New evidence for the Ontong Java Nui hypothesis.

The formation of the Ontong Java Nui super oceanic plateau (OJN), which is based on the model that the submarine Ontong Java Plateau (OJP), Manihiki Plateau (MP), and Hikurangi Plateau (HP) were once its contiguous fragments, could have been the largest globally consequential volcanic event in Earth's history. This OJN hypothesis has been debated given the paucity of evidence, for example, the differences in crustal thickness, the compositional gap between MP and OJP basalts and the apparent older age of both plateaus relative to HP remain unresolved. Here we investigate the geochemical and 40Ar-39Ar ages of dredged rocks recovered from the OJP's eastern margin. Volcanic rocks having compositions that match the low-Ti MP basalts are reported for the first time on the OJP and new ~ 96-116 Ma and 67-68 Ma 40Ar-39Ar age data bridge the temporal gap between OJP and HP. These results provide new evidence for the Ontong Java Nui hypothesis and a framework for an integrated tectonomagmatic evolution of the OJP, MP, and HP. The isotopic data imply four mantle components in the source of OJN that are also expressed in present-day Pacific hotspots sources, indicating origin from (and longevity of) the Pacific Large Low Shear-wave Velocity Province.

High-power laser experiment on developing supercritical shock propagating in homogeneously magnetized plasma of ambient gas origin.

A developing supercritical collisionless shock propagating in a homogeneously magnetized plasma of ambient gas origin having higher uniformity than the previous experiments is formed by using high-power laser experiment. The ambient plasma is not contaminated by the plasma produced in the early time after the laser shot. While the observed developing shock does not have stationary downstream structure, it possesses some characteristics of a magnetized supercritical shock, which are supported by a one-dimensional full particle-in-cell simulation taking the effect of finite time of laser-target interaction into account.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest.

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Tauroursodeoxycholic Acid Attenuates Diet-Induced and Age-Related Peripheral Endoplasmic Reticulum Stress and Cerebral Amyloid Pathology in a Mouse Model of Alzheimer's Disease.

BACKGROUND: Obesity and diabetes are well-established risk factors of Alzheimer's disease (AD). In the brains of patients with AD and model mice, diabetes-related factors have been implicated in the pathological changes of AD. However, the molecular mechanistic link between the peripheral metabolic state and AD pathophysiology have remained elusive. Endoplasmic reticulum (ER) stress is known as one of the major contributors to the metabolic abnormalities in obesity and diabetes. Interventions aimed at reducing ER stress have been shown to improve the systemic metabolic abnormalities, although their effects on the AD pathology have not been extensively studied. OBJECTIVES: We examined whether interventions targeting ER stress attenuate the obesity/diabetes-induced Aß accumulation in brains. We also aimed to determine whether ER stress that took place in the peripheral tissues or central nervous system was more important in the Aß neuropathology. Furthermore, we explored if age-related metabolic abnormalities and Aß accumulation could be suppressed by reducing ER stress. METHODS: APP transgenic mice (A7-Tg), which exhibit Aß accumulation in the brain, were used as a model of AD to analyze parameters of peripheral metabolic state, ER stress, and Aß pathology in the brain. Intraperitoneal or intracerebroventricular administration of taurodeoxycholic acid (TUDCA), a chemical chaperone, was performed in high-fat diet (HFD)-fed A7-Tg mice for ~1 month, followed by analyses at 9 months of age. Mice fed a normal diet were treated with TUDCA by drinking water for 4 months and intraperitoneally for 1 month in parallel, and analyzed at 15 months of age. RESULTS: Intraperitoneal administration of TUDCA suppressed ER stress in the peripheral tissues and ameliorated the HFD-induced obesity and insulin resistance. Concomitantly, Aß levels in the brain were significantly reduced. In contrast, intracerebroventricular administration of TUDCA had no effect on the Aß levels. Peripheral administration of TUDCA was also effective against the age-related obesity and insulin resistance, and markedly reduced amyloid accumulation. CONCLUSIONS: Interventions that target peripheral ER stress might be beneficial therapeutic and prevention strategies against brain Aß pathology associated with metabolic overload and aging.

Perirenal fat thickness as a predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer.

