Plasma observations during the Mars atmospheric "plume" event of March-April 2012

We present initial analysis and conclusions from plasma observations made during the reported "Mars plume event" of March - April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator [Sanchez-Lavega et al., Nature, 2015, doi:10.1038/nature14162], the cause of which remains to be explained. The estimated brightness of the plume exceeds that expected for auroral emissions, and its projected altitude greatly exceeds that at which clouds are expected to form. We report on in-situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the same surface region, but at the opposing terminator. Measurements in the ionosphere at the corresponding location frequently show a disturbed structure, though this is not atypical for such regions with intense crustal magnetic fields. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part to the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that the only similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.

Radar soundings of the ionosphere of Mars

We report the first radar soundings of the ionosphere of Mars with the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on board the orbiting Mars Express spacecraft. Several types of ionospheric echoes are observed, ranging from vertical echoes caused by specular reflection from the horizontally stratified ionosphere to a wide variety of oblique and diffuse echoes. The oblique echoes are believed to arise mainly from ionospheric structures associated with the complex crustal magnetic fields of Mars. Echoes at the electron plasma frequency and the cyclotron period also provide measurements of the local electron density and magnetic field strength.

Rapid fingerprinting of Helicobacter pylori by polymerase chain reaction and restriction fragment length polymorphism analysis

A simple and reliable technique was developed for differentiating Helicobacter pylori strains by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified DNAs. Oligonucleotide primer pairs developed to the urease, 48-kDa stress protein (htrA), and 26-kDa antigen-encoding genes were used to amplify fragments of the appropriate size from crude boiled cell preparations. The PCR-amplified products were digested with Sau3A, HaeIII, MspI, AluI, MluI, HinfI, and XbaI restriction endonucleases. Restriction fragment length polymorphisms were particularly evident within the urease and htrA genes and were easily detected by Sau3A, HaeIII, MspI, and AluI restriction endonuclease analysis. Double digestion of these separately amplified products or restriction analysis of multiple PCR-amplified fragments was found to discriminate 17 of 17 (100%) H. pylori strains which had unique genomic DNA fingerprints. Results of an investigation of multiple isolate sets obtained from patients before and after therapy was consistent with the hypothesis that treatment failures were due to the persistence of the same strain but did not discount the possibility that the patients were reinfected with a strain shared by family members or close contacts. The results indicate that the PCR-restriction endonuclease analysis method can be applied directly to biopsy samples, has the potential to fingerprint H. pylori isolates rapidly, and may permit detailed epidemiological investigations on the transmission of this important pathogen.

Sensitive detection of Helicobacter pylori by using polymerase chain reaction

A polymerase chain reaction (PCR) for the specific detection of Helicobacter pylori was developed with a single primer pair derived from the nucleotide sequence of the urease A gene of H. pylori. We achieved specific amplification of a 411-bp DNA fragment in H. pylori. After 35 cycles of amplification, the product could be detected by agarose gel electrophoresis and contained conserved single HinfI and AluI restriction sites. This fragment was amplified in all 50 strains of H. pylori tested, but it was not detected in other bacterial species, showing the PCR assay to be 100% specific. PCR DNA amplification was able to detect as few as 10 H. pylori cells. PCR detected H. pylori in 15 of 23 clinical human gastric biopsy samples, whereas culturing and microscopy detected H. pylori in only 7 of the samples found to be positive by PCR. Additional primer pairs based on the urease genes enabled the detection of H. pylori in paraffin-embedded human gastric biopsy samples. The detection of H. pylori by PCR will enable both retrospective and prospective analyses of clinical samples, elucidating the role of this organism in gastroduodenal disease.

