The Interdisciplinary Generalist Curriculum Project at the University of Vermont College of Medicine: The Vermont Generalist Curriculum (VGC) Experience

The University of Vermont College of Medicine received its Vermont Generalist Curriculum (VGC) subcontract as one of the second-cycle Interdisciplinary Generalist Curriculum (IGC) Project schools from 1995 to 1998. The Vermont program was jointly codirected by the chairs of family practice and pediatrics and the program director for internal medicine on a rotating basis and was overseen by a multidisciplinary steering committee that included generalists, basic scientists, specialists, and students. This committee provided guidance and support in recruitment of preceptors, continuous assessment and improvement of the courses, development of a clinical correlation manual for students in clinical offices, and cooperation around a jointly sponsored annual primary care meeting that included a joint scientific program, a research forum, and a faculty development workshop. The VGC has provided a pilot for many innovative curricular changes that have served as models for the school-wide curriculum redesign process currently under way at VERMONT: While the funding for this project ended in 1998, the changes, innovations, and collaboration born out of the project are valuable enough for the dean's office to maintain the VGC's funding and its steering committee for the future.

Post hoc power analysis: an idea whose time has passed?

Using a hypothetical scenario typifying the experience that authors have when submitting manuscripts that report results of negative clinical trials, the pitfalls of a post hoc analysis are illustrated. We used the same scenario to explain how confidence intervals are used in interpreting results of clinical trials. We showed that confidence intervals better inform readers about the possibility of an inadequate sample size than do post hoc power calculations.

Mersilene mesh sling as an alternative to autogenous fascia lata in the management of ptosis

PURPOSE

To evaluate the use of Mersilene mesh as a brow suspensory material and to compare it clinically against autogenous fascia lata.

METHODS

A prospective study was carried out in which 80 eyes of 56 patients with ptosis and absent, poor or abnormal levator function were operated on. The patients were divided into two groups. In 46 eyes of 32 patients Mersilene mesh was used and in 34 eyes of 24 patients autogenous fascia lata was used. The results were recorded and analysed.

RESULTS

The age range for the Mersilene group was larger than for the fascia lata group and female patients preferred Mersilene over fascia lata. The improvement in lid height was significant in all cases in both groups. The complication rates were similar in the two groups and the mesh was well tolerated by the patients. No cases of infection, sling exposure or extrusion occurred with the use of Mersilene. Lid lag and lagophthalmos occurred as a complication of the procedure itself and not the type of the sling material. The mean follow-up period was 33.8 months for both groups.

CONCLUSION

We believe that Mersilene mesh is an effective alternative to autogenous fascia lata when the use of fascia lata is felt inappropriate.

Everyday life and legal values: a concept paper

This "concept paper" emerged from a Law and Human Behavior (LHB) Workshop, that was called by the journal's Editor, Richard Wiener, and held at St. Louis University on March 19-21, 1999. This workshop, which brought together 22 scholars and researchers in legal psychology, was part of James Ogloff's Presidential Initiative Project for the American Psychology/Law Society, and was supported by St. Louis University and an NSF grant. Prior to our arrival, each participant answered queries from the Editor about LHB and the field of psychology and law, and each was asked to offer five topics that were underrepresented in the journal or that we would like to see addressed in future issues. At the workshop, we were assigned to small groups, and the authors of this paper constituted one such group. The "charge" for all groups was to "develop plans for encouraging submissions in areas of psycholegal scholarship that continue to be infrequent topics of investigation," and then to develop a concept paper. The direction our group took is captured by our title, "Everyday Life and Legal Values," and within this paper we explicate the topic, identify a number of underrepresented research areas, suggest some research paradigms for investigating them, and present this within a "perspectival directions" frame that ties established lines of research to the newer ones we propose.

Mild head injury, anticoagulants, and risk of intracranial injury

We studied intracranial damage in patients with mild head injuries who were taking warfarin. Of the 215,785 individuals who visited the Mount Auburn and Beth Israel accident and emergency departments during our study, we identified records for 144 patients by anticoagulation status and computed tomography (CT) imaging. We retrospectively reviewed these patients and ten (7%, 95% CI 3-11) with clinically important injuries on cranial CT. Our findings suggest that patients with head injuries who receive anticoagulants have a similar or greater risk of intracranlal injury to those falling into a previously defined moderate-risk category, invalidating a previous conclusion that CT scanning is unnecessary in such patients.

Previous exposure to Chlamydia pneumoniae, Helicobacter pylori and other infections in Canadian patients with ischemic heart disease

OBJECTIVE

Previous exposures to Chlamydia pneumoniae (CP), Helicobacter pylori (HP) or cytomegalovirus (CMV) have been associated with atherosclerotic heart disease. These associations were studied in Canadian patients, and the exposure to five infections measured.

DESIGN

Case-control study.

SETTING

In the coronary care units (Hamilton General site, Henderson General site, McMaster University Medical Centre site of the Hamilton Health Sciences Corporation and St Joseph's Hospital) and from the regional angiography suite (Hamilton General site), Hamilton, Ontario.

PATIENTS AND METHODS

One hundred seven consecutive patients presenting with myocardial infarction or unstable angina (coronary care unit patients), or with previous angina or myocardial infarction (angiography suite patients), were compared with 107 family practice or outpatient clinic control subjects.

INTERVENTIONS

Cardiovascular risk factors were measured, as was serology for CP, HP, CMV, adenovirus and hepatitis A virus. Statistical analysis was by logistic regression, adjusted for age and sex.

RESULTS

Exposure to CP was more frequent in patients than in control subjects (85.4% versus 70.3%, adjusted odds ratio [OR] 2.3, 95% CI 1.1 to 5.1, P=0.03). Dividing CP immunoglobulin G absorbance into quarters, with the lowest quarter as the reference group, the adjusted ORs were 2.8, 3.0 and 4.3, respectively, for the second, third and fourth quarters (P=0.001 for trend). The seroprevalences of HP (61.7%), CMV (64.0%), adenovirus (75.6%) and hepatitis A virus (59.2%) were high, with no association with disease.

