Phytophthora capsici: Recent Progress on Fundamental Biology and Disease Management 100 Years After Its Description

Phytophthora capsici is a destructive oomycete pathogen of vegetable, ornamental, and tropical crops. First described by L.H. Leonian in 1922 as a pathogen of pepper in New Mexico, USA, P. capsici is now widespread in temperate and tropical countries alike. Phytophthora capsici is notorious for its capability to evade disease management strategies. High genetic diversity allows P. capsici populations to overcome fungicides and host resistance, the formation of oospores results in long-term persistence in soils, zoospore differentiation in the presence of water increases epidemic potential, and a broad host range maximizes economic losses and limits the effectiveness of crop rotation. The severity of disease caused by P. capsici and management challenges have led to numerous research efforts in the past 100 years. Here, we discuss recent findings regarding the biology, genetic diversity, disease management, fungicide resistance, host resistance, genomics, and effector biology of P. capsici.

Polymeric Pathogen-Like Particles-Based Combination Adjuvants Elicit Potent Mucosal T Cell Immunity to Influenza A Virus

Eliciting durable and protective T cell-mediated immunity in the respiratory mucosa remains a significant challenge. Polylactic-co-glycolic acid (PLGA)-based cationic pathogen-like particles (PLPs) loaded with TLR agonists mimic biophysical properties of microbes and hence, simulate pathogen-pattern recognition receptor interactions to safely and effectively stimulate innate immune responses. We generated micro particle PLPs loaded with TLR4 (glucopyranosyl lipid adjuvant, GLA) or TLR9 (CpG) agonists, and formulated them with and without a mucosal delivery enhancing carbomer-based nanoemulsion adjuvant (ADJ). These adjuvants delivered intranasally to mice elicited high numbers of influenza nucleoprotein (NP)-specific CD8+ and CD4+ effector and tissue-resident memory T cells (T_RMs) in lungs and airways. PLPs delivering TLR4 versus TLR9 agonists drove phenotypically and functionally distinct populations of effector and memory T cells. While PLPs loaded with CpG or GLA provided immunity, combining the adjuvanticity of PLP-GLA and ADJ markedly enhanced the development of airway and lung T_RMs and CD4 and CD8 T cell-dependent immunity to influenza virus. Further, balanced CD8 (Tc1/Tc17) and CD4 (Th1/Th17) recall responses were linked to effective influenza virus control. These studies provide mechanistic insights into vaccine-induced pulmonary T cell immunity and pave the way for the development of a universal influenza and SARS-CoV-2 vaccines.

Carbomer-based adjuvant elicits CD8 T-cell immunity by inducing a distinct metabolic state in cross-presenting dendritic cells

There is a critical need for adjuvants that can safely elicit potent and durable T cell-based immunity to intracellular pathogens. Here, we report that parenteral vaccination with a carbomer-based adjuvant, Adjuplex (ADJ), stimulated robust CD8 T-cell responses to subunit antigens and afforded effective immunity against respiratory challenge with a virus and a systemic intracellular bacterial infection. Studies to understand the metabolic and molecular basis for ADJ's effect on antigen cross-presentation by dendritic cells (DCs) revealed several unique and distinctive mechanisms. ADJ-stimulated DCs produced IL-1β and IL-18, suggestive of inflammasome activation, but in vivo activation of CD8 T cells was unaffected in caspase 1-deficient mice. Cross-presentation induced by TLR agonists requires a critical switch to anabolic metabolism, but ADJ enhanced cross presentation without this metabolic switch in DCs. Instead, ADJ induced in DCs, an unique metabolic state, typified by dampened oxidative phosphorylation and basal levels of glycolysis. In the absence of increased glycolytic flux, ADJ modulated multiple steps in the cytosolic pathway of cross-presentation by enabling accumulation of degraded antigen, reducing endosomal acidity and promoting antigen localization to early endosomes. Further, by increasing ROS production and lipid peroxidation, ADJ promoted antigen escape from endosomes to the cytosol for degradation by proteasomes into peptides for MHC I loading by TAP-dependent pathways. Furthermore, we found that induction of lipid bodies (LBs) and alterations in LB composition mediated by ADJ were also critical for DC cross-presentation. Collectively, our model challenges the prevailing metabolic paradigm by suggesting that DCs can perform effective DC cross-presentation, independent of glycolysis to induce robust T cell-dependent protective immunity to intracellular pathogens. These findings have strong implications in the rational development of safe and effective immune adjuvants to potentiate robust T-cell based immunity.

