Genetic variability in phlebotomine sandflies: possible implications for Leishmaniasis epidemiology

The vast majority of genetic studies of phlebotomine sandflies have had as their goal the resolution of taxanomic problems. In this paper, Gregory Lanzaro and Alon Warburg summarize the literature describing levels of genetic polymorphism, both within and between sandfly species, and speculate on the significance of variability in the vector to the complex epidemiology of leishmaniasis.     

MMP/TIMP expression profiles in distinct lung disease models: implications for possible future therapies

Background

There is currently a vast amount of evidence in the literature suggesting that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are involved in the pathogenesis of inflammatory airways diseases, such as asthma and COPD. Despite this, the majority of reports only focus on single MMPs, often only in one model system. This study aimed to investigate the profile of an extensive range of MMP/TIMP levels in three different pre-clinical models of airways disease. These models each have a different and very distinct inflammatory profile, each exhibiting inflammatory characteristics that are similar to that observed in asthma or COPD. Since these models have their own characteristic pathophysiological phenotype, one would speculate that the MMP/TIMP expression profile would also be different.

Methods

With the use of designed and purchased MMP/TIMP assays, investigation of rat MMP-2, 3, 7-14 and TIMP-1-4 mRNA expression was undertaken by Real Time PCR. The three rodent models of airways disease investigated were the endotoxin model, elastase model, and the antigen model.

Results

Intriguingly, we demonstrated that despite the distinct inflammatory profile observed by each model, the MMP/TIMP expression profile is similar between the models, in that the same MMPs/TIMPs were observed to be generally increased or decreased in all three models. It could therefore be speculated that in a particular disease, it may be a complex network of MMPs, rather than an individual MMP, together with inflammatory cytokines and other mediators, that results in the distinct phenotype of inflammatory diseases, such as asthma and COPD.

Conclusion

We believe our data may provide key information necessary to understand the role of various MMPs/TIMPs in different inflammatory airway diseases, and aid the development of more selective therapeutics without the side effect profile of current broad-spectrum MMP inhibitors.     

Pooled umbilical cord blood as a possible universal donor for marrow reconstitution and use in nuclear accidents

Human umbilical cord blood has been shown to be an effective source of stem cells for marrow reconstitution in pediatric patients. Unfortunately, the quantity of stem cells obtained from an individual donor can be quite limited in both the total volume and the numbers of stem cells per ml of cord blood. HLA matching further limits the availability, but recent publications indicate close matching may be unnecessary. Therefore, if cord blood from different donors can be combined, larger numbers of stem cells can be available for clinical use provided pooling does not produce a negative effect. Storage of single cord blood specimens at 4 degrees C for 10-21 days in gas permeable bags produced an apparent increase in the percentage of immature cells (CD34, CD117, GPA) and mitotic activity (S+G2/M cells) over day 1. With similar storage of pooled specimens there was a further increase in the number of immature colonies cultured, CD34, CD117, GPA, S+G2/M cells. In addition, nucleated red blood cells increased over the mean values obtained from single cord blood samples. Our previous studies have indicated that large numbers of human mononuclear cells are necessary to reconstitute an irradiated animal model. By combining multiple samples of human cord blood, adequate numbers of stem cells could be pooled for use in adults and would provide cells for megadose therapy, including those patients that had accidentally received lethal irradiation.     

SNAREs in mammalian sperm: possible implications for fertilization

Soluble N-ethylmalameide-sensitive factor attachment protein receptor (SNARE) proteins are present in mammalian sperm and could be involved in critical membrane fusion events during fertilization, namely the acrosome reaction. Vesicle-associated membrane protein/synaptobrevin, a SNARE on the membrane of a vesicular carrier, and syntaxin 1, a SNARE on the target membrane, as well as the calcium sensor synaptotagmin I, are present in the acrosome of mammalian sperm (human, rhesus monkey, bull, hamster, mouse). Sperm SNAREs are sloughed off during the acrosome reaction, paralleling the release of sperm membrane vesicles and acrosomal contents, and SNARE antibodies inhibit both the acrosome reaction and fertilization, without inhibiting sperm-egg binding. In addition, sperm SNAREs may be responsible, together with other sperm components, for the asynchronous male DNA decondensation that occurs following intracytoplasmic sperm injection, an assisted reproduction technique that bypasses normal sperm-egg surface interactions. The results suggest the participation of sperm SNAREs during membrane fusion events at fertilization in mammals.     

