Postural control in response to unilateral and bilateral external perturbations in older adults.

BACKGROUND: Balance is an important determinant of physical function and falls risk. The ability to withstand external perturbations is important when walking on icy or uneven surfaces, whether the perturbations are bilateral or unilateral. RESEARCH QUESTION: This study sought to determine the effect of unilateral and bilateral standing perturbations on leg muscle activity in healthy older adults. METHODS: Participants experienced unilateral and bilateral standing perturbations of the treadmill. Surface electromyography (EMG) from lower limb muscles was recorded unilaterally. EMG onset latency and root mean square (RMS) amplitude of the muscle bursts were calculated. RESULTS: Older adults demonstrated a combined ankle/hip strategy, along with pre-activation and co-contraction of muscles in response to unilateral and bilateral stance perturbations. As well, older adults demonstrated higher levels of EMG, but no difference in the latency of burst onset, in bilateral than unilateral perturbation types. SIGNIFICANCE: When the stance limb was perturbed in the bilateral condition, the older adults responded with a Gastrocs EMG burst nearly 100% of the maximum EMG. The high level of EMG used, especially in the Gastrocs, during the bilateral perturbations may reduce the safety factor for falls in older adults. Older adults responded to the different perturbation demands by modulating EMG amplitude as opposed to the onset timing of EMG.

Triple VPI CGS 35601 reduces high blood pressure in low-renin, high-salt Dahl salt-sensitive rats.

We previously reported that CGS 35601, a potent triple inhibitor of angiotensin-converting enzyme, neutral endopeptidase, and endothelin-converting enzyme 1, completely normalized mean arterial blood pressure (MABP) in 36-week-old spontaneously hypertensive rats, a normal renin model. The aim of the present study was to determine the effects of this triple vasopeptidase inhibitor (VPI) on the hemodynamic profile of instrumented, conscious, and unrestrained Dahl salt-sensitive (DSS) rats, a gene-prone, high-salt diet-induced low-renin hypertension model. Male DSS rats (mean weight [+/-SEM], 385 +/- 10 g) were fed a normal diet (Group 1) or a high-salt diet (Groups 2 and 3; 8% NaCl in food) for 6 weeks and then instrumented with a carotid catheter and placed individually in metabolic cages for 30 days. The hemodynamic, hematological, and biochemical profiles were assessed daily. Dose-dependent treatment started after a 7-day stabilization period in Groups 1 and 2 (vehicle dosage, 250 microl/hr) and Group 3 (CGS 35601 dosages of 0.1, 1, and 5 mg/kg/day for 6 days per dose by means of constant intra-arterial infusion), followed by a 5-day washout period. Two additional groups included normotensive Wistar rats (Group 4) and DSS rats that received a double high-salt solid (8% NaCl) and liquid (1% NaCl) diet (Group 5). The MABP in rats receiving CGS 35601 decreased in a dose-dependent fashion toward the baseline level observed in DSS rats receiving a normal diet. The heart rate was unaffected. The hemodynamic profile returned to normal during the washout period. This novel triple VPI is a potent and effective antihypertensive agent with a safe short-term profile that may be of interest for treating hypertension and other cardiovascular diseases. Other hypertensive rat models are being tested.

Osteopontin induces increased invasiveness and plasminogen activator expression of human mammary epithelial cells.

