Cyclometalated Pt(ii) complexes with a bidentate Schiff-base ligand displaying unexpected cis/trans isomerism: synthesis, structures and electronic properties

Unexpected cis/trans isomerism in a bis-cyclometalated Pt(ii) complex is investigated by NMR, X-ray diffraction, optical, electrochemical and computational methods and rationalized.

Improvement of DNA recognition through molecular imprinting: hybrid oligomer imprinted polymeric nanoparticles (oligoMIP NPs)

Here we describe the production and characterization of oligoMIP NPs in which we have preorganized the oligonucleotide binding by molecular imprinting technology.

Contact X-ray microscopy of living cells by using LiF crystal as imaging detector

In this paper, the use of lithium fluoride (LiF) as imaging radiation detector to analyse living cells by single-shot soft X-ray contact microscopy is presented. High resolved X-ray images on LiF of cyanobacterium Leptolyngbya VRUC135, two unicellular microalgae of the genus Chlamydomonas and mouse macrophage cells (line RAW 264.7) have been obtained utilizing X-ray radiation in the water window energy range from a laser plasma source. The used method is based on loading of the samples, the cell suspension, in a special holder where they are in close contact with a LiF crystal solid-state X-ray imaging detector. After exposure and sample removal, the images stored in LiF by the soft X-ray contact microscopy technique are read by an optical microscope in fluorescence mode. The clear image of the mucilaginous sheath the structure of the filamentous Leptolyngbya and the visible nucleolus in the macrophage cells image, are noteworthiness results. The peculiarities of the used X-ray radiation and of the LiF imaging detector allow obtaining images in absorption contrast revealing the internal structures of the investigated samples at high spatial resolution. Moreover, the wide dynamic range of the LiF imaging detector contributes to obtain high-quality images. In particular, we demonstrate that this peculiar characteristic of LiF detector allows enhancing the contrast and reveal details even when they were obscured by a nonuniform stray light.

Flake size-dependent cyto and genotoxic evaluation of graphene oxide on in vitro A549, CaCo2 and vero cell lines

This study was carried out by varying both graphene oxide (GO) concentration (10 μg/mL, 50 μg/mL, 100 μg/mL) and flakes sizes of 1320 nm and 130 nm. Characterization by scanning electron microscopy and Raman spectroscopy demonstrate that the area of GO flakes varies of one order of magnitude but their chemical structure remains unmodified. A 24-h cytotoxicity test showed, for A549, a loss in the viability, while the test exhibits overall a positive increase in the viability for CaCo2 and Vero. A 24-h comet assay shows a marked GO genotoxicity: for micrometer-sized GO flakes the genotoxicity is in positive correlation with the concentration, while for nanometer-sized GO flakes there was a high degree of genotoxicity at the lowest concentration tested.

Besides the HLA loci: SNPs and non-HLA gene products as immunoregulatory factors in the onset of psoriatic arthritis subtypes

Psoriatic arthritis (PsA) is described as a multifactorial autoimmune rheumatic disease although its development is surely linked to some specific HLA genes (especially the HLA-Cw*06:02 allele). To date, its complex immunopathogenetic mechanism is not well clarified. Actually, increasing evidence suggest that qualitative and quantitative interplays between some PsA-susceptibility HLA alleles and other genetic, regulatory and environmental factors, may develop distinct subphenotypes of PsA. We first provide a brief summary of current knowledge about the various PsA conditions. Then, we consider the reasons why further analysis of the clinical course of patients affected by distinct PsA subsets, and who receive different therapeutic treatments, should be carried out in conjunction with deeper investigations about the identification of key genes and immunoregulatory agents by applying the most recent advances in biotechnology. This approach could better explain the molecular mechanisms responsible for both the onset and progression of this multi-faceted pathology with the purpose of significantly improving the management of PsA patients.

Immunogenetics and Hplc Analyses Contribute to Understanding the Etiopathology of Rheumatoid Arthritis through Studies on Ancient Human Remains

