Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

A 2-4 keV multilayer mirrored channel for the NIF Dante system

During inertial confinement fusion experiments at the National Ignition Facility (NIF), a capsule filled with deuterium and tritium (DT) gas, surrounded by a DT ice layer and a high-density carbon ablator, is driven to the temperature and densities required to initiate fusion. In the indirect method, 2 MJ of NIF laser light heats the inside of a gold hohlraum to a radiation temperature of 300 eV; thermal x rays from the hohlraum interior couple to the capsule and create a central hotspot at tens of millions degrees Kelvin and a density of 100-200 g/cm³. During the laser interaction with the gold wall, m-band x rays are produced at ∼2.5 keV; these can penetrate into the capsule and preheat the ablator and DT fuel. Preheat can impact instability growth rates in the ablation front and at the fuel-ablator interface. Monitoring the hohlraum x-ray spectrum throughout the implosion is, therefore, critical; for this purpose, a Multilayer Mirror (MLM) with flat response in the 2-4 keV range has been installed in the NIF 37° Dante calorimeter. Precision engineering and x-ray calibration of components mean the channel will report 2-4 keV spectral power with an uncertainty of ±8.7%.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

How Do Health Systems Address Patient Flow When Services Are Misaligned With Population Needs? A Qualitative Study

BACKGROUND

Patient flow through health services is increasingly recognized as a system issue, yet the flow literature has focused overwhelmingly on localized interventions, with limited examination of system-level causes or remedies. Research suggests that intractable flow problems may reflect a basic misalignment between service offerings and population needs, requiring fundamental system redesign. However, little is known about health systems' approaches to population-capacity misalignment, and guidance for system redesign remains underdeveloped.

METHODS

This qualitative study, part of a broader investigation of patient flow in urban Western Canada, explored health-system strategies to address or prevent population-capacity misalignment. We conducted in-depth interviews with a purposive sample of managers in 10 jurisdictions across 4 provinces (N = 300), spanning all healthcare sectors and levels of management. We used the constant comparative method to develop an understanding of relevant strategies and derive principles for system design.

RESULTS

All regions showed evidence of pervasive population-capacity misalignment. The most superficial level of response - mutual accommodation (case-by-case problem solving) - was most prevalent; capacity (re)allocation occurred less frequently; population redefinition most rarely. Participants' insights yielded a general principle: Define populations on the basis of clusters of co-occurring need. However, defining such clusters demands a difficult balance between narrowness/rigidity and breadth/flexibility. Deeper analysis suggested a further principle: Populations that can be divided into homogeneous subgroups experiencing similar needs (eg, surgical patients) are best served by narrow/ rigid models; heterogeneous populations featuring diverse constellations of need (eg, frail older adults) require broad/ flexible models.

CONCLUSION

To remedy population-capacity misalignment, health system planners should determine whether clusters of population need are separable vs. fused, select an appropriate service model for each population, allocate sufficient capacity, and only then promote mutual accommodation to address exceptions. Overreliance on case-by-case solutions to systemic problems ensures the persistence of population-capacity misalignment.

Uncertain in the face of change: Lack of contingency shift awareness during extinction is associated with higher fear-potentiated startle and PTSD symptoms in children

Intolerance of uncertainty is a transdiagnostic risk factor for fear-related disorders and is associated with higher levels of anxiety in children and adolescents. It is unclear how uncertainty relates to development of psychopathology in children who have experienced trauma in early life. The present study used a fear-potentiated startle paradigm in children to examine associations between uncertainty (assessed as unawareness of a change in reinforcement during fear extinction) and symptoms of anxiety and posttraumatic stress disorder (PTSD), as well as startle potentiation to threat and safety cues. Results showed that unaware children had strong positive associations between trauma exposure and PTSD symptoms, whereas aware children did not. Uncertainty interacted with anxiety in that children who were both unaware and had higher anxiety displayed higher fear-potentiated startle to safety cues and did not show discrimination between threat and safety during fear conditioning. These results suggest that anxious children who persist in associating a threat cue with an aversive event during extinction, after repeated presentations of the no longer reinforced conditioned stimulus, may express psychophysiological phenotypes related to PTSD.

