Probing Early Tumor Response to Radiation Therapy Using Hyperpolarized [1-13C]pyruvate in MDA-MB-231 Xenografts

Following radiation therapy (RT), tumor morphology may remain unchanged for days and sometimes weeks, rendering anatomical imaging methods inadequate for early detection of therapeutic response. Changes in the hyperpolarized [1-¹³C]lactate signals observed in vivo following injection of pre-polarized [1-¹³C]pyruvate has recently been shown to be a marker for tumor progression or early treatment response. In this study, the feasibility of using ¹³C metabolic imaging with [1-¹³C]pyruvate to detect early radiation treatment response in a breast cancer xenograft model was demonstrated in vivo and in vitro. Significant decreases in hyperpolarized [1-¹³C]lactate relative to [1-¹³C]pyruvate were observed in MDA-MB-231 tumors 96 hrs following a single dose of ionizing radiation. Histopathologic data from the treated tumors showed higher cellular apoptosis and senescence; and changes in the expression of membrane monocarboxylate transporters and lactate dehydrogenase B were also observed. Hyperpolarized ¹³C metabolic imaging may be a promising new tool to develop novel and adaptive therapeutic regimens for patients undergoing RT.     

Preventive Psychiatry: The Psychiatric Team as Consultant to the Public Health Nurse

Various forms of collaboration between the disciplines of public health and psychiatry are briefly reviewed and the 25-year-old mental health program of the Vancouver Health Department is described. The public health nurse has prime responsibility in all children with emotional disorders. She is supported by a psychiatric team which provides active treatment and educational and consultative help for the nurse and the school. During the year 1963, six social workers had 2357 contacts with nurses and school personnel but only 1049 treatment interviews. Of 401 children referred to the psychiatric team, 138 received active clinic treatment, 141 remained under supervision by the public health nurse, and 122 were referred elsewhere. In addition, 1330 children were identified as “mental hygiene cases” in the caseload of the 170 public health nurses in the community. By close co-ordination, the public health nurse and the psychiatric team can enhance each other''s contributions to community mental health.     

Involvement of endorphins in emotional hyperthermia of rats

When rats were confronted with the novel experience of a new environment and stressful handling procedure their body temperature increased within minutes. At the same time β-endorphin-like immunoreactivity in the plasma increased dramatically. The stress-induced hyperthermia could be antagonized or reversed by the active, not however, by the inactive enantiomer of naloxone. The data provide evidence for a physiological role of endorphins.     

Studies on adenosine 3′,5′-phosphate-binding and adenosine 3′,5′-phosphate-dependent protein kinase activities associated with subcellular fractions of Chinese hamster ovary cells

Both cyclic AMP-binding and cyclic AMP-dependent protein kinase activities exists in Chinese hamster ovary cell extract. Competition experiments demonstrate that the binding is specific for cyclic AMP. All cellular elements including nucleus, mitochondria, plasma membrane, microsome, ribosome and cytosol contain both activities. Binding activity is highest in the cytosol and lowest in the nucleus. Each fraction contains endogenous protein kinase activity which is insensitive to cyclic AMP activation. When histone was used as a substrate, protein kinase activity in all fractions was stimulated by cyclic AMP (with the highest in cytosol and lowest in the nucleus) and inhibited by Walsh's protein kinase inhibitor.