Outcome measurement in postgraduate year one of graduates from a medical school with a pass/fail grading system.

PURPOSE: To measure the performances of first-year residents who had graduated from a medical school with a pass/fail grading system and to compare the preparedness of these graduates with that of their peers. METHOD: All 169 graduates of Stanford University School of Medicine's classes of 1993 and 1994 were included in this study. First-year program directors rated the performance of each Stanford graduate in 11 areas, compared the graduate's clinical preparedness with that of his or her peer group, and rated the accuracy of the dean's letter in presenting the graduate's capabilities. RESULTS: Responses were obtained for 144 of the 169 graduates (85%). The program directors rated the overall clinical competencies of most of the graduates as "superior" (76%) or "good" (22%); they rated very few as "unsatisfactory" (2%). When the Stanford graduates were compared with their peers, their clinical preparedness was judged "outstanding" (33%), "excellent" (44%), and "good" (20%); very few were judged "poor" (3%). Stratification of programs by either hospital or medical specialty did not reveal significant differences in overall clinical competence. Ninety-one percent of the responses reported that the dean's letters had accurately presented the capabilities of the graduates. CONCLUSION: Graduates from a medical school with a two-interval, pass/fail system successfully matched with strong, highly-sought-after postgraduate training programs, performed in a satisfactory to superior manner, and compared favorably with their peer group.

Recurrent group B streptococcal arthritis.

Bacterial arthritis caused by group B beta-hemolytic streptococci (GBS) is uncommonly encountered. We report a woman who had three documented isolated recurrences of GBS arthritis (right hip, right knee x 2) over a period of three years which were successfully treated. One year before the first episode, the patient was found to have squamous cell carcinoma of the cervix stage IIIB and underwent extensive combined oncological treatment. The extensive chemoradiotherapy and anatomical changes resulting from cancer of the cervix are believed to have contributed to the occurrence and recurrence of invasive group B streptococcal infection in this patient which is the first one reported with recurrent GBS arthritis.

Bacterial arthritis due to beta-hemolytic streptococci of serogroups A, B, C, F, and G. Analysis of 23 cases and a review of the literature.

The clinical features, essential laboratory findings, management, and outcome of all 23 cases of septic arthritis caused by different serogroups of beta-hemolytic streptococcus (BHS) seen at the Stanford Medical Center, Stanford, CA, from July 1, 1985, through October 31, 1996, were reviewed and compared to those found in the literature. Group A streptococci (GAS) accounted for 9 (40%) of our cases; group B (GBS), for 7 (30%); and Group G (GGS), for 7 (30%). No cases were caused by Group C (GCS) or F (GFS) during this period. During the same period, GAS accounted for 66 (33%) of 200 cases of bacteremia due to BHS, GBS, for 98 (49%); GCS, for 12 (6%); GFS, for 4 (2%); and GGS, for 20 (10%). A review of potential risk factors revealed that, with the exception of GGS, male and female patients were almost equally distributed among each of the serogroups. Patients aged 50 years and older comprised 56%-77% of each group. Associated conditions and risk factors were present among most patients (19/23, 83%); autoimmune diseases and a chronic skin wound or trauma were notably present among patients with GAS, while diabetes mellitus and malignancy were more common among patients with GBS. Infected prosthetic implants were present in 7 patients, including 4/7 patients with GGS. All patients had positive cultures of synovial fluid, and 11/23 (49%) had positive blood cultures (GAS, 5/9; GBS, 6/7; and GGS, 0/7). The clinical presentation and hospital course of patients infected with the different serogroups varied. Patients infected with GAS had the most severe disease and those with GGS the least severe. Necrotizing fascitis, shock, DIC, and admission to the intensive care unit were found only among patients infected with GAS. Despite aggressive management with antimicrobial therapy and surgery, 4/23 patients died (3 patients with GAS; 1 with GBS). The isolates from our patients were not available for study; investigations by others of the biology of BHS suggest that the production of 1 or more of the streptococcal pyrogenic exotoxins by isolates of GAS may account for the differences in the severity of disease among our patients with septic arthritis caused by different serogroups of BHS. Although septic arthritis due to BHS is uncommon, such patients provide a valuable model to study features of the host-parasite interaction that may contribute to the observed differences in severity of disease.

