Is bovine dentine an appropriate substitute for human dentine in erosion/abrasion tests?

The study aimed to compare the dentine wear of primary and permanent human and bovine teeth because of erosion/abrasion and evaluate if bovine dentine is an appropriate substitute for human dentine in further erosion/abrasions tests. Dentine samples from deciduous molars and human third molars as well as from calves' and cattle's lower incisors were prepared and baseline surface profiles were recorded. Each day all samples were demineralized in 1% citric acid, tooth brushed with 100 brushing strokes with toothpaste slurry and stored in artificial saliva for the rest of the day. This cycle was run for 20 days. Afterwards, new surface profiles were recorded and dentine wear was calculated by a customized computer program. Dentine wear because of erosion/abrasion was not statistically, significantly different for human third molars and cattle's lower incisors (P = 0.7002). The dentine wear because of erosion/abrasion of deciduous molars and calves' lower incisors was significantly different (P < 0.0000). No statistically significant difference in the dentine wear of human third molars and cattle's lower incisors was observed, so that the use of cattle's lower incisors as substitute for adult human teeth for further investigations in erosion/abrasion studies could be accepted.

Attenuation and activation characteristics of steel and tungsten and the suitability of these materials for use in a fast neutron multileaf collimator.

A computer controlled multileaf collimator (MLC) is being designed to replace the multirod collimator (MRC) at present used to shape the d(48.5) + Be neutron beam from the Harper Hospital superconducting cyclotron. The computer controlled MLC will improve efficiency and allow for the future development of intensity modulated radiation therapy with neutrons. The existing MRC uses tungsten rods, while the new MLC will use steel as the leaf material. In the current study the attenuation and activation characteristics of steel are compared with those of tungsten to ensure that (a) the attenuation achieved in the MLC is at least equivalent to that of the existing MRC, and (b) that the activation of the steel will not result in a significant change in the activation levels within the treatment room. The latter point is important since personnel exposure (particularly to the radiation therapy technologists) from induced radioactivity must be minimized. Measurement of the neutron beam attenuation in a broad beam geometry showed that a 30 cm thick steel leaf yielded 2.5% transmission. This compared favorably with the 4% transmission obtained with the existing MRC. Irradiation of steel and tungsten samples at different depths in a 30 cm steel block indicated that the activation of steel should be no worse than that of tungsten.

Loop diuretics and in vitro relaxation of human fetal and newborn mouse airways.

This study was designed to test the hypotheses that furosemide directly causes relaxation in human fetal airway and that delivery of loop diuretics to either the adventitial or epithelial surface of newborn mouse airway results in equivalent relaxation. Isometric tension changes were measured in human fetal (11-16 wk) trachea and mainstem bronchus rings exposed to furosemide (300 microM) or saline after acetylcholine or leukotriene D(4) constriction. Significant decreases in isometric tension to furosemide were demonstrated after constriction with acetylcholine or leukotriene D(4). To examine the site of effect and mimic aerosolized and systemic administration, furosemide (3-300 microM) and bumetanide (0.3-30 microM) were applied separately to epithelial and adventitial surfaces of newborn mouse airways. No differences in airway diameter changes to epithelial or adventitial furosemide or bumetanide were observed, but a 10-fold difference in potency was found. In summary, human fetal airway relaxed to furosemide when constricted with either neurotransmitter or inflammatory mediator in vitro. Further, no differences in relaxation to equimolar epithelial and adventitial furosemide were observed in isolated newborn mouse airway. Taken together, this provides evidence that furosemide has a direct, nonepithelial-dependent effect on airway smooth muscle tone.

Differential effects of inhaled nitric oxide and hyperoxia on pulmonary dysfunction in newborn guinea pigs.

