[Expression of cancer testis (CT) antigens in pediatric and adolescent melanomas]

BACKGROUND

One of the main problems in the diagnostics of pediatric melanomas is the differentiation from benign dermal lesions typical for this age group, such as Spitz nevus. The biological behavior of pediatric melanomas differs considerably from that of melanomas in adults.

MATERIAL AND METHODS

Cancer testis (CT) antigens are named after their typical expression pattern since they are present in various types of malignant tumors but in normal adult tissues are solely expressed in testicular germ cells. Because of this tumor-associated expression pattern, CT antigens are regarded as potential targets for vaccine-based immunotherapy of cancer and might be used as diagnostic tools in surgical pathology. In adults, melanoma is among the tumors showing a high incidence of CT antigen expression; however, while there is ample knowledge about adult melanomas, little is known about the presence of CT antigens in pediatric melanomas. Consequently, the expression of CT antigens MAGE-A1, MAGE-A4, CT7/MAGE-C1, NY-ESO-1, and GAGE was analyzed in a series of pediatric melanomas. The study was restricted to cases of metastatic disease and/or fatal outcome. A total of 12 cases were available and immunohistochemically analyzed with monoclonal antibodies (mAb).

RESULTS

The expression of CT antigens was generally low and present in only 4 of 12 cases. This is in stark contrast to the expression of these antigens in adult melanomas. Moreover, the extent of expression was very limited with most cases showing only a focal CT antigen expression and only marked in very small tumor areas (<5%).

CONCLUSION

Despite the low case numbers this study indicates that CT antigens are most likely not useful as diagnostic markers in pediatric melanomas or as targets for vaccine-based immunotherapy. It supports the notion that pediatric melanomas show a different biological behavior than their adult counterparts.

[Evaluation of occupational exposure to biological agents, endotoxins and PNOC in a sewage treatment plant]

The aim of this work has been to determine the occupational exposure to the biological agents and airborne dust in a sewage treatment plant in south Italy. The air samplings were performed in a sewage treatment plant in Calabria, in two different seasons (spring and summer) at 5 sites associated with various phases of sewage treatment process. In addition we have estimated the concentration of airborne endotoxins and PNOC (Particles Not Otherwise Classified) by using personal samplers. The results showed a significant variation in exposure to bioaerosols, endotoxins and PNOC depending on the sampling season: the PNOC concentration increase as much as the endotoxins concentration in spring and decrease in summer

Follow up study on the immune response to low frequency electromagnetic fields in men and women working in a museum

Seven women and eight men, exposed to low frequency (50 Hz) electromagnetic fields (EMFs) in a museum for 20 hours a week, were investigated in the years 1999 and 2005. During the first study, the mean EMF exposure in the working place was 1.7 microT and 1.1 microT, respectively. In the first investigation, the EMF-exposed men showed reduced blood NK lymphocytes in relation to controls, while EMF-exposed women presented reduced PHA-stimulated IFN-gamma release from peripheral blood mononuclear cells (PBMC). In the year 2005, blood cytotoxic activity, state and trait anxiety (STAI I and II, respectively) and occupational stress were also investigated. The scores of STAI I and II of the control women were slightly higher than those of the control men. EMF-exposed men showed higher occupational stress but normal immune parameters. EMF-exposed women showed, in relation to controls, lower PHA-stimulated IFN-gamma release from PBMC and reduced blood cytotoxic activity/CD45+-CD16+-56+ NK lymphocytes (but not per ml of blood). One of the women exposed to EMF, who worked a night shift, showed marked lymphopenia with very low NK lymphocytes and reduced IFN-gamma release; these immune parameters returned to normal following a change of work site. This study suggests that low frequency EMFs affect the immune functions of women more than those of men. Moreover, the determination of immune parameters seems to be a useful marker of the health effects of exposure to EMFs.

The immune response of women with prolonged exposure to electromagnetic fields produced by radiotelevision broadcasting stations

Twelve women, five of them housewives, exposed in their residences to electromagnetic fields (EMFs)emitted by radio-television broadcasting stations for a mean period of 13 years, were investigated. The EMFs in the balconies of the homes were (mean + S.D.) 4.3 + 1.4 V/m in the year 2000 and 3.7 + 1.3 V/m in 2005, while the exposure in the nearby area was <2.0 V/m. The EMF exposed women showed in 2000 reduced blood NK lymphocytes as well as PHA stimulated PBMC proliferation and IL-2 and IFN-gamma release. In the year 2005, the EMF exposed women and 48 control women with similar ages(mean 43 years), smoking habits, atopy and social level were investigated. State (temporary) and trait(tendency of the personality) anxiety were determined by STAI I and II, respectively. Blood cytotoxic activity and lymphocyte subsets were also determined. The ratio STAI I/STAI II of the EMF exposed group was lower than that of the control group. The blood cytotoxic activity of the exposed women was lower (p<0.01), percent of B CD45+-CD19+ lymphocytes higher and percent of CD45+-CD3+-CD8+ cells lower (p<0.05). Moreover, cytotoxic activity/CD45+-CD16+-56+ NK lymphocytes of the controls was negatively correlated with STAI I and STAI II (p<0.001). In conclusion, this study demonstrates reduced blood cytotoxic activity and increased trait anxiety in relation to state anxiety in EMF exposed women. An effect of EMFs on immune functions, in part mediated by nervous mechanisms, may be hypothesized. However, the influence of lifestyle may not be excluded.

Bone marrow mesenchymal stromal cells (BM-MSCs) from healthy donors and auto-immune disease patients reduce the proliferation of autologous- and allogeneic-stimulated lymphocytes in vitro

OBJECTIVES

To investigate the ability of bone marrow (BM)-derived mesenchymal stromal cells (BM-MSCs) in suppressing the proliferation of stimulated lymphocytes across a range of conditions including autologous BM-MSCs derived from autoimmune disease (AD) patients.

