Paramagnetic molecule induced strong antiferromagnetic exchange coupling on a magnetic tunnel junction based molecular spintronics device

This paper reports our Monte Carlo (MC) studies aiming to explain the experimentally observed paramagnetic molecule induced antiferromagnetic coupling between ferromagnetic (FM) electrodes. Recently developed magnetic tunnel junction based molecular spintronics devices (MTJMSDs) were prepared by chemically bonding the paramagnetic molecules between the FM electrodes along the tunnel junction's perimeter. These MTJMSDs exhibited molecule-induced strong antiferromagnetic coupling. We simulated the 3D atomic model analogous to the MTJMSD and studied the effect of molecule's magnetic couplings with the two FM electrodes. Simulations show that when a molecule established ferromagnetic coupling with one electrode and antiferromagnetic coupling with the other electrode, then theoretical results effectively explained the experimental findings. Our studies suggest that in order to align MTJMSDs' electrodes antiparallel to each other, the exchange coupling strength between a molecule and FM electrodes should be ∼50% of the interatomic exchange coupling for the FM electrodes.

Experimental model for ELF-EMF exposure: Concern for human health

Low frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society and in the last 20 years the interest about the possible effect of extremely low frequency (ELF) EMFs on human health has increased progressively. Epidemiological studies, designed to verify whether EMF exposure may be a potential risk factor for health, have led to controversial results. The possible association between EMFs and an increased incidence of childhood leukemia, brain tumors or neurodegenerative diseases was not fully elucidated. On the other hand, EMFs are widely used, in neurology, psychiatry, rheumatology, orthopedics and dermatology, both in diagnosis and in therapy. In vitro studies may help to evaluate the mechanism by which LF-EMFs affect biological systems. In vitro model of wound healing used keratinocytes (HaCaT), neuroblastoma cell line (SH-SY5Y) as a model for analysis of differentiation, metabolism and functions related to neurodegenerative processes, and monocytic cell line (THP-1) was used as a model for inflammation and cytokines production, while leukemic cell line (K562) was used as a model for hematopoietic differentiation. MCP-1, a chemokine that regulates the migration and infiltration of memory T cells, natural killer (NK), monocytes and epithelial cells, has been demonstrated to be induced and involved in various diseases. Since, varying the parameters of EMFs different effects may be observed, we have studied MCP-1 expression in HaCaT, SH-SY5Y, THP-1 and K562 exposed to a sinusoidal EMF at 50 Hz frequency with a flux density of 1 mT (rms). Our preliminary results showed that EMF-exposure differently modifies the expression of MCP-1 in different cell types. Thus, the MCP-1 expression needs to be better determined, with additional studies, with different parameters and times of exposure to ELF-EMF.

Corals from the Persian/Arabian Gulf as models for thermotolerant reef-builders: prevalence of clade C3 Symbiodinium, host fluorescence and ex situ temperature tolerance

Corals in the Arabian/Persian Gulf endure summer temperatures of up to 36°C, making them ideal subjects to study the mechanisms underlying thermal tolerance. Unexpectedly, we found the "generalist" Symbiodinium clade C3 to be the prevalent symbiont among seven coral species from Abu Dhabi (UAE) waters. Moreover, C3 represented the only dominant symbiont type in Porites spp. from this region. The "thermotolerant" symbionts D1a and C15 were not encountered, indicating that the association with these symbionts cannot be the sole reason for the heat tolerance of Gulf corals. The association of Porites lobata with specific symbiont types (C3 vs. C15) in samples from habitats with very different temperature regimes (Abu Dhabi vs. Fiji) remained unaffected by laboratory culture. During temperature stress experiments specimens from both locations strongly downregulated green fluorescent protein (GFP)-like pigments. However, the Abu Dhabi samples were less prone to bleaching and showed lower mortality.

