Clinical Significance of Circulating Serum Levels of sCD95 and TNF-α in Cytoprotection of Cervical Cancer

Background:This study correlates the serum levels of sCD95 & TNF-α with a simple cell-based assay to evaluate the capacity of the serum sample to induce apoptosis in Jurkat cells. Interlinking of these parameters can be explored to design a minimum invasive diagnostic strategy for cervical cancer (CC).Methods:Sera samples were assessed to induce apoptosis in Jurkat cells through FACS. Serum levels of sCD95 and TNF-α were measured by ELISA. JNK phosphorylation was evaluated in sera incubated Jurkat cells. Data was scrutinized through statistical analysis.Results:Significantly higher serum levels of sCD95 and lower TNF-α levels were observed in CC patients; their sera samples inhibited induction of apoptosis in Jurkat cells through reduced JNK phosphorylation. Statistical analysis linked these three parameters for the early screening of CC.Conclusion:Distinct sera levels of sCD95 & TNF-α in CC patients showed an anti-apoptotic effect, which can be considered for early detection of CC.Key Words: Apoptosis, sCD95, Jurkat Cells, Tumor Necrosis Factor-alpha, Uterine Cervical Neoplasms     

Combined millimeter wave and cyclophosphamide therapy of an experimental murine melanoma

The objective of the present studies was to investigate whether millimeter wave (MMW) therapy can increase the efficacy of cyclophosphamide (CPA), a commonly used anti-cancer drug. The effect of combined MMW-CPA treatment on melanoma growth was compared to CPA treatment alone in a murine model. MMWs were produced with a Russian made YAV-1 generator. The device produced 42.2 +/- 0.2 GHz modulated wave radiation through a 10 x 20 mm rectangular output horn. The animals, SKH-1 hairless female mice, were irradiated on the nasal area. Peak SAR and incident power density were measured as 730 +/- 100 W/kg and 36.5 +/- 5 mW/cm2, respectively. The maximum skin surface temperature elevation measured at the end of 30 min irradiation was 1.5 degrees C. B16F10 melanoma cells (0.2 x 10(6)) were implanted subcutaneously into the left flank of mice on day 1 of the experiment. On days 4-8, CPA was administered intraperitoneally (30 mg/kg/day). MMW irradiation was applied concurrently with, prior to or following CPA administration. A significant reduction (P < .05) in tumor growth was observed with CPA treatment, but MMW irradiation did not provide additional therapeutic benefit as compared to CPA alone. Similar results were obtained when MMW irradiation was applied both prior to and following CPA treatment.     

Effect of thymosin alpha 1 on the antitumor activity of tumor-associated macrophage-derived dendritic cells

We have previously suggested that thymosin ₁ (thy1), an immunomodulating thymic hormone, can activate tumor-associated macrophages to a tumoricidal state in a murine model bearing a transplantable T-cell lymphoma of spontaneous origin designated as Dalton's lymphoma (DL). Since tumor-infiltrating dendritic cells (DC) also play an important role in the host's antitumor response and are as such in an immunocompromised state in a tumor-bearing host, in the present investigation we studied if thy1 is able to influence the differentiation of tumor-associated macrophages (TAM) into DC with granulocyte macrophage colony stimulating factor (GM-CSF), interleukin (IL)-4 and tumor necrosis factor (TNF) and whether these TAM-derived DC show enhanced antitumor activity. It was observed that DC generated from thy1-administered tumor-bearing mice showed augmented antitumor activity in vitro. Adoptive immunotherapy using TAM-derived DC showed a significant delay in the tumor growth and a prolongation of the survival time in tumor-bearing mice. DC obtained from TAM of thy1-administered mice also produced an enhanced amount of cytokines like IL-1 and TNF-. This is the first study of its kind regarding the effect of thy1 on the differentiation of DC from TAM and the role of TAM-derived DC in tumor progression.     

