The intersection of technology and care in the ICU

In this article the author describes the paradoxical nature of the relationship between technology and care in the ICU. Although technology enhances care by expanding the repertoire of competent nurses' responses to the patient, it simultaneously alienates nurse and patient, hence inhibiting care. This occurs when nurses and patients have different understandings of technology and when the nurse identifies with the values imposed by technology at the expense of acknowledging her own and the patient's vulnerability.     

A model of health care delivery in a child day-care setting

Many children in our country spend all or part of their days in group day care while their parents work or go to school. These children are not only at risk for day-care-related illnesses, but also may lack preventive health care because their parents have time constraints or financial barriers. A group of nursing faculty members found that by collaborating with early childhood educators, accessible and cost-effective health care could be provided to children at a campus day-care site. This collaboration allowed for the early detection of problems, thereby reducing barriers to learning. Furthermore, by entering a day-care system, nurses found opportunities to conduct health education and promotion that had a positive impact on children, parents, and day-care staff. This model, or components of it, could be replicated in similar settings.     

Peripheral monocyte culture supernatants of menopausal women can induce bone resorption: involvement of cytokines

Increased bone resorption is a mechanism contributing to bone loss in the postmenopausal period. Cytokines are involved in osteoclastic differentiation and, therefore, may play a role in the regulation of bone resorption. Several previous works showed the implication of interleukin-1 (IL-1), IL-6, and tumor necrosis factor-alpha (TNF alpha) in the modulation of bone remodeling. This study determines the concomitant production of the three cytokines and tests the bone-resorbing activity of peripheral monocyte supernatants. Four groups of women were studied: premenopausal women (n = 13; mean age, 47 +/- 0.9 yr), untreated postmenopausal women (n = 21; mean age, 52 +/- 0.6 yr), postmenopausal women treated with estrogens (n = 14; mean age, 54.2 +/- 1.1 yr), or postmenopausal women treated with ethanehydroxydiphosphonate (n = 12; mean age, 53.2 +/- 2 yr). Assignment to clinical groups was verified by plasma FSH and estradiol determinations. Lumbar spine bone mineral density was significantly higher in the premenopausal women group than in the three postmenopausal groups. Peripheral blood monocytes were cultured for 48 h with 20% autologous plasma, and after stimulation with lipopolysaccharides. IL-1, IL-6, and TNF alpha levels were measured by RIA in the monocyte surpernatants. The three cytokines were highly correlated to each other, IL-1 with IL-6 (r = 0.76; P < 0.001), IL-1 with TNF alpha (r = 0.89; P < 0.001), and IL-6 with TNF alpha (r = 0.89; P < 0.001). The mean levels of the three cytokines could not be compared because of the variations in the values. However, a trend toward lower levels in the three cytokines was noted in estrogen-treated women compared to the untreated postmenopausals. The bone-resorbing activity of monocyte supernatants, assessed by fetal long bone-resorbing assay, increased in untreated postmenopausal compared to that in premenopausal women (1.22 +/- 0.08 vs. 0.87 +/- 0.11; P < 0.05). In estrogen-treated patients, this activity decreased to premenopausal levels (0.89 +/- 0.04 vs. 0.87 +/- 0.11; P = NS). The resorbing activity was correlated to IL-1 (r = 0.28; P = 0.03), IL-6 (r = 0.52; P < 0.01), and TNF alpha (r = 0.48; P < 0.01). The addition of cytokine inhibitors and IL-1 receptor antagonist and TNF alpha antibodies to the supernatant bone culture medium induced a significant decrease in the calcium release. Those data show the involvement of several cytokines in the bone resorption process after estrogen deficiency.     

Detection of small changes in body composition by dual-energy x-ray absorptiometry

The ability of dual-energy x-ray absorptiometry (DEXA) to detect small changes in body composition was studied in 17 men and women during a dehydration-rehydration protocol. Scale weight (BW) and total mass (TM) from DEXA were highly related (r > 0.99) as were estimates of fat-free mass (r = 0.99) and percent fat (r = 0.97) from DEXA and densitometry. Changes in BW of approximately 1.5 kg due to fluid loss and gain were highly correlated (r = 0.90) with both changes in TM and soft-tissue mass (STM) by DEXA but less so (r = 0.67) with changes in lean-tissue mass (LTM). Mean changes in TM, STM, and LTM were not different (P > 0.05) from changes in BW. Estimates of bone mass and fat were unaffected by changes in hydration. We conclude that DEXA is able to detect small individual changes in TM and STM and is also useful for detecting group changes in LTM.     

Macrophage colony-stimulating factor release and receptor expression in bone cells

Colony-stimulating factors (CSF) may play a role in bone resorption. To examine whether osteoblasts secrete colony-stimulating activity (CSA) in response to parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP), conditioned medium (CM) from ROS 17/2.8 cells and primary rat osteoblasts were examined for induction of clonal growth of cultured rat bone marrow cells. Untreated cells constitutively secreted CSA, which increased with PTH and PTHrP treatment. The colonies formed were principally comprised of macrophages, and preincubation of CM with antiserum to murine macrophage colony-stimulating factor (M-CSF) neutralized most of the CSA, suggesting that the osteoblast-derived CSA was predominantly due to M-CSF. PTHrP treatment upregulated steady-state M-CSF mRNA levels. To investigate a paracrine role for M-CSF in bone we examined bone tissue and cells for the M-CSF receptor c-fms using immunohistochemical techniques and demonstrated staining of mature osteoclasts both in situ and after isolation. We conclude that M-CSF is responsible for the majority of the CSA released by PTH- and PTHrP-treated rat osteoblasts. In addition we identified CSF-1 receptor expression in mature osteoclasts. These data suggest that M-CSF is a mediator of osteoblast-osteoclast interaction in PTH- and PTHrP-induced bone resorption.     

