Hemoglobin solutions coupled with polyethylene glycol 1900: preparation, purification, quality control and pharmacological trials by hemorrhagic shock

The usefulness of hemoglobin solutions as oxygen transporters is limited by their high affinity for oxygen and rapid elimination from the circulation. Various chemical modifications of hemoglobin aimed at overcoming these two handicaps have been suggested. We have developed a conjugate of pyridoxylated human hemoglobin with monomethoxypolyoxyethtylene 1900, whose preparation and properties are described. We present comparative results on short-term or definitive survival of Wistar rats which, during hemorrhagic shock due to the loss of 60 or 80% of their blood mass, were given a solution of native or modified hemoglobin, in some cases purified by ion-exchange chromatography to remove non-heme proteins, lipids, and some endotoxins. The more complex the treatment used to improve the properties and the purity of the hemoglobin solutions, the longer the animals survived. The loss of hemoglobin in the urine was greatly reduced after conjugation: after 20 h, less than 6% of the total infused.     

Ranking institutional settings based on publications in community psychology journals

Two primary outlets for community psychology research, the American Journal of Community Psychology and the Journal of Community Psychology, were assessed to rank institutions based on publication frequency and scientific influence of publications over a 32‐year period. Three specific periods were assessed (1973–1983, 1984–1994, 1995–2004). Findings indicate that there were a large group of institutions that published articles during these periods. Those academic institutions that had the most published articles as well as the largest influence, based on citations by other authors, were identified. Using archival data from the community psychology literature represents one approach for identifying those settings that made substantial contributions to the development and growth of the field. © 2007 Wiley Periodicals, Inc. J Comm Psychol 35: 967–979, 2007.     

The role of bicarbonate in regulatory volume decrease (RVD) in the epithelial-derived human breast cancer cell line ZR-75-1

This study investigates the mechanisms involved in the regulatory volume decrease (RVD) in ZR-75-1 epithelial-derived human breast cancer cells. Cell volume changes were measured during osmotic shock using video imaging. In HEPES-buffered hypotonic solutions no RVD was observed; however, RVD was observed in HCO(3)(-)-buffered hypotonic solutions. Inhibition of RVD by 10 microM tamoxifen and 100 microM DIDS (inhibitors of volume-regulated anion channels; VRAC) and 2 mM TEA(+) (inhibitor of K(+) channels) indicates a role for these channels. In HCO(3)(-)-buffered Cl(-)-free solutions RVD was partially abolished indicating that HCO(3)(-) efflux can support RVD but also may have another role. Further experiments investigated whether HCO(3)(-) assists in the accumulation of Cl(-) via Cl(-)-HCO(3)(-) exchange. Regulatory volume increase (RVI) was also HCO(3)(-)-dependent and was inhibited by 500 microM DIDS and 10 microM 5-( N, N-dimethyl)-amiloride (DMA) indicating a role for coupled Cl(-)-HCO(3)(-) and Na(+)-H(+) exchange. Finally, in the presence of 10 microM DMA, RVD was partially inhibited providing further evidence for a role of Cl(-)-HCO(3)(-) exchange. Thus RVD in ZR-75-1 cells involves the activation of VRAC and K(+) channels. RVD is HCO(3)(-)-dependent and HCO(3)(-) efflux through VRAC appears to contribute directly to RVD. HCO(3)(-), however, also has another role in facilitating Cl(-) accumulation via Cl(-)-HCO(3)(-) exchange.     

Modulation of level response areas and stimulus selectivity of neurons in cat primary auditory cortex

Sounds commonly occur in sequences, such as in speech. It is therefore important to understand how the occurrence of one sound affects the response to a subsequent sound. We approached this question by determining how a conditioning stimulus alters the response areas of single neurons in the primary auditory cortex (AI) of barbiturate-anesthetized cats. The response areas consisted of responses to stimuli that varied in level at the two ears and delivered at the characteristic frequency of each cell. A binaural conditioning stimulus was then presented > or =50 ms before each of the stimuli comprising the level response area. An effective preceding stimulus alters the shape and severely reduces the size and response magnitude of the level response area. This ability of the preceding stimulus depends on its proximity in the level domain to the level response area, not on its absolute level or on the size of the response it evokes. Preceding stimuli evoke a nonlinear inhibition across the level response area that results in an increased selectivity of a cortical neuron for its preferred binaural stimuli. The selectivity of AI neurons during the processing of a stream of acoustic stimuli is likely to be restricted to a portion of their level response areas apparent in the tone-alone condition. Thus rather than being static, level response areas are fluid; they can vary greatly in extent, shape and response magnitude. The dynamic modulation of the level response area and level selectivity of AI neurons might be related to several tasks confronting the central auditory system.     

Short-term impact of COVID-19 on quality of life,perceived stress,and serious psychological distress in an adult population in the midwest United States

Quality of Life Research - This study aimed to investigate changes over time in quality of life, perceived stress, and serious psychological distress for individuals diagnosed with COVID-19 in an...