Recombinant human parainfluenza virus type 2 with mutations in V that permit cellular interferon signaling are not attenuated in non-human primates

The HPIV2 V protein inhibits type I interferon (IFN) induction and signaling. To manipulate the V protein, whose coding sequence overlaps that of the polymerase-associated phosphoprotein (P), without altering the P protein, we generated an HPIV2 virus in which P and V are expressed from separate genes (rHPIV2-P+V). rHPIV2-P+V replicated like HPIV2-WT in vitro and in non-human primates. HPIV2-P+V was modified by introducing two separate mutations into the V protein to create rHPIV2-L101E/L102E and rHPIV2-Delta122-127. In contrast to HPIV2-WT, both mutant viruses were unable to degrade STAT2, leaving virus-infected cells susceptible to IFN. Neither mutant, nor HPIV2-WT, induced significant amounts of IFN-beta in infected cells. Surprisingly, neither rHPIV2-L101E/L102E nor rHPIV2-Delta122-127 was attenuated in two species of non-human primates. This indicates that loss of HPIV2's ability to inhibit IFN signaling is insufficient to attenuate virus replication in vivo as long as IFN induction is still inhibited.

IL-22 defines a novel immune pathway of antifungal resistance

The role of IL-17 and Th17 cells in immunity vs. pathology associated with the human commensal Candida albicans remains controversial. Both positive and negative effects on immune resistance have been attributed to IL-17/Th17 in experimental candidiasis. In this study, we provide evidence that IL-22, which is also produced by Th17 cells, has a critical, first-line defense in candidiasis by controlling the growth of infecting yeasts as well as by contributing to the host's epithelial integrity in the absence of acquired Th1-type immunity. The two pathways are reciprocally regulated, and IL-22 is upregulated under Th1 deficiency conditions and vice versa. Whereas both IL-17A and F are dispensable for antifungal resistance, IL-22 mediates protection in IL-17RA-deficient mice, in which IL-17A contributes to disease susceptibility. Thus, our findings suggest that protective immunity to candidiasis is made up of a staged response involving an early, IL-22-dominated response followed by Th1/Treg reactivity that will prevent fungal dissemination and supply memory.

Human parainfluenza virus type 2 V protein inhibits interferon production and signaling and is required for replication in non-human primates

In wild-type human parainfluenza virus type 2 (WT HPIV2), one gene (the P/V gene) encodes both the polymerase-associated phosphoprotein (P) and the accessory V protein. We generated a HPIV2 virus (rHPIV2-V^ko) in which the P/V gene encodes only the P protein to examine the role of V in replication in vivo and as a potential live attenuated virus vaccine. Preventing expression of V protein severely impaired virus recovery from cDNA and growth in vitro, particularly in IFN-competent cells. rHPIV2-V^ko, unlike WT HPIV2, strongly induced IFN-β and permitted IFN signaling, leading to establishment of a robust antiviral state. rHPIV2-V^ko infection induced extensive syncytia and cytopathicity that was due to both apoptosis and necrosis. Replication of rHPIV2-V^ko was highly restricted in the respiratory tract of African green monkeys and in differentiated primary human airway epithelial (HAE) cultures, suggesting that V protein is essential for efficient replication of HPIV2 in organized epithelial cells and that rHPIV2-V^ko is over-attenuated for use as a live attenuated vaccine.

[Pelvic masses in young women: a case of giant uterine fibroleiomyomatosis]

The authors reported a particular case of giant uterine fibroleiomyomatosis in young women and describe some clinical feature and differential diagnoses.

P53 and bcl-2 in colorectal cancer arising in patients under 40 years of age: distribution and prognostic relevance

Young people (40 years of age) with colorectal cancer (CRC) represent a distinct subgroup with more aggressive disease behaviour compared to older patients. We evaluate whether p53 and bcl-2 could be useful in identifying young patients at higher risk of tumour progression. We reviewed 1340 CRC patients with 58 patients 40 years (4.2%). They had more frequent moderately or poorly differentiated mucinous adenocarcinomas (26% versus 12.3%, p=0.03); higher advanced stage at diagnosis; shorter 5-year overall survival (49.8% versus 71%; p=0.02); more frequent p53 positive (89.8% versus 72.6%, p<0.05) and bcl-2 negative (88.0% versus 66.2%, p<0.05) tumours; no difference in DNA content or proliferation indexes. Moreover, p53+ and bcl-2- resulted in being independent predictors of survival with shorter survival for the p53+/bcl-2- patients. Combining p53 and bcl-2, we could identify young CRC patients at higher risk of progression, who probably require development of a more sophisticated therapeutic approach based on identification of predictive factors.