METHODS

In vitro cultures of BM-MSCs from healthy donors and AD patients were established and characterized by their differentiation potential into adipocytes and osteoblasts, and their fibroblast-colony-forming unit (CFU-F) ability and phenotype by flow cytometry. BM-MSCs (irradiated and non-irradiated) from healthy and AD patients were tested for their ability to suppress the in vitro proliferation of autologous and allogeneic peripheral blood mononuclear cells (PBMC) (from healthy donors and patients suffering from various ADs) stimulated with anti-CD3epsilon antibody alone or in combination with anti-CD28 antibody. The anti-proliferative effect of the BM-MSCs from healthy donors was tested also on transformed B-cell lines as a model of non-antigen-stimulated lymphocytes.

RESULTS

BM-MSCs from healthy donors and AD patients reduced the proliferation of autologous and allogeneic PBMCs by up to 90% in a cell dose-dependent fashion. The immunosuppression was independent of the proliferation of the BM-MSCs and was also effective on already proliferating cells. It was independent also of the clinical activity of AD. An MSC dose-dependent pattern of suppression of proliferation was observed also with transformed B-cell lines, similar to that observed with proliferating PBMC.

CONCLUSIONS

The BM-MSCs exhibit extensive anti-proliferative properties against lymphocytes under different conditions. This property might offer a form of immunomodulatory cellular therapy for AD patients if further confirmed in animal models.

[Mount Reventino greenstone: assessment of tremolite fibre dispersion in the workplace]

BACKGROUND

Mount Reventino, a massif located in the Calabria Region of Italy, has several ophiolite outcrops of greenstone. These deposits are an important economical resource in the surrounding area. Some rock layers contain tremolite, a type of asbestos fibre.

OBJECTIVES

The aim of this paper was to analyze the chemical and physical structure of the outcrops of Mount Reventino, and to assess and reduce the risk to workers associated with exposure to airborne fibres.

METHODS

Personal and environmental samples were collected and analysed by Scanning Electron Microscopy equipped with energy-dispersive X-ray analysis.

RESULTS

The analysis of samples showed a difference in mineralogical features not only between the quarries under study, but also between the two opposite sides of the mountain. Exploitation of the quarries produces a fibre dispersion that is higher than the natural emission. Occupational exposure to asbestos fibres during greenstone transformation was confirmed by by the results of analysis of the collected samples.

CONCLUSIONS

This study made it possible to identify working activities with highest exposure to asbestos and establish the correct procedures to abate fibre dispersion, in order to reduce the correlated risk. Environmental samples collected in the urban area surrounding the quarries showed that the asbestos fibre concentrations were very low, however, further studies are needed in order to confirm these findings.

[Biological risk in the operating room: microbiological monitoring of the environment and analysis of the associated variables]

The authors present an environmental microbiological monitoring programme carried out over a period of 15 months in 16 operating theatres performing specific types of surgery. The levels of microbial contamination of the air and of four of the most representative surfaces of the clean area were determined at 3 different times for each theatre, both before and during surgery. For the air assessment, the results obtained with three different samplers, Sed-3 Unit, SAS and RCS, were compared. The results were on the whole acceptable, but some poor conditions were detected during the theatres in use, especially in general surgery theatres; in some of these the floors showed levels of contamination consistently exceeding the reference limits. As the monitoring programme proceeded, the microbiological quality of the air and of the surfaces in the theatres notably improved. The three air samplers showed different conditions expressed with units of measure not always readily comparable. For active samplers, the bacterial load determined by RCS, although less variable, were always higher (even 2-3 fold) than those obtained with the SAS. Passive sampling takes longer but determines the real risk of infection for the patients; contemporary determination of the fall-out and the CFU/m3 helps to identify the occupational risks. Since the limit values established by the ISPESL guidelines for the operating theatres have been defined only for active samplers, there is urgent need for more exhaustive national guidelines to define similar values also for passive sampling. The Authors conclude stressing the importance of promoting continuing information-education programmes to heighten the awareness of all those involved in operating theatre activities.

Phase I/II clinical trial of a nonreplicative vaccinia virus expressing multiple HLA-A0201-restricted tumor-associated epitopes and costimulatory molecules in metastatic melanoma patients

We performed a phase I/II clinical trial in metastatic melanoma patients with an ultraviolet (UV)-inactivated nonreplicating recombinant vaccinia virus enabling the expression, from a single construct, of endoplasmic reticulum-targeted HLA-A0201-restricted Melan-A/MART-1(27-35), gp100(280-288), and tyrosinase(1-9) epitopes, together with CD80 and CD86 costimulatory proteins. Corresponding soluble peptides were used to boost responses and granulocyte-macrophage colony-stimulating factor was used as systemic adjuvant. Safety and immunogenicity, as monitored with in vitro-restimulated peripheral blood mononuclear cells by cytotoxic T lymphocyte precursor (CTLp) frequency analysis and tetramer staining, were specifically addressed. Of 20 patients entering the protocol, 2 had to withdraw because of rapidly progressing disease. Immune responses were evaluated in 18 patients (stage III, n = 5; stage IV, n = 13) and increases in specific CTLp frequencies were observed in 15. In 16 patients responsiveness against all 3 antigens could be analyzed: 7 (43%), including all stage III cases, showed evidence of induction of CTLs specific for the three epitopes, and 2 (12%) and 4 (25%), respectively, showed reactivity against two or one tumor-associated antigen. In three stage IV patients no specific CTL reactivity could be induced. Increases in CTLp frequency were detected mostly after viral vaccine injections. However, in a majority of patients final CTLp levels were comparable to initial levels. Tetramer characterization of Melan-A/MART-1(27-35)-specific CTLs during the protocol also suggested preferential expansion after recombinant virus administration. Vector-specific humoral responses, frequently undetectable in stage IV patients, did not appear to prevent tumor-associated antigen-specific CTL induction. Aside from a single occurrence of transient grade 3 leukopenia, no major clinical toxicity was reported. Seventeen of 18 patients completed the 3-month trial (one patient died before the last delayed-type hypersensitivity test). Three displayed regression of individual metastases, seven had stable disease, and progressive disease was observed in seven patients. This is the first report on the administration of a UV-inactivated recombinant vaccinia virus coexpressing five transgenes in cancer patients. The results described here, in terms of safety and immunogenicity, support the use of this reagent in active specific immunotherapy.