Fibroblast growth factor family aberrations in cancers: clinical and molecular characteristics

Fibroblast growth factor ligands and receptors (FGF and FGFR) play critical roles in tumorigenesis, and several drugs have been developed to target them. We report the biologic correlates of FGF/FGFR abnormalities in diverse malignancies. The medical records of patients with cancers that underwent targeted next generation sequencing (182 or 236 cancer-related genes) were reviewed. The following FGF/FGFR genes were tested: FGF3, 4, 6, 7, 10, 12, 14, 19, 23 and FGFR1, 2, 3, and 4. Of 391 patients, 56 (14.3%) had aberrant FGF (N = 38, all amplifications) and/or FGFR (N = 22 including 5 mutations and one FGFR3-TACC3 fusion). FGF/FGFR aberrations were most frequent in breast cancers (26/81, 32.1%, p = 0.0003). In multivariate analysis, FGF/FGFR abnormalities were independently associated with CCND1/2, RICTOR, ZNF703, RPTOR, AKT2, and CDK8 alterations (all P < 0.02), as well as with an increased median number of alterations (P < 0.0001). FGF3, FGF4, FGF19 and CCND1 were co-amplified in 22 of 391 patients (5.6%, P < 0.0001), most likely because they co-localize on the same chromosomal region (11q13). There was no significant difference in time to metastasis or overall survival when comparing patients harboring FGF/FGFR alterations versus those not. Overall, FGF/FGFR was one of the most frequently aberrant pathways in our population comprising patients with diverse malignancies. These aberrations frequently co-exist with anomalies in a variety of other genes, suggesting that tailored combination therapy may be necessary in these patients.     

Lysine richness in human snurps - possible sites for electrophilic attacks

Gene-expression strategies are remodeled following exposure to stress. The reactive oxidants and electrophiles generated after stress actually affects the structural and functional properties of different cellular proteins. It is also seen that lysine rich motifs of proteins play crucial role in electrophilic attack and modification. Therefore, this study revealing lysine richness in 5 main human snrups (Small Nuclear Ribonucleoproteins) indicates a possible mechanism of gene regulation under stress. This possibility is highly supported by the findings that surface residues of the molecules were full of lysine rich clusters. Lysine richness is also found to be a highly conserved pattern across the various domains of life indicative of stress adaptation in the prebiotic to biotic world transition. Moreover the modeled structures showed good all atom contacts and minimal outliers.     

Post-Chornobyl thyroid cancers in Ukraine. Report 1: estimation of thyroid doses

About 1.8 EBq of 131I was released into the atmosphere during the Chornobyl accident that occurred in Ukraine on April 26, 1986. More than 10% of this activity was deposited on the territory of Ukraine. Beginning 4-5 years after the accident, an increase in the incidence of thyroid cancer among children, believed to be caused in part by exposure to 131I, has been observed in different regions of Ukraine. A three-level system of thyroid dose estimation was developed for the reconstruction of thyroid doses from 131I for the entire population of Ukrainian children aged 1 to 18 at the time of accident: (1) At the first level, individual doses were estimated for the approximately 99,000 children and adolescents with direct measurements of radioactivity in the thyroid (so-called direct thyroid measurements) performed in May-June of 1986; (2) at the second level, group doses by year of age and by gender were estimated for the population of 748 localities (with 208,400 children aged 1-18 in 1986) where direct thyroid measurements of good quality were performed on some of the residents; and (3) at the third level, group doses by age and by gender were estimated for the population of the localities where no thyroid measurements were made in 1986. The third-level doses were then aggregated over the population of each oblast. Data, models and procedures required for each level of thyroid dose estimation are described in the paper. At the first level, individual doses were found to range up to 27,000 mGy, with geometric and arithmetic means of 100 and 300 mGy, respectively. At the second level, group doses were found to be highest for the younger children (aged 1 to 4 years); doses for the older children (aged 16 to 18 years) were 3.5 times smaller. At the third level, average population-weighted doses were found to exceed 35 mGy in the five northern oblasts closer to the Chornobyl reactor site; to be in the 14- to 34-mGy range in seven other oblasts, Kyiv city and Crimea; and to be less than 13 mGy in all other oblasts.     

