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Biomedical subjects

L J Goldsmith

Publications and source records attributed to L J Goldsmith.

53 records · Page 3Linked to original sources
PubMed1997

Physician responses to global physician expenditure budgets in Canada: a common property perspective.

Global expenditure budgets in the fee-for-service physician sector create management problems for both funders and physicians. Global expenditure cap policies must be designed, and appropriate institutional structures created, to mitigate perverse utilization incentives, manage collective utilization, and diffuse the internal professional and the funder-profession tensions created by a capped budget. Two Canadian provinces that adopted different approaches to the design of their physician expenditure cap policies experienced different outcomes in utilization growth. The outcomes, however, are the opposite to what one would predict based on an analysis of the incentive structures embodied in the two provinces' policies. An analytic framework developed for the study of common-property resources is applied to the differing physician responses to global budgets across the two provinces. The insights offered by this framework can guide policy design for global physician budgets, and they indicate the critical importance of physician acceptance of such a policy.

Alberta↗
PubMed1997

The use of extracorporeal membrane oxygenation in patients with gram-negative or viral sepsis.

To evaluate the use of extracorporeal membrane oxygenation (ECMO) in patients with Gram-negative or viral sepsis, a survey of ECMO centres comprising the Extracorporeal Life Support Organization was conducted. Data collected from neonatal and paediatric intensive care units included patient demographics, indicators of infection, presence of cardiac instability and respiratory criteria for ECMO. One-hundred-and-seven patients with documented sepsis were divided into survivors and nonsurvivors. Prior to ECMO, the patients with a persistent metabolic acidosis (p < 0.008) and/or hypotension requiring more than two inotropic agents (p < 0.02) to support blood pressure were less likely to survive. Also, patients with Gram-positive infections (77%) were more likely to survive their ECMO course than those with Gram-negative (60%) or viral infections (40%). Although survival is less in septic infants than in infants with traditional respiratory failure placed on ECMO, sepsis should not be a contraindication to the use of ECMO. The parents should be informed of the chances of survival with each type of sepsis or respiratory infection (if known), so that a truly informed decision can be made by the parents. We feel that the additional information regarding Gram-negative and viral sepsis should assist the clinician in this goal.

Acidosis↗
PubMed1997

The administration of complement component C9 enhances the survival of neonatal rats with Escherichia coli sepsis.

To determine the significance of neonatal C9 deficiency, an animal model was developed in the rat. By rocket immunoelectrophoresis, the concentration of C9 in pooled adult rat serum was 224 +/- 7.2 microg/mL. In contrast, the concentration of C9 in pooled serum from 1-d-old rats was only 43 +/- 3.8 microg/mL and increased during the first 3 wk of life to 170 +/- 20 microg/mL. Similarly, the capacities of neonatal rat serum to kill two pathogenic strains of Escherichia coli and to lyse sensitized sheep erythrocytes were diminished compared with adult serum but increased during the first 3 wk of life. Supplemental human C9 significantly enhanced the bactericidal and hemolytic activity of neonatal rat serum. The capacity of neonatal rats to survive after the intrapulmonary injection of E. coli was positively correlated with the serum C9 concentration, bactericidal activity, and hemolytic activity. In 2-d-old rats infected with E. coli, the intraperitoneal administration of human C9 significantly enhanced survival and also enhanced the protective effect of intraperitoneal human IgG antibodies. The data indicate that C9 deficiency predisposed neonatal rats to invasion by E. coli. The neonatal rat appears to be a suitable model with which to investigate the significance of C9 deficiency.

Age Factors↗
PubMed1997

Postoperative infection in a double-occupancy operating room. A prospective study of two thousand four hundred and fifty-eight procedures on the extremities.