State and trait anxiety and depression in patients affected by gastrointestinal diseases: psychometric evaluation of 1641 patients referred to an internal medicine outpatient setting

OBJECTIVES

To evaluate state and trait form of anxiety and current depression in patients affected by gastrointestinal diseases.

METHODS

We studied 1641 outpatients with gastrointestinal disorders, consecutively referred to our Internal Medicine outpatients from 1997 to 2005. State and trait anxiety were assessed by the State and Trait Anxiety Inventory. Current depression was assessed by the Zung self-rating depression scale.

RESULTS

Among patients, 1379 (84.1%) showed state anxiety, 1098 (67%) showed trait anxiety and 442 (27%) showed current depression. The number of gastrointestinal diseases was directly correlated to state anxiety (p < 0.001) and trait anxiety (p = 0.04). Females showed higher levels of anxiety and depression than males (p < 0.001). State anxiety was related to food allergies (p < 0.001), small intestinal bacterial overgrowth (SIBO) (p = 0.001), Hp infection (p = 0.01) and ulcerative colitis in active phase (p = 0.03). Trait anxiety was related to irritable bowel syndrome (IBS) (p < 0.001), Helicobacter pylori (Hp) infection (p = 0.001), food allergies (p = 0.001) and SIBO (p = 0.001). Current depression was related to IBS (p < 0.001) and coeliac disease (p = 0.01), SIBO (p = 0.02). A predicted probability of 0.77 +/- 0.16 to have state anxiety, of 0.66 +/- 0.12 to have trait anxiety and of 0.39 +/- 0.14 to have depression was found in these patients.

CONCLUSIONS

Most of the patients who seek medical consultation for gastrointestinal problems show an associated affective disorder. These patients should be managed by a team including gastroenterologists, psychologists and/or psychiatrists, or by a gastroenterologist having expertise in the treatment of psychological disorders.

[Use of Tachosil in splenectomy in patients with clotting and blood composition disorders]

Splenectomy in patients suffering from onco-haematological conditions presents clotting-related problems which make correct haemostasis more difficult. Using operative haemostasis during splenectomy for onco-haematological conditions as a starting point, the authors report their personal clinical experience of the use of Tachosil, comparing it with other similar products and drawing some personal

CONCLUSIONS

To complete their reflexions on clotting problems during splenectomy in the course of onco-haematological diseases, the comparison with its use in oncological pathologies in other parenchymas, such as the kidney and liver, which also present operative haemostatic difficulties of a technical nature, is pointed out and the soundness of the results indicated. The cases of 3 patients suffering from severe clotting disturbances and treated with splenectomy and 1 patient suffering from clear cell renal carcinoma and subjected to nephrectomy in which Tachosil was used as an aid to haemostasis are reported. In the light of these cases, it can be stated that, albeit with the persistence of difficulties related to the changed clotting capacities resulting from the basic disease, the use of Tachosil has proved effective as an aid in haemostasis and suggests the validity of its use in elective and emergency splenectomy, in these types of patient.

[A surgical emergency: iatrogenic lesion of the spleen. Case report and review of the literature]

The spleen is an organ often injured during surgical procedures. Iatrogenic lesions belong frequently to a low grade and can be treated with a conservative therapy. The surgeon may avoid the splenectomy by using new haemostatic agents as the patch of fibrinogen and thrombin in fixed combination.

