Direct detection of Salmonella from poultry samples by DNA isothermal amplification.

1. Salmonellosis is one of the most important diseases in public health and it is usually associated with poultry product consumption. This study aimed to validate rapid methods to detect Salmonella spp. from poultry samples. 2. A DNA isothermal amplification method, previously developed for other matrices, was applied for the specific detection of Salmonella spp. from various samples, including poultry tissues, drag and boot swabs, faeces and feed. A new procedure was validated with Salmonella spp. serotypes and isolates from other enteric bacterial species, as well as naturally contaminated poultry samples. 3. The study demonstrated the successful development and implementation of a procedure, including a DNA isothermal amplification method, for the detection of Salmonella spp. directly from tissues, drag and boot swabs, faeces and feed. The whole procedure can be performed in less than 24 hours and it has been successfully used in a veterinary diagnostic laboratory.

Speed-dependent modulation of wing muscle recruitment intensity and kinematics in two bat species.

Animals respond to changes in power requirements during locomotion by modulating the intensity of recruitment of their propulsive musculature, but many questions concerning how muscle recruitment varies with speed across modes of locomotion remain unanswered. We measured normalized average burst EMG (aEMG) for pectoralis major and biceps brachii at different flight speeds in two relatively distantly related bat species: the aerial insectivore Eptesicus fuscus, and the primarily fruit-eating Carollia perspicillata These ecologically distinct species employ different flight behaviors but possess similar wing aspect ratio, wing loading and body mass. Because propulsive requirements usually correlate with body size, and aEMG likely reflects force, we hypothesized that these species would deploy similar speed-dependent aEMG modulation. Instead, we found that aEMG was speed independent in E. fuscus and modulated in a U-shaped or linearly increasing relationship with speed in C. perspicillata This interspecific difference may be related to differences in muscle fiber type composition and/or overall patterns of recruitment of the large ensemble of muscles that participate in actuating the highly articulated bat wing. We also found interspecific differences in the speed dependence of 3D wing kinematics: E. fuscus modulates wing flexion during upstroke significantly more than C. perspicillata Overall, we observed two different strategies to increase flight speed: C. perspicillata tends to modulate aEMG, and E. fuscus tends to modulate wing kinematics. These strategies may reflect different requirements for avoiding negative lift and overcoming drag during slow and fast flight, respectively, a subject we suggest merits further study.

Spring or string: does tendon elastic action influence wing muscle mechanics in bat flight?

Tendon springs influence locomotor movements in many terrestrial animals, but their roles in locomotion through fluids as well as in small-bodied mammals are less clear. We measured muscle, tendon and joint mechanics in an elbow extensor of a small fruit bat during ascending flight. At the end of downstroke, the tendon was stretched by elbow flexion as the wing was folded. At the end of upstroke, elastic energy was recovered via tendon recoil and extended the elbow, contributing to unfurling the wing for downstroke. Compared with a hypothetical 'string-like' system lacking series elastic compliance, the tendon spring conferred a 22.5% decrease in muscle fascicle strain magnitude. Our findings demonstrate tendon elastic action in a small flying mammal and expand our understanding of the occurrence and action of series elastic actuator mechanisms in fluid-based locomotion.

Frequency stabilization of an optically pumped far-infrared laser to the harmonic of a microwave synthesizer.

Measurements of the frequency stability of a far-infrared molecular laser have been made by mixing the harmonic of an ultrastable microwave source with a portion of the laser output signal in a terahertz (THz) Schottky diode balanced mixer. A 3 GHz difference-frequency signal was used in a frequency discriminator circuit to lock the laser to the microwave source. Comparisons of the short- and long-term laser frequency stability under free-running and locked conditions show a significant improvement with locking. Short-term frequency jitter was reduced by an order of magnitude, from approximately 40 to 4 kHz, and long-term drift was reduced by more than three orders of magnitude, from approximately 250 kHz to 80 Hz. The results, enabled by the efficient Schottky diode balanced mixer downconverter, demonstrate that ultrastable microwave-based frequency stabilization of THz optically pumped lasers (OPLs) will now be possible at frequencies extending well above 4.0 THz.

Porcine sialoadhesin: a newly identified xenogeneic innate immune receptor.

