Testing of a Novel Method for Securing Ligaments Against Bone During Simultaneous Medial and Lateral Elbow Ligament Reconstruction.

PURPOSE: A ligament reconstruction method that simultaneously tensions the medial and lateral sides of the elbow and maintains tension with compression plates on the proximal ulna is proposed for the treatment of bidirectional elbow ligament instability. Graft slippage, catastrophic failure, and excessive displacement were evaluated. Biomechanical stability without graft slippage was hypothesized. METHODS: Eight cadaveric ligament reconstruction simulations were created through the dissection of three cadaver arms. Each reconstruction was statically tested with 160 N in a manner where it was first augmented with an absorbable suture and then without. Then, 3 more ligament reconstruction simulations were created for dynamic testing with each undergoing testing at 80 N for 2,000 cycles at 2 Hz. Construct displacement and graft slippage were recorded for each load application. RESULTS: No grafts failed catastrophically and no graft slippage was observed with either static or dynamic loading. Under static loading, the mean change in displacement between augmented and nonaugmented ligament reconstruction simulations was 28.7% ± 21% (augmented 3.95 ± 1.81 mm vs nonaugmented 4.89 ± 2.22 mm). The mean stiffness was 66.6 ± 26.6 N/mm for augmented and 64.6 ± 23.2 N/mm for nonaugmented simulations. With dynamic loading, the mean displacement for augmented graft ligament reconstruction simulations was 1.55 ± 0.16 mm compared with 2.18 ± 0.77 mm for nonaugmented reconstruction simulations. CONCLUSIONS: This method of fixation to the proximal ulna for the simultaneous reconstruction of medial and lateral elbow ligaments successfully prevented graft slippage without excessive construct displacement during static and dynamic testing. Ligament augmentation with absorbable sutures decreased the construct displacement. CLINICAL RELEVANCE: This ligament fixation method may be a viable alternative for the treatment of concomitant medial and lateral elbow instability.

Testing of Novel Total Elbow Prostheses Using Active Motion Experimental Setup.

PURPOSE: The goal of this study was to test a novel uncemented and unconstrained total elbow arthroplasty (Kaufmann total elbow) design that is stabilized through a ligament reconstruction. METHODS: We quantified the implant stability after 25,000 cycles, which represents the time between implantation and when ligament and bone healing has occurred. We used an active motion experimental setup that applies tendon loads via pneumatic cylinders and reproduces the forearm-originating dynamic stabilizers of the elbow. The novel total elbow arthroplasty was actuated for 5,000 full flexion-extension cycles at 5 different shoulder positions. Four Sawbones and 4 cadaver elbows were employed. Angular laxity and implant stability were recorded prior to testing and after each 5,000-loading cycle. RESULTS: Four Sawbones and 4 cadaver elbows were implanted with the uncemented total elbow arthroplasty and did not demonstrate fixation failure or substantial laxity after 25,000 cycles of loading imparted at different shoulder positions. CONCLUSIONS: Our findings demonstrate that the Kaufmann total elbow replacement implanted into cadaver and Sawbones specimens did not exhibit fixation failure or excessive laxity after 25,000 cycles. CLINICAL RELEVANCE: An uncemented, nonmechanically linked total elbow arthroplasty that gains component fixation using intramedullary screws and employs a ligament reconstruction to stabilize the elbow has the potential to be a valuable management option, particularly in younger patients.

Decomposition of Phenolic Impregnated Carbon Ablator (PICA) as a Function of Temperature and Heating Rate.

Material response models for phenolic-based thermal protection systems (TPSs) for atmospheric entry are limited by the lack of knowledge of the nonequilibrium processes that may govern the decomposition pathways of phenolic resin at heating rates up to tens of degrees Celsius per second. We have investigated the pyrolysis of phenolic impregnated carbon ablator (PICA) by measuring the molar yields of the volatile decomposition products as a function of temperature at four nominal heating rates of 3.1, 6.1, 12.7, and 25 °C s-1, over the temperature range of 100-1200 °C. A mass spectrometer was used to probe the 14 significant gaseous products directly as PICA samples were heated resistively in vacuum. Four products, H2, CH4, H2O, and CO, overwhelmingly dominated the molar yields. However, in terms of mass yield, phenol and its methylated derivatives, cresol and dimethyl phenol, were significant. The temperature-dependent molar yields of the observed products exhibited a marked dependence on heating rate. The heating-rate-dependent behavior of the molar yields has been attributed to two main competing decomposition processes that occur as the temperature passes from roughly 300 to 500 °C: (1) cross-linking reactions that produce ether functional groups and carbon-carbon bonds and eliminate H2O and (2) breakdown of the polymer backbone through scission of methylene bridges and liberation of phenol and its methylated derivatives. The latter process competes more effectively with the former as the heating rate increases. The relative rates of these processes appear to have a significant effect on the molar yields of volatile products from subsequent decomposition processes as the temperature is increased further. Thus, the heating rate strongly affects the pathways taken during the pyrolysis of the phenolic resin in PICA. The new data may be used to test nonequilibrium models that are designed to simulate the response of TPS materials during atmospheric entry of spacecraft.