Interaction of monodisperse anionic amphiphiles with the i-face of secreted phospholipase A2

Pancreatic IB phospholipase A(2) (PLA2) forms aggregates of defined size with monodisperse alkyl sulfates in the premicellar concentration range. As an extension of the interfacial kinetic paradigm, results are interpreted in terms of a model in which several amphiphile molecules bind along their polar headgroup to the interface binding region (i-face) of PLA2. The resulting complex, E(#), has a half-micellar structure, and it acts as an "amphiphile" in the aqueous phase. E(#) not only self-aggregates but also binds hydrophobic probes and interacts with hydrophobic surfaces. As expected, resonance energy transfer from the tryptophan donor in PLA2 to an acceptor probe partitioned in E(#) shows a biphasic dependence as the probe coexisting with PLA2 is diluted at higher alkyl sulfate concentrations. The gel-permeation behavior of PLA2 at premicellar alkyl sulfate concentrations is also biphasic. For example, above 1.2 mM decyl sulfate (CMC = 3.5 mM) PLA2 elutes as a single sharp peak, presumably the self-aggregate of E(#) with apparent molecular mass of 120-150 kDa. At 0.4-1 mM decyl sulfate the retention volume is even larger than that for the 14 kDa PLA2. This anomalous retention is attributed to the interaction of the hydrophobic region of E(#) with the hydrophobic patches on the gel-permeation matrix. Elution behavior of the self-aggregated E(#) form of site-directed mutants in dodecyl sulfate suggests that certain substitutions in the conserved hydrogen-bonding network have a significant effect on the aggregate size. These results suggest a role for the network in the amphiphile binding along the i-face of PLA2, presumably through a change in the anion coordination ligands.     

Disruption of neurogenesis by amyloid beta-peptide,and perturbed neural progenitor cell homeostasis,in models of Alzheimer's disease

Neurogenesis occurs in the adult mammalian brain and may play roles in learning and memory processes and recovery from injury, suggesting that abnormalities in neural progenitor cells (NPC) might contribute to the pathogenesis of disorders of learning and memory in humans. The objectives of this study were to determine whether NPC proliferation, survival and neuronal differentiation are impaired in a transgenic mouse model of Alzheimer's disease (AD), and to determine the effects of the pathogenic form of amyloid beta-peptide (Abeta) on the survival and neuronal differentiation of cultured NPC. The proliferation and survival of NPC in the dentate gyrus of the hippocampus was reduced in mice transgenic for a mutated form of amyloid precursor protein that causes early onset familial AD. Abeta impaired the proliferation and neuronal differentiation of cultured human and rodent NPC, and promoted apoptosis of neuron-restricted NPC by a mechanism involving dysregulation of cellular calcium homeostasis and the activation of calpains and caspases. Adverse effects of Abeta on NPC may contribute to the depletion of neurons and cognitive impairment in AD.     

Crystal structure of phospholipase A2 complex with the hydrolysis products of platelet activating factor: equilibrium binding of fatty acid and lysophospholipid-ether at the active site may be mutually exclusive

We have solved the 1.55 A crystal structure of the anion-assisted dimer of porcine pancreatic group IB phospholipase A2 (PLA2), complexed with the products of hydrolysis of the substrate platelet activating factor. The dimer contains five coplanar phosphate anions bound at the contact surface between the two PLA2 subunits. This structure parallels a previously reported anion-assisted dimer that mimics the tetrahedral intermediate of PLA2 bound to a substrate interface [Pan, Y. H., et al. (2001) Biochemistry 40, 609-617]. The dimer structure has a molecule of the product acetate bound in subunit A and the other product 1-octadecyl-sn-glycero-3-phosphocholine (LPC-ether) to subunit B. Therefore, this structure is of the two individual product binary complexes and not of a ternary complex with both products in one active site of PLA2. Protein crystals with bound products were only obtained by cocrystallization starting from the initial substrate. In contrast, an alternate crystal form was obtained when PLA2 was cocrystallized with LPC-ether and succinate, and this crystal form did not contain bound products. The product bound structure has acetate positioned in the catalytic site of subunit A such that one of its oxygen atoms is located 3.5 A from the catalytic calcium. Likewise, a longer than typical Ca-to-Gly(32) carbonyl distance of 3.4 A results in a final Ca coordination that is four-coordinate and has distorted geometry. The other oxygen of acetate makes hydrogen bonds with N(delta)(1)-His(48), O(delta)(1)-Asp(49), and the catalytic assisting water (w7). In contrast, the glycerophosphocholine headgroup of LPC-ether in subunit B makes no contacts with calcium or with the catalytic residues His(48) or Asp(49). The tail of the LPC-ether is located near the active site pocket with the last nine carbons of the sn-1- acyl chain refined in two alternate conformations. The remaining atoms of the LPC-ether product have been modeled into the solvent channel but have their occupancies set to zero in the refined model due to disorder. Together, the crystallographic and equilibrium binding results with the two products show that the simultaneous binding of both the products in a single active site is not favored.     

