Decorporation Approach Following Rat Lung Contamination with a Moderately Soluble Compound of Plutonium Using Local and Systemic Ca-DTPA Combined Chelation

Decorporation efficacy of prompt pulmonary delivery of DTPA dry powder was assessed following lung contamination with plutonium nitrate and compared to an intravenous injection of DTPA solution and a combined administration of both DTPA compounds. In addition, efficacy of a delayed treatment was assessed. In case of either early or late administration, insufflated DTPA was more efficient than intravenously injected DTPA in reducing the plutonium lung burden due to its high local concentration. Prompt treatment with DTPA powder was also more effective in limiting extrapulmonary deposits by removing the early transportable fraction of plutonium from lungs prior its absorption into blood. Translocation of DTPA from lungs to blood may also contribute to the decrease in extrapulmonary retention, as shown by reduced liver deposit after delayed pulmonary administration of DTPA. Efficacy of DTPA dry powder was further increased by the combined intravenous administration of DTPA solution for reducing extrapulmonary deposits of plutonium and promoting its urinary excretion. According to our results, the most effective treatment protocol for plutonium decorporation was the early pulmonary delivery of DTPA powder supplemented by an intravenous injection of DTPA solution. Following inhalation of plutonium as nitrate chemical form, this combined chelation therapy should provide a more effective method of treatment than conventional intravenous injection alone. At later stages following lung contamination, pulmonary administration of DTPA should also be considered as the treatment of choice for decreasing the lung burden.     

Effect of age on the efficacy of Zn-diethylenetriaminepentaacetic acid therapy for removal of Am and Pu from beagles

Decorporation of intravenously injected monomeric 241Am and 237+239Pu by the administration of 30 mumole Zn-diethylenetriaminepentaacetic acid (DTPA)/kg each day beginning 2 weeks after radionuclide injection was compared in beagles entered into the experiment when 3 months (juveniles). 1.9 years (young adults), or 10 years (mature adults) old and studied for about 5 months. DTPA therapy was most effective in the juvenile dogs and least effective in the mature adults. Retention of 241Am in the liver decreased from a pretreatment value for adults of about 50% of the injected activity to about 10% in the mature adults and less than 1% in the young adults at 140 days of treatment, while the liver retention of juveniles decreased from pretreatment values of about 16% to undetectable levels by 28 days of treatment. Plutonium retention in the liver decreased from adult pretreatment levels of about 30% of the injected activity (corrected for radioactive decay) to near 10% in the mature adults and 6% in the young adults at 140 days of treatment, while juvenile liver retention decreased from pretreatment values near 15% to undetectable levels by 56 days of treatment. Nonliver Am retention (mainly skeleton) decreased in mature adults from pretreatment values of about 45% of the injected activity to near 25%, in young adults from 35 to 20%, and in juveniles from roughly 70 to 9% by 140 days of DTPA administration. Nonliver Pu retention decreased from pretreatment values of about 50% of the injected activity (corrected for radioactive decay) for mature and young adults to about 30% by 140 days and from 75 to 16% in juveniles over the time period.     

Chelation therapy of incorporated plutonium-238 and americium-241: comparison of LICAM(C), DTPA and DFOA in rats, hamsters and mice

The carboxylated catechoylamide 3,4,3-LICAM(C) was tested for removal of 238Pu and 241Am from small laboratory rodents. The effectiveness of treatment was compared with that of two ligand preparations approved for clinical use: calcium-trisodium diethylenetriaminepentaacetate (DTPA) and desferrioxamine (DFOA). With early treatment and at the dosage used clinically for the decorporation of actinides with DTPA (30 mumol/kg body weight) LICAM(C) was superior to DFOA but when compared with DTPA, the effect of LICAM(C) on 238Pu was greater only in bone; as little as 1 mumol LICAM(C)/kg was as effective as 30 mumol DTPA/kg. However, in all animals treated with LICAM(C) there was a large increase in the 238Pu content of the kidney. With 241Am the effect of DTPA was always superior to that of LICAM(C). The best overall results early (1 day) after injection of 238Pu and 241Am were achieved by a combination of a single injection of LICAM(C) and DTPA with subsequent continuous administration of DTPA in drinking water. LICAM(C) affected the retention of 238Pu even if given orally; the data suggested that about 3 per cent of ingested LICAM(C) was absorbed. When the beginning of treatment was delayed, LICAM(C) became equally effective or less effective than DTPA even as far as 238Pu retention in bone was concerned, but it still increased the accumulation of 238Pu in the kidneys.     

