Mungbean: a nickel indicator, accumulator or excluder?

Seeds of the two mungbean cultivars were exposed to 25, 30, 35 and 40 mg L(-1) nickel along with control. Nickel stress decreased growth, photosynthetic pigments, yield attributes and cation (Na(+), K(+) and Ca(2+)) accumulation in mungbean. This reduction was less at 25 mg L(-1) as compared to 40 mg L(-1) nickel. In addition, nickel was mainly stored in roots and restricted transfer to the aerial parts (shoot and least by leaves) was observed.

Secondary hypertrophic osteoarthropathy: new insights on pathogenesis and management

Hypertrophic osteoarthropathy is a syndrome that includes finger clubbing, periostitis with new subperiosteal bone formation of long bones and arthritis. It is often related to an intrathoracic neoplasms or chronic infections; hence called hypertrophic pulmonary osteoarthropathy. A primary or idiopathic form, also known as Pachydermoperiostosis, also exist. It is commonly seen in children and young adults and has not been found associated with underlying disease. Platelet derived growth factors has been recently recognized to have a key role in the pathogenesis of this disorder. Hypertrophic osteoarthropathy may cause disabling symptoms. Cure of neoplasia may result in regression of the hypertrophic osteoarthropathy.

A genotype-independent real-time PCR assay for quantification of hepatitis B virus DNA

Accurate quantification of hepatitis B virus (HBV) DNA levels is important for monitoring patients with chronic HBV infection and for assessing their responses to antiviral therapy. This study aimed to develop a real-time PCR assay that is sensitive and can accurately quantify a wide range of HBV DNA levels across the known HBV genotypes. An "in-house" real-time PCR assay using primers and a TaqMan probe in a highly conserved region of the HBV surface gene was designed. The assay was standardized against a WHO standard and validated against plasmids of HBV genotypes A through H. The linear quantification range was approximately 5 x 10(0) to 2.0 x 10(9) IU/ml. Results of samples from patients infected with HBV genotypes A through H tested using our real-time "in-house" PCR assay showed an excellent correlation with those of the Cobas Amplicor HBV Monitor (R2=0.9435) and the Cobas TaqMan HBV (R2=0.9873) tests. We have established a real-time PCR assay that is genotype independent and can accurately quantify a wide range of HBV DNA levels. Further studies of additional samples are ongoing to validate the genotype independence of our assay.

Evolution of multi-drug resistant hepatitis B virus during sequential therapy

Multi-drug resistant hepatitis B virus (HBV) has been reported in hepatitis B patients who received sequential antiviral therapy. In vitro studies showed that HBV constructs with mutations resistant to lamivudine and adefovir have marked reduction in sensitivity to combination of lamivudine and adefovir, whereas constructs with mutations resistant to either drug remain sensitive to the other drug. We conducted this study to determine whether mutations conferring resistance to multiple antiviral agents co-locate on the same HBV genome in vivo and to describe the evolution of these mutations. Sera from six patients who had been found to have multi-drug resistant HBV mutations to lamivudine+adefovir, lamivudine+hepatitis B immunoglobulin (HBIG), or lamivudine+entecavir on direct sequencing were cloned after nested polymerase chain reaction (PCR). Analysis of 215 clones from 11 samples with multi-drug resistant mutations on direct sequencing showed that 183 (85%) clones had mutations to both therapies on the same genome; 31 clones had lamivudine-resistant mutants only. Clonal analysis of serial samples from three patients showed progressive evolution from all clones with lamivudine-resistant HBV mutations only to mixtures of clones that have multi-drug resistant mutations and clones that have lamivudine-resistant HBV mutations only, and ultimately all clones having multi-drug resistant HBV mutations. In conclusion, mutations conferring resistance to multiple antiviral agents co-locate on the same viral genome, suggesting that combination therapy directed against mutants resistant to each treatment may not be adequate in suppressing multi-drug resistant HBV. De novo combination therapy may prevent the emergence of multi-drug resistant mutants.