Extracorporeal porcine liver perfusion is being developed as a bridge to liver allotransplantation for patients with fulminant hepatic failure. This strategy is limited by porcine Kupffer cell destruction of human erythrocytes, mediated by lectin binding of a sialic acid motif in the absence of antibody and complement. Sialoadhesin, a macrophage restricted lectin that binds sialic acid, was originally described as a sheep erythrocyte binding receptor. Given similarities between sialoadhesin and the unidentified macrophage lectin in our model, we hypothesized porcine sialoadhesin contributed to recognition of human erythrocytes. Two additional types of macrophages were identified to bind human erythrocytes-spleen and alveolar. Expression of sialoadhesin was confirmed by immunofluorescence in porcine tissues and by flow cytometry on primary macrophages. A stable transgenic cell line expressing porcine sialoadhesin (pSn CHO) bound human erythrocytes, while a sialoadhesin mutant cell line did not. Porcine macrophage and pSn CHO recognition of human erythrocytes was inhibited approximately 90% by an antiporcine sialoadhesin monoclonal antibody and by human erythrocyte glycoproteins. Furthermore, this binding was substantially reduced by sialidase treatment of erythrocytes. These data support the hypothesis that porcine sialoadhesin is a xenogeneic receptor that mediates porcine macrophage binding of human erythrocytes in a sialic acid-dependent manner.

Strategic planning to reduce medical errors: Part II--therapy.

In Part I of this series, medical errors were analyzed from a systems dynamics viewpoint. It was noted that despite extensive dialogue and a continuing stream of proposed medical practice revisions, medical errors and adverse impacts persist. Connectivity of vital elements is often underestimated or not fully understood. In Part II, our analysis suggests that the most fruitful strategies for dissolving medical errors include facilitating physician learning, educating patients about appropriate expectations surrounding treatment regimens, and creating "systematic" patient protections rather than depending on (nonexistent) perfect providers.

Strategic planning to reduce medical errors: Part I--diagnosis.

Despite extensive dialogue and a continuing stream of proposed medical practice revisions, medical errors and adverse impacts persist. Connectivity of vital elements is often underestimated or not fully understood. This paper analyzes medical errors from a systems dynamics viewpoint (Part I). Our analysis suggests in Part II that the most fruitful strategies for dissolving medical errors include facilitating physician learning, educating patients about appropriate expectations surrounding treatment regimens, and creating "systematic" patient protections rather than depending on (nonexistent) perfect providers.

Would evidence-based regulation improve the practice and management of patient care?

The use of evidence to achieve sound medical diagnoses and optimal treatment plans is considered a standard of practice for healthcare providers. Indeed, failure to do so is prima facie evidence of malpractice. Health and medical care managers have begun espousing a similar philosophy: to make decisions that are data-driven rather than based on logic, intuition, personal preference, or last experience. Unfortunately, regulatory policies and practices in patient care are not always founded upon strong evidence. As a result, unintended consequences often surface after the passage of legislation or the adoption of policies by nongovernmental entities. These dysfunctions might be avoided if policymakers embraced evidence-based protocols commonly found throughout medicine and its management. This paper reviews the dilemmas that unfold when policy is formed without giving sufficient attention, in advance, to "hard" evidence.

Human cytomegalovirus inhibits major histocompatibility complex class II expression by disruption of the Jak/Stat pathway.

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that is able to persist for decades in its host. HCMV has evolved protean countermeasures for anti-HCMV cellular immunity that facilitate establishment of persistence. Recently it has been shown that HCMV inhibits interferon gamma (IFN-gamma)-stimulated MHC class II expression, but the mechanism for this effect is unknown. IFN-gamma signal transduction (Jak/Stat pathway) and class II transactivator (CIITA) are required components for IFN-gamma-stimulated MHC class II expression. In this study, we demonstrate that both a clinical isolate and a laboratory strain of HCMV inhibit inducible MHC class II expression at the cell surface and at RNA level in human endothelial cells and fibroblasts. Moreover, reverse transcriptase polymerase chain reaction and Northern blot analyses demonstrate that neither CIITA nor interferon regulatory factor 1 are upregulated in infected cells. Electrophoretic mobility shift assays reveal a defect in IFN-gamma signal transduction, which was shown by immunoprecipitation to be associated with a striking decrease in Janus kinase 1 (Jak1) levels. Proteasome inhibitor studies with carboxybenzyl-leucyl-leucyl-leucine vinyl sulfone suggest an HCMV-associated enhancement of Jak1 protein degradation. This is the first report of a mechanism for the HCMV-mediated disruption of inducible MHC class II expression and a direct virus-associated alteration in Janus kinase levels. These findings are yet another example of the diverse mechanisms by which HCMV avoids immunosurveillance and establishes persistence.

