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Biomedical subjects

R Bush

Publications and source records attributed to R Bush.

At least 19 recordsLinked to original sources
PubMed2005

Injury caused by self-inoculation with a vaccine of a Freund's complete adjuvant nature (Gudair) used for control of ovine paratuberculosis.

OBJECTIVE: To document the occurrence and consequences of accidental self-inoculation of vaccinators (producers, farm employees, contractors) with the recently registered Gudair vaccine for the control of ovine paratuberculosis in Australia. DESIGN AND PROCEDURE: A survey of the first 50 primary producers permitted to use the vaccine in sheep and a description of six cases of accidental self-inoculation for which medical attention was sought, and which occurred after the vaccine became widely available. RESULTS: The survey recorded that, of 37 respondents vaccinating 155,523 sheep, there were 21 incidents of exposure to the vaccine, an overall rate of one incident per 7406 vaccinations. In five of these incidents there was only superficial skin contact with vaccine; in 16 there was needle penetration without vaccine injection. There were no reports of self-inoculation with vaccine. Six cases of self-inoculation with Gudair vaccine that required medical intervention are described. Of these five were in males and one in a female; four involved injection of vaccine into the leg and single cases involved a foot or hand. Most cases required surgical removal of the injected vaccine to allow wound repair; three required extensive surgery and open drainage. Even with surgery recovery took as long as 9 months. Possible risk factors for self-inoculation and the resulting outcome are discussed. CONCLUSIONS: Gudair ovine paratuberculosis vaccine can cause prolonged granulomatous inflammation if inadvertently injected into human tissue. After.self-inoculation, early surgical debridement of the damaged tissue and drainage to remove the vaccine material are advised to avoid progression to extensive necrosis.

Animals↗
PubMed2000

Evaluation of thrombolysis and angioplasty in a porcine iliac artery thrombosis model: application of endovascular stent-graft-induced thrombosis.

PURPOSE: To develop a novel endovascular thrombosis model in the porcine iliac artery for the evaluation of thrombolysis and angioplasty. MATERIALS AND METHODS: A stent-inversion-graft (SIG) model combining either a 3-mm or 5-mm tapered expandable polytetrafluoroethylene (ePTFE) graft attached within a self-expandable, 10-mm nitinol stent was placed in the left common iliac artery via an ipsilateral common femoral artery approach in 24 pigs. When the iliac artery was thrombosed, urokinase (250,000 IU) plus heparin (1,000 units) were pulse sprayed via a contralateral femoral approach (n = 12). Saline pulse-spray was used as a control group (n = 12). Balloon angioplasty was performed to eliminate the stenotic tapered graft within the stent after successful thrombolysis. The efficacy of the thrombolysis was assessed with use of intravascular ultrasound (IVUS) and arteriogram. RESULTS: Both the 3-mm tapered and 5-mm tapered SIG models caused iliac artery occlusion in 22 +/- 5 and 41 +/- 9 minutes, respectively, after the deployment. Luminal patency was re-established successfully in all occluded arteries after urokinase infusion. Angioplasty was successful in eliminating the tapered stenosis and restoring the normal diameter in all iliac arteries treated with urokinase. Complete thrombolysis was achieved in both models treated with urokinase. CONCLUSION: This novel endovascular approach of inducing arterial thrombosis is simple to perform and reliably produces arterial thrombosis. The intraluminal stenosis is also amenable to angioplasty. This model is useful for the evaluation of antithrombotic treatment modality and adjunctive endovascular interventions.

Alloys↗
PubMed2000

Opportunities and challenges in Medicaid managed care: the experience in Maryland.

