Development of a standardized, comprehensive "ideal drug detail"

OBJECTIVES

To develop a standardized, comprehensive ideal drug detail for use in face-to-face education about individual drugs.

METHODS

A random sample of 603 physicians and pharmacists was selected and stratified to include input from each of the following specialties: family practice, internal medicine, surgery, pediatrics, psychiatry, obstetrics/gynecology, geriatric medicine and clinical pharmacology. Thirty-one potential items were generated by the investigators from a preliminary survey of a local convenience sample of physicians and pharmacists. A modified Delphi consensus process was used in the large sample to determine which items should be included in the ideal drug detail. In each round of the Delphi process, respondents rated each item on a seven-point scale of importance and were then given feedback of the cumulative ratings for each item. Rounds were continued until consensus was obtained on all items.

RESULTS

The response rate to the first round was 55.3%; 85.5% of these respondents responded to the second round. Response rates varied between specialties from 44% to 70%. Attempts to contact nonresponders to measure potential nonrespondent bias were unsuccessful. Consensus was obtained on 19 items after the first round, and on the remaining 12 items after the second round. Four items were dropped because they were unimportant. There was variation in modal response between specialties on eight items.

CONCLUSIONS

Consensus was obtained among a sizable and interested sample of Canadian physicians and pharmacists on the items of information needed to prescribe a drug appropriately. Subsequent work will refine this list into a usable template to develop ideal drug details for specific drugs, to develop an assessment process to measure quality of information, and to assess the impact of this program on prescribing and patient outcomes.

Glucose regulation and brain aging

Blood glucose regulation is not only a complex phenomenon but glucose regulatory levels also vary significantly across individuals. Thus, whereas individuals compromised with moderately elevated blood glucose levels are diagnosed as having impaired glucose tolerance, excessive blood glucose levels render a Type II diabetes diagnosis. Type II diabetes prevalence rates in the adult population have been estimated to be between 6 and 10 percent. Although Type II diabetes has been typically associated with older people, the disease has become much more common among young adults and children. It has become increasingly evident that protracted glucose tolerance impairment usually precedes a type II diabetes diagnosis, although impaired glucose tolerance will not necessarily progress to a diabetic state. Furthermore, a number of studies have shown that impaired glucose tolerance or type II diabetes is associated with impaired cognitive function in older subjects. In addition, we recently found that cognitive deficits are also associated with moderately impaired glucose regulation in young healthy volunteers. These data, although in need of confirmation and extension, suggest that impaired glucose tolerance is associated with impaired cognition, independent of age. Moreover, since impaired glucose tolerance is more prevalent than diabetes across all ages, then our finding lead to the implication that impaired cognitive function may be more prevalent in the general population than previously estimated. Finally, the dysfunction of glucoregulatory mechanisms may be an important intervening factor when studying the evolution of cognitive function through the aging process.

Estrogen replacement therapy improves baroreflex regulation of vascular sympathetic outflow in postmenopausal women

BACKGROUND

Menopausal estrogen loss has been associated with increased cardiovascular disease in postmenopausal women. However, the link between estrogen and cardiovascular disease remains unclear. Some data suggest estrogen mediates its effect through changes in arterial pressure and its regulation. However, the data available in older women are equivocal regarding estrogen's ability to reduce resting arterial pressure or to improve its regulation.

METHODS AND RESULTS

We studied 11 healthy, postmenopausal women before and after 6 months of estrogen administration. Arterial pressure was measured by brachial auscultation and finger photoplethysmography. Vascular sympathetic nerve activity was measured in the peroneal nerve by microneurography, and the slope of the relations between changes in heart period, sympathetic activity, and arterial pressure caused by bolus infusions of nitroprusside and phenylephrine were used as an index of baroreflex gain. Estrogen therapy did not change systolic pressure (128+/-2 versus 123+/-2 mm Hg) or cardiac-vagal baroreflex gain (6.6+/-0.9 versus 6.7+/-0.7 ms/mm Hg). However, vascular sympathetic baroreflex gain was increased (-4.6+/-0.6 versus -7.4+/-1.0 arbitrary integrated units/mm Hg; P=0.02).

CONCLUSION

These findings suggest long-term estrogen replacement therapy has effects on cardiovascular regulation that may not be reflected in resting arterial pressures.

A force platform for large human displacements

This paper provides details of a force platform assembly suitable for measuring the magnitude, position and direction of ground reaction forces for manual handling tasks involving several footsteps in any horizontal direction. An approach to increase the natural frequency with the use of a vibration absorber is used; this frequency was found to be 41+/-2 Hz. The results show a maximum error of 22 N (2% of the full scale output) when a person performs repetitive movements from a squat position to a full extension and back to the squat position. Static tests show the maximal errors to be, vertically, 1.5% of the full scale output (1818+/-33 N), and horizontally, 4.9% of the full scale output (1177+/-6 N).

