so many different R genes. The hybridizing DNA fragments were cloned from African strain XcmN and found to confer water-soaking ability to a nearly asymptomatic mutant strain of the pathogen. Restriction mapping, Southern hybridization, and DNA sequencing of the cloned fragments from XcmN were used to identify two water-soaking genes, pthN and pthN2, as new members of the Xanthomonas avr/pth gene family. The complete DNA sequence of pthN was obtained, and it is >94% identical with all other sequenced members of the gene family. Gene fusions of pthN with avrb6 (another family member) and other experiments revealed that the ability of African strain XcmN to water-soak cotton and avoid recognition by commercially used cotton R genes is determined by the specific repeats of multiple functional members of the Xanthomonas avr/pth gene family.

Laboratory and clinical diagnosis of human cytomegalovirus infection after transplantation.

Urine and blood specimens from 32 recipients of allograft organ transplant were investigated for human cytomegalovirus (HCMV) by conventional cell culture, indirect immunofluorescent assay subsequent to the rapid cell culture and DNA-DNA hybridization. The results showed that the rapid cell culture technique might be the best method for rapid detection of active HCMV infection after transplantation because it possesses the advantages of simplicity, speediness, sensitiveness, and high reliability of detecting productive HCMV infection. The major symptoms were prolonged or intermittent fever unresponsive to antibiotics, dysfunction or loss of function of the transplanted organ, pulmonary infiltrates and leukopenia. As our results suggested, reactivation of a latent infection appears to be the most probable etiologic factor contributing to HCMV infection after transplantation.

DNA probe technique for diagnosis of human cytomegalovirus infection.

A rapid diagnostic assay for human cytomegalovirus (HCMV) has been developed for detecting HCMV DNA in urine samples with 32P-labelled cloned fragment, Eco RI fragment B, of DNA from HCMV strain Towne. 3.2 pg of homologous fragment from HCMV DNA could be detected by the labelled probe, and it did not hybridize DNA from other herpes viruses or human cells in dot hybridization assay. The assay correctly identified all (100%) of 7 coded urine specimen cultures positive for HCMV and 9 (90%) of 10 urine sample cultures negative for HCMV. So the hybridization assay was correct and as sensitive as the currently available tissue culture technique. The infection levels of different populations, such as organ transplantation recipients, patients with infantile hepatitis syndrome, normal infants, fetuses, have been investigated by the hybridization assay in the present study.