Influence of multiple models on the behavior of institutionalized retarded children: increased generalization to other models and other behaviors

After being pretested to determine base levels of imitation, 32 9-14 yr old retarded children were reinforced for imitating a model in 9 training sessions. Ss in a single model condition were reinforced by the same model across all sessions, whereas Ss in a multiple model condition were reinforced by 3 different models (3 sessions per model). A posttest to assess levels of imitation was then conducted by a model with whom the Ss had not had contact and who demonstrated a new set of behaviors. Results during training sessions show that (a) Ss learned to imitate, and this learning was not inhibited by multiple models; and (b) Ss generalized and imitated nonreinforced behaviors, and this response generalization was facilitated by multiple models. Most importantly, pre-posttest comparisons indicated that generalized use of the new response class (imitation) with new models was 8 times greater for Ss trained with multiple as opposed to single models. Implications for the maintenance and generalized effectiveness of social intervention programs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New and versatile ternary ligand system for technetium radiopharmaceuticals: water soluble phosphines and tricine as coligands in labeling a hydrazinonicotinamide-modified cyclic glycoprotein IIb/IIIa receptor antagonist with 99mTc

A hydrazinonicotinamide-functionalized cyclic platelet glycoprotein IIb/IIIa (GPIIb/IIIa) receptor antagonist [cyclo(D-Val-NMeArg-Gly-Asp-Mamb(5-(6-(6-hydrazinonicotin amido) hexanamide))) (HYNIC-tide)] was labeled with 99mTc using tricine and a water soluble phosphine (TPPTS, trisodium triphenylphosphine-3,3',3"-trisulfonate; TPPDS, disodium triphenylphosphine-3,3'-disulfonate; or TPPMS, sodium triphenylphosphine-3-monosulfonate] as coligands. The synthesis of technetium complexes, [99mTc(HYNICtide)(L)(tricine)] (1, L = TPPTS; 2, L = TPPDS; 3, L = TPPMS), can be performed in one or two steps in high yield and with high specific activity (> or = 20,000 Ci/mmol). For example, the reaction of the HYNICtide, [99mTc]pertechnetate, stannous chloride, and tricine at pH 4-5 and room temperature results in the complex [99mTc(HYNICtide)(tricine)2], which reacts with TPPTS (50 degrees C for 30 min) to give complex 1 in > or = 90% yield as determined by radio-HPLC. Complexes 1-3 are formed as equal mixtures of two isomeric forms and are stable for > or = 6 h in the reaction mixture and in dilute solution. Both isomeric forms of complex 1 were found by a platelet-binding assay to contain the 99mTc-labeled HYNICtide and possess biological activity. The composition of these complexes was determined to be 1:1:1:1 for Tc:HYNICtide:L:tricine through a series of mixed ligand experiments on the tracer (99mTc) level. Surprisingly, this composition is maintained over a wide range of relative ligand ratios. The relative bonding capability of the three phosphine coligands to the Tc was determined by spiking various amounts of TPPDS or TPPMS into TPPTS and falls in the order TPPMS > TPPDS > TPPTS. The lipophilicity of the [99m Tc]HYNICtide complexes can be systematically varied by the choice of the phosphine and aminocarboxylate coligands. Using the combination of tricine and a phosphine ligand, HYNIC-derivatized peptides or other small molecules can be labeled with 99mTc in high specific activity and with high stability for potential use as radiopharmaceuticals.     

The use of in bowel urology. Metabolic and nutritional complications

Metabolic and nutritional complications of urinary diversion through bowel or stomach segments are common, but fortunately, not often severe. When metabolic abnormalities are problematic, deterioration or baseline insufficiency in renal function is the most likely cause. Deterioration is most commonly associated with obstruction or infection. The urologist should be acutely aware of the potential for metabolic derangements when the prediversion creatinine is greater than 2.0 mg/dL. In this situation, the urologist should employ the basic principles in this article when planning the procedure in order to minimize metabolic complications and morbidities. In the setting of significant renal insufficiency, a short colon or ileal conduit would likely be superior to an ileal or colonic neobladder, or a diversion, incorporating a large gastric segment. Furthermore, in the absence of symptomatic metabolic abnormalities, we advocate treatment of minor laboratory abnormalities, particularly acidosis, to reduce the incidence of metabolic bone disease. Nutritional and gastrointestinal complications are treated on an "as needed" basis, with the exception of metabolic bone disease, which we would hope to prevent with alkalinization and Vitamin C supplementation. Some of the nutritional and gastrointestinal complications are best avoided by leaving the ileocecal valve intact, or by minimizing the use of certain segments. Some evidence exists that over time, histologic changes in the epithelium of diversion segments may impair absorption and contribute to greater resistance against metabolic derangements. Whether the changes truly reduce the incidence of metabolic abnormalities remains to be studied. The ideal, complication-free, diversion with universal application does not exist; however, the urologist must strive to select an option that will provide a functional result for the patient with minimal associated morbidity.     