Mapping of the RNA recognition site of Escherichia coli ribosomal protein S7

Bacterial ribosomal protein S7 initiates the folding of the 3' major domain of 16S ribosomal RNA by binding to its lower half. The X-ray structure of protein S7 from thermophilic bacteria was recently solved and found to be a modular structure, consisting of an alpha-helical domain with a beta-ribbon extension. To gain further insights into its interaction with rRNA, we cloned the S7 gene from Escherichia coli K12 into a pET expression vector and introduced 4 deletions and 12 amino acid substitutions in the protein sequence. The binding of each mutant to the lower half of the 3' major domain of 16S rRNA was assessed by filtration on nitrocellulose membranes. Deletion of the N-terminal 17 residues or deletion of the B hairpins (residues 72-89) severely decreased S7 affinity for the rRNA. Truncation of the C-terminal portion (residues 138-178), which includes part of the terminal alpha-helix, significantly affected S7 binding, whereas a shorter truncation (residues 148-178) only marginally influenced its binding. Severe effects were also observed with several strategic point mutations located throughout the protein, including Q8A and F17G in the N-terminal region, and K35Q, G54S, K113Q, and M115G in loops connecting the alpha-helices. Our results are consistent with the occurrence of several sites of contact between S7 and the 16S rRNA, in line with its role in the folding of the 3' major domain.

Dynamic regulation of middle cerebral artery blood flow velocity in aging and hypertension

BACKGROUND AND PURPOSE

Although aging and hypertension may predispose hypertensive elderly subjects to cerebral hypoperfusion during orthostatic stress, their effects on the acute cerebral autoregulatory response to hypotension are not known.

METHODS

Continuous middle cerebral artery blood flow velocity (BFV) (transcranial Doppler ultrasound) and mean arterial pressure (MAP, Finapres) were measured in response to (1) acute hypotension during standing, (2) steady-state sitting and standing, and (3) hypercarbia during CO(2) rebreathing in 10 healthy young subjects (age 24+/-1 years), 10 healthy elderly subjects (age 72+/-3 years), and 10 previously treated hypertensive elderly (age 72+/-2 years) subjects. CO(2) reactivity was computed as the slope of cerebrovascular conductance (CVC=BFV/MAP) versus end-expiratory CO(2). Coherence, transfer magnitudes, and phases between low-frequency MAP and BFV signals were computed from their autospectra during 5 minutes of sitting and standing.

RESULTS

MAP fell to a similar extent in all groups by an average of 21 to 26 mm Hg (22% to 26%) within 30 seconds of standing. Mean BFV also fell in all subjects but significantly less in the older subjects (-4.7+/-0. 7 cm/s in hypertensives and -5.3+/-1.2 cm/s in normotensives, P=NS) compared with younger subjects (-10.1+/-1.1 cm/s, P<0.05). CO(2) reactivity was greater in the young subjects (0.19+/-0.01) compared with normotensive (0.14+/-0.01, P<0.05) and hypertensive elderly subjects (0.11+/-0.02, P<0.05) (P=NS between elderly groups). Fewer hypertensive subjects had coherence between MAP and BFV signals; for subjects with coherence, there were no significant group differences in phase or transfer magnitudes in either sitting or standing positions.

CONCLUSIONS

Despite reduced CO(2) reactivity, elderly normotensive and previously treated hypertensive subjects retain cerebral autoregulatory capacity in response to acute orthostatic hypotension.

Strategies of load tilts and shoulders positioning in asymmetrical lifting. A concomitant evaluation of the reference systems of axes

OBJECTIVES

To evaluate two handling factors on asymmetry of posture and efforts and to evaluate different reference systems of axes on the characterization of asymmetry.DESIGN. Ten novice workers performed three tasks evaluated for the effects of load tilting (tilts vs no tilts) and shoulders positioning (non-parallel vs parallel to the ground). Specific comparisons were made using three referential systems.BACKGROUND. Box handgrips/tilting and body posture are factors differentiating expert and novice workers which present a potential for reducing asymmetries. The literature also suggests that different conclusions may be reached about asymmetry with different systems of axes.METHODS. Net 3D moments at L5/S1 were obtained from two force platforms, four video cameras and inverse dynamic analyses using three reference systems of axes (trunk, pelvis, and joint).RESULTS. Tilting the load presented clear advantages of reducing the duration and trajectory of efforts, better positioning the load and reducing knee flexion, peak trunk extensors and mechanical work on the load. The maintenance of the shoulders parallel reduced asymmetries of posture and efforts but the results were affected by the type of reference system of axes chosen.CONCLUSIONS. Box tilting and shoulders positioning should be considered in the reduction of risk factors. More research is needed to define referential systems and characterize asymmetry. RelevanceBox tilting and shoulders positioning appear to be two fundamental elements to take into account in the formation programs based on prevention of risk factors. The importance of asymmetry among the risk factors emphasizes the need for better characterization of this risk.

