Characterization of a sustained-release delivery system for combined cytokine/peptide vaccination using a poly-N-acetyl glucosamine-based polymer matrix.

Identification of tumor-associated antigens (TAAs) and their class I MHC-restricted epitopes now allows for the rational design of peptide-based cancer vaccines. A biocompatible system capable of sustained release of biologically relevant levels of cytokine and TAA peptide could provide a more effective microenvironment for antigen presentation. Our goal was to test a sustained-release cytokine/TAA peptide-based formulation using a highly purified polysaccharide [poly-N-acetyl glucosamine (p-GlcNAc)] polymer. Granulocyte-macrophage colony-stimulating factor (GM-CSF; 100 microgram) and MART-1(27-35) peptide (128 microgram in DMSO) were formulated into p-GlcNAc. Peptide release was assayed in vitro using interleukin 2 production from previously characterized MART-1(27-35)-specific Jurkat T cells (JRT22). GM-CSF release was assayed via ELISA and proliferation of M-07e (GM-CSF-dependent) cells. Local bioavailability of MART-1(27-35) peptide for uptake and presentation by antigen-presenting cells was demonstrated for up to 6 days (>0.5 microgram/ml). More than 1.0 microgram/ml GM-CSF was concomitantly released over the same period. Biocompatibility and local tissue response to p-GlcNAc releasing murine GM-CSF was determined in C57BL/6 mice via s.c. injection using murine GM-CSF (0. 2 microgram/ml) in 200 microliter of a 2.5% polymer gel. Significant lymphocytic and eosinophilic infiltration was observed 2-7 days after injection with polymer containing murine GM-CSF. The results of our studies show that this biocompatible system is capable of a sustained concomitant release of biologically active peptide and cytokine into the local microenvironment. These findings support further studies to validate a p-GlcNAc delivery system vehicle for a cytokine/TAA peptide-based cancer vaccine.

Semi-allogeneic cell hybrids stimulate HIV-1 envelope-specific cytotoxic T lymphocytes.

OBJECTIVE: The present study was designed to determine whether the HLA allogeneic T helper response stimulated by semi-allogeneic cell lines could be used as an in vitro model of immune-based therapy to stimulate HIV-specific cytotoxic T lymphocytes. DESIGN AND METHODS: Semi-allogeneic cell hybrids were obtained by the fusion of peripheral blood mononuclear cells from HIV-infected patients with the allogeneic beta2-microglobulin-deficient FO1-12 melanoma cell line. These hybrids were used as antigen presenting cells for HIV envelope peptide (env)-specific cytotoxic assays. RESULTS: The hybrid cell lines express HLA class I and II antigens from both parental cells, as well as the CD86 costimulatory molecule. HIV-specific cytotoxic T lymphocyte activity was obtained when patients' peripheral blood mononuclear cells were costimulated with env peptides plus semi-allogeneic hybrids, in contrast with stimulation with either env or hybrid cells alone. Thus, the semi-allogeneic hybrids enhanced HIV-specific killing of target cells. CONCLUSIONS: Irradiated, semi-allogeneic cell hybrids engineered for individual AIDS patients provide efficient and simultaneous co-recognition of HLA allogeneic determinants and viral antigenic determinants presented by self-HLA molecules on the same antigen presenting cells and results in the generation of enhanced HIV-specific cytotoxic T lymphocyte activity.

Rural-urban blood lead differences in North Carolina children.

OBJECTIVE: To examine the prevalence of and risk factors for having a blood lead elevation among young children in a predominantly rural state. METHODS: 20,720 North Carolina children at least 6 months and < 6 years of age were screened between November 1, 1992 and April 30, 1993 using either capillary or venous measurements of blood lead. Children were tested through routine screening programs that target low-income families and, hence, were not randomly selected. Eighty-one percent of the children were screened through local public health departments, and 19% were tested at private clinics. RESULTS: The estimated prevalences of having an elevated blood lead level among those tested were: 20.2% (> or = 10 micrograms/dL), 3.2% (> or = 15 micrograms/dL), and 1.1% (> or = 20 micrograms/dL). Black children were at substantially increased risk of having a blood lead > or = 15 micrograms/dL (odds ratio (OR) = 2.1, 95% confidence interval (CI) = 1.7 to 2.5). Children aged 2 years old had an elevated risk (OR = 1.4, 95% CI = 1.1 to 1.7) compared to 1-year-olds, and males were at slightly increased risk (OR = 1.2, 95% CI = 1.0 to 1.4). Living in a rural county was nearly as strong a risk factor as race (OR = 1.9, 95% CI = 1.6 to 2.4). The effect of rural residence was even greater among certain subgroups of children already at highest risk of having an elevated blood lead. The type of clinic (public vs private) where a child was screened was not associated with blood lead outcome. These same trends were seen for children with blood lead levels > or = 20 micrograms/dL. CONCLUSIONS: Among children screened from rural communities, the prevalence of elevated blood lead is surprisingly high. Though few physicians have embraced universal lead screening, these data support the need for greater awareness of lead exposure in children living outside of inner-cities.

