Occurrence of seizure clusters and status epilepticus during inpatient video-EEG monitoring

OBJECTIVE

To investigate the occurrence of status epilepticus and seizure clusters, and the duration until first seizure at epilepsy monitoring units in the United States.

METHODS

The authors examined the inpatient video-EEG monitoring reports of 514 consecutive patients admitted to five comprehensive epilepsy centers during the year 2000. Time to first seizure, seizure clustering, and seizure duration were ascertained from reports and entered into a database.

RESULTS

In 169 admissions with complex partial seizures (CPSs) or secondarily generalized tonic-clonic (2GTC) seizures, there were 5 (3.0%) patients with status epilepticus, 30 (17.8%) with 4-hour seizure clusters, and 82 (48.5%) with 24-hour seizure clusters. There were no statistically significant differences between centers, except that seizure clusters were observed to be less common at the one center with a formal drug withdrawal protocol. The average time to CPS or 2GTC seizure was 2.1 days; the average number of days to nonepileptic event was 1.2 days (p = 0.001).

CONCLUSIONS

Although status epilepticus is uncommon at epilepsy monitoring units, clusters of seizures are common. Intensive monitoring with drug withdrawal must be performed in a highly supervised, hospitalized setting. Inpatient video-EEG monitoring is efficient, with recording of the first epileptic or nonepileptic events in 2 days or less.

Soy protein has a greater effect on bone in postmenopausal women not on hormone replacement therapy, as evidenced by reducing bone resorption and urinary calcium excretion

Recent reports suggest that soy protein may reduce the risk of osteoporosis in peri- and postmenopausal women. The objective of this study was to examine whether soy supplementation exerts beneficial effects on serum and urinary biomarkers of bone metabolism in postmenopausal women, regardless of whether or not they are on hormone replacement therapy (HRT). A total of 71 women were randomly assigned to either soy protein (SP) or milk-based protein (MBP), 40 g daily for 3 months, in a double-blind parallel design. Forty-two women completed the study (20 on SP and 22 on MBP). Overall, both protein supplements positively influenced serum IGF-I, known to correlate with bone formation. However, SP had a more pronounced effect on IGF-I than MBP. Urinary deoxypyridinoline (Dpd) excretion, a specific biomarker of bone resorption, was significantly reduced by SP, but not by MBP when all women were included. Furthermore, women on MBP experienced a 33% increase in urinary calcium excretion, whereas SP did not have such an effect. To evaluate whether SP affects women differently on the basis of their HRT status, data from women on HRT (n = 22) and those not on HRT (n = 20) were analyzed separately. The subanalysis of the data indicated that SP had the greatest impact on serum IGF-I (an increase of 97%) in the women not on HRT. The changes in urinary Dpd due to SP were only observed in women not on HRT, indicating that the overall decrease in Dpd occurred with SP in the absence of HRT. These results indicate that soy protein may positively influence bone and calcium homeostasis in postmenopausal women, particularly those not on HRT.

Cocaine-like subjective effects of nicotine are not blocked by the D1 selective antagonist ecopipam (SCH 39166)

The effects of ecopipam (a D(1) selective antagonist) or triazolam pretreatment on the subjective and physiological effects of intravenously administered nicotine were examined in 10 cigarette-smoking cocaine abusers. Under double-blind, randomized conditions, subjects received oral capsule pretreatment (0, 30 or 100 mg ecopipam, or 0.25 mg/70 kg triazolam), followed 120 min later by an intravenous injection of 2 mg/70 kg nicotine or saline. Subjective ratings, heart rate and blood pressure were assessed before and repeatedly after each intravenous injection. Compared to oral placebo pretreatment, both ecopipam and triazolam pretreatment produced significant elevations in subject-reported capsule effect and observer ratings of sleepiness/sedation. Nicotine increased ratings of 'drug effect', 'rush', 'high', 'stimulated', 'liking', 'good effects' and 'bad effects', and produced modest increases in heart rate and blood pressure. Following both intra-venous saline and nicotine injection, ecopipam tended to reduce heart rate and blood pressure. Although both ecopipam and triazolam lowered several subjective ratings following intravenous saline injection, neither ecopipam nor triazolam affected nicotine subjective effects. In contrast to Romach et al. (Arch Gen Psychiatry 56: 1101-1106, 1999), who showed that pretreatment with ecopipam blocked cocaine subjective effects, the current study found no attenuation of the subjective effects of nicotine, and thus, provides no support for the hypothesis that D(1) receptors mediate the cocaine-like subjective effects of nicotine.

Systematic assessment of clinical practice guidelines for the management of chronic obstructive pulmonary disease

OBJECTIVE

To systematically evaluate the quality of the development of guidelines for the management of chronic obstructive pulmonary disease (COPD).

METHODOLOGY

MEDLINE and Excerpta Medica search for published guidelines, followed by independent evaluation by two reviewers, according to previously reported guideline development quality criteria, on a three-point scale.

RESULTS

Five national COPD guidelines and two international COPD guidelines were retrieved. Reviewers demonstrated good inter-observer agreement in assessing the 10 combined guideline development criteria for the seven guidelines [kappa = 0.66]. Guidelines were only partly multi-disciplinary with little or no consumer input, were up to 48 pages in length, and often lacked practical summaries or management flow charts which could have facilitated retrieval of key management recommendations. Almost all the papers were based upon a consensus approach, rather than evidence based, and methods of resolution of differences of opinion were not stated. Patient outcomes, ethical and medico-legal implications were not addressed and six of the guidelines were sponsored directly or indirectly by a single drug company.

CONCLUSIONS

In spite of COPD guidelines being reported by major national bodies for over a decade now, most fail to meet important criteria for high-quality guideline development, and evaluation of clinical impact remains undetermined.

Soy protein supplementation increases serum insulin-like growth factor-I in young and old men but does not affect markers of bone metabolism

Recent studies suggest that soy protein (SP) protects bone in women; however, its effects on bone metabolism in men have not been investigated. Healthy men (59.2 +/- 17.6 y) were assigned to consume 40 g of either SP or milk-based protein (MP) daily for 3 mo in a double-blind, randomized, controlled, parallel design. Serum insulin-like growth factor-I (IGF-I), which is associated with higher rates of bone formation, was greater (P < 0.01) in men supplemented with SP than in those consuming MP. Serum alkaline phosphatase and bone-specific alkaline phosphatase activities, markers of bone formation, and urinary deoxypyridinoline excretion, a specific marker of bone resorption, were not different between the SP and MP groups. Furthermore, because substantial reductions in bone density occur in men at approximately 65 y of age, data were analyzed separately for men >/=65 y and those <65 y of age. The response to protein supplementation was consistent in the two age groups. The effects of SP on serum IGF-I levels suggest that SP may positively influence bone in men. Longer-duration studies examining the effects of SP or its isoflavones on bone turnover and bone mineral density and content in men are warranted.