Evolution of anthropoid jaw loading and kinematic patterns

Major transformations in the skull and masticatory system characterized the evolution of crown anthropoids. To offer further insight into the phylogenetic and arguably adaptive significance of specific primate mandibular loading and kinematic patterns, allometric analyses of metric parameters linked to masticatory function are performed within and between 47 strepsirhine and 45 recent anthropoid species. When possible, basal anthropoids are considered. These results are subsequently integrated with prior experimental and morphological work on primate skull form. As compared to strepsirhines, crown anthropoids have a vertically longer ascending ramus linked to a glenoid and condyle positioned relatively higher above the occlusal plane. Interestingly, anthropoids and strepsirhines do not exhibit different mean ratios of condylar to glenoid height, which suggests that both clades are similar in their ability to evenly distribute occlusal contacts and perhaps forces along the postcanine teeth. Thus, given the considerable suborder differences in the scaling of both glenoid and condylar height, we argue that much of this variation in jaw-joint height is linked to suborder differences in relative facial height due in turn to increased encephalization, basicranial flexion, and facial kyphosis in anthropoids. Due to a more elongate ascending ramus, anthropoids evince more vertically oriented masseters than like-sized strepsirhines. Having a relatively longer ramus and a more medially displaced lateral pterygoid plate, crown anthropoids exhibit medial pterygoids oriented similar to those of strepsirhines, but with a variably longer lever arm. As anthropoid masseters are less advantageously placed to effect transverse movements/forces, we argue that balancing-side deep-masseter activity underlying a wishboning loading regime serves to increase, or at least maintain, transverse levels of jaw movement and occlusal force at the end of the masticatory power stroke. Crown anthropoids are also more isognathic and isodontic than strepsirhines. A consideration of early anthropoids suggests that the crown anthropoid masticatory pattern, i.e., more vertical masseters due to a high condyle as well as greater isognathy and isodonty, occurred stepwise during stem anthropoid evolution. This appears to correspond to a more transverse, and perhaps progressively larger, power stroke across oligopithecids, parapithecids, and propliopithecids.

Rapid detection of group B streptococci in pregnant women at delivery

BACKGROUND

Group B streptococcal infections are an important cause of neonatal morbidity and mortality. A rapid method for the detection of this organism in pregnant women at the time of delivery is needed to allow early treatment of neonates.

METHODS

We studied the efficacy of two polymerase-chain-reaction (PCR) assays for routine screening of pregnant women for group B streptococci at the time of delivery. We obtained anal, vaginal, and combined vaginal and anal specimens from 112 pregnant women; in 57 women, specimens were obtained before and after the rupture of the amniotic membranes. The specimens were tested for group B streptococci by culture in a standard selective broth medium, with a conventional PCR assay, and with a new fluorogenic PCR assay.

RESULTS

Among the 112 women, the results of the culture of the combined vaginal and anal specimens were positive for group B streptococci in 33 women (29.5 percent). The two PCR assays detected group B streptococcal colonization in specimens from 32 of these 33 women: the one negative PCR result was in a sample obtained after the rupture of membranes. As compared with the culture results, the sensitivity of both PCR assays was 97.0 percent and the negative predictive value was 98.8 percent. Both the specificity and the positive predictive value of the two PCR assays were 100 percent. The length of time required to obtain results was 30 to 45 minutes for the new PCR assay, 100 minutes for the conventional PCR assay, and at least 36 hours for culture.

CONCLUSIONS

Colonization with group B streptococci can be identified rapidly and reliably by a PCR assay in pregnant women in labor both before and after the rupture of membranes.

