Distribution of surgical hydatidosis in Tunisia, results of 2001-2005 study and trends between 1977 and 2005

We have performed an exhaustive retrospective study in all surgical wards (54 services in 35 hospitals) which usually carry out surgical treatment of hydatic cysts in the country, covering the period between January 2001 and December 2005, in order to determine the annual surgical incidence of human cystic hydatidosis in Tunisia. A total of 6249 surgical interventions were recorded during the period 2001-2005. The highest proportion was recorded in the hospitals of Tunis District (42.9%). The service of thoracic surgery from Ariana hospital occupies the first rank (95%). The yearly incidence rate varies between 11 and 13.6 per 100,000. Calculated over the 5 years period, the incidence rate is 63.2 per 100,000 inhabitants, which means an average yearly incidence rate of 12.6 per 100,000 [12.28-12.99]. Governorates of the North West and the Western Central regions of the country are the most endemic area with an average annual incidence rates varying between 19.2 and 33.9 per 100,000, which is at least once and half higher than the national level. After 30 years (1977-2005), the average annual incidence rate slightly dropped, from 15 to 12.6 per 100,000, proving that such zoonosis remains a problem of public health in Tunisia. In order, to control in more or less short term this heavy burden disease and public health expenditure, the only efficient way is the prevention of the diseases with a mass treatment campaign of dogs, principal host of the parasite.     

Comparative study of Cyperus rotundus essential oil by a modified GC/MS analysis method. Evaluation of its antioxidant, cytotoxic, and apoptotic effects

Gas chromatography coupled with mass spectrometry (GC/MS), using both electron impact (EI) and chemical ionization (CI) detection modes on apolar and polar stationary phases, led to the determination of the volatile composition of the essential oil obtained from tubers of Cyperus rotundus (Cyperaceae). In this study, more than 33 compounds were identified and then compared with the results obtained in our previous work. Cyperene, alpha-cyperone, isolongifolen-5-one, rotundene, and cyperorotundene were the principal compounds comprising 62% of the oil. An in vitro cytotoxicity assay with MTT indicated that this oil was very effective against L1210 leukaemia cells line. This result correlates with significantly increased apoptotic DNA fragmentation. The oxidative effects of the essential oil were evaluated using the 1,1-diphenyl-2-picrylhydrazyl (DPPH), xanthine/xanthine oxidase assays, and the scavenging of superoxide radical assay generated by photo-reduction of riboflavin. The antimutagenic activity of essential oil has been examined by following the inhibition of H(2)O(2) UV photolysis which induced strand-break formation in pBS plasmid DNA scission assay. Based on all these results, it is concluded that C. rotundus essential-oil composition established by GC/MS analysis, in EI- and CI-MS modes, presents a variety of a chemical composition we were not able to detect with only GC/MS analysis in our previous work. This essential oil exhibited antioxidant, cytotoxic, and apoptotic properties.     

Identification of different isoforms of 14-3-3 protein family in human dermal and epidermal layers

We have previously demonstrated a high level of stratifin, also known as 14-3-3 sigma in differentiated keratinocyte cell lysate and conditioned medium (CM). In this study, we asked the question of whether other 14-3-3 isoforms are expressed in human dermal fibroblasts, keratinocytes, intact dermal and epidermal layers of skin. In order to address this question, total proteins extracted from cultured cells or skin layers were subjected to western blot analysis using seven different primary antibodies specific to well-known mammalian isoforms, beta, gamma, epsilon, eta, sigma, tau, and zeta of 14-3-3 protein family. The autoradiograms corresponding to each isoform were then quantified and compared. The results revealed the presence of very high levels of all seven isoforms in cultured keratinocyte and conditioned medium. With the exception of tau isoform, other 14-3-3 isoforms were also present in intact epidermal layer of normal skin. The profile of 14-3-3 proteins in whole skin was similar to that of epidermis. In contrast, only gamma 14-3-3 isoform, was present in dermal layer obtained from the same skin sample. On the other hand, cultured fibroblasts express a high level of beta, epsilon, gamma and eta and a low level of zeta and tau, but not sigma isoform. However, the levels of 14-3-3 epsilon, gamma and eta were barely detectable in fibroblast conditioned medium. Further, we also used immunohistochemical staining to identify the 14-3-3 isoform expressing cells in human skin sections. The finding revealed different expression profile for each of these isoforms mainly in differentiated keratinocytes located within the layer of lucidum. However, fibroblasts located within the dermal layer did not show any detectable levels of these proteins. In conclusion, all members of 14-3-3 proteins are expressed by cells of epidermal but not dermal layer of skins and that these proteins are mainly expressed by differentiated keratinocytes.     

