No abstract

Recombinant bovine prolactin (rbPRL) or bovine growth hormone (rbGH) was administered to mature female rats (10/treatment group) by daily subcutaneous injection for 10 days. Doses ranged from 7 to 5,000 micrograms/day (0.03-24 mg/kg body wt). Both rbPRL and rbGH increased body weight gain and food intake, but these parameters were increased at lower doses of rbPRL (7-63 micrograms/day) than rbGH (> 190 micrograms/day). Weight gain and food intake were maximally stimulated by 190 micrograms/day rbPRL, whereas maximal increased weight gain was obtained with the highest dose of rbGH (5,000 micrograms/day). Total carcass protein was increased by both hormones; however, protein as a percentage of body weight was unchanged. Similarly, neither rbPRL nor rbGH changed the percentage of carcass moisture. Percentage of body fat was increased by rbPRL but was decreased by rbGH. Weight of the gastrointestinal tract and kidneys was increased by both hormones, but increases were in proportion to body weight gain. These data confirm that ungulate prolactin is a hyperphagic agent in the female rat. In addition, they suggest that, while prolactin stimulates growth in mature female rats, this growth is probably not via a somatogenic mechanism.

Volatile organic compounds in mouth air and saliva are useful in diagnosis of several systemic pathologies. Specific oral metabolites (ammonia, urea, volatile sulphur compounds) have been suggested as possible diagnostic and contributory factors to the etiology or pathogenesis of periodontitis. In this study, volatile organic compounds are characterized by gas chromatography/mass spectrometry from the headspace of incubated whole saliva from subjects with essentially normal oral health and subjects with moderate to severe periodontitis as rated by four oral health indices. Several compounds including aliphatic and aromatic alcohols, indole and dimethyl dLsulfide appear common to all subjects. Moreover, aromatic nitrogen containing compounds, i.e., pyridine and picolines, appear only in subjects with moderate to severe periodontitis. The occurrence of pyridine and picolines in the salivary volatiles of diseased subjects suggests that they are related to the disease process.

Paclitaxel-loaded shell cross-linked polymeric nanoparticles having an enzymatically and hydrolytically degradable poly(lactic acid) core and a glutathione-responsive disulfide cross-linked poly(oligoethylene glycol)-containing corona were constructed in aqueous solution and investigated for their stimuli-responsive release of the embedded therapeutics and in vitro cytotoxicity. Paclitaxel release from the nanoparticles in PBS buffer was accelerated in the presence of glutathione at both pH 5.5 and pH 7.4, reaching ca. 65% cumulative drug release after 8 d, whereas only ca. 50% and 35% extents of release were observed in the absence of glutathione at pH 5.5 and pH 7.4, respectively. Enzyme-catalyzed hydrolysis of the nanoparticle core resulted in the degradation of ca. 30% of the poly(lactic acid) core to lactic acid within 12 h, with coincidently triggered paclitaxel release of ca. 37%, as opposed to only ca. 17% release from the uncatalyzed nanoparticles at pH 7.4. While empty nanoparticles did not show any inherent cytotoxicity at the highest tested concentrations, paclitaxel-loaded nanoparticles showed IC50 values that were similar to those of free paclitaxel at 72 h incubation with KB cells and were more efficacious at ca. 3-fold lower IC50 value (0.031 μM vs 0.085 μM) at 2 h of incubation. Against human ovarian adenocarcinoma cells, the paclitaxel-loaded nanoparticles exhibited a remarkable ca. 11-fold lower IC50 than a Taxol-mimicking formulation (0.0007 μM vs 0.008 μM) at 72 h of incubation. These tunable dual-responsive degradable nanoparticles show great promise for delivery of paclitaxel to tumor tissues, given their superior in vitro efficacies compared to that of free paclitaxel and Taxol-mimicking formulations.