Dry powder inhalers are bioequivalent to metered-dose inhalers. A study using a new urinary albuterol (salbutamol) assay technique.

Metered-dose inhalers (MDIs) are extensively used to deliver drugs to the lungs but are driven by chlorofluorocarbon (CFC) propellants. The worldwide phasing out of CFCs within the next 5 to 10 years presents difficulties to the pharmaceutical industry. The mean +/- SD relative lung bioavailability of albuterol to the lung following inhalation of 400 micrograms of albuterol from an MDI, the Rotahaler and Diskhaler in 10 well-trained volunteers, was 2.83 (0.78), 1.72 (0.99), and 2.64 (1.23)%, respectively, expressed as a percentage of the nominal dose. The delivery of albuterol to the lungs from the MDI and Diskhaler was similar. In nine asthmatic subjects, the relative lung bioavailability of albuterol following inhalation with the MDI and Diskhaler was 1.19 (0.79) and 2.38 (1.46)%, respectively, expressed as a percentage of the nominal dose. There was no difference in reversibility 30 min after administration of the dose by the two methods. Similar lung deposition from the Diskhaler in volunteers probably is due to efficient MDI technique, which was absent in the asthmatic subjects. The Diskhaler does not rely on coordination during inhalation and therefore is easier to use.

Promoting institutional change to encourage primary care: experiences at New York Medical College and East Carolina University School of Medicine.

New York Medical College and East Carolina University School of Medicine significantly changed their curricula and organizational structures in response to The Robert Wood Johnson Foundation's Generalist Physician Initiative (GPI). Seven common elements essential to successful institutional change were retrospectively identified at these two markedly different schools. They are (1) using national priorities to promote need for change, (2) establishing internal and external financial support, (3) developing a planning process and organizational structure to effect change, (4) devising an ongoing evaluation strategy, (5) sustaining positive attitudes toward primary care, (6) integrating community-based physicians, and (7) sustaining interest in the GPI. Within this framework, the authors present the GPI objectives at both schools, discuss examples of methods for institutional change and describe successes, failures, and lessons learned. The authors conclude that both schools have significantly increased the number of students choosing primary care careers and note the general perception of improvement in the quality of primary care educational programs, student recruitment, departmental collaboration, and faculty development opportunities. Although these changes have not yet been fully institutionalized, the similarities of the processes described may be of value to others addressing similar issues.

Influence of medical school on medical students' opinions about primary care practice.

PURPOSE: To compare first- and fourth-year medical students' opinions about primary care practice. METHOD: A cross-sectional survey was made of medical students at New York Medical College (NYMC) and East Carolina University School of Medicine (ECUSOM) over three years (1993-94, 1994-95, and 1995-96). Three consecutive classes of first-year students from both schools (n = 807), two consecutive classes of fourth-year NYMC students (n = 373), and three consecutive classes of fourth-year ECUSOM students (n = 221) were given a self-administered questionnaire about professional aspects of primary care practice. Responses to ten items about primary care practice were the independent variables in a logistic regression analysis. Career choice, categorized as primary care or non-primary care, was the dependent variable. Independent, two-tailed t-tests were employed to compare the responses of the first-year students interested in primary care careers with those of the fourth-year students interested in primary care careers. RESULTS: In all, 639 (79%) of the first-year students and 396 (67%) of the fourth-year students returned completed questionnaires. The first-year students interested in primary care careers were significantly more likely to believe that primary care practice has more prestige, has more intellectual stimulation, needs a large knowledge base, and involves work that is more important than that of non-primary care physicians, and were significantly more likely to disagree with the assertion that in primary care practice, physicians have more control over their working hours. With one exception (prestige of primary care practice), all these independent variables were significant for the fourth-year students as well. The comparison of the first- and fourth-year students indicated that the fourth-year students were significantly more likely to believe that primary care practice has more intellectual stimulation, needs a large knowledge base, and requires knowledge that non-primary care practice may not; they were also significantly more likely to disagree with the assertions that primary care practice is adequately compensated, has more prestige, and allows more control over working hours. CONCLUSION: It appears that students' positive perceptions about primary care practice may change as realistic perceptions about the professional demands on primary care physicians develop during medical school.

