Activity of moxifloxacin and other quinolones against pneumococci resistant to first-line agents, or with high-level ciprofloxacin resistance

The activity of moxifloxacin and other quinolones was assessed against 288 epidemiologically diverse isolates of Streptococcus pneumoniae, many of them resistant to one or more first-line agents and/or with increased ciprofloxacin resistance (minimum inhibitory concentrations, MICs 16- > 64 mg/l compared with 1-2 mg/l for most isolates). Moxifloxacin and grepafloxacin were the most active quinolone analogues, inhibiting about 90% of the isolates at < or = 1 mg/l, whereas levofloxacin inhibited 64% of isolates at < = 1 mg/l and ciprofloxacin inhibited 42%. Moxifloxacin also was the most active agent against isolates with elevated ciprofloxacin resistance (MIC 16- > 64 mg/l): moxifloxacin MICs of around 4 mg/l were seen for most such isolates, compared with 16-32 mg for levofloxacin and grepafloxacin. The activity of moxifloxacin against pneumococci resistant to one or more first-line agent suggests it will have a useful therapeutic role, although its activity against highly ciprofloxacin resistant isolates seems marginal.

Anomalous viscoelastic response of nematic elastomers

We report a combined theoretical and experimental study of linear viscoelastic response in oriented monodomain nematic elastomers. The model predicts a dramatic decrease in the dynamic modulus in certain deformation geometries in an elastic medium with an independently mobile internal degree of freedom, the nematic director with its own relaxation dynamics. Dynamic mechanical measurements on monodomain nematic elastomers confirm our predictions of dependence on shear geometry and on nematic order, and also show a very substantial mechanical loss clearly associated with director relaxation.

Activity of moxifloxacin against clinical isolates of Streptococcus pneumoniae from England and Wales

The activity of moxifloxacin was assessed against 1269 isolates of Streptococcus pneumoniae, comprising 462 isolates referred from UK hospitals, primarily for confirmation of resistance to first line agents, and 807 isolates from an enhanced surveillance of invasive infections. Resistance rates to penicillin, erythromycin, tetracycline and chloramphenicol were 88.7% (32.6% intermediate and 56.1% fully resistant), 50, 48 and 22.7%, respectively, for the former, and 8.0 (4.5% intermediate and 3.5% fully resistant), 14.7, 9.0 and 0.6% for the latter. Ninety-four per cent of the referred isolates and 99% of the surveillance isolates were susceptible to moxifloxacin at <or=1 mg/L. Moxifloxacin may therefore be a useful drug for the treatment of patients with pneumococcal infections due to antibiotic-resistant strains or those with severe invasive disease.

Signalling pathways regulating the dephosphorylation of Ser729 in the hydrophobic domain of protein kinase Cepsilon upon cell passage

We have recently demonstrated that in quiescent fibroblasts protein kinase C (PKC) epsilon(95) is phosphorylated at Ser(729), Ser(703), and Thr(566) and that upon passage of quiescent cells phosphorylation at Ser(729) is lost, giving rise to PKCepsilon(87). Ser(729) may be rephosphorylated later, suggesting cycling between PKCepsilon(87) and PKCepsilon(95). Here we show that the dephosphorylation at Ser(729) is insensitive to okadaic acid, calyculin, ascomycin C, and cyclosporin A, suggesting that dephosphorylation at this site is not mediated through protein phosphatases 1, 2A or 2B. We demonstrate that this dephosphorylation at Ser(729) requires serum and cell readhesion and is sensitive to rapamycin, PD98059, chelerythrine, and Ro-31-8220. These results suggest that the phosphorylation status of Ser(729) in the hydrophobic domain at Ser(729) is regulated independently of the phosphorylation status of other sites in PKCepsilon, by a mTOR-sensitive phosphatase. The mitogen-activated protein kinase pathway and PKC are also implicated in regulating the dephosphorylation at Ser(729).

Mechanism of oestrogen signalling with particular reference to the role of ER beta in the central nervous system

The discovery of a second oestrogen receptor (ER), ER beta, has drastically changed our view of oestrogen action. Since the two ERs, ER alpha and ER beta, have somewhat different tissue and cellular distribution as well as ligand binding specificity the possibility exists that they have different biological roles. Indeed, several observations seem to indicate that they may even have opposite effects so that ER beta diminishes the activity of ER alpha. The CNS contains both ER alpha and ER beta and it is conceivable that they may have specific and individual roles in oestrogen signalling in the brain.

