25-Hydroxy vitamin D3 serum concentration in dogs with acute polyradiculoneuritis compared to matched controls.

OBJECTIVES: To determine if dogs with acute polyradiculoneuritis have lower serum 25-hydroxy vitamin D3 concentration compared to a control group of dogs with idiopathic epilepsy. MATERIALS AND METHODS: Retrospective case-control study of 21 dogs with acute canine polyradiculoneuritis and 21 control dogs with idiopathic epilepsy matched for year and season of presentation from a referral hospital population in the UK. Serum concentration of 25-hydroxy vitamin D3 was compared between groups using Student's t-test. RESULTS: Dogs with acute canine polyradiculoneuritis had significantly lower (P=0·033) serum 25-hydroxy vitamin D3 concentration (87·1 nmol/L ±55·4 nmol/L) compared to a control group with idiopathic epilepsy (113 nmol/L ±66·3 nmol/L). CLINICAL SIGNIFICANCE: The cause and clinical significance of the altered vitamin D status in dogs with acute polyradiculoneuritis are not clear and require further investigation. Our findings pave the way for improved understanding of acute canine polyradiculoneuritis and, potentially, improved clinical management, if a causal role for 25-hydroxy vitamin D3 is defined.

An exploratory study into factors influencing development of acute canine polyradiculoneuritis in the UK.

OBJECTIVES: To investigate whether the development of acute canine polyradiculoneuritis is associated with various putative risk factors. MATERIALS AND METHODS: Retrospective case-control study with conditional logistic regression analysis from a referral hospital population in the UK where controls were matched for year of presentation. RESULTS: Forty-three cases were identified with acute canine polyradiculoneuritis and 86 controls were selected. Jack Russell terriers and West Highland white terriers were found to have a significantly greater odds of developing acute canine polyradiculoneuritis compared to a mixed baseline group of dogs. The odds of developing acute canine polyradiculoneuritis were greater in the autumn and winter compared to spring. Vaccination, rural/urban habitation, sex, neuter status and age were not associated with development of acute canine polyradiculoneuritis in our population of dogs. CLINICAL SIGNIFICANCE: Breed and season were associated with development of acute canine polyradiculoneuritis. However, this is a small sample and so this observation needs confirmation in further studies and other factors may also be involved. Nevertheless, these findings may be important in further understanding the aetiopathogenesis of this condition.

Prognostic Factors Associated with Recovery of Ambulation and Urinary Continence in Dogs with Acute Lumbosacral Spinal Cord Injury.

BACKGROUND: Limited information is available about prognostic factors for recovery after spinal cord injury (SCI) to the L4-S3 segments. Previous research suggests that L4-S3 SCI does not have a worse prognosis than T3-L3 SCI. HYPOTHESIS/OBJECTIVES: To elucidate prognostic factors for regaining urinary continence and ambulation in dogs with L4-S3 SCI and compare prognosis to T3-L3 SCI. ANIMALS/METHODS: A retrospective study on 61 nonambulatory dogs with L4-S3 SCI, matched to dogs with T3-L3 SCI, compared 3 weeks after onset. Prognostic factors explored using logistic regression and used for matching: nonchondrodystrophic dogs >15 kg versus dogs that were chondrodystrophic or <15 kg; compressive versus noncompressive lesions; presence versus absence of conscious pain perception (CPP); and lower vs upper motor neuron (LMN/UMN) incontinence. RESULTS: Fewer L4-S3 dogs regained continence compared to T3-L3 dogs (64 vs 85%, P = .0033), but no difference existed for regaining ambulation (66 vs 75%, P = .1306). In L4-S3 SCI dogs, fewer dogs regained continence with loss of CPP (P < .001), LMN incontinence (P = .004), and noncompressive lesions (P = .006). Negative prognostic factors for regaining ambulation included absent CPP (P < .001) and large nonchondrodystrophic breed (P = .022). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with L4-S3 SCI have a poorer short-term prognosis than do dogs with T3-L3 SCI. Dogs with L4-S3 SCI had a poor prognosis with loss of CPP, or noncompressive lesions combined with LMN incontinence. Small-breed or chondrodystrophic dogs with retained CPP, compressive lesions, and UMN incontinence had an excellent prognosis. These findings may help guide decision-making in L4-S3 SCI.

Degenerative Encephalopathy in Nova Scotia Duck Tolling Retrievers Presenting with a Rapid Eye Movement Sleep Behavior Disorder.