Differentiation of strains of Helicobacter pylori by numerical analysis of 1-D SDS-PAGE protein patterns: evidence for post-treatment recrudescence

Twenty-three pre- and post-treatment isolates of Helicobacter pylori from the antral mucosa of eight patients with dyspepsia and gastritis were compared using 1-D SDS PAGE of proteins. The protein patterns were highly reproducible and were used as the basis for two numerical analyses. The first, based on the total protein patterns, showed that a number of the strains did not cluster with their respective patient set. This was thought to be due to differences in both mobility and intensity of proteins in the major band region. The second analysis, based on partial patterns, excluding the major band region (51-68 kDa), divided the clinical isolates into clearly defined groups corresponding to the patient sets. Although there was a degree of heterogeneity with respect to protein pattern between the pre- and post-treatment isolates of some patients, there was nonetheless clear evidence that each patient was harbouring strains of only a single type. These results suggested that patients were not being reinfected with a different strain but that there was recrudescence of the pre-treatment strain. Protein 'fingerprints' provided a precise and reproducible means of strain differentiation, and revealed that in each patient the same strain persisted after drug therapy even though there was marked patient-to-patient strain variation.

Differentiation of Achromobacter-like strains from human blood by DNA restriction endonuclease digest and ribosomal RNA gene probe patterns

Variation amongst Achromobacter-like strains was examined by DNA restriction endonuclease digestion and rDNA gene patterns generated using a non-radioactive probe. Chromosomal DNA was extracted from 12 cultures representing Achromobacter groups B, E and F, all from human blood cultures. DNA fingerprinting using EcoRI, Hae III or HindIII sub-divided the strains in a similar manner to that obtained by their protein patterns. The HaeIII patterns, with their small number of bands, were the easiest to interpret. The EcoRI patterns included a species-species triplet of bands but minor band patterns allowed further differentiation. The Achromobacter group F strains comprised a separate taxon and were distinct from the group B and E strains by all techniques examined. The study demonstrates that, in addition to total DNA digest analysis, rDNA gene restriction patterns provide a simple but discriminatory electrophoretic method for distinguishing within Achromobacter groups B and E.

Use of DNA restriction endonuclease digest and ribosomal RNA gene probe patterns to fingerprint Helicobacter pylori and Helicobacter mustelae isolated from human and animal hosts

Variation amongst strains of Helicobacter pylori and Helicobacter mustelae was examined by DNA restriction endonuclease digestion and rRNA gene patterns generated using a non-radioactive probe. Chromosomal DNA was extracted from 30 cultures of H. pylori from human, Rhesus monkey and pig gastric mucosa, and from three H. mustelae isolates from ferret gastric mucosa. DNA fingerprinting with Hae III and Hind III showed H. mustelae was relatively homogeneous but revealed genomic heterogeneity within H. pylori with at least 18 different DNA patterns identifiable amongst the 30 isolates. Five sets of strains other than duplicates with matching DNA fingerprints were identified within H. pylori. The Peruvian isolates were the largest identical set and comprised eight isolates from four different patients with five consecutive isolates from one patient. The Rhesus monkey strains were a relatively homogeneous set as were several Australian human isolates. The study demonstrates that rRNA gene restriction patterns provide a simple but highly discriminatory electrophoretic fingerprint for H. pylori with potential for use as a novel epidemiological marker in addition to total DNA digest analysis.

Potential effectiveness of comparative casemix-corrected adverse outcome rates as quality monitors in a simulated hospital system

To facilitate outcome-based medical quality assurance, a screening technique was developed which corrected facility-specific data for casemix using mean outcome rates from pooled data to establish norms for "uniform-risk groups" of patients. A stimulated health care system (108 facilities treating over 500,000 annually) was created to evaluate this technique's ability to distinguish between systems whose adverse outcomes were determined solely by casemix and random variations and those with true differences in quality of care. Specificity and sensitivity of quality of care decisions for individual facilities also were assessed. The screening technique achieved excellent differentiation between "homogeneous" systems and those with facility-specific variations in quality of care. No more than 3% of facilities without quality of care problems were ever inaccurately labeled, unless systematic or random errors in patient risk classification were introduced. Sensitivity in detecting substandard facilities was 35% when true deviation from standard was 2.5%, and rose to virtually 100% when deviation was 25% or greater. Thus, simulation can serve as an efficient method of testing the potential performance of casemix-corrected quality assurance screening under a wide variety of circumstances.