The purposes of this study were to determine the rate of infection associated with elective outpatient operations on an extremity, performed in a double-occupancy operating room (one operating room designed to accommodate two separate operating teams), and to determine which factors influenced this rate. We evaluated the records of 2458 consecutive patients who had had such a procedure, performed by one of nine surgeons during a two and one-half-year period, and in whom the operative wound had been classified as clean (without a drain) or clean-contaminated (with a drain). The information regarding the factors associated with the operation and the operating-room environment was recorded for each patient at the time of the operation. Each wound was inspected periodically in the attending surgeon's office for at least thirty days postoperatively. Using definitions established by the Centers for Disease Control, the attending surgeon determined the presence of infection primarily by judging whether there was purulent drainage or whether erythema or swelling at the operative site was beyond that expected from the procedure. Of the 2458 patients, thirty-seven (1.5 per cent; 95 per cent confidence interval, 1.1 to 2.1 per cent) had infection of the operative wound. Only eight patients (0.3 per cent) had deep infection, with seven of the infections necessitating a reoperation. Infection developed in thirty of the 2311 clean wounds, a rate of 1.3 per cent (95 per cent confidence interval, 0.9 to 1.8 per cent), and in seven of the 147 clean-contaminated wounds, a rate of 4.8 per cent (95 per cent confidence interval, 2.3 to 9.5 per cent) (p = 0.001). No cross-contamination occurred between patients who had infection. The rate of infection was not related to the number of patients who were operated on in the same room at the same time. Logistic regression analysis, used to account for confounding factors, demonstrated a significant association between the classification of the wound (use of a drain) and a higher rate of infection (p = 0.006) as well as between the instillation of a topical steroid solution and a lower rate of infection (p = 0.04). It also demonstrated a significant difference, with respect to the rate of infection, among individual surgeons (p = 0.02).

Adolescent↗
PubMed1996

Physician impact analysis predictions in Ontario hospitals: does the emperor have clothes?

Physician impact analysis (PIA) is a human resource planning tool used to predict the impact on hospital resources of adding a new or replacement physician to a hospital's medical staff. This article describes the findings of a study which examined the extent to which PIAs are used in Ontario acute care hospitals and the accuracy of PIA predictions. The results suggest that although PIA appears to be widely used, there is no evidence that it meets the intended policy objective of accurately predicting physician hospital resource use.

Cross-Sectional Studies↗
PubMed1996

Observer differentiation of proximal enamel mechanical defects versus natural proximal dental caries with computed dental radiography.

OBJECTIVES: Various models have been used to study the accuracy of imaging systems for detection of dental caries. This study compares the ability of dentists to detect mechanically created defects versus natural dental caries cavitations on the proximal surfaces of extracted teeth with Computed Dental Radiography (Schick Industries, Long Island City, N.Y.). Detection rates are investigated according to lesion depth to permit comparisons to be made between studies in the literature with other mechanical defects or natural caries models. Discrimination of natural caries versus artificial defects with Computed Dental Radiography is also compared with a previous report that used standard dental film. STUDY DESIGN: Fifty-two extracted molar and premolar teeth were mounted into representative sets of maxillary and mandibular posterior arches for bite-wing radiography. There were 16 proximal surfaces with natural caries and 28 proximal surfaces with mechanical defects. An optical bench was used to ensure constant beam geometry. A 1.8 cm acrylic soft tissue equivalent attenuator was placed in front of the receptor. Thirty dentists acted independently as observers to differentiate between sound proximal tooth surfaces, natural dental caries, and mechanical defects. Evaluation of intra- and interobserver variability was made with use of the kappa statistic. The Zelen test of odds ratios was used to test for homogeneity, and the Mantel-Haenszel analysis plus stratified logistic regression were used for inference about the common odds ratio. Significance was set at p < 0.05. RESULTS AND CONCLUSIONS: Ignoring stipulation of cavity type, detection was 74% for mechanical defects and 67% for natural caries. The odds of detecting a mechanical defect were 1.40 times the odds of finding natural dental caries cavitation of the same depth. Lesion depth did influence the probability of correctly identifying the presence of a lesion; the odds of identifying cavitation increased 1.41 times with every 0.1 mm increase in lesion depth. Correct designation of lesion type was 1.42 times more likely with mechanical defects than with natural caries (p = 0.003). Intraobserver (kappa = 0.65) and interobserver (kappa = 0.43) agreements were fair to good. Discrimination between natural and artificial lesions was less with the Computed Dental Radiography than that found in our previous study with standard direct emulsion x-ray film.

Bicuspid↗
PubMed1996

RVG-S, VIXA, and Ektaspeed film in detection of proximal enamel defects under orthodontic bands.