Pyrolysis of phenolic impregnated carbon ablator (PICA).

Molar yields of the pyrolysis products of thermal protection systems (TPSs) are needed in order to improve high fidelity material response models. The volatile chemical species evolved during the pyrolysis of a TPS composite, phenolic impregnated carbon ablator (PICA), have been probed in situ by mass spectrometry in the temperature range 100 to 935 °C. The relative molar yields of the desorbing species as a function of temperature were derived by fitting the mass spectra, and the observed trends are interpreted in light of the results of earlier mechanistic studies on the pyrolysis of phenolic resins. The temperature-dependent product evolution was consistent with earlier descriptions of three stages of pyrolysis, with each stage corresponding to a temperature range. The two main products observed were H2O and CO, with their maximum yields occurring at ∼350 °C and ∼450 °C, respectively. Other significant products were CH4, CO2, and phenol and its methylated derivatives; these products tended to desorb concurrently with H2O and CO, over the range from about 200 to 600 °C. H2 is presumed to be the main product, especially at the highest pyrolysis temperatures used, but the relative molar yield of H2 was not quantified. The observation of a much higher yield of CO than CH4 suggests the presence of significant hydroxyl group substitution on phenol prior to the synthesis of the phenolic resin used in PICA. The detection of CH4 in combination with the methylated derivatives of phenol suggests that the phenol also has some degree of methyl substitution. The methodology developed is suitable for real-time measurements of PICA pyrolysis and should lend itself well to the validation of nonequilibrium models whose aim is to simulate the response of TPS materials during atmospheric entry of spacecraft.

Dehydroepiandrosterone replacement in addison's disease.

Addison's disease is a rare endocrine disorder which can be life-threatening. It can also interfere with the normal development of adrenarche, resulting in the absence of pubic and axillary hair growth. We report a case of satisfactory restoration of adrenarche through DHEA administered in conjunction with the standard glucocortisone and fluorocortisone replacement.

Maternal smoking cessation and relapse prevention during health care visits.

BACKGROUND: Although effects of maternal smoking during pregnancy could be alleviated if women quit early in pregnancy, most do not. Relapse rates among quitters are high. OBJECTIVE: To test the effects of a low-intensity, smoking-cessation/relapse-prevention intervention delivered by clinic staff and providers and based on stages-of-change constructs of the transtheoretical model and brief motivational interviewing techniques. METHODS: A quasi-experimental prospective cohort design employed in obstetric, in-patient, and pediatric care delivery settings of a large health maintenance organization in Portland, Oregon. Subjects were pregnant smokers registered for their first prenatal visit. Primary outcome measures were sustained (self-reported) quit rates during pregnancy and smoking abstinence between 6 and 12 months after delivery. RESULTS: Regression analyses found statistically significant improvement for intervention women in sustained pregnancy quit rates (OR=2.7, CI=1. 2-5.7) and on smoking abstinence between 6 and 12 months after delivery (OR=2.4, CI=1.1-5.3). CONCLUSIONS: While these outcomes are based on self-report only, they emerged despite variable delivery of the intervention across clinics and represent clinically meaningful improvements in rates of nonsmoking. The intervention supports women who want to quit smoking during pregnancy and improves the likelihood of their remaining nonsmokers for the long term.

Inhibition of human immunodeficiency virus replication and growth advantage of CD4+ T cells and monocytes derived from CD34+ cells transduced with an intracellular antibody directed against human immunodeficiency virus type 1 Tat.

