Unraveling the parahormetic mechanism underlying the health-protecting effects of grapeseed procyanidins

Proanthocyanidins (PACs), the predominant constituents within Grape Seed Extract (GSE), are intricate compounds composed of interconnected flavan-3-ol units. Renowned for their health-affirming properties, PACs offer a shield against a spectrum of inflammation associated diseases, such as diabetes, obesity, degenerations and possibly cancer. While monomeric and dimeric PACs undergo some absorption within the gastrointestinal tract, their larger oligomeric and polymeric counterparts are not bioavailable. However, higher molecular weight PACs engage with the colonic microbiota, fostering the production of bioavailable metabolites that undergo metabolic processes, culminating in the emergence of bioactive agents capable of modulating physiological processes. Within this investigation, a GSE enriched with polymeric PACs was employed to explore in detail their impact. Through comprehensive analysis, the present study unequivocally verified the gastrointestinal-mediated transformation of medium to high molecular weight polymeric PACs, thereby establishing the bioaccessibility of a principal catabolite termed 5-(3',4'-dihydroxyphenyl)-γ-valerolactone (VL). Notably, our findings, encompassing cell biology, chemistry and proteomics, converge to the proposal of the notion of the capacity of VL to activate, upon oxidation to the corresponding quinone, the nuclear factor E2-related factor 2 (Nrf2) pathway-an intricate process that incites cellular defenses and mitigates stress-induced responses, such as a challenge brought by TNFα. This mechanistic paradigm seamlessly aligns with the concept of para-hormesis, ultimately orchestrating the resilience to stress and the preservation of cellular redox equilibrium and homeostasis as benchmarks of health.

Salivary proteomic profile of young healthy subjects

Background: The incidence of noncommunicable diseases (NCDs) has been rapidly ramped up worldwide. Hence, there is an urgent need to non-invasively detect NCDs possibly by exploiting saliva as a 'liquid biopsy' to identify biomarkers of the health status. Since, the absence of standardized procedures of collection/analysis and the lack of normal ranges makes the use of saliva still tricky, our purpose was to outline a salivary proteomic profile which features healthy individuals. Methods: We collected saliva samples from 19 young blood donors as reference population and the proteomic profile was investigated through mass-spectrometry. Results: We identified 1,004 proteins of whose 243 proteins were shared by all subjects. By applying a data clustering approach, we found a set of six most representative proteins across all subjects including Coronin-1A, F-actin-capping protein subunit alpha, Immunoglobulin J chain, Prosaposin, 78 kDa glucose-regulated protein and Heat shock 70 kDa protein 1A and 1B. Conclusion: All of these proteins are involved in immune system activation, cellular stress responses, proliferation, and invasion thus suggesting their use as biomarkers in patients with NCDs.

Hemodialysis without Anticoagulants in Patients with High Bleeding Risk

Twenty hemodialysis were performed in six uremic patients with high bleeding risk, with a technique avoiding any anticoagulant drug before or during the treatment.

The treatment was well tolerated in all patients and no alterations were observed in the intrinsic clotting system evaluated before, during and after hemodialysis.

During the study, devices were never lost because of clotting or rupture, and their performances were similar to those obtained on heparin hemodialysis.

We suggest that in critically ill patients, needing dialysis, hemodialysis without heparin is possible and safe.

Branched Chain and Aromatic free Amino Acids in Plasma and Skeletal Muscle of uremic Patients Undergoing Hemodialysis and CAPD

Plasma and skeletal muscle free amino acids were measured in patients submitted to Hemodialysis (HD) or Continuous Ambulatory Peritoneal Dialysis (CAPD) in order to evaluate the effects of these different dialysis modalities on amino acid pools; the data were compared with those obtained in control subjects and in patients with advanced Chronic Renal Failure (CRF) not submitted to Regular Dialysis Treatment (RDT).

Our findings show low intracellular concentrations of VAL, total Branched Chain Amino Acid (BCAA) and TYR in uremic patients treated with CAPD but not in those undergoing HD.

The observed differences in muscle amino acid pattern could be well explained by a changed amino acid metabolism regulation in CAPD, possibly related to the sustained hyperinsulinism and to an increased rate of hepatic protein synthesis.

Standardisation of defined approaches for skin sensitisation testing to support regulatory use and international adoption: position of the International Cooperation on Alternative Test Methods

Skin sensitisation is the regulatory endpoint that has been at the centre of concerted efforts to replace animal testing in recent years, as demonstrated by the Organisation for Economic Co-operation and Development (OECD) adoption of five non-animal methods addressing mechanisms under the first three key events of the skin sensitisation adverse outcome pathway. Nevertheless, the currently adopted methods, when used in isolation, are not sufficient to fulfil regulatory requirements on the skin sensitisation potential and potency of chemicals comparable to that provided by the regulatory animal tests. For this reason, a number of defined approaches integrating data from these methods with other relevant information have been proposed and documented by the OECD. With the aim to further enhance regulatory consideration and adoption of defined approaches, the European Union Reference Laboratory for Alternatives to Animal testing in collaboration with the International Cooperation on Alternative Test Methods hosted, on 4-5 October 2016, a workshop on the international regulatory applicability and acceptance of alternative non-animal approaches, i.e., defined approaches, to skin sensitisation assessment of chemicals used in a variety of sectors. The workshop convened representatives from more than 20 regulatory authorities from the European Union, United States, Canada, Japan, South Korea, Brazil and China. There was a general consensus among the workshop participants that to maximise global regulatory acceptance of data generated with defined approaches, international harmonisation and standardisation are needed. Potential assessment criteria were defined for a systematic evaluation of existing defined approaches that would facilitate their translation into international standards, e.g., into a performance-based Test Guideline. Informed by the discussions at the workshop, the ICATM members propose practical ways to further promote the regulatory use and facilitate adoption of defined approaches for skin sensitisation assessments.

