Cadwaladerite, Al2(H2O)(OH)4·n(Cl,OH–,H2O), from Cerros Pintados, Chile, defined as a valid mineral species and the discreditation of lesukite

Cadwaladerite, described in 1941 as Al(OH)2Cl·4H2O, and lesukite, described in 1997 as Al2(OH)5Cl·2H2O, are very closely related chemically and structurally, but are found in very different environments. Cadwaladerite was found at the edge of a salar in Chile. Lesukite has been described from a volcanic fumarole and from burning coal seams. Both materials have cubic symmetry with a = 19.788 to 19.859Å. The crystal structure, common to both, consists of a rigid three-dimensional framework of edge- and corner-sharing Al(OH,H2O)6 octahedra that contains large interconnected cavities where loosely held Cl, OH, and H2O are located. The fact that Cl is loosely held within the structure is demonstrated by a dramatic reduction in Cl content after washing the material in distilled water, while the structural integrity is maintained. Herein, cadwaladerite is confirmed as a valid mineral species and lesukite is discredited because the only difference between the two materials is the loosely held extra-framework Cl, OH, and H2O. Cadwaladerite, Al2(H2O)(OH)4·n(Cl,OH,H2O) (Z = 48) takes precedence over lesukite based on the date of description. Material similar to cadwaladerite is found as a corrosion product on some types of nuclear fuel elements and is also closely related to the molecular species used in antiperspirant and water filtration.

Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study

A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.

Thermal History of CBb Chondrules and Cooling Rate Distributions of Ejecta Plumes

It has been proposed that some meteorites, CB and CH chondrites, contain material formed as a result of a protoplanetary collision during accretion. Their melt droplets (chondrules) and FeNi metal are proposed to have formed by evaporation and condensation in the resulting impact plume. We observe that the skeletal olivine (SO) chondrules in CBb chondrites have a blebby texture and an enrichment in refractory elements not found in normal chondrules. Because the texture requires complete melting, their maximum liquidus temperature of 1928 K represents a minimum temperature for the putative plume. Dynamic crystallization experiments show that the SO texture can be created only by brief reheating episodes during crystallization, giving a partial dissolution of olivine. The ejecta plume formed in a smoothed particle hydrodynamics simulation served as the basis for 3D modeling with the adaptive mesh refinement code FLASH4.3. Tracer particles that move with the fluid cells are used to measure the in situ cooling rates. Their cooling rates are ~10,000 K hr-1 briefly at peak temperature and, in the densest regions of the plume, ~100 K hr-1 for 1400-1600 K. A small fraction of cells is seen to be heating at any one time, with heating spikes explained by the compression of parcels of gas in a heterogeneous patchy plume. These temperature fluctuations are comparable to those required in crystallization experiments. For the first time, we find an agreement between experiments and models that supports the plume model specifically for the formation of CBb chondrules.

Association of somatic DNA methylation variability with progression-free survival and toxicity in ovarian cancer patients

BACKGROUND

We have addressed whether inter-individual methylation variation in somatic (white blood cells, WBCs) DNA of ovarian cancer patients provides potential for prognostic and/or pharmacoepigenetic stratification.

PATIENTS AND METHODS

WBC DNA methylation was analysed by bisulphite pyrosequencing at ataxia telangiectasia mutated (ATM), estrogen receptor 1 (ESR1), progesterone receptor (PGR), mutL homologue 1 (MLH1), breast cancer susceptibility gene (BRCA1), secreted frizzled-related protein 1 (SFRP1), stratifin (SFN), retinoic acid receptor beta (RARB) loci and the repetitive element LINE1 in 880 SCOTROC1 trial patients [paclitaxel (Taxol)-carboplatin versus docetaxel (Taxotere)-carboplatin as primary chemotherapy for stage Ic-IV epithelial ovarian cancer].

RESULTS

We observed no significant associations (P < 0.005, after correction for multiple testing) for progression-free survival (PFS) using test and validation sets. However, we did identify mean SFN methylation associated with PFS (hazard ratio, HR = 1.01 per 1% increase in methylation, q = 0.028); particularly in the paclitaxel (HR = 1.01, q = 0.006), but not in the docetaxel arm in stratified analyses. Furthermore, higher methylation within the ESR1 gene was associated with CA125 response (odds ratio, OR = 1.06, q = 0.04) and with neuropathy (HR = 0.95, q = 0.002), but only in the paclitaxel arm of the trial.