BACKGROUND: Neurodegenerative diseases are a heterogeneous group of disorders characterized by loss of neurons and are commonly associated with a genetic mutation. HYPOTHESIS/OBJECTIVES: To characterize the clinical and histopathological features of a novel degenerative neurological disease affecting the brain of young adult Nova Scotia Duck Tolling Retrievers (NSDTRs). ANIMALS: Nine, young adult, related NSDTRs were evaluated for neurological dysfunction and rapid eye movement sleep behavior disorder. METHODS: Case series review. RESULTS: Clinical signs of neurological dysfunction began between 2 months and 5 years of age and were progressive in nature. They were characterized by episodes of marked movements during sleep, increased anxiety, noise phobia, and gait abnormalities. Magnetic resonance imaging documented symmetrical, progressively increasing, T2-weighted image intensity, predominantly within the caudate nuclei, consistent with necrosis secondary to gray matter degeneration. Abnormalities were not detected on clinicopathological analysis of blood and cerebrospinal fluid, infectious disease screening or urine metabolite screening in most cases. Postmortem examination of brain tissue identified symmetrical malacia of the caudate nuclei and axonal dystrophy within the brainstem and spinal cord. Genealogical analysis supports an autosomal recessive mode of inheritance. CONCLUSIONS AND CLINICAL IMPORTANCE: A degenerative encephalopathy was identified in young adult NSDTRs consistent with a hereditary disease. The prognosis is guarded due to the progressive nature of the disease, which is minimally responsive to empirical treatment.

Greater ethanol inhibition of presynaptic dopamine release in C57BL/6J than DBA/2J mice: Role of nicotinic acetylcholine receptors.

The mesolimbic dopamine system, originating in the ventral tegmental area (VTA) and projecting to the nucleus accumbens (NAc), has been heavily implicated in the reinforcing effects of ethanol. Recent slice voltammetry studies have shown that ethanol inhibits dopamine release selectively during high-frequency activity that elicits phasic dopamine release shown to be important for learning and reinforcement. Presently, we examined ethanol inhibition of electrically evoked NAc dopamine in two mouse strains with divergent dopamine responses to ethanol, C57BL/6 (C57) and DBA/2J (DBA) mice. Previous electrophysiology and microdialysis studies have demonstrated greater ethanol-induced VTA dopaminergic firing and NAc dopamine elevations in DBA compared to C57 mice. Additionally, DBA mice have greater ethanol responses in dopamine-related behaviors, including hyperlocomotion and conditioned place preference. Currently, we demonstrate greater sensitivity of ethanol inhibition of NAc dopamine signaling in C57 compared to DBA mice. The reduced sensitivity to ethanol inhibition in DBA mice may contribute to the overall greater ethanol-induced dopamine signaling and related behaviors observed in this strain. NAc cholinergic activity is known to potently modulate terminal dopamine release. Additionally, ethanol is known to interact with multiple aspects of nicotinic acetylcholine receptor activity. Therefore, we examined ethanol-mediated inhibition of dopamine release at two ethanol concentrations (80 and 160 mM) during bath application of the non-selective nicotinic receptor antagonist mecamylamine, as well as compounds selective for the ß2-(dihydro-ß-erythroidine hydrobromide; DhßE) and α6-(α-conotoxin MII [H9A; L15A]) subunit-containing receptors. Mecamylamine and DhßE decreased dopamine release and reduced ethanol's inhibitory effects on dopamine in both DBA and C57 mice. Further, α-conotoxin also reduced the dopamine release and the dopamine-inhibiting effects of ethanol at the 80 mM, but not 160 mM, concentration. These data suggest that ethanol is acting in part through nicotinic acetylcholine receptors, or downstream effectors, to reduce dopamine release during high-frequency activity.

The impact of demographic, social, and environmental factors on the development of steroid-responsive meningitis-arteritis (SRMA) in the United Kingdom.