Bio-pathological factors of prognostic value in colorectal adenocarcinomas

About 40% of patients bearing a colorectal carcinoma will develop local or distant tumor recurrences. Integrated analyses of biopathological markers, predictive of tumor aggressiveness, may offer a more rational approach to adjuvant therapy planning. To this end we analyzed the correlation between p53 accumulation, bcl-2 expression with cell proliferation, DNA ploidy, and conventional histological parameters, by testing the prognostic significance of these variables in a series of 214 patients bearing a colorectal carcinoma. When these parameters were examined in the univariate analysis, significantly shorter disease free and overall survival were observed in patients bearing p53+ and bcl-2- tumors. In the multivariate analysis p53 accumulation and bcl-2 expression emerged as independent predictors respectively of worse and better clinical outcome also in Dukes' B stage identifying patients at higher risk to develop liver metastases.. These results indicate that in colorectal adenocarcinomas a biological profile, based on the combined evaluation of p53 and bcl-2, can be useful in identifying high risk patients to be enrolled in an adjuvant setting mainly in early stage of the disease.

p53 nuclear accumulation and multiploidy are adverse prognostic factors in surgically resected stage II colorectal cancers independent of fluorouracil-based adjuvant therapy

To identify the prognostically highest risk patients, DNA content and p53 nuclear or cytoplasmic accumulation, evaluated by monoclonal antibody DO7 and polyclonal antibody CM1, were determined in 94 surgically resected stage II (Dukes B2) colorectal cancers, treated or not with adjuvant 5-fluorouracil-based chemotherapy. Sixty-one (65%) of the tumors were aneuploid, 16 (17%) of which had a multiploid DNA content; 50 (53%) displayed DO7 nuclear p53 accumulation, and 44 (47%) showed cytoplasmic CM1 positivity. In multivariate analysis, only multiploidy and p53 nuclear positivity emerged as independent prognostic indicators of a poorer outcome. Positivity for p53 was associated with shorter survival in 5-fluorouracil-treated and untreated patients. Therefore, in patients with Dukes B2 colorectal cancer, a biologic profile based on the combined evaluation of DNA multiploidy and p53 status can provide valuable prognostic information, identifying patients to be enrolled in alternative, more aggressive therapeutic trials.

Evaluation of multiple bio-pathological factors in colorectal adenocarcinomas: independent prognostic role of p53 and bcl-2

About 40% of patients with colorectal carcinoma will develop local or distant tumour recurrences. Integrated analyses of bio-pathological markers, predictive of tumour aggressiveness, may offer a more rational approach to planning adjuvant therapy. To this end, we analysed the correlation between p53 accumulation, Bcl-2 expression, DNA ploidy, cell proliferation and conventional clinico-pathological parameters by testing the prognostic significance of these variables in a series of 171 colorectal carcinoma patients with long-term follow-up. The relationships among the various bio-pathological parameters, analysed by multiple correspondence analysis, showed 2 different clinico-biological profiles. The first, characterised by p53 negativity, Bcl-2 positivity, diploidy, low percentage of cells in S-phase (%S-phase), a low Ki-67 score, is associated with Dukes' A-B stage, well differentiated tumours and lack of relapse. The second, defined by p53 positivity, Bcl-2 negativity, aneuploidy, high %S-phase and elevated Ki-67 score, correlates with Dukes' C-D stage, poorly differentiated tumours and presence of relapse. When these parameters were examined according to Kaplan-Meier's method, significantly shorter disease-free (DFS) and overall survival (OS) were also observed in patients bearing p53 positive and Bcl-2 negative tumours, in Dukes' B stage. In multivariate analysis, p53 accumulation and Bcl-2 expression emerged as independent predictors of a worse and better clinical outcome, respectively. Our results indicate that, in colorectal adenocarcinomas, a biological profile, based on the combined evaluation of p53 and Bcl-2, may be useful for identifying high risk patients to be enrolled in an adjuvant setting, mainly in an early stage of the disease. Int. J. Cancer (Pred. Oncol.) 84:545-552, 1999.