Autochthone Fälle von caniner Babesiose im Kanton Solothurn

Starting in November 2003 a series of five clinical cases of canine babesiosis was registered in the region of Obergösgen (canton Solothurn). All presented dogs showed increased body temperature, thrombocytopenia and hemoglobinuria, and none of the dogs had been abroad or visited endemic regions in the southern or western part of Switzerland so far. Babesia canis was detected in the blood smears of all five patients, but only three had detectable specific antibodies against this parasite. However, seroconversion was found in a second sample collected from the negative dogs at a later timepoint, confirming the diagnosis of canine babesiosis. The blood samples of two parasitized dogs were used for DNA-isolation and were tested with a Babesia-specific PCR, detecting the 18S rRNA-gene. Sequencing of the amplified products revealed a 100% identity with the sub-species B. canis canis. The ticks Rhipicephalus sanguineus and Dermacentor marginatus are potential vectors for B. canis. In the area where the infection with B. canis was suspected a total of 152 ticks was collected and characterized; one was a female R. sanguineus.Although babesia could not be detected in the latter tick and the final prooffor the complete life cycle is still lacking, it is very probable that B. canis has become autochthonous in the canton Solothurn.

An international trial of quantitative PCR for monitoring Legionella in artificial water systems

AIMS

  To perform an international trial to derive alert and action levels for the use of quantitative PCR (qPCR) in the monitoring of Legionella to determine the effectiveness of control measures against legionellae.

METHODS AND RESULTS

  Laboratories (7) participated from six countries. Legionellae were determined by culture and qPCR methods with comparable detection limits. Systems were monitored over ≥10 weeks. For cooling towers (232 samples), there was a significant difference between the log mean difference between qPCR (GU l(-1) ) and culture (CFU l(-1) ) for Legionella pneumophila (0·71) and for Legionella spp. (2·03). In hot and cold water (506 samples), the differences were less, 0·62 for Leg. pneumophila and 1·05 for Legionella spp. Results for individual systems depended on the nature of the system and its treatment. In cooling towers, Legionella spp. GU l(-1) always exceeded CFU l(-1) , and usually Legionella spp. were detected by qPCR when absent by culture. The pattern of results by qPCR for Leg. pneumophila followed the culture trend. In hot and cold water, culture and qPCR gave similar results, particularly for Leg. pneumophila. There were some marked exceptions with temperatures ≥50°C, or in the presence of supplementary biocides. Action and alert levels for qPCR were derived that gave results comparable to the application of the European Guidelines based on culture. Algorithms are proposed for the use of qPCR for routine monitoring.

CONCLUSIONS

  Action and alert levels for qPCR can be adjusted to ensure public health is protected with the benefit that remedial actions can be validated earlier with only a small increase in the frequency of action being required.

SIGNIFICANCE AND IMPACT OF THE STUDY

  This study confirms it is possible to derive guidelines on the use of qPCR for monitoring the control of legionellae with consequent improvement to response and public health protection.

An investigation on the Culicoides species composition at seven sites in southern Switzerland

In the past decade, there have been regular outbreaks of bluetongue (BT) in many parts of Europe. Owing to the presence of BT disease and its vectors in countries adjacent to Switzerland, an initial entomological survey was conducted in 2003, which established the presence of several midges of the genus Culicoides (Diptera: Ceratopogonidae). Subsequently, a sentinel herd monitoring system was established with the primary entomological aim being the determination and further study of Culicoides population compositions. Insects were collected in 2005 and 2006 at seven sentinel herd sites in the south of Switzerland (canton of Ticino) near the border of Italy, using Onderstepoort-type light traps. This region is botanically and zoologically similar to the Mediterranean and is one of the warmest and most humid areas of the country, hence it is considered a potential access path for BT disease into Switzerland. Collections were made at four cattle farms, two equestrian centres and one goat farm. Sites were sampled four times per month from June to October. Traps were operated from dusk until dawn and samples were collected monthly for analysis through microscopy as well as a Culicoides imicola-specific PCR. Results confirmed the absence of C. imicola (Kieffer) and demonstrated that the potential BT virus vectors are highly abundant, notably: Culicoides obsoletus (Meigen), Culicoides scoticus (Downes & Kettle) and Culicoides dewulfi (Goetghebuer) subgenus Avaritia and Culicoides pulicaris (Linnaeus) subgenus Culicoides. These findings expand the current knowledge of Culicoides population composition in the southern part of the Switzerland. Culicoides cataneii (Clastrier), Culicoides flavipulicaris (Dzhafarov), Culicoides indistinctus (Khalaf), Culicoides nubeculosus (Meigen) and species of the Grisescens complex were reported for the first time in Switzerland.

Is fasting glucose variability a risk factor for retinopathy in people with type 2 diabetes?

AIMS

Fasting plasma glucose variability strongly predicts the incidence of cardiovascular events in type 2 diabetic patients. We prospectively assessed whether fasting plasma glucose variability predicts the development/progression of retinopathy in a large cohort of type 2 diabetic outpatients.