Pesticides re-entry dermal exposure of workers in greenhouses

This research has the aim to evaluate the risk of pesticide dermal exposure for workers in greenhouses. We considered the following crops: tomato, cucumber and strawberry, largely spread in Bracciano lake district. The pesticides monitored were: tetradifon on strawberry: metalaxyl, azoxystrobin and fenarimol on cucumber; acrinathrin, azoxystrobin and chlorpyrifos ethyl on tomato. The dermal exposure was evaluated by Dislodgeable Foliar Residue (DFR) measurements employing transfer coefficients got from literature. For risk evaluation, we have compared the dermal exposures with Acceptable Operator Exposure Levels (AOEL). The re-entry time were obtained intercepting the dose decay curves with AOEL values. The re-entry times result higher than two days in the cases of chlorpyrifos on tomato (re-entry time: 3 days), azoxystrobin on tomato (4 days), and tetradifon on strawberry (8 days). The need of measuring specific transfer coefficients is pointed out.

[Preventive measures suggested to protect health workers from the risk due to a potential exposure to SARS agents]

The Authors describe the personal and environmental preventive measures suggested to protect health workers from the risks due to a potential exposure to SARS agents. The Authors stress the need that workers are allowed to wear individual protective disposable complying with technical regulations in order to be assured the best protection.

Cell fusion: an approach to generating constitutively proliferating human tumor antigen-presenting cells

Somatic cell hybrids of HLA-A2(+) EBV-transformed B- or dendritic cells (DC) and allogeneic HLA-A2(-) melanoma cell line Me15 were obtained by in vitro electrofusion using an electroporator. Before fusion, melanoma cells were stably transfected with green fluorescent marker protein (GFP) and neomycin resistance gene (neo(+)). Stably growing hybrid antigen-presenting cells (HAPC) expressing HLA-DR and HLA-A2 (or HLA-A30/31), and melanoma-associated antigens (MART-1, gp100) were selected by a double strategy of immunomagnetic MACS and neomycin selection. Fusion efficiency ranged between 3% and 18% (mean: 8.0+/-4.7%) as defined by simultaneous GFP and HLA-A2 detection. Expression of melanoma-associated antigens (MART-1, gp100) in hybrid cells was determined by reverse transcription-polymerase chain reaction (RT-PCR). HLA-restricted antigen-specific presentation of melanoma antigens was demonstrated by killing of semi-allogenic HAPC by HLA-A2-restricted MART-1 or gp100-specific cytotoxic T lymphocyte (CTL) clones. HLA restriction and antigen specificity were confirmed by inhibition of specific cytotoxicity by anti-HLA antibodies and cold target inhibition. During long-term (42-70 days) neomycin selection of HAPC, a drastic loss of antigen-presenting cell (APC)-derived determinants (e.g. HLA-DR, HLA-A2) was observed which, however, could be "reversed" by repeated MACSorting (days 10, 21 and 49). Our method allows the generation of semi-allogenic HAPC that constitutively proliferate in vitro. This opens the possibility of establishing a number of tumor-APC hybrids expressing defined HLA haplotypes and tumor antigens, of investigating their specific properties (e.g. antigen processing), and testing their diagnostic or therapeutic potential.

B-lymphocytes from malignant hyperthermia-susceptible patients have an increased sensitivity to skeletal muscle ryanodine receptor activators

Malignant hyperthermia (MH) is a pharmacogenetic disease triggered by volatile anesthetics and succinylcholine in genetically predisposed individuals. The underlying feature of MH is a hypersensitivity of the calcium release machinery of the sarcoplasmic reticulum, and in many cases this is a result of point mutations in the skeletal muscle ryanodine receptor calcium release channel (RYR1). RYR1 is mainly expressed in skeletal muscle, but a recent report demonstrated the existence of this isoform in human B-lymphocytes. As B-cells can produce a number of cytokines, including endogenous pyrogens, we investigated whether some of the symptoms seen during MH could be related to the involvement of the immune system. Our results show that (i) Epstein-Barr virus-immortalized B-cells from MH-susceptible individuals carrying the V2168M RYR1 gene mutation were more sensitive to the RYR activator 4-chloro-m-cresol and (ii) their peripheral blood leukocytes produce more interleukin (IL)-1beta after treatment with the RYR activators caffeine and 4-chloro-m-cresol, compared with cells from healthy controls. Our result demonstrate that RYR1-mediated calcium signaling is involved in release of IL-1beta from B-lymphocytes and suggest that some of the symptoms seen during an MH episode may be due to IL-1beta production.

Attitudes and behavior of young European adults towards the donation of organs--a call for better information

Public perception of organ donation critically affects the availability of organ transplantation in the Western world. To assess the attitude of young adults towards the donation of organs and to investigate potential factors influencing their knowledge and actual behavior regarding organ transplantation, we evaluated a handout questionnaire survey of all Swiss-Italian recruits during six of the years 1989-98 (n = 7272). The attitude of recruits towards organ donation did not change significantly within the 10-year survey period: 61% of young men would personally donate their organs in the case of brain death, 13% would refuse, and 26% had not made up their mind. If they had to decide for close relatives, 50% would consent; 60% of recruits neither knew their next of kin's attitude nor had informed them about their own opinion; 80% felt they were insufficiently informed about organ transplantation. A significantly more positive attitude towards organ donation was found among men who felt they were sufficiently informed, who had close next of kin who were aware of their personal attitude (p < 0.0001), who had contacts with transplanted persons (p < 0.015), or who believed in an existence after death (p < 0.001; chi2-test). Our results suggest that there is potentially large support towards organ donation in this population. To minimize the high rate of indecisiveness, young adults need more appropriate information on the subject and they ask for it.

