Evaluating an alternative funding plan

There have been increasing levels of interest shown across Canada in the potential application of alternative funding arrangements for academic health science centres. This article outlines the approach, and some preliminary results, of the alternative funding plan evaluation at Queen's University. Following a discussion of the AFP itself, the article describes the first phase of the evaluation process. Several studies nearing completion are outlined, as are other pieces of research that will be conducted before the AFP is renegotiated in 1999. Finally, the authors provide a brief discussion of the organizational and methodological issues that emerge when evaluating an AFP.

Prevalence and associations of MRI-demonstrated brain infarcts in elderly subjects with a history of transient ischemic attack. The Cardiovascular Health Study

BACKGROUND AND PURPOSE

MRI is more sensitive than CT, but the significance of brain abnormalities seen on MR images obtained in older subjects with transient ischemic attack (TIA) is not clear. We studied the prevalence and risk factors associated with MRI-demonstrated infarcts in elderly subjects with a history of TIA.

METHODS

Participants of the Cardiovascular Health Study, aged 65 years or more and without prior stroke, were studied with brain MRI (n=3456). The prevalence of brain infarcts (>/=3 mm) on MRI was determined in subjects with and without TIA. The cardiovascular risk factors and clinical and subclinical cardiovascular disease associated with MRI infarcts were studied in subjects with TIA.

RESULTS

Subjects with TIA (n=100) had a higher prevalence of MRI infarcts than subjects without TIA (46% versus 28%; P<0.001). The unadjusted odds ratio for having MRI infarcts in subjects with TIA was 2.20 (95% CI, 1.47 to 3.30) and remained significantly elevated after adjustments for risk factors and cerebrovascular disease (odds ratio, 1.86; 95% CI, 1.23 to 2.83). In subjects with TIA, diastolic blood pressure (P=0.01) and internal carotid artery intima-media thickness (P=0.01) were the only factors predictive of the presence of MRI infarcts by stepwise logistic regression analysis.

CONCLUSIONS

MRI infarcts are imaging manifestations of clinically important cerebrovascular disease in subjects with a history of TIA, given their increased prevalence and positive association with increased diastolic blood pressure and internal carotid artery intima-media thickness.

Early adolescents' perceptions of cigarette smoking: a cross-sectional survey in a junior high school

Most adult cigarette smokers start smoking during adolescence. Since youths' perceptions of cigarette smoking may influence their decision to smoke, it is important to understand early adolescents' feelings about, and information sources regarding, smoking. In the present study, a cross-sectional survey, conducted in an urban junior high school, asked students in grades six to eight about their attitudes toward cigarette advertising, their perception of the harmful effects of cigarette smoking, and their sources of information. One hundred students completed the questionnaire, 12 of whom were current or former smokers. Approximately 27% believed cigarette advertising significantly influenced their classmates or themselves. Ninety percent recognized that cigarette smoking was seriously harmful. The source of this information was mainly teachers and parents. While 53% of the students identified their parents as the ones who taught them not to smoke, 47.8% of these parents were smokers themselves. Only 2% of the students indicated that they received information about the effects of smoking from health providers.

Differential expression of keratins 10, 17, and 19 in normal cervical epithelium, cervical intraepithelial neoplasia, and cervical carcinoma

AIM

To examine the value of immunohistochemistry in defining a keratin profile to aid cervical histopathological diagnosis.

METHODS

Immunohistochemical localisation of keratins 17, 10, and 19 was studied in 268 cervical biopsies from 216 women including normal epithelia (with and without human papilloma virus), low and high grade cervical intraepithelial neoplasia, and invasive carcinoma. The percentage of positive immunostaining was scored using a Kontron MOP videoplan image analyser.

RESULTS

All major categories of cervical epithelia expressed these keratins to varying degrees. The median percentage of immunostaining for keratin 10 was 40% in normal tissue compared with just 1% in invasive carcinoma (p < 0.0001). The medians for keratin 17 were 0% in the normal group and 80% in carcinomas (p < 0.0001). By contrast, there was no significant difference in staining for keratin 19. Using a combination of the keratin 10 and 17 percentages, it was possible to separate the carcinomas from the benign conditions with a sensitivity of 100% and a specificity of 93%. Further analyses within the groups revealed more extensive staining for keratins 10 and 19 in reserve cell hyperplasia, immature squamous metaplasia, and congenital transformation zone.

