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.

Endogenous versus exogenous fatty acid availability affects lysosomal acidity and MHC class II expression.

Although the immune system, inflammation, and cellular metabolism are linked to diseases associated with dyslipidemias, the mechanism(s) remain unclear. To determine whether there is a mechanistic link between lipid availability and inflammation/immune activation, we evaluated macrophage cell lines incubated under conditions of altered exogenous and endogenous lipid availability. Limiting exogenous lipids results in decreased lysosomal acidity and decreased lysosomal enzymatic activity. Both lysosomal parameters are restored with the addition of oleoyl-CoA, suggesting that fatty acids play a role in the regulation of lysosomal function. Cell surface expression of major histocompatibility complex (MHC)-encoded molecules is also decreased in the absence of exogenous lipids. Additionally, we observe decreased gamma-interferon stimulation of cell surface MHC class II. Using cerulenin to limit the endogenous synthesis of fatty acids results in decreased cell surface expression of MHC class II but does not appear to alter lysosomal acidity, suggesting that lysosomal acidity is dependent on exogenous, but not endogenous, fatty acid availability. Testing these conclusions in an in vivo mouse model, we observed statistically significant, diet-dependent differences in lysosomal acidity and MHC class II cell surface expression. Collectively, these data demonstrate a mechanistic link between lipid availability and early events in the immune response.

[Patients as partners. Tumor patients and their participation in medical decisions]. / Patienten als Partner in der letzten Lebensphase. Erste Ergebnisse und Perspektiven eines Modellvorhabens.

Between March 2002 and August 2003 as part of the research project "Patients as partners -- tumour patients and their participation in medical decisions" tumour patients undergoing palliative therapy (n=272) were interviewed and asked about their level of information, their desired place to die and whether they had prepared an advance directive. Furthermore, 72 relatives of deceased patients who had been looked after by the project's palliative care team were given a similar questionnaire including questions concerning their knowledge about disease and prognosis, the actual place of death and the relevance of advance directives. According to patients and relatives, information particularly about prognosis is unsatisfactory. Of the inter-viewed patients, 75% said they wanted to die at home and 15% in a hospital. According to their relatives, 36% of the patients looked after by the palliative care team had an advance directive. The survey of the relatives showed a significant relation between the preparation of an advance directive and dying at the desired place. According to the relatives, medical and health reasons, hope for an improvement up to the very end,acute worsening of the condition and deficits in medical care were important reasons for dying in hospital against the patient'swish. In future, advance directives should be used as an aid for communication and the planning of care. Therefore, cooperation between doctors and patients based on a partnership is necessary. The required competence in communication should be improved.

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.

[Ambulant care of patients in the terminal phase of malignant tumor: answers by general practioners in Thuringia to a questionnaire]. / Ambulante Versorgung von Tumorpatienten im finalen Stadium. Ergebnisse einer schriftlichen Hausärztebefragung in Thüringen.

BACKGROUND AND OBJECTIVE: Palliative care and care of the dying are not widely taught in medical education. Yet, through the guidelines of the Federal Medical Council (Bundesärztekammer), doctors are obliged professionally to accompany the dying process. Systematic studies concerning doctors' motivation and action in this special situation are rare. This study aims to evaluate the views and attitudes of general practitioners towards the care for cancer patients in the terminal stage of disease. METHODS: In association with the project of the German Ministry of Health "Patienten als Partner-Tumorpatienten und ihr Mitwirken in medizinischen Entscheidungen" ("Patients as partners: patients with malignant tumor and their collaboration in medical decision making"), a questionnaire was designed for general practitioners based on qualitative interviews. The self-guiding questionnaire comprised questions concerning death and dying, patient-doctor relationship and day-to-day medical actions. RESULTS: 505 general practitioners (GPs) received the questionnaires. 170 were filled in and sent back (33%). The GPs felt responsible for the care of the dying patients. Pain control was the main goal (97%). Symptom control was thought to be important/very important in 87%, the application of life-prolonging measures in 12 %. Basic analgesic medication was prescribed by 93% of GPs. 89%/77% of the general practitioners answered that they were satisfied with the technical equipment of the hospital/clinic, whereas there was a dissatisfaction with psychological and spiritual support. CONCLUSION: General practitioners widely accept their responsibility for the care of the dying patients. Pain control is the major goal in this group of patients. Some items (use of co-analgesia, prescription of peak analgesia) seem to be open to improvements. Despite a high motivation, general practitioners show their dissatisfaction with some aspects of the care for dying people. Palliative care teams could be helpful in this situation.

