Fluoroquinolone Susceptibility among Mycobacterium tuberculosis Isolates from the United States and Canada

BACKGROUND

There is increasing interest in the possible role of new fluoroquinolone antibiotics for treatment of tuberculosis, but widespread use of fluoroquinolones for treatment of other bacterial infections may select for resistant strains of Mycobacterium tuberculosis.

METHODS

We evaluated fluoroquinolone susceptibility using the proportion method (critical ciprofloxacin concentration for susceptibility testing, 2.0 mu g/mL) in isolates obtained from patients enrolled in Tuberculosis Trial Consortium clinical trials during the period of 1995-2001 and in a referral sample of isolates sent to the Centers for Disease Control and Prevention (Atlanta, GA) during the period of 1996-2000 for additional testing, often because of drug resistance.

RESULTS

Of the 1373 isolates from the clinical trials, 1324 (96%) were susceptible to isoniazid and rifampin; 2 (0.15%) of these isolates were also resistant to ciprofloxacin. Of the 1852 isolates from the referral sample, 603 (32.6%) were resistant to isoniazid and rifampin (i.e., multidrug resistant), 849 (45.7%) were resistant to >or=1 first-line drug but were not resistant to both isoniazid and rifampin, and 400 (21.6%) were susceptible to all first-line agents. Ciprofloxacin resistance was found in 33 (1.8%) of the referral-sample isolates. Most ciprofloxacin-resistant isolates (25 [75.8%]) were resistant to isoniazid and rifampin.

CONCLUSIONS

Despite widespread use of fluoroquinolones for treatment of common bacterial infections, resistance among clinical isolates of M. tuberculosis in the United States and Canada remains rare, occurring primarily among multidrug-resistant strains.

Memory impairment, but not cerebrovascular disease, predicts progression of MCI to dementia

BACKGROUND

Mild cognitive impairment (MCI) is widely viewed as the transition phase between normal aging and Alzheimer disease (AD). Given that MCI can also result from cerebrovascular disease (CVD), the authors used clinical, MRI, and cognitive measures of AD and CVD to test the hypothesis that CVD increases the likelihood of progression from MCI to dementia within 3 years.

OBJECTIVE

To examine the impact of CVD on progression of MCI to dementia.

METHODS

Fifty-two consecutive patients with MCI (71% men) including many with symptomatic CVD were longitudinally evaluated for 3.1 +/- 1.3 years. MCI was defined as a Clinical Dementia Rating Scale (CDR) score of 0.5. Dementia was defined as progression to a CDR score of > or =1.0.

RESULTS

Forty-four percent of the MCI patients had MRI infarcts, 50% of which were symptomatic. Thirty-three percent of patients progressed to dementia, and 37.8% of these had MRI infarcts. Clinically probable or possible AD was diagnosed in approximately 82% of converters. Of the clinical and MRI measures, only hippocampal volume was associated with increased risk to progression (hazard ratio [HR] = 0.31 [95% CI 0.1 to 0.92], p = 0.03). When neuropsychological measures were included in the analysis, memory (HR = 0.90 [95% CI 0.84 to 0.96], p = 0.002) and executive function (HR = 0.96 [95% CI 0.92 to 1.0], p = 0.045) were associated with increased risk of dementia progression, whereas APOE genotype, cerebrovascular risk factors, clinical stroke, presence or absence of lacunes, and extent of white matter hyperintensities did not predict progression.

CONCLUSION

Within a heterogenous group of MCI patients, including many with clinically significant CVD, baseline memory and executive performance significantly predicted likelihood to develop dementia.

Behavioral disorders in the frontal and temporal variants of frontotemporal dementia

OBJECTIVE

To compare the behavioral features and to investigate the neuroanatomic correlates of behavioral dysfunction in anatomically defined temporal and frontal variants of frontotemporal dementia (tvFTD and fvFTD).

METHODS

Volumetric measurements of the frontal, anterior temporal, ventromedial frontal cortical (VMFC), and amygdala regions were made in 51 patients with FTD and 20 normal control subjects, as well as 22 patients with Alzheimer disease (AD) who were used as dementia controls. FTD patients were classified as fvFTD or tvFTD based on the relative degree of frontal and anterior temporal volume loss compared with controls. Behavioral symptoms, cerebral volumes, and the relationship between them were examined across groups.

RESULTS

Both variants of FTD showed significant increases in rates of elation, disinhibition, and aberrant motor behavior compared with AD. The fvFTD group also showed more anxiety, apathy, and eating disorders, and tvFTD showed a higher prevalence of sleep disturbances than AD. The only behaviors that differed significantly between fvFTD and tvFTD were apathy, greater in fvFTD, and sleep disorders, more frequent in tvFTD. FvFTD was associated with greater frontal atrophy and tvFTD was associated with more temporal and amygdala atrophy compared with AD, but both groups showed significant atrophy in the VMFC compared with AD, which was not associated with VMFC atrophy. In FTD, the presence of many of the behavioral disorders was associated with decreased volume in right-hemispheric regions.

CONCLUSION

FvFTD and tvFTD show many similarities in behavior, which appear to be associated with damage to right frontal and temporal structures.

Pharmacokinetics of Rifapentine at 600, 900, and 1,200 mg during Once-Weekly Tuberculosis Therapy

The pharmacokinetics of rifapentine at 600, 900, and 1,200 mg were studied during once-weekly continuation phase therapy in 35 patients with tuberculosis. Mean area under the plasma concentration-time curve (AUC(0-infinity)) increased significantly with dose (rifapentine AUC(0- infinity): 296, 410, and 477 microg.hour/ml at 600, 900, and 1,200 mg, respectively; p = 0.02 by linear regression). In multivariate stepwise regression analyses, AUC(0-infinity) values for rifapentine and the active 25-desacetyl metabolite were associated with drug dose and plasma albumin concentration, and were lower among men and among white individuals. Fifty-four percent of patients had total (free and protein-bound) plasma concentrations of rifapentine and of desacetyl rifapentine detected for more than 36 hours after clearance of concurrently administered isoniazid. Serious adverse effects of therapy in these study patients were infrequent (1 of 35 cases; 3%) and not linked with higher rifapentine AUC(0-infinity) or peak concentration. The present pharmacokinetic study supports further trials to determine the optimal rifapentine dose for treatment of tuberculosis.

