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Biomedical subjects

C Hastings

Publications and source records attributed to C Hastings.

At least 19 recordsLinked to original sources
PubMed2000

Nursing leaders predict top trends for 2000.

Nursing Management's Editorial Advisory Board predicts the top 10 trends that will impact nurse leaders in 2000. Use them to lead in the new millennium.

Attitude of Health Personnel↗
PubMed1999

Diurnal variation in saliva estriol level during pregnancy: a pilot study.

OBJECTIVE: The object of the study was to characterize daily values and patterns of salivary estriol levels during normal pregnancy at mid to late gestation. STUDY DESIGN: We measured salivary estriol levels in a clinical research center setting with an established enzyme-linked immunosorbent assay. Fourteen pregnant women (24-36 weeks' gestation) submitted unstimulated saliva samples hourly from 10:00 am until 10:00 pm and at midnight and 2:00, 4:00, 6:00, and 8:00 am. RESULTS: Each subject demonstrated greater salivary estriol levels at night (10:00 pm-6:00 am) than in the daytime (8:00 am-9:00 pm, P <.001). Salivary estriol levels consistently increased at 10:00 pm, peaked at 4:00 am, and returned to daytime levels between 6:00 and 7:00 am. Salivary estriol concentrations were stable during daylight hours. CONCLUSIONS: (1) There was a dramatic diurnal variation in salivary estriol levels (nadir during daylight with nighttime apogee). (2) Diurnal patterns and salivary estriol levels were consistent in each of 14 subjects evaluated in the latter half of pregnancy. Samples for baseline measurements of salivary estriol level should be obtained during daylight hours (8:00 am-8:00 pm).

Adolescent↗
PubMed1998

A meta-analysis of salivary estriol (sE(3)) as a means to identify women at risk for preterm birth due to fetal-placental endocrine mechanisms.

Objective: 1) Analyze overall performance of salivary estriol testing in two similarly conducted large multicenter prospective trials and 2) gain information regarding the highly integrated and regulated endocrine mechanisms controlling parturition.Methods: Meta-analysis of evaluable mother-perinate dyads from two large prospective trials was conducted. Overall, 993 pregnant women were followed prospectively with weekly saliva samples from 24 weeks to delivery.Results: 1) Occurrence of a single positive test (sE(3) >/= 2.1 ng/mL) predicted delivery prior to 37 weeks gestation (P <.0003; OR 3.4, 95% CI 1.7-6.8). If a rescreen test at one week was also >/=2.1 ng/mL (8.9% of all subjects) then relative risks of preterm birth increased to 6.86 CI (3.2-14.5) P <.0001. Having two consecutive positive tests was associated with a mean time to delivery of 2.3 weeks (negative predictive value of 97%). 2) Survival analysis of women delivering at term and preterm demonstrated that sE(3) >/= 2.1 ng/mL predicted onset of labor and birth in approximately 3 weeks:Conclusion: Meta-analysis of these two large prospective trials confirms that 1) an sE(3) >/= 2.1 ng/mL provides timely warning of a presumed endocrine signal for impending preterm and term parturition, 2) the 2-3 week mean time to delivery after a positive signal allows time for intervention, and 3) lack of a positive sE(3) signal allows a confident prediction (NPV) that delivery will not occur within 2-3 weeks.

Journal Article↗
PubMed1997

Cloning and characterization of the calreticulin gene from Ricinus communis L.

A full-length cDNA encoding a calreticulin-like protein was isolated by immune-screening a germinating castor bean endosperm cDNA library with antisera raised to the total lumenal fraction of purified plant endoplasmic reticulum. The calcium-binding properties of the recombinant protein were characterized and shown to be essentially identical to those reported for the mammalian calreticulin. Calcium overlays and immune blot analysis confirmed the endoplasmic lumenal identity of this reticuloplasmin. Probing protein blots of endoplasmic reticulum subfractions with radio-iodinated calreticulin showed specific associations with various polypeptides including one identified as the abundant reticuloplasmin protein disulfide isomerase. Characterization of the corresponding genomic clones revealed that calreticulin is encoded by a single gene of 3 kb in castor. The full genomic sequence reveals the presence of 12 introns, 12 translated exons, and one exon containing the last three amino acids of the translated sequence and the 3'-untranslated region of the gene. Northern blot analysis of RNA isolated from various organ tissues showed a basal constitutive level of expression throughout the plant, but more abundant mRNA being detected in tissues active in secretion. This was confirmed by analysis of transgenic tobacco plants containing 1.8 kb of 5'-untranslated genomic sequence fused to the beta-glucuronidase reporter gene (GUS) showed a more localized pattern of expression. Activity being localized to the vasculature (phloem, root hairs and root tip) in vegetative tissue, and being strongly expressed in the floral organs including the developing and germinating seed.

