Distinct and targetable role of calcium-sensing receptor in leukaemia

Haematopoietic stem cells (HSC) reside in the bone marrow microenvironment (BMM), where they respond to extracellular calcium [eCa2+] via the G-protein coupled calcium-sensing receptor (CaSR). Here we show that a calcium gradient exists in this BMM, and that [eCa2+] and response to [eCa2+] differ between leukaemias. CaSR influences the location of MLL-AF9+ acute myeloid leukaemia (AML) cells within this niche and differentially impacts MLL-AF9+ AML versus BCR-ABL1+ leukaemias. Deficiency of CaSR reduces AML leukaemic stem cells (LSC) 6.5-fold. CaSR interacts with filamin A, a crosslinker of actin filaments, affects stemness-associated factors and modulates pERK, β-catenin and c-MYC signaling and intracellular levels of [Ca2+] in MLL-AF9+ AML cells. Combination treatment of cytarabine plus CaSR-inhibition in various models may be superior to cytarabine alone. Our studies suggest CaSR to be a differential and targetable factor in leukaemia progression influencing self-renewal of AML LSC via [eCa2+] cues from the BMM.

The age of the bone marrow microenvironment influences B-cell acute lymphoblastic leukemia progression via CXCR5-CXCL13

B-cell acute lymphoblastic leukemia (B-ALL) occurs most commonly in children, whereas chronic myeloid leukemia is more frequent in adults. The myeloid bias of hematopoiesis in elderly individuals has been considered causative, but the age of the bone marrow microenvironment (BMM) may be contributory. Using various murine models of B-ALL in young vs old mice, we recapitulated B-ALL preponderance in children vs adults. We showed differential effects of young vs old BM macrophages on B-ALL cell function. Molecular profiling using RNA- and ATAC-sequencing revealed pronounced differences in young vs old BMM-derived macrophages and enrichment for gene sets associated with inflammation. In concordance with the role of C-X-C motif chemokine (CXCL) 13 for disease-associated B-cell chemoattraction, we found CXCL13 to be highly expressed in young macrophages on a translational compared with a transcriptional level. Inhibition of CXCL13 in BM macrophages impaired leukemia cell migration and decreased the proliferation of cocultured B-ALL cells, whereas recombinant CXCL13 increased pAKT and B-ALL cell expansion. Pretreatment of B-ALL-initiating cells with CXCL13 accelerated B-ALL progression. Deficiency of Cxcr5, the receptor for CXCL13, on B-ALL-initiating cells prolonged murine survival, whereas high expression of CXCR5 in pediatric B-ALL may predict central nervous system relapse. CXCL13 staining was increased in bone sections from pediatric compared with adult patients with B-ALL. Taken together, our study shows that the age of the BMM and, in particular, BM macrophages influence the leukemia phenotype. The CXCR5-CXCL13 axis may act as prognostic marker and an attractive novel target for the treatment of B-ALL.

"Caught in the net": the extracellular matrix of the bone marrow in normal hematopoiesis and leukemia

The influence of the bone marrow microenvironment on normal hematopoiesis, but also leukemia, has largely been accepted. However, the focus has been predominantly on the role of various cell types or cytokines maintaining hematopoietic stem cells or protecting leukemia stem cells from different therapies. A frequently overlooked component of the bone marrow microenvironment is the extracellular matrix, which not only provides a mechanical scaffold, but also serves as a source of growth factors. We discuss here how extracellular matrix proteins directly or indirectly modulate hematopoietic stem cell physiology and influence leukemia progression. It is hoped that existing and future studies on this topic may propel forward the possibility of augmenting normal hematopoiesis and improving therapies for leukemia, for instance, by targeting of the extracellular matrix in the bone marrow.