Two acyl sucroses from Petunia nyctaginiflora

Two new acyl sucroses were isolated from the epigeal parts of Petunia nyctaginiflora Juss. (Solanaceae). Their structures were determined to be 2, 3, 4-tri (5-methylhexanoyl)-alpha-D-glucopyranosyl-beta-D-fructofuranoside (2) and 2, 3, 4-tri (6-methylheptanoyl)-alpha-D-glucopyranosyl-beta-D-fructofuranoside (4) on the basis of chemical and spectroscopic evidence.     

Local repeat sequence organization of an intergenic spacer in the chloroplast genome ofChlamydomonas reinhardtii leads to DNA expansion and sequence scrambling: A complex mode of “copychoice replication”?

Parent-specific, randomly amplified polymorphic DNA (RAPD) markers were obtained from total genomic DNA ofChlamydomonas reinhardtii. Such parent-specific RAPD bands (genomic fingerprints) segregated uniparentally (through mt⁺) in a cross between a pair of polymorphic interfertile strains ofChlamydomonas (C. reinhardtii andC. minnesotti), suggesting that they originated from the chloroplast genome. Southern analysis mapped the RAPD-markers to the chloroplast genome. One of the RAPD-markers, “P2” (1.6 kb) was cloned, sequenced and was fine mapped to the 3 kb region encompassing 3′ end of 23S, full 5S and intergenic region between 5S and psbA. This region seems divergent enough between the two parents, such that a specific PCR designed for a parental specific chloroplast sequence within this region, amplified a marker in that parent only and not in the other, indicating the utility of RAPD-scan for locating the genomic regions of sequence divergence. Remarkably, the RAPD-product, “P2” seems to have originated from a PCR-amplification of a much smaller (about 600 bp), but highly repeat-rich (direct and inverted) domain of the 3 kb region in a manner that yielded no linear sequence alignment with its own template sequence. The amplification yielded the same uniquely “sequence-scrambled” product, whether the template used for PCR was total cellular DNA, chloroplast DNA or a plasmid clone DNA corresponding to that region. The PCR product, a "unique" new sequence, had lost the repetitive organization of the template genome where it had originated from and perhaps represented a “complex path” of copy-choice replication.     

The explosive human immunodeficiency virus type 1 epidemic among injecting drug users of Kathmandu, Nepal, is caused by a subtype C virus of restricted genetic diversity

An explosive epidemic of human immunodeficiency virus type 1 (HIV-1) has been documented among the injecting drug user population of Kathmandu, Nepal, whose seropositivity rate has risen from 0 to 40% between 1995 and 1997. By using Catrimox to preserve whole-blood RNA at ambient temperature for transportation, HIV-1 envelope V3-V4 sequences were obtained from 36 patients in this group. Analysis of the sequences indicated a homogenous epidemic of subtype C virus, with at least two independent introductions of the virus into the population. Viral diversity was restricted within two transmission subclusters, with the majority of variation occurring in V4. Calculation of the synonymous-to-nonsynonymous mutation ratio (Ks:Ka) across this region showed that significant evolutionary pressure had been experienced during the rapid horizontal spread of the virus in this population, most strongly directed to the region between V3 and V4.