No abstract

Nanoparticle radiosensitization has been well demonstrated to enhance effects of radiotherapy, motivated to improve therapeutic ratios and decrease morbidity in cancer treatment. A significant challenge exists in optimizing formulations and translation due to insufficient knowledge of the associated mechanisms which have historically been limited to physical concepts. Here we investigated a concept for the role of biological mechanisms. The mere presence of gold nanoparticles led to a down regulation of thymidylate synthase, important for DNA damage repair in the radioresistant S phase cells. By developing a cross-correlative methodology to reveal probabilistic gold nanoparticle uptake by cell sub-populations and the associated sensitization as a function of the uptake, a number of revealing observations have been achieved. Surprisingly, for low numbers of nanoparticles a desensitization action was observed. Sensitization was discovered to preferentially impact S phase cells where impairment of the DNA damage response by the homologous recombination pathway dominates. This small but radioresistant cell population correlates with much greater proliferative ability. Thus a paradigm is presented whereby enhanced DNA damage is not necessarily due to an increase in the number of DNA Double Strand Breaks (DSBs) created, but can be from a nanoparticle-induced impairment of the damage response by down regulating repair proteins such as thymidylate synthase.

Body-fat gain during pregnancy (weight--total body water/0.73) was measured in 50 rural Gambian women exposed to seasonal energy demands of subsistence farming and to annual preharvest food shortages. Twenty-eight women received dietary supplements in amounts previously shown to increase birth weight. In unsupplemented women, fat gain was profoundly affected by the seasons through which the pregnancy progressed, ranging from an estimated loss of 4.7 kg to a net gain of 3 kg at various times of the year. Adjustment for season revealed, however, that pregnancy per se was without effect on body fat content. Supplementation increased fat gain during pregnancy by approximately 2 kg (p less than 0.05) and gave protection against the worst effects of season on energy balance. These findings contribute to our understanding of the consequences of low food intake during pregnancy and the effects of dietary supplementation on birth weight.

Bronchiolitic infants presenting with a detectable respiratory virus during hospitalization demonstrated elevated markers of airway tissue inflammation and injury. In this cohort, viral etiology did not discernibly modulate chemokine-mediated neutrophil infiltration and activation. Pediatr Pulmonol. 2017;52:238-246. © 2016 Wiley Periodicals, Inc.

Seven different synthetic peptides were prepared corresponding to regions of the beta A subunit of 32 KDa human ovarian inhibin predicted to contain possible continuous B cell epitopes. These were coupled to tuberculin as a carrier and used to immunize mice previously given a priming dose of human tuberculosis vaccine. Only one of these peptides, corresponding to sequence 82-114, consistently gave good titres of antibodies reactive with intact 32 KDa bovine inhibin by ELISA. From one of the mice immunized with this peptide, six stable hybridomas were prepared. Five of these secreted an IgM and the sixth (clone E4) secreted an IgG2b antibody. Immunoblotting experiments on follicular fluid concentrates, after treatment with sodium dodecyl sulphate and mercaptoethanol, showed strong reactivity of the antibody from clone E4 only with bands of about 13 kDa and 58 kDa corresponding to forms of the beta A subunit previously described. This monoclonal antibody, and an antibody to the alpha subunit previously made in this laboratory using synthetic peptides, should prove useful reagents for further study of inhibins and activins.