Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system

OBJECTIVES

Prominent physiological changes occurring throughout childhood and adolescence necessitate the consideration of age and sex in biomarker interpretation. Critical gaps exist in pediatric reference intervals (RIs) for specialized endocrine markers, despite expected influence of growth and development. The current study aimed to establish and/or verify RIs for six specialized endocrine markers on a specialized immunoassay system.

METHODS

Samples were collected from healthy children and adolescents (5 to <19 years) and apparently healthy outpatients (0 to <5 years) as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER). Serum samples were analysed for aldosterone, renin (plasma), thyroglobulin, anti-thyroglobulin, growth hormone, and insulin-like growth factor-1 (IGF-1) on the Liaison XL (DiaSorin) immunoassay platform. RIs (2.5th and 97.5th percentiles) were established for aldosterone, renin, thyroglobulin, anti-thyroglobulin, and growth hormone. Manufacturer-recommended pediatric RIs for IGF-1 were verified.

RESULTS

Age-specific RIs were established for aldosterone, renin, and thyroglobulin, while no age-specific differences were observed for anti-thyroglobulin or growth hormone. IGF-1 was the only endocrine marker studied that demonstrated significant sex-specific differences. Manufacturer-recommended IGF-1 RIs were verified for children aged 6 to <19 years, while those for children aged 0 to <6 years did not verify.

CONCLUSIONS

This study marks the first time that pediatric RIs for aldosterone and renin were established in the CALIPER cohort and highlights the dynamic changes that occur in water and sodium homeostasis during the first years of life. Overall, these data will assist pediatric clinical laboratories in test result interpretation and improve clinical decision-making for patients tested using Liaison immunoassays.

Habitat use by the endangered spotted-tailed quoll in a fragmented landscape

The spotted-tailed quoll (Dasyurus maculatus) is an endangered mesopredator endemic to Australia. It is generally considered a forest-dependent species associated with large, intact forested habitats. In Australia’s mainland, quoll research has typically been conducted in contiguous forest, and consequently, the species’ presumed forest-dependency might reflect sampling bias rather than preferred habitat niche. Recent studies have revealed that quolls also persist in fragmented agricultural landscapes, raising questions about their true habitat requirements and preferences. In this study, we investigated quoll habitat use within a fragmented agricultural landscape in mainland Australia. We deployed 42 lured camera traps to determine quoll habitat preferences across four broad vegetation types (open grassland, grassy woodland, dry sclerophyll forest, and wet sclerophyll forest) based on quoll activity and occupancy. Quolls were detected in all vegetation types, and quoll activity indicated a preference for dry sclerophyll forest and grassy woodlands, although this preference varied depending on the time of year. Our results suggest that quoll habitat use in mainland Australia is more flexible than previously assumed, and we recommend further research on factors that may influence habitat preference such as prey availability and seasonal behavior. Understanding the factors that drive habitat use by quolls outside of contiguous forested landscapes will inform and improve conservation and management strategies to ensure critical habitat for the species is protected and retained in an increasingly fragmented landscape.

'They only smoke in the house when I'm not in': understanding the limited effectiveness of a smoke-free homes intervention

Background

Children’s second-hand smoke (SHS) exposure in the home is highest in socio-economically disadvantaged areas. Personalized household air-quality measurements can promote changes in smoking that reduce SHS exposure. The ‘First Steps 2 Smoke-free’ (FS2SF) intervention is the first to trial this approach delivered as part of health professionals’ routine work. This paper reports the findings of qualitative interviews with participants that explored their experiences of the intervention and why outcomes varied.

Methods

120 women were recruited from the NHS First Steps Programme, which supports disadvantaged mothers. They received either personalized feedback on their home air quality and advice on reducing SHS or standard SHS advice. Qualitative interviews with 15 mothers were analyzed thematically using the Capability, Opportunity, Motivation, Behaviour (COM-B) model.

Results

The intervention increased women’s capability to change home-smoking behaviour, through increasing awareness and salience of SHS risks to their children, and motivation to act. However, taking effective action was constrained by their limited social and environmental opportunities, including others’ smoking in the home.

Conclusions

The FS2SF intervention was ineffective as it was unable to fully address the precarious, complex life circumstances that make creating a smoke-free home particularly difficult for women experiencing intersecting dimensions of disadvantage.