BACKGROUND: Laparoscopic distal gastrectomy is used widely in surgery for gastric cancer. Excess visceral fat can limit the ability to dissect the suprapancreatic region, potentially increasing the risk of local complications, particularly pancreatic fistula. This study evaluated perirenal fat thickness as a surrogate for visceral fat to see whether this was related to complications after laparoscopic distal gastrectomy. METHODS: Perirenal fat thickness was measured dorsal to the left kidney as an indicator of visceral fat in patients with gastric cancer who underwent laparoscopic distal gastrectomy. Patients were divided into two groups: those with and those without complications. The relationship between perirenal fat thickness and postoperative complications was evaluated. RESULTS: The optimal cut-off value for predicting morbidity using adipose tissue thickness was 10·7 mm; a distance equal to or greater than this was considered a positive perirenal fat thickness sign (PTS). A positive PTS showed a significant correlation with visceral fat area. Multivariable analysis found that a positive PTS was an independent risk factor for complications (hazard ratio 4·42, 95 per cent c.i. 2·31 to 8·86; P < 0·001). CONCLUSION: Perirenal fat thickness as an indicator of visceral fat was an independent predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer.

ANTECEDENTES: La gastrectomía distal laparoscópica se utiliza ampliamente en la cirugía del cáncer gástrico. El exceso de grasa visceral puede limitar la capacidad para disecar la región suprapancreática, aumentando potencialmente riesgo de complicaciones locales, especialmente de fistula pancreática. El propósito de este estudio fue evaluar el grosor de la grasa perirrenal como marcador subrogado de grasa visceral para determinar si se relacionaba con complicaciones tras gastrectomía distal laparoscópica. MÉTODOS: El grosor de la grasa perirrenal se midió a nivel dorsal del riñón izquierdo como indicador de grasa visceral en pacientes con cáncer gástrico sometidos a gastrectomía distal laparoscópica. Los pacientes fueron divididos en dos grupos: aquellos con y sin complicaciones. Se evaluó la relación entre grosor de la grasa perirrenal y las complicaciones postoperatorias. RESULTADOS: El punto de corte óptimo para predecir la morbilidad utilizando el grosor del tejido adiposo fue de 10,7 mm, por lo que una distancia igual o mayor a este nivel fue considerado como signo positivo de engrosamiento de la grasa perirrenal (peri-renal fat thickness sign, PTS). Un PTS positivo mostró una correlación significativa con el área de grasa visceral. Los análisis multivariables demostraban que un PTS positivo era un factor de riesgo independiente para complicaciones (razón de oportunidades, odds ratio 4,418; i.c. del 95% 2,307-8,855; P < 0,001). CONCLUSIÓN: El grosor de grasa perirrenal como indicador de la grasa visceral fue un predictor independiente de complicaciones postoperatorias tras una gastrectomía distal laparoscópica por cáncer gástrico.

Laparoscopic proximal gastrectomy with double-flap technique versus laparoscopic subtotal gastrectomy for proximal early gastric cancer.

BACKGROUND: Laparoscopic proximal gastrectomy with double-flap technique (LPG-DFT) and laparoscopic subtotal gastrectomy (LSTG) may replace laparoscopic total gastrectomy (LTG) for proximal early gastric cancer. The aim of this study was to evaluate short- and long-term outcomes after LPG-DFT and LSTG. METHODS: Patients who underwent LPG-DFT or LSTG at the Cancer Institute Hospital in Tokyo between January 2006 and April 2015 were included in this retrospective study. Operative procedures were selected based on the distance from the cardia to the proximal boundary of the tumour, tumour location and predicted remnant stomach volume. Patient characteristics, surgical data, markers of postoperative nutritional status, such as blood chemistry and bodyweight loss, and endoscopic findings were compared between procedures. The main study outcome was nutritional status. RESULTS: A total of 161 patients (LPG-DFT 51, LSTG 110) were included. Types of postoperative complication occurring more than 30 days after surgery differed between the two procedures. Remnant stomach ulcers, including anastomotic ulcers, were observed only after LPG-DFT, whereas complications involving the small intestine, such as internal hernia or small bowel obstruction, occurred more frequently after LSTG. Values for total protein, albumin, prealbumin and bodyweight loss were comparable between the two procedures at 36 months after surgery. Haemoglobin concentrations were higher after LPG-DFT than after LSTG at 24 months (13·4 versus 12·8 g/dl respectively; P = 0·045) and 36 months (13·5 versus 12·8 g/dl; P = 0·007) after surgery. The rate of Los Angeles grade B or more severe reflux oesophagitis was comparable. CONCLUSION: LPG-DFT and LSTG for proximal early gastric cancer have similar outcomes, but different types of complication.