Enhanced decorporation of plutonium by DTPA encapsulated in small PEG-coated liposomes

The aim of the study was to demonstrate that decorporation of 238Pu is achieved more efficiently by an optimized liposomal formulation of diethylene triamine pentaacetic acid (DTPA) than by the usual free DTPA treatment. The optimized formulation consisted of polyethylene glycol-coated stealth liposomes with a mean diameter of 100 nm (SL-100 nm). Rats were intravenously injected with various Pu-phytate salt solutions in order to test different contamination conditions (activity and salt concentration) impacting liver kinetics and skeletal uptake of Pu. All treatments were given intravenously 1 h after contamination. Efficiency was evaluated 24 h, 7, 16 or 30 days later through their ability to promote Pu elimination and to reduce Pu burden in the skeleton and liver, the main organs of Pu deposition and radiotoxicological effects. Whatever the conditions of contaminations, a single injection of SL-100 nm (3.2 micromol kg(-1) DTPA) boosted urinary elimination of Pu to above 90% of the injected dose. In addition, liposomes strongly and significantly reduced the Pu burden of the liver and skeleton even 30 days after a single treatment: a dose of 0.3 micromol kg(-1) induced the same skeletal Pu reduction as four injections of free DTPA (30 micromol kg(-1)). A log dose-effect relation was found with SL-100 nm DTPA and Pu excretion in urine or Pu burden in the studied organs (liver, femurs, spleen and kidneys). This efficacy was attributed to an optimized targeting of DTPA to the main Pu retention organs and especially the liver.     

Removal of Pu and am from beagles and mice by 3,4,3-LICAM(C) or 3,4,3-LICAM(S)

Decorporation of Pu and Am by tetrameric catechoylamide (CAM) ligands has been investigated in beagles and mice. Eight dogs were injected intravenously (iv) with 237 + 239Pu(IV) + 241Am(III) citrate, and 30 min later, pairs of dogs were injected iv with 30 mumole/kg of 3,4,3-LICAM(C) [N1,N5,N10,N14-tetrakis(2,3-dihydroxy-5-sulfobenzoyl)tetr aazatetradecane, tetrasodium salt], 3,4,3-LICAM(S) [N1,N5,N10,N14-tetrakis(2,3-dihydroxy-4-carboxybenzoyl)te traazatetradecane, tetrasodium salt], CaNa3-DTPA, or each of the latter two ligands. Blood was sampled, and excreta were collected for 7 days, at which time the dogs were sacrificed and nuclide retention in liver and nonliver tissue was measured. Groups of five mice were each given 238Pu(IV) or 241Am(III) citrate iv; 3 min later 30 mumole/kg of a CAM ligand was injected intraperitoneally, mice were killed at 24 hr, and separated excreta and tissues were analyzed. In the dogs, average retention at 7 days of the injected Pu and Am, respectively, was as follows: 12 and 70% after treatment with a CAM ligand alone; 30 and 20% after DTPA; 12 and 20% after LICAM(S) plus DTPA; 90 and 89% without a ligand. In the mice, mean retention of the injected Pu and Am, respectively, was as follows: 14 and 66% after treatment with LICAM(C); 21 and 54% after LICAM(S); 91 and 87% without a ligand. In both species, about 99% of net Pu excretion (excretion with ligand - excretion without ligand) promoted in 24 hr by DTPA or LICAM(S) was in the urine, whereas about 10% of net Pu excretion promoted by the less hydrophilic LICAM(C) was in feces. Delayed excretion of both Am and Pu was significant in all ligand-treated dogs. Comparison of the nuclide content of tissues of ligand-treated mice with those of mice killed 3 min after nuclide injection indicated that the CAM ligands chelated circulating Pu and Am and prevented further deposition. In addition, the CAM ligands removed much of the presumably loosely bound Pu present in liver and skeleton at the time of ligand injection. LICAM(C) was more effective in removing Pu from liver and LICAM(S) was more effective in the skeleton. Moderate to severe uremia and histological evidence of cell killing in the distal tubules of the kidney were observed in the four dogs injected once with 30 mumole/kg of LICAM(S).(ABSTRACT TRUNCATED AT 400 WORDS)     