BACKGROUND: Steroid-responsive meningitis-arteritis (SRMA) is an inflammatory disease of dogs that is suspected to be immune-mediated. The development of other immune-mediated diseases has been linked to vaccinations, time of the year, geographic location, sex, neuter status, and breed. HYPOTHESIS/OBJECTIVES: To identify if the development of SRMA is associated with time of year, vaccination, geographic location, sex, neuter status, and breed. ANIMALS: Sixty SRMA cases and 180 controls, all ≤24 months of age and matched for year of presentation, from a referral hospital population in the United Kingdom. METHODS: Retrospective case-control study with unconditional logistic regression analysis. RESULTS: Beagles (P = .001), Border Collies (P = .001), Boxers (P = .032), Jack Russell Terriers (P = .001), Weimaraners (P = .048), and Whippets (P < .001) had significantly greater odds of developing SRMA in this population of dogs. Vaccination, time of year, geographic category, sex, and neuter status did not increase the odds of developing SRMA. CONCLUSIONS AND CLINICAL IMPORTANCE: Only breed increased the odds of developing SRMA. It would be prudent to investigate the genetics of the identified breeds to help elucidate the etiopathogenesis of SRMA.

Screening diagnostics to identify triggers in 21 cases of steroid-responsive meningitis-arteritis.

OBJECTIVES: To evaluate whether screening tests used to identify infectious and neoplastic triggers for immune-mediated haemolytic anaemia, in particular a complete blood count and differential, serum biochemistry profile, urine analysis (including culture), abdominal ultrasound and thoracic radiographs, can identify triggers for steroid-responsive meningitis-arteritis. METHODS: Retrospective descriptive review. RESULTS: Twenty-one steroid-responsive meningitis-arteritis cases were identified in which all screening tests had been performed. All cases had changes in complete blood count (including neutrophilia, monocytosis, lymphocytosis, eosinopenia or anaemia); 19 had changes in biochemistry (including hypoalbuminaemia, hyperglobulinaemia, increased alkaline phosphatase activity, hyperphosphataemia, increased total calcium concentration, hypercholesterolaemia, hyperkalaemia, increased urea concentration and increased alanine aminotransferase activity); two cases had an elevated urine protein to creatinine ratio but none had positive urine culture results; no cases had abnormalities on orthogonal radiographs of the thorax; four cases had abnormalities identified on abdominal ultrasound, which following cytological examination suggested inflammation in the absence of pathological organisms. CLINICAL SIGNIFICANCE: Screening tests used to identify infectious and neoplastic triggers in immune-mediated haemolytic anaemia did not isolate triggers for steroid-responsive meningitis-arteritis in the population of dogs under investigation.

Medical care perceptions in elderly patients with musculoskeletal complaints.

BACKGROUND: Musculoskeletal complaints represent the second most common reason for visits to a physician, second only to the common cold. The limited capability of medical treatment for musculoskeletal disease requires modification of communication with patients by attending to their perception of the disease. OBJECTIVES: To assess patients' satisfaction with care provided by their primary physicians, and the relationship of patients' satisfaction to their expectations of that care, perceptions of physician performance, and perceived severity of musculoskeletal disease. METHODS: Questionnaires were administered to 90 community-dwelling elderly patients (mean age 76 +/- 8 years) presenting for follow-up appointments with their primary care physicians. Patients were asked to report on their satisfaction with the medical care provided by the primary physicians for musculoskeletal symptoms, their expectations of that care, their perceptions of their primary physicians' interaction (regarding competence, performance, and communication), and their perceptions of disease severity (based on the number of areas involved, pain frequency and intensity, and impact on daily activity). The effects on the degree of satisfaction were assessed with regard to demographic variables, co-morbidity, site involved, and response to recommended treatment. RESULTS: Most patients (> 85%) expressed overall satisfaction with their doctor's interpersonal skills. Fewer (76.9%) were satisfied with the amount of effort their doctors spend evaluating their musculoskeletal symptoms, the information received regarding their musculoskeletal symptoms (75%), the degree of pain relief (75%), and the degree of functional improvement (61.8%). Level of education and response to recommended treatment for musculoskeletal disease were the only parameters associated with degree of satisfaction (higher education P = 0.005, lower education P = 0.059, medication P = 0.008, rehabilitation P = 0.076). A high level of expectations (regarding physician's care and musculoskeletal disease treatment) was noted. CONCLUSIONS: The high level of patient satisfaction with their primary physicians' care for musculoskeletal symptoms may reflect the overall tendency of the elderly population to be satisfied with its primary care physicians. However, their high level of expectations (related to perceived efficacy of medical treatment) and their unrealistic perceptions of disease may lead to disappointment and non-compliance with their doctor's recommendations. Management of musculoskeletal disease in the elderly should address the patients' disease perceptions, as well as their therapeutic and functional needs.

