Subgenotypes of hepatitis B virus genotype D (D1, D2, D3 and D5) in India: differential pattern of mutations, liver injury and occult HBV infection

Hepatitis B genotype D (HBV/D) is the most widespread genotype and exists as at least five subgenotypes (HBV/D1-D5). However, little is known about the association of virological characteristics with clinical differences among HBV/D subgenotypes. To investigate the virological characteristics of these subgenotypes and their clinical implications, we selected a cohort of 109 genotype D infected individuals from the state of West Bengal, India, including 68 HBsAg positive patients and 41 with occult HBV infection. Among the HBsAg positive subjects 28 had chronic hepatitis B virus infection, 40 were asymptomatic carriers based on clinical examination, liver function test and ultrasonograph results. Overall, HBV/D1 was found in 17%, HBV/D2 in 29%, HBV/D3 in 34% and HBV/D5 in 20% of the cases. HBV/D1 was significantly associated with chronic liver disease (P = 0.01), and in this subgenotype A1896 (PreC mutations) were most common. Although BCP mutations (A/C1753 and T1762/A1764) were found to be frequently associated with HBV/D2 (33% and 33%) and D5 (47% and 59%), no apparent clinical correlation was observed. On the other hand, occult HBV infection was significantly associated with HBV/D3 infection, along with low level of BCP and PreC mutations and several non-synonymous substitutions in the catalytic reverse transcriptase (RT) domain of polymerase gene. Similar nucleotide substitutions in the surface (S) gene region were observed from both northern and eastern Indian HBV/D3 isolates. In conclusion, HBV/D subgenotypes differ in their mutational patterns in the S, polymerase and the BCP/PreC regions that may influence their clinical outcomes.

Impact of combined exposure of chemical, fertilizer, bio-fertilizer and compost on growth, physiology and productivity of Brassica campestries in old alluvial soil

Field experiment was carried out during November 2006 to February 2007 under old alluvial soil to evaluate the impact of combined dose of chemical fertilizer, biofertilizer in combination with compost for the yellow sarson (Brassica campestries cv. B9) in a randomized block design replicated thrice. Various morpho-physiological parameters viz., plant population, length of shoot and root, leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), yield attributes viz., number of siliquae per plant, number of seeds/siliquae, 1000 seed weight (test weight), seed yield, stover yield and physiological and biochemical parameters viz., pigment content, sugar, amino acid, protein, ascorbic acid content in physiologically active leaf were performed. The treatment T1 i.e., 40% less N fertilizer 25% less P fertilizer K fertilizer constant + 12 kg ha(-1) biofertilizer (Azophos) and organic manure (compost) @ 5Mt ha(-1), showed the maximum chlorophyll accumulation (10. 231 mg g(-1) freshweight), highest seed/siliquae (25.143), test weight of seeds (4. 861g) and highest seed yield (10.661 tha(-1)). A comparison between all the morphological, anatomical, physiological and biochemical parameters due to application of chemical fertilizer; bio-fertilizer and compost alone and in combination and their impact on soil microorganism, flora and fauna will throw a sound environmental information.

Synthesis and characterization of ferromagnetic cobalt nanospheres, nanodiscs and nanocubes

We report the synthesis of cobalt nanoparticles with different shapes and sizes by rapid pyrolysis of cobalt carbonyl in the presence of various surfactants. The size and shape of the nanoparticles were influenced by reaction conditions, such as type of the surfactant, molar ratio of surfactant to precursor, reflux temperature and reaction time. The shapes that we have achieved include spherical, nearly spherical, disc and cube. The presence of linear amine yielded nanodiscs and they spontaneously self-assembled into long ribbons. The effect of shape anisotropy on magnetic nanoparticles has been investigated. Spherical nanoparticles of diameter 14.5 nm show strong ferromagnetic behavior at low temperature and superparamagnetism at room temperature. On the other hand the cubic nanoparticles of 45 nm sides showed negligible coercive field at T=10 K and ferromagnetism that persisted above T=300 K. The cobalt nanospheres were oxidized to grow cobalt oxide shell of varying thickness to study exchange bias effect. A pronounced exchange bias and a strong temperature dependant magnetization were observed in oxidized cobalt nanospheres.