An in vitro investigation was carried out to compare CCD-based intraoral radiographic systems with E-speed film for the detection of proximal enamel defects beneath orthodontic bands, with and without added niobium filtration to attenuate the x-ray beam. Twenty caries-free extracted teeth were randomly divided into five groups. Fifteen of 30 contacting proximal surfaces remained lesion free; the other 15 received a small, medium large mechanically induced enamel defect. Images were made with and without the addition of 30 microns niobium filtration, and with and without orthodontic bands. Six dentists were viewers. Receiver operating characteristic (ROC) curves were developed for each modality under each test situation. The area under the curve (Az) was used as an index of diagnostic accuracy, and the critical ratio was used for statistical comparisons. In the absence of orthodontic bands, the Az values for E-speed film and for nonenhanced RVG-S were greater than for all other modalities tested, indicating that they have the greatest diagnostic accuracy. With orthodontic bands, the RVG-S with steep gradient enhancement (X-function) had a higher Az value than all other modalities. Addition of niobium had no significant effect on defect detection. CCD-based devices hold no diagnostic advantage over conventional film for detecting changes in the density of enamel not covered by orthodontic bands. Contrast enhancement of digital images (RVG-S X-function) holds promise for the detection of such changes beneath orthodontic bands.

Bicuspid↗
PubMed1996

Mechanical defects in dental enamel vs. natural dental caries: observer differentiation using Ektaspeed Plus film.

The value of imaging modalities in enabling the observer to detect proximal dental caries has been tested previously using both natural carious cavitations and mechanical defects. This study compared the ability of dentists to detect mechanically created defects and natural dental carious cavitations on the proximal surfaces of extracted teeth, and to differentiate between the two. Detection rates according to lesion depth were also investigated. There was a difference in the ability of readers to detect natural proximal dental carious cavities and mechanical defects in the proximal enamel. The odds of detecting artificial cavities was 2.92 times the odds of diagnosing natural caries cavitations. There was great variation in the ability of the dentists to identify natural and artificial lesions. According to logistic regression, when the cavity depths are equal, the mechanical defects in the proximal dental enamel are easier to identify than are natural enamel dental caries cavitations. The odds ratio charts provided from this study show the depths of mechanical and natural lesions that are comparable in diagnostic challenge. These charts might permit rough approximations to be made when comparing previously published papers that variously use both mechanical defects and natural caries. Use of poorly designed in vitro models for testing can produce a false guide to the clinical performance of diagnostic systems.

Dental Caries↗
PubMed1995

Severity and carbamazepine level at time of initial poison center contact correlate with outcome in carbamazepine poisoning.

We reviewed data from carbamazepine poisonings reported to the Kentucky Regional Poison Center from January 1986 through March 1992 to identify information available at the time of poison center contact which correlates to outcome. The Spearman rank correlation test was used to describe the relationship between two ordinal variables and interval-level variables. The Kruskal-Wallis test was used to determine the relationship between categorical and ordinal variables. Two way analysis of variance was used to test the effect of routine carbamazepine use on final severity and carbamazepine level of 345 reports involving carbamazepine poisoning; 263 (76%) involved only carbamazepine ingestion and formed the database. One hundred eighty four (70%) carbamazepine ingestions occurred in victims < or = 17 years old, 79 (30%) occurred in adults. Severity assigned at the time of initial poison center contact was significantly correlated with outcome severity for children and adults (r > or = 0.9, p < 0.00001). The amount reported ingested influenced the correlation between initial and final severity; whereas, time elapsed between ingestion and poison center contact did not alter the correlation between initial and final severity. The reason for ingestion was significantly correlated with outcome (p < 0.00001). A significant correlation between outcome and peak carbamazepine level for each age group was observed (pediatric r = 0.5, p < 0.00001, and adult r = 0.4, p = 0.008). Carbamazepine levels > 85 mumol/L (> 20 mcg/mL) were associated with more severe toxicity.

Adolescent↗
PubMed1993

Cell-cycle-dependent phosphorylation and activity of Chinese-hamster ovary topoisomerase II.

Cell-cycle-dependent protein levels and phosphorylation of DNA topoisomerase II in relation to its catalytic and cleavage activities were studied in Chinese-hamster ovary cells. Immunoreactive topoisomerase II protein levels were maximal in G2-phase cells, intermediate in S- and M-phase cells, and minimal in a predominantly G1-phase population. When the phosphorylation of topoisomerase II in vivo was corrected for differences in specific radioactivity of intracellular ATP, the apparent phosphorylation of S- and M-phase topoisomerase II was altered significantly. Relative phosphorylation in vivo was found to be greatest in M-phase cells and decreased in the other populations in the order: S > G2 > asynchronous. Phosphoserine was detected in every phase of the cell cycle, with a minor contribution of phosphothreonine demonstrated in M-phase cells. Topoisomerase II activity measured in vivo as 9-(4,6-O-ethylidene-beta-D-glucopyranosyl)-4'-demethylepipodophylloto xin (VP-16)-induced DNA double-strand breaks (determined by neutral filter elution) increased in the order: asynchronous < S < G2 < M. Topoisomerase II cleavage activity, assayed in vitro as the formation of covalent enzyme-DNA complexes, was lowest in S phase, intermediate in asynchronous and G2-phase cells, and maximal in M phase. Topoisomerase II decatenation activity was 1.6-1.8-fold greater in S-, G2- and M-phase populations relative to asynchronous cells. Therefore DNA topoisomerase II activity measured both in vivo and in vitro is maximal in M phase, that phase of the cell cycle with an intermediate level of immunoreactive topoisomerase II but the highest level of enzyme phosphorylation. The discordance between immunoreactive topoisomerase II protein levels, adjusted relative phosphorylation, catalytic activity, cleavage activity and amino acid residue(s) modified, suggests that the site of phosphorylation may be cell-cycle-dependent and critical in determining catalytic and cleavage activity.