Early human occupation of the Red Sea coast of Eritrea during the last interglacial

The geographical origin of modern humans is the subject of ongoing scientific debate. The 'multiregional evolution' hypothesis argues that modern humans evolved semi-independently in Europe, Asia and Africa between 100,000 and 40,000 years ago, whereas the 'out of Africa' hypothesis contends that modern humans evolved in Africa between 200 and 100 kyr ago, migrating to Eurasia at some later time. Direct palaeontological, archaeological and biological evidence is necessary to resolve this debate. Here we report the discovery of early Middle Stone Age artefacts in an emerged reef terrace on the Red Sea coast of Eritrea, which we date to the last interglacial (about 125 kyr ago) using U-Th mass spectrometry techniques on fossil corals. The geological setting of these artefacts shows that early humans occupied coastal areas and exploited near-shore marine food resources in East Africa by this time. Together with similar, tentatively dated discoveries from South Africa this is the earliest well-dated evidence for human adaptation to a coastal marine environment, heralding an expansion in the range and complexity of human behaviour from one end of Africa to the other. This new, wide-spread adaptive strategy may, in part, signal the onset of modern human behaviour, which supports an African origin for modern humans by 125 kyr ago.

CytoView. A prototype computer image-based Papanicolaou smear proficiency test

OBJECTIVE

To develop and assess CytoView, a prototype computer image-based cytology proficiency testing (PT) system, as an alternative to glass-slide cervical cytology PT.

STUDY DESIGN

The computer-based PT consists of 10 cases taken from 10 Pap smears, each of which had received a consensus Clinical Laboratory Improvement Amendments-category diagnosis from three pathologists. Each CytoView "case" was the digital representation of > 8,000 microscopic fields, captured from a selected 5 x 10-mm rectangle of a Pap smear. The 5 x 10-mm capture rectangle was selected from the slide's most representative area for its diagnostic category. The CytoView project team developed each case through a multistep process that included image capture, image alignment, correlation of 10x and 40x images, and image display. The 10-slide CytoView PT prototype was then assessed by groups of cytopathologists and cytotechnologists.

RESULTS

The CytoView prototype PT system was developed and assessed.

CONCLUSION

Preliminary evaluation of CytoView indicated potential for this format as a valid and logistically feasible alternative to the traditional glass slide PT format.

Effect of glucose, glucose regulation, and word imagery value on human memory

Changes in memory performance were examined after intake of a glucose (50 g) or saccharin (50 mg) solution in fasted men and women. Glucoregulation was estimated by using a recovery index to categorize participants within each gender as having poor or good recovery. Memory was assessed with word-learning tasks in which the imagery-evoking value of the words was systematically manipulated to yield high- and low-imagery lists. The results showed that men and women characterized as having poor glucose regulation had significantly worse memory performance under the saccharin condition. This decrement was reversed by glucose ingestion. These effects were observed for both low- and high-imagery words. This study supports the hypothesis that poor glucoregulation is associated with poor memory performance even in young healthy participants and that the ingestion of glucose can improve their memory.

Economic evaluation of donepezil for the treatment of Alzheimer's disease in Canada

BACKGROUND

Donepezil is a new drug recently approved in the United States and Canada for the treatment of Alzheimer's disease (AD). We estimated the cost-effectiveness of donepezil 5 mg daily as an adjunct to usual care in the management of persons with mild-to-moderate AD defined as a Mini-Mental Health State Examination (MMSE) score in the range 10 to 26.

METHODS

Treatment effect data as MMSE change-over-baseline scores were obtained from a 30-week placebo-controlled trial of donepezil. MMSE scores beyond observed trial data were estimated using a Markov model with 10 cycles of 24 weeks based on the placebo MMSE progression observed in the trial. Data from AD subjects in the Canadian Study of Health and Aging were used to estimate costs of nursing home care, community services, medications, and caregiver time as a function of MMSE score. A clinic-based cohort study from Alberta was used to estimate the distribution of AD patients by MMSE score presenting for treatment. The effectiveness measure for the economic model was expected time (over 5 years) spent with nonsevere AD (MMSE > or = 10).

RESULTS

Over 5 years of treatment, donepezil is predicted to reduce health care costs by CA$929 per patient but increase caregiver time costs by CA$48 per patient for an overall cost saving to society of CA$882 per patient. Patients not receiving donepezil are predicted to spend 2.21 years of the 5 years in nonsevere AD compared with 2.41 years for treated patients (a gain of just over 2 months). Sensitivity analysis reveals that cost savings per patient increase if more AD patients are assumed to survive to 5 years; however, if donepezil treatment continues when patients' MMSE score falls below 10, the incremental cost is higher for treatment at CA$1554 per patient.

CONCLUSION

Based on the limited available data, our model predicts that the use of donepezil for mild-to-moderate AD in Canada is associated with lower 5-year costs and less time spent with severe AD when compared with the alternative of usual care with no donepezil therapy. As more reliable long-term data become available, these predictions should be confirmed and/or updated.