Nitric oxide and atherosclerosis: possible implications for therapy

Atherosclerosis and hypercholesterolaemia disturb the endothelium-dependent regulation of the vascular tone by the labile liposoluble radical nitric oxide. This defect predisposes to vasospasm and ischaemia, with anginal pain as a clinical manifestation. It is now appreciated that endothelial dysfunction is an early event in atherogenesis, possibly also involving the microcirculation, in which atherosclerosis does not develop. Furthermore, it is becoming clear that nitric oxide, in addition to regulating vasomotion, might also modulate the progression of the disease process. The latter notion could have therapeutic implications.     

Cycloheximide insensitive nuclear protein synthesis partially suppressed by chloramphenicol: Some possible implications in the evolution of eukaryotes

• 1.1. Cycloheximide-resistant nuclear protein synthesis that is almost completely suppressed by puromycin and partially inhibited by chloramphenicol can be demonstrated with the use of a mutant Chinese hamster ovary cell line exhibiting a temperature-sensitive defect in cytoplasmic non-mitochondrial protein synthesis.
• 2.2. For a number of reasons, mitochondria are unlikely to be the source of chloramphenicol-sensitive cycloheximide-resistant nuclear protein synthesis.
• 3.3. The existence of nuclear protein synthesis that is unaffected by cycloheximide and partially inhibited by chloramphenicol raises a number of questions about the evolution of eukaryotic cell nuclei.

     

Genetic control of seed weight in flax (Linum usitatissimum) and possible implications

Summary Mean seed weight data were obtained from the F₁ and F₂ of a six-by-six diallel cross with flax (Linum usita-tissimum L.). Pronounced reciprocal differences appeared in the F₁, but had largely disappeared by the F₂. The genetic control of mean seed weight was examined using two types of analysis of variance. The models underlying both analyses were fitted to the data by matrix methods supplying weighted least-squares estimates of the parameters in the models. Weights, the use of which dealt with the problem of variation in the reliability of means, were the reciprocals of the variances of individual cell (cross/self) means in the diallel data table. Elimination of redundant parameters supplied the minimum adequate models for each analysis type. Dominance was apparently masked by the large transient maternal effects in the F₁, but surfaced in the F₂, where dominance was towards larger mean seed weight. This may be coupled with findings elsewhere of possible advantages for larger seed weights to speculate on a role in preserving infrequent hybrid progeny among inbreeding (flax) species. Maternal effects producing larger seed size, plus dominance with the same result might be valuable, in conjunction with growth and competitive advantages conferred by larger seed, in preventing early elimination of rare hybrids.     

Spermine metabolism and radiation-derived reactive oxygen species for future therapeutic implications in cancer: an additive or adaptive response

Destruction of cells by irradiation-induced radical formation is one of the most frequent interventions in cancer therapy. An alternative to irradiation-induced radical formation is in principle drug-induced formation of radicals, and the formation of toxic metabolites by enzyme catalyzed reactions. Thus, combination therapy targeting polyamine metabolism could represent a promising strategy to fight hyper-proliferative disease. The aim of this work is to discuss and evaluate whether the presence of a DNA damage provoked by enzymatic ROS overproduction may act as an additive or adaptive response upon radiation and combination of hyperthermia with lysosomotropic compounds may improve the cytocidal effect of polyamines oxidation metabolites. Low level of X-irradiations delivers challenging dose of damage and an additive or adaptive response with the chronic damage induced by spermine oxidase overexpression depending on the deficiency of the DNA repair mechanisms. Since reactive oxygen species lead to membrane destabilization and cell death, we discuss the effects of BSAO and spermine association in multidrug resistant cells that resulted more sensitive to spermine metabolites than their wild-type counterparts, due to an increased mitochondrial activity. Since mammal spermine oxidase is differentially activated in a tissue specific manner, and cancer cells can differ in term of DNA repair capability, it could be of interest to open a scientific debate to use combinatory treatments to alter spermine metabolism and deliver differential response.     

The nuclear targeting and nuclear retention properties of a human DNA repair protein O6-methylguanine-DNA methyltransferase are both required for its nuclear localization: the possible implications.