Rapid detection of Bacillus ionophore cereulide in food products

Cereulide is a toxic cyclic depsipeptide produced by certain strains of Bacillus cereus found in soil and food products. While some harmless strains of Bacillus are used as probiotic, others can cause nausea and vomiting, and represent an important food safety concern. Current detection methods are time consuming and do not necessarily detect toxic cereulide. Here, we developed a rapid protocol using Matrix Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry that detects the toxin originating from a colony smear of B. cereus. The distinct molecular feature of the toxin peak at m/z 1,191 was clearly identified from bacterial extracts with a limit of detection (LOD) of 30 ng/mL. Final optimisation of the sample preparation was based on cereulide chelating cations to produce the alkali adduct [M + K]+ without the use of a MALDI matrix, and provided a 1,000-fold improvement of LOD with 30 pg/mL of cereulide. We evaluated the application of this method for the detection of cereulide in rice, milk, and different ready-to-eat meals. The proposed protocol is quick, easy and provides an improvement over conventional methods for the detection of B. cereus toxin.

Pharmacokinetics and Anticoagulant Effect of Hirudin in Man

The pharmacokinetics and the effects on the haemostatic system of hirudin were assessed in six healthy subjects after single intravenous or subcutaneous dose (1000 AT-U/kg). When hirudin was given intravenously first-order elimination kinetics followed the initial distribution phase. The decline in plasma hirudin concentration was most adequately expressed by a biexponential equation describing a two compartment model. A mean elimination half-life of 0.84 hr and a mean volume of distribution of 12.9 1 were calculated. After subcutaneous injection a low hirudin level (∼0.5 AT-U/ml) was maintained for a prolonged period of time.

In the 24 hour-urine up to 50 per cent of the administered amount of hirudin was excreted in active form.

Thrombin time, partial thromboplastin time and prothrombin time measured in plasma samples ex vivo were prolonged dependent on the hirudin plasma level. Platelet counts, fibrinogen level and the fibrinolytic system were unchanged. Bleeding time was prolonged twice at maximum.

Subcutaneous or intravenous administration of pure hirudin was tolerated without side-effects.

Health-related quality of life after general surgical intensive care

BACKGROUND

Impaired mental and physical health are common complications after intensive care that could influence the patient's health-related quality of life (HRQoL). Earlier research has mainly focused on HRQoL in mixed surgical and medical ICU populations. This study aimed to describe and analyze factors associated with HROoL after discharge from a general surgical ICU.

METHODS

A prospective cohort study was conducted in a general surgical ICU in Sweden between 2005 and 2012. Adult patients (≥18 years) with an ICU length of stay ≥96 hours were included. HRQoL was measured at 3, 6, and 12 months after discharge from the ICU using a questionnaire (SF-36). A linear mixed model was used to analyze changes over time and Wilcoxon Signed Rank Tests were used to compare the 12-months results to an age and gender matched reference population in Sweden. Linear regression analyses were performed to explore the impact on HRQoL from background variables.

RESULTS

Of 447 patients eligible for the study, 276 patients (62%) answered SF-36 at least once at 3, 6 or 12 months after ICU care and were included in the study. HRQoL improved over time but was still significantly lower at 12 months compared to the reference population. Female gender, age <75 years, living single, and ICU-stay of more than 14 days were associated with lower HRQoL.

CONCLUSION

General surgical ICU patients reports low HRQoL 1 year after ICU stay. The impaired HRQoL could be a long-lasting problem with major consequences for the individual, family, and society.

