Immunological and molecular epidemiological characteristics of acute and fulminant viral hepatitis A

<p>Abstract</p> <p>Background</p> <p>Hepatitis A virus is an infection of liver; it is hyperendemic in vast areas of the world including India. In most cases it causes an acute self limited illness but rarely fulminant. There is growing concern about change in pattern from asymptomatic childhood infection to an increased incidence of symptomatic disease in the adult population.</p> <p>Objective</p> <p>In-depth analysis of immunological, viral quantification and genotype of acute and fulminant hepatitis A virus.</p> <p>Methods</p> <p>Serum samples obtained from 1009 cases of suspected acute viral hepatitis was employed for different biochemical and serological examination. RNA was extracted from blood serum, reverse transcribed into cDNA and amplified using nested PCR for viral quantification, sequencing and genotyping. Immunological cell count from freshly collected whole blood was carried out by fluorescence activated cell sorter.</p> <p>Results</p> <p>Fulminant hepatitis A was mostly detected with other hepatic viruses. CD8⁺T cells count increases in fulminant hepatitis to a significantly high level (P = 0.005) compared to normal healthy control. The immunological helper/suppressor (CD4⁺/CD8⁺) ratio of fulminant hepatitis was significantly lower compared to acute cases. The serologically positive patients were confirmed by RT-PCR and total of 72 (69.2%) were quantified and sequenced. The average quantitative viral load of fulminant cases was significantly higher (<it>P </it>< 0.05). There was similar genotypic distribution in both acute and fulminant category, with predominance of genotype IIIA (70%) compared to IA (30%).</p> <p>Conclusions</p> <p>Immunological factors in combination with viral load defines the severity of the fulminant hepatitis A. Phylogenetic analysis of acute and fulminant hepatitis A confirmed genotypes IIIA as predominant against IA with no preference of disease severity.</p

Isospin and spin-isospin modes in charge-exchange reactions

The microscopic structure of the Gamow-Teller resonance (GTR) and spin-dipole resonance (SDR) in 208Bi has been investigated in the 208Pb(3He,tp)207Pb reaction at E(3He)=450 MeV and very forward scattering angles. The partial and total branching ratios and the escape widths for GTR and SDR decay to the residual neutron-hole states in 207Pb were deduced. These are found to be in good agreement with recent theoretical estimates. The (3He,tp) reaction on Pb at E(3He)=177 MeV was also studied in order to locate isovector monopole strength corresponding to 2ℏω transitions. Monopole strength at excitation energies above 25 MeV was discovered and compared to calculated strength due to the isovector giant monopole resonance and the spin-flip isovector monopole resonance. Calculations in a normal-mode framework show that all isovector monopole strength can be accounted for if the branching ratio for decay by proton emission is 20%

Three fragment sequential decay of heavy nuclei around 3 MeV/u excitation energy

A new method is proposed to identify the sequential decay of hot nuclei into large fragments. This method is based on a minimization procedure. It is illustrated for the Ar+Au reaction at 30 MeV/u. In this case, corresponding to about 3 MeV/u excitation energy, it is shown that the three fragment production can be explained by sequential binary splittings.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Rapid decrease of fragment emission time in the range of 3-5 MeV/u excitation energy

Multifragment emission processes from highly excited nuclei produced in 40Ar+197Au reactions at incident energies of 30 and 60 McV/u are compared. At the lowest bombarding energy and 3.3 MeV/u excitation energy, the composite system decay process supports the hypothesis of long-lived equilibrated nuclei decaying by successive binary splittings. For excited nuclei around 5 MeV/u, the depletion observed at small relative angles in the correlation functions is interpreted as the result of a strong reduction in the fragment emission time scale.SCOPUS: ar.jinfo:eu-repo/semantics/publishe