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Biomedical subjects

K L Vosti

Publications and source records attributed to K L Vosti.

At least 19 recordsLinked to original sources
PubMed1999

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.

California↗
PubMed1998

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.

Adult↗
PubMed1997

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.

California↗
PubMed1995

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.

Adolescent↗
PubMed1984

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.

Aortic Valve↗
PubMed1979

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.

Anti-Bacterial Agents↗
PubMed1979

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.

ABO Blood-Group System↗
PubMed1978

Bacterial infections in pediatric Hodgkin's disease: relationship to radiotherapy, chemotherapy and splenectomy.

The occurrence of bacterial infections (B.I.) among 181 children with Hodgkin's disease (121 with splenectomy, 60 without splenectomy) was analyzed. Twenty-seven B.I. occurred among 22 children and included 15 episodes of bacteremia-meningitis in 14 children. B.I. occurred in all age groups, but bacteremia-meningitis occurred most commonly in splenectomized children 10 years of age or less. The frequency of B.I. in splenectomized children receiving radiotherapy was 1.4%, compared to 18.3% among those receiving chemotherapy (p less than 0.05); the frequency of B.I. among non-splenectomized children receiving radiotherapy was 2.8%, compared to 23.1% among those receiving chemotherapy (p less than 0.05). There was no difference in the probability of B.I. as a function of splenectomy for the corresponding groups, although all cases of Streptococcus pneumoniae and Hemophilus influenzae bacteremia-meningitis in splenectomized children. Overwhelming postsplenectomy bacteremia infection not related to active disease or treatment occurred in 3/121 (2.5%) children, accounting for only one fatality (0.8%).

Adolescent↗
PubMed1978

Factitious and fraudulent fever.

The task of elucidating the etiology of fever of undertermined origin remains a major undertaking. Factitious fever is uncommonly considered of major importance in the differential diagnosis of fever of undetermined origin although it is a readily identifiable, syndrome and one that is easily excluded one it has been considered. Early identification may reduce the necessity for prlonged, expensive and potentially hazardous hospitalizations for such patients. A retrospective study identified 2.2 per cent (11 of 506) of all patients whose fever on their charts was coded as fever of undetermined origin as having factitious fever. These patients either created factitious fever by manipulation of the thermometer or fraudulent fever by self-induced means. A review of the literature yielded an additional 70 cases in which fever was either the sole factitious sign or part of a larger, more complex factitious illness. Patients were typically young, female and often associated with the medical profession. Patients with factitious fever differ from those with the stereotyped Munchausen's syndrome and may be difficult to recognize. Signs leading to the recognition of this syndrome are emphasized. Since the nature of the psychiatric illness may vary from patient to patient, early discovery may facilitate psychiatric intervention as such patients may be more amenable to therapy.

Adolescent↗
PubMed1978

The characteristics of M proteins purified by column chromatography with hydroxyapatite from acid extracts of Streptococcus pyogenes of types 1, 3, 6, 12 and 17.

Purified M proteins were recovered from acid extracts of Streptococcus pyogenes, M-types 1, 3, 6, 12 and 17, by elution from columns of hydroxyapatite of the proteins precipitated with ammonium sulphate. M protein free from non-type-specific antigens was recovered only from M-type 12. Although similar fractions were not recovered from M-types 1, 3, 6 and 17, purified preparations containing a single cross-reactive antigen were obtained. In addition to the M proteins associated with cross-reactive antigens, type-specific antigens that did not stimulate opsonic antibodies were isolated from revealed molecular weights that ranged from 32,000 to 63,000 daltons, total amino acid compositions that were similar, and N-terminal amino acids that were variable.

Amino Acid Sequence↗
PubMed1978

Extraction of streptococcal type 12 M protein by cyanogen bromide.

Conditions for the release of streptococcal type 12 M protein from whole cells by cyanogen bromide are described; they demonstrated that methionine is not essential to the structural arrangements which account for some of its immunological and biological properties. The released M protein was separated from other proteins by column chromatography with hydroxylapatite. The type-specific molecules which reacted with precipitating antibodies were found only in the 0.3 M eluate, formed zones with mobilities less than 12% of that of the dye front on electrophoresis in the standard acrylamide disc gel system, formed at least four bands in sodium dodecyl sulfate-acrylamide disc gels with molecular weights ranging from 12,000 to 23,000, and stimulated the formation of opsonic antibodies in rabbits. Cyanogen bromide provides a highly specific method for the release of M proteins which should prove particularly useful in analyses of structural-functional relationships among different M proteins.

Amino Acids↗