The "hard, relentless, never-ending" work of focusing on discharge: a qualitative study of managers' perspectives

PURPOSE

Interventions to hasten patient discharge continue to proliferate despite evidence that they may be achieving diminishing returns. To better understand what such interventions can be expected to accomplish, the authors aim to critically examine their underlying program theory.

DESIGN/METHODOLOGY/APPROACH

Within a broader study on patient flow, spanning 10 jurisdictions across Western Canada, the authors conducted in-depth interviews with 300 senior, middle and frontline managers; 174 discussed discharge initiatives. Using thematic analysis informed by a Realistic Evaluation lens, the authors identified the mechanisms by which discharge activities were believed to produce their impacts and the strategies and context factors necessary to trigger the intended mechanisms.

FINDINGS

Managers' accounts suggested a common program theory that applied to a wide variety of discharge initiatives. The chief mechanism was inculcation of a sharp focus on discharge; reinforcing mechanisms included development of shared understanding and a sense of accountability. Participants reported that these mechanisms were difficult to produce and sustain, requiring continual active management and repeated (re)introduction of interventions. This reflected a context in which providers, already overwhelmed with competing demands, were unlikely to be able (or perhaps even willing) to sustain a focus on this particular aspect of care.

ORIGINALITY/VALUE

The finding that "discharge focus" emerged as the core mechanism of discharge interventions helps to explain why such initiatives may be achieving limited benefit. There is a need for interventions that promote timely discharge without relying on this highly problematic mechanism.

Can facility-based transitional care improve patient flow? Lessons from four Canadian regions

Units providing transitional, subacute, or restorative care represent a common intervention to facilitate patient flow and improve outcomes for lower acuity (often older) inpatients; however, little is known about Canadian health systems' experiences with such "transition units." This comparative case study of diverse units in four health regions (48 interviews) identified important success factors and pitfalls. A fundamental requirement for success is to clearly define the unit's intended population and design the model around its needs. Planners must also ensure that the unit be resourced and staffed to deliver truly restorative care. Finally, streamlined processes must be developed to help patients access and move through the unit. Units that were perceived as more effective appeared to have satisfactorily addressed these population, capacity, and process issues, whereas those perceived as less effective continued to struggle with them. Findings suggest principles to support optimal design and implementation of transition units.

"Working Against Gravity": The Uphill Task of Overcapacity Management

While most health systems have implemented interventions to manage situations in which patient demand exceeds capacity, little is known about the long-term sustainability or effectiveness of such interventions. A large multi-jurisdictional study on patient flow in Western Canada provided the opportunity to explore experiences with overcapacity management strategies across 10 diverse health regions. Four categories of interventions were employed by all or most regions: overcapacity protocols, alternative locations for emergency patients, locations for discharge-ready inpatients, and meetings to guide redistribution of patients. Two mechanisms undergirded successful interventions: providing a capacity buffer and promoting action by inpatient units by increasing staff accountability and/or solidarity. Participants reported that interventions demanded significant time and resources and the ongoing active involvement of middle and senior management. Furthermore, although most participants characterized overcapacity management practices as effective, this effectiveness was almost universally experienced as temporary. Many regions described a context of chronic overcapacity, which persisted despite continued intervention. Processes designed to manage short-term surges in demand cannot rectify a long-term mismatch between capacity and demand; solutions at the level of system redesign are needed.

Population trends in emergency cancer diagnoses: The role of changing patient case-mix

BACKGROUND

Diagnosis of cancer through an emergency presentation is associated with worse clinical and patient experience outcomes. The proportion of patients with cancer who are diagnosed through emergency presentations has consequently been introduced as a routine cancer surveillance measure in England. Welcome reductions in this metric have been reported over more than a decade but whether reductions reflect true changes in how patients are diagnosed rather than the changing case-mix of incident cohorts in unknown.

METHODS

We analysed 'Routes to Diagnosis' data on cancer patients (2006-2015) and used logistic regression modelling to determine the contribution of changes in four case-mix variables (sex, age, deprivation, cancer site) to time-trends in emergency presentations.

RESULTS

Between 2006 and 2015 there was an absolute 4.7 percentage point reduction in emergency presentations (23.8%-19.2%). Changing distributions of the four case-mix variables explained 19.0% of this reduction, leaving 81.0% unexplained. Changes in cancer site case-mix alone explained 16.0% of the total reduction.