Deformation tensor morphometry of semantic dementia with quantitative validation

High-resolution structural MRI scans of 20 subjects diagnosed with semantic dementia were compared against scans of 20 cognitively normal control subjects using whole brain deformation tensor morphometry to study spatially consistent differences in local anatomical size. A fine lattice free-form volume registration algorithm was used to estimate a continuous mapping from a reference MRI to each individual subject MRI. The Jacobian of these transformations at each voxel were used to quantitatively map relative anatomical size in each individual brain. Intensity consistent filtering was applied to the determinant of these Jacobians. A careful validation using manually traced gyral anatomy was carried out and used to select an optimal deformation tensor filter scale at which to examine the anatomical size maps. General linear modeling at each voxel was used to decompose the influence of age and head size from the primary diagnosis. Maps of the T statistic of the diagnosis across the 40 subjects highlighted significant (P < 0.01 Bonferroni corrected) focal tissue contraction effects related to dementia diagnosis in the left temporal pole extending into the hippocampus, occipitotemporal gyrus and parahippocampal gyrus. Some evidence of greater focal contraction in gray over white matter was also apparent. Contraction effects were also seen, but with reduced significance in the right temporal anatomy, focused toward the temporal pole and hippocampal regions. Additional lower significance findings (P < 0.05 permutation corrected) were detected in the left superior frontal gyrus, left orbital gyrus and left parietal lobe.

Favorable early results of gastric banding for morbid obesity: the American experience

BACKGROUND

In 2001 a new device for surgical weight loss was approved by the Food and Drug Administration (Lap-Band, Inamed Health). We describe initial results of laparoscopic gastric banding for morbid obesity in two American academic centers.

METHODS

Prospective data was collected on consecutive morbidly obese patients undergoing laparoscopic adjustable gastric banding, and evaluated retrospectively.

RESULTS

Four hundred forty-five consecutive patients underwent Lap-Band from May 2001 through December 2002. The 103 men and 341 women had an average age of 42.1 years (range 17-72 years) and an average body mass index (BMI) of 49.6 kg/m2 (range 35.2-92.2 kg/m2). One operation required conversion to laparotomy due to bleeding; the rest were completed laparoscopically. Mean length of stay was 1.1 days (range 1-10 days). There was one death. Additional complications included band slippage in 14 patients (3.1%), gastric obstruction without slip in 12 (2.7%), port migration in 2 (0.4%), tubing disconnections in 3 (0.7%), and port infection in 5 (1.1%). Two bands (0.4%) were removed due to intraabdominal abscess 2 months after placement. There was one band erosion (0.2%) and no clinically significant esophageal dilation. Ninety-nine patients have 1-year follow-up and have lost an average of 44.3% excess body weight.

CONCLUSION

Laparoscopic gastric banding has much to offer the morbidly obese. We present data showing weight loss rivaling gastric bypass and acceptably low complications. These results parallel success with this device outside America.

Assessment of mobility, activities and pain in different subtypes of epidermolysis bullosa

A standardized questionnaire was used to assess mobility, activity and pain in 140 randomly chosen children, who were representative of all major types and subtypes of inherited epidermolysis bullosa (EB). Pain status in these children was compared with 374 randomly selected adults with EB. The level of independence for each of six activities of daily living (ADL) (toileting; feeding; bathing; dressing; grooming; walking) was assessed in these EB children using conventional criteria for scoring. Whereas more than 90% of all EB simplex (EBS) and dominant dystrophic EB (DDEB) children were totally independent for each function (excluding walking), the frequency of similarly totally independent patients with junctional EB (JEB) and recessive dystrophic EB (RDEB) ranged from only 39% to 73%. No DDEB children and only 2% of EBS patients were totally dependent in their individual ADL, in comparison to 8-27% of JEB and 2-27% of RDEB children. Totally independent walking was reported in only 31%, 31%, 67%, and 24% of EBS, JEB, DDEB, and RDEB children, respectively. A daily level of EB-related pain was assessed in children by their parents using a linear scale of 0 (no pain) to 10 (unbearable pain). Whereas 14-19% of all children with EBS, JEB, and DDEB were graded with pain levels of more than 5, 32% of all RDEB children reportedly suffered this much pain. Increased frequencies of pain with scores more than 5 were most often noted in those patients having more clinically extensive or severe EB subtypes. These included JEB-Herlitz (20% vs. 14% in JEB-non-Herlitz) and RDEB-Hallopeau-Siemens (47% vs. 20% in all other RDEB subtypes). Only 5% of all RDEB children reportedly were pain-free, compared to 12-14% of those with EBS, JEB, and DDEB. Collectively, these data provide the first report of the specific impact different forms of EB have on daily living and coping with this genodermatosis.

Prevalence of the lpfO113 gene cluster among Escherichia coli O157 isolates from different sources

Domestic farm animals represent an important reservoir of infection for Shiga toxin-producing Escherichia coli (STEC). Nevertheless the bacterial factors required to colonise these hosts are poorly defined. In this study, the prevalence of a recently described fimbrial gene cluster, lpfO113, among human and animal isolates of STEC was investigated. lpfO113 has been shown to play a role in the adherence of STEC O113:H21 to epithelial cells. Here the presence of the lpfAO113 gene (predicted to encode a major fimbrial subunit) was examined by PCR in E. coli of serogroups O157 and O26 isolated from pigs (n=38), cattle (n=10), and humans (n=9). In addition, we tested for several other genetic virulence markers including Shiga toxin (stx), intimin (eae), the translocated intimin receptor (tir), EHEC-hemolysin (ehx) and F18 fimbriae (fedA). Overall 45 of the 57 strains (79%) possessed the lpfAO113 gene as determined by the presence of a 573 bp PCR product. Moreover, there was a close correlation between the presence of the lpfAO113 marker and the absence of the eae gene. lpfAO113 was found in all of pig isolates, suggesting a possible role in colonisation of the porcine host. In addition, several E. coli strains isolated from pigs had two fimbrial gene markers, fedA and lpfAO113. lpfAO113 was not present in strains of E. coli O157:H7 as described previously. Overall these results show that lpfAO113 is widely distributed among eae-negative E. coli isolates and thus may represent an important adherence factor in this group of pathogens.

Accurate template-based correction of brain MRI intensity distortion with application to dementia and aging

This paper examines an alternative approach to separating magnetic resonance imaging (MRI) intensity inhomogeneity from underlying tissue-intensity structure using a direct template-based paradigm. This permits the explicit spatial modeling of subtle intensity variations present in normal anatomy which may confound common retrospective correction techniques using criteria derived from a global intensity model. A fine-scale entropy driven spatial normalisation procedure is employed to map intensity distorted MR images to a tissue reference template. This allows a direct estimation of the relative bias field between template and subject MR images, from the ratio of their low-pass filtered intensity values. A tissue template for an aging individual is constructed and used to correct distortion in a set of data acquired as part of a study on dementia. A careful validation based on manual segmentation and correction of nine datasets with a range of anatomies and distortion levels is carried out. This reveals a consistent improvement in the removal of global intensity variation in terms of the agreement with a global manual bias estimate, and in the reduction in the coefficient of intensity variation in manually delineated regions of white matter.