Animals↗
PubMed1988

Does suggestibility modify acute reactions to passive cigarette smoke exposure?

The influence of suggestibility on responses to passive cigarette smoke exposure was tested in a group of 24 healthy adult nonasthmatic nonsmokers and 16 asthmatic nonsmokers. Sixty-five-min exposures to air and to moderate (17 ppm carbon monoxide) and heavy (31 ppm carbon monoxide) concentrations of machine-produced cigarette smoke were carried out according to a design that permitted all six permutations of the three treatments to be equally represented. Nonasthmatic subjects exercised intermittently at an intensity inducing a respiratory ventilation of 43.6 liters/min, while asthmatic individuals were at rest, in a 14.6-m3 chamber; all viewed a bank of burning cigarettes during each exposure. Significant dose-response relationships were observed for reported symptoms, deterioration of pulmonary function, increase in nasal airflow resistance, and increase of carboxyhemoglobin levels. These findings could reflect either a pure physiological response, or an interaction between physiological and psychological responses. For asthmatics, correlations between pulmonary function responses and baseline measures of suggestibility showed 5/45 (11%) significant correlations (P less than 0.05) for both the ratio of saline diluent/air FEV1 during methacholine inhalation challenge and an index derived from the Minnesota Multiphasic Personality Inventory (MMPI), while no significant correlations were shown with the James "locus of control" test. Nonasthmatics showed 4/45 (9%) significant correlations for both the James test and the MMPI index, and 1/45 (2%) for the ratio of saline diluent/air FEV1. It is concluded that while suggestibility may augment physiological responses to passive smoking, any effect is relatively weak.

Adult↗
PubMedDate not supplied

Effects of vasoactive intestinal peptide on human sperm motility.

Sperm flagellar activity is modulated by cAMP. In target tissues, vasoactive intestinal peptide (VIP) stimulates adenyl cyclase activity, which elevates intracellular cAMP levels and activates protein kinase activity. This study investigated the effects of VIP on motility of sperm from 17 subjects. Motile activities, monitored before (0 min, baseline) and for 40 min after incubation with VIP (0.2 microgram/mL cell suspension), were analyzed by computer-assisted semen analysis. The data (mean +/- SEM) are expressed as percentages of baseline values and changes were compared by trend analysis for interval level measures by repeated measures analysis of variance orthogonal polynominal contrasts. The addition of VIP significantly increased motile sperm concentration (110 +/- 17% [10 min], 132 +/- 15% [20 min], 152 +/- 18% [30 min], 125 +/- 18% [40 min]; p < .02) and sperm with rapid straight-line motility (V > 25 microns/s) (167 +/- 20%, 174 +/- 19%, 173 +/- 23%, 141 +/- 16%; p < .02). Mean track speed (micron/s) was increased (125 +/- 12%, 134 = 9%, 129 +/- 12% and 126 +/- 12%; p < .02), while mean progressive velocity, amplitude of head displacement, and beat frequency were not affected by VIP. These results indicate that VIP stimulates sperm motile activity by cAMP-mediated phosphorylation of axonemal proteins.

Adenylyl Cyclases↗
PubMedDate not supplied

Changes in hearing acuity in ambulance personnel.

