50 research outputs found

    On the interactions of lipids and proteins in the red blood cell membrane

    Get PDF
    The effects of temperature and of the action of a purified phospholipase C enzyme preparation on human red blood cell membranes has been investigated by chemical analyses, circular dichroism, and proton magnetic resonance measurements. The results indicate that a substantial fraction of the phospholipids and the proteins of the membranes can change structure independently of one another, suggesting a mosaic pattern for the organization of the lipids and proteins in membranes

    A Dominant Negative ERβ Splice Variant Determines the Effectiveness of Early or Late Estrogen Therapy after Ovariectomy in Rats

    Get PDF
    The molecular mechanisms for the discrepancy in outcome of initiating estrogen therapy (ET) around peri-menopause or several years after menopause in women are unknown. We hypothesize that the level of expression of a dominant negative estrogen receptor (ER) β variant, ERβ2, may be a key factor determining the effectiveness of ET in post-menopausal women. We tested this hypothesis in ovariectomized nine month-old (an age when irregular estrous cycles occur) female Sprague Dawley rats. Estradiol treatment was initiated either 6 days (Early ET, analogous to 4 months post-menopause in humans), or 180 days (Late ET, analogous to 11 years post-menopause in humans) after ovariectomy. Although ERβ2 expression increased in all OVX rats, neurogenic and neuroprotective responses to estradiol differed in Early and Late ET. Early ET reduced ERβ2 expression in both hippocampus and white blood cells, increased the hippocampal cell proliferation as assessed by Ki-67 expression, and improved mobility in the forced swim test. Late ET resulted in either no or modest effects on these parameters. There was a close correlation between the degree of ERβ2 expression and the preservation of neural effects by ET after OVX in rats, supporting the hypothesis that persistent elevated levels of ERβ2 are a molecular basis for the diminished effectiveness of ET in late post-menopausal women. The correlation between the expression of ERβ2 in circulating white blood cells and brain cells suggests that ERβ2 expression in peripheral blood cells may be an easily accessible marker to predict the effective window for ET in the brain

    Individual, social, and environmental factors affecting salivary and fecal cortisol levels in captive pied tamarins (Saguinus bicolor)

    Get PDF
    This is the peer reviewed version of the following article: Price, E., Coleman, R., Ahsmann, J., Glendewar, G., Hunt, J., Smith, T. & Wormell, D. (2019). Individual, social, and environmental factors affecting salivary and fecal cortisol levels in captive pied tamarins (Saguinus bicolor). American Journal of Primatology, 81(8), which has been published in final form at https://doi.org/10.1002/ajp.23033. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-ArchivingPied tamarins (Saguinus bicolor) are endangered New World primates, and in captivity appear to be very susceptible to stress. We measured cortisol in 214 saliva samples from 36 tamarins and in 227 fecal samples from 27 tamarins, and investigated the effects of age, sex, pregnancy, rearing history, social status, weight, group composition, and enclosure type using generalized linear mixed models. There was no effect of age on either fecal or salivary cortisol levels. Female pied tamarins in late pregnancy had higher fecal cortisol levels than those in early pregnancy, or nonpregnant females, but there was no effect of pregnancy on salivary cortisol. Females had higher salivary cortisol levels than males, but there was no effect of rearing history. However, for fecal cortisol, there was an interaction between sex and rearing history. Hand‐reared tamarins overall had higher fecal cortisol levels, but while male parent‐reared tamarins had higher levels than females who were parent‐ reared, the reverse was true for hand‐reared individuals. There was a trend towards lower fecal cortisol levels in subordinate individuals, but no effect of status on salivary cortisol. Fecal but not salivary cortisol levels declined with increasing weight. We found little effect of group composition on cortisol levels in either saliva or feces, suggesting that as long as tamarins are housed socially, the nature of the group is of less importance. However, animals in off‐show enclosures had higher salivary and fecal cortisol levels than individuals housed on‐show. We suggest that large on‐show enclosures with permanent access to off‐exhibit areas may compensate for the effects of visitor disturbance, and a larger number of tamarins of the same species housed close together may explain the higher cortisol levels found in tamarins living in off‐show accommodation, but further research is needed

    Strengths of the Northwell Health Laboratory Service Line

    No full text
    From 2009 to 2015, the laboratories of the 19-hospital North Shore-LIJ Health System experienced 5 threatened interruptions in service and supported 2 regional health-care providers with threatened interruptions in their laboratory service. We report our strategies to maintain laboratory performance during these events, drawing upon the strengths of our integrated laboratory service line. Established in 2009, the laboratory service line has unified medical and administrative leadership and system-wide divisional structure, quality management, and standardization of operations and procedures. Among many benefits, this governance structure enabled the laboratories to respond to a series of unexpected events. Specifically, at our various service sites, the laboratories dealt with pandemic (2009), 2 floods (2010, 2012), 2 fires (2010, 2015), and laboratory floor subsidence (2013). We were also asked to provide support for a regional physician network facing abrupt loss of testing services from closure of another regional clinical laboratory (2010) and to intervene for a non-health system hospital threatened with closure owing to noncompliance of laboratory operations (2012). In all but a single instance, patient care was served without interruption in service. In the last instance, fire interrupted laboratory services for 30 minutes. We conclude that in a large integrated health system, threats to continuous laboratory operations are not infrequent when measured on an annual basis. While most threats are from external physical circumstances, some emanate from unexpected administrative events. A strong laboratory governance mechanism that includes unified medical and administrative leadership across the entirety of the laboratory service line enables successful responses to these threats
    corecore