High order DNA structure as inferred by optical fluorimetry and scanning calorimetry

New quantitative insights on the native high order chromatin-DNA structure existing within interphase nuclei are obtained by monitoring the effects of two common well-characterized fixatives, glutaraldehyde and ethanol/acetic acid mixture, at the level of the intranuclear DNA distribution and structures. Reproducible distinct levels of DNA fluorescence intensity and their intranuclear distribution are apparent in unfixed and fixed thymocytes by using DAPI and quantitative optical microscopy based on a charge coupled device. The fluorescent histograms correlated with the calorimetric thermograms on the very same thymocytes fixed and unfixed, establish an unequivocal baseline for the different levels of structural organization of the chromatin within the intact nucleus; namely their number, DNA packing ratio and fiber diameter. A systematic comparison among all the numerous models, being so far proposed for the quinternary and quaternary levels of DNA folding, to identifies the rope or ribbon-like and the chromonema as the ones that best fit with the in situ distribution. This revised version was published online in June 2006 with corrections to the Cover Date.     

Evolution of the hydrogenosome

Since its discovery almost 25 years ago the enigmatic hydrogenosome, a redox organelle of anaerobic unicellular eukaryotes, has puzzled evolutionists as to its origin and function. Synthesis of recent molecular, physiological and morphological studies now favours the hypothesis that hydrogenosomes derived from a modification of pre-existing mitochondria, and argues against the previously held view that the hydrogenosome had a polyphyletic origin. These data provide evidence for a more ancient origin of mitochondria than hitherto thought.     

Genetic and physical mapping of the Chediak-Higashi syndrome on chromosome 1q42-43.

The Chediak-Higashi syndrome (CHS) is a severe autosomal recessive condition, features of which are partial oculocutaneous albinism, increased susceptibility to infections, deficient natural killer cell activity, and the presence of large intracytoplasmic granulations in various cell types. Similar genetic disorders have been described in other species, including the beige mouse. On the basis of the hypothesis that the murine chromosome 13 region containing the beige locus was homologous to human chromosome 1, we have mapped the CHS locus to a 5-cM interval in chromosome segment 1q42.1-q42.2. The highest LOD score was obtained with the marker D1S235 (Zmax = 5.38; theta = 0). Haplo-type analysis enabled us to establish D1S2680 and D1S163, respectively, as the telomeric and the centromeric flanking markers. Multipoint linkage analysis confirms the localization of the CHS locus in this interval. Three YAC clones were found to cover the entire region in a conting established by YAC end-sequence characterization and sequence-tagged site mapping. The YAC contig contains all genetic markers that are nonrecombinant for the disease in the nine CHS families studied. This mapping confirms the previous hypothesis that the same gene defect causes CHS in human and beige pheno-type in mice and provides a genetic framework for the identification of candidate genes.     

Transfer factor with anti-EBV activity as an adjuvant therapy for nasopharyngeal carcinoma: A pilot study

Overall survival of nasopharyngeal carcinoma (NPC) at UICC stage IV still remains unsatisfactory even with combination chemotherapy (CT) and radio-therapy (RT). In view of the association of reactivation of Epstein-Barr virus (EBV) with the development and recurrence of NPC, immunotherapy in the form of transfer factor (TF) with specific activity against EBV (TF-B1) was suggested as an adjuvant to a combination of CT and RT in order to improve survival. In the present study, 6 UICC Stage IV patients received TF-B1 and another 6 patients matched for disease stage were given TF prepared from peripheral blood leucocytes (TF-PBL). Results were compared with another 18 patients matched by age, sex, and stage of disease who received standard therapy without TF during the same period (C group). After a median follow up of 47.5 months, the survival for the TF-B1 group was found to be significantly better (P=<0.05) than the PBL and C group. While the 8 patients with distant metastasis (DM), not treated with TF-B1 (6 in the control and 2 in the PBL group), died due to progressive disease (average survival being 14.3 months), both patients with DM in the TF-B1 group had complete remission: one died of tuberculosis after surviving for 3.5 years and another is still alive, disease free, after 4.2 years. Although the series involved a small number of cases, the apparent effect of adjuvant immunotherapy in the form of TF with anti-EBV activity is of considerable interest.     