The relationship of clinical knowledge to months of clinical training among medical students.

PURPOSE: To assess the correlation of the number of months of clinical training with clinical knowledge, as measured by the United States Medical Licensing Examination (USMLE) Step 2. METHOD: The total number of months of clinical training and percentile scores on USMLE Step 2 were determined for 217 Stanford. University School of Medicine graduates from 1992 through 1994. Percentile scores on each subsection of the Medical College Admission Test (MCAT) and the National Board of Medical Examiners Part 1 or USMLE Step 1 (Part 1/Step 1) for the graduates were also determined. For some analyses the graduates were separated into three groups according to the duration of clinical training. The Pearson product-moment correlation coefficient was used to quantify and define the significance of correlations. The Jorickheere-Terpstra nonparametric test was used to assess trends across the three groups. A multiple linear regression model was used to test the effects of confounding variables. RESULTS: The total numbers of clerkship months ranged from 12 to 23; the median was 18. A highly significant correlation was found between increasing months of clinical training and increasing scores on Step 2 (p = .002); a weaker significant correlation was found with scores on Part 1/Step 1 (p = .03). The correlation for Step 2 scores did not diminish appreciably (p = .004) when scores for Part 1/Step 1 and each MCAT subsection were introduced into the regression model. CONCLUSION: A highly significant correlation was found between the amount of clinical training and the acquisition and utilization of clinical knowledge. In the current climate of concerns about the rising costs of medical education, the impulse to solve these concerns by decreasing the amount of medical students' clinical training should be approached with caution.

Group B streptococcal bacteremia in adults. Five years' experience and a review of the literature.

The importance of group B streptococcus (GBS) as a cause of serious infectious disease among adults is not widely appreciated. In adults, the modes of acquisition and transmission are unknown. Since most hospital-based studies of GBS bacteremia in adults consist of small numbers of patients, the clinical spectrum of disease is not well described. Our retrospective study reviews the clinical features, antimicrobial therapy, and risk factors for mortality of 32 adult patients (18 women and 14 men) with GBS bacteremia and compares the proportion of isolates from the different beta-hemolytic streptococci sero-groups. We found that 39% of isolates from adult blood cultures were group B, a frequency nearly identical to that of group A streptococcal bacteremia. Most (66%) adult patients were more than 50 years old. Primary bacteremia was the most frequent clinical diagnosis, occurring in 7 (22%) of 32 patients. Nonhematologic cancer was the most frequently associated condition (25%). Nineteen percent of the patients had diabetes mellitus. The overall mortality rate was 31% and was significantly associated with increasing age. Our results are compared to those obtained by a review of all 5 previous comparable studies and demonstrate that GBS bacteremia is a serious infection in adults with increased mortality related to advancing age.

Gal-Gal binding and hemolysin phenotypes and genotypes associated with uropathogenic Escherichia coli.

To determine whether uropathogenic strains of Escherichia coli exhibit a distinctive constellation of phenotypes, we examined 44 urinary isolates from women with radiologically normal urinary tracts and pyelonephritis, cystitis, or asymptomatic bacteriuria and 73 fecal isolates from healthy control subjects. The strains were characterized by their O serogroup, by their binding specificity (as determined by adhesins), and by their production of hemolysin and colicin V. In addition, the strains were assessed for homologous gene sequences by means of DNA-hybridization probes prepared from cistrons that encode hemolysin and the Gal-Gal binding adhesin--two determinants of virulence, which cause tissue injury and promote bacterial colonization of uroepithelia, respectively. In contrast to most isolates from normal feces and from the urine of patients with asymptomatic bacteriuria, pyelonephritis strains belong to a small number of O serogroups; all express the Gal--Gal binding adhesin and 75 per cent are hemolytic. A gene probe for the Gal--Gal binding adhesin, derived from the chromosome of one strain from a patient with pyelonephritis, hybridized with the DNA of all other pyelonephritis strains. The probe for the hemolysin gene hybridized with DNA from all other hemolytic strains. These data indicate that most cases of pyelonephritis are due to a small number of pathogenic clones that express critical determinants of virulence, and that the nucleotide sequences for hemolysin and the Gal--Gal binding adhesin in heterologous strains share homology. We are tempted to speculate that the gene products of these shared regions of the genome might form the basis for a vaccine against pyelonephritis.