CONCLUSIONS

An association was found between heart disease and previous exposure to CP, with a stepwise increase in ORs at higher antibody levels, whereas no association was found with HP, CMV or other infections. A prospective validation of this association is needed.

Absent hematuria and expensive computerized tomography: case characteristics of emergency urolithiasis

PURPOSE

We validated the descriptive characteristics of emergency cases presenting with urolithiasis, determined the incidence of normal urinalysis in such cases and compared the expense of diagnostic computerized tomography (CT) and excretory urography (IVP).

MATERIALS AND METHODS

We retrospectively reviewed the charts of all consecutive patient visits to a community emergency department for 48 months. Explicit protocols for case selection, data abstraction and monitoring were used to maximize accuracy. Entry criteria were urolithiasis diagnosed by IVP, CT or stone passage, and urinalysis. Data analysis included descriptive statistics and the calculation of confidence intervals.

RESULTS

From 159,083 emergency visits during this period 397 met study entry criteria. Absent hematuria was noted in 9% (95% confidence interval 7% to 12%) of patients with proved urolithiasis. There was no correlation of the degree of obstruction with absent hematuria. Most patients presenting with painful urolithiasis were male (73%), in the fifth decade of life (mean age 47 years), had stones in the mid ureter (32%) or at the ureterovesicular junction (44%) and received opiates for pain control (91%). Of the patients 48% presented between 5 p.m. and 7 a.m. when the radiology department was available only for emergency imaging. The diagnosis was made by CT in half of the patients, who were charged $1,409. The maximal insurance reimbursement was $673. The diagnosis was made by IVP in half of the patients, who were charged $445. The maximal insurance reimbursement was $141.

CONCLUSIONS

Hematuria is not universally present in patients with painful urolithiasis and does not correspond to the degree of obstruction. Despite previous reports to the contrary, CT is significantly more expensive for patients than IVP.

The management of hypertension in Canada: a review of current guidelines, their shortcomings and implications for the future

Clinicians are exposed to numerous hypertension guidelines. However, their enthusiasm for these guidelines, and the impact of the guidelines, appears modest at best. Barriers to the successful implementation of a guideline can be identified at the level of the clinician, the patient or the practice setting; however, the shortcomings of the guidelines themselves have received little attention. In this paper, we review the hypertension guidelines that are most commonly encountered by Canadian clinicians: the "1999 Canadian Recommendations for the Management of Hypertension," "The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure" in the United States and the "1999 World Health Organization-International Society of Hypertension Guidelines for the Management of Hypertension." The key points of these guidelines are compared and the shortcomings that may impede their ability to influence practice are discussed. The main implications for future guideline developers are outlined.

Brinker is a sequence-specific transcriptional repressor in the Drosophila embryo

A Dpp activity gradient specifies multiple thresholds of gene expression in the dorsal ectoderm of the early embryo. Some of these thresholds depend on a putative repressor, Brinker, which is expressed in the neurogenic ectoderm in response to the maternal Dorsal gradient and Dpp signaling. Here we show that Brinker is a sequence-specific transcriptional repressor. It binds the consensus sequence, TGGCGc/tc/t, and interacts with the Groucho corepressor through a conserved sequence motif, FKPY. An optimal Brinker binding site is contained within an 800-bp enhancer from the tolloid gene, which has been identified as a genetic target of the Brinker repressor. A tolloid-lacZ transgene containing point mutations in this site exhibits an expanded pattern of expression, suggesting that Brinker directly represses tolloid transcription. We discuss other examples of transcriptional repressors constraining the activities of signaling pathways.

Topical L-ascorbic acid: percutaneous absorption studies

BACKGROUND

Reactive oxygen species generated by ultraviolet light result in photocarcinogenic and photoaging changes in the skin. Antioxidants protect skin from these insults.

OBJECTIVE

This study defines formulation characteristics for delivering L-ascorbic acid into the skin to supplement the skin's natural antioxidant reservoir.

METHODS

L-ascorbic acid or its derivatives were applied to pig skin. Skin levels of L-ascorbic acid were measured to determine percutaneous delivery.

RESULTS

L-ascorbic acid must be formulated at pH levels less than 3.5 to enter the skin. Maximal concentration for optimal percutaneous absorption was 20%. Tissue levels were saturated after three daily applications; the half-life of tissue disappearance was about 4 days. Derivatives of ascorbic acid including magnesium ascorbyl phosphate, ascorbyl-6-palmitate, and dehydroascorbic acid did not increase skin levels of L-ascorbic acid.

CONCLUSIONS

Delivery of topical L-ascorbic acid into the skin is critically dependent on formulation characteristics.

Clinical practice guidelines for the care and treatment of breast cancer: 11. Lymphedema

OBJECTIVE

To provide information and recommendations for women and their physicians when making decisions about the management of lymphedema related to breast cancer.

OPTIONS

Compression garments, pneumatic compression pumps, massage and physical therapies, other physical therapy modalities, pharmaceutical treatments.

OUTCOMES

Symptom control, quality of life, cosmetic results.

EVIDENCE

Systematic review of English-language literature retrieved primarily from MEDLINE (1966 to April 2000) and CANCERLIT (1985 to April 2000). Nonsystematic review of breast cancer literature published to October 2000.

RECOMMENDATIONS

Pre- and postoperative measurements of both arms are useful in the assessment and diagnosis of lymphedema. Circumferential measurements should be taken at 4 points: the metacarpal-phalangeal joints, the wrists, 10 cm distal to the lateral epicondyles and 15 cm proximal to the lateral epicondyles. Clinicians should elicit symptoms of heaviness, tightness or swelling in the affected arm. A difference of more than 2.0 cm at any of the 4 measurement points may warrant treatment of the lymphedema, provided that tumour involvement of the axilla or brachial plexus, infection and axillary vein thrombosis have been ruled out. Practitioners may want to encourage long-term and consistent use of compression garments by women with lymphedema. One randomized trial has demonstrated a trend in favour of pneumatic compression pumps compared with no treatment. Further randomized trials are required to determine whether pneumatic compression provides additional benefit over compression garments alone. Complex physical therapy, also called complex decongestive physiotherapy, requires further evaluation in randomized trials. In one randomized trial no difference in outcomes was detected between compression garments plus manual lymph drainage versus compression garments alone. Clinical experience supports encouraging patients to consider some practical advice regarding skin care, exercise and body weight. [A patient version of these guidelines appears in Appendix 2.]