Overlapping spectra of SMAD4 mutations in juvenile polyposis (JP) and JP-HHT syndrome.

Juvenile polyposis (JP) and hereditary hemorrhagic telangiectasia (HHT) are clinically distinct diseases caused by mutations in SMAD4 and BMPR1A (for JP) and endoglin and ALK1 (for HHT). Recently, a combined syndrome of JP-HHT was described that is also caused by mutations in SMAD4. Although both JP and JP-HHT are caused by SMAD4 mutations, a possible genotype:phenotype correlation was noted as all of the SMAD4 mutations in the JP-HHT patients were clustered in the COOH-terminal MH2 domain of the protein. If valid, this correlation would provide a molecular explanation for the phenotypic differences, as well as a pre-symptomatic diagnostic test to distinguish patients at risk for the overlapping but different clinical features of the disorders. In this study, we collected 19 new JP-HHT patients from which we identified 15 additional SMAD4 mutations. We also reviewed the literature for other reports of JP patients with HHT symptoms with confirmed SMAD4 mutations. Our combined results show that although the SMAD4 mutations in JP-HHT patients do show a tendency to cluster in the MH2 domain, mutations in other parts of the gene also cause the combined syndrome. Thus, any mutation in SMAD4 can cause JP-HHT. Any JP patient with a SMAD4 mutation is, therefore, at risk for the visceral manifestations of HHT and any HHT patient with SMAD4 mutation is at risk for early onset gastrointestinal cancer. In conclusion, a patient who tests positive for any SMAD4 mutation must be considered at risk for the combined syndrome of JP-HHT and monitored accordingly.

The shocking cost of turnover in health care.

Review of turnover costs at a major medical center helps health care managers gain insights about the magnitude and determinants of this managerial challenge and assess the implications for organizational effectiveness. Here, turnover includes hiring, training, and productivity loss costs. Minimum cost of turnover represented a loss of >5 percent of the total annual operating budget. Editor's Note: This article is being reprinted with permission from Health Care Management Review 29(1), 2-7.

Retention of chairs in obstetrics and gynecology: a comparison with other clinical departments.

OBJECTIVE: To compare the retention of chairs in academic obstetrics and gynecology with other core clinical departments. METHODS: Ongoing data were collected from each medical school for the Association of American Medical Colleges Faculty Roster between 1979 and 2007. Primary outcome measures included 5-year and 10-year retention rates and survival curves of first-time chairs. Comparisons were made between first-time chairs in obstetrics and gynecology and other core clinical departments: internal medicine, family medicine, pediatrics, psychiatry, and surgery. RESULTS: Five-year retention rates of obstetrics and gynecology chairs declined from 80% for those who began in 1979-1982 to 53% for those who began in 1998-2002. Ten-year retention in obstetrics and gynecology declined from 54% for those beginning in 1979-1982 to 26% for those beginning in 1993-1997. Other clinical departments experienced more stable 5-year and 10-year retention rates. Although substantially longer than other clinical departments in the 1979-1982 cohort, the median tenure of obstetrics and gynecology chairs who began in 1993-1997 was comparable with or less than that of other clinical departments. Discrete-time survival analysis revealed this decline in obstetrics and gynecology chair retention to be significant (P<.001) and more consistent than in other departments. CONCLUSION: Compared with other core clinical departments, retention of first-time chairs in obstetrics and gynecology declined more consistently from the highest to among the lowest. Chairs were inclined to not remain in office for a prolonged period. LEVEL OF EVIDENCE: II.

Chemical composition of Acid fog.

Fog water collected at three sites in Los Angeles and Bakersfield, California, was found to have higher acidity and higher concentrations of sulfate, nitrate, and ammonium than previously observed in atmospheric water droplets. The pH of the fog water was in the range of 2.2 to 4.0. The dominant processes controlling the fog water chemistry appear to be the condensation and evaporation of water vapor on preexisting aerosol and the scavenging of gas-phase nitric acid.

Learning - the only way to improve health-care outcomes.

Attempts to improve health care have generally failed. Systems analysis urges addressing processes, such as learning, rather than isolated parts of a system. We apply learning curve theory to health care and then explicate the process of learning. Specific recommendations involve how we learn (and unlearn), who should learn, and what should be learned.

Healthcare CEOs and physicians: reaching common ground.