Effects of Chelates in Chemotherapy of Experimental Gas-Gangrene Toxemia

The relative ability of the calcium chelates of calcium disodium ethylenediaminetetraacetate (EDTA) and calcium trisodium ethylenetriaminepentaacetate (DTPA) to protect mice against lethal doses of Clostridium perfringens alpha-toxin was investigated. Their protective ability was assayed by the increase in survival time of mice which had been given large doses of toxin, and by determining the median protective dose of chelate that would protect mice against toxin at a minimum lethal dose of two. In both assay procedures, intraperitoneal, intravenous, and intracutaneous injections of toxin were utilized, and with each toxin injection route the protective ability of the chelate was determined with the three routes of injection. DTPA was 10 to 20 times more effective than EDTA with both types of assay procedure and with all injection routes. DTPA may be superior to EDTA as a protective agent not only because it binds zinc to a greater extent, but also because of its greater retention in the body and its ability to gain entrance into cells. It appears that DTPA may be of value as a therapeutic agent in gas-gangrene.     

Comparison of the pharmacokinetics of subcutaneous and intravenous administration of a phosphorothioate oligodeoxynucleotide in cynomolgus monkeys

The pharmacokinetics of subcutaneous (s.c.) administration of a phosphorothioate oligodeoxynucleotide (PS-ODN) was evaluated in cynomolgus monkeys. In a single dose study, monkeys were injected s.c. or intravenously (i.v.) with doses of either 1 or 5 mg/kg ISIS 2302. The bioavailability of s.c. injection ranged from 26% to 55% and appeared to be dependent on the concentration of the dosing solution rather than the dose. The bioavailability of a subcutaneously administered 5 mg/kg dose of ISIS 2302 was 55% using a 50 mg/ml dosing solution and only 26% using a 10 mg/ml dosing solution. Slow absorption from the s.c. injection site significantly blunted the maximal concentration (Cmax) compared with i.v. administration. The time to peak plasma concentration (Tmax) increased slightly with increasing dose, from 0.5 to 1 hour for the 1 mg/kg dose to 1 to 2.5 hours for the 5 mg/kg dose. Plasma half-lives were prolonged after s.c. administration, indicating more dependence on absorption than elimination. The half-lives after s.c. administration averaged 3 hours, whereas after i.v. administration, the half-lives were <1 hour. Metabolism of the ISIS 2302 after s.c. injection was consistent with exonucleolytic cleavage, as previously observed after i.v. administration. In summary, s.c. administration of PS-ODN resulted in prolonged and extensive absorption of the ODN.     