Genetic investigations on ancient human remains affected by rheumatological pathologies are a research field of particular interest for identifying origins and the etiopathology of diseases, especially those having an autoimmune background such as rheumatoid arthritis (RA). We wish to demonstrate how reliable studies concerning this topic require collaboration between multiple disciplines, usually starting from paleopathologic observations up to immunogenetic screening, even involving analytical chemistry. Here, we focused our investigation on the skeleton of Cardinal Carlo de'Medici (1595–1666) for whom RA and psoriatic arthritis (PsA) were postulated after paleopathologic examination. RA susceptibility is linked to specific HLA alleles belonging to DRB1*04 locus, such as DRB1*0401, while Cw*0602 and DRB1*07 predispose to PsA. Thus, we genotyped the Cardinal's remains to search for RA or PsA “risk genes”. Ancient DNA is often subjected to hydrolysis followed by fragmentation. For this reason, all immunogenetic tests were preceded by an original RP-HPLC-FL method able to inform on the ancient DNA preservation and the extent of contamination, with the purpose of avoiding the risk of false positive results. After DNA isolation from a piece of bone from the Cardinal, PCR-SSP and reverse-SSO hybridization assays were applied to perform genomic HLA-typing. RP-HPLC-FL analysis revealed a good preservation of DNA without contamination by exogenous genomes. Molecular tests assigned to the Cardinal the genotype DRB1*0401/*1102 for HLA-DRB locus and Cw*04/*12 for HLA-C locus, data that support a genetic predisposition for RA but not for PsA. This multidisciplinary study has allowed us: (i) to ascertain that the remains undoubtledy belonged to the specific subject, Cardinal Carlo de'Medici; (ii) to sustain that the subject suffered from RA rather then that PsA, and (iii) to state that RA was already widespread in Europe at the Renaissance age, despite some authors claiming that the disease was introduced to the Old Continent from America after colonization during the 18th century

[Update on the laparoscopic adrenal surgery in the second decade of the century: "doubts no more?]

Laparoscopic adrenal surgery has significantly improved during the last years. Thus at the moment it is possible to define such technique as the therapeutic "Gold Standard" option in the treatment of the adrenal tumors. However, some doubts are still remaining concerning the feasibility of laparoscopic adrenalectomy in case of malignant adrenal tumors, hyper-vascular tumors (pheochromocytoma) and indeterminate incidentaloma. This study aimed to review all the literature of the last three years (only article with abstracts) using the criteria of selection of the Cochrane Library, in order to find class I and class II-III studies which are able to surely or, respectively, probably respond to the various questions yet to be answered Two hundred and twelve papers have been selected. The class I studies stated the following evidences: laparoscopic treatment of pheochromocytoma is the Gold Standard too, independently from the dimension; the short term results of laparoscopic anterior and posterior approach are equivalent to those of the lateral one. Doubts still remain concerning the role of laparoscopy in the treatment of metastases, big pheochromocytomas, small size incidentalomas (risk of over-treatement). Nearly no respond has been given to others issues such as "the single port techniques" in laparoscopic adrenalectomy, the role of radiofrequency laparoscopic ablation of the adrenal tumor, the kind of treatment of stadium I and II adrenocortical carcinoma and big size (> 8 cm) tumors, the management of non-functioning incidentaloma of 4-6 cm, the role of the robot, and, finally, the approach of the bilateral tumors. We conclude that, despite many issues on the feasibility and safety of laparoscopy in the adrenal surgery have been definitely clarified, so that such technique has been declared the "Gold Standard" method in the treatment of the adrenal tumor, doubts still remain in some aspects of this method. However, since the researches in this field are proceeding with high evolution velocity, in the next future most of the questions that are still present should be definitively adressed.

Saponaria officinalis karyology and karyotype by means of image analyzer and atomic force microscopy

The aim of this work was to offer a contribution to the characterization of taxonomic entity of Saponaria officinalis (2n = 28; an herbaceous perennial species; saporin, a type 1 Ribosome Inactivating Protein, is present in leaves and seeds) by a cytogenetic and karyomorphological approach. We investigated the karyotype's morphometry correlated with Stebbin's symmetric index; the same information has been used for computing the indices resemblance between chromosomes (REC), symmetric indices (SYI), and total form (TF%) which allow the comparison between species and evaluation of karyological evolution. Fluorescence intensities of the stained nuclei were measured by a flow cytometer and, for the first time, values for nuclear DNA content were estimated by comparing nuclei fluorescence intensities of the test population with those of appropriate internal DNA standards. Our study is also aimed to introduce chromosomal volumes, which were determined by atomic force microscopy (AFM), as novel karyomorphological parameter which could allow for chromosome discrimination especially when tiny ones are present.

Mapping the intake of different elements in vegetal tissues by dual-energy X-ray imaging at DaPhine synchrotron light source

This article reports on the first utilization of the soft X-ray beamline at the DaPhine synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual-energy X-ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory-controlled samples of vegetal species. The results obtained by the nondestructive X-ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X-ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis.

Monitoring of the heavy-metal hyperaccumulation in vegetal tissues by X-ray radiography and by femto-second laser induced breakdown spectroscopy

This article reports on the utilization of X-ray microradiography and laser induced breakdown spectroscopy (LIBS) techniques for investigation of the metal accumulation in different part of leaf samples. The potential of the LIBS-analysis for finding the proper plant species for phytoremediation is compared with the results of microradiography measurements at the HERCULES source at ENEA, Rome (Italy) and X-ray microradiography experiments at the ELETTRA Synchrotron, Trieste (Italy).