Identification of 'Campylobacter upsaliensis' and other catalase-negative campylobacters from paediatric blood cultures by numerical analysis of electrophoretic protein patterns

Twenty-one strains of catalase-negative campylobacters from paediatric blood cultures were characterized by one-dimensional SDS-PAGE of cellular proteins. A further 11 Campylobacter strains were included for reference purposes. The partial protein patterns were used as the basis of a numerical analysis, which showed that 17 hippurate-negative strains had a high similarity to 'C. upsaliensis' (r greater than or equal to 0.82) irrespective of their geographical location, and that three hippurate-positive isolates had a high similarity (r greater than or equal to 0.87) to C. jejuni subsp. jejuni. One hippurate-positive CNW strain was not identified. The analysis of SDS-PAGE protein patterns proved an excellent method of characterizing these thermophilic campylobacter as they were difficult to identify by traditional methods.

Strain variation in Campylobacter pylori detected by numerical analysis of one-dimensional electrophoretic protein patterns

A total of 21 clinical isolates of Campylobacter pylori from Peru and the United Kingdom and two reference strains (from Australia), including the type strain (NCTC 11637T), were characterized by high resolution one-dimensional SDS-polyacrylamide gel electrophoresis of cellular proteins. The protein patterns contained more than 40 discrete bands and the approximate molecular weights of the major bands were 22, 27, 46, 57, 60, 65 and 93 kD. The total patterns were used as the basis of numerical analysis. Most strains were clustered in four phenons at 91% similarity with the exception of six ungrouped strains. Overall similarity was high with all strains linked in the phenogram at greater than or equal to 81%. Variation among strains was attributable principally to qualitative and quantitative band differences in the 47 to 56 kD (hypervariable) region of the C. pylori protein profile. From the analysis, ten different electropherotypes (EP-types) were identified. We demonstrated that differences were detectable among isolates from widely separated geographical locations as well as from the same location, although multiple isolates from two Peruvian patients had the same electropherotype. Our results indicate that determination of protein profiles provides the basis of a reproducible method for characterization of C. pylori isolates.

Hepatitis B vaccination. Response of alcoholic with and without liver injury

Alcoholics are at risk to develop hepatitis B infections, chronic active hepatitis, and even hepatoma. Hence, immunization with hepatitis B vaccine is recommended. However, immune abnormalities may coexist which alter their responsiveness to vaccination. This study compares the immune response to this vaccine in controls (group I), alcoholics without overt liver disease (group II), and alcoholics with clinical liver disease (group III). By the seventh month after the initial vaccination, 89% in group I, 70% in group II, and 18% in group III had a response greater than 36 RIA units. The magnitude of the response was significantly different in groups I, II, and III (19,456 vs 8,326 vs 153 RIA units, respectively; P less than 0.05, group I vs III). In those who did not respond, a significant (P less than 0.02) lower helper/inducer (T4) class of lymphocytes was observed as compared to patients who exhibited an adequate response. These observations suggest: (1) that the response to hepatitis B vaccine is a T-cell-dependent event and (2) that in this population, using the existing vaccine, postvaccination evaluations of antibody concentrations are needed before protection against hepatitis B infection can be assumed.

The changing pattern of alcohol consumption in England and Wales 1978-85

An alcohol consumption survey of 926 people aged 18 or over in England and Wales was conducted by Gallup in 1985. The results were compared with those obtained in a similar survey conducted by the Office of Population Censuses and Surveys in 1978. Overall alcohol consumption remained virtually unchanged. Men showed little difference in drinking habits, except for the 18-24 age group, who seemed to be drinking less. For women mean alcohol consumption in 1985 was similar to that in 1978, but more women were not drinking at all so the mean alcohol consumption per drinker had risen. As with earlier work, this study showed that social class had little influence on alcohol consumption, while being married seemed to have a moderating effect. A variable regional pattern of alcohol intake was found. In a separate analysis under-age drinking was common among 16-17 year olds (65%). Their pattern of drinking was similar to that of other age groups, except for those over 65 years, who drank less. Change in alcohol intake in the UK over the seven years was in the middle of the range of values for other European countries. The stable UK overall consumption was perhaps due to the constant relative price of alcohol.