In vitro and in vivo assessment of plutonium speciation and decorporation in blood and target retention tissues after a systemic contamination followed by an early treatment with DTPA

This study identifies the main sources of systemic plutonium decorporated in the rat after DTPA i.v. at the dose recommended for humans (30 mumol kg(-1)). For this purpose, standard biokinetic approaches are combined to plasma ultrafiltration for separation of plutonium complexes according to their molecular weight. In vitro studies show that at the recommended DTPA dose, less than 5% of the plasma plutonium of contaminated rats can be displaced from high-molecular-weight ligands. After i.v. administration of Pu-DTPA, early ultrafiltrability of plutonium in plasma decreases with total DTPA dose, which is associated with an increase in plutonium bone retention. This demonstrates the instability of Pu-DTPA complexes, injected in vivo, below the minimal Ca-DTPA dose of 30 mumol kg(-1). Plutonium biokinetics is compared in rats contaminated by plutonium-citrate i.v. and treated or not with DTPA after 1 h. No significant decrease in plasma plutonium is observed for the first hour after treatment, and the fraction of low-molecular-weight plutonium in plasma is nearly constant [5.4% compared with 90% in Pu-DTPA i.v. (30 mumol kg(-1)) and 0.7% in controls]. Thus plutonium decorporation by DTPA is a slow process that mainly involves retention compartments other than the blood. Plutonium-ligand complexes formed during plutonium deposition in the retention organs appear to be the main source of decorporated plutonium.     

Influence of Aggregation and Route of Injection on the Biodistribution of Mouse Serum Albumin

Protein aggregates are a major risk factor for immunogenicity. Until now most studies on aggregate-driven immunogenicity have focused on linking physicochemical features of the aggregates to the formation of anti-drug antibodies. Lacking is however, basic knowledge on the effect of aggregation on the biodistribution and clearance of therapeutic proteins in vivo. The aim of current study was to get insight into the effect of aggregation on biodistribution in mice using different routes of administration. Fluorescently labeled stressed and unstressed mouse serum albumin was injected via different routes in mice and detected via in vivo fluorescence imaging up to 48 hrs post-injection. We found that biodistribution of stressed MSA significantly differed from its unstressed counterpart. Subcutaneous and intramuscular administration resulted in accumulation of protein at the site of injection, from which clearance of stressed MSA was considerably slower than clearance of unstressed MSA. Upon intravenous and intraperitoneal injection of stressed MSA, fluorescent “hotspots” were observed in the spleens, livers and lungs. Further and more detailed examination of biodistribution after intraperitoneal injection showed higher fluorescence in most of tested organs suggesting more efficient diffusion and/or lymphatic uptake from peritoneum of unstressed MSA than the stressed formulation.     

Flare-up of delayed-type hypersensitivity initially induced by murine cloned helper T cells

Delayed-type hypersensitivity (DTH) reactions were induced in mice by cloned helper T cells directed against methylated bovine serum albumin (mBSA). The DTH reactions were induced either by local injection of the helper T cells together with the antigen in the hind feet or by intravenous (iv) administration of the cloned T cells and local injection of the antigen. Local or systemic (oral or iv) administration of mBSA after waning of the DTH induced by the cloned helper T cells caused a flare-up reaction. This indicates that functional helper T cells persist at the inflammation site. The inflammations were quantified in a foot swelling assay and were examined histologically. The inflammation measured in the flare-up reaction was generally lower than in the acute reaction. Histologically the acute inflammation showed edema and a large proportion of granulocytes, whereas the flare-up reaction appeared more histiocytic and showed less edema.     

The effect of X rays, DTPA, and aspirin on the absorption of plutonium from the gastrointestinal tract of rats

To measure the effect of radiation on plutonium transport, rats that were exposed to 250-kVp X rays were given 238Pu 3 days afterwards by either gavage or injection into a ligated segment of the duodenum. In a second group of experiments, rats were either injected intraduodenally with 238Pu-DTPA or administered the chelate intravenously and the 238Pu by gavage. In a third experiment, rats that had been gavaged with 200 or 400 mg/kg/day of aspirin for 2 days were injected intragastrically with 238Pu nitrate. Results of the first experiment showed a dose-dependent increase in 238Pu absorption between 800 and 1500 rad of lower-body X irradiation. Intravenous or intraduodenal injections of DTPA caused a marked increase in 238Pu absorption but resulted in decreased plutonium deposition in the skeleton and liver. Retention of 238Pu in the skeleton of rats given aspirin was double that of controls, but the effect on plutonium absorption was less marked than that of DTPA.     