Interactions between saporin, a ribosome-inactivating protein, and DNA: a study by atomic force microscopy

Saporins are enzymes belonging to the PNAG class (polynucleotide: adenosine glycosidase), plant enzymes commonly known as ribosome-inactivating proteins (RIP), as a result of their property of irreversibly damaging eukaryotic ribosomes. Direct imaging with tapping-mode atomic force microscopy (AFM) has been used to study pGEM-4Z plasmid DNA binding to the saporin-SO6 (isoform from Saponaria officinalis seeds). Saporin wrapped the plasmidic DNA, and distribution of the enzyme molecules along the DNA chain was markedly variable; plasmid digested with saporin-SO6 appeared fragmented or topologically modified. The supercoiled DNA strands were cleaved, giving rise to a linearized form and to relaxed forms. Electrophoretic analysis of the effect of standard preparations of saporin-SO6 on pGEM-4S confirmed the presence of DNA strand-cleaving activity.

Raltitrexed plus oxaliplatin as first-line chemotherapy in metastatic colorectal carcinoma: a multicentric phase II trial

For advanced colorectal carcinoma, two new drugs, raltitrexed (TOM) and oxaliplatin (L-OHP), have recently shown interesting results. Preclinical and clinical studies suggest that this combination, because of its favorable toxicity profile, high response rate and convenient schedule of administration, can be administered successfully in this disease. In our phase II study, 37 non pre-treated patients with metastatic colorectal carcinoma were treated with TOM (3 mg/m(2)) and L-OHP (130 mg/m(2)) every 3 weeks. In total, 222 cycles were administered; all patients received at least 2 cycles (median 6, range 2-8). There were two complete and 14 partial responses for an overall response rate of 43% (95% CI 27-69%). The median time to response was 2.5 months (range 2-4) and the median duration was 10.3 months (range 5-18). Twelve of the 23 (52%) patients with symptomatic colorectal cancer were classified as clinical benefit responders for at least 4 weeks during the study period. Treatment was well tolerated, and both acute, essentially hematologic, and cumulative hepatic and neurologic toxicities were manageable and reversible. Response rate and toxic effects observed during this study warrant additional studies comparing this TOM-L-OHP regimen with CPT-11 and/or capacitebine-containing regimens in metastatic colorectal carcinoma.

Stimulating effect of HIV-1 coat protein gp120 on corticotropin-releasing hormone and arginine vasopressin in the rat hypothalamus: involvement of nitric oxide

Subjects with human immunodeficiency virus type 1 (HIV-1) infection display increased activity of the hypothalamo-pituitary-adrenal (HPA) axis, which may play a role in both HIV-related neurodegenerative processes and disease progression. It has been speculated that the HIV coat protein gp120 may be responsible for these changes, and previous experimental evidence in both transgenic and nontransgenic mice supports this view. We speculated that one of the effects of gp120 in the CNS is to act within the hypothalamus to affect both corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP), the principal regulators of HPA axis. We therefore administered i.p. gp120 (100 ng/rat) or vehicle to male Wistar rats and then detected Fos protein (an index of neuronal activation), CRH, and AVP immunoreactivity in the cellular compartments of the hypothalamic paraventricular nucleus (PVN). In addition, we tested the direct effect of various concentrations of gp120 on the release of CRH and AVP from rat hypothalamic explants maintained in vitro. Any modulation of gp120 effects by nitric oxide (NO) pathways was also sought by coadministering i.p. to rats or adding to the hypothalamic preparations the NO synthase inhibitor N(G)-methyl-l-arginine (l-NMMA). Gp120 induced the expression of Fos protein in both the parvo- and the magnocellular PVN, which was significantly attenuated by l-NMMA 10(-6) nM/L (P < 0.001 vs gp120 alone). Double immunochemistry showed costaining for Fos protein and CRH or AVP in the PVN following gp120; the number of double-labeled CRH and AVP cells for Fos protein was markedly reduced (P < 0.001) by coadministration of l-NMMA 10(-6) nM/L. In the in vitro studies, addition of gp120 to the hypothalamic explants in the dose range of 10 pM-1 nM resulted in a clear stimulation of both CRH and AVP release (P < 0.05-0.001 compared to control); in the presence of l-NMMA at 10-fold higher concentrations the stimulatory effect of gp120 on the release of both peptides was completely lost. It would therefore appear that gp120 activates CRH and AVP-producing neurons in the hypothalamic PVN and stimulates the release of both peptides in vitro via NO-dependent mechanisms. These findings, in line with previous evidence, further suggest that the increased activity of the HPA axis associated with HIV infection may be of central origin, due to the effects of gp120 on hypothalamic CRH and AVP release.

