Local dose

Single local dose of 5-20 Gy to various salivary glands Dose-dependent decrease in salivary flow rate and sodium composition of saliva at 10 Gy and higher, changes were irreversible 46... 

Precision of total dose Localization of dose Can achieve very high local doses Unexposed control tissue from same animal... 

Docebenone has shown anti-inflammatory effects in several animal models following local dosing phorbol ester-induced oedema and neutrophil influx in mouse skin [208,209], arachidonate-induced plasma extravasation in rabbit skin [210], the pleural reversed passive Arthus reaction in rats [211], and GPB [212], An oral dose of 80 mg/kg reduced infarct size, LTB4 levels and neutrophil infiltration in a rat myocardial infarction model [213,214], and in a rat brain ischaemia-reperfusion model oedema and LTC4 levels were reduced at 200 mg/kg [107]. Significant, but not dramatic, improvement in nasal symptoms was seen in humans following 150 mg of docebenone twice daily for 8 weeks [215], but there was no effect on bronchial hyperresponsiveness to acetylcholine in asthmatics [216]. 

This chapter first reviews and discusses selected research on local dose aspects of ozone toxicity, the morphology of the respiratoty tract and mucus layer, air and mucus flow, and the gas, liquid, and tissue components of mathematical models. Next, it discusses the approaches and results of the few models that exist. A similar review was recently done to defme an analytic framework for collating experiments on the effects of sulfur oxides on the lung. Pollutant gas concentrations are generally stated in parts per million in this chapter, because experimental uptake studies are generally quoted only to illustrate behavior predicted by theoretical models. Chapter 5 contains a detailed discussion of the conversion from one set of units to another. 

To model the uptake of ozone and other gases for establishing dose-response relationships at specific sites, local dose must be accurately deBned. In the past, this has not been done for specific sites. Fairchild... 

We measure the ability of radiation to cause harm in reins. Lethal doses of radiation begin at 500 rems. A person has about a 50 percent chance of surviving a dose of this magnitude received over a short period of time. During radiation therapy, a patient may receive localized doses in excess of200 rems each day for a period of weeks (Figure 4.8). 

The physical appearance of radiation burns and thermal burns is the same. The difference lies not only in their etiology, but in the time it takes for the wound to appear. Thermal injury is often visible instantaneously or appears soon after a person is burned. Radiation injury can take days to weeks to appear, depending on the dose. A visible injury is an indication of a high localized dose of radiation and the wound must be decontaminated as in chemical injury. This localized radiation exposure can result in various changes to the skin, depending on the dose. Although the patient s wound may be contaminated, the patient and the wound are not radioactive. 

Therapeutic treatment of hyperthyroidism with I led to large local doses of several hundred Sv of p radiation, but with respect to leukaemia no significant difference was observed in comparison with untreated people. 

Local dose Whole body and gonad dose ... 

Figure 9.18 shows that the 5-pL infusion volume indeed provided localized dosing of the Gpi when biotinylated albumin was infused. The results of a 5-pL infusion of 50 mM quinolinic acid on the... 

Partial lung Precision and localization of total dose Can achieve very high local doses Unexposed control tissues from same animal Anesthesia Placement of dose Possible redistribution of material within lung Difficult In Interpretation of results Technically difficult Stress to animal Physiologic support... 

Some skin damage frequently accompanies ARS. However, the cutaneous syndrome can also result from localized acute radiation exposure to the skin, usually from direct handling of radioactive sources or from contamination of the skin or clothes (2,8) (see Figs. 4.1 and 4.2) With localized exposure, even with high doses, the victim frequently survives, because the whole body usually does not receive the localized dose. However, if a patient with localized radiation induced cutaneous injury has also received whole body irradiation from an external source, the cutaneous damage increases the risk for death from the whole body exposure (2). Patients with the hematopoietic syndrome due to whole body irradiation will recover more slowly, if at all, from cutaneous injury due to bleeding, infection and poor wound healing (2). 

There are basically two delivery routes for drugs intravenous delivery and intra-tumoral delivery [10, 15]. Intravenous delivery is being extensively used for the chemotherapeutic agent bleomycin, with good success. Indeed there are several aspects that make this a favorable soluhon. First, bleomycin does not readily enter cells. Therefore, an intravenous delivery will have a favorable toxicity profile despite whole-body exposure to the drug. Second, the increase in toxicity is very marked once direct access to the cell cytosol is provided thus even a limited local dose will exert a sufficient effect. Other drugs to be administered intravenously for delivery during electroporahon would need to be able to fulfill this criterion, in order to have both sufficient effects in the treated area as well as a favorable toxicity profile. 

Peyman et al. (35) hypothesized that the injection of antibiotic into an eye from which vitreous has been removed might increase the risk of toxicity. Lim demonstrated that the settling of aminoglycosides onto the retinal surface in vitrectomized eye did in fact predispose the eyes to higher local doses on the retinal surface and therefore to higher risk of toxicity (27). 

In some cases, local irradiation of some tissues is produced by the use of radioactive nuclides inmlanted in the tissue by means of needles or small capsules. For example, needles of "Sr— Y, pellets of Au, etc., have been inqilanted in the pituitary gland (for acromegalia, Cushing s disease, and cancer), in the breast (for breast cancer), in the prostate, and in the nerves (to reduce pain). The local dose may be lOO s of Sv. Also, radioactively labeled tumor seeking compounds are used. 

Saenger et al. (1968) studied 36 (XX) patients with hyperthyroidism (a cancer causing the thyroid to grow), of which 22 (X)0 were treated with (only / , no 7 local doses of several hundred Sv) while the rest underwent surgery or chemical therapy. Although the 1 patients received bone marrow doses of about 100 mSv, no difference was observed in relation to the non-irradiated group with respect to incidence of leukemia. 

The local dose level at the detector should not have too much influence on the processing. Otherwise, the software may react differently in different parts of the breast or produce different appearances if in successive acquisitions slightly different doses were used. 

Finally, mention should be made of the tfeatment of positton annihilation radiation and conversion electrons in the determination of Q values. The latter are treated as monoenergetic beta particles, and weighted according to their yields. In the case of annihilation radiation this has not been included in the evaluation of the beta dose to the skin since it contributes only an additional few per cent to the local dose to the basal layer. However, the 0.51 MeV gamma rays are included in the photon energy per disintegration used in the derivation of as discussed above. 

It is possible to circumvent problems arising from quercetin s apparent immobility when added to the basal end of a transport segment, by applying it or N PA as small local doses half-way up 20 mm long hypocotyl segments (Table 4). With this method both substances can be seen to interrupt the lAA transport stream and to inhibit basipetal auxin transport. Attempts to demonstrate perturbation of seedling gravitropism by quercetin have so far been unsuccessful. 

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