Functional outcome of transplanted knee joints in dogs

Total knee joint transplantation has been performed in animal models and humans. This study investigates the impact of this operation on knee joint function in a dog model. Therefore, replantation was compared to transplantation during a 6-month follow-up period in four dogs in each group. The peak vertical ground reaction force normalized in all legs undergoing replantation and in two of four after transplantation. A third transplant recipient reduced loading from the 4th month due to a local complication, and the fourth succumbed to sepsis 3 months postoperatively. A weight-bearing index (WBI), defined as loading of the grafted divided by loading of both hind-limbs decreased from 0.48 +/- 0.08 preoperatively to 0.13 +/- 0.10 by 1 month after replantation and from 0.53 +/- 0.07 to 0 after transplantation. After 6 months, weight-bearing of all replant recipients was restored, but reduced in two transplant recipients with graft function. Full recovery after replantation, but impaired function after transplantation, was also reflected in the histological results: normal histological pictures of blood vessels, cartilage, bone and soft tissues were found in all replant recipients, but infiltrative vasculopathy indicating chronic rejection was found in the transplanted joints. The results of this animal study confirm that the procedure can lead to satisfactory functional results but also emphasize the need for perfect control of immunosuppression.

Quantitative analysis of gene expression in human articular cartilage from normal and osteoarthritic joints

OBJECTIVE

To quantify the expression of genes encoding extracellular matrix (ECM) proteins in human cartilage from normal and osteoarthritic (OA) joints.

DESIGN

Human cartilage samples were classified as control (CTR) or OA according to clinical evaluation and assessed histologically and biochemically to confirm the diagnosis. mRNAs encoding collagen types I, II and X, aggrecan, versican, osteopontin and osteocalcin were quantified by real-time reverse transcription-PCR assays and normalized to a reference mRNA (GAPDH).

RESULTS

RNA from native cartilage could be reproducibly and efficiently amplified by real-time PCR only if isolated using purification membranes. Primers and fluorescent probes for real-time PCR, endowed with comparable (<6% difference from GAPDH) and high (>91%) amplification efficiencies, were designed and validated for the selected ECM genes. The expression of most genes under investigation displayed large variations and was not significantly different in CTR and OA cartilage. Only osteopontin mRNA levels were significantly higher in OA than CTR specimens. mRNA ratios of collagen type II to I and of aggrecan to versican, defined as indexes of chondrocyte differentiation, were less variable within each population than the single genes and markedly higher (27.0 and 7.6-fold, respectively) in CTR than OA cartilage, with high statistical significance (P = 0.00013 and P = 0.00007, respectively).

CONCLUSIONS

Our results provide evidence that gene patterns related to chondrocyte differentiation discriminate between CTR and OA human cartilage with higher sensitivity than single ECM genes. The method described here has the potential to improve understanding of the progression of OA and could become a valuable diagnostic tool.

Efficient simultaneous presentation of NY-ESO-1/LAGE-1 primary and nonprimary open reading frame-derived CTL epitopes in melanoma

Recent studies have shown that CTL epitopes derived from tumor-associated Ags can be encoded by both primary and nonprimary open reading frames (ORF). In this study we have analyzed the HLA-A2-restricted CD8(+) T cell response to a recently identified CTL epitope derived from an alternative ORF product of gene LAGE-1 (named CAMEL), and the highly homologous gene NY-ESO-1 in melanoma patients. Using MHC/peptide tetramers we detected CAMEL(1-11)-specific CD8(+) T cells in peptide-stimulated PBMC as well as among tumor-infiltrated lymph node cells from several patients. Sorting and expansion of tetramer(+) CD8(+) T cells allowed the isolation of tetramer(bright) and tetramer(dull) populations that specifically recognized the peptide Ag with high and low avidity, respectively. Remarkably, only high avidity CAMEL-specific CTL were able to recognize Ag-expressing tumor cells. A large series of HLA-A2-positive melanoma cell lines was characterized for the expression of LAGE-1 and NY-ESO-1 mRNA and protein and tested for recognition by CAMEL-specific CTL as well as CTL that recognize a peptide (NY-ESO-1(157-165)) encoded by the primary ORF products of the LAGE-1 and NY-ESO-1 genes. This analysis revealed that tumor-associated CD8(+) T cell epitopes are simultaneously and efficiently generated from both primary and nonprimary ORF products of LAGE-1 and NY-ESO-1 genes and, importantly, that this occurs in the majority of melanoma tumors. These findings underscore the in vivo immunological relevance of CTL epitopes derived from nonprimary ORF products and support their use as candidate vaccines for inducing tumor specific cell-mediated immunity against cancer.

Augmentation mammaplasty with a new cohesive gel prosthesis

We present our experience with augmentation mammaplasty on 14 patients with a thin chest wall and poor subcutaneous tissue. Thanks to Polytech Silimed code 20675, a new anatomical prosthesis filled with "soft" cohesive gel, the lodging in a subglandular position was possible without anomalous salience in the upper pole, and a more natural mammary profile was achieved without capsular contracture, dislocation, or misplacement of the mammary implants.

Melanoma cells present a MAGE-3 epitope to CD4(+) cytotoxic T cells in association with histocompatibility leukocyte antigen DR11

In this study we used TEPITOPE, a new epitope prediction software, to identify sequence segments on the MAGE-3 protein with promiscuous binding to histocompatibility leukocyte antigen (HLA)-DR molecules. Synthetic peptides corresponding to the identified sequences were synthesized and used to propagate CD4(+) T cells from the blood of a healthy donor. CD4(+) T cells strongly recognized MAGE-3281-295 and, to a lesser extent, MAGE-3141-155 and MAGE-3146-160. Moreover, CD4(+) T cells proliferated in the presence of recombinant MAGE-3 after processing and presentation by autologous antigen presenting cells, demonstrating that the MAGE-3 epitopes recognized are naturally processed. CD4(+) T cells, mostly of the T helper 1 type, showed specific lytic activity against HLA-DR11/MAGE-3-positive melanoma cells. Cold target inhibition experiments demonstrated indeed that the CD4(+) T cells recognized MAGE-3281-295 in association with HLA-DR11 on melanoma cells. This is the first evidence that a tumor-specific shared antigen forms CD4(+) T cell epitopes. Furthermore, we validated the use of algorithms for the prediction of promiscuous CD4(+) T cell epitopes, thus opening the possibility of wide application to other tumor-associated antigens. These results have direct implications for cancer immunotherapy in the design of peptide-based vaccines with tumor-specific CD4(+) T cell epitopes.