Maintenance of inspiratory muscle training in COPD patients: one year follow-up

In most chronic obstructive pulmonary disease (COPD) patients, dyspnoea and functional exercise capacity may improve as a result of inspiratory muscle training (IMT). However, the long-term benefits of IMT have been investigated to a much lesser extent. The present study investigated the short-term and long-term benefits of IMT on inspiratory muscle performance (strength and endurance), exercise capacity and the perception of dyspnoea. Thirty-eight patients with significant COPD had 3 months of basic IMT and were then randomised into a group that received maintenance IMT for the next year, and a group that got training with very low load. Following the basic training there was a statistically significant increase in inspiratory muscle performance, 6-min walk test (6MWT), and a decrease in the dyspnoea. During the second stage of the study, the training group continued to maintain the improvement in all parameters, while there was already deterioration in the inspiratory muscle performance, exercise capacity and dyspnoea in the low intensity group during the 6-12 month period. The present study concludes that, in patients with significant chronic obstructive pulmonary disease, inspiratory muscle training results in improvement in performance, exercise capacity and in the sensation of dyspnoea. The benefits of 12-weeks of inspiratory muscle training decline gradually over 1 yr of follow-up if maintenance training is not performed.

An intensity consistent filtering approach to the analysis of deformation tensor derived maps of brain shape

Deformation tensor morphometry makes use of the derivatives of spatial transformations between anatomies, to provide highly localized volumetric maps of relative anatomical size. The analysis of such maps, however, has the challenge of describing the data in a way that allows the spatial scale and extent of the local shape properties to match those induced by the disease process being studied. This study examines an approach to the spatial filtering of transformation Jacobian maps created in multisubject studies of brain anatomy, which constrains the filter neighborhood within common structural boundaries present in the spatially normalized image data. The filtering incorporates information derived from the spatial normalization process, using a statistical framework to introduce a measure of uncertainty in local regional intensity correspondence following spatial normalisation. The proposed filtering approach is compared to the use of spatially invariant Gaussian filtering in the analysis of Jacobian determinant maps of brain shape and shape change in Alzheimer's disease and normal aging. Results show significantly improved delineation of fine scale patterns of shape difference (in cross-sectional studies) and shape change (from multiple serial magnetic resonance imaging studies).

Food additives used in meat processing according to the Polish and European Union legislation

This paper presents the legal regulations related to the use of food additives in meat production in Poland and the European Union. The Polish legal definition of food additives is given as well as the classification of permitted food additives added to food and stimulants by their technological function. In addition, a definition of processing aids in the food industry is included. It shows that Polish legislation includes food additives used to ensure or improve food nutritional value, whereas in the EU legislation, these substances are not included in the list of food additives. Moreover, the Council Directives include food additive specific purity criteria, whereas the Polish regulations do not mention the legal regulations of this issue in practice. The European Union use mechanisms and procedures for the introduction of new food additives into internal markets as well as controlling the circulation of additives. The Polish legislation in practice, however, does not determine approval or methods for the introduction of new food additives to the market. Legal regulations on the monitoring of food additives no exist.

Correlation of statin-increased platelet APP ratios and reduced blood lipids in AD patients

Platelets, like neurons, contain 120- to 130- and 110-kd amyloid precursor proteins (APPs). Their ratio is reduced in AD, further reductions correlating with reduced Mini-Mental Status Examination scores [r(11) = 0.69, p < 0.05]. As statins alter APP processing, platelet APPs were analyzed in patients with AD given anticholesterol drugs for 6 weeks. APP ratios increased [t(37) = -3.888, p = 0.0004], proportionally with reduced cholesterol [r(36) = -0.45, p = 0.005]. Longer trials may reveal slowed cognitive loss, validating this index.

Low isoniazid concentrations and outcome of tuberculosis treatment with once-weekly isoniazid and rifapentine

To understand why once-weekly isoniazid/rifapentine therapy for tuberculosis was less effective than twice-weekly isoniazid/rifampin, we studied human immunodeficiency virus-seronegative patients with either failure (n = 4), relapse (n = 35), or cure (n = 94), recruited from a comparative treatment trial. In multivariate analyses that were adjusted for severity of disease, low plasma concentrations of isoniazid were associated with failure/relapse with once-weekly isoniazid/rifapentine (median isoniazid area under the concentration-time curve for 12 hours after the dose [AUC(0-12)] was 36 microg x hour/ml in failure/relapse versus 56 microg x hour/ml in control cases p = 0.005), but not with twice-weekly isoniazid/rifampin. Furthermore, two patients who relapsed with Mycobacterium tuberculosis monoresistant to rifamycin had very low concentrations of isoniazid. Finally, isoniazid acetylator status determined by N-acetyltransferase type 2 genotype was associated with outcome with once-weekly isoniazid/rifapentine (p = 0.03) but not twice-weekly isoniazid/rifampin. No rifamycin pharmacokinetic parameter was consistently and significantly associated with outcome (p > 0.10). Because low isoniazid concentrations were associated with failure/relapse, a drug with consistently greater area under the concentration-time curve than isoniazid may be needed to achieve highly active once-weekly therapy with rifapentine.

Rifapentine and isoniazid once a week versus rifampicin and isoniazid twice a week for treatment of drug-susceptible pulmonary tuberculosis in HIV-negative patients: a randomised clinical trial

BACKGROUND

Rifapentine has a long half-life in serum, which suggests a possible treatment once a week for tuberculosis. We aimed to compare rifapentine and isoniazid once a week with rifampicin and isoniazid twice a week.

METHODS

We did a randomised, multicentre, open-label trial in the USA and Canada of HIV-negative people with drug-susceptible pulmonary tuberculosis who had completed 2 months of a 6-month treatment regimen. We randomly allocated patients directly observed treatment with either 600 mg rifapentine plus 900 mg isoniazid once a week or 600 mg rifampicin plus 900 mg isoniazid twice a week. Primary outcome was failure/relapse. Analysis was by intention to treat.

FINDINGS

1004 patients were enrolled (502 per treatment group). 928 successfully completed treatment, and 803 completed the 2-year 4-month study. Crude rates of failure/relapse were 46/502 (9.2%) in those on rifapentine once a week, and 28/502 (5.6%) in those given rifampicin twice a week (relative risk 1.64, 95% CI 1.04-2.58, p=0.04). By proportional hazards regression, five characteristics were independently associated with increased risk of failure/relapse: sputum culture positive at 2 months (hazard ratio 2.8, 95% CI 1.7-4.6); cavitation on chest radiography (3.0, 1.6-5.9); being underweight (3.0, 1.8-4.9); bilateral pulmonary involvement (1.8, 1.0-3.1); and being a non-Hispanic white person (1.8, 1.1-3.0). Adjustment for imbalances in 2-month culture and cavitation diminished the association of treatment group with outcome (1.34; 0.83-2.18; p=0.23). Of participants without cavitation, rates of failure/relapse were 6/210 (2.9%) in the once a week group and 6/241 (2.5%) in the twice a week group (relative risk 1.15; 95% CI 0.38-3.50; p=0.81). Rates of adverse events and death were similar in the two treatment groups.

