Resistance of differentiated human airway epithelium to infection by rhinovirus.

Virtually all in vitro studies of the effects of rhinovirus on human airway epithelium have used cells grown under conditions known to produce low levels of differentiation. The relevance of the results to native epithelium is questionable. Here we grew primary cultures of human tracheal or nasal epithelium under three conditions. One condition produced pseudostratified, mucociliary cells virtually indistinguishable from native epithelium. The other two conditions produced undifferentiated squamous cells lacking cilia. Cells were infected for 6 h with rhinovirus-16. After a 24-h incubation period, we determined levels of viral RNA in the cells, numbers of infectious viral particles released in the mucosal medium, expression of a variety of epithelial cytokines and other proteins, release of IL-6 and IL-8, and transepithelial electrical resistance and voltage. After infection, levels of viral RNA in the poorly differentiated cells were 30 or 130 times those in the differentiated. Furthermore, expression of mRNA for inflammatory cytokines, release of infectious particles, and release of IL-6 and IL-8 were closely correlated with the degree of viral infection. Thus well-differentiated cells are much more resistant to viral infection and its functional consequences than are poorly differentiated cells from the same source.

Effects of media on differentiation of cultured human tracheal epithelium.

The purpose of the this study was to find media that supported high levels of differentiation in primary cultures of human tracheal epithelium. We tested six previously described, partially defined media and three nondefined media. Cells were grown with an air interface on porous-bottomed inserts, and differentiation was assessed from electrophysiological properties, levels of total protein and deoxyribonucleic acid, and histology. In all media, cells polarized and developed tight junctions, as assessed from transepithelial electrical resistance and were better differentiated at 14 d after plating than at 7 d. The partially defined media described previously by Gray et al. (Am. J. Respir. Cell. Mol. Biol. 14:104-112; 1996) and Matsui et al. (J. Clin. Invest. 102:1125-1131; 1998) and an undefined medium containing Ultroser G serum substitute produced the most highly differentiated epithelial cells, as revealed by a high short-circuit current (I(sc)) and a ciliated, pseudostratified appearance. In other media, cells tended to be either squamous or stratified squamous, with I(sc) levels <25% of those obtained with the three optimal media. Though no key factor in the composition of the partially defined media could be identified, two of the four media with high concentrations of retinoic acid produced good differentiation. In contrast, the two media with the lowest [Ca] (0.11 mM) produced poorly differentiated cells, as did the two partially defined media with low or no retinoic acid concentration.

Effects of growth surface on differentiation of cultures of human tracheal epithelium.

Optical measurements from epithelial cells grown on clear solid surfaces (e.g., coverslips, petri dishes) are often compared with other measurements (e.g., short-circuit current; I(sc)) obtained from cells grown on opaque porous surfaces (inserts). However, the relative levels of differentiation of cells grown under the two conditions are usually unknown. To address this issue, we grew primary cultures of human tracheal epithelium on solid surfaces or on porous inserts and compared their total levels of protein and deoxyribonucleic acid, electrical properties in Ussing chambers, and ultrastructure. To measure ion transport across cells grown on solid supports, cells were grown on inserts placed on parafilm. Later, separation of insert from parafilm allowed the cells' I(sc) to be measured in Ussing chambers. Four different media were used. Cells grown in one medium showed very low levels of differentiation on all growth supports. In the other media, growth on inserts markedly enhanced differentiation as compared with solid supports. Baseline I(sc) of cells grown on either clear or opaque inserts was at least 30 times greater than that of cells grown on solid supports, though I(sc) with clear inserts averaged approximately 30% lower than that with opaque inserts. We conclude that though differentiation of cells may vary slightly depending on the insert used, cells on any type of insert are much better differentiated than cells grown on solid surfaces. Thus, it is both possible and desirable to make all functional measurements on cells grown on clear porous supports.

Comparison of upper-extremity balance tasks and force platform testing in persons with hemiparesis.

BACKGROUND AND PURPOSE: The purpose of this study was to investigate the relationship between clinically accessible functional balance tools and sophisticated force platform measures in a standing position. SUBJECTS: Twenty persons who had hemiparesis secondary to a stroke and were ambulatory (mean age = 57.9 years, SD = 13.6, range = 35-79) were evaluated during a single testing session. METHODS: Performances on self-generated upper-extremity balance tasks using the nonparetic side (Functional Reach Test [FRT], arm raise and arm reach tasks) were compared with responses to external perturbations on the Balance System (postural sway, symmetry of weight distribution). RESULTS: No relationship was found between the upper-extremity balance tests and the force platform measures of postural sway. After suppressing the effect of age by means of partial correlation coefficients, the FRT was correlated with measures of postural symmetry in parallel stance on the Balance System (r = .66-.78). The FRT was only moderately correlated with the arm raise and arm reach tasks (r = .43 and .44). CONCLUSION AND DISCUSSION: Postural sway in response to force platform perturbations may have little relation to the postural control necessary for self-generated upper-extremity balance tasks. In contrast, the FRT and the force platform measures of postural symmetry appear to be evaluating comparable standing-balance abilities in persons with hemiparesis. The modest relationship between the FRT and the arm raise and arm reach tasks limits the finding's clinical relevance.