CONCLUSION

Changes in case-mix (particularly that of cancer sites) account for about a fifth of the overall reduction in emergency presentations. This would support the use of adjustment/standardisation of reported statistics to support their interpretation and help appreciate the influence of case-mix, particularly regarding cancer sites with changing incidence. However, most of the reduction in emergency presentations remains unaccounted for, and likely reflects genuine changes during the study period in how patients were being diagnosed.

Assessment of a rapid liquid-based cytology method for measuring sputum cell counts

Differential sputum cell counting is not widely available despite proven clinical utility in the management of asthma. We compared eosinophil counts obtained using liquid-based cytology (LBC), a routine histopathological processing method, and the current standard method. Eosinophil counts obtained using LBC were a strong predictor of sputum eosinophilia (≥3%) determined by the standard method suggesting LBC could be used in the management of asthma.

Interprofessional collaboration in mental health crisis response systems: a scoping review

Post deinstitutionalization saw the rise of mental health crisis (MHC) response in Canada. First points of contact for individuals in a MHC are often police services or emergency departments. Professionals in these areas may report feeling unprepared, ill equipped, and a lack of confidence to work with clients in crisis. Police indicate that this work is time consuming, demanding, and "not their job". Entry points can exacerbate the crisis given the chaotic, over-stimulating and frightening environment of emergency departments and the perceived threat of police officers. Despite the outcry of support for working more collaboratively, little is known about the impact Interprofessional collaboration (IPC) has in mental health crisis response systems (MHCRS).

PURPOSE

Given this challenge, the aim of this scoping review is to contribute to understanding the current state of knowledge related to IPC in MHCRS.

METHODS

A scoping reviews was conducted to address the research topic.

RESULTS

Review of the literature identified 18 articles for inclusion, 5 experimental or exploratory papers, 7 models of care, and 6 discussion papers. Analysis identified the following themes: Support for interprofessional collaboration, quest for improved care delivery system, merging distinct visions of care, and challenges to interprofessional collaboration. Implications for practice, policy, and research are discussed, as well as issues in the literature related to: Lack of conceptual clarity, absent client perspectives, unequal representation across sectors, and a young and emergent body of literature.

CONCLUSION

Key concepts need better conceptualization, and further empirical research is needed.

IMPLICATIONS FOR REHABILITATION

Conceptualizing mental health crisis (MHC) response as occurring within a system of services, rather than independent sectors, is critical to meeting the needs of clients. Purposefully built in mechanisms to sustain collaboration across care teams and services are required. Merging the distinct, and at times conflicting, visions of care espoused by the diverse sectors involved in MHC response requires deliberate effort.

The influence of corporate structure and quality improvement activities on outcome improvement in residential care homes

OBJECTIVE

To examine the impact of corporate structure and quality improvement (QI) activities on improvements in client-reported and professional indicators between 2007 and 2009.

DESIGN

A cross-sectional study using organizational survey and indicator multilevel modelling to test relationships between corporate structure, QI activities and performance improvements on indicators.

SETTING

In total, 169 residential care homes for the elderly in the Netherlands.

MAIN OUTCOME MEASURES

Change between 2007 and 2009 in client-reported and professional indicators.

RESULTS

A middle-size corporate structure was associated with QI. The QI activity 'multidisciplinary team meetings' was positively correlated with the indicator 'safety environment' for somatic and psycho-geriatric care. The QI activities 'educational material' and 'direct work instructions' were associated negatively with the indicator 'availability of personnel' for somatic clients, but positively for psycho-geriatric clients. QI activities such as 'health plan activities', 'clinical lessons' and 'financial activities' had no relationship to improved performance. For psycho-geriatric clients mainly organizational QI activities were positively associated with QI. The mediating role of the corporate structure for performing QI activities appeared stronger for the change in client-reported than for professional indicators.

CONCLUSION

This study reveals associations between QI activities and corporate structure and changes in indicator performance. A corporate structure was associated with improvement in client-reported indicators, but less on professional indicators, which assumes a central policy at corporate level with impact on client-reported indicators, in contrast to a more local level approach towards activities that result in QI on professional indicators. Tailoring QI activities at the right managerial level may be important to achieve improvement.