VALIDATION

An initial draft of this document was developed by a task force sponsored by the BC Cancer Agency. It was updated and revised substantially by a writing committee and then submitted for further review, revision and approval by the Steering Committee for Clinical Practice Guidelines for the Care and Treatment of Breast Cancer.

SPONSOR

The steering committee was convened by Health Canada. COMPLETION DATE: October 2000.

The place for prescribing guidelines and the means of their dissemination

Practice guidelines are of potential benefit when a physician recognizes that they do not have all the facts required for providing appropriate health care. However, when guidelines for prescribing are known to the prescriber, and the physician chooses to modify or ignore them, their behaviour is being driven by personal and professional value systems that are in conflict with their knowledge base. Thus, providing practice guidelines to these physicians will not reduce suboptimal prescribing practices. In these circumstances, a number of studies suggest that addressing the social and situational involvement of physicians within the guidelines may enhance the promulgation and implementation of guidelines, and lead to more optimal prescribing choices for physicians.

Is it inherently prejudicial to try a juvenile as an adult?

Given only information that a youth who could have been tried as either an adult or as a juvenile was being tried as an adult for murder, 218 undergraduate mock jurors were able to form consistent impressions of the defendant. A very high percent of our mock jurors included a criminal or juvenile justice history as part of that impression. A very large majority of the mock jurors also said that knowledge of that criminal history would be relevant to their vote of guilty. Almost all mock jurors said they would be influenced toward voting guilty by knowledge of a previous criminal history. Few of the other components of the impression were so closely correlated with a judgment of relevance, or with a judgment that they would be influenced toward voting guilty by the knowledge of that component of the stereotype. The effect is relatively specific to knowledge of a previous criminal history. The study has limited ecological validity. Nonetheless, we raise questions about whether the fact that a youth is put on trial as an adult is inherently prejudicial, and violates the Sixth Amendment right to an impartial jury.

The regulation of forkhead/HNF-3beta expression in the Ciona embryo

The Ciona forkhead/HNF-3beta gene (Ci-fkh) is expressed in the primary axial tissues of the developing tadpole, including the notochord, endoderm, and rudimentary floor plate of the CNS. In an effort to determine the basis for this complex pattern of expression we have conducted a detailed analysis of the Ci-fkh 5'-regulatory region. Different 5' sequences were attached to a lacZ reporter gene and analyzed in electroporated Ciona embryos. A short regulatory sequence (AS) located approximately 1.7 kb upstream of the transcribed region is shown to be essential for expression in all three axial tissues. The proximal 20 bp of the AS contains overlapping Snail repressor elements and a T-box motif. Deleting these sequences causes the loss of reporter gene expression in the endoderm, as well as expanded expression in the neural tube. These results suggest that a T-box gene such as Ci-VegTR activates Ci-fkh expression in the endoderm, while the Ci-Sna repressor excludes expression from the lateral ependymal cells and restricts the Ci-fkh pattern to the rudimentary floor plate in ventral regions of the neural tube. We also present evidence for Ci-fkh positive autofeedback, whereby the Ci-Fkh protein binds to critical activator sites within the Ci-fkh 5'-regulatory region and helps maintain high levels of expression. We discuss these results with respect to forkhead/HNF-3beta regulation in vertebrates.

Predicting hand preference with performance on motor tasks

Handedness may be defined as preference or hand-differences in task performance. The strength and significance of the relationship between hand preference and hand performance asymmetries have been contested. To evaluate this relationship, we administered the Edinburgh Handedness Inventory and measured asymmetries in finger tapping, Purdue Pegboard, and grip strength in 30 subjects who prefer their right hand and 30 subjects who prefer their left hand. Hand asymmetries in finger tapping, Purdue Pegboard, and grip strength each predicted hand preference scores. However, a multiple regression equation best predicted hand preference by using performance of each task. Hand asymmetries in finger tapping correlated strongly with asymmetries in Purdue Pegboard performance, but neither of these asymmetries correlated strongly with asymmetries in grip strength. These findings indicate that hand preference and asymmetries in motor proficiency are strongly related, but suggest that preference and proficiency for different aspects of motor performance may be independently lateralized.

Conservation of the sequence and temporal expression of let-7 heterochronic regulatory RNA

Two small RNAs regulate the timing of Caenorhabditis elegans development. Transition from the first to the second larval stage fates requires the 22-nucleotide lin-4 RNA, and transition from late larval to adult cell fates requires the 21-nucleotide let-7 RNA. The lin-4 and let-7 RNA genes are not homologous to each other, but are each complementary to sequences in the 3' untranslated regions of a set of protein-coding target genes that are normally negatively regulated by the RNAs. Here we have detected let-7 RNAs of approximately 21 nucleotides in samples from a wide range of animal species, including vertebrate, ascidian, hemichordate, mollusc, annelid and arthropod, but not in RNAs from several cnidarian and poriferan species, Saccharomyces cerevisiae, Escherichia coli or Arabidopsis. We did not detect lin-4 RNA in these species. We found that let-7 temporal regulation is also conserved: let-7 RNA expression is first detected at late larval stages in C. elegans and Drosophila, at 48 hours after fertilization in zebrafish, and in adult stages of annelids and molluscs. The let-7 regulatory RNA may control late temporal transitions during development across animal phylogeny.

Treatment of venous thromboembolism in cancer patients

The occurrence of venous thromboembolism complicates the management of the patient with malignant disease because of the need for anticoagulant therapy. Cancer patients have an ongoing thrombotic stimulus due to the underlying cancer and its associated treatments, but are also considered to be at increased risk for anticoagulant-related bleeding. In recent years, the results of clinical trials have demonstrated the safety and efficacy of bodyweight-adjusted subcutaneous low-molecular-weight heparin administered at home for patients with acute deep vein thrombosis. This approach is particularly attractive in patients with cancer, in whom quality of life is an important consideration. There are no trials to date which specifically address the question of the duration of oral anticoagulant therapy in cancer patients. However, data can be extrapolated from trials evaluating the duration of oral anticoagulant therapy in other high-risk patients. Hence, cancer patients should continue oral anticoagulant therapy for as long the cancer remains active (usually at least 6 months). There remain a number of unanswered questions regarding the clinical management of thromboembolism in the cancer patient.