Stenting of a renal artery bifurcation stenosis

Gene therapy, in particular the transfer of genes encoding immunostimulatory molecules (cytokines and costimulatory molecules) as well as selectively cytotoxic enzymes and DNA vaccination, has the potential of enhancing cell mediated immune responses against tumours including those of colorectal origin. Genes can be transferred using viral vectors either to cultured tumour cells in vitro that can be returned to the patient as a "cancer vaccine", or directly to tumour cells in vivo. Vaccination with DNA constructs expressing specific tumour antigens characteristic of colorectal neoplasia can trigger immune recognition and destruction of tumour cells. The aim is to tip the balance from protumour to antitumour mechanisms by generating a local immune response and systemic antitumour immune memory to destroy metastases. Studies in murine models, combined with human studies, show that such approaches could become an adjunct to current treatments for human colorectal cancer in the near future.     

Effect of ADP on binding of skeletal S1 to F-actin

The proximity of skeletal myosin subfragment-1 (S1) to actin, and its orientation with respect to thin filaments of single muscle fibers, were compared in the presence and in the absence of ADP. The proximity was assessed by the efficiency of carbodiimide-induced cross-linking and the orientation by polarization of fluorescence of probes attached to the essential light chains. ADP made no difference in proximity or orientation when the molar ratio of S1 to actin was low or high. However, at the intermediate ratios, ADP made a significant difference. Strong dissociating agents, AMP-PNP and PPi, made significant differences at all ratios. To explain this behavior, it is unnecessary to invoke the ADP-induced "swinging" of the tail of S1. Rather, it is simply explained by the "two-state" model which we proposed earlier, in which S1 binds to one or to two actin protomers, depending on the saturation of the filaments with S1s. The dissociation induced by the ADP shifts the equilibrium between the two bound states. At high and low degrees of saturation, ADP is unable to significantly decrease the amount of S1 bound to F-actin. However, at intermediate saturation levels, ADP causes significantly more S1s to bind to two actins. These results suggest that the ADP-induced changes seen at the intermediate molar ratios are due to the dissociation-induced reorientation of S1.     

Integrated measurements of short-lived 222Rn progeny by rotating filters

The dependence of the risk from inhalation of radon progeny on their disequilibrium suggests that the measurements of the time-integrated concentrations of each of the short-lived radon progeny are necessary for complete risk estimations. This paper presents a method that, in principle, allows the determination of the integrated specific volume activities in air of each of the radionuclides 218Po, 214Pb, 214Bi, 212Pb, and 212Bi. The method employs thermoluminescence detectors positioned around uniformly rotating filters. Two prototypes that are suitable for practical applications are described and mathematical expressions for data processing are given. Experiments with these "rotating filter dosimeters" were conducted in atmospheres radiologically dominated by 222Rn progeny. The comparison between the results obtained by the proposed method and those given by simultaneously conducted series of instantaneous grab-sampling measurements support the conclusion that the method works for 222Rn progeny. The method can be experimentally extended for 220Rn progeny as well as for unattached fractions.     

Maternal and neonatal plasma inorganic fluoride levels after methoxyflurane analgesia for labor and delivery

At the time of the experiment, lean animals weighed 226-235 gm and the fatty rats 330-440 gm. On Day 5 after castration, rats received injections of estradiol-17beta (E2) for a 3-day period. Doses were .01-100 mcg/100 gm of body weight. Radioiodine uptake was determined by injecting 50 microCi of iodine-125 ip 24 hours before sacrifice. Beginning 12 hours after the last dose of E2, pairs of rats including a fatty and lean rat were sacrificed until all had been killed. Ovaries (at castration or autopsy), pituitary, and thyroid were removed and weighed. Uteri in obese rats were significantly smaller than in lean rats. There was a close dose-response relationship between E2 and the weight of the uteri; this was more marked in the obese rats. The radioactivity of the thyroid was increased more in the lean rats. Fatty rats ate more food than lean rats. The highest dose of E2 did not increase the food intake of obese rats but did increase that of the lean animals. It is concluded that the small uteri in the fatty rats may be due to decreased estrogenization and that this may also partly account for the small pituitary and low thyroid uptake of radioiodine.