High prevalence of peripheral arterial disease in patients with obstructive sleep apnoea

INTRODUCTION

Obstructive sleep apnoea (OSA) merits increasing attention as cardiovascular risk factor. Whereas carotid and coronary artery disease have been associated with OSA, occurrence of peripheral arterial disease (PAD) in OSA remains undefined.

METHODS

We screened 100 patients with suspected OSA for PAD. After polysomnography, each patient underwent standardized angiological testing including ankle-brachial index (ABI), central pulse wave velocity, pulse wave index and duplex sonography.

RESULTS

Among total study population, PAD prevalence accounted for 88%, of those 68% had asymptomatic plaques and 20% were symptomatic Fontaine ≥ IIa. In confirmed OSA, prevalence raised up to 98%. Except for smoking habits, distribution of established risk factors did not differ between OSA groups (patients without, mild, intermediate and severe OSA). Presence of plaque, Fontaine PAD stages and intermittent claudication exhibited significant gain with increasing AHI. A logistic regression model revealed that age (OR = 1.199, 95% CI [1.066; 1.348]) and the logarithmically transformed AHI (OR = 5.426, 95% CI [1.068; 27.567]) had the strongest influence on plaque presence. Central pulse wave velocity as marker of arterial stiffness was positively correlated with AHI.

CONCLUSION

OSA is associated with a high prevalence of PAD. This implies substantial diseasés under-recognition and a presumable atherogenic role of OSA in the pathogenesis of PAD. However, vasoprotective impact of OSA treatment remains to be determined.

Detection of adeno- and lentiviral (HIV1) contaminations on laboratory surfaces as a tool for the surveillance of biosafety standards

AIMS

As a biosafety laboratory, we survey the handling of adenovirus type 5 (Ad5) and HIV1-derived lentivirus in contained-use facilities in Switzerland to identify insufficiencies of the safety precautions taken by the laboratories.

METHODS AND RESULTS

In the past 9 years, we took 430 swab samples from various types of surfaces in research laboratories. Samples were examined for Ad5 contaminations by real-time PCR and infectivity assay or for the presence of lentivirus (HIV1) nucleic acids by real-time (RT) PCR. Samples collected from centrifuges did not only contain Ad5 DNA more frequently but also exhibited higher numbers of Ad5 and lentiviral (HIV1) DNA copies than swabs from any other area of sampling. Five of ten samples containing infectious Ad5 particles or lentivirus (HIV1) RNA were found in samples taken from centrifuges. Ad5 contamination rates were higher in the tube holder and lower on the inner wall of the rotor chamber in centrifuges that were fitted with aerosol tight covers compared to centrifuges without covers.

CONCLUSIONS

Our results allowed the comparison of hygiene standards of different laboratories and lead to the identification of centrifuges as hotspots for contaminations.

SIGNIFICANCE AND IMPACT OF THE STUDY

Based on our results, we propose to use the collected data as a tool for rating future swab results. Furthermore, the amount of Ad5 and HIV1-derived lentivirus DNA could serve as an indicator of the level of good laboratory practice in contained-use laboratories handling these viral vectors.

GENOMICS: Sanger Will Sequence Zebrafish Genome

As the international human genome project nears completion, the Sanger Centre in Cambridge, U.K., has settled on a new effort to keep its sequencing machines humming: the genome of the zebrafish, a model organism much loved by developmental geneticists. After nearly 4 years of lobbying biomedical funding agencies, scientists who study the 4-centimeter Danio rerio are delighted.

Sam68 haploinsufficiency delays onset of mammary tumorigenesis and metastasis

The Src-associated substrate in mitosis Sam68 is a KH type RNA-binding protein known to be a substrate of numerous tyrosine kinases, and often referred to as a STAR (signal transduction activator of RNA) protein. Herein, we observed that Sam68-null mice display mammary gland and the uterine development defects. Moreover, we report that Sam68 haploinsufficiency impedes mammary tumor onset in vivo driven by the potent mammary-targeted polyoma middle T-antigen (MMTV-PyMT) oncogene. The effect was cell autonomous as the Sam68 knockdown in PyMT-transformed cell lines also delayed tumorigenesis and metastasis formation in nude mice. Interestingly, tumor extracts isolated from PyMT/Sam68(+/-) mice compared with PyMT/Sam68(+/+) mice contained activated Src and FAK kinases. These findings suggest that Sam68 may be a modulator of tyrosine kinase activity in vivo and a signaling requirement for mammary tumorigenesis and metastasis.

