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Biomedical subjects

A Abbott

Publications and source records attributed to A Abbott.

324 records · Page 18Linked to original sources
PubMed1984

The conditioning role of saliva in streptococcal attachment to hydroxyapatite surfaces.

The solution properties of saliva and its role in conditioning both the substrate and the bacterial surface have been investigated with regard to the attachment of oral streptococci to hydroxyapatite surfaces. Saliva from eight subjects was used and the attachment of three organisms, Streptococcus mutans strains FA-1 (serotype b) and KPSK2 (serotype c) and S. sanguis T175-1, was studied. An adsorbed salivary layer on a hydroxyapatite surface substantially reduced the affinity of the organisms for the surface. Adsorbed saliva on the bacterial surfaces, however, tended to increase the organisms' affinity for saliva-coated apatite. The source of saliva was important in determining the extent of inhibition of attachment. The data indicated that the negatively charged and hydrophilic nature of salivary conditioning films was important in controlling bacterial adsorption to hydroxyapatite. The results also suggested that hydrophobic salivas could promote binding of the more hydrophobic bacteria known to be early colonizers of the teeth.

Adsorption↗
PubMed1983

The influence of ionic strength, pH and a protein layer on the interaction between Streptococcus mutans and glass surfaces.

The initial interaction between Streptococcus mutans and hard surfaces has been investigated using a rotating disc technique. The deposition to clean and BSA-coated glass of two strains of S. mutans, FA-1 (serotype b) and KPSK2 (serotype c), which exhibit different surface properties, was studied. Organisms were harvested from cultures grown in a chemostat at a dilution rate of 0.06 h-1 and suspended in NaCl solutions of defined ionic strengths and pH values. The deposition of both strains showed a strong dependence on electrolyte concentration, particularly at low ionic strengths, which was inversely related to the zeta potentials of the organisms. Similarly, the ionic strength at which maximum deposition was first noted (critical coagulation concentration) for the two strains correlated with their relative potentials. Deposition was insensitive to changes in pH at an electrolyte concentration of 0.05 M. The maximum observed deposition did not approach values predicted by theory, suggesting that a further barrier to deposition, other than electrostatic repulsion, might exist. Under all experimental conditions, some of the deposited bacteria were observed to be oscillating, suggesting that they were held at a distance from the collector surface. The cells did not, however, appear to be deposited in a secondary minimum predicted by DLVO theory hence it may be that long-range polymer interactions are also involved in the deposition of these organisms.

Glass↗
PubMed1978

A study of the interaction between oral streptococci and hard surfaces.

A rotating disc method was used to compare the tendencies of two oral streptococci to deposit on to glass and polystyrene surfaces from electrolyte solutions of varying ionic strength. Streptococcus salivarius had a greater tendency to deposit than had Streptococcus mitior under these condition. In addition to the balance of van der Waals' forces of attraction and electrostatic forces of repulsion, it is suggested that the adsorption to the glass and polystyrene surfaces of material present in the outer layers of the cell wall could play a significant part in the deposition of S. salivarius.

Adsorption↗
PubMed1978

Accident and its correlates in a psychiatric hospital.

The literature on accidental and violetn minor injuries in hospitals is reviewed. From it hypotheses about the causes and correlates of such accidents are derived. These theories are tested on a 2-year sample of accidents in a 2,400-patient mental hospital, using standard multivariate statistical procedures. Age, psychiatric disability, and sex prove to be correlates of rates of injury. Social disorganization is shown to be the intervening variable in the common theory that crowding leads to violent injury.

Accident Proneness↗
PubMedDate not supplied

Decision making of clinical teams: communication patterns and diagnostic error.

This study examined the discussion of information among mixed-status clinical teams while constructing differential diagnoses. Twenty-four ad hoc teams, each consisting of a resident, an intern, and a third-year medical student, were given two hypothetical patient cases to discuss and diagnose. Prior to discussion, team members individually viewed different versions of a videotaped interview with a "patient" (trained actor). Each videotape contained some information that was present in all three versions (shared information) and some that was present in only that version (unique information). In addition, half of the time, the cases were constructed so that the unique information that appeared in only one tape was crucial for a correct diagnosis (a "hidden profile" condition). After viewing the videotapes, team members met to discuss the case and develop a differential diagnosis. Discussions were videotaped and analyzed. Overall, shared information was mentioned more often than unique information (p < 0.0001). Furthermore, teams offered incorrect diagnoses significantly more often for hidden-profile cases than for control cases (p < 0.01). The teams' overreliance on previously shared information (inability to appropriately utilize unique information) was detrimental when a correct diagnosis demanded the inclusion of such information. Clinical discussions that require the consideration of uniquely held information may be susceptible to error.

Adult↗
PubMedDate not supplied

Hospital-based continuous quality improvement: a realistic appraisal.

OBJECTIVE: To evaluate the impact of a continuous quality improvement (CQI) multidisciplinary team process on emergency department admission times. DESIGN: Prospective observational intervention study. SETTING: A 349-bed tertiary care, university-affiliated, pediatric teaching hospital. RESULTS: The time from triage to departure from the emergency department (T1-T3) was reduced by 71 minutes, and the time from the decision to admit to departure from the emergency department (T2-T3) by 38 minutes following the planned interventions. There was no correlation between admission times and hospital inpatient census, number of emergency department admissions on a given day, or work shift. Medical patients were transferred to the wards more slowly than patients admitted by the general surgery service and several specialty surgical services once the decision to admit had been reached. No major adverse clinical outcomes could be attributed to expedited admissions. Physicians and nurses in the emergency department expressed improved satisfaction with the admissions process, while houseofficers on the wards were less satisfied. Parental satisfaction with the speed of admissions remained suboptimal. Additional potential problems with the application of CQI principles in an academic setting were identified. CONCLUSIONS: Although CQI is a promising approach to certain quality problems, a number of issues remain to be explored before full-scale implementation in academic centers can be endorsed.

Consumer Behavior↗