Increase of BCNU sensitivity by wt-p53 gene therapy in glioblastoma lines depends on the administration schedule

In this article, we investigated the effect induced by the reintroduction of wild-type p53 (wt-p53) protein on BCNU sensitivity in the ADF glioblastoma line. Using a wt-p53 recombinant adenovirus (Ad-p53), we demonstrated that exogenous wt-p53 expression was able to increase the sensitivity to BCNU in ADF cells. Interestingly, this effect was more evident when Ad-p53 infection was performed after BCNU treatment compared with the opposite sequence. To understand the biological basis of these different behaviors, we analyzed the cell cycle of the differently treated cells. We found that Ad-p53 infection induced a persistent accumulation of cells in the G0/G1 phase while, as expected, BCNU induced a block in the G2-M phase. Ad-p53-->BCNU sequence did not significantly modify the cell cycle profile in respect of Ad-p53 infected cells. In contrast, BCNU-->Ad-p53 sequence provoked G2-M arrest similar to that observed after treatment with BCNU alone, but prevented the later recovery of the cells through the cell cycle, by driving the cells to apoptotic death. These results demonstrate that the administration sequence is important to increase drug sensitivity. To generalize the phenomenon observed on ADF line, the antiproliferative effect of the two different schedules was analyzed on other glioblastoma lines (A172, CRS-A2, U373MG) with different BCNU sensitivity and p53 status. The data obtained confirm that the wt-p53 gene transfer enhances BCNU sensitivity in glioblastoma cells depending on the administration sequence.

The role of multiploidy as unfavorable prognostic variable in colorectal cancer

OBJECTIVE

To analyze the prognostic value of DNA multiploidy in a prospective study on frozen surgical tissue samples from primary colorectal cancer.

SUMMARY BACKGROUND DATA

Survival data from eleven prospective studies collectively comprising about thirteen hundred patients showed that aneuploidy correlated with a 5-year disease-free survival (DFS) significantly poorer than diploidy, and showed the limited prognostic value of results from retrospective studies employing paraffin-embedded material.

METHODS

Multiple tumor samples of fresh/frozen surgical tissues from 120 colorectal cancer patients who had undergone radical surgery were taken for flow cytometric analysis of DNA content, and proliferative activity, shown as percentage of cells in S-phase (%S). The minimum follow-up of this series was 30 months. Univariate and multivariate analyses determined the independent significance of both clinical and biological variable on DFS.

RESULTS

Values of %S equal to or higher than 17.3 correlated with a 5-year DFS poorer than values lower than 17.3 (44.5% vs 85.2% respectively; p = .03), even if only in patients younger than 64. The subgroup with multiploid tumors showed a significantly poorer 5-year DFS (44.5% vs. 62.6% in the non multiploid patients; p = .02). Subgrouping the Dukes'B stage alone by multiploidy, the difference in DFS was much more evident (31.2% vs. 68% respectively; p = .0004) and multivariate analysis showed multiploidy as the only significant variable. Above all, adjuvant therapy did not absolutely modify the unfavorable outcome of the multiploid Dukes'B patients.

CONCLUSIONS

The prospective evaluation of ploidy allowed us to identify a very high-risk subgroup of patients with multiploid tumors. This biological characterization was easy to demonstrate and, above all in node-negative patients, reliable and very effective in terms of prognosis. The presence of multiploidy should result in a more aggressive therapeutic approach in the adjuvant setting.

Destabilization of human serum albumin by polyethylene glycols studied by thermodynamical equilibrium and kinetic approaches

Both polyethylene glycols (PEG) of MW 8,000 and that of 10000 stabilize the native compact state of human albumin showing negative preferential interaction with the protein. Interaction between these polymers and the protein is thermodynamically unfavorable, and becomes even more unfavorable for denatured protein whose surface areas are larger than those of native ones. PEG of low MW 1000 and 4000 did not show steric exclusion, interacting favorably with hydrophobic side chains made available when the protein was unfolded and leading to a stabilization of the unfolded state, which is manifested as a lowering of the thermal transition temperature. Perturbation of the absorption spectrum of albumin by PEGs confirms that at high temperature the polymers preferentially interact with the denatured state of albumin, but is excluded from the native state at low temperature. This observation is consistent with the fact that PEG is hydrophobic in nature and may interact favorably with the hydrophobic side chain exposed upon unfolding. The lower activation energy for thermal unfolding in the presence of PEG 1000 is in favour of preferential interaction of this polymer with human albumin. PEG of low MW favours the ionization of the tyrosine residues of albumin. It is apparent that pKa decreased with the increase in MW of synthetic polymer. Such variation might be a consequence of the change in dielectric constant at the domain of the protein by PEG binding.