Back to the future of oridonin： again, compound from medicinal herb shows potent antileukemia efficacies in vitro and in vivo

Traditional Chinese Medicine （TCM） has been widely and successfully used in treating illnesses ranging from inflammation to cancer, and compounds from medicinal herbs and minerals are playing more and more important roles in taming various kinds of diseases [1 ], exemplified by artemisinin and arsenic trioxide （ATO）. Artemisinin （or Qinghaosu in Chinese） is isolated from a plant called sweet wormwood （Artemisia annua; or Qinghao in Chi- nese） which has been used as an antipyretic remedy for more than 1500 years in China. Artemisinin has impressive parasiticidal properties in vitro and in vivo, and is now one of the most important class of antimalarial agents [2, 3]. ATO is a common, naturally occurring substance which had been used in China for a long time as a therapeutic agent for some severe diseases with the ancient philosophy of ＇treating an evil with a toxic＇ [4]. In 1990s, ATO was shown to be able to cause partial differentiation at low dose and apoptosis at high concentration of acute promyelocytic leukemia （APL） cells [5], and induce complete remission in 90% of patients with relapsed or refractory APL [6-8]. These paradigms suggest that TCM is the treasure house not only for the Chinese people, but also for the whole human beings. It is our responsibility to develop evidence-based therapeutic approaches from TCM for diseases with poor prognosis.     

Use of polymerase chain reaction to detect the soft rot pathogen,Pythium myriotylum,in infected ginger rhizomes

AIMS: The aims are to establish a polymerase chain reaction (PCR)-based method for detecting Pythium myriotylum in the rhizome of ginger and diagnosing ginger soft rot and screening health seed ginger. METHODS AND RESULTS: A booster PCR method was established for detection of P. myriotylum using a specific primer selected from rDNA ITS1 region coupled with universal primer ITS2. It successfully applied to the detection of P. myriotylum in naturally infected ginger rhizomes but not from DNA of ginger rhizomes collected from field without target fungus. CONCLUSIONS: A specific method for detecting P. myriotylum was achieved. SIGNIFICANCE AND IMPACT OF THE STUDY: The new PCR method has allowed us to monitor ginger for the presence of P. myriotylum as a way of disease diagnosis or healthy seed ginger examination.     

Biological control of pathogen communication in the rhizosphere: A novel approach applied to potato soft rot due to Pectobacterium atrosepticum

Background and aims

Recent basic knowledge on the regulation of virulence in pectinolytic bacteria revealed pathogen communication via quorum sensing signals as a crucial event for the expression of virulence and the onset of disease symptoms. In this paper, we present and discuss advances in a new biocontrol approach based on the interference of microbial communication involved in the cellular density and microenvironment sensoring.

Methods

This emerging strategy consists in the characterization of the signaling molecules used by the target pathogen, then the use of harmless structural analogs to stimulate plant associated-microflora able to degrade both molecule families.

Results

The biocontrol method has been applied for the first time for the control of Pectobacterium atrosepticum. This psychrotrophic bacterium synthesizes N-acyl-homoserine lactones involved in cell-to-cell communication that triggers soft rot and blackleg of potato. The use of the gamma-caprolactone stimulant promotes the emergence and catabolic activity of Rhodococcus erythropolis antagonistic populations in the potato rhizosphere.

Conclusions

Rhodococcus bacteria have the ability to disrupt the quorum sensing-based communication of P. atrosepticum by degrading N-acyl-homoserine lactone signaling molecules and prevent disease.     

Controversies in Neurology: why monoamine oxidase B inhibitors could be a good choice for the initial treatment of Parkinson's disease

Background  

Early initiation of pharmacotherapy in Parkinson's disease (PD) is nowadays widely advocated by experts since the delay of treatment has shown to be associated with a significant deterioration of health related quality of life in affected patients. Due to marked advances in PD treatment during the last decades, physicians are nowadays fortunately equipped with a variety of substances that can effectively ameliorate emerging motor symptoms of the disease, among them levodopa, dopamine agonists and monoamine oxidase type B (MAO-B) inhibitors. Despite numerous drug intervention trials in early PD, there is however still ongoing controversy among neurologists which substance to use for the initial treatment of the disease.     