Antisense inhibition of Chk2/hCds1 expression attenuates DNA damage-induced S and G2 checkpoints and enhances apoptotic activity in HEK-293 cells.

The cellular response to DNA damage involves checkpoint controls that delay cell cycle progression in order to provide time for repair of damaged DNA. Chk2/hCds1 is a recently identified homolog of the yeast Cds1 kinase that is involved in cell cycle checkpoint response to DNA damage. To investigate the functions of Chk2/hCds1 in response to DNA damage in mammalian cells, we established a stable human kidney embryonic cell line (HEK-293) that expresses antisense Chk2/hCds1 (Chk2AS) under the control of an inducible promoter. Cells that express Chk2AS display defective S-phase delay in response to DNA replication-mediated DNA damage induced by the topoisomerase I inhibitor camptothecin. The defective G2 checkpoint was also observed in Chk2AS cells exposed to the DNA damaging agent VP-16 or gamma-radiation. Enhanced apoptosis was observed in Chk2AS cells after exposure to gamma-radiation or camptothecin. No p53 activation was observed after DNA damage in HEK-293 or Chk2AS cells. Our results indicate that perturbation of Chk2/hCds1 expression adversely affects the S- and G2-phase checkpoints following DNA damage or DNA replication block, and suggest that reduced expression of Chk2/hCds1 might promote a p53-independent apoptotic response.

A program on complementary therapies for long-term care nursing assistants.

Nursing assistants (NAs) receive insufficient support in the face of heavy workloads and challenging job demands. This article describes a course on complementary therapies (CTs) intended to improve NAs' quality of life by helping them plan, develop, implement, and evaluate CTs. Future studies may examine the impact, if any, such courses have on recruitment and retention.

Generalists and oncologists show similar care practices and outcomes for hospitalized late-stage cancer patients. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks for Treatment.

OBJECTIVE: The objective of this work was to identify similarities and differences in primary attending physicians' (generalists' versus oncologists') care practices and outcomes for seriously ill hospitalized patients with malignancy. DESIGN: This was a prospective cohort study (SUPPORT project). SETTING: Subjects were recruited from 5 US teaching hospitals; data were gathered from 1989 to 1994. SUBJECTS: Included in the study was a matched sample of 642 hospitalized patients receiving care for non-small-cell lung cancer, colon cancer metastasized to the liver, or multiorgan system failure associated with malignancy with either a generalist or an oncologist as the primary attending physician. MEASUREMENTS: Care practices and patient outcomes were determined from hospital records. Length of survival was identified with the National Death Index. Physicians' perceptions of patient's prognosis, preference for cardiopulmonary resuscitation (CPR), and length of relationship were assessed by interview. A propensity score for receiving care from an oncologist was constructed. After propensity-based matching of patients, practices and outcomes of oncologists' and generalists' patients were assessed through group comparison techniques. RESULTS: Generalist and oncologist attendings showed comparable care practices, including the number of therapeutic interventions, eg, "rescue care" and chemotherapy, and the number of care topics discussed with patients/ families. Length of stay, discharge to supportive care, readmission, total hospital costs, and survival rates were similar. For both physician groups, perception of patients' wish for CPR was associated with rescue care (P < 0.03), and such care was related to higher hospital costs (P < 0.000). Poorer prognostic estimates predicted aggressiveness-of-care discussions by both types of physicians. Length of the patient-doctor relationship was associated with oncologists' care practices. More documented discussion about aggressiveness of care was related to higher hospital costs and shorter survival for patients in both physician groups (P < 0.001). CONCLUSIONS: Generalists and oncologists showed similar care practices and outcomes for comparable hospitalized late-stage cancer patients. Physicians' perceptions about patients' preferences for CPR and prognosis influenced decision making and outcomes for patients in both physician groups. Length of relationship with patients was associated only with oncologists' care practices. Rescue care increased hospital costs but had no effect on patient survival. Future studies should compare physicians' palliative care as well as acute-care practices in both inpatient and ambulatory care settings. Patients' end-of-life quality and interchange between physician groups should also be documented and compared.

Nurse versus family caregiver perspectives on hospitalized older patients: an exploratory study of agreement at admission and discharge.