Studies on teratological testing using chicken embryos--effects of solvents, injection sites and the age of the embryo.

The purpose of this study was to examine the effects of solvents, injection sites and embryo age when using chicken embryos for teratological testing. The results obtained were as follows: 1) Solvents: distilled water, physiological saline, sesame oil, 25% ethanol, 0.5% carboxymethylcellulose and 0.1% methylcellulose solution were not toxic in Day-4 embryos (eggs incubated for 4 days). 2) With 6-aminonicotinamide, air space injection more effectively induced malformations in chicken embryos. With boric acid, however, yolk sac injection was better. It was shown therefore that the appropriate injection site varied according to the test drug. 3) 6-aminonicotinamide induced characteristic malformations when injected into embryos of various ages ranging from 4 to 13 days of incubation. On the other hand, boric acid was teratogenetic only when injected into Day-3 or Day-4 embryos. It seems, therefore, that the age of the embryo at the time of administration is of critical importance and that the optimum time of administration varies according to the test drug.     

Therapeutic effect of CpG motifs on the development of chronic graft-versus-host disease in mice

Transferring DBA/2 spleen cells into (C57BL/10xDBA/2) F1 (referred to as BDF1) mice induces a chronic graft-versus-host disease (GVHD), characterized by the production of Th(2) cytokines, hypergammaglobulinemia, and immune complex-mediated glomerulonephritis that resembles systemic lupus erythematosus. DNA motif consisting of an unmethylated CpG dinucleotide flanked by two 5' purines and two 3' pyrimidines (CpG ODN) induces Th(1) cytokine production in mice. This study examines the effect of administering CpG ODN to mice undergoing chronic GVHD, based on the premise that altering Th(1)/Th(2) activity might beneficially impact on disease progression.GVHD BDF1 mice injected with DBA/2 spleen cells were treated with weekly intraperitoneal injection of 50 microg CpG ODN. This treatment significantly suppressed the production of IgG anti-DNA autoantibody and reduced the development of glomerulonephritis. Serum IgG2a titers were higher in the CpG ODN than in non-CpG control group, whereas IgG1 titers were unchanged. As predicted, IFN-gamma levels were significantly higher in the CpG ODN-treated group, while IL-4 levels were lower, resulting in a shift in the Th(1)/Th(2) cytokine ratio. Results suggest that CpG ODN administration may be of therapeutic benefit in chronic GVHD.     

Intratesticular injection as a method to assess the potential toxicity of various agents and to study mechanisms of normal spermatogenesis

To better understand, to optimize, and to validate the technique of intratesticular (i.t.) injection, several parameters related to i.t. injection were examined. Volumes exceeding 50 μl could be injected i.t.; however, testes frequently became excessively turgid and backflow of injected fluids occurred. Thus, a volume of 50 μl or less was deemed optimal for injection. To determine the rate of distribution of substances throughout the testis, trypan blue was injected i.t. near the caudal pole of the testis, and the movement of dye was monitored. Within 2 min, the dye had spread approximately 1 cm from the site of injection, and in 5 min it had spread twice that distance. In 2 h, the dye had become distributed throughout the testis except at its extreme cranial pole. Seminiferous tubules did not take up dye, indicating that the spread of dye was via peritubular lymphatics. Seminiferous tubule histology appeared virtually unaffected by i.t. injection, even at regions adjacent to the site of injection, when a sterile 26-gauge or smaller bore needle was utilized. To determine disappearance from the testis, radiolabeled inulin was injected i.t. Half time for absorption was achieved at 1.75 h. Potential vehicles were expolored in which compounds with a variety of physical properties could be injected. Gum tragacanth, normal saline, ethylene glycol, dimethyl sulfoxide (DMSO) mixed 1:1 with normal saline, sesame oil, and propylene glycol were found to be suitable injection vehicles, whereas ethanol, dissolved in normal saline in concentrations as low as 0.5% was found unsuitable. To assess vehicle efficiency, various vehicles were utilized with a known testicular toxin (taxol) and injected into one testis, and the histology was compared with the contralateral testis injected with vehicle alone. All vehicles, found suitable above, allowed dispersion of taxol to influence areas distant from the site of injection. Intratesticular injection assesses the potential of agents to directly affect the testis, and systemic metabolism is avoided. Their rapid spread throughout the lymphatics of the testes allows seminiferous tubules to be exposed to agents in innocuous vehicles more rapidly and in higher concentration than is often possible when using systemic injections.     

