Validation of a novel high-sensitivity radioimmunoassay procedure for measurement of total thyroxine concentration in psittacine birds and snakes.

OBJECTIVE: To validate a novel high-sensitivity radioimmunoassay (RIA) procedure developed to accurately measure the relatively low serum total thyroxine (T4) concentrations of birds and reptiles and to establish initial reference ranges forT4 concentration in selected species of psittacine birds and snakes. ANIMALS: 56 healthy nonmolting adult psittacine birds representing 6 species and 42 captive snakes representing 4 species. PROCEDURE: A solid-phase RIA designed to measure free T4 concentrations in dialysates of human serum samples was used without dialysis to evaluate total T4 concentration in treated samples obtained from birds and reptiles. Serum T4 binding components were removed to allow assay of undialyzed samples. Assay validation was assessed by determining recovery of expected amounts of T4 in treated samples that were serially diluted or to which T4 was added. Intra- and interassay coefficient of variation (CV) was determined. RESULTS: Mean recovery of T4 added at 4 concentrations ranged from 84.9 to 115.0% and 95.8 to 119.4% in snakes and birds, respectively. Intra- and interassay CV was 3.8 and 11.3%, respectively. Serum total T4 concentrations for 5 species of birds ranged from 2.02 to 768 nmol/L but ranged from 3.17 to 142 nmol/L for blue-fronted Amazon parrots; concentrations ranged from 0.21 to 6.06 nmol/L for the 4 species of snakes. CONCLUSIONS AND CLINICAL RELEVANCE: This new RIA method provides a commercially available, accurate, and sensitive method for measurement of the relatively low serum T4 concentrations of birds and snakes. Initial ranges for the species evaluated were established.

Beyond health care cost containment: creating collaborative arrangements among the stakeholders.

The causes of escalating healthcare costs in the United States and many other industrial countries are well documented. Less evident are the structural factors that underlie the increases and their implications for the future. This paper discusses these structural factors, puts them in the context of the healthcare marketplace, and proposes a way to address them using a collaborative arrangement among all stakeholders in a healthcare system, called value-based partnering. To be successful, the effort must include not only final purchasers (such as employers or Medicare in the USA) but all stakeholders in a healthcare system. Each stakeholder must develop a value equation in terms that are meaningful to the others, and must identify opportunities for value-enhancing partnerships. The paper also identifies some of the impediments to value-based partnering and discusses ways to overcome them, including the need for senior management intervention within some stakeholder groups, and the importance of collaborative discussions among all stakeholders.

Value-based partnering in health care.

Many companies are beginning to focus on value in their health care purchasing decisions, and some are going beyond value-based purchasing to value-based partnering. Value-based partnering recognizes the interdependencies among stakeholder groups in the health care system and creates a strategic reason for them to exchange information and create long-term strategic alliances. This article discusses the principles of value-based partnering, impediments to practicing it and its future role in the health care system.

Value-based partnering in healthcare: a framework for analysis.

Value-based partnering is designed to move the healthcare system beyond cost-based competition. It recognizes that the healthcare "product" is not a commodity and that much of the value in the system comes from relationships between and among four stakeholders: consumers, providers, health plans, and employers. Given the difficulty of measuring such benefits as quality of care, improved health status, and increased employee productivity, stakeholders within the system traditionally have focused on easily measurable financial considerations such as premium rates. This focus has led to a system that defines relationships in purely financial terms. In contrast, the value-based partnering model presented in this article recognizes the range of factors that stakeholders consider in their relationships with each other. This approach has the potential to change the nature of competition and presents opportunities for those organizations that can effectively partner with other stakeholders and demonstrate value, rather than just lower cost. Moreover, by recognizing the interdependencies among stakeholder groups, the approach creates a strategic reason for employers, health plans, providers, and consumers to exchange information and create long-term alliances.

The extra domain A of fibronectin activates Toll-like receptor 4.

Cellular fibronectin, which contains an alternatively spliced exon encoding type III repeat extra domain A (EDA), is produced in response to tissue injury. Fragments of fibronectin have been implicated in physiological and pathological processes, especially tissue remodeling associated with inflammation. Because EDA-containing fibronectin fragments produce cellular responses similar to those provoked by bacterial lipopolysaccharide (LPS), we examined the ability of recombinant EDA to activate Toll-like receptor 4 (TLR4), the signaling receptor stimulated by LPS. We found that recombinant EDA, but not other recombinant fibronectin domains, activates human TLR4 expressed in a cell type (HEK 293 cells) that normally lacks this Toll-like receptor. EDA stimulation of TLR4 was dependent upon co-expression of MD-2, a TLR4 accessory protein. Unlike LPS, the activity of EDA was heat-sensitive and persisted in the presence of the LPS-binding antibiotic polymyxin B and a potent LPS antagonist, E5564, which completely suppressed LPS activation of TLR4. These observations provided a mechanism by which EDA-containing fibronectin fragments promote expression of genes involved in the inflammatory response.