METHODS

In the period 1996-1999, 1019 type 2 diabetic participants (aged 69+/-11 years) in the Verona Diabetes Study underwent at least 3 fasting plasma glucose (FPG) determinations and an eye examination by retinography. Of these, 746 underwent a 2nd eye examination in the period 2000-2004, while 273 did not (102 patients had died before undergoing the 2nd eye examination). For each patient, the mean (M-FPG) and the coefficient of variation of FPG (CV-FPG) were computed.

RESULTS

By the 2nd eye examination, 124 patients had either developed new retinopathy (79 patients) or progressed to a more severe degree of retinopathy (45 patients). In a multivariable logistic regression analysis, the development/progression of retinopathy was independently predicted by average glycaemia over time, expressed as glycated haemoglobin (odds ratio [OR] 1.82, 95%CI 1.40-2.38 for 1 SD increase) or M-FPG (OR 1.88, 1.47-2.41), but not by CV-FPG. Among other independent variables, HDL-cholesterol was inversely associated with the development/progression of retinopathy.

CONCLUSIONS

These results suggest that in elderly type 2 diabetic patients the magnitude of hyperglycaemia, but not fasting plasma glucose variability, strongly predicts the development/progression of diabetic retinopathy independently of other known risk factors.

Complete (1)H and (13)C NMR spectral assignment of alpha- and beta-adenosine, 2'-deoxyadenosine and their acetate derivatives

(1)H and (13)C NMR chemical shifts of alpha- and beta-anomers of adenosine, 2'-deoxyadenosine and their acetate derivatives were completely and definitely assigned using the concerted application of one- and two-dimensional experiments (gCOSY, gNOESY, gHSQC and gHMBC). The influence of the stereochemistry of the purine base on the NMR data of the hydrogen and carbon atoms of the furanose moiety was estimated.

Mitochondrial function, apoptosis and cell cycle delay in the WEHI-3B leukaemia cell line and its variant Ciprofloxacin-resistant WEHI-3B/CPX

OBJECTIVE

The susceptibility of two cell lines, WEHI-3B myelomonocytic leukaemia and its variant Ciprofloxacin-resistant WEHI-3B/CPX to undergo apoptosis induced by Ciprofloxacin was studied and compared.

MATERIALS AND METHODS

Apoptosis was checked by measuring the DNA fragmentation and determining the ratio of apoptotic/necrotic cells. The relationship between the induction of apoptosis and G(1), S or G(2) block in the cell cycle has also been investigated and cytogenetical evaluation of chromosomal aberrations in both cell lines has been carried out. The regulation of expression of Bax and Bcl-2 was also checked by western blotting after Ciprofloxacin treatment.

RESULTS

We observed that the resistance of the subline was caused by a small percentage of cells that underwent apoptosis during continuous exposure to Ciprofloxacin in comparison with the parental cell line, whereas the percentage of necrotic cells remained unchanged. The WEHI-3B cells showed a G(2) block and a higher degree of cytogenetic damage after drug exposure. The two cell lines expressed the same level of Bax and Bcl-2 following stimulation by Ciprofloxacin. Only in the resistant subclone, the ratio Bcl-2/Bax reversed in the anti-apoptotic gene expression.

CONCLUSION

The resistance to ciprofloxacin observed is not related to mitochondrial function and although Bcl-2/Bax ratio behaviour does not fully explain the resistance of the WEHI3B/CPX subclone it is consistent with phenotypic character of resistance to CPX. The toxic effect on sensitive cells could be mediated by the cell cycle arrest whereas in the resistant clone, the prolonged G(2) phase could play a key role to favour cell cycle progression and proliferation.

Stakeholder appraisal of policy options for responding to obesity in Italy

This article deals with the phenomenon of obesity in contemporary Italian society. It is based on the fieldwork carried out during the year 2005 within the European Union-funded project 'PorGrow: policy options for responding to obesity' (see: http://www.sussex.ac.uk/spru/PorGrow). The most recent statistical data on the spread of overweight and obesity in Italian society reveal that the phenomenon has reached a dimension that, albeit not as serious as in other Western countries, constitutes a serious threat to public health and to the national budget. The panel of stakeholders interviewed for this research showed awareness of this issue and generally agreed on the necessity to adopt a very multifaceted portfolio of policy measures to address the problem. Participants frequently regarded educational policies as the highest priority, followed by informational measures and infrastructural actions. Fiscal policy options were widely considered ineffective and unacceptable, and little enthusiasm was shown for technological innovations. In sum, while interviewees saw a real need for improved food habits on the part of Italian citizens, nonetheless in a country affected by many criticalities, the weakness of political will and the pressure of fast food culture remain severe obstacles in the fight against overweight and obesity.

Inhibition of CFU-E/BFU-E and CFU-GM colony growth by Cyclophosphamide, 5-Fluorouracil and Taxol: development of a high-throughput in vitro method

The major side effect of anticancer drugs is damage to the hematopoietic system. These compounds may interfere with cell proliferation and differentiation in different blood lineages causing many diseases such as neutropenia, aplastic anaemia or trombocytopenia. The clonogenic assays are useful in vitro tools for evaluating and predicting acute xenobiotics myelotoxicity. A miniaturisation of these assays, in order to reduce costs and increase the number of compounds that could be tested, is under investigation. The in vitro sensitivity of human burst-forming unit erythroid (BFU-E) and colony-forming unit granulocyte-macrophage (CFU-GM) to three anticancer drugs: cyclophosphamide (CTX), 5-fluorouracil (5-FU) and taxol (TAX) was evaluated both in 35 mm plate and 96-well plate systems and the dose-response curves, IC50 values and IC90 values were compared. The correlation between in vitro data and clinical plasma levels confirms that severe hematotoxicity is the primary adverse effect of these drugs with an evident selectivity on erythroid progenitors for cyclophosphamide. IC50 and IC90 values, calculated on the basis of results obtained with the traditional assay, correlate with those obtained in microplate, as well as the dose-response curves, indicating that the 96 well plate assay could be a useful and reliable tool for high-throughput screening in early stages of drug development.