Greater antiarrhythmic activity of acute 17beta-estradiol in female than male anaesthetized rats: correlation with Ca2+ channel blockade

BACKGROUND AND PURPOSE

Female sex hormones may protect pre-menopausal women from sudden cardiac death. We therefore investigated the effects of the main female sex hormone, 17beta-estradiol, on ischaemia-induced cardiac arrhythmias and on the L-type Ca2+ current (ICaL).

EXPERIMENTAL APPROACH

In vivo experiments were performed in pentobarbital-anaesthetized rats subjected to acute coronary artery occlusion. ICaL was measured by the whole-cell patch-clamp technique, in rat isolated ventricular myocytes.

KEY RESULTS

Acute intravenous administration of 17beta-estradiol as a bolus dose followed by a continuous infusion, commencing 10 min before coronary artery occlusion, had dose-dependent antiarrhythmic activity. In female rats 300 ng kg(-1) + 30 ng kg(-1) min(-1) 17beta-estradiol significantly reduced the number of ventricular premature beats (VPBs) and the incidence of ventricular fibrillation (VF). A ten fold higher dose of 17beta-estradiol was required to cause similar effects in male rats. In vitro 17beta-estradiol reduced peak ICaL in a concentration-dependent manner. The EC50 was ten-fold higher in male myocytes (0.66 microM) than in females (0.06 microM).

CONCLUSIONS AND IMPLICATIONS

These results indicate that 17beta-estradiol has marked dose-dependent antiarrhythmic activity that is greater in female rats than in males. A similar differential potency in blocking ICaL in myocytes from female and male rats can account for this effect. This provides an explanation for the antiarrhythmic activity of 17beta-estradiol and gender-selective protection against sudden cardiac death.

Clinical outcome of taxane-resistant (TR) hormone refractory prostate cancer (HRPC) patients (pts) treated with subsequent chemotherapy (ixabepilone (Ix) or mitoxantrone/prednisone (MP)

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Background: The clinical course of TR HRPC pts has not previously been evaluated in a large, prospective study. No standard treatment exists for this pt population, although MP is frequently used. Ix is an epothilone B analogue with activity against TR cell lines. Methods: Metastatic HRPC pts with disease progression during or within 60 days of stopping T chemotherapy were eligible. In a 2-arm, non-comparative randomized phase II study, pts were assigned to receive either: 1) M 14 mg/m2 IV q3wks and P 5 mg PO BID or 2) I × 35 mg/m2 IV q3wks. Crossover was allowed for progression or toxicity. The study’s primary endpoint was to detect a ≥ 50% PSA decline by Consensus Criteria in at least 25% of 2nd-line pts (H0 = 10%, α = 0.04, β = 0.18 for each arm). Pts were followed for survival. Results: Forty-one evaluable pts each were accrued to Ix and to MP. The median follow-up is 5.0 months (range: 0.3–19.5). The median number of cycles administered to each 2nd-line arm is 3 (range: Ix: 1–8, MP: 1–12). Median survival from protocol entry is 13.0 months with Ix and 12.5 months with MP. Confirmed 2nd-line post-therapy (rx) ≥50% PSA declines were observed in 17% of Ix pts (95% CI = 7–32) and 20% of MP pts (95% CI = 9–35). Of pts with measurable disease, partial responses were observed in 1/18 pts on 2nd-line Ix (6%; 95% CI = 0.1–27.3) and in 1/15 pts on 2nd-line MP (7%; 95% CI = 0.2–31.9). Median duration on 2nd-line Ix and MP was 2.2 months and 2.3 months, respectively. Crossover to 3rd-line rx occurred in 39% of Ix pts and 68% of MP pts. Confirmed 3rd-line post-rx ≥50% PSA declines were observed in 3/24 Ix pts and in 4/13 MP pts. The most common grade 3/4 toxicity associated with 2nd-line rx was neutropenia as previously reported (41% of Ix pts, 54% of MP pts). Conclusions: This prospective trial has characterized TR HRPC pts as having an observed median survival of approximately 1 year. This may be a useful reference for the screening of effective agents in the 2nd-line setting for TR HRPC. Both Ix and MP appear to have only modest activity as 2nd- and 3rd-line rx in this highly selected TR HRPC population. This study was supported by Bristol-Myers Squibb and the Prostate Cancer Foundation.

