Blood donation in a large urban centre of southeast Brazil: a population-based study.

OBJECTIVES: This study aimed to estimate the prevalence and characterise potential blood donors and non-donors in a well-populated and representative urban area of Southeastern Brazil. BACKGROUND: Studies on blood donation usually evaluate individuals who donate. Population-based studies may contribute to characterise those who never reach the blood centre, trying to increase the range of donors. STUDY DESIGN AND METHODS: This was a secondary analysis of a population-based survey and a blood donor motivation study [Recipient Epidemiology and Donor Evaluation study (REDS II) International]. In a cross-sectional study 4047 individuals representing a metropolitan area answered the question 'Have you ever donated blood at least once in your life?'. The profiles ('Yes/No') were compared. Non-donors from this reference population were compared with donors of a local blood center, in a case control analysis. RESULTS: A total of 69·0% of the population had never donated blood and was composed mostly of women, younger than 30 years old, people not contributing to social security and not subscribing to newspapers. In the case-control study, the likelihood of donating was higher for: men, younger than 50 years old, longer time of education, married, participating in political campaigns and with a good self-perception of health. The factors associated with no blood donation were: self-reported mixed or white race/ethnicity, income higher than two minimum wages and belonging to trade union, political, religious/spiritual, or other social group and worse self perception of health. CONCLUSIONS: This population-based study allowed us to characterise a high proportion of people that never reaches the blood centre. The results may be used to diversify the donor profile, creating strategies to target those least likely to donate blood, as women, white people and those with higher income and purchasing power.

Inventory management.

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Differentially expressed genes in the rat cochlear nucleus.

The cochlear nucleus is the first central pathway involved in the processing of peripheral auditory activity. The anterior ventral cochlear nucleus (AVCN), posterior ventral cochlear nucleus (PVCN) and dorsal cochlear nucleus (DCN) each contain predominant populations of neurons that have been well characterized regarding their morphological and electrophysiological properties. Little is known, however, of the underlying genetic factors that contribute to these properties and the initial steps in auditory processing. Serial analysis of gene expression (SAGE), supported by microarray experiments, was performed on each subdivision of the rat cochlear nucleus to identify genes that may sub-serve specialized roles in the central auditory system. Pair-wise comparisons between SAGE libraries from the AVCN, PVCN and DCN were correlated with microarray experiments to identify individual transcripts with significant differential expression. Twelve highly correlated genes were identified representing cytoskeletal, vesicular, metabolic and g-protein regulating proteins. Among these were Rgs4 which showed higher expression in the DCN, Sst and Cyp11b1 with very high expression in the AVCN and Calb2 with preferential expression in the PVCN. The differential expression of these genes was validated with real-time reverse transcriptase-polymerase chain reaction. These experiments provide a basis for understanding normal auditory processing on a molecular level and a template for investigating changes that may occur in the cochlear nucleus with hearing loss, the generation and percept of tinnitus, and central auditory processing disorders.

Oestrogen receptor-immunoreactive neurons in the trigeminal sensory system of male and cycling female rats.

Many common craniofacial pain conditions are more prevalent in women than men and may be related to the phase of the menstrual cycle. Long-term effects of oestrogen in the nervous system are produced by receptor-mediated [oestrogen receptor alpha (ERalpha) and beta (ERbeta) isoforms] mechanisms; however, it is not known if the distribution of ER-positive neurons in the trigeminal system is similar in males and females. Quantitative immunocytochemistry was used to compare the distribution of ERalpha-labelled neurons in the trigeminal brainstem complex (TBC) and ganglion of male and female rats at different stages of the oestrous cycle. A high density of ERalpha-labelled neurons was seen in the superficial laminae (I-III) throughout the trigeminal subnucleus caudalis (Vc) and the upper cervical dorsal horn. Counts of ERalpha-positive neurons in laminae I-III were similar for prooestrous and dioestrous females, while males had fewer cells. The deeper laminae (IV-V) of the Vc and the cervical dorsal horn had few ERalpha-positive neurons in all groups. At the region surrounding the central canal at caudal levels of the Vc, prooestrous females had more ERalpha-positive neurons than dioestrous females or males. Few labelled cells were seen rostral to the trigeminal subnucleus interpolaris/caudalis transition region (Vi/Vc) in any group. In the trigeminal ganglion, prooestrous and dioestrous females had a moderate (8-10%) number of nuclear-labelled small or medium-sized neurons, while males had fewer labelled cells (4.5%). Qualitatively, the pattern of staining for ERbeta was similar, although weaker, than for ERalpha in the trigeminal dorsal horn or ganglion. These results were consistent with the hypothesis that oestrogen acts through trigeminal ganglion cells and caudal portions of the Vc to modulate sensory and autonomic aspects of craniofacial pain in a sex-related manner.