Osteopontin (OPN) has been associated with enhanced malignancy in breast cancer, but its functional role in this disease is poorly understood. To study the effect of OPN on cellular invasiveness, basal OPN expression was first assessed in members of a progression series of human mammary epithelial cell lines (21PT: immortalized, non-tumorigenic; 21NT: weakly tumorigenic; 21MT-1: tumorigenic, weakly metastatic; MDA-MB-435 cells: tumorigenic, highly metastatic). The two lines which expressed lowest basal levels of OPN (21PT, 21NT) were then examined for up-regulation of invasive behavior in response to exogenous or transfected (endogenous) OPN. Both 21PT and 21NT showed increased invasiveness through Matrigel when human recombinant (hr)OPN was added to the lower chamber of transwells. Both also showed a cell migration response to hrOPN. Populations of 21PT and 21NT cells stably transfected with an OPN-expression vector showed higher levels of cell invasiness than control vector transfectants. Examination of transfectants for mRNA of a number of secreted proteases showed that only urokinase-type plasminogen activator (uPA) expression was closely associated with OPN expression and cellular invasiveness. Treatment of the parental 21PT and 21NT cells with exogenous hrOPN resulted in increased uPA mRNA expression and increased urokinase activity of the conditioned media. Both increased cell migration and induction of uPA expression are thus potential mechanisms of increased invasiness of breast epithelial cells in response to OPN.

Precise tuning of barnacle leg length to coastal wave action.

Both spatial and temporal variation in environmental conditions can favour intraspecific plasticity in animal form. But how precise is such environmental modulation? Individual Balanus glandula Darwin, a common northeastern Pacific barnacle, produce longer feeding legs in still water than in moving water. We report here that, on the west coast of Vancouver Island, Canada, the magnitude and the precision of this phenotypic variation is impressive. First, the feeding legs of barnacles from protected bays were nearly twice as long (for the same body mass) as those from open ocean shores. Second, leg length varied surprisingly precisely with wave exposure: the average maximum velocities of breaking waves recorded in situ explained 95.6-99.5% of the variation in average leg length observed over a threefold range of wave exposure. The decline in leg length with increasing wave action was less than predicted due to simple scaling, perhaps due to changes in leg shape or material properties. Nonetheless, the precision of this relationship reveals a remarkably close coupling between growth environment and adult form, and suggests that between-population differences in barnacle leg length may be used for estimating differences in average wave exposure easily and accurately in studies of coastal ecology.

Immunohistochemical localization of nephrocalcin, a kidney-specific glycoprotein, to renal cell carcinoma.

OBJECTIVES: Nephrocalcin (NC), an acidic glycoprotein produced by renal proximal tubule cells and functioning as an inhibitor of calcium oxalate monohydrate crystalization, has been previously shown to have increased urinary excretion in patients with renal cell carcinoma (RCC). The current study uses immunohistochemical techniques to localize NC to cells of primary RCC. METHODS: We studied 29 kidneys removed because of RCC. Slides were deparaffinized and stained after incubating with anti-NC antibody by using the avidin-biotin-peroxidase complex techniques. Uptake of stain by tumor cells and adjacent normal renal cells was compared. RESULTS: Twenty-seven kidneys (93%) showed positive staining for RCC tumor cells; 2 kidneys staining positive for normal proximal tubule cells failed to stain adjacent RCC tumor cells (7%). CONCLUSIONS: The data suggest that enhanced production of urinary NC in patients with RCC derives from cells of the primary tumor.

Impact of perinatal loss on the subsequent pregnancy and self: women's experiences.

OBJECTIVE: To describe the experience of a pregnancy after perinatal loss. DESIGN: Descriptive, open-ended responses to a self-completed questionnaire. SETTING: Questionnaires were distributed at a prenatal visit and completed in the office or at home. PARTICIPANTS: Seventy-two women who were 17 to 28 weeks pregnant, with a history of one or two perinatal losses. MAIN OUTCOME MEASURES: Themes that emerged from the women's responses to the questions. RESULTS: Three main dimensions, Past Pregnancy, Current Pregnancy, and Self constituted the overall framework for the themes of pregnancy anxiety, significant points in time, ways of coping, safe passage, social acceptance, binding-in, and grief and loss. CONCLUSIONS: Pregnancy after perinatal loss is characterized by guarded emotions, anxiety about this pregnancy, marking off the progress of the pregnancy in terms of fetal development and safety, and individual ways of coping to meet the tasks of pregnancy by seeking out or avoiding various behaviors. Women who have experienced perinatal loss would benefit from interventions to help them through these anxiety-filled pregnancies.

