Domain-wall motion in ferromagnetic nanowires driven by arbitrary time-dependent fields: an exact result.

We address the dynamics of magnetic domain walls in ferromagnetic nanowires under the influence of external time-dependent magnetic fields. We report a new exact spatiotemporal solution of the Landau-Lifshitz-Gilbert equation for the case of soft ferromagnetic wires and nanostructures with uniaxial anisotropy. The solution holds for applied fields with arbitrary strength and time dependence. We further extend this solution to applied fields slowly varying in space and to multiple domain walls.

Prehospital needle thoracostomy: What are the indications and is a post-trauma center arrival chest tube required?

OBJECTIVE: This study examined the indications for prehospital needle thoracostomy (pNT), the need for tube thoracostomy (TT) following pNT, and the outcomes of patients who underwent pNT. METHODS: This study is a retrospective chart review of patients who underwent pNT prior to trauma center arrival. Patients were identified from the trauma registry and a quality improvement (QI) database from 9/2014-9/2018. RESULTS: 59 patients underwent 63 pNTs during the time period. The indication for pNT was "hypotension" in only 5 patients (7.9%). A CT chest was obtained on 51 NT attempts with the catheter in place. In 48 (94.1%) NT attempts, the catheter was not in the pleural space. 44 (69.4%) TTs were placed on admission date. CONCLUSION: In patients undergoing pNT, hypotension was rarely the indication. Additionally, CT identified the catheter within the pleural space in only 3 (5.8%) NT attempts. TT placement was performed in 79.3% of NT attempts.

Topology and bistability in liquid crystal devices.

We study nematic liquid crystal configurations in a prototype bistable device -- the post aligned bistable nematic (PABN) cell. Working within the Oseen-Frank continuum model, we describe the liquid crystal configuration by a unit-vector field n , in a model version of the PABN cell. First, we identify four distinct topologies in this geometry. We explicitly construct trial configurations with these topologies which are used as initial conditions for a numerical solver, based on the finite-element method. The morphologies and energetics of the corresponding numerical solutions qualitatively agree with experimental observations and suggest a topological mechanism for bistability in the PABN cell geometry.

A novel functional genomics approach identifies mTERT as a suppressor of fibroblast transformation.

As a tool for functional genomics, a hairpin ribozyme gene library with randomized target recognition sequences was constructed in a retroviral vector. This library has the potential to target and cleave any possible RNA substrate. Mouse fibroblasts transduced with this ribozyme gene vector library were selected in a focus formation assay to isolate in vivo functional ribozymes that promote cell transformation in tissue culture. After two successive rounds of selection by focus formation assay, a transforming ribozyme (Rz007) was identified. The sequence of this ribozyme was used to identify the putative target genes responsible for the transformation. A candidate gene target for Rz007 encodes telomerase reverse transcriptase (mTERT). Both mRNA level and enzymatic activity of mTERT were down-regulated in Rz007-transformed cells. Furthermore, newly designed ribozymes, recognizing other potential ribozyme cleavage sites unique to the mTERT mRNA, also cause cell transformation, thus validating the role of mTERT in suppressing the transformation phenotype. These surprising results suggest that the commonly accepted role of telomerase in maintaining cellular immortalization is more complicated than previously thought. These studies also demonstrate the utility of this novel 'reverse' functional genomics approach, enabling the targeted discovery of genes, whether previously known or not, that are involved in any selectable phenotype.

Somatization and the recognition of depression and anxiety in primary care.

OBJECTIVE: The authors examined the effect of patients' style of clinical presentation on primary care physicians' recognition of depression and anxiety. METHOD: The subjects were 685 patients attending family medicine clinics on self-initiated visits. They completed structured interviews assessing presenting complaints, self-report measures of symptoms and hypochondriacal worry, the Diagnostic Interview Schedule (DIS), and the Center for Epidemiologic Studies Depression Scale (CES-D). Physician recognition was determined by notation of any psychiatric condition in the medical chart over the ensuing 12 months. RESULTS: The authors identified three progressively more persistent forms of somatic presentations, labeled "initial," "facultative," and "true" somatization. Of 215 patients with CES-D scores of 16 or higher, 80% made somatized presentations; of 75 patients with DIS-diagnosed major depression or anxiety disorder, 76% made somatic presentations. Among patients with DIS major depression or anxiety disorder, somatization reduced physician recognition from 77%, for psychosocial presenters, to 22%, for true somatizers. The same pattern was found for patients with high CES-D scores. In logistic regression models education, seriousness of concurrent medical illness, hypochondriacal worry, and number of lifetime medically unexplained symptoms each increased the likelihood of recognition, while somatized presentations decreased the rate of recognition. CONCLUSIONS: While physician recognition of psychiatric distress in primary care varied widely with different criteria for recognition, the same pattern of reduction of recognition with increasing level of somatization was found for all criteria. In contrast, hypochondriacal worry and medically unexplained somatic symptoms increased the rate of recognition.