Vancomycin pharmacokinetics and Bayesian estimation in pediatric patients

The vancomycin pharmacokinetic profile was characterized in six pediatric patients and the potential of nonlinear mixed effects modeling and Bayesian forecasting for vancomycin monitoring was explored using NONMEM V (1.1). Based on steady state serial vancomycin concentrations, the estimates of mean t1/2, Vd, and Cl derived by the Sawchuk and Zaske method (1) were 3.52 hours, 0.57 L/kg, and 0.12 L/h per kg, respectively. NONMEM analysis demonstrated that a weight-adjusted two-compartment model described individual patients' data better than a comparable one-compartment model. The two-compartment estimates of mean t1/2alpha, t1/2beta, Vss, and Cl were 0.80 hour, 5.63 hours, 0.63 L/kg, and 0.11 L/h per kg, respectively. The relatively long mean t1/2alpha suggests that peak vancomycin concentrations measured earlier than 4 hours postdose do not reflect postdistributional serum concentrations. NONMEM population modeling revealed that a weight-adjusted two-compartment model provided a better fit than a comparable one-compartment model. The resulting population parameters and variances were fixed in NONMEM to obtain Bayesian predictions of individual vancomycin serum concentrations. Bayesian estimation with either a single midinterval or trough sample has the potential to provide accurate and precise predictions of vancomycin concentrations. This should be evaluated using a vancomycin population pharmacokinetic model based on a larger sample of pediatric patients.

Mental health professionals' experiences reporting suspected child abuse and maltreatment

OBJECTIVE

The purpose of this study was to provide systematic data on the experiences of mental health professionals (e.g., psychiatrists, psychologists, and social workers) who reported cases of suspected child abuse and maltreatment concerning their clients.

METHOD

Mail surveys were completed by 258 mental health professionals known to have reported a case of suspected child abuse and maltreatment to the New York State Central Register (NYSCR) in 1993. Subjects were asked to complete a survey describing their experience with making reports, referring to a specific case they reported.

RESULTS

About 40% did not inform the client about the limits of confidentiality until reportable material came up. Most clinicians reported that informing clients about the limits of confidentiality did not deter them from entering treatment. Many clinicians learned about abuse/maltreatment after approximately 3 months into therapy. Even very experienced clinicians usually consulted with others before making the report. Clinicians most typically informed the client about the report directly and before it was made, but did not call the NYSCR in the presence of the client. Following the report, most clinicians performed additional activities such as calling clients and scheduling additional sessions. When clients evidenced resistance to continuing therapy, it usually dissipated after a brief period of time. In over 72% of the cases, making the report did not disrupt the relationship and in many instances it was helpful in the therapeutic process; about 27% were continuously resistant or terminated therapy shortly after the report was made.

CONCLUSIONS

Implications for practice, training, program development, and research are discussed.

Dehydroascorbic acid transport by GLUT4 in Xenopus oocytes and isolated rat adipocytes

Dehydroascorbic acid (DHA), the first stable oxidation product of vitamin C, was transported by GLUT1 and GLUT3 in Xenopus laevis oocytes with transport rates similar to that of 2-deoxyglucose (2-DG), but due to inherent difficulties with GLUT4 expression in oocytes it was uncertain whether GLUT4 transported DHA (Rumsey, S. C. , Kwon, O., Xu, G. W., Burant, C. F., Simpson, I., and Levine, M. (1997) J. Biol. Chem. 272, 18982-18989). We therefore studied DHA and 2-DG transport in rat adipocytes, which express GLUT4. Without insulin, rat adipocytes transported 2-DG 2-3-fold faster than DHA. Preincubation with insulin (0.67 micrometer) increased transport of each substrate similarly: 7-10-fold for 2-DG and 6-8-fold for DHA. Because intracellular reduction of DHA in adipocytes was complete before and after insulin stimulation, increased transport of DHA was not explained by increased internal reduction of DHA to ascorbate. To determine apparent transport kinetics of GLUT4 for DHA, GLUT4 expression in Xenopus oocytes was reexamined. Preincubation of oocytes for >4 h with insulin (1 micrometer) augmented GLUT4 transport of 2-DG and DHA by up to 5-fold. Transport of both substrates was inhibited by cytochalasin B and displayed saturable kinetics. GLUT4 had a higher apparent transport affinity (K(m) of 0.98 versus 5.2 mm) and lower maximal transport rate (V(max) of 66 versus 880 pmol/oocyte/10 min) for DHA compared with 2-DG. The lower transport rate for DHA could not be explained by binding differences at the outer membrane face, as shown by inhibition with ethylidene glucose, or by transporter trans-activation and therefore was probably due to substrate-specific differences in transporter/substrate translocation or release. These novel data indicate that the insulin-sensitive transporter GLUT4 transports DHA in both rat adipocytes and Xenopus oocytes. Alterations of this mechanism in diabetes could have clinical implications for ascorbate utilization.

Epirubicin in breast cancer: present and future

Epirubicin, a member of the anthracycline family of chemotherapeutic agents, has been widely used throughout the world both as adjuvant therapy in early breast cancer and in metastatic breast cancer. Clinical trials with epirubicin have examined the importance of a dose-response relationship, therapeutic dose, and optimum duration of chemotherapy. In addition, pharmacokinetic studies have provided data on ideal combinations with other agents. Epirubicin-containing regimens are considered to be superior to those containing cyclophosphamide, methotrexate, and fluorouracil (CMF) and are also used in patients with locally advanced stage IIIA/IIIB breast cancer. Combinations with other chemotherapeutic agents (eg, epirubicin plus a taxane, sequential or combined use of these agents) are being evaluated in ongoing clinical trials. Moreover, recent studies have suggested that biologic markers, such as tumor HER2/neu overexpression, predict responses to dose-intensive anthracycline chemotherapy, and combinations with nonchemotherapeutic regimens (eg, trastuzumab) may provide additional benefits, but such strategies require further evaluation.