Evaluation of p53 and BCL2 expression, mutation, and aneuploidy status on treatment response in an Indian cohort of primary Ca larynx

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Background: Organ-sparing therapy consisting of cisplatin and 5-fluorouracil, combined with radiation for advanced head and neck squamous cell carcinoma (HNSCC) have been advocated in Ca larynx patients. However, failure of some tumors to respond to treatment or tumor recurrence limits the overall success of these therapies. P53 mutations have been linked to cisplatin resistance in other solid tumors. In this study we evaluate the relationships between P53 overexpression/mutations, BCL2 expression and ploidy status on treatment response in retrospective cohort of Ca Larynx patients. Methods: Samples from 18 patients with histopathologically confirmed Ca Larynx were analysed from our biorepository after consent. Clinical, sociodemographic information and response to treatment were abstracted from case records. P53 and BCL2 over expression were checked by IHC and p53 mutation by PCR and direct sequencing. DNA ploidy and S-phase fractions were also analysed. Bivariate relationships were determined between these variables using Spearmans rank correlation. Independent samples t tests were used to determine changes in P53 over expression, BCL2 expression Ploidy status and S phase fractions in both responders and non responders. Results: There was a trend for increase in P53 over expression and BCL2 expression and decrease in S phase fractions in responders vs non responders. Neither p53 over expression (75% of cases) and BCL2 over expression (17% of cases) correlated significantly with treatment response. However, BCL2 expression correlated negatively with disease stage (r = - 0.57, p = 0.02). Aneuploidy was observed in node positive tumors (p = 0.04). Conclusions: The results suggest poor association of molecular markers with treatment response and should not be relied as a marker for treatment response. Though there is a trend for association a larger sample size is required to demonstrate the findings.

No significant financial relationships to disclose.

Sex-Specific Familial Clustering of Myocardial Infarction in Patients With Acute Coronary Syndromes

Background— Family history of premature myocardial infarction (MI) in first-degree relatives is a risk factor for MI and an indication for primary prevention. Although excess mother-to-daughter “transmission” occurs in ischemic stroke, no published studies have considered sex-of-parent/sex-of-proband interactions in the heritability of MI.

Methods and Results— In a population-based study (Oxford Vascular Study) of all patients with acute coronary syndromes (ACS), irrespective of age, family history of all acute vascular events and related risk factors were analyzed by sex and age of both probands and first-degree relatives. Premature events were categorized as occurring at age <65 years. Of 835 probands with 1 or more ACS, 623 (420 men) had incident events and complete family history data. In probands with premature ACS, maternal history of both MI and of all vascular events were more common in female than male probands (odds ratio [OR], 2.25; 95% CI, 1.02 to 4.94; P =0.04 and OR, 3.03; 95% CI, 1.47 to 6.26; P =0.002, respectively). No such effect existed for paternal history (OR, 1.00; 95% CI, 0.46 to 2.10; P =0.99 and OR, 1.19; 95% CI, 0.58 to 2.43; P =0.63, respectively). Age at ACS in probands was highly correlated with age at MI in mothers ( r =0.46, P <0.001), regardless of the proband’s sex. Consequently, history of premature maternal MI was strongly associated with premature ACS and premature MI in female (OR, 10.52; 95% CI, 2.17 to 56.6; P =0.001 and OR, 7.31; 95% CI, 1.55 to 34.6; P =0.004, respectively) and male probands (OR, 3.88; 95% CI, 1.20 to 12.6; P =0.01 and OR, 3.63; 95% CI, 1.13 to 11.60; P =0.02, respectively).

Conclusions— Important sex-of-parent/sex-of-proband interactions exist in the family history of MI in patients with ACS. Greater emphasis should be placed on maternal than paternal history of MI, particularly in women aged <65 years.

