Sulia patologia sperimentale daActinoplanes philippinensis couch

Sommario Dopo una breve descrizione delle caratteristiche culturali e morfologiche dell'A. philippinensis, si riferiscono i risultati sperimentali ottenuti inoculandolo per via endoperitoneale, endovenosa, endotesticolare ed endocranica in ratti albini maschi del peso medio di 150 g. Morte spontanea si è verificata in circa un animale su tre.I principali reperti sono: elettivo interessamento di determinati organi in rapporto alle varie vie d'inoculazione: peritoneo, pancreas e tessuti peripancreatici (nell'inoculazione endoperitoneale), polmone (nell'inoculazione endovenosa), testicolo (nell'inoculazione endotesticolare), encefalo (nell'inoculazione endocranica), mentre, indifferentemente nei diversi gruppi di animali, appaiono interessati da processi patosici aspecifici fegato, milza e reni. Ovunque abbia preso impianto l'actinomicete allo studio, il processo evolve, con modalità perfettamente analoghe e costanti, da quadri iniziali di flogosi acuta, con possibile componente necrotica del parenchima invaso, verso il quadro tipico del granuloma fungino produttivo, con esito tardivo sclero-cicatriziale.L'A. philippinensis animalizzato è caratterizzato: dall'assenza di zoosporangi o di elementi ad essi equivalenti; dimostra una discreta patogenicità nei confronti del ratto albino, con quadri istologici simili a quelli provocati da altri Actinomiceti patogeni, ed una scarsa tendenza invasiva e diffusiva.

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Experimental pathology byActinoplanes philippinensis couch

Summary The morphological and cultural characters ofA. philippinensis are described, and experimental results of intraperitoneal, intravenous, intratesticular and intracranial inoculations on male rats are referred to. One out of three animals died spontaneously. The outstanding results are: some organs are selectively damaged by the lesions, viz: peritoneum, pancreas, peripancreatic tissues (after i.p. inoculation), lungs (after i.v. inoculation), testiculi (after intratesticular inoculation), brain (after intracranial inoculation), while in all animals the liver, spleen and kidneys show some signs of aspecific lesions. Wherever theActinoplanes is present and grows the pathologic processes develop in the same way, with a constant and uniform pattern, from initial acute inflammation, with possible necrosis of the parenchyma, into typical productive fungous granuloma leading to fibrosis. A. philippinensis in tissues is characterized by lack of zoosporangia or their equivalent, by some degree of pathogenicity for the rat with histological pictures resembling those produced by other pathogen Actinomycetes and by its slight tendency to invasion and diffusion.

     

Action of volatile substances liberated from couch grass

A study was made of the action of volatile substances liberated from the rhizome of couch grass on wheat seedlings. The experiments were made in a closed atmosphere in glass vessels with continual removal of expired CO₂ and the addition of O₂. Volatile substances liberated from couch grass produced numerous morphological and physiological changes in wheat seedlings. They caused retarding of the growth of overground parts and roots, the excessive formation of root hairs, curling of the roots and bending of the coleoptiles. The respiratory rate was higher in the leaves and roots of the experimental wheat seedlings than in the controls. The changes observed were similar to those produced by hydrocarbons of the ethylene series, which are well documented in the literature.     

The use of sterile nursing in hematology]

By means of own experiences gathered in the treatment of 18 patients in Life Island the problems and limits of this therapy method are represented. Microbiological findings are described in detail and commented. Sterile care is an essential part of an effective therapy of haemoblastoses, malignant lymphoma, and some solid tumours, particularly in the aplastic phase.     

The evolutionary biology of sterile soldiers in aphids

The discovery of a sterile soldier caste in aphids by Shigeyuki Aoki offered behavioural ecologists new and interesting subjects for the study of insect sociality. Quantitative studies on the behaviour of soldiers and the population and genetic consequences are, however, scant. This review summarizes the distribution and peculiarities of sterile soldiers in different aphid taxa and also reports on phenomena that may relate to the evolution of aphid soldiers.     

The cytology of the male sterile lathyrus odoratus

Summary The cytological abnormalities caused by the genetic factor for male sterility inLathyrus odoratus are described and discussed. Data from a small backcross showing the amount of recombination between malesterile and light axil are given.With 2 plates     

The sterile immune response during hepatic ischemia/reperfusion

Hepatic ischemia and reperfusion elicits an immune response that lacks a microbial constituent yet poses a potentially lethal threat to the host. In this sterile setting, the immune system is alarmed by endogenous danger signals that are release by stressed and dying liver cells. The detection of these immunogenic messengers by sentinel leukocyte populations constitutes the proximal trigger for a self-perpetuating cycle of inflammation, in which consecutive waves of cytokines and chemokines orchestrate the influx of various leukocyte subsets that ultimately confer tissue destruction. This review focuses on the temporal organization of sterile hepatic inflammation, using surgery-induced trauma as a template disease state.     

