Inhibition of hepatitis B virus DNA replicative intermediate forms by recombinant interferon-γ

AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine.METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization.RESULTS: IFN-γ at 0.1 to 5 μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells.At 5 μg/L, IFN-γ also suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γ showed no additive effect,sequential treatment first with lamivudine and then IFN-γ was found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2 μmol/L lamivudine for two days, followed by 1 μg/L IFN-γ for another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2 μmol/L lamivudine for two days, followed by 5 μg/L IFN-γ for six days showed a 72% reduction in HBV cccDNA pool.CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γ and lamivudine,especially in IFN-α non-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants.     

Abdominal Dermis-Fat Graft Versus Conventional Temporalis Myofascial Flap Interposition in Temporomandibular Joint Ankylosis: A Prospective Clinical Comparative Study

IntroductionTemporomandibular joint (TMJ) ankylosis is an extremely disabling condition with almost complete inability to open the jaws causing difficulty in chewing, speech, poor oral hygiene and cosmetic disfigurement. Temporalis myofascial flap still remains the most common interpositional material used; however, patients usually complain of pain during movement, unesthetic bulging in the temporal region and trismus due to scar contracture. The main aim of the study was to evaluate the efficacy of abdominal dermis-fat graft and compare it with temporalis myofascial flap as to see which of the two grafts offers more advantages and provides better postoperative results following TMJ ankylosis surgery. Materials and MethodsA total of 30 diagnosed cases of TMJ ankylosis were randomly divided into two groups of 15 patients each. All the patients underwent TMJ ankylosis release under general anesthesia followed by abdominal dermis-fat interposition in Group A and temporalis muscle in Group B. The patients were assessed for pre-operative and postoperative mouth opening (immediate and 6 month postoperative), pain during physiotherapy, donor and surgical site complications and recurrence of ankylosis.ResultsThe mean maximum inter-incisal opening in dermis-fat group was significantly higher than temporalis group both at immediate and 6 month postoperative periods (p = 0.041, 0.001). Physiotherapy was less painful in dermis-fat group than in temporalis group, and the differences in VAS scores among the 2 groups showed high statistical significance (p < 0.001). Hypertrophic scar developed at the donor site in 2 patients in dermis-fat group; however, it was located below the beltline and hardly noticeable. A total of 9 patients (4 in Group A and 5 in Group B) developed temporary facial nerve weakness, and no case of re-ankylosis was noted in either group.ConclusionDermis-fat graft in temporomandibular joint ankylosis showed better results than conventional temporalis myofascial flap in terms of postoperative mouth opening, physiotherapy and jaw function with esthetically acceptable results.     

Conformational dynamics of superoxide dismutase (SOD1) in osmolytes: a molecular dynamics simulation study

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease caused by the misfolding of Cu, Zn superoxide dismutase (SOD1). Several earlier studies have shown that monomeric apo SOD1 undergoes significant local unfolding dynamics and is the predecessor for aggregation. Here, we have employed atomistic molecular dynamics (MD) simulations to study the structure and dynamics of monomeric apo and holo SOD1 in water, aqueous urea and aqueous urea–TMAO (trimethylamine oxide) solutions. Loop IV (zinc-binding loop) and loop VII (electrostatic loop) of holo SOD1 are considered as functionally important loops as they are responsible for the structural stability of holo SOD1. We found larger local unfolding of loop IV and VII of apo SOD1 as compared to holo SOD1 in water. Urea induced more unfolding in holo SOD1 than apo SOD1, whereas the stabilization of both the form of SOD1 was observed in ternary solution (i.e. water/urea/TMAO solution) but the extent of stabilization was higher in holo SOD1 than apo SOD1. The partially unfolded structures of apo SOD1 in water, urea and holo SOD1 in urea were identified by the exposure of the hydrophobic cores, which are highly dynamic and these may be the initial events of aggregation in SOD1. Our simulation studies support the formation of aggregates by means of the local unfolding of monomeric apo SOD1 as compared to holo SOD1 in water.

Change in conformations of apo and holo SOD1 in water and in osmolytes in terms of configurational entropy (S).     

Palladium nanoparticles as efficient catalyst for C–S bond formation reactions

The development of green, economical and sustainable chemical processes is one of the primary challenges in organic synthesis. Herein, we report an efficient and heterogeneous palladium-catalyzed sulfonylation of vinyl cyclic carbonates with sodium sulfinates via decarboxylative cross-coupling. Both aliphatic and aromatic sulfinate salts react with various vinyl cyclic carbonates to deliver the desired allylic sulfones featuring tri- and even tetrasubstituted olefin scaffolds in high yields with excellent selectivity. The process needs only 2 mol% of Pd₂(dba)₃ and the in situ formed palladium nano-particles are found to be the active catalyst.