Current clinical gene therapy protocols for the treatment of human immunodeficiency virus type 1 (HIV-1) infection involve the ex vivo transduction and expansion of CD4+ T cells derived from HIV-positive patients at a late stage in their disease (CD4+ cell count <400 cells/mm3). We examined the efficiency of transduction and transgene expression in adult bone marrow (BM)- and umbilical cord blood (UCB)-derived CD34+ cells induced to differentiate into T cells and monocytes in vitro with an MuLV-based vector encoding the neomycin resistance gene and an intracellular antibody directed against the Tat protein of HIV-1 (sFvtat1-Ckappa). The expression of the marker gene and the effects of antiviral construct on subsequent challenge with monocytotropic and T cell-tropic HIV-1 isolates were monitored in vitro in purified T cells and monocytes generated in culture from the transduced CD34+ cells. Transduction efficiencies of CD34+ cells ranged between 22 and 27%. Differentiation of CD34+ cells into T cells or monocytes was not significantly altered by the transduction process. HIV-1 replication in monocytes and CD4+ T cells derived from CD34+ cells transduced with the intracellular antibody gene was significantly reduced in comparison with the degree of HIV replication seen in monocytes and CD4+ T cells derived from CD34+ cells transduced with the neomycin resistance gene alone. Further, T cells and monocytes derived from CD34+ cells transduced with the intracellular antibody gene were demonstrated to express the sFvtat1-Ckappa transgene by RT-PCR and had a selective growth advantage in cultures that had been challenged with HIV-1. These data demonstrate that sFvtat1-Ckappa inhibits HIV-1 replication in T cells and monocytes developing from CD34+ cells and supports the continuing development of a stem cell gene therapy for the treatment of HIV-1 infection.

A clinical trial of retroviral-mediated transfer of a rev-responsive element decoy gene into CD34(+) cells from the bone marrow of human immunodeficiency virus-1-infected children.

Genetic modification of hematopoietic stem cells with genes that inhibit replication of human immunodeficiency virus-1 (HIV-1) could lead to development of T lymphocytes and monocytic cells resistant to HIV-1 infection after transplantation. We performed a clinical trial to evaluate the safety and feasibility of this procedure, using bone marrow from four HIV-1-infected pediatric subjects (ages 8 to 17 years). We obtained bone marrow, isolated CD34(+) cells, performed in vitro transduction with a retroviral vector carrying a rev-responsive element (RRE) decoy gene, and reinfused the cells into these subjects with no evidence of adverse effects. The levels of gene-containing leukocytes in peripheral blood samples in the 1 year after gene transfer/cell infusion have been extremely low. These observations support the potential of performing gene therapy for HIV-1 using hematopoietic cells, but emphasize the need for improved gene transfer techniques.

Beta-blockers and depression: the more the murkier?

OBJECTIVE: To review the literature regarding the purported association between oral ingestion of beta-blocker drugs and depressed mood. DATA SOURCE: MEDLINE was searched for published articles using the key words propranolol, atenolol, metoprolol, nadolol, timolol, beta-blocker, beta-adrenergic antagonist, or beta-adrenergic blocker in combination with the key words depression, depressive symptomatology, major depressive disorder, or depressed mood from January 1966 through December 1996. DATA SYNTHESIS: Findings regarding the association are equivocal. Plausible explanations include study design, case definition, and confounding disease states. Most of the evidence supporting an association has used case series and case reports. Findings from cross-sectional observational studies and case-control studies are equivocal. Case definition and measurement instruments may partially explain these inconsistencies. Studies using a diagnosis of depression generally do not support the relationship. Trials using depressive symptoms are about evenly split, but they have generally enrolled a small number of patients and have questionable statistical power. Studies defining antidepressant prescriptions dispensed as a marker for depression generally support the association. Evidence exists both for and against the hypothesis that lipophilic beta-blockers cause more depression than do hydrophilic beta-blockers. CONCLUSIONS: beta-Blockers may have been unjustly associated with depression and their use avoided for that reason. Future studies into the association between depression and beta-blocker use should evaluate whether the association is affected by case definition and study design characteristics, including disease, dose-response, bias, measurement error, or ability to precisely measure the length of the exposure.

Inducing amenorrhea during bone marrow transplantation. A pilot study of leuprolide acetate.

OBJECTIVE: To evaluate, in a pilot study, the use and efficacy of a gonadotropin-releasing hormone (GnRH)-agonist in inducing amenorrhea in women undergoing BMT. STUDY DESIGN: We evaluated the use of the GnRH agonist leuprolide acetate (LA) for the induction of amenorrhea in 10 postmenarcheal women prior to BMT. If there was a contraindication to the use of the intramuscular (i.m.) formulation of LA, the subcutaneous (s.c.) formulation was given as a daily intravenous (i.v.) bolus. Once the subject's platelet count was > 50,000/microL, the LA was discontinued. Menstrual bleeding, time from initiation of therapy to amenorrhea, and liver function test results were monitored. RESULTS: All subjects had induction of amenorrhea with the use of LA except for one subject with a large, myomatous uterus, who experienced light spotting. One subject who was thrombocytopenic at the prescribed time of the second dosage of i.m. LA received i.v. LA with documentation of continued pituitary/gonadal suppression. No adverse effects were determined to be directly related to either the i.m. or i.v. LA. CONCLUSION: LA is an option for the induction of amenorrhea in postmenarcheal women undergoing BMT. In thrombocytopenic subjects, administration of the s.c. formulation of LA by an i.v. route served as an alternative to i.m. injection and was documented to maintain gonadotropin suppression.

