Habitat factors influencing distributions of Anaplasma phagocytophilum and Ehrlichia chaffeensis in the Mississippi Alluvial Valley.

Human monocytotropic ehrlichiosis (HME), caused by the bacterium Ehrlichia chaffeensis, and human granulocytic anaplasmosis (HGA), caused by the bacterium Anaplasma phagocytophilum, are two emerging tick-borne zoonoses of concern. Factors influencing geographic distributions of these pathogens are not fully understood, especially at varying spatial extents (regional versus landscape) and resolutions (counties versus smaller land units). We used logistic regression to compare influences of physical environment, land cover composition, and landscape heterogeneity on distributions of A. phagocytophilum and E. chaffeensis at multiple spatial extents. Pathogen presence or absence was determined from white-tailed deer (Odocoileus virginianus) serum samples collected from 1981 to 2005. Ecological predictor variables were derived from spatial datasets that represented deer density, elevation, land cover, normalized difference vegetation index (NDVI), hydrology, and soil moisture. We used three strategies (a priori, exploratory, and spatial extent) to develop models. Best fitting models were applied within a geographic information system to create predictive probability surfaces for each bacterium. Ecological predictor variables generally resulted in better fitting models for E. chaffeensis than A. phagocytophilum (90.5% and 68% sensitivity, respectively), possibly as a result of differences in the natural histories of tick vectors. Although alternative model development strategies produced different models, in all cases bacteria presence or absence was affected by a combination of soil moisture or flooding variables (thought to affect primarily tick vectors) and forest cover or NDVI variables (thought to affect primarily mammalian hosts). This research demonstrates the potential for modeling the distributions of microscopic tick-borne pathogens using coarse regional datasets and emphasizes the importance of forest cover and flooding as environmental constraints, as well as the importance of considering ecological variables at multiple spatial extents.

Vimentin and lipid metabolism.

Vimentin IFs form close associations with the lipid droplets that are characteristic of adipose and steroidogenic cells. There is good evidence that changes in vimentin expression or organization can alter the metabolism of specific lipid components in cultured preadipose and adrenal cell lines. However, the effect of vimentin on triglyceride stability that is observed in preadipose cells is not obviously reflected in adrenal cells or fibroblasts. Conversely, an effect of vimentin on the metabolism of lipoprotein-derived cholesterol observed in adrenal cells is not apparent in preadipose cells. While the complexity of the phenotypes observed in these cells might be associated with cell-type-specific differences in the metabolism of triglycerides or lipoprotein-derived cholesterol, these studies have not yet revealed a general role of vimentin in lipid metabolism that would indicate a common mechanism in all cell types. A key issue that needs to be addressed is whether the effect of vimentin IFs on the stability of triglycerides or the trafficking of GSLs and lysosomal cholesterol is due to a direct participation of vimentin IFs in some aspect of these processes, or perhaps reflects an indirect response of the lipid metabolism of these cells to an effect of vimentin on some other cellular process.

Accidental salicylate intoxication in a hemodialysis patient.

A 61-year-old woman receiving long-term hemodialysis presented with symptoms of tinnitus, insomnia, malaise, and disequilibrium. On close questioning, it was discovered that she had received a prescription for salsalate (Disalcid) from a consulting physician who had evaluated her for joint pain. This tablet was similar in appearance to a dried aluminum hydroxide gel preparation (Alu-tab) that the patient was taking as a phosphate binder. She had mistakenly been taking six Disalcid tablets with each meal. Her salicylate level was 5.86 mmol/L, but she had no change in her serum electrolyte levels or acid-base status. When the salsalate treatment was stopped and regular dialysis treatments were continued, the symptoms of salicylism resolved. This case illustrates one of the potential dangers of polypharmacy in patients with chronic disease. The midl course was probably due to ongoing hemodialysis, which prevented the appearance of the usual acid-base abnormalities of salicylate intoxication.

The hypervariable region in the genes coding for entomopathogenic crystal proteins of Bacillus thuringiensis: nucleotide sequence of the kurhd1 gene of subsp. kurstaki HD1.