A novel process for updating recommendations for managing hypertension: rationale and methods

BACKGROUND

There are numerous hypertension consensus recommendations intended for practising physicians. However, recommendations in their current format have limited impact on improving hypertension control.

MATERIALS AND METHODS

A group of national societies, headed by the Canadian Hypertension Society, the Heart and Stroke Foundation of Canada, the Canadian Coalition for High Blood Pressure Prevention and Control, and Health Canada has developed strategies to maintain annually updated recommendations for hypertension management and to provide greater opportunities for their implementation into clinical practice. The process is overseen by a steering committee. Subcommittees have been formed for each of a list of topics seen as important to the control of hypertension. The subcommittees, with the aid of a central librarian, conduct annual literature reviews in accordance with Cochrane Collaboration strategies. Modified existing and new recommendations are forwarded to a group with expertise in clinical epidemiology. Grades of evidence are assigned to each recommendation. Revised recommendations based on the above process will be presented annually at the conjoint Canadian Hypertension Society/Canadian Cardiovascular Congress meeting. Under the leadership of the Cardiovascular Disease Division of the Laboratory Centre for Disease Control, Health Canada, a committee has been charged with the implementation process.

CONCLUSIONS

The improvements of the current process over previous national hypertension recommendations are four-fold. First, the recommendations will be updated annually. Second, the methodology has been improved. Third, the grading system can be used in the evaluation of complex study designs. Finally, the implementation process is extended. The authors are optimistic that these changes will contribute to the improvement of hypertension control in the Canadian population.

Characterization of a maternal T-Box gene in Ciona intestinalis

A new T-box gene, CiVegTR, was isolated in the ascidian Ciona intestinalis. CiVegTR maternal RNAs become localized to the vegetal cytoplasm of fertilized eggs and are incorporated into muscle lineages derived from the B4.1 blastomere. The CiVegTR protein binds to specific sequences within a minimal, 262-bp enhancer that mediates Ci-snail expression in the tail muscles. Mutations in these binding sites abolish expression from an otherwise normal lacZ reporter gene in electroporated embryos. In addition to the previously identified AC-core E-box sequences, T-box recognition sequences are conserved in the promoter regions of many genes expressed in B4.1 lineages in both Ciona and the distantly related ascidian Halocynthia. These results suggest that CiVegTR encodes a component of the classical muscle determinant that was first identified in ascidians nearly 100 years ago.

An algorithm to aid in the investigation of thalassemia trait in multicultural populations

CONTEXT

The differentiation between iron deficiency and a thalassemia syndrome is an important consideration in the investigation of microcytic anemia.

OBJECTIVE

An established statistical method was used to demonstrate the importance of considering ethnic background in combination with mean cell volume (MCV) in the investigation of beta-thalassemia trait in a multicultural urban population.

DESIGN

Posttest probabilities for beta-thalassemia trait were calculated using likelihood ratios for various microcytic MCV ranges in conjunction with published pretest probabilities for beta-thalassemia trait based on ethnic background.

SETTING

Regional hemoglobinopathy laboratory, St Joseph's Hospital, Hamilton, Ontario, Canada.

PATIENTS

Patient data were derived from a previously published study. The original study cohort consisted of 789 patients aged 18 years or older who had an MCV less than 80 fL and were referred for routine complete blood count during a 6-month period.

MAIN OUTCOME MEASURES

Posttest probabilities.

RESULTS

Simplified tables for the determination of posttest probabilities for beta-thalassemia trait in individual patients based on ethnic background and MCV are provided. An algorithm to assist in determining when thalassemia investigations are indicated is presented.

CONCLUSIONS

A high index of suspicion based on ethnic background and low MCV can provide increased sensitivity and specificity for the detection of thalassemia trait in centers with multicultural populations similar to the study population.

Reevaluation of ascorbate in cancer treatment: emerging evidence, open minds and serendipity

Some clinicians and alternative therapy practitioners advocate megadose intravenous and oral ascorbate treatment of cancer. Randomized control studies using oral ascorbate showed no benefit. Recent data show that intravenous but not oral administration of ascorbate can produce millimolar plasma concentrations, which are toxic to many cancer cell lines. We propose that ascorbate treatment of cancer should be reexamined by rigorous scientific scrutiny in the light of new evidence.

Dpp signaling thresholds in the dorsal ectoderm of the Drosophila embryo

The dorsal ectoderm of the Drosophila embryo is subdivided into different cell types by an activity gradient of two TGF(β) signaling molecules, Decapentaplegic (Dpp) and Screw (Scw). Patterning responses to this gradient depend on a secreted inhibitor, Short gastrulation (Sog) and a newly identified transcriptional repressor, Brinker (Brk), which are expressed in neurogenic regions that abut the dorsal ectoderm. Here we examine the expression of a number of Dpp target genes in transgenic embryos that contain ectopic stripes of Dpp, Sog and Brk expression. These studies suggest that the Dpp/Scw activity gradient directly specifies at least three distinct thresholds of gene expression in the dorsal ectoderm of gastrulating embryos. Brk was found to repress two target genes, tailup and pannier, that exhibit different limits of expression within the dorsal ectoderm. These results suggest that the Sog inhibitor and Brk repressor work in concert to establish sharp dorsolateral limits of gene expression. We also present evidence that the activation of Dpp/Scw target genes depends on the Drosophila homolog of the CBP histone acetyltransferase.

The effects of radiation therapy on quality of life of women with breast carcinoma: results of a randomized trial. Ontario Clinical Oncology Group

BACKGROUND

The purpose of this study was to evaluate the effect of breast irradiation on quality of life, including cosmetic outcome, for patients enrolled in a clinical trial.

METHODS

Between 1984 and 1989, a randomized trial was conducted in Ontario, Canada, in which women with lymph node negative breast carcinoma who had undergone lumpectomy and axillary lymph node dissection were randomized to either breast irradiation or no further treatment. A modified version of the Breast Cancer Chemotherapy Questionnaire (BCQ) was administered to women at baseline, 1 month (4 weeks), and 2 months (8 weeks) after randomization. Irritation of the skin of the breast, breast pain, and appearance of the breast to the patient were also assessed every 3 months for the first 2 years of the study.