A study of the use of past experiences in clinical decision making in emergency situations.

Making decisions to call emergency assistance to patients is an important dimension of nursing practice. Most usually these decision making situations are uncertain and it is expected nurses rely on past clinical experiences. This study, approved by the ethics committees of both a university and an area health service, aimed to describe nurses' reliance on past experiences and identify associated judgement strategies (heuristics). Thirty-two registered nurses with five or more years experience were interviewed. Main findings were: nurses did use their past experiences and these experiences were used in the form of the three "classic" heuristics, representativeness, availability and anchoring and adjustment. It can be concluded past experiences are intrinsic to decision making and this has implications for both the clinical components of nursing educational programs and staffing allocations made by administrators. Some nurses, however, did not include referral to past experiences in their decision-making accounts which may be a limitation of the study design.

Clinical simulations: development and validation.

Simulations used as an educational strategy can mimic clinical reality bringing real life activity into the learning environment. This paper presents a conceptual approach to simulation development and validation that is applied to develop assessment simulations for both childbirth and triage situations. A process-based method of presenting information to the learner in the assessment phase is incorporated in simulations developed from actual clinical cases. The uncertain conditions of assessment are recognized as mirroring practice reality and validation of this construct and that of expertise are considered. Use of these simulations has the potential to provide learners with the opportunity to experience dimensions of simulated practice reality and educators with an experiential strategy that can be used to prepare students and also clinicians who are unfamiliar with new clinical practice areas.

Partnership for front-line success: a call for a national action agenda on workforce development.

Despite more than a decade of dialogue on the critical needs and challenges in public health workforce development, progress remains slow in implementing recommended actions. A life-long learning system for public health remains elusive. The Centers for Disease Control and Prevention and the Agency for Toxic Substances and Disease Registry in collaboration with other partners in federal, state, local agencies, associations and academia is preparing a national action agenda to address front-line preparedness. Four areas of convergence have emerged regarding: (1) the use of basic and crosscutting public health competencies to develop practice-focused curricula; (2) a framework for certification and credentialing; (3) the need to establish a strong science base for workforce issues; and (4) the acceleration of the use of technology-supported learning in public health.

Nurses' experiences of making decisions to call emergency assistance to their patients.

Patient survival often depends on decisions by nurses to call emergency assistance. The experiences of nurses calling emergency assistance have not been described. This descriptive study explored the experiences of registered nurses (n=32) using unstructured interviews. The main findings were that nurses questioned whether they were doing the 'right thing' calling the emergency team, sometimes collaborated with others prior to calling and most felt nervous and anxious. They recognized patient deterioration from feelings they had that something was wrong. However, they were not able 'to put their finger on it'. Knowing the patient and past experiences were involved in the recognition of deterioration. This association indicates the importance of experience in the development of clinical decision-making skills. Further, nurses calling emergency assistance need to be provided with the opportunity to debrief after calling. Their heavy reliance on subjective data before searching for objective data as outlined in the emergency calling criteria suggests that it is essential that nurses do not devalue or ignore concerns they may have about patients.

Recognition of patients who require emergency assistance: a descriptive study.

OBJECTIVE: The purpose of this study was to explore and describe the patient characteristics and the process of recognition nurses use to recognize patients about whom they are seriously worried. DESIGN: The study design was qualitative, exploratory, and descriptive, and it used in-depth interviews and a purposive sample. SETTING: The study setting included a teaching hospital and a peripheral hospital in a Sydney area health service. PARTICIPANTS: Participants included registered nurses (N = 32) with 5 or more years of experience and a history of calling the medical emergency team (MET). Mean years of experience as a registered nurse was 14 years, and the mean calls to the MET since employed in current hospital was 16 calls. FINDINGS: Primary findings showed that nurses relied on 4 patient characteristics to apply the MET criterion, "seriously worried about a patient." These 4 characteristics were (1) feeling "not right," (2) color, (3) agitation, and (4) observations marginally changed or not changed at all. The process used to gather and interpret information to recognize these patients who were deteriorating involved touching, observing, listening, feeling or sensing, and "knowing." In this process of recognition, nurses relied heavily on past experiences and knowledge to detect differences in patient condition. CONCLUSIONS: The 4 characteristics need to be included as an explanation for the MET criterion, "seriously worried about a patient." Additional validation and refinement of the 4 characteristics of the nonspecific MET criterion, "seriously worried about a patient," should be carried out. Continuing education programs in health care facilities need to support the use of subjective information in complex situations that result in decisions to call emergency assistance so patients whose conditions are deteriorating can be identified early and responded to rapidly.