Somatization and depression in fibromyalgia syndrome.

Psychiatric diagnoses, self-reports of symptoms, and illness behavior of 20 fibromyalgia patients and 23 rheumatoid arthritis patients were compared. The fibromyalgia patients were not significantly more likely than the arthritis patients to report depressive symptoms or to receive a lifetime psychiatric diagnosis of major depression. These results do not support the contention that fibromyalgia is a form of somatized depression. Fibromyalgia patients, however, reported significantly more somatic symptoms of obscure origin and exhibited a pattern of reporting more somatic symptoms, multiple surgical procedures, and help seeking that may reflect a process of somatization rather than a discrete psychiatric disorder.

Purified herpes simplex thymidine kinase Retrovector particles. I. In vitro characterization, in situ transduction efficiency, and histopathological analyses of gene therapy-treated brain tumors.

Replication-defective, highly purified retroviral vectors (Retrovector), at titers of 10(8) colony forming units/mL, were prepared that conferred either beta-galactosidase or herpes simplex thymidine kinase (HSV-TK) activity. 9L gliosarcoma cells, transduced efficiently in vitro, were highly sensitive to ganciclovir (GCV). The mean frequency of in situ transduction, measured by flow cytometry of single-cell tumor suspensions isolated from rat brains, was 3.2 +/- 0.6%; similar assessments were made by staining of beta-galactosidase or by immunohistochemistry with anti-HSV-TK. In vitro HSV-TK-transduced and G418-selected 9L-TK gliosarcoma tumors treated with GCV were eradicated in approximately 53% of the animals (10/19) at day 26, however, 89% (17/19) histologically showed < 1% tumor volume. Histologic evaluation at day 26 of animals with established 9L tumors treated with intralesional injection of HSV-TK vector followed by GCV treatment showed that 29% (4/14) had no tumor; 50% (7/14) had < 1% tumor volume. Regression of tumors proceeded over the time since the complete rate was increased at day 60. Neither HSV-TK vector particles nor GCV alone altered the histological profile of 9L tumors, but substantial numbers of CD4+ and CD8+ lymphocytes infiltrated the tumors of animals treated with both. In cured animals, the former tumor bed contained cell debris, immune cells, and fibroblasts and was without damage to adjacent brain. The efficacy of suicide gene therapy for rat gliosarcoma using highly purified virion vectors approaches that of packaging cell lines.

Phase I trial of interferon-gamma (IFN-gamma) retroviral vector administered intratumorally to patients with metastatic melanoma.

BACKGROUND: Interferon-gamma (IFN-gamma) gene/retroviral vector cell vaccinations have generated protective responses from unmodified tumor cell challenges as well as a regression of established tumors in animal models. The purpose of this trial was to determine the feasibility and safety of a direct intratumoral injection of IFN-gamma retroviral vector in advanced melanoma patients. METHODS: This was a phase I study, in which 13 patients received a single daily injection of a retroviral vector with the IFN-gamma gene for 5 consecutive days (1.5 x 10(8) colony-forming units total dose); patients subsequently underwent resection of the injected lesion to confirm DNA transduction in situ. RESULTS: No toxicity related to the injected vector was observed. Replication competent retrovirus was not observed in any prepared samples (n = 65). IFN-gamma expression was confirmed in 3 of 10 harvested tumor samples; one was equivocal, and DNA transduction was unable to be confirmed by enzyme-linked immunospot assay in six samples. CONCLUSIONS: An injection of IFN-gamma gene/retroviral vector is well tolerated. DNA transduction was demonstrated in human subjects, confirming the feasibility of the direct injection approach for the gene therapy of solid tumors. Further trials to determine optimal schedule and potential efficacy are indicated.

Agreement between older subjects and proxy informants on history of surgery and childbirth.