OBJECTIVE: The effects of the Maryland Medicaid mandatory managed care programs on Medicaid beneficiaries are examined with the main objective of gaining insight into the initial experience and beneficiary satisfaction with Maryland's Medicaid program. The background of the Maryland Medicaid system, initial implementation, results of beneficiary satisfaction surveys, and future concerns are discussed. STUDY DESIGN: An observational study based on survey data. DATA AND METHODS: Beneficiary surveys mailed to adult and child participants in HealthChoice and the Rare and Expensive Case Management (REM) Medicaid programs in Maryland are analyzed. Descriptive univariate and bivariate data statistics are used. RESULTS: The 4 questions rating satisfaction with primary care provider (PCP), relevant specialists, all providers, and the overall health plan indicate high levels of satisfaction in both adult and child populations. CONCLUSIONS: The Maryland Medicaid programs appear to have met the goal of providing a comprehensive, coordinated healthcare system of quality care during their first year of operation. The satisfaction of these beneficiaries suggests that with an appropriate risk-adjusted capitation approach, managed care organizations (MCOs) can successfully provide for even the most complex needs of Medicaid members.

Community Health Services↗
PubMed1995

Measurement of the absolute number of functioning low-density lipoprotein receptors in vivo using a monoclonal antibody.

MAC188 S/S is a monoclonal antibody which can be used in vivo to measure the absolute number of functioning low-density lipoprotein (LDL) receptors in a rabbit. The antibody binds to the extra-cellular domain of the LDL receptor and binding is not blocked by the presence of LDL. When the antibody-receptor complex is internalized, receptor recycling is inhibited for several hours. Thus when saturating doses of MAC188 S/S are administered intravenously, the amount of antibody removed from the blood (minus non-specific removal) is determined solely by the total number of LDL receptors in an animal. In this study MAC188 S/S was used to measure the number of LDL receptors in control rabbits and in animals treated with 17 alpha-ethinyl oestradiol. After treatment (which caused a 47% decrease in plasma cholesterol), receptor-mediated removal of MAC188 S/S from the blood was saturated in both groups following injection of 3.0 mg of antibody per kg body weight. Based on the amount of antibody removed via the LDL receptor at this dose, the total number of accessible LDL receptors was calculated as (2.0 +/- 0.3) x 10(15) receptors per kg body weight in control rabbits and (4.0 +/- 0.4) x 10(15) receptors per kg body weight in oestrogen-treated animals. The number of receptors in various organs was also determined. The monoclonal antibody approach therefore, allows accurate determination of LDL receptor numbers in animals with markedly different concentrations of circulating LDL, conditions in which the use of endogenous ligand would be subject to significant errors.

Animals↗
PubMed1995

Smoking cessation and absence from work.

BACKGROUND: This study examines the relationship between smoking cessation and absence from work by analyzing data collected from a large sample of ex-smokers. In particular, it is hypothesized that if smoking cessation is of benefit for work attendance, the incidence of absence should be inversely related to the amount of time elapsed since smoking cessation. METHODS: A multivariate logit model of absence incidence is proposed which includes variables measuring the amount of time since smoking cessation. This model is then estimated using data collected from a sample of 4,812 ex-smokers as part of the 1989/1990 Australian National Health Survey. RESULTS: The estimated coefficients indicate that the probability of absence among ex-smokers is highest for those who only stopped smoking in the past year and progressively falls with the number of years since smoking cessation, with persons who last smoked at least 20 years ago found up to 4.5 times less likely to be absent from work than persons who ceased smoking during the previous year. CONCLUSIONS: Smoking cessation is not only associated with improved health outcomes, but also with improved behavioral outcomes, such as increased work attendance. However, such improvement is observed only over relatively long periods of time.

Absenteeism↗
PubMed1995

Smoking and absence from work: Australian evidence.

This study reports on research into the relationship between absence from work and smoking. A key feature of the study is the data, which come from the National Health Survey (NHS) undertaken in 1989/90 in Australia. Involving responses from more than 54,000 individuals, the NHS provides what is almost certainly the largest and most comprehensive data set available in the world today containing information on both absence and smoking behaviour. Moreover, the data permit controls to be applied for a large number of influences thought to have some bearing on work attendance. Logit models of absence incidence over a two week period are estimated, and smoking is consistently found to have a large and significant impact on absence. This impact, however, is not consistent across the sexes. The probability of a male smoker being absent from work is estimated to be 66% greater than that for a male who has never smoked. For females, the corresponding figure is just 23%. The findings also suggest that it is important to distinguish ex-smokers from other non-smokers, with the incidence of absence among ex-smokers being almost as high as that for current smokers. Finally, no evidence was uncovered to suggest that absence varied with the actual quantity of tobacco smoked, as measured by both the number of cigarettes smoked and estimated daily nicotine and tar intakes.