INTERPRETATION

Rifapentine once a week is safe and effective for treatment of pulmonary tuberculosis in HIV-negative people without cavitation on chest radiography. Clinical, radiographic, and microbiological data help to identify patients with tuberculosis who are at increased risk of failure or relapse when treated with either regimen.

HLA class I and class II polymorphism in the population of Rijeka, Croatia

The aim of the study was to examine frequencies of HLA-A, -B, -DR antigens and haplotypes in population of Rijeka and to compare them with general Croatian and European populations. The subjects were 117 unrelated healthy blood donors. The antigens with the highest frequencies were: A2 (27.2%), A9 (16.3%), B5 (14.8%), B12 (11.8%), B18 (11.8%), DR5 (21.6%) and DR6 (13.8%). Comparison of HLA antigens frequencies has shown statistically significant difference in 1 antigen with Croatian population and in 8 antigens with European population. The HLA haplotypes with high frequencies included HLA-A2, B5 (6.84%), HLA-A2, B12 (6.84%), HLA-A2, B18 (6.84%), HLA-B12, DR2 (9.78%) and HLA-B18, DR5 (6.84%). The antigen B5 showed strongest association with DR5 (6.41%; LD = 1.30) as in general Croatian and in some European populations. The results have shown great diversity of HLA haplotypes in Rijeka population which can be the result of admixture with neighborhood immigrating populations during the history.

Patterns of brain atrophy in frontotemporal dementia and semantic dementia

OBJECTIVE

To identify and compare the patterns of cerebral atrophy associated with two clinical variants of frontotemporal lobar degeneration (FTLD): frontotemporal dementia (FTD) and semantic dementia (SemD).

METHODS

Twenty patients with FTLD were classified as having FTD (N = 8) or SemD (N = 12) based on current clinical criteria. Both groups showed a similar spectrum of behavioral abnormalities, as indicated by the neuropsychiatric inventory. T1-weighted MRI was obtained for each patient and 20 control subjects. The regions of focal gray matter tissue loss associated with both FTD and SemD, as well as those differing between the two groups were examined using voxel-based morphometry.

RESULTS

Regions of significant atrophy seen in both groups were located in the ventromedial frontal cortex, the posterior orbital frontal regions bilaterally, the insula bilaterally, and the left anterior cingulate cortex. The FTD, but not the SemD, group showed atrophy in the right dorsolateral frontal cortex and the left premotor cortex. The SemD, but not the FTD, group showed tissue loss in the anterior temporal cortex and the amygdala/anterior hippocampal region bilaterally.

CONCLUSIONS

Although FTD and SemD are associated with different overall patterns of brain atrophy, regions of gray matter tissue loss in the orbital frontal, insular, and anterior cingulate regions are present in both groups. The authors suggest that pathology in the areas of atrophy associated with both FTD and SemD may underlie some the behavioral symptoms seen in the two disorders.

E-mail versus conventional postal mail survey of geriatric chiefs

PURPOSE

This study compared the response time, response rate, and cost of two types of survey administration techniques: e-mail/web-based versus conventional postal mail. The main aim of the survey was to collect descriptive information on the existence of Acute Care for Elders units and their characteristics by surveying geriatric division chiefs.

DESIGN AND METHODS

Two randomized cohorts of geriatric division chiefs were formed to receive a survey either by electronic mail (n = 57) or by conventional postal mail (n = 57). If there was no response to the initial mailing, two follow-up mailings were sent to both groups using the original modality; a third follow-up was performed using the alternative modality. For each group, response rate and response time were calculated. The average total cost was computed and compared across two groups.

RESULTS

The aggregate response rate was 58% (n = 31) for the e-mail group versus 77% (n = 44) for the postal mail group. The overall average response time was shorter in the e-mail group, 18 days compared with 33 days for the conventional postal mailing group. The cost comparison showed that average cost was $7.70 for the e-mail group, compared to $10.50 per response for the conventional mail group.

IMPLICATIONS

It appears that although the web-based technology is gaining popularity and leads to lower cost per response, the conventional postal method of surveying continues to deliver a better response rate among the geriatric medicine division chiefs. The web-based approach holds promise given its lower costs and acceptable response rate combined with the shorter response time.

Tissue slices revisited: evaluation and development of a short-term incubation for integrated drug metabolism

This work details the development of a model for the rapid evaluation of drug metabolism in an integrated fashion using in situ architecture of the liver. A Krumdieck tissue slicer was used to generate slices from 10-mm cores of rat liver (approximately 250-microm thick). Initial unsuccessful efforts with 6-well plate-based incubation were overcome with the use of a dynamic (rotating) incubation in 23-ml liquid scintillation vials containing titanium mesh supports for the slice. Incubation of 1 slice/5 ml of a Krebs-Henseleit solution buffered with HEPES showed a <2% increase over the initial 25% release of lactate dehydrogenase over 2 h of incubation at 37 degrees C under ambient oxygen conditions. Coupled O-dealkylase and conjugative metabolism of alkoxycoumarin derivatives was shown to be linear for both 7-methoxy- and 7-ethoxycoumarin (100 microM) with a low amount of nonconjugated 7-hydroxycoumarin (7-HC) at all time points. Metabolic profiles for 7-methoxy- and 7-ethoxycoumarin were compared between slice and microsomal incubations generated from the same tissue. The use of 7-HC as a primary substrate not only provided an assessment of the capacity-based differences in oxidative versus conjugative metabolism but also capacity-based differences in glucuronidation and sulfation. These studies underscore the physiological fact that phase I metabolism has a lower capacity for substrate metabolism than phase II metabolism. Additionally, this technique provides a model for examination of pharmacodynamic and pharmacokinetic influences in the context of maintenance of the in situ architecture of the liver.

Impact of a hospital-based antimicrobial management program on clinical and economic outcomes

Inappropriate use of antimicrobial agents results in unnecessary exposure to medication, persistent or progressive infection, emergence of resistance, and increased costs. We implemented a program to control use of restricted agents while improving care. This study compared 2 major mechanisms for improving use of antimicrobial agents: (1) recommendations made by the Antimicrobial Management Team (AMT), which included a clinical pharmacist backed up by a physician from the Division of Infectious Diseases (ID), and (2) recommendations made by ID fellows. Outcome measures included appropriateness of recommendations, cure rate, number of treatment failures, and cost of care, which were assessed for 180 patients. The AMT outperformed the ID fellows in all outcomes examined by the study (including appropriateness [87% vs. 47%; P<.001], cure rate [64% vs. 42%; P=.007], and treatment failures [15% vs. 28%; P=.03]), although the differences in economic outcomes between cases managed by the AMT and those managed by the ID fellows were not statistically significant. In an academic setting with a restricted formulary, the AMT demonstrated better antimicrobial prescribing than ID fellows.