Molecular evolution of chloroplast DNA in fig (Ficus carica L.): Footprints of sweep selection and recent expansion

Here, we report the nucleotide variation in two non-coding regions of the chloroplast DNA (cpDNA) to construct a possible evolutionary scenario in Ficus carica L. Our results suggest the occurrence of haplotypic and nucleotide diversity with a large variation level of chloroplast non-coding regions. Furthermore, our results demonstrated an explicit rejection of the null hypothesis that within F. carica the intron trnL and the spacer trnL-trnF evolved under a strictly neutral model of molecular evolution. Although, recent population expansion could serve as one alternative explanation for the detected excess of singleton, our results imply a positive selection and the genetic hitchhiking effect is unlikely. Parameters performed supported scenario of sweep selection and recent expansion of F. carica across Tunisia. Our results indicate that both positive selection and demographic histories have jointly contributed to the observed patterns of nucleotide diversity and haplotypes structure. Based on the results, we characterize the fig resources and provide several suggestions for effective conservation and improvement programs.     

Effects of mycorrhizal fungi inoculation and soil amendment with hydrogel on leaf anatomy,growth and physiology performance of olive plantlets under two contrasting water regimes

Abiotic stresses present a real environmental problem in agriculture field. In our paper, we examine the significance of arbuscular mycorrhizal fungi (AMF) and soil amendment with water retaining superpolymers (hydrogel) on growth and physiology performance of olive plantlets. Our experiment was carried out in nursery conditions, to test the impact of hydrogel (TH) and mycorrhizal fungi (TM), used individually or combined (THM), and compare them with non inoculated plants (TC), to understand and reduce the water stress damage in olive plantlets (cv. Chemlali). We also evaluate interactions between hydrogel, mycorrhizal treatments and water regimes. Results of mycorrhization (M%) show that roots colonized by Rhizophagus irregularis of well-watered plants were about 40.87%. In combined treatment (THM), M% was about 32.14%. Compared to TC treatment, TM treatment enhances significantly the dry weights of the whole plant under the two water regimes. The TM treatment had the highest relative water content (66.50%) and Chl (a?+?b) (0.83 mg g^??1) in stressed conditions. We found also that under water stress, the maximal quantum efficiency of the photosystem II measurements in leaves were significantly improved by 50.70% in TH treatment compared to control. For phenolic contents, TH treatment decreased significantly total phenols by 50.10% compared to TC. Our study gives evidence that the use of AMF and the hydrogel separately or in combination may enhance the capacity to avoid drought damages of olive plantlets and improve olive performances.     

Identification of winter moth (Operophtera brumata) refugia in North Africa and the Italian Peninsula during the last glacial maximum

Numerous studies have shown that the genetic diversity of species inhabiting temperate regions has been shaped by changes in their distributions during the Quaternary climatic oscillations. For some species, the genetic distinctness of isolated populations is maintained during secondary contact, while for others, admixture is frequently observed. For the winter moth (Operophtera brumata), an important defoliator of oak forests across Europe and northern Africa, we previously determined that contemporary populations correspond to genetic diversity obtained during the last glacial maximum (LGM) through the use of refugia in the Iberian and Aegean peninsulas, and to a lesser extent the Caucasus region. Missing from this sampling were populations from the Italian peninsula and from North Africa, both regions known to have played important roles as glacial refugia for other species. Therefore, we genotyped field‐collected winter moth individuals from southern Italy and northwestern Tunisia—the latter a region where severe oak forest defoliation by winter moth has recently been reported—using polymorphic microsatellite. We reconstructed the genetic relationships of these populations in comparison to moths previously sampled from the Iberian and Aegean peninsulas, the Caucasus region, and western Europe using genetic distance, Bayesian clustering, and approximate Bayesian computation (ABC) methods. Our results indicate that both the southern Italian and the Tunisian populations are genetically distinct from other sampled populations, and likely originated in their respective refugium during the LGM after diverging from a population that eventually settled in the Iberian refugium. These suggest that winter moth populations persisted in at least five Mediterranean LGM refugia. Finally, we comment that outbreaks by winter moth in northwestern Tunisia are not the result of a recent introduction of a nonnative species, but rather are most likely due to land use or environmental changes.     

Beta-amyloid peptides stimulate endozepine biosynthesis in cultured rat astrocytes

Accumulation of beta-amyloid peptide (Abeta), which is a landmark of Alzheimer's disease, may alter astrocyte functions before any visible symptoms of the disease occur. Here, we examined the effects of Abeta on biosynthesis and release of diazepam-binding inhibitor (DBI), a polypeptide primarily expressed by astroglial cells in the CNS. Quantitative RT-PCR and specific radioimmunoassay demonstrated that aggregated Abeta(25-35), at concentrations up to 10(-4) m, induced a dose-dependent increase in DBI mRNA expression and DBI-related peptide release from cultured rat astrocytes. These effects were totally suppressed when aggregation of Abeta(25-35) was prevented by Congo red. Measurement of the number of living cells revealed that Abeta(25-35) induced a trophic rather than a toxic effect on astrocytes. Administration of cycloheximide blocked Abeta(25-35)-induced increase of DBI gene expression and endozepine accumulation in astrocytes, indicating that protein synthesis is required for DBI gene expression. Altogether, the present data suggest that Abeta-induced activation of endozepine biosynthesis and release may contribute to astrocyte proliferation associated with Alzheimer's disease.     