Effects of age and gender on autonomic control of blood pressure dynamics

Both age and gender influence cardiovascular autonomic control, which in turn may influence the ability to withstand adverse cardiac events and respond to orthostatic stress. The purpose of this study was (1) to quantify age- and gender- related alterations in autonomic control of blood pressure (BP) and (2) to examine the impact of these autonomic alterations on BP response to orthostatic stress. We measured continuous BP and R-R intervals and vasoactive peptide levels in the supine and 60 degrees head-up tilt positions during paced respiration (0.25 Hz) in 89 carefully screened healthy subjects (41 men, 48 women, aged 20 to 83 years). Data were analyzed by gender (age adjusted) and by age group (gender adjusted). During tilt, women had greater decreases in systolic BP than men (-10.2+/-2 versus -1.2+/-3 mm Hg; P=0.02) and smaller increases in low-frequency (sympathetically mediated) BP power (P=0.02). Upright plasma norepinephrine was lower in women (P=0.02). Women had greater supine high-frequency R-R interval power than men (P=0.0001). In elderly subjects, the tilt-induced increase in low-frequency BP power was also diminished (P=0.01), despite higher supine (P=0.02) and similar upright norepinephrine levels compared with younger subjects. Thus, healthy women have less sympathetic influence on BP and greater parasympathetic influence on R-R interval than men. Elderly subjects also have reduced sympathetic influence on BP, but this appears to be more consistent with a reduction in vasomotor sympathetic responsiveness.

Functional and physical association of a cell surface phospholipid and interleukin-2 receptor p55(alpha) subunits

A phosphatidylcholine-like phospholipid expressed in the outer leaflet of the cell membrane shortly after mitogenic activation of T-cells is described, based on the binding of monoclonal antibody 90. 60.3. Expression of the 90.60.3 phospholipid antigen in T-cells is activation-dependent. Once expressed, the 90.60.3 phospholipid is in direct physical association with the interleukin-2 (IL-2) binding domain of IL-2 receptor alpha subunits, but does not affect IL-2 binding. The association is specific, because the 90.60.3 phospholipid is not found in association with other domains of IL-2 receptor alpha subunits, or near IL-2 receptor beta or gamma subunits. Culturing cytokine-dependent cell lines in the presence of monoclonal antibody 90.60.3 potentiates IL-2-dependent cell survival and proliferation in a dose-dependent manner. In contrast, IL-4-dependent responses are not potentiated. Taken together, the data suggest that specific plasma membrane phospholipids expressed in the outer leaflet after T-cell activation associate with the IL-2 binding domain of IL-2 receptor alpha subunits (and perhaps other cytokine receptors), and may play a role in regulating receptor mobility or signal transduction.

Relation between severity of Alzheimer's disease and costs of caring

BACKGROUND

Data from the Canadian Study of Health and Aging (CSHA) were used to examine the relation between severity of Alzheimer's disease, as measured by the Mini-Mental State Examination (MMSE), and costs of caring.

METHODS

The CSHA was a community-based survey of the prevalence of dementia, including subtypes such as Alzheimer's disease, among elderly Canadians. Survey subjects with a diagnosis of possible or probable Alzheimer's disease were grouped into disease severity levels of mild (MMSE score 21-26), mild to moderate (MMSE score 15-20), moderate (MMSE score 10-14) and severe (MMSE score below 10). Components of care available from the CSHA were use of nursing home care, use of medications, use of community support services by caregivers and unpaid caregiver time. Costs were calculated from a societal perspective and are expressed in 1996 Canadian dollars.

RESULTS

The annual societal cost of care per patient increased significantly with severity of Alzheimer's disease. The cost per patient was estimated to be $9451 for mild disease, $16,054 for mild to moderate disease, $25,724 for moderate disease and $36,794 for severe disease. Institutionalization was the largest component of cost, accounting for as much as 84% of the cost for people with severe disease. For subjects living in the community, unpaid caregiver time and use of community services were the greatest components of cost and increased with disease severity.

INTERPRETATION

The societal cost of care of Alzheimer's disease increases drastically with increasing disease severity. Institutionalization is responsible for the largest cost component.

Sensitivity analysis of segment models to estimate the net reaction moments at the L5/S1 joint in lifting

This paper deals with the mathematics of inverse dynamic analysis for calculating the net reaction moments; the sensitivity of the net reaction moments to nine experimental values is quantified and two dynamic models are compared. The results indicate that, among all terms, the external forces in the case of a lower body model and the segment masses in the case of an upper body model contributed the most to differences in the sensitivity of the lumbosacral reaction moment about the transverse axis. About the other axes there was no clear difference between the two body models.