Declining class size and the decline in graduates choosing family medicine.

In light of the major concern about the marked decline in the numbers of graduates from U.S. medical schools who are entering family medicine, the authors analyzed the effect of declining class size on the numbers of graduates entering family medicine residencies. Data were analyzed from ten years of graduating classes (1981-1990) from the 81 medical schools graduating the most family physicians. The analysis confirmed that declining class size is related to the decline in the production of family physicians. In particular, the 31 schools with the largest declines in the numbers of graduates overall (from the early 1980s compared with the late 1980s and 1990) demonstrated as a group a large fall (nearly 25%) in the production of family physicians. The authors conclude that the large reductions in class size in many medical schools are associated with even larger reductions in the numbers of future family physicians being graduated from U.S. medical schools.

Utilization of allied health personnel in HMOs.

Health Maintenance Organizations (HMOs) have become a significant component of the health care delivery system and thus provide employment opportunities for allied health professionals. This study investigated the utilization of selected allied health services and personnel in a national sample of HMO settings. Significant utilization of allied health services were reported both through provision of services in-house and through contractual arrangements. Smaller HMOs tended to use several allied health services in-house, while larger HMOs used both in-house and contractual services. Younger HMOs tended to utilize contractual arrangements while older HMOs utilized in-house services. Staff and group HMOs tended to have the highest utilization of health manpower with the larger, older HMOs employing more of those personnel.

Effects of sodium valproate and oxygen on the CD-1 mouse fetus.

This study reports the effects of valproic acid (VA) on the CD-1 mouse fetus when the drug is administered continuously via osmotic minipumps at human therapeutic drug plasma levels. Two VA-filled Alzet osmotic minipumps were implanted subcutaneously on gestation day 5 for continuous exposure of a total daily dosage of 850 mg/kg on gestation days 5-12. Dams were then exposed continuously to either normoxic (21% oxygen), hyperoxic (50% oxygen), or hypoxic (12% oxygen) controlled environments during gestation days 5-12, in order to determine if hyperoxic maternal conditions offered a protective environment for the fetus, and conversely, if hypoxia exacerbated teratogenicity. Dams were sacrificed on gestation day 18, and litter and fetal data were collected. It was determined in separate groups under normoxic conditions that the osmotic minipump system maintained VA plasma levels corresponding to human therapeutic levels. Sodium valproate was found to induce developmental toxicity in the CD-1 mouse fetus at human therapeutic drug plasma levels. Fetal weights were reduced, and the number of resorptions, deaths, and hematomas was increased. While hypoxia exacerbated the toxic effect on the fetus, hyperoxia failed to ameliorate the outcome.

Independent study: 10-year programme review.

The Ohio State University College of Medicine has offered an independent study curricular option since 1970. This study reports our experience covering 10 entering classes and compares the independent study programme (ISP) students to the students who entered the traditional lecture-discussion programme (LDP). It looks at (a) entering demographic and personality characteristics, (b) academic, clinical and research performance during school and at graduation and (c) practice and career outcomes. The major findings are that, as groups, students from the two curricular programmes are far more alike than different but that the flexibility of an independent study programme provides special options without loss of academic achievement. Individual talents and interests were enhanced and research opportunities have aided recruitment and development of particular students. Independent study students pursued more research during medical school and hold more full-time academic positions in practice. A comparative cost study showed that, once the two programmes are operational, per student operational costs are equivalent. Results of this study indicate, that at Ohio State, the benefits of a two-track system outweigh the additional costs.

Nurses as evaluators of the humanistic behavior of internal medicine residents.

The reliability of a 13-item questionnaire designed to assess the humanistic behaviors of internal medicine residents and the reliability of nurses as raters of those behaviors were examined. Twenty-five residents were evaluated by 10 or 11 nurses on two general medicine services and on cardiology and hematology-oncology services in a large, highly specialized department of internal medicine. Using an application of generalizability theory, which extends beyond classical test theory to establish estimates of multiple-error sources, the investigators calculated reliability-like coefficients for each of the services. The coefficients were .95 and .85 for the two general medicine services, .67 for cardiology, and .88 for hematology-oncology. These findings indicate that the questionnaire is a reliable instrument for assessing humanistic behavior and identifying reliable raters in groups of nurses.

Sexually transmissible infectious agents in sexually active and virginal asymptomatic adolescent girls.