[Gastrointestinal stromal tumors. A case of small intestine stromal tumor (SIST) with an uncertain biological aspect]

Tumors of the small intestine are relatively rare. The diagnosis is difficult to establish because the symptoms are vague and non-specific. Although the small intestine constitutes 75% of the length and over 90% of the mucosal surface area of the gastrointestinal tract, only 1 to 2% of gastrointestinal malignancies occur in this segment. Metastases are usually present at the time of diagnosis. The outcome of these patients can be improved if the possibility of a malignant small bowel tumor is considered in all cases of unexplained abdominal pain or gastrointestinal bleeding, especially in younger age. Malignant tumors occur with increasing frequency in distal small bowel with a preponderance of malignant lesions in the ileum compared with the jejunum and the duodenum. Adenocarcinoma is the most common tumor of the primary malignant small bowel tumors, followed by carcinoid, lymphoma and leiomyosarcoma. Mesenchymal tumors of the gastrointestinal tract, traditionally regarded as smooth muscle tumors, have demonstrated different cellular differentiations based on immunohistochemical and ultrastructural features. Therefore the terms leiomyoma and leiomyosarcoma have been replaced by a more encompassing term, gastrointestinal stromal tumor (GIST). The majority of GISTs occurs in the stomach; stromal tumors involving the small intestine (SISTs) are far less common but seem to have greater malignant potential. The clinical a case of a small intestinal stromal tumor (SIST), localised in the jejunum and characterised by an uncertain histological aspect, is presented and a review of the literature is made.

Incisional hernia and fascial defect following laparoscopic surgery

Complications involving the abdominal wall, particularly incisional hernias, were not expected when laparoscopic procedures were first introduced. With the increasing number of laparoscopies in abdominal surgery, more incisional hernias are observed. The authors report 13 cases of umbilical incisional hernia, which occurred late after laparoscopic cholecystectomy, and one case of omental procidentia through a lateral port, which occurred early after laparoscopic hernia repair with the transabdominal preperitoneal technique. There are 4 men and 10 women (mean age, 59.8 years; range, 40-74 years). Between March 1991 and December 1997, a total of 1,287 patients underwent laparoscopic operations at the Surgical Department of the Gradenigo Hospital in Turin, Italy. Incisional hernia incidence is 1%. Risk factors, such as chronic bronchitis or weight increase, which give rise to endoabdominal pressure, are present in some cases. Malnutrition may have a major role in many cases. Calculi larger than 15 mm are also seen frequently. Postlaparoscopy incisional hernia is generally a minor complication--only once did its occurrence cause a strangulated hernia. All precautions, including fascial suturing, must be taken to reduce the 1% incidence of postoperative incisional hernias.

Inhibition of L-tyrosine-induced micronuclei production by phenylthiourea in human melanoma cells

It was previously found that L-tyrosine oxidation product(s) are cytotoxic, genotoxic and increase the sister chromatid exchange (SCE) levels in human melanoma cells. In this work, the micronucleus assay has been performed on human melanotic and amelanotic melanoma cell lines (Carl-1 MEL and AMEL) in the presence of 1.0, 0.5 and 0.1 mM L-tyrosine concentrations to investigate if melanin synthesis intermediate(s) increase micronuclei production. L-Tyrosine oxidation product(s) increased the frequency of micronuclei in melanoma cells; 0.1 mM phenylthiourea (PTU), an inhibitor of L-tyrosine oxidation by tyrosinase, lowered the micronucleus production to the control levels. The culture of melanoma cells with high L-tyrosine in the culture medium resulted in a positive response to an ELISA-based apoptotic test. For comparison the effect of L-tyrosine on micronuclei production in human amelanotic melanoma cells was also investigated; the micronucleus production in the presence of 1 mM L-tyrosine in the culture medium was lower than that found with melanotic melanoma cells of the same cell line. The data suggest that melanin synthesis intermediates arising from L-tyrosine oxidation may cause micronuclei production in Carl-1 human melanoma cells; the addition of PTU in the presence of L-tyrosine decreased the frequency of micronuclei to about the control values thus the inhibition of melanogenesis may have some clinical implication in melanotic melanoma.