Technical challenges of hepatic venous outflow reconstruction in right lobe adult living donor liver transplantation

A right lobe graft that is drained by the right hepatic vein (RHV) is obtained by transecting the liver on the right side of the middle hepatic vein (MHV). On occasion, a small RHV that only drains a portion of the right lobe, with the predominant outflow achieved by the MHV, is encountered. If such variation is not recognized while performing right lobe liver transplantation and the RHV only is used for reconstruction, venous outflow obstruction with subsequent graft congestion and eventual graft failure will occur. Additionally, preservation of the main MHV and its branch drainage of the left lobe is crucial to avoid outflow blockage to the remaining segment 4 in the donor. We report 4 cases showing a variant type of small RHV and large MHV branch that drain not only segments 5 and 8, but also segments 6 and 7. These variations were simultaneously associated with a large-caliber inferior RHV that also required reconstruction. The methods used to diagnose such anatomic variations and the techniques for reconstruction in the donor and recipient are described.

Characterization of 3-[(123)I]iodo-L-alpha-methyl tyrosine transport in astrocytes of neonatal rats

3-[(123)I]Iodo-L-alpha-methyl tyrosine ((123)I-IMT) is used for diagnosis and monitoring of brain tumours by means of single-photon emission tomography. As recently shown, (123)I-IMT is predominantly mediated into rat C6 glioma cells by sodium-independent system L for large neutral amino acids. Until now, (123)I-IMT transport in non-neoplastic glial cells has not been examined. Therefore, the aim of this study was to examine the cellular pathways and precise transport kinetics of (123)I-IMT uptake into astrocytes of neonatal rats. In particular sodium-independent (123)I-IMT transport into neonatal astrocytes was compared with sodium-independent (123)I-IMT uptake into neoplastic rat C6 glioma cells. Competitive inhibition experiments showed that (123)I-IMT is exclusively transported via sodium-independent system L into the neonatal astrocytes (92%). Kinetic analysis of sodium-independent (123)I-IMT uptake into neonatal astrocytes and into C6 glioma cells revealed apparent Michaelis constants K(M) = 13.9 +/- 0.5 microM and K(M) = 33.9 +/- 4.1 microM, respectively, which are in the same range of K(M) values as those recently determined for amino acid transport into neoplastic and non-neoplastic glial cells. Indeed, the K(M) values in the micromolar range correspond to the expression of the LAT-1 subunit of system L both in the neonatal astrocytes and in C6 glioma cells. However, sodium-independent maximum transport velocities (V(max)) differed significantly between neonatal astrocytes and C6 glioma cells (11.1 +/- 0.3 and 39.9 +/- 3.3 nmol/mg protein/10 min, respectively).

Electromagnetic fields (1.8 GHz) increase the permeability to sucrose of the blood-brain barrier in vitro

We report an investigation on the influence of high frequency electromagnetic fields (EMF) on the permeability of an in vitro model of the blood-brain barrier (BBB). Our model was a co-culture consisting of rat astrocytes and porcine brain capillary endothelial cells (BCEC). Samples were characterized morphologically by scanning electron microscopy and immunocytochemistry. The BBB phenotype of the BCEC was shown by the presence of zona occludens protein (ZO-1) as a marker for tight junctions and the close contact of the cells together with the absence of intercellular clefts. Permeability measurements using (14)C-sucrose indicated a physiological tightness which correlated with the morphological findings and verified the usefulness of our in vitro model. Samples were exposed to EMF conforming to the GSM1800-standard used in mobile telephones (1.8 GHz). The permeability of the samples was monitored over four days and compared with results of samples that were cultured identically but not exposed to EMF. Exposure to EMF increased permeability for (14)C-sucrose significantly compared to unexposed samples. The underlying pathophysiological mechanism remains to be investigated.

Vascular disease risk markers in diabetes: monitoring & intervention

Identifying and treating risk markers for vascular disease in diabetes is significant in preventing long-term disabilities and containing health care costs. Current research recommends maintaining normal blood glucose levels in all diabetes patients. Blood glucose that is elevated for several years is a major factor in the development and progression of microvascular diabetes complications. Patients play a key role in monitoring vascular disease risk markers. This article provides information on the risk markers to monitor, microvascular and macrovascular complications, and current therapies to combat complication progression.