Absenteeism↗
PubMed1994

Partners of problem drinkers: moving into the 1990s.

The literature on partners of problem drinkers is reviewed. Originally research and treatment viewed partners of problem drinkers from a pathological perspective. This paper suggests an alternative stress and coping perspective as less stigmatizing and more realistic in terms of the experiences of these individuals.

Journal Article↗
PubMed1994

Cardiac tamponade due to primary pericardial lymphoma in a patient with AIDS.

Cardiac tamponade due to lymphomatous involvement of the heart is a dramatic and unusual complication. Because of their nonspecific clinical presentation, these tumors are seldom diagnosed antemortem. We report the case of a patient with AIDS who presented with signs and symptoms of cardiac tamponade. Emergency pericardiocentesis followed by staging studies revealed large cell B-lymphocyte lymphoma confined to the pericardial space. With combination chemotherapy, a durable complete response was obtained. This case illustrates the potential benefit of aggressive treatment of extranodal non-Hodgkin's lymphoma in a patient with AIDS. The case is of particular interest because of the unusual development of isolated pericardial involvement as the sentinel sign of lymphoma.

Adult↗
PubMed1991

Combined modality therapy of Hodgkin's disease: 10-year results of National Cancer Institute of Canada Clinical Trials Group multicenter clinical trial.

The purpose of this study was to compare four methods of treatment for stage III-IV Hodgkin's disease. Between January 1972 and September 1976, 266 patients with stage IIIB, IVA, and IVB Hodgkin's disease from 21 cancer treatment centers across Canada were registered as eligible; 40 were found to be ineligible. Of the 226 remaining patients, only seven were followed for less than 10 years. All patients received three courses of mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) chemotherapy, which induced a complete response (CR) in 36%; an additional 42% obtained adequate disease control. Patients were randomly assigned to (1) treatment with radiation to the abdomen and mantle (group AX3, 62 patients) or (2) continue their treatment with an additional three courses of MOPP (group A, 105 patients). For the A group, a second randomization took place 3 months later (regardless of status at that time) to (1) no further treatment (AC6, 23 patients), (2) radiotherapy to the abdomen and mantle (AX6, 48 patients), or (3) maintenance chemotherapy at 3-month intervals for 1 year (AC10, 26 patients). The survival of AX3 patients was somewhat better than for the A group, but the difference was not significant (P = .0565). However, there was a significant interaction (P = .0029) between age and treatment, so that among patients less than 30 years of age, the survival of the A group was better, whereas for older patients, treatment with AX3 resulted in improved survival. Age itself remained a significant prognostic factor for survival after controlling for the amount of radiotherapy delivered to the abdomen and the dose intensity of vincristine for the first three courses of chemotherapy. The addition of radiation therapy to MOPP significantly reduced the frequency of nodal relapses. These results suggest that combined modality therapy may be beneficial for some patients with Hodgkin's disease and that age must be carefully considered in interpreting the results of clinical trials in Hodgkin's disease.

Adolescent↗
PubMed1991

Micro method of analysis for magnesium in myocardial biopsies.

We developed a single-stage technique involving a proteolytic enzyme (pepsin) for the solubilization of cardiac muscle to measure magnesium in tissue. This new method has been developed specifically for use with very small cardiac biopsy samples (less than 1 mg) obtained with modern myocardial biopsy forceps. Pepsin digestion of the tissue releases magnesium ions into solution and, after centrifugation and dilution with lanthanum chloride, the resulting supernate is suitable for analysis by atomic absorption spectrometry. Recovery of magnesium after a single digestion approaches 99%. In direct comparison studies of pepsin digestion and a traditional method involving nitric acid extraction, the pepsin digestion consistently yielded more magnesium. In contrast to traditional methods of tissue solubilization, pepsin digestion is well suited to extraction of magnesium from the small biopsy samples commonly presented for analysis in clinical practice.

Biopsy↗
PubMed1990

Concurrent chemoradiation in advanced cervical cancer.