CONCLUSIONS

The morphological variety within the cervix is reflected, in part, by distinct keratin patterns. There are striking differences in the patterns of keratins 10 and 17 between infiltrating squamous carcinoma and normal cervical epithelia.

Use of the 6-methylsalicylic-acid-synthase gene as a discriminating marker between Aspergillus terreus and Aspergillus flavipes

In nineteen pathogenic and saprophytic isolates denoted as Aspergillus terreus the presence and restriction pattern of the gene pksM (6-methylsalicylic acid synthase) was determined. Five patterns (A-E) were found and in three isolates the gene was missing. The RAPD (Random Amplified Polymorphic DNA) patterns with three primers were analyzed. The strains with pksM pattern possibly derived from the most common pattern A by single mutation (patterns B-D) were also related by RAPD. Among them, three clades were found. The first one contained saprophytes from Asia, the other two clades contained both European and American pathogens and each of them one saprophyte. The sequences of rDNA region containing 5.8S rDNA and spacers ITS1 and ITS2 were established for representatives of each group and the strains missing the pksM gene. The isolates possessing pksM (although with different restriction patterns) grouped as A. terreus group, whereas the isolates lacking this gene were close to Fennellia flavipes.

Interaction between paired-pulse facilitation and long-term potentiation in the projection from hippocampal area CA1 to the subiculum

Studies of the interaction between long-term potentiation (LTP) and paired-pulse facilitation (PPF) may throw light on the role of presynaptic factors in LTP. We examine here, for the first time, the nature of PPF in the CA1-subiculum projection. PPF peaks at a 50 ms interstimulus interval (ISI) and is evident at ISIs from 10 to 500 ms. There is no PPF effect at a 1000 ms ISI. PPF decreases in magnitude post-LTP induction across the middle range of ISI values tested (30, 50 and 100 ms). There is a positive correlation between initial PPF values and LTP; this correlation increases as the ISI increases. Initial values and the change in PPF post-LTP are also negatively correlated.

Removal of asymptomatic third molars: indications, contraindications, risks and benefits

The removal of third molar teeth is one of the most common surgical procedures performed by dentists in the United States. Although prophylactic removal of third molars is supported by many to prevent disease, the removal of asymptomatic third molars should be based upon individual clinical and radiographic assessment of each patient. After educating the patient as to the indications, contraindications, risks, and benefits of removal of third molars, the patient and dentist should reach a mutual decision as to whether to proceed with surgery.

A relic S-RNase is expressed in the styles of self-compatible Nicotiana sylvestris

We surveyed ribonuclease activity in the styles of Nicotiana spp. and found little or no activity in self-compatible species and in a self-compatible accession of a self-incompatible species. All self-incompatible species had high levels of ribonuclease activity in their style. Interestingly, one self-compatible species, N. sylvestris, had a level of stylar ribonuclease activity comparable to that of some self-incompatible Nicotiana species. A ribonuclease with biochemical properties similar to those of the self-incompatibility (S-)RNases of N. alata was purified from N. sylvestris styles. The N-terminal sequence of this protein was used to confirm the identity of a cDNA corresponding to the stylar RNase. The amino acid sequence deduced from the cDNA was related to those of the S-RNases and included the five conserved regions characteristic of these proteins. It appears that the N. sylvestris RNase may have evolved from the S-RNases and is an example of a 'relic S-RNase'. A number of features distinguish the N. sylvestris RNase from the S-RNases, and the role these may have played in the presumed loss of the self-incompatibility response during the evolution of this species are discussed.

Identification and characterization of the Erwinia amylovora rpoS gene: RpoS is not involved in induction of fireblight disease symptoms

The Erwinia amylovora rpoS gene, encoding the alternative sigma factor RpoS, has been cloned and characterized. Though highly sensitive to a number of environmental stresses, an E. amylovora rpoS mutant was not compromised in its ability to grow or cause disease symptoms within apple seedlings or in an overwintering model.