Morphological abnormalities in the brains of estrogen receptor beta knockout mice

Estrogen receptor beta (ERbeta) is expressed at high levels in both neurons and glial cells of the central nervous system. The development of ERbeta knockout (BERKO) mice has provided a model to study the function of this nuclear receptor in the brain. We have found that the brains of BERKO mice show several morphological abnormalities. There is a regional neuronal hypocellularity in the brain, with a severe neuronal deficit in the somatosensory cortex, especially layers II, III, IV, and V, and a remarkable proliferation of astroglial cells in the limbic system but not in the cortex. These abnormalities are evident as early as 2 mo of age in BERKO mice. As BERKO mice age, the neuronal deficit becomes more pronounced, and, by 2 yr of age, there is degeneration of neuronal cell bodies throughout the brain. This is particularly evident in the substantia nigra. We conclude that ERbeta is necessary for neuronal survival and speculate that this gene could have an important influence on the development of degenerative diseases of the central nervous system, such as Alzheimer's disease and Parkinson's disease, as well as those resulting from trauma and stroke in the brain.

In vitro activity of ketolides HMR 3004 and HMR 3647 and seven other antimicrobial agents against Corynebacterium diphtheriae

The in vitro activities of two ketolides, HMR 3004 and HMR 3647 (telithromycin), and the comparator agents erythromycin A, azithromycin, clarithromycin, roxithromycin, levofloxacin, ofloxacin and penicillin G were determined by an agar dilution method against 410 isolates of Corynebacterium diphtheriae. Test isolates originated from diverse geographical locations, including the former USSR, where epidemic diphtheria has re-emerged during the 1990s. All isolates tested were susceptible to penicillin G, ofloxacin and levofloxacin. The two ketolides and four macrolides were highly active against 405 of the 410 isolates. HMR 3004 was the most active of the drugs, followed by HMR 3647, clarithromycin, erythromycin A, roxithromycin and azithromycin. Five isolates showed reduced susceptibility to all macrolides and ketolides tested; three were non-toxigenic isolates from Australia and the remaining two were from cases of diphtheria in Vietnam. Inducible (MLS(B)) resistance was detected in the isolates from Vietnam, but not in the isolates originating from Australia. Significant antimicrobial resistance remains rare amongst C. diphtheriae; nevertheless, new ketolide antimicrobials may have a role to play in the treatment and control of this re-emergent pathogen.

Susceptibility of gram-positive cocci from 25 UK hospitals to antimicrobial agents including linezolid. The Linezolid Study Group

The prevalence of antibiotic resistance amongst Gram-positive cocci from 25 UK hospitals was studied over an 8 month period in 1999. A total of 3770 isolates were tested by the sentinel laboratories using the Etest; these bacteria comprised 1000 pneumococci, 1005 Staphylococcus aureus, 769 coagulase-negative staphylococci (CNS) and 996 enterococci. To ensure quality, 10% of the isolates were retested centrally, as were any found to express unusual resistance patterns. The prevalence of penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci and methicillin-resistant S. aureus (MRSA) varied widely amongst the sentinel laboratories. The resistance rates to methicillin among S. aureus and CNS were 19.2 and 38.9%, respectively, with MRSA rates in individual sentinel sites ranging from 0 to 43%. No glycopeptide resistance was seen in S. aureus, but 6.5% of CNS isolates were teicoplanin resistant and 0.5% were vancomycin resistant. Vancomycin resistance was much more frequent among Enterococcus faecium (24.1%) than E. faecalis (0.5%) (P<0.05), with most resistant isolates carrying vanA. The rate of penicillin resistance in pneumococci was 8.9%, and this resistance was predominantly intermediate (7.9%), with only six hospitals reporting isolates with high level resistance. The prevalence of erythromycin resistance among pneumococci was 12.3%, with the majority of resistant isolates having the macrolide efflux mechanism mediated by mefE. All the organisms tested were susceptible to linezolid with MICs in the range 0.12-4 mg/L. The modal MICs of linezolid were 1 mg/L for CNS and pneumococci, and 2 mg/L for S. aureus and enterococci. Linezolid was the most potent agent tested against Gram-positive cocci, including multiresistant strains, and as such may prove a valuable therapeutic option for the management of Gram-positive infections in hospitals.