Cellular events mediated by lipopolysaccharide-stimulated toll-like receptor 4. MD-2 is required for activation of mitogen-activated protein kinases and Elk-1.

Lipopolysaccharide (LPS) stimulates multiple signaling events, including nuclear factor-kappaB (NF-kappaB) activity and the mitogen-activated protein (MAP) kinases, ERK, JNK, and p38 in LPS-responsive cells, resulting in transcriptional activation and cytokine generation. LPS-induced signaling via toll-like receptor 4 (TLR4) results in the activation of the transcription factor NF-kappaB. Since LPS activates other signaling cascades in responsive cells, the objective of this study was to determine whether such events are mediated by TLR4 in response to LPS. We generated human embryonic kidney cells (HEK293) that stably express TLR4 (HEK-TLR4) and examined their responsiveness to LPS by measuring NF-kappaB activity and production of interleukin-8 (IL-8). A trans-reporting system was used to measure the activity of Elk-1, an ETS-domain transcription factor targeted by MAP kinase pathways. LPS stimulated NF-kappaB reporter activity and IL-8 production but not Elk-1 activity in HEK-TLR4 cells. When MD-2, a protein associated with the extracellular domain of TLR4, was expressed in these cells, there was a marked increase in Elk-1 activity as well as ERK, JNK, and p38 MAP kinase phosphorylation in response to LPS. TLR4-mediated NF-kappaB reporter activity and IL-8 production was enhanced by the expression of MD-2. This study demonstrates that expression of both TLR4 and MD-2 is required for LPS to activate or augment the MAP kinase pathways, Elk-1 stimulation, and IL-8 generation.

Aligning physician financial incentives in a mixed-payment environment.

Under a shadow-pricing approach to physician compensation, physicians who deliver healthcare services to a mix of fee-for-service (FFS) and capitated patients are compensated for services via a payment schedule that treats all patients as if they were capitated. By encouraging physicians to adopt the same care-management approach for all patients, shadow pricing helps a group practice prepare for a larger share of revenues to be derived from capitation, thereby making the organization more attractive to many managed care payers. An apparent drawback of shadow pricing is that it gives physicians an incentive to reduce FFS utilization, resulting in a loss of potential revenue to the healthcare organization. This loss can be strategically justified, however, as an investment in the organization's ability to remain viable under capitation and to retain patients for whom payment may shift from FFS to capitation. In developing a shadow-pricing compensation approach, healthcare organizations can include incentives that encourage physicians to meet specific utilization targets, establish review procedures to identify physicians who deviate from the targets, and account for differences in acuity levels among different physicians' patient panels.

Toll-like receptor-4 mediates lipopolysaccharide-induced signal transduction.

TLR4 is a member of the recently identified Toll-like receptor family of proteins and has been putatively identified as Lps, the gene necessary for potent responses to lipopolysaccharide in mammals. In order to determine whether TLR4 is involved in lipopolysaccharide-induced activation of the nuclear factor-kappaB (NF-kappaB) pathway, HEK 293 cells were transiently transfected with human TLR4 cDNA and an NF-kappaB-dependent luciferase reporter plasmid followed by stimulation with lipopolysaccharide/CD14 complexes. The results demonstrate that lipopolysaccharide stimulates NF-kappaB-mediated gene expression in cells transfected with the TLR4 gene in a dose- and time-dependent fashion. Furthermore, E5531, a lipopolysaccharide antagonist, blocked TLR4-mediated transgene activation in a dose-dependent manner (IC50 approximately 30 nM). These data demonstrate that TLR4 is involved in lipopolysaccharide signaling and serves as a cell-surface co-receptor for CD14, leading to lipopolysaccharide-mediated NF-kappaB activation and subsequent cellular events.

Two-part transfer pricing improves IDS financial control.