An evaluation of PlayStreets in the South Side neighborhood of Columbus, Ohio

AIMS

Outdoor play, physical activity, and social cohesion are crucial indicators of community health. PlayStreets, a street play initiative to engage local children and families in outdoor play, physical activity, and social interactions, were implemented in a low-income neighborhood in Columbus, Ohio throughout the summer of 2019. This article aims to describe the implementation of a hospital-sponsored PlayStreets model executed through support from a community health initiative and to assess neighborhood impact through parent and child surveys.

METHODS

Approximately 350 children attended the events and 69 surveys were collected. Descriptive statistics were used to analyze survey data.

RESULTS

The mean age of children was 7 years, and the majority of children who attended were male. If not for PlayStreets, 55% of caregivers reported that their children would be inside. Event satisfaction levels were high, and 54% of caregivers said that they had more contact with their neighbors because of the events.

CONCLUSIONS

Hospital buy-in and community support were crucial to the success of the event. We found that this model can successfully engage the local community while increasing opportunity for childhood outdoor play, physical activity, and neighborhood social interaction.

Adolescent alcohol exposure produces sex differences in negative affect-like behavior and group I mGluR BNST plasticity

Adolescent alcohol exposure increases the risk of developing alcohol use disorders (AUDs), yet the mechanisms responsible for this vulnerability remain largely unknown. One potential target for alcohol-induced changes is the circuitry that modulates negative affect and stress, two sexually dependent drivers of alcohol relapse. The bed nucleus of the stria terminalis (BNST) is a sexually dimorphic region that critically regulates negative affective- and stress-induced relapse. Group I metabotropic glutamate receptors (mGluR) are a target of interest due to their regulation of stress, anxiety behaviors, and BNST plasticity. The current studies investigate sex-dependent sensitivity to the effects of adolescent intermittent ethanol vapor exposure (AIE) on negative affect during acute and protracted alcohol withdrawal and following stress in adulthood. This work also assessed whether BNST group I mGluR-mediated long-term depression (LTD) was disrupted at these timepoints. During acute withdrawal, AIE altered LTD induced by the group I mGluR antagonist DHPG in females, but not males. During adulthood, stress unmasked persistent changes in DHPG-induced LTD and behavior that were not present under basal conditions. Females with an AIE history demonstrated enhanced negative affective-like behavior in the novelty-induced hypophagia test following restraint stress-a phenotype that could be blocked with systemic mGluR5 allosteric antagonism via MTEP. Conversely, males with an AIE history demonstrated elevated freezing in a contextual fear conditioning paradigm. These studies demonstrate long-lasting, sex-dependent phenotypes produced by AIE and suggest pharmaceutical interventions for alcohol use and comorbid disorders may be more effective if designed with sex differences in mind.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Multisensor Knowledge Systems

We describe an approach which facilitates and makes explicit the organization of the knowledge necessary to map multi sensor system requirements onto an appropriate assembly of algorithms, processors, sensors, and actuators. We have previously introduced the multisensor kernel system and logi cal sensor specifications as a means for high-level specifi cation of multisensor systems. The main goals of such a characterization are to develop a coherent treatment of multi sensor information, to allow system reconfiguration for both fault tolerance and dynamic response to environmental con ditions, and to permit the explicit description of control.

In this paper we show how logical sensors can be incorpo rated into an object-based approach for the interpretation of 3D structure. Considering the inherent difficulties in inter preting general configurations of lines in space, and consider ing the ubiquitousness of special line configurations in manu factured environments and objects, we advocate the use of computational units tuned to the occurrence of special config urations. The organized use of these units circumvents the inherent difficulties in interpreting general configurations of lines. After a brief examination of the problem of interpreting general configurations of lines in space, a number of compu tational units are proposed which are naturally derived from angular relations. The process of propagation (which allows interpretation to spread over the image) is also advocated. Such computational units and processes, which are simple and efficient, can be conveniently organized in a rule-based framework where the occurrence of the various special config urations can be tested. The multisensor knowledge system provides such a framework.

Human albumin eye drops as a therapeutic option for the management of keratoconjunctivitis sicca secondary to chronic graft-versus-host disease after stem-cell allografting

BACKGROUND

Keratoconjunctivitis sicca from chronic graft-versus-host disease (cgvhd) after allogeneic stem cell transplantation is common, leading to severe corneal damage and blindness if not treated. We retrospectively examined the efficacy and safety of pooled human albumin eye drops (haeds) for symptom relief in 40 stem-cell transplantation patients after other alternatives had failed.