Seventeen novel mutations that cause profound biotinidase deficiency.

We report 17 novel mutations that cause profound biotinidase deficiency. Six of the mutations are due to deletions, whereas the remaining 11 mutations are missense mutations located throughout the gene and encode amino acids that are conserved in mammals. Our results increase the total number of different mutations that cause biotinidase deficiency to 79. These additional mutations will undoubtedly be helpful in identifying structure/function relationships once the three-dimensional structure of biotinidase is determined.

Aflatoxin levels in corn available as wild turkey feed in Georgia.

Samples of corn available as wildlife feed from retailers throughout Georgia (USA) were collected during April 1997 and analyzed for aflatoxin to determine if levels harmful to wild turkeys (Meleagris gallopavo) were present. Three of 31 (10%) samples collected from a 40-country area were positive. An enzyme-linked immunosorbent assay qualitatively determined that two samples contained from 0 to 20 ppb aflatoxin. A chromatography analysis of a third sample measured 380 ppb total aflatoxin. A small percentage of our sample of wildlife feed collected during one season contained levels of aflatoxin that may cause harm to turkeys, especially poults. However, because aflatoxin levels ranging from 100 to 400 ppb may cause liver dysfunction and immunosuppression in turkey poults and other wildlife, grains known to be contaminated with aflatoxin at levels unacceptable for domestic animal feeds (> or =100 ppb) should not be sold as wildlife feed. Further analyses of grains sold as wildlife feed should be conducted to address this potential problem.

Lipidation of T helper sequences from hepatitis C virus core significantly enhances T-cell activity in vitro.

Successful elimination of the hepatitis C virus (HCV) during acute infection has been linked to strong HCV-specific in vitro T-cell proliferation, whereas T cells from patients with chronic hepatitis C respond only weakly to HCV antigens. Lipid-coupled peptides are immunostimulants, which might provide a basis for novel therapeutic strategies against HCV. Therefore, in 20 patients with chronic hepatitis C, we studied whether tri-palmitoyl-S-cysteine-coupled peptides could modify in vitro T-cell proliferation (by [3H]thymidine uptake) in response to virus core and NS4. The lipopeptides corresponded to five immunodominant T helper epitopes of HCV core. Contrary to unmodified peptides, the lipopeptides specifically enhanced [3H]thymidine uptake in response to HCV antigens but not to a non-HCV related control antigen. They increased the frequency of responders (stimulation index, SI > or = 4) to core (13/20 versus 2/20; p = 0.0008) and NS4 (20/20 versus 7/20; p < 0.0001) among our patients with chronic hepatitis C. This immunostimulatory effect was dose-dependent, and was observed specifically with lipopeptides corresponding to the HCV epitopes. Our data demonstrate that the poor in vitro T-cell proliferation of patients with chronic hepatitis C can be improved when T cells are co-stimulated with HCV core-derived T helper lipopeptides, while the same peptides in unlipidated form had no effects. Thus, lipopeptides corresponding to HCV T-cell epitopes may offer novel immunomodulatory strategies against HCV.

Paranemin and the organization of desmin filament networks.

De novo expression of vimentin, GFAP or peripherin leads to the assembly of an extended intermediate filament network in intermediate filament-free SW13/cl.2 cells. Desmin, in contrast, does not form extended filament networks in either SW13/cl.2 or intermediate filament-free mouse fibroblasts. Rather, desmin formed short thickened filamentous structures and prominent spot-like cytoplasmic aggregates that were composed of densely packed 9-11 nm diameter filaments. Analysis of stably transfected cell lines indicates that the inability of desmin to form extended networks is not due to a difference in the level of transgene expression. Nestin, paranemin and synemin are large intermediate filament proteins that coassemble with desmin in muscle cells. Although each of these large intermediate filament proteins colocalized with desmin when coexpressed in SW-13 cells, expression of paranemin, but not synemin or nestin, led to the formation of an extended desmin network. A similar rescue of desmin network organization was observed when desmin was coexpressed with vimentin, which coassembles with desmin, or with keratins, which formed a distinct filament network. These studies demonstrate that desmin filaments differ in their organizational properties from the other vimentin-like intermediate filament proteins and appear to depend upon coassembly with paranemin, at least when they are expressed in non-muscle cells, in order to form an extended filament network.

