Provider Perspectives of Transitions of Care at a Tertiary Care Children's Hospital With a Hospitalist-Run Discharge Clinic

Children's hospitals are discharging patients to home with increasingly complex outpatient needs, making safe transitions of care (ToCs) of vital importance. Our study involved a survey of both outpatient providers and pediatric hospitalists associated with our medical center to better describe providers' views on the ToC process. The survey included questions assessing views on patient care responsibilities, resource availability, our hospitalist-run postdischarge clinic (PDC), and comfort with telemedicine. Our hospitalists generally believed that primary care providers (PCPs) did not have adequate access to important ToC elements, whereas PCPs felt their access was adequate. Both provider types felt it was the inpatient team's responsibility to manage patient events between discharge and PCP follow-up and that a hospitalist-run PDC may reduce interim emergency room visits. This study challenges perceptions about the ToC process in children and describes a generalizable approach to assessing provider perceptions surrounding the ToC within individual health systems.

Abstract P4-16-01: A novel approach to breast cancer prevention: Exploiting autologous fat grafting for the local delivery of cancer therapeutics

Background: Breast cancer remains a considerable health concern, despite major advances in the treatment and prevention of breast cancer. Inhibition of estrogen receptor signaling is one of the most effective therapies for patients with hormone receptor positive breast cancer. However, even after chemotherapy and hormonal therapy, local recurrence occurs frequently, and undesirable side effects lead to drug discontinuation in an estimated 40% of patients on adjuvant therapy.

Autologous fat transfer is an emerging therapy used in breast reconstruction to restore surgical deformities after lumpectomy, or to rebuild the breast following mastectomy. This is an attractive option for both radiated and non-radiated patients, as complication rates in both groups are exceedingly low. Fat is injected into the breast or surgical cavity to maximize its contact with local vascularized tissue, to promote re-vascularization and survival of the adipose tissue. Thus, fat cells are injected throughout the tissue surrounding the surgical margin. We hypothesize that harvested adipose tissue can be loaded with a lipophilic drug prior to its re-injection into the breast cavity and its surrounding tissue. With the release of drug from the transplanted adipose tissue over time, the local concentration of an anti-estrogen within the breast parenchyma would be increased and systemic toxicity may be minimized.

Method: Human adipose tissue was acquired from patients undergoing liposuction for autologous grafting. Tissue was washed with warm PBS, divided into 0.5 mL aliquots, and incubated in complete DMEM (10% FBS) containing increasing concentrations of 4-OH tamoxifen (0, 10, 20, or 40 uM) or fulvestrant (0, 0.1, 0.5, or 1.0 uM) for 12 hours. Following incubation, adipose tissue was washed thoroughly and co-cultured with MCF7 cells for 96 hours. Adipocyte co-cultured MCF7 were then collected and evaluated for proliferation, viability and effects on estrogen receptor signaling and compared to MCF7 directly exposed to anti-estrogens.

Results: When co-culturing tamoxifen- or fulvestrant-loaded human adipocytes with MCF7 breast cancer cells in vitro, we observed a dose-dependent reduction in cell proliferation (tamoxifen, 60% reduction; fulvestrant, 40% reduction) and viability (20%), comparable to directly drugged media. Examination of the molecular response to fulvestrant demonstrated a dose dependent down regulation of ER protein expression and activity (e.g. PgR and Cyclin D1). Currently, we are characterizing the pharmacokinetics of anti-estrogen uptake and release in both in vitro and in vivo.

Summary: Our preliminary data suggest that co-culturing human adipocytes with an anti-estrogen results in tumor growth inhibition and abrogation of estrogen receptor signaling. Human adipocytes used to fill the tumor bed cavity or mastectomy pocket could therefore be used as a vehicle to deliver anti-estrogens to residual tumor cells and prevent tumor regrowth. This method may be a novel technology to combine reconstructive surgery and anti-cancer therapy and prevention.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-16-01.