Do magnitude estimation and lexical decision tap similar processes?

Young adults (n = 54 for Exp. 1, n = 50 for Exp. 2) and elderly adults (the same n = 40 in each experiment) participated in studies that required nonspeeded magnitude estimation scaling in response to words that varied in frequency and number of meanings. Across both experiments and across both groups, subject and item analyses indicated significant word frequency effects (low-frequency words were judged more difficult to process than high-frequency words) and significant word meaning effects (unambiguous words were judged to be more difficult to process than ambiguous words). Mean magnitude estimate values were significantly and positively correlated with mean lexical-decision task values obtained from the same subjects on the same stimuli based on data from a previous experiment. Results suggest that processes required for magnitude estimation are similar to those measured with the lexical decision task in word-recognition studies involving young and elderly adults.

Morphology and ultrastructure of sense organs on the ovipositor of Trybliographa rapae, a parasitoid of the cabbage root fly

The ovipositor of the parasitoid wasp Trybliographa rapae was examined by scanning and transmission electron microscopy. Characteristic peg-like sensilla with a cuticular ring at the base are found at the tip of the ventral valves, where they occur in a characteristic arrangement of triplets. The unusual basal structure probably protects the sensilla against damage during movement through the substrate and piercing of the host cuticle. These sensilla are each innervated by six dendrites, some of which have lamellated tips, generally considered to be characteristic of thermosensitivity. It is suggested that the remaining dendrites are gustatory, and as such probably respond to factors present in host haemolymph. A second type of peg-like sensillum is found on both the dorsal and the ventral valves. These are set in deep pits so that only the tip of the peg protrudes above the surface of the cuticle. These occur along the length of the ovipositor shaft and ultrastructural studies reveal the pegs to be innervated by a single mechanosensitive dendrite, probably monitoring the movement of the ovipositor through the substrate.

Computer-assisted three-dimensional reconstruction of head and neck tumors

OBJECTIVE

Because head and neck tumors reside in a complex area, having a three-dimensional (3-D) model of the patient's unique anatomical features may assist in the delineation of pathology. The authors describe a new computer technique of 3-D anatomical reconstruction from two-dimensional computed tomography (CT) and magnetic resonance (MR) data and discuss how it represents a step forward in the continuing evolution of 3-D imaging.

STUDY DESIGN

The authors selected three patients with solitary head and neck tumors and reconstructed their anatomy in a 3-D format for study. The tumors represented locations in the nose and central skull base (patient 1), temporal bone (patient 2), and neck (patient 3).

MATERIALS AND METHODS

MR and CT images from the individual patients were electronically transferred to workstations in the Surgical Planning Laboratory of the authors' institution. Registration (or fusion) was carried out between the MR and CT images. The desired anatomic components underwent segmentation (identification and isolation). Assembly of the segmented images was performed and the resulting structures were integrated to produce a 3-D model.

RESULTS

3-D models of the following were constructed and displayed in an interactive format on high-capacity computer workstations: 1) a skull base sarcoma with extension into the nasopharynx and nose; 2) an acoustic neuroma with internal auditory canal involvement; and 3) a metastatic recurrence of a tongue base squamous cell carcinoma in the posterior triangle of the right side of the neck with extension to the skull base.

CONCLUSION

The authors' Surgical Planning Laboratory has developed a 3-D reconstruction technique that has several new features. The models provided a very good 3-D interactive representation of the tumors and patient anatomy. The need now exists to develop this method of 3-D reconstruction of head and neck tumors for potential applications in treatment, research, and medical education.

Sentinel events: policy & preparation

Accreditation by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) is a sign of quality. Now JCAHO is increasing the stringency of its requirements by addressing sentinel events. Organizations--both home care providers and facilities--need to understand what a sentinel event is and how it affects accreditation status. Policies established to address these events will help home care providers maintain and/or improve the quality of the care they provide.