Frontal lobe hypometabolism predicts cognitive decline in patients with lacunar infarcts

BACKGROUND

A proportion of patients with subcortical lacunes will suffer progressive cognitive dysfunction, but the basis for this decline is controversial and little is known about predicting cognitive decline in these patients. Studies of Alzheimer disease have shown that imaging measures of temporal and parietal metabolism and blood flow predict disease course.

OBJECTIVE

To determine whether regional cerebral glucose metabolism predicts cognitive decline by testing 2 opposing hypotheses: (1) temporoparietal activity predicts decline (based on the idea that concomitant Alzheimer disease causes decline) vs (2) frontal hypometabolism predicts decline (based on evidence that subcortical frontal circuits are especially vulnerable to small vessel ischemia).

DESIGN

Prospective cohort study.

SETTING

University outpatient dementia center.

PATIENTS

A convenience sample of 26 patients with radiologically defined lacunes and baseline cognitive function ranging from normal to moderately demented.

MAIN OUTCOME MEASURES

Regional cerebral metabolism was quantitated in the form of atrophy-corrected positron emission tomographic activity ratios in cortical regions that were defined a priori. Patients were followed up at a mean of 1.8 years, and the dependent variable was rate of change in the Mini-Mental State Examination score.

RESULTS

Bilateral and right hemisphere dorsolateral frontal metabolism significantly predicted cognitive decline, with right dorsolateral frontal metabolism explaining 19% of the variance. No other positron emission tomographic region was a significant predictor, nor were demographic variables or baseline Mini-Mental State Examination scores significant predictors.

CONCLUSION

Cognitive decline in patients with lacunes may result in part from progressive vascular compromise in subcortical frontal circuits.

Secure Internet video conferencing for assessing acute medical problems in a nursing facility

Although video-based teleconferencing is becoming more widespread in the medical profession, especially for scheduled consultations, applications for rapid assessment of acute medical problems are rare. Use of such a video system in a nursing facility may be especially beneficial, because physicians are often not immediately available to evaluate patients. We have assembled and tested a portable, wireless conferencing system to prepare for a randomized trial of the system s influence on resource utilization and satisfaction. The system includes a rolling cart with video conferencing hardware and software, a remotely controllable digital camera, light, wireless network, and battery. A semi-automated paging system informs physicians of patient s study status and indications for conferencing. Data transmission occurs wirelessly in the nursing home and then through Internet cables to the physician s home. This provides sufficient bandwidth to support quality motion images. IPsec secures communications. Despite human and technical challenges, this system is affordable and functional.

The survival characteristics of dense sickle cells

Sickle red blood cells (RBCs) become depleted of potassium, leading to dehydration and abnormally elevated cellular density. The increased sickling that results is important for both hemolysis and vasocclusion. In this study, sickle cells were subjected to high-speed centrifugation, and the bottom 15% were isolated. This procedure removed light cells and to a variable degree enriched cells that were denser than normal to produce a high-density-enriched (HDE) population of sickle cells. Autologous HDE cells from 3 subjects were labeled with biotin and re-infused. The following determinations were performed: (1) the survival and density changes of HDE cells; (2) the amount of fetal hemoglobin (HbF) in labeled cells after magnetic isolation; (3) the percentage of labeled F cells; (4) the percentage of labeled cells displaying external phosphatidylserine (PS). For patients with 3.5%, 4.5%, and 24% HbF in the HDE RBCs, the circulation half-time was 40, 80, and 180 hours, respectively. The percentage of HbF (measured in all 3 subjects) and of F cells (measured in 2 subjects) in labeled RBCs increased with time after re-infusion, indicating that HDE F cells have longer in vivo survival than HDE non-F cells. The percentage of PS(+), biotin-labeled HDE cells showed no consistent increase or decrease with time after re-infusion. These data provide evidence that HDE sickle cells, especially those that do not contain HbF, have a very short in vivo survival, and that the percentage of PS(+) cells in a re-infused HDE population does not change in a consistent manner as these cells age in the circulation.

The cumulative effect of long-acting bronchodilators, exercise, and inspiratory muscle training on the perception of dyspnea in patients with advanced COPD

BACKGROUND

Dyspnea is a common complaint during daily activities in patients with advanced COPD. The mechanisms underlying dyspnea and the appropriate treatment strategies to relieve it are still not totally understood. We hypothesized that the perception of dyspnea (POD) may be modified by the accumulative effect of bronchodilator therapy, exercise, and inspiratory muscle training (IMT).

METHODS

Spirometry, submaximal exercise performance, inspiratory muscle strength and endurance, and the POD were assessed before and following three consecutive 6-week periods of therapy with a long-acting bronchodilator (LABD), the LABD plus exercise, and the LABD plus exercise plus IMT in 30 patients with moderate-to-severe COPD.

RESULTS

There was a small, statistically insignificant, increase in FEV(1) in the study group (mean [+/- SEM] increase, 1.42+/-0.3 to 1.49+/-0.4 L) following the LABD therapy period, and no additional increase following the two other periods of therapy. There was a significant increase (p<0.05) in the 6-min walk distance following the therapy period with the LABD plus exercise (mean increase, 252+/-41 to 294+/-47 m) and an additional small increase following the therapy period with the LABD plus exercise plus IMT period (mean increase, 252+/-41 to 302+/-49 m). The decrease in the POD was small and statistically not significant following the therapy periods with the LABD and the LABD plus exercise. The major and statistically significant decrease in the POD was noted following the therapy period with the LABD plus exercise plus IMT.

CONCLUSIONS

In patients with moderate-to-severe COPD, following sequential periods of therapy with the LABD, the LABD plus exercise, and the LABD plus exercise plus IMT, there is a cumulative benefit in the POD. The most significant improvement was associated with IMT and not with the LABD and exercise training. The FEV(1) was moderately increased following the therapy period with the LABD, and the addition of exercise has most affected the 6-min walk distance.

Smoking and first acute myocardial infarction: age, mortality and smoking cessation rate

BACKGROUND

Cigarette smoking is a major contributor to the risk of acute myocardial infarction and the subsequent morbidity and mortality. Physicians can play an important role in smoking cessation among patients with AMI because of their frequent contact with the patient during the event.

OBJECTIVES

To study the prevalence of smoking, age, localization of coronary occlusion, mortality and rate of smoking cessation in consecutive patients who were diagnosed with a first AMI in our center in 1989-93.

METHODS

The study included 1,510 consecutive patients with first AMI: 973 men (512 smokers, 52.6%) and 537 women (215 smokers, 40%), whose mean age was 64.1 +/- 6.7 and 68.6 +/- 5.2 years respectively.