The pharmacokinetics of benzo[alpha]pyrene in the isolated perfused rabbit lung: the influence of benzo[alpha]pyrene, n-dodecane, particulate, or sulfur dioxide

The pharmacokinetics of benzo[a]pyrene (BaP) in the isolated perfused rabbit lung (IPL) following pretreatment of the whole animal or simultaneous administration to the IPL with n-dodecane, ferric oxide, crude airborne particulate (CAP), fly ash or sulfur dioxide have been investigated using a one compartment model. The rate constant for the appearance (ka) of BaP in the blood, the clearance of BaP from the blood, and the rate of appearance of BaP metabolites (RAM) were the kinetic parameters determined. BaP entered the blood rapidly with an average half-life of 11 min in experiments in which the IPLs received only BaP on perfusion. The logarithms of the clearances from these experiments were linearly correlated with the RAMs. In these experiments, pretreatment of the whole animal with BaP produced a 48-55-fold increase in BaP clearance while pretreatment with n-dodecane increased the clearance 4-fold in comparison with no pretreatment. Pretreatment with ferric oxide or ferric oxide and BaP increased the clearance by factors of 5.5 and 1.5, respectively, over those of unpretreated and BaP pretreated experiments.

Analysis and properties of the cytosolic estrogen receptor from rat thymus

The equilibrium association constant, KA, and the number of receptor binding sites, Bmax, that characterize the estrogen receptor present in rat thymus were determined using five different methods of data analysis on binding data obtained using a dextran-coated-charcoal assay. The methods of data analysis consisted of fitting the binding data directly to the hyperbolic binding function, fitting the data to the Lineweaver-Burk, Scatchard, and Woolf transforms of the hyperbolic function, and the direct linear plot method of Eisenthal--Cornish-Bowden. The Woolf and Eisenthal--Cornish-Bowden methods gave identical results indicating that added estradiol caused a decrease in KA (competitive inhibition) and a marked decrease in Bmax (noncompetitive inhibition). The Scatchard analyses gave only a very qualitative indication of this trend, while the Lineweaver-Burk analyses gave no indication of any such systematic trend. The results from the computationally more difficult fits to the hyperbolic binding equation were in agreement with the Woolf and Eisenthal--Cornish-Bowden results. Thus, the cytosolic thymus estrogen receptor from the rat shows both competitive and noncompetitive inhibition in the presence of endogenous or exogenous estradiol.

The absorption of intramuscular chlordiazepoxide (Librium) in patients with severe alcoholic liver disease

Intramuscular chlordiazepoxide (CDX) is commonly administered to alcoholic liver disease (ALD) patients requiring prompt management of alcohol agitation, anxiety, and delirium tremors. Sedative action is associated with plasma levels of approximately 2.0 mcg/ml, however, intramuscular CDX has been shown to produce peak concentrations consistently below 2.0 mcg/ml in normal subjects. The present study was designed to define the absorption characteristics of intramuscular 25 mg CDX in males with ALD. Five normal males had mean CDX absorption half-lives of 3.0 h and peaked at 0.8 mcg/ml in 7.2 h, while 11 males with ALD had mean absorption half-lives of 9.0 h, and peaked at 0.7 mcg/ml in 19.1 h when they received the drug dissolved in normal saline. Four other males with ALD who received CDX dissolved in the manufacturer's diluent had significantly slower mean absorption half-lives of 16.1 h which peaked at 0.3 mcg/ml in 35.2 h. Significant linear correlations were found with age (r = 0.60, p less than 0.01), body weight (r = 0.55, p less than 0.01), and serum albumin (r = 0.60, p less than 0.01). Because of the extremely slow intramuscular absorption of CDX dissolved in normal saline or the manufacturer's diluent in males with ALD, we do not recommend this route of administration in this population.