Complete 1H and 13C NMR spectral assignment of 17-hydroxy epimeric sterols with planar A or A and B rings

Complete 1H and 13C spectral assignments of 17beta- and 17alpha-hydroxy epimers of three biologically active sterols (boldenone, 3-methoxyestradiol and 3-methoxydihydroequilenin) were achieved making use of one- and two-dimensional NMR techniques (1D-HOHAHA, DEPT, COSY, NOESY, TOCSY, HSQC and COLOC).

Application of the CFU-GM assay to predict acute drug-induced neutropenia: an international blind trial to validate a prediction model for the maximum tolerated dose (MTD) of myelosuppressive xenobiotics

In a previous study of prevalidation, a standard operating procedure (SOP) for two independent in vitro tests (human and mouse) had been developed, to evaluate the potential hematotoxicity of xenobiotics from their direct and the adverse effects on granulocyte-macrophages (CFU-GM). A predictive model to calculate the human maximum tolerated dose (MTD) was set up, by adjusting a mouse-derived MTD for the differential interspecies sensitivity. In this paper, we describe an international blind trial designed to apply this model to the clinical neutropenia, by testing 20 drugs, including 14 antineoplastics (Cytosar-U, 5-Fluorouracil, Myleran, Thioguanine, Fludarabine, Bleomycin, Methotrexate, Gemcitabine, Carmustine, Etoposide, Teniposide, Cytoxan, Taxol, Adriamycin); two antivirals (Retrovir, Zovirax,); three drugs for other therapeutic indications (Cyclosporin, Thorazine, Indocin); and one pesticide (Lindane). The results confirmed that the SOP developed generates reproducible IC90 values with both human and murine GM-CFU. For 10 drugs (Adriamycin, Bleomycin, Etoposide, Fludarabine, 5-Fluorouracil, Myleran, Taxol, Teniposide, Thioguanine, and Thorazine), IC90 values were found within the range of the actual drug doses tested (defined as the actual IC90). For the other 10 drugs (Carmustine, Cyclosporin, Cytosar-U, Cytoxan, Gemcitabine, Indocin, Lindane, Methotrexate, Retrovir, and Zovirax) extrapolation on the regression curve out of the range of the actual doses tested was required to derive IC90 values (extrapolated IC90). The model correctly predicted the human MTD for 10 drugs out of 10 that had "actual IC90 values" and 7 drugs out of 10 for those having only an extrapolated IC90. Two of the incorrect predictions (Gemcitabine and Zovirax) were within 6-fold of the correct MTD, instead of the 4-fold range required by the model, whereas the prediction with Cytosar-U was approximately 10-fold in error. A possible explanation for the failure in the prediction of these three drugs, which are pyrimidine analogs, is discussed. We concluded that our model correctly predicted the human MTD for 20 drugs out of 23, since the other three drugs (Topotecan, PZA, and Flavopiridol) were tested in the prevalidation study. The high percentage of predicitivity (87%), as well as the reproducibility of the SOP testing, confirm that the model can be considered scientifically validated in this study, suggesting promising applications to other areas of research in developing validated hematotoxicological in vitro methods.

Refinement of the colony-forming unit-megakaryocyte (CFU-MK) assay for its application to pharmaco-toxicological testing

In vitro colony-forming unit (CFU) assays can be used in the evaluation of potentially haematotoxic compounds during preclinical testing. The use of undifferentiated haematopoietic cells, able to proliferate and commit towards a specific blood cell lineage, enable selective toxicity to be detected. We optimized the colony-forming unit-megakaryocyte (CFU-MK) assay for toxicological applications. We used a collagen-based colony-forming assay to examine the sensitivity of four cell types: mononuclear human cord blood cells (CBC), mononuclear human bone marrow cells (BMC), cord blood enriched CD34+CD38- cells, and bone marrow enriched CD34+CD38- cells, to the toxic effects of five drugs known to cause thrombocytopenia in humans. The enrichment of CD34+CD38- cells was achieved by using a negative cell separation technique. Our results showed that a comparable toxicity was detected both with CBC, BMC and CD34+CD38- cells enriched from cord blood, whereas CD34+CD38- cells from bone marrow were more resistant to some drugs. The assay showed a high reproducibility of the endpoint measured (IC(50)), independently of the cell type used and donor source. The present study demonstrates that the refined CFU-MK assay is reproducible and can be used for in vitro toxicology studies with CBC as well as BMC.