Evaluation of a self-report screening instrument to predict frailty outcomes in aging populations.

The purpose of this study is to investigate the utility of a self-report screening instrument, the Health Status Form (HSF), to predict elderly members at risk of frailty in the subsequent year. The predictive ability of self-report HSF data was also compared to the predictive ability of inpatient discharges and pharmacy dispensings from administrative utilization databases. Four HSF variables best predicted elderly members at risk of frailty: (a) age, (b) indicating that health conditions interfered with daily activities, (c) needing or receiving assistance from another person for bathing, and (d) needing or receiving assistance from another person for taking medications. The predictive model yielded sensitivity 50.7%, specificity 97.8%, and correctly classified 90.9% of the population. Self-report population-based screening is a reliable method for predicting elderly members at risk of frailty in the coming year. Further studies should test a new brief instrument composed of portions of validated measures as a stand alone screener to select frail members for care management purposes.

Preterm premature ruptured membranes: a randomized trial of steroids after treatment with antibiotics.

OBJECTIVE: To assess the effectiveness of corticosteroids in patients with preterm premature rupture of membranes (PROM) after treatment with a broad-spectrum antibiotic, ampicillin-sulbactam. METHODS: A randomized clinical trial of corticosteroids in patients with preterm PROM was undertaken after treating these patients for a minimum of 12 hours with ampicillin-sulbactam. No digital vaginal examinations were performed on these patients. Antibiotics were continued for 7 days and the steroids were repeated weekly. No tocolytics were used. The primary outcome measure was the incidence of respiratory distress syndrome (RDS). Secondary outcome measures included latency period and neonatal and maternal infectious morbidity. RESULTS: Seventy-seven patients were enrolled and data about their pregnancies were analyzed. No statistically significant difference in latency period was noted (14.7 days in the steroid group, 15.8 days in the no-steroid group). Both neonatal and maternal infectious morbidity were similar. A significant reduction in the incidence of RDS (18.4 versus 43.6%, P = .03) were observed in the steroid group. CONCLUSION: These data suggest that treating preterm PROM patients with a broad-spectrum antibiotic before corticosteroids decreases RDS without apparent adverse sequelae.

A simple tool for designing a database: bridging the communication gaps among health care providers, researchers, and programmers.

As databases are used by a greater variety of people, highly technical methods of designing them are giving way to more human, user-centered approaches. The article describes a human approach to designing a complex, multiuse database with limited resources. The article introduces a simple data modeling tool, the entity-relationship (E-R) diagram, that crosses professional boundaries and enables providers, researchers, and programmers to communicate more easily. Constructing an E-R diagram provides a human description of the social health maintenance organization (S/HMO) multisite demonstration project. This project, now in its tenth year, provides integrated acute and community-based in-home services to allow frail elderly HMO members to stay in their homes. After briefly reviewing the three types of databases and three rules of thumb for designing a relational database, the article shows how a simple E-R diagram can clarify the management and research issues of the S/HMO health care model. The article concludes with a brief discussion of the benefits and limits of housing research-related health data in a relational database.

Medical care utilization among older HMO members with and without hypertension.