A survey of 670 hospital and health system CEOs was conducted to understand why they chose a career path to CEO, what characteristics typify their career paths, and what major concerns they have about the future. Respondents expressed very strong altruistic reasons for becoming CEO, a finding that is consistent with the rationale many physicians express for entering medical practice. Early CEO career paths were diverse but typically led respondents to a senior managerial position before becoming CEO. Nine percent started as direct providers of healthcare. The respondents' most frequently expressed concerns for the future centered on reimbursement/financing issues and staffing shortages. Physicians may be surprised to learn that healthcare CEOs share their core values, experience similar frustrations, and have identical fears about the future of healthcare. Rather than emphasizing the differences between CEOs and doctors as a stumbling block to alliance, we urge the establishment of a common ground based on similar core values and purposes that will lead to improved communication and the powerful combination of talents derived from collegial collaboration.

Change your metrics: if you get what you measure, then measure what you want--retention.

What we want is retention, not turnover, of our workforce. We should measure what we want-net retention-which is a fundamentally different metric from turnover (not its inverse). Net retention is a highly useful managerial tool, especially for fiscal and strategic planning. Retention enables learning and therefore can facilitate improved medical and organizational outcomes. To retain our workforce and achieve superior results, we must clarify priorities; change our metrics, particularly to long-term outcomes; use evidence-based medicine and evidence-based management; apply the "internal customer" concept; and utilize systems thinking.

Improving medical practice outcomes by retaining clinicians.

Turnover of medical care providers has become so commonplace that callous disregard or weary resignation are prevailing sentiments among remaining staff members when a colleague leaves. This article analyzes reasons for turnover of caregivers and the consequences. Turnover is particularly detrimental in medical practice because it undermines learning, as well as acquisition of judgment and adaptability. Medical practice managers may be unaware of the magnitude of the hidden costs-financial, strategic, and quality-associated with turnover. Strategies are proposed to assist medical care organizations in retaining clinicians and thereby improving healthcare effectiveness and efficiency.

Inhaled Nitric Oxide as a Preoperative Test (INOP Test I): the INOP Test Study Group.

BACKGROUND: This study was performed to determine whether a preoperative hemodynamic evaluation with oxygen and inhaled nitric oxide identifies patients with pulmonary hypertension who are appropriate candidates for corrective cardiac surgery or transplantation more accurately than an evaluation with oxygen alone. METHODS AND RESULTS: At 10 institutions, 124 patients with heart disease and severe pulmonary hypertension underwent cardiac catheterization to determine operability. The ratio of pulmonary and systemic vascular resistance (Rp:Rs) was determined at baseline while breathing approximately 21% to 30% oxygen, and in approximately 100% oxygen and approximately 100% oxygen with 10 to 80 parts per million nitric oxide to evaluate pulmonary vascular reactivity. Surgery was performed in 74 patients. Twelve patients died or developed right heart failure secondary to pulmonary hypertension following surgery. Rp:Rs<0.33 and a 20% decrease in Rp:Rs from baseline were chosen as 2 criteria for operability to determine, in retrospect, the efficacy of preoperative testing in patient selection. In comparison to an evaluation with oxygen alone, sensitivity (64% versus 97%) and accuracy (68% versus 90%) were increased by an evaluation with oxygen and nitric oxide when Rp:Rs<0.33 was used as the criterion for operability. Specificity was only 8% when a 20% decrease in Rp:Rs from baseline was used as the criterion for operability. CONCLUSION: By using a combination of oxygen and inhaled nitric oxide, a greater number of appropriate candidates for corrective cardiac surgery or transplantation can be identified during preoperative testing when a specific value of Rp:Rs is used as a criterion for operability.

Shared coronary arteries and coronary venous drainage in thoracopagus twins.

A pair of type B thoracopagus twins with complex cyanotic heart disease had shared coronary arteries and coronary venous drainage. Surgical separation was not attempted and the twins died at 10.5 months of age. Antemortem angiography demonstrated that Twin A's right coronary artery supplied Twin B's diaphragmatic and anterior ventricular myocardial free wall. A midline communication existed between each twin's right atrium at a common coronary sinus. The crossing coronary artery coursed alongside this connection and was visualized echocardiographically. At postmortem examination, the great cardiac vein of Twin A drained into the orifice of the common coronary sinus on Twin B's side of the midline. In five of six previously reported cases, the children died at attempted separation shortly after ligation of the interatrial communication. This may have been because of occlusion of a coronary artery or acute obstruction of a coronary vein. Consideration of separation of type B thoracopagus twins requires anatomic delineation of the coronary arteries and veins.