ANTECEDENTES: La gastrectomía proximal laparoscópica con técnica de doble derivación (double flap technique, LPG-DFT) y la gastrectomía subtotal laparoscópica (laparoscopic subtotal gastrectomy, LsTG) pueden sustituir a la gastrectomía total laparoscópica (laparoscopic total gastrectomy, LTG) para el cáncer gástrico precoz (early gastric cancer, EGC) proximal. El objetivo de este estudio fue evaluar los resultados a corto y a largo plazo tras LPG-DFT y LsTG. MÉTODOS: En este estudio retrospectivo se incluyeron pacientes que fueron sometidos a LPG-DFT o LsTG en el Hospital del Instituto del Cáncer de Tokio entre enero 2006 y abril 2015. Las técnicas quirúrgicas se seleccionaron en base a la distancia entre el cardias y el borde proximal del tumor, localización del tumor, y el volumen previsto del remanente gástrico. Las características de los pacientes, datos quirúrgicos, marcadores del estado nutricional postoperatorio, tales como la bioquímica sanguínea y la pérdida de peso corporal (body weight loss, BWL), y los hallazgos endoscópicos se compararon entre las técnicas. El resultado principal del estudio fue el estado nutricional. RESULTADOS: Se incluyeron un total de 161 pacientes (LPG-DFT 51, LsTG 110). Los tipos de complicaciones postoperatorias que aparecieron a más de 30 días después de la cirugía variaron entre ambas técnicas. Las úlceras en el remanente gástrico, incluyendo úlceras anastomóticas, solo se observaron tras una LPG-DFT, mientras las complicaciones relacionadas con el intestino delgado, como la hernia interna o la obstrucción de intestino delgado, sucedió con más frecuencia tras una LsTG. Los valores de proteínas totales, albúmina, prealbúmina, y BWL fueron comparables entre ambas técnicas a los 36 meses después de la cirugía. Las concentraciones de hemoglobina fueron más altas tras una LPG-DFT que tras una LsTG a los 24 (13,4 versus 12,8 mg/dL, P = 0,045) y 36 meses (13,5 versus 12,8 mg/mL, P = 0,007) después de la cirugía. Las incidencias de esofagitis por reflujo grado B Los Angeles o más grave fueron comparables. CONCLUSIÓN: La LPG-DFT y la LsTG para el EGC proximal presentan resultados bastante similares, pero difieren en el tipo de complicaciones.

Biomechanical Comparison between Volar Plate Fixator and Nonbridge External Wrist Fixator.

Intra-articular distal radius fractures are difficult to reduce and maintain by nonoperative means. ORIF leaves implants in the patient long after the fracture is healed. External fixation can stabilize the reduced fracture and leaves no long-term implants. The nonbridging fixator (NBX) will provide better reduction and comparable rigidity of fixation to a volar plate for a 5-fragment, OTA 23 C3.2 distal radius fracture. A 5-part distal radius fracture was created in 5 pairs of cadaver arms. One arm was randomly fixed with the NBX fixator; the matched pair was fixed with a volar plate (VPS). Fluoroscopic images recorded the extremes of passive volar-dorsiflexion range of motion (ROM) and radial-ulnar deviation ROM. Each arm was loaded with an axial force at a constant displacement rate until failure. The average reduction of radial tilt achieved for the NBX group was 13.8 ± 4.8° and 6.3 ± 4.7° for VPS; radial length: 3.4 ± 3.7 mm for NBX and 1.9 ± 1.0 mm for VPS; volar tilt: 26.3 ± 12.4° for NBX and 14.0 ± 13.5° for VPS. For NBX, ROM was slightly less after fixation than before fracture. ROM with volar plating was greater after fracture. The peak axial load for NBX was 925 ± 445 N; for VPS, 2,152 ± 1023 N. NBX had minimal effect on ROM and provided adequate strength and restoration of alignment at least as good as VPS for this 5-part fracture model.

Rayleigh-Taylor instability experiments on the LULI2000 laser in scaled conditions for young supernova remnants.