METHODS

The Common Terminology Criteria for Adverse Events (version 4.0) and the cgvhd grading scale were used to compare response in the patients during January 2000 and July 2013. In addition, on days 1 and 30, the haeds were subjected to quality assurance testing for sterility, oncotic pressure, albumin measurement, viscosity, pH, and purity by protein electrophoresis.

RESULTS

Use of haeds resulted in symptom relief for 37 patients (92.5%); 3 patients (7.5%) failed to improve with use of haeds (p ≤ 0.0001). Of the 37 patients having symptom relief, 7 (19%) improved from grade 3 to no dry eye symptoms. Proportionately, post-treatment symptom improvement by two grade levels, from 3 to 1 (70%), was significantly higher than improvement by one grade level, from 3 to 2 (11%) or from 2 to 1 (19%, p ≤ 0.0001). Time to symptom relief ranged from 2 weeks to 28 weeks. Of the 40 patients, 38 (95%) had no adverse reactions. Days 1 and 30 quality assurance testing results were equivalent.

CONCLUSIONS

Complications of keratoconjunctivitis sicca were well managed and well tolerated with haeds when other remedies failed. Quality assurance testing confirmed that haeds were safe and stable in extreme conditions.

Potential wildlife sources ofYersinia pseudotuberculosisfor farmed red deer (Cervus elaphus)

During 1982 and 1983 15 serotype I, 6 serotype II, 1 serotype III and 3 untyped strains of Yersinia pseudotuberculosis were isolated from 675 apparently normal small mammals and birds from the Invermay farm and nearby rubbish tip with the following prevalence rates: feral cats 27.8%, Norway rats 8.6%, mice 5.5%, hares 3.8% rabbits 1.9% ducks 5.3%, sparrows 2.3%, seagulls 2.3% and starlings 1.7%. For rabbits a significantly higher prevalence of infection was found in the autumn/winter period (4.8%) than the spring/summer period (0%). Insufficient numbers of other mammals were obtained to demonstrate any seasonal difference in prevalence. All bird isolations were obtained between March and July (8/158) compared with none from August to October (0/144). It appears that a number of free-living species of small mammal and birds may be reservoir hosts for Y. pseudotuberculosis and potential sources of infection for red deer on the Invermay farm.

Cancer screening in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study (CCSS)

CRA6501

Background: Childhood cancer survivors may develop a second malignant neoplasm (SMN) and require surveillance to detect new cancers. Methods: We surveyed survivors and siblings from the CCSS, a cohort study of patients who have survived ≥5 years after a diagnosis of childhood cancer from 1970–86. We assessed compliance with the American Cancer Society's (ACS) guidelines for surveillance mammography, colonoscopy and PAP smears, and compared them to a matched population comparison group drawn from the 2003 National Health Interview Survey. Further, we examined compliance with the Children's Oncology Group (COG) guidelines for more frequent colonoscopy, mammography and skin exams in survivors at high risk for cancers of the colon (≥30 Gy pelvic, abdominal or spinal radiation), breast (≥ 20 Gy breast radiation in females) or skin (any radiation). Proportions screened were compared between groups with adjusted generalized estimating equations or log-binomial regression models. Results: There were 8318 survivors (50.6% male, mean age at interview 31.2 ± 7.3 years), 2661 siblings and 8318 population controls. 141/829 (17.6%), 592/855 (70.4%) and 3362/3690 (92.6%) eligible survivors reported a colonoscopy, mammogram, or PAP smear per ACS guidelines. Survivors were less likely than siblings (odds ratio [OR] 0.30; 95% confidence interval [CI] 0.18–0.49) and population controls (OR 0.63; CI 0.50–0.80) to have a colonoscopy, and less likely than siblings to have a PAP smear (risk ratio [RR] 0.98; CI 0.97–0.99). However, they were more likely than siblings (RR 1.14; CI 1.03–1.27) and population controls (RR 1.05; CI 1.01–1.10) to have a mammogram. Among survivors at increased risk for a SMN, only 92/809 (11.4%) reported a colonoscopy within the COG recommended 5-year period, 164/537 (30.5%) reported a mammogram within a 1-year period and 1288/4833 (26.7%) reported a skin exam. Care at a cancer center was associated with mammography (RR 1.91; 95% CI 1.02–1.27) and skin exam (RR 1.55; 95% CI 1.22–196) in high-risk patients. Conclusions: Childhood cancer survivors are not screened adequately for SMNs. Surveillance is very poor amongst those at highest risk for colon, breast, or skin cancer. Survivors and their physicians need education about the importance of surveillance.