Trauma decreases leucine enkephalin hydrolysis in human plasma

Plasma hydrolysis of leucine enkephalin was evaluated, together with several cellular immune parameters, in a homogeneous group of human subjects who had undergone severe trauma (proximal femur fracture); data obtained were compared with those obtained in an age-matched control group. In the experimental group, immediately after hospitalization, substrate hydrolysis was reduced with respect both to the control subjects and the same patients 4 weeks after the trauma. Chromatographic separation of the enzymes active on leu-enkephalin showed that the reduction of substrate hydrolysis is mainly attributable to the decrease in the activity of enkephalin-degrading enzymes, principally of aminopeptidases, per se, whereas the role of the low-molecular-weight plasma inhibitors is only minor. In the same subjects, several of the immunological parameters measured underwent modifications that may be considered stress related. However, the absence of a quantitative relationship between reduction in hydrolysis and modifications of immune parameters does not support the hypothesis of a direct relationship between these two sets of data.

Age increases leucine enkephalin hydrolysis in human plasma

BACKGROUND

The existence of age-associated alterations in immune functions and neuropeptides capable of modulating these functions prompted us to advance the hypothesis that the degradation of plasma neuropeptides, specifically opioid peptides, may be altered by aging.

OBJECTIVE

To verify the possible existence of age-induced variations in neuropeptide hydrolysis in human plasma, using leucine enkephalin as the model substrate.

METHODS

The hydrolysis of leucine enkephalin and the formation of its hydrolysis byproducts in the presence of plasma enzymes were studied by kinetic and chromatographic techniques in a group of elderly individuals and a control group.

RESULTS

The results obtained indicate that in elderly individuals the activity of enkephalin-degrading plasma enzymes is greater than in controls. ANOVA analysis of these data indicates that the dependency of the variation of hydrolysis upon the 2 age groups is statistically significant. Increased substrate hydrolysis, and a modified hydrolysis pattern, appear to be associated with increased activity of the enzymes involved, and with different distribution of the individual enzymes within each class, as well as with severely reduced activity of the low molecular weight plasma inhibitors.

CONCLUSION

The combination of the above-mentioned factors appears to define a characteristic hydrolysis pattern for elderly individuals which is different from that found in controls.

Age-induced increase of leucine enkephalin enzyme degradation in human plasma

Possible age-induced variations of the hydrolysis of leucine enkephalin in the presence of plasma enzymes were studied by kinetic and chromatographic techniques in a group of elderly individuals. Results obtained indicate that in elderly individuals the activity of enkephalin-degrading plasma enzymes is greater than in the controls; ANOVA analysis of these data indicates that the dependency of the variation of hydrolysis upon the two age groups is statistically significant. Increased substrate hydrolysis, and a modified hydrolysis pattern, appear to be associated with increased activity of the enzymes involved, and with different distribution of the individual enzymes within each class, as well as with severely reduced activity of the low molecular weight plasma inhibitors. The combination of these factors defines a characteristic hydrolysis pattern for the elderly individuals, different from that found in the controls.

Immunohistochemical detection of MAGE tumor-associated antigens in esophageal squamous cell carcinoma

Genes of the MAGE family encode tumor-specific antigens recognized by cytotoxic T-lymphocytes in a variety of neoplasms. We investigated the protein expression of these antigens as related to the gene expression, in esophageal squamous cell carcinoma by using monoclonal antibodies recognizing MAGE gene products. Esophageal squamous cell carcinomas were found to express both MAGE-1 (4 out of 15 samples) and MAGE-3 (7 out of 15 samples) genes, by RT-PCR. Immunoblotting revealed MAGE-1 and MAGE-3 gene products in 2 and 6 out of 15 samples, respectively. Immunohistochemistry performed on 12 samples showed MAGE-1 protein expression, limited to single tumor cells, in 2 cases. MAGE-3 gene product was detectable in 7 cases: in 5 of them over 50% of neoplastic cells were positive. Considering the high percentages of tumor cells expressing MAGE-3 antigen, the use of epitope-based vaccines could be envisaged in patients displaying appropriate HLA-class I phenotype.

Nonreplicating recombinant vaccinia virus encoding human B-7 molecules elicits effective costimulation of naive and memory CD4+ T lymphocytes in vitro

We constructed recombinant vaccinia viruses (recVV) encoding the human T-cell costimulatory molecules B7-1 and B7-2. To abrogate the vaccinia virus transcription termination signal for early genes, the cDNA of B7-1 had to be modified by a T through C sense mutation at position 766. Upon infection with replication incompetent and noncytopathic recVV, several tumor cell lines as well as cultured human fibroblasts expressed the costimulatory molecules. All these cells were capable of providing effective costimulation for proliferation of resting CD4(+) T-cells after infection with recVV encoding B7 molecules. The costimulatory effect could be blocked with CTLA-4 IgG fusion protein, the soluble ligand for B7. RecVV-induced overexpression of B7 on syngeneic EBV-transformed lymphoblastoid B-cells was able to costimulate the proliferative response of CD4(+) memory cells against VV antigens. The possibility of easily engineering a variety of human cells using recVV encoding human B7 molecules holds implications for the future design of vaccination strategies.

Functional and morphological outcome of knee joint transplantation in dogs depends on control of rejection

BACKGROUND

The reconstruction of massive osteochondral defects extending to weight-bearing joints remains a surgical challenge. Total knee joint transplantation has been performed experimentally, but these studies lacked prospective evaluation of functional outcome, graft vascularization, and graft viability.

METHODS

Replantation and transplantation of vascularized knee joints was performed in dogs (n=4 per group), comparing functional and morphological results during a 6-month follow-up.

RESULTS

All replant recipients and three transplant recipients survived the 6-month follow-up period. At this time, duplex sonography and angiography revealed patent anastomoses in all animals. Increases in volumetric flow rates and vascular collateralization were observed in allografts, as compared with replanted joints (100+/-16 ml/min vs. 31+/-15 ml/min at 6 months after transplantation). Bone fusion at the graft-host interface was verified by fluorography in all animals at 3 months after transplantation. Six months after transplantation, microradiographies and computerized tomographies revealed spongialization of the cortical bone and filling of the medullary space by trabecular bone in transplanted joints. Such alterations were not detectable in replanted joints. Chondrocyte viability exceeded 80% in all but one transplanted joint. Lymphocyte infiltration of synovia and arterial walls was detected in all transplanted joints, suggesting the presence of chronic rejection. Weight-bearing capacity recovered in all replanted animals (weight-bearing index before transplantation: 0.499+/-0.080; 6 months after transplantation: 0.38+/-0.16) but only in two of four transplanted animals (weight-bearing index 6 months after transplantation: 0.37, 0.28, and 0.00).