Amino Acid Sequence↗
PubMed1996

Molecular characterisation of plant endoplasmic reticulum. Identification of protein disulfide-isomerase as the major reticuloplasmin.

Purified endoplasmic reticulum devoid of contaminating endomembranes has been isolated from both germinating and developing castor bean endosperm by a modified two-step centrifugation procedure. These membranes have been characterised for protein and lipid composition, subfractionated into lumenal and integral membrane protein fractions, and antisera raised to these two components. A cDNA clone encoding a major lumenal protein of 55 kDa was cloned using affinity-purified antisera and shown to encode a protein with strong sequence similarity to the endoplasmic reticulum lumenal chaperone protein disulfide-isomerase. Northern and Southern blot analysis showed that the mRNA from a single-copy gene was constitutively expressed in all tissues investigated, but was preferentially expressed in developing seed where it was the most abundant lumenal protein. Expression of the recombinant protein in Escherichia coli yielded a homodimer with a molecular mass of 110 kDa with protein disulfide-isomerase catalytic activity, thus confirming identity of this protein.

Amino Acid Sequence↗
PubMed1995

Salivary estriol as risk assessment for preterm labor: a prospective trial.

OBJECTIVE: Increased understanding of human parturition allows for novel approaches to (1) identification of women at increased risk for preterm birth and (2) development and controlled testing of etiology-based strategies to prevent preterm birth. STUDY DESIGN: Five hundred forty-two women were enrolled at five study sites in a prospective evaluation of salivary estriol in samples obtained weekly beginning at 22 weeks' gestation (Salest, Biex, Inc., Boulder, Colo.). Estriol concentrations were determined with a well-characterized enzyme-linked immunoassay. Women adjudged at either high risk or low risk for prematurity were evaluated through to delivery. RESULTS: A total of 267 women submitted serial samples that were analyzed; 241 women with singleton pregnancies submitted sufficient samples. Twenty-three women with singleton fetuses went into idiopathic preterm labor (without prior rupture of membranes) and were delivered preterm (mean 35 weeks' gestation); 182 were delivered at term (> or = 37 weeks' gestation). Mean (geometric) estriol concentrations were higher from 24 to 34 weeks in women with singleton pregnancies delivering preterm (p < 0.05). A surge in estriol concentrations occurred approximately 3 weeks before the onset of labor in both women delivering at term and those delivering preterm. This increase occurred approximately 4 weeks earlier in women delivered preterm versus term. Receiver-operator curve analyses showed that exceeding a 2.3 ng/ml saliva estriol level was associated with occurrence of preterm labor (71% sensitivity, 77% specificity, 23% false-positive rate). CONCLUSION: Detection of an early estriol surge or increased level (> or = 2.3 ng/ml) may be clinically helpful in identifying women at elevated risk for preterm labor and birth, allowing for evaluation of biologically based interventions in controlled trials.

Adult↗
PubMed1995

Differences in professional practice model outcomes: the impact of practice setting.

Over the past several years, involvement strategies such as professional practice models and shared governance strategies have been implemented in a variety of nursing practice settings. This article reviews the results of a secondary analysis of an evaluation of a professional practice model at a large academic medical center. This review compares critical care and general acute care nurses in terms of their perceptions of and satisfaction with work in a professional practice environment and identifies and contrasts significant predictors of general job satisfaction and turnover intent within the two groups. Implications of differences in outcomes in different settings are explored.

Humans↗
PubMed1995

Assessing the outcomes of professional practice redesign. Impact on staff nurse perceptions.

There are many reports in the literature of management innovations to redesign nursing roles and care delivery systems in response to the dramatic changes taking place in the healthcare environment. Few of these innovations have been evaluated systematically in terms of the dynamics and effects of change at the work group level. The authors present results of a longitudinal study evaluating the work group outcomes of a professional practice model implemented in an academic medical center. The strategy of integrating ongoing data collection and feedback into a process of continuous change also are presented.

Academic Medical Centers↗
PubMed1991

Bone marrow aspirate as an accessible and reliable source for critical laboratory studies.

STUDY OBJECTIVE: To determine whether laboratory studies performed on bone marrow aspirate can be used to predict values in the peripheral blood of human beings. DESIGN: Prospective correlative study. SETTING: Tertiary care pediatric hospital. TYPE OF PARTICIPANTS: Fifteen patients from the hematology-oncology division of Children's Hospital, Oakland, California, were studied during routine diagnostic bone marrow aspirations. INTERVENTIONS: Aliquots of serum and bone marrow obtained as part of routine diagnostic studies were analyzed. MEASUREMENTS AND MAIN RESULTS: Venous and bone marrow samples were analyzed for blood gas values, hemoglobin, and serum chemistries. Bone marrow specimens were found to reliably predict venous values of pH, bicarbonate, base excess, PCO2, hematocrit, sodium, chloride, and glucose. Bone marrow was not predictive of blood oxygenation, potassium, or ionized calcium. CONCLUSION: This study demonstrates in human beings what has previously been shown in animals--that the bone marrow is an alternative source of blood for a variety of laboratory studies.