RNase P ribozymes selected in vitro to cleave a viral mRNA effectively inhibit its expression in cell culture

An in vitro selection procedure was used to select RNase P ribozyme variants that efficiently cleaved the sequence of the mRNA encoding thymidine kinase of herpes simplex virus 1. Of the 45 selected variants sequenced, 25 ribozymes carried a common mutation at nucleotides 224 and 225 of RNase P catalytic RNA from Escherichia coli (G(224)G(225) --> AA). These selected ribozymes exhibited at least 10 times higher cleavage efficiency (k(cat)/K(m)) than that derived from the wild type ribozyme. Our results suggest that the mutated A(224)A(225) are in close proximity to the substrate and enhance substrate binding of the ribozyme. When these ribozyme variants were expressed in herpes simplex virus 1-infected cells, the levels of thymidine kinase mRNA and protein were reduced by 95-99%. Our study provides the first direct evidence that RNase P ribozyme variants isolated by the selection procedure can be used for the construction of gene-targeting ribozymes that are highly effective in tissue culture. These results demonstrate the potential for using RNase P ribozymes as gene-targeting agents against any mRNA sequences, and using the selection procedure as a general approach for the engineering of RNase P ribozymes.     

The spectrum of pathogenic bacteria in positive blood cultures

There is compelling evidence to suggest that the profiles of pathogenic bacteria which cause septicaemia shock vary from one region to another due to differences in the source of contamination. Blood cultures were prepared from 3,481 patients with symptoms of systemic bacterial contamination. The blood cultures of 558 (16.02%) patients showed at least one kind of bacterial infection. This rate was markedly higher than that reported in Germany (12.8%) and Japan (12.3%). Systemic bacterial infection was significantly higher in males than in females (82% versus 18%). Most of the patients surveyed (62%) were adults and the rest were either infants (19%) or neonates (19%). When blood samples of these patients were cultured, and isolated bacteria were characterized by a variety of diagnostic tests, over twenty different strains of bacteria were identified and characterized. More than 29% of positive cultures were Enterobacter spp. while Staphylococcus aureus (20%) and Brucella spp. (8%) ranked second and third highest among the infections. The results suggest that agents which cause infections vary with respect to region and that knowledge of local risk factors may aid in patient diagnosis and treatment.     

Managing the risk of cancer in Cowden syndrome: a case report

ABSTRACT: INTRODUCTION: Cowden syndrome is a rare cancer predisposition syndrome inherited in an autosomaldominantfashion. The syndrome is characterized by hamartomatous polyps that affectmultiple organs: skin, mucous membranes, thyroid, breast, gastrointestinal tract,endometrium and brain. It is also associated with an increased risk of developing malignancyin many tissues but especially breast, thyroid and endometrium. CASE PRESENTATION: We present the case of a 30-year-old Tunisian woman with mental retardation who presentedto our facility with rectal hamartomatous polyps. Her medical history included fibrocysticdisease of the breast over the last three years. A physical examination revealed macrocephaly,hyperkeratotic papules on the mid-facial skin, palmoplantar keratosis and oral mucosalpapillomatosis. A breast examination revealed nodular breast tissue bilaterally and a diffusethyroid goiter. Our patient was clinically euthyroid. A total thyroidectomy was performed. Ahistopathologic examination revealed thyroid papillary carcinoma. A gastrointestinalevaluation revealed esophageal and gastric polyps. Biopsies showed hyperplastic andadenomatous lesions associated with Helicobacter pylori. A final diagnosis of Cowdensyndrome was made according to the syndrome testing criteria adapted by the US NationalComprehensive Cancer Network. A prophylactic bilateral mastectomy was proposed butrefused by our patient. Our patient was kept under surveillance for breast and colorectalmalignancies. CONCLUSIONS: Early and accurate diagnosis of Cowden syndrome is essential because it is a cancerpredisposition syndrome that carries an increased risk for developing malignancy in manytissues, especially breast and thyroid. For this reason, education regarding the signs andsymptoms of cancer is important. All patients must be screened for malignancies and optionsfor prophylactic mastectomy should be discussed. Guidelines for cancer screening includingsurveillance and management plans for these patients should be distinguished from those ofthe general population, and may lead to a more timely diagnosis and treatment of cancersassociated with this syndrome.