Direct and reverse transport of RNA in a system of isolated HeLa cell nuclei

In a system containing isolated HeLa cell nuclei the release of RNA from the nuclei may be paralleled with the antagonistic process, i. e., RNA translocation into the nuclei. The RNA release from the nuclei depends on incubation time, pH, Mg2+ and nucleoside triphosphate concentration. The rate of reverse transport depends on pH, size of RNA to be translocated and the physiological state of the nuclear membrane. Low molecular weight RNAs (less than 10 S) are translocated into the nuclei most effectively. The nuclei of synchronized HeLa cells in the G1-period are more "permeable" for translocated RNA as compared with the S-phase HeLa cell nuclei.     

A possible correlation between histological changes in regional subcutaneous tissue induced by bacterial lipopolysaccharides and their adjuvant activities

Previously it was demonstrated that Klebsiella pneumoniae O3 lipopolysaccharide (KO3 LPS) exhibited much stronger adjuvant action on antibody response to subcutaneously (s.c.) injected sheep red blood cells or deaggregated bovine serum albumin than did other kinds of LPS, the R-form LPS lacking the O-specific polysaccharide chain of KO3 LPS (R-LPS), and the lipid A fractionated from KO3 LPS. We compared histological changes in the regional subcutaneous tissues of mice injected subcutaneously (s.c.) with KO3 LPS, the lipid A, and R-LPS. At the early stage after injection, KO3 LPS induced the infiltration of a large number of inflammatory cells, mainly polymorphonuclear leukocytes (PMN), at the site of injection. Neither R-LPS nor the lipid A induced the accumulation of PMN so much as KO3 LPS did. When injected s.c. with LPS from Escherichia coli O111 (EO111 LPS) and O55 (EO55 LPS), and Salmonella enteritidis (Sent LPS), the appearance of PMN at the regional site was much less than KO3 LPS. KO3 LPS could accumulate more 51Cr-labeled leukocytes at the injection site than EO111 LPS and Sent LPS. Administration of acetylsalicylic acid, which can inhibit leukocyte migration in inflammatory lesions, suppressed its adjuvant action. It was therefore suggested that the strong adjuvant action of KO3 LPS in s.c. injection might be dependent on its potent capability of accumulating PMN at the regional subcutaneous tissue. Furthermore, at the late stage after injection, the formation of several lymphoid follicles at the regional site was seen only in mice injected with KO3 LPS. It might be also related to the strong adjuvant action of KO3 LPS.     

The transfer and characterization of resistance to common root rot from Thinopyrum ponticum to wheat.

Common root rot, caused by Cochliobolus sativus (Ito and Kurib) Drechs. ex Dastur, is a major soil-borne disease of spring and winter wheat (Triticum aestivum L. em Thell.) on the Canadian prairies. Resistance to common root rot from Thinopyrum ponticum (Podp.) Liu and Wang was transferred into wheat via crossing with Agrotana, a resistant wheat - Th. ponticum partial amphiploid line. Evaluation of common root rot reactions showed that selected advanced lines with blue kernel color derived from a wheat x Agrotana cross expressed more resistance than the susceptible T. aestivum 'Chinese Spring' parent and other susceptible wheat check cultivars. Cytological examination revealed 41 to 44 chromosomes in the advanced lines. Genomic in situ hybridization, using total genomic DNA from Pseudoroegneria strigosa (M. Bieb) A. L?ve (St genome) as a probe, demonstrated that the blue kernel plants had two pairs of spontaneously translocated J-Js and Js-J chromosomes derived from the J and Js genome of Th. ponticum. The presence of these translocated chromosomes was associated with increased resistance of wheat to common root rot. The lines with blue aleurone color always had a subcentromeric Js-J translocated chromosome. The subtelocentric J-Js translocated chromosome was not responsible for the blue kernel color. The genomic in situ hybridization analysis on meiosis revealed that the two spontaneous translocations were not reciprocal translocations.     