This study tested the hypothesis that inhaled nitric oxide (NO) and combined NO and hyperoxia will result in less pulmonary dysfunction and delay onset of respiratory signs compared with hyperoxia-exposed newborn guinea pigs (GPs). GPs were exposed to room air (n = 14), 95% O(2) (n = 36), 20 parts per million (ppm) NO (n = 14), or combined 20 ppm NO and 95% O(2) (NO/O(2), n = 13) for up to 5 days. Data evaluated included latency interval for onset of respiratory distress, pressure volume curves, lung histology, and bronchoalveolar lavage (BAL) polymorphonuclear cells (PMNs), proteolytic activity, and total protein. NO-exposed GPs did not develop respiratory distress and had no evidence of pulmonary dysfunction. O(2)-exposed GPs developed respiratory distress after 1-5 days (median 4.0) vs. 3-5 days (median 5.0) for NO/O(2) exposure (P < 0.05). BAL from O(2)-exposed GPs showed increased PMNs compared with NO/O(2)-exposed GPs. O(2)- and NO/O(2)-exposed GPs had comparable reduced lung volumes, lung histology, and increased BAL proteinase activity and total protein. In summary 1) O(2) exposure resulted in multiple measures of pulmonary dysfunction in newborn GPs, 2) 5-day exposure to NO produced no noticeable respiratory effects and pulmonary dysfunction, and 3) short-term exposure (

Evaluation of an early discharge program for infants after childbirth in a military population.

The objective of this study was to evaluate the outcome of an early discharge program for infants with regard to length of stay, patient safety, maternal satisfaction, and hospital expense in a military population. The study consisted of a retrospective analysis of data from two 6-month periods--March to August 1994 (before early discharge) and March to August 1996 (after early discharge)--in a military, tertiary care, teaching hospital. The criteria for early discharge included healthy term singleton newborns delivered by uncomplicated vaginal delivery with maternal support systems, transportation, and phone access. The interventions included maternal education regarding maternal and infant care and telephone follow-up at 48 hours and 5 days after discharge. The main outcome measures included length of hospital stay, inpatient cost, infant health services utilization, and maternal satisfaction (measured by survey). During the 6-month study periods in 1994 and 1996, a total of 1,911 deliveries were examined. The mean number (+/- SD) of hospital days per infant was 2.54 +/- 0.83 in 1994 compared with 1.88 +/- 1.03 in 1996. There was not a statistically significant difference in the number of readmissions between 1994 (9 of 1042, 0.86%) and 1996 (12 of 869, 1.38%) (odds ratio = 1.61, 95% confidence interval = 0.67, 3.83). A review of the infant health services utilization revealed a statistically significant increase in the total number of clinic visits (scheduled and unscheduled) before the 2-week well-child visit for the 1996 group. However, that group did not experience a change in the number of emergency room visits. Seventy-five percent of mothers were satisfied with the program as assessed by questionnaire. In addition, the program was able to save 599 inpatient hospital days, for a total cost savings of $442,903.23 in 1996. This reduction in inpatient hospital days netted an average cost savings of $509.67 per infant. By following strict discharge criteria, increasing parent education before discharge, implementing a phone follow-up system, and ensuring easy access to care, an early discharge program in our military population was not associated with increased adverse newborn outcomes and reduced costs.

A single dose of intramuscularly administered dexamethasone acetate is as effective as oral prednisone to treat asthma exacerbations in young children.

OBJECTIVE: To evaluate whether a single dose of intramuscularly administered dexamethasone acetate (IM Dex) was as safe and effective as a 5-day course of oral prednisone (PO Pred) in the treatment of young children with mild-moderate exacerbations of asthma. STUDY DESIGN: A prospective, randomized, investigator-blinded study was done in a tertiary care medical center in children (6 months to 7 years of age) who required corticosteroids to treat mild-moderate asthma exacerbations as outpatients. Patients were randomized to receive either a single dose of IM Dex ( approximately 1.7 mg/kg) or PO Pred ( approximately 2 mg/kg/d for 5 days). Clinical asthma score, behavioral changes, albuterol use, and tolerance of the medication were recorded in a home diary for 7 days. Cortisol/creatinine ratios on first morning void urine samples were obtained on day 14. The primary outcome measures were changes in clinical asthma score through day 5 and tolerance of the medication. RESULTS: Fifteen patients in the IM Dex group (mean age 37 months) and 17 in the PO Pred group (mean age 36 months) completed the study. Clinical asthma score improved significantly in both groups during the first 5 days of therapy, and no significant difference was seen in the rate of improvement between the 2 groups. Three children refused more than 75% of their prednisone doses, and another 4 missed 30% to 50% of the doses despite their parents' best efforts. The intramuscular injection caused no complications, and approximately 70% of parents in both groups stated that they would choose IM Dex to treat their child's next asthma exacerbation. CONCLUSION: In this group of children a single intramuscular injection of dexamethasone acetate was as effective as a 5-day course of PO Pred for the management of mild-moderate outpatient asthma exacerbations.

m-hydroxy benzoylecgonine recovery in fetal guinea pigs.