Repair of five distal radius fractures with an investigational cancellous bone cement: a preliminary report

OBJECTIVE

The purpose of the study was to evaluate the feasibility of Norian SRS bone cement injected percutaneously into a distal radius following reduction in both preventing loss of reduction as well as safety.

DESIGN

The study was a prospective clinical study with an established protocol.

SETTING

The study was conducted at the Massachusetts General Hospital following approval of the institutions Investigational Review Board. All patients were required to read and approve an informed consent document.

PATIENTS

While twenty patients' radiographs fulfilled the requirement of a dorsally displaced extraarticular fracture to have occurred within 72 hours of presentation, only five consented to participate fully and one voluntarily withdrew after a six-month follow-up.

INTERVENTION

All fractures were reduced under regional or general anesthesia, and the Norian SRS was introduced via a catheter system into the metaphyseal defect of the fracture. A short arm cast was applied and remained in place for six weeks.

MAIN OUTCOME MEASUREMENTS

Radiographic parameters of fracture reduction were measured prospectively by an independent radiologist throughout the 12 months of the study. Clinical parameters of hand and wrist function were measured prospectively by an independent occupational therapist.

RESULTS

At 12-month follow-up, radial length was a mean 9.9 mm with an average loss of < 1 mm; radial angle maintained at a mean 25.4 degrees; volar angle was within normal range (0-21 degrees) in 4; and 1 patient had a dorsal angle of 7 degrees. Wrist motion improved 50 percent between 6 weeks and 3 months and improved further by 12 months when grip strength reached a mean of 88 percent of the contralateral side. Dorsal and volar extrusion of injected Norian SRS in 4 patients resorbed over time. There were no clinically significant adverse effects or complications.

CONCLUSIONS

Norian SRS proved to be clinically safe and effective as a cancellous bone cement to maintain fracture reduction of unstable extraarticular distal radius fractures.

Early identification of patients with native valve infectious endocarditis at risk for major complications by initial clinical presentation and baseline echocardiography

Early identification of a high risk patient subgroup with infective endocarditis which develops a major complication (emboli, congestive heart failure, surgery for valve replacement, or death) during hospitalization would reduce morbidity, mortality and cost. Thus, for 74 patients with native valve infective endocarditis with documented vegetation by transthoracic two-dimensional echocardiogram, we reviewed 67 variables: history (15), physical examination (9), hematology/miscellaneous (7), chest X-ray (2), electrocardiogram (4), transthoracic two-dimensional echocardiograms (15) and hospital course (15). There were 48 men and 26 women, ages 45 +/- 19 years: 35 intravenous drug abusers and 39 non-users. There were 32 mitral, 21 tricuspid, 20 aortic, and 1 pulmonic valve vegetations; mean vegetation size was 1.4 +/- 0.9 cm2. Over the course of their hospitalization, 14 patients died (19%), 27 developed congestive heart failure (36%), 27 had systemic emboli (36%), and 22 required surgery (30%). The incidence of complications (death, heart failure or embolic events) did not differ between the drug abusers and non-users. Initial complaint of dyspnea on admission predicted the subsequent development of heart failure (P < 0.001), and a pre-admission embolus predicted a second in-hospital embolus (P < 0.001). Left atrial size, ventricular systolic or diastolic dimension did not effect prognosis. Importantly, a vegetation > 1.8 cm2 was 100% specific but only 30% sensitive for predicting the development of a complication. Vegetation mobility, shape, and number of cusps involved were not predictive. However, aortic valve vegetations had significantly more complications than those on the mitral valve (P < 0.03). By discriminant function analysis, 87% of major complications were predicted with the patient profile of having aortic valve vegetation, dyspnea on admission, prolonged preadmission fever, and no history of drug abuse; 75% of patients who developed heart failure were predicted by their having aortic valve vegetation, dyspnea, hypotension (systolic < 90 mm Hg), and no history of drug abuse; and 77% of patients requiring surgery were predicted by their having larger vegetation size, rales, and leftward shift of white blood cells. Thus, in native valve bacterial endocarditis with transthoracic echocardiographic documented vegetations, non-drug abusers with aortic vegetations, preadmission prolonged fevers, dyspnea, emboli and larger sized vegetations are at high risk for developing a major complication during their hospitalization.