[Invasive giant pituitary adenomas]

7 cases of pituitary adenomas with the pronounced signs of invasive growth, confirmed by MRI, clinical and intraoperative observations. Invasive growth of adenomas was related to neither the structure of the tumor, the degree of anaplasia, or the nature of a generated hormone.

Interaction between bunk management and monensin concentration on finishing performance, feeding behavior, and ruminal metabolism during an acidosis challenge with feedlot cattle

Two commercial feedlot experiments and a metabolism study were conducted to evaluate the effects of monensin concentrations and bunk management strategies on performance, feed intake, and ruminal metabolism. In the feedlot experiments, 1,793 and 1,615 steers were used in Exp. 1 and 2, respectively, in 18 pens for each experiment (six pens/treatment). Three treatments were evaluated: 1) ad libitum bunk management with 28.6 mg/kg monensin and clean bunk management strategies with either 2) 28.6 or 3) 36.3 mg/kg monensin. In both experiments, 54 to 59% of the clean bunk pens were clean at targeted clean time, or 2200, compared with 24 to 28% of the ad libitum pens. However, only 13% of the pens were clean by 2000 in Exp. 1 (summer), whereas 44% of the pens in Exp. 2 (winter) were clean by 2000. In Exp. 1, bunk management and monensin concentration did not affect carcass-adjusted performance. In Exp. 2, steers fed ad libitum had greater DMI (P < 0.01) and carcass-adjusted ADG (P < 0.01) but feed efficiency (P > 0.13) similar to that of clean bunk-fed steers. Monensin concentration had no effect on carcass-adjusted performance (P > 0.20) in either experiment. A metabolism experiment was conducted with eight fistulated steers in a replicated 4 x 4 Latin square acidosis challenge experiment. An acidosis challenge was imposed by feeding 125% of the previous day's DMI, 4 h later than normal. Treatments consisted of monensin concentrations (mg/kg) of 0, 36.7, 48.9, or 36.7 until challenged and switched to 48.9 on the challenge day and 4 d following. Each replicate of the Latin square was managed with separate bunk management strategies (clean bunk or ad libitum). Feeding any concentration of monensin increased number of meals and decreased DMI rate (%/h) (P < 0.12) for the 4 d following the acidosis challenge. Meal size, pH change, and pH variance were lower (P < 0.10) for steers fed monensin with clean bunk management. However, no monensin effect was observed for steers fed ad libitum. Bunk management strategy has the potential to decrease DMI and ADG when steers managed on a clean bunk program are restricted relative to traditional, ad libitum bunk programs. Monensin helps control intake patterns for individuals, but increasing concentration above currently approved levels in this study seemed to have little effect.

Long-term clinical effectiveness of oral implants in the treatment of partial edentulism. Seven-year life table analysis of a prospective study with ITI dental implants system used for single-tooth restorations

One hundred and eight-seven ITI implants were prospectively followed from November 1992 to July 2000, in order to evaluate the clinical efficiency and the long-term prognosis in 109 partially edentulous patients (69 women and 40 men; average age 41.3 years). Of these 187 implants, 69.5% were placed in the mandible and 30.5% in the maxilla. After a healing period that ranged from three to six months, the osseointegrated implants (n = 184) were restored with single crowns. Three implants were extracted prior to loading the fixture and were considered early failures. Each implant was reassessed on a yearly basis, both clinically and radiographically. The results of the investigation, which were evaluated according to predefined success criteria, were reviewed in accordance with a life table method. During the follow-up, six cases were deemed to be late failures. In each of these cases, a suppurative infection of the peri-implant tissue was diagnosed: in one implant, the infection could not be eradicated and the implant was removed. When 11 drop-outs were included in the analysis, the cumulative survival and success rates for the whole sample group were 96.77% and 93.6%, respectively. When only prosthetically loaded implants were considered, the results increased to 99.35% for the cumulative survival rate and 96.18% for the cumulative success rate. The analysis on disaggregated data showed better results for maxillary restorations (survival rate 100%) in comparison to mandible restorations (survival rate 95.11%). It was concluded that, under standard anatomic conditions (bone site height > 8 mm, thickness > 6 mm), prosthetic restoration of partially edentulous patients with the ITI system can be described as a reliable and efficient therapy in the long term.