Enhancement of suppressor T cell activity by injection of anti-IFN-gamma monoclonal antibody

In the present study, the contribution of IFN-gamma to the generation of helper activity in mice was investigated by use of anti-mouse IFN-gamma rat mAB (AN 18.17.24). This mAb was alum precipitated and injected i.p. before or after carrier priming. Results show that spleen cell helper activity is markedly inhibited by anti-IFN-gamma mAb injection. This inhibition is time and dose dependent, and counteracted by IFN-gamma administration. Thus, the anti-IFN-gamma mAb appears to inhibit helper cell activity by neutralization of the IFN-gamma required for the antibody response. Moreover, AN 18.17.24 mAb injection results in increased activation of Lyt-2+ T cells which markedly suppress Th activity. These findings altogether indicate that besides the activation of macrophages and Th, IFN-gamma seems to exert a negative interference in suppressor T lymphocyte circuits and, as a consequence, to inhibit immunosuppression.     

Uptake dynamics and retinal tolerance of phosphorothioate oligonucleotide and its direct delivery into the site of choroidal neovascularization through subretinal administration in the rat

This study aimed to investigate uptake dynamics and retinal tolerance of phosphorothioate oligonucleotides (PS-oligos) following subretinal injection. A fluorescent-labeled PS-oligo (FL-oligo) with random sequence was administered into the subretinal space of rat by transsclera-choroid-retinal pigment epithelium (RPE) injection at doses of 0.129, 1.29, and 12.9 microg in 2.0 microl solution. The uptake dynamics were evaluated by fundus fluorescent photography in real time and by fluorescence microscopy using flat mounts and cryosections. Immunophenotyping for CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages was performed to assess cellular infiltration in the retina. In addition, the FL-oligo was injected subretinally in a rat model of choroidal neovascularization (CNV) for direct delivery into the site of CNV. Subretinal administration of FL-oligo resulted in both dose-dependent and time-dependent distribution in the retina, where it accessed the RPE and all layers of the neuroretina. CD4+, CD8+ cytotoxic lymphocytes, and CD68+ macrophages were observed at the site of needle penetration. However, in areas far from the injection site where the FL-oligo appeared strongly, cellular infiltration was absent, and the retinal morphology was preserved very well. The FL-oligo was successfully delivered into the site of intense laser photocoagulation. It was predominantly localized to the RPE, macrophages, and some choroid cells and remained detectable for at least 56 days after injection. Our results demonstrate for the first time that subretinal injection efficiently introduced PS-oligo into the RPE and neuroretina with an acceptable level of safety. Subretinal administration of antiangiogenic oligonucleotides may hold great potential for the treatment of CNV.     

Role of S-adenosyl-L-methionine in potentiating cadmium mobilization by diethylenetriamine penta acetic acid in mice

The beneficial effects of S-adenosyl-L-methionine (SAM) in potentiating the mobilization of cadmium by cadmium trisodium diethylenetriamine penta acetic acid (DTPA) from the major target organs and restoration of depleted tissue glutathione (GSH), zinc and copper concentration, were determined in cadmium-exposed mice. The results indicated a significant depletion of cadmium concentration from the blood in DTPA plus SAM treated animals compared with DTPA or SAM alone treated groups. The treatment with SAM alone was also effective in correcting the zinc and GSH concentrations. The results indicated few beneficial effects of concomitant SAM administration during chelation of cadmium with DTPA.