Specific, targetable interactions with the microenvironment influence imatinib-resistant chronic myeloid leukemia

Therapy resistance in leukemia may be due to cancer cell-intrinsic and/or -extrinsic mechanisms. Mutations within BCR-ABL1, the oncogene giving rise to chronic myeloid leukemia (CML), lead to resistance to tyrosine kinase inhibitors (TKI), and some are associated with clinically more aggressive disease and worse outcome. Using the retroviral transduction/transplantation model of CML and human cell lines we faithfully recapitulate accelerated disease course in TKI resistance. We show in various models, that murine and human imatinib-resistant leukemia cells positive for the oncogene BCR-ABL1T315I differ from BCR-ABL1 native (BCR-ABL1) cells with regards to niche location and specific niche interactions. We implicate a pathway via integrin β3, integrin-linked kinase (ILK) and its role in deposition of the extracellular matrix (ECM) protein fibronectin as causative of these differences. We demonstrate a trend towards a reduced BCR-ABL1T315I+ tumor burden and significantly prolonged survival of mice with BCR-ABL1T315I+ CML treated with fibronectin or an ILK inhibitor in xenogeneic and syngeneic murine transplantation models, respectively. These data suggest that interactions with ECM proteins via the integrin β3/ILK-mediated signaling pathway in BCR-ABL1T315I+ cells differentially and specifically influence leukemia progression. Niche targeting via modulation of the ECM may be a feasible therapeutic approach to consider in this setting.

Vitamin K antagonism impairs the bone marrow microenvironment and hematopoiesis

Vitamin K antagonists (VKAs) have been used in 1% of the world's population for prophylaxis or treatment of thromboembolic events for 64 years. Impairment of osteoblast function and osteoporosis has been described in patients receiving VKAs. Given the involvement of cells of the bone marrow microenvironment (BMM), such as mesenchymal stem cells (MSCs) and macrophages, as well as other factors such as the extracellular matrix for the maintenance of normal hematopoietic stem cells (HSCs), we investigated a possible effect of VKAs on hematopoiesis via the BMM. Using various transplantation and in vitro assays, we show here that VKAs alter parameters of bone physiology and reduce functional HSCs 8-fold. We implicate impairment of the functional, secreted, vitamin K-dependent, γ-carboxylated form of periostin by macrophages and, to a lesser extent, MSCs of the BMM and integrin β3-AKT signaling in HSCs as at least partly causative of this effect, with VKAs not being directly toxic to HSCs. In patients, VKA use associates with modestly reduced leukocyte and monocyte counts, albeit within the normal reference range. VKAs decrease human HSC engraftment in immunosuppressed mice. Following published examples that alteration of the BMM can lead to hematological malignancies in mice, we describe, without providing a causal link, that the odds of VKA use are higher in patients with vs without a diagnosis of myelodysplastic syndrome (MDS). These results demonstrate that VKA treatment impairs HSC function via impairment of the BMM and the periostin/integrin β3 axis, possibly associating with increased MDS risk.

Diverging impact of cell fate determinants Scrib and Llgl1 on adhesion and migration of hematopoietic stem cells

PURPOSE

Cell fate determinants Scrib and Llgl1 influence self-renewal capacity of hematopoietic stem cells (HSCs). Scrib-deficient HSCs are functionally impaired and lack sufficient repopulation capacity during serial transplantation and stress. In contrast, loss of Llgl1 leads to increased HSC fitness, gain of self-renewal capacity and expansion of the stem cell pool. Here, we sought to assess for shared and unique molecular functions of Llgl1 and Scrib by analyzing their interactome in hematopoietic cells.

METHODS

Interactome analysis was performed by affinity purification followed by mass spectrometry. Motility, migration and adhesion were assessed on primary murine HSCs, which were isolated by FACS sorting following conditional deletion of Scrib or Llgl1, respectively. Imaging of Scrib-deficient HSCs was performed by intravital 2-photon microscopy.

RESULTS

Comparison of Scrib and Llgl1 interactome analyses revealed involvement in common and unique cellular functions. Migration and adhesion were among the cellular functions connected to Scrib but not to Llgl1. Functional validation of these findings confirmed alterations in cell adhesion and migration of Scrib-deficient HSCs in vitro and in vivo. In contrast, genetic inactivation of Llgl1 did not affect adhesion or migratory capacity of hematopoietic stem cells.

CONCLUSION

Our data provide first evidence for an evolutionarily conserved role of the cell fate determinant Scrib in HSC adhesion and migration in vitro and in vivo, a unique function that is not shared with its putative complex partner Llgl1.