Regiospecific phosphohydrolases from Dictyostelium as tools for the chemoenzymatic synthesis of the enantiomers D-myo-inositol 1,2,4-trisphosphate and D-myo-inositol 2,3,6-trisphosphate: non-physiological, potential analogues of biologically active D-myo-inositol 1,3,4-trisphosphate

A new de novo synthesis of the enantiomeric pair D-myo-inositol 1,2,4-trisphosphate and D-myo-inositol 2,3,6-trisphosphate is described. Starting from enantiopure dibromocyclohexenediol, several C2 symmetrical building blocks were synthesized which gave access to D-myo-inositol 1,2,4,5-tetrakisphosphate and D-myo-inositol 1,2,3,6-tetrakisphosphate. Exploiting the high regiospecificity of two partially purified phosphohydrolases from Dictyostelium, a 5-phosphatase and a phytase, the inositol tetrakisphosphates were converted enzymatically to the target compounds. Their potential to modulate the activity of Ins3,4,5,6P4 1-kinase was investigated and compared with the effects of D-myo-inositol 1,3,4-trisphosphate.

Stem cell research. Reports give green light in Australia, Israel

BERLIN AND MELBOURNE--After 2 years of deliberation, an Australian government committee has endorsed legislation that would allow both human embryonic stem cell research and the derivation of ES cells from unwanted embryos created during fertility treatments. And in Israel, another country at the forefront of work on ES cells, a national bioethics committee has approved both the derivation of ES cells and research into therapeutic cloning.

Trehalose metabolism in Arabidopsis: occurrence of trehalose and molecular cloning and characterization of trehalose-6-phosphate synthase homologues

Axenically grown Arabidopsis thaliana plants were analysed for the occurrence of trehalose. Using gas chromatography-mass spectrometry (GC-MS) analysis, trehalose was unambiguously identified in extracts from Arabidopsis inflorescences. In a variety of organisms, the synthesis of trehalose is catalysed by trehalose-6-phosphate synthase (TPS; EC 2.4.1.15) and trehalose-6-phosphate phosphatase (TPP; EC 3.1.3.12). Based on EST (expressed sequence tag) sequences, three full-length Arabidopsis cDNAs whose predicted protein sequences show extensive homologies to known TPS and TPP proteins were amplified by RACE-PCR. The expression of the corresponding genes, AtTPSA, AtTPSB and AtTPSC, and of the previously described TPS gene, AtTPS1, was analysed by quantitative RT-PCR. All of the genes were expressed in the rosette leaves, stems and flowers of Arabidopsis plants and, to a lower extent, in the roots. To study the role of the Arabidopsis genes, the AtTPSA and AtTPSC cDNAs were expressed in Saccharomyces cerevisiae mutants deficient in trehalose synthesis. In contrast to AtTPS1, expression of AtTPSA and AtTPSC in the tps1 mutant lacking TPS activity did not complement trehalose formation after heat shock or growth on glucose. In addition, no TPP function could be identified for AtTPSA and AtTPSC in complementation studies with the S. cerevisiae tps2 mutant lacking TPP activity. The results indicate that while AtTPS1 is involved in the formation of trehalose in Arabidopsis, some of the Arabidopsis genes with homologies to known TPS/TPP genes encode proteins lacking catalytic activity in trehalose synthesis.