CONCLUSIONS

These data demonstrate the potential of joint grafting and the critical dependence of allotransplantation on the control of rejection.

The tumour-associated antigen MAGE-1 is detectable in formalin-fixed paraffin sections of malignant melanoma

The MAGE-1 gene encodes a protein encompassing a HLA-A1-restricted target epitope for cytolytic T lymphocytes. Monoclonal antibodies directed against the MAGE-1 protein were tested for usage in immunohistology of routine pathology material. Seven formalin-fixed, paraffin-embedded malignant melanomas were studied by the Avidin-Biotin complex (ABC) method with or without different antigen retrieval methods. Native, frozen tissues from the same tumours were used to validate the results by immunohistochemistry on frozen sections, by PCR for mRNA and by protein demonstration in tissue extracts using western blotting. Of 4 monoclonal antibodies tested, mAB 34B and mAB 77B were highly efficient in detecting MAGE-1 protein in deparaffinised sections with the regular ABC method after microwave pretreatment. In a series of an additional 28 patients 75% expressed MAGE-1, 50% in a substantial proportion. Follow-up studies in 6 patients indicate that the expression pattern remains stable but may change substantially within a short range. Immunohistology is thus a rapid and well-established method that might be used to select and monitor HLA-A1 positive patients with malignant melanoma and other candidate tumours for MAGE-1-directed immuno-therapy.

Monoclonal antibodies against recombinant-MAGE-1 protein identify a cross-reacting 72-kDa antigen which is co-expressed with MAGE-1 protein in melanoma cells

The MAGE-1 gene codes for tumor-associated peptides recognized by cytolytic T lymphocytes in association with MHC-class-1 molecules such as HLA-A1 and HLA-Cw16. In the course of a study aiming at the immunohistochemical detection of the MAGE-1 gene product in tumor samples, 2 mouse monoclonal antibodies (MAbs) directed against a full-length recombinant MAGE-1 fusion protein were found to react strongly not only with the 46-kDa MAGE-1 protein, but also with a 72-kDa product in immunoblots of lysates obtained from several MAGE-1-mRNA-positive melanoma cell lines. Pre-incubation of the antibodies with the recombinant MAGE-1 fusion protein abolished their reactivity both with MAGE-1 protein and with the 72-kDa product, thus confirming the occurrence of antigenic determinant(s) shared by the 2 proteins. The 72-kDa protein is not an alternative product of MAGE-1, since it was still detected in lysates of a MAGE-1 loss variant derived from a MAGE-1-positive melanoma cell line. Moreover, the 72-kDa protein does not appear to be a product of the other members of the MAGE gene family known to be expressed in tumors (such as MAGE-2, -3, -4 and -12). Interestingly, expression of the 72-kDa protein was found to be correlated with that of MAGE-1 protein. Thus, in 30 tumor cell lines analyzed by immunoblotting and RT-PCR, the 72-kDa protein was never detected in MAGE-1-mRNA-negative cell lines, while it was co-expressed with MAGE-1 protein in 12 out of 15 cell lines expressing MAGE-1. Furthermore, the 72-kDa protein was detected in lysates of human testis, the only normal tissue known to express MAGE-1. Finally, treatment of MAGE-1-mRNA-negative cell lines with 5-Aza-2'-deoxycytidine, a hypomethylating agent known to induce MAGE-1 expression, resulted in the expression of the 72-kDa protein. Taken collectively, these findings suggest that expression of the gene encoding the 72-kDa protein identified in this study through antigenic determinant(s) shared with MAGE-1 protein is regulated in a way similar to that of MAGE-1.

Effects of verapamil on skeletal muscle function following ischemia and reperfusion

Verapamil (VRP) improves ischemic tolerance of different organs including brain, kidney, liver and heart. We report here on the effects of preischemic VRP treatment on skeletal muscle function following 3 h of tourniquet ischemia and 2 h of reperfusion using a rodent model. Postischemic and contralateral limbs were evaluated. Fast (musculi peronei)- and slow-twitch muscles (musculus soleus) of both limbs were excised and electrically stimulated in vitro. VRP pretreatment was found to significantly decrease tetanic peak tension of both contralateral nonischemic m. soleus and mm. peronei. Furthermore, VRP improved fatigability of slow-twitch muscles of both ischemic and contralateral limbs [increase of fatigue index from 0.04 +/- 0.009 (0 mg/kg) to 0.10 +/- 0.019 (4 mg/kg)], but not of fast-twitch muscles. These data indicate that the effects of VRP on postischemic skeletal muscle function depend on fiber composition.

On the suitability of urethane bonds between the carrier and the drug moiety in poly(ethyleneglycol)-based oligomeric prodrugs

Some poly(ethyleneglycol) derivatives of propranolol were prepared, in which the drug molecule was linked to the oligomeric carrier via urethane bonds in order to study the suitability of this bond as a linkage between the carrier and the drug moiety in oligomeric prodrugs. For comparison purposes also ethanol- and butanol-based prodrugs of propranolol were prepared, with the same linkage between drug and promoiety. The urethane compounds were obtained by condensation via N,N'-carbonyldiimidazole. None of these compounds gave rise to appreciable blood concentrations of propranolol after oral administration, thus suggesting in this particular case, a relative in vivo resistance of urethane bonds towards cleavage.