Triage decision making: educational strategies.

Patient triage in Accident and Emergency departments requires emergency nurses to make rapid decisions based on their knowledge and experiences. The development of triage decision-making skills can be addressed through the use of simulations, 'thinking aloud' technique, reflection and the decision rules of experienced emergency nurses. Clinical educators and experienced emergency nurse mentors are encouraged to recognize that skill acquisition in triage decision making requires practice before registered nurses can engage fully in the process of triaging patients in the emergency department. It is essential to experience the process of triage decision making in order to develop an understanding of the clinical information attended to, the sequence in which the information is processed and the rules used to combine information leading to a decision on the triage category for each patient. By using triage simulations developed from 'real triage cases' the process of decision making can be experienced by nurses. Further, if these simulations are accompanied by the collection of verbal protocols, nurses have opportunities retrospectively to explore their decision making with reflection. In addition, the presentation and use of decision rules used by experienced triage nurses can enhance the development of skills in novice triage nurses.

Cloning of a unique lipase from endothelial cells extends the lipase gene family.

A new lipoprotein lipase-like gene has been cloned from endothelial cells through a subtraction methodology aimed at characterizing genes that are expressed with in vitro differentiation of this cell type. The conceptual endothelial cell-derived lipase protein contains 500 amino acids, including an 18-amino acid hydrophobic signal sequence, and is 44% identical to lipoprotein lipase and 41% identical to hepatic lipase. Comparison of primary sequence to that of lipoprotein and hepatic lipase reveals conservation of the serine, aspartic acid, and histidine catalytic residues as well as the 10 cysteine residues involved in disulfide bond formation. Expression was identified in cultured human umbilical vein endothelial cells, human coronary artery endothelial cells, and murine endothelial-like yolk sac cells by Northern blot. In addition, Northern blot and in situ hybridization analysis revealed expression of the endothelial-derived lipase in placenta, liver, lung, ovary, thyroid gland, and testis. A c-Myc-tagged protein secreted from transfected COS7 cells had phospholipase A1 activity but no triglyceride lipase activity. Its tissue-restricted pattern of expression and its ability to be expressed by endothelial cells, suggests that endothelial cell-derived lipase may have unique functions in lipoprotein metabolism and in vascular disease.

Education for clinical decision making in midwifery practice.

OBJECTIVE: To present an approach to developing clinical decision-making skills in midwifery students. DESCRIPTION: Use of simulations, 'thinking aloud' technique, reflection and the decision rules of experienced midwives are proposed for developing clinical-reasoning skills and acquiring skilled clinical knowledge. IMPLICATIONS: Educators are encouraged to recognise that skill acquisition in clinical decision making requires practise before students engage fully in the clinical setting. The process of decision making is emphasised as essential for students to experience so they develop an understanding of the clinical information attended to, the sequence in which the information is processed and the rules used to combine information to reach clinical judgements. By using clinical simulations developed from 'real cases' the process of decision making is able to be experienced by students. Further, if these simulations are accompanied by the collection of verbal protocols, students have opportunities to retrospectively explore their decision making with reflection. In addition, the presentation and use of decision rules of experienced midwives has the potential to enhance the development of skills in students.

Decision making by emergency nurses in triage assessments.