Assessment of genetic diversity through RAPD,ISSR and AFLP markers in Podophyllum hexandrum: a medicinal herb from the Northwestern Himalayan region

Total synthesis of podophyllotoxin is an expensive process and availability of the compound from the natural resources is an important issue for pharmaceutical companies that manufacture anticancer drugs. In order to facilitate reasoned scientific decisions on its management and conservation for selective breeding programme, genetic analysis of 28 populations was done with 19 random primers, 11 ISSR primers and 13 AFLP primer pairs. A total of 92.37 %, 83.82 % and 84.40 % genetic polymorphism among the populations of Podophyllum were detected using RAPD, ISSR and AFLP makers, respectively. Similarly the mean coefficient of gene differentiation (Gst) were 0.69, 0.63 and 0.51, indicating that 33.77 %, 29.44 % and 26 % of the genetic diversity resided within the population. Analysis of molecular variance (AMOVA) indicated that 53 %, 62 % and 64 % of the genetic diversity among the studied populations was attributed to geographical location while 47 %, 38 % and 36 % was attributed to differences in their habitats using RAPD, ISSR and AFLP markers. An overall value of mean estimated number of gene flow (Nm) were 0.110, 0.147 and 0.24 from RAPD, ISSR and AFLP markers indicating that there was limited gene flow among the sampled populations.     

Vestibular histofluorescence could be due to accumulation of both the antibiotic and its derivative, streptidine, after acute streptomycin treatment in the guinea pig

Acute treatment with 300 mg/kg of pigmented guinea pigs with streptomycin sulfate induces an elevation of endogenous fluorescence in vestibular ampullary cristae. Fluorescence accumulates in all compartments of the epithelium, i.e., vestibular sensory and supporting cells and nerve fibers of the stroma and it was very intense 1 and 12 hours after its administration. Fluorescence decreased to control levels 24 hours following streptomycin injection. Fluorescence levels were very low either in untreated animals or in animals injected with saline physiological solution. To investigate whether this fluorescence was an intrinsic property of the antibiotic or whether it was due to a derivative of it, or both, an in vitro fluorescence spectrum was performed with 100 microM solutions of streptomycin or streptidine, or both, dissolved in various buffer solutions at 488 nm of excitation. A discrete level of fluorescence was observed in the spectrum regardless of media when separate solutions of both streptomycin or streptidine were studied. Fluorescence notably increased at 522-532 nm when the solutions contained both streptomycin and streptidine together. These results suggest that streptidine putatively derived from streptomycin may contribute to the observed fluorescence accumulation in vestibular preparations after acute treatment. Thus, these metabolic properties of the inner ear which transform streptomycin into streptidine, something never considered earlier, could be claimed as partially responsible for converting a therapeutic agent into a compound which could be as harmful as STP to the inner ear.     

Phosphatases in apoptosis: to be or not to be,PP2A is in the heart of the question

Protein phosphatase type 2A (PP2A) is a major Ser/Thr phosphatase involved in several cellular signal transduction pathways. In this review, we will focus on recent progress concerning the role of PP2A in apoptotic signalling. Since PP2A activates pro-apoptotic and inhibits anti-apoptotic proteins of the Bcl-2 family, we conclude that PP2A has a positive regulatory function in apoptosis. However, in Drosophila, a specific subset of the PP2A holoenzyme family, containing B'/PR61 as third regulatory subunit, is inhibitory for apoptosis, suggesting different regulatory mechanisms and substrates in different species. Moreover, PP2A acts not only upstream as a regulator of the apoptotic signal transduction pathway but also downstream as a substrate of effector caspases. Hence, PP2A is involved in the regulation as well as in the cellular response of apoptosis. Probably, various PP2A holoenzymes with distinct regulatory subunits specifically target different apoptotic substrates. This could explain the implication of PP2A at several levels of the apoptotic signal transduction pathway. Finally, some viral proteins such as adenovirus E4orf4 and simian virus small t target PP2A to alter its activity, resulting in induction of apoptosis as a regulatory mechanism to enhance virus spread.     