Prevalidation of a model for predicting acute neutropenia by colony forming unit granulocyte/macrophage (CFU-GM) assay

This report describes an international prevalidation study conducted to optimise the Standard Operating Procedure (SOP) for detecting myelosuppressive agents by CFU-GM assay and to study a model for predicting (by means of this in vitro hematopoietic assay) the acute xenobiotic exposure levels that cause maximum tolerated decreases in absolute neutrophil counts (ANC). In the first phase of the study (Protocol Refinement), two SOPs were assessed, by using two cell culture media (Test A, containing GM-CSF; and Test B, containing G-CSF, GM-CSF, IL-3, IL-6 and SCF), and the two tests were applied to cells from both human (bone marrow and umbilical cord blood) and mouse (bone marrow) CFU-GM. In the second phase (Protocol Transfer), the SOPs were transferred to four laboratories to verify the linearity of the assay response and its interlaboratory reproducibility. After a further phase (Protocol Performance), dedicated to a training set of six anticancer drugs (adriamycin, flavopindol, morpholino-doxorubicin, pyrazoloacridine, taxol and topotecan), a model for predicting neutropenia was verified. Results showed that the assay is linear under SOP conditions, and that the in vitro endpoints used by the clinical prediction model of neutropenia are highly reproducible within and between laboratories. Valid tests represented 95% of all tests attempted. The 90% inhibitory concentration values (IC(90)) from Test A and Test B accurately predicted the human maximum tolerated dose (MTD) for five of six and for four of six myelosuppressive anticancer drugs, respectively, that were selected as prototype xenobiotics. As expected, both tests failed to accurately predict the human MTD of a drug that is a likely protoxicant. It is concluded that Test A offers significant cost advantages compared to Test B, without any loss of performance or predictive accuracy. On the basis of these results, we proposed a formal Phase II validation study using the Test A SOP for 16-18 additional xenobiotics that represent the spectrum of haematotoxic potential.

Inhibition of CFU-E/BFU-E by 3'-azido-3'-deoxythymidine, chlorpropamide, and protoporphirin IX zinc (II): a comparison between direct exposure of progenitor cells and long-term exposure of bone marrow cultures

Erythropoiesis occurs in two stages: proliferation amplifies cell number, and differentiation stimulates the acquisition of the functional properties of red blood cells. The erythroid colony-forming unit (CFU-E) amplifies the differentiation process in response to erythropoietic stress in vitro, whereas the burst-forming unit (BFU-E), which is not particularly sensitive to erythropoietin stimulation, gives rise to the CFU-E and, when stimulated, produces morphologically-identifiable erythroid colonies. The aim of this work was to evaluate the toxic effects of the antiviral agent, 3'-azido-3'-deoxythymidine (AZT), the antidiabetic drug, chlorpropamide (CLP), and the heme-analogous compound, protophorphirin IX zinc (II) (ZnPP), on the proliferation of erythroblastic progenitors by using human umbilical-cord blood cells and murine progenitors from long-term bone marrow cultures. All these agents may interfere with the hemopoietic process, causing myelotoxicity as an adverse effect via different mechanisms. Our results showed selective toxicity of the three drugs on the erythroid progenitors (IC(50): AZT 0.35 +/- 0.13 microM, ZnPP 23.34 +/- 1.16 microM, CLP 1.07 +/- 0.27 mM), with respect to the myeloid progenitors (IC(50): AZT 0.8 microM, ZnPP 103.9 +/- 3.9 microM and CLP > 2800 microM). The IC(50) values were well correlated with peak plasma levels reached in vivo by the drugs. There was a marked similarity between the drug sensitivities of the human and murine progenitors but differences in toxicity exerted by the drugs on the basis of the time of exposure. Drug treatment of long-term cultures, followed by the clonogenic assay of progenitors collected from them in the absence of the drugs, generally resulted in a lower hematotoxicity.

Comparison of in vitro drug-sensitivity of human granulocyte-macrophage progenitors from two different origins: umbilical cord blood and bone marrow

Predictive in vitro hematotoxicity assays using human cells will provide estimation of tolerable level and aid considerably the development of agents with greater therapeutic activity and less toxicity. Human hematopoietic cells can be derived from three sources: human bone marrow by sternal or femoral aspiration, mobilized peripheral blood, or umbilical cord blood samples collected from placentas after deliveries. Because of the difficulties to have a continuous supply of bone marrow cells from normal human donors and the related ethical problems, we performed a study to compare the sensitivity of human bone marrow cells (h-BMC) and human cord blood cells (h-CBC) to chemicals in order to confirm if h-CBC can readily replace bone marrow cells in checking the sensitivity of GM-CFU progenitors to drugs as preliminarily reported in literature. Our results showed that the prediction of IC50 values in human model is quite similar by using h-BMC or h-CBC. On the contrary, the type of medium influenced in a significant way the ICs determination of some drugs.

Lipase-catalyzed protection of the hydroxy groups of the nucleosides inosine and 2'-deoxyinosine: a new chemoenzymatic synthesis of the antiviral drug 2',3'-dideoxyinosine

The selective acylation of the hydroxy groups of the nucleosides inosine 1a and 2'-deoxyinosine 1b has been achieved in the presence of Candida antarctica and Pseudomonas sp. lipases in organic solvents; starting from the 5'-acetyl derivative of 2'-deoxyinosine, compound 5a, an efficient chemoenzymatic synthesis of the antiviral drug 2',3'-dideoxyinosine 1c has been achieved.