A polymorphism in the NPPA gene associates with asthma

BACKGROUND

Atrial natriuretic peptide (ANP) plays an important role in the lung and in augmenting allergic inflammation in asthma. The gene encoding ANP, NPPA, is located on chromosome 1p36, a region that has been linked to asthma.

OBJECTIVES

Determine associations between asthma and four common SNPs on the NPPA gene: C/G (rs13305986) in the promoter; G/A (rs5063) in Exon 1 resulting in NPPAMet32-->Val substitution; T/C (rs5065) in Exon 3 resulting in an Arg152-->Ter substitution; and T/C in the 3'UT region (rs5067). Methods A case-control design was used in White participants. The screening cohort consisted of 336 asthmatic cases who participated in a large clinical trial and 154, non-asthmatic controls. The replicate cohort consisted of 172 asthmatic cases from a second clinical trial and 115 healthy controls. Demographic characteristics were well matched for cases and controls in the screening cohort. Adjusted (age, gender, body mass index) odds ratio (OR) were calculated by chi(2) and logistic regression; a P-value of 0.0167 defined the threshold of significance.

RESULTS

The C allele of rs5067 was associated with asthma in the screening and replicate cohorts: adjusted ORs (95% confidence intervals) 0.5 (0.29-0.84; P=0.009) and 0.24 (0.11-0.53; P<0.0001), respectively. The C allele of rs5065 was associated with asthma in the screening cohort but not in the replicate. The population-attributable risk for asthma in carriers of the C allele for rs5067 was 23.3%.

CONCLUSIONS

For rs5067, the risks of asthma in carriers of the C allele in the screening and replicate cohorts were reduced by 50% and 76%, respectively. NPPA may be an important susceptibility gene for asthma.

Smooth muscle cell matrix metalloproteinase production is stimulated via alpha(v)beta(3) integrin

This study tests the hypothesis that alpha(v)beta(3) integrin receptors play a critical role in smooth muscle cell (SMC) migration after arterial injury and facilitate migration through the upregulation of matrix metalloproteinase (MMP) activity. We showed that beta(3) integrin mRNA was upregulated by SMCs in the balloon-injured rat carotid artery in coincidence with MMP-1 expression and early SMC migration. Treatment with the beta(3) integrin-blocking antibody F11 significantly decreased SMC migration into the intima at 4 days after injury, from 110.8+/-30.8 cells/mm(2) in control rats to 10.29+/-7.03 cells/mm(2) in F11-treated rats (P=0.008). By contrast, there was no effect on medial SMC proliferation or on medial SMC number in the carotid artery at 4 days. In vitro, we found that human newborn SMCs produced MMP-1 but that adult SMCs did not. This was possibly due to the fact that newborn SMCs expressed alpha(v)beta(3) integrin receptors, whereas adult SMCs did not. Stimulation of newborn (alpha(v)beta(3)+) SMCs with osteopontin, a matrix ligand for alpha(v)beta(3), increased MMP-1 production from 114.4+/-35.8 ng/mL at 0 nmol/L osteopontin to 232.5+/-57.5 ng/mL at 100 nmol/L osteopontin. Finally, we showed that stimulation of newborn SMCs with platelet-derived growth factor-BB and osteopontin together increased the SMC production of MMP-9. Thus, our results support the hypothesis that SMC alpha(v)beta(3) integrin receptors play an important role in regulating migration by stimulating SMC MMP production.

Access for low-income children: is health insurance enough?

OBJECTIVE

The Balanced Budget Act of 1997 authorizes $20 billion for states to expand health insurance coverage among uninsured low-income children. This study identifies lessons learned from the Medicaid Extension Demonstration, which was authorized by Congress to experiment with innovative approaches to providing health care coverage for low-income children. The three programs compare and contrast a variety of features that may enhance or detract from access, including a traditional Medicaid expansion, a private indemnity model, and a comprehensive managed care delivery system.