Soy isoflavones' osteoprotective role in postmenopausal women: mechanism of action

Ovarian hormone deficiency is a major risk factor for osteoporosis. Current therapies emphasize the use of antiresorptive agents, such as estrogen, calcitonin, and bisphosphonates. These therapies are associated with certain risks and side effects making compliance a major obstacle. Recent findings suggest that a class of synthetic and naturally occurring compounds, selective estrogen receptor modulators, e.g. raloxifene and soy isoflavones can offer attractive alternatives. Evidence for bone-sparing effects of isoflavones relies mainly on animal findings supported by a limited number of human studies. These observations suggest that isoflavones exert their effects on bone by stimulating bone formation and at the same time suppressing bone resorption. However, the precise osteoprotective mechanism of isoflavones remains uncertain and awaiting further clarification. From a clinical point of view, larger and longer duration studies are warranted to enable us to draw clear conclusions in regards to the role of isoflavones on bone.

Skeletal unloading and dietary copper depletion are detrimental to bone quality of mature rats

This study was designed to examine the skeletal response to copper depletion and mechanical unloading in mature animals. In a 2 x 2 experimental design, 5.5-mo-old male Sprague-Dawley rats (n = 36) consumed either the control (AIN-93M) or Cu-depletion ((-)Cu) diet beginning 21 d before suspension and throughout the remainder of the study. Half of the rats in each dietary treatment group were either tail-suspended (TS) or kept ambulatory (AMB) for 28 d. Lower bone mineral densities (BMD) of 5th lumbar vertebra (L5) (P < 0.05) and femur were observed with (-)Cu and TS, but no differences were noted in the BMD of the humerus. Mechanical strength in the femur and vertebra decreased in response to TS, but were unaffected by copper depletion. Urinary deoxypyridinoline, an index of bone resorption, was significantly greater in TS rats, but unaltered by (-)Cu. No changes in serum or bone alkaline phosphatase activity, an indicator of bone formation, were observed. Our findings suggest that TS and (-)Cu decreased BMD in unloaded femur and vertebra but had no effect on normally loaded humerus. Bone loss with TS appeared to be related to accelerated bone resorption. Alterations in bone metabolism and bone mechanical properties in the mature skeleton resulting from (-)Cu warrant further investigation.

Cost comparison of at-home treatment of deep venous thrombosis with low molecular weight heparin to inpatient treatment with unfractionated heparin

AIMS

Low molecular weight heparins (LMWH) permit safe and effective treatment of uncomplicated deep venous thrombosis (DVT) at home. The aim of this study was to evaluate the cost minimization, cost shifting and patient satisfaction associated with at-home DVT treatment using the LMWH enoxaparin, compared to standard inpatient care in an Australian health-care setting.

METHODS

Subjects presenting with a principal diagnosis of uncomplicated DVT to the Emergency Department at The Queen Elizabeth Hospital, Adelaide, were recruited over 1997-1999. Costs to the hospital, to Federal funding (Medicare) and to patients were tracked prospectively, and satisfaction was also measured. Subjects were matched to historical controls (1994-1997) for age, gender and level of comorbidity (same or lower) by two medical officers who were blinded to costs. Control costs were obtained using the clinical costing system Trendstar, and adjusted for consumer price index.

RESULTS

Twenty-eight subjects participated in the at-home programme. Of these, 26 were discharged without any inpatient admission (including one who agreed to self-injection) and two were admitted briefly. Audit demonstrated that only 29% of eligible subjects were managed at home. Mean (SEM) total treatment cost was $756 (76) per patient for at-home, and $2,208 (146) for controls. Minimal cost shifts to patients and to Medicare occurred, and satisfaction was high.

CONCLUSIONS

At-home treatment of uncomplicated DVT using enoxaparin in an Australian metropolitan setting provides effective cost minimization, with little cost-shifting. Our cost minimisation estimates are conservative as most at-home subjects received enoxaparin twice daily (now used once per day) and controls had at least as high comorbidity. However, uptake of the at-home programme was limited.

Catalytic mechanisms and reaction intermediates along the hydrolytic pathway of a plant beta-D-glucan glucohydrolase

BACKGROUND

Barley beta-D-glucan glucohydrolases represent family 3 glycoside hydrolases that catalyze the hydrolytic removal of nonreducing glucosyl residues from beta-D-glucans and beta-D-glucooligosaccharides. After hydrolysis is completed, glucose remains bound in the active site.

RESULTS

When conduritol B epoxide and 2', 4'-dinitrophenyl 2-deoxy-2-fluoro-beta-D-glucopyranoside are diffused into enzyme crystals, they displace the bound glucose and form covalent glycosyl-enzyme complexes through the Odelta1 of D285, which is thereby identified as the catalytic nucleophile. A nonhydrolyzable S-glycosyl analog, 4(I), 4(III), 4(V)-S-trithiocellohexaose, also diffuses into the active site, and a S-cellobioside moiety positions itself at the -1 and +1 subsites. The glycosidic S atom of the S-cellobioside moiety forms a short contact (2.75 A) with the Oepsilon2 of E491, which is likely to be the catalytic acid/base. The glucopyranosyl residues of the S-cellobioside moiety are not distorted from the low-energy 4C(1) conformation, but the glucopyranosyl ring at the +1 subsite is rotated and translated about the linkage.

CONCLUSIONS

X-ray crystallography is used to define the three key intermediates during catalysis by beta-D-glucan glucohydrolase. Before a new hydrolytic event begins, the bound product (glucose) from the previous catalytic reaction is displaced by the incoming substrate, and a new enzyme-substrate complex is formed. The second stage of the hydrolytic pathway involves glycosidic bond cleavage, which proceeds through a double-displacement reaction mechanism. The crystallographic analysis of the S-cellobioside-enzyme complex with quantum mechanical modeling suggests that the complex might mimic the oxonium intermediate rather than the enzyme-substrate complex.

Removal of fractured posts using ultrasonic vibration: an in vivo study

The purpose of this study was to determine the effectiveness of ultrasonic vibration in the removal of fractured posts from teeth under true clinical conditions. Thirty patients (16 men and 14 women with a mean age of 51 yr, SD 13.13) had ultrasonic vibration applied to the side of a fractured post fragment after creation of a small gutter around the fragment. A piezoelectric ultrasonic scaler was used to apply the vibration for two 15-s periods and then 30-s periods until the post fragment became loose. There was a significant correlation (r = 0.52, p = 0.003) between the cemented length of post fragment (mean length 3.8 mm, SD 1.39) and the time of ultrasonic vibration application (mean time 2.05 min, SD 1.62), but the correlation between post diameter and ultrasonic time did not reach statistical significance (r = 0.35, p = 0.059). The mean ultrasonic time was approximately 25% of that found in previous studies on post removal from extracted teeth probably because of suboptimal cementation of posts in the clinical situation.

Automated attention flags in chronic disease care planning

OBJECTIVES

To assess the value of computerised decision support in the management of chronic respiratory disease by comparing agreement between three respiratory specialists, general practitioners (care coordinators), and decision support software.

METHODS

Care guidelines for two chronic obstructive pulmonary disease projects of the SA HealthPlus Coordinated Care Trial were formulated. Decision support software, Care Plan On-Line (CPOL), was created to represent the intent of these guidelines via automated attention flags to appear in patients' electronic medical records. For a random sample of 20 patients with care plans, decisions about the use of nine additional services (eg, smoking cessation, pneumococcal vaccination) were compared between the respiratory specialists, the patients' GPs and the CPOL attention flags.