Effect of tyrosinase inhibitors on Tuber borchii mycelium growth in vitro

This paper reports the effect of the tyrosinase (monophenol o-diphenol:oxygen oxidoreductase; EC 1.14.18.1) inhibitors diethyldithiocarbamate (DETC), L-tropolone, kojic acid, phenylthiourea (PTU) and L-mimosine on the in vitro growth of Tuber borchii (a white truffle) mycelium. A significant inhibitory effect on mycelium growth was observed for DETC, PTU and L-tropolone (0% growth compared to control at 100 microg ml(-1) DETC, PTU and L-tropolone and at 10 microg ml(-1) DETC and L-tropolone). As a comparison the action of the same inhibitors was also tested on the growth and pigmentation of the mould Cladosporium sphaerospermum. In the presence of CuSO(4) 10(-6) M T. borchii mycelium acquired pigmentation (as rounded aggregates compared to control revealed by SEM microscopy). Tyrosinase activity in the extract from T. borchii mycelium (18-day culture) was detected spectrophotometrically.

Antiproliferative effect and apoptotic response in vitro of human melanoma cells to liposomes containing the ribosome-inactivating protein luffin

The present study describes the liposome-mediated delivery of the type 1 ribosome-inactivating protein luffin to human melanoma cells in vitro. Luffin from Luffa cylindrica seeds has been successfully incorporated into lecithin/cholesterol and lecithin/cholesterol/dicetylphosphate negatively charged liposomes. The exposure of melanoma cells to the two types of liposomes resulted in the inhibition of protein synthesis and cell growth; apoptotic cell death was verified by means of TUNEL reaction and quantitation of cytosolic oligonucleosome-bound DNA. The toxicity of encapsulated luffin varied with the lipid composition of the vesicles; the strongest effect was observed with lecithin/cholesterol liposomes. These results identify liposome-incorporated luffin as a possible alternative to immunotoxins for the treatment of human melanoma in situ.

Kininergic system and arterial hypertension following chronic exposure to inorganic lead

Rats were exposed for 10 months to 60 ppm of Pb (as acetate) in drinking water. Systolic and diastolic blood pressure and cardiac inotropism were increased by the metal, which reduced arterial blood flow and unaffected heart rate. The activities of plasma angiotensin I-converting enzyme (ACE) and kininase II were strongly augmented by Pb, suggesting markedly increased and decreased levels of plasma angiotensin II and bradykinin, respectively. Moreover, the Pb-exposed rats showed a lower increase of the plasma kallikrein and kininase I activities. These results are discussed in the context of the complex relationships linking the renin-angiotensin-aldosterone (RAA), kallikrein-kinin and other autacoidal, neurohumoral (e.g., catecholaminergic) and transductional systems (e.g., nitric oxide (NO)). Pb was confirmed to induce arterial hypertension and cardiovascular alterations at plasma levels similar to those observed in the general population or in subjects with short occupational exposure.

Incisional hernia and fascial defect following laparoscopic surgery

Complications involving the abdominal wall, particularly incisional hernias, were not expected when laparoscopic procedures were first introduced. With the increasing number of laparoscopies in abdominal surgery, more incisional hernias are observed. The authors report 13 cases of umbilical incisional hernia, which occurred late after laparoscopic cholecystectomy, and one case of omental procidentia through a lateral port, which occurred early after laparoscopic hernia repair with the transabdominal preperitoneal technique. There are 4 men and 10 women (mean age, 59.8 years; range, 40-74 years). Between March 1991 and December 1997, a total of 1,287 patients underwent laparoscopic operations at the Surgical Department of the Gradenigo Hospital in Turin, Italy. Incisional hernia incidence is 1%. Risk factors, such as chronic bronchitis or weight increase, which give rise to endoabdominal pressure, are present in some cases. Malnutrition may have a major role in many cases. Calculi larger than 15 mm are also seen frequently. Postlaparoscopy incisional hernia is generally a minor complication--only once did its occurrence cause a strangulated hernia. All precautions, including fascial suturing, must be taken to reduce the 1% incidence of postoperative incisional hernias.

The plant ribosome inactivating protein saporin induces micronucleus formation in peripheral human lymphocytes in vitro

Saporin belongs to the family of plant enzymes known as ribosome inactivating proteins (RIPs) for their property to depurinate the major rRNA, thus leading to inactivation of ribosomes. In this work we analyzed the genotoxic effects of saporin, purified from root cultures of Saponaria officinalis, by evaluating micronucleus formation and by the quantitative determination of cytosolic histone-associated DNA fragments. Saporin induces micronuclei formation in cultured human lymphocytes in a dose dependent manner; treated lymphocytes show a decrease in cell viability and a concomitant increase in the apoptotic response evidenced by the appearance of cytosolic oligonucleosomes. On the other hand saporin treatment failed to induce sister-chromatid exchange (SCE) at any of the doses tested.

