Effect of convection on osteoblastic cell growth and function in biodegradable polymer foam scaffolds.

Culture of seeded osteoblastic cells in three-dimensional osteoconductive scaffolds in vitro is a promising approach to produce an osteoinductive material for repair of bone defects. However, culture of cells in scaffolds sufficiently large to bridge critical-sized defects is a challenge for tissue engineers. Diffusion may not be sufficient to supply nutrients into large scaffolds and consequently cells may grow preferentially at the periphery under static culture conditions. Three alternative culturing schemes that convect media were considered: a spinner flask, a rotary vessel, and a perfusion flow system. Poly(DL-lactic-co-glycolic acid) (PLGA) foam discs (12.7 mm diameter, 6.0 mm thick, 78.8% porous) were seeded with osteoblastic marrow stromal cells and cultured in the presence of dexamethasone and L-ascorbic acid for 7 and 14 days. Cell numbers per foam were found to be similar with all culturing schemes indicating that cell growth could not be enhanced by convection, but histological analysis indicated that the rotary vessel and flow system produced a more uniform distribution of cells throughout the foams. Alkaline phosphatase (ALP) activity per cell was higher with culture in the flow system and spinner flask after 7 days, while no differences in osteocalcin (OC) activity per cell were observed among culturing methods after 14 days in culture. Based on the higher ALP activity and better cell uniformity throughout the cultured foams, the flow system appears to be the superior culturing method, although equally important is the fact that in none of the tests did any of the alternative culturing techniques underperform the static controls. Thus, this study demonstrates that culturing techniques that utilize fluid flow, and in particular the flow perfusion system, improve the properties of the seeded cells over those maintained in static culture.

Households contaminated by environmental tobacco smoke: sources of infant exposures.

OBJECTIVES: To examine (1) whether dust and surfaces in households of smokers are contaminated with environmental tobacco smoke (ETS); (2) whether smoking parents can protect their infants by smoking outside and away from the infant; and (3) whether contaminated dust, surfaces, and air contribute to ETS exposure in infants. DESIGN: Quasi-experiment comparing three types of households with infants: (1) non-smokers who believe they have protected their children from ETS; (2) smokers who believe they have protected their children from ETS; (3) smokers who expose their children to ETS. SETTING: Homes of smokers and non-smokers. PARTICIPANTS: Smoking and non-smoking mothers and their infants < or = 1 year. MAIN OUTCOME MEASURES: ETS contamination as measured by nicotine in household dust, indoor air, and household surfaces. ETS exposure as measured by cotinine levels in infant urine. RESULTS: ETS contamination and ETS exposure were 5-7 times higher in households of smokers trying to protect their infants by smoking outdoors than in households of non-smokers. ETS contamination and exposure were 3-8 times higher in households of smokers who exposed their infants to ETS by smoking indoors than in households of smokers trying to protect their children by smoking outdoors. CONCLUSIONS: Dust and surfaces in homes of smokers are contaminated with ETS. Infants of smokers are at risk of ETS exposure in their homes through dust, surfaces, and air. Smoking outside the home and away from the infant reduces but does not completely protect a smoker's home from ETS contamination and a smoker's infant from ETS exposure.

Investigation of evidence for anticipatory postural adjustments in seated subjects who performed a reaching task.

The paradigm for study of anticipatory postural adjustments permits investigation of the coordination of postural and voluntary components of functional movement. The purpose of this study was to investigate whether there were anticipatory postural adjustments for voluntary movement in seated subjects under clinically relevant conditions. Eight neurologically normal subjects performed a reaching task to a target placed at shoulder height, 45 degrees to the right of midline. Onsets and magnitudes of lateral and fore-aft reactive forces associated with the movement and of electromyographic (EMG) activity of the ipsilateral deltoid and external abdominal oblique and contralateral paraspinal muscles were monitored. Conditions of trunk support, reach speed, and distance reached were manipulated. Onsets of deltoid muscle EMG activity preceded onsets of postural muscle (external oblique and paraspinal) EMG activity in 70% of all trials for seated subjects in contrast to reports of EMG activity onset in the postural muscles in advance of the prime mover in standing subjects who performed a similar task. The role of the trunk musculature and the significance of reactive forces in advance of hand movement were equivocal. This study has implications for evaluation of postural instability in persons unable to stand for testing.

A double-blind study of topically applied 5% amlexanox in the treatment of aphthous ulcers.

A double-blind trial of amlexanox (C16H14N2O4) was carried out in 32 patients with recurrent oral aphthous ulcerations. During the treatment period, which lasted for 3 days, patients received either placebo topical paste or 5% amlexanox paste. The paste was applied by the investigator twice per day for 3 days and once on the fourth day. Efficacy was assessed by the following parameters: 1) pain measured by the patients marking a 15-cm line between poles connoting no pain versus severe pain; 2) erythema evaluated by the investigator on a four-point scale ranging from none to strong; 3) size determined by investigator measurement of the perpendicular dimensions of the ulcer; and 4) an investigator's improvement scale consisting of six rank-ordered points from -1 for worsening of the ulcer with respect to previously described criteria to +4 when the ulcer had healed completely. All evaluations were based on a comparison with the day 1 visit of the patient. Outcomes for patients receiving the active ingredient were superior on all four criteria of effectiveness. Group differences for all criteria but pain reduction were statistically significant (P < .05). No side effects were reported. It was concluded that amlexanox is effective in reducing aphthous ulcer erythema, pain, and lesional size.

Effect of patient information on the quality of pharmacists' drug use review decisions.

OBJECTIVE: To evaluate the effect of incremental increases in patient information on the quality of pharmacists' clinical decisions related to legally mandated prospective drug utilization review (DUR) responsibilities. DESIGN: Unblinded comparison of two groups. PARTICIPANTS: 28 community pharmacists in Indiana (group 1) and 32 Public Health Service pharmacists employed in the Indian Health Service (IHS) (group 2). INTERVENTIONS: Clinical cases involving prescribing problems were developed from patient charts. Each case contained four levels of increasing patient information: Level 1 included only information required for a legal prescription in Indiana; Level 2 added the patient's current medication profile, age, and allergies; Level 3 added the diagnosis or reason for use of the prescribed medication; and Level 4 added the physician's progress note. Pharmacists were asked to evaluate the prescribed drug therapy at each level of each case and complete a Dispensing Appropriateness Index (DAI) report, which included all prospective DUR criteria required by the Omnibus Budget Reconciliation Act of 1990. The quality of pharmacists' DUR decisions at each level of patient information was evaluated by comparing pharmacists' responses on the DAI reports with the consensus judgment of two clinical experts. RESULTS: The quality of both community and IHS pharmacists' DUR decisions improved significantly at each incremental level of patient information. CONCLUSION: Pharmacists in this study made better decisions when they had access to more complete patient information on which to base their decisions.