RESULTS

Agreement among the specialists was at the lower end of moderate (intraclass correlation coefficient [ICC], 0.48; 95% CI, 0.39-0.56), with a 20% rate of contradictory decisions. Agreement with recommendations of specialists was moderate to poor for GPs (kappa, 0.49; 95% CI, 0.33-0.66) and moderate to good for CPOL (kappa, 0.72; 95% CI, 0.55-0.90). CPOL agreement with GPs was moderate to poor (kappa, 0.41; 95% CI, 0.24-0.58). GPs were less likely than specialists or CPOL to decide in favour of an additional service (P<0.001). CPOL was 87% accurate as an indicator of specialist decisions. It gave a 16% false-positive rate according to specialist decisions, and flagged 61% of decisions where GPs said No and specialists said Yes.

CONCLUSIONS

Automated decision support may provide GPs with improved access to the intent of guidelines; however, further investigation is required.

P-glycoprotein efflux at the blood-brain barrier mediates differences in brain disposition and pharmacodynamics between two structurally related neurokinin-1 receptor antagonists

CP-122721 and CP-141938 are potent and selective neurokinin-1 (NK(1)) receptor antagonists with very different brain disposition and potency in models of centrally mediated activity. These investigations sought to determine whether differences in potency were related to differences in P-glycoprotein (P-gp) transport at the blood-brain barrier. Both compounds stimulated ATPase activity of human recombinant MDR1 with similar kinetic parameters. Cell-associated drug concentrations of CP-141938 were 9.4-fold lower in KBV1 cells expressing P-gp compared with KB3.1 control cells. In Madin-Darby canine kidney (MDCK) cells expressing human MDR1, asymmetric transport of CP-141938 was 5-fold higher than in wild-type MDCK cells, whereas no asymmetry was observed with CP-122721. In agreement with these differences in cellular transport, the differences in brain/plasma ratio between mdr1a/b(-/-) and FVB mice 1 h following a 3 mg/kg s.c. dose were 3- and 50-fold for CP-122721 and CP-141938, respectively. The effect of inhibiting P-gp efflux on the effects of these agents was evaluated using GR73632-induced foot tapping in gerbils as a model to measure centrally mediated NK(1) antagonism. When gerbils were pretreated with the P-gp inhibitor MS-073 (50 mg/kg s.c.), there was no effect on the activity of CP-122721 (0.05 mg/kg), whereas the percent reversal for CP-141938 (10 mg/kg) increased from 60 to 100%. In gerbils, the brain/plasma ratio for CP-122721 was unaffected by MS-073 pretreatment, whereas the brain/plasma ratio for CP-141938 brain concentrations increased 13-fold. This suggested that P-gp efflux influences the brain disposition and pharmacologic activity of CP-141938, but not CP-122721. Complete response curves for CP-141938 were then determined with respect to dose, and drug concentration in the plasma and brain in the presence and absence of MS-073 pretreatment. The dose and plasma concentration-response curves of CP-141938 were shifted to the left in the presence of MS-073, yet brain concentrations associated with the response were unchanged. This suggested that once in the brain the interaction of CP-141938 with the NK(1) receptor was not affected by P-gp transport. In conclusion, these studies show that brain disposition and centrally mediated in vivo activity of NK(1) antagonists can be profoundly affected by P-gp transport and that such transport should be considered during the design of new agents.

Prolonged in vivo residence times of antibody fragments associated with albumin

Antibody fragments can be expressed at a high level in microbial systems, but they may have limited therapeutic value because they are rapidly eliminated from the body. We demonstrate here that site-specific conjugation or binding of bacterially derived Fab' to the long-lived protein serum albumin allows full retention of the antibody's binding characteristics while imparting the albumin's longevity in vivo. In rats the area under the curve for Fab' conjugated to rat serum albumin was 17-fold greater than for the control of Fab' conjugated to cysteine. Again, a bispecific F(ab')(2) with specificity for rat serum albumin showed an area under the curve about 8-fold greater than did a F(ab')(2) without specificity to albumin. Genetic fusions of scFv to albumin were similarly long-lived and could be expressed in yeast to provide the basis of a cost-effective production system.

Physiological, subjective and reinforcing effects of oral and intravenous cocaine in humans

RATIONALE

There is little comparative information on the qualitative similarity, relative potency and reinforcing effects of oral cocaine versus cocaine administered via other routes.

METHODS

The present study used a within-subject, double-blind, double-dummy design to compare the physiological, subjective and reinforcing effects of placebo and oral (62.5, 125, 250 mg/70 kg) and intravenous (IV) (12.5, 25, 50 mg/70 kg) cocaine in volunteers with histories of cocaine abuse.

RESULTS

Cocaine produced dose-dependent increases on heart rate and blood pressure, with effects lasting longer after oral than IV cocaine. Subjective ratings (e.g., "rush," "drug effect," "liking") were qualitatively similar and dose-dependently increased after oral and IV administration, and the duration of effects was similar under both routes. On a money versus drug choice measure of reinforcement, the monetary amounts at which participants chose drug over money increased as a function of cocaine dose under both routes of administration. At doses that produced comparable subjective, physiological, and reinforcing effects, oral cocaine was not identified as cocaine as frequently as IV cocaine. Across measures, the data suggested that IV cocaine was approximately 10 times more potent than oral cocaine.

CONCLUSIONS

Overall, the results of this study support qualitatively similar effects of oral and IV cocaine and suggest that oral cocaine may be an effective tool for studying cocaine's effects in human laboratory studies.

Corticosteroid-Sparing Effect of Etanercept in Idiopathic Panuveitis Resistant to Immunosuppressive Therapy

Uveitis, an inflammatory eye disease with varying immunopathogenic mechanisms, may be associated with autoimmune disorders, may be secondary to infection, or may be idiopathic. Response to treatment of uveitis is inconsistent. In this report we describe an adult with idiopathic panuveitis who attempted to lower his oral corticosteroid dose from intolerable levels but was unable to do so because of the reappearance of symptoms. His 8-year course was managed with ocular and systemic corticosteroids, methotrexate, and cyclosporine, which allowed only partially successful control of his ocular inflammation. Complete control was not achieved until the addition of etanercept. With this case report we are the first to describe the complete response of idiopathic panuveitis to etanercept. Our success with this patient strongly supports the critical role of tumor necrosis factor in the immunopathogenesis of some cases of idiopathic panuveitis. Furthermore, etanercept offers a relatively nontoxic, safe option in cases of panuveitis that are unresponsive to traditional immunosuppressive therapy.