Heterogenous catalysis: economical and sustainable synthesis of allylic sulfone featuring tri- and even tetrasubstituted olefin scaffold via decarboxylative cross-coupling from vinyl cyclic carbonates with sodium sulfinates using PdNPs as a catalyst.     

Study of Surgical Emergencies of Tubercular Abdomen in Developing Countries

To study the various modes of presentation, diagnosis, and management of surgical emergencies of tubercular abdomen. This prospective study of surgical emergencies of tubercular abdomen was conducted in 50 patients who attended our surgical emergency from 2006 to 2008. Patients were evaluated thoroughly with history, physical examination, routine investigations, and special investigations such as ELISA, PCR, barium studies of gastrointestinal tract, and diagnostic laparoscopy as required and managed with medical and surgical treatment as necessary. The most of patients were from rural areas, in the third to sixth decades with slight male preponderance. Abdominal pain, vomiting, and constipation were commonest presenting symptoms. About 20 % patients had history of pulmonary tuberculosis and 16 % patients presented with ascites. PCR for blood and ascitic fluid was positive in 72 and 87.5 % patients, respectively. About 24 % patients were managed nonoperatively and responded to ATT. About 76 % patients needed surgery among which one-fifth of patients were operated in emergency. Procedures like adhesiolysis of gut (47.3 %), strictureplasty (10.5 %), resection anastomosis (5.2 %), right hemicolectomy (5.2 %), and ileotransverse anastomosis (7.8 %) were performed in 30 patients and peritoneal biopsy and lymph node biopsy in the remaining 8 patients. Both medically and surgically managed patients were put on antitubercular therapy. Abdominal tuberculosis is a disease of middle-aged rural people, presenting commonly with abdominal pain and vomiting with right lower abdominal tenderness. PCR (blood and ascites) for tuberculosis is much more sensitive than IgM ELISA (blood and ascites). The most of patients required surgical procedures and all patients responded dramatically to antitubercular therapy symptomatically with increase in the hemoglobin level and decrease in ESR.     

Gene transfer to primary normal and malignant human hemopoietic progenitors using recombinant retroviruses

To study the feasibility of using retroviruses for gene transfer into human hemopoietic cells, various cell types were exposed to virus carrying the gene for neomycin resistance (neor). In preliminary studies using K562 cells as targets, we found that high viral titer and co-cultivation with viral producer cells rather than incubation in medium exposed to viral producer cells were important variables for achieving high frequencies of G418 resistant (G418r) colonies. The maximum frequency of G418r K562 colonies after co-cultivation with cells producing a neor virus titer of 4 X 10(6) cfu/mL was 60%. When primary human progenitors from normal marrow, fetal liver, or chronic myelogenous leukemia blood were exposed to high titer viral stocks, both with and without helper virus, under conditions optimized for K562 cells, maximum frequencies of G418r colonies were 3% to 16% for granulocyte macrophage progenitors and 2% to 6% for primitive erythroid progenitors. The presence of the neor gene in both G418r K562 and primary hemopoietic colonies was verified by Southern blot. Expression of the neor gene was shown by RNA spot blot. These data demonstrate efficient transfer and expression of the neor gene in both K562 cells and primary human hemopoietic cells from normal and leukemic individuals.     

Molecular Evidence of Helicobacter Pylori Infection in Prostate Tumors

Objectives

To determine whether Helicobacter pylori (H. pylori) is detectable in both benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Epidemiological studies have shown significant associations between infective chronic prostatitis and prostatic carcinoma. Many bacteria have been found in the prostate of patients with chronic prostatitis, BPH, and PCa.

Methods

One hundred consecutive patients with prostate diseases were enrolled in the study. Detection of H. pylori DNA in prostate tissue from patients with BPH and PCa was performed using both immunohistochemistry and PCR, and the results were confirmed by DNA sequencing. Odds ratios and the Fisher Exact test were used for the analysis of the associations between the variables.

Results

Among the patients, 78% had BPH and 19% had PCa. While immunohistochemistry showed no positive sample for H. pylori, PCR combined with sequencing detected H. pylori DNA in prostate tissue samples from 5 patients. However, statistical analysis of the data showed that BPH and PCa are not significantly associated with the presence of H. pylori DNA in prostate tissue (odds ratio = 0.94, 95% confidence interval = 0.09–23.34, one-tailed Chi-square value = 0.660, p > 0.05). The limitation of this study was the small number of PCa patients.

Conclusions

This study provides, for the first time, molecular evidence of the presence of H. pylori DNA in prostatic tissue of patients with BPH and PCa. It paves the way for further comprehensive studies to examine the association of H. pylori infection with BPH and PCa.Key Words: Helicobacter pylori infection, Prostate cancer, Benign prostate hyperplasia, PCR