Sixty-eight sexually active and 52 virginal adolescent girls were evaluated for six sexually transmissible infectious agents: Gardnerella vaginalis, Ureaplasma urealyticum, Mycoplasma hominis, Chlamydia trachomatis, Trichomonas vaginalis, and Neisseria gonorrhoeae. There were significant differences between sexually active and virginal girls with respect to the prevalence of isolation of U urealyticum (75% v 33%, P less than .005), M hominis (27% v 10%, P less than .05), and C trachomatis (19% v 2%, P less than .025) but not for G vaginalis (34% v 17%, P = .09). N gonorrhoeae and T vaginalis were isolated exclusively from sexually active girls, but their low prevalence (6% and 9%, respectively) made the difference statistically insignificant (P = .2 and .06, respectively). Race, current v previous sexual activity, multiple sexual partners, oral contraceptive use, and concurrent isolation of another organism did not identify those at increased risk for chlamydial isolation. Such girls were significantly more likely to have inflammatory Papanicolaou smears (36% v 10%, P less than .05) and excessive WBC in their vaginal secretions (50% v 19%, P = .05). The data support the contention that C trachomatis, N gonorrhoeae, and T vaginalis are organisms that are predominantly acquired via sexual routes. Significant nonsexual modes of transmission are supported by the data for the genital mycoplasmas and G vaginalis. Finally, a history of sexual activity in an adolescent female warrants specific diagnostic testing for Chlamydia.

A comparison of medical students' performances in independent study and traditional programs.

Medical students at Ohio State University may study the basic medical sciences in an independent study program or in a conventional lecture-discussion program. In a study involving more than 2,000 students over a 10-year period, students pursuing the independent study program and students in the more traditional program performed similarly on Part I of the National Board of Medical Examiners (NBME) examinations and in their required clerkships. However, differences were identified in some content areas and resulted in curricular changes.

Vestibular and visual rotational stimulation as treatment for attention deficit and hyperactivity.

Previously published studies report an improvement in hyperactivity following exposure to vestibular semicircular canal stimulation under eyes-open, lights-on conditions (conditions that provide visual feedback). To separate the effectiveness of vestibular stimulation from that of visual stimulation, 30 primary school children who met the criteria for having attention deficit disorder with hyperactivity were enrolled in a split-sample Latin square crossover study. The effects of just vestibular stimulation and of just visual stimulation were compared with the effect of combined vestibular and visual stimulation. Behavior ratings showed significant improvement at the end of the last treatment and at follow-up one year later; this is not easily explained by statistical regression, history, or the placebo effect. The most improvement was with solitary vestibular stimulation, which showed large effect sizes; however, differences from the other two conditions failed to reach significance at traditional p levels.

Elective modules in the behavioural sciences.

An elective modules programme in the behavioural sciences was designed for the undergraduate medical curriculum at The Ohio State University College of Medicine. The programme provides a mechanism by which a broad range of behavioural science content can be introduced into the curriculum without increased allocation of teaching staff or budget. Student preference data indicate some clear differences with the more popular modules being those which focus on skills or behaviours that students perceive to be useful in the immediate practice of medicine. The elective aspect of the programme was part of its initial appeal, both to students and teaching staff. Two years of course evaluation data from the students indicate that most individual modules and the programmes as a total have been successful in achieving their intentions. The programme has now been included as a permanent component of the curricula.

Clinical instruction in medicine: a national survey.

In this paper the authors report on the medicine phase of three parallel studies undertaken to investigate clinical teaching skills in medicine, dentistry, and nursing. The intent of the overall study was to gather and assess broad-based information useful in the design and implementation of clinical teaching improvement programs in the health sciences. A 14-member consortium representing five schools each in medicine and dentistry and four in nursing collaborated by using a modified Delphi technique to resolve conflict and differences, through group judgments, in preferences to choices among educational goals and activities. Based upon an educational needs assessment, the design of the study and of the research methodology allows replication at individual institutions and provides a systematic approach for designing and implementing faculty development programs with specific skill emphasis at the clinical level.

Health care team training in U.S. and Canadian medical schools.

This paper reports the results of a survey to determine the extent to which interdisciplinary health team concepts are being taught as part of the undergraduate curriculum in U.S. and Canadian medical schools. Less than a third (29 percent) of the respondents indicated the existence of a formal program or program component designed to teach health care team skills. Although the total number of reported programs is small, 53 percent of these programs were required for all students. Three overall categories of content taught within the programs included group process skills, role and function of the team and its members, and content related to the health care context. Although the team approach is a process orientation, fewer than half of the programs reported using direct application of the process, that is, building groups of students into teams.

Brain tumors in childhood.

A review of the pathology of 689 neuroectodermal tumors occurring over a 30-year period at The Hospital for Sick Children in Toronto has underlined the importance of examining the tissue from each tumor in order to insure consistency and accuracy in histological diagnosis. The age, sex, histology and topographical distribution of this series of tumors is compared with other series and discussed in detail. The high proportion of tumors occurring in early childhood, the striking male preponderance, and the high incidence of astrocytomas, medulloblastomas and ependymomas is emphasized.