Selective substitution in orbital domains of a low doped manganite: an investigation from Griffiths phenomenon and modification of glassy features

An effort is made to study the contrast in magnetic behavior resulting from minimal disorder introduced by substitution of 2.5% Ga or Al in Mn site of La(0.9)Sr(0.1)MnO(3). It is considered that Ga or Al selectively create disorder within the orbital domains or on its walls, causing enhancement of Griffiths phase (GP) singularity for the former and disappearance of it in the latter case. It is shown that Ga replaces Mn(3+), which is considered to be concentrated within the domains, whereas Al replaces Mn(4+), which is segregated on the hole-rich walls, without causing any significant effect on structure or ferromagnetic transition temperatures. Thus, it is presumed that the effect of disorder created by Ga extends across the bulk of the domain having correlation over a similar length scale, resulting in enhancement of the GP phenomenon. In contrast, the effect of disorder created by Al remains restricted to the walls, resulting in the modification of the dynamics arising from the domain walls and suppresses the GP. Moreover, contrasting features are observed in the low temperature region of the compounds; a re-entrant spin-glass-like behavior is observed in the Ga-doped sample, while the observed characteristics for the Al-doped sample are ascribed only to modified domain wall dynamics with the absence of any glassy phase. Distinctive features in third-order susceptibility measurements reveal that the magnetic ground state of the entire series comprises of orbital domain states. These observations bring out the role of the nature of disorder on the GP phenomenon and also reconfirms the character of self-organization in low doped manganites.

Anomalous x-ray diffraction peak broadening and lattice strains in Zn(1-x)Co(x)O dilute magnetic semiconductors

Nanocrystalline powders of Zn(1-x)Co(x)O synthesized by the coprecipitation technique show anomalous anisotropic broadening for x>0.05. This peak broadening is shown to be not only due to a reduction in the particle size but also due to a significant strain contribution, as confirmed by Williamson-Hall analysis. The presence of grouped Co(2+) ions, revealing the presence of clusters of high spin Co(2+) with antiferromagnetically coupled spins, as indicated by magnetization studies, seems to be responsible for the strain.

The possibility for surface plasmons lasers

We have demonstrated for the first time, attributes of a surface plasmons' laser: threshold, gain, spectral line narrowing and feedback in the visible range. The surface metallic waveguides were consisted of a nano-scale hole-array in a 50 nm thick layer of aluminum oxide on top of aluminum substrate (anodized aluminum oxide or, AAO). In some cases, two-layer graphene was added on top of the perforated oxide layer, as well. The sub-wavelength array of holes enabled coupling to and from the waveguides as well as, providing feedback to the surface modes. The gain media molecules (fluorescein) were imbedded in the structure's pores. Threshold and spectral line narrowing of 30% were clearly demonstrated when pumped with a pulsed laser.

Conversion of a glassy antiferromagnetic-insulating phase to an equilibrium ferromagnetic-metallic phase by devitrification and recrystallization in Al substituted Pr(0.5)Ca(0.5)MnO(3)

We show that Pr(0.5)Ca(0.5)MnO(3) with 2.5% Al substitution and La(0.5)Ca(0.5)MnO(3) (LCMO) exhibit qualitatively similar and visibly anomalous M-H curves at low temperature. Magnetic field causes a broad first order but irreversible antiferromagnetic (AF)-insulating (I) to ferromagnetic (FM)-metallic (M) transition in both and gives rise to a soft FM state. However, the low temperature equilibrium state of Pr(0.5)Ca(0.5)Mn(0.975)Al(0.025)O(3) (PCMAO) is FM-M whereas that of LCMO is AF-I. In both systems the respective equilibrium phase coexists with the other phase with contrasting order, which is not in equilibrium, and the cooling field can tune the fractions of the coexisting phases. It is shown earlier that the coexisting FM-M phase behaves like 'magnetic glass' in LCMO. Here we show from specially designed measurement protocols that the AF-I phase of PCMAO has all the characteristics of magnetic glassy states. It devitrifies on heating and also recrystallizes to an equilibrium FM-M phase after annealing. This glass-like AF-I phase also shows a similar intriguing feature observed in FM-M magnetic glassy state of LCMO, that when the starting coexisting fraction of glass is larger, successive annealing results in a larger fraction of the equilibrium phase. This similarity between two manganite systems with contrasting magnetic orders of respective glassy and equilibrium phases points to a possible universality.

Probability, clinical decision making and hypothesis testing

Few clinicians grasp the true concept of probability expressed in the 'P value.' For most, a statistically significant P value is the end of the search for truth. In fact, the opposite is the case. The present paper attempts to put the P value in proper perspective by explaining different types of probabilities, their role in clinical decision making, medical research and hypothesis testing.