RESULTS

The median age at the first AMI in non-smoking and smoking men differed significantly (70.4 +/- 6.8 vs. 56.6 +/- 6.1 years, P < 0.001) while the difference in the women was smaller (70.4 +/- 6.9 vs. 66.8 +/- 7.2). The proportion of smokers/non-smokers among men was greater at a younger age and decreased proportionally with age. The overall mortality was 11.3% with a significant difference in mortality rate in the younger age groups between smokers and non-smokers (1% vs. 0% in the age group 31-40 years, P < 0.05, and 6.1% vs. 0.8% in the 41-50 year age group, P < 0.001). Only 62% of the smokers who survived the AMI declared that they had received anti-smoking advice from a physician during hospitalization. The cessation rate in this group was significantly higher than in smokers who had not been cautioned against smoking (56% vs. 18%).

CONCLUSIONS

Current smokers sustained their first AMI more than one decade earlier than non-smokers, and the younger smokers had a higher mortality rate. The majority of the smokers who received anti-smoking advice during their hospitalization for AMI quit smoking in the year following the acute event.

Factors associated with adherence to treatment regimens after lung transplantation

CONTEXT

The number of patients currently awaiting lung transplantation far exceeds the supply of available organs. Adherence to postoperative treatment regimens is essential for optimal posttransplant success.

OBJECTIVE

The present study was designed to examine the demographic and psychological factors associated with compliance in patients who have had lung transplants.

DESIGN

Eighteen women and 13 men participated in this study an average of 24 months after transplantation, completing a demographic form, a self-report compliance measure, a social support questionnaire, and the Multidimensional Health Locus of Control Scale. A significant other or family member and the posttransplant nurse coordinator also rated each subject's compliance with the posttransplant regimen.

RESULTS

Although patients rated themselves as being compliant with aspects of their self-care, on more subtle measures of compliance, their self-reported compliance was not as impressive. Patients who had had their transplants more recently appeared to be more compliant. Patients with cystic fibrosis used their spirometer more often than patients with other lung diseases. Family support was significantly correlated with self-reported compliance.

CONCLUSIONS

This study suggests that how patients are asked about adherence to treatment regimens influences how compliant they appear. The data also indicate that the longer after transplant, the less compliant the patient, and suggests the need for patient reeducation at some point after transplant. Longitudinal studies are needed to assess the degree to which compliance affects the number of rejection and febrile episodes as well as patient mortality after lung transplant.

Specific inspiratory muscle training in patients with mild asthma with high consumption of inhaled beta(2)-agonists

BACKGROUND

It has been known for many years that there are variations between asthmatic patients in terms of their perception of breathlessness during airway obstruction.

STUDY OBJECTIVE

To investigate the relationship between beta(2)-agonist consumption and the score of perception of dyspnea, in mild asthmatics, and the relationship between the effect of specific inspiratory muscle training (SIMT) on the score of perception of dyspnea and beta(2)-agonist consumption in "high perceivers."

METHODS

Daily beta(2)-agonist consumption was assessed during a 4-week run-in period in 82 patients with mild asthma. Patients with a mean beta(2)-agonist consumption of > 1 puff/d ("high consumers") then were randomized into two groups: one group of patients received SIMT for 3 months; the other group of patients was assigned as a control group and received sham training. Inspiratory muscle strength and perception of dyspnea were assessed before patients entered the study, following the 4-week run-in period, and after completing the training period.

RESULTS

Following the 4-week run-in period, 23 high-consumer patients (mean [+/- SEM] beta(2)-agonist consumption, 2.7 +/- 0.4 puffs/d) were detected. The mean Borg score during breathing against resistance was significantly higher (p < 0.05) in the patients with high beta(2)-agonist consumption than in the subjects with low mean beta(2)-agonist consumption. Following SIMT, the mean maximal inspiratory pressure increased significantly from 94.1 +/- 5.1 to 109.7 +/- 5.2 cm H(2)O (p < 0.005) in the training group. The increase in inspiratory muscle strength was associated with a statistically significant decrease in the mean Borg score during breathing against resistance (p < 0.05) as well as in the mean daily beta(2)-agonist consumption.

CONCLUSIONS

We have shown that patients with mild asthma, who have a high beta(2)-agonist consumption, have a higher perception of dyspnea than those with normal consumption. In addition, SIMT was associated with a decrease in perception of dyspnea and a decrease in beta(2)-agonist consumption.

The perception of dyspnoea in patients with asthma, before and following treatment with inhaled glucocorticosteroids

This study was designed in order to establish the perception of breathlessness during rest and while breathing against resistance, in patients with asthma, before and after 8 weeks of inhaled glucocorticoids (IGC) treatment and to compare these parameters in patients with and without improvement in FEV1. Sixty-seven asthmatic patients, with moderate asthma, attending the asthma clinic, and 20 normal subjects were studied. After a 2-week run-in period, in which the subjects were asked to use exclusively beta2-agonists as needed, the asthmatic patients were randomized to receive either treatment with IGC, 250 microg of fluticasone propionate (FP) twice a day, via a diskhaler (47 patients), or to receive placebo (20 patients) and to serve as a control group, for 8 weeks. Spirometry and measurements for the sensation of dyspnoea were performed before and at the end of the treatment period. The mean dyspnoea score during breathing against resistance was significantly lower (P<0.05) in the patients with asthma than in normal subjects, before entering the study. Following 8 weeks of inhaled FP, there was a significant improvement in the mean dyspnoea score during breathing against resistance in the asthmatics receiving IGCs but not in the control group (P<005). In the study group 32 patients had an improved FEV1 > 15% and 15 patients did not. There was a statistically significant difference in perception of dyspnoea (P<0.01), between the group of patients with a improved FEV1 and the group of patients that were under IGC treatment without improvement in their FEV1. There was also a difference in the mean beta2-agonists consumption between the two groups (P<0.01). Asthmatic patients have a significantly lower perception of dyspnoea compared to normal subjects. IGC treatment was associated with increased perception of dyspnoea. However, this improvement was noted only in patients with improved FEV1, while the patients without improvement remained with an equal degree of dyspnoea perception and beta2-agonists consumption.

An examination of bias in volunteer subject selection: findings from an in-depth child abuse study

Remarkably few reported studies tested the assumption that a research sample can be constructed which is representative of the population of interest. In order to investigate potential volunteer bias in abuse research, we utilized a database assembled for an NIMH funded study investigating the relationship among adolescent physical abuse, suicidal behavior, and psychopathology. Extensive information was available concerning the nonparticipant pool from which this sample was assembled, allowing for a comprehensive assessment of possible sample bias. The volunteer sample of 99 abused families who agreed to participate in our study was compared on a large number of variables with a random sample of 99 abused families who declined to participate. Comparisons of the two groups did not support the hypothesis that the non-participating families represented a more dysfunctional population. The two groups were far more similar to, than disparate from, each other.