Impact of drug-eluting stent generation on patient- and stent-related adverse events of diabetic patients treated by percutaneous coronary intervention

AIM

Aim of the present study was to assess stent- and patient-related outcomes of the first- vs. second-generation drug-eluting stents (DES) in diabetics, according to the insulin requirement status.

METHODS

Data were obtained from a prospective, single-center registry of 816 consecutive patients with diabetes mellitus (23% insulin-requiring) who underwent percutaneous coronary intervention (PCI) between April 2003 and May 2012 with first- (N.=534) or second-generation DES (N.=282) at our Institution, with at least 12 months of follow-up. We assessed the occurrence of stent-related outcome, including cardiac death, target vessel-related myocardial infarction and target lesion revascularization, versus patient-related outcome, including any cause death, any myocardial infarction and any coronary revascularization.

RESULTS

Patients treated with second-generation DES were older and had more complex lesions than patients treated with first-generation DES. Both among patients treated with first-generation DES and those treated with second generation DES, patient-related events were almost double than stent-related events. No interactions were observed between the DES generation type and insulin requirement status.

CONCLUSION

In this observational study, first- and second-generation DES were equally safe and efficacious in diabetic patients undergoing PCI, regardless of insulin requirements. The greater number of patient-related than stent-related events in patients with complex clinical and lesion characteristics emphasizes that the optimization of secondary prevention is at least as important as the selection of which new generation DES to implant in a specific lesion.

Production and characterisation of monoclonal antibodies for the quantification of potentially allergenic xylanase from Aspergillus niger

Xylanase from Aspergillus niger (ANX) is widely used in bakeries as a processing aid since it stabilises and improves dough quality. An association between allergic symptoms among bakery workers and sensitisation to ANX has been reported, indicating that this enzyme is an occupational allergen. The presence of ANX in dough improvers and semi-finished goods is often hidden due to incomplete and unclear labelling. The quantification of microbial enzymes in these products is necessary and the determination of the actual concentration of ANX in workplaces is therefore essential to assess the occupational risk. To this purpose we have developed and characterised monoclonal antibodies to ANX. The monoclonal antibodies do not show any cross-reaction with other commonly used microbial enzymes, and they allow the detection of ANX in complex mixtures by ELISA inhibition assays down to the concentration limit of approximately 10 µg kg(-1). These mAbs are a valuable tool to detect and quantify ANX and to investigate its allergenic potential in the workplace.

[The role of exercise testing in the management of systemic sarcoidosis]

INTRODUCTION

Patients suffering from sarcoidosis sometimes report dyspnoea of effort. The restrictive or obstructive ventilatory problems contribute to this disability, but the systemic manifestations of sarcoidosis should be considered as other possible causes of the dyspnoea.

CASE REPORT

We report a case of systemic sarcoidosis in a 29 year old man from the Ivory Coast. The disorder presented in December 1999 with generalised symptoms and grade II dyspnoea (Sadoul). Investigations confirmed pulmonary, mediastinal, hepatic, lachrymal and salivary involvement. Lung function tests at rest showed a combined restrictive and obstructive ventilatory defect. The initial exercise test showed evidence of severe limitation of aerobic metabolism with impaired oxygen uptake without limitation of ventilation. The absence of cardiac involvement, confirmed by echocardiography and myocardial isotope scanning, suggested that the dyspnoea was, at least in part, secondary to a "peripheral" muscular abnormality. After 3 months treatment with oral corticosteroids, the clinical and physiological parameters improved. Exercise testing confirmed an improvement in maximum work rate and oxygen uptake. The relative stability of the functional measurements and the subsequent development of myalgia prompted a biopsy of the quadriceps that showed granulomata within the muscle tissue, confirming a sarcoid myopathy. A combination of steroids and methotrexate allowed the patient to increase his exercise capacity without any major change in the resting lung function tests.

CONCLUSIONS

This case report underlines the role of exercise testing in determining the cause of dyspnoea. In this patient it contributed to the diagnosis of sarcoid myopathy and lead to modification of his treatment.