OBJECTIVES: To assess the agreement between proxy informants' reports of history of surgery and childbirth and older index subjects' own recall. DESIGN: Interrater reliability study. SETTING: An outpatient family medicine clinic and a provincial electoral district in Montreal, Canada. PARTICIPANTS: Eighty-two subjects aged 65 years and older without cognitive impairment, identified from clinic and community settings, and each index subject's proxy respondent. MEASUREMENTS: Identical questionnaires were administered to index subjects and proxies. RESULTS: Proxies failed to report 39% of non-childbirth surgeries reported by index subjects, but failed to report only 10% of childbirths. Female proxies were significantly less likely than male proxies to underreport non-childbirth surgeries after controlling for age of index subject and interval since surgery. Longer interval since surgery was significantly associated with greater underreporting, whereas age of the index subject and relationship between proxy and index subject were not. Agreement between proxies and index subjects on date of surgery was much higher for childbirths than for non-childbirth surgeries. CONCLUSIONS: Our findings suggest that proxy respondents can provide reliable information on older women's history of childbirth but that use of proxy respondents for history of non-childbirth surgeries may result in substantial underreporting.

Inpatient care for uncomplicated bronchiolitis: comparison with Milliman and Robertson guidelines.

CONTEXT: Bronchiolitis is the most common lower respiratory tract infection in infancy. A recent Centers for Disease Control and Prevention report confirmed that hospitalization rates for bronchiolitis have increased 2.4-fold from 1980 to 1996. Controversies exist about optimal treatment plans. Milliman and Robertson recommend ambulatory care management; in case of hospitalization, the recommended length of stay is 1 day. OBJECTIVES: To relate actual practice variation for infants admitted with uncomplicated bronchiolitis to Milliman and Robertson's recommendations. DESIGN: Prospective observational study. SETTING: General care wards of 8 pediatric hospitals of the Child Health Accountability Initiative during the winter of 1998-1999. PATIENTS: First-time admissions for uncomplicated bronchiolitis in patients not previously diagnosed as having asthma and who were younger than 1 year. MAIN OUTCOME MEASURES: Respiratory rate, monitored interventions, attainment of discharge criteria goals, and length of stay. RESULTS: Eight hundred forty-six patients were included in the final analysis: 85.7% were younger than 6 months, 48.5% were nonwhite, and 64.1% were Medicaid recipients or self-pay. On admission to the hospital, 18.3% of the infants had respiratory rates higher than higher than 80 breaths per minute, 53.8% received supplemental oxygen therapy, and 52.6% received intravenous fluids. These proportions decreased to 1.9%, 33.8%, and 20.3%, respectively, 1 day after admission, and to 0.7%, 20.1%, and 8.6%, respectively, 2 days after admission. The average length of stay was 2.8 days (SD, 2.3 days). CONCLUSIONS: Milliman and Robertson's recommendations do not correspond to practice patterns observed at the hospitals participating in this study; no hospital met the Milliman and Robertson recommended 1-day goal length of stay. Administration of monitored intervention persisted past the second day of hospitalization.

A number-needed-to-treat analysis of the use of respiratory syncytial virus immune globulin to prevent hospitalization.

OBJECTIVES: To estimate how many infants in selected high-risk subgroups would require treatment with respiratory syncytial virus immune globulin (RSV-IG) to avoid 1 hospital admission and to determine whether this is economically justified. DESIGN: Cost-benefit analysis. Data from 3 randomized controlled trials of RSV-IG are used to estimate the number needed to treat to prevent 1 hospital admission for respiratory syncytial virus infection. The threshold number needed to treat is computed according to a formula incorporating costs and benefits of RSV-IG prophylaxis. Estimates of the willingness to pay were obtained from a sample of 39 health care providers (35 physicians and 4 nurses). MAIN OUTCOME MEASURES: The number needed to treat to prevent 1 hospital admission for respiratory syncytial virus infection. The threshold number needed to treat that would balance costs with benefits. RESULTS: More than 16 (95% confidence interval, 12.5-23.8) infants would need to be treated with RSV-IG to avoid 1 hospital admission for respiratory syncytial virus infection, ranging from 63 for premature infants without chronic lung disease to 12 (confidence interval, 6.3-100.0) for infants with bronchopulmonary dysplasia. A sensitivity analysis of the costs and values of hospital admission for respiratory syncytial virus infection and RSV-IG treatment resulted in a weak recommendation against the treatment of infants with bronchopulmonary dysplasia and strong recommendations that the costs and risks of RSV-IG treatment outweigh the benefits for the combined sample of infants and premature infants without lung disease. CONCLUSIONS: The number-needed-to-treat procedures offer a method to assess evidence of treatment effects and decision rules for whether to accept treatment recommendations. Under plausible assumptions, treatment with RSV-IG is not recommended for infants without lung disease. Institutions can examine cost and benefit assumptions that best fit their own practice setting.