The Iowa radon lung cancer study--phase I: Residential radon gas exposure and lung cancer

Exposure to high concentrations of radon (222Rn) progeny produces lung cancer in both underground miners and experimentally-exposed laboratory animals. The goal of the study was to determine whether or not residential radon exposure exhibits a statistically significant association with lung cancer in a state with high residential radon concentrations. A population-based, case-control epidemiologic study was conducted examining the relationship between residential radon gas exposure and lung cancer in Iowa females who occupied their current home for at least 20 years. The study included 413 incident lung cancer cases and 614 age-frequency-matched controls. Participant information was obtained by a mailed-out questionnaire with face-to-face follow-up. Radon dosimetry assessment consisted of five components: (1) on-site residential assessment survey; (2) on-site radon measurements; (3) regional outdoor radon measurements; (4) assessment of subjects' exposure when in another building; and (5) linkage of historic subject mobility with residential, outdoor, and other building radon concentrations. Histologic review was performed for 96% of the cases. Approximately 60% of the basement radon concentrations and 30% of the first floor radon concentrations of study participants' homes exceeded the US Environmental Protection Agency action level of 150 Bq m(-3) (4 pCi l(-1)). Large areas of western Iowa had outdoor radon concentrations comparable to the national average indoor value of 55 Bq m(-3) (1.5 pCi l(-1)). Excess odds of 0.24 (95% CI = -0.05-0.92) and 0.49 (95% CI = 0.03-1.84) per 11 WLM(5-19) were calculated using the continuous radon exposure estimates for all cases and live cases, respectively. Slightly higher excess odds of 0.50 (95% CI = 0.004-1.80) and 0.83 (CI = 0.11-3.34) per 11 WLM(5-19) were noted for the categorical radon exposure estimates for all cases and the live cases. A positive association between cumulative radon gas exposure and lung cancer was demonstrated using both categorical and continuous analyses. The risk estimates obtained in this study indicate that cumulative radon exposure presents an important environmental health hazard.

Treatment of status epilepticus

The approach to treatment of status epilepticus has changed because of the demonstration of decreased mortality with rapid intervention, completion of a randomized, double-blind VA Cooperative study comparing first-line agents, and further understanding of the pathophysiologic changes discovered in experimental animal studies. This article reviews the treatments of generalized convulsive status epilepticus in the prehospital, emergency department, and intensive care unit settings.

Analysis of inhibitor binding in influenza virus neuraminidase

2,3-didehydro-2-deoxy-N:-acetylneuraminic acid (DANA) is a transition state analog inhibitor of influenza virus neuraminidase (NA). Replacement of the hydroxyl at the C9 position in DANA and 4-amino-DANA with an amine group, with the intention of taking advantage of an increased electrostatic interaction with a conserved acidic group in the active site to improve inhibitor binding, significantly reduces the inhibitor activity of both compounds. The three-dimensional X-ray structure of the complexes of these ligands and NA was obtained to 1.4 A resolution and showed that both ligands bind isosterically to DANA. Analysis of the geometry of the ammonium at the C4 position indicates that Glu119 may be neutral when these ligands bind. A computational analysis of the binding energies indicates that the substitution is successful in increasing the energy of interaction; however, the gains that are made are not sufficient to overcome the energy that is required to desolvate that part of the ligand that comes in contact with the protein.

The structure of the fusion glycoprotein of Newcastle disease virus suggests a novel paradigm for the molecular mechanism of membrane fusion

BACKGROUND

Membrane fusion within the Paramyxoviridae family of viruses is mediated by a surface glycoprotein termed the "F", or fusion, protein. Membrane fusion is assumed to involve a series of structural transitions of F from a metastable (prefusion) state to a highly stable (postfusion) state. No detail is available at the atomic level regarding the metastable form of these proteins or regarding the transitions accompanying fusion.

RESULTS

The three-dimensional structure of the fusion protein of Newcastle disease virus (NDV-F) has been determined. The trimeric NDV-F molecule is organized into head, neck, and stalk regions. The head is comprised of a highly twisted beta domain and an additional immunoglobulin-like beta domain. The neck is formed by the C-terminal extension of the heptad repeat region HR-A, capped by a four-helical bundle. The C terminus of HR-A is encased by a further helix HR-C and a 4-stranded beta sheet. The stalk is formed by the remaining visible portion of HR-A and by polypeptide immediately N-terminal to the C-terminal heptad repeat region HR-B. An axial channel extends through the head and neck and is fenestrated by three large radial channels located approximately at the head-neck interface.

CONCLUSION

We propose that prior to fusion activation, the hydrophobic fusion peptides in NDV-F are sequestered within the radial channels within the head, with the central HR-A coiled coil being only partly formed. Fusion activation then involves, inter alia, the assembly of a complete HR-A coiled coil, with the fusion peptides and transmembrane anchors being brought into close proximity. The structure of NDV-F is fundamentally different than that of influenza virus hemagglutinin, in that the central coiled coil is in the opposite orientation with respect to the viral membrane.

Impact of the physician's participatory style in asthma outcomes and patient satisfaction

OBJECTIVES

To identify factors associated with asthma patients' perceptions of the propensity of pulmonologists to involve them in treatment decision-making, and its association with asthma outcomes.

DESIGN

Cross-sectional observational study performed from June 1995 to December 1997.

SETTING

Pulmonary unit of a university teaching hospital.

PATIENTS

Adult patients with asthma (n = 128).

MEASUREMENTS AND RESULTS

By patient self-report, mean physician's participatory decision-making (PDM) style score was 72 (maximum 100, 95% CI 65, 79). PDM scores were significantly correlated (P < .0001) with the duration of clinic visits (r = .63), patient satisfaction (r = .53), duration of tenure of doctor-patient relationship (r = .37), and formal education (r = .22, P = .023). Significantly higher PDM style scores were reported when visits lasted longer than 20 minutes and when a patient had a >6-month relationship with a particular doctor. PDM scores were also significantly correlated with possession of a written asthma action plan (r = .54, P < .0001), days affected by asthma (r = .36, P = .0001), asthma symptoms (r = .23, P = .017), and preferences for autonomy in asthma management decisions (r = .28, P = .0035). Those with PDM scores <50 reported significantly lower quality of life for all domains of a disease-specific instrument and the Short-Form 36 health survey version 1.0. In multiple regression analysis, PDM style was associated with the length of the office visit and the duration of tenure of the physician-patient relationship (R2 = 0.47, P = .0009). The adjusted odds ratio, per standard deviation decrease in PDM scores, for an asthma hospitalization was 2.0 (95% CI 1.2, 3.2) and for rehospitalization was 2.5 (95% CI 1.2, 4.2).

CONCLUSIONS

Patients' report of their physician's PDM style is significantly associated with health-related quality of life, work disability, and recent need for acute health services. Organizational factors, specifically longer visits and more time seeing a particular physician, are independently associated with more participatory visits. This has significant policy implications for asthma management.

Asthma, inhaled corticosteroid use, and bone mass in prepubertal children

The aim of this cross-sectional study was to describe the role of asthma, asthma severity, and medication usage in bone mineralization of prepubertal children. Asthma severity, medication usage, and physical activity were assessed by questionnaire and objective measures in 330 children. Bone densitometry and body composition were measured by dual-energy x-ray absorptiometry. Asthma ever was reported by 110 subjects (33%). A diagnosis of asthma was not associated with any deficit in bone mass, whereas usage of inhaled corticosteroids (ICS) in the last year (but not past use) was associated with deficits in bone in the total body (only after adjustment for confounders), particularly for doses of > or =400 microg/day. These observations support current recommendations with regard to ICS usage in children, but require confirmation in longitudinal studies.