[Intra-cavity aspergilloma complicating necrotising sarcoid granulomatosis]

INTRODUCTION

Necrotising sarcoid granulomatosis is a rare clinical entity, characterised by the development of nodular pulmonary opacities, the diagnosis if which is based on the identification of characteristic pathological lesions.

CASE REPORT

A 44-years-old male smoker presented with cough and fever. With the exception of a few basal crepitations clinical examination was normal. The chest x-ray showed multiple areas of alveolar consolidation scattered throughout both lung fields, some of which were cavitated. The thoracic CT scan confirmed the presence of cavitating nodules and hilar and mediastinal lymphadenopathy. Samples for mycobacteria were negative. A search for anti-neutrophil cytoplasmic antibodies was negative. Fibreoptic bronchoscopy was normal but transbronchial biopsies revealed giant cells. Lung biopsies taken by video thoracoscopy showed non-caseating granulomata with areas of fibrinoid necrosis and perivascular infiltration with lymphocytes, histology characteristic of necrotising sarcoid granulomatosis. Resolution occurred without treatment. The parenchymal lesions regressed leaving residual cavities. Four years later, following an episode of haemoptysis, the patient was found to have a squamous cell carcinoma (T1N0M0) and aspergillomas in the pulmonary cavities.

CONCLUSIONS

Our observation demonstrates that the cavities of necrotising sarcoid granulomatosis may be complicated by aspergillomas.

[Follow-up of latex-induced occupational asthma]

We studied 29 subjects with latex-induced occupational asthma in a follow-up of 5 +/- 3 years. Initial and follow-up visits included a questionnaire and measurement of lung volumes, bronchial responsiveness to methacholine (PD20FEV1), and latex-specific serum IgE levels. At follow-up, 17 subjects were no longer exposed to latex, whereas 12 subjects had reduced exposure. Asthma and rhinitis symptoms, use of steroids and bronchial hyperresponsiveness improved significantly at follow-up, whereas mean FEV1% and FVC% decreased (p < 0.05). Multiple regression analysis showed that the main determinant of FEV1 and PD20FEV1 at follow up were the values of these variables at diagnosis. Complete recovery of occupational asthma was observed in 7 subjects (24%), all in the non-exposed group. Latex-specific IgE did not exhibit significant changes. In conclusion latex-induced occupational asthma improves after a follow-up of 5 +/- 3 years, but a complete recovery occurs in a minority of subjects and is associated with cessation of exposure. Lung function measurements at follow up depend from their impairment at the time of diagnosis.

[Diseases in hospital workers]

Occupational diseases and labour accidents in health care workers (Azienda Ospedaliera di Padova) were evaluated from 1990 to 2000; the information collected is compared with the same data of Regione Veneto and INAIL. 262 occupational diseases were found; nurses are more affected than other health care workers. In both reports (Azienda Ospedaliera di Padova and Osservatorio epidemiologico della Regione Veneto) half of the occupational diseases and injuries are represented by allergic disease. Low back pain is also equally represented in Azienda Ospedaliera and in Osservatorio epidemiologico results (5.3% and 6.6% respectively). Among the labour accidents reported to INAIL from 1994 to 2000, 25% of them were represented by falls and slips, 23% by car accidents, 17% were caused by tools, 17% by movement of goods and persons, 8% by contact with splinters, liquids, dusts, 5% by assaults and 5% by contact with blood or body fluid. The latter result is widely underestimated in the INAIL report, because these events usually produce a temporary inability of less than 3 days; in fact, they represent more than half of the labour accidents treated at the Azienda Ospedaliera di Padova. Medical surveillance (in exposure to aldehydes, anaesthetic gases, chemioterapic drugs) has shown many other occupational health problems that often need specific structural intervention (restructuration and restoration of workplaces in health care environments), and work organization changes.

Susceptibility of healthcare workers to measles, mumps rubella and varicella

Susceptible healthcare workers are at risk of acquiring and transmitting measles, mumps, rubella and varicella to or from patients. We tested 333 employees at Padova University Hospital, for specific IgG. Of the workers tested, 98.2% were positive for measles, 85.9% for mumps, 97.6% for rubella and 97.9% for varicella. Eventhough participants born before 1957 were not all positive, they had a higher prevalence of immunity. We suggest serological screening in high-risk areas (paediatrics, oncology, radiotherapy, infectious diseases, maternity and the laboratory) and vaccination of susceptible employees.