OBJECTIVES: To compare hospital utilization, health status, and sociodemographic characteristics of older persons with and without hypertension and to examine the nature of the association of hypertension with medical care utilization. DESIGN: A retrospective, nonexperimental study. SETTING: A large health maintenance organization (HMO), located in the Portland, Oregon and Vancouver, Washington areas, that provides comprehensive, prepaid benefits to its members. PARTICIPANTS: Approximately 4200 older (> or = 65 years) members enrolled in the Social HMO Demonstration Project. MEASUREMENTS: The dependent variables were (1) whether a member was hospitalized (0 = no; 1 = yes) and (2) the number of hospitalizations during the 12-month period before the return of the Health Status Form, a mail questionnaire. The predictor variables were high blood pressure and other medical conditions, health status, and sociodemographic characteristics. Patients classified as hypertensive were those who self-reported high blood pressure and who received two or more dispensings for antihypertensive medications. RESULTS: Older hypertensives were more likely than older nonhypertensives to have been hospitalized (odds ratio (OR) = 1.14 (95% CI 1.01, 1.27)), self-report their health as only good or fair (P < .001), self-report IADL functional limitations (P < .001), and to be younger than nonhypertensives (P < .001). Utilization differences were similar after controlling for patients' age and gender. Factors independently associated with an increased likelihood of hospitalization were male gender (OR = 1.14 (1.00,1.31)), age (OR = 1.35 (1.00,1.81)), poor (OR = 1.32 (1.02,1.72)) or fair (OR = 1.20 (1.01,1.44)) self-rated health status, functional limitations in activities of daily living (OR = 1.74 (1.48,2.03), and self-reported heart trouble (OR = 1.50 (1.34,1.68)), stroke (OR = 1.37 (1.15,1.64)), or cancer (OR = 2.89 (1.72,4.84)). Factors independently associated with a decreased likelihood of hospitalization were excellent self-reported health (OR = 0.65 (0.47,0.90)), no physical impairments (OR = 0.59 (0.48,0.72)), and no circulation problems (OR = 0.85 (0.74,0.98)). CONCLUSIONS: Older hypertensive patients had poorer self-reported health, more functional limitations, used more hospital services, and were not as old as nonhypertensive older patients. To the extent that general health is improved by treatment of hypertension, appropriate treatment of high blood pressure may not only improve health, it may also reduce medical care utilization. Our findings offer further support for hypertension prevention, detection, and treatment programs designed to reduce or minimize hypertension's later medical complications and to reduce future utilization.

Establishing partnerships with family caregivers. Local and cosmopolitan knowledge.

Families now provide most of the care received by older people in the United States. Proposed changes in the health care system will mean that families must take an even greater role in delivering health care. It is crucial that nurses practicing in a variety of settings be prepared to establish partnerships with family caregivers in order to attend to the long-term care needs of older people.

The PREP system of nursing interventions: a pilot test with families caring for older members. Preparedness (PR), enrichment (E) and predictability (P).

The PREP system of nursing interventions, designed to increase preparedness (PR), enrichment (E), and predictability (P) in families providing care to older people, was pilot tested for acceptability and preliminary effectiveness. Eleven family units were assigned to the PREP group and 11 to a standard home health control group. The PREP group scored approximately one SD higher than the control group (p < .05) on the Care Effectiveness Scale, indicating greater preparedness, enrichment, and predictability. Further, on a rating of overall usefulness, the PREP group rated their assistance from PREP nurses (M = 9.75) as significantly higher (p < .01) than the control group rated assistance from the home health nurse or physical therapist (M = 6.57). Although not statistically significant, mean hospital costs for the PREP group ($2,775) were lower than for the control group ($6,929). Results provided support for a full intervention trial.

Establishing partnerships with family caregivers. Local and cosmopolitan knowledge.

1. The concepts of local and cosmopolitan knowledge may be used by gerontological nurses in creating partnerships with family caregivers to frail older people. 2. Local knowledge is the understanding and skills that the family brings to the caregiving situation; cosmopolitan knowledge is the understanding and skills that the gerontological nurse brings to the situation. 3. Four nursing interventions are guided by the conceptualization of local and cosmopolitan knowledge: acknowledging and affirming local knowledge when it is adequate; developing or enhancing local knowledge when it is inadequate; assisting family caregivers to apply local knowledge to problem solving; and blending local and cosmopolitan knowledge.

Iodine heterocycles: [125I] and [131I] ortho-iodosophenylphosphoric acid.

Since organic molecules tagged with radioiodine are often subject to dehalogenation, techniques are needed for "protecting" the iodine. A suggested approach was the incorporation of iodine directly into a heterocyclic compound as one of the ring's heteroatoms. Such a compound, orthoiodosophenylphosphoric acid, was synthesized with I-125 and I-131. Upon i.v. administration to dogs and rabbits, most of the radiolabel was excreted in the urine. There was no evidence of the appearance of free iodide. The renal elimination of orthoiodosophenylphosphoric acid was contrasted with the biliary excretion of another iodine heterocycle, diphenyleneiodonium. Iodine heterocycles, with appropriate substituents, may represent a useful class of compounds for biologic studies.

Technetium-99m labelled imidodiphosphate: an improved bone-scanning radiopharmaceutical.

Technetium-99m labelled imidodiphosphate was prepared in the presence of stannous ions. It was evaluated as a bone-scanning agent in animals and patients. Comparative tissue distribution studies in mice showed a relatively higher uptake of radioactivity in bone when 99Tcm -labelled pyrophosphate and diphosphonate. Accumulation of radioactivity in soft tissues, especially kidneys, was less with this radiopharmaceutical. Results in patients were most satisfactory in delineating skeletal bone and identifying bone lesions with relatively small tracer doses of the radiopharmaceutical.