Obesity and disturbed lipoprotein profile in estrogen receptor-alpha-deficient male mice

Clinical case reports have documented disturbances of carbohydrate and lipid metabolism in aromatase deficient and estrogen resistant males. The aim of the present study was to explore the metabolic functions of estrogens in male mice and to dissect the estrogen receptor (ER) specificity of such effects. Total body fat content and serum levels of leptin were followed in ERalpha knockout (ERKO), ERbeta knockout (BERKO), and ERalpha/beta double knockout (DERKO) mice. Neither the total body fat nor serum leptin levels were altered in any group before or during sexual maturation. However, after sexual maturation ERKO and DERKO, but not BERKO, demonstrated a clear increase in total body fat and enhanced serum leptin levels. Serum cholesterol was increased and a qualitative change in the lipoprotein profile, including smaller LDL particles, was observed in ERKO and DERKO mice. In conclusion, ERalpha but not ERbeta-inactivated male mice develop obesity after sexual maturation.

Estrogen receptor beta in the breast: role in estrogen responsiveness and development of breast cancer

Breast cancer is one of the most common forms of cancer observed in women. Endogenous estrogen is thought to play a major role in its development and estrogen receptor blockers are the most important drugs in its treatment. It has long been thought that any conditions or exposures, which enhance estrogenic responses, would result in an increased risk for breast cancer. The discovery of the second estrogen receptor, ERbeta, which can have effects opposite to those of the well-known 'original' estrogen receptor (now called ERalpha) challenges this simplistic view. In order to understand breast cancer one must first understand how the normal breast is maintained. The functions of ERbeta in the breast remain to be defined but from what we have learnt about its activities in in vitro systems, this estrogen receptor may have a protective role in the breast. Studies in human and rodent breasts as well as in human breast cancer biopsies reveal that ERbeta is by far the more abundant of the two ERs. Despite the role of estrogen in proliferation of the breast, neither of the two ERs appears to located in epithelial cells which divide in response to estrogen. In order to define the functions of ERbeta in the normal and malignant breast, we have created mice in which the ERbeta gene has been inactivated. Studies of the breasts of ERbeta knock out mice (BERKO) revealed abnormal epithelial growth, overexpression of Ki67 and severe cystic breast disease as mice age.

Detection of extended-spectrum beta-lactamases in klebsiellae with the Oxoid combination disk method

The Oxoid combination disk method for detecting extended-spectrum beta-lactamases (ESBLs) depends on comparing the inhibition zones of cefpodoxime (10-microg) and cefpodoxime-plus-clavulanate (10- plus 1-microg) disks. The presence of clavulanate enlarged the zones for all of 180 ESBL-producing klebsiellae by >/=5 mm, whereas zones for cefpodoxime-susceptible isolates and cefpodoxime-resistant isolates with AmpC and K1 beta-lactamases were enlarged by Collapse

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MESH Headings

• Bacterial Proteins
• Ceftazidime/pharmacology
• Ceftizoxime/analogs & derivatives
• Ceftizoxime/pharmacology
• Cephalosporins/pharmacology
• Clavulanic Acid/pharmacology
• Humans
• Klebsiella/drug effects
• Klebsiella/enzymology
• Klebsiella Infections/microbiology
• Klebsiella pneumoniae/drug effects
• Klebsiella pneumoniae/enzymology
• Microbial Sensitivity Tests/methods
• beta-Lactamases/metabolism
• Cefpodoxime

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Grants Collapse

Untwisting of a cholesteric elastomer by a mechanical field

A mechanical strain field applied to a monodomain cholesteric elastomer will unwind the helical director distribution. There are similarities with the classical problem of an electric field applied to a cholesteric liquid crystal but also differences. Frank elasticity is of minor importance unless the gel is very weak. The interplay is between the director being helically anchored to the rubber elastic matrix and the external mechanical field. Stretching perpendicular to the helix axis induces the uniform unwound state via the elimination of sharp, pinned twist walls above a critical strain. Unwinding through conical director states occurs when the elastomer is stretched along the helical axis.

Director rotation via photoinduced differential depletion in nematic dyes

We revisit the problem of director realignment induced by photoisomerization of rodlike dye molecules. We find a geometrical basis for the rotational rate, arising by the differential depletion of rods from the nematic distribution. A simple expression, valid for arbitrarily strong, Maier-Saupe-like nematic order, is given for this rate. Contact is made with the weak order scaling limit given in the literature.

Drowning and alcohol in New Zealand: what do the coroner's files tell us?