The pelvis is the predominant site of failure following radical radiotherapy (RT) for locally advanced cervical cancer. We report the results of phase I-II studies on 200 patients with bulky (greater than or equal to 5 cm) carcinoma of the cervix. Patients were treated between 1981 and 1988 on sequential protocols of concurrent chemoradiation to establish an acceptable treatment regimen. RT with daily or partially hyperfractionated pelvic (n = 154) or pelvic plus paraaortic (n = 46) fields was given by continuous (n = 154) or split course (n = 46) regimens. Infusional fluorouracil (5-FU) in a dose of 1 g/m2/day was given on the first and last 4 days of a 5-week course of continuous RT, or with both halves of split course RT. Seventy-eight patients received bolus mitomycin C (Mit-C), 6 mg/m2, once or twice with the start of the 5-FU infusion. The median external RT dose was 46 Gy (range 40 to 65 Gy) followed in 90% (n = 181) by a single intracavitary application of 40 Gy using a linear source of cesium-137. Median follow up is 2.5 years (range 0.6 to 6.9 years) and is sufficient to reliably estimate late toxicities. Acute toxicities were transient oral mucositis (13), RT interruption for enteritis (7), febrile neutropenia (3), and thrombocytopenic tumor bleed (1). Serious late toxicities resulted in death in 3 patients and occurred in bladder in 6 and in bowel in 25, including 8 patients with tumor recurrence. The incidence of late bowel toxicity correlated with the specific therapy given and decreased with each successive protocol. On logistic regression the only treatment variable showing a statistically significant effect on complications was the use of Mit-C (P = 0.0053). Pelvic RT and 5-FU alone produced fewer complications, only 4/105, than historically seen with standard pelvic RT alone. Three-year pelvic control and survival rates were 85 and 71% respectively in stage Ib/II (n = 100) and 50 and 42% in stage III/IV (n = 100). Encouraged by these results and decreased toxicity, we have begun a phase III study to determine whether the addition of concurrent 5-FU to continuous partially hyperfractionated pelvic RT improves local control and survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Responses of pulmonary slowly adapting receptors to airway occlusion in cat.

To determine if phasic pulmonary slowly adapting stretch receptor (SAR) activity is abolished by the no-inflation test, we monitored the discharge patterns of individual SAR during respiratory cycles with and without lung inflation. In spontaneously breathing, anesthetized cats, the airway was occluded at end-expiration at both control functional residual capacity (FRC) and an end-expiratory lung volume elevated with an expiratory threshold load (ETL). We recorded from 67 SAR at FRC and from 32 of these while on the ETL. At FRC, 29 (43%) continued to fire during occluded inspiratory efforts. Of 20 afferents which did not fire during occlusions at FRC, 13 discharged during occlusions on ETL. At FRC, 39% of SAR had modulation indices (MI; difference between peak and minimum discharge frequencies during occlusion expressed as a fraction of the same change during a non-occluded breath) greater than 0.2; on ETL, 72% of SAR had MI greater than 0.2. Identification of medullary inspiratory neurons as ones with (I beta) and without (I alpha) SAR input depends on vagally-mediated respiratory drive to the airway smooth muscle in which SAR are located, the response characteristics of SAR projecting to that neuron, and end-expiratory lung volume.

Animals↗
PubMed1986

Health promotion--an ethical perspective.

Physicians, individually and collectively, are formulating and marketing health promotion campaigns in unprecedented numbers. While such efforts are generally consonant with the ethic of promoting health by scientifically valid means, care must be taken not to compromise this ideal in pursuit of marketable, simplistic models of disease.

Ethics, Medical↗
PubMed1985

A comparison of intranasal and oral flunisolide in the therapy of allergic rhinitis. Evidence for a topical effect.