RESULTS

Of 837 patients, 416 were randomly allocated to radiation therapy and 421 to no further treatment. The mean change in quality of life from baseline to 2 months was -0.05 for the radiation group and +0.30 for the control group. The difference between groups was statistically significant (P = 0.0001). Longer term radiation therapy increased the proportion of patients who were troubled by irritation of the skin of the breast and breast pain. Radiation therapy did not increase the proportion of patients at 2 years who were troubled by the appearance of the treated breast; 4.8% in irradiated and nonirradiated patients (P = 0.62).

CONCLUSIONS

Breast irradiation therapy had an effect on quality of life during treatment. After treatment, irradiated patients reported increased breast symptoms compared with controls. However, no difference was detected between groups at 2 years in the rates of skin irritation, breast pain, and being upset by the appearance of the breast.

Intracellular accumulation of ascorbic acid is inhibited by flavonoids via blocking of dehydroascorbic acid and ascorbic acid uptakes in HL-60, U937 and Jurkat cells

In HL-60, U937 and Jurkat cells, the intracellular accumulation of ascorbic acid occurred via uptakes of both dehydroascorbic acid (an oxidized metabolite of ascorbic acid) and ascorbic acid (vitamin C). Dehydroascorbic acid and ascorbic acid were transported into cells by sodium-independent glucose transporters (GLUT 1 and GLUT 3) and sodium-dependent ascorbic acid transporters, respectively. Flavonoids inhibited the intracellular accumulation of ascorbic acid by blocking dehydroascorbic acid and ascorbic acid uptakes in the transformed cells. At flavonoid concentrations of 10-70 micromol/L, approximately 50% of dehydroascorbic acid uptake was inhibited in the cells. In Jurkat cells, two potent flavonoids (myricetin and quercetin) competitively inhibited dehydroascorbic acid uptake, and K(i) values were approximately 14 and 15 micromol/L, respectively. Because GLUT 1 and GLUT 3 transport dehydroascorbic acid, the inhibition of dehydroascorbic acid uptake by flavonoids was investigated by using Chinese hamster ovary cells overexpressing rat GLUT 1 or human GLUT 3. Myricetin at concentrations of 22 and 18 micromol/L, respectively, inhibited half of dehydroascorbic acid uptake in the cells overexpressing GLUT 1 and GLUT 3. Myricetin also inhibited ascorbic acid uptake; inhibition was noncompetitive with K(i) = 14 micromol/L in Jurkat cells. These data indicate that flavonoids inhibit both ascorbic acid and dehydroascorbic acid uptake but do so by different mechanisms. These data may contribute to new understanding of the biological effect of flavonoids on the intracellular accumulation of ascorbic acid in human cells.

A cross-cultural consumer-based decision aid for screening mammography

BACKGROUND

"Women should have mammograms" is the usual perspective of educational interventions about screening. The perspective that "women should be informed" about potential risks and benefits so they can make value- and evidence-integrated personal decisions has recently been advocated. However, this perspective has not previously been operationalized. We developed an evidence-based cross-cultural mammography decision aid (MDA), for European American and Mexican American women who are 50-70 years old, at average risk of breast cancer, of varying educational levels, and English- or Spanish-speaking.

METHODS

MDA development included: (1) content development by a multidisciplinary team and lay women and (2) testing for validity and reliability. Four parts include: (1) introduction; (2) information about logistics (cost, time, discomfort) and risks (sequelae of false-positive or negative results; (3) probability of developing breast cancer; and (4) benefit of mammography regarding breast cancer outcomes (e.g., death and recurrence). We assessed reliability (stability of decisions with the same information) after 1-2 weeks. We assessed validity (comprehension of information) quantitatively (probabilities were changed to see whether preferences changed predictably) and qualitatively (focus groups, standardized probes for comprehension). Subjects were a convenience sample of 49 European American (50-81 years old) and 54 Mexican American (49-89 years old) women from administrative staff at a medical school, the waiting room of an indigent primary care clinic, and a community center.

RESULTS

Reliability was 100%. In quantitative validity testing, 22 of 28 women (89%) changed preference as predicted with changed probabilities. Comprehension was confirmed qualitatively in all phases of testing with both Spanish and English versions.

CONCLUSION

The decision aid is valid and reliable in English and Spanish for southwestern Mexican American and European American women at average risk of breast cancer, including those of low educational levels.

Optimization of inspiratory work in periodic breathing in infants

In periodic breathing, there are repeated cycles of bursts of breaths separated by pauses several seconds long. We consider the mechanics of periodic breathing in human infants using calibrated traces of tidal volume and esophageal pressure recorded during the first few days after delivery. Each cycle of periodic breathing was analyzed in terms of the inspiratory time and beginning and end inspiratory volumes for each breath, the number of breaths in the cycle, and the total observed inspiratory work. A simple model was used to characterize the mechanics of the lung during inspiration, and the recordings were used to calculate the parameters of this model. These varied from breath to breath. A theoretical formula is derived for the sum of external work performed during inspiration for each burst. It is shown mathematically that there exists a local minimum in the calculated work as the values of the individual tidal volumes in this formula are allowed to vary, with the constraint that the sum of the ventilation during the cycle is as measured. The measured values of inspiratory timing, the starting volume and pressure, and the mechanical parameters for each inspiration are also used. We show that during each cycle of periodic breathing, the total of the observed external work is highly correlated with this theoretical minimum work. In addition, during the cycle, there is a pattern of overshoot and subsequent undershoot in the work with respect to the theoretical optimum, which suggests a control process operating during the cycle to minimize the work.