The Cystatin-C gene is not linked to early onset familial Alzheimer's disease

The APP717 mutations discovered in only a few early onset Alzheimer's disease (AD) families have confirmed the genetic heterogeneity of this disorder. To identify the other gene(s) involved in the disease we selected the protease inhibitor, Cystatin-C, as a candidate gene. Cystatin-C is an amyloidogenic protein causing hereditary cerebral haemorrhage with amyloidosis-Icelandic type (HCHWA-I). It is localised with the beta-amyloid peptide in the arterial walls of AD brains. We have analysed the segregation of a polymorphic marker in this gene in 8 early onset AD families. Two early onset families showed clear non-segregation of the marker with the disease. When the 8 families are analysed together (assuming only one other gene is involved), they present exclusion linkage criteria. These data indicate that Cystatin-C is not the site of the defect in 2 families and is not likely to be in the other families analysed. We conclude that the deposition of Cystatin-C in AD is a secondary event in the disease process, and that this gene is not pathogenic in familial AD.     

The murine immune response to the male-specific antigen mouse testicular cytochrome c

Male and female A/J mice were examined for their ability to elicit T lymphocyte and antibody (Ab) responses to the male-specific Ag, mouse testicular cytochrome c (Mt cyt). T lymphocytes from both male and female mice primed in vivo responded to the Ag in in vitro proliferation assays, and the dose-response curves were statistically indistinguishable. In addition, similar levels of Ab to Mt cyt were observed in immunized male and female mice. The B cells producing the Ab had switched isotypes to IgG1 and IgG2a, indicating that the self-reactive T helper (Th) cells in male mice were functional. Thus, male mice do not appear to be immunologically tolerant to Mt cyt, at least at the Th and B lymphocyte levels. No evidence for disease was found in male mice primed with Mt cyt. Major histocompatibility complex (MHC) class II-positive antigen-presenting cells are present in the testes and these were shown in vitro to process and present Mt cyt to a T cell hybridoma specific for the synthetic peptide Mt cyt 93-104. However, the hybridoma was not activated in the absence of exogenous Mt cyt 93-104 or Mt cyt, indicating that endogenous Mt cyt is not normally processed in sufficient quantity to effectively load MHC class II molecules with this particular Mt cyt-derived peptide. Notwithstanding any immunologic privilege of the testes, the lack of tolerance to Mt cyt and its failure to elicit an autoimmune disease could extend from the low levels of processed Mt cyt Ag available for T cell recognition. The T cell response elicited by Mt cyt contrasts the lack of response to mouse somatic cytochrome c which differs from Mt cyt at 13 amino acid residues and is expressed in most tissues and at higher levels.     

Acute reduction of renal 11 beta-hydroxysteroid dehydrogenase activity by several antinatriuretic stimuli

The 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) activity of the kidney prevents access of cortisol or corticosterone to the renal mineralocorticoid receptor. Reduction of 11 beta-HSD activity by nutritional, hormonal, or pharmacologic factors might enhance the mineralocorticoid effect of these corticosteroids, thus causing sodium retention. To test this concept, we studied the effect on 11 beta-HSD activity of several antinatriuretic factors given orally to rats or exposed in vitro to rat renal tissue. Renal 11 beta-HSD activity was higher in fasted than fed rats (P < .05). Glucose, ethanol, and Toradol (Syntex Laboratories, Palo Alto, CA) given orally to fasted rats all reduced renal 11 beta-HSD activity by 20% to 40% (P < .05-.005) to levels similar to those observed in fed animals. Incubation of renal tissue from fasted rats with physiologic concentrations of insulin, ethanol, and Toradol also reduced 11 beta-HSD activity by 20% to 40% (P < .05-.01). These findings are consistent with the hypothesis that the antinatriuretic actions of these stimuli are due in part to alteration of renal 11 beta-HSD leading to greater mineralocorticoid effects in kidney.     

Fines Accumulation and Distribution in a Storm-Water Rain Garden Nine Years Postconstruction

Storm water control measures (SCMs), also known as best management practices (BMPs), such as rain gardens, are designed to infiltrate storm-water runoff and reduce pollutant transport to surface waters. The life span of these SCMs may be limited depending on the composition of sediments in runoff water. Settling of fine sediments may clog soil pore spaces, reducing the infiltration capacity of the soil and reducing the potential benefits of this SCM. A study was conducted on a Villanova campus rain garden that accepts runoff from an adjacent parking lot to determine if there was a relationship between the accumulation of fine sediments over time and the infiltration capacity. The soil textural profile within the rain garden was characterized prior to SCM installation (2001), after installation, after five years, and after seven years of receiving storm-water runoff. Infiltration data were collected by the single-ring infiltrometer method in 2006 and 2009. Differences in soil texture were found between locations within the infiltration basin, and accumulation of fines smaller than 0.1 mm was observed at both locations sampled in 2009. Infiltration rates were significantly different between the two locations measured within the rain garden, but infiltration rates did not change significantly over time within those regions. This SCM was designed at a 10:1 watershed to SCM area ratio, which is twice what is recommended by the PA DEP BMP Manual. The data collected over the seven years since installation indicate that while fines have accumulated in the SCM there has been no significant change in infiltration potential.