Study on the allelopathic effect of Amaranthus retroflexus L., Datura stramonium L. and Panicum miliaceum L. on the germination of maize

Der Pflanzenextrakt von Amaranthus retroflexus zeigte eine hemmende Wirkung auf die Entwicklung der Kotyledonen und Wurzeln von Mais in Petrischalen-Versuchen. In Topfversuchen reduzierten die Trockenpflanzenreste von Amaranthus die Keimung von Mais weitestgehend. Auch zeigte sich ein negativer Effekt auf Sprosslänge und -gewicht, während ein positiver Effekt auf die Wurzellänge und -gewicht deutlich wurde.Eine 2,5 %ige Konzentration von Datura-stramonium-Pflanzenextrakten zeigte eine stimulierende Wirkung, aber die 5 %- und 7,5 %igen Extrakte hemmten die Spross- und Wurzelentwicklung von keimendem Mais. Trotz 60 %iger Keimungsrate zeigte die Einarbeitung von trockenen Pflanzenresten in den Boden keine signifikanten Auswirkungen auf die Sprossentwicklung, aber es wurde eine stimulierende Wirkung auf die Wurzelentwicklung beobachtet. Das Trockengewicht der Wurzeln überschritt jedoch die Kontrollwerte nur bei einer Konzentration von 7,5 %.Der Pflanzenextrakt von Panicum miliaceum wirkte stimulierend auf die Spross- und Wurzelentwicklung von Mais. Die trockenen Pflanzenteile im Boden der Töpfe behinderten die Keimung von Mais, aber signifikante Effekte auf die Trieb- und Wurzellängen konnten nicht nachgewiesen werden. Bei der Konzentration von 7,5 % war das Trockengewicht der Triebe höher als die Kontrollwerte, aber alle anderen Boden-Pflanzenteil-Raten hatten niedrigere Werte.Plant extracts of Amaranthus retroflexus showed an inhibitory effect on the development of both cotyledons and rootlets of maize in petri dish trials. In pot experiments, among the three examined weeds, dry plant residues of Amaranthus hindered the germination of maize to the greatest extent. It showed also a negative effect on the shoot length and weight, while there was a positive effect on the root length and weight.A 2.5% concentration of Datura stramonium plant extracts showed a stimulative effect, but the 5% and 7.5% extracts inhibited the shoot and root development of germinating maize. In spite of a 60% germination rate, the incorporation of dry plant residues into the soil did not show any significant effect on the development of shoots, but a stimulative effect on root development was observed. However, the dry weight of roots exceeded the control values only at a concentration of 7.5%.Plant extract of Panicum miliaceum had a stimulative effect on the shoot and root development of maize. Dry plant parts in the soil of the pots hindered the germination of maize, but significant effects on the shoot and root lengths could not be proven. At the 7.5% ratio the dry weight of shoots was higher than the control values, but all the other soil-plant part ratios caused lower values

Allelopathic effects of Abutilon theophrasti, Asclepias syriaca and Panicum ruderale on maize

