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Biomedical subjects

M Kebede

Publications and source records attributed to M Kebede.

7 recordsLinked to original sources
PubMed1997

In vitro susceptibilities of Bartonella henselae, B. quintana, B. elizabethae, Rickettsia rickettsii, R. conorii, R. akari, and R. prowazekii to macrolide antibiotics as determined by immunofluorescent-antibody analysis of infected Vero cell monolayers.

The in vitro susceptibilities of Bartonella (Rochalimaea) henselae, B. quintana, B. elizabethae, Rickettsia akari, R. conorii, R. prowazekii, and R. rickettsii to different concentrations of azithromycin, clarithromycin, dirithromycin, erythromycin, and roxithromycin in Vero cell cultures were evaluated. Bartonella and Rickettsia spp. were allowed to initiate infection of the antibiotic-free Vero cell monolayers, which were maintained in 16-chamber microscope slides in the absence of antibiotics at 32 degrees C in a CO2-enriched atmosphere. The monolayers were then incubated for 3 h to allow for initial host cell intracellular penetration by infecting species. After inoculation, inocula were replaced and tested with media containing 12 different concentrations of each antibiotic in replicate (10 wells of each antibiotic dilution) for each species, and the monolayers were reincubated. Tetracycline served as the control. Growth status of Bartonella spp. and Rickettsia spp. was determined by evaluation of immunofluorescent staining bacilli. Five days later, when antibiotic-free, control-infected cell monolayers demonstrated significant fluorescence, media were removed for all cell monolayers, the monolayers were fixed, and all specimens were stained with standard indirect immunofluorescent antibody reagents. Fluorescent foci were enumerated by counting such foci on random fields visualized with an epifluorescence microscope. The extent of antibiotic-induced focus inhibition was recorded for each dilution of antibiotic and compared with that of an antibiotic-negative control. Effective antibiotic dilution endpoints for inhibition of Bartonella and Rickettsia proliferation, as judged by absence of increase of significant fluorescence (as compared with no-growth controls), were enumerated by determining the number of cell culture chambers at various antibiotic dilutions that were negative or positive for significant Bartonella- or Rickettsia-specific fluorescence. All of the macrolide agents tested were readily active against all three Bartonella organisms, and azithromycin, clarithromycin, and roxithromycin may have potential in the treatment of Rickettsia infections. Animal model-based clinical trials are warranted to define the specific treatment role of the newer macrolide antibiotics.

Animals↗
PubMed1997

Do low-risk prenatal patients really need a screening glucose challenge test?

BACKGROUND: It is common practice to routinely screen pregnant women for gestational diabetes. The screening technique typically used is the 1-hour 50-g oral glucose tolerance test (OGTT), with a subsequent 3-hour 100-g OGTT for women whose 1-hour test was positive. This process can be both time-consuming and inconvenient for patients. Additionally, its sensitivity and specificity are estimated to be 70% and 87% respectively, and data about the effect of screening and treatment on low-risk pregnancy outcomes are limited. The objective of this study was to reassess the value of routine screening of all pregnant patients with a 1-hour glucose challenge test. METHODS: At a university-based family practice center with a predominantly low-risk population, a retrospective analysis was performed of all patients (n = 595) who received prenatal care and gave birth between January 1988 and December 1993. Among women in whom gestational diabetes was diagnosed on the basis of glucose tolerance testing, we identified those with risk factors for the disease, and examined whether a selective screening program based on risk factors alone would have resulted in correct diagnoses of gestational diabetes. RESULTS: Of the 595 patients, 544 (91.4%) were screened with a 1-hour 50-g OGTT. This initial screening test was positive in 76 women (12.8%). Of these, 58 (76.3%) then had a 3-hour 100-g OGTT, and 13 received a diagnosis of gestational diabetes. Nine of these 13 women had risk factors for gestational diabetes. We determined that less than 1% of prenatal patients without risk factors for gestational diabetes were ultimately found to have gestational diabetes. CONCLUSIONS: Screening with a 1-hour 50-g OGTT only those women who have identifiable risk factors for gestational diabetes is a reasonable approach to identifying the disease in a low-risk population. All pregnant women should have a thorough history taken to determine whether they have risk factors for gestational diabetes.