CONCLUSIONS

This is the first study linking DNA methylation variability in WBC to clinical outcomes for any tumour type; the data generated on novel prognostic and pharmacoepigenetic DNA methylation biomarkers in the circulation now need independent further evaluation.

Circulating natriuretic peptides in cats with heart disease

BACKGROUND

Circulating natriuretic peptide concentrations are increased in cats with myocardial dysfunction.

HYPOTHESIS

Serum N-terminal fragment of proatrial natriuretic peptide (NT-proANP) and NT-probrain natriuretic peptide (proBNP) concentrations may predict the presence of heart disease (HD) and congestive heart failure (CHF). A positive relationship is also predicted among natriuretic peptide (NP) concentrations, a noninvasive estimate of left ventricular filling pressure (E/E(a)), and an echocardiographic measure of left atrial (LA) size (LA/aortic diameter [Ao]).

METHODS

Serum NP concentrations were measured in 28 healthy control and 50 study cats using sandwich enzyme immunoassays. The study group comprised cats, with HD but no CHF (HD - CHF, n = 17) and cats with CHF (HD + CHF, n = 33). The relationship among NP concentrations, LA size, and E/E(a) was examined. The ability of NP to distinguish control from study cats, and HD - CHF from HD + CHF cats, was explored using receiver operator curve analysis.

RESULTS

NP concentrations were significantly lower in control than in study cats (P= .0001). The NT-proBNP concentrations were positively correlated with LA/Ao ratio (rho= 0.34; P= .02) and with E/E(a) ratio (rho= 0.68; P < .05). An NT-proBNP concentration of 49 fmol/mL gave a sensitivity and specificity of 100 and 89.3%, respectively, for correctly distinguishing 96.2% of control from study cats. Pairwise comparisons of the areas under the curve identified a statistically significant difference (P= .011) between NT-proANP and NT-proBNP to distinguish control from study cats. NT-proANP and NT-proBNP concentrations were significantly higher in HD + CHF cats than in HD - CHF cats (P= .0023 and .0001, respectively).

CONCLUSIONS

Serum concentrations of NT-proANP and particularly NT-proBNP were different in healthy control cats, asymptomatic cats with HD, and cats with CHF, suggesting that measurement of NP concentrations may prove clinically useful as an initial screening test for cats with suspected cardiac disease.

Quality of life and psychological status of patients with implantable cardioverter defibrillators

INTRODUCTION

Implantable cardioverter defibrillators (ICDs) are effective at reducing mortality in patients at high risk for sudden cardiac death (SCD) but can cause psychological distress and reduce quality of life (QOL). The full benefits of ICDs can only be achieved when the patient's QOL and psychological status are maintained. We examined psychological status and QOL post ICD implantation; the relationship of psychological status to QOL; the relationship of time since implantation to psychological status and QOL; and the relationship of time since ICD implantation and age of patient to these variables.

METHODS AND RESULTS

A cross-sectional self-administered assessment of QOL, depression, anxiety, demographic characteristics and cardiovascular health history of patients (n = 48) who had received ICDs within the past 10 years at an urban hospital. Patients who had ICDs for longer experienced worse depression and QOL. Patients who were younger had worse depression, anxiety, and QOL. The combination of anxiety, depression, age, and time since ICD implant significantly predicted overall QOL and the psychosocial and physical dimensions of QOL explaining 55.5, 54, and 34.9% of the variance, respectively.

CONCLUSION

Younger ICD patients are at highest risk for psychological distress and poor QOL. Longitudinal research would facilitate determination of the trajectory of changes in psychological status and QOL over the duration of the ICD experience.

