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Biomedical subjects

A DeMaria

Publications and source records attributed to A DeMaria.

49 records · Page 3Linked to original sources

Determination of right atrial and right ventricular size by two-dimensional echocardiography.

No data are available on determining right atrial and right ventricular size by two-dimensional echocardiography. We performed two-dimensional echocardiograms on eight human right-heart casts obtained at autopsy and on 50 patients who underwent complete left- and right-heart catheterization. Measurement of individual dimensions of the long and short axes of the right atrium and ventricle from right heart casts closely correlated with the volume of these structures as determined by water displacement. Further, individual dimensions by cross-sectional echo correlated well with actual casts dimensions. Subsequently, echocardiographic measurements of right atrial and ventricular long and short axes were obtained in the apical four-chambered view in a group of normals and compared with a group of patients with right ventricular volume overload states. Mean values for right atrial short-axis and long-axis measurements were greater in right ventricular volume overload patients than in normals: 6.5 +/- 0.3 vs 3.6 +/- 0.1 cm, and 6.0 +/- 0.3 vs 4.2 +/- 0.1 cm, respectively (both p less than 0.001). In addition, measurements of both individual dimensions as well as planed area of the right ventricle were greater in right ventricular volume overload patients than in normals: maximal short axis 6.1 +/- 0.3 vs 3.5 +/- 0.2 cm, mid-short axis 6.1 %/- 0.4 vs 2.8 +/- 0.2 cm, and area 40 +/- 2.6 vs 18 +/- 1.2 cm2 (all p less than 0.001). There were no differences in right ventricular long-axis measurement. Two-dimensional echocardiography provided better separation of normals from right ventricular volume overload patients than did M-mode techniques. Thus, two-dimensional echocardiography, with the apical four-chambered view, enables accurate visualization of the right atrium and ventricle in almost all patients. Futher, measurements of right atrial and right ventricular size by two-dimensional echocardiography readily distinguish normal patients from those with right ventricular volume overload.

Adolescent↗

Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements.

Four hundred M-mode echocardiographic surveys were distributed to determine interobserver variability in M-mode echocardiographic measurements. This was done with a view toward examining the need and determining the criteria for standardization of measurement. Each survey consisted of five M-mode echocardiograms with a calibration marker, measured by the survey participants anonymously. The echoes were judged of adequate quality for measurement of structures. Seventy-six of the 400 (19%) were returned, allowing comparison of interobserver variability as well as examination of the measurement criteria which were used. Mean measurements and percent uncertainty were derived for each structure for each criterion of measurement. For example, for the aorta, 33% of examiners measured the aorta as an outer/inner or leading edge dimension, and 20% measured it as an outer/outer dimension. The percent uncertainty for the measurement (1.97 SD divided by the mean) showed a mean of 13.8% for the 25 packets of five echoes measured using the former criteria and 24.2% using the latter criteria. For ventricular chamber and cavity measurements, almost one-half of the examiners used the peak of the QRS and one-half of the examiners used the onset of the QRS for determining end-diastole. Estimates of the percent of measurement uncertainty for the septum, posterior wall and left ventricular cavity dimension in this study were 10--25%. They were much higher (40--70%) for the right ventricular cavity and right ventricular anterior wall. The survey shows significant interobserver and interlaboratory variation in measurement when examining the same echoes and indicates a need for ongoing education, quality control and standardization of measurement criteria. Recommendations for new criteria for measurement of M-mode echocardiograms are offered.

Aorta↗

Aortic aneurysm eroding the esophagus. Case report and review.

A 71-year-old woman developed dysphagia and hematemesis with an endoscopic diagnosis of esophageal submucosal hematoma. Post mortem examination demonstrated an aorto-esophageal fistula as the etiology of her hematemesis. The differential diagnosis of upper gastrointestinal bleeding in the elderly patient without cirrhosis is discussed. A review of the literature on aorto-esophageal fistula is included.

Aged↗

Gastrointestinal candidiasis in rats treated with antibiotics, cortisone, and azathioprine.

Conventional albino rats treated with peroral chloramphenicol, gentamicin, and/or parenteral cortisone were challenged with Candida albicans Antibiotics and cortisone were equally effective in predisposing the animals to colonization by the fungus. All animals treated with both antibiotics and cortisone developed defined, focal, superficial invasion of the cornified squamous epithelium of the stomach next to its junction with the glandular mucosa, as well as focal superficial invasion of the esophagus. Equivalent yeast cell and mycelial inocula of C. albicans were equally effective in producing colonization and invasion of the gut. Dissemination of the fungus from the gut was not found even after the addition of azathioprine to the treatment regimen; however, such addition did predispose to more extensive and severe lesions of the esophagus and stomach. Approximately 25% of infected cortisone- and antibiotic-treated rats developed agglutinins against C. albicans by 22 to 23 days after challenge, whereas 15% developed precipitins. The antibiotic-cortisone-treated rat may be a useful and consistent experimental model in the study of gastrointestinal candidiasis.

Animals↗

Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. American Society of Echocardiography Committee on Standards, Subcommittee on Quantitation of Two-Dimensional Echocardiograms.