Abutilon theophrasti, Asclepias syriaca und Panicum ruderale sind in Ungarn sehr wichtige invasive Unkräuter. Sie können ernste Schäden verursachen, da diese über eine gute Konkurrenzfähigkeit verfügen. Das Ziel unseres Experiments ist es, die allelopathische Wirkung der Wurzel- und Triebtinkturen auf die Keimung des Maises und das Wachstum der Keimpflanzen zu untersuchen. Das sogenannte „Bioassay-Experiment“ wurde im Jahre 2015 im Laboratorium durchgeführt. Die Tinkturen wurden aus lufttrockenen und gemahlenen Wurzeln und Trieben mit Wasser mit einer Konzentration von 2,5, 5 und 7 % angefertigt. Die Maiskörner (Sorte Cornelius) wurden in eine Petrischale gegeben, dann wurden sie mit 15 ml Tinktur behandelt und bei 20 °C in Dunkel-Thermostate gelegt. Am 7. Tag wurde das Keimungsprozent festgestellt, sowie die Länge und die Masse der primären Wurzel und des primären Triebs wurden gemessen. Die statistische Analyse wurde durch eine Varianzanalyse auf einem Faktor durchgeführt. Die Trieb- und Wurzeltinkturen von Abutilon theophrasti reduzierten die Keimung sowie das Wachstum der primären Wurzel und des primären Triebes, abnehmende Länge und Masse wurden gemessen. Die Tinkturen von Asclepias syriaca ergaben die gleiche Wirkung. Diese Behandlungen reduzierten die Keimung und das Wachstum der Mais-Keimpflanzen. Die Triebtinktur von Panicum ruderale führte zu kürzeren Trieben und einer geringeren der Triebmasse, darüber hinaus hemmte sie die Keimung des Maises. Die Wurzeltinkturen reduzierten die Länge und Masse des Triebes sowie die Keimung, jedoch übten sie auf die Wurzelentwicklung keinen signifikanten Einfluss aus. Es wurde festgestellt, dass die allelopathische Wirkung von A. theophrasti und A. syriaca stärker war als die von P. ruderale. In Verbindung mit der Allelopathie von A. theophrasti und A. syriaca berichten auch andere Veröffentlichungen über signifikante Ergebnisse. Vorzugsweise hinderten die Wurzeltinkturen das frühe Wachstum von Mais. Mit höherer Konzentration der Tinkturen verstärkte sich auch die allelopathische Wirkung.Abutilon theophrasti, Asclepias syriaca and Panicum ruderale are very important invasive weed species in Hungary. These can cause hard damages firstly in row space crops, because these have good competition ability. The aim our experiment was to study the allelopathic effect of watery extracts from roots and shoots on germination and growth of maize seedlings. Bioassay experiments were made in the laboratory in 2015. Extracts from air dried and grinded roots and shoots of weeds were made with water in 2.5, 5 and 7.5% concentrations. Maize (Cornelius) seeds were put into Petri-dishes, after that they were treated with 15 mL solutions, and put into a thermostat at 20 °C in the dark. After 7 days of germination, % and length and weight of primary roots and shoots of seedlings were determined. The statistical analysis has been done one-factorial analysis of variance. Shoot and root extracts of Abutilon theophrasti decreased germination-% and growth of primary roots and shoots of seedlings. Watery extracts from Asclepias syriaca resulted in similar effects; these treatments reduced germination and growth of seedlings. Shoot extract of Panicum ruderale caused shorter shoots and less shoot weight, and hindered the germination of maize. Root extract decreased shoot length and weight, and also germination, but root development was not influenced significantly. We established that allelopathic effects of A. theophrasti and A. syriaca were stronger than those of P. ruderale. Other publications reported significant results connected to allelopathy of A. theophrasti and A. syriaca. Mainly the root extracts inhibited the early growth of maize. Allelopathic effects were stronger with increasing concentrations of solutions

The implications of Panicum miliaceum in the viral epidemiology of cereals

Common millet (Panicum miliaceum L.) is a spreading weed in Hungary, it can be found mostly on maize fields, but it has been investigated, that it is more and more often occurring in other cultivated plants, like potato, wheat, and other cereals. It can widely spread because of the lack of seed dormancy. This weed is a close relative to wheat, so the aim of the experiment was to investigate, which wheat viruses can infect of the common millet (Panicum miliaceum L.). Forty-five millet leaf samples were collected from fields in 2014 and 2015 near Keszthely, Zala County, and 35 leaf samples in 2016 near Keszthely. After the collection, the samples were immediately frozen and stored at - 20○C. The DAS ELISA serological method was used to determine wheat viruses from the leaves. Among the 80 collected leaf samples 27 gave positive results. Simple virus infection were realised in 20 samples. 10 times Wheat streak mosaic virus (WSMV), 7 times Wheat dwarf virus (WDV), 6 times Barley stripe mosaic virus (BSMV), 5 times Barley yellow dwarf virus (BYDV), and 1 time Brome streak mosaic virus (BStMV) was detected. Brome mosaic virus (BMV) was detected in 4 samples. Complex infections were detected in 5 samples: in 3 samples WDV and WSMV, and in 1 sample WDV, WSMV and BYDV, and in 1 sample BMV, WDV and BYDV. After the first investigation other samples were collected, in order to continue the examination. These results indicate that Panicum miliaceum can play a major role in the distribution of different cereal virus species

A simple standard technique for labyrinthectomy in the rat: A methodical communication with a detailed description of the surgical process