To help coordinate patient care services across its various provider entities, an integrated delivery system (IDS) must address two financial control matters: design of responsibility centers and selection of an appropriate transfer pricing methodology. Although designating an HMO as a profit center is appropriate, such a designation is inappropriate for an IDS's provider entities. Instead, these entities are more appropriately designated as standard expense centers. Further, an HMO owned and operated by an IDS should purchase patient care from the delivery entities by means of two-part transfer prices, that is, having fixed costs paid for in a lump sum and variable costs paid for on the basis of the actual volume and mix of services provided. The IDS's management must recognize, however, that both case mix and volume lie largely outside a hospital's control and that financial controls should focus on a combination of the hospital's fixed costs and variable costs associated with resources per case, efficiency of resource delivery, and factor prices.

Effect of storage conditions on cortisol, total thyroxine, and free thyroxine concentrations in serum and plasma of dogs.

OBJECTIVE: To determine for dogs stability of cortisol, thyroxine (T4), and free thyroxine (fT4) in plasma and serum stored in glass or plastic tubes at -20, 4, 25, and 37 C. DESIGN: Prospective study. ANIMALS: Phase I, 7 Greyhounds; Phase II, 6 mixed-breed dogs. PROCEDURE: Phase I: blood was obtained after administration of thyroid-stimulating hormone and adrenocorticotropin. Serum and plasma samples from each dog were divided into 8 aliquots, 4 in glass and 4 in plastic tubes. A pair of aliquots, 1 in plastic and 1 in glass, were stored at -20, 4, 25, or 37 C for 5 days and then assayed for hormones. Phase II: blood was obtained without prior stimulation. For fT4 determination, serum from each dog was placed in plastic or glass tubes, assayed immediately, stored at -20 C for 5 days, and reassayed. Aliquots from each dog were also stored for 1 day at 4 or 25 C and then assayed. Samples for cortisol determination were handled as in phase I. RESULTS: Phase I: there was no effect of tube type (glass vs plastic) on cortisol. Cortisol concentrations decreased after storage in serum at 4, 25, and 37 C, and in plasma at 37 C, compared with storage at -20 C. There was no effect of sample type (serum or plasma) on T4. Thyroxine concentrations increased after storage at 37 C in glass, compared with storage at -20 C. The fT4 concentrations were lower in serum than plasma after storage at -20 C. Concentrations of fT4 increased after storage at 37 C in glass, compared with storage at -20 C. Phase II: the fT4 concentrations did not change after storage in any condition. There was no effect of tube type on cortisol concentrations. Serum cortisol concentrations decreased after storage at 37 C, compared with storage at -20 C. CLINICAL IMPLICATIONS: For cortisol, cooling of plasma is not necessary, but serum should be shipped cold. For T4 and fT4, serum is sufficient; contained within plastic tubes, samples can be shipped without cooling if assayed within 5 days.

CNS malformation in a child with Kabuki (Niikawa-Kuroki) syndrome: report and review.

Kabuki (Niikawa-Kuroki) syndrome (KS) comprises characteristic facial changes, developmental delay, skeletal anomalies, mental retardation, and abnormal dermatoglyphics. We report on a 5-year-old Caucasian boy with KS who required surgery for a giant left temporoparietal subarachnoid cyst at age 5 1/2 years. Review of the 143 published cases shows that while malformations may be found in the endocrine, cardiac, genitourinary and skeletal systems, this is the first case of Kabuki syndrome with a major central nervous system malformation.

Simple choristoma of the anterior segment containing brain tissue.

We report an unusual case of a simple choristoma of the anterior segment that contained only brain tissue. The clinical characteristics and findings of pathological examination of this unusual ocular malformation were reviewed. A newborn girl was seen with a fleshy, highly vascular cystic mass arising from the inferior limbus and extending across the cornea. On a computed tomographic scan, gross disruption of the anterior segment was present, with subluxation of the lens into the cyst. Excision of the abnormal tissue was followed by evisceration; polyglactin (Vicryl) ball implantation; patch graft of the globe; and, later, prosthetic fitting. Pathologic findings showed a choristomatous malformation, containing only mature brain tissue. To our knowledge, a choristoma in which the sole constituent is brain tissue has not previously been reported.

Managing clinical integration in integrated delivery systems: a framework for action.