METHODOLOGY

Two waves of telephone surveys were conducted with a sample of parents of children participating in the Medicaid Extension Demonstration, and a comparison group of parents of children who were eligible but not participating. Descriptive and multivariate analyses were conducted to determine the impact of the demonstration on access to care.

RESULTS

Compared with those who were uninsured, children in the managed care program were more likely to have a medical home and a physician visit and were less likely to have an emergency room visit, and had lower levels of unmet need. Outcomes across the other two demonstration programs were less favorable.

CONCLUSIONS

This study suggests that simply providing a Medicaid card or private indemnity insurance card is not enough to ensure access to care. Future initiatives also need to consider the structure of the delivery system, especially the availability of a medical home (with adequate after-hours care), as well as the impact of discontinuous insurance coverage on access to and continuity of care.

Anti-CD86 (B7.2) treatment abolishes allergic airway hyperresponsiveness in mice

Allergic sensitization in asthma develops as a consequence of complex interactions between T cells and antigen-presenting cells. We have developed several in vivo models to study allergen-specific T cell and B cell function and their relevance to allergic airway hyperresponsiveness (AHR), focusing on the role of the costimulatory molecules CD80 and CD86. Treatment of mice with anti-CD86, but not anti-CD80, significantly inhibited increased serum levels of ovalbumin (OA)-specific IgE and IgG1, airway eosinophilia, and AHR both after 10 d of OA aerosol exposure (in the absence of adjuvant) and after intraperitoneal sensitization followed by repeated airway challenges. Inhibition of AHR was associated with decreased IL-4 and IL-5 levels in the BAL fluid of sensitized mice, suggesting impaired Th2 function in anti-CD86-treated animals. This effect was not seen when mice received treatment only before allergen challenge, indicating that anti-CD86 acts through inhibition of allergic sensitization and not simply by inhibiting the influx of inflammatory cells. These data suggest that the CD86 costimulatory ligand plays a major role in the development of allergic inflammation and AHR in allergen-challenged mice. Further, this study demonstrates that T-B cell interactions during allergic sensitization are amenable to therapeutic manipulation and that selective blockade of accessory signals can be an effective means for modulating distinct T cell functions.

Rural applications of telemedicine

OBJECTIVES

To describe the status of telemedicine in rural America, the characteristics of health care facilities using telemedicine technologies to serve rural patients, the volume and scope of services delivered, the costs associated with this care, and the funding sources.

METHODS

A screening survey was mailed to all 2472 nonfederal U.S. hospitals located outside metropolitan areas. Nonrespondents were interviewed by telephone. Those who reported some form of telemedicine capability, and all the telemedicine affiliates they named, became the sample for a detailed follow-up survey (N = 558) in January 1996.

RESULTS

Ninety-six per cent of all rural hospitals responded to the screener survey, and 89% of the 558 identified telemedicine facilities responded to the detailed follow-up survey (total respondents = 499). In this cross-sectional study, two thirds of the telemedicine respondents (340) were using only teleradiology. Of the 159 telemedicine programs pursuing other clinical applications, 67% had been using telemedicine for 2 years or less. Telemedicine facilities have tried many clinical specialty applications, the most common being radiology, cardiology, and orthopedics. At this early stage of technology diffusion, reported utilization of the telemedicine systems for both clinical and nonclinical applications was very low, and the unit costs of equipment acquisition and operating expenses were corresponding high. Programs most commonly used hospital financial resources and federal grants and contracts for support. Telemedicine networks planned to grow from an average of nine facilities to an average of 13 facilities during 1996.

CONCLUSIONS

Investment has been rapid in telemedicine, and the installed base reported in this survey was large, sophisticated, and growing rapidly. Nonclinical uses of the technology (e.g., meetings, training sessions, continuing medical education) were more common than clinical consultations, although the volumes of both were quite low. Investment and expansion to new sites were occurring in the absence of a favorable payor reimbursement environment and in spite of low volume at most operating sites, demonstrating optimism about the future of telemedicine and the potential for nonclinical applications.