Patterns of Cryptosporidium antigen and oocyst excretion in calves studied by reverse passive haemagglutination and light microscopy

A reverse passive haemagglutination (RPH) assay incorporating a monoclonal antibody against Cryptosporidium parvum oocysts was used to follow Cryptosporidium coproantigen excretion by calves. RPH detected soluble antigen that passed 0.22 micron filters. Non-specific reactions that occurred in some samples were markedly reduced by heat treatment of the faecal specimens and were abolished by filtration after heat treatment. Results were compared with oocyst counts performed by microscopy of modified Ziehl-Neelsen (MZN) stained faecal smears. Five hundred and thirty-two daily specimens were examined from 30 calves. The mean age at which positive results for both oocysts and antigen was detected was 9 days (range 5-15 days), and excretion lasted for 5-11 days with some cycling of positive reactions in some calves. The occasional cycling to a negative reaction demonstrates a need to take samples from consecutive days to ensure diagnosis. Two hundred and ninety-one (54.7%) specimens were negative in both tests, 178 (33.5%) were positive in both, 14 (2.6%) were positive only by microscopy, and 49 (9.2%) were positive only by RPH. By these criteria the kappa coefficient of agreement between the tests was good (0.753). Compared with MZN, the sensitivity of RPH is 92.7%, specificity 85.6%, positive predictive value 78.4% and negative predictive value 95.4%. The method is simple, objective, has ease of quality control, and either single samples or batches can be processed.

Cryptosporidium antigen detection in human feces by reverse passive hemagglutination assay

A reverse passive hemagglutination (RPH) assay was developed for Cryptosporidium oocyst antigen with an antioocyst monoclonal antibody (MAb; MAb-C1) coupled to stabilized sheep erythrocytes. RPH was compared with microscopy of auramine-phenol-stained smears of 56 oocyst-positive fecal samples, each of which was tested blindly by RPH with two oocyst-negative samples received on the same day (a total of 112 controls). Thirty-nine additional fecal samples from human immunodeficiency virus type 1 antibody-positive patients with diarrhea (10 of which were positive in auramine-phenol-stained smears) were stored at -20 degrees C before testing. Thirty specimens with a variety of other fecal pathogens (all negative for oocysts) were also tested. Of the 237 samples tested, 69 were positive by one or both methods: 65 by RPH and 66 by microscopy. The kappa coefficient of agreement between the methods was very high at 0.926. The sensitivity of RPH was 93.9%, the specificity was 98.2%, the positive predictive value was 95.4%, and the negative predictive value was 97.7%. Visible oocyst numbers and RPH titers were measured after storage of fecal samples and oocyst concentrates for 8 days at 4 degrees C. Oocyst morphology was generally poor in specimens from the human immunodeficiency virus type 1 antibody-positive group, and it degenerated during the 8-day storage experiments. MAb-C1-reactive antigen eluted from oocysts to give progressively higher reciprocal titers during storage, and it was partially removed from the oocysts by concentration. RPH is a promising technique for the detection of Cryptosporidium antigen in human feces and may be useful when specimens are stored before testing. Studies of the sensitivity of Cryptosporidium immunoassays should take into account the possible release of antigen from oocysts.

Home blood glucose monitoring: effectiveness in a general population of patients who have non-insulin-dependent diabetes mellitus

OBJECTIVE

To determine whether home blood glucose monitoring as used by non-insulin-dependent diabetes mellitus patients followed in primary care nonresearch clinics improves glycemic control or reduces utilization of the outpatient laboratory.

DESIGN

A retrospective chart review for 229 patients receiving outpatient supplies for home testing of either blood or urine.

SETTING

A variety of nonresearch clinics at a Veterans Affairs Medical Center, a teaching hospital affiliated with an academic university medical center.

PATIENTS

Outpatient veterans followed in diabetes, primary care, internal medicine, or endocrine clinics.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The mean glycosylated hemoglobin for an unselected group monitoring glycemic control by urine testing only was 11.32% and for those using blood monitoring was 11.37%. Frequency and duration of monitoring had no apparent impact on glucose control. There was no decrease in the utilization of the laboratory among those patients practicing home blood glucose monitoring.

CONCLUSIONS

For non-insulin-dependent diabetic patients followed in a nonresearch clinic setting, the benefits of home blood glucose monitoring remain to be proven.