Plant defense gene promoter enhances the reliability of<Emphasis Type="Italic"> shiva-1</Emphasis> gene-induced resistance to soft rot disease in potato

PAL5, a tomato (Lycopersicon esculentum Mill.) plant defense gene that encodes phenylalanine ammonia-lyase, is known to respond to a variety of environmental stresses including pathogen infection and wounding. A shiva-1 gene recombinant that encodes a small synthetic antibacterial peptide under the PAL5 gene promoter was transformed into potato (Solanum tuberosum L.) and its ability to induce resistance to Erwinia carotovora was compared with a construct under the control of the constitutive and widely used cauliflower mosaic virus (CaMV) 35S promoter. The shiva-1 peptide, an analog of natural cecropin B, was shown previously to have high bactericidal activity in vitro, but when expressed in vivo under the control of the CaMV 35S promoter, the effects were very inconsistent. As observed previously, in the present studies a few transformants with the CaMV 35S promoter were highly resistant when assayed for susceptibility to soft rot disease. In marked contrast the majority of transformants with the PAL5 gene promoter were highly resistant. More-detailed analyses of the incorporated DNA indicated that most of the transformants with the CaMV 35S promoter contained multiple copies of the transforming DNA while all of the PAL5 recombinants contained single copies. The highly resistant CaMV 35S recombinant also was present as a single copy. The results indicate that, at least in this instance, a constitutive promoter may not be ideal for the effective expression of a foreign gene and suggest that multiple insertions may have negative consequences.     

Detection,identification and morphological characteristic of Macrophomina phaseolina: the charcoal rot disease pathogens isolated from infected plants in Northern Jordan

This is the first report about charcoal rot disease in Jordan. Twenty-five Macrophomina phaseolina isolates were collected from infected plants showing typical symptoms of charcoal rot disease. All of the 25 M. phaseolina isolates were pathogenic to cucumber plants under green house effect. The amplification of the isolated DNA from the 25 pathogenic fungal cultures using ITS specific primers (ITS 1?+?ITS 4) showed a single band of 580?bp. There was a significant variation of their mycelial linear growth rate on PDA medium. The 25 M. phaseolina isolates showed a wide heterogeneity in their mycelium colour, microsclerotia distribution, pycnidia formation and chlorate phenotypes. Based on the morphological characterisation, the 25 isolates were grouped into seven different groups as indicated in a dendrogram of their morphological variation. The overall means similarity matrix of the 25 M. phaseolina recovered isolates were 0.58. The means of similarity matrix of the 25 M. phaseolina was in between 0.83 and 0.14. The similarity coefficient between the 25 isolates varies between 0.27 and 1.0.     

To be or not to be, the level of autophagy is the question: dual roles of autophagy in the survival response to starvation

Autophagy is an evolutionally conserved lysosomal pathway used to degrade and turn over long-lived proteins and cytoplasmic organelles. Since autophagy was discovered, it has been thought to act as a pro-survival response to several stresses, especially starvation, at the cell and organism levels by providing recycled metabolic substrates to maintain energy homeostasis. However, several recent studies suggest that autophagy also plays a pro-death role through an autophagic cell death pathway mostly at the cellular level. The mechanism by which autophagy could perform these seemingly opposite roles as a pro-survival and a pro-death mechanism remained elusive until recently. Using C. elegans as a model system, we found that physiological levels of autophagy promote optimal survival of C. elegans during starvation, but either insufficient or excessive levels of autophagy render C. elegans starvation-hypersensitive. Furthermore, we found that muscarinic acetylcholine receptor signaling is important in modulating the level of autophagy during starvation, perhaps through DAP kinase and RGS-2. Our recent study provides in vivo evidence that levels of autophagy are critical in deciding its promotion of either survival or death: Physiological levels of autophagy are pro-survival, whereas insufficient or excessive levels of autophagy are pro-death.     