CD23 deficient mice develop allergic airway hyperresponsiveness following sensitization with ovalbumin

The low affinity receptor for IgE (CD23) is reported to regulate immune and inflammatory events and as a result, it may have a role in the development of allergic airway inflammation and hyperresponsiveness (AHR). To test this hypothesis CD23-deficient mice were studied following different modes of allergic sensitization. Mice were actively sensitized either intraperitoneally with ovalbumin (OA)/alum or via the airways (10 days exposure to OA aerosol with no adjuvant). Passive sensitization was performed by intravenous injections of OA-specific IgE. Airway responsiveness, serum IgE and IgG levels were assessed together with airway inflammation. Passive sensitization followed by airway challenges resulted in increased OA-specific lgG and IgE in the serum of wild-type mice only, while both the CD23+/+ and CD23-/- groups developed tracheal smooth muscle hyperresponsiveness to electrical field stimulation, indicating that IgE/CD23-mediated immune functions may not be necessary for the development of allergic changes. Active sensitization of both CD23-/- and CD23+/+ mice resulted in increased serum levels of OA-specific IgE and lgG, airway eosinophilia and significant AHR when compared with nonsensitized mice. The genetic deficiency of CD23-/- mice not only failed to prevent but was associated with a significant increase of these responses. These results indicate that CD23 may not be essential for the development of allergen-induced AHR and further, that its presence may have some inhibitory effects on the allergic response.

Rural telemedicine data/image transfer methods and purposes of interactive video sessions

A national survey conducted for the Office of Rural Health Policy in 1995 identified 558 participants in rural telemedicine; 499 (89%) responded to a detailed follow-up survey to describe type of use. While 84% of respondents reported using interactive video, only 25% reported access to e-mail for exchange of data. The challenge to medical informatics is to connect dispersed providers, not just with videoconferencing, but also with other information-sharing methods.

Migration of arterial wall cells. Expression of plasminogen activators and inhibitors in injured rat arteries

The expression of plasminogen activators and inhibitors was examined in denuded arteries. Within 5 days, smooth muscle cells (SMCs) on the luminal surface expressed the mRNA for tissue-type plasminogen activator (TPA), urokinase type plasminogen (UPA), the receptor for UPA (UPAR), and plasminogen activator inhibitor type-1 (PAI-1). Similar results were seen after 8 days. Six weeks later, only TPA mRNA was still expressed by SMCs on the luminal surface. En face casein zymograms revealed a net fibrinolytic activity in areas covered with luminal SMCs. Reverse zymography showed no antifibrinolytic activity in these zones. Quiescent endothelial cells did not express TPA, UPA, UPAR, or PAI-1 mRNA. Regenerating endothelium at the wound edge strongly expressed TPA. UPA, and UPAR, as well as PAI-1. UPA and UPAR expression was highly restricted to cells at the wound edge and was not present elsewhere. En face zymography showed no plasmin activity in endothelialized areas, and reverse zymography showed a net fibrinolytic activity in endothelialized zones. These results suggest that plasminogen activator and inhibitor expression correlates with the migration of both SMCs and endothelial cells into an arterial wound.

Inhibition of matrix metalloproteinase activity inhibits smooth muscle cell migration but not neointimal thickening after arterial injury