One of the genes for the entomophatogenic crystal protein of Bacillus thuringiensis (subsp. kurstaki strain HD1) has been cloned in Escherichia coli, and its nucleotide sequence determined completely. The gene is contained within a 4360-bp-long HpaI-PstI DNA restriction fragment and codes for a polypeptide of 1,155 amino acid residues. The protoxin protein has a predicted Mr of 130,625. The E. coli-derived protoxin gene product is biologically active against Heliothis virescens larvae in a biotest assay. Extensive computer comparisons with other published B. thuringiensis subsp. kurstaki strains HD1, HD73, and B. thuringiensis subsp. sotto gene sequences reveal hypervariable regions in the first half of the protoxin coding sequence. These regions are responsible for the biological activity of the protein product of the cloned gene, and may explain the different biological activities of these different protoxins.

Normalizing hematocrit in dialysis patients improves brain function.

Recombinant human erythropoietin (rHuEPO) treatment has been shown to improve brain and cognitive function in anemic dialysis patients. Significant debate continues, however, regarding the appropriate target hematocrit (Hct) that will lead to the greatest benefits while considering possible side effects and costs of rHuEPO. Current practice results in an Hct averaging only 31% to 32% in dialysis patients, a level less than that achieved in the initial clinical trials and well less than normal. This study was designed to evaluate dialysis patients at the current practice Hct levels versus normal Hct levels (40% to 45%) to see if improvement in brain function resulted. Twenty patients with end-stage renal disease (ESRD) currently being treated with rHuEPO (mean Hct, 31.6%) were administered additional rHuEPO to reach normal Hct levels (mean, 42. 8%). Electroencephalogram (EEG) frequency analysis showed a significant decrease in EEG slowing at greater Hct values, and the auditory oddball and Continuous Performance Task tasks yielded significant electrode and time-by-electrode effects for P300 amplitude. Changes in P300 latency significantly correlated with increased Hct in the auditory oddball task. These findings suggest that further correction of anemia to normal Hct levels may result in continued improvement in neurocognitive function by improving the ability to sustain attention in easier tasks and by enhancing the ability to recognize, discriminate, and hold stimuli in memory for more difficult tasks.

Patient-related predictors of rehabilitation use for community-dwelling older Americans.

OBJECTIVE: To determine patient factors that predict use of physical or occupational therapy (PT/OT) services by elderly people. DESIGN: Time-series study of the relationship of PT/OT use to a variety of characteristics present at baseline. PARTICIPANTS: Eight-hundred nine community-dwelling men and women aged 65 and older. SETTING: The Medicare Screening and Health Promotion Trial at UCLA. MAIN OUTCOME MEASURES: Use of PT/OT services, as reported in a telephone survey 1 year after initial information was obtained on the same subjects by the baseline telephonic survey. RESULTS: Fifteen percent of the sample used PT/OT within 12 months of baseline. In multiple logistic regression analysis, PT/OT use was significantly less frequent among racial minorities, less well educated groups, and the oldest age group. PT/OT use was higher among those who had both functional disability and the presence of arthritis, heart or lung disease, or a prior history of stroke. However, neither functional disability alone nor the presence of arthritis, cardiovascular or lung disease, in the absence of limited functioning, was associated with PT/OT use. Patients who had obtained a pneumococcal vaccination or used transportation services were also more likely to receive PT/OT. CONCLUSIONS: Our findings suggest that there may be important sociodemographic inequalities in the use of rehabilitation services and raise the possibility of inappropriate underuse in certain subgroups. Additional studies are needed to determine whether similar inequalities of PT/OT use are found in other populations and whether rehabilitation is effective in various subgroups.

Health promotion and disease prevention for older adults: opportunity for change or preaching to the converted?