We have presented recommendations for the optimum acquisition of quantitative two-dimensional data in the current echocardiographic environment. It is likely that advances in imaging may enhance or supplement these approaches. For example, three-dimensional reconstruction methods may greatly augment the accuracy of volume determination if they become more efficient. The development of three-dimensional methods will depend in turn on vastly improved transthoracic resolution similar to that now obtainable by transesophageal echocardiography. Better resolution will also make the use of more direct methods of measuring myocardial mass practical. For example, if the epicardium were well resolved in the long-axis apical views, the myocardial shell volume could be measured directly by the biplane method of discs rather than extrapolating myocardial thickness from a single short-axis view. At present, it is our opinion that current technology justifies the clinical use of the quantitative two-dimensional methods described in this article. When technically feasible, and if resources permit, we recommend the routine reporting of left ventricular ejection fraction, diastolic volume, mass, and wall motion score.

Algorithms↗

Interactions of rifampin and trimethoprim in vitro.

Combination of rifampin and trimethoprim (TMP) has been suggested as a means of preventing the emergence of bacterial resistance to the individual agents and of achieving synergistic antimicrobial activity. By means of standard techniques of antimicrobial susceptibility testing, combinations of rifampin and TMP were tested against clinical isolates of a variety of aerobic bacteria. Synergism was defined as a fourfold or greater decrease in the minimal inhibitory concentration (MIC) of the more active agent in the combination. Antagonism was defined as a fourfold or greater increase in the MIC of the more active agent. No change or, at most, a twofold change was considered to represent indifference. Combinations of rifampin and TMP in ratios of 7:1, 7:2, and 1:1 demonstrated synergistic activity against 12%, 13%, and 28% of 440 isolates, respectively. Antagonism was observed in 10%, 9%, and 8% of strains tested against the above ratios. Killing curves determined with selected organisms failed to demonstrate synergistic antibacterial activity. Combinations of rifampin and TMP failed to prevent the emergence of resistance to both drugs when selected strains of various bacteria were exposed to serial, subinhibitory concentrations. Thus, synergism of rifampin and TMP was observed in only a minority of strains tested, and combination of the two agents failed to prevent the emergence of drug resistance in vitro.

Bacteria↗

Blood safety.

Since blood is a biologic product, it is unlikely that the risk for transfusion-transmitted infection will ever be reduced to zero. The approach to emerging infections associated with transfusion of blood and blood products includes assessing the transmissibility of the agent by this route; developing effective prevention strategies, including screening tests and donor deferral policies; improving viral and bacterial inactivation procedures; and surveillance for known, as well as emerging and poorly characterized, transfusion-transmitted agents. Vigilance is needed to help ensure proper balance between safety and the availability of blood. Finally, vigilance needs to extend to the developing world, where the basic elements to reduce transfusion-transmitted infections and systems of disease surveillance are often not available.

Biological Products↗

Immune responses to a recombinant human immunodeficiency virus type 1 (HIV-1) gpl60 vaccine among adults with advanced HIV infection. Massachusetts gp160 Working Group.

OBJECTIVE: To assess immunogenicity of recombinant human immunodeficiency virus type 1 (HIV-1) envelope vaccine (rgp160) in late HIV infection. STUDY DESIGN/METHODS: HIV-infected volunteers (n = 142), with CD4+ T lymphocyte counts of <400/mm3, were enrolled in a dose-comparison, open-label trial with stratification by CD4+ cell count, randomization to a primary series at two dose levels, and a sub-group receiving interferon-gamma (IFN-gamma) as an adjuvant. Subjects received booster doses of vaccine over a follow-up period of 18-28 months. RESULTS: At 6 and 12 months, 36% and 38% of participants, respectively, had new or augmented antibody titers (> or =4-fold increase) against one or more gpl60 epitopes (C1, V3, C41, 448C). Delayed-type hypersensitivity (DTH) to intradermal gpl60, initially not present in any participant, developed after immunization in 41%, with higher prevalence in participants receiving the lower dose of vaccine. Both antibody and skin test responses occurred in 20-25% of vaccine recipients. Virtually all antibody and skin test responses occurred in participants with initial CD4+ cell counts of >100 cells/mm3. IFN-gamma had no significant effect on immune response. Immunization was well tolerated. Trends in CD4+ cell count, clinical events, and laboratory findings correlated with baseline CD4+ T lymphocyte count stratum and not with immunization regimen. Opportunistic conditions occurred at expected rates. Viral load trends (p24 antigen in all participants and viral RNA by reverse transcription-polymerase chain reaction in a subset of 26 participants) did not correlate with immunization regimen. CONCLUSION: Immunization of patients with advanced HIV infection with rgpl60 resulted in new and augmented humoral and DTH responses, without unexpected significant adverse events or evident clinical benefits attributable to immunization.

AIDS Vaccines↗

The cost of rabies postexposure prophylaxis: one state's experience.

OBJECTIVE: This study was undertaken to evaluate trends in the use of rabies postexposure prophylaxis (PEP) before, during, and following an epidemic of raccoon rabies in Massachusetts. METHODS: The authors reviewed initiation of PEP as reported to the Massachusetts Department of Public Health (MDPH) from August 1994 to December 1995 and surveyed hospital pharmacies to determine the number of vials of Human Rabies Immune Globulin (HRIG) dispensed from 1991 through 1995 and charges to patients per vial. RESULTS: PEP use increased dramatically, from 1.7 per 100,000 population in 1991 (pre-epidemic) to 45 per 100,000 in 1995 (after the first stages of the epidemic). The median costs per patient for biologics was $1646 (range: $632-$3435). Including physician and emergency room charges, per-patient median costs were $2376 (range: $1038-$4447). Total health care charges for PEP in Massachusetts in 1995 were estimated at $2.4 million to $6.4 million. CONCLUSIONS: Given the rapid increase in use of PEP, further studies should be undertaken to determine the appropriateness of use, and other alternatives, such as oral wildlife vaccines, should be considered.

Animals↗