Improvement of clonality detection rate in multiple myeloma using fluorescent IgH PCR with different sets of primers

The IgH rearrangement provides a useful marker of clonality in B-cell malignancies and amplification of this rearrangement is the method of choice to monitor the residual tumor cells in multiple myeloma (MM). The critical point of this analysis was the false-negative rate observed at diagnosis in patients presenting tumor cells well above the limit of detection. The aim of this study was therefore to increase the clonality detection rate by IgH polymerase chain reaction (PCR). Bone marrow DNA from 37 MM patients were analyzed at diagnosis. IgH PCR with agarose gel detection was performed between framework regions FR3 and FR1, both in combination with 5 different primers in FR4. Fluorescent IgH PCR with highly resolutive capillary electrophoresis was used to improve the detection and to size clonal PCR products. Sixty-two percent of the clonal rearrangements were initially detected with JHD primer specific to the JH segments 1,2,4,5. The use of JH3 and JH6 homologous primers increased the detection rate to 78%, whereas a consensus JH primer only reached 67% of positivity. The lowest detection rates were obtained with JHExt and JH3 with a detection of respectively 43 and 14%. However, three rearrangements were exclusively amplified by JHExt and two additional cases were detected by JH3. The combined use of primers yielded the best score with 89% of positivity. With Genescan analysis, two additional cases showed a monoclonal rearrangement improving the detection rate to 95%. The use of multiple sets of primers along with a highly sensitive genescan analysis makes possible the follow-up of minimal residual disease for most MM patients.

Human accessory cells have a humoral bystander effect on CAFC growing on murine feeder

Human early hematopoietic progenitors from bone marrow (BM) and leukapheresis products (LP) are highly proliferative in presence of accessory cells in standard culture on the murine FBMD-1 cell feeder with weekly addition of human interleukin-3 (HuIL-3) and granulocyte-colony stimulating factor (HuG-CSF). If however purified CD34+ cells are cultured under otherwise identical conditions, cobblestone areas (CAFC) formed by the same number of target cells are diminished by more than 1 log, as we showed previously. This suggests that mature cells are involved in growth of early progenitors. To determine whether this bystander effect is mediated by soluble growth factors, or by direct cell-to-cell contact with early progenitors, we stimulated mature plastic adherent cells separately and tested the resulting conditioned supernatant (ACS) on CAFC and colony-forming unit-granulocyte-macrophage (CFU-GM) production. In ACS-complemented standard cultures of purified CD34+ cells, the yield of CAFC was up to 1 log higher if compared to parallel cultures without ACS. Likewise, the CFU-GM production was enhanced in presence of ACS, especially in the adherent fraction of the culture. When CD34+ cell cultures were performed with ACS but without added interleukin-3 (IL-3) and granulocyte colony-stimulating factor (G-CSF), CAFC production was in the same range as if these growth factors were added alone. Addition of anti-G-CSF antibody (Ab) to ACS decreased CAFC recruitment significantly, whereas anti-IL-3 Ab had no significant effect. These findings suggest that ACS complemented with IL-3 and G-CSF replaces the accessory cells largely; this is not only due to presence of G-CSF, because ACS in combination with recombinant growth factors mounts CAFC yield higher than saturating amounts of growth factors alone do. There must be further synergizing soluble factors in the supernatant.

[Analysis of a preventive health service]

This paper reports the experience and organization of an Occupational Health Service for health-care workers, in order to improve the effectiveness of the unit. The Authors describe the activities of the unit, its organization, and evaluate the amount of working time spent in the different activities.