Health promotion and disease prevention for the elderly offer the potential for improving the quality of life for the growing population of older adults, while reducing the economic burden on the health system. Whether this potential can be realized depends, in part, on whether those older adults whose health behaviors put them at risk actually use preventive services when offered the opportunity. In 1988 the Health Care Financing Administration began a series of health promotion demonstrations to address health issues related to older adults. This article reports on program participation at one of the five demonstration sites. Over 1,900 community-dwelling Medicare beneficiaries who receive their health care through fee-for-service providers were enrolled in the demonstration. These enrollees were randomly assigned to control and experimental groups, with the latter offered health screening and promotion services. Nine hundred-seventy-three of the experimental subjects and 938 of the control subjects completed a lengthy telephone interview, which determined each person's use of preventive services and practices. Although all 973 experimental subjects were invited by letter and follow-up telephone calls to attend these free-of-charge, Medicare-provided sessions, not everyone attended. We analyzed 17 health behaviors of those who attended the first session and those who did not. Those engaging in these preventive behaviors were neither more nor less likely to attend the screening services. Thus, we found neither "favorable" nor "unfavorable" selection bias in the use of these preventive services.

Mammography use in older women with regular physicians: what are the predictors?

Results of a longitudinal study of 1,050 women 65 years of age and older under the care of faculty internists demonstrate that individual and sociodemographic factors predict mammography use. The majority of the sample (79%) had received a mammogram within the past two years. Multiple logistic regression analyses of findings from a telephone survey showed that mammographic screening was significantly higher among women who had recently received a Pap smear, whose annual household incomes exceeded $30,000, and whose personal health care habits were preventively oriented; they used more preventive services such as routine dental care and engaged in more preventive behaviors such as seat-belt use and routine exercise. Mammography use was significantly higher among those 75 or younger. These findings suggest that enhancing patient preventive orientations should be part of interventions designed to increase screening. Medical Subject Headings (MeSH): appropriateness review, preventive health services, utilization, aged, Medicare.

Differences in managed care drug formularies: what can consumers learn?

Pharmaceutical coverage has become an especially important issue in health plan design. This article develops an objective measure of drug coverage generosity in managed care drug formularies. Formulary generosity is important because patients respond differently to drugs within a therapeutic class, and so there is benefit in offering a wide variety of products to prescribing physicians. The measure of coverage generosity considers not only the number of products offered to patients through a formulary, but whether plans systematically exclude more expensive products. The correlation between formulary generosity and health plan member satisfaction is analyzed to see if formulary generosity is perceived by subscribes to be related to perceived health plan quality. The findings are that plans vary widely in offering access to pharmaceuticals but that generosity is not highly correlated with health plan satisfaction.

Economic aspects of drug substitution.

One of the major directions of health policy is the attempt to contain expenditures on pharmaceuticals by encouraging substitution of generic for brand name drug products. Yet, a major marketing survey of prescribing and dispensing patterns in California in 1977 found relatively little drug substitution occurring, and in fact substitution of more expensive products occurred more frequently than did substitution of less expensive products. This article tests alternative models of pharmacy dispensing behavior to better explain substitution patterns and it estimates price functions to measure the extent to which cost savings on generic products are passed on to consumers.

The effect of Medicaid formularies on the availability of new drugs.

This study expands our previous work on the availability of new drug introductions to poor patients in states in the USA with restrictive Medicaid formularies. In particular, it focuses on the experience of 9 states over the period 1979 to 1985. In these states, a typical new drug took 20 months after FDA approval to gain acceptance onto the Medicaid formulary. New drug introductions were available to Medicaid patients less than 40% of the time during their first 4 years of market life. Restrictions on availability also extended to drugs ranked high in terms of both therapeutic and commercial importance. There was substantial variation observed across states and therapeutic categories. While formularies are prohibited under legislation recently enacted by the US Congress, state governments may attempt to continue to restrict access to expensive new medicines through prior approval systems. This is an issue that warrants future attention and study.

The social drug lag: an examination of pharmaceutical approval delays in Medicaid formularies.

Several states have enacted restrictive drug formularies in order to control the costs of their Medicaid pharmaceutical programs. This study investigates the restrictiveness of these formularies by analyzing the delay in approving new drug products for Medicaid reimbursement. A restrictiveness index is developed which relates the drug product months which are denied to Medicaid patients to the potential product months of availability if all products which were newly approved for general use were simultaneously made available to the Medicaid population. The study then relates the restrictiveness of state formularies to Medicaid drug program costs and to total Medicaid program costs. We find that restrictiveness of formularies is not associated with lower drug costs, but that total Medicaid costs are lower in states with more restrictive formularies. We suggest that restrictive formularies may occur in states with other Medicaid cost-containment measures, so that total Medicaid expenditures are contained in those states, even though there is no reduction in drug expenditures.