Effect of thyroxine on urinary bladder autonomic receptor densities and contractility

The effect of thyroxine on the response of urinary bladder strips to autonomic drugs and electrical stimulation was studied. Bladder strips from euthyroid, hyperthyroid and thyroidectomized rats were used. Rats were made hyperthyroid by intramuscular injection of thyroxine (250 micrograms/rat for 5 days). Surgical thyroidectomy was performed 12-15 weeks before the experiment. The contractile response of bladder strips from each of the 3 groups of rats to electrical field stimulation and the following drugs was measured: isoproterenol; bethanechol; methoxamine; adenosine triphosphate, and potassium chloride. Isoproterenol produced a significantly greater relaxation in strips from hyperthyroid than from euthyroid rats. The enhanced relaxation response to isoproterenol was accompanied by an increase in beta-adrenergic receptor density. The contractile response to methoxamine, adenosine triphosphate and potassium chloride was unchanged by pretreating the rats with thyroxine. The increase in contraction produced by bethanechol was the same in strips from hyperthyroid and euthyroid rats and the muscarinic receptor densities were also unaltered by thyroxine. Bladder strips from thyroidectomized rats showed the same response as strips from control animals following electrical field stimulation or exposure to isoproterenol, bethanechol, methoxamine, adenosine triphosphate and potassium chloride. These results demonstrate that thyroxine pretreatment enhances the relaxation of urinary bladder strips produced by isoproterenol and that this response is correlated with a hormone-induced increase in beta-adrenergic receptors in this tissue.

Streptococci from primary isolation plates grouped by reverse passive haemagglutination

Reverse passive haemagglutination, a novel microtitre based assay, was compared with the Streptex (Wellcome UK) latex slide agglutination kit for streptococcal grouping in a diagnostic microbiology laboratory. Three hundred and fifty two extracts from 349 consecutive primary isolation plates were assayed by both methods. Reverse passive haemagglutination gave identical grouping results for 98.0% of the 345 streptococci identified by Streptex, and the kappa coefficient of agreement between the methods for all 352 extracts tested was 0.973. Cross reactions with Listeria spp seen with Streptex were not found by reverse passive haemagglutination. In the reverse passive haemagglutination method 11 streptococci could be grouped on each 96-well plate and most reactions were stable for at least 30 minutes. Reverse passive haemagglutination is more rapid to perform than latex slide agglutination when many organisms are to be grouped, and the patterns of haemagglutination are easily recognised. If the method was taken into routine use in a diagnostic laboratory, the persistence of reverse passive haemagglutination reactions would enable grouping results to be checked for quality control purposes.

Dyslipidemia in veterans. Multiple risk factors may break the bank

The National Cholesterol Education Program guidelines for treatment of high cholesterol levels especially target patients who have multiple risk factors for coronary heart disease. Veterans have an increased prevalence of smoking, are predominantly male, and may have higher rates of other risk factors than other groups; therefore, they may require more aggressive screening and treatment for dyslipidemias. To assess the prevalence of cardiac risk factors, current cholesterol screening practices, and the potential impact of the National Cholesterol Education Program guidelines on the Veterans Affairs health care system, we reviewed 185 randomly selected charts of outpatients who were actively receiving follow-up at the Denver (Colo) Veterans Affairs Medical Center. The patients had an average age of 58.3 years and 99.5% were male. Of these patients, 60% had a serum cholesterol level checked within the last 999 days. Nearly all patients (84%) had two or more risk factors noted. The mean cholesterol level was 5.85 mmol/L (226 mg/dL), with 72% of patients having levels above 5.20 mmol/L (200 mg/dL) and 36.1% having levels above 6.20 mmol/L (240 mg/dL). Of patients who had their cholesterol level checked, 69% (77/111) would require lipoprotein analysis by National Cholesterol Education Program guidelines (cholesterol, greater than or equal to 6.20 mmol/L [greater than or equal to 240 mg/dL] or 5.15 to 6.20 mmol/L [200 to 239 mg/dL] with two or more risk factors), yet only 16% (12/77) had lipoprotein analyses done. Extrapolating from these data, the Denver Veteran Affairs Medical Center, which cares for 28,000 patients, has more than 19,000 patients who would need lipoprotein analysis to meet current guidelines. Full evaluation and subsequent treatment of dyslipidemias in veterans would require tremendous financial and manpower commitments.