Clinical pharmacokinetics of chlordiazepoxide in patients with alcoholic hepatitis

The clearance of chlordiazepoxide from the systemic circulation was studied in 20 subjects which included 15 patients with alcoholic hepatitis and 5 normal volunteers. The half-life for the appearance of the drug in the systemic circulation was found to increase exponentially with age (r = 0.73, P less than 0.0005) and was independent of the presence of alcoholic hepatitis. The metabolic clearance of chlordiazepoxide was significantly lower in the patients than in the normal subjects (7.6 compared to 13.8 ml/kg-h, P less than 0.005). Linear regression analysis revealed a significant correlation between clearance and albumin (r = 0.77, P less than 0.00005). However, the predictive value of this relationship was shown to be minimal. Multiple regression analysis produced only a slight improvement in the correlation when both albumin and lactate dehydrogenase were used as variables (r = 0.83, P less than 0.00005). In six of the patients, a second clearance study was conducted three weeks following their initial one. All repeat subjects showed improvement both clinically and as reflected by their laboratory tests for liver injury, but there was not a significant change in their clearance of chlordiazepoxide. Multiple regression analysis of the clearance data on the initial and repeat subjects showed a significant correlation between clearance and the variables age, albumin and lactate dehydrogenase (r = 0.91, P less than 0.0025). This relationship suggests that over a short period of time (where age can be considered constant) changes in albumin and lactate dehydrogenase could be potentially useful in predicting clearance changes in a single individual.

Serum alpha-fetoprotein: changes associated with acute and chronic ethanol ingestion in the resting and regenerating rat liver

The effect of acute and chronic ethanol consumption on serum alpha-fetoprotein was studied in adult male rats with resting and regenerating livers. Unlike many hepatotoxins, ethanol consumed over both the long and short term suppressed serum alpha-fetoprotein concentrations (p less than 0.05). This suppression was not due to increased degradation, since the half-life of alpha-fetoprotein was not significantly altered by chronic ethanol treatment. However, liver cytosolic alpha-fetoprotein was markedly increased after ethanol consumption, suggesting the presence of impaired secretion or mobilization from the liver cells. During liver regeneration following partial hepatectomy, alpha-fetoprotein increased in both the control (390 ng-hr/ml) and ethanol-treated animals (288 ng-hr/ml). At no time did the ethanol animal values equal the control levels. The change in serum alpha-fetoprotein showed an inverse exponential correlation with the amount of liver removed at hepatectomy and a positive correlation with the amount of nuclear DNA present at sacrifice. However, in the ethanol-treated animals it required the removal of 1.9 times as much liver to stimulate the same degree of liver regeneration as in the controls (p less than 0.001). A significant inverse correlation was observed between 3H-thymidine uptake and the areas under the alpha-fetoprotein time curves in the controls (p less than 0.001). In the ethanol groups the correlation was not statistically significant (p less than 0.2). It is concluded that although changes in serum alpha-fetoprotein may be associated with liver injury and regeneration, they are not a direct result of the regenerative process. The direct correlation with available nuclear DNA indicates the need for existing cells to hypertrophy and produce the alpha-fetoprotein. The depression associated with acute and chronic ethanol ingestion appears to reflect a direct effect of ethanol on protein synthesis and/or release.

Demonstration of a deoxycytidine kinase activity in extracts of Bacillus megaterium KM

Extracts of Bacillus megaterium KM have been shown to possess a deoxycytidine kinase activity which functions optimally with guanosine triphosphate as the phosphoryl donor.

Deoxynucleoside kinases of Bacillus megaterium KM

Dialyzed extracts of Bacillus megaterium KM contain thymidine, deoxyadenosine, and deoxyguanosine kinase activities. Thymidine kinase activity is best with deoxyadenosine triphosphate or deoxyguanosine triphosphate (dGTP) as the phosphoryl donor, whereas the best deoxyadenosine kinase activity is obtained with dGTP or adenosine triphosphate. Deoxyguanosine kinase activity functions optimally with deoxycytidine triphosphate as the donor. Although the thymidine kinase activity of crude extracts does not have a demonstrable divalent cation requirement, the addition of Mg(2+) or Mn(2+) is necessary for the formation of thymidine di- and triphosphates. The synthesis of thymidine kinase appears to be partially derepressed by thymine starvation. Incubation of extracts with deoxyadenosine and dGTP results in the substantial accumulation of deoxyadenosine di- and triphosphates. Extracts deaminate deoxycytidine to deoxyuridine, presumably as a consequence of the action of deoxycytidine deaminase, and then convert deoxyuridine to deoxyuridylic acid. B. megaterium extracts do not contain any detectable deoxycytidine kinase activity.