No significant financial relationships to disclose.

Cancer screening in adult survivors of childhood cancer: A report from the Childhood Cancer Survivor Study (CCSS)

CRA6501

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

No significant financial relationships to disclose.

Trends and geographic variations in hospital admissions for asthma in Victoria. Opportunities for targeted interventions

OBJECTIVE

To describe variations in rates of hospital admissions for asthma in Victoria as health indicators of quality of primary care services and access.

DESIGN

Routine analyses of age and sex standardised admission rates of asthma in rural and metropolitan Victoria from 1993-1994 to 1999-2000.

RESULTS

There were 10,079 admissions for asthma, with an average of 2.71 bed days in 1999-2000. The admission rate for asthma decreased from 3.1/1000 (95% CI: 3.1-3.2) in 1993-1994 to 2.2/1000 (2.1-2.2) in 1999-2000, with a 37% reduction in rural regions and 26% in metropolitan regions. Sixteen primary care partnerships (small areas), 13 of them rural, had significantly higher admission rates than the Victorian average.

CONCLUSION

Although asthma hospital admission rates are falling faster in rural than metropolitan areas, rural areas still have higher admission rates with significant variation between small areas.

Fluorometric and mass spectrometric analysis of nonenzymatic glycosylated albumin

Albumin is the major transport protein in blood and intramolecular movement contributes to this function. Nonenzymatic glycosylation (NEG) of albumin occurs in diabetes and, in this study, fluorometric methods were used to determine the effect of increasing levels of NEG upon intramolecular movement in human serum albumin. Low levels of NEG significantly reduced and left-shifted Trp fluorescence, reduced quenching by acrylamide and inhibited penetration of bis-ANS, while these changes became only modestly more pronounced at higher levels of NEG. Mass spectrometry of tryptic and CNBr NEG-HSA fragments identified potential glycosylation sites and demonstrated only late glycosylation of the C- and N-terminal regions of the protein. Similar changes in diabetes may contribute to altered transport function in these patients.

Public policies to promote community-based and interdisciplinary health professions education

CONTEXT

Many rural and inner-city communities in the United States have persistent shortages of health professionals. In addition, health services are increasingly delivered in community-based settings by interdisciplinary teams. Yet, health professions students in the US continue to receive most of their training in urban hospitals.

OBJECTIVE

To assess the extent to which national and state government programs in the US that fund health professions education provide financial resources for community-based and interdisciplinary education in the health professions.

METHODS

Literature review.

FINDINGS

Most national and state government funding provided to health professions schools and clinical training sites in the US is not targeted to community-based and interdisciplinary education. Nationally, the Bureau of Health Professions, however, does administer some targeted grant programs. In addition, a number of states are addressing these needs through targeted appropriations to health professions schools and Medicaid payments to clinical training sites.

RECOMMENDATIONS

The US experience with government funding of health professions education suggests several questions that policymakers in other nations should consider and several principles for developing effective policies to promote community-based and interdisciplinary education.

Survey of the use of the interim hospital order in Scotland (1985-94)

A retrospective case note review was undertaken of all admissions to the State Hospital under an Interim Hospital Order between 1985 and 1994 (n = 73). This represented 89 per cent of all Interim Orders made by the Scottish courts during this time period. Thirty-one per cent of patients received a non hospital disposal at the end of the assessment. Seventy-eight per cent of the interim hospital orders were for a period of three months of less. The demographic, illness and offense backgrounds of the group is presented. In addition, the outcome of the assessment is discussed in the light of current legislative changes.

Comparison of insulin-like growth factor-I concentration in mammary secretions and serum of small- and giant-breed dogs

OBJECTIVE

To determine insulin-like growth factor-I (IGF-I) concentrations in canine mammary secretions and serum during lactation and to compare them between small and giant breeds of dogs.

ANIMALS

7 gestating Beagles and 4 gestating Great Danes.

PROCEDURE

Dogs were fed a common nutritionally complete and adequate gestation and lactation diet. Milk samples were collected at postpartum hour 12 and postpartum days 3, 7, 14, 21, and 28 after IV oxytocin administration. Two puppies/litter were identified at whelping for collection of blood samples corresponding to the days of milk sample collection plus days 35 and 42. Maternal blood samples were obtained on days 1, 7, and 42 from Beagles and days 1, 7, and 28 from Great Danes and were acid/ethanol extracted and analyzed by use of a radioimmunoassay.