The PML/RARalpha fusion protein inhibits tumor necrosis factor-alpha-induced apoptosis in U937 cells and acute promyelocytic leukemia blasts

We investigated the effect of the acute promyelocytic leukemia (APL) specific PML/RARalpha fusion protein on the sensitivity to TNF-alpha-mediated apoptosis. The U937 leukemia cell line was transduced with PML/RARalpha cDNA. PML/RARalpha expression caused a markedly reduced sensitivity to TNF-alpha, even if apoptosis was triggered by agonistic antibodies to TNF-alpha receptors I and II (TNF-alphaRI, II). PML/RARalpha induced a 10-20-fold decrease of the TNF-alpha-binding capacity via downmodulation of both TNF-alphaRI and TNF-alphaRII: this may mediate at least in part the reduced sensitivity to TNF-alpha. Furthermore, the fusion protein did not modify Fas expression (CD95) or sensitivity to Fas-mediated apoptosis. The pathophysiological significance of these findings is supported by two series of observations. (a) Fresh APL blasts exhibit no TNF-alpha binding and are resistant to TNF-alpha-mediated apoptosis. Conversely, normal myeloblasts-promyelocytes show marked TNF-alphaR expression and are moderately sensitive to TNF-alpha-mediated cytotoxicity. Similarly, blasts from other types of acute myeloid leukemia (AML M1, M2, and M4 FAB types) show an elevated TNF-alpha binding. (b) The NB4 APL cell line, which is PML/RARalpha+, shows low TNF-alphaR expression capacity and is resistant to TNF-alpha-triggered apoptosis; conversely a PML/RARalpha- NB4 subclone (NB4.306) exhibits detectable TNF-alpha-binding capacity and is sensitive to TNF-alpha-mediated cytotoxicity. These studies indicate that the PML/RARalpha fusion protein protects against TNF-alpha-induced apoptosis, at least in part via downmodulation of TNF-alphaRI/II: this phenomenon may play a significant role in APL, which is characterized by prolonged survival of leukemic blasts.

In vitro toxicity and formation of early conjugates in Caco-2 cell line treated with clenbuterol, salbutamol and isoxsuprine

Caco-2, human intestinal cell line able to differentiate in long-term culture, has been used to assess the cytotoxicity of the beta-agonists clenbuterol, salbutamol and isoxsuprine, also used at high doses to obtain lean meat in food producing animals, and to investigate the eventual in vitro formation of early conjugates of these compounds. For this purpose, the cells have been characterized for the activity of UDP-glucuronyltransferase, which is present and increases in the differentiated cells, and for the beta-receptors' binding characteristics, which are those of beta 1 and beta 2 subtypes. Isoxsuprine was shown to be the most toxic, followed by clenbuterol and salbutamol. Conjugates have been observed after incubation of the cells both with the lowest isoxsuprine and the highest salbutamol concentrations. No conjugates were detected in the case of clenbuterol.

[Carcinogenic risk of extremely-low-frequency electromagnetic fields: state of the art]

This paper summarizes the published literature and current problems relating to possible cancerogenic effects of occupational and residential exposure to ELF electromagnetic fields at levels slightly above ambient background. There are several suggestions that such an exposure may increase the risk of cancer, but these studies failed to provide conclusive indications. The present state of uncertainty led to a variety of recommendations and statements being made concerning restrictions to the exposure of people to ELF electromagnetic fields. Attempts to detect direct chromosomal damage from ELF electromagnetic fields have proven negative, while results on cancer promotion have been controversial. On the basis of several epidemiological studies on occupational exposure, an increased risk of leukemia, brain cancer and male breast cancer is apparent; the literature on residential exposure provides some evidence of an effect on childhood cancer, especially leukemia; however, when interpreting these results some major methodological concerns should be kept in mind. In conclusion, the public concern and potential public health impact of this environmental agent argue strongly for addressing further research in order to identify mechanisms of action on biological systems, to define the proper assessment of exposure and to obtain good epidemiological evidence.