Measuring outcomes of care for adolescents with emotional and behavioral problems.

OBJECTIVES: To validate the prototype Adolescent Treatment Outcomes Module (ATOM), examine its sensitivity to clinical change, and determine its feasibility for administration in routine clinical settings. METHOD: A sample of 67 adolescents, aged 11 through 18, was selected from new patients at two inpatient and two outpatient mental health programs. Adolescents and parents completed the ATOM and validating instruments at intake, 1 week postintake, and again at 6 months. RESULTS: Nine self-report symptoms predicted positive diagnoses of oppositional defiant, conduct, anxiety, and depressive disorders on the basis of structured diagnoses, with sensitivities of 0.7 to 0.8. Test-retest correlations for outcome scales were largely excellent (>0.70). Scales that measured functioning at home, in school, and in the community were moderately correlated in the expected direction with global functioning. Decreases in symptom severity and functional impairment were generally associated with decreases in validating instruments. Administration time averaged 25 minutes for adolescents and 28 minutes for parents. CONCLUSIONS: Both parents and adolescents readily completed the ATOM. Module scales demonstrated excellent reliability and good to fair concurrent validity. The ATOM was able to detect change and its absence.

Toward a level playing field: predictive factors for the outcomes of mental health treatment for adolescents.

OBJECTIVE: To understand better the effectiveness of routine treatment for emotional and behavioral problems experienced by adolescents, methods are needed to control for between-provider differences in the distribution of factors that adversely affect treatment success. Such methods are necessary to fairly compare providers' outcomes and to aid clinicians in identifying adolescents for whom routine care may need to be altered. As a preliminary step toward developing a model to adjust treatment outcomes to account for predictive factors, findings from studies of treated samples of adolescents were reviewed to identify the factors that influence the likelihood of treatment success for this population. METHOD: Medline and PSYCInfo databases were searched for studies of treated adolescents that reported the association between expert-nominated predictive factors and outcomes. Thirty-four studies met inclusion criteria. RESULTS: Significant predictors identified in these studies include diagnosis, baseline severity of symptoms and functional impairment, family dysfunction, and previous treatment. Several expert-nominated factors have not been adequately studied in treated samples. CONCLUSIONS: Much basic work is needed before a convincing body of empirical evidence can explain predictive factors for adolescent mental health treatment outcomes. Future efforts should determine a reduced set of predictive factors that can be measured with minimal burden to providers.

Excess type 2 diabetes in African-American women and men aged 40-74 and socioeconomic status: evidence from the Third National Health and Nutrition Examination Survey.

OBJECTIVE: To examine whether socioeconomic status (SES) explains differences in the prevalence of type 2 diabetes between African-American and non-Hispanic white women and men. DESIGN: Cross sectional study of diabetes prevalence, SES, and other risk factors ascertained by physical examination and interview. SETTING: Interviews were conducted in subjects' homes; physical examinations were conducted in mobile examination centres. PARTICIPANTS: 961 African-American women, 1641 non-Hispanic white women, 839 African-American men and 1537 non-Hispanic white men, aged 40 to 74 years, examined in the Third National Health and Nutrition Examination Survey (NHANES III), a representative sample of the non-institutionalised civilian population of the United States, 1988-1994. MAIN RESULTS: Among women, African-American race/ethnicity was associated with an age adjusted odds ratio of 1.76 (95% confidence intervals 1.21, 2.57), which was reduced to 1.42 (95% confidence intervals 0.95, 2.13) when poverty income ratio was controlled. Controlling for education or occupational status had minimal effects on this association. When other risk factors were controlled, race/ethnicity was not significantly associated with type 2 diabetes prevalence. Among men, the age adjusted odds ratio associated with African-American race/ethnicity was 1.43 (95% confidence intervals 1.03, 1.99). Controlling for SES variables only modestly affected the odds ratio for African/American race/ethnicity among men, while adjusting for other risk factors increased the racial/ethnic differences. CONCLUSIONS: Economic disadvantage may explain much of the excess prevalence of type 2 diabetes among African-American women, but not among men.

Somatoform disorders: personality and the social matrix of somatic distress.