RESULTS

Maternal serum IGF-I concentration was greater in Great Danes at all sample collection times. Similarly, colostrum from Great Danes contained more IGF-I, compared with that of Beagles (70 ng/ml vs 40 ng/ml, respectively). These values decreased to approximately 10 ng/ml by day 3 in both breeds and remained between 10 and 20 ng/ml for the duration of lactation. Growth rate and serum IGF-I concentration were greater in Great Dane puppies at birth to day 42.

CONCLUSIONS AND CLINICAL RELEVANCE

High IGF-I concentration in colostrum may be biologically important for newborn puppies. Body mass and serum IGF-I concentration are directly correlated in growing Beagle and Great Dane puppies. Serum IGF-I concentration may be an indicator of growth potential in dogs.

Dark adaptation in early primary biliary cirrhosis

BACKGROUND

The role of vitamin A in early primary biliary cirrhosis (PBC) remains uncertain.

METHODS

We assessed dark adaptation and assayed vitamin-A-related compounds in 10 patients with early PBC and a group of age- and sex-matched controls.

RESULTS

In patients compared with controls: (i) mean final light threshold value was 11.8% greater (p < 0.004), (ii) time taken to see the first light stimulus was longer (2.8 +/- 0.6 vs 1.4 +/- 0.2 min, mean +/- SEM; p < 0.03) and (iii) sensitivity to light stimuli was impaired after 6 min in the dark (p < 0.03). Three patients had an abnormal final light threshold despite receiving regular vitamin A; two had a low serum vitamin A. Raised serum bilirubin and increased age were the most important determinants of impaired dark adaptation.

CONCLUSIONS

Patients with early PBC have modestly impaired dark adaptation, despite standard vitamin A supplementation, although these changes may not have a significant effect on visual function. Vitamin A supplementation should be recommended for older patients with jaundice, but its effect should be carefully monitored.

Roles of nonphysician clinicians as autonomous providers of patient care

Studies were undertaken to assess the practice prerogatives of nonphysician clinicians (NPCs) in 10 disciplines that, collectively, are the major nonphysician contributors to the delivery of medical and surgical services. These disciplines include nurse practitioners, physician assistants, nurse-midwives, chiropractors, acupuncturists, naturopaths, optometrists, podiatrists, nurse anesthetists, and clinical nurse specialists. Marked differences were found in the practice prerogatives that states granted NPCs in the various disciplines. For most disciplines, the magnitude of their prerogatives correlated with the numbers of NPCs practicing in each state. At their maximal levels, state practice prerogatives authorized a high degree of autonomy and a broad range of authority to provide discrete levels of uncomplicated primary and specialty care. The recent growth in these prerogatives is fostering new opportunities for NPCs; however, it also is creating a pluralism that has the potential to further fragment the US health care system. It is time for regulatory integration and professional collaboration so that a health care workforce that includes a diversity of disciplines can be assured of providing a coherent set of patient care services in the future.

Vitamin E, lipids, and lipid peroxidation products in tardive dyskinesia

BACKGROUND

Lipid peroxidation has been postulated as a possible mechanism for neuronal damage in tardive dyskinesia, and this is supported by evidence of increased lipid peroxidation products in the cerebrospinal fluid of dyskinetic subjects.

METHODS

In this study plasma levels of vitamin E and vitamin A, measured by high-performance liquid chromatography, and of thiobarbituric acid-reactive substances (TBARS), were determined in 16 schizophrenic patients with tardive dyskinesia, 16 nondyskinetic patients all assessed by Abnormal Involuntary Movement Scale (AIMS), and 10 normal control subjects. Plasma cholesterol and triglyceride were also measured throughout. Vitamin E levels in plasma were corrected for total lipids.

RESULTS

Multivariate analysis of covariance showed significant differences when vitamin E and TBARS were compared in the three groups. Univariate t tests showed a significantly lower lipid-corrected vitamin E (p = .018) between the normal and dyskinetic group but not between the normal and the nondyskinetic schizophrenic patients. There was no difference in vitamin A levels between patients and normal controls. TBAR results showed a significant positive correlation between AIMS score and lipid-corrected TBARS.

CONCLUSIONS

This study confirms an abnormality associating lipid peroxidation and tardive dyskinesia and extends this abnormality to measurements of lipid-corrected vitamin E in plasma.