Seasonal variations in the activity in soil of Phytophthora cactorum, P. syringae and P. citricola in relation to collar rot disease of apple

Phytophthora species were isolated from infested orchard soils using apple fruit as bait at intervals during the periods July 1956 to August 1957, January 1957 to June 1958, and January 1969 to June 1970. When baited soils were kept out of doors P. cactorum and P. citricola were isolated only from April or May to October, when mean temperatures exceeded 8 and 10 °C respectively; P. syringae was isolated in all months except June, July and August.
The results did not suggest that the incidence of these species was particularly associated with apple as a host plant, but the periods of activity of P. cactorum and P. syringae in soils coincided closely with the periods when apple trees were susceptible to infection by either pathogen. With collar rot disease caused by P. cactorum it was considered that, the time of commencement of activity of the pathogen in the soil, together with the availability of water, might be critical in determining the severity of disease outbreaks.     

Filterable marine bacteria found in the deep sea: Distribution,taxonomy, and response to starvation

A significant number of viable colony-forming bacteria were recovered from deep-ocean bottom water samples passed through a 0.45m filter. However, these bacteria small enough to pass through a 0.45m membrane filter and termed filterable bacteria were less abundant in open-ocean surface water and coastal water samples. The reduced size of bacterial cells present in deep-ocean bottom water samples was documented by scanning electron microscopy. The concentration of ATP in the water samples was found to be correlated with results of direct counts of bacteria.Numerical taxonomy of bacterial strains isolated from water samples collected at two stations in the deep sea yielded taxonomic clusters grouped according to sample and size fraction. The generic composition of bacterial populations of bottom water filtrates was compared with that of bacteria retained by 0.45 m filters. Strains ofAlcaligenes, Flavobacterium, Pseudomonas, andVibrio spp. were identified among those retained by, as well as passing through, 0.45m filters.Two marine isolates obtained from the filtrate of a deep-ocean water sample were incubated for 9 weeks in nutrient-free artificial seawater, during which the cells became rounded and reduced in size. After the 9-week incubation period, more than 10% of the viable cells of both cultures were able to pass through a 0.4m filter. The viable count at 9 weeks wasca. 10% of that of the initial population, although from direct counts the total population number remained relatively constant throughout the incubation period. From the observed reduction in cell size and increased starvation resistance of cells held under low nutrient conditions, it is concluded that a significant relationship exists between decreased cell size and increased survival of marine bacteria in the deep sea.This investigation was supported by Grant No. OCE 76-82655 from the National Science Foundation.     

Cutting edge: crucial role of IL-1 and IL-23 in the innate IL-17 response of peripheral lymph node NK1.1- invariant NKT cells to bacteria

We have shown previously that peripheral lymph node-resident retinoic acid receptor-related orphan receptor γt(+) NK1.1(-) invariant NKT (iNKT) cells produce IL-17A independently of IL-6. In this study, we show that the concomitant presence of IL-1 and IL-23 is crucial to induce a rapid and sustained IL-17A/F and IL-22 response by these cells that requires TCR-CD1d interaction and partly relies on IL-23-mediated upregulation of IL-23R and IL-1R1 expression. We further show that IL-1 and IL-23 produced by pathogen-associated molecular pattern-stimulated dendritic cells induce this response from NK1.1(-) iNKT cells in vitro, involving mainly TLR2/4-signaling pathways. Finally, we found that IL-17A production by these cells occurs very early and transiently in vivo in response to heat-killed bacteria. Overall, our study indicates that peripheral lymph node NK1.1(-) iNKT cells could be a source of innate Th17-related cytokines during bacterial infections and supports the hypothesis that they are able to provide an efficient first line of defense against bacterial invasion.