Modeling of couch transmission in the RayStation treatment planning system

PurposeTo present our methods and results regarding the modeling of a carbon fiber couch (Varian Exact IGRT) in the RayStation treatment planning system (TPS).MethodsThree geometrical-models (GMs) were implemented in the TPS to represent the three different regions of the couch (thick, medium and thin). The materials and densities of each GM component were tuned to maximize the agreement between measured and calculated attenuations. Moreover, a couch computed-tomography (CT) scan was acquired and dosimetrically compared with the GMs. For validation, plan-specific quality assurance (QA) of VMAT plans (TG-119 cases, 5 prostate and 5 H&N clinical cases) was performed by comparing measured dose distributions with doses computed with and without including the GMs in the TPS.ResultsCouch attenuations up to 4.3% were measured (energy: 6MV). Compared to couch CT, GMs could be modified to optimize the agreement with measurements and reduce dependence on the dose grid resolution. For both couch CT and GM, absolute deviations between measured and calculated attenuations were within 1.0%. When including the GMs in plan-specific QA, global 2%/2 mm γ-pass rates showed an average improvement of 4.8% (p-value < 0.001, max +18.6%). The couch reduced the mean dose to targets by up to 2.4% of the prescribed dose for prostate cases and up to 1.4% for H&N cases.ConclusionsRayStation accurately considers the implemented couch GMs replicating measured attenuations within an uncertainty of 1.0%. Materials and densities are proposed for the Varian Exact IGRT couch. The results obtained justify introducing couch GMs in clinical routine.     

Assessment of dose error due to nylon mesh of treatment couch

PurposeThis study aims at the assessment of dose error in patients undergoing radiotherapy due to treatment couch of Co-60 teletherapy unit.Materials and methodsIn this study beam attenuation due to treatment couch of Co-60 unit was measured in air for different gantry angles and field sizes. Polymethylmethacrylate (PMMA) phantom was used to estimate the effect of depth on attenuation. Impact of couch on surface dose was also evaluated.ResultsBeam attenuation due to couch was in the range of 0.5–28% for different gantry angles with standard field size of 10 × 10 cm² with optimum position of metallic cranks. Maximum attenuation (29%) was observed with smallest field size i.e. 5 × 5 cm². Beam attenuation has been found higher in phantom as compared to that in air However, no particular trend of attenuation has been noted with varying depth of phantom. A 6% increase in surface dose has also been observed due to couch insertion for normal beam incidence. Maximum error of 80% is also note-worthy for most unfavorable situation of irradiation at 180 degree through the metallic cranks.ConclusionIt has been determined that ignoring the treatment couch and its accessories can result in dose error of 0.5–80%, depending on gantry angle, field size and position of couch accessories. Therefore, consideration of dose error due to couch during treatment planning is recommended.     

The sterile release method for population control with interspecific competition

A differential equations model of competing species with the release of sterile individuals of one of the species is examined. The system is found to have two positive steady states for certain parameter values; one of these is stable and the other is unstable. The system is quite resilient around the stable steady state. The release of steriles causes the nontarget species to increase in numbers. There exists a value of the release rate above which the pest species collapses to extinction. The existence of the competitor species assists the sterile release program since the pest equilibrium at any release rate is lower with the competitor species present than without it; in addition the release rate required to cause collapse of the pest species is lower with the competitor species present than without it. The effects of the parameters on the ease of eradication were examined. It was found that the ideal competitor species should have a high rate of increase, a large carrying capacity and exert strong competitive depression on the pests. The ideal pest would have a low rate of increase, a low carrying capacity and be a poor competitor.     

Remating in Ceratitis capitata sterile males: Implications in sterile insect technique programmes

Sterile insect technique (SIT) is used, among other biological control tools, as a sustainable measure for the management of Ceratitis capitata Wiedemann (Diptera: Tephritidae) in many agricultural regions where this pest can trigger severe economic impacts. The tendency of wild females to remate multiple times has been deeply studied; it has been a common point of controversy when evaluating SIT programmes. Nevertheless, the remating potential of the released sterile males remains unknown. Here, under laboratory conditions, the remating capability of mass-reared sterile males was determined. Wild-type virgin females were offered to sterile males (Vienna-8 strain), which had the opportunity to mate up to four consecutive times. The remating assays were carried out at 24 hr, 48 hr, 4 days and 7 days after the first mating. At the end of each tested time period, males were divided according to their mating response, mated or unmated, and subsequently reused for the next round of mating assays. The frequency of successful remating in each tested time period was obtained. Insemination was confirmed by determining the sperm transfer in mated female spermathecae by quantitative real-time PCR. Our results demonstrate that 73% of the mass-reared sterile males were able to remate 24 hr after the first mating, 55% of which remated again the day after. Close to 25% of the V8 sterile males tended to copulate in all of the four mating opportunities. The qPCR analysis of the spermathecae contents verified an effective transfer of V8 sperm to wild females with every mating; 99% of copulations resulted in sperm transfer. These findings shed light on the remating potential of V8 sterile males, an aspect until now underestimated in many SIT programmes.