N-Acetylcysteine as an antioxidant and disulphide breaking agent: the reasons why

The main molecular mechanisms explaining the well-established antioxidant and reducing activity of N-acetylcysteine (NAC), the N-acetyl derivative of the natural amino acid l-cysteine, are summarised and critically reviewed. The antioxidant effect is due to the ability of NAC to act as a reduced glutathione (GSH) precursor; GSH is a well-known direct antioxidant and a substrate of several antioxidant enzymes. Moreover, in some conditions where a significant depletion of endogenous Cys and GSH occurs, NAC can act as a direct antioxidant for some oxidant species such as NO₂ and HOX. The antioxidant activity of NAC could also be due to its effect in breaking thiolated proteins, thus releasing free thiols as well as reduced proteins, which in some cases, such as for mercaptoalbumin, have important direct antioxidant activity. As well as being involved in the antioxidant mechanism, the disulphide breaking activity of NAC also explains its mucolytic activity which is due to its effect in reducing heavily cross-linked mucus glycoproteins. Chemical features explaining the efficient disulphide breaking activity of NAC are also explained.     

An environmental and economic analysis of the wood-pellet chain: two case studies in Southern Italy

Purpose

Wood pellet heating systems are considered as an essential component of European plans to reduce greenhouse gas (GHG) emissions. The goal of this analysis was to estimate and compare the environmental impacts and the costs of the production of packed wood pellets. Two pellet production systems, using roundwood logs (case 1) and mainly sawdust (case 2), have been analysed in 2015 in Basilicata region (Southern Italy).

Methods

A life cycle assessment (LCA) analysis was applied to calculate the environmental impact indicators of each system, whilst a life cycle cost (LCC) analysis was implemented to evaluate the pellets’ cost production. Hence, the functional unit chosen was 1 t of produced pellets. The system boundaries considered for the purpose of the current investigation were from the tree felling to the pellet packaging. In particular, the following activities were considered: motor-manual felling and delimbing with a chainsaw, timber yarding with a tractor along the forest track, loading and transportation of the logs to the collection point, transportation of timber to the factories for a distance of 35 km, pellet production and pellet packaging in low-density polyethylene bags with a total weight of 15 kg bag^?1.

Results and discussion

The production of 1 t of pellets emitted about 83 kg of CO₂eq in case 1 and 38 kg in case 2. In addition, 2.7 kg of SO₂eq and 0.005 kg of PO³ ₄-eq were produced in case 1 and 1.4 kg of SO₂eq and 0.002 kg of PO³ ₄-eq in case 2. Mineral extraction was equal to 0.9 MJ surplus energy in both cases. Case 1 led to higher environmental impacts (about 50% more), essentially for the operation of pelletisation, and in particular for the higher consumption of electricity that characterised it, whereas the production costs were 172 and 113 € t^?1 in case 1 and case 2, respectively. In both study cases, consumption costs (costs for raw material, electricity consumption, fuel usage) were the most important cost items.

Conclusions

Our studies highlight how, in both cases, the operations carried out in the forest produced the minor part of the environmental impact but, at the same time, were the most expensive operations. Further, our studies show how mixing lumbering by-products (sawdust) and forest management products (lumbers) can be an efficient solution to reduce both manufacturing costs and environmental impacts to produce wood pellets.

     

Two genes are responsible for Griscelli syndrome at the same 15q21 locus

Griscelli syndrome is a rare autosomal recessive disease characterized by pigment dilution, variable cellular immunodeficiency, and an acute phase of uncontrolled T lymphocyte and macrophage activation. We previously mapped the disease locus to 15q21 and showed that a MyoVa gene (HGMW-approved symbol MYO5A) defect leads to Griscelli syndrome. We report a second MyoVa mutation in a new patient, confirming this first finding. However, in four other Griscelli syndrome patients analyzed, the MYOVA protein is expressed, and no mutation can be detected in the MyoVa gene coding sequence, even in the alternatively spliced region for which exon-intron boundaries were characterized. Linkage analysis performed in 15 Griscelli families thus far studied confirms the first localization. However, fine haplotype analysis in three families strongly suggests the existence of a second gene at the same locus for Griscelli syndrome less than 7.3 cM distant from the MyoVa gene.     