Aims: Labyrinthectomized rats are suitable models to test consequences of vestibular lesion and are widely used to study neural plasticity. We describe a combined microsurgical–chemical technique that can be routinely performed with minimum damage. Methods Caudal leaflet of the parotis is elevated. The tendinous fascia covering the bulla is opened frontally from the sternomastoid muscle’s tendon while sparing facial nerve branches. A 4 mm diameter hole is drilled into the bulla’s hind lower lateral wall to open the common (in rodents) mastoid-tympanic cavity. The cochlear crista (promontory) at the lower posterior part of its medial wall is identified as a bony prominence. A 1 mm diameter hole is drilled into its lower part. The perilymphatic/endolymphatic fluids with tissue debris of the Corti organ are suctioned. Ethanol is injected into the hole. Finally, 10 µL of sodium arsenite solution (50 µM/mL) is pumped into the labyrinth and left in place for 15 min. Simple closure in two layers (fascia and skin) is sufficient. Results and conclusion All rats had neurological symptoms specific for labyrinthectomy (muscle tone, body position, rotatory movements, nystagmus, central deafness). Otherwise, their behavior was unaffected, drinking and eating normally. After a few days, they learned to balance relying on visual and somatic stimuli (neuroplasticity)

A végtagi vénás adaptáció mechanizmusai tartós orthosztatikus és inverz-orthosztatikus gravitációs terheléshez egészséges és kórós körülmények között = Mechanism of adaptation to long-term orthostatic and inverse-orthostatic gravitation loading in the extremity veins

Bizonyítékok sorát tártuk fel annak igazolására ill. megerősítésére, hogy orthosztatikus jellegű krónikus gravitációs terhelésre - esetenként inverz-orthosztatikus (mikrogravitás modell) is - patkány alsó végtagi vénák mindhárom rétege adaptációs jellegű microvesiculáris, myogen ill. innervációs változásokkal válaszol. E kísérletes eredmények egy részét, pl. a vénás endothelium micro-vesiculáris és a media myogen válaszai vonatkozásában, már humán érvizsgálatokkal is sikerült megerősíteni. Emberi kutatásokra fejlesztett új, non-invazív módszerünkkel alapvető információkat nyertünk számos nagyvéna disztenzibilitásának testhelyzet-, nyomás-, régió- és korfüggő sajátosságairól egészséges és beteg (postthrombotikus) egyének vonatkozásában. Mivel a vérkeringési rendszer gravitációs alkalmazkodó képességének megítélésében meghatározó fontos az artériás vérnyomás viselkedése, kombinált tilt-telemetriás módszereket és protokollokat fejlesztettünk ki rövid- és hosszú-távú orthosztatikus, valamint inverz-orthosztatikus kardiovaszkuláris hatások jellemzőinek ill. mechanizmusainak tanulmányozására éber patkányokban. Meglepetésre, mindkét testhelyzetben artériás hipertenzió a válasz, amely sympathicus efferens függő és specifikus gravitációs hatásokhoz kötött (nemspecifikus stressz effektusát kizártuk). Igazoltuk, hogy e válasz vestibulo-sympathicus reflex, amely néhány nap alatt adaptálódik a tilt pozícióhoz. Publikált munkák száma összesen 83, ebből 22 eredeti nemzetközi (IF: 23,531). | Experimental evidence has been provided to show that all three layers of rat hind limb veins respond to chronic orthostatic or inverse-orthostatic body position (ground-base model of microgravity) with adaptive microvesicular, myogenic, and neural changes. A part of these results (microvesicular properties of the venous endothelium, enhanced myogenic response) has been verified in human studies too. Using a new method developed by us for human investigations, information has been collected to characterize the distensibility of different healthy and diseased (postthrombotic) large veins in respect of body position, blood pressure, body region, and age. Taking into consideration, that arterial pressure response to gravitation stress is decisive in the ability of the organism to adapt, we developed combined techniques and protocols using telemetry, tilt-cages with appropriate rat models for studying the nature and mechanism of short- and long-term cardiovascular reactions to orthostatic and inverse-orthostatic effects. Interestingly, both of these body positions resulted in hypertension which proved to be dependent on intact sympathetic innervation and was connected with gravitation effects. Non-specific stress was excluded. It has been proven that vestibulo-sympathetic reflex activation plays a role in these blood pressure responses which adapt to the tilt-positions in a few days. Total number of publications: 83 with 22 original papers in international journals (IF: 23.531)