Rapid traction for reduction of cervical spine dislocations.

There is still some controversy about the reduction of unilateral and bilateral facet dislocations in the cervical spine. We have reviewed the notes and radiographs of 210 such patients; reduction was attempted by manipulation under anaesthesia (MUA) in 91, and by rapid traction under sedation in 119, using weights up to 150 lb (68 kg). Our results suggest that early reduction in patients with neurological deficit gives the best chance of neurological recovery, that rapid traction is more often successful than MUA, and that traction is safer than MUA. We found that the use of heavy weights with close monitoring was safe and brought about reduction in an average time of 21 minutes. We recommend this technique for the reduction of all cervical facet dislocations.

First-year medical students' knowledge of and attitudes toward primary care careers.

BACKGROUND AND OBJECTIVES: This study compared the knowledge of and attitudes toward primary care in relation to anticipated career choices of first-year medical students at two medical schools that differ significantly in production of primary care physicians. METHODS: A cross-sectional survey was conducted at a private, urban school in the Northeast where only a small percentage of students enter family practice residencies and a public, rural school in the Southeast where entry into family practice is among the highest in the country. The survey was conducted during the first semester of medical school. RESULTS: Ninety-six percent of students correctly identified general internal medicine, general pediatrics, and family practice as primary care fields; 51.8% identified these fields as "specialties." Statistically significant differences were seen between the percentages of students at the two schools who planned careers in primary care, suggesting that selection processes may differ between the two schools. There were no significant differences between students at the two schools in correctly identifying the characteristics of primary care practice. Only minor differences between the schools were found in assessments of the need for or importance of primary care. CONCLUSIONS: Although a significant difference in student interest in becoming primary care physicians was detected at the two schools, a surprising similarity was shown in their knowledge and attitudes about primary care. New attitudinal markers will need to be developed to help admissions committees select students most likely to enter primary care careers.

Sinusitis in children and adolescents.

Sinusitis is common in children and adolescents, most frequently as a complication of a viral upper respiratory tract infection or allergic rhinitis. The diagnosis usually is suggested by symptoms of a viral upper respiratory tract infection persisting beyond 10 days without improvement or severe symptoms with fever and purulent rhinitis. Young children frequently do not have the symptoms (headache) or physical findings (sinus tenderness) seen in older patients. Radiographic evaluation may be helpful if the clinical presentation is atypical or severe. Antibiotics remain the primary therapeutic agent of choice in pediatric sinusitis, with other therapeutic modalities having little proven efficacy.

Musculoskeletal tuberculosis in Bradford - a 6-year review.

INTRODUCTION: Tuberculosis (TB) remains the most common cause of death from infectious disease world-wide. In the UK, the incidence of TB has risen by 25% over the last 10 years; extrapulmonary diagnosis remains challenging and can be delayed. This study evaluates the epidemiology of musculoskeletal tuberculosis in a large multi-ethnic UK city. PATIENTS AND METHODS: A review of prospectively recorded data of incidence, anatomical site, ethnic distribution, treatment and drug resistance of musculoskeletal tuberculosis over a 6-year period was performed. RESULTS: From January 1999 to December 2004, there were 729 TB notifications; 61 cases (8.4%) had musculoskeletal involvement. Of the patients, 74% were immigrants from the Indian subcontinent; nearly 50% had spinal involvement; 24 patients underwent surgical intervention; 29 were subjected to either diagnostic or therapeutic radiological intervention; and resolution of symptoms was achieved in 59 out of 61 cases. CONCLUSIONS: This study highlights the high proportion of musculoskeletal TB in immigrant patients in an area with a relatively large at-risk population, but will also serve to alert physicians, in areas with smaller at-risk populations, of the possibility of musculoskeletal TB.

Papilloedema and optic atrophy in chronic hypercapnia.

