The role of Trichoderma spp. and silica gel in plant defence mechanisms and insect response in vineyard.

Several elicitors, stimulating induced resistance mechanisms, have potential in preventing or mitigating pathogen infections. Some of these compounds, triggering the production of jasmonic acid (JA), a precursor of herbivore-induced plant volatiles, could also play a central role in indirect resistance to pest species, by improving beneficial arthropod performance, and necrotrophic pathogens. In the current work, Trichoderma gamsii/T. asperellum and silica gel treatments - alone and in combination - were studied to evaluate the plant defence mechanism on grapevines (Vitis vinifera L.) by laboratory and field trials. JA production level was measured before and after Plasmopara viticola infection on potted vines. JA production induced by silica gel was higher than that caused by Trichoderma before infection. In Trichoderma-treated plants, JA production increased after P. viticola inoculation. In vineyard field trials, Mymaridae (Hymenoptera: Chalcidoidea) showed higher captures in transparent sticky traps on silica gel-treated plants, in comparison with control. On the other hand, no significant attraction was detected for Ichneumonoidea and other Chalcidoidea in silica gel and T. gamsii/T. asperellum-treated plants. The potential effects of elicitors are discussed, in the frame of attract and reward strategy.

Prevalence of pityriasis versicolor in a group of Italian pregnant women.

BACKGROUND: Although a predisposing role of pregnancy to Malassezia infections is referred, data on the prevalence of pityriasis versicolor (PV) in pregnant women are not available in literature. OBJECTIVE: To investigate the frequency of PV during pregnancy, 60 pregnant women were clinically and microscopically investigated during and after pregnancy. RESULTS: Fifty-two women completed all visits; three women were affected by PV at first or third trimester of pregnancy, and none at 6 months after delivery. Colonization due to Malassezia yeasts was very significantly (P < 0.01) or significantly increased (P < 0.05) at the third trimester and 6 months after delivery, respectively. No variation was observed between the end of pregnancy and the postpartum (P > 0.05). CONCLUSION: Frequency of PV during pregnancy (5.7%) does not seem different from that reported in general population living in temperate climates (2-5%). However, higher degree of colonization by Malassezia resulted at the end of pregnancy and postpartum.

Intermediate stage Hodgkin's disease: preliminary results on 210 patients treated with four ABVD chemotherapy cycles plus extended versus involved field radiotherapy.

BACKGROUND: To improve long-term survival by reducing toxicity in intermediate stage Hodgkin's disease patients, we compared the effects of involved field (IF) versus extended field (EF) irradiation administered after four cycles of ABVD regimen. MATERIALS AND METHODS: Two hundred and ten Hodgkin's disease patients, at clinical stage II with risk factors and III without risk factors, were enrolled in the randomized study HD94. After four courses of ABVD regimen, patients who achieved complete remission (CR) or partial remission (PR) were randomly assigned to the IF or EF arm. The Kaplan-Meier method was adopted to estimate overall survival (OS) and relapse-free survival (RFS). RESULTS: After a median follow-up of 78 months (range 13-111 months), OS was 98% and 96%, respectively, in the EF and IF arms; RFS was 94% and 91%, respectively, in the EF and IF arms. CONCLUSION: We confirm the efficacy of four cycles of ABVD regimen, with suitable dose intensity, and radiotherapy as consolidation therapy, in intermediate stage Hodgkin's disease patients (CR = 99.5% and OS = 95%). We also found that involved field radiotherapy results were as effective as extended field, without acute toxicity.

Hodgkin's disease of the nasopharynx: diagnostic and therapeutic approach with a review of the literature.