Facilitating care after perinatal loss. A comprehensive checklist.

Each year, one out of five women suffers the loss of a pregnancy. Such losses are more than statistics: to many mothers, they represent the death of a longed-for child. While increasing attention has been directed toward meeting the needs of these women, the services provided are often fragmented. The use of a comprehensive checklist for providing care facilitates continuity and consistency of care and offers structure and direction for the caregiver. In this manner, vital aspects of care are not omitted as the bereaved woman moves through the health-care delivery system.

Women's emotions and concerns during pregnancy following perinatal loss.

PURPOSE: To determine the specific emotions and concerns of women who are pregnant following a perinatal loss. STUDY DESIGN AND METHODS: Data were collected through a mailed questionnaire using an open response format. The sample consisted of 73 women on the membership mailing lists from two pregnancy-after-loss support groups. A content analysis was conducted on women's self-reports; five primary emotions and five main concerns were expressed during their pregnancies. RESULTS: "Anxious," "nervous," and "scared" were the most frequent emotions reported by these women. However, most women also included a positive emotion in their list, indicating the mixed emotions of their pregnancy experience. Eight categories of profound concerns were identified: "losing another baby," "overall health of the baby," "emotional stability of self," "impact of another loss on my future," "lack of support from others," "fear of bad news," "own impact on the baby," and "worries never end." Responses of currently pregnant women as compared with women retrospectively reporting on their last pregnancy experiences were essentially similar. CLINICAL IMPLICATIONS: Women pregnant after a previous perinatal loss are skeptical about pregnancy. Clinicians should be cognizant of the constellation of concerns and the simultaneous contrasting emotions experienced by these women in order to provide supportive prenatal care. Because the women's concerns are ongoing, responsive care should include asking about specific concerns throughout the pregnancy.

The cookie experiment revisited: broadened dimensions for teaching nursing research.

Nurse educators face the ongoing challenge of presenting increasingly complex nursing research methods to undergraduate and graduate students. The cookie experiment, a unique teaching strategy developed more than a decade ago by Thiel, has been refined and expanded to include hands-on quantitative and qualitative components while also serving as a way to lessen students'phobias about research. This creative and effective teaching strategy provides a user-friendly format that can be adapted as needed to present both basic and complex research concepts. The authors present this teaching strategy and discuss its applicability to undergraduate and graduate courses.

One foot in-one foot out: weathering the storm of pregnancy after perinatal loss.

Pregnancies after perinatal loss are oftentimes anxiety-laden and lacking in joy. This may lead to potential negative obstetrical and parenting outcomes. The purpose of this qualitative inquiry was to gain insights into women's pregnancy after perinatal loss experiences, including major features and helpful provider responses. Thirteen women, at varying points surrounding pregnancy after perinatal loss, participated in either a focus group or interview. An overall metaphor of "One Foot In-One Foot Out" and seven themes within four contexts emerged from the data. Women found themselves living within the contexts of (a) reliving the past, (b) trying to find a balance in the present, (c) recognizing their changed reality, and (d) living with wavering expectations. Seven themes characterized their navigation of the pregnancy: (1) setting the stage, (2) weathering the storm, (3) gauging where I am, (4) honoring each baby, (5) expecting the worst, (6) supporting me where I am, and (7) realizing how I've changed. Trying to stay balanced is the major challenge in pregnancy after perinatal loss.

Women's voices reflecting changed expectations for pregnancy after perinatal loss.