Smooth muscle cell (SMC) migration and replication are important for neointimal formation after arterial injury. Migration of SMCs requires degradation of basement membrane and extracellular matrix surrounding the cell, and our previous work has shown a correlation between expression of two matrix-degrading metalloproteinases (MMPs), MMP-2 and MMP-9, and smooth muscle migration into the intima in the balloon catheter-injured rat carotid artery. In the present study, an MMP inhibitor, GM 6001, was administered to rats for various times after balloon injury of the carotid artery. Inhibition of MMP activity resulted in a 97% decrease in the number of SMCs that migrated into the intima by 4 days after injury, and lesions growth was retarded by continuous treatment with GM 6001-treated rats was 0.035 +/- 0.008 mm2 compared with 0.095 +/- mm2 in the control group. Neither intimal nor medical SMC replication rates were decreased by GM 6001 treatment, supporting our hypothesis that the decrease in lesion size was due to inhibition of MMP-mediated migration and not inhibition of replication. By 14 days after injury, however, intimal area and SMC number were the same control and inhibitor-treated rats. An increased rate of SMC replication in the GM 6001 rats (replication rates at 10 days were 56.7 +/- 10.0% in the GM 6001 group and 16.97 +/- 1.73% in the control group) contributed to "catch-up" growth of the neointima. Thus, it appears that inhibiting SMC migration with MMP inhibitors is not sufficient to inhibit lesion growth, and lesion size eventually catches up to control via increased SMC replication.

Pneumomediastinum and pneumoretroperitoneum

A 23-year-old man presented to the emergency department with extensive subcutaneous emphysema and severe dehydration after a prolonged self-imposed religious fast. Chest radiographs showed marked pneumomediastinum and pneumoretroperitoneum without pneumothorax. Patients are often admitted to the hospital for close observation when these findings are recognized, but this caution is generally unwarranted. This case illustrates the common occurrence of the usually benign entity of pneumomediastinum without pneumothorax.

Improved outcome with early blood administration in a near-fatal model of porcine hemorrhagic shock

Current recommendations for the preoperative management of hemorrhagic shock include the initial infusion of 2 L of isotonic crystalloid regardless of the severity of hemorrhage. While this approach may be adequate for patients who experience only mild to moderate hemorrhagic insults, it has never been tested in a clinically relevant model of severe life-threatening hemorrhage. The authors used a porcine model of rapidly fatal hemorrhage with a reproducible and relevant physiologic end-point, the absence of vital signs, to test the hypothesis that even brief delays in blood replacement may result in higher mortality rates and worsen hemodynamic and metabolic responses to hemorrhage. Twenty-four immature swine (11-17 kg) were bled continuously at a decelerating rate until the following criteria were met: (1) respiratory arrest, (2) a pulse pressure of 0 and, (3) a slowing of cardiac electrical activity of 15% or more. Resuscitation was begun 1 minute later. The animals were randomly assigned to one of three resuscitation regimens. Group A (n = 8) received shed blood at a rate of 3 mL/kg/min for 10 minutes followed by normal saline (NS) at a rate of 3 mL/kg/min for 10 minutes. Group B (n = 8) received NS at a rate of 3 mL/kg/min for 10 minutes followed by shed blood at a rate of 3 mL/kg/min for 10 minutes. Group C, controls, (n = 8) received NS at a rate of 3 mL/kg/min for 20 minutes. Animals were observed for 30 minutes after resuscitation or until death. Mortality was 25%, 37.5%, and 100% for groups A, B, and C, respectively (P < .05 for group C versus group A or B).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparability of pulmonary function results from 13 laboratories in a metropolitan area

We have observed that the results of pulmonary function tests obtained at one site, in general, may not be considered 'acceptable' at another site--in part because of known or suspected variability in equipment and techniques. We sought to document the presence or absence of such variability in our metropolitan area.

METHODS & MATERIALS

We compared the test results from 5 trained healthy subjects (3 men and 2 women) studied in 13 Denver-area pulmonary function laboratories in a randomized order and at approximately the same time of day.

RESULTS

We performed analysis of variance on commonly reported parameters and found no significant difference for FVC (p = 0.11), FEV1 (p = 0.075), FEF25-75% (p = 0.41), and FRC by helium dilution (p = 0.22). However, marked differences between certain sites could be clinically important. In addition, we found a statistically significant difference for DLCO (p less than 0.001) and TLC (p = 0.024). Six different brands of pulmonary function equipment were used by the 13 hospitals, and differences in the number of trials performed, sequence of testing (eg, FRC determinations were sometimes done first, sometimes last), and calculation of the DLCO breath-hold time.