Characterization of the promoter of the human ribonucleotide reductase R2 gene

We describe here cloning and characterization of the promoter region of the human ribonucleotide reductase R2 gene. Primer extension and sequence data indicated that two different transcripts were produced via using two different promoter regions. Promoter activity of the 5' flanking region of the first transcript was approximately 100-fold higher than controls, and that of the second transcript was approximately 30-fold higher than controls. Particularly, the proximal region of the first transcript, -125 to +1 bp, was responsible for approximately a 50-fold increase in promoter activity, compared to controls. This region had three CCAAT sequences, each of which contributed similarly to promoter activity. When all three CCAAT sequences were mutated, promoter activity declined 80%. In addition, the promoter region -125 to +1 bp was responsible for cell-cycle-specific expression. These data provided essential information concerning regulatory mechanisms of cell-cycle-specific expression of human ribonucleotide reductase R2.

Risk of congenital malformations associated with treatment of asthma during early pregnancy

Studies assessing the risk of congenital malformations associated with the treatment of asthma during the first trimester of pregnancy are few, have limited power and support continuation of treatment.

The family group conference in the New Zealand children, young persons, and their families act of 1989 (CYP&F): review and evaluation

The family group conference is an innovation introduced into New Zealand law as a means of resolving child protection and youth justice cases. The law requires the conference to include the offender, the victim, the extended family, and other relevant parties. This article reviews New Zealand research and commentary, and publications reporting on experiences with the methods in other countries. The discussion emphasizes problems in adapting a method based on one culture to a different culture and social organization. The article also considers the law from the viewpoint of therapeutic jurisprudence. Although the research is sparse, the FGC has strong promise for resolving problems, enhancing the sense of community and participation, and empowering families.

Regulation of Ci-tropomyosin-like, a Brachyury target gene in the ascidian, Ciona intestinalis

Brachyury is a sequence-specific transcriptional activator that is essential for notochord differentiation in a variety of chordates. In vertebrates, Brachyury is expressed throughout the presumptive mesoderm, but becomes restricted to the notochord at later stages of development. In ascidians, such as Ciona intestinalis, Brachyury is expressed exclusively in the notochord and does not exhibit an early pan-mesodermal pattern. Subtractive hybridization screens were recently used to identify potential Ciona Brachyury (Ci-Bra) target genes (Takahashi, H., Hotta, K., Erives, A., Di Gregorio, A., Zeller, R. W., Levine, M. and Satoh, N. (1999). Genes Dev. 13, 1519–1523). Of the genes that were identified in this screen, one corresponds to a new member of the tropomyosin superfamily, Ciona tropomyosin (Ci-trop). Here we show that Ci-trop is specifically expressed in the developing notochord beginning at gastrulation, and expression persists in the notochord during tailbud and tadpole stages. A 3 kb region of the Ci-trop 5′-flanking sequence was characterized via electroporation of lacZ fusion genes into fertilized Ciona eggs. A minimal, 114 bp enhancer was identified that is sufficient to direct the expression of a heterologous promoter in the notochord. DNA binding assays indicate that this enhancer contains two sets of low-affinity Brachyury half-sites, which are bound in vitro by a GST/Ci-Bra fusion protein. Deletion of the distal sites inactivates the notochord-specific staining pattern mediated by an otherwise normal Ci-trop/lacZ transgene. These results suggest that Ci-trop is a direct target gene of Ci-Bra and that Brachyury plays an immediate role in the cellular morphogenesis of the notochord.

A novel cis-regulatory element, the PTS, mediates an anti-insulator activity in the Drosophila embryo

The Abd-B Hox gene contains an extended 3' cis-regulatory region that is subdivided into a series of separate lab domains. The lab-7 domain activates Abd-B in parasegment 12 (ps12), whereas lab-8 controls expression in ps13. iab-7 is flanked by two insulators, Fab-7 and Fab-8, which are thought to prevent regulatory factors, such as Polycomb silencers, from influencing neighboring iab domains. This organization poses a potential paradox, since insulator DNAs can work in a dominant fashion to block enhancer-promoter interactions over long distances. Here, we present evidence for a novel cis-regulatory sequence located within lab-7, the promoter targeting sequence (PTS), which permits distal enhancers to overcome the blocking effects of Fab-8 and the heterologous su(Hw) insulator. We propose that the PTS converts dominant, long-range insulators into local regulatory elements that separate neighboring lab domains.

Temporal expression patterns of 39 Brachyury-downstream genes associated with notochord formation in the Ciona intestinalis embryo

Expression of the Brachyury (Ci-Bra) gene of the ascidian Ciona intestinalis is initiated at the 64-cell stage. Gene expression is restricted to notochord precursor cells, and Ci-Bra plays a key role in notochord differentiation. In a previous study, nearly 50 cDNA clones for potential Ci-Bra-downstream genes that are expressed in notochord cells were isolated. The present determination, by whole-mount in situ hybridization, of the temporal expression patterns of 19 notochord-specific and 20 notochord-predominant genes demonstrated that the timings of initiation of the expression of various genes was not identical. The expression of several genes was initiated as early as the gastrula stage. However, the expression of most of the notochord-specific genes commenced at the neural plate stage. Partial nucleotide sequence data of these clones suggest that genes expressed earlier encode potential transcriptional factors and/or nuclear proteins, while those expressed later encode proteins implicated in cell adhesion, signal transduction, regulation of the cytoskeleton, and components of the extracellular matrix. These gene activities may be associated with changes in cell shape and adhesion during the intercalation and extension of the notochord cells.

Cloning and functional characterization of the human sodium-dependent vitamin C transporters hSVCT1 and hSVCT2

Two sodium-dependent vitamin C transporters, hSVCT1 and hSVCT2, were cloned from a human kidney cDNA library. hSVCT1 had a 1797 bp open reading frame encoding a 598 amino acid polypeptide. The 1953 bp open reading frame of hSVCT2 encoded a 650 amino acid polypeptide. Using a Xenopus laevis oocyte expression system, both transporters were functionally expressed. By Eadie-Hofstee transformation the apparent K(m) of hSVCT1 for ascorbate was 252.0 microM and of hSVCT2 for ascorbate was 21.3 microM. Both transporters were sodium-dependent and did not transport dehydroascorbic acid. Incubation of oocytes expressing either transporter with phorbol 12-myristate 13-acetate (PMA) inhibited ascorbate transport activity. Availability of the human transporter clones may facilitate new strategies for determining vitamin C intake.