PURPOSE: To describe women's experiences of pregnancy after loss and their long-term effects of perinatal loss. DESIGN: Phenomenology. METHODS: Three focus groups were conducted in fall 1996 with a total of 21 women. These women varied in their obstetrical and loss histories. The time since their losses ranged from 34 years ago to the previous year. Data analysis was guided by Colaizzi's procedural steps. FINDINGS: Women's stories portrayed perinatal loss as a life-altering event. Women did not feel emotionally safe in their pregnancies after loss and were afraid that those babies too would die. Despite the differences in their obstetrical and loss histories and time since loss, similarities in their responses to pregnancy far outweighed their differences. These commonalities contained in six themes: (a) dealing with uncertainty, (b) wondering if the baby is healthy, (c) waiting to lose the baby, (d) holding back their emotions, (e) acknowledging that loss happened and that it can happen again, and (f) changing self. CONCLUSIONS: This study indicated many common concerns and experiences among women in response to perinatal loss and subsequent pregnancies. Variations were not linked to the number or gestational age of the losses. Care providers should acknowledge women's past losses, address their concerns during a current pregnancy, and recognize the potentially life-long effect perinatal loss may have on these women.

Maternal assignment of fetal personhood to a previous pregnancy loss: relationship to anxiety in the current pregnancy.

The degree of personhood a mother assigns to her dead fetus (i.e., whether she felt she lost a pregnancy or a baby) may help explain the meaning of a perinatal loss and the amount of anxiety experienced in a subsequent pregnancy. This descriptive study of 72 multigravidas with a history of one or two perinatal losses was conducted to understand the relationships between the assignment of fetal personhood and the influence of that assignment on state anxiety and pregnancy anxiety in a subsequent pregnancy. Assignment of personhood was significantly related to pregnancy anxiety and to the gestational age of the first loss but not to state anxiety. Understanding and responding to women's perceptions of perinatal losses and their significance for women may be one way to support them in subsequent pregnancies.

Contribution of human uropontin to inhibition of calcium oxalate crystallization.

Uropontin (UP) is known to inhibit the growth and nucleation of calcium oxalate monohydrate (COM) crystals, and it also impedes attachment of calcium oxalate crystals to cultured renal epithelial cells. However, its role in normal defense against renal crystallization, and in pathogenesis of nephrolithiasis is unclear. In this study we determined the effect of UP on aggregation of COM crystals as well as the inhibitory activity of UP on COM crystal growth and nucleation in a series of normal subjects, in order to assess the potential of UP as an important urinary inhibitor. The mean urinary excretion of UP measured by ELISA was 185 +/- 12 nmol/24 hr (mean +/- SEM) with a mean urine UP concentration of 131 +/- 13 nM. Uropontin isolated by immunoaffinity chromatography was a very potent inhibitor of COM crystal aggregation, with a mean UP concentration of 28 +/- 4 nM required for a 50% reduction in aggregation. The kDa for COM crystal growth inhibition determined from Langmuir type isotherms was 21 +/- 3 nM and the concentration required for 50% reduction in COM crystal growth rate was 16 +/- 2 nM. Inhibition of secondary nucleation was measured at a single concentration of 200 nM, which reduced the nucleation rate to 42 +/- 3% of control. Using a theoretical model of growth and aggregation inhibition at varying urine flow rates, we showed that inhibitory activity of UP would be significant for all subjects over a wide range of urine flow rates. Overall, UP is a potent inhibitor of COM aggregation as well as growth and nucleation. The urinary concentration of UP is in the range in which its contribution to inhibition of growth and aggregation are likely to be substantial. Thus, UP appears to be an important natural defense against renal crystallizations and nephrolithiasis.

Maximizing results with focus groups: moderator and analysis issues.

Focus groups can be used to gather rich, detailed descriptions of shared individual experiences and beliefs. Group process enhances the richness of the data obtained via this method. Nurses are skilled in gathering detailed and often sensitive information and applying therapeutic communication and interviewing techniques within groups. They can take advantage of these skills by using focus groups to collect qualitative data. To maximize the collection of high-quality data, pay specific attention to the selection and training of the moderator, the development of the interview guide, and the analysis that addresses intragroup and intergroup processes.