An integrated delivery system (IDS) in healthcare must coordinate patient care across multiple functions, activities, and operating units. To achieve this clinical integration, senior management confronts many challenges. This paper uses a cross-functional-process (CFP) framework to discuss these challenges. There are ten CFPs that fall into three categories: planning processes (strategy formulation, program adaptation, budget formulation), organizational processes (authority and influence, client management, conflict resolution, motivation, and cultural maintenance), and measurement and reporting processes (financial and programmatic). Each process typically spans several functional units. Senior management must consider how to improve both the functioning of each CFP, as well as its "fit" with the other nine. The result can be greater clinical integration, improved cost management, and more coordinated care for enrollees.

Modulation of the Rev-RRE interaction by aromatic heterocyclic compounds.

The HIV-1 Rev protein regulates the nucleocytoplasmic distribution of viral precursor RNAs that encode HIV-1 structural proteins. Rev-mediated viral RNA expression requires a sequence-specific interaction between Rev and a viral RNA sequence, the Rev responsive element (RRE). Because the Rev-RRE interaction is essential for HIV-1 replication, anti-viral agents that selectively block this interaction may be effective anti-HIV-1 therapeutics. Here, we show that certain aromatic heterocyclic compounds, in particular, a tetracationic diphenylfuran, AK.A, can block binding of Rev to its high-affinity viral RNA binding site. AK.A abolishes Rev-RRE interactions at concentrations as low as 0.1 microM. Inhibition appears to be selective and results from competitive binding of the drug to a discrete region within the Rev binding site. Interestingly, the molecular basis for the AK.A-RNA interaction, as well as the mode of RNA binding differs from previously described aminoglycoside Rev inhibitors. Analysis of a variety of aromatic heterocyclic compounds and their derivatives reveals stereo-specific features required for the inhibition. Our results further demonstrate the feasibility of identifying and designing small molecules that selectively block viral RNA-protein interactions.

Clinical diagnosis of ocular sarcoidosis.

PURPOSE: To assess the value of raised serum angiotensin converting enzyme (ACE) levels in making a clinical diagnosis of ocular sarcoidosis in patients with intraocular inflammation, compatible with sarcoidosis, in whom tissue biopsy is either not practical or not possible. METHODS: The ocular manifestations and clinical course of 22 patients with intraocular inflammation compatible with sarcoidosis and elevated ACE level (including 11 patients with abnormal chest radiograph) were compared with those of a group of 18 patients with intraocular inflammation due to biopsy-proven sarcoidosis. The mean follow-up (+/- SD) was 4.5 +/- 3.4 years in the presumed ocular sarcoidosis group and 7.8 +/- 5.3 years in the biopsy-proven sarcoidosis group. RESULTS: There was no difference in sex, race and age distribution between the two groups. No statistically significant difference could be found between the ocular manifestations seen in each group. The most common finding was retinal vasculitis with panuveitis, seen in 86.4% of the presumed ocular sarcoidosis group and in 83.3% of the biopsy-proven sarcoidosis group. CONCLUSIONS: These results suggest that intraocular inflammation compatible with sarcoidosis in conjunction with raised ACE levels would be accordant with a diagnosis of sarcoidosis in patients in whom histological diagnosis is either not practical or not possible.

Distinctive Menkes disease variant with occipital horns: delineation of natural history and clinical phenotype.

To delineate further the clinical spectrum of Menkes disease, an X-linked recessive disorder of copper transport, we studied 4 related males, ranging in age from 4-38 years, with a unique phenotype that combines manifestations of classical and mild Menkes disease and occipital horn syndrome (OHS). The propositus, and 18-year-old man, was evaluated following an intracerebral hemorrhage at age 15 years and was noted to have marked hypotonia, motor delay with mental retardation, bladder diverticula, failure to thrive, and diarrhea from infancy; seizures from age 3 years; and abnormal hair (pili torti) and face, cutis laxa, and multiple joint dislocations. Radiographic abnormalities included occipital exostoses, tortuous cerebral blood vessels with multiple branch occlusions, and hammer-shaped clavicles. Biochemical studies demonstrated reduced copper and ceruloplasmin levels in serum, and abnormal plasma catecholamine ratios. We reported previously the molecular defect in this family, a splice-site mutation that predicts formation of approximately 20% of the normal Menkes gene product [Kaler et al., 1994: Nat Genet 18:195-202]. Here, we detail the clinical course and physical features and radiographic findings in these 4 individuals, and compare their phenotype with classical and mild Menkes and OHS. Unusual Menkes disease variants such as this may escape recognition due to anomalies that appear inconsistent with the diagnosis, particularly prolonged survival and later onset of seizures. Males with mental retardation and connective tissue abnormalities should be evaluated for biochemical evidence of defective copper transport.