Partnership nursing home care for dementia: the Glasgow experience--one-year follow-up

The outcome of the transfer of 60 elderly patients suffering from dementia from hospital to nursing home care under a partnership contract was reviewed at 6 and 12 months following transfer. The nursing home population had fared badly compared with patients remaining in hospital during the first 3 months. This difference was less evident at 6 months follow-up and had disappeared at 12 months follow-up. It seems that a partnership agreement such as this can deliver a quality of health care at least as good as hospital treatment as long the transfer is handled carefully.

Partnership nursing home care for dementia: the Glasgow experience--one-year follow-up

The outcome of the transfer of 60 elderly patients suffering from dementia from hospital to nursing home care under a partnership contract was reviewed at 6 and 12 months following transfer. The nursing home population had fared badly compared with patients remaining in hospital during the first 3 months. This difference was less evident at 6 months follow-up and had disappeared at 12 months follow-up. It seems that a partnership agreement such as this can deliver a quality of health care at least as good as hospital treatment as long as the transfer is handled carefully.

An innovative teaching strategy for staff development departments. Olga and Bertha to the rescue

Efforts to address facility-wide educational topics in one staff development department have resulted in the development of innovative strategies to reach the maximum number of nurses with the greatest positive outcome. We were faced with the challenge of trying to improve discharge planning. A random chart review completed by the hospital utilization coordinator showed an appalling lack of discharge planning on the part of most hospital nursing staff. How would we entice nurses to attend inservice programs concerning such a potentially "dry" topic? Enter Olga and Bertha Smith, two characters devised to inject humor and entertainment into the educational sessions. The characters were role played by the authors and videotaped to show a standard scenario that demonstrated the intricate discharge planning needs of a young single mother (Olga) and her dependent mother (Bertha). Evaluations revealed extremely positive feedback for the characters as an enjoyable and effective way of teaching. Since then, Olga and Bertha have attracted, entertained, and educated nurses about three subsequent inservice topics.

Medicaid managed care: how do community health centers fit?

Managed care has brought about important changes in how the health care system is financed and services delivered. The authors describe the approaches adopted by community health centers to participate in Medicaid managed care and argue that these providers, commonly referred to as providers of last resort, have a role to play in this system. Many challenges lie ahead for these centers, such as the potential imposition of Medicaid block grants, the increasing number of uninsured persons, and cuts in both Federal grants and State budgets. These various forces may adversely impact health centers, leaving them with more uninsured patients and fewer resources.

Rapid induction of a novel costimulatory activity on B cells by CD40 ligand

BACKGROUND

T cells and B cells communicate by direct cell--cell interaction that is crucial to the functioning of the immune system. It is well established that the interaction between B-cell-expressed CD40 and T-cell-expressed CD40 ligand (CD40L) is critical for T-cell-dependent antibody responses, but the role of this interaction in T-cell responses is less clear. In this study, we have used mice with targeted mutations in the genes encoding CD40L or CD28 to investigate how the CD40-CD40L interaction induces on B cells a costimulatory activity that acts in addition to antigen to trigger T-cell growth.

RESULTS

We show that T cells from Cd40L-deficient mice induce a substantially reduced costimulatory activity on B cells compared to wild-type T cells, particularly at early time points. Surprisingly, T cells, from CD40L-deficient mice induce similar levels of B7-1 and B7-2 as do wild-type T cells. We further show that the CD40L-mediated induction of costimulatory activity precedes the induction of B7-1, B7-2 and the heat-stable antigen (HSA). CD4 T cells isolated from the CD28-deficient mice can receive costimulatory activity from CD40L-induced B cells, demonstrating that the induced molecules can costimulate T cells by a CD28-independent mechanism. We have generated a novel monoclonal antibody that inhibits the CD40L-induced costimulatory activity. Expression of the epitope detected by this monoclonal antibody correlates with the induction of the costimulatory activity, and the molecule recognized by the monoclonal antibody is a single chain of around 85 kDa, distinct from B7-1, B7-2, ICAM-1, ICAM-2, ICAM-3, HSA CD5, integrin and 4-1BB ligand.

CONCLUSIONS

Our results demonstrate that CD40L is both necessary and sufficient for rapid, T-cell-mediated induction of costimulatory activity on B cells. This costimulatory activity is distinct from B7-1 and B7-2, and is independent of CD28.