Recently, meta-hydroxybenzoylecgonine (m-OH BE) was identified by gas chromatography-mass spectroscopy during quantitative analysis for cocaine. Identification of m-OH BE in addition to the routinely identified benzoylecgonine by gas chromatography-mass spectroscopy confirmatory assays may increase detection of cocaine-exposed infants and decrease false negative results. However, it is not known whether m-OH BE is derived directly from benzoylecgonine or from hydroxylated cocaine, or whether this metabolite is produced in the fetus or transferred across the placenta from the maternal circulation. We quantitated the recovery of cocaine, benzoylecgonine, and m-OH BE from amniotic fluid, fetal meconium, fetal intestine, and maternal urine for up to 4 days after single dose administration of either cocaine or benzoylecgonine to pregnant time-bred guinea pigs. m-OH BE was recovered from meconium after maternal injections of cocaine and benzoylecgonine. There was no significant detection of m-OH BE from amniotic fluid or intestine and minimal recovery from maternal urine after either cocaine or benzoylecgonine administration. Detection of m-OH BE in meconium increased the identification of in utero exposed guinea pigs, and the greatest yield of m-OH BE from meconium occurred later than that observed for cocaine or benzoylecgonine.

Cost consequences of implementation of an early obstetrical discharge programme in a military teaching hospital.

We evaluate the cost consequence of a voluntary early obstetrical discharge programme in a military teaching hospital. The study involved a control group of routine obstetrical discharge patients with uncomplicated vaginal delivery from March 1 to August 31, 1994 and the study group of early obstetrical discharge (24-48 hours) patients with uncomplicated vaginal delivery from March 1 to August 31, 1996. There were 1,042 total control patients with routine vaginal delivery totalling 2,668 hospital days with a mean number of hospital days of 2.56 per patient. The study group of early obstetrical discharge patients with uncomplicated vaginal delivery encompassed 1,050 patients with 1,965 hospital days with mean hospital days of 1.87 per patient (p < 0.05) without an increase in postpartum clinic or emergency room visits. The total cost of admissions (cost calculation of $1,221 per hospital day) fell from $3,257,628 in the routine discharge group to $2,399,625 in the early discharge cohort showing a total cost savings of $858,003 over the 6-months study period. The average cost per obstetrical admission for routine vaginal delivery fell from $3,126 per day to $2,285 per day without an increase in the postpartum paediatric adverse outcomes. Maternal postpartum readmission rates were statistically significantly increased (p < 0.05) in the study group at 0.6% with an OR[2.32(2.17, 6.92)] but all readmissions fell outside the 48-hour early discharge window. This programme showed significant cost savings without concomitant increase in paediatric or maternal adverse outcomes.

Cost consequences of implementation of an early obstetrical discharge program in a military teaching hospital.

Objective: To evaluate the cost consequence of an early obstetrical discharge program in a military teaching hospital.Methods: The study involved a control group of routine obstetrical discharge patients with uncomplicated vaginal delivery from March to August 1994 and the study group of early obstetrical discharge (24-48 hours) patients with uncomplicated vaginal delivery from March to August 1996.Results: There were 1,042 total control patients with routine vaginal delivery from March to August 1994 totaling 2,668 hospital days with a mean number of hospital days of 2.56 per patient. The study group of early obstetrical discharge patients from March to August 1996 with uncomplicated vaginal delivery encompassed 1,050 patients with 1,965 days with mean hospital days of 1.87 per patient. The total cost of admissions (cost calculation of $1,221/hospital day) fell from $3,257,628 in the routine discharge group to $2,399,625 in the early discharge cohort showing a total cost savings of $858,003 over the 6-month study period. The average cost per admission fell from $3,126/day to $2,285/day without an increase in the postpartum pediatric or maternal adverse outcomes.Conclusion: An early obstetrical discharge program at a military teaching hospital showed significant cost savings without concomitant increase in pediatric or maternal adverse outcomes.