Triage assessment of patients on arrival at emergency departments involves complex decision making, resulting in categories being assigned to prioritize patients' needs for attention. The actual process of triage decision making has received limited attention. The aims of this study were to describe aspects of the triage decision-making process used by both more and less experienced nurses (n = 20) and to test the effect of uncertainty in the triage situation on the use of probability judgements (heuristics). Six triage cases based on actual triage situations were simulated to subjects, and their verbal protocols were collected. Protocols were transcribed and analysed. Main findings were: in conditions of higher uncertainty in triage situations all nurses used more probability in their judgements (t-test -2.37, df = 17, P = 0.03) with the heuristic of representativeness being relied on the most. The triage categories finally assigned for each triage situation showed no agreement on a specific triage category for each triage case and past triage experiences were used in decision making. The more experienced group reported higher estimations of correctness regarding the final category assigned, used more single previously experienced cases from memory, collected less data and made more judgements than the less experienced group. Further examination of the decision-making process of triage assessment should occur with attention to the variable use of triage categories, the role of past triage experiences in making judgements and development of triage decision rules for skilling nurses for triage.

Heuristics, servants to intuition, in clinical decision-making.

This paper explores intuitive judgements of nurses in clinical decision-making situations. The qualities of intuition are presented from both theoretical and practical perspectives and attitudes towards intuition from both nurses themselves and other health professionals are identified. An heuristic framework from cognitive psychology is applied to intuitive aspects of the clinical judgements that nurses have made. This interpretation is proposed as a partial explanation of intuition, and its use in advancing the understanding of intuition is recommended.

The expression of leptin and its receptors in pre-ovulatory human follicles.

The expression of leptin and its receptors was examined by reverse transcriptase-polymerase chain reaction and immunofluorescence in granulosa and cumulus cells of pre-ovulatory follicles and in meiotically mature oocytes obtained from women undergoing in-vitro fertilization. Leptin concentrations were measured in newly aspirated follicular fluids and in maternal serum before and after the administration of an ovulatory dose of human chorionic gonadotrophin. The findings demonstrate leptin expression at the mRNA and protein levels by granulosa and cumulus cells, and the presence of leptin in mature human oocytes. While an association between follicular leptin concentration and embryo development was not observed, a post-ovulatory increase in serum leptin concentration was associated with implantation potential. The results are discussed with respect to possible roles of leptin in early human development.

Leptin stimulates fetal and adult erythroid and myeloid development.

The ob gene product, leptin, has been shown in several studies to be involved in weight control and recombinant leptin recently has entered clinical trials to treat obesity. The leptin receptor (OB-R/B219) is expressed in a variety of protein isoforms not only in the central nervous system, but also in reproductive, and hematopoietic tissues. We reported recently that the OB-R/B219 was associated with a variety of hematopoietic lineages as well as the small fraction of cells containing the long-term reconstituting hematopoietic stem cells. Herein we report that leptin significantly stimulates the proliferation and differentiation of yolk sac cells and fetal liver cells and stimulates directly hematopoietic precursors. Leptin alone can increase the number of macrophage and granulocyte colonies, and leptin plus erythropoietin act synergistically to increase erythroid development. These data show that leptin has a significant, direct effect on early hematopoietic development and can stimulate the differentiation of lineage-restricted precursors of the erythrocytic and myelopoietic lineages. These observations along with a recent report strongly support our previous hypothesis that leptin has an unanticipated important role in hematopoietic and immune system development.

Clinical decision-making by midwives: managing case complexity.

In making clinical judgements, it is argued that midwives use 'shortcuts' or heuristics based on estimated probabilities to simplify the decision-making task. Midwives (n = 30) were given simulated patient assessment situations of high and low complexity and were required to think aloud. Analysis of verbal protocols showed that subjective probability judgements (heuristics) were used more frequently in the high than low complexity case and predominated in the last quarter of the assessment period for the high complexity case. 'Representativeness' was identified more frequently in the high than in the low case, but was the dominant heuristic in both. Reports completed after each simulation suggest that heuristics based on memory for particular conditions affect decisions. It is concluded that midwives use heuristics, derived mainly from their clinical experiences, in an attempt to save cognitive effort and to facilitate reasonably accurate decisions in the decision-making process.

Novel B219/OB receptor isoforms: possible role of leptin in hematopoiesis and reproduction.