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome

OBJECTIVE: To investigate the vascular dysfunction caused by insulin resistance in polycystic ovary syndrome (PCOS) and the effectiveness of vitamin D in an animal model. DESIGN: Controlled experimental animal study. SETTING: Animal laboratory at a university research institute. ANIMAL(S): Thirty female Wistar rats. INTERVENTION(S): Rats were divided into groups at age 21-28 weeks. Twenty of them were subjected to dihydrotestosterone (DHT) treatment (83 μg/d); ten of them also received parallel vitamin D treatment (120 ng/100 g/wk). Oral glucose tolerance tests with insulin level measurements were performed. Gracilis arterioles were tested for their contractility as well as their nitric oxide (NO)-dependent and insulin-induced dilation using pressure arteriography. MAIN OUTCOME MEASURE(S): Several physiologic parameters, glucose metabolism, and pressure arteriography. RESULT(S): DHT treatment increased the passive diameter of resistance arterioles, lowered norepinephrine-induced contraction (30.1 ± 4.7% vs. 8.7 ± 3.6%) and reduced acetylcholine-induced (122.0 ± 2.9% vs. 48.0 ± 1.4%) and insulin-induced (at 30 mU/mL: 21.7 ± 5.3 vs. 9.8 ± 5.6%) dilation. Vitamin D treatment restored insulin relaxation and norepinephrine-induced contractility; in contrast, it failed to alter NO-dependent relaxation. CONCLUSION(S): In DHT-treated rats, in addition to metabolically proven insulin resistance, decreased insulin-induced vasorelaxation was observed and was improved by vitamin D treatment without affecting NO-dependent relaxation. The reduction in insulin-induced dilation of arterioles is an important as yet undescribed pathway of vascular damage in PCOS and might explain the clinical effectiveness of vitamin D treatment

Arteriolar biomechanics in a rat polycystic ovary syndrome model - effects of parallel vitamin D3 treatment.

To clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on arteriolar biomechanics in a rat model and the possible modulatory role of vitamin D3. METHODS AND RESULTS: The PCOS model was induced in female Wistar rats by ten-weeks DHT treatment. Arteriolar biomechanics was tested in arterioles by pressure arteriography in control as well as DHT- and DHT with vitamin D3-treated animals in contracted and passive conditions. Increased wall stress and distensibility as well as increased vascular lumen were detected after DHT treatment. Concomitant vitamin D3 treatment lowered the mechanical load of the arterioles and restored the vascular diameter. CONCLUSION: The hyperandrogenic state resulted in more rigid, less flexible arteriolar walls with increased vascular lumen compared with controls. DHT treatment caused eutrophic remodelling of gracilis arteriole. These prehypertensive alterations caused by chronic DHT treatment were mostly reversed by concomitant vitamin D3 administration

Effects of vitamin D3 derivative--calcitriol on pharmacological reactivity of aortic rings in a rodent PCOS model.

Abstract BACKGROUND: The aim of this study was to examine the effects of the hyperandrogenic state in dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS), the vascular responses to different vasoactive agents, and the modulatory role of vitamin D3. METHODS: APCOS model was induced by DHT application in 20 female Wistar rats. Ten of the DHT treated rats simultaneously received calcitriol treatment. After 10 weeks, myographs were used to test the reactivity of isolated thoracic aortic rings to norepinephrine and acetylcholine. Thereafter, the vascular rings were incubated with the NO-synthase blocker (nitro-L-arginine methyl ester) or the cyclooxygenase inhibitor (indomethacin) for 20 min, and the effects of norepinephrine and acetylcholine were re-evaluated. RESULTS: Norepinephrine-induced vasoconstriction was enhanced after DHT treatment, but this effect was attenuated by calcitriol administration. Vasorelaxation of DHT-treated thoracic aortic rings was impaired, but this could be partly reversed by calcitriol application. Impaired NO-dependent vasorelaxation in DHT-treated animals was mostly reversed by concomitant calcitriol administration, but this effect was diminished by prostanoid-dependent vasoconstriction. CONCLUSIONS: These studies show that the enhanced sensitivity to vasoconstrictors and impaired NO-dependent vasorelaxation in hyperandrogenic PCOS rats could be partially reversed by calcitriol treatment