Open trial of imipenem/cilastatin therapy for serious bacterial infections.

Imipenem is a new beta-lactam antibiotic with a wide spectrum of activity against gram-positive and gram-negative aerobic and anaerobic bacteria. The efficacy and toxicity of this drug, when administered parenterally in combination with the dehydropeptidase I inhibitor cilastatin, were studied in 41 hospitalized patients with serious infections. Clinical cure was achieved in 26 (79%) of the 33 patients who could be evaluated and microbiologic cure in 23 (85%) of the 27 patients who could be evaluated. Adverse clinical or laboratory reactions were observed in seven (17%) of the 41 patients. Thus, imipenem/cilastatin was highly effective in the treatment of a wide variety of serious bacterial infections.

Prosthetic valve endocarditis caused by Legionella pneumophila.

Prosthetic valve endocarditis due to Legionella pneumophila occurred in a woman who had aortic and mitral valve replacements with porcine xenografts. During surgery for persistent fever and aortic regurgitation due to presumed endocarditis, she had vegetations involving both the aortic and mitral valve prostheses with a circumferential abscess of the aortic annulus. Cultures, Dieterle stain, and direct fluorescent antibody stain of valve tissue, and subsequent measurements of serum antibody levels confirmed L. pneumophila as the infecting organism. This infection occurred in the absence of pneumonia. Legionella pneumophila must be considered a potential cause of culture-negative prosthetic valve endocarditis and should be sought in appropriate clinical circumstances.

Response to pneumococcal vaccine among children with Hodgkin's disease.

Nineteen children with Hodgkin's disease were immuized with dodecavalent pneumococcal vaccine; the efficacy of vaccination, the duration of response, and the significance of the time of immunization in relation to splenectomy and subsequent irradiation and chemotherapy were investigated. Eight children were immunized before splenectomy, and 11 were immunized after splenectomy, irradiation, and chemotherapy. All children were irradiated, and all but two received chemotherapy with MOPP (nitrogen mustard, vincristine sulfate, procarbazine, and prednisone). Sera were assayed for antibodies to the 12 polysaccharide types in the vaccine. The group of children immunized before splenectomy had a significant antibody response to 67% of the antigens tested, whereas the group immunized after splenectomy responded to 40% of the antigens (P less than 0.0001). The duration of response was variable. Pneumococcal vaccine was more likely to provoke an immunologic response if administered before splenectomy than if administered after splenectomy, irradiation, and chemotherapy; however, the response was not uniform. A response to one antigen did not necessarily imply a response to other antigens. In the absence of a readily available assay to determine a protective antibody response, one cannot rely on the vaccine as the sole means of preventing pneumococcal infections in asplenic children with Hodgkin's disease.

Relationship of hemagglutination to other biological properties of serologically classified isolates of Escherichia coli.

The ability of 170 serologically classified strains of Escherichia coli to agglutinate human erythrocytes was examined. Erythrocytes of blood group A were more sensitive indicators of this property than were those of groups B or O. The predominant receptor was shown to be mannose containing; however, an additional receptor was found in two of nine strains studied. Natural mannose-like inhibitors were not found in unconcentrated urine obtained from 12 humans. Isolates from the urine or blood of patients with infections agglutinated erythrocytes significantly more frequently than did isolates from feces. Urine isolates of 10 common serogroups and isolates of less common serogroups did not differ in their ability to agglutinate erythrocytes. Among isolates from the urine of patients with infections, the ability to agglutinate erythrocytes did not correlate with either the serogroup of the strain or the clinical syndrome of the patient. Of the several other biological properties that were examined, only the production of colicins showed a significant association with the ability to agglutinate human erythrocytes.

Comparison of a micromethod for performance of the serum bactericidal test with the standard tube dilution method.

A micromethod for performance of the serum bactericidal test is described, and the results obtained with this method are compared with those obtained with the standard tube dilution macromethod. An agreement within +/- 1 dilution was achieved in 23 of 25 (92%) determinations of the serum bactericidal titer. The micromethod used approximately one-third of the amount of pooled normal human serum and of the technician's time required for performance of the macromethod. The micromethod offers an accurate and economical alternative to the macromethod for the performance of the serum bactericidal test and is particularly useful with infants and children since it minimizes blood loss.