Frequency and significance of occult late potentials on the signal-averaged electrocardiogram in sustained ventricular tachycardia after healing of acute myocardial infarction

The quantitative and morphologic characteristics and significance of late potentials on the signal-averaged electrocardiographic QRS complex remain unknown. To assess this, the signal-averaged electrocardiogram of 48 patients (mean age +/- standard deviation 62 +/- 9 years) with sustained ventricular tachycardia (VT) after healing of acute myocardial infarction and late potentials were analyzed. Late potentials could be classified into 3 morphologic subtypes: type I late potentials (19 patients, 40%) occurred in the terminal 40 ms of the QRS complex; type II late potentials (16 patients, 33%) started before the end of the QRS complex and extended 30 +/- 17 ms into the ST segment; type III late potentials (13 patients, 27%) started after the end of the QRS complex in the ST segment and ended 67 +/- 27 ms after the end of the QRS complex. The amplitude of the late potentials in type III, when compared with types I and II, was significantly lower, whereas the QRS duration on the electrocardiogram in type I, when compared with types II and III, was significantly longer. Computer algorithm based on noise failed to identify most type III late potentials. No difference was noted in age, sex, site of the myocardial infarction, and rate of induced VT among the 3 types.(ABSTRACT TRUNCATED AT 250 WORDS)

The patient's position influences the incidence of dysrhythmias during pulmonary artery catheterization

To determine the influence of a patient's position on the incidence of dysrhythmias during pulmonary artery catheterization, 34 adult patients scheduled for elective coronary artery bypass graft surgery and pulmonary artery catheterization were studied. All introducers were inserted via the right internal jugular vein using the Seldinger technique with the patient in the Trendelenburg position. For each patient, the pulmonary artery catheter was advanced twice: once while the patient was in the Trendelenburg (T) position with a 5-10 degrees head-down tilt and another with a 5 degrees head-up and right lateral tilt (R) position. In 13 of the 68 pulmonary artery catheter passages, no dysrhythmias were noted. In 13 patients, a change in dysrhythmia classification was noted between the two positions. In 11 of the 13 patients, the dysrhythmia classification changed from malignant in the Trendelenburg position to benign or absent in the right lateral tilt position. Although the incidence of dysrhythmias was similar in both groups, the Trendelenburg position was associated with a significantly higher incidence of malignant dysrhythmias than the right tilt position (P less than 0.05). The authors conclude that the head-up and right lateral tilt position appears superior to the Trendelenburg position for passage of the pulmonary artery catheter in the awake patient scheduled for elective coronary bypass surgery.

A nurse-managed multiple sclerosis clinic: improved quality of life for persons with MS

Multiple sclerosis (MS) is a complex disease, the symptoms of which may wax and wane on a daily basis. Conventional treatment for MS patients may involve numerous trips to a variety of clinics, physicians, and rehabilitation settings. This article describes a nurse-managed MS clinic which employs an interdisciplinary and holistic approach to treatment of MS patients with the goal of improving their quality of life and coordinating their health care. In this article, the services of the clinic are described, emphasizing the roles of the nurse practitioner (clinic manager), rehabilitation nurse specialist, and nursing director of the hospital-based home care program. A case study example of the interdisciplinary nature of this clinic's program with one MS patient is included.

Occult aspiration of a nut in an elderly patient: a case report

Occult foreign body aspiration is an uncommon but serious occurrence in the elderly population. A case is presented in which the foreign body, a nut, was uncovered only at autopsy.

Psychological differentiation and socioeconomic status

Two studies were performed to evaluate the hypothesis that field dependence and related cognitive abilities do not differ with socioeconomic status. 6 subtests of the WISC (3 verbal and 3 performance) were administered to middle- and lower-class boys, together with a measure of field dependence (Embedded figures) and a measure of sophistication-of-body concept. Two adult male groups (middle and lower class) were given the Embedded-figures test. The hypothesis was substantially supported for both adult and child samples. Only on Block Design, a test which correlates highly with measures of field dependence, did performance differ significantly by social class. The patterning of cognitive abilities was highly similar for middle- and lower-class boys, with Block Design providing the only serious discrepancy.