Intranasal flunisolide is an effective treatment for allergic rhinitis. Flunisolide has high bioavailability when administered to normal subjects (50% of an intranasal dose reaches the systemic circulation) with minimal systemic effects. Bioavailability in patients with active rhinitis averages 62.4 +/- 15.7%. The oral dose bioequivalent to 100 micrograms intranasally is 500 micrograms. To define the comparative trial and systemic effects of intranasal flunisolide in patients with active allergic rhinitis, a multicenter, randomized, double-blind, placebo-controlled study was conducted during the 1983 ragweed hayfever season. Ninety-nine patients with ragweed hayfever for greater than or equal to 2 years and positive prick skin tests to ragweed were randomly allocated to one of three treatment groups: 0 = oral flunisolide 500 micrograms b.i.d. and intranasal placebo b.i.d.; N = intranasal flunisolide 50 micrograms per nostril b.i.d. and oral placebo b.i.d.; P = intranasal and oral placebo b.i.d. Treatment continued for 4 weeks. Patients kept daily symptom scores. Patients were evaluated by a blinded observer every 2 weeks and were globally evaluated at the study's end. Data were analyzed for each center and pooled. There were no significant differences in symptom severity of sneezing, nasal congestion, and throat itch in the 0 (oral flunisolide) and P (placebo) groups. N (nasal flunisolide) was significantly more effective than O or P (P less than or equal to 0.005) for each symptom for at least one 2-week period. Global evaluation demonstrated control of overall hayfever severity for N (nasal flunisolide) but not for O (oral flunisolide). We conclude that the therapeutic efficacy of flunisolide is achieved by topical and not by systemic action.

Administration, Intranasal↗
PubMed1984

Concurrent radiation, mitomycin C and 5-fluorouracil in poor prognosis carcinoma of cervix: preliminary results of a phase I-II study.

Between July 1981 and June 1983, 27 patients with advanced primary squamous cell carcinoma (SCC) of cervix (FIGO Stages IIIB, IVA or extensive nodal involvement) and 8 with recurrent disease were treated using a pilot regimen of combination chemotherapy (CT): Mitomycin C (MIT), 5 Fluorouracil (5 FU), and radiation therapy (RT). CT and RT doses on this Phase I-II Study were escalated to the current regimen. A split course of RT was used, either pelvic RT alone (4560 Gy in 28 fractions) or the same pelvic RT plus para-aortic RT (3600 Gy in 24 fractions). CT was given: MIT 6 mg/M2 IV push day 1, and 5 FU 1.0 g/M2 (maximum daily 1.5 g) by continuous IV infusion days 1 through 4 of each half-course of RT. This was followed by one application of intrauterine 137Cs when possible. Three of the 8 patients with recurrence in the pelvis or para-aortic nodes had a complete response (CR) to CT-RT and are alive without disease at 19, 19 and 22 months after treatment, respectively. Twenty of the 27 (74%) primary patients had a CR. With a median duration of follow-up of 6 months 4/20 have relapsed, 1 in RT field, 2 at distant sites, and 1 in both. Pelvic disease remains controlled in 19/27 (70%) including one patient salvaged with surgery. The acute toxicity of this regimen was tolerable: 2/35 developed transient leukopenia with one febrile episode, 9/35 developed transient thrombocytopenia without bleeding. Symptomatic sigmoid strictures developed in two patients, one requiring surgical intervention. Sigmoid perforation occurred in one patient and contributed to death. Typically, near complete regression of tumor is noted on completion of the external RT, reproducing the dramatic responses that have been observed in SCC of the anal canal, esophagus and head and neck, with this CT-RT regimen. A Phase III Study is required to establish whether the enhanced response rates to CT-RT will result in increased pelvic control and cure rates compared to those after RT alone.

Antibiotics, Antineoplastic↗
PubMed1983

Intracortical processing of visual contour information in cats.

Fine slices made through the gray matter perpendicular to the surface of cortical area 17-18 in the cat produced no change in behavioral measures of grating acuity, a modest reduction in vernier acuity and a proportionately larger effect on contour orientation acuity. The introduction of vertical gaps in the vernier acuity targets produced increases in the vernier offset threshold proportional to the gap size both before and after cortical damage, except at the largest vertical gap values employed (1-1.5 degrees) where no change in thresholds was observed after surgery. Neither the preoperative vernier thresholds nor the postoperative changes in vernier thresholds were predicted by the measured contour orientation thresholds and thus an orientation discrimination model of vernier acuity was not supported. The results of this study support the view that intracortical processing in area 17-18 is important in both vernier and orientation acuity, but the neural mechanisms mediating the two capacities are different.

Animals↗