CONCLUSION

We conclude that although the FVC, FEV1, FEF25-75%, and FRC measured by helium dilution were not statistically different in healthy trained subjects in the 13 hospitals studied, clinically important differences may exist. The DLCO and TLC were statistically different. To minimize variability and improve comparability, hospitals in a given area should give consideration to adopting standardized techniques, using comparable equipment, and adopting common reference equations.

Distribution of bronchoconstrictor responses in isolated-perfused rat lung

We studied the effects of bronchoconstrictor stimuli administered selectively through isolated-perfused preparations of the bronchial and pulmonary circulations of 80 Sprague-Dawley rats. Dose-related contraction was elicited with infusion of acetylcholine (ACh), histamine, and serotonin (5-HT). Bolus infusion of 10(-5) mol ACh caused a 3.5-fold increase in pulmonary resistance (RL) after infusion into the pulmonary circulation (PC) and a 2.5-fold increase in the bronchial circulation (BC) (P less than 0.05 vs. control) that was blocked selectively in each circulation with atropine. Administration of 10(-5) mol 5-HT into the BC caused only a 45% increase in RL; the same dose of 5-HT caused a 5.1-fold increase in RL in the PC. A biphasic (increase at lower doses/decrease at higher doses) change in RL was elicited by histamine that was converted to dose-related constriction after H2-receptor blockade with cimetidine in both BC and PC. Response to exogenous ACh remained viable for greater than 5 h. Infusion of the mast cell degranulating agent, compound 48/80 (48/80), caused increase in RL that corresponded to quantitative recovery of histamine in the perfusates of both BC and PC. Histamine concentration in the perfusate increased from 47.2 +/- 31.8 (base line) to 624 +/- 60.1 ng/ml (2-fold increase in RL) in the BC and from 38.3 +/- 17.7 (base line) to 294.4 +/- 38.1 ng/ml (50% increase in RL) in the PC (P less than 0.001 vs. baseline concentration) after a 0.1-mg/ml dose of 48/80.(ABSTRACT TRUNCATED AT 250 WORDS)

Determinants of chronic carbon dioxide retention and its correction in humans

17 patients with chronic ventilatory failure (including 14 with chronic obstructive pulmonary disease) were studied to determine the causes of carbon dioxide retention and the chronic effect of medroxyprogesterone acetate on ventilatory drive and acid-base status. Carbon dioxide retention in patients with high mechanical loads occurred concomitantly with a higher than normal inspiratory effort (mouth occlusion pressure) and normal minute ventilation to carbon dioxide production ratio (Ve/Vco(2)); but with shortened inspiratory time (1.3+/-0.1 vs. 1.8+/-3 s), increased breathing frequency (17+/-1 vs. 14+/-1 breaths/min), low tidal volume (0.57+/-0.03 vs. 0.88+/-0.04 L), and high dead space to tidal volume ratio (0.63+/-0.02 vs. 0.39+/-0.07). Using a randomized application of treatment and placebo conditions, it was shown that 4 wk of medroxyprogesterone acetate caused significant reductions in Paco(2) (from 51+/-1 to 42+/-1 mm Hg) in 10 of 17 patients. This "correction" of Paco(2) in these patients was associated with increases in mouth occlusion pressure (14%), tidal volume (11%), and alveolar ventilation (15%) compared to placebo, although inspiratory time remained shortened. Arterial and lumbar cerebrospinal fluid pH was alkaline compared to placebo in patients who "corrected" Paco(2). No change was noted in lung mechanics or core temperature. Common prerequisites for correction of Paco(2) with medroxyprogesterone acetate treatment were the ability to significantly lower Paco(2) upon acute voluntary hyperventilation and to increase tidal volume rather than breathing frequency in response to the drug. We attribute chronic CO(2) retention in these patients to alterations in respiratory cycle timing and to a neuromuscular inspiratory effort which is adequate for the level of tissue CO(2) production, but inadequate in the presence of mechanical and ventilation-perfusion abnormalities to normalize arterial blood gases.