Regions of evolutionary conservation between the rat and human prohibitin-encoding genes

We have analyzed and compared the 5' promoter region, the intron structure and the exon-intron flanking sequences in the rat and human prohibitin-encoding genes (PHB). Comparative analysis of a 350-nt region immediately 5' to and including the first exon identifies eight highly conserved regions, four of which correspond to binding sites for known transcriptional control proteins (CCAAT box, 'SV40' site and two Sp1 sites). The promoter lacks a TATA box. Four transcription start points (tsp) clustered within a 35-bp region were identified by rapid amplification of cDNA ends (RACE). The exon-intron boundaries in rat and human are highly conserved, with identical positioning of splice junctions. PCR analysis with conserved exon primers was used to detect length variation between rat and human PHB, and length differences were observed in all of the introns.

Blood volume redistribution during cross-clamping of the descending aorta

We tested the hypothesis that occlusion of the descending aorta is associated with blood volume redistribution resulting in a relative hypervolemia in organs and tissues proximal to the level of occlusion. The study was performed on splenectomized dogs anesthetized with pentobarbital. Whole body scintigraphy with a Sophy DSX rectangular large field of view gamma-camera equipped with a high resolution collimator was used; Tc99m was used to label plasma albumin. The aorta was occluded at diaphragmatic and suprarenal levels in random order. The activity was counted during different stages of the experiments in the following regions of interest: brain, left and right ventricles, left and right lungs, left and right deltoid muscles, the liver, and intestines. Cross-clamping at the suprarenal level was not associated with significant changes in blood volume in any region of interest. The aortic cross-clamping at diaphragmatic level was associated with significant increases in the gamma-emission in all organs and tissues above the level of aortic occlusion by 8%-38%. Thus, the present study supports the hypothesis by demonstrating that cross-clamping of the aorta at diaphragmatic level is associated with an increase in blood volume in the organs and tissues proximal to the level of cross-clamping. Such an increase might represent the mechanism for well-documented increases in preload and blood flow above aortic occlusion, resulting in an additional (in addition to an increase in afterload) burden to the heart.

Effects of crossclamping the descending aorta on the high-energy phosphates of myocardium and skeletal muscle. A phosphorus 31-nuclear magnetic resonance study

The study was designed to test the hypothesis that a moderate decrease in upper body oxygen consumption observed during crossclamping of the thoracic aorta represents tissue hypoxia (possibly as a result of microcirculatory disorders) and results in adenosine triphosphate homeostasis disturbances. We averaged phosphorus 31-nuclear magnetic resonance spectroscopy measurements for 10 minutes with the use of a surface coil on the left ventricle and on the deltoid muscle during a 1-hour period before aortic crossclamping, during aortic crossclamping, and after aortic unclamping. Skeletal muscle creatine phosphate levels decreased 3.1% (p < 0.01), whereas the ratio of creatine phosphate to adenosine triphosphate decreased 2.2% (p < 0.05); glycolytic intermediates increased 70% (p < 0.01) and intracellular inorganic phosphate decreased 9% (p < 0.01). Myocardial creatine phosphate decreased 15% (p < 0.01), whereas the ratio of creatine phosphate to adenosine triphosphate decreased 5.3% (p < 0.01); glycolytic intermediates did not change, but intracellular inorganic phosphate almost doubled (p < 0.05). These data suggest that observations of reduced upper body oxygen consumption after aortic crossclamping are consistent with the effects of skeletal muscle hypoxia. Changes in myocardial metabolites may result from transient ischemia caused by the increased wall stress.

Effect of mecillinam on peptidoglycan synthesis during the division cycle of Salmonella typhimurium 2616

The effects of mecillinam, ampicillin and cephalexin on peptidoglycan synthesis in Salmonella typhimurium 2616 have been studied at equivalent concentrations or "isoactivities". Using antibiotics at isoactivities allows a direct comparison of the biochemical effects of different antibiotics. When mecillinam was added at different times during the division cycle at a concentration that produced 50% inhibition of peptidoglycan synthesis in an exponential culture over a short period of time, the inhibition of synthesis was greatest in the newborn cells and least in the dividing cells. Antibiotic competition experiments showed that mecillinam preferentially bound to penicillin-binding protein 2 in S. typhimurium 2616. High performance liquid chromatography analysis of the residual peptidoglycan synthesized in the presence of mecillinam showed an unexpected increase in pentapeptides and a significant increase in cross-linking. Other antibiotics added at equivalent activities did not show an increase in cross-linking.