Adolescent↗
PubMed1990

Repair of calvarial nonunions by osteogenin, a bone-inductive protein.

Efforts were taken to determine the dose of bovine osteogenin (OG) that would induce more bone than that induced by 20 mg of rat particulate demineralized bone matrix (DBM), the amount allowed by the confines of an 8-mm rat craniotomy defect. Dose-response studies were performed for demineralized bone matrix alone and osteogenin, partially purified from bovine demineralized bone matrix, plus rat insoluble collagenous bone matrix (M). Demineralized bone matrix alone (2.5, 5.0, 10, 20, or 40 mg) or osteogenin (0.0625, 0.125, 0.250, 0.50, or 1.0 mg) plus 25 mg insoluble collagenous bone matrix was implanted into the pectoralis muscle for 3, 5, and 7 weeks. Both materials induced time- and dose-dependent formation of bone. The three highest dosages of osteogenin (plus insoluble collagenous bone matrix) induced more bone than 20 mg demineralized bone matrix and seemed to accelerate bone repair. However, when implanted into the 8-mm rat craniotomy defect for 4 weeks, 20 mg demineralized bone matrix and 0.5 mg osteogenin (plus insoluble collagenous bone matrix) induced comparable amounts of bone. These results suggest different mechanisms for bone formation in heterotopic and orthotopic sites.

Animals↗
PubMed1989

Health status and disease activity in systemic lupus erythematosus.

The physical manifestations of disease activity and health status of patients with systematic lupus erythematosus (SLE) were measured in this study. Forty-nine patients completed the Arthritis Impact Measurement Scale (AIMS) and consented to examination for physical features of SLE documented by a Clinical Activity Index (CAI). Results showed a mean score of 22 on the AIMS and 6.6 on the CAI. The total scores for each measure were significantly correlated (r = 0.55, p less than 0.001), indicating a relationship between health status and clinical disease activity. The total score for CAI was significantly correlated with the physical activity, pain, and depression subscales of health status. The total score for health status was significantly correlated with mucocutaneous, musculoskeletal, and general features of CAI. Within scale correlations were also found. Mucocutaneous aspects of disease activity were significantly correlated with pain and depression. Musculoskeletal features were significantly correlated with physical activity and pain. General aspects of SLE, including fatigue, were significantly correlated with physical activity. The study concludes that there is a relationship between certain physical features of SLE and key components of health status.

Activities of Daily Living↗
PubMed1989

Molecular evolution of two actin genes from carrot.

We have isolated and sequenced two full-length cDNA clones encoding actin from carrot. The two carrot clones are almost identical at the nucleotide level, and are quite homologous to each other and to other plant actins at the amino acid level. In those regions where amino acid variation exists between the two genes from carrot, the differences have arisen from very simple changes at the nucleotide level. The most common changes are nucleotide insertion(s) coupled to the deletion of a different nucleotide(s) nearby in the DNA sequence, resulting in the restoration of the proper reading frame for the protein; thus, these changes can be viewed as multiple or coupled frameshift mutations. There are almost no base substitutions between the two carrot genes. In contrast to this, when the carrot actin nucleotide sequences are compared to those of a soybean actin gene or a maize actin gene, many base substitutions are observed (ca, 21.8% and 23.5%), more than half of which are third base changes which do not alter the protein sequence. At the amino acid level, both carrot genes show greater similarity to maize actin than they do to soybean actin, thus reinforcing the idea that plant actin genes diverged from a single common ancestral actin gene prior to the divergence of monocots and dicots.

Actins↗
PubMed1986

Plasma bupivacaine concentrations following lumbar epidural anaesthesia in children.

Plasma levels of bupivacaine were measured following lumbar epidural administration of 3 mg/kg of 0.5% plain solution in sixteen children. The peak levels were generally between 1.0 and 2 micrograms/ml, the highest being 2.9 micrograms/ml. No manifestations of toxicity were observed. There was a significant positive correlation between peak plasma levels and increasing age.

Aging↗
PubMed1983

Bacterial endocarditis complicating systemic lupus erythematosus.

Culture proven bacterial endocarditis occurred in 6 of 571 patients with systemic lupus erythematosus (SLE) admitted to the National Institutes of Health (NIH). Although 4 of the patients had a murmur noted on examination prior to developing endocarditis, only one of the 6 had a recognized valvular abnormality. Bacterial endocarditis followed dental procedures in 2 of the 6 patients; no precipitating events were recorded in the remaining 4. M-mode and 2-D echocardiography of 20 unselected SLE patients did not reveal previously unrecognized cardiac disease. There was an unexpectedly high frequency of bacterial endocarditis among SLE patients relative to all other connective tissue disease patients seen at the NIH.

Adult↗