The effects of occupational exposure to chlorpyrifos on the peripheral nervous system: a prospective cohort study.

AIMS: To determine whether chronic occupational exposure to chlorpyrifos at levels associated with various aspects of manufacturing produced a clinically evident or subclinical peripheral neuropathy. METHODS: Clinical and quantitative nerve conduction study (NCS) examinations were performed on two occasions on chlorpyrifos manufacturing workers who had measurable chlorpyrifos exposure and a referent group. Baseline evaluations were performed on 53 of 66 eligible chlorpyrifos subjects and on 60 of 74 eligible referent subjects; one-year evaluations were completed on 111 of the 113 subjects evaluated at baseline. RESULTS: Chlorpyrifos and referent groups differed significantly in measures of 3,5,6 trichloro-2-pyridinol excretion and plasma butyrylcholinesterase (BuChE) activity, indicating substantially higher exposures among chlorpyrifos subjects. Few subjects had clinically important neurological symptoms or signs. NCS results were comparable to control values, and there were no significant group differences in NCS results at baseline, one year, or change over one year. No chlorpyrifos subject fulfilled conventional criteria for confirmed peripheral neuropathy at baseline or one-year examinations. The odds ratios for developing any diagnosable level of peripheral neuropathy among the chlorpyrifos subjects was not increased at baseline or at one year compared to referents at baseline. Mixed regression models used to evaluate subclinical group-by-time interactions showed numerous significant NCS differences attributable to near-nerve temperature differences among all subjects between the baseline and one-year examinations, but only a few disparate effects related to group. CONCLUSIONS: Chronic chlorpyrifos exposure during the manufacturing process sufficient to produce biological effects on BuChE activity was not associated with clinically evident or subclinical peripheral neuropathy at baseline or with measurable deterioration among chlorpyrifos subjects compared to referents after one year of additional exposure.

Sexual activity and satisfaction among very old adults: results from a community-dwelling Medicare population survey.

This article explores the relationship between sociopsychological factors, sexual activity, and sexual satisfaction in a sample of 1,216 elderly people (mean age = 77.3). Almost 30% had participated in sexual activity in the past month and 67% were satisfied with current level of sexual activity. Men are more likely to be sexually active, but less apt than women to be satisfied with their level of sexual activity. Regarding predictors of sexual activity, for men the strongest predictors were being younger and having more education. For women, the strongest predictor by far was being married. For both men and women the strongest predictors for satisfaction were being sexually active and having positive mental health scores. In summary, the main variables predicting sexual activity were being married, having more education, being younger, being male, and having good social networks. The main predictors for satisfaction with sexual activity were, in addition to being sexually active, being female, having good mental health, and better functional status.

The costs of a pediatric hospice program.

The recent literature on economic issues of hospice care leaves several questions unanswered. The most important issue concerns how this type of care can be made financially attractive to patients and families for whom it is a medical option. A major study of a home-based pediatric hospice program permitted a more careful analysis than was previously feasible of the charges for hospice care and how those charges are paid. Data on provider utilization and duration in the program were obtained retrospectively on 177 patients. Costs of incidental expenditures and indirect costs were obtained prospectively from the families of 27 patients. A cost model was developed which is general enough to be used by other hospitals that might contemplate establishing a similar hospice program. Our findings are that insurance coverage, especially for publicly funded patients, is likely to be a major impediment for families deciding whether or not to use a hospice program at home.

Enrolling community physicians and their patients in a study of prevention in the elderly.

Enrollment of senior citizens in a community Medicare demonstration project to explore the efficacy of preventive health screening and health education was accomplished by using a two-stage process. This process consisted of initial communication with community physicians through the University of California at Los Angeles Clinical Faculty Association to establish credibility for the program. Physicians who agreed to participate then selected potential participants to receive, by mail, a description of the study and an introductory letter from their own physician. Followup and actual enrollment of participants was then handled by the study team. A total of 57.6 percent of the elderly people approached agreed to participate in the study.

Are retrospective peer-review transfusion monitoring systems effective in reducing red blood cell utilization?