Haemodynamic changes and oxygen uptake during crossclamping of the thoracic aorta in dexmedetomidine pretreated dogs

This study was designed to test the hypothesis that the alpha 2 adrenergic agonist, dexmedetomidine (DEX), decreases tissue oxygen demand thereby increasing tolerance to hypoxic insult. In 17 anaesthetized dogs, cardiac output was measured with thermodilution, blood flow through the inferior caval vein was determined using an electromagnetic flowmeter, and oxygen consumption was calculated by the Fick principle. The animals were divided into three groups: control group (n = 5), D3 and D30 groups (n = 6 for each group) treated with two doses of DEX (3 micrograms.kg-1 and 30 micrograms.kg-1, respectively) prior to aortic crossclamping. Upon crossclamping of the thoracic aorta, the cardiac index decreased in all three groups with the largest decrease in the D30 group, and the smallest decrease in the control group. Blood flow through the inferior vena cava decreased in all three groups of animals while blood flow through the superior caval vein increased in the control group, did not change in the D3 group, and decreased in the D30 group. Oxygen saturation in mixed venous blood increased in the control group, did not change in the D3 group and decreased in D30 group. Blood flow and oxygen uptake in the lower part of the body decreased in all groups. Oxygen consumption in the upper part of the body decreased equally in all three groups. Arterial lactate concentrations increased almost two-fold in the control group while it increased by only 30% in animals treated with DEX. A lesser increase in lactate concentrations and oxygen extraction in tissues below aortic crossclamping is consistent with the hypothesis that DEX decreases tissue oxygen requirement which might prove particularly useful in clinical situations where tissue hypoxia is expected.

Angiotensin and Adrenoceptors in the Hemodynamic Response to Aortic Cross-clamping

This study was designed to test the hypothesis that activation of adrenoceptors and/or the renin-angiotensin system plays an important role in the overall hemodynamic response to aortic cross-clamping. The experiments were performed on anesthetized rats pretreated with either saline (control group), an angiotensin-converting enzyme inhibitor (enalapril maleate, 2 mg/kg), an alpha 1-adrenergic antagonist (prazosin hydrochloride, 0.5 mg/kg), a beta-adrenergic antagonist (propranolol hydrochloride, 5 mg/kg), or an alpha 2-adrenergic antagonist (atipamezole, 5 mg/kg). Cross-clamping of the thoracic aorta was associated with an expected increase in mean arterial pressure and systemic vascular resistance in all animals. During the period of cross-clamping, cardiac output gradually decreased in all groups. Animals pretreated with the alpha 1-adrenergic antagonist or the angiotensin-converting enzyme inhibitor developed hypertension of a lesser degree than the control animals, while rats pretreated with the beta-adrenergic or alpha 2-adrenergic antagonist demonstrated a greater arterial hypertension than the control animals. The possible mechanisms underlying the observed differences are discussed. In conclusion, the present study confirms the posed hypothesis that the reninangiotensin and sympathetic nervous systems play an important role in hemodynamic response to cross-clamping of the thoracic aorta.

Secular trends in nosocomial primary bloodstream infections in the United States, 1980-1989. National Nosocomial Infections Surveillance System

More than 25,000 primary bloodstream infections (BSIs) were identified by 124 National Nosocomial Infections Surveillance System hospitals performing hospital-wide surveillance during the 10-year period 1980-1989. These hospitals reported 6,729 hospital-months of data, during which time approximately 9 million patients were discharged. BSI rates by hospital stratum (based on bed size and teaching affiliation) and pathogen groups were calculated. In 1989, the overall BSI rates for small (less than 200 beds) nonteaching, large nonteaching, small (less than 500 beds) teaching, and large teaching hospitals were 1.3, 2.5, 3.8, and 6.5 BSIs per 1,000 discharges, respectively. Over the period 1980-1989, significant increases (p less than 0.0001) were observed within each hospital stratum, in the overall BSI rate and the BSI rate due to each of the following pathogen groups: coagulase-negative staphylococci, Staphylococcus aureus, enterococci, and Candida species. In contrast, the BSI rate due to gram-negative bacilli remained stable over the decade, in all strata. Except for small nonteaching hospitals, the greatest increase in BSI rates was observed in coagulase-negative staphylococci (the percentage increase ranged between 424% and 754%), followed by Candida species (219-487%). In small nonteaching hospitals, the greatest increase was for S. aureus (283%), followed by enterococci (169%) and coagulase-negative staphylococci (161%). Our analysis documents the emergence over the last decade of coagulase-negative staphylococci as one of the most frequently occurring pathogens in BSI.