The lymphoid tissues of Waldeyer's ring, including the nasopharynx, are rarely involved in Hodgkin's disease (HD). Between March 1977 and July 2001, about 2150 patients affected by HD were observed in our institute; 7 of them (0.32%), all male patients, had HD of the nasopharynx. They had no symptoms and blood tests were normal. All patients were treated with chemotherapy and/or radiotherapy and achieved complete remission. At a median follow-up of 72 months, they are alive and in continuous complete remission. We conclude that Hodgkin's disease of the nasopharynx is a rare and predominantly male disease with a particularly favorable prognosis. Bone marrow biopsy could be avoided. We believe that two to four cycles of a chemotherapeutic regimen and involved field radiotherapy at an intermediate-high dosage (25-30 Gy) could be the first line treatment for these patients.

Induction of erythroid differentiation of human K562 cells by 3-O-acyl-1,2-O-isopropylidene-D-glucofuranose derivatives.

In this paper we report the synthesis of twelve 3-O-acyl-1,2-O-isopropylidene-D-glucofuranose derivatives and the results obtained on their effects in inducing erythroid differentiation of human leukemic K562 cells. The data obtained demonstrate that two of the newly synthetized compounds are able to induce erythroid differentiation of K562 cells. In addition, these same compounds potentiate K562 erythroid differentiation induced by cytosine arabinoside, retinoic acid and mithramycin. Inducers of erythroid differentiation stimulating fetal gamma-globin synthesis could be considered for possible use in the experimental therapy of hematological diseases associated with a failure in the expression of adult beta-globin genes.

The DNA-binding drugs mithramycin and chromomycin are powerful inducers of erythroid differentiation of human K562 cells.

The human leukaemic K562 cell line can be induced in vitro to undergo erythroid differentiation by a variety of chemical compounds, including haemin, butyric acid, 5-azacytidine and cytosine arabinoside. Differentiation of K562 cells is associated with an increased expression of embryo-fetal globin genes, such as the zeta, epsilon and gamma globin genes. Therefore the K562 cell line has been proposed as a useful in vitro model system to determine the therapeutic potential of new differentiating compounds as well as to study the molecular mechanism(s) regulating changes in the expression of embryonic and fetal human globin genes. Inducers of erythroid differentiation which stimulate gamma-globin synthesis could be considered for possible use in the experimental therapy of those haematological diseases associated with a failure in the expression of adult beta-globin genes. In this paper we demonstrated that the G + C selective DNA-binding drugs chromomycin and mithramycin were powerful inducers of erythroid differentiation of K562 cells. Erythroid differentiation was associated with an increase in the accumulation of (a) Hb Gower 1 and Hb Portland and (b) gamma-globin mRNA.

Human leukemic K562 cells treated with cytosine arabinoside: enhancement of erythroid differentiation by retinoic acid and retinol.

Human leukemia K562 cells can be induced to erythroid differentiation when treated with a variety of compounds, including hemin, cytosine arabinoside and 5-azacytidine. Following erythroid induction, K562 cells express at high level gamma-globin and accumulate both Hb Portland and Hb Gower 1. In this paper we determined whether a combination treatment of K562 cells with suboptimal concentrations of cytosine arabinoside and retinoids lead to full expression of differentiated functions. Cell growth kinetics studies, intracellular detection of hemoglobin by benzidine staining and hemoglobin analysis by cellulose acetate were performed. The results obtained show that (a) retinoic acid and retinol are not able to induce differentiation of K562 cells and (b) cytosine arabinoside induces differentiation only when used at 100-300 nmol/l concentrations. In addition, our data demonstrate that erythroid differentiation of K562 occurs when 40 micromol/l of retinoic acid or retinol are added together with 75 nmol/l cytosine arabinoside.

Human leukemia K562 cells: induction to erythroid differentiation by guanine, guanosine and guanine nucleotides.