Health care costs associated with chronic hepatitis B

The long-term health care costs of patients with chronic hepatitis B (CHB) were compared with those of patients without CHB. Patients with laboratory markers for CHB were identified from an HMO database and matched with up to four control patients (either not tested for hepatitis B infection or with negative test results). Cost data were collected retrospectively for both groups of patients for the period up to 30 days before identification of the first marker for hepatitis B (prediagnosis), 30 days before identification of the first marker through 180 days after the identification (peridiagnosis), and 181 days after identification through the end of the six-year study period. Costs were categorized as emergency room, inpatient, short-stay inpatient, laboratory, radiology, office visit, pharmacy, outside claim, or other and were analyzed as ratios of the costs of each patient with CHB to the median of the corresponding control patients. Eighty-eight patients were identified as having CHB; there were 342 control patients. In the seven months surrounding the appearance of their first diagnostic marker, the patients with CHB had costs 3.3 times those of the corresponding control patients and, after the first seven months, 2.9 times those of the control patients per month. Peridiagnosis costs in the categories of laboratory, radiology, office visits, and pharmacy were significantly higher for patients with CHB than for control patients. Except for emergency room costs, postdiagnosis costs per month of the patients with CHB were significantly higher than those of the corresponding control patients. Examination of an HMO database showed that, compared with patients without CHB, patients with CHB had significantly higher health care costs around and after the CHB diagnosis.

Human herpesvirus 6 in lung tissue from patients with pneumonitis after bone marrow transplantation

BACKGROUND

Human herpesvirus 6 (HHV-6) is a recently described herpesvirus that is epidemiologically and biologically similar to cytomegalovirus. It is the cause of exanthem subitum (roseola) in children.

METHODS

To evaluate the possible role of HHV-6 infection in pneumonitis in immunocompromised patients, we used quantitative HHV-6 polymerase chain reactions to study lung-biopsy specimens from 15 patients with pneumonitis after bone marrow transplantation and lung tissue from 15 immunocompetent subjects without pneumonitis and 6 fetuses.

RESULTS

HHV-6 DNA was detected in lung tissue from all 15 patients, from 14 seropositive control subjects, and from none of the 7 seronegative control subjects. Six patients had levels of HHV-6 DNA in lung tissue that were 10 to 500 times higher than those in any of the other patients or control subjects. Increased levels of HHV-6 DNA correlated with a decreased risk of death from pneumonitis (P = 0.015), an increased severity of graft-versus-host disease (P = 0.023), and the presence of idiopathic pneumonitis (P = 0.037). Levels of HHV-6 DNA correlated directly with the changes in HHV-6 antibody titers in the interval between the pretransplantation period and the open-lung biopsy (P = 0.002). Low levels of HHV-6 antibody at the time of the open-lung biopsy were also associated with the diagnosis of idiopathic pneumonitis (P = 0.002).

CONCLUSIONS

The concentrations of HHV-6 genome in lung tissue and their relation to changes in serologic titers support an association between HHV-6 infection and idiopathic pneumonitis in immunocompromised hosts.

The effect of radiation therapy on the fixation strength of an experimental porous-coated implant in dogs

Radiation therapy prevents heterotopic ossification after cemented total hip arthroplasty, but its effect on the fixation of porous-coated devices is not known. The purpose of this study was to determine the effect of irradiation on the pullout strength of a porous implant in the canine model. A custom-designed titanium fiber metal-coated cylinder was implanted into the distal femurs of 12 dogs. One femur of each dog was irradiated with 10 Gy, given in four 2.5-Gy daily fractions beginning one day after surgery. Serial bone scans were performed at one, two, four, and six weeks postoperatively. At six weeks, the femurs were harvested, and eight were randomly selected for mechanical testing. Scintigraphic evaluation showed a significant reduction in uptake at one and two weeks in the irradiated limb, but this had returned to normal at four and six weeks. The failure to pullout was significantly less in the irradiated limb compared with the control limb six weeks postoperatively. In this canine model, the pullout strength of the titanium fiber implant was significantly reduced by a dose of radiation commonly used in the prevention of heterotopic ossification. If irradiation is chosen for prophylaxis, either the porous implant should be adequately shielded or a cemented implant should be utilized.

The diagnostic content of family practice: 50 most common diagnoses recorded in the WAMI community practices

Because there are several methodological deficiencies in previously published studies, a prospective study was carried out of the 50 most common diagnoses of community-based family practices in the Pacific Northwest. Age and sex of patients and reliability of data were controlled. The data reported show reasonable concordance with other published accounts for 10 most common diagnostic categories. For less frequent diagnoses, however, high variability in rank order is the rule, both within this study and by comparison with other studies. This suggests that the diagnostic content of family practice is far from universal and that diagnostic idiosyncrasies of physicians, regional differences in rates of disease, practice style, and as yet other unexplained factors may significantly influence the diagnostic content of family practice.