Flow cytometric analysis of peptide binding to major histocampatibility complex class I for hepatitis C virus core T-cell epitopes.

BACKGROUND/METHODS: To characterize the repertoire of T-cell epitopes on the hepatitis C virus (HCV) core protein, we studied major histocompatibility complex (MHC) class I binding of 75 decapeptides on 20 human B-cell lines and murine spleen cells using a flow cytometric assay. The results were compared with MHC class I stabilization on T2 cells, the SYFPEITHI algorithm, and known T-cell epitopes from the literature. RESULTS: Binding of peptides proved to be specific for MHC class I molecules. We observed peak fluorescence signals at positions amino acids (aa) 35-44, aa 87-96, aa 131-140, and aa 167-176 in virtually all HLA-A2-positive cell lines. These sites corresponded to T-cell epitopes predicted by SYFPEITHI and the positions of known T-cell epitopes, whereas T2 stabilization was at variance for two peptides. The assay was applied to HLA-A2-negative cells and murine spleen cells without further modification, and identified additional peptides, corresponding to known T-cell epitopes. CONCLUSIONS: Peptide binding to different MHC class I alleles can be mapped rapidly by a flow cytometric assay and enables a first orientation on the sites of possible T-cell epitopes. Application of this assay to HCV core suggests a rather limited repertoire of epitopes in the Caucasoid population.

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.

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.

Effect of sodium benzoate in the treatment of atypical nonketotic hyperglycinaemia.

A 6-month-old girl presented with hypotonia and mild psychomotor retardation. Subsequently, an atypical manifestation of a nonketotic hyperglycinaemia was diagnosed, confirmed by significantly reduced activity of the glycine cleavage system in the liver tissue. After the patient developed hypsarrhythmia and had a single cerebral seizure, treatment with both sodium benzoate and dextromethorphan was started. During the following year, the girl was free of seizures with improvement of the EEG activity and showed retarded but continuously progressing psychomotor development. At the age of 20 months she began to walk freely but had generalized muscular hypotonia and moderate mental retardation. Discontinuation of dextromethorphan medication after one year of treatment did not change the clinical and electroencephalographic status. However, after cessation of sodium benzoate therapy, epileptic activity in the EEG and behavioural changes occurred. These changes disappeared promptly after sodium benzoate therapy was reinstituted. Thus, this case of mild atypical nonketotic hyperglycinaemia with only moderate psychomotor retardation and without epilepsy benefited from treatment with sodium benzoate in terms of electroencephalographic and behavioural changes.

Lead poisoning in a northern bobwhite in Georgia.

A northern bobwhite (Colinus virginianus) was observed with partial paralysis on 3 March 1997 and found dead on 8 March 1997 on Di-Lane Plantation Wildlife Management Area (Burke County, Georgia, USA). The juvenile male was necropsied by the Southeastern Cooperative Wildlife Disease Study (Athens, Georgia) and diagnosed with lead toxicosis. The bobwhite had liver tissue lead levels of 399 parts per million wet weight and two worn 1-mm diameter lead shot pellets were found in the gizzard.

Identification of two novel mutations in OCTN2 of three patients with systemic carnitine deficiency.

Systemic carnitine deficiency is a potentially lethal, autosomal recessive disorder characterized by cardiomyopathy, myopathy, recurrent episodes of hypoketotic hypoglycemia, hyperammonemia, and failure to thrive. This form of carnitine deficiency is caused by a defect in the active cellular uptake of carnitine, and the gene encoding the high affinity carnitine transporter OCTN2 has recently been shown to be mutated in patients suffering from this disorder. Here, we report the underlying molecular defect in three unrelated patients. Two patients were homozygous for the same missense mutation 632A-->G, which changes the tyrosine at amino acid position 211 into a cysteine (Y211C). The third patient was homozygous for a nonsense mutation, 844C-->T, which converts the arginine at amino acid position 282 into a stop codon (R282X). Reintroduction of wild-type OCTN2 cDNA into fibroblasts of the three patients by transient transfection restored the cellular carnitine uptake, confirming that mutations in OCTN2 are the cause of systemic carnitine deficiency.