No significant financial relationships to disclose.

Absolute PSA value after androgen deprivation (AD) is a strong independent predictor of survival in new metastatic (D2) prostate cancer (PCa): Data from Southwest Oncology Group Trial 9346 (INT-0162)

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Background: PSA is a biomarker for monitoring disease activity in PCa. It is not well established if absolute PSA values achieved after AD is prognostic in patients (pts) with new D2 PCa. Methods: Hormone naive D2 pts with baseline PSA ≥ 5ng/mL are treated with 7 months (ms) AD induction. Pts achieving PSA-n (PSA ≤ 4.0 ng/ml that is stable or declining on ms 6 and 7) are randomized to continuous vs. intermittent AD on month 8. To be eligible for this analysis (approved by Data Safety Monitoring Committee), pts had to have a prestudy PSA with at least 2 subsequent PSAs during induction and be registered at least 1 year prior to analysis date. Survival was defined from 8 months to death due to any cause. Associations were evaluated by proportional hazards regression models. P≤0.05 was statistically significant. Results: Of the first 1,395 registered pts, 1345 were eligible for this analysis. Median age was 70 years, median baseline PSA 76.1 ng/mL, 38% had bone pain (BP) and 47 % had Gleason sum (GS) > 7. Median number of on-study PSAs during induction was 5 (range: 2 -18). Of the 1,345 pts, 1134 achieved PSA-n with 965 maintaining PSA-n at end of induction. Of those achieving PSA-n, 604 (45% of all pts) had an undetectable PSA (PSA-u, ≤ 0.2 ng/mL) at end of induction. In multivariate analysis, 4 significant independent risk factors were associated with post-induction survival: Performance status, GS, BP, and being randomized. After adjustment for these factors, pts who had a PSA-n at the end of induction but not PSA-u had less than half the risk of death (RoD) as those who did not have PSA-n (HR: 0.41; 95% CI 0.32, 0.54, p < 0.001), and pts with PSA-u had about one-quarter the RoD as pts with no PSA-n (HR: 0.26; 95% CI 0.20, 0.35, p < 0.001). After adjustment for covariates, pts with PSA-u had significantly better survival than those with only PSA-n at end of induction (p < 0.001). The median overall survival was 13 ms for the 383 not normalized (95% CI: 11 to 16 ms), 44 ms for the 360 pts normalized but not undetectable (95% CI: 39 to 55 ms), and 75 ms for the 602 pts with PSA-u (95% CI: 62, 91 ms). Conclusion: Achieving a PSA-n or PSA-u after 7 ms of AD is a strong predictor of survival and should be used to tailor future trial design in new D2 pts.

[Table: see text]

Sensitive line probe assay that simultaneously detects mutations conveying resistance to lamivudine and adefovir

The INNO-LiPA HBV DR v2 assay is designed to detect hepatitis B virus mutations conveying resistance to lamivudine and adefovir. Our study confirms that this assay can simultaneously detect the presence of lamivudine and adefovir resistance mutations in clinical samples, has a high degree of concordance with sequencing, and can detect mutants earlier.

Mobilisation into cotton and spread of a recombinant cotton leaf curl disease satellite

Analysis of a DNA beta satellite associated with a recently identified cotton leaf curl disease (CLCuD) strain indicated it to be recombinant, with most of the molecule originating from CLCuD DNA beta but with some sequence from a satellite isolated from tomato. Analysis of both archival (pre 2001) and recent cotton samples, shows the recombinant satellite is confined to a small area but was not present in cotton prior to 2001. This indicates that the recombinant DNA beta was recently mobilized into cotton, likely from tomato, and that recombination plays a role in the evolution of these satellites.

Virologic response and resistance to adefovir in patients with chronic hepatitis B

BACKGROUND

The incidence and risk factors for adefovir-resistant HBV have not been clearly defined.