Staff nurses and family caregivers of hospitalized elderly patients (> or = age 70) play crucial roles in the health care and recovery of patients. This exploratory study identified and compared nurse and family caregiver perceptions about the patient's health condition, needs to stay healthy, and problems in self-care at admission and discharge. Agreement between nurse and caregiver reports at both time points was assessed. Overall, findings confirmed a lack of agreement between nurses and family caregivers. At both time points, fewer nurses than caregivers focused on disease in describing the patients' health condition, and there was low agreement about diseases when mentioned. Although the great majority of nurses and caregivers reported one or more patient needs to stay healthy, and problems with self-care, there was little agreement about specific needs or problems mentioned at either time point. Findings may be attributed, in part, to current limitations on staff nurses' bedside time or insufficient opportunities, skills, or both to communicate with families about patients as part of comprehensive discharge planning. Organizational factors in large tertiary care hospitals may serve as a deterrent to nurse-family caregiver contact and communication during hospitalization.

Age differences in care practices and outcomes for hospitalized patients with cancer.

OBJECTIVE: To identify age group differences in care practices and outcomes for seriously ill hospitalized patients with malignancy. DESIGN: Prospective cohort study (SUPPORT project). SETTING: Five United States teaching hospitals; data was gathered between 1989 and 1994. SUBJECTS: Nine hundred twenty five older (age > or = 65 years), 983 middle aged (age = 45-64 years), and 274 younger (age = 18-44 years) hospitalized patients receiving care for non-small cell lung cancer, colon cancer metastasized to the liver, or multi-organ system failure associated with malignancy. MEASUREMENTS: Care practices and patient outcomes were determined from hospital records. Length of survival was identified using the National Death Index. After adjusting for important variables, including severity of illness (i.e., SUPPORT model estimate for 2-month survival, cancer condition), hospital site, selection to intervention and sociodemographic variables, age group differences in care practices and outcomes were identified using general linear models. RESULTS: Older patients with cancer had lower resource utilization during hospitalization (P < .04) and were less likely to receive cancer-related treatments (i.e., chemotherapy, platelet infusions, scheduled intravenous medications) than middle-aged and young-adult patients in the first week of hospitalization (P < or = .01). More care topics were discussed with older patients and their families then with younger patients and their families (P < .001). Length of stay and total hospital costs were lower for older and middle-aged patients than for younger patients. Although more older patients had discussions about transfer to hospice (P < .001), older patients were no more likely to be discharged with supportive care (inpatient hospice or home with home/ hospice care). Older patients died sooner than middle-aged patients (P < .01). CONCLUSIONS: Patient age influenced care decisions and outcomes. Older patients (age > or = 65 years) received less aggressive care, had more discussions about care decisions, and died sooner than younger patients with cancer. Younger patients had longer stays, higher hospital costs, and greater probability of rehospitalization. Although well over half of patients died within 6 months of hospitalization, few patients in any age group were discharged with supportive care. Future studies should examine age differences in palliation, as well as acute care of cancer patients across inpatient and ambulatory care settings and should assess quality of care at the end of life.

Experimental determination of phase velocity of perfluorocarbons: applications to targeted contrast agents.

Targeted acoustic contrast agents are designed to enhance the sensitivity and specificity of ultrasonic diagnoses. We have previously developed a ligand targeted ultrasonic contrast system that is a lipid-encapsulated, liquid-perfluorocarbon emulsion. The emulsion particles are small (250 nm) and have inherently low echogenicity unless bound to a surface by a pretargeted ligand through avidin-biotin interactions. We have recently proposed a simple acoustic transmission line model that treats the emulsion particles as a thin layer over the targeted surface. In this model, the acoustic reflectivity of the sample increases for perfluorocarbons with smaller velocities of longitudinal sound or lower densities. In this study, we measure and report the velocity of longitudinal sound for 20 perfluorocarbons using a broadband phase spectroscopic approach for estimating phase velocities. Experimentally determined velocities ranged from 520+/-2 m/sec (perfluorohexane) to 705+/-5 m/s (perfluorodecalin). No measurable dispersion was observed over the useful bandwidth of 2 to 22 MHz. Increasing carbon backbone chain length and fluorine substitution with halogens of greater atomic weight increased the measured speed of sound. Our experimental data were consistent (R=0.87) with a published empirical model that predicts velocity as a function of molecular structure. These data provide a rational basis for optimizing targeted perfluorocarbon-based contrast agents and offer further insight into the physical mechanisms responsible for the observed enhancement of surface acoustic reflectivity.

First radiotherapy of human metastatic brain tumors delivered by a computerized tomography scanner (CTRx).