We describe a platform developed on the LULI2000 laser facility to investigate the evolution of Rayleigh-Taylor instability (RTI) in scaled conditions relevant to young supernova remnants (SNRs) up to 200 years. An RT unstable interface is imaged with a short-pulse laser-driven (PICO2000) x-ray source, providing an unprecedented simultaneous high spatial (24µm) and temporal (10 ps) resolution. This experiment provides relevant data to compare with astrophysical codes, as observational data on the development of RTI at the early stage of the SNR expansion are missing. A comparison is also performed with FLASH radiative magnetohydrodynamic simulations.

Laser-driven shock compression of "synthetic planetary mixtures" of water, ethanol, and ammonia.

Water, methane, and ammonia are commonly considered to be the key components of the interiors of Uranus and Neptune. Modelling the planets' internal structure, evolution, and dynamo heavily relies on the properties of the complex mixtures with uncertain exact composition in their deep interiors. Therefore, characterising icy mixtures with varying composition at planetary conditions of several hundred gigapascal and a few thousand Kelvin is crucial to improve our understanding of the ice giants. In this work, pure water, a water-ethanol mixture, and a water-ethanol-ammonia "synthetic planetary mixture" (SPM) have been compressed through laser-driven decaying shocks along their principal Hugoniot curves up to 270, 280, and 260 GPa, respectively. Measured temperatures spanned from 4000 to 25000 K, just above the coldest predicted adiabatic Uranus and Neptune profiles (3000-4000 K) but more similar to those predicted by more recent models including a thermal boundary layer (7000-14000 K). The experiments were performed at the GEKKO XII and LULI2000 laser facilities using standard optical diagnostics (Doppler velocimetry and optical pyrometry) to measure the thermodynamic state and the shock-front reflectivity at two different wavelengths. The results show that water and the mixtures undergo a similar compression path under single shock loading in agreement with Density Functional Theory Molecular Dynamics (DFT-MD) calculations using the Linear Mixing Approximation (LMA). On the contrary, their shock-front reflectivities behave differently by what concerns both the onset pressures and the saturation values, with possible impact on planetary dynamos.

Magnetic reconnection driven by electron dynamics.

Magnetic reconnections play essential roles in space, astrophysical, and laboratory plasmas, where the anti-parallel magnetic field components re-connect and the magnetic energy is converted to the plasma energy as Alfvénic out flows. Although the electron dynamics is considered to be essential, it is highly challenging to observe electron scale reconnections. Here we show the experimental results on an electron scale reconnection driven by the electron dynamics in laser-produced plasmas. We apply a weak-external magnetic field in the direction perpendicular to the plasma propagation, where the magnetic field is directly coupled with only the electrons but not for the ions. Since the kinetic pressure of plasma is much larger than the magnetic pressure, the magnetic field is distorted and locally anti-parallel. We observe plasma collimations, cusp and plasmoid like features with optical diagnostics. The plasmoid propagates at the electron Alfvén velocity, indicating a reconnection driven by the electron dynamics.

Contribution of pharmacists with expertise in infectious diseases to appropriate individualized vancomycin dosing.

BACKGROUND/AIM: Dose adjustment of vancomycin (VCM) is important in improving clinical outcomes and avoiding adverse effects such as nephrotoxicity. Although pharmacist-managed VCM therapy has been reported to optimize treatment, there are no studies focused on pharmacist expertise to date. In this study, we compared the contribution of pharmacists trained for infectious diseases and general pharmacists to dose adjustment of VCM. PATIENTS AND METHODS: We retrospectively investigated VCM trough concentration after dose adjustment by both trained (n = 67) and general (without special training for infectious diseases; n = 85) pharmacists. We also compared the incidence of nephrotoxicity during VCM treatment in both groups. RESULTS: The rate of achieving therapeutic VCM trough concentration (10-20 µg/mL) was higher in the trained group than in the control group (80.6 vs. 54.1%, p < 0.001). No significant differences in incidence of nephrotoxicity were observed between the two groups (p = 0.744). Trained pharmacists could contribute more successfully to the achievement of therapeutic VCM concentration ranges without increasing the risk of nephrotoxicity.

Randomized clinical trial of duct-to-mucosa versus invagination pancreaticojejunostomy after pancreatoduodenectomy.