Primary pneumococcal peritonitis complicated by exudative pleural effusion in an adolescent girl

A healthy, young adolescent girl developed primary pneumococcal peritonitis, an infection rarely reported in this age group in North America. Her course was further complicated by exudative pleural effusion and pneumonia despite receiving 10 days of clindamycin therapy. Laparascopy proved useful in making the initial diagnosis, but may have contributed to the pathogenesis of the pulmonary process. Case presentation, management, and etiology are discussed.

Cognitive decline in Down syndrome: a validity/reliability study of the test for severe impairment

The utility of the Test for Severe Impairment was studied with 60 older persons who had Down syndrome. Construct validity, test-retest reliability, and interrater reliability were established for the full study group and for subgroups based on degree of mental retardation and dementia status. There was no difference in scores by gender. There were some interesting findings for the group with moderate mental retardation and dementia and the group with severe mental retardation without dementia that may signal specific applications and limitations of the test for use with individuals who have Down syndrome. The internal consistency of the instrument was satisfactory. Results suggest that this test is a useful performance-based task for persons with Down syndrome.

The CHO XRCC1 mutant, EM9, deficient in DNA ligase III activity, exhibits hypersensitivity to camptothecin independent of DNA replication

We have analyzed the X-ray-sensitive CHO mutant cell line EM9 for sensitivity to the topoisomerase I inhibitor comptothecin. These cells exhibit defective repair of single strand DNA breaks. Recently, EM9 were complemented the DNA ligase III interactive protein, XRCC1. Defective XRCC1 apparently accounts for the low DNA ligase III activity that may explain the single-strand break repair deficiency of EM9 cells. Here, we demonstrate cytotoxic hypersensitivity of EM9 cells following a brief camptothecin treatment. Both the S-phase and non-S-phase populations of EM9 exhibited camptothecin sensitivity relative to the parent cell line AA8. In AA8 cells, only the 55% of the population corresponding to the S-phase subpopulation were sensitive to camptothecin, while the remainder of the population were totally resistant to doses as high as 10 microM. The role of DNA replication in the camptothecin sensitivity was studied using the DNA polymerase inhibitor aphidicolin in co-treatment with camptothecin. Aphidicolin treatment fully protected AA8 cells from camptothecin cytotoxicity. In EM9 cells, aphidicolin protected the S-phase fraction to some degree but all the cells remained sensitive to camptothecin cytotoxicity. These results suggest that EM9 cells are sensitized to camptothecin by a mechanism that is independent of DNA replication and may be a consequence of the XRCC1 mutation or the associated deficiency in DNA ligase III activity. Mechanistic models for the replication-independent cytotoxicity of camptothecin in EM9 cells are discussed.

Highly restricted fertility: very small families in the British fertility decline

From the earliest stages of the British fertility decline, falling mean family size was accompanied by marked rises in the proportion of married women who remained childless or who bore only a single child. This paper summarises those changes, their impact on average family size, and the implications for estimates of the proportions of couples who attempted to space their children in the early years of marriage. The explanatory power of some commonly cited interpretations of the general decline in marital fertility is then considered in the context of this growth in number of families of highly restricted fertility. The paper highlights a need for more emphasis on descriptive and analytical approaches that are sensitive to distributions within populations. Also emphasized is the importance of developing interpretations that allow for the possibility that different factors may operate on different sub-sets of families at different points in time.

Endocrine function and emergency contraception: physiology and society

Relating emergency contraception, commonly referred to as "the morning-after pill," to the menstrual cycle can be used both to teach endocrine function and to show how physiology relates to the world outside the undergraduate classroom. The menstrual cycle is an excellent topic for teaching many features of the physiology of the human endocrine system. Relating emergency contraception to the menstrual cycle makes this topic relevant to both male and female students, provides opportunities for discussions that require the students' understanding of endocrine functions, and illustrates how physiology is connected to social economic, and political issues. The overview of emergency contraception and literature survey provided here are meant to be adapted for use in a variety of teaching contexts. The depth of coverage and the extent of consideration of issues beyond physiology would depend on many factors including the level fo the course and the size of enrollment.