OBJECTIVES: To determine whether emergency medical technicians (EMTs) and paramedics suffer excessive hearing loss as a result of occupational noise exposure. A secondary objective was to determine noise levels in a modern ambulance. METHODS: This retrospective study reviewed audiograms for EMTs and paramedics currently employed by the Louisville Emergency Medical Services. The age-adjusted threshold shift was calculated for the right and left ears at 1,000, 2,000, and 4,000 Hz in 81 of these individuals. Seventy-four of the subjects also had measurements that allowed similar calculations at 3,000 Hz in both ears. The age-adjusted threshold shift was then correlated with the elapsed time. Second, noise levels were measured inside an ambulance at several times during an eight-hour shift. RESULTS: The correlation coefficient of age-adjusted threshold shifts and elapsed time was greatest at 2,000 Hz in the left ear but was still not significant at -0.2692. The noise levels in the ambulance ranged from 58 dBA in the patient compartment while stationary to 84 dBA in the forward cab with the windows down and the siren in use. CONCLUSION: There was no significant correlation between the number of months elapsed between audiograms and the age-adjusted threshold shift at any frequency in either ear. There appears to be no excessive loss of hearing acuity in ambulance personnel. The noise levels in the study ambulance stayed well below the Occupational Safety and Health Administration (OSHA) guidelines.

Adult↗
PubMedDate not supplied

Comparison of the safety of early enteral vs parenteral nutrition in mild acute pancreatitis.

BACKGROUND: This prospective study was designed to compare the safety, efficacy, cost, and impact on patient outcome of early total enteral nutrition (TEN) vs total parenteral nutrition (TPN) in acute pancreatitis. METHODS: Patients admitted with acute pancreatitis or an acute flare of chronic pancreatitis, characterized by abdominal pain and elevated serum amylase and lipase, were randomized to receive either isocaloric and isonitrogenous TEN (via a nasojejunal feeding tube placed endoscopically) or TPN (via a central or peripheral line) started within 48 hours of admission. RESULTS: Thirty patients were studied over 32 admissions (TEN given on 16 and TPN on 16) for acute pancreatitis. There were no differences on admission in mean age, Ranson criteria, multiple organ failure score (MOF), or APACHE III score between TEN and TPN groups. Although slower to approach goal feeding over the first 72 hours of admission, TEN patients received 71.3% goal calories by day 4 vs 85.2% for TPN patients (not significant). There were no deaths and no differences between groups in serial pain scores, days to normalization of amylase, days to diet by mouth, serum albumin levels, or percent nosocomial infection. However, the mean cost of TPN per patient was over four times greater than that for TEN ($3294 vs $761, respectively, p < .001). Mean serial Ranson criteria, APACHE III, and MOF scores recorded every 2 to 3 days decreased in the TEN group, whereas those in the TPN group increased. Only the difference in the third Ranson criteria (mean 6.3 days after admission) for the TEN and TPN groups (0.5 vs 2.8, respectively) reached statistical significance (p = .002). Stress-induced hyperglycemia was worse in the TPN group, as serum glucose levels increased significantly over the first 5 days of hospitalization (p < .02), whereas those in the TEN group showed no significant change. An exacerbation of pancreatitis, occurring in one TEN patient when the nasojejunal tube was dislodged into the stomach, resolved after placement back in the jejunum. Three patients who became asymptomatic and normalized amylase on TEN flared upon advancing to diet by mouth. CONCLUSIONS: TEN for acute pancreatitis is as safe and effective, but is significantly less costly than TPN. Compared with TPN, TEN may promote more rapid resolution of the toxicity and stress response to pancreatitis. TEN via jejunal feeding should be used preferentially in this disease setting.

APACHE↗
PubMedDate not supplied

Optical densities of dental resin composites: a comparison of CCD, storage phosphor, and Ektaspeed plus radiographic film.

Density versus exposure was determined for digital and film radiographic images of various thicknesses of six dental resin composites. The curves were relatively parallel; saturation at the black end of the contrast scale occurred at lower exposures with Computed Dental Radiography (CDR, Schick Industries, Long Island City, NY) than with the Sens-A-Ray (Regam AB, Sundsvall, Sweden). Ektaspeed Plus film (Kodak Dental Products, Rochester, NY) was the least sensitive modality tested. The DIGORA storage phosphor system (Soredex-Orion, Helsinki) had a wide exposure latitude with significantly less steep characteristic slopes than for images from the charge-coupled devices (CCDs). Slopes generated for the Sens-A-Ray and the CDR were not significantly different. Slopes generated for each resin composite were not significantly different for each of the modalities. Relative radiopacities of the resin materials with respect to each other were constant across all modalities; hence, in these systems, sensor type is unlikely to affect differentiation between resin composites and dental enamel or recurrent caries.

Absorptiometry, Photon↗