Effects of alprazolam, caffeine, and zolpidem in humans trained to discriminate triazolam from placebo

This study compared the discriminative stimulus effects of zolpidem, a nonbenzodiazepine hypnotic, to benzodiazepines. Eight participants learned to discriminate triazolam (0.35 mg/70 kg) from placebo. The discriminative stimulus effects, self-reported subjective effects, and performance effects of triazolam (0.05-0.35 mg/70 kg), alprazolam (0.25-1.75 mg/70 kg), zolpidem (2.5-35 mg/70 kg) and caffeine (75-525 mg/70 kg) were assessed under two-response and novel-response drug discrimination procedures. Under the two-response procedure, triazolam, alprazolam and zolpidem fully substituted for triazolam and caffeine did not. Under the novel-response procedure, triazolam and alprazolam substituted for triazolam and zolpidem partially substituted for triazolam. Zolpidem, but not triazolam or alprazolam, also produced some novel responding. Caffeine produced both placebo-appropriate and novel responding. The self-reported effects of triazolam, alprazolam and zolpidem were similar. Overall, zolpidem produced similar, but not identical, effects as the benzodiazepines.

Patient preferences for autonomy in decision making in asthma management

BACKGROUND

Lower patient preferences for autonomy in management decision making during asthma exacerbations have been associated with an increased risk for future hospital admissions. We sought to examine patient preferences for asthma self-management autonomy, and the clinical and psychosocial factors associated with autonomy preferences.

METHODS

A cross sectional observational study was performed with data collected between June 1995 and December 1997 of 212 adult patients with moderate to severe asthma managed, at least in part, at two teaching hospitals. Subjects completed a survey of autonomy preferences, quality of life, clinical morbidity and health service use, asthma knowledge, self-efficacy, coping styles, and psychosocial measures.

RESULTS

Patients preferred clinicians to assume the major role in most decision making about their management. However, patients wished to remain in control in choosing when to seek care and wanted to share decisions regarding initiating changes in medications during a moderate exacerbation. Multiple regression analysis showed that concerns about adverse effects of medications, education level, an active coping style, perceptions of the propensity of physicians to involve them in treatment decision making, and concerns about costs causing delays in seeking medical care were associated with preferences for autonomy in decision making. Autonomy preferences were not related to measures of concurrent clinical asthma control or health related quality of life.

CONCLUSIONS

In a group of patients with moderate to severe asthma, a high proportion of whom were from socioeconomically disadvantaged backgrounds, education level, perceived physician behaviour, cost barriers to care, and psychosocial factors (but not clinical asthma control or management) were related to patient preferences for autonomy in management decision making during asthma exacerbations. This has implications for asthma action plans and design of self-management programmes.

Topical permethrin exposure inhibits antibody production and macrophage function in C57Bl/6N mice

Permethrin was applied to the shaved dorsal interscapular region of C57Bl/6N mice at doses of 0.5, 1.5 or 5.0 microl/day. These doses corresponded to approximately 22-220 mg/kg/day topical insecticide. Mice were exposed to permethrin in this manner daily for 10 or 30 consecutive days, or every other day for 7 or 14 exposures. The splenic macrophage chemiluminescent response was depressed in a dose-dependent manner at 2 and 10 days post-exposure to permethrin. Phagocytic ability of macrophages was not inhibited. Antibody production as shown by plaque-forming cell (PFC) assay decreased significantly after 10 consecutive days of exposure to permethrin. These data indicate that topical permethrin exposure may produce systemic immune effects.

Bilateral dissected spleens and thymuses in rodents exhibit homogeneity in leukocyte markers

Histopathologic evaluation and/or archiving of sections of spleen or thymus from all study animals may be mandated by study protocol (e.g., Toxic Substances Control Act-compliant studies). In such cases, whole spleen or thymus is not available for immunophenotyping. It has not been previously demonstrated that immunologic data representative of whole organs can be reliably obtained using a section of the spleen or using one thymic lobe. Light-scatter characteristics and immune cell-surface antigen expression were therefore compared in the right and left halves of the spleen and in the right and left thymic lobes of young adult female C57B1/6 mice and Sprague-Dawley rats. Antigens compared were: mouse spleen - CD11b, CD45R, CD90; rat spleen - CD11b, CD45RA, Pan-T/Ox-52; mouse and rat thymus - CD4, CD8a. There were no significant differences in distribution of cells by size or by expression level for any of these antigens when the right part of the organs was compared to the left part. These data indicate that use of entire spleen or both thymic lobes is not required to reliably quantify resident immune cell subpopulations.

Antibody isotypes in sera of equine fetuses aborted due to Leptospira interrogans serovar pomona-type kennewicki infection

Leptospira-specific antibody isotypes in sera of late term equine fetuses aborted due to Leptospira interrogans serovar pomona-type kennewicki infection were characterized and compared with those of their dams. IgM was the dominant Leptospira-Specific isotype in both fetuses and mares. However, IgGa was the isotype in highest concentration in petal sera and strong Leptospira-specific IgGa but no IgGb and little or no IgG(T) were detected. In contrast, although IgGb was quantitatively the dominant isotype in mares serum, Leptospira-specific serum IgG in aborting mares was dominated by IgG(T) but also included large amounts of IgGa and IgGb. IgGa and IgGb were quantitatively the dominant isotypes in sera of fetuses and mares, respectively. Affinity purified IgGa from fetuses did not agglutinate leptospires but serum devoid of IgGa did, suggesting that IgM is the principal agglutinating antibody. It is concluded that the equine fetus is deficient in IgGb and IgG(T) synthesis.

Nonspecific stimulation of the maternal immune system. I. Effects On teratogen-induced fetal malformations

BACKGROUND

Maternal immune stimulation has reported, but unconfirmed, efficacy for reducing chemical-induced morphologic defects in mice.

METHODS

Teratogenic chemicals (2,3,7, 8-tetrachlorodibenzo-p-dioxin [TCDD], ethyl carbamate [urethane], methylnitrosourea [MNU], or valproic acid [VA]) were given to pregnant mice to induce cleft palate (TCDD, urethane), digital defects (urethane, MNU), or exencephaly (VA). Before teratogen administration, the immune system of female mice was stimulated by intraperitoneal (IP) administration of pyran copolymer or attenuated bacillus Calmette Guérin (BCG), or by footpad injection with Freund's complete adjuvant (FCA).

RESULTS

Fetal defects caused by all four chemicals studied were reduced by maternal immunostimulation, sometimes dramatically. In addition to reducing VA-induced exencephaly, immunostimulation with FCA resulted in fetal mice displaying anury (absence of tails). Activated maternal immune cells could not be detected in fetal circulation using flow cytometry and a fluorescent cell-tracking probe.

CONCLUSIONS

For the chemicals tested, maternal immune stimulation has efficacy in reducing fetal defects. Immune protection against teratogenesis may be an indirect effect of maternal immune cell activation.

Nonspecific stimulation of the maternal immune system. II. Effects on gene expression in the fetus

BACKGROUND

Maternal immune stimulation reduces malformations caused by chemical teratogens. Mechanisms for this effect are not known. Altered expression of regulatory molecules (e.g., transforming growth factor [TGF-beta], tumor necrosis factor-alpha [TNF-alpha]) has been reported in fetuses from immunostimulated mice, which may affect gene expression. Expression of selected genes that function to control proliferation, differentiation, or apoptosis was evaluated in chemical-exposed fetuses, with or without maternal immunostimulation.