Differential response of human melanoma and Ehrlich ascites cells in vitro to the ribosome-inactivating protein luffin

The cytotoxicity and inhibitory effect on proliferation of the type 1 ribosome-inactivating protein luffin purified from the seeds of Luffa aegyptiaca were investigated both in human metastatic melanoma cells and in murine Ehrlich ascites tumour cells. Results indicate that luffin from the seeds of Luffa aegyptiaca is cytotoxic to the cell lines tested, with approximately 10 times greater potency in Ehrlich cells. Luffin was found to induce an increase in cytosolic oligonucleosome-bound DNA in both melanoma and Ehrlich ascites tumour cells, the level of DNA fragmentation in the former cell line being higher than in the latter. Experiments with melanoma cells indicate that an increase in cytosolic nucleosomes could be supportive of apoptosis as the type of cell death induced by luffin.

Adaptive response of human melanoma cells to methylglyoxal injury

The effects of methylglyoxal on the growth of a line of human melanoma cells are investigated. Methylglyoxal inhibits cell growth in a dose-dependent manner and causes an increase in glyceraldehyde 3-phosphate dehydrogenase, and glyoxalase 1 and glyoxalase 2 specific activities. The cellular response to increasing concentrations of methylglyoxal in the culture medium is also studied by measuring L-lactate production, reduced-oxidized glutathione levels and apoptotic cell death. Methylglyoxal seems to promote a change of cell population phenotypic repertoire toward a more monomorphic phenotype. In conclusion, methylglyoxal seems to induce an enzymatic cellular response that lowers methylglyoxal levels and selects the most resistant cells.

Saporin production from in vitro cultures of the soapwort Saponaria officinalis L

We report here the successful establishment of callus, cell and root cultures from explants of in-vitro-grown plantlets of the soapwort Saponaria officinalis L. The production of saporin in the different tissue systems was evaluated by determining the capability of crude extracts to inactivate protein synthesis and by Western blotting analysis. Protein synthesis inhibition varied in callus and derived cell suspensions and in cultured roots, the latter, in particular, showing the lowest specific activity. The ribosome-inactivating principle from root cultures was purified to homogeneity by cation exchange chromatography.

RolB expression pattern in the early stages of carrot somatic embryogenesis

The pattern of expression of the rolB gene, derived from the T-DNA of the plant pathogen Agrobacterium rhizogenes, has been investigated during the early stages of somatic embryo formation in suspension cultures of carrot (Daucus carota L.). The reporter gene GUS (Escherichia coli beta-glucuronidase), under transcriptional control of full-length rolB promoter region, has been utilized in order to evaluate both qualitative and quantitative variations in the expression pattern. Fluorimetric measurements point to the developmental regulation of the gene, while results from histochemical analysis indicate that the promoter of rolB is firstly activated in the central (core) region of the globular embryos.

Sister chromatid exchange (SCE) rates in human melanoma cells as an index of mutagenesis

Melanomas are highly clonogenic. Genetic variability and polymorphism of tumour cell populations have been reported. However, no direct evidence of mutator activity as a source of genetic polymorphism for melanoma cells has been described. Some intermediates of melanin synthesis are cytotoxic and genotoxic and their mutagenic power has been described. We show here that the rate of sister chromatid exchange (SCE) of the line of human melanoma cells used varies with the concentration of the melanin precursor L-tyrosine, in the culture medium. An increase of melanin synthesis results in increased SCE rates. The highest values of SCEs are found in melanotic melanoma cells compared with the amelanotic ones. Indeed we present evidence that melanoma cells show higher levels of SCE when compared with normal human lymphocytes, and to the SCE frequencies derived from the literature on the lymphocytes of familial malignant melanoma, sporadic malignant melanoma patients and the lymphocytes of relatives of familial and sporadic melanoma patients.

[Indications for hepatic resection: personal experience]

The Authors, before examining their case history, which includes 103 major and minor hepatic resections performed during the last decade, briefly show the surgical technique concerning hepatic ischaemia and the new technologies proposed to reduce the hematic loss during hepatic resections. The constant adoption of these techniques and the careful evaluation of some parameters concerning hepatic functionality allowed to decrease postoperative complications and mortality, which currently is around 5-10%. These data are confirmed by the Authors experience.