[Tumor-immune system interaction in renal cell carcinoma and melanomas. Cytokine transcription in tumors at the time of surgical resection]

Tumor infiltrating lymphocytes (TIL) of many tumors express surface activation markers. An antigen driven stimulation of T-lymphocytes is expected to induce not only cell membrane activation molecules but also a unique pattern of cytokine gene transcripts. These cytokines are relevant modulators and potent effectors of immune responses, and therefore play a crucial role in tumor-immune system interaction. The gene transcription of interleukin(IL)-2, IL-4, IL-7, IL-10 and interferon(IFN)-gamma of lymphocyte infiltrated, freshly excised tumor specimens from 10 renal cell carcinomas and 6 melanomas were investigated by reverse polymerase chain reaction (PCR) technique. Autologous, peripheral mononuclear cells (PBMC) and healthy tissue of the affected organs served as controls. In all samples the transcription of the beta-actin gene as a methodological control turned out to be positive. In contrast, no cytokine gene transcription was detected in healthy tissue specimens and PBMC. IL-2 transcripts were detectable in no melanomas but in half of the renal tumor samples. IL-10 never transcribed in melanomas but was positive in 7 out of 10 renal cell carcinomas. In only 2 respectively 1 of the resected tissue probes was transcription of IL-4 and IFN-gamma detected. IL-7 was positive in 1 melanoma and in 6 urological neoplasias. The most impressive fact is the frequent transcription of the inhibiting factor IL-10 in renal cell carcinomas (7/10). This pattern of cytokine gene transcription may explain functional deficits of TIL.(ABSTRACT TRUNCATED AT 250 WORDS)

T-helper- and accessory-cell-independent cytotoxic responses to human tumor cells transfected with a B7 retroviral vector

As a means to increase the immunogenicity of tumor cells, we have developed a retroviral vector to transfect human B7, a molecule capable of delivering co-stimulatory signals to T cells. Three different tumors, a melanoma, an ovarian carcinoma and a myelomonocytic leukemia, were transfected with high efficiency. When compared for their capacity to stimulate allogeneic T cells, B7+ but not B7- tumor cells were able to stimulate strong proliferative and cytotoxic responses. The effector CTL generated recognised B7+ and B7- cells as well as untransfected tumor cells, indicating that B7 is required in the inductive but not the effector phase of the response. Remarkably, B7+ tumor cells were able to induce cytotoxic responses both by CD4-depleted and by CD8-purified T cells, demonstrating that expression of B7 is at the same time necessary and sufficient to induce a cytotoxic response in the absence of T-helper cells and accessory cells.

CD14 and tolerance to lipopolysaccharide: biochemical and functional analysis

To evaluate the role of the high-affinity monocyte receptor for lipopolysaccharide (LPS), CD14, in the process of tolerance to LPS, the human monocytic cell line Mono-Mac-6 was cultured in the absence or presence of different amounts of LPS. The kinetics of CD14 modulation in these cells showed an initial 4-day period characterized by increased cell-surface expression, rate of biosynthesis (peaking at 48 hr) and release of its soluble forms (sCD14) which correlated with the amount of LPS in the culture. At this time, tolerance to LPS was already established, as measured by tumour necrosis factor-alpha (TNF-alpha) induction, it was LPS dose dependent and persisted up to 15 days. LPS also reduced the cell proliferation rate in a dose-dependent manner. After 8 days and up to 15 days, the CD14 biosynthesis, cell-surface expression and release of sCD14 inversely correlated with the level of LPS in the culture. The 48-hr LPS-pretreated cells showed a slightly decreased CD14 affinity for LPS, a relative high number of CD14 molecules per cells, and desensitization also to a phorbol 12-myristate 13-acetate (PMA) challenge. An anti-CD14 monoclonal antibody (mAb) protected the cells from tolerization when added at the beginning of culture, as revealed by challenge with LPS and PMA. The data indicate that in this model tolerization to LPS (1) precedes CD14 down-modulation, (2) operates by alteration of the receptor affinity for LPS and by a mechanism which affects a protein kinase C (PKC)-dependent signalling pathway, and (3) that CD14 plays a critical role in the establishment of tolerance to LPS. In addition, analysis of the data suggests the existence of a PKC-independent signalling pathway for LPS tolerization and a CD14-independent mechanism for establishing tolerance.

A soluble form of the human CD8 alpha chain expressed in the baculovirus system: biochemical characterization and binding to MHC class I

We have generated a soluble form of the CD8 molecule consisting of the entire extracellular domains of the human alpha chain, by expressing a mutated CD8 alpha cDNA in SF9 cells infected with a recombinant baculovirus. The truncated molecule was secreted into the medium mostly as a disulfide-linked homodimer in which a single cysteine residue in the hinge-like region (Cys143) was sufficient to assure covalent bonding. Soluble CD8 purified to homogeneity appears to be monodisperse as assessed by gel filtration analysis and contains only O-linked carbohydrates. To determine whether recombinant CD8 can interact with MHC class I molecules, we developed an assay that measures binding of MHC class I-bearing cell lines to purified CD8 adsorbed to plastic plates. The level of binding of cells to immobilized CD8 depended on the amount of CD8 bound to the plate and correlated with the levels of cell surface MHC class I expression. The binding was specifically inhibited by monoclonal antibodies directed either against CD8 or MHC class I molecules. This assay therefore provides a way to measure CD8 binding to MHC class I independently of other cell-cell interactions and should allow direct structure-function studies.

Poly(amidoamine)s with potential as drug carriers: degradation and cellular toxicity