OBJECTIVE: This research used a study-control group design and examined data collected from five hospitals to evaluate the effectiveness of retrospective peer-review systems on reducing utilization of red blood cells (RBCs). DESIGN: The effects of retrospective peer-review systems were studied in three parts: (1) trends of RBC utilization were compared by the slopes of linear regression lines that assessed the effect of time on RBC utilization among four study hospitals and one control hospital, (2) diagnosis-specific RBC utilization was compared between the control hospital and one matched study hospital, and (3) the effect of the retrospective review system of one study hospital was assessed by linear regression using data accumulated 1 year before and 2 years after implementation of the program. RESULTS: Three study hospitals showed no significant changes in RBC utilization during the 10-month study period. One study hospital and the control hospital demonstrated trends of reduced RBC use with negative slopes of regression lines; however, there was no difference in the degree of the two slopes, and the diagnosis-specific RBC utilization was not lower at the study hospital than at the control hospital. Furthermore, implementation of the retrospective peer-review system at one study hospital demonstrated no effect on RBC utilization. CONCLUSIONS: We conclude that the retrospective peer-review systems implemented at these four hospitals had no effect on reducing red blood cell utilization.

A hepatitis C virus (HCV) core protein derived peptide inhibits HCV specific lymphocyte proliferation.

T helper lymphocytes are important regulatory cells for the immune response in chronic hepatitis C. They recognize peptides, which are generated from the viral proteins by antigen processing and are bound to MHC (major histocompatibility complex) class II molecules. However, antigen processing might also result in non-immunogenic peptide fragments that can modify T cell activation. - To identify such peptide fragments in hepatitis C, we studied binding of 15 synthetic HCV core derived peptides to MHC class II molecules of 9 human homozygous typing B cell lines (HT-BCLs) as well as T cell proliferation in 41 HLA-typed patients with chronic hepatitis C. - We identified a peptide (HCV core aa 59-83) which bound to 7 HT-BCLs, whereas PBMC of only 2 out of 36 patients with the corresponding HLA-DR alleles proliferated in response to this peptide. Competition experiments indicated that small amounts of peptide aa 59-83 specifically inhibited the proliferative response to the recombinant core protein but not to core derived immunogenic peptides. Our data show that a peptide fragment from the HCV core region aa 59-83 can interfere in vitro with immune recognition of the HCV core protein.

Replacement of amalgams with crowns: a cost-effectiveness analysis.

No formal analyses comparing the treatment alternatives of replacing a failed amalgam with either another amalgam or crown have been done to determine the optimum treatment strategy based on lifetime costs to the patient. Using decision analysis, a computer model was developed of the lifetime restorative needs of an adult's posterior tooth. A cost-effectiveness analysis of large amalgams vs crowns was then done to determine the optimum strategy. According to the analyses, the optimum treatment decision is to attempt to replace the failed first amalgam with another amalgam, instead of with a crown. When this amalgam restoration fails, then the subsequent replacement may be with a crown. Potential lifetime cost savings were between 11% and 24% if the first replacement was an amalgam. This study concludes that the technique of decision analysis provides the dental community with an effective evaluation tool for the study of clinical decision-making, taking into account all levels of clinical uncertainty.

Patient satisfaction on AIDS and oncology special care units and integrated units: a pilot study.

The authors assessed patients' satisfaction with their nursing care in seven hospitals. Five of the hospitals utilized the special care unit (SCU) method of delivering care to AIDS or oncology patients; three had SCUs for AIDS patients. All seven of the hospitals had integrated units (IUs) where general medical, oncology, and/or AIDS patients were received in various proportions. Satisfaction with nursing care was measured with the Risser Patient Satisfaction Instrument. Patient satisfaction with nursing care was shown to be a function of delivery method; AIDS and oncology patients on SCUs expressed greater satisfaction with their care than medical, oncology, or AIDS patients on IUs (p less than .001). Patient satisfaction with nursing care was greater among whites than nonwhites. Also, some major sociodemographic and case mix variables, such as age, employment status, and diagnosis, were not associated with patient satisfaction directly; in other instances, the associations initially seen did not hold when delivery method (SCU vs. IU) and race were controlled for in a linear regression analysis.