OBJECTIVE

To provide a systematic review of the details on alcohol involvement available in the coronial files to determine if there is enough evidence to estimate the role of alcohol in drowning.

METHOD

We reviewed the coroner's files of persons 10 years or older who drowned in New Zealand between 1992-1994 inclusive.

RESULTS

A total of 320 coroner's files were examined. Blood Alcohol Concentrations (BACs) were taken in 115 cases (36%) and positive for 50% of these. When accounting for the incomplete testing by using all the information on alcohol involvement collected, between 30-40% of the cases were estimated to have a positive BAC and between 17-24% to have a BAC 100 mg/dL or higher.

CONCLUSION

The quality and completeness of current coronial information on alcohol involvement in drowning is insufficient to arrive at an accurate estimate of the percentage of drownings where alcohol was a factor.

IMPLICATIONS

Coroners should test drowning victims 10 years and older for BAC. These data should be systematically recorded and processed with the goal of determining who should be targeted in drowning and alcohol prevention programs.

The normal and malignant mammary gland: a fresh look with ER beta onboard

Estrogens are important for the development and function of the normal mammary gland as well as for development of mammary cancer. The frontline therapy for treatment of estrogen receptor (ER alpha) positive breast cancer is antiestrogens. A second estrogen receptor (ER beta) is also expressed in the breast but it has not been measured because it is not detected by the immunoassays used to detect ER alpha. In many cell systems ER beta has actions which are opposite to those of ER alpha and this finding has raised questions about the role of ER beta in the development and treatment of breast cancer.

Susceptibility to quinupristin/dalfopristin and other antibiotics of vancomycin-resistant enterococci from the UK, 1997 to mid-1999

Susceptibility to quinupristin/dalfopristin and other antibiotics was studied for clinical isolates of vancomycin-resistant enterococci (VRE) referred by UK hospitals between January 1997 and June 1999. Single isolates of VRE from 858 patients in 136 hospitals were received, of which 76% were Enterococcus faecium and 21% were Enterococcus faecalis, the remainder comprising minor species. Most isolates were multi-resistant. After allowing for the effect of blood, which raised the MICs of quinupristin/dalfopristin four-fold, 98.3% of E. faecalis isolates and all the Enterococcus avium, Enterococcus casseliflavus and Enterococcus gallinarum appeared resistant to quinupristin/dalfopristin, whereas 98.8% of the E. faecium isolates and the single Enterococcus raffinosus isolate were susceptible.

Injury and poisoning episodes and conditions: National Health Interview Survey, 1997

OBJECTIVE

This report provides a descriptive overview of the first year of data from the injury section of the redesigned National Health Interview Survey. It documents the Survey's design methodologies and presents detailed national estimates of nonfatal injury and poisoning episodes for 1997.

METHODS

Data for the U.S. civilian noninstitutionalized population were collected using Computer Assisted Personal Interview (CAPI). The data on all medically attended injuries and poisonings occurring to any family member during the 3-month period prior to the interview were obtained from an adult member of the family.

RESULTS

In 1997, 34.4 million medically-attended episodes of injury and poisoning were reported, resulting in an age-adjusted rate of 128.9 episodes per 1000 persons. Injury episodes resulted in 40.9 million injury conditions for a rate of 153.7 conditions per 1,000 persons. Falls were the leading external cause of injury, followed by episodes resulting from being struck by or against a person or an object, transportation, overexertion, cutting and piercing instruments, and poisoning. Sprains and strains were the most frequently reported injury condition followed by open wounds, fractures, and contusions. Upper extremity and lower extremity injuries were the leading body regions for these conditions. Leisure activities and paid work were most often reported as the activities the person was engaged in when the injury episode occurred, and. the home was the most likely place for the injury to have occurred.

CONCLUSION

The redesigned NHIS is a useful source of information about medically-attended nonfatal injuries and poisonings. A single year now provides enough data to produce stable national estimates on details of injury and poisoning episodes.

Theory of chiral imprinting

We present a continuum model for a nematic elastomer network formed in a chiral environment, for instance, in the presence of a chiral solvent. When this environment is removed, the network can retain some memory of its chiral genesis. We predict the residual chiral order for a number of possible scenarios, and examine the robustness (stability) of the imprinted chirality. We show that a twist-untwist transition can take place, which determines whether the imprinting has been successful. A transition is via a coarsening of the helical director pattern and a lengthening of its pitch. Finally, the effect due to a subsequent swelling by an achiral solvent, or by a solvent of differing chirality, is considered.