Hematopoietic development is a complex process that involves a large number of growth factors and cytokines. Many cytokines are known to act on more mature, lineage-restricted cells of the hematopoietic system. However, no specific factors have yet been identified that induce the expansion of the most primitive hematopoietic cells without also inducing differentiation. To search for such factors, we isolated novel cell lines from the yolk sac in order to identify genes important in early hematopoietic and endothelial development. This approach led to the discovery of B219, a sequence that is expressed in at least four isoforms in very primitive hematopoietic cell populations and which may represent a novel hemopoietin receptor. The recently published receptor for the obesity (ob) gene product (leptin) is an isoform of B219 with a nearly identical ligand binding domain. B219/obr is expressed in the yolk sac, early fetal liver, enriched hematopoietic stem cells and in a variety of lymphohematopoietic cell lines. B219/obr is also expressed at high levels in adult reproductive organs. B219/obr maps to human chromosome 1p32, a region syntenic with the recently reported location of obr on murine chromosome 4 (ref. 5).

B cell differentiation factor-induced human B cell maturation: stimulation of intracellular calcium release.

We have recently identified a novel human B cell differentiation factor, 446-BCDF, derived from anti-CD3-stimulated peripheral blood (PB) T cells. This novel cytokine, which may act through a pertussis toxin-sensitive Gi-linked receptor, induces a 5- to 100-fold increase in immunoglobulin (Ig) secretion by SAC (0.001%, v/v)-activated PB B cells. Coculture of B cells with 446-BCDF induces a decrease in intracellular cAMP which is necessary but not sufficient to drive terminal B cell differentiation. A second signal appears to be required. We therefore measured Ca2+ flux in indo-1 AM-loaded PB B cells. Stimulation with 446-BCDF resulted in an immediate rise in intracellular Ca2+ comparable to that seen with the anti-IgM mAb HB57. Ca2+ appeared to be mobilized from internal stores as pretreatment with BAPTA but not EGTA inhibited the response. Ca2+ mobilization was critical for the induction of differentiation as BAPTA pretreatment of PB B cells completely inhibited Ig secretion without affecting cell viability. In contrast, neither SAC, rIL6, IL2, IFN-gamma, nor IL4 could mobilize Ca2+. Pertussis toxin, a Gi and G0 protein inhibitor, was able to inhibit 446-BCDF-induced Ca2+ flux as well as Ig secretion. To determine whether the Ca2+ flux was generated in the course of inositol phosphate turnover, we measured IP3 turnover and the translocation of PKC from cytosol to membrane. An increase in IP3 comparable to that seen with a monoclonal anti-human IgM antibody was noted and was specifically inhibited by the 446-BCDF-specific mAb 929. Interestingly, no membrane PKC was demonstrable in either SAC- or BCDF-stimulated B cells, although PMA (50 ng/ml) could directly activate PKC. To confirm these findings functionally, B cells were stimulated with SAC and 446-BCDF in the presence of two known PKC inhibitors, staurosporin and calphostin. No inhibition of Ig secretion was detected at any concentration tested (0.39-100 nM staurosporin and 0.0625-1 microM calphostin C). These data suggest that induction of B cell differentiation is a Ca(2+)-dependent and PTX-sensitive event.

B cell differentiation factor-induced B cell maturation: regulation via reduction in cAMP.

We have previously described a novel human B cell differentiation factor (BCDF), 446-BCDF, that is distinct biochemically and functionally from other cytokines. Since signal transduction pathways involved in human B cell differentiation have been incompletely studied and are poorly understood, we assessed the effects of 446-BCDF on various intracellular second messenger systems. After exposure of B cells to 446-BCDF, intracellular cAMP concentration started to decrease at 5 min and was significantly lower at 30 min and reached the lowest level at 4 hr. In most cases, cAMP concentrations returned toward baseline by 24 hr. A cAMP analog (dibutyryl cAMP), a stimulator of adenyl cyclase (forskolin), and phosphodiesterase inhibitors (aminophylline and IBMX) which inhibited the 446-BCDF-induced decrease in intracellular cAMP, inhibited 446-BCDF-induced B cell differentiation, suggesting that the fall in intracellular cAMP was a critical event in this process. To understand the mechanism involved in the reduction of cAMP, B cells were treated with pertussis toxin (PTX), a Gi protein inhibitor. Pertussis toxin blocked 446-BCDF-induced B cell differentiation as well, suggesting that 446-BCDF may function by stimulation of a Gi-linked receptor resulting in the inhibition of adenylate cyclase with a consequent reduction in cAMP. Other cytokines known to promote Ig secretion (IL2 and IL6) also caused a reduction in cAMP, suggesting that this pathway may be generally important in B cell differentiation. Taken together, these data suggest that at least one pathway of terminal maturation in B cells may involve the reduction of intracellular cAMP.