PURPOSE: This Phase I study was designed to evaluate the computed tomography (CT) scanner as a device for radiation therapy of human brain tumors (CTRx). This first use in humans of a modified CT for treatment was founded on extensive research experience with canine tumors. An additional objective was to increase the therapeutic radiation dose to tumors compared to normal tissue by concentration of infused contrast material in tumors, an effect available at diagnostic x-ray energies but not at megavoltage energies. METHODS AND MATERIALS: A small metastatic brain tumor in each of eight patients received 3-5-weekly fractions of 5 Gy equivalent per fraction from a CT scanner modified to deliver radiation therapy. In each patient, one additional tumor, lying completely outside the volume treated by CTRx, served as a control. The tumor receiving CTRx was treated after infusion of iodinated x-ray contrast media (CM) for dose enhancement. Many of these patients also received conventional 40 Gy whole brain radiation, before, during, or after CTRx treatment. RESULTS: None of the patients showed adverse reactions to the CM or necrosis of the normal brain from the CTRx boost radiation. Monte Carlo calculations of the radiation dose distributions in a model tumor showed that the CTRx irradiation of tumors carrying 10 mg or more of iodine per gram of tumor was as good or better than the dose distribution from conventional 10-MV X-rays. The treated tumor in two of the patients vanished after four treatments, whereas a control tumor in one patient remained constant and grew 4-fold in another patient. CONCLUSION: The CTRx concept effectively combines a modified CT scanner as a diagnostic device, as a simulator dedicated to radiotherapy, and as a treatment machine. Thus, CTRx could be very useful for radiation oncologists in controlling CM-enhanced and other small brain tumors.

Diagnosing dementia: perspectives of primary care physicians.

As few as 50% of dementia cases are diagnosed by physicians. This study investigated how primary care physicians assess patients for dementia and identified barriers to dementia diagnosis in the primary care setting. Seventy-eight physicians in three geographic areas participated in 18 focus groups. Barriers identified included: (a) the failure to recognize and respond to symptoms of dementia; (b) a perceived lack of need to determine a specific diagnosis; (c) limited time; and (d) negative attitudes toward the importance of assessment and diagnosis. These barriers keep physicians from diagnosing dementia and, consequently, from offering concrete help for patients experiencing symptoms of dementia or for the families who care for them.

In vitro characterization of a novel, tissue-targeted ultrasonic contrast system with acoustic microscopy.

Targeted ultrasonic contrast systems are designed to enhance the reflectivity of selected tissues in vivo [Lanza et al., Circulation 94, 3334 (1996)]. In particular, these agents hold promise for the minimally invasive diagnosis and treatment of a wide array of pathologies, most notably tumors, thromboses, and inflamed tissues. In the present study, acoustic microscopy was used to assess the efficacy of a novel, perfluorocarbon based contrast agent to enhance the inherent acoustic reflectivity of biological and synthetic substrates. Data from these experiments were used to postulate a simple model describing the observed enhancements. Frequency averaged reflectivity (30-55 MHz) was shown to increase 7.0 +/- 1.1 dB for nitrocellulose membranes with targeted contrast. Enhancements of 36.0 +/- 2.3 dB and 8.5 +/- 0.9 dB for plasma and whole blood clots, respectively, were measured between 20 and 35 MHz. A proposed acoustic transmission line model predicted the targeted contrast system would increase the acoustic reflectivity of the nitrocellulose membrane, whole blood clot, and fibrin plasma clot by 2.6, 8.0, and 31.8 dB, respectively. These predictions were in reasonable agreement with the experimental results of this paper. In conclusion, acoustic microscopy provides a rapid and sensitive approach for in vitro chracterization, development, and testing of mathematical models of targeted contrast systems. Given the current demand for targeted contrast systems for medical diagnostic and therapeutic use, the use of acoustic microscopy may provide a useful tool in the development of these agents.

Family caregiving of hospitalized patients. Caregiver and nurse perceptions at admission and discharge.

To ensure patients will be discharged to stable, health-promoting home environments, nurses must understand family caregivers' perceptions of the patients' needs and problems in caring for them. At the time patients were admitted to and discharged from the hospital, there was little agreement between family caregivers and nurses about the kinds of things caregivers needed to care for older patients or about problems that might prevent the continuation of caregiving. There was slightly more overall agreement between family care-givers and admission nurses than discharge nurses, despite the fact that discharge nurses reported spending more time with patients and being more knowledgeable about them. Future discharge planning models should build opportunities for nurses to communicate with other health care colleagues who can contribute to a more accurate and complete picture of patients' and family caregivers' needs and problems in the transition from hospital to home.