In vitro myelotoxicity of environmental contaminants

Myelotoxicity of pesticides and algal toxins was detected in vitro by using the granulocyte-macrophage colony forming unit assay (CFU-GM), and the MTT test with SR-4987 cells, an established stromal cell line derived from a long term murine bone marrow culture, which may represent a suitable in vitro model for studying haematotoxicity. Comparison of the IC50s and NOELs obtained with the CFU-GM assay and those determined by testing the established stromal cells in the MTT cytotoxicity test indicate that inhibition of the proliferation of SR-4987 stromal cells is a sensitive in vitro endpoint for measuring myelotoxicity. It is suggested that this assay could be used as rapid and easy screening test for determining the haematotoxicity of environmental toxins. A comparison with results obtained with the MTT test on a non-differentiated cell line, 3T3-L1, was carried out to distinguish between non-specific interference with cell proliferation and specific toxicity on haemopoietic cells.

Modulation of proto-oncogene expression by polychlorinated biphenyls in 3T3-L1 cell line

The effects of two substituted polychlorinated biphenyls, the 3,4,5,3',4,5' (PCB-169) and the 2,3,4,2',4',5' (PCB-138) forms, were examined on the expression of c-myc, c-jun, c-ras, and jun-b in 3T3-L1 cells. Northern blot analysis demonstrated that the two PCBs, which exhibit a coplanar and di-ortho-substituted configuration, activated these oncogenes differently. PCB-138 markedly induced overexpression of ras, jun, and myc, whereas PCB-169 led to the overexpression of jun-b. High-performance liquid chromatography analysis of the cell samples treated in medium without serum revealed a higher intracellular concentration of the 2,3,4,2',4',5'-hexachlorobiphenyl (hexaCB), whereas the 3,4,5,3',4'5'-hexaCB reached the same concentration in the sonicated samples of cells with or without serum. These results indicated that there was a relationship between PCB structure, bioavailability, and the capacity to stimulate oncogene expression.

13th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC): alternative testing methodologies and conceptual issues

Substantial world-wide resources are being committed to develop improved toxicological testing methods that will contribute to better protection of human health and the environment. The development of new methods is intrinsically driven by new knowledge emanating from fundamental research in toxicology, carcinogenesis, molecular biology, biochemistry, computer sciences, and a host of other disciplines. Critical evaluations and strong scientific consensus are essential to facilitate adoption of alternative methods for use in the safety assessment of drugs, chemicals, and other environmental factors. Recommendations to hasten the development of new alternative methods included increasing emphasis on the development of mechanism-based methods, increasing fundamental toxicological research, increasing training on the use of alternative methods, integrating accepted alternative methods into toxicity assessment, internationally harmonizating chemical toxicity classification schemes, and increasing international cooperation to develop, validate, and gain acceptance of alternative methods.

[Factors limiting the correction of anemia with recombinant human erythropoietin]

The efficacy of recombinant human erythropoietin in correcting the anemia of the uraemic patient has been thoroughly confirmed. Iron deficiency, aluminum intoxication, severe hyperparathyroidism and infections are some of the main factors limiting patients' response to the drug. Worsening or de novo formation of arterial hypertension generally makes it necessary to diminish the degree of correction of anaemia. It is commonly accepted that anaemia should be only partially corrected and that the target haemoglobin level should be defined patient by patient.

Response of renal transplanted patients to oral calcium load

In a previous study we demonstrated that cyclosporin-treated renal transplanted patients have a reduced 1,25(OH)2D3 synthesis in comparison with azathioprine-treated transplanted patients. To assess the impact of this defect on intestinal calcium transport we compared the plasma calcium variation and the urinary calcium excretion in 14 cyclosporin-treated and in 12 azathioprine-treated patients, in fasting conditions and 4 hours after an oral calcium load (1 g). In ten cyclosporin patients we also correlated cyclosporin plasma values with plasma 1,25(OH)2D3 values before and after a 25(OH)D3 oral load. After the oral calcium load, plasma and urinary calcium increased significantly in the azathioprine group, while remaining unchanged in the cyclosporin group. A negative correlation between plasma concentrations of cyclosporin and the increment in 1,25(OH)2D3 after 25(OH)D3 oral load was also observed. Thus, our data suggest that cyclosporin impairs 1-alpha hydroxylase activity and alters the response to an oral calcium load.

Aluminium interference in the treatment of haemodialysis patients with recombinant human erythropoietin

In nine chronic haemodialysis patients a desferrioxamine (DFO) load test (40 mg/kg body-weight) was performed 1 year after the beginning of treatment with recombinant human erythropoietin (rHuEpo). The patients were then divided into two groups. Group A comprised five patients with a greater mean aluminium (204 +/- 28 micrograms/l) than the four patients in group B. Group A was given a mean dose of 25.8 g (range 14-39 g) of DFO over 6 months. Group B (aluminium values 112 +/- 36 micrograms/l) was never treated with DFO. During the period of observation, plasma iron, serum ferritin and transferrin, as well as iron supplementation, did not differ between the groups. After DFO treatment a second DFO load test was performed. The mean predialysis aluminium value was significantly reduced in group A (204 +/- 28 vs 111 +/- 72 micrograms/l; P less than 0.05), while remaining unchanged in group B (112 +/- 36 vs 140 +/- 39 micrograms/l; P = ns). In both groups, the doses of rHuEpo necessary to maintain the same haemoglobin values decreased with time, but reduced significantly only in group A (298 +/- 105 vs 110 +/- 61 mu/kg per week; delta -63%; P less than 0.01). Thus, aluminium interferes with the response to rHuEpo in haemodialysis patients, and the correction of aluminium overload with DFO can allow a considerable sparing of rHuEpo.