Economic evaluation of outpatient treatment with low-molecular-weight heparin for proximal vein thrombosis

BACKGROUND

The safety and efficacy of taking low-molecular-weight heparin at home was previously demonstrated in a clinical trial in which patients with acute proximal deep vein thrombosis were randomized to receive either intravenous standard heparin in the hospital or subcutaneous low-molecular-weight heparin administered primarily at home. Treatment in the home has the potential to substantially reduce the cost to the health care system.

METHODS

To conduct an economic evaluation we prospectively collected data on resource use and health-related quality of life (Medical Outcomes Study Short-Form 36) on the 300 patients who formed the trial stratum presenting with proximal vein thrombosis as outpatients, of whom 151 received standard heparin and 149 received low-molecular-weight heparin. The primary viewpoint of the analysis was societal, and costs included health care costs, patient travel costs, and productivity costs as a result of time off work. Costs were assessed over a period of 3 months from randomization. Quality of life was assessed as the change in Short-Form 36 domain scores from baseline to day 7 for each treatment group. All costs are reported in 1997 Canadian dollars.

RESULTS

There were 11 recurrent thromboembolic events and 1 bleed in the 151 patients who received standard heparin; the corresponding data for the 149 patients receiving low-molecular-weight heparin were 10 and 4, respectively. The mean cost per patient who received standard heparin was Can $5323 compared with Can $2278 for low-molecular-weight heparin, a total societal cost savings per patient using low-molecular-weight heparin of Can $3045 (95% confidence interval, Can $2012-$4050). There was no difference in quality of life between the 2 groups except for the domain of social functioning, where a greater improvement from baseline to day 7 was observed for the low-molecular-weight heparin group vs the standard heparin group (P =.005).

CONCLUSIONS

For patients with acute proximal deep vein thrombosis, treatment at home with low-molecular-weight heparin is less costly than hospital-based treatment with standard heparin. The economic evidence in favor of outpatient treatment with low-molecular-weight heparin exhibits dominance; a situation of reduced cost is created with no compromise in clinical outcomes or patients' quality of life.

Recurrent venous thrombosis and heparin therapy: an evaluation of the importance of early activated partial thromboplastin times

BACKGROUND

The presence of an association between early subtherapeutic activated partial thromboplastin times (aPTTs) and recurrent venous thromboembolism (VTE) remains controversial.

OBJECTIVE

To determine the relation between early subtherapeutic aPTTs and recurrent VTE in patients who were treated with intravenous (i.v.) unfractionated heparin (UFH).

PATIENTS AND METHODS

We studied 961 patients with acute VTE who received i.v. UFH in 3 randomized trials that compared the use of i.v. UFH (loading dose: 5000 U i.v.; initial infusion, 1250-1280 U/h) with that of subcutaneous low-molecular-weight heparin. According to aPTT criteria, patients were classified as being in a subtherapeutic or a therapeutic state during the first 24 and 48 hours of treatment. All episodes of possible recurrent VTE were adjudicated by an independent committee that was unaware of the aPTTs.

RESULTS

At 24 hours, in 886 patients who were eligible for the analysis, the rate of recurrent VTE in the subtherapeutic group was 6.7% (11/163) compared with 5.3% (38/723) in the therapeutic group. The odds ratio for recurrence in patients in the subtherapeutic vs the therapeutic group at 24 hours was 1.30 (95% confidence interval: 0.64-2.63; P = .46). At 48 hours, in 917 patients who were eligible for the analysis, the rate of recurrent VTE in the subtherapeutic group was 7.8% (5/64) compared with 5.7% (49/853) in the therapeutic group. The odds ratio for recurrence in patients in the subtherapeutic vs the therapeutic group at 48 hours was 1.32 (95% confidence interval: 0.51-3.44; P = .56).

CONCLUSION

In patients with acute VTE who receive an i.v. bolus of 5000 U, followed by a starting dose of at least 1250 U/h of UFH, a subtherapeutic aPTT response during the first 48 hours of treatment is not associated with a large increase in the risk of recurrent VTE.

Specificity of ascorbate analogs for ascorbate transport. Synthesis and detection of [(125)I]6-deoxy-6-iodo-L-ascorbic acid and characterization of its ascorbate-specific transport properties

Cellular ascorbic acid accumulation occurs in vitro by two distinct mechanisms: transport of ascorbate itself or transport and subsequent intracellular reduction of its oxidized product, dehydroascorbic acid. It is unclear which mechanism predominates in vivo. An easily detectable compound resembling ascorbate but not dehydroascorbic acid could be a powerful tool to distinguish the two transport activities. To identify compounds, 21 ascorbate analogs were tested for inhibition of ascorbate or dehydroascorbic acid transport in human fibroblasts. The most effective analogs, competitive inhibitors of ascorbate transport with K(i) values of 3 microM, were 6-deoxy-6-bromo-, 6-deoxy-6-chloro-, and 6-deoxy-6-iodo-L-ascorbate. No analog inhibited dehydroascorbic acid transport. Using substitution chemistry, [(125)I]6-deoxy-6-iodo-L-ascorbate (1.4 x 10(4) mCi/mmol) was synthesized. HPLC detection methods were developed for radiolabeled and nonradiolabeled compounds, and transport kinetics of both compounds were characterized. Transport was sodium-dependent, inhibited by excess ascorbate, and similar to that of ascorbate. Transport of oxidized ascorbate and oxidized 6-deoxy-6-iodo-L-ascorbate was investigated using Xenopus laevis oocytes expressing glucose transporter isoform GLUT1 or GLUT3. Oxidation of ascorbate or its analog in media increased uptake of ascorbate in oocytes by 6-13-fold compared with control but not that of 6-deoxy-6-iodo-L-ascorbate. Therefore, 6-deoxy-6-iodo-L-ascorbate, although an effective inhibitor of ascorbate transport, either in its reduced or oxidized form was not a substrate for dehydroascorbic acid transport. Thus, radiolabeled and nonradiolabeled 6-deoxy-6-iodo-L-ascorbate provide a new means for discriminating dehydroascorbic acid and ascorbate transport in ascorbate recycling.