Personality traits that may contribute to somatization are reviewed. Negative affectivity is associated with high levels of both somatic and emotional distress. Agreeableness and conscientiousness may influence interactions with health care providers that lead to the failure of medical reassurance to reduce distress. Absorption may make individuals more liable to focus attention on symptoms and more vulnerable to suggestions that induce illness anxiety. More proximate influences on the selective amplification of somatic symptoms include repressive style, somatic attributional style, and alexithymia; however, data in support of these factors are scant. Most research on somatoform disorders confounds mechanisms of symptom production with factors that influence help seeking. Longitudinal community studies are needed to explore the interactions of personality with illness experience and the stigmatization of medically unexplained symptoms.

Response to health insurance by previously uninsured rural children.

OBJECTIVE: To examine the healthcare utilization and costs of previously uninsured rural children. DATA SOURCES/STUDY SETTING: Four years of claims data from a school-based health insurance program located in the Mississippi Delta. All children who were not Medicaid-eligible or were uninsured, were eligible for limited benefits under the program. The 1987 National Medical Expenditure Survey (NMES) was used to compare utilization of services. STUDY DESIGN: The study represents a natural experiment in the provision of insurance benefits to a previously uninsured population. Premiums for the claims cost were set with little or no information on expected use of services. Claims from the insurer were used to form a panel data set. Mixed model logistic and linear regressions were estimated to determine the response to insurance for several categories of health services. PRINCIPAL FINDINGS: The use of services increased over time and approached the level of utilization in the NMES. Conditional medical expenditures also increased over time. Actuarial estimates of claims cost greatly exceeded actual claims cost. The provision of a limited medical, dental, and optical benefit package cost approximately $20-$24 per member per month in claims paid. CONCLUSIONS: An important uncertainty in providing health insurance to previously uninsured populations is whether a pent-up demand exists for health services. Evidence of a pent-up demand for medical services was not supported in this study of rural school-age children. States considering partnerships with private insurers to implement the State Children's Health Insurance Program could lower premium costs by assembling basic data on previously uninsured children.

Factors important to students in selecting a residency program.

A 22-item questionnaire, designed to assess the factors students considered important when they ranked residency programs, was distributed to the 1988 senior class of Tulane University School of Medicine just before the submission deadline of the National Residency Matching Program. Completed surveys were obtained from 111 of the 157 graduating students (approximately 71%) and were representative of the entire class in terms of sex, age, race, marital status, and anticipated field of specialization. Results of this investigation suggest that the satisfaction of a program's house officers and the seniors' general impression at the interview were the most important selection factors of the matriculating seniors surveyed. Diversity of the training experience and geographic location were also important selection factors. House officer benefits and salary were low-priority factors in the seniors' program selections.

Treatment for a nondisease: the case of low blood pressure.

This paper documents diagnosis and treatment of hypotension among a sample of subjects visiting blood pressure screening booths as part of a hypertension screening survey in Montreal. Of 1019 subjects, over one quarter had been diagnosed as hypotensive. Though low blood pressure is harmless for the majority of people, almost 10% of the screened sample reported receiving treatment from their physicians for the condition. Treatment typically consisted of harmless, but ineffective placebo-like medications including veal liver extract capsules or injections, iron capsules, tonics and vitamin B12 liquid, injections or capsules. Additional analysis discovered little meaningful difference in systolic and diastolic readings among individuals treated for hypotension, those diagnosed but not treated, and an undiagnosed group. Subjects receiving the hypotensive label from practitioners were typically older women with less education and income. Findings are discussed in light of the overlap between statistical and pathological models of illness; presenting symptoms of patients and their demands for treatment; and assumptions of physicians in diagnostic decision-making. It is speculated that medical definition of a nondisease such as low blood pressure may serve to individualize discomfort when true etiology lies in the environment; legitimate neglect of responsibilities and obligations by assigning one to the sick role; or cause organization of vague impulses into symptoms. Hypotension should be included in utilization studies to determine prevalence of treatment, life history of those being treated and complaints offered for treatment.

Recognizing, treating, and preventing common foot problems.

The incidence, prevalence, and severity of foot conditions increase with age. Teaching patients simple preventive techniques is crucial. Recognition, treatment, and prevention of common foot complaints--i.e., toenail problems, infections, corns and calluses, injuries, flat feet, bunions, arthritis of the toes, and toe and joint deformities--are reviewed.

Podiatric medical considerations in dealing with elder abuse.

The geriatric population is expanding at a rapid rate. With greater numbers of elderly patient visits to the podiatric medical office, the likelihood of difficult psychosocial problems increases. Elder abuse is potentially a serious health risk and the need for the podiatric physician to identify and report elder abuse is a professional and, in many cases, a legal responsibility. The authors identify the signs and symptoms of elder abuse and methods to address this difficult and perplexing problem.