Two patients are described with hypercapnia of 10 and 13 years duration. Both patients had papilloedema at different stages of their illness and one patient developed optic atrophy. Whether such changes are due to local retinal vascular changes, general change in cerebral vasculature or the result of raised intracranial pressure is unknown. A combination of all seems likely. Computerized axial tomography brain scan on Case 2 was compatible with cerebral oedema and the development of optic atrophy (Case 1) suggests cerebral oedema and consequent raised intracranial pressure as the major factor in the development of papilloedema in hypercapnic patients. Skull radiographic changes have not previously been reported in hypercapnia. The duration of the papilloedema is critical in the development of atrophy.

Physiotherapy and intermittent positive-pressure ventilation of chronic bronchitis.

Patients aged over 45 admitted to hospital with exacerbations of chronic bronchitis alone or in association with cor pulmonale, pneumonia, or respiratory failure were placed in one of three groups (men with hypoxia, men without hypoxia, and women). Patients within these groups were then randomly allocated to receive either standard drug treatment alone or standard drug treatment plus intermittent positive-pressure ventilation (IPPV). No significant differences occurred between the controls and patients receiving physiotherapy and IPPV in any group. We conclude that when a patient with chronic bronchitis and respiratory failure is deteriorating emphasis should be on correct diagnosis, fluid electrolyte balance, and nutrition together with oxygen treatment when necessary, rather than on additional physiotherapy.

Effect of physiotherapy on pulmonary function. A laboratory study.

33 patients with acute exacerbations of chronic bronchitis were studied within 4 days of admission to hospital. Physiotherapy produced an acute rise in lung volume and conductance, without altering specific conductance. There was no consistent change in arterial-blood gases.

Investigations of an optimal inhaler technique with the use of urinary salbutamol excretion as a measure of relative bioavailability to the lung.

BACKGROUND: A simple non-invasive method, in which a urine sample is taken 30 minutes after drug administration, has previously been shown to be a measure of the relative bioavailability of salbutamol to the lungs. This technique has been used to determine an optimal inhaler technique with commercially available metered dose inhalers (MDI). METHODS: Ten healthy subjects were trained in the use of MDIs. Each inhaled 4 x 100 micrograms salbutamol in a series of experiments to examine the relative bioavailability to the lung after different respiratory manoeuvres. Urine collection intervals were 0-0.5 hours and 0.5-24 hours after administration. RESULTS: There was significantly greater elimination of unchanged salbutamol 30 minutes after administration, indicating a greater relative bioavailability of salbutamol to the lungs after (1) exhaling gently to residual volume rather than to functional residual capacity before inhalation; (2) slow inhalation (10 l/min) compared with fast inhalation (50 l/min); (3) breath holding for 10 seconds after inhalation compared with no breath holding. CONCLUSIONS: All patient information leaflets and healthcare personnel should standardise the instructions given to patients and should adopt the inhalation method proposed.

Semiallogeneic cell hybrids as therapeutic vaccines for cancer.

The authors have engineered a cell line that can be used in human studies as a universal donor cell for the formation of semiallogeneic cell hybrids after fusion with patient-derived tumor cells. These hybrids can be irradiated and injected as a patient-tailored therapeutic vaccine in patients affected by virtually any type of cancer. A crucial step in this research effort has been the derivation of an allogeneic cell line (FO1-12) that expresses both a dominant selectable marker (neomycin resistance) and a recessive selectable marker (sensitivity to hypoxanthine, aminopterin, and thymidine), which allows easy selection of semiallogeneic cell hybrids derived from the fusion of FO1-12 cells with patient-derived tumor cells. Tumor-infiltrating lymphocytes derived from select patients with melanoma and exposed to semiallogeneic cell hybrids from the same patient were better able to specifically lyse autologous tumor cells. Furthermore, FO1-12 cells express carcinoembryonic antigen, which is ubiquitous in adenocarcinomas, and fusion of FO1-12 cells with various patient-derived adenocarcinoma cells showed that the hybrid cells also express carcinoembryonic antigen. Because of the results of these preclinical studies, the authors were given permission to use semiallogeneic cell hybrids for immunotherapy of patients with metastatic melanoma or metastatic adenocarcinoma who had not responded to standard treatment regimens. Treatment with semiallogeneic vaccines is associated with minimal or no toxicity and can induce a specific anti-tumor immune response.