Human O6-methylguanine-DNA methyltransferase (MGMT) protects human cells from the mutagenic effects of alkylating agents by repairing the O6-alkylguanine residues formed by these agents in the nuclear DNA. We report here a study showing a possible two-step model for the nuclear localization of the 21 kDa human protein. The first step is the translocation of the protein from the cytosol to the nucleus. This appears to require the nuclear targeting property associated with the holoprotein in combination with a cellular factor(s) to effect the nuclear translocation of MGMT. The second step involves the nuclear retention of MGMT (to prevent its export from the nucleus). This requires a basic region (PKAAR, codons 124-128) that can bind to the non-diffusible DNA elements in the nucleus. Supporting data for such mechanisms are: (i) the holoprotein can target the cytosolic 110 kDa beta-galactosidase into the nucleus; (ii) purified recombinant MGMT requires a cellular factor for transport across the nuclear membrane; (iii) nuclear MGMT can be removed selectively by DNase I; (iv) the repair-positive K125L mutant, which alters the PKAAR motif, remains in the cytosol and fails to bind DNA in vitro; and (v) polypeptide containing the PKAAR motif has no nuclear targeting property. Interestingly, mutants in another basic region, KLLKVVK (codons 101-107) are DNA binding and repair deficient but entirely nuclear. As these substitutions affect the functional properties of human MGMT, they are potential targets for genetic screening of individuals for risk assessment to alkylating agents.     

The binary presence or absence of lymph node metastasis or extrathyroidal extension is not associated with survival in papillary thyroid cancers: Implications for staging systems

BackgroundThe characteristics of diagnosed papillary thyroid cancer (PTC) have changed over time with the increasing trend of early diagnosis, and the survival impact of conventional prognostic factors such as lymph node metastasis (LNM) and extrathyroidal extension (ETE) is controversial. We investigated PTC prognostic factors for overall survival (OS) and disease specific survival (DSS), focusing on LNM, ETE, and their implications for PTC staging systems.MethodsWe assessed prognostic factors for OS and DSS in a nationwide sample of Korean PTC patients (N = 5192, median follow-up 121 months) using Cox regression. The binary presence or absence of LNM and ETE, as well as other measures of LNM and ETE, were examined for their survival impact. We also evaluated the relative performance of PTC staging systems before and after revising the staging criteria for LNM and ETE.ResultsThe binary presence of LNM or ETE was not a prognostic factor for OS or DSS, nor were other various measures of LNM. However, the extent of ETE as none, microscopic, or gross independently influenced survival (OS hazard ratio for gross vs. none: 3.28, 95% confidence interval (CI) 1.97–5.46; DSS hazard ratio for gross vs. none: 3.75, 95% CI 1.59–8.81). The performance of PTC staging systems improved when the extent of ETE and/or location of LNM were used as staging components.ConclusionThe extent of ETE and/or location of LNM may be better survival indicators than their binary presence or absence, and we propose staging criteria revisions to pertinent staging systems to better reflect the contemporary PTC population.     

Cervical cancer screening in Mediterranean countries: implications for the future

K. Syrjänen, L. Di Bonito, L. Gonçalves, L. Murjal, M. Santamaria, V. Mahovlic, P. Karakitsos, B. Önal and F. C. Schmitt Cervical cancer screening in Mediterranean countries: implications for the future Prompted by feedback from the 34th European Congress of Cytology (ECC), the practice of including a special symposium in the programme was continued in the 35th ECC in Lisbon (2009) by arranging a satellite symposium entitled ‘Cervical Cancer Screening in the Mediterranean Countries’. Because of the importance to the future of this discipline, it was felt appropriate to summarize the highlights of this symposium here. Cervical cancer prevention strategies in the countries participating in the symposium (Portugal, Spain, Italy, Croatia, Greece and Turkey) appear to be highly variable. As yet, none of these countries can demonstrate a fully implemented national screening programme, but all are in different phases of designing and/or setting up such a programme, which is important. At present, the time‐honoured concept of cervical cancer prevention by Pap smear screening is under review, because prophylactic human papillomavirus (HPV) vaccines demonstrate a potential to prevent the vast majority (albeit not all) of cases of cervical cancer in the foreseeable future. Cervical cancer screening is still needed in this emerging era of HPV vaccination, but clearly the existing screening strategies must be modified to provide a cost‐effective combination of vaccination and screening. If the currently evaluated new screening strategies, such as HPV testing followed by cytology triage, become a reality, there is the likelihood that the Pap test will have only a secondary role, subordinate to HPV testing. Supporters of this scenario claim that Pap test performance will deteriorate in vaccinated populations. Reduced positive predictive value (PPV), due to lower disease prevalence, is inevitable, however, and this would also affect HPV tests. Any decline in sensitivity and specificity depends on human performance, and as such is avoidable by taking appropriate preventive measures. As clinical cytologists, we should focus attention on minimizing the risk to the Pap test of falling sensitivity because of unfamiliarity with abnormal cells, and also of reduced specificity if the fear of missing significant disease leads to overcalling of benign abnormalities.