Vimentin-dependent utilization of LDL-cholesterol in human adrenal tumor cells is not associated with the level of expression of apoE, sterol carrier protein-2, or caveolin.

SW-13 adrenal tumor cells that lack detectable intermediate filaments (IF-free) exhibit an impaired capacity to esterify lipoprotein-derived cholesterol compared with cells that contain vimentin filaments. IF-free cells were found to synthesize and secrete significant amounts of apoE, while apoE secretion was nearly undetectable in cell lines that spontaneously express vimentin. However, stable transfectants that express a mouse vimentin cDNA exhibited elevated levels of cholesterol esterification and apoE secretion compared with untransfected IF-free cells, indicating that apoE secretion is not directly related to the capacity of these cells to esterify cholesterol. Some of the cell lines that differed in the level of apoE synthesis and secretion had similar levels of apoE mRNA, suggesting that the differences in expression involve a post-transcriptional mechanism. Treatment of these cells with forskolin and IBMX, 8br-cAMP, or TPA had no effect on apoE secretion. The level of sterol carrier protein-2 (SCP(2)) synthesis and the distribution of SCP(2) between membrane and soluble cellular fractions was not observably different in cells that contained or lacked vimentin. SW-13 cell lines contained little or no detectable caveolin-1 or caveolin-2. These studies demonstrate that the difference in the capacity of these adrenal tumor cells that contain or lack vimentin filaments to esterify low density lipoprotein-cholesterol is not obviously associated with the level of expression or distribution of apoE, SCP(2), or caveolins.

D-2-hydroxyglutaric aciduria: further clinical delineation.

It has recently been recognized that D-2-hydroxyglutaric aciduria is a distinct neurometabolic disorder with a severe and a mild phenotype. Whereas the clinical and neuroimaging findings of the severe phenotype were homogeneous among the patients, the findings in the mild phenotype were much more variable, leaving the clinical picture poorly defined. We were able to collect the clinical, biochemical and neuroimaging data on an additional 8 patients with D-2-hydroxyglutaric aciduria, 4 with the severe and 4 with the mild phenotype. With the new information, it becomes clear that the mild phenotype shares the essential characteristics of the severe phenotype. The most frequent findings, regardless of the clinical phenotype, are epilepsy, hypotonia and psychomotor retardation. Additional findings, mainly occurring in the severe phenotype, are episodic vomiting, cardiomyopathy, inspiratory stridor and apnoeas. The most consistent MRI finding is enlargement of the lateral ventricles, occipital more than frontal. Regardless of the clinical phenotype, early MRI shows in addition subependymal cysts and signs of delayed cerebral maturation. Later MRI may reveal multifocal cerebral white-matter abnormalities. Two patients had vascular abnormalities, but it is as yet unclear whether these are related to D-2-hydroxyglutaric aciduria or are incidental findings.

Carnitine transporter OCTN2 mutations in systemic primary carnitine deficiency: a novel Arg169Gln mutation and a recurrent Arg282ter mutation associated with an unconventional splicing abnormality.

Systemic primary carnitine deficiency (CDSP, MIM 212140) is a disorder of fatty acid oxidation manifesting in acute metabolic decompensation or in progressive cardiomyopathy and muscle weakness. Mutations in the plasmalemmal organic cation/carnitine transporter OCTN2 were recently identified in CDSP patients of diverse ethnic backgrounds. We have performed OCTN2 mutation analysis in two unrelated German patients with primary carnitine deficiency and identified three molecular abnormalities. On one of the four chromosomes analyzed, we detected an Arg169Gln missense mutation that affects an arginine residue absolutely conserved in the entire transporter superfamily to which OCTN2 belongs. On the three other chromosomes, we found an Arg282ter nonsense mutation in exon 5. This mutation is embedded into different haplotypes of closely spaced intragenic dimorphisms in our two patients and was recently described in a patient of Asiatic Indian background, so it appears to be a recurrent or ancient founder mutation that may account for more CDSP cases. Finally, we found that the Arg282ter nonsense mutation is associated with a splicing abnormality at the intron 6/exon 7 junction. However, no mutations are present in exon 6, intron 6, or exon 7, suggesting that defective splicing of exon 7 on the Arg282ter allele is due to an unconventional, long-distance mechanism.

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.