Haemodialysis efficiency after long-term treatment with recombinant human erythropoietin

In 11 chronic haemodialysis patients we investigated whether the increase in haematocrit during recombinant human erythropoietin (rHuEPO) treatment might alter the long-term efficiency of haemodialysis. After correction of anaemia with rHuEPO (mean Ht 35 +/- 2% vs 19 +/- 2% at baseline) (p 0.001), mean predialysis creatinine and urea did not change, while predialysis phosphate (1.77 +/- 0.38 vs 1.51 +/- 0.29 mmol/l) were significantly increased (p 0.01). In six of the 11 rHuEPO treated patients a post- versus pre-dialysis haemoconcentration (haematocrit 44% vs 35%) not attributable to different ultrafiltration regimes, was observed. In these 6 patients mean predialysis phosphate, creatinine and urea tended to be higher, but not significantly, in comparison to he remaining 5 patients who did not haemoconcentrate. Dialyser clearances and total extractions for urea, creatinine, phosphate and inulin were compared to those of 11 matched haemodialysis patients with anaemia. No differences were observed either for small and middle molecule clearances or their extractions between rHuEPO and anaemic patients. In conclusion, dialysis efficiency is not affected if haematocrit values are kept about 35%.

Death from cardiovascular disease in Italy, 1972-1981: decline in mortality rates and possible causes

Mortality rates for cardiovascular disease vary widely between countries, and epidemiological patterns (trends in incidence rates, prevalence of risk factors, availability of medical care) are heterogeneous even among industrialized nations. We studied mortality from cardiovascular disease in Italy from 1972 to 1981 and compared mortality to trends in risk factors during the same period. Age-adjusted mortality rates for acute ischaemic heart disease (IHD) have increased in Italy from 1972 to reach a peak in 1978 (180.53/100,000 in males, 51.55/100,000 in females), then declined between 1978 and 1981, by 7% in males and 5% in females. The decline was more evident in males and in the younger age groups. Deaths from chronic IHD reached a peak in 1973 in females and in 1975 in males, then decreased, respectively by 24.8% and 35.7% until 1981. Mortality for cerebrovascular disease declined from 1972 to 1981 by 16.2% in males and 21.5% in females. Data from national statistics and sample surveys in different areas of Italy show an increase in total calorie intake, in animal proteins, fats and dairy products and raised average serum cholesterol levels plus an increase in smoking prevalence but a possible decline in blood pressure levels. The roles of hypertension treatment and of access to specialized medical care are discussed as possible contributors to the new declining trend of IHD, and the need is stressed for preventive strategies in health promotion.

Improvement in the haemostatic defect of uraemia after treatment with recombinant human erythropoietin

Patients with uraemia have a defect of primary haemostasis expressed as long skin bleeding times and reduced platelet adhesion to the arterial subendothelium. Transfusion of red cells shortens the bleeding time and stops bleeding symptoms in uraemia. This study investigated whether the efficacy of recombinant human erythropoietin in correcting anaemia and the improvement in haemostasis are correlated. Recombinant human erythropoietin was given to seven consecutive patients with chronic uraemia, a history of bleeding, severe anaemia (haematocrit below 23%), and long bleeding times (above 19 min). The progressive rise in haematocrit induced by increasing doses of recombinant human erythropoietin was paralleled by a pronounced shortening of the bleeding time. Platelet adhesion to the subendothelium of human umbilical arteries, very low before the study, increased greatly in all patients and became normal in six. None of the patients bled during the study period.

Benefits and risks of protracted treatment with human recombinant erythropoietin in patients having haemodialysis

Fourteen patients with uraemic anaemia and having regular haemodialysis were given human recombinant erythropoietin in increasing doses, beginning with 24 U/kg thrice weekly. One patient was dropped from the study because of recurrent thrombosis of vascular access sites. In the other 13 patients, followed up for a mean of 9.1 months (range 8-11), haemoglobin concentrations increased from 62 (SD 8) to 105 (9) g/l. No antierythropoietin antibodies were detected during the study. The correction of anaemia was associated with a tendency to hyperkalaemia and a mild increase of unconjugated bilirubinaemia. In eight previously hypertensive patients antihypertensive treatment had to be reinforced, but in normotensive patients blood pressure did not change. Thrombosis of arteriovenous fistulas occurred in two patients and a cerebral ischaemic lesion in one. Protracted treatment with human recombinant erythropoietin evidently can maintain normal haemoglobin concentrations in uraemic patients over time. Full correction of anaemia, however, may trigger some vascular problems, particularly in hypertensive patients and those with a tendency to thromboembolism.

Extrarenal synthesis of 1,25-dihydroxyvitamin D: sensitivity to glucocorticoid treatment

The response of circulating 1,25-dihydroxyvitamin D [1,25-(OH)2D] to challenge with vitamin D treatment both before and after 7-10 days of prednisone therapy (25 mg/day) was investigated in five anephric subjects, six patients with chronic renal failure (CRF), two patients with vitamin D intoxication and four patients with hypoparathyroidism. In anephric subjects serum 25-hydroxyvitamin D [25-(OH)D] rose from 58 +/- 48 (SD) to 377 +/- 221 (SD) nmol/l after administration of 150 micrograms of 25-(OH)D3 for 1 month. Serum 1,25-(OH)2D, which was barely detectable in only two out of five patients under basal conditions, rose to 30 +/- 21 pmol/l after 2 weeks of therapy with 25-(OH)D3, but fell to 10 +/- 5 pmol/l during prednisone treatment. In CRF patients circulating 1,25-(OH)2D rose from 37 +/- 24 to 58 +/- 24 pmol/l during 25-(OH)D3 therapy, but fell to 41 +/- 31 pmol/l during prednisone treatment. In two patients with rheumatoid arthritis, hypercalcaemia due to vitamin D intoxication was associated with raised levels of 1,25-(OH)2D (288 and 317 pmol/l). Administration of prednisone resulted in suppression of 1,25-(OH)2D levels (132 and 96 pmol/l respectively) and reduction of serum calcium to within the normal range. In the hypoparathyroid patients prednisone therapy did not affect circulating 25-(OH)D levels but serum 1,25-(OH)2D fell from 192 +/- 42 to 117 +/- 23 pmol/l and serum calcium from 2.41 +/- 0.21 to 2.20 +/- 0.05 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