BACKGROUND: The postoperative pancreatic fistula (POPF) rate for duct-to-mucosa and invagination anastomosis after pancreatoduodenectomy is still debated. The aim of this RCT was to investigate the POPF rate for duct-to-mucosa versus invagination pancreaticojejunostomy. METHODS: Patients were stratified by pancreatic texture and diameter of the main pancreatic duct and randomized to the duct-to-mucosa or invagination group. The primary endpoint was the rate of clinically relevant POPF (defined as grade B or C). Secondary endpoints were suture material cost for pancreaticojejunostomy, drain insertion duration and duration of postoperative hospital stay. RESULTS: Some 120 patients undergoing pancreatoduodenectomy were included following consent. Clinically relevant POPF developed in six of 59 patients (10 per cent) in the invagination group and in 14 of 61 patients (23 per cent) in the duct-to-mucosa group (P = 0·077). Duration of drain insertion (6 versus 7 days respectively; P = 0·027) and postoperative hospital stay (19 versus 24 days; P = 0·015) were shorter in the invagination group. Subgroup analysis for 61 patients with a soft pancreas revealed a lower rate of clinically relevant POPF in the invagination group (10 per cent versus 42 per cent in the duct-to-mucosa group; P = 0·010). Among 20 patients with a clinically relevant POPF, the six patients in the invagination group had a shorter duration of drain insertion (38·5 days versus 49 days for 14 patients in the duct-to-mucosa group; P = 0·028) and postoperative hospital stay (42 versus 54·5 days respectively; P = 0·028). CONCLUSION: This study did not demonstrate a superiority of invagination over duct-to-mucosa pancreaticojejunostomy in the risk of POPF. However, in high-risk patients with a soft pancreas, invagination may reduce the risk of clinically relevant POPF compared with duct-to-mucosa. Registration number: UMIN000005890 (http://www.umin.ac.jp).

Use of endoscopy to determine the resection margin during laparoscopic gastrectomy for cancer.

BACKGROUND: It can be difficult to determine the transection line during totally laparoscopic surgery for early gastric cancer owing to lack of tactile feedback. This retrospective cohort study aimed to assess the role of intraoperative endoscopy in determining the resection margin in totally laparoscopic gastrectomy. METHODS: Consecutive patients with histologically confirmed gastric cancer who underwent laparoscopic gastrectomy between March 2012 and July 2015 were eligible. Preoperative placement of marking clips and intraoperative endoscopy were performed to determine the resection margin. Frozen-section analyses were also performed to confirm the absence of cancer cells at the surgical margin. Success was defined as the proportion of specimens with all clips present and by the proportion of resections with a negative surgical margin following initial transection. RESULTS: Total laparoscopic gastrectomy with intraoperative endoscopy was performed in 522 patients; a total of 662 surgical margins were analysed. The overall success rate was 99·8 per cent (661 of 662 margins). The success rate of achieving a negative surgical margin during the initial transection was 98·9 per cent (550 of 556 margins). CONCLUSION: Preoperative placement of marking clips and intraoperative endoscopy is helpful in the determination of a safe surgical margin in patients with gastric cancer who undergo laparoscopic gastrectomy.

Validation of the 8th Edition of the AJCC TNM Staging System for Gastric Cancer using the National Cancer Database.

BACKGROUND: The 8th edition AJCC gastric cancer staging manual was refined using Japanese and Korean data from the International Gastric Cancer Association (IGCA). This study evaluated the eighth edition's validity for U.S. METHODS: National Cancer Database (NCDB) was used to obtain data on gastric cancer patients diagnosed from 2004 to 2008 who underwent surgery and to examine differences in stage grouping and survival between AJCC 7th and 8th editions. Discrimination of models derived from NCDB and IGCA data was compared. RESULTS: Of 12,041 patients, median age was 65, 57.6% were male, median lymph nodes retrieved was 2 (0-76), 30.9% underwent distal/partial gastrectomy, and 49.8% received no adjuvant treatment. The 8th edition differed in that T1-T3 disease was upstaged with N3b, T4aN3a was downstaged from IIIC to IIIB, and T4bN0 and T4aN2 were downstaged from IIIB to IIIA. These changes resulted in increased patients in IIIA (1436 in the 7th edition to 2310 in the 8th) and IIIB (1737-1896) and decreased in IIIC (2100-1067). This also resulted in lower median survival for IIIA (28.7-25.0 months), IIIB (19.6-17.4), IIIC (13.7-11.8). The concordance index for the 8th edition applied to NCDB data was 0.719 [95% confidence interval (CI) 0.703-0.734), which is comparable to that for the 8th edition developed from IGCA data (0.775, 95% CI 0.770-0.780) and the 7th edition applied to NCDB data (0.720, 95% CI 0.704-0.735). CONCLUSIONS: The 8th edition is valid for U.S. populations, showing clear separation of data with preservation of group order.