Post-emergency epidemiological surveillance in Iraqi-Kurdish refugee camps in Iran

In 1991 a computerized, comprehensive epidemiological surveillance system was developed to monitor health trends in approximately 25,000 acutely displaced Kurds in Nowsood and Saryas refugee camps, Bakhtaran region, Northwestern Iran. In addition, community-based surveys offered information unobtainable from health facilities. Weekly population movements, attack rates, point-prevalence estimates, and case fatality ratios were calculated, and the data were analysed and compared. The overall crude mortality rate (CMR) in the camps under study was still 9 times higher than the reported CMR for Iraq. Health problems with very low rates (less than 1.0/1,000 population/week) included the triad of measles, meningitis and tetanus. However, morbidity for the most common conditions (acute respiratory infections, diarrhoea, skin infections, eye diseases and, finally, typhoid fever) was shown to increase at the end of the intervention, highlighting that the pressure of repatriation on refugees made them progressively worse. This article concludes that epidemiological surveillance systems should be implemented during mass-migrations in developing countries also in post-emergency settings. Furthermore, surveillance appears to be indispensable in order for the international agencies to keep abreast of events and to safeguard human rights when international attention subsides.

In vitro model for the evaluation of toxicity and antinutritional effects of sulphites

The food preservatives, sulphur dioxide and its salts, are known to present some toxic, mutagenic and antinutritional effects; in fact they interact with a number of nutrients, e.g. some vitamins, notably thiamine (Th) and folic acid (FA). The effect of different concentrations of sodium bisulphite in cell culture media has been studied in vitro on a human cell line, HEp-2, deriving from a carcinoma of the larynx. Moreover, the sulphites have been tested with different levels of Th and FA with the aim of elucidating how much the cellular response depended on either the anti-nutritional effect or the toxicity of sulphites. Cell growth has been taken as an index of cytotoxicity and measured both as total protein content and as colony-forming ability. With no Th and FA in the culture medium, a clear decrease of cell growth was observed either with or without addition of sodium bisulphite. A dose-dependent reduction of protein content was detected in cells treated with 10, 50, 100, 200, 250 or 500 microM sodium bisulphite. Moreover, when the cells were treated with 10 or 100 microM of this compound, the colony-forming ability was reduced both in number and colony size. As far as the interaction of the two vitamins with sodium bisulphite is concerned, when these nutrients were present in the medium at 0.5, 1.0, 1.5, 2.0 or 2.5 mg/l, a similar growth profile, determined from their concentration, was observed in treated and control cells, the growth levels being affected by the sodium bisulphite contents. At higher levels of Th and FA, the growth index was still increasing only in treated cells, this phenomenon being particularly evident in cultures treated with 200 microM sodium bisulphite. The colony-forming ability was reduced in controls but still increased in treated cells at the highest concentration of vitamins.

Rabies-specific production of interleukin-2 by peripheral blood lymphocytes from human rabies vaccinees

Cell-mediated immunity induced by rabies vaccination was studied in humans by the determination of specific interleukin-2 (IL-2) production in a large number of donors (postexposure immunized patients and pre-exposure immunized laboratory workers). Peripheral blood lymphocytes (PBL) from 35 donors were tested for IL-2 production after in vitro stimulation by different rabies and rabies-related viruses. IL-2 responses were compared to antibody recognition of these different virus serotypes by sera from the same individuals. IL-2 was produced by PBL from more than 85% of donors after stimulation with inactivated and purified rabies viruses (IPRV) prepared from either Pittman Moore (PM) or Pasteur Virus (PV) strains. IL-2 was also produced by 65 and 45% of donor PBL stimulated with IPRV from the European Bat Lyssavirus (EBL) and Mokola (Mok) rabies-related virus strains respectively. No correlation was found between the production of IL-2 by PBL and the levels of virus neutralizing antibody (VNAb). Moreover, 50, 25 and 35% of donors produced IL-2 after stimulation of their PBL with ribonucleoprotein (RNP) from PV-, EBL- and Mok-viruses, respectively. These results obtained with a large number of human rabies vaccinees and using an assay specific to T-cell activation confirm the significant cross-reactivity of T-cell responses directed against rabies and rabies-related viruses. This study shows that IL-2 production could be used for the study of cell-mediated immunity and T-cell memory induced in humans by rabies vaccination.

Appraisal of rabies vaccine potency by determination of in vitro, specific interleukin-2 production

The potency of different rabies vaccines was measured via cell mediated immunity (CMI) assessed by the production of interleukin-2 (IL-2) by CD4+CD8- lymphocytes. IL-2 production by splenocytes from mice immunized with various vaccines was measured following in vitro stimulation with antigens from different rabies and rabies-related strains. IL-2 production was specific, reproducible and correlated with the vaccine protective activity as determined by the pre-exposure NIH test. Our results suggest that measurement of IL-2 production could be used for the appraisal of rabies vaccine potency.