Adolescent↗
PubMed1993

Papanicolaou smear quality assurance: providing feedback to physicians.

BACKGROUND: The effective management of Papanicolaou (Pap) smears depends on the reliability and accuracy of obtaining and interpreting the specimen. Provider sampling error is one of the important factors contributing to inadequate specimens. Feedback on provider performance may be an effective way to improve the quality of Pap smears. METHODS: A pilot study in a university-based residency program involving resident and faculty physicians was initiated to assess the impact of feedback on performance of Pap smears. After establishing adequacy and inadequacy criteria and recording adequacy rates for 3 months, individual and group feedback was implemented. No formal educational intervention on Pap smear technique was undertaken. RESULTS: The quality of 836 Pap smears performed by 9 faculty and 13 resident physicians showed continued improvement in both sampling and slide preparation to 90% adequacy over a 9-month period. This improvement, though clinically useful, was not statistically significant owing to the relatively small numbers of smears performed by each physician. This form of feedback may be useful in both practice and educational settings. CONCLUSIONS: Feedback without any formal educational intervention led to a clinically useful trend of improvement in the quality of Pap smears, which has been sustained since the study began. This type of simple feedback may be useful in practice settings and particularly valuable in pinpointing areas for improvement for learners in residency programs.

Academic Medical Centers↗
PubMed1993

Development of a Pap smear quality-assurance system in family practice.

BACKGROUND AND OBJECTIVES: To improve the effectiveness of cervical cancer screening, quality assurance programs can be designed to ensure that normal Pap smear results are dealt with appropriately and that Pap smears yielding inadequate specimen material are brought to a physician's attention. The objective of this study was to use a new Pap Smear Quality Assurance (PAPQA) system to determine and monitor the performance of physicians in a family practice over a two-year period. METHODS: We developed a PAPQA system designed to gather data and report on: 1) Pap smear adequacy, 2) reporting of abnormal results to physicians, and 3) follow-up of patients who had abnormal Pap smear results. We followed these parameters for two years. RESULTS: Over a two-year period, 2,771 cervical Pap smears were performed, of which 64% were normal. The percentage of Pap smears that yielded adequate specimen material improved from 82% to 91%, an improvement we attributed to feedback the system provided to physicians. Overall, Pap smear results and follow-up appeared in the medical record of 94% of patients who had abnormal findings. However, during the second year, the quality assurance system detected a deterioration in documentation of results and follow-up plans that coincided with moving the practice to a new facility. The operating cost for this program was approximately $950 per year. CONCLUSIONS: Quality assurance programs can effectively monitor physicians' performance in dealing with abnormal Pap smears, can detect deteriorations in performance, and can improve some aspects of performance through feedback reporting to physicians.

Family Practice↗
PubMed1990

Isolation and characterization of temperature-sensitive mutants of Streptococcus suis: efficacy trial of the mutant vaccine in mice.

A model of experimental Streptococcus suis infection was developed in young mice. Minimum lethal dose (MLD) values were calculated for four virulent serotypes (1/2, 1, 2, 3) of S. suis using this model. Temperature-sensitive (ts) mutants of S. suis serotypes 1/2 and 1-8 were isolated and characterized on the basis of their growth kinetics and reversion rates. Ts mutants of S. suis 1/2, 1, 2, and 3 were tested as vaccines against the virulent homologous and heterologous challenges in mice. The protection provided was evaluated by analyzing the clinical signs, death or survival. Homologous but not heterologous protection was noted in all mice vaccinated with the mutant strains. Ts mutants of S. suis 1/2 provided 100% protection against challenge by virulent strains of S. suis 1/2, 1, and 2.

Animals↗