Blood-related proteomics

Blood-related proteomics is an emerging field, recently gaining momentum. Indeed, a wealth of data is now available and a plethora of groups has contributed to add pieces to the jigsaw puzzle of protein complexity within plasma and blood cells.In this review article we purported to sail across the mare magnum of the actual knowledge in this research endeavour. The main strides in proteomic investigations on red blood cells, platelets, plasma and white blood cells are hereby presented in a chronological order.Moreover, a glance is given at prospective studies which promise to shift the focus of attention from the end product to its provider, the donor, in a sort of Kantian “Copernican revolution”.A well-rounded portrait of the usefulness of proteomics in blood-related research is accurately given. In particular, proteomic tools could be adopted to follow the main steps of the blood-banking production processes (a comparison of collection methods, pathogen inactivation techniques, storage protocols). Thus proteomics has been recently transformed from a mere basic-research extremely-expensive toy into a dramatically-sensitive and efficient eye-lens to either delve into the depths of the molecular mechanisms of blood and blood components or to establish quality parameters in the blood-banking production chain totally anew.     

<Emphasis Type="Italic">Artemisia arborescens</Emphasis> L. leaf litter: phytotoxic activity and phytochemical characterization

Artemisia arborescens L. is a perennial fast-growing Mediterranean shrub, which releases abundant leaf litter upon soil surface throughout the year. The paper aimed to both evaluate the phytotoxic potential and identify major compounds occurring in the plant leaf litter. Following methanolic maceration of the leaf litter, the crude extract was then sequentially extracted with hexane, chloroform and ethyl acetate through a bio-guided fractionation method. The phytotoxic potential of the methanolic extract and its solvent fractions was assessed in vitro on germination and root growth of two sensitive (Lactuca sativa L., Raphanus sativus L.) and native (Amaranthus retroflexus L., Cynodon dactylon (L.) Pers.) species. Moreover, the most active fractions were chemically characterized by GC–MS and HPTLC analysis. In all species, the physiological processes were highly inhibited by both the methanolic extract and its solvent fractions. Several classes of biologically active phytochemicals such as terpenoids, fatty acids, lignans and phenolic compounds were identified in all fractions. Artemisia arborescens leaf litter could be considered an important source of biologically active phytochemicals, which may have a significant allelopathic impact towards neighbouring species once released into the environment.     

Integrating Cervical Cancer Screening with HIV Care in Cameroon: Comparative Risk Analysis of Cervical Disease in HIV-Infected Women Receiving Antiretroviral Therapy to Women in the General Population

Background

While the effect of highly active antiretroviral therapy (HAART) on natural history of cervical lesions remains controversial, resource limited countries need to understand the relevance of their own data to their settings. We compared the risk of cervical disease in HAART-experienced women with that in women in the general population of Cameroon.

Methods

A retrospective cross sectional survey of women aged 35 years and above, attending a voluntary screening campaign for cervical cancer at the Nkongsamba Regional Hospital in Cameroon between February and May 2014. Squamous intraepithelial lesions (SIL) were determined by Pap smear. Multiple logistic regression was used to compare the odds of SIL in women on HAART to women from the community with unknown HIV status.

Results

Included were 302 women of whom 131(43.4%) were HIV-infected and receiving HAART on the site while 171 (56.6%) were women from the community. Cervical disease was observed in 51(16.9%) persons of whom 15 (11.5%) cases in the HAART group and 36 (21.1%) cases in the general group (p = 0.027). After controlling for age and other covariates, women in the HAART group had a 67% reduction in the odds of cervical lesions compared with the community group [adjusted odd ratio (aOR) = 0.33, 95%CI: 0.15–0.73, p = 0.006).

Conclusion

HIV-infected women receiving HAART have a lower risk of cancer than women in the general population. This finding may not be attributed to HAART alone but to all the health benefits derived from receiving a comprehensive HIV care.