A proposed microscopic elastic wave theory for ultrasonic backscatter from myocardial tissue.

The physical structures responsible for ultrasonic scattering from myocardial tissue have not yet been conclusively defined. It is hypothesized in this paper that the backscatter from myocardium is primarily due to inhomogeneities approximately the size of the myocytes. In particular, it is proposed that the acoustic contrast responsible for the scattering is that between the extracellular collagen network that surrounds each myocyte (or myocyte bundle) and the rest of the tissue (the myocytes' intracellular contents). To test this hypothesis, a simple elastic wave scattering model for myocardium was developed. An elementary scatterer is modeled as an ellipsoidal shell, having the material properties of wet collagen, imbedded in a host medium having the average properties of myocardium. The first Born approximation to elastic scattering is used to calculate the frequency-dependent scattering from a single scatterer. To scale up from a single scatterer to a distribution of scatterers, it is assumed that the power received at the transducer is simply the sum of the power scattered in the direction of the transducer by each individual scatterer located in the active volume of the beam (an independent-scatterer approximation). Calculations are restricted to the backscattering direction (pulse-echo), although the theory can accommodate pitch-catch scattering at all angles. With the aid of a computer program, the acoustic backscatter coefficient is calculated using the Born formalism and then measurement effects (frequency-dependent beam width and attenuation correction factors) are incorporated to arrive at calculated integrated (frequency-averaged) backscatter. Both the backscatter coefficient and integrated backscatter are calculated for angles of incidence that range from parallel to the long axis of the scatterer to perpendicular to this fiber direction. For the low MHz frequencies typically used in clinical echocardiography, the calculated absolute magnitude of the acoustic backscatter coefficient lies within a range from 0.0001 to 0.001 cm-1 sr-1. For selected fiber geometries, the anisotropy in integrated backscatter as the angle of incidence is varied with respect to the fiber orientation is about 10 dB. The predicted frequency dependence of the acoustic backscatter coefficient is calculated to be about f3.9 in the low MHz frequency range. These calculated results are reasonably consistent with published experimental measurements and provide a successful preliminary test of the hypothesis.

Effect of advanced cardiac life-support training in rural, community hospitals.

OBJECTIVES: To define the effectiveness of training personnel in rural, community hospitals in advanced cardiac life support (ACLS) and the changes that result in the process and quality of care to patients with ischemic heart disease that can be attributed to participation by team members in an ACLS course. DESIGN: Case-controlled, retrospective abstraction of hospital records of 869 consecutive patients with ischemic heart disease, who were admitted during the year preceding and the year following the ACLS course. SETTING: Seven rural, community hospitals in Wisconsin. SUBJECTS: Physicians, nurses, and other critical care staff (others). INTERVENTIONS: Training in ACLS using 12 3-hr sessions in an interdisciplinary format by a multidisciplinary faculty. MEASUREMENTS AND MAIN RESULTS: Rates of successful attainment of the terminal behavior objectives by physicians and nurses were 84.0% and 78.8%, respectively. Less than 50% of others achieved a satisfactory level of competence. Performance on an examination of cognitive ability improved significantly for all groups (p < .005 for nurses; p < .05 for physicians). Enhancement of knowledge base and integrative skills occurred in all areas of designated ACLS content. Difficulty remained apparent relative to the pharmacologic effects of epinephrine and atropine. No statistically significant deterioration in didactic knowledge base could be detected 1 to 2 yrs after completion of the ACLS course. Slight deterioration in intubation and defibrillation skills occurred in < 3 months after completion of the course. Substantial costs were encumbered by the hospitals, despite the free training provided to the institutions. After ACLS training had been given, overall mortality rates decreased from 17.4% to 13.4% (p < .05). A pooled estimate of the decrease in the mortality rate was 1.4 +/- 3.8%/quarter. Across the entire spectrum of severity of illness, the probabilities for survival increased at a given severity of illness following completion of the course (p = .06). When extremes of severity of illness were excluded from the analysis, the differences in probability for survival over the midrange of severity were statistically significant (p < .05). CONCLUSIONS: Training directed to the entire team likely to participate in the provision of ACLS in the community hospital favorably affects the overall practice of ACLS and the survival rate of patients with ischemic heart disease.