AIMS

To characterize the virologic response to adefovir, to determine the rate of adefovir resistance and to explore factors associated with initial virologic response (IVR) and adefovir resistance.

METHODS

All hepatitis B patients who received adefovir for > or =6 months at our center were prospectively monitored for virologic response and adefovir resistance.

RESULTS

Forty three patients were included; mean treatment duration was 18 months (range 6-45). Thirty four (79%) patients had prior lamivudine. IVR was observed in 44% patients and associated with higher pretreatment ALT (P = 0.05) and the absence of HBeAg (P = 0.02). Six (14%) patients were found to have adefovir-resistant mutations. The cumulative probability of genotypic resistance to adefovir at month 24 was 22%. Patients with adefovir resistance were more likely to have been switched from lamivudine to adefovir monotherapy (P = 0.01), to be older (P = 0.04), and to be infected with HBV genotype D (P = 0.02).

CONCLUSIONS

Roughly 50% of patients failed to achieve IVR on adefovir. The cumulative probability of adefovir resistance at 2 years was 22%. Our data suggest that combination of lamivudine and adefovir may prevent emergence of adefovir resistance in patients with lamivudine-resistant HBV.

Adefovir-resistant hepatitis B can be associated with viral rebound and hepatic decompensation

BACKGROUND/AIMS

The susceptibility of adefovir-resistant hepatitis B virus (HBV) mutants is only reduced by 3-10-fold in in vitro studies, suggesting that virologic breakthrough and clinical deterioration are unlikely. The aim of this study was to describe the clinical course of patients with adefovir-resistant HBV infection.

METHODS

Testing for adefovir-resistant mutations was performed on patients who had a suboptimal response or virologic breakthrough on adefovir. Adefovir-resistant mutations were detected using a line probe assay and direct sequencing of the HBV P-gene.

RESULTS

Eight male patients with pre-existing lamivudine resistance or breakthrough (mean age 47+/-13 years) were found to have adefovir-resistant mutations rtA181V/T or rtN236T. Baseline median ALT was 66 IU/L (range, 27-1161) and median HBV DNA 7.9 log10 copies/ml (range, 6-8.3). At the time of adefovir resistance (mean of 20+/-9 months), HBV DNA increased to > or = 5 log10 copies/ml in 7 patients. After detection of adefovir resistance, hepatic decompensation occurred in 2 patients, 1 of whom died. Salvage therapy with lamivudine, entecavir or tenofovir was given to 7 patients and a reduction in HBV DNA by > or = 3 log10 was seen in 3 patients.

CONCLUSIONS

In conclusion, adefovir resistance can be associated with significant viral rebound and hepatic decompensation which may be fatal.

A longitudinal household study of Streptococcus pneumoniae nasopharyngeal carriage in a UK setting

A 10-month longitudinal household study of pre-school children and their families was undertaken with monthly visits collecting epidemiological data and nasopharyngeal swabs in Hertfordshire, England from 2001 to 2002. Pneumococcal culture was with standard methods. In total, 121 families (489 individuals) took part. Mean prevalence of carriage ranged from 52% for age groups 0-2 years, 45% for 3-4 years, 21% for 5-17 years and 8% for >or=18 years. Carriage occurred more than once in 86% of children aged 0-2 years compared to 36% of those aged >or=18 years. The most prevalent serotypes in the 0-2 years age group were 6B followed by 19F, 23F, 6A and 14. Young children were responsible for the majority of introductions of new serotypes into a household. Erythromycin resistance (alone or in combination) occurred in 10% of samples and penicillin non-susceptibility in 3.7%. Overall the recently licensed 7-valent conjugate vaccine (PCV) would protect against 64% of serotypes with no intra-serogroup cross protection and 82% with such protection. Nasopharyngeal carriage of S. pneumoniae is common in a UK setting in the pre-conjugate vaccine era. PCV would protect against a large proportion of carriage isolates. However, the impact of vaccination on non-vaccine serotypes will need to be monitored.