Stimulation of corticotrophin-releasing hormone release by the obese (ob) gene product, leptin, from hypothalamic explants

Recent data have suggested that adipocytes synthesize and secrete a 16 kDa peptide which acts centrally to regulate weight gain by suppressing appetite and activating the sympathetic nervous system. To exert such effects, it may function as an endogenous ligand in the CNS, since specific receptors (OB-R) have been recently reported to be widely distributed in the brain. We have speculated that this peptide, now known as leptin, may act centrally by stimulating the release of corticotrophin-releasing hormone (CRH), a recognized potent inhibitory modulator of appetite. We tested in vitro the effect of murine leptin on CRH secretion in the dose range of 0.1 pM-100 nM. The static rat hypothalamic incubation system used involved fresh hypothalamic explants maintained in EBSS with consecutive 20 min incubations, and estimation of CRH concentrations in the medium by a specific and sensitive radioimmunoassay. The effect of heat-denatured leptin at a dose of 1 nM and 10 nM, was also investigated. Any possible modulation of leptin effects by adrenergic pathways was then explored by coincubating hypothalami with leptin 10 nM and equimolar concentrations of the alpha 1-adrenergic antagonist prazosin or the beta-adrenergic antagonist propranolol. The active leptin, but not the heat-inactivated peptide, caused a dose-dependent stimulation of CRH release in vitro (p < 0.05- < 0.0001 vs control), with a plateau effect at a dose of 10 nM. The addition of either prazosin or propranolol was without effect on leptin-dependent CRH stimulation. These findings are consistent with the reported presence of leptin receptors in the rat brain, and suggest that leptin may act to regulate appetite at least in part by directly modulating the secretion of CRH from the hypothalamus. It would also appear that such effect occurs via a non-adrenergic mechanism.

Molecular approach to the nucleo-melanosomal interaction in human melanoma cells

This paper presents evidence that L-tyrosine oxidation products and 5,6-dihydroxyindole, an intermediate of melanin synthesis bind to and modify DNA structure, as tested by extracting cell DNA, using topoisomerase I and denaturation assays. When supercoiled plasmid pCU18 or pBR322 DNAs are treated with 5,6-dihydroxyindole the supercoiled species disappear and are converted to species less mobile in a gel retardation test with respect to relaxed DNA, 5,6-Dihydroxyindole causes an easier acid denaturation of the double helix. The results, that are dose dependent, would point to both intercalation and cross-linking of DNA by 5,6-dihydroxyindole and its oxidation product(s). 3H-L-tyrosine deriving radioactivity, bound to nuclear DNA, is higher at low pH, (5.6) if compared to pH 6.8. The highest radioactivity bound to cell DNA is found during the transition from the amelanotic to the melanotic phenotype in human melanoma cell lines. As a control, the binding of 3H-L-tyrosine radioactivity to human prostate fibroblast DNA was investigated.

Cyto-genotoxic species leakage within human melanoma melanosomes. Molecular-morphological correlations

This work studies the phenotype changes, relating to pigment expression, of a human melanoma cell line. The phenotypic instabilities and proliferation rates are correlated with the production and release in the cell culture medium of active oxygen species and melanin synthesis intermediates. The proliferation rates versus L-tyrosine concentration in the culture media are investigated: a decrease is found when high L-tyrosine is added to the medium. This would be consistent with the release of cytotoxic and/or genotoxic species by melanoma cells. The morphology of melanoma melanosomes is coherent with the leakage of cytotoxic and genotoxic species produced during melanin synthesis.

Specific increase of L-dopa levels in plasma upon infusion of tyrosinase containing liposomes

1. The present paper reports the effects of liposome-entrapped tyrosinase (EC 1.14.18.1. L-Tyrosine, L-3,4-dihydroxyphenylalanine: oxygen oxidoreductase) infusion on the catecholamine contents of rat plasma. The actions of liposomes and free tyrosinase have also been investigated. 2. From the experiments, evidence has been obtained that liposome-entrapped tyrosinase is able to affect specifically L-3,4-dihydroxyphenylalanine (L-DOPA) levels which increase dramatically. 3. The possible use of liposome-entrapped tyrosinase to raise L-DOPA levels in catecholamine related disorders is discussed. 4. Liposomes without tyrosinase provoke no significant changes of catecholamine or L-DOPA levels while free tyrosinase does induce a change but in a less constant fashion than the liposome-entrapped enzyme.

Developmental aspects of Bufo bufo embryo glutathione transferases

The expression of glutathione transferase isoenzymes has been studied during the development of Bufo bufo embryo. By analysing the GSH-affinity purified materials in terms of substrate specificities, SDS-PAGE pattern, HPLC elution profile, we conclude that, up to stage 22, no significant changes in the expression of glutathione transferases isoenzymes occurred during Bufo bufo embryo development. At stage 25 the distribution of glutathione transferases was found to be slightly different from those of all other foregoing stages. A marked decrease of embryonic glutathione transferases subunits with a parallel appearance of new structurally and immunologically different subunits was noted in toad liver and kidney. Toad ovary continued to express embryonic glutathione transferase subunits.

