Akutna toksičnost veterinarskih i poljoprivrednih formulacija organofosfata diklorvosa i diazinona u pilića

Formulation components of organophosphate insecticidal preparations might affect their toxic action in animals. The objective of this study was to examine and compare the acute toxicity and cholinesterase inhibition in seven to 14-day-old chicks dosed orally with dichlorvos and diazinon in standard veterinary and agricultural formulations. The acute (24 h) oral median lethal doses (LD50) of the formulations were determined using the up-and-down method. Respective LD50 of dichlorvos of the veterinary and agricultural formulations in chicks were 11.1 mg kg-1 and 6.51 mg kg-1 and those of diazinon 6.4 mg kg-1 and 6.7 mg kg-1. Plasma and brain cholinesterase activities were measured by electrometry after in vivo and in vitro exposure to organophosphates. The chicks showed signs of cholinergic toxicosis within one hour of dosing. Dichlorvos (8 mg kg-1) and diazinon (4 mg kg-1) in the veterinary and agricultural formulation signifi cantly reduced both plasma and brain cholinesterase activities in the chicks. The veterinary formulation of dichlorvos reduced plasma ChE by 60 % and agricultural by 40 % and brain ChE by 93 % and 87 %, respectively. In contrast, ChE inhibition by diazinon in the agricultural formulation of diazinon was stronger than by the veterinary formulation; 72 % vs. 64 % in plasma and 97 % vs. 80 % in the brain, respectively. The highest in vitro inhibitions were observed with dichlorvos in the agricultural formulation (50 %) in the brain samples and with diazinon in the agricultural formulation (52 %) in the plasma samples. While they exist, differences between formulations cannot be taken as a rule and further investigations should inventory the toxicity of standard veterinary and agricultural organophosphate formulations in addition to the known data for pure forms.Sastojci formulacija mogu djelovati na toksičnost organofosfatnih insekticidnih pripravaka u životinja. Cilj je ovog istraživanja bio ispitati i usporediti akutnu inhibiciju kolinesteraza u pilića starih 7 do 14 dana koji su na usta primili organofosfatne insekticide diklorvos i diazinon u odgovarajućim formulacijama za veterinarsku odnosno poljoprivrednu primjenu. Dvadesetčetverosatna akutna letalna doza (LD50) diklorvosa bila je 11,1 mg kg-1 u veterinarskim odnosno 6,51 mg kg-1 u poljoprivrednim formulacijama, a diazinona 6,4 mg kg-1 odnosno 6,7 mg kg-1. Do kolinergičke toksikoze u pilića došlo je jedan sat nakon primjene. Nakon izlaganja organofosfatima in vivo i in vitro izmjerena je aktivnost kolinesteraza u plazmi i mozgu s pomoću elektrometrije. Oralne doze diklorvosa (8 mg kg-1) odnosno diazinona (4 mg kg-1) putem veterinarskih odnosno poljoprivrednih formulacija značajno su smanjile aktivnost kolinesteraza u plazmi i mozgu pilića. In vitro su također oba organofosfata inhibirala aktivnost kolinesteraza, bez obzira na formulaciju. Poljoprivredna formulacija diklorvosa izazvala je najjaču inhibiciju (50 %) u mozgu pilića, dok je poljoprivredna formulacija diazinona najjače inhibirala (52 %) aktivnost u plazmi. Ovo istraživanje pokazuje da različite formulacije organofosfatnih insekticida mogu dovesti do različita otrovanja i različito djelovati na kolinesteraznu aktivnost u mozgu i plazmi

Instantaneous ambiguity resolution in global-navigation-satellite-system-based determination applications: A multivariate constrained approach

Carrier phase integer ambiguity resolution is the key to high-precision Global Navigation Satellite System (GNSS) positioning, navigation, and attitude determination. It is the process of resolving the unknown cycle ambiguities of the carrier phase data as integers. After ambiguity resolution, precise baseline estimates become available, which can be used to derive the attitude of a multi-antenna platform. The purpose of this contribution is to present and test a rigorous GNSS-based attitude determination method, optimally exploiting the complete set of geometrical constraints. The key to this new method is an extension of the popular LAMBDA method: the multivariate constrained LAMBDA. The method estimates the integer ambiguities and the platform’s attitude in an integralmanner, fully exploiting the known body geometry of the multi-antenna configuration. As a result, the ambiguity resolution performance is greatly improved. The method is extensively tested addressing the most challenging scenario: single-epoch single-frequency GNSS observations are processed without any filtering, external aid, or dynamic modeling

The role of cell differentation in controlling cell multiplication and cancer

It has been suggested that cancer ought to be regarded as a disease of cell differentiation. In multicellular organisms, indeed, the control of cell multiplication is linked to cell specialization: During the process of differentiation embryonic cells, while cycling, acquire the ability to perform specialized functions. This ability is incompatible with cell cycling which, as a consequence, is repressed with forthcoming differentiation. Thus, the number of amplification divisions that occur during the period while differentiation is proceeding decides on the number of specialized cells produced. The progress in differentiation, contrary to usual assumptions, is accompanied by an increase in the cellular content of cytoplasm. The reason must be that cell specialization requires a specific amount and array of membrane-bounded cytoplasmic structures. Since the multiplication of these structures depends on membranous templates, their amount increases only if more cytoplasm is produced per cycle than required for a doubling, thus constituting an intracellular timer of differentiation: The larger the net rate of cytoplasmic growth per cell cycle, the fewer cycles occur. Extracellular signals modulate cell multiplication by altering the net rate of cytoplasmic growth. Each persisting alteration, however, that reduces this rate to zero, prevents differentiation, and thus causes the cells to retain embryonic capabilities and to initiate cancer. Cancer cells can be induced to differentiate and cease proliferation by support of cytoplasmic growth. This corroborates the suggestion that cancer must be regarded as a disease of cell differentiation and our conclusion that cancer is caused by a deficiency in cytoplasmic growth. Support of the latter must be an efficient principle in cancer therapy although limited by the organism's dependence on cell renewal

Efficacy of minimally invasive techniques for enhancement of fracture healing: evidence today

The successful treatment of nonunions represents a major challenge for orthopaedic surgeons. Lately, ongoing advances made in the field of molecular medicine and molecular biology have increased our understanding of the pathways and involvement of mediators surrounding the bone healing process. As a result, the surgeon’s armamentarium has been increased in terms of options for intervention. This article aims to provide an overview of minimally invasive techniques applicable in the treatment of nonunions of fractures