Physically abused adolescents: behavior problems, functional impairment, and comparison of informants' reports

OBJECTIVE

This study, like earlier studies that focused on younger abused children, ascertained whether physically abused adolescents exhibited increased internalizing and externalizing behaviors. Relevance to pediatric practice is discussed.

DESIGN

A cross-sectional design was used to compare the behavior of physically abused adolescents and comparison adolescents using self-reports, parent reports, and teacher reports. The level of agreement among raters was also examined.

PARTICIPANTS

The subjects were 99 physically abused adolescents between the ages of 12 and 18 years, who were recruited from Child Protective Services. Comparison subjects were 99 community-recruited nonabused adolescents who were matched for age, gender, and income with the abused adolescents.

MEASURES

The behavior of the adolescents was assessed using the Child Behavior Checklist, and the comparable Youth Self-Report and Teacher Report Form, which are widely used measures of behavioral and emotional problems. The Child Global Assessment Scale was also used as a measure of functional impairment and of the need for mental health services.

RESULTS

Parents and teachers rated the problems of abused adolescents as significantly greater than the problems of nonabused adolescents on all checklist subscales. Abused adolescents reported significantly greater problems only on externalizing behavior subscales. In addition, based on interviewer ratings, physically abused adolescents exhibited significantly greater functional impairment.

CONCLUSIONS

Similar to previous research on abused children, physically abused adolescents exhibit externalizing and internalizing behavior problems and experience greater functional impairment. Parent, teacher, and adolescent reports of externalizing behaviors were similar, but physically abused adolescents reported fewer internalizing behaviors than did the other informants.

The response to inhaled and oral steroids in patients with stable chronic obstructive pulmonary disease

BACKGROUND

A significant minority of patients with COPD have favourable response to corticosteroid treatment. In addition, the benefit of corticosteroid treatment may be outweighed by the side-effects. Long-term administration of inhaled steroids is a safe means of treatment. However, only a few studies have addressed the role of inhaled steroids in patients with COPD, with conflicting results.

METHODS

Forty-four patients with stable COPD were defined as 'responders to bronchodilators' (increase in FEV1 > or = 20% following administration of beta 2-agonist) (group A), and 124 as 'non-responders to bronchodilators' (group B). All patients were randomized to receive a 6-week course of either a daily dose of 800 micrograms of inhaled budesonide or placebo, separated by 4 weeks when no medication was taken; were randomized again to receive a 6-week course of either 1600 micrograms day-1 of inhaled budesonide, or 800 micrograms day-1 of inhaled budesonide plus placebo; and were randomized once again to receive a 6-week course of either 40 mg day-1 of prednisone or placebo. All stages were performed in a double-blind cross-over design.

RESULTS

Following administration of 800 micrograms day-1 of inhaled budesonide, there was an increase in the mean FEV1 from 1.40 +/- 0.20 to 1.92 +/- 0.22 L (P < 0.001) and a significant decrease in inhaled beta 2 agonist consumption in group A. These changes remained almost stable during the increased dose of inhaled budesonide or during prednisone treatment. The mean FEV1 did not change during the placebo period, or in group B in either treatments.

CONCLUSIONS

Treatment with inhaled steroids improved spirometry data and inhaled beta 2-agonist consumption in about one-quarter of patients with stable COPD, and this rate increased to about three-quarters in patients who responded to beta 2-agonist inhalation. There was no additional benefit in using a higher dose of inhaled budesonide or prednisone.

Contrasting views of physicians and nurses about an inpatient computer-based provider order-entry system

OBJECTIVE

Many hospitals are investing in computer-based provider order-entry (POE) systems, and providers' evaluations have proved important for the success of the systems. The authors assessed how physicians and nurses viewed the effects of one modified commercial POE system on time spent patients, resource utilization, errors with orders, and overall quality of care.

DESIGN

Survey.

MEASUREMENTS

Opinions of 271 POE users on medicine wards of an urban teaching hospital: 96 medical house officers, 49 attending physicians, 19 clinical fellows with heavy inpatient loads, and 107 nurses.

RESULTS

Responses were received from 85 percent of the sample. Most physicians and nurses agreed that orders were executed faster under POE. About 30 percent of house officers and attendings or fellows, compared with 56 percent of nurses, reported improvement in overall quality of care with POE. Forty-four percent of house officers and 34 percent of attendings/fellows reported that their time with patients decreased, whereas 56 percent of nurses indicated that their time with patients increased (P < 0.001). Sixty percent of house officers and 41 percent of attendings/fellows indicated that order errors increased, whereas 69 percent of nurses indicated a decrease or no change in errors. Although most nurses reported no change in the frequency of ordering tests and medications with POE, 61 percent of house officers reported an increased frequency.

CONCLUSION

Physicians and nurses had markedly different views about effects of a POE system on patient care, highlighting the need to consider both perspectives when assessing the impact of POE. With this POE system, most nurses saw beneficial effects, whereas many physicians saw negative effects.

Characteristics of asthma in the elderly

Asthma occurs more frequently in the elderly than is usually appreciated and may, therefore, be underdiagnosed and undertreated. This study evaluated the relationship between asthma symptoms and the degree of airflow obstruction in elderly and young asthmatics. Fifteen young asthmatics (<65 yrs) (group A), 15 aged >65 yrs with onset of symptoms before 65 yrs (group B), and 15 aged >65 yrs with onset of symptoms after 65 yrs (group C), were studied. Patients used daily diary cards, during 2 weeks, to record inhaled beta2-agonist consumption and severity of asthma symptoms. Long-standing asthma was associated with a significantly lower forced expiratory volume in one second as compared with recent onset asthma. The asthma-symptom score was highest in group A, lower in group B and significantly lower in group C. When symptoms were related to the degree of obstruction (asthma index), it was higher in the young asthmatics than in both groups of elderly patients. In conclusion, elderly patients with long-standing asthma had more severe airway obstruction than patients with recently acquired disease. Older patients particularly those with long-standing disease complained less about asthma symptoms. Within the various groups of patients, subjective symptoms of asthma were negatively related to asthma duration.

Respiratory muscle training in patients with moderate to severe myasthenia gravis

BACKGROUND

Myasthenia gravis (MG) is a specific autoimmune disease characterized by weakness and fatigue. MG may affect also the respiratory muscles causing symptoms that may vary from dyspnea on severe exertion to dyspnea at rest. This study was undertaken in order to determine the effects of respiratory muscle training on respiratory muscle performance, spirometry data and the grade of dyspnea in patients with moderate to severe generalized MG.

METHODS

Eighteen patients with MG were studied and divided into 2 groups: Group A included 10 patients (3 males and 7 females aged 29-68) with moderate MG, and Group B that included 8 patients (5 males and 3 females aged 21-74) with severe MG. Patients in Group A received both inspiratory and expiratory muscle training for 1/2 h/day, 6 times a week, for 3 months, while patients in Group B followed the same protocol but had inspiratory muscle training only.