METHODS

Ethyl carbamate (urethane) was given to pregnant ICR mice on day 10 of gestation to induce cleft palate. Before teratogen administration, the immune system of the female mice was stimulated by footpad injection with Freund's complete adjuvant (FCA) or by intraperitoneal injection with interferon-gamma (IFN-gamma).

RESULTS

Maternal immunostimulation with interferon-gamma (IFN-gamma) decreased severity of the cleft palate lesion caused by urethane, while FCA decreased both incidence and severity of cleft palate. Gestation day 14 fetuses from urethane-exposed mothers displayed decreased expression of cell cycle/apoptotic genes bcl2alpha, bcl2beta, pkCalpha, and p53 in fetal heads. Immune stimulation with IFN-gamma-normalized expression of bcl2alpha, bcl2beta, and pkCalpha to control levels. Urethane also decreased the ratio of expression of bclalpha/p53, bclbeta/p53, and pkCalpha/p53, while maternal injection with IFN-gamma restored these expression ratios to control levels. Maternal immunization with FCA also significantly increased bcl2alpha/p53, bcl2beta/p53, and pkCalpha/p53 gene expression ratios.

CONCLUSIONS

These results suggest that (1) the maternal immune system may possess heretofore unrecognized regulatory activity in fetal development, and (2) protection against urethane-induced cleft palate may be mediated through maternal immune regulation of fetal gene expression.

Health effects of daily indoor nitrogen dioxide exposure in people with asthma

Household gas appliances produce nitrogen dioxide (NO2), which may be associated with an increase in symptoms in asthmatics. The relationship between indoor NO2 exposure, and respiratory symptoms in people with asthma was evaluated. Self-reported asthmatics (n=125) wore lapel badges that measured NO2 daily over 6 weeks at home. Outdoor pollutants, spores and meteorological parameters were measured daily, in addition to smoking status and demographic factors. Seven asthma symptoms were recorded in diaries, for analysis by same day and also with 1 day lag exposures, using a generalized estimating equation. Significant interactions were demonstrated between NO2 at age < or =14 yrs, with respect to the symptoms of chest tightness on the same day (odds ratio (OR): 1.29, 95% confidence interval (CI): 1.16-1.43) and with a 1 day lag (OR: 1.29, 95% CI: 1.14-1.46), breathlessness on exertion with a 1 day lag (OR: 1.13, 95% CI: 1.00-1.28), daytime asthma attacks on the same day (OR: 1.13, 95% CI: 1.02-1.26) night asthma attacks on the same day (OR: 1.16, 95% CI:1.03-1.30) and with a 1 day lag (OR: 1.15, 95% CI; 1.03-1.29) after adjustment for potential confounders. A significant interaction between NO2 and age 35-49 yrs was demonstrated for coughs with a 1 day lag (OR: 1.15, 95% CI: 1.01-1.31). Daily personal exposures to NO2 are associated with asthmatic symptoms in children.

In vitro kinetics of coumarin 3,4-epoxidation: application to species differences in toxicity and carcinogenicity

Coumarin, a natural product and fragrance ingredient, is a well recognized rat liver toxicant, and dietary administration at toxic dosages increased the incidence of rat cholangiocarcinomas and parenchymal liver-cell tumors in a chronic bioassay. Hepatotoxicity in rats is site- and species-specific, and is thought to result from the formation of coumarin 3,4-epoxide and its rearrangement product, o-hydroxyphenylacetaldehyde (o-HPA). The goals of the current study were to describe the in vitro kinetics of the metabolic activation of coumarin, and determine whether species differences in susceptibility to liver injury correlate with coumarin bioactivation determined in vitro. Coumarin 3,4-epoxidation was quantified via the formation of o-HPA in pooled hepatic microsomes from female B6C3F1 mice, male F344 rats, and individual humans (n = 12 subjects), and the apparent kinetic constants for o-HPA production were calculated using nonlinear regression and fitting to either a one-enzyme or two-enzyme model. Eadie-Hofstee analyses indicated that o-HPA formation was biphasic in both rat and mouse liver. Although the apparent high affinity K:(m) in rat and mouse liver microsomes was 38.9 and 47.2 microM, respectively, the overall rate of o-HPA formation was far greater in mouse than in rat liver microsomes. Furthermore, the total clearance (CL(int)) of coumarin via o-HPA formation in mouse liver microsomes was 4-fold greater than in rat liver microsomes. Since mice are relatively resistant to hepatotoxicity, the data indicated that rates of o-HPA formation in rat and mouse liver microsomes were not directly predictive of liver toxicity in vivo, and further suggested that o-HPA detoxification played a role in modulating coumarin-mediated toxicity. The current studies also indicated that coumarin 3,4-epoxidation in human hepatic microsomes was minimal. In human liver microsomes (n = 12), the kinetics of o-HPA formation were best described by a single enzyme model, with the K(m) for o-HPA formation ranging from 1320-7420 microM. In the most active human sample, the intrinsic clearance of coumarin via the 3,4-epoxidation pathway was 1/9 and 1/38 that of the rat and mouse, respectively. The in vitro kinetics of o-HPA formation, and in particular, the large quantities of coumarin required for o-HPA production in human liver microsomes, strongly suggest that humans are unlikely to produce toxicologically relevant concentrations of this metabolite following low level coumarin exposures.

High-level periplasmic expression in Escherichia coli using a eukaryotic signal peptide: importance of codon usage at the 5' end of the coding sequence

We investigated the ability of signal peptides of eukaryotic origin (human, mouse, and yeast) to efficiently direct model proteins to the Escherichia coli periplasm. These were compared against a well-characterized prokaryotic signal peptide-OmpA. Surprisingly, eukaryotic signal peptides can work very efficiently in E. coli, but require optimization of codon usage by codon-based mutagenesis of the signal peptide coding region. Analysis of the 5' of periplasmic and cytoplasmic E. coli genes shows some codon usage differences.

Active site modulation in the N-acetylneuraminate lyase sub-family as revealed by the structure of the inhibitor-complexed Haemophilus influenzae enzyme

The N-acetylneuraminate lyase (NAL) sub-family of (beta/alpha)(8) enzymes share a common catalytic step but catalyse reactions in different biological pathways. Known examples include NAL, dihydrodipicolinate synthetase (DHDPS), d-5-keto-4-deoxyglucarate dehydratase, 2-keto-3-deoxygluconate aldolase, trans-o-hydroxybenzylidenepyruvate hydrolase-aldolase and trans-2'-carboxybenzalpyruvate hydratase-aldolase. Little is known about the way in which the three-dimensional structure of the respective active sites are modulated across the sub-family to achieve cognate substrate recognition. We present here the structure of Haemophilus influenzae NAL determined by X-ray crystallography to a maximum resolution of 1.60 A, in native form and in complex with three substrate analogues (sialic acid alditol, 4-deoxy-sialic acid and 4-oxo-sialic acid). These structures reveal for the first time the mode of binding of the complete substrate in the NAL active site. On the basis of the above structures, that of substrate-complexed DHDPS and sequence comparison across the sub-family we are able to propose a unified model for active site modulation. The model is one of economy, allowing wherever appropriate the retention or relocation of residues associated with binding common substrate substituent groups. Our structures also suggest a role for the strictly conserved tyrosine residue found in all active sites of the sub-family, namely that it mediates proton abstraction by the alpha-keto acid carboxylate in a substrate-assisted catalytic reaction pathway.