Poly(amidoamine)s were synthesized by polyaddition reaction: to bis-acryloylpiperazine of piperazine (1), or N,N'-bis(2-hydroxyethyl)ethylenediamine (2), and to 2,2-bis(acrylamido)acetic acid of piperazine (3). Compound 2 was also end-capped with 4-hydroxythiophenol, thus introducing a terminal moiety suitable for radio-iodination using the chloramine T method (4). Such polymers behave as bases in aqueous solution, and their net average charge alters considerably as the pH changes from 7.4 to 5.5. This results in a change in polymer conformation which may prove useful in the design of polymeric drug delivery systems. However, their suitability for use in the organism will depend on polymer toxicity and also on their rate of biodegradation. Here we studied the biological properties of the above poly(amidoamine)s with a view to optimizing the synthesis of novel drug carriers. The general cytotoxicity of compounds 1, 2, 3, and 4 was examined in vitro using two human cell lines, hepatoma (HepG2) and a lymphoblastoid leukaemia (CCRF). Several different methods [the tetrazolium (MTT) test, [3H]leucine or [3H]thymidine incorporation, or counting cell numbers] were used to measure cell viability. Compounds 1, 2, and 4 were much less toxic to both cell lines than equivalent concentrations of the polycationic poly-L-lysine, and in no case did viability fall below 50% (concentrations up to 2 mg/ml). Although compound 2 was not markedly toxic to HepG2 cells, concentration-dependent toxicity was observed against CCRF cells. In this case, the polymer concentration decreasing viability by 59% (ID50) was approximately 50 micrograms/ml for compound 2 compared with an ID50 of approximately 10 micrograms/ml for poly-L-lysine. The rate of hydrolytic degradation of compound 2 was examined using viscometric measurements and gel permeation chromatography (GPC). After incubation at pH 7.5 and 8.0 for 24 h, polymer intrinsic viscosity was decreased by approximately 50% and GPC elution profiles showed a simultaneous increase in polymer retention time, indicating a fall in molecular weight. Hydrolytic degradation progressed much more slowly at pH 5.5. Compound 4 was also incubated with a mixture of isolated rat liver lysosomal enzymes (tritosomes) at pH 5.5, but no increase in the rate of degradation was observed.

Expression of the human V beta 8 gene product preferentially correlates with class II major histocompatibility complex restriction specificity

We report that, in peripheral blood T cells, the V beta 8 gene product is much more represented on CD4+CD8- than on CD4-CD8+ lymphocytes. This skewing was observed in all individuals tested and with two independent strategies, one of which allows the selection of V beta 8+ T cells independently from their major histocompatibility complex-antigen specificity. Our data imply that the human V beta 8 gene product confers class II restriction specificity and that both the T cell receptor chains and CD4 molecule are involved in the selection of the T cell repertoire.

CD3Ti+ human thymocyte-derived clones displaying a differential response to activation via CD3Ti and CD2

Previous studies indicated that, unlike peripheral T-cells, freshly isolated thymocytes show little or no proliferation to activation signals via either the antigen/MHC receptor complex (CD3Ti) or the CD2 structure, unless exogenous IL-2 or phorbol esters are added. To investigate these differences in more detail, we have studied the response of clonal populations of mature thymocyte subsets as well as peripheral T-cell clones to activation via either CD3Ti or CD2. Here we report the characterization of three clones belonging to different subsets of mature thymocytes: CD3+ CD4+ (Ti alpha/beta), CD3+ CD8+ (Ti alpha/beta), and CD3+ CD4- CD8- (Ti gamma/delta). All three clones could be induced to proliferate to insolubilized anti-CD3 mAb. In contrast, activating anti-CD2 mAbs, which induced proliferation in all peripheral T-cell clones tested, did not induce an appreciable proliferation of the thymocyte clones. The latter required additional signals provided by the phorbol ester PMA. However, anti-CD2 mAbs were able to induce early activation events such as phosphoinositide turnover and [Ca2+]i increase to an extent similar to the ones elicited by anti-CD3 mAb. These results further support previous findings suggesting that mature thymocytes are not functionally identical to peripheral T-cells.

Molecular cloning and expression of T11 cDNAs reveal a receptor-like structure on human T lymphocytes

The T11 (CD2) sheep-erythrocyte-binding protein is a T-cell surface molecule involved in activation of T lymphocytes and thymocytes, including those lacking the T3-Ti antigen-receptor complex. The primary structure of T11 was deduced from protein microsequencing and cDNA cloning. The mature human protein appears to be divided into three domains: a hydrophilic 185 amino acid external domain bearing only limited homology to the T-cell surface protein T4 and the immunoglobulin kappa light chain variable region, a 25 amino acid hydrophobic transmembrane segment, and a 126 amino acid cytoplasmic domain rich in prolines and basic residues. Transfection of cDNAs encoding either the 1.7- or the 1.3-kilobase T11 mRNA into COS-1 cells resulted in expression of surface T11 epitopes as well as sheep-erythrocyte-binding capacity. The predicted structure is consistent with the possibility that T11 functions in signal transduction.

[Separation of monocytes and their use in a cytotoxicity test]

Observations of acute rejections in uremic patients transplanted with Kidney grafts from Human Leucocyte Antigens (HLA) identical or compatible donors have suggested the importance of the role play by antigens not codified by the Major Histocompatibility Complex (MHC). Some works detected anti-monocytes antibodies that could not be absorbed with platelets (HLA-ABC) or with B lymphocytes (HLA-DR) or granulocytes but only with endothelial cells. Since endothelial cells and monocytes share not HLA surface determinants. Methods to isolate monocytes and endothelial cells have been attempted. We isolated monocytes by Percoll gradients. We checked the purity of our cell population by using monoclonal monocytes. From 30 ml of whole blood we obtained a mean of 50 X 10(6) (min. 12, 6 X 10(6) max 14 X 10(-6] mononuclear cells. After centrifugation of Percoll gradients we recovered a mean 7, 8 X 10(6) cells (Low 1, 3 X 10(6); max. 15 X 10(6] in the monocytes interface. By testing with monoclonal antibodies we found that a mean of 68, 95% (min. 58%; max. 82%) of these cells were living monocytes. We used the cell suspension to detect anti-monocyte antibodies in sera from 171 politransfused uremic patients with long incubation NIH cytotoxicity test.

A conversational program for hierarchic and non-hierarchic cluster analysis

The theoretical basis and the features of some cluster analysis programs are described in this paper. These programs use as input data an N x M matrix. For the N' less than or equal to N set of individuals, the cross-correlation matrix, R = (rij), is then calculated. The dissimilarity matrix, D = (dhk), and the distribution histogram of the distances between each pair is worked out. Hierarchic and non-hierarchic clustering techniques are allowed. Using the non-hierarchic strategy, the non-overlapping clusters are then separated into different groups. The distances between these groups are calculated and statistical tests of significance are performed. In the hierarchic case, a dendrogram is drawn using an agglomerative algorithm. As an example the programs (written in FORTRAN, batch or TSS version) were used to classify human mitotic chromosomes.