Enhancement of interleukin-2 activity by liposomes

The present report demonstrates that liposomes increase the interleukin-2 (IL-2) dependent proliferation of cytotoxic T-lymphocyte line (CTLL) cells used for the measurement of IL-2 activity. This effect was better observed with suboptimal doses of IL-2 and low concentrations of lipids. The increased IL-2 dependent proliferation is not due to a direct effect of liposomes on CTLL cells but rather to an interaction between IL-2 and liposomes. An interaction between IL-2 and components of fetal calf serum is also demonstrated. The results indicate that liposomes may interfere with IL-2 bioassay but also show the possibility of potentiating IL-2 activity for therapeutic purposes.

[Kinds of home accidents]

A survey on hospitalization due to domestic accidents conducted in Padua in three public hospitals shows that between 1979 and 1988 there were 12.251 cases. Women in particular seemed to be affected by the phenomenon (7.926 cases, 64.7% of total) especially if aged 45 years or over (6.382 hospitalizations). Home injuries among females are the second cause of hospitalization due to trauma and represent the leading cause of accidental deaths (355 cases during the period of the survey). Lethality of this kind of injury progressively increases starting from the ages 30-44, and reaches 7.1% in older people (60 years or over). The causes of these accidents have been analyzed in 197 cases of fatal domestic accidents during the five years 1984 to 1988 and in 277 cases of non fatal accidents that involved subjects between the ages of 15 and 59 during the years 1986. In both situations the most frequent cause was falling (132 fatal, 159 non fatal cases); this finding shows the importance of a primary prevention programme based on the improvement of domestic structures and more care in furniture planning. The second place both among fatal and non fatal injuries belongs to burns (21 fatal and 17 non fatal). These frequently arise from incorrect behavior and emphasize in this way the necessity of improving sanitary education. A great number of home accidents (33 hospitalizations), can be attributed to bad working instruments or absence of security devices. This all shows the necessity of specific security regulations regarding installations and utensils of domestic use.

Hyperbaric and transcorneal delivery of oxygen to the rabbit and monkey anterior segment

When delivered to the corneal surface of rabbits for 30 minutes, 100% oxygen can significantly increase the mean (+/- SD) partial pressure of oxygen (PO2) in the aqueous humor (from 63.5 +/- 12.3 mm Hg [n = 12] to 139.5 +/- 32.4 mm Hg [n = 8]). Similar elevations were seen in monkeys. Under hyperbaric conditions (2 atm) for 30 minutes the aqueous PO2 in rabbits breathing room air can be increased to 295.2 +/- 132.4 mm Hg (n = 7) by exposing the rabbit cornea to 100% oxygen for 30 minutes. The high PO2 under these hyperbaric conditions is mediated by both vascular and transcorneal delivery of oxygen. The increase of PO2 in the rabbit aqueous can prevent or reverse sickling of intracameral human erythrocytes containing sickle hemoglobin. The exposure of rabbit eyes to 100% oxygen at the corneal surface is followed by autoregulation (constriction) of the iris vasculature. Transcorneal or vascular delivery of oxygen to the eye under normobaric or hyperbaric conditions may possibly benefit patients with hypoxic diseases of the anterior segment such as anterior segment necrosis, rubeosis iridis, or sickle cell hyphema.

Diagnostic cytology in breast cancer screening

In the period 1977-1978, 245 solid or cystic breast tumors and 134 nipple secretions were evaluated cytologically at the Trieste Cancer Institute. The results are discussed in the light of literature reports, and the high incidence of unsatisfactory smears observed in the group of malignant lesions (14,7%) is attributed to incorrect technique in specimen collection. The incidence of false positives and false negatives was 0,2% and 2,9%, respectively. The data reported are insufficient for significant statistical conclusion, but nevertheless confirm further the diagnostic importance of breast cytology whose routine practice in patient study protocols for breast cancer is highly recommended.