High plasma levels of protein C activity and antigen in the nephrotic syndrome

Low plasma levels of antithrombin III due to excessive urinary loss are thought to be the cause of thrombotic complications in patients with the nephrotic syndrome. To see whether protein C (PC), another antithrombotic protein, is also reduced in plasma by the same mechanism, plasma and urinary protein C were determined in 24 patients with nephrotic syndrome and no thrombotic complication, and compared to plasma and urinary antithrombin III. Twenty patients (83%) had high plasma levels of protein C activity (mean +/- SD 157 +/- 41 U/dl) and antigen (158 +/- 41). Even though measurable amounts of PC antigen were found in the urines of all but two patients the urinary loss of protein C relative to its plasma concentration was about 40 times lower than that of antithrombin III. High protein C might help to counteract hypercoagulability in nephrotic syndrome.

Treatment of arterial hypertension with nifedipine in patients with chronic renal insufficiency

The acute and chronic antihypertensive effects of nifedipine were investigated in patients with chronic renal insufficiency (CRI). The acute effects were assessed after the administration either of a fast-release nifedipine capsule or a slow-release nifedipine tablet in 10 and 15 patients respectively. Both the preparations induced prompt and marked reduction of systolic and of diastolic blood pressure, but the capsules showed a shorter antihypertensive effect (2 hours) than tablets (more than 6 hours). The chronic effects of nifedipine tablets given in addition to the previous therapy was assessed in 25 patients with CRI and resistant hypertension. Both systolic and diastolic blood pressure values promptly fell and maintained within the normal range over the whole period of the study (12 months).

Branched chain and aromatic free amino acids in plasma and skeletal muscle of uremic patients undergoing hemodialysis and CAPD

Plasma and skeletal muscle free amino acids were measured in patients submitted to Hemodialysis (HD) or Continuous Ambulatory Peritoneal Dialysis (CAPD) in order to evaluate the effects of these different dialysis modalities on amino acid pools; the data were compared with those obtained in control subjects and in patients with advanced Chronic Renal Failure (CRF) not submitted to Regular Dialysis Treatment (RDT). Our findings show low intracellular concentrations of VAL, total Branched Chain Amino Acid (BCAA) and TYR in uremic patients treated with CAPD but not in those undergoing HD. The observed differences in muscle amino acid pattern could be well explained by a changed amino acid metabolism regulation in CAPD, possibly related to the sustained hyperinsulinism and to an increased rate of hepatic protein synthesis.

Hemodialysis without anticoagulants: efficiency and hemostatic aspects

In 29 patients with high risk of bleeding, 111 hemodialyses have been performed without heparin (WHD) or other anticoagulants. The same patients were switched to low dose heparin dialysis (LDHD) as soon as the bleeding risk had ceased. The dialyzer had to be changed in 11 and the drip chamber in 20 WHDs because of partial clotting. This phenomenon did not occur during LDHD. The comparative efficiencies of the two techniques were evaluated by measuring the urea and creatinine clearances of the dialyzers. No significant difference between LDHD and WHD clearances was observed. In 7 of 29 patients, hemostasis variables were studied before, during and after both modes of treatment. Fibrinogen, platelet count, antithrombin III and prothrombin time did not differ with the different dialysis procedures. During dialysis, platelet factor 4 (PF4) levels were significantly higher than baseline values (P less than 0.01), with no difference between WHD and LDHD. Plasma fibrinopeptide A (FPA) levels remained normal during LDHD, but significantly increased during WHD (P less than 0.001). Our data indicate that WHD is feasible, with a low risk of extravascular coagulation. The bleeding risk is not increased during or after dialysis, and the danger of intravascular coagulation is low as confirmed by the isolated elevation of FPA plasma levels, unaccompanied by changes in other variables.

Dopamine and frusemide in oliguric acute renal failure

Into 24 oliguric patients with acute renal failure (ARF) for whom mannitol and high-dose frusemide had failed to promote a diuresis, dopamine (3 micrograms/kg/min) plus frusemide (10-15 mg/kg/h) were infused for 6-24 h. In 19 of the 24 patients this treatment produced significant increases in diuresis (from 11 +/- 7 to 85 +/- 51 ml/h; p less than 0.001) and natriuresis (from 45 +/- 13 to 88 +/- 22 mEq/1; p less than 0.001), without any significant modification of blood pressure, pulse rate or central venous pressure. 10 of the 24 patients required dialysis: 5 because therapy failed to promote diuresis and the other 5 because of their hypercatabolic state in spite of polyuria. 5 patients died of causes unrelated to ARF. Since all patients who responded were treated within 24 h after the onset of oliguria, it appears to be crucial to administer dopamine and frusemide early, before more severe anatomical and functional damage develops.