Glutathione transferase isoenzymes from Bufo bufo embryos at an early developmental stage

Six forms of glutathione transferase (GST) were resolved from the cytosolic fraction of Bufo bufo embryos at developmental stage 4 by GSH-Sepharose affinity chromatography followed by f.p.l.c. chromatofocusing in the 9-6 pH range. They have apparent isoelectric points at pH 8.37 (GST I), 8.22 (GST II), 8.10 (GST III), 7.84 (GST IV), 7.37 (GST V) and 7.12 (GST VI), and each displayed an apparent subunit molecular mass of 23 kDa by SDS/PAGE. The Bufo bufo embryo enzymes showed very similar structural, catalytic and immunological properties, as indicated by their substrate-specificities, inhibition characteristics, c.d. spectra, h.p.l.c. elution profiles and immunological reactivities, as well as by their N-terminal amino acid sequences. Although Bufo bufo embryo GSTs do not correspond to any other known GSTs, the results of our experiments indicate that amphibian GSTs could be included in the Pi family of GSTs. This conclusion is supported by the analysis of c.d. spectra, and by the fact that mammalian Pi class GSTs and amphibian GSTs showed about 80% identity in their N-terminal amino acid sequences. Furthermore, antisera prepared against Bufo bufo GST III cross-reacted in immunoblotting analysis with Pi class GSTs, and vice versa.

Changes of lipo-melanosome membrane leakage versus pH, charge and composition

Liposome models of melanosomes (lipo-melanosomes) were used to investigate how phospholipid composition, charge and medium pH may affect the lipo-melanosome membrane permeability to active oxygen species or melanin synthesis intermediaries. Active oxygen accumulated only at pH 6.4 and was polarographically monitored using superoxide dismutase and/or catalase. Cholesterol appears to increase the O2- accumulation at pH 6.4 while incorporation of positive phospholipids within lipo-melanosomes results in the loss of latency with respect to tyrosinase substrate and intermediates of melanin synthesis.

Mutagenicity test for unstable compounds, such as 5,6-dihydroxyindole, using an Escherichia coli HB101/pBR322 transfection system

A mutagenicity test for unstable chemical compounds has been devised. The test makes use of (i) in vitro treatment of plasmid pBR322 with the putative mutagen (ii) subsequent transfection of Escherichia coli HB101; (iii) selection either on tetracycline- or ampicillin-containing Eugon agar (iv) cross-antibiotic replica plating and recovery of single antibiotic resistant colonies (v) restriction analysis of pBR322 isolated from single antibiotic resistant colonies. In this work the test has been used to assess the mutagenicity of 5,6-dihydroxyindole, a cytotoxic intermediate of melanin biosynthesis.

Liposome-entrapped tyrosinase: a tool to investigate the regulation of the Raper-Mason pathway

The effect of the entrapment of mushroom tyrosinase (EC 1.14.18.1) within liposomes on the enzyme activity and Km vs. L-3,4-dihydroxyphenylalanine is reported in the present work; the effect of cholesterol insertion within liposome membranes on the enzyme activity has also been studied. The oxidation rates of various monophenols and diphenols by free and liposome-integrated mushroom tyrosinase were measured and the oxidation latencies vs. different substrates investigated. The different substrates are apparently oxidized according to the properties of the substituents as electron donors or acceptors; the Km values vs. L-3,4-dihydroxyphenylalanine calculated on measuring O2 consumption are higher than those calculated on measuring the dopachrome production rates. It is interesting that natural substrates of tyrosinase are oxidized according to a negative catalysis by the liposome-entrapped enzyme; this point is discussed in relation to the well known cytotoxicity of some intermediates of the Raper-Mason pathway.

Effects of supidimide in schizophrenic inpatients undergoing neuroleptic maintenance therapy with haloperidol

Forty schizophrenic inpatients, on constant low-dosage maintenance therapy with haloperidol, entered a superimposed, double-blind, placebo-controlled clinical trial with supidimide 2 x 200 mg per day. The double-blind phase lasted 5 days and was preceded and followed by single-blind base line and washout periods, respectively, during which all patients received matching placebos. The therapeutic effects were evaluated by BPRS, NOSIE, a post-sleep questionnaire, and, in a subgroup of patients, by objective monitoring of movements during sleep. Supidimide substantially relieved sleep disturbances, as demonstrated by subjective (p less than 0.05; n = 20) and objective (p less than 0.1; n = 3) measurements. In addition, the following drug-related effects (p less than 0.05 versus base line and placebo) on daytime behaviour were observed: a decrease in "somatic concern" (BPRS), items related to agitation (BPRS), "irritability" and "manifest psychosis" (NOSIE), and a slight increase in "retardation" (NOSIE). No adverse effects attributable to supidimide were detected. It is concluded that supidimide exerts beneficial effects on day-time behaviour and sleep in agitated schizophrenic patients undergoing low-dosage maintenance neuroleptic therapy.