The intersection of health informatics and evidence-based medicine: computer-based systems to assist clinicians

Evidence-based medicine and health informatics may assist clinicians contend with the current barriers to the integration of evidence-based "best practice" into typical healthcare settings. Computer-based decision support systems can improve the process of care, but whether they improve patient outcomes in a cost-effective manner is uncertain.

Promoting physical activity in general practice: a controlled trial of written advice and information materials

OBJECTIVE

To investigate the impact of a simple written prescription for physical activity given by a general practitioner and the effect of supplementing this with mailed information materials about physical activity.

METHODS

A controlled trial was conducted in 27 general practices in New South Wales, Australia. Subjects were sequential routine care patients between 25 and 65 years old. Controls (n = 386) were recruited first, and intervention subjects two weeks later. Intervention subjects were randomised to receive a prescription only (n = 380) or a prescription plus a mailed booklet (n = 376). Self reported physical activity levels were measured by interview at baseline, 6-10 weeks, and seven to eight months.

RESULTS

By intention to treat, the average changes in minutes of total physical activity did not differ significantly between the groups. Inactive people in the prescription plus supplementary booklet group were significantly more likely than controls to report an increase in their physical activity by at least 60 min/week after 6-10 weeks (odds ratio 1.58, 95% confidence interval 1.06 to 2.35). No significant short term improvements in self reported activity were shown in the prescription only group. In the supplemented group, the proportion reporting an increase in physical activity to 3,344 kJ/week at 6-10 weeks was not significant, and neither intervention group showed significant increases in any of the outcome measures at seven to eight months by intention to treat. Treatment received analysis showed greater improvements in intervention groups, especially the prescription plus booklet group, in which the odds of inactive people in this group reporting increased activity became significant at seven to eight months.

CONCLUSIONS

A prescription for physical activity from a general practitioner, supplemented by additional written materials, can lead to modest short term improvements in self reported physical activity levels among inactive patients. A prescription alone was found not to be effective.

Gross morphology and topography of the adult intestinal tract of the tilapian fish, Oreochromis niloticus L

The intestinal tract of the Nile tilapia, Oreochromis niloticus L., follows a complex course involving multiple loops and coils arranged in a previously undescribed form. From cranial to caudal, five principal regions were identified and designated as the hepatic loop (HL), proximal major coil (PMC), gastric loop (GL), distal major coil (DMC), and terminal segment (TS). The first four of these regions each possessed a reversal flexure and thus could be divided into proximal and distal limbs. Only the terminal segment was straight and undivided. The PMC and DMC were disposed in a spiral, cone-shaped mass (spiral intestine) - their proximal and distal limbs are thus designated as centripetal and centrifugal limbs. These spiral limbs were arranged with each successive limb nested internal to the previous one. Beginning from the stomach, the complete course of the gut including designations of the subdivisions of the major regions was as follows: proximal limb of the HL, distal limb of the HL, centripetal limb of the PMC, centrifugal limb of the PMC, proximal limb of the GL, distal limb of the GL, centripetal limb of the DMC, centrifugal limb of the DMC, and the TS. Though the topographical relations of the various gut loops permitted ready identification of each, external surface features were so similar among the segments that extirpated segments of gut could not be identified as to region of origin. The nesting of successive intestinal loops of the spiral intestine in this fish is novel among patterns previously described, and also among the more intricate of those that have been described.

Factors associated with hospital admissions and repeat emergency department visits for adults with asthma

BACKGROUND

A small proportion of patients with asthma account for a disproportionate number of acute health service events. To identify whether factors other than severity and low socioeconomic status were associated with this disproportionate use, a prospective study was undertaken to examine management and psychosocial factors associated with increased risk for admission to hospital with asthma and repeat visits to the emergency department over a 12 month period.

METHODS

A total of 293 patients with moderate or severe asthma managed at least in part at two teaching hospitals completed surveys of clinical status, acute events, sociodemographic, and psychological variables.

RESULTS

Twenty three percent had a single admission to hospital and 16% had two or more hospital admissions. Twenty six percent had one emergency department visit and 32% had two or more visits to the emergency department. In a multiple logistic regression model, adjusted for age, sex, education and income, odds ratios (95% CI) for baseline factors associated with hospital admissions over the next 12 months were: moderate severity compared with severe asthma 0.6 (0.2 to 0.9); no hospital admissions in the past 12 months 0.1 (0.01 to 0.2); not possessing a written asthma action plan 4.0 (1.5 to 10.7); less use of an avoidance coping style 0.4 (0.3 to 0.7); lower preferences for autonomy in asthma management decisions 1.4 (0.96 to 2.0). Adjusted odds ratios (95% CI) for repeat emergency department visits were: moderate asthma severity 0.3 (0.1 to 0.8); current regular use of oral corticosteroids 10.0 (3.1 to 32.4); a hospital admission in the past 12 months 2.9 (1.8 to 4.8); not possessing a written asthma action plan 2.2 (1.1 to 5.6); less dislike of asthma medications 0.7 (0.5 to 0.9).

CONCLUSIONS

In addition to factors relating to severity, not possessing a written asthma action plan, avoidance coping, and attitudes to self-management were related to acute use of health services in this at risk group. Interventions need to address or take these factors into account to reduce asthma morbidity.

Heavy metal concentrations in surface sediments in a nearshore environment, Jurujuba Sound, Southeast Brazil

Sixty-four surface sediment samples and seven cored samples were collected from the partially closed bay of Jurujuba Sound, an inlet of Guanabara Bay in Southeast Brazil. Analysis of metals, including Pb, Zn, Ni, Cu and Cr, shows levels consistent with those typically found in urbanised and industrialised estuarine environments. Metal enrichment is concentrated around the inshore margin of the Sound and is significantly in excess of background, geological concentrations observed in basal muds from the seven cores. In the absence of industrialisation within the steep, but limited catchment that feeds into the Sound, the metal enrichment, particularly of Pb, Zn and Cu, is ascribed to the uncontrolled discharge of untreated sewage waste and urban surface runoff. This has increased markedly since the beginning of rapid urbanisation following the linking of the area by bridge to Rio de Janeiro in 1974.

The APS adapter protein couples the insulin receptor to the phosphorylation of c-Cbl and facilitates ligand-stimulated ubiquitination of the insulin receptor

The APS adapter protein is rapidly tyrosine-phosphorylated following insulin stimulation. In insulin-stimulated 3T3-L1 adipocytes, APS co-precipitated with phosphorylated c-Cbl. In CHO.T-APS cells overexpressing the insulin receptor and APS, APS co-precipitated with c-Cbl but not in CHO.T cells which do not express APS. APS-mediated recruitment of c-Cbl to the insulin receptor led to rapid ubiquitination of the insulin receptor beta-subunit in CHO. T-APS but not in parental CHO.T cells. These results suggest that the function of APS is to facilitate coupling of the insulin receptor to c-Cbl in order to catalyse the ubiquitination of the receptor and initiation of internalisation or degradation.

Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study

Exposure to high concentrations of radon progeny (radon) produces lung cancer in both underground miners and experimentally exposed laboratory animals. To determine the risk posed by residential radon exposure, the authors performed a population-based, case-control epidemiologic study in Iowa from 1993 to 1997. Subjects were female Iowa residents who had occupied their current home for at least 20 years. A total of 413 lung cancer cases and 614 age-frequency-matched controls were included in the final analysis. Excess odds were calculated per 11 working-level months for exposures that occurred 5-19 years (WLM(5-19)) prior to diagnosis for cases or prior to time of interview for controls. Eleven WLM(5-19) is approximately equal to an average residential radon exposure of 4 pCl/liter (148 Bq/m3) during this period. After adjustment for age, smoking, and education, the authors found excess odds of 0.50 (95% confidence interval: 0.004, 1.81) and 0.83 (95% percent confidence interval: 0.11, 3.34) using categorical radon exposure estimates for all cases and for live cases, respectively. Slightly lower excess odds of 0.24 (95 percent confidence interval: -0.05, 0.92) and 0.49 (95 percent confidence interval: 0.03, 1.84) per 11 WLM(5-19) were noted for continuous radon exposure estimates for all subjects and live subjects only. The observed risk estimates suggest that cumulative ambient radon exposure presents an important environmental health hazard.

A direct brain interface based on event-related potentials

Cross-correlation between a trigger-averaged event-related potential (ERP) template and continuous electrocorticogram was used to detect movement-related ERP's. The accuracy of ERP detection for the five best subjects (of 17 studied), had hit percentages >90% and false positive percentages <10%. These cases were considered appropriate for operation of a direct brain interface.

Analysis of apoptosis of lymphoid cells in fish exposed to immunotoxic compounds

BACKGROUND

Chemical induction of apoptosis in cells is believed to contribute to toxicity. Techniques for measuring apoptosis have increased in both sensitivity and number and in many cases can be readily extended to nontraditional research species. A comparison of established assays for measuring apoptosis of lymphoid cells has thus far not been performed in the fish and thus would be efficacious in assessing immunotoxicity.

METHODS

The present study evaluated chemical-induced immune cell apoptosis in fish (tilapia, Oreochromis niloticus) exposed to two known immunotoxic chemicals, azathioprine and T-2 toxin. Cytocentrifugation and light microscopy of leukocyte-enriched cell samples from the pronephros (i.e., the fish primary hematopoietic compartment) demonstrated chemical-related increases in apoptotic bodies. This observation was examined further with the ApoAlert Annexin V Apoptosis kit and two DNA-binding dyes employed for detecting apoptosis, 7-aminoactinomycin D (7-AAD) and propidium iodide (PI).

RESULTS

The apoptotic probes confirmed the microscopic observations of increased apoptosis in the chemical-exposed fish. The ApoAlerttrade mark annexin V and 7-AAD assays, which discriminate early and late apoptosis/necrosis, compared well in identifying apoptotic populations. PI staining in Vindelov's solution was unable to detect early apoptosis.

CONCLUSIONS

The present data suggest that apoptotic immune cells may be a useful marker for certain immunotoxicant exposures in fish. These findings agree with those of previous reports that fish may respond immunologically in a manner similar to mammals after immunotoxicant challenge.

Validity of a modified version of the Marks Asthma Quality of Life Questionnaire

To produce a scale useful for individual clinical decision making, the Marks Asthma Quality of Life Questionnaire (AQLQ-M) was modified to a 22-item scale using a 7-point Likert response scale, and the validity of the new instrument was assessed. Adult asthma subjects with moderate to severe disease, recruited from two hospitals in Adelaide, Australia, were surveyed at baseline (n = 293), and at 3-month follow-up (n = 234). Cronbach's alpha for the Total scale of the modified AQLQ-M (MAQLQ-M) was 0.97 and all subscale values exceeded 0.90. Test-retest reliability values for all scales were between 0.88 and 0.93. All correlations between disease reference measures were statistically significant to at least the p < 0.01 level. Stronger associations were seen with symptom and self-rating scales than for lung function, medication usage, and health service utilization measures of outcome. The MAQLQ-M showed good discriminative ability for all asthma symptom categories and for different FEV1 values. Moderate, statistically significant associations were seen between changes in MAQLQ-M scores and clinical measures. Higher baseline MAQLQ-M scores were associated with lower risks over 12 months for hospital admissions (odds ratio, OR = 0.58) and repeated emergency department visits (OR = 0.47). The MAQLQ-M is a highly valid measure of asthma-related quality of life.

A 5-year prospective study of Astra single tooth implants

AIM

To evaluate the AstraTech Implant ST (Molndal, Sweden) for single tooth replacement clinically and radiographically after 5 years in function.

SUBJECTS AND METHOD

Fifteen patients (age range 16 to 48) with missing maxillary anterior teeth (6 central incisors, 8 laterals, 1 bicuspid) had four 13 mm and eleven 15 mm single tooth implants provided. All patients were seen at 4- to 6-monthly intervals for oral hygiene maintenance. Periapical radiographs using Rinn holders and a long cone technique were taken at the crown insertion and after 1 year, 3 and 5 years.

RESULTS

No implant losses were observed in 14 of the 15 patients available for evaluation. No abutment screw loosening or soft tissue problems were observed. At crown insertion the mean bone level was 0.46 +/- 0.55 to 0.48 +/- 0.56 mm apical to the top of the implant neck and there were no statistically significant changes in the radiographic bone level over the 5 years of the study (0.36 +/- 0.37 to 0.43 +/- 0.46 mm at year 5). One crown was recemented after 18 months in function and 1 crown was replaced because of a fracture to the porcelain incisal edge.

CONCLUSION

The Astra Tech Implants ST were highly successful in single tooth replacement and bone levels during 5 years of function were stable.

Ictal spiking patterns recorded from temporal depth electrodes predict good outcome after anterior temporal lobectomy

PURPOSE

Investigators have shown that the presence of ictal spiking (IS) recorded from temporal depth electrodes is associated with mesial temporal sclerosis (MTS). We investigated the relation of IS to seizure control and pathology after anterior temporal lobectomy (ATL).

METHODS

All patients undergoing intracranial ictal monitoring from a single institution since 1989 were identified. Those who did not undergo ATL or had postoperative follow-up of <1 year were excluded. All received at a minimum bilateral temporal depth electrodes. Ictal recordings were reviewed for the presence of IS, and the proportion of seizures with IS was determined for each patient. Outcome was determined by using Engel's classification. Surgical specimens were reviewed for pathology. Statistics used were chi2, Fisher exact test, and Wilcoxon rank sum.

RESULTS

Forty patients with 571 seizures were reviewed. In 292 seizures from 32 patients, IS was seen. Outcomes were 24 class I (22 with IS), five class II (four with IS), three class III (one with IS), seven class IV (four with IS), and one lost to follow-up (with IS). Pathologic review revealed 25 with MTS, 22 of whom had IS. The presence of IS was associated with class I outcomes (p = 0.04), but not MTS (p = 0.06). Patients with class I outcomes had a significantly greater proportion of seizures with IS (mean, 0.58 +/- 0.3) compared with other outcomes (mean, 0.30 +/- 0.3, p = 0.02).

CONCLUSIONS

The presence of IS and higher proportion of seizures with IS correlated with good seizure outcome after ATL. This information may be used in preoperative counseling.