BACKGROUND AND OBJECTIVE: Human leukemic K562 cells are able to undergo erythroid differentiation in vitro when cultured with a variety of inducers, leading to increased expression of embryo-fetal globin genes such as the zita, epsilon and gamma-globin genes. Therefore the K562 cell line has been proposed as a very useful in vitro model system for determining the therapeutical potential of new differentiating compounds as well as for studying the molecular mechanism(s) that regulate changes in the expression of embryonic and fetal human globin genes. In this study we explored whether nucleoside triphosphates and related compounds are able to induce differentiation of K562 cells. METHODS: K562 cell differentiation was studied using the benzidine test; hemoglobins were characterized by cellulose acetate gel electrophoresis and mRNA accumulation was investigated by Northern blot analysis. RESULTS: The main conclusion of this paper is that guanine, guanosine and guanine ribonucleotides are effective inducers of K562 cell differentiation. Expression of both Hb Portland and Hb Gower 1 is increased in GTP-induced K562 cells. This increase is associated with greater gamma-globin mRNA accumulation. By contrast, ATP, CTP and UTP are not able to induce erythroid differentiation. INTERPRETATION AND CONCLUSIONS: These findings suggest that guanine, guanosine and guanine ribonucleotides are inducers of erythroid differentiation of K562 cells. This is of some relevance since differentiating compounds have been proposed as antitumor agents. In addition, inducers of erythroid differentiation that stimulate gamma-globin synthesis might be considered in the experimental therapy of hematological diseases associated with a failure in the expression of adult beta-globin genes.

[Surgical repair of laparocele with expanded PTFE: technicalities]. / Correzione chirurgica dei laparoceli con PTFEe: particolari di tecnica.

Surgical repair of ventral hernias may often be quite difficult; however, the use of prosthesis, now generally accepted by many surgeons, has improved the results of such type of surgery. The Authors experience confirm the safety of the expanded PTFE and its versatility of employment, obtaining good functional and aesthetic results.

Diacylglycerol kinase activity in rat liver nuclei.

Membrane-depleted rat liver nuclei contain diacylglycerol (DAG) kinase showing a specific activity which doubles that of the whole homogenate. In contrast, cytoplasmic and plasma membrane marker enzymes attain a specific activity of 0.4% at the most, when nuclear DAG kinase approaches 4.5% of the total tissue activity. The enzyme shows a Km of 161 and 200 microM for ATP in both nuclei and microsomes whereas the Km for DAG is 75 microM in nuclei and 658 microM in microsomes. Octylglucoside, CHAPS and Triton X-100 behave mainly as inhibitors, while deoxycholate stimulates the enzyme activity in both cellular fractions, increasing specific activity (3.2-fold in nuclei and 29.1-fold in microsomes) and decreasing Km for DAG (39 microM in nuclei and 237 microM in microsomes). Phospholipids and ceramide stimulate the enzyme activity in isolated nuclei, while no effect occurs in the microsomal fraction. At variance, sphingosine behaves as an inhibitor in both cellular fractions. DAG kinase also utilizes endogenous substrates mobilized by Bacillus cereus phospholipase C, which hydrolyses nuclear phosphatidylcholine and phosphatidylethanolamine and by phosphatidylinositol-specific phospholipase C, which hydrolyses nuclear PI and PIP. These data indicate that nuclear DAG can be controlled by converting it into phosphatidic acid by the action of a nuclear enzyme and support the contention that protein kinase C activity can be modulated at the nuclear level by a discrete system involving phospholipase C and DAG kinase that could operate independently from the cytoplasm.

In vitro specificity of EcoRI DNA methyltransferase.

The sequence selectivity of enzyme-DNA interactions was analyzed by comparing discrimination between synthetic oligonucleotides containing the canonical site GAATTC and altered DNA sequences with the EcoRI DNA methyltransferase. The specificities (kcat/KmDNA) are decreased from 5- to 23,000-fold relative to the unmodified site. For several substrates the decrease in kcat makes a disproportionate contribution to the specificity difference, suggesting that discrimination is mediated by the placement of critical catalytic residues rather than binding interactions. This is supported by our observation that specificity changes are generally not followed by changes in the stability of the methyltransferase-DNA complexes. Also, base pair substitutions near the site of methylation result in greater decreases in complex stability, suggesting that recognition and catalytic mechanisms overlap.