RESULTS

Mean PImax increased significantly from 56.6 +/- 3.9 to 87.0 +/- 5.8 cm H2O (p < 0.001) in Group A, and from 28.9 +/- 5.9 to 45.5 +/- 6.7 cm H2O (p < 0.005) in Group B. The mean PEmax also increased significantly in patients in Group A, but remained unchanged in the patients in Group B. The respiratory muscle endurance also increased significantly, from 47.9 +/- 4.0 to 72.0 +/- 4.2%, p < 0.001, in patients of Group A, and from 26.0 +/- 2.9 to 43.4 +/- 3.8, p < 0.001, in patients in Group B. The improved respiratory muscle performance was associated with a significant increase in the FEV1 values, and in the FVC values, in patients of both groups. Mean dyspnea index score also increased significantly from 2.6 +/- 0.8 to 3.6 +/- 0.4 (p < 0.005) in Group A, and from 0.7 +/- 0.2 to 2.0 +/- 0.2 (p < 0.001) in Group B.

CONCLUSIONS

Specific inspiratory threshold loading training alone, or combined with specific expiratory training, markedly improved respiratory muscle strength and endurance in patients with MG. This improvement in respiratory muscle performance was associated with improved lung function and decreased dyspnea. Respiratory muscle training may prove useful as a complementary therapy with the aim of reducing dyspnea symptoms, delay the breathing crisis and the need for mechanical ventilation in patients with MG.

Adolescent physical abuse: risk for adolescent psychiatric disorders

OBJECTIVE

The present study examined whether physical abuse functions as an additional risk factor for adolescent psychopathology after other important known risk factors are controlled for.

METHOD

The authors recruited 99 adolescents aged 12 to 18 years directly from the New York State Department of Social Services after official documentation of physical abuse. The abused adolescents were compared to 99 nonabused adolescents matched for age, gender, race, and community income. Diagnostic interviews and measures of selected risk factors for psychopathology were administered to the adolescents and their parents and then entered into a multiple logistic regression model testing the added risk contributed by physical abuse to adolescent psychopathology.

RESULTS

Physical abuse added significantly to other risk factors in accounting for lifetime diagnoses of major depression, dysthymia, conduct disorder, drug abuse, and cigarette smoking. Physical abuse also contributed significantly to prediction of current adolescent unipolar depressive disorders, disruptive disorders, and cigarette smoking.

CONCLUSIONS

Since physically abused adolescents are at greater risk for the development of psychiatric disorders, recognition of adolescent abuse and the provision of psychiatric and substance abuse services may reduce morbidity.

Time-dependent changes in the density and hemoglobin F content of biotin-labeled sickle cells

Sickle red blood cells (RBC) are subject to a number of important cellular changes and selection pressures. In this study, we validated a biotin RBC label by comparison to the standard 51Cr label, and used it to study changes that occur in sickle cells as they age. Sickle RBC had a much shorter lifespan than normal RBC, but the two labels gave equivalent results for each cell type. A variable number of sickle, but not normal, RBC disappeared from the circulation during the first few hours after reinfusion. The number of biotinylated sickle reticulocytes was decreased by 50% after 24 h and 75% after 48 h, with a gradual decrease in the amount of reticulum per cell. The labeled sickle cells exhibited major density increases during the first 4-6 d after reinfusion, with smaller changes thereafter. A small population of very light, labeled sickle RBC was essentially constant in number after the first few days. Fetal hemoglobin (HbF) content was determined in isolated biotinylated sickle RBC after reinfusion, allowing an estimate of lifespan for RBC containing HbF (F cells) and non-F cells. The lifespan of sickle biotinylated RBC lacking HbF was estimated to be approximately 2 wk, whereas F cells survived 6-8 wk.

Alzheimer's disease under managed care: implications from Medicare utilization and expenditure patterns

BACKGROUND

Little information is available about the costs, utilization patterns, and the delivery system used by Medicare beneficiaries with chronic illnesses. This information will become increasingly important as more Medicare beneficiaries with chronic illness enroll in managed care plans and delivery systems must be developed to meet their needs.

OBJECTIVES

To analyze health care expenditures and utilization patterns for Medicare beneficiaries with dementia of the Alzheimer type (DAT) and compare them with those of all Medicare beneficiaries.

DESIGN

A cross-sectional study.

SETTING

Practices providing services to Medicare beneficiaries in the U.S.

SUBJECTS

Aged Medicare beneficiaries with DAT in fiscal year (FY) 1992.

MEASUREMENTS

Medical expenditures and utilization patterns.

RESULTS

In FY 1992, per capita Medicare expenditures for 9323 patients with DAT were $6208, or 1.9 times the per capita expenditure for all 1,221,615 beneficiaries in our sample. Inpatient care accounted for 62.7% of expenditures. Internal medicine was the specialty identified with the largest proportion of expenditures, but no single specialty accounted for the majority of care. Payments increased with comorbid conditions such as heart failure, chronic pulmonary diseases, and cerebrovascular disease.

CONCLUSION

Current Medicare capitation payments to managed care plans may not meet the higher expected annual costs of care for beneficiaries with DAT. In turn, physicians (or physician groups) who accept capitation for Medicare beneficiaries with DAT should also consider how capitation rates are established by managed care plans and should learn ways to reduce financial risk.

Prophylactic inspiratory muscle training in patients undergoing coronary artery bypass graft

Pulmonary complications after cardiac surgery are a leading cause of postoperative morbidity and mortality. Respiratory muscle weakness may contribute to the postoperative pulmonary abnormalities. We hypothesized that: (1) there is a decrease in inspiratory muscle strength (PImax at residual volume) and endurance (Pmpeak/PImax) following coronary artery bypass graft (CABG); (2) this weakness is associated with reduced pulmonary function tests (PFTs), impaired gas exchange, and a higher rate of pulmonary complications; and (3) prophylactic inspiratory muscle training (IMT) can prevent those changes. Eighty-four candidates for CABG, with ages ranging from 33 to 82 years, were evaluated prior to operation and randomized into two groups: 42 patients underwent IMT using a threshold trainer for 30 min/day for 2 weeks, 1 month before operation (group A); 42 patients served as a control group and underwent sham training (group B). There was a significant decrease in respiratory muscle function, PFTs, and gas exchange in the control group following CABG, whereas these parameters remained similar to those before entering the study in the training group. The differences between the groups were statistically significant. In addition 11 (26%) patients in the control group but only 2 (5%) in the training group needed postsurgical mechanical ventilation longer than 24 hours, CABGs have a significant deteriorating effect on inspiratory muscle function, PFTs, and arterial blood gases. The decrease in these parameters can be prevented by prophylactic inspiratory muscle training, which may also prevent postsurgical pulmonary complications.