Molecular diversity among viroids infecting chrysanthemum in India.

Association of Chrysanthemum stunt viroid (CSVd) and Chrysanthemum chlorotic mottle viroid (CChMVd) with the Chrysanthemum plants exhibiting severe stunting, distinct yellow leaf mottling, and chlorosis was detected in the main chrysanthemum-growing regions of India. Sequence analysis of 90 cDNA clones obtained for CSVd and CChMVd, representing the chrysanthemum-growing regions of India, revealed the high degree of sequence variation throughout the genome under natural conditions. Additionally, all the analyzed CChMVd clones revealed the presence of UUUC in the tetraloop, a signature of symptomatic variants in susceptible cultivars. Phylogenetic analysis revealed that Indian CSVd is closely related to European isolates from ornamentals, whereas CChMVd clustered along with the isolates reported from the East Asian countries.

Lafutidine, a histamine H2 receptor antagonist with mucosal protective properties, attenuates 5-fluorouracil-induced intestinal mucositis in mice through activation of extrinsic primary afferent neurons.

Intestinal mucositis accompanied by severe diarrhea is one of the most common side effects during cancer chemotherapy. Lafutidine, a histamine H2 receptor antagonist with mucosal protective properties via sensory afferent neurons, is used for the treatment of upper gastrointestinal diseases. The present study investigated the effects of lafutidine on 5-fluorouracil (5-FU)-induced intestinal mucositis induced in mice. Male C57BL/6 wild-type (WT), sensory deafferented mice, and transient receptor potential vanilloid subfamily 1 knockout (TRPV1KO) mice were used. Animals were administered 5-FU once daily, while lafutidine and famotidine were administered twice daily for 6 days. Repeated administration of 5-FU caused severe intestinal mucositis, characterized by shortening of villi and destruction of crypts and was accompanied by diarrhea and body weight loss. Daily administration of lafutidine reduced the severity of intestinal mucositis, diarrhea and body weight loss in a dose-dependent manner, while famotidine had no effect on intestinal mucositis. The preventive effects of lafutidine were completely abolished in sensory deafferented and TRPV1-KO mice. Lafutidine significantly suppressed 5-FU-increased MPO activity and inflammatory cytokine expression on day 6, but not apoptosis induction in intestinal crypts on day 1. Lafutidine induced Alcian Blue and PAS-positive mucus production in the small intestine. These findings suggest that lafutidine attenuates 5-FU-induced intestinal mucositis, most likely by increasing mucus production via activation of sensory afferent neurons. Furthermore, intact TRPV1 signaling is essential for the activation of sensory afferent neurons induced by lafutidine. Therefore, lafutidine is more useful than other common antacids for the treatment of intestinal mucositis during cancer chemotherapy.

Propagation and some physiological effects of Citrus bark cracking viroid and Apple fruit crinkle viroid in multiple infected hop (Humulus lupulus L.).

The hop metabolome important for the brewing industry and for medical purposes is endangered worldwide due to multiple viroid infections affecting hop physiology. Combinatorial biolistic hop inoculation with Citrus bark cracking viroid (CBCVd), Apple fruit crinkle viroid (AFCVd), Hop latent viroid, and Hop stunt viroid (HSVd) showed a low CBCVd compatibility with HSVd, while all other viroid combinations were highly compatible. Unlike to other viroids, single CBCVd propagation showed a significant excess of (-) over (+) strands in hop, tomato, and Nicotiana benthamiana, but not in citruses. Inoculation of hop with all viroids led to multiple infections with unstable viroid levels in individual plants in the pre- and post-dormancy periods, and to high plant mortality and morphological disorders. Hop isolates of CBCVd and AFCVd were highly stable, only minor quasispecies were detected. CBCVd caused a strong suppression of some crucial mRNAs related to the hop prenylflavonoid biosynthesis pathway, while AFCVd-caused effects were moderate. According to mRNA degradome analysis, this suppression was not caused by a direct viroid-specific small RNA-mediated degradation. CBCVd infection led to a strong induction of two hop transcription factors from WRKY family and to a disbalance of WRKY/WDR1 complexes important for activation of lupulin genes.